Zn-ZSM-5/ZSM-11 catalyst, preparation method thereof and method for producing aromatic hydrocarbon

Abstract

The invention provides a Zn-ZSM-5 / ZSM-11 catalyst, a preparation method thereof and a method for producing aromatic hydrocarbon. The preparation method of the Zn-ZSM-5 / ZSM-11 catalyst comprises the following steps: (1) adding a silicon source and an alkali raw material into water to obtain a mixed solution A; (2) adding an aluminum source, a template agent and a zinc source into the mixed solution A, and refluxing a reaction system at 80-150 DEG C for 2-8 hours to obtain a mixed solution B; (3) carrying out crystallization reaction on the mixed solution B at 130-170 DEG C for 18-96 hours to obtain a mixed solution C; (4) cooling the mixed solution C to room temperature, filtering, washing and drying, and performing first roasting treatment on an obtained solid product to obtain a catalyst precursor; and (5) carrying out ammonium exchange on the catalyst precursor, and carrying out second roasting treatment on an exchange product to obtain the Zn-ZSM-5 / ZSM-11 catalyst. The Zn-ZSM-5 / ZSM-11 catalyst with good catalytic performance can be prepared, and the Zn-ZSM-5 / ZSM-11 catalyst has the advantages of simple process, high efficiency and the like.

Description

technical field [0001] The invention relates to a Zn-ZSM-5 / ZSM-11 catalyst, a preparation method thereof, and a method for producing aromatic hydrocarbons. The catalyst is especially useful for catalyzing the aromatization reaction of methanol coupled with light hydrocarbons. Background technique [0002] As an important basic chemical raw material, the demand for aromatics continues to grow, and more than 85% of aromatics in my country comes from the production process of petroleum routes, and aromatics preparation technology has also developed rapidly. [0003] Light hydrocarbons (such as reformed top oil, raffinate, etc. produced during petroleum processing) are by-products of refineries with low added value, and are usually used as raw materials for the production of ethylene and propylene. Lightening, the utilization of light hydrocarbons is limited to a certain extent, and it is difficult to exert its application value, and light hydrocarbon aromatization technology pr...

AI Technical Summary

Problems solved by technology

[0006] Zinc element (Zn) contributes to the aromatization function, and the introduction of zinc element into some molecular sieves can make it show a catalytic effect on the aromatization reaction to a certain extent, but the traditional way of introducing Zn is to prepare molecular sieves first and then The step of carrying out zinc element loading, the preparation process is relatively complicated, and the catalytic performance of the prepared catalyst is limited

At present, ZSM-5 / ZSM-11 eutectic molecular sieve catalysts (Zn-ZSM-5 / ZSM-11 catalysts) loaded with Zn are synthesized in situ by one-step method and used to catalyze the aromatization of methanol-coupled light hydrocarbons. The reaction has not been reported yet. In order to broaden the catalysts for the aromatization reaction of methanol coupled with light hydrocarbons, and solve a series of problems such as harsh aromatization conditions at the present stage, easy carbon deposition and deactivation of the catalyst, and low product yield / poor selectivity, the optimized Synthetic technology and development of novel aromatization catalysts are important issues faced by those skilled in the art

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