KINETICS OF COAL OXIDATION

A series of seven coals of different ranks and from various locations were heated in air under relatively mild conditions to measure the rates of oxidation and the production of carbonic gases in the effluent stream. The gas flow rate, coal particle size, and reactor temperature were changed as independent variables. Each sample was exposed for from 6 to 9 hr under atmospheric pressure at temperatures in the range of 200° to 250°C. The results show two kinds of rate behavior depending primarily on the relative porosity of the coal under study. The small pore coals followed the expectations of the earlier Kam‐Hixson‐Perlmutter (KHP) model, but the large pore coals gave rates sensitive to transport effects. Correlations were also obtained on the ratio of carbon dioxide and carbon monoxide produced and on the relationship between the carbon content of an exposed coal and its heating value. Copyright © 1979 American Institute of Chemical Engineers