In-situ gas-phase method for preparing industrial zeolite catalyst

Abstract

The invention discloses a method for preparing an industrial zeolite catalyst by a vapor phase method in situ; a silicon source, an aluminum source, a natrium source and a shaping addition agent are mixed with de-ionized water to form alumino silica gel; then the alumino silica gel is shaped and dried to obtain the alumino silica gel grains with certain shape, intensity and hole channel structures; then the shaped alumino silica gel is arranged into a high pressure reaction kettle and is crystallized by the vapor phase method under the existence of a template; the product after the crystallization is filtered and washed to be neutral, then dried and baked to obtain the industrial zeolite catalyst. The method provided by the invention fundamentally changes the traditional preparation flows, uses the stroma body of the shaped alumino silica gel as the supporting carrier of the industrial zeolite catalyst, does not use an external carrier, crystallizes the outer surface of the stroma body of the alumino silica gel and the hole channel surface into the zeolite catalyst in situ, effectively improves the operating factor and the catalyzing performance of the catalyst, and solves the problem of adhering intensity between a substrate and a zeolite layer.

Description

technical field [0001] The invention relates to a preparation method of an industrial zeolite catalyst. It specifically relates to the in-situ preparation of industrial zeolite catalysts such as MCM-22 by a gas phase method. Background technique [0002] The preparation process of the traditional monolithic industrial zeolite catalyst is as follows: firstly, the raw zeolite powder is synthesized by hydrothermal method, then modified according to the reaction, and finally an adhesive is added, mixed, extruded, dried and calcined to become an industrial zeolite catalyst with certain strength and pore structure. The distribution of binders and active components in the granular and strip catalysts prepared in this way is random, and there are many binders without catalytic activity on the outer surface, which leads to the reduction of the utilization rate of the outer surface of the catalyst; The addition of the binder will affect the diffusion of the reaction molecules to a ce...

AI Technical Summary

Problems solved by technology

The method is simple, but it is difficult to achieve fine control of the zeolite structure

The secondary growth method combines in-situ hydrothermal synthesis and dip-coating method to separate the nucleation and growth of zeolite crystals, which can effectively control the size, orientation and film thickness of zeolite crystals, but the process is more complicated

Although many researchers use methods such as membrane modification and directional growth to improve the performance of zeolite membranes, there are still some problems in the synthesis, such as the problems of synthesis conditions and synthesis repeatability; the adhesion strength between the substrate and the zeolite layer is poor. ; The thickness and position of the film are difficult to adjust, etc.

Images