稠环化合物脱氢反应的热力学计算

THERMODYNAMIC CALCULATION FOR DEHYDROGENATION REACTION OF THICK RING COMPOUNDS

采用Benson基团贡献法对菲(PH)、芘(PY)及2-甲基菲(2-MP)加氢反应网络中欠缺的化合物标准摩尔生成焓、绝对熵和定压摩尔热容进行估算;并以物性数据为基础,计算PH,PY,2-MP加氢反应网络中各反应的反应焓变、反应吉布斯自由能变、平衡常数和转化率。计算结果表明:PH,PY,2-MP加氢反应网络中的脱氢反应均为吸热反应;PH,PY,2-MP加氢反应网络中脱氢反应的平衡转化率均存在反应温度敏感区,调节反应温度可以使各脱氢反应的平衡转化率均趋近于100%;对于加氢程度相同的稠环芳烃加氢产物,甲基支链的存在使得脱氢反应更容易进行;对于加氢程度和甲基支链数相同的稠环芳烃加氢产物,芳环数量越多,脱氢反应越容易进行;在0~2 MPa和300~800 K的反应条件下,高温低压有利于PH,PY,2-MP加氢反应网络中脱氢反应的进行。

The Benson group contribution method was used to estimate the standard molar enthalpy of formation,absolute entropy and constant pressure molar heat capacity of compounds lacking in the hydrogenation reaction network of phenanthrene(PH),pyrene(PY)and 2-methylphenanthrene(2-MP).Based on physical property data,the enthalpy change,Gibbs free energy change,and conversion rate of each reaction in the PH,PY and 2-MP hydrogenation reaction network were calculated.The calculation results showed that the dehydrogenation reaction in the hydrogenation reaction network of PH,PY and 2-MP was all endothermic reactions,and there was a temperature-sensitive region in the equilibrium conversion of dehydrogenation reaction in the hydrogenation network of PH,PY and 2-MP.The equilibrium conversion rate of each dehydrogenation reaction approached 100%by adjusting the reaction temperature,and the existence of methyl branched chain made the dehydrogenation reaction easier for the hydrogenation products of polycyclic aromatic hydrocarbons with the same degree of hydrogenation.For the hydrogenation products of polycyclic aromatic hydrocarbons with the same degree of hydrogenation and number of methyl branches,the more aromatic rings there were,the easier the dehydrogenation reaction was.Under reaction conditions of a pressure of 0-2 MPa and a temperature of 300-800 K,high temperature and low pressure were favorable for the dehydrogenation reaction in the hydrogenation reaction network of PH,PY and 2-MP.