EPA-450/3-78-018
April 1978
EVALUATION
OF CONTROL TECHNOLOGY
FOR BENZENE
TRANSFER OPERATIONS
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Waste Management
Office of Air Quality Planning and Standards
esearch Triangle Park, North Carolina 27711
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EPA-450/3-78-018
EVALUATION OF CONTROL TECHNOLOGY
FOR
BENZENE TRANSFER OPERATIONS
by
S.W. Dunavent, D. Gee, and W.M. Talbert
Pullman-Kellogg
16200 Park Row, Industrial Park Ten
Houston, Texas 77084
Contract No. 68-02-2619
EPA Project Officer: David Markwordt
Prepared for
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air and Waste Management
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
April 1978
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This report is issued by the Environmental Protection Agency to report
technical data of interest to a limited number of readers. Copies are
available free of charge to Federal employees, current contractors and
grantees, and nonprofit organizations - in limited quantities - from the
Library Services Office (MD-35), U.S. Environmental Protection Agency.
Research Triangle Park, North Carolina 27711; or, for a fee, from the
National Technical Information Service, 52S5 Port Royal'Road, Springfield,
Virginia 22161.
This report was furnished to the Environmental Protection Agency by
Pullman-Kellogg, 16200 Park Row, Industrial Park Ten, Houston,
Texas 77084, in fulfillment of Contract No. 68-02-2619. The contents of
this report are reproduced herein as received from Pullman-Kellogg.
The opinions, findings, and conclusions expressed are those of the author
and not necessarily those of the Environmental Protection Agency. Mention
of company or product names is not to be considered as an endorsement
by the Environmental Protection Agency.
Publication No. EPA-450/3-78-018
11
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CONTENTS
Page No.
1.0 INTRODUCTION 1
2.0 SUMMARY 3
3.0 CONCLUSIONS/RECOMMENDATIONS 7
4.0 DISCUSSION 9
4.1 Control Technologies 9
4.1.1 Refrigeration-Condensation-
Absorption 9
4.1.2 Carbon Adsorption 11
4.1.3 Thermal Incineration 13
4.1.4 Other Technologies Considered. . . 14
4.2 Base Study Cases 17
— 4.2.1 Benzene Producer 17
4.2.2 Benzene Consumers 24
•
4.3 Application of Control Technologies to
Base Case 28
4.3.1 Producer Cases 28
4.3.1.1 Case Number Two 28
4.3.1.2 Case Number Three 30
4.3.1.3 Case Number Four 32
4.3.1.4 Case Number Five 32
iii
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CONTENTS (Cont)
4.3.2 Consumer Cases
4.3.2.2 Case Number Sight . . .
*
4.4 Emissions
4.4.1.1 Case Number One . . . .
4.4.1.2 Case Number Two . . . .
4.4.1.3 Case Number Three . . .
4.4.1.5 Case Number Five . . .
4.4.1.6 Case Number Six . . . .
4.4.1.8 Case Number Eight . . .
4.4.2 Secondary Emissions
4.4.2.1 Solid Emissions ....
4.4.2.2 Liquid Emissions. . . .
4.5 Operation of Control Systems
4.5.1 Safety
4.5.1.2 Case Studies
4.5.1.3 Other Considerations. .
4.5.2 Reliability ;
Page Mo.
. . 35
. . 35
. . 37
. . 41-
. . 41
. . 43
.. ._. .._43- -
. . 45
. . 45
. . 45
. . 46
. . 46
. . 46
. . 48
. . 48
. . 48
. . 49
. . 50
. . 50
. . 50
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. . 53
. . 54
IV
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CONTENTS (Cont)
Page No
4.5.3 Operation 55
4.5.3.1 Transfer of Vapors from
Carriers 55
4.5-3.2 Transfer to Treatment
Units 56
4.5.3.3 Storage of Benzene
Vapors Using a
Nitrogen Gas Blanket. ... 58
4.5.3.4 Transfer of Vapors from
Storage to Treatment .... 59
4.6 Economics 60
4.6.1 Capital Costs 60
4.6.1.1 Basis for Estimates 60
4.6.1.2 Discussion of Cases 62
4.6.2 Total Annualized Costs 65
4.6.3 Economic Analysis 70
APPENDIX A—Legend
APPENDIX B—English to Metric Conversion Chart
APPENDIX C—Capital Cost Data
APPENDIX D—References
APPENDIX E—List of Vendor Brochures
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INDEX OF TABLES
Page No,
Table 4.2.1 Benzene Emissions Inventory for
Producer Base Case ............ 22
Table 4.2.2 Benzene Emissions Inventory for _ _.. _____ .. _
Consumer Base Case ............ 27
Table 4.4.1.1 Benzene Emissions Inventory for
Producer Control Cases .......... 44
Table 4.4.1.2 Benzene Emissions Inventory for
Consumer Control Cases .......... 47
Table 4.6.1 Total Capital Costs of Control Cases
for Each Technology ........... 66
Table 4.5.2.1 Total Annualized Costs for Benzene
Producer Control Cases .......... 68
Table 4.6.2.2 Total Annualized Costs for Benzene
Consumer Control Cases .......... 69
Table 4.6.3.1 Cost Effectiveness of Producer
Control Cases .............. 71
Table 4.6.3.2 Cost Effectiveness of Consumer
Control Cases .............. 72
VI
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INDEX OF FIGURES
Figure 4.1.1
Refrigeration-Condensation-
Absorption Unit
Figure 4.1.2 Carbon Adsorption Unit . .
Figure 4.1.3 Thermal Incineration Unit
Figure 4.2.1 Base Case #1 - Benzene Producer
Figure 4.2.2 Base Case #6 - Benzene Consumers
Figure 4.3.1.1 Control Case #2 - Benzene Producer . . . .
Figure 4.3.1.2 Control Case #3 - Benzene Producer . . . .
Figure 4.3.1.3 Control Case #4 - Benzene Producer . . . .
Figure 4.3.1.4 Control Case #5 - Benzene Producer . . . .
Figure 4.3.2.1 Control Case #7 - Benzene Consumers. . . .
Figure 4.3.2.2 Control Case #8 - Benzene Consumers. . . .
Figure 4.5.1 Benzene Vapor Saturator
Page No,
10
12
15
18
25
29
31
33
34
36
38
52
vii
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SECTION 1.0
INTRODUCTION
The specific objectives of the study were to:
1) Assess the feasibility of applying vapor control
technology for benzene transfer operations including
tank cars, railcars, badges, tankers, stora^-e-t-a-ntcs-,
and pipeline operations.
2) Determine the achievable emission level and emission
reduction for each vapor control alternative.
3) Determine any secondary emissions that would result
from applying each vapor control alternative.
4) Quantify the capital.and annualized costs of the
control alternatives.
Visits were made to the plants of two benzene producers to gather
information on liquid benzene storage and transfer operations. A
literature search was conducted to obtain data on benzene
handling and storage, as well as to investigate technological
aTtef"naTti'vVs to control emissions. This activity was brief
because of the desire to evaluate technologies that could readily
be applied to industry. Equipment manufacturers were consulted to
determine the state-of-art of commercially available equipment
and_ascertain the effectiveness, cost, and operating history of
their treatment units. Three technologies exhibited promise as
effective methods to reduce benzene emissions, and were selected
for further' study. These were a refrigeration and lean oil
absorption unit, vacuum regenerated carbon adsorption, and
thermal incineration.
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Hypothetical models were prepared to represent a typical
current-day benzene producer, and two benzene consumers. These
models serve as base cases for the study. Six control schemes
were developed and applied to the base cases. Four were applied
to the producer, and two to the consumers. Each of the three
control technologies discussed above were applied utilizing their
respective achievable emission levels to the control schemes
resulting in 16 case studies. The cost effectiveness of each
case study was calculated, and the technologies rated.
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SECTION 2.0
SUMMARY
The three control technologies evaluated were:
1) Condensation of benzene vapors by refrigeration
followed by absorption of benzene vapors, .i-n—a-a -o-il
absorbing/stripping system.
2) Carbon adsorption beds regenerated by vacuum.
3) Thermal incineration using supplemental fuel.
Other technologies were considered, but dropped because of lack
of design information and/or commercial availability.
The control technologies were evaluated by applying them in
various configrations to hypothetical models which were prepared
to represent facilities and operations typical of current-day
p-ro-dtrcrers"and consumers of benzene.
Each of the technologies embody basic principles whose successful
application to hydrocarbon processing has been well demonstrated,
and for which large data bases exist. Their application to
benzene emission control is very limited and actual performance
data was not available. The transfer of technology from other
hydrocarbo-ns services to benzene service is not expected to
create unusual problems. All of the technologies are currently
being applied to gasoline emission control, and this experience
is useful.
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The claimed removal efficiencies of the three technologies
studied are all high. The predicted benzene emission concen-
tration levels that are practical to achieve are:
Refrigeration-absorption - 1000 ppm
Carbon adsorption - 10 ppm
Thermal incineration - 10 ppm
The technologies were evaluated using the above emission levels.
The economic penality for installing and operating a thermal
incinerator at 10 rather than 1000 ppm is small. This is not the
case with carbon adsorption and a meaningful economic comparison
of this technology can only be made when it and competing tech-
nologies are evaluated at the same emission concentration level.
Using the above emission levels, refrigeration-absorption has a
cost effectiveness very close to that of thermal incineration.
Average cost effectiveness of the refrigeration-absorption
systems is $3«83/lb reduction, while that of thermal incineration
is $3-78/lb reduction. (Note: Units used in this report are the
same as used by suppliers of raw data. A metric conversion chart
is contained in Appendix A.) This is a negligible difference. A
slight rise in the value of benzene and/or the cost of natural
gas relative to electricity would make refrigeration-absorption
the most cost effective. Although there is no single component
in_tjie system that is unique; i.e., closed loop refrigeration
vapor scrubbing tower, gas-oil separation by distillation; the
combination of these components into a single package for remote
automatic efficient operation is not yet demonstrated. This
system is thought to need more control and fine tuning than the
other technologies to achieve efficient operation. A great deal
more operating experience would likely be required to make this
technology widely accepted. What makes refrigeration-absorption
particularly attractive is its potential to be the most cost
effective and its conservation of benzene.
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Thermal incinerator technology has been used more in the control
of storage and transfer emissions than the other two techno-
logies. The transfer of gasoline handling knowledge to benzene
handling is much more direct than that of the other technologies.
The state of the art for thermal incineration is at a high level,
and potential improvements are possible with energy recovery by
heat exchangers. Advantage was not taken for heat recovery -in
the case study models. Also the particular commercially
available thermal incinerators investigated did not offer heat
recovery as a regular option. If heat recovery is a possibility
for any particular plant, thermal incineration would be even more
cost effective. Standard thermal incineration units are
available as "off the shelf" items from at least two
manufacturers.
Vacuum regenerated carbon adsorption with 10 ppra emissions was
calculated to be the least cost effective means of controlling
benzene emissions but at 1000 ppm emissions may be competitive
with other technologies. On a functional basis, carbon adsorp-
tion stands out as the most attractive technology. It has a very
high efficiency of benzene recovery and removal, relatively
simple operation well suited for automation, and wide turndown
ranges. Experience with benzene is presently limited to extrapo-
lation__of results gained from gasoline service with gasoline con-
taining benzene. Substantial advancement in the state of the art
is expected as more experience is obtained.
•
Steam regenerated carbon systems have wide experience in the
treatment and recovery of solvents from solvent contaminated air
in extremely dilute concentrations. These units are available
from several manufacturers as standard package items. However,
no experience was found pertaining to benzene, gasoline, or high
concentration hydrocarbon usage. No pricing estimates for
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benzene applications of steam regenerated systems were available.
Some means for disposal of benzene contaminated condensate is
necessary for this type system.
Calculations revealed that there is considerably more benzene
lost as a result of loading and storage (per unit of benzene
handled) by producers than for consumers. The emission factor
for the base case producer is 2.608 lb/10 gallons compared to
.468 for the consumer case. Floating roof tanks represent a high
level of control. (Texas state regulations require floating roof
tanks for the base case.) Conversely if a plant has cone roof
tanks, the first efforts should be directed to reducing storage
losses by conversion to either open floating roof or internal
floating cover depending on their relative cost effectiveness.
Either method is highly cost effective.
When the implementation of carbon adsorption technology is
desired, the most cost effective design will incorporate features
to reduce the capacity (in terms of benzene loading and volu-
metric flowrate) of the individual treatment units, permit higher
ppm emissions, and minimize the number of units required. Capa-
city reducing features might include vapor holders to act as flow
equalizers and displacement of vapor from tank to tank or carrier
to tank. The additional cost due to capacity reducing measures
will. b_e__m.Qre. than offset by the savings in capital costs of the
carbon adsorption units. Capacity reducing measures do not
provide similar cost effectiveness gains for refrigeration-
absorption and thermal incineration technologies. The increased
cost of the capacity reduction measures outweighs the cost
savings obtained by reducing the size and number of treatment
units.
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SECTION 3.0
CONCLUSIONS AND RECOMMENDATIONS
Conclusions and recommendations are:
1) It is concluded that thermal incineration offers the
best means for control of'benzene vapor to Lev-fils—o-f-1-0
ppm benzene. The risk in applying this technology to
benzene service is considered to be low. Thermal
incineration systems have the distinct advantage of
being able to dispose of other pollutants.
2) Thermal incineration at the level of 10 ppm benzene
emission and refrigeration-adsorption at 1000 pprn are
equal in cost effectiveness.
3) Carbon adsorption is not as cost effective as thermal
incineration when both are compared at 10 ppm.
4) The cost of carbon adsorption is sensitive to final
benzene emission level and a true cost comparison to
other technologies can only be made when all tech-
, nologies are evaluated at the sane emission level.
5) Benzene emission control efforts are more cost effective
in producer rather than consumer facilities. Plants
with cone roof storage tanks should receive attention
before those using floating roof tanks. When the
producer plant is equipped with floating roof tanks, the
priority shifts to controlling the loading losses.
6) Mo.difications to carriers to reduce transit losses
(defined as breathing losses during shipment) should
receive the lowest priority. Modifications to carriers
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should be limited to those which are required to reduce
loading losses.
7) Secondary emissions for the control systems evaluated
were low, and do not present a significant problem.
8) Air-benzene mixtures in pipe lines to recovery systems
introduce significant explosion hazards, and designs
must incorporate equipment to avoid this hazard. (This
was done for designs evaluated in this report.)
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SECTION 4.0
DISCUSSION
4.1 CONTROL TECHNOLOGIES
4.1.1 Refrigeration - Condensation - Absorption
(See Figure 4.1.1) — ----------
This type of recovery system removes benzene vapor from air in
two stages. The first stage consists of passing the vapor mix-
ture over a surface condenser maintained at 45°F. The tempera-
ture is controlled to prevent the freezing of benzene. Up to 60
weight percent of the benzene vapor is condensed and collected
along with some water. The condensed benzene is returned to
storage. The remaining vapor mixture is passed through the
second stage which consists of a lean oil scrubber maintained at
35°F. The benzene vapor is absorbed into the lean oil. The lean
oil is collected and either regenerated or stored for later re-
generation. The vent to atmosphere from this type unit contains
1,000 ppm benzene by volume.
The regeneration process heats the benzene-rich oil to 350°F
where benzene is stripped from the oil. This benzene vapor is
then condensed, collected, and returned to storage. The hot lean
oil' is cooled down to 35°F and reused. The non-condensed benzene
vapor is recycled to the first stage by means of a vacuum pump.
All of the condensing and cooling is provided by a closed loop
refrigeration unit.
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1000 PPM
6
1. Vent From Tanks
2. Condenser
3. Pump-Ref. Module
4. Scrubber-Absorber
5. Regenerate Pump & Refrigeration Module
5A Heater
5B Benzene Condenser
5C Receiver
5D Pump
5E Refrigerated Chiller
5F Purge Pump
6. Tail Gas Vent
7. Benzene Return Pump
8. Benzene Return Pump
Basic Drawing Courtesy of
Ecology Control Inc.
FIGURE 4.1.1 REFRIGERATION-CONDENSATION-ABSORPTION UNIT
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Several variations of this type system can be made. Where a high
flowrate of vapor is scrubbed (such is the case during a barge
loading), the benzene-rich oil can be stored and regenerated at a
later tine using a smaller regenerator unit. This reduces the
capital cost.
Another variation separates the condensor and scrubber tower from
the electrically driven hardware so" that a smaller size and
weight unit could be placed in a crowded spot such as a loading
doc'k.
Still another variation does away with the refregerati_o-n~c-o-n-den-
sation first stage and used only lean oil absorption. The re-
frigeration load required however is about the same and the rich
oil regnerator increases in size.
The two-stage system is being used successfully on West Texas
crude in Silsbee, Texas. Ecology Control Inc. manufactures these
units. A unit capable of handling 2,000 gpm of .displaced benzene
vapors costs about $87,000.
4.1.2. Carbon Adsorption
Carbon adsorption utilizes the principle of carbon's affinity for
no-n-pola-r—4hydrocarbon) solvents to remove benzene from the vapor
phase. Although benzene applications of carbon adsorption do not
have a large amount of commercial operating experience, carbon
adsorption for recovery of other organic vapors is proven, and
transfer of this technology to benzene should not prove diffi-
cult. A typical benzene carbon adsorption unit consists of a
minimum of two carbon beds and a regeneration system. (Refer to
Figure 4.1.2.) Two or more beds are necessary to keep the unit
onstreain, so that one will be ready for use while the other bed
is being regenerated. Regeneration can be performed by two
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OPPM
ARrtESTOR
VAPOR
Basic Drawing Courtesy of
Hydrotech Engineering Inc
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different methods. Both rely on elevating the vapor pressure of
the adsorbed benzene in relation to the absolute pressure in the
void space of the bed and sweeping the void space. In the steam
regeneration system steam heats the carbon (raising the benzene
vapor pressure) as it is circulated through the bed. Thus the
benzene evolved is removed along with the steam. The steam-
benzene mix is condensed (usually by an indirect cooling water
stream) to recover benzene and water in a separator- The benzene
is decanted and returned to storage and the water is sent to the
plant wastewater system for disposal. For a steam regeneration
system cooling water, electricity, and of course, steam are the
required utilities. While it is possible to use a closed^ loop
freon refrigeration system for the condenser, the large duty
required makes it impractical. Vacuum regeneration is performed
by drawing a high vacuum on the carbon bed with a liquid ring
seal vacuum pump. The benzene vapor thus desorbed is condensed
by indirect cooling and returned to storage. The condenser may
be cooled either by a closed loop freon refrigeration unit or by
circulating cooling water. The only utility required for vacuum
regeneration is electricity unless a water cooled condenser is
used instead of a freon refrigeration unit. This method
eliminates the problem of disposing of water containing trace
amounts of benzene. A 2000 gpm unit for benzene service was
priced at $742,000 by Hydrotech Engineering Inc. as an order of
magnitude engineering estimate for the particular loading system
in the study.
4.1.3 Thermal Incineration
Thermal incineration is the most direct means of benzene vapor
disposal, uses the fewest moving parts, and is the simplest to
operate. The vapor mixture is injected via a burner mani-fold
into the combustion area of the incinerator. Pilot burners
provide the ignition source and supplementally fueled burners add
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heat when required to maintain the flame temperature between
1400°F and 1500°F. The fuel was assumed to be natural gas;
however, its future availability is questionable. A negative
aspect of thermal incineration is the fact that benzene is
destroyed.
The amount of combustion air needed is regulated by temperature
controlled dampers. Benzene emission from the tail gas of an
incinerator can be limited to as little as 10 ppm. (See Figure
4.1.3.)
Flash back prevention and burner stability are achieved by either
saturating the vapors to a concentration above the upper explo-
sive limit or inerting them with nitrogen. (See Figure 4.5.1.)
In addition, two water seal flame arresters are used to assure
that flash backs do not propagate from the burner to the rest of
the piping system.
Thermal incinerators are being used successfully to dispose of
gasoline vapors collected from tank truck loading operations.
National Air Oil manufactures ten sizes of units ranging from 500
gpm to 5,000 gpm. They have successfully tested their standard
unit (with a few modifications) with benzene vapor. These units
range in cost from $35,800 to $51,700. A significant advantage
of--th^r-mal-incinerators is that they can dispose of a wide range
of hydrocarbons. This is especially important at a loading dock
where numerous hydrocarbons are loaded, and industry is uncertain
of what materials in the future will have to be controlled.
4.1.4 Other Technologies Considered
Catalytic oxidation was considered for benzene vapor control ser-
vice but was dropped because of problems associated with catalyst
fouling. The catalytic oxidation system in general offers a
14
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0 PPM
I
PILOT
BURNER
FUEL
VAPOR
BURNER
-STACK
MAIN BURNER
FUEL x
AIR DAMPER-
BENZENE
VAPOR SOURCE
FIGURE 4.1.3 THERMAL INCINERATION UNIT
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savings in fuel over thermal incineration due to lower operating
temperature.
Another technology considered was straight refrigeration. This
system recovered the benzene vapor in two stages. In the first
precooler condenser, the vapors are cooled to 43°F where the
benzene and water vapor condense and are removed from the vapor
stream. In the final condenser, vapors are cooled to -100°F.
The residual benzene vapor and residual moisture collect as a
frost on the condenser fins. At the end of the flowing period,
the condenser is warmed to 43°F and both benzene and water are
drawn off. There are currently no commercial installations of
this type system although the claim is made by the manufacturer
that an emission level as low as 10 ppm can be achieved. The
cost for a unit that will handle 2,000 gpm of displaced benzene
vapors runs between $95,000 to $110,000 as provided by Edwards
Engineering. The technology was not evaluated in the case
studies because of the state of development of the technology and
the availability of design in f o rm-at ion* within the time
limitations of the study.
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4.2 BASE STUDY CASES
Three bass study cases were selected to represent "typical"
uncontrolled benzene producers and consumers. The characteris-
tics of these cases were formulated from information obtained
from plant visits, published data, and conversations with operat-
ing personnel. These cases will be described below. The three
base cases are:
o Producer
o Large consumer
o Small consumer
4.2.1 Benzene Producer
A Texas Gulf Coast location was chosen as the site of the benzene
producer for two reasons; 1) a large number of benzene plants are
located on the Gulf Coast in Texas and Louisiana, and 2) all
•
modes of benzene tran'sfer are possible from such a location. The
capacity of the production unit is 40 million gallons per year of
petroleum-derived benzene. Benzene is pumped from the production
unit into a pair of intermediate storage tanks known as rundown
tanks, where it is inspected for product qual ity. (Figure 4.2.1)
The rundown tanks are of pontoon, double seal floating roof
c-onsUiuciion, with welded steel shells. The height of the tanks
are 43 feet and the diameters are 25 feet. The working capacity
per tank is 125,000 gallons, approximately one day of production.
The tanks are alternately filled, the product tested, and then
emptied to other storage tanks. The bulk liquid temperature of
the benzene in the rundown tanks is approximately 100°F, with an
associated vapor pressure of 3-30 psia. From the rundown tanks
the benzene is transferred to one of two sets of final pr'oduct
shipping tanks. One set is for rail car/truck loading and tne
other set is for barge loading. The transfer rate from the
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PRODUCTION
UNIT
40 MM GAL/YR^
76 GF'M '
oo
-XI-
-txl—-,
2 RUN
)OWN TANKS
12 5,000 GAL EACH
25'0 X40'
28 MM
GAL/YR
2 RAILCAR-TANK TRUCK
SHIPPING TANKS
420,000 GAL EACH
A O' lit II AQl
42'0 X
12 MMGAL/YR
265 GPM—.
350GPM
350GPM
txj—'
10 MM GAL/YR
350 GPM
uu uo
n.R.CAR
2QOOOGAL EACH
4 MM GAL/YR
350 GPM
LXJ CT
TANK TRUCK
8000 GAL EACH
26 GPM
12 MM GAL/YR
2 mfi^mj&B1* 2otoGPM
47'0 X 56*
420,000 GAL BARGE
FIGURE 4.2.1. BASE CASE #1 - BENZENE PRODUCER
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rundown tanks is 265 gpm, thus eight hours are required for
transfer. Two 100? capacity pumps are provided for this
s e rv i o e.
The two tanks provided for railcar/truck shipping service are
fitted with pontoon, double seal floating roofs and welded steel
shells. The tanks are 42 feet in diameter and 43 feet high, with
a net working volume of 420,000 gallons each. The annual ben~ze"ne
fill for the railcar/truck shipping tanks is 28 million gallons.
Of this volume, 14 million gallons are shipped directly out of
the plant by pipeline. The pipeline transfer rate is assumed to
be a continuous 26 gpm and one of two 100? capacity _pum_n.s. _are
used. The remaining 14 million gallons per year are shipped out
by railcar and truck. Railcars receive 10 million gallons per
year and the truck tankers receive the remaining 4 million
gallons per year- The capacities of the railcars and trucks are
assumed to be 20,000 gallons and 8,000 gallons respectively.
Thus there are 500 railcar shipments and 500 truck shipments each
year. The railcars and trucks are filled by loading arms en two'
separate dedicated racks. The normal fill rate is 350 gpm and
two 100« capacity pumps are provided.
Loading procedures for railcars and trucks are similar. After
the vehicles are properly spotted, checked, and grounded, the
l^adi^g hatches are opened and the loading arms connected;
Although other loading styles are commonly employed for hydro-
carbon liquid loading, it was assumed that submerged fill top
loading is used. This is the style that was observed on plant
visits. In submerged fill top loading, the loading nozzle is
in's'erted into a fixed standpipe which is kept submerged in the
liquid near the bottom of the tanker to minimize splashing and
subsequent benzene losses. The vapor in the tanker is displaced
3v the liquid oenzene during filling and is expelled through the
19
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open hatchway to the atmosphere. No vapor recovery system is
employed in the base case.
Loading is under manual control, tank gauging is performed either
by visual inspection of liquid level through -the hatchways or
floatsticks. As the liquid level nears the maximum the flowrate
is reduced while the operator monitors the level closely. The
tank is then topped off to 2% outage, the loading arm valve is
blocked off, the pump is shut off, the arm is removed, and the
hatchway is closed.
The remaining 12 million gallons per year is sent to the barge
shipping tanks. The barge shipping tanks are 630,000 gallons net
working capacity each. These tanks are also pontoon, double
seal, floating roof, welded shell construction. The tank height
is 56 feet and the diameter is 4? feet. The benzene is pumped to
a loading dock manifold where it then enters a marine- loading
hose which is connected to the barge loading manifold. A minimum
of three persons are involved when loading a barge. A barge in-
spector must certify that the barge is clean enough to prevent
benzene contamination. Next the dockside operator must connect
the hose to the dock manifold. Last the barge operator connects
the hose to the barge manifold and "lines up" the barge compart-
ments by opening the correct valves. Initially the benzene is
p-ar.mit-t.ed—to gravitate from the tanks to the barge before the
pumps are switched on. The normal flowrate for barge loading
pumps is 2,000 gpm and two 100/S pumps are provided. The loading
is monitored by the barge operator who observes either the level
in the compartments by inserting dipsticks through the ullage
hatches above each compartment (the usual manner) or (less
often) by observing the draft of the barge. Observation of the
draft limit is practiced when barges must be sent through shallow
channels. Benzene vapor is expelled from the barge through the
ullage hatches during loading. It is assumed that any ship
20
-------
Loading will be done from the barge dock. It is estimated in the
United States only a small amount of benzene is loaded onto
ships. The United States is a net importer of benzene. As of
1972 estimates, 25 million gallons were exported compared with
imports of 125 million gallons and total consumption of 1,282
million gallons. None of the plants visited loaded benzene onto
ships.
Sources of benzene emissions for the base case producer have been
divided into three general categories for convenience. These
categories are storage tank losses, loading losses, and miscel-
laneous losses. Storage tank (floating roof) losses can be sub-
divided further into standing losses and withdrawal losses.
Standing losses are due to liquid benzene evaporating past the
perimeter roof seals. Withdrawal losses occur as the tank is
drawn down. All losses are calculated according to the emission
factors per SPA publication "Compilation of Air Pollutant
Emission Factors, Supplement Number 7," April 1977. New calcu-
lation methods are being developed by others but were not used
because a standard and widely known method was desireable. It is
recognized that the methods used for calculating losses may lead
to larger than observed losses. The losses are tabulated in
Table 4.2.1.
Loading losses are produced as liquid benzene is pumped into the
carriers and the benzene vapors are displaced. These losses are
also tabulated in Table 4.2.1 for barge, truck, and railcar
transports. These vapor losses have two components". One
component is the existent vapor in the tanker resulting from
previous cargoes. The second component is that benzene vapor
generated during loading. It has been assumed that empty tankers
have not been cleaned or degassed and contain vapors from
previous benzene hauls. The vapor emitted from railcar and
21
-------
TABLE 4.2.1
Benzene Emissions
Inventory for Producer Base Case
Storage Losses. (Ib/yr)
Rundown Tanks Railcar-Truck Barge Tanks
Tanks
Standing Loss 5,600 10,200 12,100
Withdrawal Loss 5,100 2,200 800
Subtotal 10,700 12,400 12,900
Total Storage Losses: 36,000
Loading Losses (Ib/yr)
Rail/car Truck Barge
28,900 11,600 28,900
Total Loading Losses: 69,400
Total Plant Losses (Ib/yr): 105,400
22
-------
trucks is assumed to be 60* saturated by benzene. Barge vapor is
assumed to be 50* saturated.
Miscellaneous losses include "fugitive" losses and transit
losses. Fugitive losses have been defined as those losses
occuring from poorly sealed and leaking pipelines, flanges, and
pumps. These losses have been calculated by the application of
SPA emission factors for refinery hydrocarbon losses (from these
sources in their uncontrolled state) to the benzene producers.
It has been assumed that all hydrocarbon losses are benzene and
that the emission factor is transferable to a benzene producer
per se. Transit losses have been defined as benzene los-t- by
carrier vessels "breathing" out benzene vapors as atmospheric
conditions cause the pressure settings of the pressure-vacuum
relief valves to be exceeded. While this applies to all types of
carriers, it has been suggested that due to the short travel time
of railcar and truck shipments (under two days) no transit losses
occur, and therefore only barges (with longer travel times) are
likely to show significant transit losses. It has been assumed
that average barge shipments must travel one week to their desti-
nation. These losses seem unduly high in our opinion if transit
losses are to be attributed to breathing losses. The pressure
settings on railcars ana trucks are higher than any pressure
buildup that could reasonably be expected to occur through normal
changes_in_ atmospheric conditions. Relief valve pressure set-
tings for these carriers are on the order of tens of psig. Pres-
sure settings for barge relief valves are approximately 1.1 psig.
The pressure build up for a daily 30°F temperature rise (70° to
100°) for an ideal gas initially at atmospheric pressure is ap-
proximately 0.3 psig. By comparing the pounds of benzene transit
losses with the corresponding outbreathing volume for a week long
barge trip it is found that the results do not agree with each
other. (The expelled vapor would be supersaturated.)
23
-------
Control technologies have not been applied to the fugitive losses
because these non-point sources are more related to general plant
housekeeping and not within the scope of our report. Transit loss
control has not been pursued because calculations indicate that
losses as defined and calculated by the stated guidelines are
contrary to the actual situation, and that actual quantity of
transit losses are much lower.
4.2.2 Benzene Consumers
The base case consumers are shown in Figure 4.2.2. The basic
principles of receiving and storage for the two consumers is the
same. The benzene is accepted from the transports and sent
directly to floating roof, double seal, welded shell storage
tanks prior to final consumption. The major differences deal
with the method of transport and quantities of benzene handled.
The large benzene consumer receives its feedstock by barge and
pipeline. Total consumption is 26 'million gallons per year or an
average of 50 gpm. Of this volume 12 million gallons is de-
livered by barges and 14 million gallons is delivered by pipe-
line. The barges are unloaded at 2,000 gpm into two storage
tanks. The storage tanks have a working capacity of 420,000
gallons, the diameter is 42 feet and the height is 48 feet. The
bejizejie-enter ing the pilot plant by pipeline is stored in the
same tanks. The pipeline flowrate is 26 gpm and is continuous.
The small benzene consumer receives feedstock by railcar and tank
truck at a rate of 14 million gallons per year. Of this volume 10
million gallons arrive by railcar and 4 million gallons arrive by
tank truck. The tankers are unloaded at 325 gpm. The benzene is
stored in two 125,000 gallon (net working capacity) storage tanks.
The tank diameter is 25 feet and the height is 48 feet. The
benzene is withdrawn from the tanks at an average rate of 26 gpm.
24
-------
2000 (1PM
I2MM GAI /YR
.2OOO GPM | **»-
HARGE-28/YEAR
420,000 GALLON EACH
IKANSI'FR
8"HOSE
MMM GAL/YR
?fe GPM
LARC.F ('.ONSOMLR
50 GPM r—=
50" GPM
TO
PLANT
50~GPM
2 BARGi: PIPELINE
Rt CUV ING TANKS
120,000 GALLONS EACH
fl'x'0 X. 18'
L
~l
)
OO OO I"*"1* — "
KAILCAH-bOO/YEAN
20,000 GALLON EACH
1 -r
(
)ri
I4MM fiAL/YR
fc 3 SO GPM
3bO GPM
tju u *o-cy *~*^1 — •*
IANK TRUCK- !<00/ YEAR
-~]
i i
_
;
SMALL CONSUMER
, ?6 GPM to 1
(^ * PI ANT \
26~GPM
2 6" GPM
UOOO GALLON EACH
2 IVAILCAR-TANK TRUCK
RECEIVING TANKS ,
I20.0OO GALLON1-, EACH
20'0 X -JO' ;
FIGURE 4.2.2 BASE CASE #6 - BENZENE'CONSUMERS
-------
The two major categories of benzene losses are storage tank
losses and miscellaneous losses. Storage tank losses are
tabulated for each case in Table 4.2.2. Miscellaneous losses can
be reduced by general plant housekeeping and their control will
not be discussed further.
26
-------
TABLE 4.2.2
Benzene Emissions Inventory for
Consumers Base Case'
Standing Loss Withdrawal Loss
Large Consumer
Tankaae Losses 10,213 2,013
(Ib/yr)
Small Consumer
•Tankage Losses 4,690 1,821
(Ib/yr)
Total Losses 18,737
(Ib/yr)
27
-------
4.3 APPLICATION OF CONTROL TECHNOLOGIES TO BASE CASES
4.3.1 Producer Cases
As stated earlier in Section 4.2.1, the sources of benzene
emissions from benzene producers were divided into three
categories, storage tank losses, loading losses, and miscellane-
ous losses. Miscellaneous losses can be subdivided further into
two sources, fugitive losses and transit losses. Control techno-
logies have not been applied to fugitive losses because these
non-point sources are more related to general inplant housekeep-
ing and not within the scope of this report. Gas flow rates are
given in gpm by vendors, and this convention has been followed in
the report.
4.3.1.1 Case Number Two - First Level of Control
The first level of controls over the base case is depicted as
shown in Figure 4.3.1.1 for Case Number Two. Case Number Two
involves the reduction of storage tank losses by adding cone
roofs and reducing loading losses by adding vapor recovery units
to treat collected vapors. The addition of cone roofs with lou-
vers to allow air to circulate between the fixed and floating
roofs are expected to reduce standing losses by 48J. Withdrawal
l.QS.se.SL—ar.e. considered unchanged. Loading losses are collected as
they exit the carrier vessels and transported to the vapor re-
covery units. Railcar and truck loading require some modifica-
tions to both the loading arms and the carrier tanks. Special
fittings are required to attach the vapor collection hoses to the
loading arms. The vapor hoses are mounted piggyback fashion on
the arms. The driving force to transport the vapor through the
collection- system to the recovery unit is provided by liquid
benzene displacing vapors as tanks are filled. Vapor collection
28
-------
UN!
S
40MMGAL/YR*
7ti GPM
-XI
I_JL J
IXl—i
LJL.J
2 RUNDOWN ANKS
12 5000 (,AL. tACH
25'0 X 40'
IO
AIM
I
I
I VAI'i
' IRIXOV
[ i in
'OH
ovrnv
nun
-HSI--
28 MM
(iAI./YRj
Mi—iL^Kj
265 GPM
350 <;\>M
(j'jII/IIR
BENZENE
—IXJ
a
to
10
2 RAII.CAR-IANK TftUCK 350GPM
SHIPPING TANKS
12 MM GAL/fR
265 GPM—.
350GPM
Xt—i
26 GPM
foQ)
26 GPM
I...I LJ
FIG. 4.5.1
10 MM GAL/YR ' 1 '
350 GPM ,
uo
R.R.CAR
2QPOOGALEACH
| FIG. 4.5.1 |
4 MM GAL/YR I
350J3PM rtx»E3-J
UCT
TANK TRUCK
8000 GAL EACH
PIPELINE!
FRANSFERl
TO
ATM
I
•A I'OH I '
ilOVtRTi--1
UNIT I
VAI
RECOV
UNI
2 BLOWERS
2000 GPM ..
AP=2 PSIG ^-t'SI ART
2000 U'M
300H/HH
OENZENE
2 DARfir MlirPING TANKS r,,\n*»™»
(.30,000 JJAL ( ACII 20000.PM
* X bt> i
420,000 GAL BARGE
FIGURE 4.3.1.1 CONTROL CASE #2 - BENZENE PRODUCER
-------
for a barge requires the common manifolding of the ullage hatches
or pressure vacuum relief lines to permit the attachment of a
collection hose. The onshore portion of the collection system
requires blowers to transport the vapor to treatment. This is
necessary because the required pressure exceeds the design pres-
sure of barges. The blowers have been sized to match the benzene
fill rate, and a 100* spare blower is provided.
Saturators are incorporated into" the collection system as close
to the carrier as possible. The detail of the saturator is shown
in Figure 4.5.1. The saturators cascade benzene in a tower
through which the collected vapor is passed to saturate the vapor
with benzene and raise the concentration above the upper explo-
sive limit. This step greatly reduces the possibility of fire or
explosion in the collection system by ensuring that the vapor is
over rich. The vapor recovery units are designed to operate only
during loading operations. Two units are used, one to handle
railcar and truck losses, the other to handle barge losses.
Three types of technology, refrigeration-absorption, carbon
adsorption, and thermal incineration are used for vapor recovery
and these are discussed in Section 4.1.
4.3.1.2 Case Number Three (See Figure 4.3.1.2)
Three maintains the same control schemes as Case
Number Two for vapor recovery of loading losses. For storage
tank losses, however, a more elaborate control scheme is used.
The floating tanks are covered with cone roofs and pressure-
vacuum vent valves installed. The vapor space is blanketed by
..... ' 3
nitrogen gas and regulated by pressure control to admit N during
inbreathing by the tank.
Vapors are collected and transferred by blowers to the recovery
units. One hundred percent capacity spare blowers are provided
30
-------
10
AIM
7\ ' I VAPOR i
y HRLUM HY , '
I L_ UlllI . J * i
--C3-
_ _
100 GPM
MI/I II)
40 MM GAL/YR^
7fa GI'M
PSIG C.AI./YH
®**
?t,bGI'M
26i) GPM
I
FA$
J JiPV
Utr'N2
2 RAII CAR-TANK TRUCK
SKIPPING TANKS
420,000 GAL LACH
42'0 X 48'
12 MM GAL/YR
26b GPM-J
2 RUMUO'WN TANKS
I25.00O GAL EACH
2b'0 X 10'
261 GPM
IO»«/HR
1'SIAHT
STOP
GPM
r2 PSIG
3bOCPM
£5^
350GPM
10 MM GAI./YR
300 GPM
UO IXJ
R.R.CAR 4
20.000GAL EACH I r,G ^ c,,
A MM GAL/YR
3bO GPM
-txi
cr
TANK TRUCK
8000 GAL EACH
2 BLOWERS
2OOOGPM
AP=2 PSIG
2000 GPM
300H/Mf)
BENZENE
12 MM GAL/YR
8"HOSE-
2 FIARGt SKIPPING TANKS o7^nnn«
GJO.OOO.JjiAL VACII 20000PM
START
' X
LS10P4"HOSE]
\ FIG. 4.b.r|fr(
•APV
4 2 O.OOO GAL BARGE
FIGURE 4.3.1.2 CONTROL CASE «3 - BENZENE PRODUCER
-------
in this service. The blowers are controlled by a pressure switch
sensing pressure buildup as liquid flows to each tank, thus the
blowers start as liquid benzene enters the tank and stop when
liquid flow stops. All pieces of equipment are isolated by water
seals and/or flame arresters for safety reasons. Carbon adsorp-
tion, thermal incineration, and refrigeration-adsorption
technologies are used for vapor recovery and are further
discussed in Section. 4 .1.
4.3.1.3 Case Number Four (See Figure 4-3.1.3)
Case Number Four utilizes vapor balance to reduce the number of
vapor recovery units required. In a vapor balance system, the
liquid transferred from a tank to a carrier displaces vapor from
the carrier which is returned to the vapor space of the tank.
Vapor displaced from the tank during liquid fill can be sent to
treatment or displaced to another tank in a vapor balance system.
Blowers to transfer vapors from tanks are controlled by pressure
switches. The collection systems from the carriers include
saturators to maintain the vapors above the upper explosive
range. Nitrogen blanketing is used on the storage tank vapors to
reduce the possibility of explosive mixtures. Breathing losses
are not treated because the turndown capability of the collection
and vapor recovery units do not permit it. The control
tec.hnoJL.ogj.es of refrigeration-adsorption, carbon adsorption and
thermal incineration to be used are covered in Section 4.1.
4.3.1.4 Case Number Five (See Figure 4.3.1-4)
Case Number Five is very similar to Case Number Four except that
the use of vapor holders is. introduced to reduce the breathing
losses by capturing them for treatment. The vapor holder is a
tank containing a flexible diaphragm which adjusts according to
the volume of vapor stored. Vapor holders are installed in the
32
-------
LJ
10
10 MM GAl./YR
350 GPM
2 UIOWI.KS
,'?b'j<,l'M 20 MM
IOH/HR
I PRODUCTION]
I UNIT
40MMGAL/YR
76 GPM
I
FA$
,1-txl | | *4-J- •TT|xlf3^
AII.CAR-TAMK I MUCK I 350GP
SHIPPING TANKS .
20,000 GAL EACH Itxi-fTF
420,000
42'0 X 48'
TANK TRUCK
8000 GAL EACH
12 MM GAL/YR
GPM-..
I25LOOPOAL tACH
2f>'0 X '
GST1 WTOs LSIOP
200"OGPM 8'HOSE
ril^2^boPM 420,(K)0 GAL BARGE
r^x"56"
FIGURE 4.3.1.3 CONTROL CASE «4 - BENZENE PRODUCER.
-------
Co
VAPOR HOLOER
NETCAP=I0,OOOGAL
!START
r"
I
2 BLOWERS
100 GPM
AP-2 PSIG
HOLDER
NET CAP=40.000 GAL
FA .-< •--
I*5T~"»
10 MM GAL/YR
350 GPM
I F'G.«.5.l|
2 BLOWERS
265 GPM
AP=2PSIG
40 MM GAL/YR^
76 GPM
RAILCAR-TANK TRUCK
SHIPPING TANKS
420,000 GAL EACH
42'0 X 48'
2 RUN
TANKS
125000 GAL EACH
25'0 X 40'
12 MM GAL/YR
265 GPM—.
VAPOR HOLOER
NET CAP
=30.000 GAL
350GPM
ou
R.R.CAR
2QPOOGALEACH[-F|G-^5||
4 MM GAL/YR '
350 GPM
265 GPM
50 *VHR
LOWERS
265 GPM
AP-2 PSIG
OU D
TANK TRUCK
8000 GAL EA.CH
2 BLOWERS
2000 GPM
AP=2 PSIG
8"HOSE
20000PM
420,000 GAL BARGE
FIGURE 4.3.1.4 - CONTROL CASE #5 - BENZENE PRODUCER
-------
vapor lines out of the storage tanks to receive outbreathing
losses throughout the day. If the capacity of the vapor holder
is not exceeded by the end of the day, then the same vapor can be
usei for night time inbreathing volume thereby reducing nitrogen
usage. When the capacity of the vapor holder is exceeded,
however, the excess vapor is drawn off by a blower and sent to
the vapor recovery unit. The starting of the blowers can be
controlled either by pressure switch- in the vapor holder OF--by
sensing the position of the vapor holder diaphragm. Control
technologies to be used in Case Number Four are discussed in
Section 4.1.
4.3.2 Consumer Cases
The benzene consumer base case is described in 4.2.2 and is re-
ferred to as Case Six. (See Figure 4.2.2.) The first degree of
vapor emission reduction is referred to as Case Seven. (See
Figure 4.3.2.1). The second degree of control is Case Sight.
4.3.2.1 Case Number Seven
4.3.2.1.1 Large Consumer
The addition to the base case is retro-fit covered floating roof
tanks. This reduces the tank emissions approximately 40* below
Case Six by lowering the average wind velocity across the roof.
Louvers are placed in the top of the tank wall above the floating
roof to allow ventilation. This is done to prevent an explosive
vapor mixture from accumulating in the tank top. When the barge
c-argo is pumped into the tank at 2,000 gpm, the roof rises and
the vapors are displaced to atmosphere through the louvers. Dur-
ing the daily usage of benzene at 50 gpm, air is drawn in through
"he louvers. The sane exchange of vapors accures when the pipe-
line fills the tanx: at 25 gpm.
35
-------
2000 GPM ! I2M2000LGPM| 1*»-
N^ ,. , , _
BARGE-28/Y
420,000 GALLOr
fe} " ViJ ,i "„
I/
? EACH
I4MM GAL/YR
PIPELINE I ^b GPM
K^l^_
TRANSFER 1 t ^1
,LJLJ7
^
;
i
, 50 GPM
50 GPM
. r ^ LARGE CONSUMER
30 GPM "TO '1
PLANT 1
2 BARGE PIPELINE
RECEIVING TANKS
420,000 GALLONS EACH
42'0 X 48'
UJ
OU OO
RAILCAR-500/YEAR
20,000 GALLON EACH
CO
TANK TRUCK- 500/ YEAR
8000 GALLON EACH
l-fa
txj
I4MM GAL/YR
350GPM
350 GPM
SMALL CONSUMER
..26 GPM.
X
26 GPM
TO
PLANT
2 RAILCAR-TANK TRUCK
RECEIVING TANKS
125,000 GALLONS EACH
25'0 X 40'
FIGURE 4.3.2.1 CONTROL CASE #7 - BENZENE CONSUMERS
-------
4.3.2.1.2 Small Consumer
The small consumer uses retro-fit covered floating roof tanks
with louvers and the tank emissions are reduced approximately 35*
below Case Six by lowering the average wind velocity across the
roof. The operation is similar to the large consumer except that
flowrate from the railcar/truck pumps is 350 gpm and the daily
usage rate is 26 gpm.
»
The safety of the consumer base Case Six is not lowered by Case
Seven technology. This first stage of reduction in benzene emis-
sion is relatively simple in concept and requires little addi-
tional operating expense. The reduction in emissions is shown in
Table 4.4. 1 .1.
4.3.2.2 Case Number Eight
The second degree of vapor emission reduction is referred to as
Case Eignt. (See Figure 4.3.2.2.) Case Eight is divided into
the large and small consumer. The large consumer will be dis-
cussed first.
4.3.2.2.1 Large Consumer
The equipment additions to the base case are retro-fit covered
floating roof tank, nitrogen inerting, a vapor holder, blower,
and three types of vapor treatment units.
The-tanks are not provided with louvers in Case Eight, instead
they are fitted with pressure-vacuum vents to prevent benzene
vapor from entering the atmosphere. Nitrogen is used to blanket
an- inert the tank vapor space to prevent an explosive mixture.
As liquid is removed from the tank, nitrogen is bleed in. A.s
37
-------
00
\ r---r
/•
N2 >
T <-* ™
All VAPOI
e^^^. WT C
9nnnruu I2MM CAL/YR [, 1 «ib,0(
2000 GPM __ 2000 GPM| txJ" &ij
f r.i i f i
k|4 V .,
. 1 — .__ ^ Q nn^r
-~1--| / Np
BARGE-28/YEAR Tr-o— \
420,000 GALLON EACH pv|jl f FA
I4MM GAL/YR J^~^
1 PIPELINE 1 i!b GPM i 1
LlRANSFER 1 t ^ -cxi J
^ J LS10P
\J^ 1 iriAjri. -^
"™ ^ ^ ^ -l^" t Jf If if "Ifcjj" ^~ *tv
"— — ~— - FA AI\ FA 1 1
TO
ATM
kPOR !
JVLHY - '
NIT
< HOLDER | BLOWER jnnn'ri'tJ
APACIIY 5nr»nrt>M 2000 Gi'M
10 G A 19,°°^ GrA i 7 5 ll/ 1 1 R
JU 1>AL Ap=2 PSI BENZENE
LARGE CONSUMER
50 GPM J ' TO
fa) " '1 PLANT
, 50 GPM
-§T
50 GPM
2 EARGE PIPELINE
RECEIVING TANKS
420,000 GALLONS EACH ^H5TART
4>'0 X 48' ' \$) 1
N2 ! LST°P
(
O'.i C
RAILCAR-
20,000 GA
(
k,
r- -^M^r?5: -^
^ — . —
IO P ____jvxt
5OO/YFAR f IX>'" "*'' 1
LLON EACH MMM (jAL/YR
M 3bOGPM
-^ N2
r^^^-^-.. 3bOGPM TI-O-* '
1 ' FA
PVlill 1
Jl 1 .^, . Ml
b GPM I TO
/^Y^ 1 PLANT
26 GPM
26 GPM
8000 GALLON EACH
2 RAILCAR-TANK TRUCK
RECEIVING TANKS
I2!J,OOO GALLONS EACH
2'V0 X 40'
FIGURE 4.3.2.2 CONTROL CASE #8 - BENZENE CONSUMERS
-------
heading occurs and the tank vapors expand, the nitrogen-benzene
vapor mixture flows to the vapor holder. A 40,000 gallon (5,350
ft3) vapor holder is used with the large consumer. Day to day
breathing Jue to temperature change is accomodated by passage to
and from the vapor holder. Two sources of tank filling are
handled as follows:
(1) When a barge is unloaded every 23 days at 2,000 gpra for 3.5
hours; the pressure in the tank vapor space and vapor holder
rises and a pressure switch starts the blower. The vapors flow
to the treatment unit. After the barge is unloaded, the blower
continues to run until the vapor holder is emptied and then shuts
down.
(2) As the pipeline fills the tank at 26 gpm continousl'y"," t'he
displaced vapors flow in to the vapor holder. When the vapor
holder is full and the pressure rises; the blower is cut on and
the pressure rises; the blower is cut on and pumps to the treat-
ment unit.
A flaae arrester is installed in the piping between the storage
tank vapor space and the vapor holder. The piping on either side
of the blower has a flame arrester and water seal. Each treat-
ment unit has a flame arrester and water seal upstream. All of
this is done to prevent any accidental explosion from propagating
to other parts of the system. The vapors are monitored in the
blower upstream piping to assure that a non-explosive mixture
does not exists and when a hazard is present, neither the blowers
nor the treatment system is allowed to work. The sequence of
operation is start treatment unit, start barge pump, the blower
starts as the pressure rises. Should the blower remain on too
lon-g, the vacuum vents are sized to pass the full 2,000 gpm air
flow. The only emission to atmosphere is in the treatment unit
tail gas. See Table 4.4.1.2 for emission data.
39
-------
4.3.2.2.2 Small Consumer
The small consumer utilizes equipment additions to the base case
that consist of retro-fit covered floating roof tanks, nitrogen
inerting, blower and one of the three types of vapor treatment
units. The tanks are not provided with louvers, but use pres-
sure-vacuum vents. Nitrogen is used to inert as discussed above.
Day to day breathing due to temperature change is vented to the
atmosphere. When the tank is filled from a railcar or tank truck
at 350 gpm, the pressure rise turns on the blower and the vapor
is pumped through the treatment unit. An interlock system
differentiates between a pressure rise due to breathing and that
due to tank filling. When the vapor flow stops, the blower turns
off. Breathing losses are expected to be low because the benzene
liquid withdrawal rate is approximately equal to the daytime
breathing rate.
The precautions are the same as for the large consumer. The
reduction in emissions is shown in Table 4.4.1.2.
40
-------
4.4 EMISSIONS
For a complete assessment of emissions when applying control
technologies, one must consider both primary emissions (benzene)
and secondary emissions (those non-benzene emissions produced as
a result of controlling benzene emissions). In the present
discussion the evaluation of primary emissions will entail a
summary of benzene losses for each case, the basis for calcula-
tions of losses, and the calculated emission factors. The
emission factors will allow a means of comparing control effec-
tiveness for the different cases. Secondary emissions will
receive a less quantitative approach and will center mostly on an
inventory discussion.
4.U.I Primary Emissions
Only two major categories of benzene losses will be discussed;
storage losses and loading losses. Fugitive losses will not be
addressed because they are not considered within the scope of the
study.
Losses from open floating roof storage tanks are subdivided into
standing and withdrawal components. Methods for calculating
these losses are abstracted from EPA emission factors. When
c_p_v er_e_d „ f 1 o a t i n g roof tanks with louvers are considered, the
standing losses are reduced because although the same equation is
used, a credit for reduced wind speed from 10 mph to a suggested
^ mph is permitted. The reasoning for the reduction in wind
speed is that freedom of air movement circulating between the two
rob'fs is reduced. When covered floating roof tanks without
louvers are considered, the characteristics of benzene emissions
are changed. This type of loss is considered to occur by out-
breatning by the pressure /acuum vents, the problem is calcula-
ting the volume ani benzene concentration of the vapor lost.
-------
Several assumptions to facilitate this calculation are made and
are discussed below:
1) The vapor mixture behaves as an ideal gas as tempera-
ture experiences a daily cycle in the vapor space of
the tanks. The temperature increase is from 70°F to
100°F and barometric pressure is constant.
2) The benzene vapor in the mixture is derived from three
sources; standing losses, withdrawal losses, and any
additional benzene returned to the tank via vapor
balance sources.
3) An average benzene concentration is calculated by
dividing the benzene losses by the vapor volume
expelled from the tank.
For those cases that a vapor holder is incorporated the breathing
losses have ben assumed to be reduced by 90/6 from the non-vapor
holder case.
The calculation of loading losses is complicated by the addition
of vapor recovery systems. The effects of benzene saturators,
efficiencies of the collection-treatment systems, intermingling
of the loading and storage losses by vapor return must be
accounted for. When benzene vapors are recovered from a carrier
in the explosive range, benzene must be added to bring the
C-oncen-tr-a-tion up to saturation and therefore out of the explosive
range. The quantity of benzene that can be potentially lost is
greater than just the loading loss.
There are some losses associated with the collection systems from
poor connections, leaks, faulty operation, etc. Finally, because
the vapor treatment units are not 100? effective, there is still
some small-amount of benzene that escapes untreated.
-------
4.4.1.1 Case Number One
A discussion of primary losses for the base case has been
presented in Section 4.2.1 and will not be repeated here.
4.4.1.2 Case Number Two
For Case Number Two the calculation of storage losses is straight
forward for the covered floating roof tanks. Standing losses for
the covered floating roof tanks are calculated with the same
equation as an open floating roof except that the wind speed used
is - mph rather than 10 mph. Withdrawal losses are._.un.cJian3-sd
because wind speed is not a factor. Storage tank losses are
tabulated in Table 4.4.1.1.
Loading loss calculations are best illustrated by an example.
The example used here is barge loading loss. The barge is loaded
at 2000 gpm with liquid benzene at S5°F and 25 psig. The
emission factor for these conditions is 2.41 lb/10 gallons
loaded. Since this vapor stream is not saturated, 2.41 lb/13J
gallons benzene must be added in the saturator to comply with
safety goals. This additional benzene becomes susceptible to
loss downstream in the treatment system. The total amount of
benzene entering the collection system is 57,900 pounds. The
c^oi-1-ec-t-io-n system is assumed to have an efficiency of 93', thus
the benzene reaching the treatment unit is 56,700 pounds, and
1,200 pounds is lost to the atmosphere. Efficiencies for the
vapor treatment units are based on vendor reported emission
levels and saturated benzene- air mixtures. For the
refrigeration-absorption system, the benzene recovered is 56,400
pounds and the benzene released to atmosphere is 300 pounds. The
calculated emission factor for carbon adsorption or th'ermal
oxidation is .684 lb/103 .gallons of benzene produced. For
-------
TAIU.K -1.4.1 .1
Dcnuono l-'.mir.sions Summary For nctinenc Prcxlucnr Control Cases
TrcMUnonl unit
Technology
db/yr)
Collection
Ins-ier, (Ib/yr)
1,05' n-, Throuqh
Tri'.ilm"nt Units
(Ib/yr)
Total System Losses
A
Rcfriqeration
Absorption
22,809
4,531
664
28 , 004
2
B
Carbon
Adsorption
22,809
4,531
12
27,352
3
C ABC
Thermal
Incineration
22,809 2,874 2,874 2,874
4,531 4,929 4,929 4,929
156 734 14 1H2
2,7,496 8,537 7,817 7,985
4 5
A 3 C ABC
26,082 26,082 26,082 2,608 2,M)B 2,608
8,067 8,007 8,067 8,746 8,746 R.746
009 11 143 752 14 1»2
34,758 34,160 34,292 12,106 11,368 11,536
(Ib/yr)
tpollution From Base
Cms". »l 73.4
74.1
73.9
91.9 92.6 92.4
67.0 67.6 67.5 88.5 89.2 89.1
-------
refrigeration-absorption it is .700 lb/103 gallons. The factor
for thermal incineration is .63? lb/103 gallons.
4.4.1.3 Case Number Three
In Case #3 the covered floating roof tanks are not equipped with
louvers. The benzene vapor which evaporates remains in the space
between the two roofs and is emitted by breathing, or when the
tank is filled with liquid and the roof rises. No attempt is
made to capture or treat breathing losses. Vapor expelled during
tank filling is handled by a vapor treatment system dedicated for
each set of tanks. Loading losses for Case #3 are unchanged_f-r-om-
Case #2. A Summary of Case #3 losses is shown in Table 4.4.1.1
The emission factor for Case Number Three is .195 lb/103 gallons
produced for thermal oxidation or carbon adsorption, and .213
lb/103 gallons for refrigeration absorption, and .200 lb/10
gallons for thermal incineration.
4.4.1.4 Case Number Four
Calculations of losses for Case #4 are complicated by the mixing
of loading losses and storage losses, as loading vapors are
saturated and returned to the vapor space of the tanks. Thus the
vapors lost from tank vapor spaces are richer in benzene. This
cau_ses_Jbhe___breathing loss from tanks to increase. Losses for
Case #4 are tabulated in Table 4.4.1.1. The emission factor is
.354 lb/10 gallons for carbon adsorption, .869 lb/10 gallons
for refrigeration absorption, and .857 lb/10 gallons for thermal
incineration.
4.4.1.5 Case Number Five
Case -'5 is identical to Case #4 except for the addition of vapor
r.-liers to provide surge capacity to contain breathing losses.
-------
Thus the losses for Case #5 are similar to Case #4 except that
breathing losses are drastically reduced. Case #5 losses are
shown in Table 4.4.1.1. The emission factor for Case #5 is .284
3 •*
lb/10 gallons for carbon adsorption, .303 lb/10 gallons for
refrigeration absorption, and .288 lb/103 gallons for thermal
incineration.
4.4.1.6 Case Number Six
A discussion of primary emissions for the base case is presented
in Section 4.2.2 and will not be repeated here.
•
4.4.1.7 Case Number Seven
Case #7 represents the first control case for the benzene con-
sumers. The method used to reduce benzene emissions from tankage
is to cover the floating roof tanks. This step reduces the
standing losses^. Emissions for Case #7 are presented in Table
4.4.1.2. The emission factor for this case is .287 lb/103
gallons.
4.4.1.8 Case Number Eight
Case #8 uses covered floating roof tanks blanketed by N and
va~por" "Treatment units to reduce emissions. The large consumer
utilizes a vapor holder in addition to the other measures to
further reduce breathing losses. Table 4.4.1.2 lists the
results. The emission factor for Case #8 is .027 lb/103 gallon
for~carbon adsorption and thermal incineration technologies and
.028 lb/10 3 gallons for refrigeration absorption.
46
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TABLE 4.4.1.2
Benzene Emissions Summary For
Benzene Consumer Control Cases
Case Number
Treatment
Ur.it
None
Required
11,432
Technciocv
(Ib/vr)
Tankage
Losses
do yr)
Collection 0
Losses
(Ib/yr)
Losses 0
Through
Treatment
Units
(Ib/yrJ
Total System 11,432
Losses
% Reduction
Frcn Base
Case =?6
38.7
8
Refrigeration
Absorption
853
217
59
1,129
94
8
Carbon
Adsorption
853
217
1
1,071
94.3
8
Ther.-r.al
Incineratic
853
J. J
1,OS3
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4.4.2 Secondary Emissions
The three types of secondary emissions (solid, liquid and
gaseous) for each of the control technologies are discussed in
the following sections.
4.4.2.1 Solid Emissions
It is unlikely that either the refrigeration-absorption or
thermal incineration systems will generate any significant waste
solids. Carbon adsorption will lose some small amount of carbon
dust during normal operations. This dust is produced as the
carbon granules abrade against each other and escapes through the
support medium and out the vapor exit. At the end of the carbon
bed's useful lifetime the entire carbon bed must be replaced with
new carbon. This carbon will still have some small residual
benzene along with other hydrocarbon based impurities not
previously desorbed.
4.4.2.2 Liquid Emissions
One source of liquid wastes common to each technology is benzene
contaminated water in the many water seals. The magnitude of
this pollution is considered relatively small, the equilibrium
canjC-e-n-tr-ation of benzene in water (§ 100°F, 1 atm.) is
approximately 30 mg/1. An overflow rate of .5 gpm per seal is
necessary to insure safety. Liquid emissions for thermal
oxidation, neglecting water seals, is zero. Refrigeration-
absorption and carbon adsorption technologies both have
condensers which condense benzene and atmospheric water vapor.
The water must be drawn off in a decanting separator and
disposed. The condensers of the refrigeration-absorption system
will also condense some diesel oil out with the benzene and
water.
48
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^.1.2.3 Gaseous Emissions
'.Io secondary gaseous emissions are anticipated from the carbon
adsorption systems. Diesel vapors may be released from the
refrigeration absorption systems, but the expected level is low
due to the low volatility of diesel oil. The thermal incinera-
tion systems will be the largest generator of secondary gaseous
emissions. The gaseous emissions from thermal incineration are
the normal combustion products, and include NO , CO, and unburned
X
hydrocarbons. If fuel oil is used instead of natural gas, SO
A
will be produced also.
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4.5 OPERATION OF CONTROL SYSTEMS
4.5.1 Safety
4.5.1.1 General Discussion
Safety is always of paramount importance when designing equipment
to handle flamable materials. It is necessary that systems added
to reduce benzene emissions not introduce significant fire and
explosion hazards. Vapors vented to atmosphere from carriers and
storage tanks quickly dilute to a concentration below the lower
explosion limit. When vapors are collected and piped to a dis-
posal or recovery unit, the danger of an explosion is more pre-
valent because the vapor concentration is in, or close to, the
explosive range. The safety hazard increases as more machinery
is required to handle explosive vapors and as longer piping runs
are required. A partial listing of ignition sources includes:
(1) Static electrical sparks, (2) Sparks or hot spots created by
machinery such as blowers or vapor pumps, (3) External damage to
piping which causes leakage along with a spark or hot surface,
(4) Flash back from flame in vapor incinerators.
When applying vapor control systems to benzene facilities, means
must be found to Ca) prevent explosive vapor mixtures, (b) reduce
igui.tLon -sources, (c) isolate systems so that flame fronts will
not travel through whole systems.
•
4.5.1.2 Case Studies
All case studies required that special systems be provided to
prevent undue explosion hazards. The intent has been to design
benzene vapor control systems that can be added to exis-ting ben-
zene transfer facilities so that the potential for an explosion
for the modified facility will not have increased. The following
50
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special systems and features were incorporated in the designs and
included in the estimates for the study cases:
4.5.1.2.1 Cases 2, 3. 3» 4 - Benzene Saturator
(See Figure 4.5.1)
The vapors from the carriers to the storage tanks or treatment
units are made safe by saturation-with benzene. A benz-e-ne
saturator is used in Cases 2, 3, 4 and 5 in association with
barges, railcars and tank trucks. The purpose of the saturator
is tc increase the benzene concentration of the benzene-air
aixture and therefore avoid an explosive mixture. The saturato_r
consists of a pressure vessel, spray nozzel , heat exchanger,
recycle pump, demister pad and control devices to maintain a con-
stant liquid level and to shut down the pump if the level gets
too low. A no flow switch shuts off the heat exchanger. A vent
pipe is attached to the saturator such that an over pressure and
under pressure can be handled at the carriers loading pump design
flow rate (2,000 gpm for barges, 350 gpm for railcars and tank
trucks).
4.5.1.2.2 Cases 3, 4, 5 - Nitrogen Inerting
A nitrogen inerting system is used in cases 3, 4, and 5 in
ass.qciatlojj with vapors stored or generated in the vapor space
above the covered floating roof tanks. The purpose of the nitro-
gen is tc lower the oxygen content to below 5% volume, and
therefore, avoid an expl'osive mixture. The nitrogen system
consists of a storage tank of liquid nitrogen, a vaporizer, and
pressure control valves to maintain the pressure in the benzene-
nitroger. mixture to a positive level, but below the pressure
setting of the pressure-vacuum vent.
51
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VAPOR SAIUUATOR
TO
.NSI
LINE
TRANSFER^ rFlJSALURATED VAPOR)
FLOW SV/ITCH
TEMP SWITCH
r
ELECTRIC
HEATER
(LEAN VAPOR)
$FROM VAPOR
SOURCE
RE-CYCLE
PUMP
LIQUID MAKEUP
^CONTROL VALVE
FIGURE 4.5.1 BENZENE VAPOR SATURATOR
-------
Therefore, because the vapors above a floating roof tank would be
difficult to keep saturated, the nitrogen takes over as the
safety system from the tanks onto the treatment unit.
Metal heat sink flame arresters and water seals are used to
prevent flame front propogation. Monitors are used to detect
explosive mixtures and to shut down blowers and treatment units
when a danger does exist.
4.5.1-3 Other Considerations
The safest and least usage of nitrogen would be a sys-t£3i_w.h-e&e
both the producer and consumer use nitrogen blankets and carriers
were in dedicated service. This system was dropped from the
study since it is thought that it would be impractical to require
industry to use all dedicated carriers.
Another way to avoid an explosive mixture is to dilute the vapor
by injecting air. Enough air is added to keep a saturated vapor
well below the lower explosion limit (L.S.L.) of 1.4? volume
benzene. This would mean adding about 20 parts of fresh air for
every part of saturated benzene vapor. High flow rate blowers
would draw in fresh air and mix with the vapors drawn in from the
carrier hatches or vents. This lean mixture would then be incin-
eratetf"us±ng supplemented fuel. Detection and control devices
would be used to ensure that enough fresh air is added to main-
tain vapor concentrations below the L.E.L. However, at some
point in the dilution process the mixture is in the explosive
range. Incineration is the only practical treatment for diluted
vapor systems because of the high volumetric flow rates involved.
The increased flowrate (due to dilution) would increase the
equipment sizes for refrigeration-adsorption and carbon adsorp-
tion. The only practical service for diluted vapor systems is
iirec- disposal of carrier displacement vapors. This system was
53
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dropped from the study since it could only be used with one type
of treatment (thermal incineration) and its increase in safety
was not sufficiently large to outweigh its negative aspects.
4.5.2 Reliability
The reliability of the three types of vapor treatment units
cannot readily be established for benzene operation. Some of the
units have been tested in benzene service and some have been used
in a service similar to benzene. An attempt will be made to rate
the reliability of each type of unit based primarily on its mech-
anical simplicity where the unit having the fewest moving parts
is considered to be the most reliable.
Using the reasoning stated above, the most reliable vapor treat-
ment unit is the thermal incinerator. Its principle moving parts
are the air damper, fuel control valve and pilot burner ignitor.
The next most reliable vapor treatment unit would be carbon
adsorption. Its principle moving parts are the motor operated
valves, liquid ring vacuum pump for regeneration, benzene pump,
float controls in the regeneration separator, and the coolant
refrigeration unit. (The coolant refrigeration unit can be
omitted if a 60°F source of cooling water is available.) The
regene-ra-t±on system does not have to work when the adsorbing is
actually taking place as long as the carbon bed is sized large
enough. Under this condition the handling of benzene vapors can
be done by a completely passive system. The vapors need only
flpw^ through the regenerated carbon bed. The carbon bed has an
estimated twenty year life because vacuum regeneration eliminates
thermal induced stresses in the carbon and a low bed working
capacity (2% benzene to carbon by weight) is used for design thus
allowing tolerance for degradation.
54
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Refrigeration-condensation-absorption is the least reliable. Its
principle moving parts are the first stage refrigeration unit,
the first stage benzene removal pump, the first stage refrigera-
tion pump, the second stage scrubber lean oil refrigeration unit,
lean oil pump, regenerator vacuun purge pump and second stage
benzene removal pump. The parts that have to work during benzene
vapor flow are the first and second stage units, refrigeration,
lean oil, regenerator vacuum purge, and two benzene removal
pumps. Because of this large number of parts which must work all
at one tine, the benzene vapor cannot flow through a passive
system.
Preventive maintenance is necessary with the refrigeration-
condensation-absorption system. If pure absorption is used, the
first stage parts are eliminated and reliability is improved.
iJ.5-3 Operation
The basic transfer operations required for operating the vapor
control systems described in this report are:
1. a) Transfer of vapor from carriers to storage tank
vapor space prior to treatment or
b) Transfer of vapors from carriers directly to the
treatment systems without intermediate storage
-2-T-- —Storage of benzene vapors using a nitrogen gas blan-
ket .
3. Transfer of vapor from storage to treatment.
4.5.3.1 Transfer of Vapors from Carriers to Treatment Units
or Storage Tanks
Transfer of vapors from carriers requires vapor saturat'ors,
olowers (as required), and associated piping. Liquid pumped into
-r.e carrier displaces vapors through a vent header collection
-------
system located on the carrier, through a vapor hose, through a
metal flame arrestor and water seal, and into a benzene vapor
saturator- (See Figure 4.5.1 and Section 4.5.1.2) From the
saturator, the vapors flow through a metal flame arrestor, a
water seal, a blower, a water seal and metal flame arrestor to
the pipe line that takes them to the treatment unit or storage
tank. The blower is not necessary if the design pressure of the
carrier is sufficient to provide the pressure differential
necessary for flow. The blower is of the positive displacement
involute gear type. Special packing glands are used to isolate
the lubricated parts of the blower from contact with the benzene
vapor. Before entering the treatment unit the vapors again pass
through a metal flame arrestor and water seal.
4.5.3.2 Transfer to Treatment Units
When vapors are treated directly from the carrier, additional
operations are required. These steps are specific for each
technology, and are discussed below.
Thermal Incineration Unit
Before the incinerator can be started, a series of interlocks
must be proved. These include a liquid level control in the
water seal, and a preliminary electrical check for the unit's
co-n-tr-oil-eT flame safeguard controls. Each pilot has its own
flame scanner which must prove ignition before the unit con-
troller takes over and turns on the main fire burners. These
units are started in diagonal pairs to assure optimum flame
symmetry and complete oxidation of vapor (*) . Once the burners
(1) Description courtesy of National Airoil Burner Company, Inc,
56
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are operating, the benzene vapor saturator liquid pump is
started. The blower, which is located close to the saturator,
has a combustible gas monitor located in the inlet and outlet
piping. The blower can be started when the vapors are saturated.
Next the liquid benzene fill is opened and benzene flows into the
carrier by gravity. Vapors are displaced into the saturator
slowly until the benzene pumps are started. In the interim
period, air is drawn in through the saturator pressure vacuum
vent to prevent the blower from surging. This air saturates with
benzene as it flows through the saturator and is burned in the
incinerator- When the air flow stops, benzene loading puaps are
turned on because sufficient vapor is displaced to—b-ui-14 -a
positive pressure in the system.
When the carrier is filled with liquid, the liquid loading valve
is closed and the loading pump shut down. The blower is then
shut down and finally the incinerator is shut down. As the last
bit of combustible vapor is burned, the flame out is prevented
from proprogating upstream by the action of the water seals.
Carbon Adsorbtion Unit
Before the adsorber can be used, at least one of the carbon beds
has to be regenerated and ready to receive flow. The saturator
liquid pump is then started.
If no explosive mixture exists, then the blower is started, the
loading valve opened to fill the carrier, and finally the loading
pump started. The vapor flows through a metal flame arrestor and
water seal into the carbon bed and to atmosphere. Instrumentation
is provided to monitor the tail gas hydrocarbon content and to
give an alarm if the desired benzene level is exceeded.
57
-------
The sequence for shut down is the same as for the incineration
system discussed above.
Refrigeration-Condensation and Absorption Unit
The refrigeration system is operated to cool down itself prior to
introducing benzene vapors. This is done by the first stage
cooling unit refrigerating the first stage vent condenser. The
lean oil pump circulates a stream of lean oil through the second
stage scrubber absorber. When the unit is ready to receive
vapors; the saturator pump is started, then the blower, the
benzene liquid valve opened, and the loading pump started. The
vapor flows through a metal flame arrestor and water seal before
entering the first stage refrigeration-condensation unit. A
non-explosive vapor mixture must be present upstream of the
blower before the blower or treatment unit can be started.
The sequence for shutting down is: shut down the benzene loading
pump, close loading valve, shut down blowers, and shut down vapor
saturator. When the vapor flow is stopped, the first stage
refrigeration unit will shut down. The rich oil regeneration
system will continue to operate until the oil is stripped of
benzene.
4,_5.3._3_ Storage of Benzene Vapors Using a Nitrogen Gas Blanket
The tank vapor space is maintained at a positive pressure by
regulating a makeup stream of nitrogen. As the pressure in the
tank lowers during liquid withdrawal or by ambient cooling, the
pressure control valve bleed's in nitrogen before the vacuum vent
opens.
58
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^.5.3-^ Transfer of Vapors from Storage to Treatment
Vapor saturators are not used to assure a non-explosive mixture,
instead the nitrogen blanket serves this purpose.
For thermal incineration, carbon adsorption and refrigeration-
condensation-absorption, the vapors are pumped from storage by
the use of a blower- The sequence is "similar to the description
given in 4.5.3.2. The pressure rise in the vapor space activates
a switch and starts the blower and treatment unit.
59
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4.6 ECONOMICS
4.6.1 Capital Cost
4.6.1.1 Basis for Estimates
Capital cost estimates were generated for each of the control
cases previously described. All cost figures are given in U.S.
dollars for 1977 fourth quarter. The capital cost estimates
cover the entire monentary outlay required to purchase and in-
stall all the equipment associated with any particular control
scheme at an existing plant. Prices for specialty vapor control
equipment were obtained from vendors as "budget price" (thermal
incineration and refrigeration absorption) and "order of
magnitude estimates" (carbon adsorption). It should be
recognized that wide variations in prices may occur for these
specialty equipment items due to development costs and the
uniqueness of each vendor's item. Bulk commodity items such as
•
piping, steelwork, foundations, electrical supply equipment, and
paint were estimated and priced by Pullman Kellogg's estimating
department. Prices of spare parts for the major treatment
equipment were estimated as percentages of the equipment price.
No spare or backup treatment units as such were included. Spare
blowers were specified for each service to match spare liquid
tpans£er -pumps, thus matching fluid handling reliability- It was
assumed that power and fuel gas are available at the site of the
control equipment and only short distribution lines were
necessary, thus no costs were included for cross plant
distribution lines. Home office costs (insurance, taxes,
engineering, commissioning, overhead, and profit) were estimated
as a percentage of subcontract, labor, and total direct materials
costs.
Cost for modification of transport tankers; railcars, tank
trucks, and barges; were not included in the costs of the various
60
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control cases since most carriers are not owned by the benzene
producer or consumer but are leased from and operated by others.
These costs were estimated separately.
Each control case will require the same modifications to the
carriers. It is virtually impossible to accurately estimate the
cost of modifying the entire fleet of benzene carriers due to un-
resolved question ownership, dedicated, service, and actual number
of carriers requiring modification. The cost of modifying each
carrier can be estimated and these costs are given. The cost of
modifying a railcar or tank truck is estimated at $4,000/vehicle.
A barge modification cost of $68,000 per barge, has been reported
in the literature. ^'
Comparing non-installed capital equipment costs for the three
control technologies, we find that the costs of refrigeration-
adsorption systems and thermal incineration systems for similar
sized units are similar and the cost for vacuum regenerated
carbon adsorption is several times higher. The cost of thermal
incierators probably does not vary much between vendors. The
cost of thermal incinerators increases slowly with increased
capacity, one vendor quotes a 45* price increase for increasing
capacity tenfold on a volume basis from 500 gpm to 5,000 gpm.
Note: Vendors rate their units in gpm of vapor rather than cubic
feet per minute.) The cost of the refrigeration-ad sorption
systems (on the basis of a single vendor) variation with capacity
is more difficult to evaluate due to scarcity of information. A
similar conclusion was reached for the carbon adsorption systems
evaluated.
(1) Background Information on Hydrocarbon Emissions from Marine
Terminal Operations. Volume I, Radian Corporation, SPA Report
No. 450/3-75-03Sa.
61
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It should be noted that several of the design criteria used for
the models have an economic bias peculiar to the carbon
adsorption system and should be discussed. The decision to
evaluate the technologies at their lower but unequal emission
limits subjects the carbon adsorption system to a cost dis-
advantage. Although both carbon adsorption and thermal incinera-
tion are evaluated at 10 ppm, only carbon adsorption suffers a
significant cost handicap. This is because the extra cost of
building a thermal incinerator to reach a 10 ppm limit rather
than a 1000 ppm limit is small, since the difference in achieving
the lower limit is due primarily to the method of operation.
However, the cost difference for building a carbon adsorption
system to go from 1000 ppm to 10 ppm is very large due to the
larger bed volume and therefore larger vessel required. The
extra vessel capacity adds significantly to the cost because of
the vacuum design. Another bias against the carbon adsorption
systems occurs due to the back-to-back barge loading requirement.
This again requires a larger carbon bed capacity or alternately
an extra bed due to the lack of time for regeneration of a spent
bed. This loading requirement does not materially affect the in-
cinerator (which can operate continuously) or the refrigeration-
absorption system (which can regenerate continuously). Each of
these biases can cause a several fold cost increase for the
carbon adsorption systems. The possibility of these dramatic
re_d.ucilons.. of capital and annualized costs as well as increased
cost effectiveness for carbon adsorption systems should be taken
into account when weighing alternatives.
4.6.1.2 Discussion of Cases (See Table M.6.1)
4.6.1.2.1 Case Number Two
Case Number Two provides the lowest capital cost (to producers)
for refrigeration-absorption technology cases and the lowest cost
62
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for thermal incineration cases at $664,000 and $603iOO°
respectively. This is due to the fact that Case #2 has the least
amount of equipment of any case. The carbon adsorption system,
however, ranks as the second most costly among carbon adsorption
systems. This is due directly to the fact that it also has the
second highest special equipment cost. This result is to be
expected since the cost of carbon adsorption systems increases
drastically with increases of capacity when compared to the otker
technologies. The costs of the small and large carbon adsorption
units for Case #2 are $215,000 and $742.»000 respectively. The
costs of the two treatment units for refrigeration-absorption are
$33,000 and 1532,000. Costs of the thermal incinerator unites are
$36,000 and $44,000.
4.6.1.2.2 Case Number Three
Capital costs for Case #3 are greater than Case #2 for each type
of technology, which is to be expected since Case #3 requires
three additional vapor treatment units over Case #2. The pro-
jected capital cost for refrigeration-absorption technology is
$1,068,000 and that for thermal incineration is $1,096,00.
Carbon adsorption technology will require $2,873,000 dollars,
Case #3 represents the most costly case for this technology.
4.6.1.2.3 Case Number Four
In Case #4 she capital cost for carbon-adsorption decreases
dramatically from that of Case #3 as the number and capacity of
treatment units is reduced. The capital cost for Case #4 carbon
adsorption is $1,507,000. This reduction is made possible by
taking advantage of returning vapors from carriers back to the
storage tanks thus reducing the number of treatment units and
tneir capacities. However, similar cost reductions were not
63
-------
observed for the refrigeration-absorption or thermal incineration
technologies, whose costs increased by 45» and 1056 respectively.
Capital cost for refrigeration-absorption is $1,111,000 and
thermal incineration is $1,216,000. This divergence in cost
effects is explained by the relative costs of buying and
installing the treatment units and that of the extra vapor
collection systems. The cost reduction for carbon adsorption
units is greater than the increase due to added vapor piping
systems, thus making Case #4 less than Case #3. For the other
two technologies the added cost of vapor collection systems
outweighs the cost reduction for the vapor treatment units. The
net effect of Case #4 is that carbon adsorption compares more
favorably with the other technologies.
4.6.1.2.4 Case Number Five
Case #5 contains all the items included in Case #4 and adds three
vapor holding tanks to reduce breathing losses. As such the
capital costs of all three technologies are increased over that
of Case #4 by the costs of the vapor tank additions. The capital
costs of the Case #5 technologies are:
Refrigeration-Absorption $1,301,000
Carbon Adsorption $1,971,000
Thermal Incineration $1,349,000
4.6.1.2.5 Case Number Seven
Case #7 represents the first stage of benzene emissions control
for"consumers. The capital cost of $129,000 for Case #7 includes
both large and small consumers. Case #7 does not require any
vapor treatment units, it uses covered floating roof tanks as the
control method.
64
-------
^.6.1.2.6 Case Humber Eight
Case ->3 includes all items in Case #7 and Case #3 adds vapor
treatment units to both the large and small consumers. The cost
of a vapor holder required by the large consumer is included.
The capital costs of the refrigeration-absorption and thermal
incineration systems are respectively $490,000 and $520,000. The
carbon adsorption technology costs $2,-069,000 for Case #3.
4.6.2 Total Annualized Costs
The calculation of total annualized costs for the various control
cases includes costs for utilities, maintenance, labor, capital
charges, and credits for recovered benzene. The utility costs
include electricity, fuel (natural gas), and inert gas (nitrogen)
costs. Electrical and natural gas rates were obtained from local
utility companies as current costs for industrial users. Nitrogen
costs include leasing costs for liquid N storage tank and
vancrizar as well as the cost of the N used. Maintenance costs
2
have been estimated as a percentage of the capital costs for each
case. The cost of operating labor for control cases is estimated
as a percentage of the labor required for the non-controlled
case. This percentage varies with the complexity of the
technology. Labor rates are approximately that of Texas Gulf
Coast_operators receiving union scale wages plus fringe benefits.
Capital charges represent two components; one for capital re-
covery and one for general administrative costs; both are calcu-
lated as fractions of the total capital cost. The capital re-
covery factor is calculated using a 10$ annual interest rate and
equipment life of 15 years and is equal to .13147. The factor
for general and administrative costs is 4?. The credit taken for
recovered benzene is based on a price of $.10/lb. Total annua-
lizes costs are the sun of utility, maintenance, labor, and capi-
tal cr.arges "ir.us benzene recovery credits. Because maintenance,
65
-------
TABLE 4.6.1
Total Capital Costs of Control Cases
for Each Technology
Refrigeration Carbon Thermal
Absorption Adsorption Incineration
Case Number
2
3
4
5
7 129,000 (No technologies added)
8 490,000 2,069,000 520,000
664,000
1,068,000
1,111,000
1,301,000
2,134,000
2,878,000
1,507,000
1,791,000
603,000
1,096,000
1,216,000
1,349,000
66
-------
capital charges, and general administrative costs are all calcu-
lated as a fraction of the capital cost, the capital cost has the
largest effect on the annualized cost. For each case capital
charges represent the largest single cost. A listing of annu-
alized costs for each case is contained in Tables 4,6.2.1 and
4.5.2.2. The annualized costs follow a trend similar to that
observed in capital costs. Carbon adsorption costs are signi-
ficantly higher than its rivals in each case and compares best""ln
Case #4 and Case #5. For carbon adsorption producer cases, Case
#3 is the most expensive to operate followed by Case #2, Case
#5, and Case #4. Annualized costs for refrigeration-absorption
and thermal incineration technologies are close (withJLn_$25-,-OO.OJ
to each other in any particular case. The annualized costs for
refrigeration-absorption ranked from highest to lowest for the
producer schemes are Case #2, Case #4, Case #3. and Case #5. The
cost difference between Case #4 and Case #3 is very small (less
than $1,000). The rankings from highest to lowest for the
producer cases using thermal incineration technology are Case #2,
Case #3, Case #4, and Case #5. The cost spread between Cases 3,
4, and 5 is under $30,000, which is approximately 11? of Case #3
annualized costs.
Annualized costs of benzene emission control for the carriers
(railcars, tank trucks, and barges) is reported on a cost per
car-ri^j?-b-a-sis. Due to the simplicity of the modifications to
railcars and tank trucks, the annualized costs are small. No
utilities are required. Extra maintenance and labor over the
standard procedures is estimated at less than $100/yr. Capital
charges against the small capital cost ($4,000) is less than
$700/yr. No credits have been taken. The total annualized cost
for railcars and tank trucks is $800 per carrier. Annualized
costs for barges is $13,000 per barge. This cost takes into
account maintenance, labor, and capital charges, but not utility
costs or benzene credits.
67
-------
TAIIM-; 4.f,.2.l
Total Annual iced Costs for flrnsonn rrmlncnt Control Cases
r.isn Number
V.ipm Trr.it mcnt Unit
T«'i:hnoloqy
Cci«4t Comp^n^ntf; (in
tlirjusaivls at S/yr
A. utilities3
D. M.i intoivmco rind
Labor
_ C. C.ii-ilal ClMrqoK and"
„ Administrative, Ins.
Tjx-.is
D. Hon7"Ni» Pncovery
(Criylits)
r,,f,i
.'Hut cnM for I'tjlitii'S:
A
Ref-Abs*
0.4
35.1
113.9
(7.7)
141.7
B C
Carb-Ads* Therm- I nc*
1.4 0.3
21.7 18.6
165.9 103.4
(7.0) 4.3
1R1.2 126.6
A
I)'?f-Ahs
53
55.3
183.1
(9.7)
281.7
n
Carb-Ads
55.7
29.1
493.5
(9.8)
Sr,8.5
Electricity - $0.0151/KWII Fili'l Can - $2.73/10'' aul N
percont of tot.il capital cost: nnf riqrration* Absorption *
1.5 (frilne bnnufits. etc.)
4 5
C A 11 CAB C
Tlicrm-Inc Ref-Abs Carb-Acls Tlierm-Inc Pi'f-Abs Carb-AUs Thcui-Inc
-5H.8 26 25. B 28.1 18.6 IB. 4 20.7
33.4 57.5 15.4 37 67 IB. 2 41
1B7.9 190.5 258.4 208.5 223.1 307.1 2)1.3
4.3 (7.1) (7.1) 4.3 (9.3) (9.4) 4.3
284.4 2f.6.9 292.5 277.9 2-11.4 334.1 217.3
vapor - S. 21.5/10 set
5l Carbon Absorption - 1% Thermal Incineration - 3%
nunliour
'c.ipitril charqfs calculated with 10% interest rate and 15 yr»;ir cr|uipmcnt life for capital recovery factor of .1.1147
Ofii'Tf-iii! v til tic = S.lO/lb, credit (or debit) calculated as Licnzene recovered (or lost) compared to Base Case ttl bcnzrne loses
* I*ff r ir]i'iaLinn Absorption - Carbon Adsorption - Thermal Incineration
-------
TABLE 4.6.2.2
Total Annualized Costs for Benzene Consumer
Control Cases
Case Number
Vapor Treatment
Unit Technology
Cost Components
(in thousands of
$/yr)
A. Utilities51
B. Maintenance
ana Labor
C. Capital Charges0
and Administrative,
Ins., Taxes
D. Benzene Recovery
(Credits)
Total
8
A
8
B
8
B
None
Reauired
Ref-Abs* Carb/Ads* Therm-Inc. *
0
2.6
26.1
26.4
27.4
21
31.4
16.1
22.1
(.7)
24
84
(1.3)
135.2
354.8
(1.3)
401.9
89.2
136.7
Unit cost for Utilities: electricity - $. 015.1/KWH
bfuel gas - $2.73/10J scf - N_ vapor - $.265/10 scf
Maintenance estimated as percent of total capital cost:
Refrigeration-Absorption - 5%; Carbon Adsorption - 1%;
TfiefmaT" Incineration - 3%
Labor rate = $8 x 1.5 (fringe benefits, etc)
manhour
Capital charges calculated with 10% interest rate and 15 year
equipment life for capital recovery factor of .13147
^Administrative, Insurance, and Taxes = 4% of total capital cost
Benzene value = $.10/lb, credit (or debit) calculated as
benzene recovered (or lost) compared to Base Case #1 benzene
losses
*Refrigeration-Absorption - Carbon Adsorption - Thermal Incineration
69
-------
4.6.3 Economic Analysis
Cost effectiveness, the most performance per dollar spent over
the period of consideration, is the basis of economic analysis
used to evaluate the control systems. The concept of cost
effectiveness centers on three notions:
1) In the case of two alternatives with the same useful
life giving identical performance, the less costly unit
is more cost effective.
2) In the case of two alternatives with similar useful
lifetimes and equal costs, the unit with the better
performance is more cost effective.
3) In the case of two alternatives with different perfor-
mance and different costs, then the alternative which
delivers the greater performance for unit costs is more
cost effective.
The parameter of cost that will be used for the analysis is
annualized cost (in dollars). The performance parameter is the
amount of benzene emission reduction from the base case of zero
cost, uncontrolled emissions (in Ib/yr). For convenience the
cost effectiveness index is expressed as $/lb reduction, rather
than Ib reduction/$. Thus the lower the index, the more cost
effective the alternative. The cost effectiveness for each case
is_glv_en-in Table 4.6.3-1 and 4.6.3.2. It is observed that the
carbon adsorption technology represents the least cost effective
system for each case. The differences between refrigeration-ab-
sorption and thermal incineration are small within most cases,
and is greatest in Case #2 where the difference is less than 12%
of the less costly technology (thermal incineration). The
average cost effectiveness of thermal incineration is higher by a
very small margin. The carbon adsorption technology compares
closest with the others in Case #4 and Case #5.
70
-------
MKIII-..III.I-. ill SI
T/IIII.I: i.e.. J.I
1:1 it-i'i ivriHi'is or I'rnitiH i-f r'niiifiii
ii
IH'l-Al.s1 r. uli-A 1,111 >.v>; i,2ir> i.iui 1,791 1,140
Alum il irnl i i.-.i (III HI. 7 Jill. I IPIj.d ^li/.n S'jl.l 210.1 2bfi.9 J'11.4 270 1111 151.1 I'll. I
i him' .in.l'i uf S/yi )
!!.•! |., ,|,i, i i.,,, ,,( 77,407 /II.O'jO 77,9l'i Vfi.BM 9>,S94 97,4^0 70,6*11 71,251 71,11'J 91.1UO 9-1,041 91, (IIS
lli-ii.-.'n. lmi!,',uiiis (Ili/yr)
I..M III- IIVMI ...... . In.l-'X I.H) 4.HH l.bl 2.7A &.(,; 2.76 1.7U 4.11 J.MO 3.41 1.75 J.I7
IS/11. I— In. lion)
•!'«•( i nn'i «iLlon AhMir |it Ion - Cerium Ailsorpl lent - Tlu'rmal liujliii'i A\ inn
-------
TABLE 4.6.3.2
Cost Effectiveness of Consumer Control Cases
NJ
Case Number
Treatment Unit
Technology
Capital Cost (in
thousands of $)
Annualized Cost (in
thousands of $/yr)
Net Reduction of
Benzene Emissions
(Ib/yr)
Cost Effectiveness
Index
($/lb Reduction)
8
B
None Required
129
24
7,255
Refrigeration
Adsorption
490
135.2
17,608
Carbon
Adsorption
2,069
401.8
17,666
Thermal
Incineration
520
136.7
17,654
f
3.31
7.68
22.74
7.74
-------
In tne producer cases, the order of cost effectiveness for the
refrigeration-absorption and thermal incineration technologies in
descending order is Case #2, Case #3, Case #5, and Case #4. The
descending order of cost effectiveness for carbon adsorption is
Case #5, Case #4, Case #2, and Case #3.
The mosr cost effective control scheme is Case #2 with thermal
oxidation at $1.63/lb, and Case #2 with refrigeration is the next
most cost effective at $1.83/lb. If the cost of benzene
increased and/or the price of natural gas increased relative to
electricity, the cost effectiveness of refrigeration-absorption
would increase relative to thermal incineration.
The most judicious area to spend money on benzene emissions is in
the loading area. One pound of benzene emission can be reduced
for $1-63 in Case #2 with thermal incineration, where both
storage and loading losses are controlled, compared witti $3.30
spent for an equal unit reduction of standing storage losses in
Case #7. The least attractive investment for control expenditures
is to attempt to control both standing and withdrawal losses as
in Case #3. A base case starting with cone roof tanks rather
than floating roof tanks would show that the most effective place
to begin benzene emission control is with the storage tanks,
because emissions from cone roof tanks are approximately 5-10? of
c_one__rP-Pf-tank emissions.
73
-------
SYMBOL
FA
PV
APPENDIX A
LEGEND
DESCRIPTION
Metal Heat Sink
Flame Arrester
Water Seal
Pressure-Vacuum
Vent Valve
9 5
r
)
r^l
f^\
J V J 1
r
1
t
)
t
>
Rotary Type Blower
Pressure Switch
Vapor Flow Lines
Liquid Flow Lines
Check Valve
(showing flow
direction)
Centrifugal Pump
-------
APPENDIX 'B
English to Metric Conversion Chart
1 pound equals .4536 KG
1 gallon equals 3.785 liter
1 ft3 equals .02832 m3
-------
APPENDIX C
CAPITAL COST DATA
CLIENT
EPA
LOCATION :
Texas Gulf Coast
CLASS
OR
A.C NQ
B
C
C
E
F
J
L
U
:
A
H
K
M
N
O
f
*
"•>•.,,
MS
lip7 nno
i n j r nnnl 1 nj nno
5nfi r nnn
22.000
140.000
43.000
17.600
T^n . oon
1 40. 000
2.134 . nnn
TIT. nnn '
6.000
40.000
6.500
5.000
i on . nno
4 ft , no o
fi n i . n ii o
)
-------
APPENDIX C
CAPITAL COST DATA
EPA
--CAT
CL»SS
OR
» C »*O
9
5
Texas Gulf Coast
DESCRIPTION
E TONERS
r I ;auu< a TANKS
j i P..'*»S »-0 COMPRESSORS
lefrigera-
tion
Vbsorceion
20.000
CONTROL CASE S3
Carbon
Adsorptioi
20,000
27.500 27,500
L • !>>SCiAL ECUIP-EXT I1 OO. £00
j
•.•T.LI1'^ E3Ji»««E«T
-a*«.5PO"»~*Tic«» a CONVE»i**G EC'JIP
1.252.500
Thersal
Oxidatior
20 ,000
27 , 500
202 , ;00
!
1 riEE & S«'£TY £SL'lP"C*r
| _..-,_^™.- ..1Tos> -.~,.T-'.rV" (•"".200
• si-s ••»» r?us2A7iews a cc««c. «~Rnn i is.nooi 16,000 i
•SSUU>T:O-.S ANOPAi-i- | 1.S.TO 1 1.50C
• CA-A.»ST ANC CHEWICAL* 1
-•—^Mmm^r OfTT V Vi^r-VTiT 1 O^.^CQ
M4
"£'c-- - -~.LL=cArE= •> . non _
1,500
D!;.500I 95,500
8.0001 2,000 1
E,^-- ..«..,-, .-ALLCCA-EC
i :S "1 1. S i • £ : I «W ' f 9 H L T5I 5T" I ' STT.SfllllJS.SQO I
. -:7iL JL'3CSrw::s .»:L. EjC»-«:,a --^ pn^ > ^oj.^.i^i ^"i.^^n
1 I
113
CC-.STO ro°CE-->:E«a "I»,CE i-> e •! s.ii I^T «;.•<".! ~.'3."1'<.C 1
::c ' «!£-: •:» SIREC- ;_-PE=WO" a svc 1 •
*3O i TOCLS » P«£.C^T O* TOOUS | '
5=0
110
E:=ALATIOM - LABOR
7OO
SP-'.P.E ?A?.TS j
AOO | MOME O"iCC CCMBIMCC CNGIMCBMING
"O*"E O'riCE CLIENT SERVICE
MO
It*
"••• .1
SALES a USE TAX - UNALLOCATED
IUBORT DUTIES
or-ro CC?TS t L'C TEES »O"«Lne^i
Jpn.-.^, >..vorr.,T^.,
J
13 , iOO
70,500
_
15,500
3, 300
1
30 , 500
icS , 500
62,200
23 ,700
i _,*.._.,. ^OT.^r)C ^ti to i ' ^ , 000 ' 4/1,300
1 1
!•< , 000
/ ^ , . •- J
lo,iOO
i , uOu
j-J J , 300
1
1
'"-"'I- C5SI ''. **1 .*** <2 .:'-,'. •'. ) 1'. . j;"i . ; J3 '•
1 i
1
' 1
-------
APPENDIX C
CAPITAL COST DATA
C-if.r
FT> a
LOCATION :
Tpxas Gulf Coast
CLASS
01
« C SO
a
c
3
E
e
J
DESCRIPTION
FURNACES
EXCHANGERS
CONVERTERS
10-ERS
P'JXPS AND COMPRESSORS
L 1 SPECIAL EQUIPMENT
U 1 UTILITY EQUIPMENT
1 TEAS•>- \«^ rno r-nr-TTJVPVT
SiTI ""IP FOUNDATIONS » CCNC. STHUC.
IN STEEL S~RCC PLATFORM* ft INOUST BL..
< 1 ARCHITECTURAL BUILDINGS
u PIPING
.N 1 EL.5"RICA'_
C
p
w
nja,..
INSTRUMENTS
INSULAT1CS-S AN° PAINT
CATALYST AND CHEMICALS
CrT=mnn«T BrTTV ViiTfpTaT.
I e = IiG»T _ uNA^LOCATES
•15 STO=.«CE - »=ecT MATERIAL
116 E»PO«- PACX'NS - UNALLOCATED
ESCALATION MATERIAL
i TSTiu Iir£Cr «.UE»lAL
TOUS. S'.'KSJTMCTS IHCL. ESCAUTIO
31C COSSTP. *O"»CE - WAGES 4 FRINGE
}»
:•«
430
SCO
130
.
too
700
£00
««l
110
111
'"*,«'
910
9I<
CCN5TR FORCE - PAVPOLL ASSESSMENTS
FIEL3 ACM. DIRECT SUPERVISION a. SVC
TOOLS A FREIGHT ON TOOLS
FIELD OFFICE ft OTHER FIELD EXPENSE
INDIRECT MATERIAL 1 ST 6 V 1
ESCALATION - LABOR
CD.inp P^DTK;
HOME OFFICE CONSTRUCTION
HOME OFFICE PROCUREMENT
HOME OFFICE COMBINED CnGINCERING
CENTRAL STAFr-
HOME OFFICE CLIENT SERVICE
SALES a USE TAX - UNALLOCATED
IMPORT OU TIES
OCEAN FRT MARINE INSURANCE ETC
OTHER CCST5 1 LIC FFES ROYALTIES 1
INSURANCE 1 ALL RISKS ETC 1
(-'("'.••'••T.-.rTiiic nutp
| CONTiNCE'.C"
1 70T1L COSI
1
Refrigera-
tion
Absorption
1 •) non
7i s =;nn
f-> zr\n
oo n n ri
i •> nnn
T ^f>n
PT nnn
•?j nnn
1 sr nnn
1 , snn
i =i5 . nnn
•> nnn
OESCRlPTiON :
CONTROL CASE * 4
Carbon
\dsorptior
1 1 nnn
•>& s ";nn
~~p =;nn
Thermal
Oxidation
15 nnn
?i . =;nn
o q ^ r> n
1
71 ^ nnn
IT nnn
T snn
07 non
li , nno
i s .nnn
i . "inn
i =;? .nnn
? s nnn
?-T «"n -f.c\ nan
IT* nnn
i ? nnn
•? son
07 nno
T i . 0 0 n
i s . n n n
1 .500
i 5' .non
? r nnn
TOO nnn
i ru nnn hnj nnn in.: nnn
~3gn.4nn
t
1 -
1
J
inrnnn
i
1
! 7.1 r nnn
-
15 r i nn
1 1 nnn
183,800
335.900
q.ono
<5fi .ono
21 .ino
i A j jnn
299,600
381.400
11.200
77.200
14 .100
i i finn
2-10,600
!
!
.
1
1
73,500 1 96,000 1 it, -GO j
1, lli,000ll, 507, OOOIi.Jlo, 000
-------
APPENDIX C
CAPITAL COST .DATA
C-.tNI
EPA
Texas Gulf Coast.
c - « » i
3* OCSCIIIPTION
'- 1C*e°'
i : = IC'«- muiPMe*"
Refrigera-
Absorptior
CONTROL CASE *5
Carbon
Vdsorptior
fi.i.-.:v", nor. .«OP,
u ! ,~..T- ceu.—e.r
Tharsal
Oxidation
24,5001 !
1V3.TO ! I
i «'-=7C5TAI. .'-'.-.JO?. ECUIrME^T _CC,:00 ljj.5,500
1 ; 1 ;
- 3 o , : 'j 0 ! |
, | ,:-^ =,.». «•£•_•-.;» -10*5 i C2—:. ST"UC 1 ^ •" T1 •"" 0 " " 1 n 7 IT 1 1 i
- i s-i-_ :-°\.z =•_»•*:•=«•! a I^CUST eu B.«r>.n ' s •'oi
* »=--'-£"->»:_ 3uil.='NO«
u •.•••.C
1
e -. ,1 n i
1
9 .1 n .1 rt ' ? . .1 .". .1 « s . n .1 n
, i r-_s;-=io>i. 1 Tl T"i I1 l"n 11 ,"O1
s i-.5-ov.-««-5 '« s-i.i "•_i'.-.ri...<. 1
I 1 I 1
1 •::.. s^gru:- ••:•.. cici^nfti ^. ;.';,; ,;^;^:;' ! — -;j ;••.:; i !
:TC i «-is_: »s- sioe:- s.-"«=«i»io^ » jwc
«M 1 TOOLS > roeic»"- 3~ -COLS
S5;3=1 or. sm«
res:»i.»Tio"< - UAUOK
'so i ~o-e of 'ice. p«ocvj»e»«NT
«oo «o»c orrrce co-"'«eo OCINI.JIIIMC:
-O»t O»nCE CLIENT sfovict
MO S*LEI 1 U1C TA» - UN*kLOCATCO
111 1 tuoo"' OUTIES
10 1 O'-r» C=-.TT : tic rtis »O»«L-!t5 1 1
_• . 1
.in.non
1
c
10 . = on
1 •>« ~."n_ iii« ^T1
—
i n oofl
?n nnn
i 1 .000
an i •< ,1
l i. Ann
1
i * 2 r< -i
1 1 1
1 1
1 1
-------
APPENDIX C
CAPITAL COST DATA
CLIENT .
EPA
LOCATION :
Tiavaa Gulf Coast
CLASS
OR
A-C NO
B
o
C
F
J
L
u
V
-
DESCRIPTION
FURNACES
CONVERTERS
1O»ERS
DRUMS & TANKS
PUMPS AND COMPRESSORS
SPECIAL EQUIPMENT
UTILITY EQUIPMENT
TRANSPORTATION A CONVEYING ECUIP
FIRE » SAFETY EQUIPMENT
1
» 1 SITE P"EP FOUNDATIONS > CCNC STRUC.
» STEEL STRUC PLATFORMS 1 IhOUST. BL.
K 1 ARCHITECTURAL BUILDINGS
M
N
O
PIPING
ELECTRICAL
INSTRUMENTS
P 1 INSULATIONS AND PAINT
w
"3»-=3
•15
tie
310
3U
200
AOO
500
130
-1
;
1 600
700
COO
941
190
HI
"",61
910
1
CATALYST AND CHEMICALS
*
'REICHT - UNALLOCATED
STORAGE - DIRECT MATERIAL
EXPOS- PACKING - UNALLOCATED
ESCAL»TiON MATERIAL
T07U 3IIECT lUTHIiL
ro'iL SU3CS:*UCT5 IK:L. ESCAUTION
CCNSTP FORCE - WAGES & FRINGE
CONS-R FORCE - PAYROLL ASSESSMENTS
FIELO AOM DIRECT SUPERVISION A SVC
TOOLS » FREIGHT ON TOOLS
FIELD OFFICE * OTHER FIELD EXPENSE
INDIRECT MATERIAL ( ST 5 Y 1
'ESCALATION - LABOR
CP&P" DZVPTR
HOME OFFICE CONSTRUCTION
HOME OFFICE PROCUREMENT
HOME OFFICE COMBINED INCINCEKING
CENTRA L STA ff
HOME OFFICE CLIENT SERVICE
SALES & USE TAX - UNALLOCATED
IMPORT DUTIES "
OCEAN FRT MARINE INSURANCE ETC~
OTHER COSTS 1 LIC FEES ROYALTIES 1
nnrt Tr1/""!* /""OMDT FTTnV
/*o»"nr>^ r""F|r*T3C f\\l r n
CONTINGENCY
10'iL COST
60,000
'125,000
i
_
1,000
-1
1
1 8.500
-
2.600
1 .000
•51 flnn
H <;f>n
i in oon
DESCRIPTION :
CONTROL CASE 5 7
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APPENDIX C
CAPITAL COST DATA
...IN
EPA
..-CA -.ON .
Texas Gulf Coast
OM
• "~ NO
OCICftl'TION
g t f'J*««*CeS
£ 1 *o-e«i
J
— =—
Refrigera-
Absorption
CCMTP.OL CASS S3
Carbon
i.dsorptior
Thersval
Oxidation
1
1
1
p._u>f ».s c=-"»ts5O«» 5,000 i 5,CGo 1 i.jo'u | ;
1 1
i -o«^«e:«»»-ic« » =»".-ei-"*s ES'J!" 1 ! i
. Sr-j rare 'CVVSA r!C"rt • CI«<:. ST«'_C 1 C . " n "! ' 1 . T •" •"> 4 . '" 0 0 1 '
' sr£E'_ s-°-c "-AT'O""! a PROUST su. 1 T =;->n 1 "> = •" r i 3. = ">Q I
. , ••C«>'C=T.»A-_ 9un.i!~« I 1 '
« i oi».^c is T-.I 1 la nrii-i I 15."r>0
•• E-_£:- = 'CAi. s -in ->S T" S PiVi
o
.«To..«E-.r^ | -n so-. 1 19 -"0 1 10 anfi |
• 1 C*~A'vvfT AM3 CHCVICAUS 1
C"Sr*«»w •* ^r^rv vl*^ff^~lr 1 44. '^00 T?.?Pj
••i
i 1
1
40,500
1 . 000 . 1:
1 1
t"TTi:.:ifrc"''.A":*:iL ""I ^^f* i"1 .•'•^•* -IT^I ij-^ ^0^
I "t'i* S'JSI^T'j;" I>:L. ESCi^Ticn I -ir i^-> i i-,ri-->. i n: . 7 ' ^ ' 1
1 1 1
110
1M
436
t C ?•' S " a ^O**C E-*»jiS4e*iNCS ™^m%S "* *^. ^ ' l""n S.^i;~| !•*<— * f* n f
Cr*»5^1' 'CI*CE — s»^*C(.ta * U E iSfc"E N * S 1 i
TSCV.S a tafd'-r si TOOLS
S5O FiE-D O'^'CC 4 OTwen 'IEUC CX^CNiEt '
>;o
VOO
l~OI"£CT UAT^RlAL 1 ST » T 1
c:,*.* D«T^
4,500
lMO>EO«ncE-"'Og..-.C^r>r
»<» MO-t 0"IC1 C0-1i>.t3 c»CI-U"i-0 32,lOO
190
111
»CME OTICE CLiEKT 5CBVICE
SALES 6 USE TAX - UMALLOCATCO
IMMOPT 3u TIES
'"• 4,i 3CE«- '•»' M.ai^e mluRA~Ce ETC-
?13
°'-'" ces-j. L.CJTJE, oo».^.t?'
„„.,„, ^..pT-,Tr>;
.J
4,500
i
21. 300
L 35 , 50 3
43,000
5,OJO
J1 , ju J 1
5,000
4,000 17.000 1 4,500
I 1
1
1 i
!
1
' 1
1
1 j
-------
APPENDIX D
REFERENCE LIST
American Petroleum Institute; "API Bulletin 2513: Evaporation
Loss in the Petroleum Industry - Causes and Control," American
Petroleum Institute, 2101 L. Street, Northwest, Washington, D.C.
20037
"API Bulletin 2514: Evaporation Loss from Tank Cars, Tank Trucks,
and Marine Vessels," (1959)
"API Bulletin 2517: Evaporation Loss from Floating-Roof Tanks,"
(1962)
"API Bulletin 2518: Evaporation Loss from Fixed-Roof Tanks,"
(1962)
En_v.ic.ojimerLtal Protection Agency; "Compilation of Air Pollutant
Emission Factors, (1977 Supplement 7)," U.S. EPA Office of Air
Quality Planning and Standards, Research Triangle Park, North
Carolina 27711
Hughes, John R.; "Storage and Handling of Petroleum Liquids:
Practice and Law," (1967); Charles Griffin and Company Limited,
42 Drury Lane, London, Great Britain, W.C.2
-------
REFERENCE LIST (Cont)
Pacific Environmental Services, Inc.; "Reliability Study of Vapor
Recovery Systems at Service Stations," (1976); Environmental
Protection Agency, Air Pollution Technical Information Center,
Research Triangle Park, North Carolina 27711
PEDCo Environmental, Inc.; "Atmospheric Benzene Emissions,"
(1977); Library Services Office (MD-35), U. S. Environmental
Protection Agency, Research Triangle Park, North Carolina 27711
Radian Corporation; "A Study of Vapor Control Methods for
Gasoline Marketing Operations: Volume I - Industry Survey and
Control Techniques"; Air Pollution Technical Information Center,
Environmental Protection Agency, Research Triangle Park, North
Carolina 27711
Radian Corporation; "Background Information on Hydrocarbon
Emissions from Marine Terminal Operations, Volumes I and II";
Library Services Office (MD-35), Environmental Protection Agency,
Research Triangle Park, North Carolina 27711
-------
APPENDIX E
LIST OF VENDOR BROCHURES
Ecology Control, Inc., "Vapor Management Systems," 6810 La Paseo
Drive, Houston, Texas 77017
Edwards Engineering Corp., "Hydrocarbon Vapor Recovery Unit,"
Form 8-VRBZ-l, 101 Alexander Avenue, Pompton Plains, New Jersey
07444
Hoyt Manufacturing Corp., "Solvent Recovery Systems," 251 Forge
Road, Westport, Maine 02790
Hydrotech Engineering Inc., "Vapor Recovery Systems," P. 0. Box
45042, Tulsa, Oklahoma 74145
Oxy-Catalyst, "Oxycat Catalytic Abatement Systems," East Biddle
Stre_etj__We5t Chester, Pennsylvania 19380
Oxy-Catalyst, "Oxycat CA-66 Solvent Recovery System"
National Airoil Burner Company, Inc., "NVDU NAO Vapor Disposal
Unit"" Bulletin 39A, 1284 East Sedgley Avenue, Philadelphia,
Pennsylvania 19134
-------
TECHNICAL REPORT DATA
(Please reed Instructions on the reverse before completing)
1. REPORT NO.
EPA-450/3-78-018
2.
3. RECIPIENT'S ACCESSION NO.
4. tITLE AND SUBTITLE
Evaluation of Control Technology for Benzene
Transfer Operations
5. REPORT DATE
April, 1978
6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
S. VI. Dunavent, D. Gee, and W. M. Talbert
8. PERFORMING ORGANIZATION REPORT NO,
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Pullman Kellogg
16200 Park Row, Industrial Park Ten
Houston, Texas 77084
10. PROGRAM ELEMENT NO.
11..CONTRACT/GRANT NO.
68-02-2619, Task 2
12. SPONSORING AGENCY NAME AND ADDRESS
U.S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
13. TYPE OF REPORT AND PERIOD COVERED
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
OAQPS Project Officer for this report is David W. Markwordt, MD-13,
(919) 541-5371
16. ABSTRACT
This report presents results of a study which selected and evaluated
best available technology to control emissions from benzene storage ajid
transfer facilities. Technologies selected and evaluated include refrigeration-
absorption, vacuum regenerated carbon adsorption, and thermal oxidation.
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Hdd/Group
Air Pollution
Control Methods
Benzene
Tankers and Barges
RaiTears and Tank Trucks
Storage Tanks
Air Pollution Control
Benzene Emission Control
Organic Vapors
Mobile Sources
8, DISTRIBUTION STATEMENT
Unlimited
19. SECURITY CLASS (This Reporti
Unclassified
21. NO. OF PAGES
Q?
20. SECURITY CLASS /Thispage/
Unclassified
22. PRICE
EPA Form 2220-1 (Rer. 4-77) =RCV'OUS Eiri
s OBSOLETE
-------
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