半纤维素热解反应的微观反应机理研究

采用密度泛函理论(DFT)方法,以半纤维素热解反应中的典型产物2-糠醛为切入点,对半纤维素模型化合物4-O-甲基-D-葡萄糖醛酸-D-木糖在温度范围(300~1100K)内进行了热解反应机理研究。研究发现,热解反应分为两个阶段,第一阶段为二聚体模型化合物的解聚,第二阶段为解聚后的两个单体分别反应生成2-糠醛的过程。计算结果表明:700K左右为二聚体模型化合物发生解聚的最佳温度,其支链发生分解反应的最大反应速率所对应的温度为500K左右,其主链分解反应的最大反应速率所对应的温度为700K左右。

Research on the Microscopic Mechanism of Hemicellulose Pyrolysis Reaction

The semi cellulose pyrolysis of typical product 2 - furfural as the breakthrough point by using densi- ty functional theory, semi cellulose model compound 4 - O - methyl - D - glucuronic acid - D - xylose is stud- ied with the pyrolysis mechanism in the paper. Analysis shows that there are two stages to study in the pyrolysis re- action. The first stage is the depolymerization two dimer model compounds, process generates 2 -furfural as two monomer respectively after the second stage reaction depolymerization. The calculation result indicates that the best reaction temperature of the dimers depolymerization is 700K . The highest reaction rate of the branched chain de- composition is at 500K while that of the main chain is at 700K.