Pyrolysis and Devolatilization of Low-Rank Coals: Final Report, April 11, 1983-June 30, 1986

摘要

The effects of pyrolysis conditions and coal type on the nature of water-soluble organic effluents have been investigated using a small pyrolysis reactor system and a variety of atmospheres and pressures. The reactor is capable of a maximum heating rate of 45 deg C/min and a maximum furnace temperature of 1100 deg C. Variables examined include: (1) particle size, (2) maximum temperature, (3) time at temperature, (4) heating rate, (5) pressure, and (6) effect of atmosphere. Comparisons were made between the yields of water-soluble organic effluents produced from pyrolysis of coal samples under two different atmospheres and those obtained from Great Plains Gasification Plant gas liquor condensate. Results indicated that it may be possible to predict the gas liquor composition of a particular coal in a moving burden or ''fixed bed'' gasifier, such as a Lurgi dry ash gasifier, system. Four different lithologic layers have been identified in the Freedom Mine which supplies the lignite for the Great Plains Gasification plant in Beulah, North Dakota. The layers were identified on the basis of readily observable megascopic characteristics including luster, fracture characteristics and the presence of clay and silt zones. Lignite sampled from each of the four layers has been pyrolyzed in a bench-scale reactor system designed to simulate the production of gas liquor condensate from the pyrolysis of an actual gasifier. The yields of water-soluble organic effluents from each of the layers were found to differ significantly, particularly the yields of phenol, cresol, and catechol. Thus, by selective mining and/or blending of coal from different layers, gasifier performance may be improved. 7 refs., 5 figs., 12 tabs. (ERA citation 12:006396)