A method and device for removing sulfur oxides and/or nitrogen oxides in flue gas

Abstract

A method and device for removing sulfur oxides and / or nitrogen oxides in catalytic cracking regenerated flue gas, comprising: in a catalytic cracking regenerator, under the condition of a temperature of 650°C to 750°C, a desulfurization and denitrification additive and a catalytic The cracking catalyst is in contact with the flue gas to remove sulfur oxides and nitrogen oxides. Part of the reacted mixture is introduced into the catalytic cracking reactor; the other part is introduced into the auxiliary agent regenerator, and is regenerated by reaction with reducing gas at a temperature of 450°C-650°C; the gas-solid flow in the auxiliary agent regenerator is separated from gas to solid , the separated gas phase is further processed, and the separated regenerated desulfurization and denitrification additives and catalytic cracking catalyst are returned to the catalytic cracking regenerator for recycling. In the method provided by the present invention, the auxiliary agent regenerator strengthens the regeneration depth of the desulfurization and denitrification auxiliary agent to be produced, thereby ensuring the flue gas treatment effect and prolonging the service life of the auxiliary agent; compared with the new flue gas treatment device, the process is simplified, which is conducive to improving the heat energy and pressure utilization, saving equipment investment.

Description

technical field [0001] The invention relates to a method for removing pollutants in industrial flue gas, more particularly to a method for removing sulfur oxides in industrial flue gas at high temperature, and belongs to the technical field of comprehensive flue gas treatment. Background technique [0002] The methods for controlling the sulfur emission of flue gas regenerated by fluidized catalytic cracking mainly include high-quality crude oil selection, raw material pretreatment, flue gas treatment and sulfur oxides (SO for short). x ) transfer technology. [0003] Based on source and cost considerations, refineries have little choice for crude oil; pre-hydrogenation of raw materials and flue gas treatment need to increase the cost of device construction, high energy consumption, high operating costs, but strong applicability, good investment economy, suitable for processing High-sulfur crude oil; SO in FCC flue gas can be controlled to a certain extent without adding ne...

AI Technical Summary

Problems solved by technology

[0005] Due to the mixed use, the sulfur transfer agent goes through the same path as the catalytic cracking catalyst, which is tested in the cycle between oxidizing atmosphere and reducing atmosphere: the sulfate formed on the sulfur transfer agent in the regenerator with high temperature and oxidizing atmosphere needs to have Good stability; when the mixture enters the reducing atmosphere, the reaction involving sulfate is only one of the many reactions involving multi-carbon number hydrocarbon cracking, isomerization, condensation, polycondensation, etc., involving sulfate and The reduction reaction of metal sulfide is not complete, and the result of long-term accumulation will lead to the failure of the sulfur transfer agent and the dosage of the transfer aid

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