Preparation method of non-binder ZSM-5/zeolite beta coexisting molecular sieve catalyst

Abstract

The invention relates to a preparation method of a non-binder ZSM-5 / zeolite beta coexisting molecular sieve catalyst. In the invention, the problems that when a hydrothermal synthesis method is adopted to prepare the existing ZSM-5 / zeolite beta coexisting molecular sieve, the preparation process is complicated, the cost is higher, the ZSM-5 / zeolite beta coexisting molecular sieve catalyst with the binder has lower activity, the non-binder ZSM-5 / zeolite beta coexisting molecular sieve has lower strength and the mechanical mixture of ZSM-5 with the binder and zeolite beta has lower activity, are mainly solved. The technical scheme in the invention comprises the following steps: mixing ZSM-5 / zeolite beta coexisting molecular sieve, alkaline substance, aluminum compound and silicon oxide, forming, drying, placing the dried mixture in template agent vapor containing at least one of ammonia water, ethylenediamine, triethylamine, n-butylamine, hexanediamine, tetrapropylammonium bromide or tetrapropylammonium hydroxide, and tetraethylammonium hydroxide or tetraethylammonium bromide to perform crystallization treatment at 100-200 DEG C for 10-300 hours and obtain the non-binder ZSM-5 / zeolite beta coexisting molecular sieve catalyst, wherein the weight contents of ZSM-5 / Magadiite coexisting molecular sieve, alkaline substance, aluminum compound and silicon oxide calculated according to the weight of the formed and roasted catalyst are 10-80%, 0.1-10%, 0.5-20%, and 20-80% respectively. The problems can be better solved and the prepared non-binder ZSM-5 / zeolite beta coexisting molecular sieve catalyst can be used in the naphtha catalytic cracking reaction for preparing propylene.

Description

technical field [0001] The invention relates to a preparation method of a binder-free ZSM-5 / beta zeolite symbiotic molecular sieve catalyst. Background technique [0002] Molecular sieves are widely used in petrochemical and other fields because of their uniform and regular pore structure, large specific surface area and high thermal stability, and good shape-selective catalytic performance and adsorption performance. Because molecular sieve powder itself has low strength and is easy to disperse and lose, it cannot be directly applied in industry. Therefore, it is necessary to add a binder during molding to increase the strength. In the molded catalyst, because the binder wraps the molecular sieve, resulting in The effective utilization rate of molecular sieves decreases, and the pores of some molecular sieves are blocked, resulting in low specific surface area and low activity of the catalyst. Because the binder has an irregular pore structure, it is difficult for the react...

AI Technical Summary

Problems solved by technology

[0011] The technical problem to be solved by the present invention is that the hydrothermal synthesis method is used in the preparation process of the existing ZSM-5 / β zeolite symbiotic molecular sieve, the preparation process is complicated and the cost is high, and when the ZSM-5 / β zeolite symbiotic molecular sieve catalyst contains a binder Problems with lower activity, lower strength of ZSM-5 / beta zeolite intergrown molecular sieve without binder, and lower activity of mechanical mixture of ZSM-5 and beta zeolite with binder

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