Device for controlling ammonia escape by ammonia desulfurization and decarbonization integration
By designing an integrated ammonia-based desulfurization and decarbonization device, and utilizing a heat pump to cool down and control ammonia escape, the problems of high energy consumption and ammonia escape in the ammonia-based decarbonization process were solved, achieving efficient carbon dioxide absorption and energy utilization, and promoting the application of ammonia-based carbon capture technology.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ASIA PACIFIC ENVIRONMENTAL CORP
- Filing Date
- 2025-04-09
- Publication Date
- 2026-06-09
AI Technical Summary
In the process of ammonia decarbonization, how to effectively utilize the heat and moisture of the desulfurized tail gas, reduce energy consumption and ammonia escape, and solve the problem of increased process costs.
An integrated ammonia-based desulfurization and decarbonization device was designed, including a desulfurization absorption tower, a decarbonization absorption tower, a demister, and a heat pump. The heat pump cools the desulfurized flue gas, the condensate is used for ammonia demisting, and the pH adjustment system controls ammonia escape, thereby achieving efficient energy utilization and water balance maintenance.
It achieved a carbon dioxide absorption efficiency of over 85% and an ammonia slip concentration of less than 3 mg/m3, reducing production energy consumption, making rational use of energy, and promoting the application and industrialization of ammonia-based carbon capture technology.
Smart Images
Figure CN224331843U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of flue gas treatment technology, and in particular to a device for integrated control of ammonia escape in ammonia-based desulfurization and decarbonization. Background Technology
[0002] With the booming development of global industry and economy, human demand for energy is constantly rising, and traditional fossil fuels still dominate the energy mix. The combustion of fossil fuels releases large amounts of carbon dioxide (CO2), exacerbating global warming. Global CO2 emissions from the energy sector have been increasing almost every year, primarily due to the combustion of fossil fuels such as coal, oil, and natural gas. From 2000 to 2022, the average concentration of CO2 in the global atmosphere increased from 370 ppm to 418 ppm. To reduce CO2 emissions globally and achieve the goal of limiting the rise in global average temperature to within 2°C, many countries have formulated carbon reduction policies. With the introduction of my country's strategic goals such as "peak carbon and carbon neutrality", the National Development and Reform Commission and other departments issued the "Action Plan for Low-Carbon Transformation and Construction of Coal-fired Power Plants (2024-2027)", which clearly benchmarks against the carbon emission levels of natural gas power generation units. It requires that by 2025 and 2027, the carbon emissions of coal-fired power plant low-carbon transformation and construction projects should be reduced by about 20% and 50% respectively compared with the average carbon emission level of similar coal-fired power units in 2023.
[0003] Carbon capture, utilization, and storage (CCUS) is one of the key technologies for achieving near-zero CO2 emissions. Among these technologies, ammonia-based decarbonization uses ammonia water as the CO2 capture and absorbent because it overcomes many of the shortcomings of MEA solutions. It also offers advantages such as low cost, easy availability, and low regeneration energy consumption. Furthermore, the heat of reaction between CO2 and ammonia water is relatively low, approximately 70 kJ / mol, significantly lower than the approximately 90 kJ / mol heat of reaction between CO2 and MEA. This means that using ammonia water requires less energy to regenerate the same amount of CO2. In addition, ammonia water can also achieve the combined removal of nitrogen oxides (NOx) and sulfur dioxide (SO2). The generated ammonium sulfate, ammonium nitrate, and ammonium bicarbonate produced during decarbonization can be used as agricultural fertilizers, making it an important solution for the next generation of carbon capture and resource utilization (CCUS) technologies.
[0004] Although ammonia-based carbon capture technology has shown several advantages over other carbon capture technologies, further reducing energy consumption and minimizing ammonia escape remain major challenges. Therefore, effectively utilizing the heat and moisture in the flue gas after desulfurization (where the gas is already saturated with moisture) to reduce production energy consumption and address the increased process costs caused by the volatilization of high-concentration ammonia during ammonia-based decarbonization are pressing technical challenges that need to be overcome. Utility Model Content
[0005] The technical problem to be solved by this utility model is to provide a device for integrated control of ammonia escape in ammonia desulfurization and decarbonization.
[0006] To solve the above-mentioned technical problems, the technical solution of this utility model is as follows:
[0007] An integrated ammonia desulfurization and decarbonization control device for controlling ammonia escape includes a desulfurization absorption tower, a decarbonization absorption tower, a demister, and a heat pump unit. 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 connected to the flue gas inlet of the decarbonization absorption tower via a flue gas pipe. The exhaust port of the decarbonization absorption tower is connected to the flue gas inlet of the demister via a pipe. The demister is equipped with, from bottom to top, a first-stage ammonia demister, a second-stage ammonia demister, a high-efficiency demister, and a super demister. The heat pump unit is connected to the flue gas pipe to cool the flue gas within the pipe. The condensate pipe of the heat pump unit is connected to the demister circulation tank. The demister circulation tank is connected to the first-stage ammonia demister via a first-stage decarbonization demister pipe, and the first-stage ammonia demister is connected to the demister circulation tank via a return pipe.
[0008] Preferably, it also includes a pH adjustment system for adjusting the acidity or alkalinity of the condensate in the demister circulation tank.
[0009] Preferably, the pH adjustment system uses the absorbent from the desulfurization system or dilute sulfuric acid for adjustment.
[0010] Preferably, the increased amount of acidic washing liquid from the first-stage ammonia demister is sent to the desulfurization absorption tower as process makeup water; the increased amount of washing water from the second-stage ammonia demister is sent to the desulfurization absorption tower or the decarbonization absorption tower as process makeup water, thereby achieving a water balance in the desulfurization and decarbonization process and preventing the discharge of wastewater.
[0011] Preferably, the decarbonization absorption tower is provided with two absorption layers, namely an empty tower spray layer and a second packing layer. The empty tower spray layer absorbs the liquid until it reaches supersaturation or near saturation and then sends it outside the tower for cooling and crystallization into ammonium bicarbonate. The ammonium bicarbonate crystal slurry is then sent to the post-treatment system. The second packing layer controls the absorbent liquid to be unsaturated and returns it to the first absorbent liquid.
[0012] The above technical solution has the following advantages:
[0013] This invention utilizes a heat pump to cool the desulfurized flue gas, and uses the condensate generated during the flue gas cooling process as water for the primary ammonia demister. The absorbent from the desulfurization system or dilute sulfuric acid is used to adjust the pH of the condensate, thus solving the problem of ammonia escape in ammonia-based carbon capture. The heat recovered by the heat pump can be used in other production processes, such as heating demineralized water in coal-fired boilers, achieving efficient energy utilization and reducing energy consumption. Through these methods, this invention solves the water balance imbalance problem caused by flue gas directly entering the decarbonization absorption tower during the decarbonization process, while simultaneously reducing ammonia escape and production energy consumption. Its reasonable structural design achieves a carbon dioxide absorption efficiency of over 85%, contributing to the engineering application and industrialization of ammonia-based carbon capture technology. Attached Figure Description
[0014] Figure 1 This is a simplified structural diagram of one embodiment of the present utility model;
[0015] In the picture:
[0016] 1-Untreated flue gas, 2-pH adjustment system, 3-Desulfurization absorption tower, 4-Desulfurization absorption circulating oxidation tank, 5-Heat pump unit, 6-Demisting tower circulation tank, 7-Flue gas pipeline, 8-Decarbonization absorption tower, 9-Ammonium bicarbonate post-treatment, 10-Decarbonization absorption circulation tank, 11-Decarbonization stage demister pipeline, 12-Demisting tower, 13-Second stage ammonia demister, 14-First stage ammonia demister, 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
[0017] The specific embodiments of this utility model will be further described below with reference to the accompanying drawings. It should be noted that these descriptions are for the purpose of aiding understanding of this utility model, but do not constitute a limitation thereof. Furthermore, the technical features involved in the various embodiments of this utility model described below can be combined with each other as long as they do not conflict with each other.
[0018] Example
[0019] As attached Figure 1As shown, an integrated ammonia desulfurization and decarbonization control device for controlling ammonia escape includes a desulfurization absorption tower 3, a decarbonization absorption tower 8, a demister tower 12, and a heat pump unit 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 connected to the flue gas inlet of the decarbonization absorption tower 8 via a flue gas pipe 7; the exhaust port of the decarbonization absorption tower 8 is connected to the flue gas inlet of the demister tower 12 via a pipe; the demister tower 12 extends from bottom to top... The device is equipped with a first-stage ammonia demister 14, a second-stage ammonia demister 13, a high-efficiency demister 16, and a super demister 17 in sequence. The heat pump device 5 is connected to the flue gas duct 7 to cool the flue gas in the flue gas duct 7. The condensate pipe 19 of the heat pump device 5 is connected to the demister tower circulation tank 6. The demister tower circulation tank 6 is connected to the first-stage ammonia demister 14 through the first-stage decarbonization water washing demister pipe 11. The demister liquid recovered by the first-stage ammonia demister 14 is connected to the demister tower circulation tank 6 through the return pipe 15.
[0020] As a further improvement to this embodiment, in order to accurately control the pH value of the condensate and better achieve the capture and recovery of ammonia in the flue gas, a pH adjustment system 2 is also included for adjusting the pH value of the condensate in the demister circulation tank 6. The pH adjustment system 2 can employ existing technology, such as a CpH-2-L type automatic pH control liquid dispenser. The pH adjustment system 2 precisely adjusts the pH value of the condensate in the demister circulation tank 6 by detecting the pH value and adding absorbent liquid or dilute sulfuric acid from the desulfurization system.
[0021] In this embodiment, the heat pump device 5 uses existing equipment. The intermediate condenser of the heat pump device 5 cools the flue gas, while the waste heat recovery device is used to output heat to other production processes, such as heating the demineralized water in a coal-fired boiler, to achieve heat energy recovery and utilization, thereby reducing energy consumption. The high-efficiency demister 16 can be a ridge-type demister or other demisters, and the super demister 17 can be a wire mesh demister or other demisters. The absorbent liquid after carbon dioxide adsorption in the decarbonization absorption tower 8 can undergo ammonium bicarbonate post-treatment 9, which can be achieved using existing technology to realize carbon dioxide recovery and utilization. Accordingly, the equipment in this embodiment, such as the desulfurization absorption tower 3 and the decarbonization absorption tower 8, which are not specifically described, are all existing technologies and will not be elaborated further.
[0022] The working principle of this utility model is as follows:
[0023] After desulfurization by the desulfurization absorption tower 3, the saturated flue gas enters the heat pump unit 5 to cool it to 18-23℃. Simultaneously, the condensate enters the demister circulation tank 6. The condensate in the demister circulation tank 6 is used to provide demisting water for the first-stage ammonia demister 14, realizing the capture and recovery of ammonia in the decarbonized flue gas. The cooled flue gas enters the decarbonization absorption tower 8 for decarbonization and then enters the demister 12. The flue gas is captured and recovered by the ammonia in the first-stage ammonia demister 14 and the second-stage ammonia demister 13. The acidic washing liquid of the first-stage ammonia demister 14 is increased and sent to the desulfurization absorption tower 3 as process makeup water. The washing water of the second-stage ammonia demister 13 is increased and sent to the decarbonization absorption tower 8 as process makeup water, realizing the water balance of the desulfurization and decarbonization process and preventing the discharge of wastewater. The deammed flue gas passes through the high-efficiency demister 16 and the super demister 17 and is discharged through the flue gas outlet 18 of the demister 12. In this example, the high-efficiency demister 16 is a ridge-type demister, and the super demister 17 is a wire mesh demister.
[0024] In this example, the operating temperature of the absorbent in the decarbonization absorption tower 8 is 18–25°C. The decarbonization absorption tower 8 has two absorption layers: a first-stage empty tower spray layer (not shown in the figure) and a second-stage packing layer (not shown in the figure). The pH of the absorbent in the first-stage empty tower spray layer is 8–12; the pH of the absorbent in the second-stage packing layer is 9–10; the spray liquid-to-gas ratio in the first-stage empty tower spray layer is 6–20 L / m³. 3 The gas velocity is 0.6–2.0 m / s, and the spray liquid-to-gas ratio of the two-stage packing layer is 6–15 L / m. 3 The system absorbs carbon dioxide-containing flue gas under conditions of a gas velocity of 0.6–2.0 m / s. The first-stage empty tower spray layer absorbs the gas until it reaches supersaturation or near saturation, then sends it outside the tower for cooling and crystallization into ammonium bicarbonate. The ammonium bicarbonate slurry is then sent to the post-treatment system. The second-stage packing layer controls the absorbent to remain unsaturated and returns it to the first-stage absorbent. The second-stage packing layer uses low-resistance, anti-clogging, high-specific-surface-area, high-efficiency packing.
[0025] Repeated sampling was conducted, and the flue gas discharged from the flue gas outlet 18 of the demister 12 was tested. The carbon dioxide absorption rate in the flue gas was not less than 85.1%, and the ammonia slip concentration was less than 3 mg / m³. 3 .
[0026] In the description of the above embodiments, for the sake of brevity and clarity, some components and their specific structural details that are not directly related to the core innovations of this utility model have been omitted. These omitted parts all fall within the scope of existing technology, and those skilled in the art can fully implement the design and manufacture of these parts based on their professional knowledge and existing technical materials. Therefore, they will not be described in detail here.
[0027] The embodiments of this utility model have been described in detail above with reference to the accompanying drawings, but this utility model is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions, and variations can be made to these embodiments without departing from the principles and spirit of this utility model, and these variations still fall within the protection scope of this utility model.
Claims
1. An integrated device for controlling ammonia escape in ammonia desulfurization and decarbonization, comprising a desulfurization absorption tower (3), a decarbonization absorption tower (8), a demister (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 connected to the flue gas inlet of the decarbonization absorption tower (8) through a flue gas pipe (7); the exhaust port of the decarbonization absorption tower (8) is connected to the flue gas inlet of the demister (12) through a pipe; the demister (12) is provided with a first-stage ammonia demister (14), a second-stage ammonia demister (13), a high-efficiency demister (16), and a super demister (17) sequentially from bottom to top; characterized in that: The heat pump device (5) is connected to the flue gas pipe (7) to cool the flue gas in the flue gas pipe (7); the condensate pipe (19) of the heat pump device (5) is connected to the demisting tower circulation tank (6), the demisting tower circulation tank (6) is connected to the first-stage ammonia demisting device (14) through the first-stage decarbonization demisting pipe (11), and the first-stage ammonia demisting device (14) is connected to the demisting tower circulation tank (6) through the return pipe (15).
2. The device for integrated control of ammonia slip in ammonia desulfurization and decarbonization according to claim 1, characterized in that: It also includes a pH adjustment system (2) for adjusting the acidity or alkalinity of the condensate in the circulation tank (6) of the demister.
3. The device for integrated control of ammonia slip in ammonia desulfurization and decarbonization according to claim 2, characterized in that: The pH adjustment system (2) is adjusted by the absorbent or dilute sulfuric acid in the desulfurization system.
4. The device for integrated control of ammonia slip in ammonia desulfurization and decarbonization according to claim 1, characterized in that: The increased amount of acidic washing liquid from the first-stage ammonia demister (14) is sent to the desulfurization absorption tower (3) as process makeup water; the increased amount of washing water from the second-stage ammonia demister (13) is sent to the desulfurization absorption tower (3) or the decarbonization absorption tower (8) as process makeup water, so as to achieve a water balance in the desulfurization and decarbonization process without discharging wastewater.
5. The device for integrated control of ammonia slip in ammonia desulfurization and decarbonization according to claim 4, characterized in that: The decarbonization absorption tower (8) is provided with two absorption layers, namely an empty tower spray layer and a second packing layer. The empty tower spray layer absorbs the liquid until it reaches supersaturation or near saturation and sends it outside the tower to cool and crystallize ammonia bicarbonate. The ammonia bicarbonate crystal slurry is sent to the post-treatment system. The second packing layer controls the absorbent liquid to be unsaturated and returns it to the first absorbent liquid.