Flue gas carbon capture absorbent pregnant solution regeneration system and method

Abstract

The invention relates to the technical field of carbon dioxide capture, and discloses a flue gas carbon capture absorbent pregnant solution regeneration system and method.The regeneration system comprises a regeneration tower, and a regeneration gas outlet in the top of the regeneration tower is sequentially connected with a cooling assembly and a regeneration gas separator; a liquid outlet of the regeneration gas separator is connected with a first fluid inlet of the cooling assembly, and a first fluid outlet of the cooling assembly is connected with a tower kettle of the regeneration tower. After an absorption solvent rich solution rich in CO2 is regenerated by the regeneration tower, regeneration gas and an absorption solvent barren solution are obtained; cO2 gas can be obtained by cooling and separating moisture in the regeneration gas and is fed into a subsequent process, and the separated moisture exchanges heat with the regeneration gas and is heated, and then enters a regeneration tower from the bottom to perform enhanced gas stripping on an absorption solvent rich solution in the regeneration tower, so that the regeneration energy consumption required by the absorption solvent rich solution is reduced.

Description

Technical Field

[0001] The present invention relates to the technical field of carbon dioxide capture, and in particular to a flue gas carbon capture absorbent rich liquid regeneration system and method. Background Art

[0002] Flue gas produced by the combustion of fossil resources is currently CO 2 The main emission sources account for the total CO 2 Therefore, the development of low-cost flue gas carbon dioxide capture technology has become a research hotspot in the CCUS field.

[0003] According to CO 2 Different separation principles, CO 2 Capture technologies can be divided into four types: absorption, adsorption, membrane separation and cryogenic distillation. 2 The partial pressure of flue gas carbon capture is generally low, and chemical absorption is the most widely used technology in the field of flue gas carbon capture. In the process of flue gas carbon capture by chemical absorption, regeneration energy consumption is the main source of carbon capture costs. Therefore, how to reduce the regeneration energy consumption of flue gas carbon capture absorbent has become an urgent problem to be solved in this field.

[0004] Although some existing patent applications have proposed various processes for waste heat recovery for regeneration and energy saving in the absorption flue gas carbon capture process, the recovered heat usually needs to be used indirectly, and the regeneration process cannot be effectively enhanced. The heat required for the regeneration process is only provided by the reboiler at the bottom of the regeneration tower, which results in low energy utilization in the regeneration process and mediocre energy saving effect. Summary of the invention

[0005] The purpose of the present invention is to overcome the problem of large energy loss in the carbon dioxide capture process in the prior art, and to provide a flue gas carbon capture absorbent rich liquid regeneration system and method. The system can effectively recover the heat of the regeneration gas to enhance the gas lift process, reduce the energy consumption in the flue gas carbon capture process regeneration process, reduce the steam consumption cost in the flue gas carbon dioxide capture process, and improve the economic efficiency of the carbon capture technology.

[0006] In order to achieve the above-mentioned objectives, the first aspect of the present invention provides a flue gas carbon capture absorbent rich liquid regeneration system, wherein the regeneration system includes a regeneration tower, and the regeneration gas outlet at the top of the regeneration tower is connected to a cooling component and a regeneration gas separator in sequence, the liquid outlet of the regeneration gas separator is connected to the first fluid inlet of the cooling component, and the first fluid outlet of the cooling component is connected to the regeneration tower kettle.

[0007] The second aspect of the present invention provides a flue gas carbon capture absorbent rich liquid regeneration method, wherein the CO rich 2The absorption solvent rich liquid is regenerated to obtain regeneration gas and absorption solvent lean liquid, wherein the regeneration gas is cooled and gas-liquid separated to obtain product gas and separation water, and then the separation water is returned to the regeneration gas for heat exchange and temperature increase, and then is used as the gas stripping gas in the regeneration process, and is sent to the absorption solvent rich liquid for regeneration and recycling.

[0008] Through the above technical solution, CO 2 The rich liquid of the absorption solvent is regenerated in the regeneration tower to obtain the regeneration gas and the lean liquid of the absorption solvent. After cooling and separating the water in the regeneration gas, CO can be obtained. 2 The gas is sent to the subsequent process, and the separated water is heated by heat exchange with the regeneration gas and then enters the regeneration tower from the bottom to enhance the gas lift of the absorption solvent rich liquid in the regeneration tower to reduce the regeneration energy consumption required for the absorption solvent rich liquid. BRIEF DESCRIPTION OF THE DRAWINGS

[0009] Figure 1 It is a flow chart of Example 1 of the present invention.

[0010] Description of Reference Numerals

[0011] 1-pretreatment tower; 2-absorption tower; 3-regeneration tower; 4-pretreatment pump; 5-pretreatment cooler; 6-reboiler; 7-wash pump demister; 8-lean and rich liquid heat exchanger; 9-lean liquid pump; 10-lean liquid cooler; 11-wash water cooler; 12-rich liquid pump; 13-fan; 14-regeneration gas compressor; 15-first regeneration gas cooler; 16-second regeneration gas cooler; 17-regeneration gas separator; 101-raw flue gas; 102-purified gas; 103-product CO 2 gas. DETAILED DESCRIPTION

[0012] The endpoints and any values ​​of the ranges disclosed in this article are not limited to the precise ranges or values, and these ranges or values ​​should be understood to include values ​​close to these ranges or values. For numerical ranges, the endpoint values ​​of each range, the endpoint values ​​of each range and the individual point values, and the individual point values ​​can be combined with each other to obtain one or more new numerical ranges, which should be considered as specifically disclosed in this article.

[0013] The first aspect of the present invention provides a flue gas carbon capture absorbent rich liquid regeneration system, wherein the regeneration system includes a regeneration tower, and the regeneration gas outlet at the top of the regeneration tower is connected to a cooling component and a regeneration gas separator in sequence, the liquid outlet of the regeneration gas separator is connected to the first fluid inlet of the cooling component, and the first fluid outlet of the cooling component is connected to the regeneration tower kettle.

[0014] In some embodiments of the present invention, preferably, the cooling assembly comprises a first regeneration gas cooler, the first regeneration gas cooler having the first fluid inlet and the first fluid outlet, and further having a second fluid inlet and a second fluid outlet;

[0015] The regeneration gas outlet at the top of the regeneration tower is connected to the second fluid inlet of the first regeneration gas cooler, and the second fluid outlet of the first regeneration gas cooler is connected to the regeneration gas separator. The first stage of cooling uses separation water to exchange heat with the regeneration gas, so that the heat carried by the regeneration gas is recovered, which is conducive to reducing the regeneration energy consumption.

[0016] In some embodiments of the present invention, preferably, the cooling assembly further comprises a second regenerative gas cooler disposed between the first regenerative gas cooler and the regenerative gas separator, the second fluid outlet of the first regenerative gas cooler is first connected to the second regenerative gas cooler, and the second regenerative gas cooler is then connected to the regenerative gas separator;

[0017] The temperature of the liquid separated by the regeneration gas separator after passing through the first regeneration gas cooler and the second regeneration gas cooler is 100-140°C. The temperature of the liquid entering the regeneration tower affects the regeneration of the absorption solvent. If the temperature is too low, the water cannot be vaporized and the heat carried is insufficient. If the temperature is too high, the solvent will deteriorate. The temperature of the separated liquid after heat exchange can be any value within the numerical range of any two of 100°C, 110°C, 120°C, 130°C, and 140°C.

[0018] In other embodiments of the present invention, preferably, the temperature of the liquid separated by the regeneration gas separator after passing through the first regeneration gas cooler and the second regeneration gas cooler is 100-120° C. Specifically, it can be any value within the numerical range of any two of 100° C., 105° C., 110° C., 115° C., and 120° C.

[0019] In some embodiments of the present invention, preferably, a regeneration gas compressor is provided between the regeneration tower and the cooling assembly, the regeneration gas outlet at the top of the regeneration tower is connected to the regeneration gas compressor, and the regeneration gas compressor is further connected to the second fluid inlet of the first regeneration gas cooler. The regeneration gas is compressed and pressurized by the compressor, which is beneficial to increase its temperature, so as to prepare for heat exchange with the separation water to convert the separation water into water vapor.

[0020] In some embodiments of the present invention, preferably, the pressure of the gas flowing out of the regeneration gas compressor is 30-500kPaG. Increasing the pressure of the regeneration gas is equivalent to increasing the pressure of the liquid carried therein. The separation water requires a certain pressure to be vaporized and enter the tower kettle. The regeneration gas temperature is generally 90-100°C. The temperature of the regeneration gas can be increased by increasing the pressure to ensure that the subsequent heat exchange can turn the refluxed separation water into steam. The pressure of the compressed regeneration gas can be any value within the numerical range of any two of 30kPaG, 100kPaG, 200kPaG, 300kPaG, 400kPaG, and 500kPaG.

[0021] In other embodiments of the present invention, preferably, the pressure of the gas flowing out of the regeneration gas compressor is 150-250 kPaG, and can be any value within the numerical range of any two of 150 kPaG, 180 kPaG, 200 kPaG, 230 kPaG, and 250 kPaG.

[0022] In some embodiments of the present invention, preferably, the system further comprises a reboiler, the liquid inlet of the reboiler is connected to the kettle of the regeneration tower, and the gas outlet of the reboiler is connected to the lower part of the regeneration tower;

[0023] The regeneration tower discharges gas through the regeneration gas outlet, and supplies gas through the reboiler and the first fluid outlet of the cooling component, so that the operating pressure of the regeneration tower is 10-100 kPaG, preferably 20-80 kPaG. The pressure of the regeneration tower is related to the temperature. The higher the pressure, the higher the regeneration temperature, the smaller the driving force of gas phase mass transfer, and the more favorable the regeneration. The operating pressure of the regeneration tower can be any value within the numerical range composed of any two of 10 kPaG, 20 kPaG, 30 kPaG, 40 kPaG, 50 kPaG, 60 kPaG, 70 kPaG, 80 kPaG, 90 kPaG, and 100 kPaG.

[0024] In some embodiments of the present invention, preferably, the cooling assembly further includes a second regenerative gas cooler, which is located between the first regenerative gas cooler and the regenerative gas separator, and the second fluid outlet of the first regenerative gas cooler is connected to the second regenerative gas cooler, and the regenerative gas is cooled again by the second regenerative gas cooler and enters the regenerative gas separator for gas-liquid separation. The second regenerative gas cooler is cooled by circulating water, and the temperature of the regenerative gas can be reduced to about 40°C after two-stage cooling, which meets subsequent requirements.

[0025] The second aspect of the present invention provides a flue gas carbon capture absorbent rich liquid regeneration method, wherein the CO rich 2The absorption solvent rich liquid is regenerated to obtain regeneration gas and absorption solvent lean liquid, wherein the regeneration gas is cooled and gas-liquid separated to obtain product gas and separation water, and then the separation water is returned to the regeneration gas for heat exchange and temperature increase, and then is used as the gas stripping gas in the regeneration process, and is sent to the absorption solvent rich liquid for regeneration and recycling.

[0026] In some embodiments of the present invention, preferably, the regeneration method further comprises compressing the regenerated gas before cooling and gas-liquid separation, and the pressure of the compressed regenerated gas is 30-500 kPaG, preferably 150-250 kPaG.

[0027] In some embodiments of the present invention, preferably, the operating pressure during regeneration of the absorption solvent rich solution is 10-100 kPaG, preferably 20-80 kPaG.

[0028] In some embodiments of the present invention, preferably, the temperature of the separated water after being heated by heat exchange with the regeneration gas is 100-140°C, preferably 100-120°C.

[0029] In some embodiments of the present invention, preferably, the method further comprises pre-treating the raw flue gas to obtain the flue gas to be absorbed, wherein the flue gas to be absorbed is contacted with the lean solution of the absorption solvent to make the CO in the flue gas 2 Transfer to the absorption solvent to obtain the CO-rich 2 The system provided by the present invention can process various types of raw flue gas, such as power plant flue gas, chemical plant flue gas, and steel plant flue gas. 2 The content is 5-25Vol%.

[0030] Combination Figure 1 The system working process provided by the present invention is as follows:

[0031] The raw flue gas 101 is pretreated by the pretreatment tower 1 and enters the absorption zone of the scrubbing tower 2 to obtain a CO-rich 2 The remaining flue gas further ascends through the gas lift cap and enters the washing area of ​​the washing tower 2. The purified gas 102 after washing is discharged from the top of the washing tower 2, while the CO rich flue gas 102 is discharged from the top of the washing tower 2. 2 The absorption solvent rich liquid is drawn out from the tower bottom by the rich liquid pump 12, and after heat exchange with the lean and rich liquid heat exchanger 8, enters the regeneration tower 3 for regeneration. The regeneration gas obtained at the top of the regeneration tower 3 first passes through the compressor 14 to increase the pressure and temperature, and then passes through the first regeneration gas cooler 15 and the second regeneration gas cooler 16 of the cooling component to cool, and further passes through the regeneration gas separator 17 to separate the moisture in the regeneration gas, and then the product CO is obtained. 2The gas 103 is sent to the subsequent process, and the separated water stream passes through the first regeneration gas cooler 15 and the first regeneration gas cooler 16 of the cooling component for heat exchange, and then enters the regeneration tower 3 from the bottom to enhance the gas stripping of the absorption solvent rich liquid in the regeneration tower to reduce the regeneration energy consumption required for the carbon capture rich liquid. The regeneration tower 3 is heated by the reboiler 6 to regenerate the absorption solvent rich liquid in the regeneration tower 3, and the absorption solvent lean liquid in the bottom of the regeneration tower 3 is sent to the lean liquid cooler 10 for cooling by the lean liquid pump 9 after heat exchange by the lean-rich liquid heat exchanger 8, and returned to the absorption area of ​​the washing tower 2 for recycling.

[0032] This system has the following advantages:

[0033] (1) The flue gas carbon capture absorption solvent rich solution is regenerated by enhanced gas stripping, thereby reducing the regeneration energy consumption;

[0034] (2) The gas stripping medium comes from the moisture separated from the regenerated gas and does not affect the existing material balance of the system;

[0035] (3) The heat of the gas stripping medium is recovered from the regeneration gas heat, which improves the energy utilization efficiency of the regeneration process;

[0036] (4) By pressurizing the regeneration gas, the subsequent CO 2 The energy required for compression;

[0037] (5) Under the premise that other conditions are the same, compared with not recycling the heat in the separated water into the stripping medium, under the premise that the reboiler energy supply remains unchanged, the system and method provided by the present invention can achieve a capture rate of carbon dioxide in the raw flue gas of up to 100%.

[0038] The present invention will be described in detail below through examples, wherein the absorption solvent is an organic amine solvent from Sinopec Nanjing Chemical Research Institute Co., Ltd., and the product brand is complex amine MA.

[0039] Example 1

[0040] exist Figure 1 is carried out in the process shown.

[0041] (1)CO 2 The raw flue gas 101 with a content of 12 Vol% is first removed from impurities and cooled in the pretreatment tower 1 before entering the absorption tower 2. In the absorption zone of the absorption tower 2, it contacts with the lean absorption solvent to make the CO in the raw gas 2 Transfer to the absorption solvent to obtain CO-rich 2 The absorption solvent-rich liquid is extracted from the bottom of the pretreatment tower 1 by the pretreatment pump, cooled by the pretreatment cooler 5, and then re-entered the pretreatment tower 1 for recycling;

[0042] (2) Rich in CO2 The absorption solvent rich liquid is drawn out from the kettle of absorption tower 2, heated by the lean-rich liquid heat exchanger 8, and then sent to the regeneration tower 3. The operating pressure of the regeneration tower 3 is 30kPaG. Through the action of gas stripping and heating, the CO in the rich liquid is 2 regeneration;

[0043] The remaining flue gas continues to ascend in the absorption tower 2 and enters the washing area, where it contacts the washing liquid to obtain the purified gas 102 and is discharged from the top of the absorption tower 2. The washing liquid is pumped out of the washing area by the washing pump 7, cooled by the washing water cooler 11, and then enters the upper part of the washing area for recycling.

[0044] (3) The reboiler 6 supplies heat to the regeneration tower 3 to absorb the CO in the solvent rich liquid. 2 Regeneration to obtain regenerated gas and absorption solvent lean liquid, wherein the absorption solvent lean liquid is heat exchanged with the lean-rich liquid heat exchanger 8 and then sent to the absorption area of ​​the absorption tower 2 through the lean liquid pump 9 and the lean liquid cooler 10 for recycling;

[0045] The regenerated gas enters the regenerated gas compressor 14, and the pressure is increased to 100KPaG. Then it enters the first regenerated gas cooler 15 and the second regenerated gas cooler 16 of the cooling assembly in turn. After being cooled to 40°C, it enters the regenerated gas separator 17 to obtain separated water and product gas. The separated water enters the first regenerated gas cooler 15 for heat exchange to 108°C and becomes water vapor. It enters the regeneration tower 3 from the bottom of the regeneration tower 3 to perform enhanced gas stripping on the absorption solvent rich liquid in the regeneration tower 3.

[0046] According to calculation, the regeneration energy consumption using the method of this embodiment is reduced by 13% compared with that of comparative example 1.

[0047] Example 2

[0048] The method of Example 1 is followed, except that the operating pressure of the regeneration tower, the pressure of the compressed regeneration gas, and the temperature of the water vapor obtained after heat exchange with the first regeneration gas cooler 15 are different, as shown in Table 1.

[0049] According to calculation, the regeneration energy consumption using the method of this embodiment is reduced by 18% compared with that of comparative example 1.

[0050] Example 3

[0051] The method of Example 1 is followed, except that the operating pressure of the regeneration tower, the pressure of the compressed regeneration gas, and the temperature of the water vapor obtained after heat exchange with the first regeneration gas cooler 15 are different, as shown in Table 1.

[0052] According to calculation, the regeneration energy consumption using the method of this embodiment is reduced by 19% compared with that of comparative example 1.

[0053] Example 4

[0054] The method of Example 1 is followed, except that the operating pressure of the regeneration tower, the pressure of the compressed regeneration gas, and the temperature of the water vapor obtained after heat exchange with the first regeneration gas cooler 15 are different, as shown in Table 1.

[0055] According to calculation, the regeneration energy consumption using the method of this embodiment is reduced by 15% compared with that of comparative example 1.

[0056] Example 5

[0057] The method of Example 1 is followed, except that the operating pressure of the regeneration tower, the pressure of the compressed regeneration gas, and the temperature of the water vapor obtained after heat exchange with the first regeneration gas cooler 15 are different, as shown in Table 1.

[0058] According to calculation, the regeneration energy consumption using the method of this embodiment is reduced by 17% compared with that of comparative example 1.

[0059] Example 6

[0060] The method of Example 1 is followed, except that the operating pressure of the regeneration tower, the pressure of the compressed regeneration gas, and the temperature of the water vapor obtained after heat exchange with the first regeneration gas cooler 15 are different, as shown in Table 1.

[0061] According to calculation, the regeneration energy consumption using the method of this embodiment is reduced by 13% compared with that of comparative example 1.

[0062] Example 7

[0063] The method of Example 1 is followed, except that the operating pressure of the regeneration tower, the pressure of the compressed regeneration gas, and the temperature of the water vapor obtained after heat exchange with the first regeneration gas cooler 15 are different, as shown in Table 1.

[0064] According to calculation, the regeneration energy consumption using the method of this embodiment is reduced by 14% compared with that of comparative example 1.

[0065] Example 8

[0066] The method of Example 1 is followed, except that the operating pressure of the regeneration tower, the pressure of the compressed regeneration gas, and the temperature of the water vapor obtained after heat exchange with the first regeneration gas cooler 15 are different, as shown in Table 1.

[0067] According to calculation, the regeneration energy consumption using the method of this embodiment is reduced by 11% compared with that of comparative example 1.

[0068] Comparative Example 1

[0069] (1)CO 2 The raw flue gas with a content of 12 Vol% is first removed from impurities and cooled in the pretreatment tower 1 before entering the absorption tower 2. In the absorption zone of the absorption tower 2, it contacts with the lean absorption solvent to make the CO in the raw gas 2 Transfer to the absorption solvent to obtain CO-rich 2The absorption solvent-rich liquid is extracted from the bottom of the pretreatment tower 1 by the pretreatment pump, cooled by the pretreatment cooler 5, and then re-entered the pretreatment tower 1 for recycling;

[0070] (2) Rich in CO 2 The absorbed solvent rich liquid is drawn out from the kettle of absorption tower 2, heated by the lean-rich liquid heat exchanger 8, and then sent to the regeneration tower 3. The operating pressure of the regeneration tower 3 is 30kPaG. Through the action of gas stripping and heating, the CO in the rich liquid is 2 regeneration;

[0071] The remaining flue gas continues to ascend in the absorption tower 2 and enters the washing area, where it contacts the washing liquid to obtain the purified gas 102 and is discharged from the top of the absorption tower 2. The washing liquid is pumped out of the washing area by the washing pump 7, cooled by the washing water cooler 11, and then enters the upper part of the washing area for recycling.

[0072] (3) The reboiler 6 supplies heat to the regeneration tower 3 to absorb the CO in the solvent rich liquid. 2 Regeneration to obtain regenerated gas and absorption solvent lean liquid, wherein the absorption solvent lean liquid is heat exchanged with the lean-rich liquid heat exchanger 8 and then sent to the absorption area of ​​the absorption tower 2 through the lean liquid pump 9 and the lean liquid cooler 10 for recycling;

[0073] The regenerated gas is cooled to 40°C by circulating water and the liquid is separated to obtain high-concentration CO 2 The gas is sent to the subsequent process, and the separated water is directly returned to the regeneration tower 3.

[0074] Table 1 Process parameters of each embodiment

[0075]

[0076] It can be seen from the results in Table 1 that, compared with Comparative Example 1 in which water is directly recycled but not only used for heat recovery, the embodiment of the present invention has a significantly better effect of reducing energy consumption.

[0077] In addition, it has been found that under the premise of keeping the energy supply of the reboiler unchanged, compared with comparative example 1 in which the heat in the separated water is not recycled into the stripping medium in the regeneration tower 3, when the present invention is adopted, the carbon dioxide capture rate in the raw flue gas can be effectively improved, and the maximum capture rate can be close to 100%.

[0078] The preferred embodiments of the present invention are described in detail above, but the present invention is not limited thereto. Within the technical concept of the present invention, the technical solution of the present invention can be subjected to a variety of simple modifications, including the combination of various technical features in any other suitable manner, and these simple modifications and combinations should also be regarded as the contents disclosed by the present invention and belong to the protection scope of the present invention.

Claims

1. A flue gas carbon capture absorbent rich liquid regeneration system, characterized in that: The regeneration system includes a regeneration tower, a regeneration gas outlet at the top of the regeneration tower is connected to a cooling component and a regeneration gas separator in sequence, the liquid outlet of the regeneration gas separator is connected to the first fluid inlet of the cooling component, and the first fluid outlet of the cooling component is connected to the regeneration tower kettle.

2. The flue gas carbon capture absorbent rich liquid regeneration system according to claim 1, characterized in that: The cooling assembly includes a first regeneration gas cooler having the first fluid inlet and the first fluid outlet, and also having a second fluid inlet and a second fluid outlet; The regeneration gas outlet at the top of the regeneration tower is connected to the second fluid inlet of the first regeneration gas cooler, and the second fluid outlet of the first regeneration gas cooler is connected to the regeneration gas separator.

3. The flue gas carbon capture absorbent rich liquid regeneration system according to claim 2, characterized in that: The cooling assembly further comprises a second regenerative gas cooler disposed between the first regenerative gas cooler and the regenerative gas separator; wherein the second fluid outlet of the first regenerative gas cooler is first connected to the second regenerative gas cooler, and the second regenerative gas cooler is then connected to the regenerative gas separator; The temperature of the liquid separated by the regeneration gas separator after flowing through the first regeneration gas cooler and the second regeneration gas cooler is 100-140°C, preferably 100-120°C.

4. The flue gas carbon capture absorbent rich liquid regeneration system according to claim 2 or 3, characterized in that: A regeneration gas compressor is provided between the regeneration tower and the cooling assembly, the regeneration gas outlet at the top of the regeneration tower is connected to the regeneration gas compressor, and the regeneration gas compressor is further connected to the second fluid inlet of the first regeneration gas cooler.

5. The flue gas carbon capture absorbent rich liquid regeneration system according to claim 4, characterized in that: The pressure of the gas flowing out from the regeneration gas compressor is 30-500 kPaG, preferably 150-250 kPaG.

6. The flue gas carbon capture absorbent rich liquid regeneration system according to any one of claims 1 to 5, characterized in that: The system further comprises a reboiler, the liquid inlet of the reboiler is connected to the kettle of the regeneration tower, and the gas outlet of the reboiler is connected to the lower part of the regeneration tower; The regeneration tower discharges gas through the regeneration gas outlet and supplies gas through the reboiler and the first fluid outlet of the cooling component, so that the operating pressure of the regeneration tower is 10-100 kPaG, preferably 20-80 kPaG.

7. A flue gas carbon capture absorbent rich liquid regeneration method, characterized in that: The CO2-rich absorption solvent rich liquid is regenerated to obtain regenerated gas and absorption solvent lean liquid, wherein the regenerated gas is cooled and gas-liquid separated to obtain product gas and separation water, and then the separation water is returned to the regenerated gas for heat exchange and temperature rise to serve as the gas stripping gas in the regeneration process.

8. The flue gas carbon capture absorbent rich liquid regeneration method according to claim 7, characterized in that: The regeneration method further comprises compressing the regeneration gas before cooling and gas-liquid separation, wherein the pressure of the compressed regeneration gas is 30-500 kPaG, preferably 150-250 kPaG; Preferably, the regeneration operation pressure is 10-100 kPaG, preferably 20-80 kPaG.

9. The flue gas carbon capture absorbent rich liquid regeneration method according to claim 7 or 8, characterized in that: The temperature of the separated water after being heated by heat exchange with the regeneration gas is 100-140°C, preferably 100-120°C.

10. The flue gas carbon capture absorbent rich liquid regeneration method according to claim 8 or 9, characterized in that: The method also includes pre-treating the raw flue gas to obtain flue gas to be absorbed, contacting the flue gas to be absorbed with a lean absorption solvent solution to transfer CO2 in the flue gas to the absorption solvent to obtain the CO2-rich absorption solvent rich solution.

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