摘要
The developed SEMK model is used to provide an insight into the contribution of individual reactions in the cracking of methylcyclohexane as well as the site coverage by various carbenium ions. The preferred reaction pathways for the conversion of methylcyclohexane are hydride transfer reactions followed by PCP-isomerizations, deprotonation and endocyclic β-scission, accounting for 61%, 22% and 12% of its disappearance, respectively, at 693 K and 30% conversion of methylcyclohexane. Protolysis plays a minor role in the cracking of methylcyclohexane. Once cyclic diolefins are formed, all of them can be instantaneously transformed to aromatics, which are easily interconverted via disproportionation. Judging from the carbenium ion concentrations it is evident that, at the investigated operating conditions, less than 5% of the acid sites are covered by carbenium ions, less than 2% of which corresponds to cyclic type species including allylic ones.
The developed SEMK model is used to provide an insight into the contribution of individual reactions in the cracking of methylcyclohexane as well as the site coverage by various carbenium ions. The preferred reaction pathways for the conversion of methylcyclohexane are hydride transfer reactions followed by PCP-isomerizations, deprotonation and endocyclic β-scission, accounting for 61%, 22% and 12% of its disappearance, respectively, at 693 K and 30% conversion of methylcyclohexane. Protolysis plays a minor role in the cracking of methylcyclohexane. Once cyclic diolefins are formed, all of them can be instantaneously transformed to aromatics, which are easily interconverted via disproportionation. Judging from the carbenium ion concentrations it is evident that, at the investigated operating conditions, less than 5% of the acid sites are covered by carbenium ions, less than 2% of which corresponds to cyclic type species including allylic ones.
基金
the financial support from the China Scholarship Council
the Long Term Structural Methusalem Funding by the Flemish Government
关键词
二烯烃
裂解
环烷烃
单事件
氢转移反应
催化
评估
碳正离子
catalytic cracking
single-event microkinetic model
cycloparaffin
olefin
site coverage by carbenium ions