NOx and SO2 simultaneous absorption apparatus of coal-fired industrial boiler, and method thereof

Abstract

The invention relates to a NOx and SO2 simultaneous absorption apparatus of a coal-fired industrial boiler, and a method thereof. The apparatus comprises a deduster, an air heater, an absorption tower, a GGH heat exchanger, an induced draught fan and a chimney which are arranged behind the boiler. The internal of the absorption tower is divided into a spray zone, a refluxing and collecting zone, an oxidation zone and a concentration and crystallization zone. The method comprises the processes of absorbent preparation, absorbent absorption, absorbent regeneration and byproduct recovery. The method concretely comprises the following steps: Co(NH3)<6><2+> formed by complexing NH3 generated by decomposing ammonium bicarbonate and Co<2+> is adopted as an absorbent to absorb SO2 and NOx in flue gas, NH4NO2, NH4NO3, NH4HSO3, (NH4)2SO3 and (NH4)2SO4 generated after absorption are crystallized through a drying technology and then are recovered, Co(NH3)<6><3+> generated after oxidation in the absorption process undergoes membrane separation, and then is electrolyzed and reduced to form Co<2+> for reuse. The SO2 and NOx in the flue gas can be simultaneously absorbed by using only one apparatus, and the desulphurization and denitration efficiency is high; and ammonium nitrate and ammonium sulfate generated after the desulphurization and denitration can be used as raw materials for producing fertilizers, so discharge of pollutants is reduced, and resources are recovered.

Description

technical field [0001] The invention relates to a method for removing NOx and SO in flue gas 2 The device and method, especially relate to a kind of NH 3 As a removal agent and cobalt salt as a catalyst to remove NOx and SO from coal-fired industrial boiler flue gas 2 And recover (NH 4 ) 2 SO 4 and NH 4 NO 3 The apparatus and method are especially suitable for the SO 2 and NO x The field of industrial boilers with high removal efficiency and requiring recovery of resources. Background technique [0002] my country is a country where coal is the main energy source, and coal accounts for more than 70% of my country's primary energy consumption. Due to the shortage of oil and natural gas reserves in our country, this status quo cannot be fundamentally changed in the next 10 to 20 years. Burning coal produces SO 2 and pollutants such as NOx, SO 2 NOx and NOx are one of the main causes of acid rain and smog. Acid rain damages the ecological environment, destroys fores...

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Problems solved by technology

[0013] Aiming at the deficiencies and defects in the prior art, such as difficult recovery of by-product resources in the complex simultaneous desulfurization and denitrification system, low regeneration rate of the complex absorbent, complex absorption and regeneration, etc., the present invention proposes a NH 3 As a removal agent and cobalt salt as a catalyst to remove NOx and SO from coal-fired industrial boiler flue gas 2 , while recovering (NH 4 ) 2 SO 4 and NH 4 NO 3 The device and method can be used as a solution for industrial boiler desulfurization and denitrification

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