EPA-600/2-77-023d
February 1977
Environmental Protection Technology Series
INDUSTRIAL PROCESS PROFILES FOR
ENVIRONMENTAL USE: Chapter 4.
Carbon Black Industry
Industrial Environmental Research Laboratory
Office of Research and Development
U.S. Environmental Protection Agency
Cincinnati, Ohio 45268
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RESEARCH REPORTING SERIES
Research reports of the Office of Research and Development, U.S. Environmental
Protection Agency, have been grouped into five series. These five broad
categories were established to facilitate further development and application of
environmental technology. Elimination of traditional grouping was consciously
planned to foster technology transfer and a maximum interface in related fields.
The five series are:
1. Environmental Health Effects Research
2. Environmental Protection Technology
3. Ecological Research
4. Environmental Monitoring
5. Socioeconomic Environmental Studies
This report has been assigned to the ENVIRONMENTAL PROTECTION
TECHNOLOGY series. This series describes research performed to develop and
demonstrate instrumentation, equipment, and methodology to repair or prevent
environmental degradation from point and non-point sources of pollution. This
work provides the new or improved technology required for the control and
treatment of pollution sources to meet environmental quality standards.
This document is available to the public through the National Technical Informa-
tion Service, Springfield, Virginia 22161.
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EPA-600/2-77-023d
February 1977
INDUSTRIAL PROCESS PROFILES
FOR ENVIRONMENTAL USE
CHAPTER 4
CARBON BLACK INDUSTRY
by
Richard W. Gerstle and John R. Richards
PEDCo-Environmental Specialists, Inc.
Cincinnati, Ohio 45246
Terry B. Parsons and Charles E. Hudak
Radian Corporation
Austin, Texas 78766
Contract No. 68-02-1319
Project Officer
Alfred B. Craig
Metals and Inorganic Chemicals Branch
Industrial Environmental Research Laboratory
Cincinnati, Ohio 45268
INDUSTRIAL ENVIRONMENTAL RESEARCH LABORATORY
OFFICE OF RESEARCH AND DEVELOPMENT
U.S. ENVIRONMENTAL PROTECTION AGENCY
CINCINNATI, OHIO 45268
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DISCLAIMER
This report has been reviewed by the Industrial Environmental Research
Laboratory - Cincinnati, U.S. Environmental Protection Agency, and approved
for publication. Approval does not signify that the contents necessarily
reflect the views and policies of the U.S. Environmental Protection Agency,
nor does mention of trade names or commercial products constitute endorsement
or recommendation for use.
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TABLE OF CONTENTS
CHAPTER 4
Page
INDUSTRY DESCRIPTION 1
Raw Materials 3
Products 3
Companies 4
Environmental Impact 4
Bibliography 8
INDUSTRY ANALYSIS 10
Furnace Process 12
Process No. 1. Cracking, Quenching and Filtration 14
Process No. 2. Product Modification and Drying 18
Process No. 3. Off-Gas Combustion 20
Thermal Process 23
Process No. 4. Cracking and Filtration 25
APPENDIX A - Furnace Black Feed Characteristics 27
APPENDIX B - Company Listing 29
APPENDIX C - Atmospheric Emissions 33
m
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LIST OF FIGURES
CHAPTER 4
Figure Page
1 Furnance Process Flowsheet 13
2 Thermal Process Flowsheet 24
iv
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LIST OF TABLES
CHAPTER 4
Table No. Page
1 Carbon Black Producers 4
2 Example Operating Conditions for a Reaction 15
A-l Typical Feed Oil Characteristics 28
A-2 Typical Natural Gas Composition 28
B-l Carbon Black Plants - 1974 30
C-l Typical Atmosphere Emissions for a 90 Million Pound Per
Year Carbon Black Plant 34
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ACKNOWLEDGMENT
This report was prepared for the Control Systems Laboratory by
PEDCo-Environmental Specialists, Inc. under Contract No. 68-02-1321,
Task 21. Richard Gerstle and John Richards were the co-authors of
this report. Dr. I. Jefcoat was the EPA Project Officer. Mr. Paul
Spaite, Consultant, assisted in project coordination and provided
helpful assistance.
vi
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CARBON BLACK INDUSTRY
INDUSTRY DESCRIPTION
The carbon black industry is a distinctive portion of the chemical
industry, which processes hydrocarbon feedstocks (mainly heavy oils)
into finely divided carbon black particles for use largely in tires, and
to a lesser extent, pigments, cement and cosmetics. The industry's sole
products are various grades of carbon black. It is classified by the
Department of Commerce under Standard Industrial Classification Code
(SIC) 2895. Many of the companies involved in producing carbon black
also produce other products, but these other products are independent of
the carbon black process and are not related to this industry.
There are three ways of making carbon black, namely:
Furnace process
Thermal process
Channel process
The furnace process currently accounts for about 90 percent of
production, with the thermal process accounting for most of the remaining
1 2
10 percent. ' The dominance of the furnace process is primarily due to
the inherent flexibility to economically produce a wide variety of car-
2 3
bon black products. ' Products of the furnace and thermal processes
have important physical differences (primary particle size) which affect
the markets available. Generally these products do not compete for the
same specific applications, therefore, the thermal and furnace plants
are complimentary not alternative processes.
There is presently only one channel black plant in operation and
it is subject to a court order requiring gradual closure during the
next five years. This plant accounts for only 0.1 percent of domestic
carbon black production. Channel process plants have been replaced
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with furnace process plants which can produce most of the same products
without the major environmental problems associated with the older
channel process.
Carbon black is currently manufactured at 33 locations in the
United States. (One additional plant is currently not in operation.)
These plants are mainly located in rural areas with only a few plants
located near large population centers. Plants range in capacity from
approximately 22.7 to 173 x 106 kg/year (25,000 to 190,000 tons).
Capacity is, however, difficult to quantify since it is highly dependent
on product characteristics, feedstock quality, and various operational
factors. Total annual sales amounted to 1.4 x 10 kg (1,550,000 tons)
in 1974, which is approximately 70 percent of industry capacity. This
4
is somewhat below the average capacity factor of 80 percent. Near term
industry growth will be accomplished primarily through plant modifica-
4
'4
4
tions. No new carbon black plants are anticipated in the next several
years.
The domestic carbon black industry is not threatened by foreign
imports. Furthermore, there is no generally acceptable substitute
for carbon black in major applications such as automobile tires and
colorants. For these reasons, steady growth of the domestic industry
is expected. The growth rate predictions, however, are uncertain since
this industry is closely tied to the automobile industry. A significant
change in automobile sales or a increased demand for small cars would
4
have a potentially large influence on carbon black demand.
Approximately 94 percent of domestic production in 1974 were used in
the automobile industry. A 3 percent carbon black industry rate is pre-
dicted for the next four years.
Total employment in the carbon black industry is too small to be
tabulated on a routine basis, but it is probably on the order of 1000
to 1500 plant personnel.
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Raw Materials
Furnace process plants utilize oil as the main feedstock for pro-
duction of carbon black and use varying quantities of natural gas for
heat and process control. The most desirable feedstocks are high
aromatic oils with low sulfur content. In the thermal process,
natural gas is the only raw material.
Liquid feedstocks are transported by rail, barge, and tank truck.
The environmental impact connected with feedstock production occurs at
the petroleum refinery. Transportation of the feedstocks does not
entail any impact other than those associated with internal engine fuel
combustion. Oil spills from oil transfer operations and storage facil-
ities can occur accidentally. There are no fugitive emissions.
Natural gas is conveyed by pipeline, and does not cause any unusual
environmental impact during its transportation. Example feedstock
compositions are provided in Appendix A.
Products
Carbon black products have a high degree of diversity with respect
to physical properties and applications. The main property affecting
the characteristics is the particle size of the carbon particles. Mean
o , 2
particle size varies from 100 to 4000 A in diameter. Due to the
effect on rubber characteristics ; carbon black particle products are
sometimes described as "soft" or "hard". The degree of particle agglo-
meration ("structure") is a second physical characteristic of importance.
All carbon black products are essentially pure carbon with trace amounts
of sulfur and some organic compounds.
The physical properties now serve as the basis for an ASTM product
classification system developed in 1968. This is a four digit alpha-
numeric code representing particle size and curing rate. This system
replaces a more cumbersome code which was more closely related to the
influence of the carbon black on rubber characteristics.
aOne angstron is equivalent to 1 * 108 centimeters.
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Companies
Eight companies produce carbon black in the United States as shown
in Table 1. This table also shows the percent of total industry capacity
by company. A number of these companies are closely associated with
petroleum companies since the required feedstock is derived from petroleum
refining.
A complete list of plants, their locations and capacities is included
in Appendix B.
Table 1. CARBON BLACK PRODUCERS
Company
% of furnace
black capacity
% of thermal
black capacity
Ashland Chemical Company
Division of Ashland Oil Co., Inc.
Cabot Corporation
Cities Service Company, Inc.
Columbian Division
Commercial Solvents Corporation
Thermatomic Carbon Co. Division
Continental Carbon Company
J. M. Huber Corporation
Phillips Petroleum Company
Sid Richardson Carbon Company
16.0
23.9
21.2
11.3
10.0
12.4
5.2
28.7a
15.8
43.0
12.5
presently shutdown.
Environmental Impact
o Furnace Process - Gaseous emissions of carbon monoxide and hydrogen
sulfide constitute the primary environmental problems associated with
furnace process plants. Other atmospheric emissions include small quan-
tities of particulate and hydrocarbons (primarily acetylene).
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The concentrations and quantities of CO emitted are intimately
related to the type of carbon black product. Generally the quantity
of CO evolved during the cracking process is inversely proportional to
the particle size of the final product. Emissions range between 0.8
4
to 3.0 kg per kg of black for typical products. Despite the much
higher CO emissions from fine particle black process lines, the stack
concentration is generally lower than larger particle black lines
due to the greater burden of water vapor and other inert gases. The
o
off-gas concentration can vary from 3 to 7 percent, 78,000 to 18,200 mg/m
(30,000-70,000 ppm), with the lower values corresponding to fine particle
black process lines. This dilution factor, necessary for the production
of small particle blacks, reduces the heat content of the off-gas thereby
complicating pollution control. Meteorological dispersion modeling
of a hypothetical carbon black plant (125,000 ton per year capacity)
suggest that National Air Quality Standards for CO will probably be
A
violated in the vicinity of the plants. Due to the high CO levels
in the plant off-gas; stack sampling personnel should have special
training before attempting any tests.
The hydrogen sulfide emissions are closely related to the sulfur
content of the feedstock. The prevailing trend is toward higher sulfur
content feedstocks due primarily to the shortage of more desirable
oil supplies. It is anticipated that the sulfur content will gradually
increase from the present 1 to 2 percent by weight levels to a 2 to
3 percept by weight range in. the near future.^ This could substantially
increase present H,S emissions, estimated at 0.03 kg per kg of black and
"? 4
130 to 2600 mg/m (50 to 1000 ppm)(v/v). Other sulfur compounds emitted
may include carbon disulfide (CSg) and carbonyl sulfide. Hydrogen sul-
fide odors are apparent in the vicinity of some carbon black plants.
Particulate emissions are generally highly controlled due to both
economic considerations and environmental control requirements. Ef-
fluent from the fabric filters contain particulate concentrations in
the range of 0.068 to 0.295 g/DNm3 (0.03 to 0.13 grains/dscf) and
represent approximately 0.001 to 0.005 kg per kg of black. Despite
these low emission rates, some concern has been expressed due to the
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potentially carcinogenic character of emissions from cracking processes.
A number of toxicological and analytical studies " have been done,
however, no clear results are apparent. The analytical studies have
demonstrated the presence of between 7 and 20 known carcinogens however,
there is a serious question whether these compounds can be released
to body fluids. Due to the large surface area of carbon blacks it is
conceivable that the carcinogenic action is precluded by strong adsorp-
tion of the compounds on the surface of the carbon black particles.
Investigations have generally been unsuccessful both in identifying
the PAH compounds in fluids exposed to carbon black and in inducing
cancer development in animals. Additional study is necessary to
clarify the potential carcinogenic characteristics of various grades
of carbon black. The industry deserves considerable credit for
sponsoring early work in this subject area well before there was
national interest in environmental control.
Hydrocarbons comprised mainly of methane and acetylene ore
emitted at a rate of 0.03 to 0.26 kg per kg of black. Off-gas concen-
trations are 0.15 to 0.85 percent, 3900 to 27,100 mg/m (1500-8500 ppm).
These two hydrocarbons should not contribute significantly to photochemical
oxidants in the general vicinity of the plant since both are much less
reactive than most hydrocarbons. The impact of such emissions, how-
ever, during long range transport is less certain since even very slow
photochemical reactions could be of significance.
Only a few furnace process plants presently utilize off-gas com-
bustion in order to reduce emission of CO, H^S and other pollutants.
Previously, control applications have been limited to installations
where there is a local market for the excess steam energy which can
be generated in a CO boiler, There is now a trend toward use of more
off-gas as a supplemental fuel in pellet driers and toward the use of CO
boilers on new process lines equipped with the necessary mechanical
steam driers for use of the generated steam. This trend is due to
both environmental considerations and the rising cost of all forms
of energy. In most properly designed combustion devices (including
pellet driers and CO boilers) the control efficiencies for CO, H$
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and hydrocarbon approach 99 percent. Thermal incineration yields the
same control efficiencies without benefit of energy recovery. In all
three types of control devices, small quantities of S02 and NOX are
generated. S02 emissions can be increased from essentially zero to
0.02 kg per kg of black and to a concentration of 780 mg/m3 (300 ppm).
Nitrogen oxide emissions are estimated to increase from approximately
*2
26 mg/m3 (10 ppm), in the reactor, to 182 mg/m (70 ppm) leaving the con-
trol device (0.0002 to 0.003 kg per kg af black).
The furnace process operates without any major liquid process waste
since it is basically a gas phase process. Wet scrubbers occassionally
used to control atmospheric particulate emissions recover a useful pro-
duct, therefore, such effluent is genrally utilized either in the quench
system or the pelletizer so that the black will reenter the process stream.
Boiler blowdown is the only liquid waste commonly discarded.
There are no major solid waste associated with the furnace pro-
cess. Limited amounts of refractor material, scrap, and worn fabric
filter bags must be discarded in landfill. The quantities are insig-
nificant. There is growing interest over the long term in the use of
waste tires as a substitute feedstock at carbon black plants. This
could partially alleviate one of the major solid waste problems in
the United States.
o Thermal Process - Thermal process plants utilize a cleaner feed-
stock and can recycle all of the off-gas to reactors to recover the
heating value (due primarily to HL). Environmental control is an in-
herent part of the process, therefore, emissions are generally con-
sidered insignificant. Aqueous and solid waste quantities are also
very small.
Flares are also utilized, however, control efficiencies and exit pol-
lutant concentrations are not well known due to the difficulty in sampling.
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BIBLIOGRAPHY
1. Chemical Marketing Reporter, 205(10). March 11, 1974.
2. Schwartz, W. A., et al. Engineering and Cost Study of Air Pollution
for the Petrochemical Industry, Volume 1: Carbon Black Manufacture
by the Furnace Process. Environmental Protection Agency, Raleigh,
North Carolina. Publication No. EPA-450/3-73-006a. June 1974.
3. Mantell, C. L. Carbon and Graphite Handbook. Wiley and Sons, Inc.
1968.
4. An Investigation of the Best Systems of Emission Reduction for Fur-
nace Process Carbon Black Plants in the Carbon Black Industry.
Emission Standards and Engineering Division, Office of Air Quality
Planning and Standards, Environmental Protection Agency, April 1976.
5. Private Communication, Bureau of Labor Statistics, Dept. of Labor,
Chicago, Illinois, February 5, 1975.
6. Standard Recommended Practice for Nomenclature for Rubber Grade
Carbon Blacks. In: ASTM Standards for Rubber and Carbon Black
Products, Vol. 28, pp. 1047, 1968. American Society for Testing and
Materials, Designation D 2516-68.
7. Falk, H. L. and P. E. Steiner. The Identification of Aromatic
Polycyclic Hydrocarbons in Carbon Blacks. In: Cancer Research,
12:30-39, 1952.
8. Steiner, P. E. The Conditional Biological Activity of the Carcinogens
in Carbon Blacks, and Its Elimination. In: Cancer Research,
14:103-110, 1954.
9. Nau, C. A., Neal, J., Stembridge, V. A. and R. N. Cooley. Physio-
logical Effects of Carbon Black, IV, Inhalation. In: Archives
of Environmental Health, 415-431, April 1962.
10. Ingalls, T. H., and R. Risquez-Iribarren. Periodic Search for Cancer
in the Carbon Black Industry. In: Archives of Environmental Health,
2:429-433, April 1961.
11. Neal, J. and N. M. Trieff. Isolation of an Unknown Carcinogenic
Polycyclic Hydrocarbon from Carbon Blacks. In: Health Lab. Sci.,
9:32-38, January 1972.
12. Falk, H. L., Kotin, P. and I. Markul. The Disappearance of Carcin-
ogens from Soot in Human Lungs. In: Cancer, 11:482-489, 1958.
13. Ingalls, T. H. Incidence of Cancer in the Carbon Black Industry.
In: Archives of Industrial Hygiene and Occupational Medicine,
1:662-676, June 1950.
8
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14. Boren, H. G. Carbon as a Carrier Mechanism for Irritant Gases.
In: Archives of Environmental Health, 8:119-124, Jan. 1964.
15. Qazi, A. H. and C. A. Nau. Identification of Polycyclic Aromatic
Hydrocarbons in Semi-Reinforcing Furnace Carbon Black. Department
of Environmental Health, University of Oklahoma, Health Sciences
Center, Oklahoma City, Oklahoma, 18 p.
16. Falk, H. L. and P. E. Steiner. The Adsorption of 3,4-Benzpyrene
and Pyrene by Carbon Blacks. In: Cancer Research, 12:40-43,
1952.
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INDUSTRY ANALYSIS
The analysis of the carbon black industry is logically divided
into discussions of the furnace and thermal processes. Recognizing
that the furnace process accounts for 90 percent of domestic carbon
black production and a much greater share of the environmental impact,
aspects relative to the furnace process are emphasized.
Process flow sheets have been prepared for each of the major
processes. These are highly generalized and have been arranged to
highlight environmental impact. In certain cases a series of major
steps have been combined into blocks in order to yield one distinct
pollutant source. Despite the apparent simplicity of these flowsheets,
it should be appreciated that the industry is extremely diverse with
respect to equipment design, process operation and product character-
istics. Due to these differences it is extremely difficult to
characterize the capacity of a single process line of a plant overall.
Furthermore, each process has the capability to produce a variety
of carbon black products. Therefore, the information provided with
respect to utilities, impact materials, and operating conditions is
not necessarily applicable to any one process line
or plant.
Most of the information contained in the following section has
been obtained by PEDCo-Environmental Specialists, Inc. and Air Products,
Inc. (Houdry Division) during recent EPA Contract studies, The PEDCo
study served as the basis for an EPA Standard Support Document for the
Furnace Black industry. This report is the primary reference for this
industry analysis.
Trends in the carbon black industry will have a major influence on
the environmental impact and energy impact of this industry. The carbon
black industry is unique with respect to the close relationship between
10
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pollutant emissions and energy use since the primary pollutants have
a substantial heating value. The relationship, however, is highly
complex and deserves considerably more discussion than is possible
in a catalog summary. Under certain circumstances, the combustion
of off-gas pollutants can simultaneously reduce pollutant emissions
and reduce the demand for electrical energy in the plant. Conversely,
some plants with a low Btu content off-gas cannot burn the off-gas with-
out a substantial increase in supplemental fuel (mainly natural gas or
distillate oil). While secondary combustion always reduces environmental
impact, the resulting energy impact can range from moderately positive
to substantially unfavorable. Due to the dual importance of environ-
mental and energy problems, this aspect of carbon black production is
given emphasis.
11
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Furnace Process
The generalized flowsheet for the furnace process is shown in
Figure 1. Carbon black is produced by the cracking of oil feedstock
in a series of reactors. Some natural gas is used to heat the
vaporized oil to the necessary reactor temperature. Product charac-
teristics are controlled by a variety of proprietory operating
procedures which generally involve means to change residence time in
the cracking zone of the reactor. Primary quench can be done to
abruptly terminate quenching. Subsequent quench cooling to less than
500 F is necessary to protect downstream fabric filters for product
recovery. Both quench processes are included in the first block along
with the fabric filter. This block essentially comprises 80 percent
of most existing plants since only pelletizing and product storage
are not included.
It should be noted that the fabric filter is generally considered
an integral part of the carbon black plant since it serves as the only
means of product recovery from the reactor gas stream. Present fabric
filter, however, are probably over-designed from a purely economic
standpoint, since somewhat greater product losses could be tolerated.
Environmental regulations are responsible for the very high efficiency
necessary.
Product yield is generally defined as the quantities of carbon
black produced per unit quantity of carbon in the feedstock. A differ-
ent basis has been used for expressing emission quantities and other
factors in the subsequent process description. These factors are de-
scribed (unless otherwise stated) in terms of quantity per unit quan-
tity of product. The revised basis is considered more useful to persons
interested in environmental control who do not have routine access to
data concerning feedstock characteristics.
12
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PETROLEUM
BASE
OILS
WATER
AIR
1
1 I
CRACKING,
QUENCHING
AND FILTRATION
OFF-GAS —|
NATURAL GAS—i
MML
WATER-
PRODUCT
MODIFICATION
AND DRYING
WATER—|
NATURAL GAS—|
CARBON
BLACK
PRODUCT
P GASEOUS EMISSIONS
-^ LIQUID WASTE
Y SOLID WASTE
MAIN PROCESS STREAM
OFF-GAS STREAMS
UTILITY STREAMS
ii
OFF-GAS
COMBUSTION
STEAM
Figure 1. Furnace process flowsheet.
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CARBON BLACK (Furnace Process) PROCESS NO. 1
Cracking, Quenching and Filtration
1. Function - This process involves the incomplete combustion and
thermal cracking of a liquid hydrocarbon feedstock at a temperature
of approximately 1400°C to produce an aerosol of carbon particles. The
gaseous effluent from the reactor undergoes primary quenching with
water to reduce gas temperatures to approximately 540 C, thereby
stopping the cracking reactions. Secondary quenching is done to fur-
ther reduce temperature to less than 500 F in order to protect the
fabric filter. Condensation of corrosive gases occurs if the temper-
ature drops below 400-450 F. The particulate (raw carbon black) is
then removed from the gas stream by passage through a multi-compart-
ment fabric filter system. A number of reactors (2 to 10) are normally
manifolded together and served by a single quench chamber and product
123
collection system. '
2. Input Materials - The main input materials include an oil feed-
2 3
stock with natural gas for heat and product quality control. '
Highly aromatic oil is desired due to high product yields, and the
low endothermic heat requirements. Refinery by-product residuum
tars are commonly used as feeds. Sulfur contents in the range of
1 to 3 percent are encountered.
The consumption of feedstocks per unit of product varies with
the desired product characteristics. Reported yields are in the range
of 0.5 to 0.65 kilgram of product per kilogram of carbon in feed for the
larger sized blacks, and 0.2 to 0.3 for very small particle blacks.1'3
3. Operating Parameters - Operating conditions will vary from plant
to plant and within a given plant depending on the grade of product
manufactured. Details of reactor operation and exact feed rates are
proprietary, but generally speaking, the smaller the carbon black par-
ticle size being made, the higher the necessary air-to-oil ratio, and
the lower the yield of black (kg of product per kg of carbon in feedstocks)
While it is not possible to define "representative" reactor operating
14
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conditions, example reactor feed rates and temperatures are presented
in Table 2 for illustrative purposes.
Table 2. EXAMPLE OPERATING CONDITIONS FOR A REACTOR2
Parameter Value
Rate of feed oil 757 liter/hour
(200 gallons/hour)
Preheat temperature of oil 260 C
3
Rate of air supplied 1.8 m /sec
(235,000 cfh)
3
Rate of natural gas supplied 0.17 m /sec
(22,000 cfm)
Furnace temperature in reaction zone 1400 C
Rate of carbon black production 390 kg/hour
(860 Ibs/hour)
Yield of black (kg of product in 100 kg of C 60%
in feedstock
After the gases leave the reactor they are cooled, and enter a
multicompartment fabric filter containing tube type fiberglass bags.
Silicon-graphitized and Teflorr^ coat ings have been used to improve
filter performance. Bag life varies from 9 to 30 months. Filtering
velocities are low relative to some of the fabric filter applications
with air-to-cloth ratios varying from 1.0 to 1.7 cubic meters per
minute per square meter of fabric area. Maximum pressure drop is in
the range of 150 to 250 millimeters of water (6 to 10 inches). Cleaning
of compartments is normally done on a 2 to 10-minute cycle by reversing
the gas flow.
4. Utilities - Natural gas is considered as a feed stream and not a
utility. The following approximate utility rates are required:
Electricity 0.22 kWh/kg (200 kWh/ton of product)
Water 6 I/kg (1450 gallons/ton of product)
Registered trademark.
15
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5. Waste Streams - The major waste stream from this process is the
atmospheric emission of CO, gaseous hydrocarbons, participates, and
H^S. These emission levels are:
Pollutant quantity Pollutant concentration
in off-gas in off-gas
Pollutant (kg/kg of product) yg/nr
CO 0.8-3.0 3.4 x 107 to 8.0 x 10
Hydrocarbons 0.07-0.1 1.5 x io6 to 8.5 x 106
Hydrogen Sulfide 0.005-0.013 7.0 x IO4 to 1.0 x IO6
Particulate 0.001-0.003 not applicable
Sulfur Dioxide trace trace to 3.93 x 10
Nitrogen Oxide =0.0002 9.8 x IO5 to 1.2 x IO5
The carbon monoxide emissions vary according to the type of carbon
black product being produced. Very small particle blacks generally
result in high emission quantities and somewhat lower pollutant con-
centrations. Similar trends occur for hydrocarbons and to a limited
extent hydrogen sulfide. The apparent inconsistency is due to the
greater gas volumes in the fine particle balck process lines.
The hydrogen sulfide emissions are closely related to the feed-
stock sulfur content.
The particulate emission depend primarily on the particle charac-
teristics and the condition of the fabric filter. Particle size dis-
tribution data is not presently available. Gaseous hydrocarbons consist
almost entirely of methane and acetylene. Limited quantities of poly-
nuclear organic matter (POM) may also be emitted.
There is no liquid waste from this process except for yard storm
water runoff and boiler blowdown.
Solid waste is generated to a very limited extent by the dis-
posal of used fabric filters and refractory bricks. This is usually
disposed of in a landfill. This material amounts to about 0.5 to 1.0
gm/kg of product (1.0 to 2.0 pounds per ton) with about 30 percent due
16
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to the fabric filter.
6- EPA Source Classification Code (SCC)
Furnace process - Oil feed 3-01-005-04
Furnace process - Gas and oil feed 3-01-005-05
Furnace process - Gas feed 3-01-005-03
7. References
1. An Investigation of the Best Systems of Emission Reduction for
Furnace Process Carbon Black Plants in The Carbon Black Industry.
Emission Standards and Engineering Division, Office of Air
Quality Planning and Standards, Environmental Protection Agency,
April 1976.
2. Davidson, H. W., et al. Manufactured Carbon. Pergamon Press,
1968.
3. Mantel 1, C. L. Carbon and Graphite Handbook. Wiley and Sons,
Inc., 1968.
17
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CARBON BLACK (Furnace Process) PROCESS NO. 2
Product Modification and Drying
1. Function - Raw carbon black leaving the filtration step, is pul-
verized to break up any agglomerates; pelletized to facilitate handling,
and finally dried prior to storage and shipment. Pulverizing is
accomplished in a micropulverizer. The carbon black in the fluffy state
is then wetted and pelletized with water in a pin or finger-type
agitator. Pellets in the 40 to 60 mesh size, containing 30 to 40 percent
water, are formed. The pellets then enter a combined direct, indirect-
fired, rotary drum type dryer. Natural gas is used as a fuel and in
some plants this is supplemented with process off-gas. A portion
(35 to 70 percent) of the hot dryer combustion gases are passed directly
through the rotary drum to remove the evaporated water. These purge
gases containing particulate matter are vented through fabric filters
similar to those used in Process No. 1 but generally smaller.
2. Input Materials - Raw carbon black is the main feed material to
this process. Varying quantities of water are used for wetting the
carbon black and natural gas is used as a heat source.
3. Operating Parameters - Product preparation is conducted at atmos-
pheric pressure. The pulverized black at a density of 80 to 192 kg/nr
(3 to 12 pounds/ft3) is pelletized to a density of 320 to 560 kg/m3
o 23
,(20 to 35 pounds/ft"3). ' The drier is operated at a temperature of
175 to 260 C. A maximum of 75 percent of the natural gas required for
the drier can be replaced using off-gas from Process No. 1. Extensive
modification to the drier combustion chamber must generally be done
to accomodate the lower heat content off-gas fuel. Only 10 to 20 per-
cent of the total off-gas can be consumed in pellet driers.
4. Utilities - The following approximate utility rates are required:
Electricity 0.0165 kWh/kg of product
(15 kWh/ton of product)
Heat 390 kcal/kg of product
(1.4 x 106 Btu/ton of product)
Water 0.54 I/kg of product
(130 gallons/ton of product)
18
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5. Waste Streams - The purge gas from the drier contains particulate
matter. These emissions are always controlled to recover the carbon
black, and an average emission rate of 0.04 gin/kg (0.08 pounds per ton)
of product results. If a scrubber is used to control these emissions,
the liquid effluent is used in the pelletizer and no liquid waste occurs.
Some solid waste in the form of "off-spec" product results from
this process. This material is sent to a storage silo and usually
blended back into the product at a low rate.
6. EPA Source ClassificatianjCode - None exists.
7. References
1. An Investigation of the Best Systems of Emission Reduction for
Furnace Process Carbon Black Plants in The Carbon Black Industry.
Emission Standards and Engineering Division, Office of Air
Quality Planning and Standards, Environmental Protection Agency,
April 1976.
2. Davidson, H. W., et al. Manufactured Carbon. Pergamon Press,
1968.
3. Mantell, C. L. Carbon and Graphite Handbook. Wiley and Sons,
Inc., 1968.
19
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CARBON BLACK (Furnace Process) PROCESS NO. 3
Off-Ga s Combust i on
1. Function - This process consists of a combustion device used to re-
cover heat from the off-gases and/or to reduce emissions of CO, HC and
H2S. The off-gases from Process No. 1 are burned in either a CO boiler,
incinerator, flare or some combination of these devices. When a boiler
is used, steam is generated. However, a typical carbon black plant
can utilize only 40 to 60 percent of the steam that is generated when
all of the off-gases are burned.1 For a typical size carbon black
plant it is estimated that 2500 to 5300 horsepower hours per hour of
electrical energy can be generated through combustion of off-gas.
Steam can only be utilized for pump and fan drives, or to preheat
feedstock.
2. Input Materials - Process off-gas and natural gas are the two main
feed materials. The chemical characteristics of the off-gas determine
how much, if any, supplemental fuel in the form of natural gas is
required to ensure combustion. The Btu content of various grades of
carbon black are presented below based on data in reference 1.
ASTM Typical
product particle size % of total
code my production Btu/scf
N-lxx 11-19 1.0 36
N-2xx 20-25 9.7 39
N-3xx 26-30 44.0 45
N-4xx 40-48 12,8 45
N-5xx 49-60 27.0 45
N-6xx 61-100 10.5 55
At a Btu/scf level of approximately 50 (actual levels depend on CO
content, H2 content and H20 burden), an off-gas can be burned without
any supplemental fuel. Natural gas requirements increase substantially
as the heat content drops below 45 Btu/scf.
It should be noted that use of a high temperature fabric filter
(not yet technically feasible) would conceivably eliminate the need
for secondary quenching in Process No. 1. This would have a double
20
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benefit since the off-gas temperature to the off-gas combustion system
would be as much as 300 C hotter and would have a higher heat content
due to less FLO. Supplemental fuel requirements could probably be
substantially reduced or eliminated at most present and future plants
if such air pollution control technology was developed.
3. Operating Parameters - The type of control device will dictate the
exact operating conditions. Generally a fire-box temperature of about
980 C (1800 F) is maintained to ensure good combustion. Flares prob-
ably operate at a lower temperature, but quantitative data are not
available.
4. Utilities - Auxiliary, fuel in the form of natural gas is the primary
utility required for off-gas combustion. This fuel requirement will
vary with the CO content of the off-gas as described above. It should
be noted that off-gas combustion has not been done as the very low
Btu content off-gas used to represent an upper limit. The lower range
of fuel requirements are representative of presently operating systems.
Electricity 0.002 to 0.004 kWh/kg of product
(2 to 4 kWh/ton of product)
Fuel 800 to 15,800 kcal/kg of product
(3 to 60 x 1Q6 Btu/ton of product)
Water 4.1 to 8.3 £/kg of product
(1000 to 2000 gallons/ton of product)
5- Waste Streams - Trace amounts of CO, hydrocarbons and particulate
are emitted to the atmosphere. In addition, any H2S present is con-
verted to S09 and some NO is formed. These emissions are summarized
Cm A,
in the table below (source, Ref. 1).
Pollutant quantity Pollutant concentration
Pollutant kg/kg of product pg/m3
CO 0.005 2.3 x 105
Hydrocarbons 0.004 1.7 x 104
Hydrogen sulfide < 0.0003 < 1.4 x io4
Particulate 0.0010 5.0 x io4
S02 0.0180 8.5 x IO5
NO 0.0030 8.6 x IO4
21
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At these emission levels, meteorological models suggest that ambient
air quality standards for CO will not be exceeded or approached.
Furthermore, H2S will be well below the odor threshold. The impact of
the SOo emissions could conceivably contribute to a local S02 problem
in certain cases.
There is no solid waste from this system. Liquid effluent occurs
when a steam boiler is used since boiler blowdown is required. This
amounts to approximately 5 percent of the steam generated.
6. EPA Source Classification Code - None exists.
7. References
1. An Investigation of the Best Systems of Emission Reduction for
Furnace Process Carbon Black Plants in The Carbon Black Industry.
Emission Standards and Engineering Division, Office of Air
Quality Planning and Standards, Environmental Protection Agency,
April 1976.
22
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Thermal Process
The generalized flowsheet for a thermal process carbon black plant
is shown in Figure 2. Since there are no substantial environmental
impact, the entire plant is shown as one process block. Unlike the
furnace process plants, pelletizing is not normally done since thermal
blacks are inherently larger in size and easier to handle. Also, an
off-gas combustion process is not necessary since the reactor is
utilized for energy recovery.
23
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PO
9
_A
GASEOUS EMISSIONS
LIQUID WASTE
SOLID WASTE
• MAIN PROCESS STREAM
- OFF-GAS STREAMS
- UTILITY STREAMS
AIR
1
THERMAL, 4TV-1
CRACKING AND LJ=L
FILTRATION
CARBON
BLACK
PRODUCT
Figure 2. Thermal process flowsheet.
-------
CARBON BLACK (Thermal Process) PROCESS NO. 4
Cracking and Filtration
1. Function - In the thermal process, decomposition of a gaseous
hydrocarbon feed is produced by thermal cracking in the absence of air
to yield carbon and hydrogen. The product stream is then filtered to
remove carbon black and the exit gas is burned to generate heat for
additional cracking.
2. Input Materials - Natural gas is used as the input feedstock. Yields
of 0.4 to 0.5 kg of product per kg of natural gas feedstock are achieved.
This is equivalent to 8.7 cubic meters of natural gas per kg of product
(13 cubic feet per pound). Hydrogen from the cracking reaction, washed
and compressed, is used as a fuel to provide heat.
3- Operating Parameters - The cracking chamber operates at a temperature
of 1315 to 1540 C (2400 to 2800 F).1 Two refractory-lined cylindrical
furnaces (generators) are employed for the reaction. The generators,
about 12 feet in diameter and 25 feet high, are nearly filled with an
open checkerwork of silica brick. This checkerwork is first heated
by burning hydrogen generated in the decomposition reaction and/or
by additional gas fuel. While one set of checkerwork is decomposing
gas to produce carbon black, the other set is being heated by burning
the off-gas. The gas flows are then switched and the heating/decomposi-
tion cycle is repeated every 10 minutes. The decomposed gas is then
cooled by water sprays to 125 C, and the carbon black removed by a
series of cyclones and fabric filters.
4- Utilities - Electricity and water are required in this process.
Electrical requirements can be minimized by utilizing steam driven pumps
and fans- This steam can be generated on-site since an excess of
hydrogen is produced, and this can be utilized as fuel. If steam is not
generated on-site, the utility requirements will be similar to those
encountered in the furnace process, namely:
Electricity 0.22 kWh/kg of product
(200 kWh/ton of product)
25
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Water 6 I/kg of product
(1450 gallons/ton of product)
5. Haste Streams - Atmospheric emissions are very low since the off-gas
is recycled and burned to provide heat for cracking, or sent to a boiler
as fuel. Some particulate emissions occur when the reactors are switched
from the cracking to the heating cycle. This puff of carbon black is
caused by particulate buildup on the checkerwork.
There are no other waste streams except for solid waste in the form
of old fabric filters and refractory bricks.
6. EPA Source Classification Code - Thermal black process (gas feed)
3-01-005-2.
7. References
1. Kirk-Othmer Encyclopedia of Chemical Technology? Volume 4,
26
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APPENDIX A
FURNACE BLACK FEED CHARACTERISTICS
27
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Table A-l. TYPICAL FEED OIL CHARACTERISTICS
Property Typical Range
Specific gravity at 60 F 1.0 to 1.1
A.P.I, at 60 F -2.9 to 10
Carbon, % 90 to 91
Hydrogen, % 7.3 to 8.2
Sulfur, % 1 to 2.5
Ash, % 0.002 to 0.02
Sodium, % 0.2 to 0.8
Note: Coal tar products are used by some European plants, but are not used
in the United States. Due to a shortage of feedstocks, carbon black plants
are being forced to utilize feedstocks with ever increasing sulfur content
even though this is not desirable from a product quality standpoint. Sulfur
content increases from 0.85 percent to 1.50 percent have occurred at some
plants. Feedstocks with 2 to 3 percent sulfur are not uncommon. Limited
supplies and increased cost of natural gas has also led to greater dependence
on liquid feeds.
Table A-2. TYPICAL NATURAL GAS COMPOSITION
Component Mol %
Nitrogen 2.41
Carbon dioxide 0.41
Methane 91.81
Ethane 4.83
Propane 0.49
Iso-Butane 0.02
M-Butane 0.03
Iso-Pentane Trace
M-Pentane Trace
28
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APPENDIX B
COMPANY LISTING
29
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Table B-l. CARBON BLACK PLANTS - 1974
Company
Plant Location
Annual
Capacity
Millions of
Pounds
A. FURNACE PROCESS
Ashland Chemical Company
Division of Ashland Oil
Company, Inc.
Cabot Corporation
Cities Service Company
Columbian Division
Continental Carbon Company
J.M. Huber Corporation
Phillips Petroleum Company
Sid Richardson Carbon Co.
Aransas Pass, Texas
Belpre, Ohio
Ivanhoe, Louisiana
Mojave, California
Shamrock, Texas
Big Spring, Texas
Franklin, Louisiana
Pampa, Texas
Villa Platte, Louisiana
Waverly, West Virginia
Conroe, Texas
El Dorado, Arkansas
Eola, Louisiana
Franklin, Louisiana
Mojave, California
Moundsville, West Virginia
Seagraves, Texas
Ulysses, Kansas
Bakersfield, California
Phenix City, Alabama (shutdown)
Ponca City, Oklahoma
Sunray, Texas
Westlake, Louisiana
Bayton, Texas
Borger, Texas
Borger, Texas
Orange, Texas
Toledo, Ohio
Addis, Louisiana
Big Spring, Texas
TOTAL Furnace Black
154
67
240
68
109
200
384
60
196
112
110
98
66
214
50
150
95
60
71
50
122
97
109
266
132
318
95
80
80
120
3,981 (92%)
Stated capacities are approximate since they depend on type of product.
30
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Table B-l (Continued). CARBON BLACK PLANTS - 1974
Annual
Capacity
Millions of
Company Plant Location Pounds
B. THERMAL PROCESS
Cabot Corporation Big Spring, Texas (shutdown) 100
Cities Service Franklin, Louisiana 55
Commerical Solvents Sterlington, Louisiana 150
Corporation
Thermatomic Carbon
J.M. Huber Corporation Borger, Texas 44
TOTAL Thermal Black 349 (8%)
Stated capacities are approximate since they depend on type of product.
31
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APPENDIX C
ATMOSPHERIC EMISSIONS
32
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Table C-l. TYPICAL ATMOSPHERIC EMISSIONS FOR.A 90 MILLION
POUND PER YEAR CARBON BLACK PLANT0
Component
Hydrogen
Carbon dioxide
Carbon monoxide
Hydrogen sulfide
Sulfur oxide
Methane
Acety 1 ene
Nitrogen
Oxygen
Nitrogen oxide
Particulate
Water
Total
Range,
mol , %
2.7-7.5
1.5-3.3
3-7
0.005-0.1
TR-0.0153
0.1-0.35
0.05-0.5
32.5-40
0-2.5
8-100 ppma
0.048 gr/scfc
42-50
kg/hr
559
4,336
6,396
139
TR
145
174
41,221
368
8
11
36,465
89,822
Typical
kg/ kg
of product
0.11
0.91
1.3
0.03
-
0.03
0.03
8.2
0.07
-
0.002
7.3
18.0
Mol, %
6.7
2.5
5.5
0.1
TR
0.2
0.2
35.5
0.3
44 ppm
0.048 gr/scfc
49
100
Most data is near low side of range.
After fabric filter with 99.78% control. Reactor effluent contains 5,016
pounds of carbon black per hour.
Including water vapor.
A
An Investigation of the Best Systems of Emission Reduction for Furnace Process
Carbon Black Plants in the Carbon Black Industry. Emission Standards and Engineeri-
ing Division, Office of Air Quality Planning and Standards, Environmental Protection
Agency, April 1976.
33
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TECHNICAL REPORT DATA
/Please read Instructions on the reverse before completing)
I. REPORT NO.
EPA-60Q/2-77-023d
2.
3. RECIPIENT'S ACCESSION-NO.
4. TITLE ANU SUBTITLE
Industrial Process Profiles for Environmental Use:
Chapter 1* - Carbon Black Industry
5. REPORT DATE
February 1977_
6. PE R F O'R MI N"G" OR GANIZ AT I ON CODE
7 AUTHOR(S)
Richard W. Gerstle and John R. Richards (PEDCo)
Terry B. Parsons and Charles E. Hudak, Editors
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Radian Corporation
8500 Shoal"Creek Boulevard, P.O. Box 99U8
Austin, Texas 78766
10. PROGRAM ELEMENT NO.
1AB015: ROAP 21AFH-025
11. CONTRACT/GRANT NO.
68-02-1319, Task
12. SPONSORING AGENCY NAME AND ADDRESS
Industrial Environmental Research Laboratory
Office of Research and Development
U.S. ENVIRONMENTAL PROTECTION AGENCY
Cincinnati, Ohio ^5268
13. TYPE OF REPORT AND PERIOD COVERED
Initial: 8/75-11/76
14. SPONSORING AGENCY CODE
EPA/600/12
15. SUPPLEMENTARY NOTES
16. ABSTRACT
The catalog of Industrial Process Profiles for Environmental Use was developed as an
aid in defining the environmental impacts of industrial activity in the United States
Entries for each industry are in consistent format and form separate chapters of the
study.
The carbon black industry is a distinctive part of the chemical industry, which
processes hydrocarbon feedstocks (mainly heavy oils) into finely divided carbon
black particle for use largely in tires and, to a lesser extent, pigments, cement,
and cos:r.etics. The industry sole products are various grades of carbon black. Tvo
industrial process flow diagrams and four process descriptions have been prepared to
characterize the industry. Within each process description available data have been
presented on input materials, operating parameters, utility requirements and waste
streams. Data related to the subject matter, including feedstock characteristics,
company listings and atmospheric emissions are included as appendices.
DESCRIPTORS
Pollution
Industrial Processes
Chemical Engineering
Carbon Black
3. DISTRIBUTION STATEMENT
Release to the Public
I). IDENTIFIERS/OPEN ENDED TERMS
Process Assessment
Environmental Impact
19. SECURITY CLASS (TMt Report)
_....Ua£lfls.sified
20. SLCUHITY CLAbS (This page)
Unclassified
c. COSATI Fickl/Group
13B
13H
0?A
11G
21. NO. OF PAGES
10
22. PRICE
EPA ^orm 2220-1 (9-73)
34
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