STATIONARY SOURCE ENFORCEMENT SERIES
   TECHNICflL SUPPORT DOCUfllENT
          FOR THE RECOmmENDED
LOWEST ACHIEVABLE EfTllSSION RATE
       FOR SO2 EfniSSIONS FROm
         -OVEN GAS COmBUSTION

                               \
                             A Hi :•' '
                U.S. ENVIRONMENTAL AGENCY
                   OFFICE OF ENFORCEMENT
       DIVISION OF STATIONARY SOURCE ENFORCEMENT
                  WASHINGTON, DC 20460

                        JANUARY 1977

-------
  TECHNICAL SUPPORT DOCUMENT FOR THE RECOMMENDED
 LOWEST ACHIEVABLE EMISSION RATE FOR SO2 EMISSIONS
           FROM COKE-OVEN GAS COMBUSTION
Prepared by the U.S. Environmental Protection Agency,
      Division of Stationary Source Enforcement
                    January 1977

-------
     This report was developed by the Technical Support Branch of the



Division of Stationary Source Enforcement between November 1976 and



January 1977.  Bernard Bloom was the principal investigator.



     Material in this report and its appendices is subject to the



Environmental Protection Agency business confidentiality regulations



 (40 CFR Part 2, Subpart B 41 Fed. Reg. 36906, et. seq.).  This document



has been circulatd to EPA offices and not to vendors, coking companies,



state or local agencies or other members of the public.  Freedom of



Information Act or other requests for this report from outside EPA



should be forwarded to the Director, Division of.Stationary Source



Enforcement, 401 M Street, S.W., Washington, D.C. 20460.  If distri-



bution to a member of the public is desired by an EPA office, the



Director of Division of Stationary Source Enforcement should be



notified before such disclosure is made.

-------
                        TABLE OF CONTENTS


                                                                      PAGE
LIST OF FIGURES	   IV

LIST OF TABLES	    V

Section  I.    INTRODUCTION	'	    1

Section II.    CONTROL TECHNOLOGY	    8


     A.   Liquid Absorption Processes	    8

          1.   Vacuum Carbonate	    8
          2.   Sulfiban	   15
          3.   Carl Still	   19
          4.   Diairox	   24


     B.   Sulfur Recovery Processes	   24

          1.   Glaus	   24

               (a)  SCOT	'	   27
               (b)  Beavon	   28
               (c)  IFF	   28
               (d)  Vfellman-Lord	   28

         .2.   Sulfuric Acid	   31


     C.   Liquid Oxidation Processes	   32

          1.   Stretford	   33
          2.   Takahax	   37


Section III.   ORGANIC SULFUR IN COKE-OVEN GAS	   45

Section  IV.   PERFORMANCE LEVELS	   48

Section   V.   MEASUREMENT METHOD	   59

-------
                                TABLE OF CONTENTS
                                   -(Continued)
                                                                          PAGE

Section  VI.   IMPACT OF CONTROL TECHNOLOGY	   65

          1.   Cost Inpact	   65
          2.   Energy Impact	   76

REFERENCES	   79

APPENDICES	

     A.   List of Vendors	   82

     B.   J & L Steel Organic Sulfide Data	   84
     C.   Process Appendix (separate folder)	

-------
                          LIST OF FIGURES





Figures





1.   Coke-Oven Gas Distribution in an Example Steel Plant



2.   Vacuum Carbonate Process Flowsheet



3.   Two-Stage Vacuum Carbonate Process Flowsheet



4.    (^S) vs. MEA Circulation Rate for Sulfiban at BSC, Bethlehem, PA.



5.   Carl Still Process Flowsheet



6.   Clairton Works Sulfur Recovery Flowsheet



7.   Stretford Process Flowsheet



8.   Takahax Process Flowsheet



9.   Liquid Absorption Options for COG Desulfurization



10.  Compliance Measurement locations
                                  IV

-------
                           LIST OF TABLES


Tables


1.   Composition of Coke-Oven Gas

2.   Technologies for Coke-Oven Gas Desulfurization

3.   Glaus Plant Tail Gas Treatment Technologies

4.   Vacuum Carbonate Plants in U.S.

5.   Sulfiban Plants in U.S.

6.   Sulfiban Performance Data

7.   Firma Carl Still Plants in U.S.

8.   Construction Records of Large Scale Units in Japan

9.   Relative Takahax Costs

10.  Takahax Performance Data
                                                              \
11.  Takahax Waste Air Stream Flows

12.  Organic Sulfide Concentrations in COG

13.  Liquid Absorption Process Comparisons

14.  Sulfur Recovery Performance Comparisons

15.  Overall Best Obtainable Performance by Liquid Absorption Systems

16.  Liquid Oxidation Process Comparisons

17.  Ranking of Coke-Oven Gas Desulfurization Technology Performance Levels

18.  COG Sampling Field Worksheet

19.  Costs for COG Desulfurization Systems at Republic Steel - Cleveland
     Works, $103

20.  Costs for 60 x 10  scfd COG Desulfurization Systems at YS & T,
     $103, May 1976

21.  Battery Limits Costs for Vacuum Carbonate Sulfiban, and Carl Still
     COG Desulfurization Systems
                                 V

-------
                            LIST OF TABLES
                             (Continued)
Tables


22.  Recent Vendor Bid

23.  Comparison of COG Desulfurization Costs

24.  Comparison of Alternative Emissions Control System Costs for
     a 10 LTD Sulfur Plant

25.  Energy Demands for Coke-Oven Gas Desulfurization Technologies

26.  Relative Energy Demand of COG Desulfurization Technolgies
                                 VI

-------
Section I.   INTRODUCTION





     This document presents a description of technology for the desulfurization


of coke oven gas.  It is intended to provide guidance to EPA technical staff


and policy makers in the implementation of significant deterioration and new


source review policies of EPA.  The information is also intended to be useful


in the development, revision, or the enforcement of existing State Implementation


Plan (SIP) standards.  This document has been prepared in conjunction with an


Office of Enforcement memorandum, "Guidance for Establishing the Lowest Achiev-


able Emission Rate for S02 from the Combustion of Coke-Oven Gas, January 5, 1977."


     EPA has not yet developed a New Source Performance Standard (NSPS) for this


source category.


     Coke-oven gas (COG) is produced during the coking of metallurgical coal


in by-product coke ovens.  As a result of the coking process a fraction of


the sulfur contained in this coal (25-30%) is transferred to COG in the form


of hydrogen sulfide  (H-S), carbon disulfide (CS2), and carbonyl sulfur (COS).


Upon subsequent combustion these gases release S02 to the ambient air.  It is


the purpose of COG desulfurization systems to reduce the amount of SO2 emitted


to the ambient air by the removal of sulfur compounds from COG prior to com-
                                                    •

bustion.


     COG principally consist of hydrogen and light hydrocarbons, as illustrated


in Table 1.  Depending upon its exact composition, which in turn depends upon


coal analysis and coke oven operation, COG has a heating value of 500-560


Btu/scf and an average molecular weight of about 10.  Very iirportantly it typi-


cally has a sulfur content of 250-600 gr H2S/100 dscf and 5-25 gr/dscf of total

-------
~ '-'.''
COKE
Component
Hydrogen ...
Methane
Nitrogen
Carbon Monoxide
Ethylene
Carbon Dioxide
Ethane
Oxygen
Hydrogen Sulfide
Benzene
Propylene
Propane
Acetylene
Naphthalene

Carbonyl Sulfide
Carbon Disulf ide
Hydrogen Cyanide
Argon
TABLE 1
OVEN GAS ANALYSIS
Range, %
55.83-59.69
24.28-26.94
4.52- 8.94
3.78- 5.24
2.01- 2.31
1.58- 2.02
0.68- 0.82
0.38- 0.87
0.38- 0.59
0.01- 0.19
0.12- 0.17
0.06-0.12
^0.04- 0.10 ''';-•
0.00- 0.02
\ ' .'.'*'..
.0.006
0.0009 ,
• 0.008- 0.12 ,
- traces
•••.'•-'- . - ' *'

Mean, %
57.69
25.40
6.67
4.25
2.16
1.72
0.76
0.59
0.43
0.11
: 0.14
0.08 .
O.08
0.01

0.006
/ 0.0009
0.10
traces
2

-------
organic sulfur (the sum of RSH, COS, & CS-).  One useful rule of thumb is that



the H2S concentration in COG, expressed in gr/100 dscf, is approximately 365 x %S



in coal   .  The volume of COG produced in the coking process is in the range


                                           (2)
10,000 - 13,000 scf per ton of coal charged   , again ranging with initial



coal volatility and coking practice.  Therefore, a coke battery producing



500,000 tons of coke per year  (e.g., a four meter tall, 77 oven battery) will



produce about 8.6 billion scf of COG annually.  S02 emissions are in direct



proportion to COG consumption.  When burned by itself, uncontrolled, coke-



oven gas will produce 5.7 - 11.5 tons of SO2 per 1000 tons of coke pushed



at 250-500 gr H2S/100 dscf, respectively.   A 100 tpy SO2 emission rate



from COG combustion is equivalent to coking 8700 tons per year of coal



producing COG of 500 gr H2S 100 dscf or 87,000 tons per year at 50 gr H2S/



100 dscf.  New coke production in excess of 100,000 tons/year will produce



more than 100 tpy SO2, even within the allowable level of all SIP's in the



United States.  Hence, even under the most stringent SIP, new coke battery



construction is subject to New Source Review IAER criteria in SO2 non-attain-



ment area.



     It should be understood that coke-oven gas is almost never consumed at



one point in a coke plant.  Where coke batteries are heated  (underfired) with



COG, typically, only 40-45% of total COG production is needed for this purpose.



Distribution to in-plant boilers, steel heating furnaces, open hearth furnaces,



COG flairs, and to out-of-plant consumers is the rule.  One average distribu-



tion for a major steel producer is shown in Figure 2.  Therefore, desulfuriza-



tion is effected at the point of generation by removal of H-S and organic



sulfur.  The existence of a distribution system for coke-oven gas poses a

-------
BY-PRODUCT
BOILERS
12%
_
BLAST
FURNACE

OPEN
HEARTH

SLAB HEATING
FURNACE
10%
  ELIZA
 BOILERS
   8%
SOUTH SIDE
 BOILERS
   3%
ANNEALING
GALVANIZING
  PI
BATTERY
  8%
                 J&L
            COKE-OVEN GAS
  P2
BATTERY
  8%
  P3N
BATTERY
  8%


_
"C" SOAKING
PITS
10%
                                         "D" SOAKING
                                           PITS
                                            6%
                                  10" BAR
                                   MILL
                                    3%
                                           14" BAR
                                            MILL
                                            2%
MISCELLANE-
  OUS
   3%
FIGURE!  1973-1974 COG DISTRIBUTION OF J&L
             PITTSBURGH  WORKS

-------
complex issue for the EPA regional engineer.  At each use point, SIP emissions



standards for SO- may exist.  An industrial boiler may be limited to 1.2 Ib



SCL/10  Btu; a soaking pit to 1000 ppm S02-  On an average basis then, it is



conceptually possible for SO2 emissions from COG combustion within an in-



tegated steel mill to comply with an existing SIP despite the non-existence


                                            (4)
of a direct COG regulation.  Dunlap & Massey    note that 500 gr H-S/lOO dscf



is approximately equivalent to a 1.3% S coal.  Upon combustion in a boiler



this fuel will produce about 2 Ib SO-/10  Btu; when burned in a reheat furnace



the waste gas stream will contain approximately 1000 ppm SCL.  However, since



all new coke-oven gas will be consumed, the Offset Policy applicability deter-



mination shall be made for the total gas volume itself.  Each end use stream,



of which an integrated mill may have dozens, is not to be separately considered



against the 100 tpy criterion.

-------
     STATE IMPLEaVENTATICN PLAN REQUIREMENTS FOR COKE-OVEN GAS DESULFURIZATION

     The SIP's for California, Kentucky, Pennsylvania, Ohio, New York, and
West Virginia require COG desulfurization.  Coke plants are also located  in
states which do not have SIP's for coke-oven gas.  These are Illinois, Indiana,
Alabama, Tennessee, Minnesota, Wisconsin, Colorado, Michigan, and Utah.   The
most stringent SIP standards are shown below:
                       COG
  TAIL GAS
       TOTAL
California
Pennsylvania
Kentucky
Lorain, Ohio
                  50 gr/100 scf(a)        500 ppm S02
                  10
                     (a)
2000 ppm SO-
                                                           50  gr/100  scf
                                                                        (b)
-V20-35 gr/100 scf
35 (b)
                                  (c)
      (a)  H2S
      (b)  Total Sulfur
      (c)  No regulation per se.  This is the equivalent total.

-------
     The Kentucky coke-oven gas SIP is apparently the most stringent in the



U.S.  However, it applies only to "Priority I" areas, which are defined by



the SIP as having  (S02) ambient levels in' excess of 0.04 ppm  (annual) and



0.17 ppm (24-hr).  The 2000 ppm process emission limit, when applied to acid



or Glaus plant tail gas implies a sulfur recovery efficiency of 95-98%, de-



pending upon process details.  The Kentucky SIP is equivalent to 20-35 gr



ELS/100 dscf of COG produced.  To comply with the Kentucky SIP all of the



liquid oxidation and absorption methods of Section II are available.  High



efficiency sulfur recovery is necessary to comply with this regulation if



liquid absorption is chosen.



     The Pennsylvania SIP regulates total sulfur, as H2S.  Hence, for an



organic sulfide level of 15-20 gr/100 scf, this regulation is as stringent



in overall allowable SCL as the Kentucky SIP.  But, the Pennsylvania rule



is more flexible in that only the total equivalent SO2 emission rate is



fixed.  The rule applies Commonwealth-wide.  The Ohio SIP for U.S. Steel,



Lorain requires certain process streams to the less than 35 gr "H2S"/100 dscf



overall, including tail gas emissions.  This regulation is about as stringent



as the Kentucky SIP.



     The California SIP is the most stringent with respect to tail gas emis-



sions, requiring 99.5% sulfur yield.  In fact, Kaiser Steel chose a liquid



oxidation-no tail gas process in order to comply with this rule.  The rule



allows 50 gr/100 scf of H2S in the COG and places no organic sulfide limit.

-------
Section II.    CONTROL TECHNOLOGY





     Each of the technologies for coke-oven gas desulfurization involves two



separate steps:   (1) the removal or stripping of H2S and related sulfur com-



pounds from the coke-oven gas and  (2) the recovery of the stripped compounds



as elemental sulfur, sulfuric acid, or ammonium sulfate.  Available systems



fall into two broad categories:  liquid absorption followed by Glaus or acid



plant sulfur recovery or liquid absorption plus liquid phase oxidation of re-



duced sulfur gases.  Altogether, there are at least six basic technologies



commercially available in the U.S. for removing reduced sulfur from coke-oven



gas as shown in Table 2.  In addition, there exist a number of technologies



for recovering this sulfur.  Improving the sulfur recovery from both Claus



plant tail gas  (via tail gas treatment) and sulfuric acid plants must be



considered as part of these desulfurization technologies.  These processes



are shown in Table 3.





     A.   LIQUID ABSORPTION TECHNOLOGIES





     1.   Vacuum Carbonate Process




     This process uses a solution of sodium carbonate to wash countercurrently



an upward rising flow of COG in an absorption tower.  The absorber removes H2S,



HCN, and C02 but not COS or CS2, from the coke-oven gas.  The rich solution is



then steam stripped in a second tower, called the actifier, which releases the



acid gases overhead and regenerates the lean absorbing solution.  In the Vacuum



Carbonate process the steam, stripping is accomplished under partial vacuum, in



order to lessen the steam demand.  The basic process flowsheet is shown in



Figure 2.
                                      8

-------
                    Table 2.   COKE OVEN GAS DESULFURIZATICN TECHNOLOGIES
STEP 1 - SULFUR REMDVAL
 STEP 2 - SULFUR RECOVERY
PRINCIPAL U.S. VENDORS
  Liquid Absorption

  Vacuum Carbonate
  Sulfiban

  Diamox

  Carl Still
-Glaus Process
 Sulfur Recovery
      or
 Sulfuric Acid Production

 Glaus, Acid or Stretford
Hoppers Co.
Applied Tech. Corp. (BS&B)

Mitsubishi Chemical Industries

Dravo Corp.
  Liquid Oxidation

  Stretford
  Takahax A,B
  Takahax C,D
 Elemental Sulfur
 Elemental Sulfur
 Ammonium Sulfate
Wilputte Corp.
Chemico and/or Nippon Steel

-------
                Table 3.  GLAUS PLANT TAIL GAS TREATMENT TECHNOLOGIES
                 SYSTEM CHEMISTRY
                                        VENDOR
SCOT
S and S02 hydrogenation,
amine absorption to con-
centrate H2S, feed to
Glaus inlet
Shell
IFF - 1       Catalytic conversion of
              H2S and SO2 to elemental
              sulfur
                                   Institute Francis Petrol
BEAVON
S, SO2 hydrogenation and
COS, CS2 hydrolysis to H2S,
Stretford sulfur recovery
R. M. Parsons
WELLMAN-LORD  Sulfite/bisulfite absorption
              and concentration of S02
                                   Davy Powergas
                                 10

-------
                                          STEAM JET EJECTORS
         CLEAN COG
         30grH2S/100SCF
                 NO. 1
              150 psig stm
             317.000 Ib/DAY
           NO. 2
         150 psig stm
        143,300 Ib./DAY
•••
I
>

•^

V
• y.
r (-

r\ C°N
f
4
                             VAPOR
                    c
   INTER   ^
CONDENSER
      ACID GAS TO
      TREATMENT
      55-70%H2S
      5-15% HCN
      15-18% CO?
      5% H2 ETC.
  AFTER
CONDENSER
 H2S ABSORBER   ACTIFIER

SOUR COG
500 gc H2S/100 SCF
60 gr HCN/100SCF
                                                 (5.7 gal/ton CCAL)
                                            (3.02 gal/ton
                                            COAL)
                                                                  17,200 gal/DAY
ABSORPTION SOLUTION
SLOWDOWN (QUANTITY
VARIABLE)
    TOTAL VACUUM JET   38'200 Q^I/DAY
    CONDENSER SLOWDOWN
    55.400 gal/DAY (CONTAINING
    HCH, H2S.CO2)
  FIGURE 2. PROCESS FLOWSHEET:  VACUUM CARBONATE PROCESS
            BASED ON 60 MILLION SCF/DAY COG AND 93 PERCENT
            SULFUR  COLLECTION EFFICIENCY (REFERENCE 18)
                                                          r\y

-------
 GAS
OUTLET
              H  GAS

              E3  ACID  GASES
              P  FOUL  SOLUTION

              Q  ACTIFIED  SOLUTION

              3  CONDENSATE5
              Q  FLUSHING  LIQUOR


                                                                                                                ACID GASES  T
                                                                                                               HCN REMOVAL St
ABSORBER   SOLUTION CIRCULATING
                                       ACTIFIER
   INTER
CONDENSER
  AFTER
CONDENSER
TANK SOLUTION FLASH SOL.
	 FRESH COOLER HEATER
PUMPING SOLUTION
IMS MIXING VAPOR
. TANK FLUSHING CONDENS
SOLUTION To'S.UPeh
-„.». — .. . IU rLAon /-s 	 : i_» a^,
g°OLER ' SOL. HEAT Copyright©
	 • 	 ; 	 1 EXCHANGER

__ : — ! .
CONDENSATE TANKS
IB
VAPOR KNOCK ,
OUT DRUM

Koppers Company, Inc. 1976

A
-.

— — _

.-_...


..,



.....
_,,.:.u-^:» -,..,
~ 	 1 —
wcm u> fuKu
l{~\ t s\ A
ID DO P
                                                      FIGURE 3.

-------
     Recently, the Kbppers Co. has proposed a two stage vacuum carbonate process



(Figure 3)  which is intended to produce still lower sweet gas levels of H_S.



Hoppers maintains that by a double stage H-S absorber (see Process Appendix)



bench scale levels of <_ 10 gr H2S/100 dscf have been achieved   .  Kbppers is



offering this technology to stay competitive in the COG desulfurization field.



     The single stage vacuum carbonate process is capable of reducing COG H-S



levels to 30-35 gr/100 dscf^ '  , independent of inlet concentration.  Hence,



foul gas concentrations of 500 gr/100 dscf will be desulfurized by 93%.  How-



ever, COG with H-S concentrations of 250 gr/100 dscf will be desulfurized only



86% to reach the 35 gr/100 scf level.  On the other end of the efficiency spec-



trum, U.S. Steel's Clairton Works produces one KLS stream containing 2000-4000



gr/100 scf and it is desulfurized ^ 97% by a Vacuum Carbonate plant   .  Due to



these unusually high H-S inlet levels, the driving force for H-S absorption at



this Clairton Works Vacuum Carbonate plant is correspondingly high.



     A number of vacuum carbonate plants, summarized in Table 4, have been



constructed over the years, and there is no doubt as to the H-S removal effi-



ciency or basic reliability of the technology.  A major concern for the Vacuum



Carbonate process has been HCN - caused corrosion in Claus sulfur recovery plants


                                                     (8)
used in conjunction with the Vacuum Carbonate process   .  Serious corrosion and



catalyst fouling at Burns Harbor and Wierton   caused major downtimes at each



facility.  It is generally recognized now that HCN must be removed from the



acid gas stream leaving the still prior to admittance to a Claus plant.  In



acid plants, however, conversion of H2S to sulfuric acid may not require HCN
                                        13

-------
                  Table 4.  VACUUM CARBONATE PLANTS
    PLANT

Bethlehem Steel

 . Burns Harbor
 . Lackawanna
 . Sparrows Point
 . Bethlehem
 . Johnstown
COKE OVEN GAS CAPACITY (MMSCFD)
          120
           50
           60
           X (down)
           X (down)
   SULFUR RECOVERY
Glaus Plant, HCN Destruct
Acid Plant
Acid Plant  (down now)*
None for V.C. Plant*
None for V.C. Plant*
National Steel

 . Wierton
          70
Claus Plant, HCN water
wash
U.S. Steel-Clairton

 . Keystone V.C.
 . No. 1 V.C.
          90
          60
Two Claus Plants, HCN
water washing
Inland Steel
          50
Claus, water wash for HCN
 There are or will be Sulfiban-Claus technology at these plants.
                                14

-------
removal because HCN combustion in acid plant converters is higher than in
                                          e
Glaus sulfur recovery plants.  (The first stage in the Glaus plant inten-

tionally only partially combusts incoming H_S to SCL so that combustion is

really occurring in an oxygen-lean environment.  Consequently, HCN will not

destruct in the Glaus burner.)  Section IIB discusses HCN removal techniques

in more detail.

     For the single stage Vacuum Carbonate process the best coke oven-gas

desulfurization produces a clean gas of 30 gr H-S per 100 dscf of COG pro-

duced.  No organic sulfur is removed.  See Section III for a discussion of

organic sulfur in COG.  Double absorption Vacuum Carbonate has been shown

capable of achieving as low as 10 gr H-S/100 dscf.


     2.   The Sulfiban Process


     This is a technology developed by Black, Sivalls & Bryson, Inc. and

Bethlehem Steel Corporation.  Sulfiban is sold by Applied Technology Corporation

 (ATC), a subsidiary of B.S.& B.

     As with Vacuum Carbonate, Sulfiban is a liquid absorption/steam stripping-

solution regeneration process.  It produces at the outlet of the still column

an acid gas rich stream containing H-S, reduced organic sulfur gases, CO2/

and HCN which must be treated in the same manner as the Vacuum Carbonate acid

gas stream.  Sulfiban employs an amine absorber solution (^ 15% monoethanol

amine, "MEA") for sulfur removal.  Its still column operates at atmospheric

pressure.

     Due to the formation of certain salts, Sulfiban employs a reclaimer for
                                     15

-------
distillation of a side stream of the MEA which is returned to the absorber for

                                                     (9)
salts recovery.  As described by Williams and Homberg   ,  the key variables in

the achievement of sweet gas H2S levels are still column and reboiler steam

rates, absorber solution temperature, and the liquid circulation rate.  Figure 4

taken from this reference illustrates the strong dependence on liquid circulation

rate of outlet H2S concentration.  It is true of all the liquid absorption pro-

cesses that the sweet gas H2S level is a variable; high lean solution acid gas

levels and low liquid circulation rates detract from the best achievable levels.

The control of these variables allows an operator to lower operating costs.

Therefore, continuous monitoring of sweet gas levels will be needed to insure

continual emissions performance.

     Sulfiban plants have been constructed at three locations in Pennsylvania

 (see Table 5 for details) with commitments at three other locations.  Each

of these facilities was brought on stream during 1975-1976, and then brought

down because of mechanical start-up problems.  These experiences are described

in an attachment  (see the Process Appendix from the vendor) and are summarized

here'10'.

Shenango Inc. - Neville Island, Allegheny County


     Purchase order in spring 1973 - Start-up in May 1975 with a spray tower
     absorber - Conversion to a packed tower absorber by December 1975 to de-
     crease outlet from 30 gr/100 scf to <10 gr/100 scf - Plant taken down in
     winter 1975-6 for winterizing, installation of recycling cooling water
     system aimed at increasing still column efficiency  (see letter), putting
     in epoxy lining in still  (HCN corrosion protection), and correcting for
     improper still column tray construction - Scheduled to be on-stream
     in February 1977.
                                        16

-------
OUTLET H2S LEVEL
   (gr/l6bscf)\
   45
   35:
   25
   15
    5
                200
250
300
350
400
                                MEA CIRCULATION RATE
                                        (gpm)
                                       INLET:  325-375 gr
                                                     105

                                               56 MM scf D
                                               75 - 80° F
                      FIG. 4 SULFJBAN PERFORMANCE BSC, BETH.i

-------
                           Table 5.   SULFIBAN PLANTS
    PLANT
COKE OVEN GAS CAPACITY
   SULFUR RECOVERY
Bethlehem Steel
(Bethlehem, PA.)
two, each 60 MMSCFD
3-Stage Glaus, HCN Destruct
Jones & Laughlin
  Steel
(Pittsburgh Works)
          90 MMSCFD
Single Contact Sulfuric Acid
Shenango Inc.
(Pittsburgh, PA.)
          32 MMSCFD
3-Stage Glaus, HCN Destruct
There are presently coitmitments for Sulfiban plants at Bethlehem Steel;
Johnstown  (two) and Lackawanna.
                                      18

-------
Bethlehem Steel - Bethlehem, PA.
     Started up in August 1975 and operated through March 1976 - Severe
     corrosion occurred in still column below a stainless-carbon steel
     weld  (the top 16' uses stainless) - Column was entirely replaced with
     stainless, lined and placed into service in May 1976 - Operated until
     September 1976 when a mechanical problem in the reboiler  (see Process
     Attachment for explanation of function) occurred - System now in service.


J & L Steel - Pittsburgh Works


     System began start-up in October 1975 was partially destroyed by an
     explosion during welding as the still column - It ran for eight days
     thereto - Relined, new packing, and scheduled for start-up in March
     1977 - Acid plant has not run as of December 31, 1976.


     Sulfiban absorption efficiencies have been measured at all three plants

as well as at a pilot plant run at Bethlehem's Lackawanna Works.  These data

are summarized in Figure 4 and Table 6.  The important distinction between

Sulf iban and other COG desulfurization systems is that the MEA solution removes

COS and CS2 as well H2S.

     The Sulfiban process has been demonstrated to produce 5 gr H«S per 100 dscf

of sweet COG and 2 gr of organic sulfur (as H2S) per 100 scf of COG^35'10^.


     3.   Carl Still Process


     This technology is based upon commercial absorption of H-S from coke-oven

gas, steam stripping of the acid gas, and sulfur recovery by Claus,  sulfuric

acid or Stretford processes.  It was developed by Firma Carl Still of

Recklinghausen, West Germany and is marketed in the U.S. by the Dravo

Corporation.   Two Still/bravo systems are or have been built in the U.S.
                                    19

-------
             Table 6.  SULFIBAN PERFORMANCE DATA
                               H2S*                     ORGANIC SULFUR*
    PLANT             INLET	OUTLET         INLET	OUTLET

 Bethlehem            325-375       5 (high MEA)        8          1.2
 (Bethlehem, PA.)                   40 (low  MEA)
 Jones & Laughlin     369-416       0.3 -  3          N.D.         N.D.
 (Pittsburgh, PA.)


 Shenango             536-606         8-13          N.D.        <100ppm
 (Pittsburgh, PA.)


*Units:  gr H2S/100 dscf
                                       20

-------
             Table 7.  STILL/DRAVO PLANTS IN THE UNITED STATES
    PLANT                    COG CAPACITY           SULFUR RECOVERY
Armco Steel                  60 MMSCFD          Single Contact Sulfuric Acid
(Middletown, Ohio)
Wheeling-Pittsburgh          90 MMSCFD        . Single Contact Sulfuric Acid
 (Follansbee, West Virginia)
 (1977 Start-up)


Armco Steel
 (Ashland, Kentucky)                  Proposed to EPA
                                     21

-------
(see Table 7) and apparently one other is being proposed.



     The process flow diagram is shown in Figure 5.  Since the process is



clearly described in the Still brochure (see Process Attachment) only these



additional comments are provided here.  NH~ is the absorbant:



     (1)  The process is selective for H-S; it does not remove organic sulfur.



     (2)  The principal attraction of this process is that it simultaneous-



          ly treats H2S in COG and NH3 waste waters.  No additional reagents



          are needed in this process, for example.  Hence new plants particu-



          larly may be designed for the Still process.



     (3)  The basic Still process has many variants.  The most important ones



          are that: (a) The Stretford process can be used to recover sulfur as



          can a Glaus plant.  An acid plant is a third option,  (b) the process



          allows for recovery of anhydrous ammonia.  While the latter is not



          of direct interest to the final COG H2S level/ it is useful for the



          EPA engineer to know that this material is a useful by-product.



     (4)  Since the Still process description mentions the "USS Phosam" pro-



          cess (ammonium phosphate scrubbing of COG with steam stripping to



          recover NH_ and to concentrate NH3 liquor for H2S stripping) for



          recovering anhydrous NH~, a brief description of this process is



          provided in the Process Appendix.  The Armco-Middletown plant uses



          Phosam.



          Dravo quotes a guaranteed level of 25 gr H2S/100 scf of COG    ,



          although Firma Carl Still asserts 10 gr/100 scf is possible ^  '.
                                         22

-------
N)
          COG.
        CS2
       ( COS
       y IMH3  i
       ( NapthJ
       ' HCN
                      • allNH3             |
                      • 10-50gr/100scf H2S I
                      • organic   sulfur     '
                      H2S
                      Abs.
                                                                                       H2S, HCN, acjd gases
                                                                                        CO2
                                                      Sweet COG
                                                      % HCIM
NH3
Abs.
—N


• f
Deacifier
•^



NH3
CO2
NH3
Still
,H
                                                                                                            flush,
                                                                                                            liquqt
                                            Steam'
                                                  liquor of
              J
                                                            NH3
                                                            H2S
                                                            CO2   !
                                           FIGURE 5. STILL-DRAVO PROCESS

-------
The distinction is one of economics not technology    .  The Armco and



Wheeling-Pittsburgh plants are designed to meet an overall 50 gr H-S/lOO scf



standard.




      (4)  Diamox Process




     Diamox is a Japanese developed process  (Mitsubishi Chemical Industires,



Ltd.).  It too is based upon NH3 absorption of H2S and liquid regeneration by



steam stripping in a still column.



     The MCI description in the Process Appendix contains the basic process


                                                                            (12)
flowsheet as well as a list of facilities at which the process is operating



     MCI published data show H-S levels in the sweetened COG of less than



10 gr/100 scf^   •.  MCI quotes a 97% removal efficiency for a 277 gr/100 scf



coke-oven gas    .  Since, as noted above, absorber efficiency is dependent



upon  inlet  (H2S) and various process variables, and since we do not have



the specifics for the MCI tests (yet) we can only state that Diamox is capable



of lOgr H2S/100 scf.



     Diamox will require Claus or acid plant recovery and the comments with



respect to these technologies for Sulfiban, Still and Vacuum Carbonate are



relevant for Diamox.




     B.   SULFUR RECOVERS TECHNOLOGIES





      1.   Claus Process for Sulfur Recovery for COG Desulfurization




     Claus plants operate on the H2S rich acid gas produced by the Vacuum



Carbonate, Still, Sulfiban, or Diamox absorbers to recovery molten elemental
                                      24

-------
sulfur.  The process is well known and is described in many articles



A recent EPA publication in support of the proposed refinery Glaus NSPS



is referenced for a description of Glaus technology    .  The principle



difference between Glaus plant operation on refinery or natural gas H-S



streams and coke-oven gas acid gas is the presence in the latter of HCN.



As stated previously, HCN has created severe Glaus plant corrosion pro-



blems at Wierton and Burns Harbor.  At present, for instance, the Wierton



Vacuum Carbonate plant is down due to this effect. Therefore, as previously



noted, prior to the acid gas entering the Glaus plant.



     Two techniques for HCN removal are in use in the U.S.  Cold water



washing has been employed by Koppers in the 1940's and is utilized by


                                       (14)
U.S. Steel today at the Clairton Works    .  Wierton is to install water



washing      .  HCN is removed from the gas stream in a tower which takes



advantage of the different aqueous solubilities of H2S and HCN.  HCN is



then stripped from water solution, along with a small amount of H2S



carry-over.  The stripped gases may then be incinerated or recombined with



the main clean COG stream.  If this latter step is proposed, the sweet



underfire COG may have a bit more H2S than that sampled at the absorber



outlet, due to this blending.



     A recent development of Bethlehem Steel is the catalytic "HCN destruct



reactor."  Williams and Homberg and Singleton and Homberg^  ' describe this



well in the attached articles and further description is not needed here.
                                        25

-------
Successful operation has been obtained at the pilot unit at Lackawanna     and



the full scale units of Shenango and Bethlehem.  Scheduled annual downtimes



of this catalyst unit are said by the vendor to be in the range 10 days - 2



weeks, which is a serious matter.  Parallel cyanide destruct units can avoid



this long a downtime by providing an alterate path for the acid gases during



catalyst replacement and maintenance periods.



     The Dravo Corp. proposes to deal with the Claus-HCN problem by cata-


                                                                      (18)
lytically decomposing the gas in the Glaus furnace.  According to Hallv   ,



Dravo's proposal is to completely convert HCN to N2 + H2 + CO.  This broad



concept has not yet successfully been implemented at Vacuum Carbonate - Glaus



installations.



     Claus plant sulfur yields determine the sulfur content of the Glaus



gas emission.  Typically, two thirds of sulfur entering the Claus plant



burner is recovered as elemental sulfur in the burner stage, with increas-



ingly lesser yields obtained in the subsequent catalytic recovery reactors.



As shown in Williams and Homberg, even with four catalytic stages a portion



of the incoming sulfur is emitted to the atmosphere as a tail gas. However,



practical Claus plant yields are closer to 96%^"  This was the stated design



target of Shenango and Bethlehem for average long term operation.  Yields



as high as 99 % are quoted for very carefully controlled Claus plant design



and operation, but such has yet to be achieved in stable operation     and



not for COG—derived H_S feeds.  Hence, for practical purposes, 4% of input



total reduced sulfur  (TRS) should be taken to be the lowest non-treated tail



gas performance attainable for standard Claus plants.  That is, at most 96%



of input sulfur should be considered recoverable as elemental sulfur.
                                    26

-------
     In terms of emissions, this is equivalent to 0.083 Ib. SO2 from the



Claus plant incinerator* per pound of sulfur recovered.  In terms of con-



centration, S02 is found in the range 5,000-20,000 ppm.  The exact concen-



tration is a function of the concentration of H_S in the Claus plant feed



and amount of fuel used by the incinerator.  For a plant recovering 95% of



input sulfur before the incinerator ,  for example, a requirement for 500 ppm



SO- in the Claus tail gas** requires an overall yield of 95% +-.Q QQQ (5%) = 99.7%,




     Claus tail gas emissions can be treated to reduce substantially the



amount of SCL that is emitted to the atmosphere.  Description of these



tail gas treatment processes and their performance levels are contained in



a standard support document recently published by EPA's QAQPS in support of



the Claus sulfur recovery plant proposed standard (F. R. October 4, 1976) for



petroleum refinery applications.  The reader is referred to this SSEIS     for



an exposition of details of system chemistry and application.



     Briefly, three of these processes are described in the following:




     (a)  SCOT  (Shell Claus Off-Gas Treatment)




     The Claus tail gas composition is SO-, H-S, and some S vapor.  SCOT



first hydrogenates this stream to H_S with H- from sweetened COG.  H2S is then



concentrated in an amine absorber/stripper system. (See the Process Appendix



for more details).  The concentrated H2S is then fed to the main COG



absorber or to the Claus plant inlet.  SCOT went on-stream at U.S. Steel,
 At close to optimal yield the tail gas to the incinerator consists of a 2:1

 ratio of H2S:SO2-  A small amount of S vapor also is contained in the incin-

 erator feed.  After combustion of course, SO2 is the dominant species.
**                                            (21)
  The California SIP requires this at present
                                       27

-------
Clairton in 1975.  Figure 6 shows the Clairton flowsheet relevant to SCOT;



note that Glaus yields increase from 95% to 99.9%.  EPA test data for SOOT



(see SSEIS) confirm this capability.




     (b)  Beavon Process




     The Beavon process also converts Glaus tail gas to H2S.  SO- is hydro-



genated, as per SCOT.  COS and CS- are catalytically hydrolyzed  (CS- + 2H_0 -»•



2H2S + C02; COS + H20 -»• H20 + C02).  H2S is then recovered in a Stretford



plant.   Beavon is a development of the Ralph M. Parsons Co., Los Angeles,



California.  Performance levels are discussed in the Claus plant SSEIS.




     (c)  Institute Francis Petrol  (IFP)




     Beavon and SCOT are commercially available reduction processes.  Other



tail gas treatment (TGT) processes, by IFP, are available.  TGT-1500 produces



a 1500 ppm total sulfur gas stream and is commercially available.  TGT-150



(150 ppm) has yet to be comnercially proven.  The reader is referred to the



SSEIS  -  - and to the Process Appendix to this document for process descriptions.



Note that reduction to 1500 ppm will provide an overall 99.2% recovery in the



example cited above.




     (d)  Wellman-Lord




     This is an oxidation process, well known in the FGD field.  Wellman-Lord



produces SO2 as an of f-gas by means of a sulf ite/bisulfite absorber-stripper



system.  The output from the W-L is an SO2 stream which can be either combined
                                         28

-------
to
  HCN
WASHER
                              OVENS
                        COG
                  PHOSAM AND
                   CRYOGENIC
                    PLANT
  KEYSTONE
  VACUUM
CARBONATE PANT
                              H2S
                            KEYSTONE
                           CLAUS PLANT
                                     CLEAN
                                     COG FOR
                                     UNDERFIRING
                                                         COG
NO. 1 VACUUM
 CARBONATE
   PLANT
                                                             H2S. HCN
                                     NO. 1 GLAUS
                                       PLANT
                                     H2S
                                    S02.H2S
                                   SCOT PLANT
          NO. 1
          HCN
         WASHER
                                                         TO
                                                         ATMOSPHERE
                                                         SO2

                                                        INCINERATOR
    FIGURE 6. U.S. STEEL, CLAIRTON WORKS FLOW SHEET

-------
with the sweetened COG* or recovered as H2S04 in an acid plant.
     Since an acid plant probably would not exist at a coke plant using Glaus
recovery, recycling of the S02 to the Glaus burner is another option.  In the
example of the footnote on this page, 2690 Ib S02/day would be available for
a Wellman-Lord tail gas system.  The main Glaus burner combusts one third of
incoming H-S to SO- to initiate the Glaus reaction.  In this example,
(26,890/3) X 2 = 17926 Ib SOVday are so produced.  The Wellman-Lord unit
would supply 15% of this need.
     Performance levels for Glaus tail gas treatment increase Glaus yields f
from 95%-96% to 99.5 %.  This performance level is documented in the above
referenced SSEIS.  The October 4, 1976 F.R. proposes this performance level
directly for new refinery-based Glaus plants.  This standard for reduction-based
tail gas treatment is 0.025%  (250 ppm) SO2 on a dry no-O2 basis.  This level,
implies a 99.9% yield for a straight Glaus/96% efficiency plant producing
tail gas ? with a concentration of 10,000 ppm. as explained above.
     In summary, for tail gas Glaus treatment,. EPA has found that technology
is  available to produce tail gases of less than 0.5%  of Glaus  sulfur input.
For example, assume that a 50mm scfd, 410 ?^n 2   .COG is desulfurized to
    ••   — '                              A f\f\    Ov^i.    /"   M M
10 gr H2S in the clean gas, producing (0 x 3°§]'Q  x   ) or 26,890 Ib
                                                 1Q
 S/day Glaus recovery.  At  95% yield,  25,545  Ib/d will be recovered,  leaving
 1345 Ib/day of sulfur as a tail gas.  This is equivalent to  (1345 x ^ x  7000)  .
 or 10 x 106 gr/day of H2S  equivalent.  Added to the sweet COG, this will  in-
 crease its equivalent H2S  concnetra£ion from 10 to 10+ (-- x  ,-^) = 30  gr  equiv-
 alent H2S/100 scf of COG produced.
                                       30

-------
     2.   Sulfuric Acid Recovery




     The major alternative for sulfur recovery is the production of sulfuric



acid.  Tables 4, 5, and 7 indicate this was the process used by Bethlehem Steel,



J & L, and Armco for Vacuum Carbonate, Sulfiban and Still stripping.



     The reader is referred to other descriptions of the basic contact acid


                             (22)
process and its capabilities.     The major point is that sulfuric acid pro-



duction involves a tail gas stream.  Single absorption, single contact acid


                                               (22)
plants easily produce a 97% recovery of inlet S    .  Only single absorption



has been purchased for COG applications and in fact the new J & L plant is



designed for 97% efficiency.  One vendor     noted that double contact plants



were not being marketed to the steel industry because of competitive forces



between liquid absorption and liquid oxidation technologies.



     However, the double contact, double absorption process is commercially



available for the production of sulfuric acid and offers significantly greater



yields and hence lower tail gas emissions of SO2.  EPA's NSPS, 4 Ib S0-/ton



acid, is equivalent to 99.7% sulfur recovery.  A process description of double



absorption is contained in the Process Appendix.  Approximately 35 such plants



exist in the U.S.(23)



     The key technical issue is whether this is attainable on H2S from COG.



Since no applications have occurred, the direct demonstration has yet to be



made.  However, the sole difference for an inlet H-S stream as compared to S



or SO- is that water is formed in combustion of the H2S to SO2-  This water



can be removed in a preliminary drying tower prior to contacting the SO-.



Alternatively, a "wetlf acid plant can be designed to accept this water as   ••"
                                      31

-------
is done for the production of acid from spent acid feeds which contain hydro-



carbons.  The technical availability of the double absorption process for coke


                                                                             (24)
plant feeds is not an issue for Monsanto, Allied Chemical and other designers



As compared to single absorption plants of the same size (the median American



coke plant will produce ^40 tpd acid) capital cost differentials are about



15%-20% or $2.5MMvs. $2.QMM).



     Emission rates from double absorption sulfuric acid recovery are at least



99.7% yield or 4 Ib SCL/ton of acid produced as compared to 97% for single



absorption.  Therefore, double absorption offers as effective a way of reducing



tail gas emissions as does Glaus plant tail gas treatment technology.  The



choice of method can be allowed to be one of plant economics and not limited



by the inherent emissions effectiveness of Claus + TGT vs. double absorption



acid recovery.  It is also quite clear that the lowest technically achievable



overall SO- emission rates will require one or the other process combination



for the liquid absorption processes.*




     C.   LIQUID OXIDATION PROCESSES




     These processes differ from the liquid absorption processes described



above in that once H-S is absorbed, it is oxidized to sulfur or ammonium sulfate



in the liquid phase.  The separate Claus or sulfuric acid steps are avoided and



therefore no tail gas problem need be faced.  On the other hand, a difficult
 It is noted that Firma Coal Still suggests that recovery via Stretford

 is an option.  Stretford produces no tail gas.
                                      32

-------
liquid effluent problem is created in the form of thiosulfate and thiocynate



salts, which are not present in the liquid absorption processes to the same



degree.



     Two processes have been investigated by DSSE, the Stretford Process by



the North West Gas Board of the U.K. and the Takahax Process of Nippon Steel



Corp.  Two other processes, Fumax, a Japanese process, and Giammarco Vetrocoke,



a German process involving an arsenic solution, have not been studied due to



time pressures.  Basic process descriptions of the Stretford and Takahax



processes are provided in the Process Appendix.




     1.   Stretford Process




     The Stretford process produces elemental sulfur from HJ5 in COG.  It



does not remove organic sulfur.  At present, there is one application in



North America, located at the coke plant of Dominion Foundary & Steel Company



 (Dofasco) of Hamilton, Ontario  (42mm scfd).  Dofasco is building additional



coking capacity  (a new No. 6 Battery, 6m wet coal, by Didier) and has ordered



a second Stretford plant to handle the extra COG.



     The Stretford process absorbs H2S in a packed tower in a solution of



sodium carbonate, sodium ammonium vanadate, and ADA (anthraquinone disulfuric

                                                                              r,

acid).  The process flow diagram is shown in Figure 7.  In the absorber, HS


                                               +5     -f4
is oxidized to.S and vanadium is reduced from V   to V  .  The oxidizer


               +4                      +5
system allows V   to be reoxidized to V   by the reduction of ADA.  In turn,



ADA is reoxidized by air pumped into the oxidizer tank.  Elemental sulfur is



removed and the Stretford liquor is recirculated to the absorber.
                                      33

-------
PRODUCT
 GAS
 FEED
 GAS
       H2S ABSORBER
SULPHUR FOAM TO PURIFICATION
         PUMPING TANK
  FIGURE 7. STRETFORD PROCESS FLOW DIAGRAM

-------
     HCN in foul COG causes the formation of the thiosulfates and thiocyanates.



Therefore, removal of HCN ahead of the absorber or of its products in the absor-

                                                                             \

ber or removal of its products in Stretford liquor or both is necessary.  Re-



moval has been achieved ahead of the Stretford abosrber in an absorbing tower,



in which a solution of suspended sulfur and water reacts with the NH3 in COG



to form ammonium thiocyanate and thiosulfate.  This is known as the polysulfide



treatment process (due to the intermediate formation of ammonium polysulfide) .


                                                                     (25)
The polysulfide process can remove up to 98% of the HCN from foul COG



In turn, this liquor, containing SCN and S2O3 needs treatment before disposal.



These same compounds also build up in the Stretford liquor, if allowed, and



either spent Stretford liquor or a steady blowdown thereof require treatment



for these salts.



     Peabody-Holmes of the U.K. has developed and operate a Stretford process



waste liquor process  (Fixed Salts Recovery) at the Orgreave plant of British



Steel Corp  (26 MMSCFD of COG) .  The chemistry and other details of this process



are described in the Process Attachment.  The essential step is high temperature



oxidation in a reducing atmosphere, generated by substoichiometric combustion of



COG.  SCN and S203 are converted to H2S + CO2 + N2 and are recirculated to the



front end of the Stretford tower.  A critical question for the Stretford process



is whether the Peabody-Holmes waste liquor process is adequately demonstrated.
                                            26}
To this end Peabody offers the following   '   .   After laboratory and pilot



scale development, the Orgreave full scale unit was brought on-stream for oper-



ation and testing in August 1975.  The plant has operated continuously with two



exceptions for the past six months.  In August 1976 an "incident" involving a



COG explosion in a burner, not related to the basic process, brought the plant
                                       35

-------
down.  It had run for five weeks prior to then and ran from November 20



to Christmas 1976 when it was again brought down to provide a holiday



for BSC workers.  It will be operational in mid-January once more.  From



this, one sees that the process is considered a development by P-H and



BSC operators and that this project is proving successful from a system



chemistry perspective.  In an attachment, which is_ seen by_ EPA staff to



be quite confidential, Peabody-Holmes believes they have demonstrated



that their combustion process works.  In the August 5, 1976 in-house



memo, Peabody-Holmss noted that "steady-state" operation was still



needed at that time to fully prove the system's chemistry.  Two re-



cent judgements by the steel industry reflect the diversity of its



views.  Dofasco has ordered two Holmes' units; one for its existing



Stretford plant and one for the new Stretford plant mentioned above.  The



first Fixed Salt Recovery  (FSR) system is to be on-stream September 1977.


                              (27)
Kaiser Steel has just decided   ' to purchase Takahax based in part upon



the longer operating times Takahax has experienced.  Wilputte Corp., the



Peabody-Holmes licensee in the U.S. vigorously maintains the Holmes process



is commercially proven



     Wbodhall-Ducklam, a British engineering firm, has also piloted a Stretford



waste liquor facility based on the same basic chemistry as the Holmes process.



Wbodhall-Ducklain has not yet built a full scale unit although one is under


                                                        (28)
construction at the Redcar plant of British Steel Corp.     The reader is also



directed to the Nittetsu process  (see Takahax for an additional waste liquor



treatment alternative).



     The Stretford process is very efficient at removing H_S from COG.  Ludberg
                                   36

-------
quotes concentrations below 1 gr/100 dscf.  Wilputte asserts H2S to 10 ppm

                                     /25 26}
 (0.6 gr/100 dscf) is well achievablev  '    .  Massey and Dunlop state removal


efficiencies "in excess of 99%" are possible    .  Organic sulfur is not re-


moved, however.  Therefore, the lowest sulfur level emission rate for desul-


furization by the Stretford process is 1 gr H2S/100 dscf of COG produced plus


organic sulfur in the foul gas.



     2.   Takahax Process



     Takahax was developed and is sold by Nippon Steel Corp.  In the U.S.,


Nippon and Chemico Air Pollution Control Company  (of Envirotech) have a working


relationship for the marketing of Takahax.  Many details of the process chem-


istry are described in the Appendix and are not redescribed here.


     The basic flow diagram for Takahax is shown in Figure 8.  H^S is absorbed


from COG in a column, using either a Na or NH.,  based solution.  HCN is not re-


moved ahead of the absorber but is allowed to build up as thiocyanate in the


absorber.  A blowdown is removed for treatment  in one of three ways.


     The Nittetsu Chemical  (NICE) process, like the Holmes process, is based on


substoichemitric combustion of S-O., and SCN to  H2S, 002/ N2, and Na2C03  (in


liquid solution, returned to the absorber) H2S  produced from, the NICE process


can be either recycled to the absorber or sent  to a sulfuric acid plant.  Al-


ternatively, complete combustion of the ammonia waste liquor  ((NHJ S203 and


NH.SCN to S02 + C02, and thence SO2 to sulfuric acid) is possible.  Wet


oxidation at very high pressure and temperature to ammonium sulfate, for
the NH-j stripping of H-S version of Takahax, is a third waste liquor treatment


     bility(29).


     Since Takahax is available for each of these waste liquor options,  "Takahax"
possibility(29)
                                     37

-------
00
SWEET COG
FOUL COG
w<
1
1
1
1
1
1
A
DC
111
03
.DC' *•
0
(A
CQ
1
. . " - . \
WASTE LIQUOR
• '• ^
H2S RECYCLE
"WASTE AIR" STREAM
w AMMONIUM (NH4)2SO^4
* SULFATE PLANT *
TAIL GAS
t
S, SULFURIC _J
J ' ACID PLANT
ACID
^ TAIL GAS
1 1
. SUBMERGED H2? SULFURIC 1
r COMBUSTION T ACID PLANT
1
          FIGURE 8. TAKAHAX FLOW SHEET

-------
is a generic term.  Nippon Steel offers four process options.





     "A" - NEL absorption + wet oxidation of liquor to recover H2S in COG as



           ammonium sulfate.



           This version produces two "waste' air" streams containing a small



           amount of sulfur both of which need scrubbing before release to



           the atmosphere.



     "B" - NKL absorption + combustion of waste liquor, producing elemental



           sulfur and an SO2 stream from the waste liquor combustion process.



           This SO2 requires recovery as H2S04 with attendant considerations



           mentioned in Section IIC, above.  Again, a waste air stream from



           the absorber section carries some sulfur to the atmosphere.



 "C","D" - Na2CO2 absorption + NICE waste liquor treatment.  ELS is recovered



           as elemental sulfur.  The NICE process is used on ELS off-gas which



           Nippon Steel proposes as feed, along with molten sulfur, to an acid



           plant.  ELS could also be recycled to the absorber with sulfur the



           process output as well.  This latter version is termed the "D" type.





     Takahax is a conmerically demonstrated process.  Nine Japanese facilities



exist as shown in Table 8.  Kaiser Steel has decided to construct Takahax-A to



comply with an EPA-Kaiser consent decree and has so notified EPA Region IX.



Relative costs are shown in Table 9.



     Table 10 provides Takahax performance data     for four Nippon Steel



plants.  Note that the Nagoya and Yawata plants achieved 4 gr ELS/100 scf



whereas three other facilities were stated   ' to have been tested at
                                         39

-------
            Table 8.   COKE-OVEN GAS DESULFORIZATION UNITS IN JAPAN (JANUARY 1977 NIPPON STEEL)
                NAME
PLACE
GAS VOLUME    DESULFUKEZATION
SULFUR TREATMENT
Nippon Steel
Nippon Steel
Nippon Steel
Nippon Steel
Nippon Steel
Nippon Steel
Nippon Steel's
Affiliate
NKK
NKK
Kawasaki
Kawasaki
Kawasaki
Sumitomo
Sumitomo
Sumitomo
Mitsubishi Che.
Mitsubishi Che.
Mitsubishi Che.
Mitsubishi Min.
Amagasaki
Amagasaki
Amagasaki
Tokyo Gas
Hirohata*
Muroran*
Oita*
Nagoya
Nagoya
Tobata
Kimitsu*

Fukuyama*
Ogishima*
Chiba*
Mizushima
Mizushima*
Wakayama
Wakayama
Kashima
Sakaide*
Sakaide
Kurosaki
Hibikinada
Ohatna
Ogimachi
Kakogawa
Tsurumi*
99 MMSCFD
130
206
162
31
116*
227

116
90
80
179
90
70
107
72
215
188
85
107
53
47
132
45
NH-. - Takahax
NH^ - Takahax
NH^ - Takahax
Na - Takahax
Na - Takahax
Na - Takahax
NH-, - Fumax .
•3
NH3 - Takahax
NH3 - Takahax
NH3 - Fumax
Diamox
Diamox
Na - Takahax
NH3 - Fumax
NH3 - Fumax
Diamox
Diamox
Diamox
Bischoff, V.C.
Rodax, S tret ford
Rodax, Stretford
Rodax, Stretford
NH3 - Takahax
Hirohax
Hirohax
Hirohax
Combustion, Sulfuric Acid
Combustion, Sulfuric Acid
Combustion, Sulfuric Acid
Combustion, Sulfuric Acid

Combustion, Gypsum
Hirohax
Combustion, Sulfuric Acid
Glaus, IFF
Glaus, IFP

Combustion, Sulfuric Acid
Combustion, Gypsum
Glaus
Glaus, Activated Sludge
Glaus, Activated Sludge

Combustion, Sulfuric Acid
Activated Sludge
Combustion, Sulfuric Acid
Hirohax
Indicates facilities constructed in 1975 and 1976.

-------
                  Table 9.   RELATIVE TAKAHAX COSTS
             TYPE                     RELATIVE COST


          A (Hirohax)           100% - $12 million (1975)

          B                     110%

          C                     120%

          D                     130% (producing H-SOJ

          D                      90% (recycling H2S to absorber)
Notes
1.   Above data based on the Hirohata plant:  99M4SCFD
                                              200 gr H2S/100 scf inlet
                                               10 gr H^S/lOO scf outlet

2.   Includes cost of duel absorption sulfuric acid plant
                                   41

-------
                    Table 10.    TAKAHAX PERFORMANCE DATA
PLANT
Hirohata
Oita
MDroram
Nagoya
Yawata
H0S^a' INLET
200
260
240
300
340
H0S(a) OOUTLET(b)
I10
<10
I10
1 4
1 4
START-UP
DATE
4/75
6/76
3/76
10/73
3/74
DAYS SINCE
START-UP
630
204
306
1126
1036
DAYS IN
OPERATION
630
204
306
1111
1036
(a)  By J.I.S.  methodology,  gr H?S/100 scf.



(b)  No organic sulfide removal in the Takahax process.
                                     42

-------
<_ 10 gr/100 scf.  Nippon Steel states this to be a reflection of local pre-



fecture regulations and not system capability.



     The NH.,-Takahax process also produces a waste air stream which contains



small amounts of H2S gas.  The Takahax liquor is pumped to a liquid/gas



separation bubble tower into which air is pumped.  Waste liquor and regen-



erated solution (reoxidized) are separated and a waste air stream containing



H-S gas is created.  This stream is scrubbed in a counter-current packed



tower to remove its NH_ content with "mother liquor" (3-4% H2S04).  H_S in



the waste stream is of course not absorbed by this acid liquor and is



emitted to the atmosphere.  Exactly the same process chemistry gives rise



to the Hirohax waste stream.



     Pertinent data for these streams are shown in Table 11.  Note that the



quantity of H2S to the atmosphere is very small, < 0.01 gr/100 scf of COG.



As H2S is noticeable even at small concentrations in the ambient air, short



term diffusion model calculations were run to calculate these streams' impact.



For the 99 MMSCFD sized plant from which Table 11 derives, worst case 1-hr



concentrations were ^ 0.0015 ppm or about 40 times below the  (H2S) human order



threshold.
                                  43

-------
            Table 11.   TAKAHAX WASTE AIR STREAM FLOWS
                                                 ft3 H-S   Equivalent gr H-S
                       Outlet (H2S)    Volums    Per Day   per 100 dscf of OOG


Takahax Regenerator      2.3 ppn     2.7 - 3.2  6.2 - 7.4     .0042 - .0050
                                     MMSCFD

Hirohax Waste Liquor     2.0 ppm    .'.2.0 - 2.9  4.0 - 5.8     .0027 - .0039
  Process
                       Stack Parameters

                       Tenperature - 120°F
                       Height      - 130 ft
                       Diameter    -  14 in
                       Velocity    - <30 fps
                                    44

-------
Section III.   ORGANIC SULFUR IN COKE-OVEN GAS
     Only one of the six desulfurization technologies removes COS and CS2 from



COG.  Yet both, coirpounds produce SO2 upon combustion by:
                    CS2 + 3 02 + 2S02 + CO2





and it is the emission of S02 that the technologies are designed to abate.





     Organic sulfur has not usually been analyzed with care by coke plant



operaters since H2S predominates the total sulfur level of foul COG.  However,



after H2S stripping, uncontrolled organic sulfur may amount to half or more



of the total sulfur load in the sweetened COG.  For example, typical foul



gas may contain 450 gr/100 scf H2S and 15 gr/100 scf CS2 + COS.  If H2S is re-



duced to 10 gr/100 scf then of the 25 gr/100 dscf of total reduced sulfur in the



sweet gas, 60% is COS or CS2.  If the stripped acid gas is processed in a 97%



acid plant, an ELS equivalent emission of 12 gr/100 scf will occur.  In this



case, organic sulfur  (O.S.) will still account for 40% of SO- emissions.
                                                            ^


     The best estimates we have for foul gas organic sulfur levels are in the



range 5-25gr H2S equivalent/lOOscf .   (By ELS equivalent or "ELS", it is meant



that COS or CS2 volume concentration in ppm is converted to the gravimetric



conentration, gr "ELSVlOO scf, by multiplying by .063).  No good empirical



or theoretical relationships exist between H2S and COS or CS2 levels nor



does there appear to be any relationship between sulfur (%) in coal and COS/CS2




levels in COG.  This seems to be the case, despite the ELS/%S relationship



quoted in Section I.  One obvious variable affecting (COS) formation is 0~



in COG induced by stage charging.  This is an operating variable not subject



to predictions based on coal analysis.
                                     45

-------
     Empirical data for organic sulfur levels in actual. COG streams exist to

some extent.  The following data were obtained from various sources.




           Table 12.   ORGANIC SULF3DE CCNCENTRATICNS IN COG
         PLANT
FOUL COG ORGANIC SULFUR CONCENTRATION
1.   Jones & Laughlin
     -Pittsburgh Works
2.   Shenango Inc.

3.   Kaiser Steel
4.   Bethlehem Steel
     (Bethlehem, PA.)

5.   Republic Steel
a.  24 gr "H2S"/100 scf, total of CS2 + COs
    (Sulfiban design basis)
6.   Crucible Steel

7.   Bethlehem Steel

     a.   Sparrows Point
     b.   Lackawanna
     c.   Rosedale
     d.   Franklin
b.  5 gr "H-pS'VlOO scf - COS
    7 gr "HpVlOO scf - CS2   See Table 6

    25 gr/100 scf (Sulfiban design basis)

    19 gr/100 scf (recent gas analysis used
    for design)

    3-8 gr/100 scf total O.S. (Williams and
    Homberg)

    Have stated 10-20 gr/100 scf for design
    of facilities at Warren, Cleveland, and
    Youngstown.  This is a RSC generic
    estimate for total O.S.

    12 gr/100 dscf for COS + CS0
    14
    14
    10
    10
                                           46

-------
From this list 5-25 gr/100 scf seems to be a reasonable assumption for foul

gas O.S.  However, as coal sulfur levels and coking practices vary from place

to place and with time at any one location direct measurement is encouraged.

     Attached is an article by chemists of Jones & Laughlin Steel Corp. who

were faced with a foul COG sampling obligation in 1973    .  J & L had

designed a Sulfiban plant based upon a 400 gr H2S/100 dscf presumption.

Because their coal analyses indicated probable higher foul gas H2S sulfur

levels, the Allegheny County Health Department required J & L to develop

and operate a TRS* sampling system.  Data developed therefrom (see Appendix

for an example) can be obtained via Section 114 from J & L Steel Corp.
*     ,
 Total reduced sulfur,
                                        47

-------
Section IV.    PERFORMANCE LEVELS FOR COG DESULFURIZATION TECHNOLOGY






     In this section, are comparisons of the demonstrated technologies



described in Section II in terras of their ultimate overall so2 emission rates.



     Tables 13-15 indicate the H-S equivalent levels attained by liquid



absorption processes and their necessary sulfur recovery adjuncts.  Clearly,



the highest desulfurization currently achievable is by the high effeciency



Sulfiban process operated in conjunction with a high yield Claus or sulfuric



acid plant.  Also note:




     1.   Table 15 indicates the best demonstrated performance levels for



          other combinations of liquid absorption processes as well.  This



          table was calculated using a total organic sulfur concentration of



          15 gr HLS equivalent per 100 dscf.



     2.   Sweet coke-oven gas H2S levels of 10 gr/100 dscf of COG are



          obtainable by Diamox, Still, Sulfiban, and perhaps by double



          stage vacuum carbonate.  This only refers to the sweet gas, per se.



     3.   Only Sulfiban absorbs COS and CS2.  From Section III, it is clear



          that COS and CS2 can each exist in foul COG at levels from 10-25 gr



          H2S equivalent/100 dscf.   Sulfiban removes these down to a residual



          2 gr "H2S"/100 dscf level.



     4.   Standard Claus and single absorption sulfuric acid technology pro-



          duces a 96%-97% yield.



     5.   Claus + tail gas treatment or double absorption sulfuric acid



          produces a tail gas containing no more than 0.5% of the recovery



          plant inlet sulfur level.   (See Figure 9 for system options).
                                       48

-------
     6.   Overall system emissions can be reduced to [ (Foul COG Inlet



          "H2S" -5)(0.005 + 5] gr "H2S"/100 dscf of COG produced.  At



          500 gr "H2S"/100 dscf, this works out to an overall 9 gr "H2S"/



          100 dscf of COG.'  This is the overall lowest level demonstrated



          for liquid absorption.




     For the liquid oxidation process, Table 16 summarizes the analogous



performance levels.



     The impact of organic sulfur on the overall performance liquid oxidation



process is dramatic.  Basically, these technologies reduce SO~ emissions to



twice the foul gas organic sulfur gravimetric concentrations, when operated



at their maximum H2S absorption efficiencies.  This is so, because virtually



all H2S is removable.



     The overall capabilities of the coke oven gas desulfurization technol-



ogies discussed in this document are ranked in Table 17.  Two rankings are



provided, one for H2S and one for total reduced sulfur.  This table provides



a direct comparison of all the technology combinations studied in this



document's preparation.  Since their purpose is SO2 emissions prevention,



the right hand column of this table, in the units Ib SO2/10  ft  GOG, is



most useful.  In this table, the phrase "high S recovery" refers to 99.5%



sulfur recovery as shown in Table 14.
                                       49

-------
                   GAS
COKE
OVENS
              FOUL;
              GAS
ABSORBER

t/JjZ!
i.rf 1 uj !
o s:

H-

•.'••• :' . i



CLAUS
PROCESS
V
                                                    ACID GAS
                                                    H2S,HCN
                                                    C02
                SULFUR RECOVERY
                                                                              TOATMOSPHERt
                                                                    SINGLE

                                                                  ABSORPTION
                                                                   DOUBLE;

                                                                  ABSORPTION

                                                                                    I
                                                            SULFURIC ACID RECOVERY
                       FIGURE 9. LIQUID ABSORPTION OPTIONS  !

-------
Table 13.    SUMMARY OF LIQUID ABSORPTION TECHNOLOGY PERFORMANCE LEVELS
                    Best Attainable Outlet Sulfur Concentrations
  PROCESS


Sulfiban


Vacuum Carbonate


Diamox


Carl Still
    H2S


5 gr/100 scf


    30**


    10


    10
ORGANIC SULFUR
TOTAL REDUCED SULFUR
	(as H?S)
foul gas level*
    (PGL)
     FGL
     30 + PGL
                       10 + FDL
     10 + FGL
 Foul gas levels  (see Section III) are usually in the 5-25 gr/100 dscf range.
**
  Bench scale demonstration of 10 gr/100 scf has been made with a two stage
  vacuum carbonate process.
                                      51

-------
       Table 14.   SUMMARY OF SULFUR RECOVERS TECHNOLOGY PERFORMANCE LEVELS
   PROCESS
SULFUR YIELD (% OF INLET S RECOVERED)    TAIL GAS EMISSION RATE
Claus Process
.Three Stage
 Catalytic Re-
 covery

.With Tail Gas
 Treatment

Sulfuric Acid
  Plant
.Single Contact

.Double Absorption-
 Double Contact
                 96%


                99.5%



                 97%


                99.7%
                                         0.082 Ib S02 per Ib sulfur
                                         recovered.

                                         287 gr H2S equiv. per
                                         Ib S recovered.
0.010 Ib S02/lb S 35 gr
H_S equivalent/lb S

0.063 Ib S02/lb S 215 gr
ELS equiv./Ib S


0.0063 Ib S0-/lb S
22 gr H2S equiv./Ib S
                                           52

-------
       Table  15.  Best  Obtainable  Overall Desulfurization Performance
                        by  Liquid  Absorption Technology

                             Sulfur  Recovery Process
Three Stage
Removal Process Claus

Sulfiban

HeS / TRS**
300* 17* 19*
500* 25 27
Single Double
Contact Claus & Contact S tret-
Add TGT Acid Ford
H2S/TRS H2S/TRS H2S/TRS H2S/TRS
7 9 14 16 68 X
8 10 20 22 79 X
Vacuum Carbonate***


Diamox


Carl Still


300* 41 56
500* 49 64

300* 22 37
500* 30 45

300* 22 37
500* 30 45
31 46 38 53 31 46 X
32 47 44 59 31 46 X

12 27 19 34 11 26 X
13 28 25 40 12 27 X

12 27 19 34 11 26 10 25
13 28 25 40 12 27 10 25
  *Total  foul  gas  reduced sulfur concentrations, gr "^S" per 100 dscf of COG
   produced.
 **
   Total reduced sulfur.
***
   Single stage.
                                      53

-------
   Table 16.   BEST OBTAINABLE OVERALL DESULFURIZATION BY LIQUID OXIDATION
                            CLEAN COG CONCENTRATION                OVERALL
  PROCESS                   H2S	TRS*              H2S   TRS**

Stretford                    1                  16                1     16

Takahax - A                  4                  19                4     19
Takahax - B                  4                  19                6**   21
Takahax - C                  4                  19                6**   21
Takahax - D                  4                  19                6**   21
 Assumes 15 gr H-S equivalent/100 scf for organic sulfur in foul coke-oven gas.

**
  Assumes need for acid plant at 99.5% sulfur yield.
                                      54

-------
                     Table  17.   Technology for Desulfurization of Coke-Oven Gas
                          H2S   Ranking^)
                                         TRS   RANKING(a)
Technology
Stretford

Takahax - A
Tahahax - B,C,D
Sulfiban -
high S recovery
Still- Stretford
Still - high S
recovery
Diamox - high
S recovery
Sulfiban

Diamox
Still
Vacuum
Carbonate -
single stage
Clean
COG
1

4
4'
5

10
10

10

5

10
10
30


Tail Gas
0

0
2
2

0
2

2

15

15
15
14


Total H2S
Equivalent
1

4
6
7

10
12

12

20

25
25
44


Technology
Sulfi ban-high
sulfur recovery
Sulfiban
Stretford
Takahax A <

Takahax B,C,D
Still -
Stretford
Diamox -
high S recovery
Still - high
sulfur recovery
Di amox
Still
Vacuum
Carbonate -
single stage
Clean
COG
7

7
6-26
9-29

9-29
15-35

15-35

15-35

15-35
15-35
35-45


Tail
Gas
2 v

15
0
0

2
0

2

2

15
15
14


Total H2S
Equivalent
9

22
6-26
9-29

11-31
15-35

17-37

17-37

30-50
30-50
49-63


S02(b)
Emis-
sion
Rate
24

59
16- 70
24- 77

29- 83
41- 95

46-100

46-100

81-135
81-135
135-170


(a)  All  units  are  gr  H2S or equivalent



(b)  Unit is  Ib S02 emitted per 106 ft3
per 100 dscf of coke oven  gas  produced.



cf coke-oven gas produced.

-------
               COG DESULFURIZA1TON PERFORMANCE OCCLUSIONS







1.   The overall lowest achievable emission rate is achievable with the



     Sulf iban liquid absorption process operated at nigh MEA circulation



     and high MEA regeneration rates, followed by either double absorption



     sulfuric acid recovery or tail gas treated Glaus plant sulfur re-



     covery.  This level is 9 gr H2S per 100 dscf of coke-oven gas pro-



     duced with all tail gas included as equivalent H-S.  This level



     corresponds to an SO- emission rate of 25 Ib S02 per 10  ft  of



     coke-oven gas produced.



2.   The Stretford-Holmes or the Takahax processes may achieve this



     same or even lower rate of emission. Their lowest equivalent



     SO2 emission rates will vary from 16-83 Ib SO2 per 10  ft



     COG, depending upon foul gas organic sulfur levels.  Therefore,



     these two technologies may, at certain plants, be equivalent to



     the lowest achievable emission rate and may even surpass the rate



     stated in (1) above.  Foul gas organic sulfur levels must be less



     than 8 gr H?S equivalent per 100 dscf for this to be possible.



3.   When the foul gas organic sulfur concentration is between 9-13gr



     H2S equiv. per lOOdscf, the two liquid oxidation processes should



     be characterized as the second lowest emissive technologies.  This



     emission rate will be in the range 24-59 Ib SO2 per 10  ft  of COG.



4.   Above 13gr "H2S"/100dscf of organic sulfur, the second lowest



     achievable SO2 rate is provided by the Sulfiban process operated



     at high MEA circulation and regeneration rates, with sulfur recovery
                                   56

-------
     by a conventional Glaus plant or single contact sulfuric acid plant.



     This rate is an overall 22 gr "H2S"/100 dscf or 59 Ib SO2 per 106 ft3



     COG produced.



5.   Both the Firma Goal Still and Diamox processes can achieve 59 Ib S02



     per 10  ft  of COG provided organic sulfur levels are below 12 gr



     "HgS"/100 dscf.  Both processes require high efficiency sulfur



     recovery systems (Glaus + TGT, sulfuric acid).



6.   Diamox, Still, and Vacuum Carbonate operated with conventional sulfur



     recovery will not be able to achieve 59 Ib S02/10  ft  GOG because of



     the combined impact of organic sulfur and the high tail gas emission



     rate.



7.   Organic sulfide levels for the specific COG under consideration



     should be known.



8.   The recommended levels for various EPA regulatory policies are:




     (a)  Lowsst Achievable Emission Pate:  10 gr/100 dscf of COG



          produced of total sulfur compounds, expressed as H-S,



          including all tail gas sulfur emitted from sulfur re-



          covery equipment.



     (b)  Best Available Control Technology  (considering cost) for



          Prevention of Significant Deterioration use:  35 gr/100 dscf



          of COG produced of total sulfur compounds, expressed as H2S,



          including all tail gas sulfur emitted from sulfur recovery



          equipment.



     (c)  Reasonably Available Control Technology:  50 gr/100 dscf



          of COG produced of total sulfur compounds, expressed as
                                 57

-------
               H2S, including all tail gas sulfur emitted from sulfur re-
               covery equipment.

Section V.     MEASUREMENT FOR COMPLIANCE

     Since reductions in SO- emissions from COG combustion require removal
of H-S (and possibly organic sulfides) before combustion and since COG
combustion takes place at dozens of separate points/ the compliance measure-
ment is for reduced sulfur.
     As described in Section IV, it may be possible to achieve compliance
with the LAER by means of either liquid absorption or oxidation equipment.
Therefore it may be necessary to measure for:
     (1)   Cswg, concentration of sulfur compounds in the sweetened coke-oven
          gas.
     (2)   Ctg, concentration of sulfur compounds in Glaus, Takahax, or sulfuric
          acid tail gas streams.
     (3)   Vswg, volume flow rate of sweet COG.
     (4)   Vtg, volume flow rate of tail gas.
     (5)   Vfg, volume flow rate of foul COG.

     The lowest achievable emission rate standard can be written as:
                                m        *
          Cswg Vswg + 6.63 x 10   Ctg Vtg <_ 10 gr "H2S"	  	(1)
                         Vfg                   100 dscf of COG

     In this relationship the appropriate units are:
     [Cswg] = gr "H2S"/100 dscf
     [Vswg] = 100 dscf/hr
     [Ctg ] = ppmv
     [Vtg ] = dscf/hr (of tail gas)
     [Vfg ] = 100 dscf/hr
                                          59

-------
     Figure 10 is a schematic which indicates the various sampling locations

which potentially are needed to determine compliance.  The difference between

the cleaned and foul OOG volumetric flows is the amount of acid gas removed

in the absorber.  Since the sum of H2S, HCN, organic sulfides, and CO- is

typically about 1% of the foul gas flow, it is fair to assume Vswg«sVfg in

computing complinace.*  If Vswg is measured in lieu of Vfg this will bias

the computed result upwards by about 1%, in the converse case measurement

of Vfg will cause an underestimation of the true overall concnetration by

1% (tail gas flux/total flux  1/2%).

     Measurement of clean coke-oven gas flow by built-in orifice or venturi

flow meters can and should be expected to be part of an operator's process

control equipment.  Data should be reported to a 24-hour chart located in

the sulfur plant control room.  Such instrumentation has a tendency to drift

from calibration so that before using such equipment in a compliance test, it

should be known to be in calibration.  Even so, accuracy only to about + 5%

of the true flow should be expected  such flow meters tend to change dimension,

particularly on the foul gas side, due to tarry COG constituents.  Hence even

long term averaging will not necessarily  insure better accuracy.

     Clean coke-oven gas measurements of reduced sulfur compounds concentrations

must be sensitive to H2S, COS, and CS-.  There are two ways of accomplishing

this.  Direct measurement of each compound by gas chromotography  (GC) separation

followed by flame photometric or thermal conductivity detection has been
 Exception:  The Clairton Coke Works cryogenic plant or any other synthetic
 NH3 producer using H2 in COG.
                                           60

-------
                                        FIG 10  COMPLIANCE MONITORING LOCATIONS
CTl








COKE OVENS
V^rV^/jLvLJ V^ V 1-iL^ikJ

•












•
/
	 ^»














•
.
COAL
CHEMICALS

PLANT

















•^
(J
,














X^
i^..
"\

^









,-''~

0
g
P
0
a
. . a
V
•
3
-.








— -~,


if
1
J
j
3
V
-4 -



/?
/ ^
/




\x
\









r\
i^
^









*^^
^~



>-
"CLEAN








CLAUS

SULFURIC ACID

OR
r.TACT'C1 T ~mfY\D
WAolii JaiyUUK
. PLANT


\ •
COG












6
V:















x_
D"
u

1




















/








PS
8
s
f \
%




f
I"*



• S
/




•
\
1 . •


I
\
1
i
\ '




-


•r*
2)
\
.
•














                                   FOUL GAS FLOW
SWEET GAS FLOW
      AND
CONCENTRATION
TAII. GAS FLOW
    1 AND
CONCENTRATION

-------
successfully applied.  The reader is referred to Manka    .  The set-up



used by J & L included a permanent connection to the sweet gas line.



     The alternative is to acquire periodic gas samples which would then



be returned to a laboratory for GC separation and analysis.  This technique



carries the real risk that water condensation in the evacuated sample bottles



will occur, carrying H2S into solution and hence removal from the sample gas



phase.  See the Process Appendix for a discussion of this problem    .  In



the case of remote sampling and analysis, reheating the sample bottles before



hypodermic needle extraction of the gas sample will be necessary.  Reheating



may not completely solve such problems, however.  H-S and HOST may react with



NH., to form soluble salts which would thereby falsely remove H-S from the gas



phase.  For these reasons on-site GC analysis is preferred.



     The alternative to direct sampling of TRS is to combust the sweet gas



sample to CO- and SO?*  Measurement of SO2 concentrations then can be made



by EPA Methods 6 or 8.  This technique assumes complete conversion of all



reduced sulfur compounds to SO- and the lack of SO- formation.  EPA Methods



6 and 8 may therefore provide falsely low readings.



     Wet chemistry methods exist for H-S, COS, and CS- concentrations in



coke-oven gas.  These are the traditional methods employed by the industry



in routine sampling.  The most popular is the Tutweiler titration method



which can be used for either H-S or TRS.  While this method is useful at



foul gas concentrations, the method has been reported to be  less valid



at  (H2S) below 10 gr/100 dscf.  Patience in carrying out the titration



to the true end point has been indicated as one cause of poor detectability.
                                         62

-------
               (32)
with the method    .  Another range finding device used by the gas process-



ing industry is generally referred to as the "sniffer tube."  The only valid



use of these handheld devices is for quick order-of-nagnitude determinations.



     Tail gas sampling is necessitated in the case of the liquid absorption



processes for both concentration and flowrate, per Bq.  (1).  For Glaus



sulfur recovery plants, with or without tail gas treatment, EPA has pro-



posed tfethod 15  (F.R., October 6, 1976) for  (H2S),  (COS), &  (CS2) deter-



minations.  Sulfuric acid plant compliance testing in the formal NSPS is



by Method 6.  These methods are recommended for COG tail gas streams.



For Glaus plants, however, which pass the tail gas through an incinerator,



a problem particular to the COG occurs.  Since it is necessary to determine



the entire second term in the numerator of Bq.  (1), Vtg must be measured.



This was not necessary in the case of the refinery Glaus plant NSPS because



of the absence of parallel sulfur bearing streams.  The incinerator produces



a very hot  (^1500° F) stream which makes flow rate determinations, particularly



continuous determinations, difficult.  One company's solution     is to sample



for Vtg Ctg at the inlet to the incinerator with a venturi flow meter.  A dis-



advantage to be noted, however, is that the inlet to conventional Glaus plants



contain sulfur vapors in small amounts, which may condense in the Ctg or Cfg



sampling lines.



     Averaging time for compliance testing is another monitoring issue.  The



refinery sulfur recovery NSPS proposal requires a four hour testing period.



Each hour, four grab samples are to be acquired from a side stream which runs



to an on-site chromatograph.  One test comprises 16 grab samples.  The arith-



metic average of three tests is to be used to determine compliance.  For
                                     63

-------
              Table 18.   COKE-OVEN GAS SAMPLING FIELD SHEET
Plant
Battery No. (s)



Date
                            "4
Level = Cswg Vswg + 6.63 x 10  Ctg Vtg


                     Vswg
HOUR
1
Clock Time


2
Clock Time


3
Clock Time


4
Clock Time


Average
SAMPLE NO.
1
2
3
4
1
2
3
4
1
2
3
4
1
2
3
4

Cswg

















Vswg

















Ctg

















Vtg

















LEVEL*













•


Result
                                       64

-------
coke-oven gas flows are variable from minute to minute due to the inherent


batch operation of coke plants.  Since it is necessary to determine both


Cswg Vswg and Ctg Vtg to determine compliance, i± is_ imperative that Cswg,


Vswg, Ctg, and Vtg be determined simultaneously.


     The suggested monitoring scheme is outlined in Table 18.  Compliance


is determined by comparing the appropriate standard to the arithmetic average


of the 16 numbers in the right hand column.



Section VI.    ENERGY AND COST IMPACT OF COKE-OVEN GAS DESULFURIZATION


     A.   Cost Impact


     A general discussion of economics of coke-oven gas desulfurization


is very difficult to develop because of the large variability of specific


plant factors, the highly competitive and rapidly developing state of


technology, and the variability and uncertainty in by-product prices.


Each U.S. steel company which has installed or is committed to install


desulfurization technology (U.S. Steel, Bethlehem, Armco, J & L, Shenango,


Kaiser, Republic, Inland, Youngstown Sheet and Tube, and others) has of


course performed site specific cost studies.  These studies are limited


in their generality* and are not available to EPA.  Published cost studies


are limited either by scope or vintage.
*
 In one case a vendor was asked to provide in a bid 12 separate paramatiza-
 tions of the costs of the same basic process at a given site,-for a given
 COG.
                                    65

-------
     Recent cost studies considered in this guidance are:


       STUDY                                           SCOPE


Massey & Dunlap                           Hypothetical parametric case study
    .    ,q_4                              of Stretford and V.C. and Sulfiban
-sprang iy                                with conventional Glaus recovery.

Massey & Dunlap                           Hypothetical parametric case study
    .    1Q__(34)                          of Stretford plus waste liquor and
-spring iy/b                              and y>c^ Suifiban/ 3^ still ^^
                                          both conventional Glaus and single
                                          contact sulfuric acid recovery.

GCA - Spring 1976                         Vendor provided costs for plants of
     ft  ,,, (18)                          Republic Steel, Youngstown Sheet and
     runaea;                                       stretford     still & Sulfiban
                                          with Glaus and ' sulfuric acid recovery
                                          conventional.

                                          Done in support of Ohio SO- SIP.

EPA - July 1976                           Glaus plant tail gas treatment study
                                          for the refinery NSPS.


     From this table it is apparent that the two Japanese processes, Diamox

and Takahax, are not reported.  As well due to differences in design assump-

tions these studies are not readily comparable.  Nor is there one published

overall cost comparison particularly for the lowest achievable emission rate

technology paths:

     (1)  Sulfiban + Glaus + Tail Gas Treatment
     (2)  Sulfiban + Double Contact/Double Absorption Sulfuric Acid


     or in the case of <_ 8 gr/100 dscf organic sulfur in foul gas


     (3)  Stretford + Holmes Waste Liquor
     (4)  Takahax + Hirohax, Elemental Sulfur, or Sulfuric Acid Recovery
                                     66

-------
     Furthermore the representativeness (note, not the accuracy) of



the Massey/Dunlop case studies is uncertain because:  (1) they postulate



an inlet (H2S) of 500 grains, which is higher than the bulk of American



coke plants (according to the experience of the various EPA Regional



Enforcement Divisions and DSSE), and (2) competition in the U.S. is



much keener in 1977 because of the positive developments at the Holmes1



Orgreave project for Stretford, the three American Sulfiban plants and



the entrance of Takahax into the American market than when the Massey/



Dunlop studies of 1971-1975 were developed.



     One other difficulty in assessing the cost of achieving the LAER



level is the role of organic sulfides.  If a given coke-oven gas contains



less than 8 gr H2S equivaliet/100 dscf of COS and CS2/ then it is techno-  •



logially possible for both Stretford and Takahax to achieve the LAER level



This is not true of all coke-oven gases, however (see Section III and IV).



Prediction of organic sulfide concentrations is difficult.  For new coke



batteries, therefore, costing the technology to achieve LAER is difficult.



Extrapolation from existing batteries and coal blend data or from special



field tests of new coals in existing ovens is one possibility for lessening



such uncertainty.  However, the fact remains that the cost of achieving the



LAER level will be dependant upon the composition



     For all of these reasons the validity and representativeness of the



existing cost figures for coke-oven gas desulfurization are questionable.



Table 19, 20;.and 21 extracted from references  (18)  and (34) provide some



baseline cost data.  The reader is asked to study the specific references
                                    67

-------
                    Table 19.    COSTS  FOR COG DESULFURIZATION  SYSTEMS  AT  REPUBLIC  STEEL  - CLEVELAND  WORKS,  $10'
'' •
Opt til requirement '
Battery Haiti plant, Installed (Bl»)

Site preparation and otlUtU«,C 201 of BLP
Filed capital Investment (FCI)
Working capital, 20% of groat operating coat
Total capital Investment

Annual operating coat
labor* .
Administrative and general overhead, 601 of labor
Dtllttlea*
Hatarlali* .
Local taxet and Insurance, 2.7X of FCI
Groat operating coat
Sulfur by-product credit,' $40/ton
Het operating eott
Annuallted coit .
Anmiallted capital coat*
d h •
Federal Income tax '

Uet operating cost
Average annual coit

Average annual control coat, $/lh S removed'

RolBet-Slretford
Flint Ho. 1

7=450.0

1.490.0
8,940.0
295.0
9,235.0


210.0
126.0
'304-0
S96.0
241.4 •
1 ,477.4
• 233.4
1,244.0

940.7

165.0

1,244.0
2,349.7

0.180

Flant Ho. 2

5,400.0

1.080.0
6.480.0
181, B
6,661.8


173.1
103.9
186.2
• 270.9
,-m.tO.
909.1
- 95.4
813.7

Total

12,850.0 .
(12,100.0)°
2.S70.0
15,420.0
477.3
15,897.3 .
(15,147.3)*

383.1
229.9
490.1
866.9
416.3
2,386.5
• 328.8
2,057.7

678.5 1 1.619.2
' (1,S42.8)»
118.5

283.4 .
(270. 5)b
Sulflban
Flent Ho. 1

9,000.0

1.800.0
10.800.0
. 359.0
11.159.0


237.
142.
815.
307.
291.
'1.795.2
- 233.4
1,561.8

1,136.6

199.4

813.7 ; 2,057.7 1,561.8
1,610.7

3,960.3 : 2,897.8
(3,871.0) ;
0.302 0.215

(0.210)
0.222

Plant Ho. 2

4,900.0

980,0
5.880.0
195.9
6,075.9


164.1
98.5
396.4
161.8
158.8
979.6
^
Total

13,900.0

2.780.0
16,680.0
554.5
17.234,9

Dreva-Stlll
Flanf Ho. 1

8,400.0

1.680.0
10.080.0
276.6
10.356.6


402.0
241.2
1.212.2
469.0
450.4
2.774.8
^2JLJL
227.1
136.3
596.0
151.2
272.2
1.382.8
• »3-»
884.2 i 2.446.0; 1.149.4
1 •
1
618.8 1.755.4

108.6

884.2
1.611.6

0.302


1,054.8

308.0 i 184.1

Flent Ho. 2

5.600.0

1.120.0
Totll

14.000.0

2,800.0
6.720.0. j '16.800.0
170.9
6.890.9


176.7
106.0
289.7
100.8
181.4
854.6
- 95,4
759.2

701.9

122.2

447.5
17.247.)


403. •
242.3
885.8
252.0
453.6
2.237.4
233.4
2,004.0

1.756.7

306.3

2,446.0] 1,149.4 ; 759.2 2,004.0
4,509.4

0.245

2.388.3 ! 1.583.3 \ 4.067.0
i
0.183 0.296 '. 0.221 '



00
           vendor eitlaatei, Decenber 1975.  Each plant  It Independent, Including tulfut recovery.
           Vllpltle Corporation .offered a reduced price  If • contract vat awarded to provide both facilities tUultaneoutly.
           e$lte preparation, utility connection* to battery limit plant, and COG connection to battery Halt plant bated on CCA revlev of similar coatt reported  In
           the literature.
           Bated on Ctlllty Financing Method as codified by the Faxdiandle Eattern Flpelloe Company and detcrlbed  In Reference 42.
           *See Tablet  16 and i:.
           Conservative ettlsate bated on price ef $4&/long too received by SOUIO for by-product tulfer.                           '
           "Capital ccttt are cortlied bated on a discounted cash fleet of 8 percent over 20 yeera. •
           Average federal lacoce tax • 1.731 percent  of sun of totel capital resptrecent and working capital

-------
   Table  20.  COSTS  FOR 60  x 10   scfd  COG  DESULFURIZATION SYSTEMS
                 AT YS&T S103,  MAY  1976
•
Capital requirement
Battery limits plant Installed (BLP>*
Site preparation and utilities, 201 of BLP
Fixed capital Investment (TCI)
Working capital,6 201. of gross operating cost .
Total capital investment
Annual operating cost
Labor*1
Administrative and gene.al overhead;6 601 of labor
Utilities'1 '
Materials'*
Local taxes and insurance,6 2.7Z of PCI
Cross operating cost
Sulfur byproduct," credit $40/toa
Bet operating cost
Annual tzed cost
Annual ized capital cost
Federal income tax6*8
Net operating cost
Average annual cost
Average annual control cost, $/lb S removed
Holmes-Stratford
•
$7.500.0 •
1,500.0
9.000.0
219.2 ,
9.219.2

210.9
126.6
304.0
211.4
243.0
1,095.9
-233.6
862.3
939.0
163.4
862.3
1.964.7
0.150
Sulflban

10,000.0
2,000.0
12,000.0
326.7
12.326.7

253.9
153.6
. S95.4
304. £
324.0
1,633.7
-219.0
1,414.7
1,255.5
219.0
1,414.7
2,889.2
0.236
Dravo-Stlll

9,500.0
1.800.0
11,300.0
. 300.9
11,600.9

245.4
147.3
637.4
169.5
305.1
1,504.7
-219.0
1.285.7
1,181.6
206.0
1,285.7
2,673.3
0.218
"Manufacturer estimates, May  1976.

 Site preparation, cose to bring utilities to the battery limit plant, and connect raw COG ducts
to battery Holt plant based  on CCA review of similar costs reported in the literature.'

eBas«d on Utility Financing Method as modified by the Panhandle Eastern Pipeline Company and
described in Reference 18.

dSoo Tables 5 and 6.                                               •                   •••.''.

eConservatlbe estimate baaed  on price of $44/ton currently received by SOHIO for byproduct sulfur.

 Capital costs are amortized  at a discount cash flow rate of 8 percent over 20 years.   This method
yields an average annual capital cost, Including depreciation of 10.18 percent of total capital
Investment.

"Average federal Incoae tax • 1.731 percent of sum of total capital Investment and working capital.
                                              69

-------


«*.• ut-^'l
1 « J4--T
Basis
VACUUM CARBONATE
20HH5CFTr 60MH5CFD
Item
DesulfuHiatlon Plant
Cooling H20, gpro'')
Power, KUH/day
Chemicals, l/day'0'
Steam, f/hr
ActlHer and/or
Ejectors
Condensate Treatment
Total
Claus Sulfur Plant
Steam Credits, f/hr
High Pressure
• Low Pressure
Total
Net Desulf. + Sulfur
Plant Stm. demand, f/hr
_ j Sulfurlc Add Plant
0 Cooling H20. gpm(a>c)
Power. KUH/day

Steam Credit (600 pslg).
f/hr
Net System Manpower
Requirements •
(1) Operator, man/1
shift
(11) Chemist, hr/day
90tn .

1011
1579
177

5421

1120
6541


558
282
.840

5701

230
(1241)
.1560
(3139)
2220
(4321)


1

2
98*n

1314
2526
177

7179(b

1120
8299


607
J07
914

7385

250
(1564)
1699
(4225)
2417
(5882)


1

2
Win

3032
4737
530
I
' 16,263

3380
19.643


1674
,846
2520

17.123

690
(3722)
4440
(9177)
6670
(12.973)


1

2
98tn

3942
7579
530
it.
21.5371"

, 3380 .
24.917


1824
922
2746

22.171

751
(4693)
4835
(12,414)
7263
(17,654)


1

2
: Sbo'gYalns lUS/lOO SCF at linlet

fk
SULFIBAN
20HH5CFD
gntjt

S30
1300
300
\
' 5840

.
5840


558
282
840

5000

230
(760)
1560
(2860)
2220
(2780)


1

2
98In

1060
1300
300

10,914

.
10.914


607
307
914

10,000
*
250
(1310)
1699
(2999)
2417
(7583)


1

2
PLANT
F1RHA CARL STILL STRETFORD U/EFFLUENT TREATMENT
60HHSCFD
SPla

1590
4148
900

17,520

*
17.520


1674
846
2520

15,000

690
(2280)
4440
(8588)
6670
(8330)


1

2
98Xn

3180
4148
900

32,746

.
32,746


1824
_922
2746

30.000

751
(3931)
4835
(8983)
7263
(22,737)


1

2
2JWMSCFD
93tn

1400
4380(d
-

5500

•
5500


558
282
840

4660

230
(1630)
1560
(5940)
2220
(3280)


1

2
60HH5CFD 20HHSCFO
u 93«iL 99tn

4200 •xO
'•ll,220(dj 6000
N.A.

16,000

- . -
16,000 2200


1674
846
2520

13.480

690
(4890)
4440
(15,660)
6670
(9330)


11

2 2
60HM5CFQ
99ln

x!2
18,000
N.A.

-

-
6600


-
-
-

•

,

-
-


1

2
Footnotes;                                           .                                                                              •

(a)  Vacuum Carbonate ind  Sulflban plants use once-through Hver cooling water.  Flrma Carl Still plants employ eooUng  tower water.  Note that costs
     per thousand gallons  are different.


(b)  Approximately 16 percent of stated steam rate Is required to supply Incremental heat to the actlfler.

(c)  Figures In parentheses represent net requirements for a combination of desulfuHiatlon tnd sulfurlc add plants.


(d)  %?&&: iK^Tl^^                             """H™"'t' «» - -1thou* "'Hgeratlon unit ,r, 6000 .nd 2880 KUH/day


(«)  Na2C03 for the Vacuum Carbonate plant, aonoethanolamlne for the Sulflban plant.  Information not available (MA) for Stretford technology.

-------
for a statement of assumptions and methods.  To these data DSSE has added


new supplementary vendor cost estimates.


     In order to facilitate comparisons, Table 23 was prepared.  The


statistics of Tables 19-21 are adjusted in this comparison to place


all technologies on a before tax and by-product credit basis. Due to


the approximate year difference between the GCA and Dunlap/Massey estima-


tions, the reader may wish to raise Massey/Dunlap costs by about 10% - 15%.


     Amortized capitol plus operating costs are:  5.6 - 9.2<£/MCF for


Stretford, 6.3 - 10.8<£ MCF for Sulfiban, and 7.1 - 11.3$ MCF for Vacuum


Carbonate.  The Sulfiban capital cost estimate range  ($7.07 - 10 million)


appears to be confirmed by an independent estimate of Sulfiban's costs,


shown in Table 22.


     Tables 19-23 do not include the necessary cost of tail gas treatment


for achievement of an overall 10 gr "H-S"/100 dscf performance level by


the liquid absorption processes.  Nor do these tables show the differential


costs of operating a liquid absorption tower/still column at the lowest


clean COG H-S concentrations.   (Higher steam useage occurs at the lowest


ELS levels.)  Table 25 indicates the differential steam demand for Sulfiban


between 40 gr/100 scf and 5 gr/100 scf is about 7.9 MMBtu per ft3 COG.


Assuming $2.00/MMBtu* this works out to $506 per day or 1.58
-------
                Table 22.   RECENT (JANUARY 1977) VENDOR BID
1.   COG TO BE TREATED
     100,000,000 scfd
     250 gr/100 scf inlet H2S
      19 gr/100 scf inlet O.S.
     2.2 inlet CO2
      50 gr/100 dscf overall outlet
2.   DESIGN BASIS
     Sulfiban Plus Single Contact Sulfuric Acid
                           t
     In round figures:
      .$13 million total battery limits capital cost
      . $7 million - sulfiban
      . $6 million - acid plant

3=   (a)  This capital cost is equivalent to 13<£/scf (Dunlap and Massey(1975))
        -  7.8$/scf; GCAC (1976)
     (b)  The Sulfiban/acid plant ratio is 1.16 (Dunlap - 1.01)
                                   72

-------
Table 23.  COMPARISON OF COG DESULFURIZATICN COSTS
' • I 1 . ' •
COST
Capital ($M4)
Annuaiized Capital
($/day)
Annuaiized Operating
($/Day)
Net Amortized
Cost, Before
Taxes
.$/Day
(Before by-product
credit) .
Estimate Date
500 gr -»• 10 gr:COG
95% - CP; 97.5% Acid Plant
V.C. - DUNIAP
V.C. - Claus
2om
2.89
747
1220
L967
9.84

60MM
5.14
1329
2985
4304
7.14

V.C. - Acid
20MM
3.95
1021
1236
2257
11.29

60MM
7.54
950
2964
4914
8.19

500 gr -*• 10 gr: COG
98$ CP; 97.5% A.P.
SULFIBAN - DUNIAP
Acid
20M4
3.75
970
1407
3775
6.29

60MM
7.07
1828
3491
5319
8.87

Claus
20MM
2.69
698
1468
2116
10.83

60W
4.67
1208
3743
4951
8.25

SULFIBAN -^ GCA
: Claus
60MM - Operating
(70MM - Peak
10.0
2750
3586
6336
10.56

500 gr •* 10 gr
STRETFORD
Dunlap
60MM
.: 4.49
1161
2178
3339
5.57

GCA
60MM
7.5
2063
2337
4400
7.33

Wilputte
60MM
9.2
2493
2986
•
5479
9.16

. 1st Q.
First Quarter, 1975 Cost Estimates 5/76 1975 5/76 2/77

-------
        Table  24.   COMPARISON OF ALTERNATIVE  EMISSION CONTROL SYSTEM COSTS FOR A 10 LTD SULFUR PLANT
                                             (Cost Adjusted to June, 1975)
                                  Total  Costs
Differential  Over Preceding Case
Control System
Base Case
Alternative I
Alternative II
Oxidation
Reduction
Investment
($)
v$ 902,000
1,028 ,000 (a)
l,320,00o!a}
l,765,000(a)
Annual
Operating
Cost
($/.vr)
$133,600
198,60o(a)
352,200(a)
442,000(a)
Emission Rate
Total Sulfur
As SOg
(Lbs/hr)
93
19
2
2
Investment
($)
_
126,000
292,000
737,000
Annual
Operating
Cost
($/.vr)
-
65,200
153,400
243,200
Emission Rate
Total Sulfur Unit
As S02 Cost
(Lbs/hr) ' ($/ton)
18 .
74 21o(f>]
UOTAQ* '
£ l""/u1
17 3406^
Notes:
(a)  Includes costs  of base case  Claus sulfur recovery plant.
(b)  Incremental  costs per incremental ton  of S   recovered.

-------
Table 25.   ENERGY DEMANDS FOR COKE-OVEN GAS TECHNOLOGIES
SULFIBAN - GLAUS PROCESS
Source
X)G flow
(MMSCFD)
tet Process
Steam
(lb/day)
Power ,
(kwh/day)
Power
(Btu per
ft3 COG)
Steam
Energy.
Btu/ftJ)
Total
Energy
Demand
Btu/ft3)
Ib steam/
1000 ft3
Basis Inlet
(gr/
10? Outlet
set
Massey &
Dunlap
:- 60
20,000
4,148
0.72
13.2
13.9
12.0
500
10
GCA,
(Y.S.& T.)
60
672,000
10,920
1.91
12.3
14.2
11.2
464
25
GCA
(RSC-C#1)
65
700,000
13,200
1.31
11.8
13.1
10.8
461
25
GCA
(RSC-C#2)
33
308,000
8,880
2.83
11.8
14.6
9.3
381
25
ATC
32
211,300
3,600
1.18
2.3
8.5
6.6
475
40
ATC
32
447,000
3,000
0.98
15.4
16.4
14.0
475
5
STRETPORD
Massey &
Dunlap
60
158 ,,400
18,000
3.15
2.7
5.9
2.6
"500
5
GCA
Y.S.& T.)
60
68,900
29,760
5.21
1.3
6.5
1.2
464
10
Wilputte
60 -
34,300
21,900
3.84
0.63
4.47
0.6
500
10

-------
     The differential capital and operating costs for high sulfur recovery



for the liquid absorption systems with respect to conventional Glaus sulfur



recovery is shown in Table 24, which has been extracted from reference (13),



Page 8-12.  The 10 long tons/day example plant cited in Table 24 is the size



of a Glaus plant needed to recover sulfur from a 30 MMSCFD COG flow at 500 gr



H2S/100 scf.  This is exactly in the range of the discussion relevant to



Tables 19-22.  Table 24 indicates that the increased capital investment



(20 yr, 8%, straight line) for the reduction tail gas systems (e.g., SCOT)



is ^ 2.8* per MCF.  The amortized increase for tail gas treatment of Glaus



off-gas is ^ 3.6C/TV1CF or 33% over the baseline Sulfiban-Claus system of



Table 23.  This last estimate, however, overstates the differential cost of



tail gas technology.  Once in place, TGT equipment allows for a less effi-



cient Glaus system since its tail gas is then being cleaned.  In fact, this



is the process selection made for the Clariton coke works at which the two



Glaus plants are only capable of ^ 92% yield.  The SCOT TGT system improves



this to 99.9% yield.





     B.   Energy Impact




     The energy demands of COG desulfurizative technologies capable of



meeting the lowest achievable S02 emission rate are shown in Table 25.



Both electrical energy and process steam demands are considered.  Elec-



trical energy is rated at 10,500 input Btu per kwh.  Steam is assumed



to require 1100 Btu/lb.
                                       76

-------
      Table 26.   RELATIVE ENERGY DEMAND OF COG DESULFURIZATICN TECHNOLOGY
(COG FLOW - 20 MMSCFD)
                                     COG ENERGY DEMAND
                       Stretford           Sulfiban(a)          Sulfiban(b)
COG Heat Content     (5-10 gr) H2S**	(40 gr) TRS*	(10 gr) TRS



16,500 MMBtu           180 MMBtu/day            255                 504
        Day            1.1%                     1.6%                2.9%
     (a)  Conventional Glaus.


     (b)  With tail gas treatment.
*
 Percentage of COG heat content used as process steam or electricty.

**
  Refers to gr/100 dscf of overall sweet COG plus tail qas emission.  Add
  5-25 gr organic sulfide (as H2S) per 100 dscf to compare to Sulfiban.
                                      77

-------
     The range of total energy demands is 5-16 Btu/ft  COG processed.   Liquid
oxidation requires the least overall power because process steam demands are
lower than for the liquid absorption processes.  The energy cost per ft  COG
rises sharply as the absorption processes are operated at higher H2S removal
efficiencies.
     For example, to desulfurize to the lowest achieved level Sulfiban, 5 gr/
100 scf, an additional 8 Ib of steam per ft  of COG, a doubling from the
40 gr/100 scf level, is required.
     The energy demand for COG desulfurization is expressed as a fraction
of the energy content of COG produced in Table 26.  COG is assessed at
550 Btu/ft .  The energy demand, relative to the heat content of COG for
conventional moderate sulfur recovery efficiency H-S removal, and the
highest efficiency case are shown in this table.  An additional equiva-
lent 1.3% of available COG heat value is needed to achieve the LAER
value over the base case of an overall 40 gr "H2S"/100 dscf, if Sulfiban
is chosen.  Note that the Stretford process is able to produce a high
desulfurization efficiency (at least for H0S) with lower energy re-
                                          &
quirements than for the Sulfiban process.
                                      78

-------
                              REFERENCES
1.   Ludberg, J.E. "Removal of Hydrogen Sulfide from Coke-Oven Gas by the
     Stretford Process," a paper delivered before the 1974 meeting of the
     Air Pollution Control Association, Denver, 1974.

2.   Wilson and Wells, Coal, Coke and Coal Chemicals, first edition,
     McGraw-Hill, 1950, p. 240.

3.   Pennsylvania Department of Environmental Resources Rules and
     Regulations.  Title 25, Chapter 123.23.

4.   Dunlap, R. W. and M. J. Massey, JAPCA 25(10) 1019-1027 (1975).

5.   Stated during a discussion with Frank Vedja of the Koppers Co.,
     in Pittsburgh, PA. on December 1976.

6.   Massey, M. J., "Comments on the Technology and Economies of Coke-
     Oven Gas Desulfurization," a 1971 working paper of the Allegheny
     County Air Pollution Control Advisory Committee, 301 39th Street,
     Pittsburgh,. PA.

7.   This information derives from the Installation Permit application
     of U.S. Steel Corporation before the Allegheny County Health
     Department, 1972.

8.   Homberg, O.A. and Singleton, A. H., JAPCA 25(4) 375-378 (1975).

9.   Williams, J. A. and Homberg, 0. A., "Coke-Oven Gas Desulfurization
     and Sulfur Recovery Utilizing the Sulfiban Process," a paper pre-
     sented to the 34th Iron making conference of the A.I.M.E., St. Louis,
     MO., March 1976.

10.  Letter from Len Schuster, Applied Technology Corp. to Bernard Bloom,
     U.S Environmental Protection Agency, December 23, 1976.

11.  Acquired from discussions with J. Gordon Price, Dravo Corporation in
     October and December 1976.

12.  "Diamox Process for Coke-Oven Gas Clean-Up," Mitsubishi Kakoki
     Kaisha, Ltd., July 8, 1975.

13.  "Standard Support and Environmental Impact Statement Volume : Proposed
     Standards of Performance for Petroleum Refinery Sulfur Recovery Plants",
     U.S, EPA  (450/2-76-016a), September 1976.
                                      79

-------
14.  Massey and Dunlap, Op. Cit.

15.  "Process Desciption of Koppers Two Stage Hot Vacuum Carbonate
     System," Koppers Company, Inc., 1976.

16.  Homberg, Op. Cit.

17.  Acquired from a discussion with Marcus Peters, Applied Technology
     Corporation on December 27 and 27 1976, and January 16, 1977.

18.  "Evaluation of the Technological Feasibility, and Cost of Selected
     Control Alteratives Necessary to Meet the Proposed Ohio S02 Regulations
     for Industrial Boilers and Processes", Volume III, GCA Corp., June 1976,
     (A contractor report to EPA).

19.  Op. Cit., reference 4.

20.  Berlie, E. M., et. al., "The Role of the Claus Sulfur Recovery Process
     in Minimizing Air Pollution", a paper presented at the 1974 meeting
     of the Air Pollution Control Association, Denver, 1974.

21.  California Air Pollution Control Regulations  (South Coast APCD).

22.  "Control of Air Pollution from Sulfuric Acid Plants", a draft written
     by the U.S. Environmental Protection Agency for internal distribution,
     August 1971.

23.  Acquired from discussions with Donald Pogue of the Monsanto Corp.,
     December 1976.

24.  Letter from Donald Pogue to Bernard Bloom, January 10, 1977.

25.  Information provided by Frank Smith of Peabody-Holmes in a telephone
     call to Bernard Bloom on January 4, 1977.

26.  Information acquired from Walter Carbone, Wilputte Corp., in a
     telephone call with Bernard Bloom, January 4, 1977.

27.  Telephone call between Bernard Bloom and Harold Tauscher, Hellinger
     Engineering Corp., (and assigned to Kaiser Steel Corp.), January 5, 1977.

28.  Telephone call between John Hemingway, Vfocdhall-Duckham  (Pittsburgh, PA.),
     and Bernard Bloom on January 5, 1977.

29.  "Technical Bulletin for Coke-Oven Gas Desulfurization Equipment," Nippon
     Steel Corporation, Plant and Machinery Division, No. PMD 23, APril 1976.

30.  Manka, D. P., "Coke-Oven Gas Analysis," Instrumentation Technology,
     February 1975, p. 45.
                                     80

-------
31.  Letter from Janes R. Zwikl (Shenango) to Ronald J. Chlebaski; Allegheny
     County Health Department, May 31, 1974.

32.  Letters of Earl F. Young, Jr. (J & L Steel) to the Allegheny County
     Health Department, August 31, 1973 and May 20, 1974.

33.  Ibid. Young.

34.  Massey, M. and Dunlap, R. W., "Assessment of the Technologies for the
     Desulfurization of Coke-Cven Gas," presented to the 34th Ironmaking
   •  Conference of the AIME, Toronto, April 1975.

35.  Data obtained from a meeting with representatives of Nippon Steel
     Corporation, January 27, 1977, New York, NY.

36.  Batterton, G. and Singleton, A., "Coke-Oven Gas Desulfurization by
     the Sulfiban Process", presented to the 34th Ironmaking Conference
     of the AIME, Toronto, April 1975.
                                         81

-------
Appendix A -r .-VENDORS' OF COG TECHNOLOGY
     PROCESS
Vacuum Carbonate
            VENDORS

Frank Vedja
Kbppers Co.
Coke Plant Project Department
Engineerings & Contraction Division
Chamber of Commerce Building
Pittsburgh, PA.  15219
 (412) 391-3300
Carl Still
J. Gordon Price
Dravo Corp.
1 Oliver Plaza
Pittsburgh, PA.
(412) 566-3264
                                                 15272
Sulfiban
Mark Peters
Applied Technology Corp.
4242 Southwest Freeway
Houston, TX.  77072
(713) 626-8000
Diamox
Mitsubishi Chemical Ind., Ltd.
277 Park Avenue
New York, NY.
(212) 922-3771
Takahax
Mr. Yamasaki
Nippon Steel Corp.
345 Park Avenue
New York, New York
(212) 486-7150
Stretford
Walter Carbone
12 Floral Park Avenue
Murray Hill, NJ.
(201) 464-5900
                                    82

-------
Appendix A - VENDORS OF COG TECHNOLOGY ( cont'd)
   PROCESS                                   VENDORS

Sulfuric Acid                            Don Pogue
                                         Enviro Chem Division
                                         Lindberg Road
                                         Monsanto Chemical
                                         St. Louis, Missouri
                                      83

-------
       APPI5,
        :  r,
 J,(
00
     //*.'.tfS-V^^  /^/,/  xU/w  ;/Ty.-- vy^^//  :^;V-r^^v!.^A^

 t'ii?- -:-:--'MJ₯ij£*''-: ^i^^^                        ~^:
/*,
             -   **
               bat-
                     . 77..
                      7f
                      .77
                                 /Jf
                                            3'r
                                                3,*
                                            Vo

                                                          .Pi-f

                                                          77, o

-------