Preparation And Characterization Of ZSM-5 Zeolite Membrane Materials

MFI zeolite crystal (ZSM-5) has a three-dimensional system of intersecting channels with pore size of 0.55 nm, and is suitable for separation of many industrial raw materials because of their excellent characteristics such as thermal stability, acid resistance and good catalysis. ZSM-5 zeolite membranes have been received increasing attention in many fields because of the adjustable Si/Al ratio and good hydrophily property. ZSM-5 zeolite membranes can be used as separation membrane material. Compared with traditional separation methods, membrane techniques for separation has advantages of less energy consumption and pollution-free.The processes of zeolite membrane preparation involving carriers, composition of synthesis solution, hydrothermal synthesis conditions have a great influence on the performance of the membrane. In this paper, the influences of the modified surface of the carriers, composition of synthesis solution, preparation of seed layers were investigated.(1) Electroless plating was used to modify the surface of the carriers. The compositions of electroless plating solution were controlled to obtain an uniform plating layer on the carriers. The impact of different plating time for morphology of the carrier surface were investigated. The single-component gas permeation test was also prepared.(2) Zeolite membranes were prepared on the modified carrier surface by electroless plating. Analyzed the mechanism of the metal elements to promote the growth zeolite membranes and found that zeolite membrane crosslinking effect is perfect on Ni-P plating.(3) Nano crystal seeds were synthesized by in-situ hydrothermal method. The influences of synthetic of liquid water content, crystallization time were systematically investigated. Different methods were used to activated the zeolite seeds and found that the catalytic hydrocracking template method was better. Provide a reference for the removal of zeolite membrane template agent in the future.(4) ZSM-5 zeolite membrane was synthesized by seeding growth method. The influences of different seeds, preparation methods of seed layer and the crystallization conditions of zeolite membrane on integrality of the membranes were systematically investigated. A perfective zeolite membrane can be obtained by tertiary growth method. The zeolite membrane was activated by catalytic hydrocracking method and characterized by one-component permeation experiments.