Method for preparing NaA molecular sieve membrane by inner surface of asymmetric micro-pore ceramic

Abstract

The invention belongs to the technical field of preparation of molecular sieve membranes and in particular relates to a method for preparing a NaA molecular sieve membrane by an inner surface of asymmetric micro-pore ceramic. The method comprises: taking polyhedron aluminum oxide powder as aggregate, and uniformly mixing and stirring the aggregate with a binding agent, water, a moisturizing agent and a dispersant to form mud; sintering the mud to obtain a porous carrier A; coating a suspension solution to the inner surface of the carrier A for decorating by adopting a dipping and lifting process; drying, sintering and keeping the heat to obtain a molecular sieve membrane supporting body B; fixing the molecular sieve membrane supporting body B into a reaction kettle containing molecular sieve membrane crystallization liquid; carrying out upper and lower rotary hydrothermal synthesis to obtain the NaA molecular sieve membrane. By adopting the method provided by the invention, the surface of the supporting body is more flat and the pore diameter distribution is uniform; the possibility that molecular sieve crystal grains are sunk into macro-pores of the carrier is avoided; the prepared molecular sieve membrane has relatively low permeation resistance and the separation efficiency is improved.

Description

technical field [0001] The invention belongs to the technical field of preparing molecular sieve membranes, and in particular relates to a method for preparing NaA molecular sieve membranes on the inner surface of asymmetric microporous ceramics. Background technique [0002] Molecular sieve membrane is a new type of inorganic membrane material that can realize molecular sieve. The molecular sieve membrane supported by microporous carrier combines the performance characteristics of carrier and molecular sieve. It has uniform molecular sieve pore size, large specific surface area, exchangeable cations and Modulated solid acid / alkaline and other structural characteristics, and has the advantages of general inorganic membranes such as high temperature resistance, chemical corrosion resistance, and high mechanical strength. It is widely used in the separation and purification of organic solvents and gas separation and purification. For example, the separation and purification of...

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Problems solved by technology

CN101746776A discloses a method for synthesizing NaA molecular sieve membranes on the outer surface of α-alumina hollow fibers, wherein the pore size of the hollow fibers is 0.05-2 microns; CN105056769A discloses a preparation method and device for NaA molecular sieve membranes; CN105195029A discloses a Methods for synthesizing NaA-type molecular sieve crystals and NaA-type molecular sieve membranes; currently published patents on the preparation of molecular sieve membranes are mainly on the preparation methods and process conditions of molecular sieve membranes, and there are few reports on the process of combining the structure of the support with the membrane growth process

These carriers have different constraints on the prepared molecular sieve membranes, such as a single-channel symmetrical structure support with a wall thickness of 2-3mm. This support has wall thickness, long permeation path, small surface / volume ratio and high cost. and other problems; and the outer surface is easy to be bumped, so it is not suitable for transportation

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