A system and method for wet desulfurization and denitrification

Abstract

The invention provides a system for wet desulfurization and denitrification. The system comprises a desulfurization and denitrification tower and a desulfurization tower which are connected through a pipeline, wherein a flue gas inlet, a flue gas outlet, an ammonia water inlet, a process water inlet, an ammonium sulfate absorption liquid inlet and an ammonium sulfite absorption liquid discharge opening are formed in the desulfurization and denitrification tower; a flue gas inlet, a process water inlet, an ammonium water inlet and an ammonium sulfate absorption liquid discharge opening are formed in the desulfurization tower; a chimney is arranged at the top of the desulfurization tower; an oxidation air blower is arranged outside the desulfurization tower; circulating pumps used for circulation of absorption liquid in the towers are arranged outside the desulfurization and denitrification tower and the desulfurization tower respectively. Compared with the traditional wet method, the method provided by the invention can simultaneously perform desulfurization and denitrification, the desulfurization rate is more than 95 percent, and the denitrification rate is more than 40 percent; ammonia escape and aerosol generation amount is less; the by-products can be in resource utilization; the temperature of the denitrification reaction is low, heating treatment is not needed to be performed on the flue gas, and the operation cost is low; compared with other methods for simultaneous desulfurization and denitrification, the method is low in investment and construction cost.

Description

technical field [0001] The invention belongs to the field of flue gas purification, and in particular relates to a system and method for removing sulfur oxides and nitrogen oxides in flue gas. Background technique [0002] At present, there are two main types of sintering flue gas desulfurization and denitrification technologies widely used at home and abroad, one is the combination of wet desulfurization technology and selective catalytic reduction (SCR) denitrification technology; the other is carbon-based material adsorption desulfurization and denitrification technology. [0003] The most commonly used method for wet flue gas desulfurization is the limestone / gypsum method, and the desulfurization efficiency can be as high as 90%. SCR denitrification technology can achieve a denitrification rate of 70% to 90%, but the temperature required by this technology is 250 to 450°C, and the temperature of sintering flue gas is generally 90 to 170°C, which cannot meet the temperatu...

AI Technical Summary

Problems solved by technology

[0014] In order to obtain high-quality ammonium sulfate in the traditional wet ammonia desulfurization system, air is usually blown into the desulfurization tower directly through the oxidation fan to oxidize the ammonium sulfite in the absorption liquid into ammonium sulfate. Due to the lack of sufficient denitrification agent in the absorption liquid — Ammonium sulfite, so there is basically no denitrification function

Images