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.

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             (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

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          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

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                                     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. *


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