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 ------- |