Method and device for integrally controlling ammonia escape through ammonia desulfurization and decarbonization
Through the integrated ammonia desulfurization and decarbonization system combining desulfurization and absorption towers, decarbonization absorption towers, defog towers and heat pump devices, the problems of high energy consumption and ammonia escape during the ammonia decarbonization process are solved, efficient carbon dioxide absorption and energy reuse are achieved, and the application of ammonia carbon capture technology is promoted.
Patent Information
- Application Number
- CN202510438122.7
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-04-09
- Publication Date
- 2025-07-08
AI Technical Summary
During the ammonia decarbonization process, how to effectively utilize the heat and moisture of the desulfurized exhaust gas to reduce energy consumption and reduce ammonia escape, and solve the problem of increased process costs.
The integrated ammonia desulfurization and decarbonization system consisting of a desulfurization and absorption tower, a decarbonization absorption tower, a defog tower and a heat pump device is adopted to cool the flue gas through the heat pump device and use condensate water to capture ammonia. Combined with the pH adjustment system, the pH level of the condensed water in the circulation tank of the defog tower is optimized to achieve efficient recovery of ammonia and energy reuse.
The carbon dioxide absorption efficiency is achieved by up to 85%, and the ammonia escape concentration is less than 3mg/m3, which reduces production energy consumption and optimizes the water balance, and promotes the engineering application and industrial development of ammonia carbon capture technology.
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Figure CN120268186A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of flue gas treatment, and particularly relates to a method and device for integrated ammonia desulfurization and decarbonization to control ammonia slip. Background Art
[0002] With the vigorous development of global industry and economy, the demand for energy by humans has been continuously climbing, and traditional fossil fuels still dominate the energy field. The combustion of fossil fuels releases a large amount of carbon dioxide (CO2), exacerbating the trend of global warming, and the CO2 emissions of the global energy industry have been continuously increasing almost every year, mainly from the combustion of fossil energy such as coal, oil, and natural gas. From 2000 to 2022, the average concentration of CO2 in the global atmosphere has increased from 370 ppm to 418 ppm. In order to reduce CO2 emissions globally and achieve the goal of controlling the increase in the global average temperature within 2 °C, many countries have formulated carbon emission reduction policies. The National Development and Reform Commission and other departments issued the "Action Plan for the Low-Carbon Transformation and Construction of Coal-Fired Power Plants (2024-2027)", clearly benchmarking the carbon emission levels of natural gas-fired power generation units, and requiring that by 2025 and 2027, the carbon emissions of coal-fired power plant low-carbon transformation and construction projects be reduced by about 20% and 50% respectively compared with the average carbon emissions of similar coal-fired power generation units in 2023.
[0003] Carbon capture, utilization, and storage technology (CCUS) is one of the key technologies to achieve near-zero CO2 emissions. Among them, the ammonia-based decarbonization technology uses ammonia water as the CO2 capture absorbent because it can overcome many disadvantages of MEA solution, and at the same time has the advantages of low cost, easy availability, and low regeneration energy consumption. Moreover, the reaction heat of CO2 and ammonia water is relatively low, about 70 kJ / mol, significantly lower than the reaction heat of CO2 and MEA which is about 90 kJ / mol. This means that under the condition of regenerating the same amount of CO2, the energy consumption using ammonia water is lower. In addition, ammonia water can also achieve the combined removal of nitrogen oxides (NOx) and sulfur dioxide (SO2), and the generated ammonium sulfate, ammonium nitrate, and ammonium bicarbonate produced by decarbonization can be used as agricultural fertilizers, becoming an important solution for the new generation of carbon capture and resource utilization (CCUS) technology.
[0004] Although the ammonia-based carbon capture technology shows many advantages compared with other carbon capture technologies, further reducing the energy consumption of carbon capture and reducing ammonia slip are still the main challenges faced currently. On this basis, how to effectively utilize the heat and moisture in the flue gas after desulfurization (at this time, the moisture in the flue gas is in a saturated state) during the decarbonization process, so as to achieve the purpose of reducing production energy consumption, and solve the problem of increased process costs caused by the volatilization of high-concentration ammonia water during the ammonia-based decarbonization process is a technical problem that needs to be urgently solved at present. Summary of the Invention
[0005] The technical problem to be solved by the present invention is to provide a method and device for integrated control of ammonia escape in ammonia-based desulfurization and decarbonization.
[0006] To solve the above technical problems, the technical solution of the present invention is as follows:
[0007] An apparatus for integrated control of ammonia escape in ammonia-based desulfurization and decarbonization, comprising a desulfurization absorption tower, a decarbonization absorption tower, a demisting tower and a heat pump device; the desulfurization absorption tower is connected to a desulfurization absorption circulating oxidation tank; the decarbonization absorption tower is connected to a decarbonization absorption circulating tank; the exhaust port of the desulfurization absorption tower is communicated with the flue gas inlet of the decarbonization absorption tower through a flue gas pipeline; the smoke exhaust port of the decarbonization absorption tower is communicated with the flue gas inlet of the demisting tower through a pipeline; the demisting tower is sequentially provided with a first-stage ammonia demisting device, a second-stage ammonia demisting device, a high-efficiency demister and a super demister from bottom to top; the heat pump device is connected to the flue gas pipeline to realize the cooling of the flue gas in the flue gas pipeline; the condensate pipeline of the heat pump device is connected to a demisting tower circulating tank, the demisting tower circulating tank is connected to the first-stage ammonia demisting device through a decarbonization first-stage demisting pipeline, and the first-stage ammonia demisting device is connected to the demisting tower circulating tank through a return pipe.
[0008] Preferably, it further includes a pH adjustment system for adjusting the pH value of the condensate in the demisting tower circulating tank.
[0009] Preferably, in the pH adjustment system, it is adjusted by the absorption liquid or dilute sulfuric acid in the desulfurization system.
[0010] A method for integrated control of ammonia escape in ammonia-based desulfurization and decarbonization, which uses the above-mentioned device, and the method is as follows:
[0011] After the flue gas is desulfurized by passing through the desulfurization absorption tower, the desulfurized saturated flue gas enters the heat pump device to cool the flue gas to 18-28 °C, and at the same time the precipitated condensate enters the demisting tower circulating tank. The condensate in the demisting tower circulating tank is used to provide demisting water for the first-stage ammonia demisting device, realizing the ammonia capture and recovery in the flue gas after decarbonization; the cooled desulfurized flue gas first enters the decarbonization absorption tower for decarbonization and then enters the demisting tower. After the ammonia in the flue gas is captured and recovered by the first-stage ammonia demisting device and the second-stage ammonia demisting device, it is discharged through the flue gas outlet of the demisting tower after passing through the high-efficiency demister and the super demister.
[0012] Preferably, the increased amount of the acidic washing liquid of the first-stage ammonia demisting device is sent to the desulfurization absorption tower as process make-up water; the increased amount of the washing water of the second-stage ammonia demisting device is sent to the desulfurization absorption tower or the decarbonization absorption tower as process make-up water, realizing the balance of the desulfurization and decarbonization process water level without discharging sewage; the first-stage ammonia demisting device and the second-stage ammonia demisting device are provided with high-efficiency packing, and the washing spray intensity is 5-20m 3 / m 2 ·h.
[0013] Preferably, two absorption layers are provided in the decarbonization absorption tower, namely a first empty tower spray layer and a second packing layer. The first empty tower spray layer reaches supersaturated crystallization or near saturation through absorption and is sent outside the tower for cooling crystallization to form ammonium bicarbonate, and the ammonium bicarbonate crystal slurry is sent to the post-treatment system; the second packing layer controls the absorption liquid to be unsaturated and refluxes it into the first absorption liquid.
[0014] Preferably, the second packing layer uses high-efficiency packing with low resistance, anti-blocking, and large specific surface area.
[0015] Preferably, the working temperature of the absorption liquid in the decarbonization absorption tower is 18 - 28 °C, where the pH of the absorption liquid in the first empty tower spray layer in the decarbonization absorption tower is 8 - 12; the pH of the absorption liquid in the second packing layer is 8 - 10.
[0016] Preferably, in the decarbonization absorption tower, the absorption liquid containing ammonia water is pumped to the absorption spray layer and atomized and sprayed by a nozzle. The first empty tower spray layer adopts a spray liquid-gas ratio of 6 - 20 L / m 3 , the gas velocity is 0.6 - 2.0 m / s, and the second packing layer adopts a spray liquid-gas ratio of 6 - 15 L / m 3 , and the flue gas containing carbon dioxide is absorbed under the condition that the gas velocity is 0.6 - 2.0 m / s.
[0017] Adopting the above technical solution, the following advantages are achieved:
[0018] The present invention uses a heat pump device to cool the flue gas after desulfurization, uses the condensed water generated during the cooling process of the flue gas as the water for the primary ammonia demisting device, and uses the absorption liquid or dilute sulfuric acid in the desulfurization system to adjust the pH of the condensed water, solving the problem of ammonia escape in ammonia-based decarbonization. The heat recovered by the heat pump device can be used in other production links, such as heating the demineralized water in a coal-fired boiler, realizing the effective utilization of energy and reducing energy consumption. In the above way, the present invention solves the problem of imbalance of the water balance caused by the direct entry of the flue gas into the decarbonization absorption tower during the decarbonization process, and at the same time reduces ammonia escape and production energy consumption. Its structural design is reasonable, and the carbon dioxide absorption efficiency can reach more than 85%, which helps to promote the engineering application and industrial development of ammonia-based carbon capture technology. BRIEF DESCRIPTION OF THE DRAWINGS
[0019] Figure 1 is a structural schematic diagram of one embodiment of the present invention;
[0020] In the figure:
[0021] 1 - Untreated flue gas, 2 - pH adjustment system, 3 - Desulfurization absorption tower, 4 - Desulfurization absorption circulation oxidation tank, 5 - Heat pump device, 6 - Demisting tower circulation tank, 7 - Flue gas pipeline, 8 - Decarbonization absorption tower, 9 - Post - treatment of ammonium bicarbonate, 10 - Decarbonization absorption circulation tank, 11 - First - stage ammonia demisting pipeline for decarbonization, 12 - Demisting tower, 13 - Second - stage ammonia demisting device, 14 - First - stage ammonia demisting device, 15 - Return pipe, 16 - High - efficiency demister, 17 - Super demister, 18 - Flue gas outlet, 19 - Condensate pipeline, 20 - Process water, 21 - Demineralized water. Detailed implementation manners
[0022] The following further explains the detailed implementation manners of the present invention in conjunction with the attached drawings. It should be noted here that the description of these implementation manners is used to help understand the present invention, but does not constitute a limitation to the present invention. In addition, the technical features involved in the following various implementation manners of the present invention can be combined with each other as long as they do not conflict with each other.
[0023] Embodiment 1
[0024] As shown in the attached Figure 1 figures, a device for integrated control of ammonia escape in ammonia - based desulfurization and decarbonization includes a desulfurization absorption tower 3, a decarbonization absorption tower 8, a demisting tower 12 and a heat pump device 5; the desulfurization absorption tower 3 is connected to a desulfurization absorption circulation oxidation tank 4; the decarbonization absorption tower 8 is connected to a decarbonization absorption circulation tank 10; the exhaust port of the desulfurization absorption tower 3 is communicated with the flue gas inlet of the decarbonization absorption tower 8 through a flue gas pipeline 7; the smoke exhaust port of the decarbonization absorption tower 8 is communicated with the flue gas inlet of the demisting tower 12 through a pipeline; the demisting tower 12 is sequentially provided with a first - stage ammonia demisting device 14, a second - stage ammonia demisting device 13, a high - efficiency demister 16 and a super demister 17 from bottom to top; the heat pump device 5 is connected to the flue gas pipeline 7 to realize the cooling of the flue gas in the flue gas pipeline 7; the condensate pipeline 19 of the heat pump device 5 is connected to a demisting tower circulation tank 6, the demisting tower circulation tank 6 is connected to the first - stage ammonia demisting device 14 through a first - stage decarbonization water washing and demisting pipeline 11 for decarbonization, and the demisting liquid recovered by the first - stage ammonia demisting device 14 is connected to the demisting tower circulation tank 6 through a return pipe 15.
[0025] As a further improved technical solution of this embodiment, in order to accurately control the pH value of the condensate and better realize the capture and recovery of ammonia in the flue gas, it further includes a pH adjustment system 2 for adjusting the pH value of the condensate in the demisting tower circulation tank 6. The pH adjustment system 2 can adopt existing technologies, such as using a CpH - 2 - L type pH automatic control liquid adding machine. The pH adjustment system 2 accurately adjusts the pH value of the condensate in the demisting tower circulation tank 6 by detecting the pH value of the condensate in the demisting tower circulation tank 6 and adding the absorption liquid or dilute sulfuric acid in the desulfurization system.
[0026] In this embodiment, the heat pump device 5 uses existing equipment. The condenser in the heat pump device 5 cools the flue gas, and the waste heat recovery device is used to output heat to other production processes, such as heating the desalted water in the coal-fired boiler to realize the recovery and utilization of thermal energy and reduce energy consumption. The high-efficiency demister 16 can be a roof-type demister or other demisters, and the super demister 17 can be a wire mesh demister or other demisters. The absorption liquid after the decarbonization absorption tower 8 adsorbs carbon dioxide can be subjected to ammonium bicarbonate post-treatment 9, which can be achieved by using existing technologies, to realize the recovery and utilization of carbon dioxide. Correspondingly, the desulfurization absorption tower 3, decarbonization absorption tower 8 and other equipment not specifically described in this embodiment are all existing technologies and will not be elaborated here.
[0027] Embodiment 2
[0028] A method for controlling ammonia slip in integrated ammonia-based desulfurization and decarbonization, which uses the device described in Embodiment 1, is as follows:
[0029] After the flue gas is desulfurized by passing through the desulfurization absorption tower 3, the desulfurized saturated flue gas enters the heat pump device 5 to cool the flue gas to 18 - 25°C. At the same time, the condensed water separated out enters the demister tower circulation tank 6, and the condensed water in the demister tower circulation tank 6 is used to provide demisting water for the primary ammonia demister device 14, realizing the capture and recovery of ammonia in the flue gas after decarbonization. The cooled flue gas enters the decarbonization absorption tower 8 for decarbonization and then enters the demister tower 12. The flue gas is subjected to ammonia capture and recovery by the primary ammonia demister device 14 and the secondary ammonia demister device 13. And the increased amount of the acidic washing liquid of the primary ammonia demister device 14 is sent to the desulfurization absorption tower 3 as process makeup water; the increased amount of the washing water of the secondary ammonia demister 13 is sent to the decarbonization absorption tower 8 as process makeup water, realizing the balance of the desulfurization and decarbonization process levels without discharging sewage. The flue gas after ammonia demisting passes through the high-efficiency demister 16 and the super demister 17 and is discharged through the flue gas outlet 18 of the demister tower 12. In this example, the high-efficiency demister 16 is a roof-type demister, and the super demister 17 is a wire mesh demister.
[0030] In this example, the primary ammonia demister device 14 and the secondary ammonia demister device 13 are provided with high-efficiency packing, and the washing spray intensity is 5 - 20m 3 / m 2 ·h. The working temperature of the absorption liquid in the decarbonization absorption tower 8 is 18 - 25°C. Two absorption layers are provided in the decarbonization absorption tower 8, namely a primary empty tower spray layer and a secondary packing layer. The pH of the absorption liquid in the primary empty tower spray layer is 8 - 12, and the pH of the absorption liquid in the secondary packing layer is 8 - 10; the spray liquid-gas ratio in the primary empty tower spray layer is 6 - 20L / m 3 , the gas velocity is 0.8m / s, and the spray liquid-gas ratio of the secondary packing layer is 6 - 15L / m 3, absorb the flue gas containing carbon dioxide under the condition that the gas velocity is 0.8 m / s. The first empty tower spray layer reaches supersaturated crystallization or near saturation through absorption and is sent out of the tower for cooling crystallization to form ammonium bicarbonate, and the ammonium bicarbonate crystal slurry is sent to the post-treatment system; the second packing layer controls the absorption liquid to be unsaturated and returns it to the absorption liquid in the first stage. The second packing layer adopts high-efficiency packing with low resistance, anti-blocking, and large specific surface area.
[0031] Repeat sampling multiple times. By detecting the flue gas discharged from the flue gas outlet 18 of the demisting tower 12, in this embodiment, the absorption rate of carbon dioxide is not less than 85.1%, and the concentration of ammonia escape is less than 3 mg / m 3 .
[0032] Example 3
[0033] A method for integrated ammonia desulfurization and decarbonization to control ammonia escape, which uses the device described in Example 1. The method is as follows:
[0034] After the flue gas is desulfurized by passing through the desulfurization absorption tower 3, the desulfurized saturated flue gas enters the heat pump device 5 to cool the flue gas to 24 - 28 °C. At the same time, the condensed water precipitated enters the demisting tower circulation tank 6. The condensed water in the demisting tower circulation tank 6 is used to provide demisting water for the first-stage ammonia demisting device 14, realizing the ammonia capture and recovery in the flue gas after decarbonization; the cooled flue gas enters the decarbonization absorption tower 8 for decarbonization and then enters the demisting tower 12. The flue gas is subjected to ammonia capture and recovery by the first-stage ammonia demisting device 14 and the second-stage ammonia demisting device 13, and the increased amount of acidic washing liquid of the first-stage ammonia demisting device 14 is sent to the desulfurization absorption tower 3 as process makeup water; the increased amount of washing water of the second-stage ammonia demister 13 is sent to the decarbonization absorption tower 8 as process makeup water, realizing the balance of the desulfurization and decarbonization process levels without discharging sewage. The ammonia-free flue gas is discharged through the high-efficiency demister 16 and the super demister 17 and then through the flue gas outlet 18 of the demisting tower 12. In this example, the high-efficiency demister 16 is a roof-type demister, and the super demister 17 is a wire mesh demister.
[0035] In this example, the first-stage ammonia demisting device 14 and the second-stage ammonia demisting device 13 are provided with high-efficiency packing, and the washing spray intensity is 5 - 20 m 3 / m 2 ·h. The working temperature of the absorption liquid in the decarbonization absorption tower 8 is 24 - 28 °C. Two absorption layers are provided in the decarbonization absorption tower 8, namely the first empty tower spray layer and the second packing layer. The pH of the absorption liquid in the first empty tower spray layer is 8 - 12, and the pH of the absorption liquid in the second packing layer is 8 - 10. The first empty tower spray layer adopts a spray liquid-gas ratio of 6 - 20 L / m 3 , the gas velocity is 1.5 m / s, and the spray liquid-gas ratio of the second packing layer is 6 - 15 L / m 3, absorb the flue gas containing carbon dioxide under the condition that the gas velocity is 1.5 m / s. The first empty tower spraying layer reaches supersaturated crystallization or near saturation through absorption and is sent outside the tower for cooling crystallization to form ammonium bicarbonate, and the ammonium bicarbonate crystal slurry is sent to the post-treatment system; the second packing layer controls the absorption liquid to be unsaturated and refluxes to the absorption liquid in the first stage. The second packing layer adopts high-efficiency packing with low resistance, anti-blocking and large specific surface area.
[0036] Repeat sampling multiple times, and detect the flue gas discharged from the flue gas outlet 18 of the demisting tower 12. In this embodiment, the absorption rate of carbon dioxide is not less than 85.3%, and the concentration of ammonia escape is less than 3 mg / m 3 .
[0037] During the description of the above embodiments, in order to make the description of the specification concise and clear, some components that have no direct relation to the core innovation points of the present invention and their specific structural details are omitted. These omitted parts all belong to the existing technical scope, and for those skilled in the art, based on their professional knowledge and existing technical materials, they can completely realize the design and manufacture of these parts. Therefore, no further detailed description will be given here.
[0038] The embodiments of the present invention have been described in detail above in conjunction with the accompanying drawings, but the present invention is not limited to the described embodiments. For those skilled in the art, without departing from the principle and spirit of the present invention, various changes, modifications, substitutions and variations made to these embodiments still fall within the protection scope of the present invention.
Claims
1. An integrated ammonia desulfurization and decarbonization device for controlling ammonia slip, comprising a desulfurization absorption tower (3), a decarbonization absorption tower (8), a demisting tower (12) and a heat pump device (5); the desulfurization absorption tower (3) is connected to a desulfurization absorption circulating oxidation tank (4); the decarbonization absorption tower (8) is connected to a decarbonization absorption circulating tank (10); the exhaust port of the desulfurization absorption tower (3) is communicated with the flue gas inlet of the decarbonization absorption tower (8) through a flue gas pipeline (7); the smoke exhaust port of the decarbonization absorption tower (8) is communicated with the flue gas inlet of the demisting tower (12) through a pipeline; the demisting tower (12) is sequentially provided with a first-stage ammonia demisting device (14), a second-stage ammonia demisting device (13), a high-efficiency demister (16) and a super demister (17) from bottom to top; characterized in that: The heat pump device (5) is connected to the flue gas pipeline (7) to cool the flue gas in the flue gas pipeline (7); the condensate pipeline (19) of the heat pump device (5) is connected to the demisting tower circulation tank (6), and the demisting tower circulation tank (6) is connected to the first-stage ammonia demisting device (14) through the decarbonization first-stage demisting pipeline (11), and the first-stage ammonia demisting device (14) is connected to the demisting tower circulation tank (6) through the reflux pipe (15).
2. The device for integrated ammonia desulfurization and decarbonization to control ammonia slip according to claim 1, characterized in that: It further includes a pH adjustment system (2) for adjusting the pH value of the condensate in the demisting tower circulation tank (6).
3. The device for integrated ammonia desulfurization and decarbonization to control ammonia slip according to claim 2, characterized in that: In the pH adjustment system (2), it is adjusted by the absorption liquid or dilute sulfuric acid in the desulfurization system.
4. A method for integrated control of ammonia escape in ammonia-based desulfurization and decarbonization, characterized in that Using the device according to any one of claims 1-3, the method is as follows: After the flue gas is desulfurized by passing through the desulfurization absorption tower (3), the desulfurized saturated flue gas enters the heat pump device (5) to cool the flue gas to 18-28°C. At the same time, the condensed water separated out enters the demisting tower circulation tank (6). The condensed water in the demisting tower circulation tank (6) is used to provide demisting water for the first-stage ammonia demisting device (14) to realize the ammonia capture and recovery in the flue gas after decarbonization. The cooled desulfurized flue gas first enters the decarbonization absorption tower (8) for decarbonization and then enters the demisting tower (12). After the ammonia in the flue gas is captured and recovered by the first-stage ammonia demisting device (14) and the second-stage ammonia demisting device (13), it passes through the high-efficiency demister (16) and the super demister (17) and is discharged through the flue gas outlet (18) of the demisting tower (12).
5. The method for integrated ammonia desulfurization and decarbonization to control ammonia slip according to claim 4, characterized in that: The increased amount of acidic washing liquid of the first-stage ammonia demisting device (14) is sent to the desulfurization absorption tower (3) as process makeup water; the increased amount of washing water of the second-stage ammonia demisting device (13) is sent to the desulfurization absorption tower (3) or the decarbonization absorption tower (8) as process makeup water, so as to achieve the process water balance of desulfurization and decarbonization without discharging sewage externally; the first-stage ammonia demisting device (14) and the second-stage ammonia demisting device (13) are provided with high-efficiency fillers, and the washing spray intensity is 5-20 m 3 / m 2 ·h.
6. The method for integrated ammonia desulfurization and decarbonization to control ammonia slip according to claim 5, characterized in that: Two absorption layers are arranged in the decarbonization absorption tower (8), namely the first-stage empty tower spraying layer and the second-stage packing layer. The first-stage empty tower spraying layer reaches supersaturation crystallization or near saturation through absorption and is sent to the outside of the tower for cooling crystallization to form ammonium bicarbonate, and the ammonium bicarbonate crystal slurry is sent to the post-treatment system. The second-stage packing layer controls the absorption liquid to be unsaturated and refluxes to the first-stage absorption liquid.
7. The method for integrally controlling ammonia slip in ammonia-based desulfurization and decarbonization according to claim 6, characterized in that: The second-stage packing layer uses high-efficiency packing with low resistance, anti-blocking and large specific surface area.
8. The method for integrated control of ammonia slip in ammonia-based desulfurization and decarbonization according to claim 7, characterized in that: The working temperature of the absorption liquid in the decarbonization absorption tower (8) is 18-28°C, wherein the pH value of the absorption liquid in the first-stage empty tower spraying layer in the decarbonization absorption tower (8) is 8-12; the pH value of the absorption liquid in the second-stage packing layer is 8-10.
9. The method for integrated ammonia desulfurization and decarbonization to control ammonia slip according to claim 8, wherein: In the decarbonization absorption tower (8), the absorption liquid containing ammonia water is pumped to the absorption spray layer by a pump and atomized and sprayed by a spray head. The spray liquid-gas ratio of the first empty tower spray layer is 6-20 L / m 3 , the gas velocity is 0.6-2.0 m / s, and the spray liquid-gas ratio of the second packing layer is 6-15 L / m 3 , and the flue gas containing carbon dioxide is absorbed under the condition that the gas velocity is 0.6-2.0 m / s.