以玉米秸秆与无烟煤为原料,在循环流化床中进行空气-水蒸汽气化试验,采用预热装置将气化剂(空气、水蒸汽)由常温加热至500 ℃,研究了不同气化温度、气化剂类型及生物质掺混比例对气化燃气组分和热值、气化效率及碳转化率等评价指标的影响。结果表明:提高气化温度能增大碳转化率及气化效率,在800~1000℃范围内,无烟煤单独气化950 ℃时气化效率最高,掺混比(m玉米秸秆:m煤)20%的混合试样850 ℃时气化效率最高;选择空气-水蒸汽气化剂时,H2体积分数由1.80%增加到15.53%;随着玉米秸秆掺混比增加,促进了CO的生成,抑制了CO2的生成,但掺混比例大于40%时会降低燃气热值及碳转化率。使用空气作气化剂,掺混比20%时燃气热值最高,选择空气-水蒸汽作气化剂时,掺混比40%时燃气热值最高。
In order 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 during co-gasification in a circulating fluidized bed, experimental tests were carried out with air vapor of room temperature heated to 500 ℃. Results show that the rise in gasification temperature can promote the carbon conversion rate and the gasification efficiency. The highest gasification efficiency of anthracite gasification alone is at 950 ℃ between the range of 800~1000 ℃, and the highest gasification efficiency of corn stalks sample of 20% blending ratio is at 850 ℃. With air vapor being the gasification agents, H2 increased from 1.80% to 15.53%. The addition of corn stalk promoted the generation of CO while inhibited the generation of CO2. But LHV, carbon conversion rate and gasification efficiency decreased when blending ratio exceeds 40%. With air being the gasification agent, the highest LHV appeared at 20% blending ratio, and with air vapor as the gasification agent, the highest LHV appeared when the blending ratio was 40%.