Catalyst for preparing propylene through dehydrogenation of propane and preparation method of catalyst

Abstract

The invention relates to a catalyst for preparing propylene through dehydrogenation of propane and a preparation method of the catalyst. The preparation method comprises the steps: preparing a NaZSM-5molecular sieve with a conventional microporous structure, then placing the obtained NaZSM-5 molecular sieve in a mixed solution of an alkali solution with a templating agent, performing microwave hydrothermal crystallization, performing exchange with an appropriate amount of inorganic acid or an ammonium salt solution, conducting calcination so as to obtain an HZSM-5 molecular sieve with a microporous-mesoporous multi-stage pore structure, and then loading active components and auxiliary agents on the multi-stage pore HZSM-5 molecular sieve so as to obtain the catalyst. When the preparationmethod is compared with the prior art, a mesoporous structure is introduced in the microporous structure of the ZSM-5 molecular sieve, so that the problem of difficult molecular diffusion is solved, the occurrence of carbon deposition is reduced, and the service life of the catalyst is prolonged; meanwhile, through secondary microwave crystallization, reduction of the crystallization temperature and shortening of the time of the entire synthesis process are achieved, and re-migrating of the removed non-framework species to the skeleton is achieved, so that the crystallinity of the ZSM-5 molecular sieve is improved; when the catalyst is applied to a preparation reaction of propylene through dehydrogenation of propane, a high conversion rate of propane and high selectivity to propylene are obtained.

Description

Technical field [0001] The invention relates to the technical field of propane dehydrogenation to propylene, in particular to a catalyst for propane dehydrogenation to propylene and a preparation method thereof. Background technique [0002] In recent years, the world economy has developed rapidly, and the chemical industry, as an important part of the national economy, has also developed by leaps and bounds. This has led to the continuous increase in the demand for propylene downstream products and thus the acceleration of the demand for propylene. Propylene is an important chemical basic raw material second only to ethylene, and its downstream derivatives mainly include polypropylene, acrylonitrile, acetone, isopropanol, phenol, butanol, octanol, acrylic acid, etc. In particular, as polypropylene, which has the characteristics of heat resistance, light weight, and good strength, is widely used in packaging, home appliances, automobiles, and construction, the demand for polyprop...

AI Technical Summary

Problems solved by technology

There are also patents that use the third or fourth component to modify the Pt-Sn / HZSM-5 catalyst, and pay less attention to the modulation of the structure of the ZSM-5 molecular sieve carrier itself

Typical ZSM-5 molecular sieve channels are in the range of micropores, and the channel structure is not conducive to the diffusion of reactants and products. In the high-temperature environment of propane dehydrogenation, it is easy to generate carbon deposits and cause catalyst deactivation.

Images