A hydroxyalkyl 2,6-dimethylpiperazine carbon capture agent

Abstract

The application discloses a kind of hydroxyalkyl 2,6-dimethylpiperazine carbon capture agent, belongs to carbon capture agent synthesis technical field.The application is with hydroxyalkyl 2,6-dimethylpiperazine as core component, and with corrosion inhibitor and antioxidant mixed homogeneous preparation is obtained.Specifically, the piperazine ring with excellent chemical stability is used as the basic skeleton, by introducing methyl side chain on the six-membered ring, the basicity of the molecule is enhanced and the protonation efficiency of tertiary amine group is enhanced;Further introduce asymmetric hydroxyalkyl, through electron-withdrawing induction effect auxiliary protonation tertiary amine group weakens carbamate stability, realizes the synergistic regulation of efficient absorption and rapid desorption.At the same time, the hydroxyl group in the hydroxyalkyl can effectively improve the water solubility of organic amine, and improve the thermal stability of the molecule.The carbon capture agent has the comprehensive technical advantages of high absorption rate, large absorption capacity, excellent regeneration performance, low desorption energy consumption, and is suitable for low pressure CO2 in flue gas of coal-fired power plant, steel, cement and other industries Efficient energy-saving capture scene.

Description

Technical Field

[0001] This invention relates to the field of carbon capture agent synthesis technology, and in particular to a hydroxyalkyl 2,6-dimethylpiperazine carbon capture agent. Background Technology

[0002] In recent years, the rapid development of global industry has accelerated the consumption of fossil fuels, leading to excessive emissions of greenhouse gases (CO2). Environmental problems caused by carbon emissions are becoming increasingly severe, and reducing CO2 emissions has become an urgent issue. Therefore, developing efficient and low-energy-consumption CO2 capture technologies is of great significance for achieving the dual carbon goals.

[0003] Post-combustion carbon capture technology for high-carbon emission industries has matured and is widely used in industrial settings. Among them, chemical absorption based on regenerable organic amines has become the preferred route for large-scale carbon capture due to its technical reliability and economic feasibility, demonstrating significant application potential. Current industrial practice commonly uses monoamine carbon capture agents, such as primary amines (represented by ethanolamine) and tertiary amines (represented by N-methyldiethanolamine). There is a clear trade-off in performance between the two: primary amines have high absorption rates but high energy consumption during regeneration; tertiary amines have lower regeneration energy consumption but slower reaction kinetics and limited absorption efficiency. In contrast, piperazine, as a secondary amine with a cyclic structure, produces carbamates during its reaction with CO2, which have lower thermal stability and are easier to desorb. This allows for a significant reduction in regeneration energy consumption while maintaining a high absorption rate, effectively overcoming the bottleneck of the "absorption-regeneration" performance trade-off in monoamine carbon capture agents. Based on this advantage, piperazine-based carbon capture agents have become one of the important directions for the research and development of novel high-efficiency carbon capture solvents.

[0004] Chinese patent CN119775226 A discloses a method for synthesizing N-hydroxypropylpiperazine: piperazine undergoes a nucleophilic addition reaction with propylene oxide to generate N-hydroxypropylpiperazine; a homogeneous system is constructed using methanol as a solvent; after the reaction, the product is obtained by desolventizing under reduced pressure, phase separation, washing with water, drying, and column chromatography. This preparation method has simple reaction conditions, low yield and low raw material utilization, and produces a large number of byproducts.

[0005] In summary, given the dual constraints of carbon capture agent performance and energy consumption in the flue gas CO2 capture process, there is an urgent need to develop a novel carbon capture agent that combines high absorption rate, low desorption energy consumption, excellent solubility, and good thermal stability. This direction has become a key task and urgent requirement for promoting the development of carbon capture technology and helping to achieve the goal of "carbon neutrality". Summary of the Invention

[0006] The purpose of this invention is to overcome the deficiencies of existing technologies and provide a hydroxyalkyl 2,6-dimethylpiperazine carbon capture agent.

[0007] This invention is achieved through the following technical solution:

[0008] A hydroxyalkyl 2,6-dimethylpiperazine carbon scavenger, wherein the carbon scavenger is prepared by homogenizing a main absorbent, a corrosion inhibitor and an antioxidant, wherein the main absorbent is a hydroxyalkyl 2,6-dimethylpiperazine having the following structure;

[0009]

[0010] R1 is a C1-C4 alkyl group.

[0011] The method for synthesizing the hydroxyalkyl 2,6-dimethylpiperazine includes the following steps:

[0012] S1: 2,6-Dimethylpiperazine (compound B) and ditert-butyl dicarbonate (compound C) undergo a substitution reaction (single-terminal protection reaction) to synthesize a secondary amine-protected 2,6-dimethylpiperazine intermediate (compound D).

[0013] S2: In a polar solvent, an epoxide (compound E) is added to a secondary amino-protected 2,6-dimethylpiperazine intermediate (compound D) to undergo an addition reaction to synthesize a secondary amino-protected hydroxyalkyl 2,6-dimethylpiperazine intermediate (compound F).

[0014] S3: Add HCl to the hydroxyalkyl 2,6-dimethylpiperazine intermediate (compound F) protected by a secondary amino group to undergo an acid hydrolysis reaction (deprotection reaction) to generate crude hydroxyalkyl 2,6-dimethylpiperazine (compound A);

[0015] S4: The crude hydroxyalkyl 2,6-dimethylpiperazine (compound A) was separated, purified, and refined to obtain the target product. It was then compounded with additives and auxiliaries to obtain a piperazine-based carbon trapping agent.

[0016] Compounds B, C, D, E, and F have the structures shown below:

[0017] .

[0018] The substitution reaction (single-terminal protection reaction) is as follows: under stirring at room temperature, ditert-butyl dicarbonate (compound C) is slowly added to 2,6-dimethylpiperazine (compound B) to undergo a substitution reaction for 2-5 h, generating a secondary amine-protected 2,6-dimethylpiperazine intermediate (compound D).

[0019] The molar ratio of 2,6-dimethylpiperazine to ditert-butyl dicarbonate is 1:2 to 1:5, and the substitution reaction equation is as follows:

[0020] .

[0021] The addition reaction is as follows: under stirring conditions at 30~80℃, a polar solvent is first added to a solution of 2,6-dimethylpiperazine intermediate (compound D) with secondary amino group protection and stirred evenly, and then an epoxide alkane (compound E) is added to undergo a nucleophilic addition reaction for 3~10 h to generate a hydroxyalkyl 2,6-dimethylpiperazine intermediate (compound F) with secondary amino group protection.

[0022] The molar ratio of the epoxide to the secondary amine-protected 2,6-dimethylpiperazine intermediate solution is 1:1 to 2:1, and the addition reaction equation is as follows:

[0023] .

[0024] The polar solvent is one of methanol, ethanol, propanol, dioxane, and tetrahydrofuran.

[0025] The acid hydrolysis reaction is as follows: under stirring at room temperature, HCl is added to a solution of hydroxyalkyl 2,6-dimethylpiperazine intermediate (compound F) protected by a secondary amino group to carry out a hydrolysis reaction, generating crude hydroxyalkyl 2,6-dimethylpiperazine (compound A);

[0026] The molar ratio of HCl to the secondary amine-protected hydroxyalkyl 2,6-dimethylpiperazine intermediate solution is 1:1 to 2:1. The acidolysis reaction equation is as follows:

[0027] .

[0028] The crude hydroxyalkyl 2,6-dimethylpiperazine (compound A) is purified by the following steps: sodium hydroxide solid is added to adjust the pH to 13, and then the mixture is filtered to remove excess sodium hydroxide and residual 2,6-dimethyl impurities; the filtrate is then distilled under reduced pressure to remove water, filtered again, and the filtrate is collected to obtain the target product.

[0029] The corrosion inhibitor is one or more of sulfolane, triethanolamine, tetrasodium adipate, sodium metavanadate, and methionine, with a mass fraction of 1%-30%.

[0030] The antioxidant is one or more of hydroquinone, sodium sulfite, ethylenediaminetetraacetic acid, phenothiazine, and potassium iodide, with a mass fraction of 1%-30%.

[0031] The advantages of this invention are as follows: This invention uses 2,6-dimethylpiperazine and epoxides as raw materials, utilizing the high reactivity of their secondary amines to achieve directional hydroxyalkylation modification. In this invention, the introduction of the methyl side chain enhances the overall basicity of the molecule and improves the protonation efficiency of the tertiary amine group, thereby enhancing the initial absorption capacity of carbon dioxide. The introduction of the asymmetric hydroxyalkyl group, on the one hand, assists the protonated tertiary amine group in weakening the stability of the generated carbamate through an electron-withdrawing inductive effect, thereby achieving synergistic regulation of efficient absorption and rapid desorption; on the other hand, the polar hydroxyl group in the hydroxyalkyl group can effectively improve the water solubility of the organic amine, giving it higher solubility and dispersibility in the aqueous system. Simultaneously, the presence of the hydroxyl group also helps to improve the thermal stability of the molecule during high-temperature desorption. This invention achieves a synergistic effect of electron-donating and steric hindrance, possessing multiple technical effects such as high absorption rate, low desorption energy consumption, and high absorption capacity.

[0032] This invention derives a series of novel and tunable compounds by adjusting the R1 group, which have the combined advantages of high absorption capacity, good stability and low regeneration energy consumption.

[0033] The average yield of this invention is higher than 85%, and the purity of the product is higher than 99%.

[0034] The hydroxypropyl 2,6-dimethylpiperazine carbon trap synthesized according to this invention is liquid at room temperature and pressure. After five cycles at an absorption temperature of 40 °C and a desorption temperature of 120 °C, the organic amine loss is <1%. Under conditions of 40 °C, standard atmospheric pressure, and a CO2 gas concentration of 12.5% ​​(N2 flow rate 87.5 mL / min, CO2 flow rate 12.5 mL / min), the saturated CO2 loading is 0.83 mol / mol. Under conditions of 120 °C, a desorption time of 120 min, and an N2 stripping flow rate of 200 mL / min, the desorption rate is 96.38%, and the desorption amount is 0.80 mol / mol. With similar absorption amounts, the desorption rate is significantly improved compared to traditional organic amine piperazines. Attached Figure Description

[0035] Figure 1 The hydroxypropyl 2,6-dimethylpiperazine in this invention 13 C NMR spectrum;

[0036] Figure 2 The hydroxypropyl 2,6-dimethylpiperazine in this invention 1 H NMR spectrum;

[0037] Figure 3 This is the gas chromatogram of hydroxypropyl 2,6-dimethylpiperazine in this invention. Detailed Implementation

[0038] The technical solution of the present invention will be clearly and completely described below with reference to the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0039] This invention provides a hydroxyalkyl 2,6-dimethylpiperazine carbon scavenger, using 2,6-dimethylpiperazine as a raw material, di-tert-butyl dicarbonate as a secondary amine protecting agent, alkyl epoxides as secondary amine modifiers, and alcohols as solvents. A protecting agent is added to 2,6-dimethylpiperazine to generate a 2,6-dimethylpiperazine intermediate. Further addition of a polar solvent and alkyl epoxides results in an addition reaction to obtain a hydroxyalkyl 2,6-dimethylpiperazine intermediate. Then, HCl solution is added to induce an acid hydrolysis reaction, yielding a crude hydroxyalkyl 2,6-dimethylpiperazine product. This crude product is then purified by separation to obtain the hydroxyalkyl 2,6-dimethylpiperazine. After compounding with corrosion inhibitors and antioxidants, the hydroxyalkyl 2,6-dimethylpiperazine carbon scavenger is obtained.

[0040] Specifically, it is an aqueous solution of hydroxyalkyl 2,6-dimethylpiperazine; the mass fraction of hydroxyalkyl 2,6-dimethylpiperazine in the solution is 5-70%, preferably 20-50%.

[0041] The hydroxyalkyl 2,6-dimethylpiperazine described in this invention is a compound having the following structural formula:

[0042]

[0043] In the compound hydroxyalkyl 2,6-dimethylpiperazine, R1 includes a C1-C4 alkyl group;

[0044] The polar solvent is one of methanol, ethanol, propanol, dioxane, and tetrahydrofuran.

[0045] This invention provides a method for preparing the hydroxyalkyl 2,6-dimethylpiperazine described in the above technical solution, the specific operation steps of which are as follows:

[0046] (1) Substitution reaction: Under stirring at room temperature, di-tert-butyl dicarbonate was slowly added to a solution of 2,6-dimethylpiperazine, and the molar ratio of 2,6-dimethylpiperazine (compound B) to di-tert-butyl dicarbonate (compound C) was controlled at 1:2~5. The reaction was continued for 2 h to obtain a reaction solution containing a 2,6-dimethylpiperazine intermediate protected by a secondary amine group. The specific reaction equation is shown below:

[0047]

[0048] (2) Addition reaction: Under stirring conditions at 30~80℃, a polar solvent was first added to the reaction solution, and then an alkylene oxide (compound E) was added to the solution of the 2,6-dimethylpiperazine intermediate (compound D) to carry out a nucleophilic addition reaction. The molar ratio of alkylene oxide to 2,6-dimethylpiperazine was controlled to be 1~2:1, and the reaction was continued for 5 h to obtain a reaction solution containing Boc-protected hydroxyalkyl 2,6-dimethylpiperazine. The specific reaction equation is shown below:

[0049]

[0050] The polar solvent is one or more of methanol, ethanol, n-propanol, and isopropanol.

[0051] Preferably, the reaction temperature is 30~50℃.

[0052] (3) Acid hydrolysis reaction: The above solution was rotary evaporated and an appropriate amount of methanol was added. Concentrated hydrochloric acid was slowly added dropwise to the solution, and the mixture was stirred at room temperature for 1 h to remove the Boc protecting group on the product; a reaction solution containing hydroxyalkyl 2,6-dimethylpiperazine (compound A) was obtained. The specific reaction equation is shown below:

[0053]

[0054] (4) Separation and purification of the product: The crude product obtained in step (3) is dissolved in a small amount of distilled water, and sodium hydroxide solid is added to adjust the pH to 13. Then, the product is filtered to remove excess sodium hydroxide and residual 2,6-dimethylpiperazine impurities. The filtrate is then subjected to vacuum distillation to remove water, filtered again, and the filtrate is collected to obtain the target product, sterically hindered hydroxyalkyl 2,6-dimethylpiperazine. This method is simple, with a product yield of over 86% and a purity of 99%.

[0055] Preparation of the hydroxyalkyl 2,6-dimethylpiperazine carbon scavenger in this invention:

[0056] At room temperature, hydroxyalkyl 2,6-dimethylpiperazine compounds are used as absorbents. They are homogenized and compounded with corrosion inhibitors and antioxidants in proportions of 5-70%, 0-30 wt%, and 0-30 wt% to obtain hydroxyalkyl 2,6-dimethylpiperazine carbon scavengers.

[0057] The formulations of the absorbent, corrosion inhibitor, and antioxidant are shown in the table below:

[0058]

[0059] Preferred formula:

[0060]

[0061] The corrosion inhibitor is one or more of sulfolane, triethanolamine, tetrasodium adipate, sodium metavanadate, and methionine.

[0062] Preferably, the corrosion inhibitor comprises:

[0063] One or more of sulfolane, tetrasodium adipate, and sodium metavanadate.

[0064] The antioxidant is one or more of hydroquinone, sodium sulfite, ethylenediaminetetraacetic acid, phenothiazine, and potassium iodide.

[0065] Preferably, the antioxidant comprises:

[0066] Hydroquinone, sodium sulfite, and ethylenediaminetetraacetic acid (EDTA) are used in combination with one or more of these substances.

[0067] This invention provides the above-mentioned hydroxyalkyl 2,6-dimethylpiperazine carbon capture agent or a carbon capture agent with the hydroxyalkyl 2,6-dimethylpiperazine compound proposed and synthesized in this invention as the main component, which can be applied to the capture, recovery and utilization of carbon dioxide in industrial flue gas from coal-fired power generation, steel, metallurgy, cement building materials, petrochemical, glass, ultrafine powder and other industries.

[0068] This invention provides a hydroxyalkyl 2,6-dimethylpiperazine carbon trap having the structure shown in Formula A:

[0069]

[0070] In formula A, R1 includes C1 to C4 alkyl groups.

[0071] In this invention, in formula A, R1 = methyl, ethyl, propyl or butyl.

[0072] Example 1

[0073] When the hydroxyalkyl 2,6-dimethylpiperazine carbon trap is compound A and R1 = methyl, specifically hydroxypropyl 2,6-dimethylpiperazine, its synthetic principle is as follows:

[0074]

[0075] At room temperature (25 °C), 3.07 g (approximately 0.027 mol) of 2,6-dimethylpiperazine was added to a 100 mL round-bottom flask. 10.8 g (approximately 0.054 mol) of di-tert-butyl dicarbonate was slowly added dropwise using a constant-pressure funnel, and the reaction was continued for 5 h. Di-tert-butyl dicarbonate was then removed by rotary evaporation. Subsequently, 3.2 g (approximately 0.054 mol) of propylene oxide and an appropriate amount of methanol were added, and the reaction was continued with stirring at room temperature for 48 h. After the reaction was complete, the solution was transferred to a rotary evaporator and distilled under reduced pressure in a water bath at 50-60 °C to remove methanol and unreacted propylene oxide. 50 mL of methanol was added to the residue, followed by the slow addition of 4 mL of concentrated hydrochloric acid. The reaction was stirred at room temperature for 1 h to remove the Boc protecting group. After the reaction was complete, the mixture was filtered to remove the precipitated solid, and the filtrate was collected. The filtrate was then distilled under reduced pressure in an oil bath at 70-80 °C to remove methanol and water. The obtained viscous substance was dissolved in 20 mL of distilled water, and then NaOH solid was added to adjust the pH to 13. The mixture was then filtered again to remove insoluble matter. The filtrate was distilled under reduced pressure in a water bath at 70-80℃ to remove water, yielding the crude product. Finally, the crude product was filtered, and the filtrate was collected to obtain hydroxypropyl 2,6-dimethylpiperazine. The total yield was 87%, and the purity was 99%. The carbon and hydrogen NMR spectra of the product are shown below. Figure 1 and Figure 2 As shown, the gas chromatography characterization results are as follows: Figure 3 As shown.

[0076] The performance evaluation method for hydroxypropyl 2,6-dimethylpiperazine showed that after 5 cycles at an absorption temperature of 40 °C and a desorption temperature of 120 °C, the organic amine loss was <1%. Under the conditions of 40 °C, standard atmospheric pressure, and a CO2 gas concentration of 12.5% ​​(N2 flow rate 87.5 mL / min, CO2 flow rate 12.5 mL / min), the CO2 saturation loading was 0.83 mol / mol. Under the conditions of 120 °C, a desorption time of 120 min, and an N2 stripping flow rate of 200 mL / min, the desorption rate was 96.38%, and the desorption amount was 0.80 mol / mol. With similar absorption amounts, the desorption rate was significantly improved compared to piperazine.

[0077] Example 2

[0078] When the hydroxyalkyl 2,6-dimethylpiperazine carbon trap is compound A and R1 = ethyl, specifically hydroxybutyl 2,6-dimethylpiperazine, the synthesis principle and operation method are basically the same as in Example 1, except that propylene oxide, used as a raw material in Example 1, is replaced with butyl oxide. The overall yield of the obtained product is 86%, and the purity is 99%.

[0079] The performance evaluation of hydroxybutyl 2,6-dimethylpiperazine is as described in Example 1.

[0080] The final measured CO2 saturation absorption capacity of hydroxybutyl-2,6-dimethylpiperazine was 0.84 mol / mol, and the desorption capacity was 0.81 mol / mol.

[0081] Comparative Example 1

[0082] Similar to the performance evaluation procedure for carbon capture agents in Example 1, the absorption-desorption performance was compared with that of commonly used CO2 carbon capture agents such as monoethanolamine and piperazine in the same measurement system. The results are shown in Table 1.

[0083] Table 1 Comparison of carbon capture performance of organic amines

[0084] .

Claims

1. A hydroxyalkyl 2,6-dimethylpiperazine carbon trap, characterized in that, The carbon capture agent is prepared by homogenizing a mixture of a main absorbent, a corrosion inhibitor, and an antioxidant, wherein the main absorbent is a hydroxyalkyl 2,6-dimethylpiperazine having the following structure; Wherein, A represents hydroxyalkyl 2,6-dimethylpiperazine, and R1 is a C1-C4 alkyl group.

2. The hydroxyalkyl 2,6-dimethylpiperazine carbon capture agent of claim 1, wherein, The method for synthesizing the hydroxyalkyl 2,6-dimethylpiperazine includes the following steps: S1: A 2,6-dimethylpiperazine and ditert-butyl dicarbonate were substituted to synthesize a secondary amine-protected 2,6-dimethylpiperazine intermediate. S2: In a polar solvent, an alkylene oxide is added to a secondary amino-protected 2,6-dimethylpiperazine intermediate to undergo an addition reaction, thereby synthesizing a secondary amino-protected hydroxyalkyl 2,6-dimethylpiperazine intermediate. S3: Add HCl to the hydroxyalkyl 2,6-dimethylpiperazine intermediate protected by the secondary amino group to carry out acid hydrolysis reaction to generate crude hydroxyalkyl 2,6-dimethylpiperazine; S4: The crude hydroxyalkyl 2,6-dimethylpiperazine was separated, purified, and refined to obtain the target product, which was then compounded with additives and auxiliaries to obtain a piperazine-based carbon capture agent.

3. The hydroxyalkyl 2,6-dimethylpiperazine carbon capture agent of claim 2, wherein, Compounds B, C, D, E, and F have the structures shown below: Among them, compounds B, C, D, E and F are 2,6-dimethylpiperazine, ditert-butyl dicarbonate, a 2,6-dimethylpiperazine intermediate protected by a secondary amino group, an epoxide alkane, and a hydroxyalkyl 2,6-dimethylpiperazine intermediate protected by a secondary amino group, respectively.

4. The hydroxyalkyl 2,6-dimethylpiperazine carbon capture agent of claim 2, wherein, The substitution reaction is as follows: under stirring at room temperature, ditert-butyl dicarbonate is slowly added to 2,6-dimethylpiperazine to undergo a substitution reaction for 2-5 h, generating a 2,6-dimethylpiperazine intermediate protected by a secondary amino group; The molar ratio of 2,6-dimethylpiperazine to ditert-butyl dicarbonate is 1:2 to 1:5, and the substitution reaction equation is as follows: 。 5. The hydroxyalkyl 2,6-dimethylpiperazine carbon capture agent of claim 2, wherein, The addition reaction is as follows: Under stirring conditions at 30-80℃, a polar solvent is first added to a solution of 2,6-dimethylpiperazine intermediate protected by a secondary amino group and stirred until homogeneous. Then, an alkylene oxide is added to undergo a nucleophilic addition reaction for 3-10 h to generate a hydroxyalkyl 2,6-dimethylpiperazine intermediate protected by a secondary amino group. The molar ratio of the alkylene oxide to the 2,6-dimethylpiperazine intermediate solution protected by a secondary amino group is 1:1 to 2:

1. The addition reaction equation is as follows: 。 6. The hydroxyalkyl 2,6-dimethylpiperazine carbon capture agent according to claim 2 or 5, wherein The polar solvent is one of methanol, ethanol, propanol, dioxane, and tetrahydrofuran.

7. The hydroxyalkyl 2,6-dimethylpiperazine carbon capture agent of claim 2, wherein, The acid hydrolysis reaction is as follows: under stirring at room temperature, HCl is added to a solution of hydroxyalkyl 2,6-dimethylpiperazine intermediate protected by a secondary amino group to carry out a hydrolysis reaction, generating crude hydroxyalkyl 2,6-dimethylpiperazine. The molar ratio of HCl to the secondary amine-protected hydroxyalkyl 2,6-dimethylpiperazine intermediate solution is 1:1 to 2:

1. The acidolysis reaction equation is as follows: 。 8. The hydroxyalkyl 2,6-dimethylpiperazine carbon scavenger according to claim 2, characterized in that, The separation, purification, and refining steps of the crude hydroxyalkyl 2,6-dimethylpiperazine are as follows: sodium hydroxide solid is added to adjust the pH to 13, and then the mixture is filtered to remove excess sodium hydroxide and residual 2,6-dimethyl impurities; the resulting filtrate is subjected to vacuum distillation to remove water, and then filtered again to collect the filtrate and obtain the target product.

9. The hydroxyalkyl 2,6-dimethylpiperazine carbon capture agent of claim 1, wherein, The corrosion inhibitor is one or more of sulfolane, triethanolamine, tetrasodium adipate, sodium metavanadate, and methionine, with a mass fraction of 1%-30%.

10. The hydroxyalkyl 2,6-dimethylpiperazine carbon capture agent of claim 1, wherein, The antioxidant is one or more of hydroquinone, sodium sulfite, ethylenediaminetetraacetic acid, phenothiazine, and potassium iodide, with a mass fraction of 1%-30%.

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