Method for reducing and removing nitrogen oxide by adsorption-oxidation and liquid phase absorption

Abstract

The invention discloses a method for reducing and removing nitrogen oxide by adsorption-oxidation and liquid phase absorption. The method comprises the following steps: (1) letting exhaust gas containing nitrogen oxide to pass through a fixed bed reactor filled with a molecular sieve to oxidize part of the nitrogen oxide and adsorb the nitrogen oxide on the molecular sieve; (2) stopping feeding the exhaust gas, feeding carrier gas (air or nitrogen), and performing heating desorption on a bed layer of the molecular sieve in a WF-01 differential integral reactor; (3) absorbing desorbed gas with a sodium sulfite in a filler tower, to finally reduce the gas into nitrogen. According to the method disclosed by the invention, efficient and low-cost removal of the nitrogen oxide is realized; desorbed nitrogen dioxide is 80 percent or higher of the total volume of the desorbed nitrogen oxide; after the gas is absorbed and reduced with the sodium sulfite solution, the denitrification rate can be up to 80 percent or higher.

Description

technical field [0001] The invention relates to the treatment of nitrogen oxides in flue gas in various production processes, in particular to a method for removing nitrogen oxides in flue gas by combining adsorption oxidation with liquid phase absorption and reduction, and reducing them to nitrogen. Background technique [0002] Nitrogen oxides are one of the main sources of air pollution. Their emissions can not only cause acid rain and photochemical smog, but also destroy the ozone layer, causing serious harm to the natural environment and human production and life. Therefore, the flue gas must be denitrified before being discharged. deal with. [0003] At present, there are two kinds of mature flue gas denitrification technologies: selective catalytic reduction and non-selective catalytic reduction. The non-selective catalytic reduction denitrification effect is poor, and the denitrification rate is generally about 40%. At present, the most widely used and most promisin...

AI Technical Summary

Problems solved by technology

However, this method has the following problems: the engineering cost is extremely expensive, the operating cost is also very high, and the floor area is large; the amount of ammonia in the reaction process needs to be precisely controlled, and ammonia gas leakage is prone to occur; the reaction temperature is high and the temperature window is narrow; the flue gas contains sulfur dioxide seriously affect the service life of the catalyst

But generally speaking, the methods currently developed are not satisfactory, such as limited scope of application, high requirements for reaction conditions, cumbersome equipment, high energy and material consumption, and low conversion rate of nitrogen oxides.