HIGH TEMPERATURE COAL PARTIAL GASIFICATION OF O2/STEAM IN A FLUIDIZED BED

摘要

The air-steam partial gasification characteristics of a high-ash coal were studied in a small scale fluidized bed.The influence of steam/coal ratio, gasification temperature, O2/N2 equivalence ratio(ER) on syngas quality was investigated.The results show that increasing steam/coal ratio could accelerate the water-gas shift reaction, thus leading to increased H2 and CO2 yield, and decreased CO yield.However, increasing steam/coal ratio reduces the low heat value (LHV).So the optimized steam/coal ratio falls between 0.45 and 0.5g/g.With the increasing of temperature, the concentration of H2 and CO increases, and the concentration of CO2 and CH4 decreases.Increasing ER could facilitate the combustion of H2 and carbon, therefore it could enhance carbon conversion and increase the yield of CO2.