Method and device for achieving ultra-low emission of sulfur dioxides and nitrogen oxides from flue gas by two-stage ozone oxidation synergistic absorption

Abstract

The invention discloses a method and device for achieving ultra-low emission of sulfur dioxide and nitrogen oxide from flue gas by two-stage ozone oxidation synergistic absorption and belongs to the technical field of flue gas pollution control. The method comprises the following steps: enabling to-be-treated flue gas to sequentially pass through a first-stage oxidizer, a first-stage absorption tower, a second-stage oxidizer and a second-stage absorption tower to realize the efficient removal of the nitrogen oxide and obtain purified flue gas; performing defogging treatment on the purified flue gas at the top of the second-stage absorption tower and then emptying; recycling the absorption mother liquor of the second-stage absorption tower till an absorption effect is lost, conveying to a sub-salt oxidation reactor through a pump and then conveying to a subsequent by-product processing process by utilizing air oxidation. The method and the device disclosed by the invention have the benefits that the absorption efficiency of the nitrogen oxide is regulated and controlled through regulating and controlling the addition ratio of O3 subjected to first-stage oxidation and second-stage oxidation, so that the excessive addition of the O3 can be effectively avoided, and the energy consumption is reduced; through the method disclosed by the invention, the nitrogen oxide is reduced into N2, so that the efficient absorption and removal of the nitrogen oxide can be realized, and the secondary pollution is avoided.

Description

technical field [0001] The invention belongs to the technical field of flue gas pollution control, and relates to a method and a device for realizing ultra-low emissions of sulfur dioxide and nitrogen oxides in flue gas through two-stage ozone oxidation synergistic absorption. Background technique [0002] SO 2 and NO x As the main pollutant in the atmosphere, it not only directly endangers human health and ecosystem, but also is the precursor of smog, photochemical smog and acid rain. Over the past 20 years, my country has increased the flue gas SO 2 and NO x In terms of emission control, the thermal power industry has generally achieved ultra-low emissions, and non-electric industries such as steel and building materials are gradually implementing ultra-low emissions of flue gas pollutants. At present, the desulfurization and denitrification processes commonly used in industry are limestone / lime-gypsum desulfurization and selective catalytic reduction (SCR) denitrifica...

AI Technical Summary

Problems solved by technology

However, for non-electric industries such as cement, steel, and coking, it is difficult for SCR technology to achieve efficient and stable denitrification due to low flue gas temperature and large fluctuations.

On the other hand, the limestone / lime-gypsum flue gas desulfurization series SCR denitrification project involves many large-scale equipment, usually occupies a large area, and the cost and operating expenses are also high. It is very difficult to fully promote and apply it to non-electric industries. Therefore, There is an urgent need to develop new efficient multi-pollutant co-processing technologies

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