Ammonium carbamate pyrolytic carbon trapping tower
The use of ammonium carbamate pyrolysis carbon capture tower has solved the problems of high energy consumption at high temperatures and competitive adsorption of carbon dioxide in the urea-to-ammonia process, achieving efficient SCR denitrification and carbon dioxide capture, and reducing system operating costs and environmental impact.
Patent Information
- Application Number
- CN202511138020.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-08-14
- Publication Date
- 2025-12-02
AI Technical Summary
In existing SCR flue gas denitrification technologies, the urea-to-ammonia process requires high temperatures, resulting in high energy costs and competitive adsorption of carbon dioxide on the catalyst surface, which reduces denitrification efficiency, especially in high-concentration CO2 environments.
An ammonium carbamate pyrolysis carbon capture tower is used. A mixture of ammonia and carbon dioxide is generated in the pyrolysis section. After cooling, the carbon dioxide is captured, and only ammonia is allowed to enter the SCR denitrification system. This avoids high-temperature conditions, reduces energy consumption, and improves denitrification efficiency.
It improved the efficiency of the SCR denitrification system by 6% to 24.8%, with an average increase of 15.4%, reduced ammonia production energy consumption by 44.5% to 55.8%, reduced the risk of pipeline blockage and caking, and reduced carbon dioxide emissions.
Smart Images
Figure CN121041973A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of flue gas denitrification technology in coal-fired power plants, specifically to a carbon capture tower for ammonium carbamate pyrolysis. Background Technology
[0002] With the continuous growth of my country's energy demand, coal-fired power plants, as the main source of electricity, have caused serious environmental impacts due to their emissions of pollutants. Among these, NOx emissions from coal-fired boiler flue gas are one of the main sources of NOx pollutants in the atmosphere. In order to effectively control NOx emissions from coal-fired units, selective catalytic reduction (SCR) flue gas denitrification technology has become a widely adopted technical means in my country's power industry due to its mature and efficient characteristics.
[0003] In the SCR flue gas denitrification process, the choice of reducing agent is crucial. Currently, the most commonly used reducing agent for flue gas denitrification is urea. Urea-to-ammonia technology is relatively mature and safe, but it requires high-temperature conditions, which leads to high energy consumption costs for the denitrification system. In addition, carbon dioxide in the mixed gas (including air, carbon dioxide, and ammonia) generated during the traditional urea thermal decomposition process enters the flue gas denitrification system directly without treatment. It competes with the reactants for adsorption on the catalyst surface, especially under high CO2 concentration environments, which significantly reduces denitrification efficiency. Summary of the Invention
[0004] The present invention aims to at least partially solve one of the technical problems in the related art.
[0005] Therefore, embodiments of the present invention propose a carbon capture tower for ammonium carbamate pyrolysis.
[0006] The ammonium carbamate pyrolysis carbon capture tower of this invention includes a tower body, which includes a feeding section, a pyrolysis section, a cooling section, and a carbon capture section arranged sequentially from top to bottom. The feeding section has a feeding port for hot air to carry ammonium carbamate powder into the feeding section. The ammonium carbamate powder in the feeding section enters the pyrolysis section and undergoes pyrolysis to generate a mixture of ammonia and carbon dioxide. The mixture enters the cooling section for cooling, and the cooled mixture enters the carbon capture section to capture the carbon dioxide in the mixture. The carbon capture section has a mixture outlet, through which the carbon-captured mixture is discharged.
[0007] In some embodiments, the pyrolysis section is provided with a plurality of spaced-apart pyrolysis tubes extending along the height of the tower body. The two ends of the pyrolysis tubes are respectively connected to the feeding section and the cooling section. The pyrolysis section is provided with a quicklime inlet, a quicklime outlet, a flue gas inlet, and a flue gas outlet. The quicklime inlet is used for quicklime to enter the pyrolysis section and exit through the quicklime outlet. The flue gas inlet is used for flue gas to enter the pyrolysis section and exit through the flue gas outlet. In the pyrolysis section, carbon dioxide in the flue gas reacts exothermically with quicklime to pyrolyze ammonium carbamate powder flowing through the pyrolysis tubes.
[0008] In some embodiments, an annular water tank is provided on the outer circumferential surface of the pyrolysis section. An overflow plate extending along the height direction of the tower body is provided inside the annular water tank. The bottom end of the overflow plate is connected to the bottom plate of the annular water tank, and the top end of the overflow plate is spaced apart from the top plate of the annular water tank. The overflow plate divides the annular water tank into a water storage chamber and an air passage chamber arranged in the inward and outward directions. The water storage chamber is located outside the air passage chamber. The flue gas inlet is connected to the air passage chamber. The annular water tank is provided with a flue gas inlet connected to the water storage chamber. The flue gas inlet is used for the flue gas discharged from the coal-fired boiler condensing heat exchanger at 50°C to 60°C to enter the water storage chamber and cool it to 20°C to 30°C. The flue gas cooled in the water storage chamber enters the pyrolysis section through the air passage chamber.
[0009] In some embodiments, the pyrolysis section is provided with a plurality of baffles, which are arranged at intervals along the height direction of the tower body. The baffles are inclined at 30° to 40° relative to the horizontal plane. The baffles are provided with clearance holes for the pyrolysis tube to pass through and material passage holes for quicklime to pass through.
[0010] In some embodiments, the feeding section is provided with a fabric plate, and the fabric plate is provided with a plurality of fabric holes arranged at intervals.
[0011] In some embodiments, the temperature of the hot air is 50°C to 80°C.
[0012] In some embodiments, quicklime is provided in the carbon capture section for capturing carbon dioxide in the mixed gas, wherein the quicklime in the pyrolysis section and the carbon capture section has a moisture content of 3% to 5%.
[0013] In some embodiments, the residence time of quicklime in the pyrolysis section is 3 min to 5 min.
[0014] In some embodiments, the cooling section is used to cool the mixed gas after one capture to 30°C to 35°C.
[0015] In some embodiments, the pyrolysis temperature in the pyrolysis tube is 120℃~160℃, the residence time of ammonium carbamate powder in the pyrolysis tube is 10s~15s, and the residence time of flue gas in the pyrolysis section is 15s~30s.
[0016] In this embodiment of the invention, the ammonium carbamate pyrolysis carbon capture tower is used such that ammonium carbamate powder is carried into the feeding section of the tower by hot air through the feeding port, ensuring that the ammonium carbamate powder is evenly distributed within the tower. The ammonium carbamate powder undergoes a pyrolysis reaction in the pyrolysis section, generating a mixture of ammonia and carbon dioxide. This mixture then enters the cooling section to lower its temperature, preparing for subsequent carbon dioxide capture and improving carbon capture efficiency. The cooled mixture then enters the carbon capture section, where carbon dioxide is captured to remove it, allowing only ammonia to pass through the SCR denitrification system.
[0017] The ammonium carbamate pyrolysis carbon capture tower of this invention directly pyrolyzes ammonium carbamate powder and separates carbon dioxide from the pyrolysis gas, allowing only the reducing agent ammonia gas to be directly used in the selective catalytic reduction (SCR) denitrification process. This reduces the competitive adsorption of CO2 on the catalyst surface in the SCR denitrification system, thereby improving the efficiency of the SCR denitrification system. Simultaneously, this invention avoids the high-temperature conditions required in traditional urea-to-ammonia production by directly pyrolyzing ammonium carbamate, thus reducing the energy consumption cost of the denitrification system. Furthermore, this invention effectively avoids the problem of ammonium carbamate easily agglomerating during denitrification due to temperatures approaching or exceeding 25°C, low-temperature high-humidity environments, or drastic temperature fluctuations, reducing the risk of pipeline blockage and decomposition difficulties. Compared with urea-to-ammonia production, this invention improves ammonia production efficiency by 6%–24.8%, with an average improvement of 15.4%, and reduces ammonia production energy consumption by 44.5%–55.8%. Attached Figure Description
[0018] Figure 1 This is a schematic diagram of the structure of the ammonium carbamate pyrolysis carbon capture tower according to an embodiment of the present invention.
[0019] Figure 2 yes Figure 1 Sectional view of AA.
[0020] Figure 3 yes Figure 1 A cross-sectional view of BB.
[0021] Figure 4 yes Figure 1 A sectional view of CC.
[0022] Figure label:
[0023] 1. Tower body; 101. Feeding section; 1011. Feeding port; 102. Pyrolysis section; 1021. Quicklime inlet; 1022. Quicklime outlet; 1023. Flue gas inlet; 1024. Flue gas outlet; 103. Cooling section; 104. Carbon collection section; 1041. Mixed gas outlet; 2. Pyrolysis pipe; 3. Annular water tank; 301. Exhaust gas inlet; 4. Overflow plate; 5. Water storage chamber; 6. Gas passage chamber; 7. Baffle plate; 701. Material passage hole; 8. Material distribution plate; 801. Material distribution hole. Detailed Implementation
[0024] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.
[0025] like Figures 1 to 4 As shown, the ammonium carbamate pyrolysis carbon capture tower of this embodiment of the invention includes a tower body 1, which includes a feeding section 101, a pyrolysis section 102, a cooling section 103, and a carbon capture section 104 arranged sequentially from top to bottom. The feeding section 101 has a feeding port 1011, which is used for hot air to carry ammonium carbamate powder into the feeding section 101. The ammonium carbamate powder in the feeding section 101 enters the pyrolysis section 102 and undergoes pyrolysis to generate a mixture of ammonia and carbon dioxide. The mixture enters the cooling section 103 for cooling, and the cooled mixture enters the carbon capture section 104 to capture carbon dioxide in the mixture. The carbon capture section 104 has a mixture outlet 1041, through which the carbon-captured mixture is discharged.
[0026] In use, the ammonium carbamate pyrolysis carbon capture tower of this embodiment of the invention allows ammonium carbamate powder to be carried into the feeding section 101 of the tower body 1 by hot air through the feeding port 1011, ensuring that the ammonium carbamate powder is evenly distributed within the tower. The ammonium carbamate powder undergoes a pyrolysis reaction in the pyrolysis section 102, generating a mixture of ammonia and carbon dioxide. This mixture then enters the cooling section 103, where its temperature is lowered to prepare for subsequent carbon dioxide capture, thereby improving carbon capture efficiency. The cooled mixture then enters the carbon capture section 104, where carbon dioxide is captured to remove it, allowing only ammonia to pass through the SCR denitrification system.
[0027] The ammonium carbamate pyrolysis carbon capture tower of this invention directly pyrolyzes ammonium carbamate powder and separates carbon dioxide from the pyrolysis gas, allowing only the reducing agent ammonia gas to be directly used in the selective catalytic reduction (SCR) denitrification process. This reduces the competitive adsorption of CO2 on the catalyst surface in the SCR denitrification system, thereby improving the efficiency of the SCR denitrification system. Simultaneously, this invention avoids the high-temperature conditions required in traditional urea-to-ammonia production by directly pyrolyzing ammonium carbamate, thus reducing the energy consumption cost of the denitrification system. Furthermore, this invention effectively avoids the problem of ammonium carbamate easily agglomerating during denitrification due to temperatures approaching or exceeding 25°C, low-temperature high-humidity environments, or drastic temperature fluctuations, reducing the risk of pipeline blockage and decomposition difficulties. Compared with urea-to-ammonia production, this invention improves ammonia production efficiency by 6%–24.8%, with an average improvement of 15.4%, and reduces ammonia production energy consumption by 44.5%–55.8%.
[0028] In some embodiments, such as Figure 1 As shown, the pyrolysis section 102 is equipped with multiple spaced-apart pyrolysis tubes 2, which extend along the height of the tower body 1. The two ends of each pyrolysis tube 2 are connected to the feeding section 101 and the cooling section 103, respectively. The pyrolysis section 102 is equipped with a quicklime inlet 1021, a quicklime outlet 1022, a flue gas inlet 1023, and a flue gas outlet 1024. The quicklime inlet 1021 allows quicklime to enter the pyrolysis section 102 and exit through the quicklime outlet 1022. The flue gas inlet 1023 allows flue gas to enter the pyrolysis section 102 and exit through the flue gas outlet 1024. Within the pyrolysis section 102, carbon dioxide in the flue gas reacts exothermically with the quicklime to pyrolyze the ammonium carbamate powder flowing through the pyrolysis tubes 2.
[0029] Specifically, multiple pyrolysis pipes 2 are installed inside the pyrolysis section 102. These pyrolysis pipes 2 extend along the height of the tower body 1, and their two ends are connected to the feeding section 101 and the cooling section 103, respectively. The arrangement of the pyrolysis pipes 2 helps the ammonium carbamate powder to be heated evenly during the pyrolysis process, and also facilitates the flow of the mixed gas. The pyrolysis section 102 is equipped with a quicklime inlet 1021 and an outlet. Quicklime enters the pyrolysis section 102 through the quicklime inlet 1021 and undergoes an exothermic reaction with carbon dioxide in the flue gas entering through the flue gas inlet 1023 in the pyrolysis section 102 to generate calcium carbonate, which provides heat for the pyrolysis of the ammonium carbamate powder. The quicklime and the generated calcium carbonate after the exothermic reaction are discharged through the quicklime inlet 1021, and the flue gas after the exothermic reaction is discharged through the flue gas outlet 1024.
[0030] The exothermic reaction of quicklime provides additional heat for the pyrolysis of ammonium carbamate, helping to improve pyrolysis efficiency and ammonia production. Integrating the addition of quicklime and the capture of carbon dioxide in flue gas into the pyrolysis section 102 simplifies the entire denitrification and carbon dioxide capture process. This not only achieves the pyrolysis of ammonium carbamate but also reduces carbon dioxide emissions in the flue gas, helping to reduce the environmental impact of coal-fired power plants. The carbon dioxide concentration in the flue gas from coal-fired boilers will decrease by 10%–15%.
[0031] In some embodiments, an annular water tank 3 is provided on the outer circumferential surface of the pyrolysis section 102. An overflow plate 4 extending along the height direction of the tower body 1 is provided inside the annular water tank 3. The bottom end of the overflow plate 4 is connected to the bottom plate of the annular water tank 3, and the top end of the overflow plate 4 is spaced apart from the top plate of the annular water tank 3. The overflow plate 4 divides the annular water tank 3 into a water storage chamber 5 and an air passage chamber 6 arranged in the inward and outward directions. The water storage chamber 5 is located outside the air passage chamber 6, and the flue gas inlet 1023 communicates with the air passage chamber 6. The annular water tank 3 is provided with a flue gas inlet 301 communicating with the water storage chamber 5. The flue gas at 50°C to 60°C discharged from the coal-fired boiler condensing heat exchanger enters the water storage chamber 5 and is cooled to 20°C to 30°C. After being cooled by the water storage chamber 5, the flue gas enters the pyrolysis section 102 through the air passage chamber 6.
[0032] like Figure 1 As shown, specifically, warm flue gas (temperature range of 50℃~60℃) enters the water storage chamber 5 through the flue gas inlet 301. Inside the water storage chamber 5, the flue gas comes into contact with water and exchanges heat, being cooled to 20℃~30℃. The cooled flue gas then enters the air passage chamber 6 through the gap between the overflow plate 4 and the top plate of the annular water tank 3. During this process, due to the separating effect of the overflow plate 4, the flue gas and water are fully contacted, further cooling the flue gas. The cooled flue gas then enters the pyrolysis section 102 through the flue gas inlet 1023, reacting with the quicklime in the pyrolysis section 102. This provides heat for the pyrolysis of ammonium carbamate powder while also capturing carbon dioxide from the flue gas.
[0033] With the annular water tank 3 and overflow plate 4, the flue gas is effectively cooled before entering the pyrolysis section 102, reducing the overall temperature. Since the flue gas is cooled before entering the pyrolysis section 102, the capture efficiency of carbon dioxide in the flue gas by quicklime is improved. Furthermore, cooling the flue gas temperature reduces the internal operating temperature of the pyrolysis section 102, preventing overheating, improving the working environment, and reducing thermal stress on the equipment.
[0034] In some embodiments, the pyrolysis section 102 is provided with a plurality of baffles 7, which are arranged at intervals along the height direction of the tower body 1. The baffles 7 are inclined at 30° to 40° relative to the horizontal plane. The baffles 7 are provided with clearance holes for the pyrolysis pipe 2 to pass through and material passage holes 701 for quicklime to pass through.
[0035] like Figure 1 As shown, the baffle 7 causes the mixed gas to flow back within the pyrolysis section 102, increasing the turbulence of the airflow and facilitating the exothermic reaction between quicklime and flue gas. Due to the tilt angle of the baffle 7 and the airflow reversal, the pyrolysis tube 2 is heated more thoroughly within the pyrolysis section 102, improving the pyrolysis efficiency of ammonium carbamate. The baffle 7 also helps to ensure the uniform distribution of quicklime within the tower body 1, avoiding local overload or uneven distribution, and improving the stability and efficiency of the system.
[0036] In some embodiments, the feeding section 101 is provided with a feeding plate 8, and the feeding plate 8 is provided with a plurality of spaced feeding holes 801. For example, the feeding holes 801 are small square holes with an equivalent diameter of 2 mm to 4 mm.
[0037] like Figure 1 and Figure 2 As shown, when ammonium carbamate powder enters the feeding section 101 through the feeding port 1011, the feeding holes 801 on the feeding plate 8 can evenly disperse the powder across the entire cross-section. The spaced arrangement of the feeding holes 801 helps prevent the ammonium carbamate powder from clogging in the feeding section 101, ensuring that the powder can smoothly enter the pyrolysis section 102. The evenly distributed ammonium carbamate powder can undergo a more efficient pyrolysis reaction in the pyrolysis section 102 because the powder has more sufficient contact with hot air and quicklime.
[0038] Optionally, the temperature of the hot air is 50℃ to 80℃. For example, 50℃, 60℃, or 80℃. Since the pyrolysis reaction of ammonium carbamate requires a certain high temperature to proceed, and the temperature of hot air at 50℃ to 80℃ is insufficient to completely pyrolyze ammonium carbamate, using hot air at a temperature of 50℃ to 80℃ to carry the ammonium carbamate powder can achieve preheating of the ammonium carbamate powder, so that the ammonium carbamate powder can undergo rapid pyrolysis in the pyrolysis tube 2, thereby improving its pyrolysis efficiency.
[0039] In some embodiments, quicklime is provided in the carbon capture section 104 for capturing carbon dioxide in the mixed gas, wherein the quicklime in the pyrolysis section 102 and the carbon capture section 104 has a moisture content of 3% to 5%.
[0040] Within a moisture content range of 3% to 5%, quicklime can more effectively capture carbon dioxide from the mixed gas and flue gas, improving the overall performance of the denitrification system. Appropriate moisture content helps control dust emissions from quicklime, reducing pollution to the environment and equipment. Quicklime with moderate moisture content reacts with carbon dioxide more quickly, improving capture efficiency. Quicklime with stable moisture content helps maintain the stability of the denitrification system, reducing fluctuations during operation.
[0041] In some embodiments, the residence time in the quicklime pyrolysis section 102 is 3 min to 5 min.
[0042] A residence time of 3 to 5 minutes is sufficient to ensure that quicklime reacts fully with carbon dioxide, thereby improving carbon dioxide capture efficiency. Within this residence time range, the system's processing capacity can be optimized, ensuring capture efficiency while avoiding excessive waste of processing capacity. An appropriate residence time helps control energy consumption, as excessive energy is not required to maintain long-term reaction conditions.
[0043] In some embodiments, the cooling section 103 is used to cool the carbon-captured mixture to 30°C to 35°C.
[0044] The cooled gas mixture allows for more efficient carbon dioxide capture in the carbon capture section 104, improving the overall capture efficiency of the denitrification system. The lower temperature also helps reduce ammonia volatilization and leakage, thus minimizing ammonia loss and improving system economics. Appropriate cooling temperatures help optimize energy consumption, as excessive energy is not required to maintain excessively low temperatures. Stable temperatures help maintain the stability of the entire denitrification system, reducing fluctuations during operation.
[0045] In some embodiments, the pyrolysis temperature in the pyrolysis tube 2 is 120°C to 160°C, the residence time of the ammonium carbamate powder in the pyrolysis tube 2 is 10s to 15s, and the residence time of the flue gas in the pyrolysis section 102 is 15s to 30s.
[0046] The pyrolysis temperature is 120℃~160℃, a sufficiently high range to ensure effective pyrolysis of ammonium carbamate powder, producing ammonia and carbon dioxide. Within this temperature range, the pyrolysis reaction rate is moderate, ensuring that the ammonium carbamate powder completes pyrolysis in a relatively short time. Compared to higher pyrolysis temperatures, this temperature range reduces energy consumption because no additional heating equipment is needed to maintain the high temperature.
[0047] The residence time of ammonium carbamate powder in pyrolysis tube 2 is 10 to 15 seconds, which is sufficient to ensure that the powder completes the pyrolysis reaction within the tube. Within this residence time range, the ammonium carbamate powder can be fully pyrolyzed to generate ammonia and carbon dioxide. An appropriate residence time helps maintain the system's processing capacity and avoids reduced processing efficiency due to excessively long residence times.
[0048] The residence time of the flue gas in the pyrolysis section 102 is 15 to 30 seconds, which is sufficient to ensure that the carbon dioxide in the flue gas reacts fully with the quicklime. Within this residence time range, the quicklime can effectively capture the carbon dioxide in the flue gas, improving the capture efficiency. An appropriate residence time helps maintain system stability and reduce fluctuations during operation.
[0049] Optimizing pyrolysis temperature and powder residence time can improve the pyrolysis efficiency of ammonium carbamate, ensuring sufficient ammonia generation for denitrification reactions. Optimizing flue gas residence time can improve the carbon dioxide capture efficiency of quicklime, reducing carbon dioxide emissions. Controlling pyrolysis temperature and residence time can optimize system energy consumption and reduce operating costs. Optimizing residence time can maintain system stability and reduce fluctuations during operation. Improving pyrolysis and capture efficiency helps reduce pollutant emissions from coal-fired power plants, meeting environmental protection requirements.
[0050] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0051] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.
[0052] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0053] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.
[0054] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.
[0055] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.
Claims
1. A carbon capture tower for ammonium carbamate pyrolysis, characterized in that, include: The tower body (1) includes a feeding section (101), a pyrolysis section (102), a cooling section (103), and a carbon capture section (104) arranged sequentially from top to bottom. The feeding section (101) has a feeding port (1011) for hot air to carry ammonium carbamate powder into the feeding section (101). The ammonium carbamate powder in the feeding section (101) enters the pyrolysis section (102) to undergo pyrolysis and generate a mixture of ammonia and carbon dioxide. The mixture enters the cooling section (103) for cooling. The cooled mixture enters the carbon capture section (104) to capture carbon dioxide in the mixture. The carbon capture section (104) has a mixture outlet (1041) through which the carbon-captured mixture is discharged.
2. The ammonium carbamate pyrolysis carbon capture tower according to claim 1, characterized in that, The pyrolysis section (102) is provided with a plurality of spaced pyrolysis tubes (2), which extend along the height of the tower body (1). The two ends of the pyrolysis tubes (2) are connected to the feeding section (101) and the cooling section (103) respectively. The pyrolysis section (102) is provided with a quicklime inlet (1021), a quicklime outlet (1022), a flue gas inlet (1023) and a flue gas outlet (1024). The quicklime inlet (1021) is used for quicklime to enter the pyrolysis section (102) and be discharged through the quicklime outlet (1022). The flue gas inlet (1023) is used for flue gas to enter the pyrolysis section (102) and be discharged through the flue gas outlet (1024). In the pyrolysis section (102), carbon dioxide in the flue gas reacts with quicklime in an exothermic reaction to pyrolyze the ammonium carbamate powder flowing through the pyrolysis tubes (2).
3. The ammonium carbamate pyrolysis carbon capture tower according to claim 2, characterized in that, An annular water tank (3) is provided on the outer circumference of the pyrolysis section (102). An overflow plate (4) extending along the height direction of the tower body (1) is provided inside the annular water tank (3). The bottom end of the overflow plate (4) is connected to the bottom plate of the annular water tank (3), and the top end of the overflow plate (4) is spaced apart from the top plate of the annular water tank (3). The overflow plate (4) divides the annular water tank (3) into a water storage chamber (5) and an air passage chamber (6) arranged in the inner and outer directions. 5) Located outside the gas passage chamber (6), the flue gas inlet (1023) is connected to the gas passage chamber (6). The annular water tank (3) is provided with a flue gas inlet (301) connected to the water storage chamber (5). The flue gas inlet (301) is used to cool the 50℃~60℃ flue gas discharged from the coal-fired boiler condensing heat exchanger into the water storage chamber (5) to 20℃~30℃. The flue gas cooled in the water storage chamber (5) enters the pyrolysis section (102) through the gas passage chamber (6).
4. The ammonium carbamate pyrolysis carbon capture tower according to claim 2, characterized in that, The pyrolysis section (102) is provided with multiple baffles (7), which are arranged at intervals along the height direction of the tower body (1). The baffles (7) are inclined at 30° to 40° relative to the horizontal plane. The baffles (7) are provided with clearance holes for the pyrolysis tube (2) to pass through and material passage holes (701) for quicklime to pass through.
5. The ammonium carbamate pyrolysis carbon capture tower according to claim 1, characterized in that, The feeding section (101) is provided with a feeding plate (8), and the feeding plate (8) is provided with a plurality of feeding holes (801) arranged at intervals.
6. The ammonium carbamate pyrolysis carbon capture tower according to claim 1, characterized in that, The temperature of the hot air is 50℃~80℃.
7. The ammonium carbamate pyrolysis carbon capture tower according to claim 1, characterized in that, The carbon capture section (104) is equipped with quicklime for capturing carbon dioxide in the mixed gas, wherein the quicklime in the pyrolysis section (102) and the carbon capture section (104) has a moisture content of 3% to 5%.
8. The ammonium carbamate pyrolysis carbon capture tower according to claim 1, characterized in that, The residence time of quicklime in the pyrolysis section (102) is 3 min to 5 min.
9. The ammonium carbamate pyrolysis carbon capture tower according to claim 1, characterized in that, The cooling section (103) is used to cool the carbon-captured mixture to 30°C to 35°C.
10. The ammonium carbamate pyrolysis carbon capture tower according to claim 1, characterized in that, The pyrolysis temperature in the pyrolysis tube (2) is 120℃~160℃, the residence time of ammonium carbamate powder in the pyrolysis tube (2) is 10s~15s, and the residence time of flue gas in the pyrolysis section (102) is 15s~30s.