A method and apparatus for wet desulfurization and denitrification using ferrous complexation

Abstract

This invention provides a wet desulfurization and denitrification method using ferrous complex, comprising the following steps: S1, allowing flue gas to enter the absorption tower from the bottom; S2, allowing an absorbent containing ferrous complex and sulfides to enter the absorption tower from the top, reacting counter-currently with the flue gas entering the absorption tower, obtaining circulating absorbent at the bottom and purified flue gas at the top; S3, sending the circulating absorbent to a regeneration sedimentation tank, adding sulfides, and subjecting it to ultraviolet light irradiation to obtain a regenerated absorbent; S4, sending the regenerated absorbent back to step S2 for use as an absorbent. This invention uses ultraviolet light to achieve the recovery and reuse of ferrous complex, reducing the use of chemical reagents, achieving high absorption efficiency, with a desulfurization rate of over 99% and a denitrification rate of over 94%.

Description

Technical Field

[0001] This invention belongs to the field of gas purification technology, specifically relating to a method and apparatus for wet desulfurization and denitrification using ferrous complexation. Background Technology

[0002] my country is a country that relies heavily on coal as its primary energy source. According to surveys and statistics, over 90% of SO2 and over 67% of NOx in my country are produced from coal. X More than 70% of soot emissions come from coal combustion. Coal combustion produces SO2 and NO... X It is a major source of industrial waste gas pollution (acid rain hazards).

[0003] Currently, selective catalytic reduction (SCR) is the most commonly used method in industry. Traditional combined flue gas desulfurization and denitrification processes typically involve adding a denitrification device, such as selective catalytic reduction (SCR) or selective non-catalytic reduction (SNCR), before the dust collector to achieve combined desulfurization and denitrification.

[0004] Complexed iron removes sulfides and nitrates from flue gas. Fe(II)EDTA is easily oxidized to Fe(III)EDTA, but Fe(III)EDTA cannot complex NO, causing a rapid decrease in absorption efficiency. Biocatalytic reduction can be used to regenerate Fe(II), but this method is currently only in the exploratory stage, and many problems need to be solved before it can be widely applied in waste gas treatment. Regarding the application of reducing agents, hydrazine and H2S reduce Fe(III)EDTA, enhancing the absorption effect of ferrous EDTA; however, because both H2S and hydrazine are toxic, they are difficult to use industrially. Summary of the Invention

[0005] To address the shortcomings of the existing technology, this invention provides a method and apparatus for wet desulfurization and denitrification of ferrous complex. The method and apparatus of this invention can achieve integrated desulfurization and denitrification treatment of flue gas, and are simple to operate. Furthermore, the use of ultraviolet light for the recovery and reuse of ferrous complex reduces the use of chemical reagents, resulting in high absorption efficiency, a desulfurization rate of over 99%, and a denitrification rate of over 94%.

[0006] The first aspect of this invention provides a method for wet desulfurization and denitrification using ferrous complexation, comprising the following steps:

[0007] S1. Allow the flue gas to enter the absorption tower from the bottom of the absorption tower;

[0008] S2. The absorbent containing complexed ferrous oxide and sulfides enters the absorption tower from the top and reacts countercurrently with the flue gas entering the absorption tower. The absorbent is then recycled at the bottom of the tower, and the purified flue gas is obtained at the top of the tower.

[0009] S3. Send the circulating absorbent to the regeneration sedimentation tank, add sulfide, and irradiate with ultraviolet light to obtain the regenerated absorbent.

[0010] S4. The regenerated absorbent is sent to step S2 for use as an absorbent.

[0011] According to some embodiments of the present invention, in step S2, the circulating absorption liquid further includes acetic acid.

[0012] In the technical solution of the present invention, acetic acid can react with free iron ions in the circulating absorption liquid to generate easily soluble iron acetate, thereby improving the utilization rate of iron ions. At the same time, acetic acid can also react with peroxides to reduce the oxidative degradation of the complex by peroxides. Furthermore, the final degradation products of acetic acid are carbon dioxide and water, without the generation of any waste.

[0013] In some preferred embodiments of the present invention, the absorbent liquid further includes acetic acid.

[0014] According to some embodiments of the present invention, in step S2, the molar ratio of the total iron in the absorbent entering the absorption tower per hour to the total NO in the flue gas entering the absorption tower per hour is 2:1 to 5:1.

[0015] In some preferred embodiments of the present invention, the molar ratio of the total iron in the absorbent entering the absorption tower per hour to the total NO in the flue gas entering the absorption tower per hour is 3:1 to 4:1.

[0016] According to some embodiments of the present invention, in step S2, the molar ratio of the total amount of sulfides in the absorbent entering the absorption tower per hour to the total amount of sulfur-containing substances in the flue gas entering the absorption tower per hour is 4:1 to 10:1.

[0017] In some preferred embodiments of the present invention, in step S2, the molar ratio of the total amount of sulfides in the absorbent entering the absorption tower per hour to the total amount of sulfur-containing substances in the flue gas entering the absorption tower per hour is 5:1 to 8:1.

[0018] According to some embodiments of the present invention, in step S2, the total iron concentration in the absorbent is 0.05 to 0.15 mol / L.

[0019] In some preferred embodiments of the present invention, the total iron concentration in the absorbent is 0.08-0.12 mol / L.

[0020] According to some embodiments of the present invention, in step S2, the concentration of the sulfide in the absorbent is 0.09 to 0.15 mol / L.

[0021] According to some embodiments of the present invention, in step S2, the concentration of acetic acid in the absorbent liquid is 0.05 to 0.2 mol / L.

[0022] In some preferred embodiments of the present invention, the concentration of acetic acid in the absorbent is 0.1 to 0.2 mol / L.

[0023] In the technical solution of this invention, by reasonably controlling the total iron concentration, sulfide concentration and acetic acid concentration in the absorbent, the desulfurization and denitrification effect can be guaranteed while further improving the economy.

[0024] According to some embodiments of the present invention, in step S2, the complexing agent for the ferrous complex is selected from one or more of tartaric acid, glycine, and citric acid, and the concentration of the complexing agent is 0.1 to 0.2 mol / L.

[0025] According to some embodiments of the present invention, in step S2, the sulfide is one or a mixture of sodium sulfide, sodium hydrosulfide, ammonium sulfide, and ammonium hydrosulfide; the concentration of the sulfide is 0.1 to 0.3 mol / L.

[0026] According to some embodiments of the present invention, in step S2, after the absorbent enters the absorption tower, it first passes through a liquid distributor for distribution. The liquid distributor can ensure uniform distribution of the liquid in the absorption tower and improve absorption efficiency.

[0027] According to some embodiments of the present invention, in step S3, the ultraviolet light wavelength is 220-270 nm.

[0028] In some preferred embodiments of the present invention, the ultraviolet light wavelength is 240-260 nm.

[0029] According to some embodiments of the present invention, in step S3, the ultraviolet radiation power is 4-10W.

[0030] In some preferred embodiments of the present invention, the ultraviolet light power is 5-8W.

[0031] According to some embodiments of the present invention, in step S4, complexed iron and acetic acid are added to the regenerated circulating absorbent.

[0032] According to some embodiments of the present invention, the method further includes the following steps:

[0033] S5. Filter the sediment in the regeneration sedimentation tank, recover the sediment, and transport the filtrate back to the regeneration sedimentation tank.

[0034] A second aspect of the present invention provides an apparatus for using the method described in the first aspect, comprising an absorption tower, a regeneration sedimentation tank equipped with an ultraviolet light strip, a filter, and a circulation pump; wherein,

[0035] The upper part of the absorption tower is provided with an absorbent liquid inlet and a purified gas outlet, and the bottom part is provided with a flue gas inlet and an absorbent liquid outlet.

[0036] The regeneration sedimentation tank is connected to the absorbent outlet of the absorption tower to receive the circulating absorbent from the absorption tower.

[0037] The filter is connected to the regeneration sedimentation tank and is used to filter the circulating absorbent from the regeneration sedimentation tank;

[0038] The inlet of the circulating pump is connected to the filter, and the outlet is connected to the absorbent inlet of the absorption tower.

[0039] In the technical solution of the present invention, the flue gas enters the absorption tower from the bottom of the absorption tower, and after reacting with the circulating absorbent in the packing layer, it is discharged from the flue gas outlet; the circulating absorbent entering from the top of the absorption tower enters the bottom of the absorption tower after reacting with the flue gas in the packing layer. In the packing tower, the sulfides in the absorbent react with the sulfur dioxide in the gas to generate thiosulfate, and the nitrogen oxides in the flue gas undergo a complexation reaction with the ferrous oxide. The reacted absorbent is then pumped to the regeneration sedimentation tank by a circulating pump.

[0040] In the regeneration settling tank, some ferric ions in the circulating absorbent are reduced to ferrous ions by the added sulfides. Simultaneously, under ultraviolet light irradiation, the ferric ions in the circulating absorbent react to form ferrous complex and hydrogen peroxide. The hydrogen peroxide further oxidizes the sulfites and nitric oxide in the circulating absorbent, producing sulfates and nitrates. The added acetic acid reacts with free iron ions in the absorbent to form easily soluble ferric acetate, improving the utilization rate of iron ions. The regenerated absorbent, along with the added sulfides, ferrous complex, and acetic acid, is pumped into the absorption tower. Insoluble sulfides and nitrates settle to the bottom, are filtered, and the solids are recovered. The filtrate is returned to the regeneration settling tank.

[0041] This invention employs an integrated desulfurization and denitrification method, which is simple and low-cost. In this invention, the combination of ultraviolet light and sulfides further enhances the reduction efficiency of ferrous complex, and the addition of acetic acid improves the utilization rate of iron ions, resulting in a desulfurization rate of over 99% and a denitrification rate of over 94%. Furthermore, ultraviolet light offers advantages such as convenient installation and maintenance, and easily adjustable power and wavelength. In addition, the filtration process further reduces the amount of solid matter in the absorbent, preventing clogging and extending the operating cycle of the device. Attached Figure Description

[0042] Figure 1This is a process flow diagram for wet desulfurization and denitrification using ferrous complexation. Detailed Implementation

[0043] The present invention will be further described below with reference to the accompanying drawings and embodiments. These embodiments are for illustrative purposes only and are not limited to the scope of application of the present invention.

[0044] Example 1

[0045] (1) Experimental procedure:

[0046] The flue gas from the gas distribution tank was analyzed and measured: SO2 concentration was 1150 ppmv, NO concentration was 320 ppmv, and oxygen concentration was 2%v. The flue gas entered from the bottom of the absorption tower and came into countercurrent contact with an aqueous solution containing complexed ferrous iron, acetic acid, and sulfides pumped in by a pump in the packing layer of the absorption tower. The flue gas was desulfurized and denitrified, and the purified flue gas was discharged from the top of the absorption tower.

[0047] The enriched solution after absorption enters a regeneration sedimentation tank for composition analysis. The consumed sulfides, ferrous complexes, and acetic acid are replenished based on the concentration of each substance in the absorption solution. Without ultraviolet light, ferric ions are reduced to ferrous ions by sulfides in the sedimentation tank. Insoluble sulfides, sulfates, and nitrates settle to the bottom of the tank. The solids are then recovered by filtration, and the regenerated solution is returned to the absorption system.

[0048] (2) Test conditions

[0049] Test gas flow rate: 2 Nm 3 / Hour;

[0050] Reaction temperature: 40℃;

[0051] Total iron in the absorbent: 0.10 mol / L;

[0052] Tartaric acid: 0.10 mol / L;

[0053] Citric acid: 0.05 mol / L;

[0054] Sodium sulfide: 0.05 mol / L;

[0055] Sodium hydrosulfide: 0.05 mol / L;

[0056] Acetic acid: 0.05 mol / L;

[0057] Solution circulation rate: 5L / h.

[0058] (3) Experimental Results

[0059] The purified flue gas was analyzed using an infrared spectrometer, and the SO2 concentration was 8 ppmv and the NO concentration was 60 ppmv. The absorbent solution after the reaction was measured, and the total iron content was 0.091 mol / L and the ferrous iron content was 0.0385 mol / L.

[0060] Example 2

[0061] The operating steps are the same as in Example 1, except that the ultraviolet light is turned on and the ultraviolet light power is set to 4W. The SO2 concentration in the flue gas is 1130 ppmv, the NO concentration is 350 ppmv, and the oxygen concentration is 2%v. The purified flue gas is detected using an infrared spectrometer, and the SO2 concentration in the purified gas is 8 ppmv and the NO concentration is 18 ppmv. The absorbent after the reaction is measured, and the total iron content is 0.090 mol / L, and the ferrous iron content is 0.0585 mol / L. Compared with Example 1, the ferrous iron content in the absorbent in this example increases by 0.0200 mol / L.

[0062] Example 3:

[0063] The operating steps were the same as in Example 1, except that ultraviolet light was turned on and the ultraviolet light power was set to 6W. The SO2 concentration in the flue gas was 1120 ppmv, the NO concentration was 330 ppmv, and the oxygen concentration was 2%v. The purified flue gas was detected using an infrared spectrometer, and the SO2 concentration in the purified gas was 7 ppmv and the NO concentration was 16 ppmv. The absorbent after the reaction was measured, and the total iron content was 0.093 mol / L, and the ferrous iron content was 0.0648 mol / L.

[0064] Example 4:

[0065] (1) Experimental procedure:

[0066] The flue gas from the gas distribution tank was analyzed and measured: SO2 concentration was 1180 ppmv, NO concentration was 330 ppmv, and oxygen concentration was 1.9%v. The flue gas enters from the bottom of the absorption tower and comes into countercurrent contact with an aqueous solution containing complexed ferrous iron, acetic acid, and sulfides pumped in by a pump in the packing layer of the absorption tower. The flue gas is desulfurized and denitrified, and the purified flue gas is discharged from the top of the absorption tower.

[0067] The absorbed rich solution enters a regeneration sedimentation tank for composition analysis. The concentrations of each substance in the absorbent solution are used to replenish the consumed sulfides, ferrous complexes, and acetic acid. Ultraviolet light is then applied, reducing ferric ions to ferrous ions in the sedimentation tank. Insoluble sulfides, sulfates, and nitrates settle to the bottom of the tank. The solids are then recovered through filtration, and the regenerated solution is returned to the absorption system.

[0068] (2) Test conditions

[0069] Test gas flow rate: 2 Nm 3 / Hour;

[0070] Reaction temperature: 40℃;

[0071] Total iron in the absorbent: 0.10 mol / L;

[0072] Glycine: 0.08 mol / L;

[0073] Tartaric acid: 0.05 mol / L;

[0074] Ammonium sulfide: 0.08 mol / L;

[0075] UV light power: 8W;

[0076] Ultraviolet light wavelength: 254nm;

[0077] Ammonium hydrosulfide: 0.05 mol / L;

[0078] Acetic acid: 0.15 mol / L;

[0079] Solution circulation rate: 5L / h.

[0080] (3) Test Results

[0081] The purified flue gas was analyzed using an infrared spectrometer, and the SO2 concentration was 6 ppmv and the NO concentration was 12 ppmv. The absorbent after the reaction was measured, and the total iron content was 0.096 mol / L and the ferrous iron content was 0.0687 mol / L.

[0082] Example 5:

[0083] The experimental conditions were the same as in Example 4, except that the total iron content in the absorbent was increased to 0.15 mol / L. The flue gas concentrations were: SO2 1180 ppmv, NO 330 ppmv, and oxygen 1.9%v. The purified flue gas was analyzed using an infrared spectrometer, showing SO2 concentrations of 5 ppmv and NO concentrations of 6 ppmv. The absorbent after the reaction was measured, revealing a total iron content of 0.146 mol / L and a ferrous iron content of 0.1030 mol / L. Compared to Example 4, this example reduced SO2 and NO concentrations in the purified gas by 1 ppmv and 6 ppmv, respectively.

[0084] Example 6:

[0085] (1) Experimental procedure:

[0086] The flue gas from the gas distribution tank was analyzed and measured: SO2 concentration was 1380 ppmv, NO concentration was 390 ppmv, and oxygen concentration was 1.9%v. The flue gas enters from the bottom of the absorption tower and comes into countercurrent contact with an aqueous solution containing complexed ferrous oxide, acetic acid, and sulfides pumped in by a pump in the packing layer of the absorption tower. This process desulfurizes and denitrates the flue gas, which is then discharged from the top of the absorption tower.

[0087] The absorbed rich solution enters a regeneration sedimentation tank for composition analysis. The concentrations of each substance in the absorbent solution are used to replenish the consumed sulfides, ferrous complexes, and acetic acid. Ultraviolet light is then applied, reducing ferric ions to ferrous ions in the sedimentation tank. Insoluble sulfides, sulfates, and nitrates settle to the bottom of the tank. The solids are then recovered through filtration, and the regenerated solution is returned to the absorption system.

[0088] (2) Test conditions

[0089] Test gas flow rate: 2 Nm 3 / Hour;

[0090] Reaction temperature: 44℃;

[0091] Total iron in the absorbent: 0.12 mol / L;

[0092] Glycine: 0.10 mol / L;

[0093] Tartaric acid: 0.07 mol / L;

[0094] Citric acid: 0.05 mol / L;

[0095] Sodium sulfide: 0.05 mol / L;

[0096] UV light power: 10W;

[0097] Ultraviolet light wavelength: 268nm;

[0098] Sodium hydrosulfide: 0.10 mol / L;

[0099] Acetic acid: 0.15 mol / L;

[0100] Solution circulation rate: 5L / h.

[0101] (3) Test Results

[0102] The purified flue gas was analyzed using an infrared spectrometer, and the SO2 concentration was 6 ppmv and the NO concentration was 8 ppmv. The absorbent after the reaction was measured, and the total iron content was 0.1135 mol / L and the ferrous iron content was 0.0805 mol / L.

[0103] Example 7:

[0104] The experimental conditions were the same as in Example 6, except that the sulfide concentration in the absorbent was reduced from 0.15 mol / L to 0.05 mol / L. The flue gas contained 1395 ppmv of SO2, 3850 ppmv of NO, and 2%v of oxygen. The purified flue gas was analyzed using an infrared spectrometer, revealing an SO2 concentration of 95 ppmv and a NO concentration of 8 ppmv. The absorbent after the reaction was measured, showing a total iron content of 0.1126 mol / L and a ferrous iron content of 0.0774 mol / L. Compared to Example 6, the SO2 concentration in the purified gas increased by 89 ppmv in this example.

[0105] Example 8:

[0106] (1) Experimental procedure:

[0107] The flue gas from the gas distribution tank was analyzed and measured: SO2 concentration was 1370 ppmv, NO concentration was 395 ppmv, and oxygen concentration was 1.9%v. The flue gas enters from the bottom of the absorption tower and comes into countercurrent contact with an aqueous solution containing complexed ferrous oxide, acetic acid, and sulfides pumped in by a pump in the packing layer of the absorption tower. This process desulfurizes and denitrates the flue gas, which is then discharged from the top of the absorption tower.

[0108] The absorbed rich solution enters a regeneration sedimentation tank for composition analysis. The concentrations of each substance in the absorbent solution are used to replenish the consumed sulfides, ferrous complexes, and acetic acid. Ultraviolet light is then applied, reducing ferric ions to ferrous ions in the sedimentation tank. Insoluble sulfides, sulfates, and nitrates settle to the bottom of the tank. The solids are then recovered through filtration, and the regenerated solution is returned to the absorption system.

[0109] (2) Test conditions

[0110] Test gas flow rate: 2 Nm 3 / Hour;

[0111] Reaction temperature: 40℃;

[0112] Total iron in the absorbent: 0.12 mol / L;

[0113] Tartaric acid: 0.15 mol / L;

[0114] Citric acid: 0.15 mol / L;

[0115] Ammonium sulfide: 0.10 mol / L;

[0116] UV light power: 8W;

[0117] Ultraviolet light wavelength: 264nm;

[0118] Ammonium hydrosulfide: 0.10 mol / L;

[0119] Acetic acid: 0.20 mol / L;

[0120] Solution circulation rate: 5L / h.

[0121] (3) Test Results

[0122] The purified flue gas was analyzed using an infrared spectrometer, and the SO2 concentration was 6 ppmv and the NO concentration was 7 ppmv. The absorbent after the reaction was measured, and the total iron content was 0.1142 mol / L and the ferrous iron content was 0.0809 mol / L.

[0123] Example 9:

[0124] The experimental conditions were the same as in Example 8, except that acetic acid was not added to the absorbent. The SO2 concentration in the flue gas was 1370 ppmv, the NO concentration was 390 ppmv, and the oxygen concentration was 2%v. The purified flue gas was analyzed using an infrared spectrometer, and the SO2 concentration was 11 ppmv and the NO concentration was 18 ppmv. The absorbent after the reaction was measured, and the total iron content was 0.0931 mol / L, and the ferrous iron content was 0.061 mol / L. Compared with Example 8, the total iron content in the absorbent after the reaction decreased by 0.0211 mol / L, and the ferrous iron content decreased by 0.019 mol / L.

[0125] It should be noted that the embodiments described above are only for explaining the present invention and do not constitute any limitation on the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory terms, not limiting terms. Modifications can be made to the present invention within the scope of the claims, and revisions can be made to the present invention without departing from the scope and spirit of the present invention. Although the present invention described herein relates to specific methods, materials, and embodiments, it does not mean that the present invention is limited to the specific examples disclosed herein; on the contrary, the present invention can be extended to all other methods and applications with the same function.

Claims

1. A method for wet desulfurization and denitrification using ferrous complexation, comprising the following steps: S1. Allow the flue gas to enter the absorption tower from the bottom of the absorption tower; S2. An absorbent containing ferrous complex and sulfide enters the absorption tower from the top and reacts countercurrently with the flue gas entering the absorption tower. A circulating absorbent is obtained at the bottom of the tower, and purified flue gas is obtained at the top of the tower. In step S2, the absorbent contains acetic acid, and the sulfide is one or a mixture of sodium sulfide, sodium hydrosulfide, ammonium sulfide, and ammonium hydrosulfide. The complexing agent in the ferrous complex is selected from one or a mixture of tartaric acid, glycine, and citric acid. S3. The circulating absorbent is sent to the regeneration sedimentation tank, sulfide is added, and ultraviolet light is applied to obtain the regenerated absorbent. In step S3, acetic acid is added to the circulating absorbent. S4. The regenerated absorbent is sent to step S2 for use as an absorbent. In step S4, ferrous complex is added to the regenerated absorbent. S5. Filter the precipitate in the regeneration sedimentation tank, recover the precipitate, and transport the filtrate back to the regeneration sedimentation tank.

2. The method according to claim 1, characterized in that, In step S2, the molar ratio of the total iron content in the absorbent entering the absorption tower per hour to the total NO content in the flue gas entering the absorption tower per hour is 2:1 to 5:1; the molar ratio of the total sulfide content in the absorbent entering the absorption tower per hour to the total sulfur content in the flue gas entering the absorption tower per hour is 4:1 to 10:

1.

3. The method according to claim 2, characterized in that, The molar ratio of the total iron content in the absorbent entering the absorption tower per hour to the total NO content in the flue gas entering the absorption tower per hour is 3:1 to 4:1, and the molar ratio of the total sulfide content in the absorbent entering the absorption tower per hour to the total sulfur content in the flue gas entering the absorption tower per hour is 5:1 to 7:

1.

4. The method according to any one of claims 1-3, characterized in that, In step S2, the total iron concentration in the absorbent is 0.05–0.15 mol / L; and / or the concentration of the sulfide in the absorbent is 0.09–0.15 mol / L; and / or the concentration of the acetic acid in the collected liquid of the circulating absorbent is 0.05–0.2 mol / L.

5. The method according to claim 4, characterized in that, In step S2, the total iron concentration in the absorbent is 0.08-0.12 mol / L; and / or the concentration of acetic acid in the collected solution of the circulating absorbent is 0.1-0.2 mol / L.

6. The method according to any one of claims 1-3, characterized in that, In step S2, the concentration of the complexing agent is 0.1 to 0.2 mol / L; and / or the concentration of the sulfide is 0.1 to 0.3 mol / L.

7. The method according to any one of claims 1-3, characterized in that, In step S2, after the circulating absorbent enters the absorption tower, it is first distributed by a liquid distributor.

8. The method according to any one of claims 1-3, characterized in that, In step S3, the ultraviolet light wavelength is 220-270nm; the ultraviolet light radiation power is 4-10W.

9. The method according to claim 8, characterized in that, The ultraviolet light wavelength is 240-260nm; the ultraviolet light radiation power is 5-8W.

10. An apparatus for the method according to any one of claims 1-9, comprising an absorption tower, a regeneration sedimentation tank equipped with an ultraviolet light strip, a filter, and a circulation pump; wherein, The upper part of the absorption tower is provided with an absorbent liquid inlet and a purified gas outlet, and the bottom part is provided with a flue gas inlet and an absorbent liquid outlet. The regeneration sedimentation tank is connected to the absorbent outlet of the absorption tower to receive the circulating absorbent from the absorption tower. The filter is connected to the regeneration sedimentation tank and is used to filter the circulating absorbent from the regeneration sedimentation tank; The inlet of the circulating pump is connected to the filter, and the outlet is connected to the absorbent inlet of the absorption tower.

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