Method for eliminating oxynitride from air flow and the special equipment thereof

Abstract

The method of eliminating nitrogen oxide from gas flow is to lead the gas flow into an absorption tower, where the NO2 in the gas flow is absorbed directly by the absorbing liquid, the NO is oxidized by the chlorine the electrically catalytic oxidizing reactor into NO2 absorbed by the absorbing liquid and nitrite ion in the absorbed product is further oxidized into chemically stable nitrate ion, so as to reach gas purification and avoid secondary pollution. The gaseous oxidant and liquid oxidant are regenerated through an electrolysis process, and the absorbed liquid is returned with the circulating pump to the absorbing tower for reuse. The method has high absorption efficiency, no need of throwing oxidant and greatly lowered running cost. The present invention also discloses corresponding apparatus.

Description

technical field [0001] The invention relates to the technical field of a method for removing nitrogen oxides in an air stream and related devices. Background technique [0002] Nitrogen oxides (NOx) produced by human activities x ) mainly includes NO and NO 2 , Among them, more than 90% are produced by fuel combustion, followed by nitric acid production, chemical and pharmaceutical nitration reactions, metal surface and semiconductor treatment, etc. NOx is toxic to humans. NO has a strong affinity with hemoglobin in the blood, which reduces the oxygen transport capacity of the blood. NO also causes damage to the central nervous system, causing pathological changes and paralysis. NO 2 It is a brown gas with a specific irritating odor, NO 2 Severely stimulate the respiratory system, nitrate the hemoglobin in the blood, and affect the heart, liver, and kidney hematopoietic tissues of the human body. A large amount of nitrogen oxide emissions is also one of the main causes ...

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Problems solved by technology

[0003] Generally, there are two main methods for treating NOx exhaust gas: dry method and wet method. Among them, selective catalytic reduction (SCR), which is a dry method, is one of the main methods for treating fuel exhaust gas at present, but the catalyst has higher requirements on operating conditions. , Reducing agent ammonia is needed, sulfide and dust in the gas flow have a great impact on the life of the catalyst, the operating cost is high, and it is not suitable for the application of low-temperature emission sources. At present, non-equilibrium plasma technology (such as ZL 01121509.7) has been developed; The wet method uses various liquids to absorb NOx, and is the main method for treating low-temperature emission sources. There are two main methods: oxidation absorption method and reduction absorption method. Among them, the oxidation method uses hydrogen peroxide, sodium hypochlorite and potassium permanganate, etc. Absorption treatment is carried out as an oxidation absorbent; the reduction method uses sodium persulfite, sodium sulfide and urea as a reduction absorbent for absorption treatment

However, for nitrogen oxides containing more nitric oxide, because the Henry coefficient of nitric oxide in the solution is very small, the absorption efficiency is low, and the medicament is expensive, and the operating cost is high.

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