Zn改性ZSM-5催化甲醇制芳烃反应动力学

摘要

采用Zn改性ZSM-5分子筛催化剂,在等温固定床反应器进行甲醇制芳烃(MTA)的动力学研究.考察了反应温度(360～430℃)、空速(WHSV)(7.8～52h-1)对MTA反应的影响.将MTA反应体系划分为含氧化合物、烯烃、芳烃、烷烃以及C1五个集总,构建新的反应网络和五集总动力学模型.建立的动力学常微分方程采用Runge-Kutta法求解,用单纯形和Levenberg-Marquardt最优化方法拟合得到动力学模型参数.经统计检验验证了所建模型的可靠性,计算值和实验值的对比表明:该模型能够准确地反映MTA反应主要产物分布随温度和空速的变化规律,并能体现产物间的转化.%The lumped kinetics study on methanol to aromatics (MTA) over Zn modified ZSM-5 catalyst was carried out in a fixed-bed isothermal integral reactor.The effects of temperature (360-430℃) and WHSV (7.8-52h-1) on the MTA were investigated.According to the experimental results,the reaction system was separated into five lumps,i.e.MDOH,olefins,aromatics,paraffins and C1.A new reaction network and a kinetics model were developed.The equations of kinetics were calculated with the help of the Runge-Kutta method,the simplex optimization and the Levenberg-Marquardt optimization methods.The statistics confirmed that the established model possessed good accuracy.The comparison between the experimental data and the model prediction results shows the model reflects the MTA product distribution and the conversion between the products accurately under the experimental conditions.