A kind of preparation method of monolithic high silicon aluminum ratio nay molecular sieve

Abstract

The invention provides a preparation method of an integrated NaY molecular sieve with a high silica-alumina ratio. According to the method, the NaY molecular sieve is prepared by reaction of a formed reaction substrate. The method specifically comprises the following steps: preparing a NaY molecular sieve guiding agent according to a certain proportion, and stirring and aging for 4-10 hours at 20-40 DEG C; uniformly mixing and kneading materials such as a solid silicon source, metakaolin and the guiding agent and forming, filling the formed reaction substrate in a reaction kettle for crystallization, wherein the crystallization temperature is controlled at 100-150 DEG C and the crystallization time is 5-40 hours; and after reaction, filtering, washing and drying the product to obtain the NaY molecular sieve. The method which is used for synthesizing the integrated NaY molecular sieve in one step has the characteristics of high raw material utilization ratio, high product yield and the like. Moreover, the prepared integrated NaY molecular sieve is great in area and high in activity.

Description

technical field [0001] The invention belongs to the field of preparation of molecular sieves as inorganic catalytic carrier materials, and in particular relates to a preparation method of an integral high-silicon-aluminum ratio NaY molecular sieve. Background technique [0002] Y zeolite has a three-dimensional unobstructed pore structure, excellent thermal and hydrothermal stability, and is widely used in petroleum refining and chemical industries, especially in catalytic cracking (FCC) reactions. At the same time, Y-type molecular sieve also shows excellent performance on the adsorption of organic volatiles. [0003] At present, the methods for industrial production of Y-type molecular sieves basically adopt the directing agent method mentioned in USP3639099 and USP4166099 by GRACE Company of the United States, and the silicon-alumina ratio of the conventional Y-type molecular sieves produced is about 5. Y-type molecular sieves with high silicon-aluminum ratio widely used...

AI Technical Summary

Problems solved by technology

Y-type molecular sieves with high silicon-aluminum ratio widely used in heavy oil cracking catalysts are generally produced by post-treatment methods such as dealumination or dealumination and silicon supplementation, including high-temperature hydrothermal treatment adopted in USP3449370; The high-temperature gas-phase reaction method mentioned; the ammonium fluorosilicate liquid-phase reaction method reported in the literature and the complexation treatment method adopted in USP4093560; the Chinese patent CN1785808A synthesized a Y-type molecular sieve with a high silicon-aluminum ratio by segmental crystallization , but the reaction process requires a large amount of water, the silicon source utilization rate is not high, and a large amount of waste liquid needs to be treated in the later stage

[0004] U.S. Patent No. USP4493902 introduced a method for preparing NaY catalytic cracking catalyst using in-situ synthesis technology, that is, using kaolin microspheres as raw materials, on which NaY molecular sieves are produced by in-situ crystallization, but the bulk density of catalysts made by this method is Large, it is easy to cause adverse effects on the fluidized catalytic cracking process, and this catalyst does not have a mesopore structure

This technology has high requirements on raw materials, and requires the use of ultra-fine high soil SatoneNo.2 and ultra-fine raw soil ASP~600. This ultra-fine soil is expensive, and it is not easy to buy in the market.

[0005] The synthesis methods of the above Y-type molecular sieves all adopt the hydrothermal method. The reactants of the hydrothermal synthesis process are mainly solvent water, and the product needs to deal with a large amount of waste liquid during the synthesis process, which causes environmental pollution and increases the synthesis cost.

The water content in the reactant is 80-90%, while the final dry-based molecular sieve is only about 10%, and the product yield is low

On the other hand, in the process of hydrothermally synthesized Y-type molecular sieves being used as catalytic carrier materials, molecular sieves need to be treated multiple times, and the preparation steps are complicated, the crystallinity of molecular sieves is greatly lost, and the yield and environmental pollution are serious. The synthesized molecular sieve powder In the post-molding process, other components such as alumina binder should be added, which will reduce the utilization rate of molecular sieves and other disadvantages.

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