In order to study the effect of minerals on biomass pyrolysis, experiments on pyrolysis of corn straw with different pretreatment methods were performed by using a thermogravimetric analyzer（TGA） coupled with a Fourier transform infrared （FTIR） spectrometer. The pretreatment methods included water washing and acid washing. The experimental results show that acid washing can remove almost all K^＋ and 78% of Ca^2＋ , while water washing only removes most of K ^＋. The existence of K^＋ and Ca^2＋ obviously favors the formation of compounds containing carbonyl groups and CO2 , but it will decrease the yields of compounds containing C-O-C groups. However, the formation of H2O, CO and CH4 are slightly affected by the removal of inorganic ions. With regard to the structure of the metal ions-adsorbed cellulose characterized by IR analysis, it can be considered that there is an ＂ion force＂ between metal ions and cellulosic biomass. The results of thermal kinetic analysis show that this force can make the reaction activation energy of the biomass pyrolysis decrease. A new mechanism is proposed for explaining the effect of inorganic ions on cellulose pyrolysis.
YANG Chang-yanLU Xue-songLIN Wei-gangYANG Xue-mingYAO Jian-zhong
下行循环流化床反应器要求气固分离器具有分离效率高、气相停留时间短、压力损失小、设备磨损小等特点。利用气固二相在惯性上的差别,提出了一种新型同轴双锥两级气固快速分离器,并以FCC(F lu id Catalytic Crack ing)为循环物料对该型分离器的分离特性进行了研究。结果表明,同轴双锥两级气固分离器的分离效率在98%以上,气固分离器的压力损失在100 Pa以下,设备磨损小,能够满足下行循环流化床反应器的要求。
