纤维素快速热解生成左旋葡聚糖的机理研究进展

A Review on the Formation Mechanism of Levoglucosan during Fast Pyrolysis of Cellulose

左旋葡聚糖(LG)是纤维素中温快速热解最重要的产物,其生成机理获得了广泛的关注。本文首先总结了国内外不同学者提出的LG生成机理,将其按照反应类型分为4类,即糖苷键均裂反应、糖苷键异裂反应、生成葡萄糖中间体反应以及协同反应,并指出了实验研究在确定反应机理方面的不足。随后总结了近年来一些学者采用密度泛函理论对LG生成机理的研究,具体比较了研究内容和结果,指出了现有研究的不足。最后提出了今后的研究方向以确定LG的生成途径。

During the fast pyrolysis of cellulose at medium temperature,levoglucosan（ LG） is the most abundant product.Its formation pathway has gained extensive attention.This paper firstly concludes and compares the different LG formation pathways proposed by scholars from home and abroad.The formation mechanisms of LG are classified into 4 kinds,namely homolysis cleavage mechanism, heterolysis cleavage mechanism, mechanism via glucose and concerted decomposition mechanism.Drawbacks of analyzing reaction mechanism using experimental methods are also pointed out.The paper then summarizes the recent development,i.e.application of the Density Functional Theory（ DFT）.Its contents and results are compared in detail.Finally,future investigation in determination of the LG formation pathway is proposed.