Method for desulfurizing and recovering NOx with alkali liquor

Abstract

The invention relates to a method for recovering NOx through desulfurization and denitrification, belongs to the field of processing of tail gas of a boiler, and particularly provides a method for absorbing SO2 and NOx in flue gas in an absorption tower through an alkaline absorbent, and analyzing and recovering NOx; SO2 is reacted to prepare sulfite or further prepare sulphate, so that the purpose of desulfurization is realized. The alkaline absorbent comprises sodium hydroxide, potassium hydroxide, sodium carbonate, potassium carbonate, sodium bicarbonate, potassium bicarbonate and compounding components thereof. The method disclosed by the invention has the benefits that (1) one device is used for dust removal, desulfurization and denitrification simultaneously, is small in occupied area, low in investment and low in operating cost; (2) the problem of recovering and utilizing NOx is solved, and the denitrification process is changed into a process for producing products with a high additional value, such as nitric acid; (3) a wet method is used for desulphurization and denitrification, the method has wide adaptability and is especially suitable for dust removal, desulfurization and denitrification of flue gas in a large number of small and medium boilers in China; (4) the main recovery product of sulfur is the sulfite, so that a space is provided for further utilization of by-products.

Description

[0001] The invention belongs to the field of boiler tail gas treatment. The invention relates to a desulfurization and denitrification method for recovering NOx, more specifically, absorbing SO in the flue gas with an alkali absorbent in an absorption tower 2 and NOx, then NOx is recovered by parsing, SO 2 The purpose of desulfurization is achieved by reacting to prepare sulfite or further prepare sulfate. Background technique [0002] The current flue gas desulfurization and denitrification mainly adopts "wet-FGD" and NH 3 Selective catalytic reduction (SCR) technology denitrification". [0003] At present, there are more than 100 methods of flue gas desulfurization in the world, and there are about 20 methods used in industry. Among them, the application of wet desulfurization technology accounts for about 85% of the entire industrial desulfurization equipment, and the wet limestone / lime method accounts for about 80% of the wet method, which occupies a dominant position i...

AI Technical Summary

Problems solved by technology

[0006] Aiming at the shortcomings of Wet-FGD+SCR combined desulfurization and denitrification, which require large investment, high operating costs, high consumption of ammonia, and low value of by-products, the present invention proposes a method for lye desulfurization and recovery of NOx, which achieves dust removal, Simultaneous desulfurization and denitrification and recovery of NOx, the system has less investment, stable and reliable operation, less resource and energy consumption, and high value of by-products

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