Preparation method and application of hierarchical porous ZSM-5 molecular sieve

Abstract

The invention provides a preparation method for a hierarchical porous ZSM-5 molecular sieve. According to the preparation method for the hierarchical porous ZSM-5 molecular sieve, in a synthesis system of a silicon source, an aluminum source, an organic structure directing agent and deionized water, a proper amount of cationic surfactant cetyl trimethyl ammonium bromide is added to serve as a softtemplate agent, full stirring and uniform mixing are carried out so as to form molecular sieve synthesis sol-gel, then the sol-gel is dried so as to obtain dry glue, and then the hierarchical porousZSM-5 molecular sieve is prepared by using a dry glue conversion method. The preparation method for the hierarchical porous ZSM-5 molecular sieve has the advantages of being mild in preparation conditions, simple, convenient to use, high in efficiency, free of emission of synthetic waste liquid, environmentally friendly and capable of realizing industrial production, the good catalytic performanceis realized in the reaction of preparing the low-carbon olefins through catalytic cracking of n-octane, and therefore, remarkable environmental benefits and economic benefits can be achieved, and theindustrial production prospect is good.

Description

technical field [0001] The invention belongs to the technical field of zeolite molecular sieve synthesis, and in particular relates to a method for synthesizing a multi-stage pore ZSM-5 molecular sieve, and uses the prepared multi-stage pore molecular sieve as a catalyst for catalytic cracking of hydrocarbons to produce low-carbon olefins. Background technique [0002] Low-carbon olefins such as ethylene and propylene are the most basic raw materials in the chemical industry. With the rapid development of my country's national economy, the market demand for low-carbon olefins is increasing day by day, so the research and development of new and efficient low-carbon olefins preparation technology has attracted more and more attention. At present, the production technologies of low-carbon olefins mainly include steam thermal cracking, catalytic cracking, methanol to olefins, olefins disproportionation, propane dehydrogenation and Fischer-Tropsch synthesis. Among the above proc...

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Problems solved by technology

However, the synthesis method of multi-stage pore ZSM-5 molecular sieve is relatively complicated, the preparation conditions of high temperature and high pressure are harsh, the single-pot synthesis efficiency is low, and a large amount of synthetic waste liquid is discharged, which greatly limits the industrial production of multi-stage pore ZSM-5 molecular sieve. application

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