Smoke treatment device and method

Abstract

A flue gas treatment device and method. The device comprises a flue gas treatment device, a hydrogen peroxide supply device, a dedusting and demisting device, an evaporation and concentration device, a circulating sedimentation device, etc., wherein the flue gas treatment device comprises a hydrogen peroxide spray oxidation reaction layer (72), an absorption spraying area (4) and a slurry circulation area, the hydrogen peroxide spray oxidation reaction layer (72) being arranged in the absorption spraying area (4); the dedusting and demisting device is located above the absorption spraying area (4); and both of the evaporation and concentration device and the circulating sedimentation device are arranged in the flue gas treatment device. The method uses the device to treat flue gas.

Description

technical field [0001] The invention relates to a flue gas treatment device and method, in particular to a device and method for simultaneously removing sulfur dioxide, nitrogen oxides and dust in flue gas, and using the waste liquid to produce magnesium sulfate and magnesium nitrate by-products. Background technique [0002] In terms of desulfurization, denitrification, dust removal and fog removal, at present, the desulfurization and denitrification technologies commonly used in my country are wet flue gas desulfurization technology (WFGD) (among them, calcium method is the majority) combined with selective catalytic reduction denitrification technology (SCR) or selective non-catalytic denitrification technology. Reduction denitrification technology (SNCR). Recently, some experts proposed to combine the original wet desulfurization device to reuse H 2 o 2 The strong oxidizing property completes desulfurization and denitrification at the same time. The existing demisting ...

AI Technical Summary

Problems solved by technology

The disadvantage of this process is that steam is used as the medium for evaporation, crystallization and drying, which consumes a large amount of steam and increases the operating cost of desulfurization and denitrification

For example, CN1733656A discloses a method of utilizing boiler flue gas to produce magnesium sulfate heptahydrate fertilizer, wherein the magnesium sulfate solution is concentrated and crystallized by using the characteristic that the solubility of magnesium sulfate decreases when the temperature exceeds 60°C. This high temperature crystallization method requires It consumes more high-quality steam, and it will cause frequent blockage of the slurry delivery pipeline, making it difficult to achieve continuous and stable production of by-products

CN102745726A discloses a method for producing magnesium sulfate heptahydrate by using desulfurization waste liquid. The crystallization method adopted is "send the obtained liquid into an evaporator, discharge the slurry after concentration, and the evaporation temperature is 100-130°C. The slurry is cooled and crystallized at a temperature of 30-45°C to obtain magnesium sulfate heptahydrate. This method of evaporation and crystallization has higher requirements on steam quality. If low-grade steam is used, the consumption will increase

Although the overall cost of desulfurization by the magnesium method is lower than that by the calcium method, the production of magnesium sulfate by using three-effect evaporation and other processes has the problems of wasting steam resources and high desulfurization operating costs

Affected by dust and other impurities in the flue gas, the magnesium sulfate produced by the direct production of magnesium sulfate in the tower generally has a high impurity content, and it is difficult to separate later, which affects the quality and external appearance of magnesium sulfate

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