Double-riser catalytic cracking method and device

Abstract

The invention discloses a double-riser catalytic cracking method and device in petroleum chemical industry. The catalytic cracking method is as follows: respectively performing heavy oil catalytic cracking reaction and light hydrocarbon catalytic modification reaction by use of double risers, wherein the heavy oil catalytic cracking oil agent contact time is 0.2-1.5e; respectively performing gas-solid separation on two reaction material flows by use of respective special cyclone separators; respectively entering two reaction oil and gas flows into respective special fractionating towers for fractional distillation; after steam stripping of a spent catalyst, entering the spent catalyst into a baffle tubular regenerator, after mixing with a uncooled cycle regenerated catalyst, burning off more than 90% of generated coke by main air co-current contact with the baffle tubular regenerator, entering a semi regenerated catalyst into a turbulent bed regenerator, burning off the rest generated coke by main air countercurrent contact with the turbulent bed regenerator, and returning the regenerated catalyst into the risers for recycling use. The invention discloses a double-riser catalytic cracking device for realizing the catalytic cracking method. The double-riser catalytic cracking method and device can be used for heavy oil catalytic cracking and light hydrocarbon catalytic modification.

Description

technical field [0001] The invention relates to a double riser catalytic cracking method and device in the petrochemical industry. Background technique [0002] At present, the conventional catalytic cracking units used in the petrochemical industry generally have the following disadvantages: First, due to the limitation of regeneration kinetics, the regeneration temperature is relatively high, resulting in a relatively high temperature of the regenerated catalyst participating in the reaction (generally around 700°C) ;Limited by the heat balance of the device, the agent-oil ratio of the heavy oil riser is relatively small, generally the total agent-oil ratio is 5-8 (the total agent-oil ratio of the riser is the weight circulation of the catalyst in the riser and the feed of each strand of the riser The ratio of the sum of the weight flow rates), so that the number of active sites contacted by the unit weight of heavy oil feed is less, which inhibits the catalytic cracking r...

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Problems solved by technology

[0007] The purpose of this invention is to provide a kind of double-riser catalytic cracking method and device, to solve the existing catalytic cracking technology to reduce the regenerated catalyst temperature and improve the measures of heavy oil riser agent-oil ratio narrow scope of application (only applicable to Catalytic cracking unit with excess heat), the adjustment is not flexible enough (using the main air to cool the regenerated catalyst due to the limitation of the cooling main air volume, the cooling effect is affected, or the regenerated catalyst is cooled by the light hydrocarbon standby catalyst or external heat extractor The method of directly participating in the heavy oil catalytic cracking reaction to improve the heavy oil riser agent-oil ratio is limited due to the limited flow rate of the two catalysts), and the activity of the catalyst participating in the heavy oil catalytic cracking reaction is low (influenced by The impact of the mixed light hydrocarbon catalyst) and the difficulty of achieving a short oil agent contact time in the heavy oil riser

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