Device and method for synchronous desulfurization and denitrification of flue gas

Abstract

The invention discloses a device and method for synchronous desulfurization and denitrification of flue gas. The method comprises the following steps: a porous filler is put in a box-shaped plate frame to be used as a gas-permeable absorption and reaction medium, a washing absorption liquid containing polyethylene glycol and manganese oxide is added into a flue gas pipeline by using a spraying mode, the washing absorption liquid forms a liquid film on the surface of the filler, and the manganese oxide in the washing absorption liquid converts NO and SO2 in the flue gas into a nitrate and a sulfate, respectively. After the flue gas is treated by the device and method for synchronous desulfurization and denitration provided by the invention, the SO2 removal rate is maintained at 95% or more,the NO removal rate is maintained at 80% or more, and the reaction product can be separated and utilized; and the equipment is simple, the operation costs are low, and the device and the method havevery good prospects.

Description

technical field [0001] The invention belongs to the field of air pollution control engineering, and in particular relates to a flue gas treatment method for synchronous desulfurization and denitrification by a wet absorption method. Background technique [0002] Various types of boilers and kilns produce a large amount of SO in the process of high temperature combustion 2 , NOx, resulting in acid rain in 81.6% of cities across the country. Nitrogen oxide emissions can also lead to regional environmental pollution problems such as photochemical smog and ozone layer depletion. Current technologies for controlling NOx emissions include Selective Catalytic Oxidation (SCO), Non-Selective Catalytic Reduction (SNCR) and Selective Catalytic Reduction (SCR). Desulfurization processes are mainly wet and semi-dry, among which calcium desulfurization is the main one, accounting for about 85% of the market. At present, the flue gas purification process widely used in my country is the...

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Problems solved by technology

Patent CN107744715A uses the main product ammonium sulfite in the ammonia desulfurization process as NO, SO 2 Absorbent, use bubbling method and add absorption aid CuO in the absorption liquid to solve the problem of NO insoluble in water, but there are secondary pollution problems such as ammonia volatilization

Patent CN101574617B uses the pulp prepared from pyrolusite and metal chelating agent as absorbent to absorb SO in coal-fired flue gas 2 , NO x Synchronous absorption and removal, the metal chelating agent is used to remove calcium, magnesium, lead, zinc, iron and other multivalent metal ions in pyrolusite pulp, eliminating the problem that metal ion precipitation and scaling affect the desulfurization interface reaction. After solid-liquid separation, the mother liquor can be Utilize the poor solubility of manganese sulfate and manganese nitrate at the same temperature to realize the recycling of sulfur and manganese, but it does not improve the solubility of NO in the absorption liquid, and there is a problem of low NO removal rate

[0004] In the above studies, when strong oxidants such as sodium chlorite and ozone were used, although NO, SO 2 The removal efficiency is high, but most of the oxidants are relatively expensive, and the investment and operation costs are high, so it is difficult to apply industrially; if the absorption liquid such as ammonium sulfite and pyrolusite slurry is used, the NO removal rate is low, generally 60- 70%, difficult to meet industrial emission standards

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