PYROLYSIS OF WESTERN CANADIAN COALS IN A SPOUTED BED

Coal pyrolysis has been studied to determine conditions for maximum liquid yields from some Western Canadian coals. Gas, tar and char yields were determined for four coals in a 12. 8 cm dia. reactor. A characteristic temperature for maximum tar yield existed for each coal at a fixed feed rate and particle size. A steady increase in tar yield was found as the average coal particle size was reduced from 2. 28 to 0. 65 mm. Composition of gas, and ultimate analyses of tar and char are presented as a function of operating temperature. A simple first-order devolatilization model adequately describes the effects of coal feed rate, reaction time, and temperature on the yield of volatiles, but is insufficient to describe particle size effects.