Carbon dioxide capture device and carbon capture system

Abstract

The application discloses a carbon dioxide capturing device and a carbon capturing system, the carbon dioxide capturing device comprising a tower body, a spraying part and a heat exchange part being arranged in the tower body, the heat exchange part having a heat exchange medium circulating therein, the device operating in an absorption mode, the spraying part spraying an absorbent, the absorbent being used to capture carbon dioxide in flue gas, the heat exchange medium in the heat exchange part cooling the absorbent, the device operating in a regeneration mode, the heat exchange medium in the heat exchange part heating the absorbent sprayed by the regenerated spraying part. In the process of cooperating with grid peak shaving, the carbon dioxide capturing device operates in the absorption mode to capture carbon dioxide, so that the emission standard is met, during the non-peak shaving period, the device operates in the regeneration mode to heat and desorb carbon dioxide, so that the device is ensured to operate at any time, and the problem of resource waste caused by shutdown is avoided. Furthermore, only one tower is arranged, so that carbon dioxide capturing and regeneration can be realized, the land occupation area is reduced, and the economic cost is lowered.

Description

Technical Field

[0001] This invention relates to the field of flue gas purification technology, and in particular to a carbon dioxide capture device and a carbon capture system. Background Technology

[0002] A carbon capture power plant (CCP) is a power plant that uses carbon capture technology to capture and treat carbon dioxide emissions. It typically installs absorption towers and regeneration towers to achieve carbon dioxide capture and regeneration. Because the power generation of CCPs fluctuates, they are usually used to assist other types of main power plants in peak shaving. In related technologies, during non-peak shaving periods, the carbon capture system of a CCP shuts down, leading to resource waste. Summary of the Invention

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

[0004] For example, during peak daytime electricity consumption periods, the grid load is high, and carbon capture power plants provide additional power to help the main power plants cope with the load. However, at night, the grid load is low, and the carbon capture power plants do not need to cooperate with the grid. The carbon capture power plants adjust their power generation to a low-load operation state, and the carbon capture system does not need to operate, thus leading to a waste of resources.

[0005] Furthermore, in related technologies, carbon capture systems require at least an absorption tower and a regeneration tower, resulting in a large footprint and high economic costs.

[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 dioxide capture device to solve the problems of resource waste, large footprint, and high economic cost.

[0008] The carbon dioxide capture device of this invention includes a tower body with a gas inlet and a gas outlet. The tower body is provided with a spray element and a heat exchange element. The spray element is used to spray an absorbent, and the heat exchange element has a circulating heat exchange medium to exchange heat between the heat exchange medium and the absorbent.

[0009] The carbon dioxide capture device has an absorption mode and a regeneration mode. In the absorption mode, the spray element sprays an absorbent to capture carbon dioxide in the flue gas entering the tower through the gas inlet. The purified flue gas is discharged from the tower through the gas outlet. The heat exchange medium in the heat exchange element cools the absorbent. In the regeneration mode, the heat exchange medium in the heat exchange element heats and regenerates the absorbent sprayed by the spray element. The regeneration gas generated by heating the absorbent is discharged from the tower through the gas outlet.

[0010] The carbon dioxide capture device of this invention operates in absorption mode during grid peak shaving to capture carbon dioxide and meet emission standards. During non-peak shaving periods, the device operates in regeneration mode to heat and desorb carbon dioxide, thus ensuring continuous operation and avoiding resource waste caused by downtime. Furthermore, only a single tower is needed for both carbon dioxide capture and regeneration, reducing floor space and economic costs.

[0011] In some embodiments, there are multiple spray elements and multiple heat exchange elements, which are arranged alternately at intervals along the vertical direction.

[0012] In some embodiments, the spraying component includes a liquid distribution pipe and a liquid return pipe. The liquid distribution pipe is located inside the tower body and has multiple liquid distribution ports. The liquid return pipe is located outside the tower body, with its inlet connected to the bottom of the tower body and its outlet connected to the liquid distribution pipe.

[0013] In some embodiments, the heat exchanger includes packing and a heat exchange coil, the packing being disposed within the tower body, the heat exchange coil being embedded in the packing, and the heat exchange coil containing a circulating heat exchange medium.

[0014] In some embodiments, a wire mesh demister is provided inside the tower body, and the wire mesh demister is adjacent to the gas outlet.

[0015] Embodiments of the present invention also propose a carbon capture system.

[0016] The carbon capture system of this invention includes an absorbent supply device, a heat exchange medium supply device, and a carbon dioxide capture device as described in any of the above embodiments. The absorbent supply device is connected to the carbon dioxide capture device and is used to supply absorbent to the carbon dioxide capture device. The heat exchange medium supply device is connected to the carbon dioxide capture device and is used to supply heat exchange medium to the carbon dioxide capture device.

[0017] In some embodiments, the carbon dioxide capture device has a cyclical absorption mode, a preheating mode, a regeneration mode, and a precooling mode.

[0018] The carbon dioxide capture device operates in the absorption mode. The absorbent flowing into the carbon dioxide capture device is a lean solution. The carbon dioxide capture device is used to capture carbon dioxide in flue gas using the lean solution. After the lean solution is saturated with carbon dioxide, it becomes a low-temperature rich solution.

[0019] The carbon dioxide capture device operates in the regeneration mode. The absorbent flowing into the carbon dioxide capture device is a rich solution. The carbon dioxide capture device is used to heat and regenerate the rich solution. After heating and regeneration, the rich solution becomes a high-temperature lean solution.

[0020] The carbon dioxide capture device operates in the preheating mode, and the absorbent flowing into the carbon dioxide capture device is a low-temperature rich solution. The carbon dioxide capture device is used to preheat the low-temperature rich solution using a high-temperature lean solution.

[0021] The carbon dioxide capture device operates in the pre-cooling mode, and the absorbent flowing into the carbon dioxide capture device is a high-temperature lean solution. The carbon dioxide capture device is used to pre-cool the high-temperature lean solution using a low-temperature rich solution.

[0022] In some embodiments, the carbon dioxide capture device has multiple units, and at least one of the multiple carbon dioxide capture devices operates the absorption mode, the preheating mode, the regeneration mode, and the precooling mode.

[0023] In some embodiments, a heat exchanger is provided on the return pipe of any two of the carbon dioxide capture devices to allow the low-temperature rich solution and the high-temperature lean solution to exchange heat in the heat exchanger.

[0024] In some embodiments, the heat exchange medium supply device includes a generator set and a cooling tower, the carbon dioxide capture device operates in the absorption mode or the precooling mode, the cooling tower supplies cooling water to the carbon dioxide capture device, the carbon dioxide capture device operates in the regeneration mode or the preheating mode, and the generator set supplies steam to the carbon dioxide capture device. Attached Figure Description

[0025] Figure 1 This is a schematic diagram of a carbon dioxide capture device according to an embodiment of the present invention.

[0026] Figure 2 This is a schematic diagram of a carbon capture system according to an embodiment of the present invention.

[0027] Figure 3 This is a partial schematic diagram of a carbon capture system according to an embodiment of the present invention.

[0028] Figure label:

[0029] 1-Tower body, 101-Gas inlet, 102-Gas outlet, 11-Spraying component, 12-Heat exchanger component, 13-Wire mesh demister, 2-Absorbent supply device, 3-Heat exchange medium supply device, 4-Carbon dioxide capture device, 5-Heat exchanger. Detailed Implementation

[0030] 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.

[0031] The carbon dioxide capture device according to an embodiment of the present invention is described below with reference to the accompanying drawings.

[0032] like Figure 1 As shown, the carbon dioxide capture device 4 of this embodiment includes a tower body 1, which is arranged vertically. The tower body 1 has a gas inlet 101 and a gas outlet 102. The gas inlet 101 is located at the bottom of the tower body 1, and the gas outlet 102 is located at the top of the tower body 1.

[0033] The tower body 1 is equipped with a spray element 11 and a heat exchange element 12. The spray element 11 is used to spray the absorbent, which is an organic amine solution. The heat exchange element 12 has a circulating heat exchange medium so that the heat exchange medium and the absorbent can exchange heat.

[0034] The carbon dioxide capture device 4 of this invention has an absorption mode and a regeneration mode.

[0035] When the device operates in absorption mode in conjunction with grid peak shaving, the spray element 11 sprays absorbent, which is a lean liquid. Flue gas enters the tower body 1 through the gas inlet 101, where the absorbent captures carbon dioxide from the flue gas. The purified flue gas is then discharged from the tower body 1 through the gas outlet 102. Since the carbon dioxide capture process releases heat, the heat exchange medium in the heat exchange element 12 is used to cool the absorbent to prevent temperature rise from affecting the capture effect.

[0036] Compared to absorption towers in related technologies, which require the addition of a refrigeration unit outside the absorption tower to cool the absorbent before returning it to the absorption tower, the carbon dioxide capture device 4 of this embodiment introduces a heat exchange medium into the tower to promptly remove the heat generated during the capture process, thereby improving cooling efficiency and reducing costs.

[0037] During non-peak shaving periods, the unit operates in regeneration mode, with gas inlet 101 closed. The heat exchange medium in heat exchanger 12 is used to heat the absorbent sprayed by regeneration sprayer 11. The absorbent is a rich liquid after adsorbing carbon dioxide. The regeneration gas generated by heating the absorbent is discharged from tower 1 through gas outlet 102.

[0038] Therefore, the carbon dioxide capture device 4 of this embodiment adapts to different operating modes by introducing heat exchange media at different temperatures. During peak shaving operations in conjunction with the power grid, the device operates in absorption mode to capture carbon dioxide and meet emission standards. During off-peak periods, the device operates in regeneration mode to heat and desorb carbon dioxide, thereby ensuring continuous operation and avoiding resource waste caused by downtime. Furthermore, only one tower is needed to achieve carbon dioxide capture and regeneration, reducing the footprint and lowering economic costs.

[0039] In some embodiments, such as Figure 1 As shown, there are multiple spray elements 11 and multiple heat exchange elements 12, and the multiple spray elements 11 and multiple heat exchange elements 12 are arranged alternately and at intervals along the vertical direction.

[0040] It is understood that the carbon dioxide capture device 4 in this embodiment of the invention improves the capture efficiency and effect during the capture process and the regeneration efficiency and effect during the regeneration process by setting a multi-stage spray heat exchange structure.

[0041] In some embodiments, such as Figure 1 As shown, the spray element 11 includes a liquid distribution pipe and a liquid return pipe. The liquid distribution pipe is located inside the tower body 1 and has multiple liquid distribution ports. The liquid return pipe is located outside the tower body 1, with its inlet connected to the bottom of the tower body 1 and its outlet connected to the liquid distribution pipe. The heat exchange element 12 includes packing and a heat exchange coil. The packing is located inside the tower body 1, and the heat exchange coil is embedded in the packing, with a circulating heat exchange medium inside the heat exchange coil.

[0042] The absorbent is transported into tower 1 through the distribution pipe. Due to its own weight, the absorbent falls into the packing, where it indirectly exchanges heat with the heat exchange medium in the heat exchange coil. The absorbent falls to the bottom of tower 1 and is then transported back to the upper middle part of tower 1 via the return pipe, ensuring full recycling.

[0043] Optionally, a pump (not shown in the figure) is provided on the return pipe to drive the liquid flow.

[0044] In some embodiments, such as Figure 1 As shown, a wire mesh demister 13 is installed inside the tower body 1, and the wire mesh demister 13 is adjacent to the gas outlet 102.

[0045] Understandably, the wire mesh demister 13 is used to intercept the gas (flue gas or regeneration gas) carrying the absorbent out of the tower body 1, thereby reducing the loss of the absorbent.

[0046] The carbon capture system of the present invention is described below with reference to the accompanying drawings.

[0047] like Figures 1 to 3As shown, the carbon capture system of this invention includes an absorbent supply device 2, a heat exchange medium supply device 3, and a carbon dioxide capture device 4 as described in any of the above embodiments.

[0048] The absorbent supply device 2 is connected to the carbon dioxide capture device 4, and the absorbent supply device 2 is used to supply absorbent to the carbon dioxide capture device 4. The heat exchange medium supply device 3 is connected to the carbon dioxide capture device 4, and the heat exchange medium supply device 3 is used to supply heat exchange medium to the carbon dioxide capture device 4.

[0049] Optionally, the carbon dioxide capture device 4 has an absorption mode, a preheating mode, a regeneration mode, and a precooling mode for cyclic operation.

[0050] When the carbon dioxide capture device 4 is operating in absorption mode, the absorbent flowing into the carbon dioxide capture device 4 is lean liquid. The carbon dioxide capture device 4 is used to capture carbon dioxide in flue gas using lean liquid. After the lean liquid is saturated with carbon dioxide, it becomes low-temperature rich liquid.

[0051] When the carbon dioxide capture device 4 is in regeneration mode, the absorbent flowing into the carbon dioxide capture device 4 is rich liquid. The carbon dioxide capture device 4 is used to heat and regenerate the rich liquid. After heating and regeneration, the rich liquid becomes high-temperature lean liquid.

[0052] When the carbon dioxide capture device 4 is in preheating mode, the absorbent flowing into the carbon dioxide capture device 4 is a low-temperature rich solution, and the carbon dioxide capture device 4 is used to preheat the low-temperature rich solution using a high-temperature lean solution.

[0053] When the carbon dioxide capture device 4 is in pre-cooling mode, the absorbent flowing into the carbon dioxide capture device 4 is a high-temperature lean solution, and the carbon dioxide capture device 4 is used to pre-cool the high-temperature lean solution using a low-temperature rich solution.

[0054] Understandably, the temperature during the carbon dioxide capture process is lower than the temperature during absorbent regeneration. After capturing carbon dioxide from the flue gas, the carbon dioxide capture device 4 uses the heat from the regenerated absorbent to preheat the saturated absorbent, thereby lowering its temperature. Then, the saturated absorbent is regenerated by heating, thus improving energy efficiency and reducing energy consumption.

[0055] In some embodiments, the carbon dioxide capture device 4 has multiple devices, and at least one of the multiple carbon dioxide capture devices 4 operates in an absorption mode, a preheating mode, a regeneration mode, and a precooling mode.

[0056] It is understood that the carbon dioxide capture device 4 has at least four units. When one unit operates in absorption mode, the other three operate in preheating mode, regeneration mode, and precooling mode, respectively. When the carbon dioxide capture device 4 operating in absorption mode finishes operation, it enters preheating mode. The other carbon dioxide capture devices 4 operating in preheating mode finish operation and enter regeneration mode, and so on, thereby ensuring the continuity of carbon capture.

[0057] Furthermore, compared to carbon capture systems in related technologies, absorption towers only have the function of capturing carbon dioxide, and regeneration towers only have the function of heating and desorbing carbon dioxide. The carbon capture system of this invention can complete both adsorption and regeneration processes in one tower, avoiding the back-and-forth transport of absorbent, reducing the complexity of pipeline connections and control systems, and improving overall operating efficiency.

[0058] In some embodiments, such as Figure 3 As shown, any two carbon dioxide capture devices 4 are equipped with heat exchangers 5 on their return pipes so that the low-temperature rich liquid and the high-temperature lean liquid can exchange heat in the heat exchangers 5.

[0059] It is understandable that by adding a heat exchanger 5 to the circulation pipeline of the carbon dioxide capture device 4 itself, heat exchange between the liquids in the two towers can be achieved. This method is simple to construct and requires less investment.

[0060] In some embodiments, such as Figure 2 As shown, the heat exchange medium supply device 3 includes a generator set and a cooling tower.

[0061] When the carbon dioxide capture device 4 is operating in absorption mode, the cooling tower supplies cooling water to the carbon dioxide capture device 4. When the carbon dioxide capture device 4 is operating in pre-cooling mode, the high-temperature lean solution and the low-temperature rich solution first exchange heat. After the temperature of the lean solution can no longer be lowered by the rich solution, the cooling tower supplies cooling water to the carbon dioxide capture device 4 to reduce the temperature of the lean solution to the temperature required for absorption mode.

[0062] When the carbon dioxide capture device 4 operates in regeneration mode, steam is drawn from the intermediate-pressure cylinder of the generator set and supplied to the carbon dioxide capture device 4 to heat the regenerated absorbent. When the carbon dioxide capture device 4 operates in preheating mode, the low-temperature rich solution and the high-temperature lean solution first exchange heat until the temperature of the rich solution can no longer be raised by the lean solution. Then, the generator set supplies steam to the carbon dioxide capture device 4, and the carbon dioxide capture device 4 switches to regeneration mode.

[0063] 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.

[0064] 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.

[0065] 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.

[0066] 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.

[0067] 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.

[0068] Although the above embodiments have been shown and described, it is understood that the above embodiments are exemplary and should not be construed as limiting the present invention. Any changes, modifications, substitutions and variations made to the above embodiments by those skilled in the art are within the protection scope of the present invention.

Claims

1. A carbon dioxide capture device, characterized in that, The system includes a tower body with a gas inlet and a gas outlet. The tower body is equipped with a spray element and a heat exchange element. The spray element is used to spray the absorbent, and the heat exchange element contains a circulating heat exchange medium to exchange heat between the heat exchange medium and the absorbent. The carbon dioxide capture device has an absorption mode and a regeneration mode. In the absorption mode, the spray element sprays an absorbent to capture carbon dioxide in the flue gas entering the tower through the gas inlet. The purified flue gas is discharged from the tower through the gas outlet. The heat exchange medium in the heat exchange element cools the absorbent. In the regeneration mode, the heat exchange medium in the heat exchange element heats and regenerates the absorbent sprayed by the spray element. The regeneration gas generated by heating the absorbent is discharged from the tower through the gas outlet. During peak shaving operations in coordination with the power grid, the device operates in absorption mode to capture carbon dioxide. During non-peak shaving periods, the device operates in regeneration mode to heat and desorb carbon dioxide.

2. The carbon dioxide capture device according to claim 1, characterized in that, There are multiple spray elements and multiple heat exchange elements, which are arranged alternately and at intervals along the vertical direction.

3. The carbon dioxide capture device according to claim 2, characterized in that, The spraying component includes a liquid distribution pipe and a liquid return pipe. The liquid distribution pipe is located inside the tower body and has multiple liquid distribution ports. The liquid return pipe is located outside the tower body, with its inlet connected to the bottom of the tower body and its outlet connected to the liquid distribution pipe.

4. The carbon dioxide capture device according to claim 2, characterized in that, The heat exchanger includes packing and a heat exchange coil. The packing is disposed in the tower body, and the heat exchange coil is embedded in the packing. The heat exchange coil contains a circulating heat exchange medium.

5. The carbon dioxide capture device according to any one of claims 1-4, characterized in that, The tower body is equipped with a wire mesh demister, which is located near the gas outlet.

6. A carbon capture system, characterized in that, The device includes an absorbent supply device, a heat exchange medium supply device, and a carbon dioxide capture device according to any one of claims 1-5, wherein the absorbent supply device is connected to the carbon dioxide capture device and is used to supply absorbent to the carbon dioxide capture device, and the heat exchange medium supply device is connected to the carbon dioxide capture device and is used to supply heat exchange medium to the carbon dioxide capture device.

7. The carbon capture system according to claim 6, characterized in that, The carbon dioxide capture device has a cyclical absorption mode, a preheating mode, a regeneration mode, and a precooling mode. The carbon dioxide capture device operates in the absorption mode. The absorbent flowing into the carbon dioxide capture device is a lean solution. The carbon dioxide capture device is used to capture carbon dioxide in flue gas using the lean solution. After the lean solution is saturated with carbon dioxide, it becomes a low-temperature rich solution. The carbon dioxide capture device operates in the regeneration mode. The absorbent flowing into the carbon dioxide capture device is a rich solution. The carbon dioxide capture device is used to heat and regenerate the rich solution. After heating and regeneration, the rich solution becomes a high-temperature lean solution. The carbon dioxide capture device operates in the preheating mode, and the absorbent flowing into the carbon dioxide capture device is a low-temperature rich solution. The carbon dioxide capture device is used to preheat the low-temperature rich solution using a high-temperature lean solution. The carbon dioxide capture device operates in the pre-cooling mode, and the absorbent flowing into the carbon dioxide capture device is a high-temperature lean solution. The carbon dioxide capture device is used to pre-cool the high-temperature lean solution using a low-temperature rich solution.

8. The carbon capture system according to claim 7, characterized in that, The carbon dioxide capture device has multiple units, and at least one of the multiple carbon dioxide capture devices operates the absorption mode, the preheating mode, the regeneration mode, and the precooling mode.

9. The carbon capture system according to claim 8, characterized in that, Any two of the carbon dioxide capture devices are equipped with heat exchangers on their return pipes so that the low-temperature rich liquid and the high-temperature lean liquid can exchange heat in the heat exchangers.

10. The carbon capture system according to claim 9, characterized in that, The heat exchange medium supply device includes a generator set and a cooling tower. The carbon dioxide capture device operates in the absorption mode or the precooling mode. The cooling tower supplies cooling water to the carbon dioxide capture device. The carbon dioxide capture device operates in the regeneration mode or the preheating mode. The generator set supplies steam to the carbon dioxide capture device.

Images