Zeolite Membrane Ethylbenzene Dehydrogenation Module Pilot Study

The combination of reaction and separation into a single process is an engineering goal in the chemical industry that has recently become more feasible with the commercial availability of inorganic membranes. These membrane have structural strength, remain viable at high temperature and resist chemical attack. Zeolite membranes, which not only have general characteristics of inorganic membranes, but also have the important properties of zeolite sieves, is an ideal kind of material for catalysis and seperation, and have become a research hotspot. The great majority of work on membrane reactors has dealt with the removal of product hydrogen in reversible dehydrogenation reactors, in order to achieve conversions above the theoretical equilibrium.Styrene is an important organic chemical raw material, and was widely used in the production of plastic and synthetic rubber. A good separation factor is to be expected between hydrogen and the much larger ethylbenzene and styrene molecules. Thus the application of inorganic to the process of dehydrogenation of ethylbenzene has drawn increasing attention.In this paper, a module-separated ethylbenzene dehydrogenation reactor is set up, which can produce 25 tons styrene per year. A two-dimension model of it is formulated. In this model, the main and side reactions are considered. The method of difference is used to resolve the model. And results such as the distributing of temperature and the conversion of ethylbenzene, selectivity, etc. are reached.Operation parameters are also investigated. The effect of temperature, pressure, ratio of water to hydrocarbon, etc. is analyzed. Operation parameters are optimized. This provide basis for the later experiments and the industrialization of the application of zeolite membranes to the process of dehydrogenation of ethylbenzene.