EXPERIMENTALSTUDYON COALGASIFICATION INACIRCULATING FLUIDIZED BED

Experiment results on gasification of a bituminous coal in a pilot scale circulating fluidized bed at atmospheric pressure and different operation conditions, rates of coal feed from 5.4 to 8.14kg/h, ratios of steam/coal from 0.19 to 0.7kg/kg and ratios of air/coal from 2.8 to 3.67kg/kg, are reported. The effect of operation conditions on gas compositions, calorific values, carbon conversions and gasification efficiencies are analyzed. At present stage, the maximum calorific value of product gas was 3.84MJ/Nm3 and the highest coal conversion efficiency was 73.7%. Much carbon was lost in fly ash after the cyclone due to the short of the lift, the low gasification temperatures and the low separation efficiency of the cyclone for fine particles. Gasification temperature must be limited to 930℃ for Shenhua coal to avoid slagging.