Phosphor and rare earth composite modification method of molecular sieve

Abstract

A phosphor and rare earth composite modification method of a molecular sieve comprises that an aluminum source on the surface of the molecular sieve is utilized for in situ synthesis of carbonate-ion-pillared Zn (Mg) / Al / La (Ce) ternary hydrotalcite; that dihydrogen-phosphate-ion-pillared hydrotalcite is prepared by employing an ion exchange method; and that a program heating calcination method is used to make P2O5, La2O3 or Ce2O3 be highly dispersed in the surfaces and pores of the molecular sieve, thereby improving the acidity of the molecular sieve. According to the method of the invention, the molecular sieve modified by hydrotalcite precursor method not only realizes high dispersion of active components, but also greatly improves the acidity and the stability of the molecular sieve, thereby providing a material with practical application values for preparing catalyst for catalytic cracking of heavy oil.

Description

technical field [0001] The invention relates to a phosphorus and rare earth compound modification method of molecular sieves, in particular to a modification method in which hydrotalcite precursors are produced in molecular sieves. Background technique [0002] The availability of conventional petroleum resources is decreasing day by day, and the processing of heavy oil and residual oil is receiving more and more attention. Heavy oil is characterized by large molecules and complex molecular structures. Moreover, heavy oil is enriched with most of the sulfur, nitrogen and metal compounds in crude oil. These compounds are not only difficult to crack and easy to form coke, but also deposited on the surface of the catalyst are very easy to poison the catalyst and lose its activity. [0003] Based on the above characteristics of heavy oil, the selection of molecular sieve type and the modification of molecular sieve are very important in heavy oil catalytic cracking, which are d...

AI Technical Summary

Problems solved by technology

The disadvantage of this method is that if synthesized at high temperature, AlO 4 -5 grows well on the outer layer of ZSM-5, which easily leads to AlO 4 -5 independent crystallization, it is difficult to form a core / shell molecular sieve in the true sense; if synthesized at low temperature, AlO 4 -5 has a long crystallization time, resulting in excessive consumption

[0034] The above research is to first synthesize binary hydrotalcite, and then prepare a single active component catalyst, but in some reactions that require the simultaneous presence of multiple active components, the above method obviously has shortcomings

Images