Method for simultaneously desulfurizing, denitrating and purifying flue gas

Abstract

The invention discloses a method for simultaneously desulfurizing, denitrating and purifying flue gas and belongs to the field of flue gas purification. The method comprises the following steps: spraying the flue gas at the temperature of 50-90 DEG C by using ammonia absorption liquid to obtain a solution, and aerating and oxidizing the solution to obtain an ammonium sulfate solution; exchanging heat between the obtained flue gas and the original flue gas, heating to 120-350 DEG C, and supplementing ammonium hydroxide; converting NO and NO2 in the flue gas into N2 by addition or non-addition of an activated carbon material of a catalyst; performing reaction on the remaining SO2, ammonia and water vapor to generate ammonium sulfate; adsorbing mercury, dioxin, furan, a volatile organic compound, ammonia sol and other trace toxic substances by activated carbon; and regenerating the activated carbon after absorption and adsorption by using washing and heating methods. The method has the advantages that the process is simple and convenient, and the desulfurizing and denitrating efficiency is high; various toxic substances and fine particles in the flue gas can be adsorbed, a good prevention effect on PM2.5 pollution of industrial flue gas is achieved, ammonium sulfate and ammonium nitrate fertilizer byproducts are obtained, and resources can be recycled. The method can be applied to purification of sulfur-containing and nitrate-containing flue gas in the fields of boilers, metallurgy, chemical industry, thermoelectricity and garbage incineration power generation.

Description

Technical field: [0001] The invention belongs to the technical field of flue gas purification, and in particular relates to a method for simultaneously desulfurizing and denitrating flue gas. Background technique: [0002] With the increasing environmental pollution, the country has included air pollution control as a key prevention and control target, especially the indicators of sulfur and nitrogen oxides are the top priority in air pollution control. If two sets of devices are used to desulfurize and denitrify separately, not only the area will be large, but also the investment, management and operation costs will be high. In recent years, all countries in the world, especially industrially developed countries, have successively carried out research and development of simultaneous desulfurization and denitrification technologies. Simultaneous flue gas desulfurization and denitrification purification treatment technology has become a research and development hotspot in th...

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Problems solved by technology

However, the above methods have the disadvantages of complex process technology, harsh reaction conditions, poor desulfurization and denitrification effects, and high operating costs.

In particular, the selective catalyst reduction denitrification technology (SCR) or non-catalytic reduction denitrification technology (SNCR) is widely used in my country at present for denitrification, and then the limestone-gypsum method is used for desulfurization process. This method has high investment costs and high operating costs. At the same time, a large amount of by-product desulfurization gypsum is produced, and the post-processing is more difficult

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