A fcc device regenerative flue gas denitrification process

Abstract

The invention discloses a regeneration flue gas denitration process for an FCC apparatus. An FCC regenerator, a deduster, a flue gas turbine, a CO exhaust-heat boiler, an SCR denitration reactor, an air preheater, a desulphurization dedusting unit and a chimney are arranged along the flow direction of the flue gas. Regeneration flue gas is dedusted by the deduster, and before entering the CO exhaust-heat boiler, a flow of flue gas with a flow of 0.1 v%-5.0 v% of the original flow is led out and used as a diluent gas for ammonia gas; and the diluent gas and ammonia gas are mixed and sent into the reactor through an ammonia spray grating arranged in the SCR denitration reactor. The rest of the flue gas has energy recovered by the flue gas turbine, is sent into the CO exhaust-heat boiler, the SCR denitration reactor, the air preheater and the desulphurization dedusting unit in order, and is finally discharged by the chimney. The process provided by the invention plays the role of diluting and carrying the ammonia gas, improves the mixing effect of ammonia gas and flue gas, and saves energy consumption and equipment required by dilution of ammonia gas.

Description

technical field [0001] The invention relates to a treatment method for catalytic cracking (FCC) regenerated flue gas, in particular to a selective catalytic reduction (SCR) denitrification process for the treatment of regenerated flue gas of an FCC device in an oil refinery. Background technique [0002] Nitrogen oxides, collectively referred to as NOx, are one of the main sources of air pollution. The most harmful ones are: NO, NO 2 . The main hazards of NOx are as follows: (1) toxic to the human body; (2) toxic to plants; (3) can form acid rain and acid fog; (4) form photochemical smog with hydrocarbons; (5) destroy the ozone layer . [0003] In refineries, in the FCC (fluid catalytic cracking) process, the catalyst particles are repeatedly circulated between the catalytic cracking zone and the catalyst regeneration zone, during regeneration, the coke from the cracking reaction on the catalyst particles is removed by air oxidation at high temperature, Removal of the co...

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Problems solved by technology

The above methods all use air as the ammonia dilution gas, and the dilution gas requires a special dilution fan, which increases equipment and energy consumption; and the injection pressure and injection speed of the dilution gas are relatively low, which is not conducive to the mixing of ammonia and flue gas, affecting Denitrification rate

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