Materials Balance for Benzene: Level II


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Materials Balance
for Benzene
Level II

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TECHNICAL REPORT DATA
/Please read fnsimctions on the reverse before completing)
1 . REPORT NO. 2.
EPA-560/13-80-009
3. RECIPIENT'S ACCESSIOI^NO.
PB8T 17 7*12
•J. TITLE AND SUBTITLE
Materials Balance for Benzene: Level II
E. REPORT DATE
May 1980
6. PERFORMING ORGANIZATION CODE
7, AUTHORlS)
Robert L. Hall, Ronald Burger, Frank Montecalvo
8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
JRB Associates, Inc.
8400 Westpark Drive
McLean, VA 22102
10. PROGRAM ELEMENT NO.
11. CONTRACT/GRANT NO.
68-01-5793
12. SPONSORING AGENCY NAME AND AOORESS
Survey and Analysis Division (TS-793)
Office of Pesticides and Toxic Substances
U.S. Environmental. Protection Agency
Washington, DC 20460
13. TYPE OF REPORT AND PERIOD COVERED
Final Report
14. SPONSORING AGENCY CODE
15. SUPPLEMENTARY NOTES
Project Officer - Michael Callahan
i6. abstract a Level II-materials balance was performed on benzene. Data are reported for
benzene production from petroleum by four processes (catalytic reformation, toluene
dealkylation, toluene disproportionation, and isolation from pyrolysis gasoline) and
for production from coal during coking. Amounts of benzene consumed for the synthesis
of eight direct derivatives (ethylbenzene, cumene, cyclohexane, nitrobenzene, maleic
anhydride, mono- and dichlorobenzene, alkylbenzenes, and biphenyl) and exports are pre-
sented. These uses constitute approximately 99 percent of total benzene usage. Non-
consumptive uses .(solvents snd pesticide component) are also tabulated. Releases due
to each of the above processes are reported or estimated where possible using published
and unpublished data. In addition, releases due to indirect production (refinery oper?-
tion, coke oven operations, oil spills, non-ferrous metals manufacturing, ore mining,
wood processing, coal mining, and two phases of the textile industry) are presented.
Production of benzene as a component of gasoline and releases due to all phases of
gasoline use are estimated. Locations of sites with high levels of benzene releases
due to production and use are tabulated: the major "hotspots" are Baton Rouge,
Louisiana; Houston/Galveston, Texas; Midland, Michigan; and Puerto Rico. The uncer-
tainty ranges of all numbers used or derived in this report are evaluated when possible
and tabulated. Data gaps are evaluated and general recommendations are presented. The
results of the report are summarized in two figures: the Environmental Flow Diagram for
benzene in Appendix A, and the Materials Balance Flow Diagram in the Executive Summary.
17. KEY WORDS AND DOCUMENT ANALYSIS
a. DESCRIPTORS
b.IDENTIFIERS/OPEN ENDED TERMS
c. COSATI Field/Group



13. DISTRIBUTION STATEMENT
Release Unlimited
19. SECURITY CLASS (This Report)
Unclassified
21. NO. OF PAGES
20. SECURITY CLASS (This page)
Unclassified
22. PRICE
EPA Form 2220*1 (9-73)

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FINAL REPORT
LEVEL II MATERIALS BALANCE
BENZENE
Prepared for:
U.S. ENVIRONMENTAL PROTECTION AGENCY
OFFICE OF PESTICIDES AND TOXIC SUBSTANCES
SURVEY AND ANALYSIS DIVISION
Task Mo. 21
Contract No. 68-01-5793
Michael Callahan - Project Officer
Elizabeth F. Bryan - Task Manager
Prepared by:
JRB ASSOCIATES, INC.
8400 Westpark Drive
McLean, Virginia 22102
Project Manager:	Robert L. Hall
Task Leader:	Robert L. Hall
Contributing Writers:	Ronald Burger
Frank Montecalvo
Submitted: December 8, 1980
i' CL;

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This document has been reviewed and approved for publica-
tion by the Office of Testing and Evaluation, Office of
Pesticides and Toxic Substances, U.S. Environmental Pro-
tection Agency. Approval does not signify that the con-
tents necessarily reflect the views and policies of the
Environmental Protection Agency, nor does the mention of
trade names or commercial products constitute endorsement
or recommendation for use.
I' b

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ABSTRACT
A Level II materials balance was performed on benzene. Data are
reported for benzene production from petroleum by four processes (cata-
lytic reformation, toluene dealkylation, toluene disproportionation, and
isolation from pyrolysis gasoline) and for production from coal during
coking. Amounts of benzene consumed for the synthesis of eight direct
derivatives (ethylbenzene, cumene, cyclohexane, nitrobenzene, raaleic
anhydride, mono- and dichlorobenzene, alkylbenzenes, and biphenyl) and
exports are presented. These uses constitute approximately 99 percent
of total benzene usage. Nonconsumptive uses (solvents and pesticide
component) are also tabulated. Releases due to each of the above pro-
cesses are reported or estimated where possible using published and
unpublished data. In addition, releases due to indirect production
(refinery operation, coke oven operations, oil spills, non-ferrous
metals manufacturing, ore mining, wood processing, coal mining, and two
phases of the textile industry) are presented. Production of benzene as
a component of gasoline and releases due to all phases of gasoline use
are estimated. Locations of sites with high levels of benzene releases
due to production and use are tabulated: the major "hotspots" are Baton
Rouge, Louisiana; Houston/Galveston, Texas; Midland, Michigan; and Puerto
Rico. The uncertainty ranges of all numbers used or derived in this
report are evaluated when possible and tabulated. Data gaps are evalua-
ted and general recommendations are presented. The results of the report
are summarized in two figures: the Environmental Flow Diagram for benzene
in Appendix A, and the Materials Balance Diagram in the Executive Summary.
i '(Ls

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TABLE OF CONTENTS
PaSe
EXECUTIVE SUMMARY	S-l
1.0 INTRODUCTION	1-1
1.1	PROPERTIES OF BENZENE	1-1
1.2	ENVIRONMENTAL FLOW DIAGRAM FOR BENZENE	1-1
2.0 DIRECT PRODUCTION OF BENZENE	2-1
2.1	PRODUCTION FROM PETROLEUM	2-1
2.1.1	Producers and Locations	2-2
2.1.2	Amounts Produced	2-2
2.1.3	Production by Catalytic Reformation	2-6
2.1.4	Production of Benzene by Dealkylation	2-9
2.1.5	Production of Benzene by Transalkylation	2-13
and Disproportionation
2.1.6	Production of Benzene from Pyrolysis Gasoline 2-17
2.1.7	General Releases Due to Petroleum-Derived	2-18
Benzene Production
2.1.8	Releases of Benzene Due to Transportation,	2-22
Loading and Storage Associated with Produc-
tion of Petroleum
2.2	BENZENE PRODUCTION FROM COAL	2-29
2.2.1	Summary	2-29
2.2.2	The Process	2-29
2.3	SUMMARY	2-32
3.0 INDIRECT PRODUCTION OF BENZENE	3-1.
3.1	INDIRECT PRODUCTION OF BENZENE FROM REFINING	3-1
OPERATIONS
3.2	BENZENE RELEASES FROM COAL COKING OPERATIONS	3-4
3.3	INDIRECT PRODUCTION OF BENZENE FROM VARIOUS SOURCES	3-7
3.3.1	Contamination of Benzene Co-Products	3-7
3.3.2	Benzene Contamination of Petroleum-Derived	3-7
Products
3.3.3	Benzene Precursors in Other Fractions	3-10
3.3.4	Benzene in Gas Well Condensates	3-10
ii

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TABLE OF CONTENTS (continued)
3.3.5	Benzene Releases from Resource Mining and	3-12
Processing Operations
3.3.6	Benzene Releases from Oil Well Drilling	3-12
3.3.7	Benzene Releases Due to Oil Spills	3-12
3.3.8	Benzene Synthesized from Aliphatic	3-13
Hydrocarbons
4.0 IMPORTS OF BENZENE	4-1
4.1	AMOUNT IMPORTED	4-1
4.2	RELEASES DUE TO IMPORTS	4-1
5.0 CONSUMPTIVE USES OF BENZENE	5-1
5.1	CONSUMPTIVE USES: TOTALS	5-1
5.2	CATEGORIES OF USE	5-1
5.3	RELEASES BY CATEGORY OF USE	5-1
5.3.1	Consumption of Benzene by Ethylbenzene	5-1
Synthesis
5.3.2	Consumption of Benzene by Cumene Synthesis	5-12
5.3.3	Consumption of Benzene by Cyclohexane	5-20
Synthesis
5.3.4	Consumption of Benzene by Maleic Anhydride	5-26
Synthesis
5.3.5	Consumption of Benzene by Nitrobenzene	5-33
Synthesis
5.3.6	Consumption of Benzene by Chlorobenzene	5—41
Synthesis
5.3.7	Consumption of Benzene by Synthesis of	5-46
Alkylbenzenes
5.3.8	Consumption of Benzene by Synthesis of	5—51
Anth raquinone
5.3.9	Consumption of Benzene by Synthesis of	5-51
Biphenyl
5.3.10	Benzenesulfonic. Acid	5-54
5.3.11	Exports of Benzene	5—54
iii

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TABLE OF CONTENTS (continued)
Page
6.0 NONCONSUMPTIVE USES OF BENZENE	6-1
6.1	TOTAL NONCONSUMPTIVE USE	6-1
6.2	CATEGORIES OF USE	6-1
6.3	RELEASES BY CATEGORY OF USE	6-1
6.3.1	Use of Benzene as a Solvent	6-1
6.3.2	Changes in Benzene Inventory	6-5
7.0 USE OF BENZENE AS A FUEL COMPONENT	7-1
7.1	BENZENE IN GASOLINE	7-1
7.1.1	Overview	7-1
7.1.2	Content of Benzene in Gasoline	7-3
7.1.3	Benzene Releases Due to Transportation of	7-5
Gasoline from Refinery to Bulk Terminal
7.1.4	Benzene Releases Due to Storage of Gaso-	7-8
line at Rulk Terminals
7.1.5	Releases Due to Transportation of Gaso-	7-11
line from Bulk Terminals to Service
Stations or Bulk Plants
7.1.6	Benzene Releases Due to Gasoline Storage	7—12
at Bulk Plants
7.1.7	Benzene Releases Due to Transportation of	7-15
Gasoline from Bulk Plants to Service
Stations and Other Customers
7.1.8	Benzene Releases Due to Service Station	7-16
and Other Similar Operations
7.1.9	Vehicle Releases	7-19
7.2	BENZENE CONTENT OF OTHER FUELS	7-25
8.0 SUMMARY OF DISPOSAL/DESTRUCTION AS END PRODUCTS	8-1
9.0 LOCATIONS OF BENZENE RELEASE SITES	9-1
10.0 SUMMARY OF UNCERTAINTIES	10-1
11.0 DATA GAPS AND RECOMMENDATIONS	11-1
11.1	RELEASES DUE TO BENZENE PRODUCTION BY COKE OVEN	11-1
PLANTS
11.2	TREATMENT OF SOLID RESIDUES	11-1
iv

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TABLE OF CONTENTS (continued)
Page
REFERENCES
APPENDIX A - ENVIRONMENTAL FLOW DIAGRAM FOR BENZENE	A-l
APPENDIX B - PROCESS FLOW DIAGRAMS FOR PRODUCTION AND	B-l
USES OF BENZENE
APPENDIX C - CALCULATIONS	C-l
v

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LIST OF TABLES
Tab 1b	page
ES-1	Summary of Consumptive Uses of Benzene	S-3
ES-2	Releases of Benzene Due to Consumptive Uses (1978) S-4
2.1	Available Data on the Percent of Benzene in Crude 2-2
Oil
2.2	Producers and Production, 1975-1979	2-4
2.3	Chemical Reactions in Reforming Hydrocarbons in	2-7
a Naphtha Cut to Form Benzene
2.4	Methods of Aromatic Recovery from Petroleum	2-7
2.5	Estimated Distribution of Benzene Not Recovered	2-10
by the Extraction Process
2.6	Benzene Releases Due to the Production of Benzene 2-11
by the Extraction Process
2.7	Feedstock and Chemical Reactions for the Dealkyla- 2-12
tion Method of Benzene Production
2.8	Process Releases from the Dealkylation Method	2-14
2.9	Difference Between Disproportionation and Trans-	2-15
aIkylation
2.10	Potential Sources of Benzene Releases from the	2-16
Transalkylation-Disproportionation Method
2.11	Pyrolysis Gasoline Feedstocks and Quantities of	2-18
Benzene Produced from Each Type
2.12	Generalized List of Potential Benzene Releases	2-19
from Pyrolysis Gasoline Processes
2.13	Summary of Estimated Benzene Releases for the Four 2-20
Petroleum Production Processes
2.14	Summary of the Estimated Overall 3enzene Releases 2-21
During Production from Petroleum
2.15	Benzene Release Factors and Calculations for	2-24
Storage Releases
2.16	Benzene Release Factors and Calculations for	2-25
Loading Operations
2.17	Benzene Releases and Calculations for Tranporta-	2-28
tion
2.18	Possible Sources of Benzene Releases from Coal	2-31
Coking
2.19	Total Benzene Produced in the United States During 2-33
1978
vi

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LIST OF TABLES (continued)
Table	Page
2.20 Total Benzene Releases Due to Petroleum-Derived	2-34
Benzene Production in 1978
3.1	Benzene Release Factors for Petroleum Refineries	3-2
3.2	Petroleum Industry Disposal of Wastes Containing	3-5
Benzene
3.3	Benzene Release Factors and Calculations for Coal 3-7
Coking Operations
3.4	Co-Products of Benzene Production Contaminated	3-10
with Benzene
3.5	Estimated Benzene Content of Some Petroleum	3-11
Products
3.6	Benzene Precursors, Reaction and Crude Oil Frac-	3-12
tions Containing Benzene Precursors
3.7	Gross Annual Discharges of Benzene to Water in	3-13
1976 from Resource Obtaining and Processing
4.1	Benzene Imports, 1975-1979	4-1
5.1	Consumptive Uses of Benzene, 1978	5-2
5.2	Consumptive Uses of Benzene, 1975-1979	5-3
5.3	Summary of Estimated Benzene Releases to Air Due to 5-6
Ethylbenzene and Styrene Synthesis
5.4	Summary of Estimated Benzene Releases to Water Due 5-9
to Ethylbenzene/Styrene Synthesis
5.5	Carry-Over of Benzene into Ethylbenzene, Styrene	5-11
and Polystyrene
5.6	Summary of Estimated Benzene Releases to Air Due	5-15
to Cumene/Phenol Synthesis
5.7	Carry-Over of Benzene into Cumene	5-19
5.8	Summary of Estimated Benzene Releases to Air Due	5-23
to Cyclohexane Synthesis
5.9	Carry-Over of Benzene into Cyclohexane	5-25
5.10	Summary of Estimated Benzene Releases to Air Due	5-29
to Maleic Anhydride Synthesis
5.11	Carry-Over of Benzene into Maleic Anhydride	5-32
5.12	Summary of Estimated Benzene Releases to Air Due	5-35
to Nitrobenzene Synthesis
5.13	Summary of Estimated Benzene Releases to Water	5-38
Due to Nitrobenzene Synthesis
vii

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LIST OF TABLES (continued)
Table	Page
5.14	Carry-Over of Benzene into Nitrobenzene and Aniline	5-40
5.15	Summary of Estimated Benzene Releases to Air Due to	5-44
Chlorobenzenes Synthesis
5.16	Carry-Over of Benzene into Chlorobenzene	5-47
5.17	Carry-Over of Benzene into Alkylbenzenes	5-52
5.18	Release Factors and Releases Due to Benzene Export,	5-55
1978
6.1	Nonconsumptive Uses of Benzene	6-2
6.2	Estimated Releases of Benzene Due to Use as a	6-4
Solvent, 1978
6.3	Pesticide Products Using Benzene as an Active	6-6
Ingredient
7.1 Estimated Benzene Content of Fuels	7-26
9.1 Geographic Locations of Benzene Release Sites	9-2
10.1 Summary of Uncertainties	10-2
viii

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LIST OF FIGURES
Figure

Page
ES-1
Materials Balance Diagram for Benzene, 1978
S-8
2.1
Producers of Benzene from Petroleum, 1978
2-3
2.2
Coal-Derived Benzene Producers
2-30
3.1
Benzene: Refinery Emissions by State (kkg)
3-3
3.2
Benzene: Coke Oven Emissions by State (kkg)
3-9
5.1
Production of Ethylbenzene
5-5
5.2
Production of Cumene
5-13
5.3
Production of Cyclohexane
5-21
5.4
Production of Maleic Anhydride
5-27
5.5
Production of Nitrobenzene
5-34
5.6
Production of Chlorobenzene
5-42
5.7
Production of Alkylbenzene
5-48
7.1
Gasoline Product Flow and Releases of Benzene
to Air
7-2
7.2
Benzene in Gasoline
7-4
ix

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EXECUTIVE SUMMARY
This Level II materials balance on benzene was performed in response
to Task Order No. 21 under Contract No. 63-01-5793 with Survey and Analy-
sis Division, Office of Pesticides and Toxic Substances, EPA.
The Materials Balance Summary Diagram for benzene is included at
the end of this Executive Summary. It shows only those processes for
which data were obtainable. The more comprehensive Environmental Flow
Diagram for benzene appears as Appendix A of the report. All data refer
to the year 1978 unless otherwise stated.
DIRECT PRODUCTION
3enzene is obtained by the fractionation and enrichment of fossil
fuels. It is produced from petroleum by four processes:
1.	Catalytic reforir.aticn of the naphtha petroleum fraction;
2.	Dealkylation of toluene;
3.	Disproportionation of toluene; and
4.	Isolation from pyrolysis gasoline as a byproduct of ethylene
manufacture.
Benzene is obtained from coal by extraction from the light oil formed
during coking. This extraction may be done either at the coking plant
or after sale of the light oil to refineries. The contribution by each
process and the total production of benzene from petroleum are shown
below:
Process
Benzene Produced, 1978
(kkg) (7> of Total)
Catalytic reformation
2,360,000
48
Toluene dealkylation
1,300,000
2 6
Toluene disproportionation
121,000
9
Pyrolysis gasoline
925,000
19
Petroleum Subtotal
4,710,000
95
Extraction of light oil by coking
plants
178,000
4
Extraction of light oil by refineries
or process unknown
74,000
1
Petroleum and Coal Total
4,960,000
100
S-l

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Total benzene releases due to the four production processes (includ-
ing storage and transport) were estimated to be 7,000 to 11,800 kkg. Of
these releases, 6,400 to 11,200 kkg were estimated to go to air and 620
kkg to water. No estimate of releases to landfills was possible. The
above values do not include benzene released during gasoline production
by refineries.
3enzene releases due to benzene-producing coke oven operations could
not be estimated.
INDIRECT PRODUCTION
Indirect sources of benzene production were also analyzed for ben-
zene releases. Total estimated benzene releases were as follows:
refinery operations, including gasoline production, 20,000 kkg to air,
1 kkg to water, and 228,000 kkg to landfills; coke oven operations,
3,000 to 59,000 kkg to air; and oil spills, 30 to 11,000 kkg to water.
Releases from miscellaneous operations are listed on the Materials
Balance Summary Diagram.
Benzene imports amounted to 225,000 kkg in 1978. The estimated
releases attributed to importing were 13 kkg to air and 13 kkg to water.
CONSUMPTIVE USES
The predominant use of benzene is as a starting material for the
synthesis of other organic compounds. The eight major direct deriva-
tives of benzene and their contributions to total benzene consumption are
listed in Table ES-1.
A summary of the releases due to synthesis of each product is shown
in Table ES-2.
Exports accounted for 151,000 kkg of benzene in 1978. Estimated
releases due to exportation (dockside loading) were 15 kkg to air, 2 kkg
to water, and a negligible amount to land.
N ON CON S UMPTIV5 USES
Less than 5 percent of benzene production in 1978 was used noncon-
sumptively; that is, benzene was not coverted to another compound before
use. The categories of nonconsumptive use and the estimated amounts
used are as follows:
IMPORTS
EXPORTS
Use
Benzene Used (kkg)
Solvent
Pesticide
9,600
Unknown
S-2

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Table ES-1 Summary of Consumptive Uses of Benzene
Product
Formed by Reacting
Benzene with:
Secondary Products
or Uses
benzene Used,
1978
( k kg )
Consumptive Use
(% of tol.al)
Ethylbenzene
Ethylene
Styrene; polystyrene
2,810,000
54
Cumene
Propylene
Phenol
1,030,000
20
Cyc lohexane
Hydrogen
Cyclohexanone; Nylon 66
836,000
16 i
I
Ni trobenzene
Nitric acid
Anilane
.1.70,000
3
Ch.l orobenzenes
Chlorine
Chemical intermediates
134,000
3
|
Al. k.y lbenzenes
1.0- to 14-Carbon
alkyl chlorides
Detergents
132,000
i
3 |
Maleic; aahydfi.de
Oxidant
Chem 1 c a 1 int. ermed i a t e s
111,000
2
Biplicnyl
Itself (with heat)
PCBs; Dyes
	7 ,000
5,230,000
0.1 !
101.1*
		 	i
Totals do not add to 100% due to rounding.

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Tah.le KS-2 Releases of benzene Due to Consumptive Uses (1.978)
Product
I
.stiinated Releases (kkg) to:


Percent of
Synthesized
Air
Water
Land
Total
Total
1 Cthylbenzene
3,900
1 20
NK*
\, 000
36
Cumfine
2,000
40
NK
2,000
18
Cyc J.ohexane
290
~0
NK
290
3
NiLi:ohenzeue
340
lb
NK
360
3
Maieic Anhydride
3,600
8
-w 0
3,600
33
Ciilorobeiizen.es
340
16
NK
360
3
Alky lb wtz enew
170
35
NK
200
2
Blphenyl
4.1
NK
NK
41
0,4
TOTALS
11,000
240
NK
- - -
11,000

"NK - No L known

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Solvent use of benzene has decreased since the 1977 OSHA Emergency
Benzene Standard and the 1977 ban on use of benzene in consumer goods by
the Consumer Products Safety Coir.mission. Releases due to solvent use in
19 78 were estimated to be 1,500 kkg to air, 1,500 kkg to water, and an
unknown amount to land.
The inventory of benzene as of January 1, 1979, was 272,000 kkg less
than on January 1, 1978. This decrease in inventory is treated as
increased supply when benzene sources and sinks are balanced.
BENZENE AS A FUEL CONSTITUENT
The largest single source of benzene releases stems from its pre-
sence as a minor component of gasoline. The production of gasoline by
refineries is a major indirect source of benzene, generating an estima-
ted 4.44 x 10^ kkg of benzene in 1979. Releases due to refining were
included under indirect production with petroleum refining operations.
Other sources of releases are listed below:
Process	Releases to air, 1979 (kkg)
Gasoline storage	4,700 - 6,700
Gasoline transport	4,600 - 8,200
Gasoline vending	1,200 - 6,100
Gasoline consumption	58,000 - 165,000
Sum for gasoline-powered
automobiles, motorcy-
cles, trucks and buses	69,000 - 186,000
The difference between the amount of benzene consumed in gasoline
(4.44 x 106 kkg) and total benzene releases due to fuel use (1.9 x 10^
kkg) was 4.3 x 10^ kkg. This value represents the difference between
benzene destroyed by combustion and that generated by combustion. Since
the amount generated by combustion could not be estimated, this differ-
ence is reported as benzene destroyed.
Geographic distribution of benzene releases due to gasoline use
are assumed to be directly related to population density. Data to con-
firm this assumption are available from the U.S. Department of Transpor-
tation, but were not received in time for inclusion in this report.
DISPOSAL/DESTRUCTION OF END PRODUCTS
No information was available to permit estimation of benzene
releases due to incineration of benzene-containing end products.
It was estimated that 760 kkg of benzene from refinery wastes were
placed in landfills in 1978. It was not possible to estimate the dis-
tribution of this waste to water and air. In addition to benzene
destroyed during gasoline combustion, an estimated 7,900 kkg were
destroyed by emission controls during solvent use or refinery opera-
tions .
S-5

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LOCATIONS OF MAJOR BENZENE RELEASE SITES
Tabulation of sites and estimated benzene releases at those sites
indicated that the top five areas for potential benzene releases were
Iberville Parish, Louisiana; Harris and Galveston counties, Texas;
Midland, Michigan; and Puerto Rico. This tabulation does net include
releases due to the presence of benzene in gasoline.
UNCERTAINTIES AND DATA GAPS
Whenever a basis for evaluation existed, an attempt was made to
quantify the uncertainties of estimates. These uncertainties were
expressed as a range of values or a percentage.
The following data gaps were encountered in performing this study:
1.	Lack of information on benzene releases at coke ovens. A
literature search and industry inquiries are recommended.
2.	Lack of information on generation and disposal of benzene-
containing solid residues, during production and consumptive
uses. Industry inquiries are recommended.
SUMMARY OF RELEASES BY CATEGORY
The table below summarizes estimated releases by major category of
production and uses.
i_
Estimated Releases (kkg)"1" to:
Category	Air	Water	Land Total
Production from	6,400-	620	?	7,000-
petroleum	11,2 00	11,800
Production from coal	?	?	?	?
Imports	13	13	?	25
Indirect production	23,000-	200-	?	23,000-
79,000	11,000	§0,000
Consumptive uses	11,000	240	?	11,2CO
Nonconsumptive uses	1,500	1,500	?	3,000
Component of gasoline	69,000-	?	?	69,000-
186,000	186,000
SUMS: 111,000-	2,000-	? 113,000-
290,000	13,000	302,000
1. A range of values is not meant to be a statistical range or set
of error limits, but results from differing independent esti-
mates of the releases.

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SUMMARY: MATERIALS BALANCE FOR BENZENE
The diagram summarizes the data and estimates available at present
for the materials balance for benzene. It shows a breakdown of the
categories in the table above into individual processes. Operations for
which no data were available were not included. The diagram also charac-
terizes the uncertainties of the release estimates as described in the
key below the diagram.
The "balance" equation for the materials balance is shown below.
It was formulated by using the upper value in a range of values as
follows:
Benzene ava ilable
Production + Imports +
Inventory Decrease
Benzene accounted for by uses +
Losses + Storage
Consumptive uses + Exports + Carry-
over + Disposal/Destruction +
Releases
9,995,000 kkg
5,380,000 kkg + 12,000 kkg +
4,270,000 kkg + 302,000 kkg
9,964,000
The apparent imbalance of 31,000 kkg (0.3 percent of available
benzene) is probably explained by the fact that consumptive use amounts
were calculated independently from direct production amounts. We
believe that the apparent imbalance is within the uncertainty ranges
of the respective totals.
S-7

-------
ft
:1 *V.

4 CfO
Jl I	1 *>
>0:-; -
jn <>-, •
i?a, /.u i-
Figura ES 1: Materials Balance.for Benzana, 1978 ikkgl

-------
1.0 INTRODUCTION
This Level II materials balance on benzene was prepared in response
to a task order from Survey and Analysis Division, U.S. Environmental
Protection Agency. The report is organized according to the processes
during which benzene might be released to the environment (direct pro-
duction, consumptive use, etc.).
In the tables and figures reporting release data and estimates,
the term "releases to land" was defined as meaning "material applied to
the soil," as opposed to material applied to a landfill. A landfill
has been interpreted as a form of waste storage rather than as a sink.
The rationale was that benzene-containing solids in a landfill would
readily lose benzene by leaching or evaporation to yield water or air
releases. Therefore, quantities of benzene-containing solids applied to
a landfill would be apportioned to air and water to reflect long-term
reality. On the other hand, actual "releases to land" would include use
of pesticides, fertilizers, or other chemicals that would yield benzene
due to microbial or photochemical degradation. Such releases would be
tabulated as indirect production of benzene.
Data for certain sections of this report were provided by Yersar,
Inc., under directive of Monitoring and Data Support Division, U.S.
Environmental Protection Agency. In particular, Versar data were used
in the estimation of releases to water during consumptive uses.
1.1 PROPERTIES OF BENZENE
Benzene is a clear, flammable liquid with a pungent odor. Its
physical properties are summarized below (Weast 1977-78; Strecher 1968):
Benzene's physical properties indicate a compound likely to be
released to air or to evaporate to air from the surface of a biphasic
water mixture. 3enzene's density value has been used to convert volumes
to kkg. No temperature correction was applied to the density value.
1.2 ENVIRONMENTAL FLOW DIAGRAM FOR BENZENE
Appendix A shows the environmental flow diagram for benzene. This
diagram attempts to demonstrate as many as possible of the sources and
uses of benzene, as well as potential points of release to the environ-
ment. It is not our purpose to discuss the diagram in detail in this
report. It serves as a guide, however, in formulating the questions to
be asked in this and other benzene materials balances.
Melting Point
Boiling Point
Density
Solubility in H90
5.5°C
80.IOC
0.87865 g/cc
0.70 g/1 at 25°C
Temperature at which -36.7°C
vapor pressure = 1 Torr
1-1

-------
2.0 DIRECT PRODUCTION OF BENZENE
Benzene is commercially produced by three routes: from petroleum
by various methods; from coal during coke production; and from conden-
sates from ga3 wells. While coal was the original commercial source of
benzene, petroleum is the primary source of benzene today (Kirk-Othmer
1976). In 1978, according to the U.S. International Trade Commission
(USITC), 178,000 kkg of benzene were obtained from coal while 4,780,000
kkg were derived from petroleum and gas well condensates. The flow of
benzene through a refinery is affected by refinery product mix, types
of crude processed, types of processes and equipment, the market, and
market conditions for a specific refinery (Appendix B-l). Numerous indus-
trial contacts indicated variation of these parameters not only between
companies, but among the refineries of the same company as well.
As a result of the diverse sources of variation in benzene produc-
tion, Chapters 2 and 3 are devoted to this process. Chapter 2 presents
generalized models of the benzene production processes and the releases
generated by these processes as estimated from numerous industry con-
tacts and accessible literature. Chapter 3 presents information on
other operations in a petroleum refinery that may be a source of ben-
zene releases and other possible indirect sources of benzene releases.
2 .1 PRODUCTION FROM PETROLEUM
Benzene is a component of crude oil in concentrations ranging from
0.001 to 0.4 percent (Versar 1977). Table 2.1 is a compilation of the
available data on the concentration of benzene in crude oil. Recovery
of benzene is uneconomical unless its concentration i3 increased by some
catalytic or thermal reaction.
The four basic commercial methods used to increase the benzene con-
centration in petroleum and then isolate it are:
1.	Catalytic reformation,
2.	Dealkylation of toluene,
3.	Disproportionation of toluene, and
4.	Isolation from pyrolysis gasoline (Kirk-Othmer 1976).
These methods are listed in order of decreasing commercial significance.
Process descriptions of these methods and the types and quantities of
benzene releases generated are presented in Sections 2.1.3 through 2.1.6.
Some petroleum refineries also recover benzene from coal-derived
light oil. This benzene is included in the total production from coal.
One refinery is known to produce small quantities of benzene from
condensates recovered from gas wells. This benzene is included in the
total production from petroleum.
2-1

-------
Table 2.1 Available Data on the Percent of Benzene in Crude Oil


Benzene in

Source of
crude oil

Crude Oil
(% by volume)
Reference
Pennsylvania
0. OA
Leverson and Berry


1967
Bradford,
0.06
Shreve and Morris
Pennsylvania


East Texas
0.07
Shreve and Norris
Ponca City,
0.15
Shreve and Morris
Oklahoma


Worldwide range
0.001 to 0.4
Versar 1977
Estimated average
0.15
Kara and Lee 1978

2.1.1	Producers and Locations
The map in Figure 2.1 shows the locations of U.S. plants producing
benzene from petroleum. The majority of these are located on the Texas
Gulf Coast, specifically in the Houston and Corpus Christi areas.
A compilation of the U.S. producers of benzene from petroleum, by
type of process used, is presented in Table 2.2. Company names and
locations were compiled from information contained in USITC publica-
tions, Versar (1979), Neufeld et al. (1978), and SRI (1977). Some
plants were listed in the literature as using more than one process
without indication of relative capacities. In these cases, plant capa-
city was assumed to be evenly distributed among the processes listed.
No allocation was made to the process of recovering benzene from light
oil unless specifically indicated in the literature. The final column
of the table indicates whether the production was captiveiy consumed
and contacts the percentage of captive consumption.
2.1.2	Amounts Produced
The estimated production by each plant producing benzene from
petroleum is also given in Table 2.2. The years 1975-1S79 are
included.
Estimated production (kkg) for a given refinery in a given year
was calculated by using the following formula:
2-2

-------
Location t»
ro
(
U)

- -1
Unplotted - Channelview, TX; St. Croix, VI; Penuelas, PR; Guaynm/i, PR; Alliance, LA; Taft, LA
Figure 2.1 Producers of Benzene from Petroleum, 1978

-------
Table 2.2 Producers and Production, 1975-1979
(Sources: A.D. Little, Inc. 1977; SRI 1977; Versar 1979; Neufeld et al. 1978)
Estimated Production'* (kkg)
Production Processes 2
Company
Location
1979
1978
1977
liZi
19 75

and U.se
Allied Chemical
Minnie, TX



8,520
5.6HIJ




Anerada Hess Corp.
St. Croix, Virgin Islands
162,000
146,000
159,000
71,000
47.400
CR



American Petroflna, l:ic.
Port Arthur, TX



42,600
28,400
C



(Cosden Oil h Chemical Co.)
Big Spring, TX
144,000
130,000
142,000
L28.000
85,300
CR.
, TD


Ashland Oil, Inc.
Ashland, KY
159,000
144,000
156,000
142,000
95,000
CR,
, TO,
, 1.0


North Tonawanda, HY
57,200
51,700
56,200
42,600
28,400
CR,
, LO


Atlantic Richfield Co.
Houston, TX
139,000
126,000
103,000
125,000
83,400
CR,
, TP



Wilmington, CA
29,800
27,000
29,300
34,100
22,700
CR




Channelv1cu, TX
162,000
146,000
78,200


I'O



Charter International Oil Co.
Houston, TX
12,400
11,200
12,200
14,200
9,470
CR



Clti.es Service Co., Inc.
Lake Charles, TA
62,100
56,200
6.1,100
71,000
47,400
CR



Coastal States Gas Prod. Co.
Corpus Chrl.uLl, TX
174,000
157.000
171,000
199,000
1:3:4,000
ViZ C,
CR,
TD
Cormnonweal t:h 01!. Kefiaing Co.
Penuelas, Puerto Rico
460,000
416,000
452,000
525,000
350,000
PC,
, CR,
, TD,
, PG
(Commonwealth Petrochemicals)










Crown Central Fetro.leum Corp.
Pasadena, TX
57,200
51,700
56,200
65,300
43,600
CK,
, ID


Dnw CJu-micul On.
Hay City, MI
74,600
67,300
73,300
85,200
56,900

TO,
PG,
L0

Freepo rI, TX
124,000
1.12,000
.122,000
142,000
94 ,700
C,
TD,
PG


riaquenilne, LA
149,000








Eastman-Kodak Co.
Longview, TX
?
?
1
?
?




{Texas Eastman Dlv.)










Exxon Corp.
Baton Kouge, LA
174.000
15/,000
171,000
185.000
123,000
CR,
, PG



Baytown, TX
149,000
135.000
147,000
176,000
117,000
67% C,
CR

Getty Oil
El Dorado, KS
32,300
29,200
31,800
37,00(1
24,600
G.
CR


(lull Oil Corporation
Alliance, LA
167,000
151,000
164,000
199,000
133,000
c,
CR,
TD


Philadelphia, PA
92,000
83,200
90,400
93,700
62,500
c,
CR,
TD


Port Arthur, TX
186,000
169,000
9/.7UO
108,000
72,000
c,
CR,
PC

Kerr-McCee Corp.
Corpus ChrLsti, TX
39,800
36,000







(Southweatern Oil & Kef. Co.)










Marathon Oil Co.
Texas City, TX
17,400
15,700
17,100
17,000
11,400
c,
CR


Mobil Oil Corp.
Beaumont, TX
149,000
135,000
14 7.000
170,000
114,000
CR,
, PG


Hoiumiito Co.
Chocolate Bayou, TX
211,000
191,000
208,000
213,000
142,000
c.
CK,
TD,
PG
Pbnu^oJ.1 Lnltud, Inc.
Shreveport, LA
87,000
78,700
36,600
42,600
28,400
PU



(Atlas Processing)










Phillips Petrol. Co.
Sweeny, TX
24,900
22,500
24,400
62,500
41,700
c,
CR



Guayama, Puerto Rico
273,000
247,000
269,000
312,000
208,000
PC,
CR,
, TD

OuIntana-Howe11
Corpus Chrlsti, TX
224,000
202,000
17,100


CR

-------
Table 2.2 Producers and Production, 1975-1979 (continued)
if®ccd Production^ (kkg)
Production PrDt'entjefl

Company
Local 1 mi
1979
1978
1977
1976
1975
and 1
Shell Oil Co.

DL'tir Park, TX
298,1)00
270,000
220,000
213,000
142,000
C, CK,
TG


Odessa, TX
29,800
27,000
29,300
17,000
11,400
CR, TD



Wood River, II.
112,000
101,000
1 10,000
114,000
76,000
CR, LO

Standard Oil.
Co, nf. Calif.
Segundo, CA
57,200
51,700
56,200
05,300
4 3, f>00
C, CR

Standard Oil
Co. (Ind.) (AMOCO)
Texas CiLy, TX
21J,000
191,000
208,000

161,000
C, CR

Standard Oil
Co. (Olilo)
Marcus Hook, PA



22,700
15,200


(D.P. Oil Co.
)








Sim 011 Co.

Marcuu Hook, PA
72JIKJ
65,200
70,800
42,600
28,400
CR, Tr



Corpus Clirit-.l'L, TX
94,500
85,400
92,800
99,400
66,300
C, CR,
TD


Tulsa, OK
59,700
54,000
58,600
68,200
45,500
CR, TP



Toledo, Oil
184,000
166,000
120,000


CK, TD

T^'nnfro, Inc.

Chalu.ette, LA
24,900
22,500
24.400
28,400
18,900
CR, L0

Texaco, Inc.

Port Arthur, TX
112,000
101,000
110,000
128,000
85,300
/ 3% c,
CR


Westville, NJ
87,000
78,700
85,500
99,400
66,300
PC, CR

Union Carbitlc
Corp.
Tnft, I .A
174,000
157,000
171,000
199,000
133,000
C, PC

Union Oil Co.
of Calif.
Lcmont, IL
42,300
38,200
41,500
54,000
36,000
CR , 1.0

Union Oil-American Tetrofina
Beaumont, IX
54,700
49,500
53,700
54,000
3b, 000
'.OX c,
TD
Union Pacific
: Corp.
Corpus Chriati, TX
24,900
22,500
24,400
28,400
18,900
C, CR

(CliaiupJin L'etroltKiiQ Co.)
TOTAL U3ITC PRODUCTION	5,430,0003 4,780,000 4,570,000 4,540,000 3,190,000
1.	Sources: A.D. Little, Inc., 1977; SKI, 1977; VerBar, 1979; Neufeld fit al. , 1978.
2.	Key: C- capcive use, PO partially captive, CR- catalytic reformation, TD- toluene duiilkylation,
TP- toluene disproportionation, PC- pyrolysls gaaoline, L0- light oil.
Derived trora plant capacities and USTTC production totals as described in Section 2.1.2.
'i. iiatimated by extrapolating US1TC data for the nonths January through July, L979,

-------
Estimated
production
Total benzene production by
petroleum refineries for year
(USITC)
Capacity of
X individual
Total U.S. plant capacity for
year (SRI), minus capacity of
plants not listed by USITC as
producing benzene that year
plant (SRI)
The following points were considered in the application of the
formula to derive benzene production figures:
1.	The USITC production figures are in gallons; therefore, a con-
version factor of 3.33 x 10" 3 kkg/gal was applied to obtain
production in kkg.
2.	It was assumed that an individual plant's production was propor-
tional to its capacity.
3.	Estimates for 1979 were based on USITC data from January to
July which were extrapolated for the remainder of the year.
4.	Plant capacities for 197-5-1976 were assumed to be equal to those
for 1976 listed by Versar (1979).
2.1.3 Production by Catalytic Reformation
Catalytic reformation is the most commonly used of the four methods
for producing benzene from petroleum. Of the 46 refineries listed as
producers of benzene in 1978 (Table 2.2), 37 were reported to have the
capacity to produce benzene by catalytic reformation.
The catalytic reformation method is composed of two distinct pro-
cesses: reforming and separation. The purpose of the process is to
increase the quantity of aromatic component of the selected crude
petroleum fraction, usually a naphtha cut, by reforming the molecular
structure of hydrocarbons or rearranging them. Appendix B-2 lists the
types of feedstocks used in the catalytic reformation method of benzene
production. The main chemical reactions involved are listed in Table
2.3. These reforming chemical reactions are accelerated by noble metal
catalysts such as rhenium and platinum on a bed of silica and alumina
in hydrogen under normal atmospheric to moderate pressures (Considine
1974; Industrial Sources 1980). A compilation of the industrial reform-
ing processes and flow diagram are presented in Appendix B.
2-6

-------
Table 2.3 Chemical Reactions in Reforming Hydrocarbons in
a Naphtha Cut to Form Benzene
V

Hydrocarbon

Component
Chemical Reaction
Reformed
Dehydrogenation
Naphthenes
Dehydrocyclizat ion
Paraffins
Isomerization
Paraffins
Hydrocracking
Paraffins
heavy paraffins


(Source: Adapted from Considine (1974))
The purpose of the separation process is two-fold: separation of
the aromatic from nonaromatic components, and fractionation of the aro-
matic mixture' into specific components. The five commercial aromatic
recovery methods, the feedstocks from which the aromatics are recovered,
and their aromatic content are presented in Table 2.4. A detailed
description of these processes is included in Appendix B-3.
Table 2.4 Methods of Aromatic Recovery from Petroleum''"



Percent Aromatic


Content for Pro-
Process
Feedstock
cess Efficiency
Liquid-liquid extraction
Catalytic
20-65

reformate

Extractive distillation
Pyrolysis
65-90

gasoline

Azeotropic distillation
Pyrolysis
Above 90%

gasoline

Absorption on solids
Coke oven
1

gas

Crystallization by
Unknown
Special cases
freezing

for benzene

1. Adapted from Weissermel and Arpe (1978).
2-7

-------
The liquid-liquid extraction method is the most frequently employed
method. A table of the liquid-liquid extraction processes and solvents
is also included in Appendix B. The liquid-liquid extraction processes
used most often are the Udex and Sulfolane processes (Industrial Sources
2.1.3.1 Amounts Produced by Catalytic Reformation
Total capacity for benzene production by petroleum refineries are
calculated as 7,080,000 kkg during 1978. Of this amount 3,500,000 kkg
were estimated to be for the catalytic reformation process (SRI 1977;
Neufeld et al. 1978). Of the total petroleum-derived benzene production
(as opposed to capacity) of 4,780,000 kkg (USITC), 2,360,000 kkg were
attributed to production by catalytic reformation. This value was cal-
culated by assuming that 1978 production was proportional to capacity as
Catalytic reformation capacity of plants is presented in Table 2.2.
2.1.3.2 Releases Due to Catalytic Reformation
The two steps in catalytic reformation, reforming and separation,
will be examined individually in an effort to elucidate the quantities
and types of benzene releases for this method of benzene production.
Within the reformation step, there are seven major and a few minor
proprietary processes in use today. The "platforming" process is in
greatest commercial use, with nore than 500 units in operation (Hydrocar-
bon Processing 1978). Assuming that the relative proportions of these
reforming proprietary processes are the same for benzene production as
they are for the catalytic reforming industry, the "platforming" process
is the most widely used process. Therefore, the following sources of
releases are based on the platforming process; releases for this process
will be assumed to be typical of benzene releases from reforming in the
benzene industry. Appendix B-4 contains flow diagrams and details of
the "platforming" process. These are three production process steps
during which benzene may be released: catalyst regeneration and replace-
ment; hydrogen gas regeneration; and extraction of the light gases. For
more detailed information on these releases refer to Appendix B.
A review of the pertinent literature and contacts with industry did
not reveal any release factors, nor were data obtained to calculate
releases for these processes. Contacts with industry did indicate that
benzene releases from these processes would probably be in the form of
vapors with concentrations in the parts-per-million range. As a result
of these discussions, JRB estimates that two aspects of these processes
deserve further investigation: light gases collected at the separator
may contain greater benzene concentrations, and catalyst regeneration
at the vendor's site may result in possible worker exposure to benzene.
1980) .
follows:
' Total i
Production
1978
Production,
Catalytic Reformation
1978
Total Benzene Capacity
2-3

-------
Of the five aromatic recovery methods, liquid-liquid extraction is
the method used to recover aromatics from reformate. There are nine
proprietary processes for liquid-liquid extraction in use today. The
"Sulfolane" and "Udex" processes are the major processes in use, as
indicated by numerous industrial contacts. Refer to Appendix 3-3 for
details on the types of liquid-liquid extraction processes and flow
diagrams. The following sources of releases are for the Sulfolane and
Udex processes, assumed to be representative of benzene releases for
the extraction process.
Benzene releases may be associated with certain steps in or products
resulting from the aromatic extraction processes: solvent regeneration
or reconstitution, raffinate wash water, and raffinate. For more detailed
information on these releases refer to Appendix B-3.
A review of the literature and industry contacts did not reveal any
release factors nor were data available to calculate releases from all
these sources. However, the reviewed literature did indicate that ben-
zene recoveries of 99.9 percent are not unusual for the Sulfolane process
(Hydrocarbon Processing 1978). The remaining 0.1 percent of benzene is
estimated by JRB to be found in one - or, more likely, a combination - of
the following: raffinate, raffinate wash water, or the remaining solvent.
Assuming the other extraction processes have similar efficiencies, the
amount of benzene that was released to these'sources was calculated as
follows:
Due to the great variability of the extraction process, refinery
operations, and market demand, we estimated the accuracy of the quan-
tity of benzene not covered in the extraction process to be +500%, -50%.
This benzene would be distributed among raffinate, raffinate wash
water, and solvent. The estimated distribution of benzene released in
the solvent extraction process is presented in Table 2.5 below.
The reviewed literature revealed two estimates for the quantity
of benzene released during the catalytic reformation process. These
estimates are presented in Table 2.6. The sources that provided these
estimates did not state any uncertainties nor was information given
from which uncertainties could be calculated. Refer to Section 2.1.7
for general estimates of benzene releases from petroleum-derived ben-
zene production.
2.1.4 Production of Benzene by Dealkylatlon
The method that produces the second largest quantity of benzene
from petroleum is dealkylation of toluene and higher alkylaroniatics.
Of the 43 refineries believed to produce benzene in 1978 for which we
Benzene Produced
by Catalytic
Reformation, 1978
Maximum Possible
Releases During
Extraction
(2,360,000 kkg)
(0.001)
2,360 kkg
2-9

-------
Table 2.5 Estimated distribution of Benzene Not Recovered
by the Extraction Process

Benzene
Containing
Liquid
Unrecovered
Benzene
(?)
(kkg)
Disposition of
Liquid
Solvent
2
50
Recycled, rarely
disposed
Raffinate Wash
Water
60
1400
Recycled, eventually
sent to refinery
effluent treatment
facility
Raffinate
38
900
A.	Blended into
gasoline or
j et fuel
B.	Used for
olefin production
C.	Unknown

2-10

-------
Table 2.6 Benzene Releases Due to the Production of Benzene by the Catalytic Reformation Method




Source of
Estimate
Release
Factor
Background Information
Release Calculations
Walker 1976
1 percent of the
benzene produced
by catalytic refor-
mation
Walker estimated that
this is a maximum factor.
(2,360,000 klcg benzene
produced in 1978 by cata-
lytic reformation) x
(1 x 10 klcg/kkg) =
20,000 kkg benzene
released (maximum)
Ochner et al.
1979
67,000 kg/yr/
refinery
The estimate by T. W.
Hughes, Monsanto Research
Corporation, Dayton, Ohio.
An estimate of the total
quantity of benzene
releases from catalytic
reformation process in
1976 was divided by the
number of facilities pro-
ducing benzene by the
catalytic reformation
process to arrive at a
release factor.
(67 kkg/yr/refinery) x
37 refineries using the
catalytic reformation =
2,500 kkg of benzene
released.
.

-------
have data on production methods, 15 were reported to have the capacity
to produce benzene by dealkylation (Table 2.2).
DeaIkylation normally occurs in a hydrogen environment; therefore,
the method is called hydrodealkylation. There are two commercial pro-
cesses for hydrodealkylation: catalytic and thermal. Refer to Appendix
B-5 for the proprietary names and descriptions of these processes. Fre-
quency of use of the processes is about equal, and process steps are very
similar (Kirk-Othmer 1976). In both, toluene is heated and then charged
to a reactor in the presence of excess hydrogen. Toluene reacts with the
hydrogen to produce benzene and methane gas. The reaction product is
separated, stabilized, and distilled to recover benzene. The major dif-
ferences between the two processes are that toluene is heated to a
higher temperature in the thermal process, and a catalyst is present in
the catalytic process (Kirk-Othmer 1976).
In a newer method, steam dealkylation, toluene is reacted with steam
to produce benzene, carbon monoxide, carbon dioxide, and hydrogen. The
advantage is that hydrogen is produced rather than consumed (Kirk-Othmer
1976).
A list of feedstocks and the chemical reactions in the production
of benzene by the dealkylation methods is presented in Table 2.7.
Table 2.7 Feedstock and Chemical Reactions for the Dealkylation
Method of Benzene Production

Feedstock^"
Frequency of Use
2
Chemical Reaction
92-95% Toluene
Usual feedstock
Demethylation
85-90% Toluene
Less frequently
Demethylation,

used
Dealkylation
Longer chain alkyl
Much less than the
Combination of de-
chains: heavy
first two feed-
methylation and
catalytic refor-
stocks
dealkylation
mates, catalytic


oils



1.	SRI 1977.
2.	PEDCo 1977.
The amount of benzene produced by toluene dealkylation varies depend-
ing upon the demand for benzene and relative prices of benzene and toluene.
Due to fluctuating market conditions and high cost of manufactured feed-
stock (compared to the other benzene feedstocks) the dealkylation method is
generally used by petrochemical refinery complexes with excess toluene
not needed for gasoline blending. Further, the benzene produced in this
way is generally used for in-house consumption (Industrial Sources 1980).
2-12

-------
As a result of the decrease in lead levels in gasoline, toluene is
now blended in greater quantities into gasoline to increase the octane
rating. Because of the sharp increase in demand for unleaded gasoline,
JRB estimates that the quantity of benzene produced by hydrodealkyla-
tion of toluene will significantly decrease.
2.1.4.1	Amounts of Benzene Produced by Dealkylation
Estimated capacity for benzene production by toluene dealkylation
was 1,920,000 kkg for 1978 (SRI 1977; Neufeld et al. 1978). Production
was estimated at 1,300,000 kkg; this estimate was derived from USITC
production data for petroleum-derived benzene using the formula in
Section 2.1.3.1.
Information on refinery complexes have toluene dealkylation capacity
is presented in Table 2.2.
2.1.4.2	Releases Due to the Dealkylation Method of Benzene Production
The two different processes for toluene dealkylation produce dif-
ferent quantities of releases. Table 2.8 presents a list of the poten-
tial releases from the dealkylation method.
Ochner et al. (1976) reported a release factor of 88 kkg of benzene
per year per producer for the dealkylation method. The release factor
was derived from an estimation of the total benzene released as a result
of the alkylation method for 1976. This estimate was made by private
communication with T. W. Hughes, Monsanto Research Corporation. The total
estimate was divided by the number of facilities producing benzene by the
dealkylation method to arrive at the release factor. The total releases
of benzene from the dealkylation method for 1978 are calculated below.
No uncertainties were given with the release factor nor were data pro-
vided from which uncertainties could be determined. However, JRB esti-
mated that the uncertainty would be very high (+500%, -200%) due to the
variation in processes, equipment, process flow, and quantities of ben-
zene produced by each of the 15 users of the dealkylation method. Refer
to Section 2.1.7 for general estimates of benzene releaes from petroleum-
derived benzene production.
2.1.5 Production of Benzene by Transalkylation and Disproportionation
Transalkylation and disproportionation of toluene is the method
that produces the third largest quantity of benzene, although ic ranks
last in number of plants using it. Of the 43 refineries thought to
produce benzene in 1978 for which we had data on production methods,
only three had the capacity to produce benzene by toluene dispropor-
tionation (Table 2.2).
(Users)
Benzene Released
from Dealkylation
1978
(88 kkg/yr) (15)
1300 kkg
2-13

-------
Table 2.3 Process Releases from the Dealkylation Method
Source
Form of Release
Separation of benzene and
methane
Distillation
Regeneration of catalyst
in the catalytic method
C02 and during dealkyla-
txon
Vapors contaminating methane
Vapors
Vapors probably in ppm con-
centrations which occur
every 2000-4000 hours
depending on severity of
operating conditions
Vapors in gases and steam
condensates
2-14

-------
The synthesis of benzene by this method is the result of a realkyl-
ation of alkylaromatics. This occurs by two types of reactions: dis-
proportionation and transalkylation. -An explanation of these reactions
is presented in the table below.
Table 2.9 Difference Between Disproportionation and Transalkylation
Reaction
.. . 	,
Explanation
Disproportionation
Conversion of alkylaromatics into
equal parts of higher and lower
alkylaromatics or, in some
instances, dealkylated aromatics.
Transalkylation
Transfer of alkyl groups from
higher to lower alkylated aro-
matics .

A description of the process, proprietary names, and a process flow
diagram are located in Appendix B.
9
The feedstock for this method is toluene and C aromatics. JRB
estimates that as the demand for toluene due to its use as a gasoline
component increases, the use of this method and the quantity produced
will decrease.
2.1.5.1	Amounts Produced by Transalkylation and Disproportionation
Estimated capacity for benzene production by toluene disproportiona-
tion was 180,000 kkg for 1978 (SRI 1977; Neufeld et al. 1978). The
actual production was estimated at 121,000 kkg, as calculated from USITC
data and capacity information as described in Section 2.1.3.1.
Information on plants having toluene disproportionation capacity is
presented in Table 2.2.
2.1.5.2	Releases of Benzene Due to the Transalkylation and Dispropor-
tionation Method
Benzene releases differ slightly for the three proprietary processes
for this method. Table 2.10 presents a general list of the process
releases from the transalkylation and disproportionation method. Ochner
et al. (1976) presented a release factor of 20 kkg of benzene per year
per producer by transalkylation and disproportionation. This estimate
was derived as described in Section 2.1.4.2. The total releases of
benzene from this method are calculated below.
2-15

-------
Table 2.10 Potential Sources of Benzene Releases from the
Transalkylation-Disproportionaticn Method

Process Source
Estimated Form of Release
Separation of benzene
and xylene
Regeneration of the
catalyst
Heavy hydrocarbons
that do not
break down
Liquid - contamination of xylene
Vapors - probably in concentrations
in the ppm range
Solid - may be contaminated with
benzene
2-16

-------
Benzene Release
from Transalkylation-
Disproportionation
Method, 1978
(20 kkg/yr) (3)	=	60 kkg
No uncertainty or data to compute an uncertainty were reported for the
release factor. JRB estimated the uncertainty to be +50%, -20% due to
the similarities of the proprietary processes and small number of users.
Refer to Section 2.1.7 for general estimates of benzene releases from
petroleum-derived benzene production.
2.1.6 Production of Benzene from Pyrolysis Gasoline
The smallest quantity of benzene from petroleum was produced by
this method. JRB estimated that as the demand for auto fuel increases
so will the quantity of benzene produced from pyrolysis gasoline. First,
benzene, toluene, and xylene may be produced as byproducts of auto fuel
produced from pyrolysis gasoline. Second, toluene demand will increase
due to its use as an auto fuel additive; the resulting decrease in avail-
ability or rise in cost will therefore limit toluene use as a benzene
feedstock for the dealkylation and transalkylation-disproportionation
methods.
Of the 43 refineries believed to produce benzene in 1978 for which
we also had data on production methods, 11 were reported to have the
capacity to produce benzene from pyrolysis gasoline.
Pyrolysis gasoline is a byproduct of the steam cracking of heavy
naphthas or gas oils in the production of ethylene. Refer to Appendix
B for a list of feedstocks. Pyrolysis gasoline has a high content of
unsaturated aliphatic and aromatic hydrocarbons that are used as feed-
stock in the production of aromatics and gasoline (Kirk-Othmer 1976).
There are several proprietary processes; two of these, IFP and Pyrotol,
are described accompanied by process flow diagrams in Appendix B.
2.1.6.1 Amounts of Benzene Produced from Pyrolysis Gasoline
Estimated capacity for benzene production from pyrolysis gasoline
was 1,320,000 kkg for 1978 (SRI 1977; Neufeld et al. 1978). Production
for 1978 was estimated at 925,000 kkg from USITC data as described in
Section 2.1.3.1.
Information on facilities with capacity for production from pyro-
lysis gasoline is presented in Table 2.2.
Table 2.11 lists the feedstocks and quantities of benzene produced
from them.
fRelease ^
I Factor J
I per User I
2-17

-------
Table 2.11 Pyrolysis Gasoline Feedstocks and Quantities of Benzene
Produced from Each Type
Ethylene Feedstocks
Estimated Benzene
Produced
Lower Paraffins
Ethane
Not an economical feedstock
45 kg of propane or
n-Butane produce 2.3 to 4.6 kg of
Propane
n-Butane
benzene
Heavier Hydrocarbons
Naphthas
Gas Oil
Condensates
45 kg of naphthas
gas oils, or condensates are esti-
mated to produce 6 to 11 kg of
benzene
(Source: SRI 1977; JRB-derived estimates from SRI data)
2.1.6.2 Releases Due to the Pyrolysis Gasoline Method of Benzene Pro-
The two proprietary processes for pyrolysis gasoline have different
environmental releases (Appendix B). Table 2,12 lists the potential
releases from the pyrolysis gasoline processes.
Ochner et al. (1976) reported a release factor of 60 kkg of benzene
per year per producer by the pyrolysis gasoline method. The release fac-
tor was obtained as described in Section 2.1.4.2. The total benzene
released for three plants in 1978 was 180 kkg. The release factor was
reported without estimates of uncertainties, nor were data available to
calculate uncertainties. JRB estimated that uncertainties would be high
(+300%, -100%) because of possible variation in the feedstock composition
and the number of plants using the process.
2.1.7 General Releases Due to Petroleumr-Derived Benzene Production
Total releases of benzene from the four petroleum production methods
were estimated to be 4,000 kkg for 1978; Table 2.13 lists those due to
each method. Other release factors based on a percentage of the total
production are given in Table 2.14. There is a wide range between these
estimates: 30 to 50,000 kkg/year. JRB estimated overall benzene
releases from petroleum production of benzene to be closer to the 4,000
kkg/yr figure than to the more extreme values in Table 2.14. This con-
clusion was based on the judgment that for economic reasons, all feasible
control methods would be implemented to prevent undue loss of a product.
This evaluation was qualitatively confirmed by several industrial contacts.
duct ion
2-18

-------
Table 2.12 Generalized List of Potential Benzene Releases from
Pyrolysis Gasoline Processes
r
Process Type^and
Release Source
Probable Form of Release
IFP

1. Gum
1. Nonoxidative removal of gums from
catalyst probably every 3 to 6
months. Solids and vapors probably
contain some benzene.
2. Catalyst
Regeneration
2. Oxidation of coke deposits on catalyst
every 9 to 12 months may release
benzene vapors in the ppm range.
3. Distillation
Process
3. Liquid contamination of condensates and
reaction products.
Pyrotol

1. Gum removal from
evaporator
1. Benzene in gums, probably in solid
waste
2. Besulfurization
2. Benzene contamination of sulfur
extracted from the feedstock,
probably in solid waste.
3. Clay treatment
process
3. Clay contains contaminants strained
from benzene; contaminants could
contain benzene which would be disposed
of as solid waste.

See Appendix B for process descriptions.
2-19

-------
Table 2.13 Summary of Estimated Benzene Releases for the Four Petroleum
Production Processes

Process
Estimated
Benzene Releases
(kkg)
Sect ion
Catalytic
reformation
2,500
2.1.3.2
Dealkylation
1,300
2.1.4.2
Transalkylation -
disproportionat ion
60
2.1.5.2
Pyrolysis Gasoline
180
2.1.6.2
TOTAL
4,000

(Source: Ochner et al. 1979)
A release factor for benzene releases to air was reported by PEDCo
(1977). This factor, 1.8 x 10-J kkg/kkg produced, was based on a Union
Carbide estimate for a single facility thought to be using the pyrolysis
gasoline production method. The factor was judged to be not credible in
magnitude and not applicable to refineries in general, and it was not used
further in this report.
-4
A release factor for water (Versar 1977) of 1.3 x 10 kkg/kkg pro-
duced, was based on an average of 0.22 percent of benzene lost to the
environment, as reported by an industrial survey. It was assumed that
6 percent of the total benzene released went to water. This factor
yielded an estimate of 620 kkg of benzene released to water.
In estimating the uncertainties of the releases to water during ben-
zene production, two factors were taken into account: the wide range for
industrial estimates of percentage of benzene lest to the environment
(these estimates differ by a factor of 730); and the allocation of 6 per-
cent of total losses to water. Based on these two factors, an uncertainty
of + a factor of 1,000 was assigned to the estimate of benzene releases to
water.
The solid wastes generated from benzene production include the
following types: solid, liquid-solid slurries, and sludges. The com-
ponents of the solid wastes that appear to come directly from the benzene
synthesis processes are acid and alkali sludges (Saxton and Markus-Kramer
1975).
The quantity of solid waste generated from benzene production was cal-
culated using data of Saxton and Markus-Kramer (1975), who calculated the
amount of solid was generated from benzene production in 1972. These
2-20

-------
Table 2.14
Summary of Che Estimated Overall Benzene Releases During Production
from Petroleum



1
Source of
Release Factor
Release Factor
Calculation of Benzene Releases
Benzene
Released
(kkg)
Walker 1976
1 percent of benzene
produced
A,780,000 lckg\
(17c) ( produced in )
\ 1978 j
50,000
Patterson
et al. 1.976
0.5 percent of benzene
produced
U, 780,000 kkg\
(0.52!) 1 produced in ] =
V 1978 J
20,000
Versar 1977
Industrial question-
naire suggested
relesases of 0.0006 to
0.44 percent of ben-
zene produced; average
of 0.22 percent
Low: (0.0006%) A, 780,000 kkg \
^produced in 1978J
High: (0.44%) (4,780,000)
Average: (0.22%) (4,780,000) =
30 Low
21,000 High
11,000 Average

-------
figures are for benzene production for all processes: the petroleum-
based processes discussed in this section and the coal-based production
treated in Section 2.2. From their data, a factor for generation of
solid wastes from benzene production was derived.
I Solid Waste from X
[Benzene Production,]
\	1972	J
/Benzene Produced A
V	1972	J
(12,508 kkg)
(4,170,492 kkg)
Solid Waste
per kkg of
Benzene Produced
0.003
JRB estimates that 1 percent of the solid waste is benzene. Recovery
of this concentration of benzene would be uneconomical; therefore, its
presence in solid waste is plausible. This estimate is also consistent
with our understanding of the industry and with comments made by indus-
trial officials contacted.
Benzene releases to solids as a result of benzene production from
petroleum and coal tar are as follows:
( Benzene X /Solid Waste
Produced, I J Generation
,1978 J \ Fact
:or
Percent X
Benzene in J
Solid Waste/
Benzene
Released to
Solid Waste
Petroleum
(4,710,000 kkg)(0.003)(0.01)	=	141 kkg
Coal Tar
(252,000 kkg)(0.003)(0.01)	=	8 kkg
JRB estimated that the solid wastes generated from benzene produc-
tion would be handled in the same manner as those from refineries, which
are sent to a land disposal site. For more information on refining
waste disposal refer to Section 3.1.
2.1.8 Releases of Benzene Due to Transportation, Loading, and Storage
Associated with Production of Petroleum
In addition to benzene releases from the four methods of producing
benzene from petroleum, releases also occur during the flow of benzene
from the producer to users. These releases may occur during three trans-
port processes: transportation, loading, and storage. The environmental
releases of benzene are almost all to air (99 percent), with the remainder
going to water as a result of barge transportation of benzene.
2-22

-------
2.1.8.1 Sources of Benzene Releases During Storage
Benzene is stored in one of the three types of floating-roof storage
tanks: pan, pontoon, and double-deck. The pontoon and double-deck tanks
were designed to alleviate two problems with the pan type:
• Extreme tilting of the pan may cause the roof to buckle or sink,
resulting in
-------
Table 2.15 Benzene Release Factors and Calculations for Storage Releases

Source
Release Factors
Derivation
Based on
PElXJo 1977
Storage: standing
8 x 10 ® kkg/gal of
benzeue consumed
30 =
4.6 x 10 ^ =
0.75 =
2.3 x 106 =
(30)(4.6 x 10"3)
(0.75)(2.3 x 10b)
retention time in days (estimated)
tank emission factor in kkg/tank/day
percent of tank filled (estimated)
size of average storage tank (gal)
L'EnCo 19/7
Withdrawal
3.4 x 10 ^ kkg/gal of
benzene consumed
7.4 x 10~6 =
2,2 x 103 -
(7.4 x 10~6)
(2.2 x 10^)
withdrawal loss in lbs/gal
lbs/kkg
SRI 1978
Uncontrolled Storage
3.0 x 10~6 kkg/gal of
benzene stored
Internal Floating Roof
coupled with vapor re-
covery system
0.3 x 10 ^ kkg/gal
SRI included
from certain
these estimates when calculating releases
refineries as presented in Figure 3.1.
-------
Table 2.16 Benzene Release factors and Calculations
for Leading Operations
(Source: Based on Dunavent 1978)

Release Factor
Derivation
Rundown Tank Losses
- 8
Standing: 6.4 x 10 kkg/gal
Withdrawal: 5.8 x 10 ^ kkg/gal
Converted from estimated release for a 40 x 10^ gal capacity
petroleum-derived benzene plant: working at capacity.
5»600 lbs emitted . .^6
llz X iOJ lbs/kkg • x 10 SBl
5,100 lbs 6
2.2 x 10J lbs/kkg - C * 10 gal
Rail/Truck Loading Tank Losses
Standing: 1.7 x 10 ^ kkg/gal
loaded
Withdrawal: 3.6 x 10*"^ kkg/gal
loadad
Barge Loading Tank Losses
Standing; 4.6 x 10 ^ kkg/gal
loaded
Withdrawal: 3.0 x 10 ® kkg/gal
loaded
Converted from estimated releases for a 40 x 10^ gal capacity
petroleum-derived benzene plant working at capacity; 28 x 10®
gal of this are handled through rail/truck loading tanks
(14 x 106 gal of this later placed in pipeline); the remaining
12 x 10^ gal are handled through barge loading tanks.
llfl loi * 28 x 10^ gal
2.2 x 10? • 12 X 10
2.2 x 10J ' 12 x 10
Loading Losses
Railtanker: 1.3 x 10"6 kkg/g.al
loaded
truck: 1.3 x 10 ^ kkg/gal
loaded
Bargei 1.1 * 10*6 kkg/gal
loaded
Assume 10 x 10 6 gal loaded la rail canker; 4 x 106 gal loadaa
In truck Cankers; and 12 x 10° loaded in barge*.
"zTio' '• 10 x 10'
11.600 . fi
2.2 x 10J T A x 10 gals
; 12 * 106 S«l.
2-25
-------
Loading losses are produced as liquid benzene is pumped into the
carrier and vapors present (either from previous loads or currently
generated) are displaced. Release factors for rail, tankers, trucks,
and barges are also presented in Table 2.16 (Dunavent 1978).
Before applying these release factors, it was necessary to determine
the quantity of benzene that was not captively used in production of
benzene derivatives. First the capacity for noncaptive production was
derived:
Total Capacity.j _ fCaptive A Noncaptive
1978 J \^Capacityy Capacity
(2,125 x 106 gal) - (987 x 106 gal) = 1,138 x 106 gal
These figures are based on data from USITC, Arthur D. Little, Inc. (1977),
and SRI (1977). For benzene producers listed as partial captive consumers,
production was estimated to be 50 percent captive.
By applying this information to the total benzene production by
refineries (including extraction of light oil), the noncaptively con-
sumed benzene for 1978 was calculated.
•Benzene
(Refinery Production, 1978) m Noncaptively
Consumed, 1978
(21125 x 10b gal) (4'780 * 1()3 kkg) " 2'560 x ^ kkg
This value was used in combination with the release factors for
loading operations in Table 2.16 to calculate the total benzene release
due to loading operations. The following assumptions were necessary for
these calculations:
• All the noncaptive benzene passes through rundown tanks.
• Fifty percent of the noncaptive benzene is loaded into railroad
tanks or trucks; the remaining 50 percent is loaded in barges.
Captive \
Capacity/
Total \
Capacity/
2-26
-------
These calculations yielded the following release estimates:
From rundown tanks:
Standing:
Withdrawal:
49 kkg
45 kkg
From railroad/truck loading tanks:
Standing:
Withdrawal:
64 kkg
14 kkg
Total Benzene Releases
Due to Loading Operations:
1,300 kkg
From barge loading tanks:
Standing:
Withdrawal:
176 kkg
12 kkg
From loading losses to:
Railcars/trucks: 5
500 kkg
423 kkg
Barges:
No independent criteria were available for determining uncertainty ranges
of these estimates.
2.1.8.3 Releases During Transit
Release factors for releases during transit are summarized in Table
2.17. The PEDCo factor assumes equal distribution between rail/truck
and marine transit, and does not include releases due to loading and
unloading. Applying this factor to the amount of benzene not captively
used in 1978 (2,560 x 10^ gallons) yields an estimate of 270 kkg of ben-
zene lost due to transit.
The SRI factors were derived for specific modes of conveyance.
It is not known whether these factors include releases due to loading
and unloading operations. In applying these factors we assumed
that 50 percent of transport was by rail or truck and 50 percent by
barge.
3
Releases from noncaptive benzene (2,560 x 10 kkg) calculated from
these factors were as follows:
From transit by rail and truck: 690 kkg
From transit by barge: 290 kkg
No independent criteria were available with which to judge the uncer-
tainty ranges of these estimates.
980 kkg
2-27
-------
Table 2.17 Benzene Releases and Calculations for Transportation
Source
Factors
(kkg/gal)
Remarks
Based on
PEDCo 1977
SRT 1978
Transit
3.6 x 10~7
Uncontrolled
Conditions
Inland Barge
0.76 x 10"6
Tank Truck
1.8 x 10"6
Rail Tanker
1.8 x 10"6
Transport time 1 week
Conveyance: 50 percent truck/rail tankers, and
50 percent barge
Losses from loading/unloading are excluded from
factor
Not known whether factors include losses from
loading/unloading
-------
2.1.8.4 Total Releases Due to Transportation, Loading, and Storage
The sum of estimated emissions for transport, loading, and storage
operations for petroleum-derived benzene was:
Storage A + fLoading ] + [ Transport^ = Total
Releases! I Releases/ I Releases J
(105 - 4,900 kkg) + (1,300 kkg) + (980 kkg) = 2,400 - 7,200 kkg
Since the release factors were predominantly concerned with evapora-
tion losses, the benzene releases of 2,400 to 7,200 kkg is considered a
loss to air. This range of releases is intended to be neither a statis-
tical range nor a set of error limits. It was not possible to estimate
the uncertainties of the release factors used; therefore, the uncertain-
ties of the release estimates could not be determined.
2.2 BENZENE PRODUCTION FROM COAL
2.2.1 SuTmna ry
Figure 2.2 shows the production and location of producers of benzene
from coal. Company names and locations were compiled from information
reported by Versar (1979) and Neufeld et al. (1978). Estimated produc-
tion for the years 1975 to 1979 was calculated using the following
formula:
(Total U.S. Production,j f Plant j Plant Production
Coal-Derived Benzene J ^Capacity/ _ of Benzene
(Total U.S. Capacity) from Coal
In calculating the production of benzene from coal for the years
1975 through 1979, the production figures used were obtained from USITC,
and capacity information was taken from Versar (1979), SRI (1977), and
Neufeld et al. (1978). Production for 1979 was based on USITC data for
January through July, and extrapolated to cover the whole year. Plant
capacities for 1975 were assumed to be the same as those for 1977,
reported by SRI (1977) and Neufeld et al. (1978).
2.2.2 The Process
Benzene is produced as a byproduct of the carbonization of coal to
coke. Coal is heated in an oven in the absence of air driving off the
volatile gases. These hot gases are collected overhead and shocked-
cooled with a flushing liquor, which results in the removal of a large
portion of the tars and inorganic salts. The gases are further processed
to remove additional tars and ammonia. The gas is cooled once more with
water, then scrubbed with a high-boiling absorbent petroleum oil in a
tall column. The wash oil removes the light oil containing benzene,
toluene, xylene, etc., from the gas, and the mixture of wash and light
oils is separated by steam distillation. The crude light oil consists
of 55 to 70 percent benzene by volume (Arthur D. Little, Inc. 1977).
The yield of light oil from coke ovens producing blast furnace coke is
3 to 4 gallons per ton of coal carbonized (PEDCo 1977).
2-29
-------
LOCATIONS
Hot locatad: Geneva, t|t.
Clairton, Pa,
P30DUCTICH OF BEKZENE FROM COAL
Coal-d«rlv»d Betuene Producers
Coapanv Location
2
g«laated Production (kkg)
flmt Capactticm Baed
in £i
iinat iooa: 10^ ga3?
1979
1978
1977
1976
Armco Stwil Corp. KLddletoun, OH
Bethlehaa Staal Corp. Bethlehem, PA
Lackawanna, NT
Sparrows Point, HD
Mead Corporation Chattanooga, "ni
Woodward, AL
C.T. & I, Steel Corp. Pueblo, CO
Iocerlake, inc.
Tolcdo, OH
Jones & Laughlin Allquippa, FA
Steel Corp. (LtV Cor?)
Hortbveat Industries, toe Star, H
Inc. (Lcma Star Steel Carp)
B. S. Steel Corp.
Clstrtcm, FA
Ceacva, OT
Actnel total Production by 0. s. Coke
Own Operators (kkg) (OSITC)
6,500
a,7oo
5,?00
7,700
7,300
9,300
6,400
a,600
53,000 29,000 37,000
4,400
MQG
2,200
22,000
3,800
5,700
1.900
19,000
4,900
7,300
2 >00
24,000
6,900
9,200
17,000 18,000
32,000 33,000
0 0
0 0
6,400 6,900
2,100 2,300
21,000 23 , 000
1975 197S~?9 1977 137S-76
3 3 3
2,206 1,900 2,400 2.100 2,300
109,000 96,G00 110,000 96,000 104,000
8,703 7,70S 9,800 8,600 9,200
202,397 178,062 215,021 201,169 216,617
1. Sources: Versar, 1979; Ueufeld at al., 1978,
2. fstlaataa for Individual plants baaed on capacity
3. Source*: V.rwrr, 1979; Stl, 1977; Heufeld et *1;
estimates. Sea section 2.2.2.
1978,
15
50
4
93
15
45
4
88
15
0
0
3
1
10
45
4
94
Figure 2.2 Coal-Derived Benzene Producers
2.-30
-------
Another source of light oil is coal tar. Coal tar can be distilled
to yield a light oil fraction which is usually combined with the light
oil from coal gas before it is refined to produce benzene (PEDCo 1977).
Light oil produced is either refined on-site or is sold. Several petro-
leum producers refine this coal-derived light oil (SRI 1977; Arthur D.
Little, Inc. 1977).
The light oil is refined by various processes that result in separa-
tion into benzene, toluene, xylene, and residue fractions. Benzene
recovered from coke oven gas typically amounts to 1.85 gallons per ton
of coal carbonized (PEDCo 1977).
A schematic diagram summarizing benzene production from coal is pre-
sented in Appendix B.
2.2.2.1 Amount Produced
In 1S78, 178,000 kkg of coal-derived benzene were produced, according
to USITC. This represented 4 percent of total benzene production.
2.2.2.2 Releases During Coal-Derived Benzene Production
Possible sources of release during production of benzene from coal
are presented in Table 2.18. No release factors or data from which
release factors could be calculated were found in the literature for the
production of benzene from coal. Therefore, no benzene releases attri-
buted to benzene production from coal coking were calculated. Release
factors for the coal coking process in general were obtained from the
literature and are presented in Section 3.3 (Indirect Production of
Benzene). No release factors for transportation, loading, and storage
of coal-derived benzene were obtained from the literature, nor could
they be derived; consequently, no releases were calculated.
Table 2.13 Possible Sources of Benzene Releases from Coal Coking
Process Source
Estimated Type of Release
Shock cooling of flushing
liquor (removing tars and
inorganic salts)
Tar and anmonia removal
Second water cooling
Scrubbing process (washing
with higher boiling oils)
Wash oil/light oil separa-
tion over steam distillation
Shock liquor may contain benzene
tars; inorganic salts may be con-
taminated with benzene
Tar with ammonia may be contaminated
with benzene
Water may contain benzene
Petroleum oil contains benzene
Wash oil contains residual benzene;
steam condensates contain benzene
Light oil separation
Light oil contains residual benzene
2-31
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2.3 SUMMARY
The total amount of benzene produced in th.e United States in 1978,
according to USITC, was 4,960,000 kkg, of which 4,710,000 kkg were
petroleum-derived and 252,000 kkg were coal-derived. For further break-
down by process refer to Table 2.19.
The total estimated releases from petroleum-derived benzene are
between 6,424 and 11,219 kkg. Refer to Table 2.20 for a breakdown of
these releases.
The amounts of releases that can be specifically attributed to
coal-derived benzene are not known. Releases from this source are
Included in releases from coke ovens that are presented in Section 3.2.
2-32
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Table 2.19 Total Renzer.e Produc&d in the
United States During 1978

Feedstock
Derivation
Processes
Quantity of
Benzene Produced
Der Process (kkg)
Petroleum
Catalytic reformation
2,360,000

Dealkylation
1,300,000

Disproportionation-Transalkyl-
at ion
121,000

Pyrolysis Gasoline
925,000

Total, Petroleum
4,710,000
Coal
Coke oven
178,000

Extraction of purchased light
oil and unnamed methods
74,000

Total, Coal
252,000

Total, Both. Sources
4,960,000
2-33
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Table 2,20 Total Benzene. Releases Due to Petroleum-Derived
Benzene Production in 1978

Source of Release
Benzene
Releases
(kkg)
Production Methods