CHARACTERIZATION OF COAL CHAR GASIFICATION RATE

The transient kinetic technique was applied to the evaluation of both elemental rate constants, k(av) and k(in), and the amount of reactive carbons, n(w), which participate in gasification. The dynamic change in gasification rate with increasing conversion is due to the change in n(w). Differences in the gasification rates of ten different chars can be explained mostly by the differences in n(w), rather than by those of k(av) or k(in). n(w) increased and approached a maximum value, N, with increasing partial pressure of carbon dioxide. The maximum value, N, related closely to the carbon structure of char, especially to the crystallite size of graphite.