K2CO3-Catalyzed Steam Gasification of Indonesian Low-Rank Coal for H-2-Rich Gas Production in a Fixed Bed Reactor

摘要

K2CO3-catalyzed steam gasification of low-rank coal in a fixed bed reactor was investigated in order to elucidate the effects of temperature and catalyst loading amounts on hydrogen yield. The optimum conditions for H-2-rich syngas were 102.08gkg(-1) coal at 1073K with 20wt% K2CO3; the carbon conversion (X-C) reached 72.63wt% and the cold gas efficiency ((CGE)) reached 87.05%, simultaneously. However, at 1073K the tar yield was too small to be ignored. Through Brunauer-Emmett-Teller (BET), Barrett-Joyner-Halenda (BJH), t-plot, scanning electron microscopy (SEM), and X-ray diffraction (XRD) analyses of the gasification process, the surface area and micro-pore volume were found to reach a maximum value at 20min, while the average pore size reached a maximum value at 10min. X-C was promoted by the enlargement of average pore size and surface area, mainly caused by coal devolatilization. Potassium compounds tightly adhered to the surface and interpore sites of coal, capturing sulfur compounds to form K2SO4.