Hydrocarbon catalytic conversion method for increasing propylene yield

Abstract

A hydrocarbon catalytic conversion method for increasing propylene yield comprises the following steps: contacting a hydrocarbon raw material with a catalyst in a catalytic cracking reaction zone, contacting the obtained butylene-enriched C-4 fraction and / or olefin-enriched gasoline fraction with a catalyst with micropore modification in an oligomerization / cracking reaction zone to perform an oligomerization cracking reaction, separating to obtain a product rich in propylene, performing steam stripping and regeneration of the carbon deposited catalyst, dividing the carbon deposited catalyst into two parts, delivering one part to the catalytic cracking reaction zone for recycle, delivering the other part to a catalyst micropore modification zone, contacting and reacting with a modifier, and then delivering to the oligomerization / cracking reaction zone for recycle. According to the invention, with the method of micropore modification of the catalyst, the catalytic cracking catalyst containing dual active components of macroporous zeolites and medium pore zeolites is provided with not only high heavy oil conversion capability and high propylene selectivity for catalytic cracking of heavy hydrocarbon raw materials, but also high propylene selectivity for catalytic conversion of butylene and high-alkene gasoline, and thus the purpose of increasing propylene yield is reached.

Description

technical field [0001] The invention relates to a method for catalytic conversion of hydrocarbons, more specifically, the invention relates to a method for catalytically cracking hydrocarbon feedstock oil in a composite reactor to obtain high propylene yield. Background technique [0002] Low-carbon olefins represented by ethylene and propylene are the most basic chemical raw materials. The traditional method of producing low-carbon olefins from petroleum hydrocarbons is steam thermal cracking. The suitable raw materials are ethane, propane, butane, natural gas, and naphtha. For light petroleum hydrocarbons such as oil or light diesel oil, the propylene / ethylene ratio cannot meet the market demand. While catalytic cracking of heavy oil produces gasoline and diesel oil, a certain amount of propylene is also by-produced, but its yield only accounts for less than 12% of the raw oil. [0003] At present, the production of light olefins mainly uses light hydrocarbons as raw mate...

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Problems solved by technology

[0012] Although increasing the catalytic conversion of FCC gasoline in the second reaction zone in the above method can increase the yield of propylene, some technologies sacrifice the propylene selectivity of FCC gasoline conversion, and some technologies rely on heavy oil catalytic cracking unit and generated FCC gasoline to regenerate Catalytic conversion is carried out in another independent device, and the catalysts and regeneration devices of the two devices are different to achieve the purpose of increasing propylene production, which makes the process complicated

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