Mechanism of Formation and Consequent Evolution of Active Cellulose during Cellulose Pyrolysis
Mechanism of Formation and Consequent Evolution of Active Cellulose during Cellulose Pyrolysis
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纤维素热解过程中活性纤维素的形成及其演变机制
DOI：
10.1016/s1872-1508(08)60078-9
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发表时间：
2008-11-01
影响因子：
10.9
通讯作者：
Cen Ke-Fa
中科院分区：
文献类型：
--
作者：
Liu Qian;Wang Shu-Rong;Cen Ke-Fa
在高辐射快速热解反应器中得到了黄色、可溶的固体中间产物。在两种不同的辐射热通量下，产率都呈现先增加后增加的趋势，并随着反应的进行而逐渐趋于稳定。在高效液相色谱（HPLC）上进行黄色产物的组成分析。结果表明，产物主要由低聚糖、葡萄糖、左旋葡聚糖、甲基乙二醛等组成，其中包括纤维二糖、纤维三糖等低聚糖和葡萄糖等单糖的化合物被认为是活性纤维素。在较高的热通量下。活性纤维素的相对产率最初增加，随后呈下降趋势，并且在可溶性黄色产物中达到最大质量分数68%（w）。高聚合度的低聚糖是主要成分。在较低的热通量下，活性纤维素的产率相对较低，达到约57%（w）的最大值。含有较多的低聚合度聚乙烯。结果表明，活性纤维素在高温下很不稳定，易分解为低聚合度的淀粉、焦炭、挥发物和气态产物。最后提出了一种改进的机理来描述纤维素热裂解过程中活性纤维素的生成和演化。
An intermediate product that wits yellow, soluble, and solid was obtained in a high-radiation flash pyrolysis reactor. Under two different radiant heat fluxes, the yields tended to both increase initially until achieving a steady state, and then increase again with the progress of reaction. The compositional analysis of the yellow product was performed on high performance liquid chromatography (HPLC). It was indicated that the product mainly consisted of oligosaccharides, glucose, levoglucosan, methylglyoxal and so on. The compounds including oligosaccharides such as cellobiose and cellotriose, and monosaccharides such as glucose were regarded as active cellulose. Under the higher heat flux. the relative yield of the active cellulose increased initially, followed by a decreasing trend, and achieved a maximum mass fraction of 68% (w) in the soluble yellow product. The oligosaccharides with higher degree of polymerization (DP) were the primary components. Under the lower heat flux the yield of active cellulose was relatively lower, achieving a maximum of about 57% (w). and more saccharides with lower DP were contained. It was suggested that active cellulose was quite unstable at high temperature, and easily decomposed into saccharides with lower DP, even char, volatiles, and gaseous products. Finally an improved mechanism was proposed to describe the reaction route of formation and consequent evolution of active cellulose during cellulose pyrolysis.