Denitration system and method for sintering flue gas without ammonia reducing agent

Abstract

The invention relates to a denitration system and method for sintering flue gas without using ammonia as a reducing agent. The system comprises a sintering machine, and a heater, a denitration reactor, a deduster, a blower fan, a desulfurization tower and a chimney sequentially connected with the sintering machine. The denitration reactor is arranged before the deduster; that is, the deduster is arranged between the heater and the denitration reactor. A catalyst layer is provided in the denitration reactor. The method comprises the following steps that: sintering flue gas is heated by the heater to an appropriate temperature before the deduster and is sent to the denitration reactor; NOx is removed by a catalytic reduction in the denitration reactor under the influence of a catalyst, wherein the chemical equation for the removing of NOx is 2NO +2CO =N2 + 2CO2; the reacted sintering flue gas is emitted into the atmosphere after dedusting and desulphurization. According to the invention, the ammonia reducing agent needs not to be added, the catalyst is widely available and cheap, and investment and operation cost needed is low; the reducing agent used in the invention is CO reduction ingredients in the sintering flue gas instead of ammonia, thereby avoiding many problems resulting from the utilization of an ammonia reducing agent.

Description

technical field [0001] The invention relates to emission reduction of nitrogen oxides (NOx) in sintering flue gas, belongs to the technology for reducing emission of nitrogen oxides in sintering flue gas in the field of iron and steel metallurgy, and is a sintering flue gas denitrification system and method without ammonia reducing agent. Background technique [0002] Sintering production is one of the most important process units of modern steel production, and a large amount of air pollutants are produced during the production process, such as particulate matter, NOx, SO 2 , CO, PCDD / F, various heavy metals, etc., are the largest polluters of iron and steel complexes, and also the largest NOx polluters of iron and steel complexes, because sintering NOx emissions usually account for 50% of the total emissions of the entire plant ~60%, excluding captive power plants. At present, the country has listed NOx in the total control index of the "Twelfth Five-Year Plan". Clear re...

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