A two-stage rotary adsorption carbon capture device and method

Abstract

The application discloses a kind of two-stage runner adsorption carbon capture device and method, including first stage runner and second stage runner first stage runner is divided into heat absorption zone and heat release zone along its rotation direction, and second stage runner is divided into adsorption zone and desorption zone along its rotation direction;The outlet side of heat absorption zone is connected to adsorption zone, and the inlet side of heat absorption zone is connected to original flue gas, and heat absorption zone is used to absorb heat when original flue gas passes, to reduce flue gas temperature and stabilize flue gas temperature in set range;The outlet side of heat release zone is connected to desorption zone, and the inlet side of heat release zone is connected to mixed regeneration gas for desorption, and heat release zone is used to release heat when mixed regeneration gas passes, to increase the temperature of desorption mixed gas.Heat absorption zone outlet connects adsorption zone, heat release zone outlet connects desorption zone, utilizes heat absorption zone to original flue gas heat absorption cooling and stabilizes temperature, utilizes heat release zone to mixed regeneration gas heating and temperature rise, realizes heat recycling, reduces regeneration energy consumption.

Description

Technical Field

[0001] This invention belongs to the field of carbon dioxide capture technology, specifically relating to a two-stage rotary adsorption carbon capture device and method. Background Technology

[0002] With the acceleration of global industrialization, greenhouse gas emissions, primarily carbon dioxide (CO2), are increasing year by year. Flue gas emissions from stationary sources such as coal-fired power plants, cement plants, and steel mills are among the main sources of CO2. Therefore, developing efficient and low-energy-consumption flue gas carbon capture technologies is of great significance.

[0003] Among existing carbon capture technologies, adsorption, especially using solid amine adsorbents, has become a research hotspot due to its advantages such as low corrosivity, relatively low regeneration energy consumption, and no secondary pollution. Rotary adsorption devices, in particular, are considered a promising technological approach for industrial application due to their ability to achieve continuous adsorption and regeneration, compact structure, and low pressure drop.

[0004] However, existing technologies still have the following shortcomings: 1. In existing adsorption devices, although the flue gas undergoes pretreatment before entering the adsorption unit, its temperature may still fluctuate, and the adsorption process itself releases adsorption heat, causing the temperature of the adsorbent bed to rise and significantly reducing the CO2 adsorption capacity. Therefore, there is a problem of adsorption efficiency being affected by temperature fluctuations.

[0005] 2. In existing adsorption devices, when multi-stage adsorption is used, the gas temperature after the previous stage of treatment may not be suitable for the optimal working window of the adsorbent in the next stage, affecting the overall collection efficiency.

[0006] Therefore, how to reduce flue gas fluctuations to ensure adsorption efficiency and how to match the pre-treatment temperature with the post-adsorption temperature to improve collection efficiency are technical problems that urgently need to be solved by those skilled in the art. Summary of the Invention

[0007] The technical problem to be solved by the present invention is to address the shortcomings of the prior art by providing a method that utilizes the heat absorption zone to absorb heat from the original flue gas, cool it down and stabilize its temperature, and simultaneously ensures that the temperature of the flue gas entering the adsorption zone is stably adapted to the working window of the adsorbent. This method is used to solve the problems of flue gas temperature fluctuation, bed temperature rise caused by adsorption heat, and decrease in CO2 adsorption capacity in the prior art, as well as the problems of temperature mismatch before and after multi-stage adsorption and low collection efficiency.

[0008] The present invention adopts the following technical solution: a two-stage rotary adsorption carbon capture device, comprising a first-stage rotary wheel and a second-stage rotary wheel; The first-stage rotor is divided into an endothermic zone and an exothermic zone along its rotation direction, and the second-stage rotor is divided into an adsorption zone and a desorption zone along its rotation direction. The outlet side of the heat absorption zone is connected to the adsorption zone, and the inlet side of the heat absorption zone is connected to the original flue gas. The heat absorption zone is used to absorb heat when the original flue gas passes through, so as to reduce the flue gas temperature and stabilize the flue gas temperature within a set range. The outlet side of the heat release zone is connected to the desorption zone, and the inlet side of the heat release zone is connected to the mixed regeneration gas for desorption. The heat release zone is used to release heat when the mixed regeneration gas passes through, so as to increase the temperature of the desorbed mixed gas.

[0009] Preferably, the first rotor is divided into a sensible heat section and a phase change section along its axial direction, and the phase change section is loaded with a phase change material; The flue gas flow direction in the heat absorption zone is from the sensible heat section to the phase change section. The original flue gas passes through the sensible heat section and exchanges heat with the rotor base of the first-stage rotor to achieve a cooling. The flue gas passes through the phase change section, where the phase change material absorbs heat from the flue gas and melts, allowing the flue gas to be cooled a second time to the set range.

[0010] Preferably, the flue gas flow direction in the heat release zone is from the phase change section to the sensible heat section. The mixed regenerated gas passes through the phase change section, and the phase change material solidifies and releases heat, thus performing a primary heating. The mixed regenerated gas passes through the sensible heat section, absorbs the sensible heat of the first-stage rotor base, and undergoes secondary heating.

[0011] Preferably, the phase change material has a melting point of 75-85℃ and a latent heat of phase change of ≥180 kJ / kg.

[0012] Preferably, the phase change material is one of paraffin-based, hydrated salt, or fatty acid-based materials.

[0013] Preferably, it also includes a mixer and a fresh replenishment gas module. The outlet side of the desorption zone is provided with a recirculation gas branch and a product gas branch. The inlet side of the mixer is connected to the fresh replenishment gas module and the recirculation gas branch to provide mixed regeneration gas. The outlet side of the mixer is used to connect to the exothermic zone.

[0014] Preferably, it also includes a heat exchange module, wherein the product gas branch is connected to the outlet of the mixer via the heat exchange module, and the flue gas of the product gas branch is used to heat the mixed regenerated gas through the heat exchange module.

[0015] Preferably, an auxiliary heater is provided between the outlet side of the heat release zone and the desorption zone.

[0016] Preferably, the second-stage rotor is further provided with a cooling zone. The second-stage rotor is arranged in sequence as an adsorption zone, a desorption zone, and a cooling zone along its rotation direction. A cooling gas circuit is provided between the gas outlet side of the adsorption zone and the cooling zone.

[0017] Another technical solution of the present invention is a two-stage rotary adsorption carbon capture method, comprising: The raw flue gas passes through the heat absorption zone of the first-stage rotor, where the heat absorption zone absorbs heat from the raw flue gas and lowers its temperature to within a set range. After being cooled, the raw flue gas enters the adsorption zone of the second-stage rotor for adsorption, and the purified flue gas is discharged from the outlet of the adsorption zone. The mixed regenerated gas passes through the heat release zone of the first-stage rotor, where it releases heat to the mixed regenerated gas, raising its temperature. After being heated, the mixed regenerated gas enters the desorption zone of the second-stage rotor for CO2 desorption.

[0018] Compared with the prior art, the present invention has at least the following beneficial effects: By setting up a first-stage rotor with endothermic and exothermic zones and a second-stage rotor with adsorption and desorption zones, and connecting the outlet of the endothermic zone to the adsorption zone and the outlet of the exothermic zone to the desorption zone, the system achieves two main benefits. First, the endothermic zone absorbs heat from the original flue gas to cool it down and stabilize its temperature, solving the problems of flue gas temperature fluctuations, bed temperature rise caused by adsorption heat, and decrease in CO2 adsorption capacity in existing technologies. Second, the system ensures that the temperature of the flue gas entering the adsorption zone is stably matched to the working window of the adsorbent, solving the problems of temperature mismatch and low capture efficiency before and after multi-stage adsorption. This achieves continuous, stable, and efficient carbon capture as a whole. Third, the exothermic zone heats the mixed regeneration gas to achieve heat recovery and utilization, reducing regeneration energy consumption.

[0019] Furthermore, the first-stage rotor is axially divided into a sensible heating section and a phase change section, and the flue gas is confined to flow in the direction from the sensible heating section to the phase change section. When passing through the sensible heating section, the flue gas undergoes sensible cooling with the substrate, achieving initial temperature control. The flue gas then passes through the phase change section, where it undergoes a second, precise cooling process by absorbing heat through the melting of the phase change material. This dual cooling stabilizes the flue gas temperature within the set range, preventing temperature fluctuations from affecting the adsorption efficiency. Simultaneously, the phase change material loaded in the phase change section can store a large amount of heat, providing a stable heat source for subsequent regeneration gas heating and improving overall heat utilization.

[0020] Furthermore, the mixed regenerated gas in the exothermic zone flows from the phase change section to the sensible heat section. The mixed regenerated gas first passes through the phase change section to release latent heat through the solidification of the phase change material, achieving primary heating. Then, it passes through the sensible heat section to absorb the sensible heat of the matrix, achieving secondary heating. This forms a counter-current stepped heat exchange, making the regenerated gas heat up more fully and the temperature more uniform, significantly improving heat recovery efficiency and reducing auxiliary heating energy consumption. At the same time, the counter-current flow forms a matched heat exchange with the flue gas side, ensuring a stable and continuous heat absorption and release cycle in the first-stage rotor.

[0021] Furthermore, the phase change material has a melting point of 75–85℃ and a latent heat of phase change of ≥180kJ / kg. This melting point range ensures that the material fully melts and absorbs heat when the flue gas is cooled and fully solidifies and releases heat when the regenerated gas is heated, taking into account the stable conversion between heat absorption and heat release. The high latent heat characteristic makes the heat storage density of the material per unit mass higher, achieving greater heat throughput within a limited rotor volume, enhancing the flue gas temperature stabilization effect and the regenerated gas heating capacity, and improving the overall energy efficiency of the device.

[0022] Furthermore, by adding a mixer, a fresh replenishment gas module, and a recirculation gas branch, the gas exiting the desorption zone is split into product gas and recirculation gas. The recirculation gas is returned and mixed with the fresh replenishment gas to form regeneration gas, forming a semi-open regeneration cycle. This can not only stably provide a regeneration gas source and maintain system pressure balance, but also recover the waste heat of the desorption tail gas, reduce the amount of fresh gas used and heat loss, and reduce regeneration energy consumption.

[0023] Furthermore, a heat exchange module is added to preheat the mixed regenerated gas using the high-temperature exhaust gas from the product gas branch, thereby achieving the cascade recovery of waste heat from the desorption exhaust gas. The mixed regenerated gas is preheated before entering the first-stage rotor heat release zone, reducing the heating load of the phase change section and the sensible heat section and improving the overall heat utilization rate.

[0024] Furthermore, an auxiliary heater is installed between the outlet of the exothermic zone and the desorption zone, which can compensate for and precisely control the temperature of the mixed regenerated gas after it has been heated in the first-stage rotor exothermic zone, ensuring that the gas temperature entering the second-stage rotor desorption zone reaches the optimal desorption temperature range of the solid amine adsorbent.

[0025] Furthermore, a cooling zone is added to the second-stage rotor, and the rotor is divided into zones in the order of adsorption zone → desorption zone → cooling zone. At the same time, the purified flue gas from the adsorption zone outlet is introduced into the cooling zone through a cooling gas circuit. The low-temperature purified flue gas is used to cool the rotor after desorption, so that the rotor drops to a suitable adsorption temperature before rotating back to the adsorption zone. This avoids the high temperature after desorption from directly entering the adsorption zone, which would cause a decrease in adsorption capacity. This solves the problems of insufficient thermal coupling in the second-stage rotor and the impact of high temperature on adsorption performance, and significantly improves the continuous collection efficiency.

[0026] In summary, the two-stage rotary adsorption carbon capture device and method of the present invention, through the axial partitioning of the sensible heat section and the phase change section of the first-stage rotary adsorption carbon capture device and method, achieves dual cooling and precise temperature control of the original flue gas, solves the problem of flue gas temperature fluctuation and adsorption heat-induced decrease in adsorption efficiency, and makes the flue gas temperature match the optimal working window of the solid amine adsorbent.

[0027] By employing axial countercurrent heat exchange between flue gas and regenerated gas, and using phase change materials to achieve a closed-loop cycle of heat absorption and energy storage and heat release, the heat utilization rate is improved, the regeneration energy consumption is reduced, and the problems of large thermal inertia and heat waste in traditional rotary heating are solved.

[0028] A semi-open regeneration cycle combined with waste heat recovery via a heat exchange module enables cascaded utilization of waste heat from the desorption tail gas. An auxiliary heater provides temperature compensation, ensuring stable and controllable temperature and humidity of the mixed regeneration gas. The second-stage rotor incorporates a cooling zone and a cooling gas circuit, utilizing purified flue gas to cool the desorbed second-stage rotor, preventing the high-temperature second-stage rotor from directly entering the adsorption zone. This addresses the issue of insufficient thermal coupling in the second-stage rotor, ensuring efficient and continuous adsorption. The dual-stage rotors rotate in zones, achieving simultaneous and continuous adsorption, regeneration, and cooling operations.

[0029] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0030] To more clearly illustrate the technical solutions in the embodiments of the present invention, the accompanying drawings used in the following description of the relative embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0031] Figure 1 This is a schematic diagram of the overall structure of a two-stage rotary adsorption carbon capture device according to the present invention.

[0032] The components are as follows: 1. First-stage rotor; 11. Heat absorption zone; 12. Heat release zone; 13. Sensible heat section; 14. Phase change section; 2. Second-stage rotor; 21. Adsorption zone; 22. Desorption zone; 23. Cooling zone; 3. Circulating fan; 4. Gas-to-gas heat exchanger; 5. Auxiliary heater; 6. Cooling gas circuit; 7. Circulating gas branch; 8. Product gas branch. Detailed Implementation

[0033] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0034] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "one side," "one end," and "one side," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the invention. 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 indicated technical features. Thus, a feature defined with "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more.

[0035] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention based on the specific circumstances.

[0036] It should be understood that, when used in this specification and the appended claims, the terms "comprising" and "including" indicate the presence of the described features, integrals, steps, operations, elements and / or components, but do not exclude the presence or addition of one or more other features, integrals, steps, operations, elements, components and / or collections thereof.

[0037] It should also be understood that the terminology used in this specification is for the purpose of describing particular embodiments only and is not intended to limit the invention. As used in this specification and the appended claims, the singular forms “a,” “an,” and “the” are intended to include the plural forms unless the context clearly indicates otherwise.

[0038] It should also be further understood that the term "and / or" as used in this specification and the appended claims refers to any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0039] The accompanying drawings illustrate various structural schematic diagrams according to embodiments disclosed in this invention. These drawings are not to scale, and some details have been enlarged for clarity, and some details may have been omitted. The shapes of the various regions and layers shown in the drawings, as well as their relative sizes and positional relationships, are merely exemplary and may deviate from reality due to manufacturing tolerances or technical limitations. Furthermore, those skilled in the art can design regions / layers with different shapes, sizes, and relative positions as needed.

[0040] This invention provides a two-stage rotary adsorption carbon capture device and method. Through axial partitioning of the sensible heat section 13 and the phase change section 14 of the first-stage rotary wheel 1, the raw flue gas undergoes dual cooling and precise temperature control, solving the problems of flue gas temperature fluctuations and decreased adsorption efficiency caused by adsorption heat. This ensures the flue gas temperature matches the optimal operating window of the solid amine adsorbent. By employing axial counter-current heat exchange between the flue gas and regeneration gas, the phase change material achieves a closed-loop cycle of heat absorption and energy storage and heat release, improving heat utilization, reducing regeneration energy consumption, and solving the problems of large thermal inertia and heat waste in traditional rotary heating systems.

[0041] A semi-open regeneration cycle combined with waste heat recovery from the heat exchanger enables the cascade utilization of waste heat from the desorption tail gas. An auxiliary heater 5 provides temperature compensation, ensuring stable and controllable temperature of the mixed regeneration gas. The second-stage rotor 2 is equipped with a cooling zone 23 and a cooling gas circuit 6, utilizing purified flue gas to cool the desorbed second-stage rotor 2, preventing the high-temperature rotor 2 from directly entering the adsorption zone 21. This solves the problem of insufficient thermal coupling in the second-stage rotor, ensuring efficient and continuous adsorption. The dual-stage rotors rotate in zones, achieving simultaneous and continuous adsorption, regeneration, and cooling operations. Please see Figure 1 As shown, the present invention discloses a two-stage rotary adsorption carbon capture device, comprising a first-stage rotary wheel 1 and a second-stage rotary wheel 2. The first-stage rotary wheel 1 is divided into an endothermic zone 11 and an exothermic zone 12 along its rotation direction.

[0042] Specifically, such as Figure 1 As shown, the outlet side of the heat absorption zone 11 is connected to the adsorption zone 21, and the inlet side of the heat absorption zone 11 is connected to the original flue gas. The heat absorption zone 11 is used to absorb heat when the original flue gas passes through, so as to reduce the flue gas temperature and stabilize the flue gas temperature within a set range.

[0043] The second-stage rotor 2 has a CO2 solid amine adsorbent loaded on its rotor substrate, specifically polyethyleneimine / porous carrier, amino-functionalized MOF, etc. The second-stage rotor 2 is divided into an adsorption zone 21 and a desorption zone 22 along the rotation direction. The adsorption zone 21 is used to adsorb CO2 as the raw flue gas passes through. The desorption zone 22 is used to introduce a high-temperature mixed regeneration gas to desorb high-concentration CO2.

[0044] Meanwhile, the outlet side of the heat release zone 12 is connected to the desorption zone 22, and the inlet side of the heat release zone 12 is connected to the mixed regeneration gas used for desorption. The heat release zone 12 is used to release heat when the mixed regeneration gas passes through, so as to increase the temperature of the desorbed mixed gas.

[0045] Therefore, by setting up a first-stage rotor 1 with an endothermic zone 11 and an exothermic zone 12 and a second-stage rotor 2 with an adsorption zone 21 and a desorption zone 22, and connecting the outlet of the endothermic zone 11 to the adsorption zone 21 and the outlet of the exothermic zone 12 to the desorption zone 22, on the one hand, the endothermic zone 11 absorbs heat from the original flue gas to cool it down and stabilize its temperature, solving the problems of flue gas temperature fluctuation, bed temperature rise caused by adsorption heat, and CO2 adsorption capacity reduction in the prior art. At the same time, the flue gas temperature entering the adsorption zone 21 is stably adapted to the working window of the adsorbent, solving the problems of temperature mismatch before and after multi-stage adsorption and low capture efficiency, thus achieving continuous, stable, and efficient carbon capture as a whole. On the other hand, the exothermic zone 12 is used to heat the mixed regeneration gas to achieve heat recovery and utilization and reduce regeneration energy consumption.

[0046] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations. Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0047] Please see Figure 1 As shown, in a two-stage rotor adsorption carbon capture device of the present invention, the rotor substrate of the first-stage rotor 1 is a honeycomb ceramic or metal material, which has high thermal conductivity and good mechanical strength. The first-stage rotor 1 is divided into a sensible heat section 13 and a phase change section 14 along its axial direction.

[0048] The sensible heat section 13 is located on the original flue gas inlet side, does not contain phase change materials, and uses the sensible heat of the rotor substrate to perform preliminary heat exchange with the flue gas.

[0049] Phase change section 14 is located on the original flue gas outlet side and is loaded with phase change material. It can exchange heat with the corresponding flue gas by utilizing the heat absorption melting and heat release solidification of the phase change material.

[0050] Specifically, the flue gas flow direction in the heat absorption zone 11 is from the sensible heat section 13 to the phase change section 14. The original flue gas first passes through the sensible heat section 13 and exchanges heat with the rotor base of the first-stage rotor 1 for a first cooling. When the flue gas continues to flow through the phase change section 14, the phase change material absorbs the heat of the flue gas and melts, and the flue gas is cooled a second time to the set range.

[0051] In this configuration, the first-stage rotor 1 is axially divided into a sensible heating section 13 and a phase change section 14, and the flue gas is confined to flow along the direction from the sensible heating section 13 to the phase change section 14. When passing through the sensible heating section 13, the flue gas undergoes a sensible cooling process with the substrate, achieving initial temperature control. The flue gas then passes through the phase change section 14, where it undergoes a second, precise cooling process by absorbing heat from the melting of the phase change material. This dual cooling stabilizes the flue gas temperature within the set range, preventing temperature fluctuations from affecting the adsorption efficiency. Simultaneously, the phase change section 14, loaded with phase change material, can store a large amount of heat, providing a stable heat source for subsequent regeneration gas heating and improving overall heat utilization.

[0052] Preferably, in this embodiment, the flue gas flow direction of the heat release zone 12 is from the phase change section 14 to the sensible heat section 13. The mixed regeneration gas passes through the heat release zone 12 along the direction from the phase change section 14 to the sensible heat section 13.

[0053] When the mixed regenerated gas first passes through the phase change section 14, the phase change material solidifies and releases heat, thus heating the mixed regenerated gas for the first time. When the mixed regenerated gas continues to flow through the sensible heat section 13, it absorbs the sensible heat of the rotor base of the first-stage rotor 1, thus heating the mixed regenerated gas for the second time.

[0054] In the exothermic zone 12, the mixed regenerated gas flows from the phase change section 14 to the sensible heat section 13. The mixed regenerated gas first passes through the phase change section 14 to release latent heat through the solidification of the phase change material, achieving primary heating. Then, it passes through the sensible heat section 13 to absorb the sensible heat of the substrate, achieving secondary heating. This forms a counter-current stepped heat exchange, making the regenerated gas heat up more fully and the temperature more uniform, significantly improving heat recovery efficiency and reducing auxiliary heating energy consumption. At the same time, the counter-current flow forms a matched heat exchange with the flue gas side, ensuring a stable and continuous heat absorption and release cycle in the first-stage rotor 1.

[0055] Preferably, in this embodiment, the phase change material can be an organic or inorganic phase change material with a melting point of 75-85℃ and a latent heat of phase change ≥180 kJ / kg. This melting point range ensures sufficient melting and heat absorption during flue gas cooling and sufficient condensation and heat release during regeneration gas heating, balancing stable heat absorption and release. The high latent heat characteristic results in a higher heat storage density per unit mass of material, achieving greater heat throughput within a limited rotor volume, enhancing flue gas temperature stabilization and regeneration gas heating capacity, and improving the overall energy efficiency of the device.

[0056] Preferably, in this embodiment, the phase change material may be paraffin-based; in other embodiments, the phase change material may also be hydrated salts, fatty acids, etc.

[0057] Specifically, similar to existing rotors, the rotor substrate of the first-stage rotor 1 in this application is provided with a microporous structure, and the phase change material is encapsulated in the microporous structure to complete the division of the phase change section 14 and the sensible heat section 13.

[0058] Preferably, the heat absorption zone 11 occupies 240°-300° of the circumference of the first-stage rotor 1, and the heat release zone 12 occupies 60°-120° of the circumference of the first-stage rotor 1.

[0059] Specifically, in this embodiment, the heat absorption zone 11 occupies 240° of the circumference of the first-stage rotor 1, and the heat release zone 12 occupies 120° of the circumference of the first-stage rotor 1. In another embodiment, the heat absorption zone 11 occupies 300° of the circumference of the first-stage rotor 1, and the heat release zone 12 occupies 60° of the circumference of the first-stage rotor 1. In yet another embodiment, the heat absorption zone 11 occupies 280° of the circumference of the first-stage rotor 1, and the heat release zone 12 occupies 80° of the circumference of the first-stage rotor 1. In this embodiment, as Figure 1 As shown, the device also includes a mixer, a fresh replenishment gas module and a circulating fan 3. The outlet side of the desorption zone 22 is provided with a circulating gas branch 7 and a product gas branch 8. The inlet side of the mixer is connected to the fresh replenishment gas module and the circulating gas branch 7 to provide desorption mixed gas. The outlet side of the mixer is connected to the exothermic zone 12.

[0060] Specifically, the regenerated gas discharged from the outlet side of desorption zone 22 is divided into two paths through recirculating gas branch 7 and product gas branch 8. A fresh replenishment gas module is used to supply fresh replenishment gas; the gas from the branch of recirculating gas branch 7 is mixed with air through a mixer to form a mixed regenerated gas for desorption. Specifically, the fresh replenishment gas module includes a supply fan; the fresh replenishment gas is pressurized by the recirculating fan 3 and then enters the mixer.

[0061] In this embodiment, the fresh replenishment gas is ambient air. In other embodiments, the fresh replenishment gas can also be purified smoke after adsorption, specifically taken from the outlet of adsorption zone 21, with a temperature of 44 to 55 degrees Celsius.

[0062] By adding a mixer, a fresh replenishment gas module, and a recirculation gas branch 7, the gas at the outlet of the desorption zone 22 is split into product gas and recirculation gas. The recirculation gas is returned and mixed with the fresh replenishment gas to form regeneration gas, forming a semi-open regeneration cycle. This can not only stably provide a regeneration gas source and maintain the system pressure balance, but also recover the waste heat of the desorption tail gas, reduce the amount of fresh gas used and heat loss, and reduce regeneration energy consumption.

[0063] Preferably, in this embodiment, the device further includes a heat exchange module, the product gas branch 8 is connected to the outlet of the mixer via the heat exchange module, and the flue gas of the product gas branch 8 heats the mixed regenerated gas of the mixer through the heat exchange module.

[0064] A heat exchange module is added to preheat the mixed regenerated gas using the high-temperature exhaust gas from the product gas branch 8, thereby achieving the cascade recovery of waste heat from the desorption exhaust gas. The mixed regenerated gas is preheated before entering the heat release zone 12 of the first-stage rotor 1, reducing the heating load of the phase change section 14 and the sensible heat section 13 and improving the overall heat utilization rate.

[0065] Specifically, in this embodiment, the heat exchange module is a gas-to-gas heat exchanger 4. The gas-to-gas heat exchanger 4 is provided with a low-temperature channel and a high-temperature channel. The low-temperature mixed regeneration gas enters the cold side inlet of the low-temperature channel of the gas-to-gas heat exchanger 4, and the high-temperature exhaust gas of the product gas branch 8 enters the hot side inlet of the high-temperature channel of the gas-to-gas heat exchanger 4.

[0066] Heat exchange is achieved through the wall surface. The high-temperature exhaust gas in the high-temperature channel is used to heat the mixed regeneration gas in the low-temperature channel. The high-temperature exhaust gas releases residual heat, and the low-temperature mixed regeneration gas is preheated, with the temperature rising from room temperature to 80 to 100°C.

[0067] The preheated cryogenic mixed regenerated gas enters the phase change section 14, and its preheated temperature is adapted to the phase change temperature of the phase change material. In practical applications, there are many types of phase change materials that can meet the requirements. Therefore, in other embodiments, depending on the application scenario, when different phase change materials are used, the temperature of the preheated cryogenic mixed regenerated gas entering the phase change section 14 can be adjusted using the gas-to-gas heat exchanger 4. Therefore, this application does not impose specific limitations on the specific temperature of the preheated cryogenic mixed regenerated gas.

[0068] After heat exchange, the high-temperature exhaust gas is discharged as product gas from the cold side outlet of the high-temperature channel, resulting in high-purity CO2 product gas for subsequent storage and resource utilization. The low-temperature mixed regeneration gas enters the heat release zone 12 of the first-stage rotor 1 from the hot side outlet of the low-temperature channel.

[0069] In this embodiment, preferably, an auxiliary heater 5 is provided between the outlet side of the exothermic zone 12 and the desorption zone 22. Providing the auxiliary heater 5 between the outlet of the exothermic zone 12 and the desorption zone 22 enables temperature compensation and precise control of the mixed regeneration gas heated by the first-stage rotor 1 in the exothermic zone 12, ensuring that the gas temperature entering the second-stage rotor 2 in the desorption zone 22 stably reaches the optimal desorption temperature range of the solid amine adsorbent.

[0070] Specifically, after the mixed regenerated gas is heated in the exothermic zone 12, if the temperature still does not reach the desorption temperature required (100 to 140°C), heat is supplemented by the auxiliary heater 5 to raise the gas temperature to the required level. Specifically, the auxiliary heater 5 can be an electric heater or a steam heater.

[0071] Preferably, in this embodiment, such as Figure 1As shown, the second-stage rotor 2 is also provided with a cooling zone 23. The second-stage rotor 2 is divided into an adsorption zone 21, a desorption zone 22 and a cooling zone 23 in sequence along its rotation direction. A cooling gas circuit 6 is provided between the gas outlet side of the adsorption zone 21 and the cooling zone 23.

[0072] Specifically, the adsorption zone 21 occupies 180°-240° of the circumference of the second-stage rotor 2, the desorption zone 22 occupies 60°-90° of the circumference of the second-stage rotor 2, and the cooling zone 23 occupies 30°-90° of the circumference of the second-stage rotor 2.

[0073] Specifically, in this embodiment, the adsorption zone 21 occupies 180° of the circumference of the second-stage rotor 2, the desorption zone 22 occupies 90° of the circumference of the second-stage rotor 2, and the cooling zone 23 occupies 90° of the circumference of the second-stage rotor 2.

[0074] In another embodiment, the adsorption zone 21 occupies 240° of the circumference of the second-stage rotor 2, the desorption zone 22 occupies 90° of the circumference of the second-stage rotor 2, and the cooling zone 23 occupies 30° of the circumference of the second-stage rotor 2.

[0075] In another embodiment, the adsorption zone 21 occupies 240° of the circumference of the second-stage rotor 2, the desorption zone 22 occupies 60° of the circumference of the second-stage rotor 2, and the cooling zone 23 occupies 60° of the circumference of the second-stage rotor 2. In another embodiment, the adsorption zone 21 occupies 200° of the circumference of the second-stage rotor 2, the desorption zone 22 occupies 80° of the circumference of the second-stage rotor 2, and the cooling zone 23 occupies 80° of the circumference of the second-stage rotor 2. In other embodiments, the circumferential proportions of the adsorption zone 21, desorption zone 22 and cooling zone 23 can be set according to actual needs, and this application does not make specific limitations.

[0076] A cooling zone 23 is added to the second-stage rotor 2, and the rotor is divided into zones in the order of adsorption zone 21 → desorption zone 22 → cooling zone 23. At the same time, the purified flue gas from the outlet of adsorption zone 21 is introduced into the cooling zone 23 through the cooling gas circuit 6. The low-temperature purified flue gas is used to cool the second-stage rotor 2 after desorption, so that the second-stage rotor 2 drops to a suitable adsorption temperature before rotating back to adsorption zone 21. This avoids the high temperature after desorption from directly entering adsorption zone 21, which would cause a decrease in adsorption capacity. This solves the problems of insufficient thermal coupling of the second-stage rotor and the impact of high temperature on adsorption performance, and significantly improves the continuous collection efficiency.

[0077] The present invention provides a two-stage rotary adsorption carbon capture method, applied to the aforementioned two-stage rotary adsorption carbon capture device, which specifically includes the following steps: 1. Raw flue gas treatment process Before entering the device, the raw flue gas first passes through a primary cooler, where it is initially cooled to 100-120℃.

[0078] Subsequently, the raw flue gas passes through the heat absorption zone 11 of the first-stage rotor 1. The heat absorption zone 11 absorbs heat from the raw flue gas and reduces its temperature to within a set range.

[0079] Specifically, the raw flue gas first passes through the sensible heat section 13, where it exchanges heat with the rotor base of the first-stage rotor 1 and is cooled to 90-100℃. Then, in the phase change section 14, the phase change material absorbs heat from the flue gas and melts, further reducing the flue gas temperature to 45-55℃.

[0080] The flue gas at this temperature enters the adsorption zone 21 of the second-stage rotor 2, where CO2 is captured by the solid amine adsorbent, and the purified flue gas is discharged from the outlet of the adsorption zone 21. The purified flue gas then enters the cooling zone 23 of the second-stage rotor 2 as a cooling medium.

[0081] In other embodiments, the temperature of the original flue gas after heat exchange between the sensible heat section 13 and the rotor substrate of the first-stage rotor 1 can be adaptively adjusted according to actual usage requirements, such as cooling down to the range of 80 to 100°C, or cooling down to the range of 70 to 90°C, as long as it is ensured that the temperature of the original flue gas after heat absorption through phase change can be reduced to the appropriate range for adsorption, and there are no specific limitations.

[0082] 2. Mixed Regeneration Gas Treatment Process The mixed regenerated gas passes through the heat release zone 12 of the first-stage rotor 1, where the heat release zone 12 releases heat to the mixed regenerated gas, increasing its temperature. After being heated, the mixed regenerated gas enters the desorption zone 22 of the second-stage rotor 2 for CO2 desorption.

[0083] Specifically, the mixed regeneration gas is composed of fresh makeup gas and recirculated gas. The fresh makeup gas is ambient air or purified flue gas, which is pressurized by the circulating fan 3 before entering the mixer. The recirculated gas is a portion diverted from the gas exiting the desorption zone 22, specifically the gas in the recirculated gas branch 7, accounting for 20%-40% of the total gas volume at the outlet of the desorption zone 22, with a temperature of 60-80℃, and also enters the mixer.

[0084] The mixed regenerated gas, with a temperature of 50-70℃, enters the cold-side inlet of the gas-to-gas heat exchanger 4. The product gas from the product gas branch 8 at the outlet of desorption zone 22 accounts for 60%-80% of the total gas volume at the outlet of desorption zone 22 and enters the hot-side inlet of the gas-to-gas heat exchanger 4 at a temperature of 90-110℃. The mixed regenerated gas and product gas undergo countercurrent heat exchange, and the mixed regenerated gas is preheated to 80-100℃.

[0085] The preheated mixed regenerated gas enters the exothermic zone 12 of the first-stage rotor 1, first passing through the phase change section 14. The liquid phase change material, which previously stored heat in the heat absorption zone 11, releases heat and solidifies into a solid state, releasing the latent heat of phase change. The mixed regenerated gas absorbs heat and its temperature rises to 90-110℃. Then it passes through the sensible heat section 13. The heated mixed regenerated gas continues to flow through the sensible heat section 13, absorbing the sensible heat stored in the rotor matrix of the first-stage rotor 1, completing heat recovery. The temperature of the mixed regenerated gas further increases to 100-120℃.

[0086] The heated mixed regenerated gas moves toward the desorption zone 22 of the second-stage rotor 2. If the gas temperature does not reach the required 100-140°C for desorption, the auxiliary heater 5 is used to supplement the heat and raise the gas temperature to 100-140°C.

[0087] The high-temperature mixed regeneration gas enters the desorption zone 22 of the second-stage rotor 2, where CO2 is desorbed. The temperature of the gas discharged from the desorption zone 22 drops to 90-110℃.

[0088] The gas exiting desorption zone 22 enters a splitter, which separates it into a recirculating gas branch 7 and a product gas branch 8. Product gas branch 8, as the main stream, accounts for 60%-80% of the total outlet gas and serves as the product gas extraction system, entering subsequent compression, storage, or utilization units. Recirculating gas branch 7, as a secondary stream, accounts for 20%-40% of the total outlet gas and returns to the mixer as recirculating gas, mixing with fresh replenishment gas to begin the next regeneration cycle.

[0089] The temperature parameters of each stage of the mixed regenerated gas process, as well as the proportions of product gas and regenerated gas to the total amount of desorption outlet gas, can be adjusted according to actual needs. This application does not impose specific restrictions, as long as the overall processing flow, circulation process, and product gas output of the mixed regenerated gas are met.

[0090] 3. Cooling process of the second-stage rotor 2 Before the second-stage rotor 2 rotates from the desorption zone 22 to the adsorption zone 21, it needs to pass through the cooling zone 23.

[0091] The cooling medium is a portion of the purified flue gas drawn from the outlet of adsorption zone 21, with a temperature of 45-55℃. This gas passes through cooling zone 23, absorbs the heat stored in the rotor, and cools the rotor area to 40-60℃ before being discharged. Specifically, it can be connected to the main exhaust pipe or used as combustion air. The cooled rotor enters adsorption zone 21, ensuring low-temperature and high-efficiency adsorption.

[0092] In this embodiment, the following method control parameters are given: The phase change material in the first-stage rotor 1 has a melting point of 75-85℃, balancing the melting in the endothermic zone 11 and the solidification in the exothermic zone 12. In other embodiments, other phase change materials are used, and the phase change melting point can be adjusted according to requirements. How to select and use them is common knowledge well known to those skilled in the art, and will not be elaborated on here.

[0093] The outlet flue gas temperature of the first-stage rotor 1 heat absorption zone 11 is 45-55℃, which matches the optimal adsorption temperature of the second-stage adsorbent.

[0094] The inlet flue gas temperature of the adsorption zone 21 of the second-stage rotor is 45-55℃.

[0095] The inlet regeneration gas temperature of the desorption zone 22 of the second-stage rotor is 100-140℃, which matches the solid amine desorption temperature window.

[0096] The outlet temperature of the second-stage rotor 2 cooling zone 23 is 40-60℃, ensuring low temperature and high efficiency in the adsorption zone 21.

[0097] The cold side outlet temperature of the gas-to-gas heat exchanger 4 is 80-100℃.

[0098] The outlet temperature of the hot side of the gas-to-gas heat exchanger is 60-80℃, which is the temperature of the product gas.

[0099] The proportion of recirculated gas at the outlet of desorption zone 22 is 20%-40%.

[0100] The typical CO2 concentration in the product gas of a semi-open circulation system is 70%-85%.

[0101] In summary, the two-stage rotary adsorption carbon capture device and method of the present invention, through the axial partitioning of the sensible heat section 13 and the phase change section 14 of the first-stage rotary wheel 1, performs dual cooling and precise temperature control on the original flue gas, solves the problem of flue gas temperature fluctuation and adsorption heat-induced decrease in adsorption efficiency, and makes the flue gas temperature match the optimal working window of the solid amine adsorbent.

[0102] The system employs axial counter-current heat exchange between flue gas and regenerated gas, utilizing phase change materials to achieve a closed-loop cycle of heat absorption and energy storage and release, thereby improving heat utilization efficiency, reducing regeneration energy consumption, and solving the problems of high thermal inertia and heat waste associated with traditional rotary heating systems. A semi-open regeneration cycle combined with a gas-to-gas heat exchanger 4 enables waste heat recovery, achieving cascaded utilization of the desorption tail gas waste heat. An auxiliary heater 5 provides temperature compensation, ensuring stable and controllable temperature and humidity of the mixed regenerated gas.

[0103] The second-stage rotor 2 is equipped with a cooling zone 23 and a cooling gas circuit 6. The purified flue gas is used to cool the desorbed second-stage rotor 2, preventing the high-temperature rotor 2 from directly entering the adsorption zone 21. This solves the problem of insufficient thermal coupling in the second-stage rotor and ensures efficient and continuous adsorption. The dual-stage rotors rotate in zones, achieving simultaneous and uninterrupted continuous operation of adsorption, regeneration, and cooling.

[0104] The above content is only for illustrating the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. Any modifications made to the technical solution based on the technical concept proposed in this invention shall fall within the scope of protection of the claims of this invention.

Claims

1. A two-stage rotary adsorption carbon capture device, characterized in that, Includes a first-stage rotor (1) and a second-stage rotor (2); The first-stage rotor (1) is divided into an endothermic zone (11) and an exothermic zone (12) along its rotation direction, and the second-stage rotor (2) is divided into an adsorption zone (21) and a desorption zone (22) along its rotation direction. The outlet side of the heat absorption zone (11) is connected to the adsorption zone (21), and the inlet side of the heat absorption zone (11) is connected to the original flue gas. The heat absorption zone (11) is used to absorb heat when the original flue gas passes through, so as to reduce the flue gas temperature and stabilize the flue gas temperature within a set range. The outlet side of the heat release zone (12) is connected to the desorption zone (22), and the inlet side of the heat release zone (12) is connected to the mixed regeneration gas for desorption. The heat release zone (12) is used to release heat when the mixed regeneration gas passes through, so as to increase the temperature of the desorbed mixed gas.

2. The dual-stage rotary adsorption carbon capture device according to claim 1, characterized in that, The first rotor is divided into a sensible heat section (13) and a phase change section (14) along its axial direction, and the phase change section (14) is loaded with a phase change material; The flue gas flow direction of the heat absorption zone (11) is from the sensible heat section (13) to the phase change section (14). The original flue gas passes through the sensible heat section (13) and exchanges heat with the rotor base of the first stage rotor (1) to achieve a cooling. The flue gas passes through the phase change section (14), where the phase change material absorbs heat from the flue gas and melts, allowing the flue gas to be cooled to a set range in a second stage.

3. The dual-stage rotary adsorption carbon capture device according to claim 2, characterized in that, The flue gas flow direction of the heat release zone (12) is from the phase change section (14) to the sensible heat section (13). The mixed regeneration gas passes through the phase change section (14), and the phase change material solidifies and releases heat, thus undergoing a first heating. The mixed regenerated gas passes through the sensible heat section (13) and absorbs the sensible heat of the rotor base of the first-stage rotor (1) for secondary heating.

4. The dual-stage rotary adsorption carbon capture device according to claim 2, characterized in that, The phase change material has a melting point of 75-85℃ and a latent heat of phase change of ≥180 kJ / kg.

5. The dual-stage rotary adsorption carbon capture device according to claim 4, characterized in that, The phase change material is one of paraffin-based, hydrated salt, or fatty acid-based materials.

6. The dual-stage rotary adsorption carbon capture device according to claim 2, characterized in that, It also includes a mixer and a fresh replenishment gas module. The outlet side of the desorption zone (22) is provided with a circulating gas branch (7) and a product gas branch (8). The inlet side of the mixer is connected to the fresh replenishment gas module and the circulating gas branch (7) to provide mixed regeneration gas. The outlet side of the mixer is used to connect to the exothermic zone (12).

7. The dual-stage rotary adsorption carbon capture device according to claim 6, characterized in that, It also includes a heat exchange module, wherein the product gas branch (8) is connected to the outlet of the mixer via the heat exchange module, and the flue gas of the product gas branch (8) is heated by the heat exchange module to generate mixed regenerated gas.

8. The dual-stage rotary adsorption carbon capture device according to claim 1, characterized in that, An auxiliary heater (5) is provided between the outlet side of the heat release zone (12) and the desorption zone (22).

9. The dual-stage rotary adsorption carbon capture device according to claim 1, characterized in that, The second stage rotor (2) is also provided with a cooling zone (23). The second stage rotor (2) is arranged in the following order along its rotation direction: adsorption zone (21), desorption zone (22) and cooling zone (23). A cooling gas circuit (6) is provided between the gas outlet side of the adsorption zone (21) and the cooling zone (23).

10. A method for capturing carbon through a two-stage rotary adsorption system, applied to the two-stage rotary adsorption carbon capture device according to any one of claims 1 to 9, characterized in that, include: The raw flue gas passes through the heat absorption zone (11) of the first stage rotor (1). The heat absorption zone (11) absorbs heat from the raw flue gas and reduces the temperature of the raw flue gas within the set range. After being cooled, the raw flue gas enters the adsorption zone (21) of the second-stage rotor (2) for adsorption, and the purified flue gas is discharged from the outlet of the adsorption zone (21). The mixed regenerated gas passes through the heat release zone (12) of the first stage rotor (1), where the heat release zone (12) releases heat to the mixed regenerated gas, increasing its temperature. After the temperature rises, the mixed regenerated gas enters the desorption zone (22) of the second stage rotor (2) for CO2 desorption.

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