Supercritical carbon dioxide energy storage system based on carbon dioxide capture and energy supplement

Abstract

The invention relates to the technical field of carbon dioxide capture and carbon dioxide energy storage, and discloses a supercritical carbon dioxide energy storage system based on carbon dioxide capture and energy supplementation, which comprises a carbon dioxide capture system, an absorption tower, an energy supplementation system and an energy supplementation system, conveying the mixture into a desorption tower for desorption to regenerate alcohol amine liquid and carbon dioxide; the carbon dioxide energy storage system comprises an energy storage unit and a release unit, and is configured to convey the carbon dioxide in the desorption tower into the energy storage unit to complete the storage process in the energy storage process, and convey the carbon dioxide in the desorption tower into the release unit to complete the release process in the release process; and the release unit absorbs waste heat in the carbon dioxide capture system through the exchange piece. According to the invention, carbon dioxide is captured, sealed and reused, the device has the advantages of high reliability, high cycle efficiency and high energy utilization rate, and a way is provided for solving the greenhouse effect and energy shortage.

Description

Technical Field

[0001] The present invention relates to the technical fields of carbon dioxide capture and carbon dioxide energy storage, and particularly to a supercritical carbon dioxide energy storage system based on carbon dioxide capture and energy supplementation. Background Art

[0002] The massive consumption of global fossil energy has caused serious energy shortages and environmental pollution. As a large-scale physical energy storage technology, carbon dioxide energy storage technology is an important way to achieve the efficient utilization of renewable energy, reduce carbon emissions, solve climate change, and promote the realization of the "dual carbon" goal. However, carbon dioxide energy storage technology still has problems such as low temperature of high-pressure carbon dioxide, low system efficiency, and unstable system operation caused by pressure fluctuations in the gas storage reservoir, and there is an urgent need to improve the system.

[0003] Therefore, there is an urgent need for a supercritical carbon dioxide energy storage system based on carbon dioxide capture and energy supplementation to solve the above problems. Summary of the Invention

[0004] The purpose of the present invention is to provide a supercritical carbon dioxide energy storage system based on carbon dioxide capture and energy supplementation to solve the problems existing in the above-mentioned prior art.

[0005] To achieve the above purpose, the present invention provides the following solution: The present invention provides a supercritical carbon dioxide energy storage system based on carbon dioxide capture and energy supplementation, including:

[0006] A carbon dioxide capture system, including an absorption tower, which is connected to the external industrial flue gas. Carbon dioxide is absorbed by lean amine solution in the absorption tower and then transported to a desorption tower for desorption to regenerate amine solution and carbon dioxide.

[0007] A carbon dioxide energy storage system, including an energy storage unit and a release unit, and is configured such that when in the energy storage process, the carbon dioxide in the desorption tower is transported to the energy storage unit to complete the storage process, and when in the release process, the carbon dioxide in the desorption tower is transported to the release unit to complete the release process, and the release unit absorbs the waste heat in the carbon dioxide capture system through an exchanger.

[0008] According to a supercritical carbon dioxide energy storage system based on carbon dioxide capture and energy supplementation provided by the present invention, the energy storage unit includes:

[0009] A low-pressure injection well and a low-pressure production well, and the carbon dioxide in the desorption tower is transported to the low-pressure production well through the low-pressure injection well;

[0010] A compressor, and the carbon dioxide in the low-pressure production well is compressed to a high-temperature and high-pressure state through a low-pressure throttle valve and the compressor and then injected into a depleted oil and gas reservoir to complete storage.

[0011] A supercritical carbon dioxide energy storage system based on carbon dioxide capture and energy replenishment provided by the present invention, wherein the release unit includes:

[0012] A high-pressure injection well and a high-pressure production well, and carbon dioxide in the desorption tower is sequentially transported to the high-pressure production well through an energy replenishment compressor and the high-pressure injection well;

[0013] An expander, connected to a motor / generator, carbon dioxide in the high-pressure injection well passes through a high-pressure throttle valve and the expander to do work and drive the motor / generator to generate electricity, and the carbon dioxide after doing work is injected into an exhausted oil and gas reservoir to complete the release.

[0014] A supercritical carbon dioxide energy storage system based on carbon dioxide capture and energy replenishment provided by the present invention, wherein the exchanger includes a high-temperature waste heat exchanger, a rich and lean liquid heat exchanger is connected between the absorption tower and the desorption tower, the rich and lean liquid heat exchanger is connected to the high-temperature waste heat exchanger, the high-temperature waste heat exchanger is connected to the absorption tower through an amine solution storage tank, and the high-pressure throttle valve is connected to the expander through the high-temperature waste heat exchanger.

[0015] A supercritical carbon dioxide energy storage system based on carbon dioxide capture and energy replenishment provided by the present invention, wherein a reboiler is provided on the desorption tower, and the reboiler is connected to the rich and lean liquid heat exchanger.

[0016] A supercritical carbon dioxide energy storage system based on carbon dioxide capture and energy replenishment provided by the present invention, wherein a solar collector is connected between the high-temperature waste heat exchanger and the expander.

[0017] A supercritical carbon dioxide energy storage system based on carbon dioxide capture and energy replenishment provided by the present invention, wherein the compressor is connected to the high-pressure injection well.

[0018] A supercritical carbon dioxide energy storage system based on carbon dioxide capture and energy replenishment provided by the present invention, wherein the expander is connected to the low-pressure injection well.

[0019] A supercritical carbon dioxide energy storage system based on carbon dioxide capture and energy replenishment provided by the present invention, wherein carbon dioxide in the desorption tower is compressed by the energy replenishment compressor and then injected into an exhausted oil and gas reservoir.

[0020] Compared with the prior art, the present invention has the following advantages and technical effects:

[0021] A supercritical carbon dioxide energy storage system based on carbon dioxide capture and energy supplementation provided by the present invention. Carbon dioxide discharged from a traditional coal-fired power plant is transported to the bottom of an absorption tower after denitrification and desulfurization. The flue gas at the bottom of the tower is in countercurrent contact with the lean amine solution flowing down from the top of the tower to achieve the absorption of carbon dioxide. Among them, the flue gas from which carbon dioxide has been removed is discharged from the top of the absorption tower, and the rich amine solution is sent to a desorption tower for desorption and regeneration treatment. In the desorption process, the rich solution is decomposed under the action of steam heating in the desorption tower to realize the regeneration of amine and carbon dioxide. The desorbed carbon dioxide enters the desorption tower and is discharged from the top. During the energy storage process, carbon dioxide is injected into a depleted oil and gas reservoir through an energy storage unit for storage, which is the energy storage process of the supercritical carbon dioxide energy storage system. During the release process, carbon dioxide is injected into the depleted oil and gas reservoir after doing work through a release unit to complete the energy release process. At the same time, during the release process, the high-temperature waste heat generated by the carbon dioxide capture system is utilized through a set exchange component. This application captures and stores or utilizes the carbon dioxide emitted industrially, and at the same time utilizes the high-temperature waste heat generated by the carbon dioxide capture system to improve the energy utilization rate, increase the temperature of carbon dioxide, and couple with the supercritical carbon dioxide energy storage system. It can store energy and generate electricity while reducing carbon emissions, and has the advantages of high reliability, high cycle efficiency, and high energy utilization rate, providing a way to solve the greenhouse effect and energy shortage. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the following will briefly introduce the drawings required for use in the embodiments. Obviously, the drawings in the following description are only some embodiments of the present invention. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings:

[0023] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0024] Among them, 1, low-pressure production well; 2, low-pressure throttle valve; 3, compressor; 4, high-pressure injection well; 5, high-pressure production well; 6, high-pressure throttle valve; 7, solar collector; 8, expander; 9, low-pressure injection well; 10, motor / generator; 11, absorption tower; 12, rich and lean liquid heat exchanger; 13, desorption tower; 14, reboiler; 15, high-temperature waste heat exchanger; 16, amine solution storage tank; 17, diverter; 18, energy supplementation compressor. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0025] The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. All other embodiments obtained by those of ordinary skill in the art based on the embodiments of the present invention without creative efforts shall fall within the protection scope of the present invention.

[0026] To make the above objects, features, and advantages of the present invention more obvious and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0027] Refer to Figure 1 , the present invention provides a supercritical carbon dioxide energy storage system based on carbon dioxide capture and energy replenishment, including:

[0028] A carbon dioxide capture system, including an absorption tower 11, which is connected to the external industrial flue gas. Carbon dioxide is absorbed by lean amine solution in the absorption tower 11 and then transported to a desorption tower 13 for desorption to regenerate amine solution and carbon dioxide.

[0029] A carbon dioxide energy storage system, including an energy storage unit and a release unit, and is configured such that when in the energy storage process, the carbon dioxide in the desorption tower 13 is transported to the energy storage unit to complete the storage process, and when in the release process, the carbon dioxide in the desorption tower 13 is transported to the release unit to complete the release process, and the release unit absorbs the waste heat in the carbon dioxide capture system through an exchanger.

[0030] In one embodiment of the present invention, the carbon dioxide discharged from a traditional coal-fired power plant is transported to the bottom of the absorption tower 11 after denitrification and desulfurization. The flue gas at the bottom of the tower is in countercurrent contact with the lean amine solution flowing down from the top of the tower (the amine solution that has not absorbed carbon dioxide is called the lean solution) to achieve the absorption of carbon dioxide. Among them, the flue gas from which carbon dioxide has been removed is discharged from the top of the absorption tower 11, and the rich amine solution is sent to the desorption tower 13 for desorption and regeneration treatment. In the desorption process, the rich solution is decomposed under the action of steam heating in the desorption tower 13 to realize the regeneration of amine and carbon dioxide. The desorbed carbon dioxide enters the desorption tower 13 and is discharged from the top of the tower. During the energy storage process, carbon dioxide is injected into the depleted oil and gas reservoir through the energy storage unit for storage, which is the energy storage process of the supercritical carbon dioxide energy storage system. During the release process, carbon dioxide is injected into the depleted oil and gas reservoir after doing work through the release unit to complete the energy release process. At the same time, during the release process, the high-temperature waste heat generated by the carbon dioxide capture system is utilized through the provided heat exchange component. This application captures the carbon dioxide emitted industrially and stores or utilizes it. At the same time, the high-temperature waste heat generated by the carbon dioxide capture system is utilized to improve the energy utilization rate, increase the temperature of carbon dioxide, and couple with the supercritical carbon dioxide energy storage system. While reducing carbon emissions, it can also store energy and generate electricity, having the advantages of high reliability, high cycle efficiency, and high energy utilization rate, providing a way to solve the greenhouse effect and energy shortage.

[0031] As an alternative embodiment, the energy storage unit includes:

[0032] The low-pressure injection well 9 and the low-pressure production well 1. The carbon dioxide in the desorption tower 13 is transported to the low-pressure production well 1 through the low-pressure injection well 9.

[0033] The compressor 3. The carbon dioxide in the low-pressure production well 1 is compressed to a high-temperature and high-pressure state and injected into the depleted oil and gas reservoir in sequence through the low-pressure throttle valve 2 and the compressor 3 to complete the storage.

[0034] In one embodiment of the present invention, during the energy storage process, during the low electricity consumption period, the supercritical carbon dioxide in the low-pressure production well 1 is released, and the pressure is maintained stable through the low-pressure throttle valve 2. Then the carbon dioxide enters the compressor 3 and is compressed to a high-temperature and high-pressure state and injected into the depleted oil and gas reservoir for storage. This is the energy storage process of the supercritical carbon dioxide energy storage system. While the energy storage process is in progress, the carbon dioxide captured in the carbon dioxide capture system is directly injected into the depleted oil and gas reservoir through the low-pressure injection well 9 to ensure the constant pressure of the depleted oil and gas reservoir, maintain the system stability, and improve the system performance.

[0035] As an alternative embodiment, the release unit includes:

[0036] The high-pressure injection well 4 and the high-pressure production well 5. The carbon dioxide in the desorption tower 13 is transported to the high-pressure production well 5 in sequence through the supplementary energy compressor 18 and the high-pressure injection well 4.

[0037] The expander 8 is connected to an electric motor / generator 10. Carbon dioxide in the high-pressure injection well 4 passes through the high-pressure throttle valve 6 and the expander 8 to do work and drive the electric motor / generator 10 to generate electricity. After doing work, the carbon dioxide is injected into the depleted oil and gas reservoir to complete the release.

[0038] In an embodiment of the present invention, during the energy release process, during the peak electricity consumption period, the high-pressure production well 5 releases high-temperature and high-pressure carbon dioxide. After the pressure is stabilized by the high-pressure throttle valve 6, the high-temperature waste heat of the carbon dioxide capture system is utilized by the high-temperature waste heat exchanger 15, and the temperature of the high-pressure carbon dioxide is further increased by the solar collector 7. Then, the high-temperature and high-pressure carbon dioxide enters the expander 8 to do work and drive the electric motor / generator 10 to generate electricity. After doing work, the carbon dioxide is injected into the depleted oil and gas reservoir by the low-pressure injection well 9 to complete the energy release process.

[0039] As an alternative embodiment, the heat exchanger includes a high-temperature waste heat exchanger 15. A rich / lean liquid heat exchanger 12 is connected between the absorption tower 11 and the desorption tower 13. The rich / lean liquid heat exchanger 12 is connected to the high-temperature waste heat exchanger 15. The high-temperature waste heat exchanger 15 is connected to the absorption tower 11 through the amine solution storage tank 16. The high-pressure throttle valve 6 is connected to the expander 8 through the high-temperature waste heat exchanger 15.

[0040] In an embodiment of the present invention, the amine rich liquid is sent to the desorption tower 13 for desorption and regeneration treatment after heat exchange treatment by the rich / lean liquid heat exchanger 12 (the operating temperature of the absorption tower 11 is lower than that of the desorption tower 13, so it needs to be heated by the rich / lean liquid heat exchanger 12). After desorption, the amine solution is again passed through the rich / lean liquid heat exchanger 12 and the high-temperature waste heat exchanger 15 to cool down to a temperature equivalent to the flue gas temperature and then stored in the amine solution storage tank 16 for recovery. It will be reused when the capture system operates next time. The high-pressure production well 5 releases high-temperature and high-pressure carbon dioxide. After the pressure is stabilized by the high-pressure throttle valve 6, the high-temperature waste heat of the carbon dioxide capture system is utilized by the high-temperature waste heat exchanger 15.

[0041] As an alternative embodiment, a reboiler 14 is provided on the desorption tower 13, and the reboiler 14 is connected to the rich / lean liquid heat exchanger 12.

[0042] In an embodiment of the present invention, the bottom outlet of the desorption tower 13 is connected to the inlet of the reboiler 14, the top outlet of the reboiler 14 is connected to the bottom inlet of the desorption tower 13, and the bottom outlet of the reboiler 14 is connected to the heat source side inlet of the rich / lean liquid heat exchanger 12. Part of the amine solution that has not absorbed carbon dioxide in the desorption tower 13 is discharged through the bottom of the tower and enters the reboiler 14 to be heated again to completely desorb carbon dioxide. The desorbed carbon dioxide enters the desorption tower 13.

[0043] As an alternative embodiment, a solar collector 7 is connected between the high-temperature waste heat exchanger 15 and the expander 8.

[0044] In one embodiment of the present invention, the temperature of the high-pressure carbon dioxide is further increased by the solar collector 7.

[0045] As an alternative embodiment, the compressor 3 is connected to the high-pressure injection well 4.

[0046] In one embodiment of the present invention, carbon dioxide enters the compressor 3 and is compressed to a high-temperature and high-pressure state, and then injected into the depleted oil and gas reservoir through the high-pressure injection well 4 for storage, which is the energy storage process of the supercritical carbon dioxide energy storage system.

[0047] As an alternative embodiment, the expander 8 is connected to the low-pressure injection well 9.

[0048] In one embodiment of the present invention, the high-temperature and high-pressure carbon dioxide enters the expander 8 to perform work and drive the motor / generator 10 to generate electricity. After the work is done, the carbon dioxide is injected into the depleted oil and gas reservoir through the low-pressure injection well 9 to complete the energy release process.

[0049] As an alternative embodiment, the carbon dioxide in the desorption tower 13 is compressed by the energy supplement compressor 18 and then injected into the depleted oil and gas reservoir.

[0050] In one embodiment of the present invention, for the energy storage process, the carbon dioxide in the desorption tower 13 can also be directly compressed by the energy supplement compressor 18 and then injected into the depleted oil and gas reservoir to ensure the constant pressure of the depleted oil and gas reservoir, maintain the system stability, and improve the system performance.

[0051] In the description of the present invention, it should be understood that the orientation or positional relationship indicated by the terms "longitudinal", "transverse", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer", etc. is based on the orientation or positional relationship shown in the drawings, and is only for the convenience of describing the present invention, 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 should not be construed as a limitation to the present invention.

[0052] The above-described embodiments are only descriptions of the preferred embodiments of the present invention, and do not limit the scope of the present invention. Without departing from the design spirit of the present invention, various deformations and improvements made by those of ordinary skill in the art to the technical solutions of the present invention should fall within the protection scope determined by the claims of the present invention.

Claims

1. A supercritical carbon dioxide energy storage system based on carbon dioxide capture and energy replenishment, characterized in that: include: The carbon dioxide capture system comprises an absorption tower (11) which is connected to external industrial flue gas. The carbon dioxide is absorbed by alcohol amine lean liquid in the absorption tower (11) and transported to a desorption tower (13) for desorption to regenerate alcohol amine liquid and carbon dioxide. A carbon dioxide energy storage system comprises an energy storage unit and a release unit, and is configured such that when in the energy storage process, the carbon dioxide in the desorption tower (13) is transported to the energy storage unit to complete the storage process; when in the release process, the carbon dioxide in the desorption tower (13) is transported to the release unit to complete the release process, and the release unit absorbs the waste heat in the carbon dioxide capture system through an exchange element.

2. A supercritical carbon dioxide energy storage system based on carbon dioxide capture and energy replenishment according to claim 1, characterized in that: The energy storage unit comprises: A low-pressure injection well (9) and a low-pressure recovery well (1), wherein the carbon dioxide in the desorption tower (13) is transported to the low-pressure recovery well (1) through the low-pressure injection well (9); Compressor (3), the carbon dioxide in the low-pressure recovery well (1) is compressed to a high-temperature and high-pressure state through a low-pressure throttle valve (2) and the compressor (3) in sequence and injected into the depleted oil and gas reservoir to complete storage.

3. A supercritical carbon dioxide energy storage system based on carbon dioxide capture and energy replenishment according to claim 2, characterized in that: The release unit comprises: A high-pressure injection well (4) and a high-pressure recovery well (5), wherein the carbon dioxide in the desorption tower (13) is transported to the high-pressure recovery well (5) via an energy-replenishing compressor (18) and the high-pressure injection well (4) in sequence; The expander (8) is connected to a motor / generator (10). The carbon dioxide in the high-pressure injection well (4) passes through the high-pressure throttle valve (6) and the expander (8) to perform work and drive the motor / generator (10) to generate electricity. The carbon dioxide after the work is injected into the depleted oil and gas reservoir to complete the release.

4. A supercritical carbon dioxide energy storage system based on carbon dioxide capture and energy replenishment according to claim 3, characterized in that: The exchange element comprises a high-temperature waste heat exchanger (15); a lean-rich liquid heat exchanger (12) is connected between the absorption tower (11) and the desorption tower (13); the lean-rich liquid heat exchanger (12) is connected to the high-temperature waste heat exchanger (15); the high-temperature waste heat exchanger (15) is connected to the absorption tower (11) via an amine solution storage tank (16); and the high-pressure throttle valve (6) is connected to the expander (8) via the high-temperature waste heat exchanger (15).

5. A supercritical carbon dioxide energy storage system based on carbon dioxide capture and energy replenishment according to claim 4, characterized in that: The desorption tower (13) is provided with a reboiler (14), and the reboiler (14) is in communication with the lean-rich liquid heat exchanger (12).

6. A supercritical carbon dioxide energy storage system based on carbon dioxide capture and energy replenishment according to claim 4, characterized in that: A solar collector (7) is connected between the high-temperature waste heat exchanger (15) and the expander (8).

7. A supercritical carbon dioxide energy storage system based on carbon dioxide capture and energy replenishment according to claim 3, characterized in that: The compressor (3) is in communication with the high-pressure injection well (4).

8. A supercritical carbon dioxide energy storage system based on carbon dioxide capture and energy replenishment according to claim 3, characterized in that: The expander (8) is in communication with the low-pressure injection well (9).

9. A supercritical carbon dioxide energy storage system based on carbon dioxide capture and energy replenishment according to claim 3, characterized in that: The carbon dioxide in the desorption tower (13) is compressed by the energy replenishment compressor (18) and then injected into the depleted oil and gas reservoir.

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