A carbon isotope separation device and separation method

Abstract

This application discloses a carbon isotope separation device and method, belonging to the field of isotope generation technology. The separation device includes: a complexation tower, an exchange tower, a cracking tower, and a purification tower connected in sequence; in the complexation tower, carbon dioxide... 12 C complexes with an organic amine complexing agent to form... 12 C-amine complex; in the exchange tower, carbon dioxide 13 C and 12 The C-amine complex undergoes an exchange reaction to generate 12 CO2 and 13 C-amine complex; in the cracking tower 13 C-amine complexes undergo thermal pyrolysis to produce pyrolysis products and 13 CO2; In the impurity removal tower, impurities in the pyrolysis products are adsorbed by the adsorbent, and organic amines are discharged. The separation method disclosed herein is simple, highly efficient, energy-saving, and has high carbon isotope abundance. Simultaneously, the adsorbent disclosed herein can remove the "colloidal substances" produced by amine oxidation with a high removal rate, ensuring the purity of the circulating system and allowing the organic amines to be recycled.

Description

Technical Field

[0001] This disclosure belongs to the field of isotope generation technology, specifically relating to a carbon isotope separation device and separation method. 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] There are many methods for producing and separating stable isotopes. Early methods mainly included thermal diffusion, electrolysis, laser methods, centrifugation, and adsorption. Currently, the industrial production method for carbon isotopes is cryogenic distillation, which has low separation efficiency and isotope abundance. Furthermore, the impurity removal stage generally employs vacuum distillation, which is complex and difficult to remove colloidal polymer impurities. Therefore, how to further improve the abundance of carbon isotopes and the impurity removal rate is a pressing problem to be solved in this field. Summary of the Invention

[0004] This disclosure aims to at least solve one of the technical problems existing in the prior art, and to provide a carbon isotope separation device and separation method.

[0005] In one aspect, this disclosure provides a carbon isotope separation apparatus, the separation apparatus comprising: The complexing tower has a first gas inlet at its bottom for introducing carbon dioxide and a gas outlet for discharging gas. 12 The first outlet of the C-amine complex has a first inlet at the top for introducing a complexing agent, which includes an organic amine. In the complexing tower, carbon dioxide... 12 CO2 complexes with organic amines to form... 12 C-amine complex; The exchange tower has a second gas inlet at its bottom 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, in the exchange tower, contains carbon dioxide... 13 CO2 and 12 The C-amine complex undergoes an exchange reaction to generate 12CO2 and 13 C-amine complex; The pyrolysis tower has a third outlet at its bottom for discharging pyrolysis products, and a third inlet at its top connected to the second outlet, as well as a discharge outlet. 13 The second CO2 gas outlet is located in the cracking tower. 13 C-amine complexes undergo thermal pyrolysis to produce pyrolysis products and 13 CO2; The impurity removal tower has a fourth inlet at its top connected to the third outlet and a fourth outlet at its bottom for discharging organic amines. In the impurity removal tower, impurities in the pyrolysis products are adsorbed by an adsorbent, and organic amines are discharged from the fourth outlet. The adsorbent is added from any of the first to fourth inlets.

[0006] Optionally, the adsorbent is surface-modified activated carbon.

[0007] Optionally, the surface-modified activated carbon is porous activated carbon with surface oxygen modification and a specific surface area ≥400 m². 2 / g, oxygen content 5~15wt%.

[0008] Optionally, the organic amine is selected from compounds of Formula 1 below.

[0009] 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.

[0010] 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.

[0011] Optionally, R1, R2, and R3 are independently selected from hydrogen or C1-C3 alkyl groups, wherein the C1-C3 alkyl groups are substituted with hydroxyl or methoxy groups, and R1, R2, and R3 are not simultaneously hydrogen.

[0012] Optionally, R1 is hydrogen, R2 and R3 are selected from hydrogen or C1-C3 alkyl groups, wherein the C1-C3 alkyl groups are substituted with hydroxyl or methoxy groups, and R2 and R3 are not both hydrogen.

[0013] Optionally, the organic amine complexing agent includes primary amines, secondary amines, tertiary amines, or aromatic amines.

[0014] 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.

[0015] 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.

[0016] 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.

[0017] 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.

[0018] Optionally, the organic amine is at least one selected from diethanolamine, diethylamine, ethylene glycolamine, butanediamine, triethanolamine, N-methylaniline, p-phenylenediamine, piperidine, and pyrrolidine.

[0019] Optionally, the molar ratio of carbon dioxide to organic amine 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.

[0020] Optionally, the complexing agent further includes one or more of a viscosity modifier, a catalyst, and a low-boiling-point solvent. Multiple components.

[0021] Optionally, the viscosity modifier and / or catalyst are added through a first inlet or a second inlet; the low-boiling-point solvent is added through a third inlet.

[0022] Optionally, the viscosity modifier is any one of small molecule hydrocarbons, small molecule ethers, and small molecule ketones.

[0023] 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... 10 The olefin is optionally substituted with one, two, or three halogens; preferably, the halogens include one or more of fluorine, chlorine, and bromine. More preferably, 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 R1OR2, wherein R1 and R2 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 optionally be substituted with a C1-C3 alkyl group; preferably, R1 and R2 are independently selected from one of methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, isopentyl, cyclopentyl, n-hexyl, isohexyl, cyclohexyl, phenyl, benzyl, etc. More preferably, the small molecule ether is selected from diisopropyl ether, methyl tert-butyl ether, ethyl tert-butyl ether, or di-n-propyl ether.

[0025] Optionally, the small molecule ketone is represented by the following general formula R1(C=O)R2, wherein R1 and R2 are independently selected from C1-C2. 10 Alkyl, C3-C 10 cycloalkyl, C5-C 10 Aryl groups or R1, R2 form cyclic ketones with C=O, wherein the C1-C10 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 is optionally substituted with a C1-C3 alkyl group; the cycloketone is optionally substituted with a C1-C3 alkyl group; preferably, R1 and R2 are independently selected from methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, isopentyl, cyclopentyl, n-hexyl, isohexyl, cyclohexyl, phenyl, benzyl, or R1 and R2 form a C4-C8 cycloketone with C=O; more preferably, the small molecule ketone is selected from cyclopentanone, cyclohexanone, methylcyclopentanone, methylcyclohexanone, methyl isobutyl ketone, etc.

[0026] 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%.

[0027] Optionally, the catalyst 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.

[0028] Optionally, the carboxylic acid is any one of acetic acid, malonic acid, and formic acid.

[0029] Optionally, the catalyst is one or more of hydrochloric acid, sulfuric acid, acetic acid, malonic acid, and formic acid.

[0030] 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%.

[0031] Optionally, the low-boiling solvent is selected from C3-C6 alkanes or C3-C6 cycloalkanes, wherein the C3-C6 alkanes or C3-C6 cycloalkanes are optionally substituted with one, two, or three halogens, including fluorine, chlorine, or bromine. Preferably, the low-boiling solvent is selected from 1-chloropentane, 1,2-dichloropentane, 1-chlorohexane, dichlorocyclohexane, chlorocyclopentane, or butyrochloroethane.

[0032] Optionally, the organic amine is added prior to the complexation reaction, and the low-boiling solvent is added prior to the pyrolysis reaction.

[0033] Optionally, the content of the low-boiling-point solvent is 5%-25% of the organic amine content. For example, 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, or 25%.

[0034] Optionally, the temperature of the complexing tower is 25-35°C; The temperature of the exchange tower is 10-60℃; The heating and pyrolysis temperature of the pyrolysis tower is 100-250℃.

[0035] Optionally, the fourth discharge port is connected to the first inlet port.

[0036] In another aspect of this disclosure, a method for separating carbon isotopes is proposed, the method comprising: Prepare organic amines, viscosity modifiers, catalysts, and low-boiling-point solvents for later use; Carbon dioxide, organic amines, a catalyst, and a viscosity modifier are introduced into the complexing tower. The carbon dioxide... 12 CO2 complexes with organic amines to form... 12 C-amine complex; The 12 The C-amine complex flows into an exchange tower, and carbon dioxide gas is introduced into the exchange tower. The carbon dioxide contains... 13 CO2 and the above 12 The C-amine complex undergoes an exchange reaction to generate 12 CO2 and 13 C-amine complex; A low-boiling-point solvent is added to the cracking tower, wherein the low-boiling-point solvent and 13 C-amine complexes are mixed and then heated in a cracking tower to decompose into cracking products and... 13 CO2; Impurities in the pyrolysis products are adsorbed by the adsorbent, and organic amines are discharged.

[0037] In another aspect, this disclosure provides a 13 The C isotope is prepared by the aforementioned separation method. 13 C isotope abundance is above 99.00%.

[0038] This disclosure discloses a carbon isotope separation apparatus and method. The separation apparatus includes a complexing tower, the bottom of which is provided with a first gas inlet for introducing carbon dioxide and a outlet for discharging carbon dioxide. 12 The first outlet of the C-amine complex has a first inlet at the top for introducing a complexing agent, which includes an organic amine. In the complexing tower, carbon dioxide... 12C complexes with organic amines to form 12 C-amine complex; exchange tower, the bottom of which 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, in the exchange tower, contains carbon dioxide... 13 C and 12 The C-amine complex undergoes an exchange reaction to generate 12 CO2 and 13 C-amine complex; a cracking tower, having a third outlet at the bottom for discharging cracking products, and a third inlet at the top connected to the second outlet, and a discharge outlet. 13 The second CO2 gas outlet is located in the cracking tower. 13 C-amine complexes undergo thermal pyrolysis to produce pyrolysis products and 13 A CO2 removal tower has a fourth inlet at its top connected to the third outlet and a fourth outlet at its bottom for discharging organic amines. In this removal tower, impurities in the pyrolysis products are adsorbed by an adsorbent, and the organic amines are discharged from the fourth outlet. This separation method is simple, highly efficient, energy-saving, and has high carbon isotope abundance. Furthermore, the adsorbent used in this method can remove the "colloidal substances" produced by amine oxidation with a high removal rate, ensuring the purity of the circulating system and allowing the organic amines to be recycled. Attached Figure Description

[0039] 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

[0040] 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.

[0041] like Figure 1As shown, one aspect of this disclosure provides a carbon isotope separation device 100, comprising: a complexing tower 110, an exchange tower 120, a pyrolysis 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 top inlet for introducing a complexing agent, which includes an organic amine, a viscosity modifier, a catalyst, and a low-boiling-point solvent. The organic amine, viscosity modifier, and catalyst are added through the first inlet. In this complexing tower 110, carbon dioxide... 12 C 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 C and 12 The C-amine complex undergoes an exchange reaction to generate 12 CO2 and 13 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. The low-boiling-point solvent in the complexing agent is added to the cracking tower 130 through the third inlet. In the cracking tower 130, the low-boiling-point solvent and... 13 C-amine complexes are mixed and then heated to decompose into pyrolysis products and... 13 CO2, 13 CO2 is discharged through the second gas outlet, and the pyrolysis products are discharged into the impurity removal tower through the third outlet. The top of the impurity removal tower 140 is provided with a fourth inlet connected to the third outlet, and the bottom is provided with a fourth outlet for discharging organic amines. In the impurity removal tower, the adsorbent is filled into the impurity removal tower through the fourth inlet. In this way, impurities in the pyrolysis products are adsorbed by the adsorbent, and organic amines are discharged from the fourth outlet.

[0042] It should be understood that during the recycling process, amine complexing agents easily generate colloidal polymer impurities due to trace amounts of O2 oxidation or high-temperature condensation. These impurities contain a large number of polar groups in their chemical structure, which current distillation methods cannot remove, leading to increased viscosity of the amine solution, decreased heat transfer efficiency, and other issues. Furthermore, these methods are complex and time-consuming. To address this, this embodiment introduces an adsorbent during the impurity removal stage. Utilizing the porous adsorption sites of the adsorbent, it can effectively adsorb the aforementioned colloidal polymer impurities, achieving a high removal rate and a simple process.

[0043] In some preferred embodiments, the adsorbent is surface-modified activated carbon.

[0044] As a further preferred option, the surface-modified activated carbon is a porous activated carbon with surface oxygen modification and a specific surface area ≥400m². 2 / g, oxygen content 5~15wt%.

[0045] In this embodiment, modified activated carbon is used to directionally adsorb impurities through surface groups, further improving the adsorption rate.

[0046] It should also be understood that after removing impurities, the purity of the organic amines decomposed from the pyrolysis products is improved, enabling them to be recycled, reducing costs and improving separation efficiency.

[0047] 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.

[0048] 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.

[0049] In some other preferred embodiments, the molar ratio of carbon dioxide to organic amine is (0.20~0.80):1.

[0050] Furthermore, the complexing agent in this embodiment may also include a viscosity modifier, the content of which is 10-30% of the organic amine content. The viscosity modifier is preferably any one of small molecule hydrocarbons, small molecule ethers, and small molecule ketones. This component can break the hydrogen bonds between amine molecules, and based on the fact that the viscosity modifier is a small molecule organic compound, it inserts into the gaps between amine molecules through the molecular dilution effect, physically separating the molecules, and further reducing the viscosity of the organic amine liquid. In this way, in the exchange reaction, the diffusion rate of the ¹³C-amine complex in the liquid phase is increased, the isotope exchange time is shortened, and energy consumption is reduced.

[0051] It should be understood that the above-mentioned viscosity modifier can be added simultaneously with the organic amine during the complexation stage, that is, the viscosity modifier and the organic amine can be added simultaneously through the first feed port, or it can be added separately to the exchange tower, that is, the viscosity modifier can be added separately through other feed ports on the exchange tower. There is no specific limitation on this.

[0052] In some preferred embodiments, the small molecule hydrocarbon is preferably C 5- C 10 Halogenated hydrocarbons, such as chloroalkanes, including 1-chloropentane, 1,2-dichloropentane, 1-chlorohexane, 1-chlorooctane, etc.; and halogenated cycloalkanes, including chlorocycloalkanes, dichlorocyclohexane, chlorocyclopentane, etc.

[0053] 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.

[0054] 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.

[0055] Furthermore, the complexing agent in this embodiment may also include a catalyst, the content of which is 0.5-5% of the organic amine content. The catalyst is preferably at least one of hydrochloric acid, sulfuric acid, and carboxylic acid, used to accelerate... 13 CO2 complexes with amines to form... 13 The rate of C-amine complexes is increased, reaction efficiency is improved, isotope abundance is increased, and time is further shortened, while the amount of organic amines used is reduced, thus lowering energy consumption.

[0056] It should be understood that the catalyst can be added simultaneously with the organic amine during the complexation stage, i.e., the catalyst and the organic amine can be added simultaneously through the first feed inlet, or it can be added separately to the exchange tower, i.e., the catalyst can be added separately through other feed inlets on the exchange tower. No specific limitation is made in this regard.

[0057] In some preferred embodiments, the catalyst may preferably be a carboxylic acid, such as acetic acid, malonic acid, formic acid, etc.

[0058] 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.

[0059] Furthermore, the complexing agent in this embodiment also contains a low-boiling-point solvent, which includes at least one of small-molecule hydrocarbons and small-molecule haloalkanes.

[0060] In some preferred embodiments, the small molecule hydrocarbons are preferably C3-C6 chain hydrocarbons, such as C3-C6 straight-chain alkanes or C3-C6 branched-chain alkanes. The chain hydrocarbon molecules have a linear structure, weak intermolecular forces, and extremely low viscosity. Adding them to the amine solution can significantly reduce the viscosity of the system.

[0061] In other preferred embodiments, the small molecule hydrocarbon may preferably be a C3-C6 cyclic hydrocarbon, such as cyclohexane, cyclopentane, methylcyclohexane, etc.

[0062] In some preferred embodiments, the low-boiling solvent is selected from 1-chloropentane, 1,2-dichloropentane, 1-chlorohexane, dichlorocyclohexane, chlorocyclopentane, or butyrochloroethane.

[0063] In some preferred embodiments, the content of the low-boiling-point solvent is 5%-25% of the organic amine content.

[0064] It should be understood that the aforementioned low-boiling-point solvent can be added simultaneously with the organic amine in the complexation stage, that is, the low-boiling-point solvent and the organic amine are added simultaneously through the first feed port, or it can be added separately to the cracking tower, that is, the catalyst is added separately through other feed ports on the cracking tower. In addition, the low-boiling-point solvent can also be added in the exchange stage, through other feed ports on the exchange tower. In other words, the low-boiling-point solvent can be added throughout the entire process, thereby improving the utilization rate of the recycled materials throughout the entire process.

[0065] In this embodiment, in addition to improving the impurity removal process, the complexing agent has also been optimized. For example, a low-boiling-point solvent or a catalyst and viscosity modifier are added to the organic amine to make the four components work synergistically. The mass transfer and reaction of the viscosity modifier and the catalyst are synergistic. Based on mass transfer, the catalyst accelerates the reaction through proton transfer. 12 C-amine complex decomposition and 13 CO2 complexation, along with the synergistic effect of both, enhances the "mass transfer-reaction matching degree" of isotope exchange. Meanwhile, low-boiling-point solvents are used to lower the pyrolysis temperature, reduce amine side reactions, improve regeneration rate, ensure the recycling of viscosity modifiers and catalysts, and reduce damage to high-temperature reactor catalysts and viscosity modifiers.

[0066] 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.

[0067] 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.

[0068] 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.

[0069] 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.

[0070] 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 its formation. The large contact area provided by the packing material allows the exchange reaction to proceed fully, resulting in the continuous enrichment of ¹³C in the liquid phase. A ¹³C concentration gradient forms along the column height, with the highest ¹³C abundance in the liquid phase at the top and the lowest in the gas phase at the bottom.

[0071] 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.

[0072] 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.

[0073] Furthermore, the cracking tower can be a plate tower. In the cracking tower, the liquid phase is violently agitated by rising bubbles on the tower plate. The ¹³C-amine complex undergoes reversible decomposition at high temperature, generating a regenerated amine liquid phase and a ¹³CO2 gas phase. The ¹³CO2 in the bubbles flows upward and enters the separation section, while the regenerated amine flows downward along the downcomer, collects in the tower bottom, and is pumped to the impurity removal tower for purification and recycling.

[0074] This embodiment 13 C-amine complexes decompose upon heating into organic amines and 13 The heating and decomposition temperature of CO2 is 80-150℃. High temperatures promote the reverse reaction, resulting in the targeted release of high-purity CO2. 13 CO2, avoid 13 C loss.

[0075] Furthermore, the impurity removal tower can be a fixed-bed adsorption tower, where the adsorbent is filled from top to bottom, and the amine solution flows axially through the bed from top to bottom. Impurities are trapped by the adsorbent, and the purified amine solution flows out from the bottom of the tower. For example, modified activated carbon can be filled in both the upper and lower layers.

[0076] 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 amine complexing agent to participate in the reaction further, be recycled, and reduce costs.

[0077] 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 an organic amine complexing agent are introduced into the complexing tower. The carbon dioxide contains... 12 C complexes with organic amines to form 12 The reaction process of the C-amine complex is as follows: 12 CO2 + RNH2 RNH 12 COOH ( 12 C-amine complex).

[0078] 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 (decomposition of the complex) is inhibited, and the ¹²C separation efficiency is improved.

[0079] It should be noted that the complexing agent in this embodiment may also include a catalyst, a viscosity modifier, and a low-boiling-point solvent. The low-boiling-point solvent may be added in step S110 to mix with the organic amine and then added to the complexing tower. Alternatively, the low-boiling-point solvent may be added to the cracking tower in step S230. Similarly, the viscosity modifier and catalyst may be added in step S110 to mix with the organic amine and then added to the complexing tower. Alternatively, the components may be added to the exchange tower in step S220.

[0080] It should be further noted that the specific components and contents of the catalyst, viscosity modifier and low-boiling-point solvent mentioned above are described in the previous text and will not be repeated here.

[0081] S220, 12 The C-amine complex flows into the exchange tower, and carbon dioxide gas is introduced into the exchange tower, so that the 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, thus forming 12 CO2 is directly discharged from the exchange tower and collected. 13 The C-amine complex further flows into the cracking tower, where the reaction process is as follows: 13 CO2+RNH 12 COOH ( 12 C-amine complex) 12 CO2+ RNH 13 COOH ( 13 C-amine complex).

[0082] In step S220, the temperature of the exchange tower is set to 10-60℃. At this temperature, the isotope exchange equilibrium constant K is optimized to make... 13 C migrates into the liquid phase.

[0083] 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.

[0084] The heating and pyrolysis temperature of the S230 pyrolysis tower is 100-250℃. High temperature promotes the reverse reaction and directionally releases high-purity [product / material]. 13 CO2, avoid 13 C loss.

[0085] S240, Impurities in the pyrolysis products are adsorbed by the adsorbent, and organic amines are discharged.

[0086] Specifically, the impurity removal tower can be a fixed-bed adsorption tower, with the adsorbent filled from top to bottom. The amine solution flows axially through the bed from top to bottom, and impurities are trapped by the adsorbent. The purified amine solution flows out from the bottom of the tower. For example, modified activated carbon can be packed in both the upper and lower layers. The separation method disclosed in this invention is simple, has high separation efficiency, low energy consumption, and high carbon isotope abundance. Furthermore, the adsorption method effectively removes colloidal polymer impurities, improving the purity of organic amines.

[0087] The carbon dioxide gas introduced into the complexation tower and exchange tower of this disclosure has a natural abundance¹³C of approximately 1.1%,¹ 2 C is approximately 98.89%.

[0088] 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.

[0089] 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, an organic amine, a viscosity modifier, and a catalyst are introduced into the complexation tower. The organic amine is diethanolamine, the catalyst is formic acid, and the viscosity modifier is 1-chlorohexane. The catalyst content is 3% of the organic amine content, and the viscosity modifier content is 20% of the organic amine content. The molar ratio of carbon dioxide to organic amine is 0.35:1. At 30°C, the carbon dioxide... 12 CO2 complexes with organic amines to form... 12 C-amine complex, at this time 12 The C-amine complex flows into the exchange tower.

[0090] 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.

[0091] S3. Add the low-boiling-point solvent chlorobutane to the cracking tower, and... 13 The C-amine complex mixture was heated to 105°C and then pyrolyzed into pyrolysis products and... 13 CO2, wherein the content of the low-boiling-point solvent is 15% of the organic amine content.

[0092] S4. In the impurity removal tower, the pyrolysis products are adsorbed by the adsorbent to form organic amines and impurities. The organic amines further participate in the complexation reaction in step S1.

[0093] Specifically, the impurity removal tower can be a fixed-bed adsorption tower, where the adsorbent is filled from top to bottom, and the amine solution flows axially through the bed from top to bottom. Impurities are trapped by the adsorbent, and the purified amine solution flows out from the bottom of the tower. For example, the upper layer can be filled with modified activated carbon, and the lower layer can be filled with oxygen-modified activated carbon. The modified activated carbon is a porous activated carbon with oxygen-modified surface and a specific surface area ≥400 m². 2 / g, oxygen content 5~15wt%.

[0094] Detection method: Inductively coupled plasma mass spectrometry.

[0095] After analysis and testing 12 The abundance of CO2 was 0.008%. 13 The abundance of CO2 was 99.992%.

[0096] Example 2 S1. Carbon dioxide, an organic amine, a viscosity modifier, and a catalyst are introduced into the complexation tower. The organic amine is diethanolamine, the catalyst is malonic acid, and the viscosity modifier is 1-chlorohexane. The catalyst content is 3% of the organic amine content, the viscosity modifier content is 20% of the organic amine content, and the molar ratio of carbon dioxide to organic amine is 0.4:1. 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.

[0097] 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.

[0098] S3. Add chlorobutane, a low-boiling-point solvent, to the cracking tower. The content of the low-boiling-point solvent is 15% of the organic amine content. 13 The C-amine complex mixture was heated to 110°C and then pyrolyzed into pyrolysis products and... 13 CO 2。

[0099] S4. The pyrolysis products form complexing agents and impurities in the impurity removal tower.

[0100] Specifically, the impurity removal tower can be a fixed-bed adsorption tower, with the adsorbent filled from top to bottom. The amine solution flows axially through the bed from top to bottom, and impurities are trapped by the adsorbent. The purified amine solution flows out from the bottom of the tower. For example, modified activated carbon can be filled in both the upper and lower layers. The modified activated carbon is a porous activated carbon with oxygen-modified surface and a specific surface area ≥400 m². 2 / g, oxygen content 5~15wt%.

[0101] After analysis and testing 12 The abundance of CO2 was 0.003%. 13 The abundance of CO2 was 99.997%.

[0102] Example 3 S1. Carbon dioxide, an organic amine, a viscosity modifier, and a catalyst are introduced into the complexation tower. The organic amine is diethanolamine, the catalyst is malonic acid, and the viscosity modifier is diisopropyl ether. The catalyst content is 3% of the organic amine content, and the viscosity modifier content is 20% of the organic amine content. The molar ratio of carbon dioxide to diethanolamine is 0.45:1. 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.

[0103] 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.

[0104] S3. Add butane, a low-boiling-point solvent, to the cracking tower. The content of the low-boiling-point solvent is 15% of the organic amine content. 13 The C-amine complex was decomposed in a cracking column at 100°C into cracking products and... 13 CO2.

[0105] S4. The pyrolysis products form complexing agents and impurities in the impurity removal tower.

[0106] Specifically, the impurity removal tower can be a fixed-bed adsorption tower, with the adsorbent filled from top to bottom. The amine solution flows axially through the bed from top to bottom, and impurities are trapped by the adsorbent. The purified amine solution flows out from the bottom of the tower. For example, modified activated carbon can be filled in both the upper and lower layers. The modified activated carbon is a porous activated carbon with oxygen-modified surface and a specific surface area ≥400 m². 2 / g, oxygen content 5~15wt%.

[0107] After analysis and testing 12 The abundance of CO2 was 0.005%. 13 The abundance of CO2 was 99.995%.

[0108] Example 4 S1. Carbon dioxide, an organic amine, a viscosity modifier, and a catalyst are introduced into the complexation tower. The organic amine is diethanolamine, the catalyst is formic acid, the viscosity modifier is n-heptanone, the catalyst content is 3% of the organic amine content, and the viscosity modifier content is 20% of the organic amine content. The molar ratio of carbon dioxide to diethanolamine is 0.5:1. At 38°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.

[0109] 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.

[0110] S3. Add low-boiling-point solvent chloropropane to the cracking tower. The content of the low-boiling-point solvent is 15% of the organic amine content. 13 The C-amine complex was decomposed in a cracking tower at 120°C into cracking products and... 13 CO2.

[0111] S4. The pyrolysis products form complexing agents and impurities in the impurity removal tower.

[0112] Specifically, the impurity removal tower can be a fixed-bed adsorption tower, with the adsorbent filled from top to bottom. The amine solution flows axially through the bed from top to bottom, and impurities are trapped by the adsorbent. The purified amine solution flows out from the bottom of the tower. For example, modified activated carbon can be filled in both the upper and lower layers. The modified activated carbon is a porous activated carbon with oxygen-modified surface and a specific surface area ≥400 m². 2 / g, oxygen content 5~15wt%.

[0113] After analysis and testing 12 The abundance of CO2 was 0.008%. 13 The abundance of CO2 was 99.992%.

[0114] 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.

[0115] R=HO-CH2-CH2- The specific methods include the following: S1. Carbon dioxide, an organic amine, a viscosity modifier, and a catalyst are introduced into the complexation tower. The organic amine is ethylene glycol amine, the catalyst is formic acid, and the viscosity modifier is ethyl tert-butyl ether. The catalyst content is 3% of the organic amine content, and the viscosity modifier content is 20% of the organic amine content. The molar ratio of carbon dioxide to diethanolamine is 0.5:1. 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.

[0116] S2, 12 The 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.

[0117] S3. Add the low-boiling-point solvent 1-chloropentane to the cracking tower. The content of the low-boiling-point solvent is 15% of the organic amine content. 13 The C-amine complex mixture was heated to 125°C and then pyrolyzed into pyrolysis products and... 13 CO2.

[0118] S4. The pyrolysis products form complexing agents and impurities in the impurity removal tower.

[0119] Specifically, the impurity removal tower can be a fixed-bed adsorption tower, with the adsorbent filled from top to bottom. The amine solution flows axially through the bed from top to bottom, and impurities are trapped by the adsorbent. The purified amine solution flows out from the bottom of the tower. For example, modified activated carbon can be filled in both the upper and lower layers. The modified activated carbon is a porous activated carbon with oxygen-modified surface and a specific surface area ≥400 m². 2 / g, oxygen content 5~15wt%.

[0120] After analysis and testing 12 The abundance of CO2 was 0.001%. 13 The abundance of CO2 is 99.999%.

[0121] 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 -

[0122] R3NH + H 13 CO3 - R3N+ 13 CO2 + H2O Where R=(HOCH2CH2)3- S1. Carbon dioxide, organic amine, viscosity modifier, and catalyst are introduced into the complexation tower. The catalyst is acetic acid, and the viscosity modifier is cyclohexanone. The catalyst content is 3% of the organic amine content, and the viscosity modifier content is 20% of the organic amine content. The molar ratio of carbon dioxide to triethanolamine is 0.6:1. At 40°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.

[0123] S2, 12 The 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 generate12 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.

[0124] S3. Add 1,2-dichloropentane, a low-boiling-point solvent, to the cracking tower. The content of the low-boiling-point solvent is 15% of the organic amine content. 13 The C-amine complex was decomposed in a cracking column at 130°C into cracking products and... 13 CO2.

[0125] S4. The pyrolysis products form complexing agents and impurities in the impurity removal tower.

[0126] Specifically, the impurity removal tower can be a fixed-bed adsorption tower, with the adsorbent filled from top to bottom. The amine solution flows axially through the bed from top to bottom, and impurities are trapped by the adsorbent. The purified amine solution flows out from the bottom of the tower. For example, modified activated carbon can be filled in both the upper and lower layers. The modified activated carbon is a porous activated carbon with oxygen-modified surface and a specific surface area ≥400 m². 2 / g, oxygen content 5~15wt%.

[0127] After analysis and testing 12 The abundance of CO2 was 0.009%. 13 The abundance of CO2 was 99.991%.

[0128] Example 7 S1. Carbon dioxide, an organic amine, a viscosity modifier, and a catalyst are introduced into the complexation tower. The organic amine is N-methylaniline, the catalyst is sulfuric acid, the viscosity modifier is dichlorocyclohexane, and the content of dichlorocyclohexane is 20% of the organic amine. The content of sulfuric acid is 3% of the organic amine, and the molar ratio of carbon dioxide to organic amine 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.

[0129] S2, 12 The C-amine complex flows into the exchange column, and carbon dioxide gas is introduced into the exchange column. At 45°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.

[0130] S3. Add chlorobutane, a low-boiling-point solvent, to the cracking tower. The content of the low-boiling-point solvent is 15% of the organic amine content. 13 The C-amine complex mixture was heated to 130°C and then pyrolyzed into pyrolysis products and... 13 CO 2。

[0131] S4. The pyrolysis products form complexing agents and impurities in the impurity removal tower.

[0132] Specifically, the impurity removal tower can be a fixed-bed adsorption tower, with the adsorbent filled from top to bottom. The amine solution flows axially through the bed from top to bottom, and impurities are trapped by the adsorbent. The purified amine solution flows out from the bottom of the tower. For example, modified activated carbon can be filled in both the upper and lower layers. The modified activated carbon is a porous activated carbon with oxygen-modified surface and a specific surface area ≥400 m². 2 / g, oxygen content 5~15wt%.

[0133] After analysis and testing 12 The abundance of CO2 was 0.005%. 13 The abundance of CO2 was 99.995%.

[0134] Experiment 1: Screening of Impurity Removal Methods Comparative Group 1: Specifically, in step S4 of Example 1, "The impurity removal tower can be a fixed-bed adsorption tower, with the adsorbent filled from top to bottom, and the amine liquid flowing axially through the bed from top to bottom. Impurities are trapped by the adsorbent, and the purified amine liquid flows out from the bottom of the tower. For example, the upper layer can be filled with modified activated carbon, and the lower layer can also be filled with modified activated carbon. The modified activated carbon is a porous activated carbon with surface oxygen modification and a specific surface area ≥400 m²." 2 / g, oxygen content 5~15wt%.

[0135] Replace "Specifically, the impurity removal tower is an azeotropic distillation tower. Under reduced pressure, most organic amines form a minimum azeotrope with water, which is then condensed and separated into an aqueous phase and an amine phase. The amine phase is discharged through the fourth outlet, while some other 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." Other steps and parameters remain unchanged.

[0136] Table 1

[0137] Results: As shown in Table 1, the adsorbent purification method used in this application can improve the purity of organic amines compared to vacuum distillation, and further improve the purity of C-complexes in the complexation reaction, thereby improving... 13 CO2 abundance.

[0138] Experimental Example 2: Selection of Adsorbent Table 2

[0139] Results: As shown in Table 2, porous activated carbon with surface oxygen modification is the best adsorbent in the impurity removal tower, which can improve the purity of organic amines.

[0140] Synergistic effect of each component of the complexing agent in Experiment Example 3 The complexing agent components of Comparative Examples 1-5 are shown in Table 3 below. Other methods and parameters were prepared according to Example 1. Table 3

[0141] The results are as follows: (1) Significant catalytic effect: In the complete formulation (organic amine + catalyst + viscosity modifier + low melting point solvent, Example 1), the ¹³ CO₂ abundance reached 99.99%, and the reaction time was only 5 hours, which was the best among all experimental groups. In contrast, the abundance of the formulation without catalyst (Comparative Example 1, organic amine + viscosity modifier + low melting point solvent) decreased to 99.82%, and the reaction time was extended to 12 hours, indicating that the catalyst has a decisive promoting effect on the reaction rate and isotope selectivity.

[0142] (2) Lacking viscosity modifier (Comparative Example 2, organic amine + catalyst + low melting point solvent): abundance 99.78%, reaction time 8 hours; (3) Lacking low melting point solvent (Comparative Example 4, organic amine + catalyst + viscosity modifier): abundance 99.79%, reaction time 6.5 hours.

[0143] Comparative Examples 2 and 4 both showed inferior performance compared to the complete formulation, indicating that viscosity modifiers help improve mass transfer, while low-melting-point solvents are beneficial for maintaining homogeneity in the reaction system and for low-temperature operation. Both viscosity modifiers and low-melting-point solvents are indispensable: the absence of either component alone will lead to a decline in performance.

[0144] (4) The effect of using organic amine alone is the worst: when organic amine is used as the complexing agent (Comparative Example 1), the abundance of ¹³CO2 is only 97.53%, and the reaction time is as long as 12 hours, which confirms that a single component cannot meet the requirements of efficient enrichment.

[0145] In summary, the optimal complexing agent composition is a quaternary complex system consisting of organic amine, catalyst, viscosity modifier, and low-melting-point solvent. While ensuring a high abundance of 99.99%, it can shorten the reaction time to 5 hours, demonstrating significant comprehensive performance advantages.

[0146] This disclosure proposes a carbon isotope separation device and method, which has the following advantages compared to the prior art: First, the adsorbent disclosed herein can remove the "colloidal substance" produced by amine oxidation with a high removal rate, ensuring the purity of the circulation system and enabling the organic amine to be recycled again; Secondly, the complexing agent disclosed herein is an organic amine, whose amino group forms a reversible carbamate complex with CO2. This complex exhibits high selectivity for carbon dioxide, a fast complexing reaction rate, a high fractionation coefficient, and a large single-stage enrichment factor. Furthermore, it demonstrates excellent thermal stability and resistance to high-temperature degradation. Third, by combining organic amines with low-boiling-point solvents, catalysts and viscosity modifiers, this disclosure can reduce the pyrolysis temperature, reduce amine side reactions, improve regeneration rate, and synergistically improve the "mass transfer-reaction matching degree" of isotope exchange, shorten the time and reduce energy consumption.

[0147] 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 carbon isotope separation device, characterized in that, The separation device includes: The complexing tower has a first gas inlet at the bottom for introducing carbon dioxide and a gas outlet for discharging gas. 12 The first outlet of the C-amine complex has a first inlet at the top for introducing a complexing agent, which includes an organic amine. In the complexing tower, carbon dioxide... 12 CO2 complexes with organic amines to form... 12 C-amine complex; The exchange tower has a second gas inlet at its bottom 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, in the exchange tower, contains carbon dioxide... 13 CO2 and 12 The C-amine complex undergoes an exchange reaction to generate 12 CO2 and 13 C-amine complex; The pyrolysis tower has a third outlet at its bottom for discharging pyrolysis products, and a third inlet at its top connected to the second outlet, as well as a discharge outlet. 13 The second CO2 gas outlet is located in the cracking tower. 13 C-amine complexes undergo thermal pyrolysis to produce pyrolysis products and 13 CO2; The impurity removal tower has a fourth inlet at its top connected to the third outlet and a fourth outlet at its bottom for discharging organic amines. In the impurity removal tower, impurities in the pyrolysis products are adsorbed by an adsorbent, and organic amines are discharged from the fourth outlet. The adsorbent is added from any of the first to fourth inlets.

2. The separation device according to claim 1, characterized in that, The adsorbent is surface-modified activated carbon.

3. The separation device according to claim 2, characterized in that, The surface-modified activated carbon is a porous activated carbon with surface oxygen modification and a specific surface area ≥400 m². 2 / g, oxygen content 5~15wt%.

4. The separation device according to claim 1, characterized in that, The complexing agent further includes one or more components selected from viscosity modifier, catalyst, and low-boiling-point solvent; the viscosity modifier and / or catalyst are added through a first inlet or a second inlet; the low-boiling-point solvent is added through a third inlet.

5. The separation device 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 in the heteroaryl group is N.

6. The separation device 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.

7. The separation device according to claim 4, characterized in that, The viscosity modifier 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 R1OR2, wherein R1 and R2 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 R1(C=O)R2, wherein R1 and R2 are independently selected from C1-C2. 10 Alkyl, C3-C 10 cycloalkyl, C5-C 10 Aryl groups or R1, R2 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.

8. The separation device according to claim 4, characterized in that, The viscosity modifier has a content of 10-30% of the organic amine content; the catalyst has a content of 0.5-5% of the organic amine content; and the low-boiling-point solvent has a content of 5%-25% of the organic amine content.

9. The separation device according to claim 1, characterized in that, The molar ratio of carbon dioxide to organic amine is (0.20~0.80):

1.

10. The separation device according to claim 4 or 8, characterized in that, The catalyst is at least one of hydrochloric acid, sulfuric acid, or carboxylic acid; the carboxylic acid has the general formula R1COOH or R2(COOH)2, wherein R1 is one of hydrogen, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, n-pentyl, isopentyl, or cyclopentyl, and R2 is one of methylene, ethylene, propylene, or methylethylene; the low-boiling solvent is selected from C3-C6 alkanes or C3-C6 cycloalkanes, wherein the C3-C6 alkanes or C3-C6 cycloalkanes are optionally substituted with 1, 2, or 3 halogens, including fluorine, chlorine, or bromine.

11. The separation device according to claim 1, characterized in that, The temperature of the complexing tower is 25-35℃; the temperature of the exchange tower is 10-60℃; and the heating and pyrolysis temperature of the pyrolysis tower is 100-250℃.

12. A method for separating carbon isotopes, characterized in that, The separation method includes: Prepare organic amines, viscosity modifiers, catalysts, and low-boiling-point solvents for later use; Carbon dioxide, organic amines, a catalyst, and a viscosity modifier are introduced into the complexing tower. The carbon dioxide... 12 CO2 complexes with organic amines to form... 12 C-amine complex; The 12 The C-amine complex flows into an exchange tower, and carbon dioxide gas is introduced into the exchange tower. The carbon dioxide contains... 13 CO2 and the above 12 The C-amine complex undergoes an exchange reaction to generate 12 CO2 and 13 C-amine complex; A low-boiling-point solvent is added to the cracking tower, wherein the low-boiling-point solvent and 13 C-amine complexes are mixed and then heated in a cracking tower to decompose into cracking products and... 13 CO2; Impurities in the pyrolysis products are adsorbed by the adsorbent, and organic amines are discharged.

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