A synthetic method of a nanometer HZSM-5 molecular sieve catalyst

Abstract

A synthetic method of a nanometer HZSM-5 molecular sieve catalyst is disclosed. Tetraethyl orthosilicate is adopted as a silicon source, aluminium nitrate nonahydrate, sodium aluminate or aluminium isopropoxide is adopted as an aluminum source, tetrapropylammonium hydroxide and tetrapropylammonium bromide are adopted as templates, sodium hydroxide is adopted as an inorganic base and deionized water is adopted. The method include steps of (1) ageing; (2) crystallizing; (3) performing centrifugal drying; (4) performing calcination to obtain a Na type nanometer ZSM-5 molecular sieve catalyst; (5) performing ion exchanging; (6) performing centrifugal drying; and (7) performing calcination to obtain the nanometer HZSM-5 molecular sieve catalyst. Steps and components of the method are clear, the method is convenient to operate, and the nanometer HZSM-5 molecular sieve catalyst which is spherical, uniform in particle, dispersed and free of agglomeration and the grain diameter of which is 50-70 nm can be synthesized by the method. The method positively promotes techniques of preparing olefins from methanol, and has positive significance for overcoming a propylene shortage problem.

Description

technical field [0001] The invention relates to the technical field of catalyst preparation, in particular to a synthesis method for preparing nanometer HZSM-5 molecular sieve catalysts with different silicon-aluminum ratios by a hydrothermal synthesis method. Background technique [0002] The technology of using coal or natural gas to produce low-carbon olefins such as ethylene and propylene through methanol began in 1976. Some large foreign petrochemical companies, such as UOP and ExxonMobil, have been researching methanol-to-olefins technology. Propylene is one of the most important organic raw materials, mainly used in the production of chemical products such as polypropylene, acrylonitrile, propylene oxide, cumene, butanol and octanol. With the continuous and rapid development of my country's economy, the demand for propylene and its downstream products is on the rise. Therefore, the problem of propylene shortage is becoming increasingly apparent. From the perspective...

AI Technical Summary

Problems solved by technology

The time of the synthesized small-grain ZSM-5 molecular sieve catalysts is relatively long, the synthesis conditions are relatively harsh, and the agglomeration phenomenon between the small grains is relatively serious

In addition, when preparing micron ZSM-5 molecular sieve catalysts, people usually discuss the influence of silicon-alumina ratio, but the influence of silicon-alumina ratio is rarely discussed when preparing nano-sized ZSM-5 molecular sieve catalysts

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