Ammonia carbamate pyrolysis coupling carbon capture device

Abstract

The invention discloses an ammonia carbamate pyrolysis coupling carbon capture device which comprises a tower body, a discharging pipe, a water inlet pipe and an exhaust pipe. According to the method, the ammonium carbamate powder is directly pyrolyzed by utilizing heat generated by an exothermic reaction of the quick lime and the slaked lime water, and only the reducing agent ammonia gas is allowed to be directly used in a selective catalytic reduction (SCR) denitration process, so that competitive adsorption of carbon dioxide on the surface of a catalyst in an SCR denitration system is reduced, and the efficiency of the SCR denitration system is improved. Meanwhile, the high-temperature condition needed in the traditional urea ammonia preparation process is avoided, and the problem that ammonium carbamate is prone to caking in the low-temperature and high-humidity or severe-temperature-fluctuation environment due to the fact that the temperature is close to or exceeds 25 DEG C in the denitration process is effectively solved. Compared with urea ammonia preparation, the ammonia preparation efficiency is improved by 6%-24.8% and averagely improved by 15.40%, the ammonia preparation energy consumption is reduced by 38.2%-40.6%, and meanwhile, the denitration efficiency of the generated mixed gas entering the flue gas selective catalytic denitration reactor can be improved by 3.5%-4.2%.

Description

Technical Field

[0001] This invention relates to the field of flue gas denitrification technology in coal-fired power plants, specifically to a carbamate pyrolysis coupled carbon capture device. Background Technology

[0002] 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) produced during the traditional urea thermal decomposition process enters the flue gas denitrification system directly without treatment. It will compete with the reactants for adsorption on the catalyst surface, especially in high-concentration carbon dioxide environments, which will reduce denitrification efficiency.

[0003] Furthermore, in related technologies, to address the limitations of existing urea-to-ammonia technology, a method using ammonium carbamate, an intermediate product in urea production, as the main denitrification agent has been proposed, offering a cost advantage. However, ammonium carbamate is prone to agglomeration during selective catalytic denitrification of flue gas, leading to problems such as pipeline blockage and decomposition difficulties. 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 provide a carbamate pyrolysis coupled carbon capture device.

[0006] The carbamate pyrolysis coupled carbon capture device of this invention includes a tower body, a feed pipe, a water inlet pipe, and an exhaust pipe. The tower body includes a pyrolysis section and a carbon capture section arranged from top to bottom. The feed pipe and the water inlet pipe are both located along the tower body. The feed pipe is used to transport a mixture of ammonium carbamate powder and quicklime into the pyrolysis section. The water inlet pipe is used to transport slaked lime water into the pyrolysis section. The slaked lime water and quicklime react exothermically in the pyrolysis section to pyrolyze the ammonium carbamate powder to generate carbon dioxide and ammonia pyrolysis gas. The reacted slaked lime water and pyrolysis gas enter the carbon capture section. In the carbon capture section, the carbon dioxide in the pyrolysis gas reacts with the slaked lime water to generate calcium carbonate precipitate. The exhaust pipe is located in the tower body. The first end of the exhaust pipe is below the liquid surface of the slaked lime water in the carbon capture section, and the second end of the exhaust pipe is outside the tower body. The exhaust pipe is used to discharge the pyrolysis gas after carbon capture.

[0007] In some embodiments, both the feed pipe and the water inlet pipe are arranged vertically, the water inlet pipe is coaxial with the tower body, and there are multiple feed pipes arranged at intervals along the circumference of the water inlet pipe.

[0008] In some embodiments, the carbamate pyrolysis coupled carbon capture device further includes an atomizing tube, which is disposed within the pyrolysis section and connected to the water inlet pipe. The atomizing tube is perpendicular to the water inlet pipe and has a plurality of atomizing holes arranged at intervals.

[0009] In some embodiments, the axis of the atomizing hole forms an angle of 30° to 45° with the vertical direction and is obliquely downward, the inner diameter of the atomizing hole is 2mm to 5mm, and the flow velocity of the atomizing hole is 15m / s to 25m / s.

[0010] In some embodiments, the number of atomizing tubes is multiple, the multiple atomizing tubes are divided into multiple atomizing layers, the multiple atomizing layers are arranged at intervals along the height direction of the tower body, and the atomizing layer includes multiple atomizing tubes arranged at intervals along the circumference of the water inlet pipe.

[0011] In some embodiments, the included angle between two adjacent atomizing tubes in the atomizing layer is 45° to 60°.

[0012] In some embodiments, the carbamate pyrolysis coupled carbon capture device further includes an air inlet pipe, which includes a main pipe and an air distribution pipe. The main pipe is located in the tower body, with a first end inside the carbon capture section and a second end outside the tower body. The air distribution pipe is located inside the carbon capture section and below the liquid surface of the quicklime water. The air distribution pipe has a plurality of spaced air distribution holes. The air inlet pipe supplies air to the carbon capture section to agitate the quicklime water.

[0013] In some embodiments, the number of air distribution pipes is multiple and they are arranged at intervals along the circumference of the tower body. The air inlet pipe is used to transport low-pressure air of 0.1 MPa to 0.2 MPa. The inner diameter of the air distribution hole is 2 mm to 6 mm, and the flow velocity of the air distribution hole is 20 m / s to 25 m / s.

[0014] In some embodiments, the carbamate pyrolysis coupled carbon capture device further includes a storage tank, the carbon capture section has a discharge port, the discharge port is connected to the storage tank, the discharge port is used to discharge quicklime water and calcium carbonate precipitate in the carbon capture section into the storage tank, the storage tank is connected to the water inlet pipe through a delivery pump to transport the quicklime water in the storage tank to the water inlet pipe.

[0015] In some embodiments, the residence time of ammonium carbamate powder in the pyrolysis section is 8s to 12s, and the pyrolysis temperature in the pyrolysis section is 100℃ to 120℃.

[0016] The ammonium carbamate pyrolysis coupled carbon capture device of this invention directly pyrolyzes ammonium carbamate powder using the heat generated by the exothermic reaction of quicklime and slaked lime water, and separates carbon dioxide from the pyrolysis gas. Only the reducing agent ammonia is allowed to be directly used in the selective catalytic reduction (SCR) denitrification process, thereby reducing the competitive adsorption of carbon dioxide on the catalyst surface in the SCR denitrification system and improving the efficiency of the SCR denitrification system. Simultaneously, this invention avoids the high-temperature conditions required in the traditional urea-to-ammonia process 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 the denitrification process due to temperatures close to or exceeding 25°C, low temperature and high humidity, or drastic temperature fluctuations, reducing the risk of pipeline blockage and decomposition difficulties. Compared with urea-to-ammonia production, the present invention improves ammonia production efficiency by 6% to 24.8%, with an average improvement of 15.40%, and reduces ammonia production energy consumption by 38.2% to 40.6%. At the same time, the denitrification efficiency of the mixed gas entering the flue gas selective catalytic denitrification reactor can be improved by 3.5% to 4.2%. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the structure of the carbamate pyrolysis coupled carbon capture device according to an embodiment of the present invention.

[0018] Figure 2 yes Figure 1 Sectional view of AA.

[0019] Figure 3 yes Figure 1 A cross-sectional view of BB.

[0020] Figure 4 yes Figure 1 A sectional view of CC.

[0021] Figure label: 1. Tower body; 101. Pyrolysis section; 102. Carbon collection section; 1021. Discharge port; 2. Feed pipe; 3. Water inlet pipe; 4. Exhaust pipe; 5. Atomizing pipe; 501. Atomizing hole; 6. Air inlet pipe; 601. Main pipe; 602. Air distribution pipe; 6021. Air distribution hole; 7. Storage tank. Detailed Implementation

[0022] 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.

[0023] like Figures 1 to 4As shown, the carbamate pyrolysis coupled carbon capture device of this embodiment includes a tower body 1, a feed pipe 2, a water inlet pipe 3, and an exhaust pipe 4. The tower body 1 includes a pyrolysis section 101 and a carbon capture section 102 arranged from top to bottom. The feed pipe 2 and the water inlet pipe 3 are both located along the tower body 1. The feed pipe 2 is used to transport a mixture of ammonium carbamate powder and quicklime into the pyrolysis section 101, and the water inlet pipe 3 is used to transport slaked lime water into the pyrolysis section 101. The slaked lime water and quicklime react exothermically in the pyrolysis section 101, pyrolyzing the ammonium carbamate powder to generate carbon dioxide and ammonia pyrolysis gas. The reacted slaked lime water and pyrolysis gas then enter the carbon capture section 102. In the carbon capture section 102, the carbon dioxide in the pyrolysis gas reacts with the slaked lime water to generate calcium carbonate precipitate. The exhaust pipe 4 is located in the tower body 1. The first end of the exhaust pipe 4 is below the liquid surface of the quicklime water in the carbon collection section 102, and the second end of the exhaust pipe 4 is located outside the tower body 1. The exhaust pipe 4 is used to discharge the pyrolysis gas after carbon collection.

[0024] In this embodiment of the invention, the ammonium carbamate pyrolysis coupled carbon capture device operates by mixing ammonium carbamate powder with quicklime and feeding it into the pyrolysis section 101 of the tower body 1 through the feed pipe 2. In the pyrolysis section 101, quicklime water supplied by the water inlet pipe 3 reacts with the quicklime in an exothermic reaction, generating heat to pyrolyze the ammonium carbamate, producing a mixed gas of carbon dioxide and ammonia. The generated pyrolysis gas then enters the carbon capture section 102 of the tower body 1. In the carbon capture section 102, the carbon dioxide in the pyrolysis gas reacts with the quicklime water to form a water-insoluble calcium carbonate precipitate, thereby achieving carbon dioxide capture. After carbon capture treatment, the pyrolysis gas is discharged from the tower body 1 through the exhaust pipe 4. The exhaust pipe 4 ensures that the calcium carbonate precipitate in the quicklime water is not carried away, while also ensuring the smooth discharge of the pyrolysis gas.

[0025] The ammonium carbamate pyrolysis coupled carbon capture device of this invention directly pyrolyzes ammonium carbamate powder using the heat generated by the exothermic reaction of quicklime and slaked lime water, and separates carbon dioxide from the pyrolysis gas. Only the reducing agent ammonia is allowed to be directly used in the selective catalytic reduction (SCR) denitrification process, thereby reducing the competitive adsorption of carbon dioxide on the catalyst surface in the SCR denitrification system and improving the efficiency of the SCR denitrification system. Simultaneously, this invention avoids the high-temperature conditions required in the traditional urea-to-ammonia process 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 the denitrification process due to temperatures close to or exceeding 25°C, low temperature and high humidity, or drastic temperature fluctuations, reducing the risk of pipeline blockage and decomposition difficulties. Compared with urea-to-ammonia production, the present invention improves ammonia production efficiency by 6% to 24.8%, with an average improvement of 15.40%, and reduces ammonia production energy consumption by 38.2% to 40.6%. At the same time, the denitrification efficiency of the mixed gas entering the flue gas selective catalytic denitrification reactor can be improved by 3.5% to 4.2%.

[0026] In some embodiments, both the feed pipe 2 and the water inlet pipe 3 are arranged in a vertical direction, the water inlet pipe 3 is coaxial with the tower body 1, and there are multiple feed pipes 2 arranged at intervals along the circumference of the water inlet pipe 3.

[0027] The feed pipes 2 are spaced circumferentially along the water inlet pipes 3, ensuring that the mixture of ammonium carbamate powder and quicklime is uniformly fed into the pyrolysis section 101. This uniform distribution contributes to the uniformity of the pyrolysis reaction, avoiding localized overheating or incomplete reaction. The coaxial arrangement of the water inlet pipes 3 and the tower body 1 simplifies the structure of the tower body 1, reducing manufacturing and installation complexity. Simultaneously, this arrangement contributes to more stable flow of pyrolysis gas and quicklime water, improving system reliability. Due to the arrangement of the feed pipes 2 and water inlet pipes 3, the mixing of ammonium carbamate powder and quicklime water is more thorough, contributing to improved pyrolysis efficiency and carbon capture efficiency. The multiple feed pipes 2 increase operational flexibility. The feed rate of each feed pipe 2 can be adjusted as needed to adapt to different operating conditions and denitrification requirements. Distributing the feed through multiple feed pipes 2 reduces the risk of pipe blockage due to material accumulation or uneven flow. The uniform distribution of the feed pipes 2 results in a more uniform heat distribution within the pyrolysis section 101, contributing to improved efficiency and safety of the pyrolysis reaction. The uniformly distributed feed pipe 2 helps the carbon dioxide in the pyrolysis gas to fully contact with the quicklime water, thereby improving carbon capture efficiency and reducing carbon dioxide emissions.

[0028] In some embodiments, the carbamate pyrolysis coupled carbon capture device further includes an atomizing tube 5, which is disposed in the pyrolysis section 101 and connected to the water inlet pipe 3. The atomizing tube 5 is perpendicular to the water inlet pipe 3 and has a plurality of atomizing holes 501 arranged at intervals.

[0029] The atomizing tube 5 is located inside the pyrolysis section 101 and connected to the water inlet pipe 3. This ensures that the quicklime water is atomized upon entering the pyrolysis section 101, forming fine water droplets and increasing the contact area with the mixture of ammonium carbamate powder and quicklime. The perpendicular positioning of the atomizing tube 5 to the water inlet pipe 3 helps create a three-dimensional atomization effect, allowing the quicklime water to evenly cover the entire pyrolysis section 101. The atomizing tube 5 has multiple spaced atomizing holes 501, allowing control of the atomization effect through the size and arrangement of the holes 501, ensuring that the size and distribution of the water droplets meet the requirements of pyrolysis and carbon capture.

[0030] The atomizing tube 5 atomizes quicklime water into fine droplets, improving the mixing efficiency with the mixture of ammonium carbamate powder and quicklime, and promoting the pyrolysis reaction. The atomized droplets better absorb the heat generated during pyrolysis, enhancing heat exchange efficiency and contributing to improved pyrolysis temperature uniformity. The atomized droplets also better capture carbon dioxide produced during pyrolysis, reacting fully with the quicklime water to form calcium carbonate precipitate, thereby improving carbon capture efficiency. By optimizing the pyrolysis and carbon capture processes, the overall system energy consumption can be reduced, and energy utilization efficiency improved. The uniform atomization effect helps prevent pipe blockage caused by material drying or agglomeration. The atomizing tube 5 helps maintain system operational stability and reduces system performance degradation due to operational fluctuations.

[0031] In some embodiments, the axis of the atomizing hole 501 forms an angle of 30° to 45° with the vertical direction and is obliquely downward, the inner diameter of the atomizing hole 501 is 2mm to 5mm, and the flow velocity of the atomizing hole 501 is 15m / s to 25m / s.

[0032] The atomizing orifice 501 is angled downwards at 30° to 45° with the vertical direction. This arrangement helps the atomized water droplets form a spiral or rotating flow within the pyrolysis section 101, increasing the contact opportunities between the water droplets and the mixture of ammonium carbamate powder and quicklime, thus improving mixing efficiency. The inner diameter of the atomizing orifice 501 is 2mm to 5mm. This size range produces water droplets of an appropriate size—neither too large to be insufficiently mixed, nor too small to easily evaporate or be carried away by the airflow. The flow velocity of the atomizing orifice 501 is 15m / s to 25m / s. This velocity range ensures that the water droplets have sufficient momentum when leaving the atomizing orifice 501 to fully disperse within the pyrolysis section 101 and cover a larger area.

[0033] Therefore, the downward-sloping atomizing orifice 501 helps water droplets form a rotating flow within the pyrolysis section 101. This flow enhances the mixing of water droplets with the ammonium carbamate and quicklime mixture, promoting the pyrolysis reaction. Appropriate inner diameter and flow velocity of the atomizing orifice 501 produce uniform and fine water droplets, which helps improve atomization and allows for better mixing of the droplets with the pyrolysis gas, thereby increasing carbon capture efficiency. Optimizing the atomizing orifice 501 can reduce pipe blockage and corrosion caused by excessively large or uneven atomization. The rotating flow of atomized water droplets within the pyrolysis section 101 facilitates heat exchange, making the pyrolysis process more uniform and efficient. By adjusting the angle, inner diameter, and flow velocity of the atomizing orifice 501, the behavior of the water droplets, including their size, distribution, and trajectory, can be precisely controlled, thereby optimizing the entire denitrification and carbon capture process. This atomizing orifice 501 configuration can adapt to different operating conditions and processes, such as variations in temperature, pressure, and material flow rate, improving the system's flexibility and reliability.

[0034] In some embodiments, there are multiple atomizing tubes 5, which are divided into multiple atomizing layers. The multiple atomizing layers are arranged at intervals along the height direction of the tower body 1, and each atomizing layer includes multiple atomizing tubes 5 arranged at intervals along the circumference of the water inlet pipe 3.

[0035] like Figure 1 and Figure 3 As shown, there are multiple atomizing tubes 5, which provides more atomization points, thus forming a more uniform atomization coverage throughout the pyrolysis section 101. The multiple atomizing tubes 5 are divided into multiple atomization layers, arranged at intervals along the height direction of the tower body 1. This layered arrangement helps to achieve atomization at different heights, ensuring that the material throughout the pyrolysis section 101 is fully atomized. The atomizing tubes 5 in each atomization layer are arranged at intervals along the circumference of the water inlet pipe 3, thus achieving a uniform atomization effect in the horizontal direction.

[0036] Therefore, the multiple atomizing tubes 5 arranged in layers can provide atomization at different heights, ensuring that the material throughout the pyrolysis section 101 is uniformly mixed with the atomized water droplets. Uniform atomization helps improve the efficiency of the pyrolysis reaction and also facilitates the full reaction of carbon dioxide with quicklime water, improving carbon capture efficiency. Layered atomization helps improve the temperature distribution within the tower 1, avoiding local overheating or cooling, thereby optimizing the pyrolysis reaction conditions. Due to the better atomization effect, the amount of quicklime water used can be reduced, thus reducing energy consumption and operating costs. The layered arrangement increases system redundancy; even if one layer of atomizing tubes 5 malfunctions, the atomizing tubes 5 in other layers can still operate normally, ensuring system reliability.

[0037] In some embodiments, the included angle between two adjacent atomizing tubes 5 in the atomizing layer is 45° to 60°. Setting the included angle between adjacent atomizing tubes 5 to 45° to 60° provides a range that offers good coverage while maintaining atomization uniformity. This angle helps achieve a uniform spatial distribution of the atomizing tubes 5, allowing the atomized water droplets to cover the entire cross-sectional area of ​​the pyrolysis section 101.

[0038] Therefore, the angle between adjacent atomizing tubes 5 ensures a more uniform distribution of atomized water droplets within the pyrolysis section 101, facilitating thorough mixing of ammonium carbamate powder and atomized water droplets. Uniform atomization improves denitrification efficiency, as the denitrification reaction requires sufficient humidity to ensure effective reaction of ammonia with nitrogen oxides in the flue gas. Uniformly distributed atomized water droplets better capture and react with carbon dioxide produced during pyrolysis, thus improving carbon capture efficiency. More uniform atomization reduces the amount of quicklime water used, lowering energy consumption and improving the overall system's energy efficiency. Uniform atomization also helps reduce pipe blockage and scaling problems caused by localized over-wetting. By adjusting the angle between adjacent atomizing tubes 5, different operating conditions and denitrification requirements can be accommodated, improving the system's operational flexibility.

[0039] In some embodiments, the carbamate pyrolysis coupled carbon capture device further includes an air inlet pipe 6, which includes a main pipe 601 and an air distribution pipe 602. The main pipe 601 is located in the tower body 1, with its first end inside the carbon capture section 102 and its second end outside the tower body 1. The air distribution pipe 602 is located inside the carbon capture section 102 and below the liquid surface of the quicklime water. The air distribution pipe 602 has a plurality of spaced-apart air distribution holes 6021. The air inlet pipe 6 supplies air into the carbon capture section 102 to agitate the quicklime water.

[0040] like Figure 1 and Figure 4 As shown, the air inlet pipe 6 includes a main pipe 601 and an air distribution pipe 602. The main pipe 601 is located in the tower body 1, connecting the inside and outside of the carbon collection section 102. The air distribution pipe 602 is located inside the carbon collection section 102 and below the liquid surface of the quicklime water. The air distribution pipe 602 has a plurality of spaced air distribution holes 6021 for supplying air into the quicklime water inside the carbon collection section 102.

[0041] Air intake pipe 6 supplies air into carbon capture section 102, effectively agitating the quicklime water and ensuring more uniform calcium carbonate precipitation, preventing precipitate buildup and clumping. Agitation allows carbon dioxide in the air to more fully contact and react with the quicklime water, forming calcium carbonate precipitate and improving carbon capture efficiency. Air agitation helps maintain the uniformity and reactivity of the quicklime water, optimizing carbon capture reaction conditions. Agitation also helps prevent precipitates in carbon capture section 102 from clogging pipes and equipment, ensuring stable system operation. Optimizing the carbon capture reaction reduces the amount of quicklime water used, thus lowering energy consumption. The inclusion of air intake pipe 6 increases system redundancy; even if some air distribution holes 6021 become blocked, others can continue to operate, ensuring system reliability.

[0042] In some embodiments, there are multiple air distribution pipes 602 arranged at intervals along the circumference of the tower body 1. The air inlet pipe 6 is used to transport low-pressure air of 0.1 MPa to 0.2 MPa. The inner diameter of the air distribution hole 6021 is 2 mm to 6 mm, and the flow velocity of the air distribution hole 6021 is 20 m / s to 25 m / s.

[0043] Multiple air distribution ducts 602 are arranged at intervals along the circumference of the tower body 1. This arrangement ensures uniform air distribution within the carbon capture section 102, facilitating thorough mixing of the quicklime water. The air inlet duct 6 delivers low-pressure air at 0.1 MPa to 0.2 MPa. The inner diameter of the air distribution orifice 6021 is 2 mm to 6 mm, and the flow velocity at the orifice 6021 is 20 m / s to 25 m / s. These parameters are selected to ensure effective mixing of the quicklime water while avoiding excessive pressure and flow velocity that could lead to system instability or damage.

[0044] Therefore, multiple air distribution ducts 602 are arranged at intervals along the circumference of the tower body, ensuring uniform air distribution within the carbon capture section 102. This facilitates thorough mixing of the quicklime water, preventing the accumulation and clumping of precipitates. Uniform air mixing promotes sufficient contact and reaction between carbon dioxide and quicklime water, forming calcium carbonate precipitate, thereby improving carbon capture efficiency. Appropriate air pressure and flow rate help maintain the uniformity and reactivity of the quicklime water, optimizing the conditions for the carbon capture reaction. Effective mixing helps prevent precipitates within the carbon capture section 102 from clogging pipes and equipment, ensuring stable system operation. By optimizing the carbon capture reaction, the amount of quicklime water used can be reduced, thus lowering energy consumption. The arrangement of multiple air distribution ducts 602 increases system redundancy; even if some air distribution holes 6021 become blocked, others can still continue to operate, ensuring system reliability.

[0045] In some embodiments, the carbamate pyrolysis coupled carbon capture device further includes a storage tank 7, and the carbon capture section 102 has a discharge port 1021, which is connected to the storage tank 7. The discharge port 1021 is used to discharge quicklime water and calcium carbonate precipitate in the carbon capture section 102 into the storage tank 7. The storage tank 7 is connected to the water inlet pipe 3 via a delivery pump to transport the quicklime water in the storage tank 7 to the water inlet pipe 3.

[0046] like Figure 1 As shown, the carbon capture section 102 has a discharge port 1021 for discharging quicklime water and calcium carbonate precipitate from the carbon capture section 102 into the storage tank 7. The discharge port 1021 is connected to the storage tank 7 to ensure the smooth discharge and storage of the precipitate. The storage tank 7 is connected to the water inlet pipe 3 via a transfer pump, which is used to transport the quicklime water in the storage tank 7 to the water inlet pipe 3, realizing the recycling of the quicklime water.

[0047] Therefore, the outlet 1021 facilitates the efficient collection and discharge of quicklime water and calcium carbonate precipitate within the carbon capture section 102, reducing the accumulation of precipitates and the risk of blockage. The connection between the storage tank 7 and the inlet pipe 3, through the action of the conveying pump, enables the recycling of quicklime water, improving resource utilization efficiency and reducing the consumption of fresh quicklime water. Recycling quicklime water helps maintain the stability of reaction conditions and improves the efficiency of the carbon capture reaction. By reducing the consumption of fresh quicklime water, operating costs are lowered, and the overall system economy is improved. The storage tank 7 and the conveying pump increase system redundancy; even if some equipment fails, the system can continue to operate, ensuring system reliability. The storage tank 7 facilitates the collection and cleaning of precipitates, reducing the difficulty and frequency of maintenance.

[0048] In some embodiments, the residence time of ammonium carbamate powder in the pyrolysis section 101 is 8s to 12s, and the pyrolysis temperature in the pyrolysis section 101 is 100℃ to 120℃.

[0049] The residence time of ammonium carbamate powder in pyrolysis section 101 is 8 to 12 seconds. This time range is optimized to ensure complete pyrolysis of the ammonium carbamate powder while avoiding excessive residence time that could lead to energy waste or equipment overheating. The pyrolysis temperature in pyrolysis section 101 is 100°C to 120°C. This temperature range is chosen appropriately because it is sufficient to decompose ammonium carbamate into ammonia and carbon dioxide, but not so high as to damage the equipment or cause unnecessary safety risks.

[0050] With optimized residence time and temperature, ammonium carbamate powder can be effectively pyrolyzed to produce ammonia and carbon dioxide, thereby improving pyrolysis efficiency. Appropriate pyrolysis temperature and residence time help ensure the safe conduct of the pyrolysis process, avoiding equipment damage or uncontrolled chemical reactions that may be caused by high temperatures. Optimizing residence time and temperature can reduce unnecessary energy consumption, thus lowering the overall system operating costs. Ensuring complete pyrolysis of ammonium carbamate powder helps improve resource utilization efficiency and reduce waste.

[0051] Specifically, in this embodiment of the invention, the tower body 1 adopts a circular cross-section structure, with the ratio of its height to the diameter of the circular cross-section controlled at (1.8~2.2):1.0. The ratio of the height to the diameter of the circular cross-section of the pyrolysis section 101 is controlled at (0.8~1.0):1.0. Four feed pipes 2 are provided, with the diameter of the feed pipes 2 being 1 / 15~1 / 12 of the diameter of the tower body 1. The diameter of the water inlet pipe 3 is 1 / 10~1 / 8 of the diameter of the tower body 1. The length of the feed pipes 2 extending into the pyrolysis section 101 is 1 / 6~1 / 5 of the diameter of the circular cross-section of the tower body 1. The atomization layer is provided in 3~4 stages, with 6~8 atomizing pipes 5 in each layer. The diameter of each atomizing pipe 5 is 1 / 20~1 / 16 of the diameter of the circular cross-section of the tower body 1. The height between two adjacent layers of atomizing pipes 5 is 1 / 4~1 / 3 of the height of the pyrolysis section 101. The ratio of the height of the carbon capture section 102 to the diameter of the circular cross-section of the tower body 1 is controlled at (1.0~1.2):1.0.

[0052] 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.

[0053] 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.

[0054] 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.

[0055] 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.

[0056] 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.

[0057] 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 carbamate pyrolysis coupled carbon capture device, characterized in that, include: The tower body includes a pyrolysis section and a carbon capture section arranged in a top-to-bottom direction; The tower includes a feed pipe and a water inlet pipe, both of which are installed along the tower body. The feed pipe is used to transport the mixture of ammonium carbamate powder and quicklime into the pyrolysis section, and the water inlet pipe is used to transport slaked lime water into the pyrolysis section. The slaked lime water and quicklime react in the pyrolysis section to produce pyrolysis gas containing carbon dioxide and ammonia by pyrolysis of ammonium carbamate powder. The reacted slaked lime water and pyrolysis gas enter the carbon capture section. In the carbon capture section, the carbon dioxide in the pyrolysis gas reacts with the slaked lime water to form calcium carbonate precipitate. An exhaust pipe is provided in the tower body. The first end of the exhaust pipe is located below the liquid surface of the quicklime water in the carbon capture section, and the second end of the exhaust pipe is located outside the tower body. The exhaust pipe is used to discharge the pyrolysis gas after carbon capture.

2. The carbamate ammonia pyrolysis coupled carbon capture device according to claim 1, characterized in that, Both the feed pipe and the water inlet pipe are arranged vertically. The water inlet pipe is coaxial with the tower body. There are multiple feed pipes arranged at intervals along the circumference of the water inlet pipe.

3. The carbamate ammonia pyrolysis coupled carbon capture device according to claim 1, characterized in that, The carbamate pyrolysis coupled carbon capture device further includes an atomizing tube, which is located in the pyrolysis section and connected to the water inlet pipe. The atomizing tube is perpendicular to the water inlet pipe and has a plurality of atomizing holes arranged at intervals.

4. The carbamate ammonia pyrolysis coupled carbon capture device according to claim 3, characterized in that, The axis of the atomizing hole forms an angle of 30° to 45° with the vertical direction and is set obliquely downward. The inner diameter of the atomizing hole is 2mm to 5mm, and the flow velocity of the atomizing hole is 15m / s to 25m / s.

5. The carbamate ammonia pyrolysis coupled carbon capture device according to claim 3, characterized in that, The number of atomizing tubes is multiple, and the multiple atomizing tubes are divided into multiple atomizing layers. The multiple atomizing layers are arranged at intervals along the height direction of the tower body, and each atomizing layer includes multiple atomizing tubes arranged at intervals along the circumference of the water inlet pipe.

6. The carbamate ammonia pyrolysis coupled carbon capture device according to claim 5, characterized in that, The included angle between two adjacent atomizing tubes in the atomizing layer is 45° to 60°.

7. The carbamate ammonia pyrolysis coupled carbon capture device according to claim 1, characterized in that, The carbamate pyrolysis coupled carbon capture device further includes an air inlet pipe, which includes a main pipe and an air distribution pipe. The main pipe is located in the tower body, with its first end inside the carbon capture section and its second end outside the tower body. The air distribution pipe is located inside the carbon capture section and below the liquid surface of the quicklime water. The air distribution pipe has multiple spaced air distribution holes. The air inlet pipe supplies air to the carbon capture section to stir the quicklime water.

8. The carbamate ammonia pyrolysis coupled carbon capture device according to claim 7, characterized in that, The number of air distribution pipes is multiple and they are arranged at intervals along the circumference of the tower body. The air inlet pipe is used to transport low-pressure air of 0.1Mpa~0.2Mpa. The inner diameter of the air distribution hole is 2mm~6mm and the flow velocity of the air distribution hole is 20m / s~25m / s.

9. The carbamate ammonia pyrolysis coupled carbon capture device according to claim 1, characterized in that, The carbamate ammonia pyrolysis coupled carbon capture device further includes a storage tank. The carbon capture section has a discharge port, which is connected to the storage tank. The discharge port is used to discharge quicklime water and calcium carbonate precipitate in the carbon capture section into the storage tank. The storage tank is connected to the water inlet pipe through a conveying pump to transport the quicklime water in the storage tank to the water inlet pipe.

10. The carbamate ammonia pyrolysis coupled carbon capture device according to claim 1, characterized in that, The residence time of ammonium carbamate powder in the pyrolysis section is 8s~12s, and the pyrolysis temperature in the pyrolysis section is 100℃~120℃.

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