Preparation method of rare earth modified hierarchical porous ZSM-5 molecular sieve for yield increase of propylene

Abstract

The invention relates to a preparation method of a rare earth modified hierarchical porous ZSM-5 molecular sieve for yield increase of propylene. The preparation method comprises four steps of material mixing, material modulation, molding processing and modification molding. The preparation method is low in raw material cost, small in toxic and side effects, simple in processing and production process, low in production cost and small in environmental pollution. On one hand, the hydrothermal stability of the ZSM-5 molecular sieve is effectively improved, the activity is high, the service lifeis long, and the propylene selectivity is good; on the other hand, the compounding effect between the ZSM-5 molecular sieve and a catalytic cracking main catalyst in propylene production is good, so that the catalytic cracking conversion efficiency of the raw material can be greatly improved, and the liquefied gas production efficiency and the propylene content in liquefied gas are greatly improved.

Description

technical field [0001] The invention relates to a catalyst production technology, in particular to a preparation method of a rare earth modified multi-stage pore ZSM-5 molecular sieve for increasing the production of propylene. Background technique [0002] At present, in the production of propylene, ZSM-5 molecular sieve is one of the important catalysts to improve the production efficiency and quality of propylene, whether it is directly using raw material hydrocarbon oil or based on raw materials such as methanol for cracking, decomposition and conversion to produce propylene. In actual use, it is found that the currently used ZSM-5 molecular sieve is often in the traditional ZSM-5 molecular sieve structure, although it can meet the needs of use to a certain extent, but on the one hand, there is poor activity of ZSM-5 molecular sieve, short service life, and ZSM-5 molecular sieve has less surface voids and poor selectivity to propylene. On the other hand, the currently us...

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Problems solved by technology

[0002] At present, in the production of propylene, ZSM-5 molecular sieve is one of the important catalysts to improve the production efficiency and quality of propylene, whether it is directly using raw material hydrocarbon oil or based on raw materials such as methanol for cracking, decomposition and conversion to produce propylene. In actual use, it is found that the currently used ZSM-5 molecular sieve is often in the traditional ZSM-5 molecular sieve structure, although it can meet the needs of use to a certain extent, but on the one hand, there is poor activity of ZSM-5 molecular sieve, short service life, and ZSM-5 molecular sieve has less surface voids and poor selectivity to propylene. On the other hand, the currently used ZSM-5 molecular sieve also has poor recombination with the catalytic cracking main catalyst produced by propylene, which seriously affects the catalytic cracking main catalyst. Catalytic Cracking Efficiency

[0003] In response to this problem, a large number of ZSM-5 molecular sieves based on phosphorus modification and rare earth modification have been developed. Although the production efficiency of propylene has been improved to a certain extent, the modified ZSM-5 molecular sieves are used to varying degrees. There are disadvantages of short life and poor hydrothermal stability, which lead to high cost of use of ZSM-5 molecular sieve, and easily affect the quality of propylene products

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