Method for wet desulfurization flue gas dewhitening and desulfurization wastewater emission reduction

Abstract

A method for wet desulfurization flue gas dewhitening and desulfurization wastewater emission reduction, comprising the following steps: exchanging heat between the desulfurization wastewater discharged from the wet flue gas desulfurization absorption tower and the original flue gas, while reducing the temperature of the original flue gas, Realize the temperature rise of desulfurization wastewater; the heated desulfurization wastewater is directly contacted with the cooling air to cool down by air cooling, and part of the water in the desulfurization wastewater is vaporized and then enters the cooling air; the desulfurization wastewater after air cooling continues to exchange heat with the original flue gas Raise the temperature, then continue to directly contact with the cooling air to cool down, and repeat this cycle. This method simultaneously solves the problems of flue gas "de-whitening" and desulfurization wastewater discharge reduction, as well as the crystallization and recovery of soluble desulfurization products, and creates a better "de-whitening" effect at lower investment and operating costs. The discharge creates conditions, and at the same time realizes the oxidation, concentration, cooling crystallization and product recovery of soluble desulfurization products.

Description

technical field

[0001] The invention relates to wet flue gas desulfurization, in particular to a method for flue gas whitening, desulfurization waste water reduction and recovery of soluble desulfurization products. Background technique

[0002] Wet flue gas desulfurization has been adopted by more than 85% of flue gas desulfurization systems in the world due to its technical and economic advantages such as high desulfurization efficiency, low-cost and easy-to-obtain desulfurizers, and resource utilization of desulfurization products. However, limited by the technical defects of the "white plume" produced by wet desulfurization and the discharge of desulfurization wastewater, the trend of domestic flue gas desulfurization has evolved from wet desulfurization to (semi) dry desulfurization. However, (semi) dry desulfurization has inherent technical defects such as low mass transfer efficiency, large flue gas resistance, and difficult disposal of desulfurization products, resul...

Examples

Embodiment 1

[0032] A 360 square meter sintering machine lime-gypsum flue gas desulfurization system, its process parameters are as follows: flue gas volume 1200000Nm 3 / h, raw flue gas temperature 150°C, moisture content 8% (v / v), SO 2 Concentration 800mg / m 3 , C1 concentration 80mg / m 3 ; Net flue gas SO 2 Concentration 50mg / m 3 , C1 concentration 0mg / m 3 . The ambient temperature is 20°C.

[0033] Such as process flow figure 1 As shown, the raw flue gas from the sintering machine enters the desulfurization wastewater evaporation section 1 through the pipeline (101), and exchanges heat with the 1.92t / h desulfurization wastewater introduced from the pipeline (116). The water in the desulfurization wastewater is evaporated into the The original flue gas, the calcium chloride particle that forms enters dust collector 2 by pipeline (102) along with original flue gas, and flue gas temperature drops to 146.7 ℃ by 150 ℃, and the moisture content of former flue gas increases from 8% (v / v) ...

Embodiment 2

[0038] A 360 square meter sintering machine magnesium oxide wet flue gas desulfurization system, its process parameters are as follows: flue gas volume 1200000Nm 3 / h, raw flue gas temperature 150°C, moisture content 8% (v / v), SO 2 Concentration 800mg / m 3 , C1 concentration 80mg / m 3 ; Net flue gas SO 2 Concentration 50mg / m 3 , C1 concentration 0mg / m 3 . The ambient temperature is 20°C.

[0039] Such as process flow figure 2 As shown, the raw flue gas from the sintering machine enters the desulfurization wastewater evaporation section 1 through the pipeline (201), and exchanges heat with the 2.4t / h desulfurization wastewater introduced from the pipeline (219). The water in the desulfurization wastewater is evaporated into the The raw flue gas generates magnesium salt particles and enters the dust collector 2 from the pipeline (202) along with the raw flue gas, the temperature of the raw flue gas drops from 150°C to 145.9°C, and the moisture content of the raw flue gas i...

technical field

[0001] The invention relates to wet flue gas desulfurization, in particular to a method for flue gas whitening, desulfurization waste water reduction and recovery of soluble desulfurization products. Background technique

[0002] Wet flue gas desulfurization has been adopted by more than 85% of flue gas desulfurization systems in the world due to its technical and economic advantages such as high desulfurization efficiency, low-cost and easy-to-obtain desulfurizers, and resource utilization of desulfurization products. However, limited by the technical defects of the "white plume" produced by wet desulfurization and the discharge of desulfurization wastewater, the trend of domestic flue gas desulfurization has evolved from wet desulfurization to (semi) dry desulfurization. However, (semi) dry desulfurization has inherent technical defects such as low mass transfer efficiency, large flue gas resistance, and difficult disposal of desulfurization products, resul...

Examples

Embodiment 1

[0032] A 360 square meter sintering machine lime-gypsum flue gas desulfurization system, its process parameters are as follows: flue gas volume 1200000Nm 3 / h, raw flue gas temperature 150°C, moisture content 8% (v / v), SO 2 Concentration 800mg / m 3 , C1 concentration 80mg / m 3 ; Net flue gas SO 2 Concentration 50mg / m 3 , C1 concentration 0mg / m 3 . The ambient temperature is 20°C.

[0033] Such as process flow figure 1 As shown, the raw flue gas from the sintering machine enters the desulfurization wastewater evaporation section 1 through the pipeline (101), and exchanges heat with the 1.92t / h desulfurization wastewater introduced from the pipeline (116). The water in the desulfurization wastewater is evaporated into the The original flue gas, the calcium chloride particle that forms enters dust collector 2 by pipeline (102) along with original flue gas, and flue gas temperature drops to 146.7 ℃ by 150 ℃, and the moisture content of former flue gas increases from 8% (v / v) ...

Embodiment 2

[0038] A 360 square meter sintering machine magnesium oxide wet flue gas desulfurization system, its process parameters are as follows: flue gas volume 1200000Nm 3 / h, raw flue gas temperature 150°C, moisture content 8% (v / v), SO 2 Concentration 800mg / m 3 , C1 concentration 80mg / m 3 ; Net flue gas SO 2 Concentration 50mg / m 3 , C1 concentration 0mg / m 3 . The ambient temperature is 20°C.

[0039] Such as process flow figure 2 As shown, the raw flue gas from the sintering machine enters the desulfurization wastewater evaporation section 1 through the pipeline (201), and exchanges heat with the 2.4t / h desulfurization wastewater introduced from the pipeline (219). The water in the desulfurization wastewater is evaporated into the The raw flue gas generates magnesium salt particles and enters the dust collector 2 from the pipeline (202) along with the raw flue gas, the temperature of the raw flue gas drops from 150°C to 145.9°C, and the moisture content of the raw flue gas i...

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