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EVALUATION OF THE FLASH DESULFURIZATION PROCESS FOR COAL CLEANING
Citation:
Fleming, D. AND R. Smith. EVALUATION OF THE FLASH DESULFURIZATION PROCESS FOR COAL CLEANING. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/7-79/016 (NTIS PB292328), 1979.
Description:
The report gives results of a program to develop (on the laboratory, bench, and pilot scale) operating conditions for key steps in the 'flash' process for desulfurizing coal by chemical and thermal treatment. Laboratory and bench scale data on high-sulfur eastern U.S. coals prove that the process can reduce sulfur to the point that the resulting solid fossil fuel can be directly consumed in compliance with current regulations for SOx emissions. Because of operating and technical difficulties, pilot scale test data are inconclusive. A preliminary analysis of a conceptual process indicates that the treated fuel would cost $1.50 to 1.75/million Btu (in 1977 dollars on a utility financing basis) if the initial coal cost is $1.00/million Btu. Four eastern U.S. coals, from abundant seams, were treated under various reducing-gas atmospheres at elevated temperatures. Sufficient sulfur was removed from all coals tested at ambient pressure and at temperatures of 1500 F and residence times of 60 minutes. These data were obtained in laboratory, fixed-bed, continuous weighing reactors and bench-scale fluidized-bed systems. As conceived, the process incorporated a 'sulfur-getter'--a material (e.g., lime) that has a greater chemical affinity for the sulfur than the coal has. Use of a sulfur-getter is required to reduce the H2S concentration in the gas. Data indicate that the concept is sound.