x°/EPA
United States
Environmental Protection
Agency
Industrial Environmental
Laboratory
Research Triangle Park NC 27711
Research and Development
EPA-600/S7-81-009 July 1981
Project Summary
Environmental Assessment:
Source Test and Evaluation
Report Koppers-Totzek Process
C. A. Zee, J. F Clausen, K. W. Crawford
TRW, under contract to the Environ-
mental Protection Agency (EPA), is*
performing a comprehensive environ-
mental assessment of high-Btu gasifi-
cation and indirect liquefaction tech-
nologies. A major portion of this
environmental assessment project is
to obtain data on operating facilities
through Source Test and Evaluation
(STE) programs. The ultimate objective
of each STE program is to obtain the
data necessary to: 1) evaluate environ-
mental and health effects of waste
streams or streams that may potentially
be discharged from plants designed
for U.S. sites, and 2) allow subsequent
evaluation of the equipment available
or required for controlling these
streams.
This Project Summary was devel-
oped by EPA's Industrial Environmental
Research Laboratory, Research Tri-
angle Park, NC, to announce key find-
ings of the research project that is fully
documented in a separate report of the
same title (see Project Report ordering
information at back).
Introduction
An STE program was conducted by
TRW on a Koppers-Totzek (K-T) coal
gasifier. The EPA's interest in the K-T
process stems from two principal factors:
first, in the national drive to supplement
liquid and gaseous fossil fuels through
coal conversion, process economics
dictate that the more viable conversion
products will be those having the highest
unit retail value. The K-T process repre-
sents one of the prime candidates for
converting raw coal into the intermediate
synthesis gas needed to produce these
high-value products. Secondly, the K-T
process has a lengthy history of suc-
cessful application to a variety of foreign
coals and promises to be equally adapt-
able over the range of U.S. coals. This
factor is particularly important in view of
the contrasting lack of demonstrated
commercial reliability on the part of the
developmental U.S. gasifiers, and is
viewed in a very positive light by both
conversion project financiers and
program managers.
The K-T process operates on an en-
trained bed principle. It utilizes a high-
temperature (1400°-1600°C), atmos-
pheric-pressure reaction fueled by a
continuous co-current input stream of
coal, oxygen, and steam. The licensor-
developer of the Koppers-Totzek gasifi-
cation process is Krupp-Koppers GmbH
(K-K) of Essen, Federal Republic of
Germany. As of 1978 there were 54 K-T
gasification modules in the world of
which 47 were using coal as a feed
stock. All of the K-T gasifiers in operation
as of 1978 were used entirely to make
synthesis gas as an input stream for the
production of ammonia. The facility
selected for testing was the No. 4
Ammonia Plant at Modderfontein,
Republic of South Africa. The plant is
owned and operated by AECI, Ltd., and
has a design production rate of 1000
tonnes/day of ammonia. The plant was
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commissioned in 1974. The gasification
facility utilizes a bituminous, high vola-
tile B coal that is high in ash (20%), and
low in sulfur (1.0%).
Process
The Source Test and Evaluation (STE)
program was carried out as a joint effort
between TRW and K-K, the licensor and
developer of the K-T process. TRW's
initial review of the Modderfontein
plant, shown schematically in Figure 1,
resulted in the selection of 25 streams
as necessary to the comprehensive STE
goals. Of the 25 streams, summarized in
Table 1, nine were actually tested (i.e.,
streams 7, 15, 16, 32, 33, 38, 40, 46,
and 50). The selection of streams for
testing resulted from discussions
between K-K and TRW in which streams
considered proprietary or otherwise
restricted were eliminated from the list.
The STE thus became limited in scope
and focused on the remaining available
streams.
The on-site sampling and analysis
was performed by K-K. Their overall
effort spanned a 3-week period in
November 1979. The gas samples were
analyzed for the species H20, H2, CO,
C02, N2, CH«, H2S, COS, CS2, mercaptans,
S02, NH3, HCN, and NOx. Aqueous
samples were analyzed for the standard
wastewater tests (e.g., pH, alkalinity,
conductivity, BOD, COD, and anions)
with a few supplemental wastewater
tests also being performed by a local
commercial laboratory, McLachlan &
Lazar (pty), Ltd.
Wastewater samples were shipped to
TRW for comprehensive organic and
inorganic analyses per the EPA pro-
cedures for Level 1, Level 2, and Priority
Pollutants (1,2, 3). The Level 1 methods
provide a broad semi-quantitative survey
from which constituents found to be
present at potentially hazardous levels
are selected for further quantitative
examination (Level 2). The Priority Pol-
lutant screening consists of analyses for
a specific list of 129 pollutants of
concern to the EPA.
All of the data obtained from this STE
were used in the EPA's Source Analysis
Model/IA, which compares the mea-
sured concentrations of the constituents
analyzed to the EPA's Discharge Multi-
media Environmental Goals (4,5). This
model calculates discharge severities
based on the constituent concentrations
alone (total discharge severity, TDS) and
Table 1. Process Streams Requested for STE Program
Stream
No.*
Stream Description
6
7
9
12
15
16
17
19
20
26
21
22
23
24
25
28
34
33
32
35
38
40
48
46
50
Coal Bin Purge Gas
Coal Feed to Gasifier (tested)
Gasifier Slag
Gasifier Poke Hole Gas
Raw Product Gas (tested)
Input Water, Cooling Water (tested)
Compressed Raw Gas
Sulfur-Free Raw Gas
Compressed Sulfur-Free Gas
Spent Shift Catalyst
Shifted Product Gas
COz-Free Product Gas
Synthesis Gas
Compressed Synthesis Gas
Recycled Gas from Synthesis
Nitrogen Wash Tail Gas
COz Rich By-Product Gas
COz Stripper Tail Gas (tested)
Diluted Rectisol Condensate (tested)
HzS Rich By-Product Gas
H2S Re wash Column Tail Gas (tested)
Compressors Condensate (tested)
Cooling Tower Recycle Wash Water
Input Water, Purified Sewage Effluent (tested)
Settling Pond Discharge (tested)
* Stream numbers correspond to those shown on Figure 1.
on the concentrations combined with
the stream flowrate (weighted dis-
charge severity, WDS). This approach,
being used uniformly by all EPA con-
tractors in the coal conversion area,
provides a consistent basis for evalua-
ting STE data.
The results of utilizing the SAM/IA
approach with the data from the Mod-
derfontein Koppers-Totzek facility are
summarized in Figure 2. The two tail gas
streams are direct emissions at Mod-
derfontein. The discharge water is the
settling pond effluent. Results from the
input waters (purified sewage effluent
and cooling water) supplied to the
gasification facility are also provided for
comparison. The data from Modderfon-
tein indicate that the streams tested do
not appear to be of particular concern,
The discharge severity values obtained
are similar to or lower than those
obtained on similar streams from other
gasifiers (6,7). However, a conclusive
determination of health and ecological
effects or lack thereof can only be
obtained from a combination of chemical
and biological tests. Biological tests
were not included in this STE.
Note that the discharge severity'
values of concern result from relatively
few constitutents. The TDS and WDS for
the two tail gas streams are due primar-
ily to the CO and NHa concentrations.
The TDS and WDS for the aqueous
streams are due mainly to P and Mn
and, to a lesser extent, Fe, Cd, Cu, Ni, Pb,
and Zn. The reduction in both TDS and
WDS for the discharge versus the input
waters appears to be due to a decrease
in the concentrations of P, Cu, Pb, and
Zn. These appear to be lost to the set-
tling pond sludge.
Conclusions and
Recommendations
The limited source program conducted
at the Modderfontein facility has pro-
vided some of the key data needed for
the environmental assessment of Kop-
pers-Totzek based synthetic fuel plants
which may be built in the U.S. The data
obtained do not indicate that any special
problems should be encountered in con-
trolling the process effluents to environ-
mentally acceptable levels for plants
built in the U.S. Relatively steady state
conditions were realized during the test
period; thus, most of the samples taker
were generally representative of typ^
plant operation. This in turn indicates
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Health
Ecological
1E6
Purified Sewage Effluent
Cooling Water
Hz Rewash COz Stripper
Column Tail Gas
Tail Gas
Input
Water,
PSE*
Input
Water.
CW**
Discharge
Water
1EO
H2 Rewash
Column
Tail Gas
COz Stripper
Tail Gas
Input
Water,
PSE*
Input Discharge
Water, Water
CW**
Figure 2. Summary of SAM/IA results for Koppers-Totzek facility.
that the data can be used reliably, as
intended. One exception was the
Rectisol unit which apparently was not
operating properly at the time; hence,
data on Rectisol tail gas characteristics
are not believed to be typical.
Except for the Rectisol unit tail gases,
additional sampling of the streams
which were the subject of the initial test
program is not expected to yield infor-
mation other than of a confirmatory
nature. Hence only limited additional
sampling of these streams is suggested
in conjunction with aqueous stream
sampling as outlined below.
Several aqueous and solid waste
streams were not tested in the initial
program and data relating to their char-
icteristics would be helpful in the
avaluation of pollution control needs for
U.S. facilities. Table 2 identifies these
streams along with the type of data of
interest for each. As indicated in the
table, data are needed on the character-
istics of aqueous streams resulting from
raw gas cooling and paniculate
removal, from slag quenching and from
the cold water wash unit (HCN removal).
Of major concern are constituents in the
aqueous streams (e.g., NH3, HCN, H3N)
which may become volatilized in the
clarifier or cooling tower systems, and
result in atmospheric discharges. In
addition, characteristics of the gas
quenching wastewaters would indicate
the original crude gas composition,
which would be helpful in evaluation of
potential wastes generated by K-T
designs featuring other gas cooling/
particulate removal systems. To com-
plete constituent mass balances around
the gasifier/gas cooling systems,
repeat sampling of the raw gas (after the
blower) would be desirable so that a
consistent set of data is available.
Also indicated in Table 2 are solid
wastes/sludges generated by the slag
quenching operation and by the clarifier
unit. The primary concern with these
wastes is the leachability of specific
trace elements and other potentially
toxic substances. The leach test referred
to in the table is that specified in
regulations promulgated by the EPA
under the Resource Conservation and
Recovery Act of 1976 (RCRA). The RCRA
regulations are currently being revised;
the revision may result in changing the
leach test procedures. This type of data
would be used to indicate the disposal
requirements/methods for solid wastes
generated by facilities built in the U.S.
Note that additional sampling/testing
activities at the Modderfontein facility
would have as the primary goal that of
providing basic characterization data on
K-T generated wastes so that control
technology requirements for facilities
built in the U S. can be identified early in
the planning stages. It is not intended
that any data resulting from tests at
Modderfontein be used for the purpose
of either promoting or criticizing specific
process designs or operating practices
of that facility, which was designed in
1972 and which met the local environ-
mental regulations in force at that time
References
1. IERL-RTP Procedures Manual:
Level 1 Environmental Assess-
ment (Second Edition), EPA-
600/7-78-201 (NTIS PB 293 795),
October 1978.
2. Sampling and Analysis Proce-
dures for Screening of Industrial
Effluents for Priority Pollutants,
EPA/EMSL, Cincinnati, OH, Re-
vised April 1977.
3. EPA/IERL-RTP Procedures for
Level 2 Sampling and Analysis of
Organic Materials, EPA-600/7-
79-033 (NTIS PB 293 800),
February 1979.
4. SAM/IA: A Rapid Screening
Method for Environmental Assess-
ment of Fossil Energy Process
Effluents, EPA-600/7-78-01 5
(NTIS PB 277 088), February 1978.
5. Multimedia Environmental Goals
for Environmental Assessment,
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Raw Coal
Input
Water
!Electrostatic
^recipitation
Input £5
der-Stokeri4.Boiler
Boilers \*-<3Feed Water
(2) |4-'
'46 " Bottom 52
Ash Slurry
1 1!
174 I Feed to Nitrogen Wash L~-^C/a/-/y/er^-J
T 1 and CO2 Stripper r^
I61
S/i/dgre
h^
5^ Discharged
' Water '
7 Raw coal
2 Dry, milled coal
3 Coal fines
4 Recycled coal
conveying gas
5 Waste gas
6 Purge gas
7 Coal dust
8 Low pressure steam
from gasifier water
jacket
9 Hot slag
10 Quenched Gasifier
slag
11 Slag quenching 20
waste water
12 [unassigned] 21
13 Raw gas 22
14 Steam condensate/ 23
recycled boiler 24
feed water
15 Raw gas after 25
blower 26
16 Input water [CW] 27
17 Compressed raw gas 28
18 HCN free raw gas 29
19 Sulfur free product 30
gas 31
Compressed sulfur 32
free gas 33
Shifted product gas 34
COz.free product gas 35
NH3 synthesis feed gas 36
NHs synthesis feed 37
[compressed] 38
Recycle gas 39
Spent catalyst 40
Purge water 41
Nitrogen wash tail gas
Methanol
Recycle methanol 42
COz rich methanol
Diluted rectisol condensate 43
Tail gas
COz rich acid gas 44
Hz rich acid gas 45
Hz rich methanol 46
Hz rich methanol 47
Tail gas 48
HCN wash condensate 49
Compressors condensate 50
Electrostatic
precipitator 51
wash water 52
Water seal waste water 53
Figure 1. Schematic of Modderfontein Koppers-Totzek Coal Gasification Facility.
6.
Volumes I-IV, EPA-600/7-77-
136a/b (NTIS PB 276 919 and
PB 276 920), November 1977, and
EPA-600/7-79-176a/b (NTIS
PB 80-115 108andPB80-115116),
August 1979.
Environmental Assessment:
Source Test and Evaluation
Report—Chapman Low-Btu Gasi-
fication, EPA-600/7-78-202
(NTIS PB 289 940), October 1978.
7. Environmental Assessment:
Source Test and Evaluation
Report—Wellman-Galusha (Glen
Gery) Low Btu Gasification, EPA-
600/7-79-185 (NTIS PB 80-102
551), August 1979.
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HP Steam HP Steam
NH3
Synthesis
Gas
Spent t
Catalyst 26
HZS Rich
Acid Gas
C02
Stripper
wash
•r blowdown
°SE]
ent
;h/ water
'er solids
1 discharge
' sludge
lurry
ry coal
Liquid
N2 Wa
Liquid
Ammonia
Product
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Table 2. Additional Data Needs for Koppers-Totzek Process
Stream Constituents/Parameters
Stream Name No. ** of Interest
Uses of/Justification for
Additional Data
Coal Feed to Gasifier
Input Water (Purified
Sewage Effluent)
Input Water (Cooling
Water)
Washer Cooler
Slowdown
Disintegrator Slowdown
ESP Wash. Water
Raw Gas Compressors
Condensate
HCN Removal Wash
Slag Quench Slowdown
Clarifier Influent
Clarifier Effluent
Cooling Tower
Recycle Water
Quenched Gasifier Slag
Settled Clarifier
Solids/Clarifier
Underflow
Raw Gas after Blower
Raw Gas prior to Acid
Gas Cleanup and Shift
7
46
16
44
43
41
40
39
11
45
47
48
10
49
IS
18
Proximate/Ultimate, Trace elemental
survey.
Standard wastewater tests*. Trace element
survey. Organic compounds survey, priority
pollutants, level 2 as needed (POM's).
Standard wastewater tests*, Trace element
survey. Organic compounds survey, priority
pollutants. Level 2 as needed (POM's).
Standard wastewater tests*. Trace element
survey. Organic compound's survey. Level 2
as needed (POM's).
Standard wastewater tests*.
survey. Organic compounds
as needed (POM's).
Standard wastewater tests*.
survey. Organic compounds
as needed (POM's).
Standard wastewater tests*.
survey. Organic compounds
as needed (POM's).
Standard wastewater tests*.
survey. Organic compounds
as needed (POM's).
Standard wastewater tests*.
survey. Organic compounds
as needed (POM'S).
Trace element
survey. Level 2
To corroborate data collected from initial
STE.
To corroborate data collected from initial
STE and to provide background comparisons
for the aqueous process streams, t
To corroborate data collected from initial
STE and to provide background comparisons
for the aqueous process streams.^
To indicate those constituents of crude K-T
gas which are likely to be removed/
condensed with water in this or alternate
quench designs, t
Same as for Washer Cooler Slowdown.^
Trace element Same as for Washer Cooler Blowdown.-\
survey. Level 2
. Trace element
survey. Level 2
, Trace element
survey. Level 2
Trace element
survey. Level 2
Standard wastewater tests*. Trace element
survey. Organic compounds survey, priority
pollutants. Level 2 as needed (POM's).
Standard wastewater tests*. Trace element
survey. Organic compounds survey, priority
pollutants. Level 2 as needed (POM's).
Standard wastewater tests*. Trace element
survey. Organic compound survey, priority
pollutants. Level 2 as needed (POM's).
RCRA leach test for soluble elements/
substances which may be potentially toxic
(POM's).
RCRA leach test for soluble elements/
substances which may be potentially
toxic (POM's).
Flow rate, temperature, Hz. CO. COz, H2S.
COS, CSz, mercaptans, /VWs, HCN, methane,
higher hydrocarbons. POM's. paniculate
matter.
Flow rate, temperature. HI, CO, COz, HZS,
COS, CSz, mercaptans, NHa, HCN methane,
higher hydrocarbons, POM's, paniculate
matter, HzO.
To corroborate data collected from initial
STE and to allow constituent material
balances around gasification operations, t
To allow constituent material balances
around gasification operations.^
To indicate solids buildup and consequent
blowdown requirements in the slag cooling
circuit and to allow constituent material
balances around gasification operations, t
To allow constituent material balances
around gasification operations, t
To compare with clarifier influent in order
to indicate degree of removal of both
dissolved and suspended materials
expected during clarification and the
possible atmospheric emissions of vola-
tile substances, t
To indicate possible atmospheric emissions
of volatile substances in clarifier effluent and
to allow constituent material balances.
To indicate the likely disposal require-
ments for K- T solid wastes for facilities
constructed in the U. S. and to be able to
relate data to U.S. coa/s.t
To indicate the likely disposal require-
ments for K- T solid wastes for facilities
constructed in the U. S. t
To corroborate initial STE data and to allow
constituent material balances around
gasification operations.
To allow constituent material balances
around gasification operations.
* Standard wastewater tests include: Flow rate, temperature, hardness, conductivity, dissolved oxygen, pH, alkalinity, total sus-
pended solids, total dissolved solids, BOD, COD, TOC, NH3. SCN~, CN', CF, sulfur species, phosphorus species.
t Bioassay Tests. The future data base may have to include bioassay data to fully determine the requirements for
meeting U.S. environmental standards. Such tests would focus on final discharges (such as stream 10, above) and any
final aqueous effluents. However bioassay tests on selected in-process streams would have value because the resul-
tant larger data base would aid in correlating biological toxicity with chemical composition.
**Stream numbers correspond to those shown in Figure 1.
6
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C. A. Zee, J. F. Clausen, and K. W. Crawford are with TRW, Inc., One Space Park,
Redondo Beach, CA 90278.
William J. Rhodes is the EPA Project Officer (see below).
The complete report, entitled "Environmental Assessment: Source Test and
Evaluation Report, Koppers- Totzek Process," (Order No. PB 81-185613; Cost:
$9.50, subject to change) will be available only from:
National Technical Information Service
5285 Port Royal Road
Springfield, VA 22161
Telephone: 703-487-4650
The EPA Project Officer can be contacted at:
Industrial Environmental Research Laboratory
U.S. Environmental Protection Agency
Research Triangle Park. NC 27711
SW1 T97-01Z/7Z4I
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United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
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