Carbon dioxide capture system and control method thereof

Abstract

The present invention relates to the field of environmental protection technology, and discloses a carbon dioxide capture system and a control method thereof, in which the bottom of an absorption tower is divided into a first chamber and a second chamber, the absorption liquid first flows into the first chamber, and then flows from the top of the second chamber to the second chamber, and the second chamber is used to phase the absorption liquid; a light phase outlet and a heavy phase outlet are provided on the absorption tower shell, the light phase outlet is connected to the inlet of an absorbent mixing unit through a first delivery pipeline, and the light phase outlet is connected to the first inlet of a heat exchange unit through a second delivery pipeline; the heavy phase outlet is connected to the inlet of the absorbent mixing unit through a third delivery pipeline, and the heavy phase outlet is connected to the first inlet of the heat exchange unit through a fourth delivery pipeline; the second outlet of the heat exchange unit is connected to the inlet of the absorbent mixing unit, and the outlet of the absorbent mixing unit is connected to the absorbent inlet of the absorption tower. The carbon dioxide capture system of this scheme can take into account both single-phase and multiple phase separation situations, and has strong flexibility.

Description

Technical Field

[0001] The present invention relates to the field of environmental protection technology, and in particular to a carbon dioxide capture system and a control method for the carbon dioxide capture system. Background Art

[0002] In order to reduce carbon dioxide emissions and alleviate the greenhouse effect, various carbon dioxide capture technologies have emerged. Among them, carbon dioxide capture technology based on phase change absorbent is one of the more commonly used carbon dioxide capture technologies. The principle of this carbon dioxide capture technology is that after absorbing carbon dioxide, the phase change absorbent forms two immiscible liquid phases, namely the lean CO2 phase and the rich CO2 phase (the concentration of carbon dioxide in the lean CO2 phase is lower than that in the rich CO2 phase), separates the lean CO2 phase and the rich CO2 phase, and transports the rich CO2 phase to the regeneration tower for carbon dioxide desorption.

[0003] In the case of different phase change absorbent formulas, such as different phase separation agents in the phase change absorbent, there are usually two phase separation situations, namely: the CO2-lean phase is the heavy phase and the CO2-rich phase is the light phase; or, the CO2-lean phase is the light phase and the CO2-rich phase is the heavy phase. Under the same phase change absorbent formula, the above two phase separation situations may also occur due to factors such as flue gas flow rate, carbon dioxide concentration in flue gas, impurities in flue gas, and absorption temperature. Moreover, the actual operation process may continuously switch between these two phase separation situations.

[0004] However, the existing carbon dioxide capture system is usually designed for only one phase separation situation, and cannot take into account multiple phase separation situations, let alone adapt to the changing phase separation situation. For example, a carbon dioxide capture system designed for a CO2-lean phase as a heavy phase and a CO2-rich phase as a light phase usually fixedly transports the light phase and the CO2-rich phase to a regeneration tower for carbon dioxide desorption. When the phase separation situation changes, for example, the CO2-lean phase becomes a light phase and the CO2-rich phase becomes a heavy phase, the carbon dioxide capture system cannot transport the heavy phase and the CO2-rich phase to the regeneration tower for carbon dioxide desorption. Summary of the invention

[0005] The purpose of the present invention is to overcome the problem that the carbon dioxide capture system in the prior art cannot take into account multiple phase separation situations, and to provide a carbon dioxide capture system and a control method thereof.

[0006] In order to achieve the above-mentioned object, the first aspect of the present invention provides a carbon dioxide capture system, the carbon dioxide capture system comprising an absorption tower, a first carbon dioxide detection device, a second carbon dioxide detection device, a first delivery pipeline, a second delivery pipeline, a third delivery pipeline, a fourth delivery pipeline, an absorbent mixing unit, a heat exchange unit and a regeneration tower;

[0007] The bottom of the absorption tower is divided into a first chamber and a second chamber by a partition component. The absorption liquid first flows into the first chamber, and then overflows from the first chamber to the second chamber through the top of the second chamber. The second chamber is used to separate the incoming absorption liquid into phases.

[0008] The absorption tower shell corresponding to the second chamber is provided with a light phase outlet for outputting a light phase solution and a heavy phase outlet for outputting a heavy phase solution, and the density of the light phase solution is less than the density of the heavy phase solution; the first carbon dioxide detection device is used to detect parameters related to the carbon dioxide content in the light phase solution, and the second carbon dioxide detection device is used to detect parameters related to the carbon dioxide content in the heavy phase solution;

[0009] The light phase outlet is communicated with the inlet of the absorbent mixing unit through the first delivery pipeline, and the light phase outlet is communicated with the first inlet of the heat exchange unit through the second delivery pipeline; the heavy phase outlet is communicated with the inlet of the absorbent mixing unit through the third delivery pipeline, and the heavy phase outlet is communicated with the first inlet of the heat exchange unit through the fourth delivery pipeline;

[0010] The first outlet of the heat exchange unit is connected to the inlet of the regeneration tower, and the second inlet of the heat exchange unit is connected to the bottom of the regeneration tower; the second outlet of the heat exchange unit is connected to the inlet of the absorbent mixing unit, and the outlet of the absorbent mixing unit is connected to the absorbent inlet of the absorption tower.

[0011] In the embodiment of the present application, a first outlet is provided at the bottom of the first chamber, and the carbon dioxide capture system further includes a fifth delivery pipeline;

[0012] The first outlet of the first chamber is communicated with the first inlet of the heat exchange unit through the fifth delivery pipeline.

[0013] In the embodiment of the present application, a second outlet is further provided at the bottom of the first chamber, a third outlet is further provided at the bottom of the second chamber, and the carbon dioxide capture system further comprises a sixth transport pipeline;

[0014] The second outlet of the first chamber is communicated with the third outlet of the second chamber through the sixth delivery pipeline.

[0015] In the embodiment of the present application, an interface detection device is also provided on the absorption tower shell corresponding to the second chamber.

[0016] In an embodiment of the present application, the absorption tower includes a packing section and a bottom section, and the diameter of the bottom section is larger than the diameter of the packing section.

[0017] In an embodiment of the present application, the partition assembly includes a first baffle and a second baffle;

[0018] The first baffle extends from the bottom of the tower kettle of the absorption tower to the packing section of the absorption tower, and is used to separate the tower kettle of the absorption tower into a first chamber and a second chamber;

[0019] The second baffle extends from the absorption tower shell corresponding to the top of the second chamber to the top of the first chamber, and is used to cover the top of the second chamber;

[0020] A flow channel for absorption liquid is formed between the first baffle plate and the second baffle plate.

[0021] In the embodiment of the present application, a phase separation device is also provided in the second chamber.

[0022] In an embodiment of the present application, the heat exchange unit includes a first heat exchanger and a second heat exchanger;

[0023] The light phase outlet is communicated with the first inlet of the first heat exchanger through the second delivery pipeline, the heavy phase outlet is communicated with the first inlet of the first heat exchanger through the fourth delivery pipeline, and the first outlet of the first chamber is communicated with the first inlet of the first heat exchanger and the first inlet of the second heat exchanger through the fifth delivery pipeline;

[0024] The first outlet of the first heat exchanger and the first outlet of the second heat exchanger are both connected to the inlet of the regeneration tower, and the second inlet of the first heat exchanger and the second inlet of the second heat exchanger are both connected to the kettle of the regeneration tower;

[0025] The second outlet of the first heat exchanger and the second outlet of the second heat exchanger are both in communication with the inlet of the absorbent mixing unit.

[0026] In an embodiment of the present application, the absorbent mixing unit includes a first mixer and a second mixer;

[0027] The light phase outlet is communicated with the inlet of the first mixer through the first delivery pipeline, and the heavy phase outlet is communicated with the inlet of the second mixer through the third delivery pipeline;

[0028] The second outlet of the first heat exchanger is communicated with both the inlet of the first mixer and the inlet of the second mixer, and the second outlet of the second heat exchanger is communicated with both the inlet of the first mixer and the inlet of the second mixer.

[0029] In the embodiment of the present application, a first flow meter and a first flow regulating valve are provided on the second delivery pipeline;

[0030] The fourth delivery pipeline is provided with a second flow meter and a second flow regulating valve.

[0031] In the embodiment of the present application, a liquid level detection device is provided on the absorption tower shell corresponding to the first chamber, and a third flow meter and a third flow regulating valve are provided on the fifth delivery pipeline.

[0032] A second aspect of the present invention provides a control method for the above-mentioned carbon dioxide capture system, the control method comprising:

[0033] In response to the carbon dioxide content in the light phase solution being less than the carbon dioxide content in the heavy phase solution, the first transmission pipeline is opened, the second transmission pipeline is closed, and the light phase solution is controlled to be transmitted to the absorbent mixing unit via the first transmission pipeline; and the third transmission pipeline is closed, the fourth transmission pipeline is opened, and the heavy phase solution is controlled to be transmitted to the heat exchange unit via the fourth transmission pipeline;

[0034] In response to the carbon dioxide content in the light phase solution being greater than the carbon dioxide content in the heavy phase solution, the first transport pipeline is closed, the second transport pipeline is opened, and the light phase solution is controlled to be transported to the heat exchange unit via the second transport pipeline; and the third transport pipeline is opened, the fourth transport pipeline is closed, and the heavy phase solution is controlled to be transported to the absorbent mixing unit via the third transport pipeline.

[0035] A third aspect of the present invention provides a control method for the above-mentioned carbon dioxide capture system, wherein a first outlet is provided at the bottom of the first chamber, the carbon dioxide capture system further comprises a fifth delivery pipeline, and the first outlet of the first chamber is connected to the first inlet of the heat exchange unit through the fifth delivery pipeline, and the control method comprises:

[0036] In response to the carbon dioxide content in the light phase solution being less than the carbon dioxide content in the heavy phase solution, the first transmission pipeline is opened, the second transmission pipeline is closed, and the light phase solution is controlled to be transmitted to the absorbent mixing unit via the first transmission pipeline; and the third transmission pipeline is closed, the fourth transmission pipeline is opened, and the heavy phase solution is controlled to be transmitted to the heat exchange unit via the fourth transmission pipeline;

[0037] In response to the carbon dioxide content in the light phase solution being greater than the carbon dioxide content in the heavy phase solution, the first transmission pipeline is closed, the second transmission pipeline is opened, and the light phase solution is controlled to be transmitted to the heat exchange unit via the second transmission pipeline; and the third transmission pipeline is opened, the fourth transmission pipeline is closed, and the heavy phase solution is controlled to be transmitted to the absorbent mixing unit via the third transmission pipeline;

[0038] In response to the absorbent being a single-phase absorbent, the first delivery pipeline, the second delivery pipeline, the third delivery pipeline, and the fourth delivery pipeline are closed, the fifth delivery pipeline is opened, and the solution in the first chamber is controlled to be delivered to the heat exchange unit.

[0039] In an embodiment of the present application, the heat exchange unit includes a first heat exchanger and a second heat exchanger, and the absorbent mixing unit includes a first mixer and a second mixer;

[0040] The controlling the light phase solution to be transported to the absorbent mixing unit via the first transport pipeline comprises:

[0041] Controlling the light phase solution to be transported to the first mixer via the first transport pipeline;

[0042] The controlling the heavy phase solution to be transported to the heat exchange unit via the fourth transport pipeline comprises:

[0043] Controlling the heavy phase solution to be transported to the first heat exchanger via the fourth transport pipeline;

[0044] The controlling the light phase solution to be transported to the heat exchange unit via the second transport pipeline comprises:

[0045] Controlling the light phase solution to be transported to the first heat exchanger via the second transport pipeline;

[0046] The controlling the heavy phase solution to be transported to the absorbent mixing unit via the third transport pipeline comprises:

[0047] Controlling the heavy phase solution to be transported to the second mixer via the third transport pipeline;

[0048] The controlling the solution in the first chamber to be transported to the heat exchange unit comprises:

[0049] The solution in the first chamber is controlled to be transported to the first heat exchanger and the second heat exchanger.

[0050] A fourth aspect of the present invention provides a control method for the above-mentioned carbon dioxide capture system, wherein a first outlet and a second outlet are provided at the bottom of the first chamber, and a third outlet is provided at the bottom of the second chamber, and the carbon dioxide capture system further comprises a fifth delivery pipeline and a sixth delivery pipeline; the first outlet of the first chamber is communicated with the first inlet of the heat exchange unit through the fifth delivery pipeline, and the second outlet of the first chamber is communicated with the third outlet of the second chamber through the sixth delivery pipeline, and the control method comprises:

[0051] In response to the carbon dioxide content in the light phase solution being less than the carbon dioxide content in the heavy phase solution, the first transmission pipeline is opened, the second transmission pipeline is closed, and the light phase solution is controlled to be transmitted to the absorbent mixing unit via the first transmission pipeline; and the third transmission pipeline is closed, the fourth transmission pipeline is opened, and the heavy phase solution is controlled to be transmitted to the heat exchange unit via the fourth transmission pipeline;

[0052] In response to the carbon dioxide content in the light phase solution being greater than the carbon dioxide content in the heavy phase solution, the first transmission pipeline is closed, the second transmission pipeline is opened, and the light phase solution is controlled to be transmitted to the heat exchange unit via the second transmission pipeline; and the third transmission pipeline is opened, the fourth transmission pipeline is closed, and the heavy phase solution is controlled to be transmitted to the absorbent mixing unit via the third transmission pipeline;

[0053] In response to the absorbent being a single-phase absorbent, closing the first delivery pipeline, the second delivery pipeline, the third delivery pipeline, and the fourth delivery pipeline, opening the fifth delivery pipeline, and controlling the solution in the first chamber to be delivered to the heat exchange unit;

[0054] In response to the single-phase absorption liquid in the second chamber, the first delivery pipeline, the second delivery pipeline, the third delivery pipeline and the fourth delivery pipeline are closed, the fifth delivery pipeline and the sixth delivery pipeline are opened, and the solution in the bottom of the absorption tower is controlled to be delivered to the heat exchange unit.

[0055] In an embodiment of the present application, the heat exchange unit includes a first heat exchanger and a second heat exchanger, and the absorbent mixing unit includes a first mixer and a second mixer;

[0056] The controlling the light phase solution to be transported to the absorbent mixing unit via the first transport pipeline comprises:

[0057] Controlling the light phase solution to be transported to the first mixer via the first transport pipeline;

[0058] The controlling the heavy phase solution to be transported to the heat exchange unit via the fourth transport pipeline comprises:

[0059] Controlling the heavy phase solution to be transported to the first heat exchanger via the fourth transport pipeline;

[0060] The controlling the light phase solution to be transported to the heat exchange unit via the second transport pipeline comprises:

[0061] Controlling the light phase solution to be transported to the first heat exchanger via the second transport pipeline;

[0062] The controlling the heavy phase solution to be transported to the absorbent mixing unit via the third transport pipeline comprises:

[0063] Controlling the heavy phase solution to be transported to the second mixer via the third transport pipeline;

[0064] The controlling the solution in the first chamber to be transported to the heat exchange unit comprises:

[0065] Controlling the solution in the first chamber to be transported to the first heat exchanger and the second heat exchanger;

[0066] The controlling the solution in the bottom of the absorption tower to be transported to the heat exchange unit comprises:

[0067] The solution in the bottom of the absorption tower is controlled to be transported to the first heat exchanger and the second heat exchanger.

[0068] According to the above technical scheme, the carbon dioxide capture system includes an absorption tower, a first carbon dioxide detection device, a second carbon dioxide detection device, a first transmission pipeline, a second transmission pipeline, a third transmission pipeline, a fourth transmission pipeline, an absorbent mixing unit, a heat exchange unit and a regeneration tower; the tower kettle of the absorption tower is divided into a first chamber and a second chamber by a partition component, and the absorption liquid first flows into the first chamber, and then overflows from the first chamber to the second chamber through the top of the second chamber, and the second chamber is used to phase-separate the inflowing absorption liquid; a light phase outlet for outputting a light phase solution and a heavy phase outlet for outputting a heavy phase solution are provided on the absorption tower shell corresponding to the second chamber, and the density of the light phase solution is less than the density of the heavy phase solution; the first carbon dioxide detection device is used to detect the carbon dioxide in the light phase solution. Parameters related to carbon dioxide content, the second carbon dioxide detection device is used to detect parameters related to carbon dioxide content in the heavy phase solution; the light phase outlet is connected to the inlet of the absorbent mixing unit through the first delivery pipeline, and the light phase outlet is connected to the first inlet of the heat exchange unit through the second delivery pipeline; the heavy phase outlet is connected to the inlet of the absorbent mixing unit through the third delivery pipeline, and the heavy phase outlet is connected to the first inlet of the heat exchange unit through the fourth delivery pipeline; the first outlet of the heat exchange unit is connected to the inlet of the regeneration tower, and the second inlet of the heat exchange unit is connected to the tower kettle of the regeneration tower; the second outlet of the heat exchange unit is connected to the inlet of the absorbent mixing unit, and the outlet of the absorbent mixing unit is connected to the absorbent inlet of the absorption tower. The carbon dioxide capture system provided in the embodiment of the present application is applicable whether the lean CO2 phase is the heavy phase and the rich CO2 phase is the light phase, or the lean CO2 phase is the light phase and the rich CO2 phase is the heavy phase. That is, the carbon dioxide capture system provided in the above embodiment of the present application can take into account a variety of phase separation situations and has strong flexibility. When the phase separation situation changes, there is no need to replace equipment or perform additional design, which greatly reduces the equipment investment cost of the carbon dioxide capture system.

[0069] Other features and advantages of the embodiments of the present application will be described in detail in the subsequent specific implementation section. BRIEF DESCRIPTION OF THE DRAWINGS

[0070] The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the following specific implementations, they are used to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. In the accompanying drawings:

[0071] Figure 1 A schematic diagram of the structure of a carbon dioxide capture system according to an embodiment of the present application is shown;

[0072] Figure 2The schematic diagram of the structure of an absorption tower according to an embodiment of the present application is shown;

[0073] Figure 3 A schematic diagram of the structure of another carbon dioxide capture system according to an embodiment of the present application is shown;

[0074] Figure 4 A schematic diagram of control logic of mode 1 according to an embodiment of the present application is shown;

[0075] Figure 5 A schematic diagram of control logic of mode 2 according to an embodiment of the present application is shown;

[0076] Figure 6 A schematic diagram of control logic of mode 3 according to an embodiment of the present application is shown;

[0077] Figure 7 A control logic diagram of mode 4 according to an embodiment of the present application is schematically shown.

[0078] Description of Reference Numerals

[0079] 100—CO2 capture system; 101—absorption tower; 1011—first chamber; 1012—second chamber; 1013—first baffle; 1014—second baffle; 1015—phase separation device; 1016—interface detection device; 1017—window; 1018—interface controller; 1019—liquid level detection device; 102—first CO2 detection device; 103—second CO2 detection device; 104—first delivery pipeline; 10 5—second delivery pipeline; 106—third delivery pipeline; 107—fourth delivery pipeline; 108—absorbent mixing unit; 1081—first mixer; 1082—second mixer; 109—heat exchange unit; 1091—first heat exchanger; 1092—second heat exchanger; 110—regeneration tower; 111—light phase pipeline; 112—heavy phase pipeline; 113—light phase three-way valve; 114—heavy phase three-way valve; 115—light phase pump; 116—heavy phase pump; 1 17—lean liquid cooler; 118—first flow meter; 119—first flow regulating valve; 120—second flow meter; 121—second flow regulating valve; 122—light phase flow controller; 123—heavy phase flow controller; 124—fifth delivery pipeline; 125—single-phase pump; 126—third flow meter; 127—third flow regulating valve; 128—liquid level controller; 129—single-phase flow controller; 130—sixth delivery pipeline; 131—on-off valve; 132—rich liquid main pipeline; 133—rich liquid three-way valve; 134—first rich liquid branch pipeline; 135—second rich liquid branch pipeline; 136—first lean liquid main pipeline; 137—first lean liquid three-way valve; 138—first lean liquid branch pipeline; 139—second lean liquid branch pipeline; 140—lean liquid pump; 141—second lean liquid main pipeline; 142—second lean liquid three-way valve; 143—third lean liquid branch pipeline; 144—fourth lean liquid branch pipeline; 145—absorbent flowmeter. DETAILED DESCRIPTION

[0080] In order to make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be clearly and completely described below in conjunction with the drawings in the embodiments of the present application. It should be understood that the specific implementation methods described herein are only used to illustrate and explain the embodiments of the present application, and are not used to limit the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of this application.

[0081] If there are descriptions involving "first", "second", etc. in the embodiments of the present application, the descriptions of "first", "second", etc. are only used for descriptive purposes and cannot be understood as indicating or suggesting their relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In addition, the technical solutions between the various embodiments can be combined with each other, but they must be based on the ability of ordinary technicians in the field to implement them. When the combination of technical solutions is contradictory or cannot be implemented, it should be deemed that such a combination of technical solutions does not exist and is not within the scope of protection required by this application.

[0082] As described in the background technology, in order to reduce carbon dioxide emissions to alleviate the greenhouse effect, various carbon dioxide capture technologies have emerged. Among them, carbon dioxide capture technology based on phase change absorbent is one of the more commonly used carbon dioxide capture technologies. The principle of this carbon dioxide capture technology is: after absorbing carbon dioxide, the phase change absorbent forms two immiscible liquid phases, namely, a lean CO2 phase and a rich CO2 phase (the concentration of carbon dioxide in the lean CO2 phase is lower than the concentration of carbon dioxide in the rich CO2 phase), separates the lean CO2 phase and the rich CO2 phase, and transports the rich CO2 phase to the regeneration tower for carbon dioxide desorption. In the case of different phase change absorbent formulations, such as different phase separation agents in the phase change absorbent, two phase separation situations usually occur, namely: the lean CO2 phase is a heavy phase and the rich CO2 phase is a light phase; or, the lean CO2 phase is a light phase and the rich CO2 phase is a heavy phase. Under the same phase change absorbent formulation, the above two phase separation situations may also occur due to factors such as flue gas flow rate, carbon dioxide concentration in flue gas, impurities in flue gas, and absorption temperature. Moreover, affected by various factors, the actual operation process may switch continuously between these two phase separation conditions. However, the existing carbon dioxide capture system is usually designed for only one phase separation condition, and cannot take into account multiple phase separation conditions, let alone adapt to the ever-changing phase separation conditions. For example, a carbon dioxide capture system designed for a lean CO2 phase as a heavy phase and a rich CO2 phase as a light phase usually transports the light phase and the rich CO2 phase to a regeneration tower for carbon dioxide desorption. When the phase separation condition changes, for example, the lean CO2 phase becomes a light phase and the rich CO2 phase becomes a heavy phase, the carbon dioxide capture system cannot transport the heavy phase and the rich CO2 phase to the regeneration tower for carbon dioxide desorption.

[0083] In view of this, in one embodiment of the present application, a carbon dioxide capture system is provided, such as Figure 1As shown, the carbon dioxide capture system 100 may include an absorption tower 101, a first carbon dioxide detection device 102, a second carbon dioxide detection device 103, a first delivery pipeline 104, a second delivery pipeline 105, a third delivery pipeline 106, a fourth delivery pipeline 107, an absorbent mixing unit 108, a heat exchange unit 109 and a regeneration tower 110; the tower kettle of the absorption tower 101 is divided into a first chamber 1011 and a second chamber 1012 by a partition component, and the absorption liquid first flows into the first chamber 1011, and then overflows from the first chamber 1011 to the second chamber 1012 through the top of the second chamber 1012, and the second chamber 1012 is used to phase-separate the inflowing absorption liquid; a light phase outlet A for outputting a light phase solution and a heavy phase outlet B for outputting a heavy phase solution are provided on the absorption tower shell corresponding to the second chamber 1012, and the density of the light phase solution is less than the density of the heavy phase solution; the first carbon dioxide detection device 102 is used to detect The parameters related to the carbon dioxide content in the light phase solution, the second carbon dioxide detection device 103 is used to detect the parameters related to the carbon dioxide content in the heavy phase solution; the light phase outlet A is connected to the inlet of the absorbent mixing unit 108 through the first conveying pipeline 104, and the light phase outlet A is connected to the first inlet of the heat exchange unit 109 through the second conveying pipeline 105; the heavy phase outlet B is connected to the inlet of the absorbent mixing unit 108 through the third conveying pipeline 106, and the heavy phase outlet B is connected to the first inlet of the heat exchange unit 109 through the fourth conveying pipeline 107; the first outlet of the heat exchange unit 109 is connected to the inlet of the regeneration tower 110, and the second inlet of the heat exchange unit 109 is connected to the tower kettle of the regeneration tower 110; the second outlet of the heat exchange unit 109 is connected to the inlet of the absorbent mixing unit 108, and the outlet of the absorbent mixing unit 108 is connected to the absorbent inlet Z of the absorption tower 101.

[0084] The absorption tower 101 can absorb carbon dioxide in the carbon dioxide-containing gas X by using an absorbent. In the absorption tower 101, the absorbent flows from top to bottom, and the carbon dioxide-containing gas X flows from bottom to top. The absorbent and the carbon dioxide-containing gas X are in reverse contact, thereby achieving the absorption of carbon dioxide. The tail gas Y after the carbon dioxide is removed is discharged from the top of the absorption tower 101. The absorbent solution that absorbs carbon dioxide can be referred to as an absorbent solution, that is, the absorbent solution that subsequently flows into the first chamber 1011 and the second chamber 1012 is specifically an absorbent solution that absorbs carbon dioxide.

[0085] Since the bottom of the absorption tower 101 is divided into a first chamber 1011 and a second chamber 1012, there may be a situation where only one of the chambers is used to hold the absorption liquid. Therefore, in order to ensure that when only one chamber is used to hold the absorption liquid, the chamber can still meet the solution holding capacity requirements, in one embodiment, the absorption tower 101 includes a packing section and a bottom section, and the diameter of the bottom section is larger than the diameter of the packing section; wherein the packing section can provide a place for gas-liquid contact, and the absorption reaction of carbon dioxide occurs. In this way, the capacity of each chamber in the bottom of the tower can be increased, thereby meeting the solution holding capacity requirements of a single chamber.

[0086] In the embodiment of the present application, in order to ensure that the absorption liquid can first flow into the first chamber 1011, and then overflow from the first chamber 1011 to the second chamber 1012 through the top of the second chamber 1012, the partition assembly may include a first baffle 1013 and a second baffle 1014; the first baffle 1013 extends from the bottom of the tower kettle of the absorption tower 101 to the packing section of the absorption tower 101, and is used to separate the tower kettle of the absorption tower 101 into the first chamber 1011 and the second chamber 1012; the second baffle 1014 extends from the absorption tower 101 shell corresponding to the top of the second chamber 1012 to the top of the first chamber 1011, and is used to cover the top of the second chamber 1012; the first baffle 1013 and the second baffle 1014 form a flow channel for the absorption liquid. That is, the absorption liquid can overflow to the second chamber 1012 through the flow channel formed between the first baffle 1013 and the second baffle 1014, as shown in FIG. Figure 2 Indicated by the arrow.

[0087] In a specific implementation, the second baffle 1014 may further include an inclined portion and a vertical portion connected. The inclined portion has a downwardly inclined angle and extends to the top of the first chamber 1011. On the one hand, it can cover the top of the second chamber 1012, and on the other hand, it can guide the absorption liquid to the first chamber 1011, so that the absorption liquid can fall into the first chamber 1011 smoothly and quickly. The vertical portion is arranged in the first chamber 1011. On the one hand, it can form a flow channel for the absorption liquid with the first baffle 1013, and on the other hand, it can ensure that the absorption liquid first flows into the first chamber 1011 and then overflows into the second chamber 1012.

[0088] In the embodiment of the present application, when the absorbent is a phase-change absorbent and the absorption liquid that absorbs carbon dioxide forms two immiscible CO2-lean phases and CO2-rich phases, the second chamber 1012 can be used to separate the incoming absorption liquid. In a specific implementation, a phase separation device 1015 can be provided in the second chamber 1012. By providing the phase separation device 1015 in the second chamber 1012, the separation of the light phase and the heavy phase in the absorption liquid can be promoted and the separation effect can be improved. Among them, the phase separation device 1015 can be any device that can separate the absorption liquid into phases, and the phase separation device 1015 can separate the absorption liquid into phases based on the physical properties of the absorption liquid or the chemical properties of the absorption liquid.

[0089] In order to ensure that what is output from the heavy phase outlet B is a heavy phase solution rather than a light phase solution, the heavy phase outlet B may be disposed at the bottom of the second chamber 1012 , for example, may be disposed on the lower head of the absorption tower 101 .

[0090] In order to ensure that what is output from the light phase outlet A is a light phase solution, rather than a heavy phase solution, the light phase outlet A may be set at a position higher than the highest two-phase interface in the second chamber 1012 (i.e., the highest position of the interface between the light phase solution and the heavy phase solution). The highest two-phase interface may be calculated based on the physical parameters such as density, viscosity, and surface tension of the light phase solution and the heavy phase solution and the geometric structure parameters of the phase separation device 1015. The highest two-phase interface may also be regarded as a high alarm interface of the two-phase interface.

[0091] Taking into account that the operating state and the phase change absorbent formula may change, resulting in changes in the highest two-phase interface, in order to ensure that the light phase solution can be smoothly output under various operating states and various phase change absorbent formulas, in actual applications, multiple light phase outlets A can be set, and each light phase outlet A is above the corresponding highest two-phase interface.

[0092] When multiple light phase outlets A are provided, each light phase outlet A is connected to the inlet of the absorbent mixing unit 108 through the first delivery pipeline 104 , and each light phase outlet A is connected to the first inlet of the heat exchange unit 109 through the second delivery pipeline 105 .

[0093] In the embodiment of the present application, in order to further simplify the pipeline design and save costs, the carbon dioxide capture system 100 provided in the embodiment of the present application may also include a light phase pipeline 111 and a heavy phase pipeline 112; the light phase outlet A is connected to the inlet of the absorbent mixing unit 108 through the light phase pipeline 111 and the first delivery pipeline 104 in sequence, and the light phase outlet A is connected to the first inlet of the heat exchange unit 109 through the light phase pipeline 111 and the second delivery pipeline 105 in sequence; the heavy phase outlet B is connected to the inlet of the absorbent mixing unit 108 through the heavy phase pipeline 112 and the third delivery pipeline 106 in sequence, and the heavy phase outlet B is connected to the first inlet of the heat exchange unit 109 through the heavy phase pipeline 112 and the fourth delivery pipeline 107 in sequence.

[0094] That is, after the light phase solution flows out from the light phase outlet A, it first enters the light phase pipeline 111, and after reaching the pipeline branch, it enters the first delivery pipeline 104 or the second delivery pipeline 105. Similarly, after the heavy phase solution flows out from the heavy phase outlet B, it first enters the heavy phase pipeline 112, and after reaching the pipeline branch, it enters the third delivery pipeline 106 or the fourth delivery pipeline 107.

[0095] To simplify the control of the system, a light phase three-way valve 113 may be provided at the outlet of the light phase pipeline 111, i.e., at the branch of the pipeline, to connect the light phase pipeline 111, the first delivery pipeline 104, and the second delivery pipeline 105. Similarly, a heavy phase three-way valve 114 may be provided at the outlet of the heavy phase pipeline 112, i.e., at the branch of the pipeline, to connect the heavy phase pipeline 112, the third delivery pipeline 106, and the fourth delivery pipeline 107.

[0096] Furthermore, in order to be able to draw out the light phase solution from the light phase outlet A and the heavy phase solution from the heavy phase outlet B, a light phase pump 115 may be provided on the light phase pipeline 111 and a heavy phase pump 116 may be provided on the heavy phase pipeline 112 .

[0097] In an embodiment of the present application, the first carbon dioxide detection device 102 can be used to detect parameters related to the carbon dioxide content in the light phase solution in real time, and the second carbon dioxide detection device 103 can be used to detect parameters related to the carbon dioxide content in the heavy phase solution in real time. Among them, parameters related to the carbon dioxide content may include parameters such as pH, conductivity, chromatography, infrared spectrum, Raman spectrum, etc. that can reflect the carbon dioxide content (the content can be either concentration or mass content). That is, after obtaining such parameters, the carbon dioxide content can be obtained directly or through relevant calculations. It can be understood that the first carbon dioxide detection device 102 and the second carbon dioxide detection device 103 can be instruments corresponding to the above-mentioned various parameters.

[0098] In practical applications, the first carbon dioxide detection device 102 detects parameters related to the carbon dioxide content in the light phase solution, which can be detected after the light phase solution is output from the second chamber 1012, or before the light phase solution is output from the second chamber 1012. In the case where the first carbon dioxide detection device 102 detects the light phase solution output from the second chamber 1012, a detection port can be opened on the light phase pipeline 111, and the first carbon dioxide detection device 102 can be connected to the detection port, and the light phase solution is detected through the detection port. In the case where the first carbon dioxide detection device 102 detects the light phase solution in the second chamber 1012, a light phase detection port can be opened on the shell of the absorption tower 101 corresponding to the second chamber 1012, and the first carbon dioxide detection device 102 can be connected to the light phase detection port, and the light phase solution is detected through the light phase detection port. Among them, in order to ensure that the detection object of the first carbon dioxide detection device 102 is a light phase solution, not a heavy phase solution, the light phase detection port opened on the shell of the absorption tower 101 can be located above the highest two-phase interface.

[0099] Similarly, the second carbon dioxide detection device 103 detects parameters related to the carbon dioxide content in the heavy phase solution, which can be detected after the heavy phase solution is output from the second chamber 1012, or before the heavy phase solution is output from the second chamber 1012. In the case where the second carbon dioxide detection device 103 detects the heavy phase solution output from the second chamber 1012, a detection port can be opened on the heavy phase pipeline 112, and the second carbon dioxide detection device 103 can be connected to the detection port, and the heavy phase solution is detected through the detection port. In the case where the second carbon dioxide detection device 103 detects the heavy phase solution in the second chamber 1012, a heavy phase detection port can be opened on the shell of the absorption tower 101 corresponding to the second chamber 1012, and the second carbon dioxide detection device 103 can be connected to the heavy phase detection port, and the heavy phase solution is detected through the heavy phase detection port. In order to ensure that the detection object of the second carbon dioxide detection device 103 is the heavy phase solution, not the light phase solution, the heavy phase detection port opened on the shell of the absorption tower 101 can be located below the lowest two-phase interface (i.e., the lowest position of the interface between the light phase solution and the heavy phase solution). The lowest two-phase interface can be calculated based on the physical parameters such as density, viscosity, surface tension of the light phase solution and the heavy phase solution and the geometric structure parameters of the phase separation device 1015. The lowest two-phase interface can also be regarded as a low alarm interface of the two-phase interface.

[0100] In the embodiment of the present application, the absorbent mixing unit 108 can be used to collect and mix the CO2-lean phase (the light phase or heavy phase output from the absorption tower 101) and the desorbed lean liquid to obtain the absorbent, and then further transport the absorbent to the absorption tower 101 to continue to participate in the reaction of absorbing carbon dioxide. The heat exchange unit 109 can be used to collect the CO2-rich phase (the light phase or heavy phase output from the absorption tower 101), and at the same time to draw out the high-temperature lean liquid after desorbing carbon dioxide from the tower kettle of the regeneration tower 110, and the CO2-rich phase and the high-temperature lean liquid are heat exchanged in the heat exchange unit 109. The CO2-rich phase after heat exchange is further input into the regeneration tower 110 for carbon dioxide desorption, and the lean liquid after heat exchange is further input into the absorbent mixing unit 108. Among them, the regeneration tower 110 is a tower containing a number of fillers and tower plates and other tower internals, which is heated by the reboiler 1101 to desorb carbon dioxide, and the carbon dioxide desorbed at the top of the regeneration tower 110 continues to enter the subsequent process section.

[0101] Then, based on the functions of the absorbent mixing unit 108 and the heat exchange unit 109, it can be understood that:

[0102] When the phase separation result of the second chamber 1012 is that the CO2-lean phase is the light phase and the CO2-rich phase is the heavy phase (i.e., the light phase solution output from the light phase outlet A is the CO2-lean phase, and the heavy phase solution output from the heavy phase outlet B is the CO2-rich phase), the light phase solution output from the light phase outlet A can be transported to the absorbent mixing unit 108 through the light phase pipeline 111 and the first transport pipeline 104. At the same time, the heavy phase solution output from the heavy phase outlet B can be transported to the heat exchange unit 109 through the heavy phase pipeline 112 and the fourth transport pipeline 107. In the heat exchange unit 109, the heavy phase solution is heat exchanged with the high-temperature lean liquid drawn from the tower kettle of the regeneration tower 110. The heavy phase solution after the heat exchange is further input into the regeneration tower 110 for carbon dioxide desorption, and the lean liquid whose temperature is reduced after the heat exchange is further transported to the absorbent mixing unit 108. The absorbent mixing unit 108 mixes the CO2-lean phase collected from the light phase outlet A with the lean liquid collected from the heat exchange unit 109, and then transports them to the absorption tower 101 to continue participating in the reaction of absorbing carbon dioxide.

[0103] When the phase separation result of the second chamber 1012 is that the CO2-lean phase is the heavy phase and the CO2-rich phase is the light phase (that is, the light phase solution output from the light phase outlet A is the CO2-rich phase, and the heavy phase solution output from the heavy phase outlet B is the CO2-lean phase), the light phase solution output from the light phase outlet A can be transported to the heat exchange unit 109 through the light phase pipeline 111 and the second transport pipeline 105. In the heat exchange unit 109, the light phase solution is heat exchanged with the high-temperature lean liquid drawn from the bottom of the regeneration tower 110. The light phase solution after heat exchange is further input into the regeneration tower 110 for carbon dioxide desorption, and the lean liquid with a lowered temperature after heat exchange is further transported to the absorbent mixing unit 108. At the same time, the heavy phase solution output from the heavy phase outlet B can be transported to the absorbent mixing unit 108 through the heavy phase pipeline 112 and the third transport pipeline 106. The absorbent mixing unit 108 mixes the CO2-lean phase collected from the heavy phase outlet B with the lean liquid collected from the heat exchange unit 109, and then transports them to the absorption tower 101 to continue participating in the reaction of absorbing carbon dioxide.

[0104] In specific implementation, in order to further improve the absorption effect of the absorbent transported from the heat exchange unit 109 to the absorption tower 101, the carbon dioxide capture system 100 provided in the embodiment of the present application may further include a lean liquid cooler 117, and the lean liquid cooler 117 is arranged on the pipeline connecting the outlet of the heat exchange unit 109 and the absorbent inlet Z of the absorption tower 101. For the convenience of subsequent control, an absorbent flowmeter 145 may also be arranged on the pipeline connecting the outlet of the heat exchange unit 109 and the absorbent inlet Z of the absorption tower 101.

[0105] In practical applications, in order to control the actual two-phase interface in the second chamber 1012 and the flow rate of the solution transported to the heat exchange unit 109 so that the system can operate stably for a long time, in one embodiment, an interface detection device 1016 is also provided on the shell of the absorption tower 101 corresponding to the second chamber 1012, and a first flow meter 118 and a first flow regulating valve 119 are provided on the second transport pipeline 105; a second flow meter 120 and a second flow regulating valve 121 are provided on the fourth transport pipeline 107; the interface detection device 1016 is used to detect the position of the two-phase interface between the light phase solution and the heavy phase solution in the second chamber 1012.

[0106] Among them, the interface detection device 1016 can detect the position of the two-phase interface of the light phase solution and the heavy phase solution in the second chamber 1012, and can also detect the liquid level of the solution in the second chamber 1012. The interface detection device 1016 can specifically be an interface meter. During specific implementation, the shell of the absorption tower 101 corresponding to the second chamber 1012 can be provided with an upper port C of the interface meter and a lower port D of the interface meter, and the upper port C of the interface meter and the lower port D of the interface meter are connected to the interface meter. During actual setting, the upper port C of the interface meter can be located above the highest two-phase interface, and the lower port D of the interface meter can be located below the lowest two-phase interface. At the same time, a window 1017 can also be provided on the shell of the absorption tower 101 corresponding to the second chamber 1012 to assist in observing the phase separation in the second chamber 1012.

[0107] The first flow meter 118 can be used to detect the flow rate of the light phase solution in the second delivery pipeline 105 in real time, and the first flow regulating valve 119 can be used to adjust the flow rate of the light phase solution in the second delivery pipeline 105. The second flow meter 120 can be used to detect the flow rate of the heavy phase solution in the fourth delivery pipeline 107 in real time, and the second flow regulating valve 121 can be used to adjust the flow rate of the heavy phase solution in the fourth delivery pipeline 107.

[0108] Furthermore, in order to realize automatic control of the two-phase interface and automatic control of the flow rate of the solution transported to the heat exchange unit 109, an interface controller 1018 is also provided on the shell of the absorption tower 101 corresponding to the second chamber 1012, a light phase flow controller 122 is also provided on the second transport pipeline 105, and a heavy phase flow controller 123 is also provided on the fourth transport pipeline 107.

[0109] It can be understood that the carbon dioxide capture system 100 provided in the above embodiment of the present application is applicable whether the lean CO2 phase is a heavy phase and the rich CO2 phase is a light phase, or the lean CO2 phase is a light phase and the rich CO2 phase is a heavy phase. That is, the carbon dioxide capture system 100 provided in the above embodiment of the present application can take into account a variety of phase separation situations and has strong flexibility. When the phase separation situation changes, there is no need to replace the equipment or perform additional design, which greatly reduces the equipment investment cost of the carbon dioxide capture system.

[0110] Considering that the carbon dioxide capture technology based on single-phase absorbent is also one of the more commonly used carbon dioxide capture technologies. The principle of this carbon dioxide capture technology is: the single-phase absorbent obtains a single-phase absorption liquid (also called rich liquid) after absorbing carbon dioxide, and the single-phase absorption liquid is transported to the regeneration tower for carbon dioxide desorption. It can be seen that there are great differences between the principles of carbon dioxide capture technology based on single-phase absorbent and carbon dioxide capture technology based on phase change absorbent. The former does not undergo phase separation, while the latter does. Based on this difference, the existing carbon dioxide capture system is either designed for carbon dioxide capture technology based on single-phase absorbent or designed for carbon dioxide capture technology based on phase change absorbent, and it is impossible to take into account both carbon dioxide capture technologies.

[0111] In order to enable the carbon dioxide capture system 100 provided in the embodiment of the present application to further take into account the carbon dioxide capture technology based on a single-phase absorbent, that is, the single-phase absorbent can be used as the absorbent of the absorption tower 101, in one embodiment, a first outlet E is opened at the bottom of the first chamber 1011, and the carbon dioxide capture system 100 also includes a fifth delivery pipeline 124; the first outlet E of the first chamber 1011 is connected to the first inlet of the heat exchange unit 109 through the fifth delivery pipeline 124.

[0112] Thus, when a single-phase absorbent is used as the absorbent of the absorption tower 101, the single-phase absorption liquid that absorbs carbon dioxide in the first chamber 1011 can be directly transported to the heat exchange unit 109 through the fifth delivery pipeline 124. In the heat exchange unit 109, the single-phase absorption liquid is heat exchanged with the high-temperature lean liquid drawn from the bottom of the regeneration tower 110. The single-phase absorption liquid after heat exchange is further input into the regeneration tower 110 for carbon dioxide desorption, and the lean liquid with a lowered temperature after heat exchange is further transported to the absorbent mixing unit 108. It can be understood that when a single-phase absorbent is used as the absorbent of the absorption tower 101, the single-phase absorption liquid formed after absorbing carbon dioxide stays in the first chamber 1011 and does not overflow into the second chamber 1012. In order to smoothly draw out the single-phase absorption liquid from the first outlet E, a single-phase pump 125 can also be provided on the fifth delivery pipeline 124.

[0113] In actual applications, in order to control the liquid level in the first chamber 1011 and the flow rate of the solution delivered to the heat exchange unit 109 so that the system can operate stably for a long time, a liquid level detection device 1019 can be provided on the absorption tower shell corresponding to the first chamber 1011, and a third flow meter 126 and a third flow regulating valve 127 can be provided on the fifth delivery pipeline 124.

[0114] Among them, the liquid level detection device 1019 can be used to detect the liquid level of the solution in the first chamber 1011, and the liquid level detection device 1019 can be specifically a liquid level gauge. In the specific implementation, the upper port F of the liquid level gauge and the lower port G of the liquid level gauge can be provided on the shell of the absorption tower 101 corresponding to the first chamber 1011, and the upper port F of the liquid level gauge and the lower port G of the liquid level gauge are connected to the liquid level gauge. In the actual setting, the upper port F of the liquid level gauge can be located above the highest liquid level, and the lower port G of the liquid level gauge can be located below the lowest liquid level. Among them, the highest liquid level can be set according to the height of the first baffle 1013, for example, the highest liquid level can be 300mm~1500mm above the highest point of the first baffle 1013. The lowest liquid level can be 300mm~500mm above the bottom of the kettle of the absorption tower 101. The highest liquid level and the lowest liquid level can also be regarded as alarm levels.

[0115] The third flow meter 126 can be used to detect the flow rate of the single-phase absorption liquid in the fifth delivery pipeline 124 in real time, and the third flow regulating valve 127 can be used to regulate the flow rate of the single-phase absorption liquid in the fifth delivery pipeline 124 .

[0116] Furthermore, in order to realize automatic control of the liquid level of the solution in the first chamber 1011 , a liquid level controller 128 may be provided on the shell of the absorption tower 101 corresponding to the first chamber 1011 , and a single-phase flow controller 129 may be provided on the fifth delivery pipeline 124 .

[0117] Taking into account the same phase change absorbent formula, affected by factors such as flue gas flow rate, carbon dioxide concentration in flue gas, impurities in flue gas and absorption temperature, in addition to the possible phase separation situation where the CO2-lean phase is the heavy phase and the CO2-rich phase is the light phase or the CO2-lean phase is the light phase and the CO2-rich phase is the heavy phase, there may also be a situation where no phase separation occurs, that is, the phase change absorbent remains a single phase after absorbing carbon dioxide, and a single-phase absorption liquid (also called rich liquid) is obtained.

[0118] In order to enable the carbon dioxide capture system 100 provided in the embodiment of the present application to further take into account the above-mentioned non-phase separation situation, in one embodiment, the bottom of the first chamber 1011 is further provided with a second outlet H, the bottom of the second chamber 1012 is provided with a third outlet I, and the carbon dioxide capture system 100 further includes a sixth delivery pipeline 130; the second outlet H of the first chamber 1011 is connected to the third outlet I of the second chamber 1012 through the sixth delivery pipeline 130. In practical applications, a switch valve 131 may be further provided on the sixth delivery pipeline 130.

[0119] Thus, when a phase change absorbent is used as the absorbent of the absorption tower 101, and the phase separation result in the second chamber 1012 is that no phase separation occurs and it is still a single phase, the switch valve 131 and the fifth delivery pipeline 124 can be opened to draw the solution in the tower bottom of the absorption tower 101 (i.e., the solution in the first chamber 1011 and the second chamber 1012), i.e., the single-phase absorption liquid, from the first outlet E, and then transported to the heat exchange unit 109 through the fifth delivery pipeline 124. In the heat exchange unit 109, the single-phase absorption liquid is heat exchanged with the high-temperature lean liquid drawn from the tower bottom of the regeneration tower 110. The single-phase absorption liquid after heat exchange is further input into the regeneration tower 110 for carbon dioxide desorption, and the lean liquid whose temperature is reduced after heat exchange is further transported to the absorbent mixing unit 108.

[0120] Since a single-phase absorbent is used as the absorbent of the absorption tower 101 and the phase change absorbent is still in a single phase after absorbing carbon dioxide, all the absorption liquid is transported to the heat exchange unit 109, and the heat exchange capacity requirement is relatively large. Therefore, in an embodiment of the present application, the heat exchange unit 109 may include a first heat exchanger 1091 and a second heat exchanger 1092; the light phase outlet A is connected to the first inlet of the first heat exchanger 1091 through the second delivery pipeline 105, and the heavy phase outlet B is connected to the first inlet of the first heat exchanger 1091 through the fourth delivery pipeline 107; the first outlet E of the first chamber 1011 is connected to the first inlet of the first heat exchanger 1091 and the first inlet of the second heat exchanger 1092 through the fifth delivery pipeline 124; the first outlet of the first heat exchanger 1091 and the first outlet of the second heat exchanger 1092 are both connected to the inlet of the regeneration tower 110, and the second inlet of the first heat exchanger 1091 and the second inlet of the second heat exchanger 1092 are both connected to the bottom of the regeneration tower 110; the second outlet of the first heat exchanger 1091 and the second outlet of the second heat exchanger 1092 are both connected to the inlet of the absorbent mixing unit 108.

[0121] When the phases are separated to obtain a light phase solution and a heavy phase solution, the CO2-rich phase is transported to the heat exchange unit 109, specifically, the CO2-rich phase can be transported to the first heat exchanger 1091. In the first heat exchanger 1091, the CO2-rich phase is heat exchanged with the high-temperature lean liquid drawn from the bottom of the regeneration tower 110. The CO2-rich phase after the heat exchange is further input into the regeneration tower 110 for carbon dioxide desorption, and the lean liquid with a reduced temperature after the heat exchange is further transported to the absorbent mixing unit 108.

[0122] When the single-phase absorption liquid is transported to the heat exchange unit 109, the single-phase absorption liquid may be split and transported to the first heat exchanger 1091 and the second heat exchanger 1092. In the first heat exchanger 1091, the single-phase absorption liquid is heat exchanged with the high-temperature lean liquid drawn from the bottom of the regeneration tower 110. The single-phase absorption liquid after heat exchange is further input into the regeneration tower 110 for carbon dioxide desorption, and the lean liquid with a lowered temperature after heat exchange is further transported to the absorbent mixing unit 108. The second heat exchanger 1092 is similar, and will not be described in detail here.

[0123] In practical applications, in order to simplify the control of the system, the carbon dioxide capture system 100 provided in the embodiment of the present application may also include a rich liquid main pipeline 132 and a rich liquid three-way valve 133. The outlets of the second delivery pipeline 105, the fourth delivery pipeline 107 and the fifth delivery pipeline 124 are all connected to the inlet of the rich liquid main pipeline 132; the rich liquid three-way valve 133 is arranged at the outlet position of the rich liquid main pipeline 132, that is, at the branch of the pipeline. The other two interfaces of the rich liquid three-way valve 133 are respectively connected to the inlets of the two branch pipelines, namely the inlet of the first rich liquid branch pipeline 134 and the inlet of the second rich liquid branch pipeline 135. The outlet of the first rich liquid branch pipeline 134 is connected to the first inlet of the first heat exchanger 1091, and the outlet of the second rich liquid branch pipeline 135 is connected to the first inlet of the second heat exchanger 1092.

[0124] It can be understood that when the phases are separated to obtain a light phase solution and a heavy phase solution, and the CO2-rich phase is transported to the first heat exchanger 1091, the CO2-rich phase can be transported to the first heat exchanger 1091 through the rich liquid main pipeline 132 and the first rich liquid branch pipeline 134. When the single-phase absorption liquid is diverted and transported to the first heat exchanger 1091 and the second heat exchanger 1092, the single-phase absorption liquid can first enter the rich liquid main pipeline 132, then be diverted to the first rich liquid branch pipeline 134 and the second rich liquid branch pipeline 135, and then be transported to the first heat exchanger 1091 via the first rich liquid branch pipeline 134, and transported to the second heat exchanger 1092 via the second rich liquid branch pipeline 135. After the single-phase absorption liquid with increased temperature output from the first heat exchanger 1091 and the second heat exchanger 1092 is merged, it is further input into the regeneration tower 110 for carbon dioxide desorption.

[0125] In the case where the heat exchange unit 109 includes a first heat exchanger 1091 and a second heat exchanger 1092, correspondingly, the carbon dioxide capture system 100 provided in the embodiment of the present application may also include a first lean liquid main pipeline 136, a first lean liquid three-way valve 137, a first lean liquid branch pipeline 138 and a second lean liquid branch pipeline 139. Among them, the tower bottom of the regeneration tower 110 is connected to the inlet of the first lean liquid main pipeline 136, and the first lean liquid three-way valve 137 is arranged at the outlet position of the first lean liquid main pipeline 136, that is, at the pipeline branch. The other two interfaces of the first lean liquid three-way valve 137 are respectively connected to the inlet of the first lean liquid branch pipeline 138 and the inlet of the second lean liquid branch pipeline 139, the outlet of the first lean liquid branch pipeline 138 is connected to the second inlet of the first heat exchanger 1091, and the outlet of the second lean liquid branch pipeline 139 is connected to the second inlet of the second heat exchanger 1092. Further, a lean liquid pump 140 may also be arranged on the first lean liquid main pipeline 136.

[0126] Since when a single-phase absorbent is used as the absorbent of the absorption tower 101 and the phase change absorbent remains single-phase after absorbing carbon dioxide, all the absorption liquid is transported to the heat exchange unit 109, and the system flow is relatively large. In order to match the flow, in one embodiment, the absorbent mixing unit 108 includes a first mixer 1081 and a second mixer 1082; the light phase outlet A is connected to the inlet of the first mixer 1081 through the first conveying pipeline 104, and the heavy phase outlet B is connected to the inlet of the second mixer 1082 through the third conveying pipeline 106; the second outlet of the first heat exchanger 1091 is connected to both the inlet of the first mixer 1081 and the inlet of the second mixer 1082, and the second outlet of the second heat exchanger 1092 is connected to both the inlet of the first mixer 1081 and the inlet of the second mixer 1082.

[0127] Among them, the first mixer 1081 can be used as a light phase mixer, and the second mixer 1082 can be used as a heavy phase mixer.

[0128] That is, when the light phase solution output from the light phase outlet A is a CO2-lean phase, and the heavy phase solution output from the heavy phase outlet B is a CO2-rich phase, the light phase solution can be transported to the first mixer 1081. When the light phase solution output from the light phase outlet A is a CO2-rich phase, and the heavy phase solution output from the heavy phase outlet B is a CO2-lean phase, the heavy phase solution can be transported to the second mixer 1082.

[0129] In practical applications, in order to simplify the control of the system, the carbon dioxide capture system 100 provided in the embodiment of the present application may also include a second lean liquid main pipeline 141, a second lean liquid three-way valve 142, a third lean liquid branch pipeline 143 and a fourth lean liquid branch pipeline 144. Among them, the second outlet of the first heat exchanger 1091 and the second outlet of the second heat exchanger 1092 are both connected to the inlet of the second lean liquid main pipeline 141, and the second lean liquid three-way valve 142 is arranged at the outlet position of the second lean liquid main pipeline 141, that is, at the pipeline branch. The other two interfaces of the second lean liquid main pipeline 141 are respectively connected to the inlet of the third lean liquid branch pipeline 143 and the inlet of the fourth lean liquid branch pipeline 144, the outlet of the third lean liquid branch pipeline 143 is connected to the inlet of the first mixer 1081, and the outlet of the fourth lean liquid branch pipeline 144 is connected to the inlet of the second mixer 1082.

[0130] That is, the lean liquid output from the first heat exchanger 1091 and the second heat exchanger 1092 first merge in the second lean liquid main pipeline 141, and then transported to the first mixer 1081 through the third lean liquid branch pipeline 143, or transported to the second mixer 1082 through the fourth lean liquid branch pipeline 144, or transported to the first mixer 1081 and the second mixer 1082 through the third lean liquid branch pipeline 143 and the fourth lean liquid branch pipeline 144, respectively. Specifically, when the light phase solution is transported to the first mixer 1081, the lean liquid output from the first heat exchanger 1091 and the second heat exchanger 1092 can first merge in the second lean liquid main pipeline 141, and then transported to the first mixer 1081 through the third lean liquid branch pipeline 143. When the heavy phase solution is transported to the second mixer 1082, the lean liquid output from the first heat exchanger 1091 and the second heat exchanger 1092 may first be combined in the second lean liquid main pipeline 141, and then be transported to the second mixer 1082 through the fourth lean liquid branch pipeline 144. When the single-phase absorption liquid is transported to the first heat exchanger 1091 and the second heat exchanger 1092, the lean liquid output from the first heat exchanger 1091 and the second heat exchanger 1092 may first be combined in the second lean liquid main pipeline 141, and then be transported to the first mixer 1081 and the second mixer 1082 through the third lean liquid branch pipeline 143 and the fourth lean liquid branch pipeline 144, respectively.

[0131] It can be understood that the carbon dioxide capture system 100 provided based on the above embodiment of the present application is not only applicable to the two phase separation situations produced by the use of phase change absorbents - the lean CO2 phase is the heavy phase and the rich CO2 phase is the light phase, and the lean CO2 phase is the light phase and the rich CO2 phase is the heavy phase, but also applicable to the situation of no phase separation produced by the use of phase change absorbents, and also applicable to the situation of using single-phase absorbents. It can be seen that the carbon dioxide capture system 100 provided by the above embodiment of the present application basically takes into account the single-phase situation and various phase separation situations, and has great versatility.

[0132] In specific implementation, the carbon dioxide capture system 100 provided in the above embodiment of the present application can further be combined with the flue gas treatment device 201 disclosed by the applicant in CN115970460B, the solvent recovery unit 202, the interstage cooling unit 203 and the regeneration gas condensation unit 204 disclosed by the applicant in CN116531918B, and the amine liquid purification device 205 disclosed by the applicant in CN116870663A, such as Figure 3 The locations of the flue gas treatment device 201, the solvent recovery unit 202, the interstage cooling unit 203, the regeneration gas condensation unit 204 and the amine liquid purification device 205 can refer to the relevant contents in CN115970460B, CN116531918B and CN116870663A respectively, which will not be repeated here.

[0133] Based on the carbon dioxide capture system provided in the above embodiment of the present application, an embodiment of the present application further provides a control method for the carbon dioxide capture system, which can be understood as a control method corresponding to the carbon dioxide capture system without the fifth transmission pipeline and the sixth transmission pipeline. The control method may include steps (1) and (2), which are as follows:

[0134] Step (1), in response to the carbon dioxide content in the light phase solution being less than the carbon dioxide content in the heavy phase solution, opening the first delivery pipeline, closing the second delivery pipeline, and controlling the light phase solution to be delivered to the absorbent mixing unit via the first delivery pipeline; and closing the third delivery pipeline, opening the fourth delivery pipeline, and controlling the heavy phase solution to be delivered to the heat exchange unit via the fourth delivery pipeline.

[0135] In specific implementation, in order to realize automatic control, a mode selection controller for controlling the carbon dioxide capture system can be further provided, and all signals can be transmitted to the mode selection controller, which issues control instructions. The parameters related to the carbon dioxide content detected by the first carbon dioxide detection device and the second carbon dioxide detection device can be transmitted to the mode selection controller, and the mode selection controller calculates the difference between the carbon dioxide content in the light phase solution and the carbon dioxide content in the heavy phase solution, and selects the mode and implements corresponding control according to the difference.

[0136] When the carbon dioxide content in the light phase solution is less than that in the heavy phase solution, it means that the light phase outlet outputs a CO2-lean phase and the heavy phase outlet outputs a CO2-rich phase. At this time, the mode selection controller automatically identifies it as mode 1 and triggers the following control process:

[0137] Open the first delivery pipeline, close the second delivery pipeline, and control the light phase solution to be delivered to the absorbent mixing unit via the first delivery pipeline; and close the third delivery pipeline, open the fourth delivery pipeline, and control the heavy phase solution to be delivered to the heat exchange unit via the fourth delivery pipeline.

[0138] In the heat exchange unit, the CO2-rich phase is heat exchanged with the high-temperature lean liquid drawn from the bottom of the regeneration tower. The CO2-rich phase after heat exchange is further input into the regeneration tower for carbon dioxide desorption, and the lean liquid cooled after heat exchange is further input into the absorbent mixing unit. In the absorbent mixing unit, the lean CO2 phase and the lean liquid are mixed to obtain an absorbent, which is further transported to the absorption tower to continue to participate in the reaction of absorbing carbon dioxide.

[0139] In this embodiment, the heat exchange unit may include only one heat exchanger, and the absorbent mixing unit may include only one mixer.

[0140] In practical applications, since the change in the circulating flow rate of the CO2-rich phase has a greater impact on the two-phase interface, the position of the two-phase interface in the second chamber can be controlled based on the interface controller and the heavy phase flow controller to maintain the stability of the two-phase interface. For example, a normal two-phase interface position can be set. When the measured two-phase interface position is greater than the normal two-phase interface position, the second flow control valve opening can be controlled to increase; when the measured two-phase interface position is less than the normal two-phase interface position, the second flow control valve opening can be controlled to decrease. Among them, the normal two-phase interface position can be determined according to the optimal operating light phase solution and heavy phase solution distribution ratio of the phase change absorbent used.

[0141] Furthermore, the light phase solution flow rate can be controlled based on the light phase flow controller, so that the light phase solution flow rate = absorbent flow rate - heavy phase solution flow rate. In this way, the long-term stable operation of the carbon dioxide capture system can be ensured.

[0142] Step (2), in response to the carbon dioxide content in the light phase solution being greater than the carbon dioxide content in the heavy phase solution, closing the first delivery pipeline, opening the second delivery pipeline, and controlling the light phase solution to be delivered to the heat exchange unit via the second delivery pipeline; and opening the third delivery pipeline, closing the fourth delivery pipeline, and controlling the heavy phase solution to be delivered to the absorbent mixing unit via the third delivery pipeline.

[0143] When the carbon dioxide content in the light phase solution is greater than that in the heavy phase solution, it means that the light phase outlet outputs a CO2-rich phase and the heavy phase outlet outputs a CO2-poor phase. At this time, the mode selection controller automatically identifies mode 2 and triggers the following control process:

[0144] The first delivery pipeline is closed, the second delivery pipeline is opened, and the light phase solution is controlled to be delivered to the heat exchange unit via the second delivery pipeline; and the third delivery pipeline is opened, the fourth delivery pipeline is closed, and the heavy phase solution is controlled to be delivered to the absorbent mixing unit via the third delivery pipeline.

[0145] Similarly, in the heat exchange unit, the CO2-rich phase is heat exchanged with the high-temperature lean liquid drawn from the bottom of the regeneration tower. The CO2-rich phase after heat exchange is further input into the regeneration tower for carbon dioxide desorption, and the lean liquid cooled after heat exchange is further input into the absorbent mixing unit. In the absorbent mixing unit, the lean CO2 phase and the lean liquid are mixed to obtain an absorbent, which is further transported to the absorption tower to continue to participate in the reaction of absorbing carbon dioxide.

[0146] In this embodiment, the heat exchange unit may include only one heat exchanger, and the absorbent mixing unit may include only one mixer.

[0147] In practical applications, since the change in the circulating flow rate of the CO2-rich phase has a greater impact on the two-phase interface, the position of the two-phase interface in the second chamber can be controlled based on the interface controller and the light phase flow controller to maintain the stability of the two-phase interface. For example, a normal two-phase interface position can be set. When the measured two-phase interface position is greater than the normal two-phase interface position, the opening of the first flow regulating valve can be controlled to decrease; when the measured two-phase interface position is less than the normal two-phase interface position, the opening of the first flow regulating valve can be controlled to increase. Among them, the normal two-phase interface position can be determined according to the optimal operating light phase solution and heavy phase solution distribution ratio of the phase change absorbent used.

[0148] Furthermore, the heavy phase solution flow rate can be controlled based on the heavy phase flow controller, so that the heavy phase solution flow rate = absorbent flow rate - light phase solution flow rate. In this way, the long-term stable operation of the carbon dioxide capture system can be ensured.

[0149] It can be understood that the control method of the carbon dioxide capture system provided by the above embodiment of the present application can make the carbon dioxide capture system suitable for the two phase separation conditions produced by the phase change absorbent - the lean CO2 phase is the heavy phase and the rich CO2 phase is the light phase and the lean CO2 phase is the light phase and the rich CO2 phase is the heavy phase. In addition, automatic control can be achieved to improve the control efficiency and the reliability and safety of the system.

[0150] Based on the carbon dioxide capture system provided in the above embodiment of the present application, another embodiment of the present application further provides a control method for the carbon dioxide capture system, which can be understood as a control method corresponding to the carbon dioxide capture system containing the fifth transmission pipeline but not the sixth transmission pipeline. The control method may include steps (1), (2) and (3), as follows:

[0151] Step (1), in response to the carbon dioxide content in the light phase solution being less than the carbon dioxide content in the heavy phase solution, opening the first delivery pipeline, closing the second delivery pipeline, and controlling the light phase solution to be delivered to the absorbent mixing unit via the first delivery pipeline; and closing the third delivery pipeline, opening the fourth delivery pipeline, and controlling the heavy phase solution to be delivered to the heat exchange unit via the fourth delivery pipeline. During this control process, the fifth delivery pipeline remains closed.

[0152] This step (1) corresponds to mode 1. The specific control process can refer to the above content and will not be repeated here.

[0153] In the case where the heat exchange unit includes a first heat exchanger and a second heat exchanger, and the absorbent mixing unit includes a first mixer and a second mixer, the light phase solution is controlled to be transported to the absorbent mixing unit via the first transport pipeline, specifically: the light phase solution is controlled to be transported to the first mixer via the first transport pipeline; the heavy phase solution is controlled to be transported to the heat exchange unit via the fourth transport pipeline, specifically: the heavy phase solution is controlled to be transported to the first heat exchanger via the fourth transport pipeline.

[0154] In the first heat exchanger, the CO2-rich phase is heat exchanged with the high-temperature lean liquid drawn from the bottom of the regeneration tower. The CO2-rich phase after heat exchange is further input into the regeneration tower for carbon dioxide desorption, and the lean liquid cooled after heat exchange is further input into the first mixer. In the first mixer, the lean CO2 phase and the lean liquid are mixed to obtain an absorbent, which is further transported to the absorption tower to continue to participate in the reaction of absorbing carbon dioxide.

[0155] At this time, the control logic of mode 1 can be as follows Figure 4 shown.

[0156] In practical applications, due to the change in the circulation flow rate of the CO2-rich phase, the impact on the two-phase interface is greater. Therefore, the position of the two-phase interface in the second chamber can be controlled based on the interface controller and the heavy phase flow controller, and the light phase solution flow rate can be controlled based on the light phase flow controller. The specific control process can refer to the above content and will not be repeated here.

[0157] Step (2), in response to the carbon dioxide content in the light phase solution being greater than the carbon dioxide content in the heavy phase solution, closing the first delivery pipeline, opening the second delivery pipeline, and controlling the light phase solution to be delivered to the heat exchange unit via the second delivery pipeline; and opening the third delivery pipeline, closing the fourth delivery pipeline, and controlling the heavy phase solution to be delivered to the absorbent mixing unit via the third delivery pipeline. During this control process, the fifth delivery pipeline remains closed.

[0158] This step (2) corresponds to mode 2. The specific control process can refer to the above content and will not be repeated here.

[0159] In the case where the heat exchange unit includes a first heat exchanger and a second heat exchanger, and the absorbent mixing unit includes a first mixer and a second mixer, the light phase solution is controlled to be transported to the heat exchange unit via the second transport pipeline, specifically: the light phase solution is controlled to be transported to the first heat exchanger via the second transport pipeline; the heavy phase solution is controlled to be transported to the absorbent mixing unit via the third transport pipeline, specifically: the heavy phase solution is controlled to be transported to the second mixer via the third transport pipeline.

[0160] In the first heat exchanger, the CO2-rich phase is heat exchanged with the high-temperature lean liquid drawn from the bottom of the regeneration tower. The CO2-rich phase after heat exchange is further input into the regeneration tower for carbon dioxide desorption, and the lean liquid cooled after heat exchange is further input into the second mixer. In the second mixer, the lean CO2 phase and the lean liquid are mixed to obtain an absorbent, which is further transported to the absorption tower to continue to participate in the reaction of absorbing carbon dioxide.

[0161] At this time, the control logic of mode 2 can be as follows Figure 5 shown.

[0162] In practical applications, due to the change in the circulation flow rate of the CO2-rich phase, the impact on the two-phase interface is greater. Therefore, the position of the two-phase interface in the second chamber can be controlled based on the interface controller and the light phase flow controller, and the flow rate of the heavy phase solution can be controlled based on the heavy phase flow controller. The specific control process can refer to the above content and will not be repeated here.

[0163] Step (3), in response to the absorbent being a single-phase absorbent, closing the first delivery pipeline, the second delivery pipeline, the third delivery pipeline, and the fourth delivery pipeline, opening the fifth delivery pipeline, and controlling the solution in the first chamber to be delivered to the heat exchange unit.

[0164] When the absorbent is a single-phase absorbent, the mode selection controller selects mode three (the trigger signal of mode three may be that the position of the two-phase interface in the second chamber is equal to the liquid level and equal to zero), and triggers the following control process:

[0165] The first delivery pipeline, the second delivery pipeline, the third delivery pipeline and the fourth delivery pipeline are closed, and the fifth delivery pipeline is opened to control the solution in the first chamber (ie, the single-phase absorption liquid) to be delivered to the heat exchange unit.

[0166] In the heat exchange unit, the single-phase absorption liquid exchanges heat with the high-temperature lean liquid drawn from the kettle of the regeneration tower. The single-phase absorption liquid after heat exchange is further input into the regeneration tower for carbon dioxide desorption, and the lean liquid cooled after heat exchange is further input into the absorbent mixing unit. The lean liquid obtained in the absorbent mixing unit is further transported to the absorption tower to continue to participate in the reaction of absorbing carbon dioxide.

[0167] When the heat exchange unit includes a first heat exchanger and a second heat exchanger, and the absorbent mixing unit includes a first mixer and a second mixer, the solution in the first chamber is controlled to be transported to the heat exchange unit, specifically: the solution in the first chamber is controlled to be transported to the first heat exchanger and the second heat exchanger.

[0168] In the first heat exchanger, the single-phase absorption liquid is heat exchanged with the high-temperature lean liquid drawn from the tower kettle of the regeneration tower. The single-phase absorption liquid after heat exchange is further input into the regeneration tower for carbon dioxide desorption, and the lean liquid cooled after heat exchange is further input into the first mixer and the second mixer. At the same time, in the second heat exchanger, the single-phase absorption liquid is heat exchanged with the high-temperature lean liquid drawn from the tower kettle of the regeneration tower. The single-phase absorption liquid after heat exchange is further input into the regeneration tower for carbon dioxide desorption, and the lean liquid cooled after heat exchange is further input into the first mixer and the second mixer. The lean liquid obtained in the first mixer and the second mixer is further transported to the absorption tower to continue to participate in the reaction of absorbing carbon dioxide.

[0169] At this time, the control logic of mode three can be as follows Figure 6 shown.

[0170] In practical applications, the liquid level in the first chamber can also be controlled based on the liquid level controller and the single-phase flow controller to maintain the stability of the liquid level. For example, a normal liquid level can be set. When the measured liquid level is greater than the normal liquid level, the opening of the third flow regulating valve can be controlled to increase; when the measured liquid level is less than the normal liquid level, the opening of the third flow regulating valve can be controlled to decrease. The normal liquid level can be determined based on the total flow of the absorption liquid and the residence time in the absorption tower.

[0171] It can be understood that the control method of the carbon dioxide capture system provided by the above embodiment of the present application can make the carbon dioxide capture system applicable to the two phase separation situations produced by the phase change absorbent - the lean CO2 phase is the heavy phase and the rich CO2 phase is the light phase and the lean CO2 phase is the light phase and the rich CO2 phase is the heavy phase, and it is also applicable to the situation where the single-phase absorbent is used as the absorbent of the absorption tower. In addition, automatic control can be realized to improve the control efficiency and the reliability and safety of the system.

[0172] Based on the carbon dioxide capture system provided in the above embodiment of the present application, another embodiment of the present application further provides a control method for the carbon dioxide capture system, which can be understood as a control method corresponding to the carbon dioxide capture system containing the fifth transmission pipeline and the sixth transmission pipeline. The control method may include steps (1), (2), (3) and (4), as follows:

[0173] Step (1), in response to the carbon dioxide content in the light phase solution being less than the carbon dioxide content in the heavy phase solution, opening the first delivery pipeline, closing the second delivery pipeline, and controlling the light phase solution to be delivered to the absorbent mixing unit via the first delivery pipeline; and closing the third delivery pipeline, opening the fourth delivery pipeline, and controlling the heavy phase solution to be delivered to the heat exchange unit via the fourth delivery pipeline. During this control process, the fifth delivery pipeline and the sixth delivery pipeline remain closed.

[0174] This step (1) corresponds to mode 1. The specific control process can refer to the above content and will not be repeated here.

[0175] In the case where the heat exchange unit includes a first heat exchanger and a second heat exchanger, and the absorbent mixing unit includes a first mixer and a second mixer, the light phase solution is controlled to be transported to the absorbent mixing unit via the first transport pipeline, specifically: the light phase solution is controlled to be transported to the first mixer via the first transport pipeline; the heavy phase solution is controlled to be transported to the heat exchange unit via the fourth transport pipeline, specifically: the heavy phase solution is controlled to be transported to the first heat exchanger via the fourth transport pipeline.

[0176] In the first heat exchanger, the CO2-rich phase is heat exchanged with the high-temperature lean liquid drawn from the bottom of the regeneration tower. The CO2-rich phase after heat exchange is further input into the regeneration tower for carbon dioxide desorption, and the lean liquid cooled after heat exchange is further input into the first mixer. In the first mixer, the lean CO2 phase and the lean liquid are mixed to obtain an absorbent, which is further transported to the absorption tower to continue to participate in the reaction of absorbing carbon dioxide.

[0177] At this time, the control logic of mode 1 can be as follows Figure 4 shown.

[0178] In practical applications, due to the change in the circulation flow rate of the CO2-rich phase, the impact on the two-phase interface is greater. Therefore, the position of the two-phase interface in the second chamber can be controlled based on the interface controller and the heavy phase flow controller, and the light phase solution flow rate can be controlled based on the light phase flow controller. The specific control process can refer to the above content and will not be repeated here.

[0179] Step (2), in response to the carbon dioxide content in the light phase solution being greater than the carbon dioxide content in the heavy phase solution, closing the first delivery pipeline, opening the second delivery pipeline, and controlling the light phase solution to be delivered to the heat exchange unit via the second delivery pipeline; and opening the third delivery pipeline, closing the fourth delivery pipeline, and controlling the heavy phase solution to be delivered to the absorbent mixing unit via the third delivery pipeline. During this control process, the fifth delivery pipeline and the sixth delivery pipeline remain closed.

[0180] This step (2) corresponds to mode 2. The specific control process can refer to the above content and will not be repeated here.

[0181] In the case where the heat exchange unit includes a first heat exchanger and a second heat exchanger, and the absorbent mixing unit includes a first mixer and a second mixer, the light phase solution is controlled to be transported to the heat exchange unit via the second transport pipeline, specifically: the light phase solution is controlled to be transported to the first heat exchanger via the second transport pipeline; the heavy phase solution is controlled to be transported to the absorbent mixing unit via the third transport pipeline, specifically: the heavy phase solution is controlled to be transported to the second mixer via the third transport pipeline.

[0182] In the first heat exchanger, the CO2-rich phase is heat exchanged with the high-temperature lean liquid drawn from the bottom of the regeneration tower. The CO2-rich phase after heat exchange is further input into the regeneration tower for carbon dioxide desorption, and the lean liquid cooled after heat exchange is further input into the second mixer. In the second mixer, the lean CO2 phase and the lean liquid are mixed to obtain an absorbent, which is further transported to the absorption tower to continue to participate in the reaction of absorbing carbon dioxide.

[0183] At this time, the control logic of mode 2 can be as follows Figure 5 shown.

[0184] In practical applications, due to the change in the circulation flow rate of the CO2-rich phase, the impact on the two-phase interface is greater. Therefore, the position of the two-phase interface in the second chamber can be controlled based on the interface controller and the light phase flow controller, and the flow rate of the heavy phase solution can be controlled based on the heavy phase flow controller. The specific control process can refer to the above content and will not be repeated here.

[0185] Step (3), in response to the absorbent being a single-phase absorbent, the first delivery pipeline, the second delivery pipeline, the third delivery pipeline, and the fourth delivery pipeline are closed, the fifth delivery pipeline is opened, and the solution in the first chamber is controlled to be delivered to the heat exchange unit. During this control process, the sixth delivery pipeline remains closed.

[0186] This step (3) corresponds to mode 3. The specific control process can refer to the above content and will not be repeated here.

[0187] In the heat exchange unit, the single-phase absorption liquid exchanges heat with the high-temperature lean liquid drawn from the kettle of the regeneration tower. The single-phase absorption liquid after heat exchange is further input into the regeneration tower for carbon dioxide desorption, and the lean liquid cooled after heat exchange is further input into the absorbent mixing unit. The lean liquid obtained in the absorbent mixing unit is further transported to the absorption tower to continue to participate in the reaction of absorbing carbon dioxide.

[0188] When the heat exchange unit includes a first heat exchanger and a second heat exchanger, and the absorbent mixing unit includes a first mixer and a second mixer, the solution in the first chamber is controlled to be transported to the heat exchange unit, specifically: the solution in the first chamber is controlled to be transported to the first heat exchanger and the second heat exchanger.

[0189] In the first heat exchanger, the single-phase absorption liquid is heat exchanged with the high-temperature lean liquid drawn from the tower kettle of the regeneration tower. The single-phase absorption liquid after heat exchange is further input into the regeneration tower for carbon dioxide desorption, and the lean liquid cooled after heat exchange is further input into the first mixer and the second mixer. At the same time, in the second heat exchanger, the single-phase absorption liquid is heat exchanged with the high-temperature lean liquid drawn from the tower kettle of the regeneration tower. The single-phase absorption liquid after heat exchange is further input into the regeneration tower for carbon dioxide desorption, and the lean liquid cooled after heat exchange is further input into the first mixer and the second mixer. The lean liquid obtained in the first mixer and the second mixer is further transported to the absorption tower to continue to participate in the reaction of absorbing carbon dioxide.

[0190] At this time, the control logic of mode three can be as follows Figure 6 shown.

[0191] In practical applications, the liquid level in the first chamber can also be controlled based on the liquid level controller and the single-phase flow controller to maintain the stability of the liquid level. For example, a normal liquid level can be set. When the measured liquid level is greater than the normal liquid level, the opening of the third flow regulating valve can be controlled to increase; when the measured liquid level is less than the normal liquid level, the opening of the third flow regulating valve can be controlled to decrease. The normal liquid level can be determined based on the total flow of the absorption liquid and the residence time in the absorption tower.

[0192] Step (4), in response to the second chamber containing single-phase absorption liquid, closing the first delivery pipeline, the second delivery pipeline, the third delivery pipeline and the fourth delivery pipeline, opening the fifth delivery pipeline and the sixth delivery pipeline, and controlling the solution in the bottom of the absorption tower to be delivered to the heat exchange unit.

[0193] In the case where the absorbent is a phase-change absorbent, when the second chamber contains a single-phase absorption liquid (which can be characterized by the liquid level in the second chamber being equal to the position of the two-phase interface and not equal to zero), it means that the phase separation result in the second chamber is that there is no phase separation and it is still a single phase, that is, the solution in the bottom of the absorption tower during this period is a single-phase absorption liquid. In this case, the mode selection controller selects mode 4 (the trigger signal of mode 4 can be that the position of the two-phase interface in the second chamber is equal to the liquid level and not equal to zero), and triggers the following control process:

[0194] The first, second, third and fourth delivery pipelines are closed, and the fifth and sixth delivery pipelines are opened to control the solution in the bottom of the absorption tower (i.e., the solution in the first chamber and the second chamber) to be delivered to the heat exchange unit.

[0195] In the heat exchange unit, the single-phase absorption liquid exchanges heat with the high-temperature lean liquid drawn from the kettle of the regeneration tower. The single-phase absorption liquid after heat exchange is further input into the regeneration tower for carbon dioxide desorption, and the lean liquid cooled after heat exchange is further input into the absorbent mixing unit. The lean liquid obtained in the absorbent mixing unit is further transported to the absorption tower to continue to participate in the reaction of absorbing carbon dioxide.

[0196] When the heat exchange unit includes a first heat exchanger and a second heat exchanger, and the absorbent mixing unit includes a first mixer and a second mixer, the solution in the bottom of the absorption tower is controlled to be transported to the heat exchange unit, specifically: the solution in the bottom of the absorption tower is controlled to be transported to the first heat exchanger and the second heat exchanger.

[0197] In the first heat exchanger, the single-phase absorption liquid is heat exchanged with the high-temperature lean liquid drawn from the tower kettle of the regeneration tower. The single-phase absorption liquid after heat exchange is further input into the regeneration tower for carbon dioxide desorption, and the lean liquid cooled after heat exchange is further input into the first mixer and the second mixer. At the same time, in the second heat exchanger, the single-phase absorption liquid is heat exchanged with the high-temperature lean liquid drawn from the tower kettle of the regeneration tower. The single-phase absorption liquid after heat exchange is further input into the regeneration tower for carbon dioxide desorption, and the lean liquid cooled after heat exchange is further input into the first mixer and the second mixer. The lean liquid obtained in the first mixer and the second mixer is further transported to the absorption tower to continue to participate in the reaction of absorbing carbon dioxide.

[0198] At this time, the control logic of mode 4 can be as follows Figure 7 shown.

[0199] In practical applications, the liquid level in the tower kettle of the absorption tower can also be controlled based on the liquid level controller and the single-phase flow controller to maintain the stability of the liquid level. For example, a normal liquid level can be set. When the measured liquid level is greater than the normal liquid level, the opening of the third flow regulating valve can be controlled to increase; when the measured liquid level is less than the normal liquid level, the opening of the third flow regulating valve can be controlled to decrease. The normal liquid level can be determined based on the total flow of the absorption liquid and the residence time in the absorption tower.

[0200] It can be understood that the control method of the carbon dioxide capture system provided by the above embodiment of the present application can make the carbon dioxide capture system not only applicable to the two phase separation situations of the lean CO2 phase as the heavy phase and the rich CO2 phase as the light phase and the lean CO2 phase as the light phase and the rich CO2 phase as the heavy phase generated by the phase change absorbent, but also applicable to the situation of no phase separation generated by the phase change absorbent, and also applicable to the situation of using a single-phase absorbent. In addition, automatic control can be realized to improve the control efficiency and the reliability and safety of the system.

[0201] In addition, the carbon dioxide capture system and control method thereof provided in the embodiments of the present application can also make the system have lower energy consumption. This is because after the controllability of phase change absorption is enhanced, the flow rate of rich liquid involved in regeneration and desorption can be controlled, and the energy consumption of regeneration and desorption can be maintained at a lower level, thereby allowing the carbon dioxide capture system to operate at lower energy consumption.

[0202] The following will be combined with specific examples to illustrate the above scheme provided in this application. It should be understood that the following examples are only some specific implementation methods and do not represent improper limitations on the scheme of this application.

[0203] The carbon dioxide capture system corresponding to the following Examples 1 to 4 is a carbon dioxide capture system containing a fifth delivery pipeline and a sixth delivery pipeline, and the heat exchange unit includes a first heat exchanger and a second heat exchanger, and the absorbent mixing unit includes a first mixer and a second mixer. Among them, the diameter of the packing section of the absorption tower is 5200mm, the diameter of the tower kettle section of the absorption tower is 7000mm, the first baffle is 2500mm away from the left tower wall, the height of the first baffle is 5800mm, the height of the upper opening of the interface meter is 5400mm, the height of the lower opening of the interface meter is 300mm, the height of the first light phase outlet is 4800mm, the height of the second light phase outlet is 4300mm, the height of the detection port corresponding to the first carbon dioxide detection device is 5000mm, and the height of the detection port corresponding to the second carbon dioxide detection device is 500mm. The first carbon dioxide detection device and the second carbon dioxide detection device are chromatographic online detection instruments.

[0204] Example 1

[0205] The absorbent is a phase change absorbent, and its composition by mass ratio is: 50% of the phase separation agent component diethylethanolamine (DEEA), 25% of the main absorbent component monoethanolamine (MEA) and 25% of water.

[0206] The absorption liquid formed by the phase change absorbent after absorbing carbon dioxide overflows from the first chamber of the absorption tower to the second chamber, and is separated into a light phase solution and a heavy phase solution by a phase separation device in the second chamber.

[0207] After testing, the mass content of carbon dioxide in the light phase solution is 1.6wt%, and the mass content of carbon dioxide in the heavy phase solution is 8.2wt%. The mass content of carbon dioxide in the light phase solution is less than that in the heavy phase solution, triggering mode 1 and the following control process:

[0208] The first delivery pipeline is opened, the second delivery pipeline is closed, and the light phase solution is controlled to be delivered to the first mixer via the first delivery pipeline; and the third delivery pipeline is closed, the fourth delivery pipeline is opened, and the heavy phase solution is controlled to be delivered to the first heat exchanger via the fourth delivery pipeline. During this control process, the fifth delivery pipeline and the sixth delivery pipeline remain closed.

[0209] The highest two-phase interface position of the second chamber is set to 3600mm, the lowest two-phase interface position is set to 3000mm, and the normal two-phase interface position is set to 3300mm. When the measured two-phase interface position is ≠3300mm, the interface controller and the heavy phase flow controller are triggered to perform cascade control: when the measured two-phase interface position is >3300mm, the opening of the second flow control valve increases; when the measured two-phase interface position is <3300mm, the opening of the second flow control valve decreases; until the measured two-phase interface position is adjusted to be equal to or approximately equal to 3300mm.

[0210] After testing, the flow rate of the heavy phase solution is 228m 3 / h, the flow rate of the phase change absorbent at the absorbent inlet of the absorption tower is 380m 3 / h, the light phase flow controller controls the first flow regulating valve so that the light phase solution flow = absorbent flow - heavy phase solution flow = 152m 3 / h.

[0211] According to calculation, when the carbon dioxide capture system provided in this embodiment is used to perform the above control, the regeneration energy consumption of carbon dioxide after stable operation is 2.2 GJ / tCO2.

[0212] Example 2

[0213] The absorbent is a phase change absorbent. By mass proportion, the composition of the phase change absorbent is: 50% of the phase separation agent component cyclopentane sulfone, 13% of the main absorbent component monoethanolamine (MEA), 22% of 2-amino-2-methyl-1-propanol (AMP) and 15% of water.

[0214] The absorption liquid formed by the phase change absorbent after absorbing carbon dioxide overflows from the first chamber of the absorption tower to the second chamber, and is separated into a light phase solution and a heavy phase solution by a phase separation device in the second chamber.

[0215] After testing, the mass content of carbon dioxide in the light phase solution is 7.7wt%, and the mass content of carbon dioxide in the heavy phase solution is 1.5wt%. The mass content of carbon dioxide in the light phase solution is greater than that in the heavy phase solution, triggering mode 2 and the following control process:

[0216] The first delivery pipeline is closed, the second delivery pipeline is opened, and the light phase solution is controlled to be delivered to the first heat exchanger via the second delivery pipeline; and the third delivery pipeline is opened, the fourth delivery pipeline is closed, and the heavy phase solution is controlled to be delivered to the second mixer via the third delivery pipeline. During this control process, the fifth delivery pipeline and the sixth delivery pipeline remain closed.

[0217] The highest two-phase interface position of the second chamber is set to 4100mm, the lowest two-phase interface position is set to 3700mm, and the normal two-phase interface position is set to 3900mm. When the measured two-phase interface position is ≠3900mm, the interface controller and the light phase flow controller are triggered to perform cascade control: when the measured two-phase interface position is >3900mm, the opening of the first flow control valve is reduced; when the measured two-phase interface position is <3900mm, the opening of the first flow control valve is increased; until the measured two-phase interface position is adjusted to be equal to or approximately equal to 3900mm.

[0218] After testing, the flow rate of the light phase solution is 247m 3 / h, the flow rate of the phase change absorbent at the absorbent inlet of the absorption tower is 355m 3 / h, the heavy phase flow controller controls the second flow regulating valve so that the heavy phase solution flow = absorbent flow - light phase solution flow = 108m 3 / h.

[0219] According to calculation, when the carbon dioxide capture system provided in this embodiment is used to perform the above control, the regeneration energy consumption of carbon dioxide after stable operation is 2.1 GJ / tCO2.

[0220] Example 3

[0221] The absorbent is a phase change absorbent, and the composition of the phase change absorbent is the same as that of Example 2.

[0222] After testing, the measured position of the two-phase interface in the second chamber is 5500mm, the measured liquid level in the second chamber is 5500mm, the two-phase interface position is equal to the liquid level and is not equal to zero, triggering mode four and triggering the following control process:

[0223] The first delivery pipeline, the second delivery pipeline, the third delivery pipeline and the fourth delivery pipeline are closed, and the fifth delivery pipeline and the sixth delivery pipeline are opened to control the solution in the bottom of the absorption tower to be delivered to the first heat exchanger and the second heat exchanger.

[0224] The highest liquid level of the first chamber is set to 4500mm, the lowest liquid level is set to 500mm, and the normal liquid level is set to 2600mm. When the measured liquid level is ≠2600mm, the liquid level controller and the single-phase flow controller are triggered to perform cascade control: when the measured liquid level is >2600mm, the opening of the third flow regulating valve increases; when the measured liquid level is <2600mm, the opening of the third flow regulating valve decreases until the measured liquid level is adjusted to be equal to or approximately equal to 2600mm.

[0225] According to calculation, when the carbon dioxide capture system provided in this embodiment is used to perform the above control, the regeneration energy consumption of carbon dioxide after stable operation is 2.4 GJ / tCO2.

[0226] Example 4

[0227] The absorbent is a single-phase absorbent, and its composition by mass is: 13% monoethanolamine (MEA), 22% 2-amino-2-methyl-1-propanol (AMP) and 65% water.

[0228] The absorption liquid formed by the single-phase absorbent after absorbing carbon dioxide stays in the first chamber and does not overflow into the second chamber.

[0229] After detection, the measured two-phase interface position in the second chamber is equal to the measured liquid level and equal to zero, triggering mode three and triggering the following control process:

[0230] The first delivery pipeline, the second delivery pipeline, the third delivery pipeline and the fourth delivery pipeline are closed, the fifth delivery pipeline is opened, and the solution in the first chamber is controlled to be delivered to the first heat exchanger and the second heat exchanger. During this control process, the sixth delivery pipeline remains closed.

[0231] The highest liquid level of the first chamber is set to 5500mm, the lowest liquid level is set to 500mm, and the normal liquid level is set to 4300mm. When the measured liquid level is ≠4300mm, the liquid level controller and the single-phase flow controller are triggered to perform cascade control: when the measured liquid level is >4300mm, the opening of the third flow regulating valve increases, and when the measured liquid level is <4300mm, the opening of the third flow regulating valve decreases until the measured liquid level is adjusted to be equal to or approximately equal to 4300mm.

[0232] According to calculation, when the carbon dioxide capture system provided in this embodiment is used to perform the above control, the regeneration energy consumption of carbon dioxide after stable operation is 2.4 GJ / tCO2.

[0233] It can be seen that the carbon dioxide capture system provided in the embodiment of the present application is not only applicable to the two phase separation situations produced by the use of phase change absorbents - the lean CO2 phase is the heavy phase and the rich CO2 phase is the light phase and the lean CO2 phase is the light phase and the rich CO2 phase is the heavy phase, but also applicable to the situation of no phase separation produced by the use of phase change absorbents, and also applicable to the situation of using single-phase absorbents. In addition, the carbon dioxide capture system provided in the embodiment of the present application can also achieve lower energy consumption.

[0234] It should also be noted that the terms "include", "comprises" or any other variations thereof are intended to cover non-exclusive inclusion, so that a process, method, commodity or device including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, commodity or device. In the absence of more restrictions, the elements defined by the sentence "comprises a ..." do not exclude the existence of other identical elements in the process, method, commodity or device including the elements.

[0235] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A carbon dioxide capture system, characterized in that: The carbon dioxide capture system comprises an absorption tower, a first carbon dioxide detection device, a second carbon dioxide detection device, a first delivery pipeline, a second delivery pipeline, a third delivery pipeline, a fourth delivery pipeline, an absorbent mixing unit, a heat exchange unit and a regeneration tower; The bottom of the absorption tower is divided into a first chamber and a second chamber by a partition component. The absorption liquid first flows into the first chamber, and then overflows from the first chamber to the second chamber through the top of the second chamber. The second chamber is used to separate the incoming absorption liquid into phases. The absorption tower shell corresponding to the second chamber is provided with a light phase outlet for outputting a light phase solution and a heavy phase outlet for outputting a heavy phase solution, and the density of the light phase solution is less than the density of the heavy phase solution; the first carbon dioxide detection device is used to detect parameters related to the carbon dioxide content in the light phase solution, and the second carbon dioxide detection device is used to detect parameters related to the carbon dioxide content in the heavy phase solution; The light phase outlet is communicated with the inlet of the absorbent mixing unit through the first delivery pipeline, and the light phase outlet is communicated with the first inlet of the heat exchange unit through the second delivery pipeline; the heavy phase outlet is communicated with the inlet of the absorbent mixing unit through the third delivery pipeline, and the heavy phase outlet is communicated with the first inlet of the heat exchange unit through the fourth delivery pipeline; The first outlet of the heat exchange unit is communicated with the inlet of the regeneration tower, and the second inlet of the heat exchange unit is communicated with the kettle of the regeneration tower; the second outlet of the heat exchange unit is communicated with the inlet of the absorbent mixing unit, and the outlet of the absorbent mixing unit is communicated with the absorbent inlet of the absorption tower; The first chamber has a first outlet and a second outlet at the bottom, the second chamber has a third outlet at the bottom, and the carbon dioxide capture system further includes a fifth delivery pipeline and a sixth delivery pipeline; The first outlet of the first chamber is communicated with the first inlet of the heat exchange unit through the fifth delivery pipeline, and the second outlet of the first chamber is communicated with the third outlet of the second chamber through the sixth delivery pipeline.

2. The carbon dioxide capture system according to claim 1, characterized in that An interface detection device is also provided on the absorption tower shell corresponding to the second chamber.

3. The carbon dioxide capture system according to claim 1, characterized in that The absorption tower comprises a packing section and a bottom section, and the diameter of the bottom section is larger than the diameter of the packing section.

4. The carbon dioxide capture system according to claim 1, characterized in that The partition assembly includes a first baffle and a second baffle; The first baffle extends from the bottom of the tower kettle of the absorption tower to the packing section of the absorption tower, and is used to separate the tower kettle of the absorption tower into a first chamber and a second chamber; The second baffle extends from the absorption tower shell corresponding to the top of the second chamber to the top of the first chamber, and is used to cover the top of the second chamber; A flow channel for absorption liquid is formed between the first baffle plate and the second baffle plate.

5. The carbon dioxide capture system according to claim 1, characterized in that The second chamber is also provided with a phase separation device.

6. The carbon dioxide capture system according to claim 2, characterized in that The heat exchange unit comprises a first heat exchanger and a second heat exchanger; The light phase outlet is communicated with the first inlet of the first heat exchanger through the second delivery pipeline, the heavy phase outlet is communicated with the first inlet of the first heat exchanger through the fourth delivery pipeline, and the first outlet of the first chamber is communicated with the first inlet of the first heat exchanger and the first inlet of the second heat exchanger through the fifth delivery pipeline; The first outlet of the first heat exchanger and the first outlet of the second heat exchanger are both connected to the inlet of the regeneration tower, and the second inlet of the first heat exchanger and the second inlet of the second heat exchanger are both connected to the kettle of the regeneration tower; The second outlet of the first heat exchanger and the second outlet of the second heat exchanger are both in communication with the inlet of the absorbent mixing unit.

7. The carbon dioxide capture system according to claim 6, characterized in that The absorbent mixing unit includes a first mixer and a second mixer; The light phase outlet is communicated with the inlet of the first mixer through the first delivery pipeline, and the heavy phase outlet is communicated with the inlet of the second mixer through the third delivery pipeline; The second outlet of the first heat exchanger is communicated with both the inlet of the first mixer and the inlet of the second mixer, and the second outlet of the second heat exchanger is communicated with both the inlet of the first mixer and the inlet of the second mixer.

8. The carbon dioxide capture system according to claim 2, characterized in that The second delivery pipeline is provided with a first flow meter and a first flow regulating valve; The fourth delivery pipeline is provided with a second flow meter and a second flow regulating valve.

9. The carbon dioxide capture system according to claim 2, characterized in that A liquid level detection device is provided on the absorption tower shell corresponding to the first chamber, and a third flow meter and a third flow regulating valve are provided on the fifth delivery pipeline.

10. A method for controlling a carbon dioxide capture system according to any one of claims 1 to 9, characterized in that: The control method comprises: In response to the carbon dioxide content in the light phase solution being less than the carbon dioxide content in the heavy phase solution, the first transmission pipeline is opened, the second transmission pipeline is closed, and the light phase solution is controlled to be transmitted to the absorbent mixing unit via the first transmission pipeline; and the third transmission pipeline is closed, the fourth transmission pipeline is opened, and the heavy phase solution is controlled to be transmitted to the heat exchange unit via the fourth transmission pipeline; In response to the carbon dioxide content in the light phase solution being greater than the carbon dioxide content in the heavy phase solution, the first transmission pipeline is closed, the second transmission pipeline is opened, and the light phase solution is controlled to be transmitted to the heat exchange unit via the second transmission pipeline; and the third transmission pipeline is opened, the fourth transmission pipeline is closed, and the heavy phase solution is controlled to be transmitted to the absorbent mixing unit via the third transmission pipeline; In response to the absorbent being a single-phase absorbent, closing the first delivery pipeline, the second delivery pipeline, the third delivery pipeline, and the fourth delivery pipeline, opening the fifth delivery pipeline, and controlling the solution in the first chamber to be delivered to the heat exchange unit; In response to the single-phase absorption liquid in the second chamber, the first delivery pipeline, the second delivery pipeline, the third delivery pipeline and the fourth delivery pipeline are closed, the fifth delivery pipeline and the sixth delivery pipeline are opened, and the solution in the bottom of the absorption tower is controlled to be delivered to the heat exchange unit.

11. The control method according to claim 10, characterized in that: The heat exchange unit includes a first heat exchanger and a second heat exchanger, and the absorbent mixing unit includes a first mixer and a second mixer; The controlling the light phase solution to be transported to the absorbent mixing unit via the first transport pipeline comprises: Controlling the light phase solution to be transported to the first mixer via the first transport pipeline; The controlling the heavy phase solution to be transported to the heat exchange unit via the fourth transport pipeline comprises: Controlling the heavy phase solution to be transported to the first heat exchanger via the fourth transport pipeline; The controlling the light phase solution to be transported to the heat exchange unit via the second transport pipeline comprises: Controlling the light phase solution to be transported to the first heat exchanger via the second transport pipeline; The controlling the heavy phase solution to be transported to the absorbent mixing unit via the third transport pipeline comprises: Controlling the heavy phase solution to be transported to the second mixer via the third transport pipeline; The controlling the solution in the first chamber to be transported to the heat exchange unit comprises: Controlling the solution in the first chamber to be transported to the first heat exchanger and the second heat exchanger; The controlling the solution in the bottom of the absorption tower to be transported to the heat exchange unit comprises: The solution in the bottom of the absorption tower is controlled to be transported to the first heat exchanger and the second heat exchanger.

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