稻壳循环流化床气化试验研究

Study on rice husks gasification experiment in CFB

以稻壳为原料，空气为气化介质进行循环流化床气化试验研究，探讨气化过程中空气当量比与温度和燃气成分的关系，以及炉膛内气化反应温度对燃气质量的影响。试验结果表明：空气当量比的增大，使得炉膛内温度升高，炉膛底部温度与其他测点间的温差增大，炉膛中间段温度高于两端温度；同时随着空气当量比的增大，燃气中H2、CO和CH4的含量先增加后减少，CO2的含量先减少后增加，O2含量变化不大，而燃气热值则呈现先增加后减小的趋势。比较试验结果表明，空气当量比的理想取值范围为0．22～0．28，最佳值为0．26。炉膛内气化反应温度的升高，使得燃气中可燃气体成分含量先增加后减少，最佳气化温度为750℃。

Biomass gasification provides an ideal solution for the energy conversion of agricultural and forestry residues with the end products as producer gas, liquid fuel, electricity and heat. CFB （circulating fluidized bed） was applied in this work as the gasification reactor for the test of rice husks gasification with air as the fluidizing and gasifying agent. Extensive tests were performed to investigate the effect of air equivalent ratio （ER） and gasification temperature on producer gas quality. The increase of ER, which means more air supply into the gasifier, would cause severe oxidation reaction leading to higher temperature profile in the reactor. And the producer gas composition would strongly varied with rising ER, the content of hydrogen, carbon monoxide and methane will increase to a certain level and then decrease at higher ER, resulting a peak for heating value of gas product, And the content of carbon dioxide will increase dramatically when ER is larger than 0. 26, due to excessive oxidation process. So the ideal range of ER is 0.22 - 0.28. The temperature in the gasifier would have great influence on the product distribution. The combustible components in the producer gas would increase d and then decrease with increasing temperature. The optimal conditions for quality producer gas would be controlled at 750 centigrade with ER at 0.26.