United States
Environmental Protection
Agency
Industrial Environmental Research
Laboratory
Research Triangle Park NC 27711
Research and Development
EPA-600/S7-83-044 Nov. 1983
Project Summary
Assessment of Discharges
from SASOL I Lurgi-Based
Coal Gasification Plant
S.J. Thomson, G. Kasper, J.F. Nagy, A. Tzou, and L.S. Pernot
Analytical information has been ob-
tained from SASOL I on the emission and
effluent streams analyzed in the normal
course of operation and testing. The
report consists of two sections:
• Phase I describes the plant and deals
with the specific emission and
effluent data from the gasification
section of the SASOL I plant, a
Lurgi-based indirect coal-to-liquids
facility.
• Phase II supplements the specific
data from Phase I with data based
on engineering estimates from
calculations and projections of
published and nonproprietary data
from other sources. This additional
data allowed closure of the material
balance on pollutants. Composi-
tions of some intermediate and
product streams were not included
because of their proprietary nature,
or because they were not considered
pertinent to this effort.
This Project Summary was developed
by EPA's Industrial Environmental
Research Laboratory, Research Triangle
Park. NC, to announce key findings of
the research project that is fully docu-
mented in a separate report of the same
title (see Project Report ordering
information at back).
Introduction
This report provided EPA with repre-
sentative emission and effluent informa-
tion on a commercial-size Lurgi-based
coal gasification project so that EPA
could better address environmental
aspects of Lurgi-based synfuels projects.
Process
SASOL provided representative data
on the emission and effluent streams
which were analyzed at the SASOL I
plant. In report Phase I, a block flow
diagram of the SASOL I facility indicated
the points in the process where analyses
and flow quantities were obtained
(Figure 1). Additionally, a plant description
further identified the sources of the
emission and effluent streams. Tables
listed the composition and flow quantities
of the streams analyzed.
During report Phase II, a block flow
diagram identified the points in the
process where analyses and flow quanti-
ties were obtained by testing and where
analyses and flow quantities were
determined by engineering estimates
(Figure 2). Engineering estimates closed
the material balance on the components
shown in the SASOL analyses of the
emission and effluent streams. A block flow
diagram indicated sulfur distribution
(Figure 3). Engineering estimates of
stream compositions and flow rates were
tabulated. Trace element distribution
tables were based on reference data and
a significant amount of engineering
judgement.
Conclusions
The final report presents SASOL I plant
operating data (Phase I) and supplemen-
tary data (Phase II), including material
balances and pollutant distribution
evaluations. Although much of this
supplementary information is based on
engineering estimates and calculations.
-------
(20
Tail Gas to Atm.
Rectisol Acid
(9)L Gas
I Wastewater
Phenols
_ Liquid Purge^~\
Sulfur
Recovery
Unit
Phenol Pitch
Sulfur
^—
W.
exception: its solubility in water and
resultant teachability from the ash may
require additional study. An unexpectedly
high water solubility of cadmium oxide
may be due to the presence of ammonium
salts in the water.
The data presented should be confirmed
by a series of test runs before they are
used for process design purposes, cost
estimates, or environmental control
studies. The data in this report may be
useful in designing a test program to
confirm and enhance the data presently
available.
Due to the low concentrations, sampling
and analytical problems, variations in
coal composition, and delayed response
time through the process, trace element
material balance closures (based on
analytical data from a commercial coal
gasification project) are of questionable
accuracy and reproducibility. Additional
extensive field testing to improve the
accuracy and consistency of trace element
results is likely to be expensive.
Figure 1. Block flow diagram of Sasol I gasification plant streams of major environmental
interest (Phase I).
it is believed to be representative of a SASOL
I gasification operation.
A comparison of various published data
sources revealed inconsistencies in
stream compositions and flow rates.
These discrepancies apparently result
from differences in feed coal compositions
and plant operating conditions used as
the basis for each publication. The
material balance estimates established
for this report are within the range of
values in other publications based on
similar feed and operating conditions.
The sulfur balance performed indicates
that about 89 percent of the sulfur in the
feed coal is in the gas streams, and 4
percent is in the liquid streams. Conven-
tional means (hydrodesulfurization and
sulfur recovery processes such as Stret-
ford treatment) can recover most of this
sulfur as a salable product, thereby
reducing sulfur emissions to the atmo-
sphere.
Most of the trace metals in the feed coal
remained in the ash and had a low
solubility in water. Arsenic was an
-------
Oxygen
Steam
Coal
Ash
High Pressure COz Vent Gas
Clean Gas
Tail Gas to Atm.
Sulfur
Figure 2. Block flow diagram of Sasol I gasification plant streams of major environmental
interest {Phase II).
S. J. Thomson, G. Kasper, J. F. Nagy. A. Tzou, and L S. Pernot are with Fluor
Engineers and Constructors. Inc., Irvine, CA 9273O.
William J. Rhodes is the EPA Project Officer (see below).
The complete report, entitled "Assessment of Discharges from Sasol I Lurgi-
Based Coal Gasification Plant," (Order No. PB 83-253 740; Cost: $8.50,
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
-------
Total Coal Lock Gas
&
Gasifier Gas
S=1930 kg/hr
(4256 Ib/hr)
(91.2%)
Gas Liquor
S=35 kg/hr (77 Ib/hr) (1.6%)
Start-Up Vent Gas"
S=2 kg/hr (4 Ib/hr) «0.1%)
•-71 kg/hr (157Ib/hr)
(3.4%) fa
Medium & Heavy Oils
S=27 kg/hr (60 Ib/hr) _
(1.3%) ^ Cooled Gas
S= 1859 kg/hr
(4099 Ib/hr)
(87.7%)
Dry Ash
S=150 kg/hr
(331 Ib/hr) (7.1%)
Gas Liquor Expansion
Gas S=4 kg/hr
(8 Ib/hr) (0.2%)
High Pressure
COx Vent Gas
S=22 kg/hr (49 Ib/hr) (1.0%)
Clean Gas S=NIL
Off Gas to Atm.
S=30 kg/hr (66 Ib/hr)
(1.4%)
HDSS=41 kg/hr
(90 Ib/hr) (1.9%)
Wastewater S= kg/hr (23 Ib/hr)
Acid Gas
S=1'796 kg/hr
(3960 Ib/hr)
(84.8%)
Notes:
"These values are primarily based on calculations and estimates.
"Average rate for start-up vent gas.
\PQduct
S=1'730 kg/hr
(3815 Ib/hr) (81.7%)
Figure 3. Sulfur balance and distribution for Sasol I gasification plant. *
ft US GOVERNMENT PRINTING OFFICE 1983-659-017/7213
United States
Environmental Protection
Agency
Center for Environmental Research
Information
Cincinnati OH 45268
Official Business
Penalty for Private Use $300
?SO S
DEARBORN S
IL 60004
------- |