Phosphorus and rare earth synergistically modified ZSM-5 and method for increasing propylene yield through catalytic cracking by using phosphorus and rare earth synergistically modified ZSM-5

Abstract

The invention relates to phosphorus and rare earth synergistically modified ZSM-5. The phosphorus and rare earth synergistically modified ZSM-5 is composed of the following substances in percentages by mass: 1% to 5% of bentonite, 3% to 5% of titanium dioxide, 3% to 5% of calcium oxide, 2.5% to 3.8% of zinc oxide, 1.1% to 2.7% of copper oxide, 1% to 2.5% of a toughening modifier, 1.1% to 2.1% of acoupling agent, 5.5% to 15% of sepiolite, 4% to 6% of ethyl silicate, 3% to 9% of hollow glass beads, 20% to 35% of aluminum ash, 6% to 11% of quartz sand, 2% to 5% of sodium carbonate, 3.5% to 5.5%of phosphorus pentoxide and 1.1% to 4.8% of light rare earth, with the balance being a silica sol. The method for increasing propylene yield by catalysis comprises two steps, i.e., a step of raw material pretreatment and a step of material mixing. The phosphorus and rare earth synergistically modified ZSM-5 provided by the invention effectively improves the hydrothermal stability of a ZSM-5 molecular sieve, has high activity, long service life and good propylene selectivity, has good compounding effect with a catalytic cracking main catalyst in propylene production, can greatly improve the catalytic cracking conversion efficiency of raw materials, greatly increases the production efficiency of liquefied gas and the content of propylene in the liquefied gas, thereby achieving the purpose ofimproving the efficiency and quality of propylene production operation.

Description

technical field

[0001] The invention relates to a phosphorus and rare earth synergistically modified ZSM-5 and a method for increasing the production of propylene by catalytic cracking, belonging to the technical field of propylene production. 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, ...

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