Method for removing sulfur oxide and nitrogen oxide in catalytic cracking regenerated smoke

Abstract

A method for removing sulfur oxide and nitrogen oxide in catalytic cracking regenerated smoke comprises the steps of injecting a reduction gas flow in the middle-upper part of a catalytic cracking regenerator, enabling regenerated smoke at the upper part of the regenerator to be contacted with the reduction gas and catalyst particles, conducting redox reaction on sulfur oxide, nitrogen oxide as well as oxygen in the smoke and hydrogen sulfide, hydrogen as well as small-molecular hydrocarbon in the reduction gas flow to generate gas elemental sulfur, nitrogen and steam; and enabling the mixed smoke containing gas sulfur after the reaction to enter a energy recycling system, arranging a liquid sulfur and solid sulfur collector at the low-temperature position to recycle the elemental sulfur, and discharging the catalytic cracking regenerated smoke reaching the standard. According to the method provided by the invention, the subsequent desulfuration treatment process of the smoke containing sulfur in a catalytic cracking device can be saved, so that the pollutant treatment process of the catalytic cracking device can be simplified, and the strong guaranteeing can be provided for the cleaning production of the catalytic cracking device.

Description

technical field [0001] The present invention relates to a method for waste gas treatment, more specifically, relates to a method for removing sulfur oxides and / or nitrogen oxides from regenerated flue gas discharged from a regenerator in a catalytic cracking unit, and recovering elemental sulfur. Background technique [0002] The catalytic cracking catalyst is circulated between the reactor and the regenerator. Usually, when leaving the reactor, the catalyst contains about 3-10wt% coke, and the deposited coke must be burned with oxygen in the air in the regenerator to restore catalytic activity. . The coke deposited on the catalyst is mainly a reaction condensate, and its main components are carbon and hydrogen. When the cracking raw material contains sulfur and nitrogen, the coke also contains sulfur and nitrogen. The carbon-deposited catalyst is regenerated with oxygen to generate CO 2 , CO and H 2 O, regeneration flue gas also contains SOx (SO 2 , SO 3 ) and NOx (NO,...

Images