Catalytic desorption system

Abstract

The application provides a catalytic desorption system, relates to the technical field of carbon dioxide capture, and is used for improving the desorption efficiency of a desorption system. The catalytic desorption system comprises a shell and a plurality of desorption devices; the desorption devices are sequentially and spacedly arranged from the bottom of the shell to the top of the shell; each desorption device comprises a first pipe body, a heating pipe, a catalytic converter and a support plate provided with a through hole; the first pipe body, the support plate and the part of the shell corresponding to the first pipe body enclose a desorption groove, and the heating pipe and the catalytic converter are arranged in the desorption groove; any two adjacent desorption grooves are configured such that when the rich amine solution in the upper desorption groove exceeds the volume of the corresponding desorption groove, the rich amine solution overflows to the lower desorption groove through the gap between the corresponding first pipe body and the second pipe body arranged in the upper desorption device, and the carbon dioxide is released through the second pipe body; the shell is further provided with an input interface, an output interface and an exhaust port.

Description

Technical Field

[0001] This invention relates to the field of carbon dioxide capture technology, and more particularly to a catalytic desorption system. Background Technology

[0002] Carbon dioxide capture refers to the extraction and purification of carbon dioxide from fossil fuel power plants or industrial facilities. Methods include chemical absorption, physical absorption, adsorption, and membrane separation. Currently, chemical absorption, primarily using organic amine solutions, is widely used in large-scale industrial applications. This method involves organic amine solutions absorbing carbon dioxide-containing gas, transforming it into a carbon dioxide-rich amine solution. This solution is then desorbed by sequentially spaced desorption devices arranged from bottom to top within a desorption system at high temperatures, releasing the carbon dioxide and thus achieving capture. However, this desorption system suffers from low desorption efficiency. Summary of the Invention

[0003] This invention provides a catalytic desorption system for improving the desorption efficiency of a desorption system.

[0004] To achieve the above objectives, the embodiments of the present invention provide the following technical solutions:

[0005] This invention provides a catalytic desorption system for desorbing carbon dioxide from an amine-rich liquid. The catalytic desorption system includes a shell and multiple desorption devices. Each desorption device is arranged at intervals from the bottom to the top of the shell. Each desorption device includes a first tube, a heating tube, a catalyst, and a support plate with through holes.

[0006] In the same desorption device, the support plate is attached to the inner wall of the housing; the first tube is mounted on the support plate and communicates with the through hole; the first tube, the support plate, and the portion of the housing corresponding to the first tube form a desorption groove, and the heating tube and the catalyst are disposed in the desorption groove;

[0007] In any two adjacent desorption devices, the upper desorption device further includes a second tube, which is installed in the first tube and through hole of the corresponding desorption device, and the top of the second tube is higher than the top of the first tube.

[0008] Any two adjacent desorption tanks are configured such that when the rich amine liquid in the upper desorption tank exceeds the volume of the corresponding desorption tank, the rich amine liquid overflows into the lower desorption tank through the gap between the corresponding first tube and the corresponding second tube.

[0009] The housing is also provided with an input interface, an output interface and an exhaust port. The input interface is connected to the uppermost desorption tank among the desorption tanks. The output interface is connected to the lowermost first tube among the first tubes. The exhaust port is located at the top of the housing.

[0010] The catalytic desorption system provided in this embodiment of the invention has the following beneficial effects:

[0011] The catalytic desorption system provided in this embodiment of the invention includes a housing and multiple desorption devices, which are arranged sequentially from the bottom to the top of the housing. Each desorption device includes a first tube, a heating tube, a catalyst, and a support plate with a through hole. The support plate is attached to the inner wall of the housing. The first tube is mounted on the support plate and communicates with the through hole. The first tube, the support plate, and the portion of the housing corresponding to the first tube form a desorption groove. The heating tube and the catalyst are arranged inside the desorption groove. The housing is also provided with an input interface, an output interface, and an exhaust port. The input interface is connected to the uppermost desorption groove, the output interface is connected to the lowermost first tube, and the exhaust port is located at the top of the housing.

[0012] After the rich amine solution enters the uppermost desorption tank through the input interface, it undergoes its first decomposition due to the presence of heating tubes and catalysts in each desorption tank. This desorption produces carbon dioxide, which is then discharged through the exhaust port. When the volume of the rich amine solution in the uppermost desorption tank exceeds its capacity, the solution overflows into the lower desorption tank through the gap between the first and second tubes. This overflow occurs repeatedly until the solution overflows into the lowermost desorption tank, completing the final desorption process. The solution is then discharged through the lowermost first tube and the output interface. Except for the carbon dioxide desorbed during the first desorption, all other carbon dioxide desorbed during the subsequent desorption processes are discharged through the second tube and the exhaust port. Therefore, compared with related technologies, the catalytic desorption system provided in this embodiment of the invention utilizes a heating tube and a catalyst to achieve the desorption of amine-rich liquid. The amine-rich liquid flows between the upper and lower desorption devices through the gap between the first and second tubes. Carbon dioxide is collected through the second tube, thereby achieving the separation of carbon dioxide desorbed by the lower desorption device and amine-rich liquid in the upper desorption device, thus improving the desorption efficiency of the desorption system.

[0013] Based on the above technical solutions, the embodiments of the present invention can be further improved as follows.

[0014] Furthermore, both the first tube and the second tube are circular tubes.

[0015] Furthermore, the axes of the first tubes, the second tubes, and the through hole are collinear.

[0016] Furthermore, in any two adjacent desorption devices, the lower desorption device further includes a barrel-shaped structure with its opening facing downwards. The bottom of the barrel-shaped structure is provided with an air hole. The barrel-shaped structure is connected to the second tube in the upper desorption device through the air hole. The barrel wall of each barrel-shaped structure is located between the inner wall of the shell and the outer wall of the corresponding first tube.

[0017] Furthermore, the bottom of each bucket protrudes relative to the bucket wall toward the top of the shell, and the cross-sectional area of ​​the bucket bottom increases progressively from the air hole at the bottom of the bucket to each edge of the bottom of the bucket, with a plane perpendicular to the axis of the air hole as the cross-section.

[0018] Furthermore, each of the heating tubes is filled with a heating medium.

[0019] Furthermore, the desorption temperature provided by each of the heating media is 80-95°C. The desorption temperature gradually increases from the top of the shell towards the bottom of the shell, and the difference in desorption temperature between two adjacent desorption devices is 2-3°C.

[0020] Furthermore, the catalytic desorption system also includes a vacuum device with an inlet and an outlet, the inlet being connected to the outlet, the gas pressure inside the vacuum device being lower than the gas pressure inside the housing, and the vacuum degree of the vacuum device being 10-50 kPa.

[0021] Furthermore, the catalytic desorption system also includes an external circulation device, which includes a pipeline and a circulation pump. The pipeline is provided with a first interface, a second interface and a third interface in sequence along its extension direction.

[0022] The circulation pump is installed between the first interface and the second interface. The first interface is connected to the output interface. The second interface is the output end of the external circulation device. The third interface is connected to any of the desorption tanks.

[0023] The external circulation device is configured such that: the first interface receives the rich amine liquid flowing out of the desorption device located at the bottom; the circulation pump drives a portion of the rich amine liquid to flow out of the external circulation device through the second interface; and the circulation pump drives another portion of the rich amine liquid to flow back into the desorption tank through the third interface.

[0024] Furthermore, the catalytic desorption system also includes a demister, the outer surface of which is attached to the inner wall of the housing, and the demister is located closer to the top of the housing relative to each of the desorption devices.

[0025] In addition to the technical problems solved by the embodiments of the present invention, the technical features constituting the technical solutions, and the beneficial effects brought about by the technical features of these technical solutions described above, other technical problems that the catalytic desorption system provided by the embodiments of the present invention can solve, other technical features included in the technical solutions, and the beneficial effects brought about by these technical features will be further explained in detail in specific embodiments. Attached Figure Description

[0026] To more clearly illustrate the technical solutions in the embodiments of the present invention or related technologies, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. 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 the structures shown in these drawings without creative effort.

[0027] Figure 1 This is a schematic diagram of the catalytic desorption system provided in an embodiment of the present invention;

[0028] Figure 2 for Figure 1 A schematic diagram of the cross-section of surface AA.

[0029] Explanation of reference numerals in the attached figures:

[0030] 100 - Shell; 200 - Desorption device;

[0031] 300 - Vacuum device; 400 - External circulation device;

[0032] 500 - Demister; 101 - Input interface;

[0033] 102 - Output interface, 103 - Exhaust port;

[0034] 210 - Support plate, 220 - First tube body;

[0035] 230 - Heating element; 240 - Catalyst.

[0036] 250-desorption tank, 260-second tube body;

[0037] 270 - Barrel-shaped structure; 410 - Pipe;

[0038] 420 - Circulation pump. Detailed Implementation

[0039] As described in the background section, desorption systems in related technologies suffer from low desorption efficiency. The inventors of this invention have discovered that in related technologies, the desorption system provides a high-temperature environment. Under this high-temperature environment, the amine-rich solution is desorbed by multiple desorption devices within the system, releasing carbon dioxide and thus achieving carbon dioxide capture. However, because the carbon dioxide desorbed by the lower desorption device continuously contacts the amine-rich solution in the upper desorption device, the carbon dioxide concentration in the upper desorption device continuously increases, thereby reducing the desorption efficiency of the system.

[0040] To address the aforementioned technical problems, the catalytic desorption system provided in this embodiment of the invention utilizes a heating tube and a catalyst within the desorption device to achieve the desorption of rich amine liquid. The rich amine liquid flows between the upper and lower desorption devices through a gap between a first tube and a second tube within the desorption device. Carbon dioxide is collected through the second tube, which is located within the first tube. This separation of the carbon dioxide desorbed by the lower desorption device and the rich amine liquid in the upper desorption device improves the desorption efficiency of the system.

[0041] 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 a part of the embodiments of the present invention, and not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0042] This invention provides a catalytic desorption system for releasing carbon dioxide from a rich amine solution, such as... Figure 1 and Figure 2 As shown, the catalytic desorption system includes a housing 100 and a plurality of desorption devices 200, which are arranged sequentially at intervals from the bottom to the top of the housing 100.

[0043] The shell 100 is the main body of the catalytic desorption system, used to support each desorption device 200. The shell 100 can be made of stainless steel, and its shape is generally a hollow tower, a near-hollow tower, a hollow cylinder, or a near-hollow cylinder, such as... Figure 1 and Figure 2 As shown, in this embodiment, the shell 100 is approximately hollow cylindrical in shape. The desorption device 200 is used to desorb the amine-rich liquid to release carbon dioxide. The number of desorption devices 200 can be three, four, or five; in this embodiment, the number of desorption devices 200 is four.

[0044] like Figure 1As shown, the housing 100 is also provided with an input interface 101, an output interface 102, and an exhaust port 103. The input interface 101 is the channel for the amine-rich liquid to enter the housing 100, and it connects to the uppermost desorption tank among the desorption tanks described below. The output interface 102 is the channel for the amine-rich liquid to leave the housing 100, and it connects to the lowermost first tube among the first tubes described below. The exhaust port 103 is the outlet for carbon dioxide within the housing 100, and it is located at the top of the housing 100.

[0045] Each desorption device 200 includes a support plate 210 with a through hole, a first tube 220, a heating tube 230, and a catalyst 240. Both the support plate 210 and the first tube 220 can be made of stainless steel. In the same desorption device 200, the support plate 210 is attached to the inner wall of the housing 100, and the first tube 220 is mounted on the support plate 210 and communicates with the through hole; or, the first tube 220 communicates with the through hole and is mounted on the upper surface of the support plate 210. The first tube 220, the support plate 210, and the portion of the housing 100 corresponding to the first tube 220 form a desorption groove 250.

[0046] The desorption tank 250 is used to desorb the rich amine solution and release carbon dioxide. The desorption tank 250 is equipped with a heating tube 230 and a catalyst 240. The heating tube 230 provides a high-temperature environment for desorbing the rich amine solution, and the catalyst 240 accelerates the desorption rate. The catalyst in the catalyst 240 can be a solid acid catalyst, such as a zeolite molecular sieve or a cation exchange resin. The desorption time of the reconstituted amine solution in the desorption tank 250 can be 10–60 seconds.

[0047] In any two adjacent desorption devices 200, the upper desorption device 200 also includes a second tube 260. The second tube 260 is used to collect the carbon dioxide released from the desorption of the amine-rich liquid. The second tube 260 is installed in the first tube 220 and the through hole of the corresponding desorption device 200, and the top of the second tube 260 is higher than the top of the first tube 220. The material of the second tube 260 can be stainless steel.

[0048] Any two adjacent desorption tanks 250 are configured such that when the volume of the rich amine solution in the upper desorption tank 250 exceeds the volume of the corresponding desorption tank 250, the rich amine solution overflows into the lower desorption tank 250 through the gap between the corresponding first tube 220 and the corresponding second tube 260. Alternatively, the rich amine solution is transferred between any two adjacent desorption tanks 250 through the gap between the first tube 220 and the corresponding second tube 260.

[0049] The catalytic desorption system provided in this embodiment of the invention utilizes the heating tube 230 and catalyst 240 within the desorption tank 250 to achieve the desorption of amine-rich liquid. The amine-rich liquid flows between any two adjacent desorption tanks 250 through the gap between the first tube 220 and the second tube 260. Carbon dioxide is collected through the second tube 260, thereby achieving the separation of carbon dioxide desorbed by the lower desorption device 200 and the amine-rich liquid in the upper desorption device 200, thus improving the desorption efficiency of the desorption system.

[0050] In some embodiments, each first tube 220 and each second tube 260 is a circular tube, and the axis of each first tube 220, the axis of each second tube 260 and the axis of the through hole are collinear. Compared with the case where the axis of the first tube 220, the axis of each second tube 260 and the axis of the through hole are not collinear, the amine-rich liquid can uniformly flow between any two adjacent desorption tanks 250 through the gap between the first tube 220 and the second tube 260, thereby further improving the desorption efficiency of the desorption system.

[0051] In some embodiments, such as Figure 1 As shown, in any two adjacent desorption devices 200, the lower desorption device 200 also includes a barrel-shaped structure 270 with its opening facing downward. The bottom of the barrel-shaped structure 270 is provided with an air hole. The barrel-shaped structure 270 is connected to the second tube 260 in the upper desorption device 200 through the air hole. The barrel wall of each barrel-shaped structure 270 is located between the inner wall of the shell 100 and the outer wall of the corresponding first tube 220.

[0052] Because the barrel-shaped structure 270 is connected to the second tube 260 in the upper desorption device 200 through the vent, the carbon dioxide desorbed by the lower desorption device 200 can flow upward through the vent and the second tube 260 in the upper desorption device 200. Simultaneously, because the barrel-shaped structure 270 is connected to the second tube 260, and the walls of each barrel-shaped structure 270 are located between the inner wall of the shell 100 and the outer wall of the corresponding first tube 220, the amine-rich liquid in the upper desorption device 200 can overflow into the desorption tank 250 in the lower desorption device 200 through the gap between the corresponding first tube 220 and the corresponding second tube 260, the outer surface of the bottom of the barrel-shaped structure 270 in the lower desorption device 200, and the outer wall of the barrel-shaped structure 270 in the lower desorption device 200.

[0053] Based on the above embodiments, the bottom of the barrel-shaped structure 270 protrudes relative to the barrel wall towards the top of the shell 100. From the air hole at the bottom of the barrel to each edge of the bottom, taking a plane perpendicular to the axis of the air hole as the cross-section, the cross-sectional area of ​​the bottom of the barrel increases progressively. In other words, with... Figure 1As shown in the example, the bottom of the barrel-shaped structure 270 protrudes upwards, and the portion of the bottom closer to the pores protrudes upwards for a greater length, meaning the shape of the bottom is approximately like a conical hat. The catalytic desorption system provided in this embodiment of the invention allows the amine-rich liquid to overflow more smoothly from the outer surface of the bottom of the barrel-shaped structure 270 and the outer wall of the barrel-shaped structure 270 into the desorption tank 250.

[0054] In some embodiments, each heating tube 230 is filled with a heating medium, which provides the desorption temperature for the amine-rich solution.

[0055] Based on the above embodiments, the desorption temperature provided by each heating medium is 80-95°C, and the heating medium can be water or steam. The desorption temperature gradually increases from the top of the shell 100 towards the bottom, with a temperature difference of 2-3°C between two adjacent desorption devices 200. The catalytic desorption system provided in this embodiment can provide a higher desorption temperature for the lower desorption device 200, thereby achieving stepwise desorption of the amine-rich liquid and completely releasing the carbon dioxide from the amine-rich liquid.

[0056] In some embodiments, the catalytic desorption system further includes a vacuum device 300 with an inlet and an outlet, the vacuum device 300 being connected to the housing 100. The vacuum device 300 can be a steam jet pump or a dry vacuum pump, used to extract the carbon dioxide desorbed by the desorption device 200. The inlet is connected to the outlet 103 of the housing 100, and the pressure inside the vacuum device 300 is lower than the pressure inside the housing 100, with a vacuum degree of 10-50 kPa. Because the pressure inside the vacuum device 300 is lower than the pressure inside the housing 100, the catalytic desorption system provided in this embodiment can capture the carbon dioxide desorbed by the desorption device 200 more quickly.

[0057] In some embodiments, the catalytic desorption system further includes an external circulation device 400, which is used in conjunction with the desorption device 200 to achieve deep desorption of the amine-rich liquid. The external circulation device 400 includes a pipe 410 and a circulation pump 420. The pipe 410 can be a circular pipe, and the pipe 410 is provided with a first interface, a second interface, and a third interface in sequence along its extension direction. The circulation pump 420 is installed between the first interface and the second interface. The first interface is connected to the output interface 102, the second interface is the output end of the external circulation device 400, and the third interface is connected to any desorption tank 250.

[0058] The external circulation device 400 is configured such that: a first interface receives the rich amine solution flowing out of the lowest desorption device 200; a circulation pump 420 drives a portion of the rich amine solution to flow out of the external circulation device 400 through a second interface; and the circulation pump 420 drives another portion of the rich amine solution to flow back into the desorption tank through a third interface. Alternatively, the rich amine solution flowing out of the lowest desorption device 200 flows into the pipe 410 through the first interface; driven by the circulation pump 420, a portion of the rich amine solution is discharged through the second interface, and the other portion re-enters the desorption tank 250 through the third interface for deep desorption. The catalytic desorption system provided in this embodiment can perform deep desorption again through the external circulation device 400 while performing multi-stage desorption, thereby making the desorption of the rich amine solution more thorough.

[0059] In some embodiments, the catalytic desorption system further includes a demister 500, the outer surface of which is attached to the inner wall of the housing 100, and the demister 500 is located closer to the top of the housing 100 relative to each desorption device 200. For example, the demister 500 may be a wire mesh demister, which includes a wire mesh and a support device for fixing the wire mesh, the outer surface of which is attached to the inner wall of the housing 100, and the wire mesh is composed of metal wires.

[0060] When carbon dioxide carrying mist passes through a wire mesh, the mist collides with the mesh and adheres to the surface of the wires. The diffusion of the mist on the wire surface and its gravitational settling cause the mist to form larger droplets that flow along the wires to the junction of the two wires. As the mist accumulates, the droplets become larger until the accumulated droplets are large enough that their own gravity exceeds the combined force of the upward force of the carbon dioxide and the surface tension of the liquid, at which point the droplets separate from the wires and fall. The catalytic desorption system provided in this embodiment can separate mist from carbon dioxide, thereby reducing impurities in the carbon dioxide and improving the desorption quality.

[0061] Other embodiments of this application will readily occur to those skilled in the art upon consideration of the specification and practice of the invention disclosed herein. This application is intended to cover any variations, uses, or adaptations of this application that follow the general principles of this application and include common knowledge or customary techniques in the art not disclosed herein. The specification and examples are to be considered exemplary only, and the true scope and spirit of this application are indicated by the following claims.

[0062] In the description of this invention, the various embodiments or implementation methods are described in a progressive manner. Each embodiment focuses on the differences from other embodiments, and the same or similar parts between the various embodiments can be referred to each other.

[0063] 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.

[0064] 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.

[0065] 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 or an electrical connection; 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.

[0066] 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.

[0067] In the description of this specification, the references to terms such as "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the present 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.

[0068] 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 catalytic desorption system, characterized in that, The catalytic desorption system is used to desorb rich amine liquid to release carbon dioxide. It includes a shell and multiple desorption devices. Each desorption device is arranged at intervals from the bottom to the top of the shell. Each desorption device includes a first tube, a heating tube, a catalyst, and a support plate with through holes. In the same desorption device, the support plate is attached to the inner wall of the housing; the first tube is mounted on the support plate and communicates with the through hole; the first tube, the support plate, and the portion of the housing corresponding to the first tube form a desorption groove, and the heating tube and the catalyst are disposed in the desorption groove; In any two adjacent desorption devices, the upper desorption device further includes a second tube, which is installed in the first tube and through hole of the corresponding desorption device, and the top of the second tube is higher than the top of the first tube. Any two adjacent desorption tanks are configured such that when the rich amine liquid in the upper desorption tank exceeds the volume of the corresponding desorption tank, the rich amine liquid overflows into the lower desorption tank through the gap between the corresponding first tube and the corresponding second tube. The housing is also provided with an input interface, an output interface and an exhaust port. The input interface is connected to the uppermost desorption tank among the desorption tanks. The output interface is connected to the lowermost first tube among the first tubes. The exhaust port is located at the top of the housing.

2. The catalytic desorption system according to claim 1, characterized in that, Both the first tube and the second tube are circular tubes.

3. The catalytic desorption system according to claim 2, characterized in that, The axes of the first tubes, the second tubes, and the through hole are collinear.

4. The catalytic desorption system according to claim 1, characterized in that, In any two adjacent desorption devices, the lower desorption device further includes a barrel-shaped structure with its opening facing downwards. The bottom of the barrel-shaped structure is provided with an air hole. The barrel-shaped structure is connected to the second tube in the upper desorption device through the air hole. The barrel wall of each barrel-shaped structure is located between the inner wall of the shell and the outer wall of the corresponding first tube.

5. The catalytic desorption system according to claim 4, characterized in that, The bottom of each barrel protrudes relative to the barrel wall toward the top of the shell. From the air hole at the bottom of the barrel to each edge of the bottom of the barrel, with a plane perpendicular to the axis of the air hole as the cross-section, the cross-sectional area of ​​the bottom of the barrel increases.

6. The catalytic desorption system according to claim 1, characterized in that, Each of the heating tubes is filled with a heating medium.

7. The catalytic desorption system according to claim 6, characterized in that, The desorption temperature provided by each of the heating media is 80-95°C. The desorption temperature gradually increases from the top of the shell towards the bottom of the shell, and the difference in desorption temperature between two adjacent desorption devices is 2-3°C.

8. The catalytic desorption system according to claim 1, characterized in that, The catalytic desorption system also includes a vacuum device with an inlet and an outlet. The inlet is connected to the outlet. The pressure inside the vacuum device is lower than the pressure inside the housing. The vacuum degree of the vacuum device is 10-50 kPa.

9. The catalytic desorption system according to claim 1, characterized in that, The catalytic desorption system also includes an external circulation device, which includes a pipeline and a circulation pump. The pipeline is provided with a first interface, a second interface and a third interface in sequence along its extension direction. The circulation pump is installed between the first interface and the second interface. The first interface is connected to the output interface. The second interface is the output end of the external circulation device. The third interface is connected to any of the desorption tanks. The external circulation device is configured such that: the first interface receives the rich amine liquid flowing out of the desorption device located at the bottom; the circulation pump drives a portion of the rich amine liquid to flow out of the external circulation device through the second interface; and the circulation pump drives another portion of the rich amine liquid to flow back into the desorption tank through the third interface.

10. The catalytic desorption system according to claim 1, characterized in that, The catalytic desorption system also includes a demister, the outer surface of which is in contact with the inner wall of the housing, and the demister is located closer to the top of the housing than each of the desorption devices.

Images