Selective catalytic denitration pyrolysis device coupled with carbon capture

Abstract

The invention discloses a coupling carbon capture selective catalytic denitration pyrolysis device which comprises a shell, a pyrolysis cylinder, a carbon capture cylinder and a heating cylinder, the shell is a rectangular shell, the top of the shell is provided with a separation cavity, the bottom of the shell is provided with a gas collection cavity, and the gas collection cavity is communicated with the pyrolysis cylinder. The first end of the pyrolysis cylinder extends into the shell from the top of the shell and communicates with the gas collection cavity, the pyrolysis cylinder is arranged at the center of the shell, and the pyrolysis cylinder is used for pyrolyzing ammonium carbamate powder and conveying pyrolysis gas of carbon dioxide and ammonia gas generated by pyrolysis into the gas collection cavity; the slaked lime water inlet is used for conveying raw and cooked lime water into the carbon capture cylinder so as to adsorb carbon dioxide in pyrolysis gas entering the carbon capture cylinder from the gas collection cavity. Compared with urea ammonia preparation, the ammonia preparation efficiency is improved by 5.4%-24.8% and averagely improved by 15.60%, the ammonia preparation energy consumption is reduced by 30.6%-40.6%, and meanwhile, the denitration efficiency of the generated mixed gas entering the flue gas selective catalytic denitration reactor can be improved by 2.8%-4.2%.

Description

Technical Field

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

[0002] In the SCR flue gas denitrification process, the choice of reducing agent is crucial. Currently, urea is the most commonly used reducing agent for flue gas denitrification. 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] 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 propose a selective catalytic denitrification pyrolysis device coupled with carbon capture.

[0006] The selective catalytic denitrification pyrolysis device with coupled carbon capture according to an embodiment of the present invention includes a shell, a pyrolysis cylinder, a carbon capture cylinder, and a heating cylinder. The shell is rectangular, with a separation chamber at the top and a gas collection chamber at the bottom. The shell has a quicklime water inlet and a mixed gas outlet communicating with the separation chamber, and also has a quicklime water outlet and a solid outlet communicating with the gas collection chamber. The first end of the pyrolysis cylinder extends into the shell from the top and communicates with the gas collection chamber, and the second end of the pyrolysis cylinder has a discharge port. The pyrolysis cylinder is located at the center of the shell. The pyrolysis process involves pyrolyzing ammonium carbamate powder and conveying the generated carbon dioxide and ammonia gas to the gas collection chamber. A carbon trap is located within the shell at its four corners. The top and bottom of the carbon trap are connected to the separation chamber and the gas collection chamber, respectively. A quicklime water inlet is used to supply quicklime water into the carbon trap to adsorb carbon dioxide from the pyrolysis gas entering the carbon trap from the gas collection chamber. The adsorbed pyrolysis gas is discharged through the mixed gas outlet. A heating cylinder is located within the shell between two adjacent carbon traps and is used to heat the pyrolysis cylinder for pyrolysis.

[0007] In some embodiments, the pyrolysis cylinder, the carbon trapping cylinder, and the heating cylinder are all square with equal side lengths, and the pyrolysis cylinder, the carbon trapping cylinder, and the heating cylinder are arranged in a matrix.

[0008] In some embodiments, the ratio of the height of the housing to the side length of the square cross-section is (5.0-6.0):1.0.

[0009] In some embodiments, the pyrolysis cylinder and the carbon collection cylinder have the same height, and the height ratio of the pyrolysis cylinder to the separation chamber and the gas collection chamber is (5.0-6.0):1.0:(1.5-2.0).

[0010] In some embodiments, the contact and separation time between the pyrolysis gas and the adsorbed quicklime aqueous solution in the gas collecting chamber is 3s-5s.

[0011] In some embodiments, the residence time of the pyrolysis gas in the carbon trap is 5s-12s.

[0012] In some embodiments, the residence time of ammonium carbamate powder in the pyrolysis cylinder is 8s-10s.

[0013] In some embodiments, the selective catalytic denitrification pyrolysis device for coupled carbon capture of the present invention further includes a heating rod and a heat storage body. The heating rod is disposed inside the heating cylinder and is coaxially arranged with the heating cylinder. An annular cavity is defined between the heating rod and the heating cylinder, and the heat storage body is filled in the annular cavity.

[0014] In some embodiments, the quicklime water outlet is connected to the quicklime water inlet via a circulation pump.

[0015] In some embodiments, the selective catalytic denitrification pyrolysis apparatus for coupled carbon capture according to the present invention further includes an isolation plate disposed at the bottom end port of the heating cylinder.

[0016] The selective catalytic denitrification pyrolysis device with coupled carbon capture according to embodiments of the present invention has the following advantages: First, it couples the pyrolysis of ammonium carbamate with the carbon capture process within the same device, achieving carbon dioxide removal at the source and avoiding competitive adsorption of carbon dioxide into the SCR system and reactants on the catalyst surface, thereby significantly improving denitrification efficiency, especially under high carbon dioxide concentration conditions. Second, it uses lower-cost ammonium carbamate as the main denitrification agent precursor, replacing traditional urea, effectively reducing the raw material cost of the reducing agent. Third, by integrating a heating cylinder inside the device and utilizing the layout of the carbon capture cylinder to surround and heat the pyrolysis cylinder, it achieves efficient and concentrated heat transfer, reducing energy consumption in the pyrolysis process compared to traditional external heating methods. Fourth, the device captures carbon dioxide through a liquid-solid chemical reaction and periodically discharges the generated solid precipitate, effectively alleviating the problem of ammonium carbamate powder easily agglomerating and clogging pipes from a structural design perspective, ensuring the continuity and stability of system operation, and achieving a balance between denitrification, energy saving, and cost reduction.

[0017] Compared with urea-to-ammonia production, the present invention improves ammonia production efficiency by 5.4% to 24.8%, with an average improvement of 15.60%, and reduces ammonia production energy consumption by 30.6% 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 2.8% to 4.2%. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the selective catalytic denitrification pyrolysis device with coupled carbon capture according to an embodiment of the present invention.

[0019] Figure 2 This is a cross-sectional view of the selective catalytic denitrification pyrolysis device with coupled carbon capture according to an embodiment of the present invention.

[0020] Figure 3 This is a cross-sectional view of the selective catalytic denitrification pyrolysis device with coupled carbon capture according to an embodiment of the present invention.

[0021] 1. Shell; 101. Separation chamber; 102. Gas collection chamber; 103. Quicklime water inlet; 104. Mixed gas outlet; 105. Quicklime water outlet; 106. Solid outlet; 2. Pyrolysis cylinder; 201. Feed port; 3. Carbon collection cylinder; 4. Heating cylinder; 5. Heating rod; 6. Heat storage body; 8. Isolation plate. 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 3As shown, the selective catalytic denitrification pyrolysis device with coupled carbon capture according to an embodiment of the present invention includes a shell 1, a pyrolysis cylinder 2, a carbon capture cylinder 3, and a heating cylinder 4. The shell 1 is a rectangular shell 1, with a separation chamber 101 at the top and a gas collection chamber 102 at the bottom. The shell 1 has a quicklime water inlet 103 and a mixed gas outlet 104 communicating with the separation chamber 101. The shell 1 also has a quicklime water outlet 105 and a solid outlet 106 communicating with the gas collection chamber 102.

[0024] The first end of the pyrolysis cylinder 2 extends into the housing 1 from the top and communicates with the gas collecting chamber 102. The second end of the pyrolysis cylinder 2 has a discharge port 201. The pyrolysis cylinder 2 is located at the center of the housing 1. The pyrolysis cylinder 2 is used to pyrolyze ammonium carbamate powder and transport the pyrolysis gas generated by pyrolysis, carbon dioxide and ammonia, to the gas collecting chamber 102.

[0025] The carbon trapping cylinder 3 is located inside the shell 1 at its four corners. The top and bottom of the carbon trapping cylinder 3 are connected to the separation chamber 101 and the gas collecting chamber 102, respectively. The quicklime water inlet 103 is used to supply quicklime water into the carbon trapping cylinder 3 to adsorb carbon dioxide from the pyrolysis gas entering the carbon trapping cylinder 3 from the gas collecting chamber 102. The adsorbed pyrolysis gas is discharged through the mixed gas outlet 104. The heating cylinder 4 is located inside the shell 1 between two adjacent carbon trapping cylinders 3 and is used to heat the pyrolysis cylinder 2 for pyrolysis.

[0026] In the selective catalytic denitrification pyrolysis device with coupled carbon capture according to this embodiment of the invention, ammonium carbamate powder, as a denitrification agent precursor, is first fed into the device through the feed port 201 at the top of the pyrolysis cylinder 2. The heating cylinder 4 inside the device uniformly heats the pyrolysis cylinder 2 at its center, providing the necessary high-temperature environment for the thermal decomposition of ammonium carbamate. During this process, ammonium carbamate decomposes thermally, generating a mixed pyrolysis gas containing ammonia and carbon dioxide. This pyrolysis gas flows downwards and enters the gas collection chamber 102 at the bottom of the shell 1. Simultaneously, quicklime water (calcium hydroxide solution) is pumped into the carbon capture cylinders 3 located at the four corners of the shell 1 through the quicklime water inlet 103 at the top of the shell 1, and flows downwards under gravity. The pyrolysis gas in the gas collection chamber 102 enters the carbon capture cylinder 3 from the bottom, contacting the quicklime water flowing downwards in a countercurrent manner. During this process, the quicklime reacts chemically with the carbon dioxide in the pyrolysis gas to generate calcium carbonate precipitate, thereby efficiently capturing and separating carbon dioxide from the gas phase. The clean gas, mainly composed of ammonia after decarbonization, enters the separation chamber 101 from the top of the carbon capture cylinder 3 and is finally discharged through the mixed gas outlet 104, and sent to the subsequent SCR denitrification system. The calcium carbonate precipitate generated by the reaction is finally collected in the gas collection chamber 102 with the quicklime water and discharged through the solid outlet 106, realizing the effective separation of reaction byproducts.

[0027] The selective catalytic denitrification pyrolysis device with coupled carbon capture according to embodiments of the present invention firstly couples the ammonium carbamate pyrolysis and carbon capture processes within the same device, achieving carbon dioxide removal at the source and avoiding competitive adsorption of carbon dioxide into the SCR system and reactants on the catalyst surface, thereby significantly improving denitrification efficiency, especially under high carbon dioxide concentration conditions. Secondly, it uses lower-cost ammonium carbamate as the main denitrification agent precursor, replacing traditional urea, effectively reducing the raw material cost of the reducing agent. Thirdly, by integrating a heating cylinder 4 inside the device and utilizing the layout of the carbon capture cylinder 3 to surround and heat the pyrolysis cylinder 2, efficient and concentrated heat transfer is achieved, reducing energy consumption in the pyrolysis process compared to traditional external heating methods. Fourthly, the device captures carbon dioxide through a liquid-solid chemical reaction and periodically discharges the generated solid precipitate, effectively alleviating the problem of ammonium carbamate powder easily agglomerating and clogging pipes from a structural design perspective, ensuring the continuity and stability of system operation, and achieving a balance between denitrification, energy saving, and cost reduction.

[0028] Compared with urea-to-ammonia production, the present invention improves ammonia production efficiency by 5.4% to 24.8%, with an average improvement of 15.60%, and reduces ammonia production energy consumption by 30.6% 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 2.8% to 4.2%.

[0029] In some embodiments, the pyrolysis cylinder 2, the carbon trapping cylinder 3, and the heating cylinder 4 are all square with equal side lengths, and are arranged in a matrix.

[0030] like Figure 2 As shown, the pyrolysis cylinder 2, carbon capture cylinder 3, and heating cylinder 4 are designed as squares with equal sides, arranged in a matrix. This highly modular and standardized matrix layout allows the heating cylinder 4 to conduct heat to the adjacent pyrolysis cylinder 2 in the shortest distance and in the most uniform manner. Each pyrolysis cylinder 2 is surrounded by multiple heating cylinders 4, forming a stable and symmetrical heating field. This ensures that the ammonium carbamate powder inside the cylinder is heated uniformly, thereby achieving efficient and complete thermal decomposition and avoiding uneven decomposition or energy waste caused by local overheating or insufficient heating. At the same time, the uniform distribution of the carbon capture cylinders 3 in the matrix ensures that the pyrolysis gas flow rising from the gas collection chamber 102 can be evenly distributed into each capture cylinder, ensuring full contact with the quicklime water, which greatly improves the overall carbon dioxide capture efficiency and processing capacity.

[0031] Furthermore, the close arrangement of the square cylinders minimizes the wasted space inside the unit, resulting in a more compact structure and smaller footprint for the entire denitrification pyrolysis unit, facilitating installation and retrofitting within existing plant sites. In addition, the highly standardized design simplifies manufacturing, installation, and maintenance processes. All core cylinders use uniform specifications, facilitating mass production, reducing manufacturing costs, and ensuring high component interchangeability during replacement or maintenance, significantly shortening maintenance cycles and lowering operating costs. This modular structure provides great flexibility for unit expansion; the system scale can be easily adjusted by adding or removing matrix units according to actual flue gas treatment needs, enabling on-demand configuration and investment, demonstrating excellent economic efficiency and engineering application value.

[0032] In some embodiments, the ratio of the height of the shell 1 to the side length of the square cross-section is (5.0-6.0):1.0. The sufficiently large height of the shell 1 provides ample reaction space and residence time for key processes such as pyrolysis, gas flow conduction, and carbon capture. Specifically, the longer vertical space ensures that the pyrolysis cylinder 2 has sufficient length to accommodate the heating zone, allowing the ammonium carbamate powder to undergo continuous and sufficient heating during its descent, ensuring its complete decomposition. Simultaneously, for the carbon capture process, this height creates a longer reaction path for the countercurrent contact between the quicklime water and the pyrolysis gas within the carbon capture cylinder 3. This not only prolongs the reaction time between the gas and liquid phases, bringing the carbon dioxide adsorption reaction closer to chemical equilibrium, but also enhances gas-liquid disturbance and improves mass transfer efficiency, thereby ensuring deep removal of carbon dioxide.

[0033] In addition, this ratio helps maintain a stable three-phase flow state of gas, liquid, and solid. Sufficient height can effectively buffer the impact of pyrolysis gas flow, making the gas velocity distribution more uniform and preventing liquid entrainment or gas path short-circuiting caused by excessively fast gas flow, thus ensuring the stability and reliability of the carbon capture process.

[0034] In some embodiments, the pyrolysis cylinder 2 and the carbon collection cylinder 3 have the same height, and the height ratio of them to the separation chamber 101 and the gas collection chamber 102 is (5.0-6.0):1.0:(1.5-2.0).

[0035] The heights of the pyrolysis cylinder 2 and the carbon trapping cylinder 3 are set to be the same, and their height ratio with that of the separation chamber 101 and the gas collecting chamber 102 is controlled within the range of (5.0-6.0):1.0:(1.5-2.0). The pyrolysis cylinder 2 and the carbon trapping cylinder 3 occupy the main height of the device, providing a sufficiently long reaction time and path for the complete thermal decomposition of ammonium carbamate and the efficient capture of carbon dioxide. The gas collecting chamber 102, located below the main reaction zone, plays a crucial role in buffering and equalizing pressure. It can uniformly collect the pyrolysis gas discharged from the pyrolysis cylinder 2 and stably distribute it to the surrounding carbon trapping cylinders 3, avoiding uneven distribution of airflow among the cylinders. The separation chamber 101, located above the main reaction zone, provides an effective collection space for the clean ammonia gas after decarbonization. By utilizing the sudden increase in the cross-sectional area of ​​the space, the airflow velocity is reduced, which is conducive to the sedimentation and separation of any small droplets or solid particles that may be entrained due to gravity, thereby ensuring the purity of the gas discharged from the mixed gas outlet 104.

[0036] In some embodiments, the contact separation time between the pyrolysis gas and the adsorbed quicklime aqueous solution in the gas collecting chamber 102 is 3s-5s.

[0037] The contact and separation time between the pyrolysis gas and the adsorbed quicklime solution in the gas collecting chamber 102 is controlled within 3 to 5 seconds. When the pyrolysis gas containing carbon dioxide enters the bottom gas collecting chamber 102, it will first undergo pre-contact with the partially saturated quicklime solution collected there. This 3 to 5-second time window provides a brief initial reaction and buffering opportunity for the gas and liquid phases. During this period, some carbon dioxide can still react with the remaining calcium hydroxide in the solution. At the same time, this buffering process can stabilize the pressure and velocity of the gas flow, allowing it to enter each carbon capture cylinder 3 more evenly during the subsequent ascent. This creates favorable conditions for the efficient countercurrent main reaction in the carbon capture cylinder 3, significantly improving the overall carbon dioxide capture efficiency.

[0038] By adding this "pretreatment" step to the gas collection chamber 102, "cascaded capture" of carbon dioxide is achieved. This means that an additional portion of carbon dioxide is captured outside the main capture zone (carbon capture cylinder 3), thereby reducing the gas load entering the main capture zone and making the decarbonization of the entire system more thorough. Secondly, it enhances the stability and reliability of the system operation. The 3-5 second contact time is sufficient to effectively buffer the high-temperature pulsed airflow from the pyrolysis cylinder 2, avoiding the impact of drastic airflow fluctuations on the stability of the liquid film in the subsequent carbon capture cylinder 3. This prevents liquid entrainment or channeling caused by excessive airflow disturbance, ensuring the continuous and stable operation of the entire denitrification agent preparation process, and ultimately providing the downstream SCR system with ammonia gas of more stable flow rate and concentration.

[0039] In some embodiments, the residence time of the pyrolysis gas in the carbon trap 3 is 5s-12s.

[0040] The residence time of the pyrolysis gas in the carbon trap 3 is controlled between 5 and 12 seconds. This time range provides the necessary guarantee for the completion of the complex chemical reaction between carbon dioxide and quicklime water (calcium hydroxide solution). When the pyrolysis gas enters the carbon trap 3, it forms a countercurrent contact with the downward-flowing quicklime water. Carbon dioxide molecules need to diffuse from the bulk gas phase to the surface of the liquid phase, dissolve, and react with hydroxide ions to ultimately form calcium carbonate precipitate. This series of mass transfer and reaction processes requires a certain amount of time to complete. The residence time of 5 to 12 seconds ensures that the vast majority of carbon dioxide molecules have sufficient opportunity to participate in and complete this series of steps, thereby achieving deep removal and reducing the carbon dioxide concentration in the gas discharged from the top of the carbon trap 3 to an extremely low level.

[0041] In some embodiments, the residence time of ammonium carbamate powder in the pyrolysis cylinder 2 is 8s-10s.

[0042] The residence time of ammonium carbamate powder in the pyrolysis cylinder 2 is controlled to be between 8 and 10 seconds. The thermal decomposition of ammonium carbamate is not instantaneous, but an endothermic process that requires sufficient heat energy to overcome the reaction energy barrier. This 8-10 second residence time ensures that the powder receives continuous and sufficient heat transfer as it falls under gravity through the pyrolysis cylinder 2 surrounded by the heating cylinder 4. This time is sufficient for the powder to rise from its initial temperature to the pyrolysis temperature and ensures complete internal decomposition, thereby maximizing the generation of ammonia gas. This avoids raw material waste and intermediate product blockage caused by incomplete decomposition, ensuring the yield and purity of the target product in the pyrolysis gas.

[0043] First, it achieves the optimal balance between reaction completeness and energy consumption. Too short a reaction time leads to incomplete pyrolysis, reducing ammonia generation efficiency, and unreacted solids may enter the system causing blockages. Too long a reaction time increases unnecessary heating energy consumption and equipment height, raising operating and investment costs. The 8-10 second setting finds the optimal solution for energy utilization efficiency while ensuring a decomposition rate of over 99%. Second, this precise control effectively improves the system's stability and reliability. By ensuring the complete decomposition of ammonium carbamate, it fundamentally eliminates the risk of secondary decomposition and agglomeration in pipelines or downstream equipment caused by raw material residues. This ensures the continuous and stable operation of the entire denitrification agent preparation unit, ultimately providing a highly stable ammonia source in terms of flow rate and composition for the downstream SCR denitrification system, a crucial guarantee for the efficient and reliable operation of the entire denitrification process.

[0044] In some embodiments, the selective catalytic denitrification pyrolysis device for coupled carbon capture of the present invention further includes a heating rod 5 and a heat storage body 6. The heating rod 5 is disposed inside the heating cylinder 4 and is coaxially arranged with the heating cylinder 4. An annular cavity is defined between the heating rod 5 and the heating cylinder 4, and the heat storage body 6 is filled in the annular cavity.

[0045] like Figure 2 and Figure 3 As shown, heating rod 5 serves as the core heat source, directly converting electrical or thermal energy into high temperature. Heat is transferred to the tightly surrounding heat storage body 6 via thermal conduction and radiation. The material of heat storage body 6 (such as ceramic or metal alloy) has a high specific heat capacity, enabling it to quickly absorb and store heat, becoming a stable thermal buffer. Subsequently, heat storage body 6, through its large surface area, uniformly and continuously transfers heat to the wall of heating cylinder 4 in contact with it via thermal radiation and convection, thereby heating the central pyrolysis cylinder 2. This three-stage heat transfer mode of "heat source-heat storage-heat exchange" makes the heating of the pyrolysis cylinder 2 more stable and controllable, avoiding localized overheating or temperature fluctuations caused by direct power supply to heating rod 5.

[0046] The heat storage body 6 can store the heat generated by the heating rod 5 during off-peak periods or when there is excess energy supply, and release it slowly when needed, achieving energy "peak shaving and valley filling," reducing unnecessary energy consumption, lowering operating costs, and significantly enhancing the system's temperature control accuracy and operational stability. The presence of the heat storage body 6 acts like a "thermal inertia flywheel," effectively mitigating temperature shocks caused by the start-up, shutdown, or power adjustment of the heating rod 5. This ensures that the temperature field within the pyrolysis cylinder 2 remains within the narrow window required for the efficient decomposition of ammonium carbamate, which is crucial for ensuring the quality of pyrolysis products and reducing side reactions. Furthermore, this structure extends the service life of key components. With the heat storage body 6 acting as an intermediary, the heating rod 5 does not directly bear severe thermal shocks, and the heating cylinder 4 is heated more uniformly. This reduces the risk of thermal stress fatigue in materials, thereby extending the service life of the entire heating system, reducing the frequency of equipment maintenance and replacement, and further improving the economy and reliability of the device.

[0047] In some embodiments, the quicklime water outlet 105 is connected to the quicklime water inlet 103 via a circulation pump.

[0048] Although the calcium hydroxide concentration in the quicklime solution flowing from the bottom of carbon capture cylinder 3 is reduced due to the adsorption of carbon dioxide, a large amount of unreacted calcium hydroxide still remains. This solution is repressurized by a circulation pump and reintroduced into carbon capture cylinder 3 through the top inlet, where it comes into countercurrent contact with the newly generated pyrolysis gas. This circulation process continues, and only when the calcium hydroxide concentration in the solution drops to a preset threshold is a portion of the waste liquid discharged from the system and fresh quicklime solution added, thus maximizing chemical utilization while ensuring capture efficiency.

[0049] By recycling most of the quicklime solution, the consumption of fresh chemicals and the amount of waste liquid treated are significantly reduced, saving on raw material procurement and environmental disposal costs, thus greatly improving the economic efficiency of the entire denitrification agent preparation process. The stable pressure and flow rate provided by the circulating pump ensure that there is always a sufficient and appropriately velocity liquid phase in the carbon capture cylinder 3, maintaining a highly efficient and stable gas-liquid mass transfer environment and avoiding fluctuations in capture efficiency due to interruption of liquid supply or unstable flow rate, providing a continuous and clean ammonia source for the downstream SCR system.

[0050] In some embodiments, the selective catalytic denitrification pyrolysis device for coupled carbon capture according to the present invention further includes a partition plate 8, which is disposed at the bottom end port of the heating cylinder 4.

[0051] like Figure 3 As shown, the isolation plate 8 plays a crucial role in physical separation and gas guidance. The heating cylinder 4, as an independent heating unit, contains key electrical components such as the heating rod 5 and the heat storage body 6. The isolation plate 8, located at the bottom, completely isolates the internal space of the heating cylinder 4 from the space of the bottom gas collecting chamber 102. In this way, when the device is operating, the gas flow environment formed by pyrolysis gas in the gas collecting chamber 102 (containing ammonia, carbon dioxide, water vapor, etc.) will not directly intrude into the interior of the heating cylinder 4, thus protecting the heating elements from corrosive gases and airflow disturbances. Simultaneously, this design ensures that the pyrolysis gas discharged from the pyrolysis cylinder 2 can be completely guided to the gas collecting chamber 102, and then enters the carbon trapping cylinder 3 upwards according to the designed path. This avoids the possibility of some gas leaking into the heating cylinder 4 from the bottom due to pressure difference or turbulence, ensuring the uniqueness and controllability of the material flow direction.

[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 selective catalytic denitrification pyrolysis device coupled with carbon capture, characterized in that, include: The housing is rectangular, with a separation chamber at the top and a gas collection chamber at the bottom. The housing has a quicklime water inlet and a mixed gas outlet communicating with the separation chamber, and also has a quicklime water outlet and a solid outlet communicating with the gas collection chamber. A pyrolysis cylinder, the first end of which extends into the housing from the top of the housing and communicates with the gas collection chamber, the second end of which has a discharge port, the pyrolysis cylinder being located at the center of the housing, the pyrolysis cylinder being used to pyrolyze ammonium carbamate powder and to transport the pyrolysis gases of carbon dioxide and ammonia generated by pyrolysis to the gas collection chamber; A carbon trap is disposed inside the shell and located at the four corners of the shell. The top and bottom ends of the carbon trap are respectively connected to the separation chamber and the gas collection chamber. The quicklime water inlet is used to deliver quicklime water into the carbon trap to adsorb carbon dioxide in the pyrolysis gas entering the carbon trap from the gas collection chamber. The adsorbed pyrolysis gas is discharged through the mixed gas outlet. A heating cylinder is disposed inside the shell and located between two adjacent carbon collection cylinders, and is used to heat the pyrolysis cylinder for pyrolysis.

2. The selective catalytic denitrification pyrolysis device coupled with carbon capture according to claim 1, characterized in that, The pyrolysis cylinder, the carbon trapping cylinder, and the heating cylinder are all square with equal side lengths, and are arranged in a matrix.

3. The selective catalytic denitrification pyrolysis device coupled with carbon capture according to claim 2, characterized in that, The ratio of the height of the shell to the side length of the square cross-section is (5.0-6.0):1.

0.

4. The selective catalytic denitrification pyrolysis device coupled with carbon capture according to claim 1, characterized in that, The pyrolysis cylinder and the carbon collection cylinder have the same height, and the height ratio of the pyrolysis cylinder to the separation chamber and the gas collection chamber is (5.0-6.0):1.0:(1.5-2.0).

5. The selective catalytic denitrification pyrolysis apparatus coupled with carbon capture according to claim 1, characterized in that, The contact and separation time between the pyrolysis gas and the adsorbed quicklime aqueous solution in the gas collecting chamber is 3s-5s.

6. The selective catalytic denitrification pyrolysis apparatus coupled with carbon capture according to claim 1, characterized in that, The residence time of the pyrolysis gas in the carbon trap is 5s-12s.

7. The selective catalytic denitrification pyrolysis apparatus coupled with carbon capture according to claim 1, characterized in that, The residence time of ammonium carbamate powder in the pyrolysis cylinder is 8s-10s.

8. The selective catalytic denitrification pyrolysis apparatus coupled with carbon capture according to claim 1, characterized in that, It also includes a heating rod and a heat storage body. The heating rod is disposed inside the heating cylinder and is coaxially arranged with the heating cylinder. An annular cavity is defined between the heating rod and the heating cylinder, and the heat storage body is filled in the annular cavity.

9. The selective catalytic denitrification pyrolysis apparatus coupled with carbon capture according to claim 1, characterized in that, The quicklime water outlet is connected to the quicklime water inlet via a circulating pump.

10. The selective catalytic denitrification pyrolysis apparatus coupled with carbon capture according to claim 1, characterized in that, It also includes an isolation plate, which is located at the bottom end port of the heating cylinder.

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