Analysis of Volatile Products from the Slow Pyrolysis of Coal

摘要

The report gives results of a study of the evolution of volatile matter from coals of various rank during fixed-and fluid-bed pyrolysis. The pyrolyses were performed at temperatures ranging from 400 to 1000 C and with heating rates ranging from 1.5 to 6.0 C/s. Effects of equilibrium temperature, heating rate, coal rank, and reactor design on weight loss, elemental volatilization, gas species production and product composition, and tar/gas production ratios were examined. Lignite, sub-bituminous, and bituminous coals exhibited the same weight loss versus temperature profiles at slow pyrolysis rates. Toluene, xylene, ethane, and total sulfur yields versus temperature varied from fixed-to fluid-bed conditions. All other compounds measured showed no such dependence on reactor design. For all systems studied, tar-to-gas ratios were lower (although overall weight losses were greater) for slow pyrolysis than for rapid pyrolysis. Tar yields increased and carbon oxide yields decreased with increasing coal rank.