Method for preparing high-performance Silicalite-1 molecular sieve membrane in super-dilute synthetic fluid

Abstract

The invention relates to a method for preparing a high-performance Silicalite-1 molecular sieve membrane in super-dilute synthetic fluid, comprising the following steps: using low-cost silica solutionas a synthesis material to prepare a Silicalite-1 molecular sieve crystal with high activity, using the Silicalite-1 molecular sieve crystal as a seed crystal and loading the seed crystal on the surface of a support body, and preparing the high-performance Silicalite-1 molecular sieve membrane on a mullite support body using super- diliute synthetic fluid (H2O / SiO2=200-200). The invention not only effectively improves the performance of the Silicalite-1 molecular sieve membrane, but also greatly reduces the requirement of silicon source and template agent in the membrane synthetic fluid and greatly reduces the preparation cost of membrane. The membrane can be widely used for occasions of high-temperature fluid separation, gas separation, membrane reactors, and the like. The invention remarkable improves the flux penetration and the selectivity of the Silicalite-1 molecular sieve membrane, reduces the production cost and is suitable for industrial production.

Description

technical field [0001] The invention provides a kind of self-made highly active Silicalite-1 molecular sieve as crystal seed, adopts ultra-dilute synthetic liquid (H 2 O / SiO 2 =500-2000), a method for rapidly forming a layer of Silicalite-1 molecular sieve crystals on the outer surface of the porous mullite tube. It belongs to the field of permeation separation of inorganic materials. Background technique [0002] In recent years, the research on the preparation and application of molecular sieve membranes has received extensive attention. Zeolite membranes can not only be used for the dehydration of organic solvents, but also show good separation performance in the recovery of low-concentration organics in aqueous solutions. Compared with organic membranes, molecular sieve membranes not only have many advantages such as high temperature resistance, good chemical stability, and high mechanical strength, but also have good separation selectivity and large permeation. resea...

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Problems solved by technology

Many scientific research institutions in my country, such as Tsinghua University, Peking University, Fudan University, Zhejiang University, Nanjing University of Technology, Tianjin University, Dalian University of Technology, etc. agent, or the flux and separation factor of the synthetic membrane are low, and its industrialization cannot be realized

[0006] In the existing reports, the Silicalite-1 molecular sieve membranes investigated by the researchers were prepared at lower H 2 O / SiO 2 Molar ratio of synthetic solution prepared in H 2 O / SiO 2 Sols higher than 300 have not yet reported the performance of synthetic films, while in H 2 O / SiO 2 The synthesis in the sol higher than 500 has not been reported in the literature

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