A kind of preparation method of nay molecular sieve

Abstract

The invention discloses a method for preparing a NaY molecular sieve. The method comprises the following steps: a, uniformly mixing a guiding agent, a silicon source, an aluminum source and water so as to obtain a silicon-aluminum gel mixture, wherein the silicon-aluminum gel mixture contains Na2O, Al2O3, SiO2 and H2O in a mole ratio of oxides of (1.5-10):1:(5-18):(100-500); b, filtering the silicon-aluminum gel mixture obtained in the step a so as to obtain gel filter cakes; c, performing crystallization treatment on the gel filter cakes obtained in the step b so as to obtain a crystallization product; and d, washing and drying the crystallization product obtained in the step c, thereby obtaining the NaY molecular sieve. As the silicon-aluminum gel is filtered and washed before crystallization, the single kettle yield of synthesis of the NaY molecular sieve is increased, the energy consumption in heating for synthesizing gel is reduced, impurity ions in synthesized gel can be removed, direct recycling of crystallization mother liquor is facilitated, and clean production of the NaY molecular sieve is achieved.

Description

technical field [0001] The invention relates to a preparation method of NaY molecular sieve. Background technique [0002] As a catalyst active component or catalyst carrier, Y-type molecular sieve can be widely used in refining and chemical processes such as catalytic cracking, hydrocracking and isomerization, and is currently the most used zeolite material. NaY molecular sieve, as the raw material of petroleum cracking catalyst, generally requires its silicon-aluminum ratio to be greater than 5.0 in order to maintain sufficient hydrothermal stability during use. At present, the method for industrially producing NaY molecular sieves basically adopts the directing agent method proposed by the U.S. GRACE company (U.S. Patent No. NaY molecular sieves were prepared by thermal crystallization. The preparation method that US3639099 proposes is because the feeding basicity is bigger, and the silicon-aluminum ratio of the prepared NaY molecular sieve is generally 4.0-4.5; And whe...

AI Technical Summary

Problems solved by technology

At present, most of the industry adopts the method proposed in US3671191 to produce NaY molecular sieves, but there are problems in that the amount of feed water is high, the ratio of feed silicon to aluminum is high, and the utilization rate of silicon sources is low, which makes the single-pot yield of the product low.

However, this method takes a long time to depolymerize silica gel, and the preparation process of synthetic gel is relatively complicated, and the synthesized NaY crystal grains are relatively small, only 200nm-400nm

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