-------
          In order to overcome.pressure drop through the,
absorber configuration, a fan or blower is required for the
process gas stream.  Pressure drop varies widely with the type
of absorber equipment used.  The pressure drop through a packed
or spray tower is not significant compared with the pressure
drop encountered in a Venturi scrubber.  The energy requirements
for operation of a Venturi scrubber are relatively large.33

3.3.5     Environmental Impact of Absorption

          Adverse environmental effects resulting from the
operation  of an absorber include improper disposal of the
organic-laden liquid effluent-;- undesired emissions from  the
incineration of the regenerated waste gas, loss of absorbent  to
the atmosphere, and increased water usage.

          The liquid effluent from an absorber can frequently
be used elsewhere in the process.  When this is not possible,
the non-regenerated absorbent effluent should be treated to pro-
vide good water quality.  Such treatment may include  a physical
separation process (decanting or distilling) or -a chemical treat-
ing operation.

          Regeneration consists of heating- the liquid effluent
stream to reduce the solubility of the absorbed organics and
separate them from the absorbent.  These concentrated organics
can then be oxidized in an afterburner.  Emissions of S0x, NOX,
and other incomplete oxidation products may be a result,  depend-
ing on the nature of the regenerated gas stream.

          The control of one type of volatile :organic emission
can result in the emission of  another  at an even greater rate
                               82

-------
when  liquid  absorption  is  employed.   For  example, vapors  of
trichloroethylene  can be substantially reduced  in an  air  stream
by absorption  in a lean mineral oil;  however, at ambient  temper-
ature the  air  stream leaving  the  absorber might contain 120  ppin
mineral oil.3I*

           An add-on water  scrubbing  system will usually mean only
a minimal  increase in the  throughput  to the  existing  water  treat-
ment  facilities in a plant.

3.4        Condensation
           Condensation  is usually  applied in combination with  ^
 other .air  pollution-- control- systems „•   Condensers -located up-^  ;-
•stream  of  afterburners,  carbon beds,  or  absorbers  can reduce  ',"'
 the  total  load  entering the more expensive control equipment..-  ..
 When used  alone  as  in gasoline vapor  control in bulk  terminals,
 refrigeration is the usual  means of achieving the  low tempera-
 tures necessary  for condensation.  This  is the best application
 for  the principle of condensation.

 3.4.1      Equipment and Operating  Principles

           In a  two-component vapor (where one component can be
 considered non-condensible), condensation occurs when the partial
 pressure of the  condensible component equals the component's
 vapor pressure.  There  are  two ways to obtain condensation.
 First,  at  a given temperature, the system pressure may be
 increased  until  the partial pressure  of  the condensible compo-
 nent equals its  vapor pressure.  Alternately, at a fixed pressure,
 the  temperature  of  the  gaseous mixture may be reduced until the
 vapor pressure  of the condensible  component equals its partial
 pressure.  As the temperature  is further reduced,  condensation
                                83

-------
continues such that the partial pressure is always equal to the
vapor pressure.  While condensation by increasing pressure is
possible, in practice, condensation is achieved mainly through
removal of heat from the vapor.  Some components in multicom-
ponent condensation may dissolve in the condensate even though
their boiling points are below the exit temperature of the
condenser.

          Condensers employ several methods for cooling the
vapor.  In surface condensers, the coolant does not contact the
vapors or condensate; condensation occurs on  a wall separating
the coolant and the vapor.  In contact condensers, the coolant,
vapors.) and condensate are intimately mixed.

          Most surface condensers are common  shell-and-tube heat
exchangers.  The coolant usually flows through  the  tubes and  the
vapor condenses on the outside tube surface.  The condensed vapor
forms a film on the cool tube and drains away to  storage or
disposal.  Air-cooled condensers are usually  constructed with
extended  surface fins; the vapor condenses inside the  finned
tubes.
          Contact condensers usually cool the vapor .by spraying
an ambient temperature or slightly chilled liquid  directly into
the gas stream.  Contact condensers also act as scrubbers in
removing vapors which normally might not be condensed.  The
condensed vapor and water mixture is then usually  treated and
discarded as waste.  Equipment used for  contact condensation
includes simple spray towers, high velocity jets,  and barometric
condensers.
                               84

-------
           Contact  condensers  are,  in general,  less expensive,
 more flexible and  more efficient in removing organic vapors than
 surface condensers.   On the other hand,  surface condensers may
 recover marketable condensate and minimize waste disposal
 problems.   Often condensate from contact condensers cannot be
 reused and may require significant wastewater treatment prior
 to disposal.   Surface condensers must be equipped with more
 auxiliary equipment and have greater maintenance requirements.

 3.4.2     Applications

         Condensation processes with significant refrigeration
 requirements are being used for the recovery of gasoline vapors
 at bulk gasolin-e terminals.  In some installations, gasoline      ' •
 vapdrs are compressed and then refrigerated to obtain
 condensation.. . Other installations omit compression and simply-
"re'frigerate the vapors to temperatures approaching -73°C  (-10-00F) .
 Removal efficiencies depend on- the hydrocarbon concentration  o'f'
 the inlet vapors, but ar.e .greater  than .967*, for the removal  of
 saturated hydrocarbons.  Similar systems have been proposed
 for marine petroleum terminals.


           Condensers  have been used successfully (usually with -
 additional  control  equipment)  in controlling-organic  emissions
 from petroleum refining and petrochemical  manufacturing,  dry-
 cleaning,  degreasing,  and tar dipping.   Even when used as the
 primary control- equipment,  condensers  are  usually followed by
 a  secondary air pollution control  system (such as an  afterburner)
 which treats  the non-condensible gases and achieves  a  high degree
 of overall  efficiency.   Condensation is  sometimes practical in
 the surface coating  industry  when  large  concentrations of ..relatively
 nonflammable  materials  are  present.
                               85

-------
3.4.3     Condensation Costs

          The costs for she11-and-tube surface condensers depend
on the following:

          •*  the nature and concentrations of the vapors in
             the waste gas
             the mean temperature difference between gas
             and coolant
          ••  the nature of the coolant
          •*  the desired degree of condensate subcooling
          •*  the presence of non-condensible gases in the
             waste gas
          •*  the buildup of particulate matter on heat  exchange
             surfaces.

In general, capital costs for surface condensers are greater  than
the corresponding costs for contact  condensers.  Preliminary  cost
estimates can be made after the necessary heat exchange area  is
determined from  the factors listed above.  •      -    -.  • :~

          Costs "for .contact condensers;used ;for  organic emissions
control  also depend on 'the fa'c'tors given above.   In addition, the
cost  for treatment of  the organics-coolant  effluent must  be in-
cluded.

          Condensers have been most  widely applied  as prelimi-
nary  or  auxiliary equipment for other control devices  (e.g.,  as
part  of  the regeneration step in  carbon  absorbers).  One
important application as primary  control equipment  is  at
bulk  gasoline terminals as vapor  recovery units.  Annualized
and capital costs for refrigeration  vapor recovery  units  have
been  developed by the EPA in  a draft document  on the control of
                         ...  ,86

-------
   280.000
   240.000
CO
55
   200.000
   160.000
to
t-
<0
O
O
    .
t  120.000
0.
    80.000
    40.000
                   200
   400         600         300

  GAS FLOW  TO CONDENSER. 3CFM
                                                               1000
           Figure 3.4-1,
Capital Costs  for Refrigeration  Vapo
Recovery Units
                                   87

-------
hydrocarbons from tank truck  loading  terminals.35   These costs
are shown in Figures 3.4-1  and  3.4-2  as  a function of the
hydrocarbon vapor flow rate.  All  costs  are indexed to June 1976,
                                INLET VAPOR T£UftRATUBl= 80'F
                  too
                                   •00
                             FLOW, let*
         Figure 3.4-2.   Annualized costs for refrigeration
                       vapor recovery units.
           Capital cost estimates are intended to represent  the
 total  investment required to purchase and install a refrigera-
 tion unit.   New installations are assumed, but retrofitting at
 existing installations is expected to be only slightly  higher.
                               88

-------
            An example of annualized cost components for  a
 refrigeration vapor recovery unit is shown  in Table 3.4-1.

          TABLE  3.4-1,  COMPONENTS OF ANNUALIZED COSTS  FOR
               A REFRIGERATION VAPOR RECOVERY UNIT *6
 Gas Stream Characteristics
      Flow                                     420 scfm  (12 m3/min)
      Concentration                            20% (by vol.) hydrocarbons
      Inlet Temperature                         60'F  (16°C)
 Direct Operating  Costs
      Utilities                               $ 6,000*
      Maintenance                "                5,300
 Capital Charges                               30,000C
: Gasoline Recovery (Credit)                     (21,400)          -•..••.•-•>-• '
 Net Annualized Costs                           19,900e         . .-• •-•"•.....--

 aElectrlcity@* $.'04/kWh ($H.ll/GJ).
  Maintenance as 3% of the capital costs.
  Calculated @ 10% for 15 years plus 4%  for taxes, insurance, and administra-
  tion .
  Gasoline valued at $.40/gal ($.10/£) F.O.B.  terminal before tax.
 Q
  Computed as operating costs + capital  charges - gasoline  recovery credits
  Utilities costs will vary depending  on the inlet  concentration
  of the hydrocarbon vapors.   Gasoline credits help offset about
  35-75% of the annualized  expenses.   At higher flow rates, gaso-
  -line credits  appear to  offset1 operating expenses  and capital
  charges, resulting in a net savings  by recovering the vapors,

            In  general, condensation systems are uneconomical as
  the sole means of emission 'control unless the gas contains high
 -.concentrations of valuable organic vapors which can be recovered
  from the gas  stream.
                                   89

-------
3.4.4     Condensation Energy Requirements

          The amount and type of energy required for a condenser
will depend primarily on the type of condensation system employed.
The different configurations and their energy requirements vary
greatly from one system to another.  In general, condensation
systems consist of a cooling system and a means for transporting
the different streams.                      .   .

          A contact condenser requires energy in the form of
cold liquid supply, injection pumps, and a blower to move the
gas through the condensation zone.  The condensate and coolant
are usually not recovered due to the prohibitive costs;-but a
surface condenser can easily recover marketable condensate with-
out costly separation processes.  A surface condenser.requires
energy for a cooling water system or a forced convection air
cooler.                                          -

          Figure 3.4-3 is a plot of the energy requirements as
a function of vapor flow rate for a' refrigeration condenser sys-
tem used for the recovery of gasoline vapors*at a bulk terminal.37
Characteristics and bases for this system -are  found in -Table
3.4-1.  Electricity is used to  power tb.erefri.ger at ion unit
which provides the cooling in this example.  A refrigerator
can be used alone or in conjunction with a  compressor to
facilitate condensation.  The type of  equipment chosen for a
refrigeration unit depends on the  concentration of organic
vapors in the gas stream, the physical properties of the vapors,
and the flow rate of the gas stream.

          If the organic vapors are recovered,  some energy
credit  can partially offset the energy required to effect the
condensation,  This is especially true if  the  condensate can
be used as fuel or if the energy required  to produce the organic
compound is very high.
                              90

-------
    1.2
 CO

• a
 o
 o  v.o
 u
 oc
 5
 o
 UI
 tr
 o
 K
 UI
 z
 UI
 3
 Z
 Z
    0.8
    o.a
    0.4
    0.2
                     400              3OQ             1200

                            GAS  FLOW TO  CONDENSER.  SCFM
                                              1600"
         Figure  3.4-3,
Energy Required for a  Refrigeration  Condense:
(Gasoline Vapor Recovery System at a Bulk
Terminal)
                                    91

-------
          Condensation is rarely used as the sole means for con-
trolling organic vapors.  The total energy requirement for a sys-
tem involving condensation must allow for the energy associated
with a secondary air pollution control system, such as an after-
burner .

3.4.5     Environmental Impact of Condensers

          A condenser will create few secondary environmental
problems when the condensation process is considered by itself.
Problems that do arise include disposal of non-condensibles in
surface condensers and refrigeration systems, and the need for
proper treatment of the liquid effluent in contact condenser
systems.  Condensation is rarely used alone as a control method;
therefore, it is imperative that all associated equipment produce
effluent streams of sound environmental quality.

          The non-condensible gas effluent from surface con-
densers is either vented to the atmosphere or further processed
te.g., via incineration), depending on the effluent composition.
The coolant never contacts the vapors or condensate in a surface
condenser; therefore, the recovered organic compounds are usually
reusable.  The condensate might not be saved  if more than one
compound is condensed and separation is- costly.  Proper.treatment
of the condensate is then imperative before final disposal.  This
also applies for the recovery of volatile organic emissions by
refrigeration.

          In contact condensation, the condensate is contaminated
with the coolant liquid.  The usual procedure is treatment of
the waste stream and disposal.  The amount of organic material
entrained in the existing wastewater will depend on the extent  of
treatment..
                               92

-------
3.5       Flaring

          Flares are most commonly used as safety devices to
incinerate waste gases from petroleum refining and petrochemi-
cal manufacturing operations.  Flares are preferred when dispos-
ing of gas streams with sufficient heat value to attain the
combustion temperature without the use of supplemental fuel.
Flares are also preferred when disposing of gases with little
recovery value, or for gases containing contaminants that make
recovery unprofitable.

3.5.1     Equipment and Operating Principles

3.5.1.1   Operating Characteristics                       .    .--''   -

          Complete combustion of organic gases and vapors can b.e   .
achieved if 1) the gas 'has sufficient heat value to attain the""
minimum temperature necessary for combustion, 2) adequate com-
bustion air is supplied, and 3) the gas and air are adequately
mixed.  An insufficient air supply produces a smokey flame.  With-
in the reducing atmosphere of the smoke, hydrocarbons can crack
to elemental hydrogen and carbon or can react to form polymers.
Side reactions- become more pronounced -as the molecular weight
and unsaturation of the -inlet gas increase.  Olefins, diolefins,
and aromatics characteristically burn with smokey, sooty flames
as compared ;with..paraf fins and naphthenes.  A smokeless flame  can
be obtained"Vhen 'an adequate amount of combustion air is mixed
with the gas so that it combusts completely and rapidly before
any side reactions can occur.

          Combustion of organics in a well-operated  flare may be
nearly complete.  In typical installations hydrocarbon removal
efficiencies of 99% have been  obtained.  Not  all of  the hydro-
carbons are completely oxidised  to carbon  dioxide and water..
As much as  10% of the combustion products may be carbon rr.cr.oxice. :e
                               93

-------
          Firing of the flare can produce temperatures which
favor the formation of nitrogen oxides.  Other air contaminants
emitted from flares vary with the composition of gases burned.
Sulfur dioxide is produced from the combustion of sulfur com-
pounds such as hydrogen sulfide.  Burning hydrogen sulfide can
create enough sulfur dioxide to cause crop damage or local
nuisance in some instances.  However, for emergency conditions,
discharge of a stream containing hydrogen sulfide to an elevated
flare may be safer than venting or incineration at a low elevation,
          Materials that cause health hazards or nuisances should
not be combusted in flares.  Compounds such as-mercaptans or
chlorinated hydrocarbons require special combustion devices with
chemical treatment of the gas or the combustion products.

3.5.1.2   Types of Flares

          There are, in general, three types of flares for the
disposal of waste gases:  elevated flares, ground-level flares,
and burning pits.

          Burning pits are reserved for extremely large gas flows
caused by catastrophic emergencies in which the capacity of the
primary smokeless flares is exceeded.  Ordinarily, the main gas
header to the flare system has a water seal bypass to a burning
pit.  Excessive pressure in the header blows the water seal and
vents the vapors and gases to the burning pit for combustion.

          Smokeless combustion can be obtained in an elevated
flare by the injection of an inert gas into the combustion zone
to provide turbulence and inject air.  The most commonly used
air-injecting material for an elevated flare is steam.  Three
main types of steam-injected elevated flares are in use.  These

-------
 types  vary  in  the manner  in which  the  steam  is  injected  into the
 combustion  area.

           In the  first type, steam is  injected  by several small
 jets placed concentrically around  the  flare  tip.  The jets  are
 installed at an angle and cause  the  steam  to discharge in a
 converging  pattern  immediately above the flare  tip.

          A second  type has a flare  tip with no obstruction to
 flow.   The  flare  tip is the same diameter  as the stack.  The
 steam  is  injected by a single nozzle located concentrically
 within the  burner tip.  In this  type of flare,  the  steam is
 premised  with  the gas before ignition  and  discharge.

          A third type is equipped with a  flare tip that pro-
"motes  turbulence  by causing the  gases  to flow through several
 tangential  openings.  A steam ring at  the  top of the stack  has  -
 numerous  equally .spaced holes for  injecting  steam into the
 gas  stream.

           Most modern refinery and petrochemical-plant flares
 have a'tip  with  three locations  for  steam  injection.  The steam
 rates  to  the three  different locations at  the flare tip  are con-
 trolled by three  different regulator valves.

           Steam  injection provides the following benefits:

           1.   energy  available at  relatively low cost
               can be  used to inject  air and  provide
               turbulence  within  the  flame

           2.   steam and/or water react with  the gas to  form
               oxygenated  compounds that bum readily at
               relatively  low temperatures
                               95

-------
          3.  steam retards polymerization by reducing the
              partial pressure of the fuel.

          The injection of steam into a flare can be controlled
either manually or automatically.  In some installations, the
steam is supplied at maximum rates,  and manual throttling of
the steam is required for a particular gas flow rate.  For the
best combustion with minimum steam consumption, instrumentation
should be provided which automatically controls the steam rate
based on the gas flow rate.

    Ground-level flares are usually enclosed and are used
primarily where noise or light would be objectionable.  A
ground-level flare is usually designed for daily process needs
with the high flows during major emergencies routed to an
accompanying elevated flare.  Ground-level flares are of four
principal types:  horizontal venturi, water inj.ection, multi-
jet, and vertical venturi.

          A horizontal venturi flare system utilizes groups of
standard venturi burners.  In this type of burner, the gas pres-
sure inspires combustion air for smokeless operation..

          A water-injection flare consists of a single burner
with a water spray ring around ,the, burner nozzle.  Air is drawn
in as a result of the spray action and -the water vapor provides
for the smokeless combustion of gases.  Water is not as effective
as steam for controlling smoke with high gas-flow rates, unsatu-
rated materials, or wet gases.

          A multijet ground flare uses two sets of burners, one
for normal gas release rates and both for higher flaring rates.

          A vertical, venturi ground flare also uses commercial-
type venturi burners.  This type of flare is suitable for rela-
tively small flows of gas at a constant rate.

                               96

-------
3.5.2     Applications and

          Flares are usually unsuitable for the treatment of
dilute gas streams because the costs of supplemental fuel needed
to attain the minimum combustion temperature are prohibitive.
Unlike afterburners, flares have no heat recovery capability
that could produce credits for heat generated from combustion.
Flares are also generally less effective than other devices in
controlling organic vapors.  While nearly all of the hydrocarbon
pollutants are combusted, considerable quantities of carbon mon-
oxide may be produced.

          Elevated flare equipment costs vary considerably
because of the disporportionate costs for auxiliary and control
equipment and the relatively low costs of the flare stack and
burner.  As a result, equipment costs are rarely dependent on
the gas flow rate.  Typical installed.costs range from $30,000
to about $100,000.  Figure 3.5-1 represents estimates of installed
cost for a typical elevated flare in the petrochemical industry.35
Low level flares are approximately ten times more expensive for
similar capacity ranges.1*0

          Operating costs are determined chiefly by fuel costs
and by steam required for smokeless flaring.  On the basis of
40 cents per 10 million Btu's of fuel, typical refinery elevated
flare stack operating costs (2-foot diameter stack) are about
$2000 per year.*1  The cost of operating large elevated flares
can be considerably greater than this number.

          Figures 3.5-2 and 3.5-3 represent estimates of capital
and annualized costs for an enclosed ground-level flare handling
small volumes of gasoline vapors from tank truck loading opera-
tions at gasoline bulk terminals.1*2  Capital costs for enclosed
                                97

-------
     1000
co


O
X
-------
   nao.ooo -
   240,000
2

<  200,000
a
03
t-
«
o
   180,000
Z  120.000
    80,000
    *OvOOO
                              J_
                   200        400        600         800

                          QAS  FLOW TO  FL.ABE, SCFM
                                 1QOO
           Fig-are 3.5-2 .
Capital  Costs for  an Enclosed  Ground-level
Flare  (Vapors from Tank Truck  Loading
Operations at a Bulk Terminal)
       99
-------
  60,0001-
w

*  50,000
^  40.000

H
m
O
c
a
ut
N
z
   30.000
   20.000
   10.000
/
                      200,000  PPM

                    GASOLINE  VAPOR
                 200
  400        600        BOO


 QAS  PLOW TO  FLARE. SCFM
              1000
         Figure 3.5-3
Annualized Costs for an  Enclosed Ground-

level Flare (Vapors from Tank Truck Loading

Operations at a Bulk Terminal)

        100
-------
flares are greater than elevated flares for comparable  flow
rates; however, enclosed flares afford better emission  control
and greater safety for the application mentioned,

          Annualized costs are minimized in this example since
hydrocarbon concentrations are sufficient to support combustion
without supplemental fuel.  A pilot is required to ensure igni-
tion.  Maintenance costs average about two percent of capital
costs.  Power costs are associated with a blower that supplies
combustion air to the burners and a purging system that prevents
the flare from starting when explosive mixtures are present.

3.5.3     Energy Requirement for Flares
          'Sniok'ete'ss operation,""of- a. flare usually requires  a.
supply of steam or air Because'very ffew organic compounds  bum  ...
smokelessly without steam' or air injection.  The purpose of
energy input to a flare' is to•maintain efficient operation,  since
flares usually do not need any additional fuel to  support  the
combustion of the waste stream."  Other possible energy  requirements
may be power for -a vapor--purging- sys'tem -which prevents  explosive
mixtures in flare stacks ..and fuel for a gas pilot.  Additional
fuel will be required if dilute gas streams are to be flared;
however, gas streams with low heating value are better  suited
to disposal by direct incineration.1*3

          A forced draft flare is used for special purposes, and
its energy requirement includes electricity for a blower to
provide the flare tip with combustion air.  A ground level flare  •-•••
normally uses a natural draft air supply, and steam is  seldom
necessary for smokeless operation.1*4                       ., ..,.
                                              \
          Figure 3,5-4 displays the energy requirement  for a
low capacity, enclosed, ground-level flare.  Included in che
                              101
-------
   2.0-
    1.8 -
    1.6
   1.4
 D

 CD



°o 1.2
 z
 111
o
a
IU
a



g
IU
•JS.
ttl
    1.0
    0.8
   0.4
   0.2
             2OO      400      600      800

                   QAS  FUOW TO  FLARE.  8CFM
                                               1000
       Figure 3.5-4.   Energy Requirements for  a Low Capacity,
                        Enclosed, Ground-level Flare

                          '••'". 10Z'.
-------
energy consumption for this example is a combustion air blower
and a, vapor purging system.1*5

          Since flares are used for emergency operation and as
safety devices, it is difficult to predict energy requirements
for one single flare, especially one with a large capacity.
Smooth and efficient operation of the process is the best
guarantee of minimizing energy consumption of a flare  system.

3.5,4     Environmental Impact of Flaring

          The operation of a flare affects the environment in
the following areas:   chemical and oxidation emissions, particu-
lat-e emissions,, thermal and visible radiation, and noise.
Elevated flares are primarily intended for plant emergencies
and are inherently not as efficient in the above areas as new,  •••••••-
enclosed, ground-level flares.

          Chemical emissions are the direct result of incomplete
combustion of the volatile organics contained in the waste gas
stream.  Carbon monoxide and partially oxidized hydrocarbons such
as aldehydes are known to be products of elevated flares.   Because
of lower design velocities, emission o'f unburned hydrocarbons is
much lower in an enclosed, ground-level flare.1*6

          Sulfur compounds, nitrogen compounds,  and other unde-
sirable chemicals are also completely oxidized and  emitted to  the
atmosphere.   In particular, hydrogen sulfide streams are often
routed to flares and burned.  S0x emissions from refinery flares
average 27 lb/103 bbl refinery feed (77 kg/103m3).*7

          N0x emissions from flares are also common due to
direct contact of nitrogen with oxygen at the flame temperature.
                               103
-------
But NOX emissions from elevated flares using steam to inject
air are lower than for gas-fired burners due to the lower flame
temperature.  A typical emission rate for a flare system in a
petroleum refinery is.19 Ib NOX/103 bbl refinery feed (54 kg NOX/
103m3 refinery feed)."*

          Air must be well mixed with the gas at the point of
combustion in a flare or soot will escape from the flare.  A
smokeless flame is attained when an adequate amount of air is
kept well mixed at the point of combustion.  This is usually
accomplished by injecting steam to provide the needed turbu-
lence.

          Other undesirable emissions include'thermal and
visible radiation.  Steam injection can reduce thermal radiation
by lowering the flame temperature'.'  -Luminosity cannot be com-
pletely reduced, but enclosing a.-ground level flare is desir-
able, especially in populated areas.

          Low frequency combustion noise and high frequency jet
noise -in flares is. sgi environmental problem for elevated flares
in populated are iff",  The jet noise is not a problem with ground-
level flare-s, and th« combustion noise is reduced significantly.1*9

3.6    ••-• Other Control Methods

          In many instances, the emission of chemically reactive
organic vapors may be completely avoided.  Compounds of low
photochemical reactivity can sometimes be substituted for highly-
reactive compounds currently in use.  While the total organic
enissions would not decrease and could increase, the substitu-
tion of nonreactive or less reactive organic compounds could
reduce urban photochemical oxidant formation.  Pew volatile
organic compounds are of such low photochemical reactivity that
they can be ignored in oxidant control programs.
-------
          The most efficient technique for controlling organic
emissions is to design processes which produce  little or no
pollution.  Improved operating and maintenance  procedures  can
sometimes substantially reduce or eliminate organic emissions.
New process technologies can reduce organic emissions by
avoiding inefficient or poorly controlled operations.

3-6.1     Substitution ofLess.Photochemically  Reactive Materials

          Most air pollution control  strategies applicable to
stationary  sources of volatile organic compounds (VOC) are pat-
terned  after Rule 66 of the Los Angeles  County  Air Pollution -Con-
trol District  (presently Regulation 442  of the  Southern California
•Air"-Pollution Control District).  Rule 66 and similar regulations
incorporate.--two- basic -strategies  to..reduce ambient oxidarit" concen-
trations :   selective substitution Gf  less photochemically  reactive
materials,  and positive reduction schemes for the destruction or-
recovery of-organic vapors.              '•          '        "•  •'

          Of the small number  of  VOC  which have only negligible
photochemical reactivity,  several are suspected of posing  threats
to human health.  Only those compounds listed in Table 3.6-1 have
b-een recommende-d for exclusion from oxidant  control under  State
Implementation Plan regulations.  Methylene  chloride, benzene,
benzaldehyde, acetonitrile,  chloroform,  carbon  tetrachloride,
ethylene  dichloride, and ethylene dibromide  are also  only
slightly photochemically reactive.  However,  all except benzal-
dehyde  are  possible  carcinogens, teratogens, or mutagens. -.-
Benzaldehyde  forms a strong  eye  irritant when irradiated.   It
is not  appropriate to  encourage  or  support  increased  utilization
of these  compounds.
                                105
-------
      TABLE  3.6-1.  NOHTQXIC VOLATILE  ORGANIC COMPOUNDS
             OF NEGLIGIBLE PHOTOCHEMICAL REACTIVITY50
                  Methane
                  Ethane
                  1-1-1 Trichloroethane (Methyl Chloroform)
                 -Triehloro-trifluoroethane (Freon 113)
          The volatile organic compounds listed in Table  3.6-2
yield significant'"oxidant only during multiday stagnations.
Perchloroethylene, the principal solvent employed in the  dry
cleaning industry is also of low reactivity.  It was not  included
in Table 3.6-2vtoeeattse of .its ^suspected adverse health effects.
TABLE J. 6-j
      .' ':**#
          Methyl  Benzoate
                      VOLATILE oiGAHic COMPOTMDS OF LOW
                       ^ CHEMICAL REACTIVITY81
                            Tertiary Alkyl Alcohols
                            Methyl Acetate
                            Phemyl -Acetate  •...••-- •- •
                            Ethyl Amfnes    '••-    •'
                            Acetylene
                                         Formamide
          Most volatile  organic  compounds  are significantly
more reactive than  the VOC listed in Table 3.6-2.
 3.6.2
  Pro cess Operation and Material  Changes
           Process  operation and material changes are the most
diverse options  available for control of organic emissions.  In
general,  there are three types of possible changes:  1) material
                                106
-------
substitutions, in which alternate materials are used in the pro-
cess or products of the process are reformulated; 2) process
changes, in which certain operations of the process are modified,
and 3) housekeeping and maintenance procedure changes.   Each
type of change is best illustrated by examples.

          Material substitutions are intended to reduce volatile
organic emissions by replacing materials used in the process with
less volatile or nonreactive compounds.  For example, organic
emissions from surface coating operations can be significantly
reduced by replacing conventional organic solvent-borne coatings
with water-borne, high solids, or powder coatings.   Water-borne
coatings can be applied with most of the same methods used for
organic solvent-borne coatings.  Water-borne spray coating spL-r-;•••
vent'contains 20 to 30% organic solvent; thus, volatile organic
emissions cannot be completely eliminated.

          Process changes reduce organic vapor emissions by using
raw materials more effectively.  For example, organic emissions
from surface coating can be reduced by adopting more efficient
coating application methods or by changing curing techniques.
Electrostatic spray coating, electron beam curing,  and ultra-
violet curing reduce emissions by limiting solvent  contact with
air.  Most uses of electron beam and ultraviolet curing are
still in the developmental stage.52

          Improved maintenance procedures and "good housekeeping"
reduce volatile organic emissions by preventing leaks and
spillage and by improving produce yield.  For example, emissions
from process heaters and steam boilers can be minimised by main-
taining the fuel-to-air ratio at the optimum level.  Vapor leaks
from pumps and valves can be reduced by increasing routine
maintenance and inspections.  Conscientious preventive
                               107
-------
  maintenance can minimize fugitive  emissions from process and
  auxi1i ary e quipment.

  3,7       References

  1.   Danielson* J. A.  (ed.).  Air Pollution Engineering Manual,
      2nd Ed.  uV S. Environmental Protection Agency.  Research
      Triangle Park, N.C.  AF-4Q.  May 1973.  487 p.   ,_  ,	

  2.   CE Air Preheater-._ Report  of Fuel Requirements, Capital
      Cost and Operating Expense for Catalytic and Thermal
      After-Bai|nifi-t --B. S.  Environmental Protection Agency.
      R^searcft^TtJ.ll^li^Park,  N.C,  EPA-450/3-76-031.  1976.
      241 p.'r/      '   '      ";  '._    ...;vv
              .,..<-  !t*~ t.-~       ,-••''.'      "''  """. "•         "
  3.   ParsoxMt.Jtf^LjSMKKBal Oxidation System Actually Sa-^es Energy
      fox Coal C6flle<£'. f Sprint-ed from Pollution Engineering, May
      1977.        . -   ~

  4.   .Capital &&jj^t9tio.g  Costs'of Selected Air Pollution
                                 J-76-014.  GAU>; inc:, Eifcs,
  5.   .fbefe-renee 2. ..,,         .,--           "               "

  6.   Control of Walmtile  Organic"Emissions from Existing  Stationary
      Sources, Volume  It   Control Methods ft>r Surface-Coat ing Oper-
      ations.  U. S. Environmental Protection Agency.  Research
      Triangle Parlcl N.C*-  IPA-450/2-76-028.  November 1976.
      pp. 17-79, 88"-?4, 08-127.

7-9.   Reference 2<
                                 108
              f>i
-------
   10.   Compilation of Air Pollution Emission Factors, 2nd Ed.
        U.  S.  Environmental Protection Agency,  Research Triangle
        Park,  N.C.  February 1976.

   11.   Reference 6.

   12.   Reference 10.

   13.   Reference 6.

   14.   MSA Research Corporation.  Package Sorption Device System
        Study.  Evans City, .Pennsylvania.  EPA-R2-73-202.  April
        1973.  . Chapters .4 an-d* 6.

  "15.   MSA-Research Corporation.  Hydrocarbon Pollutant Systems
        Study.'Volum* 2,  -P&-219 074.-  1973;  Appendix C.

   16.   Reference 6.

   17.   Reference 15.

18-19.   Reference 15.

   20.   Reference 6.   	  	

21-24   Reference 15.        "

25-27   Treybal, R. E. Mass-Transfer Operations.  New York.
        McGraw-Hill Book Co,  1968.  pp.  129, 154, 225-226.

28-29   Reference 1.
                               109
-------
   30.   Scrubber Handbook, Volume I.  EPA Contract No. CPA-70-95;
        Ambient Purification Technology, Inc.  Riverside, Califor-
        nia.   July 1972.

31-32.   Air Pollution Control Technology and Costs:  Seven
        Selected Emission Sources.  U. S. Environmental Pro-
        tection Agency.   Research Triangle Park, N. C.  EPA-450/3--
        74-060.  December 1974.  pp. 183-193.

   33.   Reference 1.

   34.   Surprenant, K. S. and D.'W. Richards of Dow Chemical Com-
        pany.  "Study to Support New Source Performance Standards
        for Solvent Metal Cleaning Operations," 2 vol., prepared
        for Emission Standards and Engineering Division  (ESED),
        under Contract No. 68-02-1329, Task Order No. 9, June  30,
        1976.  As cited in Draft Document Control of Volatile
        Organic Emissions from Solvent Metal Cleaning.  U. S.
        Environmental Protection Agency.  November 1977.

35-37.   Environmental Protection Agency.  Control of Hydrocarbons
        from Tank Truck Gasoline Loading Terminals, Draft Copy,
        OAQPS, Research Triangle Park, N..C.  May 1977.

   38.   Reference 1.

   39.   Booz, Allen,  and Hamilton,  Inc., Foster D. Snell Division,
        Cost of Hydrocarbon Emissions Control to the U.  S. Chemi-
        cal Industry  (SIC 28), final report, Volume 1.  Florham
        Park, N. J.  December 1977.

40-41.   Environmental Protection Agency.  Flare Systems  Study.
        Office of Research and Development.  Research Triangle
        Park, N. C.  EPA-600/2-76-079.  March 1976.

                               110
-------
   42.  Reference 35.

43-44.  Reference 40.

   45.  Reference 35.

   46.  Reference 40.

47-48.  Reference 10.

   49.  Reference 40.

50-51.  Environmental Protection Agency.   Recommended Policy
        on Control of Volatile Organic  Emissions-   Federal
        Register 42_(131) :35314-35316.   July  8 ,  1977.

   52,  Reference 6.
                               Ill
-------
4.0       CONTROL SYSTEMS FOR INDUSTRIAL PROCESSES

          This section describes volatile organic emissions and
control technology for 18 industrial operations.  Processing
methods and equipment are described in enough detail to indicate
how emissions are produced.  Emission quantities and compositions
are described.  Currently applied control technology and other
applicable control methods are discussed.  The efficiency of
current and potential control methods is addressed.  General dis-
cussions of energy requirements, costs, and environmental impacts
of control methods are covered in Section 3.0.  Information for
specific processes, when available, is presented in this section.

          The 18 operations described in this section are not
the only sources of volatile organic emissions.  They are the
sources for which information is available.  Some are described
more completely than others.  The extent of coverage depends on
the availability of information for each operation.

          The first section, 4.1, describes emission sources
common to the petroleum and chemical processing industries.  The
following 18 sections, 4.2. through 4.19, are separate discussions
of each class of industrial operations.  References are given at
the end of each section.
                               112
-------
 4.1       Emission Sources Commonto Jthe Petroleum and  Chemical
           Proceas  Indus trie s

           Petroleum and Chemical Process Industries  (PCPI)  in-
 clude oil and  gas  production, gas  processing, oil refining,  and
 organic chemicals  processing.  There are several sources of vola-
 tile organic emissions found in all areas of the PCPI.   Typical
 examples are listed in Table 4.1-1.   Most emissions  are the re-
 sult of accidents,  poor planning,  inadequate maintenance, or
 simply normal  leakages.

              TABtE 4.1-1.  EMISSION SOURCES COMMON TO THE
                PETROLEUM AND CHEMICAL PBDCESS INDUSTRIES
 'Storage Tanks   "  ,    •  .--.    ••.. •    pmap and  Compressor Seals
 •Wa&tewater Treatment '   '•..—    •• -"    treasure  Belief. Devices
 Gaoling Towers   •  • "           -       Drains, Sumps, Hot Wells
 Compressor Engines                 .    Blind Changing
 Stationary Fuel Combustion             Saaplliig
 Valves                               Uncontrolled Blowdowti
 Flanges and'Other Connecting Devices
  Discussed in Section 4.5

  Discussed in Section 4.15.
           'Refineries and Organic ChemicalPlants

           Volatile organic emission rates vary  greatly among
refineries and chemical plants.   These variations  are caused by
differences  in feedstocks, products, processing  complexity, and
applications of control measures.  In general, any hydrocarbon
found in  a process stream can be emitted from one  or more of the
common sources.  The two largest sources are storage and fugitive
leaks.
                                 113
-------
           Oil and Gas Production/Gas Processing

           Emissions from oil and gas production usually contain
saturated, lower molecular weight hydrocarbons.  Fugitive losses
account: for most of the hydrocarbon emissions.  One study esti-
mated that 897o of the hydrocarbon emissions at an oil production
facility were due to leaks.1  Gas losses of 0.2270 of the gas pro-
duced are attributed to wellsite leaks.2  Natural gas production
has an especially high fugitive emission potential because of
high pressures, the corrosiveness of hydrogen sulfide and water,
and the gaseous nature of the products.  Since most installations
are in remote locations maintenance is sometimes infrequent.  Na-
tural gas processing plants are essentially miniature refineries,
but they have a lower fugitive emission potential because they
employ simpler process schemes and lower processing temperatures.

           Two other common sources that have slightly more sig-
nificance for oil and gas production than for oil or chemical
processing are internal combustion engines and flares.  Natural
gas production requires numerous compression steps.  Many of the
field compressors use internal combustion engines.  Also, uncon-
trolled blowdown and flaring of"gases is practiced more in oil
production than in the other operations.  Excess gas produced
with the oil is often unneeded onsite and uneconomical to trans-
port.  It is usually disposed of by venting or flaring.

           Each of the thirteen emission sources  listed  in  Table
4.1-1 is  described separately in the  following Sections  4.1.1
through 4.1.13.  Emission characteristics;  control  technology;
and cost, energy, and environmental  impacts of controls  are de-
scribed.  References are given in  Section  4.1.14.
                              ...114
-------
 4.1.1      Storage Tanks

            Various types of tanks are used for the storage of pro-
 ducts and feedstocks in every area of the PCPI.   Emissions from
 storage tanks are discussed in Section 4.5.

 4,1.2      Was tewater Treatmertt

            Wastewater treatment facilities exist in all phases of
 oil,, gas, and chemical production and processing.  They are dis-
 cussed in Section 4.15,

 4,1,3      Cooling Towers

            Petroleum refineries-, chemical plants, and gas process-
. ing plants use large quantities of water for cooling.  Before the
 water can be reused, the heat (abosrbed in heat exchangers) must '
 be removed.  This is- usually accomplished by allowing the water to
 cascade through a cooling tower,, where it is contacted counter-
 currently with a stream of air.  Evaporation removes sensible heat
 from the water, and warm, wet air leaves the top of the tower.  The
 cooled water-collects in an open basin at the bottom, from which
 it is recirculated through the process water system.

 4.1.3.1    Emls s _i on Char act er i s t i c s

            During processing, volatile organics may leak into the
 coaling water system.  These organics may then be stripped by air
 in the cooling tower and emitted 'at the top of the tower and from
 the basin.  Emissions can include any organic processed within
                                115
-------
the plant.  Hydrocarbon emissions from cooling towers in petro-
leum refineries have been estimated to be 700 mg/m3 of cooling
water (6 lb/10€ gal water).   It is emphasized that these emis-
sions vary widely.

4.1.3.2    Control Technology

           Cooling tower emissions can be best controlled at the
point where they enter the cooling water, at the leaking heat ex-
changers.  Hence, systems for detection of contamination in wa-
ter, proper exchanger maintenance, speedy repair of leaks, and
good housekeeping programs, in general, are necessary to minimize
the emissions occurring at the cooling tower.

4.1.3.3    Cost. Energy, and Environmental Impacts of Controls

           Maintenance and good housekeeping are already performed
in many plants.  Costs are the cost of labor for inspection and
the cost of materials for repairs or maintenance.  Credits are
received for product recovery and improved process operations.
Increased plant safety is an additional benefit.

           Minimal energy is expended for inspection or maintenance,
An indirect energy credit is received in the form of recovered or-
ganic products.  The net result is a positive energy impact.

           Costs for monitoring equipment to detect organic con-
tamination in water range between $3500 and $10,000.''  Energy re-
quirements should be minimal.

           No secondary environmental impact will be produced by
the above control methods.
                               116
-------
4.1,4      Compressor Engines

           Many older refineries,  organic  chemical plants,  gas
processing plants, and  gas producing  fields  use  internal combus-
tion engines  fired with natural  gas or  low molecular weight re-
finery gas to run high-pressure  compressors.   The largest numbers
are found in  gas production/processing  operations.

           Internal  combustion engines  are less  reliable and harder
to maintain than those  driven by steam  or  electricity.5   Future
use of internal combustion engines will probably decline because
of problems with the cost and availability of  natural gas as well
as environmental regulations.

. 4...1...4.1    -Emission  Characteristics

            Internal  combustion engines  have inherently high vola-
 tile organic  emissions.  Volatile' organic emissions from internal
 combustion  engines  fired with refinery  fuel gas 'are approximately
 220 mg/m3  fuel  (1.4  lbs/10J  scf fuel).6  Further discussion is
 found  in Section.4.13  on combustion sources.  ,                 f

 4.1.4.2     Contro1n Techno1o gy

            The  major means of controlling emissions from this
 source is carburetion adjustments similar to those applied  to
 automobile engines  for emission control.  Further discussion of
 combustion source  controls is given in Section  4.13.

 4.1.4.3    Cost, Energy and  Environmental  Impact o_f^J3ontrcl.^ ..-•"""'•""

           Proper carturetion adjustment will  maximise fuel com-
 bustion  efficiency.  Maintenance costs  may be  more than compensated
 by savings  in fuel consumption.   Further discussion of energy, costs
                                117
-------
and environmental impact for combustion source controls is pro-
vided in Section 4,13.

4.1.5      Stationary Fuel Combustion

           Heat is produced for use in many phases of the PCPI by
combustion of fuel.  Process heaters and steam boilers can be found
in chemical plants, gas processing plants, and refineries.  They
are discussed in Section 4.2 (Petroleum Refineries).  Heater-
treaters are used to aid in oil-water separations in field produc-
tion operations and are described in Section 4.3.

4.1,6      P ipeline Valves

           Large numbers of pipeline valves are associated with
every type of equipment used in the PCPI.  Although many types
exist, they perform one of three functions:

        •*  On/off flow control and throttling,
        «*  flowrate control (control valves), or
        .•"  flow direction control  (check valves).

Almost all check valves are -enclosed within the process piping,
but their top access connections to working parts may be sources
of fugitive emissions.  All other valv.es consist of internal parts
connected to an external actuator by means of a stem,  A packing
is used to prevent process fluid from escaping from the valve.
On/off and throttling valves are actuated by the operation of
a handwheel or crank.  Control valves are automatically operated,
often by air pressure.
                              ..-,113
-------
4.1.6.1    Emission Characteristics

           Under the influence of heat, pressure, vibration, fric-
tion, and corrosion, leaks can develop in the packing surrounding
the stem.  Liquid leaks drop to the ground or nearest surface and.
vaporize at a rate dependent upon volatility and ambient condi-
tions.  The average leak rate from valves is 0.07 kg/day-valve
(0.15 Ib/day-valve).  The factor expressed in terms of refinery
throughput is 0.08 kg/103 liters refinery feed (28 lb/103 bbl re-
finery feed).7 The valves tested had very diverse rates of leahage.

4.1.6.2    Control Technology

           Emissions originating from product leaks at valves ca-n
be controlled only by regular inspection and prompt maintenance
of valve packing boxes.  Because of its dependence -on the nature
of-the products handled, the degree of maintenance, and the charac-
teristics of the equipment, the level of emission reduction achiev-
able by such programs is difficult to estimate.

4.1.6.3    Cost, Energy, and Environmental Impact of Controls

           Inspection and maintenance of valve packing boxes are
routinely performed by many industries.  A discussion of mainte-
nance and good housekeeping is provided in Section 4.1.3.3.

          • No secondary environmental impact will be produced by  "
these control methods.

4.1.7      Flanges and Other Connecting Devices

           Process piping can be joined to process vessels  and
equipment or to other lengths of piping in as many as  17 differ-
ent ways.8  There are, however, three principal  types  c£ joints
                               119
-------
found in petroleum and chemical operations:

        •"  threaded fittings,
        *  flanges,  and
        *  welds.

           Threaded fittings are connecting devices into which
threaded lengths of pipe are screwed.  They are most commonly
used for pipes of 5 cm (2 inch) diameter or smaller.  Threaded
joints are more common in field production operations than in
processing plants.

           Flanges are removable connections consisting of cir-
cular discs (faces)  attached to the outer circumference of pipe
ends.  A gasket forms the seal between the pipe ends and is held
in place by bolts connecting the two flange faces.  Flanges are
the most common connecting devices used in refineries and chemi-
cal plants.

           Welds are employed to connect pieces of pipe when dis-
assembly will not .be needed.  Welding produces a  seal almost as
strong as the pipe itself and is desirable wherever practical.

4.1.7.1    Emission Characteristics

           The influences of hesct, pressure, vibration, friction,
and corrosion can cause leakage in connectors.  Of  the three kinds
of connectors described, threaded fittings that have been fre-
quently assembled and disassembled are most prone to leaks.  Welds
are virtually leakproof because they are rigid connections less
susceptible to the effects of vibration, etc. , that disturb the
original seal.  Flanges can  leak if  the gasket material is damaged
or the flange is not aligned properly or because  of seal deforma-
tion due to thermal stresses on the  piping system.  However, in a
         c
                                120
-------
 study of oil refineries in California, flanges were found  to  be  a
 negligible source of emissions.

 4.1.7.2    Control Technology

            Emissions from product leaks at flanges and  threaded
 fittings can be controlled by regular inspection and prompt main-
 tenance,.

 4,1.7.3    Cost, Energy, and_ Environmental Impact of Controls

            Inspection and maintenance., of flanges and threaded-'.;:'.""'
 fittings are-routinely-^performed by many industries.  A discus-
. slott-.'of main-tenance and- -good, housekeeping is provided in Section
 4,1:3.3. ".'.':  ~""\:   ^'"".".''•••••'• '"'""""   .".'"'".'' "•  '  .V  ..  •    •   ".'.-•'•.'••  "'*'

• -•-         'No .secondary-.ehvifonmencal impacts will.be produeed-by
 these controls.     .-''••'         -     •     ":'      • ""      "

 4.1.8      Pump and CompressorSeals

            Pumps and compressors can  leak at the point  of  contact
 between the moving shaft and the stationary  casing.  If volatile,
 the leaked product will evaporate to  the atmosphere.  Examples
 of nonleaklng pumps are-completely enclosed  or  "canned" pumps
 in which there-are no seals, diaphragm pumps in which a flexi-
 ble diaphragm prevents the product from contacting  the  working
 parts of the pump, and pumps with magneto-magnet drivers and
 no seals.

            The most common types of pumps used  in  the PCPI are
 centrifugal and reciprocating  pumps.  The seals normally used on
 them are mechanical or packed.  Packed seals consist cf a  fibrous
-------
packing between the shaft and casing wall.  Mechanical seals con-
sist of two plates situated perpendicular to the shaft and forced
tightly together.  One plate is attached to the shaft and one is
attached to the casing.  Packed seals can be used on reciprocating
or rotating shafts; mechanical seals are for rotating shafts only,

4.1.8,1    Emission Characteristics

           A study of Los Angeles County refineries found centri-
fugal pumps -with packed seals lost 2.2 kg of hydrocarbons/day-seal
(4.8 Ibs/day-seal), centrifugal pumps with mechanical seals lost
1.4 kg/day-seal (3,2 Ibs of hydrocarbons/day-seal), reciprocating
pumps with packed seal,s lost 2.3 kg hydrocarbons/day-seal (5.4
Ibs of hydrocarbons/day-seal), .and compressors lost 4.1 •kg/day-
seal (8.5 Ibs of hydrocarbons/day-seal).  On an overall refinery
basis, these hydrocarbon emissions amount to 50 g/m3  (17 lb/1000
bbl) refinery feed for pumps and 14 g/m3  (5 lb/1000 bbl) refinery
feed for compressors.9   Pump seals are one of the principal sources
of emissions in oil production operations.  They contributed 687,
of the hydrocarbons emitted from one California oilfield.10

4.1..8,2    Control Technology

           Both packed and mechanical .seals inherently  leak but
emissions from centrifugal ptanps can be reduced 337, by  replacing
packed seals with mechanical seals.  Emissions from dual mechani-
cal seals can be eliminated by using a circulating, inert fluid
between the two seals at a pressure higher than that  on the pro-
cess fluid side of the pump; thus, any leakage is of  inert fluid
into the process stream.  According to several oil producers, the
highest temperatures in which mechanical  seals can be used ranges
from 210-330°C (410-608°F).  Emissions from reciprocating pumps
can be controlled by installation of dual packed seals  with pro-
visions to vent the volatile vapors that:  leak past the  first seal
into a vapor recovery system.
                               122
-------
           As mentioned previously, diaphragm, canned, and magnet-
drive pumps are not subject to leaks.  In a few circumstances,
installation of one of these pump types can be a cost-effective
means of eliminating emissions.

           Emissions from any kind of pump or compressor seal can
be minimized by frequent inspection and corrective maintenance.

4,1,8.3    Cost, Energy, and Environmental Impact of Controls

           According -to a recent estimate, the cost for install-
ing a mechanical seal' on an -existing pump, including a cooler, "la1'
bor, and mate-rials, is -about-, $2000-2500.11  The cost will be  lower
If-a cooler.. is not required...,.  Current:...trends  indicate that mechani-
cal seals are becoming more economical as a result of a huge  in-
crease in sales volume and. greater standardization of sizes..12
Total costs for a plant are bard to predict,  since the number of
pumps for which a changeover is indicated will vary from plant ;to-'
plant.  Some of the capital cost will be  compensated by a cost
benefit from product recovery.'

          • No -cost information for dual seals is available from
the sources consulted.  A price comparison of the different 'types
of pumps is difficult.  The suitability of a pump will vary accord-
ing to the specific application.

           "No secondary environmental impact will be produced by
these controls..

4.1.9      Pressure Relief_ Devices

           The build-up of dangerously high pressures in process
units and storage vessels is avoided by use of pressure relief
                               123
-------
devices.  These include pressure relief valves (liquid),  safety
valves  (gas),  and safety hatches (gas).   The main difference
between liquid and gas service valves is that liquid valves open
in proportion to the amount of excess pressure applied,  while
safety valves pop fully open whenever the set pressure is exceeded.
The valves discharge to a blowdown system, a vapor recovery system,
or the atmosphere.

A.1.9.1    Emission Characteristics

           Fugitive emissions from pressure relief devices
occur when a valve not vented to an enclosed system seats im-
properly due to damage, wear, or corrosion of the seat or gasket.
Therefore, emissions are very dependent on the frequency and qual-
ity of maintenance.  Surveys indicate hydrocarbon leaks from re-
lief valves on refinery process vessels average 1.3 kg/day-valve
(2.9 Ib/day-valve).  Leaks from relief valves on pressure storage
tanks average 0.3 kg/day-valve (0.6 Ib/day-valve).  The storage
tanks had a higher incidence of leaks than the process vessels.
The average total quantity of volatile organics leaked from refin-
ery relief valves was 1.1 kg/day-valve  (2.4 Ib/day-valve).J3

4.1.9.2    Control Technology

           Emissions from pressure relief devices can be controlled
by manifolding to a vapor control device or a blowdown system.1"
For valves where it is not desirable, because of convenience or
safety  aspects, to discharge into a closed system, flanged blanks
called  rupture discs can be installed before  the valve.  Rupture
discs prevent the pressure relief valve from  leaking and protect
the valve seat from corrosive environments.15  Care must be  taken
in the  selection and use of rupture discs because they can affect
the operation of the relief device they are supposed to protect.
Monitoring and proper maintenance are also important control
techniques.
                               124
-------
4.1.9,3    Cost, Energy, and Environmental Impact of Controls

           Slowdown systems are discussed in Section 4.1.13.   In
stallation costs will depend on the length of piping required  to
connect the system.

           According to estimates by one oil producer,  cost of
rupture disks in 1975 in a refinery was $1000-1500 per  installa-
tion.16  Total costs for a plant will vary depending on the nuta-.
ber of installations.  Some portion of the capital cost will be
compensated by" a" "cost benefit frdta product
           The" -drily secondary environmental  impact will be 'asso-
ciated with  a  blowdown  system,  as  discussed  in Section 4.1.13.
 Flaring, products  containing sulfur may produce SOX emissions .
 Flaring  'also has  the "potential to  produce CO and NO   'emissions,
             * ,                                     X

 4.1.10     Wastewater Drainage System

            A refinery or chemical 'plant wastewater system treats
 water from a number of sources.  Aqueous waste streams include
 cooling water, process water and steam condensates,  storm run-
 off, blowdown, . water,,, _ sanitary- -wastes , and. ship ballast water.
 These streams- are' usually segregated into separate flow channels,
 Organics can enter these aqueous streams through leaks in pro-
 cess units,  spills, sampling, blind changing, and turnarounds,

 4.1.10.1  Emi s s ion Char act er i_s_t ics

           Every  element of the drainage system that  handles or-
 ganics- contaminated wastewater . is  a fugitive emissions source,
                               125
-------
Organics can evaporate from the large surface areas present in
the drainage ditches, oily water sumps,  oil-water separators, and
open basins.  Manholes on the sewer boxes also allow organics to
escape.  Every organic processed by the plant is a potential source
of fugitive emissions from the wastewater drainage system.

4.1.10.2   Control Technology

           Emissions from wastewater drainage systems can be re-
duced through minimizing the contamination of water with organics
and by enclosing some of the wastewater collection and treatment
systems.  Proper inspection and maintenance is necessary to mini-
mize organics contamination of the water.  Manhole covers can be
installed on all sewer and junction boxes.  In some cases it may
be practical to vent enclosed systems to vapor recovery units.
Whenever systems are enclosed, care would have to be taken to
avoid risk of explosion.

4.1.10.3   Cost, Energy, and Environmental Impact of Controls

          ..Costs for enclosing a .wastewater system will be site
specific.  Retrofitting'in older plants might require extensive
modifications.  In some cases, all existin-g facilities may have
to be replaced.

           The buildup of explosive concentrations in a covered
system must be avoided.  It may be necessary  to vent to a blow-
down system, as discussed in Section 4.1.13.  Vapor recovery
units, if used, will provide a cost benefit from product recov-
ery.  Flaring of material containing sulfur may produce SOX
emissions.  Flaring also has the potential to produce CO and NOX
emissions.
                               126
-------
           Oily wastewater treatment is discussed further in Sec-
tion 4.2.3.

4.1.11     Blind Changing

           Process plant operations sometimes require that a pipe-
line be used for more than one product.  To prevent leakage and
contamination of a particular product, other product-connecting
or product-feeding lines are customarily "blinded off."  Blinding
a line involves inserting a flat solid plate between two flanges---
of a pipe connection.  Spillage of product can occur when the
blind is inserted or withdrawn-.

4.1.11.1   Emission Characteristics -• •  '  '

           The magnitude of emissions  from pro-duct .spillage" during
blind changing is a function of the spilled product's vapor pres-
sure, type of ground surface, distance to the nearest drain, and
amount of liquid spilled.  A survey of refineries in Los Angeles
County17 determined that in 1958.hydrocarbon emissions from blind
changing varied greatly.  A two-month  log of emissions there indi-
cated an average emission rate of 1.0  g/m3 (0.29 lb/103 bbl) of
feed..18

4.1.11.2   Control Technology

           The most prevalent form of  control is the double block
and bleed valve.  This replaces the blind and does not allow pro-
duct spillage.  Any bleed valve effluent is sent to oily wastewate:
treatment.  This technology is currently in use in many U.S. re-
fineries and chemical plants.
                               127
-------
           Frequently, double block and bleed valves are not suit-
able substitutes for blinds.  If blinds must be used, emissions
from changing of the blinds can be minimized by pumping out the
pipeline and then flushing the line  with water before breaking
the flange.  Spillage can also be minimized by the use of special
"line" blinds in place of the common "slip" blind.  The survey of
Los Angeles County refineries indicated that spillage from line
blinds was 40% of the spillage for slip blinds.  In addition, com-
binations of line blinds in conjunction with gate valves allow
changing of line blinds while the pipeline is under pressure.19

4.1.11.3   Cost, Energy and Environmental Impact of Controls

           Cost information for double block and bleed valves
or "line" blinds is unavailable in the consulted literature.  No
energy is required for either control technique.  Oily wastewater
treatment is discussed in Section 4.2.3.  Product recovery from
separators and/or vapor recovery units provides a cost credit
and an indirect energy credit.

           Many plants already pump out and flush pipelines before
changing blinds.  Cost are  the cost of labor and the capital cost
for pumps and associated collection equipment.  Energy is requir-
ed for pump operation.  At  least a porjtjLon of the costs and energy
requirement is compensated  by-credits fr.om recovered products.
This control technique may  also be justifiable in terms of plant
safety.

           Water used to flush pipelines may be heavily contaminated
with organics.   It must be sent to the plant wastewater system be-
fore disposal (see Sections 4.1.10 and 4.2.3).  Large volumes of
water may overload a plant's system and result in pollution of
plant effluent water.
                               J.28
-------
4.1.12     Sampling

           The operation of process units is constantly checked by
routine analysis of feedstocks and products.  Samples are usually
collected by opening a small valve on a sample line and collect-
ing a certain volume of the liquid.  In large chemical plants and
refineries there are hundreds of sampling points throughout the
installation,

4.1,12.1   Emission Characteristics

           One of the greatest emission sources during sampling
is line flushings or purgings.  Since the sample tap is used fre-
quently, it is generally located conveniently at ground level.
This often necessitates'use of a long sampling line.  To obtain-.----
a sample representative of current operations, the operator must
flush out the volume of the sample line before filling his sample
container.  Liquid line flushings are often collected in an open
bucket; gas purges are vented to the atmosphere.  There is ample
time for evaporation of the volatile components from the liquid
material before it is dumped.                "  "

           In plants manufacturing hazardous chemicals, closed
loop sampling is employed.  In 'this method, sample taps are placed
across a pump or other source of pressure drop.  This allows the
flushing stream to return to the process.

           Studies in oil refineries have found that hydrocarbon
emissions from excessive purging of sampling lines can amount"to-
140-280 g/m-3 (50-100 lbs/103 bbl) of refinery feed,20 but generally
average 6.6 g/m3 (2.3 lbs/103 bbl) of refinery feed.21
                               129
-------
4.1.12.2   Control Technology

           One means for controlling the emissions generated by
purging sampling lines is the installation of drains and flushing
facilities at each sample point.  Conscious efforts to avoid ex-
cessive sampling in addition to flushing sample purges into the
drain have a significant impact on the emissions from sampling
operations.  Closed loop sampling is a technique that could be:
applied to all aspects of the PCPI,  as it is in hazardous chemi-
cals manufacture.

4.1.12.3   Cost, Energy, and Environmental Impact of Controls

           Costs for the installation of drains.and flushing facil-
ities will be..site specific.  Cost information for closed-loop
sampling is unavailable from the sources consulted.  Energy re-
quirements will be minimal.  For either system, costs and energy
are at least partially compensated by credits from product recovery.
Recovery is better from closed-loop sampling than from wastewater
treatment of sampling line purges.

           If -wastewater is adequately treated, there will be no
environmental impact from these controls.

4.1.13     Uncontrolled Slowdown Systems

           A blowdown system is a set of relief devices, piping,
and/or vessels used to discharge or collect gaseous and liquid
material released during process upsets or turnarounds.  In un-
controlled blowdown systems, gases and vapors are vented unburned
into the atmosphere.  Uncontrolled venting is more common in oil
and gas production operations because of the lack of need for ex-
cess gas at oil wells, or because of the remoteness of the pro-
duction site.  One estimate states that 207» of  the vented produc-
tion gas is vented without burning.22
                              130 .
-------
4.1.13.1   Emission Characteristics

           Emissions from uncontrolled refinery blowdown systems
have been estimated to be as much as 1.66 kg/m3 (580 Ib hydro-
carbon/103 bbl) feed.23  Because blowdown systems receive mater-
ial from all processing units within the plant, any volatile hy-
drocarbons found in the process streams could be emitted from the
blowdown system.  Those from production and gas processing opera-
tions are primarily lower molecular weight, saturated hydrocarbons.

4,1.13.2   Control Technology

           Blowdown emissions can be effectively controlled by
venting into atr integrated- vapor-liquid recovery system.  All
units and equipment subject to shutdown, upsets, emergency.vent-
ing, and purging are manifolded into a multi-pressure- collection _
system for flaring or reprocessing.  Discharges into the collec-
tion system are segregated according to their operating pressures"I
A series of flash drums and condensers arranged in descending
pressures separates the blowdown into vapor pressure cuts.  Such
an extensive system might be impractical for some facilities such
as offshore production locations where space is very limited.
Emissions from controlled blowdown systems have been estimated to
be 2.0 g/ia3 of refinery capacity (0.8 lb/103 bbl).2"

4.1.13.3   Cost, Energy, and EnvironmentalImpact of Controls

           Condensers and flares are discussed in Sections 3.4 and
3.5.  Vapor recovery may also be based on adsorption or absorption,
as discussed in Sections 3.2 and 3.3.  Energy requirements and
costs will be  site specific.  Smokeless flares will require extra
energy for the production of steam  (about 1.3 MJ/kg or 560 Stu/lb
of organic flared).2 5
                               131
-------
           Controls for a blowdown system are already employed
in several refineries.  For these applications they may be justi-
fiable for the cost credit and indirect energy credit from pro-
duct recovery or for plant safety.  This may not be true for other
industries in the PCPI or small refineries with less product to
recover.

          Flaring of any material containing sulfur may produce
emissions of SOX.  Flaring also has the potential to produce CO
and NOX emissions.

4.1.14     References

1.  MSA Research Corp.  Hydrocarbon Pollutant Systems Study,
    Vol.  1, Stationary Sources, Effects and Control.  Evans
    City, PA.  PB-219-073, APTD 1499.  1972.

2.  Battelie-Columbus and Pacific Northwest Labs.  Environmental
    Considerations in Future Energy Growth, Appendices L-X.
    Columbus, Ohio.  Contract No. 68-01-0470.  1973.

3.  Atmosphere Emissions from Petroleum Refiners:  A Guide for
    Measurement and Control.  U.S. DHEW, Public Health Services.
    Washington, D.C.  PHS Publication Number 763.  1960.  As
    cited in Environmental Protection Agency.  Compilation of
    Air Pollutant Emission Factors.  2nd ed. with supplements.
    Research Triangle Park, NC.  1973.

4.  Instrumentation for Pollution Control Pollution Engineering
    9:1,  20-22  (January 1977).

5.  Hannon, John.  Private communication.  Ingersoil-Rand.
    Dec.  1976.
                               132
-------
 6.   Burklin,  C.  E.,  R.  L.  Sugarek,  and C.  F.  Knopf.   Development
     of Improved Emission Factors and Process  Descriptions for
     Petroleum Refining.  Radian Corp.  Austin,  Texas.   DCN 77-
     100-086-02-03.   EPA Contract No. 68-02-1889,  Task 2.   April
     1977.

 7.   Burklin,  C.  E.,  Revision of Emission Factors  for Petroleum
     Refining.   Radian Corp., Austin, Texas.   DCN 77-100-086-02-08
     EPA Contract No. 68-02-1889, Task 2.  October, 1977.

 8.   Rosebrook, D. C., et al.  Sampling Plan for Fugitive Emis-
     sions  from Petroleum Refineries.  Radian Corp.  Austin, Tx.
     DCN 77-200-144-06-01.   EPA Contract No.  68-02-2147.  January,
     1977.

 9.   Atmospheric Emissions From,.Petroleum Refineries.  A Guide
     •for Measurement and-Control.  Public Health Service.   Wash-
     ington,  D.Cv  PHS No.  763.  1960.

10.   Reference 1.

11.   Letter,with."attachmen-ts from H. H. Meredith (Exxon Company,
     USA) to- Robert T. Walsh (EPA) ,  January ,20,  1978.  p.  3, •

12.   Karrasik, Igor J.  Tomorrow's Centrifugal Pump.-- Hydrocarbon
     Processing, September 1977.

13.   Reference 3.

14.   Reference 7.
                                133
-------
   15.   Walters, R.  M.  How an Urban Refinery Meets Air Pollution
        Requirements.  Chemical Engineering Progress 6_8_(11) :   85,
        1972.

   16.   Reference 11.

   17.   Emissions to the Atmosphere from Eight Miscellaneous Source?.
        in Oil Refineries.  Rept. No. 8.  Joint District, Federal &
        State Project for the Evaluation of Refinery Emissions.  Los
        Angeles County Air Pollution Control District.  1958.

   18.   Reference 3.

   19.   Reference 7.

   20.   Laster, L. L.  Atmospheric Emissions From the Petroleum
        Refining Industry, Final Report.  Environmental Protection
        Agency Control Systems Lab.  Research Triangle Park, NC.
        PB 22-040.  EPA 650/2-73-017.   1973.

   21.   Reference 3.

   22.   Process Research, Inc.,  Industrial Planning & Research.
        Screening Report, Crude  Oil and Natural Gas Production
        Processes, Final Report.  Cincinnati, Ohio.  Contract No.
        68-02-0242.   1972.

23-24.   Reference 6.

   25.   Colley, J.  D., et al.  Energy Penalties Associated with En-
        vironmental Regulations in Petroleum Refining, Vol. 1.  Rad-
        ian Corporation,  Austin, Texas.  April 1977.
                                    134
-------
4.2       Petroleum Refining

          The petroleum refining industry converts crude oil into
more than 2500 refined products including liquefied petroleum
gas, gasoline, kerosene, aviation fuel, diesel fuel, fuel oils,
lubricating oils, and feedstocks for the petrochemical industry.
Petroleum refinery activities start with crude storage at the
refinery, include all petroleum handling and refining operations,
and terminate with storage of the refined products at the re-
finery .

          The petroleum refining industry employs a wide
variety of processes for the conversion of crude oil to
finished petroleum products.  The processing flow scheme is
largely determined by the composition of the crude oil feed-
stock and .the chosen slate of petroleum products.  .The ex-
ample refinery flow scheme presented in Figure 4.2-1 shows
the general arrangement used by U.S. refineries for major
refinery processes.  Few, if any, refineries employ all these
processes.          '

          .In general, refinery processes and operations can be
divided into five categories:  separation processes, conversion
processes, treating processes, product handling, and auxiliary
facilities.  The processes comprising each of these categories
are presented in the following sections.

          Petroleum Separation Processes

          The first phase in petroleum refining operations is
the separation of crude oil into its major constituents using
atmospheric distillation, vacuum distillation, and light ends
recovery..  Crude oil consists of a mixture of hydrocarbon con-
pounds 'including paraffinic, naphthenic, and aromatic hydrocarbons

                              135
-------
fc
 a)
 C
•r-l
14-1
 a)
 I
 o
 1-1
 4->
 0)
 cx
 
 QJ
 4-1
 C
 CO
 u
 4-1

 CO

U-l
 O

 a
•t-i
 4J


 I
 0)
X!
 a
CO
(N
 a;
 V4

 oo
-------
plus small amounts of impurities including sulfur, nitrogen,
oxygen, and metals.  Refinery separation processes use dis-
tillation, stripping, and absorption to separate these crude
oil constituents into common boiling point fractions.

          Petroleum Conversion Processes

          Product demand and economic considerations require
that less valuable components of crude oil be converted to more
valuable products using cracking, reforming and alkylation pro-
cesses.  To meet the demands for high octane gasoline, jet fuel,
and diesel fuel, low value residual and fuel oil components are
often converted to gasoline and lighter fractions.

          Petroleum Tr&ating Processes

          Petroleum treating processes convert .olefins and diole-
fins to saturated hydrocarbons, separate fractions for further
processing, and remove .obj-ectionable elements.  Treating also
includes gasoline treating processes such as caustic washing,
acid treating, copper sweetening, hydrogen treating, etc.  Objec-
tional elements removed frbm petroleum liquids include sulfur,
nitrogen, oxygen, halides, and metals.  Separation includes aro-
matics extraction, deasphalting, dewaxing, and deoiling.

          Feedstock and Product Handling

          The refinery feedstock and product handling operation's
consist of storage, blending, loading, and unloading activitie's","
All feedstocks entering the refinery and all products leaving
the refinery are subject  to the refinery handling operations.
                               137
-------
          Auxiliary Facilities

          Auxiliary facilities include a wide assortment of
processes and equipment which are not directly involved in the
refining of crude oil, but which perform functions vital to the
operation of the refinery.  These include boilers, wastewater
treatment, hydrogen plants, sulfur recovery units, and cooling
towers.  Products from auxiliary facilities (clean water, steam,
process heat, etc.) are required by the majority of refinery
process units.

          Emission Sources  •••--      -  -

          Sources of  hydrocarbon emissions  found  in petro-
leum refineries, .are listed  in .Table 4.2-1.  Included  in
this table are sources common to the  petroleum and chemi-
cal industry.  These  are  discussed in Section 4.1.  Con-
trol methods  and cost, energy, and environmental  impact  of
control  are presented in  the following Section 4.2.1  through
4.2.13.

4.2.1     Pres.su.re .Relief Systems

          Pressure relief systems are common to many  operations
in the petroleum and  chemical industries, and are presented
as a common source of emissions in Section  4.1.9.

4.2.2     Slowdown Systems

          Blowdown systems  are found  in many phases of the
petroleum and chemical industries, and are  described  in  Section
4.1.13.
                              138
-------
      TABLE 4.2-1.   HYDROCARBON EMISSION SOURCES FOUND
                    IN PETROLEUM REFINERIES
                                      •3
               Pressure Relief Systems
               Slowdown Systems3
               Oil-Water Effluent Systems
               Pumps and Compressors3
               Pipeline Valves and Flanges3
               Vacuum Jets
               Air Blowing
               Cracking Catalyst Regeneration
               Boilers and Process Heaters
               Chemical Treating
               Compressor Enginesa
               Miscellaneous Catalyst Regeneration
               Blending
               Coking
               Cooling Towers8"
               Compressor Engines
               Drains,  Sumps,  Hot Wells
               .Blind Changing3
               Sampling3
               Storage"*5
aSee Section 4.1
bSee Section 4.5
                             139
-------
4.2.3     Oil-Water Effluent Systems

          Oil-water effluent systems found in refineries include
drainage systems and primary wastewater treatment facilities.
This section deals only with the primary treatment of oily
wastewaters; drainage systems are discussed in Section 4.1.
Oil-water separation equipment includes API separators, corru-
gated plate interceptors, flocculation units, and dissolved
air flotation  (DAF) units.

          The API separator is one of the major units employed
for separation of oil from refinery wastewater.  It is simply a
gravity settling device in which oil is skimmed from the liquid
surface and suspended solids are removed from the bottom.
Separation efficiency can vary from 50 to 1007. depending on  the
physical characteristics of the oil.  Corrugated plate inter-
ceptors (CPI)  operate on the principle that the controlling
parameter for  oil-water separation is the surface area per unit
flow.  CPI equipment provides surface area for oil-water contact
with parallel  plates of corrugated material.  The CPI  design gen-
erally provides better separation capability in a smaller  space
than the API separator. *                    .

          .Flocculation is a technique in which oil and organic
particles in wastewater are agglomerated by flocculating agents
in order to improve settling characteristics.  Two common
flocculants are alum and polyelectrolytes.  Polyelectrolytes
are polar, synthetic, water soluble organic polymers of high
molecular weight.2  While flocculation gives excellent removal
of oil and the added advantage of removal of other particulates,
it also involves higher capital and operating costs than the CPI
unit or API unit. 3
                               140
-------
          Air flotation is a waste treatment process in which
air is dissolved into the water to aid in oil-water separation.
In some units, air is induced into the waste by surface agita-
tion or transfer from vessel to vessel through Venturis.  In
others, air under pressure (approximately 0.28 MPa or 40 psig)
is dissolved in the wastewater.  When the pressure is released,
millions of fine air bubbles less than 100 pm (0.004 in.) in
diameter attach themselves to the oil, causing it to rise to
the surface for removal.

4.2.3.1   Emission Characteristics
                                       i

          Emissions from oil-water effluent systems primarily"
result from the evaporation of volatiles from liquid surfaces
'open-.to the atmosphere... Such, surfaces exist in un-covered"-API  ••
separators, corrugated plate interceptors, and DAT units'.'
Those separators with a fixed roof and vapor space are als-o    ";"
subject to leaks at sampling and maintenance hatches and vents.
Floating roof-equipped separators can also leak around
hatches and vents, as well as around the roof seal, but the .".
lack of a vapor space eliminates much of the emission potential.

          Studies of refineries in Los-Angeles County indicate
that hydrocarbon emissions from sumps, drains, and API  separa-
tors range from' 30 g/m3 to 600 g/m3 capacity  (10-200 lb/1000
bbl capacity), with an average emission rate of 2700 kg/day
(3 tons/day).1*  A 1972 estimate set average nationwide  emissions
of hydrocarbons from refinery wastewater systems  at 0.3 kg/m3
refinery feed  (105 lb/1000 bbl).5  These emissions can  contain
any volatile hydrocarbon processed in the refinery.
                              141
-------
4,2,3.2   ControlTechnology

          The primary methods of controlling emissions from oil-
water effluent systems are minimization of the quantity of oil
leaked to the systems and enclosure of all system components.
The benefits of the first method are obvious.  Enclosure of sys-
tem components can be accomplished by using  floating roofs.
Another method is to vent fixed-roof units to blowdown or vapor
recovery systems.  Another technique that has received limited
application is floating an insulating material such as fiber-
glass foam .slabs on the .surface of the oil.

          Hydrocarbon emissions, from API separators can be re-
duced to 3 g/ms capacity  (0.01 Ib/bbl) by use of floating roofs
on API separators.6  A reduction in emis-sions to approximately
7 kg/m3  (23.3 Ib/bbl, 2 vol%) has been achieved by the insula-
tion technique.7  Floating roofs are recommended over fixed
roofs because they do not have ra vapor space in which explosive
mixtures can form.

4.2.3.3   Cost, .Energy, and Environmental Impact^ of Controls

          Costs for instailing-floating roofs, including labor
and materials, usually are more' than compensated by the cost
benefit  from product recovery.  However, in  some cases an  exist-
ing separator cannot be covered effectively  and a new facility
would have to be trailt to accommodate the floating roof.   Table
4.2-2 lists capital and annual costs for the installation  of
floating roofs on API separators in three different size re-
fineries .
                                142
-------
TABLE 4.2-2.  TYPICAL COSTS FOR FLOATING ROOFS ON API SEPARATORSa>
Capital
Refinery Size
1
9
31
,590
,840
,800
m3/s
m3/s
rnVs
day
day
day
( 10
( 61
(200
,000
,900
,000
bbl/s
bbl/s
bbl/s
day)
day)
day)
Costs ($)
27
82
167
,800
,800
,300
Annual
Costs ($/Yr)D
-6
-65
-240
,670
,830
,710
cl
 Costs are based on several assumptions,  See original reference
 for bases of estimates.
 Negative signs indicate that savings from the recovered product- ••'
 exceed the annual cost.
          Ins-tallation of-'fixed "-roofs was estimated to cost, .about,.
$135.00/m2 ($12.5/ft2), including labor and materials.  The capi-_
tal eos't is about'$62,800 for a typical, 16000 m'/day  (100,000
bbl/day) refinery.9 . This estimate does not-include the cost .of .
a vapor recovery system.  General discussions of costs for vapor
recovery and blowdown systems are provided in Section 3,0 and  -
4.1.13.  As with floating roofs, a cost, credit is produced by
product recovery.  Specific information is not available in the
consulted literature.

          There is no energy required for the use of floating
roofs.  Fixed roofs-, however, require energy for the operation
of-associated vapor recovery or blowdown systems.  General  dis-
cussions of these energy requirements are presented in Sections-
3.0 and 4.1.13.  For both types of roofs, an indirect energy
credit will be provided by recovery product.

         -The use of floating-roofs produces no secondary en-
vironmental impact.  Use of fixed roofs may result in SOX etrJLs-
sions if any organic materials containing sulfur are flared ia

                               143
-------
an associated blowdown system.  Flaring also may produce CO and
NOX emissions.

4.2.4     Pumps and Compressors

          Pumps and compressors are used extensively in the oil
and chemical industries.  They are discussed in Section 4.1.8.

4.2.5     Pipeline Valves and Flanges

          Valves and flanges are found in large quantities in
all phases of the oil and chemical industries.  A discussion of
their emissions and control is found in Section 4.1.7.

4.2.6     Vacuum Jets

          Steam ejectors (jets) are widely used to produce vacuums
in refinery equipment.  A steam nozzle discharges a jet of high
velocity steam across a suction chamber that.is connected to the
piece of equipment in which the vacuum is to be maintained.  The
existing steam and any entrained vapors are condensed by direct
water quench in a barometric condenser or by a surface condenser.
Any noncondensibles from this operation are vented either to the
atmosphere or a closed collection system.

          The largest unit operated under a vacuum is the vacuum
distillation column.  Topped crude withdrawn from the bottom of
the atmospheric distillation column is the feed to the vacuum
tower.  It is composed of high boiling point hydrocarbons which
decompose and polymerize to foul equipment when distilled at
atmospheric pressures.  In order to separate topped crude into
components, it must be distilled at very low pressure and in a
steam atmosphere.  Vacuum columns generally process between 20
                               144
-------
and 407o of the total crude capacity of the refinery depending on
type of crude.

4.2.6.1   Emission Characteristics

          Vacuum distillation columns process  significantly
greater quantities of hydrocarbons than  any  other vacuum opera-
tion in a refinery.  As a result, vacuum  jets on vacuum columns
are considered the .only potentially significant souce  of hydro-
carbon emissions from refinery vacuum equipment.  The  charge  to
the vacuum tower has been atmospherically distilled at high  tem-
peratures and contains little--or no material lighter than pentane,
depending on the type of..crude being processed.  Since the conden-
sation step takes place at relatively low temperatures and at "a
slight vacuum"'"Everything heavier  than butane  should condense and
exit with the water.  Thus,  any noticondensibles in the vacuum .sys-
tems- are produced only by the small degree of  cracking which may
take place in the unit's process heater.

          Vacuum units using barometric  condensers also produce
evaporative emissions of hydrocarbons from the oily condensate.
This occurs at the hot well, the'sump to which the oily condensate
is discharged.

          The refinery survey in Los Angeles County10  estimated
- hydro-carbon emissions from vacuum  jets  to be too small to neces-
sitate sampling.  A recent revision of  refinery  emission factors
reports an emission factor of 140  g/m3  of vacuum column feed
 (50 lb/1000 bbl of vacuum column feed).11

4.2.6.2   Control Technology

          Control technology applicable to  the noncondensible
emissions vented  from vacuum ejectors includes venting into

                                145
-------
blowdown systems or fuel gas systems and incineration in furnaces,
waste' heat boilers, or incinerators.  Vapor recovery units re-
cover condensible hydrocarbon vapors and return them to process
streams.  Incineration is accomplished by catalytic or direct
flame combustion.

          Oily condensate emissions can be eliminated by use of
mechanical vacuum pumps or surface condensers which discharge to
a closed drainage system.  Neither of these:alternate vacuum sys-
tems, however, are effective at reducing non-condensibles emis-
sions .

          Both noncondensibles and oily condensate can be mini-
mized by the installation of a lean-oil absorption unit between
the vacuum tower and the first stage vacuum je,t.12  The rich oil
effluent is used as charge stock and is not regenerated.

          The maximum degree of control attainable for the hydro-
carbon vapors from vacuum jets equipped with barometric conden-
sers is effectively 100%.13

4.2.6.3   Cost,Energy, and Environmental Impact of Controls

          The cost for controls will vary widely depending on
the quantity of vapor produced and  the maximum summer water tem-
perature.  A water quench with higher temperature water will re-
sult in richer vapors.  According to API, costs for installation
of a lean-oil absorption unit are only justifiable for treating
streams containing large quantities of non-condensibles-1*

          General discussions of incineration and vapor recovery
are presented in Section 3.0.  Costs for one installation, in-
cluding a compressor, piping to the nearest firebox, and  a suitable
                                146
-------
burner, amounted to approximately $50,000.  Costs for a condensate
receiver for a surface condenser were not included.  The system
was designed to handle 1 Mg/hr (2,200 Ibs/hr) of non-condensibles
from a vacuum distillation column treating 6,200 m3/sday (39,000
bbls/sday).l s  The energy requirement for a compressor will be
more than compensated by the energy gained from the incineration
of recovered vapors.l6

          Incineration of any material containing sulfur may pro-
duce SOX emissions.  Incineration also has the potential to pro-
duce CO and NOX emissions.

4.2.7     Air Blowing

  4.   '   There are currently two refinery processes in which
air is blown through petroleum products.  These are brightening
(moisture removal) of gas oil products (diesel fuels, furnace
oil) and air oxidation of asphalt.  Gas oil brightening is a
physical stripping of moisture from the petroleum  liquid; asphalt
blowing is a high temperature oxidation process.  Both produce an
exhaust air containing hydrocarbons and aerosols.

          Air blowing of gas oils is accomplished  in standard
packed towers or vessels.  The air is blown countercurrent to
the oil and strips the moisture from it.  Operating  temperatures
are usually low to minimize hydrocarbon vaporization and to pre-
vent product oxidation or degradation.  The exhaust  air stream
contains primarily the lighter hydrocarbon components of the gas
oil.

          Asphalt blowing processes oxidize residual oils (as-
phalts containing poiycyclic aromatics) in order to  increase
their  melting temperature and hardness.   Both batch  and continuous
                                147
-------
processes are employed.  Fresh feed and recycle are heated to
approximately 250°C (500°F) and charged to a vertical vessel.
Pressurized, preheated air (200-310°C or 390-590°F) is charged
into the bottom of the vessel through a sparger.  The reaction
is exothermic, and quench steam is sometimes required for tem-
perature control.  In some cases, ferric chloride or phosphorus
pentoxide is used as a catalyst to increase reaction rate and
impart special characteristics to the asphalt.

4.2.7.1   Emission Characteristics

          The quantity of hydrocarbon emissions from asphalt-
blowing units should be relatively small since the asphalt is
distilled at high temperatures before reaching the air-blowing
process.  Available data indicate that uncontrolled emissions
amount to 30 g/kg of alphalt  (60 Ib/ton) , which represents 2-470
of the asphalt charged.17  The production of asphalt in this
manner is limited; therefore, the total emission for the U.S.
is considered minor.  The operating conditions are favorable for
the production of extremely undesirable polynuclear aromatics.

4.2.7.2   Control Technology

          Emissions from air blowing can be reduced by vapor
scrubbing, incineration, or a combination of both.  These are
most often found on asphalt-blowing units.  Air-blown brighten-
ing units have been replaced  in many refineries with packed
vessels containing solid absorbents.18  These have no potential
for hydrocarbon emissions other than fugitive emissions.

          Vapor scrubbers condense steam, aerosols, and essen-
tially all of the hydrocarbon vapors.  A  disadvantage in water
scrubbing is the high volume  ratio of water-to-exhaust gas
                               148
-------
 required  to  remove  the  hydrocarbons.   Values  as  high as  13.4
 dm3/Nm3  (100 gal/1000 scf)  have  been  reported.19

          When an adequate  water supply  is  not available or when
 condensate handling may result in hydrocarbon emissions, incinera-
 tion of  the  vapors  by direct  flame contact  may be  used.   Incinera-
 tion may  be  accomplished in process heaters,  boilers or  fume
 burners.  Flame temperatures  in  these devices should be  maintained
 in the range of 680-840 C (1250-1550  F).20

          Hydrocarbon emissions  from  a controlled  asphalt-blowing
 unit are  negligible.21  -   -

 4.2.7.3   Cost, Energy,.and Environmental Impact of Controls -

          A-general discussion of vapor scrubbing  is presented'''
 in'Section  3.0.  Specific energy and  cost information is un-
 available.

          According to  a 1973 API estimate, costs  for installa-
 tion of  an  incineration system,  including a vapor  compressor,   ,,
 piping to an existing  firebox, and a  suitable burner, amount to
 approximately $20,000.   This  system will handle  emissions from
 asphalt  production  of  16 m3 (100 bbls)/12 hour  day.  Energy re-
 quired for  compressor  operation  will,  at least in part be compen-
•-sated by energy,"gained  from incineration of recovered fuel.

          A secondary  environmental  impact may  be  produced by
 vapor scrubbing. Additional  contamination of wastewater streams-
 will increase the chances of  volatile organic emissions  from the
 wastewater  treatment system (see Sections 4.1.10 and 4.2.3).  Con-
 taminants may be discharged with the  plant water effluent stream
 if the treatment system does  not have sufficient capacity to
 handle the  large volumes of scrubbing water.

                               149
-------
          Incineration of organic material containing sulfur may
produce SOX emission.  Incineration may also produce CO and MOX
emissions.

4.2.8     Cracking Catalyst Regeneration

          Catalytic cracking uses heat, pressure, and a catalyst
to convert heavy oils into lighter products.  Product distribu-
tions favor the more valuable gasoline and dis'tillate blending
components.  All of the catalytic cracking processes currently
in use can be classified as either fluidized bed or moving bed
units.

          Fluidized bed catalytic cracking  (FCC) uses a catalyst
in the form of very fine particles which behave as a fluid when
a gas is blown through them.  Fresh feed is preheated in a pro-
cess heater and introduced into the bottom of a verticle transfer
line  (riser) with hot regenerated catalyst.  Most of the cracking
reactions take place in the riser as the catalyst and oil mixture
flow upward into the reactor.  The hydrocarbon vapors are sep-
arated from the catalyst particles by  cyclones in the reactor.
The reaction products are sent to a fractionator for separation.

          The spent catalyst falls to  the bottom of the reactor,
is steam stripped to remove absorbed hydrocarbons as it exits
the reactor bottom and is then conveyed to a regenerator.  In
the regenerator, coke deposited on the. catalyst as a result  of
the cracking reactions is burned off in a controlled combustion
process with preheated air.  The catalyst is mixed with fresh
hydrocarbon feed and recycled.

          In the moving bed catalytic  cracking  (TCC) process
catalyst beads  (5.0 mm, 0.2 in.) flow  by gravity into  the  top
                                150
-------
of the reactor where they contact a mixed phase hydrocarbon feed.
Cracking reactions take place as the catalyst and hydrocarbons
move concurrently downward through the reactor to a zone where
the catalyst is separated from the vapors.  The gaseous reaction
products flow out of the reactor to the fractionation section.
The catalyst is steam stripped to remove any absorbed hydrocarbons
and falls into the regenerator where coke is burned from the
catalyst with air.  The regenerated catalyst is separated from
the flue gases, mixed with fresh hydrocarbon feed, and recycled.

4.2.8.1   Emission Characteristics

          The combustion rate in catalyst regenerators is con-
trolled by limiting the air to the regenerator.  This causes
partial oxidation, leaving CO and some unburned hydrocarbons
in the regenerator flue gas.

          Regenerator flue gas contains from 100-1500 ppm of
hydrocarbons22 depending on characteristics of the charge and
the type of catalytic cracker.  Hydrocarbon emissions from FCC
regenerators average 630 g/m3 fresh cat cracker feed  (220 lb.s/
1000 bbl) and hydrocarbon emissions from- TCC regenerators average
250 g/m3 fresh -cat" cracker feed  (87 Ibs'/lOOO bbl) .23  In 1968,
the estimated hydrocarbon emissions from FCC regenerators were
130 Gg/yr (143,000 tons/yr) and  from TCC regenerators were 9.1
Gg/yr  (10,000 tons/yr).2"

4.2.8.2   Control Technology

          There are three major  control measures  applicable to
the reduction of hydrocarbon emissions in the  flue gas of cata-
lyst regenerators.  The first of these is incineration in a
carbon monoxide waste-heat boiler.  By incinerating regenerator
                                151
-------
flue gas in CO boilers,  the hydrocarbon emissions are reduced and
valuable thermal energy is recovered from the flue gas.   Recent
oil company figures indicate that CO boilers lower hydrocarbon
emissions in the regenerator off gas to values ranging from 0 to
57 g/m3 (0-20 lbs/1000 bbl) of feed.25

         . TCC regenerators produce significantly less flue gas
than FCC regenerators and may not justify using a CO boiler.
A second control measure applicable to the flue gas from TCC
catalyst regenerators is incineration in a process heater box
or smokeless flares.  Hydrocarbon emissions in regenerator flue
gas are reduced to negligible quantities by incineration in
heater fire boxes and smokeless flares,

          The newest method of control is high temperature opera-
tion of the regenerator itself.  Newer designs operate at 760 C+
(1400°F) with a slight excess of air, converting 98+% of the CO
to C02 and completely oxidizing all hydrocarbons.26'27   However,
high temperature operation is not a widely available option for
existing units.  Existing regenerators often cannot withstand the
high temperatures necessary to burn off the coke unless they have
been originally designed to do so.

4.2.8.3   Cost, Energy, and. Envirpnmental___'Imp_iact of Controls.

          Controls for volatile organic emissions from catalyst
regeneration are the same as those used for control of CO emis-
sions.  If CO emissions are controlled, no extra energy or  costs
will be required for volatile organics control.

          CO boilers have been installed in many refineries as
energy recovery devices.  A typical CO boiler will recover  ap-
proximately 396 MJ/m9 (60 M Btu/bbl) of FCC fresh feed.28   In
                                152
-------
 all but small refineries,  costs of CO boilers are more than
 compensated by the fuel savings from heat recovery.  A compari-
 son of capital and annual  costs for installation of a CO boiler
 is  presented in Table 4.2-3.

           Flares can be used in small refineries where CO boilers
 are uneconomical.   Although there would be no cost benefit from
 energy recovery, as in a CO boiler, costs to construct an elevated
 flare are considerably less.   General discussions of energy require-
 ments and costs for flares are presented in Section 3.5

           High temperature regeneration has also been developed
 by  the industry as a method for energy recovery.  At a higher
 temperature, a greater portion of coke deposits are burned off
.the catalyst., •• This provides.: extra .sensible heat that., can. .be--- :•••-.-•,
 recovered .by: .waste heat".boilers.  It .also improves the operating
 efficiency "Of the catalytic cracking unit , resulting in an in-
 direct energy credit from .increased yield.  The total energy
 credit from the-operation of a typical high temperature regenera-
 tor is about 395 MJ/m3 ;(59.8 MBtu/bbl) of FCC fresh feed.30   In-
 creased metallurgy costs for a high temperature catalyst regenera-
 tor (for materials that can withstand the higher temperature) are
 at  least partially balanced by the cost benefit from increased
 yield.31   Elimination of the need  to construct a CO boiler is an
 indirect cost benefit.

           The control methods  all  involve oxidation  (combustion)
 of oTganic materials.  Any material containing  sulfur may  result  ...
 in..emissions of SO  .  Combustion may also produce  NO   emissions.
 4.2.9     Boilers and Process Heaters

           Most refineries utilize steam boilers  to  supply  their
 process and utility steam requirements.  Equipment  requiring
 t
                                 153
-------
                                    TABLE  4.2-3.   TYPICAL  COSTS  FOR CO  BOILERS3' 2"
     Type of                                                                                             Annual Cost
  Installation             Refinery Size                   Catalytic Cracker Size         Capital  Cost($)     ($/Yr)b


  Retrofit       1,590 m3/sday   ( 10,000 bbl/sday)     493 m3/sday   ( 3,100 bbl/sday)        920,000        56,210


  New                           NAC                  4,930 m3/sday   (31,000 bbl/sday)      3,070,000    -1,26?,600


  Retrofit  i                    NAC              ;   . 4,930 m3/sday  (31,000 bbl/sday)      3,680,000    -1,086,600


  Retrofit      9,840 m3/sday  ( 61,900 bbl/sday)    3,050 m3/sday  (19,200 bbl/sday)      2,760,000    -   526,600
M                                                                        :

•^Retrofit     31,800 m3/sday  (200,000 bbl/sday)    9,860 m3/sday  (62,000 bbl/sday)      5,570,000    -2,702,000



   Costs are based on several assumptions.  See original reference for basts of estimates.

   Negative signs indicate that savings from recovered heat exceed the annual cost.

  °NA indicates that information was not available.
-------
large amounts of process steam includes light ends strippers,
vacuum steam ejectors, process heat exchangers, and reactors.
The steam demand for a typical gasoline refinery is approximately
114 kg/m3 (40 Ib/bbl) of refinery feed.  This steam demand re-
quires a boiler size of 0.35 GJ/m3 (53 MBtu/bbl) of refinery
feed.

          Process heaters are used extensively in refining
operations to heat and thermally crack feed streams prior to
separation and treating processes.  They are the largest com-
bustion source of hydrocarbon emissions in refineries.  The
total process heater demand for a modern refinery is approxi-
mately 1.79 GJ/m3 (270 MBtu/bbl) of refinery feed.32  However,
the process heater demand for older, .less efficient refineries
may reach 4 GJ/m3 (600 MBtu/bbl) of refinery feed.33

4.2.9.1   Emission Characteristics

          Refinery boilers and heaters are fired with the most
available fuel, usually purchased natural gas and refinery fuel
gas.  Sometimes, however, residual fuel oil is used.  A refinery
survey in California reported the emissions listed in Table
4.2-4.31*   The heating values of the fuels are included.35  In
addition, refinery carbon monoxide boilers are partially fired
with catalyst regenerator flue gas as a means of controlling
carbon monoxide  and  recovering  the heating value of carbon mono-
xide.  The hydrocarbon emissions  from burning  catalyst regenera-
tor-flue  gas  are not significantly different from  those  of burn-
ing refinery  fuel gas.
                                155
-------
  TABLE 4.2-4.  HYDROCARBON EMISSIONS FROM REFINERY BOILERS
                AND HEATERS36
Fuel
Hydrocarbon
Emissions
Heating
Value
  Refinery fuel  gas          480 mg/Nm3             39.1 MJ/Nm3
                          (0.03 lb/103  scf)      (1050 Btu/scf)
  Distillate fuel oil       0.4 kg/m3               39 GJ/m3
                          (140 lb/103 bbl)      (5.9xl06  Btu/bbl)
  Residual fuel  oil          0.4 kg/m3               42 GJ/ms
                          (140 lb/103 bbl)      (6.3xl06  Btu/bbl)
           Because  of  the  increasing  cost of gas  and  fuel, re-
 fineries  in  the  future may  elect  to  fire process heaters with
 unrefined vacuum residual,  which  is  a  lower grade  of fuel.   Va-
 cuum residual may  produce slightly greater hydrocarbon, SOX, and
 NOV emissions than refined  fuel oils.
   X
 4.2.9.2    Control Technology

           Hydrocarbon  emissions  from  process heaters  and  steam
 boilers  can be minimized by adjusting the  fuel  to  air ratio  for
 optimum  fuel  combustion.   To  insure that optimum combustion
 conditions are maintained, some  refineries have installed oxygen
 analyzers  and smoke  alarms on heater  and boiler stacks.37 Ade-
 quate residence  time,  high temperatures, and turbulence are  essen-
 tial for complete combustion.

4.2.9.3  Cost, Energy,  and Environmental Impact of Controls

          Costs for oxygen analyzers and smoke alarms are unavail-
able from the sources consulted.   Optimum  combustion  conditions
                               156
-------
will yield maximum  fuel efficiencies.   Costs  for monitoring
equipment will  at least in part be  compensated by  the  cost bene-
fit from savings in fuel.

          No  secondary environmental  impact will be produced by
these  controls.

4.2.10   Chemical  Treating

           Chemical  treating  processes convert olefins  and diole-
 fins  to saturated hydrocarbons  and  remove objectionable elements
.from  petroleum products  and  feedstocks..  Objectionable elements
 removed include sulfur  (mercaptans) ,  nitrogen, oxygen, halidesr:  .
 and~ metals.   The processes can  be classified  as  sweetening.,
 acid/caustic  treating, and solvent  treating.   The  process se-
 lected for  a  given  application  depends on the material to be
 treated and the specifications  to be  met.

           Sweetening

           Chemical  'sweetening is  used to remove  mercaptans from
 such  hydrocarbons  as naphthas,  gasolines, distillates, kero-
 sene,  and  crude oil. Two*kinds of  sweetening are  used, extrac-
 tive  sweetening and oxidative sweetening.  In extractive sweet-
 ening processes, aqueous  NaOH or  KOH solutions extract the sul-
 fur by forming sulfides. - The solutions can be regenerated by
 steam blowing (reconversion  to  hydroxides and mercaptans) or by
 steam-air  blowing   (conversion to  hydroxides and disulfides).
 Sometimes  spent treating solutions  are disposed of rather than
 regenerated.   Disposal  is often preceeded by inert-gas stripping
 of the solution for trace hydrocarbon removal.
                                157
-------
          Oxidative sweetening converts mercaptans to disulfides
which remain in the hydrocarbon stock.  There are a variety of
catalytic processes for oxidative sweetening.  Catalysts include
copper chloride, sodium sulfide/lead oxide, sodium hydroxide,
and various organic inhibitors.   Air is used as the oxidizing
agent, and air blowing is used to regenerate many of the catalysi
solutions.

          Acid/Caustic Treating

          Hydrocarbon streams are treated with acid to remove
aromatics,  attack olefins, remove sulfur, and dissolve resinous
or asphaltic substances and nitrogenous bases.  The two most
common treating agents are sulfuric acid and acetic anhydride.
The hydrocarbon is contacted with the acid and mixed thoroughly
to form an emulsion.  The emulsion is then allowed to settle
and break into two phases by coalescence, sometimes aided by
electrostatic precipitation.  Air blowing may be employed for
agitation.

          The use of sulfuric acid results in a hydrocarbon/
acid sludge.  The sludge is removed by clay filtration.  The
sludge is' often incinerated and the resultant S02 is used to
produce more sulfuric acid.  Another method of acid recovery
is the hydrolysis-concentration process.  Hot gases from the
combustion of oil or gas are bubbled  through the sludge, vola-
tilizing much of the hydrocarbon diluent and concentrating the
acid.  The acid is then cooled for reuse or sale.  The off
gases pass through a mist eliminator  and are discharged to the
atmosphere.
                                158
-------
          Caustic is also used to remove organic acids and as a
neutralizer following acid treatment.  The treating process in-
volves emulsification and separation, as in acid treating.  Treat-
ment is often followed by a water wash.  When used in a sweeten-
ing agent, caustic can be regenerated as previously described.

          Solvent Treating

          Solvent treating processes are applied primarily to
the extraction of undesirable components from lubricating oils.
They are  also used to separate petroleum fractions and to
remove impurities from gas oils.  Undesirable components
removed include unstable, acidic, or organometallic compounds
of nitrogen -and sulfur.  •

          Solvent and oil are contacted in a countercurrent
continuous extractor.  The raffinate and extract streams  are
steam-stripped to produce refined oil  and finished extract
streams.  The solvent is separated  from the oil ,and water by
settling  or  stripping and returned  to  the contactor.

4.2.10.1  Emission  Characteristics •

          There  are varied  sources  of  hydrocarbon  emissions
from  chemical treating processes.  Hydrocarbon  emissions  are
generated whenever  sweetening .processes are  accompanied by
air blowing .for  oxidation and regeneration.  The  stripping  of
hydrocarbons from spent  caustic  with an inert gas  is  a potential
emissions source.   If the acid concentration process  is used
in.conjunction with  acid treating, both SOi and hydrocarbons
can be emitted with  the  exhaust  gases.  Solvent treating
emissions are in  the form of evaporative losses that  occur
when  the  distillate  product is in contact with  the atnosphere.
                              159
-------
4.2.10.2  Control Technology

          Control of emissions from the air blowing regeneration
of spent chemical sweetening solutions can be accomplished by
steam stripping the spent sweetening solution to recover
hydrocarbons prior to the air blowing step.  The gaseous
effluent from air blowing can then be incinerated to remove
residual hydrocarbons.

          Emissions from the inert gas stripping of spent
caustic can be prevented by venting the gases to a flare or
furnace firebox.

          Hydrocarbons escaping from acid recovery operations
can be eliminated by using acid regeneration.  Regeneration
involves sludge incineration to product SOa followed by stan-
dard H2SOi, production.  If the acid concentration process is
used, the off gases from the demister can be vented to caustic
scrubbers for S02 and odorant removal, followed by incineration
in a firebox or flare.

4.2.10.3  Cost, Energy, and Environmental Impact of Controls

          General discussions of energy and cost requirements for
incineration, absorption (steam stripping), and flaring are
presented in Sections 3.1, 3.3, and 3.5.  No specific energy or
cost information is available. ^Energy and cost information for
acid regeneration is also unavailable from the sources consulted.

          Combustion of organics containing sulfur may produce
S0x emissions.  Steam stripping produces wastewater which must
be handled in the wastewater treatment system  (see Sections 4.1.10
and 4.2.3).
                              16Q
-------
4.2.11    Miscellaneous Catalyst Regeneration

          Unlike cracking catalysts which are regenerated con-
tinuously, other refinery catalysts are only regenerated periodi-
cally.  A steam and air mixture is introduced to the catalyst
bed, causing combustion of the coke deposits.  Hydrodesulfuriza-
tion, hydrocracking, reforming, and isomerization units all re-
quire periodic catalyst regeneration.38

4.2.11.1  Emission Characteristics

          The combustion of deposited impurities may produce
emissions similar to FCC catalyst regeneration, mainly CO and
unoxidized hydrocarbons..,--The--emissions--from catalyst regenera-
tion are not-significant-because of the infrequent occurrence
of regeneration operations.            ..•-••                  "  '   '

4.2.11.2  Control Technology     -•

          The principal control measure for hydrocarbons in
catalyst regeneration flue gas is incineration in a heater fire-
box or a smoke plume burner.  These devices reduce hydrocarbon
emissions to negligible quantities.  Use of these control pro-
cesses is not widespread, however, because of the lack of sig-
nificance of this emissions source.

4.2.11.3  Cost, Energy, and Environmental Impact of Controls

          General discussions  of energy and  cost requirements
for  incineration methods are provided  in  Section 3.1.

          Incineration  of  organics  containing  sulfur may produce
S0x  emissions.  Incineration also has  the potential to produce
 CO  and NOX  emissions.
                                161
-------
A.2.12    Blending Operations

          Refinery blending operations involve the mixing of
various components to achieve a product of desired characteris-
tics.   The most common blending operation in petroleum refining
is the final step in gasoline manufacturing.  Gasoline compo-
nents such as catalytic gasoline, refornate, alkylate, isomer-
ate, butane, lead, and dye are mixed in proportions required
to meet gasoline-marketing specifications.

          There are two methods of blending, batch and in-line.
Batch blending is accomplished in a blending tank (or tanks)
into which each component is added individually.  Mixing is
continued until a homogeneous mixture of the desired properties
is produced.  The final blend--is routed to storage tanks to
await transfer out of the refinery or pumped directly to trans-
portation facilities.

          Agitation in the blending tank is accomplished either
by an external circulation loop  (or loops) or by internal
propellers powered by external motors.  The propeller shafts
are sealed in the same ways as rotating pump shafts.  A special
case is the blending of butane into gasoline, wherein liquid
butane is sometimes charged through a  sparger ring  in the  bottom
of the blending tank.

          In-line blending can be either partial or  continuous.
Partial in-line blending involves simultaneous  combination of
stock components  in a mixing manifold.  Final additions and ad-
justments are made downstream or in a  storage tank.

          Continuous in-line blending  involves  continuous  and
simultaneous blending of all stock components and  additives in
                               162
-------
a mixing manifold.  Each component stream is controlled auto-
matically by a feedback control loop; the entire control system
is often under computer guidance.  There is no blending tank,
and storage capacity is often minimized by direct discharge of
blended products to transportation facilities or pipeline.

4.2.12.1  Emission Characteristics

          Agitation in batch blending operations increases the
evaporation of lighter components.  Thus, fugitive losses from
batch blending tanks are generally greater than thos'e from
similar quiescent storage tanks.

          Emissions from in-line blending are limited to fugitive-
leaks- from valves and flanges.

4.2.12.2  Control Technology

          Control technology for batch blending operations
includes floating roofs on blending tanks and replacement of
batch operations by in-line blenders.  Further discussion of
storage tank emission prevention is presented in Section 4.5.

          The introduction of in-line blending facilities will
reduce emissions.  Prevention of hydrocarbon leaks from in-line
blending systems can be reduced by proper inspection and main-
tenance of valve stem seals, flange gaskets, and pump seals.

4.2.12.3  Cost, Energy, and Environmental Impact of Controls

          In-line blending facilities are not usually economical
for small refineries; larger refineries usually already have  in-
line blending.  Specific energy cost and information is unavailable.
                               163
-------
          Storage tanks are discussed in Section A.5.  Valves,
flanges, and pump seals are discussed in Sections 4.1.6, 4.1.7,
and 4.1.8.

          No secondary environmental impact will be caused by
these control methods.

4.2.13    Coking

          Coking is a thermal cracking process which is used
to convert low value residual fuel oil to higher value gas oil
and petroleum coke.  Vacuum residuals and thermal tars are
cracked at high temperature and atmospheric pressure.  Products
are petroleum coke, gas oils and lighter petroleum stocks.   De-
layed coking is the most widely used coking process today.

          In the delayed coking process heated charge stock is
fed into the bottom section of a fractionator where light ends
are stripped from the feed.  The remaining feed is combined
with recycle from the coke drum and is rapidly heated in the
coking heater to a temperature of 480-590°C (900-1100°F).  Steam
injection is used to control heater velocities.  The vapor-liquid
from the heater is converted to coke in a coke drum which provides
the proper residence time, pressure, and temperature for coking.
Vapors from the top of the drum return to the  fractionator where
the thermal cracking products are recovered.  When the onstream
coke drum has been filled  to the proper capacity with coke, it is
taken offstream and quenched/purged with steam.  The drum is
opened when the temperature reaches the desired level, and the
coke is cut with high-pressure water.
                               164
-------
4.2.13.1  Emission Characteristics

          When the coke drum is opened large quantities of steam
and hydrocarbons may be released to the atmosphere.  More steam
may be produced by vaporization of the cutting water and by re-
lease of pockets of trapped steam/hydrocarbon vapors from cutting
operations.  The hydrocarbons may include polynuclear aromatics
and other hazardous compounds, as conditions within the coker are
favorable for their production.

4.2.13.2  Control Technology

          Hydrocarbon emission's from coking operations can be
minimized by venting the quenching stream to a vapor recovery
or blowdown system.  Once the drum cools to 1QQ°C  (212°F) , the,--
steam purge can be replaced by a'water flood.  Allowing further""
cooling to approximately ambient temperature will minimize steam
and hydrocarbon vaporization and escape when the drum is opened.

4.2.13.3  Cost, Energy, jtnd Environmental Impact of Controls

          The various methods of vapor recovery are discussed in
Section 3.0.  Blowdown systems are discussed in Section 4.1.13.
No specific- information is available.

          Flawing of organics containing sulfur in a blowdown
system may•produce SOX emissions.  Flaring also may produce CO
and N0x emissions.

4.2.14'.   References

1.  Bush, Kenneth, Refinery Wastewater Treatment and Reuse-.
    Chemical Engineering.  April 12, 1976, pp 113-118.
                               165
-------
2.  Franzen, A. E.,  V. G.  Skogan, and J. F.  Grutsch.  Tertiary
    Treatment of Process Water.  Chemical Engineering Progress.
    68(8), 65, 1972.

3.  Beychok, Milton R.  Aqueous Wastes From Petroleum and Petro-
    chemical Plants.  N.Y.,  Wiley, 1967.

4.  Atmospheric Emissions From Petroleum Refineries.  A Guide
    from Measurement and Control.  Public Health Services.
    Washington, B.C.  PHS No. 763.  1960.

5.  MSA Research Corp.  Hydrocarbon Pollutant Systems Study,
    Vol.  1, Stationary Sources, Effects and Control.  Evans City,
    PA.  PB-219-073, APTD 1499.  1972.

6.  Burklin, C. E. , R. L. Sugarek, and  C. F. Knopf.  Development
    of Improved Emission Factors and Process Descriptions for
    Petroleum Refining.  Radian Corp.  Austin, TX.  DCN 77-100-
    086-02-03.  EPA Contract No. 68-02-1889, Task 2.  April 1977.

7.  Litchfield, D. L.  Controlling Odors and Vapors From  API
    Separators.   Oil  and Gas :Journal.   Nov.- 1, 1971.

8.  Hart,  D., et. al.  Economic  Impact  of EPA's Regulations On
    the Petroleum Refining Industry, Volume 2.  Sobotka and Co.,
    Inc.,  Stamford, Connecticut.  April, 1976.

9.  "Control of Refinery Vacuum Producing  Systems,  Wastewater
    Separators  and  Process  Unit Turnarounds."   Environmental
    Protection Agency.   Research Triangle  Park,  N.C.   Publica-
    tion  No. EPA-450/2-77-025.  October 1977.   pp.  4-8 to 4-10.
                               166
-------
   10.   Emissions to the Atmosphere from Eight Miscellaneous Sources
        in Oil Refineries.   Rept.  No.  8.   Joint District,  Federal &
        State Project for the Evaluation of Refinery Emissions L.A.,
        Los Angeles County Mr Pollution Control District.  1958.

   11.   Reference 6.

   12.   American Petroleum Institute,  Committee on Refinery Environ-
        mental Control.  Hydrocarbon Emissions from Refineries.
        Washington, D.C.  API Publication No, 928, 1973.

   13.   Reference 4.                                      .    -.

14-15-'."  Reference 12. .  ... -    ..    -          -  --         ;;_-'•'•••"

   16.   Environmental Protection Agency.  Air Pollution Control
        Technology Applicable to 26 Sources of Volatile Organic
        Compounds.  Emission Standards and Engineering Division,
        Office of Air Quality Planning and Standards.  May 27, 1977.

   17.   Reference 12.

   18.   Daily, J. W.  Private Communication.  Standard Oil Company
        of California, Western Operations, Inc.  Oct. 12,  1976.

19-20.   American Petroleum Institute, Div. of Refining.  Manual on
        Disposal of Refinery Wastes, Volume on Atmospheric Emissions
        API Publication 931,  Washington, D.C., Chapters 5, 7, 8, 10
        19 published 1976; Chapters 2, 9, 15 published 1977.

   21.   Reference 4.

   22.   Environmental Conservation.  National Petroleum Council.'
        Washington, D.C. '1972.

                                   167
-------
  23.  Reference 12.

  24.  Reference 5.

  25.  Reference 6.

  26.  Fleming, James, Henry Duckham, and James Styslinger.
       Recover Energy with Exchanges.  Hydrocarbon Proc.  5_5(7) :
       101, 1976.

  27.  American Petroleum Institute, Refining Department.  Ameri-
       can Petroleum Institute Refining Department 41st Midyear
       Meeting, Los Angeles, CA, May 1976, proceedings.   Washing-
       ton, D.C.   1976.

  28.  Colley, J.  D.  Energy Penalties Associated with Environmental
       Regulations in Petroleum Refining,, Volume  1.   Radian  Cor-
       poration, Austin, Texas.  April 27, 1977.

>9-30.  Reference 8.

  31   Reference 27.

  32.  Radian Corporation.  A Program  to  Investigate  Various
       Factors in  Refinery Siting,  Final  Report.  Austin, Tx.
       Radian Project No. 100-129.   1974.

  33.  Reference 5.

  34.  Reference 4.

  35.  Environmental Protection Agency.   Compilation of Air
       Pollutant Emission Factors.   2nd  ed.  with supplements.
       Research Triangle Park, N.C. AP-42.   1973.

                                   168
-------
36. Reference 4.

37. Walters, R. M.  How an Urban Refinery Meets Air Pollution
    Requirements,  Chemical Engineering Progress  68X11):   85,
    1972.

38. Ciaffe, S. T., Catalyst Regeneration, Mr Pollution
    Engineering Manual, Public Health  Service.  Cincinnati,
    Ohio.  AP-40.  1967.
                               169
-------
4.3       Oil and Gas Production

          Both oil wells and gas wells may produce appreciable
quantities of oil, gas, and water or brine.  In fact, about one
sixth of the marketed natural gas is produced along with crude
oil.1  Wells are classified as oil wells or gas wells according
to the ratio of oil to gas produced.  For example, Texas lav? de-
fines an oil well as "...any well which produces one (1) barrel
or more of crude petroleum oil to each one hundred thousand
(100,000) cubic feet of natural gas,"2

          Although offshore and onshore, production are alike in
many ways, there are distinct differences.  Offshore production
operations have the added complications of space limitations,
greater capital expenditures, limited modes of access to facili-
ties, and the generally hostile- environment surrounding the fixed
or floating platforms on which the work must be done.  Because of
adverse conditions and the possibility of catastrophic failure,
offshore platforms are usually equipped with sophisticated safety
devices and manned by crews well trained for emergency situations,
In offshore production a centralized processing platform may serve
several wells in the same area  (as with onshore production) or
the entire .production may be shipped ashore by barge or pipeline
for processing.

          Oil Production

          The production and processing of oil for transport to
petroleum refineries involves recovery of well fluids, processing
for free gas separation, water  separation, and storage.  The
three methods of bringing the oil to the surface  are natural flow,
gas lifting  (injection of gas into  the flowing column), and me-
chanical lifting  (using subsurface  pumps of either a plunger or
                                170
-------
centrifugal type).% The oil from several wellheads is brought
together by a pipe gathering system into a central collection
manifold.  If the wells are not at equal pressures or are pro-
ducing heavy crudes, then the gathering system must provide for
pressure reduction or heating, respectively.

          Processing the well stream requires separation of crude
oil, gas and water.  Oil and gas separations are normally classi-
fied into either  one, two or three pressure stages.  The number
of stages depends on the pressure of the incoming gas/oil mixture;
the higher the pressure, the greater the number of stfages.  Hori-
zontal separators are usually used for high pressure, high gas-to-
oil ratios; while vertical separators are used for lower pressure
separation-  A separator can be either two-phase  (oil and gas) -or
three-phase  (oil, gas and water).  For three-phase.,separation, a
lower section of  the 'two-phase separators is modified for- three-
phase operations.  Recovered gas may require sweetening and/or
purification at a gas treating plant.  In remote  areas, gas may
be reinjected; if volumes are small or noncommercial, it may be
flared.  It can also be used for lease fuel.

          Separation of crude oil and free water  (usually waste
brine) is accomplished by gravity separation using either a three-
phase separator,  free water knockout, wash tank or settling tank.
Remaining water forms an emulsion which must be broken down in a
dehydration plant.  The four methods used in dehydrating emul-
sions are heating, chemical treating, electrical  coalescing, and
extended gravity  settling.  Residence times are usually on the. or'-
der of 2D minutes.3  The recovered water may be treated and used
..for repressuring,  or it may be returned to an abandoned formation
for disposal.  Additional water treatment may be  needed if it  is
disposed above ground.
                                17 L
-------
          Crude oil in the production field is most commonly
stored in both bolted and welded steel tanks, usually vertical
with a fixed roof.  Floating roofs are seldom used in the produc-
tion field..**   In addition the natural gas liquids processed from
the separated gas stream can be stored in high pressure horizontal
cylinders or spheres and under pressure in caverns in the earth1s
crust.  If the pressure is reduced, the chilled liquids may be
stored in lighter, insulated vessels above ground or in frozen
earth pits.

          Gas Production

          There are two types of gas fields.  One is the "dry"
gas field in which no hydrocarbons heavier than methane and ethane
are produced and the only processing required is dehydration and
acid-gas removal.  The other type is the "wet" or "condensate"
field where a relatively heavy hydrocarbon condensate is usually
produced with the gas.  Besides acid-gas removal and dehydration,
separation of these heavier hydrocarbons is  a necessary step in
achieving acceptable natural gas specifications.5

          There are over twenty methods available for the re-
moval of acid gas constituents such as carbon dioxide and hydrogen
sulfide.  Two of the more commonly used methods are absorption
with aqueous solutions of ethanolamines or alkali carbonates,
and dry bed adsorption with molecular sieves.  In the solution
system, the amine or carbonate solution flow countercurrent
to the sour natural gas in a packed or tray  tower.  Effluents
are sweet gas which is sent to a dehydration unit and HaS rich
absorbent which is regenerated by heating, pressure reduction or
inert gas stripping.  Molecular sieves can be used for the
removal of all polar contaminants present in the gas, including
sulfur- and oxygen-bearing compounds and water vapor.
                                172'
-------
           Dehydration is accomplished by either adsorption with
 a dry desiccant  (activated alumina, silica gel or molecular  sieves)
 or absorption with a glycol solution  (diethylene glycol  or tri-
 ethylene glycol).  Both systems provide for adsorbent/absorbent
 regeneration and represent proven gas dehydration technologies.
 This operation would complete the processing of gas produced from
 a dry field.  However for gas produced from a condensate field,
 a third step is required to remove the heavy hydrocarbons.

           Several processes are currently used for the removal
 of heavy hydrocarbons from natural gas.  These processes
 .usually involve various combinations  of absorption, refrigera-
 tion, compression, adsorption, factionation, cryogenic separa-.-•-•'•--••
 tion, and tu-rbo-expansion.  Separation-may occur between methane
 "and ethane or ethane an'd propane.  The. heavier hydrocarbons  are
 recovered as product streams.                ••••..        '

 4.3.1.    Emission Characteristics

           Hydrocarbon emissions from  the production and  on-site
 processing of crude oil and natural gas can  occur  from a number
 of sources.  For the most part, these emissions  consist  chiefly
 of the  lighter saturated -hydrocarbons and  the major contribu-
 tors are process  equipment and storage vessels  (see Section  4.4,
 Storage Tanks).   Table 4.3-1  is a hydrocarbon  emission  summary
•-for crude oil and'natural gas production.

           Oil Produetion

    ••-•-,..,    The evaporative losses  in production of  crude  oil   ' " ..  •
 'result in the emission of low molecular weight saturated hy-
 drocarbons.  Emission estimates for venting  and  flaring  based
 on 1972 data are  1.42 km3/yr  (50  billion ft3/yr)  or 6.2  Gg/day
 (6,800 tons/day).8

                                173
-------
           TABLE  4.3-1.   HYDROCARBON EMISSIONS FROM OIL  AND GAS PRODUCTION8•
         Source
Continuous or
Intermittent
   Disposition
                                                                               Comments
Oil and Gas Separation


Oil, Condensate Storage

Natural Gas Separation
 Intermittent     Vented or Flared


 Intermittent     Atmosphere

 Intermittent     Atmosphere
                      During upsets,  or  in remote, low
                      production areas

                      Leaks and ruptures

                      Leaks and ruptures in plant and
                      lines; kept to  a minimum by pre-
                      ventive maintenance
Natural Gas Liquids
Recovery
Gas Dehydration




Heaters and Boilers

Compressors and Pumps
 Intermittent     Market  (LPG, LNG)
                             Intermittent     Atmosphere
 Continuous


 Continuous

 Continuous
Waste Pit


Atmosphere

Atmosphere
Occur in absorber and absorber
refrigeration

Occurs during glycol  regenerator
overloading; can be recovered in
inlet liquid scrubber

Free liquids, H20,  and hydrocar-
bons from inlet scrubber

Combustion Exhaust

Leaks from mechanical seals  and
packing glands
Effluent Sumps
 Continuous
Atmosphere
Evaporation
-------
          Major sources of these hydrocarbon emissions include
evaporation from brine pits and tanks, improper flaring, and
leaks.  Typical hydrocarbon emission  factors for these opera-
tions and others are given in Table 4.3-2.

          For  every volume of oil extracted, an additional  two
to  three volumes of waste brine are produced.  Waste brine  may
contain some residual oil and usually has a concentration of dis-
solved solids  seven times that of seawater.  The most cocmon
method of disposal is re-injection, although approximately 28% is ••
dumped in rivers, unlined pits, non-potable water  sites, and ap-
.proved disposal sites.  All discharges into marine waters must be  .
approved by state and federal authorities.  Some treated effluent
is  used for livestock and irrigation.. The open disposal methods
allow free evaporation of hydrocarbons.  Waste water separators
may be used, but they also produce hydrocarbon emissions.   For
offshore production, the water is either cleaned before discharge
into the sea or pumped into tankers or pipelines for treatment on-
shore .1 2

          Leaks  can represent another significant  source of hydro-
carbon emissions and are  discussed  in Section 4.1.

          •Natural Gas Production

          Natural gas is  composed of  methane with  decreasing
amounts of  ethane, propane,  and heavier hydrocarbons.  Removal
of these heavier  components  is a  necessary  step  in producing
natural gas  for  pipeline  sales.   Hydrocarbon  emissions from na-
 tural gas processing  are  mainly fugitive  in nature and result  from
 leaks  in pumps, valves,  compressors,  and  other machinery.   These
 losses  have been  estimated at  3.0 g/normal m3  (190 lb/I06  standard
 ft3) of natural  gas processed  or  approximately  6.28 Gg/day  (6,920
                               175
-------
             TABLE 4.3-2.  TYPICAL HYDROCARBON EMISSION FACTORS
                           FOR CRUDE OIL PRODUCTION9'10'11
     Heater Treater
     Heater Treater - Combustion
     Emissionsa
     Steam Injection - Steam
     Generator Combustion
     Emissions*3
kg/106 m3 fuel

        0.128

kg/103 m3 crude
       (0.325)
(lb/106 ft3  fuel)
     (8)

(lb/103 bbl  crude)
     (0.114)
50% Brine with Oil
Water Flooding - Diesel Engine
Exhaust c
Vapor Recovery System
Wastewater Separators
Pumps
Compressors
Relief Valves
Pipeline Valves
Diesel Pump for Water Flooding
Miscellaneous Flaring and Fires
Storage Tanks
19.4
326
Neg.
22.6
211
10.9
22.6
33.1
20.3
2.17
11.1
(6.8)
(114)
Neg.
(7.9)
(73.8)
(3.8)
(7.9)
. (11.6)
(7.1)
(0.76)
(3.9)
SBased on heat requirement on 1 MG/m3 (15,000 Btu/bbl) natural gas fired.

 Burning produced oil.

clncludes emissions calculated from aldehyde emission factors.
                                     176
-------
short tons/day) in 1973.13  Hydrocarbon emissions can occur at
any point in the system which is open to the atmosphere.  Typi-
cal hydrocarbon emission factors for natural gas production are
given in Table 4.3-3.  These emissions are about 89% methane.
They contain no significant amounts of H2.

    TABLE 4.3-3.  TYPICAL HYDROCARBON EMISSION FACTORS FOR
                  NATURAL GAS PRODUCTION11*

Gas Well Compressor
'• Acid Gas Removal Unit
Glycol Dehydration
Refrigerated Absorption
Flare •- ••"'•
mg/m3
0.64..
0.10.^
0.03
0.32
0.13
(lb/106ft3)
(0.04)
(0.006)
(0.002)
(0.02) .....
(0.008)
4.3.2     Control Technology

          There are three sources of hydrocarbon.emissions in
the production of crude oil- and natural gas:  combustion of a
fuel, evaporation of a volatile liquid hydrocarbon, and miscel-
laneous process leaks.  Control techniques  for emissions from
evaporation and leaks are described in Sections 4.1 and 4.5.
Techniques for tire control of emissions from combustion are
described below an'd in Sections 4.1 and 4.13.

          Combustion sources include process heaters, diesel
engines, and heater treaters.  Proper application, installation,
operation, and maintenance of combustion equipment represents
the most practical means of lowering combustion emissions.
Hydrocarbon emissions resulting from combustion exhaust can
also be significantly reduced by  substitution of  clean burning
natural gas for distillate or diesel oil as fuel.  In the  case

                               177
-------
of heater treaters, other possible alternatives to accomplish
oil-water separation without combustion are chemical destabiliza-
tion, electrical coalescence, and gravitational settling.  It is
noted, however, that these alternatives are not always applicable.

4.3.3     Cost, Energy, and Environmental Impact of Controls

          Cost, energy, and environmental impact of controls for
oil and gas production are given in Sections 4.1, 4.5, and 4,13.

4.3.4     References

1.  Kantor, Richard H.  Trace Pollutants from Petroleum and
    Natural Gas Processing.  M. W. Kellogg Company- Houston,
    Texas.  June, 1974.

2.  Process Research, Inc., Industrial Planning and Research.
    Screening Report, Crude Oil and Natural Gas Production
    Processes, Final Report.  Cincinnati, Ohio.  Contract No.
    68-02-0242.  1972.                                .

3.  Chilingar, George V. and Carrol M. Beeson.  Surface Opera-
    tions in Petroleum Production.  American Elsevier.  N,Y.
    1969.

4.  Crockett, Edward P. and James K. Walters.  Letter to Don R.
    Goodwin, EPA, dated October 28, 1977.

5.  Cavanaugh, E.  C., et al.  Atmospheric Pollution Potential
    from Fossil Fuel Resource Extraction, On-Site  Processing,
    and Transportation.  Final Report.  Radian  Corp.  Austin,
    Texas.  Contract No. 68-02-1319.   1972.
                               178
-------
   6.   Reference 1.

   7.   Danielson, John A.  Air Pollution Engineering Manual, 2nd
       Edition.  Environmental Protection Agency.  AP-40.  May, 1973.

   8.   Burklin, C. E., et al.  Control of Hydrocarbon Emissions
       from Petroleum Liquids.  Final Report.  Radian Corp.  Austin,
       Texas.  Contract No. 68-02-1319.  1975.

   9.   Reference 5.

  10.   Stephens, Richard H., et al.  Atmospheric Emissions from Off-
       shore Oil and  Gas Development and Production.  Energy Resources
       Co., Inc..  Cambridge,.. Mas sachuse'tts.  EPA, 68-02-2512.  June  1977

  11.   MSA Research Corporation.  Hydrocarbon Pollutant Systems
       Study, Vol. 1.  Evans City, Pennsylvania.  1972 as cited in
       Reference 5.

.2-13.  Wilkins, G. £.• et al.  The Environmental Catalog of Indus-
       trial Processes, Vol. 1.  Final•Report.  Radian Corporation.
       Austin, Texas.  Contract No. 68-02-1319.  1976.

  14.   Reference 5.
                                 179
-------
4.4       Organic Chemicals

          The organic chemical processing industries (OCPI)
convert hydrocarbons obtained mainly from petroleum, coal, and
natural gas into synthetic intermediates and products.   During
1974 nearly 64 Tg (1.4 x 1011 Ib) of chemicals with a value of
approximately 7 billion dollars were produced in the United
States.1  Table 4.4-1 is a list of the synthetic organic chemicals
with the highest production volume in 1976.   The primary raw
materials for this industry are ethylene, propylene, butylenes,
benzene, toluene, xylene, natural gas, and natural gas liquids.

          Organic pollutants may be emitted to the atmosphere
from organic chemical processing in various ways.  Vented gases
from various processing operations may contain organic compounds.
Vents are required for removal of by-prpducts or inerts and for
pressure control during plant upsets.  Other sources of hydro-
carbons include evaporation from storage tanks, loading and
unloading facilities, sampling, spillage, processing equipment
leakage, barometric condensers, cooling towers, equipment blow-
down, and miscellaneous sources.

          The volatile organics in vent streams can be controlled
by conventional methods of controlling organic atmospheric
pollutants from stationary sources, i.e..combustion, condensation,
adsorption, absorption, and process modifications.  These controls
can be used to achieve as much as 90 to 100 percent removal
efficiency.  In most cases, study is required to determine the
economically feasible reduction potentials for specific processes.

          Descriptions of the production of several organic
chemicals are included in the following Sections 4.4.1  -  4.4.8.
                              180
-------
TABLE 4.4-1.  THE MOST SIGNIFICANT SYNTHETIC ORGANIC
       CHEMICALS BY PRODUCTION VOLUME IN 19762
Production
Chemical
Ethylene Bichloride
Urea
Styrene
Methanol
Ethylbenzene
Vinyl Chloride
Formaldehyde (37% by weight)
Terephthalic Acid
Hydrochloric Acid
Ethylene Oxide
Ethylene Gly col
Butadiene (1,3-)
p-Xylene
Cumene
Acetic Acid
Phenol
Cyclohexane
Acetone
Propylene Oxide
Isopropyl Alcohol
Tg
3.60
3.50
2.86
2.83
2.78
•2.62
2.55
2.29
2.21
1.90-
1.53
1.48
1.45
1.22
1.10
0.99
0.99
0.87
0.82
0.78
(10'lb)
7.92
7.72
6.30
6.24
6.13
5.77
5.62
5.05
4.86
4.18
3.36
3.25
3.20
2.69
2.43
2.18
2.18
1.92
1.80
1.72
                         181
-------
The organic chemicals chosen have been the subject of industry
surveys and reports.  They are only a few of many significant
chemical processes, however.  Their inclusion indicates only
that hydrocarbon emissions and controls have been studied and
characterized for these processes.  Most emissions data from the
referenced reports are several years old.  It is believed that
current emissions are lower, due to increased usage of controls
and improved processing methods.  There is additional work in
progress directed at better characterization of organic chemical
emissions and their control.

          The following descriptions concentrate on the major
process emissions.  Fugitive, storage, loading and unloading
emissions are discussed in  Sections 4.1, 4.5, and 4.6, respec-
tively.  Flow sheets included show only  the major process streams
and no auxiliary equipment.

           Costs, energy requirements,  and environmental  impacts
of the major control technologies for volatile  organic chemicals
are  included in Section 3 of this report.   Costs and energy re-
quirements  developed for  specific organic chemical production
processes  are included in the  following  discussions  when they
were  available.  In addition,  comments on possible environmental
problems encountered with the use of  control  devices are made.
The  data are very  specific, however,  and are  not meant to be
applied to  other industries.  All cost estimates and energy re-
quirements  are  based on assumptions;  the references  cited should
be consulted for the bases of  the estimates.

4.4.1     Acrylonitrile by Propylene  Ammoxidation

          Acrylonitrile is produced  in the U.S.  by the Sohio
fluid bed  catalytic process.  Figure  4.4-1 is a simplified  flow
sheet of the process.  Air, ammonia,  and propylene are fed  to a
                               182
-------
              PROPYLENE•

                AMMONIA

                   AIR
CO
                                           FEED
                                           WATER
                MAIN
                VENT
                                                                                CRUDE
                                                                             ACRYLONITRITE
1




|





1
WASTEWATER
r

|

L
SORBENT




I


                          CATALYTIC
                           REACTOH
 QUENCHER/
NEUTRALIZER
                                                                                 WET
                                                                              ACETONtTRILE
ABSORBER    STRIPPER
                                                                                                        LIGHT ENDS TO FLARE
                                                                                                            ACRYLONITRITE
                                                            RESIDUE
                                                                                                           ACETONITRILE
                                                                                         WATER     RESIDUE
                                                                                     MULTISTAGE FRACTIONATION
                               Figure 4.4-1.   Flow  diagram for the  Sohio process
                                                   for acrylonltrile  production.
-------
reactor at 140-310 kPa (5-30 psig) and 420-530°C (780-980°F) to
form acrylonitrile by ammoxidation.   The chemical reaction may
be represented by the equation shown below.

          2CH2=CH-CH3 + 2NH3 + 302 •* 2CH2=CH-CN + 6H20

No recycle is required, as the reaction is virtually complete.
The reactor effluent is sent to a water quench tower in which
acid is added to neutralize the remaining ammonia.  Reaction
products are recovered in a water absorber-stripper system.
Acrylonitrile is then separated from by-products in a series of
distillations.  The first fractionation of crude acrylonitrile
usually removes HCN as an overhead stream.  The acrylonitrile is
then dried and purified to 994-% in further distillation steps.
The wet acetonitrile is subjected to extractive distillation
using water as the extractive solvent.

          By-product streams may be processed to recover high
purity HCN and acetonitrile for sales.  The by-product streams
which are not sold are incinerated.  The amounts incinerated are
determined by market demand; excess by-product is incinerated.
Currently, two acrylonitrile producers market or have plans to
market acetonitrile.  All of the producers market HCN.  Fifth
percent of the HCN is sold; forty percent is incinerated.3

          Aqueous wastes from the quench tower and from the
extractive distillation of acetonitrile are sent  to a settling
pond prior to disposal by deep well injection.

          There have recently been two catalysts in use:
Catalyst 21 and Catalyst 41.  Although the yields are about the
same for the two catalyst systems, Catalyst 41 provides for
better  utilization of ammonia and requires less oxygen.   All
                               184
-------
acrylonitrile producers have switched to Catalyst 41 or are
in the process of switching.

4.4.1.1   Emission Characteristics

          Hydrocarbon and organic chemical emissions may be
encountered at the absorber vent, at the fractionation column
vents, at the settling pond, at the incinerator stack, and at
storage tank vents.  The estimated total volatile organic
emissions from acrylonitrile plants in the U.S. are presented
in Table 4.4-2.

           TABLE  4.4-2.   ESTIMATED VOLATILE  ORGANIC
           EMISSIONS  FROM ACRYLONITRILE  PRODUCTION"
Emissions - •-•
Catalyst system
Catalyst 21
Catalyst 41
kg/kg acrylonitrile
0.1650
0.1071
Mg/yr
82. 3x10 3
53x10 3
(10s lbs/yr)a
(181.5)
(117.8)
 Assuming 499 Gg/yr (l.lxlO9 Ib/yr) production

The primary gaseous air emission occurs at the absorber vent.
Incinerators have been installed on this vent stream in at least
two plants.  Table 4.4-3 contains a typical absorber vent gas
composition for a 90 Gg/yr  (200xlOs Ibs/yr) acrylonitrile plant.
Table  4.4-4 is  a  list of emission  factors  for absorber vent
emissions.

         The  fractionation  column  vent  stream contains seme
nitriles.  These  gases  are  usually incinerated.   The  vent  stream
flow rate  is  small.
                               185
-------
  TABLE 4.4-3.   TYPICAL ABSORBER VENT GAS  COMPOSITION FOR A
           90  Gg/yr (200x106  Ib/yr)  ACRYLONITRILE PLANT
                       USING  CATALYST 41s
Average Flow Rate
Component
Carbon dioxide
Carbon monoxide
Ammonia
Propylene
Propane
Hydrocyanic acid
Acrylonitrile
Acetonitrile
Nitrogen and argon
Oxygen
Water
NOX
kg/hr
3,784
1,359

426
676
5.4
2.7
73
73,789
876
7,799
.45
88,790
(lb/hr)
( 8,342)
( 2,996)

( 939)
( 1,491)
( 12)
( 6)
( 160)
(162,677)
( 1,931)
( 17,195)
( 1)
(195,750)
  TABLE 4.4-4.  EMISSION FACTORS FOR ABSORBER VENT GAS FROM
        ACRYLONITRILE PRODUCTION USING CATALYST 41fr
         Component                      Emission factor3
                                       (g/kg, lb/1000 Ib)
   Nitrogen                                  5,865
   Oxygen                                      103
   Carbon dioxide                              185
   Carbon monoxide                              79.3
   Cs-Hydrocarbons                              55.0
   Acrylonitrile             "~                   0.039
   Acetonitrile                                  0.625
   Hydrogen cyanide                              0.275
**
 Emission factors based on actual field sampling

                              186
-------
          Storage losses are another source of hydrocarbon and
organic chemical emissions.   Acrylonitrile and acetonitrile have
vapor pressures in the range of 21-35 kPa (3-5 psi) at ambient
temperature.  The storage tanks may be vented to the atmosphere,
but in some cases recovery systems are employed for safety
reasons.  The propylene is stored in sealed pressure storage
tanks equipped with relief valves that discharge to a flare.
Noncondensibles and some HCN from HCN tanks are also vented
to a flare.  Section 4.5 describes emissions from storage tanks.

          Results of field sampling indicate negligible volatile
organic emissions from incinerator stacks in acrylonitrile
plants.

          Liquid wastes are held in a settling pond before they
are disposed of in injection wells.  Organic chemicals in the
wastes are emitted to the atmosphere.

4.4.1.2   Control Technology

          The absorber vent gas emissions may be controlled
with a combustion device such as a CO boiler, thermal incinera-
tor, catalytic incinerator, or flare.  Catalytic incinerators
and combined liquid-gaseous incinerators are in operation.

          Organic emissions in fractionation column vent gases
may also be controlled by combustion.  Flaring is the generally
accepted procedure in this case because the volume is small.'
Indications are that this control method is practiced widely
in the industry.  It is estimated that more than 90 percent of
the combustibles are burned by flaring.7
                              137
-------
          Emissions from the settling pond are reduced by
covering the surface with a high molecular weight oil.8

          For control technology for   storage tank emissions
see Section 4.5.

4.4.1.3   Cost, Energy, and Environmental Impact of Controls

          Although discussions of energy requirements, environ-
mental impacts, and cost data for the combustion devices men-
tioned are located in Section 3, energy and cost data for this
specific process are included in Table 4.4-5.  The data were de-
veloped for a typical acrylonitrile plant producing 90 Gg/yr
(200 x 10  Ib/yr) in 1973.  Energy requirements and costs for
adding lube oil to a pond are probably minimal.

          Combustion of nitriles and HCN by flaring may result
in emissions of NOX.  If supplemental fuel contains sulfur com-
pounds, S02 emissions may also result.  The lube oil  layer used
as a control method for hydrocarbon emissions from the storage
pond contributes some volatile organic emissions.  The net result
is a decrease  in the total organic emissions from the pond and a
change in the  composition of emissions.

4.4.2     Formaldehyde  from Methanol with  Silver Catalyst

          Formaldehyde  is manufactured by  two processes.  One
employs a silver catalyst and the other a mixed metal oxide
catalyst.  The mixed catalyst process is discussed in the next
section.  The  overall reaction for making  formaldehyde  from
                              188
-------
                          TABLE  4.4-5.   ENERGY  AND  COST  DATA FOR CONTROL  OF EMISSIONS  FROM
                                              ACRYLONITRILE  PRODUCTION3»9
CO
VO
Waste, Strew*
Absorber vftnt
21.4 m-»/s
(45,370 act*)
It
Annual 1 zed
Energy Requirements Cost
Control Technique Fuel Electricity (1973)
Afterburner* generating 1.31 PJ/yr
steaa . (1. 24x10' 2 Btu/yr)
$355, 400 /yr
Product frac-
tional Ion vejat
0.033
(70 acfm)
                                   -
                                          Themal Incinerator
                                          Thenal Incinerator
                                          plua afterburner
                                          generating steam

                                          Flare
                                          Flare
                                          1.69 PJ/yr
                                          (1.60x10" Btu/yr)

                                          1.69 PJ/yr
                                          (1.60x10'* Btu/yr)
1.55 PJ/yr
(1.47x10"2 Btu/yr)

9.24 TJ/yr
(8.75x10*  Btu/yr)
                        1.5 TJ/yr
                        (430.000 kUh/yr)    $135,900/yr

                        1-5 TJ/yr
                        (430.000 kWti/yr)    $116,600 /yr
$619.500/yr

 ?20,500/yr
                        •y-product
                        Disposal
                        2. IS Mg/hr
                        (4743 Ib/ht)

                        HCN storage
                        tank vent   _
                        0.120  m3/s
                        (255 scfn)
                                          thermal Incinerator
                  Flare
                                          5.3 M/yr
                                          (5.0x10* Btu/yr)
3.2  TJ/yr
(3.0x10* Btu/yr)
                       0.86 TJ/yr           $70,700a/yr
                       (240.000 Ulb/yr)
                                                                                      56,400/yr
"Estimates fur 90 Gg/yr (200 tM Ib/yr) acrylonltrlle
 production.
 Coat  estimates are based on several assumptions.
 See original references.  These costs are based
 on 1973 dollars and conditions.  Current costs
 may be as much as 3 times those given.
                                                                              .Assuming steaai produced can be used.
                                                                              Includes excess capacity for all waate
                                                                              water atreaaa.
-------
methanol with a silver catalyst is shown in the following
chemical equation.

          2CH3OH + %02 -»• 2CH20 + H2 + H20

Figure 4.4-2 is a simplified flow diagram of the silver catalyst
process.

          The feedstocks are prepared before they are intro-
duced into the reactors.  Air is washed with caustic to remove
C02 and sulfur compounds and heated to about 80°C (180°F).   Fresh
and recycle methanol are combined, vaporized, and superheated to
about 70-80°C (160-180°F).  The treated air and vaporized
methanol are combined and sent to a battery of catalytic reac-
tors.  Some plants use a feed vs. effluent heat exchanger as
the next step.  Otherwise, effluent gases go directly to the
primary absorber, a packed tower.  The sorbent is an aqueous
solution of formaldehyde and methanol, part of which is recycled.
The other portion goes to an intermediate storage facility.
Noncondensibles and uncondensed vapors are sent to a secondary
absorber using distilled water as a sorbent.  The resulting
solution of formaldehyde and methanol is used as makeup for the
primary absorber.  Noncondensibles and associated vapors (metha-
nol, formaldehyde, methyl formate, methylal, CO) from the
secondary absorber are vented overhead.  The methanol and for-
maldehyde solution resulting from the primary absorber is
fractionated to yield 99+7. methanol and a 37%  (weight) solution
of formaldehyde containing less than 1% methanol.  The formal-
dehyde product may undergo additional treatment to remove
formic acid and to prevent polymerization during storage.
                              190
-------
                               MAIN PROCESS
                                  VENT
                   AQUEOUS
                   METHAMOL/
                  FORMALDEHYDE
                   SOLUTION
                                        «7» FORMALDEHYDE
                                           IAQUEOUSI
                          FDACTIONATION
Figure 4.4-2.
Flow diagram for silver  catalyst process  for
formaldehyde production.
-------
4.4.2.1   Emission Characteristics

          Volatile organic emissions from silver process formalde-
hyde plants are estimated to be 0.004k.g/kg  (0.004 Ib/lb) of 377.,
formaldehyde.  For an annual production rate of 2.68 Tg  (3xl06 Ib)
this amounts to 11 Gg/yr (24xl06 lb/yr).10  The main source of
volatile organic emissions is the absorber vent.  Another
identified source is the ejector exhaust from the fractionation
column.  A typical absorber vent gas is presented in Table 4.4-6.
Storage emissions are reported to be low.11

    TABLE 4.4-6.  TYPICAL ABSORBER VENT GAS COMPOSITION  FOR
          A 45 Gg/YR (100 MM lb/yr)a SILVER CATALYST
                 PROCESS FORMALDEHYDE PLANT12
Component
Formaldehyde
Methanol
Hydrogen
Carbon dioxide
Carbon monoxide
Oxygen
Nitrogen
Water
TOTAL
Composition
mole 7o
0.07
0.28
17.72
3.69
0.66
0.35
74.35
2.88
100. 00
Flowrate
kg/hr
3
14
56
253
29
17
3,242
81
3,695
(Ib/hr;
( 7)
( 31)
( 123)
( 558)
( 64)
( 38)
(7,147)
( 178)
(8,146)
a377o Formaldehyde solution

4.4.2.2   Control Technology

          The use of a mist eliminator on the secondary absorber
effluent is standard practice in the industry.  The majority of
U.S. plants do not employ additional controls.  Combustion
devices (thermal incinerators and boilers) are used by a few
producers.  Combustion efficiencies are estimated at 99+%.'**
                               192
-------
           Several  other devices  are  available  for  controlling
 absorber vent losses.   Plume  burners are  applicable, but  they
 control only 907o of CO  and volatile  organics.  Water scrubbers
 share the disadvantage  of low control efficiency,  and  they have
 the additional problem  of causing  a  potential  water pollution
 problem.  Catalytic incinerators are also applicable although
 they have not been demonstrated.   They are estimated to have
 efficiencies similar to thermal  incinerators.11*

           In plants operating fractionation columns at reduced
 pressures, a vent  stream is emitted  through a  steam vacuum
 ejector or pump.  Water scrubbing  is practiced by  at least  one  '
 plant to control hydrocarbon  emissions from this  source.  Removal
 efficiency is in the range of 79-97  percent.15 Another plant
 reportedly recycles the vent  gases to the fractionation  column,
 and a small purge  stream is probably required. A condenser is
 used as a control  device in one  plant.

4.4.2.3    Cost, Energy, and Environmental Impact of Controls

           General  cost, energy,  and  environmental impact  informa-
tion is located in Section 3 for  incinerators,  boilers, condensers,
absorbers, and flares.   In addition to this general data some spe-
cific cost and energy data for control techniques  are  presented in
Table 4.4-7 for a 45 Gg/yr  (100 x 106 Ib/yr) formaldehyde plant em-
ploying a silver catalyst in 1973.

           Combustion control  methods involve the potential  for
N0x and CO formation and release  to the atmosphere.  Additionally,
if supplemental fuel contains  sulfur, S02 emissions will also re-
sult.  Water  scrubbers,  as  mentioned above,  are a  potential  source
of wastewater pollution.
                                193
-------
                      TABLE 4.4-7.  ENERGY AND COST DATA FOR CONTROL OF VOLATILE ORGANIC
                                    EMISSIONS FROM METHANOL PRODUCTION USING A SILVER CATALYST
                                                                      a,b,
     Waste Stream
Control Technique
       Energy  Requirements
_Fuel	Electricity
 Annualized
 Cost (1973)
VO
     Absorber vent
     gas    -,
     1.02  in /s
     (2170 scfm)
     Fractionator
     vent gas •»
     0.422  ra  /a
     (894 scfm)
Water scrubber
                        Thermal incinerator
                        Catalytic Incinerator
                        Plume burner
                        Steam boiler
Total recycle
Water scrubber
                           1.32 TJ/yr
                           (1250xl06 Btu/yr)

                           1.06 TJ/yr
                           (1000x10* Btu/yr)

                           1.85 TJ/yr
                           (1750xlO% Btu/yr)

                           -34.3 TJ/yr
                           (-32,500x10* Btu/yr)
                       0.11  TJ/yr
                       (30,000 kWh/yr)

                       0.11  TJ/yr
                       (30,000 kWh/yr)
                       0.36 TJ/yr
                       (100,000 kWh/yr)
                                          $8,200/yr
  $10,100/yr


  $14,100/yr


  $  6,800/yr


 ~$  3,100/yr

  $  2,100/yr

> $  2,100/yr
     .Estimates :are for a typical 45 Gg/yr  (100 MM Ib/yr)  plant,
      1973 dollars.
     CCosts are based on several assumptions.  See original reference.  Costs
     .dollars and conditions.  Current costs may be significantly higher.
      Does not include water treatment requirements.
-------
  4.4.3     Formaldehyde from Methanol with Mixed Catalyst

           The reaction for making  formaldehyde from methanol
  using  the mixed metal oxide catalyst is  shown in  the  following
  chemical equation.

                   CH3OH + %02 -»• CH20 + H20

           Methanol  is mixed with air and recycled vent  gas  and
  heated to 105-177.°C (220-350°F) .   The reaction takes  place  in
  the  presence of a mixed oxide catalyst at temperatures  between
  343eC  and 427°C  (6508F and 800°F).  The  heat of reaction  is
  removed by  circulating coolant.  A heat  exchanger cools the
'effluent gases to 105°C  (220"F) before they are quenched  in the
  absorber.   Water  is used as a sorbent to form a 37-53 percent
  solution.   Part of  the noncondensibles are vented from  the  top  ..
  of the  absorber,  and the remaining portion is recycled.  Figure
  4.4-3  is a  simplified flowsheet of the mixed oxide catalyst
  process.

  4.4.3.1    Emission Characteristics

             Volatile organic emissions from the process  are  esti-
  mated  to be 0.0149  kg/kg (0.0149 Ib/lb)  of 37% formaldehyde.  This
  amounts to  a total  emission rate of about 11.7 Gg/yr  (25.7x106
  Ib/yr), based on  785 Gg/yr (1,729x106 Ib/yr) mixed metal  oxide
  process capacity. 17

             The primary source of volatile organic emissions in
  a mixed oxide catalyst formaldehyde plant is the  absorber vent:
  The ..amount  of emissions is highly  dependent on recycle  ratio.
  Absorber vent gas compositions for recycle and nonrecycle opera-
  tions  are presented in Table 4.4-8.
                                 195
-------
                       RECYCLE
                AIR


          METHANOL
0%
                                             VENT
                                                          WATER
                                                            -+- 37% TO 51% FORMALDEHYDE
                         CATALYTIC
                          REACTOR
ABSORBER
                    Figure 4.4-3.  Flow diagram for mixed catalyst process
                                  for formaldehyde production.
-------
     TABLE 4.4-8.  TYPICAL ABSORBER VENT GAS COMPOSITION FOR
         A 45 Gg/YR.(100 X 106 lb/yr)a FORMALDEHYDE PLANT
                   USING MIXED OXIDE CATALYSTl°
Component
Formaldehyde
Methanol
Dimethyl ether
Oxygen
Nitrogen
Carbon dioxide
Carbon monoxide
Water
Total
Composition
Non-recycle
0.01-1.0
0-0.7
0.05-2.5
18.5-19.6
75.1-77.0
2.2-4.0
0.7-2,24
(vol%)
Recycle
0.03-0.15
0.05-0.2
0-0.53
5.3-18.1
73.9-89.2
0.03-0.9
0.28-1.9
5.1
Flowrate

Recycle
kg/hr (Ib/hr)
2.3 (
9.5 (
4.5 (
606 ( 1
5,893 (12
10 (
68 (
195 (
6,788 " (14
5)
21)
10)
,336)
,994)
22)
151) •
429)
,968)
 a37%  solution
           A vent on the reactor cooling system has been reported
as a source of volatile organic emissions in some plants.  Vola-
tile organic emissions from this source are less than 0.002 kg/kg
(0.002 lb/lb) formaldehyde (377.).19

           Most, of the storage tanks employed in formaldehyde facil-
ities vent directly to the atmosphere.  Emissions from this source
are said to be low, however.
4.4.3.2
Control Technology
           Industrywide utilization of recycling has resulted in
significant reductions in volatile organic emissions from this
process.  In addition to this process modification, mist elimina-
tors are employed in some absorbers.  Water scrubbers were reported
                                197
-------
in at least one plant on the absorber vent and on the storage tank
vents .   Water scrubbing is about 9970 efficient on the tank vents ,
while it is only 667o efficient when used on the absorber vent.
The low scrubbing efficiency for the absorber vent is due to the
presence of dimethyl ether, which is relatively insoluble in wa-
ter. Combustion devices (thermal incinerators, catalytic incinera-
tors, flares) could be applied for further emission reductions.
Thermal and catalytic incinerators have estimated efficiencies of
99+70, while flares have estimated removal efficiencies of about
907».2:

4.4.3.3    Cost, Energy, and Environmental Impact of  Controls

           General discussions are included in Section 3 for energy
requirements , costs , and environmental impacts for absorbers , in-
cinerators, and flares.  Some cost data and energy requirements
for control devices applied in a typical 45 Gg/yr (100 MM Ib/yr)
formaldehyde plant in 1973 are listed in Table  4.4-9  also.

          Combustion may produce NO  and CO emissions.  If supple-
mental fuel contains sulfur, SO* emissions will also  result.
Water scrubbing has the disadvantage of creating a potential
wastewater problem.

4.4.4      Ethylene Oxide

           Ethylene oxide is produced in the  direct oxidation
process by reacting air or oxygen and ethylene in the presence
of a silver catalyst.  The reaction is shown  in the following
chemical equation.
CH2-CH2 + %0i •* CH2 -
                                       -£Hz
                               198
-------
                   TABLE 4.4-9.
ENERGY AND COST DATA FOR CONTROLLING VOLATILE
ORGANIC EMISSIONS FROM FORMALDEHYDE PRODUCTION
WITH MIXED OXIDE CATALYST21'13' 22
Waste Flow
Stream Rate
^3 	
Absorber 2.26 m /s .
vent (4790 scfm)
gas
2.26 m3/s
(4790 scfm)
2.02 m3/s
(4270 scfm)
10 o
V° 2.02 m Is
(4270 scfm)
1.60 m3/s
(3385 scfm)
Control
Technique
Thermal incinerator
(no heat recovery)

Thermal incinerator
(40% heat recovery)
Catalytic incinerator
Flare
Water scrubber
o
For a typical formaldehyde plant producing
c
Energy Requirements Annualized
Fuel Electricity Cost (1973)
68 TJ/yr
(64,000xl06

40 TJ/yr
(3 8, 000x10 6
42 TJ/yr
(40,000xl06
68 TJ/yr
(64,000x10*

45 Gg/yr (100
0.144 TJ/yr
Bfcu/yr) (40,000 k.Wh/yr)

. O.i44 TJ/yr
Btu/yr) (40,000 kWh/yr)
0.144 TJ/yr
Btu/yr) .(4Q.OOO kWh/yr)
Btu/yr)
'• • ' '
x 10 Ib/yr) with mixed oxide
$36,600/yr

$29,600/yr
$26,700/yr
$31,700/yr
$19,900/yrd
catalyst.
Costs are based on several assumptions.  See original, reference.  -Costs are based on 1973
dollars and coridiLioris.  Current costs may be significantly higher.
Does not include water treatment requirements.       '  '.  \  '  ;•'••'
-------
C02 and HaO are by-products formed by oxidation of the ethylene
oxide product and by oxidation of ethylene directly.  Most of
the installations use air as the source of oxygen, but there is
a trend toward using pure oxygen.  The two processes are similar.

          In the air based process, ethylene,  air, small amounts
of oxidation inhibitors, and recycle gas are fed to a primary
reactor packed with silver catalyst.  Temperature control is
provided by circulating heat transfer fluid.   Effluent gas from
the primary reactor is cooled and compressed before it enters
the primary absorber which uses water as a sorbent.  Unabsorbed
gas passes overhead.  Part of the gas is recycled to the reactor,
but the major part goes to a secondary reactor and another
absorber.  Overhead gases from this secondary absorber may be
vented directly to the atmosphere; however,, the trend is toward
catalytic incineration.  The gases from the incineration may be
used to drive an air compressor.  The water solutions from both
absorbers are pumped to a steam stripper.  Ethylene oxide is
then purified by fractionation.  Purified ethylene oxide is
stored under nitrogen or under refrigeration.  Bottoms from the
fractionation are sent to waste disposal (see Section 4.15).
Figure 4.4-4a is a simplified flow chart of the air-based
process.

          Process flows for the oxygen process are very similar  .
to the air oxidation process.  A simple flow chart is included
in Figure 4.4-4b.  There are some important differences, how-
ever.  There is usually only a primary reactor and absorber.
Conversion of ethylene per pass is low, so that a larger recycle
stream is required.  A C02 absorber is required on a portion
of the recycle stream to control COz buildup.
                               200
-------
                               MAIM PROCEI8
                                 VENT
    PRIMARY
    REACTOR
                                           GO} HIGH
                                           VENT QA»
                                                          -*• ETHYLENE OXIDE
                                                    HEAVY
                                                    ENDS
                                                FRACTION* TION
Figure
Flow  diagram forv this production  of ethylene
oxide by oxidation of ethylene with air.
-------
ro
              rnmiM-

























1

•u
MM














M
rTOM












V*
,














:ycl

1H ^













e

• w
AISO














UN
MM







1













•




















*









'

CO
AMOI










,
WAI

• "

1
Mtn










,
ren
MAM
VIMT




















e
AltO








C(
rar
VE
a


WOKNE


I>1
MCNT



ETNTI
niABSI



>«
\at
NT
u
1

WATCH







LEW
DC
Mvcn

















AOUEOUt
OXIDE
               Figure 4.4-4b.  Flow diagram for the production of ethylene oxide
                               by oxidation with oxygen.
-------
4.4.4.1   Ends, s ion Char act er is tics

          Estimated average volatile organic emissions from
ethylene oxide manufacture are  0.02048 kg/kg (0.02048 Ib/lb)
ethylene oxide produced.  Total volatile organic emissions from
ethylene oxide manufacture are  about 39 Gg/yr (86xl06 Ib/yr),
based on 1.9 Tg/yr  (4,191xlOs Ib/yr) ethylene oxide produced in
172.23  Emissions are  produced  at the secondary absorber vent
and  at the  fractionation  tower  vent.  In plants using pure
oxygen, emission sources  are  the absorber vent and the CCh
absorption  system.  The  composition of the vent gas from the
secondary absorber  in  plants  using air is shown in Table 4.4-10.
Although the concentration of volatile organics is low, the-flow
irate is high, resulting  in significant amounts of hydrocarbon'"'.
emissions from  this vent.   -            _            .'        ••""

  TABLE 4.4-10.  TYPICAL COMPOSITION OF VENT .GAS FROM SECONDARY
       ABSORBER. IN  AN  AIR-BASED ETHYLENE OXIDE PLANT3.D2*
Composition
Component
Nitrogen
Oxygen
Methane
Ethane
Ethylene
Ethylene oxide
Carbon dioxide
Total
(mol Z)
80-90
0.5-4.5
0-0.9
0-0.1
TR-2.3
0-0.01
0-10
Average •
(mol %)
86.7
2.9
0.0
0.1
1.6
0.01
8.7
100.0
Average f]
(kg/hr)
59,629
2,278
•0
68
1,105
S
8,973
72,061
.ow rate
(Ib/hr)
131,460
5,024
0
150
2,436
17
19?782 •-•".
158,369
 dry basis
 90 Gg/yr (200xlOs Ib/yr) ethylene oxide plant using air feed
C32,402 scfm
                              203
-------
           A typical  composition of the overhead vent stream from
the fractionation tower  in plants using air is presented in Table
4.4-11. This stream is representative of air based plants only.
Vent streams from oxygen based plants are different in composition
and flow rate.  The vent gas  stream from the absorber in one oxy-
gen based plant is shown in Table 4.4-12.  The composition of  a
purge gas from the COz absorption system of the same plant is  pre-
sented in Table 4.4-13.

    TABLE 4.4-11.  TYPICAL VENT GAS FROM RECTIFICATION TOWER
           IN AIR-BASED  ETHYLENE OXIDE PLANT*>&25
Composition
Component
Nitrogen
Oxygen
Ethylene
Ethylene oxide
Carbon dioxide
Total
(mol Z)
13-25
1-26
2.5-8.0
0-1.0
62-80

Average
(mol %)
18
2
4.5
0.5
75
100.0
Average
(kg/hr)
181
23
46
8
1^131
1,389
flow rate
(Ib/hr)
398
51
101
17
2.491
3,058
 dry basis
 90 Gg/yr (200xl06 Ib/yr) ethylene oxide plant using air feed
C475 scfm
     TABLE 4.4-12.   VENT GAS COMPOSITION FROM ABSORBER  IN
           ETHYLENE OXIDE PLANT-USING OXYGEN FEED3•D•26
Component
Nitrogen, argon
Oxygen
Methane
Ethane
Ethylene
Ethylene oxide
Carbon dioxide
Total
(mol %)
16.2
7.3
1.5
14.2
13.5
0.0005
47.4

Plow
(kR/hr)
55
20
2
37
33
0.02
172
319
rate
(Ib/hr)
121
44
5
81
72
0.04
379
702
 dry basis
b90 Gg/yr (200xl06 Ib/yr)
                               204
-------
       TABLE 4-4.13.  PURGE GAS FROM C02 ABSORPTION SYSTEM. IN
             ETHYLENE OXIDE PLANT USING OXYGEN FEEDa>D'27
Component
Oxygen
Ethane
Ethylene
Carbon dioxide
Total
Concentration
(mol Z)
0.02
0.12
0.16
99.70

Flow
(kg/hr)
1
8
10
9,543
9,562
rate
(Ib/hr)
3
18
22
21.038
21,081
  adry basis
  b90 Gg/yr (200xl06 Ib/yr)

 4.4.4.2    Control Technology

            The vent streams described in the previous section are
 uncontrolled at some locations.  However, use of catalytic incin-
 eration to"remove ethylene oxide from.the fractionation tower
 vent gas is becoming-prevalent.  Efficiencies for ethylene oxide
 removal have been "reported as high as 99.9+7.,28

           Catalytic converters are used in at least two plants
and have been recommended as the best control system for emis-
sions from the secondary absorber vent in air oxidation plants.
They are designed to convext ethane and ethylene to C02 and
water.  The-exhaust gas may be used to drive a turbine.  Other
combustion devices also may be used to reduce emissions.  Com-
bustion in a steam boiler is practiced in at least one ethylene
oxide plant.  Thermal incineration would also eliminate volatile
organic emissions from the absorber vent, but applicability may
be limited by the low organic content of the stream.  The vent
from the fractionation column in air oxidation plants can be
incinerated, however.  It has been suggested that combination
and incineration of the absorber and fractionation vent streams
may be feasible.29  Flaring could be used, probably with the
                                205
-------
addition of fuel.  A 907o combustion efficiency is usually assumed
for this type of control method,30

4.4.4.3    Cost, Energy, and Environmental Impact of Controls

           Generalized costs, energy requirements, and environmen-
tal impacts of incineration devices and flares are included in
Section 3 of this report.  In addition there are some specific
cost and energy data included in Tables 4.4-14 and 4.4-15 for
controlling emissions from ethylene oxide plants in 1973.

           The possibility of NOX and CO formation and emission
from combustion equipment exists under certain operating condi-
tions.  If supplemental fuel contains sulfur, SOa emissions will
also result.

4.4.5     Phthalic Anhydride

          The production of phthalic anhydride by oxidation of
o-xylene is shown in the following chemical equation.
                                             + 3H20
In addition to this reaction there are side reactions which
produce COg and maleic anhydride.
                                206
-------
                TABLE 4.4-14.  ENERGY AND COST DATA FOR CONTROLLING VOLATILE ORGANIC
                               EMISSIONS FROM ETHYLENE OXIDE PRODUCTION (AIR OXIDATION)
                                                                  a,b,3i
Waste Stream
Control Technique
                                                         Energy Requirements
                                                  Fuel                  Electricity
                                                                                             Annualized
                                                                                             Cost  (1973)
Main process vent
15.3  in /a
(32,402 scfm)
Catalytic incinerator
                                              1.32 TJ/yr
                                              (1250xl06 Btu/yr)
                                                                        72 GJ/yr
                                                                        (20,000 kWh/yr)
                                                                       $3,400/yr
CO 2 rich purge
gas
0.226
        o
       in  /s
(480 scfm)
                     Catalytic incinerator    1.32 TJ/yr
                                              (1250x10* Btu/yr)
                                                   72  GJ/yr
                                                   (20,000 kWh/yr)
                                                                                            $4,000/yr
f90 Mg/yr (100.000 Tons/yr) production rate.
U1973 dollars.
°CostB are based on several assumptions.  See original reference.   Costs are based on 1973
 dollars and conditions.  Current costs may be significantly higher4
 Includes heat recovery credit.
-------
                  TABLE  4.4-15.  ENERGY AND COST DATA FOR CONTROLLING VOLATILE ORGANIC  EMISSIONS
                                FROM ETHYLENE OXIDE PRODUCTION (OXYGEN PROCESS)332
       Waste
       Stream
Flow
Rate
Control
Technique
      Energy Requirements               Annualized
Fuel	Electricity	Cost (1973)
       Main Pro-0.330m  IB  Steam boiler
       cess Vent   (699 scfm)
                                  3.96 TJ/yr
                                  (3750xl06 Btu/yr)
                                                72 GJ/yr
                                                (20,000 kWh/yr)     $5,900/yr
                0.331m  /s  Thermal incinerator    3.96 TJ/yr
                  (702 scfm)                         (3750xl06 Btu/yr)
                                                           36 GJ/yr
                                                           (10,000 kWh/yr)     $9,600/yr
       ^Production rate  90 Mg/yr  (100,000 tons/yr).
O      Costs are based  on 1973 dollars and conditions.  Current costs may be significantly higher.
00     clncludes heat recovery credit.
-------
          In the phthalic anhydride process,  liquid o-xylene is
vaporized and mixed with compressed, preheated air.  A small
amount of S02 is added to maintain catalyst activity.  The
mixture is fed to fixed-bed tubular reactors  containing vanadium
pentoxide catalyst.  Temperature is controlled with a circulat-
ing molten salt bath.  The effluent gases are cooled in switch
condensers where the phthalic anhydride condenses as a solid.
Condensers are heated to melt the crude phthalic anhydride which
is stored in a storage tank.  Vent gases from the condensers are
directed through a cyclone for removal of entrained solids.  The
collected solids are melted and added to the  storage tank.  The
remaining gas is usually scrubbed and may be  incinerated to re-
move residual organics before it is vented.  The crude phthalic
anhydride is pretreated to remove water and some low boiling
products.  The pretreated-,- crude phthalic anhydride is purified.,
by vacuum distillation before i't is stored in molten or solid
form. ..If solid product, is required, .a flaking-and bagging -opera-
tion is necessary.  Figure 4.4-5 is a simplified "flow sheet of
the process.

4.4.5.1   Emission Characteristics

          Average volatile organics emissions from phthalic
anhydride production are estimated as 0.0001 kg/kg (0.0001 Ib/lb)
product.  An.estimate of total organic emissions from phthalic
anhydride production is 45 Mg/yr (O.lx.106 lbs/yr).33  Emissions
may occur at the switch condenser vents in the pretreatroent
section, at the fractionation columns, and at storage tank vents.
The vent frou the switch condensers is usually controlled by
scrubbing and often by incineration.  A typical composition of
this vent stream before it is treated is given in Table 4.4-16.
Pretreatment and product fractionation are performed under
vacuum.  Noncondensibles and light ends are emitted in the exhausl
stream  from the vacuum jet ejector.
                              209
-------
                                        PROCESS
                                        VENT QAS
                                                    LIGHT ENDS
NJ
s
     AIR

O-XYLENE

    SO2
                        CATALYTIC
                        REACTORS
                              SWITCH
                          CONDENSERS
                                                  RESIDUE
PRETREATMENT
                                                                                       PHTHALIC
                                                                                       ANHYDRIDE
                                                                          BOTTOMS
                  FRACTIONATION
                     Figure 4.4-5.   Flow  diagram for production of  phthalic
                                     anhydride from o-xylene.
-------
      TABLE 4-4-16.
TYPICAL VENT GAS FROM SWITCH  CONDENSERS
  BEFORE TREATMENT3''*
Range in Average
Component Composition Average Flow Rate
(molJ)
Sulfur dioxide
Carbon monoxide
Carbon dioxide
Nitrogen
Oxygen
Phthalic anhydride
Maleic anhydride
Benzoic acid
Misc. hydrocarbons
Water
TOTAL
0.006-0.012
0.4-0.5
0.6-1.8
76-79
16.5-16.9

0.050-0.065

4.0-5.5

(kg/hr)

1
3
184
46




6
243
34
,094
,777
,957
,239
167
315
20

f*S5
,558
(Ib/hr)
75b
2,411
8,326
407,760
101,940
368
694
45 •.....-• '
.. • ..-• . ••
15,333" '..
536,952
  Upstream of pollution control equipment
  New catalyst value. Value varies with age of catalyst.

Xylene feed is stored in fixed  roof storage  tanks with atmospheric
vents.  Resulting emissions are estimated at 0.0001 k'.g/kg
(0.001 Ib/lb) product.as  Molten phthalic anhydride is stored
at 150°C (300°F)  and near stmospheric  pressure with a continuous
nitrogen purge.   The purge produces a  continuous gas stream which
is vented to the  air.

          A small quantity of emissions is produced in the flak-
ing and bagging exhaust (0.001  k.g/kg,  0.001  Ib/lb product) and
in the heat transfer system at  the switch condensers  (0.0002 kg/kgt
0.0002 Ib/lb product).38

           See Sections  4.6,  4.1,  and  4.15 for transportation emis
sions, fugitive emissions,, and  waste disposal emissions.
                                211
-------
 4.4.5.2   Control Technology

           The current practice in the industry is to control the
 vent gas from the switch condenser using a variety of equipment.
 One method of control is water scrubbing followed by incineration
 of the wastewater.  The system has an estimated volatile organic
 removal efficiency of about 96%.  A problem encountered is that
 the scrubbing solution is very corrosive due to the presence of
 maleic acid from absorbed maleic anhydride.37  Other methods for
 controlling the vent gas are a) water scrubbing followed by
 biological oxidation of the wastewater and b) direct thermal
 incinerat ion.

           Thermal incineration is employed by at least one plant
to control emissions from the condenser, vent.  Combustion of 90-
957o of the organics is estimated.38'89  Thermal incinerators com-
bined with waste heat boilers are also used.  977o destruction of
organics was measured in a test of this equipment combination. 1>c

           Catalytic incineration is practiced in some phthalic
anhydride plants which use naphthalene feed instead of o-xylene.
Catalyst life is shortened by fouling and poisoning, and.reported
catalytic combustion efficiencies are only 40-60 percent.1*1

           Combustion- in a steam boiler has not been applied as a
control method, although it could be .effective if the vent stream
is small compared to the total boiler requirement.  Flaring might
also be used for a control method on the condenser vent.  However,
efficiencies for removing contaminants are lower than for other
combustion methods.

           The effluent from the steam ejectors in the pretreat-
ment and fractionation areas may be controlled by the condenser
vent control equipment or it may be sent off-site for disposal

                               212
-------
(see Section 4.15).   At least one installation has a separate
incineration for ejector exhaust and by-product hydrocarbons
from fractionation.   Ninety-nine percent of the combustibles
are reportedly burned.1*2

          Storage tanks in phthalic anhydride plants are vented
directly to the atmosphere.  Some producers send portions of the
vented gas to incinerators.  At least one plant is equipped with
condensers from which phthalic anhydride is removed manually.
Recovery of phthalic anhydride in this manner amounts to about- -
0.0002 kg/kg- of product. (O..OOQ2 Ib/lb)..."3
4.4.5.3   Cost, Energy, and Environmental Impact of Controls

          General discussions of energy requirements, costs, and
environmental impacts of water, scrubbing, incineration, and con-
densation are located itt Section 3.  Some more specific cost and
energy data for control techniques for phthalic anhydride produc-
tion in 1973 are included in Table 4.4-17.

          Combustion devices have the potential for emissions of
NOX and CO.  If supplemental fuel contains sulfur, SOz emissions
will also result.  If water scrubbing is used as a control
method, a wastewater stream results which will require treat-
ment before its disposal.
                              213
-------
                TABLE 4.4-17.  ENERGY AND COST DATA FOR CONTROLLING VOLATILE ORGANIC
                               EMISSIONS FROM PHTHALIC ANHYDRIDE PRODUCTION3""
Waste Stream
Control Technique
          Energy Requirements
    Fuel	Electricity
                     Annualized
                     Cost (1973)
Vent gas from      Water scrubbing and
switch condensers  incineration
56.3  m3/s
(119,300 scfm)

                   Direct incineration
Waste products
2.63 Mg/hr
(5,792 Ib/hr)
Incineration and waste
heat boiler

Direct incineration
                           146.5 TJ/yr
                           (138,750xl06 Btu/yr)
523.4 TJ/yr
(495,750xl06 Btu/yr)

1.48 PJ/yr
(I,405,750xl06 Btu/yr)

33.8 TJ/yr
(32,000xl06 Btu/yr)
                          10.8 TJ/yr
                          (3xl06 kWh/yr)
                                                     7.13 TJ/yr
                                                     (1,980,000 kWh/yr)
0.36 TJ/yr
(100,000 kWh/yr)
$420,100/yr




$395,100/yr

$401,500/yr


$48,300/yr
 160 Gg/yr (130 MM Ib/yr) production rate.
 'costs are based on several assumptions.  See original reference.  Costs are
 based on 1973 dollars  and conditions.  Current costs may be significantly higher.
-------
4.4.6     Malelc Anhydride

          Maleic anhydride is produced by the catalytic oxida-
tion of benzene.  The reaction is shown in the following chemical
equation .

                          H       0
             ^     ,     X'— <
            (O)   + 7-02-1     t>  + 2HjO + 2CO:
                          H

Processing variations exist within the industry; however, the  ....
following process description is considered typical,*6   A. -mixture
of benzene and air is introduced into a reactor containing vana-
dium pentoxide and molybdenum catalyst. .Temperature control is
achieved through circulating heat transfer fluid or molten salt.
The reactor effluent is cooled before it passes through a par-
tial condenser and separator.  The overhead material is passed
through an absorber for recovery of the anhydride as maleic acid.
Maleic acid is generally  dehydrated by azeotropic distillation
with xylene .  Some producers use thermal  dehydration.  The re-
sulting anhydride is combined with maleic anhydride  from the
condenser.  Purification  is  accomplished by vacuum distillation.
The solid product is tableted or flaked before  packaging or
storage.  The product may also be shipped in bulk liquid form.
Figure 4.4-6  is  a simplified flow sheet of the  maleic  anhydride
process .

          There  are  alternative processes using butane and
butene feed.  They are used  by at least one U.S. producer and
are used in several  other countries.   They might become  more
significant .in the U.S.,  depending on the relative costs of  the
raw materials .   With the  exception of raw material storage and
some reactor  modifications,  the (\ system is about the same  as
the benzene process.
                              215
-------
BENZENE —I




    AIR	1
 N>
             CATALYTIC
             REACTOR
                                                     VENT
                                                                                                   VACUUM  VENT
                                                                    WATER
                                                            WATER AND CRUDE MALEIC ACID
SCRUBBER
                                                   CRUDE MALEIC ANHYDRIDE
                                                                                              XYLENE
                                                                                              STORAGE
                                                                                DEHYDRATION BY
                                                                                 DISTILLATION
                                        XYLENE
                                       9TBIPPER
                          CONDENSER    SEPARATOR
                                                              MALEIC
                                                             ANHYDRIDE
                                                                                                                RESIDUE
                                                                                                       VACUUM

                                                                                                      DISTILLATION
                                Figure 4.4-6.   Flow  diagram  for  production of maleic
                                                  anhydride from benzene.
-------
 4.4.6,1    Emiss ion  Characteris tics

           Estimated volatile  organic  emissions  from maleic
 anhydride  production are  0.088 kg/kg  product  (0.088 Ib/lb
 product),  including vented process  emissions,  fugitive emissions,
 and emissions from  the storage and  handling of raw materials   id
 product.*7  The estimates are based on uncontrolled emission
 sources.   .Two major sources are  vents from the product recovery
 scrubber and the vacuum system in the fractionation section.
 Estimated  average emissions from the  product  recovery scrubber
 vent are 0.086  kg/kg of product  (0.086 Ib/lb).*8  Benzene
 emissions  from  this vent  average 0.067 kg/kg  of product (0.067
 Ib/lb).*9  "During short term  process  upsets emissions may  be'3
 to 5 times greater.50 Other  organic  substances in the vent .gas
 stream include  maleic anhydride., maleic acid,  formaldehyde,
 formic add..and-.scyleire-.-5"1 •••-•"*''  " • •

           Maleic anhydride emissions,  are produced in  product
 handling operations such  as flaking,  pelleting, packaging, and    .
 storage.   Estimates from one  -plant  are emissions of 0.0002 kg
 maleic anhydride/kg product  (0.0002 Ib/lb),  Another  plant re-
 ported losses  of 0.3 kgfhr (0.6  Ib/hr) of maleic anhydride from
 the product storage area.52

 4.4.6.2   Control Technology

           Scrubbers are  used on the gas stream from the separator--
 to recover product.  Some plants also treat vent gases from '
 dehydration, fractionation, and storage tanks by scrubbing.
..Maleic acid removal efficiencies are quite high for scrubbing
 devices, but total hydrocarbon removal efficiencies are low.53
 Carbon adsorption and incineration are methods of  control employed
 in several existing facilities to remove the remaining organics
 from the vent gas stream.  Process modifications which increase

                               217
-------
feedstock utilization efficiencies may also be used to reduce
emissions.  Possible modifications include substitution of
oxygen for air, use of fluidization, use of more selective
catalysts, and use of recycle air.5"

4.4.6.3   Cost, Energy, and Environmental Impact of Controls

          Costs, energy requirements, and environmental impacts
for absorption, adsorption, and incineration are included in
Section 3.  The information is of a general nature.  More
specific information for maleic anhydride production was un-
available in the sources consulted for this study.

          Some general comments about potential environmental
impacts of control methods may be made.  Incineration has the
potential for emitting NOX and CO to the atmosphere.  However,
in the case of maleic anhydride, application of incineration
may reduce potential CO emissions because there is a high con-
centration of CO in the stream to be incinerated.  One company
reports greater than 95% reduction in CO by the use of an in-
cinerator. 5S   " .         .,...•

4.4.7     Vinyl Chloride Monomer by Balanced Process
          The balanced process for making vinyl chloride mono-
mer  (VCM) includes the manufacture of ethylene dichloride  (EDC)
as well as vinyl chloride.  Production of vinyl chloride by
cracking ethylene dichloride results in a hydrogen chloride
stream which is recycled to oxychlorination reactors for making
more ethylene dichloride.  Additional ethylene dichloride  is
made by direct chlorination of ethylene.  The production of
ethylene dichloride is balanced so that there is no net produc-
tion or consumption of HC1.
                              218
-------
          Figure 4.4-7 is a simplified process flow sheet show-
ing all three processes:  ethylene dichloride by direct chlorina-
tion, ethylene dichloride by oxychlorination, and vinyl chloride
production by cracking of ethylene dichloride.  Variations exist
in the industry, and Figure 4.4-7 represents a typical operation.

          The overall reaction involved in producing ethylene
dichloride by direct chlorination of ethylene is shown in the
following chemical equation.

          2CH2-CH2 + 2C12 *. ZCHaClCH^Cl

Ethylene and chlorine are .fed to a constant temperature reactor.
Temperature is controlled by vising jacketed vessels, cooling
coils, or external heat exchange.  The reactor effluent usually
consists.of a vapor stream.in .addition to a liquid stream. .The
vapor stream passes through a condenser and an absorber using
water or dilute caustic as a sorbent before it is vented.

          A parallel oxychlorination process produces ethylene
dichloride using by-product HC1  from the vinyl chloride plant.
The chemical reaction is shown in the following equation.

         . .2CH;z-CHa + 02 + 4HC1 + 2CH2C1CH2C1 + 2H20

Ethylene, hydrogen chloride, and air or oxygen are fed to a
reactor at 0.24-0.62 MPa (20-75  psig) and 222-333°C  (430-630°F).
The highly exothermic reaction requires efficient hi at removal
from  the reactor.  The reactor effluent is cooled by indirect
heat  exchange or by direct  contact with water and is then
treated in a phase separator.  Noncondensible gases  are con-
tacted with water and/or aromatic solvent before they are vented
to the atmosphere.  These operations reduce KC1 and  hydrocarbon
                              219
-------





10
N>
















trio
a a
m 7)
n
I*C
M
•





	 _-»»*»T1
M



JtT«
WIM
TM»««R





v*na





w








, 	 — LlOHf
HCI |
1 	 1 1 	 1 1 f~
WATW LMHTtNM j
Mr— r r
r^rr _JLJLJL

1 1 I | I PwmMof Towm v
i^.^ J L^^J 1 PHACTIQMATIOM
WAVT
•MM
e*U*TH> I tj

««ILT1«rAa< PMCTtOHATKNI





                                                                      INvi cmomoc
Figure 4.4-7.  Flow diagram  for production of ethylene dichloride
               and vinyl chloride monomer.
-------
emissions.  Some producers employ a direct chlorination step to
reduce the amount of ethylene lost in the vent gas.

          The organic liquid from the phase separator in the
oxychlorination process is combined with the organic liquid
from the direct chlorination process.  The combined streams may
be washed with caustic soda, or they may be sent directly to a
distillation unit for removal of water and chlorinated hydro-
carbon impurities.  Chlorinated hydrocarbon impurities are
sent off-site to disposal.  Some plants employ another distilla-
tion step to further purify the ethylene dichloride.  Other
plants have no product fractionation facilities in the ethylene
dichloride sections, however.  In these cases the impurities
may be rejected in downstream VCM facilities.56  The aqueous
phase collected in the phase separator is discharged as waste.
It may be treated in stripping columns for hydrocarbon removal
before it is sent to treatment or disposal.57

          Ethylene dichloride is cracked in the cracking furnace
at 480-510°C (900-950°F) and 0.45 MPa (50 psig).  The hot
effluent gases are quenched and partially condensed by direct
contact with ethylene dichloride.  Purification of vinyl
chloride monomer is accomplished in several fractionation
towers.  HCl is recycled to oxychlorination, recovered ethylene
dichloride is recycled to the process, and the  remainder of the
light and heavy ends are either further processed or disposed of.
Vinyl chloride product is usually caustic washed and sent to
product storage.58
                              221
-------
4.4.7.1   Emission Characteristics

          Qxychlorination Process^

          The estimated hydrocarbon emissions from the entire
oxychlorination process are 0.028 kg/kg (0.028 Ib/lb) EDC or
8.5 Gg/yr (18.8xlOfi Ibs/yr).59  These emissions are produced at
the main process vent from the phase separator (usually scrubbed
before venting), at product fractionation column vents, and at
str  .ge tank vents.  Catalyst conditioning may contribute addi-
tional hydrocarbon emissions.

          The vent gas from the oxychlorination process is us-
ually exhausted to the air from a scrubber or absorber.  This
vent gas is the primary hydrocarbon emission source in the
oxychlorination portion of the plant.  The average vinyl chloride
emissions were estimated to be 0.00036 kg/kg (0.00036 Ib/lb) of
ethylene dichloride produced.  This number represents an average
of emission numbers submitted by the industry.60  However, since
promulgation of the emission standards for vinyl chloride (41 FR
46560) in 1976, this emission factor has dropped.

          Small gas streams containing hydrocarbons result from
the fractionation  column vents.  All of the  fractionation vent
gases may be combined.  The uncontrolled vent stream  contains
about 0.010 kg volatile organics/kg EDC produced (0.010 Ib/lb).61
VCM is about five  percent of the volatile organics.62

          Because  the vapor pressure of ethylene dichloride  is
low, 21 kPa  (3 psi) at 38°C  (100°F), product storage  tanks are
normally vented to the atmosphere.63  Vapor  recovery  is practiced
to reduce emissions in some transfer operations for  filling
transportation equipment.  Normal storage capacity is  1.5 to 2
day production.6 **  Estimated EDC  losses from storage  tanks are
0.0006kg/kg EDC produced  (0.0006  Ib/lb).65

                              222
-------
          Direct Chlorination Process

          The direct chlorination process vent is the major
source of gaseous emissions from this area of the plant.  The
stream consists of inerts (0.018 kg/kg, 0.0181b/lb VCM), ethy-
lene (0.0025 kg/kg, 0.0025 Ib/lb VCM), ethylene dichloride
(0.0016 kg/kg, 0.0016 Ib/lb VCM), and small amounts of vinyl
chloride.66  The fractionation emissions are included in the
oxychlorination section above.

          Vinyl Chloride Process

          The fractionation area of the vinyl chloride production
process is the largest source of organic emissions from this area
of the plant.67  Estimates of organic emissions from an uncon-
trolled fractionation vent include 0.0021 kg hydrocarbons plus
0.0024 kg VCM per kg VCM product (0.0021 Ib and 0.0024  Ib,
respectively, per Ib product).88  Hydrocarbon emissions from the
quench tower are estimated at 0.00005 kg/kg (0.00005 Ib/lb)
product.  Storage and fugitive losses are estimated to be
0.0001 kg hydrocarbons/kg VCM by 'one information source (0.0001
Ib/lb.) .v'.9  Another-source in-dicates that fugitive'  losses of VCM
amount to 0'.0,012 kg/kg (0.JO'012 Ib/lb) 'VCM product..7l5" These
emission factor estimates were made before promulgation of the
emission standards, for vinyl chloride; therefore,  current emission
factors will be significantly lower.

4.4.7.2   Control Technology

          Oxychlorination Process

          There are  several methods  currently used in oxychlori-
nation facilities for control of emissions from the rnain process
vent.  Absorption is used on at least one installation  to recover
                              223
-------
EDC.  The amount of EDC recovered using this method is 0.02 kg
EDC/kg EDC product (0.02 lb/lb). 7J  Condensation by refrigera-
tion of the vent gas stream to -6 C°(21°F) is practiced in another
facility.72  Organic emissions after the refrigeration step are
0.015 kg/kg EDC (0.015 lb/lb).73  Some producers using aromatic sol-
vent absorber-stripper systems for product recovery use mist eli-
minators to prevent liquid carryover.  Estimated solvent recovery
for these systems is 0.010 kg solvent/kg EDC produced (0.010 lb/
lb).7"  Some losses of the aromatic solvent occur  (0.0009 fcg/kg
VCM)(0.0009 lb/lb), but total volatile organic emissions are low-
ered to 0.012 k.g/kg (VCM (0.012 lb/lb).75  Another method  currently
used for reducing ethylene emissions in the vent gas is direct
chlorination.  Data indicate that hydrocarbon emissions in the vent
stream are reduced by about 50 percent when direct chlorination is
employed.

           Combustion devices  reduce or eliminate  volatile organic
  emissions from the process vent.   Combustion of chlorinated hydro-
  carbons results  in formation  of  HC1,  Clz,  and toxic gases, which
  cannot be vented to the atmosphere.   However, these substances
  may be removed by scrubbing.  Scrubbing  equipment in contact with
  solutions of  these substances may  suffer severe corrosion.   Com-
  bustion devices  (boilers and  thermal  incinerators) would  have to
  employ scrubbers for removal  of  HC1 and  Cla from  the effluent
  gases.  For this reason flaring  could not be used.   Indications
  are  that  several companies  are now using incinerators.

             The  product fractionation vents in  EDC plants are
  currently controlled in  some plants by refrigeration.   Refrigera-
  tion  removes  about 85% of  the hydrocarbons contained in the gas.76
  Gas  cooling techniques are  also applicable to  the vent streams
  from absorber lean oil stripping,  wastewater stripping, and EDC
  caustic scrubbing, but they are not widely used.   One facility
                              224
-------
has a refrigeration control device on a vent stream from waste-
water stripping.  It removes about 707, of the hydrocarbons
contained in the gas."  Hydrocarbon emissions from wastewater
stripping without refrigeration are about 0.002 Kg/kg EDC pro-
duced (0.002 lb/lb).*e  Combustion devices could be ustd lor
elimination of hydrocarbon emissions from sources controlled by
refrigeration, but the resulting HC1 would be emitted to the
atmosphere. .Using a combustion device downstream from a gas
cooling operation would result in a lower HC1 concentration in
the gas, but it would probably not be low enough to exhaust the
gas to the atmosphere.

          Control devices available for the fixed roof storage
tanks .containing purified EDC product include floating roof
tanks and vent condenser.  Vent condensers are currently used
in some locations.  Emissions from crude EDC storage are con-
trolled by the layer of water blanketing the organic material.79,

          Direct Chlorination Process

          Vent gas from the direct chlorittation plant is usually
condensed and scrubbed before it is vented.  It could be sent to
the control device provided for'the oxychlorination plant.

          Vinyl Chloride Process

          The vents from fractionation in the VCM plant may be
controlled in several ways.  One VCM producer uses EDC to absorb
VCM vapors before the gas is vented.  Stripping removes VCM,
and the EDC is recycled to the pyrolysis units.  VCM recovery is
estimated at 99%.80  Another company uses a waste heat boiler
to burn hydrocarbons and chlorocarbons, including VCM.  It is
operated with two parallel caustic scrubbers upstream and a
water scrubber downstream to collect chlorine and HCl.  VCH
                               225
-------
levels were reduced by 98-997« in a test run.  Another possible
control method is compression and refrigeration to condense VCM
before venting the inerts.  It is estimated that this operation
would recover 877o of the VCM in the gas stream.  Another possi-
bility is carbon adsorption.  It is estimated that under optimum
conditions 99.97o recovery of VCM and EDC could be achieved using
a carbon adsorption system.81

           Refrigeration is used by some producers to recover
losses of VCM from storage and loading operation vents.  One
producer reports using -23°C (-10°F) temperatures to recover
0.0001 kg/kg VCM (0.0001 Ib/lb) in this manner.  Another refrigera-
tion process operated at 4°C (40°F) recovers about 857. of the VCM
in the stream before venting the gas.82  See Sections 4.5, 4.6,
and 4.1 for storage, loading, and fugitive emissions controls.

4.4.7.3    Cost, Energy, and Environmental Impact of Controls

           Costs, energy requirements, and environmental impacts
of absorption, condensation, and incineration are discussed gen-
erally in Section 3.0.  Fugitive emissions and  storage tank
losses are treated in Sections 4.5 and 4.1.  Some costs and energy
requirements for control methods in a balanced  vinyl chloride
plant are also included here in Table 4.4-18.

           In combustion of vent gas  streams in a vinyl chloride
plant provision must be made to remove the HCl, C12 and other
chlorine compounds formed.  The combustion process also has the
potential for forming NOX and CO. Carbon adsorption systems have
an associated solid waste problem if  the beds are not regenerated.
If the beds are regenerated at high temperatures, atmospheric
emissions may result.
                               226
-------
        TABLE  4.4-18.  ENERGY AND COST DATA FOR CONTROL OF VOLATILE ORGANIC EMISSIONS FROM
                       PRODUCTION OF VINYL CHLORIDE MONOMER BY, THE BALANCED PROCESS,3' "3
Waste Stream
Oxychlorination
vent
EDC fractiona-
tion
VCM fractiona-
tion
Energy Requirements
Control Technique Fuel Power
Incinerator and waste 14GJ - 30GJ/hr 0.36 GJ/hr
heat boiler with:caus- (14-28xl06 Bt«/hr)d (100 kWh/hr)
tic scrubbers ;
Waste heat boiler with 2 GJ/hr 0.16
caustic scrubbers (2xl06 Btu/hr) (45
Refrigeration .
0.14
(40
Waste heat boiler with 2 GJ/hr 0.16
caustic scrubbers (2xl06 Btu/hr) ' "> ' (45
Storage and
loading
Fugitive losses


Compression and re-
frigeration
Continuous loop
sampler
Canned pumps : '
Monitoring of VCM leaks
0.14
(40
' . •
GJ/hr
kWh/hr)
GJ/hr
kWh/hr)
GJ/hr
kWh/hr)
GJ/hr
kWh/hr)

Utility requirements insignificant
'•: ' .

Annual I zed
Costb»c
$1,140,000
$300,000
$200,000
$300,000
$200,000
$ 50,000
$200,000
$200,000
f*700 x 10 Ib/yr product ion rate .
January, 1975 dollars, capital costs.
.Costs are based on several assumptions. See original reference.
33,800 Ib steam generated/hr (245 psig)
-------

ACM • VENT
CUMINt RECYCLE VINT | RECYCLE
1 P AdO "A|™
r.uMtiif --r r , .1 '. .. . *• — I
*,n . r eu-tNi j


1
•AtTCWATCH
IS OXIDATON "ICOVtHY CUAVAM „»»„„„, »*•>«
fJsACTCm OIVKSl REACTOR WPARATOR Towtl|
V



t















t









'







— *















1 —



r* r"


                                                                    ». CUUCNE
                                                                      (RECYCLED)
                                                                    ». « -METHYL
                                                                      STYRENE
                                                                     RESIDUAL OIL
                                               MULTItTASE FHACTIOHATION
Figure 4.4-8.  Flow diagram  for the production  of acetone
                 and phenol from cumene.
-------
4.4.8     Acetone and Phenol from Cumene

          There are two steps involved in producing acetone and
phenol from cumene.  The first step is production of cuniene
hydroperoxide by oxidation.   The second step is cleavage of
cumene hydroperoxide to form acetone and phenol.   The chemical
reactions are shown in the following equations.  ct-methyl
styrene and acetophenone are formed as by-products.
Figure 4.4-8 is a simplified process flow sheet of the process.

          Air, sodium carbonate, and cumene are agitated in the
reactor to produce cumene hydroperoxide.  Catalysts and emulsi-
fiers may also be used.  Reactor gases are vented through refrig-
eration systems and other equipment for recovery of cumene.

          Cumene hydroperoxide  formed  in the oxidation step is
contacted with sulfuric  acid in the cleavage step to produce
acetone and phenol.  The organic layer is washed with water
before it is  fractionated in a  series  of distillation towers.
Cumene is recovered and  recycled;  a-methyl  styrene  is hydro-
genated and recycled or  may be  recovered as product; and phenol
and  acetone are stored.  The by-product, acetophenone, may be
purified, or  it may be left with the residual  oil.
                              229
-------
4.4.8.1    Emission Characteristics

           The largest single source of emissions in the produc-
tion of phenol and acetone from cumene is the vent from the oxi-
dation reactor.  Emissions are significant even though recovery
devices are an integral part of the equipment.  Volatile organic
emissions reported from this source vary from trace amounts to
0.0067 kg/kg phenol produced (0.0067 Ib/lb).8"  Equipment failures
have reportedly caused 1-4 hr emission rates of 0.049 kg/kg
phenol (49 lb/1000 lb).8S  A summary estimate of average emissions
from acetone and phenol plants is 0.0038 kg hydrocarbons/kg
phenol product from this vent gas (0.0038 Ib/lb).86

           Some producers have concentrators on the vent gas
stream.  The concentrator vents have low emission levels of
0.0003 Kg/kg phenol (0.0003 Ib/lb) or less.  The cleavage reactor
vent also contributes "low to moderate" light organics emissions.87
The emissions in the concentration and cleavage reactor section
are estimated to be 0.0021 k.g/kg phenol product  (0.0021 Ib/lb). as
                                     *
           Volatile organics are also emitted in the fractiona-
tion section at the distillation columns.  The major organic
emission is acetone.  Formaldehyde may also be emitted as may
trace amounts of cumene, mesityl oxide; a-methyl styrene, and
phenol.  An average estimate of hydrocarbon emissions from this
section of the plant is 0.0038 kg/kg phenol  (0.0038 Ib/lb).89
One producer estimates 0.0043 kg acetone  and" 0.003 kg formaldehyde/
kg phenol product  (0.0043 and 0.003 Ib, respectively, per Ib
product).  Another estimates 0.0012 kg acetone and 0.0009 kg
formaldehyde/kg phenol  (O.Q012 Ib  and 0.0009  Ib, respectively,
per Ib product).90  It is emphasized that the above emissions
estimates are  several years old.   Current emissions are  thought
to be  lower for most plants.
                               230
-------
           Storage tanks for raw materials and products also are
emission sources.  Other volatile organic emissions have been
reported during equipment failure, start ups,  and plant emer-
gencies.  Sources of fugitive emissions are valve packings,
flanges, pump seals, compressor seals, relief valves, and agi-
tator seals.

4.4.8.2    Control Technology

           Carbon adsorption is used in several plants to recover
cumene  from the oxidation reactor vent with reported specific
efficiencies of 82-917».91 Recently, one company indicated an
efficiency ranging from 95-99% for their carbon adsorption
system.92  Refrigerated condensation also is used in several
facilities to recover .cumene from .the oxidizer off-gas.93  Although
the.'specif ic-'purpose of-the adsorption and refrigeration systems
is product recovery, use of the systems reduces emissions.  An
incinerator is used in at least one installation to eliminate
emissions from the oxidizer vent, gas,,- Another facility sends
light waste to plant boilers for use as fuel.9"  'Emissions are
reportedly controlled.from the cleavage reactor and the fraction-
ation area of one plant by cold water"condensers and knock out
drums.95  Many producers have floating roof tanks, Nz  blankets,
or other  conservation devices on  storage  tanks.  Floating  roof
and vapor seal devices have virtually eliminated emissions  from
s-torage in one plant.96  See Sections 4.1 and 4.5 for  fugitive
and storage emis-sions and control.

4.4.8.3    Cost, Energy, and Environmental  Impact of  Controls

            Costs, energy requirements, and  environmental
impacts for adsorption,  condensation, and incineration are., covered'•
in a generalized manner  in Section  3.0.   Specific  data for con-
trolling  vo-1-atile organic emissions from  phenol  and  acetone
                               231
-------
  production were not  available  in  the  sources  consulted  for this
  study.

            Some general comments  can  be made  about  environmental
  impact  of control methods.   Incineration has  the  potential for
  emitting NOX and  CO  to the  atmosphere.  Carbon  adsorption has the
  potential for creating a solid waste  problem  if the beds are not
  regenerated.  Atmospheric emissions may result  if the beds are
  regenerated  at high  temperatures.

  4.4.9     Beferences

  1.   Synthetic Organic Chemicals,  United States  Production  and
      Sales, 1974.  U.S. International Trade  Commission, Washington,
      B.C.  TC Publication 776.

  2.   Top 50 Chemicals:  Only a  handful1 fail to  join the trend
      upward.   Chemical and Engineering News.  June 6, 1977.
      p.  42.

  3.   Horn and T.W. Hughes.  .Source Assessment:  Acrylonitrile
      Manufacture  (Air Emissions) .   Monsanto Research Corp.
      Dayton,  Ohio.  Prepared for EPA,  Contract No. 68-02-1874.
      Preliminary  report, March  1977.

4-7.   Schwartz, et  al.  Engineering and Cost Study of Air Pollution
      Control  for  the Petrochemical Industry, Vol 2:   Acrylonitrile
      Manufacture.   Houdry Division, Air Products and Chemicals.
      EPA-450/3-73-006b.  February 1975.  103 p.

  8.   Reference 3.

  9.   Reference 4.
                                232
-------
   10.   Morris,  R.  B. ,  et al.   Engineering  and  Cost  Study of Air
        Pollution  Control for  the  Petrochemical  Industry, Vol 4:
        Formaldehyde Manufacture with  the Silver Catalyst Process.
        Houdry Division,  Air Products  and Chemicals.   EPA-450/
        3-73-006d.   March 1975.  94  p.

   11.   Morris,  R.  B. ,  et al.   Engineering  and  Cost  Study of Air
        Pollution  Control for  the  Petrochemical Industry, Vol  5:
        Formaldehyde Manufacture with  the Mixed Oxide Catalyst
        Process.  Houdry Division, Air Products and  Chemicals.
        EPA-450/3-73-006-e.  March 1975.   82 p.

12-16.   Reference  10.

17-22.   Reference  11.

23-32.   Field, D.  E., et al.  Engineering and Cost Study of Air
        Pollution  Control for the  Petrochemical Industry, Vol  6:
        Ethylene Oxide Manufacture by Direct Oxidation of Ethylene.
        Houdry Division, Air Products  and Chemicals.  EPA-450/
        3-73-006f.  June 1975,  97 p.

33-38.   Schwartz,  W. A., et al.  Engineering and Cost Study of Air
        Pollution Control for the Petrochemical Industry, Vol  7:
        Phthalic Anhydride Manufacture from Ortho-Xylene.   Houdry
        Division,  Air Products and Chemicals.  EPA-450/ 3- 73-006 g.
        July 1975.  108 p.
   39.  Danielson, J. A. (ed.).  Air Pollution Engineering
        Air Pollution Control District County of Los AnfteleB.  U.K
        Department of Health, Education and Welfare.  1967.  As
        cited in Reference 33.
                                  2.33
-------
   40.   Reference 33.

   41.   Fawcett,  R.  L.,  Air Pollution Potential  of Phthalic
        Anhydride Manufacture.   Journal  of the Air Pollution
        Association 20:   461-465.   July  1970.  As  cited in Refer-
        ence 33.

42-45.   Reference 33.

   46.   Pervier,  J.  W.,  et al.   Survey Reports on  Atmospheric
        Emissions from the Petrochemical Industry, Vol. III.   Houdry
        Division, air Products  and Chemicals.  EPA-450/3-73-005 c.
        PB-245629.  April 1974.  pp.  19-38.

47-50.   Emission Control Options for the Synthetic Organic  Chemicals
        Manufacturing Industry - Maleic Anhydride  Product Report.
        Hydroscience,  Inc.  Prepared for EPA,  Contract No.  68-02-2577.
        March 1978.

51-54.   Reference 46.

   55.   Pruessner, R.  D. and L. D. Broz.  Hydrocarbon Emission
        Reduction Systems, Chemical Engineering Progress 72 (8)
        69-73.  August 1977.     ,        -

56-57.  Schwartz, W. A., et al.  Engineering and  Cost Study of Air
        Pollution Control for  the Petrochemical Industry.  Vol. 3:
        Ethylene Bichloride Manufacture by Oxychlorination.
        EPA-450/3-73-006c.  PB-240492.  November  1974.  94 p.

   58.  Bellamy, R. G. and W.  A. Schwartz.  Engineering and Cost
        Study of Air Pollution Control for the Petrochemical
        Industry, Vol. 8:  Vinyl Chloride Manufacture by the
        Balanced Process.  EPA-450/3-73-OC6-h.  July 1975.   61 p.
                                  234
-------
   59,   Reference 56.

   60.   Standard Support  and Environmental  Impact  Statement:
        Emission Standard for Vinyl  Chloride.   Environmental  Pro-
        tection Agency.   Research Triangle  Park, NC.   EPA-45Q/2-75-
        009.   October 1975.   536 p.   Table  4-10.

   61.   Reference 56.

   62.   Reference 56 as  cited in Standard Support  and Environmentsi
        Impact Statement:  Emission  Standard for Vinyl Chloride.

63-65.   Reference 56.

   66.   Reference 58.

   67.   Pervier, J. W. ,  et al*;  Survey Reports on  Atmospheric
        Emissions froa the Petrochemical Industry, Vol.  IV.   Houdry
        Division, Air Products and Chemicals.   EPA-45Q/3-73-OQ5d.
        PB245630.  April  1974.  pp.  187-214.

   68.   Reference 58, TableVC-9.

   69.   Reference 56.  -•

   70.   Reference 56 as cited in Standard Support  and Environmental
        Impact Statement:  Emission Standard for Vinyl Chloride.

71-74.   Reference 56.

   75.   Reference 58.

76-79.   Reference 56.
                                   235
-------
80-83.  Reference 58.

84-91.  Pervier, J. W., et al.  Sxnryey Eeports on Atmospheric
        Emissions from the Petrochemical Industry, Vol. III.  Houdry
        Division, Air Products and Chemicals.  EPA-450/3-73-005 c.
        PB245629.  April 1974.  pp. 103-146.

   92.  Letter with attachments from W. M. Reiter, Allied Chemical
        Corporation to Mr. D. A. Beck, EPA, February 21, 1978.

93-96.  Reference 84.
                                   236
-------
4.5       Storage Tanks

          The petroleum and chemical process industries include
many operations.  Petroleum production, refining, chemical manu-
facturing, transportation, marketing, and consumption all require
some type of storage for volatile organic liquids.  Storage
tanks for volatile organic liquids can be sources of evaporative
emissions.  This section discusses the types of storage tanks,
the sources and quantities of emissions from each type, costs
of various types of tanks, and the major control techniques
available.

          Two recent studies on storage tank emissions indicate
that emission factors in this section may be high by 507» or more.-
However, the studies are not comprehensive enough to generate
revised emission factors.  API is conducting a more comprehensive
study of emission losses in floating roof and fixed roof tanks.
Completion of test programs and publication of revised emission
factors are expected in early 1979.

          A new source performance standard has been promulgated in
40 CFR Part 60  Subpart K, Standards  of Performance for Storage
Vessels for Petroleum Liquids.  These standards generally apply
only to refineries and refinery-type products and are not gener-
ally applicable to chemical plants.  Three categories of volatil-
ity are low, intermediate, and high.  Table 4.5-1 defines
volatility in terms of vapor pressure and lists the types of
storage tanks acceptable for liquids in each range of volatility.
Five types of storage tanks are listed in Table 4.5-1.

          The following sections describe each type of storage
tank, emissions from ^.he tanks, and  control techniques.  Fixed
roof storage tanks for low volatility liquids are described in
Section 4.5.1.  Several tanks for storage of intermediate
                              237
-------
       TABLE 4.5-1.  STORAGE  TANKS WHICH PROVIDE ACCEPTABLE LEVELS OF ORGANIC VAPOR EMISSION
                            CONTROL DEPENDING  ON VOLATILITY  OF LIQUID STORED
        Volatility of
        Stored Liquid
                               Vapor   Pressure
                               	Range 	
  kPa
Metric
  psia
Type of Storage Tank Required  for
   Acceptable Levels of Control
        low
                                       fixed cone  roof tank
.to
oo
        intermediate
10-79
1.5-11.2
   floating roof tank
   covered floating roof tank
   variable vapor space tank  (lifter
     roof and flexible diaphragm) with
    vapor controls for loading losses
        high
>77
                       pressure'tanks  sealed or vented  to
                       recovery systems

                          a.  low pressure  2.5-15 psig
                          b,  intermediate pressure
                              15-30 psig
                          c.  high pressure  >30 psig
        Minimum acceptable standard under NSPS
-------
volatility liquids are described in Section 4.5.2.  Pressure
tanks for high volatility liquids are discussed in Section
4.5.3.  Table 4.5-2 gives emission factors for evaporation from
storage tanks for low and intermediate volatility liquids.
Table 4.5-3 is an inventory of storage tanks and their emissions.
Section 4.5.4 contains a discussion of cost, energy, and environ-
mental considerations of controlling emissions from storage
tanks.

4".5.1     Fixed Roof Storage Tanks for Low Volatility Liquids

          Use of "fixed cone" roof tanks is the minimum accepted standar
for storage of low..volatility liquids,  Construction costs font
fixed cone roof tanks are lower than costs for other storage -
tanks.-  As shown in Figure 4.5-1, fixed roof tanks consist of
a cylindrical steel shell topped by a coned roof having a mini-
mum slope of 3/4 inches in 12 inches.  The tanks are generally
equipped with a pressure/vacuum vent designed to contain minor
vapor volume changes.  The.recommended maximum operating pressure/
vacuum for large fixed cone roof tanks is +207 Pa/-207 Pa
(+0.8 in H20/-0.8 in H20).3

4.5.1.1   Emissions

          As shown in Table 4.5-3, fixed roof tanks are responsible
for 80% of the total volatile organic emissions from storage tanks-,
The  two major  sources of  emissions  from  fixed cone  roof
tanks are breathing  losses and working losses.  Breathing
losses occur during  changes  in  temperature  or barometric
pressure.  Working losses occur  as a  result  of  filling
or emptying operations.   Filling loss is  the result of vapor
displacement by  the  input of  liquid.  Emptying  loss is  the  expul-
sion  of vapors after product  withdrawal  and  is  attributable  to
                               239
-------
                TABLE  4.5-2
EVAPORATIVE EMISSION FACTORS FOR FIXED ROOF. FLOATING

ROOF AND VARIABLE VAPOR SPACE STORAGE TANKS1
to
jf
o

Vapor Pressure t 16°C(P»)
60°F(p9ls)
FIXED ROOF TANKS
Breathing Loaa
Mew Tank Conditions
Ib/day - 10' gal
Kg/day - 10 ' llt«ra
Old Tank Conditions
Ub/day - 10* gal
Kg/day - 10* liters
Working Loss
lb/101 gal throughput
Kg/ 10* liter throughput
FLOATING ROOF TAMKS
Standing Storage Loss
Mew Tank Conditions
Ib/day - 10* gal
Kg/day - 10* liters
Old Tank Conditions
Ib/day - 10* gal
Kg/day - 10* liter* .
Withdrawal Losses
lb/10' gal throughput
Kg/101 liter throughput
VARIABLE VAPOR SPACE TAHKS
Filling Loss
lb/109 gal throughput
Kg/ 10' liter throughput
Fuel
No. 6
0.3
4. 3x10" *



.00014
.000017

.00016
.000020

.00018
.000022



.000014
.0000017

.000034
.0000041

MA
HA


.00017
.00002
Oils
W>2
7. 4x10" '



.0034
.00041

.0038
.00046

.023
.0028



.00039
.000046

.00089
.000111

NA
NA


0.022
0.0026
Jet Fuels
Kerosene
59
8.6x10 '



.0037
.00045

.0042
.00051

.027
.0032



.00043
.000051

.0010
.00012

HA
HA


0.025
0.0030
Naphtha
9,000



0.074
0.0087

0.085
0.0098

2.5
0.3



0.0094
0,0011

0.022
0.0027

NA
NA


2.3
0.28
Crude
Oil
19,000
2.75



0.055
0.0066

0,063
0.0075
•
2.8
0.34



0.0099
.0.0012

0.023
0.0028

NA
NA


2.3
0.28
Motor Gaaollne
RVP 7
24,000



0.14
0.017

0.16
0.019

5.7
0.68



0.018
0.0022

0.043
0.0052

0.018
0.0022


5.4
0.65
RVF 10
36,000
5.2



0.20
0.024

0.23
0.027

8.2
0.99



0.026
0.0032

0.061
0.0074

0.018
0.0022


7.7
0.93
RVP 13
48,000
7.0



0.26
0.031

0.30
0.036

10
1.2



0.035
0.0041

0.079
0.0094

0.018
0.0022


9.6
1.2
-------
               TABLE 4.5-3.   PETROLEUM STORAGE TANK INVENTORY AND EMISSIONS
                                                                                 a,b,
Vapor Pressure Range
kiloPascals
fpsia)
10.5 to 35.5
(1.52 to 5.14)
35.5 to 62.7
(5.14 to 9.08)
62.7 to 76.5
(9.08 to 11.1)
TOTAL

Fixed Roof
Emissions
Tanks Gg/yr
(1000 tons/yr)
5,840 406
(447)
1,396 135
(149)
49 16
(18)
7,285 557.
(613)
Floating & Internal
Floating Roof
Tanks
7,093

3,357

218

10,668

Emissions
Gg/yr
(1000 tons/yr)
64
(70)
61
(67)
9
(9.9)
'; 134 .
(147)
TOTAL
Emissions
Tanks Gg/yr
(1000 tons/yr)
12,933 470
(517)
4,753 196
(216)
267 25
(28)
17,953 691
(870) •
.Includes only tanks with greater than 150,000  liter capacity.
'calculated from AP-42, Supplement 7, April,  1977.
-------
NOZZLE
                  PRESSURE-VACUUM
                  VENT
                                              GAUGE HATCH
                     Figure  4.5-1.  Fixed roof storage tank.
                                       242
-------
 "vapor growth".*  After product withdrawal,  air enters the
tank to fill the volume previously occupied by product.  The
stored liquid not withdrawn evaporates' to the point of satura-
tion in air.  This process is called "vapor growth".

          Factors affecting the rate of volatile organic loss
from fixed roof storage tanks include:

          1.  True vapor pressure of the liquid stored

          2,  Temperature changes in the tank (primarily
              induced by diurnal ambient temperature changes)

          3.  Height of the vapor space (tank outage)

          4.  Tank diameter

          5.  Schedule of tank filling and emptying

          6.  Mechanical condition of tank and p/v valve
              seals        '

          7.  Tank design 'and type of exterior paint.

          The American Petroleum Institute has developed emperi-
cal formulas, based on field testing, that correlate fixed cone
roof tank evaporative losses with the above factors and other
specific storage parameters.   These equations and their applica-
tion are presented in Supplement No. 7 of EPA document AP-42,
Compilation of Air Pollution Emission Factors.  The factors  in
AP-42 and the API bulletins are being revised.  The equations
are best suited for estimating average emissions for a
group of tanks, and should be used with
                              243
-------
discretion for any specific tank.  Emission rates calculated
from these equations for some "typical" storage tank conditions
are presented Table 4.5-2.

4.5.1.2   Control Technology

          There are several ways to control emissions from stor-
age 'of low volatility liquids.  The first approach, applicable
primarily to new construction, is to install storage tanks with
Ipwer loss rates than fixed cone roof tanks.  Tanks with lower
loss rates include floating roof tanks, internal floating covers,
and variable vapor space tanks equipped with vapor recovery
systems.  These lower loss tanks are generally used for inter-
mediate volatility liquids and are discussed in Section 4.5.2.
The control efficiency of lower loss -storage tanks is approxi-
mately 90 to 95 percent.5

          A second approach to controlling evaporation losses
from fixed roof storage tanks includes retrofit control technol-
ogy such as internal floating roofs and vapor recovery systems.
Internal floating roofs are large pans or decks which float
freely on the surface of the stored liquid  (Figure 4.5-2).  The
roof rises and falls according to the depth of the stored
liquid.  To insure that the liquid surface Is completely covered,
the roof is equipped with a sliding seal around its periphery
which fits against the tank wall.  Seals have also been developed
for use where support columns must pass through the floating
roof or cover.  Internal floating roofs can generally be installed
inside existing fixed roof tanks if they are of welded construc-
tion.  However, if they are of bolted construction, they cannot
be retrofitted.
                              244
-------
          Vapor recovery systems can also be installed on
existing fixed cone roof tanks.   Figure 4.5-3 is a flow diagram
for a simplified vapor recovery system.  Vapor recovery systems
for tank farms, terminals,  etc.  are more complex than the
example shown here.  Vapors generated in the fixed roof tank are
displaced through a piping system to a storage tank called a
vapor saver.  The vapor saver evens out surge flows and saves
a reserve of vapors to return to the storage tank during in-
breathing modes.  Inbreathing saturated vapors instead of air
prevents the evaporation of additional volatile organics.
Several storage tanks can be manifolded into a single vapor
saver and vapor recovery system.  Vapor recovery systems are
not usually as cost effective as internal floating roofs, par-  ...
ticularly for tanks with high filling rates.  They have not be-efc"
widely used ..on-large tanks and tank farms.  The control ef f i- •''
ciency of vapor recovery systems for fixed cone roofed tanks-
is approximately 90 to 98 percent.6

          A third control technology, the use of conservation
vents, is adequate only for low volatility product storage (less
than 10.5 kPa, 1.52 psia).   A conservation vent is a pressure
and vacuum relief valve which vents only when a set pressure
differential is exceeded.

4.5.2     Storage Tanks for Intermediate Volatility Liquids

          Intermediate volatility liquids are generally stored
in floating roof tanks, internal floating roof tanks, variable
vapor space tanks with vapor recovery systems, and/or fixed
roof tanks with vapor recovery systems.  Although simple fixed
roof tanks have been used for intermediate volatility liquid
storage in the past, new source performance standards do not
allow this practice.
                              245
-------
                                    (MR VENTILATORS
NOZIIE
      Figure 4.5-2.   Covered floating roof storage tank.
_JL!
prTTj
h.
STORED
L1QLOD


VAPOR WMNQ I VAPOR
••• 	 "•• 	 • 	 " 	 — 	 "••• 	 SAVER
VENT
•n-

SYSTEM j
      Figure 4.5-3,
Example of  simplified tankage vapor
recovery system.
                                                         c»-teee-i
                         246
-------
             Float Ingt_ Itopf :iTanks_

             Floating roof tanks reduce evaporative storage losses
   by minimizing vapor spaces.   The tank consists of a welded or
   riveted cylindrical steel wall equipped with a deck or roof
   which is free to float on the surface of the stored liquid.
   The roof rises and falls according to the depth of stored liquid.
   To insure that the liquid surface is completely covered, the roof
   is equipped with a sliding seal which fits against the tank wall.
   Sliding seals are also provided at support columns and at all
   other points where tank appurtenances pass through the floating
   roof.       .  -         ...     .  '

             The most commonly used floating roof tank is  the
   conventional open tank.  The open tank roof deck  is exposed; to
   the  weather, and provisions must be made for rain water'drain-
   age, snow removal, and sliding  seal dirt protection.  Floating
   roof decks  are  of three general types:  pontoon,  pan, and  double
   deck.

             The pontoon roof,  shown in Figure 4.5-4,  is a pan-
   type floating roof with pontoon sections added to the top  of
   the  deck around the rim.  The pontoons are arranged to  provide
   floating stability under heavy  loads of water and snow.

             The pan roof shown in Figure 4.5-5  is a flat  metal
• •' ""pi-ate with  a vertical rim and  stiffening braces to maintain _,.->
  • ri-gidity.   The  single metal  plate roof in contact with  the
   liquid  readily  conducts  solar heat,  resulting  in  higher
   vaporization  losses than other  floating roof  decks.  The roof  is
   equipped with automatic vents  for pressure and vacuum release.

             As  shown  in  Figure 4.5-6,  the double deck-roof has
   a hollow double deck  covering the entire  surface  of the roof.
                                 247
-------
          ROOT SEM.
         . INON-METALUC)
NOZZLE
  Figure  4.5-4,
Single deck pontoon floating roof storage
tank with  non-metallic seals.
                            248
-------
             /HOOP SB* 1. IMCTftLUC SMO«
NOZZLE
      Figure 4.5-?5.
                Pan-type, floating roof storage tank
                with metallic  seals.
             BOOT SEAL
   NOZZLE
Figure 4.5-6.
                      Double  deck floating  roof storage tank
                      with non-metallic seals.
                                249
                                                                 Ot-1670-4
-------
The double deck adds rigidity, and the dead air space between
the upper and lower deck provides significant insulation from
solar heating.7

          Covered Floating Roof Tanks

          The covered-type floating roof tank is essentially
a fixed roof tank with a floating roof deck inside the tank
(Figure 4.5-2).  The American Petroleum Institute has designated
the term "covered floating" roof to describe a fixed roof tank
with an internal steel pan-type-floating roof.  The term "inter-
nal floating cover" has "been chosen by the API to describe
internal covers constructed of materials other than steel.
Floating roofs and covers can be installed inside existing fixed
roof tanks.  The fixed roof protects the floating roof from
the weather, and no provision is necessary for rain or snow
removal or seal protection.  Antirotational guides must be pro-
vided to maintain roof alignment, and the space between the fixed
and floating roofs must be vented to prevent the formation of a
flammable mixture.

          Variable Vapor Space Tanks

          New variable vapor space tanks have not been built for
several years.  However, tank manufacturers have reported that
new orders for variable vapor space tanks have been received.

          Variable vapor space tanks are equipped with ex-
pandable vapor reservoirs  to accommodate vapor volume fluctua-
tions attributable to temperature and barometric pressure
changes.  A variable vapor space device is normally  connected
to the vapor spaces of one or more fixed roof tanks.  The two
                               250
-------
most common types of variable vapor space tanks are lifted
roof tanks and flexible diaphragm tanks.

          Lifter roof tanks have a telescoping roof that fits
loosely around the outside of the main tank wall.  The space
between the roof and the wall is closed by either a wet seal
which consists of a trough filled with liquid, or a dry seal
which employs a flexible coated fabric in place of the trough
(Figure 4.5-7).B

          Flexible diaphragm tanks utilize flexible membranes
to provide the expandable volume.  They may be separate gas-
holder type units, or integral units, mounted atop fixed roof
tanks (Figure 4.5-8).9

4.5.2.1   Emissions

          There are four major sources of emissions associated
with the storage of intermediate volatility liquids:  floating
roof standing storage losses, floating roof withdrawal losses,
vapor recovery system vents and variable vapor space filling
losses.

          Floating roof standing storage losses result from
causes other than breathing or change'in liquid level.  The
largest potential source of this loss is attributable to an
improper fit of the seal and shoe to the shell, which exposes
some liquid surface to the atmosphere.  Some vapor may escape
through the gaps created by these improper seal fits.

          Flo-ai:ing roof withdrawal losses result from evapora-
tion of stock which wets the tank wall as the roof descends
during emptying operations.  This loss is small in comparison
to other types of losses.10
                               251
-------
NOZZLE
     Figure 4.5-7.  Lifter  roof storage tank with wet seal
                PRESSURE
               VACUUM VEKTS
         MOZZLi.
     Figure 4.5-8.   Flexible diaphragm tank (integral  unit)
                                 252
-------
          When intermediate volatility liquids are stored in
fixed roof tanks with vapor recovery systems,  there is an
emission from the vapor recovery unit vent.   Vapor recovery
systems recover the organic portion of tankage vapors and vent
the air portion back to the atmosphere.  Because of inefficien-
cies in the vapor recovery systems, small quantities of volatile
organics are also vented with the air to the atmosphere.11  In
many, if not most, vapor recovery systems where storage tank
vapors are collected, the collected vapor stream,  after heavy
ends are collected, is burned directly in a furnace.  In that
case the system is not venting organic vapors to the atmosphere.

          Variable vapor space filling losses result when vapor
is displaced by the liquid input during filling operations.
Since the variable vapor space tank has an expandable vapor
storage capacity, this loss is not as large as the filling loss
associated with fixed roof tanks.  Loss of vapor occurs only
when the vapor storage capacity of the tank is exceeded.

          The total amount of evaporation loss from storage
tanks for intermediate volatility liquids depends on the factors
lis.ted in Section 4.5.1.1.  The American Petroleum Institute has
developed empirical formulas, based on field testing, that cor-
relate evaporative losses for intermediate volatility liquids.
These equations and their, .application are presented in Supplement
No. 7 of EPA Document AP-42, Compilation of Air Pollutant Emis-
jLion Factors.:2  Emission rates calculated from these equations
for some "typical" storage tank conditions are presented in
Table 4.5-2.  The factors in AP-42 and the API bulletins on
which they are based"are presently being revised.
                              253
-------
4.5.2.2   Control Technology

          Although not generally" applied,  there are  several
approaches available for controlling emissions  from  the storage
of intermediate vapor pressure liquids.   For new construction
tankage, emissions can be controlled by  converting to another
form of intermediate vapor pressure tankage with lower emission
losses.  It is also possible to control  emissions by employing
low pressure tankage.  Low pressure tanks operating  between  119
and 203 kPa (17-29 psia) have been used  for the storage of motor
gasolines, pentanes, and natural gasolines having vapor pressures
up to 203 kPa (29 psia).  With proper design, these  low-pressure
tanks can prevent breathing losses from  intermediate volatility
liquids.  Working losses occur during filling when the pressure
of the vapor space exceeds the pressure  vent.setting and vapors
are expelled.  These working losses depend on the pump-in rate,
the rate of heat dissipation, and the pump-out  rate.  Working
losses may be reduced by increasing the  pressure of  the vent
setting; the increased cost of the high  pressure tank may pro-
hibit this option.  Vapor recovery systems may be required to
control working losses.ls

4-5.3  '-  Pressure Storage Tanks for High Volatility Liquids

          High volatility liquids are generally stored in sealed
pressure tanks.  Pressure tanks are designed to withstand rela-
tively large pressure variations without incurring a loss.  They
are constructed in many sizes and shapes, depending  on the operat-
ing pressure range.  Noded spheroid tanks have been  accepted for
operating pressures up to 203 kPa (29 psia).  Spheroids have been
operated at pressures up to 308 kPa (45  psia).   High-pressure
tanks, either cylindrical, spherical, or blimp-shaped, have been
operated at pressures up to 1.8 MPa (265 psia).l*
                             254
-------
4.5.3.1   Emissions

          Pressure tanks are generally sealed, no loss systems.
However, pressure tank losses due to relief vent opening occur
when the pressure inside the tank exceeds the design pressure.
This happens only when the tank is filled improperly, or when
abnormal vapor expansion occurs.  Losses can also occur during
the filling of low pressure tanks which are not equipped with
means for disposing excess displaced vapors.  These are not
regularly occurring events, and pressure tanks storing volatile
liquids are not a significant source of loss under normal
operating conditions.15

4*5.3.,'2-.  Control Technology

          High pressure tanks represent the highest level of
emission control for volatile liquid storage.  There should be
no need for controls on high pressure tankage.  If losses  occur
from high pressure tankage, they indicate that the tankage is
misapplied or in improper working order.  Good housekeeping and
routine maintenance are the primary emission control technologies
available for these losses.

4.5.4     Energy, Cost, and Environmental Impact of Controls

          Controlling emissions of volatile organic compounds
from storage tanks accomplishes two things:  improvement of am-
bient air quality and conservation of a substance which is convertible
to energy by combustion.  Energy requirements for storage tank
control measures are negative; that is, energy is saved by re-
ducing losses of organic compounds to the atmosphere.  An ex-
ample of energy savings may be seen in Table 4.5-4 which pre-
sents a comparison of losses from fixed roof and floating roof
                             255
-------
            TABLE 4.5-4.   ENERGY SAVINGS REALIZED BY USING FLOATING ROOF TANKS
                            IN A TYPICAL 16,000m3 (100,000  BBL/DAY) REFINERY 16
Substance
Stored
Crude Oil
(2.0 Ib RVP)
Crude Oil
(6.0 Ib RVP)
Gasoline
(regular)
Gasoline
(premium)

Storage
Capacity
185,551 m3
(1,167,080 bbl)
185,551 m3
(1,167,080 bbl)
75,970 m3
(477,840 bbl)
37,985 m3
(238,020 bbl)

Throughput
8,000 mVday
(50,000 bbl/day)
8,000 m3/day
(50,000 bbl/day)
7,000 mVday
(45,000 bbl/day)
3,600 mVday
(22,500 bbl/day)

Fixed Roof
Losses
753 m3/yr
(4,738 bbl/yr)
3,604 mVyr
(22,669 bbl/yr)
5,685 m3/yr
(35,758 bbl/yr)
2,845 m3/yr
(17,897 bbl/yr)

Floating Roof
Losses
43 mVyr
(270 bbl/yr)
146 mVyr
(921 bbl/yr)
192.7 mVyr
(1,212 bbl/yr)
96.3 m3/yr
(606 bbl/yr)
TOTAL
b
Energy
Savings
26 TJ/yr
(2.5xl010 Btu/yr)
129 TJ/yr
(12.2xlOl° Btu/yr)
183 TJ/yr
(17. 3x10 10 Btu/yr)
91 TJ/yr
(8. 65x10 10 Btu/yr)
430 TJ/yr
(40.65xl010 Btu/yr)
. A typical mix of tank sizes  is assumed.
 Assumed heating values - 372 GJ/m3 (5.6xl06 Btu/bbl) for crude; 3.2 GJ/m3  (5-OxlO6  Btu/bbl)  for gasoline.
-------
 tanks  storing  crude  and gasoline in a typical 16,000 m3/day
 (100,000 barrel/day) refinery.  The data are API estimates based
 on  a  typical mix of  tank sizes.17  Crude and gasoline storage
 represent  the  largest volume of products stored in a refinery,
 but the total  energy potentially saved will be even larger if
 other  refinery products are also stored in tanks using control
 measures.

           Conserving the organic compounds represents a cost
 savings as well as an energy savings to the producer.  In many
 cases  the  value of the recovered product exceeds the cost of
 the control method.  Table 4.5-5 illustrates the cost involved
 in  substituting floating roof  tanks for fixed roof tanks.  Costs
 for two tank capacities and three  products are presented.     , .••--

           The  cost effectiveness of retrofitting fixed roof tanks
 with  floating  roofs  varies with the size of the tank, the true
 vapor pressure, and  the number of  turnovers.  The cost  (or
 credit) per megagram (ton) of  controlled substance is presented
 in  Table 4.5-6.  Separate values are given for gasoline and
 crude  oil  because of the different economic values and  emission
 rates  of the two liquids.  To  illustrate the fact that  larger
 tanks  are  more cost  effective  than smaller ones, the numbers
 are presented  graphically in Figures 4.5-9 and 4.5-10.  The
 parameters are explained-more  fully in  "Control of Volatile
 Organic Emissions  from Storage of  Petroleum Liquids  in  Fixed-
 Roof -Tanks, "EPA,  December  1977.

           Estimates  of installed costs  for fixed roof tanks are
 $161,000 for 8000 m3 (50,000 bbl)  capacity, $257,000 for  16,000
•m3  (100,000 bbl) capacity, and $379,000 for 24,000 ia3  (150,000
 bbl)  capacity.  Annual operating cost estimates are  $29,900 for
 8000 m3  (50,000 bbl) capacity, $48,600  for 16,000 m3  (100,000
 bbl)  capacity, and $72,200 for 24,000 m3  (150,000 bbl)  capacity.2:
                              257
-------
                    Figure  4.5-9.   Cost  Effectiveness of Controlling  Emissions  From
                                       Existing Fixed  Roof  Gasline Tanks
CD
                                                                                                Tank      Product
                                                                                                Turn-        TVP
                                                                                              Overs/^r       kPa
                                                                                    A low Values     513.8
                                                                                    I Hedlum Values 10        41.4
                                                                                    C High Values   20        69.0
                                   4000      8000     12.000     16.000    20,000

                                                          .Tank Sli* (10» 1)
24.000
                                                                                                         OJ
-------
                         Figure 4.5-10.
Cost Effectiveness of  Controlling Emissions
From Existing Fixed Roof Crude Oil Tanks
                             300
                      •u
                      01
tO
                          Moo)
                                      4000      8000      12,000     16,000

                                                        Tank Site (10* ')
                              20.000
                                                        Tank   Product
                                                        Turn-    IVP
                                                       Oyfrs/yr   kPa
                                           A Low »«Jiie$     ~5     "1S.§
                                           8 Median Values  10      41.4
                                           C High Values    20      69,0
,000
-------
           TABLE 4.5-5.  COSTS FOR SUBSTITUTING FLOATING ROOF TANKS FOR FIXED
                         ROOF TANKS*,18



      Storage Capacity          Material Stored       New Tank Costs       Retrofit Costs


        13,000 m3
      (80,400 bbl)                Crude Oil               - 13,630             -6,950


        10,000 m3                                ;
      (60,800 bbl)     ,           Gasoline           :     - 16,690            -10,290


        10,000 ms
      (60,800 bbl)                Naphtha Jet Fuel            -                17,520
                          '''
aCosts are based on several assumptions.  See original reference for bases for estimates.

 Negative signs indicate that savings from the recovered product exceed the annual cost.
-------
TABLE 4.5-6.  COST EFFECTIVENESS OF INSTALLING FLOATING ROOFS
              ON FIXED ROOF PETROLEUM LIQUID STORAGE TANKS,
              $ PER Mg ($ PER TON)l 9

True Vapor Pressure (kPa)
(psia)
No. Turnovers /Year
Tank Size
1590 m3 (10,000 bbl)
gas

crude oil
- ---". '
8750 m3 (55,000 bbl)
gas

crude oil

23,850 m3 (150,000 bbl)
gas

crude oil

Low
13.8
(2.0)
5


65
(59)
240
(220)

-35
(-32)
80
(73)

-60
(-55)
30
(28)
Medium
41.4
(6.0)
10


-75
(-68)
5
(4)

-115
(-100)
-75
(-68)

-125
(-114)
-90
(-82)
High
69.0
(10.0)
20


-115 ....
(-100)
-80 ." ' '.".'
(-73) -

-135
(-123)
-115
(-100)

-140
(-130)
-120
(-110)
                             261
-------
          Costs for retrofitting existing fixed roof tanks with
an internal floating cover and preliminary seal are presented
in Table 4.5-7.  These costs are for the model situations
described above for Tables 4.5-6.  Cost parameters are also
given in the reference.

          Annual operating costs for Internal floating covers in
fixed roof tanks are $28,600 for 8,000 m3 (50,000 bbl) capacity,
$45,600 for 16,000 m3  (100,000 bbl) capacity and $66,000 for
24,000 m3 (150,000 bbl) capacity.2"

          Estimated installed costs for pontoon floating roof
tanks are $176,000 for 8000 m3  (50,000 bbl) capacity, $279,000
for 16,000 m3  (100,000 bbl) capacity, and $403,000 for 24,000 m3
(150,000 bbl)  capacity.  Annual  operating costs are estimated at
$25,000 for 8,000 m3  (50,000 bbl) capacity, $39,500 for 16,000 m3
(100,000 bbl)  capacity, and $57,100 for 24,000 m3  (150,000 bbl)
capacity.25  Purchase  prices for double, deck tanks are.estimated
at $56,000 and $70,000 for 5,000 and 6,000 m3  (30,000 and 40,000
bbl) capacity  tanks.26 Installed costs would be somewhat higher.
                              262
-------
                     Table 4.5-7.   CONTROL COST ESTIMATES  FOR MODEL EXISTING FIXED ROOF TANKS
      Control Device
                                                 Internal Floating Roof and Closure Seal
      Facility Size
                                     15.2 m diameter
                                      9.2 m height
                                     1590 x 10  1 capacity
             30.5 m diameter
             12.2 m height
             8750 x 10  1 capacity
               45.7 m diameter
               14.6 m height
               23,850 x 10  1 capacity
to
Co
      Installed Capital  Cost  ($000) :a
      Annual  Operating  and Maintenance
      Cost  ($000) :b
Annual! zed Capital Charges ($000)
     Total Annual Control System Cost
        (not  including petroleum credits)
        ($000):d
15.0



 0.9


 2.1


 3.0
31.0



 1.8


 4.5


 6.3
57.0



 3.4


 8.3


11.7
    aHedian  installed costs of retrofitting internal floating roofa and closure seals on existing fixed roof
      tanks per references 5,6,7, and 8; does not include the costs of cleaning and degassing tanks, correction
      of  tank defects and loss of use of tanks during retrofit.

    bFer EPA estimate.

    cCapital recovery costs (using capital recovery factor with 10% annual interest rate and 40 year internal
      floating roof life) plus 47. of installed capital cost for property taxes, insurance, and administration.

      Sum of  annual operating and maintenance cost plus annualized capital charges; but, does not include
      petroleum credits  (savings).
-------
            There are no secondary pollutant problems associated
  with utilizing the control techniques presented in this section.
  Preventing volatile organic emissions to the atmosphere is con-
  sidered a positive environmental impact.

  4.5.5     References

  1.  Burklin, C.E.  and R.L. Honerkamps, Revision of Evaporative
      Hydrocarbon Emission Factors, Final Report.  Radian Cor-
      poration,  Austin, Texas.   June 1976.

  2.  Environmental Protection Agency.   Control of Volatile Or-
      ganic Emissions from the Storage of Petroleum Liquids in
      Fixed Roof Tanks.  OAQPS, Research Triangle Park, N.C.
      December,  1977.
     *
3-4.  American Petroleum Inst., Evaporation Loss Committee.
      Evaporation Loss from Fixed-Roof Tanks.  Washington, D.C.
      Bull. 2818.  1962.

  5.  Reference 2.

  6.  Burklin, C.E., et al.  Control of Hydrocarbon Emissions
      from Petroleum Liquids.  Radian Corporation Contract No.
      68-02-1319, Task 12.  EPA 600/2-75-042..  PB 256~650/ST.
      Sept. 1975.

7-8.  American Petroleum Inst., Evaporation Loss Committee.
      Evaporation Loss from Floating-roof Tanks, Washington, D.C.
      Bull.  2517.   1962.

8-9.  American Petroleum Inst., Evaporation Loss Committee.  Use of
      Variable Vapor-Space Systems to Reduce Evaporation Loss.
      New York.   Bull. 2520.  1964.

                                264
-------
   10.   Reference 7.

   11.   Reference 6.

   12.   Reference 1.

   13.   American Petroluem Inst.,  Evaporation Loss Committee.
        Evaporation Loss from Low-Pressure Tanks,  Washington,  B.C.
        Bull.  2516.   1962.

   14.   American Petroleum Inst. ,  Evaporation Loss Committee.   Evap-
        oration Loss in the Petroleum Industry,  Causes and Control.
        Washington.  D.C.  API Bull.  2513.   1959.  (Reaffirmed 1973)

   15.   Reference 6.                                         .

16-17.   American Petroleum Institute, Hydrocarbon Emissions from
        Refineries.   Washington,  D.C., Publication No. 928, July
        1973.

   18.   Hark D., S.  Sobotka, and W.  Johnson, Economic Impact of
        EPA's Regulations on the Petroleum Refining Industry,  Vol-
        ume 2:  Industry Description and Technical Analysis.  EPA
        Contract No. 68-01-2830.   Stamford Conn.,  Sobotka and Co.
        April 1976.

19-21.   Reference 2.

   22.   MSA Research Corp., Hydrocarbon Pollutant Systems Study,
        Vol. 1, Stationary Sources,  Effects, and Control, APTD-1499
        PB 219073, Evans City, PA.,  MSA Research Corp, 1972.

   23.   Reference 2.

24-25.   Reference 22.

                                  265
-------
26.  Nichols,  Richard A.   Control of Evaporation Losses in Gasoline
     Marketing Operations, Irvin, Ca.,  Parker-Hannifir, 1973.
                                266
-------
4. 6       Petroleum Transportation and Market ing Sjistegisi

          Figure 4.6-1 shows the operations involved in the
transportation and marketing of petroleum liquids.  Each oper-
ation represents a potential source of evaporative organic
emissions.  Crude oil is transported from production operations
to the refinery via tankers, barges, tank cars, tank trucks,
and pipelines.  Refined petroleum products are conveyed to  fuel
marketing terminals and petrochemical industries in the same
manner.  From the fuel marketing terminals the fuels are deliv-
ered via tank trucks to service stations, commercial accounts.,
and local bulk storage plants.  The final destination for gaso-
line is normally a motor vehicle gasoline tank.  A similar''d'i's.-
tribution path may also be developed for fuel oils and other.
petroleum products.

          This section presents the emissions and available'
control technology for the four major transportation and mar-
keting systems:  pipelines, ship and barge terminals, tank
truck and rail car terminals, and gasoline service stations,
Only the loading and unloading sources associated with these
emissions are discusse-d in this section.  .The storage emissions
associated with each of these systems are dicusssed in Section
4.5 on Storage Tanks.  •

4.6,1    • • •Pipelines

          The two primary sources of organic emissions from. •-•
transportation by pipeline are compressor station engines
and fugitive pipeline emissions.  Sources of fugitive ends-  .-
sions and their control have been discussed in Section 4.1.
                               267
-------
N>
O>
OD
         m
         £
                     "*'     '•*"
                       TANK CAR
                                     MARKETING
                                      TERMINAL
                                      STORAGE
                                       TANKS
COMMERCIAL
 ACCOUNTS'
 STORAGE
  TANKS
                                                                              AUTOMOBILES
                                                                                AND
                                                                              OTHER MOTOR
                                                                               VEHICLES
      Figure 4.6-1.  Flowsheet of petroleum production, refining,  and distribution systems.
                       (Sources  of organic evaporative  emissions are  indicated by vertical  arrows
-------
          Compressor stations are employed to maintain the flow
of petroleum fluids through long distance pipelines.  Often
the large pumps and compressors used in these compressor sta-
tions are driven by natural gas internal combustion engines.
The natural gas used by these engines may be tapped from the
pipeline or supplied by external sources.

          The exhaust gases from internal combustion engines
contain significant quantities of unburned hydrocarbons and
organic products of incomplete combustion.  Average measured
hydrocarbon emissions from natural gas-fired internal combus-
tion engines are 22 g/m3 (1.4 lb/103 ft3) fuel burned.  Average
aldehyde emissions are 1.6 g/m3 (0.1 lb/103 ft3) of fuel burned.
A large portion of the hydrocarbon emissions from natural .gas-
fir e-d internal, combustion engines consists of methane, a hydro-"
carbon of low photochemical reactivity.,1'2'3              ....

          Hydrocarbon and organic emissions from internal com-
bustion engines can be controlled using technology  developed
for automobile exhaust emissions.  The least expensive control
technique is carburetion adjustment to achieve more efficient
fuel combustion..  Improved combustion efficiency results in
the conversion o'f more fuel to C02 and' H20 thereby  reducing
the level of -unburned fuel in the exhaust.  Internal combus-
tion engine exhaust can also be routed through catalytic con-
verters which oxidize hydrocarbon and organic components to
C02.and H20.  Catalytic converters are considered very expen-.-
sive for--this application and have not been applied to pipe-
line compressors.  Emission characteristics, control  technol-
ogy costs, energy requirements, and environmental impacts are
further discussed in Section 4.13.2, Stationary Internal Com-
bustion Sources.
-------
          The current trend is towards decreased use of inter-
nal combustion engines.  Low reliabilities and increasing prob-
lems with the cost and availability of natural gas have decreased
the use of internal combustion engines in recent years, and made
the use of electric motors more favorable. **

4.6.2     Ship and Barge terminals

          Marine terminals are generally located at the end of
pipelines or adjacent to refineries and chemical plants.
Equipment located at marine terminals includes storage tanks,
pumps, valves, and loading arms and hoses.  The four major
sources of hydrocarbon and organic emissions from marine ter-
minals are storage tanks, leaks, loading operations, and bal-
lasting operations.  Emissions from storage tanks are discussed
in Section 4.5, and emissions from leaks are discussed in
Section 4.1.

4.6.2.1   Emissions from Loading Operations

          Ship and barge loading is the largest source of emis-
sions, from .marine terminal operations.  Loading losses occur as
hydrocarbon and organic vapors'in empty cargo tanks are dis-
placed to the atmosphere by the-liquid loaded into  the cargo
tank.  The'vapors displaced from"the  cargo tanks are a-composite
of 1) vapors formed in the empty tank by evaporation of residual
product from the previous haul,- 2) vapors generated in the tank
as new product is loaded, and 3) vapors in the ullage prior to
discharging cargo.  The quantity of hydrocarbon and organic
losses from marine loading operations is, therefore, a function
of the following parameters:5

          1.  physical and chemical characteristics
              of the previous cargo
                               270
-------
          2.  mathod of unloading the previous cargo
          3.  operations during the transport of the
              empty vessel to the loading terminal
              (i.e., purging, cleaning, inerting, etc.)
          4.  method of loading the new cargo
          5.  physical and chemical characteristics
              of  the new cargo.

          The standard method of loading ships and barges is
bottom loading  (Figure 4.6-2).  In the bottom loading method,
the fill pipe enters the vessel tank from the bottom.  During
the major portion of the loading operation  the fill pipe is
below the liquid  level, thereby reducing liquid turbulence and
vapor-liquid contacting.  Vapor emissions are significantly
lower than  those  produced-by splash loading.

          The cruise history of a cargo carrier is another impor-
tant factor in  loading losses.  Emissions are generally lowest
when the cargo  tanks are free from vapors prior to loading.  Clean
cargo tanks normally result from either carrying a non-volatile
liquid such as  heavy fuel oil in the previous haul, or from
cleaning or Ventilating  the empty cargo  tank prior to  loading
operations.

          Another cruise history factor * affecting tanker emissions
is  the ballasting of cargo tanks.  Ballasting is discussed in  the
following section.  The ballasting of  cargo tanks reduces the
quantity of vapor returning in  the empty tanker, thereby reducing .
the quantity of vapors emitted  during  subsequent tanker loading'
_operations.

          When  the cargo tanks  are  filled,  the  pressure/vacuum
valve  (P/V) is  opened.   Organic vapors are  vented  through  the
open ?/V valve  at mast head  level  and/or through  the  ullage
                               271
-------
                           P/V
                           VALVE
                                             ULLAGE HATCH
                                                  ULLAGE
                                                  DOME
             VAPOR COLLECTION LINE
                                       VAPORS
                               ill     1
                                        SHIP'S
                                         HULL
                                                           SHIP'S
                                                           WING
                                                           TANK
Figure 4.6-2.  Emissions  from uncontrolled vessel loading.
                              272
-------
hatch at deck level.  This practice varies depending on corpor
ate safety policies.

          Emissions from loading volatile liquids onto marine
vessels can be estimated within 30 percent using the following
expression :

                  SPM
where -.

          L, = loading loss, kg/m3 of liquid loaded  (lb/103 gal)
          K  = constant, 12.04 x 10" 5 kg-mole °K/Pa tns  (12.46
               Ib-mole °.R/psia 10 3 gal)
          M  == molecular weight of vapors, kg/kg-mole  (Ib/lb-mole)
          P  = true vapor pressure of liquid loaded, Pa (psia) .
          T  - bulk temperature of liquid loaded,  °K  (°R)
          S  * a saturation factor

The saturation factor  (S) represents the expelled  vapor's  frac-
tional approach to saturation and accounts for the variations
observed in emission rates for different loading methods.  The
suggested saturation factor for loading ships is 0.2  and for
loading barges is 0.5. 6                              .. :  .

          Recent studies conducted by EPA, State Air  Control
Agencies, WOGA, API, and individual oil companies  on  gasoline
loading losses from ships and barges have led to the  development
of more accurate -emission factors for these specific  loading op-
erations.  These factors are presented in Table 4.6-1  and  should
be used instead of the above equation for gasoline loading opera-
tions at marine terminals.  Data on losses from crude  marine-'
                                173
-------
               TABLE  4.6-1.   EMISSION  FACTORS  FOR GASOLINE  LOADING  ON  SHIPS  AND  BARGES7
1*0
Hydrocarbon Emission Factors
Vessel Tank Condition
Cleaned and Vapor Free
lb/10* gal transferred
kg/109 liter transferred
Ballasted
lb/10* gal transferred
kg/101 liter transferred
Unc leaned - dedicated service
lb/10s gal transferred
kg/103 liter transferred
Average cargo tank condition
lb/103 gal transferred
kg/101 liter transferred
Shins Ocean Barges
Range Average Range Average

0 to 2.3 1.0 0 to 3 1.3
0 to 0.28 0.12 0 to 0.36 0.16

0.4 to 3 1.6 0.5 to 3 2.1
0.05 to 0.36 0.19 0.06 to 0.36 0.25

0.4 to 4 2.4 0.5 to 5 3.3
0.05 to 0.48 0.29 0.06 to 0.60 0.40

c 1.4 c c
0.17
Barges
Range Average

c 1.2
0.14

d d


1.4 to 9 4.0
0.17 to 1.08 0.48

c 4.0
0.48
             a. emission factors are rated B; good
             b. Or prior low vapor pressure cargo
             c. These values are not available
             d. Barges are not normally ballasted
-------
loading is available from Western Oil and Gas Association.
4.6.2.2   Emissions from Ballasting Operations^

          Non-segregated ballasting operations are the second
largest source of organic emissions from marine terminals.   Cargo
tanks on large tankers are often filled with water after cargo is
unloaded.  The ballast water improves the stability of the empty
tanker on rough seas.  Ballasting emissions occur as organics-
laden air in the empty cargo tank is displaced to the atmosphere
by ballast water.  However when separate segregated ballast tanks
are employed to store ballast water, there are no ballasting
emissions.

          The quantity of hydrocarbon and organic losses from
tanker ballasting operations is, therefore, a function of the
physical and chemical characteristics of the unloaded cargo,
the unloading method used, ambient conditions, and the quantity
of ballast taken onboard.  Although ballasting practices vary,
individual cargo tanks are ballasted 80 to 100% and the total
vessel is ballasted between 20% and 40% of capacity.  Ballasting
emissions from gasoline  and crude oil tankers are approximately
0.09 kg/103 liter  (0.8 lb/103 gal) total capacity and 0.07 kg/
103 liter (0.6 lb/103 gal) total capacity, respectively.  These
estimates are for motor  gasolines and medium volatility crudes
with Reid vapor pressures of about  35 kPa  (5 psia).8  A measure-
ment program being conducted by eight oil companies and known
as The 8-31 Marine Emissions Study will soon provide data that
may supercede these estimates.
                               275
-------
4.6.2.3   Marine Terminal Control-Technology9

          Control measures for reducing marine terminal emis-
sions include alternate loading and unloading  procedures and
vapor recovery equipment.  Data on these control techniques is
limited and much of it has not been verified.

          Procedural changes which reduce the  emissions from
loading and ballasting operations are not well documented.   Ini-
tial investigations indicate that vapor freeing ballasted and
empty cargo tanks at sea can potentially reduce tanker loading
losses from 50 percent to 60 percent.  Cleaning is not considered
an available control measure for barges.10

          Limited additional emission reductions may be achieved
by employing slow initial loading, fast bulk loading and slow
final loading.  Slow initial loading reduces the turbulence
caused during the flow of liquids into the bottom of empty cargo
tanks.  The evaporation of volatile liquids is reduced under
conditions of low turbulence.  After the opening of the inlet
pipe is covered, with product, the cargo tank should be filled
rapidly to reduce the tank filling time and consequently reduce
the time available for additional vapor formation.  The final
filling rate should again be slow to reduce vapor turbulence in
the vicinity of the ullage hatch as the liquid level approaches
the top.  It is estimated that changes in loading procedures
would reduce loading losses from 60 to 80 percent.11  These re-
ductions have not been verified with actual operating data.

          Procedural changes for reducing ballasting emissions
include quick unloading of cargo, careful stripping of residual
product from the empty tank bottom, and prompt partial ballasting,
Although partial ballasting allows sloshing and provides insuf-
ficient stability in rough seas, additional ballast can be taken

                              276
-------
on out of port where ballasting emissions are of less concern.
Estimates of the control efficiency of procedural changes in
ballasting operations are unavailable.12

          Theoretically, one of the most effective control mea-
sures for reducing loading and ballasting emissions would be the
application of a vapor recovery system as shown in Figures 4.6-3
and 4.6-4.  However, no controls are currently being applied on
gasoline or crude oil marine terminals.  A marine terminal vapor
recovery system would include piping which collects vapors from
each cargo tank and conveys them to an onshore vapor control
unit.  Theoretically, the vapor control unit would either incin-
erate the vapors or recover them by refrigeration, compression,..
adsorption, or absorption.  The projected efficiency of vapor..
control units.is 90+ percent.13

4.6.2.4   Energy, Cost, and Environmental Impact of Controls
.•
          The procedural changes mentioned above are very new
ideas.  For this reason and because of the very nature of the
control technology, costs and energy considerations are difficult
to define.  Capital costs involved wonld'be minimal; however,
there would be an associated increase in operating costs.

          Projected installed capital cost estimates for shore-
side vapor recovery units in a marine terminal range from $100,000
to $2,000,000 per 1600 m3  (10,000 bbl)/hr loading capacity.  The
average projected capital cost is $1,000,000 per 1600 m3  (10,000
bbl)/hr loading  capacity.  The average projected cost for ship
modification  is  $0.35 million per ship, and the average projected
cost for barge modification is $67,000 per barge.  Average annual
projected operating costs for shoreside vapor recovery systems
are $15 per 159 m3  (1000 barrels) transferred.114
                               277
-------
  TO
N-SHORE
VAPOR
CONTROL
SYSTEM
ULLAGE HATCH
     ULLAGE
     POME
            VAPOR
           DLLECTI
            HEADER
                  GASOLINE-
                                                  SHIP'S
                                                   HULL
             -SHIP
              DECK
^ VAPOR COLLECTION LINE ^ A f \
"ION
R

* \
X ' k v" \
' /•- / t \
(, 1 1 > \
/ / / : '
VAPORS
ill 1 1
I i ; i
•1 • . • i . I 1
	 	 rsAsni IMP 	

/
. , j Jr
J „ , 	 ; 	 ^f

                                                                     SHIP
                                                                     WINC
                                                                     TANI-
               Figure 4.6-3.  Ship-side  vapor collection system.
                                      278
-------
r-j
                 TANKfH
                                                                                   RECOVERED
                                                                                   PRODUCT
                                                                                 •*" RETURNED T
                                                                                   KEFIHiAV
                Figure 4.6-4.
Typical Application of Vapoir Collection System For
Reduction of Marine Terminal Loading Emissions.
-------
          Condensing type vapor recovery units generate a minor
purge stream of water which is condensed with the hydrocarbon
vapors.  This oily water is a small volume waste stream which
can be piped to the refinery's waste water treatment plant.
4.6.3     Tank Truck and Rail Car Terminals and Bulk Plants
                                                           1 5
          Tank truck and rail car terminals for the loading and
unloading of« crude oil, petroleum products, and organic chemi-
cals are located at the end of pipelines or near refineries,
marine terminals, and chemical plants.  Bulk plants are secondary
distribution facilities receiving product by tank truck and dis-
tributing it by smaller tank trucks.  Equipment located at tank
truck and rail car terminals and bulk plants include storage
tanks, pumps,  valves, and loading arms and hoses.  The two major
sources of hydrocarbon and organic chemical emissions from tank
truck terminals, rail car terminals, and bulk plants are storage
tanks and loading operations.  Emissions from storage tanks are
discussed in Section 4.5.

4.6.3.1   Emissions from Loading Operations

          Loading operations are a very significant source of
emissions from tank truck and rail car terminals and bulk plants.
The mechanisms of vapor generation and the factors affecting loss
rate are the same as those described for marine terminal loading
operations.

          Methods of loading cargo carriers are shown in Figure
4.6-5.  In the splash loading method, the fill pipe dispensing
the cargo is only partially lowered into the cargo tank.  Signi-
ficant turbulence and air-liquid contacting occurs during splash
loading,  resulting in high levels of vapor generation and loss.
If the turbulence is high enough, liquid droplets will be en-
trained in the vented vapors.
                              280
-------
                               IUMKIKMO nu.
                        TO «teo»t»»
                                             CAM3O TJIMK
                              •OTTOH lOHOIHt
Figure 4,6-5,  Three Methods  of Loading Cargo Carriers
                               281
-------
          A second method of loading is submerged loading.   The
two types of submerged loading are the submerged fill  pipe
method and the bottom loading method.   In the submerged fill
pipe method, the fill pipe descends almost to the bottom of
the cargo tank.  In the bottom loading method, the fill pipe
enters the cargo tank from the bottom.  During the major por-
tion of both submerged loading methods, the fill pipe  opening
is below the liquid level.  The submerged loading method sig-
nificantly reduces liquid turbulence and air-liquid contact.
Submerged loading produces lower vapor losses than splash loading.

          A cargo carrier in "dedicated gasoline service" trans-
ports only gasoline.   Tanks are not cleaned or vented  between
trips.  An empty cargo tank in dedicated gasoline service retains
a significant concentration of vapors generated by evaporation
of residual gasoline product.  These residual vapors are expelled
along with newly generated vapors during the subsequent loading
operation.

          Another type of cargo carrier is one in "dedicated
gasoline balance service".  Cargo carriers in dedicated gasoline
balance service pick up vapors displaced during unloading oper-
ations and transport these vapors in the cargo tanks back to the
loading terminal.  Figure 4.6-6 shows a tank truck in dedicated
gasoline balance service unloading gasoline to an underground
service station tank.  The tank truck  is simultaneously being
filled with displaced gasoline vapors to be returned to the
truck loading terminal.  The vapors in a cargo carrier in dedi-
cated gasoline balance service approach saturation with hydro-
carbons or organic compounds.

          Emissions  from loading tank  trucks and rail cars  can
be estimated within  30 percent using the equation presented  in
Section 4.6.2.1.  Table 4.6-2 lists suggested saturation factors
for tank truck and rail car loading.   The emission factor for

                              282 .
-------
                                             7AKK VEMT
•AMIFQLO FOR RETURNING VAPORS
              TRUCK STORAGE^   I
              COMPARTMENTS
 FIGURE 4.6-6 TANKTRUCK  UNLOADING  INTO  AN  UNDERGROUND
              SERVICE  STATION STORAGE  TANK. TANKTRUCK
              IS PRACTICING " VAPOR  BALANCE " FORM  OF
              VAPOR CONTROL,
                            283
-------
       TABLE  4.6-2.   S FACTORS FOR CALCULATING TANK TRUCK
                       AND RAIL CAR  LOADING  LOSSES16'a
      Cargo Carrier
      Mode  of Operation
S Factor
Tank Trucks and Tank Cars
Submerged  loading of a clean       0.50
   cargo tank

Splash loading of a clean         1.45
  cargo tank

Submerged  loading:  normal        0.60
  dedicated gasoline service

Splash loading:  normal           1.45
  dedicated gasoline service

Submerged  loading:  dedica-       1.00
  ted gasoline balance service

Splash loading:  dedicated        1.00
  gasoline balance service
aEr>ission  factors  are rated A: excellent
                                  284
-------
hydrocarbon emissions generated during submerged fill (top or
bottom) gasoline loading operations is 600 mg hydrocarbons emitted
per liter of gasoline loaded (5 lb/103 gal).  This figure repre-
sents 40-507. hydrocarbon saturation of the air in the tank trucks.1

4.6.3.2   Control Technology

          Emission control technology for tank truck and rail
car loading includes the use of modified loading techniques,
vapor recovery units, and the balance system.  A 40 to 60 per-
cent reduction in emissions can be achieved by the conversion
of loading procedures from splash loading to bottom loading.18
This conversion requires moderate piping modifications to both
the cargo-carrier and the loading rack.

          If bottom loa-ding is practiced in conjunction with the
application of a vapor recovery system, the emissions from tank
truck and rail car loading operations can be reduced 90 to 98
percent.  A tank truck terminal vapor recovery system is pre-
sented in Figure 4.6-7.  In a properly operating vapor recovery
system, vapors displaced from the cargo tanks during product
loading are collected in a vapor header on the cargo carrier
and conveyed to a vapor recovery unit. • Through processes such
as refrigeration, condensation, compression, or absorption, the
vapors are recovered as liquid product.  Occasionally incinera-
tion and catalytic combustion systems are used to dispose of
loading vapors.

          The vapor balance system is an additional vapor con-
trol technique applicable only to facilities such as bulk plants -
which  also receive their products by  tank or rail car.  In the
vapor  balance system, vapors displaced from  the cargo tanks
during product loading are collected  in a vapor header on the
                               285
-------
                    VAPOR RETURN LINE
NJ
00
                                                                                 J'
VAPOR FRLt
AIR VENTED
   TO
ATMOSPHERE
                                                                             VAPOR

                                                                            RECOVERY

                                                                              UNIT
    RECOVERED
      LIQUID
   	PRODUCT
   "RETURNED
    TO STORAGE
                           PRODUCT FROM—
                          LOADING TERMINAL
                           STORAGF. TANK
                      Figure  4.6-7.  Tank  Truck Loading With Vapor Recovery.
-------
cargo carrier and conveyed to a vapor recovery unit.  The recov-
ered liquid product is returned to storage.  This "balanced " ex-
change occurs because the volume of displaced vapors is approxi-
mately equal to the volume of liquid cargo transferred.  When a
cargo carrier arrives to refill the terminal storage tanks, it
in turn applies the balance system, and exchanges vapors from
the storage tank for unloaded cargo.  The control efficiency of
the balance system has been demonstrated to range from 90 to 100
percent.l9

4.6.3.3   Energy, Cost, and Environmental Impact of Controls

          The estimated costs associated with the control methods
discussed in the previous section are-'listed in Table 4.6-3.  A
comparison of vapor recovery "systems to thermal oxidizers shows
lower capital cast for the thermal oxidizers.  The combustion
devices have higher operating costs, however, because there are
no product recovery credits.  As fuel..costs increase, disposal
methods will continue to become even less attractive than re-
covery methods for bulk plants with a high throughput.  For
plants with a low throughput, however, incineration may still be
the most attractive alternative.

          Energy requirements for loading modifications are
minimal.  The energy required to operate a vapor recovery unit
is estimated to be 2 MJ/m3  (2 kWh/103 gal).20  This requirement
is more than offset by the energy content of the recovered pro-
duct.

          Secondary pollutants resulting from the application
of these controls are virtually non-existent.  If the vapor re-
covery  system is a condensation unit, a very small waste water
stream  is generated by condensation of water vapor  along with
                                287
-------
              TABLE 4.6-3.  ESTIMATED COSTS FOR VOLATILE ORGANIC CONTROL TECHNIQUES  AT
                              TANK TRUCK AND RAIL CAR TERMINALS AND BULK PLANTS21 '" 'a
                                           Facility Size
                                             and Type
                    Installed
                     Capital
                      Cost
 Direct
Operating
  Cost
Capital
 Cost
   Net
Annualized
   Cost
(Including
 Gasoline
  Credit)
      Vapor Recovery  System
950 as/day  (2.1xl05  $185,000
gal/day)  tank truck
or rail car  terminal
 $10,500
$31,500
 $20,600
00
00
      Vapor balance  system
      Thermal oxidizers
75.7 ra'/day  20x103     47,000
gal/day)  bulk plant
950 m3/day  (2.1xl05   140,000
gal/day)  tank truck
or rail car terminal
   6,000
 23,800
  29,800
       Costs are  based on several assumptions. "See original reference for bases.
-------
the hydrocarbon vapors.  This liquid stream must be treated in
a wastewater treatment plant.
                                                                t
4.6.4     Gasoline Service Stations

          Emissions of volatile organics are produced at gaso-
line service stations from two operations, bulk gasoline drops
and motor vehicle refueling.  Quantities of emissions and con-
trol methods for each operation are discussed in the following
sections.  Table 4.6-4 summarizes emission factors for losses
produced by operations at service stations.

4.6.4.1   Emission Characteristics

          Bulk Gasoline Drops

          A major source of organic vapor emissions is the fil-
ling of underground gasoline storage tanks at service stations.
.Gasoline is delivered to service stations in 4-60m3 (1000-16000
gal) tank trucks.  Emissions are generated when hydrocarbon vapors
in the underground storage tank are displaced to the atmosphere by
gasoline loaded into the tank!"  The quantity of emissions depends
on several variables including the size and length of the fill
pipe, the method of filling, the tank configuration, and gaso-
line properties such as temperature, vapor pressure, and compo-
sition.  An average emission rate for submerged filling is 0.88
kg/103 liter (7.3 lb/103 gallons) of gasoline transferred.  The
emission rate for splash filling is 1.38 kg/103 liter (11.5 lb/103
gallons) of transferred gasoline.21*

          Emissions from underground tank filling operations at
service stations can be reduced by the use of the vapor balance
system illustrated in Figure 4.6-6 and described in Section 4.6.3.1.
                              289
-------
      TABLE 4,6-4.   ORGANIC VAPOR EMISSIONS  FROM
                      GASOLINE SERVICE  STATION OPERATIONS23
                                      Emission Factors
      Emission Source            kg/103 liter         /lb/103  gal\
                                 throughput          \thrcmghput/
Filling Underground Tank
  Submerged  filling                  0.88                 (7.3)
  Splash filling                     1.38                (11.5)
  Balanced submerged filling     ,    0.04                 (0.3)

Underground  Tank Breathing           0.12                 (1)

Vehicle Refueling Operations
  Displacement  losses
    (uncontrolled)                   1.08                 (9)
  Displacement  losses                0.11                 (0.9)
    (controlled)
 .^Spillage                           0.084                (0.7)
                            290
-------
The control efficiency of the balance system ranges from 93 to
100 percent.  Hydrocarbon emissions from underground tank filling
operations at a service station employing the vapor balance sys-
tem and submerged filling are not expected to exceed 0.04 kg/103
liter (0.3 lb/103 gallons) of transferred gasoline.

          A second source of hydrocarbon emissions from service
stations is underground tank breathing.  Breathing losses occur
daily due to gasoline evaporation from changes in temperature
and barometric pressure.  (The type of service station operation
also has a large impact on breathing losses.)  An average breath-
ing emission rate is 0.12 kg/103 liter (1 lb/103 gallons) through-
put.  Currently, no controls are being installed on underground
storage tanks for1 the control of tank breathing losses.25

          Mo tor Vehicle Re f ueling

          An additional source of organic vapor emissions at
service stations is vehicle refueling operations.  Vehicle re-
fueling emissions occur from spills and when vapors are dis-
placed from the automobile tank by dispensed gasoline.  The
quantity of displaced vapors is dependent- on gasoline tempera-
ture, auto tank temperature, true vapor pressure of the gasoline,
and dispensing-rates .  Al-though- .several correlations have been
developed to estimate losses due to displaced vapors, significant
controversy exists concerning these correlations.  It is esti-
mated that the emissions  due to vapors displaced during vehicle
refueling average, 1.08 kg/103 liter  (9 lb/103 gallons) of dis-
pensed gasoline.  The quantity  of spillage loss is a function
of  the type of service station, vehicle tank configuration, op-
erator technique, and operation discomfort indices.  An average
spillage  loss is 0.08 kg/103 liter  (0.7 lb/103 gallons) of dis-
pensed gasoline.26
-------
4.6.4.2   Control Technology

          Control methods for the emissions produced by filling
of underground storage tanks, referred to as Stage I control,
are similar to control technology for tank truck and tank car
unloadings at bulk stations.  Section 4.6.3.2 contains informa-
tion on such systems.  Stage II controls or control methods for
vehicle refueling are based on conveying the vapors displaced
from the vehicle fuel tank to the underground storage tank.
Figure 4.6-8 shows the hose, nozzle, and piping configuration
employed.  The three types of Stage II controls are "balance"
vapor control system, "vacuum assist" vapor control system, and a
hybrid of these two.  In the "balance" system, vapors are con-
veyed by natural pressure differentials established during re-
fueling.  A vacuum pump assists the flow of vapors in the "vacuum
assist" system.  In this sytem an additional process  (refriger-
ation or adsorption) may be utilized to increase efficiencies.
The vapors in a hybrid system are assisted by a means to create
a vacuum, usually an aspirator.  The overall efficiency of vapor
control systems for vehicle refueling emissions is estimated to
be 88 to 92 percent.27

4.6.4.3   Energy, Cast, and Eny,ironmen.ta 1 Impact of Controls

          Average installed costs for retrofitting an existing
service station with a vapor balance system are estimated to be
$6000 for a 120 m3 per month (32,000 gal per mo.) station.  Vacuum
assist units cost an additional estimated $7,500.  These costs
are in 1975 dollars.28  A study done for API'in 1973 estimated
a cost of $2,565 for equipping a typical new station pumping
95 m3/mo (25,000 gal/mo) with vapor balance systems.29  However,
more current estimates are probably near $3,000.  The differences
between retrofit and new facility costs are largely due to con-
crete and blacktop which must be raised and repoured.30  Operat-
ing costs and energy requirements are minimal,31 and  there are no
secondary environmental pollutants involved.
-------
                       RETURNED
                                              SERVICE
                                              STATION
                                              PUMP
{^	DISPENSED .QASOUNE
                                                                "1
Figure  4.6-8.   Automobile refueling vapor-recovery  system;
                              293
-------
    4.6.5      References

    1.   Urban,  C.  M.  and K.  J.  Springer.   Study of  Exhaust Emissions
        From Natural Gas Pipeline Compressor Engines.   Southwest
        Research Institute.   San Antonio,  Texas.  Prepared for Ameri-
        can Gas Association.   Arlington,  VA.  February 1975.   As
        cited in Environmental Protection Agency.   Compilation of
        Air Pollutant Emission Factors,  2nd Ed. -Research Triangle
        Park, N.C.  AP-42.   1973.

    2 .   Reference 1..

    3.   Dietzmann, H. E. and K. J. Springer.  Exhaust Emissions From
        Piston and Gas Turbine Engines Used in Natural Gas Trans-
        mission.  Southwest Research Institute.  San Antonio, Texas.
        Prepared for American Gas Association.  Arlington, VA.
        January 1974.  As cited in EPA,  AP-42.  February, 1975.

    4.   Burklin, Clinton E., et al.  Revision of Evaporation Hydro-
        carbon Emission Factors.  Radian Corporation.  Austin, Texas.
        August 1976.

    5.   Burklin, Clinton E., et al.  Background Information on Hy-
        drocarbon Emissions from Marine Terminal Operations.  2 Vols.
        Radian Corporation.   Austin, Texas.  December 1976.

    6.   Burklin, August 1976.  Reference  4.

  7-9.   Burklin, December 1976.  Reference 5.

10-13.   Burklin, C. E., et al.  Development of National and Regional
        Background Information on Hydrocarbon Emissions from Loading
        and Unloading Gasoline and Crude Oil on Ships and Barges.
        Radian Corporation, Austin, Texas.  July 1977.

                                   294
-------
   14.   Burklin,  C.  E., et al.  Background Information on Hydrocar-
        bon Emissions from Marine Terminal Operations,  EPA Project
        No. -68-02-1319., Task 56.  Radian Corporation, Austin, Texas.
        November 1976.

15-16.   Reference 4.

   17,   Control of Hydrocarbons from Tank Truck Gasoline Loading
        Terminals.   U.S. ..Environmental Protection Agency, Research
       •-Triangle Park, S:G.  October 1977.

 .,..18.   Refer-eftce 10.

   19.   Compliance Analysis of Small Plants.  EPA Contract No.
        68-01-3156,  Task 17.  October 1976.

   20.   Burklin,  C.E., et al.  Study to Support Standards of Per-
        formance for New Sources in the Gasoline Marketing Industry,
        Vol." 1.  EPA Contract No. 68-02-1319, Task 7.  Radian Cor-
        poration, Austin, Texas.  December 1974,

   21.   EPA Communication with Industry as cited in Control of Hy-
        drocarbons from Tank Truck Gasoline Loading Terminals. Draft
        Document...  Research Trinagle Park, N.C.  May  1977. •. •••••-

   22.   Reference 19.

   23.   Reference 4.

24-25.   Burklin, C.E., et al.  Study of Vapor Control Methods for
        Gasoline Marketing Operations.  2 Vols.  Radian Corporation,
        Austin, Texas.  May 1975.
                                   295
-------
   26.   Scott Research Laboratories, Inc.  Mathematical Expressions
        Relating Evaporative Emissions from Motor Vehicles to Gaso-
        line Volatility, Summary Report.  Plumsteadville, PA.  API
        Publication 4077.   March 1971.

   27.   Reference 24

   28.   Burklin, C.E., et al.  Cost Effectiveness of Hydrocarbon
        Vapor Emission Reduction Methods for Vehicle Refueling Op-
        erations at Service Stations.   Radian Corporation, Austin,
        Texas.   October 1975.

   29.   Refinery Management Services Co., Cost Effectiveness of
        Methods to Control Vehicle Refueling -Emissions..  API Pro-
        ject No. EF-14.  Phase I Interim Report.  Pasadena, CA.
        April 1973.

30-31.   Scott Research Laboratories, Inc.  Performance of Service
        Station Vapor Control Concepts, Interim Report No. CEA-8.
        San Bernardino, CA.  June 1974.
                                  296
-------
4.7       Polymers

          Approximately 22 Tg (48 x 109 Ibs) of polymers are
produced annually for use in plastics, adhesives,  foams, and
other products.  Total organic emissions from the  U.S. polymer
industry in 1976 amounted to over 235 Gg (517 x 106 Ibs).   Re-
cent legislation should reduce emissions to approximately 154 Gg
(338 x 106 Ibs) per year.1 Organic emissions include monomer,
processing chemicals, and additives.  Many of these compounds,
such as vinyl chloride and phosgene,/pose severe health hazards,
while others are photochemically reactive.

          As indicated in Table 4.7-1, the three largest volume
polymers are polyvinyl chloride, polyethylene, and polystyrene.
The discussion in this section is limited to the production and
fabrication of the three largest volume products.   Additional
process and emission information is available for the polymer
industry.2

4.7.1     Manufacturing Processes

4.7.1.1   Suspension Polymerization

          Suspension polymerization is used to manufacture both
polyvinyl chloride (PVC) and polystyrene.  Figure 4.7-1 is a
simplified flowsheet for this process.

          In suspension polymerization the monomer  (vinyl
chloride or styrene), comonomer, initiators, catalyst, water,
and suspending agents are mixed in a  batch reactor.   The 'reactor
volume..averages 11,000 to 23,000 liters  (3,000-6,000  gallons)."
The reactor is-.lined with glass or stainless steel  and jacketed
to provide steam heat or water cooling.  The operating  tempera-
ture is 50°C (120°F) for PVC and 90-130°C  (195-265°F) for
                               297
-------
TABLE 4,7-1.   LARGE VOLUME PRODUCTS OF THE
      PLASTICS AND RESINS INDUSTRY3
1975
Tg (billion Ibs)
THERMOPLASTIC RESINS
polyethylene, low density
styrene and copolymers
poly (vinyl chloride) and copolymers
polyethylene, high density
polypropylene and copolymers
THERMOSETTING RESINS
phenolic and other tar acids
polyesters (unsaturated)
urea resins
epoxies (unmodified)
raelamine resins

2
1
1
1
0

0
0
0
0
0

.15
.82
.65
.11
.86

.43
.38
.31
.09
.055

(4
(4
(3
(2
(1

(1
(0
(0
(0
(0

.74)
.01)
.64)
.45)
.90)

.05)
.83)
.69)
.20)
.12)
1974
Tg (billion Ibs)

2.
2.
2.
1.
- 1.

0.
0.
0.
0.
0.

69
15
20
2.9.
02

608
41
38
11
073

(5
(4
(4
(2
(2

(1
(0
(0
(0
(0

.93)
.74)
.85)
.84)
.25)

.34)
.91)
.84)
.25)
.16)
                    298
-------
                        MONOMER RtCVCLE
VO
             CO MONOMER -

— MP
	 ^
REACTOR
VENT
REACTOR



^
4OHOMEF
8TRIPPEK
                                                             •-WASrEWATER
        Figure 4.7-1.   Simplified flow  diagram for the suspension polymerization process
-------
styrene.  Polymerization is carried out under continuous agi-
tation at high pressure (1 MPa or 150 psi for PVC).   Batch pro-
cessing times of approximately 6 hours are required to achieve
85-90% completion.5  The resultant slurry is transferred to
a stripper where the residual monomer is separated from the
polymer by heat and/or vacuum.  After condensation the recovered
monomer is returned to the storage tank.  After stripping, the
polymer is transferred to a blend tank where slurries from
several different reactors are mixed to insure a uniform product.
This mixture is then centrifuged, and the wet polymer is dried
in a hot-air rotary dryer.6  The dried polymer particles are
finally collected, bagged, and sent to product storage.

4.7.1.2   Emulsion Polymerization

          The emulsion polymerization process is very similar
to the suspension polymerization process and is also used to pro-
duce PVC and polystyrene.  Figure 4.7-2 is a simplified flow-
sheet for the process.  The major difference is that the emulsion
process produces both liquid latex and dried resin products.
Resin particles from emulsion polymerization are smaller, but
the polymer is of higher molecular weight.  For dried resin, a
spray dryer is used instead of a rotary dryer to insure a uni-
formly small particle size.

4.7.1.3   Mass Addition Polymerization

          Mass addition polymerization is used to produce
polystyrene and PVC.  Both multistage batch operations and
continuous processes are employed.  A simplified flowsheet is
shown in Figure 4.7-3 for a two-step process.  Batch operations
produce seed polymer in a pre-polymerization reactor (pre-po)
from liquid monomer and very active initiators.  No water is
added.  The reaction is carried out at 40-70°C (104-158°F)
                              300
-------
UJ
'•-' MOHOMER - - - - ~«J
|_l
CO MOKOUI A - 	 	 „ 	 *»
*ooiTt»ta • 	 — — - — »•
H€AC
I **'
»*VCH
fWACTOM

ton
IT

•TMIVEN
I KMT
WMOUC;
arnn-Pin
SLURRY
; ILIND
TANK
t VENT

DntfR

SOLID
MHT.CU8

VAPORS
raooucT
COLIECTIOH.
HOLOINO.
BAOOWd.
AW
                                              POlVMfR
Figure 4.7-2,  Simplified flow diagram for emulsion polymerization process
-------
                                                  MONOMER RECYCLE
MONOMER
INITIATOR
      Figure 4.7-3.  Simplified flow diagram for mass  addition polymerization.
-------
and 0.48-1.2.MPa (70-170 psi)7 for P?C and 90-200°C (195-3908F)
for polystyrene.8  Monomer conversion is only 7-127*.  In the
second step the slurry is transferred to a larger horizontal
reactor (autoclave) where monomer and initiator are added.  The
reaction temperature and pressure are similar to those in the pre-
polymerization reactor, but agitation is much stronger.  After
the polymerization reaction is 85 to 90 percent complete, the
slurry is stripped of remaining monomer, screened, and bagged.
No drying step is necessary, since water is not used in the
process.  The mass addition autoclave must be cleaned after
every batch, but the pre-po does not require frequent cleaning.

4.7.1.4   Hi&h Pressure Mass Add11ion

          High pressure mass addition is used exclusively to
prcfdtrce low density polyethylene.  A very simplified flowsheet"""
of the process is found in Figure 4,7-4.  Ethylene, initiator,
and other additives are combined in a kettle or tubular-type
high pressure reactor.  Reaction temperatures may reach 350°C
(598*F).  The reactions are carried out at very high pressures,
0.1-0,3 GPa (15,000-45,000 psi),9

          After polymerization, the ethylene-polyethylene mix-
ture is treated "in a flash tank where solid resin is separated
from the raw,material.  Ethylene vapors are purified and recycled
as reactor feed.  Tars, waxes, and oils are also separated and
sent to disposal.  The solid polyethylene is then extruded and
devolatilized.  Finally, it is pelletized and packaged for
marketing.
                               303
-------
                                TARS,WAXES.* OILS
                                                   ETHYLENE
                                                   RECYCLE
      ETHYLENE
      INITIATORS
        AND
      MODIFIERS
                                                                EXTPUonn
                                                                 VENT
                                                       ^_ I EXTRUSION AND
                                                         DEVOLATILIZATION
                                                                         SOLID
                                                                       POLYETHYLENE
                                                   POLYMER
Figure 4.7-4.   Simplified flow  diagram of high pressure mass addition process for
                 polyethylene polymerization.
-------
4.7.1.5   Solution Polymerization

          This manufacturing process is used  to produce poly-
styrene, polyethylene, and  small amounts of PVC and  its co-polyme
polyvinyl acetate.  Figure  4.7-5 is a  simplified  flow  sheet  of  th
process.  The reactor is charged with  the  co-monomer and  a sol-
vent, usually n-butane for  PVC  and ethylbenzene or toluene for
polystyrene.  After heating to  40°C  (1Q4°F),  polymerization  be-
gins and the resin precipitates.10  Slurry is drawn  off and
filtered, and the resin is  dried by flash  evaporation.  The
resin is -very pure because  emulsifiers and additives are  not -"	
required.  Solvent is recovered from the evaporator  and the
drying and devplatizing steps.  Recovered  solvent is recycled.-

4. 7,. 1. 6   Particle Form-_Polyinerization    ".   '.....-

          The particle form process  (Phillips Particle Form
Polymerization Process) is  used mainly to  produce high density
polyethylene in a continuous process.  Figure 4.7-6  is a  flow
diagram for the process.  The reaction is  carried out  in  stirred
or loop-type reactors.  The monomer and co-monomer are pretreated
to remove catalyst poisons  such as CO, 02, and H20.  Raw  materials
are dissolved in pentane or cyclohexane before addition to the
..reactor. *' An activated catalyst is also added.  The  polymeriza-
tion-  reaction occurs  at around  140°C  (220QF)  and  3 MPa (450  _ psi)

          Slurry from the reactor is treated  in a flash drum
where solvent, ethylene, waxes, and light  gases are  removed.
Both solvent and ethylene are recycled after  purification.   The
catalyst remains in the resin.  • The purified  polymer is dried,
extruded, pelletized, and packaged.
                              305
-------
                                              MOHOHIH RECYCLE
CO
O
                     MOMOWEfl
                 SDIVINT UAKC-UP
          Figure  4.7-5.   Simplified :flow diagram for  the solution polymerization process
                                                              -*-,
-------
o
             CATALYST
                                                                     ,EXTRUDER
                                                                     f WNT
                                                                           FOLVMEft
            Figure 4.7-6.   Simplified flow diagram for particle form polymerization.
-------
4.7.2     Process Emissions

4.7.2.1   Polyvinyl Chloride

          The three main processes for commerical polymerization
of PVC are:  1) suspension process (78%), 2) emulsion process
(137o) and 3) mass addition process (67o) .   A small amount of PVC
is produced by the solution process (37.).12

          Vinyl chloride monomer (VCM) emissions from all the
polymerization processes are listed in Table 4.7-2.  Because the
suspension and emulsion processes are similar, emission sources
are virtually the same.  Emission rates /are comparable except
that the residual VCM in -the emulsion process spray drying
causes higher VCM emissions than the suspension process spray
drying.  The spray dryer may emit up to  857o of the total emis-
sions from emulsion polymerization.13

          One source estimates/ that 12 to 46 percent of total
VCM suspension process emissions come from fugitive sources, 3570
from process vents (dryer, /air conveyor, storage bin, and cen-
trifuge) , and 11% from blend tanks.1"  The data for fugitive
emissions include losses7incurred from the following operations:
1) loading, unloading, sampling and storage of VCM, *2) leaks from
pumps, compressors, valves, and agitators, 3) pipe and equipment
flanges  and manhole cover  seals, 4) opening equipment for
inspection and maintenance, 5) sampling  for laboratory analysis,
6) VCM dissolved in process water exposed to the atmosphere,
and 7) manual venting of equipment.17

          VCM emissions occur each time  the reactor is opened
for cleaning.  Scale on the walls of the reactor must be manually
removed  every 1-3 days for suspension or emulsion processes  and
                               308
-------
               TABLE 4.7-2.
CO
o
VINYL CHLORIDE MONOMER EMISSION FROM PVC PRODUCTION
(kg/100 kg PVG, lb/100 Ib PVC,)a'b'l5'l 6
Source
Fugitive Emissions - Total
Polymerization reaction
Polymer isolation .;
Other
Keactor Opening Loss
Reactor Safety Valve Vents
Venting Losses:
Stripper
Monomer Recovery
Blend Tanks
Centrifuge
Collector Losses:
Dryer exhaust '•*
Silo storage
Bagging
Bulk Loading '
Process Water
TOTAL
Emulsion
Polymer izat ion
1.13
0.15
0.22
1.23
0.50
0.34
2.41
0.025
6.0.1.
Suspension
Polymerization
1.50
0.09a
1.1 2a
0.29
0.14
0.20
0.32
0.48
0.42
0.13
0.70
0.025
3.92
Mass Addition
Polymerization
0.48
0.08
0.10
1.50
0.23
0.011
2.40
Solution
Polymerization
0.03
0.50
0.06
0.05
0.31
0.83
0.002
1.78
        Emission data from reference 16,  all other data are from reference 15,

        Emission factors  were  derived by  EPA by averaging emission factors given by individual
        PVC producers in  response to a May 30,  1974,  request for information made by OAQPS  un-
        der authority of  Section 114 of the Clean Air Act.
-------
after every batch in mass addition processes.   Most VCM is re-
moved by vacuum evacuation but residual gases  are released to the
atmosphere during purging with steam or air when the reactor is
opened.18

           The reactor safety valve vents produce intermittant
emissions of 5 to 15 minutes duration.  Safety vent gases can
have very high concentrations of VCM.  These losses occur when
the polymerization reaction "runs away" due to equipment failure,
power failure, or operator error.  The reactor must be vented to
prevent damage from over-pressuring.  Emissions from this source
can vary from 0.04-0.4 kg VCM/100 kg PVC (0.04-0.4 Ib VCM/100 Ib
PVC).19

           Organics are also released at vents on the stripper,
blend tank, centrifuge, and dryer.  Emissions from the product
collection and holding bins and bagging operations are in the
form of VCM and particulate PVC.  VCM evaporates from centrifuge
and cleaning waters when they are exposed to the atmosphere.

           When a gasholder and scrubbing system is used to con-
trol reactor emissions, the composition of the vented organic
vapors is changed.20  Table 4.7-3 lists typical composition of
the residue gas after absorption scrubbing.

     TABLE 4.7-3.  STACK GAS COMPOSITION AFTER ABSORPTION
                   OF ORGANIC EMISSIONS21
                         kg Moles/Day             Ib Moles/Day
Acetylene                  0.000089                  0.00004
Butadiene                  0.0014                    0.00063
Methyl Chloride            0.0014                    0.00063
Vinyl Chloride            10.0                       4.5
                                310
-------
4.7.2.2    Polyethylene

           Polyethylene is produced in two forms,  high density
polyethylene (HDPE) and low density polyethylene (LDPE).   About
one-third of total polyethylene production is HDPE.   It is manu-
factured by solution, particle form, and vapor-phase processes.
However, the particle form process produces more resin than the
other two methods combined.22  LDPE is manufactured by high
pressure mass addition.

           Emissions from the particle form and high pressure
mass addition processes are summarized in Table 4.7-4.  Fugitive
emissions account for the majority of total process emissions.
An industry-wide survey23 reported fugitive losses of solvent
and monomer to be 3 Gg/year (7 x 106 Ibs/year) for HDPE.   Losses
from solvent recovery, monomer recovery, and polymer stripping
consist of the light and heavy ends from the purification process
Materials handling losses arise from the pneumatic conveying of
finished and semi-finished polyethylene.  Emissions from all
sources are primarily ethylene, although in the particle form
process, some solvent losses  (pentane, cyclohexane) may occur.

  TABLE' 4.7-4.  VOLATILE ORGANIC EMISSIONS FROM THE MANUFACTURE
                OF TWO FORMS  OF POLYETHYLENE2"
                               High Density        Low Density
                               Polyethylene        Polyethylene
                            g/kg  (lb/1000 Ib)   g/kg  (lb/1000  Ib)
	Product	Product	
Fugitive                            20                  10
Materials Handling                   3                   5
Solvent and Monomer  Recovery         2                   1
Polymer Stripping                    9                 '
                                    34                  16
                               311
-------
4.7.2.3   Polystyrene

          Most polystyrene (PS) is produced by solution polym-
erization and suspension polymerization.   Smaller amounts are
produced by emulsion and mass addition polymerization.   The
first process produces a purer resin although the second pro-
cess provides a more uniform product.  Polystyrene is produced
as the homopolymer and various copolymers such as ABS,  SAN, and
high impact PS.  Figure 4.7-7 shows how these compounds are
related.

          Crystal Polystyrene + Acrylonitrile •*• San
                   +                             +
                Rubber                         Rubber
                   +                             4-
              High Impact
              Polystyrene   +   Acrylonitrile -»• ABS

       Figure 4.7-7.  Relationships Between Polystyrene
                      and its Co-Polymers25

          Styrene is the main component of gaseous emissions
from polystyrene production.  Monomer loss occurs during feed
preparation, from reactor venting, and from the solvent re-
covery system (see Table 4.7-5).  Fugitive emissions are re-
portedly negligible, probably because the processes are carried
out at low pressure.27  Other emissions reported include small
amounts of pentane and ethyl benzene.
                              312
-------
  TABLE 4.7-5.  STYRENE EMISSIONS FROM POLYSTYRENE PRODUCTION
                                                             2 6

Feed Preparation
Reactor Vent
Solvent Recovery
Fugitive
Conveying Operations

Solution Process
g/kg (Ib 1000 Ib)
Styrene
.65
3.34
1.84
	
_J.
5.93
Suspension Process
g/kg (Ib 1000 Ib)
Stvrene
	
3.34
	
	
.1 .
3.44






4.7.2.4   Fabrication and Adhesives Production

         . Extrujsion atul_Molding

          Emissions from plastics extrusion and molding processes
are usually composed of gaseous monomer, additives, and solvent.
The amount of material emitted depends on the plastic, tempera-
ture, previous processing history, and length of storage.  If
extrusion is carried out at the polymer production plant, emis-
sion rates will be comparable to those rates given earlier. -
Secondary extrusion and molding rates will vary from one process
and material to another.

          Adhesives

          Polystyrene and polyvinyl chloride resins are widely
used in adhesive manufacture.  Synthetic adhesives may be of two
types, thermoplastic and thernosetting, although PVC and PS are
used only in the former.  Emissions consist of the solvent used
to dissolve the resin.  Organic solvents commonly used in adhe-
sives are methylethyl ketone, toluene, benzene, and naptha."5
Table 4.7-6 lists estimated  organic solvent usage  for various  ad-
hesive applications.
-------
TABLE A.7-6,
ESTIMATED ORGANIC SOLVENT USAGE IN ADHESIVES
APPLICATIONS2'9
Application
Flooring, tile, wall covering
Other construction
Aircraft assembly
Automobile assembly
Plywood and veneer
Particle board
Furniture assembly
Other wood products
Textile products
Footwear
Pressure sensitive tapes and labels
Gummed tapes and labels
Packaging laminates
Other paper products
Glass ins'ulation
Abrasive products
Printing and publishing
Rubber products
Tires
Other
Organic Solvent
(metric tons /year)
11,000
14,000
900
20,000
2,000*
1,300*
7 , 300
11,800
2,000
7,300
263,000
5,700
5,800
14,000
13,000
5,900
6,300
21,500
1,000
67,600
Total 481,400
Year
1973
1966
1973
1973
1973
1973
1973
1973
1973
1973
1974
1973
1973
1973
1973
1973
1973
1973
1973
1973 .,
\
*EPA Estimate
                               314
-------
4.7.3     Control Technology

          A summary of control devices and emission levels for
polyvinyl chloride is given in Table 4.7-7.  Applicable control
techniques include carbon adsorption, resin adsorption, incinera-
tion, absorption, refrigeration/condensation, vacuum stripping,
and good housekeeping.  The control of fugitive emissions is de-
scribed in Section 4.1.  A detailed description can be found in
the Standard Support and Environmental Impact Statement for
Vinyl Chloride ,  October 1975. 31

         - .Safety relief valve discharges can be controlled or
prevented by venting the reaction mixture to a gasholder large
enough to hold an entire batch of VCM, by injecting an inhibi-
tor  ("shortstop") to prevent polymerization, flaring, a" coo-Ling
water jacket, or a power back-up system.  Losses of monomer from
reactor cleaning can be reduced by recipe reformulation, re-
designing reactors, or applying a coating to the interior of the
reactor to reduce scale formation.  In new plants the frequency
of reactor openings can be reduced to once every 80-90 batches.32
VCM emissions from process .and cleaning waters .can be prevented
by stripping, these waste waters prior to release into plant
treatment"ponds.

          Control devices currently used in polyethylene pro-
duction are  flares and incinerators.  Many of the control de-
vices used in PVC production could also be applied to poly-
ethylene production.

          Emissions from polystyrene production are  controlled
by flaring and through refrigeration/condensation vapor re-
covery.  Also, it is possible to  scrub  styrene storage  tanks
using No. 2  fuel oil.33  Control  techniques  described  for PVC
production are applicable to polystyrene production when  che
same manufacturing methods are used.
                                315
-------
TABLE 4.7-7.   CONTROL  TECHNIQUES FOR VCM EMISSIONS
                 FROM PVC PRODUCTION30
Emission Source
Fugitive Total
1. Transfer Opera-
tions: loading
& unloading
2. Safety relief
valve leaks &
discharges
3. Pumps, compres-
sors, & agita-
tion seals
4. Laboratory
sampling
5. Equipment
opening
6. In process
wastewater
7. Leaks at
flanges, seals

Safety relief valve

Reactor opening
losses
Monomer recovery
system

Slurry blend tanks



Centrifuge



Dryers


Storage silos



Uncontrolled
Emission Rate
kg VCM
100 kg PVC
. Ib VCM .
Control Techni«tue 1100 Ib PVC;
1.53
Purge £0 control
device

Rupture disks
flare

Double mechanical
seals

Purge sample flasks
back to process
Displace gas to
control device
Strip VCM & vent
to control device
Multipoint fixed
& portable moni-
toring devices
Short stop, Q j
gasholder
Displace gas to ' n .,
gasholder 0'*6
Reduce inert s 0.48
Solvent absorber
Carbon adsorber
Improved stripping 0.42
Carbon adsorption
Solvent absorption
Incineration
Improved stripping 0.13
Carbon adsorption
Solvent absorption
Incineration
Improved stripping 0.63
Carbon adsorption
Incineration
Improved stripping 0.07
Carbon adsorption
Incineration
Silo stripping
Achievable
Emission Rate
kg VCM
100 kg PVC
, Ib VCM >
lioo ib pvr
0.16




















0.001
0.001
0.001
0.001
0.013
0
0
0
0.004
0
0
0
0.02
0.02
0.02
0.002
0.002
0.002
0.002
Control Devices include solvent absorbers, carbon adsorption, or incineration.
Each can control emissions to 10 ppm.
                              316
-------
4.7.4     Energy, Cost, and Environmental Impact of Controls

          Energy, cost, and environmental impact of existing
controls for polymer production are discussed in Sections 4.1
and 3.0.

4.7.5     References

1.   Shumaker, J. L. Polymer Industry Study.  Internal EPA
     Report.,to D, R. Patrick, Chief, Chemical Manufacturing
     Section.-  May 10, 1977.

2.   Wilkins, G. E.  Chapter 10, Plastics and Resins  Industry.
     In:  Industrial Process Profiles for Environmental Use.
     Industrial Environmental Research Laboratory, 0"ffice of  ,
     Research and Development, U.S. 'Environmental'Protection
     Agency.  Cincinnati, Ohio.  EPA-600/2-77-023J.   February
     1977.  350 p.

3.   CfieEN's.Top 50 Chemical Products and Producers.   Chemical
     and Engineering News". 54(19) :  33-39, May  3, 1976.

4.   Standard "Support -and -Environmental Impact  Statement:
     Emission Standard for Vinyl Chloride.  Environmental
     Protection Agency.  Research Triangle Park, NC.  EPA-450/
     2-75-009.... October 1975.  536 p.

5.   Reference  4.

6.   Reference  2.                                        "
                                317
-------
    7.   Bellamy,  R.  G.  and W. A.  Schwartz.  Engineering and Cost
        Study of  Air Pollution  Control  for  the Petrochemical In-
        dustry, Volume  9:  Polyvinyl  Chloride Manufacture.  En-
        vironmental  Protection  Agency.  Research Triangle Park, NC.
        EPA-45/3-73-006-9.   July  1975.  102 p.

  8-9.   Reference 2.

   10.   Pervier,  J.  W.,  et al.  Survey  Reports on Atmospheric
        Emissions from  the Petrochemical  Industry,  Volumes III  and
        IV.   Environmental Protection Agency.  Research Triangle
        Park, NC. PB-245-629  and PB-245-630.  April  1974,

   11.   Reference 2.

   12.   Reference 4.

13-14.   Carpenter, B. H.  Vinyl Chloride - An Assessment  of Emis-
       . sions Control Techniques  and  Costs.  U.S. Environmental
        Protection Agency, Washington,  B.C.  EPA-650/2-74-097.
        September 1974.

   15.   EPA-Perived  Figures, Average  Emission  Factors Given  by
        Individual Polyvinyl Chloride Producers  in  Response  to
        May 30,  1974.  Request for Information Made by the Office
        of Air Quality  Planning and Standards  Under Authority  of
        Section 114  of  the  Clean  Air Act.  As  cited in Reference 4,

   16.   Reference 2.

17-18.   Reference 4.
                                 318
-------
   19.   Thirty-six Plantrs Reported this Emission. During Spring,
        1974, in Response to a Request for Information Under
        Section 114 of the 1970 Clean Air Act.  As cited in Re-
        ference 4.

20-21.   Bellisio, A. A.  U.S. Patent 3,807,138.  April 30, 1974.
        Assigned to GAF Corporation.  As cited in Pollution Control
        in the Plastics and Rubber Industry.  Marshall Sittig,
        Koyes Data Corporation, 1975.

   22.   Reference 2.

23-24... Reference 10.

   25.   McKenna, L, A. Polystyrene.  In:  Modern Plastics Enclclo-^'j
        pedia.  51(10A):  102-103, October 1974.

26-2.7.   Reference 10.

   28.   Environmental Protect ion-" Agency, "Compilation of Air Pol-
        lutant Emission Factors.  Second .Edition with Supplements.
        Office of Air Quality Planning and Standards.  Research
        Triangle Park, NC.  Publication Number AP-42,  February
        1976.  462 p.

   29,   Most numbers were estimated by Midwest Research  Institute
        under contract to EPA  (Contract No. 68-02-1399, Task  9).
        Estimates are'based, in most instances, on usage data-
    """'""contained in a private publication by Predicasts, Inc.,
        entitled, "Adhesives", May 29, 1975.

30-31.   .Reference 4.
                                319
-------
32.    Letter with Attachments from Ralph Ferrell, Conoco Chemi-
      cal Company, to Don R.  Goodwin,  EPA,  November 19,  1974.
      As cited in Reference 4.

33.    Styrene Removed by Wet Scrubbing.   We't Scrubber News.
      March 1977.
                              320
-------
4.8       Paint, Varnish, and Ink Manufacture

          Organic emissions from paint, varnish, and printing
ink manufacturing and methods of control are described in Sec-
tions 4.8.1 through 4.8.3.

4.8.1     Paint Manufacture

          Paint is defined as a pigmented liquid that is con-
verted to & relatively ropaque solid film after application as a
thin layer.1  Enamels are paints which form an especially smooth
and glossy film

          Paint manufacturing consists of the following
operations:

          1.  Mixing pigment with sufficient vehicle to
              make a paste of proper grinding consistency

          2.  Grinding the paste on a mill until aggregates
              are broken down.

          3.  Letting down (diluting) the ground paste with
          ''	thfe remaining materials            .'•••"

          4'. '"'Tinting to required color

          5. . .Testing                                       .- •

          6.  Straining, filling, and packaging.

          In some cases the mixing and grinding operations are
done in .one step.   Paint manufacturing is still largely a bacch
process because of the large number of raw materials and finished.
                                321
-------
products required.  Many of the products must be custom formulated
and processed.2

4.8.1.1   Emission Characteristics

          Volatile organic emissions from uncontrolled manufac-
turing equipment average 15 g/kg (30 Ib/ton) paint product.3  From
the study "Air Pollution Control Engineering and Cost Study of the
Paint and Varnish Industry, " Publication No. EPA-450/3-74-031,
June 1974, an average emission factor of 6 kg/m3 (0.05 Ib/gal) of
solvent-based paint was -used to calculate a volatile organic emis-
sion average of 4 g/kg (8 Ib/ton) of paint product.  The two
sources of volatile organic emissions in paint manufacturing are
grinding and thinning.  During grinding, heat is produced which
causes vaporization of certain ingredients.  In the thinning opera-
tion, vaporization of solvent occurs.  Thinning of premixed paint
pastes to the required consistency for application involves dilu-
tion with aliphatic or aromatic hydrocarbons, alcohols, ketones,
esters, and other highly volatile materials.1*  Because of the vola-
tility of most thinners, mixing must be done in totally enclosed
tanks to prevent solvent loss.  A small amount of pigment fines is
emitted from the mixing operation.

4.18.1.2  Control Technology

          The use of afterburners, condensers and/or absorbers
can eliminate 99% of the emissions from a source not using  these
controls.  One to two percent of the solvent is lost even under
well controlled conditions.5

4.8.1.3   Cost, Energy, and Environmental Impact of Controls

          The above control methods  are discussed in Section
3.0.
                                322
-------
4.8.2
Varnish Manufacture
          Varnish is an unpigmented surface coating composed  of
resins, oils,  thinners,  and driers.  Varnishes dry by evaporation
of the solvents  and oxidation and polymerization of the remaining
constituents.  Table 4.8-1 lists common raw materials used  in
varnish manufacture.
               TABLE 4.8-1.
                   RAW MATERIALS USED  IN
                   VARNISH MANUFACTURE5'7
     Oils
        Resins
Solvents fi> Thinners
    Dryers
Linseed Oil  Phenolics
Soybean Oil  Alkyd Acrylates
Tall Oil
Tung Oil
Castor Oil
Fish Oil
Coconut Oil  Copal
Oiticia Oil  Dammar
Other Oils
 Silicones
 Epoxies
 Polyurethanes
 Rosin
 Manila &..East India
Turpentine
Xylol
Toluol
Alcohols
Aromatic & Aliphatic
Naphthas
Dipentine
CO,-to-,' Pb,  & Zn-
Naphthenates
Resinates
Tallates
Lineoleates
           Oletnresinous varnishes  are the most common  and several
types  are produced.  They  are  all solutions of natural or syn-
thetic resins in a drying  oil  and a volatile solvent.   Oleo-
resinous  varnishes dry by  oxidation; oxidation and  condensation;
or  oxidation, condensation,  and polymerization.8  The other
major  type of varnish is spirit varnish, which consists of
alcohol solvents plus natural  or synthetic resins.  Little or
no  oil is added to spirit  varnish.   Shellac is the  most common
spirit varnish.   Spirit varnishes dry either by  evaporation or
by  evaporation and polymerization.
                               323
-------
          Other important types of varnishes have been developed
recently.  Alkyd resin varnish is a solution of alkyd resin (a
synthetic polyester co-reacted with a vegetable oil) in a vola-
tile solvent with added drier.  Asphalt varnish is a solution
of asphalt in a volatile solvent.  Lithograph varnish is used as
a vehicle in pigmented lithographing printing ink.

          The steps in varnish manufacturing include cooking,
thinning, mixing, filtering, storing and aging, testing, and
packaging.  The most important step in this process is cooking.
The cooking step performs many functions; some of the most
important ones are:

          1.  Bodying of natural and synthetic oils

          2.  Melting materials to accelerate solubility
              and reaction

          3.  Esterification of rosin, phthalic anhydride,
              maleic anhydride, or tall oil with a polyhydric
              alcohol such as glycerol or pentaerythritol

          4.  Isomerization to eliminate extreme reactivity
              in some oils during oxidation

          5.  Preparation of alkyd resins

          6.  Distillation and evaporation to remove
              undesirable constituents such as volatiles
              in resins.
                              324
-------
           Cooking  temperatures  in varnish  kettles  range from
 93  to  340°C  (200 to  650°F)  and  are usually maintained for 4 to
 16  hours.9  The average  batch starts  to  produce vapors at about
 175°C  (350°F); the rate  of  vaporization  increases  with tempera-
 ture and  reaches its maximum shortly  after the maximum processing
 temperature  is reached.10"11  Vapor emission continues as long  as
 heating is continued.  The  vaporization  rate decreases after the
 maximum is reached.

           Both open  and  closed  kettles are used for cooking var-
 nish,  although the trend is toward closed  kettles.  The open
 kettle is heated over .an open flame.   The  newer totally- enclosed
 kettle is set over or within, a  totally enclosed source of heat,
-The open  kettle allows vaporized material  to be emitted to the
 atmosphere unless  hoods  and ventilation  systems are provided
 to  conduct the vapors to a  control device.

 4.8.2.1    EmissionsCharacteristics

           Organic  emissions from varnish manufacture are pro-
 duced  from two operations,  cooking and thinning.  Table 4.8-2
 describes emis'sions  from these  two operations.  In.-addition to
 the air  contaminants listed in  Table  4.8-2, sulfur compounds
 "such as hydrogen  sulfide, butyl mercaptan, thiophene, and allyl
 sulfide  are  emitted  when tall  oil is  esterified with glycerine
 ami ,-pentaerythritol.16   Tall oil is the  third largest volume
 oil used  in  paint  and varnish  production (19.5 Gg or 43 x 10
    in 1973).17
                                325
-------
   TABLE 4.8-2.  EMISSIONS  SUMMARY FROM VARNISH MANUFACTURE
Source
Cooking of
Varnish
Dependent on
Raw Materials
Rate of temperature
application
Maximum temperature
reached
Type of
Emission1 3
Low melting
temperature
constituents of
natural gums,
synthetic acids
and rosins.
Compounds
Emitted1"' ls
Fatty acids
Aldehydes
Water vapor
Acrolein
Glycerol
Acetic acid
Formic acid
              Amount of stirring
              Extent of air blowing
              Length of cooking

 Thinning       Temperature of
               varnish
              Solvent used in
               thinning
              Method of addition
               of solvent and
               dryers
Thermal decomposi-
 tion and
 oxidation products

Volatile thinners
Turpentine
Xylol
Toluol.
Alcohols
Aromatic and
 aliphatic
 naphthas
Dipentine
          The  cooking operation is  the  greatest source of emis-
sions.  From 1 to 6 percent of the  raw  material is emitted dur-
ing the cooking operation.18   The type of varnish  being produced
influences not only the quality but also quantity of organic
emissions from both cooking and thinning.


          Many processes require  the addition of solvents and
thinners during the cooking process.  Because the temperature of
the cooker is  near the boiling point, solvent loss to  the atmos-
phere may be considerable, especially if open kettles  are used.
More solvent is vaporized if  a small amount of cold solvent  is
added to a large volume of hot varnish  than if a small amount of
hot varnish  is added to a large volume  of cold solvent.  Because
                               326
-------
of the high volatility of most solvents, most thinning opera-
tions must'b'e done in totally enclosed tanks to prevent large
losses.

          Losses of solvents during thinning could range from
5 to 50% of the total solvent added if open thinning tanks are
used.  Solvent emissions depend on the method of addition and
the length of time the thinned mixture is exposed to the air.i9
Most manufacturers use totally enclosed thinning tanks; there-
fore, the solvent losses generally amount to no more than 1 to
2% of the solvent used,20          -•

          Table 4.8-3 gives some emissions factors for volatile
organic emissions from one manufacturer of four varnishes.

           TABLE 4.8-3.  VOLATILE ORGANIC EMISSIONS
                         FROM VARNISH MANUFACTURE1*' 2 l" 2 s

                           -.'•-'•  Emission Factor
    Varnish Product               g /kg -Product   Ib/Tbn Product
    Bodying Oil                         20              40
    Oleo  Resinous                       75      •       150
    Alkyd                              80             160
    Acrylic                            10              20
      is considered of average quality, as explained  in  Introduc-
 tion of Reference 12.

4.8.2,2   CoTttrol_ Technology

          Integral condensers provide a considerable  degree  of
control for existing processes.  Other methods  of  controlling
emissions include scrubbers, absorbers, carbon adsorbers, after-
burners, reformulation of solvents , and sublimation.
                               327
-------
4.8.2.3   Cost, Energy, and Environmental Impact of Controls

          The above controls are discussed in Section 3.0.

4.8.3     Printing Ink Manufacture

          There are two major categories of printing ink.   Oil
and paste inks are used for letterpress and lithography.  Sol-
vent inks are used in flexography and rotogravure processes.
Solvent inks are similar to oil and paste inks, but they have
a very low viscosity and dry by evaporation of highly volatile
solvents.27

          Three general processes are used in the manufacture of
inks:  1) cooking and dyeing the vehicle (or "varnish"),
2) grinding a pigment into the vehicle and 3) replacing water
in the wet pigment pulp with an ink vehicle (flushing).  The
cooking process for ink vehicles is the same as for regular
varnish  cooking.  The vehicle is usually cooked in large kettles
at 93 to 315°C  (200 to 600°F) for an average of 8 to 12 hours.
Pigment  grinding is accomplished by three-roller or five-roller
vertical or horizontal mills.  Mixing of the pigment and vehicle
is done  in' dough mixers or large agitated tanks.2 8

4.8.3.1   Emission Characteristics

          Vehicle cooking is the largest source of ink manufac-
turing emissions.  At about 175°C  (350°F) the products begin  to
decompose, resulting in the emission of decomposition  products
from the cooking vessel.  Emissions continue throughout the
cooking  process with the maximum rate of emissions occurring just
after the maximum temperature has been reached.  Cooling the
varnish  components - resins, drying oils, petroleum oils, and
solvents produces odorous emissions.29
                              328
-------
          Emissions from the cooking of oleoresinous varnish
(resin plus varnish) include water vapor, fatty acids, glycerine,
acrolein, phenols, aldehydes, ketones,  terpene oils, terpenes,
and carbon dioxide.3 °

          The quantity, composition, and rate of volatile organic
emissions from ink manufacturing depend upon the cooking tempera--.
ture and time, the ingredients, the method of introducing addi-   .
tives, the rate of stirring, and the extent of air or inert gas
blowing.  An estimate of organic emissions, based on limited
information, is given in Table 4.8-4.                             :
                                                                 1
     TABLE 4.8-4.  VOLATILE ORGANIC EMISSIONS FROM VARNISH
                   COOKING IN PRINTING INK MANUFACTUREa.3l

                                      Emission Factors
   Varnish Cooking             g/kg ProductIbs/Ton Product
   General                          60                120         :
   Oils                             20                 40
   Oleoresinous                     75                150
   Alkyds                           80                160

S3       .*"*•"••••           - *         ,        ,"
 Data  is considered of poor quality, as  explained  in'Introduction
 of Reference  12.                                 '

4.8.3.2  .Control Technology

          Emissions from varnish  cooking can  be -reduced ..9Q7o by
the use of s-crubbers or condensers followed by afterburners.32'33
Emissions from solvent handling can be  controlled  with  condensers
and/or carbon  adsorption systems.

4.8.3.3   Cost, Energy,andEnvironmental Impact of Controls

          The  above controls  are  discussed i*i Section 3.0,
                               329
-------
  4.8.4     References

  1.   Payne, H.  F.  Organic Technology.   Vol.  II:   Pigments  and
      Pigmented  Coatings.   New York,  John Wiley and Sons,  Inc.,
      1961.  p. 984.   As cited in Control Techniques for Hydro-
      carbon and Organic Solvent Emissions from Stationary
      Sources.   National Air Pollution Control Administration,
      Publication AP-68.  March 1970.

  2.   Technology of Paints, Varnishes and Lacquers.  Martens,
      C.  R.  (ed.).   New York, Reinhold Publishing Corp., 1968.
      744 p.

  3.   Air Pollutant Emission factors.   Final Report.  Resources
      Research,  Inc. Reston, Va.  Prepared for National Air
      .Pollution  Control Administration.  Durham,  N.C.  Contract
      No. CPA-22-69-119.  April 1970.  As cited in Compilation
      of Air Pollutant Emission Factors, EPA, Publication AP-42.
      February 1976.

  4.   Stenburg,  R.  L.  Atmospheric Emissions from Paint and
      Varnish Operations, Part 1.  Paint Varn. Prod. 49_ (10):
      61-65, September 1959.  As cited in AP-68, March 1970.

  5.   Sittig, Marshall.  Environmental Sources and Emissions
      Handbook.   Park Ridge, New Jersey, Noyes Data Corporation,
      1975.  p.  369-370.

  6.   Fats and Oils.  Chemical Economics Handbook.  Menlo Park,
      California, Stanford Research Institute, November 1972.

7-8.   Protective and Decorative Coatings, Vol. III.  Matiello,
      J.  J.  (ed.).   London, John Wiley and Sons, Inc., 1943.
      p.  499-527.  As cited in AP-68, March 1970.
                                330
-------
    9.   Reference 1,

   10.   Reference 4.

   11.   Reference 7.

   12.   Environmental Protection Agency, Office of Air Quality
        Planning and Standards.  Compilation of Air Pollutant
        Emission Factors.  RTF, NC.  Publication AP-42.  February
        1976.

13-14.   Reference 7.

15-16.   Hydrodealkylatiian Processes.  Ind. 'and Eng. Chem. 54:...-2-8-3 3','
        February 1962.

   17.   Reference 6.    .

   18.   Reference 12.

   19,   Chatfield, H. W., Vapor Condensation.  In:  Varnish Manu-
        facture and Plant.  London, Leonard Hill, Ltd.,  1949.
        p. 157-218.  As  cited in AP-68, March 1970.

   20.   Reference 4.

   21.   Stenburg, R. L.  • Atmospheric Emissions from Paint and	  •
    • ' ••• Varnish Operations.  Paint Varn. Prod. p.  61-65  and  111-114,
        September 1959.  As cited in EPA, AP-42,  1976.          .  -•

   22.   Unpublished engineering estimates based -on plant visits
        in Washington, D.C,  Resources  Research,  Incorporated,
        Reston, Va.  October 1969.  As  cited in EPA,  AP-42,  1976.
                                  331.
-------
   23.  Chatfield, H. E. Varnish Cookers.   In:   Air Pollution En-
        gineering Manual.  Danielson, J.  A.  (ed.).   U.S.  DHEW,
        PHS, National Center for Air Pollution Control.   Cincinnati,
        Ohio.  Publication Number 999-AP-40.  1967.  p.  688-695.
        As cited in EPA, AP-42, 1976.

   24.  Lunche, E. G. et al.  Distribution Survey of Products
        Emitting Organic Vapors in Los Angeles County. Chem. Eng.
        Progr. 53. August 1957.  As cited in EPA, AP-42,  1976.

   25.  Communication on emissions from paint and varnish operations
        with G. Sallee.  Midwest Research Institute.  December 17,
        1969.  As cited in EPA, AP-42, 1976.

   26.  Communication with Roger Higgins,  Benjamin Moore Paint
        Company.  June 25, 1968.  As cited in EPA,  AP-42, 1976.

   27.  Shreve, R. N.  Chemical Process Industries, 3rd Ed. New
        York, McGraw Hill Book Co., 1967.   p. 454-455.

28-31.  Reference 3.

   32.  Reference 23.

   33.  Private Communication with Interchemical Corporation, Ink
        Division.  Cincinnati, Ohio.  November 10,  1969.   As
        cited in EPA, AP-42, 1976.
                                  332
-------
4.9       Surface Coating

          According to the American Society for Testing and
Materials, a surface coating is "a liquid, liquifiable, or
mastic composition which is converted to a solid protective,
decorative, or adherent film after application as a thin lay-
er,"  The various types of surface coatings include paints,
varnishes, lacquers, stains, shellacs, polymer films, waxes,
and oils.  These coatings are applie-d to metal, paper, fabric,
wood, glass, stone, concrete, plastic, and other types of
surfaces.  The actual processes by which a surface coating is
applied may vary considerably from one industry to the next....
The application of coatings to-metal, paper, fabric, and
wood surfaces and the applications of "adhesives are described
in the following paragraphs.

          Metal -Coati-ng -      ••   "       ••-•••.-.

          There are several industries involved in metal coat-
ing operations.  The major industrial,.sources of organic
emissions in metal coating are auto and  light truck coating,  can
coating, coil coating, large appliance- coating, metal  furniture
coating, -and magnet wire coating.  Other metal coating operations
which also contribute significant quantities of organic emissions
include  small appliance finishing, fabricated metal products  fin-
ishing,  and industrial, farm, and commercial machinery finishing.

          In auto and light truck coating  the body  is  initially
treated  in a phosphate wash cycle to  improve paint  adhesion and
corrosion resistance.1'2  The first coat,  a primer, is applied by
dip and/or spray methods and then the unit is baked.   The  topcoat
is then"  applied in one to three steps, usually with a  bake  step
after each.  Assembly is completed in the  trim shop.   If the
                               333
-------
coating is damaged during the trim step, repainting is done in
a repair spray booth.

          Two types of coatings are commonly used:  enamels and
lacquers.   Enamels are coatings thinned with solvents; enamels
form a coating by polymerization.  Lacquers are resin-pigment
combinations dissolved in solvents that form a coat by evapora-
tion of the solvent and deposition of the resin and pigment.3
Primers are usually enamels and top coats may be either enamels
or lacquers.

          Cans are manufactured in one of two ways depending on
whether the can is two-piece or three-piece.  A two-piece can is
wall-ironed (extruded) from a shallow cup of aluminum or steel.
The exterior body of the can is sometimes reverse-roll coated,
usually with a white base coat.  After baking, a rotary printer
roll coats any design or lettering on the can.  This can be fol-
lowed by a direct roll coat of protective varnish before the fin-
al baking.  In addition the can is spray-coated with a lacquer
on the interior and baked.

          In the manufacture of three-piece cans, large metal
sheets are initially roll coated with an interior lining.  This
is sometimes followed by roll coating an exterior base coat or
size coat before baking.  After the exterior base coat, an ink
design and over-varnish may be applied and baked.  The sheets
are then split into can body size blanks, formed into a cyclinder,
and welded, cemented or soldered.  The interior and exterior of
the seam are usually sprayed with an air-dry lacquer to protect
the exposed metal.  Can ends are stamped from coated sheets of
metal in a reciprocating press.  The perimeter is coated with a
synthetic rubber compound that functions as a gasket when the
end is assembled on the can."
                             334
-------
          Coil coating involves the coating of any flat metal
sheet or strip that comes in rolls or coils.  Prime coats can
be applied on one or both sides usually by reverse or direct
roll coating.  Electrodeposition is also used for applying a
prime coat on aluminum coils or a single coat on steel coils.
After baking, the second coat or topcoat is applied by reverse
or direct roll coating.  The topcoat is baked on and the metal
is ready for any printing or embossing before being shaped into
a finished product.  If an adhesive is applied, it is activated
in the oven and then vinyl, fabric, metal, or other materials
can be laminated onto the metal coil.5

          In Large appliance coating.,,, prime coats are applied to
interior parts by flow or dip, coating techniques and often to
exterior parts by flow or .spray coating techniques.  After baking,
interior parts are ready for assembly and exterior parts receive
a topcoat by automatic electrostatic spraying.  Exterior parts
for some appliances, such as refrigerators and freezers, are top-
coated directly with no prime coat.  Manual air spraying is used
for touchup and shading.  After final baking., the parts are ..-
assembled.

          Metal' furniture parts may be coated while they are un-
assembled, partially assembled, or completely assembled.  A prime
coat may be applied but is usually not necessary.  The prime coat
is usually baked before a top coat is applied.  Prime and top
coats are applied by spraying, dipping, or  flowcoating.  Spray-
ing methods.are preferred when frequent color changes are neces-
sary.  The coated furniture is usually baked in an oven, but may
be air dried.6

          Magnet wire  coating is  the  application of insulation
varnish or enamel onto an electrical wire.  The wire  is unwound
                              335
-------
from a spool, passed through a bath of coating, and then drawn
through an orifice or die.  Excess coating is scraped off,
leaving a layer of uniform, predetermined thickness.  During
baking, the solvent is driven off and the coating is cured.

          Paper, Film, and Foil Coating

          Paper, film, and foil are coated for a variety of
decorative and functional purposes.  Waterborne, organic
solvent-borne, or solventless extrusion type materials are
used.  A typical coating line consists of an unwind roll, a
coating applicator, an oven, various tension and chill rolls,
and a  rewind roll.  Coatings may be applied to paper by several
different devices such as knives, reverse rollers, or rotogravure
rolls.  After coating, the paper is sent.to an oven or dryer
which  may contain two to five temperature curing zones.7

          Fabric Coating

          Fabric coating involves the coating of a textile sub-
strate with a knife or reverse roll coater.  Fabric coating im-
parts  properties that are not initially present, such as strength,
stability, water or acid repellancy, and appearance.8  Substrates
can be either natural or man-made.  Coatings may be either aqueous
or organic borne and  include latexes, acrylics, polyvinyl chloride,
polyurethanes, and natural and synthetic rubbers.

          A typical fabric coating line consists of four opera-
tions :  milling, mixing, coating application,  and drying and
curing.  Milling and  mixing are  coating preparation steps and
vary with pigments, curing agents, fillers, and solvents.  The
fabric coating is normally applied by a knife  or reverse roll
coater, although rotogravure printing has recently been widely
                              336
-------
used in vinyl coating of fabrics.  After coating, oven curing
is used to increase the rate of solvent evaporation.  For
some coatings, oven curing produces chemical changes within the
coating solids to give desired properties to the product.9

          Application of Adhesive s_

          Adhesives are used for joining surfaces in assembly
and construction of a large variety of products such as pressure
sensitive tapes and labels, rubber products, and auto assembly.
Adhesives may be water-borne,, organic solvent-borne, hot melt .or
high solids.  Virtually all of the organic solvent used for the..
application.-o-f -adhesives. is emitted to the atmosphere when the
'adKe's-ive- dries...        ,-.•---

          Coating of Flat Wood Products

          Flat wood products such as plywood, particle board,
hardboard, cedar siding, and softwood molding are often coated
with a variety of fillers, -sealers, or topcoats.  Application
is usually by direct or'reverse roll doating.  Wood-grain patterns
can also be printed.  Following the application, the coating is
dried in an infrared or steam-heated "oven.

          Wood Furniture Coating

          Although the procedure  for wood  furniture  coating may
vary from one company to the next,  the process  typically  con-,
sis'ts. ,of several coating applications.   Various  liquid mixtures
are used to bleach, stain,  fill,  color,  wash, highlight,  or  seal
the wood .s.urface.  Application  is most commonly  done by  dip  or
spray methods.  Drying can  be open  air or  oven  bake  at  tempera-
tures not exceeding 60°C  (140°F).1 Q  Standing between  coatings
is optional.' Almost all furniture  manufacturing operations

                               337
-------
employ conveyors to transport articles from the woodworking de-
partment through finishing for storage or shipping.11  Finish
coatings are usually of very low solids content with attendant
high emissions of volatile organics.

4.9.1     Emission Characteristics

          According to one source, the total volatile organic
emissions for industrial surface coating operations  are 1.36
Tg/year  (1.5 x 106 tons/year).12  Quantities and sources of or-
ganic emissions from the industrial surface coating  operations
described in Section 4.9 are given in Table-4.9-1.

          The quantity of emissions from each  operation depends
on several factors such as type of material to be coated,
coating  thickness, desired finish, coating process,  percent
overspray, and paint formulation (% water and  70 solvent).
Materials on which coatings are to be applied  can be as smooth
as glass or as irregular as concrete.  A lustrous finish may
be required for visual appearance or a weather resistant finish
may be required for endurance.

          Coating processes vary significantly within the  sur-
face coating industry.  For example, the auto  industry may use
either a dip or spray method of coating while  paper  and fabric
coating  rely almost exclusively on application by knife or
reverse  roll method.  In most  coating operations, 10 to 90 Der-
cent of  the solvent is evaporated at the application and/or
during subsequent air drying.  The remaining 10 to 90 percent  is
evaporated in the oven.  Table 4.9-2 provides  a general range  of
emissions resulting from typical surface coating operations.

          Spray coating produces high emission rates, and  spray
booths are usually open on one side.  The amount of  sprayed
material that misses the surface to be coated  (overspray)  is a
                               338
-------
TABLE 4.9-1.
SOURCES  AND ESTIMATED QUANTITIES OF ORGANIC
EMISSIONS  FROM  INDUSTRIAL  SURFACE  COATING
OPERATIONSl 3
                                                Bf
                                                               Muuatl
             Indu«try Proc«»»
                                                                          (10*
    WXU.
     Autojpfatl* «tB| Light Truck
       X) Sprij booth rat {lath-off MM
       2) OMB
     Gag Coating
     jjitrt
                         55-90
      1) Spray
         «) STT«T booth md
         b) 0«n
      2) Dip or fltwenmr »ppllc««lo&«
         b)
     tell ..Partial" '
      1) Co«t«r »r««
      2) OVMI
      3) Upmb mm.
          Wirt
   PAPER CDATIHC
     1} Co«tlng line
     2) Oth«r •ouros
   I one COATIBC
     1) CoKlag Lla«
   FLATWtXID PRODUCTS
   HOOD nrmxuiE COATISC,
     1) Spr*y booth
     2)
                         ss-ao
                         20-35
                         40-50

                          8
                         90
                          2
                         TO
                         30

                         40-70
                         30-40
138

128
 92
 304

 282
 202
               .64
                                                              42
                                                               a
 96


212
 s*
232 -
 18

 862



 211


 466

 185

(510)
                         ss
                         15
   *Tlture» ui for * typic*! c»n coating line
                                     339
-------
major factor in solvent emissions.  Table 4.9-3 describes the
percentage of overspray as a function of spraying method and
sprayed surface.  Solvent emissions from spray booth stacks can
vary from less than 0.45 kg/day (1.0 Ib/day) to more than 1,360
kg/day (3,000 Ib/day),  depending on the extent of the operation.16
If a water curtain is used for the control of particulate emis-
sions ,  a 1070 reduction in the organic vapors discharged can be
anticipated.17  Solvent is recovered from contaminated water by
a suitable separation technique.
     TABLE 4.9-2.
    PERCENT OF TOTAL EMISSIONS FROM VARIOUS
    COATING PROCESSES1"

Coating Method
Spray Coat
Flow Coat
Dip Coat
Roller Coat
Coating
Application
30-60
30-50
5-10
0-10
Process
Pre/Air Dry
10-40
20-40
10-30
" 10-20

Bake
10-40
10-30
50-70
60-90
 TABLE 4.9-3.
PERCENTAGE OF OVERSPRAY AS A FUNCTION OF SPRAY-
ING METHOD AND SPRAYED SURFACE15
Method of Spraying
Air atomization
Airless
Electrostatic
Disc
Airless
Air atomized
Flat
Surfaces
50
20 to 25

5
20
25
Table Leg
Surface
84
90

5 to 10
30
35
Bird Cage
Surface
90
90

5 to
30
35



10


                              340
-------
          The quantity of solvent emissions is highly dependent
on the paint formulation.  For example, emissions from applica-
tion of a high solids coating (80% solids) are less than 0.24 kg
of organic solvent per liter of solids applied (2.0 Ib/gal).
Application of lacquer produces more than 5.4 kg of organic sol-
vent per liter of solids applied (45 Ib/gal).   This definite
difference in emission rates due to paint formulation is well
illustrated in Figure 4.9-1.

          All of the previously discussed factors contribute
significantly to the emission characteristics of a particular
surface coating operation, but there are additional points to
be considered.  For instance, the extent of air drying which
occurs"prior to baking may mean.that the solvent mixture re-
maining in the coating at the beginning of the baking operation
is much richer in the high boiling solvents.  This may result
in chemical changes upon high temperature baking.

          A suggested equation for estimating the potential
solvent vapor emissions from surface coating operations is
given below:

          u - 1000 A n  (1 - 0.01 P)
          w -         p«j.p

          W = weight of  solvent vapors in kg
          A = area coated (sq. m.)
          n = thickness of dry coating (cm)
          P = percent solids by volume
          f = efficiency factor (dimensionless) empirically
              determined (f <_ 1)
          p = solvent density (kg/liter)
                               341
-------
             100
                                            4.8
                                           (40)
                                    6.0    7.2
                                   (50)   (60)
          KILOGRAMS (POUNDS) OF ORGANIC SOLVENT EMITTED PER LITER (GALLON)
                             OF SOLIDS APPLIED
Figure 4.9-1.
Percent of  Solids Versus Kilograms  (pounds)  of
Organic Solvent  Emitted Per Liter  (gallon)  of
Solids Applied.   (Assumption:  Solvent  Density
0.79 kg/l - 6.6  lb/gal).i«
                                 342
-------
 or
          w   0.0623 An(l-  0.01  P)
             «           -          —   p
          W *  weight  of solvent  vapors  in Ib.
          A =  area coated (sq. ft,)
          n =  thickness of dry coating  (mils)
          P »  percent solids  by  volume
          f -  efficiency factor  (dimensionless)
               empirically determined (f < 1)
  ".""      p =.  solvent density (Ib/gal)

 This  equation  incorporates parameters for" area to b.e
 thickness of the  coat,  percent of solvent in the coating,  -and
 efficiency  of  coating application,19      -                   •   •'  ••••

 4.9.2    Control Technologr

          Valatile organic emissions from surface coating opera-
 tions can be reduced  by add-on control  devices and by process
 and material changes.  Add-on devices include .carbon adsorption
 units,  incinerators,  condensers, and scrubbers.   Process and ma-
 terial  chang.es include electrostatic spray' coating, electr»d.epo-si-
_tion,  electron beam curing, ultraviolet curing,  and coating nodi-
 fication (waterborne  coatings, high solids coating, powder coat-
 ings.,  and hot  melt formulations) .  Since the surface coating
 industries  vary in raw materials handled and products manufactured,
 each  industry  is  faced with unique emission problems and alternate
 solutions.   Tables 4.9-4 and 4.9-5 summarize the utility and effi-
 ciency  of the  many emission control schemes available to the ma-
 jor surface coating industries.   The control efficiency is stated
 in terms of the percent reduction in organic emissions from appli-
 cation.  of the  control method. Applicable control techniques are
 described for  each industry in the following paragraphs,

                               343
-------
          TABLE  4.9-4.
TYPICAL EFFICIENCIES  FOR ADD-ON
CONTROL EQUIPMENT20"26
                                     Control Efficiency (Percent)
                                                      Incineration
Industry
Metal Coating
Auto & Light Truck Assembly
Can Coating
Coil Coating
Large Appliance Coating
Metal Furniture Coating
Magnet Wire Coating
Fabric Coating
Paper, Film, and Foil Coating
Adhesives Coating
Flat Wood Products Coating
Wood Furniture Coating
Carbon Adsorption

85+b
85-90b
b
b
90
b
90-95
90+
b
b
b
Thermal/Catalytic'

95/95
90-98/90
90-98/90
90-95
90
90-95/90-95
9.0-95/90-95
95/95b
b
90
b
 Numbers represent percent reduction across the control device and do not
, include the capture efficiency into control device.
 Not widely used in this industry.
4.9.2.1   Metal  Coating
          Automobile and Light Truck Assembly
           Emissions from automobile  and light truck assembly are
produced during priming and topcoating operations.  While several
control  methods are applicable,  the  most effective way to minimize
organic  emissions from prime coating operations is electrophoretic
priming  with waterborne surfacer.  For the prime coat, the use  of
waterborne spray coatings also merits consideration, although the
reduction in emissions is somewhat less than for electrodeposition
Incineration of oven exhaust can be  efficiently accomplished, but

                               344
-------
             TABLE 4.9-5.   TYPICAL EFFICIENCIES FOR PROCESS AND MATERIAL  CHANGES
27-90
US
•f^
m

Metal Coating
Auto i. Light Truck
Aaaenbly
Can Coating
Metal Furniture Coating
Call Coating
targe Appliance
Coating
ftignet Wire Coating
fib tic Coating
PJII.I, fllat, and roll
Coating
/UIt*»lve> Coating
fiat Hood FruJ.icts
Casting
lji»oj Furniture Coating

Waccrbornt
Coating*

80-9}?
40-92*
*0-90
90-95
60-90
80
90*
—
80-100
80-99

80-99
80

c

High-Sol Ida
Coating*

0-86

40-90
50-80
60-90
60-30

—
80-100
—

—
— .

c
Central EfJicitocj (Percent)
Powder . Hot Mali Oltra»iol«t Ixtraviaa
Coitlngi ' fonAdatioM Curing flutlcola Coating*

— . ,' ~ — ' — —

9 V W ' " — 100 — —
M-9J — _ _ _-
— _ _ —
55-9» :,_ .. _ — .
* ' '
— . _ — _
' — 99* _ —
— 99* . ~ 95-99 99*

— 80-99 80-99 — —
_ _ • ._ 9j+ —


        Ejectro^epasH ton of pri


        Topcoat


        £St*eiatlc« unavailable.
-------
the reduction in emissions is minimal since less than 15% of the
solvent evaporates there.  The use of add-on equipment for prime
spray booths is technologically feasible but will probably not
occur due to the advantages of a transition to an electrophoretic
coating.

          The best means of controlling emissions from topcoat-
ing lines is by increasing the solids content in coating formula-
tions or by using waterborne coatings.   The reduction in solvent
emissions is particularly significant for those plants using
lacquers.  Add-on devices for spray booths are technically feasi-
ble, but difficulties have been encountered in application.  For
example, excessive partlculate matter can reduce carbon life in
an adsorption system.  There are also substantial energy require-
ments associated with the incineration of spray booth exhaust.  As
before, incineration of oven exhaust is effective but has little
impact on the overall reduction of emissions.

          Can Coating

          In oven dried spray operations, about 50-75% of vola-
tile organic emissions are fugitive.  In air dried spray and
end sealing operations of the can coating industry, about 100
percent of the organic solvent vapors emitted are fugitive emis-
sions within the plant.31  For this reason conversion to water-
borne or high solids coatings is the best control option, as well
as one of the most economical.  In roll coating operations, con-
version to water-borne, high solids, or ultraviolet curable coat-
ings is the best option.  The major problem with such solvent re-
formulation is that many coatings are still in the developmental
stages or are undergoing tests by both the Food and Drug Adminis-
tration and the packing customer.  Incineration is a proven retro-
fit control system which can be economically designed to eliminate
any incremental energy requirements through the use of primary
and secondary heat recovery systems.  Carbon adsorption can also

                               346
-------
be  considered an economic alternative if recovered solvent mix-
tures  are used as fuel  to generate steam for carbon regeneration.
The use  of an incineration or carbon adsorption system will re-
quire  that the coater either be covered with a hood which ducted
to  the oven exhaust  stream or be enclosed up to the oven entrance
so  that  the coater emissions are drawn directly into the oven.

           Coil Coating

           In the coil coating industry as in other industries,
no  single best.control  system is apparent.32  Due to the typi-
cally  high curing temperatures and the various mixtures-"O.f /or--"  •'•'
-g-anic  solvents found in the coatings, incineration is th"e"'bes*t
..add-on control technique,  Conversion to waterborne or "zaedluni-
to  high-solids" coatings has been successfully applied, within
limits,  to several existing coil coating lines with favorable-"  .
.results.  If incineration is chosen and no heat recovery tech-
niques are incorporated, fuel requirements can be substantial.
For coil coaters, significant advances have been made in the use
of  incinerators with heat recovery.  In catalytic incineration
care must be taken that solvents do not poison the catalyst or
cause  temperature limits to be exceeded.

.-•"•••     " Large" Appliance •Coating

           Like many  other surface coating industries, there are
several  emission control routes available for large appliance
co-ating.  Although the  use of powder coatings and electrodeposi-
tion provide the greatest emission reduction, they usually re-
quire.-the most extensive equipment changes.  On the other hand,
waterborne and high-solids coatings can be applied with existing
equipment but do not achieve the same degree of emissions reduc-
 tion.   The utility of retrofit devices such as adsorbers and  in-
 cinerators may be limited by the cost, fuel requirement, and
 available space.
                                347
-------
          Metal Furniture Coating
                                 3 3
          Emissions from metal furniture coating may be reduced
by substitution of low solvent coatings or by add-on equipment.
Powder coating and electrodeposition of a water-borne coating
provide the greatest emissions reduction.  The use of water-
borne coatings requires no major equipment alterations and makes
color changes a simple matter.  The use of high solids coating
is usually less efficient than the other methods.   Carbon ad-
sorption for application and flashoff areas is considered tech-
nically feasible but has not yet been applied.  It would re-
quire a significant additional floorspace.  Incineration has
been successfully used for ovens.

          Magnet Wire Coating

          The most common emission control technique used in
magnet wire coating is incineration (catalytic and thermal).
Modern wire coating ovens are equipped with an internal cataly-
'»
tic incinerator which recovers -heat by burning solvents inside
the oven and eliminates malodors and the buildup of flammable
resins in the stack.  Only limited success has been achieved in
developing powder coatings and waterborne coatings.

4.9.2.2   Paper, Film, and Foil Coatings

          Both incinerators and carbon absorbers have been  suc-
cessfully retrofitted onto a number of paper coating lines. Sev-
eral low solvent paper coatings  (waterborne, plastisols, organi-
sols, and hot melts) have recently been developed and show  promise
for the future.  At present several technical problems still
need to be solved.  For instance, waterborne coatings are not  as
effective as organic solvent  coatings in providing weather, scuff,
                              348
-------
and chemical resistance for some uses.  In addition the use of
waterborne coatings has resulted in wrinkling of the paper and
other application problems.  Hot melt application cannot be used
for coating materials that char or burn.

4.9.2.3   Fabric Coating

          As with other surface coating industries, the primary
control systems for fabric coating are incineration and carbon
adsorption.  For an operation which uses a single solvent or
solvent mixture, adsorption is the most economical option.
Some companies have implemented this method and found it to be
very efficient.3''  If, on the other hand, several solvents or
solvent mixtures are required, then incineration (thermal or  •
catalytic) with primary and secondary heat recovery is most ap-
plicable.  The use of low solvent coatings has been encouraging
but limited.  Both high-solids and waterborne coatings have been
used and often the coating equipment and procedures need not be
changed to accomplish conversion.  The major disadvantage is that
every coating line is somewhat unique and many coated fabrics
have different applications.  This often means high research and
development costs.

4.9.2.4   Adhesives Coating

           Replacement  of  organic solvent-borne  adhesives with
waterborne, hot melt,  solventless  two component, or radiation
cured  adhesives is the best method for reducing  emissions  from
adhesives  coating operations  where it is  applicable.   More  than
half of  the total adhesives applications  employ  waterborne  natural
adhesives  such  as animal  glue,  starches,  dextrin,  and  proteins.
Water-borne synthetic  adhesives  have  been developed recently
which  are.comparable  to waterborne natural  adhesives.   However,
                              349
-------
water-borne adhesives are not compatible with plastic substrates.
In addition, the cost of retrofitting existing equipment to use
hot melts or high-solid materials can be prohibitive.

4.9.2.5   Flat Wood Products Coating

          Basically three emission control techniques are used
in flat wood products coating:  low-solvent ultraviolet (UV)
curable coatings, waterborne coatings, and incineration.  UV
curable coatings rapidly polymerize to form a film when exposed
to UV radiation.  UV filters are frequently employed and occa-
sionally UV curable topcoats are used.  Opaque .base coats are
not yet available in a UV curable formula.  It has been suggested
that UV curable inks from the paper coating industry could be
used for grain printing as well.  A major problem with UV curable
coatings in general is the difficulty in curing irregular shapes,
although this is not a problem with flat wood products.

          Waterborne coatings are available for filling and base
coating but waterborne topcoats or graining inks are essentially
unavailable.  Some problems have been encountered with poor ad-
hesion or staining and "blocking" (the sticking of the paper
sheets used to separate the boards).

          The use of afterburners on baking ovens has been  suc-
cessfully applied.  There are no reports of the use of carbon
adsorption units, although the application is technically feasible.

4.9.2.6   Wood Furniture Coating

          In general, Significant reductions in the organic sol-
vent emissions from wood furniture coating can be realized by
switching to waterborne coatings.35'36  Small reductions can be
                              350
-------
 realized  by  practicing  proper  spraying  techniques  or using elec-
 trostatic spraying,

           Coating reformulation is  currently one of the most
 promising means  of reducing organic solvent vapor emissions in
 wood furniture  coatings.   Of particular interest is the advent
 of waterborne coatings,  some of which contain 5 to 15 percent or-
 ganic solvent by volume.37  The composition of a typical nitro-
 cellulose solvent-borne furniture coating is 12% solids and 88%
 organic solvent  by volume,  A  typical waterborne furniture coat-
 ing  is 407. solids, 48%  water,  and 12% organic solvent by volume.38

           Unfortunately, s.otae problems have been encountered with
 tte*-experimental use of waterborne  coating.  Longer drying times
 £o:r''wa-terbo;m-e. coatings result in slower furniture production rates,
 Additional p-roblems include-.appearance, repairabillty, - compati-
 bility between  various  coating layers,  mar resistance,  and re-
 sistance  to water and alcohol  stains,

 4.9.3    . Cost,_ Energy,  -and Environmental,._Impa_ct of Controls

           This  section  includes cost data, energy requirements,
 and  environmental impact developed specifically for control meth-
 ods  .for most surface coating operations discussed in the previous
 section.   Specific data is unavailable in the consulted litera-
 • tore-for  large  appliance coating, magnet wire coating,  adhesives
 coating,  and flat wood  products coating.  Section 3 of this docu-
•.ment includes in-depth  treatments of the major methods  used for
 controlling  volatile organic emissions  in industry.  The data
 givtrr-ih  this section are not  as fully developed as those in-
 cluded in Section 3.  For specific  details, assumptions, and
 bases the reader is referred to the original source.
                              . 351
-------
4.9.3.1   Metal Coating

          Automobile and Light Truck Assembly

          Substitution of electrophoretic dip priming for more
traditional coating methods involves a high capital cost.  The
total installed capital cost is about $8 million for a typical
plant.  Increased operating costs are estimated to range from
$108,000 to $948,000/yr.  Electrical requirements are increased
by about 1400 kW (4.8 x 106 Btu/hr) by switching to electropho-
retic coating representing a 12 percent increase.  The coatings
contain amines which are driven off during the drying step, thus
generating a secondary pollutant.  Incineration has been used as
a control method for this problem.89   Capital costs for converting
from lacquer to enamel are estimated by EPA to be about $1 million
for a typical automobile and light truck assembly plant.  A very
rough estimate of annualized operating expenses is $120,000.
The actual costs are difficult to assess, however, as they are
very site-dependent.  The overall energy requirements should be
lower, but specific estimates were unavailable in the sources
consulted. ** °

          Capital costs for carbon adsorption control devices for
spray booths are largely dependent on flow rate.  Estimated costs
for a 1300  m3/min  (50,000 ft3/min) unit are $3-20 million capital
costs and $1-7 million annualized costs.  (The lower numbers repre-
sent the case for 50 percent solids, the higher ones represent the
case for 12 percent solids.)  Electrical and steam requirements are
large:  steam requirements are 3.42 Mg/hr (7.55 x 103 Ib/hr).
A potential water pollution problem exists because of steam re-
generation in which organic substances are contacted directly
with steam.  The organic compounds would have to be separated
                               352
-------
from the condensed  steam before  disposal,1*1  An  alternate  approach
is incineration  for the steam  and  solvent  or hot air  and solvent
stream."2-"5

           Cost and  energy  data for incineration  of top coat spray
booth exhaust are presented  in Table  4.9-6,  The low  flow  rates
and low organic  vapor  concentrations  require the addition  of larger
amounts of fuel.  Furthermore, the capacity for  use of recovered
heat is limited  to  primary heat  recovery."8  Incineration  has a
..secondary  pollutant potential.   Combustion products,  such  as
NQX, S02 ,  CO, and acids may  all  result,  depending on  the cpmp.osi-
tioiT'of the substance  being  combusted.                     .•-•••••

           Incineration may" also  be used  to control volatile- -of '-••••
gan.ie emissions  from primer  and  topcoat  ovens.   Costs and  energy
requirements  are summarized  in Tables 4.9-7 and  4.9-8 for  in-
cinerators operating at  10 .and 15  percent  of  the lower explosive
limit.  Three cases are  shown:  no heat  recovery, primary  heat
recovery only, and  primary and secondary heat  recovery, A com-
parison of the two  tables  illustrates the  beneficial  economics
of minimizing dilution. "Combustion devices have the  potential for
causing NOX and  CO  emissions.  If  sulphur  compounds are present,
''S0'2 emissions will  also  result,  and combustion of halogenated
compounds  results-in acid  formation.

           Converting a fairly new  auto and light truck assembly
facility  for use of water-borne  topcoats is  estimated to cost
about  $20  million.51  If the entire coating line must be replaced,
the costs  will be about  twice that.52  Increased operating costs
are about  $5 million per year for  a typical plant.  Electrical
requirements are increased by 5000 kW (17.2 x 10€ Btu/hr); this
                                353
-------
            TABLE 4.9-6.   COSTS  AND ENERGY  REQUIREMENTS FOR  INCINERATING  EXHAUST GASES FROM
                            AUTO AND LIGHT TRUCK ASSEMBLY TOPCOAT SPRAY BOOTHSa," 6 , " 7
to
Ln
No Heat Recovery

CapUial Cost
Operating Cost
Fuel
Requirements
Electrical
Requirements

Catalytic
$1.6-12 million
$2.1-15 million
53-390W
(182-1330Btu/hr)
447-3260kw
(1500-11000
MBtu/hr)
Noncatalytic
$1.3-9.4 million
$4.1-30 million
143-1050W
(494-3610Btu/hr)
349-2550kW
(1200-8800
MBtu/hr)
Primary Heat Recovery Primary Heat Recovery
(38 percent efficient) (85 percent efficient)
Catalytic
$2.0-14 million
$1.8-13 million
34-250Wb
(118-862Btu/hr)
723-5280kW
(2500-18000
MBtu/hr)
Noncatalytic
$1.5-11 million
$2.9-21 million
91-670Wb
(314-2300Btu/hr)
719-5250kW
(2500-18000
MBtu/hr)
Noncatalytic
$2.1-16 million
$0.4-2.6 million
15.4-110W
(53-384Btu/hr)
645-4720RW
(2200-16000
MBtu/hr)
       'The smaller numbers are for the 50 percent solids  case, 7000 NmVmin (248,000 scfm) .

       lThe larger numbers are for the 12 percent solids case, 48,000 NmVmin (1,815,000 scfm).

        Includes credit for recovered energy.
-------
           TABLE  4.9-7.   ESTIMATES  OF  COSTS AND ENERGY REQUIREMENTS  FOR  INCINERATION  OF
                               EXHAUST  FROM  PRIMER  AND  TOPCOAT OVENS  IN  AN AUTO AND LIGHT TRUCK
                               ASSEMBLY PLANT1*8    (1Q7. Lower  Explosive  Liiait)


                         	Ho Beat Kgcnvery  '	    '	Prlaary Heat iacovary	       Frlaary and Secondary Heat >ecovery
                             Catalytic          Noncatalytlc        '  Catalytic          Noncatalytic         Catalytic           Moncatalytic
      Capital Cost
      For both o.ens      $136,000   $296,000   $132,000   $238.000  $204.000   $396,000   $157,OOO  $298.000   $182,000   $422,000   «S5.9OO   $349,000


      Total annual
      Operating Cost      $ 60,700   $237,000   $  99,200   $424,000  $ 73,000   $212,000   $ 83,700  $311,000   $ 61,000   $182,000   $ 71,000   $209,000


      Net Energy                          '                                                 '•    ,
      Requirement           430       2)00       1900      1100       230       1300      1100 .''   •6800   negligible  negligible negligible   3000
      kW (106Btu/ht)       (1.5)      (8.8)     (6,6)     (39.0)      (0.8)     (4.6)     (3.9)     (23.))   negligible  negligible negligible  (10.8)


<-°    Electrical
~?    Requirenent            13        110        12        83        21        14        18       127       24       166        24       166
      kW (MBtu/hr)          (4})       (380)      (41)      (290)       (72)      (48)      (62)      (440)       (83)     (570)       (81)      (570)


      "umer (lot rate (SOX aotlds enual) 43 Hm'tmla (1600  acfai)  foi" prtscr oven and 91 Ita'/Bln (3400 acfn) for topcoat oven.
      bl!fglier flow rate (32Z aol Ida priaer and 12X  lacquer topcoat)  120  Nai'/aiin (4SOO aefn)  for prlawr oven and 670 Ma'/«lo (25,000 scf«) for topcoat oven.
-------
     TABLE  4.9-8.   ESTIMATES  OF  COSTS  AND ENERGY  REQUIREMENTS FOR  INCINERATION OF
                        EXHAUST FROM  PRIMER AND  TOPCOAT OVENS  IN AN AUTO AND  LIGHT  TRUCK
                        ASSEMBLY PLANT*•   (157. Lower Explosive  Limit)
No Heat Recovery
Catalytic Noncatalytlc
a b a b
Primary Heat Recovery
Catalytic Noncatalytlc
a b a b
Primary and Secondary Neat Recovery
Catalytic Noncatalytlc
a b a b
Capital Coat
Both Ovens          $106,000   $281,000   $107,000  $239,000  $123,500  $340,000   $123,000   $281,000   $143,000   $400,000   $144,000   $341,000


Total Annual
Operating Coat      $ 48,600   $197,000   $ 58,800  $254,000  $ 42,500  $147,000   $ 48,500   $163,000   $ 42,500   $105,000   $ 44,000   $102.000




to
Ui



Net Energy
Requirement
kU (i 10*
Btu/hr)

Electrical
Requirement
kU (x 10*
Btu/hr)


3S
(1.2)



10.6
(.37)


260
(9)



80
(2.7>


81
(2.8)



8.2
(.28)


620
(21.5)



62
(2.1)


S.8
(0.2)



13.3
(.46)


260
(9.0)



100
(3.4)


33
(1.3)



12.2
(.42)


620
(21.5)



92
(3.2)


-19°
(-.67)



16.0
(.55)


-150C -3.8C
(05.0) (-.13)



120 16.2
(4.2) (.55)


-29
(-1.0)



122
(4.2)
aLower flow rate:  (50X solIda enamel)  30Nm'/mln (1,100 acfm)  for primer oven and 59Ma'/mln (2,200 acfm) for topcoat oven.
blllgher flew rate:  (32X aollda primer  and 12X aollda topcoat) 223Nm'/mln (8,333 acfm) for primer, oven and 445Nm9/mln (16,666 scfm)  for topcoat oven.
 Negative sign  Indicates energy recovery exceeding energy Input.
-------
represents a 42 percent increase.53  'An assessment of the envir-
onmental impact of changing to water-borne pigments must include
consideration of the fact that the liquid effluent from water-
borne pigment systems will require treatment prior to disposal.
In addition, a solid waste problem is created because water-
borne coatings do not dewater well in the overspray collection
water.!"

          Can Coating

          Conversion to high-solids, water-borne pigments,., or__•
powder coatings in can coating plants may require some expensive
equipment changes, depending on the existing equipment.  The
costs are largely undefined at this time.  The coatings'themselves
are often more expensive, as well.  To be added to the total ex-
pense are research and development costs for testing of the pro-
duct.55  Some cost data developed for using carbon adsorption  in
the can coating industry are presented in Table 4.9-9 for an
"ideal" facility.  An environmental effect may be caused by the
requirement • for a filter"'before the'-carbon beds.  The particulate
matter coll'e'e'ted in tHe filter forms—a solid waste stream which
must be disposed of.  Waste water effluents must be considered
if steam is used for regeneration  (due to water miscible solvents"
the condensate stream must be treated in a manner which circum-
vents a water pollution problem.57

          .Ultraviolet curable coatings are about twice as  expen-
sive  as conventional coatings.  Energy requirements are reduced
by about 60 percent, however.58  Some cost data for an "ideal"
can coating plant using  incineration as a control method are
presented in Table 4.9-10.
                               357
-------
CO
l_n

CO
                TABLE 4.9-9.    COSTS  OF CARBON ADSORPTION IN THE CAN  COATING INDUSTRY56


                                          (157. Lower Explosive Limit)
Costs
Installed
Capital Cost
Annual Ited
Operating
Costs
No Solvent Recovery
130Nm'/mln 400Nm3/nln
(5000 scfm) (15000 scfm)

$162,000 $302. OOU

$60,000 $142.000

Solvent Recovery
Value
ISONm'/min
(5000 scfm)

$152,000

$42,000

Cited at Fuel
400Nm'/Mlii
(15000 scfm)

$302,000

$90,000

Solvent Recovery Credit at Chemical
Market Value
nONraVmln
(5000 scfm)

$162,000
"
$15,000

400Nm'/
-------
          Metal Furniture Coating
                                  5 9
          Water-borne and high solids  coatings  are  generally more
cost effective  than are incineration and  carbon adsorption  for
controlling  the emissions from metal furniture  coating.   Powder
coating  is not  as  cost effective  as are water-borne and  high
solids coatings because of high material  costs.

          Energy  consumption may  be reduced by  the  use of high
solids coatings and as much as 70% by.the use of powder  coatings.60
Energy consumption increases with the  use of other  control  methods.
There are liquid  and  solid, waste  disposal problems  with  water-
borne coatings  and carbon adsorption.  A  potential  health';ha2ard
, is  associated-with the use of-*isocyanates in some high solids
"coatings.   Powder coatings ar-e also  subject to  explosions.6   SOX
and NOX  emissions may result,-from incineration.

          Coil  Coating

          Some  costs  and  energy  requirements developed specifi-
 cally for use of  incineration in-coil  coating facilities are
presented  in Table 4.9-11.   Secondary  pollutants (CO, NOX,  SQz,
 acids) may  be emitted by  combustion devices depending on the
 composition .of  the combustion mixture.

           The costs  involved in converting to water-borne.and*
 high-solids•coatings  are  largely undefined.  It has been estimated,
 however, that energy consumption may be reduced by 50 percent, ° **'

 4.9.3.2    Paper.  Film,  and Foil Coatings

           Some  specific cost data for incineration in a  typical
 paper coating operation are presented in Table 4.9-12.   c-
                                 359
-------
                           TABLE 4.9-10.   ANNUAL OPERATING  COSTS  FOR  CONTROL  OF  VOLATILE  ORGANIC
                                               EMISSIONS IN A CAN  COATING  PLANT  BY INCINERATION  62
                                                (157» Lower  Explosive Limit)
                                     No llcnt  Recovery                Primary Heat  Recovery          Primary and Secondary Heat Recovery
                   Flow Rate     Thermal         Catalytic        Thermal          Catalytic        Thermal         Catalytic


                   130Nm3/mln    $72,800         $55,040          $52,600 -        $45,000 -        $59,900 -       $37,300 -
                   (5000 scfn)    $91,800                         $70,600          $50,000         $57,800         $45,300
                   400Nm'/mln    $169,000 -       $120,000         $100,000 -       $85,400 -        $52,700 -       $55,100 -
                   (15000 Hcfni)   $226,000                        $157,000         $102,000        $110,000        $82,100
                    Costs are based on several assumptions.  See original reference  for basis.               .



o                        TABLE  4.9-11.   COST AND  ENERGY REQUIREMENTS FOR  INCINERATION  IN  COIL
                                               COATING PLANTS  FOR THE  CONTROL  OF VOLATILE ORGANIC
                                               EMISSIONS3,b, c,63
                                    No Heat Recovery               Primary Heat Recovery        Primary and Secondary Heat Recovery
                                 Thermal   :     Catalytic         Thermal        Catalytic          Thermal        Catalytic
                              15ZLEL  25XI.KL   15XLEL  25UEL   15ZLEL   25ZLEL   15UEL  25UEL   15TLEL   25XLEL   15XLEL   25*LEL



                 Net Fuel      340     190     58      0       9!      44        00     -80      -150    -200     -230
                 Requirements
                 KW(106Btu/hr)  (9.95)  (5.59)   (1.69)   (0)     (3.14)   (1.5)    (0)     (0)     (-2.76)   (-5.23)  (-5.9)   (-6.8)


                 Annual        $122,580 $85,540  $78,850 $64,450  $74,100  $61,100  $75,030  N.A.     $34,800   $16,910  $39,690  N.A.
                 Operating
                 Cost
                 aCo-!ts and energy values are hancd on several assumptions.  See original reference for basis.
                  Cost data from  Reference 48.   Energy data from Reference 6.
                 cProcess gas flow rate 400 Nm'/mln (15,000 scfm).
-------
                     TABLE  4.9-12.    COSTS  FOR INCINERATION  IN A TYPICAL  PAPER  COATING
                                         OPERATION3•b•  6S
                                   No Heat Recovery          Primary and Secondary Meat Recovery   Primary and Secondary Heat Recovery
                              Thermal         Catalytic        Thermal          Catalytic       Thermal         Catalytic
                  In.sl.n1 led     $125,000        $155.000        $150,000         $180,000        $183,000        $220,000
                  Cost



                  Anmiallzcd .    $105,000        $100,000        $66,000         $75,000         $26,000         $54,000
                  Cost
                  'Costs .-in* based on several assumptions.  See original reference for bases.

                     NmVmln (15,000 srfm)
i-                    TABLE  A. 9-13.    COSTS  FOR CARBON ADSORPTION SYSTEMS  FOR CONTROLLING
                                          VOLATILE  ORGANIC EMISSIONS  IN  THE PAPER COATING  IN-
                                          DUSTRY3 .b-66    (25% Lower Explosive Limit)
                                              No  KrroviTy Cicillt      Solv*at Credit at       Solvent Credit at
                                                                   Harktc Value          Itarkct Valu*
                              Installed Cost       $32.0,000           $320,000 ,            $320,000




                              Aiinu.-iHzed Cost      $127,000           $f>0,000     ':        -$100,000

                                                                            •  i       ,

                              'Cost pst Im.ites Involve several assumptions.  See original reference for bases.

                              ''2W. I'.owor Hxploslvc l.lmlt; 400 Nm'/mln (15,000 scfm)      •   •'
-------
costs for carbon adsorption control devices used in paper coating
operations are presented in Table 4.9-13.  Unless a solvent mix-
ture can be recovered in a useable form, it is considered more
economical to incinerate and recover heat than to install a car-
bon adsorber.67  Costs of equipment necessary for changing to
low solvent coatings can be very expensive.  Initial development
of the coatings can also be very expensive.68  A cost comparison
of various types of silicone application systems is shown in
Table 4.9-14.

TABLE 4.9-14.  COST COMPARISON OF APPLICATION METHODS FOR SILICONE
               COATINGS69
      Application System                     cost $/lb
                                     Silicone Solids on Paper
Organic Solvent  (with recovery)                8.20
Organic Solvent  (with incinexation)            7.38
Solventless  (heat  set)                         7.11
Organic Solvent  (no recovery)  .                6.69
Water Emulsion System                          5.28
4.9.3.3   Fabric Coating

          There are  some costs developed  specifically  for  incin-
eration and adsorption as  control method  in  fabric  coating plants.
These  data are included in Tables 4.9-15  and 4.9-16.   Energy
consumption for the  incinerators can be very large, but  heat  re-
covery can help reduce this requirement.   Secondary pollutants  to
be considered are  combustion gases  from incineration which may
contain pollutants   such as NOV> SQ2 ,  CO, and acids.
                                362
-------
U>
                           TABLE  4.9-15.   INCINERATION  COSTS FOR A FABRIC  COATING  PLANTa'b-7°


Installed
COKI
No Meat
Thermal
$125,000
Recovery
' Catalytic
$155.000
Primary
Thermal
$150,000
Meat Recovery
Catalytic
$180,000
Primary acid Secondary
Thermal
$183,000
Heat Recovery
Catalytic
$220,000
                   Annuitized     $105,000        $100,000        $66,000          $75,000         $26,000         $54,000
                   Cost                   :                .                    '
                   'Costs are liased on several assumptions.  See original reference for liases.
                   ''2'iZ  Lower Explosive Limit.  400,Hm1/mfn (15,000 scfm)            :'
                              TABLE  4.9-16.   CARBON  ADSORPTION COSTS FOR  A  TYPICAL  FABRIC COATING
                                                  OPERATION3 '»> *»   .   •'
                                                                    Solvent Recovery Credit    Solvent Recovery Credit
                                                 No Solvent Recovery       at Fuel Valiu-        at Chemical Market Value
                                 ln.itn11rdCii.st       $320,000              $321), (100                  $120,000


                                 Animal Operating      $127,000              $ 60,000                  $100,000
                                 Cost
                                 * Cos I s art ha.'>fd on several asfiumpt Ions .   See or Ig Inn I refererice for Las PS .
                                 '2r>X l,(iwcr Kxjiloftlvt' Uwlt.  40(1 NmVmin  (lr),OOD ncfm)
                                    •             ~                      '.    '•  .'.*,   •
-------
          Also, if steam is used in the adsorption system to re-
generate carbon beds,  the condensate may need to be treated be-
fore disposal

4.9.3.4   Wood Furniture Coating

          Water-borne coatings are, at present, more expensive
per liter (gallon) than conventional coatings.  Material costs
for industrial use are about 10 percent higher per square meter
(square foot) of coated surface.72  Longer drying times for water-
borne coatings increase the energy requirements and costs for
industries employing drying ovens.73  The resultant slower pro-
duction rates also produce adverse economic effects.

          Some of the cost problems associated with water-borne
coatings are compensated by a reduction in plant insurance rates.
Reduced requirements for fresh air ventilation also reduce the
energy requirements and costs for plant heating or cooling.71t
Future research and development efforts may significantly affect
the economics of water-borne coatings.

4.9.4     References

1.  LeBras, L. R., PPG Industries, Pittsburg, Pa. Letter to
    Vera Gallagher dated August 13, 1976. As  cited in Envir-
    onmental Protection Agency.  Control of'Volatile Organic
    Emissions from Existing Stationary Sources-Volume II:  Sur-
    face Coating of Cans, Coils, Paper, Fabrics, Automobile,
    and Light Duty Trucks.  EPA-450/2-77-008.  May 1977.

2.  Schrantz, Joe, Hitchcock Publishing Co, Wheaton, II.  Letter
    to James McCarthy dated July 22, 1976.  As cited in EPA May
    1972.
                               364
-------
 3.  Johnson,  W.  R.,  G M Corporation,  Waren,  Mich.   Letter to
     James McCarthy  dated August 13,  1976.   As cited in EPA,  May
     1977.

 4.  Gallagher, V. N., EPA,  Research Triangle Park,. N. C.  Reports
     of trips  to various can coating facilities in 1975 and 1976.
     As cited in EPA, May, 1977.

 5.  National  Coil  Coaters Association; Fact Sheet 1974.  National
     Coil Coaters Association.  Philadelphia, Pa.

 6.  Environmental Protection Agency.   Control of Volatile Or-
     ganic Emissions from Existing Stationary Sources , Volume" III -.
     Surface Coating of Metal Furniture.EPA-450/2-77-032.  December
     1977.

 7.  Environmental Protection Agency.   Control of Volatile Organic
    -Emissions from  Existing Stationary Sources-Volume II:  Sur-
     face Coating of Cans, Coils, Paper,  Fa-ries, Automobile,
     and Light Duty-Trucks.   EPA-450/2-77-008.  May 1977.

 8.  Smith,  J....C. Coating-of Textiles. 'The Shirley Link. 'The
     Shirley Institute, England, pp.  23-27.

 9.  Reference 7,

10.  Johnson,  William L.  Environmental Protection Agency.  Re-
     search Triangle Park, N.C. _ Report of meeting with DuPont
     on August 10,  1976.

11.  DeVilbiss Educational Services.   Wood Finishing by Spray
     Process,
                                365
-------
   12.   Hughes,.!.  W.,  et  al.   Prioritization  of Sources  of Air
        Pollution from  Industrial Surface  Coating Operations.
        Monsanto Research  Corporation,  Dayton  Laboratory,  January
        15,  1975.

   13.   Estimating Emission Factors  for Solvent Use,  Memo from
        William L.  Johnson (EPA)  to  James  C.  Berry (EPA), Novem-
        ber  16, 1977.

   14.   Foster, D.  Snell,  Inc.   Air Pollution Control of Hydrocarbon
        Emissions - Metal Coating Operations - Section A.  November
        1976.

15-16.   Danielson,  J.  A. (Ed).   Air Pollution Engineering Manual.
        AP-40.  2nd Ed,  Environmental Protection Agency.  May 1973.

   17.   Reference 14.

   18.   Reference 7.            .

   19,   Reference 14.

   20.   Reference 7.

   21.   Radian Corporation, Austin, Texas.  Evaluation of a Carbon
        Adsorption Incineration Control System for Auto Assembly
        Plants.  EPA Contract No. 68-02-1319, Task No, 46.  January
        1976.  As cited in Reference 6.

   22.   Reference 4.

   23.   Ruff, R. J.  Catalytic Combustion in Wire Enameling.  Wire.
        October 1951.   Pages 936-940.  As cited in Air Pollution
        Control Technology Applicable to 26 Sources of Volatile
        Organic Compounds.  May 27, 1977.

                                   366
-------
24.   Kloppenburg, W. B.  Bebell and Richardson Trip Report No.
     106,  April 1976.   As cited in Air Pollution Control Tech-
     nology Applicable to 26 Sources of Volatile Organic Com-
     pounds.  May 27, 1977.

25.   Emission Test Reports from Metropolitan Office of Southern
     California Air Pollution Control District, No. C-2133, C-229.
     As cited in Air Pollution Control Technology Applicable to 2>
     Sources of Volatile Organic Compounds.  May 27, 1977.

26.   Reference 6.

27.   Reference 7,

28,   Emission Test Reports from Metropolitan Office of Southern
  - _'_ California Air Pollution Control District, No. C-213'3,' C-229:
     As cited in Air Pollution Control Technology Applicable to
     26 Sources of Volatile Organic Compounds.  May 27, 1977,

29.   Connelly, Herbert H.  What's New in Furniture Finishing?
     Furni-ture-Design  and Manufacturing.  April 1976.

30.   Reference 6,                    .          '

31.   Reference, .7.

32-   Scott  Research Laboratories.  A Study of  Gaseous  Emissions
     from the Coil Coating Process and Their Control,  Plustead-
     ville, Pa.  Prepared for the National Coil Association,
     October 1971.

33,   Reference 6.

34.   Reference 7.
                                367
-------
 35.  Reference 11.

 36.  Reference 29.

 37.  Johnson, William.  Environmental Protection Agency.  Re-
      search Triangle Park, N.C.  Report of meeting with Guards-
      man Chemicals, Inc. on Sept. 21, 1976.

 38.  Johnson, William.  Environmental Protection Agency.  Research
      Triangle Park, N.C.  Report of meeting with Reliance Univer-
      sal,  Inc. on  September 21, 1976.

'-41.  Reference 7.

 42.  Sussman, Victor H., Ford Motor Company,  Dearborn, Michigan,
      Letter to James McCarthy dated August  6,  1976  as  cited in
      Reference 7.

 43.  Radian Corporation.  Evaluation of a Carbon Adsorption In-
      cineration  Control System  for Auto Assembly Plants.  EPA
      Contract No.  68-02-1319, Task 46.  Austin, Texas.  January
      1976.  As cited  in Reference  7.

 44.  MSA'Research  Corporation,  Package -Sorption Device Systems
      Study, EPA-R2-73-202, April  1973.  As  cited in Reference 7.

 45.  Grandjacques, Bernard, Calgon Corporation.  Air Pollution
      Control and Energy Savings with Carbon Adsorption Systems,
      ACP 12-A, Pittsburgh, Pa., July 1975.  As cited in Ref-
      erence 7 .

 46.  Mueller, James H., Reeco,  Morris Plains,  New  Jersey.   Letter
      to James McCarthy  dated October 1, 1976.  As  cited in  Ref-
      erence 7 .

                                 368
-------
   47.  Combustion Engineering Air Preheater,  Report  of  Fuel  Re-
        quirements, Capital Cost and Operating Expense for  Catalytic
        and Thermal Afterburners.  EPA-450/3-76-031.  Willsville,
        New York, September   1976,  As  cited  in  Reference  7.

   48,  Reference 7.

49-50.  Reference 47.

51-52.  McCarthy, James A., U. S. Environmental  Protection  Agency,
        Research Triangle Park, N.C., Report  of  trip  to  General
        Mo-tors Assmbly Plants in South  Gate and  Van Nuys,  Califor-
.,  ' -••--..  nia.  .Report dated November 17,  1975.  As  cited  in  Ref-
        erence. 7...        ........            •             '  "       ..

53-53.  Reference 7.            '              •            - "  ^

   59.  Reference 6.

   60.  Economic Justification of Powder Coating.   Powder Finishing
        World.  Pages  18-22,  4th quarter,  1976.  As cited in Ref-
        erence 6.
                                      «•
                                       T
   61.  LeBras, Louis  R.  Technical, Director,  PPG  Industries, Inc.,.
                                   • •
        Pittsburgh, Pa.  Letter  to' Ife'ra Gallagher  dated September
        22, 1977.   As  cited in Reference 6.

62-63.  Reference 47 .

   64.  Anisfield,  J.   Powders Competition.   Canadian Paint and Fin-
        ishing,  December 1974.   As-cited in Reference 7.

65-68.  Reference  7.
                                   369
-------
   69.   Comparison of Alternatives by Incremental Basis-Cost per
        pound of Silicone Solids,  Dow-Corning,  Midland,  Mich.  As
        cited in Reference 7.

70-71.   Reference 7.

   72.   Reference 37.

   73.   Oge,  Marge T.,  Dubell  and Richardson, Inc.  Trip Report No.
        127,  April 15,  1976.

   74.   Water-borne Varnish Ends Solvent Problems in Furniture Finish-
        ing.   Industrial Finishing.  December 1976.  pp. 16, 17.
                                    370
-------
4.10      Robber and Rubber Products

          Rubber is an elastomer which can be processed
(vulcanized) into a material that can be stretched to at least
twice its original length and will return with force to approxi-
mately its original length when the stress is removed.  Synthe-
tic rubber is produced by polymerization or copolymerization
of monomers.  Raw materials used in the production of synthetic
elastomers include polymers of butadiene, styrene, ethylene,
propylene, isoprene, isobutylene, acrylonitrile, and chloro-  ••••
prene.  Products are marketed in both solid (crumb, or slab)  .
and liquid (latex) forms.  Natural rubber production is not''•••-
covered in this chapter.
          The total production of synthetic rubber for the
years 1974, 1975, and .1976 was  2.5 Tg  (5.5 x 109 Ib), 1.94 Tg
(4,3 x 109 Ib), and 2.3 Tg (5.1 x 109 Ib) , respectively.1 These
figures reflect the economic recession  of 1975 and the rubber
industry strike in 1976.  Tire production in 1972 accounted
for about 667. of that total.2  Organic  emissions and  control
technology-for synthetic rubber, rubber-products, and reclaimed
rubber production are discussed in Sections 4:10.1 and 4.10,3.

4.10.1    Synthetic Rubber3 ">

          Two processing technologies,  emulsion polymerization
and .solution- polymerization, are used in  the manufacture of
synthetic rubber.  Emulsion polymerization is the more widely
used process.  The production of crumb  styrene-butadiene (S3R)  .
by emulsion polymerization as described below is essentially
typical of all emulsion crumb processes.
                               371
-------
          Styrene and butadiene (monomers) are piped or shipped
to the plant and stored in a tank farm.  Inhibitors which pre-
vent premature polymerization are removed in a caustic scrubber
using a 20% NaOH solution.  Soap solution, catalyst, activator,
and modifier are then added to the monomer mixture.  The con-
tinuous polymerization process occurs in a series of reactors
which may produce "cold"  (4-7°C, 105-210 kPa) (40-45°F, 0-15
psig) or "hot" (50°C, 385-525 kPa)  (122°F, 40-60 psig) rubber.
For "cold" polymerization the emulsion is cooled prior to re-
action.  An inhibitor (shortstop) is added to the mixture leav-
ing the reactor to stop the polymerization.  Two common short-
stops are sodium dimethyl dithiocarbamate and hydroquinone.

          Unreacted monomers are recovered from the solution,
purified, and recycled.  Antioxidants are added to  the reactor
product and various recipes are mixed.  A dilute NaCl-H2SO,,
solution is used to precipitate the rubber.  Carbon black and
oil extenders may be added during the coagulation  step.  The
rubber is then separated on a shaker screen, rinsed with water,
dried, and pressed into bales. ..

          Latex production includes the same processing steps
as emulsion crumb production except for-the- coagulation, ,
rinsing, drying, and baling.

4.10.1.1  Emission Characteristics

         Fugitive volatile organic  emissions from  the  emulsion
crumb process and other industry processes are possible because
of leaking valves and seals.  Other gaseous emissions  arise  from
monomer and solvent recovery processes, from product drying,  and
from storage areas and tanks.  On   the basis of limited information,
                             '372
-------
  it  is  estimated volatile organic  emissions  average  41  g/kg
  product  (82  lb/ton).5  A breakdown  of  this  total  is given in
  Table  4.10-1.

  4.10.1.2   Controlt Techno 1 ogy

            Odor control is  accomplished by chemical, thermal,
  and catalytic oxidation; condensation; absorption with water
  scrubbers  and adsorption with  activated  charcoal.   Hydrocar-
  bons recovered-by adsorption are  sometimes  recycled.7

  4..-10.1.3   Cost, Energy, and Environmental Ijnpact _of Controls

            Cost, environmental-impact,  and energy  requirements
  for the  above controls are discussed in  Section 3/0.   Qrg-anies"
  recovered  by adsorption provide a cost credit  and 'an indirect
  energy credit.

            Oxidation controls have the  potential to  produce  NOX
  and CO emissions.   Organic emissions- may also  be  produced if
  incineration is not carried out properly.   Water  scrubbers
  produce  a  contaminated wastewater stream.   Without  extra waste-
  water  treatment,  the  potential exists  for pollution of the
  plant's water effluent stream.

  4,10,2    Rubber  Products9'9
	--,.    .    A wide variety of synthetic rubbers  is used for the
'"manufacture of tires  and other specialty products.   Most-pas-
  senger car tires are  made from SBR and 25% to  35% polybutadi-
  ene.10   Fillers,  extenders and reinforcers,  of which carbon
  black- and oil  are the most common,  are used co dilute the raw
  rubber iri order to produce a greater weight or volume and to
  increase the strength,  hardness,  and abrasion  resistance o£
  the  final product,
                               373
-------
TABLE 4.10-1.
EMISSIONS SUMMARY OF SYNTHETIC ELASTOMERS
PRODUCTION6
Source
Emulsion (90% of total production)
Styrene storage (breathing)
Solvent storage (fugitive)
Reactor section (fugitive)
Recovery area (fugitive)
Butadiene recovery
Coagulation, dewatering., drying
Solution (10% of total production)
Styrene storage (breathing)
Hexane storage (breathing)
Storage (fugitive)
Purification area (fugitive)
Reactor area (fugitive)
Desolventization (vent)
Desolventization (fugitive)
Dewatering, drying
Emission factor,
g/kg (Ib/ton) of
rubber produced

0.02
0.07
0.4
0.1
0.6
0.6

0.02
0.5
0.07
0.2
0.61
2.7
0.2
20.2

(0.04)
(0.14)
(0.8)
(0.2)
(1.2)
(1.2)

(0.04)
(1.0)
(0.14)
(0.4)
(1.2)
(5.4)
(0.4)
(40.4)
Percent total
emissions

0.4
1.5
8.9
2.3
13.3
13.3

0.05
1.2
0.25
0.6
1.6
6.6
0.6
49.4
                           374
-------
          Specialty rubber products include rubber footwear,
hose and belting; gaskets, packing and sealing devices; insu-
lated wire; and various other fabricated rubber products.  The
manufacture of rubber products involves compounding, calender-
ing, building of the product, and vulcanization.  The  steps are
similar to those in tire manufacture but they are practiced on
a smaller scale and with varying proportions of other  materials.

          Tires,_ Inner _Tubes u and Retreading

          Tire production employs a Banbury mixer to compound
the-rubber, carbon black, oil and other ingredients such  as
antioxidants, curing ag'ents, and catalysts.  Textiles,  cord,
and wire are dipped into a rubber .cement or latex dip  and •  ..
dried in an oven.  They are  then calendered (coated) with rub-
ber,'- The rubber -and coated materials are  then cut and molded
into the basic tire components.  The tire  tread is often  coated
with rubber cement or solvents to "tackify"" it before  it  is
built into a tire.  After the components have been assembled,
the green tire is sprayed with a release agent such as sili-
cons oil.  The 'tires are molded and cured  (vulcanized)  in an
automatic press at 38 to -149°C- (100 to 300°F) for periods of
fr"cM'-.a. few seconds ' to several minutes.

           Inner  tube manufacture proceeds  similarly except  that
the compounded rubber is extruded onto a continuous cylinder.
The tube is cut  to length and  the ends are spliced.   Inner  tubes
are cured  in the  same -nanner as  tires.

           Tire -retread  shops usually buy  the  tread  from tire
manufacturers and only  cementing, curing,  and buffing are done
                               375
-------
on-site.  New tread stock may also be extruded directly onto
the carcass.

          Rubber Footwear

          The rubber footwear industry includes the manufac-
ture of canvas footwear and waterproof footwear.  Canvas foot-
wear is the major product.  Canvas footwear production is on a
much smaller scale than is tire production,, as is the production
of all specialty rubber products.,

          In the mixer, white pigments are used in lieu of
carbon black and care must be taken to avoid discoloration.
The stock may be extruded as a strip or in a thin sheet.  Soles
and innersoles may be cut from sheets or formed by injection,
compression or transfer molding techniques.  The boxing between
sole and upper is extruded as a long strip.

          Canvas uppers are cut..atid sewn from several layers
of fabric which have been glued with latex and passed over a
heated drum.  The upper is cemented at its edges, then the shoe
is built on a last with a latex adhesive.  The shoe may be par-
tially or entirely dipped in latex, then air or oven dried.
The-shoe is cured at 30 to 40 psi  (207 to 276 kPa) for about
one hour with anhydrous ammonia.

          Hose and Belting

          Rubber hose consists of  three parts:  the lining,
the reinforcement (rubberized fabric) and the cover.  Rubber
belting consists of a rubberized fabric carcass sandwiched be-
tween layers of rubber sheeting.   Production steps include
compounding, calendering, reinforcement, extrusion, vulcani-
zing, and finishing.
                              376
-------
          After  compounding,  the rubber  stock  is  sheeted  for
 belting  or  extruded  to  form a tube  for hose.   Fabric  is cal-
 endered  and cut  on a bias.  The hose  or  belt is  then  built;
 the  hose is mounted  on  a mandrel  (metal  rod) for  support.
 Cement may  be  used for  adhesion of  the components.  Curing is
 carried  out in a steam  autoclave.

          Gaskets, Packing  and Sealing Devices

          Gaskets and packing and  sealing devices are made by
 three molding  techniques: compression, injection and  transfer.
 All  three techniques may be used  in one  plant.  Larger facili-
 ties, or those with  special needs,  compound their own stock.

          In compression molding  the  stock is  placed  in the
 mold and the two halves of  the mold are  held  together by  hy- .
 draulic  oil pressure during curing.  In  transfer molding  the
 stock is placed  in a transfer cavity  fitted with a ram.   The
 applied  force  of the ram plus heat  "from  the mold causes the
_rubber to soften and enter  the mold cavity, curing simultane-
 ously.   In  inj-ect-ion-molding  . the  stock  is injected into the
 mold cavity, then cured. ,''"'-

         - After  molding, rubber overflow is removed (deflash-
 ing) by  grinding, press-operated  dies, or tumbling in dry ice.

          Insulated  Wire

          Insulation is applied  to  wire  by extrusion.  The
 wire is  passed perpendicular  to  the extruder  so  that  the  rub-
 ber  compound completely surrounds  the wire.  The wire goes
 directly into  the curing device  for continuous vulcanization.
 Another  covering of  textile or metallic  braid, lead,  or anothe:
 rubber may  be  applied.
                              377
-------
          Other Fabricated Rubber Products

          Other fabricated rubber products include others which
are molded or extruded and those made of latex or rubber cement.
Latex is an emulsion of rubber in water; cement is a solution
of rubber in an organic solvent.  Latex and cement products
are usually formed by dipping a form into a bath, curing, then
stripping the item off of the form.

4.10.2.1  Emission Characteristics11'12

          The rubber products industry is based on mechanical
and dry manufacturing processes, therefore, organic emissions
are relatively low.  Potentially hazardous organic solid wastes
are not incinerated.  Volatile organic emissions are most likely from
the processes in which temperatures are high (above 72°C), par-
ticularly compounding, extrusion and vulcanization.  Rubber
adhesives,  solvent, cement, excess spray and spray residue,
etc.,  and other additives may be volatilized during vulcaniza-
tion.   There may also be leaks in materials storage areas.

          A summary of available volatile organic emission
data for tire, inner tube, and specialty rubber products manu-
facture is given in Table 4.10-2.

4.10.2.2  Control Technology

          The principal techniques used to control organic
emissions from rubber processing are reformulation, condensa-
tion,  adsorption, absorption, and incineration.  Direct-flame
incineration has proven to be very successful in controlling
both hydrocarbons and odors from rubber processes such as cord
drying.   Carbon adsorption and incineration have been used to
                             378
-------
                                  TABLE  4.:10-2.    VOLATILE  ORGANIC  EMISSIONS FROM RUBBER
                                                      PRODUCTS  MANUFACTURE13
                                                    g/kg (lb/1000 Ib)  product
VO
Process
in Tire Spraying
rlc Content lag
£ Building
; IT tread Cementing
id End Cementing
>er Cementing
Eing
ling
mlve Spruylug
»B
:x Pipping and Drying
lOiimtlng
ing
ndi'r Ing
UUlon
ting and Trimming
nt Spraying
ent Storage
.1.
. • Honf errous
Tire and Rubber Hose and Fabricated Rubber Caaketa, Wiredrawing Tire
Inner Tube Footwear Belting Rubber Good* Scale & Packing and Insulation Retreading
19.7
5b 12. 5b
3.6 , ,
l-«b i •'.'.,.
0.25"
95 6.0
2.0 ;
O.llb O.ll" 0.22
1.8 3.6
0.22 0.08b 0.16 • 0.08b . 0.6 0.09
O.I* ;' 0.13°
0.1 0.1 0.01 0.1 0.1 t
0.05 0.05 0.05 0.05 0.05
0.04a 0.05 0.05 0.025 0.05
0.01d 0.02b : 0.015b 0.04
3 .2
2.75
0.01
30.23 95.49 18.83 4.31 4.02 0.64 6.04
         Cm lug

         l.atex

         Com^io

         MUli

         (.'
-------
a very limited degree.  Control efficiencies as high as 97
percent have been achieved in one plant.  Adsorption is used
for the emissions from tread cementing.  Based on this infor-
mation, the potential reduction of volatile emissions in rub-
ber processing plants is estimated to be over 90 percent.
Water-based release agents have also been used successfully
as a substitute for the silicone oil.1*

4.ID.2.3  Cost, Energy, and Environmental Impact of Controls

          Cost and energy requirements are discussed in Section
3.0.  Recovered organics produce a cost credit and an indirect
energy credit.

          Incineration may produce NOX and CO emissions if not
properly operated.  Incineration of materials containing sulfur
may produce SOX emissions.

4.10.3    Reclaimed Rubber15 •'16'17

          The reclaiming of old tires  involves two steps -.
mechanical preparation and separation  of the rubber, and physi-
cochemical modification, usually called devulcanization.

          Devulcanizers are'of  two types:  the reclaimator and
the dynamic devulcanizer.  A reclaimator is a screw device
which generates high  temperature and pressure.  Reclaiming oils
are added to the rubber in the  reclaimator.  The dynamic devul-
canizer operates at steam pressures of 3.5 to 7 MPa  (500-1000
psia).

          The product from the  reclaimator is in the form of
thin flakes which can be processed into sheet or crumb  form.
                               380
-------
The material from the dynamic devulcanizer is further compoun-
ded on a mixing strainer, then passed through mills which pro-
duce a crumb form similar to synthetic rubber.

4.10,3.1  Emis s ion Character is tics

          In the reclaimator, lighter fractions of the reclaim-
ing oil are driven off.  When the hot oil is mixed with the water
used to cool it, the mist formed is 2 percent organics.  Similar
quantities of organics are emitted in the vent stream from the
dynamic devulcanizer.  Solvent may also be lost during addition
to, the dynamic devulcanizer.  Based on data obtained from state
permit applications for an assumed -representative rubber reclaim-
ing plant;" the" emission"factor is calculated  to be 30 g/kg (30
lb/1000 lb)' product.  'The emission factor will vary with each
type of process.19

4.10.3.2  Control Technology

          Emissions from the reclaimator are  controlled by
condensation and scrubbing.  In at least one  establishment the
recovered oil is recycled to the process.19   Steam pressure
from the. dynamic devulcanizer can be'relieved through control
equipment consisting of a venturi scrubber discharging to a
barometric condenser.  "Direct-flame incineration is also a
possible control technique, but it is generally considered too
costly.20

4 ,,10. 3. 3  Cost, Energy, and Environmental Impact of Controls

          Costs and energy requirements are discussed in Section
3.0.  Recovered oil provides a cost credit and an indirect energy
credit.
                               381
-------
          Incineration may produce NO  and CO emissions.   If
there is any sulfur in the reclaiming oil, incineration may
also produce SO  emissions.
     r         x

4.10.4    References

1.  Rubber Manufacturers Association.  As cited in Output of
    Most Major Chemical Products Bounced Back Last Year from
    Recession Lows.  C&EN 55 (23):44, June 6, 1977.

2.  Richardson, J., and M. Herbert.  Forecasting in the Rubber
    Industry.  (Presented at the Joint Meeting of the Chemical
    Marketing Research Association and the Commercial Develop-
    ment Association.  New York.  May 1974.)  As cited in
    Hoogheem, T. J., et al.  Identification and Control of
    Hydrocarbon Emissions from Rubber Processing Operations,
    Draft Report.  Monsanto Research Corporation, Dayton, Ohio.
    EPA Contract Number 68-02-1411, Task 17.  November 1977.

3.  Development Document for Effluent Limitation Guidelines
    and New Source" Performance Standards for the Tire and
    Synthetic Segment of the Rubber Processing Point Source
    Category.  Effluent Guidelines Division, Office of Air and
    Water Programs, U.S. Environmental Protection Agency.
    Washington, D.C.  1974.  193 p.

4.  Hoogheem, T.J., et al.  Identification and Control of
    Hydrocarbon Emissions from Rubber Processing Operations,
    Draft Report.  Monsanto Research Corporation, Dayton, Ohio.
    EPA Contract Number 68-02-1411, Task 17.  November 1977.

5.  Sittig, M.  Pollution Control in the Plastics and Rubber
    Industry.  Park Ridge, N.J., Noys Data Corporation, 1975.
    301 p.

                               382
-------
 6.   Reference 4.

 7.   Kenson,  Robert E,,  P,  W.  Kalika and S.  Cha.   Odor Sources
     in Rubber Processes and Their Control.   In:   Proceedings
     of Conference on Environmental Aspects  of Chemical Use in"
     Rubber Processing Operations  Held in Akron,  Ohio, on March
     12-14, 1975.   Prepared for Environmental Protection Agency.
     July 1975.   pp.  17-36.

 8.   Foster D. Snell, Inc.   Assessment of Industrial Hazardous
     Waste Practices, Rubber and Plastics Industry.   Prepared
     for United States Environmental Protection Agency, Washing-
     ton, D.C.  Contract No. 68-02-3194.  Feb. 1976.

 9.   Reference 4,

10.   Kirk-Ottmer Encyclopedia of Chemical Technology, Second
     Edition.  John Wiley and Sons, Inc.  New York.   1968.

11.   Reference 8.

12.   Reference 4.

13.   Reference 4.

14.   Reference 4.

15.   Reinhardt, R. C.  Environmental Aspects of Rubber Reclaim-
     ing and Recycling  (Manufacturing).  In:  Proceedings of
     Conference on Environmental Aspects of Chemical Use in
     Rubber Processing Operations Held in Akron, Ohio, on March
     12-14, 1975.   Prepared for Environmental Protection Agency.
     July 1975.  pp. 349-361.
                                383
-------
16.   LaGrone, B. D.,  and E. A. Gallert.  Environmental Aspects
     of Reclaiming and Recycling Rubber.  In:  Proceedings of
     Conference on Environmental Aspects of"Chemical 'Use in
     Rubber Processing Operations Held in Akron, Ohio, on March
     12-14, 1975.  Prepared for Environmental Protection Agency
     July 1975.  pp.  315-348.

17,   Reference 8.

18.   Reference 4.

19.   Reference 8.

20.   Reference 15.
                                384
-------
4.11      Pharmaceut1caIs

          The pharmaceutical industry produces drugs, enzymes,
hormones, vaccines, and blood fractions.   The main processes
used in the industry are fermentation, organic and inorganic syn-
thesis, biological extraction and fractionation, and botanical
extraction.

          Organic emissions consist mainly of solvent used in
manufacturing processes.  Solvents commonly used are acetone,
acetonitrile, amylacetate, benzene, butyl acetate, chlorofomt*'
ethanol, ethylene dichloride, isopropyl alcohol, methanol, methyl
isobutyl ketone, toluene, xylene, ethylene glycol, tnonomethyl
ether, heptane, methylene chloride, and naphtha.1

          Emissions and control technology for fermentation,
drug synthesis, and biological and botanical extraction operations
are described in Sections 4.11.1 through 4,11.3.

4.11.1    Ferae_nt^tion

          Biological fermentation is used in the' pharmaceutical
industry to produce antibiotics.  In 1974 estimated  domestic
sales of antibiotics was  $760 million.2  Figure 4.11-1 illus-
trates the processing steps  in antibiotic production.  Living
microorganisms  such as  fungi or bacteria are cultured in  a
nutrient rich, broth.  The crude antibiotic is recovered by  ex-
traction, precipitation,  or  adsorption,.  The product is then
purified by several recrystallization steps, filtered and dried.  .
Product modification may  be  required prior to- the drying  step.
An example of product modification is the conversion of penicillin
to procaine penicillin.
                               385
-------
      VMW-
      i MOIA
       MtD
      GUITURI "
BIACTOB



HOT ART
rnnR
t


*— '
jS
tl


i!
a

CO
bo
                     CELLULAR
                     IMTIMAL
                     IX8POSA1.
GRVSTALUtATIOH
                Figure 4.11-1.   Simplified flow diagram for  antibiotic production.
-------
4.11.1.1  Emission Characteristics

          Significant volatile organic emissions arise during
extracting procedures and fermentation.   The fermentation pro-
cess produces gaseous by-products which are vented.   The vent
gases have a very strong odor but contain low concentrations
of volatile organics.1*

          Solvent emissions result from evaporation of solvent
during processing and drying.  Another potential emission source
is evaporation of waste solvent.  The volume amount of solvent
emissions depends on the control methods used.  Waste solvent
is usually disposed of by incineration.   Table 4.11-1 lists
typical waste solvent values for the production of procaine pen-
icillin G.  In 1973, 12 Gg (26 x 106 Ib) of waste solvent con-
centrate was produced by fermentation operations.5  Of this
total, 5 Gg (11 x 106 Ibs) were incinerated on site.  The balance
was sent to outside contractors for disposal.  Some organic
vapors may be emitted from the on-site incineration.

          TABLE 4.11-1.  SOLVENT WASTES FROM PRODUCTION
                         OF PROCAINE PENICILLIN G6
                                 m3/Mg             gal/1000 Ib
Solvent Waste Concentrate       Product              Product
Solvent  (butyl acetate)           0.6                   72
Other Dissolved Organics          0.6                   72
      Total                       l'2                  144
                                387 '
-------
          Solvent losses from sources other than waste solvent
disposal depend on the equipment,  type of solvent,  and control
devices in use.

4.11.1.2  Control Technology

          Wet scrubbing carbon adsorption, and ozonation are po-
tential control methods for fermentation vent odors,  although
their use has been limited.  Incineration, though,  has been
demonstrated as very effective.  Fermentation vent gas has been
successfully used as combustion air in plant boilers.7

4.11.1.3  Cost,  Energy, and Environmental Impact of Controls

          Incineration is discussed in Section 3.1.

4.11.2    Synthesized Drugs

          Synthesis of organic medicinals may involve the com-
plete synthesis of a complex chemical such as aspirin or a one-
step modification of an antibiotic or botanical or biological
extract.  Production of specific organic medicinals can be large
or small.  Only 0.9-1.8 Mg  (1-2 tons) of a specialty drug may
be produced per year.8  Large volume drugs, such as aspirin, are
produced on a scale of 13.6 Gg/yr  (30 xlO6 lbs/yr).9  Batch pro-
cessing methods are employed.  Average yields and number of pro-
cessing steps vary considerably.  The aspirin production process
employs 2 steps and an 807. yield is achieved.  Vitamin A synthe-
sis requires 13 steps and has an overall yield of 15 to 20 per-
cent.

          Synthesized inorganic medicinals include antacids and
laxatives.  Both are usually compounded from magnesium hydroxide
or aluminum hydroxide, which are precipitated from solutions of
soluble magnesium and aluminum salts.  Since organic compounds
                               383
-------
are not used in their preparation, there are no organic hydro-
carbon emissions.   Further discussion of synthesized medicinals
will apply only to organic compounds.

4.11.2.1  Emissions Characteristics

          Total emissions depend on the solvents used, manufac-
turing processes,  and the type of control technology employed.
Organic emissions  come from evaporation of waste solvents as
well as from in-process losses.   The average organic medicinal
plant produces 100 kg (220 Ibs)  of waste halogenated solvent
and 700 kg (1,500  Ibs) nonhalogenated solvent per Mg (2,200 Ibs)
of product.1"  For 1973, solvent wastes from synthetic organic
medicinal plants were estimated to be 3.4 Gg (7.5 x 10s Ibs) and
23.8 Gg (52.4 x 106 Ibs), respectively.  Emissions occur when the
waste solvents are incinerated on-site.  The rest is sent to in-
dependent contractors for disposal.11

          In-process solvent losses also occur.  Because of the
varied nature of the different drug syntheses, no definite
sources can be given, although they might include such operations
as distillation, drying, and filtration.  Emissions are probably
similar to process losses from the organic chemical industry.

•4.11.2.2  Control Technology

          It has been reported that all waste solvents are incin-
erated.  An estimated 10.1 Gg/yr  (22 x 106 Ibs) are incinerated
on site.    The rest is sent to off-site contractors.

          Processing solvent losses can be controlled in a num-
ber of ways, depending upon the particular process parameters.
                               389
-------
4.11.2.3  Cost, Energ^, and~"^nvlronmental Impact of Controls

          Incineration is discussed in Section 3.1.

4.11.3    Biological Extractions and Fractionation

          There are three major methods for producing medicinals
from animal products:  extraction, fractionation, and precipita-
tion.  Drugs produced include insulin, heparin, vaccines, var-
ious serums, toxoids, and blood fractions.

          Extraction is used to obtain hormones or enzymes from
animal tissues.  Beef and hog pancreas are used for insulin;
heparin is obtained from lung tissue.  Figure 4.11-2 shows a
simplified production scheme for obtaining insulin.  The ground
organs are first treated with acidic alcohol  (ethanol or meth-
anol).  The extract is recovered by centrifugation or filtration,
neutralized, then filtered again to remove precipitated protein.
The extract is then acidified again, concentrated, treated to
remove fats, and clarified.  The crude insulin is finally pre-
cipitated with NaCl.  Further purification may include iso-
electric precipitation.

          Precipitation and fractionation are generally used to
produce vaccines, toxoids, serum, and blood fractions.  Vaccine
viruses such as influenza virus are cultured in fertile chicken
eggs.  The antigen is then extracted from the egg with a salt
solution and precipitated with ammonium sulfate.  Toxoids such
as poliomyelitis toxoid are recovered from formaldehyde treatment
of culture media previously innoculated with a virus.

          Serum and blood fractions are all derived from whole
blood.   Serums, such as tetanus anti-serum, can be obtained
from horse blood, but blood fractions are produced only from
                               390
-------
vo
| 	 	 •« HUT
-

IITHUTIDH
	 ~

CENT
so

«,

•«*«,,<«
— ~


AND
FKTIUTION



— *

t
VINT
p.
*•>
EVAPOHATIO*


	 „
r
i
MlH
TANK

•IX. VI NT
KtcavtsY


10l«IT
ttM
FMtAWOttl
—
Ktm
•HO
or cmjoe


PPtK

•OtVCMT

DIM01VHM
MCOVfKY
•V
IMCIICTW:





«a*ot««ra
AMD
•LM.H

romwunoH

              Figure 4.11-2.  Simplified production  scheme  for  insulin,13
-------
human blood.  Useful protein fractions include gamma-globulins,
thrombin, albumin, and antihemophilic globulin.  These fractions
are obtained by first centrifuging whole blood to obtain the
plasma.  Protein fractions are then precipitated with ethanol
of various  concentrations and at varying conditions of pH.1*

4.11.3.1  Emission Characteristics

          Organic emissions result from the use of solvents.
Waste organic solvents in 1973 for biological medicinals were
estimated to total 1.05 Gg  (2.31 x 10B Ibs)  (see Table 4.11-2).
Waste solvent is generally  incinerated, although a small amount
from extraction processes is sent to wastewater treatment  facil-
ities.15   (See Section 4.15, Waste Handling  and Treatment.)
Process emissions of solvent vapors also may occur.

   TABLE 4.11-2-  WASTE SOLVENTS FROM BIOLOGICAL MEDICINALS16

                                  Mg of Waste
     Source of Solvents            (Dry Basis)       106 Ibs
Medicinals from Animal Glands
(may be up to 50% water)
Ethanol from Blood
Fractionation
TOTAL

800

250
1,050

1.76

.55
2.31
4.11.3.2  Control Technology

          As stated above, waste organic solvents are usually
incinerated, with a small portion sent: to biological wastewater
treatment facilities.  Control techniques for process vapor losses
were not specified, and depend on the manufacturing equipment.
                               392
-------
4.11:3.3  Cost, Energy, and Environmental Impact of Controls

          Incineration is discussed in Section 3.1.

4.11.4    Botanical Extractions

          Certain types of secondary organic compounds from
plants can be extracted and used as Pharmaceuticals.  Alkaloids,
steroids, and various other compounds can be extracted from bark,
leaves, roots, and fruits.

          The medicinal is usually extracted from the dried   ""
plant material with an acidified, water-miscible solvent such. ••""'
a's" an alcohol.  This liquid is extracted with a water-injaiiscrble
solvent, such as ethylene dichloride.  The crude product "is then
recovered by vacuum evaporation and purified by crystallization,
precipitation, ion exchange, or chromatography.l7

          A different extraction technique is used  for preparing
steroids.  The production of, stigmasterol from  soybeans  is typi-
cal.  Still .bottoms from soybean oil refining are dissolved in  a
mixture ofrtiot hexane  (377,) and ethylene dichloride  (6370)".  After
a series of crystallizations,  the solvent is removed in  a vacuum
oven.  The stigmasterol crystals are about 9770  pure.13

4.11.4.1  Emissions Characteristics

          Organic emissions arise from waste solvent streams
and process vapor losses.  Table 4.11-3 lists typical solvent
waste streams for alkaloid extractions.  Waste solvents are
usually incinerated to prevent organic emissions.
                               393
-------
     TABLE 4.11-3.  SOLVENT WASTES FROM ALKALOID EXTRACTION
                                                           1 9
             Hazardous Waste               kg/kg  (Ib/lb) Product

        Halogenated Solvent                  9
        Methanol-water Concentrate         120
        Nonhalogenated Solvent              20
  4.11.4.2   Control Technology

            In  1973 an  estimated  1.2 Gg  (2.6 x  106 Ibs) of waste
  solvent was generated from botanical extractions.  Incineration
  was  used  to control emissions.   60% of waste  solvent was sent
  to off-site contractors.20  Control technology used to  curtail
  solvent vapor losses  depends  on process parameters and  the  types
  of solvent used.

  4.11.4.3   Cost, Energy,  and Environmental Impact of Controls

            Incineration is discussed in Section 3.1.

  4.11.5     Formulations

            The formulation of  Pharmaceuticals  involves making  the
  product into  tablet,  capsule, liquid,  or ointment  form  and  pack-
  aging for marketing.   Organics  are probably emitted from  this
  operation, but no data are available  at present.

  4.11.6    References

1-2.   McMahan,  J.R.,  N.J. Cunninhgam,  L.R.  Woodland, and D.  Lam
      Lambros.   Hazardous Waste Generation Treatment,  and Disposal
      in the Pharmaceutical Industry.   Environmental Protection
      Agency,  Office  of Waste  Management Programs.   Washington,
      D.C.   EPA Number 68-02-2684.  July 1975.   188 p. .
                                  394
-------
    3.   Van  Nostrand's  Scientific  Encyclopedia.   Princeton,  New
        Jersey,  D.  Van  Nostrand Company,  Inc.,  1968.   p.  558-559.

    4.   Lund,  H.  F.  Industrial Pollution  Control Handbook,  New
        York,  McGraw Hill,  1971.

  5-6.   Reference 1.

    6.   Overview Matrix.  Monsanto Research Corporation.   Dayton,
        Ohio.   Contract Number 68-02-1874.   July 1975.  35 p.

    7.   Reference 4.

    8.   Reference 1.

    9-   Chemical Profile:  Aspirin.  Chemical Marketing Reporter.
        October 3, 1977.
10-19,   Reference 1.

   20.   Chemical Origins and Makets.   Stanford Research Institute,
        Menlo Park,  California.   1967.   p.  83.
                                   395
-------
4.12      Graphic Arts

          The graphic arts industry includes about 40,OOU
establishments, most of which are small operations.  About
half employ less than 100 people,1  The industry includes
the printing of newspapers, books and magazines, cans,  sheet
metal, floor and wall coverings, and fabrics.  About half of
the establishments are in-house printing services in non-
printing industries.2

4.12.1    Process Descriptions

          Direct printing is the transfer of an image
directly from an image surface to the print surface; offset
printing involves the use of an intermediate surface.  Material
to be printed may be web-fed to the press from a roll and
remain continuous throughout the printing operation, as with
some paper and fabrics; or it may be fed in individual items
or sheets.  Emission characteristics depend mainly upon the
solvent content of the ink.

          There are five types of printing processes which
vary according to the nature of the image surface.  Letterpress,
flexography, lithography, gravure, and screen process print-
ing are described in the following Sections.

4.12.1.1  Letterpress

          Letterpress is the original printing process, in
which ink is applied to a raised image surface and  transferred
to the print surface.  Many small printers who still use  the
letterpress process work with sheet-fed equipment.
                             396
-------
           The  newspaper .industry uses  the web  letterpress.   The
 ink is made of carbon black and  oils which  are absorbed by  the
 porous paper and  thus present no emission problems.   Emissions
 of inert  ink mist and paper dust are controlled by air  condi-
 tioning. 3

           Conventional letterpress  inks  for nonporous paper
 contain 30 to  45  percent  organic solvent.   Drying occurs by
 solvent evaporation in a  drying  tunnel. /The solvent in high-
 speed operations  generally is a  selected petroleum fraction
 akin to kerosene  and fuel oil with  a boiling point of 200-
 370'C (400-700°F) ." 1 Low-speed operations use  a slow-drying  ......
 alkyd or  vegetable oil which dries  by  oxidation .or polymeri-
 zation. 5                                                 •

•;4 .'12.1.2   Flexography

           When the plates used in the  letterpress process are
 rubber, the process is known as  flexography.  It is widely used
 in'multicolor  printing on a variety of 'surfaces .6

          : Inks for flexography must be very fluid, typically about
 60?<, solvent, and  must not damage the ...rubber.  They dry  by solvent
 evaporation, usually at temperatures below  120°C (250°F).  Typical
 solvents  are alcohols, glycols,  esters,  ketones and ethers.  Some
 flexography inks  are more viscous than others.

 4.12,1.3   Lithography'

           In  lithography the printing  and nonprinting surfaces
 are on  the same plane.  The image area is made of material
 that can  only  be  wet by ink and  the non-image  area is "made o£
 material  that  can only be wet  by water.  The plates are first
                              3S7
-------
wet with water containing 0 to 30 percent isopropanol, then
with ink.7  Most lithographic operations are web-offset.  The
sheet-fed lithographic process is widely used for small and
large applications.  Most plants classified under commercial
lithography operate with sheet-fed lithographic equipment.

          Inks used for web-offset lithography must dry within
one second to avoid smudging as the web moves rapidly through
other operations.  "Heat-set" inks developed for this appli-
cation contain 35 to 45 percent petroleum hydrocarbons and
are dried at 200-260°C (400-500°F) ,8

4.12.1.. 4  Gravure

          The image area of a gravure press is recessed rela-
tive to the nonimage area.  A very fluid ink fills the image
area and is scraped off the nonimage area with a "doctor
knife".  The image is transferred directly to the printing
surface.  When the process is roll-fed, it is known as "roto-
gravure". 9   Sheet-fed gravure. is not widely used.

          Rotogravure inks contain 40 to 80 percent solvent
which may be an alcohol, aliphatic naphtha, aromatic hydro-
carbon, ester, glycol-ether, ketone, nitroparaffin or water.
The inks are dried at 38-120°C (100-250°F).1°

4.12.1.5  Screen Process Printing

          In screen process printing a  fine screen is used as  the
image area, and nonimage areas are masked off.  Inks similar to
the more viscous flexographic inks are  forced through the pores
of the image area onto the print surface.11
                               398
-------
          Screen process inks contain 20 to 50 percent solvent.
Drying is doh'e either at. room temperature or in an oven.  Sol-
vents include aliphatic hydrocarbons, aromatic hydrocarbons,
or oxygenated solvents.  Oxygenated solvents such as esters,
ethers, glycol ethers, and ketones are widely used.12  Screen
printing operations are generally small operations.

4.12.2    Emission Characteristics

          The main source of organic emissions from printing
establishments is the release of ink solvent during drying.
Solvent may be released to the atmosphere during ink application
in the flexographic and gravure processes.13  These emissions  ...  -
are controlled at some plants.  The most common odorants are
alcohols and partially .oxidized alcohols such as ketones.*"
There is a linear relationship between ink  consumption  and
emission rates.

          Low levels of organic emissions are derived from  the
paper stock during drying.  The type of paper, coated or uncoated,
has little--effect on the quantity of emissions.  The chemical
composition of-the emissions, however, will vary.15

          To-tal  annual emissions from  the industry  are  estimated
to be 360 Gg  (400,000  tons).  These  emissions are assumed  to be
hydrocarbons  or  organic solvents.  No  methane is emitted.   Of
this total, lithography processes emit 257,, letterpress 207»,
gravure 407.,  and flexography  15%.16

4.12.3    Control Technology

          Emission controls for the  printing  industry include  re-
moval of the  solvent vapors from the effluent by incineration  or
adsorption and/or use  of a  low  solvent ink.  Specific control
techniques are not applicable to all processes.

                              399
-------
          Incineration is used for web-offset lithography, letter-
press and small rotogravure operations.  The effective temperature
for thermal incineration ranges from 590 to 830°C (1100-1500°F).l7
The optimum range is usually 650-760°C (1200-1400°F).   N0x emis-
sions become a problem at higher temperatures.  Efficiency of vol-
atile organic removal is about 95%.18  Besides initial equipment
instaTtaTion costs, the major experfse is for fuel.  Heat exchangers
may be incorporated into the design,  so that waste heat can be used
to heat the drying ovens.  With this design fuel costs for in-
cineration may be reduced as much as 70%, but equipment costs
will be higher.19

          The application of catalytic incinerators also reduces
the fuel costs associated with incineration.  Temperatures range
from 330-510°C (625-950°F).*°  The most common catalyst is a
platinum and/or palladium-coated ceramic pellet, but other tran-
sition metals or their oxides are also used.  The catalyst may
be irreversibly poisoned by heavy metals, halogenated hydrocar-
bons, or organosilicon compounds, or it may be thermally aged
by excess heat.  The use of heat exchangers will further reduce
fuel costs. 21  Efficiency of the heat exchangers is 90 to 95
percent,, 22

          Carbon adsorption is an especially successful volatile
organic control technique at large rotogravure plants where sim-
ple mixtures of water-immiscible solvents are used.  A 90%
recovery rate can be achieved.23  The carbon bed is regenerated
with steam.  If the recovered solvent cannot be reused, it can
be sold to other industries.21*

          Low-solvent inks have been developed which are set by
thermal catalysis, ultraviolet light, or electron beam.  Ther-
mally catalyzed inks for heat-set letterpress and lithography
                              400
-------
contain up to "30% solvent -and use the same dryers as conventional
inks, but they cost 40 to 100 percent more.  The ink is set by
the polymerization of monomers and prepolymers with heat and a
catalyst.  The use of these inks requires a 1570 increase in fuel
costs.25  The higher temperature required to cure these inks causes
degradation of the paper.  This factor coupled with instability
of the inks on the press has led to the conclusion that heat cata-
lyzed inks are not a viable printing method.26

          Substitution of inks which polymerize upon exposure to
ultraviolet .light is a potential control method for sheet and web-
fed offset lithography.  Though UV setting inks cost 85 to 100
percent more than conventional, inks and new equipment must be pur-.
chased-, their use has. several advantages.  Emission control equip-
ment is not required, drying equipment is simplified, energy cos"ts
are reduced and ink does not dry in equipment during shutdowns.
However, workers must be protected from the UV radiation and from
the inks, which are skin and eye irritants.27'28  No commercial
application of UV inks has been developed for flexography or
gravure.2 9

          Waterb-orne inks contain up to 20% water soluble sol-
vent.  They cannot be used in lithography, and their use in
other areas Is limited.30  They are used in letterpress, flexo-
graphy, and some.gravure operations.  Microwave drying may eli-
minate the problem of the high heat of vaporization and make
these inks mere feasible in the future.31

          Another approach to the pollution problem is web-  '
heatset printing in the use of a "press coating" which seals
all the ink components onto the paper.  The use of this method
eliminates the need for oven drying.  Press coating can also be
used in letterpress or offset operations if the paper is srcooth.3~
                               401
-------
4.12. <';    Cost, Energy, and Environmental Impact of Controls

          Information is provided above in Section 4.12.3.   Addi-
tional information on incineration and adsorption can be found in
Sections 3.1 and 3.2, respectively.

4.12.5    References

1.  Schaeffer, W. D.  Session Introduction In;  Conference on
    Environmental Aspects of Chemical Use in Printing Opera-
    tions (Sept. 1975, King of Prussia, Pa.).  U.S. Environ-
    mental Protection Agency.  Washington B.C.  EPA Contract
    No. 68-01-2928.  January 1976.  pp. 106-110.

2.  Gadomski,  R. R. , et al . , Evaluation of Emissions and Con-
    trol Technologies in the Graphic Arts Industries, Phase I.
    Graphic Arts Technical  Institute.  August 1970.  As cited
    in Preliminary Report on Graphic Arts Industry.  EPA un-
    published  draft document.

3.  Carpenter,  B.H. and G.K. Milliard.  Overview of Printing
    Processes  and Chemicals Used.  In:  Conference on
    Environmental Aspects of Chemical Use in  Printing Opera-
    tions (Sept. 1975, King of Prussia, Pa.).  U.S. Environ-
    mental Protection Agency.  Washington, D.C.  EPA Contract
    No. 68-01-2928.  January 1976.  pp. 5-31.
4.  Fremgen, R. D,  Monitoring and Testing of Effluents
    Letterpress and Offset Printing Operations.  In:  Confer-
    ence  on Environmental Aspects of  Chemical Use  in Printing
    Operations  (Sept.  1975, King of Prussia, Pa.).  U. S.
    Environmental  Protection Agency.  Washington D.C.  EPA
    Contract No. 68-01-2928.  January 1976.  pp. 283-302.
                               402
-------
  5.   Reference 3.

  6.   MSA Research Corporation.   Package Sorption Device System
      Study.   Prepared for Office of Research and Monitoring,
      Environmental Protection Agency.   April 1973.   pp. 1-39 to
      1-43.

7-9.   Reference 3.

 10.   George, H. F. Gravure Industry's  Environmental Program.
      In*.  Conference on Environmental  Aspects of Chemical Use
      In Printing Operations (Sept. 1975,. King of Prussia, Pa.).. -
      U.S. Environmental Protection Agency.  Washington, B.C.
      EPA Contract No. 68-01-2928.  January 1976.  pp. 204-216.

 11.,  Reference 3.

 12.   Call,  F., Jr.  Environmental Impacts of Chemicals Used in
      Screen Printing Inks,  In-.  Conference on Environmental
   -.Aspects of Chemical Use in Printing Operations (Sept. 1975,
      King of Prussia, Pa)";  U'.'S. Environmental Protection Agency.
      Washington D.C.  EPA Contract No, 68-02-2928.   January
   ..... 1976.   pp.- 198-202.

 13.   Reference 6.

 14.   Bollyky, L. J.  Odor Control with Ozone Treatment.   In:
      Proceedings of  the Second Graphic Arts Technical  Foundation
      Conference on Air Quality Control in the Printing Industry.
      David, M. P.  (ed.).  Graphic Arts Technical Foundation.
      Pittsburgh, Pa.  Oct. 23-24, 1972.  pp. 36-47.
                                 403
-------
15.   Gadomski,  R.   GATF Studies of Hydrocarbon Emissions  from
     Web Offset.   In:   Proceedings of the Second Graphic  Arts
     Technical  Foundation Conference on Air Quality Control
     in the Printing Industry.   David,  M.  P.  (ed.).   Graphic
     Arts Technical Foundation.  Pittsburgh,  Pa.  Oct.  23-24,
     1972.   pp.  63-67.

16.   Gadomski,  R.  R.,  et al.,  Evaluations of Emissions  and Con-
     trol Technologies in the  Graphic Arts Industries,  Phase  II,
     Graphic Arts  Technical Institute.   May 1973.  As cited in
     EPA draft  documents.

17.   Control of Volatile Organic Emissions from Existing
     Stationary Sources - Volume 1:  Control Methods from Sur-
     face Coating Operations.   U.S. Environmental Protection
     Agency.  Research Triangle Park, N.C.  1976.  p. 39.

18.   Gadomski,  R.   Emission Control by Incineration in Web Off-
     set and Metal Decorating.  In:  Proceedings of-the Second
     Graphic Arts  Technical Foundation Conference on Air Quality
     Control in the Printing Industry.   David, M. P. (ed.).
     Graphic Arts  Technical Foundation.  Pittsburgh, Pa.   Oct.
     23-24, 1972.   pp. 68-73.

19.   Zborovsky, J. L.   Current Status of Web Heatset Emission
     Cpntrol Technology.  In:   Conference on Environmental
     Aspects of Chemical Use in Printing Operations  (Sept. 1975,
     King of Prussia,  Pa.).  U.S. Environmental Protection
     Agency.  Washington D.C.   EPA Contract No. 68-01-2928.
     January 1976.  pp. 261-282.

20.   Gadomski,  R.  R.,  et al, Evaluations of Emissions and Con-
     trol Techniques in the Graphic Arts Industries, Phase II.
     Environmental Protection Agency, Research Triangle Park,
     N.C.  1973.  p. 145.
-------
21,   Reference 19.

22,   Kroehling, J.  H.  Catalytic Fume Abatement of Gaseous
     Effluents in the Graphic Arts Industry.   In:  Proceedings
     of the Second Graphic Arts Technical Foundation Conference
     on Air Quality Control in the Printing Industry.  David,
     M. P. (ed,).  Graphic Arts Technical Foundation.  Pittsburgh
     Pa.  Oct. 23-24, 1972.  pp. 98-103.

23.   Reference 10.

24.   Environmental Aspects of Chemical Use in Printing Operations.
     EPA-5601/1-75-005.  Office of Toxic Substances, Environmental
     Protection Agency, January 1976.  As cited in Preliminary
     Report on Graphic Arts Industry, EPA draft document.

25.   Reference 19.

26.   .Vincent, E.' J. ,  Environmental Protection Agency.  Telephone
     communication with Dr. William Schaeffer,,, Director of lie-
     search, Graphic Arts Foundation.  October "3, 1977.

27.   Environmental Aspects of Chemical Use in Printing Operations,
     1976,,. , As cited in Preliminary Report on Graphic Arts Indus-
     try.  EPA draft document.

28.   Rocap, W. A., Moderator.  Current Status of Ultraviolet
     Drying Systems,  Panel Discussion.  In:  Proceedings of  the •
     Second Graphic Arts Technical Foundation Conference on Air.,
     Quality Control in the Printing Industry.  David, M. ?.
     (ed.)  Graphic Arts Technical Foundation.  Pittsburgh, Pa.
     Oct. 23-24, .1972..  pp. 117-139.
                                405
-------
29.   Schaeffer,  William D.,  Director of Research Department,
     Graphic Arts Institute, in letter to Don Goodwin, EPA,  RTF,
     dated September 12, 1977.

30.   Strauss, Victor. The Printing Industry.  Printing Industries
     of America, Inc., Washington, D.C. 1967.  As cited in Prs-
     liminary Report on Graphic Arts Industry.  EPA draft document.

31.   Gadomski, R.R., M. P.  David, and G. A. Blahut.  Evalua-
     tions of Emissions and Control Technologies in the Graphic
     Arts Industries, Final Technical Report.  Department of
     Health, Education and Welfare.  Public Health Service,
     National Air Pollution Control Administration.  Cincinnati,
     Oh.  Contract No. CPA 22-69-72.  1970.

32.   Rocap, W. A.  Press Coatings.  In:  Proceedings of the
     Second Graphic Arts Technical Foundation Conference on Air
     Quality Control in the Printing Industry.  David, M. P.
     (ed.)  Graphic Arts Technical Foundation.  Pittsburgh,  Pa.
     Oct. 23-24, 1972.  pp. 90-97.
                               406
-------
4.13      Stationary Fuel Combustion

          Stationary fuel combustion sources may utilize ex-
ternal or internal combustion.  External combustion sources
include boilers for steam generation, heaters for the heating
of process streams, and driers and kilns for the curing of
products.  Internal combustion sources include gas turbines
and reciprocating internal combustion engines.

4.13.1    Stationary External Combustion Sources

 •••-.. •     External combustion'sources are categorized according.
to thfe type "of fuel burned in the unit.  Coal, fuel oil, and-
natural gas are the primary fuels use-d in stationary external ...
combustion units.  LPG, wood and other cellulose materials are
also used to a lesser degree in external combustion sources.
The largest market for liquified petroleum gas, LPG, is the
domestic-commercial market, followed by the chemical industry
and the internal combustion engine.

          Bituminous coal is the most abundant fossil fuel in
the United States.  Capacities of coal-fired furnaces range
from 4.5 kg (10 Ib) to 360 Mg (400 tons) of coal per hour.
Approximately 480. Tg (530 x 10s. tons) were consumed in  1972  to
supply thermal energy in the United States.1

          Anthracite coal is used in some industrial and in-
stitutional boilers and'is widely, used in hand-fired furnaces.
It has a low volatile content and a relatively high ignition
temperature.                                  •                 -

          Lignite  is a geologically young coal with properties
that, are intermediate to- those, of bituminous coal and peat.
                              407
-------
Lignite has a high moisture content 35 to 40 percent by weight
and the heating value of 1.5 - 1.8 J/kg (6000-7500 Btu/lb) is
low on a wet basis.  It is generally burned in the vicinity of
where it is mined.  Although a small amount is used in indus-
trial and domestic applications, it is mainly used for steam
production in electric power plants.

          The two major types of fuel oil are residual and dis-
tillate.  Distillate oil is primarily a domestic fuel, but it
is used in commercial and industrial applications where high-
quality oil is required.  Residual oils are produced from the
residue remaining after the lighter fractions (gasoline,
kerosene and distillate oils) have been removed from the crude
oil.  More viscous and less volatile than distillate oil,
residual oils must be heated for easier handling and for proper
combustion.  Residual oils also have higher ash and sulfur
contents.

          Natural gas is used mainly for industrial process
steam and heat production and for space heating.  It consists
primarily of methane with varying amounts of ethane and smaller
amounts of nitrogen, helium, and carbon dioxide.  In 1974, 616
km3 (22 trillion ft3) of natural gas were marketed in the
United States, the majority of which was used as fuel.2

          Wood is no longer a major energy source for indus-
trial heat or power generation.  However, it is still used to
some extent in industries which generate considerable quanti-
ties of wood/bark wastes.  Wood is also used as a domestic heat
source.  Wood/bark waste may include large pieces such as
slabs, logs, or bark strips as well as smaller pieces such
as ends, shavings, or sawdust.
                              408
-------
          Liquified.petroleum gas consists mainly of butane,
propane, or a mixture of the two, and trace amounts of propylene
and butylene.  It is sold as a liquid in metal cylinders under
pressure and also from tank truck and tank cars.  The heating
value ranges from 26.3 kJ/m3 (97,400 Btu/gal) to 24.5 kJ/in3
(90,500 Btu/gal).

4,13.1.1  EmissionCharacteristics

          Volatile organic emissions from stationary external
combustion-sources are - dependent on.type and size of equipment,
method of--firing, maintenance practices, and on the grade- and
composition" of the fuel.  Considerable variation in organic
emissions ..can occur, .-depending on the efficiency of operation
of the individual unit..  Incomplete,combustion leads to .more -
emissions.  Estimates of .the emission rates of. organics •fr'om-'
externally fired units in 1975 are presented in Table 4.13-1.
Emission factors are given in Table 4.13-2.  All ambient  air
contains some organics from natural, and manmade sources.   There-
fore, net organics from fuel combustion should be  derived by
subtracting "tKe organi'cs that 'were present in the  combustion air
at the burner from the total emissions.
       TABLE 4.13-1.  ORGANIC EMISSIONS  FROM STATIONARY
                      EXTERNAL  COMBUSTION SOURCES3'"' 5
Source
Industrial
Commercial
Residential
Utility
1975 Emissions
Coal
55.4
8
11
105
.9
.7
.0
(61) *\
*
(10) J
(13)
(117)
Fuel
> 56

24
20
.4

.3
.8
Oil
(63)

(27)
(23)
Cg/yr (103T/yr)
Natural
76
I
12
1
.4a
.8
.4
.7
Gas
(85)
(2)
U*)
(1.9)
Wood
0,28a (3)

0.043 (0.043)

a5or  the year 1972.
                               409
-------
TABLE 4.13-2.   EMISSION FACTORS  FOR  STATIONARY EXTERNAL COMBUSTION SOURCES*
                                                                                          , 6-2 2

EPA Accuracy Rating0
Unit Type
Utility & Large
Industrial
Large Commercial
& General
Industrial
Commercial &
Domestic
Hand-fired
Coal, g/kg (Ib/ton)
Bituminous Anthracite
A B
0.15 (0.3)
0.5 (1) 'VO.I (0.2)
1.5 (3)
10 (20) 1.25 (2.5)
Fuel Oil Natural Gas Wood
Lignite kg/in" (lb/103 gal) kg/hm3 (Ib/lO5 ft3) g/kg (Ib/tonj
B A A B
0.5 (1) 0.12 (1) 16 (1)
0.12 (1) 48 (3) 1-35 (2-70)b
0.12 (1) 128 (B)

a expressed as methane

  use lower numbers for well designed and operated units

  a rating  of A indicates  "excellent" accuracy;  a rating of B indicates  "good" accuracy developed from
  limited data
-------
4.13.1.2  Control Techniques

          Volatile organic emissions from stationary external
combustion sources can be most effectively reduced by improved
operating practice and equipment designs which improve combus-
tion efficiency.  Organic emissions are directly related to
residence time, temperature, and turbulence in the combustion
zone.  A high degree of fuel and air turbulence greatly in-
creases combustion efficiency.  The trend toward better steam
utilization in steam-electric generating plants results in
improved efficiency in the conversion of thermal energy from
fossil fuels.into electrical energy.  Continued research in the
areas of magnetohydrodynamics, electrogas dynamics, fuel cells.,,
and solar energy may result in improved fuel usage and conse-
quently reduced organic emissions.

          Guidelines for good combustion practice are published
by the fuel industry, equipment manufacturers, engineering
associations, and government agencies.  Stationary combustion
units should be operated within their design limits, according
to the recommendations of the manufacturer, and in good repair
at all times.  Sources of information on good operating practice
include:

          1.  American Boiler Manufacturers Association
          2.  American Gas Association
          3.  American Petroleum Institute
          4.  American Society of Heating, Refrigerating,
              and Air-Conditioning Engineers
          5.  American Society of Mechanical Engineers
          6.  The Institute of Boiler and Radiator
              Manufacturers
                               411
-------
          7.  Mechanical Contractors Association of America
          8.  National Academy of Sciences - National
              Research Council
          9.  National Coal Association
         10.  National Fire Protection Association
         11.  National Oil Fuel Institute
         12.  National Warm Air Heating and Air-Condi-
              tioning Association
         13.  U.S. Bureau of Mines

          There is no information available on the reduction in
organic emissions resulting from the use of these controls..  The
percent reduction is probably.small for the small commercial and
residential units.  Small units have less efficient air-.fuel
mixing than large units and operate at somewhat lower tempera-
tures; therefore, they have lower average combustion efficiencies.
The potential for reduction of the emissions from wood-fired
furnaces may be moderate since most are. not regularly maintained.

          Flue gas monitoring systems such as oxygen and smoke
recorders are helpful in indicating the efficiency of furnace
operation.  The substitution of gas or oil for coal in any
type of furnace reduces emissions when good combustion techni-
ques are used.  This reduction is largely effected by the
better mixing and firing characteristics of a liquid or gaseous
fuel compared to those of a solid.

4.13.1.3  Cost,  Energy, and Environmental Impact of Controls

          Improved combustion efficiency produces cost and energy
credits by reducing fuel consumption.  Justification of the capi-
tal costs to replace or modify a combustion unit is site specific,
                               412
-------
          CO emissions are reduced by improved combustion effi-
ciency, while NOX emissions are increased.

4.13.2    Stationary Internal Combustion Sources

          Internal combustion engines include gas  turbines  or
large heavy-duty, general utility reciprocating engines.  Most
stationary internal combustion engines are used to generate
electric power,  to pump gas or other liquids, or to  compress
air  for pneumatic machinery.

          Stationary gas turbines are used primarily in elec- ,-„'."«•.
• t-r-ical generation for continuous, peaking or stand-by power.
The  primary fuels are natural gas and No, 2  (distillate)- 'fuel
oil, although residual oil is sometimes used.23  Emissions  from
gas.  turbines are considerably .lower  than emissions from recipro-
cating engines;  however, reciprocating engines are generally
moife efficient.  The rated power of reciprocating  engines ranges
from less than  15 kW to 10,044 kW (20 to 13,500 hp).2"  There
are  substantial  variations in both annual usage and  engine  duty
cycles.

4.13.2,1  Emission Characteristics             '               .-••••

         _The organic emissions  from stationary internal com-
bustion sources  .result from incomplete combustion  .of the fuel.,
                       i
The  emissions contain unburned fuel  components as  well as
organics formed from the partial combustion  and  thermal cracking
of the fuel.  Combustion and cracking products include aldehydes
and  low molecular weight saturated and unsaturated hydrocar-
bons.  Emissions from compression engines, particularly recip-
rocating engines, are significantly  greater  than those from
external combustion boilers.  Table  4.13-3 presents  estimates
of the annual  organic emissions  from fuel  oil  and  gas-fired
stationary  internal combustion  sources.
                               413
-------
       TABLE 4.13-3.  ORGANIC EMISSIONS FROM STATIONARY
                      INTERNAL COMBUSTION SOURCES25
Source
Industrial - Gas
Utility - Oil
Utility - Gas

(Gg/yr)
237.0
68.2
11.8
Emissions
(103 Tons/yr)
261.2
75.2
13.0
          Emission factors have been calculated on both a time
basis and a fuel basis for 116 electric utility single turbine
units operating in 1971.26  For both gas-fired and oil-fired
units, organic emissions were 0.36 kg/MWh (0.7 Ibs/MWh).   On a
fuel basis, gas-fired units emitted 637 kg hydrocarbon per hm3
gas (39.8 lbs/106 ft3) and oil-fired units emitted 0.668 kg
hydrocarbon per cubic meter of oil (0.0417 lbs/ft3).

          Emission factors for heavy-duty natural gas-fired
pipeline compressor engines, and gasoline and diesel-powered
industrial equipment are presented in Table 4.13-4.  The engines
used to determine the results in this table cover a wide range
of uses and power.  The listed values are not representative
of emissions from large stationary diesel engines.  Emission fac-
tors for natural gas-fired pipeline compressor engines, based on
the amount of fuel burned, are reported in Section 4.6,1,  Pipelines

4.13.2.2  Control Technology

          Emissions from internal combustion sources can be
minimized by proper operating practices and good maintenance.
Emissions could be reduced greatly with the application of
catalytic converters, thermal reactors or exhaust manifold air
injections to the engine exhaust.

                               414
-------
            TABLE  4,13-4,   EMISSION FACTORS FOR HEAVY-DUTY
                               INDUSTRIAL  ENGINES 2 7"3 °
                                     Category
                         Natural Gas-fired Compressor      Industrial Equipment
       Pollutant         Reciprocating     Gas Turbine       Gasoline     Diesel

Emission Factor Accuracy   Excellent       Excellent           Fair         Fsir

Hydrocarbons  as Ca
Ug/J 1.64 0.03
(lb/101 hphr) 9.7 0,2
kg/N ho*b 21,800 280
(lb/10* scf)b 1,400 23
Carbon Monoxide
. S/hr
(lb/hr)
3S/J
(.g/aphr) ••-• • -
kg/mj
(lb/101 gal)
Exhauat Hydrocarbons
g/br •
(lb/hr)
w/j'
-------
          These systems have not been tested on large bore units;
it is assumed that such applications would require careful de-
sign to assure a homogeneous high temperature environment through-
out the unit.

          The catalytic converter has been proven effective on
mobile gasoline engines.  It contains a catalyst which causes
the oxidation of HC and CO to water and C02 at reduced tempera-
tures.  Unleaded low-sulfur fuel should be used to protect the
catalyst and prevent the formation of H2SOn.

          A thermal reactor provides a site for oxidation at
elevated temperatures maintained by the heat released from the
oxidation of CO and HC.  Air is added to the exhaust stream in
a container specially designed to maximize both the residence
time and turbulence of the charge.

          Air injection into the exhaust system is similar to
the thermal reactor.  However, since the existing shape of the
exhaust system is not changed and the volume is not optimized
for maximum residence time, heat retention or mixing, air in-
jection is not as effective as the thermal reactor.31

A.13.2.3  Cost, Energy, and Environmental Impact of Controls

          Volatile organic emission controls for small and medium-
bore engines are similar to devices used on mobile sources.  A
retrofit catalytic converter for an automobile, including an
air pump, cost between  $105 and $260 in 1974.32  The cost of
modified devices for stationary engines may be considerably higher.33
The need to use unleaded, low-sulfur fuel increases operating costs
for engines fitted with catalytic converters.
                               416
-------
          Energy is required to operate air pumps for thermal
reactors, air injection systems, and catalytic converters that
use extra air for combustion.  Energy credits are provided for
installations that use waste heat boilers for secondary heat re-
covery .

          Catalytic converters produce SOx emissions from any
sulfur in fuel.  By combusting at lower temperatures than thermal
incinerators and air injection systems, however, they have a
lower tendency to produce NOX emissions.  The solid waste impact
from disposal of spent catalyst is minimal.

          Volatile organic emissions from uncontrolled large-bore
engines are generally low:  in the range achievable by control of
medium-bore engines on mobile sources.  Control of large-bore en-
gines is only necessary when volatile organic emissions are in-
creased as the result of control techniques for other emissions,
such as NOX.  Therefore, there are no direct costs or energy re-
quirements for control of-volatile organic emissions from large- '
bore engines.3'*

4.13.3    References

1.  U.S. Dept. of Commerce, Social & Economic Statistics Admin.
    Statistical Abstract of the U.S.  1974, 95th Annual Edition.
    Washington, B.C., 1974.  As cited in Cavanaugh, E. C., et al.
    Hydrocarbon Pollutants from Stationary Sources.  Radian
    Corporation, 1977.

2.  U.S. Bureau of Mines, Division of Duels Data.  Crude Petro-
    leum, Petroleum Products, and Natural Gas Liquids; 1974.
    Petroleum Statement, annual.  Washington, D.C. April 1976.
                                417
-------
3.   Environmental Protection Agency, National Air Data Branch.
    1972 National Emissions Report.  National Emissions Data
    System (NEDS) of the Aerometric and Emissions Reporting
    Systems (AEROS).   Research Triangle Park, N.C.  EPA 450/2-
    74-012.  1974.  As cited in Cavanaugh.   1977.

4.   Monsanto Research Corp., Dayton Lab.  Overview Matrix for
    Air Pollution Sources.  Special Project Report.  EPA Contract
    No. 68-02-1874.  Dayton, Oh.  July 1975.  As cited in
    Cavanaugh, 1977.
         I

5.   Putnam, A. A., E. L. Kropp, and R. E. Barrett.  Evaluation
    of National Boiler Inventory, Final Report.  Battelle
    Columbus Labs.  Columbus, Ohio.  Contract No. 68-02-1223,
    Task 31.   Oct. 1975.  As cited in Cavanaugh, 1977.

6.   Smith.  W. S.  Atmospheric Emissions from Coal Combustion
    U.S. DREW, PHS, National Center for Air Pollution Control.
    Cincinnati, Ohio.  PHS Publication Number AP-51.  January
    1969.  As cited in Environmental Protection Agency, Compila-
    tion of Air Pollutant Emission Factors, 2nd Ed. with Supple-
    ments.   Publication AP-42.  1973.

7.   Perry, H. and J. H. Field.  Air Pollution and  the Coal
    Industry.  Transactions of  the Society  of Mining Engi-
    neers.   238:337-345, December 1967.  As cited in EPA, AP-42,
    1973.

8.   Heller, A. W. and D. F. Walters.  Impact of  Changing
    Patterns of Energy Use on Community Air Quality.  J.
    Air Pol. Control Assoc.  15:426,  September  1965.
    As cited in EPA, AP-42, 1973.
                               418
-------
 9.   Cuffe,  S.  T.  and R.  W.  Gerstle.   Emissions from Coal-
     Fired Power Plants:   A Comprehensive Summary,  U.S.
     DREW, PHS,  National  Air Pollution Control Administration.
     Raleigh,  N.C.   PHS Publication Number 999-AP-35.   1967.
     p.  5.  As cited in EPA, AP-42, 1973.

10.   Austin, H.C.   Atmospheric Pollution Problems of the Pub-
     lic Utility Industry.  J. Air Pol. Control Assoc.
     10(4):292-294, August 1960.   As cited in EPA, AP-42, 1973

11.   Hangebrauck,  R.  P.,  D.  S, Von Lehmden, and J. E.  Meeker.
     Emissions of Polynuclear Hydrocarbons and Other Pollu-
     tants from Heat Generation and Incineration Processes.
     J.  Air Pol. Control  Assoc.  14:267-278, July 1964,
     As cited in EPA, AP-42, 1973.

12.   Hovey, H. H., A. Risman, and J. F, Cunnan.  The Develop-
     ment of Air Contaminant Emission Tables for Nonprocess
     Emissions.  J. Air Pol. Control Assoc.  16:362-366,
     July 1966.  As cited in EPA, AP-42,  1973.

13.   Anderson, D. M., J.  Lieben,' and V. H. Sussman.  Pure Air
     for  Pennsylvania.  Pennsylvania Department of Health.
   '^•Harrisburg, Pa.  November 1961.  P,. 91-95.  As cited in
     EPA, AP-42,. 1973.

14.  Communication with National Coal Association.  Washing-
     ton  D.C.  September  1969. As  cited  in EPA, AP-42,  1973.

15.   Levy, A. et al.  A Field Investigation of Emissions from
     Fuel Oil Combustion for Space Heating.  Battelle Colum-
     bus Laboratories.  Columbus, Ohio.  API Publication 4099.
     November 1971.   As cited  in EPA,  AP-42,  1973.
                                419
-------
16.   Barrett, R. E. et al.  Field Investigation of Emissions
     from Combustion Equipment for Space Heating.   Battelle
     Columbus Laboratories.  Columbus, Ohio.  Prepared for
     Environmental Protection Agency, Research Triangle Park,
     N.C., under Contract No. 68-02-0251.  Publication No.
     R2-73-084a.  June 1973.  As cited in EPA, AP-42, 1973.

17.   Cato, G. A. et al.   Field Testing:  Application of Com-
     bustion Modifications to Control Pollutant Emissions
     From Industrial Boilers - Phase I.  KVB Engineering, Inc.
     Tustin, Calif.  Prepared for Environmental Protection
     Agency, Research Triangle Park, N.C., under Contract
     No. 68-02-1074.  Publication No. EPA-650/l-74-078a.
     October 1974.  As cited in EPA, AP-42, 1973.

13.   Deffner, J. F. et al.  Evaluation of Gulf Econoject Equip-
     ment with Respect to Air Conservation.  Gulf Research and
     Development Company.  Pittsburg, Pa.  Report No. 731RC044.
     December 18, 1972.   As cited in EPA, AP-42, 1973.

19.   Dietzmann, J. E.  A Study of Power Plant Boiler Emissions,
     Southwest Research Institute.  San Antonio, Texas.  Final
     Report No. AP-837.   August 1972.  As cited in EPA, AP-42,
     1973.

20.   Danielson, J. A. (ed.).  Air Pollution Engineering Man-
     ual.  U.S. Department of Health, Education, and Wel-
     fare, PHS, National Center for Air Pollution Control.
     Cincinnati, Ohio.  Publication No. 999-AP-40.  1967.
     p.   As cited in EPA, AP-42, 1973.
                                420
-------
21.  Droege, tt'. and G. Lee... The Use of Gas Sampling and
     Analysis for the Evaluation of Teepee Burners.  Bureau
     of Air Sanitation, California Department of Public
     Health.  (Presented at the 7th Conference on Methods
     in Air Pollution Studies, Los Angeles.  January 1967.)
     As cited in EPA, AP-42, 1973.

22.  Junge, D. C. and R. Kwan,  An Investigation., of the   ,... •'
     Chemically Reactive Constituents-of Atmospheric Emis-
     sions from Hog-Fuel Boilers in Oregon.  PNWIS-APCA
     Paper No. 73-AP-21.  November 1973.  As cited in EPA,
     AP-42, 1973.

23.  O'Keefe, W, and R. G, Schwieger.  Prime Movers.  Power.
     115 (ll):-522-531.  November 1971.  As cited in Cavanaugh
     1977.  ••  -•                                           •"-•"'

24, _  Diesel and Gas Turbine Program.  Diesel and Gas Turbine
     Worldwide Catalog, 1974 edition,  Milwaukee, Wisconsin.
     As cited in Standard Support Document and Environmental
     Impact Statement:  Stationary .Reciprocating Internal
'   '." Combustion Engines.'  Airotherm Project 7152, prepared
 --..for EPA.--March 1976.  As cited .in- EPA, AP-42., .1-973',

25.  Aerospace Corp.  Pr-ivate--Communication.  Los Angeles.
     February. 1976.  As cited in EPA, AP-42, 1973.

26.  Heller, 196,5.  As cited in EPA, AP-42, 1973.

27.  Sawyer, V. ₯. and R. C. Farmer.  Gas Turbines in U.S.
     Electric Utilities.  Gas Turbine International.  January-
     April 1973.  As cited in EPA, AP-42, 1973.
                                421
-------
28.   Hare, C.  T.  and K.  J.  Springer.   Exhaust Emissions from
     Uncontrolled Vehicles  and Related Equipment Using Internal
     Combustion Engines.   Final Report.   Part 5:  Heavy-Duty
     Farm, Construction,  and Industrial Engines.  Southwest
     Research Institute.   San Antonio, Texas.  Prepared for
     Environmental Protection Agency,  Research Triangle Park,
     N.C., under Contract No. EHS 70-108.  October 1973.  105 p.
     As cited in EPA, AP-42, 1973.

29.   Hare, C.  T.  and K.  J.  Springer.   Exhaust Emissions from
     Uncontrolled Vehicles  and Related Equipment Using Internal
     Combustion Engines.   Final Report.   Part 6:  Gas Turbine
     Electric Utility Power Plants.  Southwest Research Insti-
     tute.  San Antonio,  Tex.  Prepared for Environmental Pro-
     tection Agency, Research Triangle Park, NC, under Contract
     No. EHS-70-108.  February 1974.   As cited in EPA, AP-42,  1973,

30.   Urban, C. M. and K.  J. Springer.   Study of Exhaust Emis-
     sions from Natural Gas Pipeline Compressor Engines.
     Southwest Research Institute.  San Antonio, Texas.  Pre-
     pared for American Gas Association.  Arlington, Va.
     February 1975.  As cited in EPA,  AP-42, 1973.

31.   Aerotherm.  Standard Support Document and Environmental
     Impact Statement:  Stationary Reciprocating Internal Com-
     bustion Engines.  Prepared for EPA, RTF, NC.  March 1976.

32.   Gibney, Lena.  Catalytic Converters:  An Answer from
     Technology.   Environmental Science and Technology 8(9)
     September 1974. pp.  793-799.
                               422
-------
33.   Roessler,  W.  V.,  A.  Muraszew,  and R.  D.  Kopa.   Assessment
     of the Applicability of Automotive Emission Control Tech-
     nology to  Stationary Engines.   Aerospace Corporation.   El
     Segundo,  California,  Prepared for Environmental Protection
     Agency, Research Triangle Park, N.C., under Grant No.
     R-802270.   Publication No. EPA-650/2-74-Q51.   July 1974.
     p. 5-22.

34.   Reference 31.
                              423
-------
4.14      Metallurgical Coke Plants

          The majority of coke manufacturing in the United States
is performed to supply the steel industry with blast furnace coke.
There are generally two methods of coke manufacturing practiced
today:  by-product coking and beehive coking.  Beehive coking does
not include recovery of volatilized organics.   This may result in
much higher organic emission rates.  By-product coking, however,
is used for almost 99 percent of U.S. coke production.

          In by-product coking coal is charged by gravity flow
from large, hopper carrying cars (larry cars)  on wide guage
rails into narrow, rectangular ovens.  The ovens are lined with
silica brick and are typically 45 cm (18 in) wide, 12 m (39 ft)
long, and 4.5 m (15 ft) high.1  The ovens are arranged side by
side in groups called batteries and are heated by burning gas
in flues between the walls of adjacent ovens.

          Instead of burning, the coal bakes at temperatures
ranging from 870°C to 1260°C (1600T to 2300°F)2 for 16 to 25
hours,  During baking, air is excluded from the ovens and the
intense heat releases volatiles contained in the coal.  These
vapors are transferred to a chemical plant for recovery of gas,
tar, and ammonia liquor.  About 45% of the coke-oven gas pro-
duced is used to heat the ovens-.  The remaining gas is used as
fuel in other steel mill operations.

          At the end of the coking period, a large ram is used
to push the coke out of the oven and into a railway car.  The car
is taken to a quench tower where the coke is drenched with water
to lower the temperature to a point below the ignition temperature,
Afterward, the quench car moves to a coke wharf where the coke  is
transferred by conveyor belt to the coke handling area.
                               424
-------
          In the beehive process the coal is deposited and leveled
on the floor of a refractory-lined enclosure with a dome-shaped
roof  (the beehive).  By regulating openings to the beehive oven,
the amount of air reaching the coal is controlled.  Carbonization
begins at the top of the coal pile and proceeds downward through
it.  All volatile matter escapes to the  atmosphere through a  open-
ing in the roof.  When coking is completed, the coke  is watered
out or quenched.3

4.14.1    Emission Characteristics

          Since beehive coking is not widely practiced and
emission characteristics are not well described, this section
is limited to emissions from by-product  coking.       ' •--.  -

          •Although coke itself is almost pure carbon, it. is-made ..
'from coal that, contains an average of 20 to 32 percent of other
elements.  The other elements are released as gases during the
coking process.  Volatile organic emissions can occur during  charg-
ing-» coking, and discharging.  Estimates of these emissions are
given in Table 4.14-1. •• Emissions can also .occur during quenching.
     TABLE 4.14-1.  TOPICAL EMISSION FACTORS FOR VOLATILE
                    ORGANICS FROM COKE-OVEN OPERATION4

                                 Emission Factor3

By-Product Coking:
Charging
Coking Cycle
Discharging
Beehive Ovens
g/kg coal

.1
0
0
4
charged

.25
.75
.1

Ib/ton coal

2.5
1.5
0.2
8
charged





a
 Factors rated average (c) according to explanation in introduc-
 tion to Reference 4.  The numbers  are rough estimates due co the
 lack of good  emissions data.   425
-------
4.14.1.. 1  Charging

          Although coke-oven charging is an intermittent source
of emissions, it is also one of the largest single contributors
of volatile organic emissions in the coking operation.  Since
charging begins shortly after discharging of the previous batch,
the oven interior is extremely hot and the coal begins to "bake"
upon entering.  When uncontrolled, steam, gas, and air blow out
of the open oven ports carrying organics, ammonia, sulfur dioxide,
and particulates.

4.14.1.2  Coking Cycle

          Since the coking cycle can take as long as 16 to 25
hours, emissions during this step in the coking process can be
considered continuous.  Most of these emissions are the result
of leaks in and around the coking oven.  Significant points of
oven leakage are charging lids, oven doors, standpipe lids,
cracks in the oven offtakes, flange connections, and cracks in
the refractory oven walls.

          Due to the extremely high temperatures, charge lids
and seats become distorted and difficult to seal.  A luting
material is used to create an effective seal.  Luting involves
pouring a wet mixture of clay and coke breeze into a channel
between the lid and seat.  Cleaning of the lids and seats  is
essential for a proper seal.

          Luting is also used at a few plants to  seal oven doors
at the joint between  the door and the jam.  Newer oven  door
designs feature a  self-sealing metal-to-metal contact.  The
design relies on a mechanical arrangement for exerting  pressure
between a machined surface and a knife edge.  A stringent  main-
tenance program must be followed  since leaks will eventually  occur.5
                              426
-------
          Another common leakage point in many plants is the
standpipe lid.  This is usually the result of poor lid posi-
tioning by an operator or heat distortion from months of use.
The problem can often be eliminated by careful positioning
after charging and by luting.  New lid designs are being inves-
tigated. 6

          Cracks in coke-oven walls result in increased emissions
For years it has been standard practice to depend to a certain
extent on the natural formation of carbon at relatively fast
coking rates to seal many cracks and open joints.  However,
with slower operating rates and lower temperatures, and in the
event of particularly large-cracks,_ the current practice is .to.
rely on regular oven patching crews.

          Other possible leakage points are door sills, stand-
pipe base seals, collecting mains, and gooseneck extension
elbows.  As with other coke-oven leaks, an adequate maintenance
program, including prompt replacement of faulty equipment,
will eliminate most emissions.

4.14.1.3  Discharging

          The intermittent volatile organic emissions from coke-
oven discharging (oven-pushing) are relatively small.  Although
the emissions depend on a number of factors, the heaviest or-
ganic emissions are almost always  caused by pushing "green"  coke.
Green coke results from incomplete carbonization of coal during
the coking cycle.

          Green coke is produced by both old and new ovens,  but
for different reasons.  Heating deficiencies in older ovens  re-
                               427
-------
suit from heavy oven-to-flue leakage,  excess quantities of coal
piled up against the end flue heating  surfaces,  poor combustion
control, and poor regenerator efficiency.   Related problems arise
from oven wall cracking and brickwork  movement at the oven ends.
In new ovens the problems are poor oven wall maintenance,  preven-
tion of good heating by overfilling,  overtaxing end flue heating
capabilities by accumulating excess coal volumes at the oven ends,
or poor coal blending.   Green coke may also be produced by push-
ing early.  Whatever the circumstances, an emission reduction can
often be achieved through major oven repairs, reduced coal volumes,
or slower coking rates.7

4.14.1.4  Quenching

          Volatile organic emissions from quenching are intermit-
tent or continuous, depending on the quenching technique.  Levels
of emissions depend on the purity of the quench water.  Volatile
organics in the water evaporate upon contacting the hot coke.
Emissions have been caused by using quenching towers for the dis-
posal of polluted by-product coke plant or metallurgical mill
wastewaters.  Some emissions may also  originate  from green coke.

4.14.2    Control Technology

          Each coke manufacturing operation has unique emission
problems depending on the size of the coke-oven battery, age of
the equipment, ability to retrofit and/or modify existing pro-
cesses, and many other details.  These differences, the attempts
of many vendors to get into the market, and the attempts of many
steel companies to solve their own problems account for the wide
variety of control techniques.
                               428
-------
4.14.2.1  Charging

          Due to the extremely high emissions of organics and
other compounds associated with the charging of coke-ovens,
many control methods have been proposed for this operation.
The possible alternatives include aspiration by steam jet or
liquor spray, larry-mounted wet scrubbers or disintegrators,
fixed-duct secondary collectors, staged or sequential charging,
and closed or sealed charging.

          Aspiration systems use a steam jet or liquor spray to..;::.
artificially Increase the net draft on a coke oven while it Is "
being charged.  The increase in net draft depends on the aspira-
tion, rate and nozzle size and placement.  The induced draft -
draws potential emissions up.a.standpipe and into a collector.
main.  Some systems have two collector mains located at opposite
ends of the oven to avoid loss of aspiration if coal happens to
blo-ck off part of the open space at the top of the oven during
charging.  Steam aspiration alone does not provide complete
emission control.8-    '  ...

          Wet scrubbers or disintegrators mounted on larry  cars
we're designed as an add-on device to control charge-hole emis-
sions that occur in spite of aspiration.  The larry cars are
specially equipped with shrouds or hoods that surround the
charge holes and drop sleeves.  Gases drawn up through these
shrouds are combusted and scrubbed, and then exhausted through
fans and stacks on the larry car.  Some difficulties encountered
with these devices include severe maintenance problems, dis-
posal of polluted wastewater, sensitivity  of  adjustment,
and ignition failure.9
                                429
-------
          Fixed-duct secondary collectors are not an independent
control method but are supplemental to aspiration systems and
larry-mounted wet scrubbers.  Instead of exhausting directly to
the atmosphere, the effluent from the scrubber is channeled to
a secondary scrubber system where particulates and smoke are
removed.  Although fixed-duct secondary collectors are in use,
the expense is high and the efficiency is limited by the solu-
bility of organics in the scrubbing liquor.

          Unlike the previously discussed control methods,
staged or sequential charging is a process change and not a
retrofit device.  The principle of staged charging is to assure
the adequacy of aspiration alone as a primary control.  Staged
charging involves charging to one or, at most,, two ports at a
time.  A normal coke oven has four charging ports, all of which
are used simultaneously.  In staged charging a definite sequence
is followed:  for example, first ports 1 and 4 are charged,
followed by 2, and then 3.  When a port is not being charged,
the lid is closed and the induced draft created by the aspirator
is more effective since the smallest possible opening to  the  atmos-
phere is maintained.

          Actual charge times are estimated at 2.75 minutes on
a 3.7 m (12 ft) battery and 3.5 minutes on a 4.3 m (14 ft)
battery.10  Some requirements for staged charging include indi-
vidually operated charging port lids and coal hoppers, two-way
drafting of the free space at the top of the oven, adequate
aspiration, and crew coordination.  Use of special equipment
is minimized.

          Closed or sealed charging involves radical changes  in
the present coke-oven charging process.  One system transports
preheated coal at 260°C (500°F) via pneumatic pipeline directly
                               430
-------
into the ovens.  Estimates are that coke production is increased
by 507., due to reduced coking time.11  Other proposed systems em-
ploy conveyors with fixed charging chutes to the coke ovens or
larry cars.   All  these  systems were designed primarily  to in-
crease coke production per unit volume of coke oven.  The methods
allow the use of lower quality coals without reduction in coke
quality.12  The fact that both charging methods provide an effec-
tive means of emission control is an additional advantage.  Capa-
bility to retrofit depends on the ability to make oven work changes
and the availability of space for preheater and pipeline equip-
ment.

4.14.2.2  Coking Cycle                                    '  .'.'

          Emissions during the--coking cycle are--predominantly ...
the result of leaks caused by cracks in the coke-oven walls -mad-
improper seals at lids, doors, and standpipes.   Several methods
have been considered 'for eliminating leaks from coke-oven cracks.
Several companies have achieved some success with a pressurised
dusting process in which fine refractory material (silica) is
fed' into empty "ovens to -fill • small cracks.  Larger cracks are
filled by remote control gunning of patching compound.  Still
other plants  have attempted to-, reduce emissions by reducing
oven back pressures.  There is some danger, however,  that  the
infiltrated air may cause the burning of gas at oven  openings'.  .
Good'control  appears to require a conscientious maintenance
program with  good operating practices.

          Emissions resulting from  improper  seals can be-coii-,--
siderable.  One report  states that  for  a battery of eighty  6.4  m
(21  ft) coke  ovens, operating on a  16-hour coking cycle,  the
length of end door seals broken and remade every 24 hours  amounts
to almost  3,7 km  (2.3 mi).13  These  seals must be closely fitted
                               431
-------
under extremely hot, dirty, corrosive conditions.   Luting is
rarely practiced on large, fast ovens, and most plants rely on
self-sealing doors.  The seals may either be mounted on a flex-
ible plate (diaphragm-type seals) or on the door frame (strip-
type seals).   Emissions from door leaks may be collected in
hoods.  Good control of emissions requires proper maintenance
of seals to prevent buildup of carbon and tar deposits.

4.14.2.3  Discharging

          Even though the worst discharge emissions result from
pushing green coke, no technique has been developed to anticipate
green coke formation.  Therefore, to ensure proper emission
control, the plant must be prepared for the possibility of green
coking at any time.  The most common approach has been the con-
tainment of emissions by some type of hood or covering device.

          There are many variations on this method. For instance,
one plant uses a partially open entrapment structure which com-
pletely covers the discharge area including the quench car.  A
150 kW (200 hp) motor is used for continuous evacuation at a
rate of approximately 66 m3/sec  (140,000 ft3/min).'"  Another
plant employs a mobile hood which covers the coke  guide and
quenching car.  Contaminated gases are conducted to scrubbers
on the same platform.  There are numerous other hooding systems
and the choice of  system depends partially on the  retrofit capa-
bilities for the plant under consideration.

          Another recent development is related to rapid or con-
tinuous quenching of the discharged coal.  The design calls for
a completely enclosed hot car which accepts the discharged hot
coke for transfer  to either a mobile rotary kiln or a series of
conveyor belts for quench.  Gases from the enclosed hot car are
                               432
-------
easily collected and scrubbed.  Prototype enclosed hot cars have
performed very well.

4.14.2.4  Quenching

          Emissions from quenching can be reduced by using clean
water.  Many control agencies already require that quenching water
be purified to a quality that can be disposed in rivers and streams

          Dry quenching is an alternate quenching technique that
controls volatile organic emissions by eliminating the use of
water.  Cdke is cooled in. a closed system by" a circulating..,stream
of in^rt: gas.  Sensible heat picked up from the coke is trans-
ferred to a waste heat boiler-for the .production of steami  Dry-
quenching produces a better quality of coke than wet quenching,'
Lower grades of coal, therefore,. can• be used -to charge the'coke
ovens.  The steady cooling of dry quenching also increases the
usable coke output by  2-37, .by decreasing,.the production of fine
coke particles.

          Dry quenching facilities, however, have some inherent
problems.  They require more ground area than comparable wet
quenching facilities.  Retrofit, therefore, may be difficult or
impossible.  They also require continuous monitoring and careful
maintenance to prevent explosions caused by oxygen leaking into
the closed system.  Although successfully employed in several-'
foreign countries, dry quenching is not currently used in  the
United States . * s

4.14.2.5  New Technology                                   .. ..

          The advent of pelletized or formed coke could mean
the end of coke-oven emissions by eliminating the need for coke
                               433
-------
ovens.  A fluidized bed is used to accomplish the conversion of
coal to coke while simultaneously removing the volatiles.   In
some cases pitch recovered from the gas stream is used as  the
binding material for the coke pellets.  This process is completely
enclosed and produces minimal emissions.  Although formed  coking
is in the demonstration stages, commercial production is not
likely for another seven to nine years.16

4.14.. 3    Cost, Energy, and Environmental Impact of Controls

          Most control techniques for coke ovens are still under-
going testing and development.  Ease of retrofit for each control
is also site specific.  As a result, costs, when available are
estimates at best and may vary considerably for actual installa-
tions .

          Most techniques have been developed to control particu-
late emissions.  Capability to control volatile organic emissions
is secondary.  If any of these methods are already employed for
particulate emission control, there will be no additional cost,
energy, or environmental impact associated with volatile organic
emission control.

4.14.3.1  Charging

          Most coke ovens are already equipped with steam aspira-
tion systems for particulate control.17  Therefore, there will be
no additional impact from this control technique.

          Estimates of capital and  annual  costs  for larry mounted
scrubbers, staged charged, and pipeline  charging are presented in
Table 4.14-2.  Data is provided for retrofit  installations  to  a
typical plant producing 1.13 Tg/yr  (1.24xl06  tons/yr).
                               434
-------
            TABLE 4.14-2.  ESTIMATES OF CAPITAL AND ANNUAL  COSTS FOR RETROFIT  INSTALLATIONS
                            OF  VARIOUS CHARGING EMISSION CONTROLS IN  A TYPICAL  (1.13 Tg/yr
                            (1.24xl06 ton/yr) COKE  PLANT3.18
Ul
Control Technique Variation Larry Car
• '. \
Larry mounted scrubbers N.A. New
'• . Modified
Staged Charging Single Collecting Main New
(AISI/EPA)
Dual Collecting 'Main New ;
: Modified
Jumper Pipe • ,- New
Modified
Pipeline Charging N.A'. . N.A. ?
Capitalb

$2,730,000
1,980,000
3,800,000
5,650,000
5,350,000
2,690,000
2,890,000
29,350,000
Annual

$411,150
324,750
431,000
781,000
745,000
297,400
403,650
4,014,700
^Early 1973 costs.
      Capital costs are installed equipment costs including environmental units for  larry car operators to
      ^satisfy OSHA requirements.
      "Annual costs include annualized capital costs, operating, maintenance, and repairing costs, taxes,
      fand insurance.
      N.A. Indicates not applicable.
-------
          Larry mounted scrubbers require energy to pump scrubbing
liquor and consume fuel or electricity to support combustion.
They also increase the plant's water use.  Scrubbers involve an
environmental impact due to production of a polluted wastewater
stream that must be treated before disposal.  Costs for wastewater
treatment are included in the annual cost estimates in Table
4.14-2.  Combustion of volatile organic emissions from coke pro-
duction produces SOX and has the potential to produce NOX, CO,  and
particulates.  Unless removed by upstream control devices,  these
pollutants will be emitted to the atmosphere.  General discussions
of scrubbers and incinerators are provided in Sections 3.1 and 3.3.

          Effective staged charging requires an aspiration system
capable of producing a strong draft.  This can be accomplished by
modifying the existing aspirating system to operate at higher
steam pressures.  The increased pressure requires no extra costs
or energy, since steam is normally provided to a coke plant at an
elevated pressure and is then reduced to a designated pressure be-
fore aspirating.19  The corresponding increase in the volume of
steam required, however, increases costs and energy requirements
for the production of steam.  It also increases the amount of
water used and the resultant volume of polluted wastewater.  Costs
for extra steam are included in Table '4.14-2.

     Costs to retrofit pipeline charging are too high to justify
installation for emission control alone.  Cost and energy credits
provided by  increased productivity and the ability to use lower
grades of coal, however, may offset these costs.  A new pipeline
charging installation costs about 1070 less than a new conventional
uncontrolled oven of the same capacity.20

          Fixed duct secondary collectors have been used in Japan,
but are considered to have very little potential effectiveness
relative to  their cost.21  Since they are wet scrubbers, they re-

                               436
-------
quire energy for pumps and increase the plant's water require-
ments.  Production of polluted wastewater from the scrubbers re-
quires treatment facilities.  Additional information on scrubbers
can be found in Section 3.3.

4.14.3.2  Coking Cycle

          Maintenance costs to control leaks are the costs of la-
bor and materials.  Costs and energy requirements depend on the
age and condition of the. ovens and the type of patching method
chosen.                                                      ,,-•-•-••

          Automatic methods for cleaning the mating surf aces.'of_.
self-sealing do-ors include mechanical scrapers and water-jets.
Cost 'and energy information is unavailable in the consulted lit-'
erature.

4.14.3.3  Discharging

          Some form of hood can be adapted to almost any existing
plant.  Capital costs are high for sites with inadequate clearance
or inadequate support in..existing structures-.2;2  Totally enclosed
sheds are generally less expensive to construct than partially
open  hoods but a poorly .designed shed creates a dirty  and  poten-
tially dangerous work place.  Enclosed hot  cars are  a  more expen-
sive  option..--23 --

          Energy requirements for hoods  and  sheds might be quite
high.  Since partially open hoods are open  to the atmosphere,
fans  in the range of 373-1,492 kW  (500-2000  hp) may  be necessary
to create an adequate draft for efficient emission control.   En-
closed sheds require more  energy for  fans .   They have  tic re air  to
move  in order  to provide adequate ventilation,  to eliminate the
buildup of explosive or poisonous gases,  and to  dissipate  heat.
The secondary  pollution from  the production  of  the enormous amounts

                               437
-------
of power required to drive these fans could conceivably exceed
benefits from the control device.2"

          All associated scrubbers require energy for pumps and
increase the plant's water requirements.  A polluted wastewater
stream results from their use.  General information on scrubbers
is provided in Section 3.3.

4.14.3.4  Quenching

          Costs and energy required to produce clean water are
no higher than what would normally be required to treat waste-
water for disposal.

          Estimates of capital and annual costs for three types
of Soviet dry-quenching facilities are presented in Table 4.14-3.
The facilities are designed to process 2 Tg of coke per year
(2xl06 tons/yr).   Cost credits are provided by the ability to
use lower grades of coal, increased usable output, and the re-
covery of waste heat in the form of steam.  For each facility,
the credits exceed operating costs and are high enough to pay
for the facility within four years.

          Energy recovery is a distinct advantage of dry quenching
over wet quenching.  Of the 3.22 kJ/g  (2.78xl06 Btu/ton) used  to
coke coal, 52% (1.67 kJ/g or  1.44xl06  Btu/ton) is retained as
sensible heat.  All of this energy is  lost by wet quenching.   Dry-
quenching towers recover 1.37 kJ/g (l.lSxlO6 Btu/ton) or 82% of
the heat lost by wet quenching.  Recovered heat can be used to
produce steam or electricity, or it  can be used to preheat coal
for a closed charging operation.26

          Dry quenching eliminates the plume of steam and par-
ticulates associated with wet quenching.  However, coke produced
by dry quenching is dustier.  Extra  particulate control measures
may be necessary for handling dry-quenched coke.
                              438
-------
           TABLE 4.14-3.  ESTIMATES OF CAPITAL AND ANNUAL COSTS  FOR SOVIET DRY-QUENCHING

                           FACILITIES  CAPABLE- OF PROCESSING 2 Tg  OF COKE  PER YEAR (2,000,000

                           TONS/YR)25
-o
CO
Type Number of Towers Capital Costs
106$
A 5 10.2 to 11.32
B 4 8.8 to 9.8
C 2 :7.1 to 7.8
Annual Costs
106$
-4.051C
-3.394°
-3.327C
Pay-Out period
After Taxes
3.9 yr
3.9 yr
3.4 yr
   , Capital costs Include materials and manpower.                                :

    Annual costs include costs for electricity, labor, and maintenance and  credits from ability to use

    lower grade coke, increased usable productivity, and recovery of  heat for steam production.   Annualized

    capital coats are not  included.
   c
    Negative sign indicates that credits exceed operating  costs.
-------
    4.14.4     References

    1.   Radian Corp.   Hydrocarbon Pollutants  from  Stationary  Sources.
        Draft Report.   Austin,  Texas.   Contract  No,  200-045-48.
        August 1976.

    2.   Controlling Emissions  from Coke Ovens.   Environmental
        Science and Technology.   Vol  6  (2), February 1972.

  3-5.   Environmental  Protection Agency.   Compilation of  Air
        Pollution Emission Factors.   2nd Edition with supplements.
        AP-42.  1973.

  6-7.   Edgar, William D.   Coke-Oven  Air Emissions Abatement.
        Iron and Steel Engineer.  October 1972.

  8-9.   Barnes, Thomas M. , et  al.  Control of Coke-Oven Emissions.,
        Battelle-Columbus  Laboratories.  December  31, 1973.

   10.   Munson, J. G., et  al.   Emission Control  in Coking Operations
        by  Use of Stage Charging.  Journal of the  Air Pollution
        Control Association.   24 (11),  November  1974.

   11.   Reference 2.

12-13.   Reference 8.

   14.   Roe, Edward H. and James D. Patton.  Coke-Oven Pushing
        Emission Control System.  Journal of the Air Pollution
        Control Association.   25(4),  April 1975.
                                   440
-------
   15.   Linsky, Benjamin, et al.  Dry Coke Quenching, Air Pollution
        and Energy:  A Status Report.  Journal of the Air Pollution
        Control Association.  2_5 (9) ,  September 1975.

   16.   Reference 8.

17-20.   Kertcher, Larry F. and Benjamin Linsky.  Economics of Coke
        Oven Charging Controls.  Journal of the Air Pollution Con-
        trol Association.  2_4(8) ,  August 1974.

 " 21.   Reference 8.

   22.   Reference 6.                ~                         .;;   •'

23-24.   Reference 8.

25-26.   Reference 15.
                                    44:
-------
4.15      Waste Handling and Treatment

          The disposal of gaseous, liquid, and solid wastes
generated by industrial, commercial,  agricultural,  municipal,
and residential activities employs a diverse and complicated
scheme of handling and treatment systems.   Emissions resulting
from waste disposal are often unique to a particular industry
or process.   This section includes separate discussions of waste
treatment for the petroleum refining and organic chemical indus-
tries (Section 4.15.1), and solid waste, incineration (Section
4.15.2).  For a discussion of waste solvent disposal see Section
4.19, Degreasing.

4.15.1    Petroleum Refinery and Organic Chemical Waste Disposal

          The petroleum refining and organic chemical manufac-
turing industries are highly complex operations which process
many feedstocks into a multitude of final products.  Consequently,
the wastes from these industries come from many different sources
and many different control methods are required.  The wastes are
gaseous, liquid, or solid.

          Gaseous Waste

          In the past, waste gases were either vented to the
atmosphere or mixed with large amounts of liquid wastes and
burned in open pits.  These methods of disposal are no longer
environmentally acceptable or economically practical.  For the
most part, the industry now relies on direct flaring and on
blowdown systems followed by product recovery, combustion and
heat recovery, or flaring (see Section 4.1, Emission Sources
Common to the Petroleum and Chemical Process Industries).
                              442
-------
          Liquid Waste

          The term "liquid waste" almost always signifies water
which has become contaminated by oil, chemicals, metals, or sus-
pended solids.  A wastewater system handles water from a number
of sources including cooling water, process water and steam con-
densates, storm runoff, blowdown water,' sanitary wastes, and
ship ballast waters.  Wastewater treatment is usually accomplished
in three stages (primary, secondary, and tertiary) by a series of
physical, chemical, and/or biological treatment techniques.  These
various treatment methods are shown in Table 4.15-1.

          Solid Waste

          The most common methods of solid waste disposal are
land disposal and incineration.  Due to the low cost and con-
venience, land disposal has been the predominant means of handling
solid waste.  Incineration, on the other hand, can be used for
wastes which  are  too heavily contaminated with toxic substances
for  land disposal.  In most instances incineration  is not  a
complete waste disposal method in  itself since there is an as"h
or residue which  remains after combustion.  After incineration,
however, the-volume of solid waste  is. reduced considerably and
can  be handled easily  by conventional- land disposal methods.  For
further  information on solid waste  incineration see Section  4.15.2.

          Salvage and  reuse is. another solid waste disposal method
which has recently received more attention.  Increasing costs of
both waste disposal and raw materials make recycling economically
attractive as well as  environmentally beneficial.  For an  over-
view of the various solid waste disposal methods used in Industry
see Table 4.15-2.
                               443
-------
    TABLE A.15-1.   INDUSTRIAL WASTEWATER TREATMENT  METHODS1
PHYSICAL TREATMENT
  1) Gravity separation
     a) Oil separation
     b) Sedimentation
  2) Stripping processes
  3) Solvent extraction
  4) Adsorption
  5) Combustion
  6) Filtration

BIOLOGICAL TREATMENT
  1) Activated sludge
  2) Trickling filter processes
  3) Aerated lagoons
  4) Waste stabilization ponds
                      t
OTHER METHODS
  1) Dilution
  2) Deep well' disposal
  3) Ocean disposal
  4) Submerged combustion
  5) Incineration
  6) Discharge into municipal
     sewerage systems
CHEMICAL TREATMENT
  1) Neutralization and pH
     adjustment
  2) Coagulation and precipitation
  3) Oxidation processes
  4) Ion exchange

REDUCTION OF WASTE LOADS BY
INTERNAL IMPROVEMENTS
  1) Reduction of raw material
     losses
  2) Recovery of usable reaction
     products
  3) Process modifications
  4) Water reuse
  5) In-plant control  ••
  6) Waste stream segregation
                                     444
-------
                       TABLE 4.15-2.   INDUSTRIAL  SOLID WASTE DISPOSAL METHODS
                                                                                         2 , 3
Ui

Land
a>
b)
c)
d)
Disposal Method
Disposal
Lagoon
Spread on land
Sanitary landfill
Duop

Water Aahds, Flyasb
Treatment 1 Incinerator
Sludge Residue Plastic

X
X X
t X X
XXX
Waste Type
Organic
Catalysts Cheaiicals

x x
X X
X
X

Inorganic
Chemicals

X
X
X

Sludges,
Filter Cakes.
Viscous Solids

X
X
X
X
Incineration
a)
b)
c)
d)
*)
f)
Ocean
»>
b)
Open pit
Rotary kiln
Stationary hearth
Multiple hearth
Liquid burner
Fluidized bed reactor
Disposal
Bulk dunping
Sealed container
I
X
X
X

X




X

x
X

X
X

X

X
X

X
X

X
X

X



                  dumping







              Chemical Treatment




              Biological Treatment




              Salvage & Recycle
-------
4.15.1.1  Emission Characteristics

          The amount of hydrocarbon and solvent vapor emissions
resulting from industrial waste disposal practices is not well
known.  Emissions from gaseous wastes are relatively small if
blowdown systems are controlled and flares operated properly.
Emissions associated with liquid and solid wastes can be ap-
preciable.

          Uncovered drainage and wastewater systems allow
evaporation of organics and hydrocarbons.   A drainage system
usually consists of collection systems and interceptor systems.
The collection system is a series of small lines with trapped
inlets and open ditches that carry wastewater from small in-
stallations such as pumps to junction (sewer) boxes.  In
refineries, there are also oily water sumps for the collection
of polluted waters in remote areas.  These sumps are simply
large, open boxes with oil skimming devices.

          The interceptor system is made up of large concrete
or corrugated steel trunk drains which lead to the wastewater
treatment plant through several liquid-sealed sewer boxes.
The manholes for the sewer boxes are usually equipped with
vented covers or elevated standpipes.  Excess flows of waste-
water are typically sent to open holding basins and final
wastewater effluent is discharged to large lagoons ."*

          Any part of the drainage system that conveys contam-
inated water and is open to the atmosphere is a potential source
of emissions (see Section 4.2.3, Oil-Water Effluent Systems).
Factors which determine the amount of emissions are concentra-
tion, volatility, temperature, and agitation.  For a refinery
it has been estimated that uncontrolled organic emissions from
                              445
-------
process drains and wastewater separators average 0.30 g/2, (105
lb/103bbl) of refinery feed.  Maximum emissions are 0.57 g/4
(200 lb/103bbl).5

          As with liquid wastes, the major emissions resulting
from solid waste disposal occur from processes or operations
which are open to the environment.  Possibly the most signifi-
cant example is the open pit dumping of sludges, filter cakes,
and organic chemicals.  Waste units open to the atmosphere in
petroleum refineries include gravity or mechanical thickeners--•-•
dissolved air flotation units, aerobic sludge digesters, drying
beds and evaporation ponds.  Evaporative losses occur from all
of these units, but emissions have not been quantified.

4.15.1.2  Control Technology

          Hydrocarbon and organic solvent emissions from waste
handling and disposal can best be reduced by minimizing the
amount of waste to be treated.  The volume of waste can be
minimized through modern process design, proper plant mainte-
nance, and general good housekeeping.

          Waste reduction often involves extensive process
modifications and/or extreme capital expenditures.  The next
best alternative is to modify existing waste disposal systems
to insure better emissions  control.  Enclosing wastewater
systems produces a dramatic reduction in hydrocarbon emissions.
Controls include covered ditches, catch basin liquid seals, and
fixed or floating roofs on  oil-water separators.  There is also
some potential for lowering the temperature of wastewater to
reduce evaporation or for installing vapor recovery devices on
certain equipment -such as oil-water separators.  According to
studies on refineries in Los Angeles County, organic emissions
                               447
-------
from controlled wastewater systems can be as low as 30 mg/fc
(0.01 Ib/bbl) of refinery feed.6  This represents a 90% reduction
in emissions from the average refinery wastewater system.  The
same can be said for solid waste disposal systems.  Enclosure
of solid wastes containing volatile pollutants and proper
incineration are excellent measures for reducing emissions.

4.15.1.3  Cost, Energy, and Environmental Impact of Controls

          Wastewater drainage systems and oil-water separators
are discussed in Section 4.1.10 and 4.2.3,, respectively.

4.15.2    Solid Waste Incineration

          .According to the Solid Waste Disposal Act of 1965,
the term "solid waste" is defined as garbage, refuse, and other
discarded solid materials resulting from industrial, commercial,
and agricultural operations, and community activities.  Such
wastes may or may not be combustible.7  Incineration has long
been an economical way of reducing the total volume of solid
waste requiring disposal.  According to one source, an incin-
erator fill site requires less than one sixth the volume neces-
sary for sanitary disposal of compacted crude refuse.6

          There are varied estimates of the actual amount of solid
waste incinerated in the United States.  One estimate states that
the per capita generation rate of urban and industrial waste is
approximately 4.5 kg/day (10 Ib/day), half of which is burned.9
This combustion is accomplished in several different types of
incinerators.  Very little open burning is allowed today.

          Municipal incinerators have capacities greater than
45.3 Mg/day (50 tons/day) and are usually equipped with automatic
charging mechanisms, temperature controls, and movable grate systems.1


                               448
-------
          Industrial and commercial incinerators have capaci-
ties ranging from 22.7 kg/hr to 1.8 Mg/hr (50 Ibs/hr to 2 tons/
hr) and may be either single or multiple-chamber in design.
Some resemble municipal incinerators and most are often manual-
ly charged and intermittently operated.  These units have well
designed emission control systems such as gas-fired after-
burners and scrubbers.ll

          A trench incinerator is simply a horseshoe shaped
pit.  Air nozzles located along the top edge of the pit and
directed slightly downward provide both an air curtain across
the top of the pit and air for combustion within the pit.  The
trench incinerator was originally designed for the combustion
of wastes which have relatively high heat content and low ash
content.  Trench incinerators are used for other purposes due
to the low construction and operating costs.

          Domestic incinerators are designed for residential
use and typically have single or multiple chambers with an
auxiliary burner to aid combustion.

          Flue-fed incinerators are commonly found in large
apartment buildings where the tenants dispose of refuse through
an incinerator flue into the combustion chamber.  Some flue-fed
incinerators- are equipped with afterburners and draft controls.

         'Pathological incinerators are used for the disposal
of animal remains and other high moisture organic material.
Typical units have capacities ranging from 22.7 to 45.4 kg/hr
(50 to 100 Ib/hr.) and are equipped with combustion controls and
afterburners.:2
                             449
-------
          Controlled air incinerators have a two chamber design.
In the first chamber wastes are burned without a complete
supply of oxygen to produce a highly combustible gas mixture.
Combustion is completed in the second chamber with the addition
of excess air.   These units employ automatic charging devices
and frequently exhibit high effluent temperatures.

           Conical  burners  are truncated metal cones with a
 screened top vent.   Charging to  a raised  grate is  accomplished
 by either a bulldozer or  conveyor belt.   Additional combustion
 air is  provided by underfire air blown below the grate and  over-
 fire air introduced through peripheral openings in the shell.13

               Sewage sludge incinerators  are usually either
 multiple hearth or fluidized bed units.   In a multiple hearth
 furnace the sludge enters  the top and is  dried by contact with
 hot combustion gases rising from the lower hearths.  The sludge
 is burned as it slowly moves down and the ash residue is re-
 moved at the bottom.  Temperatures for multiple hearth furnaces
 approach 540°C to  650°C (1000°F  to 1200°F) at the inlet, peak
 at about 760°C to  1100°C  (1400°F to 2000°F) in the central
 hearths, and finally drop  to 320°C (600°F) in the ash residue.
 In a fluidized bed reactor, combustion occurs in a hot, sus-
 pended bed of  sand and much of the ash residue is discharged
 with the flue  gas.   Fluidized bed reactors have fairly uniform
 temperatures ranging from 680°C  to 820°C  (1250°F to 1500°F).
 Either furnace may require supplemental  fuel for startup or
 incineration of high moisture sludge. 1 * '15' *6


           Open burning is  still  practiced for the disposal  of
 municipal waste, auto body components, landscape refuse,
 agricultural field refuse, wood  refuse,  and bulky industrial
                                450
-------
refuse.  The burning can be done in open drums or baskets,
fields, or large open pits.17

4.15.2.1  Emission Characteristics

          Organic emissions from solid waste incineration
depend on several factors  including the operating conditions,
refuse composition and moisture content, basic incinerator
design, and level of maintenance.  For instance, the relatively
low  temperatures associated with open burning are operating
conditions which increase  the emission of hydrocarbons.  As
another example, conical burners are often missing  doors arid
"have-numerous .holes in the shell due to poor maintenance.  -The ••
result is excess air, low. .temperatures, and high emission rates
of combustibl-e  organics.

          Typical emission factors for organics from various
types  of solid  waste incineration are given in Table 4.15-3.
These  factors should be used with caution as they represent
.intermediate  values; higher or  lower emissions could result
depending on  the factors previously mentioned.

4.15.2..2  Control Technology

          The best means of  controlling  emissions  from solid
waste  disposal  is  to  incorporate  an  efficient  incinerator design
 (multiple chamber),  proper operating  conditions,  and conscien-
 tious  maintenance.   Underfire  air which  might  disturb  the com-
 bustion  bed should be  avoided.  Auxiliary  burners  and tempera-
 ture controls should be  used  to maintain proper  combustion tem-
 perature.   If necessary,  gas-fired  afterburners  should be used
 to  insure complete  combustion.  A rigorous  inspection and repair
 program  can eliminate  uncontrolled  sources  of  excess  air.
                              45'1
-------
       TABLE 4.15-3.  EMISSION FACTORS FOR VARIOUS TYPES OF
                      SOLID WASTE INCINERATION18"*2
                                                  Emission Factor
                                                                 a,b
Source
g/kg
Ib/ton
Municipal Refuse Incinerator

   Multiple chamber,  uncontrolled                 0.75
   With settling chamber  & water spray system     0.75

Industrial/Conmereial Incinerator

   Single chamber                                7.5
   Multiple chamber                              1.5
   Controlled air                                Keg.

Flue-fed Single Chamber Incinerator               7.5

Flue-fed Modified Incinerator
   (with afterburners and draft controls)         1.5

Domestic Single Chamber Incinerator

   Without primary burner                        50
   With primary burner                           1

Pathological Incinerator                          Seg.

Conical Burners
               1.5
               1.5
               15
               3
               Seg.

               15
               100
               2

               Neg.
Municipal refuse
Wood refusec
d
Sewage Sludge Incinerator
Uncontrolled
After scrubber
Open Burning
Municipal refuse
Automobile components
Unspecified field crops
10
5.5


0.75
0.5

15
15
12
20
11


1.5
1

30
30
23
a - total organics expressed as  units  of methane per unit of waste incinerated
b - average factors based on EPA procedures for incinerator stack testing
c - moisture content as fired is approximately 50 percent
d - unit weights in terms of dried  sludge
e - upholstery, belts,  hoses, and tires burned in common
                                   452-
-------
            Only minimal  gaseous  emission reductions  result from
  retrofitted particulate control equipment.   One  source  reported
  a 33% reduction in hydrocarbon  emissions when a  scrubber was
  installed on a sewage sludge incinerator.1*'3

  4.15.2.3  Cost,  Energy, and Environmental Impact of Controls

            Gas-fired afterburners are discussed under incineration
  in Section 3.1.

  4.15.3    References

  1.  Gloyna, E. F., and  D.  L. Ford,  Petrochemical Effluents
      Treatment Practices.  FWPCA.  U.S.  Department of the Inter-
      ior.  Program No. 12020.  Contract  No.  14-12-461.   February
      1970.

  2.  Makela, R. G., and  J.  F. Malina, Jr.  Solid  Wastes  in the Peti
      chemical Industry.   Center for Research in Water Resources,
      Civil Engineering Dept.., The University of Texas at Austin.
    .  Augusti 1972,

  3.  Ma'rynowski,  C. W.  Disposal of Polymer Solid Wastes 'by Primary
      Polymer Producers and Plastics Fabricators.   U.S.  Environ-
      mental Protection Agency.  SW-34c.   1972.

  4.  Rosebrook, D.  D., et al.  Sampling Plan for  Fugitive Emis-
      sions from Petroleum Refineries.  Radian Corporation.
      Austin, Texas.  January 24, 1977.

5-6.  Burklin, C.  E., et  al.   Control of Hydrocarbon Emissions
      from"Petroleum Liquids.  U.S. Environmental  Protection
      Agency.  September, 1975.
                                453
-------
    7.  Environmental Protection Agency.   Compilation of Air Pollu-
        tion Emission Factors.   2nd edition with supplements.
        Research Triangle Park,  North Carolina.   AP-42.   1973.

    8.  Hrudey, S.  E. and R.  Perry.  Assessment of Organic Content
        of Incinerator Residues.  Environmental Science  and Technology.
        Vol. 7, No. 13.  December 1973.

    9.  Nationwide Inventory of Air Pollutant Emissions, 1968.   U.S.
        DREW, PHS,  EHS.  National Air Pollution Control  Administra-
        tion.  Raleigh, NC.   Publication No. AP-73.  August 1970.
        As cited in Reference 7.

   10.  Air Pollutant Emissions Factors,  Final Report.  Resources
        Research, Inc.  Reston, Va.  Prepared for National Air Pollu-
        tion Control Administration, Durham, NC.  Contract No.  CPA-
        22-69-119.   April 1970.   As cited in Reference 7.

11-13.  Reference 10.

   14.  Calaceto, R. R.  Advances in Fly Ash Removal with,Gas-Scrub-
        bing Devices.  Filtration Engineering.  1(7):12-15, March 1970.
        As cited in Reference 7.

   15.  Balakrishnam, S., et al.  State of the Art Review on Sludge
        Incineration Practices.  Federal Water Quality Administration.
        Washington, D.C.  FWQA-WPC Research Series.  As cited in
        Reference 7.
                                  454
-------
16.   Canada's Largest Sludge Incinerators Fired Up and Running.
     Water Pollution Control.   107(1):20-21,  24.   January 1969.
     As cited in Reference 7.

17.   Reference 10.

18.   Danielson, J.  A. (ed.).  Air Pollution Engineering Manual.
     U.S. DREW, PHS National Center for Air Pollution Control.
     Cincinnati, Ohio.  Publication Number 999-AP-40.  1967.
     p. 413-503.  As cited in Reference 7.

19.   Kanter, C. V., R. G. Lunche, and A. P. Fururich.  Techniques
     for Testing for Air Contaminants from Combustion Sources.
     J. Air Pol. Control Assoc. 6(4):191-199.   February 1957.
     As cited in Reference 7.

20.   Fernandes, J.  H.  Incinerator Air Pollution Control.  Pro-
     ceedings of 1968 National Incinerator Conference, American
     Society of Mechanical Engineers.  New York.  May 1968.
     p. 111.  As cited in Reference 7.

21.   Unpublished -data on.-incinerator testing.  U.S. DHEW, PHS, .EHS,
     National Air Pollution Control Administration.  Durham, NC;"
     1970.  As cited in  Reference 7.

22.   Stear, J. L.  Municipal Incineration:  A Review of Literature.
     Environmental Protection Agency, Office of Air Programs.
     Research Triangle Park, NC.  OAP Publication Number AP-79.
     June 1971.  As  cited in Reference  7.

23.   Kaiser, E. R.,  et al.  Modifications  to Reduce Emissions from
     a Flue-fed Incinerator.  New York  University.  College  of
     Engineering.  Report Number 552.2.   June 1959.  p. 40  and 49.
     As cited  in Reference  7.
                                455
-------
24.   Unpublished data on incinerator emissions.   U.S.  DHEW,  PHS,
     Bureau of Solid Waste Management.   Cincinnati,  Ohio.   1969.
     As cited in Reference 7.

25.   Kaiser, E.  R.   Refuse Reduction Processes in Proceedings ,of
     Surgeon General's Conference on Solid Waste Management.
     Public Health Service.  Washington, B.C.  PHS Report Number
     1729.  July 10-20, 1967.   As cited in Reference 7.

26.   Nissen, Walter R.  Systems Study of Air Pollution from
     Municipal Incineration.  Arthur D. Little,  Inc. Cambridge,
     Mass.  Prepared for National Air Pollution Control  Adminis-
     tration.  Durham, N.C., under Contract Number CPA-22-69-23.
     March 1970.  As cited in Reference 7.

27.   Unpublished source test data on incinerators.  Resources
     Research, Incorporated.  Reston, Virginia.   1966-1969.
     As cited in Reference 7.

28.   Communication between Resources Research, Incorporated,
     Reston, Virginia, and Maryland State Department of Health,
     Division of Air Quality Control, Baltimore, Md.  1969.  As
     cited in Reference 7.

29.   Magill, P.  L.  and R. W..Benoliel.   Air Pollution in Los
     Angeles County:  Contribution of Industrial Products.  Ind.
     Eng. Chem.  44:1347-1352.   June 1952.  As cited in Reference  7.

30.   Private communication with Public Health Service, Bureau of
     Solid Waste Management.  Cincinnati, Ohio.   October 31, 1969.
     As cited in Reference 7.

31.   Anderson, D. M., J. Lieben, and V. H. Sussman.   Pure Air
     for Pennsylvania.  Pennsylvania State Department of Health,
     Harrisburg.  November 1969.  p. 98.  As cited in Reference 7.
                                 456
-------
32.   Boubel,  R.  W.,  et al.   Wood Waste Disposal and Utilization.
     Engineering Experiment Station,  Oregon State University,
     Corvallis.   Bulletin Number 39.   June 1958.   p. 57.   As cited
     in Reference 7,

33.   Netzley, A. B.  and J.  E.  Williamson.   Multiple Chamber In-
     cinerators  for Burning Wood Waste.  In: Air Pollution Engin-
     eering Manual,  Danielson, J.A.  (ed.).  U.S.  DREW, PHS,
     National Center for Air Pollution Control.  Cincinnati, Ohio.
     PHS Publication Number 999-AP-40.  1967.  p. 436-445.  As
     cited in Reference 7.

34.   Droege,  H.  and G. Lee.  The Use of Gas Sampling and Analysis
     for the Evaluation of Teepee Burners.  Bureau of Air Sanita-
     tion.  California Department of Public Health.  (Presented at
     the 7th Conference on Methods in Air Pollution Studies,, Los
     Angeles.  January 1965.)   As cited in Reference 7.

35.   Boubel,  R.  W.   Particulate Emissions from Sawmill Waste
     Burners.  Engineering Experiment Station.. --Oregon State Uni-
     versity, Corvallis.  Bulletin Number 42.  August 1968.
     p. 7-8.   As cited .in Reference 7..

36.   Gerst-1-e, R. W.  and--D.  A,  .Kemnit.z»  Atmospheric Emissions from
     Open Burning.   JVAir"Pol. Control Assoc. 12:324-327.  May
     1967.  As cited in Reference 7.

37.   Burkle,  J.  0., J. A. Dorsey, arid B. T. Riley.  The Effects
     of Operating Variables and Refuse Types on Emissions from
     a Pilot-Scale Trench Incinerator.  In: Proceedings of 1968
     Incinerator Conference, American Society of Mechanical
     Engineers.   New York.   May 1968.  p. 34-41.  As cited in
     Reference 7.
                                 457
-------
38.   Weisburd,  M.  I.  and S.  S.  Griswold (eds.).   Air Pollution
     Control Field Operations Guide:   A Guide  for Inspection r.nd
     Control.  U.S.  DHEW,  PHS,  Division of Air Pollution,  Wash-
     ington, D.C.   PHS Publication No. 937.   1962.   As cited in
     Reference 7.

39.   Unpublished data on estimated major air  contaminant emissions.
     State of New York Department of Health,  Albany.  April 1,
     1968.  As cited in Reference 7.

40.   Darley, E. F. ,  et al.   Contribution of Burning of Agricul-
     tural Wastes to Photochemical Air Pollution.  J. Air Pol.
     Control Assoc.   16:685-690.  December 1966.  As cited in
     Reference 7.

41.   Darley, E. F. ,  et al.   Air Pollution from Forest and Agri-
     cultural burning.  California Air Resources Board.  Project
     2-017-1, University of California, Davis, Calif.  California
     Air Resources Board Project No.  2-017-1.   April 1974.  As
     cited in Reference 7.

42.   Darley, E. F.  Progress Report on Emissions from Agricultural
     Burning.  California Air Resources Board Project 4-011.
     University of California, Riverside, Calif.  Private commun-
     ication with permission of Air Resources Board.  June 1975.
     As cited in Reference 7.

43.   Source Test Data from Office of Air Quality Planning and
     Standards.  U.S. Environmental Protection Agency, Research
     Triangle Park,  N.C. 1972.  As cited in Reference 7.
                                458
-------
4.16      Food Processing

          Organic emissions are produced from varied sources in
the food processing industry.  Table 4.16-1 lists some important
source categories and their yearly estimated emission rates.
Eight food processing operations are discussed separately in
Sections 4.16.1 through 4.16.8.  These are not the only sources
of emissions, but they are the only ones for which data were
found.  Animal food processing, meat slaughtering, and inedible
fat and tallow rendering are not covered.

4.16.1    Coffee Roasting

          -•Coffee processing begins with the imported green bean
wh'ich is cleaned, blended, roasted, -and packaged for sale.  Only
thirty percent -of the raw material is-processed into instant
coffee, and 5 percent is decaffeinated with trichloroethylerie
prior to roasting.1  Volatile organics are emitted during roast-
ing and decaffeination.  Table 4.16-2 lists estimated emissions
of organic compounds for continuous and batch roasters.  Emis-
sions can be almost completely eliminated by a direct-fired
afterburner operating in the range of 650-750°C (1200-1400°F).2
Solvent loss (trichloroethylene) is the main emission from  the
decaffeination step.  No solvent control techniques are used.3
Afterburners are discussed under incineration in Section  3.1.

4.16.2    Alcoholic Beverage Production

          Whiskey production is the main emphasis of this section.
Wine and beer production involve virtually no volatile organic
emissions. ** ' 5  The four main production stages in whiskey manufac-
turing are 1) brewhouse operations, 2) fermentation, 3) aging,
and 4) packaging.
                               459
-------
      TABLE 4.16-1.   ESTIMATED VOLATILE ORGANIC EMISSIONS
               FROM THE FOOD PROCESSING INDUSTRY
Emission Source
Coffee Roasting
Distilled Liquor
Vegetable Oil
Fruit and Vegetable Processing
Deep Frying
Fish and Seafood Processing
Meat Smokehouses
Year
1974
1973
1976
1973
1975
1973
1975
Emissions
Mg/yr (tons/yr)
1,400 ( 1,500)
10,600 (11,700)
10,300 (11,400)
47,700 (52,500)
6,090 ( 6,700)
745 ( 820)
462 ( 510)
Reference
6
7
8
9
10
11
12
TABLE 4.16-2.  COMPOSITION OF EMISSIONS FROM COFFEE ROASTING13
                           Aldehydes
                              ppm
              Organic Acids
                  ppm
Batch Roaster
Continuous Roaster
 42
139
175
223
Of these, only aging results in significant organic emissions.
A rough estimate for aging emissions is 24 kg/m3 of whiskey
stored (10 Ib/bbl of whiskey stored).1"  Emission controls are
not applied.l5
                               460
-------
4.16.3    Flavors and Essential Oils

          Food flavorings can be defined as 1) spices and herbs,
2) fruit and fruit juices, 3) essential oils and extracts, and
4) aliphatic, aromatic, and terpene compounds.  Volatile organic
emissions arise only from producing the latter two categories,

          Essential oils are produced in large-scale operations
by steam distillation or by solvent extraction of botanical ma-
terial.  The solvent used may be benzene (with or without added
acetone and petroleum ether), liquified butane gas, or alcohol.
Solvent is recovered by distillation because it is expensive.
The residual material (concrete) is then extracted with alcohol,
filtered to remove wax,, .and redistilled.: 6  No estimates of
volatile organic emissions are available, but they are probably
similar to tho.se for botanical extractions in the pharmaceutical
industry (Section 4.11).

          Aliphatic, aromatic., terpene, and other organic com-
pounds are- ;used as artificial flavorings.  These compounds'-may
be synthesized or extracted 'from .food material.  Emissions from
synthetic compounds would be similar -to those described for the
organic chemicals in Section 4,4.  Available emission rates for
some synthetic"'flavoring compounds are given in Table 4.16-3.

          Compounds that are extracted from food materials are
produced by distillation or extraction.  Emissions vary widely
due to processing differences.  One example of emissions of this"
sort is 2-Propanol, used to extract lemon pulp in a California
plant.  Solvent concentrations in process exhaust were 8300 ppm.17
This type of solvent loss can be eliminated with the use of a
carbon adsorption system.  Adsorption is discussed in Section  3.2.
-------
          TABLE 4.16-3.  ORGANIC EMISSIONS FROM PRODUCTION
                   OF ARTIFICIAL FOOD ADDITIVES18

Sorbitol
Saccharin
Saccharin - via toluene
Monosodium Glutamate



sulfonatnide

Organic
Mg/yr
26.6
0.4
0.7
9.6
Emissions
(tons/yr)
(29.3)
( 0.44)
( 0.77)
(10.6)
4.16.4    Fruit and Vegetable Processing

          Fruits and vegetables from the field undergo several
processing steps before sale either as a canned or frozen product
or as a fresh commodity.  The fruit or vegetable must first be
washed and sorted.  If the final product is canned or frozen,
subsequent processing includes peeling, slicing, blanching,
cooking, cooling, and preserving.  Fresh products are sometimes
exposed to heat, moisture, ethylene, and oil-soluble dyes to
promote ripeness and improve color.

          Organic emissions occur from processing operations.
Probable significant sources are cooking operations and arti-
ficial ripening of the fruits and vegetables.  One 1975 esti-
mate for yearly emissions was 21 Gg (23,000 tons) from fruit
and vegetable freezing, 26 Gg (29,000 tons) from canning opera-
tions, and 544 Mg (600 tons) from artificial ripening.19  Appli-
cable control techniques are incineration and adsorption.  In-
cineration and adsorption are discussed in Section 3.1 and 3.2,
respectively.
                               462
-------
4.16,5    Fats and Oils

4.16.5.1  Animal ...Fats

          Animal fats are of two major types,  rendered and
unrendered.   Unrendered fats such as butter require no cooking.
Production of unrendered fats does not produce organic emissions.
Rendered fats are those obtained by cooking and pressing fatty
animal tissues.   United States consumption of these oils for
1971 totaled 942 Gg (1045 x 103 tons).*0

          Animal fats are rendered by dry, wet, or digestive
processes.  Dry rendering is the simplest and involves heating
the very finely ground oil stock to 110CC (230°F).  Heating
melts the fats and dehydrates the residual connective tissue
which is easily strained and pressed free of fat.21  Wet ren-
dering is carried out in the presence of large quantities of
water.  Melted fat rises to the surface of water and is skimmed
off.  .Digestive rendering is carried out at low temperatures
by chemicals or enzymes and is not widely used.

          Organic emissions are produced by the rendering pro-
cesses.  Emission rates are low but the emissions are noticeable
because of odor-.problems,  The use of spray contact condensers
is recommended as an effective control device.22  Condensers
are discussed in Section 3.2.

4.16.5.2  Vegetable Oils

          The major vegetable oils processed in the United
States are soybean, cottonseed, corn, peanut,  linseed, and saf-
flower oil.  Table 4.16-4 lists consumption for the major vege-
table oils in 1971.
                                463
-------
       TABLE 4.16-4.  U.S. VEGETABLE OIL CONSUMPTION FOR 1971
                                                             2 3
Oil
Soybean
Cotton seed
Corn
Peanut
Palm
Palm kernel
Olive
Saf flower
Coconut
Other
TOTAL
Gg
2617
334
176
83
71
31
28
15
3
159
3517
(W6 Ibs)
(5816)
( 717)
( 391)
( 184)
( 158)
( 69)
( -62)
( 33)
( 7)
( 354)
(7791)
          The processes for oil production are 1) preliminary
treatment, 2) oil extraction, and 3) oil refining.  Mechanical
crushing to release the oil is the method generally used on
seeds of high oil content.  Solvent extraction is used mainly
to remove soybean oil although- it may be applied to cotton, flax,
or corn germs.  Hexane is the usual solvent; trichloroethylene
is used for small batches.    ...

          The vegetable oil industry is estimated to have emitted
10.3 Mg (11.4 x 103 tons) hydrocarbons in 1976. 21t  Major emission
points are the basket extractors, miscella  (oil/solvent mixture),
desolventizer toaster and stripper column, solvent pumps, miscella
pumps, and the operation involving recovery of solvent from meal.z5

          Because of the high cost of solvent, recovery techniques
are employed.  Hexane may be recovered with condensers and oil ab-
sorption units, or, in older plants, ir> carbon adsorbing towers.
In a few cases, recovered hexane has been burned  in an afterburner.26
These control methods are discussed in Section 3.0.

                                464
-------
4.16.5.3  Refining and Bleaching

          Refining by liquid-liquid extraction, deodorizing, and
bleaching processes is used to improve color and flavor of both
animal and vegetable oils.  Liquid-liquid extraction is used to
bleach and refine inedible tallows and greases, field damaged
vegetable oils, or other very dark oils.  Good solvent recovery
                        2 7
techniques are employed.    Organic emissions are probably  compara-
ble to those from solvent extraction of soybean and castor bean
oil.  Caustic refining may produce emissions of low boiling fatty
acids, but no information on emissions was found.

          Adsorbent bleaching is used for both edible and in-
edible oils..  Natural bleaching earth (Fuller's Earth), acid-
activated clays, or activated carbon are used.  Amounts varying
from 0.25% (for lard) to 5% (for dark-colored inedible tallows
and greases) of the amount of oil to be bleached are required.
The spent earth retains a certain amount of oil  (20-457* of  their
own weight).  The earth is usually discarded without treatment
because the recovered oil is of low purity.  The oil can be re-
covered by prolonged boiling in a weakly .alkaline--solution.
Boiling reduces the oil Ixist from 30-407. to only ''6-87» of the
input material .2 8

          The deodorization process is used to remove undesirable
flavors and odors from oils used in salad oils and margarines.
The oils are steam stripped to remove ketones, terpenoid hydro-
carbons, and unsaturated aldehydes.  These compounds usually
constitute less than 0.17. of the total weight of the oil.29  No
attempt is made to recover these compounds.
                               455
-------
4.16.6    Meat Smokehouses

          The smoking of meat, fish,  or poultry is an ancient
method of preserving food.  Today, it is used mainly to impart
flavor and color to specific food products.   Smoke is produced
by the burning of damp or dry sawdust.   The smoke is usually re-
circulated at high temperatures.30  Table 4.16-5 lists the com-
ponents of a typical wood smoke used in a meat smokehouse.  Even
with smoke recirculation, emissions do occur (see Table 4.16-1.)
The rate and composition of emissions are dependent on the type
of wood, type of smoke generator, moisture content of the sawdust,
air supply, and degree of recirculation.  Emission factors are
given in Table 4.16-6.  Direct-fired afterburners can be used to
reduce emissions significantly.31  Afterburne-rs are discussed
under incineration in Section 3.1.

 TABLE 4.16-5.  ANALYSIS OF WOOD SMOKE USED IN MEAT SMOKEHOUSES32
                                         Concentration
     Component
Formaldehyde                                 20-40
Higher aldehydes                            140-180
Formic acid                                  90-125
Acetic and higher acids                     460-500
Phenols                                      20-30
Ketones                                     190-200
Resins                                       1,000

4.16.7    Fish Processing

          The fish processing industry includes two major segments,
the canning, dehydration and smoking of fish for human consumption,
and the manufacture of by-products such as fish meal and oil.  A
large fraction of the fish received in a cannery is processed into
by-products . 3 5
                               466
-------
       TABLE 4.16-6.  EMISSION FACTORS FOR MEAT SMOKING35'3"
Emission Factor3
Uncontrolled Controlled*5
'Organic Compound
Hy dr o c arb on s
Aldehydes
Organic acids (Acetic )
g/kg
of meat
0.035
0.04
0.10
(Ib/ton
of meat)
(0.07)
(0.08)
(0.2)
g/kg
of meat
tfeg
0.025
0.05
(Ib/ton
of meat)
(Neg)
(0.05)
(0.1)
aFactors considered "Below Average" according to definition  in
 Introduction to Reference 4,
 Controls are either a wet collector and low voltage preclpitator
 in series or a direct-fired afterburner.

          The.major sources of 'organic emissions in the cannery
are the cooker, presser..and grinders ,-and rotary-dryers.3'6   All...
fish products are cooked before furth-er processing.^ ^r*'

          The principal component of organic emissions  is,tri-
methylamine,  (CH3)3N.  Table 4.16-7 lists emission rate.s* for
                                                       '•. <*
cookers processing fish for fish meal, production.  Rates may
vary -depending on the type of fish being cooked.  Cookes-i«ri[f gases
are usually passed through a contact condenser prior to venting
to remove water vapors and oils.37  Condensers are discussed in • ,
Section 3'.4.

   TABLE 4.L6-7.  TRIMETHYLAMINE EMISSION FACTORS FOR  COOKERS •
                       USED IN FISH MEAL PRODUCTION38
Material Coo'ked
Fresh Fish
Stale Fish
Tr ime thy 1 amin e Etai s s ions a
g/kg of fish (Ib/ton of fish).
0.15
1.75
(0.3)
(3.5)
"Factors rated "Average" according  to  Introduction  to  Reference 4
                               467
-------
4.16.8    Food Cooking Operations

          The cooking of food releases organic vapors.   Restaur-
ants, bakeries, and candy making operations produce the greatest
volume of emissions.

          Kitchen emissions from restaurants come from the
grill and fryer, vegetable cookers, and steam tables.   One
source estimates a total emission rate for restaurants of 0.72
kg/day/1000 people (1.6 lb/day/1000 people) but does not differ-
entiate between volatile organic, particulate, or aerosol emis-
sions.  The identity of the hydrocarbon .varies with the food
being cooked.  Acrolein is present in emissions from frying
operations.39  Deep frying is a major source of emissions as
shown in Table 4.16-1.  Carbon adsorption is an accepted method
for pollution control.1*8  Adsorption  is discussed in Section 3.2,

          Baking and candy manufacturing operations emit low
concentrations of organics.  The main identified constituent of
emissions from the baking industry is ethanol.  The roasting of
cocoa beans is the main source of emissions.*1  No quantitative
data were found for this source.

4.16.9    References

1.  Engineering Science, Inc.  Exhaust Gases from Combustion and
    Industrial Processes.  Washington, B.C.  AFTD-0805.  October
    2, 1971.  436 p.

2.  Lund, H. F.  Industrial Pollution Control Handbook.  New
    York, McGraw Hill, 1971.

3.  Reference 1.
                               468
-------
 4.   Environmental Protection Agency.   Compilation of Air Pollu-
     tion Factors,  Second Edition with Supplements.   Office  of
     Air Quality Planning Standards.   Research Triangle Park,
     North Carolina.   Publication Number AP-42.  February 1976.
     462 p.

 5.   Memo from Ed Vincent to Jim Berry (EPA),  June 27, 1977.

 6.   Reference 4.

 7.   Overview Matrix.   Monsanto Research Corp.  Dayton, Ohio.
     Contract Number 68-02-1874.  July 1975.

 8.   Sharpe, Lonnie.   Background Information  on the Vegetable
     Oil Industry, unpublished paper.   U.S. EPA.  August 1977.

 9.   Reference 7.                    .

10..   Hopper, T.  G. and W. A. Marrone.   Impact of New Source
     Performance-Standards on 1985 National 'Emissions from ""
     Stationary Sources,  Volume I.  Final Report.  TRC, The
     Research Corporation-of New England;" Weth'efsfeld, Conn.
     Contract No. 68-02-1382.  October 1975.

11.   Reference. I-..-..

12.   Reference 10.

13.   Polglase, V. L.,  H.  F. Dey, and R. T. Walsh.  Food'Processing
     Equipment.   -In:   Air Pollution Engineering Manual, J. A.
     Danielson (ed.).   U.S. DHEW, PHS, National Center for Air.
     Pollution Control.  Cincinnati,  Ohio.  Publication Number
     999-AP--4Q,	1967.  p; 791-829.
                                469
-------
14-15.  Reference 4.

   16.  Stoll,  M.  Essential Oils.   In:   Kirk-Othmer  Encyclopedia
        of Chemical Technology.  Vol.  14,  2nd Ed.   New York,  John
        Wiley and Sons,  Inc., 1967.   p.  178-216.

   17.  Package Sorption Device  System Study.  Environmental Protec-
        tion Agency,  Office of Research and Monitoring.   Research
        Triangle Park,  N.C.  EPA-R2-73-202.   April 1973.   506 p.

18-19.  Reference 7.

   20.  Fats and Oils.   In:  Chemical Economics Handbook.% Menlo
        Park, California, Stanford Research Institute, 1972.  p. 220.
        9600B.

   21:  Bailey, A. E.  Industrial Oil and Fat Products.   New York,
        Interscience Publishing, Inc., 1957.

   22.  Reference 13.

   23.  Reference 20.

24-26.  Reference 8.

27-28.  Reference 20.

   29.  Norris, F. A.  Fats and Fatty Oils.   In:  Kirk-Othmer
        Encyclopedia of Chemical Technology, Volume 8.  New York,
        John Wiley and Sons, Inc.  1965.  p. 776-811.
                                    470
-------
   30.  Reference 4.

   31.  Air Pollutant Emission Factors.  Final Report.  Resources
        Research, Inc.  Res ton, Va.  Prepared for National Air Pollu-
        tion Control Administration, Durham, N.C., under Contract
        No, CPA-22-69-119.  April 1970.  As cited in Reference 4.

   32.  Reference 13.

   33.  Carter, E.  Private communication between Maryland State-"'
        Department of Health and Resources Research, Inc.  November.
  • '  " "  21, 1969.  As cited in Reference., 4.  -            '       ,.-  '

   34".  Polglase, W. L. , H. F. Dey, and R. T. Walsh.  Smokehouses......
        In:  Air- Pollution -Engineering Manual.  Danielson, J. A.  '- -
        (ed.).  U.S. DHEW, PHS, National Center for Air  Pollution
        Control.  Cincinnati, Ohio.  Publication. Number  999-AP-40.
        1967. .p. 750-755.  As cited in Reference 4.

   35."  Walsh, R. T. , K, -D. "Luedtke, and L. K. Smith.  Fish  Canneries
        and Fish^Reduction Plants,. • In-.  Air Pollution Engineering
        Manual'.- Danielson,-J. A.--(ed.),  U.S. DHEW, PHS, National
        Center"for"Air  Pollution Control,  Cincinnati, Ohio,  Pub-
        lication Number  999-AP-40,  1967.  p. 760-770,   As cited,
        in Reference 4.

36-37.  Reference 1.

   38.  Summer, W.  Methods of Air  Deodorization.  New York.  Elsev.ie:
        Publishing  Company.  p, 284-286.  As cited in Reference  4.

39-41.  Reference 17.
                                    47:
-------
4.17      Dry Cleaning Industry

          The dry cleaning industry is a significant source of
volatile organic emissions.  The annual emission rate is esti-
mated to be 230 Gg/yr (254,000 tons/yr).*  Dry cleaning produces
1.347o of the total annual volatile organic emissions from sta-
tionary sources in the U.S.  A summary of emissions from dry
cleaning operations is included in Table 4.17-1.

          There are three types of dry cleaning establishments.
According to 1976 projections there are 540 industrial, 26,200
commercial, and 31,500 coin operated units."  These operations
differ not only in size and type of service, but also in the
type of solvent used.  These solvents are fluorocarbon, perchlo-
roethylene, and petroleum solvents.  Dry cleaning operations
for each solvent system are discussed in the following sections,
4.17.1 through 4.17.3.

4.17.1    Petroleum Solvent-Based Systems

          About 270 industrial plants and 6,200 commercial units
use petroleum solvents and consume approximately 72 Gg solvent/'
year (80,000 tons/yr).5  The two main types of solvent used are
Stoddard and 140-F.  Both are combustible, kerosene-like mix-
tures, with approximate chemical compositions of 4670 paraffins,
42% naphthenes, and 127» aromatics.  Los Angeles County Rule 66
(now SCAQMD Code #442) has led to reformulation of some solvents
to less than 87o aromatics.  Because the solvents are relatively
inexpensive (45-60c gal), there is little economic incentive  for
controlling solvent losses.

          Figure 4.17-1 is a simplified diagram of a petroleum
solvent based dry cleaning plant.  Steps in the operation include
washing, extracting, and drying.  Dryers are separate from the

                              472
-------
      TABLE 4.17-1.  SUMMARY OF VOLATILE ORGANIC EMISSIONS  FROM DRY CLEANING OPERATIONS'
LO

Solvent System
Petroleum
Solvent





I'e t c It 1 o roe th y le ne





t'tunrocaibons



Source
Dryer Evaporation

Filter Muck Retention



Miscellaneous Sources
Dryer Evaporation
After Condenser
FUtnr Muck

Miscellaneous

Dryer Fvaporat Ion
Cartridge Filters
Hiscn 1 1 aneous
En IBB Ion Level
kg7ToOkg"fi₯?100 Ib
Materials Cleaned
18

5-10



: : 4
3-6

1-14

4

0
I3
1-2

i Control Technique
Carbon adsorption.
incineration
Vacuum distillation,
centrifugal separa-
tion,., cartridge fil-
ters,, incineration
Cnod housekeeping
Carbon adsorption

Cartridge filters,
longer cooking times
Good housekeeping,
longer distillation
-
Drying in unit
-
Controlled Emission Level
kg/lOOkg (lb/100 It.)
Materials Cleaned
2-3

1 or less



1-2
0.3a

0.5-1.08

2a

-
0.5a
I-/
              llaia subsl.int IntcJ l>y KPA tests.
-------
                                                           DHV,CLEAN
                                                            CLOTHES
           | INCINERATION |
Figure  4.17-1.   Petrolettm-Solvent  based dry  clean5.ng  plant.
-------
washer and extractor.  In all new plants washing and extracting
are done in the same equipment,  A few older plants have separate
extractors.   Clothes are washed in more than one bath of solvent.
In some cases a solvent wash is followed by a water wash.  In
newer equipment, solvent is continuously filtered and returned
to the washer during a wash cycle.  Next, the clothes are spun
to extract as much solvent as possible.  Wet clothes are then
transferred to the dryer where they are tumbled in hot air.  Mos.t
dryers have a cool-down cycle to prevent wrinkling.  All dryer.,
exhaust is vented directly to the atmosphere.             ...- .

          Used solvent from the washer must be filtered-before
it can be reused.  The resulting filter muck is com'p'osed of
diatomaceous earth, carbon, -lint, detergents, oils, and solvent.
Some industrial plants incinerate this solid waste stream.  In
most -plants it is drained by gravity or vacuum press, air dried,
and discarded.6

4.17.1.1  Emission Characteristics

          The primary source of emissions are evaporation in the
dryer and .filter muck treatment. 'Estimates of these emissions
are given in Table 4.17-1.  An industry survey has estimated
total average emission rates to be 29 kg solvent/100 kg materials
cleaned.7

4.17.1.2  Control Technology

          At present, few controls are used  in petroleum  solvent
plants to prevent solvent loss.  Four methods are  considered
technologically  feasible: 1) good housekeeping, 2) carbon  adsorp-
                              475
-------
tion, 3) incineration, and 4) waste solvent treatment.  The use
of condensation/refrigeration systems has been suggested.  Prob-
lems with the application of condensation systems include the
high stream volume from the dryer (4.7-7.1 m3/sec or 10,000-
15,000 cfm)8 required to keep the solvent below 257, of the lower
explosive limit, the risk of explosion from the condensate, and
the low temperature required.

          Good housekeeping is the simplest approach to controlling
solvent losses and is the only method practiced by the industry
today.  Fugitive emissions occur at valves, flanges, seals, covers
on storage tanks, and other sources.  Good housekeeping requires
no extra equipment and little additional maintenance effort.  It
has been shown that good housekeeping can reduce total emissions
in a transfer machine-type operation from 23 to 15.5 kg solvent/
100 kg materials cleaned (468 to 310 Ibs solvent/ton materials
cleaned).9

          A carbon adsorption system has been developed for re-
covering petroleum solvent vapors from dryer streams.  There are
several inherent problems in applying carbon adsorption.  First,
the bed capacity of the activated carbon for the solvent is low
(6%).  The adsorber bed must be rather large because dryer streams
are high volume and very dilute.  In addition, the hot exhaust
gases must be cooled  from 78 to 38°C (172 to 100°F) before adsorp-
tion will take place.10  Also, since petroleum solvents are highly
combustible, carbon chambers are potential fire hazards.

          Despite these drawbacks, carbon adsorption can be used
to efficiently curb emissions.  Carbon adsorption is employed at
three petroleum solvent-based dry cleaning plants in Derby, Eng-
land.  The units were designed to reduce inlet concentrations by
                               476
-------
9570.11  A prototype model of an adsorber that was 95 percent
efficient was introduced in the U.S. in 1973, but no market was
found for the capital intensive units.12  In May 1977, one ven-
dor had installed an adsorber on a petroleum dryer in an indus-
trial dry cleaning plant.  While the. unit did not perform at ex-
pected levels during tests conducted in June 1977, mass effi-
ciency was as high as 75-8070 on some closely monitored cycles.13

          Incineration is the third method of reducing dryer
emissions.  The dryer stream is vented to a large incinerator
where the petroleum vapors are burned.  There are disadvantages
to the system...  The high..volume of the dryer stream usually .pre-
cludes the use of the plant boiler for incineration, so additional
fuel is required.  However, because there is a high steam demand
in industrial plants, waste heat can be recovered in a steam
boiler.  Incineration is estimated to be 9870 efficient as an,
emission control method  and may reduce outlet concentrations to
20-30 ppm.lu

          Solvent retained in filter muck can be recovered by
vacuum distillation or centrifugal separation1.  Both methods can
reduce process -solvent losses-due to filter muck retention from
5 to 1 kg solvent/100 kg materials cleaned.15  Instead of on-site
recovery of waste solvent from the filter muck, solvent can be
disposed of by incineration.  Incineration is practiced at some
industrial plants.  Off-site solvent recovery by an independent
contractor is sometimes  practiced and cartridge filtration can
be employed to reduce emissions.

          With the use of this technology, emissions from petro-
leum solvent-based dry cleaning facilities can be greatly re-
duced.  The addition of  a carbon adsorption unit or incineration
                              477
-------
system and a waste solvent recovery scheme to a well maintained
plant can potentially lower its emissions to a level of 4-6 kg
solvent/100 kg materials cleaned.16  The technology for applica-
tion of these systems is currently available.

4.17.1.3  Cost, Energy, and Environmental Impact of Controls

          Costs for good housekeeping are negligible.17  Estimates
of capital and annualized costs for other control techniques are
presented in Table 4.17-2.  Data are presented for four sizes of
model plants.  Costs for actual installations may vary considerably,
Credits for solvent recovery are low because of the low cost of
petroleum solvents.  As the costs of petroleum solvents rise,
however, recovery techniques will become more economically attrac-
tive .

          Estimates of the energy impact from the use of carbon
adsorbers and incinerators are presented in Table 4.17-3.  Data
are provided for typical commercial and industrial plants.  Carbon
adsorbers consume fuel to produce steam for desorption, while
incinerators consume supplementary fuel to support conbustion.

          Solvent recovered by carbon adsorbers is recycled.  The
volume of solvent recovered in &.. industrial plant is approxi-
mately three times the volume of fuel consumed.23  Assuming that
at least one kilogram  (pound) of fuel is required to produce one
kilogram  (pound) of solvent, solvent recovery can be expressed  as
an indirect energy credit.  As shown in Table 4.17-3, use of car-
bon adsorbers results  in a net gain in energy for both commercial
and industrial applications.
                              478
-------
    TABLE 4.17-2.
ESTIMATES OF  CAPITAL AND ANNUALIZED COSTS OF VOLATILE ORGANIC
EMISSION, CONTROLS FOR  MODEL PETROLEUM  SOLVENT DRY CLEANING
PLANTS3.b'c'18'I*, 2°,2i
Dryer Emission Controls
' • ' Incineration
• with Heat
Carbon Adsorption Recovery








a
b
c
d
Type of Plant Washer Capacity
Commercial 27kg (60 11.) /loud

54fca. (120 lb)/load

Industrial 136kg (300 lb)/load

227kg (500 lb)/load

Fourth quarter 1976 coats expressed In thou
Capital costs Include design, purchase, and
Annual Ized costs Include labor, Maintenance
overhead, property taxes, and Insurance.
facility Capital Annual Capital
NVu 14.4 2.9 40.fi
F.xtstlng 16.8 3.5 50.8
Hex .271.4 . 5.4 4».3
Existing 31.9 6.7 61.6
Hew fit. 2 1.8 84.1
Existing 71.2 4.4 105.1
Hew 91. 0 0.1 116.0
Kxlstlng 110.0 5.1 145.0
sands of dollars.
Installation. :

Annual
10.6
12.7
14.2 .
16.1
25.1
29.3
35.7
41.6


Incineration
without Heat
Re-cover;
Capital Annual
24.0 10.5
30.0 11.7
28.) 16.0
J5.6 17,5
40.5 2».l
50.6 31.2
51. B 4J.5
44.7 45.1

rjna the filters
Filter Mick bias ion Controls
Centrifugal Cartridge
Separator Filter"
Capital
4.4
5.0
4.4
5.0
4.7
5.2
4.7
5.2
and charges
Annual Capital Annual
0.9 2.4 1.0
1.0 2.5 1.0
0.7 2.8 1.4
0.8 2.9 1.6
-3.2*
-3.1*
-6.2*
-6.1*
for depreciation. Interest,
Negative sign Indicates that credits frot» advent recovery exceed operating co.ta and capital
-------
           Incinerators,  on the other hand,  have  adverse energy im-
pacts.  The  data provided in Table 4.17-3 assumes  no heat recovery.
With primary heat recovery, fuel consumption  and net energy use
can be reduced by one-half.2"  In industrial  plants that require
steam, the energy impact can be further reduced  by using a waste
heat boiler  for secondary heat recovery.

           Energy information for filter muck  emission controls is
unavailable.   Since the control techniques  recover solvent, at
least part of the energy requirements are compensated by the in-
direct credit from solvent recovery.

           S0x,  NOX, CO,  and particulate emissions  are produced
by combustion associated with carbon adsorbers and incinerators.
Assuming  the use of No.  2 fuel oil containing 0.2  percent sulfur,
the impact from the combustion of fuel to produce  steam for carbon
adsorbers is negligible.25  Estimates of SOX, NOX  and particulate
emissions from incinerators are listed in Table  4.17-4.  CO emis-
sions are highly variable, depending on the type of petroleum sol-
vents, incinerated.

    TABLE 4.17-4.  ESTIMATES OF EMISSIONS FROM INCINERATION
                    IN TYPICAL PETROLEUM SOLVENT  DRY CLEANING
                    PLANTS a»26
  Type of Plant          ^°x           N0x         Particulates
 	Mg/vr (tons/yr) Mg/vr (tons/vr)   Mg/vr (tons/yr)
  Commercial          0.28 (0.31)     0.78 (0.86)      0.15 (0.16)

  Industrial15         2.8  (3.1)      7.8  (8.6)       1.5  (1.6)
a
 Assumes that incineration is equivalent to steca boilers using No. 2 fuel oil.
 This application reduces volatile organic emissions by 100 Mg/yr (110 tons/yr)


                              480
-------
          TABLE  4.17-3.   ENERGY IMPACT ESTIMATES FOR DRYER EMISSION CONTROLS IN  TYPICAL
                           PETROLEUM SOLVENT DRY  CLEANING PLANTS 3>2Z


                                                  Energy Use        Energy Recovery              Net Use
    Type of Plant       Control  Technique     '    .     c     :              .:
                                   .            GJ/yr  (106 Btu/yr)  GJ/yr (106 Btu/yr)        GJ/yr (106 Btu/yr)


    Commercial          Carbon Adsorption8          28 (27)             316 (300)                -288 (-273)

                        Incineration0            16,000 to  32,000          0                  16,000 to 32,000

                                               (15,000 to  30,000)   .                        (15,000 to 30,000)

                                                  280 (270)           3160 (3000)              -2880 (-2730)b

.»>                      Incineration0          ;  16,000 to  32,600    .      0                  16,000 to 32,000
00
•-1                                             (15,000 to  30,000)                           (15,000 to 30,000)



   Based on data from a  perchoroethylene plant (including energy for a muck cooker) .
   Negative sign Indicates  that  energy recovery exceeds energy uae.
   No heat recovery.
Industrial          Carbon Adsorption*        280 (270)           3160  (3000)              -2880  (-2730)b
-------
           Carbon adsorption systems add  to  the plant's water re-
quirement  because of the need for steam  for desorption.  The
condensate,  containing a portion of desorbed solvent,  is added
to the wastewater stream.  Estimates  of  increased water require-
ments for  carbon adsorption systems in typical petroleum solvent
dry cleaning plants are listed in Table  4.17-5.   Also presented
are estimates of the quantities of solvent  disposed of in the
plant's wastewater.

  TABLE 4.17-5.   ESTIMATES OF INCREASED  WATER USE AND SOLVENT
                  DISPOSED OF IN WASTEWATER AS A RESULT OF
                  APPLYING CARBON ADSORPTION IN TYPICAL PETRO-
                  LEUM SOLVENT DRY CLEANING PLANTS*,27

                             Increased              Solvent Disposed of
   Type of  Plant               Water Useb               in Wastewaterc
	kg/yr (Ib/yr)	kg/yr (Ib/yr)
   Commercial                13,500 (29,700)               1.4 (3.0)
   Industrial               135,000 (297,000)             13.5 (29.7)

.Based on measurements for perchloroethylene dry cleaning plants.
 Includes requirements for a muck cooker.
 Assumes that  solvent content will be the same as for perchloroethylene
 plants (
-------
clothing, and slight corrosiveness.  In addition, perchloroethy-
lene has been indicated as a potential carcinogen.30  Perchloro-
ethylene plants with good solvent recovery techniques are eco-
nomically competitive with petroleum solvent based plants.

          Figure 4.17-2 is a simplified flow diagram for a
perchloroethylene dry cleaning operation.  The basic cleaning
steps are similar to those of a petroleum solvent plant.  Dirty
clothes  are washed in a single solvent bath and  solvent is ex-
tracted  by spinning.  The-washing  and extracting steps are
accomplished in the sane piece of  equipment.  The clothes are
then dried in a reclaiming type,dryer.  The dryer may be  sep- '
arate (transfer-machine) or-part of the washer'extractor  .(dry—
to-dry machine).

          The reclaiming dryer used for perchloroethylene plants
is different-from the dryer used in petroleum solvent.plants.
Evaporated solvent is removed from the exhaust gas  by condensa-
                                                        "*~?
tion on  a cooling coil.  This exhaust is returned to the  dryer
until the solvent concentration is too low to condense.   Fresh
air is then used to finish the drying cycle and  evaporate"the
remaining solvent.  This air is vented to the atmosphere.

          Most  plants have a muck  cooker by.economic necessity.
Most of  the solvent is  cooked from the filter muck, condensed,
and recycled....  The-cooked muck and remaining solvent  are  stored
for later disposal.  Solvent that  has been filtered must  be  dis-
tilled to remove soluble  impurities  (fats, oils, greases).   Dis-
tillation bottoms are also stored  for later disposal with the •  -
filter muck.31
                              433
-------
CO
                                                    SOLVENT
                                                      TO
                                                    STORAGE
             ROOM AIR-
                    FUGITIVE
                    SOLVENT
                    VAPORS
            SOLVENT
             FROM
            STORAGE
                DIRTY
               CLOTHES"
               CONDENSER/
               SEPARATOR
SOLVENT
VAPORS/
                            WASHER/
                           EXTRACTOR
                                             CLEAN.WET CLOTHES
                                USED
                                SOLVENT
1
VENT
STILL
BOTTOM
STORAGE
              FRESH AIR CYCLE
                                                           MUCK
                                                                                               RECOVERED SOLVENt
                                                                                                   TO STORAGE
                                                        CLEAN, DRY CLOTHES
	^. FINAL
       VENT
                                                                                    MUCK TO
                                                                                    DISPOSAL
                          STILL BOTTOMS
                           TO DISPOSAL
                    Figure 4.17-2.   Flow diagram for  a dry cleaning plant using
                                       perchloroethylene solvent.
-------
4.17.2.1  Emission Characteristics

          Emissions of perchloroethylene vary greatly due to
equipment differences and the type of solvent recovery method
used.  An uncontrolled commercial or industrial plant can lose
more than 22 kg solvent/100 kg (22 lb/100 Ib) materials cleaned.
Potentially 14 kg/100 kg (14 lb/100 Ib) of solvent could be lost
in the filter rauck and 3-6 kg/100 kg (3-6 lb/100 Ib) in the dryer
stream, assuming a condenser is used before venting.32  Due to
economic considerations, most plants possess a regenerative fil-
ter system and a muck cooker that can reduce losses in that .area
to only 1-1.5 kg/100 kg (1-1.5 lb/100 Ib), for a plant total of--
8.1 kg/100 kg (8.1 lb/100 Ib).  Plants that use a carbon adsorp-
tion system on dryer exhausts can reduce losses by another 40%
to 4.0 kg/100 kg (4 lb/100 Ib).33'3"  An industry survey35 esti-
mates the average emissions of both controlled and uncontrolled
commercial and industrial plants to be 10-12 kg solvent/100 kg
(10-12 lb/100 Ib) materials cleaned.  Coin-operated systems
usually emit twice that amount.

4.17.2.2  Control, technology

          Economic incentives have brought about the use of
several different types of systems to curb solvent losses.  As
in petroleum based systems, the most important method of enis-
sion control is good housekeeping.  The competence of the oper-
ator is another important factor.  An IFI survey36 has recorded
differences in excess of 17.5 kg solvent/100 kg (17.5 lb/100 Ib)
materials cleaned for uncontrolled plants.  In another study37
emissions from plants employing carbon adsorption varied rrota
3.5 to 9.4 kg solvent/100 kg  (3.5 to 9.4 lb/100 Ib) materials.
cleaned.  These differences were due to housekeeping standards
and operator competency.
                              435
-------
          The best option for controlling solvent losses from
the dryer stream is carbon adsorption.  This method is used by
at least 33.57» of the industry.38  All perchloroethylene dryers
are of the recovery type; the dryer stream passes over water-
cooled condenser coils before venting.  Condensers recover 75%
of the solvent vapor, allowing 3-6 kg/100 kg (3-6 lb/100 Ib) to
escape.  The addition of a carbon adsorption unit can reduce sol-
vent losses to 0.3 kg solvent/100 kg  (0.3 lb/100 Ib) materials
cleaned with an average outlet concentration of 25 ppm or less.33'1*0

          Perchloroethylene retention in filter muck results in
a large potential solvent loss.  Economic incentives have brought
about virtually industrywide use of regenerative filters and muck
cookers.  Solvent is "cooked" out of the used filter materials
and is then steam distilled.  This process reduces emissions to
1-1.5 kg/100 kg (1-1?5 lb/100 Ib).*1  With the use of cartridge
filters or longer distillation times,  emissions can be reduced
to 1.0 kg/100 kg (1 lb/100 lb)."2

          Incineration, a process suggested for petroleum exhaust
                    -*&
streams, is not practical for perchloroethylene systems.  Per-
chloroethylene is virtually nonflammable, and combustion forms
undesirable by-products such as hydrochloric acid  (HC1), chlorine
(Cl2), and phosgene  (COC12).  These by-products could be removed
by water scrubbing, but that would create an additional water
pollution control problem.

          The emission controls best  suited for perchloroethylene
dry cleaning operations are good housekeeping, carbon adsorption
filters on dryer exhaust streams, and the use of filter muck
cookers.  The combination of these three methods can reduce an
uncontrolled plant emission rate of 22 kg/100 kg  (22 lb/100 Ib)
to 4-6 kg/100 kg (4-6  lb/100 Ib) . **3   A summary of  emission  rates
and sources can be found in Table 4.17-1.
                                           •
                              486
-------
4.17.2.3  Cost,  Energy, and Environmental Impact of Controls

          Costs  for good housekeeping are negligible." "*  Estimates
of capital and annualized costs for carbon adsorption systems are
listed in Table  4.17-6.  Data are presented for five sizes of model
plants.  Costs for actual installations may vary significantly.
Specific costs for muck cookers and filters are unavailable.

          Perchloroethyleive is more valuable than petroleum sol-
vents.  As a result, there is a much greater economic incentive
to employ recovery techniques in perchloroethylene plants.  Table
4.17-6 shows that costs for carbon adsorption systems are exceeded.
by credits from solvent recovery in all but coin-operated facili-
ties.  As mentioned earlier, muck cookers and regenerative filters
are already-being used by most of the industry because of the  eco-
nomic  incentive of solvent recovery.

          Energy is required to produce steam for desorption of
carbon adsorbers and to provide heat for muck cookers.  Table
4.17-7 lists estimates of the energy impact from these controls
in typical .plants.. Recovered solvent provides an indirect energy
credit, by re'due'ing the .energy'requirements for the production  of
fresh  solvent.  (See Section 4.17.1.3 for a more detailed dis-
cussion.)  For all installations, the indirect credit  from sol-
vent recovery exceeds  energy consumption.

          The air pollutants generated by the combustion  of  fuel
to provide energy  for  the above control methods are  considered
negligible for all applications."9  Estimates of water requirements
for carbon adsorption  systems in perchloroethylene plants are
listed in Table 4.17-8.  The water  is required in the  form of
steam  for desorption.  A portion of the desorbed solvent  remains
with the condensate which becomes part of the plant's  wastewatar
stream.  Estimates of  the amount of solvent disposed of with the
wastewater are also shown in  Table  4.17-8.

                               487
-------
            TABLE 4.17-6.
ESTIMATES OF  CAPITAL  AND ANNUALIZED COSTS FOR  CARBON
ADSORBERS IN  MODEL PERCHLOROETHYLENE  DRY CLEANING
PLANTSa 23 kg/load (50 Ib/load)
oo • "
CO
Industrial 91 kg/load (200 Ib/load)
136 kg/load (300 Ib/load)
a
.Fourth quarter 1976 costs expressed in thousands of
Installation
New
Existing
New
Existing
New
Existing
New
Existing
New
Existing
dollars.
Capital Cost
6.1
7.3
2.2
2.9
3.3
4.1
6.1
7.5
7.0
9.0

Annual ized
Cost
1.5
1.8
-o.id
0.1
-0.7d
-0.6d
-9.8d
-9.4d
-15.3d
-14. 8d

CAnnualized costs include labor, maintenance, utilities, credits for solvent recovery, costs for
.waste  disposal, and charges for depreciation, interest, overhead, property taxes, and insurance.
 Negative sign indicates that credits  from solvent recovery exceed operating costs and capital charges,
-------
              TABLE 4.17-7.   ENERGY IMPACT  ESTIMATES FOR CARBON  ADSORBERS AND
                              MUCK COOKERS IN TYPICAL PERCHLOROETHYLENE DRY
                              CLEANING PLANTS HB
Type of Plant
Coin-op
Commercial
Industrial
Energy Use
GJ/yr (106 Btu/yr)
7.0 (6.6)
28 (27)
280 (270)
Energy Recovery
GJ/yr (106 Btu/yr)
26 (25)
45 (43)
450 (430)
Net Use
GJ/yr (10s Btu/yr)
-20 (-19)3
-17 (-16) a
-170 (-160)3
a                  •      •
 Negative sign indicates that energy recovery exceeds  energy use.
-------
  TABLE 4.17-8.  ESTIMATES  OF  INCREASED WATER USE AND SOLVENT
                 DISPOSED OF IN WASTEWATER AS A RESULT OF APPLY-
                 ING  CARBON ADSORPTION IN TYPICAL PERCHLORO-
                 ETHYLENE DRY  CLEANING PLANTS50
Type of Plant
Coin-op
Commercial
Industrial
Increased
Water Use3
kg/yr (Ib/yr)
1,600 (3,500)
13,500 (29,700)
135,000 (297,000)
Solvent Disposed
in Wastewater
kg/yr (Ib/yr)
0.2 (0.4)
1.4 (3.0)
.13.5 (29.7)
a
.Includes requirements for a muck cooker.
 Based on measurements of solvent concentrations 
-------
 its  use  in  some  applications  and make  efficient  solvent  recovery
 a necessity.

          The  fluorocarbon  based system utilizes only  the  dry-
 to-dry type of machine where  washing and drying  are  performed in
 the  same machine.  All have built-in control  devices.   Solvent
 is filtered through  cartridge filters  and distilled  before it is
 recycled.   The filters can  then be  dried in the  drum before dis-
 posal.

          The  machine is  completely closed to the atmosphere
 during operation.  This means...there .is no exhaust gas  stream
 from the dryer.   Figure 4.17—3 shows.the air  flow pattern  for-
 a typical fluorocarbon drying circuit.  Expansion and  contraction
 of the air  stream is accounted for  by  an elastomeric "lung" not
 pictured.53

 4.17.3.1 Emission Characteristics

          Average solvent losses are unknown.  In tests  conducted
 by EPA and  one solvent manufacturer, emissions were  usualiy less
 than 5 kg/100  kg (5  lb/100  Ib)  materials cleaned.51*  Losses can.
 be attributed.to solvent  retention  in  filter  media,  leaks  from
 pumps, valves, and gaskets, and certain fixed losses.   Solvent
..-losses in the  filter media  amount to 1 kg solvent/100  kg (1 Ib/
 100  Ib)  materials cleaned.   Leaks from pumps, valves,  and  gaskets
 contribute  1-2 kg solvent/100 kg  (1-2  lb/100  Ib) materials cleaned.
 Fixed losses include solvent  retained  by clothes (minimal) and
 solvent  vapor  lost from  the cleaning wheel when  the  door is
 opened between loads.5 5
                               491
-------
to
       WASHER/DRYER

           DRUM
              AIR AND
              EVAPORATED
              SOLVENT
HOT AIR
                              BLOWER
                           AIR HEATER
          REFRIGERATED
           CONDENSER
                                                                       DRY AIR
                                                            SOLVENT TO
                                                           •RECYCLE AND
                                                             STORAGE
       Figure 4.17-3.  Flow diagram for dry cleaning plant using  fluorocarbon solvent,
-------
4.17.3.2  Control Technology

          Emission control in fluorocarbon based operations is
achieved by the use of refrigeration/condensation systems and by
good housekeeping.  Dryer streams are never exhausted.  Instead,
they are recirculated over refrigerated coils to condense the
solvent at temperatures of -18°C (-0.4°F).  Refrigeration/
condensation can achieve 907. solvent recovery.56  Reduction of
solvent vapor concentration to 77* is routinely achieved to curb
solvent loss.   Good housekeeping practices serve to maintain
high solvent recovery.

          The only other major loss of the fluorocarbon is by
filter media retention.  If the cartridge filter is dried- in the
unit after use, emissions of 0.5 kg/100 kg (0.5 lb/100 Ib) or  less
can be achieved.57  A summary of emission rates and sotir_ces can- be
found in Table 4.17-1.

          Other control methods are not applicable to fluorocarbon
systems.  Carbon adsorption filters have been marketed,-^33^ the
units did not function well in this application.  Incineration
cannot be used because the fluorocarbon is nonflammable and
combustion produces halogenated by-products .

4.17.. 3.3  Cost, Energy, and Environmental Impact of Controls

          .Because of  the high cost of fluorocarbon solvents,
controls for emissions O'f volatile organics  are already built
into all units.  There are no additional  cost, energy, or en-
vironmental impacts.
                              493
-------
  4.17.4    References

  1;   U.S.  Environmental  Protection Agency.   Control  of Volatile
      Organic Emissions  from Dry Cleaning Operations.   Research
      Triangle Park,  N.C.   April 15, 1977.

  2.   Reference 1,  Chapter 3.

  3.   Kleeberg, C.  F.,  Environmental Protection Agency.  Informa-
      tion from telephone conversation with James Schmidheiser,
      DuPont sales  representative.   May 24,  1976.

  4.   U.S.  Department of Commerce,  Bureau of the Census, 1972
      Census of Business,  Selected Service Industries,  Area
      Statistics,  by State.

  5.   Environmental Protection Agency.  Information submitted by
      dry cleaning industry representatives.  Durham, N.C.  De-
      cember 14, 1976.

  6.   McCoy, B. C.   Study to Support New Source Performance
      Standards for the Dry Cleaning Industry, Final Report.
      U.S.  Environmental Protection Agency.   Research Triangle
      Park, N.C.  May 1976.  118 p.

7-8.   Reference 1.

  9.   Reference 6.

 10.   Letter from Vic Manufacturing Company, Minneapolis, Minne-
      sota, to San Diego Branch of Naval Facilities Engineering
      Command, San Diego, California.  June 21, 1977.
                                494
-------
   11.   Kleeberg,  C.  F.,  Environmental Protection Agency.   Informa-
        tion from  telephone  conversation with Michael Worrall,
        Manager, Solvent  Recovery Division,  American CECA.   July 9,
        1976.

   12.   Reference  6,

   13.   Scott Environmental  Technology,  "Evaluation of Hydrocarbon
        Emissions  from a  Dry Cleaning Plant," November, 1977,

   147   Kleeberg,  C.  F.   Environmental Protection Agency.   Informa-
        tion from  telephone  conversation -with J.  Jackson,  Combus-
        tion Engineering, Inc.   June 15, 1976. -   -

  .15'."  Kleeberg,  C.  F. ,  Performance of a Centrifugal.'Separator in
       'Service at a Petroleum Dry Cleaner,  memorandum to James
        Durham (EPA), August 25,  1977.

   16.   Reference  6.

17-18.   Reference  1,                                             •

   19.   Data courtesy of Mr. J. K. Clement,  President, Bock Laundry
        Machine Company and Mr. Creek, Installer, Bock Laundry Ma-
        chine Company.  As cited in Reference 1.

   ,20.  , Personal communications with Mr. R.  D. Whiffing, Sales Repre-
        sentative, Interdyne, Inc., and Mr.  Barber of VIC Manufac-
        turing Co.  As cited in Reference 1.

   21.   Cost data and equipment brochures furnished by Mr. J. L.
        Cunniff, President Puritan Division,  R. R. Street &  Company,
        tn-c. ' 'As cited In Reference 1.
                                 495
-------
   22.   Reference 1.

   23.   Reference 6.

24-28.   Reference 1.

   29.   Reference 5.

   30.   National Cancer Institute.  Bioassay of Tetrachloroethylene
        for Possible Carcinogenicity.   Draft Report.  March 16, 1977,

   31.   Reference 6.

   32.   Fisher, W. E.  The ABC's of Solvent Mileage, Part I.  IFI
        Special Reporter.  No. 3-4.  July-August 1975.  As cited
        in Reference 1.

   33.   Anonymous Dow Chemical Survey Submitted by Joseph Cunniff,
        Puritan Filters, to EPA on March 3, 1977.  As cited in
        Reference 1.

   34.  Reference 32.

   35.  Watt,  Andrew IV, and  W. E.  Fisher.  Results  of Membership
        Survey of Dry  Cleaning  Operations.  IFI  Special  Reporter.
        No.  3-1, January-February,  1975.  As  cited  in Reference 1.

   36.  Reference 32.

   37.  Reference 6.

   38.  Mayberry, J. L.  President, R.  R.  Streets & Co.,  Inc.,
        letter to John H,  Haines,  EPA,  March  2,  1977. As cited
        in  Reference 1.

                                 .496
-------
   39.  "Air Pollution Emission Test, Texas Industrial Services"
        report prepared by Midwest Research Institute, EPA Contract
        No, 68-02-1403, Task 21, June 25, 1976.

   40.  "Air Pollution Emission Test, Hershey Drycleaners and Laundry,"
        report prepared by Scott Environmental Technology, EPA Con-
        tract No. 68-02-1400, Task 21, March 1976.

   41.  Reference 32.

 "-42'.  "-IFI Special Reporter," No. 3-4, International Fabricate•••'
    •  .-Institute, "Jbliet, Illinois,,, July-August/1975.

   431;..,, Reference 6-.

44-45.  Reference 1.

   46.  Cost data and equipment brochures furnished by Mrs. Pat
        King, Executive Assistant, HOYT Manufacturing Corporation,
        and Mr. Peter Zlzzi, Sales and Service Engineer, Fulton
        Boiler Works, Incorporated.  As cited in  Reference 1.

   47.  Information furnished by Mr. A. C. Cullins, Laundry and
        Drycleanitig Consultant,, Standard Laundry  Machine Company,
        Inc.  As cited in Reference 1,

48-51.  Reference 1.

   52.  Reference 5.

53-54.  Reference -6.

   55.  Reference 3.
                                  497
-------
56.  Reference 1.





57.  Reference 6,
                               498
-------
4.18      Fiber Production

          This section describes organic emissions from the
production of natural and synthetic fibers.  Fiber production
is one of the steps in textile manufacturing.  Other textile
processing steps such as texturizing, dyeing, and carpet manu-
facture may also emit organics, but are not covered
in this section.

          The three classes of fibers are synthetic fibers,  ••-"  .
cellulose derived (semi-synthetic) fibers, and natural fibers.  *".'.•;
Synthetic fibers such as nylon and polyester are spun from
polymers synthesized from organic chemicals.  Acetate, rayon.,-  ••"".•
and other cellulose-derived fibers are manufactured by chemi-
cal recovery of cellulose from a natural source such as wood    ••••""
or cotton.  Natural fibers such as wool and cotton are produced
by mechanical processing steps rather than chemical synthesis.

          Organic emissions and control technology for man-made
synthetic and cellulose-derived fibers are discussed in  Section
4.18,1.  Section 4.18.2 discusses natural fibers,

4.18.1    Man-Made Fibers

          Man-made fibers  include synthetic  fibers  (Section 4.18.
1.1)  and semi-synthetic cellulose-derived fibers  (Section 4.18.1.2)

4.18.1.1  Synthetic Fibers

          Some  22 Tg  (48,400  x 106  Ibs) of polymer are produced
annually.  Roughly 19% of  polymer production is used to  produce
synthetic fibers-.1  Table  4.18.1  lists the most important synthe-
tic  fibers,  their uses, constituents,  and  spinning processes.
                               499
-------
                           TABLE 4.18-1.   SYNTHETIC  FIBERS:   PRODUCTION,  USES,
                                    CONSTITUENTS,  AND  SPINNING PROCESSES2-3
           Fiber
           Class
1975 Production
 Gg (106  Ibs)
Uses
Constituents
Spinning
Process
o
o
        Polyester      1360 (2995)     Apparel,  carpet,  tire cord,
                                      fiberfill
        Nylon           843 (1857)     Textiles,  apparel, carpet,
                                      industrial applications
        Acrylic &       238  (525)     Wool-like fibers for apparel
        Modacrylic                     and home furnishings
        Polyolefin      226  (497)     Carpets,  industrial twines,
                                      some apparel

        Other             5   (11)     Various uses
                                                Dimethyl terephthalate or      Melt
                                                terephthalic acid and
                                                ethylene glycol, catalyst

                                                Nylon 6:  carpolactam.         Melt
                                                Nylon 66:  adipic acid
                                                and hexainethlyene diamene

                                                Acrylonitrile; aerylate        Wet, Dry
                                                monomers (acrylic) or vinyl
                                                monomers (modacrylic);
                                                additives

                                                Polyethylene or poly-          Melt
                                                propylene, additives

                                                Spandex, vinyon, saran,        Varied
                                                fluorocarbons
-------
          Synthetic fibers are  spun from melted  or  dissolved
polymer chips.  The three major spinning processes  employed are
melt, dry, and wet spinning.  The-process  used for  a  particular
polymer depends on its melting  point, melt stability,  and solu-
bility in organic solvents.*  Figure  4.18-1 is a flow diagram
for the three spinning processes.

          Melt Spinning

          Melt spinning  is generally  used  to produce  polyester,
nylon, polyolefin, and saran  fibers.  Resins used in  this process
must be stable at high temperatures to  prevent decomposition.  ......
Polymer chips are melted in a heated  screw extruder,  processed...
.in'a nitrogen-•atmosphere, theft'"-filtered through  a series df tne'tal
•'gauzes or a-Layer of  graded saiid.  The  molten polymer is extruded
under pressure .and at a  constant rate through spinnerets.  Ex- -
trusion is followed by air cooling.   The fibers  may""be steam con-
ditioned before merging  into  a  "spun" yarn.5

          Wet Spinning   -'     -       •	•

          Wet spinning is used  to  produce  acrylic,  modacrylic
and spandex  fibers.   In  the wet spinning process polymer chips
are dissolved in a solvent.  -The solution  is extruded through
spinnerets into a coagulating bath where the fibers are formed.
A  washing step is required after spinning  to remove traces of
solvent and  other impurities.   Both batch  and continuous washing
steps are employed,0  Table 4.18-2 lists typical solvents arid
coagulants used in wet spinning.                          .   .... •"'
                               5Q1
-------
       MOITEN
      POLYMER
or
O
to
                                                                         VENT
                                                                         OA»I»
VINT
lUKS
ORAWWQ
— -
rmtn
nooiricAncw
rwHHto
FIVER
                    Figure 4.18-1.  Flow  diagram for spinning operations
                                     used  in synthetic  fiber production
-------
          TABLE  4.18-2.  INPUT MATERIALS FOR WET SPINNING7
 Fiber
Polymer
    Solvent
Coagulant
 Acrylic    Polyacrylonitrile
 Modacrylic Polyaczylonltril*-
           poly(vinyl
           copolymer
 Spandex    Polyurethane
              Dinethyl«cetamide  Aqueous DMAc
              (DMAc)
Aqueous ZnCl2
Aqueous NaSCN
Acetonitrile
Acetone
                               Aqueous ZnCl2
                               Aqueous NaSCN
                               Aqueous Acetonitrile
                               Water
              Diraethylformaraide  Water
              (BMF)
          Like  wet spinning,  dry spinning uses a  solvent to
dissolve the  polymer chips.   The solution is extruded into a
chamber of heated gas or vapor.   The solvent evaporates and a
fiber is formed.   Because the process utilizes high spinning
speeds, it can  be used to produce continuous filament yam.*
Table 4.18-3  lists solvents and polymers used in  this process

        TABLE-4.18-3.  INPUT  MATERIALS FOR DRY SPINNING9
 Fiber
      Polyraer
                     Solvent
 Acrylic

 Modacrylic

 Spandex
Polyacrylonitrile

Polyacrylonitrile/
poly(vinyl  chloride)
Polyurethane
             DKF,  DMAc
             tetramethylene sulfone
             Acetone
             DMF,  BHAc
                                503
-------
          Finishing

          Fibers must be finished before being woven into a fabric.
The first step usually is lubrication to prevent static .electri-
city build-up and to protect machinery.  Next, the fibers undergo
"drawing", a process in which the fibers are stretched, sometimes
under heat, to introduce molecular orientation and increase
strength.

          Finally, the fibers may undergo some form of physical
modification to produce a specified product.  This may be as
simple as cutting continuous filament into short lengths called
staple, or as complicated as false-twist texturing, crimping,
heat setting, and heat relaxation.  These processes involve
heating the fiber close to its melting point, then stretching,
folding, twisting or relaxing.

4.18.1.2  Semi-Synthetic Fibers

          Rayon and acetate are considered semi-synthetic because
both are cellulose derived.  Rayon is the oldest man-made fiber
and is produced from dissolved wood pulp or cotton linters.  Three
processes are used to regenerate the cellulose; viscose, cupram-
monium, and the nitrocellulose process.  In each case, 'the cellu-
lose is regenerated by a chemical reaction, extruded, and then
spun into yarn.

          Acetate was the second man-made fiber to come into
general use.  It is also derived from wood pulp or cotton linters,
but the cellulose is acetylated by treatment with acetic and sul-
furic acids.l°
                              504
-------
4,18.1.3  Emissionsand  Control  Technology

          Emissions from man-made  fiber production include sol-
vents, coagulants, additives,  and  other organic compounds used
in processing.   Sources  include  the  heating and cooling processes
in melt spinning and  solvent vapor losses  in wet and dry spinning.

          .Solvent loss.es.-may..also  occur during finishing pro-
fesses when  the  fiber-is heated  to trear its melting point.  Vola-'
tile  organics present 'in the-polymer--are vaporized under 'these
conditions1.'  •• Solvent  lt3"Sses""also occur in  rayon -an-d acetate pro-
duction.  One source  reports that,0.28. kg  acetone/kg product
 (0.28 Ib/lb) is  lost  in  acetate  production.11

          Emission rates depend  on the type of solvents and raw
materials used,  the temperature  of the product, and use of sol-
vent  recovery or emission  control, techniques.  Table 4.18-4 lists
organic emissions from man-made  fiber  production for 1975.  Emis-
sions for 'other • fibers' not listed  are  probably similar to those
encountered  in  the original resin  production.12

 .  .TABLE' 4.18-4.   EMISSIONS FROM MAN-MADE  FIBER PRODUCTION13
Product
Nylon 66
Cellulose Acetate : .
Nylon 6
Viscose Rayon
Modacrylic Fibers
Polyurethane Fibers
Volatile Organic Emissions
Msz/vr •
2900.0
1900.0
1400
1200
320
4.1
(10" Ibs/vr)
630
410
290
270
70
0.9
                                505
-------
          Applicable control methods are the same as those used
in the polymer industry:  carbon adsorption, resin adsorption,
incineration, solvent absorption, refrigeration/condensation,
vacuum stripping, and good housekeeping.  These control tech-
niques are discussed in Section 3.0.  Solvent recovery, used in
both wet and dry spinning processes, is another important means
for reducing emissions.11*  Controls are generally not used in
rayon production, but an activated carbon adsorption system
could reduce emissions 80 to 95 percent.15

4.18.2    Natural Fibers

          Natural fibers such as cotton and wool undergo numerous
mechanical and inorganic chemical treatments to produce woven ma-
terial for marketing.  Of these processes, only scouring emits
volatile organics.

          Scouring is performed several different times in cotton
and wool processing.  It is the process by which applied, acquired,
and natural  impurities are removed.  Applied impurities are  sub-
stances  (identification paints;, insecticidesi- or bacteriocides)
that have been added to the raw fibers by man.  Acquired impur-
ities include dirt, dust, straw, and vegetable matter. ' "Natural
impurities include glandular secretions of'  animal origin  (yolk)
in wool  and  natural waxes, oils and pectins in cotton.

          Scouring is done with either detergents or organic sol-
vents (benzene,  CC1«», ethyl alcohol, methyl alcohol, isopropyl
alcohol).  After solvent scouring, the  cloth must be rinsed  (or
washed again) to remove water soluble materials and residual sol-
vent . L 6

          Volatile organic emissions from fabric scouring were
estimated to be  22.7 Gg  (50 x 106  Ibs)  in 1975.17  Applicable

                               506
-------
  control techniques are incineration and,  for solvent  systems,
  efficient handling and recovery techniques.   These control tech-
  niques are discussed in Section 3.0.   Waste  solvent disposal is
  discussed in Section 4.15.

  4.18.3    References

  1.   Shumaker, J.  L.  Polymer Industry Study.   Internal EPA report
      to D. R. Patrick, Chief,  Chemical Manufacturing Section.
      May 10, 1977.

  2.   C&EN's Top 50 Chemical  Products and Producers.  Chemical
      and Engineering News,  54(19):33-39, May  3,  1976.

  3.   Production Fell, Often  Sharply, Last Year for Almost all
      Major Chemical Products.   Chemical and Engineering .News , •••
      54(24):35, June 7, 1976.

4-9.   Parr, J.  The Synthetic Fiber Industry In:   Industrial Pro-
      cess Profiles for"Environmental Use.  Chapter 10.  Indus-
      trial Environmental Research Laboratory, Office of Research
      and Development, U.S.  Environmental Protection Agency.
      Cincinnati, Ohio.. EPA-600/2-77.-023k.  February 1977.  55p.

 10.   1975 Man-made Fiber Deskbook.  Modem Textiles.  17-20,
      March 1975.

 11.   Riley, J. L. Fiber Manufacturing Processes.   In:  Man-made
      Textile Encyclopedia.   Press, J. J.  (ed).  New York,  Textile
      Book Publishers,  Inc.   1959.  p. 50-52.

 12.   Reference 1.

 13.   Overview Matrix.  Monsanto Research Corporation.  Dayton,
      Ohio.  Contract Number 68-02-1874.  July 1975.
                                 507
-------
14.   Reference 4.

15.   Fluidized Recovery System Nabs Carbon Bisulfide.  Chem.
     Eng. 7C)(8) :  92-94, April 15, 1963.  As cited in Environ-
     mental Protection Agency, Compilation of Air Pollution
     Emission Factors.  Second Edition with Supplements.  Office
     of Air Quality Planning and Standards.  Research Triangle
     Park, North Carolina.  Publication Number AP-42.  February
     1976.  462 p.

16.   Lund, H. F.   Industrial Pollution Control Handbook.  New
     York, McGraw Hill, 1971.

17.   Reference 13.
                                508
-------
4.19      Degreasing and Waste Solvent Disposal

          Degreasing or solvent metal cleaning employs non-
aqueous solvents to remove soils from the surface of metal
articles which are to be electroplated, painted, repaired, in-
spected, assembled, or further machined.  Metal workpieces are
cleaned with organic solvents because water or detergent solu-
tions exhibit a slow drying rate, electrical conductivity, high
surface tension, a tendency to cause rusting, and a relatively
low solubility for organic soils such as greases.  A broad
spectrum of organic solvents is available, such as petroleum
distillates., chlorinated hydrocarbons., ketones, and alcohol's:"  ..
-Although solvents may vary, there are basically three types of;
degreasers:  cold cleaners, open top vapor degreasers, and
conveyorized degreasers.               .

          Descriptions for the three degreasing processes are
given in Section 4.19.1-  Emission characteristics are discussed
in Section 4.19.2 and control technology is described in Section
4.19.3.

4.19.1    Process Descriptions

4.19.1.1  Cold Cleaners

          Cold cleaners are the simplest, least expensive, and
most common type of degreaser.  They are used for the removal of
oil base Impurities from metal parts in a batch-load  procedure
that can include spraying, brushing, flushing, and immersion.
The cleaning solvent is generally at room temperature.  Although
it may be heated slightly, the solvent never reaches  its boiling
point.  When., parts are soaked to facilitate cleaning, it is not
uncommon for the solvent to be agitated by pumps, compressed air;
mechanical motion, or sound.

                               509
-------
          There are several methods for materials handling in
cold cleaning operations.  Manual loading is used for simple,
small-scale cleaning operations.  Batch loaded conveyorized
systems are more efficient for complex, large scale operations.
Loading systems can be set to automatically lower, pause, and
raise a work load.  By dipping in a series of tanks, each with
increasingly pure solvent or possibly a different solvent, a
"cascade" cleaning system is established.

4.19.1.2  Open Top Vapor Degreasers

          The open top vapor degreaser cleans by condensing va-
porized solvent on the surface of the metal parts.  The soiled
parts are batch loaded into the solvent vapor zone of the
unit.  Solvent vapors condense on the cooler surface of the
metal parts until the temperature of the metal approaches the
boiling point of the solvent.  The condensing solvent dissolves
oil and grease, washing the parts as it drips down into the tank.
Sometimes the cleaning process is modified with spraying or dip-
ping.

          To condenae rising vapors and prevent solvent 'loss,
the air layer or freeboard above the vapor zone is cooled by a
series of condensing coils which ring the internal wall of the
unit.  Most vapor degreasers also have an external water jacket
which cools the freeboard to prevent convection up hot degreaser
walls,  The freeboard protects the solvent vapor zone from dis-
turbance caused by air movement around the equipment.

4.19.1.3  Conveyorized Degreasers

          Conveyorized degreasers operate on the same principles
as open top degreasers; the only difference is in materials
                               510
-------
handling.  In conveyorized cleaners, parts may be dipped but
manual handling is mostly eliminated.  In addition, conveyorized
degreasers are almost always hooded or covered.

          There are many designs for conveyorized degreasers.
These include monorail, cross-rod, vibra, ferris wheel, belt,
and strip degreasers.  Each conveying operation can be used with
either cold or vaporized solvent.  The first four designs listed
above usually employ vaporized solvent.  Conveyorized degreasers
are used in a wide range of applications and are typically found
in plants where there is enough production to provide a continu-
ous stream of products to be degreased.

4.19.2    Emission Characteristics

          Solvent consumption..statistics indicate that total
national degreasing emissions are about  680 Mg/yr.  The actual
breakdown o-f sources is shown in Table 4.19-1.  Although a cold
cleaner has the lowest emission rate, there are many units  in
operation.  As a  result, cold cleaners are the primary contribu-
tor of solvent emissions from metal  cleaning operations.
Emissions occur due  to evaporation  from  the solvent bath,
solvent  carry-out, agitation, waste  solvent evaporation, and
exhaust.

          Solvent emissions resulting from bath evaporation in-
clude diffusion and  convection losses.   These  losses are in-
creased  through failure to  close  the cover whenever parts are
not being handled.  Open top vapor  degreasers  and  conveyorized
degreasers have a vapor/air interface at the  top of the vapor
zone.  Here, evaporated solvent mixes with the air as  a result
of diffusion, drafts,  and. turbulence from parts being  inserted
and removed.  Warm solvent-laden  air is  carried upward bv convec-
tion, and the solvent  vapors diffuse into the  room.  Esciraates  for
                               511
-------
    TABLE 4.19-1.  TYPICAL EMISSIONS  FROM ORGANIC SOLVENT METAL CLEANING OPERATIONS'


Wt
G


Type of Degreaser
Cold Cleaner
Open Top Vapor
Degreaser
Conveyorized Degreaser
*450
-(25) for wiping losses
-(25) for eonveyorized cold
Approximate Estimated
Mo. of Units _
In use |a
1,220,000 . 380*
21,000 200
3,700 100


cleaning. ,
National Emission
tqna
y*
(420,000)
(220,000)
(110,000)



Average Emission late/ Unit
Mg tons
yr yr
0.3 (0.33)
10 (11.0)
27 (30)



-(20) for non-evaporative waste solvent disposal
380
-------
solvent diffusion emissions are 0.24 kg/hr-m2  (0.05 I
if no appreciable drafts cross the top of the  tank.2  Con-
veyorized degreasers are normally enclosed, so convection and
diffusion losses are minimized.

          Carry-out emissions result from entrainment of liquid
and vaporous solvent as clean parts are removed from the de-
greaser.  This problem can be complicated by the shape of the
part.  Crevices and cupped portions may hold solvent even after
the part appears to be dry.  Carry-out emissions are usually
the major emission from conveyorized degreasers because of  the
inherently large work load.                                   '   ..

                             '  "" •              .        f   •"-"[''.
          Agitation of solvent in cold cleaners increases etuis'-•'•-
•slons--.  The extent., of this increase depends on" the-use of a .. ....
cover, the type of- • agi tation-, and' adjustments  to tne, -agitation."
system.  Emissions are normally""insignificant  if the cover  is
closed during agitation.  However, if the cover is  left open,
emissions from all types of agitation are significant.

          Solvent emissions due to spray evaporation are usually
only a problem in cold cleaners.  Increased emissions in open
top vapor degreasers are not a problem 'if sprays are kept below
the condensing .coil level,-- The--amount of emissions will depend
on the pressure and drop size of the spray, the volatility  of
the solvent, and the tendency to splash and overspray.  Common
practice is to keep the spray at a pressure less than 68.9  k?a
(10 psig) and in a solid,  fluid stream.

          Excessive exhaust emissions result when  exhaust rates
for open top vapor degreasers and conveyorized degreasers are
set too high.  Disruption  of the vapor/air interface can occur,
causing solvent vapors to  be carried out by rhe exhaust  system.
The average exhaust rate is 15 m3/min-m2  (50 f t3/*nin-f t2) of

                               513
-------
degreaser opening.3  However, this rate may be exceeded to com-
ply with OSHA regulations on worker exposure levels.   In any
case, there should be a cover that closes beneath the exhaust
intake vents to prevent withdrawal of solvent-laden vapor.

          Waste solvent evaporation is a source of emissions
from all degreasers, but the fraction of total emissions due to
waste solvent varies for each type.  Estimates are that approxi-
mately one third,  280 Gg/yr  (309,000 tons/yr), of the total
solvent emissions from degreasing operations  can be attributed
to waste solvent evaporation.  Estimated percentages are 45-70
percent for cold cleaners, 20-25 percent for  open top vapor de-
greasers, and 10-20 percent  for conveyorized  degreasers.4  The
amount of waste solvent evaporation is a function of the quantity
of waste solvent handled and the method of disposal.

          The breakdown in waste solvent disposal methods is
given in Table 4.19-2.  Not  all of these methods are ideal;
recommended methods include  reclamation, direct incineration,
and  chemical landfills.  Unacceptable disposal routes include
flushing down sewers, spreading on dirt roads for dust  control,
and  land-filling where evaporation or soil leaching can occur.
  TABLE 4.19-2.  CURRENT WASTE SOLVENT DISPOSAL METHODS5'1

                                         Percent of Waste
	  Disposal Method	Solvent Handled
1)  Dumping, open storage containers,
    municipal or chemical landfills,
    and deep well injection                     35
2)  With waste crankcase oil                    15
3)  Properly controlled incineration             5
4)  Reclamation                                 45
                               S14
-------
4.19.3    Control Technology

          There are several methods for controlling organic sol-
vent vapor emissions from degreasing operations.  In all instances,
emissions reduction can be accomplished through better equipment
design and improved operating practices.  For example, the emis-
sions from spray evaporation can almost be eliminated by careful
operation and a sensible, low pressure design.  Furthering this
example, designs can include internal spray chambers which com-
pletely eliminate emissions due to spraying.  In many cases, addi-
tional emissions reduction can lie achieved with add-on control
equipment.

          Solvent emissions resulting from diffusion and evapo-...
ration from the solvent bath can be reduced by using an improved'
cover, a higher freeboard, refrigerated chillers, carbon adsorp-
tion, incineration, or liquid absorption.  For vapor degreasers
the use of a cover, which operates- in a horizontal motion so that
the vapor/air interface is not disturbed, is  the single most..im-
portant control device.  These -covers can be  a roll type plas'tic
cover, canvas curtain, or guillotine cover.   It has been shown  ••
that covers reduce total emissions by approximately 20 to 40 per-
cent. s

          For open top vapor degreasers a higher freeboard would
provide greater protection of the vapor/air interface from out-
side disturbance.  .The freeboard ratio  (defined as freeboard
height divided by width of the air/solvent  area, i.e., F/W)  is
usually 0.5-0,75.  By increasing the freeboard  ratio  from 0.5  to
0.75 for an idle open top vapor degreaser,  emission reductions
of  25-30 percent are expected.  By increasing the freeboard
ratio from 0.5 to  1.0, the reductions may be  as high  as 50 per-
cent.9.  However, for open top vapor degreasers  with a normal
workload, the emission reductions may be  somewhat less.   Increas-'
ing the freeboard  height on  cold cleaners is  only effective  when
high volatility  solvents are used,
                               515
-------
          Refrigerated chillers are a second set of condenser
coils located slightly above the primary condenser coils of a
degreaser.  The purpose of refrigerated chillers is to create a
cold blanket of air immediately above the vapor zone which re-
duces the mixing of air and solvent vapors.   This can be done
by circulating a below freezing coolant, -23°C to -30°C (-10°F
to ~20°F), or an above freezing coolant, 1°C to 5°C (34°F to
40°F).   One variation on the refrigerated chiller .eliminates
the need for a second set of consenser coils.  Refrigerant is
circulated in the primary coils.  The refrigerant cooling rate
must be 100-120%, of the heat input rate to the boiling sump.10
Estimates are that refrigerated chillers will reduce emission
rates by approximately 40%.  Representative below freezing
units have achieved reductions of 43 to 62%.]1

          Carbon adsorption is a well proven technology for the
control of solvent emissions from degreasing operations, par-
ticularly for spray chambers where  the  area  must  be exhausted to
protect the operator.  Activated carbon has  a very good capacity
for commonly used solvents such as  trichloroethylene, per-
chloroethylene, and 1,1,1-trichloroethane.*2  Although carbon
adsorption units can remove 95-100% of  the organic input to the
bed, reductions in the total solvent emission are only 40-65%.
Some systems achieve less than 40%  emission  reduction because
of poor inlet collection efficiency and an improperly maintained
or adjusted carbon adsorber.13

          Liquid absorption is also a well-known method of
controlling organic emissions, but  has  design problems which
make it an  impractical alternative.  For example,  trichloro-
ethylene vapors are easily absorbed by  mineral  oil.   The ab-
sorption  column is operated at 30°C (86°F) and  the column  eff-
luent contains about  120 ppm mineral oil vapors.   In  essence,
                               516
-------
one emission problem is exchanged for another.  Chilling  the ab-
sorbing fluid would reduce the concentration of mineral'oil in.
the exhaust gas, but would also lead to ice formation within the
column and greatly increase the energy requirement.  Liquid ab-
sorption is practical only for the recovery of high concentra-
tions of solvent vapors, very valuable vapors, or toxic chemi-
cal vapors.

          Carry-out emissions can be appreciable if proper ma-
terials handling procedures are not followed.  Drainage facil-
ities are used  to control emissions from  cold cleaners  and dry-
ing tunnels and rotating baskets are used for conveyorised      ,- •
-cleaners.    .....

          Drainage facilities for cold cleaners consist of a--. •
rack" o"f basket  which is mounted internally or externally.  The '
liquid 'solvent-  drips from the parts into--a drainage trough
-which channels  it back into the solvent bath.  The  EPA recom-
mends an average draining time .of about  15 seconds.11*

          A drying tunnel is an..-extension of  sheet metal  from
the end of a conveyorized degreaser which allows the  cleaned
parts more time to dry.  Drying tunnels  are more effective when
used in ..conjunction with a.-carborv adsorber.   Rotating baskets
are perforated'-"cylinders which rotate  slowly  as  they  carry  the.
p-arts to be cleaned through the system.   The  slow  rotation
prevents liquid solvent from being  trapped in the  parts.  Rota-
ting baskets can be used on cross-rod  degreasers and  ferris wheel
degreasers but  are not normally retrofitted.   Drying  tunnels  can
be retrofitted  if space allows.  The effectiveness  of these  de-
vices has  not been quantified.
                                517
-------
          Recently two other systems have been developed for the
control of solvent bath and carry-out emissions.   The automated
cover-conveyor system has a cover which 'opens only for the pur-
pose of transferring parts into and out of the degreaser.  During
cleaning, draining, and drying the cover is closed.  Since emis-
sions can occur only during the brief time when parts are enter-
ing or exiting, the automated cover-conveyor system  is expected
to provide a high degree of emission control.

          Refrigeration condensation involves the direct conden-
sation of solvent vapors from exhaust air streams.  Very low
temperatures on the order of -25 C (-13 F) are required for effec-
tive condensation of low vapor concentrations.  The result is rapid
ice formation on heat exchange surfaces and increased energy re-
quirements.  One equipment manufacturer reported successful use
of refrigeration condensation technology in a prototype system.15

          Solvent reclamation is considered the best method for
reducing emissions from evaporation of waste solvent.  Reclama-
tion can be done through a-private contractor or in-house dis-
tillation.  Private contractors usually-collect waste solvent,
distill it, and return the ••re claimed portion.  Users are charged
about half the market value of the solvent.  This method is eco-
nomically attractive in industrial- areas where users.are not
separated by large distances.

          In-house distillation is common among users employing
several degreasers.  One report states that the annual operating
costs of an in-house reclamation system are recovered from the
first 1320 liters  (350 gal) of chlorinated solvents distilled.
For nonchlorinated solvents, the breakeven point would be six
to twelve times this quantity.16  In-house distillation involves
some significant problems.  These include disposal of distillate
bottoms containing metals and other contaminants, decomposition
                              518
-------
of chlorinated solvents,  flammability of nonchlorinated solvents,
formation of azeotropes,  and occurrence of adverse chemical re-
actions.

          Direct incineration is not as desirable as reclamation
since it does not result in a usable product.   Furthermore, chlori-
nated solvents cannot sustain combustion without supplementary
fuel.  Petroleum distillate solvents, however,  are more suitable
for incineration and can even be used as supplementary fuel for
the incineration of chlorinated solvents.

          Most chemical landfills are presently inadequate as
waste solvent disposal methods.  Chemical landfills would be
suitable if steps were taken to eliminate evaporation and per-
meation.  One method being used involves sealing the waste.sol-
vent in lined drums and surrounding these drums with 1.2 to 6.1 m
(4-20 ft) of packed clay.  It has not been demonstrated that even
this landfill method eliminates organic emissions.

4.19.4    Energy, Cost, and Environmental Considerations

          Discussions of costs, energy requirements and environ-
mental impacts are included in section 3 for the five major con-
trol methods:  adsorption, abs.orption, condensation, flaring, and
incineration.  There are some specific data for degreasing facili-
ties included in this section as well.

          Tables 4.19-3, 4.19-4, and 4.19-5 contain cost estimates
for  cold cleaners, open top degreasers,  and conveyorized degreaserj
Estimates are made for new and retrofit  conditions.

          There are several secondary  environmental effects to  be
considered with application of controls  to degreasers.  Improper
                                519
-------
NJ
O
               TABLE 4.19-3.  CONTROL COST ESTIMATES FOR TYPICAL COLD CLEANERS3>b>*7
                                    New Facilities                  Existing Facilities
                              * Volatility6  High Volatility6  Low Volatility*1High VolatJ
                              Solvent          Solvent           Solvent          Solvent
    Installed Capital            $25             $45               $25              $65
      Cost

    Annualized Cost              $0.50          -$29.84C           $0.50          -$25.61C
    aCosts are based on several assumptions.  See original reference for bases.
    bVapor to air area 0.5m2 (5.5 ft2).
    °Negative signs indicate that value of recovered solvent exceeds cost of control.
     Controls for low volatility solvent are drainage facilities.
    ^Controls for high volatility solvent are drainage facilities plus a mechanically
     assisted cover.
-------
        TABLE 4.19-4.   CONTROL COST ESTIMATES FOR OPEN TOP VAPOR  DEGREASER'
                                                                                   3,18,19,20
New Facilities

TYPICAL SIZEb
Installed capital
cost
Net annual ized
cost
SMALL SIZE0
Installed capital
cost
Net annual ized
cost
Manual
Cover

$250

-$807d


$230

-$381d

Carbon
Adsorption

$7400

$ 300


$7400

$ 962

Refrig-
erated
Chiller

$4900

-$ 191d


$2700

-$ 24d

Extended Manual
• Freeboard Cover
& Power
Cover

$2500 $300

/H» 631d -$799d


' $430 $270

-$490d -$375d
; *
Existing
Carbon
Adsorption

$10,300

$ 797


$10,300

$ 1,459

Facilities
Refrig-
erated
Chiller

$6500

$ 84


$4030

$ 204

Extended
Freeboard
& Power
Cover

$8000

$ 311


$ 570

-$ 466d

 Costs  are based on several assumptions.  See original reference  for bases.
 Vapor  to air area 1.67ra2  (18 ft*).
jVapor  to air area 0.8 m2  (8.6 ft2).                 .  ,
 Negative signs Indicate that value of recovered solvent; exceeds  cost of control.
-------
               TABLE 4.19-5.   CONTROL COST ESTIMATES FOR  CONVEYORIZED DEGREASERS
                                                                                           a, b,21,22
                                       New Facilities
                                                        Existing  Facilities
                          Monorail Degreaser    Cross-rod Degreaser   Monorail Degreaser    Cross-rod Degreaser
                          Carbon     Refrig^    Carbon     Refrig-    Carbon     Refrig-    Carbon     Refrig-
                         Adsorber    erated     Adsorber    crated    Adsorber    erated   Adsorber    erated
                                     Chiller              Chiller               Chiller               Chiller
   Installed capital     $11,800     $5,725     $11,800     $5000-;   $17,600     $8,550     $17,600    $7,460
   costs                •            -...-••
   Annualized costs
-$ 2,639°   -$4,221°
$   520    -$1066°   -$ 1,638C   -$3,734°   $ 1,516   -$  646r
to
   .Costs are based on several assumptions.  See original reference for bases.
    Vapor to air area 3.8 m2 (41 ft2)
   CNegative signs Indicate that value of  recovered solvent exceeds cost of control.
-------
maintenance of carbon adsorption systems and refrigerated chillers
could, in fact, result in increased volatile organic emissions.
Carbon adsorption systems have other secondary effects as well.
The steam required for regeneration causes a slight increase in
boiler emissions, and the condensate from steam regeneration of
the beds may cause a water pollution problem due to contamination
with organic materials.  Solvent associated with waste water may
enter the sewer, thus eventually reaching water systems.  Evapora-
tive emissions may also result from the condensate.  Solid waste
is created when spent carbon is discarded.

          Handling of waste solvent may cause some environmental
problems.  Incineration creates emissions of NOX and CO, an4»..-•-. •-
combustion of chlorinated'solvents requires. -gas cleaning-to; pre---....
vent emissions of toxic and corrosive substances.  Distillation
requires steam, thus increasing boiler emissions.  Disposal of
waste solvent by landfill is unacceptable- because of the"potential
for leakage into the -environment.

        •  The large energy, consumers in degreasing control methods
are carbon adsorbers, refrigerated -chillers, and distillation
units.  Carbon adsorbers" consume the greatest amount of  energy'be-
cause of the steam regeneration step.  Energy consumption of a
typical -d-egre-aser may be increased 20 percent by a carbon adsorp-
tion  system..!3  A typical refrigerated freeboard chiller may-in-
crease energy  consumption of a typical degreaser by  5  percent.2"
Distillation requires about 0.1 to 0.2 kWh/kg  (160 to  320 'Btu/lb)
recovered solvent, but  the cost of the distillation  energy  is
considered insignificant.25   Power requirements for  powered covers
and power hoists are also considered insignificant.  In  all  cases,
the energy expended to  conserve the solvent is far less  than the
sum of the energy required to manufacture replacement  solvent  and
the heating value of the feedstock to this manufacturing process
which otherwise could have been used as fuel.26
                               523
-------
4.19.5    References

1.  Environmental Protection Agency, Control of Volatile Organic
    Emissions from Organic Solvent Metal Cleaning EPA-450/2-77-022.
    November 1977.  pp. 2-6.

2.  Danielson, John A. (ed.)  Air Pollution Engineering Manual
    2nd Ed.  Environmental Protection Agency.  May 1973.

3.  ASTM, D-26.  Handbook of Vapor Degreasing.  ASTM Special
    Technical Publication 310A, Philadelphia.  April 1976.
    As cited on p. 2-23 of Reference 1. ..

4.  Personal Communication between John Bellinger (EPA) and Ken
    Suprenant  (Dow Chemical Company).  March 3, 1977.

5.  Reference  1, pp. 3-22 to 3-23.

6.  Information provided by F. X. Barr, Graymills Co., Chicago,
    by telephone to J. L. Shumaker, EPA, January 13, 1972.  As
    cited on p. 3-23 of Reference 1.

7.  Information provided by K. S. Suprenant, Dow Chemical,
    Midland, Michigan, by telephone to J. L. Shumaker, EPA,
    January 11. 1977.  As cited on p. 3-23 of Reference .1.

8.  Suprenant, K. S. and D. W. Richards of Dow Chemical Company.
    Study to Support New Source Performance  Standards  for Sol-
    vent Metal Cleaning Operations, Vol. 2,  prepared for ESED
    under Contract #68-02-1329, Task Order #9, June 30, 1976.
                                524
-------
  9.  EPA  estimates based on Appendix  C-12  of  Reference  8  and data
     provided by Dupont.  As  cited  on p. 3-5  of  Reference 1.

 10.  Bellinger, J. C.  Trip Report - Collins  (now Rucker Ultra-
     sonics) Inc.  EPA report to D. R.  Patrick on trip  to Concord,
     California.  November 5,  1976.   As cited on p.  3-8 of Ref-
     erence  1.

 11.  Reference  8.  Appendices C-3,  C-5, and  C-7.

 12.  Reference  2.

 13.  Reference  8.

 14.  Reference  1, p.  3-31.

 15.  Refere-n-ce  1, p. -3-22.

 16.  Reference  8.

• 1.7.  Private communications,  Frank  L. Bunyard, QAQPS,  EPA, to
     Jerry Shields, •Manager of Marketing,  Graytaills,  Chicago.
  ;.  'August, 1976.  As cited-on p.  4-fr"of  Reference 1.

 18.  Reference  8.

 19.  Private .communication,. .Frank L,  Bunyard, OAQPS,  EPA  to
     Parker  Johnson,  Vice President of  Sales, Baron Blakeslee
     Corp.,  Cicero, 111.  March  16, 1977.  As cited on p. 4-12
     of Reference 1.
-------
20.   Private communication,  Frank L.  Bunyard,  OAQPS,  EPA to
     Dick Clement, Detrex Chemical, Detroit,  Michigan,  March
     21, 1977.   As cited on p.  4-12 of Reference 1.

21.   Reference 8.

22.   Reference 1,  p. 4-19.

23.   Reference 20.

24.   Reference 1,  p. 5-5.

25.   Reference 8.

26.   Reference 1,  p. 5-6.
                                526
-------
 4.20       Cutback Asphalt

           Cutback asphalt is a prepared form of asphalt cement
 used  for paving.   Asphalt cement is the semi-solid residue that
 remains  after all other components of crude petroleum have been
 distilled off (either naturally or in refineries).  It may be
 used  directly for paving or it may be liquified.  There are two
 types of liquified asphalt.

           -1)   Cutback asphalt-prepared by diluting asphalt
               cement with volatile petroleum distillates, and

           2)   Emulsified asphalt-prepared by suspending asphalt- •
 ,-....            cement in water with an _ emulsifying agent, -;sueh .--
               as  soap.                     •'           • ,;•--.,. •""

••Liquified,.asphalts are -formulated in .a wide variety of types ' •
 an-d grades, .-•>•       .  .-- /  .-,        -       —     •       . .     •'.

           Uses of asphalt for pavements'range from a thin spray
 to control dust on a dirt road to thick layers  of asphalt mixed
 with  aggregate- (crushed.-rock,-gravel or sand) placed on a well
.prepared bed.  Heat requirements for application vary for "the
 different forms of asphalt.  Asphalt.,.cement must be heated to be
 converted to a..usable liquid..  A small  amount of  heat  is usually
 required to--facilitate  spraying of cutback asphalts.  Most enul-
:.-sified asphalts require no heat at all.1

    .  •••'-    The percentage' of paving operations that use  cutback
 asphalt varies widely from state to  state.  A total of  3.72 Tg
 (4.10 x 10fi tons) of cutback asphalt were used  nationally  in
 1975.2
                                527
-------
4.20.1    Emission Characteristics

          Cutback asphalts  are  a  significant source of volatile
organics emissions.  Annual emissions  from cutback asphalts in
1975 were estimated  to be 673 Gg  (742xl03  tons).  This is 2.3%
of the 1975 national volatile organic  emissions.3

          Cutback asphalts  are  considered to be moderately to
highly reactive in terms of oxidant formation.  The environmen-
tal impact is compounded because  road  paving occurs primarily
during the warmer months when the photochemical activity of vola-
tile organics is more prevalent.

          The petroleum distillate content of cutback asphalts
averages 357». "  A proportion of these  diluents is evaporated to
the atmosphere as the asphalt cures.  Cutback asphalts fall into
three general categories, depending on the volatility of the
diluent.  A list of  these categories along with estimates of the
proportion of the diluent that  will evaporate is presented in
Table 4.20-1.

      TABLE 4.20-1.  CHARACTERISTICS OF CUTBACK ASPHALTS

    Category                 Diluent        Proportions of Diluent
                                              Evaporated5

  Slow cure (road oil)      Heavy residual oil     .  20-30%
  Medium cure             Kerosene               60-80%
  Rapid cure              Heavy naptha or          70-90%
                          gasoline
                               528
-------
          The kinetics of evaporation are not well understood.
It is thought that most emissions occur early during paving  op-
erations.  The diluents then continue to evaporate at  ever de-
creasing rates over a long period of time.6

4-20.2    ControlTechniques

          Substitution of emulsified asphalts for cutback as-
phalts is an effective control technique.  Most  emulsified as-
phalts have virtually no volatile organic emissions.7  Emissions,
therefore, can essentially be reduced to zero.   Some form of.
emulsified asphalt can be used for almost any application. -  There  ••
are a few applications,'"however, for which cutback asphalts  may
still be needed.           •                          '.       ..-••-••

          Emulsified asphalts .'.are classified as  noni'onic, ,'an.ionic,
or cationic, depending on the.,.type of,.emulsifying agent  used'.
Nonionic and anionic emulsified asphalts cure  (break)  with the
evaporation of water.  Cationic emulsified asphalts cure by
electrochemical interactions, between the emulsion and  a  negatively
charged aggregate.8     -.    ..

          There are several limitations to the use of  emulsified
asphalts:9

          1.) "Because they -depend on the evaporation of
           .<•  water, non-ionic -and anionic emulsified as-
             phalts cannot be used when rain is antici-
              pated or when temperatures fall below 10°C
              (50°F) .
                                529
-------
          2)   Dust causes the emulsion to break prema-
              turely.   Emulsified asphalts, therefore,
              cannot be used to spray on dusty roads
              unless the roads are swept prior to spray-
              ing.

          3)   Emulsified asphalts cannot be stockpiled
              as long as cutbacks.  This is a problem
              for remote locations; however, it can be
              solved by using portable mixing plants or
              by stockpiling an asphalt emulsion mix.

          4)   Emulsified asphalts have a longer curing
              time than cutback asphalts.  Roads may have
              to be closed to traffic for two hours to
              two days, depending on the weather.

          5)   Additional training is necessary to learn
              how to select and effectively use the proper
              formulation of emulsified  as-phalt.  One or
              two days training is sufficient.

4.20.3    Cost, Energy. ap
-------
           In 1975,  1,600,000 m3 (10,000,000 barrels) of petroleum
 distillates  were used to formulate cutback asphalt.11  All  of
 these  distillates were evaporated to the atmosphere  or trapped  in
 the  asphalt.   These same distillates could have been used for or
 converted to fuel.   Including the energy equivalent  of the.  diluent,
 the  total energy associated with manufacturing, processing,  and
 laying cutback asphalts is about 14.0 GJ/m$ (50,200  Btu/gal).   The
 associated energy requirement of emulsified asphalts is only about
 0.789  GJ/m3  (2,830  Btu/gal).12

           According to available literature, there is virtually
 no environmental impact related to the use of emulsified asphalt,

 4.20,4   . -Refer etxces. ..   ••••--,...'    -.•"•-     •   ••'-.   . ...     /: '-'• v-~'"v .  •'

••I-*-, KirwanV "'""Francis M. -and Clmrence .Maday, • Air • Quality -and';'.
     Energy Conservation Benefits from Using Emulsions to Re*
     place Asphalt Cutbacks in Certain Paving Operations.  Draft
     Report Strategy and Mr Standards Division, OAQPS, U.S.
     fePA,  Research Triangle'Park, N.C.  December 1977.

 2.   U.S.  Bureau of  Mines,  Mineral Industry Surveys.  Sales  of
     Asphalt in"1975.  July 19» 1976.  As cited in Reference 1.

 3,   Reference-*!,', '-•  •.  '•  -••   '-*•••      ••-•              •

 4.   Foster,  Charles R. and Fred Kloiber.  Fuel Conservation.
     Special National Asphalt.Pavement Association Report.
     As cited in Reference 1.                     '

 5.   Reference 1.             •    •  -'  •

 6.   Reference 4.                    .  -     .    ... --       :,  . ,

                                531                        "    '
-------
   7.  Kandhal, Prithvi S.   Let's Get Acquainted with Asphalt
       Emulsions.   Testing and Research Informational Reports.
       Commonwealth of  Pennsylvania, Department of  Transportation,
       Bureau of Materials.   April 1974.  As cited  in Reference 1.

8-12.  Reference 1.

  US GOWRNMIWT PRINTING Of HCI: 19?8.?«-26)«tSl
                                   532
-------