液相法苯选择加氢制环己烯催化反应动力学方程

Kinetic Equations for Liquid-Phase Selective Hydrogenation of Benzene to Cyclohexene

测定了Ru M B/ZrO2 催化剂上选择加氢制环己烯反应过程中苯、环己烯及环己烷浓度随时间变化的c～t曲线 ,获得了苯选择加氢制环己烯反应中各步反应的级数和速率常数等动力学参数 .结果给出 ,苯转化的反应级数对苯为 1,对氢低压下为 2 ,高压下为 0 ;环己烯继续加氢生成环己烷的反应级数对环己烯为 0 ,对氢低压下为 2 ,高压下为 0 .在此基础上建立了苯选择加氢制环己烯各步反应的动力学方程 。

The Ru-M-B/ZrO_2 catalyst with high selectivity for cyclohexene from benzene hydrogenation was prepared. Under the conditions of no inside and outside diffusion, the curves of the concentration of benzene, cyclohexene and cyclohexane versus time over the Ru-M-B/ZrO_2 catalyst were measured. Some kinetic parameters of the selective hydrogenation of benzene to cyclohexene such as reaction order and rate constant in each step were obtained. It was concluded that the benzene conversion is first order with respect to benzene, and with respect to hydrogen, it is second order at low pressure, fraction order at middle pressure and zero order at high pressure. While the cyclohexene hydrogenation to cyclohexane is zero order with respect to cyclohexene, and with respect to hydrogen, it is second order at low pressure, fraction order at middle pressure and zero order at high pressure. Based on these results, the kinetic equations of benzene hydrogenation to cyclohexene in each step were given. The kinetic equations were also confirmed based on the experimental data. The reason for the reaction order in each step was also discussed.