| The micropore zeolite means molecular sieve with the the pore size under 2 nm.Up to now,more than one hundred kinds of micropore molecular sieve have been found or synthesized.The most popular molecular sieves are LTA,FAU,MFI.Owing to their unique physical and chemical characteristic and similar molecular-sized channel systems,zeolite membranes can not only work at high-temperature,chemical and biological corrosive environment but also have potential applications for separation processes.In the last decades, much progresses have been made on the research of zeolite membranem.It is very important to research the preparation and application of zeolite membrane.The main research of this paper was as follows:The NaA membrane was synthesized on the inner surface ofα-Al2O3 support with the dynamic hydrothermal synthesis,and this kind of membrane was applied in the separation of ethanol/water;The effect of parameters on synthesis of the NaY membrane was studied,and it was used in the separation of benzene/cyclohexane and dichloroethane/nitrogen.The effect of parameters on synthesis of the NaX membrane was researched,and it was used in the separation of benzene/nitrogen. The ZSM-5 membranes were synthesized and was applied in the dehydrogenation of ethylbenzene to styrene.The main results achieved were as follows:The NaA membrane was synthesized on the inner surface ofα-Al2O3 support with the dynamic hydrothermal synthesis,the H2 permeance of as-synthesized NaA membrane was 7.66×10-7mol/(m2·s·Pa),the idea separation factor of H2/C3H8 was 4.85,respectively.This kind of membrane was applied in the separation of ethanol/water and the permeance flux was 1.5kg/(m2·h) and the separation factor was 9500.These results indicated that the NaA membrane prepared with the dynamic hydrothermal synthesis was feasible.NaY zeolite membranes in out surface ofα-Al2O3 ceramic tube were synthesized by forming a seeding layer via hot dip-coated method,followed by secondary crystallization method.NaY zeolite membranes were used to separate the mixture of benzene and cyclohexane by pervaporation.The influence of operation temperature,operation pressure difference,feed flow rate and content of benzene in feed was studied thoroughly.The NaY zeolite membranes showed benzene permselective in pervaporation experiments (benzene-cyclohexane).With mass fraction of benzene 50%in benzene-cyclohexane mixture, separation factor of the membrane was 13.6,permeation flux was 0.173kg·m-2·h-1 at 70℃. Y-type membranes were also used to separate the mixture of dichloroethane and nitrogen. The result showed that the separation factor was increased with the increasing of pressure difference.When it reached certain value,the separation factor was decreased with the increasing of pressure difference.When the pressure difference was 50 kPa,the separation factor was 17.7,which was the highest value.Membranes showed different separation ability when they were exchanged with different cations.The CaY membrane showed the separation effect and highest separation factor was almost 30.The order of separation factor of five Y-type membranes was CaY＞NaY≈BaY＞KY≈LiY.The NaX membrane was synthesized on outer surface of theα-Al2O3 support,the permeance rate of H2 was 2.15×10-6mol/(m2·s·Pa),the idea separation factor of H2/C3H8 was 6.19;NaX zeolite membranes were used to separate the mixture of benzene and nitrogen as a new method.The influence of pressure difference,the speed and concentration of the mixture and ion-exchanged degree are studied thoroughly.The result shows that the separation factor is changed with the pressure difference,speed and concentration change.Membranes show better separation ability when they are exchanged with Ag+.When the pressure is 40kPa,the speed is 180ml/min and the concentration is 12%,Ag+-exchanged completely membranes gain the best separation factor:30.1.The ZSM-5 zeolite membrane was synthesized and the idea separation factor of H2/C3H8 was 10.86.The ZSM-5 zeolite membrane was applied in dehydrogenation of ethylbenzene to styrene.With the increasing of pressure difference,the by-product of benzene hardly changed and toluene slightly increased,the conversion of ethylbenzene improved evidently and the selectivity of styrene decreased slightly.With the increasing of space speed,the by-product of benzene and toluene slightly decreased,the conversion of ethylbenzene decreased and the selectivity of styrene increased.With N2 as the sweep gas,the conversion of ethylbenzene and the selectivity of styrene advanced more remarkably,the convesion rate improved 7.52% compared to the condition of the atmospheric pressure.
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