Carbon capture system

Abstract

The invention discloses a carbon capture system which comprises an absorption tower, a barren and rich liquid heat exchanger, a desorption tower, a rich liquid flow channel, a barren liquid flow channel and a reboiler, the absorption tower comprises a shell, and the shell is provided with a flue gas outlet, a rich liquid outlet, an absorption liquid inlet and a flue gas inlet; the lean-rich liquid heat exchanger comprises a first flow channel and a second flow channel, the first flow channel is provided with a first inlet and a first outlet, the second flow channel is provided with a second inlet and a second outlet, the desorption tower comprises a cylinder and a heat exchange device arranged in the cylinder, and the cylinder is provided with a carbon dioxide gas outlet, a rich liquid inlet and a lean liquid outlet. The barren liquor outlet is sequentially connected with the reboiler, the heat exchange device, the second flow channel and the absorption liquid inlet through the barren liquor flow channel, the barren liquor heated by the reboiler can perform primary heat exchange with the rich liquor flowing through the heat exchange device, then performs secondary heat exchange with the rich liquor in the first flow channel when passing through the barren liquor and rich liquor heat exchanger, and then returns to the absorption tower. The regeneration energy consumption of the absorbent can be efficiently reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon dioxide desorption, and particularly to a carbon capture system. Background Art

[0002] Currently, under the goal of carbon neutrality, the demand for carbon dioxide emission reduction is increasing year by year. Carbon capture, utilization, and storage (CCUS), which captures and purifies the carbon dioxide emitted during the production process and then inputs it into a new production process for reuse and storage), is the most direct and effective method to reduce the carbon dioxide emissions of coal-fired power plants, steel mills, and cement plants in the short term.

[0003] Among them, the chemical absorption method has the advantages of high carbon dioxide absorption rate, large absorption load, and thorough removal, and has been promoted and applied to a certain extent. The essence of carbon dioxide removal by the chemical absorption method is to use an alkaline absorbent to contact and react with carbon dioxide in the flue gas to form unstable salts; then these unstable salts decompose reversibly under certain conditions to release carbon dioxide, so as to separate and enrich carbon dioxide from the flue gas and regenerate the absorbent at the same time.

[0004] Currently, the main problem restricting the further large-scale promotion and application of this technology is the too high investment and operating costs. Among them, one of the main reasons is that the operating energy consumption is too high, and the regeneration energy consumption of the absorbent accounts for about 70% of the total system energy consumption. How to reduce the regeneration energy consumption of the carbon capture technology by chemical absorption through various means is a current research problem. Summary of the Invention

[0005] Aiming at the defects of the existing technology, a carbon capture system is provided in the embodiments of the present invention, which can maximize the use of waste heat recovery, realize the desorption of carbon dioxide, and efficiently reduce the regeneration energy consumption of the absorbent.

[0006] The specific technical solution of the embodiment of the present invention is as follows:

[0007] A carbon capture system, the carbon capture system comprising: an absorption tower, a rich and lean liquid heat exchanger, a desorption tower, a rich liquid flow path, a lean liquid flow path, and a reboiler. The absorption tower includes a housing, the top of the housing is provided with a flue gas outlet, the bottom of the housing is provided with a rich liquid outlet, the side wall of the housing is provided with an absorption liquid inlet near the top, and the side wall of the housing is provided with a flue gas inlet near the bottom; the rich and lean liquid heat exchanger includes a first flow path for flowing rich liquid and a second flow path for flowing lean liquid, the first flow path has a first inlet and a first outlet, the second flow path has a second inlet and a second outlet, the rich liquid flow path is used to introduce the rich liquid flowing out of the rich liquid outlet into the first flow path, exchange heat with the lean liquid in the second flow path, and then introduce it into the desorption tower; the desorption tower includes a cylinder body and a heat exchange device arranged in the cylinder body, the top of the cylinder body is provided with a carbon dioxide gas outlet, the side wall of the cylinder body is provided with a rich liquid inlet near the top, the rich liquid inlet is connected to the rich liquid flow path, the bottom of the cylinder body is provided with a lean liquid outlet, the lean liquid outlet is sequentially connected to the reboiler, the heat exchange device, the second flow path, and the absorption liquid inlet through the lean liquid flow path. The lean liquid heated by the reboiler can perform a primary heat exchange with the rich liquid flowing through the heat exchange device, and then perform a secondary heat exchange with the rich liquid in the first flow path when passing through the rich and lean liquid heat exchanger, and then return to the absorption tower.

[0008] In a preferred embodiment, the rich liquid flow path includes a first pipeline and a second pipeline. The first pipeline is connected between the rich liquid outlet and the first inlet, and a rich liquid pump is arranged on the first pipeline; the second pipeline is connected between the first outlet and the rich liquid inlet.

[0009] In a preferred embodiment, the heat exchange device has an opposite inlet end and outlet end. The lean liquid flow path includes a third pipeline, a fourth pipeline, and a fifth pipeline. The third pipeline is connected between the lean liquid outlet and the inlet end, the reboiler is arranged on the third pipeline, the fourth pipeline is connected between the outlet end and the second inlet, a lean liquid pump is arranged on the fourth pipeline, the fifth pipeline is connected between the second outlet and the absorption liquid inlet, and a cooler is arranged on the fifth pipeline.

[0010] In a preferred embodiment, a demister, a liquid distributor, and a packing layer are further arranged in the cylinder body. The demister, the liquid distributor, and the packing layer are located above the heat exchange device and are sequentially arranged at intervals along the height direction.

[0011] In a preferred embodiment, the heat exchange device includes a multi-stage spiral coil pipe, and the multi-stage spiral coil pipes are sequentially arranged at intervals along the height direction of the cylinder body, and the multi-stage spiral coil pipes are arranged in parallel.

[0012] In a preferred embodiment, any one-stage spiral coil pipe of the multi-stage spiral coil pipes includes: a coil pipe body, an inlet pipe for introducing lean liquid into the coil pipe body, an outlet pipe for discharging lean liquid from the coil pipe body, and along the flow direction of the lean liquid, a flow splitting mechanism is arranged upstream of the inlet pipe, and the flow splitting mechanism is used for distributing the lean liquid heated by the reboiler to the corresponding spiral coil pipes, and a flow converging mechanism is arranged downstream of the outlet pipe, and the flow converging mechanism converges the lean liquid that has exchanged heat with the rich liquid and then introduces it into the rich and lean liquid heat exchanger.

[0013] In a preferred embodiment, the carbon capture system further includes a control system and a valve electrically connected to the control system, and the valve is arranged on the inlet pipe for adjusting the flow rate of the lean liquid entering the coil pipe body.

[0014] In a preferred embodiment, the carbon capture system further includes a pressure transmitter, and the pressure transmitter is electrically connected to the control system for monitoring the pressure of the lean liquid flowing into the coil pipe body.

[0015] In a preferred embodiment, the carbon capture system further includes a temperature detector, and the temperature detector is electrically connected to the control system for detecting the temperature of the lean liquid flowing into the coil pipe body.

[0016] In a preferred embodiment, the absorbent is an organic amine absorbent.

[0017] The technical solution of the present invention has the following remarkable beneficial effects:

[0018] In the carbon capture system provided in the embodiment of the present application, during the carbon capture and desorption process, the lean liquid heated by the reboiler enters the heat exchange device to heat the rich liquid flowing through the heat exchange device, effectively utilizing the heat provided by the reboiler, so that very little heat generated by the reboiler is wasted and lost, fully recovering waste heat at the source, reaching the desorption state of the rich liquid (carbon dioxide-rich absorbent), realizing the desorption of carbon dioxide, effectively reducing the regeneration energy consumption of the absorbent, and solving the problem of effectively controlling the regeneration energy consumption of the carbon capture technology.

[0019] Since the lean liquid has undergone the first heat exchange with the rich liquid in the desorption tower when flowing through the heat exchange device for heating in the desorption tower, its temperature has decreased to a certain extent, but it still has a certain amount of heat. In order to make full use of the lean liquid after the first heat exchange, the lean liquid can be made to flow into the lean-rich liquid heat exchanger to preheat the rich liquid before it flows into the desorption tower, thereby further utilizing the heat in the lean liquid, maximizing the waste heat recovery rate, and further reducing the regeneration energy consumption of the absorbent, preferably solving the problem of effectively controlling the regeneration energy consumption of the carbon capture technology.

[0020] Specific embodiments of the present invention are disclosed in detail with reference to the following description and the accompanying drawings, indicating the ways in which the principles of the present invention can be employed. It should be understood that the embodiments of the present invention are not limited thereby in scope. Within the spirit and terms of the appended claims, the embodiments of the present invention include many variations, modifications, and equivalents. Features described and / or illustrated for one embodiment can be used in the same or similar manner in one or more other embodiments, combined with features in other embodiments, or substituted for features in other embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The drawings described herein are for illustrative purposes only and are not intended to limit the scope of the disclosure of the present invention in any way. Additionally, the shapes and proportional dimensions of the various components in the drawings are only schematic and are used to assist in understanding the present invention, rather than specifically limiting the shapes and proportional dimensions of the various components of the present invention. Those skilled in the art can, under the teachings of the present invention, select various possible shapes and proportional dimensions according to specific circumstances to implement the present invention.

[0022] Figure 1 It is a schematic structural diagram of a carbon capture system provided in an embodiment of the present application;

[0023] Figure 2 It is a schematic structural diagram of a desorption tower in a carbon capture system provided in an embodiment of the present application;

[0024] Figure 3 It is a schematic structural diagram of a heat exchange device provided in a desorption tower of a carbon capture system provided in an embodiment of the present application.

[0025] Reference numerals of the present application:

[0026] 2. Absorption tower;

[0027] 20. Shell;

[0028] 21. Flue gas outlet;

[0029] 22. Rich liquid outlet;

[0030] 23. Absorbent inlet;

[0031] 24. Flue gas inlet;

[0032] 4. Rich liquid pump;

[0033] 41. First pipeline;

[0034] 42. Second pipeline;

[0035] 5. Rich and lean liquid heat exchanger;

[0036] 51. First inlet;

[0037] 52. First outlet;

[0038] 53. Second inlet;

[0039] 54. Second outlet;

[0040] 6. Lean liquid pump;

[0041] 63. Third pipeline;

[0042] 64. Fourth pipeline;

[0043] 65. Fifth pipeline;

[0044] 7. Reboiler;

[0045] 8. Desorption tower;

[0046] 80. Cylinder body;

[0047] 81. Heat exchange device;

[0048] 810. Coil body;

[0049] 811. Upper spiral coil;

[0050] 812. Middle spiral coil;

[0051] 813. Lower spiral coil;

[0052] 814. Flow splitting mechanism;

[0053] 815. Flow confluence mechanism;

[0054] 816. Inlet pipeline;

[0055] 817. Outlet pipeline;

[0056] 12. Valve;

[0057] 13. Pressure transmitter;

[0058] 14. Temperature detector;

[0059] 82. Carbon dioxide gas outlet;

[0060] 83. Rich liquid inlet;

[0061] 84. Lean liquid outlet;

[0062] 91. Demister;

[0063] 92. Liquid distributor;

[0064] 93. Packing layer;

[0065] 10. Cooler;

[0066] 11. Condenser. Detailed implementation manners

[0067] The technical solutions of the present invention will be described in detail below in conjunction with the accompanying drawings and specific embodiments. It should be understood that these embodiments are only used to illustrate the present invention and not to limit the scope of the present invention. After reading the present invention, those skilled in the art's various equivalent forms of modification of the present invention all fall within the scope defined by the appended claims of this application.

[0068] It should be noted that when an element is referred to as being "disposed on" another element, it can be directly on the other element or there can also be a middle element. When an element is considered to be "connected" to another element, it can be directly connected to the other element or there may be a middle element at the same time. The terms "vertical", "horizontal", "upper", "lower", "left", "right" and similar expressions used herein are only for the purpose of illustration and do not represent the only implementation manner.

[0069] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by those of ordinary skill in the technical field to which this application belongs. The terms used herein in the specification of this application are only for the purpose of describing specific implementation manners and are not intended to limit this application. The term "and / or" used herein includes any and all combinations of one or more of the related listed items.

[0070] Prior art one:

[0071] In the technology of "a compound carbon dioxide desorption tower", a demister is arranged below the purified gas outlet at the top of the tower body. A first liquid inlet distributor is arranged below the demister. A plurality of packing layers are arranged below the first liquid inlet distributor. An interlayer liquid distributor and a tray are arranged between adjacent packing layers. A second liquid inlet distributor is arranged below the bottom packing layer. A plurality of trays are arranged below the second liquid inlet distributor. A gas-liquid mixing inlet pipe is arranged below the bottom tray. A liquid outlet pipe is arranged at the bottom of the tower kettle. The liquid enters the reboiler through the liquid outlet pipe for heating and desorption. The gas-liquid mixed fluid after desorption enters the tower body through the gas-liquid mixing inlet pipe. The liquid after desorbing carbon dioxide exits the reboiler. When the amount of carbon dioxide produced required by the actual operating conditions is small, the required flow rate of rich amine liquid is small at this time. Only the tray part of the tower body can be used for stripping desorption, and the packing part can be used as a demister, so as to greatly reduce the liquid entrainment of carbon dioxide gas leaving the tower at the top of the tower. It can also overcome the problems of uneven flow and small operating flexibility existing in the packed tower, and at the same time can enhance the adaptability to different performance alkanolamine solutions.

[0072] This compound carbon dioxide desorption tower still adopts the traditional way of heating the absorbent, and uses a reboiler to heat and desorb the regenerated liquid, which increases the investment in equipment in the early stage and causes excessive energy consumption waste, resulting in an increase in the cost of the entire project. At the same time, this desorption tower greatly increases the weight and height of the equipment, and greatly increases the construction cost and operating cost.

[0073] Prior art two:

[0074] In the technology of "a new type of carbon dioxide desorption tower", the desorption tower includes an upper tower and a lower tower connected. The lower tower includes a lower tower packing section and a lower tower water storage section connected. A base is arranged below the lower tower water storage section. A liquid inlet is arranged on the lower tower packing section. The liquid inlets of the upper tower and the lower tower packing section are connected by a pipeline.

[0075] In the above desorption tower, the aqueous solution after desorbing carbon dioxide enters the lower tower through a pipeline, but a part of the aqueous solution will remain in the conical part of the upper tower and will be discharged through the blowdown port, which causes great waste to the recycling use of the aqueous solution. Similarly, there is also the same waste situation at the bottom of the lower tower, which invisibly increases the operation consumption of the project.

[0076] At present, the overall energy consumption of the existing carbon dioxide desorption towers is high due to various reasons.

[0077] The present invention provides a carbon capture system, which can maximize the utilization of waste heat recovery, realize the desorption of carbon dioxide, and efficiently reduce the regeneration energy consumption of the absorbent.

[0078] Please refer to comprehensively Figures 1 to 2, in the embodiments of the specification of the present application, a carbon capture system is provided. The carbon capture system may include: an absorption tower 2, a rich / lean liquid heat exchanger 5, a desorption tower 8, a rich liquid flow path, a lean liquid flow path, and a reboiler 7. The absorption tower 2 includes a housing 20. A flue gas outlet 21 is provided at the top of the housing 20. A rich liquid outlet 22 is provided at the bottom of the housing 20. An absorption liquid inlet 23 is provided at a position near the top on the side wall of the housing 20. A flue gas inlet 24 is provided at a position near the bottom on the side wall of the housing 20. The rich / lean liquid heat exchanger 5 includes a first flow path for flowing rich liquid and a second flow path for flowing lean liquid. The first flow path has a first inlet 51 and a first outlet 52. The second flow path has a second inlet 53 and a second outlet 54. The rich liquid flow path is used to introduce the rich liquid flowing out of the rich liquid outlet 22 into the first flow path, exchange heat with the lean liquid in the second flow path, and then introduce it into the desorption tower 8. The desorption tower 8 includes a cylinder body 80 and a heat exchange device 81 provided in the cylinder body 80. A carbon dioxide gas outlet 82 is provided at the top of the cylinder body 80. A rich liquid inlet 83 is provided at a position near the top on the side wall of the cylinder body 80. The rich liquid inlet 83 is connected to the rich liquid flow path. A lean liquid outlet 84 is provided at the bottom of the cylinder body 80. The lean liquid outlet 84 is sequentially connected to the reboiler 7, the heat exchange device 81, the second flow path, and the absorption liquid inlet 23 through the lean liquid flow path. The lean liquid heated by the reboiler 7 can perform a primary heat exchange with the rich liquid flowing through the heat exchange device 81, and then perform a secondary heat exchange with the rich liquid in the first flow path when passing through the rich / lean liquid heat exchanger 5, and then return to the absorption tower 2.

[0079] In the carbon capture system provided in the embodiments of the present application, during the carbon capture and desorption process, by using the lean liquid heated by the reboiler 7 to enter the heat exchange device 81 and heat the rich liquid flowing through the heat exchange device 81, waste heat recovery is fully utilized at the root, reaching the desorption state of the rich liquid (carbon dioxide-rich absorption liquid), realizing the desorption of carbon dioxide, effectively reducing the regeneration energy consumption of the absorbent, and solving the problem of effectively controlling the regeneration energy consumption of the carbon capture technology.

[0080] Since the lean liquid has undergone a first heat exchange with the rich liquid in the desorption tower 8 when flowing through and heating the heat exchange device 81 in the desorption tower 8, its temperature has dropped to a certain extent, but it still has a certain amount of heat. In order to make full use of the lean liquid after the first heat exchange, the lean liquid can be made to flow into the rich / lean liquid heat exchanger 5 to preheat the rich liquid before flowing into the desorption tower 8, thereby further utilizing the heat in the lean liquid, enabling the waste heat recovery rate to reach the maximum, and further reducing the regeneration energy consumption of the absorbent, preferably solving the problem of effectively controlling the regeneration energy consumption of the carbon capture technology.

[0081] The present application will be described in detail below in conjunction with specific drawings and embodiments.

[0082] In an embodiment of the present application, the carbon capture system may include: an absorption tower 2, a rich / lean liquid heat exchanger 5, a desorption tower 8, a rich liquid flow path, a lean liquid flow path, a reboiler 7, etc.

[0083] The absorption tower 2 is mainly used to remove carbon dioxide from flue gas. The absorption tower 2 may include a housing 20 and a demister 91, a distributor, packing, etc. provided inside the housing 20.

[0084] The top of the housing 20 is provided with a flue gas outlet 21 for discharging the decarbonized clean flue gas; the bottom of the housing 20 is provided with a rich liquid outlet 22, and the rich liquid outlet 22 is used to discharge the absorption liquid rich in carbon dioxide (referred to as rich liquid). A flue gas inlet 24 is provided at a position near the bottom on the side wall of the housing 20, and the flue gas inlet 24 is used to introduce the desulfurized and denitrified flue gas into the absorption tower 2. An absorption liquid inlet 23 is provided at a position near the top on the side wall of the housing 20, and the absorption liquid inlet 23 is used to introduce a carbon dioxide absorbent into the absorption tower 2. In an embodiment of the present application, the carbon dioxide absorbent is exemplified by an organic amine absorption liquid.

[0085] When the carbon dioxide absorbent, i.e., the absorption liquid, is an organic amine absorbent, it has the following advantages:

[0086] Strong absorption capacity: The organic amine molecule contains active groups such as amino groups, which can chemically react with carbon dioxide and have a high absorption capacity for carbon dioxide. For example, monoethanolamine (MEA), diethanolamine (DEA), etc. can absorb a large amount of carbon dioxide under certain conditions to form stable carbamates or bicarbonates and other compounds.

[0087] Fast reaction rate: The reaction rate of organic amine and carbon dioxide is relatively fast, and a high absorption efficiency can be achieved in a short time. Especially for some organic amines with small steric hindrance, their amino groups are easily in contact with carbon dioxide molecules and react, and the capture of carbon dioxide can be quickly realized.

[0088] Good selectivity: In a mixed system containing multiple gases, the organic amine has good selective absorption for carbon dioxide. It can preferentially react with carbon dioxide and has less absorption of other gases such as nitrogen and oxygen, which makes it have high purity and efficiency in the process of carbon dioxide capture.

[0089] The demister 91, the distributor, and the packing may be sequentially arranged along the height direction.

[0090] Among them, the demister 91 can be arranged near the top of the absorption tower 2 to remove the fine droplets carried in the purified flue gas, prevent these droplets from being discharged from the absorption tower 2 with the flue gas, avoid adverse effects such as corrosion and blockage on subsequent equipment, and at the same time reduce the loss of absorbent and improve the absorption efficiency.

[0091] The distributor can be located in the upper part of the absorption tower 2, below the demister 91 and above the packing. The distributor is mainly used to evenly distribute the absorbent on the packing, so that the absorbent can form a uniform liquid film on the surface of the packing, thereby increasing the contact area between the absorbent and the flue gas, improving the absorption efficiency, and ensuring the full progress of the absorption process.

[0092] The packing can be in the middle of the absorption tower 2, below the distributor. The main function of the packing is to provide sufficient contact area and good mass transfer conditions for the gas-liquid two-phase. The flue gas flows through the packing and comes into full contact with the absorbent flowing down from the distributor, and gases such as carbon dioxide are absorbed by the absorbent, thereby realizing the removal of carbon dioxide in the flue gas. The presence of the packing increases the gas-liquid contact time and contact area, making the process of carbon dioxide in the flue gas being absorbed by the carbon dioxide absorbent more efficient.

[0093] During use, the carbon dioxide absorbent enters the shell 20 from the absorbent inlet 23 at the upper part of the absorption tower 2, and sprays down under the action of gravity. The flue gas enters the shell 20 from the flue gas inlet 24 at the bottom of the absorption tower 2 and flows upward in a countercurrent manner. The two come into full contact, and the carbon dioxide in the flue gas is removed by using the carbon dioxide absorbent.

[0094] The rich liquid pump 4 is used to provide driving force for the absorbent coming out of the absorption tower 2 to enter the rich and lean liquid heat exchanger 5. In one embodiment, the rich liquid flow path may include a first pipeline 41 and a second pipeline 42. The first pipeline 41 is connected between the rich liquid outlet 22 and the first inlet 51, and a rich liquid pump 4 is arranged on the first pipeline 41; the second pipeline 42 is connected between the first outlet 52 and the rich liquid inlet 83.

[0095] In this embodiment, the rich liquid pump 4 has opposite inlets and outlets. The inlet of the rich liquid pump 4 is connected to the rich liquid outlet 22 of the absorption tower 2 through the first pipeline 41, and the outlet of the rich liquid pump 4 is connected to the first inlet 51 of the rich and lean liquid heat exchanger 5 through the second pipeline 42. Among them, a valve 12 for controlling the pipeline channel may also be arranged on the first pipeline 41 and / or the second pipeline 42.

[0096] The rich and lean liquid heat exchanger 5 is used to realize the heat exchange between the lean liquid and the rich liquid. Specifically, the specific form of the rich and lean liquid heat exchanger 5 may include any one of the following: plate heat exchanger, shell and tube heat exchanger, etc.

[0097] The rich and lean liquid heat exchanger 5 has a first flow channel for the circulation of rich liquid and a second flow channel for the circulation of lean liquid. The first flow channel has a first inlet 51 and a first outlet 52, and the second flow channel has a second inlet 53 and a second outlet 54. Among them, under the action of the rich liquid pump 4, the rich liquid flowing out of the absorption tower 2 flows into the first flow channel through the first inlet 51 and exchanges heat with the lean liquid in the second flow channel. Subsequently, the heat-exchanged rich liquid is introduced into the desorption tower 8 through the second pipeline 42.

[0098] The desorption tower 8 is used for desorbing carbon dioxide in the rich liquid flowing into it. Specifically, the desorption tower 8 may include a hollow cylindrical body 80, and a demister 91, a liquid distributor 92, a packing layer 93 and a heat exchange device 81 provided in the cylindrical body 80. Among them, in the height direction, the demister 91, the liquid distributor 92, the packing layer 93 and the heat exchange device 81 may be sequentially arranged at intervals from top to bottom.

[0099] The top of the cylindrical body 80 is provided with a carbon dioxide gas outlet 82 for discharging the desorbed carbon dioxide. A rich liquid inlet 83 is provided at a position near the top of the side wall of the cylindrical body 80. The rich liquid inlet 83 is communicated with the third pipeline 63 and is used for introducing rich liquid into the cylindrical body 80. The bottom of the cylindrical body 80 is provided with a lean liquid outlet 84, and the lean liquid outlet 84 is used for discharging the lean liquid obtained after the rich liquid is desorbed from the cylindrical body 80.

[0100] In an embodiment, the heat exchange device 81 has opposite inlet and outlet ends. The lean liquid flow channel includes a third pipeline 63, a fourth pipeline 64 and a fifth pipeline 65. The third pipeline 63 is connected between the lean liquid outlet 84 and the inlet end. The reboiler 7 is provided on the third pipeline 63. The fourth pipeline 64 is connected between the outlet end and the second inlet 53. A lean liquid pump 6 is provided on the fourth pipeline 64. The fifth pipeline 65 is connected between the second outlet 54 and the absorption liquid inlet 23. A cooler 10 is provided on the fifth pipeline 65.

[0101] The demister 91 is used for removing atomized rich liquid, water vapor, etc. in the upward flowing carbon dioxide. Further, downstream of the carbon dioxide gas outlet 82, a cooling device, such as a condenser 11, may be provided. The condenser 11 is used for cooling the discharged carbon dioxide so that the discharged temperature is controlled within a predetermined temperature range. In addition, the condenser 11 can further condense the rich liquid and water vapor that may not be removed by the demister 91 in the carbon dioxide to prevent them from being discharged following the carbon dioxide gas.

[0102] The liquid distributor 92 is used to uniformly initially distribute or redistribute the rich liquid entering the desorption tower 8, improving the effect of the packing layer 93. Specifically, the structure of the liquid distributor 92 can be a trough-type distributor. When the liquid distributor 92 is a trough-type distributor, it can include one or more rectangular or circular distribution troughs. The liquid first enters the distribution trough and then is uniformly distributed into the tower through small holes, overflow weirs, etc. on the trough bottom or trough walls. The trough-type distributor can be divided into first-stage trough-type, second-stage trough-type, etc. The multi-stage trough-type distributor can improve the uniformity of liquid distribution. Overall, the trough-type distributor has a large operating flexibility, can adapt to large changes in liquid flow rate, and has good liquid distribution uniformity. Of course, the structure of the liquid distributor 92 can also be in other forms. For example, a tube-type distributor, a spray-head type distributor, a disk-type distributor, or a combined distributor obtained by combining the above multiple distributors. For example, a trough-type distributor can be combined with a tube-type distributor. First, a preliminary distribution is carried out through the trough-type distributor, and then a fine distribution is carried out through the tube-type distributor to improve the uniformity and reliability of liquid distribution. Of course, the specific form of the liquid distributor 92 can also be flexibly designed in combination according to different process requirements and conditions inside the tower.

[0103] The main function of the packing layer 93 is to increase the contact surface between the gas and liquid phases and accelerate the mass transfer efficiency. The rich liquid flows downward in a film shape on the surface of the packing, and mass transfer and heat transfer occur between the gas and liquid phases.

[0104] The packing layer 93 can include packing and a limiting mechanism for limiting the packing. The limiting mechanism can be fixed on the inner side wall of the cylinder 80.

[0105] The desorption tower 8 belongs to a differential contact type gas-liquid mass transfer device. The rich liquid entering the cylinder 80 flows downward in a film shape on the surface of the packing, and the gas is in a continuous phase and flows upward reversely with the liquid, and mass transfer and heat transfer occur between the gas and liquid phases. The component concentrations and temperatures of the two phases change continuously along the tower height.

[0106] The desorption process is generally an endothermic reaction. Increasing the temperature is beneficial to the reaction proceeding in the desorption direction, causing carbon dioxide to escape from the absorption liquid. For example, a heat exchange device 81 can be used to heat the rich liquid to a certain temperature range, such as 80°C - 120°C, to promote the desorption of carbon dioxide.

[0107] Please refer to Figure 3 , the heat exchange device 81 is used to heat the lean liquid in the desorption tower 8 to ensure that the lean liquid has enough temperature to exchange heat with the rich liquid and raise the temperature of the rich liquid. And the process of absorbing carbon dioxide is usually a reversible chemical reaction process. When the rich liquid is heated, the solubility of carbon dioxide in the absorption liquid decreases, and the carbon dioxide molecules originally dissolved in the absorption liquid obtain enough energy to escape from the liquid phase into the gas phase, thus realizing the desorption of carbon dioxide, that is, achieving the purpose of promoting the desorption of the rich liquid.

[0108] Specifically, the heat exchange device 81 can adopt a multi-stage embedded heat exchange system. Specifically, the structure of the heat exchange device 81 can be in the form of a multi-stage spiral coil. Of course, the heat exchange device 81 can also adopt forms such as multi-stage coils of other types, such as the form of a serpentine coil; or, the heat exchange device 81 can also have other structures. In this embodiment, the heat exchange device 81 being a multi-stage spiral coil is taken as an example for illustration.

[0109] The heat exchange device 81 can include a coil body 810, an inlet pipe 816 for introducing a fluid (such as high-temperature lean liquid) into the coil body 810, and an outlet pipe 817 for discharging the fluid (the lean liquid after heat exchange with rich liquid) from the coil body 810. An installation opening for installing the coil body 810 can be provided on the side wall of the cylinder 80, and the coil body 810 can be hermetically fixed on the cylinder 80 through the installation opening. Of course, the specific way of installing the heat exchange device 81 in the cylinder 80 is not limited to the above example, and the present application does not make specific limitations here.

[0110] In the flow direction of the lean liquid, a flow splitting mechanism 814 is provided upstream of the inlet pipe 816. The flow splitting mechanism 814 is used to distribute the lean liquid heated by the reboiler 7 to the corresponding spiral coils. A flow confluence mechanism 815 is provided downstream of the outlet pipe 817. The flow confluence mechanism 815 converges the lean liquid after heat exchange with the rich liquid and then introduces it into the lean-rich liquid heat exchanger 5.

[0111] A third pipe is provided between the lean liquid outlet 84 and the inlet pipe 816, and the reboiler 7 is arranged on the third pipe for heating the lean liquid flowing through the reboiler 7.

[0112] The lean liquid flowing out from the bottom of the desorption tower 8 is a liquid with a relatively low carbon dioxide content after the desorption process. By setting the reboiler 7 to heat it, a small amount of remaining carbon dioxide and other gases in the lean liquid can be further desorbed, thereby improving the quality of the lean liquid and making it more suitable for recycling back to the absorption tower 2 to continue absorbing carbon dioxide, which is beneficial to improving the efficiency and stability of the entire carbon dioxide absorption-desorption system.

[0113] The desorption process is an endothermic process, and sufficient heat needs to be provided to promote the desorption of carbon dioxide and other gases in the rich liquid. The reboiler 7 heats the lean liquid, and the heated lean liquid flows into the heat exchange device 81 to provide heat for the desorption process. The lean liquid exchanges heat with the rich liquid to provide the required energy for the desorption of carbon dioxide in the rich liquid and maintain the continuous progress of the desorption reaction in the desorption tower 8.

[0114] Overall, in the carbon capture and desorption process provided by the embodiments of the present application, the lean liquid heated by the reboiler 7 enters the heat exchange device 81, and heats the rich liquid flowing through the heat exchange device 81, effectively utilizing the heat provided by the reboiler 7, so that very little waste and loss of the heat generated by the reboiler 7 occurs, fully recovering waste heat at the source, reaching the desorption state of the rich liquid (carbon dioxide-rich absorbent), realizing the desorption of carbon dioxide, effectively reducing the regeneration energy consumption of the absorbent, and solving the problem of effectively controlling the regeneration energy consumption of the carbon capture technology.

[0115] In this embodiment, the temperature and flow rate of the lean liquid can also be controlled by the reboiler 7, and the temperature and liquid level at the bottom of the desorption tower 8 can be adjusted, thereby optimizing the operating conditions of the desorption tower 8. Stable bottom temperature and liquid level help to ensure the gas-liquid balance and mass transfer effect in the desorption tower 8, making the desorption process more stable and efficient, and reducing problems such as incomplete desorption of carbon dioxide or unstable quality of the lean liquid caused by operation fluctuations.

[0116] In this embodiment, the outlet pipe 817 of the heat exchange device 81 can flow through the rich-lean heat exchanger through the fourth pipeline 64 and then return to the absorption tower 2 as the absorbent through the fifth pipeline 65, thereby realizing the recycling of the absorbent. Among them, one end of the fourth pipeline 64 is connected to the outlet pipe 817, and the other end can be connected to the second inlet 53 of the second flow channel of the rich-lean liquid heat exchanger 5. Since the lean liquid has undergone the first heat exchange with the rich liquid in the desorption tower 8 when flowing through the heat exchange device 81 in the desorption tower 8, its temperature has decreased to a certain extent, but it still has a certain amount of heat. In order to make full use of the lean liquid after the first heat exchange, the lean liquid can be made to flow into the rich-lean liquid heat exchanger 5 to preheat the rich liquid before flowing into the desorption tower 8, thereby further utilizing the heat in the lean liquid, maximizing the waste heat recovery rate, and further reducing the regeneration energy consumption of the absorbent, preferably solving the problem of effectively controlling the regeneration energy consumption of the carbon capture technology.

[0117] In addition, in order for the lean liquid (absorbent) returned to the absorption tower 2 to reach the target reaction temperature, a cooler 10 can be provided on the fifth pipeline 65 to cool the absorbent using the cooler 10 to make it reach the target reaction temperature, thereby facilitating the better reaction of the absorbent with carbon dioxide. For different selected absorbents, the optimal temperature for reacting with carbon dioxide is also different. Taking the absorbent as an organic amine absorbent as an example, the temperature of the absorbent can be reduced to room temperature using the condenser 11, which is beneficial to the efficient chemical reaction of the organic amine absorbent with carbon dioxide.

[0118] Among them, the coil body 810 of the heat exchange device 81 can be formed by bending a metal pipe with corrosion resistance and better heat exchange performance into a spiral shape, so as to ensure that the coil body 810 has a longer length, and further ensure that the coil body 810 has a larger heat exchange area. Among them, a predetermined gap is formed between two adjacent pipes of the coil body 810 in the radial direction, and the predetermined gap is used for the flow of rich liquid. Specifically, the predetermined gap can be about 5 cm. The dimensions such as the diameter and pitch (predetermined gap) of the coil can be determined according to factors such as the size, processing capacity, and heating requirements of the desorption tower 8, and this application does not make a unique numerical limitation here.

[0119] In the desorption tower 8, the spiral coils can be divided into multiple stages, and the multiple-stage spiral coils can be arranged in layers along the height direction of the desorption tower 8. Each stage of the coil can be connected by pipes to form a complete heat exchange device 81. Specifically, when the spiral coil includes three stages, it can be divided into an upper spiral coil 811, a middle spiral coil 812, and a lower spiral coil 813, and the upper spiral coil 811, the middle spiral coil 812, and the lower spiral coil 813 are sequentially arranged in the cylinder body 80 along the height direction.

[0120] The arrangement structure of the multi-stage spiral coils of the heat exchange device 81 can enable the heating medium to be evenly distributed in the tower, so as to realize the uniform heating of the rich liquid. The shape of the spiral coil can make the heating medium continuously change direction during the flow process, enhance the fluid disturbance, improve the heat transfer effect, reduce the heating dead angle, ensure that the rich liquid can be fully and evenly heated on the entire tower cross-section, and is beneficial to the desorption of carbon dioxide.

[0121] The arrangement of the multi-stage spiral coils of the heat exchange device 81 increases the contact area and contact time between the heating medium (lean liquid) and the rich liquid. The heating medium flows in the coil, and the rich liquid flows in the tower, and the two exchange heat through the pipe wall. The multi-stage coils enable the rich liquid to exchange heat with the heating medium at different temperatures multiple times during the descending process, gradually increasing the temperature and improving the desorption efficiency. At the same time, the structure of the spiral coil also increases the fluid flow rate. According to the heat transfer principle, the increase in flow rate can increase the convective heat transfer coefficient and further improve the heat transfer efficiency.

[0122] The structure of the spiral coil is relatively compact, and a large heat exchange area can be arranged in the limited tower space. The multi-stage spiral coils can be reasonably designed according to the shape and size of the tower, make full use of the space in the tower, reduce the volume occupied by the heat exchange device 81, improve the space utilization rate of the desorption tower 8, and make the entire desorption system more compact and efficient.

[0123] In addition, independent inlet pipes 816 and outlet pipes 817 can be provided for each stage of the coil, which is convenient for controlling and regulating the heating process. By adjusting parameters such as the flow rate and temperature of the heating medium of each stage of the coil, precise heating control can be carried out according to the rich liquid temperature and carbon dioxide desorption conditions at different heights in the desorption tower 8. For example, in the upper part of the tower, since the carbon dioxide concentration gradually decreases, a lower heating temperature may be required; while in the lower part of the tower, the carbon dioxide concentration in the rich liquid is higher and a higher heating temperature is needed. The adjustment of multiple-stage coils can meet the heating requirements at different heights and optimize the desorption process.

[0124] A valve 12 can be installed on the inlet pipe 816, and this valve 12 is used to control the flow rate and pressure of the fluid introduced into the coil. In addition, a filter can also be provided on the inlet pipe 816, and this filter can prevent impurities in the fluid from entering the coil, affecting the heat exchange effect or blocking the pipe.

[0125] Specifically, the carbon capture system further includes a control system. This control system can be electrically connected to devices such as the valve 12 that need to be electrically controlled, so as to control the working states and working parameters of these devices.

[0126] In the direction of fluid flow, a pressure transmitter 13 electrically connected to the control system can be provided on the inlet pipe 816 downstream of the valve 12. This pressure transmitter 13 can be used to monitor the pressure of the fluid flowing into the coil in real time and convert it into an electrical signal, so as to facilitate the control system to precisely control and regulate the fluid pressure.

[0127] Using this pressure transmitter 13 can measure the pressure value of the fluid (mainly lean liquid in a vapor state) in the inlet pipe 816 in real time and accurately, so that the control system can accurately understand the current fluid pressure condition. This is very important for ensuring the stability of the heating process in the desorption tower 8, because the stability of the steam pressure directly affects the heating effect and the desorption efficiency of carbon dioxide.

[0128] In addition, the cooperation of this pressure transmitter 13 and the control system can also serve the purpose of safety protection and optimized control.

[0129] For example: when the pressure of the fluid flowing through the inlet pipe 816 exceeds or is lower than the set safety range, the pressure transmitter 13 can send out a signal in time. This signal can trigger an alarm device to remind the operator to take corresponding measures to avoid safety accidents such as pipeline rupture and equipment damage caused by too high steam pressure, or to avoid affecting the desorption effect due to too low pressure, ensuring the safe and stable operation of the desorption tower 8.

[0130] The pressure transmitter 13 transmits the measured pressure signal to the control system, and the control system can automatically adjust the opening degree of the valve 12 according to the preset pressure value. Through this closed-loop control method, the steam pressure is always maintained within the optimal working range, thereby optimizing the heating process of the desorption tower 8, improving the energy utilization efficiency, and reducing the operating cost.

[0131] Specifically, the pressure sensor inside the pressure transmitter 13 can use principles such as strain gauges, capacitive, or piezoelectric to sense the fluid pressure. Taking the strain gauge type pressure sensor as an example, when the fluid pressure acts on the elastic element (such as a diaphragm) of the sensor, the elastic element deforms, and the strain gauge attached to its surface also generates strain, resulting in a change in the resistance value of the strain gauge.

[0132] The pressure sensor converts the sensed pressure change into a change in physical quantities such as resistance, capacitance, or charge, and then the internal circuit of the pressure transmitter 13 can convert these physical quantity changes into standard electrical signals, such as a 4-20 mA current signal or a 0-10 V voltage signal.

[0133] The converted electrical signal is transmitted to the control system by wired (such as cables) or wireless means. In the control system, the control system compares the received pressure signal with the preset pressure value, and then issues a control command to achieve the adjustment of the opening degree of the valve 12 in the inlet pipeline 816 to maintain the stability of the fluid pressure. In addition, the control system can also convert the electrical signal into the corresponding pressure value for display, facilitating the operator to intuitively observe the change in fluid pressure.

[0134] Specifically, on this inlet pipeline, along the fluid flow direction, a temperature detection element 14 can also be provided on the inlet pipeline downstream of the pressure transmitter 13. Considering that the fluid will exchange heat to a certain extent when flowing through the inlet pipeline 816, resulting in a certain temperature fluctuation. When the temperature detection element 14 is located downstream of the pressure transmitter 13, it is relatively closer to the inlet of the coil body 810 of the heat exchange device 81, making the detected temperature closer to the fluid temperature in the heat exchange device 81.

[0135] Among them, the specific form of the temperature detection element 14 can be in the form of a thermocouple. Of course, the form of the temperature detection element 14 can also be other forms, and this application does not make specific limitations here. In the implementation mode of this application, the temperature detection element 14 is mainly illustrated by taking the form of a thermocouple as an example.

[0136] The temperature detection component 14 is used to accurately measure the temperature of the fluid flowing into the heat exchange device 81, providing temperature parameters for the heating control of the desorption tower 8 to ensure the stability and efficiency of the desorption process. The temperature detection component 14 can be electrically connected to the control system. The temperature signal obtained through the temperature detection component 14 is used to control the temperature of the lower part of the cylinder 80 where the heat exchange device 81 is arranged to be between 110 degrees Celsius and 120 degrees Celsius.

[0137] For different desorption stages and rich liquid compositions, fluids at different temperatures are required to achieve the best desorption effect. The thermocouple can measure the temperature of the steam in real time and accurately. After receiving the temperature signal of the thermocouple, the control system can compare it with the preset temperature to determine whether the current fluid meets the temperature requirements of the desorption process.

[0138] Since temperature is one of the important parameters affecting the desorption process. The temperature signal measured by the thermocouple can be transmitted to the control system as feedback information. The control system compares the preset temperature value with the actual measured value and automatically adjusts the opening of the valve 12 on the inlet pipe 816 or the parameters of other relevant heat exchange devices 81 to keep the temperature of the fluid within a suitable range, thereby optimizing the heating process of the desorption tower 8 and improving the desorption efficiency of carbon dioxide.

[0139] Since overheated or overcooled fluids may damage the desorption tower 8 and related equipment. The thermocouple can detect abnormal changes in the steam temperature in a timely manner. When the temperature exceeds the safe range, the control system will issue an alarm and take corresponding protective measures, such as closing the valve 12 on the inlet pipe 816, or it can also start a standby cooling device, etc., to prevent the equipment from being damaged due to high temperature, the pipeline from bursting due to excessive thermal stress, or problems such as poor desorption effect and freezing of rich liquid due to low temperature, ensuring the safe and stable operation of the desorption system.

[0140] In addition, by analyzing the temperature data measured by the thermocouple and combining other operating parameters of the desorption tower 8, such as pressure, flow rate, etc., the operating state of the system can also be evaluated and fault diagnosed. For example, if the fluid temperature suddenly drops, it may mean that there is a fault in the fluid supply system, such as a fault in the reboiler 7, pipeline blockage or leakage of the valve 12; if the temperature fluctuates greatly, it may indicate problems with the control system or unstable operation of the heating device. By discovering and solving these potential problems in a timely manner, the desorption process can be prevented from being seriously affected, and the reliability and operating efficiency of the system can be improved.

[0141] In one embodiment, the heat exchange device 81 in the desorption tower 8 can be a multi-stage embedded heat exchange system. For example, when the multi-stage embedded heat exchange system is a three-stage embedded heat exchange system and the heat exchange system takes multi-stage coils as an example, it can include: an upper spiral coil 811, a middle spiral coil 812, and a lower spiral coil 813. Embedding the multi-stage embedded heat exchange system in the desorption tower 8 can increase the contact area between the rich liquid (absorption liquid rich in carbon dioxide) and the high-temperature lean liquid, thereby increasing the heating rate of the rich liquid.

[0142] During use, the flue gas after desulfurization and denitrification enters the absorption tower 2 through the flue. The flue gas enters from the flue gas inlet 24 at the bottom of the absorption tower 2, and the flue gas after removing carbon dioxide is discharged from the flue gas outlet 21 at the top of the absorption tower 2. The absorption liquid rich in carbon dioxide flows out from the rich liquid outlet 22 at the bottom of the absorption tower 2, exchanges heat with the lean liquid coming out of the desorption tower 8 through the rich-lean liquid heat exchanger 5, and then enters the desorption tower 8. The heat exchange device 81 is provided inside the desorption tower 8, and efficient desorption of carbon dioxide can be achieved according to the capacity of the absorbed rich liquid and the desorption rate. The lean liquid flowing out from the lean liquid outlet 84 at the bottom of the desorption tower 8 is heated up by the reboiler 7, undergoes multi-stage heat exchange with the rich liquid in the desorption tower 8, and then returns to the absorption tower 2 through the rich-lean liquid heat exchanger.

[0143] In a specific application scenario, the process of the carbon capture system provided in the embodiment of the present application during carbon dioxide desorption is as follows:

[0144] The temperature of the flue gas after desulfurization and denitrification is approximately between 80°C and 120°C. It is cooled to room temperature through the scrubber and then enters the absorption tower 2 through the flue, countercurrently contacting the absorption liquid from the upper part of the absorption tower 2. The absorption liquid after absorbing carbon dioxide exchanges heat through the rich-lean liquid heat exchanger 5 and then enters the upper part of the desorption tower 8, where it evenly spills. The multi-stage heat exchange device 81 embedded in the desorption tower 8 is in full contact with the spilled rich liquid, achieving the effect of heating and desorbing the absorption liquid. The system controls the number of heat exchange devices 81 participating in heat exchange through the desorption rate to ensure the carbon dioxide removal rate.

[0145] The lean liquid coming out of the multi-stage heat exchange device 81 of the desorption tower 8 converges in the pipeline, passes through the lean liquid pump 6, and enters the rich-lean liquid heat exchanger 5 to exchange heat with the absorption liquid rich in carbon dioxide coming out of the absorption tower 2. Heat recovery is carried out again. The lean liquid after heat exchange enters the top of the absorption tower 2 to absorb carbon dioxide again.

[0146] After the first heating, the rich liquid (absorption liquid rich in carbon dioxide) coming out of the rich-lean liquid heat exchanger 5 enters the top of the desorption tower 8, flows from top to bottom, passes through the multi-stage heat exchange device 81, and is heated up again to achieve the purpose of carbon dioxide desorption.

[0147] It should be noted that in the description of this application, the terms "first", "second", etc. are only used for descriptive purposes and to distinguish similar objects. There is no sequence between them, nor can it be understood as indicating or implying relative importance. In addition, in the description of this application, unless otherwise specified, the meaning of "a plurality of" is two or more than two.

[0148] The above various embodiments in this specification are all described in a progressive manner. For the same or similar parts between the various embodiments, reference can be made to each other, and each embodiment focuses on the differences from other embodiments.

[0149] The above are only several embodiments of the present invention. Although the disclosed embodiments of the present invention are as above, the content is only an embodiment adopted for the convenience of understanding the present invention and is not used to limit the present invention. Any person skilled in the art in the technical field to which the present invention pertains, without departing from the spirit and scope disclosed by the present invention, can make any modifications and changes in the form and details of the embodiments, but the scope of patent protection of the present invention shall still be subject to the scope defined by the appended claims.

Claims

1. A carbon capture system, characterized in that, The carbon capture system includes: an absorption tower, a rich / lean liquid heat exchanger, a desorption tower, a rich liquid flow path, a lean liquid flow path, and a reboiler. The absorption tower includes a housing. A flue gas outlet is provided at the top of the housing, a rich liquid outlet is provided at the bottom of the housing, an absorption liquid inlet is provided at a position near the top on the side wall of the housing, and a flue gas inlet is provided at a position near the bottom on the side wall of the housing. The rich / lean liquid heat exchanger includes a first flow path for flowing rich liquid and a second flow path for flowing lean liquid. The first flow path has a first inlet and a first outlet, and the second flow path has a second inlet and a second outlet. The rich liquid flow path is used to introduce the rich liquid flowing out of the rich liquid outlet into the first flow path, exchange heat with the lean liquid in the second flow path, and then introduce it into the desorption tower. The desorption tower includes a cylinder body and a heat exchange device arranged in the cylinder body. A carbon dioxide gas outlet is provided at the top of the cylinder body, a rich liquid inlet is provided at a position near the top on the side wall of the cylinder body, and the rich liquid inlet is connected to the rich liquid flow path. A lean liquid outlet is provided at the bottom of the cylinder body. The lean liquid outlet is sequentially connected to the reboiler, the heat exchange device, the second flow path, and the absorption liquid inlet through the lean liquid flow path. The lean liquid heated by the reboiler can perform a primary heat exchange with the rich liquid flowing through the heat exchange device, and then perform a secondary heat exchange with the rich liquid in the first flow path when passing through the rich / lean liquid heat exchanger, and then return to the absorption tower.

2. The carbon capture system according to claim 1, characterized in that, The rich liquid flow path includes a first pipeline and a second pipeline. The first pipeline is connected between the rich liquid outlet and the first inlet, and a rich liquid pump is provided on the first pipeline. The second pipeline is connected between the first outlet and the rich liquid inlet.

3. The carbon capture system according to claim 1, characterized in that, The heat exchange device has an opposite inlet end and outlet end. The lean liquid flow path includes a third pipeline, a fourth pipeline, and a fifth pipeline. The third pipeline is connected between the lean liquid outlet and the inlet end, and the reboiler is provided on the third pipeline. The fourth pipeline is connected between the outlet end and the second inlet, and a lean liquid pump is provided on the fourth pipeline. The fifth pipeline is connected between the second outlet and the absorption liquid inlet, and a cooler is provided on the fifth pipeline.

4. The carbon capture system according to claim 1, wherein An eliminator, a liquid distributor, and a packing layer are further arranged in the cylinder body. The eliminator, the liquid distributor, and the packing layer are located above the heat exchange device and are sequentially arranged at intervals along the height direction.

5. The carbon capture system according to claim 1, characterized in that, The heat exchange device includes a multi-stage spiral coil, and the multi-stage spiral coils are sequentially arranged at intervals along the height direction of the cylinder body, and the multi-stage spiral coils are arranged in parallel.

6. The carbon capture system according to claim 5, wherein Any stage of the multi-stage spiral coil includes: a coil body, an inlet pipe for introducing lean liquid into the coil body, an outlet pipe for discharging lean liquid from the coil body. Along the flow direction of the lean liquid, a flow splitting mechanism is provided upstream of the inlet pipe, and the flow splitting mechanism is used to distribute the lean liquid heated by the reboiler to the corresponding spiral coil. A flow confluence mechanism is provided downstream of the outlet pipe, and the flow confluence mechanism converges the lean liquid that has exchanged heat with the rich liquid and then introduces it into the lean-rich liquid heat exchanger.

7. The carbon capture system according to claim 6, wherein The carbon capture system further includes a control system and a valve electrically connected to the control system. The valve is provided on the inlet pipe and is used to adjust the flow rate of the lean liquid entering the coil body.

8. The carbon capture system according to claim 7, wherein The carbon capture system further includes a pressure transmitter electrically connected to the control system and used to monitor the pressure of the lean liquid flowing into the coil body.

9. The carbon capture system according to claim 7, wherein The carbon capture system further includes a temperature detector electrically connected to the control system and used to detect the temperature of the lean liquid flowing into the coil body.

10. The carbon capture system according to claim 1, wherein The absorbent is an organic amine absorbent.

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