Numerical Analysis for Performances of Membrane Reactor to Design A Combined Reaction System with Simultaneously Separation

膜反应器是一种在化学反应过程中提供更高生产率和分离成本的反应系统。基于数值模拟的膜反应器分析主要采用一维模型，不能表达径向热量梯度和浓度梯度。然而，在膜反应器中产生高反应热的反应或在反应器的精确分析中，径向的传质和传热是必不可少的。在本研究中，我们开发了一个数值模拟器，考虑了轴向和径向的传质和传热，以准确地分析乙苯脱氢膜反应器内的温度分布和氢的渗透特性。本研究得到的结果概括如下：利用横截面上的等高线计算膜反应器内的温度分布，表明反应器内的温度分布变化很快，因为乙苯脱氢是一个比较大的吸热反应。结果表明，膜的透氢率随进气距离的变化而变化，假设等温条件下的转化率高于考虑温度梯度时的转化率，则前者的期望值较高，且随着进气量的增加，两者之间的差值逐渐增大。结果表明，考虑反应器内轴向和径向的温度分布，可以准确地预测具有较高反应热的膜反应器的性能。精度被认为随着反应管半径的增加和/或反应热能的增加而增加。

A membrane reactor is a reaction system that provides higher productivity and separation cost reduction in the chemical reaction processes. Analyses of membrane reactors based on numerical simulation were mainly made using single-dimension models, which cannot express radial heat and concentration gradients. However, consideration of mass transfer and heat transfer in the radial direction is indispensable in reactions generating highly reaction heat in a membrane reactor, or in precise analysis of reactors.In this research, we developed a numerical simulator, taking into account the mass transfer and heat transfer in the axial and radial directions, to make an accurate analysis of temperature distribution and hydrogen permeation characteristics in a membrane reactor for ethylbenzene dehydrogenation.The results obtained in this research can be summarized as follows :The temperature distribution in the membrane reactor, using contour profile lines against the cross section, indicates a considerably rapid change in the temperature distribution in the reactor, because of dehydrogenation of ethylbenzene being a relatively large endothermic reaction. The result suggests that the hydrogen permeability for the membrane vary with the distance from the inlet.The case assuming the isothermal condition has a higher conversion than the one considering the temperature gradient The former expected value is relatively high and the difference between the values is gradually increased as the feed gas rate is increased. The results clearly demonstrate that consideration of the temperature distributions of the axial and radial directions in the reactor lead to an accurate expectation of the performance for membrane reactor with a highly reaction heat. The accuracy is considered to increase as the radius of the reactor tube is increased, and/or as the amount of thermal energy for the reaction is increased.