Method for regulating ZSM-5 molecular sieve morphology

Abstract

The invention provides a method for regulating a ZSM-5 molecular sieve by using phosphorus species through aerosol auxiliary synthesis. According to the method, an aluminum source, a silicon source, water and a phosphorus source are mixed; an obtained mixture is uniformly stirred to form mixed liquid; aerosol is formed through an aerosol device; drying is performed to obtain amorphous form silicon aluminum phosphorus oxide; the silicon aluminum phosphorus oxide and a tetrapropylammonium hydroxide water solution are mixed; sealing is performed; crystallization is performed at 100 to 200 DEG C, wherein the crystallization time is 3h to 240h; obtained solid products are washed and dried or are directly dried to be roasted; the ZSM-5 molecular sieve is obtained. By the method, the precise regulation on the ZSM-5 molecular sieve morphology can be realized. The method has the advantages that the regulation process is simple; the template agent consumption is low; the pollution is small; the yield is high; good industrial application prospects are realized.

Description

technical field [0001] The invention relates to the technical field of ZSM-5 molecular sieves, in particular to aerosol-assisted synthesis and a method for adjusting the morphology of ZSM-5 molecular sieves by using phosphorus species. Background technique [0002] ZSM-5 molecular sieve is a high-silica zeolite with a three-dimensional cross-channel system invented by Mobil Corporation of the United States. It has good thermal stability, hydrothermal stability and acid resistance. It is mainly used in catalytic cracking, toluene disproportionation, benzene and toluene Alkylation, alkylation of low-carbon aromatics and other important traditional petrochemical fields. At the same time, ZSM-5 molecular sieve is also an important catalyst in coal chemical industry such as methanol to olefins, methanol to gasoline, methanol to aromatics, etc., and can also be used in automobile exhaust treatment (SCR technology) in the field of environmental protection. [0003] At present, the...

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Problems solved by technology

But these methods still have some problems

First of all, these adjustment methods are mainly based on the traditional hydrothermal synthesis of ZSM-5 molecular sieves, which have the problems of large amount of template agent, high crystallization temperature, low utilization rate of single kettle, and more waste liquid discharge; secondly, increasing The amount of template agent or adding seeds to prolong the crystallization time will greatly increase the synthesis cost of ZSM-5 molecular sieves, and will also generate more waste; the method of adding electrolytes, the operable range of the amount of electrolytes is relatively small Small, too large or too small will not have the corresponding effect; to adjust the degree of polymerization of the silicon source and aluminum source in the reaction raw materials, usually add water or acid during the synthesis, which reduces the basicity of ZSM-5 molecular sieve synthesis, Thereby it will affect the quality and yield of ZSM-5 molecular sieve

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