Preparation method of EMT molecular sieve membrane

Abstract

The invention relates to a preparation method of an EMT molecular sieve membrane. The method comprises the following steps: 1, weighing an aluminum source, a silicon source, sodium hydroxide and a template agent according to a molar ratio of Al2O3: SiO2: Na2O: the template agent: H2O of 1:(1-50):(0.1-10):(0-1.0):(20-400), fully dissolving in deionized water, continuously stirring, standing, and aging to obtain a precursor sol; 2, immersing a pretreated ceramic support body into the precursor sol, coating the surface of the pretreated ceramic support body with the molecular sieve precursor solby adopting a vacuum filtration process, and then drying to obtain a ceramic support body coated with the molecular sieve precursor sol; and 3, putting the ceramic support body coated with the molecular sieve precursor sol into a reaction kettle with deionized water at the bottom, carrying out closed crystallization, washing, drying, roasting and activating to obtain the EMT molecular sieve membrane. Compared with the prior art, the EMT molecular sieve membrane prepared by the method has better deep removal performance when adsorbing polar oxygen-containing compound impurities in olefin flow.

Description

Technical field [0001] The invention belongs to the technical field of fine chemical inorganic membrane materials, and specifically relates to a preparation method and application of an EMT molecular sieve membrane. Background technique [0002] Molecular sieve membrane materials are favored due to their high temperature resistance, corrosion resistance, high mechanical strength, low mass transfer resistance, large flux and uniform and adjustable pore structure, etc., especially in the trace amounts of methanol and propylene in gaseous olefins. There are huge engineering application prospects in the field of deep purification of polar oxygenated compounds such as aldehydes, such as 13X molecular sieve membranes. [0003] EMT molecular sieve, a zeolite with a three-dimensional twelve-membered ring pore system and better than FAU topological structure, has a more developed pore structure and better surface properties. Compared with 13X molecular sieves, EMT molecular sieves have bet...

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Problems solved by technology

This patent proposes to prepare porous hollow fiber ceramic membranes with alumina as raw material, then use membrane pretreatment agents to pretreat the surface of ceramic membranes, and finally use secondary growth method to prepare multilayer EMT molecular sieves on the surface of ceramic membranes, and the prepared EMT Molecular sieve membrane has good separation performance of C8 aromatic isomers, but the yield of membrane preparation in this method cannot meet the requirements, and the utilization rate of raw materials in the preparation process of EMT molecular sieve membrane layer is low

Sankhanilay et al. reported that small particle EMT molecular sieves of 200 nm to 1 μm uniformly dispersed in water were used as seed crystals, and then coated on α-Al2O3 surface, finally hydrothermally crystallized in the gel with the same composition, washed, dried, and calcined to prepare an EMT molecular sieve membrane with a thickness of ~2μm, but This method is complicated to operate, takes a long time to make membranes, and also has the disadvantages of low raw material utilization (Sankhanilay Roy Chowdhury. [Synthesis and structural characterization of EMT-type membranes and their performance innanofiltration experiments]. Journal of membrane science, 2008, 314: 200 -205)

The harsh synthesis conditions, low raw material utilization and film formation rate of the hydrothermal crystallization method, as well as the poor structural integrity of the film caused by its homogeneous and heterogeneous nucleation (poor uniformity and continuity, cracked ), which seriously hinders the future industrialization progress of EMT molecular sieve membranes

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