秸秆类生物质与石煤在流化床中的混烧与黏结机理

以玉米秸秆与石煤按不同比例组成的混合物为研究对象，在TG-DTG热分析仪上进行了燃烧特性分析，结果表明玉米秸秆有利于石煤的着火和稳定燃烧，对石煤有一定的助燃作用；在小型鼓泡流化床实验装置上，以石英砂为床料、石煤灰为添加剂，进行了玉米秸秆成型燃料流化床燃烧的床料黏结实验，结果表明：石煤灰能够在生物质流态化燃烧过程中有效地抑制流化床床料黏结现象的发生；通过对实验中形成的结团进行扫描电子显微镜X射线能谱(scanning electron microscopy/Energy-dispersive X-ray- SEM/EDX)，对床料进行X射线荧光光谱(X-ray fluorescence，XRF)分析，结果表明石煤灰中的Al和Fe能够与生物质灰中的碱金属化合物以及低熔点共熔物发生化学反应生成高熔点物质，并且覆盖在生物质碳颗粒与石英砂颗粒表面形成隔绝层，从而阻止低熔点物质的生成与迁移。

Study on Co-firing and Agglomeration Mechanism of Stalk Biomass and Stone Coal in Fluidized Bed

Co-firing characteristics of corn stalk and stone coal in different proportion were investigated by thermal gravimetric analysis. The results showed that corn stalk can improve the ignition and combustion of stone coal. The agglomeration experiments on corn stalk were made in a bench-scale bubbling fluidized bed with quartz sand as bed material and stone coal ash as additive. The results indicate that stone coal ash can inhibit agglomeration of bed material particles at temperature of 900℃. Agglomerate of blends was analyzed by means of scanning electron microscopy, energy-dispersive X-ray (SEM/EDX), and the bed materials were analyzed by means of X-ray fluorescence (XRF). Analysis showed that aluminum element and iron element in stone coal ash can react with alkali compounds and eutectics with low melting point, form a covering layer with high melting point on the surface of biomass and quart sand particles, thus inhibit the forming and transfer of low melting compounds.