Carbon capture system coupling vacuum desorption with heat pump

Abstract

The application provides a carbon capture system coupled with vacuum desorption and heat pump, comprising a regenerator, a vacuum pump assembly, a reboiler and a first heat pump assembly, a first pipeline is connected to a regenerator gas outlet at the top of the regenerator, and a lean liquid pipeline is connected to a lean liquid outlet at the bottom of the regenerator; the vacuum pump assembly is arranged in the first pipeline to vacuumize the inner cavity of the regenerator; the reboiler is connected to the regenerator, and the reboiler is connected to the regenerator through a second pipeline; the first heat pump assembly comprises a first heat exchange component and a second heat exchange component, the first heat exchange component is connected to the first pipeline, and the second heat exchange component is connected to the lean liquid pipeline or the second pipeline, so as to recover the heat of the medium in the first pipeline and heat the medium in the lean liquid pipeline or the second pipeline. The heat recovery rate of the embodiment of the application is high, and the use amount and cost of the regeneration steam are reduced.

Description

Technical Field

[0001] This invention belongs to the field of carbon capture technology, and specifically relates to a carbon capture system that couples vacuum desorption with a heat pump. Background Technology

[0002] Among related technologies, chemical absorption is a carbon capture technology, but its large-scale application faces a core bottleneck: excessively high energy consumption and cost in the regeneration process. Regeneration towers typically operate at near-atmospheric pressure and relatively high temperatures (100-120 degrees Celsius), relying on external steam in the reboiler to provide the heat required for desorption. Heating the rich liquid in the regeneration tower requires a large amount of steam, and the cost of regeneration steam accounts for more than half of the total capture cost. The regeneration gas discharged from the top of the regeneration tower (approximately 95-100 degrees Celsius) carries a large amount of latent heat of high-quality water vapor, resulting in significant energy waste and low heat recovery efficiency. Summary of the Invention

[0003] This invention is based on the inventor's discoveries and understanding of the following facts and problems:

[0004] The inventors recognized that overcoming the energy barrier of chemical reaction and heating the rich liquid requires a large amount of steam, and the cost of regenerated steam accounts for 60-70% of the total capture cost. The regenerated gas discharged from the top of the regeneration tower (95-105℃, mainly composed of carbon dioxide and water vapor) carries a large amount of latent heat of high-quality water vapor (accounting for about 30-50% of the total energy of the regenerated gas), as well as the sensible heat carried by the lean liquid, which is usually carried away by cooling water, resulting in huge energy waste.

[0005] The inventors also recognized that while related technologies recover waste heat through heat pumps, they generally suffer from system complexity, difficulty in modification, high investment, or only recover a single heat source, resulting in poor practicality.

[0006] The present invention aims to at least partially solve one of the technical problems in the related art.

[0007] Therefore, embodiments of the present invention propose a carbon capture system that couples vacuum desorption and a heat pump, which has high thermal efficiency and low energy consumption.

[0008] The carbon capture system of coupled vacuum desorption and heat pump according to an embodiment of the present invention includes: A regeneration tower, wherein the regeneration gas outlet at the top of the regeneration tower is connected to a first pipe, and the lean liquid outlet at the bottom of the regeneration tower is connected to a lean liquid pipe; A vacuum pump assembly, located in the first pipeline, is used to evacuate the interior of the regeneration tower. A reboiler is connected to the regeneration tower, and the inlet of the reboiler is connected to the regeneration tower via a second pipe; A first heat pump assembly includes a first heat exchange component and a second heat exchange component. The first heat exchange component is connected to the first pipe, and the second heat exchange component is connected to the lean liquid pipe or the second pipe to recover heat from the medium in the first pipe and use it to heat the medium in the lean liquid pipe or the second pipe.

[0009] This invention reduces the pressure in the regeneration tower and the desorption temperature by using a vacuum pump assembly to create a vacuum, thereby reducing external steam consumption in the reboiler and lowering regeneration energy consumption at the source. The first heat pump assembly recovers the waste heat from the regeneration gas to heat the lean liquid or the absorbent entering the reboiler, thus improving heat recovery efficiency and reducing heat waste. The entire system in this embodiment reduces the amount and cost of regeneration steam by coupling vacuum desorption with heat pump waste heat recovery, solving the problems of high energy consumption and high cost in carbon capture regeneration in related technologies. This allows for better large-scale application of chemical absorption carbon capture technology and reduces the cost of carbon capture.

[0010] In some embodiments, the first heat exchange component is a first evaporator, the second heat exchange component is a first condenser, and the first heat pump assembly further includes a first compressor connected between the first evaporator and the first condenser to compress the working fluid discharged from the first evaporator and deliver it to the first condenser.

[0011] In some embodiments, a compression assembly and a second heat pump assembly are also included, the compression assembly being connected to the first conduit for recovering and compressing carbon dioxide, and the outlet end of the compression assembly being connected to a third conduit.

[0012] The second heat pump assembly includes a third heat exchange component and a fourth heat exchange component. The third heat exchange component is connected to the third pipe, and the fourth heat exchange component is connected to the heat source pipe of the lean liquid pipe, the second pipe, or the heat source inlet of the reboiler, so as to recover the heat of the medium in the third pipe and use it to heat the medium in the lean liquid pipe, the second pipe, or the heat source pipe.

[0013] In some embodiments, the third heat exchange component is a second evaporator, the fourth heat exchange component is a second condenser, and the second heat pump assembly further includes a second compressor connected between the second evaporator and the second condenser to compress the working fluid discharged from the second evaporator and deliver it to the second condenser; And / or, the second heat exchange component and the fourth heat exchange component are connected to the same pipe, and in the medium flow direction of the corresponding pipe, the fourth heat exchange component is located before the second heat exchange component.

[0014] In some embodiments, the system further includes an absorption tower and a lean-rich liquid heat exchange assembly, wherein the lean liquid inlet of the absorption tower and the lean liquid outlet of the regeneration tower are connected via the lean liquid pipeline, the rich liquid outlet of the absorption tower and the rich liquid inlet of the regeneration tower are connected via a rich liquid pipeline, the cold side flow channel of the lean-rich liquid heat exchange assembly is connected to the rich liquid pipeline, and the hot side flow channel of the lean-rich liquid heat exchange assembly is connected to the lean liquid pipeline.

[0015] In some embodiments, the reboiler includes at least two heat source lines, wherein the medium in the heat source lines is used to heat the absorbent flowing into the reboiler.

[0016] In some embodiments, a cooling separation assembly is further included, the cooling separation assembly including a cooling component and a first gas-liquid separation component, the cooling component and the first gas-liquid separation component being sequentially disposed in the first pipeline and both being located downstream of the first heat exchange component, the cooling component being used to cool the medium in the first pipeline, and the first gas-liquid separation component being used to separate the liquid phase in the first pipeline and transport it back to the regeneration tower.

[0017] In some embodiments, the cooling separation assembly further includes a condensate heat exchange component and a second gas-liquid separation component. The hot-side flow channel of the condensate heat exchange component is connected to the first pipe and located upstream of the cooling component and the first heat exchange component. The cold-side flow channel of the condensate heat exchange component is connected to the liquid phase outlet of the first gas-liquid separation component and the inlet of the second gas-liquid separation component. The gas phase outlet of the second gas-liquid separation component is connected to the bottom of the regeneration tower, and the liquid phase outlet of the second gas-liquid separation component is connected to the top of the regeneration tower.

[0018] In some embodiments, a control system is also included, which is used to control the operation of the components; And / or, the regeneration tower includes a plurality of tower bodies, which are arranged vertically and connected to form the regeneration tower.

[0019] In some embodiments, the pressure inside the regeneration tower is 0.07 MPaG to 0.09 MPaG. Attached Figure Description

[0020] Figure 1 This is a flowchart of a carbon capture system that couples vacuum desorption and a heat pump according to an embodiment of the present invention.

[0021] Figure 2 This is a flowchart of a carbon capture system that couples vacuum desorption and a heat pump, according to another embodiment of the present invention.

[0022] Figure label: 1. Absorption tower; 2. Regeneration tower; 21. First pipeline; 31. Lean solution pipeline; 32. Rich solution pipeline; 33. Lean and rich solution heat exchange components; 4. First heat pump assembly; 41. First heat exchange component; 42. Second heat exchange component; 5. Second heat pump assembly; 51. Third heat exchange component; 52. Fourth heat exchange component; 6. Vacuum pump assembly; 7. Reboiler; 71. Second pipe; 8. Cooling separation assembly; 81. Cooling component; 82. First gas-liquid separation component; 83. Condensate heat exchange component; 84. Second gas-liquid separation component; 85. Pressure reducing valve; 9. Compression component; 91. Third pipe. Detailed Implementation

[0023] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0024] See Figure 1 and Figure 2 The carbon capture system coupled with vacuum desorption and heat pump according to an embodiment of the present invention includes a regeneration tower 2, a vacuum pump assembly 6, a reboiler 7, and a first heat pump assembly 4. The regeneration gas outlet at the top of the regeneration tower 2 is connected to a first pipe 21, and the lean liquid outlet at the bottom of the regeneration tower 2 is connected to a lean liquid pipe 31.

[0025] In the carbon capture system, the lean liquid in absorber 1 reacts with carbon dioxide in the flue gas, absorbing the carbon dioxide to form a rich liquid. This rich liquid, after being fed into regeneration tower 2, can be regenerated by heating to release carbon dioxide and form a lean liquid again. This allows for the circulation of lean and rich liquids between absorber 1 and regeneration tower 2. In this embodiment, regeneration tower 2 is used to desorb the rich liquid (absorbent after carbon dioxide absorption). The desorbed regeneration gas (containing carbon dioxide and water vapor, approximately 95-100°C) enters the first pipe 21 from the top regeneration gas outlet, and can then be compressed and geologically sealed. The desorbed lean liquid (absorbent containing little or no carbon dioxide) enters the lean liquid pipe 31 from the bottom lean liquid outlet of regeneration tower 2, and is then returned to absorber 1.

[0026] Vacuum pump assembly 6 is located in the first pipe 21 to evacuate the inner cavity of regeneration tower 2. This evacuation reduces the pressure inside regeneration tower 2, thereby lowering the temperature required for rich liquid desorption, reducing external steam consumption of reboiler 7, and optimizing energy consumption.

[0027] The reboiler 7 is connected to the regeneration tower 2, and the inlet of the reboiler 7 is connected to the regeneration tower 2 via a second pipe 71. The inlet of the reboiler 7 is connected to the bottom of the regeneration tower 2 via the second pipe 71, thereby heating the absorbent at the bottom of the regeneration tower 2, so as to fully desorb the absorbent and provide heat for the desorption of the rich liquid.

[0028] The first heat pump assembly 4 includes a first heat exchange component 41 and a second heat exchange component 42. The first heat exchange component 41 is connected to the first pipe 21, and the second heat exchange component 42 is connected to the lean liquid pipe 31 or the second pipe 71 to recover the heat of the medium in the first pipe 21 and use it to heat the medium in the lean liquid pipe 31 or the second pipe 71. The first heat exchange component 41 of the first heat pump assembly 4 is connected to the first pipe 21 to absorb a large amount of latent heat carried by the regeneration gas, thereby realizing heat recovery. The second heat exchange component 42 is connected to the lean liquid pipe 31 or the second pipe 71, thereby releasing the recovered heat and using it to heat the lean liquid discharged from the regeneration tower 2 or the absorbent liquid to be entered into the reboiler 7, realizing heat recovery and reuse, reducing the input of external heat sources, and reducing energy consumption.

[0029] In this embodiment of the invention, the vacuum pump assembly 6 can reduce the pressure of the regeneration tower 2, lower the desorption temperature, and reduce the external steam consumption of the reboiler 7 by drawing a vacuum, thereby reducing regeneration energy consumption from the source. The first heat pump assembly 4 recovers the waste heat of the regeneration gas to heat the lean liquid or the absorbent entering the reboiler 7, thereby improving the heat recovery utilization rate and reducing heat waste. The entire system in this embodiment reduces the amount of regeneration steam used and the cost by coupling vacuum desorption and heat pump waste heat recovery, solving the problems of high energy consumption and high cost of carbon capture regeneration in related technologies. This can better enable the large-scale application of chemical absorption carbon capture technology and reduce the cost of carbon capture.

[0030] In some embodiments, the first heat exchange component 41 is a first evaporator, the second heat exchange component 42 is a first condenser, and the first heat pump assembly 4 further includes a first compressor connected between the first evaporator and the first condenser to compress the working fluid discharged from the first evaporator and deliver it to the first condenser.

[0031] In this embodiment, the first heat exchange component 41 is a first evaporator. The first evaporator is connected to the first pipe 21. The heat carried by the regenerated gas can be transferred to the heat pump working fluid in the first evaporator, causing the working fluid to evaporate and vaporize. The vaporized working fluid can enter the first compressor, where it is compressed, increasing its pressure and temperature to become a high-temperature, high-pressure working fluid. After entering the first condenser, the high-temperature, high-pressure working fluid can release heat to the medium (lean liquid) in the lean liquid pipe 31 or the second pipe 71. The working fluid in the first condenser condenses and liquefies itself, thus completing a heat pump cycle and realizing the recovery and cascade utilization of waste heat from the regenerated gas.

[0032] This embodiment achieves efficient heat recovery and transfer through the synergistic action of the first evaporator, the first compressor, and the first condenser. The first compressor can increase the temperature and pressure of the working fluid, thereby ensuring that the recovered waste heat can meet the heating requirements of the lean liquid or the feed to the reboiler 7, improving the heat recovery rate and enhancing practicality. The heat pump cycle structure of this embodiment has high heat exchange efficiency, which can reduce the consumption of external heat sources and lower energy consumption and costs.

[0033] In some embodiments, the carbon capture system coupled with vacuum desorption and heat pump further includes a compression assembly 9 and a second heat pump assembly 5. The compression assembly 9 is connected to a first pipe 21 for recovering carbon dioxide and compressing and liquefying it. The outlet end of the compression assembly 9 is connected to a third pipe 91.

[0034] The second heat pump assembly 5 includes a third heat exchange component 51 and a fourth heat exchange component 52. The third heat exchange component 51 is connected to the third pipe 91, and the fourth heat exchange component 52 is connected to the heat source pipe of the lean liquid pipe 31, the second pipe 71, or the heat source inlet of the reboiler 7, so as to recover the heat of the medium in the third pipe 91 and use it to heat the medium in the lean liquid pipe 31, the second pipe 71, or the heat source pipe.

[0035] In this embodiment, the compression component 9 is connected to the first pipe 21. The compression component 9 can compress the desorbed regeneration gas to achieve the separation, recovery, and liquefaction of carbon dioxide. The liquefied carbon dioxide (or high-pressure carbon dioxide) is transported through the third pipe 91. The medium in the first pipe 21 generates a large amount of heat of compression after being compressed by the compression component 9. Therefore, the heat can be further recovered and utilized by recovering the heat of the medium in the third pipe 91. In this embodiment, the heat can be recovered and utilized by the second heat pump component 5. Specifically, the third heat exchange component 51 is connected to the third pipe 91, absorbs this heat of compression, and transfers it to the working fluid in the second heat pump component 5. The fourth heat exchange component 52 releases the recovered heat of compression into the lean liquid pipe 31, the second pipe 71, or the heat source pipe of the reboiler 7 to heat the medium in the corresponding pipe, thereby realizing the recovery and reuse of the heat of compression.

[0036] In this embodiment, the second heat pump component 5 can cooperate with the first heat pump component 4 to achieve efficient recovery and utilization of heat from the regenerated gas, thereby further improving heat utilization, reducing the use of external heat sources, and reducing energy consumption. This embodiment further enhances the system's heat recovery efficiency and reduces energy waste by recovering the heat of compression generated during the compression process while recovering carbon dioxide. This embodiment uses the heat of compression to heat the lean liquid or the relevant medium in the reboiler 7, which can reduce external steam input, lower regeneration energy consumption, and reduce carbon capture costs. The compression component 9 works in conjunction with the second heat pump component 5 to achieve simultaneous carbon dioxide recovery and energy recovery, improving the system's integration and economy, requiring minimal modification work to the entire system, and offering good practicality.

[0037] In some embodiments, the third heat exchange component 51 is a second evaporator, the fourth heat exchange component 52 is a second condenser, and the second heat pump assembly 5 further includes a second compressor connected between the second evaporator and the second condenser to compress the working fluid discharged from the second evaporator and deliver it to the second condenser.

[0038] In this embodiment, the second evaporator is connected to the third pipe 91, thereby absorbing the heat of compression of the medium in the third pipe 91, causing the heat pump working fluid in the second heat pump assembly 5 to evaporate and vaporize. After being compressed by the second compressor, the vaporized working fluid becomes a high-temperature and high-pressure working fluid, which then enters the second condenser to release heat, which is used to heat the medium in the lean liquid pipe 31, the second pipe 71, or the heat source pipe, thus completing the heat of compression recovery cycle.

[0039] This embodiment can achieve efficient recovery and transfer of compression heat, further reduce external heat source consumption, and realize the cascade utilization of heat. Through the cooperation of the first heat pump component 4 and the second heat pump component 5, the two types of waste heat (regeneration gas waste heat and compression heat) can be transferred to the medium in an orderly manner, avoiding heat waste and improving the overall thermal efficiency of the system. The dual heat pump components work together to better recover the waste heat in the system, further reduce regeneration energy consumption, and optimize the energy-saving effect of the system.

[0040] See Figure 2 Furthermore, in this embodiment, the second heat exchange component 42 and the fourth heat exchange component 52 are connected to the same pipe, and in the medium flow direction of the corresponding pipe, the fourth heat exchange component 52 is located before the second heat exchange component 42.

[0041] When the second heat exchange component 42 (the first condenser in the first heat pump assembly 4) and the fourth heat exchange component 52 (the second condenser in the second heat pump assembly 5) are connected to the same pipeline, the fourth heat exchange component 52 is located before the second heat exchange component 42, so that the medium in the pipeline first passes through the fourth heat exchange component 52 to absorb the heat of compression, and then passes through the second heat exchange component 42 to absorb the waste heat of the regenerated gas, thereby realizing the cascade utilization of heat and improving the heat exchange efficiency.

[0042] For example, both the second heat exchanger 42 and the fourth heat exchanger 52 are connected to the lean liquid pipeline 31.

[0043] See Figure 2 For example, the second heat exchange component 42 and the fourth heat exchange component 52 are both connected to the second pipe 71.

[0044] See Figure 1 For example, the second heat exchange component 42 is connected to the second pipe 71, and the fourth heat exchange component 52 is connected to the heat source pipe of the reboiler 7, which can heat the steam in the heat source pipe and improve the quality of the steam in the reboiler 7.

[0045] In some embodiments, the carbon capture system coupled with vacuum desorption and heat pump further includes an absorption tower 1 and a lean-rich liquid heat exchange assembly 33. The lean liquid inlet of the absorption tower 1 and the lean liquid outlet of the regeneration tower 2 are connected by a lean liquid pipe 31, and the rich liquid outlet of the absorption tower 1 and the rich liquid inlet of the regeneration tower 2 are connected by a rich liquid pipe 32. The cold side flow channel of the lean-rich liquid heat exchange assembly 33 is connected to the rich liquid pipe 32, and the hot side flow channel of the lean-rich liquid heat exchange assembly 33 is connected to the lean liquid pipe 31.

[0046] In this embodiment, the absorption tower 1 absorbs carbon dioxide from the flue gas, producing a rich liquid, which is then transported to the regeneration tower 2 via the rich liquid pipe 32. The lean liquid desorbed in the regeneration tower 2 is transported back to the absorption tower 1 for recycling via the lean liquid pipe 31. Since the temperature of the lean liquid is higher than that of the rich liquid, this embodiment can be equipped with a lean-rich liquid heat exchange assembly 33. The rich liquid (cold side) flows through the cold side channel, and the lean liquid (hot side) flows through the hot side channel, exchanging heat between the two. The residual heat of the lean liquid is transferred to the rich liquid, preheating the rich liquid, while the lean liquid cools down after the heat exchange, which can improve the carbon dioxide adsorption and capture effect in the absorption tower 1.

[0047] This embodiment utilizes the residual heat of the lean liquor to preheat the rich liquor, thereby realizing the recovery and utilization of the heat of the lean liquor, reducing the heat required for the rich liquor to be consumed during the regeneration and desorption process, and further reducing the regeneration energy consumption.

[0048] In this embodiment, the lean and rich liquid heat exchange component 33, the first heat pump component 4, and the second heat pump component 5 work together to realize the heat recovery and reuse of lean liquid and regenerated gas, improve the overall thermal efficiency of the system, reduce energy waste, and have a simple overall structure and low layout cost. This can better reduce the total cost of carbon capture and facilitate low-cost, large-scale application.

[0049] In some embodiments, the reboiler 7 includes at least two heat source lines, the medium in which is used to heat the absorbent flowing into the reboiler 7.

[0050] In this embodiment, the reboiler 7 is provided with at least two heat source pipelines, which can be connected to different heat source media (such as the waste heat recovered by the first heat pump component 4, the compression heat recovered by the second heat pump component 5, external auxiliary steam, etc.). Multiple heat source pipelines can simultaneously input heat into the reboiler 7 to heat the absorbent (the rich liquid that has not been fully desorbed) flowing into the reboiler 7, providing sufficient heat for the desorption of the absorbent.

[0051] This embodiment employs a multi-heat source pipeline design to simultaneously utilize multiple streams of waste heat, further improving the waste heat recovery and utilization rate and reducing the consumption of external auxiliary steam. This embodiment can also flexibly adjust the heat input of each heat source pipeline according to the system's waste heat generation, ensuring stable heating temperature of reboiler 7, guaranteeing the rich liquid desorption effect, avoiding system shutdown due to a single heat source pipeline failure, improving the stability and reliability of system operation, and adapting to power plant peak shaving for steam extraction. It has good application effects and can achieve coordinated operation with other systems, resulting in excellent performance.

[0052] In some embodiments, the carbon capture system coupled with vacuum desorption and a heat pump further includes a cooling separation component 8. The cooling separation component 8 includes a cooling element 81 and a first gas-liquid separation element 82. The cooling element 81 and the first gas-liquid separation element 82 are sequentially disposed in the first pipe 21 and are both located downstream of the first heat exchange element 41. The cooling element 81 is used to cool the medium within the first pipe 21, and the first gas-liquid separation element 82 is used to separate the liquid phase within the first pipe 21 and transport it back to the regeneration tower 2. The cooling element 81 can be a shell-and-tube heat exchanger, which cools the regeneration gas within the first pipe 21 using a cold medium.

[0053] In this embodiment, the regenerated gas in the first pipeline 21 recovers waste heat through the first heat exchange component 41. It contains some water vapor, which can be further cooled by the cooling component 81 to condense the water vapor into liquid water. The cooled gas-liquid mixture enters the first gas-liquid separation component 82 to separate the gas phase (mainly carbon dioxide) from the liquid phase (condensate). The separated liquid phase (condensate) can be transported back to the regeneration tower 2 for circulation, while the gas phase enters the subsequent compression component 9 for carbon dioxide recovery, thus avoiding the generation of a large amount of water in the compression component 9 during carbon dioxide recovery.

[0054] This embodiment can cool and separate the regenerated gas, recover the condensate, achieve water resource recycling, reduce water consumption, and separate the gaseous carbon dioxide with higher purity, facilitating subsequent compression and recovery, improving carbon dioxide recovery efficiency. It also reduces water loss from the absorbent, minimizing subsequent replenishment and consumption. Furthermore, this embodiment prevents condensate from entering the compression assembly 9, reducing wear and malfunctions, improving compression efficiency and effectiveness, extending equipment lifespan, and enhancing the overall economic efficiency of the system.

[0055] In some possible embodiments, the cooling separation assembly 8 further includes a condensate heat exchange component 83 and a second gas-liquid separation component 84. The hot-side flow channel of the condensate heat exchange component 83 is connected to the first pipe 21 and located upstream of the cooling component 81 and the first heat exchange component 41. The cold-side flow channel of the condensate heat exchange component 83 is connected to the liquid phase outlet of the first gas-liquid separation component 82 and the inlet of the second gas-liquid separation component 84. The gas phase outlet of the second gas-liquid separation component 84 is connected to the bottom of the regeneration tower 2, and the liquid phase outlet of the second gas-liquid separation component 84 is connected to the top of the regeneration tower 2. The condensate heat exchange component 83 can be a shell-and-tube heat exchanger, and the condensate in the condensate heat exchange component 83 is heated by the regeneration gas in the first pipe 21.

[0056] In this embodiment, the condensate heat exchange component 83 is connected to the first pipe 21 and located upstream of the cooling component 81 and the first heat exchange component 41. A pressure reducing valve 85 can be installed on the pipe between the condensate heat exchange component 83 and the first gas-liquid separation component 82, thereby facilitating subsequent heat exchange and gas-liquid separation and improving recovery efficiency.

[0057] In this embodiment, the liquid phase (condensate) separated by the first gas-liquid separation component 82 enters the cold side flow channel of the condensate heat exchange component 83, while the regeneration gas in the first pipe 21 enters the hot side flow channel of the condensate heat exchange component 83. Heat exchange occurs between the two, achieving not only cooling of the regeneration gas but also allowing the condensate to absorb heat and increase its temperature. The heated condensate then enters the second gas-liquid separation component 84, where high-temperature carbon dioxide and water vapor (gas phase) and liquid water (liquid phase) are further separated. The separated gas phase can be compressed by a compressor and then transported back to the bottom of the regeneration tower 2, thereby increasing its pressure and serving as stripping steam within the regeneration tower 2. The pressure of the separated gas phase after compressor compression can reach 150 kPa to 200 kPa, allowing it to re-participate in the desorption cycle and serve as a supplementary heat source. The liquid condensate is transported back to the top of the regeneration tower 2 to replenish the water content within the tower, thus maintaining a stable liquid level and operating conditions within the regeneration tower 2.

[0058] This embodiment can utilize the waste heat of the regenerated gas to achieve heat recovery and utilization, while simultaneously performing secondary separation of condensate to achieve condensate circulation, realize water resource recovery, reduce energy consumption and costs, optimize system operating conditions, and maintain the stability of the liquid system.

[0059] In some embodiments, the carbon capture system coupled with vacuum desorption and a heat pump also includes a control system for controlling the operation of each component. In this embodiment, the control system can use preset programs and sensor feedback to control the operating parameters (such as pressure, temperature, flow rate, etc.) of each component, including the vacuum pump assembly 6, the first heat pump assembly 4, the second heat pump assembly 5, the compression assembly 9, and the reboiler 7, in real time. This ensures stable and coordinated operation of each component, maintaining the pressure, desorption temperature, and other operating conditions within the regeneration tower 2 within optimal ranges. The control system achieves automated system control, reducing manual operation, minimizing human error, ensuring long-term stable operation of the system under optimal energy-saving conditions, and further improving energy efficiency.

[0060] Furthermore, the regeneration tower 2 includes multiple tower bodies, which are arranged vertically and connected to form the regeneration tower 2.

[0061] When the regeneration tower 2 is composed of multiple vertically connected tower bodies, each tower body can perform different functions such as pretreatment, desorption, and purification of the rich liquid, thereby improving the desorption efficiency of the rich liquid and the purity of carbon dioxide. The multi-tower structure of this embodiment can improve the desorption efficiency and processing capacity of the regeneration tower 2, adapt to the needs of large-scale carbon capture, and facilitate the maintenance and repair of the equipment, thereby improving the practicality and reliability of the system. During production, different materials and sizes can be selected according to the functions and roles of different sections, thereby better controlling the desorption of the rich liquid and improving the desorption effect.

[0062] In some embodiments, the pressure inside the regeneration tower 2 is from 0.07 MPaG to 0.09 MPaG. For example, the pressure inside the regeneration tower 2 is 0.07 MPaG, 0.075 MPaG, 0.08 MPaG, 0.088 MPaG, or 0.09 MPaG.

[0063] In this embodiment, the vacuum pump assembly 6 precisely controls the pressure inside the regeneration tower 2 within a vacuum range of 0.07 MPaG to 0.09 MPaG. Within this pressure range, the desorption temperature of the rich liquid can be reduced to 80-90 degrees Celsius (compared to the atmospheric pressure of 100-120 degrees Celsius in related technologies), significantly reducing the external steam heat input required by the reboiler 7, while ensuring that the rich liquid can be fully desorbed and guaranteeing carbon dioxide recovery efficiency.

[0064] This embodiment, through the control of the regeneration environment and the arrangement of the heat recovery equipment of the first heat pump component 4 and the second heat pump component 5, can better control the vacuum pressure in the regeneration tower 2, reduce the desorption temperature, reduce external steam consumption, and reduce regeneration energy consumption from the source. The pressure range of 0.07MPaG to 0.09MPaG in this embodiment can not only ensure desorption efficiency and energy saving, but also avoid the increase in equipment investment caused by excessively low pressure and the failure to achieve energy-saving effect by excessively high pressure, thus achieving a balance between economy and practicality.

[0065] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this invention and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0066] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include at least one of that feature. In the description of this invention, "a plurality of" means at least two, such as two, three, etc., unless otherwise explicitly specified.

[0067] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, an electrical connection, or a connection that allows communication between them; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components, unless otherwise explicitly limited. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0068] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can mean that the first feature is in direct contact with the second feature, or that the first feature is in indirect contact with the second feature through an intermediate medium. Furthermore, "above," "over," and "on top" of the second feature can mean that the first feature is directly above or diagonally above the second feature, or simply that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature can mean that the first feature is directly below or diagonally below the second feature, or simply that the first feature is at a lower horizontal level than the second feature.

[0069] In this invention, the terms "one embodiment," "some embodiments," "example," "specific example," or "some examples," etc., refer to a specific feature, structure, material, or characteristic described in connection with that embodiment or example, which is included in at least one embodiment or example of the invention. In this specification, the illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples. Moreover, without contradiction, those skilled in the art can combine and integrate the different embodiments or examples described in this specification, as well as the features of different embodiments or examples.

[0070] Although embodiments of the present invention have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of the present invention.

Claims

1. A carbon capture system coupling vacuum desorption with heat pumps, characterized in that, include: A regeneration tower, wherein the regeneration gas outlet at the top of the regeneration tower is connected to a first pipe, and the lean liquid outlet at the bottom of the regeneration tower is connected to a lean liquid pipe; A vacuum pump assembly, located in the first pipeline, is used to evacuate the interior of the regeneration tower. A reboiler is connected to the regeneration tower, and the inlet of the reboiler is connected to the regeneration tower via a second pipe; A first heat pump assembly includes a first heat exchange component and a second heat exchange component. The first heat exchange component is connected to the first pipe, and the second heat exchange component is connected to the lean liquid pipe or the second pipe to recover heat from the medium in the first pipe and use it to heat the medium in the lean liquid pipe or the second pipe.

2. The carbon capture system coupling vacuum desorption with heat pump of claim 1, wherein, The first heat exchange component is a first evaporator, the second heat exchange component is a first condenser, and the first heat pump assembly further includes a first compressor, which is connected between the first evaporator and the first condenser to compress the working fluid discharged from the first evaporator and deliver it to the first condenser.

3. The carbon capture system coupled with vacuum desorption and heat pump according to claim 1, characterized in that, It also includes a compression assembly and a second heat pump assembly. The compression assembly is connected to the first conduit for recovering and compressing carbon dioxide into liquefaction. The outlet end of the compression assembly is connected to a third conduit. The second heat pump assembly includes a third heat exchange component and a fourth heat exchange component. The third heat exchange component is connected to the third pipe, and the fourth heat exchange component is connected to the heat source pipe of the lean liquid pipe, the second pipe, or the heat source inlet of the reboiler, so as to recover the heat of the medium in the third pipe and use it to heat the medium in the lean liquid pipe, the second pipe, or the heat source pipe.

4. The carbon capture system coupled with vacuum desorption and heat pump according to claim 3, characterized in that, The third heat exchange component is a second evaporator, the fourth heat exchange component is a second condenser, and the second heat pump assembly further includes a second compressor, which is connected between the second evaporator and the second condenser to compress the working fluid discharged from the second evaporator and deliver it to the second condenser. And / or, the second heat exchange component and the fourth heat exchange component are connected to the same pipe, and in the medium flow direction of the corresponding pipe, the fourth heat exchange component is located before the second heat exchange component.

5. The carbon capture system coupled with vacuum desorption and heat pump according to claim 1, characterized in that, It also includes an absorption tower and a lean-rich liquid heat exchange assembly. The lean liquid inlet of the absorption tower and the lean liquid outlet of the regeneration tower are connected through the lean liquid pipeline. The rich liquid outlet of the absorption tower and the rich liquid inlet of the regeneration tower are connected through the rich liquid pipeline. The cold side flow channel of the lean-rich liquid heat exchange assembly is connected to the rich liquid pipeline, and the hot side flow channel of the lean-rich liquid heat exchange assembly is connected to the lean liquid pipeline.

6. The carbon capture system coupled with vacuum desorption and heat pump according to claim 1, characterized in that, The reboiler includes at least two heat source lines, and the medium in the heat source lines is used to heat the absorbent flowing into the reboiler.

7. The carbon capture system coupled with vacuum desorption and heat pump according to claim 1, characterized in that, It also includes a cooling separation component, which includes a cooling component and a first gas-liquid separation component. The cooling component and the first gas-liquid separation component are sequentially arranged in the first pipeline and are both located downstream of the first heat exchange component. The cooling component is used to cool the medium in the first pipeline, and the first gas-liquid separation component is used to separate the liquid phase in the first pipeline and transport it back to the regeneration tower.

8. The carbon capture system coupled with vacuum desorption and heat pump according to claim 7, characterized in that, The cooling separation assembly further includes a condensate heat exchange component and a second gas-liquid separation component. The hot-side flow channel of the condensate heat exchange component is connected to the first pipe and located upstream of the cooling component and the first heat exchange component. The cold-side flow channel of the condensate heat exchange component is connected to the liquid phase outlet of the first gas-liquid separation component and the inlet of the second gas-liquid separation component. The gas phase outlet of the second gas-liquid separation component is connected to the bottom of the regeneration tower, and the liquid phase outlet of the second gas-liquid separation component is connected to the top of the regeneration tower.

9. The carbon capture system coupled with vacuum desorption and heat pump according to any one of claims 1 to 8, characterized in that, It also includes a control system, which is used to control the operation of each component; And / or, the regeneration tower includes a plurality of tower bodies, which are arranged vertically and connected to form the regeneration tower.

10. The carbon capture system coupled with vacuum desorption and heat pump according to any one of claims 1 to 8, characterized in that, The pressure inside the regeneration tower is 0.07 MPaG to 0.09 MPaG.

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