Simultaneously desulfurization and denitration wet ammonia flue gas cleaning technology and system thereof

Abstract

A wet ammonium flue gas cleaning process for desulfurizing and denitrifying and a system thereof are disclosed. The process oxidates NO in the flue gas to be NO2, makes SO2 and NO2 in the flue gas react with ammonium to product ammonium sulfite, ammonium nitrate and ammonium nitrite, then oxidates ammonium sulfite and ammonium nitrite therein to product the byproduct that is ammiaonia sulfate and ammonium nitrate, and lastly gets the clear flue gas after demisting to the desulfurizing and denitrifying flue gas. The system comprises a dust pre-collector, a hydrogen peroxide or ozone sprayer, and a desulfurizing and denitrifying tower, which are connected in turns, wherein ammonia replenishment system and an air feeding device are mounted at the bottom of the desulfurizing and denitrifying tower, sprinkling layer which can cycle sprinkle is mounted at the middle, and a demister is mounted at the upper. The invention has a simple process, a simplified system, a low investment and operation cost. The invention not only has a high efficiency in desulfurizing and denitrifying, but also a high utilance of desulfurizing and denitrifying absorbent, and byproduct of desulfurization and denitration can be utilized as chemical fertilizer of ammiaonia sulfate and ammonium nitrate.

Description

technical field [0001] The invention relates to a purification treatment technology for flue gas discharged from a coal-fired power station, in particular to a wet-type ammonia flue gas cleaning process and system for simultaneous desulfurization and denitrification. Background technique [0002] my country is one of the few countries in the world that use coal as the main energy source. Coal accounts for more than 70% of my country's primary energy production and consumption. Coal-burning waste gas such as sulfur dioxide SO 2 , Nitrogen oxide NO x emissions have formed a huge environmental pollution, fundamentally control SO 2 and NO x The pollution caused by discharge is imperative. [0003] At present, most of the processes and equipment for flue gas desulfurization, flue gas denitrification, and flue gas dust removal used in coal-fired power plants are still developed independently, forming their own technical systems and process flows. In order t...

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Problems solved by technology

[0006] In order to solve the above problems, the Chinese utility model patent specifications with the announcement numbers CN2712446Y and CN2746971Y proposed a "Flue Gas Desulfurization and Denitrification Device" and "Desulfurization and Denitrification Integrated Flue Gas Purification Tower", but the desulfurization and denitrification equipment are all bulky. Large packing device, and directly use ammonia solution to absorb nitrogen oxide NO in flue gas x , not only greatly increases the resistance of the entire desulfurization and denitrification equipment, but also cannot effectively remove NO in the flue gas x

This is because NO x More than 90% of the components are nitric oxide NO, and NO is difficult to dissolve in water, and it is difficult to absorb NO by simple washing method

[0007] It can be seen that the use of more than two sets of independent desulfurization and denitrification systems is not only complicated in flue gas purification equipment, large in floor area, and high in construction and operation costs, but also the rational combination of these independent desulfurization, denitrification and dust removal systems to achieve comprehensive and efficient operation there are still many difficulties

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