System and method for deeply removing sulfur oxides in coal-fired flue gas

Abstract

The invention relates to a system and method for deeply removing sulfur oxides in coal-fired flue gas. The system comprises a wet-process single-tower high-efficiency desulfurization system, an absorbent injection system and a wet electrostatic flue gas purification system, wherein the wet-process single-tower high-efficiency desulfurization system is communicated with the absorbent injection system; the absorbent injection system is communicated with the wet electrostatic flue gas purification system; the wet electrostatic flue gas purification system is communicated with a chimney. Comprehensive purification of SOx in the coal-fired flue gas can be realized, ultra-low SOx emission is realized, the gas standard is achieved, deep purification of SO2 and SO3 can be further realized, and the SOx emission concentration is lower than 20mg / Nm<3>.

Description

technical field [0001] The invention belongs to the technical field of coal-burning flue gas pollutant control, and in particular relates to a system and method for deeply removing sulfur oxides from coal-burning flue gas. Background technique [0002] The coal consumption of my country's coal-fired power plant boilers accounts for about half of the country's coal consumption, and it is a major emitter of coal-fired air pollutants. Since the "Tenth Five-Year Plan", a large number of desulfurization devices in coal-fired power stations have been launched. By the end of 2012, the total capacity of thermal power desulfurization units in operation has reached 680 million kilowatts, accounting for 90% of all thermal power units. With my SO 2 With the continuous increase of emission reduction efforts, various desulfurization technologies have been popularized and applied in coal-fired power plants (of which wet methods account for more than 85%). 2 emission reduction has made an...

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Problems solved by technology

[0006] (1) It is difficult to meet the requirements of changing coal types and changing SO 2 Concentration, SO under variable working conditions 2 It is difficult to meet the national requirements for SO in key areas 2 50mg / Nm 3 emission standards, even lower emission standards requirements;

[0007] (2) The gypsum slurry at the outlet of the desulfurization tower is seriously carried, causing pollution problems such as gypsum rain, and the SO at the outlet of the desulfurization tower 3 Fog droplets are difficult to remove, resulting in SO 3 The problem of excessive emission concentration;

[0008] (3) Desulfurization flue gas often contains sulfuric acid aerosol, which causes certain corrosion to equipment;

[0009] (4) PM 2.5 Ultrafine particles cannot be effectively removed, PM 2.5 serious pollution

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