Effect of maceral composition and vitrinite reflectance on the combustion behavior of six hvA bituminous coals

The experimental results indicate that the six hvA bituminous coals studied displayed different behavior during combustion. This was attributed to differences in maceral composition and rank as measured by vitrinite reflectance. Vitrinite-rich and liptinite-rich coals lost more weight than inertinite-rich coals under similar experimental conditions. No significant differences in weight loss were observed between vitrinite-rich and liptinite-rich coals. A lower weight loss rate is believed to be characteristic of high inertinite contents. This is probably due to the existence of high aromaticity and strong cross linkages which exist within the inertinite macerals. For coals with similar maceral compositions, although the weight loss decreased with increasing vitrinite reflectance, there was not a direct and simple correlation between the weight loss and vitrinite reflectance. Although some smaller particles showed higher weight loss than larger particles of the same coal under similar experimental conditions, there was not a general relationship between the weight loss and the initial particle size. While the weight loss by the less reactive coals (inertinite-rich coals) was sensitive to particle size, the weight loss by the reactive coals (vitrinite-rich coals) was independent of particle size. In summary, for the high volatile bituminous coals, rank as measured by mean maximummore » vitrinite reflectance and maceral composition must be considered together with ASTM rank when predicting combustion behavior.« less