Gasification of coal impregnated with catalyst during pulverization: effect of catalyst type and reactant gas on the gasification of Shin-Yubari coal

Abstract

Shin-Yubari coal was impregnated with several catalysts of different chemical types during pulverization. The resultant system was more homogeneous and reactive than systems prepared by impregnation of coarse coal. The relative activities of the catalysts were determined as a function of gasification temperature, catalyst loading and gasifying agent. The activity sequence in steam was K ⪢ Ba ⪢ Ni ⪢ Fe ⪢ coal ash. Each catalyst had a unique reaction profile. For example, using steam the specific rate or the rate per remaining fixed-carbon weight decreased with time for the iron-catalysed reaction, whereas it increased for the potassium-catalysed reaction. A similar order of activity was observed in carbon dioxide, but a different sequence was noted for the hydrogenation reaction. Transition metal catalysts were the most active. The hydrogenation reaction profiles were different from the oxidation profiles.