United Stares
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Research Triangle Park NC 27711
EPA-600/7-79-184
August 1979
Applicability of
Coke Plant Control
Technologies to
Coal Conversion

Interagency
Energy/Environment
R&D Program Report

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                 RESEARCH REPORTING SERIES


Research reports of the Office of Research and Development, U.S. Environmental
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                                  EPA-600/7-79-184

                                         August 1979
     Applicability of Coke
Plant Control Technologies
      to Coal Conversion
                    by
        S.M. Hossain, P.P. Ciiione, A.B. Cherry, and
               W.J. Wasylenko, Jr.

                 Catalytic, Inc.
               1500 Market Street
          Philadelphia, Pennsylvania 19102
             Contract No. 68-02-2167
                  Task No. 10
           Program Element No. EHE623A
         EPA Project Officer: Robert A. McAllister

       Industrial Environmental Research Laboratory
         Office of Energy, Minerals, and Industry
          Research Triangle Park. NC 27711
                 Prepared for

       U.S. ENVIRONMENTAL PROTECTION AGENCY
          Office of Research and Development
              Washington, DC 20460

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                                ACKNOWLEDGMENTS



     Catalytic, Inc. expresses grateful appreciation to the following

individuals and organizations for their contributions during this study:


     William J. Rhodes,.        Project Officer, EPA, IERL/RTP

     Robert A. McAllister,     Senior Chemical Engineer, EPA, IERL/RTP

     Norman Plaks,             Chief, Metallurgical Processes Branch,
                               Industrial Processes Div., EPA, IERL/RTP

     James P. Templin,         Foundry Coke Consultant

     Earle F. Young, Jr.,      Director, Environmental Affairs,
                               American Iron & Steel Institute

     Houdry Division of Air Products & Chemicals, Inc.

     Philadelphia Coke Co., Inc.
                                     ii

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                                    ABSTRACT

     Since there appear to be many similarities in the product, byproduct and
wastestream characteristics between the coke oven and coal conversion processes,
Catalytic, Inc. has been directed to conduct this study to review coke oven
processes and control technologies and to assess their applicability to the
coal conversion (synfuels) industry.
     Most of the major coke oven and coal conversion processes have been
considered, with special emphasis on:  Lurgi, Koppers-Totzek, SRC-I, COED,
Synthane and Byproduct coke oven processes.  Detailed material balances are
given for commercial size Byproduct coke oven and SRC-1 processes.  Comparisons
of the process and waste stream characteristics from the Byproduct coke oven
process with selected gasification and liquefaction processes have been made;
and recommendations regarding control technologies are suggested for air,
water and solid wastes.  An extensive review of coke oven control technology
was made.  State and Federal regulations concerning the disposal and treatment
of coke oven wastes are presented along with a brief assessment of health
effects attributed to the coke oven emissions.
     The results of the study indicate that a number of coke oven control
technologies are applicable to coal conversion systems, especially those
dealing with desulfurization, fugitive emissions, byproduct recovery/upgrading
and wastewater treatment.  Byproduct upgrading and fugitive emission control
technologies might be readily transferrable to analogous coal conversion
applications.  Desulfurization and wastewater treatment technologies, however,
could not be readily transferrable to those applications where significant
differences exist in the composition, temperature and pressure of the two
categories of process/waste streams.  In these cases, laboratory or pilot
plant scale tests will be required with actual coal conversion wastes to
determine the design bases and the treatability variations between the coal
conversion and the comparable coke oven streams.
                                       iii

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                                CONTENTS
                                                                      Page
Acknowledgments.	ii
Abstract	iii
Figures	vii
Tables	viii
1.   Summary and Conclusions	  ,  .  .  .    1
2.   Introduction	14
3.   Description of Coke Oven Processes	16
          Byproduct Coke Oven Process  	 .........  18
               General Process Features	18
               Coal Handling and Preparation	21
               Coke Oven Operation	,	21
               Recovery of Tar and Ammonia Liquor.	22
               Light Oil Refining	24
               Desulfurization of Coke Oven Gas	24
          Other Coke Oven and Related Processess	26
               Beehive Process	  •  26
               Low Temperature and Recent Processes	26
4.   Material Balance and Waste Characteristics of  Coke Oven Processes  33
          Byproduct Coke Oven Process  	 .....  33
               Typical Product/Byproduct Quantities	33
               Waste Characteristics	34
               Material Balance of a Typical Byproduct  Coke Oven  Plant  42
          Other Coke Oven Processes	58
               Beehive Process 	  58
               Low Temperature Processes 	  60

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                          CONTENTS  (continued)
                                                                     Page
5.    Coal Gasification Processes  and Their Waste  Characteristics  ...  61
          Coal Gasification Processes	61
               Acid Gas Removal and Sulfur Recovery	68
               Waste Characteristics and Comparisons  	  71
6.    Coal Liquefaction Processes  and Their Waste  Characteristics  ...  75
          Coal Liquefaction Processes	75
          SRC-I Process Material  Balances, ,..,..,  	  82
               Design Basis	82
               Overall Material Balance  	  82
               Waste Characteristics and Comparisons  	  92
7.    Coke Oven Control Technology and Its Applicability to
     Coal Conversion Processes 	  ,.,..,, 	  96
          Desulfurization of Coke Oven Gas	96
               Vacuum Carbonate Process	,	99
               Sulfiban Desulfurization Process  	  105
               Iron Oxide Process	110
               Stretford Sulfur Recovery Process 	  112
               Glaus Sulfur Recovery Process 	  119
          Wastewater Control Technology	124
               Ammonia Removal and Recovery	130
               Biological Oxidation	132
               Carbon Adsorption 	  137
               Oil Removal	138
               Phenol Removal and Recovery 	  139
          Solid Waste Disposal Methods	144
          Light Oil Upgrading Processes	144
               Litol Process  . .-	146
          Fugitive Emissions Control 	  152
               Charging Emission Control  	  153
               Pushing or Discharging Emission Control 	  157
               Quenching Emission Control	160

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                          CONTENTS (continued)
                                                                      Page
               Improvements in Operating Procedures and Maintenance    162
               Recent Control Technology Developments	163
8.   The Health Effects of Coke Oven Emissions	165
          Health Effects/Implications	165
               Chemicals Composition of Coke Oven Emissions and
               Their Health Implications	,	165
               Particle Size and Its Health Effects	165
               Synergisms.	 ,	172
          Basis of Sampling and Measurements	172
          Epidemiological Study Results. .......  	 175
          Summary of Study Findings  	 179
9.   Enviromental Requirements in the Coke Oven Industry	182
          Federal Regulations	182
               Air Pollution Control Standards ,,.,.., 	 182
               Water Pollution Standards 	 186
               EPA Water Quality Criteria	,	187
               Solid Waste Disposal Standards	188
          State Regulations	,  . . .	189
               Air Pollution Control Standards 	 189
               Water Pollution Control Standards . . ,	193
               Solid Waste Disposal Standards	193
Bibliography	194
Appendix A	,	199

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                                  FIGURES

Number                                                                  Page
3-1  Yields of carbonization products from upper banner seam coal ...    17
3-2  Simplified block flow diagram of a Byproduct Coke Oven Plant ...    20
3-3  Simplified block flow diagram of the Houndry LITOL Process ....    25
4-1  Detailed block flow diagram of a byproduct coke oven plant ....    45
5-1  Hypothetical coal gasification flow diagram	    64
5-2  Byproduct from Lurgi Plant	    66
6-1  Hypothetical coal liquefaction flow diagram	    78
6-2  Overall flow diagram:  20,000 TPD coal feed SRC-I process	    85
7-1  Two stage Vacuum Carbonate system flow diagram	101
7-2  Sulfiban desulfurization process	 .   107
7-3  Stretford sulfur recovery process flow diagram 	   115
7-4  Claus sulfur recovery process,  ............ 	   120
7-5  Coke plant wastewater treatment systems.  ... 	   126
7-6  Phosam-W ammonia recovery process.  ........ 	   133
7-7  Phenol removal by light oil —  caustic process 	   141
7-8  Phenol removal by high boiling  solvent process 	   143
7-9  Typical LITOL reactions	-,	147
7-10 Houndry's LITOL light oil upgrading process	148
                                     vli

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                                  TABLES
Number                                                                  Page
1-1   Coke Oven and Coal Conversion Stream Similarities ........    4
1-2   Comparison of Raw Gases	,,,,,	    5
1-3   Comparison of Process Wastewaters
1-4   Coke Plant Control Technologies and Their
      Applicability to Coal Conversion	   11
3-1   Other Coke Oven and Related Processes ,  ,  	 .......   27
3-2   Recent Coal Carbonization/Pyrolysis Processes ..... 	   30
4-1   Yields and Analyses of Products of By-Product Coke Oven Process .   35
4-2   Ammonia Liquor Blow-Down Composition  	   36
4-3   Final Cooler Water Slowdown Composition ........ 	   37
4-4   Light Oil Plant (Benzol) Process Wastewater Composition 	   38
4-5   Uncontrolled Air Emissions from Coke Ovens/Quenching Operations ,   41
4-6   Design Basis for A 5000 TPD Byproduct Coke Oven Plant	   43
4-7   Material Balance of A 5000 TPD Coke Oven Plant	   49
4-8   Summary of Air Emissions - 5000 TPD Byproduct Coke Oven Plant . .   54
4-9   Summary of Process Wastewater - 5000 TPD Byproduct Coke Oven Plant  55
4-10  Characteristics of Beehive Coke Plant Wastes	   59
5-1   Coal Gasification Processes Product/By-Product and
      Fuel System Similarities	   63
5-2   Products/Byproducts of Different Coal Gasification Processes. . .   67
5-3   Material Balance for Gas Liquor Treatment	,	   69
5-4   Acid Gas Removal Processes for Coal Gasification Systems	   70
5-5   Process Wastewater Analysis from Synthane Gasification of
      Various Coals 	   73
6-1   Coal Liquefaction Processes-Product/By-Product and Fuel
      System Similarities	   76
6-2   Operating Conditions of Three Leading Coal Liquefaction Processes   81
6-3   Design Basis for A 20,000 TPD Coal Feed  SRC-I Plant	   83
                                      viif

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                            TABLES (continued)
Number                                                                  Page
6-4   Overall Material Balance:   20,000 TPD SRC-I Plant	87
6-5   Summary of Gaseous Waste Streams (Before Treatment)	93
5-6   Summary of Liquid Waste Streams (Before Treatment) 	  95
7-1   Coke Oven Gas Desulfurization Processes	97
7-2   Vacuum Carbonate Requirements	103
7-3   Vacuum Carbonate Capital Costs 	 104
7-4   Sulfiban Operating Requirements	108
7-5   Sulfiban - Capital Costs 	 109
7-6   Stretford Desulfurization - Capital & Operating Costs	118
7-7   Typical Claus Plant Feed Composition for the Coke Industry .... 122
7-8   Characteristics of Byproduct Coke Plant Ammonia Liquor Wastewater. 129
7-9   Contaminant Removal Efficiency of Byproduct Coke Oven Plant
      Treatment Facilities 	 129
7-10  Design and Operating Conditions of Some Coke Plant
      Activated Sludge Systems 	 135
7-11  Typical Raw Light Oil Composition	145
7-12  Typical Litol Process Yields 	 150
7-13  Litol Process Operating Cost 	 151
7-14  Byproduct Coke Oven Fugitive Emissions Control 	 154
8-1   Partial List of Constituents of Coke Oven Emissions	166
8-2   Some Toxic Constituents of Coke Oven Emissions and
      Some of Their Toxic Properties 	 168
8-3   Particle Size Range and Bilogical Significance of Coke
      Oven Emissions	173
8-4   Summary of Exposures of Coke Oven Workers to Coke Oven Emissions . 174
8-5   Comparison of Benzo(a)pyrene Concentrations Measured at Coke
      Oven Batteries and at Other Selected Sites 	 176
8-6   Ambient BAP and BSD Data	177
8-7   Temperature Range of Carbonizing Chambers and Excess  of
      Lung Cancer Reported	177
8-8   Summary of Relative Risks of Death from Cancer Among  Coke
      Oven Workers	178
8-9   Estimated Effects of Coke Oven Emissions on U.S.  Population Under
      Weibull Probability Model Where "Hit Parameter" m=l and Adjustments
      for Total Population Rates Used	181
                                      ix

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                            TABLES (continued)


Number                                                                  Page

9-1   National Ambient Air Quality Standards 	  .... 185

9-2   Summary of State Air Pollution Control Regulations for the
      Control of H-S Emissions from Byproduct Coke Ovens	191

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                                    SECTION 1
                             SUMMARY AND CONCLUSIONS

     Coal was once the major source of organic chemicals (chiefly aromatics)
produced via the upgrading of coke oven byproducts.  In recent years, these
chemicals have been primarily supplied by processing petroleum and petro-
chemicals.  In the future, as the coal gasification and liquefaction (coal
conversion)  industry grows, it is expected that increasing amounts of these
chemicals will again be generated from coal.
     Since there appear to be many similarities in the product, byproduct and
was testream characteristics between the coke oven and coal conversion processes,
Catalytic, Inc. has been directed to conduct this study to review coke oven
processes and control technologies and to assess their applicability to the
coal conversion (synfuels) industry.
     Most of the process information, waste stream characteristics and control
technology data for the study were obtained from published literature.  Some
were generated by consultations with process vendors and coke oven plant
operators and representatives.
     Coke is produced by destructive distillation  (carbonization) of low
sulfur, bituminous coal in an oven or retort in the absence of air.  Coal used
in coke making is usually a blend of high-volatile coal with a 10 to 50 percent
low-volatile coal; the blend should not contain over 1.5 percent sulfur or 9
percent ash.  Approximately 16 percent of the bituminous coal mined in the
U.S. is converted to coke which is used principally in blast furnaces and
foundries.  More than 98 percent of the total U.S. coke is produced from
byproduct coke oven systems.  The Byproduct process is oriented toward the
recovery of the gases and chemicals produced during the coking cycle.
     The major unit operations/processes involved in the Byproduct coke plant
are:  coal handling and preparation, coking, quenching, primary cooling, tar
separation,  tar extraction, ammonia removal, final cooling, light oil scrubbing,
                                        -1-

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and sulfur removal  (desulfurization).  In addition, some modern coke plants
have chemical refining (upgrading) facilities for recovery of benzene, toluene
and xylene (BTX) from light oils.
     The core of the process is the coke ovens, which are narrow chambers,
usually about 38 to 50 feet long, 13 to 16 feet high, tapering in width from
17 to 20 inches at one end to 15 to 16 inches at the other.  The ovens hold
from 16 to 24 tons of coal, and are usually built in batteries averaging from
80 to 100 ovens.  Although coke production from each oven is basically a batch
process, a coke oven plant is operated such that the battery of ovens con-
tinuously produce coke oven gas and byproduct chemicals.  In the Byproduct
coke oven process, coking is accomplished at temperatures of 1,090 to 1,150°C
and atmospheric pressure for a period of 16 to 27 hours.
     One ton of the low sulfur bituminous coal (approximately 30% volatile
matter, wet and on an "as received" basis) fed into a Byproduct coke oven will
yield following products and byproducts:
                              Quantity, Ibs.
          Coke                     1,430
          Coke breeze                 93
          Tar                         78
          Ammonia, anhydrous           5
          Light oil                   20
          Gas, 10,350 scf            309
          Water                    	65_
                                   2,000
     The principal subdivisions of coal gasification processes are low-,
intermediate-, and high-temperature operations.  These are further subdivided
by operating pressures.  The low-temperature gasification processes tend to
show a complete product and byproduct slate, including oils, tars, and phenols.
As the gasification temperature increases, the quantity of oils, tars and
phenol decreases in preference to lighter products.  The operating pressure
also affects the yields.  As the pressure increases, the product slate becomes
heavier.  For example, in intermediate-temperature processes, recoverable
products such as naphthas and tars increase from zero or negligible quantities
to significant quantities of heavier molecular weight chemical compounds.

                                     -2-

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     Although the Byproduct coke oven process is vastly different from the
gasification processes, many similarities appear to exist between the product
and byproduct slates of the two industries.  Therefore, it was theorized that
the characteristic waste materials from the two industries may be similar.
The report shows that this is true to some extent, but wide variations in
quantities and compositional changes are evident, making comparative
generalizations difficult.
     The coal liquefaction processes are significantly different from the coal
gasification processes, and, again, markedly different from the coke oven
processes.  Yet, the products and byproducts of the coal liquefaction processes
show many similarities to those from Byproduct coke oven process.  All lique-
faction processes produce an acid gas stream which contains sulfur and other
contaminants similar to the raw gases from the coke oven or coal gasification
processes.  Consequently, H^S removal, including sulfur recovery, will be
required for all coal conversion processes.  This control technology is
practiced by many coke oven plants.  The aqueous waste streams of the coal
liquefaction processes contain pollutants  similar to the coke oven industry,
and  the accepted wastewater control  technologies utilized in the coke oven
industry  should be  applicable.
     Table  1-1 provides a comparative listing  of  coke  oven and coal conversion
process and waste streams.  Although many  similar constituents are present  in
the  various streams, their concentrations, temperatures and pressures are
different  (e.g., see Table 1-2 for raw gas compositions).  These are important
variables that will control the selection  of the best  available control
technology  for a particular stream.  For example, note in Table 1-2, the  ratio
of C09 to H S in the streams.  For the Lurgi and Koppers-Totzek  (K-T)
gasification processes, the ratio  is much  higher  than  either the coke oven  or
the  Solvent Refined Coal  (SRC-I) liquefaction  process  streams.  High C02/H  S
ratios make sulfur  removal and recovery more difficult in the gasification
processes.
     A number of processes are being utilized  to  remove hydrogen sulfide  and
recover sulfur from coke  oven  gas.   These  processes are divided into three
major categories:   1)  Liquid Absorption processes  (Vacuum Carbonate, Sulfiban
 (amine type), Firma Carl  Still);  2)  Wet Oxidative processes  (Stretford, Takahax,
                                      -3-

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          TABLE 1-1.  COKE OVEN AND COAL CONVERSION STREAM SIMILARITIES
Coke Oven Streams
Raw gas and acid gas
Process wastewater
Coal pile run-off


Coke breeze

Oily and biosludges
Tar, naphthalene,
light oil, phenol
and ammonia
Coal Conversion
 Counterparts
Raw gas and acid gas
from gasification,
and off-gas from
liquefaction

Process wastewater
Coal pile run-off


Coal fines, chars

Oily and biosludges
Tar, naphthalene
light oil, phenol
and ammonia
  Major Common Pollutants
	or Similarities	
H2S, NH3, CO, C02, COS, HCN
and hydrocarbons
NH~, phenols, oils, sulfides
and cyanides (See Table 1-3
for details)

Suspended solids and organic
extracts

Similar byproducts

Oil, grease and tar, biomass,
refractory organics

Similar byproducts
Fugitive emissions
  .  Coal pile
     Coal charging and
     coke pushing
     Coke quenching
  .  Byproduct recovery
     and storage
  .  Wastewater
     treatment
Fugitive emissions
     Coal pile
     Coal lockhopper
     vent gases
Particulates
Raw gas pollutants and
participates
     Ash/char quenching  Same as above
     Byproduct recovery  Odors, NH_, H.S, hydrocarbons
     and storage         and particulates
     Wastewater          Same as above
     treatment
                                     -4-

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                    TABLE 1-2.   COMPARISON  OF  RAW GASES
Components /Parameters
H2
Cl
C2
C3 to C5
CO
co2
0_
2
No
2
NH3
HCN
H2S
COS
cs2
Light Oil
Tar Oil
Tar
Phenol
H 0
TOTAL
Temp., °F
Pressure, psia
v>O M / £1 A O
w n f ~~O
LurSl<2>
22.63
6.75
0.23
-
11.65
16.16
_

0.18

0.55
0.16
0.203
0.007
-
0.14
0.11
0.10
0.05
41.07
100.00
370
450
79.6
K-T(3)
26.37
—
-
-
51.79
8.82
_

0.69

0.08
0.02
0.41
0.04
-
-
-
-
-
11.78
100.00
2,730
15.3
21.5
(4")
SRC-I Off Gas
31.58
36.39
7.86
5.81
0.22
3.84
_

0.43

-
-
12.68
-
-
1.19
-
-
-
_
100.00
119
24.7
0.303
Coke Oven
38.22
25.51
2.99
-
6.18
1.33
1.26

0.452

0.70
0.16
0.51
0.018
0.01
0.79
-
0.78
0.04
21.05
100.00
1,000
14.3
2.6
1.  Except as noted, all values are in vol %.
2.  Sub-bituminous coal, El-Paso Lurgi process design.  Bibliography 59.
3.  Texas lignite feed containing 1.5% sulfur, 8% moisture.  Koppers-Totzek
    gasifier.
4.  One of the off-gas streams from the Solvent Refined Coal process.   See
    other off-gases in Table 6-5.
5.  Bituminous coal mixture suitable for coking;
    1.0% sulfur,  4% moisture.
                                       -5-

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Giammarco Vetrocoke); and 3) The Dry Oxidative process (Iron Oxide or Dry
Box).  Historically, the Dry Oxidative process using iron oxide has been used
most extensively.  However, the Vacuum Carbonate process, the Stratford
process and, more recently, the Sulfiban process have moved into commercial
prominence.
     The Liquid Absorption processes are called sulfur removal processes,
since they remove sulfur compounds (e.g., H^S) from the raw gas by liquid
scrubbing and generally produce a gaseous stream more concentrated in H S
(during regeneration of the solvent).  The concentrated stream requires
control via a sulfur recovery system — the Glaus sulfur recovery process is
primarily used in the coke oven industry.  The Glaus process initially had
some problems associated with the excessive amounts of hydrogen cyanide, iron
sulfide and iron cyanide present in the above concentrated acid gas stream.
These problems have been resolved after special adjustments to the Glaus unit.
     The Wet Oxidative processes, mentioned earlier, are sulfur recovery
processes in which elemental sulfur is the product.  The Stretford process
does not remove COS or other organic sulfur compounds from the gas stream.
     The H2S removal or sulfur recovery efficiency achievable for the processes
in the coke oven industry are:  Iron-Oxide process - 99 percent (for low gas
volumes); Vacuum Carbonate process - 93 to 98 percent; Sulfiban process - 90
to 98 percent; Stretford process - 99.5+ percent; and the Glaus Sulfur Recovery
process - 95 to 96 percent.
     Among the acid gas removal processes found in the coke oven industry, the
amine and carbonate type solvent processes should have application in low-
pressure gasification processes, or in treating lo7..-pressure offgases from
liquefaction processes.  The two most common sulfur recovery processes in the
coke oven industry are the Glaus and Stretford processes.  Both of these
processes will have wide application in the coal conversion industry.  The
Claus is in service at a number of developing gasification processes, e.g.,
both the Hygas and Bigas pilot plants have Claus sulfur recovery units.  The
Stretford process is also in service at a number of coal conversion processes,
e.g., Synthane pilot plant, Pittsburgh Energy Research Center, the SRC pilot
plant at Fort Lewis, Washington, and the Sasol coal conversion plant in South
Africa.  Generally, the Stretford process is more economical when the acid gas
stream contains less than 15 percent H.S, whereas the Claus process is the
economic choice for levels above 15 percent.
                                     -6-

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     Consideration must be given to the interferences caused by high C09 and
othar impurities in the application of both the Glaus and Stretford processes
when used for coal conversion systems.  C09 tends to neutralize the Stretford
solution and reduces the absorption rate of the H^S, thus necessitating higher
rates of solvent circulation and larger units.  High C09 affects the stability
of the flame in the Glaus reactor, and also results in higher COS concentrations
in the tail gas from the Glaus unit.  Additional control of the tail gas from
the Glaus unit would be required before emission to the atmosphere.  Other
impurities also have undesirable effects on the Glaus unit.  For example, in
the presence of ammonia, ammonium bicarbonate can form which reduces the
performance of the Glaus catalyst.
     A comparison of the wastewater characteristics of the different processes
are shown in Table 1-3.  Although many similar constituents are present, their
concentrations vary from process to process.  The process wastewaters from
the Byproduct coke plants contain large amounts of phenol, ammonia, sulfide,
cyanide, and oil and grease.  Various control technologies are being used to
remove these pollutants.
     Ammonia is being removed and recovered by steam stripping at alkaline pH,
or by Phosam-W, a proprietary (U.S. Steel) process that uses scrubbing
(ammonium phosphate solution) and distillation in combination to produce an
anhydrous ammonia product.  Sulfide removal from wastewater by steam stripping
is not commonly practiced in the coke oven industry.
     Phenols are being  removed by solvent extraction, steam stripping and/or
biological oxidation, and carbon adsorption.  Biological treatment has been
successful with coke oven wastewaters in meeting existing phenol regulatory
limitation.  Phenol removal efficiency of about 99.8 to 99.9 percent has been
achieved by the activated sludge system: B.O.D. removal has ranged from 85 to
95 percent.
     All the above coke oven wastewater treatment and byproduct recovery
technologies should have application in coal conversion waste treatment.
Except for the low pressure and high temperature gasification processes (e.g.,
K-T process), other gasification and all coal liquefaction processes appear to
produce process wastewaters with similar pollutants and composition ranges
(See Table 1-3).  Therefore, coke oven technologies should be applicable to
these processes for wastewater treatment.
                                      -7-

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                  TABLE 1-3.  COMPARISON OF PROCESS WASTEWATERS
PH
Suspended Solids
Phenol
C.O.D.
Thiocyanate
Cyanide
Ammonia
Chloride
Carbonate
Sulfide
Coke Plant v '
Ammonia
Liquor
mg/1
8.4
4,000
1,000
10,000
1,000
50
5,000
6,000
-
1,250
(2)
Synthane
mg/1
8.6
600
2,600
15,000
152
-.
8,100
500
6,000
1,400
U,rgl<3>
mg/1
8.9
5,000
3,500
12,500
-
-
11,200
-
10,000
-
Koppers-
Totzek SRC-I
mg/1
8.9
50
-
70
-
0.7
25
600
1,200
-
mg/1
8.0
300
4,500
15,000
-
-
5,600
-
-
4,000
1)  See other wastewater compositions in Section 4.
2)  Illinois No. 6 Coal feed.  Bibliography 26.
3)  Lurgi Sasol plant wastewater.
4)  Private communication with the Koppers Co., Inc., Pittsburgh, Pa.
                                      -8-

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     Many coke oven plants recycle wastewaters containing high-cyanide con-
centration for coke quenching.   Although alkaline chlorination of cyanide
containing wastewaters is successfully practiced elsewhere in steel mills, it
is not used for coke oven wastewaters because existing cyanide limitations for
the coke oven industry are met without additional treatment.  Quenching of ash
and char with untreated wastewater may not be premitted for the coal conversion
industry.
     Some coke oven plants use a byproduct light oil upgrading process which
has a potential application in the synfuels industry.  This process, called
         (10
the LITOL    process, has been developed and licensed by the Houdry Division
of Air Products and Chemicals,  Inc.  It is a catalytic process by which coke
oven light oils are refined and dealkylated to produce high quality, even
reagent grade, benzene at essentially stoichiometric yields.  The process has
been used commercially since 1964, and is in use in the U.S. and several other
countries.
     The coke ovens are a major source of air pollution emissions in the steel
industry.  Topside coke oven workers have a substantially higher risk of lung
cancer than the average worker, probably from carcinogenic materials associated
with the particulate  fraction of  the coke oven emissions.  Various schemes to
control  these emissions and alleviate potentially adverse health effects are
being developed.
     These include:   coke oven equipment design changes; improved coke oven
operating and maintenance techniques; collection of  coke oven fugitive
emissions; and control of coke oven fugitive emissions.  Equipment design
changes include such  items as:  adding another gas collection main on coke
oven battery; hydraulically operated mechanical gooseneck cleaners; magnetic
lid lifting equipment on larry car; screw feeders on all larry car discharge
hoppers; modified steam aspiration nozzles; modification of stand-pipe caps;
replacement of luted  doors with knife-edge self sealing doors equipped with
spring-loaded adjustable plungers to maintain design pressure on knife edges;
and sealing of leveler door.
     Improved coke oven operating and maintenance techniques include various
innovative procedures designed to minimize fugitive  emissions from openings
and leaks associated with the charging, coking cycle, pushing/discharging and
underfiring/heating operations.  The collection of coke oven emissions include
                                      -9-

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various hood and duct configurations which are custom designed to withstand
high temperatures and to handle corrosive gases.  Also, they must be able to
offer the maximum collection efficiency with the least interference to the
coke making operations.
     The control of the fugitive emissions subsequent to collections has been
successfully applied by use of the following air pollution control devices:
high energy scrubbers, electrostatic precipitators and fabric filters.  These
devices have proven capable of capturing submicron particle size fractions of
the smoke and particulate matter associated with coke oven fugitive emissions.
Also, the devices are able to handle large volumes of corrosive gases containing
condensed tar at their upper temperature limits (600 to 1,000°F).  These
fugitive emission control technologies will have application in the synfuels
industry in analogous operations, e.g., in ash quenching, SRC  solidification
operations, and in the collection and control of the building exhausts and
vents associated with coal conversion systems.
     A summary list of the various coke oven control technologies that may
hav6 potential applications in the coal conversion industries is shown in
Table 1-4.
     A majority of the control technologies listed in Table 1-4 has been
tested in coal conversion applications; however, most of these applications
have been in process development unit or pilot scale coal gasification and
liquefaction systems.  A few successful uses have been with commercial first
generation coal gasification processes, e.g. the Lurgi process.  Applicability
of the control technologies does not mean that the control technology can be
duplicated (similar size equipment) from the coke oven design to the coal
conversion application.  In general, the composition, flow rate, temperature
and pressure of the specific coal conversion system wastes will not be identical
to the coke oven case; these differences, however, must be taken into conside-
ration during the design of the control technology.  Design information or
scale up factors in comparison to coke oven application should be developed
through laboratory or pilot scale testing with actual coal conversion wastes
to determine the system design and to develop its costs.
                                     -10-

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              TABLE 1-4.   COKE PLANT CONTROL TECHNOLOGIES AND THEIR

                              APPLICABILITY TO COAL CONVERSION
Coke Plant Control Technology
Applicability To Coal Conversion Systems
Acid Gas Treatment
     Amine solvents
     Carbonate solvents
     (e.g. Vacuum carbonate
     and Benfield)
Suitable for removal of H^S and C0_ from
low pressure raw product and off gases.
Solvent degradation may be encountered.
High C0? level may produce a Glaus feed
with too low an H?S concentration.

Suitable for selective removal of H_S and
CO,,.  Processes partially remove carbonyl
sulfide and cyanides.
Sulfur Recovery
     Stretford
Suitable for low H2S  (less than 15%)
containing gases.  Organic sulfur not
removed.  High CO- levels require large
units.
     Glaus
Applicable  to high H2S  (greater than 15%)
containing  gases.  Removal of high levels
of  cyanide, ammonia and hydrocarbons will
be  required.
Fugitive Emissions Control

     Enclosed coke pushing
     and quenching system

     Fume recovery and
     scrubbing

     Improved operating
     Procedures and
     maintenance
Potentially  suitable for  ash quenching,
SRC solidification applications.

Applicable to analogous sources
Applicable  to analogous sources
Byproduct Recovery/Refining

     Ammonia from wastewater
     (Stripping, Phosam - W)

     Ammonia from raw gases
     (Scrubbing, Phosam - W)
Suitable for sour waters.
Applicable  to low pressure gas
purification.
                                       -11-

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                              TABLE 1-4 (Continued)
Coke Plant Control Technology

(Byproduct Recovery/Refining
 Continued)
     Phenol from wastewater
     (Solvent extraction)

     Tar, naphthalene, 1ight
     oil from raw gases
     Light oil refining
     (e.g. Litol process
     and solvent extraction)
Applicability To Coal Conversion Systems
Suitable for process wastewater
containing 1,000 mg/1 or more phenol.

Suitable, but design must be modified
for different pressures, temperatures
and compositions.

Suitable for recovery of BTX from coal
derived naphthas.
Wastewater Treatment Technology
     Biological oxidation;
     carbon adsorption;
     ammonia, phenol and
     oil removal processes
Generally applicable:  design basis must
be established for the specific waste.
                                      -12-

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     An assessment of the health effects of coke oven emissions was recently
made by EPA (Office of R&D)  and a .draft report was issued in April, 1978.  The
summary findings of the above report are as follows:
          Exposure to coke oven emissions provides an elevated risk for cancer
          of all sites and non-malignant respiratory diseases to coke oven
          workers and an increased risk among lightly exposed workers (non-
          oven workers in coke plant).
          The general population, which includes the young, the old and the
          infirm in the vicinity of a coke oven plant should be considered
          more susceptible than the workers, especially for development of
          chronic bronchitis, since they are generally in poorer health.
          Coke oven emissions contain an array of identified carcinogens,
          irritants, particulate matter, trace elements, and other chemicals.
          The toxic effects observed in both humans and animals are greater
          than the effects that can be attributed to any individual component.
          Thus "coke oven emissions" as a whole should be considered the toxic
          agents.
          There is an exposure difference of about 2 orders of magnitude
          estimated between  lightly  exposed workers and people living in the
          vicinity of a coke plant.  Since these lightly exposed workers show
          an elevated risk for cancer and non-malignant respiratory disease,
          it is reasonable to assume that levels up to one-hundreth of  those
          to which lightly exposed workers are subjected could cause an
          increased risk to  the general population.
     Since the coke oven and the  coal conversion system emissions have  many of
the same hazardous components in  high concentrations, such as H^S, CO,  C0_,
hydrocarbons and polynuclear aromatics, there is a potential occupational
health hazard to coal conversion  plant workers and the general population in
the vicinity of the plant.  Many  of  the new control technologies under
development in the coke oven industry, especially those for fugitive emissions
control, should result in significant removal of these hazardous pollutants.
Whether or not additional controls will be required cannot be defined yet,
since these new technologies have not been in use for a sufficiently long
period of time.
                                      -13-

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                                    SECTION 2
                                  INTRODUCTION

     In the primary contract with the U.S. Environmental Protection Agency,
Catalytic, Inc. has been directed to conduct a program aimed at:  assessment
of pollution control needs, determination of available control technologies,
and development of new control technologies for the products and byproducts of
coal conversion (coal gasification and liquefaction) systems.  Whereas there
appeared to he gross similarities between the products, byproducts and waste-
streams from £he coal conversion and coke oven industry, and whereas the
application of coke oven controls to the coal conversion industry appeared to
be transferable, one of the assigned tasks (Task No. 10) in the project has
been to determine the potential applicability of coke oven control technologies
to the coal gasification/liquefaction industry.
     The coke oven industry is long established and employs many types of air
and water pollution control equipment.  This industry has been active in the
development of new environmental control technologies, especially for fugitive
emission control, desulfurization and process wastewater treatment.  The
objective of the Catalytic study has been to review the coke oven control
technologies and identify those that would have application to coal conversion
process/waste streams.  The approach methodology lias been to characterize
(compositions and quantities) those coke oven process and waste streams which
have counterparts in coal conversion processes, and to identify and review the
control technologies that could be applied to the coal conversion industry.
     A meeting and discussions were held with representatives of the American
Iron and Steel Institute (A.I.S.I.) and the American Association of Coal and
Coke Fuel Dealers to obtain technical data.
     A plant visit was made and consultations were held with representatives
of an operating coke plant for first hand observations and discussions of the
applications of processes and control technologies.  To supplement discussions
                                     -14-

-------
with E.P.A.,  A.I.S.I,  and others, a comprehensive literature review was
conducted utilizing computer-based technical literature search services to
obtain published information on environmental controls and processes relating
to coke oven systems byproducts.  From the approximately 250 technical articles
and text abstracts retrieved, a large number of publications were found to
have significant information pertinent to the study.
     Existing and proposed State and Federal regulations concerning disposal
and treatment of waste materials were reviewed and are included in this report.
     A brief assessment of health effects attributed to coke oven emissions,
based principally on information released in draft form by the EPA's Office of
Research and Development, is also part of this report.
     A material balance for a typical coke plant was prepared.  The balance
embraces all the major unit operations and provides approximate compositions
and quantities of the major process and waste streams.  Both literature
references and engineering judgment were applied in developing this infor-
mation.
     Comparisons of the waste characteristics from coke ovens with selected
coal gasification and liquefaction process wastes have been made and recom-
mendations offered regarding the control technologies for  air, water and  solid
wastes  that  could be appropriately applied  to coal conversion processes,
including discussions on  the conditions of  applicability.
     Results of an extensive review of coke  oven control technology have  been
reported with  special emphasis  on coke oven  gas desulfurization and wastewater
treatment  control strategies.   Capital and  operating  cost  data for  these
control strategies and some  major process unit operations  are included,
whenever available.
                                      -15-

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                                    SECTION 3
                       DESCRIPTION OF COKE OVEN PROCESSES

     Coke is made from the destructive distillation of coal in an oven or
retort in the absence of air; a process also referred to as pyrolysis or, more
frequently as carbonization.  Coke is the solid carbonaceous residue remaining
after the high-temperature distillation of moisture and volatile matter from
the coal.  It is used primarily in blast furnaces, in foundries and in gas
producers.  Approximately 16 percent of the bituminous coal mined in the
United States is converted to coke.
     The coal used in coke making is usually a blend of high-volatile coal
with 10 to 50 percent low-volatile coal.  In order for the coal to form a
strong, coherent coke, expansion is restrained in the oven during the heating
process.  Also, the coal should not contain more than 1.5 percent sulfur or 9
percent ash.  Bituminous coal is the most suitable type because it has the
best agglomerating properties.
     Besides coal types, other important variables that affect coke and
byproducts characteristics are oven temperature, residence time and oven
construction features.  For example, the effect of carbonizing temperature on
the yields of coke and byproducts are shown in Figure 3-1.  Although a small
amount of coke has been made in the United States by low-temperature (450 to
700 C) and medium-temperature (700 to 900 C) carbonization, most of the coke
is produced by high-temperature carbonization at 1,000 to 1,150 C.
     There are two proven high-temperature processes:  "Byproduct" coke oven
(recovery type) and "Beehive" (nonrecovery) processes.  Approximately 98
percent of the total coke production in the United States is from Byproduct
coke plants.  Therefore, the major focus of this report will be on the
Byproduct coke oven process, with only brief discussions of the Beehive and
low-temperature processes.
                                      -16-

-------
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                                        (43)
             from Upper Banner seam coal

-------
BYPRODUCT COKE OVEN PROCESS
     The Byproduct process is oriented toward the recovery of the gaseous and
liquid chemicals produced during the coking cycle.  The principal unit of
equipment in the manufacture of coke is the coke oven, which is a narrow
chamber, usually about 38 to 50 feet long, 13 to 16 feet high, and tapering in
width from 17 to 20 inches at one end to 15 to 16 inches at the other.  A
typical oven holds from 16 to 24 tons of coal, and the ovens are usually built
and operated in batteries of 10 to 100 (typically 80 to 100) ovens.  Although
coke production from each oven is basically a batch process, a coke oven plant
uses this battery of ovens for continuous production of coke oven gas and
byproduct chemicals.  Some of the major high-temperature coke oven processes
with their characteristic differences are:
          Process/Developer                Description
          Koppers (Includes Becker)        Cross-regenerative
                                           byproduct oven
          Wilputte                         Vertical flue oven
          Semet-Solvay                     Horizontal heating flues
          Otto                             Vertical flue ovens
     The batch coke making step and the continuous processing of the raw coke
oven gas are described in the following paragraphs.

General Process Features
     Coal is charged to the ovens through ports in the top, which are then
sealed.  The heat required to maintain the high temperature is supplied to the
ovens by burning some of the coke oven gas produced.  Coking is largely
accomplished at temperatures of 1,090 to 1,150 C and at atmospheric pressure
for a period of about 16 to 27 hours.  At the end of the coking period, the
coke is pushed from the oven by a ram and quenched with water in an area
remote from the ovens.
     The gaseous mixture generated in the Byproduct coke oven is composed of
permanent gases which form the final purified coke oven gas for the market,
accompanied by condensable water vapor, tar, light oils, solid particles of
coal dust, and heavy aromatic hydrocarbons.  Figure 3-1 shows the yields of
coke oven byproducts at various carbonizing temperatures for a given coal
                                     -18-

-------
type.  The raw gas also contains pollutants such as ammonia, hydrogen cyanide,
cyanogen, hydrogen sulfide, carbonyl sulfide and carbon disulfide.  Since raw
gas from coal gasification processes and off-gas from coal liquefaction
processes contain chemicals and pollutants similar to those listed for the raw
Byproduct coke oven gas, it is of significant importance to this study to
place particular emphasis on the processing schemes used to remove, recover or
destroy these chemicals and pollutants.
     Figure 3-2 is a process block flow diagram of a typical byproduct coke
oven plant.  It shows the various processing schemes used to recover chemicals
and remove pollutants from the raw coke oven gas.  The sequence of the unit
operations can be varied; however, the following process sequence for the
manufacture of coke and its major byproducts is typical:
     1.   Coal is transferred, crushed, and screened.
     2.   Coal is charged to a hot empty oven.
     3.   Coal is chemically transformed to coke and volatiles by pyrolysis.
     4.   Hot coke is pushed out of the oven, quenched, and transported for
          storage and use.
     5.   Some condensable products (primarily tar and ammonia) are condensed
          and collected in the hydraulic main and primary cooler.  Tar and
          excess ammonia liquor are recovered.
     6.   Coke oven gas is pulled through an exhauster with a suction of 15 to
          20 inches of water and is discharged at a pressure of 45 to 75
          inches of water.
     7.   The coke oven gas then passes through electrostatic precipitators
          which remove most of the remaining traces of tar.
     8.   Ammonia is removed from the gas as ammonium sulfate, or as anhydrous
          ammonia.
     9.   The gas is further cooled and light ends are removed by absorption
          in a petroleum-based absorbent  (e.g., No. 2 fuel oil, straw oil).
          Some plants have the facilities to upgrade or refine the light oil
          and recover benzene, toluene and xylene  (BTX).
    10.   Hydrogen sulfide is removed from the coke oven gas using various
          processes (see Section 4).
    11.   Clean coke oven gas is metered and sent to users.
                                     -19-

-------
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Figure 3-2.  Simplified block flow diagram of a byproduct coke oven plant.

-------
Detailed descriptions of the foregoing operations and processes are presented
in the following paragraphs.

Coal Handling and Preparation
     The primary functions are to prepare coal by blending, crushing mixing,
and pulverizing it to the required size and to transport the prepared coal to
the ovens for coking.  A typical analysis of a mixed coal charge would be as
follows:
                                        Percent
                                        (by wt.)
          Volatile Matter                30.00
          Fixed Carbon                   63.65
          Ash                             5.50
          Sulfur                          0.85
                                        100.00
     As mentioned previously, a blend of high-volatile bituminous coal with 10
to 50 percent of low-volatile bituminous coal is used to obtain a composition
similar to the above analysis.
     After blending, the coal is crushed until it passes through 2-inch
openings, and is then pulverized in  a hammer mill so that  about 80 percent
passes through a 1/8-inch screen.  In the hammer mills, approximately 0.1
gallon of oil per ton of coal is added  to control the bulk density of the coal
which is then ready for charging to  the coke oven.

Coke Oven Operation
     The coal is delivered  to the  ovens by means of charging  cars  (larry cars)
that transport a measured amount of  coal from the storage  bins.  This coal  is
introduced into the ovens through  charging holes at the top.   The ovens are
heated by either raw or purified coke oven gas, which burns in vertical heating
flues set in the side walls of the ovens.  Air for combustion is drawn through
regenerators which cool the-flue gases  to about  750 F before  entering the
stack.  About 40 to 45 percent of  the total  coke oven gas  produced is used  to
supply heat for the ovens.
     When the coal is charged into a hot oven, the layer of coal adjacent to
the heated walls is quickly decomposed. A plastic layer is formed,  and moves

                                     -21-

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slowly toward the center of the oven as carbonization proceeds.  Coal is an
extremely poor conductor of heat and the center of the charge remains at a low
temperature for several hours.  The average coking rate is about 1 in/hr (1/2
in/hr from each side) and it takes about 16 hours to complete the coking
cycle.  At the end of the cycle, the coke is pushed out of the oven into a
quench car.  The hot coke is quenched by a water spray, and is then dumped
onto an inclined coke wharf where it dries and cools.

Recovery of Tar and Ammonia liquor
     The volatile matter and gas evolved during the coking process (raw coke
oven gas) leave the ovens through standpipes (vents) and pass into a gas
collecting main.  There, the temperature of the gas is reduced from a range of
approximately 800 to 1,300°F to about 175 to 200°F by spraying it with recycled
ammonia liquor.  This reduction in gas temperature causes condensation of
approximately 75 percent of the tar in the gas and most of the water vapor in
the raw gas.
     From the collecting main, the gas passes to the primary coolers, where it
is cooled to about 85 to 104°F by ammonia liquor spray.  This cooling removes
additional tar and water vapor and, again, a small portion of the total
ammonia in the gas.  The gas is next conducted to an exhauster (positive-
displacement type).  Beside compressing the gas, -it also serves to remove tar
by the high—speed swirling motion imparted to the gas.
     The gas passing through the exhausters still contains traces of tar fog,
which is further reduced by electrostatic precipitators (ESP).  The tar drains
from the bottom of the precipitators into a settlirg pit, which also collects
the tar removed in the collecting main and primary coolers.  It is then pumped
from the pit and transferred to a storage tank, where water is decanted.  This
tar, containing approximately 2 to 5 percent moisture, is sold for processing
and recovery of valuable aromatic compounds such as food coloring.
     The condensed water, which results from gas cooling in the collecting
ma-fn and primary coolers, appears as excess ammonia liquor and is the major
process wastewater from the Byproduct coke oven plant.  This stream is also
referred to as ammonia liquor blowdown.  The excess ammonia liquor is treated
before discharge for byproduct recovery and pollutant removal according to the
various schemes discussed in Section 7.

                                     -22-

-------
     The coke oven gas which has passed through the tar extractors (ESP) is
next sent to the ammonia removal unit for recovery of ammonia by one of the
following methods:
     1.   Indirect process.   The ammonia is removed from the gas by scrubbing
          with water.   Scrubber blowdown is treated by an alkali solution and
          steam stripping; the stripped vapor is then passed through a saturator
          containing a solution of sulfuric acid to recover ammonium sulfate.
     2.   Direct process.  Raw coke oven gas, after separation of tar, is
          passed through a saturator containing a solution of sulfuric acid to
          remove ammonia.
     3.   Semi-direct process.  The ammonia in the liquor, which is produced
          by direct and indirect cooling, is removed by alkali treatment and
          distillation, and added to the gas stream.  This stream is then
          passed through an absorber (saturator) containing dilute sulfuric
          acid to extract the ammonia as ammonium sulfate.
     Of these three processes, the semi-direct, developed by Koppers,  is most
extensively used in the U.S.  (Note:  A new process known as Phosam-W  (U.S.
Steel) is emerging.  This provides for ammonia removal by scrubbing the gas
with a lean ammonium phosphate solution and then recovering anhydrous  ammonia
from the scrubbed liquid by stripping and distillation.  See further discussion
of this process in Section 7.0).
     After the ammonia removal unit, the gas passes through the final  coolers
where direct contact water is used to cool the gas to a temperature of  70  to
90 F.  A major portion of the naphthalene condenses out of the gas as  a result
of this cooling and is recovered from the cooling water at the settling basin
or in flotation cells where it is skimmed off as it rises to the  top.  The
naphthalene is either added to the tar or is processed further to produce  a
commercial product.  In some facilities, it is recovered from the cooling
water by having tar circulate countercurrently to  the flow of water in the
base of the final cooler.
     For the recovery of light oil, which is generally the last step in the
coal chemical recovery process, there are three general methods used:
     1.   Refrigeration and compression involving  temperatures below minus
          70 C and pressures of 10 atmospheres.
                                     -23-

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     2.    Adsorption by activated carbon followed by heating to recover organic
          compounds.
     3.    Absorption by solvents involving washing of the gas with a petroleum
          solvent, coal-tar fraction, or other absorbent, followed by steam
          distillation of the enriched absorbent to recover the light oil.

Light Oil Refining
     The traditional method for purifying the recovered light oil is to wash
it with sulfuric acid and caustic soda, followed by distillation to separate
benzene, toluene, xylene (BTX), and solvent naphtha cuts.  The thiophene
content of benzene produced by acid washing is high (100 to 400 ppm) and
precludes utilization of this benzene in many chemical reactions, particularly
where sulfur sensitive catalysts are employed.  As a result, coke oven BTX has
a less marketable demand than petroleum derived benzene, which contains less
than 1 ppm thiophene.
     The Houdry LITOL process was developed to purify the light aromatic
fraction produced as a byproduct of high-purity BTX and is also capable of
dealkylating the toluene and xylene to benzene at high selectivities, whenever
desired.  Nonaromatic materials  (mainly paraffins, olefins, diolefins,
naphthenes, and sulfur compounds) are completely converted to lighter hydro-
carbons and to hydrogen sulfide.
     Figure 3-3 shows a simplified block flow diagram for the LITOL process.
Applicability of the LITOL process to coal conversion systems is discussed in
Section 7 under Light Oil Upgrading Processes.

Desulfurization of Coke Oven Gas
     The gas, after being stripped of its ammonia and light oil, is next  sent
to the desulfurization unit for sulfur removal.  Many processes available for
gas purification are discussed in detail in Section 7.  Historically, the dry
oxidative process using iron oxide boxes has been the most extensively used
method for sulfur removal.  However, the Vacuum Carbonate, the Holmes-Stretford,
and more recently, the Sulfiban process have moved into commercial prominence.
     After the gas is desulfurized, it is ready for use as a clean fuel.
                                     -24-

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 NAPHTHA
(LIGHT OIL)
                                           LIGHT HYDROCARBONS
                                            AND
HYDROTREATMENT
  REACTORS
                        T
                                               I
                                            SEPARATOR
STABILIZER TOWER
 CLAY TREATER
                      HYDROGEN
                                                  BTX PRODUCTS
                                                                   DISTILLATION
                                                                     HEAVIER
                                                                    AROMATICS
               Figure 3-3.  Simplified block flow diagram of the Houdry LITOL  Process,

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OTHER COKE OVEN AND RELATED PROCESSES
Beehive Process
     Except for the coke, this is a nonrecovery type of process.  The Beehive
oven is a refractory-lined enclosure with a dome-shaped roof.  The coal charge
(10 to 15 tons), deposited onto the floor of the oven through a trunnel head
in the roof, is leveled to give a uniform depth of material.  Openings above a
door on the side of the oven are restricted to control the amount of air
reaching the coal.  This air is required to burn the volatile products dis-
tilled from the coal and thus generate heat for further distillation.  The
carbonization process begins at the top of the coal pile and works down
through it.  The volatile matter being distilled burns near the top of the
oven and the combustion products leave through the opening in the roof.  Upon
completion of the coking (which takes from 48 to 96 hours), the coke is
"watered out" or quenched.  After quenching, the coke is "drawn," i.e., removed
either mechanically and/or by hand.

Low Temperature and Recent Processes
     There are numerous types of process equipment used and byproducts generated
from the low-temperature processes.  Most of these processes are commercially
prominent in Europe for the production of domestic fuels, along with gas and
chemical byproducts.  Table 3-1 summarizes some old commercially developed
low-temperature carbonization processes.
     The only commercially successful, low-temperature (570 C) carbonization
process ever utilized in the United States was the "Disco" process.  However,
because of the availability of other cheaper fuels, the company discontinued
the process in 1963.
     In the Disco process, wet fine coal from the washery goes through five
basic steps:  predrying; roasting; carbonizing in the retorts; cooling the
char; and screening and loading.
     The process is unique because it produces a final semicoke or lump char
directly from the fine coal in indirectly heated continuous rotating retorts.
This is done, without a briquetting step, through preliminary oxidation or
"roasting" of the coal in contact with air, thus destroying a portion of its
excessive caking characteristics.  In the rotating retort, the oxidized coal,
together with recycled char, rolls up in'to balls of char without adhering to
the sides of the retort.  The balls of char are screened and sold as smokeless
domestic product.
                                     -26-

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                                      TABLE 3-1.  OTHER COKE OVEN AND RELATED PROCESSES
    Process
    Disco
    Status
Was installed
by Disco Co.
near Pittsburgh
in the 50s.
Objective         Process Description

Coke, tar     Designed for certain coals.
and gas.      Bituminous coal, ground to
              3/8-in size, is heated in
              a revolving steel retort.
              The carbonizer gas is at
              450-480°C.
    Distribution of
Contaminants in Products

The low temperature of
operation does not remove
any contaminants.  Feed
coal has 2.2% S, and coke
produced has 2.1% S.
     Hayes Process
i
NS
     Krupp-Lurgi
     Process
Was  operated by
Allis-Chambers
Moundsville, W.V.
in the 50s.
 Developed in the
 30s.   Only large
 scale plant is
 in Germany.
Coke, tar     Uses a rotating tube retort
and  gas,      with a screw  conveyor.  The
              temperature at feed end is
              595-705°C.  The gas has a   ,
              heating  value of  939 Btu/ft"
 Coke,  tar      Oven  consists  of  six carboni-
 and gas.       zation cells;  entering gas  is
               at  620°C and exit gas at
               570-580°C.
Coke contains 3.5% ash
compared to 9.85% for
coal.
The ash  content of coke
is 3.8%  versus 5.4% for
coal.  The  gas contains
6% nitrogen.
     Brennstoff-Technak  Process developed   Coke
     Cellon Jones Oven
     Carmaux Oven
     Otto Retort
     Weber Process
     Phurnacite Process
     Parker Retort
 for specific
 coals, e.g.,
 slightly caking.
                                   Fixed-bed operation is used.
                                               The temperatures control
                                               contaminant removal from
                                               the coke.
      Rexco Process
 Developed and
 operated in
 England.
 Coke, tar     The directly heated fixed-bed
 and gas       retorts are operated at 700 C.
 Rexco coke has 7.2% ash
 versus 4.9% for coal.

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                                               TABLE 3-1.   (Continued)
Process
Koppers
    Status
Developed in
Germany.
Objective         Process Description

Coke, tar     Uses a continuous vertical
and gas       retort for non-caking coals.
              Temperatures of 800-1,000°C
              are attained.
    Distribution of
Contaminants in Products

Higher temperatures
would remove S, N and
trace metal contaminants
from the coke.
Parry Process
Developed by
U.S. Bureau of
Mines
Coke, tar     Uses entrained carbonization;
and gas       temperatures are 1,038 C.
Fine particle size of
Feed coal and high
operating temperatures
remove S, N and trace
elements from the coke.

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     The byproduct gas generated during carbonization is cooled, scrubbed, and
returned to the retort furnace to .provide heat for carbonization.  Low-
temperature tar is recovered and sold,, for further processing.
Recent Processes—
     In order to find solutions to our energy problem, several new coal
carbonization/pyrolysis processes are in the developmental stage.  They produce
more liquids and gas products than the Byproduct coke oven process.  Table 3-2
briefly describes these new processes.   Additional characteristics of the
important processes are given in Sections 5 and 6.
     There are no commercial low temperature coke oven processes available in
the U.S. today.  However, low temperature carbonization of the char and filter
cake residue of some coal liquefaction processes such as the SRC-I process is
being considered for recovery of carbon values.  (Note:  The SRC-I process is
discussed in further detail under Section 6 of the report.)
     FMC Corp. operates a demonstration plant  (265 TPD) in Kemmerer, Wyoming
which produces a coke from sub-bituminous, and non-coking local Wyoming coals.
The FMC coke process is a continuous process unlike the coke oven battery
which is a cyclical batch operation.  The process consists of a pyrolysis
section where coal is devolatilized in a sequential series of fluid beds
operating under controlled time, temperature and environmental conditions.  It
also has a coke forming section consisting of briquetting, curing and coking.
The coke product is not exposed to the atmosphere until it appears as cooled
product being delivered to the storage silo.  There are no pushing, charging,
door, topside or quenching emissions as associated with the byproduct coke
ovens. Emissions which do occur are from the coal.preparation section and the
three vessels in the fluid processing section.  These emissions are incinerated
in a front end afterburner, emissions from briquetting are also controlled by
the front end afterburner after passing through cyclonic separators.  Emissions
from the fluid bed primary and secondary coolers are combined and passed
through a single baghouse.  .The organic emissions from the curing oven and
kiln are oxidized in a back end afterburner.  Fugitive emissions from kiln air
locks, coke cooling, coke loading and associated transfer points are controlled
by a baghouse.  No commercial plant has been built based on this process.
                                      -29-

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                              TABLE 3-2.  RECENT COAL CARBONIZATION/PYROLYSIS PROCESSES
Process
    Status
Char Oil Energy
Development
(COED)
Developed by
FMC, Princeton*
MJ in 1962: 36
tons/day pilot
plant.
COED/COgas
process has
been selected
for
demonstration.
Objective

Maximize
liquid
production
from coal by
pyrolysis.
    Process Description

Us«s multi-stage fluidized-bed
pyrolysia of coal.  Catalytic
hydrotraating of the oil
yields synthetic crude
suitable as petroleum refinery
feedstock.  The product gas
can be used as boiler fuel or
for gasification.  Four
fluidized beds have temperatures
from 316-816°C; char 59.5%, oil
19.3%, gas 15.1%, liquor 6.1%,
based on Illinois No. 6 coal.
    Distribution of
Contaminants in Products

The low temperature of
pyrolysis will concen-
trate the trace elements
and N, S compounds in the
char.  The liquid product
contains S, N which are
removed by hydrotreatment.
COALCON
(Hydrocarboni-
 zation)
Developed by
Union Carbide:
pilot plant in
South Charleston
Produces      Sized, driad and preheated
liquid and    coal is fed to a dry,
gas           fluidized-bed hydrogenation
              is gasified.
                                 First state hydrogenation
                                 would remove S, N to some
                                 extent depending on
Clean
Coke
Developed by
U.S. Steel
1972
500 Ib/day  (Process
Development Unit)
              Detailed designs of PDU's
              on:  (1) Coal and coke
              preparation, (2) Carbonization,
              (3) Hydrogenation,  (4) Slurry
              oil preparation, and (5) Binder
              preparation.  Coal after
              beneficiation is split into
              two fractions.  Portion of coal
              carbonized and desulfurized to
              produce metallurgical coke.  The
              rest of coal is slurriad with
              process derived oil and
              hydrogenated.
                                 The liquid produced is
                                 desulfurized by hydrogen
                                 treatment.  The char
                                 contains 0.5% S versus
                                 1.74% for coal.

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    Process
    Cogas
    Status
Developed by
Cogas Develop Co.,
Princeton, 2.5 TPD
and 50 TPD pilot
plants are being
operated.  COED/
Cogas has been
selected for
demonstration.
       TABLE 3-2.  (Continued)

Obj active         Process Description
              Variation of COED process;
              Gasifier-Combuster operates
              at 816-927°C.  Med-Btu gas
              is cleaned of S.
                                     Distribution of
                                 Contaminants in Products

                                 The liquid is desulfurized
                                 by hydrogen treatment.
    Garrett's Coal
    Pyrolysis
i
u>
Developed by
Occidental
Petroleum Corp.
3.6 TPD pilot
plant is being
tested.
              Crushed coal is introduced
              into the pyrolyzer in a
              stream of recycle gas and is
              pyrolyzed at 593°C through
              contact with hot char
              (649-841°C).  Part of product
              gas is reformed for hydrogen
              to hydrotreat tar.  Tfields
              are:  char 56.7%, tar 35%,
              gas 6.5%, and 1.8% water.
                                 Desulfurization of char
                                 by acid treatment is
                                 proposed.  The trace
                                 elements will concentrate
                                 in the char.
    Fractional
    Carbonization
    of  coal.
Eddinger, R.T.,
et al.
U.S. Patent
3,574,065
Liquids
and gas
Staged pyrolysis and final
combustion is used.
Fate of trace elements
is the same as in any
carbonization study.
    Pyrolyzing  of
    solid  or
    liquid fuel.
A.M. Squires;
U.S. Patent
3,597,327
8/31/71
Gas and
char
Uses a two-stage fluidized-
bed pyrolyzer.  The heat is
supplied to the lower zone
by conduction from the top
zone.  The lower bed
carbonizer is at 760 C and
the top one at 949°C.
Dolmite is used to remove
the sulfur.
Fuel gas and coke
products free of sulfur
are produced.  The fate
of trace elements is
not mentioned.
(It is postulated that
they would end up in
the coke pellets.)

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     Pennsylvania Control Technology, Inc. has developed a prototype non-
recovery type coking process which claims to minimize pollutant emissions.
The unit presently operating at the Alverton Fuel Co., Alverton, Pa. essentially
consists of two ovens with a single flue heating system.  The hot gas from the
combustion of the coal is mixed with fuel oil and air and burned in an
incinerator situated between the ovens.  The heat is recovered from the
incinerator and is used for heating the flue system.  The coking cycle lasts
from 40-48 hours.  The system is under 0.95 inches of water vacuum with outside
air drawn through the trunnel head (coal charge points) on top of the ovens.
The coke is removed from the ovens into an enclosed quench wharf and the gases
are exhausted and burned in the incinerator.  Tests conducted on emissions
from this unit show 0.052 grains per standard cubic foot of air of particulate
matter and 252 ppm of sulfur dioxide burning 0.7 percent sulfur coal.  The
test unit has been approved by the state regulatory agency, and four commercial
development units at mine-mouth locations are in the planning stage.
                                    -32-

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                                    SECTION 4
        MATERIAL BALANCE AND WASTE CHARACTERISTICS OF COKE OVEN PROCESSES

BYPRODUCT COKE OVEN PROCESS
Typical Product/Byproduct Quantities
     The quantity and characteristics of the coke product and chemical
byproducts vary with coal types, oven temperatures, and operating conditions.
Using the coal composition and operating conditions specified in Section 3
under "Coal Handling and Preparation," literature information shows that one
ton of coal (wet and as fed to the oven) will yield 1,935 pounds of products
and byproducts with the following typical slate:
                              Pounds                                  Pounds
          Coke                1,430        Ammonia, anhydrous            5
          Coke Breeze            93        Light Oil  (2.81 gal)         20
          Tar (8.41 gal)         78        Gas  (10,350 scf)            309
     The remainder (65 Ib) is assumed to be composed  of condensed moisture and
pollutants (e.g., particulates, phenolics) in the process wastewater and in
the fugitive air emissions.  The foregoing assumption needs verification,
since literature data were not definitive regarding these losses.
     The following summary of clean coke-oven gas composition is typical:
                                                        Volume %
          Constituent
               co2
               C H
                n m
               CO
               H2
               C_ and homologs
               N2
               0,,
                                     -33-
Typical
2.5
3.5
8.0
53.5
30.0
2.0
0.5
Ranges
1.3 -
3.1 -
4.5 -
46.5 -
26.7 -
1.5 -
0.2 -
2.5
4.0
9.0
57.9
34.0
9.6
0.9

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     Table 4-1, a detailed breakdown of the feed coal into various products,
byproducts and contaminants, shows that the feed coal contains about 1.0 percent
sulfur; and the product coke contains about 0.96 percent sulfur.  The balance
of the sulfur converts principally to hydrogen sulfide, carbonyl sulfide and
carbon disulfide in the raw coke-oven gas.

Waste Characteristics
Process Wastewater—
     The principal sources of byproduct coke plant process wastewater before
treatment are ammonia liquor blowdown, final cooler blowdown water, light oil
plant wastewater:  25 gallons, 25 gallons, and 30 gallons, respectively, per
ton of coke for the plant utilizing the best available technology  (BAT).
Barometric condenser water is also a potential source when a crystallizer is
used for ammonium sulfate production.
     Table 4-2 presents typical pollutant concentrations in the ammonia liquor
blowdown.  The blowdown rates range from 18 to 90 gallons per ton  of coal (dry
basis) depending on the type of process used to remove ammonia from the coke
oven gas.  The Phosam-W and sulfuric acid scrubbing processes exhibit lower
flows; higher flows occur with the outdated water scrubbing process.
     Final cooler blowdown water represents the condensate resulting from
cooling the saturated gas with direct contact cooling water.  Typical pollutant
concentrations in the blowdown are shown in Table 4-3.  The quantity of con-
densed water ranges between 5 to 10 gallons per ton of coal (dry)  and is one
of the major sources of hydrogen cyanide in wastewater.
     Table 4-4 shows representative pollutant concentrations in the light oil
plant (also called benzol plant) wastewater.  The volume of water  generated
from these sources ranges from 18 to 56 gallons per ton of coal (dry).
     Plants with a crystallizer for ammonium sulfate production generally use
barometric condensers that create large amounts of wastewater, ranging  from
175 to 300 gallons per ton of coal (dry).  Pollutant concentrations repre-
sentative of barometric condenser water are:
          Constituent                   mg/1
             Ammonia                     20
             Phenol                      40
             Cyanide                     40
             Oil                         20

                                     -34-

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   TABLE 4-1.
YIELDS AND ANALYSES OF PRODUCTS OF BY-PRODUCT  COKE  OVEN PROCESS
                   (SOURCE - BIBLOGRAPHY  51)
Product
Coke
Gas
Ammonia
Tar
Liquor
Light Oils
Cyanogen
Carbon disufide
Hydrogen sulfide
Percent of
coal
Constituent by weight
Ash
Carbon
Hydrogen
Sulfur
Nitrogen
Totals
CO
CO
CH
N2 4
"I
Totals
Hydrogen
Nitrogen
Totals
Carbon
Hydrogen
Oxygen
Totals
Water
Organics (phenolics)
Totals
C,H, (Equivalent)
b o
cs2
7.210
61.711
0.469
0.683
0.270
70.343
1.042
3.154
7.468
1.529
0.385
1.366
0.717
15.661
0.040
0.183
0.223
4.687
0.327
0.436
5.450
6.78
0.025
6.805
1.102
0.078
0.013
0.325
Analysis
percent of product
by weight
10.24
87.76
0.66
0.96
0.38
100.00
6.66
20.14
47.69
9.76
2.46
8.72
4.57
100.00
17.9
82.1
100.0
86.0
6.0
8.0
100.0
99.63
0.37
100.0
100.0
100.0
100.0
100.0
                                               100.00
                                     -35-

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                TABLE 4-2.  AMMONIA LIQUOR BLOW-DOWN COMPOSITION
                                 (SOURCE:  BIBLIOGRAPHY 7)
Constituents
Concentration Range
Total ammonia, mg/1 as N
Free ammonia (% of total)
Fixed ammonia (% of total)
Oil and grease, mg/1
Sulfide and Sulfite, mg/1 as S
Sulfate, mg/1 as SO,
Chloride, mg/1 as Cl
Cyanide as HCN, mg/1 as CN
Thiocyanate, mg/1 as CNS
Phenols, mg/1
COD, mg/1
Solids - total, mg/1
Solids - suspended, mg/1
3,000
20
40
500
500
200
2,000
20
300
500
8,000


9,000
60
80
2,000
2,000
800
6,000
100
- 1,200
3,000
- 16,000
Unknown
Unknown
                                     -36-

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     TABLE 4-3., FINAL COOLER WATER SLOWDOWN  COMPOSITION
                         (SOURCE:   BIBLIOGRAPHY 7)


Constitutents                         Concentration Range
Annnonia-N, mg/1                            200  -    400
Phenols, mg/1                              500  -  1,500
BOD5, mg/1                               2,000  -  3,000
COD, mg/1                                3,000  -  4,000
TOC, mg/1                                  800  -  1,400
Cyanide (CN), mg/1                         100  -    300
Sulfide (H2S), mg/1                         10  -     40
Thiocyanate (CNS), mg/1                    200  -  1,000
Solids - total, mg/1                       200  -    700
Solids - suspended, mg/1                    20  -     60
Oil, mg/1                                   10-40
PH                                           7  -      9
                           -37-

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TABLE 4-4.  LIGHT OIL PLANT (BENZOL) PROCESS WASTEWATER COMPOSITION
                           (SOURCE:  BIBLIOGRAPHY 7)

        Constitutents                        Concentration Range
        Ammonia-N, mg/1                          10  -    100
        Phenols, mg/1                            60  -    200
        BOD5, mg/1                              300  -    600
        COD, mg/1                               500  -  1,000
        TOG, mg/1                               200  -    600
        Cyanides, mg/1                           10  -     60
        Solids-total, mg/1                      200  -    700
        Solids-suspended, mg/1                   30  -     70
        Oil, mg/1                                10  -    200
        pH                                        5-8
                              -38-

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     In plants that remove hydrogen sulfide from the gas, fouling of the
absorber solution is another source of contaminated wastewater.  The volume of
water generated from this source can range from 0.3 to 12 gallons per ton of
coal (dry) depending on the removal process employed.
     Concentrations representative of the effluent wastewater from a vacuum
carbonate desulfurization process are:
          Constituents             Concentration
          Ammonia, mg/1                   50
          Phenol, mg/1                     5
          Cyanide, mg/1                1,200
          Sulfide, mg/1                   30
          BOD5, mg/1                   1,200
          COD, mg/1                    1,700
          TOG, mg/1                      700
This effluent wastewater is usually recycled to the coke quenching station for
reuse.
     Coal pile runoff, another major wastewater stream from coke oven plants,
has characteristics that depend on the type of coal stored.  Typical wastewaters
from the two types of coal generally stored in the coke oven industry are:
                              High Volatile,           Low Volatile,
                              Bituminous               Bituminous
                                 (38% V.M.)                (17% V.M.)
          pH                    6-7                  2.5-7
          Suspended Solids    600 - 14,000 mg/1        100 - 1,000 mg/1
                              Avg.  10,000 mg/1        Avg.    500 mg/1
     Other miscellaneous wastewaters originate from the  following:
          a.   Pump and compressor seal water
          b.   Floor washdowns
          c.   Tank washings
          d.   Spills
          e.   Rain water runoff from process and storage areas
          f.   Wastewater from steaming or flushing of piping  and equipment.
                                     -39-

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Air Emissions—
     In the Byproduct coke plants, the majority of the air emissions emanate
from the coke oven (including quenching) operations and consist of two types:
fugitive losses, and stack emissions from the fuel burning operation (under-
firing) at the coke ovens.  Table 4-5 gives the quantities of air emissions
from the coke ovens and quenching operations per ton of coal charged.  These
emission factors were developed by the EPA based on data gathered prior to
1972.  Since that time, more extensive data have been acquired by the EPA.  It
is expected that additional pollutant factors (e.g., benzene soluble organics)
may be added or others modified in the table in the near future.  The calcu-
lated sulfur dioxide (SO ) emissions in Table 4-5 are based on the assumption
that the coke oven gas has not been desulfurized prior to the underfiring
operation.  However, many coke plants are using cleaner fuels for underfiring.
     Besides the coke ovens, small amounts of fugitive emissions (containing
smoke, particulates, hydrocarbons, etc.) emanate from all other unit operations/
processes of the Byproduct Coke plants.  Quantitative information on these
losses is not available from the literature.
     The types of fugitive emissions found in the unit operations/processes
are as follows:
          Unit Operation/Process
          Coal Pile
          Coal Handling and Preparation
                                        Contaminant
                                        Particulates
                                        Particulates
Coke Ovens (Fugitive and Underfiring)   Particulates, So , CO, H-C,
   including Quench Station                NO , NH» (see Table 4-5)
                                        Particulates
                                        Odors (NH~» organics)
          Primary Cooler
          Tar Separator, Exhauster and Tar
             Extractor
          Ammonia Removal
          Fine Cooler, Naphthalene
             Skimmer basin
          Light Oil Recovery, Light Oil
             Refining
          Gas Compressor, H2S Removal and
             Sulfur Recovery.
                                        Particulates, H2SOA
                                           and NH~
                                        Odors
                                        Particulates, odors
                                        Particulates, H S, S0~
                                    -40-

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TABLE 4-5.  UNCONTROLLED AIR EMISSIONS FROM COKE OVENS/QUENCHING OPERATIONS
Stream
Charging
Coking Cycle
Pushing/Discharging
Quenching
Underfiring
     TOTAL:
                                   Air Emissions, Lbs.*
Participates
SO.
 CO
Hydrocarbons
NO
    3.1
4.02
1.27
    4.2
                                                x
0.04
Ammonia
1.5
0.1
0.6
0.9
-
0.02 0.60
0.60
0.07
-
4.0 **
2.5
1.5
0.2
-
-
0.03
0.01
-
-
-
0.02
0.06
0.10
-
-
  0.18
* Based on one ton of coal input to the coke ovens.
**Coke oven gas before desulfurization is used for underfiring the ovens.
1 "Compilation of Air Pollutant Emission Factors", 3rd Edition, EPA-AP 42.
                                      -41-

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Solid Wastes—
     Solid waste sources from the Byproduct coke oven plants are:
     a)  Coke breeze from coke sizing and screening, quenching operations.
         About 70 to 100 pounds per ton of coal charged to the ovens are
         converted to coke breeze with the following typical composition:
                                             Range (wt. %)
               Volatile Matter                 4    -   6
               Fixed Carbon                   76    -  80
               Ash                            10    -  20
               H20                             0.5  -   5.0
          Coke breeze has an economic value, and is sold or reused in many
          installations.
     b)   Coal particulates from coal pile run-off wastewater treatment.
          Recovered coal from the coal pile runoff could be returned to the
          coal pile for reuse.
     c)   Solid wastes from process wastewater treatment  (from biological
          treatment system and ammonia stripping unit).  Biological treatment
          systems yield about 7.6 pounds of dry solids per ton of coal fed.
     d)   Residue in the form of tar sludge generated from tar decanting in
          the tar separator.  About 3.3 pounds of tar sludge per ton of coal
          fed is periodically removed as a solid waste from the tar storage
          tank.

Material Balance of a Typical Byproduct Coke Oven Plant
     To assess the quality and quantities of products, byproducts and wastes
generated from an average coke oven plant, a 5,000 TPD (coal input) plants was
selected as a typical model.  The material balance basis of the above plant is
summarized in Table 4-6.  Many of the major design assumptions including yield
and analyses of different products are taken from the literature.  Figure 4-1
and Table 4-7 depict the block flow diagram and overall material balance for
the 5,000 TPD coke oven plant, respectively.
     Tables 4-8 and 4-9 provide a summary of the air emissions and wastewater
effluent from the 5,000 TPD model coke oven plant.
                                     -42-

-------
       TABLE 4-6.  DESIGN BASIS FOR A  5000 TPD  BYPRODUCT  COKE OVEN PLANT
    Coal Type
    Coal Moisture:
    Sulfur Content:
Bituminous Mixture
4.0% by wt.
1.0% by wt.
    Coke Ovens Operating Conditions
       Batteries:
       Coke Ovens  per battery:
       Coal charge per oven:
       Coking cycle:
       Temperature:
       Underfire excess air:
3
85
20 tons
17 hours
900°C
6%
3.   Yields
    Products,  byproducts,  % wt. coal (volume, scf/ton of coal)
       Coke                                                 70.343
       Tar                                                   5.45
       Light Oil                                             1.102
       Ammonia                                               0.223
       Coke Oven Gas                                        15.661  (12,000)
       Water (Liquor)                                        6.805
       Other Gases                                           0.416
4.  Raw Coke Oven Gas Composition
    % wt.  of coal feed:

       H2

       N2
       co2

       CO

       CH4

       C2H4

       °2
       NH3

       Tar
       C,.H, (equiv)
        b o
       cs
       Phenol (organics)
 1.366

 0.385

 1.042

 3.154
 7.468

 1.529

 0.717

 0.223

 5.45

 6.776

 1.102

 0.078

 0.013

 0.325

 0.029
                                     -43-

-------
                              TABLE 4-6 (Continued)
5.  Quench Water
       Feed Rate:                                           500 gallons per ton
                                                                    of coke

       Evaporation Rate:                                     35%


6.  Weak Ammonia Liquor
    Recycle Rate, gal/ton of coal                         1,430


7.  Wash Oil Recirculation Rate in the                      15°
    Light Oil Recovery Unit, gal/ton of coal


8.  75% of the total naphthalene in the coke oven
    raw gas is recovered from the final cooler
    skimmer basin.


9.  Overall Sulfur Removal                                   90%
    Through the Vacuum Carbonate System
                                     -44-

-------
                               HOT COKE OVEN GAS
                              f
              FUGITIVE EMISSIONS
COAL HANDLING
 PREPARATION
<£>
                            COKE OVENS
                           X"
                COMBUSTION
                  •''5s
                   •&'
                   AIR
                                   -*-  TO  PAGE 2





                                             FLUE GAS
                                                     UNRECOVERED COKE

                                                 BREEZE a EVAPORATED WATER
                                                          <1>>
                                                          >v-
                                          HOT COKE
                                                          1
QUENCH


STATION
^QUENCHED

"  COKE
                                               RECYCLE
                                                QUENCH
                           QUENCH WATER   RECOVERED COKE BREEZE

                                         a SPENT QUENCH WATER
                                      .  RECYCLE COKE-OVEN GAS
                                     +—	FROM  PAGE  4
   Figure 4-1 (Pg. 1 of 4).  Detailed block^flow diagram of a byproduct coke oven plant.

-------
   RECYCLE AMMONIA LIQUOR (TO SPRAYS)
/£s HOT COKE OVEN ^
S/ GAS.FROM
PAGE 1
COAL TAR < 	
TAR SLUDGED
8.3 TPO ~"
1

COLLECTING MAIN
a
PRIMARY COOLER
i
t

CONDENSED '
TAR
i
TAR
SEPARATOR
/ftv
1
i
LIQUOR
STORAGE

i
1
^C rvHAiiCTri) fc ELECTROSTATIC _ 	 	 _v_ 	 ^.70 RFHEATFR
*. EXHAUSTER + PRECWTATOR PAGES
<$>
ADDITIONAL TAR PARTICLES
i
WASTEWATER <^> pHpNQL ^ ^ T0 NHs STILL
w REMOVAL PAGE 3
                                       SODIUM PHENOLATE
Figure 4-1 (Pg, 2 of 4).  Detailed block flow diagram of a byproduct coke oven plant,

-------
                  SULFURIC
                   ACID
                                    EVAPORATED WATER
                                                                                            EVAPORATED WATER,350 TPD
                                                                RECYCLE COOLING WATER
                                                                   COOLfNG
                                                                    TOWER
      FROM PHENOL REMOVM,
      PAGE a
                                                        FINAL
                                                       COOLER
                                            MAKE-UP
                                             WATER
AMMONIUM SULFATE
                                -25 % AMMONIA VAPOR
                                                                    WATER
                                     NAPHTHALENE
                                                     COKE OVEN GAS
                                                 TO WASH OIL SCRUBBER,
                                                     PAGE  4
LfVE STEAM
          EFFLUENT DISCHARGE
 NAPHTHALENE
SKIMMER BASIN
                                                                                  WASTEWATER SLOWDOWN
                                                                                  RECYCLED TO COKE
                                                                                  QUENCHING
                          , MAKE-UP WftTER
                                                                                                                256 TPD
                                                                             NAPHTHALENE (8 TAP
                         Figure 4-1  (Pg.  3  of 4).   Detailed block flow diagram  of  a  byproduct coke oven plant.

-------
                  COKE OVEN GAS FROM FINAL COOLER  PAGE  3
     WASH OIL
     SCRUBBER
   (VACUUM
CARBONATE)
                       I
                        MAKE-UP
TO COKE OVENS
PAGE 1
          v   |No2C03
     H2S ABSORBER/i
        ACTIFIER/  |
    STEAM EJECTORS
 CLEAN COKE OVEN
      GAS
               WASTEWATER RECYCLED
               TO COKE QUENCHING
WASH  OIL
STRIPPER
                                            . i w CTPAM
                                            LIVE STEAM
                                                    GAS
CONDENSERS/
SEPARATORS
                                                                             LIGHT
                                                                              OIL
                     - DECANTED  WASTEWATER
                     WASH OIL   RECYCLED TO COKE
                                QUENCHING
                                -fr-SULFUR
                        CLAUS      I3.24TPD
                        PLANT
                                                                      TAILGAS
       Figure 4-1 (Pg. 4 of 4).  Detailed block flow diagram of a byproduct coke oven plant.

-------
Coal or Coke
Tar
Light Oil
Ammonia
Water
CO
H2
CH/i
02
C2N2
CS2
H2S
Cyanides
Phenol
Napthalene
Wash Oil
Na2C03
Others

TOTAL
                                        TABLE 4-7  MATERIAL  BALANCE 01' A 5000 TI'D COKE OVEN PLANT

                                                                     FLOWS,  TPD
1

Coal From
Handling
4,800



200.0












2

Fugitive
Emissions

5.5

0.45

3.18



8.7
1.8






3

Hot Coke
Oven Gas

267.0
55.1
10.6
338.95
154.5
68.3
19.2
52.1
364.6
74.7
35.9
3.9
0.7
16.2

1.25
4 5
Recycled
Hot Coke Oven
Coke Gas
3517.2



16.92
61.8
27.32
7.68
19.33
145.84
29.88
14.36
0.64
0.28
0.65
Trace
Trace
6 7

Combustion Flue
Air Gas




631.07


3233.4 3241.04
614.9

55.3
985.9





5,000
              0.15
19.8
                                                                                                           Quencher!
                                                                                                              Coke
                                                                                                            3264.9
                                                                                          101.0
                                                                                                                 10

                                                                                                                Total
                                                                                                                Quench
                                                                                        2915.0
                                                                                       7325.0
                                                                                                                Trace
                                                                                                                Trace
1463.0
3517.2
                                                324.7
                                                4219.3
                                                                            4544
                                                                            3365.9
                                                                                                     2915.0
                                                                                                   7325.0
                                                                                                                        (continued)

-------
                                                           TABLE 4-7.   (Continued)
                        11
                 12
               13
                                                              14
                                                       15
                                                        16
                                                                                  17
                                                                  18
                                                              19
                                                             20
                                                     21
Coal or Coke
Tar
tight 0:1
Amonla
Water
CO
H2
N2
O>2
CH*
02
C2N2
CS2
H2S
Cyanide*
Phenol
H2S04
Unrecovered
Coke Breeze
and Evapo-
rated Water
2.3



2,564.0










Recovered
Coke Breeze C.O.C.
and Spent Condensed to
Quench Water Tar Exhauster
2SO.O
244.13 22.87
2.8 52.3
309.65 7.95
250.0 29.729.4 82.5
154.5
68.3
19.2
52.1
364.6
74.7
35.9
3.5
0.7
16.2

C.O.C. Additional
To Electro- Tar Coal
Static Preclp. Particles Tar

2.29 22.85 258.69
52.3 2.8
7.95 0.06
82.5 5.45
154.5
68.3
19.2
52.1
364.6
74.7
35.9
3.5
0.7
16.2

Liquor Liquor Liquor
to Recycle to
Storage Liquor Phenol NH Still



309.59 307.0 2.59 2.59
29.723.9 29.473.0 250.9 250.9










                Trace
                Trace
              40.49
              89,32
                  0.50
             0.50
                  0.75
                                                    40.49
                                                    89.32
                                                                                40.15
                                                                                88.57
                                                               0.34
                                                               0.75
                                                                                                                            0.34
Napthaleoe
Waah Oil
 Others

 TOTAL
2,566.3
500.0
30,415.8
955.8
935.2
23.60
267.0
30,163.3    29,908.7    254.6
                                                                                                                            253.8
                                                                                                                           (continued)

-------
                          22
                        Sodium
                        Phenolate
                                  23

                                C.O.G.
                                 to
                                Reheater
                                             24

                                            C.O.G.
                                             to
                                            NH,.  Removal
                                                                  TABLE 4-7.   (Continued)

                                                                   25           26          27
Steam to
   NH
Still3
Uastewater
   From
NH, Still
25% Nil
 to NH§
Removal
                                                                                                 28
  to
NH. Removal
                                                                                                                      29
Makeup
    to
    Removal
H20
                                                                                                                                 30
Ammonium
Sulfate
                                                                                                                                                    31
Evaporation
H20 from NH3
Removal
 I
Ui
H
     Coal or Coke
     Tar
     Light Oil
     Ammonia
     Water
     CO
     H2
     N2
     C02
02
C2N2
CS2
H2S
Cyanides
Phenol
H2SO/,
                          0.75*
0.02
52.3
7.95
82.5
154.5
68.3
19.2
52.1
364.6
74.7
35.9
3.5
0.7
16.2
0.02
52.3
7.95
82.5
154.5
68.3
19.2
52.1
364.6
74.7
35.9
3.5
0.7
16.2
                                   0.50
Napthalene
Wash Oil
Na2C03
Other*

TOTAL                0.75        933.0

*Phenol content of sodium phenolate
                                                      0.50
                                                    933.0
                                                             42.25
                                                                          0.03
                                                                        285.45
                                                                                        2.57
                                                                                        7.70
                                       10.00
                                          254.8
                                           0.04
                                                                                   9.95
                                                                                0.34
                                                                                                       29.99
                                                                   42.25
                                                                               285.82
                                                                                             10.27
                                                                                                  39.99
                                                                                                                       254.8
                                                                                                                                     40.39
                                                                                                                                     40.4
                                                                                                                                      (continued)
                                                                                                                                                    9.95
          ** About 50 mg/1 free cyanide and the remainder as thiocyanates.

-------
                                       TABLE 4-7.  (Continued)
  32

C.O.C.
co Final
Cooler
    33

Water &
Naphthalene
Final Cool
     34

Naphthalene
     &
    Tar
    35
Waatewater
Slowdown
   36

Recycle
Cooling Water
to Final Cooler
  37

C.O.C.
to Wash Oil
Scrubber
    38

Light Oil
    to
Stripping
     39

Live Steam
to Light Oil
Stripper
Tallgaa
                                                                                  41
Recycled
Wash Oil
Coal or Coka
Tar
Light Oil
Aononla
Wacar
CO
H2
N2
C02
CH4
r-iH/i
02
C2N2
1 CS2
J-n H2S
1 Cyanldaa
Phenol
H2SOA
(HU4)2S04
Napthalana
Utah Oil
Othara
TOTAL

0.02
52.3
0.11
345.0
154.5
68.3
19.2
52.1
364.6
74.7
35.9
3.5
0.7
16.2

0.50





1187.63

0.02

4.04
11,130.










3.3
16.5


0.91


1154.9
                           0.02
                            0.98
                           1.0
                                          0.11
                                        209.
                                                 3.93
                                             10827.0
                                          0.09
                                          0.45
                                                 3.22
                                                16.1
                                                                        51.32
                                                                        42.30
                                                                       154
                                                                        68
                                                                        19
                                                                        52
                                              364.6
                                               74.7
                                               35.9
                                                3,5
                                                0.7
                                               16.2

                                                0.05
                                                             53.96

                                                            250
                                                                                                                 5.2
                                                             250
                             209.65
                               10850.25
                                883.27
                                                0.02
                                                0.05
                                                                                    2602.44
                                                                                    2906.47
                                                                                         250
                                                                                     31.1
                                                                                                              2602.44
                                                                                                                         2607.64
                                                                                                               (continued)

-------
                                                                TABLE  4-7.   (Continued)
                              42
                        Light Oil  to
                        Condenser/
                        Separators
                  43
              Light  Oil  from
              Condenser/
              Separators
                      44
                Wash Oil from
                Condenser/
                Separators
     45              46
Uastewater from    C.O.G.
Condenser/          to
Separators 	    112S
  47       48

          Acid
Na2C03    Gas
                   49
                 Waste-
                 Water
                 from H2S
             50

            Clean
            C.O.C.
51
                                                                                                                      Product
 I
Ul
     Coal or Coke
     Tar
     Light Oil
     Ammonia
     Water
     CO
     H2
     N2
     C02
     02
     C2N2
     Cyanides
     Phenol
     H2S04
     Napthal^ne
     Wash Oil
     N82C03
     Other*

     TOTAL
 48.76

250.00
  0.02
  0.05
  2.44
                           301.27
48.76
                                     250
                                       0.02
                                       0.05
                48.76
                    2.44
                    2.44
    250.07
                     2.57

                    42.30
                                                                    154.
                                                                     68.
                                                                     19,
                                                                     52.
                                                                                                74.
                                                                                                35,
                                                                                               364.6
                                                                      3.4
                                                                      0.7
                                                                     16.2
                   Trace
                                                                    834.47
7.3
                                                                         3.78
                                                                                                                   14.58
                                                                                                                    1.54
                                                                                0.27
                                                                7.57     19.9
  2.57

232.3
                                                   0.28
                                                  Trace
                                                   0.27


                                                 235.42
42.3
154.5
68.3
19.2
52.1
364.6
74.7
35.9
1.58
0.7
1.62
25.38
92.7
40.98
11.52
32.76
218.76
44.82
21.54
0.95
0.42
0.97
                                                                                                             815.5
                                       490.8

-------
                        TABLE 4-8  SUMMARY OF AIR EMISSIONS - 5000 TPD BYPRODUCT COKE OVEN PLANT

                                                  (Emissions are in tons per day.)
Ln
f
Stream

Fugitive Emissions

Flue Gas

Unrecovered
  Coke Breeze and
  Evaporated Water

Evaporated Water
  (Cooling Tower
   & Others)

Claus Tail Gas

Totals
                         Total Flow  Partlculate
                           (TPD)       Matter
                                              SO,
                               CO
H-C
                    NO
                              19.8

                            4544
           5.5 (Tar)
0.05  3.18  10.52  0.10

1.69        55.3
                            2566.3**  2.3 (Coke
                                          Breeze)
  360.0



   31.103

7,521.203  7.8
0.096

1.836 3.18  65.82  0.10
NH3


0.45
                                                                             0.45
                    614.9    3241.04     631.07

                                        2564.0



                                         360.0



                      5.32     25.508            .179*

                    620.22  3,266.548  3,555.07  .179
      * Includes  .015 and 0.096 TPD of CS~ and COS, respectively.
     ** Fugitive  emissions from cooling tower and coke quenching with contaminated water may lead to
        substantial air pollution problem.  The quantity of these pollutants has not been ascertained.

-------
TABLE 4-9.  SUMMARY OF PROCESS WASTEWATER - 5000 TPD BYPRODUCT COKE OVEN PLANT
                           (Wastewater Contaminants, tons/day)
Stream No.
20
35
45
49
Totals
Total Flow
(TPD)
254.58
209.65
250.07
232.58
946.88
Water
250.9
209.0
250.0
232.3
942.20
Phenol
0.75
0.45
0.05
Trace
1.25
Cyanides
0.34
0.09
0.02
0.28
0.73
Ammonia
2.59
0.11
-
-
2.7

-------
     Solid wastes quantities generated by the model plant are the following
(water free basis):  250 tons/day coke breeze; 8.3 tons/day of tar sludges;
and 19 tons/day of bio-sludges.
Process Description—
     Bituminous coal containing about 30 percent volatile matter and 4 percent
water is crushed to about 1/8-inch size in a hammer mill and then fed to the
coke ovens.  Three batteries of coke ovens, each battery containing 85 ovens,
are provided.  Coking temperature and cycle are 900 C and 17 hours, respectivelj
At the end of the coking cycle, hot coke is quenched with water in a quench
station.
     From the coal handling, preparation and coke oven operations, approximately
19.8 TPD of fugitive emissions are lost to the atmosphere.  In the quenching
operation, 2.3 TPD of fine coke breeze is emitted to the atmosphere as well as
large amounts of evaporated quench water.
     During coking of the coal, raw coke oven gas is evolved containing a
mixture of gases, entrained solids, various products and pollutants such as
cyanide, hydrogen sulfide and phenol.
     The crude gas leaves the ovens through standpipes and passes into a gas
collecting main.  There, the temperature of the gas is reduced from approxi-
mately 800 to 1,300°F to about 175 to 200°F by spraying with recycled ammonia
liquor.  This reduction in gas temperature causes condensation of approximately
75 percent of the tar in the gas together with a small portion of ammonia.
The condensed ammonia appears as excess ammonia liquor, which is sent to an
ammonia stripping operation.
     From the collecting main, the gas passes to the primary coolers where it
is cooled to about 85 to 104 F by ammonia liquor spray.  This cooling removes
additional tar, and again, a small portion of the total ammonia in the gas.
The gas is next conducted to an exhauster (positive displacement type) which
serves not only to compress the gas but also to remove tar by the high-speed
swirling motion imparted to the gas.
     The gas passing through the exhausters still contains traces of tar fog
which is further reduced by electrostatic precipitators.  The tar drains from
the bottom of the precipitators into a settling pit which also collects the
tar removed from the collecting main and primary coolers.  It is then pumped

                                     -56-

-------
from the pit and transferred to a storage tank where excess water is decanted.
This tar, containing about 2 percent moisture, is sold to chemical companies
for processing and recovery of valuable aromatic compounds.
     The excess ammonia liquor which results from gas cooling in the collecting
main and primary coolers is pumped from liquor storage to a phenol removal
unit.  Here, phenol is extracted from the liquor through use of a solvent such
as a light oil fraction, and recovered as sodium phenolate by treatment with
caustic.
     The liquor is then sent to an ammonia stripping unit, where ammonia is
removed by contact with live steam.  The stripped liquor is discharged to
waste treatment (physical/chemical or biological), and the vapor stream,
containing 25 weight percent of ammonia, joins the detarred coke oven gas
stream in entering the ammonia removal unit.
     In the ammonia removal unit, the combined gas stream  flows  through an
absorbent tower into which is sprayed a dilute sulfuric acid solution.  The
sulfuric acid reacts with the ammonia to produce ammonium  sulfate.  The
ammonium sulfate eventually reaches  a saturation point in  the solution, and
begins to crystallize.  The crystal  slurry is pumped to a  centrifuge, where a
cake is produced and dried in a rotary drum  dryer to about a 0.1 weight percent
moisture content.
     In some plants, a crystallizer  is equipped with a barometric condenser
which uses a large quantity of water.  An example of this  process is  the
Wilputte process.
     After the ammonia removal unit,  the gas passes  through  the  final coolers
where direct contact water is used to cool the gas  to a  temperature of  70  to
90 F.  A major portion of the naphthalene condenses  out  of the gas  due  to  this
cooling.  The naphthalene is recovered from  the  cooling water at  the  settling
basin where it is skimmed off as  it  rises to the  top.  It  is either added  to
the  tar or is processed  further to produce a commercial  product.
     The cooled coke oven gas is  scrubbed with a  petroleum wash  oil.  The  gas
comes in direct contact  with the  wash oil in one  or  more scrubbing  towers
containing packing and  interlocking  sprays.   The  flow of gas and wash oil  is
counter-current in each  tower, and counter-current  over  the  entire multi-tower
system.  The wash oil absorbs  the light  oil  so that  the  benzolized wash oil
contains 2  to 3 percent  light oil.   From 90  to 95 percent  of the light  oil
content  of  the gas is recovered  in this  operation

                                    -57-

-------
     The wash oil is debenzolized by steam distillation.  The carryover of
wash oil into the light oil is kept to about 5 percent and the debenzolized
wash oil contains 0.2 percent light oil.  The mixture of light oil and steam
exists the top of the stripping column, is condensed, and separated.  The
light oil is sent to the Houdry LITOL process for refining of benzene and
other components.
     The gas, after being stripped of light oil, is next sent to the desulfur-
ization unit for sulfur removal.  Many desulfurization processes are available,
however, the Vacuum Carbonate process has moved into commercial prominence.
     In the Vacuum Carbonate process, the gas is contacted counter-currently
with a solution of sodium carbonate in an absorber tower to remove the hydrogen
sulfide and other impurities such as hydrogen cyanide.  The foul solution from
the base of the absorber is circulated over the actifier where the hydrogen
sulfide is removed by counter-current stripping with water vapor under vacuum.
The actified solution is pumped from the base of the actifier through a cooler
to the absorber to complete the cycle.  The acid gas, Stream No. 48, is sent
to ,a Claus plant for sulfur recovery.
     After desulfurization, approximately 40 percent of the product gas is
returned to the coke ovens as a fuel source.

OTHER COKE OVEN PROCESSES
Beehive Process
     The only product recovered from the Beehive ovens is the coke itself.
Approximately 1,200 pounds of coke per ton of coal are recovered.
     Raw waste loads from the Beehive oven are a function of coking time,
water use systems, moisture and volatility of the coal, and carbonizing
temperature of the ovens.  However, the raw waste is affected most by the type
of water use systems, that is, once-through or recycle.  Table 4-10 summarizes
the net plant raw waste load from three selected plants.  Raw waste loads are
presented only for the critical parameters which include ammonia, BOD,-,
cyanide, phenol and suspended solids.
     For the Beehive coke plant, the majority of the emissions emanate from
the oven door during watering-out and drawing of the coke.  The estimated
nature and quantity of these emissions based on one ton of coal input are:
                                    -58-

-------
  TABLE 4-10.  CHARACTERISTICS OF BEEHIVE COKE PLANT WASTES
                       (Net Plant Raw Waste Load) —
Characteristics                           Plants
                                     I        1      1
Flow, 1/kkg                    2,040       2,040    513
Ammonia, mg/1                      0.33        0      0
BOD, mg/1                          3.00        0      0
Cyanides, mg/1                     0.002       0      0
Phenol, mg/1                       0.011       0      0
Suspended Solids, mg/1                 -      29    722
1^ Data obtained from Bibliography 21.
                            -59-

-------
          Particulates     -  200 Ibs
          Carbon Monoxide  -    1 lb
          Hydrocarbons     -    8 Ibs
          Ammonia          -    2 Ibs

 Low Temperature Processes
     In low temperature coke manufacturing applications, the main objective is
to obtain maximum yields of liquid products and semi-cokes containing from 8
to 20 percent volatile matter.  Here again, the characteristics and yields of
the various products and byproducts depend upon the coal, the temperature and
the treatment.
     One ton of coal would yield on an average the following products and
byproducts:
                                        Pounds
          Semi-coke (char)               1,440
          Tar (15.8 gal)                   150
          Ammonia, anhydrous                 5
          Light oil (2.5 gal)               16
          Gas (3,720 scf)                  250
                                         1,861
     The balance (139 Ibs) probably consists mostly of condensed moisture,
small amounts of pollutants (e.g. particulates, phenols) in the process
wastewater and the fugitive air emissions.  However, this assumption needs
verification, since the data varies among different references in the
literature.
     The typical clean gas composition is as follows:
               Constituent              Volume %
               Co2                         9.0
               C H                         8.0
                n m
               CO                          5.5
               H2                         10.0
               CH,  and Homologs           65.0
               N2                          2.5
     No information on the wastewater and air emission was available from the
literature reviewed.   There is no commercial or developmental low temperature
coke oven process in the United States.
                                     -60-

-------
                                    SECTION 5
           COAL GASIFICATION PROCESSES AND THEIR WASTE CHARACTERISTICS

COAL GASIFICATION PROCESSES
     In contrast to coke oven gas which is produced from distillation
(carbonization) of coal, coal gasification process gases are produced by a
combination of the following mechanisms:
               Distillation of coal by heating;
               Reaction of solid coal with oxygen and steam; and
               Reaction of various intermediate gases.
     Four principal chemical reactions occur in a gasification reactor:
                                                     Standard Enthalpy Change
                                                     	@ 1,200°K	
          (1)  C  +  HO   *      »T  CO  +  H          - 32,457 cal/g.mol
          (2)  CO +  H20   «      »  C02 +  H2         +   7,838  "  "  "
          (3)  C  +  2H2   «,      »  CH4               + 21,854  "  "  "
          (4)  C  +  1/2 02   *"   »  CO                + 26,637  "  "  "
     Reaction (3) demonstrates the  formation of methane, which is favored at
low temperatures (below 1,000 F) and high pressures.  High  temperature and low
pressure gasification processes  (e.g., K-T process) do not  produce much methane
in the gasifier reactor.
     Besides the above four reactions, other chemical reactions and devolatil-
ization of coal in the gasifier  result in the formation of  byproducts and
trace pollutants, such as:
          Gases containing reduced  sulfur compounts - (H_S, COS, CS?, etc.)
          Gases containing nitrogen compounds -  (NH_, HCN,  etc.)
          Hydrocarbons
          Heavy metals/trace  contaminants.
                                       -61-

-------
     Most of the above mentioned byproducts and pollutants are also found in
the coke oven raw gases.
     Approximately 68 different gasification processes have been used
commercially in the past or are currently under development.  Most of these
systems, however, were retired or did not achieve commercial status because of
the availability of less costly natural gas.  Prominent gasification processes
(fourteen) of current and potential interest are shown in Table 5-1 along with
their expected products and byproducts.
     Principal sub-divisions of coal gasification processes are differentiated
by low-, intermediate- and high-temperature operations.  The type of reactor
bed (fixed, fluidized or entrained) is also another operating variable.  The
low-temperature and fixed-bed processes tend to show a complete product and
byproduct slate similar to the coke oven process.  As the temperature of
gasification increases* recoverable quantities of heavier tars begin to
diminish in preference to increasing lighter molecular weight products.
Operating pressure also affects the yields, as shown in Table 5-1.  As the
pressure increases, the product slate tends towards the heavier molecular
weight substances.
     A coal gasification plant consists of many unit operations/processes.  A
block flow diagram of a hypothetical synthetic natural gas plant is shown in
Figure 5-1.  The plant is comprised of the following major areas:
     1.   Coal Storage, Preparation and Feeding;
     2.   Gasification and Gas Cleaning;
     3.   Product Upgrading (Methanation);
     4    Byproduct Recovery and Upgrading; and
     5.   Waste Treatment.
     The basic steps to produce a synthetic natural gas (SNG) fuel are as
follows:  First, coal is prepared to the desired size by crushing, removing
fines and drying the coal (if necessary).  The coal is then either fed to the
gasifier or, if it is a caking coal and the process cannot operate with such a
coal, it is pretreated with heat to prevent the formation of coke.
     The coal is then reacted with oxygen and steam in the gasifier.   (Note:
If the final product gas is to be a low-Btu gas, then air can be used instead
of oxygen.)  Pertinent chemical reactions and the devolatilization step mechanism
which generates the raw gases within the gasifier have been previously discussed.

                                    -62-

-------
OJ
• TABLE 5-1
COAL GASIFICATION PROCESSES PRODUCT/BY-PRODUCT AND FUEL SYSTEM SIMILARITIES
LEGEND:
P - Product/Bv-Product
present in recoverable
quantities.
Neg. - Negligible or small
amounts present.
- Stream present in traces.
N.A. - Information not
available, not com-
plete, or not reported
at this time.
1*roduct!/By-Products
High BTU Gas - SNG
Low (Intermediate)
BTU Gas
H2S - Acid Gas/Sulfur
Ammonia
Phenols
Naphthas/Benzenes
Tar Oils/Light Oils
Tars
Char/Unreacted Coal
Ash/Slag
CLASSIFICATION OF FUEL SYSTEMS
Low Temperature
Fixed Bed
Low
Pressure
Wellman - Galusha
P
P
P
P
P
N.A.
P
-
P
-
Intermediate
Pressure
'§»
3
_)
P
P
P
P
P
P
P
P
-
P
BGC/Lurgi
Slagging Gasifier
P
P
P
P
P
P
P
P
-
P
Pressurized Stirred Fixed
Bed - Morgantown
-
P
P
P
P
-
P
P
P
P
Intermediate Temperature
Fluidized Bed
Low
Pressure
k*
a>
jf
c.
P
P
P
NA
Neg.
-
-
-
P
-
Inter-
mediate
Pressure
8
en
1
=3
-
P
P
P
Neg.
N.A.
Neg.
Neg.
P :
-
High Pressure
Synthane
P
-
P
P
P
P
P
P
P
-
|
P
_
P
P
P
P
P
-
P
-
High Temperature
Entrained Bed
Low
Pressure
.*
Q)
2
O
e
8.
n.
o
X
P
P
P
Neg.
-
-
-
-
-
P
High
Pressure
S
. CD
.J.
00
P
-
P
P
-
-
-
-
-
P
Dolomite
Acceptor
Intermediate
Temperature
Intermediate
Pressure
S
I
0
<
CN
0
o
P
-
P
P
N.A.
N.A.
N.A.
N.A.
P
-
Westinghouse-Advanced
Gasifier
_
P
P
N.A,
-
-
-
-
-
P
Coal
Pyrolysis
Entratnet
Inter.
Temp.
Low
Pressure
**
' S
• E
•S o
II
P
P
P
P
-
-
-
-
-
P
Fluid Bed
Inter.
Temp.
Inter.
Pressure
Garretts Coal
Gasification
P
P
P
N.A.
-
-
-
P
P
-

-------
CM!
                 Figure 5-1.  Hypothetical coal gasification flow diagram.

-------
     The raw gases are next processed through the gas cleaning and purification
steps to remove tar, particulate matters and sulfur compounds.
     The raw gases produced in the gasifier do not have the proper proportion
of CO and H  necessary to form SNG or synthesis gas.  A shift catalyst reactor
unit is introduced to produce appropriate gas mixtures.  In the shift reactor,
any desired ratio of carbon monoxide and hydrogen can be achieved by varying
the amounts of steam and carbon dioxide as demonstrated by the following
reaction:
          CO + H_0   ""    ».  H0 + C0_, A H°   =9.9 Kcal/mol
                2              2     2     25°C
(Note:   If hydrogen is the desired final product, the carbon monoxide is all
converted to carbon dioxide and hydrogen; carbon dioxide is then scrubbed from
the gas by any of several available processes.)
     If a high Btu gas (SNG) is the objective, then the required ratio of
hydrogen to carbon monoxide is 1:3.  The following chemical reaction (called
methanation) is employed:
          CO + 3H,   *    »  CH, + H.O,  A H°    = 49.3 Kcal/mol
                 Z              *    -*       25°C
     The methanation reaction is highly exothermic; consequently, heat removal
methods are the dominating feature of the different developing processes.
     The Byproduct recovery and waste treatment aspects of the coal gasification
processes will vary for each specific process, since the recoverable quantities
of byproducts and the waste characteristics are dependent on gasifier operating
conditions.   The feed coal characteristics also significantly affect the
quantities of products and byproducts generated from a process.  Adequate
literature information is unavailable to establish the effects of coal types
on the distribution of products and byproducts for different gasification
processes.  Table 5-2 shows the quantities of products and byproducts generated
by a few selected processes.
     Figure 5-2 illustrates the Byproduct recovery scheme and the distribution
of the various byproducts from a Lurgi plant that will produce 288 SCFD of
synthetic pipeline quality gas.  A sizable portion of the byproducts are
absorbed in, or condensed with, the organic and aqueous condensates as the
gases are quenched with water and then cooled.  The heavier tars separate out
first in the gasifier waste heat boiler and are called "tarry gas liquor."
Further downstream, in the gas cooling section, the tar oils with the remaining

                                     -65-

-------
     COAL
    •TEAM
   OXTWN
•Y M00UCT
 TREATMENT
BYPRODUCT
 STOAAOE
                                                                                          TO UCTHAMATKM
                       VENT
             TAR
                   TAR (ML
                                             CONTAMINATED    S\     CltUi
                                               WATEH            WATER      |f _,Q
                                         VENT
CRUDE
PHENOL
                                                               VENT
                                                               1
AQUEOUS
AMMONIA
                                                                                   VENT
LIQUID
tULFUR
                                                                                                      VENT
                                                           NAPHTHA
                        Figure 5-2.   Byproduct  from Lurgi Plant,

-------
                    TABLE 5-2.  PRODUCTS/BYPRODUCTS OF DIFFERENT COAL GASIFICATION PROCESSES
                                         (SOURCE - Bibliography 35)
Char/Ash, Ib/hr
  (Slag)
Coal, Ib/hr x 106
Feed Coal
Sulfur Content (%)
Wellman
Galusha
28.
170
177
1,153

120
219

1,768
0.
Bitum.
3.
Lurgi
4 288
(SNG)
15,600
88,800
48,600
11,300
21,400
20,000
(naphtha)
476,000
(ash)
021 1.94

9 1.07
Koppers
Totzek
524
290
23,600
Neg.
Neg.
Neg.
Neg.

24,400
(ash, slag)
0.7

3.8
Bumlnes
Stirred Bed
995
160
24,200
75,600


11,100

114,100
(ash)
0.7
W. Ky. #9
3.9
Winkler
912
280
50,400


Neg.
To Glaus

372,500
(char)
1.68
Lignite

Syn thane
250
(SNG)
11,400
43,200

4,000
13,200
7,400
(BTX, naphtha)
362,000
(char)
1.18
Pitts Seam
1.6
Hygas
260
(SNG)
55,500


1,300
11,300
39,800
139,000
(char)
1.06
111. #6
4.75
Note:  "SNG" signifies Synthetic Natural Gas.

-------
tars condense out, forming the "oily gas liquor."  In the acid gas removal
step, H?S and naphtha separate.  Naphtha goes directly to a storage tank.
H_S-containing acid gases are further processed to recover the sulfur.  Table
5-3 gives the material balance for the gas liquor treatment.

Acid Gas Removal and Sulfur Recovery
     The acid gas removal unit removes sulfur compounds, carbon dioxide and
any other material which would interfere with the methanation or synthesis
step that follows.  The unit processes involve chemical or physical absorption
of the acidic materials in a suitable liquid with subsequent desorption of the
acid gases at a lower pressure (in some cases higher temperature) to regenerate
the absorbent.
     Among the many acid gas removal processes, the following are the most
widely considered for coal conversion systems:
          Chemical Processes        Physical Processes
            Hot Carbonate System      Rectisol CMethanol Solvent)
            Amine System              Selexol (Dimethoxy Tetraethylene Glycol)
            Stretford Process
     In the coke oven industry, only the chemical solvent type acid gas removal
processes have been commercially utilized.  The physical solvent type processes
will be more applicable when the raw gas is at a higher pressure (which obviously
cannot be related to the coke oven process since it operates near atmospheric
pressure).  Detailed discussions of the coke oven gas desulfurization processes
and their applicability to coal conversion systems are given in Section 7.0.
Table 5-4 shows the acid gas removal processes that have been considered in a
            (39)
recent study     for various gasification processes.
     The Stretford process not only removes acid gases from the gaa; but, it
also recovers byproduct sulfur.  Therefore, it is also considered a sulfur
recovery process.  Other processes listed above, produce a concentrated acid
gas stream (rich in hydrogen sulfide concentration) which requires further
control through a sulfur recovery and tail gas unit to meet air pollution
control regulations.  The two most common sulfur recovery processes are the
Glaus and Stretford.  The Stretford process is economic when the acid gas
                                     -68-

-------
STREAM NUMBER
                                    11.1
             11.2
  TABLE 5-3.  MATERIAL BALANCE FOR GAS LIQUOR TREATMENT




11.3        11.4      11.5   11.6       11.7       11.8
                                                                                                                     11.9
                                                                                                                             11.10
                                                                                                       11.11
     TOTAL  (Ib/hr)
277,450   1,314,800    62,165
          103,000   48,600  88,800
                                                                                        11.12


Stream Description
Phase
Component (Ib/hr)
Water
Tar
Tar Oil
Recoverable Crude Phenol
Unrecoverable Phenol & Organic
Ammonia
H-S
c82
CO'1
CH,
Monohydric Phenols
Polyhydric Phenols
Other Organics
Contained Sulfur
Naphtha

Tarry Gas
Liquor
Liquid

165, 000
79,900
14,600
210
130
—
300
17,200
70
40
—
—
—
—
—

Oily Gas
Liquor
Liquid

1,180,000
8,900
34,000
11,100
4,100
21,600
300
54,800
—
—
—
—
—
—
—

Expansion
Gas
Gas

2,030
—
—
—
—
—
315
59,700
70
50
—
—
—
—
—

Process
Condenaate
Liquid

103,000
—
—
—
—
—
__
—
—
—
—
—
—
—
—

Tar
Oil
Liquid

—
—
48,600
—
—
—
__
__
—
—
—
—
—
(73)
—
Contaminated
Gas
Tar Liquor
Liquid Liquid

164,000
88,800
—
—
—
—
— _ — —
—
— —
—
3
70
60
(240) —
—

Crude
Phenol
Liquid

—
—
—
—
—
—
__
—
—
—
9,100
1,600
560
—
—

Acid
Gas
Gas

8,870
—
—
—
—
—
280
8,570
—
—
—
—
—
—
—

Clean
Water
Liquid

1,190,000
—
—
—
—
240
__
—
—
—
24
900
3,200
—
—

Aqueous
Ammonia
Liquid

82,000
—
—
—
—
21,400
10
3,660
--
—
—
—
—
—



Naphtha
Liquid

—
—
—
—
—
—
__
—
—
—
—
—
—
—
20.000
164,133    11,260  17,720  1,194,364  107,070   20,000

-------
      TABLE 5-4.  ACID GAS REMOVAL PROCESSES FOR COAL GASIFICATION SYSTEMS

                                 (SOURCE -  BIBLIOGRAPHY 39)
Gasification Process

Lurgi


Synthane


Bigas


Hygas


Koppers-Totzek

U-Gas

Winkler
% H S in acid
   gas feed
(on dry basis)

      1.10
      1.50


     14.6


     29.8


     23.1

     17.9

     15.0
Preferred
 Acid Gas
 Process

 Rectisol
 Hot Carbonate
 (Benfield)

 Hot Carbonate
 (Benfield)

 Rectisol
 Methyl diethanolamine

 Selexol

 Hot Carbonate
 (Benfield)
Type of S
  Guard

Zinc or
Iron Oxide

Zinc or
Iron Oxide

Zinc or
Iron Oxide

Zinc or
Iron Oxide

Not needed

Not needed

Not needed
                                     -70-

-------
contains  less  than 15 percent H S,  whereas the Glaus process is more economical
above a 15  percent H S inlet concentration.  Both Glaus and Stretford have
been utilized  in coke oven plants and should have applications in coal con-
version systems.
     The  sulfur content of the gas leaving the acid gas absorption system is
decreased further, usually by reaction with iron oxide or zinc oxide.  This
step is necessary to protect the methanation or synthesis catalyst, which is
highly sensitive to sulfur compounds.  In the coke oven plants, the iron oxide
process is  frequently used to remove sulfur compounds.

Waste Characteristics and Comparisons
     At present,  the nature of the waste characteristics from coal gasification
and liquefaction plants have been described mostly in qualitative terms.  Much
of the published quantitative information is based on pilot systems which may
not be indicative of future commercial systems.  The characteristics of waste
streams that are predicted for commercial systems, therefore, are based on
engineering analysis of the coal conversion processes and related operations,
such as coke ovens and coal preparation plants.
Wastewaters—
     The  following major wastewaters are associated with coal gasification
systems:
     1.  Quench and condensate waters from gasification;
     2.  Wastewater from the shift and methanation (or synthesis) units;
     3.  Coal pile runoff; and
     4.  Miscellaneous waters, e.g., storm water runoff, boiler blowdown, etc.
     Detailed  characteristics of these wastewaters for the different types of
coal gasification processes are not available.  However, many studies are in
progress  under DOE and EPA sponsorship to develop additional information.
Coal pile and  storm water runoffs will contain relatively less pollutants than
the process wastewaters.
     The  compositions of the quench and condensate waste streams from the
gasification process are expected to be dependent on the coal conversion
process,  the operating conditions,  and the coal type.  The limited experimental
                                     -71-

-------
data available indicate that those gasification processes which produce
byproducts similar to coke ovens (e.g. tars, tar oils, naphtha) will generate
wastewaters similar to the Byproduct coke oven process.  This was illustrated
by the wastewater composition shown in Table 1-3 (abstracted from Tables 4-2,
5-3 and 5-5).
     High temperature and low pressure gasification processes that do not
generate much byproduct (e.g. K-T process), on the other hand, will generate
low concentrations of contaminants in the process wastewater and are not
comparable to the Byproduct coke oven process.
     Coal type and composition have significant effects on the process waste-
water.  This is illustrated in Table 5-5, where the effect of various coals on
Synthane wastewaters are shown.  These data were obtained from a laboratory
scale operation of the Synthane process.
     Approximately 60 to 80 percent of the toal organic carbon in the coke
oven and coal conversion wastewater appears to be phenolic in nature consisting
of monohydric, dihydric and polyphenols.  Singer, et al. have recently reported
the breakdown of the phenolics and other organics in the coal conversion
          (58)
wastewater
Gaseous Waste Streams—
     The following major gaseous streams are associated with coal gasification
processes:
     1.   Raw product gas from the gasifier;
     2.   Acid gases from the acid gas removal unit;
     3.   Cooling tower emissions;
     4.   Flue gases from the utility boilers; and
     5.   Fugitive emissions, e.g. from coal pile, compressors, storage
          tanks, etc.
     The characteristics of the raw product gas and the acid gases have been
discussed previously.  Characteristics of the flue gases from the utility
boilers will be dependent on the type of fuel used in  the boilers, e.g., raw
coal, processed clean product gas, or raw product gas.
     No data is available on the fugitive emissions.   Fugitive emissions
sources are:  cooling towers; compressors; valves; flanges; coal pile; waste-
water and solid handling units; etc.  The fugitive emissions are expected to

                                     -72-

-------
      TABLE 5-5.   PROCESS WASTEWATER ANALYSIS FROM SYNTHANE GASIFICATION OF VARIOUS COALS
                             (All values in mg/1, except pH;  Bibliography 26)
Illinois
No. 6
Coal
8.6
600
2,600
15,000
152
0.6
8,100
500
6,000
11,000
1,400
Wyoming
Sub-bit.
Coal
8.7
140
6,000
43,000
23
0.23
9,520
_
-
-
-
North
Dakota
Lignite
9.2
64
6,600
38,000
22
0.1
7,200
-
-
-
—
Western
Kentucky
Coal
8.9
55
3,700
19,000
200
0.5
10,000
-
-
-
-
Pittsburgh
Seam
Coal
9.3
23
1,700
19,000
188
0.6
11,000
-
-
-
-
- Data not available

-------
contain hazardous species that are in the raw product gas such as hydrogen
sulfide, carbon monoxide, and hydrogen cyanide.  These pollutants are also
present in the coke oven fugitive emissions.
Solid Wastes-
     The following are major solid waste sources from a coal gasification
plant:
     1.   Ash or slag from the gasifier;
     2.   Particulates from coal preparation;
     3.   Ash from coal burning in the Utility Boiler;
     4.   Wastewater treatment sludges; and
     5.   Spent catalyst from the methanation  (or synthesis) reactor and shift
          converter.
     The ash or slag from the gasifier accounts for the largest quantitative
source of solid wastes, and these wastes contain the most numerous types of
contaminants including many heavy metals.  Solid wastes of similar composition
are not generated in the coke oven industry.
     Characteristics of the particulate matter from coal preparation and the
sludges from wastewater treatment will have some similarity between the two
industries.
                                    -74-

-------
                                    SECTION 6
           COAL LIQUEFACTION PROCESSES AND THEIR WASTE CHARACTERISTICS

COAL LIQUEFACTION PROCESSES
     The objectives of the U.S. coal liquefaction development programs are to
develop viable processes that will produce low-sulfur and low-ash products
from coal to be used as boiler fuels, heating oils, gasoline and chemical
feedstocks.  Although none of the processes currently under development has
achieved commercial status, several have reached the pilot plant stage.  Table
6-1 shows the processes of current and potential interest along with their
expected products and byproducts.
     Since coal has only about 5 percent hydrogen compared to 9 to 11 percent
for fuel oils and 14 percent for gasoline, converting solid coal to liquid
fuels requires increasing the hydrogen content relative to carbon (H/C) in the
coal.  Coal liquefaction processes increase the H/C ratio either by adding
hydrogen to the coal or by removing part of the carbon as is done in the coal
pyrolysis processes.  Pyrolysis processes that developed from coke oven
technology, however, yield small quantities of liquid products, since large
amounts of gaseous and solid char products are also produced.  Table 6-1 shows
the four types of coal liquefaction processes:  catalytic hydrogenation,
solvent extraction, hydrocarbonization, and pyrolysis.
     In the catalytic hydrogenation and solvent extraction processes, the coal
is dissolved in process-derived solvent, and molecular hydrogen is added via a
hydrogen donor solvent.  Three of the processes under these categories (SRC-I,
fl-Coal and Exxon Donor Solvent processes) have, thus far, received the most
concerted development effort.  They will be discussed subsequently in detail.
     Pyrolysis processes are similar to coal coking in that the coal is heated
to remove tars, gas and other volatiles leaving a coal char that is largely
carbon.  Coal pyrolysis processes usually operate at low pressures (20 to 50
psia) and moderately high temperature  (approximately 1,600 F).

                                     -75-

-------
TABLE 6-1
COAL LIQUEFACTION PROCESSES-PRODUCT/BY-PRODUCT AND FUEL SYSTEM SIMILARITIES
LEGEND:
PPrnduct/ftv-Prnrtiirt nratnnt
in recoverable quantities.
Meg.- Negligible or (null amounts
present.
- Stream present in traces.
N.A. - Information not available,
not complete, or not reported
at this time.
Products/By -Products
High B.T.U. Gat - SNG, LPG, ethylene,
hydrocarbon, product gas.
Low Intermediate) BTU Gas -
Fuel Gas. Synthesis Gas
H2S Acid Gas/Sulfur
Ammonia
Phenols
Benzenes
Naphtha, Gasoline
Syncrudes
Middle Distillates, Fuel Oil
Gas Oils, Neutral Oils, Chemical Oils
Residual Fuel Oils
Tars (Tar Acids and Tar Bases)
Solvent Refined Coal
Cher/Coke/Unreacted Coal
Ash/Slag
CLASSIFICATION OF FUEL SYSTEMS


Catalytic Hydrogenation
3
P
-
P
P
Nag.
N.A.
P
P
P
P
P
-
-
P
P
S
£
j?
P
-
P
P
N.A.
N.A.
-
P
-
-
P
-
-
P
-
e
_o
sfii
N.A.
N.A.
P
P
P
P
P
P
P
P
P
-
-
N.A.
N.A.
Sefveffl Extraction
Non-Catalytic
Solvent
Hydrogenation
u
^ K
5 tr t>
P
—
P
P
P
-
P
-
P
-
P
-
P
P
P
Catalytic
Solvent
Hydrogenation
Ml
LU a c/S £
P
—
P
N.A.
N.A.
N.A.
P
-
P
P
-
-
-
-
P
HydroearbanbatiM
Intermediate
Temperature
g
•a -a -p
3*1
p
—
p
p
p
p
p
-
p
p
-
p
-
p
-
High
Temperature
<3 CM
S*l §
££Z£
p
—
p
p
p
p
p
-
-
p
-
p
-
p
p
fc.--— at. 	 »^-
Low
Temperature
Fluid Bed
Skis
lilS
SiSaS
-
P
P
N.A.
P
P
-
P
-
-
-
-
-
P
-
Intermediate
Temperature
Entrained
Bed
SI
p
p
p
N.A.
-
-
-
P
P
-
-
P
-
P
' -

-------
     Hydrocarbonization is a refinement of the coal pyrolysis process.  It
consists of carbonization of coal and thermal cracking of the heavy coal
liquids (tars) in a hydrogen atmosphere to produce fuel oil, distillate and
fuel gas.   Hydrocarbonization operates at both a moderate pressure (500 psi)
and temperature (1000 F).  The pyrolysis and hydrocarbonization processes are
the direct development of the Byproduct coke oven process.  Their product/
byproduct slates are very similar.  The waste characteristics are expected to
be similar also.  However, insufficient data exist to verify this hypothesis.
     Figure 6-1 shows the block flow diagram of a hypothetical coal liquefaction
process (hydrogenation or extraction type).  The principal features of the
process are:
     1.   Hydrogenation reaction unit;
     2.   Separation unit (where gaseous products are separated from the
          liquid and solid products);
     3.   Filtration (or solid separation) unit;
     4.   Acid gas treatment and sulfur recovery unit; and
     5.   Product fractionation and upgrading units.
The feed coal is crushed, dried, and slurried with a coal-derived solvent
(produced by the process) and fed to the liquefaction reactor in admixture
with gaseous hydrogen.  Gas, liquid.and solid phases are produced in the
reactor by a series of complex chemical reactions which include decomposition
(depolymerization), hydrogenation, and rearrangement of the organic coal
structure.
     The reactor effluent containing liquid products, solids and gases are
next separated for product and byproduct recovery.  The separation schemes
vary for each process.
     Separation of ash and unreacted coal from viscous coal liquids is a
difficult problem common to all liquefaction processes and has been the focus
of considerable development effort.  Many techniques are being investigated,
including filtration, centrifugation, fractionation, and solvent separation.
     In coal liquefaction processes, distinct patterns of product slates
(Table 6-1) do not readily emerge as in the coal-gasification processes.
                                     -77-

-------
CM) Store.*,
Fttdinf ind Sytttnt Wtrtti
Convtrttr Output
                                                                                       Product! Md By Product!

D*o.,

Stud*

Co*l
Storift
1
Cotl
fVtpmtion
1
Slurry
Prtpartlion

9ud«t

Wrttr








(
4 	 (
I
I
	 !

__.


	 »j
Itlon



T
1
Alh ind Char
t
GM Production
t
	 ' ,
Filttr Ciki
t

Fittritian


i
ConlHninited
Wirrr
4

	 	 	 Witir
Tri«tm«nl









Utilifition
1
_.___- Solution __^
RtoiiKirtkin
r&v
T i
Stptntlon •-*!
T«Hfti
Trtilmint
i
i
PwrWicitlon — t
Furl Cw
Jt t
( 	 N»pht1>»
^~ "^ |" ~* Hydrotr««i-«nt "*
(tiphlhi
i -r x
_.,,,, 	 ft f«"' «« . _»
-» FrKtiorwtlqn 	 * Hydrotmnwm 	 *
i J
j T T
	 jLi


Fuil Oil

Htm/ Product

s;rd

                   Figure  6-1.   Hypothetical coal liquefaction  flow  diagram.

-------
However,  the following observations can be made:
          All liquefaction processes produce an acid gas stream which will
          contain sulfur and other contaminants.  In this regard, they are
          similar to coal gasification processes which also produce an acid
          gas stream.  Consequently, H S removal and sulfur recovery will be
          required for all coal processing plants.
          Liquid product distribution shows a range from syncrudes to naphtha
          and gas oils.  However, all will contain varying amounts of sulfur,
          nitrogen, and metal contaminants which will have to be removed by
          subsequent upgrading treatments.  Only the solvent refined coal
          (SRC-I) process yields a solid fuel.  In all other processes,
          additional hydrogenation results in the formation of liquid products.
          Almost all the processes produce a char (coke and unreacted coal
          combined with ash) byproduct with some fuel value.  These byproducts
          will require additional processing (e.g., specially designed
          combustion units) to utilize the carbon value.  This will increase
          the energy efficiency of the conversion process.
          Phenols and/or ammonia will be present in the aqueous waste streams
          in most cases and could be recovered as byproducts.
     It is difficult to give quantitative yield data and waste characteristics
of coal liquefaction process since these are dependent on many variables such
as:
     1.   Coal type and composition;
     2.   Hydrogen consumption;
     3.   Liquefaction process and its operating conditions;
     4.   Hydrogen generation method;
     5.   Product specifications; and
     6.   Power generation method.
     Unlike the coke oven process which uses a specific type of coal mix,
various coals can be used to produce liquid products.  Yields will vary
depending on the coal composition.  For example, the liquid yield is about 2.6
barrels per ton (B/T) of dry Illinois #6 coal, and about 2.3 B/T from Wyoming
                                        (25)
coal for the Exxon Donor Solvent Process
                                      -79-

-------
     Hydrogen consumption in the process has a direct bearing on the quantity
and quality of the liquefied products.  As an example, the hydrogen consumption
for the SRC-I process is about 2 weight percent of moisture-free coal; whereas,
it is approximately 4 weight percent for the H-Coal and the EDS process.  Less
hydrogen consumption in the SRC-I process is the reason for its production of
mostly solid refined coal and a lesser amount of liquid products.  If additional
hydrogen is consumed in the SRC system (by additional hydrogenation in the
reactor), more liquid products will be generated, as in the SRC-II process.
     The liquefaction process and its operating conditions have a significant
effect on product type as illustrated in Table 6-2 for the three major processes.
Other variables such as reactor detention time, catalyst utilization, solvent
type and reactor type have an impact on product/byproduct yield.  The lique-
faction reactor design for the SRC-I and Exxon Donor Solvent  (EDS) process is
an upward plug flow type; whereas, the H-Coal uses an ebullated bed where a
catalyst is also added.  The EDS process uses a solvent oil which has been
catalytically hydrogenated in a fixed bed reactor.
     The method of hydrogen generation affects the product/byproduct slate and
the environmental aspects of the plant.  Since the cost of hydrogen is a key
economic factor in coal liquefaction processes, various schemes are under
consideration to generate hydrogen from the byproducts of the coal liquefaction
(e.g., gasification of char and solid wastes, steam reforming of fuel gas).
The hydrogen generation plant is a large unit in the overall coal liquefaction
complex and its contribution to the plant waste streams would be significant.
     The power generation plant is another large contributor to the general
waste streams.  Methods of power generation will vary from plant to plant.  In
order to decrease the complexity and number of variables, the power generation
unit and other auxiliary units such as the oxygen plant, the water treatment
unit etc. have not been considered in this report.
     As the foregoing discussion shows, the potential variables are so numerous
that the material balance and quantitative yield data for a specific liquefaction
process can be presented meaningfully only when all the different variables
are considered in detail.  (Also, comparison of one process with another will
not be meaningful if these variables are not fixed.)  This has been done for
an example coal liquefaction plant for the SRC-I process.

                                      -80-

-------
              TABLE 6-2.  OPERATING CONDITIONS OF THREE LEADING
                          COAL LIQUEFACTION PROCESSES
Process
H-Coal
  Reactor
 Pressure
  (psia)

2,700-3.000
Reactor         Hydrogen
 Temp.         Consumption
 ( °F)      (scf/bbl product)

    850        4,000-7,000
  Product
   Type

Syncrude or
fuel oil,
fuel gas
Exxon
Donor
Solvent
Process
1,500-2,500    700-900
               5,000-6,000
Fuel oil,
naphtha,
fuel gas
SRC-1
1,000-2,400    625-850
                 1.5-3.0
                 wt% of
                 MF Coal
Solid boiler
fuel, naphtha,
fuel gas
                                    -81-

-------
SRC-I PROCESS MATERIAL BALANCES
Design Basis
     Based on the published information on the process conditions and operating
results  from the Wilsonville and Fort Lewis SRC pilot plants, a conceptual
design for a 20,000 TPD coal feed SRC-I plant was prepared and is discussed
here.  The data obtained at Wilsonville in Runs 70 through 81 and at Fort
Lewis in Runs 4 through 9, using Kentucky #9 and #14 coals and solvent of
boiling  range 450 to 780 F, were used to develop the design basis.  Table 6-3
summarizes the design basis.

Overall Material Balance
     An overall flow diagram and material balance for the SRC-I process are
shown in Figure 6-2 and Table 6-4 respectively.  The basic SRC-I process
consists of seven modules:
          Coal receiving and preparation;
          Slurry preparation, preheating and dissolving;
          Hydrogen recovery;
          Precoating and filtration;
          Solvent recovery;
          Product recovery and solidification; and
          Hydrogen manufacture
     Coal is dried, crushed, mixed with coal-derived solvent and hydrogen,
preheated, and introduced into a dissolver (liquefaction) reactor where coal
is reduced to liquid products.  The resultant process stream is flashed to
remove hydrocarbon gases.  Unreacted coal and ash solids are next removed from
the liquid slurry by precoat filtration.  The filter cake is sent to the
hydrogen generation module where the Koppers-Totzek gasification process will
be used to generate hydrogen.  The filtrate, containing SRC liquid and the
solvent,  is next sent to the product recovery module where fractionation and
solidification are used to obtain the SRC solid product.
                                      -82-

-------
        TABLE 6-3.   DESIGN BASIS FOR A 20,000 TPD COAL FEED SRC-I PLANT
1.   Coal Type:
          Unground Coal Moisture:

2.   Ground Coal Analysis

     A.   Proximate Analysis (Dry Basis)
               Volatile Matter
               Fixed Carbon
               Ash
          High Heating Value (MF)
          Moisture (wt %)

     B.   Ultimate Analysis (Dry Basis)
               Carbon
               Hydrogen
               Nitrogen
               Chlorine
               Sulfur
               Ash
               Oxygen

     C.   Sulfur Forms
               Pyritic
               Sulfate
               Organic

3.   Operating Conditions
          Coal Cone.  % MF
          Space rate Ibs/hr-ft , MF
          Dissolver Outlet Pressure, psig
          Hydrogen Purity, Mol %
          Hydrogen Partial Pressure, psig
               Preheater Inlet
               Dissolver Outlet

4.   Yields
          Conversion, % MAF coal
          Hydrogen Consumption, % MF Coal
          Yields, % MF Coal:
               CO
               co
                              Kentucky 9-14 Colonial Mine
                                      9.2 wt %
                                      Wt.%
                                      39.8
                                      49.8
                                      10.4
IBP-350 F
350°F - 450°F
               450°F -
        EP
               SRC
               Unconverted Carbon
               Ash
               HO
          Sulfur in SRC, %
                                            12,929 Btu/lb
                                       2.0
                                      70.4
                                       5.1
                                       1.4
                                       0.1
                                       3.4
                                      10.4
                                       9.2
                                       1.5
                                       0.2
                                       1.7

                                      '38.4
                                      75.0
                                    1650.0
                                      87.0

                                    1450,0
                                     870.0


                                      91,2
                                       1.95

                                     (-0.14)
                                       0.64
                                       1.81
                                       1.40
                                       0.76
                                       0.76
                                       0.16
                                       0.17
                                                      2.
                                                      7.
  .92
  .58
 2.11
61.66
 7.86
10.15
 4.11
 0.96
                                      -83-

-------
TABALE 6-3 (Cont'd)
5.
6.

7.
8.








9.



Organic Sulfur Removal: 57.5 wt%
N and 0 Removal: In Feed Coal
22 Wt %
N2 1.36
02 9.32
Recycle Solvent Boiling Range: 450 -

In SRC
Wt %
1.72
4.44
780°F
Filter Cake Composition (Feed to H2 Plant)

C
H
N
Cl
S
0
Ash
Physical Properties:
A. Sp. Gr. of Various Coal Slurries
Cone. % 25 25
Temp., °F 60 150
Sp. Gr. 1.083 1
B. Sp. Gr. of Process Solvent (450-780°
Wt %
46.38
3.36
0.90
0.02
6.17
4.40
38.77


.065
F)
Temp., °F 60 150
Sp. Gr. 1.025 0.980







C. Viscosity of Coal Slurries
Cone. % 25 25 25
Temp. °F 85 125 165
Vise. , CP 55 35 21
D. Properties of Liquid Products
Product Liquid, BP°F
Light Oil IBP-350
Wash Solvent 350-450
Process Solvent 450-780
SRC




API°
15.9
10.0
4.6
-22.6
                             Removal

                                22

                                71
                            38
                            60
                             1.133
                           200
                             0,972
                            38.5
                            85
                           177
                             BP°F
                              320
                              400
                              567
                             1300
      38
     150
       1.106
     250
       0.955
 38.5
125
 70
   MW

   115
   130
   170
   750
 38.5
165
 62
  BTU/lb

  19,000
  18,000
  17,000
  15,800
          -84-

-------
COAL
AIR
SEPARATION
FS-7

STEAM (46) * (MI to

M7) (51) B (56)
\ > 1
SEE NOTE 3 (TYPICAL)
__ _^ re „ o

vnonrcM •^^vrNT GASPS . C99> RECOVERED H2 FROM
LANT U-T) ^VENTGASES WASTE GASES
re *

t
TO .STACK
A (2)
1(4)
8AGHOUSE
(64) (65)
\ i

( , } COAL RECEIVING B ,,,
L j (48, 1
SLAG
T
(6)1
f '
16, «•• FS/9
, r ,r '' * >
U (IS) (17)
r-s i <281 fc "? RECOVERY
FS-3
i t
(71 Mi) 
-------
SEE NOTE 3 (TYPICAL)

            (36)
                                     Fs-9
                                      F5-8
                                            .(29) ft (35)
FROM FIGURE 6-2
   PAGE  I
(13)
                   (19)
FROM FIGURE 6-2
    PAGE I
                                     (22)
                        FS-8 FS-9


                       (24)
          «-B
          4 «
      PRECOAT AND
       FILTRATION
          FS-4
          PRECOAT
                  (26)
                             T
          SOLVENT RECOVERY
               FS-5
                                  |(20)

                                FUEL
                                                                           LIGHT  OIL
                                                                            STORAGE
                                                                             FS-5
                                                                                         (28)
                                                                          (37)
                                                                                              •••FS-3
                                                                               -•»• TO PLANT FUEL
                                                                          WASH SOLVENT
                                                                            STORAGE
                                                                             FS-9
                                                                                        (25) a (27)
                                                                           (39)
                                                                           (40)
                          -»»FS-4

                          -^ SALES
                          -»»TO PLANT FUEL
                                                                         PROCESS SOLVENT
                                                                            STORAGE
                                                                             FS-5
                                                                                         (6)
                                                                          (34)
                                                                                 • SALES
                                                            FS-8    FS-9
                                     (42)
       (41)
       (44)
PRODUCT RECOVERY
       a
 SOLIDIFICATION
     FS-6	
                                                            (30) 6(31)
                          FS-S   FS-7
(43)
SRC PRODUCT
 TO SALES
                                                                                                   NOTE: FOR  NOTE 1-3 SEE PAGE I
                                                                                                        OF THIS FIGURE.
               Figure  6-2 (Pg.  2 of  2).  Overall  flow diagram:   20,000 TPD coal feed  SRC-1  process.

-------
I
CO
VI
     Stream No.
     Hydrogen
     CO
     °
     N,
      Light Oil
      Wash Solvent
      Process Solvent
      SRC
      Coal
      Ash/Slag
      Precoat
      HO/Steam
      Ammonia
                             TABLE 6-4.  OVERALL MATERIAL BALANCEj  20,000 TPD SRC-I PLANT
                                          (All flow rates are in tons per hour)
1 2 3 4 5&126
45.
2.
7.
4.
7.
30.
3.
1.
0.
0.
0.

1306.67

776.83 45.99 730.83 0,012
92.52 5.48 87.04 0,001
7
812
99
93
29
08
63
42
23
05
01
62





10
2
0
1
1
3
2
0
0
0
0
8
25
795
504
64
83
.03
.37
.60
.61
.31
.92
.82
.59
.19
.24
.36
.06
.93
.26
.27
.00
11
27.
1.
10.
12.
3.
37.
7.
5.
0.
0.
0.





61
46
61
28
77
41
75
53
46
21
02





13
0.
0.
0.
5.

1.
1.
1.
0.
0.
16.
36.
528.




27
03
96
17

75
07
33
71
96
14
96
00



 88.08
1.05  16.67
70.36
44.61
                                                             5.48    0.17
      Total
957.43     52.52 834.54    70.37     44.61 1306.67 104.06  1500.04 107.28 593.35

-------
                                             TABLE 6-4 (ContM)
Stream No.
Hydrogen
CO
co2

°2
N2
C,
1
C2
C_
3
C4
• CC
i 5
» Light Oil
Wash Solvent
Process Solvent
SRC
Coal
Ash/Slag
Precoat
H20/ Steam
14
26.44
1.34
7.47
4.29

3.54
26.62

3.38
1.23

0.05
0.01

0.62







15 16 17
1,17 16.09
0.12 1.64
3.14 0.46
7.99

0,23 3.39
10.79

4.37
4.30

0,41
0.20

2.20






0.17
19
1,98
0.35
1.53
1.52

3.26
2,83

0.76
0,54

0,16
0.20

3.76
7.70
82.50




4.52
20
0,05
0.02
0.07
0.09

0,05
0,09

0.06
0.05

0,03
0.04

5.31
36.18
673.33
475.01



0.96
21 22














0.05 0.74
10.87 120.33
4.82 36.65
29.25
64.27
83.00
5.5

                                                                                                23
                                                                               24
                                                                                                        0.0
                                                                                                        0.0
                                                                                                        0.03
                                                                                                1.68
Ammonia
Total
74.99    34.92    21.58  0.17     111.61  1191.34   197.76   157.72
                                                                                                1.68
0.03

-------
                                             TABLE 6-4 (Cont'd)

Stream No.              25         26      27      28       29 & 35      30 & 31       34        36       37
Hydrogen
CO
co2

°2
N2
Cl
C2
C3

C5
Light Oil              1,46                0,05   2.8         1.58         5.19                          19.45
Wash Solvent         144.65                5.40
Process Solvent        1.3                 0.05               0.06       668.28       6.9
SRC
Coal
Ash/Slag
Precoat                           5.5
H20/Steatn                                                     1.52         0.94                 3.94
Ammonia


Total                147.41       5.5      5,5    2,8        29.26       710.40       6.9       3.94     19.45
2.30
0.40
2.56
6.78
3.31
4.67
1,89
1.92
0.90
1.20
1.58
0,17
0.06
0,05
0.02
0.07
0.09
0.05
0.09
0.06
0.05
0.03
0.04
5.19
35.44
668.28

-------
                                                  TABLE 6-4 (Cont'd)
     Stream No.
     Hydrogen
     CO
     co
     H2S
     °
  39
41 & 44
 42
43
46
47
48
                                                                        49
                                                   110.34
51 & 56

  0.008
 21.93
 12.94
I
?
     Light Oil
     Wash Solvent
     Process Solvent
     SRC
     Coal
     Ash/Slag
     Precoat
     H,,0/Steam
     Ammonia
     H0S
 0.49
49.9
 0.44
              27.6
            0.12
            0.69    0.05
            0.05    5.00
                  475.01
            0,36
                                              0.01
                                              0.31
                                              0.01
                                                           122.39
                 46.00
                                                 1.35
                                                 0.01
                                                 0.02
     Total
50.83
 27.6
1.22  480.06
        46.00    110.34  122,39
                            0.33
                             36.26

-------
                                           TABLE 6-4 (Cont'd)
Stream No.
Hydrogen
CO
co
 53
   55
  0,11
  0.01
286.4
 59
3.29
0.01
°
                                              0.15
                                              4.01
                                              0.04
Light Oil
Wash Solvent
Process Solvent
SRC
Coal
Ash/Slag
Precoat
H20/Steam
Ammonia
H2S
3.78
0.08
0.06
Total
3.92
286.52
7.50

-------
     Auxiliary facilities required for the plant are the following:
          Air separation plant
            (to supply oxygen to the K-T gasification process);
          Power and steam generation;
          Cooling towers; and
          Water treatment
     Control/disposal modules will be required for gaseous, liquid and solid
wastes.

Waste Characteristics and Comparisons
Gaseous Wastes—
     The various gaseous waste stream sources are the following:
          Module                                    Stream Noa. in Figure 6-2
          Solvent recovery                                  29 and 35
          Hydrogen recovery                                     15
          Precoating and filtration                             24
          Product recovery and solidification                   42
          Hydrogen manufacturing                            51 and 56
     Table 6-5 gives the flow rates and compositions of the above waste streams.
Streams 15, 29, 35, 51 and 56 have sufficient sulfur for recovery.  Sulfur
recovery modules are not included in this section.
     The off-gases from the SRC plant, Streams 15, 29, and 35 contain large
amounts of hydrocarbons in addition to the sour gases.  Thus, a chemical type
acid gas removal process (e.g., carbonate type) which is very common in the
coke oven industry, could be used to concentrate the sour gases; and followed
by a Claus process, together would recover sulfur from the concentrated sour
gas stream.
     Streams 24 and 42 containing small amounts of hydrocarbons should be
incinerated.
                                     -92-

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          TABLE 6-5.  SUMMARY OF GASEOUS WASTE STREAMS, TONS/HR
                            (BEFORE TREATMENT)
Stream No.
Hydrogen
CO
co2
V
Light Oil
Wash Solvent
Process Solvent
SRC
Coal
Ash/Slag
Precoat
H-O/Steam
Ammonia
HCN
  15    .24    29_    _35    42_
 1.17        0.27  2,03
 0.12        0.03  0.37
 3.14        0.94  1.62
 7.99        4.46  2.32
 0.23              3.31
10.79        1.73  2.94
 4.37        1.00  0.89
 4.30        1.13    .79
 0,41        0.41  0.49
 0.20        0.33  0.87
 2.20        0.12  1.46  0.12
       0.03  0.07  0.10  0.69
             0.06        0.05
  _5.L

 0.006
16.09
11.62
                   1.52   0.36   1-35
                                0.01
                                0.02
0.002
5.84
1.32
Total
34.92  0.03  10.07  18.71   1.22  29.10
                                                                7.16
                                      -93-

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Liquid and Solid Wastes—
     Process wastewater originates from both the basic SRC plant and the
hydrogen generation plant.  About 310 gpm of process wastewater from the SRC
plant are discharged from the following modules:
          Module                                     Stream No. in Figure 6-2
          Slurry preparation, preheating and                  5 and 12
             dissolving
          Hydrogen recovery                                      17
          Precoating and filtration                              23
          Solvent recovery                                       36
          Product recovery and solidification                41 and 44
     About 150 gpm of process wastewater will be discharged from the Hydrogen
Manufacturing Plant, contributed mainly by Stream Nos. 88 and 89.
     Table 6—6 summarizes the flow rate and compositions of all liquid waste
streams from the plant.
     About 122 tons per hour of solid wastes will be discharged from the
plant, all originating from the Hydrogen Manufacturing Module (Stream No. 48).
The above solid wastes will contain about 25 percent moisture.
     The SRC plant wastewater, shown in Table 6-6, is quite similar to coke
oven wastewater.  It contains large quantities of phenol, ammonia, sulfide,
and therefore, could be treated in a manner similarly to the coke oven
wastewater treatment scheme.  The wastewater from the hydrogen plant (mostly
from the K-T gasification process), however, is dissimilar to the coke oven
wastewater.  It is a dilute stream and, therefore, no byproduct recovery type
treatment is necessary.
                                     -94-

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                                   TABLE 6-6.  SUMMARY OF LIQUID WASTE STREAMS*
                                                 (BEFORE TREATMENT)







VD
Ul



Stream No.
Ammonia
Sulfide
Phenolics
BOD
Suspended
Solids
Water/Steam
COD
Extractable
Oils
SRC Plant
Process Waste
0.44
0.312
0.351


0.023
78.0
1.170

0.016
H2 Plant
Process Waste
0.008
Trace
0.004
0.008

Trace
37.8
0.076

0.004
Storm
Runoff
0.012

0,006
0.012

0.003
57.5
0.115


Cooling Tower Coal Pile
Slowdown Runoff
0.001

Trace
0.001

0.001
287.5 68.75
0.002


Boiler
Slowdown






102.5


Total
80.312
37.900
57,648
287.5
68.755
102.5
* All flow rates are in tons per hour,

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                                    SECTION 7
              COKE OVEN CONTROL TECHNOLOGY AND ITS APPLICABILITY TO
                            COAL CONVERSION PROCESSES

DESULFURIZATION OF COKE OVEN GAS
     In the coking operation, unacceptable quantities of hydrogen sulfide and
organic sulfur compounds are formed along with the major byproduct constituent,
coke oven gas.  According to most government  regulations, coke oven gas cannot
be burned if  it exceeds 15  to 50 gr/100  SCF  (240  to  480 ppm by vol.) of H S.
These regulations are  summarized in Chapter  9.  Since raw coke oven gas contains
about 5,000 ppmv of H-S, considerable  desulfurization of the  gas  is, therefore,
required.
     Many technologies are  currently employed worldwide for COG desulfurization.
Table 7-1 shows the commercially available control systems and their cited
efficiency ranges.  All of  them are of the chemical  type processes rather than
physical absorption type processes.  These technologies are divided into three
major categories:  1)  Liquid Absorption  Processes (e.g., Vacuum Carbonate,
Sulfiban, Fiona Carl Still, Diamox),   2)  Wet Oxidative Processes  (e.g.,
Stretford, Takahax, Fumaks, Giammarco  Vetrocoke), and 3) Dry  Oxidative Processes
 (Iron Oxide Boxes).
     1.   Liquid Absorption Processes
          Three basic  steps are involved:
          a.   Absorption of  acid  gases  (H S, HCN,  CO-)  into  a recirculating
                solution.
          b.    Stripping of acid gases from solution,  and
           c.    Conversion of H S in acid gases to either elemental sulfur or
                sulfuric acid.
          Absorbing Solutions:
                Vacuum Carbonate - sodium carbonate solution.
                Sulfiban - alkanolamine solution.

                                       -96-

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                    TABLE 7-1,   COKE  OVEN  GAS DESULFURIZAHON PROCESSES
   Category
Commercial Processes
Ranges of % Sulfur Removal
Dry Oxidative
Iron-oxide boxes
      90-99%
Wet Oxidative
Stretford
Takahax
Rhodaks/Fumaks
Giammarco - Vetrocoke
                                                                            98-99%
                                                                            unknown
                                                                            unknown
                                                                            unknown
Liquid Absorption
Vacuum Carbonate
Sulfiban
Firma Carl/Still
Diamox
      90-98%
      90-98%
      90-98%
       97%

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               Firma Carl Still - ammonia solution.
               Diamox - ammonia solution.
     2.   Wet Oxidation Process
          Once hydrogen sulfide is absorbed into solution, it is oxidized
          directly to elemental sulfur which is removed from solution by
          filtration.
          Oxidizing Agents:
               Stretford - anthraquinone disulfonic acid and sodium vanadate.
               Takahax - naphthaquinone sulfonic acid.
               Fumaks - ammonia and picric acid,
               Giammarco Vetrocoke - alkaline arsenite and arsenate.
          In each case, the oxidizing agent is regenerated by air oxidation.
     3.   Dry Oxidative Processing (Iron Oxide or Dry Box)
          Hydrogen sulfide is adsorbed by a solid and either held as a sulfide
          or oxidized to elemental sulfur.  Excessive labor costs and space
          requirements have largely eliminated the use of dry oxidative
          processes  for new plants.  A majority of the old coke oven plants
          use the Iron Oxide process for desulfurization.
     The Iron Oxide/Dry Box process will have limited application in coal
conversion processes.  If applied, it will be used mostly for controlling low
sulfur containing air emissions.  A modified version, under laboratory scale
development through DOE and EPA sponsorships, seems capable of desulfurizing
acid gases at high temperatures.  If this hot gas desulfurization process
becomes competitive with other control processes, it could have broader
applications.
     Based on the desulfurization processes utilized in the coke oven industry,
it appears that the Stretford process should have broad base applications in
coal conversion systems.  The Vacuum Carbonate and the Sulfiban process, two
acid gas removal processes which have been widely employed in the U.S. for
coke oven applications, should find use in the low-pressure gasification
processes, or in the control of low-pressure off-gases from liquefaction
processes.  The physical solvent type acid gas removal processes, such as
Selexol and Rectisol, have not been used for coke oven gas desulfurization
because they require high-pressure feed  (gas) streams.  These processes,
however, should have much wider application in coal conversion systems.
                                    -98-

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     In the coke oven, industry, the Claus process has also been used to recover
sulfur from the rich acid gas stream produced from the Vacuum Carbonate and
the Sulfiban processes.  The Claus process has required several modifications
because of the presence of hydrogen cyanide and other impurities in the acid
gas feed.   Since these impurities are also present in the acid gases from coal
conversion systems, the Claus modifications that have been developed are of
special interest because the Claus process would be a feasible sulfur recovery
technology for the coal conversion systems.  Discussed below are the process
and design data that were available from literature sources for the various
desulfurization processes which may be applicable to coal conversion systems.

Vacuum Carbonate Process
     The Vacuum Carbonate process was first marketed by Koppers in the mid-
1950 's as an improvement over its older Seaborad process.  In the Seaboard
process, regeneration of the absorbing solution was accomplished by air
stripping.  Although this process was simple and economical, it had several
disadvantages.  Contact with oxygen led to numerous side reactions in the
solution, resulting in the need for excessive solution replacement and in salt
disposal problems.  The odors resulting from the foul air disposal also caused
problems.
     To overcome these deficiencies, the Seaboard process was modified so that
the spent carbonate solution was regenerated by vacuum distillation rather
than air stripping.  The use of steam distillation allowed the hydrogen sulfide
to be recovered in a concentrated form from which sulfuric acid or elemental
sulfur could be produced.
Chemical Reactions —
Na2C03 + C02 + H20

	 — »•• isana T wdm^u..
». ovToTirr*
_ .., , ..^ NifTJ + NnlTPO

     The introduction of oxygen, either as the result of its presence in the
coke oven gas or by air leakage into the system, results in several side
reactions that produce non-regenerable salts:
          2NaHS    +  202  - *•  Na2S2°3  +  ^0
          NaS0   +  NaCN  - *•  NaS0    +  NaCNS
                                     -99-

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               03  +  2NaHs  +  H20  - +•  3Na2S203  +  4NaOH
          2NaOH    +
Process Description —
     Gas is contacted counter-currently with a 3 to 3.5 percent solution of
sodium carbonate in an absorber tower to remove the H?S and other impurities
such as HCN and CQ  (See Figure 7-1).  The foul solution from the base of the
absorber is circulated over the actifier, where the H2S is removed by counter-
current stripping from the base of the actifier through a cooler to the
absorber to complete the cycle.  Typical acid gas from an actifier contains 65
to 75 percent H S, 10 to 15 percent C02, 6 to 9 percent HCN.  Where closed
loop final coolers are used to process COG, HCN can exceed 20 percent.
     Traditionally, the Vacuum Carbonate process was  designed as a single
stage unit with an 80 to 90 percent hydrogen  sulfide  removal efficiency  (93
percent maximum).  However, a recent  redesign of the  process to a two-stage
system in both the absorber and the actifier  increases the overall efficiency
of the process to 98 percent.
     In this redesigned process, the  raw coke oven gas is scrubbed of hydrogen
sulfide in a two-stage packed absorber by a counter-current flow of sodium
carbonate solution.  The foul solution is pumped from the absorber to a  two-
stage actifier (regenerator), where steam stripping is used.  To minimize
steam consumption, stripping is carried out at 4.4 inches of mercury absolute
and 54 C.  Separate carbonate solution loops  are maintained in each stage.
However, a one-stage vapor flow is maintained in the  actifier tower.  The
carbonate solution that contacts the  inlet raw coke oven  gas  (and is, thus,
richest in hydrogen sulfide) is sent  to the upper stage of  the actifier, while
the solution from the upper stage of  the absorber is  stripped in the lower, or
secondary stage, of the actifier.  Solutions  are circulated at a rate such  as
to give ma-g-tnnnn cleaning in the second stage  of the absorber.  A 90 percent
hydrogen sulfide removal is claimed  in the first stage, with an additional  8
to 9 percent cleaning in the second.
     The stripped gases and steam pass from the actifier  to  the vapor  condenser
under vacuum,  and the bulk of  the steam is condensed. The  remaining vapors
then pass  through a series of  steam  jet ejectors and  intercondensers and,
                                     -100-

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SWEET COKE-OVEN GAS
  ABSORBER
SOUR COKE-
    GAS
     MAKE-UP
     SOLUTION
                                                                                               SOUR
                                                                                             CONDENSATE
                                                                                             WASTE WATER
                                                       ABSORPTION SOLUTION SLOWDOWN
                            Figure 7-1.  Two stage Vacuum Carbonate system flow  diagram.

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finally, on to the sulfur recovery unit.  Energy economy is achieved by a
system that recovers waste heat and converts it into stripping steam for the
actifier.  Operating costs equal to those of a 93 percent removal plant are
claimed.
     Waste Streams—Figure 7-1 shows that the Vacuum Carbonate process produces
two wastewater streams:  1) spent absorbing solution containing large amounts
of suspended and dissolved solids; and 2) ejector jet condensates containing
significant amounts of HCN and H_S.
     The absorbing solution is degraded by the reaction of oxygen, cyanide and
perhaps ammonia in the presence of H S.  Some of these side reactions were
shown earlier.  Complete replacement of spent absorbing solution is necessary
after 8 to 36 months of operation  (based on a few existing plant experiences).
     The ejector jet condensate quantity is about 55,400 gal/day for a 60 MM
SCFD desulfurization plant (9.72 gal/ton coal charged).  Since this contami-
nated stream will contain H S and HCN,  it will require steam stripping.
Stripped gases can be  recycled back to  the coke oven gas feed to the Vacuum
Carbonate process or incinerated.
Economics and Applications—
     Table 7-2 shows the utility requirements for a 20 MM SCFD and a 60 MM
SCFD Vacuum Carbonate  plant.  Table 7-3 gives the capital equipment costs at
two different efficiencies for the plants shown in Table 7-2.
     Carbonate type desulfurization processes are most applicable to gas
streams containing an  appreciable amount of C02.  If H_S is present, with
little C0_, then carbonate type processes are not suitable for desulfurization.
     For many applications with gas streams contaiuing large amounts of C02,
the advantages of carbonate type processes over amine systems are lower utility
requirements, lower plant investment  (due to elimination of major heat-exchange
equipment) and effective COS and CS^  removal.
     As mentioned earlier, the Vacuum Carbonate process is similar to the
obsolete Seaboard process, but allows for sorbent regeneration unlike the
Seaboard process.
     The Vacuum Carbonate process  sorbent (Na2C03) is not very soluble in
water and therefore, requires large circulating liquor rates.  Newer carbonate
processes use K~CO_ as the sorbent which requires lower liquor flow rates.

                                      -102-

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Note:  Inlet gas concentration is based on 500 grains H S/100 SCF.
                   TABLE 7-2  VACUUM CARBONATE REQUIREMENTS
                                        20 !*MSCFD                60 MMSCFD
Removal Efficiency                   90%        93%           9Q%
Cooling Water, GPH                 1,160       1,320        4,500
Power, KV7-hr/day                   1,835       1,835        5,440
Na2C03(100%), Ib/day                 177        177           530
Steam Requirements, Ib/hr
     Actifier and/or Ejectors      6,240       6,315       18,740     19,180
     Condensate Treatment          1,120       1,120        3,380      3,380
Total                              7,360       7,435       22,120     22,560

Claus Steam Credits, Ib/hr
     High Pressure  (150 psig)        558        577         1,674      1,730
     Low Pressure   ( 30 psig)        282        292           846        875
Total                                840        869         2,520      2,605
Net Process Steam Demand Ib/hr     6,520       6,566       19,550     19,955
                                      -103-

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                   TABLE 7-3,  VACUUM CARBONATE CAPITAL COSTS
                                                             (40)
Removal Efficiency
Desulfurization Installed:
     Capital Cost, $MM
 20 MMSCFD
90%    93%
1.38   1.43
 60 MMSCFD
90%    93%
2.56   2.77
Glaus Sulfur Recovery:
     Installed Capital Cost, $MM
0.53   0.53
0.73   0.73
Total Installed:
     Capital Costs, $MM
1,91   1.96
3,29   3.50
NOTES:  1.  Inlet gas concentration is based on 500 grains H2S/100 SCF.
        2.  Cost data are based on 1974 costs.
                                      -104-

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Several versions of the potassium carbonate p- ^cesses are available.  The hot
potassium carbonate process was previously developed by the U. S. Bureau of
Mines.  The Benfield and Catacarb are very similar to the hot potassium process,
except that they employ a proprietary catalyst to increase the rate of
absorption and stripping, thus further decreasing the circulation rates of the
carbonate solution.  These newer carbonate processes are being considered for
desulfurization of coal conversion gases because of their better economics.

Sulfiban Desulfurization Process
     The Sulfiban process is a joint development of Bethlehem Steel and Black,
Sivalls and Bryson.
     Although the Sulfibaa process was not introduced until 1972, the use of
Sulfiban absorbing solution (alkanolamines) to sweeten natural and manufactured
gases had been practiced for decades.  Monoethanolamine (MEA) is preferred
over diethanolamine for the desulfurization of coke oven gas, since it lends
itself to reclamation in a sidestream reclaimer.
Chemical Reactions—
     The H^S, HCN, organic sulfides and a portion of the CO- are chemically
absorbed in MEA as follows:
                   HCN
                   co2
                                         RNH3HS
     When heat is applied in the regenerator stripper, the above reactions are
reversed, freeing the acid gas.  However, reactions between MEA and organic
sulfides such as COS and CS~ are not reversible.  Also, if oxygen is present
in the system, an irreversible side reaction will take place between the MEA,
HCN and 0? producing amine thiocyanates and thiosulfates.
Process Description—
     The Sulfiban process is operationally similar to the Vacuum Carbonate
process with the single exception that the actifier operates at atmospheric
pressure and about 230 F.  As a r<
process steam (at least 30 psig).
pressure and about 230 F.  As a result, heat must be supplied in the form of
                                     -105-

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     The sour coke oven gas is contacted counter-currently (see Figure 7-2)
with a 13 to 18 weight percent aqueous solution of MEA in an absorption
column.  The resulting foul solution is regenerated with steam in an actifier.
The acid gases from the actifier typically contain 35 to 45 mole percent
hydrogen sulfide, 55 to 60 mole percent carbon dioxide, and 2 to 4 mole percent
hydrogen cyanide, together with fractional percentages of organic sulfur
compounds (primarily carbon disulfide and carbonyl sulfide).
     After counter-current contact with the coke oven gas, the fouled solution
passes through a series of heat recovery exchangers on its way to the actifier.
The actifier overhead, consisting primarily of water vapor and acid gas, is
passed through a condenser and into an accumulator where separation of the
condensables occurs.  The acid gas vapors pass on to the sulfur recovery
system, and the condensate is returned to the actifier as reflux.
     After passing down the actifier, the MEA solution enters a steam-fired
reboiler, where additional stripping occurs (primarily of carbon dioxide), and
stripping steam for the actifier is generated.  A sidestream from the reboiler
enters a reclaimer fired by higher-pressure steam, in which the MEA is vaporized
and returned to the system and the non-volatile components are removed from
the circulating solution.  The bulk of the reboiler effluent passes to a surge
tank, from which it is returned to the absorber via the solution heat exchangers
and cooler.
     Sulfiban pilot plant studies have demonstrated a clear capability for COG
desulfurization to EJS concentrations of 10 grains/100 scf or less.  Efficiencies
range between 90 and 98 percent.
     Only one liquid waste stream of consequence *s produced in the Sulfiban
plant; spent absorbing solution accumulates as a sludge in the actifier
reboiler and must be discharged periodically.   Pilot plant data indicate that
about 37 gal/day of sludge containing FeS, iron ferrocyanide, thiourea, etc.
will have to be removed from a plant producing 60 MM SCFD of coke oven gas.
     Sulfiban operating requirements are given in Table 7-4 for 20 MM SCFD and
60 MM SCFD plants.  Cost data for the plants are presented in Table 7-5.
Applications—
     The Sulfiban is a basic amine process (MEA) which has been used as a
standard in the gas purification/removal industry.  It has been applied in the

                                    -106-

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                                                         CONDENSER
       SWEET COKE-OVEN GAS
         ABSORBER
SOUR COKE-OVEN GAS
                                                                                 ACID GAS
                                                                             H.P STM


                                                                             RECLAIMER
                                                                SLUDGE
                                                               DISCHARGE
                            Figure 7-2.  Sulfiban desulfurization process„

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               TABLE 7-4.  SULFIBAN OPERATING REQUIREMENTS   ^
                                           20 MMSCFD           60 MMSCFD
Efficiency                                90%      98%        90%      98%
Cooling Water, GPM                         530    1,060      1,590    3,180
Power, KW-Hr/Day                         1,300    1,300      4,148    4,148
Monoethanolamine (100%), Ib/day            300      300        900      900
Steam Requirements, Ib/hr:  Actifier     5,840   10,914     17,520   32,746
Claus Steam Credits, Ib/hr:
    High Pressure (150 psig)               558      607      1,674    1,824
    Low Pressure  ( 30 psig)               282      307        846      922
            TOTAL                          840      914      2,520    2,746

NET PROCESS STEAM DEMAND
    Ib/hr                                5,000   10,000     15,000    3,000
NOTE:  Basis - 500 grains H2S/100 scf at inlet.
                                       -108-

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                  TABLE 7-5.  SULFIBAN - CAPITAL COSTS
                                                      (40)
Efficiency
Desulfurization Installed:
    Capital Cost, $MM
  20 MMSCFD
 90%     98%
1,27    1.42
                                                              60 MMSCFD
 90%
2.5
 98%
2.8
Claus Sulfur Recovery:
    Installed Capital Cost, $MM
0.55    0,55
0,70     0.70
HCN Pretreatment:
    Installed Capital Cost
    (via catalytic decomposition), $MM   0,20    0.20
                   0.25     0.25
TOTAL INSTALLED CAPITAL COSTS, $MM
2,02    2,17
3.45     3.75
NOTES:  1.  Basis - 500 grains lUS/lOO scf at inlet,
        2.  1974 costs data.
                                      -109-

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desulfurization of coke oven gas, refinery gas, natural gas, and in the
manufacture of synthesis gas and hydrogen (more than 100 plants have been
built world wide by Black, Sivalls and Bryson).
     The Sulfiban process will have applicability in the U.S. coal conversion
processes especially for the removal of H.-S and C0» from low pressure raw
product and off-gases.  Since the process removes organic sulfides by
irreversible chemical reactions, solvent make up is required by the process.
The temperature of the feed gas has to be below 100 F.

Iron Oxide Process
     The Iron Oxide or Dry Box process is one of the oldest gas treating
techniques known.  The process has found widespread use in some European
countries where essentially complete H.S removal is necessary and where some
manufactured and synthesis gases contain impurities which react irreversibly
with chemicals used in liquid purification processes.  The process is usually
limited to treating gases of small to medium volumes and containing 1.5 volume
percent H_S or less.
     Advantages of the process are essentially complete H_S removal, ease of
operation and simplicity of installation.  Disadvantages are:  1) the sulfur
removed by the process cannot be recovered economically; and 2) large amounts
of labor are required during periodic bed replacement and solid wastes disposal.
For these reasons, the Iron Oxide process will have very limited application
in coal conversion processes.  Example of a possible application is the
treatment of low volume sour gases produced by the byproduct upgrading plants
which are remotely located from the main sulfur removal plant of the coal
conversion process.
Chemical Reactions—
     (1)  Reaction:      2Fe2°3  +  6H2S  	*"  2Fe2S3  +  6H20
     (2)  Regeneration:  2Fe2S3  +  302   	*-  2Fe2°3  +  6S
          Overall:       6H2S    +  302   	+•  6H20    +  6S

Process Description—
     Dry Box purification is the removal of hydrogen sulfide from gas by
bringing the gas into contact with iron oxide in the presence of water.  The

                                    -110-

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efficiency and economy of sulfur removal are dependent upon the activity,
capacity and availability of the oxide used, the ease with which the gas can
be passed through the bed containing the oxide, and upon certain conditions of
temperature and moisture.  Hydrogen sulfide removal is quite exceptional for
small gas volumes; a sweetened gas of less than 0.1 grain H.S/100 scf is
easily obtained.
     The process uses wood shavings impregnated with ferric oxide in hydrated
form.  The bed is gradually deactivated by formation of ferric sulfide and can
be partially regenerated by air oxidation of the ferric sulfide to ferric
oxide and sulfur.  However, eventually the bed becomes plugged with sulfur and
must be replaced.  If a batch-type regeneration is employed, about 4 regen-
erations are possible before the beds of iron sponge must be changed.  Two or
more towers or iron oxide boxes are utilized.
     In general, the sulfur is not recovered from the sponge beds.  The process
removes no C0_.
     There is no theoretical basis for the design procedure, but several
empirical rules can be followed:
     1.   The tower or box should be of such a horizontal cross-section as to
          limit sulfur deposition to a maximum of 15 grains per square foot of
          bed cross-sectional area per minute.
     2.   The operating temperature of the bed should always be below 105 F.
          Otherwise, the water of crystallization in the Fe2°3 molecule will
          be driven off and the activity of the material destroyed.
     3.   The height of the tower or box is recommended to be at least 10 feet
          to produce a pressure drop sufficient for proper gas distribution
          over the entire cross-sectional area of the tower.
     4.   Sponge mixtures containing 5 to 10 Ibs of Fe-O-a per cubic foot are
          satisfactory, and it is customary to figure on 6 cubic feet of
          sponge per 100 SCFD.
     5.   The sponge does not function properly if it contains less than 17
          percent moisture, or more than 55 percent.  A desirable moisture
          content is between 30 and 50 percent.  The function of the water in
          the tower or box is to act as a differential solvent for the H_S,
                                     -111-

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          and to hold it for a sufficient time for the oxide to react with it.
          A further function of the water is to furnish sufficient drops to
          dissolve and remove from the tower or box the soluble salts formed
          during purification.
     6.   The theoretical maximum for sulfur removal per cubic foot of sponge
          is 5.8 pounds.  This is based on 10 pounds of iron-oxide per cubic
          foot of sponge mixture.

Stretford Sulfur Recovery Process
     The Stretford process was originally developed to overcome some of the
shortcomings of earlier absorption/oxidation processes.  The process is capable
of reducing the H S content in coke oven gas to less than 10 grains/100 scf.
Sulfur recovery between 98 and 99.percent is possible.  The process does not
remove organic sulfur, and requires pretreatment for removal of large quantities
of S0_, HCN, or heavy hydrocarbons.  It produces a wastewater stream containing
Stretford solution which requires treatment.
Chemical Reactions—
     (1)  H_S absorption:
             H9S  +  Na.CO,  	^  NaHS  +  NaHCO,
              £        *m  3                                       J
     (2)  Vanadium reduction and sulfur formation:
             4NaV03  +  2NaHS  +  H20  	+>  Na^O   +  2S  +  4NaOH

     (3)  Vanadate reoxidation with anthraquinone disulfonic acid (ADA):
             Na2V409  +  2NaOH  H20  +  2ADA  —*•  4NaV03  +  2ADA (reduced)

     (4)  ADA reoxidation:
             2ADA (reduced)  +  02  	^  2ADA  +  2H20
Major Side Reactions—
     (1)  Thiosulfate formation:
             2NaHS  +  202  	+•  ,Na2S203  +  H20
     (2)  Cyanide conversion to sodium thiocyanate:
             HCN  +  NaHS  +  1/2 02  	»•  NaCNS  +  H20
                                     -112-

-------
     (3)  Sulfur dioxide conversion to sodium sulfate:
                                              Na2S°3  +  2NaHC°3
                         1/2
Polysulfide Pretreatment Reactions —
     (1)  (NH)S     +  HCN  +  ^
     (2)
Process Description—
     The raw coke oven gas (COG) is first pretreated to remove hydrogen cyanide
in a counter-current absorber with a solution of ammonium or sodium polysulfide,
The polysulfide reacts with the hydrogen cyanide in the coke oven gas to form
thiocyanate.  The spent polysulfide is regenerated by the reaction of the wash
solution with elemental sulfur (see pretreatment reactions above).  Fresh
polysulfide solution is continually added to the wash solution, and a purge
stream of the spent wash solution is sent to waste treatment.  The cyanide
absorber can have an efficiency of between 90 to 97 percent.
     The cyanide-free COG is then scrubbed (see Figure 7-3) in an absorber by
counter-current washing with an aqueous solution of sodium carbonate,
anthraquinone disulfonic acid (ADA), citric acid, and sodium meta-vanadate.
The hydrogen sulfide initially dissolves in the wash solution and is then
rapidly oxidized by the vanadate ion to elemental sulfur.  The vanadate ion is
reduced to the vanadous state, which is returned to its original form by the
ADA.  The now sweetened COG passes into the distribution system.
     Underneath the absorber there is a delay (reaction) tank where a liquid
residence time of 10 to 20 minutes is maintained to allow complete conversion
of the hydrosulfide to elemental sulfur.
     The spent solution passes into an oxidizer, where air (up to 400 percent
excess) is bubbled through the solution to reoxidize the ADA.  The rising air
bubbles also carry the suspended sulfur particles to the surface, where they
form a froth (6 to 8 percent sulfur) which is skimmed off.  Underflow goes to
a surge tank and is eventually recycled to the H_S absorber.  A purge stream
containing contaminated Stretford solution is withdrawn from the surge tank
and sent to waste treatment.

                                     -113-

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SWEETENED COKf OVEN OAS
 ACIO OAS IN
   H2S
 ABSORBER
    a
 REACTION
   TANK —
             X
     STRETFORD
     SOLUTION-
    MAKE-UP CHEMICALS
    MAKE-UP WATER
                                              EXCESS AIR
                                     OXIDIZE*
                                   V V. V  v/
                                                         FROTH
                                       OXIDATION
                                         AIR
                 J
                          X
  ~CENTRIFUGE
    FEED TANK
SLURRY FEEDp.
                  FILTRATE SOLUTION
                                                                  WATER
PUMP TANK
                                                 •CENTRIFUGE
     -•>
       I
	_J
                                                                                   SO
     yps
                                              AUTOCLAVE
                                              FEED TANK
                                                              [ 'AUTOCLAVE.  \ W SULFUR
                                                              1 \ SEPARATOR JT SLURRY
                          I

                                                                  COND.
                               SULFUR
                              PRODUCT
                                                                                      WASH
                                  PURGE TO WASTE TREATMENT
                       Figure 7-3.   Stratford sulfur recovery process flow diagram.

-------
     Sulfur Recovery—A number of methods are available for handling the
sulfur froth.  Some of the alternative sulfur recovery methods, and the final
product form, are:
     1.   Filtration, yielding sulfur cake;
     2.   Centrifugation, yielding sulfur cake;
     3.   Filtration or Centrifugation followed by autoclaving and separation,
          yielding high purity molten sulfur; and
     4.   Filtration or Centrifugation followed by direct injection steam
          melting and separation, yielding high purity molten sulfur.
     When sulfur is to be recovered by filtration, a rotary vacuum drum filter
is generally used.  The filter cake produced contains 50 to 60 percent solids.
One or more wash cycles are employed to remove solution components from the
cake.  The filtrate and wash are collected and returned to the system.
     Continuous centrifuges may be employed for higher throughput.  Again, the
filtrate and wash are returned to the system for reuse of valuable components
in the liquor.
     Sulfur cake, or sulfur cake reslurried in water, can be fed to an autoclave
melter-separator.  The melter-separator is a vessel with a jacket or internal
coil that is heated by steam at about 40 psig.  Sulfur melts (at the operating
conditions of 25 psig and 266 F) and is separated from the aqueous layer
containing the Stretford solution components.  The molten sulfur is pumped to
storage and recovered liquor is returned to the system.  It has been reported
that part of the ADA that enters the autoclave is desulfona.ted at the elevated
temperatures to 2,7-dihydroxyanthraquinone.  This compound must then be
separated and purged from the system.
     Direct injection sulfur melting is similar to that described above except
that steam is used directly rather than indirect coil or jacket heating.
     Sulfur recovered by any of the above methods should be of a typical
purity of 99.5 percent or better.
Stretford Process Wastewater Treatment—
     Treatment of Polysulfide Pretreatment Purge Stream—The purge stream from
the polysulfide pretreatment contains large concentrations of  thiocyanate,
polysulfide, ammonia, sulfide and elemental sulfur.  Two processes have been
investigated with success on a laboratory scale for the treatment of these
wastes:  (1) combustion and (2) decomposition.

                                     -115-

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     When combustion is performed in an excess of air, sodium sulfate is
formed as a combustion product; whereas with a deficiency of air, sodium
sulfide and sodium sulfite are formed.  If sufficient sodium is not present in
the aqueous waste, caustic must be added to the feed stream.
     The Ralph M. Parsons Co. has developed a process to decompose the poly-
sulfide process wastes by catalytic hydrogenation.  The process converts the
wastes to NH_, H_S and CO which can be returned to the coke oven gas stream.
No large treatment plant has been built based on this process.
     Treatment of Stretford Purge Stream—The contaminated Stretford solution
purge stream contains large amounts of pollutants similar to the polysulfide
pretreatment waste.  It has been treated according to the following three
methods:
     1.   Combustion,
     2.   High temperature hydrolysis, and
     3.   Carbon adsorption followed by ion exchange.
     The combustion disposal method is essentially the same as that described
above for the treatment of polysulfide pretreatment wastes.  Although com-
bustion is effective, the other two -methods are potentially attractive since
costly reagents can be recovered and recycled to the process.
     The high temperature hydrolysis process has been developed by Woodall
Duckham Limited.  In this process, both the Stretford purge stream and the
polysulfide pretreatment waste can be treated to recover vanadium, sodium
carbonate, and some sodium sulfide and sulfate; and to break down all of the
thiocyanate and most of the thiosulfate in the effluent.
     In the Woodall Duckham process the wastewater is first concentrated in an
evaporator.  The concentrated solution is next fed to a high-temperature
hydrolyzer where the solution is evaporated to dryness and decomposed in a
reducing environment.  The reducing atmosphere is produced by combustion of
fuel, e.g., coke oven gas.  Gases leaving the hydrolyzer are cleaned of solids
in cyclones and then fed to the Stretford absorber.  The solids recovered from
the cyclones, containing vanadium and sodium salts, are dissolved and recycled
to the Stretford plant.
     A U.S. patent was issued in May, 1974 to the North Western Gas Board for
                                                                      (45)
a process to recover ADA and vanadium salt from Stretford waste liquor
                                     -116-

-------
The process uses carbon adsorption and ion exchange to selectively remove ADA
and vanadium salts, respectively.  The materials are recovered upon regeneration
of the beds.  It is not known if the process has been t-ied commercially.
     In the process, the Stretford effluent, adjusted to a pH in the range of
2.5 to 3, is passed through an adsorbent bed containing activated carbon.  ADA
and dihydroxyanthraquinone are adsorbed and retained in the bed.  The solution
then enters an ion exchange bed where vanadium compounds are removed.  In the
above mentioned pH range, an anion exchange resin of the modified polystyrene
type is reported to be suitable.
     The activated carbon and the anion exchange resin may be regenerated for
reuse.  This is achieved in the case of the carbon by washing the bed with hot
water, dilute sodium hydroxide or alkaline sodium dithionite.  This removes
the adsorbed anthraquinone compounds from the bed.  ADA is separated from the
dihydroxyanthraquinone and recycled back to the process.  The dihydroxyanthra-
quinone is discarded.
     Regeneration of the ion exchange resin is accomplished by passing sodium
hydroxide through the bed.  Vanadate ion is eluted from the bed as sodium
vanadate and returned to the Stretford plant.
Economics and Applications—
     Capital and operating costs for the Stretford process are affected by
many variables.  These include:  inlet gas composition, operating pressure,
outlet gas purity, pretreatment and waste treatment requirements.  Generalized
economic analyses, therefore, can be misleading.
     Table 7-6 presents cost data for 20 MM SCFD and 60 MM SCFD coke oven gas
plants.  A 5,000 TPD coal-fired low-Btu gas production facility burning
2 percent (by wt) sulfur with a gas volume of 60,000 SCFM is operated by
Combustion Engineering in Windsor, Conn., and utilizes Stretford capital
equipment estimated to cost three million dollars (1978 costs).
     Major applications of the Stretford process include the desulfurization
of:  refinery and petrochemical off-gases, coke oven gas, flexicoking fuel
gas, Claus tail gas, fluidized bed combustion of coal and coal gasification/
liquefaction off-gases.  Currently, over 50 plants are utilizing the Stretford
process including several coal conversion plants.  The process is operating in
a commercial coal conversion plant in Sasol, South Africa.  Several developing
                                     -117-

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    TABLE 7-6,  STRETFORD DESULFURIZATION - CAPITAL & OPERATING COSTS
                                                                     (40)
ITEM
Operating Costs
    Power, 1.4c/KWHR
    Cool. H20, 12c/M Gal
    Steam $1.50/M Ib
    Chemical Makeup, $/day
   (W/0 HCN or Effluent Treatment)
20 MMSCFD     60 MMSCFD     60 MMSCFD*
 $64.60

  43.20
  53.36
$186.20

  95.04
 150,08
                                                                    $252.00
                                                                       2.16
                                                                     237.60
                                                                     668.28
Total Installed Capital Costs
    $ MM
                                         1.45
                  2.88
                  3.45
*  Integrated system includes Woodall-Duckham wastewater effluent treatment
   and no polysulfide pretreatment equipment.
NOTE:  Basis - 500 grain H-S/100 SCF.
                                      -118-

-------
coal conversion processes are also employing it.  They are:  the Synthane
pilot plant at the Pittsburgh Energy Research Center; the Combustion Engi-
neering low Btu gasification facility in Windsor, Conn.; the SRC pilot plant
at Tacoma, Washington; and the DOE-owned Cresap test facility.  Several Lurgi
based commercial coal gasification plants under design conditions in the U.S.
(e.g., El Paso and WESCO plants) have utilized Stretford to remove H_S from
Claus tail gas and low-H_S containing off-gas from the Rectisol acid gas
removal process.  The Stretford process is suitable for gas streams with low
H9S (less than 15 percent) concentrations.

Claus Sulfur Recovery Process
     The Claus process has been used in several coke oven plants to recover
elemental sulfur from the coke oven gases.  Operating experiences of three
                                                           (34)
Bethlehem Steel Corporation plants were recently published     .  It was found
that certain process modifications were necessary due to the effect of chemical
components present in the coke oven gas which are not typical  of the Claus
plant application for petroleum derived gases.  The constituents are hydrogen
cyanide, tar, naphthalene, hydrocarbons, organic sulfur, etc.  Since these
components are also present in the coal conversion acid gases, Claus plant
experiences from the coke oven application could be useful.
     Elemental sulfur is produced in the process by the Claus  reaction between
hydrogen sulfide and sulfur dioxide which yields sulfur and water, as follows:
                         Cat
          2H S + SO,  «        3S + 2H0
            £,
                   £-
The S07 is supplied either by burning one-third of  the H^S-containing acid gas
in a slip-stream and recombining the gases, or by reacting  the total acid gas
with a limited amount of air.  When the acid gas feed to  the Claus plant is a
lean stream, i.e., 25 to 35 vol percent H_S in the  feed,  the slip-stream
scheme is favored.  For rich acid gas feed, the latter technique is more cost
effective.  (Note:  Most of the Claus plants in the coke  oven industry follow
this technique.)
     Figure 7-4 shows a flow diagram of a  typical Claus plant in the coke oven
industry.  The plant consists of:
     1.   A furnace section where the SO-  reactants are produced by burning
          the H^S-containing feed gas.  Also, a substantial amount of sulfur
          is formed in this section by non-catalytic reaction of hydrogen
          sulfide and sulfur dioxide.

                                     -119-

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         BURNER a THERMAL REACTOR
                                          rHOT OAS BYPASS REHEATS
                                                                        TO ATM
ACID OAS
    HEAT
RECOVERY UNIT
                           50% OF TOTAL
                           SULFUR PRODUCED
                                            SULFUR STORAGE TANK

                                                                                                FLUE GAS
                                                                                                AIM
                                                                                      ICOALESCCR
                           Figure 7-4.  Glaus sulfur recovery process.

-------
     2.    A series of catalytic reaction zones where the Glaus reaction proceeds
          to a further degree of completion.  This section consists of a
          repetition of three basic steps:  reaction, cooling and condensing
          of sulfur, and reheating of gas going to the next reactor.
     Typical compositions of acid gas feeds (produced by Vacuum Carbonate
systems) to the three Glaus plants operating at Bethlehem Steel coke oven
plants are shown in Table 7-7.  Using these rich feed streams and a Glaus
process that contains a furnace section and three catalytic converter steps,
the Bethlehem Steel experience has demonstrated sulfur recovery efficiencies
of 95 to 96 percent.
     Approximately 50 percent of the total sulfur production occurs in the
thermal section (furnace and waste heat recovery); sulfur made in the three
reactor/condenser passes is 40 percent, 8 percent and 2 percent of  the total
production, respectively.
     The tail gas quantity from the above process is approximately  1.77 times
the volumetric flow rate of the acid gas feed.  Substantial amounts of sulfur
compounds will be present in the tail gas, e.g., 2,200 ppmv of H^S, 1,500 ppmv
of COS, 1,300 ppmv of SO  and 100 ppmv of CS_.  Therefore, the tail gas is
incinerated to convert more odorous and toxic sulfur compounds to S0», before
discharge to the atmosphere.  Other types of tail gas control systems do not
appear to be used in the coke oven industry according to our literature review.
     The organic sulfur compounds in the tail gas originate from many side
reactions in the Claus process involving carbon dioxide, hydrocarbons, carbon
monoxide, hydrogen sulfide and sulfur dioxides.  Some of these reactions are
given below:
CO,, H
2
CO H
CH H
4
CS2 H
CH H


1- 1/2 S2 ~

h SO —




h 2, S ^^
•- cos

Si*: cos

-••** cos

*• r.os


fc r.s^
Increasing the CO- and hydrocarbons  present in the feed gas to the  Claus  unit,
will increase the amount of  COS  and  CS_  present in the tail gas.  The  effect

                                      -121-

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                                                                        (34)
  TABLE 7-7.  TYPICAL CLAUS PLANT FEED COMPOSITION FOR THE COKE INDUSTRY
                                         Composition in Vol %

    Component              Plant A             Plant B             Plant C

Hydrogen sulfide            69.20               78.97               77.82
Carbon dioxide               8.28               15.43                9.71
Hydrogen cyanide            19.99                0.35                7.71
Carbon disulfide             0.04                0.48                0.29
Sulfur dioxide               0.02                0.08                0.09
Toluene                      0.11                0.03                0.05
Benzene                      0.83                0.11                0.05
Ethylene                      -                  0.50                0.41
Methane                      0.33                1.91                0.68
Oxygen                        -                   -                  0.29
Nitrogen                     0.17                2.04                2.81
Argon                        0.28                0.04                0.09
Water                        0.85                0.06
                                  -122-

-------
of the above impurities is more pronounced when the Glaus feed gas is a lean
stream (less than 35 percent H S) .
Effect of Hydrogen Cyanide —
     The hydrogen cyanide in the acid gas feed to the Glaus unit was found to
cause severe corrosion of the burner, sulfur separator vessel and sulfur line.
Analysis of the corrosion products showed that they contained large amounts of
thiocyanates.
     To eliminate the hydrogen cyanide from the acid gas feed to the Glaus
unit, Bethlehem Steel has successfully applied a catalytic oxidation reactor
(cyanide destruct reactor) .  The reactor uses Glaus type catalyst at a
temperature of approximately 500 to 600 F.  Cyanides are destroyed according
to the following:
          HCN  +  H20  - »-  NH3  +  CO
          HCN  +  2HS  +  1/2
     The above system oxidizes 95 percent of the cyanide present in the acid
gas feeding the Glaus plant, thereby eliminating the previous corrosion problems.
     Other systems that have been examined for removing hydrogen cyanide from
the acid gas feed streams are:
     1.   Water washing (scrubbing), Bethlehem Steel,
     2.   Improved Glaus combustion methods, Koppers,  and
     3.   Catalytic hydrolysis, the North Western Gas  Board, U.K.
     Water washing worked but required higher capital  cost  than the catalytic
oxidation process.  Modified Glaus combustion requires a slightly air-rich
condition during Glaus combustion, resulting in lower  sulfur yields.  Catalytic
hydrolysis process encountered catalyst  fouling with the small amounts of tars
present in the acid gas feed.
Economics and Applications —
     The capital cost of a  Glaus plant depends on many factors such as:  the
concentration of H S in the gas; the removal efficiencies  (number of  converter
stages); and the concentration of impurities such as hydrocarbons, cyanides
and ammonia.  Costs for coke oven applications  (inlet  gas  concentration of 500
grains per 100 SCF) are given, for two sizes  (20 MM SCFD and  60 MMSCFD) , in
Tables 7-3 and 7-5.  For the larger plant, which will  recover about 20  ton/day
of sulfur, the capital cost is about $730,000  (1974 costs).
                                     -123-

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     For a Glaus sulfur recovery plant needed to recover about 560 ton/day of
sulfur from a 20,000 TPD SRC-I process discussed in Section 6, it was estimated
that the capital cost would be approximately six million dollars (1976 costs).
The cost would be about fourteen million dollars with a tail gas unit (SCOT
process) which is needed to meet air pollution control standards.
     The Glaus process has been used commercially for sulfur recovery from
refinery, coke oven and natural gases.  Although it has not been used in any of
the existing commercial coal gasification plants, it is included in the design
of a number of proposed commercial gasification and liquefaction plants for
gas streams with high H S (more than 15 percent).  The Glaus process has been
used with a number of developing gasification processes, e.g. Hygas, Bigas and
the Lurgi installation at Westfield, Scotland.

WASTEWATER CONTROL TECHNOLOGY
     In Section 4, the principal sources of Byproduct coke plant wastewaters
were identified as ammonia liquor blowdown, final cooler blowdown, light oil
plant (also called benzol) wastewater and coal pile runoff.  Characteristics
of these wastewaters and their counterparts in the coal conversion systems
were discussed in Section 4, 5 and 6.  Since the first three process waste-
water streams come in contact with coke oven gases, they contain large amounts
of the following pollutants:  phenol, ammonia, cyanide, thiocyanate, sulfides,
etc.  The ammonia liquor blowdown stream has the largest concentration of
these and other pollutants.
     Various treatment schemes for these streams are used in the coke oven
industry.  A summary of the important control/disposal methods is given below:
     Light Oil Plant and Final Cooler Wastewaters—Although these streams
contain large amounts of phenol, ammonia and cyanide, a majority of the plants
send these streams to coke quenching without any treatment.  (Note:  It may be
construed that similar practices would not be permitted in the coal conversion
processes in analogous situations; e.g. ash quenching with dirty process
wastewater.)  A few plants treat these streams similar to the ammonia liquor
blowdown before re-use or discharge to the receiving stream.
     Coal Pile Runoff—A majority of the plants have some kind of control
technology to recover fine coal particles from the runoff.  Since there are no
existing effluent limitations on storm water runoff from the coal pile, no

                                     -124-

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other treatment technology is used.  The EPA, however, has proposed suspended
solids concentration and pH limitations that may be effective in 1983.  Should
these limitations become effective, better settling systems (e.g., with
flocculating chemical addition chambers, and clarification vessels) and pH
controlling vessels will be required.
     Ammonia Liquor Slowdown—Most plants keep this stream segregated from
other low strength wastewaters and treat it extensively before discharge to
the receiving stream.  Phenols and ammonia are removed from the wastewater by
various means.  Steam stripping of ammonia, biological oxidation and/or solvent
extraction of the phenolics and organics are very common treatment technologies.
     Figure 7-5 presents currently employed treatment practices at five coke
oven plants.  All the plants perform extensive treatment of the ammonia liquor
blowdown before discharge to the receiving stream.  The treatment schemes,
however, vary significantly among the different plants.  With the exception of
Plant E, all the plants recycle the final cooler and  the benzol plant (light
oil) wastewaters to coke quenching.  Plant E uses complete physical/chemical
treatment for the ammonia liquor blowdown, final cooler, and benzol plant
wastewaters; carbon adsorption is the significant unit operation in the
treatment scheme.  Summary features of  the treatment  plants are given below:
     Plant A—Waste ammonia liquor, light oil wastewaters and final cooler
wastewaters are treated first in a free-leg ammonia still  (fixed ammonia not
removed), and subsequently, with a proprietary solvent extraction process for
phenol removal before discharge to receiving stream.
     Plant B—Waste ammonia liquor, after dilution with non-contact cooling
water, is treated via the activated sludge system and clarification,  followed
by discharge to the receiving stream.   Final cooler and benzol plant waste-
waters are sent to coke quenching for complete evaporation.
     Plant C—Waste ammonia liquor is treated via solvent extraction  of phenol
followed by ammonia stripping (fixed ammonia released by  lime treatment)
before discharge to a municipal facility.  Final cooler and  light oil waste-
waters are sent to coke quenching for complete evaporation.
     Plant D—Waste ammonia liquor is first  treated in a  stripping tower for
H S removal; next, phenol is removed by solvent extraction;  and,  finally,
ammonia is removed by steam stripping  (fixed ammonia  released by  lime treatment) .
                                     -125-

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            I	*-NH3 RECOVERY
PHENOL
AMMOffA LIQUOR^
SLOWDOWN
FREE LEG
NH3 STRIPPING


SOLVENT
EXTRACTION
1 	 	 -.,..- CTFAM


                         PLANT A
                (NON-CONTACT COOLING WATER)
                         PLANTS
AMMONIA UQUOR
SLOWDOWN
ACTIVATED
SLUDGE
T

nit i rrirtu UIATTD
CLARIFIER



                                                                   DISCHARGE
AMMONIA LIQUOR
SLOWDOWN
PHENOL
SOLVENT
EXTRACTION



NH3
LIME TREATMENT a
NH3 STRIPPING
LIME STEAM


                         PLANT C
Figure 7-5 (Pg.  1 of 2).  Coke plant wastewater treatment systems.

-------
VA
AMMONIA LIQUOR
SLOWDOWN
POR TO DESULFURIZER
STRIPPING


PHENOL
SOLVENT
EXTRACTION


NH3
LIME TREATMENT a
STEAM STRIPPING


                                                LIME
•STEAM
                       PLANT D
AMMONIA LIQUOR
SLOWDOWN


SOLVENT
EXTRACTION
ncnui-


CARBON
ADSORPTION



AMMONIA
STRIPPING


                                                   No OH
 STEAM
                                      OIL
RNAL COOLER 8
LIGHT OIL PLANT
WASTEWATER
ACID
TREATMENT


DISSOLVED
AIR FLOTATION
^

CARBON
ADSORPTION
k-

                                                                                 RECYCLE TO
                                                                                 COKE QUENCHING
             SPENT PICKLE
               LIQUOR
                       PLANT E
Figure 7-5 (Pg.  2  of 2).  Coke plant wastewater  treatment systems.

-------
Before discharge to the receiving stream, the treated process wastewater is
mixed with once-through, non-contact cooling water.  The quantities of the
treated process wastewater and the cooling water are 60 gpm and 5,220 gpm,
respectively.  (Note: Bibliography 21, from which the above information was
obtained, gave data based on the composite effluent stream.  The data shown in
Table 7-8 are based on the ammonia liquor wastewater only.)
     Plant E—Phenol is removed from the waste ammonia liquor by solvent
extraction (which reduces the phenol loading from 1,600 mg/1 to 30 mg/1)
followed by an activated carbon system.  Ammonia is next removed by steam
stripping.  Final cooler and light oil plant wastewaters are treated with
spent pickle liquor (and caustic soda, if necessary, for pH adjustment)
followed by dissolved air flotation.  The wastewaters are next treated in an
activated carbon system before recycling for coke quenching.  Both the carbon
absorption systems are preceded by a multimedia filter.
     Table 7-8 gives the wastewater characteristics of the feed going to the
different treatment plants described above.  Table 7-9 gives the overall
removal efficiency of the different pollutants by the treatment schemes.
     Steam stripping of wastewater 'specifically to remove hydrogen sulfide is
not generally practiced in the coke oven industry.  In Figure 7-5, Plant D is
shown to have a H^S stripper.  However, no removal efficiency or design
information was available in the literature.
     Other variations and new control technologies are being applied in
wastewater treatment.  Some of these developments are discussed below.
     Ammonia can be removed economically by the Phosam-W Process, details of
which are given later in this section.  Ion exchange has been tried for ammonia
removal but the cost is excessive.  A new development in recovery of coke oven
byproducts from ammonia liquor blowdown and coke oven gas is the pairing of
two systems:  the Firma Carl Still desulfurization process (discussed earlier)
and the Phosam-W process.  Armco Steel Co. at Middle town, Ohio is constructing
this plant.  This system will recover anhydrous ammonia from the ammonia
liquor blowdown and the coke oven raw gas, and recover a concentrated sour gas
containing H S, HCN and CO , which will be burned in a sulfuric acid plant to
                                     (18)
produce acid gas and also destroy HCN    .  A commercial wet air oxidation
system, designed to eliminate thiocyanates and cyanides from coke oven waste
liquors, is being purchased by DOFASCO from Zimpro, Inc.  The expected removal
efficiency of the system is 99.9 percent for cyanides.

                                     -128-

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               TABLE 7-8.  CHARACTERISTICS OF BYPRODUCT COKE PLANT
                                AMMONIA LIQUOR
                                          Plant Identification
Flow, gal/ton
Flow, gpm
Ammonia, mg/1
BOD5, mg/1
Cyanide, mg/1
Oil & grease, mg/1
Phenol, mg/1
Sulfide, mg/1
Suspended solids, mg/1
A
139
490
1,900
1,500
102
N/A
450
N/A
N/A
B
127
390
1,380
1,280
110
240
350
629
36
C
41
169
7,330
1,120
91
101
910
197
421
D
46
53
3,900
1,200
N/A
210
610
420
2,300
E
N/A
150
5,000
N/A
20
1,000
1,600
N/A
N/A
             TABLE 7-9.  CONTAMINANT REMOVAL EFFICIENCY OF BYPRODUCT
                           COKE OVEN PLANT TREATMENT FACILITIES
                                      % Overall Removal Efficiency
Ammonia
Cyanide
Phenol
Oil & grease
Suspended solids
Sulfide
A
44.6
95.4
89.6
99.6
N/A
N/A
N/A
B
28.8
98.5
71.8
99.8
99.1
N/A
99.96
C
92.9
47.7
18.4
73.4
80.2
74.4
37.0
D
95.3
61.2
N/A
99.1
99.5
76.6
64.4
E
99.0
N/A
N/A
99.9
99.5
N/A
N/A
                                      -129-

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     Following are the major coke oven wastewater treatment processes, all of
which are applicable to coal conversion waste treatment:
     1.   Ammonia removal and recovery processes (steam stripping followed by
          sulfuric acid treatment to form ammonium sulfate, or Phosam-W
          process producing anhydrous ammonia);
     2.   Biological oxidation;
     3.   Activated carbon adsorption;
     4.   Oil removal processes (API gravity separators and dissolved air
          flotation); and
     5.   Phenol removal processes (solvent extraction, biological oxidation
          and activated carbon adsorption).
     Details of these processes and their operating experiences from coke oven
applications are given below:

Ammonia Removal and Recovery
     Ammonia removal and recovery from the coke oven wastewaters is very
common as already shown in Figure 7-5.  Steam stripping of ammonia from the
wastewater and absorption of the resulting ammonia vapor in the coke oven gas
saturator with sulfuric acid to yield ammonium sulfate as a byproduct is the
most common treatment.  An alternate ammonia recovery process is the Phosam-W,
whereby an anhydrous ammonia byproduct is recovered from the wastewater.  A
few plants strip ammonia from the wastewater and incinerate the resulting
vapors.
Ammonia Stripping—
     The ammonia concentration of the flushing liquor  (ammonia liquor blowdown)
varies between 3,000 to 9,000 mg/1, a concentration range generally found for
the coal conversion process wastes also.  At least half of the ammonia in the
above coke oven wastewater is in the fixed form, mostly as ammonium chlorides
and some as ammonium sulfides, cyanide and thiocyanate, etc.  When the ammonia
liquor blowdown is steam stripped without pH adjustment, only the free ammonia
will be removed as is the case of the "free leg" stripping process.  For
greater ammonia removal, the fixed ammonium is liberated by treating with an
alkali before steam stripping.  Most of the plants use lime for pH adjustment
and freeing ammonia.  A pH of at least 11.0 is required to liberate all fixed
ammonia.  Lime consumption is substantial, being in the order of 1.0 pounds
per ten gallons of wastewater.
                                     -130-

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     Caustic can be used in place of lime for pH adjustment with attendant
higher operating cost.  Plant E in Figure 7-5 was found to use caustic and
claimed the following advantages:
               Stripping steam requirements were reduced by about 50 percent
               over a lime still at the same ammonia removal efficiency,
          .     Accurate pH control was obtained, and
               The disadvantage of a lime sludge disposal problem was
               eliminated.
     Lime treatment followed by steam stripping, however, is the principal
control technology for ammonia in the coke oven industry.
     The ammonia stripping tower consists of a distillation column containing
mostly stripping trays, one or two rectifying trays and a partial condenser
(also called dephlegmator).  The overhead vapor product generally contains
about 25 percent ammonia, which is sent to an existing coke oven saturator
where an ammonium sulfate byproduct is produced.  The tower bottoms contain
around 50 to 100 mg/1 of ammonia when the pH of the feed to the tower is
maintained around 11.0 and adequate steam is used for stripping.  The steam
requirement is between 0.1 to 0.2 Ib per pound of feed to the tower.
     Several types of distillation columns are in use.  The older plants use
bubble cap distillation columns, each containing a "free leg" section and a
"fixed leg" section.  The liquid entering the fixed leg section is treated
with lime to free the fixed ammonia.  Newer plants use various modifications
of the above column or completely new types of distillation trays.
Applications—
     Steam stripping will be used to remove hydrogen sulfide and ammonia from
coal conversion wastewaters whenever the levels of H2S and NH» are high
(approximately 1,000 ppm or greater).  Steam stripping with ammonium sulfate
recovery has been used in a commercial coal conversion complex in Sasol, South
Africa.  All of the commercial coal gasification and liquefaction processes
under design consideration in the U.S. show steam stripping of sour process
wastewaters for ammonia and hydrogen sulfide removal.
Phosam-W Ammonia Removal and Recovery—
     The U.S. Steel Phosam-W process has been in use in a dozen or more
installations around  the world to recover ammonia from coke oven plants.  The
                                     -131-

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process has been used to recover ammonia from both the coke oven gas and the
ammonia liquor wastewater stream.  To recover ammonia from coke oven gas a
scrubber (an absorber) is used to remove ammonia and form an ammonium phosphate
solution, which is then steam stripped to regenerate it for re-use.  The
stripper overhead vapor is next fractionated in a distillation colucn to yield
anhydrous ammonium product.
     To remove and recover ammonia from the ammonia liquor blowdown, the
wastewater is first steam stripped in a sour water stripper (see Figure 7-6).
The rest of the system remains the same.  The stripper overhead vapor is sent
to a scrubber where ammonium phosphate solution is used to absorb ammonia.
The rich solution is thermally regenerated to yield fresh solution for recycle
to the absorber and a vapor containing ammonia and steam.  The vapor stream is
next fractionated to yield anhydrous (99.9% pure) ammonia.
     The treated wastewater from the Phosam-W process will contain about 50
ppm of ammonia provided the fixed ammonia in the wastewater feed is liberated
by pH adjustment to around 11.0.
     The difference between the Phosam-W and the conventional steam stripping
followed by sulfuric acid absorption'is that the former produces anhydrous
ammonia and the latter ammonium sulfate as the recovered byproduct.  Byproduct
utilization and market conditions will dictate which of the two processes is
the preferred one for a particular situation.  Anhydrous ammonia product has
the advantage of easy marketability and higher product value.  Primarily for
this reason, the Phosam-W process has been recommended for application to coal
conversion wastewaters in two recent studies

Biological Oxidation
     Oxidation of dissolved and colloidal organic matter in wastewater by
bacteria and other microoganisms to carbon dioxide and settleable organic
sludge (consisting primarily of dead and live microorganisms) is a net result
of biological oxidation systems.  Various biological treatment systems have
been tested in the pilot plant scale level with the coke oven ammonia liquor
wastewater, e.g., activated sludge, aerated lagoon, trickling filter and
rotating biological contactor.  The activated sludge process has given the
best results, and full scale treatment plants in the coke oven industry are
generally of this type.
                                     -132-

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     SOUR GAS<4
 HtPCUTANK-7
""     ~~L
        FEED
                                 STRIPPER
FRACTIONATOR FEED TANK
                                                                                 V—CAUSTIC
                                                                                 ^    TANK
                    Figure 7-6.  Phosam-W ammonia recovery process.

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     In the activated sludge process, new wastewater after being equalized
 (and neutralized, if necessary) is fed to an aeration or reaction tank where
 sufficient detention time is provided for the oxidation removal of the dissolved
 and colloidal organics.  If the wastewater is nutrient deficient, nitrogen and
 phosphorus are added to the reaction tank in a minimum ratio of 100:5:1 of
 BOD:N:P.  Also, the wastewater feed is admixed in the reaction tank with
 active, microbial solids collected from the secondary settling (clarifier)
 tank that follows the reaction tank.  By controlling the recycle rate and
 concentration, a proper food to biological mass ratio in the reaction tank can
 be maintained.  In an activated sludge system the important design parameters
 are:  detention time in the reaction tank, MLSS concentration, clarifier
 overflow rate and sludge wasting rate.
     An activated sludge system has been operating successfully with the
 ammonia liquor wastewater at Bethlehem Steel Coke Plant, Bethlehem, FA since
 1962.  Since then, other activated sludge systems have been constructed and
 operated with coke plant wastewaters.  Table 7-10 shows the typical design
 parameters and operating data obtained from some actual activated sludge
 systems.
     The Bethlehem coke plant studied the effects of various factors on phenol
                                         (37)
 oxidation by the activated sludge process    .  Phenol loadings, ammonium ion
 concentrations, tar concentrations and temperatures were important variables.
Although phenol loadings of 30 lb/day/100 cu ft could be successfully bio-
 oxidized, the system was difficult to operate due to excessive foaming.  At
 phenol loading rates below about 12 lb/day/100 cu ft and at a phenol-to-sludge
 ratio 0.7 Ib/lb MLSS, the activated sludge system has been operating well.
Phenol removals of 99.8 to 99.9 percent are being achieved.  BOD removal
 efficiency, however, has ranged from 85 to 95 percent.  A portion of the
wastewater organics, therefore, is not readily biodegradable.
     The concentration of ammonia in the reaction tank has a significant
effect on the phenol oxidation rate.  Although ammonia is a nutrient source of
nitrogen for the bacteria, ammonia in concentrations exceeding the range of
1,800 to 2,000 mg/1 has shown a severe inhibitory effect on microbial growth.
Since the coal conversion wastewaters, including the coke oven ammonia liquor,
contain much higher levels of ammonia than the above range, ammonia removal
pretreatment will have to be incorporated before the biological system.
                                     -134-

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     TABLE  7-10.   DESIGN  AND OPERATING CONDITIONS OF SOME COKE PLANT ACTIVATED SLUDGE SYSTEMS
                                CD
(2)
(3)
(4)




1
h->
co
Ln
1



Wastewater Parameters
Influent phenol, mg/1
Effluent phenol, mg/1
BOD removal, %
Operating Conditions
NHg concentration in
aeration tank, mg/1
PH
Temperature °F
F/M, Ibs phenol
per Ib MLSS per day
MLSS, mg/1
Aeration time, hrs
1,400
0.1
85 - 95
2,000
6 - 8
80 - 100
0.7

3,300 - 4,700
56
250 - 475
0.1 - 0.3
H/A
N/A
7 - 8
>70
0,2 - 0.25

2,500 - 3,500
24
260 - 400
0.8 - 3.6
N/A
<1,200
N/A
N/A
N/A

N/A
37
3,000
0.1
N/A
N/A
N/A
N/A
N/A

2,500 - 3,00
114
(1)   Data from Bibliography 37.
(2)   Data from Bibliography  9.
(3)   Data from Bibliography  9.
(4)   Data from Bibliography 37.

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     Dissolved tars present in the hot ammonia liquor adversely affect phenol
 removal by bio-oxidation.  This is probably due to occlusion of the microbial
 cells by precipitated tars.  Storing ammonia liquor at ambient temperature to
 decrease the solubility of the tars or lime treatment of the hot liquor
 followed by clarification prior to biological treatment was found to be a
 satisfactory control technology that solved the problem.
     Temperature at the biological reaction tank has a significant effect on
 phenol oxidation.  The optimum temperature is around 95°F.  Adequate phenol
 removal efficiency is obtained at a temperature range between 70 to 100 F
 range:  99.8 percent in the temperature range of 80 to 95°F and 99.6 percent
 at 70°F or 100°F.
     The Bethlehem Steel Coke Plant wastewater, which has a pH range of 8.3 to
 8.8, is directly fed to the activated sludge system without pH adjustment.
 Dilution of the wastewater is done, however, with cooling water in order to
 reduce the ammonia and dissolved solids concentrations at the biological
 reaction tank.
     Foaming in the aeration tank is an operating problem.  It is controlled
 by antifoam agents along with water -sprays.  The reasons for foaming are not
 fully understood.  Coal mixes, coking practices and phenol loadings have
 effects.  Increased phenol loadings increase foaming.
     Thiocyanates and cyanides generally cause problems in a biological treat-
ment process.  However, although they are present in the coke oven ammonia
 liquor, the activated sludge process has performed smoothly.  This is probably
because of acclimation enhanced by the presence of phenol.  In fact, the
Bethlehem system has been able to degrade about 70 percent of the thiocyanates
by oxidation.  Cyanide oxidation efficiencies, however, have been erratic.
During periods of good thiocyanate oxidation, cyanide reduction through
 (equalization) storage and bio-oxidation was around 70 percent.  Other times,
 efficiencies have been poor.  For consistent cyanide removal to a low level,
alkaline chlorination of the bio-effluent would be necessary.
     Since coal conversion wastewaters are similar to coke oven ammonia liquors,
biological oxidation systems should be applicable to this treatment for the
 removal of phenols and other dissolved organics.  Coal conversion wastewaters,
 especially from low-temperature gasification and liquefaction processes, will
 contain various types of phenolics, some of which have low biodegradability.

                                     -136-

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The activated sludge process applied to these waste streams will probably
require additional detention time and more severe treatment than the coke oven
wastewaters.  The pilot scale bio-test works at the Wilsonville and the Fort
Lewis, Washington, facilities showed this to be true.  The waste treatment
experience at the above two facilities and the trickling filter plant operation
experience at the Sasol Plant complex indicate that biological treatment of
the coal conversion wastewater is practical.  Prior removal of ammonia,
sulfide, and phenolics are, however, suggested pretreatment requirements.
Actual pilot tests with real waste streams from the particular coal conversion
system will be necessary to arrive at optimum design conditions and to ensure
reliable treatment plant operation.

Carbon Adsorption
     Activated carbon treatment of coke plant wastewaters has been successful
in removing phenol, color, COD and BOD in both pilot plant and full scale
wastewater treatment systems.  The first full-scale system went on stream in
1976 at the Cleveland District Coke Plant, a Republic  Steel Corporation  facility.
Figure 7-5, Plant E, shows the block flow diagram of the above treatment
facility.  The ammonia liquor blowdown, containing about 1,600 mg/1 of phenol,
is first dephenolized to a level of 30 mg/1 by solvent extraction before
carbon adsorption is utilized.  Other low strength wastewaters containing
around 40 mg/1 of phenol are treated with activated carbon after oil and
suspended solids removal.
     Phenol concentration in the effluent can be reduced to as low as 0.01
mg/1 by carbon adsorption.  The above plant, however,  is operated to meet
around 1 mg/1 phenol level.  Excellent color removal is attained, which  is not
the case with biological treatment of the coke plant wastewater.  Negligible
cyanide and ammonia removal are obtained, however, from carbon treatment.
     Carbon usage at the Cleveland District Coke Plant is about 5.3 pounds per
                                                                     (44)
1,000 gallons of wastewater.  Other design  conditions  were not given     .
However, in a pilot study to determine the  design conditions of a carbon
adsorption system for the coke plant wastewaters, it was determined that
wastewater contact time of about 60 minutes was necessary; and the wave  front
length was about 5 ft at the test conditions
                                     -137-

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     Advantages of carbon adsorption are many.  It is a physical process which
is not affected by toxic pollutants; and it can handle fluctuations in waste
loads.  Influent wastewater varying from 2 to 30 C did not show much effect on
removal efficiency.  However, carbon is expensive.  Regeneration requires a
lot of energy.  At the Cleveland District Plant, it is felt that the physical-
chemical treatment (Plant E in Figure 7-5) of the coke plant wastewater is
competitive with the physical-biological treatment systems.
     Carbon adsorption probably will have applicability in coal conversion
wastewater treatment, especially for final polishing treatment and pretreatment
of wastestreams that contain toxic and refractory substances.  Due to the
differences in the characteristics of the coal conversion and coke oven waste-
waters, the performance and design conditions might be different.  Laboratory
tests with actual coal conversion wastewater will be necessary (adsorption
isotherm and column runs) before full-scale plant design.
     Some coal conversion systems generate char as a byproduct, which is
utilized in a gasifier, e.g. COED process.  If it could be possible to utilize
the byproduct char as an activated carbon, then carbon treatment of the waste-
water  for that system will become very economical, since regeneration will
not be necessary.  The spent carbon would be combusted/gasified in the usual
manner.  Whether or not char will behave as an activated carbon is to be
determined on a case-by-case basis. The coke or fine coals generated in the
coke oven process, however, has not been successfully used to remove phenol
and dissolved organics from the coke oven wastewaters    .

Oil Removal
     In the coke oven wastewater treatment both API separators and dissolved
air flotation (DAF) systems are used to remove oils.  API separators are used
to remove oils from storm water runoffs and from process wastewaters generated
in the light oil recovery and refining section of the Byproduct coke oven
plant.  Dissolved air flotation is used to remove emulsified oils  (an example
is shown in Figure 7-5, Plant E).
     API gravity separators and DAF systems will be the primary treatment of
oily wastewaters in coal conversion plants.  Such wastewaters include process
wastewaters and storm water runoffs from the coal conversion complex.  All
                                     -138-

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developing coal conversion plants in the U.S. use these types of treatment for
oily-waste waters.  The wastewater treatment systems at the South African and
Yugoslavian Lurgi plant complexes also use them.

Phenol Removal and Recovery
     Phenols are being removed from coke oven weak ammonia liquor by solvent
extraction, steam stripping and/or biological oxidation.  Steam stripping for
phenol removal is not a common treatment application. Phenol forms a minimum
boiling point azeotrope with water at 9.2 percent (by wt.) phenol, and there-
fore, stripping requires large amounts of steam, and proves to be uneconomical.
Biological oxidation removal efficiencies of phenol, as discussed earlier, are
high (99.8 to 99.9%), but requires proper plant design and operation.
Fluctuations in influent phenol composition can create upset conditions in the
biological system.  Solvent extraction, however, can more reliably handle feed
fluctuations and recover byproduct phenol from the waste stream.  Solvent
extraction becomes most economical with highly contaminated streams and with
biological oxidation for dilute streams.  Solvent extraction becomes competitive
with biological oxidation at phenol concentrations of about 1,000 mg/1 (waste
flow rates above 50 gpm).
     The earliest large-scale use of solvent extraction for phenol recovery
from coke oven wastewater was done in Germany.  Benzene or light oil solvent
was used in some processes to extract phenolics.  Regeneration of the benzene
(or light oil) was accomplished with caustic extraction.  The process thus
recovered phenolics as sodium phenolate.  Another process used tricresyl
phosphate as a solvent for phenol extraction.  Both these processes are dis-
cussed in detail in the following sections.
     Newer proprietary processes are presently available for phenol extraction
which claim to be more economical.  These processes use volatile solvents
which are easier to recover during regeneration steps.  The Phenosolvan process
is one which has been used commercially to recover phenol from Lurgi process
gas liquor in South Africa and Yugoslavia  (see Figure 5-2).  This process uses
isopropyl ether as the solvent.  Details of  the Phenosolvan process are dis-
cussed elsewhere     , and therefore, will not be covered here.  The Phenosolvan
process is likely to be used in several of the presently planned coal gasifi-
cation projects in the U.S.
                                     -139-

-------
     Jones and Laughlin Steel Corp. has developed a proprietary solvent
 extraction process which has been used in several coke plants in the U.S.  The
 process can recover 99+ percent pure phenol and generate an effluent containing
 about 1 ppm of phenol.  It uses a Karr reciprocating plate extractor for
 phenol extraction (the type of solvent used is proprietary information), a
 solvent stripper and a distillation column to produce pure phenol.
     To illustrate the types of equipment involved in solvent extraction the
 light oil (benzene) - caustic process and the tricresyl phosphate process, the
 two earliest processes still in use, are discussed in detail in the following
 sections.
 Light Oil - Caustic Process—
     The phenolized ammonia liquor is pumped into the distributor header
 located near the top of the ammonia liquor scrubber (see Figure 7-7).   The
 liquor passes downward through the scrubber and comes in contact with a
 counter-current flow of light oil.  The light oil, having a lower specific
 gravity than the liquor, rises to the top of the column as it extracts  the
 phenol from the liquor.  The ammonia liquor falls to the bass of the column
 and is pumped away for further treatment.
     The phenolized light oil flows out the top of the ammonia liquor scrubber
 to the caustic washer in the caustic treatment tower.
     The caustic treatment tower is divided into three compartments.  The
 bottom chamber is the light oil circulation tank which is the pumping chamber
 for the dephenolized light oil.  The upper two sections are the caustic washing
 compartments, packed with ceramic tile.  In these compartments, the phenolized
 light oil passes through the caustic to remove the phenols by chemical  reaction
 between the caustic and the phenols, as follows:
          C,HCOH  +        NaOH  	*•  C.,HcONa      +   H_0
           o j                                    bo              2.
          phenol     sodium hydroxide        sodium phenolate    water
     The phenolized light oil passes from the ammonia liquor scrubber to the
 distributor header on the No. 1 washer to a distributor header on the No. 2
washer to the overflow line, where the light oil, now dephenolized, is  returned
 to the circulation tank.
     After about a week, the caustic in the No. 1 washer is saturated with
 phenols.  At this point, the recovery operation is shut down so that the spent
 caustic can be replaced by fresh solution.
                                    -140-

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                                                          CAUSTIC CHARGE
DEPHENOLIZED
AMMONIA LIQUOR
                     —WASHER N* 2
                      DEPHENOLIZED LIGHT OIL
                      PHENOLIZED LIGHT OIL
                    AMMONIA LIQUOR
                       SCRUBBER
PHENOLIZED AMMONIA LIQUOR
LIGHT OIL CAUSTIC
   WASHER
                                         MAKE-UP
                                       LIGHT OIL
                                                                       -WASHER N* I

                                                                     ALIGHT OIL
                                                                       CIRCULATION
                                                                       TANK
                                                TO CARBOLATE
                                                "CONCENTRATOR
FROM CAUSTIC
SODA STORAGE
                         Figure 7-7.  Phenol removal by light oil — caustic  process,

-------
     The sodium phenolate in the No. 1 washer is drained into the carbolate
 concentrator.  Then the partially phenolized caustic in the No. 2 washer is
 drained to the No. 1 washer, leaving the No. 2 washer empty to receive a fresh
 supply of caustic soda solution.
     The sodium phenolate in the concentrator is boiled to remove entrained
 solvent and moisture.  It is then neutralized with carbon dioxide to liberate
 crude phenols and phenol homo logs.
     The phenol removal efficiency of this process can be expected to be at 98
 to 99 percent.
 High-Boiling Solvent Process—
     Extraction with a high-boiling solvent allows for direct phenol recovery
 by distillation or possibly by a simple flash operation.  A solvent such as
 tricresyl phosphate has been used in this type of process.  This solvent has a
 distribution coefficient for phenol about 8 times larger than that for benzene,
 and is virtually Immiscible with water (solubility < 15 ppm).  Distillation
 can be used to separate the phenolics from the tricresyl phosphate, and since
 the latter has a very high boiling point (265°C @ 10 mm Hg), vacuum distillation
 should be a simple flash operation where the spent solvent is heated in a
 series of interchangers and exchangers, and flashed across a control valve
 into a tank where the phenols are vaporized and removed from the solvent (see
 Figure 7-8).
     The result of the distillation or flash operation is the recovery of a
 very pure phenol product.  One problem with this process is that less volatile
 phenolics and other organics tend to build up in the recirculated solvent,
 causing problems of increased viscosity and decrersed phenol capacity.  Two
 solutions are possible:  either the process can be shut down and loaded with
 fresh solvent, when necessary, or a continuous purge stream can be removed
 from the system to maintain a steady concentrate of heavier phenolics and
 organics in the solvent.  Disposal of the spent solvent becomes a problem.
When these disposal costs are taken into account, this process becomes less
 attractive for a large size plant.
     The phenol removal efficiency of this process can be expected to be at 95
 to 99 percent, depending upon the design of the system.
                                    -142-

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                                                                   ORGANIC SOLVENT
                                                                      SEPARATOR
                                             RECOVERED
    EXTRACTION
                                                                             •SPENT
                                                                            SOlWNT
                                                                             HEATER
   SOLVENT
STORAGE TANK
                                                                                                     »-S£AL TANK
   PHENOLIZED
                                                                 DEPHENOLIZED
                                                                 AMMONIA LIQUOR
AMMONIA LIQUOR
                                                                     ORGANIC
                SPENT SOLVENT
                   PUMP
  SOLVENT
 FEED PUMP
EFFLUENT
TRANSFER
  PUMP
RECOVERED
 SOLVENT
  PUMP
ORGANIC
REMOVAL
 PUMP
                                Figure 7-8.   Phenol removal  by  high  boiling  solvent  process„

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SOLID WASTE DISPOSAL METHODS
     Most of the sump breeze (coke)  collected from quench water circuits is
sold (primarily, larger size fractions), recycled to the coal pile, or used in
the sinter mix in steel mills.
     Tar sludge obtained from the tar storage tank is usually disposed of by
landfill.  Incineration is an alternate method of disposal.
     Coke oven plants utilizing biological systems to treat wastewater generate
an excess biomass residue which is usually landfilled.
     The coke oven gas desulfurization processes convert the sulfur in the
off-gases to commercial elemental sulfur, sulfate, or sulfuric acid, instead
of producing residues.

LIGHT OIL UPGRADING PROCESSES
     Light oils and coal tars are two of the coke oven byproducts which are
further refined to produce upgraded usable products.  Coal tar processing is
generally done outside the coke oven industry by chemical companies, and
therefore, will not be covered in this report, since it is beyond the scope of
this study.  However, light oil refining is extensively done by the coke oven
industry; consequently, it will be discussed in subsequent paragraphs.
     Coke oven light oil is rich in benzene, toluene, and xylene (BTX).
However, these aromatics are contaminated by various compounds such as paraffins,
naphthenes, olefins and sulfur pollutants (see Table 7-11 for a typical light
oil composition).  These contaminants can be reduced by the following processes:
     1.   Acid treatment followed by caustic soda wash and distillation;
     2.   Hydrogenation followed by extraction and distillation; and
     3.   Hydrodealklation by the LITOL process.
     Acid treatment is the traditional method for purifying light oil.  The
yields of BTX products from this process are lower and the sulfur content of
benzene produced by acid washing is higher  (100 to 400 ppm of thiophene)
compared to the Litol process.
     The multiple steps in the extraction process will produce high quality
aromatics from the light oil.  It appears, however, that the capital and
operating costs of this process will be higher than the LITOL process.  No
commercial plant has been built to upgrade coke oven light oil using this
process.
                                     -144-

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  TABLE 7-11.  TYPICAL RAW LIGHT OIL COMPOSITION
Component                                     Wt  %
Cyclopentadiene                                0.35
CC-C, Non-aromatics                            0.06
 _>  o
Benzene                                       73.46
Thiophene                                      0.44
C-.-Co Non-aromatics                            0.02
 /  o
Toluene                                       14.82
Xylenes & Ethylbenzene                         3.03
Styrene                                        1.55
Carbon Bisulfide                               0.45
Propylbenzene                                  0.05
Mesitylene                                     0.14
Pseudocumene                                   0.25
Dicyclopentadiene                              0.33
Diethylbenzene                                 0.05
Coumarone                                      0.31
Indene & Durene                                1.98
Naphthalene                                    1.83
Dimethylnaphthalene                            0.43
Other Methylnaphthalenes and Higher            0.45
     Homologs of Benzene                     	
                                             100.00
                     -145-

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     The LITOL process, which was developed by the Houdry Division of Air
Products and Chemicals, Inc., has been employed commercially since 1964 to
produce high quality (even reagent grade) benzene from coke oven light oils.
Seven commercial plants have been build worldwide utilizing the LITOL process.
It is anticipated that LITOL will be applied widely for upgrading csal
gasification and liquefaction derived light oils (naphthas) in the future.

LITOL Process
     The Houdry LITOL process is a catalytic process with two principal
reaction zones:  a hydrogenation section, and a hydrocracking/dealkylation/
desulfurization section.  Various chemical reactions occur within the LITOL
reactors.  Figure 7-9 shows some of the major ones.  Hydrodealkylation
reactions dominate, explaining why the Litol process produces mostly high-
quality benzene with very little CQ aromatics.
                                  o
     Figure 7-10 depicts the flow diagram for the LITOL process.  The crude
light oil is pumped to unit pressure (700 to 900 psig), heated to 1,050 to
1,150 F, and vaporized by contact with a hot hydrogen stream.  The vaporized
charge is taken overhead while a small amount of tar (styrene polymer) is
withdrawn as bottoms product.  The overhead vapors flow through a pretreat
reactor for saturation of the remaining styrenes and through a fired heater to
bring the light oil hydrogen stream up to reaction temperature.  The preheated
feed flows through the reactors (which contain a chromia-alumina catalyst),
exchanges heat with the feed streams, and is flashed in a high-pressure flash
drum.
     The non-aromatic materials - mainly paraffins, olefins, diolefins,
naphthenes, and sulfur compounds - are completely converted to lighter hydro-
carbons and to hydrogen sulfide.  Substitute aromatics are partially
hydrodealkylated to produce additional benzene.
     The vapors from the flash drum (after the reactors) divide, a portion
being vented to fuel while the rest are recycled to generate hydrogen.  The
flashed liquid flows to a stabilizer tower for removal of light ends, through
a clay treater for removal of trace olefins and then to product fractionation.
                                     -146-

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HYDRO-CRACKING
1.  CH3-CH(CH3)-CH2-CH(CH3)-CH3   +   H
       2,4- Dimethyl Pentane
2.
    Cyclohexane

       C6H12
    Cyclohexane
                          3H,
                          2H,
          C3H8
         Propane
 3C2H6
Ethane

 2C3H8
Propane
                                                            C4H10
                                                            Butane
HYDRODE ALKYLATION
1.   C-.H      +    H,
      7 8
    Toluene

2'    C8H10
    Ethylbenzene
                                 Me thane
                                     E thane
        Benzene
          C6H6
         Benzene
HYDRODESULFURIZATION
1.    C4H4S      +
    Thiophene
2.       CS2
    Carbon Bisulfide
                      4H
                           4H2
 C4H10
Butane
           H2S
                                        Methane
HYDROGENATION
 1.
      C8H8
    S tyrene
                                  Ethylbenzene
DEHYDROGENATION
    Cyclohexane
                         C6H6
                        Benzene
                                       3H,
                 Figure 7-9.  Typical LITOL reactions.

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               OPTIONAL
               MAKE-UP HYDROGEN
            FUEL GAS
  CRUDE
                    GENERATION a
                    PURIFICATION
LIGHT OIL
            VAPORIZER
       POLYMER
             HOUORY
              LITOL
            REACTORS

                                                                      BENZENE
                                                     TOLUENE
FLASH
DRUM
                                            mo
                                             "

                                       CQ FRACTION
                            te.
                            u

                            o
>
_i
u
2g
N O
!«
                           I*J<
                           ZZ
                           UJQ
                                                                                                    CE
                                                                                                    O
                                                                      u

                                                                      K.
                                                                                                     00
                                                                                                    U
                                                                                                  C9* BOTTOMS
                            Figure 7-10.  Houdry's CITOL light oil upgrading  process.

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     Benzene product is separated from heavier aromatics by conventional
distillation.  The benzene tower bottoms, consisting primarily of toluene, can
be recycled to the process for further conversion or can ba further distilled
to produce a toluene product with recycle of the bottoms from that tower.  An
additional tower can be used to separate C0 aromatics from a heavier Cn
                                          o                           y~t"
fraction.
     The process is a consumer of hydrogen which can be generated readily in a
steam methane reformer using the methane-rich recycle gas stream (flash drum
vapor) as the feed stream.  No outside source of gas is needed to maintain the
required hydrogen balance.  Hydrogen consumption is about 0.47 moles per mole
of benzene product.
     Typical yields from the LITOL process are shown in Table 7-12 for two
cases:  toluene recycle, and no toluene  recycle.  When higher benzene yield is
desired, toluene can be recycled to the  LITOL reactor for conversion to benzene
by hydrodealkylation reaction  (See Figure 7-7).
     The installed capital cost of a LITOL facility to. process 70,000 metric
tons per year of coke oven light oil will be about $8.1 million dollars  (1978
costs) approximately distributed as follows:
               Unit                Installed Capital Cost
          Feed Pretreatment              $  800,000
          Main LITOL                     $4,800,000
          Cryogenic                      $1,300,000
          Hydrogen Generation            $1,200,000
                                         $8,100,000
     The operating costs of the plant are summarized in Table 7-13 which  shows
that the total cost per ton of benzene product is $153.34.  Since the selling
price of benzene is about $180.00 per metric ton, there is an economic incentive
to refine the crude light oil.  An additional benefit of the process is the
removal of sulfur and nitrogen pollutants from the crude light oils which would
contribute to our pollution problems, if not removed by upgrading.  In the
LITOL process, sulfur and nitrogen are converted to hydrogen sulfide and
ammonia, which are subsequently removed  by the purification steps associated
with the hydrogen plant.
                                       -149-

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                     TABLE 7-12.  TYPICAL LITOL PROCESS YIELDS
                       (Basis:  100 Ton of Raw Light Oil Feed)


                             No Toluene Recycle          Toluene Recycle

                         Reactor Feed^  Products  Reactor Feed^   Products

Hydrogen                      0.95           0.10         1.13        0.13
Hydrogen Sulfide                             0.41                     0.41
C1~C5 Hydrocarbons            0.53           6.80         0.59        8.13
C6 Non-Aroma tics              0.59           0.02         0.59        0.02
Cy Non-Aromatics              0.21                        0.21
Benzene                      74.09          86.66        74.09       92.88
Toluene                      19.22           7.36        19.22        0.02
Cg Non-Aromatics              0.09                        0.09
Xylene                        3.12                        3.12
Ethylbenzene                  0.22                        0.22
Styrene                       0.62                        0.62
C9+                           0.70           0.01         0.70        0.01
Thiophene                     1.02           	         1.Q2        	
                            101.36         101.36       101.60      101.60
(1) Includes makeup hydrogen (95 mol% H~ and 5 mol% C, composition)
                                      -150-

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                 TABLE 7-13.  LITOL PROCESS OPERATING COST
             (Basis:  70,000 Metric Tons/yr of Light Oil Feed)
    Item

Feedstock
Utilities
   Fuel
   Power
   Steam
   Cooling Water
   Chemicals & Catalyst
            Sub-total
  Units

$105/M.T.

$8...00/MMKcal
 2.0C/KWH
$7.00/M.T.
 0.8C/M3
              U.S.  $/Metric ton of Benzene

                          142.27

                           11.27
                            1.67
                            1.05
                            0.31
                            0.55
                          157.12
Fixed Cost
   Operating Labor
   Operating Overhead
      Maintenance
      Supplies (including
      Insurance & Taxes
      Depreciation
            Sub-total
$7.00/hr-4 men/shift
 150% of Operating Labor
   4% of Investment

   1% of Investment
  15 years-Straight line
                            4.75
                            7.13
                            6.27
                            0.50
                            1.57
                           10.45
                           30.67
Credit
   Fuel Gas
   Fuel Oil
   Toluene
      TOTAL
            Sub-total
$8.00/MMKcal
  $75/M.T.
 $150/M.T.
                            5.46
                           16.21
                           12.78
                           34.45

                          153.34
NOTE:  LITOL unit feed is 59,750 MTPY after prefractionation.
       51,650 MTPY of benzene and 4,400 MTPY of toluene.
                                  Yields
                                  -151-

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     The LITOL process is expected to have wide application in upgrading coal
conversion system light oils.   It has been considered for upgrading the light
oils (naphthas) that will be produced from the proposed El Paso Lurgi process
Although the BTX concentrations of the naphtha from the referenced plant will
be only 46.8 wt. percent as compared to about 85 percent for the coke oven
light oil, upgrading of the naphtha is still considered to be economic.
     The reason the BTX concentration in the naphtha from the El Paso Lurgi
plant will be about 46.8 percent is that a sub-bituminous type coal will be
used in the process.  If, instead, a bituminous coal similar to the coal fed
to the coke ovens, is used in the Lurgi process, the BTX concentrations in the
Lurgi naphtha will also be about 85 percent.  This dependence of BTX concen-
tration on coal type in the light oil has been proven by the Lurgi gassifi-
cation data.
     At design conditions, 20,000 Ibs/hr of naphtha byproduct will be produced
from the El Paso Lurgi plant.  Processing of this naphtha through the LITOL
system will yield the following products:
                                        Quantities, Ibs/hr
               Benzene -                        8,732
               C +     -                        1,000
               c5-     -                        1,000  .
     The process will require 3,827 Ibs/hr of make-up hydrogen.  Waste streams
from the above LITOL system will contain the following:
          A small stream of sour gas, 827 Ibs/hr, which will contain about
          5 percent H S and 4 percent NH_.
          A small amount of process wastewater, 291 Ibs/hr, which will require
          treatment for ammonia, sulfides and oil removal.

FUGITIVE EMISSIONS CONTROL
     Air pollution control technology (existing and proposed) for the collection
and removal of particulate matter and gaseous emissions in the Byproduct coke
oven industry is discussed in subsequent sections.  Since much of the air
pollution control technology has been or is being developed around the coke
oven batteries and coke quench systems, the major thrust of industry and
manufacturers has been to focus on these areas of the plant for the control
of the more obvious visible particulate matter, and gaseous emissions.

                                     -152-

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     The coke ovens are a major source of air pollution emissions in the steel
industry     .  Topside coke oven workers have a substantially higher risk of
having cancer than the average worker (see Section 8 for details), probably
from carcinogenic materials associated with the particulate fraction of the
coke oven emissions.  Various schemes to control the fugitive emissions and
alleviate potentially adverse health effects are being developed. The Air
Pollution Control Association and the EPA co-sponsored a conference on "Control
of Air Emissions from Coke Plants" which was held in Pittsburgh, PA in April
1979.  In this conference, various fugitive emission control technologies were
discussed which are reflected below.
     Coal charging emissions can be controlled by:  staged charging with coke
oven raw gas evacuation to the gas collecting main; larry cars with gas
capturing equipment (e.g. hoods and ducts) and wet scrubbers; and pipeline
charging (closed charging).  Coking cycle emissions can be minimized by improved
door sealing, but better control is obtained with sheds ducted to air pollution
control devices (e.g scrubbers) whose main purpose is to control pushing (coke
discharging) operation emissions.  Other systems being developed for pushing
emission control are various mobile and fixed duct collection systems
integrated with control devices (e.g. scrubbers, fabric filters, electrostatic
precipitators). Coke quenching emissions can be controlled by the use of a
hooded quench system, or they can be significantly reduced by the use of dry
quenching methods.  A summary of the various coke oven control technologies
for fugitive emissions are shown in Table 7-14.  Many of these control methods
will have applications in the synfuels industry in analogous situations.

Charging Emission Control
     Coal is charged into the coking chamber through charging holes provided
in the roof of the oven.  The oven retort or coking chamber and the heating
system are designed to process a coal charge of definite volume with a level
upper surface approximately one foot below the oven roof.  The coal is charged
from a device called a larry car situated on tracks supported by the battery
top.  The charging of coal into coke ovens results in a fugitive emission
consisting of coal dust, tars and gases from the changing hole. Several types
of control technologies are available to contain emissions during oven charging.
                                      -153-

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                                               TABLE 7-14.   BYPRODUCT COKE OVEN FUGITIVE EMISSIONS CONTROL
     Operation/Emission
     	Source	

     Charging
     Pushing/
     Discharging
Ul
-e-
     Quenching
      Coking
     Pollutants
Participates, SO ,
hydrocarbons, CO, NO
& ammonia
Parciculates, hydro-
carbons, ammonia & CO
Coke breeze,
participates, organics
Participates, hydro-
carbons, CO, ammonia
& NO
    Control Technology

Staged/charging (with evacuation of oven
gas to collecting main)
Larry-mounted scrubbers
Fixed duct secondary collectors with gas
cleaning systems (e.g., bag house)
Closed charging systems (tested in PDU
scale only)

Bench-mounted self contained hoods
with gas cleaning systems
Coke car - mounted hoods
Fixed duct hoods with gaa cleaning systems
Spray systems
Coke-side enclosures (sheda) with gas
cleaning systems

Quench tower (containing internal baffles)
Dry quenching
Closed quenching

Mechanical/Magnetic lid lifters
Electrical eye synchronization
Oven and door maintenance
Oven/battery sheds
    Relative
Control Efficiency*

       High

       High
       High

       High
       High

       High
       High
       Med.
       Med.
       Med.
       High
       High

       Unknown
       Unknown
       Low
       High
  Coal Conversion
   Applicability

Not applicable

Scrubbers applicable
Gas cleaning system applicable

Possibly applicable
Possibly applicable

Gas cleaning system applicable
Gas cleaning system applicable
Applicable
Applicable
Possibly applicable
Possibly applicable
Applicable

Possibly applicable
Possibly applicable
Applicable
Applicable
      *High - 90+ %
       Medium - 60-80%
       Low -  60%  or less

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Staged Charging—
     A slight negative pressure is maintained on the ovens to draw gases from
the space above the charged coal into a raw gas collecting main.  This practice
is call "charging on the main."  This negative pressure is provided by a
steam jet aspiration system.  While the aspirator performs its task, air is
drawn into the oven through the charging holes and leveler door.  Since air is
undesirable when introduced to the gas recovery equipment, the time required
for charging is kept to a minimum.
     Staged charging also known as "smokeless charging", besides utilizing a
steam jet aspirator, incorporates other novel control approaches.  The larry
car is sealed, air conditioned, and capable of mechanically  (magnetic lifter)
opening the lids.  The coal-containing hopper is lowered over the open oven
port as in other systems, but when charging is complete a plug of coal is left
in the hopper before the lid is replaced.  The charging is done sequentially,
filling one side of the oven first then working across to the other side.  The
advantage of this procedure is the elimination of the sudden burst of emissions
from the simultaneous charging of all oven ports.  The Clairton Works of
United States Steel (U.S.S) was one of the first plants to achieve effective
stage charging through personnel training, observation and monitoring.  During
the period between 1973 and 1977, U.S.S was able to reduce the charging time
from 50 seconds down to 6 seconds for equivalent opacity (visible emissions)
greater than or equal to 20 percent.  This represented an overall reduction of
almost 90 percent of the fugitive emissions attributed to charging coke ovens.
     In 1973, C.F. & I Steel Co, Pueblo, Colorado initiated sequential (staged)
charge techniques which achieved a reduction in visible emissions (greater
than 40% equivalent opacity) from 85 seconds per charge to 27 seconds per
charge.  Additional techniques they employed, such as modification of steam
aspiration nozzles and installation and maintenance of hydraulically operated
mechanical gooseneck cleaners, have currently reduced the opacity of charging
emissions down to 5.8 seconds per charge.  This application also represents a
greater than 90 percent reduction in visible emissions during the charging
operation of a coke oven.
                                    -155-

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     Since staged charging consists of special mechanisms and procedures of
coal feeding to the ovens, these techniques do not appear to be applicable to
coal conversion systems.  Each coal conversion system has its own coal feed/
condition which is unique to the given system.
Gas Scrubbers—
     Gas scrubbers on larry cars were first introduced in Germany and brought
to the U.S. in the late 1960's when tall ovens became popular.  In principle,
all scrubber cars operate in the same manner.  The coal is discharged from the
larry car into the oven through a spout and the evolved gases are collected in
an annular space around the spout, ignited and cleaned before being discharged
to the atmosphere.  Wet scrubbers, installed on the larry car, demonstrated a
control efficiency for charging emissions by greater than 95 percent for
particulates.
     The scrubber system associated with this control technology should be
applicable to coal conversion systems.  However, the capturing devices (e.g.,
larry car with concentric feed spout and exhaust system), are not applicable.
Fixed-Duct Secondary Collectors—
     More recently, the Japanese have installed a fixed-duct, secondary col-
lector and gas cleaning system which are utilized in conjunction with larry
car wet scrubbers.  Connection ports to a stationary main are provided at each
oven to direct the larry car scrubber exhaust to a fixed scrubber and fan for
secondary emission control and exhaust to the atmosphere.
Closed-Charging Systems—
     The closed-charging system, also known as "pipeline charging," reduces
most of the emissions during charging by employing a completely enclosed
charging operation.  The coal is first crushed, then it is preheated to 500 F
to remove all of the moisture.  The dried coal is then stored in a charging
bin which is pressurized prior to charging.  Afterwards, the coal is introduced
into a pipeline which follows the length of a coke oven battery with pipes
connecting to each oven along the run on the battery.  The pressure in the bin
is sufficient to start the coal in motion and its movement is continued by a
series of strategically located jets that supply steam at supersonic velocities.
These jets permit both upward and forward motion of coal through the pipe.  As
the coal loses momentum and starts to fall to the bottom of the pipe, another
                                     -156-

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set of steam jets is activated and prevents the disentraintnent of the coal.
The coal is then directed in the oven which is prepared for charging.  Coal
can be charged at a rate of 2.5 tons per minute.  Since it is partially
fluidized, it tends to spread itself evenly throughout the oven obviating the
need for a leveling bar.  The theoretical control efficiency for this prototype
system approaches 100 percent.  However, in practice it has been found that
emissions evolve from the charging hole lids and the coke oven doors due to
the high pressure in the ovens.  Closed-charging systems, similar to the type
described above, are being used or developed for some coal conversion systems.

Pushing or Discharging Emission Control
     After the coal has been coked, it must be pushed from the oven and
transported to a quenching station.  The pusher is a combination of three
machines:  a pusher, a leveler and a door extractor.  It is designed to operate
on an independent track which runs parallel to and independent of the battery.
The coke receiving quench car operates on tracks at grade; also, independent
of the battery and in the opposite side of the coke oven from the pusher
machine.  All pushing or discharging emission control systems operate in
conjunction with the quench car.
     The performance of the pushing/discharging emission control system is
 extremely sensitive to the condition of the coke when it is pushed.  If two
important coking cycle variables, oven residence time and homogeneous oven
temperature, are not carefully maintained throughout the cycle "green coke"
may form.  If the coke is pushed in this undesirable condition, no presently
developed pushing control system can effectively capture and control the
excessive emissions associated with it.  The various system control efficiencies,
where given, do not presume green coke pushes.
     The pushing of the incandescent coke from the oven into the quench car
results in emission of hot coke particles and tars, as well as gases as it
leaves the oven and is dumped into the quench car.  Various systems being
developed for pushing emission controls are discussed below.
Bench-Mounted Self-Contained Hoods—
     Bench-mounted, self-contained hood systems include designs incorporating
mobile hoods, ducts, scrubbers or other high-efficiency control devices, and
                                     -157-

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fans that are mounted on a separate vehicle which traverses the length of the
battery on the bench with the coke guide.  Utilization of this approach has
been confined to West Germany.  A mobile version of this gas cleaning system
could have application for the coal conversion systems.
Coke Quench Car-Mounted Hoods—
     Coke quench car-mounted hood systems include a family of designs employing
hoods, ductwork, scrubbers, and fans which are mounted on and travel with, the
coke quench car.
     Many recent commercial designs of this type of control system have been
developed jointly by industry and the EPA.  Five different systems are operating
or are proposed to go into operation include:  Koppers for its own Erie, PA
plant and for Bethlehem Steel's coke plants in Johnstown, PA; U.S.S for its
Gary Works No. 2 Battery; Dravo for Armco Steel's new battery at Middletown,
Ohio; Granite City Steel, Div. of National Steel Corp., and McKee Otto for the
Granite City plant; and Chemico Air Pollution Control Co., Div. of Envirotech
Corp. for Jones and Laughlin Steel Co.'s Pittsburgh Works.  Also, National
Steel Corp., for its Brown's Island coke plant, has been operating a closed
quench car system for several years.  National has started up its system on a
coke battery at Armco Steel in Hamilton, Ohio and recently installed a system
at the C.F.&I coke plant in Pueblo, Colorado.
     The principal features of these designs include a modified door machine
with coke guide housing attached, a mechanism to permit the discharge of hot
coke, a control car containing gas cleaning equipment, and the operator's cab
and quench car with fixed hood.  The gas cleaning systems will be applicable
to coal conversion systems but the other special design features may not be
suitable for coal conversion applications.
Fixed-Duct Hoods—
     Fixed-duct hood systems provide a stationary duct, fan, and scrubbing
system with duct ports for connecting to a mobile hood arrangement over the
pushing operation.
     A system of this type commenced operation at the Minister Stein coke
plant in Germany in early 1975.  The system was designed and constructed by
Hartung, Kuhn and Co. and formed the basis of the design of the Allied
                                     -158-

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Chemical Co. Ashland, Kentucky plant system.  This system was furnished by
Dravo-Still, in conjunction with Hartung, Kuhn and Co.  The Allied Ashland
system began operation in the United States in December, 1978.
     The Dravo-Still system is a combined mobile and land-based system.  The
mobile section is made up of two parts.  The first part consists of a main
quench car hood, a tripper car, a regenerator heat exchanger, a short section
of main hood ductwork and a short section of auxiliary ductwork which connects
to the coke guide hood ductwork.  The second part is the hood and ductwork
located on the door machine above and along the sides of the coke guide.  The
duct from this part is connected to the primary ductwork by a telescoping duct
section mounted in the door machine.  The main feature of this system consists
of the gas transition (tripper) car which travel along the top of a stationary
duct placed along side the quench track. The duct possesses a continuous
opening along the top which is internally braced and covered with grating to
provide support for the belt which seals the opening.  The tripper car lifts
the belt over the duct inlet section between the tripper rolls and covers the
duct opening to convey the gases from the mobile hooding into the stationary
duct.
     When the system is in operation, emissions are collected simultaneously
above the coke guide and quench car and are carried through the stationary
duct to the particulate collection equipment, which may be a scrubber, fabric
filter or wet electrostatic precipitator.  Although no test data are available,
preliminary tests have shown favorable results.  A similar system is operating
successfully at Dominion Foundries & Steel Ltd.  (DOFASCO),  Hamilton, Ontario
in Canada.  Three additional systems are under construction which will utilize
a fabric filter particulate collection device.  These type systems, also known
as "smokeless pushing" have been estimated to achieve 95 percent collection
efficiency.  The gas cleaning system associated with this control technology
will be applicable to the coal conversion systems.  However the fixed-duct and
mobile hood arrangement will probably not be suitable.

Spray Systems—
     Water spray or fogging systems can be employed to minimize pushing
emissions.  Such sprays can be located at the coke guide or the coke quench
car.  Where sprays alone  can be partially effective, they are more often used

                                      -159-

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to enhance the effectiveness of hood and scrubber systems.  Electrical safety,
ice formation, and water removal are necessary concerns with this type of
system.  Spray systems will have applications in coal conversion systems in
many operations, e.g., dust control from coal storage piles.
Coke-Side Enclosures —
     Coke-side enclosures or sheds entail nearly complete enclosure of the
coke side of the battery instead of local hooding.  Numerous design advantages
are cited, which are simplicity of design and operation, ease of retrofitting
to existing batteries, and the ability to collect emissions from leaking
doors.  Since the shed encloses the coke side portion of the battery, some of
the coke oven operators working in this area might be exposed to higher
emissions.  These emissions could subject the workers to additional health
hazards .
     Enclosures, sheds and hood systems should have applications in coal con-
version systems for fugitive emissions control.
Quenching EfrHssion Control
     Quenching (wet) in most modern plants is accomplished by receiving the
charge of hot coke from the ovens in the quenching car, which is conducted to
the quenching station or tower by a locomotive, where the coke is quenched by
water.
Quench Tower With Internal Baffles —
     The most common methods of reducing p articulates and gaseous emissions
which rise with the steam evolved from quenching are to trap the pollutants as
they ascend through the quench tower, or to reduce the amount of steam generated.
Both of these goals are achievable to a limited extent through use of internal
baffles, also called "mist suppressors".  They are simply different arrangements
of wooden slats which are inclined and perpendicular to the path of the rising
steam in the tower.  As the steam passes through the wooden configurations,
particulates tend to become trapped on the wood.  Also, some of the steam
recondenses on contact with the cooler surface of the baffle.
     Recently, the Dominion Foundries & Steel Ltd. at Hamilton, Ontario had
tests conducted on their quench tower.  The results of the testa which varied
quench tower, quench water and mist eliminator conditions .gave an average of
0.245 pound of p articulate matter per ton of coal charged.  Also it was
                                     -160-

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determined that, upon using recycle water for quenching, the emission rate was
0.21 pound per ton of coal charged; and using once-through bay water the
average was 0.234 pounds per ton of coal charged.  Also, it was found that
increasing the baffle angle from 20  to 40  to 30  to 60  had the greatest
effect on increasing the collection efficiency.  The overall control efficiency
was found to be 60 percent for particles greater than 100 microns.  Test
efficiencies have been reported by others as high as 80 percent.
     Also, in tests conducted at the Lorain Works plant of U.S.S aside from
particulate matter, organic compounds were also detected.  It was found that
10 to 100 pounds per quench of organics, with the bulk identified as aromatics,
were being emitted to the atmosphere.  These organics are associated with the
oil used for controlling the bulk density of the coal charged to the ovens.
Dry Quenching—
     Dry quenching involves the use of an essentially inert gas as the heat
transfer medium.  Heat transfer from the coke to the inert gases is accomplished
by direct contact of the gases with the coke.  The gases are then conducted
through a dust collector to a waste-heat boiler or other type of heat exchanger
device.
     Plants employing this technique have been operating since  1917, mostly
located at town gas plants with the largest handling 1500 TPD.  The only
existing plant is in Homecourt, France, which cools about 1500  TPD of blast
furnace coke.  The USSR has developed  their own dry quench technology which  it
has applied to 50 large, new blast furnace coke making  facilities, and requires
all new and retrofit facilities.
     Basically, the system operates in the following manner:  incandescent
coke is carried to the dry-quenching station in a  transfer car, which is
raised to the top of the dry-quenching bunker.  The hot coke is dumped into
the bunker, after which the charging hole then closes and the empty car is
returned to the track for another load.  As the coke descends the bunker
cooling chamber, it is cooled by a counter-current flow of circulating gas.
Quench time in the chamber ranges between 2 and 4  hours.  At the  completion  of
this cooling cycle, the coke, which has cooled to  between 400 and 500 F,  is
discharged from the bunker through a measuring chamber  and double gate
arrangement.  Except for the periodic  introduction of hot coke  and a small
quantity of air, dry quenching  is a closed cycle operation.
                                     -161-

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     Two such systems are presently being marketed by American-Biro Company
and Patent Management, Inc.  Also, Japanese companies have signed licensing
agreements with the USSR and are interested in the potential U.S. market.  The
Japanese have introduced some modifications to the basic USSR system to achieve
greater reliability and improved control efficiency.

Closed Quenching—
     There are several types of closed quenching operations which can signifi-
cantly reduce quenching emissions.  One method of approach is to feed hot coke
at a controlled rate onto a moving, stainless steel, linear grating in an
enclosed operation.  As the coke moves along the grating, water is sprayed on
it, eventually cooling the coke below combustion temperatures.  At the end of
the grating, it is then dumped into another container beneath the roof of a
kiln.  The steam generated is passed through a series of internal baffles
which removes most of the particulates.  Another advantage of this system,
besides controlling emissions, is that a higher quality coke is obtained from
the uniform swift cooling.
     Closed quenching will be applicable to analogous operations in coal
conversion systems, since most of these systems are normally closed and
pressurized systems.

Improvements in Operating Procedures and Maintenance
     Relatively minor improvements in operating procedures and more subtle
approaches to maintenance requirements can significantly reduce emissions from
coke oven leaks and openings.  These procedures an  equipment associated with
them would be of use in the coal conversion industry.
Magnetic Lid Lifters—
     Until recently many coke plants removed and replaced charging hole lids
on top of the coke ovens during charging manually.  This method is being
replaced by automatic magnetic type lid lifters being installed on the larry
cars.
Electric Eye Synchronization—
     Electric eyes are being installed on many coke ovens to verify the
positioning of the larry car directly over the oven port prior to charging.
                                    -162-

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Also, they are being used to verify that the door extractor and pushing ram
are correctly positioned.  They can also be used to properly realign the doors
after the push.
Oven and Door Maintenance—
     During the coking cycle, excessive emissions may result from poor oven
maintenance and from improperly maintained or designed oven doors.  Emissions
can be significantly reduced by routine scheduling of repair and/or replacement
of parts.
     An obvious location where significant emissions might occur is the coke
oven door.  In the past, luted doors were used which required almost continuous
luting by workers to prevent emissions.  Today, most oven doors are the self-
sealing knife edge type.  These doors when fitted with appropriate jambs,
seals and backstays have demonstrated to be very effective in controlling
emissions due to door leakage.
     U.S.S has found that through  good maintenance and operating procedures,
they have achieved 98 percent compliance with a 10 percent door leakage regu-
latory requirement.
     Another significant source of emissions is from the ovens themselves.
These emissions tend to increase as  the oven battery ages.  The Jones  and
Laughlin Steel Corp. at its Pittsburgh Works found that by silica dusting and
patching of its ovens, they were able to achieve a reduction in their  coke
oven stack emissions of 68 to 87 percent of greater than 20 percent opacity
for a period of 6 to 18 minutes per  hour.

Recent Control Technology Developments
     The Steel Company of Canada  (Stelco), Hilton Works in Hamilton, Ontario
is operating a fugitive emission  control system which  employs  a shed over the
entire coke battery.  The shed  is  capable  of  capturing 600,000 ACFM of air
which is then exhausted to 9 wet-walled electrostatic  precipitators. The major
drawbacks associated with this  type  of  control system  is that  the hood exhaust
runs constantly and that  it  tends  to corral emissions  from  the general oven
leaks and openings which  could  adversely affect  the battery operators'  health.
The  capital equipment cost for  this  system is estimated at  $7.2 million.
                                      -163-

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     Philadelphia Coke Co., Inc., after consideration of the three basic
designs:  fixed-duct hood system, coke car-mounted hood system and coke-side
enclosures (general descriptions of which were given earlier) favors the
fixed-duct hood system for fugitive emission control    .  This system is
favored because of the operational and noise problems associated with the coke
car-mounted system and the exposure of employees to heavy dust concentrations
which would occur within the coke-side enclosure.
     Based on blast furnace plants, the estimated cost of the system is in the
4 to 5 million dollar range.  Since Philadelphia Coke is a foundry coke plant,
which does not experience the dirty pushes (green coke) and high sulfur
concentrations in the gas, it is expected the system for foundry coke plants
could be installed for about one-half of the above stated costs.
                                     -164-

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                                    SECTION 8
                    THE HEALTH EFFECTS OF COKE OVEN EMISSIONS

HEALTH EFFECTS/IMPLICATIONS
     To briefly assess the health effects attributed to coke oven emissions, a
literature review primarily of recent information released in draft forms by
the U.S. EPA - Office of Research and Development was utilized.
     The purpose of the review was to provide basic information regarding the
potential health effects on coke oven workers and on the general population
who are exposed to coke oven emissions.

Chemical Composition of Coke Oven Emissions and their Health Implications
     Coke oven emissions consist of all of the constituents of bituminous coal
which are released into the atmosphere during the process of coal carbonization.
Table 8-1 shows a partial list of the constituents of the coke oven emissions.
     A number of these constituents are suspected to be human carcinogens.
The toxicity of coke oven emissions may also be associated with respiratory
irritation, cocarcinogenesis, tumor promotion and other toxic effects.  Table
8-2 summarizes some noncarcinogenic toxic effects.

Particle Size and^ Its Jtealth Effects
     In addition to chemical composition, the form in which the various
constituents are released into the atmosphere (e.g., aerosols, gases), and the
size and density of the particulate matter with which they are associated
determine their effects on human health.  Most of the particles emitted are in
the respirable range, which means that they can penetrate into the lungs
beyond the normal respiratory defense mechanisms.  Particles ranging from 0.1
to 2 microns in diameter are the optimum size for such penetration, and there-
fore, are the most biologically significant.  After entering the respiratory
tract, they are largely retained in the trachea, bronchi, and alevoli.
                                     -165-

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      TABLE 8-1.   PARTIAL LIST  OF CONSTITUENTS OF COKE OVEN EMISSIONS
                  (SOURCE:   BIBLIOGRAPHY 62)
 Anthanthrene
 Anthracene
 Benzindene
 Benz (a)  anthracene"  ,
 Benzo (b)  fluoranthene
 Benzo (ghi) fluoranthene"
 Benzo (j)  fluoranthene
 Benzo (k)  fluoranthene
 Benzofluorene
 Benzo (a)  fluorene
 Benzo (b)  fluorene
 Benzo (c)  fluorene
 Benzophenanthrene
 Benzo (ghi) perylene
 Benzo (a)  pyreneb
 Benzo (e)  pyrene^3
 Benzoquinoline
 Chrysene
 Coronene
 Dibenz (ah) anthracene1'
 Dibenzo (ah) pyrene'5
 Dihydro anthracene
 Dihydrobenzo (a) fluorene
 Dlhydrobenzo (b) fluorene
 Dlhydrobenzo (c) fluorene
 Dihydrobenz (a) anthracene
 Dihydrochrysene
 D ihydrofluoranthene
 Dlhydrofluorene
 Dlhydromethylbenz (a)
 anthracene
 D ihydrome thlybe nzo
 (k  and b) fluoranthenes
 DIhydromethylbenzo
 (a  and e) pyrenes
 Dihydromethylchrysene
                   fluoranthene
D ihydrome thy Itr iphenylene
D ihydrophenanthrene
D ihydropyrene
Dihydrotr iphenylene
Dimethylbenzo  (b)  fluoranthene
Dime thylbenzo  (k)
Dimethylbenzo  (a)  pyrene
Dime thyIchrysene
D imethyItriphenylene
E thylanthracene
E thylphenanthrene
Fluoranthene
Fluorene
Indeno (1,2,3-cd)  pyrene
Me thylanthracene
Methylbenz  (a) anthracene
Me thylbenzo (a) pyrene
Me thylbenzo (ghi)  perylene
Me thyIchrysene
Me thyIfluoranthene
Me thyIflucrene
Me thylphenanthrene
Ma-thylpyrene
Me thy Itr iphenylene
Octahydroanthracene
Octahydrofluoranthene
0 ctahydrophenan threne
Octahydropyrene
Perylene
Phenanthrene

o-Phenylenepyrene

Pyrene

Triphenylene
POLYNUCLEAR AZA-HETEROCYLIC
 COMPOUNDS3

Acridine
Benz (c) acridine
TRACE ELEMENTS1
Arsenic
Beryllium
                                 -166-

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                             TABIE  8-1.   (continued)
      Dibenz (a,h) acridine
      Dibenz (a,j) acridine

      AROMATIC AMINESb

      a-Naphthylamine
      3 -Naphthy lamine

      OTHER AROMATIC COMPOUNDS

      Benzene
      Phenol0
      Toluened
      Xylened
Cadmitim
Chromium
Cobalt
Iron
Lead
Nickel
Selenium

OTHER GASES

Ammonia0
Carbon disul£idec
Carbon monoxide0
Hydrogen cyanidec
Hydrogen sulfide
Methane0
Nitric oxided
Sulfur dioxide0
a Lao et al (1975), except as noted,

b
  Kornreich (1976).


C Smith (1971) .

d
  White (1975).
                                      -167-

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             TABLE 8-2,   SOME TOXIC  CONSTITUENTS  OF  COKE  OVEN  EMISSIONS AND  SOME  OF  THEIR TOXIC PROPERTIES
                                    (SOURCE -  BIBLIOGRAPHY 62)
        Constituent
ON
r
        Acridine
        Anthracene
        Arsenic
        Benzene
Suggested Threshold
 Limit Value (TLV)
                                                                 Potential  Health  Effect
Acetone
Ammonia
1,000 ppm
2,400 mg/m3
25 ppm
18 mg/m3
At 300 ppm —
500 ppm —
1,000 ppm —
1 ppm —
20 ppm —
Slight irritation
Still tolerated
Chronic irritation of
respiratory tract, dizziness
Odor detectable
Discomfort in uninured workers,
0.25 mg/m3
1.0 ppm/3,0  mg/m'
                                                                    complaints
                                                        100  ppm —  Irritation of  respiratory
                                                                    tract  and conjuctivae
                                          Powerful irritant:
                                          Photosensitizer
                                          Causes dermatitis
                              eyes
          Irritant:   eyes,  skin,
           respiratory tract
          Photosensitizer

          Contact dermatitis and
           sensitization
          Conjunctivitis
          Ulceration and perforation
           of nasal  septum
          Narcotic effects
          Severe exposures cause  bone marrow
           and blood changes
          Myelotoxic
25 ppm — Exposure for 12 years;  very little
          intoxication reported
          Blood changes reported
          Deaths reported
                                                         60 ppm
                                                    100-200 ppm

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                                       TABLE 8-2  (continued)
Constituent
Beryllium


Cadmium dust
Chromium

Cobalt
Formaldehyde
Hydrogen
  Cyanide
 Suggested Threshold
  Limit Value (TLV)
 0.002 mg/m3

 0.05 mg/m3
 0.5 mg/m

 0.01 mg/m3
 2 ppm
10 ppm
                                                         Potential Health Effect
                Dermatitis,  tracheobronchitis
  100 yg-../m3 — pneumonitis
                Distinctive, nonhypertropic emphy-
                sema, with or without damage to
                renal tubes; anemia,  eosinophilia,
                anosmia,  chronic rhinitus, yellow
                ring on teeth, bone changes
  2-15 mg/rn^ — Anosmia,  proteinuria (low molecular
                 weight)  pulmonary emphysema, yellow
                 ring on  teeth, eosinphilia, anemia

                Dermatitis (salt)

                Pulmonary involvement,chronic inter-
                stitial pneumonitis
  1-2  mg/m^ — Serious and  occasionally fatal
                results,  hypersensitivity, allergic
                dermatitis
  1-2 ppm


    6 ppm

20-40 ppm
Irritant:  eyes, respiratory tract,
 skin
Itching eyes, dry and sore throat,
 disturbed sleep, unusual thirst on
 awakening
Eye irritation

Slight intoxication, variety of
 neurological symptoms

-------
                                     TABLE ft-2 (continued)
Constituent
Suggested Threshold
 Limit Value (TLV)
                                                          Potential Health Effect
Hydrogen
 sulflde
 10 ppm
(15 mg/m3)
500-1,000  ppm —



   50-500  ppm —

  250-600  ppm —


    5-100  ppm —
Lead
 0.15 mg/m3
Nickel
Pyridine
    1 mg/m3



    5 ppm
                 Acts primarily as systematic
                 poison causing unconsciousness
                 and death through respiratory
                 paralysis.
                 Acts primarily as a respiratory
                  irritant.
                 Prolonged exposure may lead to
                 pulmonary edema and bronchial
                 pneumonia.
                 Associated with eye irritation.

                 Nerve function disorders,  inabi-
                  lity to sleep, fatigue,
                  constipation;
                 Long-term exposure: anemia, colic,
                  neuritis, headaches,  loss of appe-
                  tite, weakness, double vision:
                 Organic lead:   mental  disturbances,
                  inability to  sleep, general an-
                  xiety, delerium - acute.

                 Increase in incidence  of  nasal,
                  sinus, and lung cancer in workers
                  in nickel refineries
0.83-2.46 ml  — Was toxic in human therapy with one
                 death from liver and kidney damage.
                 Central nervous system affected.
                 Stimulates bone marrow to production
                 of blood platelets .
                 Vapor - irritating to  mucous surfaces,
   15-330 ppm — Nausea, headache,  insomnia and ner-
                  vousness, low back or abdominal
                  discomfort.

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                                          TABLE 8-2 (continued)
       Constituent
Suggested Threshold
 Limit Value (TLV)
        Selenium
       Sulfur dioxide
i
M
-J
       Toluene
       Xylene
0.2 mg/m3
                                               0.007-0.05 mg/m3

                                                  0.2-0.4 mg/m3
  5 ppm
 13 mg/m
100 ppm
375 mg/m3
0.1 mg/m3
                 Intense irritation of eyes, nose,
                 and throat, headache.  Severe
                 exposure:  bronchial spasma, asphy-
                 xiation, chills, fever, bronchitis.

                 Headache, traecheobronchitis,
                 conjunctivitis.
                 Garlic odor of breath, skin rashes,
                 indigestion, metallic taste.

                 Irritation of the mucous membranes,
                 coughing, eye irritation, increased
                 pulmonary flow resistance; adverse
                 symptoms appear at levels between
                 5 and 10 ppm.
100-1,100 ppm — Enlargement of liver, macrocytosis,
                  moderate decrease in erythrocyte
                  count and absolute lymphocystosis.
                 Headache, nausea, lassitude.
                 Impairment of coordination, momen-
                  tary loss of memory, anorexia.
500-1,500 ppm — Palpitation, extreme weakness,
                  pronounced loss of coordination
                  and impairment of reaction time;
                  red cell decrease in 2 cases,
                  aplastic anemia (possible benzene
                  impurity);
      200 ppm — Slight but definite changes in  mus-
                  cular coordination; 7 hours exposure
                  to 200 ppm cause prolongation of
                  reaction time, decreases in pulse
                  and systolic blood pressure.
                 Acute oral and skin irritation, sensi-
                  tization, gastrointestinal irritant.
                                                        200 ppm
                                                    200-500 ppm

-------
Particles larger than 2.0 microns are trapped by the mucous membranes and do
not enter the lungs.  Particles smaller than 0.1 micron are retained in the
tracheobronchial tree but elution does not occur.  Particles smaller than 0.04
micron do not come out of suspension in the inhaled air and are exhaled.  The
trapped particles in the mucus that are not exhaled and that also do not enter
the lung are either swallowed or spit out.  Table 8-3 gives the range of
particle sizes found in coke oven emissions.

jfenergjlsms
     Some researchers have shown the importance of synergism of pollutants in
air, two of the most common being sulfur dioxide (SO.) and benzo-a-pyrene
(BAP).  It has been postulated that SO- synergism shows ciliary action, and
therefore increases BAP retention and/or causes chronic injury; following
injury, the resultant regenerating cells may be more susceptible to the BAP.
These effects have also been demonstrated between carcinogenic chemicals  (e.g.
BAP) and particulate matter (e.g., iron oxide, carbon).
     The indication in laboratory experiments that different components of
coke oven emissions interact synergistically lends support to the view that
the toxic potential of the complex mixture — coke oven emissions — cannot be
related to the potential of a single compound.

BASIS OF SAMPLING AND MEASUREMENTS
     Because of the effort and complexity that would be required in charac-
terizing all of the constituents of coke oven emissions, various surrogate
measures have been used in the past.  These usually are of three types:
          Total Suspended Particulates (TSP)
          Benzene Soluble Organics     (BSO)
          Benzo (A) Pyrene             (BAP)
     TSP is generally considered not to be a specific enough measure for
assessing total occupational health effects.  Previous occupational and
general atmospheric studies provide some justification for using a surrogate
measure rather than trying to identify and control each of the polynuclear
aromatic (PNA) compounds emitted by coke ovens.
     Table 8-4 summarizes the exposures of coke oven workers to coke oven
emissions (benzene soluble fraction of total particulates).

                                     -172-

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                              TABLE 8-3.  PARTICLE SIZE RANGE AND BIOLOGICAL
                                          SIGNIFICANCE OF COKE OVEN EMISSIONS
                                          (SOURCE - BIBLIOGRAPHY 62)
Sizea
Site
Process
                                                                    Reference
Biological
significance
0.1-iym (tarry   Retort house
 droplets)

1 ym  and up (dust) Retort housa

l.Syro             Topside coke oven

l.Syni             Topside coke oven

2.9yro             Topside coke oven

iym-1.27 mm      Coke plant

5ym.-1.27 mm      Coke plant
                                       General atmosphere
                                         (shift change)
                                       During coking

                                       Charging

                                       Quenching
                                     Lawther (1964)


                                     Lawther (1964)

                                     White,  L.D.  et  alb

                                     White,  L.D.  et  alb

                                     White,  L.D.  et  alb

                                     Fullerton,  R.W. (1967)

                                     Masek,  V.  (1970, 1970a)
                                             Particles in the
                                             0.1-2.0 y range
                                             are respirable
                                             and largely re-
                                             tained in the
                                             trachea, bronchi,
                                             and alveoli.
                                             Particles > 2.Oy
                                             are trapped in the
                                             mucous membranes.
                                             Particles -CO.ly
                                             are retained but
                                             elution does not
                                             take place.  Par-
                                             ticles <0.04y  are
                                             exhaled (Falk and
                                             Kotin, 1961).
a For respirable particles, the rate of elution of PAH increases with the size of the particle to which the
    PAH is absorbed.
  No date.

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 TABLE 8-4.  SUMMARY OF EXPOSURES OF COKE OVEN WORKERS TO COKE OVEN EMISSIONS
             (BENZENE SOLUBLE FRACTION OF TOTAL PARTICULATES)

                        [SOURCE - BIBLIOGRAPHY 32]
        A Summary of Separate Air Sampling Studies by AISI Member
    Companies and Pennsylvania Department of Environmental Resources.

Operator
(source                      No.  of         Range*             Average**
of info.)                    Samples        (mg/m3)             (mg/m3)

Larry car operator
       AISI                    106          0.78 -  6.4          2.2
       PA                       39          0.28 -  8.8          3.1

Lidman
       AISI                    140          1.0  -  5.6          2.6
       PA                       61          0.42 - 18.           3.2

Door Machine Operator
       AISI                     85          0.31 -  5.1          1.2
       PA                       25          0.04 -  6.5          2.1

Door Cleaner/Luterman

       AISI                    172          0.31 -  3.2          1.1

Patcher
       AISI                     10          0.71 -  1.3          0.99

Eeater
       AISI                     60          0.12 -  2.4          0.57
       PA                       39          N.D. -  3.0          1.1

Quench Car Operator
       AISI                     70          0.05 -  1.2          0.44
       PA                       23          N.D. -  7.0          0.94

Pusher Operator
       AISI                     78          0.15 -  0.82         0.40
       PA                       23          N.D. -  0.93         0.39


*   AISI DATA is a range of the mean coke oven emission concentration
    reported for each job description by each coke plant  studied.

**  AISI DATA is the average of mean concentration for each coke plant
    studied.

    N.D. - None Detected.
                                   -174-

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     Table 8-5 shows a comparison of BAP concentrations measured at coke oven
batteries and at other selected sites.
     The National Air Sampling Network (NASN) routinely monitors suspended
particulate levels in urban and non-urban areas.  BAP and BSO are monitored
for 40 locations that include cities with and without coke ovens and rural
                                                                     3
areas (See Table 8-6).  The BAP concentrations are generally 0.1 ng/M  for
rural locations.  Most urban locations without coke ovens have average
                                  3                          3
concentrations of less than 1 ng/M  (the average is 0.38 ng/M ); however,
areas with coke ovens generally have average concentrations in excess of
      3                          3
1 ng/M  (the average is 1.21 ng/M ).

EPIDEMIOLOGICAL STUDY RESULTS
     Epidemiological evidence of greater increases in disease rates among
workers exposed to the higher-temperature processes suggests that the higher
the temperature of carbonization, the higher the proportion of toxic compounds
released.  Table 8-7 shows the excess of reported lung cancer among workers
for various carbonizing chamber temperature ranges.
     Epidemiological studies in different countries have demonstrated that
workers exposed to the products of  combustion and distillation of bituminous
coal experience an increased incidence of cancer of several sites  (lung,
pancreas, kidney, bladder, skin).   Table 8-8 is a summary of relative risks of
death from cancer among coke oven workers.
     There are no epidemiological studies of the cancer exposure of populations
living near coke ovens or gas works.  As a basis for estimating the magnitude
of the excess cancer risk, the summary was extrapolated from cancer mortality
data on coke oven workers and other workers in the steel industry.
     Because the extensive epidemiological evidence describes adverse health
effects experienced by an industrial work force exposed to "coke oven emissions"
(i.e., the total, complex mixture,  often characterized as the benzene-soluble
fraction of total particulate matter), the effects of the constituents such as
BAP and BSO acting separately or in various combinations need not be delineated
for human experience.  It is, therefore, essential that the assessment of
health effects be applied to "coke  oven emissions" as an entity and not  to any
particular component.
                                      -175-

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TABLE 8-5.  COMPARISON OF BENZO  (a) PYRENE CONCENTRATIONS MEASURED AT COKE
            OVEN BATTERIES AND AT OTHER SELECTED  SITES
                           (BIBLIOGRAPHY 62)
                                        Concentration,  (yg/m )
   Country
Soviet Union
Soviet Union
Japan
Norway
Czechoslovakia
Czechoslovakia
Czechoslovakia
Czechoslovakia
England
USA
USA
USA
USA
USA
USA
USA
Switzerland
USSR
England
England
USA
USA
Year
1962
1968
1968
1959
1966
1967
1968
1974
1965
1974
1960
1974
1974
1968
1961
1961
1961
1966
1965
1965
1959
1966
Top- Side
1.27
0.05

2
1.1
3.6
10.7
0.1
3
1.2
8.3
0
0.18
95
6.1
14
640
13.7
(0.02)
2,330
(0.022)
(0.0185)
27.4
7.38

7.3
94.8
32.2
12.7
13.1
216
15.9
51
225.9
36.3
78

22


(3.84)'
(6.5)
(9.55)
(5.78)
      Side

0.08 - 0.27  (0.17)
1.5  - 3.14
          0.6  - 3.4
0.3  - 1.98  (1.0)
               Contrast
          Cigarette smoke
          Auto exhaust
          Roof tarring
          Roof tarring
          Aluminum Plant
          Urban - London
          Maximum found in
          fumes emitted from
          coke ovens
          Birmingham
          Birmingham
  Mean.
 Source:  White, et al.
                                     -176-

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                     TABLE 8-6.   AMBIENT BAP AND BSO DATA
                                  (SOURCE - BIBLIOGRAPHY 64)
 Pollutant
BAP (ng/m3)
  1975 Data
  BSO (yg/ta )
  1971-72 data
Statistic
Average
Sample Size
Range
Average
Sample size
Range
 Cities
 with
 Coke
 Ovens
 1.21
21.00
 0.3 - 4.7
 4.21
25.00
 2.1 - 7.3
Cities
without
Coke
Ovens
 0.38
13.00
 0.03 - 0.9
 3.75
12.00
 1.9  - 5.6
Rural Areas

  3.00
<0.10
  0.95
  2.00
  0.8 - 1.1
              TABLE 8-7.
      Carbonizing
        Chamber
Vertical retorts
Horizontal retorts
Coke ovens
Japanese gas generators
        TEMPERATURE RANGE OF CARBONIZING CHAMBERS
          AND EXCESS OF LUNG CANCER REPORTED.
             (SOURCE - BIBLIOGRAPHY 62)
          Temperature
           Range,  C
            400 -   500
            900 - 1,100
          1,200 - 1,400
                > 1,500
              Reported Excess of Lung
              Cancer among Workers (%)
                   27 (Doll, 1965)
                   83 (Doll, 1965)
                  255 (Lloyd, 1971)
                  800 (Lloyd, 1971)
                                       -177-

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                                 TABLE 8-8.  SUMMARY OF RELATIVE RISKS OF DEATH FROM CANCER AMONG COKE OVEN WORKERS8

                                                     (SOURCE - BIBLIOGRAPHY 62)


Length of employment
(1953-1970), yr









1
H
00
1
Work area
Total coke oven
Coke oven
Oven topside full-time
Oven topside full-time
Oven aide only
Non-oven
Mo one coke plant area

Distribution
of workers
5+ 10+ 15+

1860 1194 790
993 574 325
150 72 29
290 245 159
553 257 137
836 578 392
31 42 73

Deaths and BR's of death from Deaths and RR's of death
malignant neoplasms respiratory cancer
5+
Obs. RR
166 1.47b
101 1.66b
35 3.70b
26 l.59b
40 1.17
65 1.28
0 d
Deaths and RR's
cancer of digestive
10+ 15+ 5+ lOf
Obs,
136
85
22
31
32
48
3
RR Obs. RR Obs. RR Obs. RR
1.50b 108 1.62b
1.95b 63 2.40b 54 3.02b 44 3.42b
5.12b 12 7.63b 25 9.19b 16 11.79b
1.85b 32 2.73b 12 2.29b 16 3.07b
1.46 19 1.51 17 1.79° 12 1.99b
1.10 39 1.13
d 6 1.34
from
15+
Obs. RR

33 4.l4b
8 15.72b
18 4.72b
7 2.00


of death from
system
among non-

oven workers




5+ 10+






All malignant neoplasms
Large intestine
Pancreas
Other
Obs
of digestive system 28
11
8
9
. RR Obs.
1.58° 23
2.31C 10
3.67b 7
0.83 6
RR
1.53
2.52b
3.75b
0.65

15+
Obs. RR
19,, 1.53
8 2.37°
6 4.29b
5 0.65







^Adapted from Redmond (1976).
bp'0.01,           p < o.Ol

X0'05-           P < 0.05
 less than 5 deaths.

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     Several mortality studies have shown that workers at coke plants are at
an increased risk for dying of chronic bronchitis.  Unlike the risks from
respiratory malignancy, the risk appears to be about the same for coke oven
workers and for non-oven workers employed at the plant.  It indicates that the
risk of the plant workers is greater than two-fold relative to the rate of
mortality from chronic bronchitis in the steelworker population.  Table 8-9
shows the estimated effects of coke oven emissions on U.S. population.  An
affected radius of 15 kilometers (approximately 9 miles) from a coke plant is
considered as the maximum potential exposure population.  The estimate indi-
cates that for the highest 100,000 people exposed there is a 0.2 to 0.6 percent
excess chance of dying of lung cancer.  For the remaining 15 million people,
the excess is about 0.1 percent.  The total number of excess lung cancer
deaths is about 150 cases per year.  These estimates should be regarded as
crude and probably conservative; i.e., on the high side.
     Without any significant coke oven exposure, the lifetime probability of
dying of lung cancer is 3.29 percent.

SUMMARY OF STUDY FINDINGS
          Exposure to coke oven emissions provides an elevated risk for cancer
          of all sites and non-malignant respiratory diseases to coke oven
          workers and an increased risk among lightly exposed workers (non-
          oven workers in coke plant).
          The general population, which includes the young, the old and the
          infirm in the vicinity of a coke oven plant should be considered
          more susceptible than the workers, especially for development of
          chronic bronchitis, since they are generally in poorer health.
          Coke oven emissions contain an array of identified carcinogens,
          irritants, particulate matter, trace elements, and other chemicals.
          The toxic effects observed  in both humans and animals are greater
          than the effects that can be attributed to any individual component.
          Thus "coke oven emissions"  as a whole should be considered  the toxic
          agents.
          There is an exposure difference of about 2 orders of magnitude
          estimated between lightly exposed workers and people living in the
          vicinity of a coke plant.   Since these  lightly exposed workers show

                                     -179-

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an elevated risk for cancer and non-malignant respiratory disease,
it is reasonable to assume that levels up to one-hundreth of those
to which lightly exposed workers are subjected could cause an
increased risk to the general population.
                            -180-

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TABLE 8-9.  ESTIMATED EFFECTS OF COKE OVEN EMISSIONS ON U.S. POPULATION
            UNDER WEIBULL PROBABILITY MODEL WHERE "HIT PARAMETER11 m = 1
            AND ADJUSTMENTS FOR TOTAL POPULATION RATES USED

                            (SOURCE:   BIBLIOGRAPHY  1)
                                                         Given Coke Oven
No. of
Lung Cancer



1
M
00
M
1

X =
Exposure to_
BSO in yg/m
in Air
Background** 3 . 75
4.50
5.50
6.50
7.50
8.50
10.90
Number of
People in
Exposure
Group
-
13,900,000
1,034,000
54,000
7,780
2,420
1,800
Lifetime
Probability of
Lung Cancer
.03286
.03360
.03435
.03519
.03604
.03669
.03890
Increase in
Lung Cancer
Due to Coke
Oven Emissions
-
6.37 x 10"A
1.49 x 10~3
2.33 x 10~3
3,18 x 10"3
4.02 x 10~3
6.04 x 10~3
Emissions Caused
Lung Cancer
Average Yrs. of
Lifespan Lost
-
12.34
12.36
12.39
12.41
12.43
12.44
Deaths/Yr.
Due to
Coke Oven
Emissions
-
125.0
22.0
1.8
.4
.1
.2
                                                                         Total=149.5/Yr,

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                                    SECTION 9
              ENVIRONMENTAL REQUIREMENTS IN THE COKE OVEN INDUSTRY

     The section discusses existing and proposed Federal and State lavs, rules
and regulations pertaining to environmental control in the coke oven industry.
It is not intended to represent all applicable regulatory requirements,
particularly with respect to water quality standards, due to their variations
from state to state.

FEDERAL REGULATIONS
Air Pollution Control Standards
     1.   Prevention of Significant Air Quality Deterioration (PSD) program
          was incorporated in the Federal Clean Air Act Amendments of 1977 (PL
          95-95, August 7, 1977) under Part C, Subpart I.
          This regulatory program requires that every major new and major
          modification of industrial sources of air pollution must obtain a
          PSD permit in order to construct the source or facility.  A major
          source is any source in one of 28 established categories that has
          the potential (before controls) to emit 100 tons per year (approxi-
          mately 25 Ibs/hr) or more of any pollutant regulated by the Clean
          Air Act.
          Included in the 28 major source categories are:  coke oven batteries,
          fuel conversion plants and sulfur recovery plants, which are pertinent
          to this study report.  The regulated pollutants presently include:
          particulate matter, SO-, NO , CO, hydrocarbons, photo-chemical
                                fc    2£
          oxidants, total flourides, sulfuric acid mist, asbestos, beryllium,
          mercury, vinyl chloride, benzene and lead.
                                     -182-

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The requirements for obtaining a PSD permit are:
A.   Air Quality Assessment
     A permit application must be accompanied by an air quality
     assessment that satisfactorily demonstrates that no increment
     or NAAQS will be contravened.  This assessment must be based on
     approved air pollutant dispersion modeling techniques and, in
     the case of the NAAQS, must be supported by as much as one
     year's worth of monitoring data.

B.   Best Available Control Technology (BACT)
     BACT is the best achievable control technology when economic,
     energy and other costs are considered on a case-by-case basis.
     BACT can range from the stringency of Lowest Achievable Emission
     Rate (LAER) down to the New Source Performance Standards  (NSPS)
     as the highest acceptable emission rate.
     If any control technology less than the best achievable is
     selected, then that selection must be justified by a comparison
     between the economic and energy cost saved and the additional
     environmental cost accrued.
     BACT is required for all pollutants for which the new source or
     modification is considered major.

C.   Impact Analysis and Public Participation
     Addressed in the permit application must be the impact on:
     vegetation with commercial or recreational value, soils and
     visibility.  Also the impact in the environment of secondary or
     induced growth must also be evaluated.
     The public must be afforded an opportunity for comment and
     hearing on the permit application; and in  the preliminary
     determination to approve the application prior to issuing a
     construction permit.
                            -183-

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          D.    New Sources  in Non-attainment  Areas
               All major new sources or major modifications  proposed for
               location in  areas  where levels of any pollutant  (for which they
               are considered major emitters) are currently  exceeding a NAAQS
               must meet the following four conditions in order to  secure a
               state Stationary Source Review (SSR)  permit (a precondition to
               receiving a  PSD permit).
               1.    LAER is required.
               2.    All other sources owned by the  same owner in the same
                    state must be in compliance with the SIP or on  an approved
                    compliance schedule.
               3.    Off-setting reductions in emissions from existing sources
                    must be provided.
               4.    There must be a net improvement in air quality  resulting
                    from the off-sets.
          Standards of Performance for New Stationary Sources have  not been
          written for the coke oven industry.  Instead, the EPA* has been
          considering emission standards for  various coke making operations
          under the National Emission Standards for Hazardous Air Pollutants
          (NESHAPS 40 CFR 61). The purpose of promulgating regulations under
          this category is  to provide an umbrella coverage of new and existing
          coke plants while acknowledging the carcinogenic properties of the
          contaminants.  It is anticipated that the EPA will propose an initial
          regulation to control the top side  charging of coke ovens by visible
          emission limitations.  Also, it is  expected that specific emission
          standards will be set for benzene and heavier polycyclic  aromatic
          hydrocarbons which will be applicable to  the coke oven industry.
          National Primary  and Secondary Ambient Air Quality Standards (40 CFR
          50).  Table 9-1 provides ambient air quality standards for six major
          air contaminants.  These standards  serve  as guidelines to the states
^Private communications with EPA,  Standards Group,  R.T.P., North Carolina.
 Also, the Precip Newsletter - March 20, 1978,  No.  26,  page 4.
                                     -184-

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            TABLE 9-1,
   Pollutant
  NATIONAL AMBIENT AIR QUALITY STANDARDS
  (SOURCE - BIBLIOGRAPHY 19)
    Averaging
      Time
 Primary
Standards
   Secondary
   Standards
Particulate matter*
Sulfur dioxide
Carbon monoxide
Photochemical**
oxidants
Hydrocarbons+
(nonmethane)

Nitrogen dioxide
Lead
Annual (geometric mean)

24 - hour

Annual (Arithmetic
mean)

24 - hour


 3 - hour


 8 - hour


 1 - hour  '


 1 - hour

 3 - hour
(6 to 9 a.m.)
Annual (Arithmetic
mean)
 3 - month average
 75 yg/in

260 yg/m
 80 yg/m3
 (0.03 ppm)

365 yg/m3
 (0.14 ppm)
 10 mg/m
 (9 ppm)
        3
 40 mg/m
(35 ppm)
235 yg/m3
 (0.12 ppm)
        3
160 yg/m
 (0.24 ppm)

100 yg/m
 (0.05 ppm)
  1.5 yg/m3
   60 yg/m"

  150 yg/m3
1,300 yg/ni
   (0.5 ppm)

Same as primary
Same as primary
Same as primary
Same as primary
Same as primary
*  The secondary annual standard  (60 yg/m  )  is a guide  to be used  in assess-
   ing implementation plans to achieve  the 24 - hour  secondary  standard.

** Expressed as ozone by the Federal Reference Method.

4-  This NAAQS is for use as a guide in  revising implementation  plans to
   achieve oxidant standards.
                                    -185-

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          for meeting air quality goals by incorporating them in their State

          Implementation Flans.   National standards apply when state standards
          of equivalent or more stringent levels have not been adopted.
Water Pollution Standards
     3.
Refuse Act of 1899 C33 USC 407); NPDES permit.

This act makes unlawful the discharge of refuse into navigable

waters or tributaries of navigable waters; or the deposit of refuse

on the banks of navigable waters where it may be washed into those

waters.  Discharges may, however, be permitted under the National

Pollution Discharge Elimination System (NPDES) pursuant to the

Federal Water Pollution Control Act Amendments of 1972 (33 USC, 1251

et. seg.).

Toxic Pollutant Effluent Standards (40 CFR 129).

The pollutants presently regulated by these standards are not related

to the coke oven industry effluent compounds.  It is expected that

pollutants characteristic of the effluents from the coke oven industry

such as particulate polyeyelie aromatic hydrocarbons, benzene, metals

and heavy metals will be proposed and regulated in the near future.

Effluent Guidelines and Standards (40 CFR 420) Subpart A; Byproduct

Coke Subcategory.
          Basis

          BATEA1, NSPS1
          (Expressed as
           kg/kkg)
          Product
                  Effluent
                  Characteristic
                           2
                  Cyanide A
                  Phenol
                  Ammonia
                  Sulfide
                  Oil and grease
                  TSS
                  pH
 Maximum for
 Any One Day

   .0003
   .0006
   .0126
   .0003
   .0126
   .0312
Within the
range from
6.0 - 9.0
Avg. of Daily
Values For 30
Consecutive Days
Shall Not Exceed

     .0001
     .0002
     .0042
     .0001
     .0042
     .0104
1.  Limitations specified may be exceeded up to 25 percent by those facilities
    equipped with gas desulfurization units and up to 70 percent for those
    utilizing the indirect ammonia recovery process.

2.  "Cyanide A" means those cyanides amenable to chlorination.
                                     -186-

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EPA Water Quality Criteria
     States are required to adopt water quality standards and a plan for
enforcement and implementation consistent with the goals of the Federal Water
Pollution Control Act Amendments of 1972 (40 CFR, Part 120).
     Recognized versions of water quality criteria include criteria developed
by the Department of Interior in 1968, criteria published by the National
Academy of Sciences in 1972, and EPA1s 1976 Quality Criteria for Water.
States may use any one of these criteria documents as guidelines in setting
discharge standards.
     It should be understood that water quality criteria do not have direct
regulatory use, but are used for judgment of certain standards associated with
water quality programs.
     Criteria pertinent to the coke oven industry taken from the proposed EPA
1976 Quality Criteria for Water are presented below:
     Parameter
     Ammonia
     Cyanide
     PH
     Phenol
     Solids & Turbidity
                        Criterion
0.02 gm/1 (as un-ionized ammonia) for freshwater
aquatic life.

5.0 yg/1 for fresh and salt water aquatic life and
wildlife.

5-9 for domestic water supplies (Welfare)
6.5 - 9.0 for freshwater aquatic life
6.5 - 8.5* for saltwater aquatic life
*but not more than 0.2 units beyond the normally
 occurring range.

1 yg/1 for domestic water supply (Welfare),  and
to protect against tainting of fish flesh.

For freshwater fish and other aquatic life settleable
and suspended solids should not reduce the depth of
the compensation point for photosyrtthetic activity
by more than 10 percent from the seasonally
established norm for aquatic life.
                                     -187-

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Parameter
Oil & Grease
Sulfide—
Hydrogen Sulfide:
                    Criteria
Virtually free from oil and grease, particularly from the
tastes and odors that emanate from petroleum products, for
domestic water supplies.
The following apply for Aquatic Life;
(1)  Levels of individual petrochemicals in the water
     column should not exceed 0.01 ppm of the lowest
     continuous flow 96-hr.  LC,-n to several important
     marine species, each having a demonstrated high
     susceptibility to oils and petrochemicals;
(2)  Levels of oils or petrochemicals in the sediment
     which cause deleterious effects to the biota should
     not be allowed;
(3)  Surface waters shall be virtually free from floating
     non-petroleum oils of vegetable or animal origin, as
     well as petroleum derived oils.

2  g/1 undissociated H_S for fish and other aquatic life
in fresh and marine water.
Solid Waste Disposal Standards
     The Resource Conservation and Recovery Act of 1976 stipulated that within
18 months  regulations would be developed by the EPA to handle and dispose of
hazardous waste materials.  Since many of the particulates that are captured
from the coke ovens are, or could be, classified as hazardous compounds, they
would fall under the requirements of this law and the proposed regulations.
It is expected that the regulations will require safe handling, labeling and
identification of the hazardous materials, proper containerizing, safe and
effective transport, and disposal.
      (NOTE:  Recent conversations with the EPA indicate that the 18 months
              deadline are expected to be extended an additional 6-12 months.)
                                     -188-

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STATE REGULATIONS
Air Pollution Control Standards
     An analysis was made of five (5) states which specifically regulate coke
oven plants and their air emissions.  These states collectively encompass more
than 37 percent of the total coke production and have more than 41 percent of
the total number of coke plants in the United States.
     Basically, the states all regulate the fugitive smoke and particulate
matter emissions that emanate from the coke oven batteries and the quench
towers.  The following are the types of operations and maintenance procedures
regulated:
     1.   Unloading and Transferring of Coal and Coke - These operations are
          required to implement unspecified but reasonable control measures to
          prevent emissions.
     2.   Charging Operations -
          a)   Open Charging - Visible emissions are limited to no more than
               15 seconds during any coke oven charging operation.  The opacity
               of the emissions is limited to less than or equal to 30 percent.
          b)   Closed Charging - Visible emissions are limited to one charge
               out of any ten consecutive charges.
     3.   Pushing Operations -
          a)   Visible emissions are limited to less than, or equal to, 20
               percent opacity for up to one minute per push.  New coke plants
               shall be equipped with enclosed pushing devices equipped with
               particulate collection systems.
     4.   Topside emissions -
          a)   Leaks shall be wet-sealed or the oven shall not be recharged
               until repairs are made.
          b)   At no time shall there be leaks in more than 5 percent of the
               off-take piping and no more than 2 percent from the charging
               hold lids on any one battery, excluding visible emissions from
               open standpipe caps.
     5.   Coke Oven Door Emissions -
          a)   Visible emissions are restricted to 15 percent of the doors on
               any battery at any time.

                                     -189-

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          b)   Self sealing doors must be repaired prior to subsequent charge
               if they fail to seal.
          c)   Luted doors that fail to seal after charging must be reluted
               promptly.
          d)   Operators must have facilities to maintain and repair coke doors
               with maintenance inventory of one door per 12 ovens operated.
     6.   Oven Maintenance -
          a)   Ovens shall be maintained in good condition.
          b)   Oven cracks are to be sealed as doon as practicable following
               detection.
          c)   Records are to he retained on maintenance of doors, burners and
               interiors.
     7.   Combustion Stacks -
          a)   Visible emissions are limited to less than or equal to, 20
               percent opacity except for 3 minutes in any consecutive 60
               minutes•
     8.   Quenching -
          a)   Quench towers must have baffles installed.
          b)   Water introduced to the quench station must have a quality
               approved by the control agency.
     New Byproduct coke oven batteries must be equipped with control equipment
such as, but not limited to, hood(s) and/or gas mover(s) capable of capturing,
containing and collecting gases and particulate matter resulting from distil-
lation, charging, pushing and quenching of coke from an oven battery.  Such
equipment shall employ the best practicalbe control technology currently
available.
     New Beehive coke ovens are either prohibited from construction and
operation or, if permitted to be constructed, must have all gas and particulate
matter emissions directed through an acceptable air pollution control device.
     Table 9-2, "Summary of State Air Pollution Control Regulations for the
Control of H S Emissions from Byproduct Coke Ovens," gives the limitations
from five states which regulate the emission of sulfur compounds  (measured as
H?S) from coke oven gas.  The majority of these states require that the coke
oven gas be desulfurized down to 50 grains per one hundred dry standard cubic
                                     -190-

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     TABLE 9-2.  SUMMARY OF STATE AIR POLLUTION CONTROL REGULATIONS FOR THE

                     CONTROL OF 1LS EMISSIONS FROM BYPRODUCT COKE OVENS
State
Alabama
Regulations

Chap. 5 - Control of
sulfur oxides, 5.5 Process
Industries - General
  H S/SO   Limitations
    £   X
   1.   Cannot construct  or  operate
       unless source  meets
       applicable  New Source
       Performance Standards  (NSPS)
       and utilize hest  practicable
       control technology currently
       available.   (BPCTCA)

    2,  Cannot exceed  primary  &
       secondary National Ambient
       Air Quality Standards  (NAAQS)
       for SO
Illinois
Rule 204 (f) Sulfur
standards and limita-
tions for process
emissions sources
(1) Sulfur Dioxide
    and Limitations
(A)     Sulfur dioxide emissions
       from process sources cannot
       exceed 2,000 ppmv.
New York       New York  contaminant
               emissions  from Ferrous
               Jobbing Foundries and
               Byproduct  coke oven
               batteries, Part 214,
               Byproduct  coke oven
               batteries, Sections 214.4
               Sulfur Compound Emissions
                                   Sources are not permitted  to
                                   burn or flare process gas
                                   containing more than 50 grains
                                   of sulfur compounds  (measured
                                   as H2S) per 100 standard
                                   cubic  feet of gas.
P ennsyIvania
Chapter 123,  123,2
Byproduct  coke oven gas
  a)   Coke oven gas must be burned
       prior to emission to atmosphere.

  b)   Burning or flaring is prohibited
       if Byproduct gas contains more
       than 50 grains of sulfur
       compounds per 100 dry standard
       cubic feet of gas (expressed as
       equivalent hydrogen sulfide).
                                      -191-

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                             TABLE 9-2  (Continued)
State          Regulations                    H S/SO  Limitations
Virginia       Emission standards for         Hydrogen Sulfide may not be
               coke ovens and charcoal        emitted from any process stream
               kilns  (Rule EX-4) Part IV     which contains H_S in concen-
               4.91 other Byproduct coke      trations greater than 15 grains
               ovens, emission standards       per 100 cubic feet of gas without
               for gaseous pollutants         burning or removing H S in excess
               (Rule EX-5)                    of this concentration.  This
               Cc) Hydrogen Sulfide           limitation is acceptable provided
                                              that the final SO  emission
                                                               x
                                              limitations are not violated.
                                     -192-

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feet of gas before burning or flaring.  The most stringent limitation, 15
grains per 100 cubic feet of gas, was promulgated by the State of Virginia.
The purpose of this regulation is to achieve acceptable ambient air levels of
sulfur oxide emissions.

Water Pollution Control Standards
Water Quality Criteria
     The states' water quality criteria/standards usually consist of water use
classifications, water use descriptions and specific standards, as well as
general water quality criteria.  The specific water quality standards which
are applicable to a given area depend on the water use classification that may
be assigned to an area.
     A review was made of the five major coke producing states to examine
specific water quality criteria applicable to coke oven emissions.  Based on
published state regulations and The Bureau of National Affairs (SNA) publi-
cations on state water laws at the time of this writing (current to 1976),
only Pennsylvania and West Virginia had published promulgated criteria.

Solid Waste Disposal Standards
Hazardous Waste Handling and Disposal
     The EPA is delegating the enforcement authority under the "Resource
Conservation and Recovery Act of 1976" to the states.  Although the specific
regulations for the handling, transport and disposal have not been promulgated
by the EPA, some states such as Pennsylvania have already implemented their
own hazardous materials transporting and disposal regulations.
                                     -193-

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                                BIBLIOGRAPHY
 1.   Albert, R.E.  Carcinogens Assessment Group's Preliminary Report
      on Population Risk  to Ambient Coke Oven Exposures.  External Review
      Draft, U.S. Environmental Protection Agency, Office of Research and
      Development,  Washington, B.C., March 1978.  20 pp.

 2.   American  Iron &  Steel Institute.  Comments of A.I.S.I. on Cyrus W.
      Rice Draft Document for Effluent Limitations Guidelines and New
      Source Performance  Standards  (Iron and Steel Industry), July  1973.

 3.   American  Iron &  Steel Institute.  Comments of A.I.S.I. on Calspan
      Draft Final Report, Alternatives for Hazardous Waste Management in
      the Metals Smelting and Refining Industries,  April  1977.  7 pp.

 4.   American  Iron &  Steel Institute.  Testimony of Documentary Evidence
      at Hearing by A.I.S.I.-OSHA Docket No. H-059 on Proposed Standard
      for Regulating Occupational Exposure to Benzene.  July 11, 1977

 5.   American  Iron &  Steel Institute.  Comments of A.I.S.I. on EPA's
      Proposed  Effluent Limitations Guidelines  and Standards  (Iron and
      Steel Paint Source  Category), April 5, 1974.  108 pp.

 6.   American  Petroleum  Institute.   API Manual on Disposal of Refinery
      Wastes.   Washington, D.C.   1969.

 7.   Arthur G. McKee  & Co.   The  Capabilities and Costs of Technology,
      Associated with  Achievements  of the Requirements  and Goals of  the
      Federal Water Pollution Control Act Amendments of 1972 for the
      Iron and  Steel Industry.  U.S.  National Commission on Water Quality,
      November  1975.
 8.   Balla, P.A. and  Wieland, G.E.   Performance of Gas-Cleaning System on
      Coke Oven Larry  Car at  Burns  Harbor.  American Iron & Steel Institute,
      Regional  Technical  Meeting, Chicago, 111., October 15, 1970.   15 pp.

 9.   Barker, J.E.  and Thompson,  R.J.   Biological Removal of Carbon  and
      Nitrogen  Compounds  from Coke  Plant Wastes.  EPA-R2-73-167, U.S.
      Environmental Protection Agency,  Office of Research and Development,
      Washington, D.C., April 1973.

10.   Barnes, Thomas M.,  Lownie,  Harold W. Jr., and Varga, John, Jr.
      Summary Report on Control of  Coke Oven Emissions  to The American
      Iron and  Steel Institute, December 31, 1973.  Battelle Columbus
      Laboratories, Columbus, Ohio.   88 pp.

 11.  Bertrand, R.R. and  Magee, E.M.  Trip Report for Commercial
      Gasification  Plants.  U.S.  Environmental  Protection Agency, Office
      of Research and  Development,  Washington,  D.C., November  1974.

 12.  Beychok,  M.R. Aqueous  Wastes.  John Wiley and Sons Inc.  New  York,
      N.Y.   1967.
                                      -194-

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13.  Bonham, J. W. and Atkins, W.T.   Process Comparison Effluent  Treatment
     Ammonia Separation.  E.R.D.A.  Document No.  FE-2240-19, June   1975.

14.  Calsjtan Corporation,  Assessment of Industrial Hazardous Waste
     Particles in the Metal Smelting and Refining Industry, Volume I,
     Executive Summary.  U.S. Environmental Protection Agency, Office
     of Solid Waste, April  1977.

15.  Cannon, J.S.  Environmental Steel Pollution in the Iron and  Steel
     Industry.  J. M. Halloran, ed., Praeger Publishers, New York-London,
     1974.  521 pp.

16.  Christensen, K.G, and Stupin,  W.J.  Acid Gas Removal in Coal
     Gasification Plants.  Ninth Synthetic Pipeline Gas Symposium,
     Oct. 31-Nov. 2, 1977.
17.  Cleland, J.G. and Kingsbury, G.L.  Summary of Key Federal Regulations
     and Criteria for Multimedia Environmental Control.  Contract No.
     68-02-1325, U.S. Environmental Protection Agency, Office of  Research
     and Development, Washington, D.C., June 1977.  132 pp.
18.  Colaianni, L.J.  Coke Oven Offgas Yields Fuel, Chemical By-Products.
     Chemical Engineering, March 29, 1976.
19.  Connor, J.S. and Armentrout, F.S.  Environmental Steel Update
     Pollution in the Iron and Steel Industry.  W. C. Schwartz, ed,,
     Council on Economic Priorities, New York, N.Y.  1977.  251 pp.

20.  Cooper, F. et al.  Emission Testing and Evaluation of Ford/Koppers
     Coke Pushing Control System; Volume I.  Final Report.
     EPA-600/2-77-187a, U.S. Environmental Protection Agency, Office
     of Research and Development, Washington, D.C.  September  1977.  263 pp.

21.  Dulaney, E.L., Development Document for Effluent Limitations
     Guidelines and New Source Performance Standards for the Steel Making
     Segment of the Iron and Steel Manufacturing Point Source Category.
     EPA 440/1-74-024-a, U.S. Environmental Protection Agency, Washington,
     D.C., June 1974.  461 pp.
22.  Dunlap, R.W. and McMichael, F.C. "Air, Land or Water: The Dilemma of
     Coke Plant Waste Water Disposal."  American Iron & Steel Institute
     83rd General Meeting, Waldorf Astoria Hotel, New York, N.Y.,
     May 21, 1975.  26 pp.
23.  Dunlap, R.W. and McMichael, F.C.  Treatment technology is suggested
     for... Reducing coke plant effluent.  Environmental Science & Technology,
     Vol. 10, No. 7, July 1976.  4 pp.
24.  Duprey, R.L.  Compilation of Air Pollutant Emission Factors.
     Third Ed.,  Public Health Service Publication 999-AP-42,
     U.S. Environmental Protection Agency, Research Triangle Park, N.C.
     August 1977.

25.  Epperly, W.R. and Taunton, J.W.  Development of the Exxon Donor Solvent
     Coal Liquefaction Process.  85th National Meeting of A.I.C.H.E.,
     Phila., Pa. June 7, 1978.
                                      -195-

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26.  Forney, A.J. et al.   Analysis of Tars, Chars, Gases and Water in
     Effluents from the Synthane Process.   U.S. Bureau of Mines
     Technical Progress Report 76, Pittsburgh Energy Research Center,
     Pittsburgh, Pa.

27.  Friedman, B.M. et al.  The Stretford Process.  Contract No.  68-02-2167,
     Task 4, U.S. Environmental Protection Agency, Office of Research and
     Development, Washington, B.C.  January  1978.  56 pp.
28.  Goar, G.B.  Tighter Controls of Claus Plants.  The Oil and Gas J.
     August  1977.

29.  Goldman, G.K.  Carbonization, Liquid Fuels from Coal.  Noyes Data Corp.,
     New Jersey, 1972.

30.  Goldstein, D.J. and Yung, D.  Water Conservation and Pollution Control
     in Coal Conversion Processes.  EPA-600/7-77-065.  U.S. Environmental
     Protection Agency, Office of Research and Development, Washington, D.C.
     June  1977.

31.  Guerrin, M.R. et al.  Polycyclic Aromatic Hydrocarbons from Fossil Fuel
     Conversion Processes.  Conf-770963-1.  Oak Ridge National Laboratories,
     Oak Ridge, Tenn., 1977.  26 pp.

32.  Hardin, B.D.  Criteria for a recommended standard... Occupational
     Exposure to Coke Oven Emissions.  U.S. Department of Health, Education
     and Welfare, National Institute for Occupational Safety and Health,
     Cincinnati, Ohio.  1973.

33.  Harrison, J.L.  Iron and Steel Works Pollution Control:  Water and
     Effluents.  Steel Times, September 1974.  7 pp.

34.  Homberg, O.A. and Singleton, A.H.  Performance and Problems of Claus
     Plant Operation on Coke Oven Acid Gases.  Air Pollution Control
     Association J.  25(4): 375-378, 1975.

35.  Hossain, S.M. et al.  Control Technology Development for Products/
     By-Products of Coal Conversion Systems.   EPA-600/7-78-063,
     U.S. Environmental Protection Agency, Office of Research and
     Development, Washington, D.C., April  1978.

36.  Jablin, R. and Chanko, G.P.  A New Process for Total Treatment of Coke
     Plant Waste Liquor.  A.I.C.H.E.  Symposium Series 70(136):713-722, 1973.

37.  Kostenbader, P.O. and Flecksteiner, J.W.  Biological Oxication of Coke
     Plant Waste Ammonia Liquor.  Water Pollution Control Federation J.,
     41(2)  Feb. 1969.

38.  Lowry, H.H., ed.  Chemistry of Coal Utilization.  Supplementary Volume.
     John Wiley & Sons Inc., New York-London, 1963.  1142 pp.

39.  Magee, E.M.  Evaluation of Pollution Control in Fossil Fuel Conversion
     Processes.  EPA-600/2-76-101.  U.S. Environmental Protection Agency,
     Research Triangle Park, N.C.  April  1976.
40.  Massey, M.J. and Dunlap, R.N.  Economics and Alternatives for Sulfur
     Removal from Coke Oven Gas.  Air Pollution Control Association J.
     25(10): 1019-1027, 1975.
                                    -196-

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41.  Mazumdar, S. et al.  An Epidemiological Study of Exposure to Coke Tar
     Pitch Volatiles among Coke Oven Workers.   Air Pollution Control
     Association J.  25(4): 382-389, 1975.
42.  McGannon, H. E., ed.  The Making, Shaping and Treating of Steel.
     United States Steel Corporation, Ninth Edition, 1971.   1420 pp.
43.  Mezey, E.J. et al.  Fuel Contaminants Volume 2.  Removal Technology
     Evaluation.  EPA-600/2-76-177b, U.S.  Environmental Protection Agency,
     Office of Research and Development, Washington, B.C.,  September  1976.
     298 pp.
44.  Naso, A.C. and John, E.T.  Physical-Chemical Treatment of Cleveland
     District Coke Plant Wastewaters.  American Iron & Steel Institute
     85th General Meeting, Waldorf-Astoria Hotel, New York, N.Y.
     May 25, 1977.  8 pp.
45.  Nicklin, T.  Recovery of ADA and Vanadium Salts from Stretford Waste
     Liquor.  U.S. Patent No. 3,810, 833 Northwestern Gas Board, May 14, 1974.

46,  Nonhebel, G., ed.  Gas Purification Processes.  George Newnes Limited,
     London, 1964,
47.  O'Connor, R. B.  Improving the Environmental Health of Coke Oven Workers.
     American Iron & Steel Institute 78th General Meeting,  New York, N.Y.,
     May 27, 1970.  6 pp.
48.  Parsons, W.A. and Nolde, W.  Applicability of Coke Plant Water Treatment
     Technology to Coal Gasification.  EPA-600/7-7B-063, U.S. Environmental
     Protection Agency, Washington, D.C.  April  1978.  15  pp.

49.  Pasztor, L. and Floyd, S.B., Jr.  Managing and Disposing of Residues from
     Environmental Control Facilities in the Steel Industry.  U.S. Environmen-
     tal Protection Agency Office of Research & Development, June 1976.  177 pp.

50.  Pearson, E.F.  Research Study of Coal Preparation Plant and By-Product
     Coke Plant Effluents.  EPA-660/2-74-050, U.S. Environmental Protection
     Agency, Office of Research and Development, Washington, D.C., April 1974
     287 pp.

51.  Radian Corp.  Industrial Process Profiles for Environmental Use:  Chapter
     24.  The Iron and Steel Industry.  PB-266 226.  U.S. Environmental
     Protection Agency, Research Triangle Park, N.C., Feb.  1977.
52.  Rudolph, H. and Sawyer, S.  Engineering Criteria for the Envirotech/
     Chemico Hooded Quench Car System.  Annual Meeting of the Association of
     Iron and Steel Engineers, Pittsburgh, Pa.  Sept. 27-29, 1976.  30 pp.

53.  Schueneman, J. J. et al.  Air Pollution Aspects of the Iron and Steel
     Industry.  U.S. Dept. of Health, Education and Welfare, Public Health
     Service Publication No. 499-AP-l, Cincinnati, Ohio, June 1963.  118 pp.

54.  Seil, G.E.  Dry Box Purification of Gas.  American Gas Association, 1943.
55.  Serrurier, R.  Prospects for Marketing Coal Gasification By-Products.
     Hydrocarbon Processing J., September  1978.

56.  Sheldrake, C. William and Homberg, Otto A.  "Coke Oven Gas Desulfuriza-
     tion - State of the Art."  American Iron & Steel Institute, 85th General
     Meeting.  Waldorf Astoria Hotel, New York, N.Y.  May 25, 1977.  24 pp.

                                     -197-

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 57.   Shreve, R.N.  Chemical Process Industries.  3rd Edition.  McGraw-Hill,
      Inc., New York, N.Y.  1967.  905 pp.

 58.   Singer, P.C. et al.  Composition and Biodegradability of Organics in
      Coal Conversion Waste Waters.  EPA-600/7-78-063.  U.S. Environmental
      Protection Agency, Washington, D.C., April 1978.

 59.   Sinor, J.E., et.  Evaluation of Background Data Relating to New
      Source Performance Standards for Lurgi Gasification.  EPA-600/7-77-057,
      U.S. Environmental Protection Agency, Research Triangle Park, N.C.
      June, 1977

 60.   Smith, H.I. and Werner, G.J.  Coal Conversion Technology,  A Review.
      Millmerran Coal Pty. Ltd., Brisbane, Australia, May  1975.

 61.   Smith, W.M.  Evaluation of Coke Oven Emissions.  American Iron & Steel
      Institute.  78th General Meeting, New York, N.Y.  May 27, 1970.  17 pp.

 62.   Stellman, J.M.  An Assessment of the Health Effects of Coke Oven
      Emissions.  External Review Draft, U.S. Environmental Protection Agency,
      Office of Research and Development, Washington, D.C., April 1978.  145 pp.

 63.  Strup,  P.E. et al.   Sampling and Analysis of Coke Oven-Door Emissions.
     U.S. Environmental Protection Agency, PB 276-485/AS. October 30,  1977.
     182 pp.

 64.   Suta, B.E.  Human Population Exposures to Coke-Ovens Atmospheric Emissions,
     U.S. Environmental Protection Agency, Contract 68-01-4314, November  1977.
      107 pp.

 65.  The APC Monitor.  Report to the Air Pollution Control Board for the Month
     of October 1978.  Air Management Services, Phila. Dept, of Public Health,
     Philadelphia, Pa.  23 pp.

 66.  Traubert, R.M.  Weirton Steel Division - Brown's Island Coke Plant, Iron
     and Steel Engineer, January 1977.  4 pp.

 67.  T.R.W.  Systems & Engrg.  Carcinogens Relating to Coal Conversion
     Processes.  E.R.D.A. Document No. FE-2217-1.  June  1976.  129 pp.

 68.  Voelker, F.C. Jr.  A Contemporary Survey of Coke-Oven Air Emissions
     Abatement.  Iron and Steel Engineer, February 1975.  8 pp.

69.  Wilson,  P.J.  and Wells, J.R.   Coal,  Coke and Coal Chemicals.  McGraw-Hill
     Book Company,  Inc.,  New York,  N.Y.,  1950.
                                     -198-

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                APPENDIX A.  SI  (METRIC) CONVERSION FACTORS
To Convert From
ft/s"
                To

          Acceleration

                     ,2 , , 2.
      meter per second  (m/s )
Multiply By
3.048-000 E-01
Acre (U.S. survey)
ft2
in2
yd2
                  12
              Area
           2   2
      meter  (m )
           2   2
      meter  (m )
           2   2
      meter  (m )
           2   2
      meter  (m )
4.046 873 E+03
9.290 304 E-02
6.451 600 E-04
8.361 274 E-01
British thermal unit
   (mean)
Calorie (kilogram, mean)
Kilocalorie  (mean)
Energy (Includes Work)

      joule (J)

      joule (J)
      joule (J)
1.055 87  E+03

4.190 02  E+03
4.190 02  E+03
foot
inch
yard
         Length

      meter (m)
      meter (m)
      meter (m)
3.048 000 E-01
2.540 000 E-02
9.144 000 E-01
grain
grain
pound  (Ib avoirdupois)
ton  (metric)
ton  (short, 2000 Ib)
          Mass

      kilogram (kg)
      kilogram (kg)
      kilogram (kg)
      kilogram (kg)
      kilogram (kg)
6.479 891 E-05
1.000 000 E-03
4.535 924 E-01
1.000 000 E+03
9.071 847 E+02
Ib/ft'
  Mass Per Unit Area
                        2       2
      kilogram per meter   (kg/m )
 4.882  428 E+00
                                       -199-

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To Convert From
                             APPENDIX A  (Continued)
To
Multiply By

degree Celsius
degree Fahrenheit
degree Fahrenheit
degree Rankine
Kelvin

ft/h
ft/min
ft/8
in/s

centipoise
centistokes
poise
stokes
acre-foot (U.S.
survey)
barrel (oil, 42 gal)
ft3
gallon (U.S. liquid)
liter*
Volume
ft^/min
fWs
gal (U.S. liquid/day)
gal (U.S. liquid/min)
Temperature
Kelvin (K)
degree Celsius
Kelvin (K)
Kelvin (K)
degree Celsius
Velocity (Includes Speed)
meter per second (m/s)
meter per second (m/s)
meter per second (m/s)
meter per second (m/s)
Viscosity
pascal second (Pa.s)_
meter per second (m /s)
pascal second (Pa.s)2
meter per second (m /s)
Volume (Includes Capacity)
3 3
meter (m )
3 3
meter (m )
meter- (m )
meter (m )
3 3
meter (m )
Per Unit Time (Includes Flow)
3 3
meter_ per second (m,/s)
meter- per second (m_/s)
meter, per second (m»/s)
meter per second (m /s)

tv = t + 273.15
K °C
t = (t - 32)/1.8
°C °F
t.. - (t + 459.67)/1.8
K °F
t = t /I. 8
K °R
t = tv - 273.15
°c K

8.466 667 E-05
5.080 000 E-03
3.048 000 E-01
2.540 000 E-02

1.000 000 E-03
1.000 000 E-06
1.000 000 E-01
1.000 000 E-04
1.233 489 E+03
1.589 873 E-01
2.831 685 E-02
3.785 412 E-03
1.000 000 E-03
4.719 474 E-04
2.831 685 E-02
4.381 264 E-03
6.309 020 E-05
*In 1964 the General Conference on Weights and Measures adopted the name
 liter as a special name for the cubic decimeter.  Prior to this decision
 the litre? differed slightly (previous value, 1.000028 dm ) and in expression
 of precision volume measurement this fact must be kept in mind.
                                      -200-

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                             APPENDIX A  (Continued)
To Convert From
Ib/ft
Ib/in
                                        To

                              Mass Per Unit Length

                              Kilogram per meter  (kg/m)
                              Kilogram per meter  (kg/m)
Multiply By
1.488 164 E+00
1.785 797 E+01
Ib/h

Ib/min

ton (short)/h
                       Mass Per Unit Time  (Includes Flow)

                              Kilogram per second
                                 (kg/s)
                              Kilogram per second
                                 (kg/s)
                              Kilogram per second
                                 (kg/s)
1.259 979 E-04

7.559 873 E-03

2.519 958 E-01
lb/ft:
             Mass J?er Unit Volume  (Includes Density & Mass Capacity)
                                                3
Ib/gal (U.S. liquid)


Ib/yd3
                              Kilogram per meter"

                                 (kg/m3)
                                                 e
                              Kilogram per meter"

                                 (kg/m3)
                                                 /
                              Kilogram per meter"

                                 (kg/m3)
1.601 846 E+01


1.198 264 E+02


5.932 764 E-01
                                      Power
Btu (Thermochemical)/h        Watt  (w)
Btu (thermochemical)/h        Watt  (W)
cal (thermochemical)/min      Watt  (w)
cal (thermochemical)/s        Watt  (W)
                                                                 2.930 711 E-01
                                                                 2.928 751 E-01
                                                                 6.973 333 E-02
                                                                 4.184 000 E+00
                    Pressure or Stress  (Force Per Unit Area)

atmosphere (standard)         pascal  (Pa)
                              pascal  (Pa)
foot of water (39.2 F)
lbf/ft2
lbf/in2 (psi)
                              pascal  (Pa)
                              pascal  (Pa)
1.013 250 E+05
2.988 98  E+03
4.788 026 E+01

6.894 757 E+03
                                       -201-

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                                TECHNICAL REPORT DATA
                         (Please read Instructions on the reverse before completing)
 1. REPORT NO.
  EPA-600/7-79-184
                           2.
                                                      3. RECIPIENT'S ACCESSION NO.
4. TITLE AND SUBTITLE
Applicability of Coke Plant Control Technologies to
 Coal Conversion
                                5. REPORT DATE
                                 August 1979
                                6. PERFORMING ORGANIZATION CODE
7. AUTHOR(S)
S.M.Hossain,  P. F.Cilione, A. B.Cherry,  and
 W.J.Wasvlenko.  Jr.
                                                      8. PERFORMING ORGANIZATION REPORT NO.
9. PERFORMING ORGANIZATION NAME AND ADDRESS
Catalytic, Inc.
1500 Market Street
Philadelphia, Pennsylvania  19102
                                 10. PROGRAM ELEMENT NO.
                                 EHE623A
                                 11. CONTRACT/GRANT NO.

                                 68-02-2167, Task 10
12. SPONSORING AGENCY NAME AND ADDRESS
 EPA, Office of Research and Development
 Industrial Environmental Research Laboratory
 Research Triangle Park, NC  27711
                                 13. TYPE OF REPORT AND PERIOD COVERED
                                 Task Final; 8/77 - 3/79
                                 14. SPONSORING AGENCY CODE
                                  EPA/600/13
is.SUPPLEMENTARY NOTES fERL-RTP project officer is Robert A.  McAllister, Mail Drop 61,
919/541-2134.
16. ABSTRACT
              repOr^ gjyes results of comparisons of process and waste stream
characteristics from the Byproduct coke oven process with selected gasification and
liquefaction processes.  It includes recommendations regarding control technologies
for air, water, and solid wastes. Coke oven control technology was reviewed exten-
sively. State and Federal regulations for the disposal and treatment of coke oven
wastes are presented, along with a brief assessment of health effects attributed to
coke oven emissions. Study results indicate that a number of coke oven control tech-
nologies  are applicable to coal conversion systems , especially those dealing with
desulfurization, fugitive emissions, byproduct recovery /upgrading, and wastewater
treatment. Byproduct upgrading and fugitive emission control technologies may be
readily transferrable to analogous coal conversion applications. Desulfurization and
wastewater  treatment technologies , however ,  cannot be transferred readily to appli-
cations where significant differences exist in the composition, temperature, and
pressure of the two categories of process/waste streams.  In these cases, laboratory
or pilot plant scale tests will be required with actual coal conversion wastes to deter-
mine the design bases and the treatability variations between coal conversion and
comparable coke oven streams .
 7.
                             KEY WORDS AND DOCUMENT ANALYSIS
                DESCRIPTORS
                                          b.lDENTIFIERS/OPEN ENDED TERMS
                                             c. COSATI Field/Group
Pollution
Coking
Coal
Liquefaction
Coal Gasification
Environmental Biology
Desulfurization
Leakage
Waste Water
Water Treatment
Pollution Control
Stationary Sources
Coal Conversion
Byproduct Coke Oven
  Process
Health Effects
Fugitive Emissions
13B
13H
21D
07D
07A
 8. DISTRIBUTION STATEMENT
 Release to Public
                     19. SECURITY CLASS (ThisReport)
                     Unclassified
                         21. NO. OF PAGES

                            212
                     20. SECURITY CLASS (This page)
                     Unclassified
                                             22. PRICE
EPA Form 2220-1 (9-73)
                  202

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