二甲醚选择性转化制芳烃的热力学分析  

Thermodynamic Analysis for the Selective Conversion of Dimethyl Ether to Aromatics

作　　者：方奕文[1] 沈尾彬[1] 黄晓昌[1] 宋一兵[1] 

机构地区：[1]汕头大学化学系,中国汕头515063

出　　处：《湖南师范大学自然科学学报》2009年第3期68-73,共6页Journal of Natural Science of Hunan Normal University

基　　金：国家自然科学基金资助项目(20576023);广东科技计划资助项目(2008B080701032);汕头大学青年科研基金资助项目(YR07002)

摘　　要：气相三甲基苯的标准生成热ΔfH2θ98.15(g)用沃森(Watson)经验方程估算,标准熵S2θ98.15用键熵法估算,摩尔等压热容Cp,m随温度的变化趋势通过多项式回归的方法得到.在此基础上,计算二甲醚芳构化体系各主要反应的标准摩尔焓变ΔrHθm、吉布斯自由能变ΔrGmθ、平衡常数lnK与温度T的关系.结果表明,在分析的温度范围内,二甲醚反应生成C1～C9芳烃均为放热反应,吉布斯自由能变均为负值,平衡常数随温度升高而减小,说明反应能自发进行,升高反应温度不利于芳烃的生成.The standard formation heat of gaseous trimethylbenzene was estimated with Watson empirical equation. The gaseous trimethylbenzene＇s ,tandard entropy was calculated with bond entropy method and its heat capacity changing trend with temperatures was obtained according to polynomial regress. On this basis, the standard molar enthalpy, the Gibbs free energy change and the reaction equilibrium constant of the main reaction for the selective conversion of dimethyl ether to aromatic at different temperature were calculated. The results showed that the reactions of dimethyl ether to C6 -C9 aromatics were exothermic within the analytic temperatures. The Gibbs free energy changes were negative, and the reaction equilibrium constants decrease with temperature increase. It indicatedthat these reactions could process spontaneously, and high temperature was not avail to the formation of aromatics.

关 键 词：二甲醚 三甲基苯 芳烃 热力学分析 

分 类 号：O641[理学—物理化学]