A complexing agent, separation device and separation method for carbon isotope separation

Abstract

This disclosure discloses a complexing agent, separation apparatus, and separation method for carbon isotope separation, belonging to the field of isotope generation technology. The complexing agent comprises an organic amine and a low-boiling-point solvent; the low-boiling-point solvent comprises at least one of small-molecule hydrocarbons and small-molecule haloalkanes; the organic amine is added before the complexation reaction, and the low-boiling-point solvent is added before the cracking reaction. This disclosure, by adding a low-boiling-point solvent to the organic amine, can lower the decomposition temperature of the cracking process, increase the overall yield, reduce organic amine side reactions, and reduce impurities.

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 high temperatures during cracking, low reaction efficiency, numerous impurities generated by side reactions, low overall utilization, 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 the pyrolysis temperature of the pyrolysis process, increase the overall yield, reduce side reactions, thereby reducing impurities and energy consumption, while simultaneously increasing the abundance of carbon isotopes. 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 complexing agent, separation device and separation method for carbon isotope separation.

[0005] In one aspect, this disclosure provides a complexing agent for carbon isotope separation, said complexing agent comprising an organic amine and a low-boiling-point solvent; wherein, The low-boiling-point solvent includes at least one of small molecule hydrocarbons and small molecule haloalkanes; the organic amine is added before the complexation reaction, and the low-boiling-point solvent is added before the cracking reaction.

[0006] The low-boiling solvent is selected from C3-C6 alkanes or C3-C6 cycloalkanes, which are optionally substituted with one, two, or three halogens, including fluorine, chlorine, or bromine; the organic amine is added prior to the complexation reaction, and the low-boiling solvent is added prior to the cracking reaction.

[0007] Optionally, the content of the low-boiling-point solvent is 5%-25% of the organic amine content. For example, it can be 5%, 6%, 7%, 8%, 9%, 10%, 11%, 12%, 13%, 14%, 15%, 16%, 17%, 18%, 19%, 20%, 21%, 22%, 23%, 24%, or 25%.

[0008] Optionally, the low-boiling-point solvent is selected from 1-chloropentane, 1,2-dichloropentane, 1-chlorohexane, dichlorocyclohexane, chlorocyclopentane, and butyrochloroethane.

[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, C5-C8 heteroaryl, C3-C8 cycloalkyl, C5-C8 aryl, or C3-C8 heterocyclic, and R1, R2, and R3 cannot all be hydrogen; the C1-C8 alkyl is optionally substituted by 1, 2, or 3 substituents selected from the following: C1-C3 alkyl, amino, methoxy, halogen, or hydroxyl; the C3-C8 cycloalkane is optionally substituted by 1, 2, or 3 substituents selected from the following: C1-C3 alkyl, amino, methoxy, halogen, or hydroxyl; the C5-C8 heteroaryl is optionally substituted by 1, 2, or 3 substituents selected from the following: C1-C3 alkyl, amino, methoxy, halogen, or hydroxyl; the heteroatom in the heteroaryl or heterocyclic alkane 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, and R1, R2, and R3 cannot all be hydrogen.

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

[0013] Optionally, R1 is hydrogen, R 2、 R3 is selected from hydrogen or C1-C3 alkyl, and R2、 R3 is not simultaneously hydrogen; the C1-C3 alkyl group is optionally substituted with a hydroxyl or methoxy group.

[0014] Optionally, the organic amine is at least one of primary amines, secondary amines, tertiary amines, and 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, and its general formula is R-NH2. The primary amine is selected from ethylamine, n-propylamine, n-butylamine, butanediamine, monoethanolamine, p-phenylenediamine, or isobutanolamine.

[0016] The secondary amine refers to an organic amine formed by replacing two hydrogen atoms in an ammonia molecule with a hydrocarbon group, and its general formula is R2-NH (the two hydrocarbon groups may be the same or different). Optionally, the secondary amine is selected from alkyl straight-chain secondary amines, alkyl branched-chain secondary amines, or cyclic secondary amines; preferably, the secondary amine is selected from diethylamine, diethanolamine, dibutylamine, diisopropanolamine, diisopropylamine, N-isopropylmethylamine, N-methylaniline, piperidine, or pyrrolidine.

[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 can be the same or different), and there are no hydrogen atoms on the nitrogen atom. Examples include triethanolamine (TEA), N-methyldiethanolamine, trimethylamine, triethylamine, or N,N-dimethylaniline.

[0018] The aromatic amine refers to an organic amine 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, or diphenylamine.

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

[0020] 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.

[0021] Optionally, the complexing agent further includes a viscosity modifier, which is any one of a small molecule hydrocarbon, a small molecule ether, or a small molecule ketone. The second component is any one of a small molecule hydrocarbon, a small molecule ether, or a small molecule ketone.

[0022] Optionally, the small molecule hydrocarbon is selected from C5-C64. 10 Alkanes, C5-C 10 Cycloalkanes, C5-C 10 Aromatic hydrocarbons, C5-C 10heteroaromatics 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.

[0023] 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 be optionally 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.

[0024] Optionally, the small molecule ketone is represented by the following general formula R1(C=O)R2, wherein R3 and R4 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 is optionally substituted with a C1-C3 alkyl group; the cycloketone is optionally substituted with a C1-C3 alkyl group; preferably, R3 and R4 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; Further preferably, the small molecule ketone is selected from one of cyclopentanone, cyclohexanone, methylcyclopentanone, methylcyclohexanone, methyl isobutyl ketone, etc.

[0025] 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%.

[0026] Optionally, the complexing agent further includes a catalyst, wherein the catalyst is at least one selected from hydrochloric acid, sulfuric acid, and carboxylic acid.

[0027] 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 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%.

[0029] Optionally, the carboxylic acid is any one of acetic acid, malonic acid, and formic acid.

[0030] Optionally, the catalyst is one or more of hydrochloric acid, sulfuric acid, acetic acid, malonic acid, and formic acid.

[0031] In one aspect, this disclosure provides a carbon isotope separation device, the separation device 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 is provided with a first inlet at the top. In the complexation tower, carbon dioxide... 12 C complexes with organic amines to form 12 C-amine complex; the complexing agent is the complexing agent described above; the organic amine in the complexing agent is added through the first feed inlet, and the low-boiling solvent in the complexing agent is added through the first feed inlet, the exchange tower, or other feed inlets on the cracking tower; 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 C and 12The 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 bottom connected to the third outlet and a fourth outlet at its top for discharging organic amines. In the impurity removal tower, the pyrolysis products form organic amines and impurities.

[0032] In another aspect of this disclosure, a method for separating carbon isotopes is proposed, the method comprising: The complexing agents include organic amines, viscosity modifiers, catalysts, and low-boiling-point solvents for later use; Carbon dioxide and a complexing agent are introduced into the complexing tower. The carbon dioxide contains... 12 C complexes with organic amines to form 12 C-amine complex; the complexing agent is the complexing agent described above; the complex does not contain low-boiling-point solvents.

[0033] 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 C and the above 12 The C-amine complex undergoes an exchange reaction to generate 12 CO2 and 13 C-amine complex; The 13 C-amine complexes and low-boiling solvents are heated and decomposed in a cracking tower into cracking products and... 13 CO2; The pyrolysis products form organic amines and impurities in the impurity removal tower.

[0034] 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, 5:1, 0.6:1, 0.7:1, 0.8:1; preferably, the molar ratio is (0.3~0.6):1.

[0035] 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℃.

[0036] 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℃.

[0037] 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℃.

[0038] This disclosure discloses a complexing agent, separation apparatus, and separation method for carbon isotopes. The complexing agent comprises an organic amine and a low-boiling-point solvent; the low-boiling-point solvent comprises at least one of small-molecule hydrocarbons and small-molecule haloalkanes; the organic amine is added before the complexation reaction, and the low-boiling-point solvent is added before the cracking reaction. This disclosure, by adding a low-boiling-point solvent to the organic amine, can lower the decomposition temperature of the cracking process, increase the overall yield, reduce organic amine side reactions, and reduce impurities. 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] In one aspect of this disclosure, a complexing agent for carbon isotope separation is proposed, the complexing agent comprising an organic amine and a low-boiling-point solvent; wherein the low-boiling-point solvent comprises at least one of a small molecule hydrocarbon and a small molecule halohydrocarbon.

[0042] It should be noted that in this embodiment, the organic amine is added before the complexation reaction, and the low-boiling-point solvent is added before the cracking reaction. For example, the low-boiling-point solvent can be added simultaneously with the organic amine before the complexation reaction, or the low-boiling-point solvent can be added alone during the cracking stage.

[0043] In this embodiment, by adding a low-boiling-point solvent to the organic amine, the decomposition temperature of the pyrolysis process can be reduced, the overall yield can be increased, the side reactions of the organic amine can be reduced, and impurities can be reduced.

[0044] In some preferred embodiments, the small molecule hydrocarbons are preferably C5-C10 chain hydrocarbons, such as C5-C10 straight-chain alkanes and C5-C10 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.

[0045] In other preferred embodiments, the small molecule hydrocarbons are preferably C5-C10 cyclic hydrocarbons, such as cyclohexane, cyclopentane, and methylcyclohexane. Cyclic hydrocarbon molecules have high molecular symmetry and higher polarizability than chain hydrocarbons, resulting in better miscibility with polar organic amines. This avoids stratification at low temperatures or high concentrations, ensuring uniform gas-liquid mass transfer. Cyclic hydrocarbon molecules can form weak interactions with amine complexes through their "π-electron clouds," making it easier for them to insert into the intermolecular hydrogen bond network of amine molecules, thereby reducing the cracking activation energy and ultimately lowering the cracking temperature.

[0046] 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.

[0047] As a further preferred option, the organic amine is selected from diethanolamine, butanediamine, triethanolamine, ethylene glycolamine, N-methylaniline, p-phenylenediamine, piperidine, or pyrrolidine.

[0048] In some other preferred embodiments, the low-boiling-point solvent content is 5%-25% of the organic amine content.

[0049] Furthermore, the complexing agent in this embodiment may also include a viscosity modifier, the content of which is 10-40% of the organic amine content. The viscosity modifier is preferably any one of small molecule hydrocarbons, small molecule ethers, or small molecule ketones. This component can disrupt the hydrogen bonds between amine molecules, and based on the viscosity modifier being a small molecule organic compound, it inserts into the intermolecule gaps of the amine molecules through a molecular dilution effect, physically separating the molecules and further reducing the viscosity of the organic amine liquid. Thus, 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. In other words, the viscosity modifier works synergistically with the low-boiling-point solvent to further reduce the viscosity of the organic amine, improve gas-liquid mass transfer efficiency, and reduce energy consumption.

[0050] It should be understood that the above viscosity modifiers can be added simultaneously with organic amines during the complexation stage, or they can be added separately during the exchange reaction stage; there are no specific limitations on this.

[0051] In some preferred embodiments, the small molecule hydrocarbon is preferably a C5-C10 halogenated hydrocarbon, such as chloroalkanes, including 1-chloropentane, 1,2-dichloropentane, 1-chlorohexane, n-heptane, 1-chlorooctane, etc.; or, for example, halogenated cycloalkanes, including chlorocycloalkanes, dichlorocyclohexane, chlorocyclopentane, etc.

[0052] In some other preferred embodiments, the small molecule ether is preferably a C5-C10 ether, such as diisopropyl ether, methyl tert-butyl ether, ethyl tert-butyl ether, di-n-propyl ether, etc. Of course, other ethers can also be selected, and there is no specific limitation.

[0053] In other preferred embodiments, the small molecule ketone may preferably be a C5-C10 ketone, such as cyclohexanone, methyl isobutyl ketone, cyclopentanone, heptanone, etc.

[0054] 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 complex" is increased, reaction efficiency is improved, isotope abundance is increased, and time is further shortened, the amount of organic amine used is reduced, and energy consumption is reduced.

[0055] It should be understood that the above catalyst can be added simultaneously with the organic amine in the complexation stage, or it can be added separately in the exchange reaction stage, without any specific limitation.

[0056] In some preferred embodiments, the catalyst may preferably be a carboxylic acid, such as acetic acid, malonic acid, formic acid, etc.

[0057] 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.

[0058] In this embodiment, by improving the complexing agent, a low-boiling-point solvent is added to the organic amine, or a catalyst and viscosity modifier are added to achieve a synergistic effect among the four components. The viscosity modifier reduces the viscosity of the amine liquid, improves gas-liquid mass transfer efficiency, and provides a uniform reaction environment for the catalyst. The catalyst accelerates isotope exchange and reduces the cracking load on the low-boiling-point solvent. Here, the viscosity modifier and the catalyst work synergistically for mass transfer and reaction. Based on mass transfer, the catalyst accelerates 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.

[0059] 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 for introducing a complexing agent. This complexing agent is the one described earlier, comprising organic amines and low-boiling-point solvents. 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. 13The 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.

[0060] It should be noted that the organic amine in the complexing agent is added through the first inlet, while the low-boiling-point solvent is not limited to being added through the first inlet. It can be added through other inlets in the cracking tower or the exchange tower. The low-boiling-point solvent can be added throughout the entire process to improve the utilization rate of the recycled materials. Of course, it should be understood that when the low-boiling-point solvent is added to the cracking tower, the cracking tower should be equipped with a separate inlet for the low-boiling-point solvent.

[0061] 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.

[0062] It should be noted that the complexing agent in this embodiment may also include a catalyst, which is at least one of hydrochloric acid, sulfuric acid, and carboxylic acid. This catalyst can also be added during the complexation reaction stage or the exchange reaction stage to accelerate the complexation efficiency of the ¹³C-amine complex. Similarly, when the catalyst is added during the exchange stage, an inlet for the catalyst should be added to the exchange tower. Of course, for the exchange tower, the inlet for the catalyst and the inlet for the viscosity modifier can be set separately or they can be the same; there is no specific limitation on this.

[0063] 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.

[0064] 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.

[0065] In some preferred embodiments, the temperature of the complexation tower is set to 25-40°C. At this temperature, the forward reaction of the complexation stage is promoted, the reverse reaction is suppressed, the decomposition of the complex is avoided, and the ¹²C separation efficiency is improved.

[0066] 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.

[0067] 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, ¹²CCO2 (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, and the equilibrium shifts towards the formation of the ¹³C-amine complex. The large contact area provided by the packing material allows the exchange reaction to proceed fully.

[0068] 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.

[0069] 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.

[0070] 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.

[0071] In some preferred embodiments, 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.

[0072] Furthermore, the impurity removal tower can be a vacuum distillation tower or an azeotropic distillation tower.

[0073] For example, when the impurity removal tower is a vacuum distillation tower, the cracking products are converted into organic amines and impurities through 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 produced by the oxidation, condensation or cross-linking reactions of organic amines, undergo partial depolymerization under vacuum distillation conditions or remain at the bottom of the tower.

[0074] 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.

[0075] In other preferred embodiments, 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.

[0076] 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 organic amines and low-boiling-point solvents. The low-boiling-point solvents include at least one of small-molecule hydrocarbons and small-molecule haloalkanes. 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 12The reaction process of the C-amine complex is as follows: 12 CO2 + RNH2 RNH 12 COOH ( 12 C-amine complex).

[0077] The temperature of the complexation tower in step S210 is set to 25-40℃. At this temperature, the forward reaction is promoted, the reverse reaction (decomposition of the complex) is inhibited, and the ¹²C separation efficiency is improved.

[0078] It should be noted that the low-boiling-point solvent in the complexing agent of this embodiment can be added in step S110 to mix with the organic amine and then added to the complexing tower. Alternatively, the low-boiling-point solvent can be added to the cracking tower in step S230. In other words, the second component can be added before the cracking reaction to reduce the cracking temperature. The order of addition is not specifically limited.

[0079] It should also be noted that the complexing agent in this embodiment may further include a viscosity modifier and a catalyst. The viscosity modifier is any one of small molecule hydrocarbons, small molecule ethers, and small molecule ketones, and 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. The catalyst is at least one of hydrochloric acid, sulfuric acid, and carboxylic acid, and can be added during the complexation reaction stage or the exchange reaction stage to accelerate the complexation efficiency of the ¹³C-amine complex.

[0080] It should be understood that the viscosity modifier and catalyst mentioned above can also be added in step S110 to mix with the organic amine and add to the complexation tower, or the components can be added to the exchange tower in step S220.

[0081] 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. 13 The 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+ RNH13 COOH ( 13 C-amine complex).

[0082] 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.

[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 80-150℃. High temperature promotes the reverse reaction and directionally releases high-purity [product / material]. 13 CO2, avoid 13 C loss.

[0085] S240, the cracking products form organic amines and impurities in the impurity removal tower.

[0086] 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.

[0087] 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.

[0088] 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.

[0089] The separation method disclosed herein is simple. It is based on adding a low-boiling-point solvent to the pyrolysis reaction to reduce the pyrolysis temperature and thus reduce energy consumption. In addition, through synergistic effects with other components, the efficiency of complexation and exchange reactions is further improved, isotope abundance is increased, reaction time is shortened, and energy consumption is reduced.

[0090] 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%.

[0091] 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.

[0092] Where R=(HOCH2CH2)2- 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 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.

[0093] 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 and13 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.

[0094] 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 CO 2， The content of the low-boiling-point solvent is 15% of the organic amine content.

[0095] S4. The pyrolysis products form complexing agents and impurities in the impurity removal tower.

[0096] Specifically, under reduced pressure, the organic amine complexing agent, with its higher boiling point, does not decompose and remains in molecular form, being collected as the high-boiling-point component from the fourth outlet of the reduced-pressure distillation column. Meanwhile, the low-boiling-point solvent... Catalysts, viscosity modifiers, and other byproducts, such as amine polymers produced by the oxidation, condensation, or crosslinking of organic amines, undergo partial depolymerization or remain at the bottom of the distillation column under reduced pressure distillation conditions.

[0097] Detection method: Inductively coupled plasma mass spectrometry After analysis and testing 12 CO2 abundance: 0.02 % 13 The abundance of CO2 was 99.92%. 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.

[0098] 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.

[0099] 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。

[0100] S4. The pyrolysis products form complexing agents 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. Meanwhile, low-boiling-point solvents, catalysts, viscosity modifiers, and other byproducts, such as amine polymers 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] After analysis and testing 12 CO2 abundance 99.92 % 13 The abundance of CO2 was 0.08%.

[0103] 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, 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 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 first component, and the content of the third component is 20% of the first component 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.

[0104] 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.

[0105] 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.

[0106] S4. The pyrolysis products form complexing agents 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 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] After analysis and testing 12 CO2 abundance was 0.12%. 13 CO2 abundance was 99.88%. 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, 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, undergo partial depolymerization under reduced pressure distillation conditions or remain at the bottom of the column.

[0113] After analysis and testing 12 CO2 abundance: 0.06 % 13 The abundance of CO2 was 99.94%. 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 +132 COO - RNH2+ 13 CO2.

[0114] 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.

[0115] 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 13C-amine complex, at this time 12 CO2 is discharged from the exchange tower. 13 The C-amine complex further flows into the cracking tower.

[0116] 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.

[0117] S4. The pyrolysis products form complexing agents and impurities in the impurity removal tower.

[0118] 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. Meanwhile, low-boiling-point solvents, catalysts, viscosity modifiers, and other byproducts, such as amine polymers 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.

[0119] After analysis and testing 12 CO2 abundance: 0.10 % 13 CO2 abundance was 99.90%. 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 -

[0120] 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 diethanolamine 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.

[0121] 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.

[0122] 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.

[0123] S4. The pyrolysis products form complexing agents and impurities in the impurity removal tower.

[0124] 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, undergo partial depolymerization under reduced pressure distillation conditions or remain at the bottom of the column.

[0125] After analysis and testing 12 CO2 abundance: 0.91 % 13 CO2 abundance was 99.09%. 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... 12CO2 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.

[0126] 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.

[0127] 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。

[0128] S4. The pyrolysis products form complexing agents and impurities in the impurity removal tower.

[0129] 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, undergo partial depolymerization under reduced pressure distillation conditions or remain at the bottom of the column.

[0130] After analysis and testing 12 The abundance of CO2 was 0.08%. 13 The abundance of CO2 was 99.92%.

[0131] Example 8 This example demonstrates a method for separating carbon isotopes, the specific process of which is as follows: S1. Carbon dioxide, an organic amine, and a viscosity modifier are introduced into the complexation tower. The organic amine is diethanolamine, and the viscosity modifier is 1-chlorohexane. The viscosity modifier content is 20% of the organic amine content. The molar ratio of carbon dioxide to organic amine is 0.4:1. At 28°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.

[0132] S2, 12The C-amine complex flows into the exchange column, and carbon dioxide gas is introduced into the exchange column. At 46°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.

[0133] 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 CO 2， The content of the low-boiling-point solvent is 15% of the organic amine content.

[0134] S4. The pyrolysis products form complexing agents and impurities in the impurity removal tower.

[0135] 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. Meanwhile, low-boiling-point solvents, catalysts, viscosity modifiers, and other byproducts, such as amine polymers 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.

[0136] Example 9 This example demonstrates a method for separating carbon isotopes, the specific process of which is as follows: S1. Carbon dioxide, an organic amine, and a catalyst are introduced into the complexation tower. The organic amine is diethanolamine, and the catalyst is formic acid. The catalyst content is 3% of the organic amine. The molar ratio of carbon dioxide to organic amine is 0.35:1. At 30°C, the carbon dioxide... 12 CO2 complexes with a complexing agent to form... 12 C-amine complex, at this time 12 The C-amine complex flows into the exchange tower.

[0137] 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.

[0138] 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 CO 2， The content of the low-boiling-point solvent is 15% of the organic amine content.

[0139] S4. The pyrolysis products form complexing agents and impurities in the impurity removal tower.

[0140] 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. Meanwhile, low-boiling-point solvents, catalysts, viscosity modifiers, and other byproducts, such as amine polymers 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.

[0141] Example 10 This example demonstrates a method for separating carbon isotopes, the specific process of which is as follows: S1. Carbon dioxide and an organic amine, specifically diethanolamine, are introduced into the complexation tower. The molar ratio of carbon dioxide to organic amine is 1:1. At 30°C, the carbon dioxide... 12 CO2 complexes with a complexing agent to form... 12 C-amine complex, at this time 12 The C-amine complex flows into the exchange tower.

[0142] 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.

[0143] 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 CO 2， The content of the low-boiling-point solvent is 15% of the organic amine content.

[0144] S4. The pyrolysis products form complexing agents and impurities in the impurity removal tower.

[0145] 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, undergo partial depolymerization under reduced pressure distillation conditions or remain at the bottom of the column.

[0146] 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. Meanwhile, low-boiling-point solvents, catalysts, viscosity modifiers, and other byproducts, such as amine polymers 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.

[0147] Comparative Example 1 This example demonstrates a method for separating carbon isotopes, the specific process of which is as follows: Carbon dioxide and an organic amine, specifically diethanolamine, are introduced into a complexing tower. The molar ratio of carbon dioxide to organic amine is 0.35:1. At 30°C, the carbon dioxide... 12 CO2 complexes with a complexing agent to form... 12 C-amine complex, at this time 12 The C-amine complex flows into the exchange tower.

[0148] 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.

[0149] S3 13 The C-amine complex was decomposed in a cracking column at 105°C into cracking products and... 13 CO2.

[0150] S4. The pyrolysis products form complexing agents and impurities in the impurity removal tower.

[0151] 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, undergo partial depolymerization under reduced pressure distillation conditions or remain at the bottom of the column.

[0152] Synergistic effect of each component of the complexing agent in the test case The complexing agent components of Comparative Examples 1 and 2 are shown in the table below. Other methods and parameters were prepared according to Example 1.

[0153] Conclusion: This disclosure, by combining organic amines with low-boiling-point solvents, catalysts, and viscosity modifiers, can reduce the pyrolysis temperature, decrease amine side reactions, improve regeneration rate, synergistically enhance the mass transfer-reaction matching degree of isotope exchange, shorten the time, and reduce energy consumption.

[0154] 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, by combining organic amines with low-boiling-point solvents, catalysts, and viscosity modifiers, can reduce the pyrolysis temperature, decrease amine side reactions, improve regeneration rate, synergistically enhance the "mass transfer-reaction matching degree" of isotope exchange, shorten the time, and reduce energy consumption.

[0155] Second, the present invention selects organic amines whose amino groups form reversible carbamate complexes with CO2, exhibiting 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.

[0156] 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.

[0157] 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 an organic amine and a low-boiling-point solvent; wherein... The low-boiling solvent is selected from C3-C6 alkanes or C3-C6 cycloalkanes, which are optionally substituted with one, two, or three halogens, including fluorine, chlorine, or bromine; the organic amine is added before the complexation reaction, and the low-boiling solvent is added before the cracking reaction.

2. The complexing agent according to claim 1, characterized in that, The content of the low-boiling-point solvent is 5%-25% of the content of the organic amine.

3. The complexing agent according to claim 1, characterized in that, The low-boiling-point solvent is selected from 1-chloropentane, 1,2-dichloropentane, 1-chlorohexane, dichlorocyclohexane, chlorocyclopentane, and butyrochloroethane.

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 in the heteroaryl group is N, and R1, R2, and R3 are not all hydrogen.

5. The complexing agent according to claim 4, 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 1-4, characterized in that, The complexing agent further 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; the C5-C 10 Alkenes may be optionally substituted with 1, 2 or 3 halogens.

7. The complexing agent according to claim 6, characterized in that, The complexing agent further includes 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.

8. A carbon isotope separation device, characterized in that, The separation device includes: 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 is provided with a first inlet at the top. In the complexation tower, carbon dioxide... 12 CO2 complexes with the organic amine in the complexing agent to form... 12 C-amine complex; the complexing agent is the complexing agent according to any one of claims 1-6; the organic amine in the complexing agent is added through the first inlet, and the low-boiling solvent in the complexing agent is added through the first inlet, other inlets on the exchange tower or cracking tower; 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 bottom connected to the third outlet and a fourth outlet at its top for discharging organic amines. In the impurity removal tower, the pyrolysis products form organic amines and impurities.

9. A carbon isotope separation device, characterized in that, The separation device includes: 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 is provided with a first inlet at the top. In the complexation tower, carbon dioxide... 12 CO2 complexes with the organic amine in the complexing agent to form... 12 C-amine complex; the complexing agent is the complexing agent according to claim 7; the organic amine in the complexing agent is added through the first inlet, the low-boiling solvent in the complexing agent is added through the first inlet, other inlets on the exchange tower or cracking tower, and the catalyst and / or viscosity modifier is added through the first inlet or other inlets on the exchange tower; 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 bottom connected to the third outlet and a fourth outlet at its top for discharging organic amines. In the impurity removal tower, the pyrolysis products form organic amines and impurities.

10. 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, wherein the low-boiling solvent in the complexing agent is added in the cracking tower; 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 C-amine complexes and low-boiling-point solvents are decomposed in a cracking tower at 100-250°C into cracking products and... 13 CO2; The pyrolysis products form organic amines and impurities in a purification tower, the impurities including pyrolysis agents and optionally catalysts and viscosity modifiers.

11. A high abundance 13 C isotopes, characterized by... The high abundance 13 The C isotope is obtained by the separation method of claim 10, wherein 13 CO2 13 The abundance of C isotopes is over 99%.

Images