Catalytic cracking method and device

Abstract

The invention discloses a catalytic cracking method and device used in the petrochemical industry. The catalytic cracking method comprises the following steps: carrying out catalytic cracking reaction on a heavy oil by using a riser by enabling the oil to contact with a catalyst for 0.2-1.5 seconds; carrying out gas-solid separation on a product of reaction by using a cyclone separator; fractionating oil gases of reaction by using a fractionating tower; carrying out stripping on the catalyst to be regenerated by steam, and then enabling the catalyst to be regenerated to enter a first turbulent-bed regenerator to be in down-stream contact with main air in a first turbulent-bed regenerator so that 40-50% of the generated coke is burnt off; carrying out stripping on a first half of the semi-regenerated catalyst by smoke generated by the first turbulent-bed regenerator, and then enabling the first half of the semi-regenerated catalyst to enter a tubular regenerator to be in down-stream contact with smoke generated by the first turbulent-bed regenerator so that 40-50% of the generated coke is burnt off; enabling the second half of the semi-regenerated catalyst to enter the second turbulent-bed regenerator to be in down-stream contact with main air in the second turbulent-bed regenerator so that the remaining generated coke is burnt off; and returning the regenerated catalyst to the raiser so as to be recycled. The invention further discloses a catalytic cracking device implementing the catalytic cracking method. The catalytic cracking method and device can be used for the catalytic cracking of heavy oil.

Description

technical field [0001] The invention relates to a 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 reaction to a ...

AI Technical Summary

Problems solved by technology

[0006] The purpose of this invention is to provide a kind of catalytic cracking method and device, to solve the existing catalytic cracking process, the measures for reducing the regenerated catalyst temperature have a narrow scope of application (not applicable to single riser catalytic cracking device or only applicable to those with catalytic cracking unit with excess heat), inflexible adjustment (using the main air to cool the regenerated catalyst due to the limitation of the cooling main air volume, which affects the cooling effect), and the activity of the catalyst participating in the reaction is low (affected by the mixing of the light hydrocarbon catalyst) And it is difficult to achieve shorter oil contact time and other problems

Images