生物质烘焙预处理对气流床气化的影响

TORREFACTION IMPACT ON BIOMASS ENTRAINED FLOW GASIFICATION

为考查生物质在烘焙预处理过程中的能量产率和颗粒研磨变化规律及对气流床气化总体效率的影响情况,在一套小型烘焙试验台上,对4种不同种类的生物质进行烘焙试验,并对固体产物研磨后进行粒径分析,最后通过小型生物质气流床进行气化试验。结果表明:生物质的能量密度随着烘焙温度的提高而升高,其中,中温烘焙(～250℃)能获得较好的固体和能量产率,减少能量损失;烘焙温度是烘焙过程中最重要的影响因素;烘焙可减少生物质研磨时的电耗,使其易磨;气流床气化试验中,烘焙生物质能够改善煤气成分,提高气化的总体效率。总之,在生物质气流床气化过程中,烘焙预处理能为生物质的粒径减小和随后的大规模利用提供了一个良好的解决途径。

In order to find the relationship between biomass torrefaction and its energy density, particle size and overall gasfication efficiency, torrefaction experiments were carried out in a lab-scale reactor with four kinds of biomass as feedstocks. The size distribution of torefaction residues and characteristics of its entrained flow gasification were studied experimentally. The results reveal that biomass energy density becomes higher after its torrefaction while the torrefaction temperature and reaction time increase. The temperature impacts on the characteristics of biomass torrefaction efficiently were compared with the reaction time. The torrefaction can induce a great deal of the power consumption for biomass crushing and make it to be crushed easily. The biomass torrecfaction will be helpful to increase the overall gasification efficiency during the entrained flow gasification with the torrefied biomass. Therefore, it provides a solution to the problems concerned with entrained flow gasification related to size reduction of biomass and the subsequent available on large scale commercially.