Method and system for removing carbon dioxide from a solvent using lower heat

Abstract

The present invention relates to a method and system for removing carbon dioxide (CO2) from a solvent. In particular, the present invention relates to a method and system for removing carbon dioxide (CO2) from a carbon dioxide (CO2)-rich solvent.

Description

[Technical Field]

[0001] The present invention relates to a method and system for removing carbon dioxide (CO2) from a flue gas stream using a solvent-based system. In particular, the present invention relates to a method and system for regenerating a solvent and removing carbon dioxide (CO2) from a carbon dioxide (CO2)-rich solvent stream. [Background technology]

[0002] Flue gases from power plants and other industrial activities contain pollutants such as greenhouse gases. One such greenhouse gas is CO2. Due to growing public concern, CO2 emissions into the atmosphere from industrial activities are increasingly being regulated.

[0003] CO2 capture technologies can be applied to reduce the amount of CO2 released into the atmosphere. By selectively capturing CO2, it can be reused or geographically sequestrated.

[0004] Chinese Published Patent No. 107970743 discloses a carbon dioxide separation method using a two-column multi-stage absorption and desorption method. Chinese Published Patent No. 1079743 also discloses flash regeneration of a semi-lean solvent using low heat. However, the use of low heat disclosed in Chinese Published Patent No. 1079743 is insufficient to achieve the level of liquid solvent regeneration of the present invention presented herein.

[0005] The CO2 recovery method of the present invention is intended for the recovery of CO2 from flue gas and industrial gas emissions, such as from plants that burn hydrocarbon fuels. The CO2 recovery method of the present invention is also applicable to the recovery of CO2 from coal, gas and oil combustion boilers, combined cycle power plants, coal gasification, hydrogen plants, biogas plants and power plant waste.

[0006] Known CO2 capture technologies can be divided into physical adsorbents and chemical adsorbents (generally called carbon capture solvents).

[0007] The CO2 recovery method of the present invention uses a solvent (i.e., a carbon recovery solvent). The solvent removes CO2 from one or more gas streams. The CO2 in the gas streams selectively reacts with components in the solvent, resulting in the removal of CO2 from the gas phase and absorption into the solvent to form a CO2-rich solvent. Next, the CO2-rich solvent is heated, releasing CO2 into the gas phase, depleting the CO2 content of the CO2-rich solvent, and forming a CO2-lean solvent. The CO2-lean solvent is reused in the system to recover additional CO2.

[0008] Figure 1 shows a block diagram 100 of a conventional method and system for recovering CO2 from flue gas.

[0009] Conventional methods and systems for recovering CO2 from flue gases use a solvent (initially a lean CO2 solvent) to separate CO2 from the gas mixture, which selectively reacts with CO2 (forming a CO2-rich solvent). After the CO2 reacts with the solvent (lean CO2 solvent), heat can be used to regenerate the solvent (CO2-rich solvent) (to a lean CO2 solvent) to release the CO2, and the solvent can be regenerated to further process the CO2.

[0010] As shown in Figure 1 (showing the prior art method and system), flue gas 101 containing CO2 enters the system. The temperature of the flue gas 101 when it enters the system is typically 100°C. The flue gas 101 passes through the booster fan 102 as needed. The booster fan 102 increases the pressure of the flue gas 101 to compensate for the pressure drop caused by the system, thereby ensuring that the pressure of the resulting lean CO2 flue gas (flue gas 107) is the same as that of the flue gas 101.

[0011] The flue gas 101 passes through the direct contact cooler 103. In the direct contact cooler, the flue gas 101 comes into contact with the recirculation loop of chilled water 104 in a reverse flow configuration. This contact cools the flue gas 101 to a temperature of typically 40°C, forming flue gas 101a.

[0012] Flue gas 101a enters absorption column 105, where it comes into contact with liquid solvent 106 (cold, CO2 lean solvent) in a backflow manner. Flue gas 101a rises through absorption column 105. Liquid solvent 106 (cold, CO2 lean solvent) enters absorption column 105 via a liquid partition (not shown in Figure 1) located at the top of absorption column 105 and cascades downward through absorption column 105. Absorption column 105 contains packing to maximize the ratio of surface area to volume. Active components in liquid solvent 106 (cold, CO2 lean solvent) react with CO2 in flue gas 101a.

[0013] When the liquid solvent 106 (cold, CO2-lean solvent) reaches the bottom of the absorption column 105, it becomes CO2-rich and forms liquid solvent 108 (cold, CO2-rich solvent).

[0014] When flue gas 101a reaches the top of absorption column 105, the CO2 is depleted, forming flue gas 107 (lean CO2). Flue gas 107 (lean CO2) is released from the top of absorption column 105.

[0015] Liquid solvent 108 (cold, CO2-rich solvent) is regenerated by high heat in regenerator 109 and modified into liquid solvent 106 (cold, CO2-lean solvent). Liquid solvent 108 (cold, CO2-rich solvent) enters regenerator 109 (high heat) via crossover heat exchanger 110. In crossover heat exchanger 110, liquid solvent 108 (cold, CO2-rich solvent) is heated by liquid solvent 111 (warm, CO2-lean solvent) to form liquid solvent 112 (warm, CO2-rich solvent).

[0016] The liquid solvent 112 (warm, CO2-rich solvent) enters the upper part of the regenerator 109 (high heat) and cascades downward through the regenerator 109 (high heat). Inside the regenerator (high heat), the liquid solvent 112 (warm, CO2-rich solvent) is heated by contact with vapor 114 (high heat). Typically, the vapor 114 (high heat) flows upward through the regenerator 109 (high heat) and flows back against the liquid solvent 112 (warm, CO2-rich solvent). Upon heating, the reaction between the active components of the liquid solvent and CO2 reverses, releasing CO2 gas 115 and forming the liquid solvent 111 (warm, CO2-lean solvent).

[0017] Gaseous CO2115 is released from the top of regenerator 109 (high heat). Gaseous CO2115 can be used in downstream processes.

[0018] The liquid solvent 111 (warm, CO2 lean solvent) is supplied to the reboiler 113 (high heat). Inside the reboiler 113 (high heat), the liquid solvent 111 (warm, CO2 lean solvent) boils, and steam 114 (high heat) is formed. The steam 114 (high heat) is used in the regenerator 109 (high heat).

[0019] Liquid solvent 111 (warm, CO2-lean solvent) enters the crossover heat exchanger 110 and is cooled by contact with liquid solvent 108 (cold, CO2-rich solvent) to form liquid solvent 106 (cold, CO2-lean solvent). The newly formed liquid solvent 10 6 (cold CO2 lean solvent) is ready to repeat the absorption process again.

[0020] The liquid solvent 106 (cold, CO2 lean solvent) can pass through an additional condenser (not shown) before entering the absorption column 105.

[0021] In typical CO2 capture methods using chemical absorbents, a significant amount of energy is required to regenerate the absorbent. Therefore, the regeneration of chemical absorbents is one of the biggest operating costs for CO2 capture.

[0022] After the absorbent becomes a CO₂-rich chemical absorbent, there is a need for a low-cost method of regenerating the absorbent (i.e., the liquid solvent). Summary of the Invention

[0023] The ability to generate heat in the quantity and quality required for regenerating chemical absorbents is important. Generally, the higher the temperature of the generated heat, the higher the value of the heat. In a typical CO₂ capture process, the heat required to heat the CO₂-rich chemical absorbent (i.e., the CO₂-rich liquid solvent) is supplied in the form of a heating fluid such as condensed steam, high-temperature gas, hot water, or hot oil.

[0024] In a typical CO₂ capture process using a chemical absorbent, regeneration of the chemical absorbent requires a temperature of 120°C or higher (high-grade heat). To remove CO₂ from the CO₂-rich chemical absorbent, it is desirable to use low-value low-grade heat sources as much as possible, so that the regeneration method is as cost-effective as possible.

[0025] The present invention provides a method and system for removing CO₂ from a solvent (e.g., a method for forming a CO₂-lean chemical absorbent from a CO₂-rich chemical absorbent).

[0026] The present invention provides a method and system for removing CO₂ from a solvent, wherein a low-grade heat source (i.e., low-grade heat) is used to partially or fully regenerate a lean chemical absorbent.

[0027] The present invention provides a method and system for removing CO₂ from a solvent, wherein part of the high-grade heat (120°C or higher) is replaced with low-grade heat of 60°C or higher and lower than 120°C. This reduces the required high-grade heat by 30 to 50%, typically 50% (plus or minus 10%), and reduces the overall operating cost.

[0028] The present invention provides a method and system typically comprising at least two regeneration sections. Typically, one regeneration section comprises a regenerator for lower heat, and a second regeneration section comprises a second regenerator for higher heat. The regenerator (lower heat) generates a high-temperature CO2 semi-lean flow in which CO2 is partially depleted. The second regeneration section (higher heat) generates a high-temperature CO2 lean flow similar to flow 111 in conventional methods and systems for recovering CO2 from flue gas.

[0029] This invention provides a method and system for exchanging heat between liquid flows that are regenerated using both high-temperature and low-temperature technologies. The heat exchange allows for advantageous system customization, thereby enabling favorable optimization of the overall operating cost of energy consumption.

[0030] The following clauses, which may be used individually or in any combination with one or more features disclosed in the text and / or figures of the specification, are representative features of the present invention.

[0031] Herein, the present invention will be described with reference to the following provisions. 1. A method for regenerating a solvent containing carbon dioxide (CO2), wherein the method is: To provide a solvent containing carbon dioxide (CO2), The process involves passing a solvent containing carbon dioxide (CO2) through a low-temperature regenerator to form a lean carbon dioxide (CO2) solvent, This includes passing a carbon dioxide (CO2) lean solvent through a low-temperature reboiler. 2. The method according to Clause 1, wherein the lower heat regenerator operates at temperatures in the range of 60°C to less than 120°C. 3. The lower heat regenerator operates at temperatures in the range of 100-119°C or 100-115°C, as described in Clause 1 or Clause 2. 4. The method described in any one of clauses 1 to 3, wherein the lower heat reboiler operates at a temperature in the range of 60°C to less than 120°C. 5. The method according to any one of the clauses 1 to 4, wherein the low-heat reboiler operates at a temperature in the range of 100 to 119°C or 100 to 115°C. 6. The method is, The process involves passing a solvent containing carbon dioxide (CO2) through a high-level heat regenerator to form a lean carbon dioxide (CO2) solvent, The method according to any one of claims 1 to 5, further comprising passing a carbon dioxide (CO2) lean solvent through a high-temperature reboiler. 7. The method according to Clause 6, wherein the high-temperature regenerator operates at a temperature of 120°C or higher. 8. The method according to Clause 6 or Clause 7, wherein the high-temperature regenerator operates at a temperature of 120°C to 140°C. 9. The method according to any one of the clauses 6 to 8, wherein the high-temperature reboiler operates at a temperature of 120°C or higher. 10. The method according to any one of the clauses 6 to 9, wherein the high-temperature reboiler operates at a temperature of 120°C to 140°C. 11. The method according to any one of Clauses 6 to 10, wherein a low-temperature regenerator, low-temperature reboiler, high-temperature regenerator, and high-temperature reboiler are fluidly connected so that a solvent containing carbon dioxide (CO2) passes between two, three, or four components. 12. The method according to Clause 11, wherein the solvent containing carbon dioxide (CO2) exiting the lower heat reboiler is optionally sent to the higher heat regenerator via a crossover heat exchanger. 13. The lower heat regenerator and the lower heat reboiler are fluidly connected so that a solvent containing carbon dioxide (CO2) passes between the lower heat regenerator and the lower heat reboiler. The high-temperature regenerator and the high-temperature reboiler are fluidly connected so that a solvent containing carbon dioxide (CO2) passes between the high-temperature regenerator and the high-temperature reboiler. The lower heat regenerator and lower heat reboiler are hydrodynamically independent (not in fluid communication) and thermally dependent (thermally in communication) with the higher heat regenerator and higher heat reboiler, as described in any one of Clauses 6 to 10. 14. A method described in any one of the clauses 1 to 13, the method being: Dividing a solvent containing carbon dioxide (CO2) into a first flow and a second flow, The first flow is passed through the low heat regenerator and the low heat reboiler, A method comprising passing a second flow through a high-temperature regenerator and a high-temperature reboiler. 15. The method described in Clause 14, wherein the first flow is hydrodynamically dependent (fluid communication) and thermally dependent (thermally connected) on the second flow. 16. The method according to Clause 14, wherein the first flow is hydrodynamically independent (fluidally in communication) and thermally dependent (thermally in communication) with the second flow. 17. The method according to Clause 14, wherein the first flow is hydrodynamically independent (not in fluid communication) and thermally independent (not in thermal communication) of the second flow. 18. The step of dividing a solvent containing carbon dioxide (CO2) into a first flow and a second flow includes dividing the solvent containing carbon dioxide (CO2) (by weight % (or volume %); ratio of first flow to second flow): 50:50 (plus or minus 10%); or, 10%~30%:90%~70%; or, 70%~90%:30%~10%; or, 20%:80% (plus or minus 10%); or, 25%:75% (plus or minus 10%); or, 80%:20% (plus or minus 10%); or, The method described in any one of Clauses 14 to 17, which is 75%:25% (plus or minus 10%). 19. The method according to any one of the clauses 1 to 18, wherein a lower heat regenerator and a higher heat regenerator are combined to form a single lower heat and higher heat composite regenerator. 20. The method according to Clause 19, wherein a lower heat and higher heat combined regenerator, a lower heat reboiler and a higher heat reboiler are in fluid communication such that a solvent containing carbon dioxide (CO2) passes between two or three components. 21. A lower heat and higher heat combined regenerator and a lower heat reboiler are fluidly connected so that a solvent containing carbon dioxide (CO2) passes between the lower heat and higher heat combined regenerator and the lower heat reboiler; and / or, The method according to Clause 19 or Clause 20, wherein a lower heat and higher heat combined regenerator and a higher heat reboiler are in fluid communication such that a solvent containing carbon dioxide (CO2) passes between the lower heat and higher heat combined regenerator and the higher heat reboiler. 22. The method according to any one of the clauses 19 to 21, wherein the lower heat reboiler is located in the middle of a combined lower heat and higher heat regenerator. 23. The method according to any one of Clauses 1 to 22, wherein a gas that does not dissolve or react with the solvent (optionally, an inert gas such as hydrogen or nitrogen) is introduced into the reboiler and / or regenerator to lower the temperature of the reboiler and / or regenerator, thereby allowing the use of lower heat alone or a combination of lower and higher heat. 24. The step of providing a solvent containing carbon dioxide (CO2) may involve using a CO2-rich solvent, optionally 2 to 3.3 mol L. -1 The method according to any one of Clauses 1 to 23, comprising providing a CO2-rich solvent having a carbon dioxide concentration of [value missing]. 25. The formed carbon dioxide (CO2) lean solvent is 0.0 to 0.7 mol L. -1 The method according to any one of the claims 1 to 24, wherein the carbon dioxide (CO2) lean solvent has a carbon dioxide concentration of . 26. The step of providing a solvent containing carbon dioxide (CO2) is: The method according to any one of Clauses 1 to 25, comprising contacting flue gas with a carbon dioxide (CO2) lean solvent in one, two, three, four, five, six, seven, eight, nine, or ten or more absorption columns, wherein the absorption columns are in fluid communication with a lower heat regenerator and a lower heat reboiler. 27. The method according to Clause 26, wherein the absorption column is in fluid communication with a lower heat regenerator and a lower heat reboiler via a crossover heat exchanger. 28. The method according to Clause 26 or Clause 27, wherein the absorption column is in fluid communication with a high-temperature regenerator and a high-temperature reboiler via a crossover heat exchanger. 29. The method according to any one of Clauses 1 to 28, wherein the solvent is a strengthening solvent, which optionally includes a tertiary amine, a sterically hindered amine, a polyamine, a salt, and water, and optionally the solvent is CDRMax. 30. A system for regenerating a solvent containing carbon dioxide (CO2), wherein the system is Low-temperature regenerator and Including a low-temperature reboiler, A system in which a low-temperature regenerator and a low-temperature reboiler are independently configured to regenerate a carbon dioxide (CO2) lean solvent at temperatures in the range of 60°C to less than 120°C (or 100°C to 119°C, or 100°C to 115°C). 31. The system further, High-temperature regenerator and Including a high-temperature reboiler, The high-temperature regenerator and high-temperature reboiler are configured to regenerate a carbon dioxide (CO2) lean solvent at a temperature of 120°C or higher, as described in Clause 30. 32. The system described in Clause 31, wherein the high-temperature regenerator operates at a temperature of 120°C to 140°C. 33. A system as described in Clause 31 or Clause 32, in which the high-temperature reboiler operates at a temperature of 120°C to 140°C. 34. A system according to any one of clauses 30 to 33, which combines a low-temperature regenerator and a high-temperature regenerator to form a single combined low-temperature and high-temperature regenerator. 35. A lower heat regenerator, lower heat reboiler, higher heat regenerator, higher heat reboiler and / or lower heat and higher heat combined regenerator is a system as described in any one of clauses 30 to 34, in which a solvent containing carbon dioxide (CO2) is fluidly connected to pass between two, three, or four components during use. 36. The system described in Clause 35, wherein the solvent containing carbon dioxide (CO2) exiting the lower heat reboiler is optionally sent to the higher heat regenerator via a crossover heat exchanger. 37. The lower heat regenerator and the lower heat reboiler are fluidly connected so that a solvent containing carbon dioxide (CO2) passes between the lower heat regenerator and the lower heat reboiler. The high-temperature regenerator and the high-temperature reboiler are fluidly connected so that a solvent containing carbon dioxide (CO2) passes between the high-temperature regenerator and the high-temperature reboiler. A lower heat regenerator and lower heat reboiler are hydrodynamically independent (not in fluid communication) and thermally dependent (thermally connected) with a higher heat regenerator and a higher heat reboiler, as described in any one of Clauses 30 to 36. 38. A system described in any one of clauses 30 to 37, where the system is A splitter for dividing a solvent containing carbon dioxide (CO2) into a first flow and a second flow, wherein the splitter is The first flow is passed through the low heat regenerator and the low heat reboiler. A system configured to pass a second flow through a high-temperature regenerator and a high-temperature reboiler. 39. A system as described in Clause 38, in which the first flow is hydrodynamically dependent (fluid-connected) and thermally dependent (thermally connected) on the second flow. 40. A system as described in Clause 38, in which the first flow is hydrodynamically independent (not in fluid communication) and thermally dependent (thermally in communication) with the second flow. 41. The system described in Clause 38, in which the first flow is hydrodynamically independent (not in fluid communication) and thermally independent (not in thermal communication) of the second flow. 42. The splitter is configured to divide the solvent containing carbon dioxide (CO2) into a first stream and a second stream in the following ratio (weight % (or volume %); ratio of first stream to second stream): 50:50 (plus or minus 10%); or, 10%~30%:90%~70%; or, 70%~90%:30%~10%; or, 20%:80% (plus or minus 10%); or, 25%:75% (plus or minus 10%); or, 80%:20% (plus or minus 10%); or, A system described in any one of clauses 38 to 41, where the ratio is 75%:25% (plus or minus 10%). 43. A lower heat and higher heat combined regenerator and a lower heat reboiler are fluidly connected so that a solvent containing carbon dioxide (CO2) passes between the lower heat and higher heat combined regenerator and the lower heat reboiler; and / or, The lower heat and higher heat combined regenerator and the higher heat reboiler are in fluid communication so that a solvent containing carbon dioxide (CO2) passes between the lower heat and higher heat combined regenerator and the higher heat reboiler, as described in Clause 34. 44. The system uses a CO2-rich solvent or a CO2-lean solvent, optionally with a carbon dioxide concentration of 2-3.3 mol / L. -1 A CO2-rich solvent of any choice, with a carbon dioxide concentration of 0.0 to 0.7 mol / L. -1 A system as described in any one of clauses 30 to 43, configured to convert carbon dioxide (CO2) into a lean solvent. 45. The system further, A system according to any one of Clauses 30 to 44, comprising 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 absorption columns, the absorption columns being in fluid communication with a lower heat regenerator and a lower heat reboiler. 46. ​​The system according to Clause 45, wherein the absorption column is in fluid communication with a lower heat regenerator and a lower heat reboiler via a crossover heat exchanger. 47. The system according to Clause 45 or Clause 46, wherein the absorption column is in fluid communication with a high-temperature regenerator and a high-temperature reboiler via a crossover heat exchanger. 48. The system described in any one of clauses 45 to 47, wherein the absorption column is in fluid communication with a lower heat and higher heat combined regenerator, a lower heat reboiler and a higher heat reboiler via a crossover heat exchanger. 49. The system further comprises a gas (optionally an inert gas such as hydrogen or nitrogen) that is insoluble in or does not react with the solvent, and the gas is present in the reboiler and / or regenerator to lower the temperature in the reboiler and / or regenerator, thereby allowing the use of lower heat alone or a combination of lower and higher heat, as described in any one of clauses 30 to 48. 50. The system further comprises a strengthening solvent, which optionally comprises a tertiary amine, a sterically hindered amine, a polyamine, a salt, and water; optionally, the solvent is CDRMax, as described in any one of clauses 30 to 49.

[0032] The currently claimed methods and systems are typically applied to carbon recovery processes and methods. However, the present invention is not limited to its specific applications and can be applied to any method requiring the removal of CO2 components from an absorbent. The present invention is not limited to the separation of liquids and gases. [Brief explanation of the drawing]

[0033] [Figure 1] This is a schematic diagram of a conventional system 100 used to recover CO2 from flue gas. [Figure 2] This is a schematic diagram of a system 200 used to recover CO2 from flue gas according to the present invention. [Figure 3] This is a schematic diagram of a system 300 used to recover CO2 from flue gas according to the present invention, in which two flows of liquid solvent are hydrodynamically independent and heat is exchanged between the two flows of liquid solvent. [Figure 4] This is a schematic diagram of a system 400 used to recover CO2 from flue gas according to the present invention, in which the liquid solvent is divided between a lower heat regenerator and a higher heat regenerator. [Figure 5] This is a schematic diagram of a system 500 used to recover CO2 from flue gas according to the present invention, in which two absorption columns and two regenerators are hydraulically and thermally independent. [Figure 6]This is a schematic diagram of a system 600 used to recover CO2 from flue gas according to the present invention, in which a liquid solvent passes through a single regenerator using low and high heat. [Figure 7] This is a schematic diagram of a system 700 used to recover CO2 from flue gas according to the present invention, in which a liquid solvent passes through a single regenerator that uses lower heat from a reboiler located in the middle of the regenerator and higher heat from a reboiler located at the bottom of the regenerator. [Figure 8] This is a schematic diagram of system 800 used to recover CO2 from flue gas according to the present invention, in which the liquid solvent passes through a single regenerator using lower heat and hydrogen. [Figure 9] This graph compares systems 100 and 200. [Figure 10] This graph compares systems 100, 200, and 300. [Figure 11] This graph compares systems 100, 200, 300, and 400. [Figure 12] This graph compares systems 100, 200, 300, 400, and 500. [Figure 13] This graph compares the CO2 removal rates from a gas stream containing 15% by volume of CO2 (on a dry basis, i.e., the presence of water is excluded for the purpose of the calculation) by liquid solvents simulated as a function of heat at 120°C, 105°C, and 90°C. [Figure 14] This graph compares the CO2 removal rates from a gas stream containing 9 vol% CO2 by liquid solvents simulated as a function of heat at 120°C, 105°C, and 90°C (dry basis, i.e., the presence of water is excluded for calculation purposes). [Figure 15] This graph compares the CO2 removal rates from a gas stream containing 5% by volume of CO2 (dry basis, i.e., the presence of water is excluded for the purpose of the calculation) by a liquid solvent simulated as a function of heat at 120°C, 105°C, and 90°C. [Modes for carrying out the invention]

[0034] Embodiments of the present invention will be described below with reference to the accompanying drawings. The accompanying drawings illustrate various embodiments of the system, method, and various other aspects of the present disclosure. Those skilled in the art will understand that the boundaries of elements shown in the drawings (e.g., boxes, groups of boxes, or other shapes) represent examples of boundaries. In some examples, one element may be designed as multiple elements, or multiple elements may be designed as one element. In some examples, an element shown as an internal component of one element may be implemented as an external component of another element, and vice versa. The components in the drawings are not necessarily to a constant scale, and instead the emphasis is on illustrating the principle. Furthermore, elements may not be drawn to a constant scale. The following description will be non-limiting and non-exclusive with reference to the drawings.

[0035] Herein, several embodiments of the present disclosure will be described in detail. The words “include,” “have,” “contain,” and “contain,” and other forms thereof, are intended to be semantically equivalent and freely terminated in that the item(s) following any of these words is not intended to be an exhaustive list of such items(s) or to be limited to only the listed items(s).

[0036] It should also be noted that the singular forms “a,” “an,” and “the” used herein and in the appended claims include plural references unless the context explicitly indicates otherwise. Any systems and methods similar to or equivalent to those described herein may be used in the implementation or testing of embodiments of the present disclosure, but preferred systems and methods are described herein.

[0037] Embodiments of this disclosure are described in full below with reference to the accompanying drawings, where similar figures throughout the drawings represent similar elements and exemplary embodiments are shown. However, embodiments of the claims can be embodied in many different forms and should not be construed as being limited to the embodiments described herein. The examples described herein are non-limiting examples and are merely examples of other possible examples.

[0038] definition Some of the terms used to describe this invention are listed below: Flue gas is gas discharged into the atmosphere through pipes or channels that function as exhaust from boilers, furnaces, or similar environments. For example, flue gas can be emissions from power plants and other industrial activities that burn hydrocarbon fuels, such as coal, gas, and oil-fired power plants, combined cycle power plants, coal gasification, hydrogen plants, biogas plants, and power plant waste.

[0039] "Liquid solvent" refers to the absorbent. The liquid solvent may also be a strengthening solvent. Optionally, the strengthening solvent includes a tertiary amine, a sterically hindered amine, a polyamine, a salt, and water. Optionally, the tertiary amine in the strengthening solvent is one or more N-methyl-diethanolamine (MDEA) or triethanolamine (TEA). Optionally, the sterically hindered amine in the strengthening solvent is one or more 2-amino-2-ethyl-1,3-propanediol (AEPD), 2-amino-2-hydroxymethyl-1,3-propanediol (AHPD), or 2-amino-2-methyl-1-propanol (AMP). Optionally, the polyamine in the strengthening solvent is one or more 2-piperazine-1-ethylamine (AEP) or 1-(2-hydroxyethyl)piperazine. Optionally, the salt in the strengthening solvent is potassium carbonate. Optionally, water (e.g., deionized water) is included in the solvent so that the solvent exhibits a single liquid phase. Optionally, the solvent is CDRMax, sold by Carbon Clean Solutions Limited. CDRMax, sold by Carbon Clean Solutions Limited, has the following formulation: 15-25% by weight of 2-amino-2-methylpropanol (CAS No. 124-68-5), 15-25% by weight of 1-(2-ethylamino)piperazine (CAS No. 140-31-8), 1-3% by weight of 2-methylamino-2-methylpropanol (CAS No. 27646-80-6), 0.1-1% by weight of potassium carbonate (584-529-3), and the remainder being deionized water (CAS No. 7732-18-5).

[0040] A "lean CO2 solvent" refers to a solvent with a relatively low carbon dioxide concentration. In carbon dioxide capture methods, the amount of lean CO2 solvent used for contact with flue gas is typically 0.0 to 0.7 moles per liter. -1 It has a carbon dioxide concentration of [value].

[0041] A "CO2 semilean solvent" refers to a solvent with a relatively moderate carbon dioxide concentration. In the carbon dioxide method, the amount of CO2 semilean solvent used for contact with the flue gas is typically 0.7 mol / L. -1 Ultra-2 moles L -1has a carbon dioxide concentration of less than. When removing CO₂ from flue gas, the CO₂-rich solvent becomes a CO₂ semi-lean solvent when CO₂ exits the liquid solvent upon heating and partially regenerates the lean solvent.

[0042] The term "CO₂ semi-rich solvent" refers to a solvent having a relatively moderate carbon dioxide concentration. In a carbon dioxide capture process, the CO₂ semi-rich solvent for contacting with flue gas is typically 0.7 mol / L -1 to less than 2 mol / L -1 has a carbon dioxide concentration of less than. In the context of removing CO₂ from flue gas, when CO₂ reacts with the active components of the liquid solvent and exits the gas phase, the CO₂-lean liquid solvent becomes CO₂ semi-rich.

[0043] The term "CO₂-rich solvent" refers to a solvent having a relatively high concentration of carbon dioxide. In a carbon dioxide capture process, the CO₂-rich solvent after contacting with flue gas is typically 2 to 3.3 mol / L -1 has a carbon dioxide concentration of.

[0044] The term "direct contact cooler" refers to a part of a system in which CO₂-rich flue gas is cooled. Typically, CO₂-rich flue gas enters the direct contact cooler at a temperature of 100°C and is cooled to a temperature of 40°C by a recirculation loop of cold water.

[0045] The term "absorption column" refers to a part of a system where components of a solvent (CO₂-lean solvent) capture CO₂ from the gas phase into the liquid phase to form a CO₂-rich solvent. The absorption column includes trays or packing (random or structured), which provides close gas-liquid contact with the mass transfer zone. The absorption column may be a static column or a rotating packed bed (RPB). The absorption column typically operates during use at a pressure of, for example, 1 bar to 30 bar.

[0046] A "static column" refers to a component of a system used in separation methods. It is a hollow column equipped with an internal mass transfer device (e.g., tray, structured packing, random packing). The packed bed may be structured or randomly packed, and may contain a catalyst or adsorbent.

[0047] A "Rotary Packed Bed (RPB)" refers to an absorber or regenerator in which the packing material is contained in a rotatable disk (rather than a static bed like a static column), and can be rotated at high speed to generate high-gravity centrifugal force within the RPB.

[0048] A "low-heat regenerator" or "low-heat regenerator" refers to a part of a system that uses heat (usually from hot vapor) to reverse the reaction between a liquid solvent and CO2, producing CO2 and a solvent (lean CO2 solvent). Low-heat regenerators typically operate in temperature ranges of 60°C to less than 120°C, or 100°C to 119°C, or 105°C to 115°C. Liquid solvent regeneration may be partial. Low-heat regenerators can be static columns or rotary packed beds (RPBs). Regenerators typically operate at pressures of, for example, 0.2 bar to 0.8 bar during use.

[0049] A "high-heat regenerator" or "high-heat regenerator" refers to a part of a system that typically uses heat from hot vapor to reverse the reaction between a liquid solvent and CO2, producing CO2 and a solvent (lean CO2 solvent). High-heat regenerators typically operate in the following temperature ranges: above 120°C, or 120–135°C, or 120–140°C. Liquid solvent regeneration may be partial. High-heat regenerators may be static columns or rotary packed beds (RPBs). Regenerators typically operate at pressures of, for example, 0.8 bar to 5 bar during use.

[0050] A "crossover heat exchanger" refers to a part of a system where liquids are thermally connected, so that one liquid solvent is heated while another is cooled. For example, a liquid solvent (a cold, CO2-rich solvent) can be heated by the heat of another liquid solvent (a warm, CO2-lean solvent). Crossover heat exchangers typically operate at pressures of, for example, 1 bar to 30 bar during use.

[0051] "Low" and "low-temperature" typically refer to a part or process of a system or method that operates at temperatures in the range of 60°C to less than 120°C.

[0052] "High" and "high-temperature" refer to a part of a system or process that typically operates at temperatures above 120°C, or in the range of 120°C to 135°C, or 120°C to 140°C.

[0053] "Cold" usually refers to temperatures in the range of 20 to 60°C.

[0054] "Slightly warm" usually refers to temperatures in the range of 60 to 110°C.

[0055] "Warm" usually refers to temperatures above 120°C, typically in the range of 120-180°C or 120-140°C.

[0056] A "reinforced solvent" refers to a solvent that can achieve a high CO2 load (arbitrarily ≥ 3.0 mol L) and forms a higher proportion of bicarbonates than carbamates. An example of a reinforced solvent is found in a U.S. patent application. This is contained in Publication No. 2017 / 0274317, the disclosure of which is incorporated herein by reference.

[0057] In some embodiments, the strengthening solvent includes an alkanolamine, a reactive amine, and a carbonate buffer.

[0058] "L / G" represents the ratio of the solvent flow rate (given on a mass basis) to the flue gas flow rate (given on a mass basis).

[0059] "PSIG" or "psig" refers to gauge pressure (i.e., measured pressure) relative to atmospheric pressure, and is measured in pounds per square inch. Ambient pressure is measured as 0 psig. 1 psig = 6894.76 Pascals.

[0060] "Mole %" refers to the percentage of the total moles of a particular component in a mixture of components.

[0061] "Weight %" refers to the percentage of a particular component by total weight within a mixture of ingredients.

[0062] "Volume %" refers to the percentage of a particular component's total volume within a mixture of components.

[0063] "Specific reboiler load" refers to the reboiler energy required to regenerate a rich or semi-rich solvent flow into a lean or semi-lean solvent (expressed as the weight of 50 psig saturated vapor condensed in liquid) divided by the weight of recovered CO2.

[0064] "Simulation" refers to a method simulated using software called ProMax®, provided by Bryan Research. ProMax® is an industry-standard software used, in particular, for simulating CO2 capture methods and systems. example System 200: System and Method of the Invention

[0065] Figure 2 is a schematic diagram of a system 200 used to recover CO2 from flue gas according to the present invention.

[0066] Flue gas 201 containing CO2 enters system 200 at a temperature of typically 100°C. Optionally, flue gas 201 passes through a booster fan (not shown). The booster fan prevents or compensates for any pressure drops occurring within the system.

[0067] Optionally, the CO2-rich flue gas 201 enters a direct contact cooler (not shown). Optionally, the flue gas 201 enters the direct contact cooler after passing through a booster fan. The flue gas 201 comes into contact with a chilled water recirculation loop in a reverse flow configuration. By coming into contact with the chilled water recirculation loop, the flue gas 201 is cooled to a temperature of typically 40°C.

[0068] Flue gas 201 enters the first absorption column 205a. In the first absorption column 205a, flue gas 201 comes into contact with liquid solvent 206a (cold, semi-lean CO2 solvent) and liquid solvent 208a (cold, semi-rich CO2 solvent). The components in solvents 206a and 208a selectively react with CO2 in flue gas 201, resulting in the transfer of CO2 from the gas phase to the liquid phase.

[0069] The first absorption column 205a includes structural packing that maximizes the surface area-to-volume ratio of components in solvents 206a and 208a. By maximizing the surface area-to-volume ratio, flue gas 2 The reaction between CO2 in 01 and the components in solvents 206a and 208a is promoted.

[0070] Flue gas 201 enters the bottom of the first absorption column 205a and rises through the first absorption column 205a, while solvents 206a and 208a enter the top of the first absorption column 205a, cascade through the first absorption column 205a, and fall to the bottom of the first absorption column 205a by gravity. Flue gas 201 comes into contact with solvents 206a and 208a in a backflow configuration.

[0071] When reacted with CO2 in flue gas 201, solvents 206a and 208a become CO2-rich, forming liquid solvent 208 (cold, CO2-rich solvent).

[0072] Using both solvents 206a and 208a partially depletes the CO2 content of flue gas 201. Flue gas 201a (partially depleted of CO2) is formed. Since solvents 206a and 208a already have a CO2 load when they enter the first absorption column, the amount of CO2 that the solvent can remove is reduced (compared to a CO2-lean solvent).

[0073] After exiting the first absorption column 205a, the flue gas 201a (partially depleted of CO2) enters the second absorption column 205b. In the second absorption column 205b, the flue gas 201a (partially depleted of CO2) comes into contact with the liquid solvent 206 (cold, lean CO2 solvent).

[0074] The second absorption column 205b contains structural packing that maximizes the surface area-to-volume ratio of the active ingredient in the liquid solvent 206 (cold, lean CO2 solvent). By maximizing the surface area-to-volume ratio, the reaction between CO2 in flue gas 201a (partially depleted CO2) and the ingredient in the liquid solvent 206 (cold, lean CO2 solvent) is promoted.

[0075] Flue gas 201a (partially depleted CO2) enters the bottom of the second absorption column 205b and rises through the second absorption column 205b. Meanwhile, liquid solvent 206 (cold, lean CO2 solvent) enters the second absorption column 205b at the top and cascades through the second absorption column 205b. Flue gas 201a (partially depleted CO2) comes into contact with liquid solvent 206 (cold, lean CO2 solvent) in a backflow configuration.

[0076] When reacted with CO2 in flue gas 201a (partially depleted of CO2), liquid solvent 206 (cold, lean CO2 solvent) becomes partially CO2-rich, forming liquid solvent 208a (cold, semi-rich CO2 solvent).

[0077] When flue gas 201a (partially depleted of CO2) reaches the top of the second absorption column 205b, it is lean CO2 (flue gas 207). Flue gas 207 (lean CO2) is released from the top of the second absorption column 205b. Flue gas 207 (lean CO2) typically contains 30% to 90% less CO2 (by weight) than flue gas 201 and typically contains 85% less CO2 (by weight) than flue gas 201.

[0078] The liquid solvent 208 (cold, CO2-rich solvent) formed when solvents 206a and 208a react with CO2 enters the first crossover heat exchanger 210a. Inside the first crossover heat exchanger 210a, the liquid solvent 208 (cold, CO2-rich solvent) is heated using heat from the liquid solvent 211a (slightly warm, CO2 semi-lean solvent). Upon heating, the liquid solvent 208 (cold, CO2-rich solvent) forms the liquid solvent 212a (slightly warm, CO2-rich solvent).

[0079] Liquid solvent 212a (slightly warm, CO2-rich solvent) is partially regenerated in regenerator 209a (low heat). Liquid solvent 212a (slightly warm, CO2-rich solvent) is regenerated in regenerator 2 It enters the upper part of 09a (lower heat) and cascades to the bottom under gravity through the regenerator 209a (lower heat). Inside the regenerator 209a (lower heat), the liquid solvent 212a (slightly warm, CO2-rich solvent) is heated by contact with vapor 214a (lower heat).

[0080] Typically, vapor 214a (lower heat) flows upward through regenerator 209a (lower heat), flowing in the opposite direction to the liquid solvent 212a (slightly warm, CO2-rich solvent). Vapor 214a (lower heat) is usually at a temperature between 60°C and less than 120°C.

[0081] When heated, the reaction between the solvent components and CO2 reverses, partially depleting the CO2 content of the liquid solvent and forming gaseous CO2215.

[0082] Gaseous CO2215 exits from the top of regenerator 209a (lower heat). The gaseous CO2215 can be used downstream.

[0083] The liquid solvent enters the reboiler 213a (lower heat), where it is heated to form liquid solvent 211a (slightly warm, CO2 semilean solvent) and vapor 214a (lower heat).

[0084] The liquid solvent 211a (slightly warm, CO2 semilean solvent) is divided into separate streams. Typically, the liquid solvent 211a (slightly warm, CO2 semilean solvent) is divided into two streams.

[0085] The splitting ratio is determined by (a) the quality of the heat supplied to the regenerator, (b) the difference in values ​​between the lower and higher heat sources, and (c) the required amount of CO2 recovery.

[0086] One stream of liquid solvent 211a (slightly warm, CO2 semilean solvent) enters the first crossover heat exchanger 210a, where liquid solvent 211a heats the incoming liquid solvent 208 (cold, CO2-rich solvent). By heating liquid solvent 208, liquid solvent 211a is cooled, forming liquid solvent 206a (cold, CO2 semilean solvent). Liquid solvent 206a enters the first absorption column 205a.

[0087] The liquid solvent 206a (cold, CO2 semi-lean solvent) can pass through an additional cooler before entering the first absorption column 205a.

[0088] Another flow of liquid solvent 211a (slightly warm, CO2 semilean solvent) enters the second crossover heat exchanger 210b, where liquid solvent 211a (slightly warm, CO2 semilean solvent) is heated (higher heat) by liquid solvent 211 (warm, CO2 lean solvent) produced in regenerator 209. Upon heating, liquid solvent 211a (slightly warm, CO2 semilean solvent) forms liquid solvent 212 (warm, CO2 semilean solvent).

[0089] The liquid solvent 212 (warm, CO2 semilean solvent) enters the upper part of the regenerator 209 (high heat) and cascades through the regenerator 209 (high heat) to the bottom under gravity. Inside the regenerator 209 (high heat), the liquid solvent 212 (warm, CO2 semilean solvent) is heated by contact with the vapor 214 (high heat).

[0090] Typically, vapor 214 (higher heat) flows upward through regenerator 209 (higher heat), in a reverse flow relative to the liquid solvent 212 (warm, CO2 semilean solvent). Vapor 214 (higher heat) is usually at a temperature of 120–135°C.

[0091] When the liquid solvent 212 (warm, CO2 semi-lean solvent) comes into contact with vapor 214 (high heat), CO2 is removed from the solvent more effectively than within the operating temperature range (low heat) of the regenerator 209a. The reaction between the solvent components and CO2 is reversed upon heating, resulting in the production of a liquid solvent with depleted CO2 content and gaseous CO2215.

[0092] Gaseous CO2215 exits from the top of regenerator 209 (high heat). The gaseous CO2215 can be used in downstream applications.

[0093] After exiting the regenerator 209 (high heat), the liquid solvent is heated in the reboiler 213 (high heat). Heating the liquid solvent produces vapor 214 (high heat) and liquid solvent 211 (warm, CO2 lean solvent).

[0094] Steam 214 (high heat) enters regenerator 209 (high heat).

[0095] Liquid solvent 211 (warm, CO2 lean solvent) enters the second crossover heat exchanger 210b. Inside the second crossover heat exchanger 210b, liquid solvent 211 (warm, CO2 lean solvent) is cooled by the incoming liquid solvent 211a (slightly warm, CO2 semi-lean solvent), resulting in the formation of liquid solvent 206 (cold, CO2 lean solvent). Liquid solvent 206 (cold, CO2 lean solvent) is sent to the second absorption column 205b.

[0096] Liquid solvent 206 (cold, CO2 lean solvent) can pass through an additional cooler before entering the second absorption column 205b.

[0097] Compared to conventional CO2 capture methods, the configuration of the present invention (for example, the configuration described with reference to Figure 2) advantageously divides the liquid solvent between at least two regenerators operating at at least two temperatures (one regenerator providing lower heat and the other providing higher heat).

[0098] The configuration of System 200 replaces some of the higher heat (typically in the temperature range of 120°C to 135°C) with lower heat in the temperature range of 60°C to below 120°C.

[0099] The configuration of System 200 reduces the higher heat required to regenerate the liquid solvent by 20–35%, typically 35%, compared to the system in Figure 1 where only the higher heat is used.

[0100] The configuration of System 200 mitigates the decomposition of solvent components by lowering the required temperature. This maximizes the lifespan of the solvent used in the system.

[0101] The configuration of System 200 reduces operating costs by decreasing the load requiring more expensive high-temperature energy.

[0102] System 200 typically removes 30-90% (by weight) of CO2 from flue gas 201, or typically removes 85% (by weight) of CO2 from flue gas 201. Higher or lower removal can be achieved by adjusting the process parameters. System 300: The present invention and a system and method in which two flows of liquid solvent remain hydrodynamically independent.

[0103] Figure 3 is a schematic diagram of a system 300 used to recover CO2 according to an example of the present invention.

[0104] In system 300, the liquid solvents are not mixed and divided. Instead, there are two liquid solvents. It exists as a hydrodynamically independent flow.

[0105] In system 300, flue gas 301 containing CO2 enters the system at a temperature of 100°C. The flue gas 301 passes through a booster fan and a direct contact cooler as needed, where it is cooled to a temperature of 40°C (not shown).

[0106] In system 300, two absorption columns (305a and 305b) are used to remove CO2 from flue gas 301.

[0107] Flue gas 301 enters the bottom of the first absorption column 305a and rises through the first absorption column 305a, while liquid solvent 306a enters the first absorption column 305a at the top and cascades through the first absorption column 305a under gravity. Flue gas 301 comes into contact with liquid solvent 306a (cold, CO2 semilean solvent) in a backflow configuration. Components in liquid solvent 306a selectively react with CO2 gas, causing CO2 to move from the gas phase to the liquid phase.

[0108] When solvent 306a reaches the bottom of the first absorption column 305a, the solvent is CO2-rich, and at this point, it is liquid solvent 308 (cold, CO2-rich solvent).

[0109] The liquid solvent 308 (cold CO2-rich solvent) enters the regenerator 309a (lower heat), where the reaction between CO2 and the liquid solvent is reversed by using vapor 314a (lower heat). Typically, vapor 314a (lower heat) flows upward through the regenerator 309a (lower heat) and flows back against the liquid solvent 308 (cold, CO2-rich solvent). Gaseous CO2 315 is formed and exits from the top of the regenerator 309a (lower heat).

[0110] Next, the liquid solvent 308 (cold, CO2-rich solvent) enters the reboiler 313a (lower heat) where it is heated. Upon heating, vapor 314a (lower heat) and liquid solvent 311a (slightly warm, CO2 semi-lean solvent) are formed. The vapor 314a (lower heat) is typically at a temperature of 60°C to less than 120°C.

[0111] The liquid solvent loses 15-20% (by weight) of its original CO2 content and becomes flow 311a (slightly warm, semi-lean CO2 solvent).

[0112] The liquid solvent 311a (slightly warm, CO2 semilean solvent) enters the first crossover heat exchanger 310a, where heat is transferred from the liquid solvent 311a to the second solvent. The liquid solvent 306a (cold, CO2 semilean solvent) is reformed, allowing the absorption process to resume.

[0113] The liquid solvent 306a (cold, CO2 semi-lean solvent) can pass through an additional cooler before entering the first absorption column 305a.

[0114] When flue gas 301 reaches the top of the first absorption column 305a, its CO2 content is partially depleted, becoming flue gas 301a (partially depleted CO2).

[0115] In the second absorption column 305b, flue gas 301a (partially depleted CO2) comes into contact with the second solvent. The second solvent is in the form of liquid solvent 306 (cold, lean CO2 solvent). Flue gas 301a (partially depleted CO2) enters the bottom of the second absorption column 305b and rises through the second absorption column 305b. Meanwhile, liquid solvent 306 (cold, lean CO2 solvent) enters the second absorption column 305b at the top and cascades through the second absorption column 305b under gravity. Flue gas 301a (partially depleted CO2) comes into contact with liquid solvent 306 (cold, lean CO2 solvent) in a reverse flow configuration. The components in the (cold CO2 lean solvent) selectively react with CO2 gas, resulting in the transfer of CO2 from the gas phase to the liquid phase.

[0116] When the liquid solvent 306 (cold, CO2-lean solvent) reaches the bottom of the second absorption column 305b, liquid solvent 308a (cold, CO2-semi-rich solvent) is formed.

[0117] Liquid solvent 308a (cold, CO2 semi-rich solvent) enters the first crossover heat exchanger 310a, where it is heated by the heat from the first solvent. Liquid solvent 312a (slightly warm, CO2 semi-rich solvent) is formed.

[0118] Liquid solvent 312a (slightly warm, CO2 semi-rich solvent) enters the second crossover heat exchanger 310b, where it is heated by the heat from liquid solvent 311 (warm, CO2 lean solvent) to form liquid solvent 312 (warm, CO2 semi-rich solvent).

[0119] The liquid solvent 312 (warm, CO2 semi-rich solvent) enters the regenerator 309 (higher heat), where the reaction between CO2 and the liquid solvent is reversed by using vapor 314 (higher heat). Typically, vapor 314 (higher heat) flows upward through the regenerator 309 (higher heat) and flows back against the liquid solvent 312 (warm, CO2 semi-rich solvent). Gaseous CO2 315 is formed and exits from the top of the regenerator 309 (higher heat).

[0120] The liquid solvent enters the reboiler 313 (high heat) where it is heated. Upon heating, vapor 314 (high heat) and liquid solvent 311 (warm, CO2 lean solvent) are formed. The vapor 314 (high heat) is typically at a temperature of 120-135°C.

[0121] Liquid solvent 311 (warm, CO2 lean solvent) enters the second crossover heat exchanger 310b and exchanges heat with liquid solvent 312a (slightly warm, CO2 semi-rich solvent) to form liquid solvent 306 (cold, CO2 lean solvent). Liquid solvent 306 (cold, CO2 lean solvent) can then restart the absorption process.

[0122] The liquid solvent 306 (cold, CO2 lean solvent) can pass through an additional condenser (not shown) before entering the second absorption column 305b.

[0123] When flue gas 301a (partially depleted of CO2) reaches the top of the second absorption column 305b, it is lean CO2 (flue gas 307). Flue gas 307 (lean CO2) is released from the top of the second absorption column 305b.

[0124] The CO2 flow (higher heat) generated in regenerator 309 is combined with CO2 (lower heat) from regenerator 309a. Both CO2 flows are mixed and terminate the process as a single flow. The gaseous CO2 315 can be used in the downstream process.

[0125] Compared to typical CO2 capture methods, the configuration of System 300 advantageously divides the liquid solvent between at least two regenerators operating at at least two temperatures.

[0126] The configuration of System 300 replaces the higher heat (typically in the temperature range of 120–135°C) with the lower heat (typically in the temperature range of 60–120°C).

[0127] The configuration of System 300 reduces the required high-temperature energy by 30-60%, typically 60%.

[0128] The configuration of System 300 mitigates the decomposition of solvent components by lowering the required temperature.

[0129] The configuration of System 300 reduces operating costs by decreasing the amount of high heat required.

[0130] The configuration of system 300 is flexible with respect to the shift between a lower heat source and a higher heat source for the regeneration of the liquid solvent.

[0131] System 300 typically removes 30-90% (by weight) of CO2 from flue gas 301, and typically removes 85% (by weight) of CO2 from flue gas 301. Higher and lower removal rates can be achieved by adjusting the process parameters. System 400: The present invention, a system and method wherein a liquid solvent is divided between a lower heat regenerator and a higher heat regenerator.

[0132] Figure 4 is a schematic diagram of a system 400 used to recover CO2 according to the present invention.

[0133] In system 400, the liquid solvent is divided between the lower heat regenerator and the higher heat regenerator (409a and 409).

[0134] In system 400, flue gas 401 containing CO2 enters the system 400 at a temperature typically of 100°C. The flue gas 401 passes through a booster fan and a direct contact cooler as needed, where it is cooled to a temperature typically of 40°C.

[0135] In system 400, two absorption columns (405a and 405b) are used to remove CO2 from flue gas 401.

[0136] Flue gas 401 enters the first absorption column 405a. The first absorption column 405a contains structural packing that facilitates the removal of CO2 from the flue gas. In the first absorption column 405a, the flue gas 401 comes into contact with liquid solvent 406a (cold, semi-lean CO2 solvent) and liquid solvent 408a (cold, semi-rich CO2 solvent). Components in the solvents selectively react with the CO2 gas, causing CO2 to move from the gas phase to the liquid phase.

[0137] Flue gas 401 enters the bottom of the first absorption column 405a and rises through the first absorption column 405a, while liquid solvents 406a and 408a enter the first absorption column 405a at the top and cascade to the bottom of the first absorption column 405a under gravity. Flue gas 401 comes into contact with solvents 406a and 408a in a backflow configuration.

[0138] When the liquid solvent reaches the bottom of the first absorption column 405a, the solvent is CO2-rich and becomes liquid solvent 408 (cold, CO2-rich solvent).

[0139] When flue gas 401 reaches the top of the first absorption column 405a, its CO2 content is partially depleted, and at this point it becomes flue gas 401a (partially depleted CO2).

[0140] In the second absorption column 405b, flue gas 401a (partially depleted of CO2) comes into contact with liquid solvent 406 (cold, lean CO2 solvent). The second absorption column 405b contains structural packing that facilitates the removal of CO2 from the flue gas. The flue gas 401a (partially depleted of CO2) enters the bottom of the second absorption column 405b and rises through the second absorption column 405b. Meanwhile, the liquid solvent 406 (cold, lean CO2 solvent) comes into contact with the second absorption It enters the upper part of column 405b and, under gravity, cascades to the bottom of the second absorption column 405b.

[0141] When the liquid solvent 406 (cold, lean CO2 solvent) reaches the bottom of the second absorption column 405b, it becomes semi-rich in CO2. The liquid solvent then forms liquid solvent 408a (cold, semi-rich CO2 solvent) and enters the first absorption column 405a.

[0142] When flue gas 401a (partially depleted of CO2) reaches the top of the second absorption column 405b, it is lean CO2 (flue gas 407). Flue gas 407 (lean CO2) is released from the top of the second absorption column 405b.

[0143] As it exits the first absorption column 405a, the liquid solvent 408 (cold, CO2-rich solvent) splits into two streams.

[0144] The splitting ratio is determined by (a) the quality of the heat supplied to the regenerator, (b) the difference in values ​​between the lower and higher heat sources, and (c) the required amount of CO2 recovery.

[0145] Typically, liquid solvent 408 (cold, CO2-rich solvent) is split into two flows in a ratio of 20:80 or 25:75 (the ratio is expressed in weight percent or volume percent), forming the first and second flows, respectively.

[0146] The first flow enters the first crossover heat exchanger 410a, where it is heated by the liquid solvent 411a (a slightly warm, CO2 semi-lean solvent) to form the liquid solvent 412a (a slightly warm, CO2-rich solvent).

[0147] The liquid solvent 412a (slightly warm, CO2-rich solvent) enters the regenerator 409a (lower heat) and, while in contact with the vapor 414a (lower heat), cascades over the packed bed to the bottom of the regenerator 409a (lower heat) under gravity. The liquid solvent is partially regenerated, producing gaseous CO2415.

[0148] Gaseous CO2415 exits from the top of regenerator 409a (lower heat). Gaseous CO2415 can be used in downstream processes.

[0149] Upon reaching the bottom of the regenerator 409a (lower heat), the liquid solvent is drawn into the reboiler 413a (lower heat), where it is heated by the lower heat. Heating generates vapor 414a (lower heat) and liquid solvent 411a (slightly warm, CO2 semilean solvent).

[0150] Steam 414a (low heat) is used in regenerator 409a (low heat). Steam 414a (low heat) is typically at a temperature of 60°C to less than 120°C.

[0151] The liquid solvent 411a (slightly warm, CO2 semilean solvent) enters the first crossover heat exchanger 410a, where it is cooled by the incoming liquid solvent 408 (cold, CO2-rich solvent). As a result of the cooling, liquid solvent 406a (cold CO2 semilean solvent) is reformed, allowing the absorption process to restart.

[0152] The liquid solvent 406a (cold, CO2 semi-lean solvent) can pass through an additional cooler before entering the first absorption column 405a.

[0153] The second stream is further divided into two streams.

[0154] The splitting ratio is determined by (a) the quality of the heat supplied to the regenerator (high-grade heat) and (b) the required amount of CO2 recovery.

[0155] Typically, liquid solvent 408 (cold CO2-rich solvent) is divided into two flows in a ratio of 90:10 or 80:20 (expressed as a weight percentage or volume percentage), forming the first and second flows, respectively.

[0156] The first flow of the second flow is heated by the liquid solvent 411 (warm, CO2-lean solvent) in the second crossover heat exchanger 410b to form the liquid solvent 412 (warm, CO2-rich solvent).

[0157] The liquid solvent 412 (warm, CO2-rich solvent) enters the regenerator 409 (high heat) and, while in contact with the vapor 414 (high heat), cascades through the packed bed to the bottom of the regenerator 409 (high heat). The liquid solvent's CO2 content is depleted, and gaseous CO2415a (warm) is formed.

[0158] The second flow is heated by gaseous CO2415a (warm) in the condenser 416.

[0159] After heating the second flow, the gaseous CO2415 exits the system. The gaseous CO2415 can be used downstream.

[0160] Next, the second flow enters the regenerator 409 (high heat) and, while in contact with the vapor 414 (high heat), cascades to the bottom of the regenerator 409 (high heat). The liquid solvent's CO2 content is depleted, and gaseous CO2415a (warm) is formed.

[0161] At the bottom of the regenerator 409 (high heat), the solvent is heated by the reboiler 413 (high heat). Upon heating, vapor 414 (high heat) and liquid solvent 411 (warm, CO2 lean solvent) are produced.

[0162] Steam 414 (high heat) is used in the regenerator (high heat). Steam 414 (high heat) is typically at a temperature of 120-135°C.

[0163] The liquid solvent 411 (warm, CO2-lean solvent) enters the second crossover heat exchanger 410b, where it is cooled by the incoming liquid solvent 408 (cold, CO2-rich solvent). As a result of the cooling, the liquid solvent 406 (cold, CO2-lean solvent) is reformed, allowing the absorption process to restart.

[0164] Liquid solvent 406 (cold, CO2 lean solvent) can pass through an additional cooler before entering the second absorption column 405b.

[0165] Compared to typical CO2 capture methods, the configuration of System 400 advantageously divides the liquid solvent between at least two regenerators operating at at least two temperatures.

[0166] The configuration of System 400 replaces higher heat (typically in the temperature range of 120–135°C) with lower heat (typically in the temperature range of 60–120°C).

[0167] The configuration of System 400 reduces the required high-temperature energy by 20-35%, typically 35%.

[0168] The System 400 configuration reduces the degradation of solvent components by shortening the residence time of the solvent in the regenerator (high heat).

[0169] The configuration of System 400 reduces operating costs by reducing the amount of high-temperature heat required.

[0170] The configuration of system 400 minimizes the proportion of liquid solvent regenerated in regenerator 409a (low heat) and maximizes the proportion of liquid solvent regenerated in regenerator 409 (high heat).

[0171] System 400 typically removes 30-90% (by weight) of CO2 from flue gas 401, and typically removes 85% (by weight) of CO2 from flue gas 401. Higher and lower removal rates can be achieved by adjusting the process parameters. System 500: The system and method of the present invention, in which two absorption columns and two regenerators are hydrodynamically and thermally independent.

[0172] Figure 5 is a schematic diagram of a system 500 used to recover CO2 according to the present invention.

[0173] In system 500, the two absorption columns (505a and 505b), the two heat regenerators (509a and 509), and the two solvent circuits are hydrodynamically and thermally independent of each other.

[0174] The liquid solvent is divided between the lower and higher heat circuits in a 50:50 ratio or a 75:25 ratio (expressed as weight percent or volume percent) between each circuit.

[0175] In the first liquid solvent circuit of system 500, the first absorption column 505a is used for partial removal of CO2 from flue gas 501. The flue gas 501 containing CO2 enters system 500 at a temperature of typically 100°C. The flue gas 501 passes through a booster fan and a direct contact cooler as needed, where it is cooled to a temperature of typically 40°C.

[0176] Flue gas 501 enters the first absorption column 505a. Flue gas 501 comes into contact with liquid solvent 506a (cold, CO2 semi-lean solvent) in the first absorption column 505a to form liquid solvent 508 (cold, CO2-rich solvent).

[0177] Liquid solvent 508 (cold, CO2-rich solvent) enters the first crossover heat exchanger 510a, where it is heated by the heat from liquid solvent 511a (slightly warm, CO2 semi-lean solvent). Liquid solvent 512a (slightly warm, CO2-rich solvent) is formed.

[0178] The liquid solvent 512a (slightly warm, CO2-rich solvent) enters the regenerator 509a (lower heat), and the reaction between CO2 and the liquid solvent is reversed by using vapor 514a (lower heat), forming a liquid solvent in which CO2 and gaseous CO2515 are partially depleted.

[0179] Gaseous CO2515 exits from the top of regenerator 509a (lower heat). Gaseous CO2515 can be used in downstream processes.

[0180] Next, the liquid solvent enters the reboiler 513a (lower heat), where it is heated to form liquid solvent 511a (slightly warm, CO2 semilean solvent). Vapor 514a (lower heat) is formed in the reboiler 513a (lower heat) and has a temperature of 60°C to less than 120°C.

[0181] The liquid solvent 511a (slightly warm, CO2 semi-lean solvent) enters the first crossover heat exchanger 510a, where it is cooled by heat exchange with the liquid solvent 508 (cold, CO2-rich solvent). The liquid solvent 506a (cold, CO2 semi-lean solvent) is reformed, and the absorption process can be restarted.

[0182] The liquid solvent 506a (cold, CO2 semi-lean solvent) can pass through an additional cooler before entering the first absorption column 505a.

[0183] When flue gas 501 reaches the top of the first absorption column 505a, its CO2 content is partially depleted, and flue gas 501a (with partially depleted CO2) is formed.

[0184] In the second liquid solvent circuit of system 500, flue gas 501a (partially depleted of CO2) comes into contact with liquid solvent 506 (cold, CO2-lean solvent) in the second absorption column 505b to form liquid solvent 508a (cold, CO2-semi-rich solvent).

[0185] Liquid solvent 508a (cold, CO2 semi-rich solvent) enters the second crossover heat exchanger 510b, where it is heated by the heat from liquid solvent 511 (warm, CO2 lean solvent). Liquid solvent 512 (warm, CO2 semi-rich solvent) is formed.

[0186] The liquid solvent 512 (warm, CO2 semi-rich solvent) enters the regenerator 509 (higher heat), and the reaction between CO2 and the liquid solvent is reversed using vapor 514 (higher heat). Typically, vapor 514 (higher heat) flows upward through the regenerator 509 (higher heat) and flows back against the liquid solvent 512 (warm, CO2 semi-rich solvent). Gaseous CO2 515 is formed and exits from the top of the regenerator 509 (higher heat).

[0187] Gaseous CO2515 exits the top of regenerator 509 (high heat). Gaseous CO2515 can be used in downstream applications.

[0188] Next, the liquid solvent enters the reboiler 513 (high heat), where it is heated. Upon heating, vapor 514 (high heat) and liquid solvent 511 (warm, CO2 lean solvent) are formed. The vapor 514 (high heat) is typically at a temperature of 120-135°C.

[0189] The liquid solvent 511 (warm, CO2 lean solvent) enters the second crossover heat exchanger 510b, where it is cooled by the liquid solvent 508a (cold, CO2 semi-rich solvent). The liquid solvent 506 (cold, CO2 lean solvent) is reformed, allowing the absorption process to resume.

[0190] The liquid solvent 506 (cold CO2 lean solvent) can pass through an additional cooler before entering the second absorption column 405b.

[0191] When flue gas 501a (partially depleted of CO2) reaches the top of the second absorption column 505b, the CO2 is depleted and flue gas flow 507 is formed (CO2 is depleted). Flue gas 507 (CO2 depleted) is released from the top of the second absorption column 505b.

[0192] Compared to typical CO2 capture methods, the System 500 configuration advantageously divides the liquid solvent between at least two regenerators operating at at least two temperatures.

[0193] The configuration of System 500 replaces the higher heat (typically in the temperature range of 120°C to 135°C) with the lower heat (in the temperature range of 60°C to below 120°C).

[0194] The configuration of System 500 reduces the required high-temperature energy by 40-50%.

[0195] The System 500 configuration reduces the decomposition of solvent components by shortening the residence time of the solvent in the regenerator (high heat).

[0196] The configuration of System 500 reduces operating costs by reducing the required high-level thermal requirements.

[0197] The configuration of System 500 typically divides the liquid solvent into two equal flows, thereby reducing the need for frequently used high-level heat regenerators. Optionally, the division between the low-level and high-level heat circuits is 75:25 (expressed as a ratio in weight percent or volume percent).

[0198] System 500 typically removes 30-90% (by weight) of CO2 from flue gas 501, and typically removes 85% (by weight) of CO2 from flue gas 501. Higher and lower removal rates can be achieved by adjusting process parameters.

[0199] The following is a non-limiting example illustrating the advantages of using the system and method of the present invention, with reference to graphs in specific figures. System 600: The present invention's system and method using a single regenerator, two parallel reboilers, and a single absorption column.

[0200] Figure 6 is a schematic diagram of a system 600 used to recover CO2 from flue gas according to the present invention.

[0201] In system 600, flue gas 601 containing CO2 enters system 600 at a temperature typically of 100°C. The flue gas 601 passes through a booster fan and a direct contact cooler (not shown) as needed, where it is cooled to a temperature typically of 40°C.

[0202] Flue gas 601 enters absorption column 605, where it back-flows into contact with liquid solvent 606 (cold, CO2-lean solvent). Flue gas 601 rises through absorption column 605. Liquid solvent 606 (cold, CO2-lean solvent) enters absorption column 605 via a liquid partition (not shown in Figure 6) located at the top of absorption column 605 and cascades downward through absorption column 605. Absorption column 605 contains packing to maximize the ratio of surface area to volume. Components in liquid solvent 606 (cold, CO2-lean solvent) react with CO2 in CO2-rich flue gas 601.

[0203] When it reacts with CO2 in the CO2-rich flue gas 601, the liquid solvent 606 (cold, CO2-lean solvent) becomes CO2-rich, forming the liquid solvent 608 (cold, CO2-rich solvent).

[0204] When flue gas 601 reaches the top of absorption column 605, the CO2 is depleted, forming flue gas 607 (lean CO2). Flue gas 607 (lean CO2) is released from the top of absorption column 605.

[0205] Liquid solvent 608 (cold, CO2-rich solvent) is regenerated in regenerator 609 (low and high heat) at both low and high heat and modified into liquid solvent 606 (cold, CO2-lean solvent).

[0206] The liquid solvent 608 (cold, CO2-rich solvent) enters the regenerator 609 (low and high heat) via the crossover heat exchanger 610. In the crossover heat exchanger 610, Liquid solvent 608 (cold, CO2-rich solvent) is heated by liquid solvent 611 (warm, CO2-rich solvent) to form liquid solvent 612 (warm, CO2-rich solvent).

[0207] Liquid solvent 612 (warm, CO2-rich solvent) enters the upper part of regenerator 609 (low and high heat) and cascades downwards through regenerator 609 (low and high heat). Within regenerator 609 (low and high heat), liquid solvent 612 (warm, CO2-rich solvent) is heated by contact with vapor 614 (high heat) and vapor 614a (low heat). Typically, vapor 614 (high heat) and vapor 614a (low heat) flow upward through regenerator 609 (low and high heat), and are flowing backward against liquid solvent 612 (warm, CO2-rich solvent). Vapor 614a (low heat) is typically at a temperature of 60°C to less than 120°C, while vapor 614 (high heat) is typically at a temperature of 120°C to 135°C. When heated, the reaction between the active component of the liquid solvent and CO2 reverses, releasing CO2 gas 615 and forming liquid solvent 611 (warm, CO2 lean solvent).

[0208] Gaseous CO2615 exits the top of regenerator 609 (lower heat). Gaseous CO2615 can be used in downstream processes.

[0209] The liquid solvent 611 (warm, lean CO2 solvent) is divided and supplied to two parallel reboilers, reboiler 613 (high heat) and reboiler 613a (low heat). The division ratio is determined by (a) the quality of the heat supplied to the regenerator, (b) the difference in value between the low heat source and the high heat source, and (c) the required amount of CO2 recovery. In reboiler 613 (high heat), the liquid solvent 611 (warm, lean CO2 solvent) boils to form steam 614 (high heat). In reboiler 613a (low heat), the liquid solvent 611 (warm, lean CO2 solvent) boils to form steam 614a (low heat). Steam 614 (high heat) and steam 614a (low heat) are used in regenerator 609 (low and high heat).

[0210] Liquid solvent 611 (warm, CO2-lean solvent) enters the crossover heat exchanger 610 and is cooled by contact with liquid solvent 608 (cold, CO2-rich solvent) to form liquid solvent 606 (cold, CO2-lean solvent). The newly formed liquid solvent 606 (cold, CO2-lean solvent) is ready to repeat the absorption process.

[0211] The liquid solvent 606 (cold, CO2 lean solvent) can pass through an additional condenser (not shown) before entering the absorption column 605.

[0212] Compared to typical CO2 recovery methods, the configuration of the present invention (for example, the configuration described with reference to Figure 6) advantageously utilizes both high and low heat in a single regenerator column. Low heat may be (but not limited to) low-pressure steam or process flow from a downstream processing unit that converts CO2 into chemical products such as methanol.

[0213] The configuration of system 600 replaces some of the higher heat (typically in the temperature range of 120°C to 135°C) with lower heat in the temperature range of 60°C to below 120°C. If lower heat is unavailable for a certain period, the total thermal load (low and higher heat) of the regenerator 609 can be met using only the higher heat. Similarly, it is also possible to operate using only lower heat without using the higher heat.

[0214] The configuration of System 600 reduces the higher heat required to regenerate the liquid solvent by 50–90%, typically 80%, (compared to the system in Figure 1 where only higher heat is used).

[0215] The System 600 configuration mitigates the decomposition of solvent components by lowering the required temperature. This maximizes the lifespan of the solvent used in the system.

[0216] The System 600 configuration reduces operating costs by decreasing the load requiring more expensive high-temperature energy.

[0217] The System 600 configuration typically removes 30-90% (by weight) of CO2 from CO2-rich flue gas 601, or typically removes 85% (by weight) of CO2 from CO2-rich flue gas 601. Higher or lower removal can be achieved by adjusting the process parameters. System 700: The present invention's system and method using a single regenerator with a bottom reboiler, a side reboiler and a single absorption column.

[0218] Figure 7 is a schematic diagram of a system 700 used to recover CO2 from flue gas according to the present invention.

[0219] In system 700, flue gas 701 containing CO2 enters system 700 at a temperature typically of 100°C. The flue gas 701 passes through a booster fan and a direct contact cooler (not shown) as needed, where it is cooled to a temperature typically of 40°C.

[0220] Flue gas 701 enters the absorption column 705, where it enters backflow contact with liquid solvent 706 (cold, lean CO2 solvent). Flue gas 701 rises through the absorption column 705. Liquid solvent 706 (cold, lean CO2 solvent) enters the absorption column 705 via a liquid partition (not shown in Figure 7) located at the top of the absorption column 705 and cascades downward through the absorption column 705. The absorption column 705 contains packing to maximize the ratio of surface area to volume. Active components in liquid solvent 706 (cold, lean CO2 solvent) react with CO2 in flue gas 701.

[0221] When the liquid solvent 706 (cold, CO2-lean solvent) reaches the bottom of the absorption column 705, it becomes CO2-rich and forms liquid solvent 708 (cold, CO2-rich solvent).

[0222] When flue gas 701 reaches the top of absorption column 705, the CO2 is depleted, forming flue gas 707 (lean CO2). Flue gas 707 (lean CO2) is released from the top of absorption column 705.

[0223] Liquid solvent 708 (cold, CO2-rich solvent) is regenerated in regenerator 709 (low and high heat) at both low and high heat, modifying liquid solvent 706 (cold, CO2-lean solvent). Liquid solvent 708 (cold, CO2-rich solvent) enters regenerator 709 (low heat) via crossover heat exchanger 710. In crossover heat exchanger 710, liquid solvent 708 (cold, CO2-rich solvent) is heated by liquid solvent 711 (warm, CO2-rich solvent) to form liquid solvent 712 (warm, CO2-rich solvent).

[0224] The liquid solvent 712 (warm, CO2-rich solvent) enters the upper part of the regenerator 709 (low and high heat) and cascades downwards through the regenerator 709. Within the regenerator 709, the liquid solvent 712 is heated by contact with vapor 714 (high heat) and vapor 714a (low heat). Typically, vapor 714 and vapor 714a flow upwards through the regenerator 709, flowing back against the liquid solvent 712. Vapor 714a is typically between 60°C and below 120°C, while vapor 714 is typically between 120°C and 135°C. When heated, the reaction between the active component of the liquid solvent and CO2 reverses, releasing CO2 gas 715, and the liquid solvent 711 (warm) A CO2 lean solvent is formed.

[0225] Gaseous CO2715 exits the top of regenerator 709 (low and high heat). Gaseous CO2715 can be used in downstream processes.

[0226] At an intermediate point between the liquid solvent 712 (warm, CO2-rich solvent) supply point and the regenerator 709 (low and high heat), a portion of the liquid solvent 712 (warm, CO2-rich solvent) is withdrawn as a side draw and sent to the reboiler 713a (low heat). The amount of side draw liquid is determined by (a) the quality of the heat supplied to the regenerator, (b) the difference in value between the low and high heat sources, and (c) the required amount of CO2 recovery. The portion of the side draw liquid can be 0% to 100% of the liquid solvent 712 (warm, CO2-rich solvent). In the reboiler 713a (low heat), the liquid solvent 711 (warm, lean CO2 solvent) boils, and vapor 714a (low heat) is formed.

[0227] The liquid solvent 711 (warm, CO2 lean solvent) is supplied to the reboiler 713 (high heat). The reboiler 713 (high heat) is positioned towards the bottom of the regenerator 709 (low and high heat), preferably below the supply position of the reboiler 713a (low heat). Inside the reboiler 713 (high heat), the liquid solvent 711 (warm, CO2 lean solvent) boils, forming vapor 714 (high heat). The vapor 714 (high heat) and vapor 714a (low heat) are used in the regenerator 709 (low heat).

[0228] The liquid solvent 711 (warm, CO2-lean solvent) enters the crossover heat exchanger 710 and is cooled by contact with the liquid solvent 708 (cold, CO2-rich solvent) to form the liquid solvent 706 (cold, CO2-lean solvent). The newly formed liquid solvent 706 (cold, CO2-lean solvent) is ready to repeat the absorption process.

[0229] The liquid solvent 706 (cold, CO2 lean solvent) can pass through an additional condenser (not shown) before entering the absorption column 705.

[0230] Compared to typical CO2 recovery methods, the configuration of the present invention (for example, the configuration described with reference to Figure 7) advantageously utilizes both high and low heat in a single regenerator column. Low heat may be (but not limited to) low-pressure steam or process flow from downstream processing units that convert CO2 into chemical products such as methanol.

[0231] The configuration of System 700 replaces a portion of the higher heat (typically in the temperature range of 120°C to 135°C) with lower heat in the temperature range of 60°C to less than 120°C. If lower heat is unavailable for a certain period, the total heat load (low and higher heat) of the regenerator 709 can be met using only the higher heat.

[0232] The configuration of System 700 reduces the higher heat required to regenerate the liquid solvent by 50–90%, typically 80%, (compared to the system in Figure 1 where only higher heat is used).

[0233] The System 700 configuration mitigates the decomposition of solvent components by lowering the required temperature. This maximizes the lifespan of the solvent used in the system.

[0234] The System 700 configuration reduces operating costs by decreasing the load requiring more expensive high-temperature energy.

[0235] The System 700 configuration typically removes 30% to 90% (by weight) of CO2 from flue gas 701, or typically removes 85% (by weight) of CO2 from flue gas 701. By adjusting the process parameters, higher or lower removal levels can be achieved. System 800: The present invention relating to a system and method using a single regenerator, hydrogen, and a single absorption column.

[0236] Figure 8 is a schematic diagram of a system 800 used to recover CO2 from flue gas according to the present invention.

[0237] In system 800, flue gas 801 containing CO2 enters the system 800 at a temperature typically of 100°C. The flue gas 801 passes through a booster fan and a direct contact cooler as needed, where it is cooled to a temperature typically of 40°C.

[0238] Flue gas 801 enters absorption column 805, where it enters backflow contact with liquid solvent 806 (cold, lean CO2 solvent). Flue gas 801 rises through absorption column 805. Liquid solvent 806 (cold, lean CO2 solvent) enters absorption column 805 via a liquid partition (not shown in Figure 8) located at the top of absorption column 805 and cascades downward through absorption column 805. Absorption column 805 contains packing to maximize the ratio of surface area to volume. Active components in liquid solvent 806 (cold, lean CO2 solvent) react with CO2 in flue gas 801.

[0239] When liquid solvent 806 (cold, CO2-lean solvent) reaches the bottom of absorption column 805, it becomes CO2-rich and forms liquid solvent 808 (cold, CO2-rich solvent).

[0240] When flue gas 801 reaches the top of absorption column 805, the CO2 is depleted, forming flue gas 807 (lean CO2). Flue gas 807 (lean CO2) is released from the top of absorption column 805.

[0241] Liquid solvent 808 (cold, CO2-rich solvent) is regenerated at lower heat in regenerator 809, modifying liquid solvent 806 (cold, CO2-lean solvent). Liquid solvent 808 (cold, CO2-rich solvent) enters regenerator 809 (lower heat) via crossover heat exchanger 810. In crossover heat exchanger 810, liquid solvent 808 (cold, CO2-rich solvent) is heated by liquid solvent 811 (warm, CO2-lean solvent) to form liquid solvent 812 (warm, CO2-rich solvent).

[0242] Liquid solvent 812 (warm, CO2-rich solvent) enters the upper part of regenerator 809 (lower heat) and cascades downwards through regenerator 809 (lower heat). Inside regenerator (lower heat), liquid solvent 812 (warm, CO2-rich solvent) is heated by contact with vapor 814 (lower heat). Typically, vapor 814 (lower heat) flows upward through regenerator 809 (lower heat) and flows back against liquid solvent 812 (warm, CO2-rich solvent). Vapor 814 (lower heat) is typically at a temperature of 60°C to less than 120°C. Upon heating, the reaction between the active components of the liquid solvent and CO2 reverses, releasing CO2 gas 815 and forming liquid solvent 811 (warm, CO2-lean solvent).

[0243] Gaseous CO2815 exits from the top of regenerator 809 (lower heat). Gaseous CO2815 can be used in downstream processes.

[0244] Liquid solvent 811 (warm, CO2-lean solvent) is supplied to a reboiler 813 (low-temperature heat). Depending on the availability of low-temperature heat, similar to the arrangement shown in Fig. 4 or Fig. 5, high-temperature heat (not shown) can be used to operate a second reboiler. In the reboiler 813 (low-temperature heat), the liquid solvent 811 (warm, CO2-lean solvent) boils to form vapor 814 (low-temperature heat). The vapor 814 (low-temperature heat) is used in a regenerator 809 (low-temperature heat). Hydrogen g as 816 is supplied to the reboiler 813 (low-temperature heat) to facilitate vaporization. Hydrogen gas 816 may also (or alternatively) be supplied directly to the regenerator 809 (low-temperature heat). Depending on the pressure of the hydrogen gas 816, a hydrogen compressor 817 may be required to increase the pressure to the operating pressure of the regenerator 809 (low-temperature heat).

[0245] Liquid solvent 811 (warm, CO2-lean solvent) enters a crossover heat exchanger 810 and is cooled by contacting with liquid solvent 808 (cold, CO2-rich solvent), forming liquid solvent 806 (cold, CO2-lean solvent). The newly formed liquid solvent 806 (cold, CO2-lean solvent) is ready to repeat the absorption process again.

[0246] Liquid solvent 806 (cold, CO2-lean solvent) may pass through an additional cooler (not shown) before entering the absorption column 805.

[0247] Compared with a typical CO2 capture method, the arrangement of the present invention (e.g., the arrangement described with reference to Fig. 8) advantageously utilizes hydrogen gas together with low-temperature heat in a single regenerator column. Low-temperature heat can be (but is not limited to) low-pressure vapor, or a process stream from a downstream processing unit that converts CO2 into chemical products such as methanol, etc.

[0248] The system 800 is configured to use hydrogen gas 816 to lower the temperature of the fluid at the bottom of the regenerator 809 (lower heat). The molar flow rate ratio of hydrogen gas 816 is up to four times that of gaseous CO2 815. In this way, all the higher heat (typically in the temperature range of 120-135°C) can be replaced with lower heat in the temperature range of 60-120°C. If lower heat is unavailable for a certain period, only higher heat can be used, either in the reboiler 813 (lower heat) or in another reboiler that uses higher heat (not shown) to meet the total heat requirements of the regenerator 809 (lower heat).

[0249] The configuration of System 800 reduces the higher heat required to regenerate the liquid solvent by up to 100% (compared to the system in Figure 1 where only higher heat is used).

[0250] The System 800 configuration mitigates the decomposition of solvent components by lowering the required temperature. This maximizes the lifespan of the solvent used in the system.

[0251] The System 800 configuration reduces operating costs by eliminating the use of more expensive higher heat.

[0252] The System 800 typically removes 30% to 90% (by weight) of CO2 from flue gas 801, or typically removes 85% (by weight) of 8O2 from flue gas 801. Higher or lower removal can be achieved by adjusting the process parameters. Example 1: System (System 200) and method of the present invention compared to System 100

[0253] In a non-limiting example of the present invention, system 200 was compared with system 100.

[0254] In this non-limiting example of the present invention, CDRMax solvent (sold by Carbon Clean Solutions Ltd) was used in systems 100 and 200.

[0255] In this non-limiting example of the present invention, systems 100 and 200 are configured to remove 85% (by weight) of CO2 from flue gas containing 5 mol% CO2.

[0256] In this non-limiting example of the present invention, system 100 used a regenerator that operates using high heat at temperatures exceeding 120°C.

[0257] Systems 100 and 200 achieved 100% regeneration of the liquid solvent.

[0258] In this non-limiting example of the present invention, system 200 used two regenerators. One regenerator operated using lower heat at a temperature of 105°C, and the second regenerator operated using higher heat at a temperature of 120°C.

[0259] In this non-limiting example of the present invention, in system 200, 35% (by weight) of the liquid solvent passed through a regenerator operating at a temperature of 105°C, while 65% (by weight) of the liquid solvent passed through a regenerator operating at a temperature of 120°C.

[0260] The results for this non-limiting example are plotted in Figure 9. Figure 9 plots the specific reboiler load (SRD) from high heat use in CDRMax solvent regeneration as a function of total solvent stock (both low heat and high heat regeneration) and flue gas L / G (by weight).

[0261] Figure 9 shows that system 200 removes 85% (by weight) of CO2 from the liquid solvent and reduces the reboiler (higher heat) load by 25-30% compared to system 100.

[0262] Figure 9 shows that system 200 removes CO2 from a liquid solvent, preferably when the liquid solvent has a high CO2 concentration. This is because more CO2 is removed from the liquid solvent by lower heat compared to a liquid solvent with a low CO2 concentration. Example 2: Systems and methods of the present invention, wherein two streams of liquid solvent remain hydraulically independent (System 300), in comparison with Systems 100 and 200

[0263] In a non-limiting example of the present invention, System 300 is compared with Systems 100 and 200.

[0264] In this non-limiting example of the present invention, CDRMax was used in simulations of Systems 100, 200, and 300. The simulations were performed with software named ProMax® provided by Bryan Research. ProMax® is an industry standard software used for simulation of CO2 capture processes and systems, among other things.

[0265] Systems 100, 200, and 300 were configured to remove 85% by weight of CO2 from flue gas containing 5 mol% of CO2.

[0266] In this non-limiting example of the present invention, System 100 uses a regenerator that operates using high-grade heat at a temperature of 120°C.

[0267] In this non-limiting example of the present invention, Systems 200 and 300 each use two regenerators. One regenerator operates using low-grade heat at a temperature of 105°C, and the second regenerator operates using high-grade heat at a temperature of 120°C.

[0268] In this non-limiting example of the present invention, 35% by weight of the liquid solvent passes through the regenerator operating at 105°C, while 65% by weight of the liquid solvent passes through the regenerator operating at 120°C in System 200.

[0269] In this non-limiting example of the present invention, two simulations of System 300 were created. The simulations were performed with ProMax® provided by Bryan Research It was run using software named ProMax® (a registered trademark). ProMax® is an industry-standard software used, among other things, for simulating CO2 capture methods and systems.

[0270] In the first simulation, 40–64% (by weight) of the liquid solvent passed through a regenerator operating at 105°C, while 36–60% (by weight) passed through a regenerator operating at 120°C. In the second simulation, 60–83% (by weight) of the liquid solvent passed through a regenerator operating at 105°C, while 17–40% (by weight) passed through a regenerator operating at 120°C. Since the two circuits of System 300 are hydrodynamically independent, the percentage of liquid solvent passing through each regenerator represents a percentage of the total solvent stock.

[0271] The results of this non-limiting example of the present invention are shown in Figure 10. Figure 10 compares systems 100, 200, and 300. Figure 10 plots specific reboiler loads (SRD) from high heat usage in CDRMax solvent regeneration for systems 100, 200, and 300 as a function of total solvent stock (both low heat and high heat regeneration) and flue gas L / G (by weight).

[0272] Figure 10 shows that when the liquid solvent in system 300 is divided in a ratio of 40-64:36-60 (expressed as a weight percentage), passing it through regenerators operating at lower and higher temperatures respectively improves the higher temperature SRD compared to systems 100 and 200.

[0273] Figure 10 shows that when the liquid solvent in system 300 is divided in a ratio of 60-83:17-40, the ratios can be weight % or volume % through regenerators operating at lower and higher heat, respectively, and there is an improvement in the higher heat SRD divided in a ratio of 40-64:36 to 60 compared to systems 100, 200, and 300, and this ratio can be weight % or volume %.

[0274] Figure 10 shows that system 300 can independently optimize the CO2 load of the liquid solvent in the semi-lean and lean sections of system 300.

[0275] Figure 10 shows that system 300 can independently optimize the flow rate of the liquid solvent in the semi-lean and lean sections of system 300.

[0276] Figure 10 shows that system 300 provides a single design that offers the ability to shift between lower and higher heat levels simply by changing the process.

[0277] Figure 10 shows that the combination of lower heat and thermal integration in system 300 reduces the reboiler load by 60%. Example 3: A system and method of the present invention in which the liquid solvent is divided between a lower heat regenerator and a higher heat regenerator (system 400), compared to systems 100, 200, and 300.

[0278] In a non-limiting example of the present invention, system 400 is compared with systems 100, 200, and 300.

[0279] In this non-limiting example of the present invention, CDRMax solvent was used in systems 100, 200, 300, and 400.

[0280] In this non-limiting example of the present invention, systems 100, 200, 300, and 400 are configured to remove 85% (by weight) of CO2 from flue gas containing 5 mol% CO2. Ta.

[0281] In this non-limiting example of the present invention, system 100 used a regenerator that operates using high heat at a temperature of 120°C.

[0282] In this non-limiting example of the present invention, systems 200, 300, and 400 used two regenerators. One regenerator operated using lower heat at a temperature of 105°C, and the second regenerator operated using higher heat at a temperature of 120°C.

[0283] In this non-limiting example of the present invention, 35% (by weight) of the liquid solvent passed through a regenerator operating at a temperature of 105°C, while 65% (by weight) of the liquid solvent passed through a regenerator operating at a temperature of 120°C in system 200.

[0284] In this non-limiting example of the present invention, 60–83% (by weight) of the liquid solvent passed through a regenerator operating at a temperature of 105°C, while 17–40% (by weight) of the liquid solvent passed through a regenerator operating at a temperature of 120°C in System 300. Since the two circuits of System 300 are hydrodynamically independent, the proportion of liquid solvent passing through each regenerator represents a percentage of the total solvent stock.

[0285] In this non-limiting example of the present invention, 20–25% (by weight) of the liquid solvent passed through a regenerator operating at a temperature of 105°C, while 75–80% (by weight) of the liquid solvent passed through a regenerator operating at a temperature of 120°C in system 400. The lower thermal solvent circuit operates at maximum capacity with a constant solvent flow rate. Variations in the rate of lower thermal regeneration are due to variations in the flow rate of the higher thermal regeneration circuit, and consequently, variations in the overall solvent flow rate.

[0286] In this non-limiting example of the present invention, the solvent flows are thermally independent of each other, and therefore the higher thermal integration is independent.

[0287] Figure 11 compares systems 100, 200, 300, and 400. Figure 11 plots specific reboiler loads (SRD) from high heat usage in CDRMax solvent regeneration for systems 100, 200, 300, and 400 as a function of total solvent stock (both low heat and high heat regeneration) and flue gas L / G (by weight).

[0288] Figure 11 shows that system 400 reduces high-level thermal SRD compared to systems 100 and 200. Example 4: Compared to systems 100, 200, 300, and 400, the two absorption columns and two regenerators are hydrodynamically and thermally independent (system 500). System and method of the present invention.

[0289] In a non-limiting example of the present invention, system 500 is compared to systems 100, 200, 300, and 400.

[0290] In this non-limiting example of the present invention, CDRMax solvent was used in systems 100, 200, 300, 400, and 500.

[0291] In this non-limiting example of the present invention, systems 100, 200, 300, 400, and 500 are configured to remove 85% (by weight) of CO2 from flue gas containing 5 mol% CO2.

[0292] In this non-limiting example of the present invention, system 100 uses high heat at a temperature of 120°C. A regenerator that operates on this principle was used.

[0293] In this non-limiting example of the present invention, systems 200, 300, 400, and 500 used two regenerators. One regenerator operated using lower heat at a temperature of 105°C, and the second regenerator operated using higher heat at a temperature of 120°C.

[0294] In this non-limiting example of the present invention, 35% (by weight) of the liquid solvent passed through a regenerator operating at a temperature of 105°C, while 65% (by weight) of the liquid solvent passed through a regenerator operating at a temperature of 120°C in system 200.

[0295] In this non-limiting example of the present invention, 60–83% (by weight) of the liquid solvent passed through a regenerator operating at a temperature of 105°C, while 17–40% (by weight) of the liquid solvent passed through a regenerator operating at a temperature of 120°C in System 300. Since the two circuits of System 300 are hydrodynamically independent, the percentage of liquid solvent passing through each regenerator represents a percentage of the total solvent stock.

[0296] In this non-limiting example of the present invention, 20–25% (by weight) of the liquid solvent passed through a regenerator operating at a temperature of 105°C, while 75–80% (by weight) of the liquid solvent passed through a regenerator operating at a temperature of 120°C in system 400. The lower thermal solvent circuit operates at maximum capacity with a constant solvent flow rate. Variations in the rate of lower thermal regeneration are due to variations in the flow rate of the higher thermal regeneration circuit, and consequently, variations in the overall solvent flow rate.

[0297] In this non-limiting example of the present invention, 56 to 82% (by weight) of the liquid solvent passed through a regenerator operating at a temperature of 105°C, while 18 to 44% (by weight) of the liquid solvent passed through a regenerator operating at a temperature of 120°C in System 500. Since the two circuits of System 500 are hydrodynamically independent, the percentage of liquid solvent passing through each regenerator represents a percentage of the total solvent stock.

[0298] Figure 12 compares systems 100, 200, 300, 400, and 500. Figure 12 plots specific reboiler loads (SRD) from high heat usage in CDRMax solvent regeneration for systems 100, 200, 300, 400, and 500 as a function of total solvent stock (both low heat and high heat regeneration) and flue gas L / G (by weight).

[0299] Figure 12 shows that system 500 reduces the upper heat SRD compared to system 100, while significantly reducing the use of lower heat. Example 5: CO2 removal rate from flue gas containing various amounts of CO2 as a function of the ratio of the weight percentage of the liquid solvent to the weight percentage of the gas.

[0300] In one non-limiting example of the present invention, the CO2 removal rate from flue gas was simulated as a function of the weight ratio of liquid to gas.

[0301] In this non-limiting example of the present invention, the system consisted of a single regenerator operating at different temperature setpoints.

[0302] In this non-limiting example of the present invention, CDRMax solvent was used.

[0303] The results of the present invention are shown in Figures 13, 14, and 15. Figures 13, 14, and 15 are graphs showing the removal efficiency (percentage of CO2 recovered from the total CO2 present in the flue gas) as a function of the liquid-to-gas ratio (L / G) and the temperature of the heat used for solvent regeneration.

[0304] In this non-limiting example, the regenerator temperature was changed three times to compare the effect of temperature on the CO2 removal rate from combustion exhaust gas.

[0305] In this non-limiting example, the regenerator temperatures were simulated to be 120°C, 105°C, and 90°C.

[0306] It was found that the CO2 load on the liquid solvent after passing through the regenerator is limited by the regeneration temperature.

[0307] If the regenerator temperature is simulated to be 120°C, the CO2 load of the CO2 lean liquid solvent will be 0.16 mol / L. -1 On the other hand, if the regenerator temperature was simulated to be 105°C, the CO2 load of the CO2 lean liquid solvent would be 0.29 mol / L. -1 Therefore, if the regenerator temperature is simulated to be 90°C, the CO2 load will be 0.45 mol L of lean CO2 liquid solvent. -1 That was the case. Comparison 1: 15 molar %CO2 flue gas

[0308] In this non-specific example, the CO2 concentration in the flue gas was set to 15 mol%.

[0309] In Figure 13, the removal of CO2 from flue gas containing 15 mol% CO2 is plotted as a function of L / G. As shown in Figure 13, using a regenerator operating at lower heat results in a recovery efficiency of less than 90% (a recovery efficiency of 90% was achieved with a higher heat system).

[0310] To achieve maximum removal, increase the L / G ratio in the lower heat regeneration system (i.e., increase the CDRMax solvent flow rate). Comparison 2: 9 mol% CO2 flue gas

[0311] In this non-specific example, the CO2 concentration in the flue gas was set to 9 mol%.

[0312] In Figure 14, the removal of CO2 from flue gas containing 9 mol% CO2 is plotted as a function of L / G. As shown in Figure 14, using a regenerator operating at lower heat results in lower recovery efficiency than that achievable with higher heat regeneration. In this case, regeneration at 90°C achieves only about 75% (by weight) of CO2 removal from the flue gas.

[0313] To achieve maximum removal, increase the L / G ratio in the lower heat regeneration system (i.e., increase the CDRMax solvent flow rate). Comparison 3: 5 mol % CO2 flue gas

[0314] In this non-specific example, the CO2 concentration in the flue gas was set to 5 mol%.

[0315] In Figure 15, the removal of CO2 from flue gas containing 5 mol% CO2 is plotted as a function of L / G. As shown in Figure 15, using a regenerator operating at lower heat results in lower recovery efficiency than that achievable with higher heat regeneration. In this case, regeneration at 90°C achieves only about 65% (by weight) of CO2 removal from the flue gas.

[0316] To achieve maximum removal, increase the L / G ratio in the lower heat regeneration system (i.e., increase the CDRMax solvent flow rate). Conclusion of the comparison

[0317] Figures 13, 14, and 15 show that the CO2 concentration in the flue gas decreases from 15 mol% to 5 mol%. As a result, the system becomes limited by the equilibrium concentration of the lean solution, known as the "lean pinch," which reduces the recovery efficiency.

[0318] At higher heats, the effects of lean pinch are not very noticeable, and a recovery efficiency of approximately 85% (by weight) can still be obtained with 5 mol% CO2 flue gas.

[0319] For 105°C and 90°C, the amount is 0.29 mol / L. -1 and 0.45 mol L -1 Each lean load significantly limits removal efficiency due to equilibrium constraints. Lower heat alone cannot achieve the overall removal efficiency typically required in the industry.

[0320] The currently claimed invention combines lower and higher heat to meet the generally required removal efficiency of 85% (by weight) or more and to reduce the overall requirement of higher heat. The currently claimed invention provides a beneficial method and system that can be used to regenerate lean carbon dioxide solvents in carbon capture processes. The combination of lower and higher heat in the currently claimed method and system provides a beneficial option for carbon capture plants. Conventional methods and systems have limitations in regenerating lean carbon dioxide solvents using only higher heat.

[0321] The use of low-temperature regenerators and low-temperature reboilers is particularly applicable to waste from power plants. Waste from power plants provides energy and heating to cities. During the summer, high-temperature heat is readily available. However, during the winter, only low-temperature heat is available, as the use of high-temperature heat is limited due to internal processes used for heating. Utilizing such low-temperature heat in the methods and systems of the currently claimed invention is particularly beneficial.

[0322] As used herein and in the claims, the terms “contains” and “contains” and their variations mean that a particular feature, process, or integer is included. These terms should not be construed to exclude the existence of other features, processes, or components.

[0323] The features disclosed in the above description, the following claims, or the accompanying drawings are expressed in a particular form, or in terms of means for performing the disclosed functions, or methods or processes for achieving the disclosed results, and can be used, individually or in any combination thereof, as necessary to realize the invention in its various forms.

Claims

1. Carbon dioxide (CO2) ２ A method for regenerating a solvent containing ), wherein the method is Carbon dioxide (CO2) ２ To provide a solvent containing ) Carbon dioxide (CO2) ２ The solvent containing ) is passed through a single lower heat and upper heat combined regenerator, the single lower heat and upper heat combined regenerator comprising a lower heat regenerator and an upper heat regenerator, wherein the lower heat regenerator operates at a temperature in the range of 60°C to less than 120°C and the upper heat regenerator operates at a temperature of 120°C or higher, and carbon dioxide (CO2) is passed through the single lower heat and upper heat combined regenerator. ２ ) forming a lean solvent, The aforementioned carbon dioxide (CO2) ２ ) Passing a lean solvent through a low-temperature reboiler, wherein the low-temperature reboiler operates at a temperature in the range of 60°C to less than 120°C, The aforementioned carbon dioxide (CO2) ２ ) Passing a lean solvent through a high-temperature reboiler, wherein the high-temperature reboiler operates at a temperature of 120°C or higher, A method including, The aforementioned lower heat and higher heat combined regenerator, the lower heat reboiler, and the higher heat reboiler utilize carbon dioxide (CO2). ２ A method in which a solvent containing ) is fluidly communicated between each component.

2. The method according to claim 1, wherein the lower heat regenerator operates at a temperature in the range of 100 to 119°C or 100 to 115°C.

3. The method according to claim 1 or claim 2, wherein the lower heat reboiler operates at a temperature in the range of 100 to 119°C or 100 to 115°C.

4. The method according to any one of claims 1 to 3, wherein the high-temperature regenerator operates at a temperature of 120°C to 140°C.

5. The method according to any one of claims 1 to 4, wherein the high-temperature reboiler operates at a temperature of 120°C to 140°C.

6. The aforementioned lower heat and higher heat combined regenerator and the lower heat reboiler utilize carbon dioxide (CO2). ２ )of The solvent is fluidly connected to the lower heat and higher heat combined regenerator and the lower heat reboiler; and / or, The composite regenerator of low-grade heat and high-grade heat and the high-grade heat reboiler are configured to release carbon dioxide (CO ２ )-containing solvent to flow between said composite regenerator of low-grade heat and high-grade heat and said high-grade heat reboiler in fluid communication, the method according to any one of claims 1 to 5.

7. The method according to any one of claims 1 to 6, wherein a gas that does not dissolve or react with the solvent (optionally, an inert gas such as hydrogen or nitrogen) is introduced into the lower heat reboiler and / or the lower heat regenerator to lower the temperature of the lower heat reboiler and / or the lower heat regenerator, thereby enabling the use of lower heat alone or a combination of lower heat and higher heat.

8. Carbon dioxide (CO2) ２ Providing a solvent containing CO ２ Rich solvent, optional, 2 to 3.3 mol L －１ CO2 ２ The method according to any one of claims 1 to 7, comprising providing a rich solvent.

9. The carbon dioxide (CO) formed above ２ ) Lean solvent, 0.0 to 0.7 mol L －１ Carbon dioxide concentration (CO2) ２ The method according to any one of claims 1 to 8, wherein the solvent is lean.

10. Carbon dioxide (CO2) ２ To provide a solvent containing ) In one, two, three, four, five, six, seven, eight, nine, or ten or more absorption columns, flue gas is converted to carbon dioxide (CO2). ２ The method according to any one of claims 1 to 9, comprising contacting the absorption column with a lean solvent, wherein the absorption column is in fluid communication with the lower heat regenerator and the lower heat reboiler.

11. The method according to claim 10, wherein the absorption column is in fluid communication with the lower heat regenerator and the lower heat reboiler via a crossover heat exchanger.

12. The method according to any one of claims 1 to 11, wherein the solvent is a strengthening solvent, optionally comprising a tertiary amine, a sterically hindered amine, a polyamine, a salt, and water, and optionally the solvent is CDRMax.

13. Carbon dioxide (CO2) ２ A system for regenerating a solvent containing ), wherein the system is A single low-temperature and high-temperature combined regenerator, High-temperature regenerator and A single low-temperature and high-temperature combined regenerator, including a low-temperature regenerator, High-temperature reboilers and Including a low-temperature reboiler, The aforementioned high-temperature regenerator and the aforementioned high-temperature reboiler use carbon dioxide (CO2). ２ ) configured to regenerate lean solvents at temperatures above 120°C, The lower heat regenerator and the lower heat reboiler each independently reheat carbon dioxide (CO2) at a temperature in the range of 60°C to less than 120°C (or 100 to 119°C, or 100 to 115°C). ２ ) Configured to regenerate lean solvents, The aforementioned low-heat reboiler, the aforementioned high-heat reboiler, and the aforementioned low-heat and high-heat combined regenerator emit carbon dioxide (CO2) during use. ２ A system in which a solvent containing ) is fluidly communicated between each component.

14. The system according to claim 13, wherein the high-temperature regenerator operates at a temperature of 120°C to 140°C. Hmm.

15. The system according to claim 13 or 14, wherein the high-temperature reboiler operates at a temperature of 120°C to 140°C.

16. The aforementioned lower heat and higher heat combined regenerator and the lower heat reboiler utilize carbon dioxide (CO2). ２ A solvent containing ) is fluidly connected between the lower heat and higher heat combined regenerator and the lower heat reboiler; and / or, The aforementioned lower heat and higher heat combined regenerator and the aforementioned higher heat reboiler use carbon dioxide (CO2). ２ The system according to any one of claims 13 to 15, wherein a solvent containing ) is in fluid communication between the lower heat and higher heat combined regenerator and the higher heat reboiler.

17. The aforementioned system is CO ２ Rich solvent CO ２ Lean solvent, optional, with a carbon dioxide concentration of 2-3.3 mol / L －１ CO ２ A rich solvent of any choice, with a carbon dioxide concentration of 0.0 to 0.7 mol L. －１ Carbon dioxide (CO2) ２ The system according to any one of claims 13 to 16, configured to convert to a lean solvent.

18. The aforementioned system further, The system according to any one of claims 13 to 17, comprising 1, 2, 3, 4, 5, 6, 7, 8, 9, or 10 absorption columns, wherein the absorption columns are in fluid communication with the lower heat regenerator and the lower heat reboiler.

19. The system according to claim 18, wherein the absorption column is in fluid communication with a lower heat and higher heat combined regenerator, the lower heat reboiler, and the higher heat reboiler via a crossover heat exchanger.

20. The system according to any one of claims 13 to 19, further comprising a gas (optionally, an inert gas such as hydrogen or nitrogen) that does not dissolve in or react with the solvent, and the gas is present in the lower heat reboiler and / or lower heat regenerator to lower the temperature in the lower heat reboiler and / or lower heat regenerator, thereby allowing the use of lower heat alone or a combination of lower heat and higher heat.

21. The system according to any one of claims 13 to 20, further comprising a strengthening solvent, optionally a strengthening solvent comprising a tertiary amine, a sterically hindered amine, a polyamine, a salt, and water, wherein optionally the solvent is CDRMax.

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