United States Office of Air Quality EPA-450/3-80-028c
Environmental Protection Planning and Standards December 1980
Agency Research Triangle Park NC 27711
Air
Organic Chemical
Manufacturing
Volume 8: Selected
Processes
-------
EPA-450/3-80-028C
Organic Chemical Manufacturing
Volume 8: Selected Processes
Emission Standards and Engineering Division
U.S. Environmental Protection Agency
Region V. Library
230 South Doarbcrn Street
Chicago, Illinois 60604
U.S. ENVIRONMENTAL PROTECTION AGENCY
Office of Air, Noise, and Radiation
Office of Air Quality Planning and Standards
Research Triangle Park, North Carolina 27711
December 1980
-------
U,S- Environmental Protection Agency
-------
Ill
This report was furnished to the Environmental Protection Agency by
IT Enviroscience, Inc., 9041 Executive Park Drive, Knoxville, Tennessee
37923, in fulfillment of Contract No. 68-02-2577. This report has been
reviewed by the Emission Standards and Engineering Division of the
Office of Air Quality Planning and Standards, EPA, and approved for
publication. Mention of trade names or commercial products is not intended
to constitute endorsement or recommendation for use. Copies of this report
are available, as supplies permit, through the Library Services Office (MD-35),
U.S. Environmental Protection Agency, Research Triangle Park, N.C. 27711,
or from National Technical Information Services, 5285 Port Royal Road,
Springfield, Virginia 22161.
-------
-v-
CONTENTS
Page
INTRODUCTION vii
Product Report Page
1. ETHYLENE DICHLORIDE 1-i
2. CARBON TETRACHLORIDE AND PERCHLOROETHYLENE BY
THE HYDROCARBON CHLORINOLYSIS PROCESS 2-i
3. FLUOROCARBONS 3-i
4. 1,1,1-TRICHLOROETHANE, PERCHLOROETHYLENE, TRICHLOROETHYLENE,
AND VINYLIDENE CHLORIDE 4-i
5. CHLOROMETHANES BY METHANE CHLORINATION PROCESS 5-i
6. CHLOROMETHANES BY METHANOL HYDROCHLORINATION AND METHYL
CHLORIDE CHLORINATION PROCESSES 6-i
-------
Vll
INTRODUCTION
A. SOCMI PROGRAM
Concern over widespread violation of the national ambient air quality standard
for ozone (formerly photochemical oxidants) and over the presence of a number
of toxic and potentially toxic chemicals in the atmosphere led the Environ-
mental Protection Agency to initiate standards development programs for the
control of volatile organic compound (VOC) emissions. The program goals were
to reduce emissions through three mechanisms: (1) publication of Control Tech-
niques Guidelines to be used by state and local air pollution control agencies
in developing and revising regulations for existing sources,- (2) promulgation
of New Source Performance Standards according to Section lll(b) of the Clean
Air Act; and (3) promulgation, as appropriate, of National Emission Standards
for Hazardous Air Pollutants under Section 112 of the Clean Air Act. Most of
the effort was to center on the development of New Source Performance Stan-
dards .
One program in particular focused on the synthetic organic chemical manufactur-
ing industry (SOCMI), that is, the industry consisting of those facilities
primarily producing basic and intermediate organics from petroleum feedstock
meterials. The potentially broad program scope was reduced by concentrating on
the production of the nearly 400 higher volume, higher volatility chemicals
estimated to account for a great majority of overall industry emissions. EPA
anticipated developing generic regulations, applicable across chemical and
process lines, since it would be practically impossible to develop separate
regulations for 400 chemicals within a reasonable time frame.
To handle the considerable task of gathering, assembling, and analyzing data to
support standards for this diverse and complex industry, EPA solicited the
technical assistance of IT Enviroscience, Inc., of Knoxville, Tennessee (EPA
Contract No. 68-02-2577). IT Enviroscience was asked to investigate emissions
and emission controls for a wide range of important organic chemicals. Their
efforts focused on the four major chemical plant emission areas: process
vents, storage tanks, fugitive sources, and secondary sources (i.e., liquid,
solid, and aqueous waste treatment facilities that can emit VOC).
121A
-------
Vlll
B. REPORTS
To develop reasonable support for regulations, IT Enviroscience gathered data
on about 150 major chemicals and studied in-depth the manufacture of about
40 chemical products and product families. These chemicals were chosen consid-
ering their total VOC emissions from production, the potential toxicity of emis-
sions, and to encompass the significant unit processes and operations used by
the industry. From the in-depth studies and related investigations, IT Enviro-
science prepared 53 individual reports that were assembled into 10 volumes.
These ten volumes are listed below:
Volume I -. Study Summary
Volume II : Process Sources
Volume III : Storage, Fugitive, and Secondary Sources
Volume IV : Combustion Control Devices
Volume V : Adsorption, Condensation, and Absorption Devices
Volume VI-X: Selected Processes
This volume is a compilation of individual reports for the following chemical
products: ethylene dichloride, carbon tetrachloride, perchloroethylene, fluoro-
carbons, 1,1,1-trichloroethane, trichloroethylene, vinylidene, and chloro-
methanes. The reports generally describe processes used to make the products,
VOC emissions from the processes, available emission controls, and the costs
and impacts of those controls (except that abbreviated reports do not contain
control costs and impacts). Information is included on all four emission
areas,- however, the emphasis is on process vents. Storage tanks, fugitive
sources, and secondary sources are covered in greater detail in Volume III.
The focus of the reports is on control of new sources rather than on existing
sources in keeping with the main program objective of developing new source
performance standards for the industry. The reports do not outline regulations
and are not intended for that purpose, but they do provide a data base for
regulation development by EPA.
C. MODEL PLANTS
To facilitate emission control analyses, the reports introduce the concept of a
"model plant" (not in abbreviated reports). A model plant by definition is a
representation of a typical modern process for production of a particular chem-
ical. Because of multiple production routes or wide ranges in typical production
-------
IX
capacities, several model plants may be presented in one product report.
The model plants can be used to predict emission characteristics of a new
plant. Of course, describing exactly what a new plant will be like is diffi-
cult because variations of established production routes are often practiced by
individual companies. Nonetheless, model plants provide bases for making new-
plant emission estimates (uncontrolled and controlled), for selecting and siz-
ing controls for new plants, and for estimating cost and environmental impacts.
It is stressed that model-plant analyses are geared to new plants and therefore
do not necessarily reflect existing plant situations.
-------
REPORT 1
ETHYLENE DICHLORIDE
J. A. Key
F. D. Hobbs
IT Enviroscience
9041 Executive Park Drive
Knoxville, Tennessee 37923
Prepared for
Emission Standards and Engineering Division
Office of Air Quality Planning and Standards
ENVIRONMENTAL PROTECTION AGENCY
Research Triangle Park, North Carolina
October 1980
This report contains certain information which has been extracted from the
Chemical Economics Handbook, Stanford Research Institute. Wherever used, it
has been so noted. The proprietary data rights which reside with Stanford
Research Institute must be recognized with any use of this material.
D24N
-------
CONTENTS OF REPORT 1
Page
I- ABBREVIATIONS AND CONVERSION FACTORS 1-1
II. INDUSTRY DESCRIPTION H-l
A. Reason for Selection II-l
B. Usage and Growth II-l
C. Domestic Producers II-l
D. References II-7
III. PROCESS DESCRIPTION III-l
A. Introduction III-l
B. Direct-Chlorination and Oxychlorination (Air) Processes III-l
C. Direct-Chlorination and Oxychlorination (Oxygen) Processes III-5
D. Process Variations III-7
E. References III-9
IV. EMISSIONS IV-1
A. Direct-Chlorination and Oxychlorination (Air) Processes IV-1
B. Direct-Chlorination and Oxychlorination (Oxygen) Processes IV-7
C. Current Emissions IV-8
D. References IV-11
V. APPLICABLE CONTROL SYSTEMS V-l
A. Direct-Chlorination and Oxychlorination (Air) Processes V-l
B. Direct-Chlorination and Oxychlorination (Oxygen) Processes V-6
C. References V-7
VI. IMPACT ANALYSIS VI-1
A. Environmental and Energy Impacts VI-1
B. Control Cost Impact VI-3
C. References VI-11
VII. SUMMARY VII-1
-------
1-v
APPENDICES OF REPORT I
A. PHYSICAL PROPERTIES OF EDC AND ETHYLENE h~l
B. AIR-DISPERSION PARAMETERS B~1
C. FUGITIVE-EMISSION FACTORS C~1
D. COST ESTIMATE SAMPLE CALCULATIONS ®~l
E. LIST OF EPA INFORMATION SOURCES E~1
F. EXISTING PLANT CONSIDERATIONS F"1
-------
1-vii
TABLES OF REPORT 1
Number
II-l Ethylene Bichloride Usage and Growth II-Z
II-2 Ethylene Bichloride Capacity II-3
IV-1 Uncontrolled Emissions of EDC and Total VOC IV-3
IV-2 Composition of Oxychlorination (Air) Vent Gas IV-4
IV-3 Storage Tank Data IV-6
IV-4 Compositon of Oxychlorination (Oxygen) Vent Gas IV-9
V-l Controlled Emissions V-2
VI-1 Environmental Impact of Emission Controls VI-2
VI-2 Annual Cost Parameters VI-5
VI-3 Emission Control Cost Estimates for Ethylene Bichloride VI-6
VII-1 Emission Summary VII-2
A-l Physical Properties of 1,2-Dichloroethane A-l
A-2 Physical Properties of Ethylene A-2
B-l Air-Dispersion Parameters (Air) B-l
B-2 Air-Dispersion Parameters (Oxygen) B-2
F-l Emission Controls Used by the Ethylene Dichloride Industry F-2
F-2 Reported Uncontrolled Emissions from Oxychlorination Vents F-4
F-3 Reported Uncontrolled Emissions from Direct-Chlorination Vents F-5
FIGURES OF REPORT 1
II-l Locations of Plants II-4
III-l Ethylene Dichloride from a Balanced Process III-3
III-2 Ethylene Dichloride by Oxygen Process III-6
VI-1 Installed Capital Cost vs Plant Capacity VI-7
VI-2 Net Annual Cost vs Plant Capacity VI-9
D-l Precision of Capital Cost Estimates D_2
-------
1-1
ABBREVIATIONS AND CONVERSION FACTORS
EPA policy is to express all measurements used in agency documents in metric
units. Listed below are the International System of Units (SI) abbreviations
and conversion factors for this report.
To Convert From
Pascal (Pa)
Joule (J)
Degree Celsius (°C)
Meter (m)
Cubic meter (m3)
Cubic meter (m3)
Cubic meter (m3)
Cubic meter/second
(ms/s)
Watt (W)
Meter (m)
Pascal (Pa)
Kilogram (kg)
Joule (J)
To
Atmosphere (760 mm Hg)
British thermal unit (Btu)
Degree Fahrenheit (°F)
Feet (ft)
Cubic feet (ft3)
Barrel (oil) (bbl)
Gallon (U.S. liquid) (gal)
Gallon (U.S. liquid)/min
(gpm)
Horsepower (electric) (hp)
Inch (in.)
Pound-force/inch2 (psi)
Pound-mass (Ib)
Watt-hour (Wh)
Standard Conditions
68°F = 20°C
1 atmosphere = 101,325 Pascals
Multiply By
9.870 X 10~6
9.480 X 10"4
(°C X 9/5) + 32
3.28
3.531 X IO1
6.290
2.643 X 102
1.585 X 104
1.340 X 10~3
3.937 X 101
1.450 X 10~4
2.205
2.778 X 10"4
PREFIXES
Prefix
T
G
M
k
m
M
Symbol
tera
giga
mega
kilo
milli
micro
Multiplication
Factor
1012
109
10G
103
io"3
io"6
1 Tg =
1 Gg =
1 Mg =
1 km =
1 mV =
1 ug =
Example
1 X IO12 grams
1 X IO9 grams
1 X IO6 grams
1 X IO3 meters
1 X IO"3 volt
1 X 10~6 gram
-------
II-l
II. INDUSTRY DESCRIPTION
A. REASON FOR SELECTION
Ethylene dichloride (EDC) was selected for consideration because preliminary
estimates indicated that the large amounts produced and the moderate to high
volatility of the chemicals involved in its manufacture would result in high
emissions of volatile organic compounds (VOC) (see Appendix A for pertinent
physical properties). Ethylene dichloride also constitutes a large portion of
the emissions from both direct chlorination and oxychlorination of ethylene, the
two commercial processes for its manufacture.
B. USAGE AND GROWTH
The end uses and expected growth rates for ethylene dichloride are given in
Table II-l. The predominant use is as an intermediate in the production of vinyl
chloride monomer (VCM); approximately 96% of the VCM produced in 1979 was made
from ethylene dichloride. A large portion of the remaining ethylene dichloride
is used in production of chlorinated solvents.
The domestic ethylene dichloride capacity for 1978 is reported to be about
6,920,000 Mg/yr.2 Production was reported to be about 4,990,000 Mg in 1978, or
about 70% of capacity. Based on a projected growth rate of 5 to 6.5%, production
will utilize 92 to 100% of the 1978 capacity by 1982. Several companies are
either completing construction and startup of new VCM plants or are planning new
VCM capacity, ' which usually must include additional ethylene dichloride
capacity. Ethylene dichloride for sale must come from direct chlorination of
ethylene unless a supply of hydrogen chloride (HCl) is available as feed for the
oxychlorination process. Conversely, unless the HCl produced as a by-product
during the cracking of ethylene dichloride to VCM has another use, it is used as
feed for the oxychlorination process.
C. DOMESTIC PRODUCERS
There were 12 producers operating 18 ethylene dichloride plants in the United
States in 1979. Table II-21'2'4'5 lists the producers, locations, and capacities,-
Fig. II-l shows plant locations.
-------
II-2
Table II-l. Ethylene Bichloride Usage and Growth*
End Use
Vinyl chloride
1,1, 1-Trichloroethane
Trichloroethylene
Perchloroethylene
E t hy le ne ami ne s
Vinylidene chloride
Lead scavanger
Production for
1978
87
4
2
2
2
1
Average Growth
for 1977—1982
(%/yr)
5.5 - 7.5
4 0 - 5.5
(-2.0) - 3.5
0 - 2.0
(-2.5) - (-3.5)
5.0 - 7.0
(-15.0)
*
See ref 1.
-------
II-3
Table II-2. Ethylene Dichloride Capacity
Plant
ICI
Borden
Conoco
Diamond Shamrock
Diamond Shamrock
Dow
Dow
Dow
Ethyl
Ethyl
Goodrich
PPG
PPG
Shell
Shell
Stauffer
Union Carbide
Union Carbide
Vulcan
Total
Location
Baton Rouge , LA
Geismar, LA
Lake Charles , LA
Deer Park, TX
La Porte, TX
Freeport, TX
Oyster Creek, TX
Plaquemine , LA
Baton Rouge , LA
Houston, TX
Calvert City, KY
Lake Charles , LA
Guayanilla, PR
Deer Park, TX
Nor co , LA
Long Beach, CA
Taft, LA
Texas City, TX
Geismar, LA
Capacity
as of 1979
(Mg/yr)
315,000
225,000b
524,000°
145,000
719,000
726,000
499,000
953,000
318,000
118,000
454,000d
544,000
379,000e
635,000
544,000
154,000
68,000f
68,000f
136,000
7,524,000g
See refs 1,2,4 and 5.
Plant started up in 1977 (see ref 5) .
°Conoco plans to add 318,000 Mg/yr by 1982 (see ref 4).
d
Convent Chemical, a joint venture of Goodrich and Bechtel, is building a
363,000-Mg/yr ethylene dichloride facility near Convent, LA (see ref 4).
Q
Plant is shut down.
Union Carbide is the only producer making ethylene dichloride exclusively by
the direct-chlorination of ethylene process; all other producers use both
the direct-chlorination and the oxychlorination processes (see ref 1).
gGeorgia-Pacific is building a 748,000 Mg/yr ethylene dichloride unit at
Plaquemine, LA, and Formosa Plastics is building an ethylene dichloride unit
with an estimated capacity of 385,000 Mg/yr at Point Comfort, TX.
-------
II-4
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(ID
(12)
(13)
(14)
(15)
(16)
(17)
(18)
Dow Chemical
Dow Chemical
ICI Americas, Inc., Baton Rouge, LA
Borden Chemical Co., Geismar, LA
Conoco Chemicals, Lake Charles, LA
Diamond Shamrock Corp., Deer Park, TX and La Porte, TX
Dow Chemical Co., Freeport, TX
Co., Oyster Creek, TX
Co., Plaquemine, LA
Ethyl Corp., Baton Rouge, LA
Ethyl Corp., Houston, TX
B.F. Goodrich Co., Calvert City, KY
PPG Industries, Inc., Lake Charles, LA
PPG Industries, Inc., Guayanilla, PR
Shell Chemical Co., Deer Park, TX
Shell Chemical Co., Norco, LA
Stauffer Chemical Co., Long Beach, CA
Union Carbide Corp., Taft, LA
Union Carbide Corp., Texas City, TX
Vulcan Materials Co., Geismar, LA
Fig. II-l. Locations of Plants Manufacturing Ethylene Dichloride
-------
II-5
Companies producing EDC are listed below:
1. ICI
About 70% of the EDC capacity is required to operate the VCM facilities at
capacity. The remainder is sold.
2. Borden
All EDC is captively consumed in the manufacture of VCM. The facilities
were started up in 1977.
3. Conoco
All EDC is captively consumed in the manufacture of VCM. The plans are to
4
add 318,000 Mg/yr to their capacity by 1982.
4. Diamond Shamrock
All EDC produced at LaPorte, TX, is consumed in the manufacture of VCM. Some
of the EDC capacity at Deer Park, TX, is required for the perchloroethylene
facilities; the rest of the EDC is sold. '
5. Dow
Approximately 75% of the EDC capacity is used as an intermediate for
capacity production of numerous end products; the remainder is sold.
6. Ethyl
Nearly all the EDC capacity is required as an intermediate for the manu-
facture of various end products.
7. Goodrich
All EDC is captively consumed in VCM production. Goodrich and Bechtel have
agreed on a joint venture to manufacture EDC at a facility near Houston,
TX.
8. PPG
Nearly all EDC is captively consumed in the manufacture of VCM and other
chlorinated hydrocarbons.
-------
II-6
9. Shell
EDC is captively consumed in VCM manufacture.1
10. Stauffer
About 95% of the EDC is consumed in VCM production; the remainder is sold.7
11. Union Carbide
Union Carbide is the only producer making all EDC exclusively by the direct-
chlorination process. About 85% of the EDC capacity is required for operation
of ethylenediamine plants at capacity.
12. Vulcan
A small amount of EDC is consumed in the manufacture of perchloroethylene;
most of it is sold.
-------
II-7
D. REFERENCES*
1. S. A. Cogswell, "Ethylene Dichloride," pp. 651.5031A--651.50331 in Chemical
Economics Handbook, Stanford Research Institute, Menlo Park, CA (February 1979).
2. 1979 Directory of Chemical Producers, United States of America, SRI International,
Menlo Park, CA, p 598 (1979).
3. "Manual of Current Indicators—Supplemental Data," p. 256 in Chemical Economics
Handbook, Stanford Research Institute, Menlo Park, CA (August 1980).
4. "Chemical Profile on Ethylene Dichloride," Chemical Marketing Reporter
217(18), 9 (May 5, 1980).
5. J. A. Key, IT Enviroscience, Inc., Trip Report for Visit to Borden Chemicals,
Geismar, Louisiana, March 2, 1978 (data on file at EPA, ESED, Research Triangle
Park, NC).
6. William R. Taylor, Diamond Shamrock Corp., Cleveland, OH, letter dated Mar. 6,
1979, to EPA.
7. Thomas J. Sayers, Stauffer Chemical Co., Westport, CT, letter dated Feb. 23,
1975, to EPA.
*Usually, when a reference is located at the end of a paragraph, it refers to
the entire paragraph. If another reference relates to certain portions of
that paragraph, that reference number is indicated on the material involved.
When the reference appears on a heading, it refers to all the text covered by
that heading.
-------
III-l
III. PROCESS DESCRIPTION
A. INTRODUCTION
Most of the ethylene dichloride (EDC) produced domestically is used in the pro-
duction of vinyl chloride monomer (VCM) . Three principal steps are involved in
producing VCM: (1) the direct chlorination of ethylene to yield EDC, (2) which
is then cracked to yield VCM plus hydrogen chloride (HC1), and (3) the use of HC1
with oxygen, which may be in the form of air, to oxychlorinate ethylene to pro-
duce additional EDC plus water. These steps constitute the "balanced" process,
so-called because all the HC1 is recycled.
This report is concerned with only the direct-chlorination process and the two
variations of the oxychlorination process for producing ethylene dichloride. Also,
for the model plants discussed in Sect. IV the ratio of EDC produced by direct
chlorination to EDC produced by oxychlorination is fixed because no net HC1 is
produced. In other plants, however, such as one in which HCl is available as a
by-product from other processes, the ratio will be different. One ethylene di-
chloride producer uses only the direct-chlorination process. Previously, ethylene
dichloride was produced as a by-product of ethylene oxide manufacture by the
chlorohydrin process; however, the last domestic producer using that process con-
verted to propylene oxide manufacture in 1970.
B. DIRECT-CHLORINATION AND OXYCHLORINATION (AIR) PROCESSES
Ethylene dichloride is produced by direct chlorination of ethylene by the cata-
lytic reaction
(ethylene) (chlorine) (ethylene dichloride)
Almost all commercial plants now use a ferric chloride catalyst in a liquid-phase
process .
Ethylene dichloride is also produced by oxychlorination of ethylene with hydrogen
chloride and air or oxygen by the following catalytic reaction:
-------
III-2
2CH =CH + 0 + 4HC1 > 2C1CH CH Cl + 2H 0
£* £* £f £* £* £*
(ethylene) (oxygen) (hydrogen (ethylene (water)
chloride) dichloride)
The catalyst is a mixture of copper chloride and other chlorides and the reaction
is carried out in the vapor phase in either a fixed- or fluid-bed reactor.
The typical ethylene dichloride process shown in Fig. III-l begins with ethylene
(Stream 1) being fed by pipeline to both the oxychlorination reactor and the direct-
chlorination reactor. In the oxychlorination reactor the ethylene is mixed with
approximately stoichiometric proportions of anhydrous hydrogen chloride (Stream 2)
and air (Stream 3) at pressures of 140--520 kPa and temperatures of 200—315°C.
The conversion of ethylene to ethylene dichloride in the reactor is virtually com-
plete. The reaction is exothermic, generating more than 230 kJ of heat per mole
of ethylene dichloride produced, and requires efficient heat removal for adequate
2
temperature control.
The products of reaction from the oxychlorination reaction are quenched and cooled
(Stream 4) and then go to a knockout drum. The condensed crude ethylene dichloride
and water (Stream 5) separated by the knockout drum enter a decanter, where the
crude ethylene dichloride is separated from the aqueous phase. The crude ethylene
dichloride (Stream 6) goes to in-process storage, and the aqueous phase (Stream 7)
is recycled to the quench step. Noncondensed material (Stream 8) from the knockout
drum is fed to an absorber, where ethylene dichloride is recovered from the nitrogen
and other inert gases, which are released to the atmosphere (Vent A). Absorbed
ethylene dichloride and the absorbent (Stream 9) enter a stripper that removes
ethylene dichloride overhead (Stream 10), which then goes to crude ethylene dichlo-
ride storage. The stripped absorbent (Stream 11) from the stripper is recycled
to the absorber.
In the direct-chlorination step of the balanced process, ethylene (Stream 1) and
a stoichiometric amount of chlorine (Stream 12) are reacted at a temperature of
38--49°C and at pressures of 69—138 kPa. This process produces 218 kJ/mole (of
2
EDC) of heat that must be removed for proper temperature control.
-------
H
M
I
M
rt
ro
D
ra
D
H-
o
o
H-
H>
Ml
O
pj
a
o
ro
o
o
(D
W
IP I
C-III
-------
III-4
Products (Stream 13) of reaction from the direct-chlorination reactor are cooled,
and the crude ethylene dichloride (Stream 14) is washed with water to remove dis-
solved hydrogen chloride before being transferred (Stream 15) to the in-process
storage. Any inert gas fed with the ethylene or chlorine is released to the atmos-
phere from the cooler (Vent B). The waste wash water (Stream 16) is sent to the
wastewater stripper along with the wastewater (Stream 17) from the oxychlorination
quench area and the wastewater (Stream 18) from the drying column. The overheads
(Stream 19) from the wastewater stripper, which consist of recovered ethylene dichlo-
ride, other chlorinated hydrocarbons, and water, are returned to the process by
adding them to the crude ethylene dichloride (Stream 14) going to the water wash.
Crude ethylene dichloride (Stream 20) from in-process storage goes to the drying
column, where water (Stream 18) is distilled overhead and sent to the wastewater
stripper. The dry crude ethylene dichloride (Stream 21) goes to the heads column,
which removes light ends (Stream 22) for storage and disposal or sale. Bottoms
(Stream 23) from the heads column enter the ethylene dichloride finishing column,
where ethylene dichloride (Stream 24) goes overhead to product storage. The tars
from the ethylene dichloride finishing column (Stream 25) are taken to tar storage
for disposal or sales.
The largest amount of emission is the oxychlorination reaction off-gas from vent A,
because all the nitrogen from the air (Stream 3) fed to the reactor exits the pro-
cess there. This vent also contains all the ethane from the ethylene feed to the
oxychlorination reactor, carbon dioxide and carbon monoxide formed by side reac-
tions, some ethylene dichloride and other chlorinated hydrocarbons not recovered
by the absorber, and a small amount of the absorbent. Other process emissions
are the vent gases from the direct-chlorination cooler (Vent B) and from the
various distillation columns (Vents C).
Storage emission sources (Vents D through G) include in-process storage, product
storage, liquid waste storage, and tar storage. Because ethylene dichloride is
fed by pipeline to the cracking section of a VCM plant and the light ends and tars
are piped to the incinerator, there are no handling emissions from this process
as shown. They will occur, however, when ethylene dichloride or the light ends
or the tars are loaded into tank trucks, tank cars, or barges for shipping to other
sites.
-------
III-5
Fugitive emissions (H) occur when leaks develop in valves or in pump or compressor
seals. When the process pressures are higher than the cooling-water pressure,
ethylene dichloride and other VOC can leak into the cooling water and escape as
fugitive emissions from the cooling tower.
Secondary emissions can occur when wastewater containing VOC is sent to a waste-
water treatment system or lagoon and the VOC are desorbed (I). Another source of
secondary emissions is from the incineration of liquid-waste streams, where VOC
are emitted with the flue gases (Vent J).
DIRECT-CHLORINATION AND OXYCHLORINATION (OXYGEN) PROCESSES
Only two domestic EDC producers use oxygen as the oxidant in the oxychlorination
reactor. The process details are considered to be confidential by both producers.
Although conceptual descriptions of such processes are given in the literature,
it is not known how the processes actually used compare with those described.
One producer has released data showing that the plant is not truly balanced; i.e.,
the ratio of ethylene dichloride from oxychlorination and direct chlorination dif-
fers from that of a balanced plant. However, both producers have direct chlorina-
tion, ethylene dichloride purification and cracking, and VCM purification steps
3 — 6
at the same site, which probably constitute an integrated process.
Figure III-2 shows a typical oxygen-based oxychlorination process as given in the
literature. For a balanced process plant the direct chlorination and purification
steps are the same as those shown in Fig. III-l and therefore are not shown again
in Fig. III-2. Ethylene (Stream 1) is fed in large excess of stoichiometric
requirements, e.g., 2 to 3 times the amount needed to fully consume the hydrogen
chloride (HCl) feed (Stream 2). Oyxgen (Stream 3) is also fed to the reactor,
which may be either a fixed bed or a fluid bed. After passing through the oxy-
chlorination reactor and quench area, the reaction products (Stream 4) go to a
knockout drum, where the condensed crude ethylene dichloride and water (Stream 5)
produced by the oxychlorination reaction are separated from the unreacted ethylene
and the inert gases (Stream 6), e.g., carbon dioxide, carbon monoxide, nitrogen,
argon, and nonreactive hydrocarbons, which enter the reactor as impurities with the
feed streams or are formed during the oxychlorination reaction itself. From the
knockout drums the crude ethylene dichloride and water (Stream 5) go to a decanter,
where wastewater (Stream 7) is separated from the crude ethylene dichloride (Stream
-------
QL.
(BY
\X
(BY PIPE- t
UKIE")
REACTOR
AK10
QUEMCH
AREA
KUOCKQUT
DRUM
CAJJSTIC
SCRUBBER
<£
WATER
DECAK1TEP,
MaOH
FROM DIRECT
STEP
i
H
H
I
cn
TO PURIPICATJQM
STEP
Fig. III-2. Ethylene Dichloride by Oxygen Process, Oxychlorination Step
-------
III-7
which goes to in-process storage as in the air-based process. The wastewater
(Stream 7) is sent to the steam stripper in the direct-chlorination step for
3,4
recovery of dissolved organics.
The vent gases (Stream 6) from the knockout drum go to a caustic scrubber for
removal of hydrogen chloride and carbon dioxide. The purified vent gases (Stream 9)
are then compressed and recycled (Stream 10) to the oxychlorination reactor as
3 4
part of the ethylene feed. '
A small amount of the vent gas (Vent A) from the knockout drum is purged to prevent
buildup of the inert gases entering with the feed streams or formed during the
reaction. '
D. PROCESS VARIATIONS
Although all ethylene dichloride is produced either by direct chlorination of ethylene
or by oxychlorination of ethylene, there are many variations in the reactors, recovery
methods, and purification trains. However, while the general differences are well
known and documented,2"4'7'8 the details are considered to be trade secrets by the
various manufacturers of ethylene dichloride.
The oxychlorination reactor may be either a tubular fixed-bed type with the cat-
alyst inside the tubes and the coolant in the shell or a fluid-bed type with
internal cooling coils. The reactor effluent may be cooled by indirect heat
exchange to condense the ethylene dichloride. In one process chlorine is added
to the vent gases, which are then passed through one or more catalytic reactors
for removal of unreacted ethylene by conversion to ethylene dichloride. When
absorption/stripping is used for recovery of ethylene dichloride from the vent
gases, the absorbent may be either water or an aromatic solvent. Refrigerated
vent condensers may be used to cool the oxychlorination vent gases to as low as
ry _ — r T Q
-23°C for recovery of chlorinated hydrocarbons.
The direct chlorination of ethylene with chlorine may be carried out either in the
vapor phase or in the liquid phase. The catalyst may be a metallic chloride such
as ferric, aluminum, copper, or antimony chloride; ferric chloride in a liquid-phase
reactor is used by almost all commercial plants. The vapors may be condensed by
water-cooled and/or refrigerated condensers or they may be absorbed in water or
128
dilute caustic. ' '
-------
III-8
The crude ethylene dichloride from the oxychlorination step may be combined with
that from the direct chlorination and washed with water or caustic or both. The
crude ethylene dichloride may be used without purification in many applications; in
other applications it may be purified and may include recycled EDC from the VCM
C '-I Q
purification step. ' '
Production of other chlorinated hydrocarbons, such as 1,1,1-trichloroethane and
1,1,2-trichloroethane, may be integrated with ethylene dichloride--vinyl chloride
g
plants. Vent gas streams from the direct-chlorination step or other processing
units may be recycled to the oxychlorination reactor as part of the feed to utilize
L-
7
7 10
the raw materials contained in the streams. ' These recycle streams or the ethyl-
ene, hydrogen chloride, and chlorine feeds may contain impurities, such as methane,
that will exit the process in the vent gases. The light chlorinated hydrocarbons
recovered in the purification step may be used as feed to perchloroethylene and
carbon tetrachloride plants or may be further purified for recovery of specific
chlorinated hydrocarbons. The heavy chlorinated hydrocarbons may also be processed
5 7
for recovery of some of the chlorinated hydrocarbons. '
-------
III-9
E. REFERENCES*
1. J. L. Blackford, "Ethylene Bichloride," p. 651.5932A in Chemical Economics
Handbook, Stanford Research Institute, Menlo Park, CA (November 1975).
2. R. G. Bellamy and W. A. Schwartz, Houdry Div., Air Products and Chemicals,
Engineering and Cost Study of Air Pollution Control for the Petrochemical
Industry. Volume 8: Vinyl Chloride Manufacture by the Balanced Process,
EPA-450/3-73-006-h, Research Triangle Park, NC (July 1975).
3. W. E. Wimer and R. E. Feathers, "Oxygen Gives Low Cost VCM," Hydrocarbon
Processing 55(3), 81--84 (1976).
4. P. Reich, "Air or Oxygen for VCM?" Hydrocarbon Processing 55(3), 85--S9
(1976). HI
5. Responses to EPA requests for information on emissions from ethylene dichloride
and vinyl choride production facilities; see Appendix E.
6. J. A. Key, IT Enviroscience, Inc., Trip Report for Visit to Dow Chemical, USA,
Freeport, TX, Sept. 20, 1977 (on file at EPA, ESED, Research Triangle Park, NC).
7. W. A. Schwartz et al., Houdry Div., Air Products and Chemicals, Engineering and
Cost Study of Air Pollution Control for the Petrochemical Industry. Volume 3:
Ethylene Dichloride Manufacture by Oxychlorination, EPA-450/3-73-006-C, Research
Triangle Park, NC (November 1974).
8. J. W. Pervier et al., Houdry Div., Air Products and Chemicals, Survey Reports on
Atmospheric Emissions from the Petrochemical Industry, Volume II, EPA-450/3-73-005-b,
Research Triangle Park, NC (April 1974).
9- Standard Support and Environmental Impact Statement: Emission Standard for
Vinyl Chloride, EPA-450/2-75-009, Research Triangle Park, NC (October 1975).
10. W. M. Reiter, Allied Chemical Corporation, letter dated May 16, 1978, in response
to EPA's request for information on emission data on ethylene dichloride production
facilities.
*Usually, when a reference is located at the end of a paragraph, it refers to
the entire paragraph. If another reference relates to certain portions of
that paragraph, that reference number is indicated on the material involved.
When the reference appears on a heading, it refers to all the text covered by
that heading.
-------
IV-1
IV. EMISSIONS
Emissions in this report are usually identified in terms of volatile organic
compounds (VOC). VOC are currently considered by the EPA to be those of a
large group of organic chemicals, most of which, when emitted to the atmosphere,
participate in photochemical reactions producing ozone. A relatively small number
of organic chemicals have low or negligible photochemical reactivity. However,
many of these organic chemicals are of concern and may be subject to regulation
by EPA under Section 111 or 112 of the Clean Air Act since there are associated
health or welfare impacts other than those related to ozone formation. It should
be noted that although ethane is included in VOC emission totals in this report,
it does not, based on current research data, participate in ozone-forming reac-
tions to an appreciable extent.
A. DIRECT-CHLORINATION AND OXYCHLORINATION (AIR) PROCESSES
1. Model Plant
The model plant* for the balanced process (Fig. III-l) has an ethylene dichlo-
ride (ECD) capacity of 400,000 Mg/yr, based on 8760 hr of operation annually,-**
215,000 Mg/yr is produced by direct chlorination and 185,000 Mg/yr by oxychlori-
nation with air. A small quantity (8000 Mg/yr) of liquid-waste chlorinated hydro-
carbons is produced and then burned in a liquid-waste incinerator. These liquid
wastes could be used or sold. If there is no demand, they would be burned.
The model plant is typical of several existing ethylene dichloride plants.1
Typical in-process, product, and waste by-product storage-tank capacities are
estimated for the 400,000-Mg/yr plant. The storage-tank parameters are given
in Sect. IV.A.2.d, and estimates of potential fugitive emission sources are given
in Sect. IV.A.2.e. Characteristics of the model plant that are important in
air-dispersion modeling are given in Table B-l in Appendix B.
*See p 1-2 for a discussion of model plants.
**Process downtime is normally expected to range from 5 to 15%. If the hourly
production rate remains constant, the annual VOC emissions will be correspondingly
reduced. Control devices will usually operate on the same cycle as the process.
From the standpoint cost-effectiveness calculations, the error introduced
by assuming continuous operation is negligible.
-------
IV-2
Process emissions from the model plants are based on emission data included in
trip reports, responses to EPA letters requesting information from sites not
1 2
visited, and the Houdry reports. ' Nonconfidential information from emission
inventory questionnaires submitted to the Texas Air Control Board and the Louisiana
Air Control Commission was also used as an emission data source. Literature
sources, such as the SRI Chemical Economics Handbook and the Kirk-Othmer
Encyclopedia of Chemical Technology, were utilized to gain a better under-
standing of process unit operations and process chemistry. The data on emissions
from individual distillation colums were generally not available and the data
on distillation emissions that were given showed wide variations.
2. Sources and Emissions
Emission rates and sources for the balanced process based on air are summarized
in Table IV-1.
a. Oxychlorination Vent -- The oxychlorination vent gas (Vent A, Fig. III-l) contains
nitrogen and unreacted oxygen from the air fed to the reactor; ethane and unreacted
ethylene from the ethylene feed; and the ethylene dichloride product, other chlori-
nated hydrocarbons, and carbon oxides produced in the reactor and not removed
from the vent gases in the absorber. Table IV-2 gives the composition of this
stream based on an average of data from several sources but is not representative
of actual data from any specific plant or process. The data points show such
wide scatter that no composition can be found that is typical for either fluid-bed
or fixed-bed reactors. It appears that operating conditions may influence the
vent gas composition more than reactor configuration. Although there are more
inert gases (nitrogen, oxygen, and carbon oxides) in the fluid-bed vent gas and
more total vent gas per kg of ethylene dichloride produced than for the fixed-bed
case, for both reactors the ratios of total VOC and EDC emitted per kg of EDC
produced have the same ranges and averages. The ethane content of the vent gas
from the model plant is calculated based on ethylene containing 0.1% ethane and
on ethane being neither consumed nor produced in the oxychlorination reactor.
Only inert gases are contained in the hydrogen chloride feed used in the model
plant; therefore methane does not appear in the oxychlorination vent gas.
b. Direct-Chlorination Vent - The vent gases from the direct-chlorination step
(Vent B, Fig. III-l) are primarily the inert gases from the ethylene and chlorine
-------
IV-3
Table IV-1. Uncontrolled Emissions of EDC and Total VOC from Model Plants
Emissions
Vent or Sourc
Designatior
Emission Source (Figs. III.-lj
Oxychlorination vent
Air process
Oxygen process
Direct-chlorination vent
Column vents
Storage vents
In-process
Product
Liquid wast«
Tar
Fugitive
Secondary
Wastewater treatment
Incinerator
Total for air process
Total for oxygen process
A
Ab
B
C
D
E
F
c.
\3
H
I
J
:e Ratio3 (g/kg)
i —
2) EDC
3.24 .
0.462
1.08
3.00
0.0149
0.0733
0.265
0.0181
7.7
4.9
Total VOC
7.17
9.39
2.84
13.0
0.0149
0.0733
0.0295
0.000818
0.533
0.0272
0.190
24
26
Rate (kg/hr)
EDC
148
21.1
49.1
137
0.679
3.34
12.1
0.829
350
220
Total VOC
327
429
130
594
0.679
3.34
1.35
0.0373
24.3
1.24
8.68
1100
1200
ag of emission per kg of EDC produced by balanced process.
bSee Fig. III-2 for this vent source; see Fig. III-l for all others.
-------
IV-4
Table IV-2. Composition of Model-Plant
Oxychlorination (Air) Vent Gas
Component
Ethylene dichloride
Ethylene
Ethane
b
Other VOC
Nitrogen
Oxygen
Carbon dioxide
Carbon monoxide
Total
Composition
(wt %)
0.81
0.61
0.03
0.34
89.24
5.33
2.79
0.85
100.00
Emission
Ratio (g/kg)
7.0
5.3
0.3
2.9
770.1
46.0
24.1
7.3
863.0
g of emission per kg of ethylene dichloride produced by Oxychlorination.
bEthyl chloride, VCM, and other chlorinated hydrocarbons. VCM concen-
tration meets current EPA emission standards.
-------
IV-5
feeds, unreacted ethylene, and ethylene dichloride not condensed in the cooler.
The ethylene dichloride in the vent gases is estimated to be 2 g/kg of the ethylene
dichloride produced from the direct-chlorination step. The ethylene feed to
the model plant contains 0.1% ethane, which exits with the vent gases along with
the unreacted ethylene. The chlorine to the model-plant reactor consists of 0.5%
inert gases, or 3.65 g/kg of direct-chlorination product, which is a significant
portion of the vent emissions.
c. Column Vents — The vent gases from the EDC stripper, the wastewater stripper,
the drying column, the heads column, and the EDC finishing column (Vents C,
Fig. III-l) are the noncondensables that are dissolved in the feed to the columns,
the VOC that are not condensed, and, for the columns operated under vacuum, the
air that leaks into the column and is removed by the vacuum jet systems. An
estimate was made of the quantity of these emissions, since the available data
1 2
are scarce and vary widely. '
d. Storage and Handling Emissions -- Emissions result from the storage of ethylene
dichloride, in-process, and liquid-waste streams. Sources for the model plant
are shown in Fig. III-l (Sources D through G). Storage tank parameters for the
model plant are given in Table IV-3. The calculated emissions in Table IV-1
are based on fixed-roof tanks, half full, and an 11°C diurnal temperature varia-
tion. Emission equations from AP-42 were used with one modification. The breath-
ing losses were divided by 4 to account for recent evidence that indicates the
3 4
AP-42 breathing-loss equation overpredicts emissions. '
No handling emissions occur in the model plant, as all raw materials, product,
and waste by-products are transported by pipeline. This may not be the case in
existing plants, where loading and unloading operations could result in addi-
tional emissions.
e. Fugitive Emissions -- Process pumps, process valves, and pressure relief devices
are potential sources of fugitive emissions (Source H). The model plant is esti-
mated to have 42 pumps handling VOC, 38 of which handle ethylene dichloride or
other light liquids. There are an estimated 1200 process valves and 40 pressure
relief devices in VOC service, with 200 process valves and 40 pressure relief
-------
IV-6
Table IV-3. Model-Plant Storage Tank Data
Storage Tank
In-process storage
Liquid-waste storage
Tar storage
Product
Contents
Crude EDC
Light ends
Heavy ends
EDC
No. of
Tanks
Required
1
1
1
1
Tank
Size
1140
380
380
3800
Turnovers
(Per Year)
6*
8
8
12*
Bulk
Temperature
27
27
27
27
*These tanks operate at approximately constant level, and the number of turnovers
indicated is an attempt to account for slight level variations.
-------
IV-7
devices in gas/vapor service and 900 process valves in ethylene dichloride or
other light-liquid service. The fugitive-emission factors from Appendix C were
applied to these estimates, and the totals are shown in Table IV-1 as uncontrolled
fugitive emissions.
f- Secondary Emissions -- Secondary emissions can result from the handling and dis-
posal of process waste-liquid streams. Two potential sources (I and J) are indi-
cated in Fig. III-l for the model plant.
The secondary emissions from wastewater treatment (Source I) were estimated by
procedures that are discussed in an EPA report. An estimate of wastewater com-
position and flow rate was made, based on data received from ethylene dichloride
producers. A Henry1s-law constant was then calculated for the vapor-liquid
system under consideration, and the emission rate was estimated by comparison
with information given in existing literature, such as an article by Thibodeaux.
This emission rate is shown in Table IV-1.
The secondary emissions of total VOC in the flue gases from the liquid chlori-
nated hydrocarbon incinerator (Source J) were estimated as 1% of feed. Infor-
mation on these emissions is not presently available, and so the estimate was
based on 99% destruction of the liquid feed. Higher than normal temperatures
and residence times are required to destroy 99% or more of a liquid chlorinated
hydrocarbon feed that contains no salts or solids except for a small amount of
finely divided carbon. Before the flue gases are vented to the atmosphere, they
are normally sent first to absorbers for recovery of HC1 and then to a dilute
caustic scrubber to remove unrecovered HC1 and any chlorine formed in the incine-
ration. The dilute recovered HC1 may be concentrated to anhydrous HC1, which
can be used as feed to the oxychlorination reactor.
B. DIRECT-CHLORINATION AND OXYCHLORINATION (OXYGEN) PROCESSES
1. Model Plant
In the model-plant oxychlorination (oxygen) process (Fig. III-2) for producing
ethylene dichloride, oxygen is fed to the reactor instead of air. All the capac-
ities for both model plants are identical, i.e., 400,000 Mg/yr of ethylene
dichloride from the plant, with 185,000 Mg/yr being produced by the oxychlori-
-------
IV-8
nation step, etc. Figure III-2 shows only the oxychlorination step. Storage
tank requirements and estimates of potential fugitive emission sources and
secondary emission sources are also the same as for the air process. Character-
istics of the model plant that are important in air dispersion modeling are
given in Table B-2 in Appendix B.
2.. Sources and Emissions
Emission rates and sources for the balanced ethylene dichloride process based
on oxygen are summarized in Table IV-1.
a- Oxychlorination Vent -- The oxychlorination vent gas (Vent A, Fig. III-2) acts
as a purge stream to prevent buildup of impurities in the recycle stream (Stream 6,
Fig. III-2). These impurities are the carbon oxides, nitrogen, argon, or nonreactive
hydrocarbons that enter the reactor with the feed streams or that are formed
during the oxychorination reaction itself. Table IV-4 gives the composition of
this stream based on an average of data from oxygen based processes1 but is not
representative of actual data from any specific process. The ethane content of
the vent gas from the oxygen-based model plant is calculated based on ethylene
containing 0.1% ethane and on no ethane being consumed or produced in the oxy-
chlorination reactor. Since the ethylene and hydrogen chloride feed to the model
plant contains no methane, no methane is present in these vent gases.
b- Other Emissions -- All other emissions from the the oxygen process are identical
to those from the process based on air and are discussed in Sect. IV.A.2.
C. CURRENT EMISSIONS
An estimate of the 1978 emissions from the industry is 11,000 Mg/yr of ethylene
dichloride and 34,000 Mg/yr of total VOC, based on an estimated 1978 level of
ethylene dichloride production of 4,900,000 Mg/yr obtained by applying a 5% growth
rate to the reported 1977 production of 4,679,000 Mg/yr.7 These emission esti-
mates are based on engineering judgement and data from individual ethylene
dichloride producers, state and local emission control agencies, and the open
literature. The following individual estimated projections were made:
-------
IV-9
Table IV-4. Composition of Model-Plant
Oxychlorination (Oxygen) Vent Gas
Component
Ethylene dichloride
Ethylene
Ethane
b
Other VOC
Nitrogen
Oxygen
Carbon dioxide
Carbon monoxide
Total
Composition
(wt %)
1.
27.
0.
1.
15.
3.
45.
4.
100.
5
6
5
5
3
1
9
6
0
Emission
Ratio (g/kg)
1
18
0.3
1
10
2
30
3
65.3
a .. j • -u-i • ,3 ,q^u >,i'
Ethyl chloride, VCM, and other chlorinated hydrocarbons.
-------
IV-10
1978 Emissions (Mq/yr)
Source EDC Total VOC
Process 10,600 33,200
Storage and handling 280 310
Fugitive 60 120
Secondary 90 600
Total (rounded) 11,000 34,000
-------
IV-11
D. REFERENCES*
1. Responses to EPA requests for information on ethylene dichloride emissions; see
Appendix E.
2. W. A. Schwartz e_t al., Houdry Div., Air Products and Chemicals, Engineering and
Cost Study of Air Pollution Control for the Petrochemical Industry. Volume 3:
Ethylene Dichloride Manufacture by Oxychlorination, EPA-450/3-73-006-C, Research
Triangle Park, NC (November 1974).
3. C. C. Masser, "Storage of Petroleum Liquids," Sect. 4.3 in Compilation of Air
Pollutant Emission Factors, AP-42, Part A, 3d ed. (April 1977).
4. E. C. Pulaski, TRW, Inc., letter dated May 30, 1079, to Richard Burr, EPA.
5. J. J. Cudahy and R. L. Standifer, IT Enviroscience, Inc., Secondary Emissions
(June 1980) (EPA/ESED report. Research Triangle Park, NC).
6. L. J. Thibodeaux, "Air Stripping of Organics from Wastewater. A Compendium,"
pp. 358--37S in The Proceedings of the Second National Conference on Complete
Watereuse. Water's Interface with Energy, Air and Solids, Chicago, IL, May 4--8,
1975, sponsored by AIChE and EPA Technology Transfer.
7. "Manual of Current Indicators—Supplemental Data," p 219 in Chemical Economics
Handbook, Stanford Research Institute, Menlo Park, CA (June 1978).
*Usually, when a reference is located at the end of a paragraph, it refers to
the entire paragraph. If another reference relates to certain portions of
that paragraph, that reference number is indicated on the material involved.
When the reference appears on a heading, it refers to all the text covered by
that heading.
-------
V-l
V. APPLICABLE CONTROL SYSTEMS
A. DIRECT-CHLORINATION AND OXYCHLORINATION (AIR) PROCESSES
1. Oxychlorination Vent
The gases from the oxychlorination vent can be thermally oxidized to effectively
control the ethylene dichloride (EDC) and VOC in them. Because of the large
percentage of nitrogen and carbon dioxide in the vent gases, supplemental fuel
must be added for proper combustion. The flue gases from the thermal oxidation
of chlorine containing compounds will contain hydrogen chloride (HCl) and a small
amount of chlorine, depending on operating temperature, that must be removed
before the flue gases are discharged to the atmosphere. The model-plant thermal
oxidizer operates at 1200°C and a residence time of 0.75 sec and has a quench
chamber with water sprays to remove the HCl and a tail-gas scrubber to remove
any remaining HCl and any chlorine before the flue gases are discharged from
the stack. The water from the quench chamber and tail-gas scrubber is neutra-
lized with caustic soda to control the pH of the system and is then recycled.
A purge stream to waste treatment is required to prevent a buildup of dissolved
solids.
With a properly designed and operated thermal oxidizer a reduction of 99.9% can
be achieved in ethylene dichloride and total VOC emissions. This reduction was
used for calculation of the controlled emissions from the thermal oxidizer that
originated in the oxychlorination vent (see Table V-l). Data to support the
model-plant thermal oxidizer operating conditions are presented in an EPA report
on emission control systems.
Heat recovery from the thermal oxidizer flue gases can be used to produce steam
to provide a credit. Experience with thermal oxidation and heat recovery of
vent gases containing chlorinated hydrocarbons is limited but has revealed several
problems. The flue gases are corrosive at some temperature conditions. The
thermal oxidizer and heat recovery equipment must be operated carefully to prevent
the occurrence of the corrosive conditions, especially on startup and shutdown
of the unit. One indication of the severity of these problems is the instal-
lation by Diamond Shamrock of two parallel, full-capacity, thermal oxidizer
systems with heat recovery in their new VCM plant to ensure an on-stream factor
of greater than 98%.
-------
Table V-l. EDC and Total VOC Controlled Emissions for Model Plants
Emissions
Vent or Source
Designation
Emission Source (Figs . III-l, 2)
Oxychlorination
vent
Air process
Oxygen process
Direct-chlorina-
tion vent
Column vents
Storage vents
In-process
Product
Liquid waste
Tar
Fugitive
Secondary
Wastewater
treatment
Incinerator
A
Ab
B
C
D
E
F
G
H
I
J
Total for air process
Total for oxygen
process
Control Device
or Technique
Thermal oxidizer
Thermal oxidizer
Thermal oxidizer
Thermal oxidizer
Refrigerated condenser
Refrigerated condenser
Refrigerated condenser
None
Detection and correction
of major leaks
None
Change operating
conditions
Emission
Reduction —
99.9 0
99.9 0
99.9 0
99.9 0
85 0
85 0
82
72 0
0
100
0
0
Ratio
EDC
.00324
.000462
.00108
.00300
.00223
.0110
.0743
.0181
(g/kg)a
Total VOC
0
0
0
0
0
0
0
0
0
0
.00717
.00939
.00284
.0130
.00223
.0110
.'00525
.000818
.149
.0272
0
0
0
0
0
0
3
0
Rate
EDC
.148
.0211
.0491
.137
.102
.502
.39
.829
(kg/hr)
Total VOC
0
0
0
0
0
0
0
0
6
1
.327
.429
.130
.594
.102
.502
.240
.0373
.79
.24
Not detectable
.11
.11
0
0
.22
.22
5
5
.2
.0
10
10
of emission per kg of EDC produced by balanced process.
DSee Fig. III-2 for this source; see Fig. III-l for all other sources.
-------
V-3
Two thermal oxidizers for the direct-chlorination and oxychlorination (air) model
plant were studied: one with heat recovery to produce steam and one without
heat recovery. Both cases have the same emission reduction efficiency, but differ
in the size of the quench chamber, caustic scrubber, fan, and pumps because of
the different flue-gas temperatures to the quench chamber that result in different
flue gas volumes to be quenched and scrubbed and in different amounts of water
that are evaporated.
Several other alternative thermal oxidizer configurations are possible, both
with and without heat recovery. An acid scrubber may be used instead of a water
quench to recover dilute hydrochloric acid, which may be used in other processes
for its acidity or may be neutralized with a cheaper base than caustic soda.
Other systems may be used to recover hydrochloric acid at higher concentrations,
as well as anhydrous hydrogen chloride. ' The thermal oxidizer may be designed
to burn both vent gases and liquid chlorinated by-products.
Catalytic oxidation is also used to control emissions from an oxychlorination
vent. The unit reportedly does remove carbon monoxide and ethylene with better
than 99.7% reduction,- however, it removes less than 75% of the ethylene dichloride
and less than 60% of the VCM, with 100 ppm of ethylene dichloride and 8 ppm of
VCM remaining in the stack gases.
Another device that reduces the ethylene in the oxychlorination vent gases is a
"post" reactor, where chlorine is added to chlorinate the residual ethylene to
ethylene dichloride. Reportedly complete ethylene conversion is obtained, with
the residual concentration in the vent gas being as low as 10 ppm of ethylene.
Data from a plant using this technology show only 0.02 wt % of ethylene but
0.75 wt % of ethylene dichloride and 2 wt % of total VOC in the vent gas after
o
it has been refrigerated to subzero temperature and then scrubbed with water.
Other devices, such as refrigerated vent condensers and hydrocarbon or chilled
water absorbers, do remove some ethylene dichloride and total VOC from the vent
Q
gas; however, they allow significant quantities to go to the atmosphere.
-------
V-4
2. Direct-Chlorination Vent
The emissions from the direct-chlorination vent can be controlled by piping them
to the thermal oxidizer used for controlling the oxychlorination vent gas as
discussed in Sect. A.I or to a vapor and liquid thermal oxidizer serving other
8
processing units. A reduction of 99.9% was used in the calculations of the
controlled emissions from the thermal oxidizer that originate in the direct-
chlorination vent (see Table V-l).
Other devices that may be used to control the emissions from the direct-chlori-
nation vent are refrigerated vent condensers, scrubbers, and flares, or a com-
bination of these, depending on the composition of the vent gases. If properly
designed, a refrigerated vent condenser is effective for removal of ethylene
dichloride (approximately 96% if the vent gases are cooled from 35°C to -26°C
at 240 kPa), although the unreacted ethylene and ethane will remain. Scrubbers
may absorb some ethylene dichloride depending on the operating conditions, but
are primarily installed for removal of hydrogen chloride and unreacted chlorine.8
3. Column Vents
The emissions from the column vents can also be effectively controlled by piping
them to the thermal oxidizer used for controlling the emissions from the oxy-
chlorination and direct-chlorination vents or to a vapor and liquid thermal oxi-
dizer serving other processing units.1'3 A reduction of 99.9% was used in the
calculations of the controlled emissions from the thermal oxidizer that originated
in the column vents (see Table V-l).
The same devices discussed above for the direct-chlorination vent are used to
control the gases from the column vents and the same conditions apply to their
use and effectiveness. These emissions are caused by inert gases that are dis-
solved in the column feeds and that leak into the vacuum columns, and the quan-
O
tity varies widely. The amount of these inert gases can have a considerable
impact on the reduction efficiency of a refrigerated vent condenser, as discussed
in Sect. A-2.
4. Storage Vents
According to information received from companies producing ethylene dichloride,
the crude ethylene dichloride, the product ethylene dichloride, the lights, and
-------
V-5
the heavies are stored in fixed-roof tanks. Often the crude ethylene dichloride
is stored under a water layer, which will reduce the emissions somewhat. A
nitrogen blanket is sometimes employed to keep the product ethylene dichloride
dry. Emissions are controlled by using refrigerated vent condensers or by piping
Q
the storage tank vents to a thermal oxidizer.
The emissions from the model-plant storage tanks are controlled by use of refri-
gerated vent condensers except for the tar storage tank, which is uncontrolled.
9
Reportedly no materials for floating-roof seals are available for use with EDC.
Options for control of storage emissions are covered in another EPA report.
The controlled storage emissions were estimated based on vent condensers operating
at -10°C and on recovery of 85% of the EDC from the vents on the in-process storage
tanks and on the product storage tanks. An estimated 82% recovery is calculated
for the liquid-waste storage tank (see Table V-l).
5. Fugitive Emissions
Controls for fugitive emissions from the synthetic organic chemicals manufac-
turing industry are discussed in a separate EPA document. Emissions from pumps,
process valves, and pressure relief devices can be controlled by an appropriate
leak-detection system and with repair and maintenance as needed. Controlled
fugitive emissions were calculated with the appropriate factors given in Appendix C
and are included in Table V-l.
6. Secondary Emissions
a. Wastewater Treatment -- Calculations based on estimated wastewater flow rates
and compositions for the model plant indicate that the emissions from the waste-
water treatment are relatively small. No control system has been identified
for the model plant.
b. Liquid Chlorinated Hydrocarbon Incinerator -- Control of the secondary emis-
sions from the liquid chlorinated hydrocarbon incinerator consists of changing
the incinerator operating conditions. Data on the relationship of emissions to
operating conditions are not available at this time. Some information indicates
-------
V-6
that higher temperatures and longer residence times are probably helpful in re-
ducing these secondary emissions. ' — Levels of organic chlorides in the
flue gases from the liquid chlorinated hydrocarbon incinerators have been reported
to be none and 30 ppm by weight. ' The controlled secondary emissions from
the model-plant liquid chlorinated hydrocarbon incinerator are estimated to be
nondetectable, as indicated in Table V-l.
B. DIRECT-CHLORINATION AND OXYCHLORINATION (OXYGEN) PROCESSES
1. Oxychlorination Vent
The vent gases from the oxychlorination vent when oxygen is used as the feed
contain much less nitrogen than when air is used and can support combustion with
little or no supplemental fuel required. An emission reduction of 99.9% was
used to calculate the controlled emissions from the thermal oxidizer that origi-
nated in the model-plant oxychlorination vent (see Table V-l). With a properly
designed and operated thermal oxidizer, a reduction of 99.9% can be achieved in
ethylene dichloride and total VOC emissions. Data to support the operating condi-
tions of 0.75-sec residence time and of 1200°C are presented in another EPA report.
Heat recovery from the thermal oxidizer flue gases can be used to produce steam.
The same problems discussed in Sect. A.I will apply to this case.
2. Other Vents
The control systems and controlled emissions for the model-plant direct-
chlorination vent, column vents, storage vents, fugitive sources, and secondary
sources are the same as for the air process model plant (see Table V-l).
-------
V-7
C. REFERENCES*
1. H. S. Basdekis, IT Enviroscience, Inc., Control Device Evaluation. Thermal
Oxidation Supplement (VOC Containing Halogens or Sulfur) (in preparation for
EPA, ESED, Research Triangle Park, NC).
2. Texas Air Control Board, A Construction Permit...to Diamond Shamrock Chemical
Company Authorizing Construction of Vinyl Chloride Plant...at La Porte, Harris
County, Texas, Permit No. C-3855 (Nov. 2, 1976).
3. Y. H. Kiang, "Controlling Vinyl Chloride Emissions," Chemical Engineering Progress
72(12), 37--41 (1976).
4. C. G. Bertram, "Minimizing Emissions from Vinyl Chloride Plants," Environmental
Science and Technology n(9), 864--86S (1977).
5. J. A. Key, IT Enviroscience, Inc., Trip Report for Visit to Borden Chemical, Geismar,
Louisiana, March 2, 1978 (on file at EPA, ESED, Research Triangle Park, NC).
6. W. R. Taylor, Diamond Shamrock Corporation, Deer Park, TX, letter dated
Oct. 3, 1977, to EPA in response to EPA request for information on the catalytic
oxidation unit.
7. P. Reich, "Air or Oxygen for VCM?" Hydrocarbon Processing 56(3), 85--S9 (1976).
8. Responses to EPA requests for information on ethylene dichloride emissions,- see
Appendix E.
9. F. C. Dehn, PPG Industries, Inc., letter dated Mar. 12, 1979, to EPA with
comments on the draft report on ethylene dichloride.
10. D. G. Erikson, IT Enviroscience, Inc., Storage and Handling (in preparation
for EPA, ESED, Research Triangle Park, NC).
11. D. G. Erikson, IT Enviroscience, Inc., Fugitive Emissions (in preparation for
EPA, ESED, Research Triangle Park, NC).
12. S. B. Farbstein and J. Elder, Energy Conservation in the Chemical Industry
Through New Process Development -- The B. F. Goodrich Catoxid Process, paper
presented before the Federal Energy Administration Project Independence
Hearing, San Francisco, CA, Oct. 7, 1974.
13. R. E. Van Ingen, Shell Oil Company, Norco, LA, letter dated Dec. 6, 1974, to
EPA in response to EPA request for information on vinyl chloride monomer operations.
14. T. T. Shen et al., "Incineration of Toxic Chemical Wastes," Pollution Engineering
10(10), 45--50 (1978).
-------
V-8
15. J. A. Mullins, Shell Oil Company, Deer Park, TX, letter dated June 22, 1978,
to EPA in response to EPA request for information on ethylene dichloride manufacture.
16. J. A. Key, IT Enviroscience, Inc., Trip Report for Visit to Dow Chemical, U.S.A.
Oyster Creek Division, Freeport, TX, September 20, 1977 (on file at EPA, ESED,
Research Triangle Park, NC).
*Usually, when a reference is located at the end of a paragraph, it refers to
the entire paragraph. If another reference relates to certain portions of
that paragraph, that reference number is indicated on the material involved.
When the reference appears on a heading, it refers to all the text covered by
that heading.
-------
VI-1
VI. IMPACT ANALYSIS
A. ENVIRONMENTAL AND ENERGY IMPACTS
1. Direct-Chlorination and Oxychlorination (Air) Processes
Table VI-1 shows the environmental impact of reducing the ethylene dichloride
(EDC) and VOC emissions by application of the indicated control systems to the
air process model plant. Use of these control devices or techniques results in
the reduction of EDC emissions by 3030 Mg/yr and total VOC emissions by 9460 Mg/yr
for the model plant.
a. Process Vents -- The thermal oxidizer used for control of emissions from vents A
[oxychlorination (air)], B (direct chlorination), and C (column vents) (Fig. III-l)
reduces the air process model plant EDC emissions by 2900 Mg/yr and total VOC
emissions by 9200 Mg/yr.
The thermal oxidizer uses natural gas as supplemental fuel and electric power
for the blowers, pumps, lighting, and instruments. The total energy required
to operate the thermal oxidizer for the air process model plant is approximately
26 GJ/hr. If heat recovery equipment is installed and approximately 70% of the
available energy from the combustion gases is recovered as steam, the amount of
steam produced will be about 66 GJ/hr. Since a balanced VCM plant consumes a
substantial quantity of steam above that produced in the oxychlorination reactor
12
system, this steam can often be utilized on-site. ' Because the potential exists
for some companies to have excess steam on-site, it may not be practical for
all companies to utilize the heat recovery option.
The combustion of chlorinated compounds in the thermal oxidizer produces hydrogen
chloride (HC1) and free chlorine, which leave in the flue gases. In the removal
and neutralization of these acid gases by the model plant's quench chamber, tail
gas scrubber, and neutralization sump, 7600 Mg of salt in dilute solution is
produced annually. Plants located near the ocean can dispose of this salt solution
without major problems. Others may find it more economical to use alternative
systems for removal of HCl and chlorine that produce a dilute hydrochloric acid
solution as discussed in Sect. V.
-------
Table VI-1. Environmental Impact of Controlled Ethylene Dichloride for Model Plants
Vent or Source
Emission Reduction
(Mg/yr)
Emission Source
xychlorination vent
Air process
Oxygen process
irect-chlorination vent
olumn vents
torage vents
In-process
Product
Liquid waste
Tar
Fugitive
Secondary
Wastewater treatment
Incinerator
Total for air process
Total for oxygen process
Designation Control Device emission
(Figs III-l 2) or Technique Reduction (%) EDC Total VOC
A
Aa
B
C
D
E
F
G
H
I
J
Thermal oxidizer
Thermal oxidizer
Thermal oxidizer
Thermal oxidizer
Refrigerated condenser
Refrigerated condenser
Refrigerated condenser
None
Detection and correction
of major leaks
None
99.9 1290 2,860
99.9 185 3,750
99.9 430 1,140
99.9 1200 5,190
85 5.06 5.06
85 24.9 24.9
82 9.7 V
72 76.3 153
100 76-0
3030 9,460
1920 10,300
aSee Fig. III-2 for this vent source; see Fig. Ill
-1 for all other sources.
-------
VI-3
b. Other Emissions (Storage, Fugitive, and Secondary) -- Control methods described
for these sources for the model plants are refrigerated vent condensers, repair
of leaking equipment for fugitive emissions, and change of operating conditions
for the liquid-waste incinerator.
Application of these systems results in an EDC emission reduction of 106 Mg/yr
and a VOC emission reduction of 270 Mg/yr for the model plants.
2. Direct-Chlorination and Oxychlorination (Oxygen) Processes
Table VI-1 shows the environmental impact of reducing the EDC and VOC emissions
by application of the indicated control systems to the oxygen-process model plant.
Application of these control devices or techniques results in the reduction of
EDC emissions by 1920 Mg/yr and total VOC emissions by 10,300 Mg/yr for the model
plant.
a. Process Vents -- The thermal oxidizer used for control of emissions from vent A
(Fig. III-2) and vents B and C (Fig. III-l) reduces the model-plant EDC emission
by 1800 Mg/yr and total VOC emissions by 10,000 Mg/yr.
The thermal oxidizer for the model plant does not require supplemental fuel,
because the vent gases from the process vents are self-combustible. The energy
required as electric power for the blowers, pumps, lighting, and instruments is
approximately 0.25 GJ/hr. If heat recovery equipment is installed and approxi-
mately 70% of the available energy from the combustion gases is recovered as
steam, about 34 GJ of steam will be produced per hour.
The removal and neutralization of the acid gases from the thermal oxidizer flue
gases will produce about 5900 Mg/yr of salt from the model plant.
b. Other Emissions (Storage, Fugitive, and Secondary) -- The control methods and
environmental and energy impacts for these sources in the oxygen-process model
plant are identical to those of the air-process model plant; see Sect. VI.A.l.b.
B. CONTROL COST IMPACT
This section gives estimated costs and cost-effectiveness data for control of
ethylene dichloride and total VOC emissions resulting from the production of
-------
VI-4
ethylene dichloride. Details of the model plant (Figs. III-l and III-2) are
given in Sects. Ill and IV. Cost estimate sample calculations are included in
Appendix D.
Capital cost estimates represent the total investment required for purchase and
installation of all equipment and material needed for a complete emission con-
trol system performing as defined for a new plant at a typical location. These
estimates do not include the cost of ethylene dichloride production lost during
installation or startup, research and development, or land acquisition.
Bases for the annual cost estimates for the control alternatives include utilities,
waste disposal, chemicals, operating labor, maintenance supplies and labor, re-
covery credits, capital charges, and miscellaneous recurring costs such as taxes,
insurance, and administrative overhead. The cost factors used are itemized in
Table VI-2.
I. Direct-Chlorination and Oxychlorination (Air) Processes
a- Process Vents -- The estimated installed capital cost of a thermal oxidizer de-
signed to reduce by 99.9% the ethylene dichloride and total VOC from the process
vents in the model plant is $2.1 million (see Table VI-3). If waste heat recovery
is included to reduce the operating cost, the estimated installed capital cost
is $2.7 million. These costs are based on a thermal oxidizer designed for a
residence time of 0.75 sec at 1200°C, completely installed, and includes a quench
chamber, tail gas scrubber, sump, pumps, blower, and stack. The use of heat
recovery reduces the temperature, and therefore the volume, of the flue gases
to the quench and scrubber, which consequently will be smaller.
The process-vent-gas rate varies directly with the production rate; therefore
the capacity of the thermal oxidizer will depend on the capacity of the plant.
Figure VI-1 was plotted to show the variation of installed capital cost of a
thermal oxidizer, with and without heat recovery, versus plant capacity.
To determine the cost effectiveness of a thermal oxidizer, estimates were made
of the direct operating cost, the capital recovery cost, and miscellaneous capital
costs, both with and without heat recovery. The recovery credit was calculated
for the heat recovery case based on recovery of approximately 70% of the energy
-------
VI-5
Table VI-2. Annual Cost Parameters
Operating factor
Operating labor
Fixed costs
Maintenance labor plus
materials, 6%
Capital recovery, 18%
Taxes, insurances,
administration charges, 5%
Utilities
Electric power
Natural gas
Heat recovery credits
(equivalent to natural gas)
Caustic (50% NaOH)
Makeup water
8760 hr/yr
$15/man-hr
29% of installed capital cost
$8.33/GJ ($0.03/kWh)
$1.90/GJ ($2.00/thousand ft3 or
million Btu)
$1.90/GJ ($2.00/million Btu)
$0.11/kg
$0.026/m (104/1000 gal)
Process downtime is normally expected to range from 5 to 15%. If the hourly
rate remians constant, the annual production and annual VOC emissions will be
correspondingly reduced. Control devices will usually operate on the same
cycle as the process. From the standpoint of cost-effectiveness calculations,
the error introduced by assuming continuous operation is negligible.
Based on 10.-year life and 12% interest.
-------
Table VI-3. Emission Control Cost Estimates for
Ethylene Dichloride Model Plants
Control
Total
Installed
Capital
Cost
Annual
Gross
Annual
Operating Costs
Recovery
Credits
Direct-Chlorination and
Thermal oxidizer
With heat recovery
Without heat recovery
Thermal oxidizer
With heat recovery
without heat recovery
$2,700,000
2,100,000
$1,750,000
1,400,000
(A)
Net
Annual
Emission
(B)
Reduction
EDC Total VOC
(Mg/yr) (Mg/yr) (%)
Oxychlorination (Air)
$4,080,000 $1,100,000 $2,980,000
3,910,000 0 3,910,000
Direct-Chlorination and Oxychlorination
$2,960,000
2,860,000
$ 560,000
0
$2,400,000
2,860,000
2,
2,
(Oxygen)
1,
1,
Processes
900 9,200 99.9
900 9,200 99.9
Processes
800
800
10,000 99.9
10,000 99.9
Cost
EDC
(per Mg)
$1,028
1,348
$1,333
1,589
<0a
Ef f ectlveness
Total VOC
(per Mg)
$324
425
$240
286
(C) = (A)
H
I
-------
Installed Capital Cost ($1000) (December 1979)
M
I
M
3
K- H
01 3
VI 01
H- rt
O PJ
O fl>
0 Cb
rt n
rt
tr 91
><; M
>-3 n
y o
(D <
o ti
X M
H- CD
Cb 3
&) rt
rt
H- O
0 QJ
3 n3
CJ
n
Ml
O
&. o tr
rt> (n ft> n>
Hi H M h
3333
p) QJ PJ (H
H-
0 O 0 0
X X X X
H- H- H
Cb Cb Oi Cb
Q) £D PJ DJ
rt rt rt rt
H- H- H- H-
0000
3333
s: s s: s:
H- H- H- I-1'
rt rt rt rt
y y y y
O 0
3- d 3J C
(D rt
PJ
rt 3'
n>
H PJ
n>
0)
PJ - .
rt (D rt
(D
O n
0 M 0
< fl> <
(D O CD O
HOMO
•< fC •• ID
o ><: PJ k<
x - H- -
•< M
i£l O PJ
ro x W H-
ro o
n
CD
o
o
(D
01
01
(D H
0) 0
01 O
(D
cn
01
CD
rt
O
p)
n
h1-
rt
O
<
H
-------
VI-8
in the flue gases valued as equivalent to natural gas at $1.90/GJ and not for
the steam that may be generated. The net annual cost for each case was then
calculated (see Table VI-3) and plotted in Fig. VI-2 to show the variation with
plant capacity for both cases. The cost effectiveness for each case for control-
ling both ethylene dichloride and total VOC was calculated from the net annual
cost and the emission reduction (see Table VI-3).
b. Storage Sources -- The control system for storage sources is the use of refrig-
erated vent condensers. Another EPA report covers storage and handling emis-
sions and their applicable controls for all the synthetic organic chemicals
4
manufacturing industry.
c. Fugitive Sources -- A control system for fugitive sources is defined in Appendix C.
Another EPA report will cover fugitive emissions and their applicable controls
for all the synthetic organic chemicals manufacturing industry.
d- Secondary Sources -- No control system has been identified for controlling the
secondary emissions from wastewater treatment. The secondary emissions from
the incinerator can be controlled by changing operating conditions. Another
EPA report covers secondary emissions and their applicable controls for all
the synthetic organic chemicals manufacturing industry.
2. Direct-Chlorination and Oxychlorination (Oxygen) Processes
a- Process Vents -- The estimated installed capital cost of a thermal oxidizer de-
signed to reduce by 99.9% the ethylene dichloride and total VOC from the process
vents in the oxygen-process model plant is $1.75 million with heat recovery and
$1.4 without heat recovery (see Table VI-3). These costs are based on a thermal
oxidizer designed for a residence time of 0.75 sec at 1200°C, completely instal-
led, and includes a quench chamber, tail gas scrubber, sump, pumps, blower, and
stack.
Figure VI-1 shows the variation of installed capital cost of a thermal oxidizer,
with and without heat recovery, versus plant capacity.
-------
VI-9
6000
-------
VI-10
The cost effectiveness was calculated as described above for the air-process
thermal oxidizer (see Table VI-3). The net annual costs for oxygen-process ther-
mal oxidizers with and without heat recovery are given in Table VI-3 and the
variations with plant capacity are shown in Fig. VI-2.
-------
VI-11
C. REFERENCES*
1. W. A. Schwartz et al., Houdry Div., Air Products and Chemicals, Engineering and
Cost Study of Air Pollution Control for the Petrochemical Industry. Volume 3.-
Ethylene Dichloride Manufacture by Oxychlorination, EPA-450/3-73-006-C, Research
Triangle Park, NC (November 1974).
2. P. Reich, "Air or Oxygen for VCM?" Hydrocarbon Processing S5(3), S5--89 (1976).
3. C. G. Bertram, "Minimizing Emissions from Vinyl Chloride Plants," Environmental
Science and Technology 11(9), 864—868 (1977).
4. D. G. Erikson, IT Enviroscience, Inc., Storage and Handling (in preparation
for EPA, ESED, Research Triangle Park, NC).
5. D. G. Erikson, IT Enviroscience, Inc., Fugitive Emissions (in preparation for
EPA, ESED, Research Triangle Park, NC).
6. J. J. Cudahy and R. L. Standifer, IT Enviroscience, Inc., Secondary Emissions
(June 1980) (EPA/ESED report, Research Triangle Park, NC).
^Usually, when a reference is located at the end of a paragraph, it refers to
the entire paragraph. If another reference relates to certain portions of
that paragraph, that reference number is indicated on the material involved.
When the reference appears on a heading, it refers to all the text covered by
that heading.
-------
VII-1
VII. SUMMARY
Ethylene dichloride (EDC) is produced by the direct chlorination of ethylene
and by the oxychlorination of ethylene with hydrogen chloride (HCl) and oxygen
or air, often in a balanced plant, where the EDC is used to make vinyl chloride
monomer (VCM) and with hydrogen chloride (HCl) produced as by-product. The HCl
is recycled and the ethylene dichloride product is about evenly split between
the direct-chlorination step and the oxychlorination step.1""3
The annual growth rate of ethylene dichloride production is estimated to be 4
to 5%, and production is projected to utilize 85 to 89% of 1977 capacity by
1982.
Emission sources and uncontrolled and controlled emission rates from model plants
for the direct-chlorination and the oxychlorination (air and oxygen) processes
are given in Table VII-1. The emissions projected for the domestic ethylene
dichloride industry based on the estimated control of about 70% in 1978 are
11,000 Mg of ethylene dichloride per year and 34,000 Mg of total VOC per year.
Control devices for operating plants include thermal oxidizers, catalytic oxi-
dizers, vent condensers, scrubbers, and vent-gas post reactors. An emission
reduction of 99.9% may be realized in a thermal oxidizer. The installed capital
cost of a thermal oxidizer for the air-based-process model plant is $2.7 million
with heat recovery and $2.1 without heat recovery,- for the oxygen-based-process
model plant it is $1.75 million with heat recovery and $1.4 million without heat
recovery. Supplemental fuel is required for the combustion of the gases from
the direct-chlorination, oxychlorination (air), and column vents but not for
the oxygen-process vents because those gases contain much less nitrogen and are
self-combustible.
For the thermal oxidizer on the direct-chlorination and oxychlorination (air)
model-plant vents the cost effectiveness for control of ethylene dichloride is
J. L. Blackford, "Ethylene Dichloride," pp. 651.5031A--651.50331 in Chemical
Economics Handbook, Stanford Research Institute, Menlo Park, CA (November 1975).
2
P. Reich, "Air or Oxygen for VCM?" Hydrocarbon Processing 55(3), 85—89 (1976).
W. E. Wimer and R. E. Feathers, "Oxygen Gives Low Cost VCM~ Hydrocarbon
Processing 55(3), 81--84 (1976).
-------
VII-2
Table VII-1. Emission Summary for Model Plants
Emission Rate (kg/hr)
Vent or Sourc
Designatior
Emission Source (Figs. III-l,
Oxychlorination vent
For air process
For oxygen process
Direct-chlorination vent
Column vents
Storage vents
In-process
Product
Liquid waste
Tar
Fugitive
Secondary
Wastewater treatment
Incinerator
Total for air process
Total for oxygen process
A
Aa
B
C
D
E
F
G
H
I
J
if}
Uncontrolled
i
2) EDC
148
21.1
49.1
137
0.679
3.34
12.1
0.829
350
220
Total VOC
327
429
130
594
0.679
3.34
1.35
0.0373
24.3
1.24
8.68
1100
1200
Controlled
EDC
0.148
0.0211
0.0491
0.137
0.102
0.502
3.39
0.829
5.2
5.0
Total V0<
0.327
0.429
0.130
0.594
0.102
0.502
0.240
0.0373
6.79
1.24
10
10
a
See Fig. III-2 for this source; see Fig. III-l for all other sources.
-------
VII-3
$1028/Mg if heat is recovered and $1348/Mg if it is not. The cost effective-
ness for control of total VOC is $324/Mg with heat recovery and $425/Mg without
heat recovery. The cost effectiveness of the thermal oxidizer on the direct-
chlorination and oxychlorination (oxygen) model-plant vents is $1333/Mg of ethy-
lene dichloride and $240/Mg of total VOC if heat is recovered or $1589/Mg of
ethylene dichloride and $286/Mg of total VOC without heat recovery. Approximately
37 GJ of steam per hour is produced from the air-process thermal oxidizer flue
gases at approximately 70% recovery and about 27 GJ/hr from the oxygen-process
gases at the same recovery.
-------
A-l
APPENDIX A
PHYSICAL PROPERTIES OP EDC AND ETHYLENE
Table A-l. Physical Properties of 1,2-Dichloroethane*
Synonyms Ethylene dichloride,
ethylene chloride
Molecular formula c H Cl
^ ~x £.
Molecular weight 99.0
Vapor pressure 84.42 mm Hg at 25°C
Melting point -35.5°C
Boiling point 83.5°C at 760 mm Hg
Density 1.257 at 20°C/4°C
Physical state Liquid
Vapor density 3.35
Water solubility 0.43 g/100 ml
*From: J. Dorigan et al., "Ethylene Dichloride,"
p. AII-270 in Appendix II, Rev 1, Scoring_of Organic Air
Pollutants. Chemistry, Production and Toxicity of
Selected JDrganic Chemicals (Chemicals D—E), MTR-7248,
MITRE Corp. (September 1976).
-------
A-2
Table A-2. Physical Properties of Ethylene
Synonyms Acetene, ethene
Molecular formula C2H4
Molecular weight 28.06
Vapor pressure 34,200 mm Hg at 0°C
Melting point -169°C
Boiling point -103.9°C at 760 mm Hg
Density °-99267 at 20°C/4°C
Physical state Gas
Vapor density °-98
Water solubility Insoluble
aFrom J. Dorigan et al., "Ethylene," p. AII-260 in Appendix II,
Rev. 1, Scoring of Organic Air Pollutants. Chemistry, Production
and Toxicity of Selected Organic Chemicals (Chemicals D—E),
MTR-7248, Mitre Corp. (September 1976).
-------
Table B-l.
APPENDIX B
AIR-DISPERSION PARAMETERS
Air-Dispersion Parameters for Ethylene Dichloride Model Plants (Air)
(Capacity, 400,000 Mg/yr), Controlled and Uncontrolled
Source
Oxychlorination vent
Direct-chlorination vent
Column vents
Storage vents
In -process
Product
Liquid waste
Tar
Fugitive
Secondary
Wastewater treatment
Incinerator
Thermal oxidizer with
heat recovery
Thermal oxidizer without
heat recovery
Storage vents
In-process
Product
Liquid waste
Fugitive
Secondary
Incinerator
Emission Rate
(q/sec) Tank Tank Stack
Height Diameter Height
EDC Total VOC (m) (m) (m)
Uncontrolled Emissions
41.1 90.9 50
13.6 36.1 30
38.1 165 20
0.19 0.19 9.8 12.2
0.93 0.93 12.2 19.9
0.37 9.8 7.0
0.010 9.8 7.0
3.36 6.75a
0.23b 0.34b
2-41 30
Controlled Emissions
0.0929 0.292 30
0.0929 0.292
30
0.028 0.028 9.8 12.2
0.14 0.14 12.2 19.9
0.067 9.8 7.0
0.943 1.893
N.D.° 30
Stack Discharge Flow
Diameter Temperature Rate
(m) (K) (m3/sec)
0.6 300 4.34
0.1 300 0.0419
0.2 300 0.218
300
300
300
300
0.6 340 1.45
1.0 330 10.4
1.2 350 15.6
300
300
300
0.6 340 1.45
Discharge
Velocity
(m/sec)
15.4
5.34
6.94
5.12
13.2
13.8
5.12
w
Distributed over an area of 100 m by 200 m.
No control specified.
None detectable.
-------
Table B-2. Air-Dispersion Parameters for Ethylene Dichloride Model Plant (Oxyqen)
(Capacity, 400,000 Mg/yr), Controlled and Uncontrolled
Source
Oxychlorination vent
Direct-chlorination vent
Column vents
Storage vents
In— process
Product
Liquid waste
Tar
Fugitive
Secondary
Wastewater treatment
Incinerator
Thermal oxidizer with
heat recovery
Thermal oxidizer without
heat recovery
Storage vents
In- process
Product
Liquid waste
Fugitive
Secondary
Incinerator
Emission Rate
(g/sec) Tank Tank Stack stack
Height Diameter Height Diameter
EDC Total VOC (m) (m) (m) (m)
Uncontrolled Emissions
5.87 119 cn - ,
3U 0.2
13.6 36.1 -,n „ ,
30 0.1
38.1 165 20 0 2
0.19 0.19 9.8 12.2
0.93 0.93 12.2 19.9
0.37 9.8 7.0
0.010b 9.8 7.0
3.36a 6.75a
0.23b 0.34b
2-41 30 0.6
Controlled Emissions
0.0576 0.320 30 0.9
0.0576 0.320 30 1-0
0.028 0.028 9.8 12.2
0-14 0.14 12.2 19.9
0.067 9.8 7.0
0.94a 1.89a
N I") tr\
• 30 0.6
Discharge
Temperature
(K)
300
300
300
300
300
300
300
340
330
350
300
300
300
340
Flow Discharge
Rate Velocity
(m^/sec) (m/sec)
0.272 8.7
0.0419 5.34
0.218 6.94
1-45 5.12
7.36 H.6
11.0 14.0
1-45 5.12
a i i M i i ~ ' ' ~~ — — : — •
w
K)
No control specified.
None detectable.
-------
C-l
APPENDIX C
FUGITIVE-EMISSION FACTORS*
The Environmental Protection Agency recently completed an extensive testing
program that resulted in updated fugitive-emission factors for petroleum re-
fineries. Other preliminary test results suggest that fugitive emissions from
sources in chemical plants are comparable to fugitive emissions from correspond-
ing sources in petroleum refineries. Therefore the emission factors established
for refineries are used in this report to estimate fugitive emissions from
organic chemical manufacture. These factors are presented below.
Source
Uncontrolled
Emission Factor
(kg/hr)
Controlled
Emission Factorc
(ko/hr)
Pump seals ,
Light-liquid service
Heavy-liquid service
Pipeline valves
Gas/vapor service
Light-liquid service
Heavy-liquid service
Safety/relief valves
Gas/vapor service
Light-liquid service
Heavy-liquid service
Compressor seals
Flanges
Drains
0.12
0.02
0.021
0.010
0.0003
0.16
0.006
0.009
0.44
0.00026
0.032
0.03
0.02
0.002
0.003
0.0003
0.061
0.006
0.009
0.11
0.00026
0.019
aBased on monthly inspection of selected equipment; no inspection of
heavy-liquid equipment, flanges, or light-liquid relief valves,-
10,000 ppmv VOC concentration at source defines a leak; and 15 days
allowed for correction of leaks.
3Light liquid means any liquid more volatile than kerosene.
*Radian Corp., Emission Factors and Frequency of Leak Occurrence for Fittings
in Refinery Process Units, EPA 600/2-79-044 (February 1979).
-------
D-l
APPENDIX D
COST ESTIMATE SAMPLE CALCULATIONS
This appendix contains sample calculations showing how costs presented in this
report were estimated.
The accuracy of an estimate is a function of the degree of data available when
the estimate was made. Figure D-l illustrates this relationship. A contingency
allowance as indicated on this chart has been included in the estimated costs to
cover the undefined scope of the project.
Capital costs given in this report are based on a screening study, as indicated
by Fig. D-l, based on general design criteria, block flowsheets, approximate
material balances, and data on general equipment requirements. These costs have
an accuracy range of +30% to -23%, depending on the reliability of the data, and
provide an acceptable basis to determine the most cost-effective alternate within
the limits of accuracy indicated.
A. THERMAL OXIDIZER CONTROLLING EMISSIONS FROM MODEL PLANT USING THE OXYCHLORINATION
WITH AIR PROCESS
This example is based on the estimated emissions of 8900 scfm, with a heat
content of 50 Btu/scf going to a thermal oxidizer operated at 2200°F with 0.75-sec
residence time and equipped with heat recovery. The estimated emissions include
the vent gases from the oxychlorination vent, from the direct-chlorination vent,
and from the distillation vents and have the following compositions:
Component Composition (mole %)
EDC 0.50
Ethylene 0.98
Other chlorinated hydrocarbons 1.19
Ethane 0.07
Carbon monoxide 1.43
Carbon dioxide 2.03
Oxygen 4.90
Nitrogen 88.90
-------
•^FORMATION USED BY ESTIMATOR
ESTIMATE. TYPE
CO«>T
(PRE.UM. EKIQ. ^TUDV)
(pRLLJM. PROC. EUG,.)
(COMPLETE PROCESS
•
•
*
•
1
\\
\
'\\
\\
\
\
\\
\
v\
_£-=>T/MATE.D COST
"WITH AL.LOWAUCE.
MACK. PROB
COST
01234
APPRO*. Covr
(•/• OF TOTAL-
CAP. coeT1)
-fco -4o -20 O 20 4O foO
D
I
NJ
O IO ZO t>O 40
ACTUAL. PROJECT
Co-bT (f!°}
TO /MCLUDE.
Fig. D-l. Precision of Capital Cost Estimates
-------
D-3
Appendix B of Control Device Evaluation. Thermal Oxidizer Supplement (VOC
Containing Halogens and Sulfur) was used to estimate the costs as follows. On
p B-7 are costs for thermal oxidizers with a residence time of 0.75 sec and with
heat recovery operating at 2200°F on off-gas with a heat content of 50 Btu/scf.
Since the costs are given for 5,000 and 20,000 scfm, it is necessary to estimate
the costs for 8900 scfm by interpolation. This was done by plotting the costs
versus the scfm on log- log graph paper and reading the costs for 8900 scfm from
the curve :
Total installed capital cost = $2,700,000
Fixed costs = 780,000/yr
Operating costs = 3,300,000/yr
Gross annual operating cost = 780,000/yr + 3,300,000/yr = $4,080,000/yr
Recovery credit = 1,100,000/yr
Net annual cost = 4,080,000/yr - 1,100,000/yr = $2,980,000/yr
From Table VI-1 of this report:
Emission reduction = 1290 + 430 + 1200 = 2900 Mg of EDC/yr
cost effectiveness . - - W.028/H9 of EDO
B. THERMAL OXIDIZER CONTROLLING EMISSIONS FROM MODEL PLANT USING THE OXYCHLORINATION
WITH OXYGEN PROCESS
This example is based on the estimated emissions of 1026 scfm, with a heat content
of 573 Btu/scf going to a thermal oxidizer operated at 2200°F with a residence
time of 0.75 sec and equipped with heat recovery. The estimated emissions include
the vent gases from the oxychlorination vent, from the direct-chlorination vent,
and from the distillation vents and have the following compositions;
H. S. Basdekis, IT Enviroscience, Inc., Control Device Evaluation. Thermal
Oxidation Supplement (VOC Containing Halogens or Sulfur) (in preparation for
EPA, ESED, Research Triangle Park, NC) .
-------
D-4
Component Composition (mole %)
EDC 2.69
Ethylene 20.84
Other chlorinated hydrocarbons 9.52
Ethane 0.58
Carbon monoxide 8.20
Carbon dioxide 21.18
Oxygen 5.09
Nitrogen 31.90
A heat-and-mass balance calculation using an IT Enviroscienc, Inc., computer
program shows that no auxiliary fuel is required because of the high heat
content. For a temperature of 2200°F, 9770 scfm of combustion air is required,
and the flue gases contain over 9 mole % oxygen. The total flow of vent gases
and combustion air is 1026 scfm + 9770 scfm = 10,796 scfm.
Two thermal oxidizers operating at 2200°F and 0.75 sec will be the same size
and therefore the installed cost will be the same if the flow of flue gas is
the same. If it is assumed that the change in scfm due to combustion is either
the same or else negligible for both thermal oxidizers, then they will have ap-
proximately the same total scfm of entering waste gas, combustion air, and auxil-
iary fuel, if any. Therefore the costs for a thermal oxidizer sized to handle
1026 scfm of waste gas having a heat content of 573 Btu/scf can be determined
by a calculation of the flow of waste gas having a heat content of 100 Btu/scf
that will require the same size of thermal oxidizer.
From Fig. III-2 of the thermal oxidation supplement report waste gas with a
heat content of 100 Btu/scf will require 24 Btu/scf of waste gas for a combustion
temperature of 2200°F. If natural gas with a heat content of 1000 Btu/scf is
used, then 0.024 scf of fuel gas per scf of waste gas is required. From
Table III-2 of the same report 1.4 scf of combustion air is required per scf
of waste gas having a heat content of 100 Btu/scf to give a combustion tempera-
ture of 2200°F. The total flow to the thermal oxidizer of waste gas, combustion
air, and fuel gas is 1 scf + 1.4 scf + 0.024 scg = 2.424 scf.
-------
D-5
10,796 scfm „,.„„
.424 sc = scfm of waste 9as (10° Btu/scf ) .
2.424 scf/scf
Therefore the costs for a thermal oxidizer sized to burn 4500 scfm of a
100-Btu/scf waste gas at 2200°F for 0.75 sec are the same as those for a thermal
oxidizer that will burn 1026 scfm of a 573-Btu/scf waste gas at the same condi-
tions. On p B-8 of Appendix B of the thermal oxidation supplement report1 the
costs are given for 700 and 5,000 scfm; so interpolation as described above is
required to obtain the following:
Total installed capital cost = $1,750,000
Fixed costs = 510,000/yr
Operating costs = 2,450,000/yr
Gross annual operating costs = 510,000 + 2,450,000/yr = $2,960,000/yr
Recovery credit = 560,000/yr
Net annual cost = 2,960, 000/yr - 560,000/yr = $2,400,000/yr
From Table VI-1 of this report:
Emission reduction = 185 + 430 + 1200 = 1,800 Mg of EDC/yr
cost effectiveness . - - «,333/H9 of EBC
-------
E-l
APPENDIX E
LIST OF EPA INFORMATION SOURCES
I. W. M. Reiter, Allied Chemical Corporation, letter to EPA with information on
Baton Rouge North Works, May 16, 1978.
2. J. A. DeBernardi, Conoco Chemicals, letter to EPA with information on VCM plant
in Lake Charles, Louisiana, May 16, 1978.
3. K. D. Konter, B. F. Goodrich Chemical Company, letter to EPA with information on
EDC manufacturing at Calvert City, Kentucky, June 15, 1978.
4. J. A. Mullins, Shell Oil Company, letter to EPA with information on Deer Park,
TX, EDC plant, June 22, 1978.
5. R. E. Van Ingen, Shell Oil Company, letter to EPA with information on Deer Park,
TX, EDC oxychlorination process, Apr. 10, 1975.
6. R. J. Samelson, PPG Industries, Inc., letter to EPA with information on EDC
emissions at Lake Charles, Louisiana, June 2, 1978.
7. F. C. Dehn, PPG Industries, Inc., letter to EPA with information on EDC oxychlori-
nation process, at Lake Charles, Louisiana and at Guayanilla, Puerto Rico,
Apr. 15, 1975.
8. W. R. Taylor, Diamond Shamrock Corporation, letter to EPA with information on
catalytic oxidation of the oxychlorination vent, at Deer Park, Texas, Oct. 3,
1977 (nonconfidential portion only).
9. W. M. Reiter, Allied Chemical Corporation, letters to EPA with information on EDC
oxychlorination process, at Baton Rouge, Louisiana, Apr. 18, 1975, and June 18,
1975.
10. P. B. Cornell, Louisiana Air Control Commission Emission Inventory Questionnaire
for Allied Chemical Corporation North Works, Baton Rouge, LA (nd).
11. R. M. Teets, Sr., EPA Questionnaire for Allied Chemical Corporation, Baton Rouge,
Louisiana, Oct. 18, 1972.
12. J. S. Bellecci, Louisiana Air Control Commission Emission Inventory Questionnaire
for Borden Chemical, Apr. 16, 1975.
13. J. A. DeBernardi, Conoco Chemicals, letters to EPA with information on oxychlori-
nation process, in Lake Charles, Louisiana, Apr. 14, 1975, and Nov. 21, 1974.
14. J. A. DeBernardi, Louisiana Air Control Commission Emission Inventory Questionnaire
for Conoco Chemicals, May 31, 1961.
15. D. 0. Popovac, EPA Questionnaire for Conoco Chemicals Lake Charles, Louisiana,
VCM Plant, Sept. 1, 1972.
16. Texas Air Control Board, A Construction Permit*••to Diamond Shamrock Chemical
Company Authorizing Construction of Vinyl Chloride Plant...at La Porte, Harris
County, Texas, Permit No. C-3855 (Nov. 2, 1976).
-------
E-2
17. W. C. Hutton, Texas Air Control Board Emissions Inventory Questionnaire for
Diamond Shamrock Corporation, Sept. 15, 1972, and Dec. 29, 1972.
18. R. D. Hall, EPA Questionnaires for Diamond Shamrock Corporation, Sept. 15, 1972,
and Dec. 29, 1972.
19. H. W. Johnson, Jr., Texas Air Control Board Emissions Inventory Questionnaires
for Dow Chemical Co., Texas Division, Feb. 6, 1976.
20. M. H. Siemens, Dow Chemical USA, letters to EPA with information on oxychlorina-
tion vent, at Oyster Creek Division, Nov. 14, 1974, and Feb. 25, 1975 (nonconfi-
dential portions only).
21. M. H. Siemens, Texas Air Control Board 1975 Emissions Inventory Questionnaire for
Dow Chemical USA, Oyster Creek Division, Mar. 19, 1976.
22. C. A. Christian, EPA Questionnaire for Dow Chemical USA, Oyster Creek Division,
Aug. 4, 1972.
23. G. W. Daigre, EPA Questionnaire for Dow Chemical USA Louisiana Division, Sept. 8,
1972. '~
24. R. H. Marshall, Texas Air Control Board 1975 Emissions Inventory Questionnaire
for Ethyl Corp., Pasadena, Texas, Mar. 21, 1976.
25. J. H. Huguet, EPA Questionnaires for Ethyl Corporation, Baton Rouge, Louisiana,
Sept. 8, 1972, and Oct. 19, 1972.
26. W. C. Holbrook, B. F. Goodrich Chemical Company, letter to EPA with information
on oxychlorination process at Calvert City, Kentucky, Apr. 7, 1975.
27. C. L. Woods, EPA Questionnaire for B. F. Goodrich Chemical Company Calvert City,
Kentucky, June 26, 1972.
28. A. T. Raetzsch, Louisiana Air Control Commission Emission Inventory Questionnaire
for PPG Industries, Inc., Mar. 3, 1976.
29. W. B. Graybill and C. A. Burns, EPA Questionnaires for PPG Industries, Inc.,
Lake Charles, Louisiana, January 1973 and August 1972.
30. R. E. Van Ingen, Shell Oil Company, letters to EPA with information on oxychlori-
nation and direct chlorination vents at Deer Park, Texas, June 14, 1974, July 5,
1974, and Dec. 6, 1974.
31. R. J. Trautner, Louisiana Air Control Commission Emission Inventory Questionnaire
for Shell Chemical Company-Norco Plant, Jan. 31, 1977.
32. R. Gliuard, Texas Air Control Board 1975 Emissions Inventory Questionnaire for
Shell Chemical Co. Deer Park Manufacturing Complex, Mar. 19, 1976.
33. A. L. de Vries, EPA Questionnaire for Stuaffer Chemical Company Long Beach,
California, Jan. 10, 1973.
-------
E-3
34. B. G. Perry, Louisiana Air Control Commission Emission Inventory Questionnaire
for Union Carbide Corporation Taft Plant, Mar. 6, 1975.
35. R. E. O1Bryan, Texas Air Control Board 1975 Emissions Inventory Questionnaire
for Union Carbide Corporation Texas City Plant, Mar. 19, 1976.
36. D. E. Gilbert, Vulcan Materials Company, letter to EPA with information on oxy-
chlorination process at Geismar, Louisiana, Apr. 23, 1974.
37. G. A. Vlacos, Louisiana Air Control Commission Emission Inventory Questionnaire
for Vulcan Materials Company Geismar, Louisiana Plant, Aug. 16, 1976.
38. W. W. Duke, EPA Questionnaire for Vulcan Materials Company Geismar, Louisiana
Plant, Oct. 12, 1972.
-------
F-l
APPENDIX F
EXISTING PLANT CONSIDERATIONS
A. PROCESS CONTROL DEVICES
Table F-l lists process control devices reported in use by industry. To gather
information for the preparation of this report two site visits were made to
producers of ethylene dichloride. Trip reports have been cleared by the companies
1 2
concerned and are on file at EPA, ESED, Research Triangle Park, NC. ' Other
sources of the information in this appendix are letters in response to requests
by EPA for information on emissions from ethylene dichloride and vinyl chloride
plants; see Appendix E. Some were part of the Houdry studies — or EPA studies
of vinyl chloride emissions and were furnished by EPA for use in this study.
Some information on existing controls were obtained from the nonconfidential
portions of Texas and Louisiana Emission Inventory Questionnaires collected
during this study. These are also listed in Appendix E. When information from
more than one source did not agree, the data from the source with the latest
date was used.
7 14
Table F-2 — gives the reported analyses of the emissions from several oxy-
chlorination vents, and Table F-3 gives the reported analyses from three direct-
chlorination vents. Similar data are in the Houdry reports — and supporting
letters (see Appendix E) and were also used in preparing this report.
B. RETROFITTING CONTROLS
The primary difficulty associated with retrofitting may be in finding space to
fit the control device into the existing plant layout. Because of the costs
associated with this difficulty it may be appreciably more expensive to retrofit
emission control systems in existing plants than to install a control system
during construction of a new plant.
No thermal oxidizers have been retrofitted to air process oxychlorination
vents; however, Borden's recently constructed plant at Geismar has a thermal
oxidizer with heat recovery that is fed the vent gases from their oxychlorina-
tion (air) step and several other vent gas streams. When visited, their unit
had been out of service for modifications to correct design problems and so no
actual operating data are yet available.
-------
Table F-l. Emission Controls Used by the Ethylene Bichloride Industry0
Company and Process
Location Used
Allied
Baton Rouge , LA Air
Borden
Geismar, LA Air
Conoco
Westlake, LA Air
Diamond Shamrock
Deer Park, TX Air
La Porte, TX Air
Dow
Freeport, TX NR
Oxyster Creek, TX Oxygen
B. F. Goodrich
Calvert City, KY Air
Date of
Construction Emission Sources
NR Oxychlorination vent
Stripper ejector
Purification vent
1977 Oxychlorination vent
Direct-chlorination vent
Purification vents
NR Oxychlorination vent
Direct-chlorination vent
Purification vents
NR Oxychlorination vent
Direct-chlorination vent
Purification vents
1978 Process vents
NR Process vents
1968 Process vents
NR Oxychlorination vent
Direct-chlorination vent
VOC Emission
Rate
1390 kg/hr
98 lb/hrc
230 lb/hr°
NR
NR
NR
1085 Ib/hr
69 Ib/hr
NR
260 Ib/hr
NR
NR
NR
NR
NR
1880 Ib/hr
119 Ib/hr
Control Technique
or Device Used
None
None
Return to process
Thermal oxidizer
Thermal oxidizer
Thermal oxidizer
hr
K
Post reactor
Refrigerated condenser
Water scrubber
Catalytic oxidizer
Refrigerated condenser
Vent condensers
Thermal oxidizer
Thermal oxidizer
Thermal oxidizer
Solvent absorption
Refrigerated vent condenser
-------
Table F-l. (Continued)
Company and
Location
Process
Used
Date of
Construction
Emission Sources
VOC Emission
Rate
Control Technique
or Device Used
PPG
Lake Charles, LA
Guayanilla, PR
Shell
Deer Park, TX
Vulcan
Geismar, LA
Oxygen
Oxygen
Air
Air
1969
NR
NR
NR
Oxychlorination vent 570 Ib/hr
Direct-chlorination vent 700 Ib/hr
Process vents NR
Oxychlorination vent 1040 Ib/hr
Direct-chlorination vent*\
Purification vents ) 495 Ib/hr
Storage vents J
Oxychlorination vent 250 Ib/hr
Purification vents 100 Ib/hr
Thermal oxidizer
Thermal oxidizer
Thermal oxidizer
Post reactor
Thermal oxidizer
Chilled water scrubber
None
u>
See Appendix E.
Not reported.
~t
"Design data.
Plans to install a thermal oxidizer.
-------
Table F-2. Reported Uncontrolled Emissions from Oxychlorination Vents
Compositions Reported by
Component
EDC
Ethyl chloride
Ethylene
Other VOC
Ethane
Methane
Carbon dioxide
Carbon monoxide
Nitrogen
Oxygen
Total
Allieda
(wt %)
3.03
0.92
6.53
0.92
0.9
2.13
0.86
79.25 "">
5.44 J
b c
Conoco Diamond Shamrock
(Ib/hr) (Ib/hr)
414 74.4
489
117 183.1
60 2.45
5
42
895
434 243.5
42,227
1,270
18,900
a
B. F. Goodrich
(Ib/hr)
200
318
68
106
647
2,045
481
62,688
5,076
PPG6 Shellf Vulcan9
(wt %} (wt %) (Ib/hr)
0.75 130
1.00 0.59
26 0.02 119
3 0.23 0.75
254
44
4 1.00 119
15
3
See refs 7 and 8.
See ref 9.
See ref 10.
See ref 11.
eSee ref 12.
See ref 13.
gSee ref 14.
"d
-------
F-5
Table F-3. Reported Uncontrolled Emissions from
Direct-Chlorination Vents
Component
EDC
Ethyl chloride
Ethylene
Other VOC
Ethane
Methane
Carbon dioxide
Carbon monoxide
Nitrogen
Oxygen
Hydrogen
Conoco
(mole %)
1.7
0.01
3.3
0.02
0.8
15.1
1.63
1.1
42.8 1
14.5 '
4.4
Compositions Reported by
PPGb Shell0
(wt %) (wt %)
5 4.6
5 2.1
44 0.8
2.6
2
19
1.2
17
asee ref 9.
See ref 12.
'includes vents on reactor, wash system, purification, storage, and
steam stripper; see ref 13.
-------
F-6
Diamond Shamrock has retrofitted a commercial-sized catalytic oxidizer to their
older oxychlorination facility. The unit reportedly does remove carbon monoxide
and ethylene with better than 99.7% reduction,- however, it removes less than
75% of the ethylene dichloride and less than 60% of the VCM, with 100 ppm of
ethylene dichloride and 8 ppm of VCM remaining in the stack gases.10
Because some companies may have excess steam capacity on-site, it may not be
economically feasible to retrofit a thermal oxidizer with heat recovery. Both
PPG and Dow have indicated plans to incorporate heat recovery in their thermal
oxidizers.15'16
-------
F-7
C. REFERENCES*
1. J. A. Key, IT Enviroscience, Inc., Trip Report for Visit to Borden Chemical,
Geismar, LA, Mar. 2, 1978 (on file at EPA, ESED, Research Triangle Park, NC).
2. J. A. Key, IT Enviroscience, Inc., Trip Report for Visit to Dow Chemical, U.S.A.,
Oyster Creek Division, Freeport, TX, Sept. 20, 1977 (on file at EPA, ESED,
Research Triangle Park, NC).
3. R. G. Bellamy and W. A. Schwartz, Houdry Div., Air Products and Chemicals,
Engineering and Cost Study of Air Pollution Control for the Petrochemical
Industry. Volume 8: Vinyl Chloride Manufacture by the Balanced Process,
EPA-450/3-73-006-h, Research Triangle Park, NC (July 1975).
4. W. A. Schwartz et al., Houdry Div., Air Products and Chemicals, Engineering and
Cost Study of Air Pollution Control for the Petrochemical Industry. Volume 3:
Ethylene Dichloride Manufacture by Oxychlorination, EPA-450/3-73-006-C, Research
Triangle Park, NC (April 1974).
5. J. W. Pervier et al., Houdry Div., Air Products and Chemicals, Survey Reports on
Atmospheric Emissions from the Petrochemical Industry, vol II, EPA-450/3-73-005-b,
Research Triangle Park, NC (April 1974).
6. Standard Support and Environmental Impact Statement: Emission Standard for
Vinyl Chloride, EPA-450/2-75-009, Research Triangle Park, NC (October 1975).
7. W. M. Reiter, Allied Chemical Corporation, letter to EPA with information on
Baton Rouge North Works, May 16, 1978.
8. Personal communication between B. A. Boeneke, Allied Chemical Corporation,
Baton Rouge, LA, and D. C. Mascone, EPA, Aug. 21, 1978.
9. J. A. DeBernardi, Conoco Chemicals, letter to EPA with information on VCM
plant in Lake Charles, LA, May 16, 1978.
10. W. R. Taylor, Diamond Shamrock Corporation, letter to EPA with information
on catalytic oxidation of the oxychlorination vent at Deer Park, TX, Oct. 3,
1977 (nonconfidential portion only).
11. W. C. Holbrook, B. F. Goodrich Chemical Company, letter to EPA with information
on oxychlorination process at Calvert City, KY, Apr. 7, 1975.
12. R. J. Samelson, PPG Industries, Inc., letter to EPA with information on EDC
emissions at Lake Charles, LA, June 2, 1978.
13. J. A. Mullins, Shell Oil Company, letter to EPA with information on Deer Park,
TX, EDC plant, June 22, 1978.
14. C. V. Gordon, Vulcan Materials Company, letter to EPA with information on
EDC plant at Geismar, LA, Oct. 24, 1978.
-------
F-8
15. M. H. Siemens, Dow Chemical USA, letters to EPA with information on oxychlorina-
tion vent at Oyster Creek Division, Nov. 14, 1974, and Feb. 25, 1975 (nonconfi-
dential portions only).
16. F. C. Dehn, PPG Industries, Inc., letter to EPA with information on EDC
oxychlorination process at Lake Charles, LA, and at Guayanilla, PR, Apr. 15,
1975.
*Usually, when a reference is located at the end of a paragraph, it refers to
the entire paragraph. If another reference relates to certain portions of
that paragraph, that reference number is indicated on the material involved.
When the reference appears on a heading, it refers to all the text covered by
that heading.
-------
2-i
REPORT 2
CARBON TETRACHLORIDE AND PERCHLOROETHYLENE BY THE
HYDROCARBON CHLORINOLYSIS PROCESS
(ABBREVIATED REPORT)
F. D. Hobbs
C. W. Stuewe
IT Enviroscience
9041 Executive Park Drive
Knoxville, Tennessee 37923
Prepared for
Emission Standards and Engineering Division
Office of Air Quality Planning and Standards
ENVIRONMENTAL PROTECTION AGENCY
Research Triangle Park, North Carolina
September 1980
This report contains certain information which has been extracted from the
Chemical Economics Handbook, Stanford Research Institute. Wherever used, it
has been so noted. The proprietary data rights which reside with Stanford
Research Institute must be recognized with any use of this material.
D23A
-------
2-iii
CONTENTS OF REPORT 2
I. ABBREVIATIONS AND CONVERSION FACTORS !_!
II. INDUSTRY DESCRIPTION U-l
A. Introduction II-l
B. Carbon Tetrachloride II-l
C. Perchloroethylene II-3
D. References II-9
III. PROCESS DESCRIPTION III-l
A. Introduction III-l
B. Hydrocarbon Chlorinolysis Process III-l
C. Process Variations III-4
D. References III-6
IV. EMISSIONS IV-i
A. Introduction IV-1
B. Sources and Emissions IV-1
C. References IV-8
V. APPLICABLE CONTROL SYSTEMS V-l
A. Process Emissions V-l
B. Storage Emissions V-l
C. Handling Emissions V-l
D. Fugitive Emissions V-l
E. Secondary Sources V-3
F. References V-4
APPENDICES OF REPORT 2
A. PHYSICAL PROPERTIES OF CARBON TETRACHLORIDE AND PERCHLOROETHYLENE A-l
B. FUGITIVE-EMISSION FACTORS B-l
C. LIST OF EPA INFORMATION SOURCES C-l
D. EXISTING PLANT CONSIDERATIONS D-l
-------
2-v
TABLES OF REPORT 2
Number Page
II-l Carbon Tetrachloride Usage II-2
II-2 Carbon Tetrachloride Capacity II-4
II-3 Perchloroethylene Usage and Growth II-7
II-4 Perchloroethylene Capacity II-7
IV-1 Uncontrolled Emissions IV-2
IV-2 Model-Plant Storage Tank Data IV-4
V-l Controlled Emissions V-2
A-l Physical Properties A~l
FIGURES OF REPORT 2
II-l Locations of Plants Manufacturing Carbon Tetrachloride II-5
II-2 Locations of Plants Manufacturing Perchloroethylene II-8
III-l Process Flow Diagram for Mixed Hydrocarbon Clorinolysis III-2
-------
1-1
ABBREVIATIONS AND CONVERSION FACTORS
EPA policy is to express all measurements used in agency documents in metric
units. Listed below are the International System of Units (SI) abbreviations
and conversion factors for this report.
To Convert From
Pascal (Pa)
Joule (J)
Degree Celsius (°C)
Meter (m)
Cubic meter (m3)
Cubic meter (m3)
Cubic meter (m3)
Cubic meter/second
(ms/s)
Watt (W)
Meter (m)
Pascal (Pa)
Kilogram (kg)
Joule (J)
To
Atmosphere (760 mm Hg)
British thermal unit (Btu)
Degree Fahrenheit (°F)
Feet (ft)
Cubic feet (ft3)
Barrel (oil) (bbl)
Gallon (U.S. liquid) (gal)
Gallon (U.S. liquid)/min
(gpm)
Horsepower (electric) (hp)
Inch (in.)
Pound-force/inch2 (psi)
Pound-mass (Ib)
Watt-hour (Wh)
Standard Conditions
68°F = 20°C "
1 atmosphere = 101,325 Pascals
PREFIXES
Multiply By
9.870 X 10"6
9.480 X 10"4
(°C X 9/5) + 32
3.28
3.531 X IO1
6.290
2.643 X 102
1.585 X 104
1.340 X 10"3
3.937 X 101
1.450 X 10"4
2.205
2.778 X 10"4
Prefix
T
G
M
k
m
M
Symbol
tera
giga
mega
kilo
milli
micro
Multiplication
Factor
1012
109
106
103
io"3
io"6
Example
1 Tg = 1 X IO12 grams
1 Gg = 1 X IO9 grams
1 Mg = 1 X IO6 grams
1 km = 1 X IO3 meters
1 mV = 1 X IO"3 volt
1 |jg = 1 X IO"6 gram
-------
II-l
II. INDUSTRY DESCRIPTION
A. INTRODUCTION
There are several processes by which chloromethanes are produced either as co-
products or individually. One process also results in the production of perchloro-
ethylene as a co-product. A previous product report describes the processes of
methanol hydrochlorination to produce methyl chloride and of methyl chloride chlori-
nation to produce methylene chloride, chloroform, and by-product carbon tetrachloride
2
Another product report describes the process of methane chlorination to produce
methyl chloride, methylene chloride, chloroform, and carbon tetrachloride. The
process of carbon disulfide chlorination to produce carbon tetrachloride will not
be reported in detail because of the decline in carbon tetrachloride usage and
the subsequent decline in the importance of the carbon disulfide chlorination
process. The process of hydrocarbon chlorinolysis to produce carbon tetrachloride
and perchloroethylene as co-products is described in this report.
B. CARBON TETRACHLORIDE
1. General Description
Carbon tetrachloride is a heavy, volatile liquid at ambient conditions (see
Appendix A for pertinent physical properties). It is produced by chlorinolysis
of mixed hydrocarbons, methane chlorination, or carbon disulfide chlorination.
Emissions of VOC (volatile organic compounds) resulting from carbon tetrachloride
manufacture include carbon tetrachloride and perchloroethylene from the chlorinolysis
of mixed hydrocarbons process, all the chloromethanes from the methane chlorination
process, and carbon tetrachloride and carbon disulfide from the carbon disulfide
1 2
chlorination process. '
2. Usage and Growth
Table II-l (ref. 3) gives the end uses of carbon tetrachloride. About 90% of
carbon tetrachloride consumption in recent years has been as an intermediate in
the production of trichlorofluoromethane and dichlorodifluoromethane. These two
compounds have been the subject of much controversy concerning their potential
contribution to the depletion of stratospheric ozone. The result has been a 27%
drop in consumption of carbon tetrachloride between 1974 and 1976. (The EPA
promulgated regulations controlling fully halogenated chlorofluoroalkanes on
-------
II-2
a,b
Table II-l. Carbon Tetrachloride Usage
1977 Production
End Use (%)
Trichlorofluoromethane 33.8
Dichlorodifluoromethane 55.0
Miscellaneous 11.2
See ref 3.
Data on growth rates not available.
-------
II-3
March 17, 1978. ) The current domestic carbon tetrachloride production capacity
4
is about 555,000 Mg/yr, with 1979 production utilizing only about 57% of that
capacity. Production is expected to decline by as much as 10% annually. There
are no known plans to increase carbon tetrachloride capacity.
3. Domestic Producers
In 1979 six domestic producers of carbon tetrachloride were operating eleven plants.
Table II-2 lists the producers, locations, capacities, and manufacturing processes •
Fig. II-l shows the plant locations. Dow at Freeport, TX, Pittsburg, CA, and
Plaquemine, LA; Stauffer at Louisville, KY; and Vulcan at Geismar, LA, and Wichita,
KS, all operate plants based on chlorinolysis (see Sect. III-A) of mixed hydro-
carbon feed streams and produce perchloroethylene as a co-product. Allied; Dow
at Freeport, TX, and Pittsburg, CA; FMC; Stauffer at Louisville, KY; and Vulcan
4
at Wichita, KS, are reported to operate plants using the methane chlorination
process, which produces carbon tetrachloride as one of the co-products. Some of
these producers may be using methane feed in the chlorinolysis process. Stauffer
at LeMoyne, AL, and Niagara Falls, NY, operates carbon tetrachloride production
plants that use the carbon disulfide chlorination process. FMC operated a carbon
disulfide chlorination process at South Charleston, WV, which was shut down in
1979. No information on capacity or raw material is available on the Inland
Chemical Corporation plant at Manati, PR. Capacities for all plants other than
those using the carbon disulfide chlorination process are flexible since reaction
conditions can be adjusted to vary the yields of carbon tetrachloride and its
co-products.
C. PERCHLOROETHYLENE
1. General Description
Perchloroethylene is a heavy liquid with moderate volatility at ambient conditions
(see Appendix A for pertinent physical properties). It is produced by chlorination
of ethylene dichloride or acetylene and by the chlorinolysis process, which pro-
duces carbon tetrachloride as a co-product. Emissions from its production include
perchloroethylene and co-products, as well as feed materials, depending on the
manufacturing process.
-------
II-4
Table II-2. Carbon Tetrachloride Capacity
Plant^
Allied, Moundsville, WV
Dow, Freeport, TX
Dow, Pittsburg, CA
Dow, Plaquemine, LA
Du Pont, Corpus Christi, TX
Inland, Manati, PR
Stauffer, Le Moyne, AL
Stauffer, Louisville, KY
Stauffer, Niagara Falls, NY
Vulcan, Geismar, LA
Vulcan, Wichita, KS
Total
lSee ref 4.
^Production ratios are very
'Not available.
1977
Capacity
(X 103 Mg)
Process
61
36
57
154
c
91
16
68
41
27
555
Methyl chloride chlorination and
methane chlorination
Methane chlorination and chlorin-
olysis of mixed hydrocarbon feed
with perchloroethylene co-product
Methane chlorination and chlorin-
olysis of mixed hydrocarbon feed
with perchloroethylene co-product
Chlorinolysis of mixed hydrocarbon
feed with perchloroethylene co-
product
Carbon disulfide chlorination
Methane chlorination and chlorin-
olysis of mixed hydrocarbon feed
with perchloroethylene co-produc1
Carbon disulfide chlorination
Chlorinolysis of mixed hydrocarbon
feed with perchloroethylene co-
product
Methyl chloride chlorination, me the
chlorination, and Chlorinolysis c
mixed hydrocarbon feed with per-
chloroethylene co-product
flexible, especially when co-products are involved.
-------
II-5
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
Allied Chemical Corp., Moundsville, WV
Dow Chemical Co., Freeport, TX
Dow Chemical Co., Pittsburg, CA
Dow Chemical Co., Plaguemine, LA
Du Pont, Corpus Christi, TX
Inland Chemical Corp., Manti, PR
Stauffer Chemical Co.
Stauffer Chemical Co.
Le Moyne, AL
Louisville, KY
Stauffer Chemical Co., Niagara Falls,
Vulcan Materials Co., Geismar, LA
Vulcan Materials Co., Wichita, KS
NY
Fig. II-l. Locations of Plants Manufacturing Carbon Tetrachloride
-------
11-6
2. Usage and Growth
Usage and growth data for perchloroethylene are given in Table II-3. The predomi-
nant use of perchloroethylene is in the textile industry for dry cleaning, process-
ing, and finishing. It is used as a dry-cleaning fluid because of its high density
low water solubility, and good solvent properties. It is also used as a metal
cleaning solvent and as a chemical intermediate; in both cases the growth rate is
predicted to be high. Perchloroethylene has been substituted for trichloroethylene
in many operations because of regulations restricting the use of trichloroethylene.
Q
The current domestic production capacity is 575,000 Mg/yr, with 1979 production
utilizing about 56% of that capacity. Production is expected to increase by about
5.5% annually. There are no known immediate plans to expand perchloroethylene
production capacity.
3. Domestic Producers
In 1977 eight domestic producers of perchloroethylene were operating eleven plants.
Table II-4 (refs. 7 and 9) lists the producers, locations, capacities, and proc-
esses used; Fig. II-2 shows the plant locations. Three of the producers are re-
7 9
ported ' to operate six plants that use the mixed hydrocarbon chlorinolysis
process to produce perchloroethylene with carbon tetrachloride as a co-product
(the only process pertinent to this report). The seven plants are operated by
Dow at Freeport, TX, Pittsburg, CA, and Plaquemine, LA; Stauffer at Louisville,
KY; and Vulcan at Geismar, LA, and Wichita, KS.
-------
II-7
Table II-3. Perchloroethylene Usage and Growth*
1974
Production
End Use (%)
Textile industry (dry cleaning,
processing, finishing)
Metal cleaning solvent
Chemical intermediate
Miscellaneous
69
16
12
3
Average Annual
Growth (%) for
1974 — 1979
4
11
7
2
*See ref 7.
Table II-4. Perchloroethylene Capacity
Plant
Diamond Shamrock, Deer Park, TX
Dow, Freeport, TX
Dow, Pittsburg, CA
Dow, Plaquemine, LA
Du Pont, Corpus Christi, TX
Ethyl, Baton Rouqe, LA
Hooker, Taft, LA
PPG, Lake Charles, LA
Stauffer, Louisville, KY
Vulcan, Geismar, LA
Vulcan, Wichita, KS
Total
1977
Capacity
(X 103 Mg)b
75
54
9
68
73
45
27
109
32
60
23
575
Process
Ethylene dichloride chlorination
Chlorinolysis of mixed hydrocarbons
producing carbon tetrachloride as
a co-product
Same as above
Same as above
Ethylene dichloride chlorination
Acetylene chlorination
Ethylene dichloride chlorination
Chlorinolysis of mixed hydrocarbons
producing carbon tetrachloride as
a co-product
Same as above
Same as above
See refs 7 and 9.
Capacities can vary from the listed amounts
manufactured with the same equipment.
because other chlorinated compounds can be
-------
II-8
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
Diamond Shamrock Corp., Deer Park, TX
Dow Chemical Co., Freeport, TX
Dow Chemical Co. , Pittsburg, CA
Dow Chemical Co., Plaquemine, LA
Du Pont, Corpus Christi, TR.
Ethyl Corp., Baton Rouge, LA
Hooker Chemical Corp., Taft, LA
PPG Industries, Inc., Lake Charles, LA
Stauffer Chemical Co., Louisville, KY
Vulcan Materials Co., Geismar, LA
Vulcan Materials Co. , Wichita, KS
Fig. II-2. Locations
of Plants Manufacturing Perchloroethylene
-------
II-9
D. REFERENCES*
1. F. D. Hobbs and C. W. Stuewe, IT Enviroscience, Inc., Chloromethanes. Methanol
Hydrochlorination and Methyl Chloride Chlorination Processes (in preparation
for EPA, ESED, Research Triangle Park, NC).
2. F. D. Hobbs and C. W. Stuewe, IT Enviroscience, Inc., Chloromethanes. Methane
Chlorination Process (in preparation for EPA, ESED, Research Triangle Park, NC).
3. "(635.2030M) Chlorinated Methanes Salient Statistics," p 235 in Chemical
Economics Handbook, Manual of Current Indicators Supplemental Data, Chemical
Information Services, Stanford Research Institute, Menlo Park, CA (June 1980).
4. E. M. Klapproth, "Carbon Tetrachloride Salient Statistics," pp. 635.2030A-E
in Chemical Economics Handbook, Stanford Research Institute, Menlo Park, CA
(April 1976).
5. Environmental Protection Agency, "Fully Halogenated Chlorofluoroalkanes," Federal
Register, Vol. 43, Part II, p. 11318 (Mar. 17, 1978).
6. "Chemical Profile on Carbon Tetrachloride," p. 9 in Chemical Marketing Reporter
(Oct. 1, 1975).
7. J. L. Blackford, "Perchloroethylene," pp. 685.5031A—685.5033A in Chemical
Economics Handbook, Stanford Research Institute, Menlo Park, CA (November 1975).
8. "(632.3001J) C Chlorinated Solvents," p 228 in Chemical Economics Handbook, Manual
of Current Indicators -Supplemental Data, Chemical Information Services, Stanford
Research Institute, Menlo Park, CA (June 1980).
9. "Chemical Profile on Perchloroethylene," p. 9 in Chemical Marketing Reporter
(Aug. 9, 1976).
^Usually, when a reference is located at the end of a paragraph, it refers to
the entire paragraph. If another reference relates to certain portions of
that paragraph, that reference number is indicated on the material involved.
When the reference appears on a heading, it refers to all the text covered by
that heading.
-------
III-l
III. PROCESS DESCRIPTION
INTRODUCTION
Carbon tetrachloride and perchloroethylene coproducts, along with some chlorinated
hydrocarbon by-products, are manufactured by chlorination of hydrocarbons at or
near pyrolytic conditions in a process commonly referred to as chlorinolysis.
The hydrocarbon feed to this process can be any of several hydrocarbons or a mixture
of hydrocarbons. The reactions using propane or propylene as feed materials are
as follows:
C3H8
(propane)
8C12
(chlorine)
C Cl
LL1
CC1.
8HC1
(perchloro- (carbon (hydrogen
ethylene) tetrachloride) chloride)
C3H6
(propylene)
7C12
(chlorine)
(perchloro-
ethylene)
CC1,
6HC1
(carbon (hydrogen
tetrachloride) chloride)
Also important in the process is the equilibrium established between the coproducts
as represented by the equation
2CC14
(carbon
tetrachloride)
' C2C14 +
(perchloroethylene)
2C12
(chlorine)
As an example of the variety of hydrocarbons that can be used in the process,
crude carbon tetrachloride byproduct from the methanol hydrochlorination and methyl
2
chloride chlorination process, as described in a previous report, can be used as
feed to the reaction.
HYDROCARBON CHLORINOLYSIS PROCESS
The process flow diagram shown in Fig. III-l represents a typical continuous process
for the chlorinolysis of hydrocarbons to produce carbon tetrachloride and perchloro-
ethylene. Preheated hydrocarbon feed material (Stream 1) and chlorine (Stream 2)
enter the chlorinolysis reactor, which is a fluid-bed reactor maintained at about
500°C and contains copper and barium chloride on graphite as a catalyst. The addi-
tion rate of feed materials is used to control the reactor temperature. With proper
-------
CARBON;
REACTOR
Tfl H>.CVA\_c«\c6.
MeTHA.UC*_
®
PERCHUOROE-THYUOJe.
DftTH_LATl04
CAUSTIC
SCRUBBER
wci
e>v - PBODLX:T
wet
Y
COUJMW
Fig. III-l. Process Flow Diagram for Manufacture of Carbon Tetrachloride and Perchloroethylene by
-------
111-3
control of reaction conditions the chlorine and hydrocarbon feed will be almost
completely converted to carbon tetrachloride and perchloroethylene products plus
4
hydrogen chloride and chlorinated hydrocarbon by-products.
The reaction products (Stream 3) pass through a cyclone for removal of entrained
catalyst and then on to a condenser. Uncondensed materials (Stream 4), consisting
of hydrogen chloride, unreacted chlorine, and some carbon tetrachloride, are removed
to the hydrogen chloride purification system. The condensed material (Stream 5)
is fed to a hydrogen chloride and chlorine removal column, with the overheads
(Stream 6) from this column going to hydrogen chloride purification. The bottoms
(Stream 7) from the column are fed to a crude storage tank. Material from crude
storage is fed to a carbon tetrachloride distillation column, with the overheads
(Stream 8) passing either to carbon tetrachloride storage and loading or to the
hydrogen chloride purification system (Stream 9). The bottoms (Stream 10) from
the carbon tetrachloride distillation column are fed to a perchloroethylene distil-
lation column. The overheads (Stream 11) from the perchloroethylene distillation
column are taken to perchloroethylene storage and loading, and the bottoms are
removed for disposal by incineration.
The feed streams (Streams 4 and 6) to hydrogen chloride purification are compressed,
cooled, and scrubbed in a chlorine absorption column with chilled carbon tetra-
chloride (Stream 9) to remove chlorine. The bottoms and condensable overheads
(Stream 12) from this column are combined and recycled to the chlorinolysis reactor.
Uncondensed overheads (Stream 13) from the chlorine absorption column are water-
scrubbed in the hydrogen chloride absorber. Hydrochloric acid solution is removed
from the bottom of this absorber to storage for eventual reprocessing or for use
in a separate facility. Overheads from the absorber and vented gases from by-
product hydrochloric acid storage are combined (Stream 14) and passed through a
caustic scrubber for removal of residual hydrogen chloride. Inert gases are vented
from the scrubber.
Process emission sources originate at the carbon tetrachloride and perchloroethylene
distillation condensers and caustic scrubber (Vents A).
Fugitive emissions throughout the process can contain carbon tetrachloride and
perchloroethylene. Corrosion problems caused by chlorine and hydrogen chloride
can increase fugitive emissions. Storage and handling emissions (labeled B and
C, respectively, on Fig. III-l) include carbon tetrachloride and perchloroethylene.
-------
III-4
Two potential sources of secondary emissions result from handling and incineration
of bottoms from perchloroethylene distillation (labeled K on Fig. III-l) and from
waste caustic from the caustic scrubber (labeled L on Fig. III-l).
C. PROCESS VARIATIONS
There are several possible variations in the process and the manner in which
individual steps within the process are operated as described below. Even a
variant, however, will require the same process steps as those described for the
model process, for example, hydrogen chloride and chlorine removal and recovery
and product purification, storage, and loading. Variations in the manner of
operation are possible without affecting process emissions.
A broad range of hydrocarbon feeds, catalyst systems, and reaction conditions can
be used in the chlorinolysis reactor. Likewise, empty chamber reactors and higher
temperatures can be used for chlorinolysis.
Carbon tetrachloride can be injected into the chlorinolysis reactor to shift the
equilibrium established between carbon tetrachloride and perchloroethylene to
4
increase the production rate of perchloroethylene. This
changes in subsequent storage requirements and emissions.
4
increase the production rate of perchloroethylene. This practice will necessitate
Carbon tetrachloride may be caustic-scrubbed to remove traces of hydrogen chloride
after carbon tetrachloride distillation, which would require a drying operation.
A steam stripper can be used to treat effluent from the caustic scrubbing and
drying operations for removal of carbon tetrachloride, which can be recycled.
Additional storage may be required when liquid hydrocarbons are used as feed to
the chlorinolysis reactor. Such storage will create emissions that will vary in
amounts according to the composition and vapor pressure of the material being
stored and the storage conditions. For example, storage of by-product crude carbon
tetrachloride (the feed material) from a 90,000-Mg/yr methanol hydrochlorination
and methyl chloride chlorination model plant results in calculated emissions of
0.49 kg/hr. This emission source was included in the methanol hydrochlorination
2
and methyl chloride chlorination process described in another product report.
-------
III-5
One producer reported several specific process variations which are as follows:
1. Thermal chlorination is used instead of the fluid bed catalytic process.
2. A quench tower following the thermal reactor removes heavy ends from the
process. Heavy ends from the perchloroethylene distillation are recycled to
the quench tower.
3. A light-ends stripper follows the quench tower. The light ends are recycled
to the reactor.
4. Most inerts in the process are separated in the hydrogen chloride absorption
and chlorine removal system.
5. Solid-phase neutralizer and dessicant traps are used.
6. The caustic scrubber is used only during startups and emergencies.
-------
III-6
D. REFERENCES*
1. D. W. F. Hardie, "Chlorocarbons and Chlorohydrocarbons," p. 132 in Kirk-Othmer
Encyclopedia of Chemical Technology, vol. 5, 2d ed., Interscience, New York, 1964.
2. F. D. Hobbs and C. W. Stuewe, IT Enviroscience, Inc., Chloromethanes.
Methanol Hydrochlorination and Methyl Chloride Chlorination Process (in preperation
for EPA, ESED, Research Triangle Park, NC).
3. F. D. Hobbs, IT Enviroscience, Inc., Trip Report on Visit to Vulcan Materials
Co., Geismar, LA, Jan. 4, 1978 (on file at EPA, ESED, Research Triangle Park,
NC).
4. L. M. Elkin, Chlorinated Solvents, Report No. 48, A Private report by the Process
Economics Program, Stanford Research Institute, Menlo Park, CA (ND).
5. List of EPA Data Sources (on file at EPA, ESED, Research Triangle Park, NC) (see
Appendix C).
6. Thomas A Robinson, Vulcan Materials Company, Wichita, KS, letter dated July 9,
1979, to David R. Patrick, EPA.
^Usually, when a reference is located at the end of a paragraph, it refers to
the entire paragraph. If another reference relates to certain portions of
that paragraph, that reference number is indicated on the material involved.
When the reference appears on a heading, it refers to all the text covered by
that heading.
-------
IV-1
IV. EMISSIONS
Emissions in this report are usually identified in terms of volatile organic
compounds (VOC). VOC are currently considered by the EPA to be those of a large
group of organic chemicals, most of which, when emitted to the atmosphere, parti-
cipate in photochemical reactions producing ozone. A relatively small number of
organic chemicals have low or negligible photochemical reactivity. However, many
of these organic chemicals are of concern and may be subject to regulation by EPA
under Section 111 or 112 of the Clean Air Act since there are associated health
or welfare impacts other than those related to ozone formation.
A. INTRODUCTION
An 80,000-Mg/yr model plant, based on 8760 hr of operation,* was selected to repre-
sent today's hydrocarbon chlorinolysis industry; individual product capacities
were selected to be 50,000-Mg/yr perchloroethylene and 30,000-Mg/yr carbon tetra-
chloride. The individual product capacities were selected on the basis of per-
chloroethylene 's expected growth in usage and the declines in demand for carbon
tetrachloride. The total capacity was based on an approximate mid-range of today's
domestic industry. The model process shown in Fig. III-l is typical of many plants
and best fits today's manufacturing and engineering technology. Single-process
trains as shown are typical.
Typical intermediate- and product-storage requirements were estimated for a
50,000-Mg/yr perchloroethylene and a 30,000-Mg/yr carbon tetrachloride plant.
Storage tanks for feed materials were not included in the plant design, although
producers using liquid waste hydrocarbons, such as the crude carbon tetrachloride
by-product described in an earlier report, would require such storage facilities.
B. SOURCES AND EMISSIONS
Emission rates and ratios and sources for the hydrocarbon chlorinolysis process
are summarized in Table IV-1.
*Process downtime is normally expected to range from 5 to 15%. If the hourly
rate remains constant, the annual production and annual VOC emissions will be
correspondingly reduced. Control devices will ususally operate on the same
cycle as the process. From the standpoint of cost-effectiveness calculations
the error introduced by assuming continuous operation is negligible.
-------
Table IV-1. Uncontrolled Emissions from 80,000-Mg/Yr Chlorinolysis Process Plant
Emission Source
Process vents
Storage
Handling
Fugitive
Hex waste handling and
disposal and waste
hydrocarbon storage
Waste caustic
Total
Uncontrolled Emissions
Ratio (kg/Mg)b Rate (kg/hr)
S Lream
Designation Ethylene
(Fig.III-1) Dichloride
A
B
C
J
K 0.026
L
0.026
Vinylidene Total Ethylene
Chloride0 VOCd Dichloride
0.0053
0.52
0.13
1.48
0.013 0.056 0.24
0.15
0.013 2.34 0.24
Vinylidene Total
Chloride0 VOC
0.049
4.77
1.2
13.51
0.12 0.51
1.4
0.12 21.4
H
f
M
Emissions from plants employing no controls other than those necessary for economical operation.
kg of emission per Mg of product.
CEthylene dichloride and vinylidene chloride are considered by the EPA to be hazardous substances and are reported
separately.
^Composition of emissions will vary according to the feeds to the process.
GThis source of emissions includes handling and incineration of the hex waste and the emissions from waste hydrocar-
bons storage tanks as reported by one producer (see ref. 2). This source is described in detail in Sect. IV-B-4.
-------
IV-3
1. Process Emissions
Inert gases enter the process with the chlorine and hydrocarbons fed to the chlori-
nolysis reactor. Vents for the purging of these inert gases from the process are
associated with the carbon tetrachloride and perchloroethylene distillation con-
densers and the caustic scrubber following hydrochloric acid recovery (Vents A,
Fig. III-l). Limited information is available concerning the individual vents.
2
One producer reported no emissions from the carbon tetrachloride condenser vent
and very limited emissions from the perchloroethylene condenser vent for a cal-
culated total emission ratio from these two sources of less than 1 X 10 kg of
VOC per Mg of total capacity. No emissions were reported for the vent associated
with the caustic scrubber. Another producer reported total process emissions
from distillation vents that were calculated to be about 5.3 X 10 kg of VOC per
Mg of reported capacity (the amount listed in Table IV-1). Information from other
producers indicated no existing process emissions.
2. Storage and Handling Emissions
Storage and handling emission sources for a typical hydrocarbon chlorinolysis
plant are shown on the flow diagram in Fig. III-l (sources B and C respectively).
Storage tank conditions for the model plant are given in Table IV-2. The uncon-
trolled storage emissions included in Table IV-1 were calculated, with the emission
4
equations in AP-42, for fixed-roof tanks, half full, and a diurnal temperature
variation of 12°C. However, breathing losses were divided by 4 to account for
recent evidence indicating that the AP-42 breathing loss equation overestimates
emissions. Emissions from storage included in Table IV-1 are 4.77 kg/hr.
Emissions from storage of feed materials were not included in the model plant
because the feed streams (propane and propylene) were assumed to originate from
pipelines or pressurized storage, which would not emit VOC. However, the chlori-
nolysis process can be used as a means of converting waste hydrocarbons from other
processes into marketable products. For example, the by-product carbon tetrachlo-
ride from methanol hydrochlorination and methyl chlorination can be used as a
feed material to the chlorinolysis process. Emissions from the storage of the
<
by-product carbon tetrachloride were reported as part of the methanol hydrochlo-
rination and methyl chloride chlorination processes. One producer operating a
chlorinolysis facility reported emissions from feed storage tanks containing a
mixture of hydrocarbons. This source of emissions was considered to be waste
-------
IV-4
a
Table IV-2. Model-Plant Storage Tank Data
Content
Crude product
Carbon tetrachloride
Carbon tetrachloride
Perchloroethylene
Perchloroethylene
No. of
Tanks
1
2
1
2
1
Tank Size
(m3)
378
76
757
76
1892
Turnovers Bulk Liquid
per Year Temperature (°C)
6°
125
25
205
16
38
35
20
35
20
aDoes not include feed tanks, which would be required for storage of liquid
waste hydrocarbons from other processes.
blncludes all carbon tetrachloride, perchloroethylene, and hex waste
generated by the process.
°Assumed to operate at nearly constant level.
-------
IV-5
hydrocarbons from other processes. A detailed description of this source is
included in the secondary emissions section (IV-B.4) of this report.
Emissions from loading carbon tetrachloride and perchloroethylene product into
tank cars and trucks also were calculated, based on submerged loading into clean
tank cars and trucks, and with the <
eluded in Table IV-1 are 1.2 kg/hr.
4
tank cars and trucks, and with the equations from AP-42. Loading emissions in-
3. Fugitive Emissions
Process pumps, valves, and compressors are potential sources of fugitive emis-
sions. The 80,000-Mg/yr plant is estimated to have 30 pumps (including spares),
800 process valves, 12 relief valves, and 1 compressor. The fugitive emissions
(J on Fig. III-l) listed in Table IV-1 were determined based on the factors shown
in Appendix B.
4. Secondary Emissions
Secondary emissions of VOC can result from the handling and disposal of process
waste liquids. Two sources of secondary emissions are the bottoms from the per-
chloroethylene distillation (Source K, Fig. III-l), which are commonly called hex
wastes, and the waste caustic from the caustic scrubber (Source L, Fig. III-l).
One producer reported composition of the hex wastes, or bottoms, from the per-
chloroethylene distillation to be the following:
Quantity
Component (mole %)
Ethylene dichloride 1.4
p-Trichloroethane 7.2
Perchloroethylene 5.7
1,1,1,2-Tetrachloroethane 7.9
1,1,2,2-Tetrachloroethane 29.1
Pentachloroethane 2.7
Hexachlorobutadiene 27.5
Hexachlorobenzene 14.9
Hexachloroethane 3.6
-------
IV-6
The amount of hex waste generated in the process was calculated from the reported
data to be about 52.0 kg per Mg of plant capacity.
7
Another producer reported the typical hex waste composition to be:
Component Quantity (%)
Perchloroethylene 4
Hexachloroethane 16
Hexachlorobutadiene 25
Hexachlorobenzene 53
Others 2
It was reported that loading the hex waste from the perchloroethylene distillation
column into trucks for removal to incineration resulted in emissions of less than
-4
1 X 10 kg of VOC per Mg of capacity. However, uncontrolled emissions from a
hex-waste loading operation combined with vented emissions from waste hydrocarbon
storage tanks were reported to be 5.6 X 10 kg per Mg of plant capacity. The
composition of this combined source of emissions was reported as follows:
Quantity
Component (mole %)
Vinyl chloride 0.166
Vinylidene chloride 1.306
trans-Dichloroethylene 0.246
cis-Dichloroethylene 0.124
Chloroform 0.037
Ethylene dichloride 2.607
Trichloroethylene 0.058
Carbon tetrachloride 0.112
Propylene dichloride 0.336
p-Trichloroethane 0.239
1,1,1,2-Tetrachloroethane 0.095
1,1,2,2-Tetrachloroethane 0.046
Pentachloroethane 0.009
Nitrogen 94.620
-------
IV-7
-2
The emission ratio of 5.6 X 10 kg per Mg of plant capacity is included in
Table IV-1 for the combined sources of hex-waste handling and waste hydrocarbon
storage emissions, although their amounts and compositions will vary as broadly
as the diverse feed materials entering the chlorinolysis reaction. Many producers
do not have to store liquid wastes for feed to the process, which would eliminate
the storage portion of these emissions.
The common practice of disposal of the hex-wastes by thermal oxidation creates
secondary emissions because of incomplete oxidation. Secondary emissions from
this source were calculated to be less than 1 X 10 kg of VOC per Mg of plant
capacity based on reported information. Emissions from this source were con-
sidered to be included in the hex-waste handling and waste hydrocarbon storage
emissions described above.
Secondary emissions from waste caustic were calculated from data reported by one
producer to be about 1.1 X 10 kg of VOC per Mg of plant capacity. Data from
another producer indicated the total VOC in aqueous waste discharges to be about
2.9 X 10 kg per Mg of plant capacity. It was estimated by this second producer
that all VOC in the aqueous waste discharge would eventually be emitted to the
7
air. With these two sets of data for secondary wastes assumed to be typical for
the industry, an average of the two emissions ratios is about 1.5 X 10 kg of
total VOC per Mg of plant capacity.
Based on the data in Appendix D and on the assumption that the combined produc-
tion of carbon tetrachloride and perchloroethylene by the chlorinolysis process
as calculated from the industry data given in Sect. II was 340,000 Mg/yr in 1979
and that the average industry emissions correspond to the 80,000-Mg/yr plant dis-
cussed in this report, the 1979 industry emissions are projected to be about
727 Mg/yr.
-------
IV-8
C. REFERENCES*
1. F. D. Hobbs and C. W. Stuewe, IT Enviroscience, Inc., Chloromethanes.
Methanol Hydrochlorination and Methyl Chloride Chlorination Process (in
preparation for EPA, ESED, Research Triangle Park, NC).
2. F. D. Hobbs, IT Enviroscience, Inc., Trip Report on Visit Regarding Geismar, LA
Plant of Vulcan Materials Co., Jan. 4, 1978 (on file at EPA, ESED, Research
Triangle Park, NC).
3. D. W. Smith, Du Pont, Wilmington, DL, letter to D. R. Goodwin, EPA, Mar. 23, 1978.
4. C. C. Masser, "Storage of Petroleum Liquids," pp 4.3-1—4.3.12 in Compilation
of Air Pollutant Emission Factors, AP-42, Part A, 3d ed., EPA (August 1977).
5. E. C. Pulaski, TRW, Inc., letter dated May 30, 1979, to Richard Burr, EPA.
6. P. Reis, Texas Air Control Board, Emissions Inventory Questionnaire, TACB Account
Number 104-137-1, Dow Chemical Co., Freeport, TX, data for 1975.
7. J. Beale, Dow Chemical, Midland, MI, letter dated Mar. 1, 1978 to L. Evans, EPA.
8. Thomas A. Robinson, Vulcan Materials Company, Wichita, KS, letter dated July 9,
1979, to David R. Patrick, EPA.
*Usually, when a reference is located at the end of a paragraph, it refers to the
entire paragraph. If another reference relates to certain portions of that para-
graph, that reference number is indicated on the material involved. When the
reference appears on a heading, it refers to all the text covered by that heading.
-------
V-l
V. APPLICABLE CONTROL SYSTEMS
A. PROCESS EMISSIONS
Process emissions as listed in Table IV-1 of this report constitute less than
1% of the total uncontrolled emissions from the hydrocarbon chlorinolysis process.
No controls are identified for process emissions.
B. STORAGE EMISSIONS
Uncontrolled storage of intermediates, in-process materials, and final products
as listed in Table IV-1 of this report constitutes about 50% of total emissions
from the hydrocarbon chlorinolysis process. Refrigerated condensers are used,
in some cases in conjunction with pressurized-nitrogen padding, to reduce emis-
sions from carbon tetrachloride storage tanks by 60 to 80%, depending on the
1 2
design of the control system. ' One such condenser, which was installed in
1975 at a cost of $10,000, reduced emissions by about 10,400 kg/yr with an energy
use of about 300 MJ/day. A pressurized-nitrogen padding system was installed
on a storage tank in 1968 for $800. Use of 1.36 X 10 Pa pressurized-nitrogen
padding on perchloroethylene storage tanks was reported to reduce losses from
?8
I
storage of that material by 35% for a cost of $800 in 1968. With this technique
the emissions were reduced by about 2100 kg/yr."
The controlled storage emissions given in Table V-l were based on 80% control
by use of refrigerated condensers. Storage emissions are discussed in detail
in a separate report.
C. HANDLING EMISSIONS
No method was reported by the producers surveyed for control of emissions from
handling carbon tetrachloride or perchloroethylene product. Handling emissions
are discussed in detail in a separate report.
D. FUGITIVE EMISSIONS
Control for fugitive sources is discussed in a document covering fugitive emissions
4
from the synthetic organic chemicals manufacturing industry (SOCMI). The fugitive
emissions given in Table V-l were calculated with the factors given in Appendix B.
These factors are based on the assumption that any major leaks will be detected
and corrected.
-------
Table V-l. Controlled Emissions3 from 80,000-Mg/yr Chlorinolysis Process Plant
Stream
Designation
Emission Source (Fig. III-l)
Process vents A
Storage B
Handling c
Fugitive J
None
Control Emission
Device or Reduction
Technique (%)
Refrigerated condenser BO
None
Detection and correction
Emissions
Total VOC Ratio
(kg/Mg)b
0
0
0
0
.0053
.10
.13
.46
Total VOC Rate
(kg/hr)
0
0
1
4
.049
.95
.2
.19
of major leaks
Feed storage and K
hex waste handling
and disposal
Waste caustic L
Total
Vapor
balance and %99
<0
.001
<0
.01
refrigerated condenser
Steam
stripper 96
0
0
.006
.70
0
6
.056 f
NJ
.46
aAll emissions are based on 87GO hr of operation per year.
bkg of emissions per Mg of combined carbon tetrachloride and perchloroethylene produced.
CA11 emissions eliminated except those from thermal oxidation of the hex wastes.
-------
V-3
E. SECONDARY SOURCES
Emissions from loading of hex wastes from the perchloroethylene distillation
column into trucks for transport to a thermal oxidizer were reported to have
been eliminated by one producer. A vapor-balance system was installed to partially
control emissions from hex-waste handling in 1975 at a reported cost of $200,000.
Emissions from the hex-waste vapor-balance system were then combined with emis-
sions from storage of waste products that are used as a feed to the reactor and
controlled with a refrigerated condenser, which cost $35,000 in 1974. The material
exiting the refrigerated condenser was then recycled to the chlorinolysis reactor.
The reduction in emissions from use of the two control devices and the eventual
recycle was about 6400 kg/yr. About 450 MJ/day is required to operate the refrig-
erated condenser. The only emissions remaining uncontrolled are those from the
thermal oxidizer, which is used to destroy the hex wastes originating at the
perchloroethylene distillation column.
Installation of a steam stripper was reported to reduce VOC content in the waste
caustic by about 96%. VOC stripped from the waste caustic is recycled to the
process. Controlled secondary emissions from
are based on installation of a steam stripper.
process. Controlled secondary emissions from the waste caustic listed in Table II-l
-------
V-4
F. REFERENCES*
1. J. Beale, Dow Chemical, Midland, MI, letter to L. Evans, EPA, Mar. 1, 1978.
2. F. D. Hobbs, IT Enviroscience, Inc., Trip Report on Visit Regarding Geismar, LA,
Plant of Vulcan Materials Co., Jan. 4, 1978 (on file at EPA, ESED, Research
Triangle Park, NC).
3. D. G. Erikson, Storage and Handling (in preparation for EPA, ESED, Research
Triangle Park, NC).
4. D. G. Erikson and V. Kalcevic, Fugitive Emissions (in preparation for EPA, ESED,
Research Triangle Park, NC).
5. D. W. Smith, Du Pont, Wilmington, DL, letter to D. R. Goodwin, EPA, Mar. 23, 1978.
*Usually, when a reference is located at the end of a paragraph, it refers to
the entire paragraph. If another reference relates to certain portions of
that paragraph, that reference number is indicated on the material involved.
When the reference appears on a heading, it refers to all the text covered by
that heading.
-------
A-l
APPENDIX A
Table A-l. Physical Properties of Carbon Tetrachloride and
Tetrachloroethylene (Perchloroethylene)
Carbon Tetrachloride
Tetrachloroethylene
Synonym
Molecular formula
Molecular weight
Physical state
Vapor pressure
Vapor specific gravity
Boiling point
Melting point
Density
Water solubility
Tetrachloromethane, per-
chloromethane, methane
tetrachloride
cci4
153.82
Liquid
115.2 mm Hg at 25°C
5.32
76.54°C at 760 mm Hg
-22.99°C
1.5940 g/ml at 20°C/4°C
Insoluble
Perchloroethylene,
ethylene tetrachloride,
carbondlchloride,
tetrachloroethene
c cl
L2 4
165.82
Liquid
18.47 mm Hg at 25°C
5.83
121.20°C at 760 mm Hg
-19°C
1.6227 g/ml at 20°C/4°C
Insoluble
aFrom: J. Dorigan e_t al_._, "Carbon Tetrachloride," p. AI-222 in Scoring of Organic Air
Pollutants. Chemistry, Production and Toxicity of Selected Organic Chemicals
(Chemicals A-C), MTR-7248, Rev. 1, Appendix 1, Mitre Corp., McLean, VA (September 1976).
bFrom: J. Dorigan et. al_._, "Perchloroethylene," p. AIV-24 in Scoring of Organic Air
Pollutants. Chemistry, Production and Toxicity of Selected Organic Chemicals
(Chemicals O-Z), MTR-7248, Rev. 1, Appendix IV, Mitre Corp., McLean, VA (September 1976)
-------
B-l
APPENDIX B
FUGITIVE-EMISSION FACTORS*
The Environmental Protection Agency recently completed an extensive testing
program that resulted in updated fugitive-emission factors for petroleum re-
fineries. Other preliminary test results suggest that fugitive emissions from
sources in chemical plants are comparable to fugitive emissions from correspond-
ing sources in petroleum refineries. Therefore the emission factors established
for refineries are used in this report to estimate fugitive emissions from
organic chemical manufacture. These factors are presented below.
Source
Uncontrolled
Emission Factor
(kg/hr)
Controlled
Emission Factor'
(kg/hr)
Pump seals
Light-liquid service
Heavy-liquid service
Pipeline valves
Gas/vapor service
Light-liquid service
Heavy-liquid service
Safety/relief valves
Gas/vapor service
Light-liquid service
Heavy-liquid service
Compressor seals
Flanges
Drains
0.12
0.02
0.021
0.010
0.0003
0.16
0.006
0.009
0.44
0.00026
0.032
0.03
0.02
0.002
0.003
0.0003
0.061
0.006
0.009
0.11
0.00026
0.019
Based on monthly inspection of selected equipment; no inspection of
heavy-liquid equipment, flanges, or light-liquid relief valves,-
10,000 ppmv VOC concentration at source defines a leak; and 15 days
allowed for correction of leaks.
Light liquid means any liquid more volatile than kerosene.
*P.adian Corp., Emission Factors and Frequency of Leak Occurrence for Fittings
in Refinery Process Units, EPA 600/2-79-044 (February 1979).
-------
C-l
APPENDIX C
LIST OF EPA INFORMATION SOURCES
D. W. Smith, Du Pont, Wilmington, DL, letter to D. R. Goodwin, EPA, Mar. 23, 1978.
J. Beale, Dow Chemical, Midland, MI, letter to L. Evans, EPA, Mar. 1, 1978.
J. Beale, Dow Chemical, Midland, MI, letter to L. Evans, EPA, May 5, 1978.
P. Reis, Texas Air Control Board, Emissions Inventory Questionnaire, TACB
Account Number 104-137-1, Dow Chemical Co., Freeport, TX, data for 1975.
F. D. Hobbs, IT Enviroscience, Inc., Trip Report on Visit Regarding Geismar, LA,
Plant of Vulcan Materials Co., Jan. 4, 1978 (on file at EPA, ESED, Research
Triangle Park, NC).
F. D. Hobbs, IT Enviroscience, Inc., Trip Report on Visit Regarding South
Charleston, WV, Plant of FMC Corporation, Mar. 14, 1978 (on file at EPA, ESED,
Research Triangle Park, NC).
-------
D-l
APPENDIX D
EXISTING PLANT CONSIDERATIONS
A. INFORMATION SOURCES
The information used in preparing this report was gathered through a site visit
-. ^ Q
to one manufacturing location and from data supplied by producers. — Informa-
tion concerning reported emissions and control techniques known to be in use by
industry is presented in this appendix.
1. Dow Freeport, TX
Refrigerated condensers and pressurized-nitrogen padding are used to reduce emis-
sions from carbon tetrachloride storage, and pressurized-nitrogen padding is used
to reduce emissions from perchloroethylene storage. Vapor-balance, refrigerated
condensation, and recycle are all used to control emissions from hex-waste
handling and feed storage tanks. —
2. Du Pont—Corpus Christi, TX
7
This plant reportedly does not use the chlorinolysis process, but it does produce
carbon tetrachloride and perchloroethylene co-products and uses caustic scrubbing
2
for treatment of emissions. The VOC is stripped from the waste caustic and re-
cycled to the process.
3. Vulcan—Geismar, LA and Wichita, TX
Process emissions are reduced at both locations by separating inert gases in the
hydrogen chloride absorption and chlorine removal systems. At Geismer, LA, excess
chlorine is reacted with ethylene dichloride, which is recycled to the chlorinator.
The hydrogen chloride and inert gases are sent to the ethylene dichloride oxychlorin
tion process. In Wichita, KS, the hydrogen chloride is removed in an absorption
system. The chlorine and inert gases are dried and recycled to the reactor. The
Q
reactor purge is diverted to the chlorine sniff plant.
Reflux drums on the carbon tetrachloride and perchloroethylene distillation columns
are generally padded with low-pressure nitrogen. Crude product and the more volatil
feedstocks are stored in pressurized tanks to control emissions. A refrigerated
8
condenser reduces emissions from carbon tetrachloride storage at Geismar.
-------
D-2
4. Estimated Controlled VOC Emissions
It is estimated that about 15% of the total VOC emissions are controlled for the
domestic carbon tetrachloride—perchloroethylene chlorinolysis process industry.
This is a weighted average of the following individual estimated projections:
Source VOC Controlled (%)
Process 0
Storage 20
Handling 0
Fugitive 0
Hex-waste handling and disposal 95
and waste hydrocarbon storage
Waste caustic 45
-------
D-3
B. REFERENCES*
1. F. D. Hobbs, IT Enviroscience, Inc., Trip Report on Visit Regarding Geismar,
LA, Plant of Vulcan Materials Co., Jan. 4, 1978 (on file at EPA, ESED, Research
Triangle Park, NC).
2. D. W. Smith, Du Pont, Wilmington, DL, Letter dated Mar. 23, 1978, to D. R. Goodwin.
3. J. Beale, Dow Chemical, Midland, MI, letter dated Mar. 1, 1978 to L. Evans, EPA.
4. J. Beale, Dow Chemical, Midland, MI, letter dated May 5, 1978 to L. Evans, EPA.
5. P. Reis, Texas Air Control Board, Emissions Inventory Questionnaire, TACB
Account Number 104-137-1, Dow Chemical Co., Freeport, TX, data for 1975.
6. J. R. Cooper, Du Pont, Wilmington, DL, letter dated July 25, 1979, to D. R. Patrick,
EPA.
7. J. R. Cooper, Du Pont, Wilmington, DL, letter dated Sept. 27, 1979 to J. R. Farmer,
EPA.
8. T. A. Robinson, Vulcan Materials Company, Wichita, KS, letter dated July 9, 1979,
to D. R. Patrick, EPA.
*Usually, when a reference is located at the end of a paragraph, it refers to
the entire paragraph. If another reference relates to certain portions of
that paragraph, that reference number is indicated on the material involved.
When the reference appears on a heading, it refers to all the text covered by
that heading.
-------
3-i
REPORT 3
FLUOROCARBONS
(ABBREVIATED REPORT)
David M. Pitts
IT Enviroscience
9041 Executive Park Drive
Knoxville, Tennessee 37923
Prepared for
Emissions Standards and Engineering Division
Office of Air Quality Planning and Standards
ENVIRONMENTAL PROTECTION AGENCY
Research Triangle Park, North Carolina
March 1980
This report contains certain information which has been extracted from the
Chemical Economics Handbook, Stanford Research Institute. Wherever used, it
has been so noted. The proprietary data rights which reside with Stanford
Research Institute must be recognized with any use of this material.
D23K
-------
3-iii
CONTENTS OF REPORT 3
Page
I. ABBREVIATIONS AND CONVERSION FACTORS 1-1
II. INDUSTRY DESCRIPTION H-l
A. Introduction II-l
B. Usage and Growth I1"1
C. Domestic Producers II-2
D. References 11-6
III. PROCESS DESCRIPTIONS III-l
A. Introduction III-l
B. Liquid-Phase Reaction of HF and Chlorinated Hydrocarbon III-l
C. Process Variations III-5
D. References III-7
IV. EMISSIONS IV-1
A. Typical Plants IV-1
B. Process Sources and Emissions IV-1
C. Storage Emissions IV-6
D. References IV~9
V. APPLICABLE CONTROL SYSTEMS V-l
A. Emission Control for Typical Plants V-l
B. References v~5
APPENDICES OF REPORT 3
Page
A. PHYSICAL PROPERTIES OF FLUOROCARBON COMPOUNDS A-l
B. EXISTING INDUSTRIAL EMISSION CONTROL DEVICES B-l
-------
3-v
TABLES OF REPORT 3
Number Pa9e
II-l Fluorocarbon Producers and Capacities H~3
IV-1 Summary of Uncontrolled VOC Emissions from Fluorocarbon Processes IV-3
IV-2 Fluorocarbon-12/11 Uncontrolled Process Emissions from IV-4
Fluorocarbon 12 Distillation
IV-3 Fluorocarbon-22 Uncontrolled Process Emissions from IV-5
Fluorocarbon-23/22 Distillations
IV-4 Fluorocarbon-113/114 Uncontrolled Process Emissions from Product IV-7
Recovery Distillations
IV-5 Uncontrolled Raw-Material Storage Emissions IV-8
V-l Estimated Emission Ratios for Industry V-3
A-l Physical Properties of Flurocarbon Compounds A-3
B-l Existing Industrial Emission Control Devices B-3
FIGURES OF REPORT 3
Number
II-l Locations of Fluorocarbons Manufacturing Facilities II-4
III-l Process Flow Diagram for Uncontrolled Fluorocarbons by III-3
Liquid-Phase Reaction
-------
1-1
ABBREVIATIONS AND CONVERSION FACTORS
EPA policy is to express all measurements used in agency documents in metric
units. Listed below are the International System of Units (SI) abbreviations
and conversion factors for this report.
To Convert From
Pascal (Pa)
Joule (J)
Degree Celsius (°C)
Meter (m)
Cubic meter (m3)
Cubic meter (m3)
Cubic meter (m3)
Cubic meter/second
(m3/s)
Watt (W)
Meter (m)
Pascal (Pa)
Kilogram (kg)
Joule (J)
To
Atmosphere (760 mm Hg)
British thermal unit (Btu)
Degree Fahrenheit (°F)
Feet (ft)
Cubic feet (ft3)
Barrel (oil) (bbl)
Gallon (U.S. liquid) (gal)
Gallon (U.S. liquid)/min
(gpm)
Horsepower (electric) (hp)
Inch (in.)
Pound-force/inch2 (psi)
Pound-mass (Ib)
Watt-hour (Wh)
Multiply By
9.870 X 10"6
9.480 X 10~4
(°C X 9/5) + 32
3.28
3.531 X 101
6.290
2.643 X 102
1.585 X 104
1.340 X 10"3
3.937 X 101
1.450 X 10~4
2.205
2.778 X 10"4
Standard Conditions
68°F = 20°C
1 atmosphere = 101,325 Pascals
PREFIXES
Prefix
T
G
M
k
m
H
Symbol
tera
giga
mega
kilo
milli
micro
Multiplication
Factor
1012
109
106
103
10"3
io"6
Example
1 Tg = 1 X IO12 grams
1 Gg = 1 X IO9 grams
1 Mg = 1 X IO6 grams
1 km = 1 X IO3 meters
1 mV = 1 X IO"3 volt
1 |jg = 1 X IO"6 gram
-------
II-l
II. INDUSTRY DESCRIPTION
A. INTRODUCTION
Fluorocarbon production was selected for study because preliminary estimates
indicated that emissions of volatile organic compounds (VOC) are high and because
the chlorinated hydrocarbon raw materials are relatively toxic. Fluorocarbons
may also play a role in the destruction of the earth's ozone layer.
There are five major fluorocarbons that represent at least 95% of the total pro-
duction of fluorinated hydrocarbons: trichlorofluoromethane (fluorocarbon 11),
dichlorodifluoromethane (fluorocarbon 12), trichlorotrifluoroethane (fluoro-
carbon 113), dichlorotetrafluoroethane (fluorocarbon 114), and chlorodifluoro-
methane (fluorocarbon 22).1 The processes for producing these fluorocarbons are
described in this report. Other commercially produced fluorocarbons are chloro-
pentafluoroethane (fluorocarbon 115), bromotrifuloromethane (fluorocarbon 13B1),
tetrafluoromethane (fluorocarbon 14), and hexafluoroethane (fluorocarbon 116),
which, combined, represent <5% of the total fluorocarbon production and therefore
are not considered in this report.
Fluorocarbons 12, 22, and 114 are gases at ambient temperature, and fluorocarbons
11 and 113 are liquids. Appendix A lists the pertinent physical properties of
2
these five important fluorocarbons.
Fluorocarbons 11 and 12 are normally produced in an integrated facility, as are
fluorocarbons 113 and 114. Fluorocarbon 22 is normally produced in its own
facility. The production of fluorocarbons involves the use of anhydrous hydrogen
fluoride (HF) to successively replace chlorine with fluorine.
B. USAGE AND GROWTH
Approximately $400 million worth of fluorocarbons was consumed in 1977. This
total includes the estimated value of captive consumption by basic producers.
At an average price of $0.88 per kg this amounts to a total consumption of 454 Gg
in 1977.
Historically, about 50% of all fluorocarbons produced have been used as aerosol
propellants. However, the ozone controversy, which began in late 1974, has
-------
II-2
caused a decline in the use of aerosols and therefore a decrease in fluorocarbon
consumption for this application to approximately 24% in 1978. The principal
2 4
compounds used as aerosol propellants are fluorocarbons 11, 12, 113, and 114. —
Nonessential uses of fluorocarbon propellants were scheduled to be banned in 1978.
The first phase of the EPA's program was that manufacturers stop making fluoro-
carbons for aerosols by October 1978. Approximately 2 or 3% of the original
fluorocarbons used as propellants were considered to be essential. The use of
4
fluorocarbons as propellants was estimated to shrink to this level by 1979.
Refrigerants, now the largest application for fluorocarbons, account for an esti-
mated 39% of the consumption, up from a historical level of 30%. Fluorocarbon
refrigerants are expected to have a slow but steady growth through 1981. The
refrigerant most commonly employed is fluorocarbon 12, found in most home refrig-
erators and many commercial freezer and display cases. Much of the air condition-
ing industry is served by fluorocarbon 22 for small equipment and fluorocarbon 11
2 4
for large centrifugal compressors. —
Other significant uses of fluorocarbons are as blowing agents, plastics, and sol-
vents. Specifically, fluorocarbon 11 is used as a blowing agent to increase the
thermal insulation properties of urethane foams. The overall consumption of
fluorocarbons is forecast to remain relatively level until 1980, with the decline
of aerosol propellants being offset by the increasing use of fluorocarbons as
2 3
refrigerants, blowing agents, and plastic materials. ' A slow but steady growth
4
rate of 5 or 6% from 1980 to 1983 is forecast for all fluorocarbons.
C. DOMESTIC PRODUCERS
There are 5 major producers of fluorocarbons in the United States at 12 plants.
Supply and demand came into better balance in 1978 with the prior closing of
plants by Du Pont, Penwalt, and Union Carbide. Table II-l lists the producers,
plant locations, and overall annual 1979 capacities for each company. The loca-
tions4 of fluorocarbon production facilities are shown in Fig. II-l.
-------
II-3
Table II-l. Flurocarbon Producers and Capacities
Company
Location
Annual
Capacity
(Gg/yr)
E. I. du Pont de
Nemours and Co.
Allied Chemical Corp.
Kaiser Aluminum and
Chemical Corp.
Penwalt Corp.
Essex Chemical Corp.
Total
Antioch, CA
Corpus Christi, TX
Deepwater, NJ
Louisville, KY
Montague, MI
Baton Rouge, LA
Danville, IL
Elizabeth, NJ
El Segundo, CA
Gramercy, LA
Calvert City, KY
Wichita, KA
227
182"
29.5
36
20.5
495
1979 capacity does not
and Union Carbide.
Includes some capacity
and Elizabeth, NJ.
include plants closed by Du Pont, Penwalt,
that has been added at Baton Rouge, LA,
-------
II-4
1. Dupont, Antioch, CA
2. Dupont, Corpus Christ!,
3. Dupont, Deepwater, NJ
4. Duoont, Louisville, KY
5. Dupont, Montague, MI
6. Allied, Baton Rouge, LA
7. Allied, Danville, IL
TX
8. Allied, Elizabeth, NJ
9. Allied, El Segundo, CA
10. Kaiser, Gramercy, LA
11. Penwalt, Calvert City, KY
12. Penwalt, Thorofare, NJ
13. Essex, Wichita, KS
Fig. II-l- Locations of Fluorocarbons Manufacturing Facilities
-------
II-5
Data for 1978 indicated an estimated total production of 413 Gg split as follows.-
159 Gg for fluorocarbon 12; 89 Gg for fluorocarbon 11; 91 Gg for fluorocarbon 22;
and 74 Gg for other fluorocarbons, which include fluorocarbons 113, 114, and 115.
Therefore fluorocarbons 12, 11, and 22 have been estimated to represent 82% of
the total 1978 fluorocarbon production.
-------
II-6
D. REFERENCES*
1. R. F. Bradley, "Fluorinated Hydrocarbons Salient Statistics," p. 658.2030C in
Chemical Economics Handbook, Stanford Research Institute, Menlo Park, CA
(September 1975).
2. R. C. Downing, "Fluorinated Hydrocarbons," pp. 739—747 in Kirk-Othmer
Encyclopedia of Chemical Technology, 2d ed., vol. 9, edited by A. Standen et
a1., Wiley-Interscience, New York, 1966.
3. "Fluorocarbons," pp. 141, 142 in Kline Guide to the Chemical Industry, 3d ed.,
edited by M. K. Meegan, Charles H. Kline and Co., Fairfield, NJ, 1977.
4. 1979 Directory of Chemical Producers. United States of America, p. 636, SRI
International, Menlo Park, CA.
5. "Fluorocarbons," Chemical Products Synopsis, Mannsville Chemical Products,
Mannsville, New York, June 1978.
*When a reference number is used at the end of a paragraph or on a heading,
it usually refers to the entire paragraph or material under the heading.
When, however, an additional reference is required for only a certain portion
of the paragraph or captioned material, the earlier reference number may not
apply to that particular portion.
-------
III-l
III. PROCESS DESCRIPTIONS
A. INTRODUCTION
As previously discussed, the five major fluorocarbons are F-ll, -12, -22, -113,
and -114, representing >95% of the total domestic production of fluorinated hydro-
carbons.1 The only commercially important domestic process for the production of
fluorocarbons involves the liquid-phase catalytic reaction of anhydrous hydrogen
fluoride and chlorinated hydrocarbons. The catalytic vapor-phase reaction has
been used commercially, although much less generally than the liquid-phase process.
The only foreign process for fluorocarbon production (not being practiced in the
United States) involves the single-step reaction of hydrocarbons with chlorine and
hydrogen fluoride and eliminates the requirement for an intermediate chlorinated
hydrocarbon feedstock. A process based on this type of reaction has been developed
by Montedison in Italy. At present there are no known plans to introduce this
o
process domestically. This report covers only the process involving the liquid-
phase reaction of hydrogen fluoride and chlorinated hydrocarbons.
B. LIQUID-PHASE REACTION OF HF AND CHLORINATED HYDROCARBONS
1. Basic Process
Fluorocarbons are produced by the following idealized chemical reactions .-
1,2
Fluorocarbons 11 and 12
2CC14
(carbon tetra-
chloride)
+ 3HF
(anhydrous
hydrogen
fluoride)
(trichloro-
fluoro-
me thane)
(dichloro-
difluoro-
me thane)
3HC1
(hydrochloric
acid)
Fluorocarbon 22
CHC13
(chloroform)
+ 2HF
(anhydrous
hydrogen
fluoride)
catalyst
CHC1F2
(chlorodifluoro-
methane)
2HC1
(hydrochloric
acid)
-------
III-2
Fluorocarbons 113 and 114
2C12C=CC12
(perchloro-
ethylene)
. -,,,_ . ^r1 catalyst v „ „, „
T /tiC T /C.l_
(anhydrous (chlorine)
hydrogen
fluoride)
' ^3*3
(trichloro-
trifluoro-
e thane)
+ C2C12F4
(dichloro
tetra-
fluoro-
+ 7HC1
(hydro-
chloric
acid)
ethane)
Pentavalent antimony functions as the catalyst for all the reactions. Chlorine
is added to control the pentavelent activity of the catalyst, which is dissolved
in an equilibrium mixture of chlorinated hydrocarbon feed plus partly fluorinated
intermediates. Reactor temperatures vary from 45 to 200°C and pressures vary
from 1 X 10 to 3.5 X 10 Pa, depending on the feed and products involved. The
specific reaction conditions are discussed extensively in various process
?
patents.
The important 2-carbon-atom fluorocarbons (113 and 114) could be produced from
hexachloroethane feed. The high melting point of hexachloroethane (186°C),
however, makes it more convenient to use perchloroethylene plus chlorine, as
indicated by the third reaction.
The process flow diagram shown in Fig. III-l represents a typical continuous
process for the liquid-phase reaction, whereby any of the three groups of fluoro-
carbons listed above can be made, depending on the chlorinated hydrocarbon feed-
stock used. Although the process represented by Fig. III-l can be block operated
to produce each of the three sets of fluorocarbon products, fluorocarbons 11
and 12 are normally produced together in their own facility, as are fluorocarbons
113 and 114. Fluorocarbon 22 is normally produced at its own facility. —
The liquid-phase process for fluorocarbon manufacture as represented in Fig. III-l
consists basically of a heated reaction vessel containing the catalyst (SbCl5)
dissolved in chlorinated feed and partly fluorinated intermediates, to which
the feed materials are added in liquid form. The reactor is surmounted by a
distillation column and condenser, which separate the reactor vapors into a
high-boiling fraction containing catalyst, unreacted chlorinated hydrocarbon,
underfluorinated product, and some HF that are returned to the reactor, and into
-------
V
#>
a
crta
\?
STEAM I
,0 J
r~Tr)
^>
JR.OUL-'C-T RE.COV £_P. V C-O_UK*SJ
I ; PC tjr
1 Al-U^tH-JA
r_J JCTI^ATFO
'LIC \ \C^1 OP P M
l^» (ELD TO THC- TirCOMO
Ct.VC-P-V CCUUUU ^OIl
P F--U4; AMD STRH.AM
.C't >V)L. r r>cUT TO
Fig. III-l. Process Flow Diagram for Uncontrolled Fluorocarbons by Liquid-Phase Reaction
-------
III-4
an overhead fraction containing HCl, some unreacted HF, and the desired plant
products. The rest of the process equipment consists of facilities for separat-
ing and recovering the HCl, recovering and purifying the products, and recycling
the underfluorinated material and HF to the reactor.2— Operation of the process
is as follows .-
Dry chlorinated hydrocarbon feed (stream 1), liquid anhydrous HF (stream 2),
and chlorine (stream 3) are pumped from storage to the reactor, which contains
the catalyst components.
The recycled bottoms from the product recovery column (stream 15) and the HF
recycle stream (9) are also fed to the reactor, which operates at a temperature
and pressure level dictated by the volatility of the fluorocarbons being produced.
The reactor is provided with a steam-heated forced-circulation reboiler.
Vapor from the reactor (stream 4) enters the first distillation-stripping column,
which is controlled to remove the net HCl, the desired fluorocarbon products,
and some HF overhead and to return to the reactor any vaporized catalyst, uncon-
verted and underfluorinated chlorinated hydrocarbon feed, and some HF (stream 5).
The overhead stream (6) is totally condensed and pumped to the HCl recovery
2 5
column, which operates at an elevated pressure. —
Anhydrous HCl by-product (stream 7) is taken overhead from the HCl recovery
column, totally condensed, and transferred to pressurized storage as a liquid.
The inert gases that enter the system with the chlorine gas are purged from the
HCl accumulator. This vent is normally not a source of VOC emission. The bottoms
from the HCl recovery column (stream 8) are chilled until two liquid phases form,
which are separated in the phase separator. The top HF phase (stream 9), which
contains a small amount of dissolved fluorocarbons, is recycled to the reactor.
The bottom phase (stream 10), which contains the fluorocarbons plus trace amounts
of HF and HCl, is expanded and sent through a caustic scrubber to neutralize
the HF and HCl. The stream is then dried in an H2S04 drying column followed by
an activated alumina dryer. The spent salts from the caustic scrubber and the
spent H SO and activated alumina (streams 5) represent potential sources of
24 2/3
secondary emissions from the process.
-------
III-5
The neutralized and dried fluorocarbon mixture (stream 11) is compressed and
sent to a series of distillation columns to remove the overfluorinated com-
pounds. The products are taken as bottoms or overheads from these distillation
columns, depending on the fluorocarbons being produced. In fluorocarbon-12/11
manufacture, fluorocarbon 12 is taken overhead in the first column and the dried
product (stream 12) is sent to pressurized storage. The bottoms from this distil-
lation (stream 13) are sent to the second distillation column for removal of
fluorocarbon 11 overhead as product (stream 14), which is sent to pressurized
storage. As stated previously, the bottoms from the second distillation
2 5
(stream 15) are recycled to the reactor. —
In fluorocarbon-22 manufacture, overfluorinated material (fluorocarbon 23) is
removed and purged overhead from the first column and fluorocarbon 22 is
3 4
recovered overhead from the second column. '
In fluorocarbon-113/114 manufacture, fluorocarbon 113 could be taken off the
bottom of the first distillation column after HCl is removed. The overheads
from this column could then be fed to the second column for overhead recovery
of fluorocarbon 114. Overfluorinated material would be vented from the con-
denser of the second column. In all cases the gas streams leaving the conden-
2 5
sers of the distillation train are potential sources of VOC emissions. —
C. PROCESS VARIATIONS
A number of process variations exist in the processing of fluorocarbons both
between the different fluorocarbon products and among the different producers.
In general the number of distillation columns for removal of underfluorinated
and overfluorinated material and for product purification and recovery can vary,
although two stills are shown in Fig. III-l. Phase separation of HF can take
place before or after HCl is removed and will affect the number and type of
3 4
distillations required. '
The HCl removal system can vary with respect to the method of removal and the
type of by-product acid obtained. Figure III-l shows the recovery of anhydrous
HCl by distillation before phase separation and HF recycle. Other alternatives
3,4
for HCl recovery and/or removal are the following:
-------
III-6
1. After anhydrous HCI has been obtained as in Fig. III-l, it can be further
purified and absorbed in water to make concentrated technical or food-grade
HCI. The absorption step can result in a potential VOC emission. —
2. The condensed overhead from the catalyst distillation (stream 6 in
Fig. III-l) can be treated with water to recover an aqueous solution of
HCI contaminated with HF and possibly some fluorocarbons. Phase separa-
tion and HF recycle are not carried out if this procedure is employed.
The aqueous HCI solution could possibly be sold but is more likely to be
3 4
disposed of, resulting in a potential secondary emission. ' This pro-
cedure is typical of older plants in the industry.
3. In the production of fluorocarbons 113/114, phase separation is commonly
carried out before HCI is removed. The HCI is then separated by distil-
lation and combined with the overhead vapor from the fluorocarbon-113
recovery distillation before it is absorbed. As in alternative 2, the
aqueous HCI solution obtained can either be sold or be disposed of,
depending on the degree of purification and the market for by-product HCI.
Disposal could result in secondary emissions. '
-------
III-7
D. REFERENCES*
1. R. F. Bradley, "Fluorinated Hydrocarbons Salient Statistics," pp. 658.2030A--E
in Chemical Economics Handbook, Stanford Research Institute, Menlo Park, CA
(September 1975).
2. H. W. Scheeline, Report No. 89. Hydrofluoric Acid and Fluorocarbons, A private
report by the Process Economics Program, Stanford Research Institute, Menlo Park,
CA (November 1973).
3. David M. Pitts, IT Enviroscience, Inc., Trip Report on Site Visit to Allied Chemical
Corp., Morristown, NJ, Mar. 16, 1968 (on file at the EPA, ESED, Research Triangle
Park, NC).
4. Donald W. Smith, E. I. du Pont de Nemours & Company, letter dated Aug. 21, 1978,
regarding fluorocarbon manufacture at the Louisville plant, in response to EPA's
request for information on emissions data on fluorocarbon production facilities.
5. Donald W. Smith, E. I. du Pont de Nemours & Company, letter dated June 7, 1978
regarding fluorocarbon process emissions at the Chambers Works, Corpus Christi,
Montague, and Antioch plants, in response to EPA's request for information on
emissions data on fluorocarbon production facilities.
*When a reference number is used at the end of a paragraph or on a heading,
it usually refers to the entire paragraph or material under the heading.
When, however, an additional reference is required for only a certain portion
of the paragraph or captioned material, the earlier reference number may not
apply to that particular portion.
-------
IV-1
IV. EMISSIONS
Emissions in this report are usually identified in terms of volatile organic
compounds (VOC). VOC are currently considered by the EPA to be those of a large
group of organic chemicals, most of which, when emitted to the atmosphere, par-
ticipate in photochemical reactions producing ozone. A relatively small number
of organic chemicals have low or negligible photochemical reactivity. However,
many of these organic chemicals are of concern and may be subject to regulation
by EPA under Section 111 or 112 of the Clean Air Act since there are associated
health or welfare impacts other than those related to ozone formation. It should
be noted that although fluorocarbons 11, 12, 23, 113, 114, and 115 are included
in VOC emission totals in this report, they do not, based on current research
data, participate in ozone-forming reactions to an appreciable extent.
A. TYPICAL PLANTS
The capacity of the typical integrated plant for the production of fluorocar-
bons 11 and 12 is 7576 kg/hr total, or 66.36 Gg/yr based on 8760* hr of operation
per year. The capacity of the typical plant for the production of fluorocarbon 22
is 947 kg/hr, or 8.3 Gg/yr based on 8760* hr of operation per year. The capacity
of the typical integrated plant for the production of fluorocarbons 113 and 114
is 2200 kg/hr total, or 19.3 Gg/yr based on 8760 hr of operation per year. These
plants all use the typical process described in Sect. III.
B. PROCESS SOURCES AND EMISSIONS
As indicated in Fig. III-l, three potential sources of process emissions in the
manufacture of the fluorocarbons are considered in this report. The vent (B,
Fig. III-l) from the HCl recovery column accumulator purges noncondensables and
the very small amounts of inert gases entering the system with the chlorine
gas. — No data are available on the emissions from that source, which has
the potential to emit minimum boiling azeotropes of the highly fluorinated ethanes
and methanes if they are formed in the reactor. The two vents (C, Fig III-l)
from the product recovery distillation columns purge the overfluorinated lights
*Process downtime is normally expected to range from 5 to 15%. If the hourly
rate remains constant, the annual production and annual VOC emissions will be
correspondingly reduced. Control devices will usually operate on the same
cycle as the process. From the standpoint of cost-effectiveness calculations
the error introduced by assuming continuous operation is negligible.
-------
IV-2
and possibly some product from the system and do represent sources of VOC emis-
sions. The emissions from these vents vary among the different products and
may be handled differently by different producers. — The composition of the
emissions varies among producers, and even more so between older and newer plants.
Optimization of catalyst activity to obtain the maximum yield of product at a
high reaction rate is very important in plant operation and hence is considered
to be confidential information. Differences in how catalyst activity is controllec
will be reflected in the differences in the emissions. Emission rates for the
liquid-phase fluorocarbon process as a function of fluorocarbon products pro-
duced and typical production rates for each fluorocarbon process are summarized
in Table IV-1.
1. Fluorocarbons-12/11 Process Emissions
In the production of fluorocarbons 11 and 12, gases are purged from the over-
head stream from the first distillation, the fluorocarbon-12 recovery column.
This emission contains fluorocarbon 12, inert gases such as air, and any fluoro-
carbon 13 that has been produced. Uncontrolled emissions from this source have
been calculated from measured composition data on controlled emissions ' and
4
are based on the operating conditions given in the report on production of hydro-
fluoric acid and fluorocarbons. The composition of and the emission rate for
the uncontrolled emissions are summarized in Table IV-2.
2. Fluorocarbon-22 Process Emissions
In the production of fluorocarbon 22 any overfluorinated material (fluorocar-
bon 23) produced is vented from the first distillation column, the fluorocar-
bon-23 separation column, along with inert gases and some fluorocarbon 22.
Fluorocarbon 22 and inert gases are vented from the condenser of the second
distillation, the fluorocarbon-22 purification column. Uncontrolled emissions
from these sources have been calculated from data on the measured amounts of
fluorocarbon-23 generation and from composition data based on estimated amounts
2
of inert gases and vapor pressure. The typical uncontrolled composition and
combined emission rate for these sources are summarized in Table IV-3.
-------
Table IV-1. Summary of Uncontrolled VOC Emissions from Fluorocarbon Processes
...
_
From F-12/11;
PR.3 7576 ka/hr
Source
Distillation
vents
Storage (raw material)
Total
Vent
Designation
(Fia III-l)
V r J.y . x -*--"- •*• '
c
A
Ratiob Rate
(kq/kq) (kg/hr)
0.00293
0.000185
0.00312
22.48
1.40
23.88
Emissions
. •
From F-22;
PR, 947 kg/hr
b
Ratio
(kg/kg)
0.01647
0.00254
0.01901
Rate
(kg/hr)
15.6
2.41
18.01
From F-113/114;
PR, 2200 kq/hr
. b
Ratio
(kq/kg)
0.00542
0.00118
0.0066
Rate
(kg/hr)
11.93
2.59
14.52
H
f
U)
= production rate.
bkg of VOC per kg of fluorocarbons(s) produced.
-------
IV-4
Table IV-2. Fluorocarbon-12/11 Uncontrolled
Process Emissions from
Fluorocarbon-12 Distillation
Component
Fluorocarbon 12^1
) voc
Fluorocarbon 13 J
Total VOC
Inert gases
Total
Composition
(wt %)
95.05
0.94
95.99
4.01
100.0
Emission Rate
(kg/hr)
22.26
0.22
22.48
0.94
23.42
From refs 1 and 3.
Based on typical production capacity of 7576 kg/hr of total
fluorocarbons 11 and 12.
-------
IV-5
Table IV-3. Fluorocarbon-22 Uncontrolled Process
Emissions from Fluorocarbon-23/22 Distillations
Component
Fluorocarbon 23 "1
> voc
Fluorocarbon 22 J
Total VOC
Inert gases
Total
Composition
(wt %)
62.6
31.3
93.9
6.1
100.0
b
Emission Rate
(kg/hr)
10.4
5.2
15.6
1.0
16.6
From refs 1 and 2.
Based on typical production capacity of 947 kg/hr of
fluorocarbon 22.
-------
IV-6
3. Fluorocarbon-113/114 Process Emissions
In the production of fluorocarbons 113/114, inert gases and overfluorinated
fluorocarbons are purged from the product recovery distillation columns
(vents C, Fig. III-l). The actual configuration of the distillation train for
recovery of products in a facility designed specifically to produce fluoro-
carbons 113 and 114 would be somewhat different from the two-column operation
presented in Fig. III-l, which is meant to represent a typical general fluoro-
carbons plant. In practice, all overfluorinated fluorocarbons produced will be
emitted to the atmosphere from the distillation train no matter what the con-
figuration. Variance will be with respect to the amount of product fluoro-
carbon 114 emitted. '
Reported emissions based on measured composition data from the product recovery
distillation vents are summarized in Table IV-4 based on a facility with a
typical combined production rate of 2200 kg/hr for fluorocarbons 113 and 114.
These data reflect the use of a proprietary process system that is reported to
reduce the amount of fluorocarbon 114 emitted.
C. STORAGE EMISSIONS
Emissions result from storage of the chlorinated hydrocarbon raw materials.
Storage emission sources for the typical fluorocarbons plant are shown in
Fig. III-l (streams A). Emission estimates, based on calculations of the
uncontrolled breathing and working losses associated with raw material storage
in fixed-roof tanks, are presented in Table IV-5 for each of the fluorocarbons
processes discussed in this report. — The plant capacities associated with
the data are also given in Table IV-5. The bases and assumptions for the infor-
mation in Table IV-5 (tank sizes, turnovers, temperature variations, etc.) were
not given by the manufacturers who made the estimates. Because they are stored
in pressure vessels, no emissions are associated with the storage of fluorocarbon
products.
-------
IV-7
Table IV-4. Fluorocarbon-113/114 Uncontrolled
Process Emissions from
Product Recovery Distillations
Component
Fluorocarbon 114^
Fluorocarbon 13
Fluorocarbon 115
Fluorocarbon 124
Fluorocarbon 123
Higher boilers _/•
Total VOC
Inert gases
Total
Composition
(wt %)
21
14
) VOC °
2
0
1
41
58
100
.7
.8
.9
.3
.1
.3
.1
.9
Emission Rate
(kg/hr)
6.3
4.3
0.26
0.66
0.04
0.37
11.93
17.05
28.98
From ref 1.
Based on typical production capacity of
2200 kg/hr total for fluorocarbons 113 and 114.
-------
IV-8
Table IV-5. Uncontrolled Raw-Material Storage Emissions'
Emissions
Product
Fluorocarbons 12/11
Fluorocarbon 22
Fluorocarbons 113/114
Raw Material
Carbon tetrachloride
Chloroform
Perchloroethylene
Ratiob
(kg/kg)
0.000185
0.00254
0.00118
Rate
(kg/hr)
1.40C
d
2.41
2.59e
From ref 1.
kg of emission per kg of fluorocarbon produced.
£
Based on total production rate of 7576 kg/hr.
jBased on total production rate of 947 kg/hr.
Based on total production rate of 2200 kg/hr.
-------
IV-9
E. REFERENCES*
1. David M. Pitts, IT Enviroscience, Inc., Trip Report on Site Visit to Allied Chemical
Corp., Morristown, NJ, Mar. 16, 1978 (on file at the EPA, ESED, Research Triangle
Park, NC).
2. Donald W. Smith, E. I. du Pont de Nemours & Company, letter dated Aug. 21, 1978,
regarding fluorocarbon manufacture at the Louisville plant, in response to EPA1s
request for information on emissions data on fluorocarbon production facilities.
3. Donale W. Smith, E. I. du Pont de Nemours & Company, letter dated June 7, 1978,
regarding fluorocarbon process emissions at the Chambers Works, Corpus Christi,
Montague, and Antioch plants, in response to EPA's request for information on
emissions data on fluorocarbon production facilities.
4. H. W. Scheeline, Hydrofluoric Acid and Fluorocarbons, Report No. 89, Process
Economics Program, Stanford Research Institute, Menlo Park, CA (November 1973).
*When a reference number is used at the end of a paragraph or on a heading, it
usually refers to the entire paragraph or material under the heading. When,
however, an additional reference is required for only a certain portion of the
paragraph or captioned material, the earlier reference number may not apply to
that particular portion.
-------
V-l
V. APPLICABLE CONTROL SYSTEMS
A. EMISSION CONTROL FOR TYPICAL PLANTS
1. Process Emissions
As is indicated in Sect. IV, the process emissions from the liquid-phase
fluorocarbon processes consist of product and overfluorinated by-products that
emerge overhead from the product recovery and/or lights removal distillations.
The information available from the industry indicates that condensation, absorp-
tion, and product recycle are used to control product emissions. No add-on con-
trol technologies are used for the control of by-product (overfluorinated fluoro-
carbons) emissions, which are dependent on reaction conditions and the amount
of overfluorinated material produced. Reaction conditions are normally mani-
pulated to inhibit the formation of overfluorinated materials to the extent
•u-i ! 3
possible. —
In the production of fluorocarbons 11 and 12 Allied Chemical Co. uses a small
purge condenser with -20.5°C brine coolant and a carbon tetrachloride feedstock
scrubber to remove fluorocarbon 12 and some of the fluorocarbon 13 present from
the fluorocarbon-12 distillation vent. The emissions reported from the scrubber
vent are 3.04 kg/hr of fluorocarbon 12, 0.03 kg/hr of fluorocarbon 13, and
0.171 kg/hr of carbon tetrachloride based on the typical total production rate
of 7576 kg/hr. Some carbon tetrachloride, however, is traded for the fluoro-
carbon recovered in the emission resulting from this control system, thus reducing
the actual total VOC reduction efficiency. For this particular case condensation
at -17.8°C at the system pressure has been estimated to have an overall VOC
removal efficiency of 83.5%. The removal efficiency of a condenser is a func-
tion of the temperature and pressure at which it is operated, and higher
efficiencies are possible. The total system, including the condenser and carbon
tetrachloride scrubber, is estimated to reduce fluorocarbon emissions by 86.3%
and overall VOC emissions by 85.5%. Allied has estimated that this system has
an efficiency of 99% based on the removal of fluorocarbon 12 only. No cost
information on this control system was obtained.
In the production of fluorocarbon 22 Allied uses a refrigerated purge condenser
to recover fluorocarbon 22 from the inert gases and fluorocarbon 23 vented from
-------
V-2
the fluorocarbon-23 distillation column. This condenser is estimated to be 75%
efficient with respect to recovery of fluorocarbon 22. However, since virtually
all the fluorocarbon 23 made in the process is vented, the condenser is estimated
to be only 25% efficient with respect to overall VOC removal.
Allied controls the emission from the fluorocarbon-22 distillation column by
recycling the vent stream from the condenser back to the compressor. Du Pont
data indicate that they recover fluorocarbon 23 by condensation after the low
boilers are removed and before fluorocarbon 22 is recovered. The refrigerated
vent condenser is reported to be 80% efficient with respect to fluorocarbon-23
and overall VOC removal. A refrigerated condenser is also used to recover
fluorocarbon 22 from the fluorocarbon-22 recovery and purification system vent.
This condenser is reported to be 76% efficient with respect to fluorocarbon-22
and overall VOC removal. No cost data were obtained on these condenser systems.
In the production of fluorocarbons 113/114 Allied uses a proprietary process
modification to recover fluorocarbon 114 from the overfluorinated materials vented
from the process.1 In all fluorocarbon production refrigerated vent condensers
could be used to reduce the emissions of the overfluorinated by-products, which
are normally vented. These recovered materials would then have to be decomposed
or disposed of in another manner.
2. Storage Emissions
Emissions of chlorinated hydrocarbon raw materials can be reduced by the use of
refrigerated condensers on the storage tank vents. Du Pont reports that a con-
denser using -17°C brine removes 66% of the chloroform emissions from the chloro-
2
form storage tank in the fluorocarbon-22 process.
3. Current Emission Controls
Emission control devices currently used by some domestic commercial fluoro-
carbon producers are shown in Appendix B.
4. Industry Emissions
From emission data reported by commercial fluorocarbon manufacturers
emission ratios as a function of fluorocarbon produced have been estimated and
are shown in Table V-l. Secondary and fugitive emissions are not considered.
-------
V-3
Table V-l. Estimated Emission Ratios for Industry
Emission Ratios (g/kg)
for Production of
Emission Source
Distillation vents
Raw material storage
Total0
F-12/1
1.68
0.185
1.87
1 F-22
14.41
1.70
16.11
F-113/114
5.42
1.18
6.60
Total Emission Ratios
for All Fluorocarbons
5.15
0.70
5.85
ag of VOC emission per kg of fluorocarbon produced; determined from refs 1 and 2.
bBased on the following 1978 production ratios: F-12/11, 60% F-22, 22%; F-113/114, 18%,
CExcluding fugitive and secondary emissions.
-------
V-4
The values indicate that, overall, the fluorocarbon processes are M9% con-
trolled with respect to VOC based on the production ratios given in Table V-l.
From the data in Table V-l and the 1979 total fluorocarbon production of 495 Gg,
the emissions from the fluorocarbon industry have been estimated to be 2.90 Gg
for 1979. This estimate does not include secondary, fugitive, or handling
emissions.
-------
V-5
B. REFERENCES*
1. David M. Pitts, IT Enviroscience, Inc., Trip Report on Site Visit to Allied Chemical
Corp., Morristown, NJ, Mar. 16, 1978 (on file at the EPA, ESED, Research Triangle
Park, NC).
2. Donald W. Smith, E. I. du Pont de Nemours & Company, letter dated Aug. 21, 1978,
regarding fluorocarbon manufacture in response to EPA's request for information
on emission data on fluorocarbon production facilities.
3. Donald W. Smith, E. I. du Pont de Nemours & Company, letter dated June 7, 1978,
regarding fluorocarbon process emissions at the Chambers Works, Corpus Christi,
Montague, and Antioch plants, in response to EPA's request for information on
emission data on fluorocarbon production facilities.
*When a reference number is used at the end of a paragraph or on a heading,
it usually refers to the entire paragraph or material under the heading.
When, however, an additional reference is required for only a certain portion
of the paragraph or captioned material, the earlier reference number may not
apply to that particular portion.
-------
APPENDIX A
Table A-l. Physical Properties of Fluorocarbon Compounds
Fluoroc urbon
Chemical
MoLecu]ar
Formula
Molecular
Welqht
Boiling Melting
Point Point
Liquid Solubility
Density in VJnter jt
(g/ml 25"C , 1 atn
at °C) (wt *..)
Vapor
Oil
F-12
r-22
F-113
F-114
Trichlorofluoromethnne CC1 F
Dichlorod if luorome thane CC1 F
Chlorodl fluoromethane CHC1F2
Trichlorofluorocthane C2C13F3
Pichlorotetra^luoroe thane C Cl F
137.
120.
06.
187,
170
30
,93
.48
.39
.94
23.8
-29.8
-40.8
47.6
3.8
-111
-158
-160
-35
-94
1.
1.
1,
1,
1
476/25
,311/25
.194/25
.565/25
.456/25
0.
0.
0.
0,
0
11
028
,30
.017
.013
1 a t n
23.7
5 atm
K>.l
in atn
24"C
it
"C
Jt
"<.:
at
400 nn Ho at
30.2°CC-
? .it-
^
'V C. Downing, 'Tluorinatpd Hydrocarbons," pp. 744, 745 in j
-------
B-l
Appendix B
Table B-l. Existing Industrial Emission Control Devices
Prodi
Emission Source
Control Device
Allied Chemical Corp.
Du Pont
See ref 1.
Distillation vents (2)
Storage vents
Distillation vents (2)
Storage vents
(I) Refrigerated vent
condenser and
scrubber
(2) Product recycle
None
(1) Refrigerated
vent condenser
(2) By-product (F-23)
recovery
Refrigerated vent
condenser
See ref 2.
-------
4-i
REPORT 4
1,1,1-TRICHLOROETHANE
AND
PERCHLOROETHYLENE, TRICHLOROETHYLENE, AND VINYLIDENE CHLORIDE (ABBREVIATED REPORT)
R. L. Standifer
J. A. Key
IT Enviroscience
9041 Executive Park Drive
Knoxville, Tennessee 37923
Prepared for
Emission Standards and Engineering Division
Office of Air Quality Planning and Standards
ENVIRONMENTAL PROTECTION AGENCY
Research Triangle Park, North Carolina
October 1980
This report contains certain information which has been extracted from the
Chemical Economics Handbook, Stanford Research Institute. Wherever used, it
has been so noted. The proprietary data rights which reside with Stanford
Research Institute must be recognized with any use of this material.
D121E
-------
CONTENTS OF REPORT 4
Page
I. ABBREVIATIONS AND CONVERSION FACTORS 1-1
II. INDUSTRY DESCRIPTION U-l
A. Introduction II-l
B. Usage and Growth II-3
C. Domestic Producers II-5
D. References 11-10
III. PROCESS DESCRIPTIONS III-l
A. Introduction III-l
B. 1,1,1-Trichloroethane III-l
C. Perchloroethylene and Trichloroethylene III-8
D. Vinylidene Chloride 111-15
E. References 111-18
IV. EMISSIONS IV-1
A. Introduction IV-1
B. 1,1,1-Trichloroethane IV-1
C. Perchloroethylene and Trichloroethylene IV-11
D. Vinylidene Chloride IV-15
E. References IV-21
V. APPLICABLE CONTROL SYSTEMS V-l
A. 1,1,1-Trichloroethane V-l
B. Perchloroethylene and Trichloroethylene V-5
C. Vinylidene Chloride V-5
D. References V-8
VI. IMPACT ANALYSIS VI-1
A. 1,1,1-Trichloroethane VI-1
B. Perchloroethylene and Trichloroethylene VI-5
C. Vinylidene Chloride VI-7
D. References VI-8
VII. SUMMARY VII-1
A. 1,1,1-Trichloroethane VII-1
B. References VII-4
-------
4-v
APPENDICES OF REPORT 4
Page
A. PHYSICAL PROPERTIES OF 1,1,1-TRICHLOROETHANE, PERCHLOROETHYLENE A-l
TRICHLOROETHYLENE, AND VINYLIDENE CHLORIDE
B. AIR-DISPERSION PARAMETERS B-l
C. FUGITIVE-EMISSION FACTORS C-l
D. EXISTING PLANT CONSIDERATIONS D-l
-------
4-vii
TABLES OF REPORT 4
Usage and Growth of 1,1,1-Trichloroethane, Perchloroethylene, II-4
Trichloroethylene, and Vinylidene Chloride
II-2 Production Capacity for 1,1,1-Trichloroethane, Perchloro- II-6
ethylene, Trichloroethylene, and Vinylidene Chloride
IV-1 Estimates of Total Uncontrolled VOC Emissions from a Model IV-2
Plant Producing 1,1,1-Trichloroethane from Vinyl Chloride
(136,000 Mg/yr)
IV-2 Estimated Composition of Distillation Vent Gas from Model IV-4
Plant Producing 1,1,1-Trichloroethane from Vinyl Chloride
IV-3 Storage Tank Data for 1,1,1-Trichloroethane (Vinyl Chloride IV-5
Feed) Model Plant
IV-4 Estimates of Total Uncontrolled VOC Emissions from a Model IV-7
Plant Producing 1,1,1-Trichloroethane from Ethane (29,500 Mg/yr)
IV-5 Estimated Composition of Distillation Vent Gas from Model IV-8
Plant Producing 1,1,1-Trichloroethane from Ethane
IV-6 Storage Tank Data for 1,1,1-Trichloroethane (Ethane Feed) IV-10
Model Plant
IV-7 Estimates of Uncontrolled Process VOC Emissions from Processes IV-12
Producing Perchloroethylene, Trichloroethylene, and Vinylidene
Chloride
IV-8 Estimated Composition of Neutralization and Drying Vent Gas from IV-13
a Perchloroethylene Plant
IV-9 Estimated Composition of Distillation Vent Gas from a IV-14
Perchloroethylene Plant
IV-10 Estimated Composition of Reactor Vent Gas from an Oxychlorination IV-16
Plant for Perchloroethylene and Trichloroethylene
IV-11 Estimated Composition of Drying Column Vent Gas from an IV-17
Oxychlorination Plant for Perchloroethylene and
Trichloroethylene
IV-12 Estimated Composition of Distillation Vent Gas from an IV-18
Oxychlorination Plant for Perchloroethylene and
Trichloroethylene
IV-13 Estimated Composition of Vent Gas from Reactor Section of a IV-19
Vinylidene Chloride Plant
IV-14 Estimated Composition of Distillation Vent Gas from a IV-20
Vinylidene Chloride Plant
V-l Estimates of Controlled VOC Emissions from a Model Plant V-2
Producing 1,1,1-Trichloroethane from Vinyl Chloride (136,000 Mg/yr)
V-2 Estimates of Controlled VOC Emissions from a Model Plant V-4
Producing 1,1,1-Trichloroethane from Ethane (29,500 Mg/yr)
-------
4-ix
TABLES (Continued)
Number
Page
V-3 Estimates of Controlled Process VOC Emissions from Processes V-6
Producing Perchloroethylene, Trichloroethylene, and Vinylidene
Chloride
V-4 Estimates of Controlled VOC Emissions from a Vinylidene Chloride V-7
Process
VI-1 Environmental Impact of Controlled Model Plant Producing VI-2
1,1,1-Trichloroethane from Vinyl Chloride
VI-2 Environmental Impact of Controlled Model Plant Producing VI-4
1,1,1-Trichloroethane from Ethane
VI-3 Estimate of Current Industry Emissions from Processes Producing VI-6
Perchloroethylene, Trichloroethylene, and Vinylidene Chloride
VII-1 Emission Summary for 1,1,1-Trichloroethane Model Plant, VII-2
Vinyl Chloride Process (136,000 Mg/yr)
VII-2 Emission Summary for 1,1,1-Trichloroethane Model Plant, VII-3
Ethane Process (29,500 Mg/yr)
A-l Properties of 1,1,1-Trichloroethane A-l
A-2 Properties of Perchloroethylene $-2
A-3 Properties of Trichloroethylene A-3
A-4 Properties of Vinylidene Chloride A-4
B-l Air-Dispersion Parameters for 1,1,1-Trichloroethane B-l
(Vinyl Chloride Feed) Model Plant with a Capacity of 136,000 Mg/yr
B-2 Air-Dispersion Parameters for 1,1,1-Trichloroethane B-2
(Ethane Feed) Model Plant with a Capacity of 29,500 Mg/yr
D-l Emission Control Devices or Techniques Currently Used by D-2
Producers of 1,1,1-Trichloroethane, Perchloroethane,
Trichloroethylene, Vinylidene Chloride
-------
4-xi
FIGURES OF REPORT 4
Number Page
II-l Processes for Production of 1,1,1-Trichloroethane, II-2
Perchloroethylene, Trichloroethylene, and Vinylidene
Chloride
II-2 Locations of Plants Manufacturing 1,1,1-Trichloroethane, II-7
Perchloroethylene, Trichloroethylene, and Vinylidene Chloride
III-l Flow Diagram for 1,1,1-Trichloroethane from Vinyl Chloride III-3
III-2 Flow Diagram for 1,1,1-Trichloroethane from Ethane III-6
III-3 Flow Diagram for Perchloroethylene and Trichloroethylene 111-10
by Chlorination
III-4 Flow Diagram for Perchloroethylene and Trichloroethylene 111-13
by Oxychlorination
III-5 Flow Diagram for Vinylidene Chloride from 1,1,2-Trichloroethane 111-16
-------
1-1
ABBREVIATIONS AND CONVERSION FACTORS
EPA policy is to express all measurements used in agency documents in metric
units. Listed below are the International System of Units (SI) abbreviations
and conversion factors for this report.
To Convert From
Pascal (Pa)
Joule (J)
Degree Celsius (°C)
Meter (m)
Cubic meter (m3)
Cubic meter (m3)
Cubic meter (m3)
Cubic meter/second
(m3/s)
Watt (W)
Meter (m)
Pascal (Pa)
Kilogram (kg)
Joule (J)
To
Atmosphere (760 mm Hg)
British thermal unit (Btu)
Degree Fahrenheit (°F)
Feet (ft)
Cubic feet (ft3)
Barrel (oil) (bbl)
Gallon (U.S. liquid) (gal)
Gallon (U.S. liquid)/min
(gpm)
Horsepower (electric) (hp)
Inch (in.)
Pound-force/inch2 (psi)
Pound-mass (Ib)
Watt-hour (Wh)
Standard Conditions
68°F = 20°C
1 atmosphere = 101,325 Pascals
PREFIXES
Multiply By
9.870 X 10"6
9.480 X 10~4
(°C X 9/5) + 32
3.28
3.531 X 101
6.290
2.643 X 102
1.585 X 104
1.340 X 10"3
3.937 X IO1
1.450 X 10"4
2.205
2.778 X 10"4
Prefix
T
G
M
k
m
M
Symbol
tera
giga
mega
kilo
milli
micro
Multiplication
Factor
10
12
109
106
103
io"3
io"6
Example
1 Tg = 1 X IO12 grams
1 Gg = 1 X IO9 grams
1 Mg = 1 X IO6 grams
1 km = 1 X IO3 meters
1 mV = 1 X IO"3 volt
1 pg = 1 X IO"6 gram
-------
II-l
II. INDUSTRY DESCRIPTION
A. INTRODUCTION
1,1,1-Trichloroethane (also called methyl chloroform), perchloroethylene, trichloro-
ethylene, and vinylidene chloride are produced as co-products or are produced
individually by several processes (see Fig. II-l). The starting raw materials
are primarily chlorine and ethylene dichloride, although the flexibility of some
of the processes allows other C2 chlorinated hydrocarbons or waste streams to
be used when available. Hydrogen chloride is generated as a by-product from
many of the processes and used as a raw material in others. It is also a raw
material for the oxychlorination process for producing ethylene dichloride. In
order to optimize production economics the hydrogen chloride—generating processes
and the hydrogen chloride—consuming processes are usually integrated in a complex
where the product or the unwanted by-products and waste streams from one process
are utilized as part or all of the raw materials for another process.1'2
This report discusses the emissions and control options for the processes for
production of 1,1,1-trichloroethane from vinyl chloride and from ethane. Also
covered, in abbreviated form, are the chlorination and oxychlorination processes
for producing perchloroethylene and trichloroethylene as co-products and the
process for production of vinylidene chloride from 1,1,2-trichloroethane. The
process for producing 1,1,1-trichloroethane from vinylidene chloride reportedly
is on standby.1 Although the uncontrolled emissions from the processes producing
perchloroethylene and trichloroethylene are estimated to be large, they are
controlled to a reasonable degree in existing production facilities, and little
or no growth is projected for perchloroethylene and trichloroethylene production.
A previous product report3 covered the chlorinolysis of hydrocarbons (and their
partially chlorinated derivatives) at or close to pyrolytic conditions to produce
perchloroethylene and carbon tetrachloride as co-products. The production of
ethylene dichloride is covered in another product report,4 and the pyrolysis of
ethylene dichloride to vinyl chloride is described in several EPA documents.5'6
Perchloroethylene and trichloroethylene have been produced in the past by chlori-
nation of acetylene but the high cost of acetylene has caused all domestic plants
to be shut down, the last one in 1978.1
-------
MAY AUSO
CHLoe,0& UAY AUSO BE USHO A5
(?) PREVIOUS
©
AS EAW MAT«,AU.
Fig II-l. Processes for Production of 1,1,1-Trichloroethane, Perchloroethylene,
Trichloroethylene, and Vinylidene Chloride
-------
II-3
1,1,1-Trichloroethane production was selected for study because preliminary
estimates indicated relatively high total emissions of volatile organic compounds
(VOC), because it was suspected that it causes harmful health effects,7 and because
substantial industry growth was projected. Perchloroethylene and trichloroethylene
are included because they are also chlorinated solvents used in metal cleaning
and are often produced in the same complex with 1,1,1-trichloroethane. Vinylidene
chloride was included because, as a chlorinated C2 compound, the production
processes, emissions, and associated controls are similar to those for the C2
chlorinated solvents.
1,1,1-Trichloroethane, perchloroethylene, trichloroethylene, and vinylidene
chloride are liquids under ambient conditions but are sufficiently volatile for
gaseous emissions to occur during production (see Appendix A for pertinent pro-
perties). The emissions from their production consist of ethylene dichloride,
1,1,1-trichloroethane, perchloroethylene, trichloroethylene, vinyl chloride,
vinylidene chloride, and other chlorinated hydrocarbons.
B. USAGE AND GROWTH1'2
Table II-l shows the end uses of 1,1,1-trichloroethane, perchloroethylene, tri-
chloroethylene, and vinylidene chloride and their expected growth rates. The
predominant use of both 1,1,1-trichloroethane and trichloroethylene is as a
metal-cleaning solvent. Although trichloroethylene is the preferred solvent
for this application, its use has declined since it was found to contribute to
smog formation and to be carcinogenic to mice and possibly also to humans.
Perchloroethylene is also used as a metal-cleaning solvent but its major use is
as a dry-cleaning and textile-processing solvent. Vinylidene chloride is con-
sumed largely in the production of polyvinylidene copolymers such as Saran® and
some modacrylic fibers. Until recently it was also used as a raw material for
the production of 1,1,1-trichloroethane. Perchloroethylene and 1,1,1-trichloro-
ethane are used as raw materials for various chemicals. 1,1,1-Trichloroethane
is also used in aerosol propellant formulations, as a solvent in adhesive and
coatings formulations, as a drain cleaner, and as a fabric spotting fluid and
in many other applications. Trichloroethylene is used as an extractive solvent
and as a component of certain drugs.
-------
Table II-l. Usage and Growth of 1,1,1-Trichloroethane, Perchloroethylene, Trichloroethylene, and
Vinylidene Chloride*
End Use
Metal cleaning
Dry cleaning and
textile processing
Chemical intermediate
Miscellaneous
*See refs 1 and 2.
1,1, 1-Trichloroethane
Consumption Average Growth
for 1977 for 1977-1982
(%) (%/yr)
67 6
2 8
31 7
Perchloroe thy lene
Consumption
for 1977
(%)
16
59
13
12
Average Growth
for 1977-1982
(%/yr)
1
-1.5
5
-1.5
Trichloroethylene Vinylidene Chloride
Consumption Average Growth Consumption Average Growth
for 1977 for 1977-1982 for 1977 for 1977-1982
(%) (Vyr) (%) (%/yr)
83 0
100 6
17 -5
H
H
1
-------
II-5
The increases in the consumption of 1,1,1-trichloroethane, perchloroethylene,
trichloroethylene, and vinylidene chloride are difficult to predict because all
of them are under pressure from governmental organizations charged with main-
taining environmental quality and with protecting the workers' health. Because
of the uncertainties concerning future regulations, future uses could be con-
siderably different from projections. 1,1,1-Trichloroethane has experienced
strong growth as a substitute for trichloroethylene, because trichloroethylene
was believed to be a contributor to smog formation and 1,1,1-trichloroethane
was believed not to be. Recently, some researchers have claimed that 1,1,1-tri-
chloroe thane in the stratosphere can damage the ozone layer, although there is
controversy over the validity of these conclusions.1 Perchloroethylene has been
under the same restrictions as any other organic solvent as to the amount emitted in
operations involving heating in the presence of oxygen or where it comes in contact
with a flame.1 Now perchloroethylene,1 trichloroethylene,1 and vinylidene chloride2
are under suspicion as carcinogens, although the validity of this finding for
perchloroethylene has been challenged.
The domestic production capacity of 1,1,1-trichloroethane in 1977 was estimated
to be 313,000 Mg, with approximately 92% of this capacity being utilized. However,
since by the end of 1979 the capacity is expected to be about 590,000 Mg/yr,
considerable excess capacity will exist in 1982, even with an increase in demand
of 5% per year, unless older capacity is shut down. In 1977 perchloroethylene
production utilized only about 56% of an estimated capacity of 542,000 Mg, and
trichloroethylene production was only about 60% of an estimated capacity of
225,000 Mg. With perchloroethylene expected to show no growth in demand and
with trichloroethylene demand expected to drop about 3% per year, there will be
considerable excess capacity for both in 1982. Some plants have been shut down
or placed on standby. Vinylidene chloride demand is expected to grow about 6%
per year. Data are not available on industry vinylidene chloride capacity but
the capacity is believed to be adequate to meet demand through 1982. The 1978
production of vinylidene chloride was 81,000 Mg.
C. DOMESTIC PRODUCERS
Table II-2 lists the producers, locations, and capacities of plants producing
1,1,1-trichloroethane, perchloroethylene, trichloroethylene, and vinylidene
chloride as of January 1, 1979. Figure II-2 shows the plant locations.2'8'9
-------
Table II-2. Production Capacity for 1,1,1-Trichloroethane,
Perchloroethylene, Trichloroethylene, and Vinylidene Chloride
Company
Diamond Shamrock
Dow
Du Pont
Ethyl
PPG
Stauffer
Vulcan
Total
Location
Deer Park, TX
Freeport, TX
Pittsburg, CA
Plaquemine, LA
Corpus Christ! , TX
Baton Rouge , LA
Lake Charles , LA
Louisville, KY
Geismar, LA
Wichita, KS
1979 Capacity
1,1, 1-Trichloroethane Perchloroethylene3
75,000
204,000 68,000
18,000
136,000 54,000
73,000
23,000
159,000 91,000
32,000
90,000 68,000
23,000
589,000 525,000
(Mg/yr)
Trichloroethylene Vinylidene Chloride
b
68,000 c
23,000 — 45,000
20,000
91,000 88,000d
179,000 c
H
See ref 2.
23,000-Mg/yr capacity unit placed on standby in early 1978 (ref 2).
Capacity data not available.
d
Includes 23,000-Mg/yr expansion completed in 1978 (ref 9). Most of this capacity (88,000 Mg/yr) was placed on stand-by with the shutdown
of PPG's vinylidene chloride—based 1,1,1-trichloroethane process.
-------
Chemicals
Produced*
(1) Diamond Shamrock Corp., Deer Park, TX
(2) Dow Chemical Co., Freeport, TX
(3) Dow Chemical Co., Pittsburg, CA
(4) Dow Chemical Co., Plaquemine, LA
(5) Du Pont, Corpus Christi, TX
(6) Ethyl Corp., Baton Rouge, LA
(7) PPG Industries, Inc., Lake Charles, LA
(8) Stauffer Chemical Co., Louisville, KY
(9) Vulcan Materials Co., Geismar, LA
[10) Vulcan Materials Co., Wichita, KS
B
A-D
B
A,B,D
B
B,C
A-D
B
A,B
B
*A = 1,1,1-trichloroethane; B = perchloroethylene; C
D = vinylidene chloride.
= trichloroethylene;
Fig. II-2. Locations of Plants Manufacturing 1,1,1-Trichloroethane,
Perchloroethylene, Trichloroethylene, and Vinylidene Chloride
-------
II-8
Perchloroethylene is produced at all ten locations by each of the seven producers;
however, seven of the plants use the mixed hydrocarbon chlorinolysis process to
produce perchloroethylene, with carbon tetrachloride produced as a co-product.
That process is discussed in a previous report.3
The companies producing one or more of the four products involved are as
follows:
1. Diamond Shamrock Corp. Chlorinates ethylene dichloride to produce perchloro-
ethylene. Their trichloroethylene production was placed on standby in early
1978; the capacity was 23,000 Mg/yr.2
2. Dow Chemical Co. Produces 1,1,1-trichloroethane from vinyl chloride and produces
vinylidene chloride starting with ethylene dichloride at Freeport, TX, and Plaquemi
LA.2 Perchloroethylene is produced at Pittsburg, CA, Freeport, TX, and Plaquemine,
LA, by the chlorinolysis process, with carbon tetrachloride produced as a by-produc
Trichloroethylene is produced by chlorination of ethylene dichloride at Freeport,
TX.2
3. Du Pont Produces perchloroethylene by chlorinolysis of light hydrocarbons,
with carbon tetrachloride produced as a co-product. All perchloroethylene output
is used in the manufacture of fluorocarbons.2
4. Ethyl Corp. Produces perchloroethylene and trichloroethylene by chlorination
of ethylene dichloride.2
5. PPG Industries Produces perchloroethylene and trichloroethylene by oxychlori-
nation of ethylene dichloride; chlorinates ethylene dichloride to 1,1,2-tri-
chloroethane, which is dehydrochlorinated to vinylidene chloride. 1,1,1-Tri-
chloroethane is produced by hydrochlorination of vinyl chloride to 1,1-dichloro-
ethane, followed by chlorination. 1,1,1-Trichloroethane was previously produced
from vinylidene chloride. The vinylidene chloride—based process was reportedly
placed on standby with the startup of the new vinyl chloride—based process in
1979.i'2'io
-------
II-9
6. Stauffer Chemical Co. Produces perchloroethylene and carbon tetrachloride by
chlorinolysis of chlorination bottoms.1
7. Vulcan Materials Co. Produces perchloroethylene by chlorinolysis of chlorina-
tion bottoms and ethylene dichloride, with carbon tetrachloride produced as a
co-product at Geismar, LA, and Wichita, KS. 1,1,1-Trichloroethane is produced
by chlorination of ethane at Geismar, LA.1
-------
11-10
D. REFERENCES*
1. S. A. Cogswell, "C2 Chlorinated Solvents," pp. 632.3000A—F and 632.3001A—
632.3002A in Chemical Economics Handbook, Stanford Research Institute, Menlo
Park, CA (December .1978).
2. S. A. Cogswell, "Ethylene Dichloride," pp. 651.5031A—F and 651.5032A—651.50331
in Chemical Economics Handbook, Stanford Research Institute, Menlo Park, CA
(February 1979).
3. F. D. Hobbs and C. W. Stuewe, IT Enviroscience, Inc., Carbon Tetrachloride and
Perchloroethylene (Hydrocarbon Chlorinolysis Process) (in preparation for EPA,
ESED, Research Triangle Park, NC).
4. F. D. Hobbs and J. A. Key, IT Enviroscience, Inc., Ethylene Dichloride (in
preparation for EPA, ESED, Research Triangle Park, NC).
5. R. G. Bellamy and W. A. Schwartz, Houdry Div., Air Products and Chemicals,
Engineering and Cost Study of Air Pollution Control for the Petrochemical
Industry. Volume 8: Vinyl Chloride Manufacture by the Balanced Process,
EPA-450/3-7-006-h, Research Triangle Park, NC (July 1975).
6. D. R. Goodwin, Standard Support and Environmental Impact Statement: Emission
Standard for Vinyl Chloride, EPA-450/2-75-009, Research Triangle Park, NC
(October 1975).
7. "Cancer Warning on Chloroethanes," Chemical Week 123(10), 21 (Sept. 6, 1978).
8. Arthur D. Little, Inc., Final Report. Vinylidene Chloride Monomer Emissions from
the Monomer, Polymer, and Polymer Processing Industries, ADR-76086-31, prepared
for EPA Control Systems Laboratory, Durham, NC (April 1976).
9. "Vinylidene Chloride Monomer," p. 80 in 1978 Directory of Chemical Producers,
United States of America, Supplement 1, Stanford Research Institute, Menlo Park,
CA.
10. F. C. Dehn, PPG Industries, Inc., letter dated Mar. 14, 1979, to EPA in response
to request for information on the air emissions from the 1,1,1-trichloroethane,
perchloroethylene, and trichloroethylene processes at Lake Charles, LA.
*Usually, when a reference is located at the end of a paragraph, it refers to
the entire paragraph. If another reference relates to certain portions of
that paragraph, that reference number is indicated on the material involved.
When the reference appears on a heading, it refers to all the text covered by
that heading.
-------
III-l
III. PROCESS DESCRIPTIONS
A. INTRODUCTION
In this section the processes for producing 1,1,1-trichloroe thane from vinyl chlor-
ide and from ethane, the chlorination and oxychlorination processes for the produc-
tion of perchloroethylene and trichloroethylene, and the caustic dehydrochlorination
process for production of vinylidene chloride are described. The process for
production of 1,1,1-trichloroethane from vinylidene chloride reportedly is on
standby1 and is not described.
B. 1,1,1-TRICHLOROETHANE
1. Introduction
Most of the 1,1 ,1-trichloroethane produced domestically is made by the vinyl
chloride process, with minor amounts made by the ethane process.1 — 4 Vinyl
chloride, which is produced from ethylene dichloride, is first hydrochlorinated
with hydrogen chloride to 1,1-dichloroethane, which is then thermally chlorinated
to produce 1,1,1-trichloroethane. The yields from vinyl chloride are over 95%. 5
With ethane and chlorine as raw materials, 1,1,1-trichloroethane is produced by
the noncatalytic chlorination of ethane. Ethyl chloride, vinyl chloride, vinyli-
dene chloride, and 1,1-dichloroethane are also produced, with the relative quanti-
ties of the various product fractions being somewhat dependent on operating con-
ditions. When 1,1,1-trichloroethane is the only desired product, vinyl chloride
and vinylidene chloride are hydrochlorinated to 1,1-dichloroethane and 1,1,1-tri-
chloroethane respectively, and ethyl chloride and 1,1-dichloroethane are recycled
to the chlorination step.5
2. Vinyl Chloride Process
Starting with vinyl chloride the following reactions are required to produce
1,1,1-trichloroethane: the hydrochlorination of vinyl chloride to 1,1-dichloro-
ethane and the chlorination of 1,1-dichloroethane to 1,1,1-trichloroethane. The
hydrochlorination of vinyl chloride to 1,1-dichloroethane takes place according
to the following reaction:
CH2=CHC1 + HC1 3 ^ CH3-CHC12
(vinyl chloride) (hydrogen chloride) (1,1-dichloroethane)
-------
III-2
The chlorination of 1,1-dichloroethane to 1,1,1-trichloroethane takes place
according to the following reaction:
CH3-CHC12 + C12 > CH3-CC13 + HC1
(1,1-dichloroethane) (chlorine) (1,1,1-trichloroethane) (hydrogen chloride
Figure III-l represents a flow diagram for a process in which 1,1,1-trichloro-
ethane is produced from vinyl chloride.5'6 Vinyl chloride (stream 1) from storage,
hydrogen chloride (stream 2), and the recycled overhead stream (7) from the
light-ends column are fed to the hydrochlorination reactor. The reaction is
exothermic and takes place at 35 to 40°C in the presence of a catalytic amount
of ferric chloride.
Ammonia (stream 4) is added to the reactor effluent (stream 3), forming a solid
complex with the residual hydrogen chloride and the ferric chloride catalyst.
The complex is removed by the spent catalyst filter as a semisolid waste stream
(source G). The filtered hydrocarbon stream (stream 5) passes to the heavy-ends
column, where high-boiling chlorinated organics (tars) are removed as a waste
stream (source H) from the bottom.
The overhead (stream 6) passes to the light-ends column, where a separation is
made between 1,1-dichloroethane and the lighter components, primarily unreacted
vinyl chloride. The overhead stream (7) is recycled to the hydrochlorination
reactor. The 1,1-dichloroethane product is removed as the bottom stream (8)
and transferred to intermediate storage.
1,1-Dichloroethane from intermediate storage and chlorine (stream 9) are combined
and fed to the chlorination reactor, where the 1,1-dichloroethane is converted
to 1,1,1-trichloroethane. The reaction is exothermic and noncatalytic, occurring
at a temperature of about 400°C. The reactor effluent (stream 10) passes to
the hydrogen chloride column, where the hydrogen chloride formed in the reaction
and some low-boiling organic compounds are removed overhead (stream 11). This
stream may be used to supply the hydrogen chloride requirements of other chlorinate
organic processes directly (e.g., the ethylene dichloride process) or it may be
purified to remove the contained organics before it is used.
-------
MCI
VIUVL
FUGITIVE.
CATALYS
ST^
HCI
COLUMKJ
HEAVY
COI-UMU
CATAL.VST
FILTER-
EMDS
CO-UK/VJ
1.1,1-
TEJCHLOR.O-
ETHAWE.
COLUMU
©
DO
©
I
Ul
ER.
Fig..III-l. Flow Diagram for 1,1,1-Trichloroethane from Vinyl Chloride
-------
III-4
The bottom stream (12) from the hydrogen chloride column passes to the 1,1,1-tri-
chloroethane column. The purified product is removed overhead (stream 13) and,
after the addition of a stabilizer, is transferred to storage. The bottom stream
(14) from the 1,1,1-trichloroethane column, composed primarily of 1,1,2-trichloro-
ethane, is transferred as feed to other chlorinated organic processes (e.g.,
perchloroethylene-trichloroethylene).
The distillation column vents (A), which release primarily noncondensable gases,
are sources of process emissions. Storage emissions (vents B and C) include
emissions from intermediate storage of 1,1-dichloroethane and from 1,1,1-tri-
chloroethane product storage. Handling emissions (source D) result from the
loading of 1,1,1-trichloroethane into tank trucks or tank cars for shipment.
Fugitive emissions (E) occur when leaks develop in valves or compressor seals.
When process pressures are higher than the cooling-water pressure, VOC can leak
into the cooling water and escape as a fugitive emission from the cooling towers.
Secondary emissions can occur when wastewater from miscellaneous process sources
(source F) is sent to a wastewater treatment system and the contained VOC are
desorbed. Other sources of secondary emissions are from the disposal of catalyst
residue (source G) in landfill and from the combustion of organic wastes (source H)
(Secondary emissions occur when VOC are emitted with the combustion flue gas.)
3. Ethane Process
When chlorine is reacted with ethane, the main sequence of reactions occurring
can be summarized as follows:5
CH3-CH3
(ethane)
+C1,
+C1.
-HC1
(ethyl chloride)
-HC1
CH2=CH2
(ethylene)
(1,1-dichloro-
ethane)
-HC1
CH2=CHC1
(vinyl chloride)
CH3CC13
(1,1,1-tri-
chloroethane)
-HC1
CH2=CC12
(vinylidene chloride)
Minor quantities of 1,2-dichloroethane and 1,1,2-trichloroethane are also produced.
The product mix attained can be varied somewhat through changes in operating con-
ditions. When 1,1,1-trichloroethane is the only desired product, the ethyl chloric
-------
III-5
and 1,1-dichloroethane produced are recycled to the chlorination reactor, and the
vinyl chloride and vinylidene chloride are catalytically hydrochlorinated to
1,1-dichloroethane and 1 ,1 ,1-trichloroethane respectively, as represented by
the following reactions:
CH2=CHC1 + HC1 eS > CH3-CHC12
(vinyl chloride) (1,1-dichloroethane)
CH2=CC12 + HC1 *e^a > CH3-CC13
(vinylidene chloride) (1,1,1-trichloroethane)
Figure III-2 represents a flow diagram for an ethane chlorination process.5'6
For startup, ethane is circulated through the chlorination reactor and through
a fuel-fired furnace (not shown) to bring the reactor temperature to about 350°C
before normal feed flows are established. Chlorine (stream 1) and ethane (stream 2)
supplied by pipeline are then fed to the reactor. The approximate chlorination
reaction conditions are a temperature of 400°C and a pressure of 600 kPa. The
reactor is operated adiabatically with a residence time of about 15 sec. A
catalyst is not required for the chlorination reaction. When recycle flows are
established, the 1,1-dichloroethane and ethyl chloride formed in the process
(12 and 19) are also introduced as chlorination reactor feed.
The exit stream (3) from the reactor contains ethane, ethylene, vinyl chloride,
ethyl chloride, vinylidene chloride, 1,1-dichloroethane, 1,2-dichloroethane,
1,1,2-trichloroethane, 1,1,1-trichloroethane, a small amount of other chlori-
nated hydrocarbons, and hydrogen chloride.
The reactor effluent gas (stream 3) enters the quench column, where it is cooled
and a residue stream consisting primarily of tetrachloroethane and hexachloroethane
is removed (source H).
The overhead stream (4) from the quench column enters the hydrogen chloride
column for separation of ethane, ethylene, and hydrogen chloride from the chlori-
nated hydrocarbons. A part of the hydrogen chloride column overhead stream (5)
supplies the hydrogen chloride requirements of the hydrochlorination reactor.
The excess hydrogen chloride and the contained ethane and ethylene (stream 6)
pass to a hydrogen chloride purification step (not shown), eventually providing
hydrogen chloride for other processes.
-------
.©
TD HCI
P-AMT
ETHAVJE
03CUK/.U
HO
CO-OMKJ
FR.CM
»,'~
D\CHI_oeO-
PRODUCT
REODVE.2.Y
COLUMM
HEAVY
euo^
COU.UMU
1,1,1-TRI-
CHLOKOETHAUE
COUUMM
®,
TO
1, \-DlcHl_ORjD-
COt-UMU
>4V D£O CLOE. I -
PPCDOCT
Escovtva
COUJMV-l
Fig. III-2. Flow Diagram for 1,1,1-Trichloroethane from Ethane
-------
III-7
The hydrogen chloride—free chlorinated hydrocarbons (stream 7) from the hydrogen
chloride column pass to the heavy-ends column, where the higher boiling components
(primarily 1,2-dichloroethane and 1,1,2-trichloroethane) are removed as a bottoms
stream (8) and are transferred as feed to other chlorinated hydrocarbon processes
(e.g., perchloroethylene). The overhead stream (9), composed primarily of
1,1,1-trichloroethane, vinyl chloride, vinylidene chloride, ethyl chloride, and
1,1-dichloroethane, is combined with the bottoms stream (18) from the product
recovery column and fed to the 1,1,1-trichloroethane column. Refined 1,1,1-tri-
chloroethane is removed as the bottoms stream (10). After a stabilizer is added,
the 1,1,1-trichloroethane is transferred to product storage.
The overhead stream (11) from the 1,1,1-trichloroethane column is fed to the
1,1-dichloroethane column, where 1,1-dichloroethane is separated as the bottoms
stream (12) and is recycled as feed to the chlorination reactor. The overhead
stream (13), composed of vinyl chloride, vinylidene chloride, and ethyl chloride,
is fed to the hydrochlorination reactor, where vinyl chloride is converted to
1,1-dichloroethane and vinylidene chloride is converted to 1,1,1-trichloroethane.
Hydrogen chloride requirements are supplied by a part of the hydrogen chloride
column overhead stream (stream 5). Hydrochlorination reactor conditions include
a temperature of 65°C, a pressure 450 kPa, and a catalytic amount of ferric
chloride (stream 14).
Ammonia (stream 16) is added to the reactor effluent stream (stream 15) and
reacts with the residual hydrogen chloride and ferric chloride to form a solid
ammonium chloride—ferric chloride—ammonia complex. The solid complex is removed
by the spent catalyst filter as a semisolid waste stream (source G). The filtered
hydrocarbon stream (17) passes to the product recovery column, where a rough
separation of 1,1,1-trichloroethane from the 1,1-dichloroethane—ethyl chloride
fraction is made. The bottoms fraction (stream 18), composed primarily of
1,1,1-trichloroethane, is recycled to the 1,1,1-trichloroethane column. The
overhead stream (19), consisting primarily of ethyl chloride and 1,1-dichloroethane,
is recycled to the chlorination reactor.
The distillation column vents (A), which release primarily noncondensable gases,
are the only significant source of process emissions. Storage emission sources
(vents B and C) include intermediate storage and product storage. Handling emis-
sions (vent D) result from the loading of 1,1,1-trichloroethane into tank cars
and tank trucks.
-------
III-8
Fugitive emissions (E) occur when leaks develop in valves or in pump seals.
When process pressures are higher than the cooling-water pressure, VOC can leak
into the cooling water and escape as a fugitive emission from the cooling towers.
Secondary emissions can occur when wastewater from miscellaneous process sources
(source F) is sent to a wastewater treatment system and the contained VOC are
desorbed. Other sources of secondary emissions are from the disposal of catalyst
residue (source G) and from the combustion of liquid wastes (source H). (Secondary
emissions occur when VOC are emitted with the combustion flue gas.)
C. PERCHLOROETHYLENE AND TRICHLOROETHYLENE
1. Introduction
Perchloroethylene and trichloroethylene are produced separately or as co-products
by either chlorination or oxychlorination of ethylene dichloride or other C2
chlorinated hydrocarbons, with the raw-material ratios determining the proportions
of perchloroethylene and trichloroethylene.1 Of the domestic plants using the
chlorination process, one produces only perchloroethylene,7 a second produces
only trichloroethylene,8 and a third produces both perchloroethylene and tri-
chloroethylene as co-products.9 Perchloroethylene and trichloroethylene are
also produced as co-products by the one plant that uses the oxychlorination
process.3 Perchloroethylene and carbon tetrachloride are produced as co-products
by the chlorinolysis of hydrocarbons and their partially chlorinated derivatives.
This process produces more perchloroethylene than do the other processes combined
and is described in a previous product report.10
2. Chlorination
The main reactions for the chlorination of ethylene dichloride to perchloro-
ethylene and trichloroethylene are as follows:
C1CH2CH2C1 + 3 C12 ^ C12C=CC12 + 4HC1
(ethylene (chlorine) (perchloroethylene) (hydrogen chloride)
dichloride)
C1CH2CH2C1 + 2C12 > C12C=CHC1 + 3HC1
(ethylene (chlorine) (trichloroethylene) (hydrogen chloride)
dichloride)
-------
III-9
The chlorination is carried out at a high temperature (400 to 450°C), slightly
above atmospheric pressure, and without the use of a catalyst. Other chlorinated
C2 hydrocarbons or recycled chlorinated hydrocarbon by-products may be fed to
the chlorinator. The large quantity of hydrogen chloride produced is usually
used in other processes.1
The flow diagram shown in Fig. III-3 represents a process for chlorinating ethylene
dichloride and other C2 chlorinated organics to make perchloroethylene and tri-
chloroethylene. Ethylene dichloride (stream 1) and chlorine (stream 2) are fed
to the reactor and quench area, where they are first vaporized and then sent to
the reactor. Hydrogen chloride (stream 3) is separated from the chlorinated
hydrocarbon mixture (stream 4) produced in the reactor and sent to other processes.
The chlorinated hydrocarbon mixture (stream 4) is neutralized with sodium hydroxide
solution (stream 5), which leaves the system as wastewater (F) when spent, and
is then dried.7
The dried crude product (stream 7) is separated by the perchloroethylene/trichloro-
ethylene column into crude trichloroethylene (stream 8) and crude perchloroethylene
(stream 9). The crude trichloroethylene (stream 8) goes to the trichloroethylene
column, where the lights (stream 10) go overhead and the bottoms (stream 11),
containing trichloroethylene and heavies, are sent to the finishing column.
Trichloroethylene (stream 12) is taken overhead and sent to trichloroethylene
storage; the heavies (stream 13) are combined with the lights (stream 10) from
the trichloroethylene column and sent to the recycle organic storage.7'9
The crude perchloroethylene (stream 9) from the perchloroethylene/trichloroethylene
column is separated in the perchloroethylene column,- the perchloroethylene
(stream 14) goes overhead to perchloroethylene storage and the bottoms (stream 15)
go to the heavies column. There the heavies (stream 16) go overhead and are sent
to the recycle organic storage. The tars (G) are sent to an incinerator for
disposal.7—9
If any C2 chlorinated organics (stream 18) from other processes are fed to the
process, they may be combined with the recycled lights and heavies (streams 10,
13, and 16) and the combined recycle organics (stream 19) fed to the reactor
and quench area.7—9
-------
I
ui
O
H-
ft)
i-i
O
o
(D
rt
(D
(D
o
3
0)
rt
(D
3
cr
^<
n
rr
M
o
O
3
OT-III
-------
III-ll
The neutralization and drying area vent (A), which releases the inert gases from
the chlorine and ethylene dichloride feeds, and the distillation column vents (B),
which release primarily noncondensable gases, are sources of process emissions.
Storage emission sources (vents C) are raw-material storage, recycle storage, and
product storage. Handling emissions (vents D) can occur while perchloroethylene
and trichloroethylene are being loaded into drums, tank trucks, tank cars, barges,
or ships for shipment . 7 — 9
Fugitive emissions (E) occur when leaks develop in valves or in pump seals.
When process pressures are higher than the cooling-water pressure, VOC can leak
into the cooling water and escape as a fugitive emission from the cooling tower.
Secondary emissions can occur when wastewater containing VOC is sent to a waste-
water treatment system or lagoon and the VOC are desorbed (F). Another source
of secondary emissions is the combustion of tars in an incinerator where VOC
are emitted with the flue gases (G).7
3. Oxychlorination3'11'12
The main reactions for the oxychlorination of ethylene dichloride to perchloro-
ethylene and trichloroethylene are as follows:
C1CH2CH2C1 + C12 + 02 U* > C12C=CC12 + 2H20
(ethylene (chlorine) (oxygen) (perchloroethylene) (water)
dichloride)
4C1CH2CH2C1 + 2C12 + 02 * > 4C12C=CHC1 + 6H20
(ethylene (chlorine) (oxygen) (trichloroethylene) (water)
dichloride)
Hydrogen chloride and chlorinated organics may be fed to supply the chlorine,
either in combination with chlorine or separately. Side reactions produce carbon
dioxide, hydrogen chloride, and several chlorinated hydrocarbons. A fluid-bed
reactor containing a vertical bundle of tubes with boiling liquid outside the
tubes is used to control the reaction temperature at about 425°C. The reactor
is operated at pressures slightly above atmospheric, and the catalyst, which
contains copper chloride, is continuously added to the tube bundle as entrained
catalyst fines are carried away with the crude product. The crude product contains
85 to 90 wt % perchloroethylene plus trichloroethylene and 10 to 15 wt % by-product
-------
111-12
organics. Essentially all by-product organics are recovered during purification
and are recycled to the reactor. The process is very flexible, so that the
reaction can be directed toward the production of either perchloroethylene or
trichloroethylene in varying proportions.
The flow diagram shown in Fig. III-4 is based on information provided by PPG;3
data on this process are also given in the literature.11'12 Ethylene dichloride
(stream 1), chlorine or hydrogen chloride (stream 2), and oxygen (stream 3) are
fed to the fluid-bed reactor as gases.6 Catalyst fines generated by the fluidi-
zation of the catalyst in the reactor leave with the gaseous product (stream 4).
The reactor product is condensed in both a water-cooled condenser and a refrigerated
condenser; all the condensed material and the catalyst fines drain to a decanter.
The noncondensed inert gases (stream 5), consisting of carbon dioxide, hydrogen
chloride, nitrogen, and a small amount of uncondensed chlorinated hydrocarbons,
go to the hydrogen chloride absorber, where hydrogen chloride is recovered by
absorption in process water to make by-product hydrochloric acid and the remaining
inert gases are purged (vent A).
In the decanter the crude product (stream 7) is phase-separated from the aqueous
phase and catalyst fines (stream 8), which goes to waste treatment (H), and
then the crude product is sent to the drying column for removal of dissolved
water by azeotropic distillation. The water (stream 9) from the drying column
goes to waste treatment (H) and the dried crude product (stream 10) is separated
into crude trichloroethylene (stream 11) and crude perchloroethylene (stream 12)
in the perchloroethylene/trichloroethylene column.
The crude trichloroethylene (stream 11) is sent to the trichloroethylene column,
where the lights (stream 13) go overhead and are sent to the recycle organic
storage. The bottoms (stream 14) are neutralized with ammonia in the trichloro-
ethylene neutralizer and then dried in the trichloroethylene dryer to obtain
the finished trichloroethylene (stream 15) that is sent to the trichloroethylene
storage.
The crude perchloroethylene (stream 12) from the perchloroethylene/trichloroethylene
column goes to the heavies column, where perchloroethylene and lights (stream 16)
go overhead to the perchloroethylene column and the heavies (stream 17) remaining
-------
MAK.EUP
4®
A.OD
©
,© €
:HUDR\ ce
®
«>
AMD CATALYST
f=IWE.
wA.TE.2- ^-p
ET H V\_E KJ E
(JECYCUE
CK^AMIC
STcCASiS
CZ
TAfiS TO
HEAVY
EUOS
COUUMU
»© ©'
xj—
AQUEOUS
ETHYLEklE
COLUMM
PROCESS
ETHYLEUE
T
Fig
III-4- Flow Diagram for Perchloroethylene and Trichloroethylene by Oxychlorination
-------
111-14
as the bottoms are sent to the organic recycle system. Here the organics that
can be recycled (stream 18) are separated from the tars and sent to the recycle
organic storage. The tars are sent to an incinerator for disposal.
The perchloroethylene and lights (stream 16) from the heavies column go to the
perchloroethylene column, where the lights (stream 20) go overhead and are sent
to the recycle organic storage. The perchloroethylene bottoms (stream 21) are
neutralized with ammonia in the perchloroethylene neutralizer and then dried in
the perchloroethylene dryer to obtain the finished perchloroethylene (stream 22)
that is sent to the perchloroethylene storage.
If any C2 chlorinated organics (stream 23) from other processes are fed to the
process, they may be combined with the recycled lights and recovered organics
(streams 13, 18, and 20) and the combined recycle organics (stream 24) fed to
the reactor.
The hydrogen chloride absorber vent (A), which releases the inert gases from
the oxygen, chlorine, and hydrogen chloride feeds, is a source of process emis-
sions. Other sources of process emissions are the drying column vent (B) and
the distillation column vents (C), which release primarily noncondensable gases,
and the trichloroethylene and the perchloroethylene neutralizer vents (D), which
relieve excess pressure of the nitrogen pads on the systems. Storage emisson
sources (vents E) are raw material storage, recycle storage, and product storage.
Handling emissions (F) can occur during the loading of perchloroethylene and
trichloroethylene into drums, tank trucks, tank cars, barges, or ships for ship-
ment.
Fugitive emissions (G) occur when leaks develop in valves or in pump seals.
When process pressures are higher than the cooling-water pressure, VOC can leak
into the cooling water and escape as a fugitive emission from the cooling tower.
Secondary emissions can occur when wastewater containing VOC is sent to a waste-
water treatment system or lagoon and the VOC are desorbed (H). Another source
of secondary emissions is the combustion of tars in an incinerator where VOC
are emitted with the flue gases (I).
-------
111-15
D. VINYLIDENE CHLORIDE
Vinylidene chloride is produced domestically by the dehydrochlorination of
1,1,2-trichloroethane as represented by the following reaction:8'13'14
CH2C1-CHC12 + NaOH > CH2=CC12 + NaCl + H20
(1,1,2-trichloroethane) (sodium (vinylidene (sodium (water)
hydroxide) chloride) chloride)
The reaction is carried out in the liquid phase at a temperature of about 100°C,
with a relatively dilute (5 to 10 wt %) sodium hydroxide solution. Product yields
are believed to range from 85 to 90%.13
Figure I1I-5 represents a flow diagram for a process in which vinylidene chloride
is produced from 1,1,2-trichloroethane.8'13'14 Concentrated sodium hydroxide
solution (stream 1) is diluted with water (stream 2) to 5 to 10% concentration
and combined with 1,1,2-trichloroethane feed (stream 3), with unreacted 1,1,2-tri-
chloroethane (stream 16) recycled from the distillation section of the process,
and with a recycled sodium hydroxide—salt solution (stream 8). The combined
feed stream (4) is further mixed to provide dispersal of the insoluble organic
phase in the aqueous phase before it is fed to the dehydrochlorination reactor.
The dehydrochlorination reactor is continuously purged with nitrogen (stream 5)
to prevent the accumulation of monochloroacetylene impurity in the vinylidene
chloride product, a step that results in a process emission source (vent A).
The two-phase reactor effluent (stream 6) is separated into two streams. The
aqueous phase (stream 7), composed of a sodium hydroxide—salt solution saturated
with organic compounds, is split. One fraction (stream 8) is recycled to the
dehydrochlorination reactor. The other fraction (stream 9) is combined with
the bottom stream (14) from the drying column and fed to the stripping column,
where steam (10) is introduced countercurrently to strip most of the dissolved
organics from the aqueous phase. The organics (stream 11) are removed overhead
and are combined with the organic phase (stream 12) from the phase separator as
feed to the drying column. The stripped aqueous phase is removed as the bottom
stream (source F) and discharged to the wastewater treatment system.
-------
I
M
cr>
COLUMM
Fig. III-5. Flow Diagram for Vinylidene Chloride from 1,1,2-Trichloroethane
-------
111-17
The drying column bottom stream (14), which contains most of the residual water,
is recycled to the stripping column. The drying-column overhead stream (15)
passes to the finishing column, where the overhead stream (16), composed primarily
of unreacted 1,1,2-trichloroethane, is removed and recycled to the dehydrochlori-
nation reactor. The refined vinylidene chloride product is removed as the bottom
stream (17) and transferred to storage in pressurized tanks. From storage the
vinylidene chloride may be transferred by pipeline for internal use (stream 18)
or loaded (stream 19) into tank trucks and tank cars for off-site consumption.
The dehydrochlorination reactor purge vent (A) and the distillation column vents,
(B) which release primarily noncondensable gases, are sources of process emissions.
Storage emissions (vent C) are the emissions from storage of 1,1,2-trichloroethane.
Handling emissions (vent D) result from the loading of vinylidene chloride into
tank trucks and railroad tank cars. With pressurized tanks used for vinylidene
chloride storage no significant emissions from product storage occur.
Fugitive emissions (E) occur when leaks develop in valves or in pump or compressor
seals. When process pressures are higher than the cooling water pressure, VOC
can leak into the cooling water and escape as fugitive emissions from the cooling
tower.
Secondary emissions can occur when wastewater discharged from the stripping
column (source F) is sent to a wastewater treatment system and the contained
VOC are desorbed.
-------
111-18
E. REFERENCES*
1. S. A. Cogswell, "C2 Chlorinated Solvents," pp. 632.3000A—F and 632.3001A—
632.3002A in Chemical Economics Handbook, Stanford Research Institute, Menlo
Park, CA (December 1978).
2. "1,1,1-Trichloroethane," p 9 in Chemical Marketing Reporter (Jan. 17, 1977).
3. F. C. Dehn, PPG Industries, Inc., letter dated Mar. 14, 1979, to EPA with informati<
on air emissions from the 1,1,1-trichloroethane plant and the perchloroethylene
and trichloroethylene plant at Lake Charles, LA, in response to EPA request.
4. T. A. Leonard, Vulcan Materials Company, letter dated Mar. 8, 1979, to EPA
with information on air emissions from the 1,1,1-trichloroethane plant at Geismar,
LA, in response to EPA request.
5. Z. S. Khan and T. W. Hughes, Monsanto Research Corporation, Source Assessment:
Chlorinated Hydrocarbons Manufacture, June 1977 (preliminary draft on file at
EPA, ESED, Research Triangle Park, NC).
6. L. M. Elkin, Chlorinated Solvents, Report 48, A private report by the Process
Economics Program, Stanford Research Institute, Menlo Park, CA (February 1969).
7. J. B. Worthington, Diamond Shamrock, letter dated Jan. 16, 1979, to EPA with
information on air emissions from the perchloroethylene plant at Deer Park, TX,
in response to EPA request.
8. R. L. Standifer, IT Enviroscience, Inc., Trip Report for Visit to Dow Chemical USA,
Freeport, TX, Nov. 9, 1977 (on file at EPA, ESED, Research Triangle Park, NC) .
9. W. C. Strader, Ethyl Corporation, letter dated Nov. 28, 1978, to EPA with
information on air emissions from the perchloroethylene and trichloroethylene
plant at Baton Rouge, LA, in response to EPA request.
10. F. D. Hobbs and C. W. Stuewe, IT Enviroscience, Inc., Carbon Tetrachloride and
Perchloroethylene (Hydrocarbon Chlorinolysis Process) (in preparation for
EPA, ESED, Research Triangle Park, NC).
11. "PPG Industries: Chlorinated Solvents from Ethylene," Chemical Engineering
76(26), 90, 91 (1969).
12. J. F. Knoop and G. R. Neikirk, "Oxychlorinate for Per/Tri," Hydrocarbon Processing
51 (11), 109, 110 (1972).
-------
111-19
13. Arthur D. Little, Inc., Final Report: Vinylldene Chloride Monomer Emissions from
the Monomer, Polymer, and Polymer Processing Industries, ADR-76086-31, prepared
for the EPA Control Systems Laboratory, Durham, NC (April 1976).
14. J. Beale, Dow Chemical Co. USA, letter dated Oct. 25, 1978, to EPA with information
on air emissions from the vinylidene chloride plant at Plaquemine, LA, in response
to EPA request.
^Usually, when a reference is located at the end of a paragraph, it refers to
the entire paragraph. If another reference relates to certain portions of
that paragraph, that reference number is indicated on the material involved.
When the reference appears on a heading, it refers to all the text covered by
that heading.
-------
IV-1
IV. EMISSIONS
A. INTRODUCTION
Emissions in this report are usually identified in terms of volatile organic
compounds (VOC). VOC are currently considered by the EPA to be those of a
large group of organic chemicals, most of which, when emitted to the atmosphere,
participate in photochemical reactions producing ozone. A relatively small
number of organic chemicals are photochemically unreactive. It should be noted
that although 1,1,1-trichloroethane is included in VOC emission totals in this
report, it does not, based on current research data, participate in ozone-forming
reactions to an appreciable extent. However, many photochemically unreactive
organic chemicals are of concern and may not be exempt from regulation by EPA
under Section 111 or 112 of the Clean Air Act since there are associated health
or welfare impacts other than those related to ozone formation.
B. 1,1,1-TRICHLOROETHANE
1. Vinyl Chloride Process
a. Model Plant* The model plant for the synthesis of 1,1,1-trichloroethane from
vinyl chloride (Fig. III-l) has a capacity of 136,000 Mg/yr based on 8760 hr of
operation annually.** This capacity is typical of recently built plants that
manufacture 1,1,1-trichloroethane from vinyl chloride.1—4 Information about
the specific process steps and the sequence of specific operations for existing
plants was not available,- however, the process shown in Fig. III-l is believed
to be similar to the actual processes used. Characteristics of the model plant
important to air-dispersion modeling are shown in Table B-l in Appendix B.
b- Sources and Emissions Uncontrolled emission sources and rates for the vinyl
chloride—based 1,1,1-trichloroethane process are summarized in Table IV-1.
*See p 1-2 for a discussion of model plants.
**Process downtime is normally expected to range from 5 to 15%. If the hourly
rate remains constant, the annual production and the annual VOC emissions will
be correspondingly reduced. Control devices will usually operate on the same
cycle as the process. From the standpoint of cost-effectiveness calculations,
the error introduced by assuming continuous operation is negligible.
-------
IV-2
Table IV-1. Estimates of Total Uncontrolled VOC Emissions from
a Model Plant Producing 1,1,1-Trichloroethane from Vinyl Chloride (136,000 Mg/yr)'
Source
Vent
Designation
(Fig.III-1)
VOC Emissions
Ratio
(g/kg)*
Rate
(kg/hr)
Distillation vents
Storage vents
Intermediate storage
Product storage
Handling—loading tank
trucks and tank cars
Fugitive
Secondary
Wastewater treatment
Incineration of resi-
dues and/or landfill
Total
B
C
D
F
G,H
0.19
0.15C
0.40d
0.61
1.26
0.001
<0.001
2.6
3.0
2.3
6.2
9.5
19.5
0.02
<0.01
40.5
Uncontrolled emissions are emissions from a process for which
there are no control devices other than those necessary for
economical operation.
g of emissions per kg of 1,1,1-trichloroethane produced.
°Includes approximately 60% nonreactive VOC (1,1,1-trichloroethane)
Primarily nonreactive VOC (1,1,1-trichloroethane).
-------
IV-3
Distillation vent The gas vented from the distillation columns reflux condensers
(vents A, Fig. III-l), primarily noncondensable nitrogen and oxygen, is the
only significant source of process emissions. The estimated composition of the
uncontrolled distillation vent gas, shown in Table IV-2, is based on a reported
composition after the use of a control device5 and on an estimated VOC removal
efficiency of 90% for the control.6
Storage and handling emissions Emissions result from intermediate process
storage and from the storage of refined 1,1,1-trichloroethane. Sources for the
model plant are shown in Fig. III-l (sources B and C). Storage tank data for
the model plant are given in Table IV-3. The uncontrolled storage emissions
were calculated by the use of the emission eguations from AP-42,7 and are based
on fixed-roof tanks, half full, with a diurnal temperature variation of 11°C.
The calculated values for breathing losses were divided by 4 to account for
recent evidence that the AP-42 breathing-loss equation overpredicts emissions.
Handling emissions result from the loading (source D) of 1,1,1-trichloroethane
into tank cars and tank trucks for shipment. These emissions are shown in Table IV-1
and were calculated with the equations from AP-42,7 based on the submerged loading
of 1,1,1-trichloroethane at 27°C and with all the production being shipped in
tank cars and tank trucks. Storage and handling emissions, the most signifi-
cant source of emissions from the model plant, account for about 75% of the
uncontrolled emissions.
Fugitive emissions Process pumps, compressors, process valves, and pressure-relief
devices are potential sources of fugitive emissions (source E). The model plant
is estimated to have 30 pumps, 2 compressors (with 2 seals), 1000 process valves,
and 15 pressure-relief devices handling VOC. The actual number of each component
used in existing 1,1,1-trichloroethane plants was not available,- therefore they
were estimated based on the average numbers of components in service in plants
producing chloromethanes.8 Pumps, compressors, process valves, and pressure-relief
valves not handling VOC are not included in these estimates. The fugitive emission
factors from Appendix C were applied to these estimates, and the results are
shown in Table IV-1 as fugitive emissions.
Secondary emissions Secondary VOC emissions can result from the handling and
disposal of process waste streams. For the model plant three potential sources
are indicated on the flow diagram (sources F, G and H).
-------
IV-4
Table IV-2. Estimated Composition of
Distillation Vent Gas from Model Plant Producing
1,1,1-Trichloroethane from Vinyl Chloride*
Component Composition (wt %)
Vinyl chloride 0.1
Ethylene dichloride 2.5
Total VOC 2.6
Oxygen, nitrogen
Carbon dioxide
Total
*See refs 5 and 6.
-------
IV-5
Table IV-3. Storage Tank Data for 1,1,1-Trichloroethane
(Vinyl Chloride Feed) Model Plant
Contents
Number of tanks
Tank size (m )
Turnovers per year
Bulk temperature (°C)
Intermediate
Crude 1,1-di-
chloroethane
3
189
13
27
Tank
Intermediate
Crude 1,1,1-tri-
chloroe thane
2
98
52
27
Product
Refined 1,1,1-tri-
chloroethane
4
598
86
27
-------
IV-6
The estimate of secondary emissions from wastewater treatment (source F) for
the model plant is based on steam-stripping of all wastewater containing VOC
for recovery of the contained organics before the water is discharged to the
wastewater treatment system.4 Emissions from wastewater treatment and landfill
of residues will be discussed in a future EPA report on secondary emissions.
The venting of flue gas produced from the combustion of liquid residues (source H)
in an incinerator results in the secondary emission of VOC. Specific information
as to the quantity and composition of the residues that are burned was not availabl
however, estimates previously made for similar processes9'10 indicate that emission
from this source are characteristically low, as are emissions resulting from the
landfill of solid residues (G). The estimated emissions shown in Table IV-1
are based on the previous estimates.
2. Ethane Process
a. Model Plant The model plant for the synthesis of 1,1,1-trichloroethane from
ethane (Fig. III-2) has a capacity of 29,500 Mg/yr based on 8760 hr of operation
annually. This is the reported capacity of the Vulcan Materials Company plant
at Geismar, LA, the only plant currently using the ethane process for the manu-
facture of 1,1,1-trichloroethane.3'11 Information concerning specific process
steps and the sequence of specific operations was not available for the Vulcan
process. The flow diagram for the model plant (Fig. III-2) was based primarily
on information obtained from general references12'13 and does not specifically
represent the process used by Vulcan. Characteristics of the model plant important
to air-dispersion modeling are shown in Table B-2 in Appendix B.
b. Sources and Emissions Emission sources and rates for the ethane-based 1,1,1-tri-
chloroethane process are summarized in Table IV-4.
Distillation vents The gas vented from the distillation-column reflux condenser
vents (A, Fig. III-2) is the only significant source of process emissions. The
estimated composition of the uncontrolled distillation vent gas is shown in
Table IV-5.
-------
IV-7
Table IV-4. Estimates of Total Uncontrolled VOC Emissions from
a Model Plant Producing 1,1,l-Trichlor©ethane from Ethane (29,500 Mg/yr)
Source
Distillation vents
Storage vents
Recycle storage
Product storage
Handling
Fugitive
Secondary
Wastewater treatment
Incineration of residues
and/or landfill
Total
Vent
Designation
(Fig.III-2)
A
B
C
D
E
F
G,H
VOC Emissions
Ratio
(g/kg)b
0.21°
0.15d
0.40e
0.61
5.79
0.001
<0.003
7.2
Rate
(kg/hr)
0.7
0.5
1.4
2.1
19.5
0.004
<0.01
24.2
Uncontrolled emissions are emissions from a process for which
there are no control devices other than those necessary for
economical operation.
g of emission per kg of 1,1,1-trichloroethane produced.
clncludes approximately 65% nonreactive VOC (1,1,1-trichloroethane)
Includes approximately 60% nonreactive VOC (1,1,1-trichloroethane)
Primarily nonreactive VOC (1,1,1-trichloroethane) .
-------
IV-8
Table IV-5. Estimated Composition of
Distillation Vent Gas from Model Plant Producing
1,1,1-Trichloroethane from Ethane*
Component Composition (wt %)
1,1,1-Trichloroethane 35
Ethylene dichloride 17
Nitrogen, oxygen 48
Total 100
*See ref 10.
-------
IV-9
Storage and handling emissions Emissions result from intermediate process
storage and from the storage or handling of refined 1,1,1-trichloroethane.
Sources for the model plant are shown in Fig. III-2 (sources B, C, and D).
Specific storage requirements for the ethane-based 1,1,1-trichloroethane process
were not available.
Storage and handling emissions result primarily from the storage and handling
of 1,1,1-trichloroethane. As the corresponding emissions are primarily dependent
on plant capacity and throughput and are not significantly affected by the process
used, the estimated storage and handling emissions for the ethane-based 1,1,1-tri-
chloroethane model plant given in Table IV-4 were developed by prorating the storage
and throughput data for the vinyl-chloride—based 1,1,1-trichloroethane model plant
(Table IV-3) to those for the smaller ethane-based model plant (see Table IV-6).
Fugitive emissions Process pumps, compressors, process valves, and pressure
relief devices are potential sources (E) of fugitive emissions. The model plant
is estimated to have 30 pumps, 2 compressors (with 2 seals), 1000 process valves,
and 15 pressure-relief devices handling VOC. Since the actual number of each
component used in the existing 1,1,1-trichloroethane plant was not available,
they were estimated based on the average numbers of components in service in
plants producing cloromethanes.8 Pumps, compressors, and valves not handling
VOC are not included in these estimates. The fugitive emission factors from
Appendix C were applied to these estimates and the results are shown in Table IV-4
as fugitive emissions.
Secondary emissions Secondary VOC emissions can result from the handling and
disposal of process waste streams. For the model plant three potential sources
(F, G, and H) are indicated on Fig. III-2.
The estimate of secondary emissions from wastewater treatment (source F) for
the model plant is based on steam-stripping of all wastewater containing VOC
for recovery of the contained organics before the water is discharged to the
wastewater treatment system. Emissions from wastewater will be discussed in a
future EPA report on secondary emissions.
-------
IV-10
Table IV-6.
Storage Tank Data for 1,1,1-Trichloroethane
(Ethane Feed) Model Plant
Contents
Number of tanks
Tank size (m )
Turnovers per year
Bulk temperature (°C)
Intermediate
1,1-Dichloro-
ethane
4
55
11
27
Tank
Intermediate
Crude 1,1,1-tri-
chloroe thane
2
29
44
27
Product
Refined 1,1,1-tri-
chloroethane
4
174
73
27
-------
IV-11
The venting of flue gas produced from the combustion of liquid and semisolid
residues in an incinerator results in the secondary emissions of VOC. Specific
information as to the quantity and compostion of the residues that are burned
was not available; however, estimates previously made for similar processes9'10
indicate that emissions from this source are characteristically low. The esti-
mated emissions shown in Table IV-4 are based on the previous estimates.
C. PERCHLOROETHYLENE AND TRICHLOROETHYLENE
1. Chlorination
The flow diagram shown in Fig. III-3 was based on information from producers of
perchloroethylene and trichloroethylene5'13/14 and on general engineering judge-
ment. Because some details of the processes are considered to be confidential
or were not given, the actual processes used may differ from those shown. A
capacity of 70,000 Mg/yr based on 8760 hr of operation per year was chosen as
being most representative of the three plants that produce perchloroethylene
and/or trichloroethylene by chlorination of ethylene dichloride.
The estimate of the uncontrolled process emissions given in Table IV-7 does not
include uncontrolled storage, handling, fugitive, or secondary emissions. The
estimate is based on a weighted average of uncontrolled process emissions reported
by perchloroethylene and trichloroethylene producers.5'14'15 Storage, handling,
fugitive, and secondary emissions for the entire synthetic organic chemicals
manufacturing industry are covered by separate EPA documents.
The composition and flow of the gas from a neutralization and drying area vent
(A), based on data from one producer, are given in Table IV-8, and similar data
on the distillation vent (B) are given in Table IV-9.14
2. Oxychlorination
The flow diagram shown in Fig. III-4 represents a plant producing perchloroethylene
and trichloroethylene by the oxychlorination process with a capacity of 180,000 Mg/yr
based on 8760 hr of operation per year. It is based on the literature and on in-
formation from the one producer of perchloroethylene and trichloroethylene who uses
this process. The estimate of the uncontrolled process emissions given in Table IV-7
-------
IV-12
Table IV-7. Estimates of Uncontrolled Process VOC Emissions from Processes
Producing Perchloroethylene, Trichloroethylene, and Vinylidene Chloride
VOC Emissions
Process
Chlorination
Oxychlorination
Dehydrochlorination
Product
Perchloroethylene
and/or trichloroethylene
Perchloroethylene
and trichloroethylene
Vinylidene chloride
Capacity
(Mg/yr)
70,000
180,000
90,000
Ratio
(g/kg) b
8
24
8
Rate
(kg/hr)
64
500
82
SStorage, handling, fugitive, and secondary emissions are not included in these data.
g of emission per kg of product produced.
-------
IV-13
Table IV-8. Estimated Composition of Neutralization and
Drying Vent Gas from a Perchloroethylene Plant
Component
Ethylene dichloride
Vinylidene chloride
trans-Dichloroethylene
cis-Dichloroethylene
Carbon tetrachloride
Trichloroethylene
Perchloroethylene
Total VOC
Water
Air
Total
Composition
(wt %)
30.5
25.1
10.9
2.91
0.64
1.08
4.99
76
0.02
24
100
b
Emission Ratio
(g/kg)
3.1
2.5
1.1
0.29
0.064
0.11
0.50
7.6
0.002
2.4
10
aSee ref 14.
g of emission per kg of perchloroethylene produced.
-------
IV-14
Table IV-9. Estimated Composition of Distillation Vent
Gas from a Perchloroethylene Planta
Component
Vinylidene chloride
trans-Dichloroethylene
cis-Dichloroethylene
Carbon tetrachloride
Trichloroethylene
Perchloroethylene
Total VOC
Air
Total
Composition
(wt %)
10.6
7.5
4.3
2.6
5.6
9.9
40.5
59.5
100.0
Emission Ratio
(g/kg)b
0.106
0.075
0.043
0.026
0.056
0.099
0.40
0.60
1.0
aSee ref 14.
b
g of emission per kg of perchloroethylene produced.
-------
IV-15
does not include storage, handling, fugitive, or secondary emissions. The compositio
and flow of the uncontrolled emissions in the gas from the reactor vent (A), in
the gas from the drying column vent (B), and in the gas from the distillation
vents (C) are given in Tables IV-10—12 respectively.4'16'17
D. VINYLIDENE CHLORIDE
The process flow diagram (Fig. III-5) for the production of vinylidene chloride
from 1,1,2-trichloroethane represents the processes used by Dow Chemical Company5'18
and PPG Industries, currently the only domestic producers of vinylidene chloride.2'3
Emissions from the reactor vent (A) are composed of vinylidene chloride, monochloro-
acetylene, and nitrogen and result from the purging of the reactor to prevent
the accumulation of monochloroacetylene in the liquid vinylidene chloride product.
An estimate of the reactor vent gas composition is given in Table IV-13.
An estimate of the composition of the distillation column vent (B), the other
source of process emissions, is given in Table IV-14. The estimated quantities
of emissions from both sources (vents A and B) are based on information from
two plants6'18 and the total is given in Table IV-7.
-------
IV-16
Table IV-10. Estimated Composition of Reactor Vent
Gas from an Oxychlorination Plant for Perchloroethylene and
Trichloroethylene3
Component
Chlorinated C2 ' s (VOC)
Hydrogen chloride
Carbon dioxide
Nitrogen
Total
Composition
(wt %)
22.5
0.5
69.5
7.5
100
Emission Ratio53
(g/kg)
21.3
0.5
65.5
7.1
94.4
See ref 4.
g of emission per kg of perchloroethylene and trichloro-
ethylene produced.
-------
IV-17
Table IV-11. Estimated Composition of Drying Column Vent
Gas from an Oxychlorination Plant for
Perchloroethylene and Trichloroethylenea
Component
trans-Dichloroethylene
Vinyl chloride
Vinylidene chloride
Perchloroethylene /tr i-
chloroethylene
Other chlorinated C 's
Total VOC
Nitrogen
Total
Composition
(wt %)
26.0
21.0
16.0
0.3
24.7
88.0
12.0
100
Emission Ratio
(g/kg}k
0.65
0.52
0.40
0.0075
0.62
2.2
0.30
2.5
See ref 4.
g of emission per kg of perchloroethylene and trichloro-
ethylene produced.
-------
IV-18
Table IV-12. Estimated Composition of Distillation Vent
Gas from an Oxychlorination Plant for
Perchloroethylene and Trichloroethylene3
Component
trans-Dichloroethylene
cis-Dichloroethylene
Vinylidene chloride
Perchloroethylene
Trichloroethylene
Other chlorinated C 's
Total VOC
Nitrogen
Total
Composition
(wt %)
39
11
17
13
13
2
95
5
100
Emission Ratio
(g/kg)b
0.225
0.063
0.098
0.075
0.075
0.012
0.55
0.029
0.58
See ref 4.
g of emission per kg of perchloroethylene and trichloro-
ethylene produced.
-------
IV-19
Table IV-13. Estimated Composition of Vent Gas from
Reactor Section of a Vinylidene Chloride Planta
Component
Vinylidene chloride
Monochloroacetylene
Nitrogen
Composition
(wt %)
56
8
36
Emission Ratio
(g/kg)b
6.2
0.9
4.0
SSee refs 3, 4, and 5.
g of emissions per kg of product produced.
-------
IV-20
Table IV-14. Estimated Composition of Distillation
Vent Gas from a Vinylidene Chloride Plant3
Component
Vinylidene chloride
Nitrogen
Composition
(wt %)
50
50
Emission Ratio
(g/kg)b
0.7
0.7
aSee ref 18.
of emissions per kg of product produced.
-------
IV-21
E. REFERENCES*
1. "1,1,1-Trichloroethane," p 9 in Chemical Marketing Reporter (Jan. 17, 1977).
2. S. A. Cogswell, "Ethylene Bichloride," p. 651-5032M in Chemical Economics Handbook,
Stanford Research Institute, Menlo Park, CA (February 1979).
3. S. A. Cogswell, "C2 Chlorinated Solvents," p. 632.3001T in Chemical Economics
Handbook, Stanford Research Institute, Menlo Park, CA (December 1978).
4. F. C. Dehn, PPG Industries, letter dated Mar. 14, 1979, to EPA with information
on air emissions from the 1,1,1-trichloroethylene, perchloroethylene, and trichloro-
ethylene plants at Lake Charles, LA, in response to EPA request.
5. R. L. Standifer, IT Enviroscience, Inc., Trip Report for Visit to Dow Chemical Co.,
Freeport, TX, Nov. 9, 1977 (on file at EPA, ESED, Research Triangle Park,
NC).
6. B. Dellamea, Dow Chemical, Freeport, TX, Texas Air Control Board Emissions
Inventory Questionnaire for 1975.
7. C. C. Masser, "Storage of Petroleum Liquids," pp. 4.3-1—4.3-16 in Compilation
of Air Pollutant Emission Factors. 3d ed., Part A, AP-42, EPA, Research Triangle
Park, NC (August 1979).
8. D. G. Erikson and V. Kalcevic, IT Enviroscience, Inc., Fugitive Emissions
(September 1980) (EPA/ESED report, Research Triangle Park, NC).
9. F. D. Hobbs and C. W. Stuewe, IT Enviroscience, Inc., Chloromethanes.
Methane Chlorination Process (in preparation for EPA, ESED, Research Triangle
Park, NC).
10. F. D. Hobbs and C. W. Stuewe, IT Enviroscience, Inc., Carbon Tetrachloride and
Perchloroethylene (Hydrocarbon Chlorinolysis Process) (in preparation for EPA,
ESED, Research Triangle Park, NC).
11. T. A. Leonard, Vulcan Materials Co., letter dated Mar. 8, 1979, to EPA with
information on air emissions from the 1,1,1-trichloroethane plant at Geismar,
LA, in response to EPA request.
12. L. M. Elkin, Chlorinated Solvents Report, Report No. 48, A private report by
the Process Economics Program, Stanford Research Institute, Menlo Park, CA
(February 1969).
13. Z. S. Khan and T. W. Hughes, Monsanto Research Corporation, Source Assessment:
Chlorinated Hydrocarbon Manufacture, June 1977 (preliminary draft on file at
EPA, ESED, Research Triangle Park, NC).
14. J. B. Worthington, Diamond Shamrock, letter dated Jan. 16, 1979, to EPA with
information on air emissions from the perchloroethylene plant at Deer Park, TX,
in response to EPA request.
-------
IV-2 2
15. W. C. Strader, Ethyl Corp., letter dated Nov. 28, 1978, to EPA with information
on air emissions from the perchloroethylene and trichloroethylene plant at Baton
Rouge, LA, in response to EPA request.
16. "PPG Industries: Chlorinated Solvents from Ethylene," Chemical Engineering
76(26), 90,91 (1969).
17. J. F. Knoop and G. R. Neikirk, "Oxychlorinate for Per/Tri," Hydrocarbon Processing
51(11), 109,110 (1972).
18. J. Beale, Dow Chemical, letter dated Oct. 25, 1978, to EPA with information on
air emissions from the vinylidene chloride plant at Plaquemine, LA, in response
to EPA request.
*Usually, when a reference is located at the end of a paragraph, it refers to
the entire paragraph. If another reference relates to certain portions of
that paragraph, that reference number is indicated on the material involved.
When the reference appears on a heading, it refers to all the text covered by
that heading.
-------
V-l
V. APPLICABLE CONTROL SYSTEMS
A. 1,1,1-TRICHLOROETHANE
1. Vinyl Chloride Process
a- Distillation Vent The stream from the distillation vents (vent A) is the only
significant process emission source. The control option selected for the model-
plant distillation vent is combustion in an existing incinerator. An estimated
VOC reduction of 98% was used to calculate the controlled emissions from this
source (see Table V-l), based on the emission factors from AP-42.1 As the
installation of an incinerator solely for the purpose of controlling this source
would not be justifiable, this control method is applicable only if an existing
combustion chamber can be used. Also, the relatively low concentration of com-
bustible VOC present in this stream (see Table IV-2) would necessitate the use
of supplementary fuel to attain the required incineration temperature.
Another option used for the control of the VOC in the distillation vent gases
is aqueous scrubbing. An estimated VOC removal efficiency of 90% is attained
by one producer using this method.2 A potential disadvantage of aqueous scrubbing
is that a large part of the VOC removed may be emitted as secondary emissions
from the effluent water unless the water is subsequently stripped before discharge
to the wastewater treatment system.3 Another disadvantage of aqueous scrubbing
is that it is relatively ineffective for the control of the contained vinyl
chloride because of the high vapor pressure and low water solubility of vinyl
chloride. (Vinyl chloride has been listed as a hazardous pollutant by EPA.)
b- Storing and Handling Emissions The emissions from the model-plant storage
tanks and from the loading of tank cars, tank trucks, and drums are controlled
by refrigerated vent condensers.2 Options for control of storage and handling
emissions are covered in another EPA report.4 Guidelines for storage and
handling emission control techniques will be given in a future EPA document.
The controlled storage and handling emissions are given in Table V-l. VOC removal
efficiencies were estimated to be 85% for both storage and handling emissions,
-------
Table V-l. Estimates of Controlled VOC Emissions from a Model Plant Producing
1,1,1-Trichloroethane from Vinyl Chloride (136,000 Mg/yr)
,
Designation
con-rr-P (Fiq.III-1)
ou m. •— • *— v -*
Distillation vent A
Storage vents
Intermediate storage B
Product storage c
Handling — loading tank D
cars and tank trucks
Fugitive E
Secondary
Wastewater treatment F
Incineration of residue G,H
or landfill
Total
• •
Control Device or Technique
Combustion in incinerator
Refrigerated vent condenser
Refrigerated vent condenser
Refrigerated vent condenser
Detection and correction of
major leaks
None
None
Total VOC
Emission
Reduction
(%)
98
85
85
85
90
VOC End
Ratio
(g/kg) *
0.004
0.022
0.061
0.090
0.277
0.001
<0.001
0.46
.ssions
Rate
(kg/hr)
0.06
0.35
0 .94
1.4
4.3
Ort rt
.02
-------
V-3
based on a refrigerated vent condenser effluent temperature of -10°C.2 Higher
removal efficiencies can be attained at lower temperatures, with correspondingly
higher capital and operating costs and energy requirements.4
A refrigerated absorption system is used by one producer to control storage
emissions.5 The efficiency of this system was not reported.
c- Fugitive Emissions Controls for fugitive emissions from the synthetic organic
chemicals manufacturing industry will be discussed in a future EPA document.
Emissions from pumps and valves can be controlled by an appropriate leak-detection
system and repair and maintenance as needed. Controlled fugitive emissions
calculated with the factors given in Appendix C are included in Table V-l; these
factors are based on the assumption that major leaks are detected and corrected.
d- Secondary Emissions Secondary emissions can occur from wastewater treatment
and from incineration or landfill of residues.
Wastewater treatment Estimates of VOC emissions from wastewater treatment
indicate they are very small. These estimates are based on the assumption that
wastewater streams with significant VOC concentration are steam-stripped to
recover the contained organic compounds before the wastewater is discharged to
the treatment system.5 No additional control system has been identified for
the model plant. Control of secondary emissions will be discussed in a future
EPA report.
Incineration or landfill of residues Estimates of the VOC emissions resulting
from the disposal of liquid and solid residues either by incineration or by
landfill indicate they are very small. No control system has been identified
for the model plant.
2. Ethane Process
The controlled emission rates and ratios, the control devices or techniques
selected, and the estimates of the emission reductions attained for the ethane-
based 1,1,1-trichloroethane model plant are given in Table V-2. The comments
on specific emission sources and controls for the vinyl chloride—based model
plant, presented in Sect. V-A1, also apply to the ethane model.
-------
Table V-2. Estimates of Controlled VOC Emissions from a Model Plant Producing
1,1,1-Trichloroethane from Ethane (29,500 Mg/yr)
Source
Distillation vent
Storage vents
Intermediate storage
Product storage
Handling — loading tank
cars and tank trucks
Fugitive
Secondary
Wastewater treatment
Incineration of residue
or landfill
Total
Vent
Designation
(Fig.III-1)
A
B
C
D
E
F
G,H
Control Device or Technique
Combustion in incinerator
Refrigerated vent condenser
Refrigerated vent condenser
Refrigerated vent condenser
Detection and correction of
major leaks
None
None
Total VOC
Emission
Reduction
(%)
98
85
85
85
90
VOC
Ratio
(g/kg) *
0.004
0.023
0.060
0.090
1.28
0.001
<0.003
1.5
Emissions
Rate
(kg/hr)
0.014
0.08
0.21
0.30
4.3
0.004
<0.01
4.9
<
*g of emission per kg of 1,1,1-trichloroethane produced.
-------
V-5
B. PERCHLOROETHYLENE AND TRICHLOROETHYLENE
1. Chlorination
Refrigerated vent condensers were selected as the control devices for the neutrali-
zation and drying area and the distillation vents (A and B, Fig. III-3), and
their VOC removal efficiency was estimated to be 80% (see Table V-3), based on
limited data from producers of perchloroethylene and trichloroethylene.2'6'7
2. Oxychlorination5
The estimate of controlled VOC emissions from the oxychlorination process given
in Table V-3 is based on the use of thermal oxidizers to control the emissions
from the hydrogen chloride absorber vent (A) and the drying column vent (B),
with water scrubbers used to control the emissions from the distillation columns
vents (C) and product neutralizer vents (D). The combined VOC emissions reduc-
tion is about 98% and is based on data reported by PPG. The installation of a
thermal oxidizer to control only the emissions from a perchloroethylene/ tri-
chloroethylene process may not be so cost effective as the multipurpose incine-
ration used by PPG.
C. VINYLIDENE CHLORIDE
The estimate of the total controlled process emissions for plants producing
vinylidene chloride (Table V-3) was developed from the estimated efficiencies
of devices currenty in use by the industry.2'8 The devices selected as control
options for the separate sources and the corresponding emission ratios and
efficiencies are given in Table V-4.
-------
Table V-3. Estimates of Controlled Process VOC Emissions from Processes Producing Perchloroethylene,
Trichloroethylene, and Vinylidene Chloride
Process
Chlorination
Oxychlorination
Dehydrochlorination
Product
Perchloroethylene and/or
trichloroethylene
Perchloroethylene and
trichloroethylene
Vinylidene chloride
Capacity
(Mg/yr)
70,000
180,000
90,000
Control Device
Refrigerated condensers
Thermal oxidizers and
water scrubbers
Thermal oxidizer and
water scrubber
VOC
Emission
Reduction
(%)
80
98
97
VOC Emissions3
Ratio
(g/kg)
1.6
0.55
0.2
Rate
(kg/hr )
13
10
2
Storage handling, fugitive, and secondary emissions are not included in these data.
a
g of emission per kg of product produced.
-------
V-7
Table V-4. Estimates of Controlled VOC Emissions from a
Vinylidene Chloride Process3
Uncontrolled VOC VOC Emission
Emission Ratio Reduction
Source (g/kg)*3 Control Device (%)
Reactor vent 7.1 Incineration 98
Distillation vent 0.7 Aqueous scrubber 90
Total 7.8
Controlled VOC
Emission Ratio
(g/kg)b
0.
0.
0.
14
07
21
See refs 2 and 8.
g of emissions per kg of vinylidene chloride produced.
-------
V-8
D. REFERENCES*
1. T. Lahre, "Natural Gas Combustion," pp. 1.4.-1—1.4-3 in Compilation of Air
Pollutant Emission Factors, 3d ed., Part A, AP-42, EPA, Research Triangle Park,
NC (August 1977).
2. R. L. Standifer, IT Enviroscience, Inc., Trip Report for Visit to Dow Chemical,
Freeport, TX, Nov. 9, 1977 (on file at EPA, ESED, Research Triangle Park,
NC).
3. L. J. Thibodeaux, "Air Stripping of Organics from Wastewater. A Compendium,"
pp. 358—H378 in the Proceedings of the Second National Conference on Complete
Watereuse. Water's Interface with Energy, Air, and Solids, Chicago, IL, May 4—8,
1975, sponsored by AIChE and EPA Technology Transfer.
4. D. G. Erikson, IT Enviroscience, Inc., Storage and Handling (September 1980)
(EPA/ESED report, Research Triangle Park, NC).
5. F. C. Dehn, PPG Industries, letter dated Mar. 14, 1979, to EPA with information
on air emissions from the 1,1,1-trichloroethane plant at Lake Charles, LA, in
response to EPA request.
6. J. B. Worthington, Diamond Shamrock, letter dated Jan. 16, 1979, to EPA with
information on air emissions from the perchloroethylene plant at Deer Park,
TX, in response to EPA request.
7. W. C. Strader, Ethyl Corporation, letter dated Nov. 28, 1978, to EPA with
information on air emissions from the perchloroethylene and trichloroethylene
plant at Baton Rouge, LA, in response to EPA request.
8. J. Beale, Dow Chemical, letter dated Oct. 25, 1978, to EPA with information on
air emissions from the vinylidene chloride plant at Plaquemine, LA, in response
to EPA request.
^Usually, when a reference is located at the end of a paragraph, it refers to
the entire paragraph. If another reference relates to certain portions of
that paragraph, that reference number is indicated on the material involved.
When the reference appears on a heading, it refers to all the text covered by
that heading.
-------
VI-1
VI. IMPACT ANALYSIS
A. 1,1,1-TRICHLOROETHANE
1. Environmental and Energy Impacts
a.
Vinyl Chloride Process Table VI-1 shows the environmental impact of reducing
the total VOC emissions by application of the described control systems (Sect. V)
to the model plant described in Sects. Ill and IV. Use of these control devices
or techniques results in the reduction of total VOC emissions by 87%, or about
250 Mg/yr for the model plant, resulting in controlled emissions from the model
plant of about 37 Mg/yr.
Distillation vent The incineration of the gas vented from the distillation
columns reduces the model-plant total VOC emissions by 26 Mg/yr and consequently
reduces the emission of contained vinyl chloride from this source by 1 Mg/yr to
about 0.02 Mg/yr (vinyl chloride is listed as a hazardous pollutant by EPA).
Because of the low concentration of organics in this stream (2.6 wt %) a net
usage of supplementary fuel is required; however, if the recovery of energy
from the combustion products is employed,1'2 the energy impact will be
negligible.
The combustion of chlorinated organic compounds results in the presence of hydrogen
chloride in the flue gas, and control of the resulting hydrogen chloride emissions
may be necessary.
The use of an existing incinerator has the disadvantage of possibly being unavail-
able when other process units are down.
Other emissions (storage, handling, and fugitive) Storage and handling emissions
are controlled in the model plant by refrigerated vent condensers, and fugitive
emissions are controlled by the repair of leaking components. Application of
these controls results in a VOC emission reduction of 223 Mg/yr for the model
plant. Energy requirements for the control of storage and handling emissions
are covered in a separate EPA report.3
-------
VI-2
Table VI-1.
Environmental Impact of Controlled Model Plant Producing
1,1,1-Trichloroethane from Vinyl Chloride
Emission Source
Distillation vent
Vent
Designation
(Fig.III-1)
A
Control Device or Technique
Combustion in incinerator
VOC Emission
Reduction
(%) (Mg/yr)
98 26
Storage vents
Intermediate storage
Product storage
Handling—loading tank
cars and tank trucks
Fugitive
Secondary
Wastewater treatment
Incineration of residue
or landfill
Total
B
C
D
F
G,H
Refrigerated vent condensers 85
Refrigerated vent condensers 85
Refrigerated vent condensers 85
Detection and correction of 90
major leaks
None
None
29
78
71
45
249
-------
VI-3
b- Ethane Process Table VI-2 shows the environmental impact of reducing the total
VOC emissions by application of the described control systems (Sect. V) to the
model plant described in Sects. Ill and IV. Use of these control devices or
techniques results in the reduction of total VOC emissions by 88%, or about
90 Mg/yr for the model plant, resulting in controlled emissions from the model
plant of about 12 Mg/yr.
Distillation vent The incineration of the gas vented from the distillation
columns reduces the model-plant VOC emissions by 6 Mg/yr. The concentration of
VOC in this stream is high (approximately 50%), and auxiliary fuel is not required
for combustion. The hydrogen chloride formed from the combustion of the contained
chlorinated organic compounds may require control of hydrogen chloride in the
flue gas.
Other emissions (storage, handling, and fugitive) Storage and handling emissions
are controlled in the model plant by refrigerated vent condensers, and fugitive
emissions are controlled by the repair of leaking components. Application of
these controls results in a VOC emission reduction of 84 Mg/yr for the model
plant. Energy requirements for the control of storage and handling emissions
are covered in a separate EPA report.3
c- 1979 Industry Emissions The total VOC emissions from the domestic 1,1,1-trichloro-
ethane industry are estimated at 236 Mg and include estimated emissions from the
process, fugitive, secondary, and storage and handling sources. This estimate
is based on a projected 1979 level of production of 323,000 Mg. The estimated
emissions were determined by applying the emission ratios from Tables IV-1,
IV-4, V-l, and V-2. Process emissions are estimated to be 90% controlled, storage
and handling emissions to be 94% controlled, and fugitive emissions to be uncon-
trolled. Emissions from secondary sources are believed to be negligible.
2. Cost Control Impact
The cost control impact described below relates to both the vinyl chloride process
and the ethane process.
-------
VI-4
Table VI-2. Environmental Impact of Controlled Model Plant Producing
1,1,1-Trichloroethane from Ethane
VOC Emission
Vent Reduction
Emission Source
Distillation vent
Storage vents
Intermediate storage
Product storage
Handling — loading tank
cars and tank trucks
Fugitive
Secondary
Wastewater treatment
Incineration of residue
or landfill
Total
resignation
(Fig.III-2) Control Device or Technique (%)
A Combustion in incinerator 98
B Refrigerated vent condensers 85
C Refrigerated vent condenser 85
D Refrigerated vent condensers 85
E Detection and correction of 90
major leaks
F None
G,H None
(Mg/yr)
6
6
17
16
45
—
90
-------
VI-5
a- Process Vents Emissions of VOC from the distillation vent are relatively small
and incineration is feasible only if an existing incinerator can be used; however,
the plants that currently produce 1,1,1-trichloroethane also usually produce
other chlorinated organic compounds4'5 and may dispose of vent gases and chlorinated
residues by incineration.6 The predominant cost of using an existing incinerator
would be installation of the piping necessary to transfer the distillation vent
gas from the 1,1,1-trichloroethane unit to the incinerator. As the cost of the
reguired piping will depend primarily on the distance of the 1,1,1-trichloroethane
plant from the incinerator, which can vary greatly, the cost impact was not
determined.
b- Storage and Handling Sources The control system for storage and handling sources
is the use of refrigerated vent condensers. Another EPA report covers storage
and handling emissions and their applicable controls for all the synthetic organic
chemicals manufacturing industry.3
c- Fugitive Source^ A future EPA document will cover fugitive emissions and their
applicable controls for all the synthetic organic chemicals industry.
d. Secondary Sources No control system has been identified for controlling the
secondary emissions from wastewater treatment or from the disposal of residues
by incineration or landfill. A future EPA document will cover secondary emissions
and their applications for all the synthetic organic chemicals manufacturing
industry.
B. PERCHLOROETHYLENE AND TRICHLOROETHYLENE
1. Environmental Impact
Table VI-3 lists the estimated current VOC emissions from the chlorination process
and from the oxychlorination process for producing perchloroethylene and trichloro-
ethylene. These estimates are based on projected production rates for 1979 of
301,000 Mg of perchloroethylene, of which 108,000 Mg is estimated to be produced
by chlorination or oxychlorination, and 132,000 Mg of trichloroethylene. These
projections were calculated from reported 1977 production and estimated annual
growth rates4'7 and the production rate of each producer was then calculated as
-------
Table VI-3. Estimate of Current Industry Emissions from Processes Producing Perchloroethylene,
Trichloroethylene, and Vinylidene Chloride
Process
1979 VOC
product Control Device Emissions (Mg) *
Chlorination Perchloroethylene and/or Refrigerated condensers 250
trichloroethylene
Oxychlorination Perchloroethylene and Thermal oxidizers and 70
* hlene water scrubbers
trichloroethylene
Dehydrochlorination Vinylidene chloride
water scrubbers
Thermal oxidizers and 20
• ~ <
*Storage handling, fugitive, and secondary emissions are not included in these data. H
-------
VI-7
if all were operating at the same per cent of capacity. The reported emission ratios
by each producer'—" were then applied to projections of production to obtain
the estimated 1979 VOC emissions.
2. Other Impacts
Energy and control cost impacts have not been determined for the control devices
selected in Sect. V.
C. VINYLIDENE CHLORIDE
1- Environmental Impact
The estimated current VOC emissions from the production of vinylidene chloride
are given in Table VI-3. These estimates are based on a projected production
rate for 1979 of 86,000 Mg, determined by adjusting the reported 1978 production
rate by the estimated annual growth rate.* The reported9-^ emission ratios by
producer were then applied to the projections of production to obtain the estimated
1979 VOC emissions.
These estimates include emissions from the processes only, not those from storage
and handling, secondary, or fugitive sources. Emissions from these sources are
believed to be typical for the synthetic organic chemicals manufacturing industry.
2. Other Impacts
Energy and control cost impacts have not been determined for the control devices
selected in Sect. V.
-------
VI-8
D. REFERENCES*
1. Y. H. Kiang, "Controlling Vinyl Chloride Emissions," Chemical Engineering Progress
72(12), 37—41 (1976).
2. C. G. Bertram, "Minimizing Emissions from Vinyl Chloride Plants," Environmental
Science and Technology 11(9), 864—868 (1977).
3. D. G. Erikson, IT Enviroscience, Inc., Storage and Handling (September 1980)
(EPA/ESED report, Research Triangle Park, NC).
4. S. A. Cogswell, "Cg Chlorinated Solvents," pp. 632.3000A—F and 632.3001A—632.3002J
in Chemical Economics Handbook, Stanford Research Institute, Menlo Park, CA
(December 1978).
5. S. A. Cogswell, "Ethylene Bichloride," pp. 651.5031A—F and 651.5032A—561.50331
in Chemical Economics Handbook, Stanford Research Institute, Menlo Park, CA
(Febaruary 1979).
6. F. D. Hobbs and J. A. Key, IT Enviroscience, Inc., Ethylene Bichloride (in
preparation for EPA, ESED, Research Triangle Park, NC).
7. "(632.3001J) C2 Chlorinated Solvents," p. 233 in Chemical Economics Handbook,
Manual of Current Indicators Supplemental Data, Chemical Information Services,
Stanford Research Institute, Menlo Park, CA (April 1979).
8. J. B. Worthington, Diamond Shamrock, letter dated Jan. 16, 1979, to EPA with
information on air emissions from the perchloroethylene plant at Deer Park,
TX, in response to EPA request.
9. R. L. Standifer, IT Enviroscience, Inc., Trip Report for Visit to Dow Chemical USA,
Freeport, TX, Nov. 9, 1977 (on file at EPA, ESED, Research Triangle Park, NC).
10. W. C. Strader, Ethyl Corp., letter dated Nov. 28, 1978, to EPA with information
on air emissions from the perchloroethylene and trichloroethylene plant at Baton
Rouge, LA, in response to EPA request.
11. F. C. Dehn, PPG Industries, Inc., letter dated Mar. 14, 1979, to EPA in response
to request for information on the air emissions from the 1,1,1-trichloroethane,
perchloroethylene, and trichloroethylene processes at Lake Charles, LA.
^Usually, when a reference is located at the end of a paragraph, it refers to
the entire paragraph. If another reference relates to certain portions of
that paragraph, that reference number is indicated on the material involved.
When the reference appears on a heading, it refers to all the text covered by
that heading.
-------
VII-1
VII. SUMMARY
A. 1,1,1-TRICHLOROETHANE
1,1,1-Trichloroethane is currently produced by the chlorination of 1,1-dichloro-
ethane, produced from vinyl chloride and the chlorination of ethane. The domestic
producton capacity of 1,1,1-trichloroethane by the end of 1979 is expected to be
about 590,000 Mg,1 not including the capacity of a plant that produced 1,1,1-tri-
chloroethane from vinylidene chloride, which was shut down in 1978.2 At an
estimated annual growth rate in 1,1,1-trichloroethane consumption of 6%, the
industry is expected to operate at less than capacity through 1981.
Emission sources and uncontrolled and controlled emission rates for the two
model plants are given in Tables VII-1 and VII-2. The only significant process
emission sources of both processes are the distillation vents, which are controlled
in the models by combustion in existing incinerators.
The model-plant 1,1,1-trichloroethane storage and handling emissions are controlled
by refrigerated vent condensers. Potential secondary emissions are minor. The
total 1,1,1-trichloroethane industry VOC emissions are estimated at 218 Mg in
1979, with most of the uncontrolled VOC emissions coming from fugitive, storage,
and handling emissions.
-------
VII-2
Table VII-1.
Emission Summary for 1,1,1-Trichloroethane Model Plant,
Vinyl Chloride Process (136,000 Mg/yr)
Emission
Distillation vent
Storage vents
Intermediate storage
Product storage
Handlino — loading of tank
Vent
Designation
(Fig.III-1)
A
B
C
D
VOC Emission Rate (kg/hr)
Uncontrolled
3.0
2.3
6.2
9.5
Controlled
0.06
0.35
0.94
1.4
cars, tank trucks, and
drums
Fugitive
Secondary
Wastewater treatment
Incineration of residue
or landfill
Total
F
G,H
19.5
40.5
4.3
7.1
-------
VII-3
Table VII-2.
Emission Summary for 1,1,1-Trichloroethane Model Plant,
Ethane Process (29,500 Mg/yr)
Emission
Distillation vent
Storage vents
Intermediate storage
Product storage
Handling — loading of tank
Vent
Designation
(Fig.III-2)
A
B
C
D
VOC Emission Rate (kg/hr)
Uncontrolled
0.7
0.5
1.4
2.1
Controlled
0.014
0.08
0.21
0.30
cars, tank trucks, and
drums
Fugitive
Secondary
Wastewater treatment
Incineration of residue
or landfill
E
F
G,H
19.5
0.004
<0.01
4.3
0.004
<0.01
Total
24.2
4.9
-------
VII-4
B. REFERENCES*
1. S. A. Cogswell, "Ethylene Bichloride," pp. 651.5031A—F and 651.5032A—651.50331
in Chemical Economics Handbook, Stanford Research Institute, Menlo Park, CA
(February 1979).
2. S. A. Cogswell, "C2 Chlorinated Solvents," pp. 632.3000A—F and 632.3001A—
632.3002A in Chemical Economics Handbook, Stanford Research Institute, Menlo
Park, CA (December 1978).
*Usually, when a reference is located at the end of a paragraph, it refers to
the entire paragraph. If another reference relates to certain portions of
that paragraph, that reference number is indicated on the material involved.
When the reference appears on a heading, it refers to all the text covered by
that heading.
-------
A-l
APPENDIX A
PHYSICAL PROTERTIES OF 1,1,1-TRICHLOROETHANE,
PERCHLOROETHYLENE, TRICHLOROETHYLENE, AND VINYLIDENE CHLORIDE
Table A-l. Properties of 1,1,1-Trichloroethane*
Synonyms
Molecular formula
Molecular weight
Physical state
Vapor pressure
Vapor specific gravity
Boiling point
Melting point
Density
Water solubility
Methyl chloroform, a-trichloroethane
C2H3C13
133.41
Liquid
130.86 mm Hg at 24°C
4.55
74.1°C
-30.41°C
1.3390 g/ml at 20°C/4°C
Insoluble
*From: J. Dorigan et^ ,aJL. , "1,1,1-Trichloroe thane," p. AIV-238 in
Scoring of Organic Air Pollutants. Chemistry, Production and
Toxicity of Selected Organic Chemicals (Chemicals 0-Z), MTR-7248,
Rev. 1, Appendix IV, Mitre Corp., McLean, VA (September 1976).
-------
A-2
Table A-2. Properties of Perchloroethylene"
Synonyms
Molecular formula
Molecular weight
Physical state
Vapor pressure
Vapor specific gravity
Boiling point
Melting point
Density
Water solubility
Tetrachloroethylene, carbondichloride (sic*),
ethylene tetrachloride, tetrachloro-
ethene
C2C14
165.82
Liquid
18.47 mm Hg at 25°C
5.83
121.20°C
-19°C
1.6227 g/ml at 20°C/4°C
Insoluble
*From: J. Dorigan et_ al. , "Perchloroethylene," p. AIV-24 in
Scoring of Organic Air Pollutants. Chemistry, Production and
Toxicity of Selected Organic Chemicals (Chemicals O-Z), MTR-7248,
Rev. 1, Appendix IV, Mitre Corp., McLean, VA (September 1976).
-------
A-3
Table A-3. Properties of Trichloroethylene*
Synonyms
Molecular formula
Molecular weight
Physical state
Vapor pressure
Vapor specific gravity
Boiling point
Melting point
Density
Water solubility
Ethylene trichloride , ethinyl tri-
chloride, trichloroethene, acetyl-
ene trichloride
131.39
Liquid
77.5 mm Hg at 25°C
4.53
87 °C
-73°C
1.4642 g/ml at 20°C/4°C
Slightly
*From: J. Dorigan e_t al. , "Trichloroethylene," p. AIV-242 in
Scoring of Organic Air Pollutants. Chemistry, Production and
Toxicity of Selected Organic Chemicals (Chemicals 0-Z), MTR-7248,
Rev, 1, Appendix IV, Mitre Corp., McLean, VA (September 1976).
-------
A-4
Table A-4. Properties of Vinylidene Chloride*
Synonyms 1,1-Dichloroethylene
Molecular formula C H Cl
£ £ £•
Molecular weight 97.0
Physical state Volatile liquid
Vapor pressure 617.14 mm Hg at 20°C
Boiling point 37°C
Melting point -122.53°C
Density 1.213 g/ml at 20°C/4°C
Water solubility Insoluble
*From: J. Dorigan et aJi. , "Vinylidene Chloride,"
p. AIV-290 in Scoring of Organic Air Pollutants.
Chemistry, Production and Toxicity of Selected
Organic Chemicals (Chemicals O-Z), MTR-7248,
Rev. 1, Appendix IV, Mitre Corp., McLean, VA
(September 1976).
-------
B-l
APPENDIX B
AIR-DISPERSION PARAMETERS
Table B-l. Air-Dispersion Parameters for 1 ,1,1-Trichloroethane
(Vinyl Chloride Feed) Model Plant with a Capacity of 136,000 Mg/yr
Source
VOC
Emission
Rate Height
(g/sec) (m)
Discharge
Diameter Temperature
(m) (K)
Flow Discharge
Rate Velocity
(m /sec) (m/sec)
Uncontrolled Emissions
Distillation vent
Storage vents
Intermediate (4)
Intermediate (2)
Product (4)
Handling — loading
tank cars and
tank trucks
Fugitive*
Secondary — waste-
water treatment
0.83 20
0.12 (each) 7.3
0.07 (each) 7.3
0.43 (each) . 9.8
2.63 4
.
5.41
0.0055 1
Controlled
0.1 300
5.7 300
4.1 300
8.8 300
0.5 300
30 300
Emissions
0.026 3.3
Incinerator (dis- 0.016
tillation vent)
Refrigerated vent 0.09
condenser (inter-
mediate storage)
Refrigerated vent 0.65
condenser (prod-
uct storage and
handling)
Fugitive* 1.19
20
20
20
0.1
0.1
750
263
263
0.0016
0.012
0.21
1.50
*Distributed over an area of 150 m X 400 m.
-------
B-2
Table B-2. Atmospheric Dispersion Parameters for 1,1,1-Trichloroethane
(Ethane Feed) Model Plant with a Capacity of 29,500 Mg/yr
Source
VOC
Emission
Rate
(g/sec)
Height
(m)
Diameter
(m)
Discharge
Temperature
(K)
Flow Discharge
Rate Velocity
(m /sec) (m/sec)
Uncontrolled Emissions
Distillation vent 0.19
Storage vents
Intermediate (4) 0.029
Intermediate (2) 0.016
Product (4) 0.10
Handling—loading 0.57
tank cars and
tank trucks
Fugitive* 5.41
Secondary—waste- 0.001
water treatment
20
4.9
2.4
7.3
4
0.1
3.8
3.9
5.5
0.5
30
300
300
300
300
300
0.000018 0.023
300
Incinerator (dis- 0.004
tillation vent)
Refrigerated vent 0.03
condenser (inter-
mediate storage)
Refrigerated vent 0.14
condenser (prod-
uct storage and
handling)
Fugitive* 1-19
Controlled Emissions
20
20 0.1
20
0.1
750
263
263
0.0005 0.067
0.0025 0.32
*Distributed over an area of 150 m X 400 m.
-------
C-l
APPENDIX C
FUGITIVE-EMISSION FACTORS*
The Environmental Protection Agency recently completed an extensive testing
program that resulted in updated fugitive-emission factors for petroleum re-
fineries. Other preliminary test results suggest that fugitive emissions from
sources in chemical plants are comparable to fugitive emissions from correspond-
ing sources in petroleum refineries. Therefore the emission factors established
for refineries are used in this report to estimate fugitive emissions from
organic chemical manufacture. These factors are presented below.
Uncontrolled
Emission Factor
Controlled
Emission Factor*
Source
Pump seals
Light-liquid service
Heavy-liquid service
Pipeline valves
Gas/vapor service
Light-liquid service
Heavy-liquid service
Safety/relief valves
Gas/vapor service
Light-liquid service
Heavy-liquid service
Compressor seals
Flanges
Drains
(kg/hr)
0.12
0.02
0.021
0.010
0.0003
0.16
0.006
0.009
0.44
0.00026
0.032
(kg/hr)
0.03
0.02
0.002
0.003
0.0003
0.061
0.006
0.009
0.11
0.00026
0.019
Based on monthly inspection of selected equipment; no inspection of
heavy-liquid equipment, flanges, or light-liquid relief valves,-
10,000 ppmv VOC concentration at source defines a leak; and 15 days
allowed for correction of leaks.
Light liquid means any liquid more volatile than kerosene.
*Radian Corp., Emission Factors and Frequency of Leak Occurrence for Fittings
in Refinery Process Units, EPA 600/2-79-044 (February 1979).
-------
D-l
APPENDIX D
EXISTING PLANT CONSIDERATIONS
A. GENERAL
Table D-l1—3 summarizes the control devices currently used by producers of
1,1,1-trichloroethane, perchloroethylene, trichloroethylene, and vinylidene
chloride. Information for this report was obtained from a site visit to a man-
ufacturer of these products (a trip report1 is on file at ESED in Durham, NC)
and from responses to requests for information from other manufacturers.
Pertinent information concerning emissions and the corresponding control devices
used by existing plants is given here.
B. 1,1,1-TRICHLOROETHANE
The only significant process emission sources reported by 1,1,1-trichloroethane
manufacturers are the distillation column vents. Emissions are controlled by
scrubbing with water at the Dow Freeport, TX, plant,1 with an estimated VOC
removal efficiency of approximately 90% attained. At the PPG Lake Charles, LA,
plant distillation vent emissions are compressed and recycled to the EDC process,
where the contained VOC is either consumed or is combined with the emissions
from the EDC process and eventually incinerated,2 with an estimated VOC removal
efficiency of greater than 98%. Vulcan at Geismer, LA, reports the use of glycol
pots for controlling this emission source.3 No information was obtained as to
the function or efficiency of these devices.
Refrigerated condensers and refrigerated absorption systems were the predominant
devices reported for controlling storage and handling emissions from 1,1,1-tri-
chloroethane manufacture, as well as from perchloroethylene, trichloroethylene,
and vinylidene chloride production. The VOC removal efficiencies of these devices
were estimated to range from 85 to 90%.
C. PERCHLOROETHYLENE AND TRICHLOROETHYLENE
1. Chlorination Process
Diamond Shamrock uses a chilled-water condenser on its crude drying column and
reports a reduction efficiency of about 80%.4 Ethyl has a refrigerated vent
condenser on its atmospheric distillation columns' vents that reduced the VOC
by more than 80%. In addition the vent gases from the vent condenser are sent
-------
Table D-l. Emission Control Devices or Techniques Currently Used by Producers of
1,1,1-Trichloroethane, Perchloroethane, Trichloroethylene, and Vinylidene Chloride
Emission Source
Product/Process
Producer/Location
Distillation Vents
Other Process Vents Storage and Handling
1,1,1-Trichloroethane/
vinyl chloride
1,1,1-Trichloroethane/
ethane
Perchloroethylene-
trichloroethylene/
chlorination
Perchloroethylene-
trichloroethylene/
oxychlorination
Vinylidene chloride
Dow, Freeport, TX
Water scrubber
PPG, Lake Charles, LA Compressed and trans-
ferred to EDC process;
vents from EDC process
incinerated
c d
Vulcan, Geismar, LA Glycol pot
Dow, Freeport, TX
Diamond Shamrock,
Deer Park, TX
Ethyl Corp.,
Baton Rouge, LA
No record
No record
Refrigerated condenser;
vented VOC fed to
other processes
PPG, Lake Charles, LA Water scrubbers
Dow, Plaquemine, LA
Dow, Freeport, TX
Currently uncontrolled;
to be recycled and
ultimately incinerated
Water scrubber
Water scrubbers
Chilled water
condenser
No record
Thermal oxidizer
Thermal oxidizer
Refrigerated vent
condensers
Refrigerated ab-
sorption system
No record
Refrigerated con-
densers; water
scrubbers
Refrigerated vent
condensers
No record
No record
Refrigerated vent
condensers
g
Refrigerated condenser Refrigerated vent
condensers
^ d e
"See ref 3. No information on function or efficiency of this device. Crude drying column
aSee ref 1. bSee ref 2.
vent. HC1 absorption system vent and drying system vent. yReactor vent.
-------
D-3
to another process.5 Diamond Shamrock has several refrigerated vent condensers
on in-process and product storage tanks and reports removal efficiencies of
from 50 to 99%.4
Dow reports an efficiency of 85% for refrigerated condensers on its product
storage tanks.6 Dow uses water scrubbers to control the emissions from two
process vents although data on the removal efficiency or type of treatment of
the wastewater are not available.1 Water scrubbers on two raw-material tanks
are reported to have efficiencies of 90%. Regulators on four in-process pressure
tanks have a reported efficiency of 70%.6
2. Oxychlorination Process2
A thermal oxidizer, one of two that burn liquid and gaseous wastes from the
entire chlorinated hydrocarbon comples, is used by PPG to control the emissions
from the hydrogen chloride absorption system vent (A, Fig. III-4) and from the
drying still vent (B, Fig. III-4). The removal efficiency is greater than 99%
and the operating conditions are 1425°C in the combustion chamber with a residence
time of 0.4 sec. Water scrubbers are used by PPG to control the emissions from
the distillation columns vents (C, Fig. III-4) and the product neutralizers
vents (D, Fig. III-4) by removing hydrogen chloride and small amounts of organics.
D. VINYLIDENE CHLORIDE
At the Dow Plaquemine, LA, plant VOC emissions from the reactor vent are con-
trolled by incineration, with an estimated reduction of about 98%.7 At the Dow
Freeport, TX, plant this source is controlled by a refrigerated condenser, with
an estimated VOC removal efficiency of 93%.1 Emissions of VOC from the distil-
lation vent are controlled by an aqueous scrubber at the Dow Freeport, TX, plant,
with an estimated reduction in VOC emission of approximately 90%.1 Emissions
of VOC from the distillation vent at the Dow Plaquemine, LA, plant are currently
uncontrolled; however, changes that are planned include routing the vent to the
steam stripper and recycling the stripped gas to the dehydrochlorination reactor,
where the contained noncondensible gases will be included with the current reactor
vent stream and routed to the incinerator.7 This should provide a VOC removal
efficiency of about 98% for the distillation vent stream.
-------
D-4
Data are not currently available on the control devices and controlled emis-
sions for PPG's Lake Charles, LA, vinylidene chloride plant. Dow and PPG are
currently the only domestic producers of vinylidene chloride.
E. RETROFITTING CONTROLS
The primary difficulty associated with retrofitting may be in finding space to
fit the control device into the existing plant layout. Because of the costs
associated with this difficulty it may be appreciably more expensive to retrofit
emission control systems in existing paints than to install a control system
during construction of a new plant.
-------
D-5
F. REFERENCES*
1. R. L. Standifer, IT Enviroscience, Inc., Trip Report for Visit to Dow Chemical
USA, Freeport, TX, Nov. 9, 1977 (on file at EPA, ESED, Research Triangle Park,
NC).
2. F. C. Dehn, PPG Industries, Inc., letter dated Mar. 14, 1979, to EPA in response
to request for information on the air emissions from the 1,1,1-trichloroethane,
perchloroethylene, and trichloroethylene processes at Lake Charles, LA.
3. T. A. Leonard, Vulcan Materials Co., letter dated Mar. 8, 1979, to EPA with
information on air emissions from the 1,1,1-trichloroethane plant at Geismar,
LA, in response to EPA request.
4. J. B. Worthington, Diamond Shamrock, letter dated Jan. 16, 1979, to EPA with
information on air emissions from the perchloroethylene plant at Deer Park, TX,
in response to EPA request.
5. W. C. Strader, Ethyl Corporation, letter dated Nov. 28, 1978, to EPA with
information on air emissions from the perchloroethylene and trichloroethylene
plant at Baton Rouge, LA, in response to EPA request.
6. R. S. McKneely, Dow Chemical, Freeport, TX, Texas Air Control Board Emissions
Inventory Questionnaire for 1975.
7. J. Beale, Dow Chemical, letter dated Oct. 25, 1978, to EPA with information on
air emissions from the cinylidene chloride plant at Plaquemine, LA, in response
to EPA request.
*Usually, when a reference is located at the end of a paragraph, it refers to
the entire paragraph. If another reference relates to certain portions of
that paragraph, that reference number is indicated on the material involved.
When the reference appears on a heading, it refers to all the text covered by
that heading.
-------
5-i
REPORT 5
CHLOROMETHANES BY
METHANE CHLORINATION PROCESS
F. D. Hobbs
C. W. Stuewe
IT Enviroscience
9041 Executive Park Drive
Knoxville, Tennessee 37923
Prepared for
Emission Standards and Engineering Division
Office of Air Quality Planning and Standards
ENVIRONMENTAL PROTECTION AGENCY
Research Triangle Park, North Carolina
February 1981
This report contains certain information which has been extracted from the
Chemical Economics Handbook, Stanford Research Institute. Wherever used, it
has been so noted. The proprietary data rights which reside with Stanford
Research Institute must be recognized with any use of this material.
D26F
K
*
-------
5-iii
CONTENTS OF REPORT 5
Page
I. ABBREVIATIONS AND CONVERSION FACTORS I_1
II. INDUSTRY DESCRIPTION II-l
A. Reason for Selection II-l
B. Methyl Chloride II-l
C. Methylene Chloride II-3
D. Chloroform II-6
E. Carbon Tetrachloride II-9
F. References 11-16
III. PROCESS DESCRIPTION III-l
A. Introduction III-l
B. Methane Chlorination Model Process III-l
C. Process Variations III-4
D. References III-5
IV. EMISSIONS IV-1
A. Model Plant IV-1
B. Sources and Emissions IV-2
C. References IV-8
V. APPLICABLE CONTROL SYSTEMS V-l
A. Emission Controls for Model Plant V-l
B. References V-5
VI. IMPACT ANALYSIS VI-1
A. Environmental and Energy Impact VI-1
B. Control Cost Impact VI-3
C. References VI-7
VII. SUMMARY VII-1
-------
5-v
APPENDICES OF REPORT 5
Page
A. PHYSICAL PROPERTIES OF CHLOROMETHANE COMPOUNDS A-l
B. AIR-DISPERSION PARAMETERS B_!
C. FUGITIVE-EMISSION FACTORS c_!
D. EXISTING PLANT CONSIDERATIONS D-l
E. COST ESTIMATE SAMPLE CALCULATIONS E-l
-------
5-vii
TABLES OF REPORT 5
Number
Page
II-l Methyl Chloride Usage and Growth jj_2
II-2 Methyl Chloride Capacity II_4
II-3 Methylene Chloride Usage and Growth U_7
II-4 Methylene Chloride Capacity ZI_7
II-5 Chloroform Usage II-10
II-6 Chloroform Capacity 11-10
II-7 Carbon Tetrachloride Usage 11-13
II-8 Carbon Tetrachloride Capacity 11-14
IV-1 Uncontrolled Emissions IV_3
IV-2 Characteristics of Emissions from Recycled-Methane Inert-Gas iv-4
Purge Vent
IV-3 Storage Requirements for Model Plant Iv_6
V-l Controlled VOC Emissions v_3
VI-1 Environmental Impact of Controlled Emissions VI-2
VI-2 Cost Factors
V i "" J
A-l Physical Properties
A.™ j.
B-l Air-Dispersion Parameters
B—1
-------
FIGURES OF REPORT b
Number
Page
II-l Locations of Plants Manufacturing Methyl Chloride II-5
II-2 Locations of Plants Manufacturing Methylene Chloride II-8
II-3 Locations of Plants Manufacturing Chloroform 11-11
II-4 Locations of Plants Manufacturing Carbon Tetrachloride 11-15
III-l Process Flow Diagram for Methane Chlorinatior I LI-2
E-l Precision of Capital Estimates E-2
-------
1-1
ABBREVIATIONS AND CONVERSION FACTORS
EPA policy is to express all measurements used in agency documents in metric
units. Listed below are the International System of Units (SI) abbreviations
and conversion factors for this report.
To Convert From
Pascal (Pa)
Joule (J)
Degree Celsius (°C)
Meter (m)
Cubic meter (m3)
Cubic meter (m3)
Cubic meter (m3)
Cubic meter/second
(m3/s)
Watt (W)
Meter (m)
Pascal (Pa)
Kilogram (kg)
Joule (J)
To
Atmosphere (760 mm Hg)
British thermal unit (Btu)
Degree Fahrenheit (°F)
Feet (ft)
Cubic feet (ft3)
Barrel (oil) (bbl)
Gallon (U.S. liquid) (gal)
Gallon (U.S. liquid)/min
(gpm)
Horsepower (electric) (hp)
Inch (in.)
Pound-force/inch2 (psi)
Pound-mass (Ib)
Watt-hour (Wh)
Multiply By
9.870 X 10"6
9.480 X 10~4
(°C X 9/5) + 32
3.28
3.531 X 101
6.290
2.643 X 102
1.585 X 104
1.340 X 10"3
3.937 X 101
1.450 X 10~4
2.205
2.778 X 10~4
Standard Conditions
68°F = 20°C
1 atmosphere = 101,325 Pascals
PREFIXES
Prefix
T
G
M
k
m
Symbol
tera
giga
mega
kilo
milli
micro
Multiplication
Factor
1012
109
106
103
10'3
10"6
Example
1
1
1
1
1
1
Tg =
Gg =
Mg =
km =
mV =
Mg =
1
1
1
1
1
1
X
X
X
X
X
X
1012
109
10s
103
10"3
10~6
grams
grams
grams
meters
volt
gram
-------
II-l
II. INDUSTRY DESCRIPTION
A. REASON FOR SELECTION
Four volatile organic compounds (VOC) -- methyl chloride, methylene chloride,
chloroform, and carbon tetrachloride -- comprise the group commonly referred to
as "chloromethanes." These compounds were selected for study because preliminary
estimates indicated that their production causes relatively high VOC emissions.
There are several processes by which chloromethanes are produced either as co-pro-
ducts or individually: (1) the methanol hydrochlorination and methyl chloride
chlorination processes, which are described in a similar report;1 (2) methane
chlorination, which yields all four chloromethanes as co-products and is the
process described in this report; (3) hydrocarbon chlorinolysis, which yields
carbon tetrachloride and perchloroethylene as co-products and which also is
described in a similar report;2 and (4) carbon disulfide chlorination, which
produces carbon tetrachloride.
B. METHYL CHLORIDE
1. General Description
Methyl chloride is a gas at ambient conditions but is handled commercially in
liquid form (see Appendix A for pertinent physical properties). It is produced
by methanol hydrochlorination or by methane chlorination. Emissions from its
manufacture include all the chloromethanes.
2. Usage and Growth
The end uses and expected growth rates of methyl chloride are given in Table II-l.
The predominant use of methyl chloride is as an intermediate in the production
of silicones and in the production of tetramethyllead, a gasoline additive.
The expected increase in usage as an intermediate for silicone production combined
with decreases in usage as an intermediate for tetramethyllead production, which
is being restricted as a gasoline additive,3 will result in nearly static produc-
tion patterns for methyl chloride. Large amounts of the methyl chloride manu-
factured are not recovered as product but are further chlorinated to produce
methylene chloride and chloroform. This usage is not included in the production
and end-use statistics,4
-------
II-2
Table II-l. Methyl Chloride Usage and Growth
End Useb
Silicone intermediate
Tetramethyllead intermediate
Butyl rubber (catalyst solvent)
Miscellaneous
Production (%)
1977
63
18
8
11
Average Annual
Growth
m
10-^-12
-25
3.5
NA°
aSee refs 3 and 4.
bAmounts consumed as intermediates in continuous production of other chloro-
methanes not included.
GNot available.
-------
II-3
The current domestic methyl chloride production capacity is reported to be about
283,000 Mg/yr,4 with the 1979 production utilizing only about 72% of that capa-
city.5 The annual growth in methyl chloride production is expected to remain
static or at best to increase by 5% annually. Even at the 5% annual growth rate,
production would reach only about 83% of capacity by 1982. There are no known
plans for new methyl chloride production facilities.
3. Domestic Producers
There are ten domestic producers of methyl chloride operating 13 plants. Table II-2
lists the producers, locations, capacities, and processes in use; Fig. II-l shows
the plant locations. The Dow plant at Freeport, TX, produces methyl chloride by
chlorination of methane. Allied uses hydrochlorination of methanol for about 95%
of its production and uses chlorination of methane for the remaining production.6
Vulcan operates two chloromethanes facilities at Wichita, KS. One is a recently
constructed facility based completely on hydrochlorination of methanol, and the
other (older) facility uses both hydrochlorination of methanol and chlorination
of methane. Hydrochlorination of methanol accounts for about 90% of the total
combined production.7 All other manufacturers produce methyl chloride by hydro-
chlorination of methanol. The two Vulcan plants use all the methyl chloride they
produce as an intermediate and therefore report no methyl chloride capacity as
such. Allied, Diamond Shamrock, Dow, and Stauffer produce the higher chloromethanes
in addition to methyl chloride. The ratios of co-products produced at these
plants are flexible because the methyl chloride may be separated as product or
may be further chlorinated to produce methylene chloride and chloroform. Con-
tinental, Dow Corning, Ethyl, General Electric, and Union Carbide produce only
methyl chloride.
C. METHYLENE CHLORIDE
1. General Description
Methylene chloride is a heavy, volatile liquid at ambient conditions (see
Appendix A for pertinent physical properties) and is produced by chlorination of
either methyl chloride or methane. Emissions from its manufacture include all
the chloromethanes.
-------
II-4
Table II-2. Methyl Chloride Capacity
Plant
1977 Capacity
(X 103 Mg)
Process
Allied, Moundsville, WV
11
Methanol hydrochlorination and
methane chlorination
Continental, West lake, LA
Diamond Shamrock, Belle, WV
Dow, Freeport, TX
Dow, Plaquemine, LA
Dow Corning, Carrolton, KY
Dow Corning, Midland, MI
Ethyl, Baton Rouge, LA
General Electric, Water ford, NY
Stauffer, Louisville, KY
Union Carbide , Institute , WV
Vulcan, Geismar, LA
Vulcan, Wichita, KS
Total
46
32b
68b
9
7
46
23
7b
23
c
c
283
Methanol hydrochlorination
Methanol hydrochlorination
Methane chlorination
Methanol hydrochlorination
Methanol hydrochlorination
Methanol hydrochlorination
Methanol hydrochlorination
Methanol hydrochlorination
Methanol hydrochlorination
Methanol hydrochlorination
Methanol hydrochlorination
Methanol hydrochorination and
methane chlorination
See ref 4.
Production ratios vary with amount of methyl chloride separated as product and
amount chlorinated for methylene chloride and chloroform manufacture.
CA11 methyl chloride is chlorinated to methylene chloride and chloroform.
-------
II-5
1. Allied, Moundsville, WV
2. Continental, Westlake, LA
3. Diamond Shamrock, Belle, WV
4. Dow, Freeport, TX
5. Dow, Palquemine, LA
6. Dow Corning, Carrolton, KY
7. Dow Corning, Midland, MI
8. Ethyl, Baton Rouge, LA
9. General Electric, Waterford, NY
10. Stauffer, Louisville, KY
11. Union Carbide, Institute, WV
12. Vulcan, Geismar, LA
13. Vulcan, Wichita, KS
Fig. Il-l. Locations of Plants Manufacturing Methyl Chloride
-------
II-6
2. Usage and Growth
Table II-3 gives the end uses and expected production growth rates of methylene
chloride, which is used predominantly as a solvent. Its nonflammability and low
acute toxicity contribute to its popularity as a paint remover.
The current methylene chloride production capacity is about 378,000 Mg/yr,4 with
about 75% of that capacity being utilized in 1979.5 Based on an estimated 11%
annual growth in methylene chloride consumption,3 the demand will nearly equal
the current capacity by 1982.
3. Domestic Producers
In 1979 five domestic producers of methylene chloride were operating seven plants.
Table II-4 lists the producers, locations, capacities, and processes being used;
Fig. II-2 shows the plant locations. The Dow Chemical plant at Freeport, TX,
representing 24% of the total domestic capacity, was the only plant using methane
chlorination exclusively for methylene chloride production. The Vulcan plant at
Wichita, KS, and the Allied plant have both methane chlorination and methyl
chloride chlorination process capabilities. Approximately 5% of Allied1s capacity
and 10% of Vulcan's capacity are based on the methane chlorination process.6'7
All other plants use methyl chloride chlorination. All producers manufacture
chloromethane co-products, and production ratios vary, depending on the desired
end products.
Vulcan's new 63,500-Mg/yr chloromethane plant at Wichita, KS, using the methyl
chloride chlorination process, provided additional methylene chloride capacity of
36,300 Mg/yr. Dow reportedly planned to expand its methylene chloride production
capacity by late 1979.4
D. CHLOROFORM
1. General Description
Chloroform is a heavy, volatile liquid at ambient conditions (see Appendix A for
pertinent physical properties) and is made by chlorination of methyl chloride or
methane. Emissions from chloroform manufacture include all the chloromethanes.
-------
11-7
Table II-3. Methylene Chloride Usage and Growth3'
End Use
1977 Production (%)
Paint remover
Solvent degreasing
Plastics process
Exports
Aerosol
Miscellaneous
30
20
9
18
19
4
See ref 4.
Data on growth rates not available.
Table II-4. Methylene Chloride Capacity5
Plant
Allied, Moundsville, WV
Diamond Shamrock, Belle, WV
Dow, Freeport, TX
Dow, Plaquemine, LA
Stauffer, Louisville, KY
Vulcan, Geismar, LA
Vulcan, Wichita, KS
Total
1977 Capacity13
(X 103 Mg)
23
50
92
88
28
37
60
378
Process
Methyl chloride chlorination and
methane chlorination
Methyl chloride chlorination
Methane chlorination
Methyl chloride chlorination
Methyl chloride chlorination
Methyl chloride chlorination
Methyl chloride chlorination and
methane chlorination
See ref 4.
Other chloromethanes are manufactured as co
dividual products vary.
-products, and capacities for in-
-------
II-8
1. Allied, Moundsville, WV
2. Diamond Shamrock, Belle, WV
3. Dow, Freeport, Tf.
4. Dow, Plaquemine, LA
5. Stauffer, Louisville, KY
6. Vulcan, Geismar, LA
7. Vulcan, Wichita, KS
Fig. II-2. Locations of Plants Manufacturing Methylene Chloride
-------
II-9
2. Usage and Growth
As is shown in Table II-5, the predominant end use of chloroform is as an inter-
mediate in the manufacture of chlorodifluoromethane. Chlorodifluoromethane can
be used as a refrigerant, a solvent, or a propellant or in the manufacture of
fluororesins, but its main use is as a refrigerant. A ban on fluorocarbon pro-
pellants would not significantly affect its production rate.4
The current domestic chloroform production capacity is 237,000 Mg/yr,4 with
1979 production utilizing about 67% of that capacity.5 Based on an estimated 8%
annual growth in chloroform consumption, production would reach 84% of current
capacity by 1982.
3. Domestic Producers
In 1979 five domestic producers were operating seven chloroform-producing plants.
Table II-6 lists the producers, locations, capacities, and processes being used;
Fig. II-3 shows the plant locations. The Dow Chemical plant at Freeport, TX, is
the only facility using methane chlorination exclusively for chloroform produc-
tion. The capacity of this plant is about 20% of the total domestic capacity.
The Allied plant, as well as the Vulcan plant at Wichita, KS, has both methane
chlorination and methyl chloride chlorination process capabilities. Approxi-
mately 5% of Allied1s capacity and 10% of Vulcan's capacity are based on
methane chlorination.6'7 All other plants use methyl chloride chlorination
exclusively for chloroform production. All producers manufacture chloromethane
co-products, and production ratios vary, depending on the desired end products.
Vulcan's new 63,500-Mg/yr chloromethanes plant at Wichita, KS, which was com-
pleted in 1977, provided an additional capacity of 27,200 Mg/yr. Dow scheduled
an increase in capacity at Freeport, TX, which was to have been brought on-stream
late in 1979.4
E. CARBON TETRACHLORIDE
1. General Description
Carbon tetrachloride is a heavy, volatile liquid at ambient conditions (see
Appendix A for pertinent physical properties), and is produced by methane chlori-
nation, chlorinolysis of mixed hydrocarbons, or carbon disulfide chlorination.
It also is a by-product in the methyl chloride chlorination process.
-------
11-10
Table II-5. Chloroform Usage
a,b
1974
Production
Chlorodifluoromethane
Refrigerant, solvent, propellant
Exports
Miscellaneous
91
7
2
See ref 4.
"Data on growth rates not available.
Table II-6. Chloroform Capacity'
Plant
Allied, Moundsville, WV
Diamond Shamrock, Belle, WV
Dow, Freeport, TX
Dow, Plaquemine, LA
Stauffer, Louisville, KY
Vulcan, Geismar, LA
Vulcan, Wichita, KS
Total
1979 Capacity
(X 10 3 Mg)
14
18
46
46
34
28
51
237
Process
Methyl chloride chlorination
and methane chlorination
Methyl chloride chlorination
Methane chlorination
Methyl chloride chlorination
Methyl chloride chlorination
Methyl chloride chlorination
Methyl chloride chlorination
and methane chlorination
aSee ref 4.
bOther chloromethanes are manufactured as co-products, and capacities for
individual products vary.
-------
11-11
1. Allied, Moundsville, WV
2. Diamond Shamrock, Belle, Wv
3. Dow, Freeport, TX
4. Dow, Plaquemine, LA
5. Stauffer, Louisville, KY
6. Vulcan, Geismar, LA
7. Vulcan, Wichita, KS
Fig. II-3. Locations of Plants Manufacturing Chloroform
-------
11-12
Emissions from carbon tetrachloride manufactured by the methane chlorination
process include all the chloromethanes.
2. Usage and Growth
Table II-7 gives the end uses of carbon tetrachloride.5 About 90% of carbon
tetrachloride consumption in recent years has been as an intermediate in the
production of trichlorofluoromethane and dichlorodifluoromethane. These two
compounds have been the subject of much controversy concerning their potential
contribution to the depletion of stratospheric ozone. As a result the consump-
tion of carbon tetrachloride between 1974 and 1976 dropped 27%.8 (The EPA pro-
mulgated regulations controlling fully halogenated chlorofluoroalkanes on March
17, 1978.9) The current domestic carbon tetrachloride production capacity is
555,000 Mg/yr, with 1979 production10 utilizing only about 57% of that capacity.
Production may decline as much as 10% annually. There are no known plans to
increase carbon tetrachloride capacity.
3. Domestic Producers
In 1979 six domestic producers of carbon tetrachloride were operating eleven
plants. Table II-8 lists the producers, locations, capacities, and manufactur-
ing processes; Fig. II-4 shows the plant locations. Dow at Freeport, TX,
Pittsburg, CA, and Plaquemine, LA; Stauffer at Louisville, KY; and Vulcan at
Geismar, LA, and Wichita, KS, all operate plants based on chlorinolysis of mixed
hydrocarbon feed streams and produce perchloroethylene as a co-product. Allied;
Dow at Freeport, TX, and Pittsburg, CA; and Vulcan at Wichita, KS, are reported8
to operate plants using the methane chlorination process, which produces carbon
tetrachloride as one of the co-products. Some of these producers may be using
methane feed in the chlorinolysis process. Only a small portion of the Allied
and Vulcan capacity is based on methane chlorination.6'7 Stauffer at LeMoyne,
AL, and Niagara Falls, NY, operates carbon tetrachloride production plants that
use the carbon disulfide chlorination process. FMC operated a carbon disulfide
chlorination process at South Charleston, WV, that was shut down in 1979. No
information on capacity or raw material is available on the Inland Chemical
Corporation plant at Manati, PR. Capacities for all plants other than those
using the carbon disulfide chlorination process are flexible since reaction
conditions can be adjusted to vary the yields of carbon tetrachloride and its
co-products.
-------
11-13
Table II-7. Carbon Tetrachloride Usage&/
1977
End Use Production (%)
Trichlorofluoromethane 33.8
Dichlorodifluoromethane 55
Miscellaneous 11.2
a
See ref 5.
b
Data on growth rates not available.
-------
11-14
Table II-8. Carbon Tetrachloride Capacity
Plant
1977
Capacity
(X 103 Mg)
Process
Allied, Moundsville, WV
Dow, Freeport, TX
Dow, Pittsburg, CA
Dow, Plaquemine, LA
Du Pont, Corpus Christi, TX
Inland, Manati, PR
Stauffer, Le Moyne, AL
Stauffer, Louisville, KY
Stauffer, Niagara Falls, NY
Vulcan, Geismar, LA
Vulcan, Wichita, KS
Total
61
36
57
154
c
91
16
68
41
27
555
Methyl chloride chlorination and
methane chlorination
Methane chlorination and chlorin-
olysis of mixed hydrocarbon feed
with perchloroethylene co-product
Methane chlorination and chlorin-
olysis of mixed hydrocarbon feed
with perchloroethylene co-product
Chlorinolysis of mixed hydrocarbon
feed with perchloroethylene co-
product
Chlorinolysis of mixed hydrocarbon
feed with perchloroethylene co-
product
Carbon disulfide chlorination
Methane chlorination and Chlorin-
olysis of mixed hydrocarbon feed
with perchloroethylene co-product
Carbon disulfide chlorination
Chlorinolysis of mixed hydrocarbon
feed with perchloroethylene co-
product
Methyl chloride chlorination, methane
chlorination, and Chlorinolysis of
mixed hydrocarbon feed with per-
chloroethylene co-product
See ref 8.
Production ratios are flexible, especially when co-products are involved.
'Not available.
-------
11-15
(1)
(2)
(3)
(4)
(5)
(6)
(7)
(8)
(9)
(10)
(11)
Allied Chemical Corp., Moundsville, WV
Dow Chemical Co.
Dow Chemical Co.
Dow Chemical Co.
Dupont Co., Inc.
Freeport, TX
Pittsburg, CA
P1 aquemi ne,, LA
Corpus Christi, TX
Inland Chemical Corp., Manti, PR
Stauffer Chemical Co., Le Moyne, AL
Stauffer Chemical Co., Louisville, KY
Stauffer Chemical Co., Niagara Falls,
Vulcan Materials Co., Geismar, LA
Vulcan Materials Co., Wichita, KS
NY
Fig. II-4. Locations of Plants Manufacturing Carbon Tetrachloride
-------
11-16
F. REFERENCES*
1. F. D. Hobbs and C. W. Stuewe, IT Enviroscience, Inc., Chloromethanes Manufac-
tured by Methanol Hydrochlorination and Methyl Chloride Chlorination Processes,
(November 1980) (EPA/ESED report, Research Triangle Park, NC).
2. F. D. Hobbs and C. W. Stuewe, IT Enviroscience, Inc., Carbon Tetrachloride
and Perchlorethylene by the Hydrocarbon Chlorinolysis Process (September 1980)
(EPA/ESED report, Research Triangle Park, NC).
3. A. D. Obshire et al. , "CEH Marketing Research Report on Methanol," pp. 674.50231—
674.5033S in Chemical Economics Handbook, Stanford Research Institute, Menlo
Park, CA (June 1980).
4. T. F. Killilea, "CEH Product Review on Chlorinated Methanes," pp. 625.2030A—
635.2031G in Chemical Economics Handbook, Stanford Research Institute, Menlo
Park, CA (April 1979).
5. "Chlorinated Methanes," p. 244 in Chemical Economics Handbook, Manual of
Current Indicators—Supplemental Data, Chemical Information Services, Stanford
Research Institute, Menlo Park, CA (August 1980).
6. Personal communication between F. D. Hobbs, IT Enviroscience, Inc., and D. Denoon,
Allied Chemical, Moundsville, WV, July 25, 1978.
7. Personal communication between F. D. Hobbs, IT Enviroscience, Inc., and
T. A. Robinson, Vulcan Materials Co., Wichita, KS, July 28, 1978.
8. E. M. Klapproth, "Carbon Tetrachloride—Salient Statistics," pp 635.2030A—E
in Chemical Economics Handbook, Stanford Research Institute, Menlo Park, CA
(April 1976).
9. Environmental Protection Agency, "Fully Halogenated Chlorofluoroalkanes,"
Federal Register, Vol 43, Part II, p 11318 (Mar. 17, 1978).
10. "C2 Chlorinated Solvents," p 228 in Chemical Economics Handbook, Manual of
Current Indicators—Supplemental Data, Chemical Information Services,
Stanford Research Institute, Menlo Park, CA (June 1980).
^Usually, when a reference is located at the end of a paragraph, it refers to
the entire paragraph. If another reference relates to certain portions of
that paragraph, that reference number is indicated on the material involved.
When the reference appears on a heading, it refers to all the text covered by
that heading.
-------
III-l
III. PROCESS DESCRIPTION
A. INTRODUCTION
Methane can be chlorinated thermally, photochemically, or catalytically, with
thermal chlorination being the most important method.1 Methyl chloride, methylene
chloride, chloroform, and carbon tetrachloride are produced in this process by
the following reactions:
CH4 + C12 > CH3C1 + HC1
(methane) (chlorine) (methyl chloride) (hydrogen chloride)
CH3C1 + C12 > CH2C12 + HC1
(methyl chloride) (chlorine) (methylene chloride) (hydrogen chloride)
CH2C12 + C12 *• CHC13 + HC1
(methylene chloride) (chlorine) (chloroform) (hydrogen chloride)
CHC13 + C12 > CC14 + HC1
(chloroform) (chlorine) (carbon tetrachloride) (hydrogen chloride)
B. METHANE CHLORINATION MODEL PROCESS
A typical continuous process flow diagram for the basic process is shown in
Fig. III-l.
Methane (Stream 1) is mixed with chlorine (Stream 2); then the mixture is pre-
heated before it is fed to the chlorination reactor, which is operated at a
temperature of about 400°C1 and a pressure of about 200,000 Pa.2 Nearly 100%
chlorine conversion and 65% methane conversion are typical with product yields
of about 58.5% methyl chloride, 29.3% methylene chloride, 9.7% chloroform and
2.3% carbon tetrachloride.3 (Methyl chloride can be recycled to the reactor
after separation to enhance yields of the other chloromethanes.) Gases exiting
the reactor (Stream 3) are partly condensed and then scrubbed with chilled chloro-
methanes from the process to absorb most of the chloromethanes from unreacted
methane and by-product hydrogen chloride. The unreacted methane and by-product
hyrogen chloride from the absorber (Stream 4) are fed serially to a hydrogen
chloride absorber, caustic scrubber, and drying column, with the purified methane
(Stream 5) being recycled to the chlorination reactor.
-------
H
H
H
Fig. III-l. Process Flow Diagram for Manufacture of
Chloromethanes by Methane Chlorination Process
-------
III-3
Condensed material from the separator and liquid effluent from the absorber are
combined (Stream 6) and fed to a stripper. Overheads from the stripper, which
include hydrogen chloride, methyl chloride, and some of the higher boiling chloro-
methanes (Stream 7), are fed to a water scrubber, where most of the hydrogen
chloride is removed as weak hydrochloric acid (Stream 8). The overheads are then
scrubbed with dilute sodium hydroxide solution to remove residual hydrogen chloride.
Water is then removed from the crude chloromethanes in a drying column.
The crude chloromethanes from the drying column (Stream 9) are compressed, condensed,
and fed to a methyl chloride distillation column. Methyl chloride from the distil-
lation column can be recycled back to the chlorination reactor (Stream 10) or be
condensed and then transferred to storage and loading as product (Stream 11).
Crude methylene chloride, chloroform, and carbon tetrachloride from the stripper
(Stream 12) are neutralized, dried, and combined with bottoms from the methyl
chloride distillation column (Stream 13) in a crude storage tank. The crude
chloromethanes (Stream 14) pass to a methylene chloride distillation column.
Methylene chloride from the overheads (Stream 15) is condensed and fed to day
storage tanks, where inhibitors may be added for stabilization. Product methylene
chloride is transferred to product storage and loading. Bottoms from the methylene
chloride distillation column (Stream 16) are fed to a chloroform distillation
column, with chloroform overheads (Stream 17) being condensed and fed to day
storage tanks, where inhibitors may be added for stabilization. Product chloro-
form is transferred to storage and loading. Bottoms from the chloroform distil-
lation column (Stream 18) are fed to a carbon tetrachloride distillation column,
with carbon tetrachloride overheads (Stream 19) being condensed and fed to day
storage tanks, where inhibitors may be added for stabilization. Product carbon
tetrachloride is transferred to storage and loading. Bottoms from the carbon
tetrachloride distillation column are incinerated.
Vented gases from the four distillation columns could be recycled to the absorber,
as is indicated in Fig. III-l.
Process emissions from the model plant result from venting of the inert gases
from the recycle methane stream (Vent A, Fig. III-l), from regeneration of the
methane recycle stream drying bed (Vent B, Fig. III-l), and from emergency vent-
ing of the distillation-area inert gases (Vent C, Fig. III-l).
-------
III-4
Fugitive emissions can occur when leaks develop in valves, pump seals, and other
equipment. Corrosion could be caused by the hydrogen chloride and chlorine in
the process if careful attention is not given to selection of equipment and
materials of construction.
Emissions result from the storage of intermediates and products and from the
handling of products.
Potential sources of secondary emissions (K on Fig. III-l) are aqueous discharges
from the three caustic scrubbers, the sulfuric acid drying column, and the dryer.
Another potential source is the incineration of heavies from carbon tetrachloride
distillation.
C. PROCESS VARIATIONS
Inert gases entering the process must be purged, causing losses of VOC. Varia-
tions in purity of feed materials therefore will have considerable impact on
process emissions.
Variation in reaction conditions and in amounts of methyl chloride recycled to
the chlorination reactor changes product yield ratios and therefore changes
relative amounts of methylene chloride, chloroform, and carbon tetrachloride
emitted during storage and loading.
-------
III-5
D. REFERENCES*
1- D. W. F. Hardie, "Chlorocarbons and Chlorohydrocarbons," pp. 105--106 in Kirk-Othmer
Encyclopedia of Chemical Technology. Vol. 5, 2d ed., edited by A. Standen et al.,
Wiley-Interscience, New York, 1964.
2. Monsanto Research Corp., Dayton, Ohio, and Research Triangle Institute, Research
Triangle Park, NC, Chapter 6. The Industrial Organic Chemicals Industry, Part I
p. 6-405 (nd).
3. F. A. Lowenheim and M. K. Moran, "Methyl Chloride -- Methylene Dichloride," pp. 530--.c
in Faith, Keyes, and Clark's Industrial Chemicals, 4th ed., Wiley-Interscience, New
York, 1975.
*A reference located at the end of a paragraph usually refers to the entire paragraph.
If another reference relates to certain portions of the paragraph, the reference number
is indicated on the material involved. When the reference appears on a heading, it
refers to all the text covered by that heading.
-------
IV-1
IV. EMISSIONS
Emissions in this report are usually identified in terms of volatile organic
compounds (VOC). VOC are currently considered by the EPA to be those of a large
group of organic chemicals, most of which, when emitted to the atmosphere partici-
pate in photochemical reactions producting ozone. A relatively small number of
organic chemicals have low or negligible photochemical reactivity. However,
many of these organic chemicals are of concern and may be subject to regulation
by EPA under Sections 111 or 112 of the Clean Air Act since there are associated
health or welfare impacts other than those related to ozone formation. It should
be noted that, although methylene chloride is included in VOC emission totals in
this report, it does not, based on current research data, participate in ozone-
forming reactions to an appreciable extent.
MODEL PLANT*
The total chloromethane capacity for the model plant was selected to be 200,000 Mg/yr.
This capacity was selected because the only domestic facility based completely
on the chlorination of methane, the Dow plant at Freeport, TX, is reported to
have a capacity of about 200,000 Mg/yr. The percentages of total capacity for
individual products were selected to be 20% methyl chloride, 45% methylene chloride,
25% chloroform, and 10% carbon tetrachloride. This product mix requires that
methyl chloride be recycled for additional chlorination. About 171,000 Mg of
by-product hydrogen chloride is generated per year for this product mix. Typical
storage of raw materials, intermediates, and products was selected according to
these percentages of individual products. The model plant was assumed to operate
8760 hr annually.**
The model methane chlorination process shown in Fig. III-l fits today's engineer-
ing and manufacturing technology. The number of valves, pumps, and compressors
is typical for a plant of this type. Characteristics of the model plant important
to air dispersion are shown in Appendix B.
*See page 1-2 for a discussion of model plants.
**Process downtime is normally expected to range from 5 to 15%. If the hourly
rate remains constant the annual production and annual VOC emissions will be
correspondingly reduced. Control devices will usually operate on the same
cycle as the process. From the standpoint of cost-effectiveness calculations
the error introduced by assuming continuous operation is negligible.
-------
IV-2
B. SOURCES AND EMISSIONS
The process emissions for the methane chlorination process described in this
report are based on the emissions reported1 in response to EPA's requests for
information, on the emission inventory questionnaire filed by Dow with the
State of Texas, and comments furnished in response to the draft of this
report. .
Sources and emission rates for the methane chlorination process for the product
mix stated above are summarized in Table IV-1. Variation in reaction condi-
tions and in amounts of methyl chloride recycled for further chlorination
changes the co-product yield ratios and therefore changes the relative amounts
of storage and loading emissions for the individual products.
I. Process Emissions
a. Recycled-Methane Inert-Gas Purge Vent -- Inert gases enter the process with
feeds to the chlorination chamber and will remain with the unreacted methane
throughout the methane purification procedure. A portion of the recycled
methane stream is vented to prevent a buildup of inert gases, causing a loss of
VOC (Vent A, Fig. III-l). From information supplied by a producer,1 the non-
methane VOC emissions resulting from this inert-gas purge were calculated to be
2.10 kg of chloromethanes per Mg of total chloromethanes capacity. The temper-
ature of the vented gases is approximately 30°C.1 The composition, of the
vented gases is shown in Table IV-2. Calculations based on the amount of inert
gases reported and on chlorine requirements for a 200,000-Mg/yr capacity plant
producing the product mix selected for the model plant show that very high
purity (99.9 wt % pure) chlorine is being used. Decreases in chlorine purity
would increase the amount of inert-gas and VOC emissions.
b. Drying-Bed Regeneration Vent - The drying bed for the recycled methane must be
regenerated periodically (Vent B, Fig. III-l). This regeneration results in
VOC emissions of about 0.052 kg per Mg of total chloromethanes produced as cal-
culated from information supplied by a producer. The composition of gases
vented at the source was reported as 67 mole % methyl chloride and 33 mole %
methane.*
-------
IV-3
Table IV-1. Total Uncontrolled Nonmethane VOC Emissions for
Model Plant Producing Chloromethanes by Methane Chlorination Process
Source
Recycled-methane inert-gas purge
ventd
In-process storage
e
Drying-bed regeneration vent
Distillation-area emergency inert-
gas ventd
Product storage
Handling6
Fugitive
J JT
Secondary '
Total
Stream
Designation
(Fig.III-2)
A
D
B
C
D
D
F
K
Total VOC
. c
Ratio
(kg/Mg)
2.10
0.63
0.052
0.20
0.92
0.36
1.74
0.13
6.13
Emission
Rate
(kg/hr)
48.0
. 14.5
1.19
4.48
20.9
8.33
39.7
2.99
140
Uncontrolled emissions are emissions from process using no additional control
devices other than those necessary for economical operation.
Emissions include methyl chloride, methylene chloride, chloroform, and carbon
tetrachloride. Methane emissions are not included.
°kg of emissions per Mg of chloromethanes produced.
See ref 1.
SSee ref 2.
See ref 5.
-------
IV-4
Table IV-2. Characteristics of Emissions from Recycled-Methane
Inert-Gas Purge Vent from Methane Chlorination Process
—
Constituent
Oxygen
Nitrogen
Methane
Methyl chloride
Methylene chloride
Chloroform
Carbon tetrachloride
. — .
Quantity
(mole %)
n l S
18.94
65.91
14.78
0.22
0.01
<0.01
Emission Ratio
(kq/Mq)
0.013
1.45
2.89
2.04
0.051
0.0033
<0.0042
aSee ref. 1.
bkg of emissions per Mg of total chloromethanes capacity.
-------
IV-5
c. Distillation-Area Emergency Inert-Gas Vent -- Process emissions result from
emergency venting (safety relief venting) of distillation-area equipment (Vent C,
Fig. III-l). These emissions can be vented back into the system. VOC emissions
during the emergency venting were calculated from information supplied by a
producer to be 0.20 kg per Mg of total chloromethanes capacity.2 The composition
of uncontrolled emissions from this source was reported as 40 mole % chlorine,
34.6 mole % hydrogen chloride, 22.4 mole % chlorinated VOC and 3 mole % air.
2. Fugitive Emissions
Process pumps, valves, flanges, and compressors are potential sources of
fugitive emissions. The model plant is estimated to have 80 pumps (including
spares), 2000 process valves including 70 relief valves, and a compressor. The
factors shown in Appendix C were used to determine the fugitive emissions listed
in Table IV-1.
3. Storage and Handling Emissions
Emissions result from storage and handling of methylene chloride, chloroform,
and carbon tetrachloride. No methyl chloride storage and handling emissions
are projected, because methyl chloride is stored in pressure vessels. The
sources of storage and handling emissions for the model plant are shown on the
flow diagram in Fig. III-l (Source D). Storage tank conditions for the model
plant are given in Table IV-3. The uncontrolled storage emissions in Table IV-1
were calculated with the emission equations from AP-423 and on the assumptions
of a diurnal temperature variation of 12°C and of fixed-roof tanks that on the
average are half full. However, breathing losses were divided by 4 to account
for recent evidence indicating that the AP-42 breathing loss equation overestimates
emissions.4
Emissions from loading methylene chloride, chloroform, and carbon tetrachloride
product into tank cars and trucks were calculated with the equations from AP-42.3
Submerged loading into clean tank cars and trucks was assumed for the emission
calculations. Another assumption was that the loading device for methyl chloride
has a vapor return loop and therefore creates no emissions except for emissions
that would be classified as fugitive in nature.
-------
IV-6
Table IV-3. Storage Requirements for Model Plant Producing
Chloromethanes by Chlorination of Methane Process
_ —
Stored Material .._
Methyl chloride
Crude methylene chloride —
chloroform — carbon
tetrachloride
Methylene chloride
Chloroform
Carbon tetrachloride
Methylene chloride
Chloroform
Carbon tetrachloride
Number of
Tanks
i
J.
1
o
£
I
-\
-L
Tank Size
(m3)
1890
"7^"7
t 3 f
?27
£j £* 1
114
•5Q
J O
3780
1510
757
Turnovers
Per Year
23
6*
150
147
166
18
22
17
—
Bulk Liquid
Temperature
(°C)
20
35
30
T C
35
35
20
**» r\
20
20
_^ —
*Surge tank operated at nearly constant level.
-------
IV-7
4. Secondary Emissions
Secondary VOC emissions can result from the handling and disposal of process
waste liquid. For the model plant the potential sources of secondary emissions
from waste liquid are indicated on the flow diagram, Fig. III-l (Source K).
These liquid streams are waste caustic from the scrubbers on the methyl chloride
and recycle methane streams and the crude chloromethanes neutralizer, sulfuric
acid from the dryer on the methyl chloride product stream, the high-density
salt solution discharge from the crude chloromethane dryer, and heavies from
the carbon tetrachloride distillation column. The waste caustic and salt solu-
tions from the dryer are discharged from the process as aqueous waste and the
sulfuric acid is stored for reclamation or sales. The heavies from carbon tetra-
chloride distillation are incinerated. The secondary emissions given for the
model plant in Table IV-1 were calculated based on the chloromethanes content
reported for total wastewater discharges from a methane chlorination process1
and the chloromethanes content of sulfuric acid waste from a process based on
both the methanol hydrochlorination and methyl chloride chlorination and the
methane chlorination processes.5
-------
IV-8
C. REFERENCES*
1. J. Beale, Dow Chemical U.S.A., Midland, MI, letter dated Apr. 28, 1978, to
L. Evans, EPA, concerning Dow facility at Freeport, TX.
2. S. L. Arnold, Dow Chemical U.S.A. Midland, MI, letter dated July 31, 1979, to
David R. Patrick, EPA.
3. C. C. Masser, "Storage of Petroleum Liquids," pp. 4.3-2 to 4.3-11 in Supplement
No. 7 for Compilation of Air Pollutant Emission Factors, AP-42, 2d ed., EPA,
Research Triangle Park, NC (April 1977).
4. E. C. Pularski, TRW, Inc., letter dated May 30, 1979, to Richard Burr, EPA.
5. J. J.. Muthig, Allied Chemical, Moundsville, WV, letter dated Mar. 31, 1978, to
D. R. Goodwin, EPA.
*A reference located at the end of a paragraph usually refers to the entire para-
graph. If another reference relates to certain portions of the paragraph, the
reference number is indicated on the material involved. When the reference
appears on a heading, it refers to all the text covered by that heading.
-------
V-l
V. APPLICABLE CONTROL SYSTEMS
The controls described in this section relate to the manufacture of chloromethanes
by the methane chlorination process.
A. EMISSION CONTROLS FOR MODEL PLANT
1. Process Emissions
a- Recycled-Methane Inert-Gas Purge Vent -- Emissions resulting from venting of
inert gases from the recycled-methane stream (Vent A, Fig. III-l) constitute
about 34% of the total model-plant uncontrolled emissions. No controls are
reported by industry for this stream. Several alternatives were considered for
control of these emissions. Carbon adsorption was determined to be an impractical
control alternative, because methyl chloride, the major nonmethane VOC in the
vented gases, is highly volatile at practical operating temperatures and pressures
and therefore has a very low loading factor on carbon. Also, streams containing
high concentrations of VOC must be diluted with additional inert gases to prevent
large temperature increases in the carbon bed. Both factors would contribute
to a high unit cost per unit of VOC recovered. The inert gas composition of
feed materials to the reactor is a major determinant in the total amount of
VOC emitted. Use of higher purity raw materials was not considered as a control
option, because the model plant is assumed to use purified (liguified and re-
vaporized) chlorine.
Thermal oxidation also was considered not to be a sufficiently feasible option
to justify a detailed study. Formation of hydrogen chloride during oxidation
of chlorinated VOC would necessitate corrosion-resistant materials of construc-
tion and the addition of an acid-gas scrubber for the vent gases from the oxidizer.
Both these factors would contribute to high capital and operating costs. If,
however, a producer has a thermal oxidizer operating on other chlorinated wastes,
then the addition of this emission stream for control may be feasible.
The control option selected for detailed study was an absorption system utilizing
chloroform drawn from storage, chilled, and used as an absorbent. Absorption
in a less volatile hydrocarbon is a common method for the recovery of light
-------
V-2
hydrocarbons. For example, the methane chlorination model process uses absorp-
tion, as is shown in Fig. III-l, to separate chloromethanes from other gases
exiting the reactor. An absorption system could be used for control of the
recycled-methane inert-gas purge vent and in-process storage tank emissions.
The control of these combined sources by a single absorber is the conceptual
approach used for the model plant. The absorbent and absorbed materials can be
returned to the process for recovery.
The absorber system for combined recycled-methane inert-gas purge vent and in-
process storage emissions is a preliminary design for cost estimating purposes
per the standard design methods described by Treybal.1 The design has not been
optimized. The design parameters with the greatest effect on control effi-
ciency are final gas temperature and pressure due to their effects on the vapor
pressure of the VOC components and the composition of the gaseous stream vented
from the absorber. As a general relationship the total VOC emitted from the
absorber will vary directly with the absolute pressure of the system. An
absorber designed to operate at -40°C and at a pressure of about 2 X 10s Pa
will reduce the model-plant uncontrolled emissions from the combined recycled-
methane inert-purge vent and in-process storage sources by about 92% as shown
for the model plant in Table V-l. A reduction of about 72% would be achieved
if the operating temperature were increased to -29°C.2
b. Drying-Bed Regeneration Vent -- Emissions resulting from regeneration of the
methyl chloride drying bed are uncontrolled because they constitute only about
1% of total model-plant uncontrolled emissions and are intermittent. Emissions
from this vent were not included for control by the absorption system because
moisture from the regeneration of the drying bed would cause difficulties in
recycling the recovered material to the process.
c. Distillation-Area Emergency Inert-Gas Purge Vent -- Emissions resulting from
emergency venting of distillation-area equipment remain uncontrolled because
they constitute only about 1% of the total uncontrolled model plant emissions
and are intermittent. These emissions were not included for control by the
absorption system discussed above because hydrogen chloride is reported to be
included in the emissions.3 Special materials of construction would be re-
quired for the absorption system if these emissions had been included for
control.
-------
Table V-l. Controlled VOC Emissions for Model Plants Producing Chloromethanes by Methane Chlorination
Stream VOC
Designation Control Device Reduction Ratio3
Source (pig- III-l) or Techniaue m n™/n,«i
Recycled-methane inert-gas A
purge vent
b
In-process storage D
Drying-bed regeneration vent B
f-i
Distillation-area emergency c
inert-gas vent
Product storage D
Handling D
Fugitive F
c
Secondary K
Total
Absorber 92 0.22
None o.052
None o.20
Condensation 80.0 0.18
None o . 36
Detection and correction 67.5 0.57
of leaks
None 0>13
1.71
Emissions
Rate
(kg/hr)
5.0
1.19
4. 48
4.18
8.33
12.9 <
i
LO
~2 . 99
39.1
}cg of emissions per Mg of chloromethanes produced.
b /
Combined for control by absorber.
c
Uncontrolled.
-------
V-4
Also, the highly intermittent nature of these emissions could cause difficulties
in sizing a control device.
2. Fugitive Emissions
Control for fugitive sources is discussed in a separate EPA report.4 The con-
trolled fugitive emissions shown in Table V-l are based on the factors given in
Appendix C and on the assumption that any major leaks would be detected and
repaired.
3. Storage
Storage emissions can be controlled by condensation or absorption. For the
model plant it is assumed that in-process storage emissions are combined with
emissions from the inert-gas purge vent for control and that condensation is
used to control product storage emissions. Total SOCMI VOC storage emissions
are covered in a separate EPA report.5
4. Handling Emissions
No unique handling controls are known to be practiced by industry. Therefore
the handling emissions for the controlled model plant are the same as for the
uncontrolled model plant.
5. Secondary Emissions
Secondary sources contribute about 2% of the total uncontrolled model-plant
emissions. No unique secondary emissions control techniques are known to be
practiced by industry. Therefore the secondary emissions for the controlled
model plant are the same as for the uncontrolled model plant. Emissions from
secondary sources are discussed in a separate EPA report.fo
-------
V-5
B. REFERENCES*
1. R. E. Treybal, Mass-Transfer Operations, chaps. 6 and 8, McGraw-Hill, New York,
1955.
2. S. L. Arnold, Dow Chemical U.S.A., Midland, MI, letter to David L. Patrick,
EPA, July 31, 1979.
3. J. Beale, Dow Chemical U.S.A., Midland, MI, letter to L. Evans, EPA, April 28,
1978.
4. D. G. Erikson and V. Kalcevic, IT Enviroscience, Inc., Fugitive Emissions
(September 1980) (EPA/ESED report, Research Triangle Park, NC).
5. D. G. Erikson, IT Enviroscience, Inc., Storage and Handling (September 1980)
(EPA/ESED report, Research Triangle Park, NC).
6. J. Cudahy and R. L. Standifer, IT Enviroscience, Inc., Secondary Emissions
(June 1980) (EPA/ESED report, Research Triangle Park, NC).
*A reference located at the end of a paragraph usually refers to the entire
paragraph. If another reference relates to certain portions of the paragraph,
the reference number is indicated on the material involved. When the reference
appears on a heading, it refers to all the text covered by that heading.
-------
VI-1
VI. IMPACT ANALYSIS
A. ENVIRONMENTAL AND ENERGY IMPACTS
Table VI-1 shows the environmental impact of reducing VOC emissions by appli-
cation of the indicated control systems for the 200,000-Mg/yr capacity model
plant using the methane chlorination process for production of chloromethanes.
Use of these control devices or techniques results in the reduction of VOC
emissions by 885 Mg/yr for the model plant. Individual impacts are discussed
below.
1. Model Plant
a. Recycled-Methane Inert-Gas Purge Vent and In-Process Storage -- An absorber for
control of combined emissions from the recycled-methane inert-gas purge vent
and in-process storage sources reduced model-plant VOC emissions by 504 Mg/yr.
The absorber uses electric power, but the energy required is small.
b. Other Emissions (Other Process, Other Storage, Handling, Fugitive, and Secondary) -•
Control methods described for these sources are a condenser for product storage
sources and correction of leaks for fugitive emissions. Application of these
systems results in a reduction in VOC emissions of 381 Mg/yr for the model plant.
No control devices are described for process sources other than the recycled
methane inert-gas purge vent or for handling and secondary sources.
2. Industry Emissions
Only one producer (Dow at Freeport, TX) is known to operate a chloromethane
facility based solely on the methane chlorination process. Two producers (Vulcan
at Wichita, KS, and Allied at Moundsville, WV) operate chloromethane production
facilities that are based at least in part on methane chlorination (approximately
15,000 Mg/yr total methane capacity), but most of the capacity at these facilities
is based on methanol hydrochlorination and methyl chloride chlorination. Therefore
the Dow 200,000-Mg/yr capacity chloromethanes plant represents the methane chlori-
nation industry and was the basis for the model plant capacity as described
previously in this report. Because the actual production rate of the single
facility is proprietary information the model capacity was assumed to be the
industry production rate. The methane chlorination industry emissions were
-------
VI-2
Table VI-1. Environmental Impact of Controlled VOC
Emissions for 200,000-Mg/yr Methane Chlorination Model Plant
Emission Source
Stream
Designation
(Fig. III-l)
Control Device
or Technique
Emission Reductioi
(Mg/yr)'
Recycled-methane inert-gas
purge vent*3
b
In-process storage
Drying-bed regeneration
A
D
B
Absorber
None
92 504
vent
Distillation-area emergency
inert-gas vent
Product storage
Handling
Fugitive
Secondary
Total
D
D
F
K
None
Condenser
None
80
Detection and correction 67.5
of leaks
None
146
235
885
aAnnual reduction is based on 8760 hr of operation. Process downtime is normally expected
to range from 5 to 15%. If the hourly rate remains constant, the annual production and
annual VOC emissions will be correspondingly reduced. Control devices will usually operat
on the same cycle as the process. From the standpoint of cost-effectiveness calculations,
the error introduced by assuming continuous operation is negligible .
Combined for control.
-------
VI-3
determined from actual process, storage, and handling emissions as reported by
Dow,-1 from the secondary emissions as determined from the chloromethanes content
in the wastewater discharged at the Dow plant1 and from the chloromethanes con-
tent in spent sulfuric acid reported by Allied;2 and from the estimate that
fugitive emissions were uncontrolled and similar to those from the uncontrolled
model plant. The industry emissions are listed below:
Emissions
Source (kg/hr)
Process 53.7
Storage 2.9
Handling 23.4
Secondary 3.0
Fugitive 39.7
Total 122.7
Storage emissions were calculated from reported data1 to be about 94% controlled
by condensation. No other control devices were reported.
B. CONTROL COST IMPACT
This section gives estimated costs and cost-effectiveness data for control of
VOC emissions resulting from the production of chloromethanes by the methane
chlorination process. Details of the model plant (Fig. III-l) are given in
Sects. Ill and IV.
Capital cost estimates represent the total investment required for purchase and
installation of all equipment and material needed for a complete emission control
system performing as defined for a new plant at a typical location. These esti-
mates do not include the cost of research and development, of land acquisition,
or of chloromethanes production lost during installation or startup. Also,
the potential need for additional chloroform distillation capacity is not
considered.
Bases for the annual cost estimates for the control alternatives include utilities,
raw materials, maintenance supplies and labor, recovery credits, capital charges,
and miscellaneous recurring costs such as taxes, insurance, and administrative
-------
VI-4
overhead. (Manpower costs are minimal and therefore are not included.) The
cost factors that were used are itemized in Table VI-2. Emission recovery
credits are based on the raw material value of the material being recovered.
Annual costs are for a 1-year period beginning December 1979.
1. Process Emissions
The major source of emissions from the methane chlorination process is the recycled-
methane inert-gas purge vent. These emissions and those from in-process storage
are controlled with an absorption system. The cost estimate for the control
system is as follows:
Total installed capital cost $130,000
Utilities $1,200
Fixed costs $38,000
Recovery credits ($125,000)
Net annual savings ($85,800)
Emission reduction 504 Mg/yr; 92%
Cost effectiveness (per Mg) ($170) (savings)
The absorbent material for the VOC emissions is chloroform from the process,
and the recovery credit is based on the value of the net recovery of methyl
chloride, methylene chloride, chloroform, and carbon tetrachloride, which are
recycled to the process. Cost effectiveness is the net annual cost divided by
the Mg/yr emission reduction.
Other process emissions, which originate at the drying-bed regeneration and
distillation-area emergency inert-gas vents, constitute only about 4% of the
total uncontrolled model-plant emissions and remain uncontrolled.
2. Storage and Handling Sources
Another EPA report covers storage emissions and their applicable controls for
all the synthetic organic chemicals manufacturing industry.3
a. In-Process Storage -- In-process storage sources can be controlled in combination
with the absorption system discussed previously or by use of chilled condensers.
-------
VI-5
Table VI-2. Cost Factors Used in Computing Annual Costs
Item
Factor
Utilities
Electricity
Cooling water
Operating time
Operating labor
Fixed costs
Maintenance labor, 6%
Capital recovery, 18% (10 yr life @ 12% interest)
Taxes, insurance, administration, 5%
Recovery credits3
Methyl chloride
Methylene chloride
Chloroform
Carbon tetrachloride
$8.33/GJ
$0.026/m3
8760 hr/yr
Minor; not considered
29% of installed cost
$243/Mg
$265/Mg
$278/Mg
$284/Mg
Based on raw material costs for chlorine in "Current Prices of Chemicals
and Related Materials," Chemical Marketing Reporter, April 1, 1980, and a
methane cost of $0.07/1000 1.
-------
VI-6
b. Product Storage -- The systems for control of product storage emissions include
the use of chilled condensers.
c. Handling -- No system has been defined for control of the emissions from handling
sources.
3. Fugitive Sources
A control system for fugitive sources is defined in Appendix C. Another report
describes fugitive emissions and their applicable controls for the synthetic
organic chemicals manufacturing industry.4
4. Secondary Sources
No control system has been identified for controlling the secondary emissions
from the process. Another report covers secondary emissions and their applicable
controls for the synthetic organic chemicals manufacturing industry.5
-------
VI-7
C. REFERENCES*
1. J. Beale, Dow Chemical, U.S.A., Midland, MI, letter to L. Evans, EPA, Apr. 28, 1978.
2. J. J. Muthig, Allied Chemical, Moundsville, WV, letter to D. R. Goodwin, EPA,
Mar. 31, 1978.
3. D. G. Erikson, IT Enviroscience, Inc., Storage and Handling (September 1980)
(EPA/ESED report, Research Triangle Park, NC).
4. D. Erikson and V. Kalcevic, IT Enviroscience, Inc., Fugitive Emissions
(September 1980) (EPA/ESED report, Research Triangle Park, NC).
5. J. Cudahy and R. L. Standifer, IT Enviroscience, Inc., Secondary Emissions
(June 1980) (EPA/ESED report, Research Triangle Park, NC).
*A reference located at the end of a paragraph usually refers to the entire
paragraph. If another reference relates to certain portions of the paragraph,
the reference number is indicated on the material involved. When the reference
appears on a heading, it refers to all the text covered by that heading.
-------
VII-1
VII. SUMMARY
The four chloromethanes -- methyl chloride, methylene chloride, chloroform, and
carbon tetrachloride -- are produced by the chlorination of methane. Projections
for anticipated usage patterns for the chloromethanes as detailed in Se.ct. II
indicate above-average growth in methylene chloride and chloroform use, nearly
static usage for methyl chloride, and severe declines in demand for carbon
tetrachloride. No plans are known for new chloromethanes production facilities
based on the methane chlorination process. Dow reportedly planned to increase
its production capacity by late 1979.1
The major emission sources for the methane chlorination model plant are the
recycled-methane inert-gas purge vent, in-process storage, final-product storage,
and handling. The first two sources can be combined for potential control with
an absorber, which results in about 92% control. The final-product storage can be
controlled by use of a chilled condenser. No unique control systems are proposed
for the handling sources.
The methanol hydrochlorination and methyl chloride chlorination processes, which
produce three of the chloromethanes (methyl chloride, methylene chloride, and
chloroform), are described in another report2 to have estimated current industry
emissions of 252 kg/hr. Based on a 1979 production projection of about 565,000 Mg,
the industry using these processes therefore is estimated to have an emission
ratio of 3.9 kg of VOC per Mg of chloromethanes produced. By comparison the
methane chlorination process described in this report has current industry
emissions of 122.7 kg/hr for an estimated emission ratio of 5.4 kg of VOC per
Mg of chloromethanes produced.
Existing plant considerations are discussed in Appendix D.
1J. C. Blackford, "CEH Marketing Report on Methanol," pp. 674.5022Z--674.5023G
i-n Chemical Economics Handbook, Stanford Research Institute, Menlo Park, CA
(August 1977).
o
F. D. Hobbs and C. W. Stuewe, IT Enviroscience, Inc., Chloromethanes Manufactured
by Methanol Hydrochlorination and Methyl Chloride Chlorination (November 1980)
(EPA/ESED report, Research Triangle Park, NC).
-------
APPENDIX A
Table A-l. Physical Properties of Chloromethane Compounds
Chemical name
Synonym
Molecular formula
Molecular wciyht
Physical state
Chloromelhaiie
Methyl chloride
CH Cl
50.49
Gas
Pichlorome thane
Methylene
mu thy lei
c.i2ci2
84.93
Liquid
chloride,
ne dichloride
Chloroform
Trichlorqrac thane
CIIC1
119.31
Liquid
Carbon tetrachlorlde
Tetrachloromothane, per-
thlozeancithanc, meth.ine
tctrachloride
CC1,
153.82
Liquid
Wipor pressure
Vapor specific gravity
Boiling point
Molting point
Density
Water solubility
5.0 atm at 22eCd
1.78
-24.2'C
-97.73°C
0.9159 g/ml at 20*C/4"C
4.9 g/liter
435.8 mm !lg at 25 "C
2.93
40°C
-95.1'C
1.3266 g/ml at 20'C/4°C
Slight
200 mm llg at 25.9°C
4.12
61.26'C
-63.5'C
1.49845 g/ml at 15'C
8.0 g/liter
115.2 mm Hg at 25°C
5.32
76.54°C
-22.99'C
1.5940 g/ml at 20*C/4*C
Insoluble
J. Dorigan et al., "Scoring of Organic Air Pollutants. Chemistry, Production
(Chemicals F-10," p. AIII-174 in MTR-7428, Rev. 1, Appendix III, MITRE Corp.,
b!hiJ., p. MII-186.
Cllud., p. AI-222.
ferry's Chemical Engineers' Handbook, 4th ed., p. 3-60, McGraw-Hill, New York, 1963.
and Toxicity of Selected Synthetic Organic Chemicals
METREK Division (September 1976).
-------
B-l
APPENDIX B
AIR-DISPERSION PARAMETERS
Table B-l. Air-Dispersion Parameters for Uncontrolled and
Controlled Model Plant Using Methane Chlorination Process (200,000 Mg/yr)
Source
Recycled-methane inert-gas
purge vent
Crude storage
Methylene chloride day
tanks (2)
Chloroform day tanks (2)
Carbon tetrachloride day
tanks (2)
Drying-bed regeneration
vent
Distillation-area emergency
inert-gas vent
Methylene chloride product
storage
Chloroform product storage
Carbon tetrachloride
product storage
Handling
Fugitive
Secondary
Absorber
Drying-bed regeneration
ventc
Distillation-area emergency
inert-gas ventc
Product storage condenser
Handling
Fugitive
Secondary
Emission Tank Tank Stack Stack
Rate Height Diameter Height Diameter
(g/sec) (m) (m) (m) (m)
Uncontrolled Emissions
13.3 11.0 0.025
0.79 9.8 9.9
1.07 7.3 6.3
0.43 7.3 4.5
0.12 2.4 4.5
0.33 11.0 0.025
1.24 11.0 0.025
4.13 12.2 19.9
1.30 12.2 12.6
0.39 9.8 9.9
2.31
11.0
0.83
Controlled Emissions
1.78 11.0 0.025
0.33 11.0 0.025
1.24 11.0 0.025
1.16
2.31
3.58
0.83
Discharge ' Flow
Temperature Rate
(K) (m3/sec)
303 4.4 X 10~2
308
303
308
308
393 2.8 X 10~*
308 4.6 X 10"4
293
293
293
233 3.7 X 10~2
393 2.8 X 10~4
308
Discharge
Velocity
(m/sec)
90
.0.57
0.93
75
0.57
One except where indicated otherwise.
b
Distributed over an area of about 50 X 100 m.
Will reamin uncontrolled.
-------
C-l
APPENDIX C
FUGITIVE-EMISSION FACTORS*
The Environmental Protection Agency recently completed an extensive testing
program that resulted in updated fugitive-emission factors for petroleum re-
fineries. Other preliminary test results suggest that fugitive emissions from
sources in chemical plants are comparable to fugitive emissions from correspond-
ing sources in petroleum refineries. Therefore the emission factors established
for refineries are used in this report to estimate fugitive emissions from
organic chemical manufacture. These factors are presented below.
Uncontrolled
Emission Factor
Controlled
Emission Factor'
Source
Pump seals
Light-liquid service
Heavy-liquid service
Pipeline valves
Gas/vapor service
Light-liquid service
Heavy-liquid service
Safety/relief valves
Gas/vapor service
Light-liquid service
Heavy-liquid service
Compressor seals
Flanges
Drains
(kg/hr)
0.12
0.02
0.021
0.010
0.0003
0.16
0.006
0.009
0.44
0.00026
0.032
(kq/hr)
0.03
0.02
0.002
0 . 003
o.od'bs
0.061
0.006
0.009
0.11
0.00026
0.019
Based on monthly inspection of selected equipment; no inspection of
heavy-liquid equipment, flanges, or light-liquid relief valves,-
10,000 ppmv VOC concentration at source defines a leak; and 15 days
allowed for correction of leaks.
Light liquid means any liquid more volatile than kerosene.
*Radian Corp., Emission Factors and Frequency of Leak Occurrence for Fittings
in Refinery Process Units, EPA 600/2-79-044 (February 1979).
-------
D-l
APPENDIX D
EXISTING PLANT CONSIDERATIONS
A. CURRENT INDUSTRY
Only four chloromethane producing facilities Allied at Moundsville, WV; Dow at
Freeport, TX, and Pittsburg, CA; and Vulcan at Wichita, KS use methane as a
feed material. The Allied and Vulcan facilities primarily utilize the methanol
hydrochlorination and methyl chloride chlorination processes; methane chlorination
accounts for only about 5% of the Allied capacity and 10% of the Vulcan capacity.1,2
The Dow plant at Pittsburg, CA, may utilize methane as a feed to a chlorinolysis
process. Therefore the single facility known to utilize the methane chlorination
process exclusively is the Dow plant at Freeport, TX. That plant accounts for
about 15% of the total chloromethanes industry capacity. An increase in capacity
was scheduled to be brought on-stream late in 1979 at that plant.3
Dow reports use of a condenser for control of storage emissions and scrubbers
for control of hydrogen chloride emissions.4
B. RETROFITTING CONTROLS
The primary difficulty associated with retrofitting may be in finding space to
fit the control device into existing plant layout. Because of costs associated
with this difficulty it may be appreciably more expensive to retrofit emission
control systems than to install a control system during construction of a new
plant.
The absorption device conceptualized for control of combined emissions from the
inert-gas purge vent and in-process storage vents could be especially difficult
to retrofit. Influence of the control device on equipment, such as chloroform
distillation capacity, should be considered before this control device is con-
sidered for use.
-------
D-2
C.
REFERENCES*
1.
2.
3.
Personal communication between F. D. Hobbs, IT Enviroscience, Inc., and D. Denoon,
Allied Chemical, Moundsville, WV, July 25, 1978.
Personal communication between F. D. Hobbs, IT Enviroscience, Inc., and T. A.
Robinson, Vulcan Materials Company, Wichita, KS, July 28, 1978.
T. F. Killiea, "CEH Product Review on Chlorinated Methanes," pp. 625.2030A -
635.2031G in Chemical Economics Handbook, Stanford Research Institute, Menlo
Park, CA (April 1979)
4. J. Beale, Dow Chemical U.S.A., letter to L. Evans, EPA, April 28, 1978.
*Usually, when a reference is located at the end of a paragraph, it refers to
the entire paragraph. If another reference relates to certain portions of
that paragraph, that reference number is indicated on the material involved.
When the reference appears on a heading, it refers to all the text covered by
that heading.
-------
E-l
APPENDIX E
COST ESTIMATE SAMPLE CALCULATIONS
This appendix contains sample calculations showing how costs presented in this
report were estimated.
The accuracy of an estimate is a function of the degree of data available when
the estimate was made. Figure E-l illustrates this relationship. A contingen-
cy allowance as indicated on this chart has been included in the estimated
costs to cover the undefined scope of the project.
Capital costs given in this report are based on a screening study, as indicated
by Fig. E-l, based on general design criteria, block flowsheets, approximate
material balances, and data on general equipment requirements. These costs
have an accuracy range of +30% to -23%, depending on the reliability of the
data, and provide an acceptable basis to determine the most cost-effective
alternate within the limits of accuracy indicated.
This example is based on use of an absorption system operated at -40°F, with
refrigerated chloroform as the absorbent, to control the emissions from the
recycled-methane inert-gas purge vent and from the in-process storage vents.
The absorption system consists of a pump for metering the chloroform, a refrig-
eration unit for cooling the chloroform, an absorption column, and a compressor
to raise the pressure of the emissions from in-process storage to 2 atm., the
operating pressure of the absorption column. Capital costs for all components
were estimated from IT Enviroscience installed cost data. Cost data compiled
from previous years were adjusted to a December 1979 basis.
Total installed capital cost = $130,000
The annual fixed costs are 29% of the installed cost (see Table VI-6):
0.29 X $130,000 = $38,000 (rounded).
The utility costs are calculated as follows (see Table VI-6):
-------
INFORMATION USED BY ESTIMATOR
ESTIMATED COST
ALLOWANCE.
>REUM. EMG,. STUDY)
PHASE IT
'PREUM. PROC.
PHA5E Iff
^COMPLETE PROCESS
t 2 3
APPROX. CO'bT
EMC,R.4 EST.
(."?• OP TOTAL
PROBABLE
CAP,
Fig. E-l. Precision of Capital Cost Estimates
-MllJ. PROS.
^ CO«bT
\ ^*\\
\\
\
\
\\
\\\
\\
M
*
\
\
\\
\\
\\
A
\\\
\
MACK. PROB.
\ C.O«bT
1
|
1
/
1
III
II
1
1
1
1
1
I
/ Z^
//
^
/
_^
-fcO -40 -20 O 20 4O fcO
RAUG,E - PROBABLE,
ACTUAL. PROJECT
j
/
/
i
/
t
1 /
1 '
,/t
if.
II
I
1 I
/ /
< /
/ /
i ,
/
yf
,
IS
1
O /o Eo t>o 4c
% ALLOWANCE,
TO ;MCLUDE
CO'b
LATENT P,EVl=,lOU - 5/e/"77
-------
E-3
Electricity useage is estimated as 3 kWh per hour
3JcWh „ $0.03 „ 8760 hr .onn/
~~hr~ X ~kWh~ X vF~ = $800/yr (rounded)
yr
Cooling water required is estimated as 8
gpm
8 gal Y $0-10 v 60 min v 8760 hr
min X 1000 gal X hr X - y7~~ = $400/Yr (rounded)
Total utility costs = $800 + $400 = $1,200
The recovery credit is calculated as follows (see Table VI-6)
Methyl chloride = ^^3 x $|43 = $82/400/yr
Methylene chloride = 129 Mg x ^ - $34,200/yr
yr Mg •*
Chloroform = -59 x = $3/100/yr
Carbon tetrachloride = 25 Mg x ^^ = $7 100/vr
yr Mg ' 1
Totals (VOC = 504 Mg/y) $130,000/yr (rounded)
Estimated cost of reprocessing chloroform used as absorbent = $1.20/Mg
4200 Mg $1.20 .c nnn ,
~7r~~^ X ~MF = $5,000/yr
Net recovery credit = $130,000/yr — $5,000/yr = $125,000/hr.
-------
E-4
Summary of Annual Costs
Fixed Costs
Utility Costs
Recovery Credit
Net Annual Savings
Emission Reduction
= $ 38,000
= 1,200
= (125,000)
= ( 85,800)
= 504 Mg/yr
Cost effectiveness =
= ($l70/Mg) (savings)
-------
6-i
REPORT 6
CHLOROMETHANES MANUFACTURED BY
METHANOL HYDROCHLORINATION AND METHYL CHLORIDE CHLORINATION PROCESSES
F. D. Hobbs
C. W. Stuewe
IT Enviroscience
9041 Executive Park Drive
Knoxville, Tennessee 37923
Prepared for
Emission Standards and Engineering Division
Office of Air Quality Planning and Standards
ENVIRONMENTAL PROTECTION AGENCY
Research Triangle Park, North Carolina
November 1980
This report contains certain information which has been extracted from the
Chemical Economics Handbook, Stanford Research Institute. Wherever used, it
has been so noted. The proprietary data rights which reside with Stanford
Research Institute must be recognized with any use of this material.
D6A
-------
6-iii
CONTENTS OF REPORT.6
Page
I. ABBREVIATIONS AND CONVERSION FACTORS 1-1
II. INDUSTRY DESCRIPTION U-l
A. Reason for Selection II-l
B. Methyl Chloride H-l
C. Methylene Chloride H-6
D. Chloroform II-9
E. References 11-12
III. PROCESS DESCRIPTION III-l
A. Introduction III-l
B. Methanol Hydrochlorination and Methyl Chloride Chlorination III-l
C. References III-6
IV. EMISSIONS jv-i
A. Methanol Hydrochlorination and Methyl Chloride Chlorination IV-1
B. Other Processes IV-7
C. References IV-8
V. APPLICABLE CONTROL SYSTEMS V-l
A. Emission Controls for Model Plants V-l
B. References V_5
VI. IMPACT ANALYSIS Vj-!
A. Control Cost Impact VI-1
B. Environmental and Energy Impacts VI-7
VII. PRODUCT ASSESSMENT VII-1
A. Summary VII-1
B. References VII-4
-------
6-v
APPENDICES FOR REPORT 6
A. PHYSICAL PROPERTIES OF CHLOROMETHANE COMPOUNDS A._l
B. AIR-DISPERSION PARAMETERS E.l
C. SAMPLE CALCULATIONS c_1
D. FUGITIVE-EMISSION FACTORS p.!
E. EXISTING PLANT CONSIDERATIONS .
-------
6-vii
Number
II-l
II-2
II-3
II-4
II-5
II-6
IV-1
IV-2
V-l
VI-1
VI-2
VI-3
VII-1
A-l
B-l
C-l
C-2
C-3
TABLES OF REPORT 6
Methyl Chloride Usage and Growth
Methyl Chloride Capacity
Methylene Chloride Usage and Growth
Methylene Chloride Capacity
Chloroform Usage
Chloroform Capacity
Uncontrolled VOC Emissions
Storage Requirements
Controlled VOC Emissions
Cost Factors Used in Computing Annual Costs
Absorber System Control Cost Summary
Environmental Impact
Summary of Emissions
Physical Properties of Chloromethane Compounds
Air-Dispersion Parameters
Stoichiometry for Chlorine Requirements
Ratios of Inert Gases to Total Chloromethanes Produced
Calculated Emissions from the Inert-Gas Purge Vents
Page
II-2
II-4
II-7
II-7
11-10
11-10
IV-3
IV-5
V-3
VI-2
VI-3
VI-8
VII-2
A-l
B-l
C-2
C-3
C-3
-------
6-ix
FIGURES OF REPORT 6
II-l Locations of Plants Manufacturing Methyl Chloride II-5
II-2 Locations of Plants Manufacturing Methylene Chloride II-8
II-3 Locations of Plants Manufacturing Chloroform 11-11
III-l Process Flow Diagram III-3
VI-1 Installed Capital Cost vs Plant Capacity VI-4
VI-2 Net Annual Cost vs Plant Capacity VI-5
VI-3 Cost Effectiveness vs Plant Capacity VI-6
-------
1-1
ABBREVIATIONS AND CONVERSION FACTORS
EPA policy is to express all measurements used in agency documents in metric
units. Listed below are the International System of Units (SI) abbreviations
and conversion factors for this report.
To Convert From
Pascal (Pa)
Joule (J)
Degree Celsius (°C)
Meter (m)
Cubic meter (m3)
Cubic meter (m3)
Cubic meter (m3)
Cubic meter/second
(ms/s)
Watt (W)
Meter (m)
Pascal (Pa)
Kilogram (kg)
Joule (J)
To
Atmosphere (760 mm Hg)
British thermal unit (Btu)
Degree Fahrenheit (°F)
Feet (ft)
Cubic feet (ft3)
Barrel (oil) (bbl)
Gallon (U.S. liquid) (gal)
Gallon (U.S. liquid)/min
(gpm)
Horsepower (electric) (hp)
Inch (in.)
Pound-force/inch2 (psi)
Pound-mass (Ib)
Watt-hour (Wh)
Multiply By
9.870 X 10"6
9.480 X 10~4
(°C X 9/5) + 32
3.28
3.531 X 101
6.290
2.643 X 102
1.585 X 104
1.340 X 10~3
3.937 X 101
1.450 X 10~4
2.205
2.778 X 10"4
Standard Conditions
68°F = 20°C
1 atmosphere = 101,325 Pascals
PREFIXES
Prefix
T
G
M
k
m
M
Symbol
tera
giga
mega
kilo
milli
micro
Multiplication
Factor
Example
10
10
10
10
10"
10"
12
9
6
o
,_>
3
6
1
1
1
1
1
1
Tg =
Gg =
Hg -
km =
mV =
Hg =
1
1
1
1
1
1
X
X
X
X
X
X
10
10
12
9
106
10
10
10
3
"3
~6
grams
grams
grams
meters
volt
gram
-------
II-l
II. INDUSTRY DESCRIPTION
A. REASON FOR SELECTION
Four volatile organic compounds (VOC) -- methyl chloride, methylene chloride,
chloroform, and carbon tetrachloride -- comprise the group commonly referred to
as chloromethanes. These compounds were selected for study because preliminary
estimates indicated that their production causes relatively high VOC emissions.
There are four processes by which chloromethanes are produced either as co-products
or as individual products. One of the processes also results in the production
of perchloroethylene as a co-product. This report describes the processes of
methanol hydrochlorination, which yields methyl chloride, and methyl chloride
chlorination, which yields methylene chloride and chloroform. The two processes
are combined for consideration because industry generally utilizes them in com-
bination. Small amounts of carbon tetrachloride are produced as a by-product in
the methyl chloride chlorination, but it is not general industry practice to
purify this carbon tetrachloride directly into product.
The process of methane chlorination, which produces all four chloromethanes, and
the process of mixed hydrocarbon chlorinolysis, which produces carbon tetrachlo-
ride and perchloroethylene is covered by a separate report.1
B. METHYL CHLORIDE
1 - General Description
Methyl chloride is a gas at ambient conditions but is handled commercially in
liquid form (see Appendix A for pertinent physical properties). It is produced
by methanol hydrochlorination or by methane chlorination. The predominant VOC
emissions from its manufacture by the methanol hydrochlorination process are
methyl chloride and methanol.
2. Usage and Growth
The end uses and expected growth rates of methyl chloride are given in Table II-l.
The predominant use of methyl chloride is as an intermediate in the production of
silicones and in the production of tetramethyllead, a gasoline additive. The
expected increase in usage as an intermediate for silicone production combined
-------
II-2
Table II-l. Methyl Chloride Usage and Growth'
Average Annual
Production (%) Growth
End Useb 1977 (%)
Silicone intermediate
Tetramethyllead intermediate
Butyl rubber (catalyst solvent)
Mi s ce 1 laneous
63
18
8
11
10 12
-25
3.5
NA°
See refs 2 and 3.
Amounts consumed as intermediates in continuous production of other chloro-
methanes not included.
f-<
Not available.
-------
II-3
with decreases in usage as an intermediate for tetramethyllead production, which
o
is being restricted as a gasoline additive, will result in nearly static produc-
tion patterns for methyl chloride. Large amounts of the methyl chloride manu-
factured are not recovered as product but are further chlorinated to produce
methylene chloride and chloroform. This usage is not included in the production
and end-use statistics.
The current domestic methyl chloride prod^c^ion capacity is reported to be about
283,000 Mg/yr, with the 1979 production utilizing only about 72% of that capa-
4
city. The annual growth in methyl chloride production is expected to remain
static or at best to increase by 5% annually. Even at the 5% annual growth rate,
production would reach only about 83% of capacity by 1982. There are no known
plans for new methyl chloride production facilities.
3. Domestic Producers
There are ten domestic producers of methyl chloride operating 13 plants. Table II-2
lists the producers, locations, capacities, and processes in use; Fig. II-l shows
the plant locations. The Dow plant at Freeport, TX, produces methyl chloride by
chlorination of methane. Allied uses hydrochlorination of methanol for about 95%
of its production and uses chlorination of methane for the remaining production.
Vulcan operates two chloromethanes facilities at Wichita, KS. One is a recently
constructed facility based completely on hydrochlorination of methanol, and the
other (older) facility uses both hydrochlorination of methanol and chlorination
of methane. Hydrochlorination of methanol accounts for about 90% of the total
combined production. All other manufacturers produce methyl chloride by hydro-
chlorination of methanol. The two Vulcan plants use all the methyl chloride they
produce as an intermediate and therefore report no methyl chloride capacity as
such. Allied, Diamond Shamrock, Dow, and Stauffer produce the higher chloromethanes
in addition to methyl chloride. The ratios of co-products produced at these
plants are flexible because the methyl chloride may be separated as product or
may be further chlorinated to produce methylene chloride and chloroform. Con-
tinental, Dow Corning, Ethyl, General Electric, and Union Carbide produce only
methyl chloride.
-------
II-4
Table II-2. Methyl Chloride Capacity
a
Plant
Allied, Moundsville, WV
Continental, West lake, LA
Diamond Shamrock, Belle, WV
Dow, Freeport, TX
Dow, Plaquemine, LA
Dow Corning, Carrolton, KY
Dow Corning, Midland, MI
Ethyl , Baton Rouge , LA
General Electric, Water ford, NY
Stauffer, Louisville, KY
Union Carbide , Institute , WV
Vulcan, Geismar, LA
Vulcan, Wichita, KS
Total
1977 Capacity
(X 103 Mg)
llb
46
32b
68b
9
7
46
23
7b
23
c
c
283
Process
Methanol hydrochlorination and
methane chlorination
Methanol hydrochlorination
Methanol hydrochlorination
Methane chlorination
Methanol hydrochlorination
Methanol hydrochlorination
Methanol hydrochlorination
Methanol hydrochlorination
Methanol hydrochlorination
Methanol hydrochlorination
Methanol hydrochlorination
Methanol hydrochlorination
Methanol hydrochorination and
methane chlorination
See ref 3.
Production ratios vary with amount of methyl chloride separated as product and
amount chlorinated for methylene chloride and chloroform manufacture.
CA11 methyl chloride is chlorinated to methylene chloride and chloroform.
-------
II-5
1. Allied, Moundsville, WV
2. Continental, Westlake, LA
3. Diamond Shamrock, Belle, WV
4. Dow, Freeport, TX
5. Dow, Palquemine, LA
6. Dow Corning, Carrolton, KY
7. Dow Corning, Midland, MI
8. Ethyl, Baton Rouge, LA
9. General Electric, Waterford, NY
10. Stauffer, Louisville, KY
11. Union Carbide, Institute, WV
12. Vulcan, Geismar, LA
13. Vulcan, Wichita, KS
Fig. II-l. Locations of Plants Manufacturing Methyl Chloride
-------
II-6
C. METHYLENE CHLORIDE
1. General Description
Methylene chloride is a heavy, volatile liquid at ambient conditions (see
Appendix A for pertinent physical properties) and is produced by chlorination of
either methyl chloride or methane. Emissions from its manufacture include all
the chloromethanes.
2. Usage and Growth
Table II-3 gives the end uses and expected production growth rates of methylene
chloride, which is used predominantly as a solvent. Its nonflammability and low
acute toxicity contribute to its popularity as a paint remover.
The current methylene chloride production capacity is about 378,000 Mg/yr, with
4
about 75% of that capacity being utilized in 1979. Based on an estimated 11%
2
annual growth in methylene chloride consumption, the demand will nearly equal
the current capacity by 1982.
3. Domestic Producers
In 1979 five domestic producers of methylene chloride were operating seven plants.
Table II-4 lists the producers, locations, capacities, and processes being used;
Fig. II-2 shows the plant locations. The Dow Chemical plant at Freeport, TX,
representing 24% of the total domestic capacity, was the only plant using methane
chlorination exclusively for methylene chloride production. The Vulcan plant at
Wichita, KS, and the Allied plant have both methane chlorination and methyl
chloride chlorination process capabilities. Approximately 5% of Allied1s capacity
and 10% of Vulcan's capacity are based on the methane chlorination process. '
All other plants use methyl chloride chlorination. All producers manufacture
chloromethane co-products, and production ratios vary, depending on the desired
end products.
Vulcan's new 63,500-Mg/yr chloromethane plant at Wichita, KS, using the methyl
chloride chlorination process, provided additional methylene chloride capacity of
36,300 Mg/yr. Dow reportedly planned to expand its methylene chloride production
capacity by late 1979.
-------
II-7
Table II-3. Methylene Chloride Usage and Growth
a,b
End Use
1977 Production (%)
Paint remover
Solvent degreasing
Plastics process
Exports
Aerosol
Miscellaneous
30
20
9
18
19
4
See ref 3.
Data on growth rates not available.
Table II-4. Methylene Chloride Capacity0
Plant
1977 Capacity
(X K33 Mg)
Process
Allied, Moundsville, WV
Diamond Shamrock, Belle, WV
Dow, Freeport, TX
Dow, Plaquemine, LA
Stauffer, Louisville, KY
Vulcan, Geismar, LA
Vulcan, Wichita, KS
Total
23 Methyl chloride chlorination and
methane chlorination
50 Methyl chloride chlorination
92 Methane chlorination
88 Methyl chloride chlorination
28 Methyl chloride chlorination
37 Methyl chloride chlorination
60 Methyl chloride chlorination and
methane chlorination
378
See ref 3.
r^
Other chloromethanes are manufactured as co-products, and capacities for in-
dividual products vary.
-------
II-8
1. Allied, Moundsville, WV
2. Diamond Shamrock, Belle, WV
3. Dow, Freeport, TX
4. Dow, Plaquemine, LA
5. Staufferr Louisville, KY
6. Vulcan, Geismar, LA
7. Vulcan, Wichita, KS
Fig. II-2. Locations of Plants Manufacturing Methylene Chloride
-------
II-9
D. CHLOROFORM
1. General Description
Chloroform is a heavy, volatile liquid at ambient conditions (see Appendix A for
pertinent physical properties) and is made by chlorination of methyl chloride or
methane. Emissions from chloroform manufacture include all the chloromethanes.
2. Usage and Growth
As is shown in Table II-5, the predominant end use of chloroform is as an inter-
mediate in the manufacture of chlorodifluoromethane. Chlorodifluoromethane can
be used as a refrigerant, a solvent, or a propellant or in the manufacture of
fluororesins, but its main use is as a refrigerant. A ban on fluorocarbon pro-
pellants would not significantly affect its production rate.3
The current domestic chloroform production capacity is 237,000 Mg/yr,3 with
1979 production utilizing about 67% of that capacity.4 Based on an estimated 8%
annual growth in chloroform consumption, production would reach 84% of current
capacity by 1982.
3. Domestic Producers
In 1979 five domestic producers were operating seven chloroform-producing plants.
Table II-6 lists the producers, locations, capacities, and processes being used;
Fig. II-3 shows the plant locations. The Dow Chemical plant at Freeport, TX, is
the only facility using methane chlorination exclusively for chloroform produc-
tion. The capacity of this plant is about 20% of the total domestic capacity.
The Allied plant, as well as the Vulcan plant at Wichita, KS, has both methane
chlorination and methyl chloride chlorination process capabilities. Approxi-
mately 5% of Allied1s capacity and 10% of Vulcan's capacity are based on
methane chlorination. ' All other plants use methyl chloride chlorination
exclusively for chloroform production. All producers manufacture chloromethane
co-products, and production ratios vary, depending on the desired end products.
Vulcan's new 63,500-Mg/yr chloromethanes plant at Wichita, KS, which was com-
pleted in 1977, provided an additional capacity of 27,200 Mg/yr. Dow scheduled
an increase in capacity at Freeport, TX, which was to have been brought on-stream
late in 1979.3
-------
11-10
Table II-5. Chloroform Usage
a,b
1974
Production
Chlorod i fluoromethane
Refrigerant, solvent, propellant
Exports
Miscellaneous
91
7
2
See ref 3.
•~)
Data on growth rates not available.
Table II-6. Chloroform Capacity
Plant
1979 Capacity
(X 103 Mg)
Process
Allied, Moundsville, WV
Diamond Shamrock, Belle, WV
Dow, Freeport, TX
Dow, Plaquemine, LA
Stauffer, Louisville, KY
Viilcan, Geismar, LA
Vulcan, Wichita, KS
Total
14
18
46
46
34
28
51
237
Methyl chloride chlorination
and methane chlorination
Methyl chloride chlorination
Methane chlorination
Methyl chloride chlorination
Methyl chloride chlorination
Methyl chloride chlorination
Methyl chloride chlorination
and methane chlorination
See ref 3.
Other chloromethanes are manufactured as co-products, and capacities for
individual products vary.
-------
11-11
1. Allied, Moundsville, WV
2. Diamond Shamrock, Belle, Wv
3. Dow, Freeport, TX
4. Dow, Plaquemine, LA
5. Stauffer, Louisville, KY
6. Vulcan, Geismar, LA
7. Vulcan, Wichita, KS
Fig. II-3. Locations of Plants Manufacturing Chloroform
-------
11-12
E. REFERENCES*
1. F. D. Hobbs and C. W. Stuewe, IT Enviroscience, Inc., Chloromethanes. Methane
Chlorination Process (in preparation for EPA, ESED, Research Triangle Park, NC).
2. A. D. Obshire et al., "CEH Marketing Research Report on Methanol," pp. 674.50231-
674.5033S in Chemical Economics Handbook, Stanford Research Institute, Menlo Park,
CA (June 1980).
3. T. F. Killilea, "CEH Product Review on Chlorinated Methanes," pp. 625.2030A-635.2031G
in Chemical Economics Handbook, Stanford Research Institute, Menlo Park, CA
(April 1979).
4. "Chlorinated Methanes," p. 244 in Chemical Economics Handbook, Manual of Current
Indicators--Supplemental Data, Chemical Information Services, Stanford Research
Institute, Menlo Park, CA (August 1980).
5. Personal communication between F. D. Hobbs, IT Enviroscience, Inc., and D. Denoon,
Allied Chemical, Moundsville, WV, July 25, 1978.
6. Personal communication between F. D. Hobbs, IT Enviroscience, Inc., and
T. A. Robinson, Vulcan Materials Co., Wichita, KS, July 28, 1978.
*A reference located at the end of a paragraph usually refers to the entire paragraph.
If another reference relates to certain portions of the paragraph, the reference
number is indicated on the material involved. When the reference appears on a
heading, it refers to all the text covered by that heading.
-------
III-l
III. PROCESS DESCRIPTION
A. INTRODUCTION
In the United States the main processes of producing chloromethanes consist of
methanol hydrochlorination followed by further chlorination of the methyl chloride
produced. In 1979 about 89% of methyl chloride, 70% of methylene chloride, and
75% of chloroform capacities in the United States were based on these processes.
Some carbon tetrachloride is formed as a Ly-product in the chlorination of methyl
chloride but is not generally directly purified into product by domestic producers.
The unpurified carbon tetrachloride is either sold as is or is used in-house as
feed to carbon tetrachloride--perchloroethylene producing facilities.
B. METHANOL HYDROCHLORINATION AND METHYL CHLORIDE CHLORINATION PROCESSES
1. Basic Process
Although some domestic producers manufacture methyl chloride exclusively by
hydrochlorination of methanol, it is common practice to combine this reaction
with the continuous chlorination of methyl chloride to produce methylene chloride
and chloroform, along with carbon tetrachloride in small amounts as a by-product.
These two processes are discussed as an integral process for the purpose of this
report.
Methyl chloride is produced by the reaction
CH OH + HC1 >• CH Cl + HO
*•* O ^
{Methanol) (Hydrogen (Methyl (Water)
Chloride) Chloride)
Methylene chloride, chloroform, and by-product carbon tetrachloride are then
produced from methyl chloride by the reactions
CH Cl + Cl ^ CHoClo + HC1
•3 £ £ £
(Methyl (Chlorine) (Methylene (Hydrogen
Chloride) Chloride) Chloride)
-------
Ill-2
CH Cl + Cl - -> CHC1 + HC1
(Methylene (Chlorine) (Chloroform) (Hydrogen
Chloride) Chloride)
CHC13 + Cl - > CC14 + HC1
(Chloroform) (Chlorine) (Carbon (Hydrogen
Tetrachloride) Chloride)
A typical continuous-process flow diagram for the basic process is shown in
Fig. III-l.
Methanol is hydrochlorinated by feeding equimolar proportions of vaporized methanol
(Stream 1) and hydrogen chloride (Stream 2) at 180--200°C to the hydrochlorination
reactor. The reactor is packed with any one of a number of catalysts, including
alumina gel, cuprous or zinc chloride on activated carbon or pumice, or phosphoric
acid on activated carbon. The reactor is maintaned at a temperature of about
350°C. The reaction is exothermic. Methanol conversion of 95% is typical.
The reactor exit gases (Stream 3) enter the quench tower, where unreacted hydrogen
chloride and methanol are removed by water scrubbing. The discharge from the
quench tower (Stream 4) is stripped of virtually all dissolved methyl chloride
and most of the methanol, both of which are recycled to the hydrochlorination
reactor (Stream 5). The remaining aqueous solution from the stripper (Stream 6)
consists of dilute hydrochloric acid, which is used in-house or is sent to waste-
2
water treatment.
Methyl chloride from the quench tower (Stream 7) is fed to the drying tower,
where concentrated sulfuric acid removes residual water. The dilute sulfuric
2
acid effluent (Stream 8) is sold or is reprocessed.
A portion of the dried methyl chloride (Stream 9) is compressed, cooled, and
liquefied as product. The rest of the dried methyl chloride (Stream 10) is fed
to the chlorination reactor. The methyl chloride and chlorine (Stream 11) are
mixed in the reaction chamber to form methylene chloride and chloroform, along
with hydrogen chloride and a small amount of carbon tetrachloride. The reactions
are exothermic.
-------
MjO
DRYIWG,
TOWER
MEiHAUGL
H iDPQCWLORIUWIOM QUELMCW
REACTOR TOWER
CWLOROFORM
CHLORIDE CMLQBlD£
AKJO MEAVlfb (TO FURTHER
ME.TMYUEME
CHLORIDE TAKIK
DI'bTlLLATlOM
CHLOFMOE
CMLOROFORM
DISTILLATIOM
Fig. III-l. Process Flow Diagram for Manufacture of Chloromethanes by Methanol
Hydrochlorination and Methyl Chloride Chlorination Processes
-------
III-4
Hydrogen chloride is stripped from the condensed crude product and is recycled to
the methanol hydrochlorination reactor (Stream 12). The amounts of individual
products (methyl chloride, methylene chloride, chloroform, and by-product carbon
tetrachloride) determine whether sufficient hydrogen chloride by-product will be
available for operation of the reactor. The crude methylene chloride, chloro-
form, and carbon tetrachloride from the stripper (Stream 13) are transferred to a
storage tank, which feeds to the methylene chloride distillation column. The
methylene chloride product from this distillation (Stream 14) is fed to a day
tank, where inhibitors are added as stabilizers, and is then sent to methylene
chloride storage and loading. Bottoms from methylene chloride distillation
(Stream 15) go to the chloroform distillation column. The chloroform product
(Stream 16) is also taken to a day tank where inhibitors are added for control of
hydrochloric acid, and then sent on to storage and loading. Bottoms from chloro-
form distillation (Stream 17) consist of crude carbon tetrachloride, which is
stored for subsequent transfer to a separate carbon tetrachloride--perchloroethylene
process or is sold.
Process emissions originate at the vents used for purging inert gases from the
condensers associated with methyl chloride product recovery (Vent A), with dis-
tillation of methylene chloride (Vent B), and with distillation of chloroform
(Vent C), as shown in Fig. III-l. Fugitive emissions occur when Leaks develop in
valves, pumps, seals, or other equipment. Corrosion caused by the hydrogen
chloride and chlorine in the process can result in leaks, which hinder control of
fugitive emissions.
Emissions result from the storage of feed material, intermediates, products, and
by-products and from handling of the products.
Two potential sources of secondary emissions (K on Fig. III-l) are aqueous wastes
from the methyl chloride stripper and waste sulfuric acid from the methyl chloride
drying tower.
2. Process Variations
a. A process variation that would cause considerable impact on process emissions is
the purity of the chlorine feed that goes to the methyl chloride chlorination
reactor. Commercial liquid chlorine is reported to be typically 99.6 wt % pure,
-------
III-5
although amounts of impurities vary considerably.3 The model plant was based on
a 99.6 wt % pure chlorine feed, which can be achieved by liquefying and reva-
porizing the chlorine before it is used. Without this purification step there
will be additional inert gases, including carbon dioxide, oxygen, and hydrogen,
4
in the chlorine, which will increase emissions from the inert-gas purge vent
(Vent A, Fig. III-l).
b. Another process variation is the use of all .aethyl chloride produced in the manu-
facture of methylene chloride and chloroform. Inert gases introduced with the
chlorine must still be removed from the system.
c. An additional variation consists of the hydrochlorination reaction being carried
out in the liquid phase by refluxing the methanol at 150°C with hydrochloric acid
in the presence of dissolved zinc chloride.1 This change would have an insignifi-
cant effect on overall process emissions.
d. Variation of reaction conditions in the methyl chloride chlorination reactor
changes co-product and by-product yield ratios and therefore changes the relative
amounts of storage and loading emissions from each product stream.
e. When caustic scrubbing is used to remove residual hydrogen chloride from methyl
chloride before it is dried and from the crude product exiting the hydrogen
chloride stripper, chloromethanes will be carried from the process in the waste
caustic and will be emitted during treatment or disposal of the waste. Also,
drying columns are used for removing trace amounts of water from the methylene
chloride and chloroform product streams following distillation, thereby creating
other sources of secondary emissions.
f- Nitrogen is reported to be used for safety purposes during loading and unloading
of methyl chloride. This practice creates a source of methyl chloride emis-
sions.
g. Methane is used by one producer to maintain proper process pressure. Also, the
same producer uses tail gas chlorine from a caustic-chlorine plant to feed the
chlorination reactor.
-------
III-6
C. REFERENCES
1. D. W. F. Hardie, "Chlorocarbons and Chlorohydrocarbons," pp. 105, 106 in
Kirk-Othmer Encyclopedia of Chemical Technology, Vol. 5, 2d ed., Interscience,
New York, 1964.
2. F. D. Hobbs, IT Enviroscience, Inc., Trip Report for Visit to Vulcan Materials
Company, Geismar, LA, Jan. 4, 1978 (data on file at EPA, ESED, Research Triangle
Park, NC).
3. "Purity of Commercial Chlorine," Sect. 1, p. 2 in Hooker Chlorine, Bulletin
No. 125, Hooker Chemical Corp. (1965).
4. T. A. Liederbach, "Reducing Chlorine Loss in an Electrolysis Plant," Chemical
Engineering Progress 70(3), 64--6S (1974).
5. S. G. Lant, Diamond Shamrock, Belle, WV, letter to D. R. Goodwin, EPA, Apr. 3,
1978.
6. Personal communication between F. D. Hobbs, IT Enviroscience, Inc., and D. Denson,
Allied Chemical, Moundsville, WV, July 25, 1978, and Sept. 14, 1978.
*A reference located at the end of a paragraph usually refers to the entire para-
graph. If another reference relates to certain portions of the paragraph, the
reference number is indicated on the material involved. When the reference
appears on a heading, it refers to all the text covered by that heading.
-------
IV-1
IV. EMISSIONS FOR MODEL PLANTS
Emissions in this report are usually identified in terms of volatile organic
compounds (VOC). VOC are currently considered by the EPA to be those of a large
group of organic chemicals, most of which, when emitted to the atmosphere, partici-
pate in photochemical reactions producing ozone. A relatively small number of
organic chemicals have low or negligible photochemical reactivity. However, many
of these organic chemicals are of concern a.id may be subject to regulation by EPA
under Sections 111 and 112 of the Clean Air Act since there are associated health
or welfare impacts other than those related to ozone formation. It should be
noted that although methylene chloride is included in VOC emission totals in this
report, it does not, based on current research data, participate in ozone-forming
reactions to an appreciable extent.
A. METHANOL HYDROCHLORINATION AND METHYL CHLORIDE CHLORINATION
1. Model Plants*
Three model plants, with chloromethane capacities of 45,000, 90,000, and
180,000 Mg/yr, were selected to represent current domestic chloromethane manu-
facturing facilities. The percentages of total capacity for individual products
were selected to be 25% methyl chloride, 48% methylene chloride, 25% chloroform,
and 2% by-product carbon tetrachloride. For these percentages of the products
there is insufficient hydrogen chloride by-product from the methyl chloride
chlorination reaction for the methanol hydrochlorination reaction. Typical
raw-material, intermediate, and product storages were selected according to these
percentages of individual products. Each model plant was assumed to operate
8760 hr annually.**
The model methanol hydrochlorination and methyl chloride chlorination processes
shown in Fig. III-l reflect today's manufacturing and engineering technology.
*See page 1-2 for a discussion of model plants.
**Process downtime is normally expected to range from 5 to 15%. If the hourly
rate remains constant, the annual production and annual VOC emissions will be
correspondingly reduced. Control devices will usually operate on the same cycle
as the process. From the standpoint of cost-effectiveness calculations, the
error introduced by assuming continuous operation is negligible.
-------
IV-2
Single process trains are typical. The number of valves, pumps, and compressors
used for calculating fugitive emissions is typical for a plant of this type.
Characteristics of the model plants important to air dispersion are shown in
Appendix B.
2. Sources and Emissions
The process emissions estimated for the methanol hydrochlorination and methyl
chloride chlorination processes described li* this report and shown in Table IV-1
are based on the emissions reported in response to EPA's requests for information,
on a trip report on a visit to Vulcan, on a permit filed with the State of Texas
by Diamond Shamrock for a proposed chloromethanes plant, and on an understanding
of the process chemistry and yields.
b. Process Emissions -- Process emissions originate at the inert-gas purge vent and
at the methylene chloride and chloroform condensers, as described below:
Inert-gas purge vent — The chlorine feed to the methyl chloride chlorination
reactor contains inert gases, which must be vented. The model plants are based
on a chlorine feed that is purified (liquefied and revaporized) and is 99.6 wt %
pure. The inert gases will flow with the hydrogen chloride (Stream 12, Fig. III-l)
recycled to the hydrochlorination reactor from the hydrogen chloride stripper
following the methyl chloride chlorination reactor. These gases will remain in
the closed system until vented (Vent A, Fig. III-l), after compression and con-
densation of the methyl chloride.
Calculations based on 99.6 wt % pure chlorine for methyl chloride chlorination,
compression to a pressure of 5.07 X 10 Pa, and brine condensation of methyl
chloride at -20°C indicate emissions of 1.5 X 10 kg of methyl chloride per kg
of total chloromethanes produced. Variations in chlorine purity will signifi-
cantly affect emissions. For example, calculations based on 99.2 wt % pure
chlorine, with other conditions remaining identical, would double the methyl
chloride emissions, to 3.0 kg X 10"3, per kg of total chloromethanes produced.
Use of tail-gas chlorine would significantly increase the potential for emissions.
Sample calculations for determining the emissions indicated in Table IV-1 are
shown in Appendix C.
-------
Table IV-1. Total Uncontrolled VOC Emissions for Model Plants Producing Chloromethanes by
Ma=thanol Hydrochlorination and Methyl Chloride Chlorination
Total VOC Emissions for Model
Source
Inert-gas purge vent
Methylene chloride
condenser"
d
Chloroform condenser
e
In-process storage
Feed and product
storage6
e, f
By-product storage
Handling
Fugitive
Secondary
Stream
Designation
(Fig. III-l)
A
B
C
D
D
D
D
F
K
45,000-Mg/yr
Ratio0
(kg/Mg)
1.5
0.019
0.0056
0.55
1.07
0.03
0.36
2.9
0.020
6.45
Model Plant
Rate
(kg/hr)
7.85
0.10
0.029
2.80
5.48
0.14
1.84
14.9
0.10
33.2
90,000-Mg/yr
Ratio0
(kg/Mg)
1.5
0.019
0.0056
0.54
1.03
0.03
0.36
1.45
0.020
4.93
Model Plant
Rate
(kg/hr)
15.7
0.20
0.058
5.56
10.55
0.31
3.68
14.9
0.21
51.1
Plants
180,000-Mg/yr
Ratioc
(kg/Mg)
1.5
0.019
0.0056
0.53
1.02
0.03
0.36
0.7^
0.020
4.21
Model Plant
Rate
(kg/hr)
31.4
0.39
0.12
10.83
20.92
f-
0.59 J
7.36
14.9
0.41
86.9
Uncontrolled emissions are emissions from processes using no additional control devices other than those necessary
for economical operation.
Emissions include methyl chloride, methylene chloride, chloroform, carbon tetrachloride, dimethyl ether, and methanol.
°kg of emissions per Mg of chloromethane produced.
See ref. 1.
eSee ref. 2.
'Carbon tetrachloride plus "heavies" (or heavy ends).
-------
IV-4
Methylene chloride and chloroform condensers -- Two sources of process emissions
result from the buildup of inert gases in the condensers associated with methyl-
ene chloride and chloroform distillation (Vents B and C, Fig. III-l). These
gases must occasionally be purged to ensure efficient condenses performance.
~5
Emissions are reported to be 1.9 X 10 kg of methylene chloride per kg of total
chloromethanes produced for vent B and 5.6 X 10~ kg of chloroform per kg of
total chloromethanes produced for vent C. The temperature of the vented materials
was reported to be 43°C for both vents.
c. Fugitive Emissions — Process pumps, valves, and compressors are potential sources
of fugitive emissions. Each model plant is estimated to have 30 pumps handling
VOC (includes 15 spares), 750 process valves, including 25 pressure-relief valves,
and 2 compressors. All pumps have mechanical seals. The factors shown in Appen-
dix D were used to determine the fugitive emissions listed in Table IV-1.
d. Storage and Handling Emissions -- Emissions result from storage and handling of
methanol, methylene chloride, chloroform, and by-product crude carbon tetra-
chloride. Because methyl chloride has to be stored in pressure vessels, no
methyl chloride losses are involved except for emissions that would be classi-
fied as fugitive emissions. The sources of storage emissions for the model
plants are shown on the flow diagram in Fig. III-l (Source D). Storage tank
conditions for the model plants are given in Table IV-2. The uncontrolled storage
2
emissions in Table IV-1 were calculated with the emission, equations from AP-42,
with the tanks assumed to have fixed roofs and on the average to be half full,
with a diurnal temperature variation of 12°C. However, breathing losses were
divided by 4 to account for recent evidence indicating that the AP-42 breathing
loss equation overestimates emissions.
Emissions from loading methylene chloride and chloroform product into tank cars
2
and trucks were calculated with the equations from AP-42. Submerged loading
into clean tank cars and trucks was assumed for the emission calculations. No
emissions from loading carbon tetrachloride are included for the model plant,
since it is assumed that this impure by-product is transferred for further pro-
cessing in a carbon tetrachloride--perchloroethylene co-product facility. Another
assumption was that methyl chloride loading has a vapor return loop and therefore
creates no emissions.
-------
Table IV-2. Storage Requirements for Model Plants Producing Chloromethanes by
Hethanol Hydrochlorination and Methyl Chloride Chlorination
Storage Requirements for Model Plants
45,000-Mg/yr Model Plant
Material
Stored
Methanol
Methyl chloride
(2 identical
pressure- vessel
tanks)
Methylene chloride--
chloroform- -carbon
^
tetrachloride
Methylene chloride
(2 identical tanks)
Methylene chloride
Chloroform- -carbon
tetrachloride
Chloroform
(2 identical tanks)
Chloroform
Carbon tetrachloride
Tank
Size
(m3)
946
473
95
38
946
38
19
378
19
90,000-Mg/yr Model Plant
n-ii T • • j Tank
Bulk Liquid
Turnovers Temperature Turnovers
Per Year (°C) (m ) Per Year
24 20
13 20
,
6 35
216 30
17 20
h
6° 40
199 40
20 20
32 40
1890
946
189
76
1890
76
38
758
38
24
13
b
6
216
17
b
6
199
20
32
180,000-Mq /vr Model Plant
n 11 r • 'J Tank
Bulk Liquid
Temperature Turnovers
(°C) (m ) Per Year
20
20
35
30
20
40
40
20
40
3780
1890
378
151
3780
151
76
1510
76
24
13
b
6
216
17
b
6
199
20
32
Bulk Liquid
Temperature
20
20
H
f
35 w
30
20
40
40
20
40
Carbon tetrachloride plus "heavies."
Surge tanks are normally operated at constant level.
-------
IV-6
Secondary Emissions -- Secondary VOC emissions can result from the handling and
disposal of process waste liquid. For the model plants two potential sources of
secondary emissions from waste liquid are indicated on the flow diagram (Source K,
Fig. III-l): the aqueous waste discharge from the methanol hydrochlorination
process stripper and the sulfuric acid waste from the methyl chloride drying
tower.
Aqueous waste discharged from a properly designed and operated stripper, which
removes methanol and methyl chloride from the quench tower discharges for recycle
to the methanol hydrochlorination reactor, will contain some residual methanol,
but this methanol is not considered to be a source of secondary emissions because
it has a high solubility and a low volatility and is biodegradable.
Waste sulfuric acid from the methyl chloride drying tower is reported to contain
4 6
dimethyl ether, a by-product of the methanol hydrochlorination reaction. —
Based on the reported data— the waste acid is estimated to contain 4.2 X 10 kg
of dimethyl ether per kg of total chloromethane capacity, along with lesser
4
quantities of methanol and methyl chloride. One producer reported the waste
acid to contain 2 wt % dimethyl ether, 0.3 wt % methanol, and 0.1 wt % methyl
chloride. Based on these relative amounts of individual VOC components and the
estimated 4.2 X 10"3 kg of dimethyl ether per kg of total chloromethane capacity,
A -4
the waste acid is calculated to contain 6.3 X 10" kg methanol and 2.1 X 10 kg
of methyl chloride in addition to the dimethyl ether, for a total VOC content of
about 5.0 X 10~3 kg per kg of total chloromethane capacity. One producer reported
that a nitrogen purge on the waste acid tank results in emissions of 4.9 X 10 kg/hr
or about 1.9 X 10~5 kg of dimethyl ether combined with sulfuric acid per kg of
capacity, and unspecified but lesser quantities of free dimethyl ether and methyl
chloride.7 Another producer reported that the VOC in the waste acid is not
considered to be volatile and is oxidized during the acid recovery process.
Consequently, based on the above information, the model plant is estimated to
have 2.0 X 10"5 kg of secondary VOC emissions from the waste acid per kg of total
chloromethane capacity, with the remaining VOC oxidized during waste acid recovery.
It can be be noted that there are wide variations in the reported amounts of VOC
in the waste acid, the major source of estimated secondary VOC emissions.
-------
IV-7
B. OTHER PROCESSES
The methane chlorination and mixed hydrocarbon chlorinolysis processes to produce
chloromethanes will be covered in future reports. The only other process of
significance is the chlorination of carbon disulfide to produce carbon tetra-
chloride. Because of the negative growth of the carbon tetrachloride market this
process is becoming less important.
-------
IV-8
C. REFERENCES*
1. F. D. Hobbs, IT Enviroscience, Inc., Trip Report for Vulcan Materials Company,
Geismar, LA, Jan. 4, 1978 (on file at EPA, ESED, Research Triangle Park, NC).
2. C. C. Masser, "Storage of Petroleum Liquids," pp. 4.3-1 to 4.3-11 in
Supplement No. 7 for Compilation of Air Pollutant Emission Factors, AP-42, 2d
ed., EPA, Research Triangle Park, NC (April 1977).
3. E. C. Pulaski, TRW, letter dated May 30, 1979, to Richard Burr (EPA).
4. J. V. Muthig, Allied Chemical, Moundsville, WV, letter to D. R. Goodwin, EPA,
Mar. 31, 1978.
5. W. C. Strader, Ethyl Corporation, Baton Rouge, LA, letter to D. R. Goodwin, EPA,
Aug. 2, 1978.
6. Personal communication between D. A. Beck, EPA, Research Triangle Park, NC, and
J. Romans, Dow Corning, Carrolton, KY, Sept. 1, 1978.
7. R. L. Hatch, General Electric, Waterford, NY, letter to D. R. Goodwin, EPA,
Aug. 8, 1978.
*A reference located at the end of a paragraph usually refers to the entire paragraph
If another reference relates to certain portions of the paragraph, the reference
number is indicated on the material involved. When the reference appears on a
heading, it refers to all the text covered by that heading.
-------
V-l
V. APPLICABLE CONTROL SYSTEMS
A. EMISSION CONTROLS FOR MODEL PLANTS
1. Process Emissions
a.
Inert-Gas Purge Vent -- The absorption unit operation is a common concept for the
recovery of light hydrocarbons by their aL^trption in less volatile oils. A
similar operation conceptually can be used for absorption of methyl chloride in
chloroform for producers who manufacture the higher chloromethanes from methyl
chloride. Chloroform could be drawn from the process, chilled, and used as the
absorbent. The amount of VOC controlled would be dependent on the operating
temperature and pressure of the absorber. An operating temperature of -40°C
would result in a net control of VOC of about 98.8% at the design pressure of
5.1 X 105 Pa.
A preliminary design was developed of an adsorber system for cost estimating
purposes per the standard design methods described by Treybal.1 The design was
not optimized. The large difference in volatility between methyl chloride and
chloroform and the relatively small column size make the absorption column height,
within practical engineering limits, unimportant for either control efficiency or
system cost. The design parameters with the greatest effect on the control
efficiency are final gas temperature and pressure. As a general relationship the
total VOC emitted from the absorber will vary directly with the absolute pressure
of the system. Therefore the efficiency of 98.8% achievable at design pressure
and temperature will decrease to about 94% with a decrease to atmospheric pressure.
The absorber system may not be practical for use at existing plants. The limita-
tions on existing chloroform distillation capacity might disallow the use of this
control device without prohibitive equipment modifications. Further information
is listed in Appendix E, "Current Industry Considerations."
Carbon adsorption is not considered to be a practical alternative. Methyl chloride
has a very low loading factor on carbon due to its high volatility at practical
temperatures and pressures. Additionally, the feed stream is too concentrated in
-------
V-2
methyl chloride to be fed to a carbon column; therefore the feed stream would
have to be diluted with additional inert gases. Both factors would contribute to
a high cost per unit of methyl chloride removed.
Thermal oxidation also was not considered a sufficiently viable option to justify
a comparative study. Formation of hydrogen chloride during oxidation of methyl
chloride would necessitate corrosion-resistant materials of construction and the
addition of a scrubber for the vent gases from the oxidizer. Both would contrib-
ute to high capital and operating costs.
Controlled inert-gas purge-vent emissions for the 45,000- 90,000-, and
180,000-Mg/yr model plants are given in Table V-l.
b. Methylene Chloride and Chloroform Condensers -- Losses of VOC from the methylene
chloride and chloroform distillation vents (Vents B and C, Fig. III-l) constitute
less than 1% of emissions from the model plants. For the model plants these two
sources remain uncontrolled.
2. Fugitive Emissions
2
Control for fugitive sources is discussed in a separate EPA report. The controlled
fugitive emissions shown in Table V-l are based on the factors given in Appendix
D and on the assumption that any major leaks would be detected and repaired.
3. Storage Emissions
Condensation is used to control emissions from storage of chloromethanes. The
use of condensation is assumed to provide 80% control for model-plant storage
except for by-product storage, which is assumed to remain uncontrolled. Total
SOCMI VOC storage emissions are covered by a separate EPA report.
4. Handling Emissions
No unique handling controls are known to be practiced by the industry. Therefore
the handling emissions for the controlled model plants are the same as those for
the uncontrolled plants.
-------
Table V-l. Controlled VOC Emissions3 for 45,000-, 90,000-, and 180,000-Mg/yr
Model Plants Producing Chloromethanes by Methanol Hydrochlorination
and Methyl Chloride Chlorination
Steam
45,000-Mg/yr
VOC
Model Plant 90,000-Mg/yr
Designation Control Device Reduction Ratio*5
Source (Fig. III-l) or Technique {%) (kg/Mg)
Inert-gas purge vent
Methylene chloride
condenser
Chloroiorm condenser
In-process storage
Feed and product
storage
By-product storage
Handling
Fugitive
Secondary
Total
A
B
C
D)
o!
D
D
F
K
Absorber 98.8
None
None
Condenser 80.0
None
None
Detection and re- 67.5
pair of leaks
Hone
0
0
0
0
0
0
0
0
1
.019
.019
.0056
.32
.038
.36
.94
.020
.72
Rate Reduction
(kg/hr) (%)
0.
0.
0.
1.
0.
1.
4.
0.
8.
10 98.8
10
029
66 80.0
20
84
84 67.5
10
87
Emissions
Model Plant 180,000-Mq/vr Model
Ratio b
(kq/mq)
0
0
0
0
0
0
0
0
1
.019
.019
.0056
.31
.048
.36
.47
.020
.25
Rate Reduction
(kg/hr) (i)
0.20 98.8
0
0
3
0
3
4
0
12
.20
.058
.22 80.0
.49
.68
.84 67.5
.21
.9
Ratiob
(kg/Mg)
0.019
0
0
0
0
0
0
0
1
.019
.0056
.31
.042
.36
.24
.020
.02
Plant
Rate
0.40
0.
0.
6.
0.
7.
4
0.
20.
39
12
35
86
If,
84
41
7
f
( l)
a . l^vKTU-llv. ' ~ ~ — — -
kg of emissions per Mg of chloromethane produced.
Carbon tetrachloride plus "heavies".
dimethyl ether, and methanol.
-------
V-4
5. Secondary Emissions
Secondary emissions originating from the waste sulfuric acid from the methyl
chloride drying tower are less than 1% of emissions from the model plants and
therefore are not controlled. Emissions from secondary sources are discussed in
4
a separate EPA report.
-------
V-5
B. REFERENCES
1. R. E. Treybal, Mass-Transfer Operations, chaps. 6 and 8, McGraw-Hill, New York,
1955.
2. D. G. Erikson and V. Kalcevic, IT Enviroscience, Inc., Fugitive Emissions
(September 1980) (EPA/ESED report, Research Triangle Park, NC).
3. D. G. Erikson, IT Enviroscience, Inc., Storage and Handling (September 1980)
(EPA/ESED report. Research Triangle Park, NC).
4. J. Cudahy and R. L. Standifer, IT Enviroscience, Inc., Secondary Emissions
(June 1980) (EPA/ESED report. Research Triangle Park, NC).
*A reference located at the end of a paragraph usually refers to the entire paragraph.
If another reference relates to certain portions of the paragraph, the reference
number is indicated on the material involved. When the reference appears on a
heading, it refers to all the text covered by that heading.
-------
VI-1
VI. IMPACT ANALYSIS
A. CONTROL COST IMPACT
This section presents estimated costs and cost-effectiveness data for control of
VOC emissions resulting from the production of chloromethanes. Details of the
model plants are given in Sect. III. Emission sources and emissions are dis-
cussed in Sect. IV.
Capital cost estimates represent the total investment required for the purchase
and installation of all new equipment needed for a complete emission control sys-
tem performing as defined for a typical location. These estimates do not include
the cost of production lost during installation of control systems or the cost of
research and development.
The bases for annual cost estimates for the control devices include utilities,
raw materials, maintenance supplies and labor, recovery credits, capital charges,
and miscellaneous recurring costs such as taxes, insurance, and administrative
overhead. (Manpower costs are minimal and therefore are not included.) The cost
factors that were used are itemized in Table VI-1. Recovery credits are based on
raw-material values. Annual costs are for a 1-year period beginning December
1979.
1. Process Emissions
The major process emission source is the inert-gas purge vent (Vent A, Fig. III-l).
The estimated installed capital costs of an absorption system for controlling emis-
sions from this vent are $65,700, $82,400, and $118,600 for the 45,000-, 90,000-,
and 180,000-Mg/yr total capacity model plants, respectively (see Table VI-2).
Utilities, raw materials, fixed costs, and recovery credits vary with the plant
capacity. Installed capital cost, net annual cost, and cost-effectiveness varia-
tions with capacity are shown in Figs. VI-1 to VI-3. The absorbent material for
methyl chloride in the emissions is chloroform from the process. Annual absorbent
material costs are based on the raw-material value of the chloroform (methyl chlo-
ride and chlorine) lost from the absorption system. Recovery credits are based
on the raw-material value of the methyl chloride (methanol and hydrogen chloride),
which is recycled to the process.
-------
VI-2
Table VI-1. Cost Factors Used in Computing Annual Costs
Item Factor
Utilities
Electricity $8.33/GJ
Cooling water $0.026/m~'
Operating time 8,760 hr/yr
Operating labor Minor; not considered
Fixed costs
Maintenance labor plus materials, 6%
Capital recovery, 18% (10 yr life @ 12% interest) 29% of installed
Taxes insurance, administration, 5%
Recovery credits*
Methyl chloride $337/Mg
Chloroform $344/Mg
Based on raw-material costs in "Current Prices of Chemicals and Related
Materials," Chemical Marketing Reporter, April 1, 1980.
-------
Table VI-2. Absorber System Control Cost Summary
December 1979 installed capital
Utilities
Raw materials* (chloroform loss)
Fixed costs
Recovery credits* (methyl chloride recovery)
Net annualized cost (savings)
Total VOC reduction
Cost effectiveness (savings/Mg)
45,000 Mg/yr
$65,700
956
226
19,053
(23,056)
(2,821)
68 Mg
($41/Mg)
Model Plant
90,000 Mg/yr
$82,400
1,854
452
23,896
(46,112)
(19,910)
13 Mg
($146 /Mg)
180,000 Mg/yr
$118,600
3,707
904
34,394
(92,224)
(53,219)
272 Mg
($195/Mg)
I
on raw-material costs. w
-------
December 1979 Installed Capital Cost ($1000)
o
Ul
o
00
o
V£>
O
H1
O
O
O
o
H
I
Model Plant ttl
ft 0)
I rt
(Ji
O
U3 (-1
(I)
T) CL
p
M O
rt
n
3 1 '
rt
n
M O
3 w
Klft
M <
H- W
O
3 t)
o £
O 3
o
H-
rt
oo
o
o
o
Model Plant #2
O pj
M hO
(1)
o
H-
rt
HI
O
Model Plant #3
M
O
o
-------
o
o
o
8.
c
•H
g
-P
0)
30 40 50 60 80 100
Plant Capacity (Gg/yr)
200
300
Fig. VI-2. Net Annual Savings vs Plant Capacity for
Inert-Gas Purge Vent Emission Control
-------
VI-6
300
s
co-
en
in
0)
I
4-1
O
OJ
W
-P
in
o
u
200 —
100 -
30
40
50 60 70 80 90 100
Plant Capacity (Gg/yr)
200
Fig. VI-3. Cost Effectiveness vs Plant Capacity for
Inert-Gas Purge Vent Emission Control
-------
VI-7
Other process emissions from the methylene chloride and chloroform condensers
(Vents B and C, Fig. III-l) remain uncontrolled.
2. Storage
Model-plant storage emissions can be controlled by use of condensation as described
in a separate EPA report.
3. Handling Sources
No control system has been defined for the emissions from handling sources in the
model plants.
4. Fugitive Sources
A control system for fugitive sources is defined in Appendix C. Fugitive emissions
and their applicable controls are covered in a separate EPA report.
5. Secondary Sources
No control system has been defined for secondary emissons from the model plants.
B. ENVIRONMENTAL AND ENERGY IMPACTS
Table VI-3 shows the environmental impact of reducing VOC emissions by applica-
tion of the described control systems to the model plants using the methanol hydro-
chlorination and methyl chloride chlorination processes. Individual impacts are
discussed below.
1. Inert-Gas Purge Vent
The absorber for the inert-gas purge vent reduces net VOC emissions by 68, 136,
and 272 Mg/yr for the 45,000-, 90,000-, and 180,000-Mg/yr total capacity model
plants, respectively. The net VOC reduction is the reduction in methyl chloride
emissions minus chloroform emissions from the absorber. The emission reduction
would be equivalent to a reduction of 629 Mg of VOC for all projected domestic
1979 production of methyl chloride, methylene chloride, and chloroform by producers
using the combined methanol hydrochlorination and methyl chloride chlorination
process. This reduction is based on the assumption of the emission characteristics
of the composite industry being equivalent to that of the model plants. A small
negative environmental impact would result from the losses of chloroform from the
absorber (9.6 X 10 kg of chloroform emissions per kg of methyl chloride recovered)
-------
Table VI-3. Environmental Impact of VOC Emissions Control for Methanol
Hydrochlorination and Methyl Chloride Chlorination Plants with
Capacities of 45,000, 90,000, and 180,000 Mg/yr
Emission
Source
Stream
Designation
(Fig. III-l)
Control
Device or
Technique
Inert-gas
purge vent
Methyl chloride
condenser
Chloroform
condenser
In-process
storage
Feed and product
storage
By-product
storage
Handling
Fugitive
Secondary
Totalb
A
B
D
D
F
K
Emission Reductions
45,OOP-Mg/yr Plant 90,OOP-Mg/yr Plant 180,000-Mg/yr Plant
(Mg/yr) (%_) (Mg/yr) (%) (Mg/yr) (%)
Absorber
None
None
Condenser
None
None
Detection and correc-
tion of leaks
None
68.0
58.0
88.1
223.5
98.8
80.0
67.5
88.2
136.0
113.0
88.1
388.6
98.8
80.0
67.5
88.0
272.0
223.0
88.1
717.1
98.8
80.0 o>
67.5
88.0
aCarbon tetrachloride plus "heavies."
bThe total percentage of emission reduction is calculated from the total uncontrolled emission listed in Table IV-1
and the total controlled emission listed in Table V-l.
-------
VI-9
2. Other Emissions (Storage and Handling, Fugitive, and Secondary)
Control methods described for these sources are condensation for in-process and
final-product storage tank vents and leak correction for fugitive emissions.
Application of these controls results in VOC reduction of about 146, 201, and
311 Mg/yr for the 45,000-, 90,000-, and 180,000-Mg/yr total capacity model plants,
respectively. The emission reduction would be equivalent to about 929 Mg/yr for
the producers using the combined methanol hydrochlorination and methyl chloride
chlorination process, based on the assumption that the composite industry emissions
are equivalent to the 90,000-Mg/yr model plant emissions.
-------
VI I-1
VII. PRODUCT ASSESSMENT
A. SUMMARY
Three of the chloromethanes -- methyl chloride, methylene chloride, and chloro-
form -- are produced by the combined processes of methanol hydrochlorindtion and
methyl chloride chlorination. Methanol hydrochlorination produces methyl chloride,
which is chlorinated to methylene chloride, chloroform, and by-product carbon
tetrachloride. The by-product carbon tet.acriloride generally is not purified
directly into product by industry.
The chloromethanes produced by the methanol hydrochlorination and methyl chloride
chlorination processes are showing broad variations in consumption patterns. As
is shown in Sect. II, methyl chloride consumption is expected to increase at an
annual rate of about 5%, methylene chloride consumption at 11%, and chloroform
consumption 8%.
Emission sources and control levels for methanol hydrochlorination and methyl
chloride chlorination model plants are summarized in Table VII-1. Emission pro-
jections for domestic industry in 1979 are based on the following assumptions:
(1) 50% of the methyl chloride, 70% of the methylene chloride, and 75% of the
chloroform produced in 1979 were based on these combined processes, and (2) emis-
sion rates for the industry were equivalent to those for the 90,000-Mg/yr total-
capacity model plant. Calculations based on these assumptions indicate VOC emis-
sions of 236 kg/hr, with all plants uncontrolled, and 60 kg/hr, with the plants
controlled. It is estimated that about 36% of the VOC emissions for the domestic
methanol hydrochlorination and methyl chloride chlorination industry are controlled.
This is a weighted average of the individual estimated projections:
VOC Controlled (%)
Handling, fugitive, and secondary 20
In-process and by-product storage 10
Feed and product storage 60
Process 70
On this basis the current emissions from the domestic chloromethanes industry
using the combined methanol hydrochlorination and methyl chloride chlorination
processes are about 172 kg/hr.
-------
VII-1
VII. PRODUCT ASSESSMENT
A. SUMMARY
Three of the chloromethanes -- methyl chloride, methylene chloride, and chloro-
form — are produced by the combined processes of methanol hydrochlorination and
methyl chloride chlorination. Methanol hydrochlorination produces methyl chloride,
which is chlorinated to methylene chloride, chloroform, and by-product carbon
tetrachloride. The by-product carbon tetiachioride generally is not purified
directly into product by industry.
The chloromethanes produced by the methanol hydrochlorination and methyl chloride
chlorination processes are showing broad variations in consumption patterns. As
is shown in Sect. II, methyl chloride consumption is expected to increase at an
annual rate of about 5%, methylene chloride consumption at 11%, and chloroform
consumption 8%.
Emission sources and control levels for methanol hydrochlorination and methyl
chloride chlorination model plants are summarized in Table VII-1. Emission pro-
jections for domestic industry in 1979 are based on the following assumptions .-
(1) 50% of the methyl chloride, 70% of the methylene chloride, and 75% of the
chloroform produced in 1979 were based on these combined processes, and (2) emis-
sion rates for the industry were equivalent to those for the 90,000-Mg/yr total-
capacity model plant. Calculations based on these assumptions indicate VOC emis-
sions of 236 kg/hr, with all plants uncontrolled, and 60 kg/hr, with the plants
controlled. It is estimated that about 36% of the VOC emissions for the domestic
methanol hydrochlorination and methyl chloride chlorination industry are controlled.
This is a weighted average of the individual estimated projections:
VOC Controlled (%)
Handling, fugitive, and secondary 20
In-process and by-product storage 10
Feed and product storage 60
Process 70
On this basis the current emissions from the domestic chloromethanes industry
using the combined methanol hydrochlorination and methyl chloride chlorination
processes are about 172 kg/hr.
-------
Table VII-1. Summary of Emissions from Model Plants Producing Chloromethanes by
Methanol Hydrochlorination and Methyl Chloride Chlorination
Emission Rates (kg/hr)
45,000-Mg/yr Model Plant
Emission Source
Inert-gas purge vent
Methylene chloride condenser
Chloroform condenser
In-process storage
Feed and product storage
By-product storage*
Handling
Fugitive
Secondary
Total
Uncontrolled
7.85
0.10
0.029
2.80 \
5.48 J
0.14
1.84
14.9
0.10
33.2
Controlled
0.10
0.10
0.029
1.66
0.20
1.84
4.84
0.10
8.87
90,000-Mg/yr Model Plant
Uncontrolled
15.7
0.20
0.058
5.56 I
10.55 1
0.31
3.68
14.9
0.21
51.1
Controlled
0.20
0.20
0.058
3.22
0.49
3.68
4.84
0.21
12.9
180,000-Mg/yr Model Plant
Uncontrolled
31.4
0.39
0.12
10.83 \
20.92 J
0.59
7.36
14.9
0.41
86.9
Controlled
0.40
0.39
0.12
6.35
0.86
<
7.36 £
I
4.84 M
0.41
20.7
aCarbon tetrachloride plus "heavies".
-------
VII-3
In addition to the emissions listed above one producer predominantly using tail-
gas chlorine from a chlorine-caustic plant to feed the chlorination reactor
reported process emissions averaging about 80 kg/hr.
The predominant emission points are the inert-gas purge-vent and storage tanks.
The inert-gas purge vent can be controlled by use of a chilled chloroform absorber
system which if operated at -40°C would result in a net VOC reduction of 98.8%.
Storage emissions can be controlled by condensation.
-------
VII-4
B. REFERENCES*
1. J. V. Muthig, Allied Chemical, Moundsville, WV, letter to D. R. Goodwin, EPA,
Mar. 31, 1978.
2. Personal communcations between F. D. Hobbs, IT Enviroscience, Inc., and D Denoon,
Allied Chemical, Moundsville, WV, Sept. 14, 1978.
*A reference located at the end of a paragraph usually refers to the entire
paragraph. If another reference relates to certain portions of the paragraph,
the reference number is indicated on the material involved. When the reference
appears on a heading, it refers to all the text covered by that heading.
-------
APPENDIX A
Table A-l. Physical Properties of Chloromethane Compounds
Chemical
Name
Chloromethane
Dichlorome thane
d
Chloroform
Carbon
tetrachloride
"Methyl Chloride,"
Kolecular Molecular
Synonym Formula Weight
Methyl chloride CH3C1 50.49
Methylene CH2C12 84.93
chloride
methylene
dichloride
Trichloromethane, CHC1 119.39
methenyl
chloride
Tetrachloromethane, CC14 153.82
perchloromethane ,
methane tetra-
chloride
p. AIII-174 in Scoring of Organic Air Pollutants
edited by J. Dorigan et al., MTR-7248, Rev. 1, Appendix III, MITRE
P. E. Liley et al.
Physical
State
Gas
Liquid
Liquid
Liquid
Vapor
Vapor Specific
Pressure Gravity
5.0 atm 1.78
at 22°Cb
435.8 mm 2.93
Hg at
25 "C
200 mm 4.12
Hg at
25.9°C
115.2 mm 5.32
Hg at
25°C
Physical Properties
Boiling Melting
Point Point
-24.2°C -97.73°C 0
at 760
mm Hg
40°C at -95.1°C 1
760 mm
Hg
*
61.26°C -63.5°C 1
76.54°C -22.99°C 1
at 760
mm Hg
Chemistry, Production and Toxicity of Selected Synthetic
Density
.9159 g/ml
at 20°C/4°C
.3266 g/ml
15 2Q'C/4°C
.49845 g/ml
at 15 °C
.5490 g/ml
at 20°C/4°C
Solubility
in Water
4.9 g/litcr
Slight
8.0 g/liter
Insoluble
Organic Chemicals (f-n) ,
Corp. (September 1976).
, "Physical and Chemical Data," Sect. 3, Table 3-9, in Chemical Engineers' Handbook,
4th ed. , edited ' y R. H.
Perry et al . ,
McGraw-
Hill, Hew York, 1963.
c"tlethylene Chloride," ibid. , p. AIII-186.
"Chloroform," ibid., Appendix I, p. AI-264.
"Carbon Tetrachloride," ibid., p. AI-222.
-------
B-l
APPENDIX B
Table B-l. Air -Dispersion Parameters for 90,000 Mg/yr
Model Plant Using Methanol Hydrochlorination and
Methyl Chloride Chlorination Processes
a
Emission Source
Uncontrolled
Inert-gas purge vent
Methylene chloride distillation vent
Chloroform distillation vent
Methanol feed storage
Crude product storage
Methylene chloride day storage (2)
Crude chloroform storage
Chloroform day storage (2)
Methylene chloride product storage
Chloroform product storage
Carbon tetrachloride storage
Handling
Fugitive
Secondary
Controlled
Inert-gas purge vent absorber
Methylene chloride distillation vent
Chloroform distillation vent
In-process and product storage
Carbon tetrachloride storage
Handling
Fugitive
Secondary
Emission
rate
(g/sac)
4.36
0.056
0.016
0.29
0.23
0.42
0.07
0.21
2.02
0.62
0.14
1.02
4.14
0.058
0.056
0.056
0.016
0.89
0.14
1.02
1.34
0.058
Height
(m)
11.0
11.0
11.0
14.63
7.32
4.38
4.88
2.44
14.63
9.76
2.44
11.0
11.0
11.0
14.6
2.44
One except where noted otherwise. At process conditions 05 5.
conditions of 2.07 X 10 Pa immediately
venting. Fugitive emissions are evenly
prior to venting. At
distributed
Diameter
!' ;
0.025
0.025
0.025
12.80
5.73
4.57
4.45
4.45
12.80
9.94
4.45
0.025
0.025
0.025
0.025
4.45
.07 X 10S Pa
Air-Dispersion Parameters
Flow Discharge
Discharge Rate Velocity
Temp. (K) (m3/sec) (m/sec)
b
253 1.55 X 10 1.5
316 9.92 X 10~6 0.020
316 3.64 X 10"6 0.0074
293
308
303
313
313
293
293
313
Ambient
Ambient to
623
Ambient
f
233 1.10 X 10 3.6
316 9.92 X 10-6^ °-°20
316 1.64 X 10"° 0.0074
293
313
Ambient
Ambient to
623
Ambient
immediately prior to venting. At -orocess
process conditions of 1.17 X 10 Pa immediately prior to
over a rectangular area of about 40 X 80 m. ^At process conditions
of 5.07 X 10 Pa immediately prior to venting.
-------
C-l
APPENDIX C
SAMPLE CALCULATIONS
Inert-gas purge-vent emissions were calculated for the methanol hydrochlorination
and methyl chloride chlorination processes from the information given in
Tables C-l, C-2, and C-3.
-------
Table C-l. Stoichiometry and Assumed Product Yield for Determining
Chlorine Requirements for Model Plants
Product
Methyl chloride
Methylene chloride
Chloroform
C12 Product
Weight Fraction of Ratio
Qt^i'-VrinmPtry Total Capacity Calculation (kg/Mg)
CH_OH + HC1
o
CH Cl + Cl
(70.91) *
CH Cl + 2C10
3 ^
(70.91)
CH Cl + 3C1
(70.91)
> CH3C1 + H2°
CH2C12 + Cl
(84.93)
CHC1_ + 2HC1
> o
(119.39)
CC1 . + 3HC1
(153.82)
0.25
0.48 70.91 X 0.48 X 1000
84.93
0.25 70.91 X 2 X 0.25 X 1000
119.39
0.02 70.91 X 3 X 0.02 X 1000
153.82
400
297
28
725
O
*Numbers in parentheses are molecular weights.
-------
C-3
Table C-2. Ratios of Inert Gases in Chlorine to Total
Chloromethanes Produced in Model Plants
Ratios
Assumptions
Calculations
(kg/Mg)a (kg molos/Mg)b
99.6 wt % chlorine purity, 0.4
wt % inert gases; molecular
weight of inert gases, 29
725 X 0.004
0.996
2.9
2.9
0.1
j
-------
D-l
APPENDIX D
FUGITIVE-EMISSION FACTORS*
The Environmental Protection Agency recently completed an extensive testing
program that resulted in updated fugitive-emission factors for petroleum re-
fineries. Other preliminary test results suggest that fugitive emissions from
sources in chemical plants are comparable to fugitive emissions from correspond-
ing sources in petroleum refineries. Therefore the emission factors established
for refineries are used in this report to esti.nate fugitive emissions from
organic chemical manufacture. These factors are presented below.
Uncontrolled
Emission Factor
Controlled
Emission Factor0
Source
Pump seals
Light-liguid service
Heavy-liquid service
Pipeline valves
Gas/vapor service
Light-liquid service
Heavy-liquid service
Safety/relief valves
Gas/vapor service
Light-liquid service
Heavy-liquid service
Compressor seals
Flanges
Drains
(kg/hr)
0.12
0.02
0.021
0.010
0.0003
0.16
0.006
0.009
0.44
0.00026
0.032
(kg/hr)
0.03
0.02
0.002
0.003
0.0003
0.061
0.006
0.009
0.11
0.00026
0.019
"Based on monthly inspection of selected equipment; no inspection ot
heavy-liquid equipment, flanges, or light-liquid relief valves;
10,000 pprnv VOC concentration at source defines a leak; and 15 days
allowed for correction of leaks.
Light liquid means any liquid more volatile than kerosene.
ARadian Corp., Emission Factors and Frequency of Leak Occurrence for Fittings
in Refinery Process Units, EPA 600/2-79-044 (February 1979).
-------
E-l
APPENDIX E
EXISTING PLANT CONSIDERATIONS
Information was gathered during two site visits and through responses by
industry to requests for information.
Allied, Moundsville, WV
Production is based mostly on hydrochlorination of methanol and chlorination of
the resulting methyl chloride to the high,-., -hloromethanes. A small amount
(about 5%) of the capacity is based on methane, which basically is used for
pressure control. The chlorine used in methyl chloride chlorination is tail-gas
chlorine and therefore contains considerably more inert gases than are contained
in the purified chlorine assumed to be used in the model plants. Condensation
is used to reduce inert-gas purge-vent emissions by about 50%.1'2
Diamond Shamrock, Belle, WV
Production is based on the combined methanol hydrochlorination and methyl
chloride chlorination for production of the higher chloromethanes. Two separate
river-water condensation systems are used for emissions control. One system is
used on multiple storage tank vents and separation and purification area process
vents; 12 vents are involved. The other system is used for control of emissions
from two light-ends columns and emissions resulting from the use of inert gas
(nitrogen) during product and raw-material loading and unloading.3
Dow, Plaquemine, LA
A mixture of chloromethanes is produced by continuous hydrochlorination of
methanol and chlorination of methyl chloride in a single train. Caustic
scrubbing is used to control effluent losses of hydrogen chloride and chlorine.
Fugitive emissions are controlled by continuous gas chromatographic monitoring
of air samples collected at numerous points throughout the facility. Refrigerated
condensers were reported to be planned for installation on methanol, methylene
chloride, and chloroform storage tanks.4
Ethyl, Baton Rough, LA
Methyl chloride is produced from hydrochlorination of methanol. A flare serves
the entire process, primarily for control of emergency releases from process
safety valves.
-------
E-2
General Electric, Waterford, NY
Methyl chloride is produced by hydrochlorination of methanol. A condenser is
used to control intermittent emissions (occurring about 75 hr each year).
Union Carbide, South Charleston, WV
Methyl chloride is produced from hydrochlorination of methanol with no controls
7
except for those necessary for good engineering operation.
Vulcan, Geismar, LA
Methanol is hydrochlorinated to methyl chloride, and all methyl chloride is
chlorinated to produce the higher chloromethanes. There are no process emission
control devices. A refrigerated vent condenser is used for control of methylene
chloride product storage emissions and is planned for control of chloroform
• • 8
storage emissions.
Retrofitting Controls
The primary difficulty associated with retrofitting may be in finding space to
fit the control device into the existing plant layout. Because of costs associated
with this difficulty it may be appreciably more expensive to retrofit emission
control systems in existing plants than to install a control system during
construction of a new plant.
The absorption unit conceptualized for control of inert-gas purge vent emissions
could be especially difficult to retrofit. It should be considered only in
plants producing the higher chloromethanes because chloroform is proposed as
the absorbent. Chloroform distillation capacity should also be considered at
existing facilities prior to contemplation of this control device.
-------
E-3
B. REFERENCES*
1. J. V. Muthig, Allied Chemical, Moundsville, WV, letter to D. R. Goodwin,
EPA, Mar. 31, 1978.
2. Personal Communication between C. McCartel, Allied Chemical, and F. D. Hobbs,
IT Enviroscience, Aug. 4, 1978.
3. S. G. Lant, Diamond Shamrock, Belle, WV, letter to D. R. Goodwin, EPA, Apr. 3,
1978.
4. F. D. Hobbs, IT Enviroscience, Trip Report for Dow Chemical Company, Plaquemine,
LA, November 17, 1977 (on file at EPA, ESED, Research Triangle Park, NC).
5. W. C. Strader, Ethyl Corporation, Baton Rough, LA, letter to D. R. Goodwin,
EPA, Aug. 2, 1978.
6. R. L. Hatch, General Electric Company, Waterford, NY, letter to D. R. Goodwin,
EPA, Aug. 8, 1978.
7. F. D. Bess, Union Carbide, South Charleston, WV, letter to L. B. Evans, EPA,
Aug. 3, 1978.
8. F. D. Hobbs, IT Enviroscience, Trip Report for Vulcan Materials Company,
Geismar, LA, Jan. 4, 1978 (on file at EPA, ESED, Research Triangle Park, NC).
^Usually, when a reference is located at the end of a paragraph, it refers to
the entire paragraph. If another reference relates to certain portions of
that paragraph, that reference number is indicated on the material involved.
When the reference appears on a heading, it refers to all the text covered by
that heading.
-------
TECHNICAL REPORT DATA
(fleasc read Instructions on the reverse before completing)
EPA-450/3-80-028a
4 TiTw£ AND SUBTITLE
Organic Chemical Manufacturing
Volume s Selected Processes
3. RECIPIENT'S ACCESSION NO
5. REPORT DATE
December 1980
6. PERFORMING ORGANIZATION CODE
J. A. Key
F. D. Hobbs
C. W. Stuewe
D. M. Pitts
R. L. Standifer
8. PERFORMING ORGANIZATION REPORT NO.
—•" ' —
9. PERFORMING ORGANIZATION NAME AND ADDRESS
IT Enviroscience, Inc.
9041 Executive Park Drive
Suite 226
Knoxville, Tennessee 37923
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-02-2577
12' ^fl^5?""^ fGENCY NAME AND ADDRESS
DAA for Air Quality Planning and Standards
Office of Air, Noise, and Radiation
U.S. Environmental Protection Agency
Research Triangle Park, North Carolina 27711
13. TYPE OF REPORT AND PERIOD COVERED
Final
15. SUPPLEMENTARY NOTES
14. SPONSORING AGENCY CODE
EPA/200/04
16 ABSTRACT
HP?n lirll P H§ *
Section U9 ?n
°r
standards under Section 111 of
standards ^ hazardous air pollutants
e organic compound emissions (VOC) from organic
^
produrtl!
PreSe"tS 1n-depth studfes of several maJ°r organic chemical
17.
KEY WORDS AND DOCUMENT ANALYSIS
DESCRIPTORS
;-,£-, DISTRIBUTION STATEMENT
Unlimited Distribution
EP/. Form 222C-! (Rev. 4-77)
b.IDENTIFIERS/OPEN ENDED TERMS
c. COS AT l Field, 'Group
13B
19 SECURITY CLASS (Tins Report)
Unclassified
21. NO. OF PAGES
363
,22. PRICE
PREVIOUS ED'TION 'S OBSOLETE
-------
|