Flue gas low temperature purification and carbon capture coupling system

Abstract

The present invention relates to the technical field of flue gas purification and discloses a flue gas low-temperature purification and carbon capture coupling system, including an adsorption tower, a first heat exchanger and an absorption tower. The flue gas low-temperature purification and carbon capture coupling system of the embodiment of the present invention combines the low-temperature adsorption of flue gas with carbon capture. By means of heat exchange, while increasing the temperature of the clean flue gas after low-temperature adsorption, it also reduces the temperature of the clean flue gas after carbon capture discharged from the absorption tower, thereby avoiding the negative impact on carbon capture of the clean flue gas due to the excessively low temperature of the clean flue gas after adsorption, improving the carbon capture efficiency and performance of the absorbent in the absorption tower, and contributing to more efficient carbon capture, while also meeting the discharge temperature of the clean flue gas after carbon capture. The flue gas low-temperature purification and carbon capture coupling system of the present invention can reduce or even avoid the use of an external heat source to heat and raise the temperature of the low-temperature clean flue gas after adsorption, thereby reducing system consumption and saving system operating costs.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon capture, and in particular to a flue gas purification and carbon capture coupling system. Background Art

[0002] The adsorption capacity of the adsorbent increases exponentially in a low-temperature environment, greatly improving the adsorption purification rate compared to conventional high-temperature flue gas adsorption. In related technologies, the flue gas discharged from coal-fired boilers is treated by low-temperature adsorption desulfurization and denitrification, and then the purified flue gas is passed into the CCUS system for carbon capture, utilization and storage to reduce the concentration of carbon dioxide in the atmosphere, thereby mitigating the impact of carbon dioxide on global warming and climate change. Since the flue gas temperature after low-temperature adsorption is very low, below zero degrees, and the suitable temperature for carbon capture absorbents to absorb carbon dioxide is usually around 40°C, if the temperature is too low, the chemical reaction rate of the absorbent will slow down and the absorption efficiency will decrease. Therefore, it is necessary to heat up the flue gas after low-temperature adsorption, which will result in higher overall energy consumption of the system. Summary of the invention

[0003] The present invention aims to solve one of the technical problems in the related art at least to a certain extent. To this end, an embodiment of the present invention provides a low-energy-consumption flue gas low-temperature purification and carbon capture coupling system.

[0004] The flue gas low-temperature purification and carbon capture coupling system of the embodiment of the present invention includes an adsorption tower, a first heat exchanger and an absorption tower, the adsorption tower has a flue gas inlet and a flue gas outlet, the flue gas inlet is used for low-temperature flue gas below zero degrees to enter the adsorption tower, and the flue gas outlet is used to discharge the clean flue gas adsorbed by the adsorption tower; the first heat exchanger has a first hot side inlet, a first hot side outlet, a first cold side inlet and a first cold side outlet, the first cold side inlet is connected to the flue gas outlet to receive the clean flue gas adsorbed by the flue gas outlet; the absorption tower has a smoke inlet and a smoke outlet, the smoke inlet is connected to the first cold side outlet, the smoke outlet is connected to the first hot side inlet, the clean flue gas adsorbed by the smoke outlet is discharged in the first heat exchanger and exchanges heat with the clean flue gas after carbon capture discharged from the smoke outlet, and the clean flue gas after heat exchange is transported to the absorption tower through the first cold side outlet for carbon capture.

[0005] Optionally, the absorption tower has a spray chamber and an absorption chamber arranged in the upper and lower directions, the smoke inlet is connected to the absorption chamber, the smoke outlet is connected to the spray chamber, the absorption chamber is used to capture carbon from the clean flue gas after adsorption and transport the clean flue gas after carbon capture to the spray chamber, the spray chamber is used to spray the clean flue gas after carbon capture, and the smoke outlet is used to discharge the clean flue gas after spraying.

[0006] Optionally, a partition is provided between the spray chamber and the absorption chamber, and a smoke conveying pipe extending in the up and down directions is provided on the partition, and two ends of the smoke conveying pipe are respectively connected to the absorption chamber and the spray chamber, and an air lifting cap is provided on the outlet of the smoke conveying pipe, and the liquid level of the spray liquid in the spray chamber is located below the air lifting cap.

[0007] Optionally, a spray device is provided in the spray chamber, the spray device has a spray liquid inlet and a spray head, and the absorption tower has a spray liquid outlet connected to the spray chamber;

[0008] The flue gas low-temperature purification and carbon capture coupling system also includes a second heat exchanger, which has a second hot side inlet, a second hot side outlet, a second cold side inlet and a second cold side outlet, the second hot side inlet and the second hot side outlet are respectively connected to the spray liquid outlet and the spray liquid inlet, the second cold side inlet and the second cold side outlet are respectively connected to the first cold side outlet and the smoke inlet, and the spray liquid discharged from the spray liquid outlet is transported to the spray liquid inlet after heat exchange with the clean flue gas discharged from the first cold side outlet in the second heat exchanger.

[0009] Optionally, a first pipeline is provided between the second hot side outlet and the spray liquid inlet, and a spray liquid circulation pump is provided on the first pipeline.

[0010] Optionally, a flow control valve is provided on the first pipeline, and the flow control valve is used to control the flow rate of the spray liquid in the first pipeline.

[0011] Optionally, the flue gas low-temperature purification and carbon capture coupling system of the embodiment of the present invention also includes a third heat exchanger and an absorption regeneration tower, the third heat exchanger has a third hot side inlet, a third hot side outlet, a third cold side inlet and a third cold side outlet, the absorption regeneration tower has a rich liquid inlet and a lean liquid outlet, the absorption tower has a lean liquid inlet and a rich liquid outlet, the third hot side inlet and the third hot side outlet are connected to the lean liquid outlet and the lean liquid inlet, respectively, the third cold side inlet and the third cold side outlet are connected to the rich liquid outlet and the rich liquid inlet, respectively, the rich liquid absorbent discharged from the rich liquid outlet is heat exchanged with the lean liquid absorbent discharged from the lean liquid outlet in the third heat exchanger.

[0012] Optionally, the flue gas low-temperature purification and carbon capture coupling system of an embodiment of the present invention also includes a spray cooling tower, which has a hot flue gas inlet and a cold flue gas outlet, and the cold flue gas outlet is connected to the flue gas inlet. The spray cooling tower is used to cool the flue gas to below zero degrees and transport it to the adsorption tower.

[0013] Optionally, the spray cooling tower cools the flue gas to -25°C - -5°C.

[0014] Optionally, the flue gas low-temperature purification and carbon capture coupling system of an embodiment of the present invention further includes an adsorption regeneration tower, which is connected to the adsorption tower and is used to heat, desorb and regenerate the adsorbent saturated with adsorption in the adsorption tower and transport the regenerated adsorbent to the adsorption tower.

[0015] The flue gas low temperature purification and carbon capture coupling system of the present invention combines low temperature adsorption of flue gas with carbon capture. By means of heat exchange, the temperature of the clean flue gas after low temperature adsorption is increased, and the temperature of the clean flue gas after carbon capture discharged from the absorption tower is also reduced, so that the temperature of the clean flue gas after adsorption can be at the optimal absorption temperature of the absorbent, avoiding the negative impact on carbon capture of the clean flue gas due to the excessively low temperature of the clean flue gas after adsorption, improving the carbon capture efficiency and performance of the absorbent in the absorption tower, and contributing to more efficient carbon capture, while also meeting the discharge temperature of the clean flue gas after carbon capture. It can reduce or even avoid the use of an external heat source to heat and raise the temperature of the low temperature clean flue gas after adsorption, reducing system consumption and saving system operating costs. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a flue gas low-temperature purification and carbon capture coupling system according to an embodiment of the present invention.

[0017] Reference numerals:

[0018] 1. Adsorption tower; 101. Smoke inlet; 102. Smoke outlet; 2. First heat exchanger; 201. First hot side inlet; 202. First hot side outlet; 203. First cold side inlet; 204. First cold side outlet; 3. Absorption tower; 301. Smoke inlet; 302. Smoke outlet; 303. Spray chamber; 304. Absorption chamber; 305. Spray liquid outlet; 306. Lean liquid inlet; 307. Rich liquid outlet; 4. Partition; 5. Smoke pipe; 6. Air lift cap; 7. Spray device; 701. Spray liquid inlet; 702. Spray head; 8. Second heat exchanger; 80 1. Second hot side inlet; 802. Second hot side outlet; 803. Second cold side inlet; 804. Second cold side outlet; 9. First pipeline; 10. Spray liquid circulation pump; 11. Flow control valve; 12. Third heat exchanger; 1201. Third hot side inlet; 1202. Third hot side outlet; 1203. Third cold side inlet; 1204. Third cold side outlet; 13. Absorption regeneration tower; 1301. Rich liquid inlet; 1302. Lean liquid outlet; 14. Spray cooling tower; 1401. Hot flue gas inlet; 1402. Cold flue gas outlet; 15. Adsorption regeneration tower. DETAILED DESCRIPTION

[0019] Embodiments of the present invention are described in detail below, and examples of the embodiments are shown in the accompanying drawings. The embodiments described below with reference to the accompanying drawings are exemplary and intended to be used to explain the present invention, but should not be understood as limiting the present invention.

[0020] like Figure 1 As shown, the flue gas low temperature purification and carbon capture coupling system of the embodiment of the present invention includes an adsorption tower 1, a first heat exchanger 2 and an absorption tower 3. The adsorption tower 1 has a flue gas inlet 101 and a flue gas outlet 102. The flue gas inlet 101 is used for low temperature flue gas below zero degrees to enter the adsorption tower 1, and the flue gas outlet 102 is used to discharge the clean flue gas adsorbed by the adsorption tower 1. The first heat exchanger 2 has a first hot side inlet 201, a first hot side outlet 202, a first cold side inlet 203 and a first cold side outlet 204. The first cold side inlet 203 is connected to the flue gas outlet 102 to receive the clean flue gas after adsorption discharged from the flue gas outlet 102.

[0021] The absorption tower 3 has a smoke inlet 301 and a smoke outlet 302. The smoke inlet 301 is connected to the first cold side outlet 204, and the smoke outlet 302 is connected to the first hot side inlet 201. The clean flue gas after adsorption discharged from the smoke outlet 102 is heat exchanged with the clean flue gas after carbon capture discharged from the smoke outlet 302 in the first heat exchanger 2. After the heat exchange, the clean flue gas after adsorption is transported to the absorption tower 3 through the first cold side outlet 204 for carbon capture.

[0022] When the flue gas low-temperature purification and carbon capture coupling system of the embodiment of the present invention is working, the low-temperature flue gas first enters the adsorption tower 1, and pollutants such as SO and NOx in the flue gas are removed by the adsorbent in the adsorption tower 1. The low-temperature clean flue gas after adsorption and purification is discharged through the flue gas outlet 102. The low-temperature clean flue gas discharged from the flue gas outlet 102 enters the first heat exchanger 2 through the first cold side inlet 203.

[0023] The clean flue gas after the carbon capture agent in the absorption tower 3 is discharged through the smoke outlet 302, and enters the first heat exchanger 2 through the first hot side inlet 201. The clean flue gas after carbon capture entering the first heat exchanger 2 exchanges heat with the clean flue gas after adsorption entering the first heat exchanger 2. The temperature of the clean flue gas after adsorption increases and is discharged through the first cold side outlet 204, and then enters the absorption tower 3 through the smoke inlet 301 for carbon capture. The clean flue gas after carbon capture in the first heat exchanger 2 has a lower temperature after heat exchange, and is then discharged to the atmosphere through the first hot side outlet 202.

[0024] The flue gas low temperature purification and carbon capture coupling system of the embodiment of the present invention combines the low temperature adsorption of flue gas with carbon capture. By means of heat exchange, the temperature of the clean flue gas after low temperature adsorption is increased, and the temperature of the clean flue gas after carbon capture discharged from the absorption tower 3 is also reduced, so that the temperature of the clean flue gas after adsorption can be at the optimal absorption temperature of the absorbent, avoiding the negative impact on the carbon capture of the clean flue gas caused by the excessively low temperature of the clean flue gas after adsorption, improving the carbon capture efficiency and performance of the absorbent in the absorption tower 3, and contributing to more efficient carbon capture, while also meeting the discharge temperature of the clean flue gas after carbon capture. It can reduce or even avoid the use of external heat sources to heat and heat the low temperature clean flue gas after adsorption, reduce system consumption, and save system operating costs.

[0025] In some embodiments, the absorption tower 3 has a spray chamber 303 and an absorption chamber 304 arranged in the up-down direction, the smoke inlet 301 is connected to the absorption chamber 304, and the smoke outlet 302 is connected to the spray chamber 303. The absorption chamber 304 is used to capture carbon from the clean flue gas after adsorption and transport the clean flue gas after carbon capture to the spray chamber 303, the spray chamber 303 is used to spray the clean flue gas after carbon capture, and the smoke outlet 302 is used to discharge the clean flue gas after spraying.

[0026] The clean flue gas after carbon capture in the absorption chamber 304 is transported to the spray chamber 303, which is used to spray the clean flue gas after carbon capture, and the clean flue gas after spraying is discharged into the atmosphere through the smoke outlet 302. The spray chamber 303 sprays the clean flue gas mainly for the following two purposes: on the one hand, the clean flue gas is cooled to the discharge temperature, and on the other hand, the absorbent in the clean flue gas is sprayed out to prevent the absorbent from entering the atmosphere with the clean flue gas and polluting the atmosphere.

[0027] In some embodiments, a partition 4 is provided between the spray chamber 303 and the absorption chamber 304, and a smoke conveying pipe 5 extending in the up and down directions is provided on the partition 4. The two ends of the smoke conveying pipe 5 are respectively connected to the absorption chamber 304 and the spray chamber 303. An air lifting cap 6 is provided on the outlet of the smoke conveying pipe 5, and the liquid level of the spray liquid in the spray chamber 303 is located below the air lifting cap 6.

[0028] The smoke absorbed in the absorption chamber 304 enters the smoke conveying pipe 5 and passes through the gas lifting cap 6 to the spray chamber 303. The gas lifting cap 6 can also block the spray liquid while exhausting smoke to prevent the spray liquid from flowing into the absorption chamber 304 through the smoke conveying pipe 5 and affecting the absorbent. During the spraying process, the liquid level of the spray liquid needs to be controlled to prevent the spray liquid from being too high and flooding the smoke conveying pipe 5, causing the spray liquid to enter the absorption chamber 304 through the smoke conveying pipe 5, which is conducive to improving the working reliability of the absorption tower 3.

[0029] In some embodiments, a spray device 7 is provided in the spray chamber 303 , the spray device 7 has a spray liquid inlet 701 and a spray head 702 , and the absorption tower 3 has a spray liquid outlet 305 connected to the spray chamber 303 .

[0030] The flue gas low temperature purification and carbon capture coupling system of the embodiment of the present invention further includes a second heat exchanger 8, which has a second hot side inlet 801, a second hot side outlet 802, a second cold side inlet 803, and a second cold side outlet 804. The second hot side inlet 801 and the second hot side outlet 802 are respectively connected to the spray liquid outlet 305 and the spray liquid inlet 701, the second cold side inlet 803 and the second cold side outlet 804 are respectively connected to the first cold side outlet 204 and the smoke inlet 301, and the spray liquid discharged from the spray liquid outlet 305 is transported to the spray liquid inlet 701 after heat exchange with the clean flue gas discharged from the first cold side outlet 204 in the second heat exchanger 8.

[0031] It should be noted that, since the temperature of the spray liquid will rise after spraying the clean flue gas after absorption, the spray liquid needs to be continuously cooled. In the embodiment of the present invention, the spray liquid in the spray chamber 303 flows out through the spray liquid outlet 305 and enters the second heat exchanger 8 through the second hot side inlet 801, and the clean flue gas after heat exchange and temperature increase discharged from the first cold side outlet 204 enters the second heat exchanger 8 through the second cold side inlet 803 to exchange heat with the spray liquid. The spray liquid after heat exchange and temperature reduction is discharged through the second hot side outlet 802, and enters the spray device 7 through the spray liquid inlet 701, and then the nozzle 702 sprays the flue gas in the spray chamber 303. The clean flue gas after heat exchange and temperature increase is discharged through the second cold side outlet 804 and enters the absorption tower 3 through the smoke inlet 301.

[0032] Therefore, the flue gas low temperature purification and carbon capture coupling system of the embodiment of the present invention realizes low temperature adsorption and carbon capture of flue gas through the second heat exchanger 8, and the clean flue gas and the spray liquid are subjected to secondary heat exchange after the primary heat exchange. While the clean flue gas is heated for the second time, the spray liquid can also be cooled, so that the spray liquid is always at the optimal spraying temperature, and the cascade utilization of the cold capacity in the clean flue gas is realized. It can avoid using an external cold source to cool the spray liquid and using an external heat source to heat the flue gas, which further helps to reduce the energy consumption of the system and reduce the system operation cost.

[0033] In some embodiments, a first pipeline 9 is provided between the second hot side outlet 802 and the spray liquid inlet 701, and a spray liquid circulation pump 10 is provided on the first pipeline 9. The provision of the spray liquid circulation pump 10 also ensures that the spray liquid can be continuously circulated, reduces the operating cost of the system, and meets the requirements of environmental protection and energy saving.

[0034] In some embodiments, a flow control valve 11 is provided on the first pipeline 9 , and the flow control valve 11 is used to control the flow rate of the spray liquid in the first pipeline 9 .

[0035] Specifically, the flow control valve 11 can adjust the flow of the spray liquid so that it can fully exchange heat in the second heat exchanger 8, and then return to the spray chamber 303 to continue spraying the flue gas. By setting the flow control valve 11, the system can adjust the flow of the spray liquid according to the actual operation requirements, thereby improving the spray heat exchange efficiency. At the same time, the flow control valve 11 can also help the system maintain stable operation under different working conditions and optimize the performance of the entire system.

[0036] In some embodiments, the flue gas low temperature purification and carbon capture coupling system of the embodiment of the present invention further includes a third heat exchanger 12 and an absorption regeneration tower 13, the third heat exchanger 12 has a third hot side inlet 1201, a third hot side outlet 1202, a third cold side inlet 1203 and a third cold side outlet 1204, the absorption regeneration tower 13 has a rich liquid inlet 1301 and a lean liquid outlet 1302, and the absorption tower 3 has a lean liquid inlet 306 and a rich liquid outlet 307. The third hot side inlet 1201 and the third hot side outlet 1202 are connected to the lean liquid outlet 1302 and the lean liquid inlet 306, respectively, the third cold side inlet 1203 and the third cold side outlet 1204 are connected to the rich liquid outlet 307 and the rich liquid inlet 1301, respectively, and the rich liquid absorbent discharged from the rich liquid outlet 307 is heat-exchanged with the lean liquid absorbent discharged from the lean liquid outlet 1302 in the third heat exchanger 12.

[0037] The flue gas low-temperature purification and carbon capture coupling system of the embodiment of the present invention can realize energy recovery and utilization by setting a third heat exchanger 12 to exchange heat between the rich liquid absorbent discharged from the absorption tower and the lean liquid absorbent discharged from the absorption regeneration tower, thereby further saving system energy consumption and reducing system operating costs.

[0038] In some embodiments, the flue gas low-temperature purification and carbon capture coupling system of the embodiment of the present invention also includes a spray cooling tower 14, the spray cooling tower 14 has a hot flue gas inlet 1401 and a cold flue gas outlet 1402, the cold flue gas outlet 1402 is connected to the flue gas inlet 101, and the spray cooling tower 14 is used to cool the flue gas to below zero degrees and transport it to the adsorption tower 1.

[0039] Through research, the inventors found that the lower the flue gas temperature, the more beneficial it is for adsorption purification. The flue gas discharged from the coal-fired boiler is cooled to low-temperature flue gas below zero degrees, so that the adsorbent can adsorb the flue gas at low temperature, improve the adsorption effect, and achieve near-zero emissions.

[0040] Specifically, the spray cooling tower 14 receives hot flue gas from the boiler flue through the hot flue gas inlet 1401. In the spray cooling tower 14, the hot flue gas exchanges heat with the cooling water or cold air in the spray cooling tower 14, so that the flue gas temperature is reduced. This process is achieved through a spray system, which sprays a cooling medium, such as water or cold air, into the flue gas. While the flue gas rises in the tower, it is fully in contact with the cooling medium, thereby achieving cooling. The temperature of the cooled flue gas drops below zero, which can condense the water vapor in the flue gas, thereby reducing the influence of water vapor on the adsorbent performance in the subsequent adsorption process.

[0041] The flue gas cooled to below zero degrees is then transported to an adsorption tower 1, which is filled with adsorbents such as activated carbon or other adsorption materials. These adsorbents can capture pollutants such as SO and NOx in the flue gas, thereby achieving near-zero emissions of flue gas pollutants.

[0042] Optionally, the spray cooling tower 14 cools the flue gas to -25°C - 5°C. Although the lower the flue gas temperature, the more beneficial it is for adsorption purification, if the flue gas temperature is too low, it will lead to higher requirements for the structure of the spray cooling tower 14 and the adsorption tower 1. For example, the pipeline sealing between the spray cooling tower 14 and the adsorption tower 1 is required to be high, which will increase the cost and energy consumption. Therefore, it is beneficial to cool the flue gas temperature to -25°C - 5°C.

[0043] In some embodiments, the flue gas low-temperature purification and carbon capture coupling system of the embodiment of the present invention also includes an adsorption regeneration tower 15, which is connected to the adsorption tower 1, and is used to heat and desorb the adsorbent saturated in the adsorption tower 1 and regenerate the regenerated adsorbent and transport it to the adsorption tower 1.

[0044] Specifically, the adsorption tower 1 is used to capture nitrogen oxides or sulfides in the flue gas, and the adsorbent (such as activated carbon) therein can adsorb nitrogen oxides or sulfides in the flue gas. However, as time goes by, the adsorbent will reach a saturated state and can no longer effectively adsorb nitrogen oxides or sulfides in the flue gas.

[0045] At this time, the role of the adsorption regeneration tower 15 becomes apparent. The adsorption regeneration tower 15 is connected to the adsorption tower 1, and is usually equipped with a heating device inside, which is used to heat the saturated adsorbent to a certain temperature to release the nitrogen oxides and sulfides on the adsorbent. This process is called desorption or regeneration. The adsorbent after desorption becomes "clean" and can be reused.

[0046] The regenerated adsorbent is transported from the bottom of the adsorption regeneration tower 15 back to the top of the adsorption tower 1, usually through a transport system at the bottom of the adsorption regeneration tower 15. In this way, the adsorbent can re-enter the adsorption process and continue to capture nitrogen oxides and sulfides in the flue gas. This design allows the adsorbent to be recycled, greatly improving the efficiency and economic sustainability of the system.

[0047] In the description of the present invention, it is to be understood that the terms “center”, “longitudinal”, “lateral”, “length”, “width”, “thickness”, “up”, “down”, “front”, “back”, “left”, “right”, “vertical”, “horizontal”, “top”, “bottom”, “inside”, “outside”, “clockwise”, “counterclockwise”, “axial”, “radial”, “circumferential”, etc., indicating orientations or positional relationships based on the orientations or positional relationships shown in the accompanying drawings, are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as limiting the present invention.

[0048] In addition, the terms "first" and "second" are used for descriptive purposes only and should not be understood as indicating or implying relative importance or implicitly indicating the number of the indicated technical features. Therefore, the features defined as "first" and "second" may explicitly or implicitly include at least one of the features. In the description of the present invention, the meaning of "plurality" is at least two, such as two, three, etc., unless otherwise clearly and specifically defined.

[0049] In the present invention, unless otherwise clearly specified and limited, the terms "installed", "connected", "connected", "fixed" and the like should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection, an electrical connection, or communication with each other; it can be a direct connection, or an indirect connection through an intermediate medium, it can be the internal connection of two elements or the interaction relationship between two elements, unless otherwise clearly defined. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0050] In the present invention, unless otherwise clearly specified and limited, a first feature being "above" or "below" a second feature may mean that the first and second features are in direct contact, or the first and second features are in indirect contact through an intermediate medium. Moreover, a first feature being "above", "above" or "above" a second feature may mean that the first feature is directly above or obliquely above the second feature, or simply means that the first feature is higher in level than the second feature. A first feature being "below", "below" or "below" a second feature may mean that the first feature is directly below or obliquely below the second feature, or simply means that the first feature is lower in level than the second feature.

[0051] In the present invention, the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. mean that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the described specific features, structures, materials or characteristics may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0052] Although the above embodiments have been shown and described, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations on the present invention. Changes, modifications, substitutions and variations of the above embodiments by those of ordinary skill in the art are all within the scope of protection of the present invention.

Claims

1. A flue gas low temperature purification and carbon capture coupling system, characterized in that: include: An adsorption tower, wherein the adsorption tower has a flue gas inlet and a flue gas outlet, wherein the flue gas inlet is used for low-temperature flue gas below zero degrees to enter the adsorption tower, and the flue gas outlet is used for discharging clean flue gas after adsorption by the adsorption tower; a first heat exchanger, the first heat exchanger having a first hot side inlet, a first hot side outlet, a first cold side inlet and a first cold side outlet, wherein the first cold side inlet is connected to the flue gas outlet to receive the adsorbed clean flue gas discharged from the flue gas outlet; An absorption tower, the absorption tower having a smoke inlet and a smoke outlet, the smoke inlet being connected to the first cold side outlet, the smoke outlet being connected to the first hot side inlet, the clean smoke after adsorption discharged from the smoke outlet being heat exchanged in the first heat exchanger with the clean smoke after carbon capture discharged from the smoke outlet, and the clean smoke after adsorption being heat exchanged is transported to the absorption tower through the first cold side outlet for carbon capture; A spray cooling tower, wherein the spray cooling tower has a hot flue gas inlet and a cold flue gas outlet, wherein the cold flue gas outlet is connected to the flue gas inlet, and the spray cooling tower is used to cool the flue gas to below zero degrees and transport it to the adsorption tower; An adsorption regeneration tower, which is in communication with the adsorption tower and is used to heat and desorb the adsorbent saturated with adsorption in the adsorption tower and regenerate the adsorbent and transport the regenerated adsorbent to the adsorption tower; The absorption tower comprises a spray chamber and an absorption chamber arranged in the up-down direction, the smoke inlet is connected with the absorption chamber, the smoke outlet is connected with the spray chamber, the absorption chamber is used for carbon capture of the clean flue gas after adsorption and transporting the clean flue gas after carbon capture to the spray chamber, the spray chamber is used for spraying the clean flue gas after carbon capture, and the smoke outlet is used for discharging the clean flue gas after spraying.

2. The flue gas low temperature purification and carbon capture coupling system according to claim 1 is characterized in that: A partition is provided between the spray chamber and the absorption chamber, and a smoke conveying pipe extending in the up-down direction is provided on the partition. Two ends of the smoke conveying pipe are respectively connected with the absorption chamber and the spray chamber, and an air lifting cap is provided on the outlet of the smoke conveying pipe. The liquid level of the spray liquid in the spray chamber is located below the air lifting cap.

3. The flue gas low temperature purification and carbon capture coupling system according to claim 2 is characterized in that: A spray device is provided in the spray chamber, the spray device has a spray liquid inlet and a spray head, and the absorption tower has a spray liquid outlet connected to the spray chamber; The flue gas low-temperature purification and carbon capture coupling system also includes a second heat exchanger, which has a second hot side inlet, a second hot side outlet, a second cold side inlet and a second cold side outlet, the second hot side inlet and the second hot side outlet are respectively connected to the spray liquid outlet and the spray liquid inlet, the second cold side inlet and the second cold side outlet are respectively connected to the first cold side outlet and the smoke inlet, and the spray liquid discharged from the spray liquid outlet is transported to the spray liquid inlet after heat exchange with the clean flue gas discharged from the first cold side outlet in the second heat exchanger.

4. The flue gas low temperature purification and carbon capture coupling system according to claim 3 is characterized in that: A first pipeline is provided between the second hot side outlet and the spray liquid inlet, and a spray liquid circulation pump is provided on the first pipeline.

5. The flue gas low temperature purification and carbon capture coupling system according to claim 4 is characterized in that: A flow control valve is provided on the first pipeline, and the flow control valve is used to control the flow of the spray liquid in the first pipeline.

6. The flue gas low temperature purification and carbon capture coupling system according to claim 1, characterized in that: It also includes a third heat exchanger and an absorption regeneration tower, the third heat exchanger has a third hot side inlet, a third hot side outlet, a third cold side inlet and a third cold side outlet, the absorption regeneration tower has a rich liquid inlet and a lean liquid outlet, the absorption tower has a lean liquid inlet and a rich liquid outlet, the third hot side inlet and the third hot side outlet are connected to the lean liquid outlet and the lean liquid inlet respectively, the third cold side inlet and the third cold side outlet are connected to the rich liquid outlet and the rich liquid inlet respectively, the rich liquid absorbent discharged from the rich liquid outlet is heat exchanged with the lean liquid absorbent discharged from the lean liquid outlet in the third heat exchanger.

7. The flue gas low temperature purification and carbon capture coupling system according to claim 1, characterized in that: The spray cooling tower cools the flue gas to -25°C - 5°C.

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