Preparation method for highly acid Y type molecular sieve

Abstract

The invention provides a preparation method for a highly acid Y type molecular sieve. The method comprises the following steps a, mixing a silicon source, an aluminum source, an alkali source and water and then carrying out ageing at a predetermined temperature so as to obtain a Y type molecular sieve guiding agent; b, mixing the Y type molecular sieve guiding agent, the silicon source and water at room temperature under stirring, then adding the aluminum source and the alkali source under stirring, carrying out crystallization at 90 to 110 DEG C for 12 to 48 h, and successively carrying out cooling, washing, pumping filtration and drying at 30 to 80 DEG C so as to obtain a NaY type molecular sieve; and c, treating the NaY type molecular sieve in an aqueous solution of an ammonium salt, then treating the NaY type molecular sieve in an acid solution, carrying out treatment in a solution containing cetyl trimethyl ammonium bromide, ammonia water and LaCl3 and then roasting the NaY type molecular sieve at 400 to 600 DEG C for 1 to 10 h so as to obtain the Y type molecular sieve. The preparation method provided by the invention is simple in process and low in cost, and prevents collapse of the crystal lattice of the molecular sieve and destroy of microporous channels while preparing the highly acid Y type molecular sieve with a high degree of crystallization.

Description

technical field [0001] The invention relates to a method for preparing strongly acidic Y-type molecular sieves, belonging to the field of catalyst preparation. Background technique [0002] Y-type molecular sieves have attracted widespread attention as the main active component of catalytic cracking catalysts. However, during heavy oil processing, the diffusion limitation brought about by its pore size of 0.74nm prevents heavy oil macromolecules from cracking effectively. Introducing mesoporous (2-50nm) into Y-type molecular sieve can reduce diffusion limitation, make heavy oil macromolecules easy to approach the active center of catalyst and effectively crack, and get more target products. Scholars at home and abroad have studied a variety of methods for synthesizing mesoporous molecular sieves, including the "bottom-up" direct synthesis method and the "top-down" post-processing method. [0003] CN102874836A discloses a method of synthesizing a mesoporous A-type molecular...

AI Technical Summary

Problems solved by technology

[0011] Removal of molecular sieve skeleton atoms can effectively form mesopores, but it will cause the collapse of molecular sieve lattice and the destruction of micropore channels

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