A kind of zsm-5/mcm-48 composite molecular sieve and its preparation method and application

Abstract

The invention relates to methanol-to-gasoline catalysts, in particular to a ZSM-5 / MCM-48 composite molecular sieve, a preparation method and application thereof. The composite molecular sieve adopts a ZSM-5 microporous molecular sieve as the seed crystal, on the surface of which a MCM-48 mesoporous structure composite molecular sieve that is chemically interlinked at a mesoporous and micropore interface is obtained by overgrowth. The composite molecular sieve undergoes acidification, and then is mixed with a binder to undergo molding and roasting, and the product is used as a catalyst for methanol-to-gasoline (MTG) reaction. The catalyst provided by the invention is used for overgrowth of the mesoporous molecular sieve on the microporous molecular sieve surface, integrates the advantages of the microporous material and the mesoporous material so as to develop the strong points and avoid the weak points and reach a synergistic effect. The catalyst shows good catalytic properties to the methanol-to-gasoline (MTG) reaction, has high selectivity to gasoline products and a low aromatic hydrocarbon content, and extends the carbon chain length. More importantly, the problems of high reaction temperature, high aromatic hydrocarbon content in oil products, and limitation of hydrocarbon compounds only to less than C11 in traditional MTG technologies are solved.

Description

technical field [0001] The invention relates to a catalyst for methanol-to-gasoline, in particular to a ZSM-5 / MCM-48 composite molecular sieve and its preparation method and application. Background technique [0002] As we all know, microporous zeolite molecular sieve has become an important shape-selective catalyst in modern petrochemical industry because of its good molecular shape selectivity and acid catalytic performance. However, its narrow pore structure affects the rapid diffusion and overflow of macromolecular products, thus limiting the distribution of products. With the gradual increase in oil quality, the limitation of the pore size of microporous molecular sieves has become more prominent. Therefore, solving the problem of reaction and diffusion of macromolecules has become one of the most important technical issues in the field of petroleum processing in the world. [0003] In recent years, Al-containing mesoporous molecular sieves have attracted attention as ...

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Problems solved by technology

We previously disclosed a ZSM-5 / MCM-48 molecular sieve-based catalyst prepared by a two-step crystallization method and its use in methanol to gasoline reaction (Chinese invention patent application number: 201110195525.1), but there are still catalyst preparation The process is cumbersome, the cost is high, and the reaction product needs to be further adjusted.

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