Device and method for removing sulfur oxides in high-humidity flue gas

Abstract

The invention discloses a device and a method for removing sulfur oxides in high-humidity flue gas. The device comprises a condensate recovery tower and a desulfurization tower, the condensate recovery tower sequentially comprises a washing section and a condensing section from bottom to top; wherein the desulfurization tower sequentially comprises an oxidation section, a primary absorption section, a secondary absorption section and a demisting section from bottom to top; wherein a flue gas inlet is formed in a washing section of the condensate recovery tower, the washing section of the condensate recovery tower is connected with the demisting section of the desulfurization tower, and an outlet of the condensate recovery tower is connected with a primary absorption section of the desulfurization tower. The invention also provides the method for removing sulfur oxides in high-humidity flue gas. According to the device and the method disclosed by the invention, strong acid gas (SO3, HCl and the like), condensed water, weak acid gas (SO2) and other components in the high-humidity flue gas are removed step by step, and after the recycled condensed water is subjected to simple physicochemical treatment, the water quality can meet the requirements of municipal sewage recycling industrial water quality (GB / T 19923-2005).

Description

technical field [0001] The invention relates to a device and method for removing sulfur oxides in flue gas, in particular to a device and method for removing sulfur oxides in high-humidity flue gas. Background technique [0002] Sulfur pollution refers to the pollution caused by sulfur and its compounds in the environment. Sulfur is widely distributed in the earth's crust, and various fossil fuels (coal and petroleum, etc.) contain sulfur. Sulfur exists in a large amount in the environment as sulfur oxides, and some of it exists as hydrogen sulfide and organic sulfur (such as mercaptan, sulfide, dimethyl sulfide, etc.), and produces a strong irritating odor pollution. An important pollutant of sulfur in the atmosphere is sulfur dioxide. [0003] The sulfur oxide pollutants in flue gas are mainly sulfur dioxide and sulfur trioxide. The main body is sulfur dioxide, which mainly comes from fossil fuel combustion, sulfur-containing ore smelting, petroleum refining sulfur reco...

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Problems solved by technology

[0004] For the removal of sulfur oxides in flue gas, the current mainstream process is wet desulfurization process, but for the removal of sulfur oxides in high humidity flue gas produced by the incineration of high hydrogen and sulfur-containing fuels (such as petroleum refining sulfur recovery Incineration tail gas), since the water content (volume fraction) in the flue gas is generally above 25%, the corresponding flue gas water dew point temperature is 65°C, and the acid dew point temperature is about 150°C. The temperature of the flue gas is above 200°C. In order to control the temperature of the flue gas entering the desulfurization tower at the optimum temperature window of the desulfurization reaction to ensure the desulfurization efficiency, the general method is to circulate and spray a large amount of low-concentration absorption liquid or process water to cool down to the optimum temperature for the desulfurization reaction. Temperature window, during this process, a large amount of condensed water and strong acid gas enter the absorption liquid or circulating process water, resulting in the low concentration of this part of the desulfurization solution, which cannot reach the saturation concentration. It needs to be evaporated and crystallized by an external heat source, and then centrifugally dried to produce commercial sulfate. Solid, high energy consumption, and high ammonia nitrogen and high sulfate wastewater generated in the production process is difficult to treat

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