A complexing agent and separation method for carbon isotope separation

Abstract

This disclosure presents a complexing agent and separation method for carbon isotope separation, belonging to the field of isotope generation technology. The complexing agent comprises a first component and a second component; wherein the first component is an organic amine; and the second component is a catalyst, wherein the catalyst is at least one selected from hydrochloric acid, sulfuric acid, and carboxylic acid. This disclosure, by combining the second component with the first component, utilizes the added catalyst to accelerate the reaction, bringing it closer to thermodynamic equilibrium, reducing the reaction potential energy, and accelerating the process. 13 C and 12 The isotope exchange reaction rate of C-amine complexes promotes the formation and decomposition equilibrium of amino acid esters through proton transfer, shortens the reaction time to reach equilibrium, increases abundance, and is applicable to low-temperature conditions, thus reducing energy consumption.

Description

Technical Field

[0001] This disclosure belongs to the field of isotope generation technology, specifically relating to a complexing agent, separation device, and separation method for carbon isotope separation. Background Technology

[0002] Carbon has two stable isotopes, namely carbon-12 (98.89%) and carbon-13 (1.1%). These carbon-12 and carbon-13 have wide industrial applications. For example, the 1.1% carbon-13 is concentrated to 99% carbon-13 for use as a tracer in chemistry, biochemistry, and the environment. Carbon-13-labeled compounds of urea and glucose are used for non-invasive diagnosis and metabolite studies of various diseases. For instance, the breath test, which diagnoses various diseases by measuring the carbon-13 content of exhaled breath after ingesting a carbon-13-labeled compound, has seen its application expand due to its diagnostic accuracy and convenience.

[0003] Currently, the main industrial production method for carbon isotopes is cryogenic distillation, which relies solely on a single-stage separation process. This method suffers from drawbacks such as low reaction efficiency, long processing time, and high energy consumption. Furthermore, the existing methods yield... 13 C isotopes and 12 The abundance of carbon isotopes is relatively low. Therefore, it is necessary to propose a new complexing agent to improve reaction efficiency, shorten reaction time, reduce energy consumption, and simultaneously increase the abundance of carbon isotopes. Summary of the Invention

[0004] This disclosure aims to at least address one of the technical problems existing in the prior art by providing a complexing agent and a separation method for carbon isotope separation.

[0005] In one aspect, this disclosure provides a complexing agent for carbon isotope separation, the complexing agent comprising a first component and a second component; wherein, The first component is an organic amine; The second component is a catalyst, which is at least one of hydrochloric acid, sulfuric acid, and carboxylic acid; the carboxylic acid has the general structural formula R1COOH or R2(COOH)2, wherein R1 is one of hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, isopentyl, and cyclopentyl, and R2 is one of methylene, ethylene, propylene, and methyl ethylene.

[0006] Optionally, the content of the catalyst is 0.5-5% of the organic amine content. For example, 0.5%, 1.0%, 1.5%, 2.0%, 2.5%, 3.0%, 3.5%, 4.0%, 4.5%, or 5.0%.

[0007] Optionally, the carboxylic acid is any one of acetic acid, malonic acid, and formic acid.

[0008] Optionally, the catalyst is one or more of hydrochloric acid, sulfuric acid, acetic acid, malonic acid, and formic acid.

[0009] Optionally, the organic amine is selected from compounds of Formula 1 below.

[0010] R1, R2, and R3 are each independently selected as hydrogen, C1-C8 alkyl, C3-C6 heteroaryl, C3-C8 cycloalkyl, C3-C8 aryl, or C3-C8 heterocyclic; the C1-C8 alkyl is optionally substituted with 1, 2, or 3 substituents selected from the following: C1-C3 alkyl, amino, methoxy, halogen, or hydroxyl; the C3-C8 cycloalkyl is optionally substituted with 1, 2, or 3 substituents selected from the following: C1-C3 alkyl, amino, methoxy, halogen, or hydroxyl; the C3-C8 heteroaryl is optionally substituted with 1, 2, or 3 substituents selected from the following: C1-C3 alkyl, amino, methoxy, halogen, or hydroxyl; the heteroatom in the heteroaryl or heterocyclic alkyl is selected from N.

[0011] Optionally, R1, R2, and R3 can be independently selected as hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, isopentyl, methoxymethyl, ethoxymethyl, methoxyethyl, ethoxyethyl, phenyl, benzyl, phenoxymethyl, phenoxyethyl, cyclopentyl, cyclohexyl, cyclopentylmethyl, hydroxymethyl, hydroxyethyl, hydroxypropyl, aminomethyl, aminoethyl, aminopropyl, fluoromethyl, fluoroethyl, chloromethyl, chloroethyl, bromomethyl, bromoethyl, difluoromethyl, trifluoromethyl, aryl, or heteroaryl.

[0012] Optionally, where R 1、 R 2、 R3 is independently selected from hydrogen or C1-C3 alkyl groups, wherein the C1-C3 alkyl groups are substituted with hydroxyl or methoxy groups, and R1, R 2、 R3 is not always hydrogen.

[0013] Optionally, R1 is hydrogen, R 2、 R3 is selected from hydrogen or C1-C3 alkyl, wherein the C1-C3 alkyl is substituted with hydroxyl or methoxy groups, and R 2、 R3 is not always hydrogen.

[0014] Optionally, the organic amine complexing agent includes primary amines, secondary amines, tertiary amines, or aromatic amines.

[0015] The primary amine refers to an organic amine formed by replacing one hydrogen atom in an ammonia (NH3) molecule with a hydrocarbon group, with the general formula R-NH2, such as methylamine, ethylamine, n-propylamine, n-butylamine, butanediamine, monoethanolamine, p-phenylenediamine, isobutanolamine, etc.

[0016] The secondary amine refers to an organic amine formed by replacing two hydrogen atoms in an ammonia molecule with a hydrocarbon group, with the general formula R2NH (the two hydrocarbon groups can be the same or different), such as dimethylamine, diethylamine, diethanolamine, diisobutylamine, diisopropanolamine, piperidine, pyrrolidine, etc. The secondary amines disclosed herein are preferably alkyl branched secondary amines and cyclic secondary amines.

[0017] The tertiary amine refers to an organic amine in which all three hydrogen atoms in the ammonia molecule are replaced by hydrocarbon groups, with the general formula R3N (the three hydrocarbon groups may be the same or different), and no hydrogen atom on the nitrogen atom. Examples include triethanolamine (TEA), N-methyldiethanolamine, trimethylamine, triethylamine, and N,N-dimethylaniline.

[0018] The aromatic amines refer to organic amines in which the amino group is directly attached to an aromatic ring (such as a benzene ring). Examples include N-methylaniline, N,N-dimethylaniline, aniline, and diphenylamine.

[0019] Optionally, the organic amine is at least one selected from diethanolamine, diethylamine, ethylene glycolamine, butanediamine, triethanolamine, N-methylaniline, p-phenylenediamine, piperidine, and pyrrolidine.

[0020] Optionally, the complexing agent further includes a viscosity modifier, which is any one of small molecule hydrocarbons, small molecule ethers, and small molecule ketones.

[0021] Optionally, the viscosity modifier content is 10-30% of the organic amine content. For example, 10%, 12%, 14%, 16%, 18%, 20%, 22%, 24%, 26%, 28%, or 30%.

[0022] Optionally, the small molecule hydrocarbon is selected from C5-C64. 10 Alkanes, C5-C 10 Cycloalkanes, C5-C 10 Aromatic hydrocarbons, C5-C 10 heteroaromatics or C5-C 10 Olefins; the C5-C 10 The alkane is optionally substituted with 1, 2, or 3 halogens; the C5-C 10 The cycloalkanes are optionally substituted with 1, 2, or 3 halogens; the C5-C 10 The aryl hydrocarbon is optionally substituted with one, two, or three halogens; the C5-C 10 The heteroaromatic hydrocarbons are optionally substituted with 1, 2 or 3 halogens or the C5-C... 10The olefin may optionally be substituted with one, two or three halogens; preferably, the halogens include one or more of fluorine, chlorine and bromine.

[0023] Optionally, the small molecule hydrocarbon is selected from 1-chloropentane, 1,2-dichloropentane, 1-chlorohexane, n-heptane, 1-chlorooctane, dichlorocyclohexane, and chlorocyclopentane.

[0024] Optionally, the small molecule ether is represented by the general formula R3OR4, wherein R3 and R4 are independently selected from C1-C1. 10 Alkyl, C3-C 10 cycloalkyl or C5-C 10 Aryl, the C1-C 10 The alkyl group may optionally be substituted with a C1-C3 alkyl group, wherein the C5-C 10 The aryl group may be optionally substituted with a C1-C3 alkyl group; the C3-C 10 The cycloalkyl group may be optionally substituted with a C1-C3 alkyl group.

[0025] Optionally, R3 and R4 are independently selected from one of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, isopentyl, cyclopentyl, n-hexyl, isohexyl, cyclohexyl, phenyl, and benzyl. Optionally, the small molecule ether is selected from diisopropyl ether, methyl tert-butyl ether, ethyl tert-butyl ether, or di-n-propyl ether.

[0026] Optionally, the small molecule ketone is represented by the general formula R5(C=O)R6, wherein R5 and R6 are independently selected from C1-C6. 10 Alkyl, C3-C 10 cycloalkyl, C5-C 10 Aryl groups or R5, R6 form cyclic ketones with C=O, wherein the C1-C 10 The alkyl group may optionally be substituted with a C1-C3 alkyl group, wherein the C5-C 10 The aryl group may be optionally substituted with a C1-C3 alkyl group, wherein the C3-C 10 The cycloalkyl group may optionally be substituted with a C1-C3 alkyl group; the cycloketone may optionally be substituted with a C1-C3 alkyl group.

[0027] Optionally, R5 and R6 are independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, isopentyl, cyclopentyl, n-hexyl, isohexyl, cyclohexyl, phenyl, benzyl, or R5 and R6 form a C4-C8 cyclic ketone with C=O.

[0028] Optionally, the small molecule ketone is selected from one of cyclopentanone, cyclohexanone, methylcyclopentanone, methylcyclohexanone, methyl isobutyl ketone, etc.

[0029] In another aspect of this disclosure, a method for separating carbon isotopes is proposed, the method comprising: Carbon dioxide and a complexing agent are introduced into a complexing tower, wherein the molar ratio of carbon dioxide to complexing agent is (0.20~0.80):1. The carbon dioxide is then introduced at 25-35℃. 12 CO2 complexes with organic amines to form... 12 C-amine complex; the complexing agent is the complexing agent described above; The 12 The C-amine complex flows into an exchange tower, and carbon dioxide gas is introduced into the exchange tower. At 10-60°C, the carbon dioxide... 13 CO2 and the above 12 The C-amine complex undergoes an exchange reaction to generate 12 CO2 and 13 C-amine complex; The 13 The C-amine complex is decomposed in a cracking tower at a temperature of 100-250℃ into cracking products and... 13 CO2; The pyrolysis products form organic amines and impurities in the impurity removal tower.

[0030] Optionally, the molar ratio of the carbon dioxide and the organic amine complexing agent is (0.20~0.80):1; for example, 0.2:1, 0.3:1, 0.4:1, 0.5:1, 0.6:1, 0.7:1, 0.8:1; preferably, the molar ratio is (0.3~0.6):1.

[0031] Optionally, the temperature of the complexing tower is 25-35℃; it can be selected from 25℃, 26℃, 27℃, 28℃, 29℃, 30℃, 31℃, 32℃, 33℃, 34℃ or 35℃.

[0032] Optionally, the temperature of the exchange tower is 10-60℃; it can be selected from 10℃, 12℃, 14℃, 16℃, 18℃, 20℃, 22℃, 24℃, 26℃, 28℃, 30℃, 32℃, 34℃, 36℃, 38℃, 40℃, 42℃, 44℃, 46℃, 48℃, 50℃, 52℃, 54℃, 56℃, 58℃ or 60℃.

[0033] Optionally, the heating and pyrolysis temperature of the pyrolysis tower is 100-250℃; it can be selected from 100℃, 110℃, 120℃, 130℃, 140℃, 150℃, 160℃, 170℃, 180℃, 190℃, 200℃, 210℃, 220℃, 230℃, 240℃ or 250℃.

[0034] In another aspect, this disclosure provides a 13 The C isotope is prepared by the aforementioned separation method. 13C isotope abundance is above 99.00%.

[0035] This disclosure presents a complexing agent, a separation device, and a separation method for carbon isotopes.

[0036] The complexing agent comprises a first component and a second component; wherein the first component is an organic amine; and the second component is a catalyst, wherein the catalyst is at least one selected from hydrochloric acid, sulfuric acid, and carboxylic acid. This disclosure, by combining the second component with the first component, utilizes the added catalyst to accelerate the reaction, bringing it closer to thermodynamic equilibrium, reducing the reaction potential energy, and thus accelerating the reaction. 13 CO2 and 12 The isotope exchange reaction rate of C-amine complexes promotes the formation and decomposition equilibrium of carbamates through proton transfer, shortens the reaction time to reach equilibrium, increases abundance, and makes them suitable for low-temperature conditions, thus reducing energy consumption. Attached Figure Description

[0037] Figure 1 This is a schematic diagram of a carbon isotope separation device according to a specific embodiment of this disclosure; Figure 2 This is a flowchart illustrating a carbon isotope separation method according to a specific embodiment of this disclosure. Detailed Implementation

[0038] To enable those skilled in the art to better understand the technical solutions of this disclosure, the disclosure will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are only used to explain this disclosure and represent a part of the embodiments of this disclosure, not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this disclosure without creative effort are within the protection scope of this disclosure.

[0039] In one aspect of this disclosure, a complexing agent for carbon isotope separation is provided, the complexing agent comprising a first component and a second component; wherein the first component is an organic amine; and the second component is a catalyst, said catalyst being at least one of hydrochloric acid, sulfuric acid, and carboxylic acid.

[0040] It should be understood that when organic amines are used alone, the isotope exchange efficiency is low, and the time to reach equilibrium is relatively long. Therefore, in this embodiment, by combining the second component with the first component, the added catalyst can catalyze and accelerate the reaction, bringing it closer to thermodynamic equilibrium, reducing the reaction potential energy, and thus accelerating the reaction. 13 C and 12 The isotope exchange reaction rate of C-amine complexes promotes the formation and decomposition equilibrium of carbamates through proton transfer, shortens the time to reach equilibrium, increases abundance, and is suitable for low-temperature conditions, thus reducing energy consumption.

[0041] In some preferred embodiments, the catalyst may preferably be a carboxylic acid, such as acetic acid, malonic acid, or formic acid. These carboxylic acids are weakly acidic, which helps prevent excessive formation of amine salts, and they are volatile, making them easy to separate and regenerate from the amine. The carboxylic acid releases H₂ in the amine solution. + H + and 12 O of C-amine complex - This combination forms an unstable protonation intermediate, lowering the activation energy of the decomposition reaction. The protonation intermediate is easily decomposed into... 12 CO2 and free amines; the released free amines can rapidly react with CO2 in the gas phase. 13 CO2 re-complexes, thereby increasing the reaction rate. At the same time, the carboxylic acid maintains a stable free amine concentration through a "proton buffer," ensuring that isotope exchange continues and shortening the reaction half-life.

[0042] In some other preferred embodiments, the catalyst content is 0.5-5% of the organic amine content, for example, 1-3% is preferred. If the content is too low, the catalytic effect is not obvious, and if the content is too high, the free amine concentration will be excessively reduced, which will inhibit the complexation reaction.

[0043] In some other preferred embodiments, the organic amine is at least one of primary amine, secondary amine, tertiary amine, and aromatic amine. For example, the secondary amine is an alkyl branched secondary amine, such as N-methylaniline; the primary amine is monoethanolamine; the tertiary amine is triethanolamine; and the aromatic amine is N,N-dimethylaniline.

[0044] As a further preferred option, the amine organic compound is at least one of diethanolamine, butanediamine, triethanolamine, N-methylaniline, p-phenylenediamine, and cyclic secondary amines.

[0045] Furthermore, the complexing agent of this embodiment also includes a third component, which is a viscosity modifier. The content of the viscosity modifier is 10-30% of the organic amine content. The viscosity modifier can preferably be any one of small molecule hydrocarbons, small molecule ethers, and small molecule ketones.

[0046] Viscosity modifiers can disrupt the hydrogen bonds between amine molecules. Furthermore, as small organic molecules, they insert themselves into the intermolecule gaps of amine molecules through a molecular dilution effect, physically separating the molecules and further reducing the viscosity of the organic amine solution. This increases the diffusion rate of the ¹³C-amine complex in the liquid phase during the exchange reaction, shortens the isotope exchange time, and reduces energy consumption. In other words, this viscosity modifier works synergistically with low-boiling-point solvents to further reduce the viscosity of organic amines, improve gas-liquid mass transfer efficiency, and reduce energy consumption.

[0047] It should be noted that the above viscosity modifier can be added simultaneously with the low-boiling-point solvent during the complexation stage, or it can be added separately during the exchange reaction stage; there are no specific limitations on this.

[0048] In some preferred embodiments, the small molecule hydrocarbon is preferably C5-C. 10 Halogenated hydrocarbons, such as chloroalkanes, including 1-chloropentane, 1,2-dichloropentane, 1-chlorohexane, n-heptane, 1-chlorooctane, etc.; and halogenated cycloalkanes, including chlorocycloalkanes, dichlorocyclohexane, chlorocyclopentane, etc.

[0049] In some other preferred embodiments, the small molecule ether may preferably be C5-C. 10 Ethers, such as diisopropyl ether, methyl tert-butyl ether, ethyl tert-butyl ether, di-n-propyl ether, etc., and of course, other ethers can be selected, without specific limitations.

[0050] In some other preferred embodiments, the small molecule ketone may preferably be C5-C. 10 Ketones, such as cyclohexanone, methyl isobutyl ketone, cyclopentanone, n-heptanone, etc.

[0051] In this embodiment, the viscosity modifier and the catalyst work synergistically in mass transfer and reaction. Based on mass transfer, the catalyst accelerates the reaction through proton transfer. 12 C-amine complex decomposition and 13 CO2 complexation, and the synergy between the two, enhances the "mass transfer-reaction matching degree" of isotope exchange.

[0052] like Figure 1 As shown, in another aspect of this disclosure, a carbon isotope separation device 100 is provided. The separation device includes: a complexing tower 110, an exchange tower 120, a cracking tower 130, and a purification tower 140 connected in sequence; wherein, the bottom of the complexing tower 110 is provided with a first gas inlet for introducing carbon dioxide and a gas outlet for discharging carbon dioxide. 12 The first outlet of the C-amine complex has a first inlet at the top. The complexing agent here is the complexing agent described above, which includes a first component and a second component. The first component is an organic amine, and the second component is a catalyst, which is at least one of hydrochloric acid, sulfuric acid, and carboxylic acid. In this complexing tower 110, carbon dioxide... 12 CO2 complexes with organic amines to form... 12 C-amine complex; the bottom of the exchange tower 120 is provided with a second gas inlet for introducing carbon dioxide gas and a outlet for discharging gas. 13 The second outlet of the C-amine complex has a second inlet connected to the first outlet at its top and a discharge port for discharging. 12 The first gas outlet for CO2, thus... 12 The C-amine complex enters the exchange tower 120 through the first outlet and the second inlet. In the exchange tower 120, the carbon dioxide introduced... 13 CO2 and 12 The C-amine complex undergoes an exchange reaction to generate 12 CO2 and13 C-amine complex, 12 CO2 is discharged through the first gas outlet. 13 The C-amine complex is discharged into the cracking tower through the second outlet. The cracking tower 130 has a third outlet at the bottom for discharging the cracking products, and a third inlet connected to the second outlet at the top, as well as a discharge outlet. 13 The second gas outlet for CO2, thus... 13 The C-amine complex enters the cracking tower 130 through the second outlet and the third inlet. 13 C-amine complexes undergo thermal pyrolysis to produce pyrolysis products and 13 CO2, 13 CO2 is discharged through the second gas outlet, and the pyrolysis products are discharged through the third outlet to the impurity removal tower. The bottom of the impurity removal tower 140 is provided with a fourth inlet connected to the third outlet, and the top of the tower is provided with a fourth outlet for discharging organic amines. In the impurity removal tower 140, the pyrolysis products form organic amines and impurities, wherein the impurities remain at the bottom of the tower, and the organic amines are discharged through the fourth outlet.

[0053] It should be noted that the organic amine in the complexing agent is added through the first inlet, while the second component in the complexing agent can be directly mixed with the first component (organic amine) and added to the complexing tower through the first inlet to accelerate the process. 12 CO2 complexes with organic amines to form... 12 The reaction rate of the "C-amine complex" can also be accelerated by adding the second component through other feed ports of the exchange tower. 13 The rate at which CO2 complexes with amines to form ¹³C-amine complexes means that the second component can be added before the exchange reaction, and there is no specific restriction on the order of addition.

[0054] It should be understood that when the catalyst is added separately in the exchange tower, additional feed ports for adding the catalyst should be added to the exchange tower.

[0055] It should be further noted that the complexing agent in this embodiment may also include a viscosity modifier, which is any one of small molecule hydrocarbons, small molecule ethers, and small molecule ketones. This viscosity modifier can be added during the complexation reaction stage or the exchange reaction stage to reduce the viscosity of the amine solution and improve mass transfer efficiency. Similarly, when the viscosity modifier is added during the exchange stage, an inlet for the viscosity modifier should be added to the exchange tower. Of course, for the exchange tower, the inlet for adding the catalyst and the inlet for adding the viscosity modifier can be set separately or they can be the same; there is no specific limitation on this.

[0056] It should be noted that this embodiment does not specifically limit the complexing tower, exchange tower, pyrolysis tower and impurity removal tower included in the device. They can be selected according to actual needs. For details, please refer to the following description.

[0057] Specifically, since carbon dioxide gas participates in the complexation reaction, its weak chemical bonds can generally proceed in two steps when reacting with organic amines. That is, the complexation tower can include a pre-synthesis tower and a synthesis tower. The pre-synthesis tower can be an atmospheric pressure tower, and the synthesis tower can be an atmospheric pressure tower or a pressurized tower. In the pre-synthesis tower, under low temperature and high amine concentration conditions, ¹²C is rapidly captured to generate an intermediate. In the synthesis tower, under gas-liquid countercurrent conditions, the activated amine liquid reacts countercurrently with CO2 in the packed tower. The catalytic effect of the gas phase chemicals is used to increase the complexation reaction rate and convert it into a stable complex.

[0058] In some preferred embodiments, the temperature of the complexing tower is set to 25-35°C, at which the forward reaction is promoted and the reverse reaction (complex decomposition) is suppressed, thereby improving the ¹²C separation efficiency.

[0059] In this embodiment, by using organic amines to selectively adsorb carbon dioxide in the complexation tower, low-purity carbon dioxide feedstock can be directly processed. Combined with subsequent exchange and pyrolysis processes, the abundance of carbon isotopes can be effectively increased, thus broadening the sources of raw materials for carbon isotope separation.

[0060] Furthermore, the exchange tower can be a packed tower or a plate tower. For example, when using a packed tower, the gas-liquid contact area is 2–3 times that of a plate tower due to the highly efficient and well-structured packing, which can significantly improve the isotope exchange efficiency. ¹²C-amine complexes are sprayed from the top distributor, forming a continuous liquid film on the packing surface. CO2 gas containing ¹³C enters from the bottom of the tower, flows upward through the gaps in the packing, and comes into countercurrent contact with the liquid film. At the gas-liquid interface, the ¹³C in CO2 undergoes a reversible exchange reaction with the ¹²C-amine complex in the liquid film. For example, ¹³CO2 (gas phase) + ¹²C-amine complex (liquid phase). The reaction is ¹²CO₂ (gas phase) + ¹³C-amine complex (liquid phase). The ¹³C-amine complex is more stable than the ¹²C-amine complex, shifting the equilibrium towards the formation of the ¹³C-amine complex. The large contact area provided by the packing material allows the exchange reaction to proceed fully. Furthermore, based on the second component, the reaction rate can be significantly increased, shortening the time it takes for the isotopes to reach equilibrium.

[0061] In some preferred embodiments, the temperature of the exchange tower is set to 40-60°C, at which temperature the isotope exchange equilibrium constant K is optimized to achieve the desired effect. 13 C migrates into the liquid phase.

[0062] The packed tower in this embodiment provides an efficient mass transfer environment for isotope exchange of ¹³C and ¹²C-amine complexes through the synergistic effect of high specific surface area packing, gas-liquid countercurrent, and fine distribution. Its low pressure drop characteristics reduce gas transport and circulation energy consumption, resulting in high mass transfer efficiency.

[0063] Furthermore, the pyrolysis tower can be a plate tower, in which the liquid phase is violently agitated by rising air bubbles on the plates. 13 The C-amine complex undergoes reversible decomposition at high temperature, generating a regenerated amine liquid phase and 13 In the CO2 gas phase, ¹³CO2 in the bubbles flows upward and enters the separation section. The regenerated amine flows downward along the downcomer, collects in the bottom of the tower, and is pumped to the impurity removal tower for purification and recycling.

[0064] In some preferred embodiments, 13 C-amine complexes decompose upon heating into organic amines and 13 The thermal decomposition temperature of CO2 is 100-250℃. High temperatures promote the reverse reaction, resulting in the targeted release of high-purity CO2. 13 CO2, avoid 13 C loss.

[0065] Furthermore, impurity removal can be achieved using vacuum distillation columns or azeotropic distillation columns.

[0066] For example, when the impurity removal tower is a vacuum distillation tower, the cracking products are converted into organic amines and impurities by vacuum distillation. This method mainly utilizes the difference in boiling points of each component to achieve separation. Under vacuum conditions, organic amines have a higher boiling point and do not decompose, but still exist in molecular form. They are collected as high-boiling-point components from the fourth outlet of the vacuum distillation tower. Other by-products, such as amine polymers generated by the oxidation, condensation or cross-linking reaction of organic amines, undergo partial depolymerization under vacuum distillation conditions or remain at the bottom of the tower.

[0067] For example, when the impurity removal tower is an azeotropic distillation tower, the cracking products are azeotropically distilled to form organic amines and impurities. Most organic amines form the lowest azeotrope with water, and after condensation and separation, an aqueous phase and an amine phase are obtained. The amine phase is discharged through the fourth outlet, while some other oligomeric impurities have larger molecular weights and boiling points higher than pure amines, do not participate in the azeotrope, and remain at the bottom of the tower.

[0068] It should also be understood that the fourth outlet of the impurity removal tower can be connected to the first inlet to allow the recovered organic amines to participate in further reactions, be recycled, and reduce costs.

[0069] As shown in Figure 2, another aspect of this disclosure provides a method S200 for separating carbon isotopes, specifically including the following steps S210~S240: S210. Carbon dioxide and a complexing agent are introduced into the complexing tower. The complexing agent here is the complexing agent described above, which includes a first component and a second component. The first component is an organic amine, and the second component is a catalyst. The catalyst is at least one of hydrochloric acid, sulfuric acid, and carboxylic acid. Thus, under the action of the catalyst... 12 The CO2 complexation reaction rate is higher than 13 CO2 is rapid, which promotes the release of carbon dioxide. 12 C complexes with organic amines to form 12 C-amine complexes, for example, organic amines using primary amines, react as follows: 12 CO2 + RNH2 RNH 12 COOH ( 12 C-amine complex).

[0070] The temperature of the complexation tower in step S210 is set to 25-35℃. At this temperature, the forward reaction is promoted, the reverse reaction is inhibited, the decomposition of the complex is avoided, and the ¹²C separation efficiency is improved.

[0071] It should be noted that the second component in the complexing agent in this embodiment can be added in step S110 to mix with the organic amine and then added in the complexing tower, or the second component can be added in the exchange tower in step S220. That is to say, the second component can be added before the exchange reaction, and there is no specific limitation on the order of addition.

[0072] It should also be noted that the complexing agent in this embodiment may also include a viscosity modifier, wherein the viscosity modifier is any one of small molecule hydrocarbons, small molecule ethers, and small molecule ketones, and may be added during the complexation reaction stage or the exchange reaction stage, in order to reduce the viscosity of the amine solution and improve the mass transfer efficiency.

[0073] It should be understood that the viscosity modifier described above can also be added in step S110 to mix with the organic amine and add it in the complexation tower, or the above components can be added in the exchange tower in step S220.

[0074] S220, 12 The C-amine complex flows into an exchange column, and carbon dioxide gas is introduced into the exchange column, thus allowing the complex to react with catalyst H. + Under its influence, the decomposition rate increases, promoting the exchange of carbon dioxide in the exchange tower. 13 C and 12 The C-amine complex undergoes an exchange reaction to generate 12 CO2 and 13 C-amine complex, generated 12 CO2 is directly discharged from the exchange tower and collected. 13The C-amine complex further flows into the cracking tower, and the reaction process is as follows: 13 CO2+RNH 12 COOH ( 12 C-amine complex) 12 CO2+ RNH 13 COOH ( 13 C-amine complex).

[0075] In step S220, the temperature of the exchange tower is set to 40-60℃. At this temperature, the isotope exchange equilibrium constant K is optimized to achieve the desired effect. 13 C migrates into the liquid phase.

[0076] S230, 13 C-amine complexes are pyrolyzed by heating in a pyrolysis tower into pyrolysis products and... 13 CO2, at this time 13 CO2 is directly discharged from the cracking tower and collected to separate carbon isotopes, while the cracking products further flow into the impurity removal tower. The reaction process is as follows: RNH 13 COOH ( 13 C-amine complex) RNH2+ 13 CO2.

[0077] The heating and pyrolysis temperature of the S230 pyrolysis tower is 80-150℃. High temperature promotes the reverse reaction and directionally releases high-purity [product / material]. 13 CO2, avoid 13 C loss.

[0078] S240, the cracking products form organic amines and impurities in the impurity removal tower.

[0079] It should be noted that in step S240, the pyrolysis products can be purified by vacuum distillation or azeotropic distillation, and there is no specific limitation on which method is used.

[0080] For example, the cracking products are distilled under reduced pressure to form organic amines and impurities. Under these conditions, the impurity removal column is a reduced pressure distillation column. This method mainly utilizes the difference in boiling points of the components to achieve separation. Under reduced pressure, the organic amines have higher boiling points and do not decompose, but still exist in molecular form. They are collected as high-boiling-point components from the fourth outlet of the reduced pressure distillation column. Other by-products, such as amine polymers generated by the oxidation, condensation or cross-linking reactions of organic amines, undergo partial depolymerization under reduced pressure distillation conditions or remain at the bottom of the column.

[0081] For example, the cracking products are azeotropically distilled to form organic amines and impurities. Under these conditions, the impurity removal tower is an azeotropic distillation tower. Most organic amines form the lowest azeotrope with water. After condensation and separation, an aqueous phase and an amine phase are obtained. The amine phase is discharged through the fourth outlet, while some other oligomeric impurities have larger molecular weights and boiling points higher than pure amines. They do not participate in the azeotrope and remain at the bottom of the tower.

[0082] The separation method disclosed herein is simple. It is based on adding a second component to the exchange reaction, which lowers the reaction energy barrier, increases the reaction rate, promotes isotope exchange, shortens the reaction time, and simultaneously increases the carbon isotope abundance.

[0083] The carbon dioxide gas introduced into the complexation tower and exchange tower of this disclosure has a natural abundance of approximately 1.1%¹³C. 12 C is approximately 98.89%.

[0084] The method for separating carbon isotopes will be further explained below with reference to specific embodiments: Example 1 This example illustrates a method for separating carbon isotopes, with the following reaction process: 12 CO2 + R2NH R2NH + 12 COO - 13 CO2 + R2NH + 12 COO - 12 CO2 + R2NH +13 COO - R2NH +13 COO - R2NH+ 13 CO2.

[0085] Where R=(HOCH2CH2)2- The specific methods include the following: This example demonstrates a method for separating carbon isotopes, the specific process of which is as follows: S1. Carbon dioxide and a complexing agent are introduced into the complexing tower. The complexing agent comprises a first component, a second component, and a third component. The first component is diethanolamine, the second component is formic acid, and the third component is chlorobutane. The content of the second component is 3% of the content of the first component, and the content of the third component is 20% of the content of the first component. The molar ratio of carbon dioxide to diethanolamine is 0.35:1. At 30°C, the carbon dioxide... 12 CO2 complexes with the complexing agent organic amine to form... 12 C-amine complex, at this time 12The C-amine complex flows into the exchange tower.

[0086] S2, 12 The C-amine complex flows into the exchange column, and carbon dioxide gas is introduced into the exchange column. At 35°C, the carbon dioxide... 13 CO2 and 12 The C-amine complex undergoes an exchange reaction to generate 12 CO2 and 13 C-amine complex, at this time 12 CO2 is discharged from the exchange tower. 13 The C-amine complex further flows into the cracking tower.

[0087] S3 13 The C-amine complex was decomposed in a cracking tower at 105°C into cracking products and... 13 CO2.

[0088] S4. The pyrolysis products form organic amines and impurities in the impurity removal tower.

[0089] Specifically, under reduced pressure, the organic amine complexing agent, which has a high boiling point, does not decompose and remains in molecular form. It is collected as a high-boiling-point component from the fourth outlet of the reduced pressure distillation column. Other by-products, such as amine polymers produced by the oxidation, condensation, or cross-linking reactions of organic amines, catalysts, and viscosity modifiers, undergo partial depolymerization under reduced pressure distillation conditions or remain at the bottom of the column.

[0090] Detection method: Inductively coupled plasma mass spectrometry (ICP-MS) for isotopic abundance determination. After analysis and testing 12 The abundance of CO2 was 0.26%. 13 The abundance of CO2 was 99.74%.

[0091] Example 2 S1. Carbon dioxide and a complexing agent are introduced into the complexing tower. The complexing agent comprises a first component, a second component, and a third component. The first component is diethanolamine, the second component is malonic acid, and the third component is chlorobutane. The content of the second component is 3% of the content of the first component, and the content of the third component is 20% of the content of the first component. The molar ratio of carbon dioxide to diethanolamine is 0.25:1. At 25°C, the carbon dioxide... 12 CO2 complexes with the complexing agent organic amine to form... 12 C-amine complex, at this time 12 The C-amine complex flows into the exchange tower.

[0092] S2, 12 The C-amine complex flows into the exchange column, and carbon dioxide gas is introduced into the exchange column. At 40°C, the carbon dioxide... 13 CO2 and12 The C-amine complex undergoes an exchange reaction to generate 12 CO2 and 13 C-amine complex, at this time 12 CO2 is discharged from the exchange tower. 13 The C-amine complex further flows into the cracking tower.

[0093] S3 13 The C-amine complex was decomposed in a cracking tower at 120°C into cracking products and... 13 CO2.

[0094] S4. The pyrolysis products form organic amines and impurities in the impurity removal tower.

[0095] Specifically, under reduced pressure, the organic amine complexing agent, which has a high boiling point, does not decompose and remains in molecular form. It is collected as a high-boiling-point component from the fourth outlet of the reduced pressure distillation column. Other by-products, such as amine polymers produced by the oxidation, condensation, or cross-linking reactions of organic amines, catalysts, and viscosity modifiers, undergo partial depolymerization under reduced pressure distillation conditions or remain at the bottom of the column.

[0096] Detection method: Inductively coupled plasma mass spectrometry (ICP-MS) for isotopic abundance determination. After analysis and testing 12 The abundance of CO2 was 0.27%. 13 The abundance of CO2 was 99.73%.

[0097] Example 3 S1. Carbon dioxide and a complexing agent are introduced into the complexing tower. The complexing agent comprises a first component, a second component, and a third component. The first component is diethanolamine, the second component is formic acid, and the third component is diisopropyl ether. The content of the second component is 3% of the content of the first component, and the content of the third component is 20% of the content of the first component. The molar ratio of carbon dioxide to diethanolamine is 0.5:1. At 27°C, the carbon dioxide... 12 CO2 complexes with the complexing agent organic amine to form... 12 C-amine complex, at this time 12 The C-amine complex flows into the exchange tower.

[0098] S2, 12 The C-amine complex flows into the exchange column, and carbon dioxide gas is introduced into the exchange column. At 27°C, the carbon dioxide... 13 CO2 and 12 The C-amine complex undergoes an exchange reaction to generate 12 CO2 and 13 C-amine complex, at this time 12 CO2 is discharged from the exchange tower. 13 The C-amine complex further flows into the cracking tower.

[0099] S3 13 The C-amine complex was decomposed in a cracking tower at 140°C into cracking products and... 13 CO2.

[0100] S4. The pyrolysis products form organic amines and impurities in the impurity removal tower.

[0101] Specifically, under reduced pressure, the organic amine complexing agent, which has a high boiling point, does not decompose and remains in molecular form. It is collected as a high-boiling-point component from the fourth outlet of the reduced pressure distillation column. Other by-products, such as amine polymers, catalysts, and viscosity modifiers produced by the oxidation, condensation, or cross-linking reactions of organic amines, undergo partial depolymerization under reduced pressure distillation conditions or remain at the bottom of the column.

[0102] Detection method: Inductively coupled plasma mass spectrometry (ICP-MS) for isotopic abundance determination. After analysis and testing 12 CO2 abundance was 0.29%. ， 13 The abundance of CO2 was 99.71%.

[0103] Example 4 S1. Carbon dioxide and a complexing agent are introduced into the complexing tower. The complexing agent comprises a first component, a second component, and a third component. The first component is diethanolamine, the second component is formic acid, and the third component is n-heptanone. The content of the second component is 3% of the content of the first component, and the content of the third component is 20% of the content of the first component. The molar ratio of carbon dioxide to diethanolamine is 0.5:1. At 35°C, the carbon dioxide... 12 CO2 complexes with the complexing agent organic amine to form... 12 C-amine complex, at this time 12 The C-amine complex flows into the exchange tower.

[0104] S2, 12 The C-amine complex flows into the exchange column, and carbon dioxide gas is introduced into the exchange column. At 35°C, the carbon dioxide... 13 CO2 and 12 The C-amine complex undergoes an exchange reaction to generate 12 CO2 and 13 C-amine complex, at this time 12 CO2 is discharged from the exchange tower. 13 The C-amine complex further flows into the cracking tower.

[0105] S3 13 The C-amine complex was decomposed in a cracking column at 180°C into cracking products and... 13 CO2.

[0106] S4. The pyrolysis products form organic amines and impurities in the impurity removal tower.

[0107] Specifically, under reduced pressure, the organic amine complexing agent, which has a high boiling point, does not decompose and remains in molecular form. It is collected as a high-boiling-point component from the fourth outlet of the reduced pressure distillation column. Other by-products, such as amine polymers, catalysts, and viscosity modifiers produced by the oxidation, condensation, or cross-linking reactions of organic amines, undergo partial depolymerization under reduced pressure distillation conditions or remain at the bottom of the column.

[0108] Detection method: Inductively coupled plasma mass spectrometry (ICP-MS) for isotopic abundance determination. After analysis and testing 12 The abundance of CO2 was 0.36%. 13 The abundance of CO2 was 99.64%.

[0109] Example 5 This example illustrates a method for separating carbon isotopes, with the following reaction process: 12 CO2 + RNH2 RNH2 + 12 COO - 13 CO2 + RNH2 + 12 COO - 12 CO2 + RNH2 + 13 COO - RNH2 +13 COO - RNH2+ 13 CO2.

[0110] R=HO-CH2-CH2- The specific methods include the following: S1. Carbon dioxide and a complexing agent are introduced into the complexing tower. The complexing agent comprises a first component, a second component, and a third component. The first component is ethylene glycolamine, the second component is formic acid, and the third component is ethyl tert-butyl ether. The content of the second component is 3% of the content of the first component, and the content of the third component is 20% of the content of the first component. The molar ratio of carbon dioxide to diethanolamine is 0.6:1. At 32°C, the carbon dioxide... 12 CO2 complexes with the complexing agent organic amine to form... 12 C-amine complex, at this time 12 The C-amine complex flows into the exchange tower.

[0111] S2, 12The C-amine complex flows into the exchange column, and carbon dioxide gas is introduced into the exchange column. At 55°C, the carbon dioxide... 13 CO2 and 12 The C-amine complex undergoes an exchange reaction to generate 12 CO2 and 13 C-amine complex, at this time 12 CO2 is discharged from the exchange tower. 13 The C-amine complex further flows into the cracking tower.

[0112] S3 13 The C-amine complex was decomposed in a cracking column at 160°C into cracking products and... 13 CO2.

[0113] S4. The pyrolysis products form organic amines and impurities in the impurity removal tower.

[0114] Specifically, under reduced pressure, the organic amine complexing agent, which has a high boiling point, does not decompose and remains in molecular form. It is collected as a high-boiling-point component from the fourth outlet of the reduced pressure distillation column. Other by-products, such as amine polymers, catalysts, and viscosity modifiers produced by the oxidation, condensation, or cross-linking reactions of organic amines, undergo partial depolymerization under reduced pressure distillation conditions or remain at the bottom of the column.

[0115] Detection method: Inductively coupled plasma mass spectrometry (ICP-MS) for isotopic abundance determination. After analysis and testing 12 CO2 abundance was 0.24%. ， 13 The abundance of CO2 was 99.76%.

[0116] Example 6 This example illustrates a method for separating carbon isotopes, with the following reaction: 12 CO2 + H2O + R3N R3NH + H¹²CO3 - 13 CO2 + R3NH + H¹²CO3 - 12 CO2+ R3NH + H 13 CO3 -

[0117] R3NH + H 13 CO3 - R3N+ 13 CO2 + H2O Where R=(HOCH2CH2)3- S1. Carbon dioxide and a complexing agent are introduced into the complexing tower. The complexing agent comprises a first component, a second component, and a third component. The first component is triethanolamine, the second component is acetic acid, and the third component is cyclohexanone. The content of cyclohexanone is 20% of the organic amine, and the content of acetic acid is 3% of the organic amine. The molar ratio of carbon dioxide to diethanolamine is 0.7:1. At 30°C, the carbon dioxide... 12 CO2 complexes with the complexing agent organic amine to form... 12 C-amine complex, at this time 12 The C-amine complex flows into the exchange tower.

[0118] S2, 12 The C-amine complex flows into the exchange column, and carbon dioxide gas is introduced into the exchange column. At 50°C, the carbon dioxide... 13 CO2 and 12 The C-amine complex undergoes an exchange reaction to generate 12 CO2 and 13 C-amine complex, at this time 12 CO2 is discharged from the exchange tower. 13 The C-amine complex further flows into the cracking tower.

[0119] S3 13 The C-amine complex was decomposed in a cracking tower at 200°C into cracking products and... 13 CO2.

[0120] S4. The pyrolysis products form organic amines and impurities in the impurity removal tower.

[0121] Specifically, under reduced pressure, the organic amine complexing agent, which has a high boiling point, does not decompose and remains in molecular form. It is collected as a high-boiling-point component from the fourth outlet of the reduced pressure distillation column. Other by-products, such as amine polymers, catalysts, and viscosity modifiers produced by the oxidation, condensation, or cross-linking reactions of organic amines, undergo partial depolymerization under reduced pressure distillation conditions or remain at the bottom of the column.

[0122] Detection method: Inductively coupled plasma mass spectrometry (ICP-MS) for isotopic abundance determination. After analysis and testing 12 The abundance of CO2 was 0.34%. 13 The abundance of CO2 was 99.66%.

[0123] Example 7 S1. Carbon dioxide and a complexing agent are introduced into the complexing tower. The complexing agent comprises a first component, a second component, and a third component. The first component is N-methylaniline, the second component is sulfuric acid, and the third component is dichlorocyclohexane. The content of dichlorocyclohexane is 20% of the organic amine, and the content of sulfuric acid is 3% of the organic amine. The molar ratio of carbon dioxide to organic amine is 0.4:1. At 30°C, the carbon dioxide... 12 CO2 complexes with the complexing agent organic amine to form... 12 C-amine complex, at this time 12 The C-amine complex flows into the exchange tower.

[0124] S2, 12 The C-amine complex flows into the exchange column, and carbon dioxide gas is introduced into the exchange column. At 40°C, the carbon dioxide... 13 CO2 and 12 The C-amine complex undergoes an exchange reaction to generate 12 CO2 and 13 C-amine complex, at this time 12 CO2 is discharged from the exchange tower. 13 The C-amine complex further flows into the cracking tower.

[0125] S3 13 The C-amine complex was decomposed in a cracking column at 180°C into cracking products and... 13 CO2.

[0126] S4. The pyrolysis products form organic amines and impurities in the impurity removal tower.

[0127] Specifically, under reduced pressure, the organic amine complexing agent, which has a high boiling point, does not decompose and remains in molecular form. It is collected as a high-boiling-point component from the fourth outlet of the reduced pressure distillation column. Other by-products, such as amine polymers, catalysts, and viscosity modifiers produced by the oxidation, condensation, or cross-linking reactions of organic amines, undergo partial depolymerization under reduced pressure distillation conditions or remain at the bottom of the column.

[0128] Detection method: Inductively coupled plasma mass spectrometry (ICP-MS) for isotopic abundance determination. After analysis and testing 12 The abundance of CO2 was 0.19%. 13 The abundance of CO2 was 99.81%.

[0129] Experimental Example 1: Synergistic effect of the first, second, and third components of this disclosure.

[0130] Comparative Example 1 and Example 2 do not contain the second component; other methods and parameters are the same as in Example 1. Comparative Example 2 does not contain a third component; other methods and parameters are the same as in Example 1. Comparative Example 3, Example 2, does not contain the second and third components; the parameters for other methods are the same as in Example 1. The results are shown in Table 1 below: Table 1

[0131] Conclusion: The combination of the second component and the first component, based on the addition of a catalyst, accelerates the reaction, bringing it closer to thermodynamic equilibrium, reducing the reaction potential energy, and thus accelerating the reaction. 13 CO2 and 12 The isotope exchange reaction rate of C-amine complexes promotes the formation and decomposition equilibrium of carbamates through proton transfer, shortens the time to reach equilibrium, and increases abundance; the addition of viscosity modifiers can reduce the viscosity of organic amines, increase the diffusion rate of ¹³C-amine complexes in the liquid phase, shorten the isotope exchange time, and reduce energy consumption.

[0132] Experimental Example 2: Screening Test for Catalyst Dosage The results are shown in Table 2 below: Table 2

[0133] Results: The optimal catalyst dosage for this invention is 1-4%. 13 CO2 abundance reached over 98%.

[0134] This disclosure proposes a complexing agent, separation device, and separation method for carbon isotopes, which have the following advantages over the prior art: First, this disclosure combines the second component with the first component to accelerate the isotope exchange reaction through proton transfer without reducing the amine complexation capacity, thereby shortening the time to reach equilibrium and improving the efficiency of single-stage separation.

[0135] Second, the first component of this disclosure is an organic amine, whose amino group forms a reversible carbamate complex with CO2. It has high selectivity for carbon dioxide, fast complexation reaction rate, high fractionation coefficient, large single-stage enrichment factor, and excellent thermal stability and resistance to high-temperature degradation.

[0136] Third, this public announcement is adopted 12 C has a stronger complexing ability with organic amines than 13 The characteristic of C is that it preferentially complexes in the complexation tower. 12 C, generating 12 C-amine complex, making the gas phase 13 C abundance was initially increased; then, through gas-liquid countercurrent contact... 13 C transfers from the gas phase to the liquid phase, increasing its abundance again; further high-temperature pyrolysis promotes the reverse reaction, further increasing its abundance. 13 C abundance.

[0137] It is understood that the above embodiments are merely exemplary embodiments used to illustrate the principles of this disclosure, and this disclosure is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and substance of this disclosure, and these modifications and improvements are also considered to be within the scope of protection of this disclosure.

Claims

1. A complexing agent for carbon isotope separation, characterized in that, The complexing agent comprises a first component and a second component; wherein... The first component is an organic amine; The second component is a catalyst, which is at least one of hydrochloric acid, sulfuric acid, or carboxylic acid; the carboxylic acid has the general structural formula R1COOH or R2(COOH)2, wherein R1 is one of hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, isopentyl, and cyclopentyl, and R2 is one of methylene, ethylene, propylene, and methyl ethylene.

2. The complexing agent according to claim 1, characterized in that, The content of the catalyst is 0.5-5% of the content of the organic amine.

3. The complexing agent according to claim 1, characterized in that, The carboxylic acid is any one of acetic acid, malonic acid, and formic acid.

4. The complexing agent according to claim 1, characterized in that, The organic amine is selected from compounds of Formula 1 below: R1, R2, and R3 are independently selected from hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, isopentyl, methoxymethyl, ethoxymethyl, methoxyethyl, ethoxyethyl, phenyl, benzyl, phenoxymethyl, phenoxyethyl, cyclopentyl, cyclohexyl, cyclopentylmethyl, hydroxymethyl, hydroxyethyl, hydroxypropyl, aminomethyl, aminoethyl, aminopropyl, fluoromethyl, fluoroethyl, chloromethyl, chloroethyl, bromomethyl, bromoethyl, difluoromethyl, trifluoromethyl, aryl, or heteroaryl, wherein the heteroatom of the heteroaryl group is N.

5. The complexing agent according to claim 1, characterized in that, The organic amine is at least one of diethanolamine, diethylamine, ethylene glycolamine, butanediamine, triethanolamine, N-methylaniline, p-phenylenediamine, piperidine, and pyrrolidine.

6. The complexing agent according to any one of claims 1-5, characterized in that, The complexing agent also includes a viscosity modifier, which is any one of small molecule hydrocarbons, small molecule ethers, and small molecule ketones. The small molecule hydrocarbon is selected from C5-C6. 10 Alkanes, C5-C 10 Cycloalkanes, C5-C 10 Aromatic hydrocarbons, C5-C 10 heteroaromatics or C5-C 10 Olefins; the C5-C 10 The alkane is optionally substituted with 1, 2, or 3 halogens; the C5-C 10 The cycloalkanes are optionally substituted with 1, 2, or 3 halogens; the C5-C 10 The aryl hydrocarbon is optionally substituted with one, two, or three halogens; the C5-C 10 The heteroaromatic hydrocarbons are optionally substituted with 1, 2 or 3 halogens or the C5-C... 10 Alkenes may be optionally substituted with 1, 2 or 3 halogens; The small molecule ether is represented by the general formula R3OR4, wherein R3 and R4 are independently selected from C1-C1. 10 Alkyl, C3-C 10 cycloalkyl or C5-C 10 Aryl, the C1-C 10 The alkyl group may optionally be substituted with a C1-C3 alkyl group, wherein the C5-C 10 The aryl group may be optionally substituted with a C1-C3 alkyl group; the C3-C 10 The cycloalkyl group may be optionally substituted with a C1-C3 alkyl group; The small molecule ketone is represented by the following general formula R5(C=O)R6, wherein R5 and R6 are independently selected from C1-C6. 10 Alkyl, C3-C 10 cycloalkyl, C5-C 10 Aryl groups or R5, R6 form cyclic ketones with C=O, wherein the C1-C 10 The alkyl group may optionally be substituted with a C1-C3 alkyl group, wherein the C5-C 10 The aryl group may be optionally substituted with a C1-C3 alkyl group, wherein the C3-C 10 The cycloalkyl group may optionally be substituted with a C1-C3 alkyl group; the cycloketone may optionally be substituted with a C1-C3 alkyl group.

7. The complexing agent according to claim 6, characterized in that, The small molecule hydrocarbon is selected from one of 1-chloropentane, 1,2-dichloropentane, 1-chlorohexane, n-heptane, 1-chlorooctane, dichlorocyclohexane, and chlorocyclopentane.

8. The complexing agent according to claim 6, characterized in that, The small molecule ether is selected from one of diisopropyl ether, methyl tert-butyl ether, ethyl tert-butyl ether, or di-n-propyl ether.

9. The complexing agent according to claim 6, characterized in that, The small molecule ketone is selected from one of cyclopentanone, cyclohexanone, methylcyclopentanone, methylcyclohexanone, and methyl isobutyl ketone.

10. The complexing agent according to claim 6, characterized in that, The viscosity modifier content is 10-30% of the organic amine content.

11. A method for separating carbon isotopes, characterized in that, The separation method includes: Carbon dioxide and a complexing agent are introduced into a complexing tower, wherein the molar ratio of carbon dioxide to complexing agent is (0.20~0.80):

1. The carbon dioxide is then introduced at 25-35℃. 12 CO2 complexes with organic amines to form... 12 C-amine complex; the complexing agent is the complexing agent according to any one of claims 1-7; The 12 The C-amine complex flows into an exchange tower, and carbon dioxide gas is introduced into the exchange tower. At 10-60°C, the carbon dioxide... 13 CO2 and the above 12 The C-amine complex undergoes an exchange reaction to generate 12 CO2 and 13 C-amine complex; The 13 The C-amine complex is decomposed in a cracking tower at a temperature of 100-250℃ into cracking products and... 13 CO2; The pyrolysis products form organic amines and impurities in a purification tower, the impurities including catalysts and optionally viscosity modifiers.

12. A high abundance 13 C carbon isotopes, characterized by... The high abundance 13 The C isotope is obtained by the separation method described in claim 11. 13 CO2 13 The abundance of C isotopes is over 99%.

Images