分子筛催化合成MTBE反应失活动力学

Deactivation Kinetics of Methyl Tert-Butyl Ether Synthesis Over Zeolite

在改性β分子筛液相催化异丁烯与甲醇合成MTBE反应动力学的基础上,考察了内扩散阻力和催化剂失活对醚化反应的影响。假设符合平行失活机理,建立了带内扩散阻力的失活动力学方程,通过实验数据拟合确定了失活动力学参数。计算结果表明,醚化失活机理符合平行失活机理,异丁烯与甲醇合成MTBE的同时,发生副反应生成积碳是失活的原因。该失活动力学方程能很好地拟合试验数据,统计检验表明在置信度为99%以下是适合的。用所建失活模型预测了反应温度、催化剂颗粒度及进料时间对催化剂相对活性、有效因子和异丁烯转化率的影响。

The influence of internal diffusion and catalyst deactivation on etherification were investigated after the macroscopic kinetics model of the liquid phase synthesis of methyl tert-butyl ether (MTBE) from methanol and isobutylene was studied experimentally over modified-( zeolite catalyst had been developed. A deactivation kinetics considering of the effects of internal diffusion and catalyst deactivation had been developed on the assumption that the catalyst deactivation was parallelism. The parameters involved in the deactivation kinetics equation were determined by a parameter estimation method. The calculation results show that the deactivation fit parallel deactivation mechanism, cocking is the main reason for catalyst deactivation. This kinetics model fits the experimental data well. Statistical test shows that this kinetics model is credible under the confidence of 99%. The influence of reaction temperature, catalyst particle size and reaction time on the relative activity, effectiveness factor and conversion of isobutylene are forecasted by the deactivation kinetics model.