A carbon capture peak-shaving coupling device and method

Abstract

The present invention provides a carbon capture peak-shaving coupling device and method, including a renewable energy power generation system, an air carbon capture system and a CO2 compression energy storage system. The air carbon capture system includes an air compression device, a CO2 absorption device, a CO2 regeneration device, and a CO2 gas storage device connected in sequence; the CO2 compression energy storage system includes a second CO2 compression device, a motor unit, a second heat exchange device, a CO2 liquid storage device, an expander, and a generator set connected in sequence. When the renewable energy power generation system has abandoned power output, the air carbon capture system is driven to work, and CO2 is directly captured from the air by chemical absorption. The captured CO2 is stored in the CO2 compression energy storage system by phase change to achieve the purpose of renewable energy power generation peak-shaving, thereby achieving the dual benefits of excess power resource allocation and utilization and CO2 emission reduction.

Description

Technical Field

[0001] The present invention relates to the field of greenhouse gas emission reduction and energy storage technology peak regulation technology, and in particular to a carbon capture peak regulation coupling device and method. Background Art

[0002] With the rapid development of the economy and the continuous improvement of residents' living standards, energy demand has increased rapidly. In the face of global energy shortages and environmental deterioration crises, vigorously developing renewable energy and taking the path of sustainable development has become a global consensus. However, for intermittent renewable energy such as wind power or photovoltaic power generation, their output has strong uncertainty and volatility, and there are problems such as peak load regulation and grid connection difficulties. Taking wind power as an example, during the low power load period, the wind power generation is large, and the "wind abandonment" phenomenon is prominent, resulting in a waste of wind resources; and during the peak power load period, there is a phenomenon of insufficient power supply.

[0003] Global climate change is the biggest threat to human sustainable development. The main goal of addressing climate change is to control CO2 emissions. Industry and the power industry are concentrated and stable sources of CO2 emissions, accounting for about 50% of total CO2 emissions. CO2 capture and storage (CCUS) technology is mainly used to reduce CO2 emissions from these fixed point sources. This technology is a technology with large-scale CO2 emission reduction potential. However, in addition to CO2 emissions from fixed point sources such as industry and the power industry, there are nearly 50% of CO2 emissions from distributed sources. Direct air carbon capture technology can capture and utilize CO2 from these distributed sources. Unlike CCUS technology that captures carbon from coal-fired power plants, direct carbon capture from the air is less restricted by location and can be widely carried out in various places. Moreover, direct carbon capture from the air can reduce the concentration of CO2 in the air and solve the problem of "stock". However, the above-mentioned renewable energy sources have problems such as peak load regulation, grid connection difficulties and urgent greenhouse gas emission reduction during use. Summary of the invention

[0004] Therefore, the technical problem to be solved by the present invention is that the renewable energy in the prior art has problems such as difficulty in peak load regulation, difficulty in grid connection and urgent need for greenhouse gas emission reduction during use.

[0005] To this end, the present invention provides a carbon capture peak-shaving coupling device, comprising: a renewable energy power generation system, an air carbon capture system and a CO2 compression energy storage system;

[0006] The air carbon capture system is suitable for capturing CO2 from the air, and comprises: an air compression device, a CO2 absorption device, a CO2 regeneration device and a CO2 gas storage device; the first end of the air compression device is connected to the outside air, and is suitable for absorbing air from the outside, the second end of the air compression device is connected to the first end of the CO2 absorption device, the second end of the CO2 absorption device is connected to the first end of the CO2 regeneration device, the second end of the CO2 regeneration device is connected to the first end of the CO2 gas storage device, and the fourth end of the CO2 absorption device is connected to the outside, and is suitable for discharging the decarbonized air to the outside;

[0007] The CO2 compression energy storage system comprises: a second CO2 compression device, a motor group, a second heat exchange device, a CO2 liquid storage device, an expander and a generator group; wherein the motor group supplies power to the second CO2 compression device, the expander is suitable for driving the generator group to generate electricity, the first end of the second CO2 compression device is connected to the second end of the CO2 gas storage device, the second end of the second CO2 compression device is connected to the first end of the second heat exchange device, the second end of the second heat exchange device is connected to the first end of the CO2 liquid storage device, and the second end of the CO2 liquid storage device is connected to the third end of the second heat exchange device, the fourth end of the second heat exchange device is connected to the first end of the expander; the second end of the expander is connected to the first end of the CO2 gas storage device;

[0008] The CO2 compression energy storage system has a heat release state in which the CO2 gas outputted by the CO2 gas storage device is compressed and cooled to liquefy into liquid CO2 by a second CO2 compression device, in which the heat energy is stored by the second heat exchange device, and the cooled liquid CO2 is stored in the CO2 liquid storage device by the second heat exchange device;

[0009] The CO2 compression energy storage system also has a power generation state in which the liquid CO2 in the CO2 liquid storage device absorbs the heat energy stored in the second heat exchange device and is decompressed and gasified, and then enters the expander to perform work, so as to drive the generator set to generate electricity through the expander;

[0010] The CO2 compression energy storage system is switched between the heat release state and the power generation state.

[0011] Optionally, in the above-mentioned carbon capture peak-shaving coupling device, the air carbon capture system further comprises:

[0012] The first heat exchange device is arranged between the second end of the CO2 absorption device and the first end of the CO2 regeneration device. The first end of the first heat exchange device is connected to the second end of the CO2 absorption device, and the second end of the first heat exchange device is connected to the first end of the CO2 regeneration device.

[0013] Optionally, in the above-mentioned carbon capture and peak-shaving coupling device, a cold rich liquid pump is further provided between the first end of the first heat exchange device and the second end of the CO2 absorption device;

[0014] The second end of the CO2 absorption device is communicated with the first end of the cold rich liquid pump; the second end of the cold rich liquid pump is communicated with the first end of the first heat exchange device.

[0015] Optionally, in the above-mentioned carbon capture and peak-shaving coupling device, a rich liquid storage device and a hot rich liquid pump are also arranged between the second end of the first heat exchange device and the first end of the CO2 regeneration device; the second end of the first heat exchange device is connected to the first end of the rich liquid storage device, and the second end of the rich liquid storage device is connected to the first end of the CO2 regeneration device.

[0016] Optionally, in the above-mentioned carbon capture and peak-shaving coupling device, a hot lean liquid pump is further provided between the first heat exchange device and the CO2 regeneration device; the first end of the hot lean liquid pump is connected to the third end of the CO2 regeneration device, the second end of the hot lean liquid pump is connected to the third end of the first heat exchange device, and the hot lean liquid pump is suitable for driving the lean liquid to flow from the third end of the CO2 regeneration device to the third end of the first heat exchange device;

[0017] A heating device is also provided between the third end of the CO2 regeneration device and the fourth end of the CO2 regeneration device.

[0018] Optionally, in the above-mentioned carbon capture and peak-shaving coupling device, a lean liquid storage device and a cold lean liquid pump are further provided between the first heat exchange device and the CO2 absorption device;

[0019] The fourth end of the first heat exchange device is connected to the first end of the lean liquid storage device, the second end of the lean liquid storage device is connected to the first end of the cold lean liquid pump, and the second end of the cold lean liquid pump is connected to the third end of the CO2 absorption device.

[0020] Optionally, the above-mentioned carbon capture peak-shaving coupling device,

[0021] The CO2 absorption device is a CO2 absorption tower, in which a CO2 absorbent is arranged;

[0022] The CO2 regeneration device is a CO2 regeneration tower.

[0023] Optionally, in the above-mentioned carbon capture and peak-shaving coupling device, a first CO2 compression device is arranged between the CO2 regeneration device and the CO2 gas storage device, the second end of the CO2 regeneration device is connected to the first end of the first CO2 compression device, and the second end of the first CO2 compression device is connected to the first end of the CO2 gas storage device.

[0024] A carbon capture peak-shaving coupling method, comprising:

[0025] S1: The air compression device absorbs air from the outside, transmits it to the CO2 regeneration device through the CO2 absorption device, and stores it through the CO2 gas storage device;

[0026] S2: The CO2 in the CO2 gas storage device is compressed and cooled to liquefy into liquid CO2, and the second heat exchange device stores the heat energy released during the compression and liquefaction processes, and the cooled liquid CO2 is stored in the CO2 liquid storage device;

[0027] S3: The liquid CO2 in the CO2 liquid storage device absorbs the heat energy stored in the second heat exchange device and is decompressed and gasified, and then enters the expander to perform work, thereby driving the generator set to generate electricity.

[0028] Optionally, the above-mentioned carbon capture and peak-shaving coupling method adopts the above-mentioned carbon capture and peak-shaving coupling device.

[0029] The technical solution provided by the present invention has the following advantages:

[0030] 1. The carbon capture peak-shaving coupling device provided by the present invention utilizes the excess power generation of renewable energy power generation systems such as wind power and solar power plants under favorable power generation conditions to directly capture carbon from the air, and utilizes the captured CO2 for phase change compression and energy storage. Under unfavorable power generation conditions, CO2 is expanded to release energy for power generation, thereby supplementing the insufficient power generation.

[0031] This will effectively resolve the contradiction between excess power generation under favorable power generation conditions and insufficient power generation under unfavorable conditions in renewable energy power plants, and achieve the dual benefits of allocating and utilizing excess power resources and reducing CO2 emissions. It can reduce the concentration of CO2 in the air while achieving peak power generation in renewable energy power plants, thereby improving power generation efficiency and alleviating the greenhouse effect. In addition, the installation of the device is less restricted by location and is suitable for a variety of locations with renewable energy power generation.

[0032] 2. The carbon capture peak-shaving coupling device provided by the present invention can flexibly adjust the operating state of the renewable energy power generation system, so that the net power generation and power generation cost of the unit can be regulated within a certain range, thereby achieving economic benefits.

[0033] 3. The carbon capture and peak-shaving coupling device provided by the present invention compresses the CO2 captured from the air and uses it as an energy storage medium. It has the advantages of high energy storage density, flexible application, economy and environmental protection, and high conversion efficiency. It has good application prospects in the field of fluctuating renewable energy energy storage and peak-shaving.

[0034] 4. The carbon capture peak-shaving coupling device provided by the present invention, the existence of the rich liquid storage device, the lean liquid storage device, the CO2 gas storage device, and the CO2 liquid storage device, independently controls the carbon capture absorption link, the carbon capture analysis link, and the CO2 compression energy storage link, which is beneficial to improving the ability of the integrated system to accept fluctuating new energy sources. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the specific implementation methods of the present invention or the technical solutions in the prior art, the drawings required for use in the specific implementation methods or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are some implementation methods of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 This is a schematic diagram of the structure of the carbon capture and peak-shaving coupling device provided in Example 1;

[0037] Description of reference numerals:

[0038] 1-renewable energy power generation system; 2-air carbon capture system; 3-CO2 compression energy storage system; 4-air compression device; 5-CO2 absorption device; 6-cold rich liquid pump; 7-first heat exchange device; 8-rich liquid storage device; 9-hot rich liquid pump; 10-CO2 regeneration device; 11-heating device; 12-hot lean liquid pump; 13-lean liquid storage device; 14-cold lean liquid pump; 15-first CO2 compression device; 16-CO2 gas storage device; 17-second CO2 compression device; 18-motor unit; 19-second heat exchange device; 20-CO2 liquid storage device; 21-expander; 22-generator unit. DETAILED DESCRIPTION

[0039] The technical solution of the present invention will be described clearly and completely below in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0040] In the description of the present invention, it should be noted that the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc., indicating the orientation or positional relationship, are based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the present invention. In addition, the terms "first", "second", and "third" are used for descriptive purposes only, and cannot be understood as indicating or implying relative importance.

[0041] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two components. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0042] In addition, the technical features involved in the different embodiments of the present invention described below can be combined with each other as long as they do not conflict with each other.

[0043] Example 1

[0044] like Figure 1 As shown, the present invention provides a carbon capture peak-shaving coupling device, including a renewable energy power generation system 1, an air carbon capture system 2 and a CO2 compression energy storage system 3. Among them, the air carbon capture system 2 includes an air compression device 4, a CO2 absorption device 5, a CO2 regeneration device 10 and a CO2 gas storage device 16 connected in sequence; the CO2 compression energy storage system 3 includes a second CO2 compression device 17, a second heat exchange device 19, a CO2 liquid storage device 20 and an expander 21 connected in sequence, the second CO2 compression device 17 is powered by a motor group 18, and the expander 21 drives a generator group 22 to generate electricity.

[0045] In this embodiment, the first end of the air compression device 4 is connected to the outside air and is suitable for absorbing air from the outside. The second end of the air compression device 4 is connected to the first end of the CO2 absorption device 5, the second end of the CO2 absorption device 5 is connected to the first end of the CO2 regeneration device 10, the second end of the CO2 regeneration device 10 is connected to the first end of the CO2 gas storage device 16, and the fourth end of the CO2 absorption device 5 is connected to the outside and is suitable for discharging the decarbonized air to the outside; the first end of the second CO2 compression device 17 is connected to the second end of the CO2 gas storage device 16, the second end of the second CO2 compression device 17 is connected to the first end of the second heat exchange device 19, the second end of the second heat exchange device 19 is connected to the first end of the CO2 liquid storage device 20, and the second end of the CO2 liquid storage device 20 is connected to the third end of the second heat exchange device 19, and the fourth end of the second heat exchange device 19 is connected to the first end of the expander 21; the second end of the expander 21 is connected to the first end of the CO2 gas storage device 16;

[0046] The CO2 compression energy storage system 3 has a heat release state in which the CO2 gas output by the CO2 gas storage device 16 is compressed and cooled to liquefy into liquid CO2 through the second CO2 compression device 17. In the heat release state, the heat energy is stored by the second heat exchange device 19, and the cooled liquid CO2 is stored in the CO2 liquid storage device 20 through the second heat exchange device 19; the CO2 compression energy storage system 3 also has a power generation state in which the liquid CO2 in the CO2 liquid storage device 20 absorbs the heat energy stored in the second heat exchange device 19 and is decompressed and gasified, and then enters the expander 21 to perform work, so as to drive the generator set 22 to generate electricity through the expander 21; the CO2 compression energy storage system 3 is switched between the heat release state and the power generation state.

[0047] The second heat exchange device 19 provided in this embodiment has a CO2 gas inlet, a CO2 liquid outlet, a CO2 liquid inlet and a CO2 gas outlet, corresponding to the first end, the second end, the third end and the fourth end of the second heat exchange device 19.

[0048] The second end of the second CO2 compression device 17 is the outlet of the second CO2 compression device 17, and the first end of the second heat exchange device 19 is the CO2 gas inlet. The second end of the second heat exchange device 19 is the CO2 liquid outlet, and the first end of the CO2 liquid storage device 20 is the CO2 liquid inlet; the fourth end of the second heat exchange device 19 is the CO2 gas outlet, and the first end of the expander 21 is the inlet of the expander 21; the third end of the second heat exchange device 19 is the CO2 liquid inlet, and the second end of the CO2 liquid storage device 20 is the CO2 liquid outlet.

[0049] In this embodiment, the expander 21 is connected to the generator set 22, and the expander 21 drives the generator set 22 to generate electricity; the second end of the expander 21 is the CO2 outlet, and the first end of the CO2 gas storage device 16 is the CO2 inlet, and the CO2 outlet of the expander 21 is connected to the CO2 inlet of the CO2 gas storage device 16 to achieve the purpose of CO2 recycling.

[0050] In this embodiment, the second end of the air compression device 4 is an air outlet, the first end of the CO2 absorption device 5 is an air inlet, the air compression device 4 is an air compressor, the CO2 absorption device 5 is a CO2 absorption tower, and a CO2 absorbent is arranged in the absorption tower. In this embodiment, the CO2 absorbent can be monoethanolamine or mixed amines, and CO2 in the air is captured by the chemical reaction between CO2 and the absorbent.

[0051] In this embodiment, the CO2 regeneration device 10 can be a regeneration tower, and the CO2 rich liquid is analyzed under high temperature in the regeneration tower to release CO2. In this embodiment, the temperature of the rich liquid in the regeneration tower is controlled to be between 110-120°C. In an optional embodiment, the CO2 regeneration device 10 has a rich liquid inlet, a CO2 outlet, a lean liquid inlet and a lean liquid outlet, corresponding to the first end, the second end, the third end and the fourth end of the CO2 regeneration device 10.

[0052] In this embodiment, the CO2 absorption tower and the regeneration tower are both packed towers, using inert metal packings, and the function of the packings is to ensure sufficient contact between the gas and liquid phases.

[0053] In this embodiment, the CO2 gas storage device 16 is a CO2 gas storage tank, the second CO2 compression device 17 is a CO2 compressor, and the CO2 liquid storage device 20 is a CO2 liquid storage tank.

[0054] In this embodiment, the second heat exchange device 19 is a phase change energy storage heat exchange system, which is equipped with a phase change heat storage material for storing the heat energy generated during the compression process of gaseous CO2 and the cooling and liquefaction process and releasing the above heat energy to gasify the liquid CO2.

[0055] The carbon capture peak-shaving coupling device provided by the present invention utilizes the air carbon capture system 2 to directly capture carbon from the air based on the chemical absorption method, and then utilizes the CO2 phase change energy storage in the CO2 compression energy storage system 3 to achieve the purpose of renewable energy power generation peak-shaving. When electricity is abundant, the CO2 in the CO2 gas storage device is compressed and cooled to liquefy into liquid CO2, and the heat energy released by the compression process and the liquefaction process is stored by the phase change energy storage and heat exchange system; when electricity is needed, the liquid CO2 absorbs the heat energy stored in the phase change energy storage and heat exchange system, decompresses and gasifies, and then enters the expander to do work, and the expander drives the generator set to generate electricity, thereby achieving the dual benefits of excess power resource allocation and utilization and CO2 emission reduction.

[0056] In this embodiment, the abandoned electricity generated by the renewable energy power generation system 1 is used to power the air carbon capture system 2 and the CO2 compression energy storage system 3. In this embodiment, the renewable energy power generation system 1 can be a wind power generation system or a photovoltaic power generation system. Of course, in other optional embodiments, the renewable energy power generation system 1 can power any energy-requiring component in the device to provide the required energy. In this embodiment, the renewable energy power generation system 1 is connected to the reboiler to provide heat for the regeneration tower; the renewable energy power generation system 1 is connected to the first CO2 compression device 15 (mentioned below) and the second CO2 compression device 17 to provide power; the expander 21 drives the generator set 22 to generate electricity, and the generated electricity is transmitted to the renewable energy power generation system 1 to supplement the electricity demand.

[0057] A first CO2 compression device 15 is provided between the CO2 regeneration device 10 and the CO2 gas storage device 16, the second end of the CO2 regeneration device 10 is communicated with the first end of the first CO2 compression device 15, and the second end of the first CO2 compression device 15 is communicated with the first end of the CO2 gas storage device 16. In this embodiment, the first CO2 compression device 15 is a CO2 compressor.

[0058] In this embodiment, the air carbon capture system 2 further includes a first heat exchange device 7, which is arranged between the second end of the CO2 absorption device 5 and the first end of the CO2 regeneration device 10. The first end of the first heat exchange device 7 is in communication with the second end of the CO2 absorption device 5, and the second end of the first heat exchange device 7 is in communication with the first end of the CO2 regeneration device 10. A cold rich liquid pump 6 is also arranged between the first end of the first heat exchange device 7 and the second end of the CO2 absorption device 5; the second end of the CO2 absorption device 5 is in communication with the first end of the cold rich liquid pump 6; and the second end of the cold rich liquid pump 6 is in communication with the first end of the first heat exchange device 7.

[0059] In this embodiment, the first heat exchange device 7 is a heat exchanger, and a heat exchanger is connected between the absorption tower and the rich liquid storage tank, which is beneficial to improving energy utilization and reducing costs. The first end of the first heat exchange device 7 is the rich liquid inlet, the second end of the CO2 absorption device 5 is the rich liquid outlet, the second end of the first heat exchange device 7 is the rich liquid outlet, and the first end of the CO2 regeneration device 10 is the rich liquid inlet.

[0060] A rich liquid storage device 8 and a hot rich liquid pump 9 are also provided between the second end of the first heat exchange device 7 and the first end of the CO2 regeneration device 10; the second end of the first heat exchange device 7 is connected to the first end of the rich liquid storage device 8, and the second end of the rich liquid storage device 8 is connected to the first end of the CO2 regeneration device 10. In this embodiment, the rich liquid storage device 8 is a rich liquid storage tank.

[0061] In this embodiment, a hot lean liquid pump 12 is further provided between the first heat exchange device 7 and the CO2 regeneration device 10; the first end of the hot lean liquid pump 12 is connected to the third end of the CO2 regeneration device 10, and the second end of the hot lean liquid pump 12 is connected to the third end of the first heat exchange device 7, and the hot lean liquid pump 12 is suitable for driving the lean liquid to flow from the third end of the CO2 regeneration device 10 to the third end of the first heat exchange device 7; specifically, in this embodiment, the third end of the CO2 regeneration device 10 is the lean liquid outlet, and the third end of the first heat exchange device 7 is the lean liquid inlet.

[0062] In this embodiment, a heating device 11 is provided between the lean liquid outlet and the lean liquid inlet of the CO2 regeneration device 10, wherein a heating device 11 is further provided between the third end of the CO2 regeneration device 10 and the fourth end of the CO2 regeneration device 10. For example, the heating device 11 is a reboiler. The present invention provides a reboiler at the bottom of the regeneration tower, and separates the CO2 in the rich liquid from the absorbent by heating the reboiler.

[0063] A lean liquid storage device 13 and a cold lean liquid pump 14 are also provided between the first heat exchange device 7 and the CO2 absorption device 5; specifically, the fourth end of the first heat exchange device 7 is connected to the first end of the lean liquid storage device 13, the second end of the lean liquid storage device 13 is connected to the first end of the cold lean liquid pump 14, and the second end of the cold lean liquid pump 14 is connected to the third end of the CO2 absorption device 5.

[0064] In this embodiment, the fourth end of the first heat exchange device 7 is a lean liquid outlet, and the third end of the CO2 absorption device 5 is a lean liquid inlet. In this embodiment, the lean liquid storage device 13 is a lean liquid storage tank.

[0065] This embodiment uses the abandoned electricity generated by the renewable energy power generation system 1 to power the air carbon capture system 2 and the CO2 compression energy storage system 3, which not only does not affect the renewable energy power generation system 1, but also effectively solves the peak-shaving problem of renewable energy. In addition, the reserves of renewable energy are abundant, and the impact on the environment during development and utilization is small. The use of fluctuating new energy to drive the carbon capture system to directly capture CO2 from the air can reduce the CO2 content in the air, and no additional CO2 is generated during the carbon capture process, which is one of the important ways to alleviate global climate change. Using CO2 captured from the air as an energy storage medium has the advantages of high energy storage density, flexible application, economic and environmental protection, and high conversion efficiency. It has a good application prospect in the field of fluctuating renewable energy storage peak-shaving. Renewable energy power generation, direct air carbon capture, and CO2 compression energy storage are effectively integrated, and the entire system can operate flexibly. When there is abandoned electricity, the air direct carbon capture and CO2 compression steps are operated, and when the power is insufficient, the CO2 expansion work step is operated. In addition, the presence of the rich liquid storage device, the lean liquid storage device, the CO2 gas storage device, and the CO2 liquid storage device independently controls the carbon capture absorption link, the carbon capture analysis link, and the CO2 compression energy storage link, which is conducive to improving the ability of the integrated system to accept fluctuating new energy sources. The installation of the equipment is less restricted by location and is suitable for a variety of places with renewable energy power generation. That is, the device provided by the present invention integrates the renewable energy power generation system 1, the air carbon capture system 2 and the CO2 compression energy storage system 3 to achieve the coupling of renewable energy driven air direct carbon capture and CO2 compression energy storage for renewable energy power generation peak regulation, which not only solves the peak regulation problem of renewable energy, but also achieves the multiple goals of carbon emission reduction and CO2 resource utilization.

[0066] Example 2

[0067] This embodiment provides a carbon capture and peak-shaving coupling method, comprising the following steps:

[0068] S1: The air compression device 4 draws air from the outside, transmits it to the CO2 regeneration device 10 via the CO2 absorption device 5, and stores it in the CO2 gas storage device 16;

[0069] The air compression device 4 is an air compressor; the CO2 absorption device 5 is a CO2 absorption tower, in which a CO2 absorbent is arranged, and the CO2 absorbent is monoethanolamine; the CO2 regeneration device 10 can be a regeneration tower, in which the CO2 rich liquid is analyzed under high temperature to release CO2, and the temperature of the rich liquid in the regeneration tower is controlled to be 110°C; the CO2 gas storage device 16 is a CO2 storage tank;

[0070] The abandoned electricity in the renewable energy power generation system 1 supplies power to the air carbon capture system 2 and the CO2 compression energy storage system 3; air enters the bottom of the CO2 absorption tower through the air compressor, and the lean liquid from the lean liquid storage tank enters the absorption tower from the top of the tower after passing through the cold lean liquid pump, and the absorbent in the absorption tower contacts the air in reverse, and the absorbent selectively absorbs CO2, and the air after decarbonization is discharged from the top of the absorption tower to the atmosphere, and the rich liquid after absorbing CO2 flows out from the rich liquid outlet at the bottom of the absorption tower, and after heat exchange with the lean liquid from the regeneration tower at the heat exchanger through the cold rich liquid pump, it flows to the rich liquid storage tank for storage;

[0071] S2: The CO2 in the CO2 gas storage device 16 is compressed and cooled to liquefy into liquid CO2, and the second heat exchange device 19 stores the heat energy released during the compression and liquefaction processes, and the cooled liquid CO2 is stored in the CO2 liquid storage device 20;

[0072] When the regeneration tower is working, the rich liquid in the rich liquid storage tank enters the regeneration tower through the hot rich liquid pump for regeneration. A reboiler is provided at the bottom of the tower, which is driven by the renewable energy power generation system 1 to provide heat for the regeneration tower; the lean liquid regenerated from the regeneration tower passes through the hot lean liquid pump and exchanges heat with the cold rich liquid from the absorption tower at the heat exchanger, and then flows to the lean liquid storage tank for continued recycling; the CO2 gas coming out of the top of the regeneration tower enters the CO2 gas storage tank through the CO2 compressor for storage and is used for CO2 compression energy storage; in the CO2 compression energy storage system 3, the CO2 gas in the CO2 gas storage tank is further compressed by the CO2 compressor, and is cooled and liquefied into liquid CO2, and the heat energy released by the compression process and the liquefaction process is stored through the phase change energy storage and heat exchange system;

[0073] S3: The liquid CO2 in the CO2 liquid storage device 20 absorbs the heat energy stored in the second heat exchange device 19 and decompresses and gasifies, then enters the expander 21 to do work, driving the generator set 22 to generate electricity. When electricity is needed, the liquid CO2 absorbs the heat energy stored in the phase change energy storage and heat exchange system, decompresses and gasifies, then enters the expander to do work, and the expander drives the generator set to generate electricity. The CO2 that has done work enters the CO2 gas storage device again for storage to achieve the purpose of recycling.

[0074] In the carbon capture peak-shaving coupling method provided in this embodiment, when the renewable energy power generation system 1 has abandoned power output, the air carbon capture system 2 is driven to work, and carbon dioxide is directly captured from the air by chemical absorption, and the captured carbon dioxide is subjected to phase change compression energy storage in the CO2 compression energy storage system 3. When electricity is needed, the liquid CO2 absorbs the heat energy stored in the phase change energy storage heat exchange system, decompresses and gasifies, and then enters the expander to do work, and the expander drives the generator set to generate electricity.

[0075] Specifically, in the present invention, the abandoned electricity in the renewable energy power generation system 1 is used to supply power to the air carbon capture system 2 and the CO2 compression energy storage system 3; air enters the CO2 absorption tower through the air compressor, and the carbon capture chemical absorbent in the absorption tower, such as monoethanolamine or mixed amines, realizes the selective absorption of CO2, and the rich liquid after absorbing CO2 flows out from the rich liquid outlet at the bottom of the absorption tower and enters the rich liquid storage tank through the heat exchanger; the rich liquid in the rich liquid storage tank is transported to the CO2 regeneration tower through a pipeline for CO2 regeneration, and the regenerated lean liquid flows out from the bottom of the regeneration tower and is transported to the lean liquid storage tank through the heat exchanger for standby; the CO2 gas obtained in the regeneration process is sent to the CO2 gas storage tank through the CO2 compressor. The CO2 gas in the CO2 gas storage tank is further compressed by the CO2 compressor, cooled and liquefied into liquid CO2, and the heat energy released by the compression process and the liquefaction process is stored by the phase change energy storage and heat exchange system; when electricity is needed, that is, in step S3, the liquid CO2 absorbs the heat energy stored in the phase change energy storage and heat exchange system, decompresses and gasifies, and then enters the expander to do work, and the expander drives the generator set to generate electricity. The CO2 that has done work enters the CO2 gas storage device again for storage to achieve the purpose of recycling.

[0076] Based on the direct air carbon capture and CO2 compression energy storage in the above-mentioned device, the renewable energy is peak-shifted: when the renewable energy power generation system 1 has a power output, the air carbon capture system 2 is driven to work, and monoethanolamine is used as a chemical absorbent to directly capture CO2 from the air; in the CO2 compression energy storage system 3, the captured CO2 is subjected to phase change compression energy storage. When electricity is needed, the liquid CO2 absorbs the heat energy stored in the phase change energy storage heat exchange system, decompresses and gasifies, and then enters the expander to do work. The expander drives the generator set to generate electricity for peak shifting.

[0077] Example 3

[0078] This embodiment provides a carbon capture and peak-shaving coupling method, which adopts the carbon capture and peak-shaving coupling device provided in Example 1.

[0079] Example 4

[0080] This embodiment provides a carbon capture and peak-shaving coupling device, which is different from Embodiment 1 in that the renewable energy power generation system 1 is a photovoltaic power generation system, and the chemical absorbent is a mixed amine.

[0081] Obviously, the above embodiments are merely examples for the purpose of clear explanation, and are not intended to limit the implementation methods. For those skilled in the art, other different forms of changes or modifications can be made based on the above description. It is not necessary and impossible to list all the implementation methods here. The obvious changes or modifications derived therefrom are still within the scope of protection of the invention.

Claims

1. A carbon capture peak-shaving coupling device, characterized in that: It includes a renewable energy power generation system, an air carbon capture system and a CO2 compression energy storage system, wherein the abandoned electricity generated by the renewable energy power generation system is used to supply power to the air carbon capture system and the CO2 compression energy storage system; The air carbon capture system is suitable for capturing CO2 from the air, and comprises: an air compression device, a CO2 absorption device, a CO2 regeneration device and a CO2 gas storage device; the first end of the air compression device is connected to the outside air, and is suitable for absorbing air from the outside, the second end of the air compression device is connected to the first end of the CO2 absorption device, the second end of the CO2 absorption device is connected to the first end of the CO2 regeneration device, the second end of the CO2 regeneration device is connected to the first end of the CO2 gas storage device, and the fourth end of the CO2 absorption device is connected to the outside, and is suitable for discharging the decarbonized air to the outside; The CO2 compression energy storage system comprises: a second CO2 compression device, a motor group, a second heat exchange device, a CO2 liquid storage device, an expander and a generator group; wherein the motor group supplies power to the second CO2 compression device, the expander is suitable for driving the generator group to generate electricity, the first end of the second CO2 compression device is connected to the second end of the CO2 gas storage device, the second end of the second CO2 compression device is connected to the first end of the second heat exchange device, the second end of the second heat exchange device is connected to the first end of the CO2 liquid storage device, and the second end of the CO2 liquid storage device is connected to the third end of the second heat exchange device, the fourth end of the second heat exchange device (19) is connected to the first end of the expander; the second end of the expander is connected to the first end of the CO2 gas storage device, and the second heat exchange device is a phase change energy storage heat exchange system; The CO2 compression energy storage system has a heat release state in which the CO2 gas outputted from the CO2 gas storage device is compressed and cooled to liquefy into liquid CO2 by a second CO2 compression device, and the heat energy is stored by the second heat exchange device in the heat release state, and the cooled liquid CO2 is stored in the CO2 liquid storage device by the second heat exchange device; The CO2 compression energy storage system also has a power generation state in which the liquid CO2 in the CO2 liquid storage device absorbs the heat energy stored in the second heat exchange device and is decompressed and gasified, and then enters the expander to perform work, so as to drive the generator set to generate electricity through the expander; The CO2 compression energy storage system is switched between a heat release state and a power generation state; A heating device is also provided between the third end of the CO2 regeneration device and the fourth end of the CO2 regeneration device. The heating device is a reboiler. The reboiler is arranged at the bottom of the regeneration tower and is connected to the renewable energy power generation system to provide heat for the regeneration tower.

2. The carbon capture peak-shaving coupling device according to claim 1, characterized in that: The air carbon capture system also includes: The first heat exchange device is arranged between the second end of the CO2 absorption device and the first end of the CO2 regeneration device. The first end of the first heat exchange device is connected to the second end of the CO2 absorption device, and the second end of the first heat exchange device is connected to the first end of the CO2 regeneration device.

3. The carbon capture peak-shaving coupling device according to claim 2, characterized in that: A cold rich liquid pump is also provided between the first end of the first heat exchange device and the second end of the CO2 absorption device (5); The second end of the CO2 absorption device is communicated with the first end of the cold rich liquid pump; the second end of the cold rich liquid pump is communicated with the first end of the first heat exchange device.

4. The carbon capture peak-shaving coupling device according to claim 3, characterized in that: A rich liquid storage device and a hot rich liquid pump are also provided between the second end of the first heat exchange device and the first end of the CO2 regeneration device; the second end of the first heat exchange device is connected to the first end of the rich liquid storage device, and the second end of the rich liquid storage device is connected to the first end of the CO2 regeneration device.

5. The carbon capture peak-shaving coupling device according to claim 4, characterized in that: A hot lean liquid pump is also provided between the first heat exchange device and the CO2 regeneration device; the first end of the hot lean liquid pump is connected to the third end of the CO2 regeneration device, and the second end of the hot lean liquid pump is connected to the third end of the first heat exchange device, and the hot lean liquid pump is suitable for driving the lean liquid to flow from the third end of the CO2 regeneration device to the third end of the first heat exchange device.

6. The carbon capture peak-shaving coupling device according to claim 5, characterized in that: A lean liquid storage device and a cold lean liquid pump are also provided between the first heat exchange device and the CO2 absorption device; The fourth end of the first heat exchange device is connected to the first end of the lean liquid storage device, the second end of the lean liquid storage device is connected to the first end of the cold lean liquid pump, and the second end of the cold lean liquid pump is connected to the third end of the CO2 absorption device.

7. The carbon capture peak-shaving coupling device according to any one of claims 1 to 6, characterized in that: The CO2 absorption device is a CO2 absorption tower, in which a CO2 absorbent is arranged; The CO2 regeneration device is a CO2 regeneration tower.

8. The carbon capture and peak-shaving coupling device according to any one of claims 1 to 6, characterized in that: A first CO2 compression device is arranged between the CO2 regeneration device and the CO2 gas storage device, the second end of the CO2 regeneration device is connected to the first end of the first CO2 compression device, and the second end of the first CO2 compression device is connected to the first end of the CO2 gas storage device.

9. A carbon capture peak-shaving coupling method, characterized in that: The carbon capture and peak-shaving coupling device according to any one of claims 1 to 8 comprises: S1: The air compression device absorbs air from the outside, transmits it to the CO2 regeneration device through the CO2 absorption device, and stores it through the CO2 gas storage device; S2: The CO2 in the CO2 gas storage device is compressed and cooled to liquefy into liquid CO2, and the second heat exchange device stores the heat energy released during the compression process and the liquefaction process, and the cooled liquid CO2 is stored in the CO2 liquid storage device; S3: The liquid CO2 in the CO2 liquid storage device absorbs the heat energy stored in the second heat exchange device and is decompressed and gasified, and then enters the expander to perform work, thereby driving the generator set to generate electricity.

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