原糖和脱水糖模型化合物的快速热解特性研究

Characterizing the Fast Pyrolysis of Oligosaccharides and Anhydro-Sugars as Cellulose Model Compounds

本研究通过几种纤维素的模型化合物(左旋葡聚糖、纤维二聚糖、纤维三聚糖、纤维四聚糖、葡萄糖、纤维二糖、纤维三糖)在Py-GC—MS上的快速热解实验,通过研究其热解产物的分布规律并比较几种主要产物的峰面积绝对值的变化,来揭示纤维素热解过程中糖类的生成机理及转化途径。实验结果表明,脱水糖和原糖在热解产物分布上存在很大的差异,原糖和脱水糖相比较,产物中糖类的峰面积百分比明显降低,伴随的是呋喃类的峰面积的明显增加;原糖中,5-羟甲基糠醛和糠醛产率均随着聚合度的升高而增加,脱水糖中则相反。两类糖的左旋葡聚糖的产率随着聚合度的升高增加,而左旋葡聚糖酮的产率随着聚合度的升高呈现相反的趋势。

Several model compounds of cellulose（levoglucosan,cellobiosan,cellotriosan,cellotetraosan,glucose,cellobiose,cellotriose） were pyrolyzed by Py-GC-MS.From the product distribution and the differences of main products between model compounds,a better understanding about the generation and evolution of saccharides is anticipant.The result shows a distinct difference between the product distributions of oligosaccharides and anhydro-sugars.A higher peak area percentage of saccharides is obtained from oligosaccharides than that from anhydro-sugars,while furans follow a crosscurrent.Besides,in the pyrolysis of oligosaccharides,with an increasing degree of polymerization,the yield of 5-HMF and furfural both increase,however they present reverse tendencies in the pyrolysis of anhydro-sugars.As to levoglucosan and levoglucosenone,the former increases with an increasing DP in both kinds of model compounds,and the latter present reverse tendencies.