Efficient absorbent loss reduction device in whole flue gas carbon capture process and flexible regulation and control method of efficient absorbent loss reduction device

Abstract

The invention discloses an efficient absorbent loss reduction device and a flexible regulation and control method in the whole flue gas carbon capture process, and provides an efficient absorbent loss reduction and flexible regulation and control method and system in the whole flue gas carbon capture process from the two aspects of ammonia absorbent escape inhibition and absorbent efficient recovery after desorption while efficient carbon capture is guaranteed. By adopting multiple means of optimizing an absorbent formula, arranging an anti-scaling spiral centrifugal machine behind a CO2 absorption tower to carry out rich liquid phase separation, adopting a novel process flow of taking low-grade alcohol as a stripping carrier of a desorption tower and the like, low loss and high efficiency are taken as optimization targets, high-efficiency capture of CO2 is ensured, and meanwhile, the yield of CO2 is improved. The loss of the absorbent, the CO2 desorption energy consumption and the effective recovery of the escaped absorbent are greatly reduced, and a foundation is laid for the popularization of a CO2 capture technology.

Description

Technical Field

[0001] The present invention belongs to the technical field of air pollution control and carbon emission reduction, and specifically relates to a flue gas carbon capture whole-process absorbent high-efficiency loss reduction device and a flexible control method. Background Art

[0002] Carbon dioxide capture, storage and utilization (CCUS) is a technology to achieve efficient carbon emission reduction in energy systems, among which carbon capture technology is the key to achieving CCUS. At present, chemical absorption method is relatively mature in carbon capture technology and has been industrialized. Among them, amine solution is a commonly used absorbent in chemical absorption method, but it usually has the characteristics of high regeneration energy requirements. Ammonia water, as a substitute for amine, has the characteristics of high absorption capacity and low absorbent regeneration energy requirements.

[0003] When using ammonia water as the absorbent, due to its strong volatility, it is more likely to escape in a high-temperature desorption environment, reducing the ammonia concentration and causing a decline in the performance of the capture process. In addition, the evaporated ammonia in the desorption tower may react with the CO2 in the gas phase to form ammonium salt crystals, which can cause pipe and valve blockages, leading to increased pressure and ultimately the capture system stopping operation. Summary of the invention

[0004] In view of the problems existing in the prior art, the object of the present invention is to provide a device for reducing absorbent loss in the whole process of flue gas carbon capture and a flexible control method.

[0005] The specific technical solutions are as follows:

[0006] A flue gas carbon capture whole process absorbent high-efficiency loss reduction device, comprising a CO2 absorption tower, an anti-scaling spiral centrifuge, a lean-rich liquid heat exchanger, a CO2 desorption tower, an alcohol-containing liquid storage tank, a compressor, a reboiler, a second heat exchanger, a gas-liquid separator, a liquid storage tank, a circulation pump and a first heat exchanger, the bottom pipeline of the CO2 absorption tower is connected to the anti-scaling spiral centrifuge, the outlet pipeline of the anti-scaling spiral centrifuge is divided into two pipelines, one pipeline is sequentially connected to the alcohol-containing liquid storage tank, the compressor, the reboiler and the bottom of the CO2 desorption tower, and the other pipeline is sequentially connected to the lean-rich liquid heat exchanger and the CO2 desorption The spray section of the tower, the side pipeline at the bottom of the CO2 desorption tower is connected to the lean-rich liquid heat exchanger and the first heat exchanger in sequence, the second heat exchanger is connected to the spray section of the CO2 absorption tower, the top discharge port of the CO2 desorption tower is connected to the second heat exchanger and the gas-liquid separator in sequence, the bottom outlet pipeline of the gas-liquid separator is connected to the liquid storage tank, the bottom of the CO2 desorption tower washing section is connected to the bottom of the liquid storage tank, the bottom outlet pipeline of the liquid storage tank is connected to the circulation pump and the top of the CO2 desorption tower washing section in sequence, the side pipeline of the liquid storage tank is connected to the first heat exchanger, and the internal sections of the CO2 desorption tower are separated by gas lifting caps.

[0007] Furthermore, the CO2 absorption tower is composed of an absorption tower packing layer, an absorption tower spray section and an absorption tower demister from bottom to top, and the CO2 desorption tower is composed of a bottom gas lift cap, a desorption tower packing layer, a desorption tower nozzle, a washing section gas lift cap, a washing section nozzle and a desorption tower demister from bottom to top.

[0008] A method for reducing absorbent loss in the whole process of flue gas carbon capture by the above-mentioned device, including suppression of ammonia absorbent escape during CO2 absorption and desorption processes and efficient recovery of ammonia absorbent after desorption;

[0009] The ammonia absorbent is a mixed solution of ammonia, alkanol and water, which inhibits ammonia escape through the interaction between ammonia and alcohol molecules; the ammonia absorbent captures CO2 in the CO2 absorption tower to form a rich liquid, i.e., an ammonium bicarbonate product, and the CO2-rich ammonia solution and alcohol are separated through an anti-scaling spiral centrifuge. The ammonia solution enters the CO2 desorption tower as a rich liquid, and the alcohol solution enters the bottom of the CO2 desorption tower as a stripping agent after passing through a reboiler. Each section inside the CO2 desorption tower is separated by a gas cap, and the ammonia solution does not enter the reboiler, thereby achieving the escape inhibition of the ammonia absorbent; a water washing device is arranged in the CO2 desorption tower, and a part of the ammonia absorbent entrained by CO2 is recovered by utilizing the high solubility of ammonia and alcohol in water. A gas-liquid separation device is arranged at the outlet of the CO2 desorption tower to recover the moisture of the CO2 gas flow to adjust the water balance of the system, thereby achieving efficient recovery of the ammonia absorbent after desorption.

[0010] Furthermore, the ammonia absorbent comprises, by weight, 3-10 wt.% ammonia, 30-50 wt.% alkanol and 40-60 wt.% water, wherein the alkanol comprises one or more of methanol, ethanol, propanol, isopropanol and propylene glycol.

[0011] A method for reducing absorbent loss in the whole process of flue gas carbon capture, specifically comprising the following steps:

[0012] 1) Flue gas enters the CO2 absorption tower, passes through the absorption tower packing layer and the absorption tower spray section in sequence, and the spray inlet temperature is controlled by the first heat exchanger. The ammonia absorbent enters the CO2 absorption tower through spraying, and fully contacts with the flue gas in the absorption tower packing layer to undergo absorption reaction. The rich liquid after the reaction enters the anti-scaling spiral centrifuge, and the rich liquid is separated into ammonia solution rich in CO2 and alcohol solution. The ammonia solution is transported to the lean-rich liquid heat exchanger for heat exchange and then enters the CO2 desorption tower, and the alcohol solution is transported to the alcohol storage tank;

[0013] 2) After the ammonia solution enters the CO2 desorption tower, it passes through the desorption tower nozzle and the desorption tower packing layer and falls into the bottom gas lift cap. The absorption liquid exits the CO2 desorption tower and enters the lean-rich liquid heat exchanger for cooling;

[0014] 3) The alcohol solution enters the reboiler through the compressor for reboiling, and enters the CO2 desorption tower as a stripping carrier, reducing the CO2 partial pressure in the CO2 desorption tower and lowering the desorption temperature to below 80°C;

[0015] 4) The desorbed CO2 enters the water washing section through the washing section gas cap for washing. The washing process removes part of the gaseous ammonia, gaseous alcohol and aerosol produced by part of the desorption process. The washed gas leaves the CO2 desorption tower and passes through the corresponding second heat exchanger and gas-liquid separator to become highly concentrated CO2 gas and reflux solvent. The CO2 gas is used to prepare the alcohol solution.

[0016] 5) The reflux solvent and the washing slurry are injected into the liquid storage tank together, and the absorbent in the liquid storage tank is pumped into the water washing section of the CO2 desorption tower for recycling through a circulating pump; when the liquid level in the liquid storage tank reaches a certain height, the absorbent is transported to the first heat exchanger to mix with the lean liquid for absorption in the CO2 absorption tower.

[0017] A flexible control method for a flue gas carbon capture whole process absorbent high efficiency loss reduction device comprises the following steps:

[0018] S1: Based on online monitoring and offline data, a database covering multi-equipment and multi-scale flue gas parameters, absorption liquid, recovery liquid and stripping steam parameters is established. The parameters include flue gas flow rate G, pH value of each part i , temperature T i , circulation volume L i ;

[0019] S2: Based on the database established in S1, establish an optimization model for efficient absorption and efficient recovery control of absorbents under different working conditions, optimize the proportional-differential-integral controller, regulate the system water balance and absorbent component balance, support the system optimization operation of the absorbent recovery system and the CO2 absorption system, and set each optimization model as follows: Taking CO2 removal efficiency as the control target, based on the established flue gas flow G prediction parameter, establish an optimization control model for the pH value pH1 of the CO2 absorption tower and the circulation volume L1;

[0020] Taking desorption energy consumption as the control target, based on the established absorption tower control model, the desorption partial alcohol steam stripping temperature T is established. j , circulation volume L j Optimization control model, where j = 2, 3;

[0021] S3: Establish a key parameter control model, determine the amount of escaped ammonia through the pH value and circulation volume of the water wash liquid in the desorption tower, and determine the amount of supplementary ammonia alcohol liquid and the amount of lean liquid added from the liquid storage tank through the pH value of the outlet lean liquid of the CO2 desorption tower;

[0022] S4: Compare the real-time data with the database analysis. According to the comparison results, use the best control amount as the input of the proportional-differential-integral controller to timely adjust the pH value of each part and each module to achieve automatic control of the absorbent circulation amount and the amount of stripping alcohol used. Repeat steps S2 and S3 to continuously detect the energy consumption to ensure the actual ammonia absorbent escape suppression and efficient recovery of the absorbent after desorption. The energy saved is consistent with the predicted value, and the steady-state operation with the best comprehensive energy efficiency cost is achieved.

[0023]

[0024] g(ΔL2, T2)=f(E de·set , E de , L3, T3) (2)

[0025]

[0026] Where η CO2·set is the preset CO2 removal rate, η CO2 is the actual CO2 removal rate, E de·set is the preset desorption energy consumption, E de is the actual desorption energy consumption, g(△L2,T2) is expressed as E de is the control target, L3 and T3 are the constraints, and we get △L2,T2,η NH3·escape is the amount of escaped ammonia, L NH3·add To supplement the amount of ammonia liquid, L alcohoLadd To supplement the amount of alcohol liquid, L10-12 is the amount of lean liquid added to the liquid storage tank (10), where 1, 2, 3, 4, 5, and 6 are the parameters of the lean liquid inlet of the CO2 absorption tower, the reboiler outlet, the rich liquid inlet of the CO2 desorption tower, the washing section inlet, the washing section outlet, and the liquid storage tank, respectively.

[0027] The beneficial effects of the present invention are:

[0028] 1) The present invention uses a mixed solution of ammonia, alkanol and water as an absorbent, and the alcohol molecules as hydrogen donors are combined with ammonia molecules as hydrogen acceptors through hydrogen bonds, which effectively reduces the concentration of free ammonia in the liquid phase, thereby reducing the amount of ammonia escape in the absorption liquid;

[0029] 2) The present invention arranges an anti-fouling spiral centrifuge after the CO2 absorption tower, and HCO3 produced by the reaction of ammonia and CO2 - and CO3 2- The product increases the ionic strength of the aqueous solution, making ammonium carbonate / ammonium bicarbonate insoluble in the alcohol solution, causing the organic solvent to be squeezed out of the aqueous phase and form an organic phase due to intermolecular forces, achieving separation of the rich liquid and the alcohol, and increasing the concentration of ammonium bicarbonate in the solution in disguised form, which can greatly reduce the sensible heat of excess water heating in desorption regeneration and the latent heat of vaporization required for partial evaporation;

[0030] 3) In the present invention, the alcohol solution enters the alcohol storage tank, enters the reboiler at the bottom of the CO2 desorption tower through a compressor, and enters the CO2 desorption tower as a stripping carrier, thereby reducing the CO2 partial pressure in the desorption tower and improving the desorption rate. The desorption temperature can be reduced to below 80°C, reducing the evaporation and escape of ammonia and water, reducing the desorption energy consumption, reducing the reabsorption of CO2 by recovering ammonia in the conventional water washing process, and increasing the CO2 production. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 The flowchart of the high-efficiency loss reduction method of the absorbent of the present invention is as follows;

[0032] Figure 2 This is a process flow chart of absorption, desorption and stripping of the present invention;

[0033] Figure 3 It is a control schematic diagram of efficient utilization and flexible regulation of the absorbent of the present invention;

[0034] Figure 4 This is a diagram showing the effect of absorbent escape control and efficient recovery in Example 1 of the present invention.

[0035] In the figure: 1. CO2 absorption tower; 2. Anti-scaling spiral centrifuge; 3. Lean-rich liquid heat exchanger; 4. CO2 desorption tower; 5. Alcohol-containing liquid storage tank; 6. Compressor; 7. Reboiler; 8. Second heat exchanger; 9. Gas-liquid separator; 10. Liquid storage tank; 11. Circulation pump; 12. First heat exchanger; 13. Absorption tower packing layer; 14. Absorption tower spray section; 15. Absorption tower demister; 16. Bottom air lifting cap; 17. Desorption tower packing layer; 18. Desorption tower nozzle; 19. Washing section air lifting cap; 20. Washing section nozzle; 21. Desorption tower demister. DETAILED DESCRIPTION

[0036] The invention is further described below in conjunction with specific embodiments and drawings, but the protection scope of the invention is not limited thereto. A person skilled in the art can and should know that any simple change or replacement based on the essential spirit of the invention should fall within the protection scope required by the invention.

[0037] like Figure 1As shown, a method for reducing the loss of an absorbent in the whole process of flue gas carbon capture is provided, which includes two processes: suppressing the escape of an ammonia absorbent in the CO2 absorption and desorption process and efficiently recovering the ammonia absorbent after desorption. A low-loss and non-volatile ammonia absorbent is used. The absorbent is a mixed solution of ammonia, alkanol and water. The ammonia absorbent includes 3-10wt.% ammonia, 30-50wt.% alkanol and 40-60wt.% water by weight. The alkanol includes one or more of methanol, ethanol, propanol, isopropanol and propylene glycol. The process of the high-efficiency loss reduction method is that the ammonia absorbent captures CO2 in a CO2 absorption tower (1) to form a rich liquid, and then the two phases of the absorbent are separated. The ammonia solution rich in CO2 enters the CO2 desorption tower 4 as a rich liquid, and the alcohol solution also enters the CO2 desorption tower 4 as a stripping component. A gas-liquid separation device is set at the outlet of the CO2 desorption tower 4 to recover the moisture of the CO2 gas flow to adjust the water balance of the system. The recovered absorbent and lean liquid enter the CO2 absorption tower 1 for reuse.

[0038] like Figure 2 As shown, the device used in the method for efficiently reducing the loss of absorbent in the whole process of flue gas carbon capture includes a CO2 absorption tower 1, an anti-scaling spiral centrifuge 2, a lean-rich liquid heat exchanger 3, a CO2 desorption tower 4, an alcohol-containing liquid storage tank 5, a compressor 6, a reboiler 7, a second heat exchanger 8, a gas-liquid separator 9, a liquid storage tank 10, a circulation pump 11 and a first heat exchanger 12. The bottom pipeline of the CO2 absorption tower 1 is connected to the anti-scaling spiral centrifuge 2, and the outlet pipeline of the anti-scaling spiral centrifuge 2 is divided into two pipelines, one pipeline is connected to the alcohol-containing liquid storage tank 5, the compressor 6, the reboiler 7 and the bottom of the CO2 desorption tower 4 in sequence, and the other pipeline is connected to the lean-rich liquid heat exchanger 3 and the spray section of the CO2 desorption tower 4 in sequence. The side pipeline at the bottom of the CO2 desorption tower 4 is connected to the lean-rich liquid heat exchanger 3 and the first heat exchanger 12 in sequence, and the second heat exchanger 12 is connected to the CO2 The spray section of the absorption tower 1 is connected, the top discharge port of the CO2 desorption tower 4 is connected to the second heat exchanger 8 and the gas-liquid separator 9 in sequence, the bottom outlet pipeline of the gas-liquid separator 9 is connected to the liquid storage tank 10, the bottom of the washing section of the CO2 desorption tower 4 is connected to the bottom of the liquid storage tank 10, the bottom outlet pipeline of the liquid storage tank 10 is connected to the circulation pump 11 and the top of the washing section of the CO2 desorption tower 4 in sequence, the side pipeline of the liquid storage tank 10 is connected to the first heat exchanger 12, and the internal sections of the CO2 desorption tower 4 are separated by gas lifting caps. The CO2 absorption tower 1 is composed of an absorption tower packing layer 13, an absorption tower spray section 14 and an absorption tower demister 15 from bottom to top, and the CO2 desorption tower 4 is composed of a bottom gas lifting cap 16, a desorption tower packing layer 17, a desorption tower nozzle 18, a washing section gas lifting cap 19, a washing section nozzle 20 and a desorption tower demister 21 from bottom to top.

[0039] The specific operating steps of the high-efficiency loss reduction method of the whole process absorbent of flue gas carbon capture based on the device are as follows:

[0040] 1) Flue gas enters the CO2 absorption tower 1, passes through the absorption tower packing layer 13 and the absorption tower spray section 14 in sequence, and the spray inlet temperature is controlled by the first heat exchanger 12. The ammonia absorbent enters the CO2 absorption tower 1 through spraying, and fully contacts with the flue gas in the absorption tower packing layer 13 to undergo absorption reaction. The rich liquid after the reaction enters the anti-scaling spiral centrifuge 2, and the rich liquid is divided into an ammonia solution rich in CO2 and an alcohol solution. The ammonia solution is transported to the lean-rich liquid heat exchanger 3 for heat exchange and then enters the CO2 desorption tower 4, and the alcohol solution is transported to the alcohol-containing liquid storage tank 5;

[0041] 2) After the ammonia solution enters the CO2 desorption tower 4, it passes through the desorption tower nozzle 18 and the desorption tower packing layer 17 and falls into the bottom gas lift cap 16. The absorption liquid exits the CO2 desorption tower 4 and enters the lean-rich liquid heat exchanger 3 for cooling;

[0042] 3) The alcohol solution enters the reboiler 7 through the compressor 6 for reboiling, and enters the CO2 desorption tower 4 as a stripping carrier, thereby reducing the CO2 partial pressure in the CO2 desorption tower 4 and lowering the desorption temperature to below 80°C;

[0043] 4) The desorbed CO2 enters the water washing section through the washing section gas lift cap 19 for washing. The washing process removes part of the gaseous ammonia, gaseous alcohol and aerosol produced by part of the desorption process. The washed gas leaves the CO2 desorption tower 4 and passes through the corresponding second heat exchanger 8 and gas-liquid separator 9 to become highly concentrated CO2 gas and reflux solvent. The CO2 gas is used to prepare an alcohol solution.

[0044] 5) The reflux solvent and the washing slurry are injected into the liquid storage tank 10 together, and the absorbent in the liquid storage tank 10 is pumped into the water washing section of the CO2 desorption tower 4 for recycling through the circulation pump 11; when the liquid level in the liquid storage tank 10 reaches a certain height, the absorbent is transported to the first heat exchanger 12 to mix with the lean liquid and used for absorption in the CO2 absorption tower 1.

[0045] like Figure 3 As shown, a flexible control method for a flue gas carbon capture whole process absorbent high efficiency loss reduction device comprises the following steps:

[0046] S1: Based on online monitoring and offline data, a database covering multi-equipment and multi-scale flue gas parameters, absorption liquid, recovery liquid and stripping steam parameters is established. The parameters include flue gas flow rate G, pH value of each part i , temperature T i , circulation volume L i ;

[0047] S2: Based on the database established in S1, establish an optimization model for efficient absorption and efficient recovery control of absorbents under different working conditions, optimize the proportional-differential-integral controller, regulate the system water balance and absorbent component balance, support the system optimization operation of the absorbent recovery system and the CO2 absorption system, and set each optimization model as follows:

[0048] Taking CO2 removal efficiency as the control target, based on the established flue gas flow G prediction parameters, an optimization control model of pH value pH1 and circulation volume L1 of CO2 absorption tower 1 is established;

[0049] Taking desorption energy consumption as the control target, based on the established absorption tower control model, the desorption partial alcohol steam stripping temperature T is established. j , circulation volume L j Optimization control model, where j = 2, 3;

[0050] S3: Establish a key parameter control model, determine the amount of escaped ammonia through the pH value and circulation volume of the water washing liquid of the desorption tower, and determine the amount of supplementary ammonia alcohol liquid and the amount of lean liquid added from the liquid storage tank (10) through the pH value of the outlet lean liquid of the CO2 desorption tower 4;

[0051] S4: Compare the real-time data with the database analysis. According to the comparison results, use the best control amount as the input of the proportional-differential-integral controller to timely adjust the pH value of each part and each module to achieve automatic control of the absorbent circulation amount and the amount of stripping alcohol used. Repeat steps S2 and S3 to continuously detect the energy consumption to ensure the actual ammonia absorbent escape suppression and efficient recovery of the absorbent after desorption. The energy saved is consistent with the predicted value, and the steady-state operation with the best comprehensive energy efficiency cost is achieved.

[0052]

[0053] g(ΔL2, T2)=f(E de·set , E de , L3, T3) (2)

[0054]

[0055]

[0056] Where η CO2·set is the preset CO2 removal rate, η CO2 is the actual CO2 removal rate, E de·set is the preset desorption energy consumption, E de is the actual desorption energy consumption, g(△L2,T2) is expressed as E de is the control target, L3 and T3 are the constraints, and we get △L2,T2,η NH3·escape is the amount of escaped ammonia, L NH3·add To supplement the amount of ammonia liquid, L alcohoLadd To supplement the alcohol volume, L 10-12The amount of lean liquid added to the liquid storage tank (10), wherein 1, 2, 3, 4, 5, 6 are the parameters of the lean liquid inlet of the CO2 absorption tower 1, the outlet of the reboiler 7, the rich liquid inlet of the CO2 desorption tower 4, the inlet of the washing section, the outlet of the washing section and the liquid storage tank 10 respectively.

[0057] Example 1

[0058] Reference Figure 4 In this embodiment, the ammonia absorbent includes 5wt.% ammonia, 40wt.% alkanol and 55wt.% water. After the flue gas is treated by the above system, ammonia escape is reduced and water washing recovery is achieved, with a total emission reduction of 93.2%. The desorption energy consumption is 1.8-2.2GJ / t CO2, which is reduced by 48%.

[0059] Under the premise of ensuring efficient capture of CO2, the present invention proposes a method for efficient loss reduction and flexible regulation of CO2 absorbent from two perspectives: suppressing absorbent escape and efficiently capturing and recovering escaped absorbent, and establishes a complete set of absorption and control systems. In the face of practical problems such as large absorbent loss and serious secondary pollution of carbon capture, multiple means such as optimizing absorbent formula, two-phase absorbent separation, and alcohol steam stripping are adopted to seek the optimization goal with low loss and high efficiency. While efficiently capturing CO2, it reduces absorbent loss, suppresses secondary pollution, effectively reduces desorption energy consumption, and realizes the promotion of clean and long-term CO2 capture technology.

[0060] 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 whole process absorbent high efficiency loss reduction device, characterized in that: The invention comprises a CO2 absorption tower (1), an anti-scaling spiral centrifuge (2), a lean-rich liquid heat exchanger (3), a CO2 desorption tower (4), an alcohol-containing liquid storage tank (5), a compressor (6), a reboiler (7), a second heat exchanger (8), a gas-liquid separator (9), a liquid storage tank (10), a circulation pump (11) and a first heat exchanger (12). The bottom pipeline of the CO2 absorption tower (1) is connected to the anti-scaling spiral centrifuge (2). The outlet pipeline of the anti-scaling spiral centrifuge (2) is divided into two pipelines. One pipeline is connected to the alcohol-containing liquid storage tank (5), the compressor (6), the reboiler (7) and the bottom of the CO2 desorption tower (4) in sequence. The other pipeline is connected to the lean-rich liquid heat exchanger (3) and the spray section of the CO2 desorption tower (4) in sequence. The side pipeline at the bottom of the desorption tower (4) is connected to the lean-rich liquid heat exchanger (3) and the first heat exchanger (12) in sequence, the second heat exchanger (12) is connected to the spray section of the CO2 absorption tower (1), the top discharge port of the CO2 desorption tower (4) is connected to the second heat exchanger (8) and the gas-liquid separator (9) in sequence, the bottom outlet pipeline of the gas-liquid separator (9) is connected to the liquid storage tank (10), the bottom of the washing section of the CO2 desorption tower (4) is connected to the bottom of the liquid storage tank (10), the bottom outlet pipeline of the liquid storage tank (10) is connected to the circulation pump (11) and the top of the washing section of the CO2 desorption tower (4), the side pipeline of the liquid storage tank (10) is connected to the first heat exchanger (12), and each section inside the CO2 desorption tower (4) is separated by a gas lift cap.

2. A flue gas carbon capture whole process absorbent high efficiency loss reduction device as claimed in claim 1, characterized in that: The CO2 absorption tower (1) comprises, from bottom to top, an absorption tower packing layer (13), an absorption tower spray section (14) and an absorption tower demister (15), and the CO2 desorption tower (4) comprises, from bottom to top, a bottom gas lift cap (16), a desorption tower packing layer (17), a desorption tower nozzle (18), a washing section gas lift cap (19), a washing section nozzle (20) and a desorption tower demister (21).

3. A method for reducing absorbent loss in the whole process of flue gas carbon capture using the device as claimed in claim 2, characterized in that: Including CO2 absorption, ammonia absorbent escape suppression during desorption process and efficient recovery of ammonia absorbent after desorption; The ammonia absorbent is a mixed solution of ammonia, alkanol and water, which inhibits ammonia escape through the interaction force between ammonia and alcohol molecules; the ammonia absorbent captures CO2 in a CO2 absorption tower (1) to form a rich liquid, i.e., an ammonium bicarbonate product, and the CO2-rich ammonia solution and alcohol are separated through an anti-scaling spiral centrifuge (2). The ammonia solution enters a CO2 desorption tower (4) as a rich liquid, and the alcohol solution enters the bottom of the CO2 desorption tower (4) as a stripping agent after passing through a reboiler (7). Each section inside the CO2 desorption tower (4) is separated by a gas cap, and the ammonia solution does not enter the reboiler (7), thereby achieving the escape inhibition of the ammonia absorbent; A water washing device is arranged in the CO2 desorption tower (4) to utilize the high solubility of ammonia and alcohol in water to recover part of the ammonia absorbent entrained by the CO2. A gas-liquid separation device is arranged at the outlet of the CO2 desorption tower (4) to recover the moisture of the CO2 gas flow to adjust the water balance of the system, thereby realizing efficient recovery of the ammonia absorbent after desorption.

4. A method for reducing the loss of an absorbent in the whole process of flue gas carbon capture according to claim 3, characterized in that: In terms of mass fraction, the ammonia absorbent comprises 3-10 wt.% ammonia, 30-50 wt.% alkanol and 40-60 wt.% water, wherein the alkanol comprises one or more of methanol, ethanol, propanol, isopropanol and propylene glycol.

5. A method for reducing the loss of an absorbent in the whole process of flue gas carbon capture according to claim 3, characterized in that: The specific steps include: 1) Flue gas enters a CO2 absorption tower (1), passes through an absorption tower packing layer (13) and an absorption tower spray section (14) in sequence, and the spray inlet temperature is controlled by a first heat exchanger (12). Ammonia absorbent enters the CO2 absorption tower (1) through spraying, and fully contacts with flue gas in the absorption tower packing layer (13) to undergo an absorption reaction. The rich liquid after the reaction enters an anti-scaling spiral centrifuge (2), and the rich liquid is separated into an ammonia solution rich in CO2 and an alcohol solution. The ammonia solution is transported to a lean-rich liquid heat exchanger (3) for heat exchange and then enters a CO2 desorption tower (4), and the alcohol solution is transported to an alcohol-containing liquid storage tank (5); 2) After the ammonia solution enters the CO2 desorption tower (4), it passes through the desorption tower nozzle (18) and the desorption tower packing layer (17) and falls into the bottom gas lift cap (16). The absorption liquid exits the CO2 desorption tower (4) and enters the lean-rich liquid heat exchanger (3) for cooling; 3) The alcohol solution enters the reboiler (7) through the compressor (6) for reboiling, and enters the CO2 desorption tower (4) as a stripping carrier, thereby reducing the CO2 partial pressure in the CO2 desorption tower (4) and lowering the desorption temperature to below 80°C; 4) The desorbed CO2 enters the water washing section for washing through the washing section gas lift cap (19). The washing process removes part of the gaseous ammonia and gaseous alcohol produced in the desorption process and part of the aerosol produced by condensation. The washed gas leaves the CO2 desorption tower (4) and passes through the corresponding second heat exchanger (8) and the gas-liquid separator (9) to become highly concentrated CO2 gas and reflux solvent. The CO2 gas is used to prepare an alcohol solution. 5) The reflux solvent and the washing slurry are injected into the liquid storage tank (10) together, and the absorbent in the liquid storage tank (10) is pumped into the water washing section of the CO2 desorption tower (4) for recycling through the circulation pump (11); when the liquid level in the liquid storage tank (10) reaches a certain height, the absorbent is transported to the first heat exchanger (12) to mix with the lean liquid and used for absorption in the CO2 absorption tower (1).

6. A flexible control method for the flue gas carbon capture whole process absorbent high efficiency loss reduction device as claimed in claim 2, characterized in that: The steps include: S1: Based on online monitoring and offline data, a database covering multi-equipment and multi-scale flue gas parameters, absorption liquid, recovery liquid and stripping steam parameters is established. The parameters include flue gas flow rate G, pH value of each part i , temperature T i , circulation volume L i ; S2: Based on the database established in S1, establish an optimization model for the efficient absorption and efficient recovery control of the absorbent under different working conditions, optimize the proportional-differential-integral controller, regulate the system water balance and the absorbent component balance, support the system optimization operation of the absorbent recovery system and the CO2 absorption system, and set each optimization model as follows: Taking the CO2 removal efficiency as the control target, based on the established flue gas flow G prediction parameters, establish the optimization control model of the pH value pH1 and the circulation volume L1 of the CO2 absorption tower (1); Taking desorption energy consumption as the control target, based on the established absorption tower control model, the desorption partial alcohol steam stripping temperature T is established. j , circulation volume L j Optimization control model, where j = 2, 3; S3: Establish a key parameter control model, determine the amount of escaped ammonia through the pH value and circulation volume of the water wash liquid of the desorption tower (4), and determine the amount of supplementary ammonia alcohol liquid and the amount of lean liquid added from the liquid storage tank (10) through the pH value of the outlet lean liquid of the CO2 desorption tower (4); S4: Compare the real-time data with the database analysis. According to the comparison results, use the best control amount as the input of the proportional-differential-integral controller to timely adjust the pH value of each part and each module to achieve automatic control of the absorbent circulation amount and the amount of stripping alcohol used. Repeat steps S2 and S3 to continuously detect the energy consumption to ensure the actual ammonia absorbent escape suppression and efficient recovery of the absorbent after desorption. The energy saved is consistent with the predicted value, and the steady-state operation with the best comprehensive energy efficiency cost is achieved. <h2 style=";text-align:left;direction:ltr">g(ΔL2,T2)=f(E<h2 style=";text-align:left;direction:ltr"> de.set <h2 style=";text-align:left;direction:ltr"> E<h2 style=";text-align:left;direction:ltr"> de， <h2 style=";text-align:left;direction:ltr"> L3, T3) (2) n H3.escape =f(pH4,pH5,L4) (3) Where η CO2·set is the preset CO2 removal rate, η CO2 is the actual CO2 removal rate, E de·set is the preset desorption energy consumption, E de is the actual desorption energy consumption, g(△L2,T2) is expressed as E de is the control target, L3 and T3 are the constraints, and we get △L2,T2,η NH3·escape is the amount of escaped ammonia, L NH3·add To supplement the amount of ammonia liquid, L alcohoLadd To supplement the amount of alcohol liquid, L10-12 is the amount of lean liquid added to the liquid storage tank (10), wherein 1, 2, 3, 4, 5, and 6 are the parameters of the lean liquid inlet of the CO2 absorption tower (1), the outlet of the reboiler (7), the rich liquid inlet of the CO2 desorption tower (4), the inlet of the washing section, the outlet of the washing section, and the liquid storage tank (10), respectively.

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