Hollow molecular sieve fiber and preparation method thereof

Abstract

The invention relates to a hollow molecular sieve fiber and a preparation method thereof. The external diameter of the hollow molecular sieve fiber is 1-30 mu m, the internal diameter is 0.5-20 mu m, the length-diameter ratio is 20:1-1000:1, and the specific area is 350-700 m<2> / g. The preparation method comprises the following steps: attaching a small amount of molecular sieve crystal seed to a solid silicon-oxygen-containing fiber used as a silicon source; and by using a steam reforming process, generating a molecular sieve film layer on the solid fiber surface, growing the molecular sieve microcrystal in the normal direction of the molecular sieve film surface, and finally, gradually emigrating the silicon source from inside to form the hollow fiber. The method is suitable for preparing ZSM-5-type, beta-type, Y-type, titanium-silicon-type and other molecular sieves. The preparation method is simple; and the product has the advantages of high purity, complete structure and high mechanical strength, and is suitable to be used as a film separation material or a catalyst for catalytic reaction.

Description

technical field [0001] The invention belongs to the technical field of molecular sieves and their preparation, and in particular relates to a hollow molecular sieve fiber and a preparation method thereof. Background technique [0002] Molecular sieves are a class of porous substances with regular channels and sizes, and are widely used in catalytic reaction processes and adsorption separation processes. According to the different skeleton structures, it can be divided into ZSM-5, β, Y, X, SAPO and other types. Such substances are generally generated by self-assembly under the action of a template agent under a hydrothermal environment using a Si source and an Al source. [0003] However, the molecular sieves prepared by most methods are nano- or micro-sized crystals, and generally the absolute size is not greater than 100 μm. In actual use, molecular sieves need to be molded together with other ingredients to make macroscopic particles. The presence of other components in...

AI Technical Summary

Problems solved by technology

Although this method is simple, only single-crystal hollow ZSM-5 molecular sieves can be obtained, and the requirements for the composition of the molecular sieves are relatively strict, and the morphology of the effective hollow structure cannot be controlled.

The mass loss of molecular sieve is large, and the preparation cost is high

At the same time, none of these methods can obtain a hollow molecular sieve structure with a large macroscopic size.

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