Pt/SAPO-11催化剂上苯加氢转化及苯对正十四烷异构化反应的影响

在10 mL连续流动固定床反应装置上,以苯的转化为模型反应考察了Pt／SAPO-11异构化催化剂的加氢性能及苯对正十四烷异构化反应的影响。结果表明,Pt／SAPO-11催化剂具有良好的加氢性能;苯的加入对正十四烷的异构化反应没有明显影响。苯的转化为温度敏感型反应,临氢条件下以生成加氢产物环己烷和加氢异构化产物甲基环戊烷为主,裂解反应产物极少。低温、高压、低氢分压和低空速有利于苯的加氢转化;产物选择性主要与温度有关,其它反应条件的影响很小;提高反应温度有利于加氢异构化产物甲基环戊烷的生成。正十四烷存在时反应历程发生改变,苯加氢产物以生成环己烷为主,由苯加氢中间体与正十四烷发生氢转移反应生成。

Hydrogenation of Benzene and Its Influence on Hydroisomerization of n - Tetradecane Catalyzed by Pt/SAPO- 11 Catalyst

Hydrogenation of Pt/SAPO -11 isomerization catalyst and effect of benzene on n - tetradecane hydroisomerization were investigated using benzene hydrogenation as a model reaction in a 10 mL fixed - bed down-flow reactor system. Pt/SAPO -11 catalyst had good hydrogenation activity. Benzene had only slight influence on hydroisomerization of n - tetradecane. Hydrogenation of benzene was found to be a temperature sensitive reaction. Both cyclohexane as hydrogenation product and methylcyclopentane as hydroisomerization product were obtained accompanied with very small amounts of cracking products. Benzene hydrogenation was facilitated at low reaction temperature, low hydrogen partial pressure, high reaction pressure and small space velocity. Product selectivity correlated mainly with reaction temperature. Selectivity of methylcyclopetane increased with reaction temperature. Results support the view that hydrogenation of benzene occured on acid sites in the vicinity of metal sites. Both cyclohexane and methylcyclopentane were primary products. In the presence of n - tetradecane, the main product of benzene hydrogenation was cyclohexane. A new reaction pathway of hydrogen transfer reaction between n - tetrdecane and intermediate of benzene transformation was proposed.