5-5′型木质素二聚体高温热解微观化学反应机理研究

发布时间：2018-05-05 04:05

本文选题：木质素 + -′键型　；参考：《材料导报》2016年22期

【摘要】：选用5-5′键型连接的木质素二聚体为研究对象,基于B3LYP/6-31g基组和密度泛函理论(DFT)对其进行了高温热解微观化学反应机理研究,设计了5-5′型木质素二聚体高温热解反应的5条初反应路径,并在分析初反应结果的基础上设计了7条次反应路径,对每条路径的反应物及其产物进行了结构优化,计算了1500K温度下每条反应路径的热力学及动力学参数。结果表明,5-5′型木质素苯环位上的甲氧基具有很强的活性,甲氧基中O-CH3键以及Caromatic-OCH3键较易断裂;通过计算得出初反应的R3、R4反应焓变较小,分别为192.7kJ/mol和270.5kJ/mol,认为该热解反应的主反应路径以R3及R4为主;该热解反应得到的最终产物有3-4,二羟基甲苯、对羟基甲苯、2-乙烯-4-甲基-3,5-二烯环己酮、甲烷、甲醇及甲醛。
[Abstract]:The microchemical reaction mechanism of 5-5'bonded lignin dimer was studied based on B3LYP/6-31g basis set and density functional theory (DFT). Five initial reaction paths for the pyrolysis of 5-5 'lignin dimer at high temperature were designed. Based on the analysis of the initial reaction results, seven reaction paths were designed, and the structure of the reactants and their products of each route was optimized. The thermodynamic and kinetic parameters of each reaction path at 1500 K were calculated. The results show that the methoxyl group on the benzene ring of 5-5 'lignin has strong activity, the O-CH3 bond and the Caromatic-OCH3 bond in the methoxy group are easy to break, and the enthalpy of the initial reaction R3N R4 reaction is smaller. 192.7kJ/mol and 270.5kJ / mol respectively, the main reaction paths of the pyrolysis reaction are R3 and R4, and the final products of the pyrolysis reaction are 3-4, dihydroxytoluene, p-hydroxytoluene 2-ethylene-3-methyl-3-diene cyclohexanone, methane, methanol and formaldehyde.
【作者单位】：长沙理工大学能源与动力工程学院;
【基金】：国家自然科学基金(51276023) 湖南省自然科学基金(2015JJ4005)
【分类号】：O636.2

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