Catalytic conversion method of propylene preparation

Abstract

The invention discloses a catalytic conversion method for producing propylene. Raw material which is difficult for cracking is contacted with a thermal regeneration catalyst, and cracking reaction is carried out under the conditions that the reaction temperature is 600 DEG C to 750 DEG C, the weight hourly space velocity is 100-800h<-1>, the reaction pressure is 0.10MPa to 1.0MPa, the weight ratio of the catalytic cracking catalyst and raw material is 30 to 150, and the weight ratio of steam and raw material is 0.05 to 1.0. The reaction material flow is mixed with raw oil which is easy to be cracked, and cracking reaction is carried out under the conditions that the reaction temperature is 450 DEG C to 620 DGE C, the weight hourly space velocity is 0.1-100 h<-1>, the reaction pressure is 0.10MPa to 1.0MPa, the weight ratio of the catalytic cracking catalyst and raw material is 1.0 to 3.0, and the weight ratio of the steam and raw material is 0.05 to 1.0; then a spent catalyst and reaction oil gas are separated, the spent catalyst returns to a reactor after regeneration, and the target products comprising propylene and recracking raw material are obtained by separating the reaction oil gas. By adopting the method of the invention, the yield of the propylene and the selectivity of the propylene in liquefied gas are increased greatly, moreover, the yield of dry gas is reduced obviously.

Description

technical field [0001] The invention belongs to a method for catalytic conversion of hydrocarbon oil in the absence of hydrogen, more specifically, a method for catalytic conversion of heavy raw materials into light olefins, especially propylene. Background technique [0002] Low-carbon olefins such as ethylene and propylene are important organic chemical raw materials, among which propylene is a synthetic monomer for products such as polypropylene and acrylonitrile. With the rapid growth of demand for derivatives such as polypropylene, the demand for propylene is also increasing year by year. The demand in the world propylene market has increased from 15.2 million tons 20 years ago to 51.2 million tons in 2000, with an average annual growth rate of 6.3%. It is estimated that the demand for propylene will reach 86 million tons by 2010, with an average annual growth rate of about 5.6%. [0003] The methods for producing propylene are mainly steam cracking and catalytic crac...

AI Technical Summary

Problems solved by technology

[0009] The above-mentioned prior art still has deficiencies in the design of the alkane molecular cracking reaction, resulting in a substantial increase in the dry gas yield when the propylene yield is increased. At the same time, the product distribution of the prior art is cut according to the conventional FCC fractionation system. The potential content of aromatics and low-carbon olefins in gasoline or diesel is not fully utilized, resulting in low propylene yield

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