ZnHZSM-5上乙烷脱氢芳构化过程的研究

A study of aromatization of ethane on ZnHZSM 5

研究了乙烷在ＺｎＨＺＳＭ－５上活化、芳构化历程以及芳构化过程中产生的氢气对乙烷脱氢过程的影响。反应结果表明，乙烷在ＺｎＨＺＳＭ－５上主要通过锌的Ｌ酸中心异裂活化直接脱氢生成乙烯，Ｂ酸中心对乙烷活化作用很小，Ｂ酸中心能够促进乙烯聚合和中间物烯烃分子的聚合和环化，锌中心促进芳构化脱氢过程。乙烷在ＺｎＨＺＳＭ－５上的脱氢过程处于准平衡状态，芳构化反应过程中产生的氢气抑制乙烷脱氢生成乙烯。随芳烃产率增大，乙烯的产率下降。

A study is carried out on activation and aromatization of ethane over ZnHZSM 5 and effect of hydrogen formed during aromatization on dehydrogenation of ethane. Reaction results show that ethane is dehydrogenated on ZnHZSM 5 to ethene via isocracking activation over L acid sites of Zn, while B acid sites have little effect on ethane activation.B acid sites can promote ethene polymerizing and also promote polymerization and cyclization of intermediate olefine molecules, i.e.Zn can promote dehydroaromatization of ethane. Dehydrogenation of ethane is at a quasi equilibrium state. A large quantity of hydrogen produced during aromatization inhibits dehydrogenation of ethane to ethene. The yield of ethene decreases with the increase of the yield of aromatics.