Method for simultaneously removing SO2 and NO in flue gas by biological reduction and complexing absorption

Abstract

The present invention belongs to the smoke purification technical field, and discloses a method for deoxidizing integrating, complexing and absorbing the organism and removing SO2 and No in the smoke, which is characterized in that alkaline absorption solution containing the ferrous-iron complexing agent Fe<II>(L) is arranged inside an absorption tower; SO2 is neutralized in the absorption solution, and NO is absorbed by the complexing iron; the smoke is exhausted from the top of the absorption tower; the absorption tail solution enters into an anaerobic reactor, and SO3<2> or SO4<2> in the tail solution is deoxidized to sulfide by sulfate reducting bacteria; the sulfide deoxidizes Fe<II>(L)-NO, Fe<III>(L) and other N-S compound in the tail solution to Fe<II>(L) and N2; at the same time, the sulfide is oxidized to simple sulfur; the absorption tail solution containing the Fe<II>(L) is directly returned to the smoke absorption tower to be used as desulphurization denitration absorption solution. The method of the present invention has the advantages that the micro-organism smoke desulphurization method and the complexing absorption smoke denitration method are combined, so that the sulfur dioxide and the nitrogen oxide can be synchronically removed, and the sulfur resource can be recycled; the complexing iron absorption agent can be cycled for use.

Description

technical field [0001] The invention belongs to the technical field of flue gas purification, and relates to a method for simultaneously removing SO in flue gas through biological reduction combined with complexation absorption 2 and NO method. Background technique [0002] With the intensification of environmental pollution, how to economically and effectively control SO in coal combustion 2 The emission of NO and NO is the focus of energy and environment field all over the world. At present, there is no relatively mature and stable treatment process for simultaneous desulfurization and denitrification of flue gas. Most of them adopt separate treatment processes, which not only occupy a large area, complex equipment, are prone to corrosion and scaling, but also have high investment and operating costs. Therefore, the wet simultaneous desulfurization and denitrification technology with simple development technology, low operating cost, usable by-products and good operating...

AI Technical Summary

Problems solved by technology

However, this method has major disadvantages: one is that the product Fe after absorption II The regeneration of (EDTA)-NO is difficult, and the second is the oxygen in the flue gas and its easy conversion of Fe II (EDTA) is oxidized to Fe III (EDTA), while Fe III (EDTA) does not absorb NO

However, for Fe II (EDTA) complexation denitrification, the real recycling of the absorption liquid has not been realized, and the economical and effective regeneration method of the absorption liquid has not been found, which is an important reason hindering the application of this technology.

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