Catalytic cracking method and device employing double lift pipes

Abstract

The invention discloses a catalytic cracking method and device employing double lift pipes in the petrochemical industry. The method comprises the following steps: carrying out heavy oil fluid catalytic cracking and light dydrocarbon catalytic reforming by adopting two lift pipes respectively, wherein the heavy oil catalytic cracking oil agent contact time is 0.2-1.5 seconds; carrying out gas-solid separation on two material flows by virtue of special cyclone separators; feeding a spent catalyst into a first turbulent bed regenerator after steam stripping, and contacting main air of the first turbulent bed regenerator in a down-flow manner, so as to burn off 40%-50% of generated coke; lifting a first section of semi-regenerated catalyst by smoke which is generated by the first turbulent bed regenerator to enter a tubular regenerator, and contacting the smoke which is generated by the first turbulent bed regenerator in a down-flow manner, so as to burn off 40%-50% of generated coke; feeding a second section of semi-regenerated catalyst into a second turbulent bed regenerator, and contacting main air of the second turbulent bed regenerator in a countercurrent manner, so as to burn off the residual generated coke; and returning the regenerated catalyst to the two lift pipes to recycle. The invention discloses a catalytic cracking device employing double lift pipes for achieving the method.

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 shortcomings: 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 ratio of agent to oil in the heavy oil riser is relatively small, generally the total agent to oil ratio is 5 to 8 (the total agent to 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 total weight flow rate), so that the unit weight of the heavy oil feed contacts with fewer active centers, which inhibits the catalytic cracking...

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Problems solved by technology

[0006] The purpose of the present invention is to provide a kind of double riser catalytic cracking method and device, to solve the existing catalytic cracking process, the measures for reducing the temperature of the regenerated catalyst are narrow in scope of application (only applicable to catalytic cracking units with excess heat) , the adjustment is not flexible enough (the cooling effect is affected by the main air cooling regenerated catalyst due to the limitation of the cooling main air volume), the activity of the catalyst entering the heavy oil riser to participate in the reaction is low (affected by the mixing of the light hydrocarbon standby catalyst) and the heavy oil lift Tubes are difficult to achieve shorter oil contact time and other issues

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