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化学学报
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化学学报 ›› 2009, Vol. 67 ›› Issue (18): 2081-2086. 上一篇    下一篇

研究论文

纤维素单体热解机理的热力学研究

黄金保a 刘 朝*,a 魏顺安b   

  1. (a重庆大学动力工程学院 重庆 400030)
    (b重庆大学化工学院 重庆 400030)
  • 投稿日期:2009-02-05 修回日期:2009-03-27 发布日期:2009-12-31
  • 通讯作者: 刘 朝

Thermodynamic Studies of Pyrolysis Mechanism of Cellulose Monomer

Huang, Jinbaoa Liu, Chao*,a Wei, Shunanb   

  1. (a College of Power Engineering, Chongqing University, Chongqing 400030)
    (b College of Chemical Engineering, Chongqing University, Chongqing 400030)
  • Received:2009-02-05 Revised:2009-03-27 Published:2009-12-31
  • Contact: Liu, Chao

被引次数

55

为了了解纤维素热解机理, 结合相关实验结果对纤维素单体(β-D-吡喃葡萄糖)的热解设计了四种热解反应途径. 利用Gaussian 03程序, 采用密度泛函理论(DFT), 在UB3LYP/6-31G(d)水平上, 对各反应物和产物的几何结构进行了能量梯度法全优化, 计算了不同温度下各反应路径的热力学参数. 计算结果表明: 所有反应均为吸热反应; 当温度在550 K以上时, 所有反应都能自发进行. 从热力学的角度分析, 热解更有利于发生开环反应而形成乙醇醛、1-羟基-2-丙酮、CO等小分子产物.

关键词: 纤维素单体, 热解, 密度泛函理论, 热力学参数

For understanding the pyrolysis mechanism of cellulose, four kinds of paths of pyrolytic reaction were designed for the thermal decomposition of the cellulose monomer (namely β-D-glucopyranose) according to related experimental results. At the UB3LYP/6-31G(d) level of density functional theory, the equilibrium geometries of the reactants and products were optimized and the standard thermodynamic parameters of every reaction path in different temperature ranges were calculated by the help of Gaussian 03 package. The thermodynamic calculation results show that all above reactions are endothermic processes and can take place spontaneously when temperature of reaction exceeds 550 K. According to thermodynamic points of view, the pyrolysis of cellulose monomers favors to produce low molecular weight products, e.g. hydroxyacetaldehyde, acetol and carbon monoxide.

Key words: cellulose monomer, pyrolysis mechanism, density functional theory, thermodynamic parameter