玉米秸秆与煤流化床的共气化特性

Characteristic of Co-gasification of Corn Stalks and Coal in Fluidized-bed

以玉米秸秆与无烟煤为原料,在循环流化床中进行空气-水蒸汽气化实验,采用预热装置将气化剂(空气、水蒸汽)由常温加热至500℃,考察气化温度、气化剂类型及生物质掺混比对气化燃气组分和热值、气化效率及碳转率等指标的影响.结果表明,提高气化温度可增大碳转化率及气化效率,950℃时无烟煤单独气化效率最高,850℃时玉米秸秆掺混比为20%的混合试样气化效率最高.选择空气-水蒸汽作气化剂时,H2体积分数由1.80%增至15.53%.玉米秸秆掺混比增加可促进CO生成,抑制CO_2生成,掺混比高于40%时会降低燃气热值及碳转化率.空气作气化剂,玉米秸秆掺混比为20%时燃气热值最高,空气-水蒸汽作气化剂,玉米秸秆掺混比40%时燃气热值最高.

To study the influence of gasification temperature, gasification agents and blending ratios on gas component, low heat value （LHV）, gasification efficiency and carbon conversion rate, experimental tests were investigated by air vapor from room temperature to 500 ℃ during co-gasification in a circulating fluidized bed. The results showed that the rising gasification temperature would improve the carbon conversion rate and the gasification efficiency. Furthermore, the highest gasification efficiency of anthracite gasification was at the temperature of 950 ℃, and the highest gasification efficiency of corn stalks sample with 20% blending ratio was 850 ℃. As the air-vapor was acted as the gasification agents, the volume fraction of Hz increased from 1.80% to 15.53%. In addition, the addition of corn stalk would promote the generation of CO, whereas inhibit the generation of CO2. LHV, carbon conversion rate and gasification efficiency decreased when blending ratio exceeded 40%. With air being the gasification agent and corn-talks blending ratio at 20%, LHV was the highest, and air vapor as the gasification agent, LHV reached the highest when the blending ratio was 40%.