Double-micropore zeolites and method of making thereof

Abstract

A kind of double microporous zeolite and preparation method thereof belong to the technical field of fine chemical industry, it is characterized in that adopting two-step crystallization method, the first step first synthesizes Beta, then with the synthetic Beta reaction mixture as the raw material of the second step synthesizing Y zeolite, The composite zeolite product with BEA / FAU structure is obtained by supplementing the aluminum source, adjusting the basicity of the system, adding the directing agent for synthesizing Y zeolite for reaction crystallization, filtering, washing, drying, and calcining. The method successfully solves the problems of pouring part of the clear liquid and difficult control of the amount of aluminum source and base added in the synthesis because the clear liquid contains components such as silicon, aluminum and alkali, and the product repeatability is difficult to control. The synthesized Beta / Y composite zeolite products can be used as various catalysts, catalyst assistants and adsorbents. After ion exchange, they have strong acidity and good thermal and hydrothermal stability. They can be used as various catalysts, catalyst assistants It is bound to have potential application value in catalytic cracking and hydrocracking of petrochemical industry.

Description

1. Technical field [0001] The invention relates to a double-microporous zeolite and a preparation method thereof, which belong to the technical field of fine chemicals, and specifically relate to a two-step crystallization method to organically combine two microporous zeolites of Beta and Y to form a double-microporous zeolite. A technical solution for a new type of zeolite material with a microporous structure. 2. Technical background [0002] Y-type molecular sieves and their modified products show excellent catalytic performance in reactions such as catalytic cracking, hydrocracking, hydroisomerization, alkane aromatization, and alkylation (M.A.Saberi, R.Le Van Mao, M.A. . Martin, A.W.H. Mak. Applicd Catalysis A: General 214 (2001); I.P. Dzikh, J.M. Lopes, F. Lemos, F. Ribeiro.CatalysisToday 65(2001); Wei Ruiping, Wang Jun, Ren Xiaoqian, etc. Journal of Inorganic Chemistry. 12(2004); A.M.Radwan, zhang-GuoZhang, P.Chambrion, et al.Fuel Processing Technology 55(1998).), i...

AI Technical Summary

Problems solved by technology

Our research group adopted two-step crystallization and successfully prepared a double-microporous molecular sieve (patent authorization number: ZL200410012333.2) that organically combines Y and Beta zeolites. It is characterized in that the zeolite synthesized in the first step is used as the second During the two-step synthesis of raw materials, it is required to pour part of the clear liquid. Since the clear liquid contains silicon, aluminum, alkali and other components, it is difficult to control the amount of aluminum source and alkali added in the second step of synthesis, resulting in the synthesis of double micropores. The repeatability of molecular sieve is not easy to control

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