Experimental study of oxygen-enriched gasification in circulating fluidized bed

On the test rig of oxygen-enriched gasification in circulating fluidized bed, the effects of oxygen concentration and equivalent ratio on gas components, gas production rate, cold gas efficiency and carbon conversion are investigated, when the gasification temperature is kept at 910 ℃ by adjusting steam flow. The results show that when oxygen concentration increases from 25% to 40%, N₂ reduces from 48.82% to 33.83%, H₂ increases from 21.47% to 27.59%, and CH₄ changes little. Due to the influence of steam flow, CO decreases and CO₂ increases when oxygen concentration is higher than 35%. Heat value of the gas with the oxygen concentration of 40% is 1.84 times of that with air gasification. Gas production rate decreases from 2.35 m³/kg to 2.13 m³/kg, and both of cold gas efficiency and carbon conversion increase with the increase in oxygen concentration. As equivalent ratio changes from 0.20 to 0.29, N₂ reduces and then increases, H₂ grows from 24.01% to 25.46% and then remains unchanged, CO and CH₄ keeps reducing, CO₂ keeps increasing, and gas production rate increases from 1.94 m³/kg to 2.29 m³/kg. Influenced by both stem flow and equivalent ratio, cold gas efficiency increases firstly and then decreases, and carbon conversion keeps increasing.