Low-temperature flue gas desulfurization and denitrification coupling absorption process capable of reducing oxidant escape

Abstract

The invention discloses a low-temperature flue gas desulfurization and denitrification coupling absorption process capable of reducing oxidant escape. The process comprises the following steps: oxidizing a nitrogen oxide containing low-valence nitrogen in flue gas into a nitrogen oxide containing high-valence nitrogen by adopting the oxidant; then conveying the flue gas containing the nitrogen oxide containing high-valence nitrogen into a desulfurization and denitrification coupling absorption tower (3), absorbing the nitrogen oxide containing high-valence nitrogen in the flue gas into a nitrate in the desulfurization and denitrification coupling absorption tower (3) through an alkaline solution absorbent, and absorbing SO2 in the flue gas into a sulfite and a bisulfite; and meanwhile, reducing the residual oxidant in the flue gas by using the sulfite and a hydrosulfite formed by absorption in the desulfurization and denitrification coupling absorption tower (3). The process disclosedby the invention comprises three technological processes of desulfurization, denitration and oxidant removal, so that the purposes of desulfurization and denitration can be achieved, meanwhile, the discharge amount of the oxidant is remarkably reduced, the flue gas treatment process is shortened, and the problem of oxidant escape of an oxidation method low-temperature denitration process is solved.

Description

technical field

[0001] The invention relates to the technical field of low-temperature desulfurization and denitrification of industrial tail gas, in particular to the technical field capable of reducing oxidant escape, and specifically relates to a low-temperature flue gas desulfurization and denitrification coupled absorption process for reducing oxidant escape. Background technique

[0002] At present, the process requirements for desulfurization and denitrification of industrial tail gas in various industries are common. The desulfurization and denitration of flue gas are two different processes, so different equipment is generally used for removal. For low-temperature flue gas desulfurization, the wet desulfurization process is generally used in the desulfurization tower. Flue gas denitrification is more commonly used by SNCR and SCR processes, but for low temperature (below 100°C) flue gas, oxidation denitrification process is generally used. For low-temperature flue...

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