Method for in situ synthesis of NaY molecular sieve rich in meso-pores

Abstract

The invention provides a method for in situ synthesis of a NaY molecular sieve rich in meso-pores. The method comprises the following steps: mixing kaolin with Na2CO3, calcining the obtained mixture at 300-1200 DEG C under a nitrogen condition for 2-15 h to obtain an aluminum source, adding a silicon source, sodium hydroxide, water and a directing agent, and performing uniform mixing at room temperature to obtain a NaY molecular sieve synthesis solution, wherein a molar ratio of Na2O:Al2O3:SiO2:H2O in the synthesis solution system is (3-15):(1-5):(5-25):(80-380); and ageing the synthesis solution at room temperature for 0-5 h, heating the aged synthesis solution to 80-120 DEG C, crystallizing the synthesis solution for 16-60 h, and performing suction filtration, washing and drying on the obtained solid product after the crystallization ends in order to synthesize the NaY molecular sieve rich in meso-pores. The molecular sieve obtained through the method has a larger total pore volume,a larger meso-pore volume and a larger average pore diameter than conventional NaY molecular sieves, and also has the advantages of high pore permeability, long active period. strong resistance to heavy metal pollution, and broad application prospect in the petrochemical field.

Description

technical field [0001] The invention relates to a method for in-situ synthesis of rich mesoporous NaY molecular sieves. technical background [0002] As an important industrial material, NaY molecular sieves are widely used in petrochemical fields, such as: catalytic cracking, catalytic hydrogenation, hydrocracking, isomerization and disproportionation reactions. Therefore, with the continuous development of petrochemical technology, more and more attention has been paid to the research on NaY molecular sieves. [0003] The synthesis of traditional NaY molecular sieves mostly adopts the gel method, that is, relatively pure industrial raw materials (water glass, aluminum sulfate, sodium aluminate, guiding agent) are used for hydrothermal synthesis. This method is relatively simple, and the synthesized NaY molecular sieve has better crystallinity and a relatively ideal silicon-aluminum ratio; but the cost of this method is relatively high. In the case of increasing industrial...

AI Technical Summary

Problems solved by technology

[0014] The object of the present invention is to develop a kind of synthetic method rich in mesoporous NaY for the existing problems and defects of the above-mentioned prior art, so that the prepared NaY molecular sieve has higher mesoporous structure, external specific surface area and crystallinity, Thus solving the problem that NaY molecular sieve mesoporous pore volume, external specific surface area and crystallinity cannot be balanced