甲苯歧化与三甲苯烷基转移反应体系的化学平衡

对甲苯歧化与三甲苯烷基转移反应体系中反应的化学平衡常数进行了详细计算,并对不同温度、不同进料组成下的平衡组成进行了分析。结果表明,随温度升高,甲苯与三甲苯的芳烃平衡转化率降低,二甲苯的平衡组成亦降低;降低进料中甲苯和三甲苯的摩尔比,甲苯和三甲苯的总芳烃平衡转化率降低,而二甲苯的平衡组成明显上升。比较了β沸石催化剂上此体系在不同空速和温度下的化学反应产物组成与平衡组成,升高温度有利于缩小化学反应与平衡的差距。

Chemical Equilibrium of Toluene Disproportionation and Trimethylbenzene Transalkylation

In this paper, the chemical equilibrium constants of the reactions in the reaction system of toluene disproportionation and trimethylbenzene transalkylation reaction system were carefully calculated , and the equilibrium compositions of the components at different temperatures and different feed mole ratios were analysed . The results showed that the equilibrium conversion of toluene and trimethylbenzene decreased as temperature increased, and the equilibrium concentration of xylene decreased as well. As Tol/TMB mole ratio in the feed decreased, the equilibrium conversion of toluene and trimethylbenzene decreased. However, the equilibrium concentration of xylene increase dramatically. These results were due to the co-operative effects of toluene disproportionation and trimethylbenzene transalkylation. Using β zeolite as catalyst, the equilibrium compositions and experimental data were compared and the results showed that higher temperature would narrow the gap between experimental data and their equilibrium counterparts.