纤维素微波热解基础研究

Study on microwave-assisted pyrolysis mechanism of cellulose

为了改善生物质热解油品质,有必要开展微波选择性热解的基础研究。以微晶纤维素为模型,研究微波热解温度、微波吸收剂(催化剂)等条件对产物分布组成规律的影响,确定了呋喃类和糖类是裂解的主要产物。通过分析几种主要产物的变化行为和转化途径,认为微波特有的"体加热"机制促进了3,6-脱水吡喃糖开环路径、左旋葡萄糖二次脱水以及通过C2和C5的缩合形成呋喃结构葡萄糖苷。在此基础上,探讨了纤维素微波热裂解机理模式。

This study was intended to evaluate the effects of catalysts on selectivity production of biomass microwave-assisted pyrolysis. Microcrystalline cellulose was investigated to the effect of pyrol- ysis temperature and microwave absorber （catalyst） on distribution and composition of products. The pyrolysis behavior of several major products was analyzed to conclude the evolution mechanism of cel- lulose. The results showed that furfurals and sugars were main component of pyrolysis products. It was proposed that the merit “internal heating” of microwave maybe promote three main sets of chemical pathways to describe the possible fission of cellulose, one ascribed to ring-opening of 3, 6-anhydro-glu- copyranose, two to second dehydration reaction of levoglucose, another to the formation of glucofuranose through structure rearrangement on C2 and C5. At the end of the study, an integrated model of cellulose pyrolysis was developed to improve the bio-oil quality.