SOURCE CATEGORY SURVEY
FOR THE
ACRYLONITRILE INDUSTRY
DRAFT
Prepared for:
OFFICE OF AIR QUALITY PLANNING AND STANDARDS
U.S. ENVIRONMENTAL PROTECTION AGENCY
RESEARCH TRIANGLE PARK, NORTH CAROLINA
Contract No. 68-02-3061
July 1981
Prepared by:
ENERGY AND ENVIRONMENTAL ANALYSIS, INC,
1111 North 19th Street
Arlington, Virginia 22209
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TABLE OF CONTENTS
1. SUMMARY 1-1
1.1 Monomer Production 1-1
1.2 Acrylic Fiber Production 1-4
1.3 ABS/SAN Resin Production 1-6
1.4 NBR Production 1-9
1.5 Existing State and Federal Regulations 1-11
1.6 Preferred Method of Sampling and Analysis of AN Emissions . 1-12
2. INTRODUCTION 2-1
3. DESCRIPTION OF INDUSTRY. 3-1
3.1 Source Category 3-1
3.1.1 Monomer Production 3-1
3.1.2 Acrylic Fiber Production 3-4
3.1.3 ABS/SAN Resins 3-7
3.1.4 NBR Elastomers 3-14
3.1.5 Other Uses of AN . 3-17
3.2 Growth in AN Production 3-18
3.2.1 Acrylic Fibers 3-18
3.2.2 ABS/SAN Resins 3-20
3.2.3 NBR Elastomers 3-20
3.2.4 Other Areas 3-20
3.3 Process Description 3-21
3.3.1 AN Monomer 3-21
3.3.2 Acrylic Fibers 3-25
3.3.3 ABS/SAN 3-30
3.3.3.1 Emulsion Process 3-32
3.3.3.2 Suspension Process 3-33
3.3.3.3 Continuous Mass (Bulk) Process 3-35
3.3.3.4 SAN by Emulsion Process 3-37
3.3.4 NBR Elastomers 3-37
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TABLE OF CONTENTS (Cont'd)
Page
4. AIR EMISSIONS DEVELOPED IN SOURCE CATEGORY 4-1
4.1 Plant and Process Emissions 4-1
4.1.1 AN Monomer 4-4
4.1.2 Acrylic Fibers 4-4
4.1.3 ABS/SAN Resins 4-9
4.1.4 NBR Elastomers 4-9
5. EMISSION CONTROL SYSTEMS 5-1
5.1 Storage and Fugitive Emission Controls 5-1
5.1.1 Current Controls 5-1
5.1.1.1 Process Fugitive Emission Controls 5-1
5.1.1.2 Storage Tank Controls 5-2
5.1.1.3 Transfer and Handling Controls 5-2
5.1.2 Available Control. 5-3
5.1.2.1 Fugitives 5-3
5.1.2.2 Storage Tanks 5-3
5.1.3 Loading Facilities 5-8
5.2 Process Controls 5-9
5.2.1 AN Monomer 5-9
5.2.2 Acrylic Fibers 5-13
5.2.3 ABS/SAN Resins 5-18
5.2.4 NBR Elastomers 5-20
6. EMISSION DATA 6-1
6.1 Availability of Data 6-1
6.2 Sample Collection and Analysis 6-1
7. STATE AND LOCAL REGULATIONS 7-1
-11-
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LIST OF TABLES
Page
1-1 AN Emission Estimates from Monomer Plants 1-3
1-2 AN Emission Estimates from Fiber Plants 1-5
1-3 AN Emission Estimates from ABS/SAN Plants 1-7
1-4 AN Emission Estimates from NBR Plants 1-10
2-1 List of Recipients of Section 114 Letters 2-3
2-2 List of Plants Visited 2-4
3-1 1979 AN Production and Consumption for End Use Categories ... 3-2
3-2 Current AN Capacity 3-3
3-3 AN Production, Capacity, and Capacity Utilization, 1969-1979. . 3-5
3-4 Acrylic Fiber Producers and Capacities ' 3-6
3-5 Acrylic Fiber Production and Capacity Utilization 3-8
3-6 End Use of Acrylic and Modacrylic Fibers 3-9
3-7 ABS/SAN Producers and Capacities 3-11
3-8 ABS Production and Capacity Utilization 3-12
3-9 Trends in Domestic Consumption of ABS Resins by End User,
1973-1979 3-13
3-10 Nitrile Elastomer Producers and Capacities 3-15
3-11 Nitrile Elastomer Production and Capacity Utilization 3-16
3-12 Estimated Growth in AN End Markets and AN Demand From 1980
to 1985 3-19
3-13 Stream Codes for Figure 3-1 3-23
3-14 Acrylic and Modacrylic Fiber Production Routes 3-26
-iii-
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LIST OF TABLES (Continued)
Page
4-1 Summary of Estimated AN Emission Factors From Monomer
Production 4-2
4-2 Uncontrolled and Controlled Emissions and Emission Factors
for AN and VOC From a Model Sohio Process Plant 4-5
4-3 Summary of Estimated Total AN Emissions From Monomer
Production 4-6
4-4 Estimated Uncontrolled Emissions From Model Plants Producing
45,500 Mg/yr of Acrylic Fiber 4-7
4-5 Summary of Estimated Total AN Emissions From Acrylic Fiber
Production 4-10
4-6 AN Emissions From ABS/SAN Resin Operations 4-11
*
4-7 AN Emissions From Nitrile Elastomer Operations 4-13
5-1 Model Storage Tanks and Emissions Reductions 5-5
5-2 Potential Emissions Reduction For Small Fixed Roof AN
Storage Tank 5-6
5-3 Potential Emissions Reduction For External Floating Roof
Tank 5-7
5-4 Control Devices Currently Used by the AN Industry 5-10
5-5 Controls and Estimated Costs for AN Emission Reduction at
New Monomer Plants 5-12
5-6 Existing Controls in the Acrylic Fibers Industry 5-14
5-7 Estimated Emissions From Model Plants Producing 45,500 Mg/yr
of Acrylic Fiber Using Various Control Options 5-16
5-8 Control Options and Estimated Costs for Acrylic Fiber By
Solution and Suspension Polymerization 5-17
5-9 AN Emissions From ABS/SAN Resin Derations 5-21
5-10 AN Emissions From NBR Operations . 5-23
7-1 Attainment Status 7-5
-IV-
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LIST OF FIGURES
Page
3-1 Flow Diagram for a Sohio AN Plant 3-22
3-2 Acrylic Fiber Processes 3-28
3-3 Emulsion ABS/SAN Process 3-32
3-4 Suspension ABS Process 3-34
3-5 Bulk ABS Process 3-36
3-6 Nitrile Elastomer Process . 3-38
-v-
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1. SUMMARY
The acrylonitrile (AN) industry (segments listed under Standard Industrial
Classification (SIC) codes 2821, 2822, 2824, and 2869) was examined during
this survey. The study was directed at gathering background information
necessary to assess the need for developing a national emission standard
for hazardous air pollutants (NESHAP) for AN under Section 112 of the Clean
Air Act. The AN industry includes AN monomer synthesis operations, acrylo-
nitrile-butadiene-styrene (ABS) and styrene-acrylonitrile (SAN) plants,
acrylic fiber manufacturing facilities, and nitrile elastomer (NBR) plants.
1.1 MONOMER PRODUCTION
There are presently four companies producing AN monomer at six domestic
locations. Texas has the largest number of plants (3 on-line; 1 being
built). Other States with monomer plants are Louisiana, Ohio, and Tennessee.
Total domestic production in 1979 was 915,000 Mg (94 percent of present
972,700 Mg/yr industry capacity) with sales valued at $218 million. The
monomer is used as a feedstock in the synthesis of ABS/SAN resins, NBR,
acrylic fibers, adiponitrile (a nylon intermediate) and acrylamide (a
specialty chemical for use in the paper industry and wastewater treatment).
The monomer industry has been growing at an average annual rate of about
6 percent from 1969 through 1979. Projected growth in the years between
1980 and 1985 is expected to be slightly lower at 3.8 to 4.4 percent.
All domestic AN monomer is produced by the Sohio process. This is a
catalytic vapor phase reaction for the ammoxidation of propylene to AN. It
was developed and patented by the Standard Oil Company of Ohio (Sohio).
This process emits AN to the atmosphere from reactor startups, absorber and
column vents, and fugitive sources (AN transfer and handling, storage
tanks, and process equipment). Total AN emissions to the atmosphere in
1980 from monomer operations were estimated by the Chemical Manufacturers
1-1
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Association (CMA) at 747 Mg/yr. This estimate is based on the installation
of a new incinerator at one plant (American Cyanamid in Westwego, LA) and
recent plant operating improvements made by other manufacturers. The CMA
estimates were compiled by its AN study team formed to evaluate a report on
the AN industry by the Stanford Research Institute (SRI). This 1979 SRI
report estimated AN monomer emissions at 2297 Mg/yr. Updated AN emission
data gathered during this survey are listed in Table 1-1.
The largest AN emission sources from the monomer synthesis process are
the reactor, the absorber, and column vents. Reactor startup emissions are
very large (4545 kg/hr) for several short periods each year (1 hour, 3 to 4
times per year). Several plants send reactor gases through the absorber
and quench columns, then to an incinerator or directly to the incinerator
(to avoid explosion hazards in the absorber lines). This control procedure
can reduce reactor startup emissions by as much as 99 percent. Absorber
and column vent AN emissions can be controlled through thermal incineration
of AN vapors (catalytic incineration is a second choice) for 98 percent
emission reduction.
Fugitive AN emissions sources at monomer plants include AN handling
and transfer (truck, railcar, or barge loading) and process equipment
(pumps, valves, seals, etc.). These sources can have significant emis-
sions. Process equipment fugitive emissions have been shown to be reduced
as much as 87 percent by adopting a regular inspection and maintenance
schedule and using equipment recommended by EPA studies (Synthetic Organic
Chemical Manufacturing Industry NSPS). Many plants are very conscientious
in complying with the Occupational Safety and Health Administration (OSHA)
regulations limiting worker exposure to AN. These regulations have encouraged
good work practices and workplace ventilation but they do not specifically
address control of AN emissions.
Storage tank emissions can be reduced as much as 98 percent through
the use of more effective roof seals (retrofitted according to existing
roof and seal type) or a vapor recovery system. The seals could save a
great deal of previously lost product, justifying their installation and
1-2
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TABLE 1-1 AN EMISSION ESTIMATES FROM MONOMER PLANTS
Plant
American
Cyanamld
DuPont
DuPont
Monsanto
Monsanto
Sohio
Plant*
Location Process Storage Fugitive
Westwego, LA 75.4 19.3
Jefferson
Beaumont, TX
Hard in
Memphis, TN
Shelby
Alvln, TX 6.0 126.0 8.0
Brazorla
Texas City, TX 28.6 57.3 8.0
Galveston
Lima, OH 72.1 57.1 2.7
Allen
TOTAL ( )
Emissions (Mg/yr)
EEVEPA
Process Storage
71.8 109
23.4 4.1
90.2 328.9
27.6 33.3
46.8 56.4
108.9
1125.2)
Fugitive SRI Total
3.6 578
56.2 294
367
34.5 370
58.5 353
35
(2297)
CMA Total
197
43
187
140
94
176
(747)
*Data incomplete, more Information forthcoming as plants review EEA/EPA estimates.
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offsetting their cost. Emissions from transfer and handling of AN during
loading operations can be large. They may be reduced greater than 98 percent
by a vapor recovery system or an incinerator.
1.2 ACRYLIC FIBER PRODUCTION
Acrylic and modacrylic fibers are produced by five companies at six
locations in the United States. There are fiber operations in Alabama,
Florida, South Carolina, Virginia (2), and Tennessee. The total U.S. fiber
production in 1979 was 345,000 Mg. This increased to 353,000 Mg in 1980
(90 percent of the present 390,000 Mg/yr capacity). Fiber sales in 1979
had an estimated value of $450 million.
Acrylic fibers are valued for their similarities in warmth and softness
to natural wool and their ability to be processed into lightweight, high-bulk
yarn. They are used in apparel manufacture and in home furnishings. The
industry has averaged a 3.6 percent annual growth rate from 1969 through 1979.
Projected growth through 1985 is expected to be much slower (estimated at
only 1 percent for the period 1980 to 1985) with most of that growth created
by an expanding apparel market.
Fibers are manufactured by the polymerization of AN with other monomers.
The polymers may be formed by suspension (reaction in aqueous medium) or
solution (reaction in solvent) reactions. Polymers synthesized by suspen-
sion reaction must be coagulated, then dissolved in solvent for the spinning
process. Solvent reaction products are already in solution and go directly
to spinning. The dissolved polymer is extruded into a hot air stream or
into water to remove the solvent and form fiber strands. Fiber is then
stretched, dried, crimped, and cut. Bales of cut fiber are shipped to end
users for dyeing and yarn production.
The AN emission sources from the acrylic fiber manufacturing processes
include the polymer reactor flash tank, slurry steam stripper, crimper
exhaust, and dryers. There are fugitive emissions from AN storage tanks
and process equipment handling streams containing AN. Total domestic AN
emissions in 1980 from fiber plants were estimated at 1361 Mg/yr by the CMA
(SRI 1979 estimate was 4698 Mg/yr), updated emissions data are given in Table
1-2. The AN emissions from the reactor flash tank and slurry steam stripper
can be reduced by 98 percent using an AN recovery scrubber system (scrubber
with secondary control). The AN recovery scrubber vent may be connected in
1-4
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TABLE 1-2. AN EMISSION ESTIMATES FROM FIBER PLANTS
Plant
American
Cyanamid
Badische
DuPont
DuPont
Kodak
Monsanto
Plant*
Location Process Storage Fugitive
Milton, FL 115.1**" 3-3 n. j
Santa Rosa
Willlamsburg, VA 339.6 17.2
Surry
Camden, SC
Kershaw
Waynes bo ro, VA
Augusta
Kingsport, TN 25
Sullivan (Total)
Decatur, AL
TOTAL ( )
Emissions
Process
I/ 5". '7-
333.6
449
283.1
24
0.2
(1416.5)
(Mg/yr)
EEA/EPA
Storage Fugitive
9.3 Jfrtl
19.1
0.4 8.4
19.5 6.6
1
57.7
SRI Total
91 ^
726
480
338
69
2994
(4698)
CMA Total
i ( 91
395
353
339
69
114
(1361)
*Da
ta incomplete, more information forthcoming as plants review EEA/EPA estimates.
.
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series with a chilled condenser or vent gases could be incinerated. A
thorough slurry steam stripping procedure and polymer washing step removes
residual AN monomer such that dryer and crimper exhausts do not contain
significant amounts of AN. Plants using this system account for the lowered
emission estimates by the CMA. Controlling storage and fugitive emissions
at fiber facilities may be accomplished in the same manner as at monomer
synthesis plants. This involves improved seals on all storage tank roofs,
vapor control for AN handling and transfer procedures, and inspection and
maintenance of process equipment in AN service and using recommended equipment
to prevent leaks. Federal regulations concerning worker exposure to AN
apply at fiber plants, but they do not specifically limit AN emissions to
the atmosphere.
1.3 ABS/SAN RESIN PRODUCTION
The U.S. has five companies at 11 different locations producing ABS
resins. There are ABS plants in Massachusetts, Ohio, Kentucky, Illinois,
West Virginia, Connecticut, Michigan, Missouri, California, Iowa, and
Louisiana. The total ABS production from these plants in 1979 was 540,000 Mg
(64 percent of the total U.S. capacity of 843,000 Mg/yr) with industry
sales valued at $548 million. The ABS industry has had an average annual
growth rate of 7.1 percent from 1971 to 1979. Industry growth from 1980 to
1985 is anticipated at about 5 percent per year. Major uses for ABS are in
forming plastic pipes and pipe fittings, appliances, business machines, and
automotive parts.
Monsanto Company and Dow Chemical are the U.S. manufacturers of SAN
resins. They produced 56,000 Mg of SAN in 1979. The SAN resin industry
has experienced an average annual growth rate of 6 percent from 1971 to
1979. These resins are predominately used in compounding with ABS to give
the manufacturer the desired flexibility and strength in the end product.
Some SAN resin is used in injection molding of housewares, small appliance
parts, automotive instrument lenses, and packaging containers.
The total AN emissions to the atmosphere in 1980 from ABS/SAN operations
was estimated by the CMA at 2901 Mg/yr (SRI 1979 estimate was 3084 Mg/yr),
emissions data collected during this survey are listed in Table 1-3.
Emission points and emission rates of AN differ according to the polymerization
procedures used in the manufacture of ABS/SAN resins.
1-6
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TABLE 1-3. AN EMISSION ESTIMATES FROM ABS/SAN PLANTS
Plant
Ah tec
Borg-
Warner
Rorg-
Warner
Dow
Dow
Dow
Dow
Monsanto
Monsanto
Monsanto
U.S.S.
Chemical
Plant*
Location Process Storage Fugitive
Lousiville, KY (Included
Jefferson 4.1 in 0.91
Process)
Washington, W.VA
Wood
Ottawa, FL
LaSalle
Torrance, CA
Los Angeles
Midland, MI
Midland
Pevley, MO
Jefferson
Allyns Point, CT
New London
Addyston, OH 20.0 59.0 5.0
Hamilton
Muscative, IA 332.0 31.0 2.0
Muscative
Springfield, MA 4.0 5.0 1.0
Hampden
Scotts Bluff, LA
East Baton Rouge
TOTAL ( )
Emissions
Process
15.0
647
90.7
4.9
8.9
3.1
4.3
19.9
332
4
156.6
(Mg/yr
EEA/EPA
Storage Fugitive
125
0. 5 1-0
5.9
4.2
8.4
2.6
3.6
64.7 5
31 2
5 1
1.3
1125.2)
SRI Total
125
1769
387
9
15
6
8
163
363
27
154
(2297)
CMA Total
15
1769
387
9
15
6
8
84
365
10
175
(747)
incomplete, nnre information forthcoming as plants review EEA/EPA estimates.
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Resin synthesis may be achieved by emulsion, suspension, mass-
suspension or continuous mass (bulk) procedures. Emulsion polymerization
of ABS/SAN accounts for the large majority of domestically produced resin.
These processes can release AN to the atmosphere from reactor vents, monomer
steam stripper (required for SAN production in conjunction with AN recovery
scrubber), coagulation tank vents, vacuum filtration operations, and polymer
dryer exhausts. There are fugitive AN emissions from storage tanks, transfer
and handling operations, and process equipment. The AN process emission
sources have been reduced by about 95 percent at one plant using high
monomer conversion technology (hMCT) in the reactor in conjunction with an
AN recovery scrubber at the vacuum filtration step (80 percent of the
reduction is attributable to FMCT). This procedure removes residual AN in
the polymer, reducing all AN emissions in downstream processing steps.
Ducting vent gases from AN emission sources to an incinerator/boiler has
also been used for emission control. This control method achieves 98 percent
reduction of AN emissions vented to the system. The applicability of WCT
for the production of the variety of ABS/SAN resins being manufactured is
not known at this time. A plant will have to conduct pilot studies to
determine if the technology is applicable to its process. There are no
data at present to indicate that this technology cannot be used for many
types of resins being produced by the industry. Thermal incineration is a
commonly employed AN emission control method. It reduces emissions and can
supply some plant energy needs. A combination of HMCT with thermal incinera-
tion of vent gases would give the greatest AN emission reduction (estimated
at 99.9 percent), but may not be applicable at all emulsion processes.
Either control method could be used separately, as appropriate to the
facility, for process emission control. Storage and fugitive emission
controls, like those in the other AN industry segments, could reduce these
emissions from this process.
The suspension, mass-suspension, and bulk processes for ABS/SAN production
can emit AN to the atmosphere from reactor vents, SAN slurry steam strippers,
thin film evaporators, and fugitive sources. The SAN steam stripper usually
employs a chilled styrene scrubber to recover unreacted monomers. Emissions
are reduced while improving process operations. This equipment may achieve
1-8
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about 72 percent AN emission reduction. Scrubber vent gases sent to an
incinerator/boiler can be controlled at 98 percent efficiency. These
controls could yield a total 98 percent or greater reduction of AN emissions
from the SAN process. The other processes may have emission points vented
to an incinerator for 98 percent control efficiency. Fugitive and storage
emissions would be controlled as previously discussed.
1.4 NBR PRODUCTION
NBR latexes and elastomers are manufactured by five companies at seven
locations in the U.S. There are plants in Ohio (3), Texas, Delaware,
Louisiana, and Kentucky. Domestic production in 1979 totaled 75,360 Mg
(82 percent of the present 92,000 Mg/yr capacity) with a merchant sale
value of $91 million. Latexes are used in adhesives, paper coatings, and
fabric saturants. Synthetic rubber materials are highly resistant to oil
and function over a wide temperature range. They are valued in the automotive
industry for hoses, gaskets, and seals. Combined with other polymers such
as polyvinyl chloride (PVC) elastomers may be used in a variety of products
(footwear, luggage, or recreational items).
The industry has had an average annual growth rate of 1 percent per
year from 1969 through 1979. Capacity utilization has fluctuated between
72 and 96 percent during this period. Production for NBR is expected to
increase 2 to 3 percent per year through 1985.
Nitrile rubbers and latexes are produced by emulsion polymerization of
AN with butadiene (BD). The basic procedures are similar to the emulsion
polymerization processes used for ABS/SAN resins. The NBR reactions are
carefully controlled to produce the desired polymer chain, then quickly
stopped. Monomer conversion to polymer can vary between 75 and 90 percent.
Residual monomers are steam stripped from the latex slurry, condensed, and
recycled to the process. The NBR process can emit AN to the atmosphere
from the reactor pre-mix tanks, reactor vents, the monomer condenser,
coagulation tank, vents, and polymer dryers. There are fugitive emissions
from AN storage tanks and process equipment in AN service. Emission data
are given in Table 1-4.
Control of AN emissions from NBR processes revolves around the latex
stripper and AN recovery scrubbers. A well designed steam stripper system
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TABLE 1-4. AN B1ISSION ESTIMATES FROM NBR PLANTS
CD
Plant
Goodrich
Goodrich
Goodyear
Goodyear
Relchold
Uni royal
Co polymer
Plant*
Location Process Storage
Akron, OH 108.5
Summl t
Louisville, KY 63.4
Jefferson (Total)
Akron, OH
Summit
Houston, TX
Harris
Cheswold, DE
Kent
Palnesvllle, OH
Lake
Baton Rouge, LA
East Baton Rouge
TOTAL ( )
Emissions
Fugitive Process
14.8 112
332.6
249.3
704.6
5.4
32.8
3.4
(Mg/yr)
EEA/EPA
Storage Fugitive
14.8
0.7
0.2 2.8
6.1
0.9
(1465.6)
SRI Total
123
303
91
79
53
1
(650)
CMA Total
123
254
91
79
6
40
1
(594)
*Data incomplete, more Information forthcoming as plants review EEA/EPA estimates.
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can remove 99 percent of residual monomer from the slurry. This greatly
reduces potential AN emissions from coagulation tanks and polymer dryers.
A chilled water AN scrubber in series with an ammonia chiller can recover
unreacted monomer stripped from the slurry for recycle to the pre-mix
tanks. The estimated efficiency of the scrubber system is in excess of
96 percent. Connecting pre-mix tank vents and reactor vents to the scrubber
system would further reduce AN emissions. Incinerating scrubber and
coagulation tank vent gases in the steam boiler and partially recycling
dryer exhaust could further reduce AN emissions from this process. Fugitive
emissions could be significantly reduced by regularly scheduled inspection
and maintenance of process equipment and by using recommended types of
equipment.
1.5 EXISTING STATE AND FEDERAL REGULATIONS
There are no State regulations that are specifically directed at
limiting AN emissions to the atmosphere. The AN industry has plants in 18
different States. Regulations limiting volatile organic compound (VOC)
emissions from process operations and storage tanks have been enacted in
eight of these States. One State has VOC emission regulations covering
storage tanks only. The remaining States do not have any VOC emission
control regulations.
Worker exposure to AN is limited by OSHA regulations to 2 ppm over a
time-weighted 8-hour averaging period or 10 ppm averaged over any 15-minute
period of the work day. These regulations protect worker safety, but do
not specifically control or limit AN emissions to the atmosphere. The area
monitoring systems often employed to assure workplace compliance with these
regulations may not detect all fugitive emissions - some AN fugitive emissions
can occur in places where workers are not exposed. The plant may comply
with the regulations by simply venting vapors to the air.
The EPA is currently developing VOC emission standards for air-
oxidation processes in the synthetic organic chemical manufacturing industry
(SOCMI). This program is engaged in formulating new source performance
standards (NSPS) and a control techniques guideline (CTG) document for
air-oxidation processes. The EPA is also developing an NSPS and a CTG
document for controlling fugitive VOC emissions from SOCMI and polymer and
resin manufacturing operations. In addition the EPA is involved in writing
an NSPS and a CTG document for VOL storage.
V.
1-11
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The NSPS regulation would apply to monomer plants being built or expanded
after the effective date of the standard (plants already have permits and
regulations are in draft stages now), but are not applicable to the existing
AN emission sources.
There are currently 30 plants using or manufacturing AN in the U.S.
Many plants (22) are located in industrialized areas that are nonattainment
for ozone. The remaining 8 plants are in attainment areas. The draft CTG
documents for controlling fugitive organic emissions from SOCMI operations
would apply to plants in nonattainment areas where the State has requested
an extension to reach attainment. Acrylic fiber, ABS/SAN, and NBR plants
are not covered in this CTG. The draft CTG document outlining control
methods for volatile organic liquid storage (VOL) in fixed and floating
roof tanks would apply to all AN storage facilities in nonattainment area.
(See Chapter 7)
1.6 PREFERRED METHOD OF SAMPLING AND ANALYSIS OF AN EMISSIONS
The EPA has not developed specific reference method (RM) sampling and
analysis procedures for AN point source emissions. There are VOC sampling
and analysis methods (Federal Register, October 3, 1980, RM 25) that should
provide valid data with some modifications. Data collected to date has
been gathered by a variety of sampling techniques (carbon absorption/
desorption and flask grab samples) and analyzed by a gas chroma tograph.
The use of RM 25 sampling techniques with a properly prepared gas chromato-
graph (for qualitative analysis of AN) should yield reliable, valid quanti-
tative AN emissions data.
1-12
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2. INTRODUCTION
A study of the AN industry was performed in this survey. The AN
industry includes AN monomer synthesis, acrylic and modacrylic fiber opera-
tions, ABS/SAN resin manufacture, and NBR production. These industries are
classified by the U.S. Department of Commerce under SIC codes 2821, 2822,
2824, and 2869. Monomer operations produced 915,000 Mg of AN in 1979
(195,000 Mg of this AN was exported), supplying the principal feedstock for
the remaining industry segments. Acrylic fibers manufacture in 1979 consumed
approximately 48 percent (345,000 Mg) of domestically available AN monomer.
These fibers are used in apparel and home furnishings. The ABS/SAN plastic
resins industry was the second largest consumer of AN monomer, using 157,000 Mg
in 1979. The ABS/SAN thermoplastics are formed into automotive parts,
appliances, plastic pipe and pipe fittings, and small consumer products
(luggage, electronics, reacreational items, and furniture). The NBR processes
consumed 88,000 Mg of AN in 1979 for the production of automotive parts
(hoses, seals, gaskets), footwear, luggage, and recreational items. The
study has not closely examined manufacture of adiponitrile or acrylamide
since these processes have very low AN emission estimates.
The goal of the survey was to determine the need for a NESHAP for the
AN industry under Section 112 of the Clean Air Act. The requirements under
Section 112 of the Clean Air Act direct the EPA to develop regulations
establishing emission standards for any air pollutant added to the list of
hazardous air pollutants by the Administrator. The proposed NESHAP Policy
and Procedures for Identifying, Assessing, and Regulating Airborne Substances
Posing a Risk of Cancer (40 CFR Part 61) states that the standard developed
for hazardous air pollutants must, in the judgment of the Administrator,
"provide an ample margin of safety to protect the public health from such
2-1
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hazardous air pollutants." This study has collected background information
toward the goal of developing NESHAP regulations for the AN industry if AN
is listed by the Administrator as a hazardous air pollutant.
The specific objectives of this survey were to confirm and update AN
emissions data, evaluate process AN emission control technology for each
industry segment, and determine possible AN emission reductions using
control techniques observed during the study. This information will be
supplied to the EPA for determining the feasibility of standard development.
The data base formed can then be used to assess emission control methods
and alternatives in conjunction with their environmental and economic
impacts for each industry segment.
The study objectives were met through an extensive search of the
pertinent literature (previous EPA studies, EPA library files, and the
Library of Congress) in conjunction with telephone contacts with trade
associations, plants in each industry segment, government and State agencies,
and industry experts. A series of plant visits to plants with a variety of
process types was conducted to get firsthand knowledge of process operations
and emission control programs. Information requests under Section 114 of
the Clean Air Act were sent to selected plants to enlarge the data base.
Plants contacted in this study are listed in Tables 2-1 and 2-2.
2-2
-------
TABLE 2-1. LIST OF RECIPIENTS OF SECTION 114 LETTERS
Plant and Location
Product
American Cyanamid
West we go, Louisiana
DuPont
Beaumont, Texas
Mo ns an to Company
Alvin, Texas
B.F. Goodrich/Abtec
Louisville, Kentucky
Monsanto Company
Indian Orchard, Massachussetts
American Cyanamid
Milton, Florida
Tennessee Eastman Co.
Kings port, Tennessee
B. F. Goodrich
Akron, Ohio
AN Monomer
An Monomer
AN Monomer
ABS/SAN
ABS/SAN
Acrylic Fibers
Acrylic Fibers
Nitrile Elastomers
2-3
-------
TABLE 2-2. LIST OF PLANTS VISITED
Plant and Location
Product
Borg-Warner Chemicals
Washington, West Virginia
Monsanto Plastics and Resin Co,
Addyston, Ohio
Uniroyal Chemical
Painesville, Ohio
Monsanto Textiles Co.
Decatur, Alabama
Badische Co.
Williams burg, Virginia
ABS/SAN
ABS/SAN
Nitrile elastomer
Acrylic Fibers
Acrylic Fibers
2-4
-------
3. DESCRIPTION OF INDUSTRY
Acrylonitrile monomer is used as a feedstock chemical by the acrylic
fiber, plastics, synthetic rubber, and chemical industries. The various
end uses of AN monomer are presented in Table 3-1. The acrylic fiber
industry is currently the largest single consumer of AN. It has large
markets in the apparel and home furnishing industries. In the plastics
industry, AN is polymerized with styrene and butadiene for the production
of ABS/SAN resins. These are used in the automotive, construction, and
electronic industries. The production of nitrile rubbers is another major
use of AN monomer. These synthetic rubbers are temperature and solvent
resistant. They are used principally by the automotive industry for under-
the-hood seals and hoses. Other markets for AN monomer are in the production
of adiponitrile (intermediate feedstock in Nylon 6/6 manufacture), acrylamide
(used in wastewater treatment and packaging materials), and nitrile barrier
resins (formed into lightweight food and specialty containers). There is
also a considerable export market for raw AN.
3.1 SOURCE CATEGORY
3.1.1 Monomer Production
There are four companies currently producing AN monomer at six domestic
locations. The location and capacity of each monomer facility is listed in
Table 3-2. The current domestic production capacity is 972,700 Mg/yr.
Monsanto Company is the largest producer with 390,000 Mg/yr of capacity at
its Alvin and Texas City, Texas, plants. Other producers are DuPont,
Vistron Corporation, and American Cyananid.
Capacity in the industry is projected to increase 276,000 Mg/yr to a
total of 1,248,700 Mg/yr by 1982 as a result of new plant construction and
expansion. The Monsanto Company will increase capacity by 95,000 Mg/yr
3-1
-------
TABLE 3-1. 1979 AN PRODUCTION AND CONSUMPTION FOR END USE CATEGORIES
Major markets
Fibers
ABS Resins
SAN Resins
Nitrile elastomers
Expo rts
Adiponitrile (from AN)
Ac ryl amide
Barrier resins
Mi seel laneous
Unaccounted
Actual AN production
1979 Production
(Mg)
345,000
540,000
56,000
75,400
—
N/A
N/A
N/A
N/A
Total AN
consumed
(Mg)
345,000a
140,400b
16,800C
26,100d
195,000
86,600e.
28,500f
ll,400f
36,500f'9
29,000h
915,000
% Total
AN consumption
37.7
15.3
1.8
2.9
21.3
9.5
3.1
1.2
4.0
3.2
100.0
aBased on 1 Ib AN to 1 Ib fiber.
bBased on 0.26 Ib AN to 1 Ib ABS.
cBased on 0.30 Ib AN to 1 Ib SAN.
dBased on 0.35 Ib AN to 1 Ib dry elastomer and 0.32 Ib AN to 1 Ib latex.
eBased on Monsanto facility in Decatur, Alabama, at full capacity.
Based on 1977 growth rates given by SRI.
^Fumigants for tobacco, super absorbants, fatty amine production, cyanoethylation
of alcohols and amines. SRI estimates 33,000 Mg produced in 1977.
This category contains any inventory accumulated.
SOURCES: Textile Organon, February 1980; 1980 Facts and Figures of the Plastics
Industry; U.S. International Trade Commission, Synthetic Organic
Chemicals, 1979; SRI Chemical Economics Handbook
3-2
-------
TABLE 3-2. CURRENT AN CAPACITY
Operating capacity
Company Plant location (Mg/yr)
American Cyanamid Westwego, LA 120,200
Industrial Chemicals
Division
E.I. duPont de Nemours Beaumont, TX 158,700
& Company, Inc. Memphix, TN 122,400
Petrochemicals Division
Monsanto Company Alvin, TX 199,500
Monsanto Chemical Texas City, TX 190,500
Intermediates Co.
Standard Oil of Ohio Lima, OH 181,400
Vistron Corporation
Subsidiary
Total 972,700
SOURCE: SRI Directory of Chemical Manufacturers, 1980
3-3
-------
when a third reactor is brought on-line in 1981 at the Texas City plant.
Vistron is currently constructing a 181,000 Mg/yr plant at Green Lake,
Texas, scheduled to come on-line by 1982.
3.1.1.1 Production and Capacity Utilization. Data on AN production
over the past decade are presented in Table 3-3. Total monomer production
in 1979 was 915,000 Mg. The monomer producing companies captively consumed
approximately 55 percent of their production (499,000 Mg). The remaining
416,000 Mg was sold on the merchant market at an average price of about
53 cents per kilogram (current 1981 price is 86 cents/Kg). The total 1979
sales for the monomer industry were $218 million. Exports amounted to
195,000 Mg, or 21 percent of production.
Over the period 1969 to 1979, acrylonitrile production grew at an
average annual rate of 6 percent (525,000 to 915,000 Mg). Growth over this
period led to a series of production capacity increases (from 1971 to 1978)
through plant expansions or new plant construction. Monomer production
during this period was erratic, however, owing to fluctuations in the
acrylic fibers and ABS/SAN resin markets, feedstock shortages, and the
1974-75 economic recession. Capacity utilization had averaged 85 percent
through the decade, with 94 percent capacity utilization'in 1979.
3.1.2 Acrylic Fibers
The acrylic fiber manufacturing industry is the largest consumer of AN
monomer. It uses approximately 48 percent of domestically available AN.
2
The industry consumed approximately 345,000 Mg of AN in 1979.
Acrylic fibers are valued for their resemblance in warmth and softness
to natural wool and their ability to be processed into high-bulk, lightweight
yarns. They are used in apparel manufacture (hosiery, sweaters, pile
fabrics, and craft yarns) and home furnishings (carpets, rugs, furniture
coverings, and blankets). There is also a significant export market for
acrylic fibers.
Acrylic and modacrylic fibers are produced by five companies at six
locations in the United States. The largest producers are Monsanto Company
and DuPont. Other producers are American Cyanamid, Badische Corporation,
and Eastman Kodak. These plants have a total fiber production capacity of
392,000 Mg/yr. Individual plant capacities are listed in Table 3-4.
3-4
-------
TABLE 3-3. AN PRODUCTION, CAPACITY, AND CAPACITY
UTILIZATION 1969-1979
Year
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
Capaci ty
(Mg/yr)
523,800
569,200
612,300
612,300
716,700
716,700
762,000
762,000
762,000
972,700
972,700
Production
(Mg)
523,800
471,300
444,000
505,600
614,200
640,300
550,900
688,500
746,600
794,800
915,000
Capacity utilization
(«
100
83
73
83
86
89
72
90
98
82
94
SOURCES: SRI, Chemical Economics Handbook, U.S. International Trade
Commission, Synthetic Organic Chemicals, 1979, p. 607-5032F
3-5
-------
TABLE 3-4. ACRYLIC FIBER PRODUCERS AND CAPACITIES
Company
Plant location
Annual acrylic
fiber capacity
(Mg/yr)
Annual modacrylic
fiber capacity
(Mg/yr)
American Cyananrid
Fibers Division
Ba disc he Company
E.I. duPont de Nemours
& Company
Textile Fibers Dept.
Eastman Kodak Company
Tennessee Eastman
Division
Monsanto Company
Monsanto Textiles
Company
TOTAL
Pensacola, FL
Williamsburg, VA
Camden, SC
Waynesbo ro, VA
Kings port, TN
Decatur, AL
54,400
31,800
72,600
63,500
136,000
358,300
4,500
18,100
11,300
33,900
SOURCE: SRI Directory of 'Chemical Manufacturers, 1980
3-6
-------
Monsanto, DuPont, and American Cyananid all produce fibers from captive
supplies of acrylonitrile. The Badische and Tennessee Eastman Companies
purchase acrylonitrile on the open market. Vistron is the only AN monomer
manufacturer which is not engaged in acrylic fiber production.
3.1.2.1 Fiber Production and Capacity Utilization. The production of
acrylic and modacrylic fibers totaled 345,000 Hg worth approximately $450 mil-
lion in 1979, an increase of 5 percent from 1978 shipments. Over the
10-year period 1969 to 1979, domestic acrylic fiber production has averaged
a 3.6 percent growth rate per year. Fiber production increased to 353,000 Mg
in 1980. These data are given in Table 3-5. Information on end uses of
acrylic fibers is presented in Table 3-6.
The data in Table 3-6 show that although total production increased
substantially between 1969 and 1979, most of this growth has occurred in
export trade. Exports increased from 41,000 Mg in 1977 to 101,000 Mg in
1979. This increase was primarily a result of lower fiber production costs
in the United States owing to U.S. government price controls on crude oil
(lowering costs of monomer feedstocks) and the weakened dollar (making U.S.
products less expensive overseas). * Trade conditions have changed,
however, and the export market is decreasing. Cbmestic fiber shipments
fell to 248,000 Mg in 1979 after reaching a high of 281,000 Mg in 1977.
This downturn in home markets is due to the declining use of acrylic fibers
in the carpet and rug markets, where lower cost nylon and polyester fibers
have taken control. Producers see apparel applications as the only growth
market for acrylic fibers.
Capacity utilization rates for the acrylic fiber industry were low in
the early 1970's, but increases have occurred owing to gains in export
trade and a reduction of production capacity from 392,000 Mg in 1979 to
376,000 Mg by late 1980. These two factors led to an increase in capacity
utilization from 86 percent to 90 percent. ND firms are planning expansions
or new facilities at this time.
3.1.3 ABS/SAN Resins
The manufacturers of ABS and SAN resins are the second largest consumers
of AN monomer. This industry consumed approximately 157,000 Mg of AN in
1979.
3-7
-------
TABLE 3-5. ACRYLIC FIBERS PRODUCTION AND CAPACITY UTILIZATION
Year
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
Capacity
(Mg)
293,000
299,000
317,000
342,000
357,000
374,000
375,000
394,000
394,000
392,000
380,000
Production
(Mg)
241,800
223,100
247,300
306,600
336,600
286,300
238,000
281,700
321,500
329,200
345,200
Capacity utilization
(*)
83
75
78
90
94
77
63
71
82
84
90
SOURCE: Textile Organon, November 1980 and earlier years
3-8
-------
TABLE 3-6. END USES OF ACRYLIC AND MODACRYLIC FIBERS
(Mg)
End use Year
1975 1976 1977 1978 1979
Hosiery, sweaters,
and craft yarn 87,700 95,300 119,000 109,700 108,300
Pile fabrics 32,100 33,500 39,700 37,400 29,500
Other circular and
flat knit 30,800 38,400 50,700 42,200 44,800
Blankets 15,400 15,600 22,800 25,000 20,600
Other broad woven 6,400 9,800 12,300 13,000 19,000
Carpet face yarns 37,500 39,600 33,000 28,500 21,800
All other 2,100 2,500 3,600 3,500 3,700
Total domestic
consumption 212,000 234,700 281,100 259,300 247,700
Exports 39,100 49,900 41,100 68,400 101,400
Total sales (includes
production and
inventory) 251,100 284,600 322,200 327,700 349,100
SOURCE: Textile Organon, February 1980
3-9
-------
The major applications of ABS resins are in pipe and pipe fittings,
automotive components, and appliances. These products comprised 65 percent
of domestic AN consumption in 1979. Other uses of ABS are in business
machines and telephones, electronic products, recreational equipment,
furniture, and luggage. Major uses of SAN resins are in ABS compounding,
?»•
automotive instrument lenses, and in injection molded parts for housewares
and packaging.
The average AN content of ABS and SAN resins is 25 and 30 percent by
O
weight, respectively. There are numerous types of these resins with dif-
ferent physical properties (chemical and temperature resistance) that vary
with AN content.
There are 5 companies at 11 locations producing ABS resins. They are
listed in Table 3-7. Total domestic ABS capacity is estimated at 814,100 Mg/yr.
The largest producers are Borg-Warner, Monsanto, and Dow Chemical, accounting
for 78 percent of total U.S. capacity. The remaining capacity is divided
among small producers (U.S.S. Chemicals, and B.F. Goodrich Chemical).
Monsanto is the only ABS producer having a captive supply of AN monomer.
Planned capacity changes in the ABS industry will have the net effect of
increasing 'the current capacity of 814,100 Mg to 857,000 Mg/yr by 1982.
Borg-Warner is constructing a 68,000 Mg/yr ABS facility at Port Bienville,
Mississippi, which is slated to come on-line in 1982. Mobil Chemical
recently announced the conversion of its Joliet, Illinois, plant to polystyrene
manufacture.
SAN resins are produced by Dow Chemical and Monsanto. Total present
capacity is about 84,000 Mg/yr. Production of SAN resins in 1979 was
56,000 Mg. Average annual growth rate was about 6 percent per year between
1971 and 1979. No changes in SAN resin capacity are anticipated in the
near future.
3.1.3.1 ABS/SAN Production and Capacity Utilitization. Information
on production of ABS and SAN resins is presented in Table 3-8; ABS consumption
by end use is given in Table 3-9. Production of ABS resins was 540,000 Mg
in 1979 (66 percent of capacity), representing an increase of 5 percent
over 1978 production. During the period 1971 to 1979, production increased
at an average rate of 7.1 percent. Merchant sales (domestic and export) of
3-10
-------
TABLE 3-7. ABS AND SAN PRODUCERS AND CAPACITIES
Company
B.F. .Goodrich Chemical
Company
Borg- Warner Corporation
Bi"i»vi Ua mnat* Than if ale
Location
Louisville, KY
Ottawa, IL
Ua chi'nn+nn UV
ABS capacity
(Mg/yr)
45,400
281,200
SAN capacity
(Mg/yr)
—
U.S.A.
Dow Chemical U.S.A.
Monsanto Company
Monsanto Plastics and
Resins Company
Allyns Point, CT
Ironton, OH3
Midland, MI
Pevley, MO
Torrance, CA
Addyston, OH
Muscatine, IA
Springfield, MA
136,000
238,100
eBOURCE: 1980 Facts and Figures of the Plastics Industry
aThe Ironton plant is only used as needed for ABS production
61,200
22,700
USS Chemicals
Scotts Bluff, LA 113,400
814,100
—
• 83,900
3-11
-------
TABLE 3-8. ABS PRODUCTION
Year
1971
1972
1973
1974
1975
1976
1977
1978
1979
Production (Mg)
ABS
311,100
367,400
397,800
388,700
291,200
448,100
484,900
514,400
540,200
SAN
34,900
44,900
54,400
54,000
49,400
51,200
52,200
54,400
56,200
SOURCES: 1978, 1980 Facts and Figures of the Plas-
tics Industry; Synthetic Organic Chemicals,
U.S. International Trade Commission, 1971,
1972
3-12
-------
TABLE 3-9. TRENDS IN DOMESTIC CONSUMPTION OF ABS RESINS BY END LEES 1973-1979
End use
Appliance
Automotive
Business machines
and telephones
Consumer
electronics
Furniture
Luggage & cases
Modifiers
Recreational
Pipes & fittings
Other Uses
Total
Consumption
(Mg)
48,100
69,900
18,100
9,100
6,800
10,900
6,800
50,800
115,700
69,900
406,000
1973
% of total
11.8
17.2
4.5
2.2
1.7
2.7
1.7
12.5
28.5
17.2
100.0
1979
Consumption %
(Mg)
122,005
77,100
29,500
18,100
11,300
11,300
11,300
40,800
165,600
83,900
571,500
of total
21.4
13.5
5.2
3.2
2.0
2.0
2.0
7.1
29.0
14.6
100.0
1973-79
average
annual
growth
rate (%)
16.8
1.6
8.5
12.1
8.8
0.6
8.8
-3.7 .
6.2
3.1
5.8
SOURCE: 1978, 1980 Facts and Figures of the Plastics Industry
3-13
-------
ABS resins in 1979 totaled about 508,000 Mg (94 percent of domestic production)
and were valued at $548 pillion.9 Exports totaled 35,000 Mg (approximately
6.5 percent of production).
Capacity utilization rates for ABS/SAN producers have been low for
several years, and were under 70 percent for both plastics in 1979. The
low utilization of capacity is attributable to the optimistic expectations
by leading ABS producers in the 1970's. A large excess capacity was built
before downturn in the ABS markets. The ABS market has been losing
ground to competing thermoplastics such as PVC, polypropylene, and high-
impact polystyrene owing to the higher production costs of ABS.
3.1.4 NBR Elastomers
NBR latexes and elastoners are made by the copolymerization of acryloni-
trile and butadiene. These synthetic rubber materials are highly resistant
to oils and function over a wide range of temperatures. The ratio of AN to
butadiene varies depending on the characteristics desired in the final
elastomer product. The AN content typically varies between 30 and 40 percent
of the elastomer by weight.
. Elastomers are used mainly in the automotive industry in hoses, seals,
and gaskets. They may be combined with other polymers such as PVC to
produce a variety of products (footwear, luggage, and recreational items).
Nitrile latexes are used as adhesives, paper coatings, and fabric saturants.
Elastomers and latexes are manufactured domestically by five companies
at seven locations as listed in Table 3-10. Total estimated domestic
capacity is 92,000 Mg/yr. The two largest producers, BF Goodrich Company
and Goodyear Tire and Rubber Company, account for 61,000 Mg/yr of capacity.
Uniroyal, Inc., Reichold Chemicals, and Copolymer Rubber and Chemical
Corporation operate the remaining individual elastomer facilities. The
Copolymer plant was built in 1969 and was the last capacity addition in the
industry. All of these companies purchase AN monomer on the merchant
ma rke t.
3.1.4.1 Production and Capacity Utilization. Production of NBR grew
at an average annual rate of one percent from 1969 to 1979. Total domestic
production in 1979 was 75,360 Mg, requiring approximately 26,000 Mg of AN
monomer. This was a decrease from a peak production of nearly 88,000 Mg in
1974 as shown in Table 3-11. Merchant sales of $91 million accounted for
58,000 Mg, or 77 percent of production, with the remaining output consumed
3-14
-------
TABLE 3-10. NITRILE ELASTOMER PRODUCERS AND CAPACITIES
Capacity
Producer Location (Mg/yr)
Copolymer Rubber and Baton Rouge, LA 5,000
Chemical Corporation
BF Goodrich Company Akron, OH 14,000
Chemical Division Louisville, KY 28,000
Goodyear Tire and Rubber Akron, OH 3,000
Company Houston, TX 16,000
Chemical Division
Reichold Chemical Company Cheswold, DE 10,000
Ihiroyal, Inc. Painesville, OH 16,000
Chemical Division
Total 92,000
SOURCE: SRI Directory of Chemical Manufacturers, 1980; "Emission, Process,
and Control Technology Study of the ABS/SAN, Acrylic Fiber, and NBR
Industries," Pullman Kellogg, April 1979
3-15
-------
TABLE 3-11. NITRILE ELASTOMER PRODUCTION AND CAPACITY UTILIZATION
Year
1969
1970
1971
1972
1973
1974
1975
1976
1977
1978
1979
Production
(Mg)
70,000
68,100
66,500
74,600
84,300
88,000
55,300
72,500
70,100
73,400
75,400
Capacity utilization
76
74
72
81
92
96
60
79
76
80
82
3-16
-------
captively. Exports were 20 percent of production and were valued at $21
million.
Capacity utilization generally varied between 72 and 96 percent from
1969 to 1979, although this figure fell to 60 percent during the 1974-75
recession. Current capacity utilization is 82 percent.
3.1.5 Other Uses of AN
There are several additional domestic markets for AN. The most notable
markets are in the manufacture of adiponitrile, acrylamide, and nitrile
barrier resins.
Adiponitrile (AD) serves as an intermediate feedstock chemical in the
production of Nylon 6/6. This chemical is produced by several different
processes. Monsanto Company, at its Decatur, Alabama plant, operates the
only process that uses AN. It is estimated that this process consumed
72,500 Mg of AN to produce 67,000 Mg of AD in 1977.12 This accounted for
about 10 percent of AN consumption in that year. Total AD production was
426,000 Mg for all processes in 1977.13
Acrylamide manufacture consumed 23,500 Mg of AN to produce 31,000 Mg
of product in 1977. Markets for acrylamide are in wastewater treatment
flocculants (products used to aid in sewage dewatering) and other products
for the water treatment industry. These applications accounted for 35 to
40 percent of all acrylamide used in 1977. Acrylamide is also employed in
the manufacture of paper-treating products. The paper industry accounted
for an estimated 25 percent of acrylamide consumption in 1977. Other
14
markets for acrylamide are drilling mud additives and textile treatment.
There are currently three companies in the U.S. manufacturing acrylamide.
American Cyanamid operates facilities at Linden, New Jersey, and New Orleans,
Louisiana, with a total estimated capacity of 36,000 Mg/yr. Dow Chemical
operates a 23,000 Mg/yr plant at Midland, Michigan, and Nalco Chemical runs
a 4,500 Mg/yr plant at Garysville, Indiana.
The production of nitrile barrier resins is another market for AN.
These resins are valued for high gas barrier and chemical resistance
properties. They are used in food containers and packages and for packaging
abrasive or caustic materials (agricultural chemicals, industrial solvents,
and cleaning products). The consumption of AN in nitrile barrier resin
production was approximately 9,000 Mg in 1977. Nitrile barrier resins
3-17
-------
were first developed in the mid-1970's for use in lightweight, impact
resistant beverage containers to replace glass bottles in the carbonated
beverage market. The Food and Drug Administration (FDA), however, after
conducting studies on the leaching of residual AN monomer from the container
into the beverage, determined AN use in these containers would create a
health hazard. Based on the data from these studies, the FDA banned the
use of nitrile barrier resins for beverage containers in February 1977.
The FDA also set allowable threshold AN levels in other types of food
containers. This action damaged major market potential for nitrile barrier
resins. Vistron Corporation has since been successful in developing container
resins for other food product use which meet FDA restrictions on AN. These
materials are currently used in resealable lunchmeat containers and margarine
tubs. Other applications are in small blow-molded containers for liquid
paper and nail polish bottles.17'18'19
3.2 GROWTH IN AN PRODUCTION
Annual average growth of 4.5 percent in AN monomer production is
estimated through 1985 as listed in Table 3-12. This figure is derived
from AN use in consuming industries and compares favorably with most recent
20
estimates of AN growth. These estimates are more modest than predictions
made several years ago, reflecting the current business slowdown, recent
changes in the U.S. foreign trade position, and competition for AN-derived
products from other less expensive substitutes such as polyvinyl chloride
21 22
(PVC), polystyrene, and nylon. '
3.2.1 Acrylic Fibers
Production of acrylic fibers is projected to increase at a rate of
23 24 25
1 percent per year through 1985. * ' Domestic markets, with the excep-
tion of apparel, are expected to show little growth because of strong com-
petition from lower cost nylon and polyester fibers. Apparel markets are
26
expected to increase approximately two to three percent per year, mainly
through those products where the wool-like properties of acrylic fibers are
desired (sweaters and outer garments). Exports, which reached historic
levels in 1979, fell to 17 percent of fiber production (84,000 Mg in 198027)
owing to the establishment of a permanent anti-dumping duty by the European
28
Economic Community which led most U.S. producers to raise export prices.
3-18
-------
TABLE 3-12. ESTIMATED GROWTH IN AN END MARKETS AND AN DEMAND FROM 1980 to 1985
End Use
Fibers
ABS resins
SAN resins
Nitrile elastomers
Exports
Adiponitrile
Ac ryl amide
Barrier resins
Mi seel laneous
Unaccounted3
Total
Estimated annual rate
1979 AN
Consumption
(Mg)
345,000
140,400
16,800
26,100
195,000
86,600C
28,500
11,400
36,500
26,500
of growth from
Estimated Annual
Growth Rate
In Production and
AN Consumption
1.0
5.0
5.0
2.5
N/A
N/A
9.0d
12. Od
5.0d
19806
1985
Estimated
AN Consumption
(Mg)
366,200
188,200
22,500
30,300
175, OOO5
86,600 •
47,800
22,500
48,900
30,600
1,018,600
4.5%
aEEA estimate from Table 3-1.
bEEA estimate.
cAssumes no extra capacity has been added.
Growth rates from SRI Chemical Economics Handbook.
eAcrylonitrile production in 1980 was reported to have fallen to 816,000 Mg (U.S.
International Trade Commission).
3-19
-------
Over the longer term, increasing feedstock costs for U.S. producers following
oil decontrol and a strengthened U.S. dollar will suppress growth in this
29
area. Production in 1985 is projected at 366,200 Mg.
3.2.2 ABS/SAN Resins
Growth in ABS and SAN resins is projected to be 5 percent per year
30 31 32
through 1985. ' Higher growth rates predicted by industry sources may
be optimistic because of current low capacity utilization, which keeps unit
prices high, and competition from less expensive substitutes such as PVC
and polystyrene which compete with ABS resins in the pipe and automotive
markets. Healthier growth rates will depend on how well ABS can hold off
its competitors in these areas and whether new markets can be developed. A
promising area is the use of ABS in refrigerator liners. One manufacturer
expects this market could stimulate an additional 90,000 Mg/yr of demand
33
within several years. Both ABS and SAN are consumed mainly in durable
goods (housing, automotive, appliance) which are suffering due to current
economic conditions. Projected growth for ABS will probably be slow in the
near term and should improve with business conditions.
3.2.3 NBR Elastomers
NBR production is projected to increase two to three percent
per year through 1985. ' ' The greatest potential growth area is
expected to be as a plastics modifier, mainly in blending with PVC.
Growth will be low because nitrile rubbers are well established in most of
their markets and increases will be determined by general economic condi-
tions. The Rubber Manufacturers Association (RMA) has estimated production
of 88,000 Mg in 1985.38 This would require roughly 33,000 Mg of AN in
1985. Capacity utilization would be 96 percent at this production level.
No expansions are currently planned, however.
3.2.4 Other Areas
No data are available on current production levels for adiponitrile,
acrylanide, nitrile barrier resins, and other miscellaneous uses of acrylo-
nitrile. Production and growth rate estimates made in 1977 have been
employed to estimate 1985 production and AN consumption for the latter
three markets. The consumption of AN for adiponitrile production is esti-
mated at 86,600 Mg, based on Monsanto's Decatur, Alabama, adiponitrile
39
facility operating at full capacity. No expansion of the Monsanto facility
3-20
-------
or other new capacity for adiponitrile production from AN is known, although
40
some sources feel an increase in capacity at Monsanto is possible.
Acrylamide and nitrile barrier resins could each demonstrate strong growth.
Acrylamde use in drilling muds could increase substantially with tertiary
oil recovery.
Monsanto Company filed suit against the FDA ban on AN use in beverage
containers in 1979, and in light of new data, the Court remanded the deci-
sion of the FDA Commissioner for reconsideration. This data concerns AN
levels in a new generation of beverage containers developed by Monsanto.
The FDA is still reconsidering the new evidence and will issue a ruling in
41
the summer of 1981. A favorable ruling for producers could open up AN
use for the beverage container market and stimulate uses in other food
packaging.
AN monomer exports, after reaching a record 195,000 Mg in 1979, fell
to 176,700 Mg in 1980. Exports are expected to average around this level
through 1985. Declining markets in Europe, where the EEC is pressuring
U.S. producers to curtail chemical shipments, and in Mexico and Latin
America, where AN capacity has recently been increased, will be offset by a
rapidly growing Asian market for AN. This market has developed rapidly for
U.S. producers in the past several years as a result of successful competi-
tion against the ailing Japanese chemical industry. Shipments to Japan and
Korea alone increased from 27,000 Mg in 1979 to 64,000 Mg in 1980. Exports
in 1985 are estimated to be 175,000 Mg.
3.3 PROCESS DESCRIPTION
3.3.1 AN Monomer
All domestic AN is produced by ammoxidation of propylene. This process
was developed by Standard Oil of Ohio (Sohio). The Sohio process involves
the vapor-phase catalytic ammoxidation of propylene as represented by the
42
equation:
2CH2 - CH - CH3 + 2NH3 + 302 catalyst 2CH2 = CH - CN + 6H20 (1)
A representative schematic of the Sohio process is shown in Figure 3-1.
43
Process streams are listed in Table 3-13.
3-21
-------
FIGURE 3-1
FLOW DIAGRAM FOR A SOHIO PROCESS AN PLANT
V
r\>
ro
lo
n»p sen
Dcmolfi ••m p*OAf
-------
TABLE 3-13. STREAM CODES FOR FIGURE 3-1
Stream Number Description
1 Propylene feed
2 Ammonia feed
3 Process air
4 Hot reactor product
5 Cooled reactor product
6 Quencher bottoms
7 Quenched reactor product
8 Sulfuric acid
9 Stripping steam
10 Wastewater column volatiles
11 Wastewater column bottoms
12 Absorber vent gas
13 Acrylonitrile plant wastewater
14 Absorber bottoms
15 Water recycle
16 Crude acetonitrile
17 Crude acrylonitrile
18 Recovery column purge vent
19 Acetonitrile column bottoms
20 Acetonitrile
21 Hydrogen cyanide
22 Light ends column purge vent
23 Light ends column bottoms
24 Product acrylonitrile
25 Heavy ends
26 Product column purge vent
27 Flare
28 Fugitive emissions
29 Incinerator stack gas
30 Deep well pond emissions
31 Storage tank emissions
32 Product transport loading facility vent
"3 "JO
-------
Propylene liquid feed (Stream 1) (a mixture of propylene/propane; 90
to 97 weight percent propylene stored at 21°C and a pressure of 1,050 kPa)
is vaporized and preheated by process steam prior to its introduction in
the reactor. Agricultural grade liquid ammonia (99.8 weight percent minimum
and stored at 21C and a pressure of 890 kPa) is also vaporized and preheated
before entering the reactor (Stream 2). Air (Stream 3) is filtered and
compressed for use in the reaction. The propylene/ammonia/air reactants
are then fed into the reactor in the approximate molar ratio of 1:1.06:8.4.
The three percent excess ammonia forces the reaction towards completion and
the 18 percent excess air helps to continuously regenerate the catalyst.
Several catalysts have been used since the process was developed. A bismuth-
molybdenum catalyst (Catalyst 41) introduced in early 1972 substantially
increased the yield from propylene and reduced the production of by-products
such as acetonitrile, hydrogen cyanide, and ammonium sulfate. With the
present technology and good raw materials, the process yields 0.8 Ib AN/lb
44
of propylene feed.
The reactants are fed continuously to a gas fluidized bed catalytic
reactor operating at a pressure of 135 to 310 kPa and a temperature of 400
to 510°C. Reactor temperature is controlled by internal cooling coils
which generate about 75 percent of the plant's process steam requirements
while removing the heat of reaction (approximately 21.9 kJ/g AN). Hot
reactor gases (Stream 4) are sent through a waste heat boiler which produces
about 25 percent of the process steam requirements. The product gases are
thus cooled from 510 to 230°C prior to entering the quencher.
The quencher operates at pressures from 135 to 205 kPa and 40 to 50°C.
Streams entering the quencher are the cooled reactor effluent (Stream 5),
sulfuric acid (Stream 8), and wastewater column volatiles (Stream 10). The
reactor gases are cooled further and catalyst fines are removed by the
scrubbing action of the quencher. Quencher bottoms (Stream 6) are fed to a
wastewater column where the volatile components of the stream are steam
stripped (Stream 9). The wastewater column bottoms (Stream 11) are sent to
the deep well pond. The quenched reactor effluent (Stream 7) is then ready
to be fed into the absorber. A typical plant may have two reactors and
quench neutralizes feeding a single recovery and purification train.
3-24
-------
The AN and by-products (hydrogen cyanide (HCN) and acetonitrile (ACN))
are recovered by water absorption in a tray-type absorber column. Recycle
water (Stream 15) from the acetonitrile column enters the top of the absorber,
scrubbing AN, ACN, and HCN from the quenched reactor gases (Stream 7)
entering at the bottom. The absorber vent gas (Stream 12) is vented to the
atmosphere or sent to a control device. Absorber bottoms (Stream 14) are
sent to a recovery column for separation of crude AN (Stream 17) and crude
HCN (Stream 16). The crude AN stream is sent to crude AN storage and con-
tains about 80 percent AN, 12 percent HCN, and about eight percent impurities
(water and organics).
The crude ACN (Stream 18) is sent to the ACN column. The ACN is
extracted and may be incinerated or purified and sold. The water recycle
(Stream 15) is sent to the absorber and the ACN bottoms (Stream 19) are
sent to the deep well pond.
Crude AN from the crude tank storage (Stream 17) is fed to the light
ends column to remove low-boiling organic components. By-product HCN
(Stream 21) from the light ends column is incinerated or sold. Light ends
column bottoms (Stream 23) are sent to the product column. Product column
bottoms (heavy ends; Stream 25) are incinerated. Vent streams from the
recovery, light ends, and product columns (Streams 18, 22, and 26, respec-
tively) are sent to a flare for emission control.
The product AN stream (Stream 24) is 99+ percent pure. It is sent to
storage to await shipment by tank truck, barge, or railroad car.
3.3.2 Acrylic Fibers
The basic manufacturing process is the same for both acrylic fibers
(containing at least 85 percent by weight of AN) and modacrylic fibers
(containing less than 85 percent, but more than 35 percent AN). This
section refers to the two fiber designations as "acrylics" except where
specifically differentiated. Each manufacturer uses a somewhat different
patented process of monomer polymerization and fiber spinning and finishing
to form acrylic fibers. Table 3-14 outlines the different acrylic fiber
production routes used by each domestic manufacturer.
The physical and chemical properties of each of the different polyacrylonitrilt
fibers will vary depending upon:
3-25
-------
TAm.E .1-11. ACRYLIC Win MODACRYLIC FMER PRODUCTION ROUTES
co
i
ro
en
Acrylic fibers
American Cyanamld Company
Rndlsche Company
E.I. duPont T)e Nrmnurs A Co.
Mnnsanto Company
Modacryllc fibers
F.l. duPont De Honours S Co.
Eastman Chemical Products, Inc.
Monsanto Company
Registered
trade name
Creslan"
Zcfran
Orion
Acrllan
Orion EIR
Verel
El lira
SEF
Typical chemical
compos 1 lion of
fiber
09-901 Acrylonlfrlln
81 Mo thy 1 ftelhacrylato
2-SJ Othrr
07-90* Acrylonltrlle
81 Ho thy 1 Aery late
2-5* Other
00-9IX AcrylonltrHp
11 Methyl Aery la IP
2-5X Other
8n-9lt Acrylonltrlle
8-101 Vinyl Acetate
2-11 Other
66-701 Acrylonltrlle
30X Vinyl Chloride
0-« Other
37t Acrylonltrilc
40% Vlnylldene Chloride
201 Isopropylacrylamlde
.1* Methyl Acrylatc
76-nit AcrylonltrMe
20* Vinyl Acetate
2-1J Other
79-81* Acrylonltrlle
OX Vlnylldene Chloride
9* Vinyl Rrnmlde
7-1* Other
Polymerization
medium
Suspens Ion
Solution
Siispens Ion
Suspension
Suspension
Solution
Suspension
Suspension
Type of
polymer Ijat Ion
operation
Continuous
Continuous
Continuous
Hatch
Continuous
natch
Hatch
Oatch
Type of
spinning
process
Wot
Met
Dry
Mnt
Dry
Pry
Met
Met
Spinning
sol vent
Aqueous
riaSCN
Aqueous
/nCl?
fflE
DMAc
UMF
Acetone
flMAc
DflAc
17
SOURCE: Pullman Kellofjg Report, April 1979, p. RO .
"Creslan" Is not a product of the Santa Rosa fiber plant. It Is a registered trademark of the A-nerlcan Cyanamld Company for use on end
products made with Cyanamld's acrylic fibers and which meet Chanamlds product qiiallty standards.
h R R
In addition to Elura and SEF , Monsanto also has two other mndacryllr fibers, known as type 65 and type 67.
-------
1. the inherent chemical structure of the fiber polymer;
2. the kind and amount of modifier used to tailor fiber properties
for a specific application;
3. the fiber spinning method; and
4. the degree of stretching and other finishing operation
Although there are minor variations in acrylic fibers, they generally have
a combination of properties that make them suitable for many applications
in textiles, y A block diagram of the acrylic fiber production process
showing the alternate polymerization reaction routes is presented in Figure 3-2.
Most acrylic fibers are copolymers of AN and at least one other monomer.
These copolymers may be formed using suspension or solution polymerization
in a batch or continuous reaction mode. The most commonly used comonomers
are acrylate and methacrylate esters and vinyl acetate for acrylic fibers,
and vinyl and vinylidene chloride for modacrylic fibers. These comonomers
generally have a specific function in the polymer. A third comonomer is
often added to improve dyeability. Other agents may be added (during
polymerization or before spinning) in small quantities (totalling less than
5 percent). These can be polymerization catalysts or finishing agents
performing static reducing, lubricating, heat or light stabilizing, delustrant,
(5ul
or optical brightening functions\__J
Acrylic fibers are produced by either suspension or solution polymerization,
Suspension polymerization is the more common process in the united States,
while solution polymerization is more prevalent in Europe. In either type
of process, conditions such as monomer feed ratios and temperatures must be
carefully controlled so the j^aciion will yield a polymer with the desired
chain construction and 1engthk_y
In suspension polymerization, the monomers are dissolved or suspended
in the fora of small globules. These are dispersed by vigorous agitation
throughout a water solution, which contains a monomer soluble catalyst.
The monomers are polymerized at temperatures with /typical monomer conversion
to polymer at about 65 to 85 percent of feedstock^,) The polymer formed is
insoluble and, thus, can be filtered from the aqueous reaction medium.
After filtering, the polymer is washed to remove impurities, refiltered,
3-27
-------
FIGURE 3-2
ACRYLIC FIBER PROCESSES
Solution
Route
Suspension
Route
oo
Polymerization/
Spinning Solvent
i
AN RECOVERY
r
AN Monomer ^
Comonomeis
AN Monomer ^
Comonomeis ""
Polymerization
Reactor
PotyMfiiallon
Reactor
t
Water,
Slabili/ei
Vacuum
Flash Tank
» Stripper" °°<*
Spinning
Solvent
I
Vacinm
Flash Tank
i
Filter
1
Fit
Finh
* . * * * Miilngt
la> ttrlniwl k> Filler ... a, PtHtHltt , •> fJlYM ...•> nittnUin* '1°'*e •>
{ Tank
J
Spinning Do
SOLVENT RECOVERY
1
^ "spinning TOW ^ * Fiber ^ Fiber ^ „„.,„. ^ * Fiber ^ S
1 * Balh * Wash * Stretching * "* ' ~ * Dimplng *
c j
*r
him
•> finding |> Culling Sl"|''e ^ Baling
i •
Oeaeralor
pe 1 •
elling
h»ei
1 -
r i
Tow
Yam
Slurry Strippers are Add on Oevlcei thai maybe inlha Proof f
Baled
Staple
AN Emitlion Point lor
Solution Route
AN Emisdon Point for
Suspension Route
-------
milled into small pellets, and dried. The dried polymer pellets must then
be redissolved in a fiber-spinning solvent. Monomers are recovered from
the filtration and washing steps and recycled to the polymerization reactors.
The pelletizer is the second greatest source of uncontrolled AN emissions
from suspension polymerization, while by far the greatest AN emissions are
released from the polymer dryer.
In solution polymerization, AN and other comonomers are dissolved in
the spinning solvent and reacted to form the polymer in solution. The
polymerization/spinning solvent must be highly polar, but can be an organic
(dimethyl formamide (DMF), dime thy! acetamide (DMAC), or acetone), or an
inorganic solvent, (usually a concentrated aqueous solution of zinc chloride,
sodium thiocyanate, or nitric acid).(j^>An initiator (e.g., azobisisobutyoni-
trile) is usually added to begin the polymerization reaction. Since the
monomers and polymer are soluble in the polymerization solvent which is
also used as the spinning solvent, only negligible quantities, if any, of
AN are emitted during solution polymerization.
The prepared polymers must be made ready for fiber manufacture or
spinning. Dried polymer pellets made by the suspension route must be
redissolved in a spinning solvent. Fblymer made by the solution reaction
is ready for spinning without the filtering, washing, pelletizing, and
drying steps. The concentration of polymer (usually 10 to 35 percent for
polymer of a molecular weight between 80,000 and 170,000) in the spinning
dope is limited by a workable viscosity at an economic temperature for the
particular solvent and extrusion (spinning) equipment. The polymer must be
basically linear as branching can adversely affect spinning. Fblymer
solutions (or spinning dopes) are then filtered and degassed under vacuumi-
The spinning dope is extruded through spinnerets in wet or dry spinning
processes to form fiber tow. The polymer solution (generally 10 to 25 per-
cent polymer) is extruded through spinnerets having typically 1,000 to
3,000 (some having as many as 60,000) holes, each of 50 to over 100 micro-
meters Ozm) in diameter. Fiber is formed at a rate of 2 to 200 meters per
minute. The wet process tow is extruded into a bath of spinning solvent
diluted with water so that the fibers coagulate at the proper rate. Water
is added countercurrently to the tow to wash out the solve.nt. The main
advantage of this wet -sjjipning is that tow can be further processed on a
. . 53, £4755*)
continuous basis. VlZ^
3-29
-------
Dry spinning extrudes rare concentrated (20 to 25 percent polymer)
preheated solutions through spinnerets having typically 200 to 600 (some
having as many as 900) holes, each wi th a diameter of 50 to 150 fin. Fiber
is extruded at a rate of 200 to 400 m/minute. The tow is extruded into a
column of hot circulating air which is 50 to 110°C higher than the boiling
point of the spinning solvent. As the solvent evaporates, the fibers
solidify. The fibers are collected as tow while the vaporized solvent is
recovered and recycled. '
Spinning and washing are the only significant sources of emissions
from solution polymerization processes if the unreacted AN monomer has not
been removed previously. Spinning is a negligible source of emissions from
suspension polymerization processes as the unreacted AN has already been
removed during pelletizing and drying.
After wet or dry spinning, the fiber tow is passed through a heated
bath in order to (1) remove the about 10 percent residual solvent for
recovery required for an economic operation and (2) heat the fiber so it
can be drawn.
Drawing involves stretching the fiber tow 4 to 10 times its original
length, in order to orient the polyacrylonitrile chains along the fiber
axis and thus improve fiber properties. Stretching is normally accomplished
using air, hot water, or steam at 70 to 110°C and rollers rotating at
increasing speeds. After stretching, the fibers are crimped to provide a
texture similar to natural fibers and dried, which also stabilizes or sets
the crystalline structure (dimensions) and other physical properties and to
improve dyeability. Fibers may undergo finishing (i.e., are coated with
lubricating and antistatic agents) to facilitate textile processing operations,
Finally, fibers may be cut into staple (6 to 15 am in length) and baled,
left uncut and sold as tow, or wound on bobbins and sold as continuous
48 54
filament yarn. * Emissions of AN from finishing operations are negligible.
3.3.3 ABS/SAN
Three types of polymerization processes are used for the commercial
production of ABS plastics. The majority of ABS resins are produced pri-
marily by emulsion polymerization although suspension and bulk polymerization
are also used.
3-30
-------
3.3.3.1 Emulsion Process. The emulsion process consists of three
distinct polymerizations. A polybutadiene substrate latex is prepared,
styrene and acrylonitrile are grafted onto the polybutadiene substrate, and
styrene acrylonitrile copolymer is formed. The latter two reactions may
take place simultaneously in the same vessel (used for graft ABS polymers
with low polybutadiene content) or in separate vessels and then latex
blended. A flow sheet for the emulsion process is shown in Figure 3-3.
Butadiene is first charged to a water jacketed batch pressure reactor
(1) containing emulsifiers. Additional emulsifiers, catalysts, and demine-
ralized water are then added. Reaction temperature may be varied from 5 to
70°C depending on the desired structure of the polymer. It is controlled
by circulating cooling water in the jacket. The rate of reaction is limited
by the ability of the cooling jacket to remove the heat of polymerization.
The time required for this synthesis step ranges from 12 to 24 hours.
Reaction conditions and chemical recipes are important to end product
properties. Latex particle size is determined by the emulsifier and quan-
tities of the various monomers used in the reaction. Excess crosslinking
and ring-formation may be prevented by the addition of a shortstop such as
sodium dithiocarbonate after 70 to 90 percent monomer conversion (monomer
conversion in emulsion reactions can be greater than 96 percent). The
unreacted butadiene and monomers are stripped from the latex in a flash
stripper (2). The reactor, stripper, and recovery system vents are directed
to a butadiene flare system. The polybutadiene latex is stored for use in
graft reactions.
The next synthesis step (3) is the grafting of styrene and acrylonitrile
into the polybutadiene substrate which serves as the "backbone" latex. The
amount of substrate used in the graft reaction is determined by the physical
properties desired in the final polymer and usually ranges from 10 to
60 percent by weight of the polymer. The graft reaction may be either
batch or continuous. In a batch reaction, emulsifiers, such as sodium
oleate, initiators (cumene hydroperoxide), and activators (sodium pyrophso-
phate, dextrose, and ferrous sulfate) are prepared separately and charged
to reactors which have been purged of oxygen. A free-radical initiator,
such as potassium persulfate, may be used to start the reaction. A chain-
transfer agent, such as terpinolene, is also needed. Appropriate quantities
3-31
-------
Butadiene,
Emulsifiirs.
Initiators,
Watir
AN to Atmosohere
o
To Incinerator
t
AN Storage
Emissions
AN
Absorber
Acrylonitrilc,
Styrtnt,
Emulsifitrs.
Catalysts, Water
J
Bitch Pressure
Reictor
AN 4—
Storage
Emissions
- Acrylonitrile
Emulsifiers
and initiators
Atmosphere
AN to Atmosphere
ALTERNATIVE
SAN PATH
FIGURE 3-3
EMULSION ABS/SAN PROCESS
Packaging
3-32
-------
of styrene and AN monomers are added and mixed to form an emulsion while
the temperature is raised and maintained at the reaction temperature (usually
between 50 and 75°C). In continuous processes, monomers, water, emulsifiers,
and soap are mete red and pumped in continuously and overflowed continuously
from the reactors. Reaction conversion of monomers is around 95 percent
for the batch polymerization process and slightly lower for continuous
processes. Vapors from the reactors are pumped to an AN absorber (4).
Absorber bottoms are recycled and the tops are sent to an incinerator (5).
The copolymerization of AN and styrene is achieved by feeding the
monomers to a reactor vessel (6) along with deionized water, emulsifiers,
and catalysts. Monomer conversion efficiencies to SAN range from 90 to
98 percent. Polymer solids are recovered from latex by coagulation and
flocculation. The emulsifiers are chemically destroyed by adding dilute
salt or acid solution and the polymer solids are allowed to agglomerate
(7). Calcium chloride, sodium chloride, sulfuric acid, and hydrochloric
acid are commonly used coagulation agents. The agglomerated polymer is
dewatered by screening (8), centrifuging (9), and vaccum filtration (10).
Solids are mechanically blended (11) with dyes, antioxidants, and other
additives. The polymer sheets from these operations are then pelletized
and packaged (12).
ABS plastic is a blend of graft rubber and SAN resin. The graft latex
may be mixed with SAN resin either in the latex stage before coagulation or
mechanically mixed at the finishing stage.
The potential AN emission sources from this process are storage tanks,
graft reactors, absorbers, latex treatment vessels, and polymer dryers.
These emission points are illustrated in Figure 3-3.
3.3.3.2 Suspension Process. Although most ABS is produced by the
emulsion process, suspension polymerization is also used to produce specia-
lized plastics. The suspension process, shown in Figure 3-4, begins with a
polybutadiene rubber which is so lightly crosslinked, it is soluble in the
monomers. The polybutadiene is typically synthesized by the batch emulsion
process previously described.
Polybutadiene is dissolved in styrene and AN monomers (1) to produce a
solution free of crosslinked rubber gels. A free-radical initiator such as
an organic peroxide or an azo compound is added to the solution along with
3-33
-------
FIGURE 3-4
SUSPENSION ABS PROCESS
Storage Tanks
AN Emissions
Polybutadiene.
RubDer
J
Rubber Oissolver
Initiators
ana Agitation
AN
Styrene
AN
J
Pre-Polymerizer
AN
Suspending Agent,
Water
Suspension Reactor
AN
Dewaterinj
AN
Hot Air
Dryer
Product
Storage
3-34
-------
chain-transfer agents (2). It is then heated to 80 to 120°C for a period
of two to eight hours with sufficient shearing agitation to prevent cross-
linking and maintain the desired polymer particle size. After 25 to 35 percent
monomer conversion, the polymer syrup is transferred by a high viscosity
gear pump to a suspension reactor (3) where it is dispersed in water with
agitation. Suspending agents are added to the reactor and it is heated to
100 to 170°C for about six to eight hours.
After achieving the desired monomer conversion, the products are
cooled and pumped to a dewatering system (4), usually a continuous centrifuge.
The polymer beads are washed and dewatered to less than 10 percent moisture.
Wet product beads are then conveyed to a conventional hot air dryer (5)
where they are dried to less than 1 percent moisture. Suspension ABS
polymer beads range in size from 0.4 to 1.2 mm in diameter. The dry beads
are stored in silos prior to compounding.
Possible AN emission sources from the suspension process are the pre-
polymerizer, the suspension reactor, the dewatering system, and the dryer.
Emission points are illustrated in the flow diagram.
3.3.3.3 Continuous Mass (Bulk) Process. The continuous mass (bulk)
process has recently begun to achieve more commercial importance. It was
previously used only by Dow Chemical Company, but several other manufacturers
have entered into preparation of ABS plastics by this procedure. The
reaction does not proceed in water, so treatment of wastewater is minimal
and less energy is used per unit weight of product since no dewatering or
polymer drying is needed. It is a more mechanically complex process with
less product flexibility and lower monomer conversion (requiring devolat-
ilization of the polymer), but these problems are outweighed by the process
advantages. A block flow diagram for the process is given in Figure 3-5.
A monomer-soluble polybutadiene substrate is dissolved in styrene and
AN with initiators and modifiers (1). The mixture is polymerized through
phase inversion to approximately 30 percent monomer conversion (2). This
prepolymerized syrup is then pumped into a specially designed bulk polymerizer
(3) where monomer conversion is taken to between 50 and 80 percent. (No
water is used in this procedure.) The bulk polymerizer is operated continu-
ously at 120 to 180°C with polymer residence times of one to five hours. Monomer
3-35
-------
FIGURE 3-5
BULK ABS PROCESS
AN
Pelybutadiene
Rubber
AN Storage
J
,J
AN
Styrene
Initiators and Modifiers
AN
Pelletizer
3-36
-------
vapors evaporated by the heat of reaction are condensed and recycled with
fresh ronomer feed (4). The polymer melt is pumped to a devolatilizer (5)
where remaining unreacted monomers are removed under vacuum at temperatures
in excess of 150°C. Normally, about five to 30 percent of the feed stream
is removed as unreacted monomer and recycled. The ABS polymer is removed
from the devolatilizer via a melt pump or extruder and chopped into pellets
(6). The AN emission pints include the bulk polymerizer, the monomer
vapor condenser, and the devolatilizer as shown in Figure 3-5.
3.3.3.4 SAN by Emulsion Process. The emulsion copolymerization of
styrene and AN to SAN resin is achieved commercially by both batch and
continuous processes. A typical reaction system is shown in Figure 3-3.
Portions of the monomers (68.5 parts styrene; 31.5 parts AN), an initiator-
emulsifier solution (potassium persulfate, rosin soap, and desalted water),
and a chain-transfer agent (tert-dodecyl mercaptan) are charged to the
reaction and then purged with nitrogen. Polymerization temperature is
controlled at about 80°C by reflux cooling of the reaction mixture. The
remaining portions of reactants are added to the reaction system continuously.
The reaction is allowed to proceed for about one hour after final addition
of reactants (total cycle time is one to three hours) with monomer conversions
reaching 97 percent or higher. The SAN latex slurry may be directly blended
with a SAN grafted-rubber latex for ABS production or coagulated to recover
SAN copolymsr. Coagulation of the latex is accomplished by adding electrolyte
(dilute salt or acid solution) or freezing. Polymer is then washed and
dried.
3.3.4 NBRETaTfome rs
Nitrile elastomers are copolyners of AN and butadiene. They are
produced by emulsion polymerization in batch or continuous processes. The
process block flow diagram is shown in Figure 3-6.
The emulsion polymerization process uses water as a carrier medium.
This offers the advantages of safety, inexpensive product and ncnomer
recovery, and ease of product purification compared with organic solvents.
Nitrile rubbers are generally manufactured as either hot or cold types
depending on temperatures at which the polymerizations are controlled.
These temperatures are about 40°C for hot types and 5°C for cold types.
Cold varieties have lower content of branched and crosslinked polymer
chains and can be better processed.
3-37
-------
1 AN Storage
Chilled Oil
AN
FIGURE 3-6
NITRILE ELASTOMER
PROCESS
Butadiene
to Storage
or Recycle
o
Screenint, Washing.
Dewitering
3-38
-------
Butadiene and AN monomers are piped to agitated polymerization reactors
(1) along with additives and soap. The water not only serves as a reaction
medium, but also effectively transfers the heat of reaction to the cooled
reactor surfaces. The additives include catalysts (cumene hydroperoxide as
an oxidizing component), and sodium formaldehyde sulfoxylate with EDTA
(ferrous sulfate complexed with ethylenediamine-tetraacetic acid) as the
reducing component) and modifiers (alky! mercaptans).
The rosin soap solution forms small bubbles called micelles. These
micelles act as tiny reaction vessels for the polymerization processes.
Inside the micelles free-radicals formed in the water phase by the initiators
(organic peroxide or potassium persulfate) create polymer nuclei from the
monomers trapped in the bubble. Droplets of monomer outside the micelles
supply the reaction sites with raw materials. The small polymer particles
formed in the micelles continue polymerization with the supplied monomers
and grow into the desired polymer chain. The soap bubbles cover the rubber
particles formed and keep the mixture in liquid form (prevent agglomeration
and plugging of the reactor).
The reaction is allowed to proceed for 5 to 12 hours. A shortstop
solution (sodium bisulfate or potassium dimethyl dithiocarbonate) is added
to terminate the reaction at a predetermined point, usually after 75 to
90 percent conversion (depending upon the desired moleclar weight of the
product). The reaction latex is then sent to a blowdown tank (2) where
antioxidants are normally added.
The latex is subjected to several vacuum flash steps (3) where most of
the unreacted butadiene is released. It is then steam stripped under
vacuum (4) to remove the remaining butadiene and most unreacted AN. The
unreacted monomers are sent to recovery and recycle. Stripped latex at
about 110 to 130°F is pumped to blend tanks (5).
Gases released in the flash steps and stripper overhead contain butadiene
These are sent to a partial condenser and separator (6) where butadiene
vapor is condensed and sent to liquid storage. Uncondensed butadiene vapor
from the separator flows to an absorber (9) where it is absorbed by counter-
current contact with chilled oil. The absorber bottoms are pumped to a
flash tank and dissolved butadiene is released and returned to the compressor.
The hot lean oil is then cooled, chilled, and returned to the top of the
ab so rbe r.
3-39
-------
Unreacted AN in flash vapors and latex stripper overhead is recovered
by sending these gases to a water absorber (10). Absorber bottoms and the
liquid phase of the latex stripper overhead are pumped to a steam stripper
(11). The overhead vapor stream from this stripper is condensed in a
decanter. Phase separation is allowed to take place and the AN phase is
decanted to storage while the water-rich phase with residual AN is returned
to the stripper.
Latex is pumped from the blend tanks (5) to a coagulation tank (6)
where the emulsion is broken by the addition of dilute inorganic salt
solution (sodium chloride or aluminum sulfate) or weak organic acid. The
slurry of fine polymer crumb is then filtered to remove coagulating chemicals
(liquor is recycled) and may be reslurried for further purification. Crumb
is dewatered in an extruder (12), then hot air dried (13). Dried rubber is
weighed, pressed into bales, and prepared for shipment.
If latex is the desired product, the final processing steps (coagulation,
screening, washing, and drying) are omitted. The initial steps are essentially
identical with those of solid rubber production.
Emissions of AN may occur from the storage tanks, reactors, and absorbing
and stripping columns, as shown in Figure 3-6.
3-40
-------
REFERENCES TO CHAPTER 3
1. U.S. International Trade Commission. Synthetic Organic Chemicals,
U.S. Productions and Sales. 1979.
2. Stanford Research Institute. 1978 Chemical Economics Handbook. Menlo
Park, California. 1978. p. 607.5032J.
3. 1980 Kline Guide to the Chemical Industry, p. 172.
4. Textile Economics Bureau, Inc. Textile Organon. New York. February 1981.
5. The Coning Squeeze on Petrochemical Exports. Chemical Week.
October 1, 1980. pp. 26-31.
6. A Shaky Recovery for Chemical Producers. Chemical and Engineering News.
December 22, 1980. pp. 30-35.
7. Chemical and Engineering News. December 1, 1980. p. 12.
8. Reference 2. p. 607.5032J.
9. Reference 1.
10. ABS Market: A Mix of Optimism and Problems. Chemical and Engineering News.
July 30, 1979. pp. 8-9.
11. Click, C.N. and Moore, D.O. Emission Process and Control Technology
Study of the ABS/SAN Acrylic Fiber, and NBR Industries. Pullman Kellogg
Final Report for EPA Contract No. 68-02-2619, Task 6. Houston, Texas.
April 1979.
12. Reference 2. p. 607.5032W.
*
13. Reference 12.
14. Reference 2. p. 607.5032X.
15. Reference 2. p. 607.5032Y.
16. Reference 2. p. 607.5032Z.
17. AN Maneuvers for a Comeback. Modern Packaging. April 1979.
18. Acrylonitrile's Still a Worry. Modern Packaging. June 1978.
19. High-Clarity Acrylonitrile Scores for Small Containers. Modern Plastics.
December 1978.
20. Chemical Marketing Reporter. February 4, 1980.
21. Reference 2. p. 607.5031D.
3-41
-------
22. Reference 11.
23. Reference 2. p. 543.3521F.
24. Reference 7.
25. EEA contacts with industry.
26. Reference 23.
27. Reference 4.
28. EEC Moves Against U.S. Acrylic Fibers. Chemical and Engineering News.
May 12, 1980. p. 8.
29. The High Cost of Oil Decontrol is Hitting Home. Chemical Week.
February 11, 1981.
30. EEA estimate.
31. Reference 10.
32. Letter from Harvey, L.A, President, Borg-Warner Chemicals, to Editor,
Chemical and Engineering News. October 22, 1979. pp. 4-5.
33. 1979 Annual Report. Borg-Warner Corporation.
34. Reference 11.
35. Reference 21.
36. Lean Years Ahead for the Rubber Industry? Rubber World. January 1980.
pp. 27-28.
37. C.H. Kline, Inc. Elastomers, A Forecast to 1983. 1979.
38. Reference 36.
39. Stanford Research Institute. 1980 Director of Chemical Producers of the
United States, Supplement. Menlo Park, CA 1980.
40. Reference 12.
41. Monsanto Company v. David Kennedy and Joseph A. Califano, Jr. No. 77-2023.
U.S. Appellate Court D.C. Circuit. November 6, 1979.
42. Hobb, F.D. and Key, J.A. Hydroscience, Inc. Emission Control Options for
the Synthetic Organic Chemical Manufacturing Industry: Acrylonitrile
Product Report. Report from EPA Contract No. 63-02-2577.
August 1978. p. III-l.
3-42
-------
43. Hughes, T. W. and Hour, D.A. Source Assessment: Acrylonitrile
Manufacture (Air Emissions). EPA-600/2-77-107. September 1977.
pp. 10-20.
44. Reference 43. p. 13.
45. Reference 43. p. 17.
46. Reference 43. p. 19.
47. Reference 11. p. 80.
Considine, D.M. Chemical and Process Technology Encyclopedia.
McGraw-Hill Book Company. New York. 1974. pp. 27-28.
Encyclopedia of Polymer Science and Technology. Volume 1: Acrylic
Fibers, p. 352.
Reference 3. pp. 343-344.
, R.W. Man-Made Textile Fibers. In: Riegel 's Handbook of
Industrial Chemistry. Kent, 0. (ed). Van Nostrand Reinhold. New York.
1974. p. 332.
^.^Development Document for Proposed Effluent Limitations Guideline and
New Source Performance Standards for the Synthetic Resins Segment of
the Plastics and Synthetic Materials Manufacturing Point Source
Category. U.S. Environmental Protection Agency. EPA #940/1-73-010.
September 1973. p. 71.
Reference 11. pp. 80-85.
Reference 3. pp. 348-351.
Reference 1. p. 83.
56. Reference 3. p. 3.
3-43
-------
4. AIR EMISSIONS DEVELOPED IN SOURCE CATEGORY
4.1 PLANT AND PROCESS EMISSIONS
4.1.1 AN Monomer
Major sources of AN emissions from AN monomer manufacturing operations
are the absorber vent, column vents, product storage and handling vents,
and fugitive emissions. The AN emissions estimates in this report for the
various sources at a model 180,000 Mg/yr monomer manufacturing plant are
based on emission factors given by Hobbs and Key. Table 4-1 lists the
2 3
emissions factors as provided by the CMA and SRI for comparison. ' These
factors were not used for emissions estimates in this report because the
data were not identified as controlled or uncontrolled emissions and the
control methods that may have been used were not discussed.
The absorber vent gas consists of the gross reactor effluent after
stream neutralization and recovery of nitriles. The vent gas is composed
of approximately 97.25 weight percent inerts, 1.5 percent carbon monoxide,
4
1.25 percent total VOC, and 0.001 percent AN. The AN emission factor for
this vent is estimated to be 0.01 kg AN/kg AN produced. Model plant emis-
sions of AN from this source would be around 18 Mg/yr. Vent gas composition
is dependent upon the catalyst used, reactor operating conditions, raw
material purity, production rate, and absorber operating conditions.
Emissions of AN increase markedly when the absorber column overhead tempera-
ture increases. Vent emissions of AN and other hydrocarbons are also
influenced by the air feed rate to the reactor under normal operating
conditions. Absorber vent emissions increase during reactor startups, when
the stream composition varies continuously until normal operating conditions
are reached. The emission rate of AN during reactor startup is approximately
3.84 kg AN/hr as opposed to 2.05 kg AN/hr during normal operations. During
startup conditions, the absorber vent stream also has a higher concentration
4-1
-------
TABLE 4-1. SUMMARY OF ESTIMATED AN EMISSION FACTORS FROM MONOMER PRODUCTION
Emission factor (kg/Mg of monomer)
Source of estimate
Plant
Absorber (ox^dizer)
Control led
Column vents (flare)
Control led
Handling/Loading
Fugitive
Storage
Wastewater pond
TOTALS
Chemical Manufacturers Association
DuPont
Beaumont Memphis
0.02
0.07
0.07
0.02
0.01
0.09
0.26
1.20
0.07
<0.04
0.02
<0.10
<0.04
1.49
Sohio Monsanto
Lima Alvin Texas City
0.52 0.02 0.12
0.01 0.01 0.02
0.02 0.01 0.01
0.02 0.04 0.04
0.40 0.63 0.30
_ _ _
0.97 0.71 0.49
SRIb
American Cyanamid Model
West Wego plant
0.03
0.01
0.11
0.01
*
0.72
0.008
0.89-
0.04e
0.50
0.14
0.26
0.81
0.10
1.85
Hydrosciencec
Model plants
0.002
0.05
0.11-0.1
0.16
Total all
_
•x-1.32
7
storage
Source: Chemical Manufacturers Association, 1980. Emission controls for each plant are not specified, some sources
are uncontrolled. Fugitive emissions low owing to OSHA regulations.
Source: Suta, 1979. Emission factors were supplied to Stanford Research Institute (SRI) by EPA for use in the
population exposure analysis.
cSource: Hobbs and Key, 1978. Hydroscience, Inc., developed emission factors for the various processes using feasible
control options by a model plant analysis. Only absorber vent and column vent factors assume controls — all other
factors given are estimates of uncontrolled emissions.
Memphis and Lima plants are not controlled, American Cyanamid now installing controls.
Emission factor for DuPont, Memphis = 1.20 kg/Mg; American Cyanamid, Westwego = 3.0 kg/Mg.
-------
of VOC and some catalyst fines. This is a result of bypassing the quencher
and absorber (or absorber only) during the startup process. These conditions
last for about 1 hour, a reactor normally being shut down and restarted
about four times per year. Uncontrolled startup AN emissions from a two-
reactor production line would be approximately 31 kg AN per year.
Vent gases from the recovery, acetonitrile, acetonitrile purification,
light ends, hydrogen cyanide, and.product columns are composed of non-
condensables dissolved in the column feeds, uncondensed VOC, and, for
vacuum columns, air that has leaked into the columns and is removed by the
vacuum jet systems. There is little reliable data on the composition of
emission streams or the quantities of the various stream constituents;
therefore, a combined emission factor for all column vents was estimated at
5 kg AN/Mg AN produced. The estimated uncontrolled model plant AN emissions
from the combined column vents would then be approximately 900 Mg AN/yr.
Product storage tanks and handling facilities are another source of AN
emissions at AN monomer plants. The combined uncontrolled AN emissions
factor for the vents from crude AN, AN run, and AN product tanks is about
1 Kg/Mg AN produced. This translates into approximately 180 Mg/yr of AN
emitted by the uncontrolled model plant. The uncontrolled AN emission
factor for AN handling operations is approximately 0.272 Kg/Mg AN produced.
An uncontrolled AN handling facility at a model plant can thus be expected
to emit about 49 Mg AN/yr.
Fugitive emissions occur from leaks in the pumps, compressors, and
valves that handle process streams containing AN. The model plant is
assumed to have 25 pumps and 600 valves handling AN out of an estimated 50
and 1200 total, respectively. The estimated fugitive AN emissions factor
is 0.159 Kg AN/Mg AN produced. Uncontrolled fugitive AN emissions would
thus be 28.6 Mg/yr for the model plant.
Possible secondary AN emissions sources are the flare and incinerator
stacks and the deep well pond. Emissions of AN from the flare and incinerator
stacks are minimal, these streams being composed mostly of nitrogen, carbon
dioxide, and water. Plant wastewater sent to the deep well pond has less
than 0.02 percent by weight of AN. This fact, in conjunction with a VOC
emissions control efficiency of 92 percent afforded by a heavy lube oil
layer covering the deep well pond, is the basis for assuming that AN emis-
sions are very small.
4-3
-------
Table 4-2 summarizes the emission factors, characteristics, and emissions
from the possible sources of AN emissions at the model plant. Emission
factors for total VOC are included for comparison.
Estimates of total emissions of AN from monomer plants were prepared
by SRI and CMA and are listed in Table 4-37'8 along with the results of
this study. Emission estimates from SRI were developed using process-specific
emission factors supplied by EPA. These factors were developed by EPA in
previous studies conducted by Hydroscience and Pullman Kellogg. The CMA
study team for AN reviewed the SRI report and updated AN emission estimates.
The CMA figures reflect the use of plant-specific data as opposed to the
SRI model plant approach. Recent improvements in process and control
methods are incorporated in the figures. The CMA figures have not yet been
thoroughly evaluated.
4.1.2 Acrylic Fibers
The only nonnegligible uncontrolled AN emissions from acrylic fiber
production for suspension polymerization followed by wet spinning occur at
the pelletizer, polymer dryer, and crimper; for solution polymerization
followed by wet spinning, emissions occur at the spinning and washing steps.
The emission factors presented in Table 4-4 were developed by Click and Moore
o
of Pullman Kellogg for model plants producing 45,400 Mg (100 million pounds)
of acrylic fiber per year. Both uncontrolled model plants assume an AN
polymerization reactor conversion of 87 percent followed by vacuum flashing
to release 80 percent of the unreacted AN for monomer recovery by absorption/
stripping. The suspension polymerization model plant is assumed to have two
filter/wash stages each removing 37.5 percent of the AN in the incoming
polymer slurry. The solution polymerization model plant is assumed to
remove 70 percent of the remaining unreacted AN for recovey during the
washing step following spinning. State implementation plans (SIPs) do
not address acrylonitrile emissions specifically, but do address emissions
of all volatile organic compounds (total VOC). Therefore, the uncontrolled
model plant, which includes typical AN recovery for economic reasons, is
also a good representation of a plant satisfying SIPs. As the price of AN
monomer feedstock continues to increase, additional recovery/emission
control measures become more attractive. Also, improved enclosure and
capture of emissions is helpful in limiting worker exposure to AN, to comply
with OSHA requirements.
4-4
-------
IAIIIE 4-2. IINCONIROUED AMI) CONIROI.IED (MISSIONS AND MISSION FACIORS fOR AN AND VOC FROM A MODFL PI ANT
USING HIE SOIIIO PROCESS
in
.
Source
Absorber venl
(Normal) .
(Startup)"
Column vents (total)
Storage vents
Crude acrylonllrlle
Acrylonllrile run tanks
Acrylonllrlle slorage
llandl Ing
Acrylonllrlle.
Acryloniliile"
Fugitive0
Secondary
Incinerator
Deep we) 1 pond
TOTALS
Uncon
AN
0.10
0.187
5.00
0. 101
0.149
0.751
0. 167
0.105
0.159
-
6.719
"Model plant operating R760 hrs/yr at ISO
Vrnled to atmosphere to prevent possible
Lists 1 hour.
fly tank car.
'dy barge.
Emission
Kg emisslons/Hg
trolled
TotaTV'oC
100.0
0.244
10.00
0. 101
0.149
0. 751
0.167
0.105
0.326
0.360
13.00
125.203
factor AN emissions
AN produced Hg/yr
Controlled Uncontrolled Controlled
AN total VOC
0.0010
0.0019
0.0500
0.0010
0.0015
0.00/5
0.0017
0.0011
0.0154
-
0.081
,000 Kg capacity.
explosion In absorber Unes
1.00 18.0 0.18
0.0025 0.031 0.00031
0.100 900.0 9.0
0.0010
0.0015
0.00/5 Total slorage 180.2 1.802
0.0017
0.0011 Tolal handling 40.96 0.504
0.0310 28.6 2.86
0.360
1.100
2.606 1179.791 14.346
Yearly averaged value; 4 startups each of 2 reactors. Each startup
*Tslimaled total emissions assuming model plant has 25 out of 50 pumps and 600 out of 1200 valves handling acrylonltrlle.
Sourer: llobhs anil Key, 1978. llydroscience. Inc.
-------
TABLE 4-3. SUMMARY OF ESTIMATED TOTAL AN EMISSIONS FROM MONCMER PRODUCTION
i
en
Plant and City
An. Cyanamid
Westwogo
du Pont de Noinours
Beaumont
Monsanto
Texas fifty
du Pont de Nemours
Mcmph 1 s
Sotilo (Vlstrnn)
rtiiia
Soli in (Vfstron)
Victoria
Monsanto
AlvTn"
County and State
Jefferson
LA
llardln
TX
Calves ton
TX
Shelby
Allen
m —
Victoria
TX
Bra/orla
TX
Total AN
emissions
AN emissions (Mg/yr) (Mg/yr)
Process Storage Fugitive EEA SRI CMA
71.8 19.3 . 3.6 94.7 578 107
23.4 4.1 51.3 78.8 294 43
46.8 56.4 58.5 161.7 353 94
185.5 17.7 N/A 203.2 367 187
72.1 57.1 2.7 131.9 335 176
-
27.6 33.3 34.5 95.4 370 140
Comments
Data obtained from Section 114
letters and follow-up contacts.
Fugitive AN emission figure In-
cludes estimated process equlp-
ment emissions and settling pond.
ship and barge operations, flare
vent, and storage tank vent.
Process and storage enlsslon fig-
ures calculated from Monsanto
emission factors In 114 response.
Fugitive enlsslons not available.
Did not receive questionnaire.
Emissions estimate based on follow-
up of previously collected data.
New plant - not in operation.
Did not receive questionnaire.
Emissions prorated based on plant
capacity and data from the Texas
City plant.
TOTAL 766 2279 747
Cncrgy and Environmental Analysis, Inc. (EEA)
SOIIRCF: P1.»nt visit and Section 114 questionnaires.
-------
TABLE 4-4. ESTIMATED UNCONTROLLED EMISSIONS FROM A MODEL PLANT
PRODUCING 45,500 Mg/Yr OF ACRYLIC FIBER
Emission Factors
(kg emissions/
Mg fiber produced)
Source
Suspension Polymerization:
Pelletizer
Polymer Dryer
Solvent Scubber Vent
Crimping
Setting Dryer
Total
Solution Polymerization:
Monomer Recovery
Scrubber Vent
Spinning, Washing
Vent
Total
AN
1.15
10.5
0.0
0.05
0.0
11.7
0.0
9.0
9.0
Total
VOC
1.15
10.5
1.0
4.05
5.0
21.7
0.1
_9.9_
10.0
Emission Rate
(Mg/yr)
Total
AN VOC
SI 52
480 480
0 46
2.3 180
0 230
530 990
0 4.6
410 450
410 455
Source: Click and Moore, April 1979, p. 103-104.
4-7
-------
The AN and VOC emissions from an uncontrolled suspension polymeriza-
tion model plant's filtration reslurry tank and AN recovery absorber vent
were estimated as negligible. AN emissions were also estimated as negligible
from the solvent scrubber vent and setting dryer. AN emission factors and
emissions were estimated by Pullman Kellogg to be 1.15 kg AN emitted per
Mg fiber produced or 52 Mg/yr from the polymer pelletizer, 10.5 kg/Mg or
480 Mg/yr from the polymer dryer, and 0.05 kg/Mg or 2.3 Mg/yr from crimping.
The annual emission rates of AN are for the model plant with a capacity of
45,500 Mg/yr. AN process emissions estimates total 11.7 kg/Mg or 530 Mg/yr
for this model plant. ,
The AN and VOC emissions from the uncontrolled solution polymerization
model plant were estimated as negligible from the solvent purification vent
and from all of the finishing operations. Emissions of VOC other than AN
were expected from the AN monomer recovery scrubber. The only process
source with major estimated AN emissions is the spinning and washing vent
with 9 kg/Mg or 410 Mg/yr. Although the amount of AN in this stream is
quite high, the concentration is low because of the large amounts of air
(as much as hundreds of cubic feet per minute) used to exhaust the spinning
and washing area.
Monomer storage tanks are also a source of AN emissions. Emissions
from uncontrolled (fixed roof) tanks range from about 2 to 30 Mg/yr per tank,
depending on the tank size, usage patterns-, and weather conditions. Some
plants use control techniques such as floc.fi rig roofs or venting to nearby
scrubbers to recover monomer and/or reduce emissions from selected tanks to
2 Mg/yr or less. Equations are available for calculating emissions from
storage tanks containing volatile organic liquids.
No industry-specific data on fugitive emissions or the number of their
common sources (pumps, valves, etc.) are available for acrylic fiber plants.
The total fugitive AN emissions from a fiber operation have, therefore, not
been estimated at this time.
Several estimates have been made of total national emissions from
acrylic fiber plants. Pullman Kellogg estimated total AN emissions of
4748 Mg in 1977 by prorating, on the basis of capacity, the emissions
reported by industry for some plants up to estimates for the entire industry
12
segment. SRI generated a national estimate of 4698 Mg/yr using process-
4-8
-------
specific emission factors supplied by EPA. The CMA reviewed the SRI
report and updated industry AN emission estimates. The national total AN
emissions estimated by CMA are only 1361 Mg/yr, reflecting recent process
14
and emission control changes. The CMA data have not yet been thoroughly
evaluated by EPA. The CMA and SRI plant-specific estimates along with the
results of this study are presented in Table 4-5.
4.1.3 ABS/SAN
Plants manufacturing ABS/SAN resins emit AN to the atmosphere from
process equipment vents, storage tank vents, and fugitive emissions from
process streams. Process equipment AN emission sources include reactors,
absorbers, and dryers as discussed in the ABS process description. Fugitive
emissions result fr^om pumps, valves, and flanges. Control methods are
discussed in Section 5.2.3 of this report.
AN emissions estimates (controlled and uncontrolled emissions) were
made using data obtained from the individual manufacturers through Section
114 requests and plant visits. Visits were made to the Borg-Warner Chemicals,
Washington, West Virginia, and Monsanto Plastics and Resin Company, Addyston,
Ohio, plants.
The estimated uncontrolled plant emissions for a model 45,500 Mg/yr
operation were calculated using previously developed data. Storage tank
losses were estimated using AP-42 emission factors. Total uncontrolled
emissions for the model ABS/SAN plant are 491 Mg/yr. Emssions estimates
for all ABS/SAN operations releasing AN to the atmosphere are given in
Table 4-6.
4.1.4 NBR Elastomers
Nitrile rubber manufacturing plants emit AN to the atmosphere through
process vents, storage tanks, and fugitive emissions sources. The process
sources include reactors, steam strippers, and product finishing area as
discussed in the NBR process description. Fugitive emissions are discussed
in Section 5.2.3 of this report.
AN emissions estimates (controlled and uncontrolled) were made from
data requested from the individual manufacturers through Section 114 requests
and plant visits. The estimated uncontrolled plant AN emissions for a
model 23,000 Mg/yr nitrile elastomer manufacturing plant were calculated
using previously developed EPA information. Storage tank losses were
4-9
-------
TARLF. 4-5. SUMMARY Or ESTIMATFO TOTAL AN EMISSIONS FROM ACRYLIC FIBER PRODUCTION
Plant and City
American Cyanamld
Hi Mnn
Badlsche
Du Pont
Camrfen
Du Pont
Waynoshoro
Tennessee Eastman
Klnqsport
i Monsanto
^ fiocafur
AN emissions (M9/Xr)
County and State
Santa Rosa
FL
James City
VA
Kershaw
SC
Augusta
Sullivan
TN
Morgan
Process Storage Fugitive
115.7 9.3
337.7 19.1
449 0.4
?83.1 19.5
24 I
3?. 9 ?4.7
TOTAL
17.2
N/A
N/A
6.6
N/A
N/A
Total AN
emissions
(Mg/yr)
IfA SRI
14?.? 91
356. B 7Z6
457.8 4BO
309.? 338
?5 69
57.6 ?994
1319 4598
CMA Comments lOrCILt
91 ^wi '^L ir j^ir~f<5H
395 Fugitive emissions not available.
353 Rased on data collected In 1978
339 Rased on data collected In 1978
69
114 Fugitive emissions not available.
1361
Source: Industry Supplied Data
-------
TABLF 4-6. AN HUSSIONS FROM ABS/SAN RESIN OPERATIONS
Total AN
' emissions
AN emissions (Mg/yr) / (Mg/yr)
Plant and City
Abtcc (Mobay)
Louisville
Born-Warner
Washington"
Borg-l/arner
Ottawa
Dow
Torrance
Dow
Dow
Pevlcy
Dow
UTTyns Point
Monsanto
AdHys ton
Monsanto
Musr.atine
Monsanto
USS Chemical
Scotts Bluff
County and State
Jefferson
KY
Wood
La Salle
IL
Los Angeles
CA
Midland
HT
Jefferson
MO
New London
CT
Hamilton
T5fi
Mu sea tine
IA
Hampdcn
East Baton Rouge
LA
Process Storage Fugitive
4.1 N/A 125 15
^.5
657 1769 1769
96.6 387 387
9.1 9 9
17.3 15 15
1.1 6 6
7.9 8 8
09.6 163 84
365 363 365
10.0 27 10
157.9 154 175
1416 3026 2043
Comments
Storage emissions data not ^
available.
Emission reductions achieved by
AER systan.
Did not receive questionnaire.
Did not receive questionnaire.
Emission estimates based on previously
collected data.
Did not receive questionnaire.
Ninbers based on old EPA data.
Did not receive questionnaire.
Emission estimates based on previously
collected data.
Did not receive questionnaire.
Data from plant visit. 2/4/81.
Did not receive questionnaire.
Numbers based on old EPA data.
Data from Section 114 response,
March 1981.
Did not receive questionnaire.
Emission estimates based on previously
collected data.
Sourer. Industry Supplied Data
-------
estimated using AP-42 emission factors. Total uncontrolled emissions for
the model plant are 228 Mg/yr.
Estimated total AN emissions from nitrile elastomer operations are
given in Table 4-7. The emission figures were obtained from the manufac-
turers during this and previous studies.
4-12
-------
TABLE 1-7. AN MISSIONS FROM NITRILE ELASTOMER OPERATIONS
Plant and City
Copolymer Rubber
llatnn Rouge
Goodrich
Akron
Goodrich
LoulsvlTle
Goodyear
Trtron
Goodyear
Houston
Rclchold
thpswnld"
Unl royal ,
Pa fnesvll le
County and State
East Baton Rouqe
LA
Surmlt
Oil
Jefferson
KY
Summit
T5JI
Harris
T5T
Kent
Lake
OlT~
AN emissions
Process Storage
3.4 0.9
Jg^5" "/A
J3?r6 N/A
* •* V
90.6 0.25
340.9 1.0
5.4 0.2
32.8 6.1
TOTAL
Total AN
missions
(Mg/yr) (Mg/yr)
fugitive F.EA SRl CHA
N/A 4.3 1 1
(j£rt; (^O All 123
N/A 3afT6 303 254
(1^1
90.9 91 91
340.9 79 79
2.8 8.4 not 6
Inc.
Included In 38.9 53 40
process emis-
sion estimate
9?8 650 594
Comments
Emissions calculated from re-
sponses to EPA Inquiries by Pull-
man Kellogg In 1978. Fugitive
emissions not shown by Copolymer.
Storage emissions are not available.
Storage and fugitive emissions
are not available. Emissions based
on previously collected data.
Did not receive questionnaire.
Emissions based on previously collected
data.
Did not receive questionnaire.
Emissions based on previously collected
data.
From correspondence with EPA
7/21/78 and 10/24/78.
CHA emissions reported after new
steam stripping equipment was
added.
Source: Industry Supplied Data
-------
REFERENCES FOR CHAPTER 4
1. Hobbs, F.D. and J.A. Key. Hydroscience, Inc. Emissions Control
Options for the Synthetic Organic Chemicals Manufacturing Industry.
Acrylonitrile Product Report for EPA Contract No. 68-02-2577. August
1978. pp. IV-2, V-2.
2. Chemical Manufacturers Association (CMA). Acrylonitrile Emission
Estimates. Washington, D.C. -December 19, 1980.
3. Suta, B.E. SRI International. Assessment of Human Exposure to Atmospheric
Acrylonitrile. Report for EPA Contract No. 68-02-2835, Task 20.
August 1979.
4. Reference 1. p. IV-3.
5. Reference 1. p. IV-4.
6. Hughes, T.W. and D.A. Hour. Monsanto Research Corporation. Source
Assessment: Acrylonitrile Manufacture (Air Emissions). EPA Contract
No. 68-02-1874. September 1977. pp. 21-22.
7. Reference 2.
8. Reference 3.
9. Click, C.N. and D.O. Moore. Emission, Process and Control Technology
Study of the ABS/SAN, Acrylic Fiber, and NBR Industries. Pullman
Kellogg. Houston, Texas. Final Report for EPA Contract No. 68-02-2619,
Task No". 6. April 1979. pp. 87-105.
11. Reference 9. Control of Volatile Organic Emissions from Volatile Organic
Liquid Storage in Floating, and Fixed Roof Tanks. Preliminary Draft Final
Report for EPA Contract No. 68-02-3168. January 1981. 91 pp.
12. Reference 9. Wallace, M.J. Controlling Fugitive Emissions. Chemical
Engineering. August 27, 1979. pp. 78-92.
13. Reference 3.
14. Reference 2.
15. Reference 9.
16. Reference 9.
4-14
-------
5. EMISSION CONTROL SYSTEMS
This chapter discusses the air pollution control techniques applicable
to reducing AN emissions from each industry segment. Current control
methods and alternative control technologies are covered for each AN emis-
sion point at the various processes. Section 5.1 presents an outline of
the control techniques which can be applied to each of the four AN industry
segments. These techniques are non-process specific and concern general
plant management practices and AN storage and handling procedures. They
include control methodologies for storage tank, loading operation, and
process fugitive emissions. Section 5.2 deals with control techniques for
process vent streams and is divided into four sections. Each section
covers process controls for one of the four industries either producing or
consuming AN.
5.1 STORAGE AND FUGITIVE EMISSION CONTROLS
This section discusses emission control methodologies for process
fugitive emissions, storage tank emissions, and transfer and loading opera-
tion emissions. These controls are applicable across all four industries
which produce and consume AN. At present, varying control techniques are
used to reduce emissions from these sources in the different industries.
Many of these control practices are focused at minimizing product losses.
Others are required by State and local government regulations.
5.1.1 Current Controls
5.1.1.1 Current Controls for Process Fugitive Emissions. There are
currently no regulations or standard work practices for the reduction of
fugitive emissions in the AN monomer ABS/SAN, and acrylic fiber and NBR
industries. The OSHA standard (effective in November 1978) is directed at
limiting worker exposure to AN. It requires that exposure not exceed
5-1
-------
2 ppnv over an 8-hour time-weighted average or 10 ppnv over any 15-ninute
period. This standard does not specifically require AN emissions reduction.
5.1.1.2 Current Controls for Storage Tanks. Storage tanks in the AN
industry are either floating or fixed roof bulk storage tanks, other large
fixed roof storage tanks, or smaller "day" tanks. Generally, bulk tanks
are external floating roof tanks or fixed roof tanks with internal floating
roofs. These are employed at monomer facilities for finished product
storage and are used by fiber, ABS/SAN, and nitrile rubber producers as
primary AN monomer storage facilities. Turnovers normally run 10 to 20 per
year. Large fixed roof tanks are used for other purposes such as crude AN
storage at monomer facilities. Smaller "day" tanks are used by the AN-
consuming industries and feed directly into process operations. These
normally have capacities of approximately 113 m and have more frequent
turnovers with one cycle taking several days or a week. Day tanks are
often fixed roof tanks controlled with internal floating roofs, although
sometimes these tanks have fixed roofs with no controls.
Information available specifically characterizing storage tank controls
in the SXMI, ABS/SAN, fiber, and nitrile rubber industries is limited.
However, a wide variety of techniques are known to be in use. For example,
AN monomer producers use floating roofs, chilled water scrubbers, vent
condensers, absorbers, and variable vapor spaces to control AN emissions
from storage tanks. The AN-consuning industries most commonly use internal
or external floating roofs. Only scattered information on exact control
efficiencies has been obtained; however, chilled water scrubbers and absorbers
will normally achieve a minimum of 90 percent control efficiency. Control
efficiencies for internal and external floating roofs are discussed in
Section 5.1.2.2.
5.1.1.3 Current Transfer and Handling Controls. Limited information
has been obtained on control techniques used in transfer and loading opera-
tions. Emissions from these operations could potentially occur at monomer
plants, where AN is loaded into railcars or barges, and at ABS/SAN, fiber,
and elastomer facilities, where monomer is received and unloaded into bulk
storage tanks.
Emissions from loading operations are controlled at two monomer facil-
ities with the use of flares. Emissions from unloading operations at
5-2
-------
ABS/SAN, fiber, and nitrile elastomer plants may currently be controlled
where bulk external floating roof tanks are present. In this case, there
is no vapor space that must be displaced from the storage tank, and ambient
air may displace the monomer within the railcar or barge. Where fixed roof
tanks are loaded, control may be achieved by a flare, vapor balance, or
vapor recovery system. Many States require some form of vapor control
system in their draft SIPs (see Chapter 7).
5.1.2 Available Control
5.1.2.1 Fugitives. The EPA is currently developing an NSPS for
emissions of VOC in the synthetic organic chemical industry. These guide-
lines focus on reducing fugitive emissions from process pumps and valves,
and give recommendations on how these emissions reductions can be achieved
through the use of available control techniques for improved operation,
maintenance, and housekeeping practices and selection of proper equipment
for leak prevention. It is estimated that through the use of these
recommended guidelines that fugitive emissions from the affected plants may
be reduced by 87 percent.
The use of a regularly scheduled leak detection and repair program
inconjunction with use of recommended equipment achieves significant
reduction in fugitive AN emissions from process, storage, and transfer and
loading operations. If abatement comparable to what could be achieved
within SOCMI is accomplished, this would result in approximately a 87 percent
emissions reduction. There would be raw material savings from the imple-
mentation of these programs and, owing to the price of AN, there could
potentially be net benefits.
5.1.2.2 Storage Tanks. Substantial emission reductions can be achieved
through the retrofit of existing storage tanks with evaporative and working
emissions control systems. The EPA has recently examined emissions controls
for fixed and floating roof storage tanks. These controls and potential
emissions reductions are presented in EPA documents concerned with control
2
of VOC emissions from storage tanks.
5-3
-------
Potential emissions reductions achievable through the implementation
of controls suggested in the EPA studies are presented in Table 5-1. These
estimates are based on emissions from benzene storage. (Benzene has a
vapor pressure of 1.5 psia at 70°F; AN has a slightly higher vapor pressure
of 1.8 psia at 70°F; therefore, these emission reduction estimates should
be comparable.)
The most effective controls for fixed roof storage tanks, found in the
EPA study, are a contact internal floating roof with liquid-mounted primary
seals and rim-mounted continuous secondary seals. The estimates are that
an 85 percent emissions reduction is possible when these controls are
3
installed on an uncontrolled fixed roof storage tank of 151 M capacity.
This size is roughly comparable to day tanks used in the AN-consuming
industries. Control efficiencies of greater than 90 percent can be obtained
through the- use of recommended EPA controls on large fixed roof storage
tanks. The suggested controls for external floating roof tanks (assumed to
be equipped with a primary seal) are the addition of a rim-mounted continuous
secondary seal and the construction of a fixed roof. Estimated AN emissions
reductions are 93 percent with these controls.
Potential emissions reductions from various levels of control of fixed
and floating roof AN storage tanks are presented in Tables 5-2 and 5-3.
These estimates were developed from algorithms presented in draft EPA
documents and adjusted for AN vapor pressure, density, and molecular weight.
They are presented to show emissions reductions possible from uncontrolled
tanks and the incremental reductions possible by bringing partially con-
trolled tanks into line with various control options.
The estimated emission reduction for an uncontrolled fixed roof tank
(5x7 M, 151 M ) equipped with a contact internal floating roof and liquid-
mounted primary seals is 76 percent. An additional 12 percent emission
reduction to 88 percent control can be achieved with a rim-mounted secondary
seal.
For an existing external floating roof tank (19x12 M, 3483 M capacity)
with primary seals, a 67 percent emission reduction is estimated with the
addition of a rim-mounted continuous secondary seal. A fixed roof built
%
over a tank with primary seals only has an estimated 86 percent reduction.
If a roof is built in addition to secondary seals, a 93 percent emission
reduction is estimated.
5-4
-------
TABLE 5-1. MODEL STORAGE TANKS AND DUSSIONS REDUCTIONS
(assunws July 1900 AN prke of 37
-------
TABLE 5-2. POTENTIAL EMISSIONS REDUCTION FOR SMALL FIXED ROOF
AN STORAGE TANK
Tank size
Level of control
Emissions reduction
Smal1 fixed roof tank
(such as day tank)
@ 151 M3 capacity
Uncontrolled
Internal floating roof
with primary seal only
Internal floating roof
with primary and
secondary rim-mounted
continuous seal
76%
88%
5-6
-------
TABLE 5-3. POTENTIAL EMISSIONS REDUCTION FOR EXTERNAL FLOATING
ROOF TANK
Tank size
Level of control
Emissions reduction
External floating
roof tank
(? 3483 M3 capacity
(bulk storage)
Uncontrolled
(primary seal only)
Primary and
secondary seal
Fixed roof; contact
internal floater with
primary seal only
Fixed roof; contact
internal floating roof
with primary and
secondary seal
62?
86*
93*
5-7
-------
Substantial emissions reductions could potentially be achieved by
applying controls to existing .uncontrolled AN storage tanks and by adding
incremental controls to those tanks already partially controlled. The
increased price of AN affords plants using these controls potential net
benefits through conservation of raw material as shown in Table 5-1. The
emission reduction and annualized cost estimates from EPA studies of organic
liquid storage in conjunction with a July 1980 AN price of Bit/Kg ($814/Mg)
indicate a net benefit from instituting improved controls for a large fixed
roof and external floating roof tanks. A model large fixed roof tank can
realize material recovery credits that would outweigh 1980 annualized costs
by $1510. The model external floating roof tank RACT controls would bring
a net benefit of $7561 in 1980 dollars. The larger the storage tank, the
greater the emissions reduction and net benefits that can be realized. The
EPA guidelines are therefore a potentially attractive means of reducing AN
emissions.
5.1.3 Loading Facilities
Potential control methods for loading facilities is an active vapor
balance or control system which condenses, absorbs, adsorbs, or incinerates
AN vapors. These systems would control AN emissions during draining and
filling of storage tanks or railcars and barges transporting AN monomer.
Vapor balance and control systems following EPA guidelines (tank truck
loading terminals and bulk gasoline plants) are capable of achieving 87 to
4
97 percent control. In the former case, the control method is a condenser,
absorber, adsorber, or incinerator. These may be used in loading barges or
railcars from floating roof tanks where the air within the transport vehicle
cannot be displaced to the tank. Vapor balance systems may be used where
loading or unloading transport vehicles from or to fixed roof storage
facilities. In both cases, leakage from the control system and transport
vehicle must be minimized by a good inspection and maintenance program.
5-8
-------
5.2 PROCESS CONTROLS
5.2.1 AN Monomer
Standard methods of emissions controls such as thermal oxidizers,
flares, and scrubbers are commonly used by the AN manufacturing industry.
Table 5-4 is a listing of emission points and control devices currently
used by domestic AN manufacturers.
Emissions from the absorber vent are commonly controlled by combustion
devices. The VOC emissions are pyrolyzed, oxidized, and converted to
carton dioxide and water. The problem of NO emissions from combustion of
^
nitriles can be eased by sophisticated techniques such as staged combus-
tion. Reduction of VOC emissions by 98 percent can be expected with properly
designed and operated thermal oxidizers. Catalytic oxidizers can achieve a
high degree of HC emissions reduction without emitting high levels of NO
as they operate at lower temperatures. However, depending upon the catalytic
oxidizer system and the waste gas components, catalytic oxidizers may also
have a high rate of unburned hydrocarbon passthrough. Carbon adsorption is
unsuitable for absorber vent emissions control because the dilute gaseous
pollutants are of low molecular weights and will not be efficiently absorbed.
During reactor startup, the absorber vent gas continuously changes in
composition and has a higher concentration of AN than during normal operation.
Flaring is a control method that is traditionally used for variable flow,
intermittent streams such as occur during startup conditions. Combustion
of these nitrile vapors leads to high emissions of NO . Since the absorber
vent stream is more concentrated during reactor startup, an emissions
control system consisting of a water scrubber followed by carbon adsorption
has been recommended for further study.
Emissions from the column vents and some storage tank vents are commonly
controlled by flaring. As mentioned before, combustion of nitriles can
lead to very high emissions of NO . Flaring also has the disadvantage of
^
allowing large amounts of VOC to pass through if existing weather conditions
are windy. Thermal or catalytic oxidizers are optional control methods
which may be used for column vents emissions control.
Scrubbers are frequently used as control devices for emissions from AN
storage and loading. Gaseous emissions from storage and loading are passed
5-9
-------
TABLE 5-4. CONTROL DEVICES CURRENTLY USED BY THE AN INDUSTRY
Company
Control devices at various emission points
Absorber vent
Column vents
Storage tank vents
Deep well pond
American Cyan amid
DuPont
Beaumont, TX
Memphis, TN
Thermal oxidizer
Catalytic oxidizer
None
Flare
Flare
Flare
Scrubbers
Scrubbers, refrigerated
condenser, and flare
Scrubber3
Lube-oil cover
Lube-oil cover
Noneh
Monsanto
Al vin
Texas
Vistron
, TX
City, TX
Thermal
Thermal
None
oxidizer
oxidizer
Flare and vent
condenser
Not reported
Flare
Not reported
Not reported
Flare3
Lube -oil
Lube-oil
None
cover
cover
Some vents go directly to the atmosphere from conservation vents.
No deep well pond, part of plant wastewater 1s concentrated and Incinerated; remainder is treated and sent to
municipal sewer.
Source: (1) Mobbs and Key, 1978. Hydrosclence, Inc.
(2)
Indus try-Supplied data.
-------
through absorption columns and the column bottoms recycled to the process.
Economics and competition in the industry has led to increased product
recovery. Venting emissions from product storage and handling directly to
the atmosphere from conservation vents and flaring have become undesirable
with rising prices. The use of vent condensers and floating roof tanks is
rapidly becoming more attractive. Carbon adsorption and refrigerated
compression systems are also possible methods of product recovery/emissions
control from product storage and handling. The estimated costs and control
efficiencies of these control systems at a new monomer plant are listed in
Table 5-5.
Although deep well ponds emit large quantities of hydrocarbon pollu-
tants, wastewater from AN manufacture contains relatively small amounts of
P
AN. The heavy lube oil cover used at most plants for emissions control
has a VOC reduction efficiency of 92 percent. Plant wastewater nay be
0
treated by solvent extraction. Some plant wastewater may also be diverted
to the plant incinerators in case of well injection pump failure.
Other approaches to emission control from AN monomer manufacture
involve process changes. Since VOC emissions occur from incomplete con-
version in the reactor, the industry has concentrated upon the development
of more selective catalysts. Escalating costs for raw materials and control
equipment operation have encouraged the search for more selective catalysts
to increase AN production while lowering the amount of by-products. This
could make waste streams easier to handle and AN emissions could be more
easily controlled. A new process developed by the Badger Company has the
potential for becoming the "cleanest" way to manufacture AN. The process
involves the selective absorption of AN from quenched reactor effluent in a
countercurrent absorption column by using a hydrocarbon solvent. The AN
and solvent are removed as the bottom stream while the hot absorber over-
head gases are incinerated. The column bottoms are sent to a "lights"
column to remove volatile by-products. The bottoms from the lights column,
containing AN in the solvent, are sent to the product column where nearly
pure AN is distilled from the solvent. Although the economic feasibility
of the process has not yet been evaluated, the process facilitates the
disposal of waste products by incineration. Thus, wastewater treatment and
stripper corrosion problems owing to the handling of sulfuric acid are
5-11
-------
TAtllF 5-5. CONTROLS AND ESTIMATED COSTS TOR AN MISSIONS REIUtTION At NFW WNmER PLANTS3
Source
Reactor startup
Recommended
Control
? Sys tern
Control
Efficiency
(X)
Estimated Costs (19801
Capital Annual! zed
($1000) (tlOOO/yr)
f.imniion t
Dare (dedicated)1
ro
Absorber vents 8
colinin vents
Cohmn vents ft MCN
storage ft handling
Thermal ox Id I/or
lleat recovery
Nr» heat recovery
Flare
Crude acrvlnnt tr lie Water scrubber
storage'
Product storage ft
handling"
Water scrublcr
90^
Water scruhher/ . 99
Carbon adsorption
98
90
99
99
300
370
4300
2ZOO
200
95
240
90 Very high NO emission expected -
29,000 p|»n NO at IOOX fuel nitrogen
conversion Including auxiliary fuel.
60 Adsorption alone for high concentra-
tions lias an explosive hazard and
would lie very expensive. Scrubber
alone would attain 901 control at
high cost. Emissions could be
vented to scrubber for crude storage
tanks.
Operating cost for case with heat
90 recovery fuel credits for recovered
6400 steam In use at some Installations.
60 Emissions ducted to existing emer-
gency flare system; capital costs
Include only ducting and utilities
arc an allocated portion of total
needed for flare system.
20 DeIng employed at ftifbnt and
American Cyanamld plants.
(00) These scrubbers present a net saving
of product - costs are offset by
product recovery.
aAII costs have been updated to real (constant) November 1900 dollars. Cost estimates have not been thoroughly
ev.iliiat.cd In light of current state-of-the-art and economics.
"nasod on Schwartz, et al., 1975. Air Products developed cost estimates for a msdcl plant with 9I.OOOHg/yr capacity.
rli» estimate only. This Is not an established or confirmed efficiency for a flare.
llaspd on Anc/tiln and Anderson. 1979. Acr.urex developed cost estimates for a model plant with 9l,OOOMg/yr capacity.
Pfrom llolihs and Key, 1970. Hydro science estimated costs (*10X to -30t accuracy) for a model plant with capacity of
IRfi.OOO Hi|/yr and operating 0760 hrs/yr.
-------
eliminated. Also eliminated is the operation of ammonium sulfate recovery.
5.2.2 Acrylic Fibers
The types of control options in use by this industry segment were
outlined in the Pullman Kellogg study. Since the time of that study
(1979), the only reported major changes are that better designed units have
been installed. The increased price of acrylonitrile, however, has become
a greater impetus to conservation and recovery measures.
Table 5-6 lists the AN controls in use by the various manufacturers.
Activated carbon can be used to adsorb AN from dilute process streams.
Water scrubbers are commonly used to control streams containing AN — parti-
cularly at process vents or storage tanks. High conversion reactors can
reduce potential emissions downstream by leaving less AN monomer unreacted.
However, development of high conversion technology for a specific process
by a particular manufacturer can be difficult and costly and its use may
affect product characteristics. Mechanical seals on agitators prevent
fugitive emissions. Slurry or solution stripping of AN from the polymer
using steam appears to be an effective control measure as it both reduces
potential emissions downstream by reducing the concentration of unreacted
AN to 150 to 500 ppm and allows condensation/recovery of AN-rich vapors.
Polymer stripping must be developed for each particular polymer blend and
process to maintain product quality and recover unreacted monomer. Strippers
and scrubbers are also used to recover AN from water streams for recycle.
AN recovery and subsequent recycle is a normal part of acrylic fiber manu-
facture as it is crucial for favorable process economics. Washing and
filtration steps are an integral part of most suspension polymerization
plants as the polymer is dewatered before drying; the AN content of the
polymer is also reduced at these steps. A vacuum flash step following
polymerization can reduce polymer AN content by about 80 percent. As much
as 70 percent of the unreacted AN in the spinning dope can be recovered by
the solvent concentration and AN recovery sections of a solution polymeri-
zation plant. A corresponding reduction in the AN emissions from spinning
and washing (the largest sources in solution polymerization) is achieved.
Chemical adducts have also been used to lower the residual AN content in
the spinning dope.
5-13
-------
TABLE 5-6. EXISTING AN CONTROLS IN THE ACRYLIC FIBERS INDUSTRY
10
American
Cyanamld
Dow
Badische
Dupont
Tennessee
Monsanto Eastman
AN Removal By
Act. Carbon
ILO Scrubbers
For tank &
Process Vents
High Conversion
Reactors
Mech. Seals for
Agitators
Slurry on
Solution Stripping
AN Stripper
AN Removal By
Washing &
Flltaratlon
AN Removal By
Vaccum Flash
AN Recovery From
Dilute Solvent
Chemical Adduct
x
x
x
x
af1odacry11c fibers.
-------
5.2.2.1 Alternative Control Techniques for Acrylic Fibers. Alternative
control techniques suggested and developed into model plants by Pullman Kellogg
are sunmarized in Table 5-7. The model plant control options for suspension
polymerization followed by wet spinning are: (1) slurry suspension stripping
to 500 ppm (dry wt.) reducing pelletizer emissions from 1.15 to 0.02 kg/Mg,
polymer dryer emissions from 10.5 to 0.13 kg/Mg, and total model plant
emissions from 11.7 kg/Mg to 0.5 kg/Mg or 27 Mg/yr; (2) a high conversion
(95 percent rather than 87 percent) reactor and an additional wash/filter
stage (increasing AN removal efficiency from about 60 percent with two
stages to about 75 percent with three stages) reducing pelletizer and
polymer dryer emissions to 0.25 and 2.10 kg/Mg, respectively, and total
model plant emissions to 2.4 kg/Mg or 110 Mg/yr. The model plant control
options for solution polymerization followed by wet spinning are: (1) solu-
tion stripping with steam to 500 ppm (dry wt.) reducing the spinning emission
factor from 9 to 0.45 kg/Mg or 20 Mg/yr for the model plant; (2) enclosure
of the spinning and washing section and venting to an incinerator (98 percent
assumed efficiency) reducing AN emissions from 9 kg/Mg to 0.45 kg/Mg or
20 Mg/yr. The associated estimated costs (roughly updated) for these control
options are presented in Table 5-8. For each process, control option 1 is
expected to be less costly on total annualized cost basis. It should be
noted that the control options are not mutually exclusive - they could be
employed jointly or separately. The enclosure of the spinning/ washing
section with movable plastic shields is becoming common even in combination
with slurry stripping due to OSHA regulations on AN concentrations in the
workplace. The exhaust from the spinning/ washing section, however, is
usually vented directly to the atmosphere and is a low AN concentration,
high air flow stream.
5.2.2.2 Emission Reduction Systems for Acrylic Fibers. Based on the
estimated control efficiencies and costs from the Pullman Kellogg study and
on information from plant visits, polymer stripping appears to be an excellent
emission reduction system. Although each manufacturer justifiably considers
its stripping operation unique because of the variations in polymer and
process, polymer stripping in general is widespread throughout the industry.
Extensive pilot and shakedown work for each product and process line is
required, however, to ensure that polymer stripping does not degrade
5-15
-------
TABLE 5-7. ESTIMATED EMISSIONS FROM MODEL PLANTS PRODUCING
45,500 Mg/yr OF ACRYLIC FIBER USING VARIOUS CONTROL OPTIONS
en
Emission Factor (kg An emitted/Mg Emission Rate Mg An emltted/yr
fiber produced}
Control
Uncontrolled
Source
Suspension Polymerization:
Stripper Vent
Pelletlzer
Polymer Dryer
Solvent Scrubber Vent
Crimping
Setting Dryer
TOTAL
Solution Polymerization:
Stripper Vent
Monomer Recovery
Scrubber Vent
Spinning Washer Vent
Incinerator Inlet
Incinerator Outlet
TOTAL
AN
1.15
10.5
0
0.05
0
11.7
___
0
9
—
___
9.0
Total
VOC
1.15
10.5
1
4.05
5
21.7
_-._
0.1
9.9
—
___
10.0
Option 1
AN
0.3
0.02
0.13
0
0.05
0
0.5
0.3
0
0.15
—
___
0.45
Total
VOC
0.3
0.02
0.13
1
4.05
5
10.5
0.3
0.1
1.05
—
___
1.45
Control
Option 2
Total
AN VOC
0.25 0.25
2.10 2.10
0 1
0.05 4.05
0 5
2.4 12.4
0 0.1
9 9.9
9 10
0.45 0.5
0.45 0.5
Control
Uncontrolled
Total
AN VOC
52
480
0
2.3
0
530
___
0
410
—
— -
410
52
480
46
180
230
990
___
4.6
450
—
—
460
Control
Option 1 Option
2
Total Total
AN VOC AN VOC
14
0.9
5.9
0
2.3
0
23
14
0
6.8
—
—
20
14 -
0.9
5.9
46
180
230
480
14
4.6
48
—
66
11
96
0
2.3
0
110
___
0
410
410
20
20
11
96
46
180
230
560
_ —
4.6
450
460
23
23
Source: Pullman Kellogg, April 1979, p. 103-104.
-------
TABLE 5-8. CONTROL OPTIONS AND ESTIMATED COSTS FOR ACRYLIC FIBER BY SOLUTION AND SUSPENSION POLYMERIZATION1
Polymerization
Process
Option
Control
Methods
AN Emission
Reduction
Estimated Costs (I960)1
Capital Annualized
($1000)
($1000/yr)
Comment
en
Solution
Polymerization
Suspension
Polymerization
Steam Stripping
95
Enclosure of spinning/ 98
washing section - vent
to incinerator
Slurry stripping
95
3300
2700
3300
a) High conversion
technology
(2 reactors)
b) Additional wash
step
79
3200
640 Does not affect VOC
emissions; could
affect product properties
870 Reduces VOC emissions
85%
620 Lower costs with good
emission control;
requires evaluation of
effects of fiber
properties
720 95% AN conversion not
always possible
aBased on 45,500 Mg/yr capacity, 8,000 operating hrs/yr model plants developed by Pullman Kellogg (Click and Moore, 1979).
Pullman Kellogg order-of-magnitude cost estimates updated to real (constant) November 1980 dollars using the Chemical
Engineering Plant Cost Index. Assumed capital recovery factor of 0.147 (12 yrs, 10% interest, real dollars) and
other capital (taxes, insurance, etc.) factor of 0.04 used by Hydroscience (Hobbs and Key, 1978) in their study on
acrylonH.rile monomer production. Cost estimates have not been thoroughly evaluated in light of current state-of-
the-art and economics.
-------
product quality and to achieve an economical residual AN removal. The
efficiencies of removing residual AN from the polymer range from 80 percent
to over 95 percent in practice. It should be noted, however, that recovery
credits for AN will increase with the price of AN monomer. Spinning emissions
could also be incinerated (though it would be difficult) in addition to
being enclosed and vented.
Floating roof controls appear to be effective in reducing emissions
from storage tanks. Fugitive emissions could be effectively in the plant
using the same procedures discussed for monomer operations.
5.2.3 ABS/SAN
Three different processes can be used to produce ABS plastics: emulsion
polymerization, suspension polymerization, and continuous mass polymeriza-
tion. SAN resin is generally produced by the emulsion process. In the
emulsion process, AN emission points are the graft reactor latex treatment
vessels, absorbers, and polymer dryers. Suspension process emission sources
are the prepolymerizer, the dewatering system, and the dryer. Emission
points in the continuous mass process are the bulk polymerizer, the monomer
vapor condenser, and the devolatilizer. Fugitive emission sources include
pumps, valves, and drains. AN monomer storage tanks are the largest AN
emission sources.
Manufacturers using the emulsion process have taken two basic approaches
to control acrylonitrile emissions: high monomer conversion technology
(HMCT) and vent incineration. The high conversion approach is an emission
control method with economic benefits. Monomer is highly polymerized,
leaving less residual AN monomer in the polymer slurry and lowering emissions
from later processing steps. High monomer conversion is achieved using a
second reactor the same size as the first reactor. The products of the
first reactor are transferred to the second-stage reactor where they are
allowed to react further, increasing the monomer conversion to around
98 percent.
The HMCT is estimated to have 80 percent emission reduction efficiency.
It requires for effective AN emission reduction that the second reactor and
5-18
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an absorber be installed at the polymer filter step. Emulsion polymeriza-
tion processes normally have another absorber following the graft reactors
as a part of the process. In order to achieve high conversion without
affecting product quality, it may also be necessary to switch catalysts.
Catalyst switching has been used by at least one manufacturer.
The second method, vent incineration, is applicable to all types of
processes. Basically, in this approach all emission vents are tied into
one or more incinerators. These incinerators may be parts of steam genera-
tors or other existing equipment in the plant. Although the venting of all
AN emission lines to an incinerator does not involve changes which affect
the product, it can be a very complex undertaking. This is because of the
many ducts which must be installed to carry all vent gases containing AN to
the incinerators.
Among the alternative control techniques, high conversion can be used
in combination with the incineration of dryer emissions in the emulsion and
the suspension processes. Due to the large volume of air exiting the
dryer, it is not possible to incinerate all the emissions from the dryer.
A possible solution is to recycle the dryer vent and incinerate only a
small slipstream. This procedure, combined with high conversion, can lead
to an AN emissions reduction of greater than 85 percent.
Emission sources in the SAN emulsion polymerization processes are the
graft reactors, the latex treatment vessels, and polymer dryers. The
vapors from the reactor and latex storage vents are sent to an AN absorber
where AN is recovered by countercurrently flowing demineralized water.
Vapors from the latex treatment vessels which also contain a small amount
of AN may be vented to an incinerator or the atmosphere. The latex
from the SAN reactor is steam stripped and the overhead vapors (containing
some AN) are condensed, decanted, and directed to the AN absorber for
further AN recovery.
In addition to having AN absorbers, many manufacturers achieve some
relatively high monomer conversion in the SAN reactors, thus reducing re-
sidual AN monomer. High conversion reduces AN emissions by 80 percent.
However, if further emission reduction is desired, the only commonly
applicable method is incineration of all vent streams containing AN.
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The incineration of vent streams, as in the ABS processes, would be
done by connecting all the streams to one or more incinerators. They may
be part of existing steam generators or other incinerating devices. Although
complex and extensive ductwork is involved, careful planning can optimize
costs and overcome safety problems.
A comprehensive vent incineration system, when applied together with
high conversion, is a very effective control technology for the reduction
of AN emissions. Vent incineration is applicable to all processes whereas
high conversion, although theoretically applicable, could require changes
in catalysts, etc. Thus, where possible, vent incineration applied in
combination with high conversion appears to give the greatest AN emission
reduction. Table 5-9 lists AN emission points and control methods at
existing ABS/SAN plants.
5.2.4 NBR Elastomers
Typical emission sources from a nitrile elastomer manufacturing plant
are reactors, the absorbing and stripping columns, and the finishing section
equipment. The fugitive emission sources are the storage tanks and the
process equipment such as pumps, valves, flanges, and drains.
In the manufacture of nitrile elastomers, high conversion technology
is not applicable since the desired end product properties can be obtained
only with a specific percentage of monomer polymerization. Any variation
in the monomer conversion will alter the properties of the product.
An effective and economically beneficial method of AN reduction is to
steam strip the latex. The latex formed in the polymerization reactor is
first flashed to remove residual butadiene and some AN and then steam
stripped. The stripper tops containing AN are sent to condensers for AN
recovery. The downstream AN emissions are reduced and unreacted AN is
recovered. Steam stripping efficiency is estimated to be greater than
90 percent.
Among the alternative control techniques are incineration of reactor
gases released at the flashing step. The latex is flashed in the post-
reactor section and then pumped to the blend tank. Semi-tight enclosures
could be used for all the tanks to collect vent gases and these gases could
be combined with dryer exhaust and sent to the incinerator. Alternatively,
flashing of the latex may be omitted and vent gases from all operations may
be combined and sent to the incinerator.
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TABLE 5-9. AN EMISSION POINTS AND CONTROLS AT EXISTING ABS/SAN RESIN OPERATIONS
Platit and location
Plant
AN Emission points
Emission
Controls
B.F. Goodrich
Louisville, Kentucky
Borg-Warner Chemicals
Washington, West Virginia
Borg-Warner Chemicals
Ottawa, Illinois
Dow Chemical Company
Torrance, California
Midland, Michigan
Pevley, Missouri
Allyns Point, Connecticut
Monsanto Plastic and Resin Co.
Addyston, Ohio
Monsanto Plastics and Resin Co,
Muscatine, Iowa
Monsanto Plastics and Resin Co.
Springfield, Massachusetts
USS Chemicals
Scotts Bluff, Louisiana
Blend tanks
Slurry and reslurry tanks
Wet screener and rotary filter
Dryers
Absorption column vent
Coagulation
Filtration
Drying
Storage
Absorber
Dewatering system
Latex
Drying and scrubbing
Not available
Not available
Not available
Not available
Polymerization Processes
Polymerization Processes
Reactors
Storage tanks
Coagulation system
Filtration system
Centrifuge
Drying and scrubbing
Baghouse
Polymerization/Material recovery
Compounding area
Fugitives
Storage
Not available
Incineration of dryer
exhaust in boiler;
98 percent efficiency
High conversion
technology with
absorption column
High conversion
technology
Not available
Vent incinerator at
95 percent efficiency
Not known
Scrubber in post-
compounding section
Source: Industry Supplied data
5-21
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The highest AN emission reductions for NBR plants appears to be achieved
by latex stripping with steam, followed by AN recovery and incineration of
vented gases in the finishing sections. The latex from the reactors is
steam stripped. The stripper overhead, containing the unreacted AN, is
sent to a water condenser followed by a chilled ammonia condenser for AN
recovery. Some AN may remain in the latex and emissions from the finishing
process may need to be controlled. This may be done by routing all the AN
vent streams containing AN to an incinerator. Emission points and control
methods at NBR operations are listed in Table 5-10.
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TABLE 5-10. AN EMISSION POINTS AND CONTROLS AT EXISTING NBR OPERATIONS
Plant and location
Plant
AN Emission points
Emission
Control s
Copolymer Rubber and Chemical
Corp.
Baton Rouge, Louisiana
B.F. Goodrich
Akron, Ohio
B.F. Goodrich
Louisville, Kentucky
Goodyear
Akron, Ohio
Goodyear
Houston, Texas
Uniroyal Chemical
Painesville, Ohio
Reichold
Cheswold, Delaware
Storage and transfer
From drains
Butadiene recovery
Absorber overhead purge
Coagulation tanks vent fan
Dryer exhaust fan
Product losses
Elastomer process
Controlled vents
Uncontrolled vents
Latex process
Not available
Not available
Not available
Storage
AN recovery
Weigh tank
Recovered AN accumulator
Vacuum jets
Latex storage
Finishing
Air dryer
Miscellaneous
Not available
Inert blanket and
pressure vent
Latex stripping
Incinerator/boiler with
90 percent efficiency
Not known
Stripper columns recove
89 percent efficiency
Source: Industry Supplied data
5-23
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REFERENCES FOR CHAPTER 5
1. Guideline Series: Control of Volatile Organic Fugitive Emissions from
Synthetic Organic Chemical, Polymer, and Resin Manufacturing Equipment.
Preliminary draft. U.S. EPA:OAQPS. January 1981.
2. Guideline Series: Control of Volatile Organic Emissions from Volatile
Organic Liquid Storage in Floating and Fixed Roof Tanks. Preliminary
draft. U.S. EPA:OAQPS. January 1981.
3. Summary of Group I Control Technique Guideline Documents for Control
of Volatile Organic Emissions from Existing Stationary Sources.
EPA-450/3-78-120. December 1978. pp. 2.21-2.22.
4. Reference 3. pp. 2.23-2.24.
5. Hobbs, F.D. and J.A. Key. Hydroscience, Inc. Emissions Control Options
for the Synthetic Organic Chemicals Manufacturing Industry. Arcylonitrile
Product Report. EPA Contract No. 68-02-2577. August 1978. P. V-6.
6. Anguin, M.T. and S. Anderson. Accurex Corp. Acrylonitrile Plant Air
Pollution Control. EPA Contract No. 68-03-2567. February 1979. p. 1-2.
7. Reference 6. pp. 19, 21.
8. Hughes, T.W. and D.A. Horn. Monsanto Research Corporation. Source
Assessment: Acrylonitrile Manufacture (Air Emissions). EPA Contract
No. 68-02-1874. September 1977. p. 38.
9. Reference 8. pp. 3-21.
10. Mjitre Corporation. Acrylonitrile Manufacture: Pollutant Prediction and
Abatement. EPA Contract No. MTR-7752. pp. 62-65.
11. Click, C.N. and D.O. Moore. Emission, Process and Control Technology
Study of the ABS/SAN, Scrylic Fiber, and NBR Industries. Pullman
Kellogg. Houston, Texas. Final Report for EPA Contract No. 68-02-
2619, Task No. 6. April 1979. pp. 151-193.
12. Reference 11. pp. 87-112.
5-24
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6. EMISSION DATA
6.1 AVAILABILITY OF DATA
The AN emissions data used in this report has been gathered from the
CMA, individual plants (Section 114 requests plant visit questionnaires),
permit files (Regional EPA offices and State offices), and previous EPA
studies (SRI, Hydroscience, and Pullman Kellogg). These data were developed
by using limited emissions testing and engineering calculations. The
available point source emission test data were gathered by in-house testing
teams using a variety of sampling methods. Test methods differed even
within the same company; one plant used a grab sample with gas chromato-
graphic (GC) analysis while another sampled vapors by carbon absorption and
elution to the GC. The collected data on storage tank and fugitive emissions
were obtained using emission factors in AP-42 and emission factors published
by the American Petroleum Institute.
6.2 SAMPLE COLLECTION AND ANALYSIS
The EPA does not have a reference sampling and analysis method for
measuring AN emissions from point sources. The EPA RM 25 is used to measure
total gaeous non-methane organic compounds from petrochemical operations.
It extracts a gaseous grab sample into a clean, evacuated stainless steel
dry ice trap. The trap condenses organic vapors. This trap is backed up
by an evacuated stainless steel flask to hold non-condensible gases. These
samples are returned to the laboratory where tKey are heated for combustion
of vapors (the flasks contain sufficient oxygen at known pressure for
pyrolysis) to carbon dioxide. A special GC measures total organic vapor
content. The RM 25 method can also use a gas chromatograph that samples
gases continuously from the source and performs oxidations in the instrument
for total organics analysis.
6-1
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The analysis of AN emissions from point sources could be accomplished
using a modified RM 25. The grab sample technique would probably be the
most applicable since the GC needed to do qualitative and quantitative
analysis of mixed component systems may not be readily transported (this is
not always the case). The stainless steel traps or glass flasks may be
used for the grab sample. Eluting the sample into a GC prepared to separate
and analyze individual gas components can be accomplished by heating the
flasks below the combustion temperature of the gases. Total mass emission
rate can be calculated using measured effluent flow parameters (volumetric
flow rate, temperature, and pressure) and the concentration of AN in the
grab sample.
6-2
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7. STATE AND LOCAL REGULATIONS
This chapter discusses State and local regulations pertaining to VOC
emissions and their applicability to AN emission sources. Federal regula-
tions that could affect AN emission sources also are examined.
There are no States which currently have specific regulations limiting
AN emissions to the atmosphere; therefore, AN emissions from all four
industry segments (ABS/SAN, fibers, NBR, and monomer) are regulated under
State VOC standards. Facilities manufacturing or using AN are located in
18 States, 9 of which regulate AN emission sources by applying the general
provisions of their VOC regulations for process, storage, and loading VOC
emissions. The States regulating all three types of emissions are Texas,
Ohio, Tennessee, Louisiana, Illinois, California, Connecticut, Michigan,
and Kentucky. Nine States have no VOC process, storage, or loading regulations.
These are South Carolina, Florida, Mississippi
(Borg-Warner is building a bulk process ABS/SAN plant in Bienville, Mississippi),
Delaware, Virginia, Iowa, West Virginia, Missouri and Massachusetts. The
only State that has just VOC storage and loading regulations is Alabama.
The majority of the States which have process regulations require
85 percent reduction of process VOC emissions. The States requiring a per-
centage reduction also may require specific control techniques. Recommended
techniques include vent gas incineration, adsorption, vapor recovery systems,
or any other control system which has been approved by the State for use
and meets emission reduction requirements. Incineration is the most common
VOC emission control technique required by the State regulations.
Ohio, which has the highest number of AN emission sources, requires
this 85 percent VOC emission reduction to be achieved if process VOC source
discharges to the atmosphere are greater than 18 Kg/day (40 Ibs/day) or
3.6 Kg/hr (8 Ibs/hr). Under Ohio regulations, emission reductions can be
7-1
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achieved through any of the above-mentioned controls except vapor recovery
systems. Ohio's regulations apply only to those areas classified as Priority I,
while other areas of the State have no VOC regulations. Connecticut and
Illinois set percentage reduction levels the same as those in Ohio. VOC
emission sources in these States which have higher VOC emissions than
18 Kg/day, must apply control techniques to achieve 85 percent emission
reduction.
Some States do not require a percentage reduction; they only require
the sources to apply emission control devices. In the cases of Texas,
which has the second highest number of facilities per State, and Louisiana,
VOC emission reduction is required by burning the VOC vent gas streams in a
smokeless flare or a direct flame incinerator or by applying any other
approved emission control device. Texas requires VOC emission controls in
both ozone attainment and nonattainment areas.
VOC emission sources located in Michigan and Tennessee are required to
meet the lowest achievable emission rate (LAER). Requiring the emission
source to meet LAER instead of applying a specific emission control device
does not preclude the use of any effective control devices an industry may
want to employ. The industry must demonstrate to the State during the
permitting process that the control technique will meet LAER.
Ten States have regulations for storage tank VOC emissions covering
both large and small storage tanks. Large tanks range in size from 95 M
to over 246 M with the average size being about 150 M . Generally, States
require large storage tanks to have controls such as double seal floating
roofs or vapor recovery systems unless these tanks are pressure tanks
capable of maintaining a working pressure sufficient to prevent vapor loss.
3 3
Small tanks range in size from 1 M to just under 150 M . There are two ,
types of small tanks. Those averaging from 1 to over 3.8 M are usually
required to use submerged fill pipes to prevent excessive vapor emissions;
however, they may be equipped with other control devices. Tanks up to
3
150 M in size are required to have floating roofs or vapor recovery systems
if they are not pressure tanks. The control method used for both large and
small tanks is dependent upon the vapor pressure of the VOC being stored.
Ten States have regulations for loading or unloading VOC fron any
loading facility. The control equipment required depends on the throughput
level of a loading system. This level ranges from 39,000 to over 150,000
7-2
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liters. The average capacity of the vehicle or tanks being loaded is
852 liters. The most commonly used control technique is a vapor collection
and disposal system consisting of an adsorber or condensation system which
recovers 90 percent of the emissions. This system is equipped with a
loading arm with pneumatic, hydraulic, or other mechanical means which
provides a vapor tight seal between the adapter and the tank or vehicle
hatch. Other controls which are used at loading facilities are a submerged
fill pipe or an equally efficient approved control device. Drainage into
the vehicle or tank also must be provided before the removal of the arm so
as to prevent spills during attachment and removal of the loading arm.
Connecticut is the only State that has established an odor threshold
limit for AN. The regulation states a facility cannot emit a substance
with an objectionable odor beyond its property line. The odor threshold
limit for AN is 21.4 ppm.
Along with the State regulations there are local regulations that
could be applicable to AN emissions. Kentucky and Tennessee have local
regulations for VOC emissions. However, Memphis, Tennesse, VOC regulations
do not apply to AN emission sources since the regulations only regulate
specific sources, such as coating industries. Jefferson County, Kentucky,
regulates process, storage, and loading emissions. The chemical reaction
process regulations apply to both of the AN sources in the State and require
84 percent reduction or a vapor recovery system which recovers 90 percent.
Storage tanks in Jefferson County under 1000 liters are not regulated.
Tanks ranging from 1000 to 150,000 liters are required to be equipped with
a submerged filler pipe, floating roof, or equivalent control equipment.
Those storage vessels which are pressurized are exempt from the standard.
Loading facilities are required to install vapor recovery systems.
In addition to State and local regulations, OSHA has established
Federal regulations which are applicable to AN emission sources. OSHA
limits worker exposure to AN by establishing a workplace standard of 2 ppm
averaged over 8 hours or 10 ppm averaged over any 15-minute period during
the working day. This standard went into effect in November 1978 and
allowed industry two years to install the required engineering controls to
limit exposure. OSHA is only concerned with worker exposure to AN emissions
which could affect employee safety and health; the regulations do not
7-3
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specifically limit AN emissions to the atmosphere. One engineering work
practice which can be used to comply with the OSHA standard to ensure
employee safety is to vent the airborne AN to a location where employees
will not be exposed. These fugitive AN emissions then may become an atmos-
pheric emission problem.
The EPA is presently developing air pollution regulations and guidelines
for SOCMI which could have an impact on atmospheric AN emission levels.
Process VOC emissions from new or modified AN monomer plants will be regulated
by the air oxidation unit process NSPS currently being developed. The
proposed fugitive VOC emission standard for SOCMI would apply to'fugitive
emissions from new AN monomer facilities. The SOCMI regulation being
developed for VOL storage would regulate tanks with a capacity greater than
150,000 liters and a vapor pressure greater than 1.5 psia and would apply
to new storage tanks in all four segments of the AN industry. The AN
monomer capacity increases planned by Vistron at Green Lake, Texas, and by
Monsanto at Texas City, Texas, would not be regulated by either the process,
fugitive, or storage NSPS. The new ABS/SAN resin facility being constructed
by Borg-Warner at Bienville, Mississippi, would not be regulated by the
storage NSPS. These plants are not regulated because construction permits
have been issued to these plants prior to NSPS promulgation.
There are also CTGs being developed by EPA for process, fugitive, and
storage emissions from SOCMI and are applicable to existing sources in
nonattainment areas requesting a SIP extension. The CTGs are designed to
assist the States in developing regulations for these emissions. Since a
majority of the AN facilities are in nonattainment areas, these facilities
could be affected by the guidelines if they are adopted by the States.
Table 7-1 lists the attainment status for each facility. At this time the
CTGs would only apply to AN monomer operations; a NESHAP regulation
developed for the AN industry would cover all industry segments.
7-4
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TABLE 7-1. ATTAINMENT STATUS
Producer Location
(city, county, state)
AN Monomer Facilities:
American Cyanamid
DuPont
Dupont
Monsanto
Mosanto
Sohio (Vistron)
Sohio (Vistron)*
ABS/SAN Facilities:
Abtec (Mobay)
Borg-Warner
Borg-Warner
Dow
Dow
Dow
Dow
Monsanto
Monsanto
Monsanto
West Uego, Jefferson, LA
Beaumont, Hardin, TX
Memphis, Shelby, TN
Alvin, Brazoria, TX
Texas City, Galveston, TX
Lima, Allen, OH
Victoria, Victoria, TX
Louisville, Jefferson, KY
Washington, Wood, WV
Ottawa, LaSalle, IL
Torrance, Los Angeles, CA
Midland, Midland, MI
Pevley, Jefferson, MO
AHyns Point, New London, CT
Addyston, Hamilton, OH
Muscatine, Muscatine, IA
Springfield, Hampden, MA
USS Chemical .Scotts Bluff, East Baton
Rouge, LA
Acrylic Fiber Facilities
American Cyanamid
Badische
DuPont
DuPont
Tennessee Eastman
Monsanto
:
Milton, Santa Rosa, FL
wniiamsburg, Surry, VA
Camden, Kershaw, SC
Waynes boro, Augusta, VA
Kingsport, Sullivan, TN
Decatur, Morgan, AL
Attainment status
Ozone
Nonattainment
Attainment
Nonattainment
Nonattainment
Nonattainment
Nonattainment
Nonattainment
Nonattainment
Attainment
Nonattainment
Nonattainment
Nonattainment
Attainment
Nonattainment
Nonattainment
Attainment
Nonattainment
Nonattainment
Attainment
Attainment
Attainment
Attainment
Nonattainment
Nonattainment
Extension
Requested
Yes
Yes
Yes
Yes
Yes
Nitrile Elastomer Facilities:
Copolymer Rubber
Goodrich
Goodrich
Goodyear
Goodyear
Re i chol d
Uni royal
Baton Rouge, East Baton
Rouge, LA
Akron, Summit, OH
Louisville, Jefferson, KY
Akron, Summit, OH
Houston, Harris, TX
Cheswold, Kent, OE
Painesville, Lake, OH
Nonattainment
Nonattainnent
Nonattainment
Nonattainment
Nonattainment
Attainment
Nonattainment
Yes
Yes
Yes
•Scheduled to be on line in 1981
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