An organic amine-based carbon dioxide scavenger, its preparation method and application

Abstract

This application discloses a carbon dioxide scavenging agent based on organic amines, its preparation method, and its application. The carbon dioxide scavenging agent comprises the following raw materials in parts by weight: 60-80 parts organic amine, 10-20 parts octanoic acid, 3-7 parts carbon powder, 5-10 parts urea, 10-20 parts polyethylene glycol 400, 1.8-4 parts polyethylene glycol monooleate, 2-4.05 parts choline chloride, and 40-60 parts solvent. This application can improve the carbon dioxide absorption performance and regeneration efficiency of the scavenging agent.

Description

Technical Field

[0001] This application relates to the field of carbon dioxide recovery technology, and in particular to an organic amine-based carbon dioxide capture agent, its preparation method, and its application. Background Technology

[0002] With the booming development of global industry and economy, human demand for energy is constantly rising, which has led to a sharp increase in carbon dioxide emissions from the combustion of fossil fuels, exacerbating the trend of global warming.

[0003] Currently, carbon dioxide capture technologies include absorption, adsorption, membrane separation, and cryogenic distillation. Among these, amine-based capture technology, based on chemical absorption, has become the most mature and widely used technology for capturing carbon dioxide from coal-fired power plants and industrial process tail gas due to its fast absorption rate, high selectivity, and large processing capacity. This type of amine capture technology mainly utilizes the reversible reaction between aqueous solutions of organic amines (such as monoethanolamine, diethanolamine, and methyldiethanolamine) and carbon dioxide. The carbon dioxide-rich solution is then transported to a regeneration tower, where it is heated at 100-120°C to reverse the reaction, releasing high-purity carbon dioxide and simultaneously regenerating lean solution for recycling. However, amine solvents are highly susceptible to chemical and thermal degradation, exhibiting low stability and resulting in poor regeneration efficiency of the absorbent. Summary of the Invention

[0004] To improve the regeneration effect of absorbents, this application provides an organic amine-based carbon dioxide capture agent, its preparation method, and its application.

[0005] In a first aspect, this application provides a carbon dioxide scavenging agent based on organic amines, employing the following technical solution:

[0006] An organic amine-based carbon dioxide scavenger comprises the following raw materials in parts by weight: 60-80 parts organic amine, 10-20 parts octanoic acid, 3-7 parts carbon powder, 5-10 parts urea, 10-20 parts polyethylene glycol 400, 1.8-4 parts polyethylene glycol monooleate, 2-4.05 parts choline chloride, and 40-60 parts solvent.

[0007] By adopting the above technical solutions, this application uses organic amines as the main absorbent to provide basic chemical absorption capacity; octanoic acid and organic amines form an ammonium salt buffer system, which can stabilize the liquid phase pH, inhibit amine oxidation, and provide a proton source during the desorption stage, thereby reducing regeneration energy consumption; carbon powder, as a porous solid carrier, can enrich amine molecules and carbon dioxide through physical adsorption, increase the local reactant concentration, and thus improve the overall carbon dioxide absorption capacity and rate; urea, on the one hand, works synergistically with octanoic acid to regulate the polarity and viscosity of the solution, improving the mass transfer and diffusion of carbon dioxide. On the other hand, the ammonia gas released by the decomposition of urea at the regeneration temperature can undergo proton exchange with the amine system, reducing the thermal degradation of amines at high temperatures; polyethylene glycol 400 and polyethylene glycol monooleate can synergistically reduce the surface tension of the solution, increase the solubility and diffusion coefficient of carbon dioxide in the liquid film, and form an elastic film at the gas-liquid interface to inhibit foaming entrainment and improve mass transfer stability; choline chloride, as a hydrogen bond donor-acceptor bifunctional ionic liquid, can weaken the NH bond strength of amine molecules, accelerate the nucleophilic addition of amines to carbon dioxide, and increase the reaction rate. The above components work together through a combination of physical synergy and chemical promotion to enhance the carbon dioxide absorption performance and regeneration efficiency of the capture agent.

[0008] Optionally, the specific surface area of ​​the toner is greater than 600 m². 2 / g.

[0009] Optionally, the carbon powder is nitrogen-doped carbon powder, and the preparation steps of the nitrogen-doped carbon powder include: mixing urea and water, adding carbon powder, mixing evenly, calcining under nitrogen atmosphere, and grinding to obtain nitrogen-doped carbon powder.

[0010] By adopting the above technical solution, this application uses nitrogen-doped carbon powder, which can enhance the anchoring of organic amine molecules on the carbon powder surface and improve the loading rate by introducing abundant surface alkaline sites. In addition, the introduction of nitrogen can improve the polarity and wettability of the carbon powder surface, making it more uniformly dispersed in the amine liquid system, reducing agglomeration, increasing the gas-liquid-solid three-phase contact interface, and thus improving the mass transfer and reaction efficiency of carbon dioxide.

[0011] Optionally, the organic amine is at least one of 2-(tert-butylamino)ethanol, N-methyldiethanolamine, and 2-amino-2-methyl-1-propanol.

[0012] By employing the above technical solution and selecting organic amines with steric hindrance effects, such as 2-(tert-butylamino)ethanol, N-methyldiethanolamine, and 2-amino-2-methyl-1-propanol, and their combinations, the stability of carbamates can be effectively weakened, making them easier to decompose during the regeneration stage, thereby significantly reducing the energy consumption required for solution regeneration. Simultaneously, the steric hindrance effect reduces, to some extent, the stable byproducts generated from the reaction of amines and carbon dioxide, not only improving the recycling rate of effective amines but also enhancing the stability of the system during long-term operation.

[0013] Optionally, the weight ratio of polyethylene glycol 400 to polyethylene glycol monooleate is (5-9):1.

[0014] By adopting the above technical solution, this application uses a specific ratio of polyethylene glycol 400 and polyethylene glycol monooleate, which ensures that polyethylene glycol monooleate, as a nonionic surfactant, can sufficiently reduce interfacial tension and promote the formation of micelles or microemulsions, thereby significantly increasing the gas-liquid contact area. At the same time, sufficient polyethylene glycol 400, as a water-soluble polymer and co-surfactant, can not only effectively adjust the overall viscosity of the system and prevent excessive foaming or viscosity increase caused by excessive surfactant, but also synergistically stabilize the dispersion structure formed with monooleate, enhancing the elasticity and stability of the liquid film, thereby improving the carbon dioxide capture stability.

[0015] Optionally, the weight ratio of polyethylene glycol monooleate to choline chloride is 1:(1-1.8).

[0016] By employing the above technical solution, this application utilizes a specific ratio of polyethylene glycol monooleate and choline chloride to precisely control the physicochemical microenvironment of the absorbent system, achieving synergistic optimization of surface activity, viscosity control, and reaction kinetics promotion. Choline chloride can form a synergistic solubilizing and stabilizing effect with polyethylene glycol monooleate, and form a highly homogeneous, low-viscosity ionic liquid microenvironment with organic amines, octanoic acid, etc., reducing the reaction energy barrier and avoiding surfactant system failure due to excessively high ionic strength.

[0017] Optionally, the weight ratio of octanoic acid to urea is (1.4-2):1.

[0018] By adopting the above technical solution, this application utilizes a specific ratio of octanoic acid and urea to construct a highly efficient "proton transfer and activation" synergistic system, thereby improving the chemical absorption efficiency of the trap. Specifically, octanoic acid provides a moderately acidic environment and forms an efficient "proton shuttle" buffer pair with organic amines to accelerate reaction kinetics, while preventing excessive acidity from corroding equipment. Urea molecules can fully and uniformly participate in the proton transfer pathway provided by octanoic acid. Its amide groups, through specific interactions with octanoic acid and reaction intermediates, not only further promote the hydration and activation process of carbon dioxide but may also participate in the formation of more easily dissociated intermediates, thus synergistically enhancing the overall absorption capacity and rate at the molecular level.

[0019] Optionally, the solvent is at least one of water, ethanol, and N-methylpyrrolidone.

[0020] By adopting the above technical solution, this application uses water, ethanol, N-methylpyrrolidone, or a combination thereof as solvents, providing a highly adaptable and flexibly adjustable dissolution and reaction medium for the entire absorption system. Water effectively dissolves components such as organic amines and choline chloride, and directly participates in the reaction pathway for carbon dioxide to form bicarbonate; ethanol can adjust the solution polarity, enhance the miscibility of organic components, and to a certain extent lower the freezing point and viscosity of the solution, improving operational performance; N-methylpyrrolidone, as a strongly polar aprotic solvent, has extremely high chemical and thermal stability, which is beneficial for the dissolution of carbon dioxide.

[0021] Optionally, it also includes 6 parts by weight of potassium carbonate and 0.5 parts by weight of copper nitrate.

[0022] By adopting the above technical solution and introducing potassium carbonate and copper nitrate into the absorbent system, a synergistic enhancement of the core absorption performance can be achieved from the perspectives of reaction pathway and system stability. Specifically, potassium carbonate and organic amines can form a highly efficient mixed amine-carbonate absorption system, which directly reacts with carbon dioxide to generate bicarbonate ions, thereby increasing the total carbon dioxide reaction loading capacity and absorption rate. Simultaneously, potassium ions help stabilize reaction intermediates, promote proton transfer, and optimize reaction kinetics. Copper ions in copper nitrate can act as a redox buffer, effectively inhibiting the oxidative degradation of organic amines in an oxygen-rich environment and extending the absorbent's lifespan. Furthermore, copper nitrate can also act as a Lewis acid catalyst, further reducing the energy barrier for carbamate formation and decomposition by weakening C=O bonds or stabilizing transition states, thus helping to reduce regeneration energy consumption.

[0023] Secondly, this application provides a method for preparing a carbon dioxide scavenging agent based on organic amines, using the following technical solution:

[0024] A method for preparing an organic amine-based carbon dioxide scavenger includes the following steps:

[0025] S1. Mix octanoic acid, polyethylene glycol 400 and polyethylene glycol monooleate, heat and stir until homogeneous to obtain a premixed solution;

[0026] S2. Mix organic amine, urea and choline chloride, add solvent, heat and stir until homogeneous to obtain amine phase;

[0027] S3. Add the carbon powder to the premixed liquid, stir evenly, then add the amine phase, stir evenly, and degas under vacuum to obtain the carbon dioxide scavenger.

[0028] Optionally, in step S1, the heating temperature is 50-70℃ and the stirring speed is 300-500 r / min.

[0029] Optionally, in step S2, the heating temperature is 40-60℃ and the stirring speed is 300-500 r / min.

[0030] Optionally, in step S3, the stirring speed is 8000-10000 r / min, and the vacuum degree for vacuum degassing is -0.08~-0.10 MPa.

[0031] Thirdly, this application provides a carbon dioxide capture and absorption method, comprising contacting waste gas containing carbon dioxide with an organic amine-based carbon dioxide capture agent to obtain a carbon dioxide enriched liquid; and heating the carbon dioxide enriched liquid to obtain the carbon dioxide gas.

[0032] In summary, this application includes at least one of the following beneficial technical effects:

[0033] 1. This application uses organic amines as the main absorbent, providing the basic chemical absorption capacity; octanoic acid forms an ammonium salt buffer system with organic amines, which can stabilize the liquid phase pH and inhibit amine oxidation; carbon powder, as a porous solid carrier, can enrich amine molecules and carbon dioxide through physical adsorption, increasing the local reactant concentration, thereby improving the overall carbon dioxide absorption capacity and rate; urea can synergistically regulate the polarity and viscosity of the solution with octanoic acid, improving the mass transfer and diffusion of carbon dioxide and reducing the thermal degradation of amines at high temperatures; polyethylene glycol 400 and polyethylene glycol monooleate can synergistically reduce the surface tension of the solution, increasing the solubility and diffusion coefficient of carbon dioxide in the liquid film; choline chloride, as a hydrogen bond donor-acceptor bifunctional ionic liquid, can weaken the NH bond strength of amine molecules, accelerate the nucleophilic addition of amines to carbon dioxide, and increase the reaction rate. The above components, through a combination of physical synergy and chemical promotion, jointly improve the overall absorption performance, system stability, and regeneration efficiency of the carbon dioxide capture agent;

[0034] 2. This application uses nitrogen-doped carbon powder, which can enhance the anchoring of organic amine molecules on the carbon powder surface and improve the loading rate by introducing abundant surface basic sites. In addition, the introduction of nitrogen can improve the polarity and wettability of the carbon powder surface, making it more uniformly dispersed in the amine liquid system, reducing agglomeration, increasing the gas-liquid-solid three-phase contact interface, and thus improving the mass transfer and reaction efficiency of carbon dioxide;

[0035] 3. This application uses a specific ratio of polyethylene glycol 400 and polyethylene glycol monooleate, which ensures that polyethylene glycol monooleate, as a nonionic surfactant, can sufficiently reduce interfacial tension and promote the formation of micelles or microemulsions, thereby significantly increasing the gas-liquid contact area. At the same time, sufficient polyethylene glycol 400, as a water-soluble polymer and co-surfactant, can not only effectively adjust the overall viscosity of the system and prevent excessive foaming or viscosity increase caused by excessive surfactant, but also synergistically stabilize the dispersion structure formed with monooleate, enhancing the elasticity and stability of the liquid film, thereby improving the carbon dioxide capture stability.

[0036] 4. This application utilizes a specific ratio of octanoic acid and urea to construct a highly efficient "proton transfer and activation" synergistic system, thereby improving the chemical absorption efficiency of the trap. Octanoic acid provides a moderately acidic environment and forms an efficient "proton shuttle" buffer pair with organic amines to accelerate reaction kinetics, while preventing excessive acidity from corroding equipment. Urea molecules can fully and uniformly participate in the proton transfer pathway provided by octanoic acid. Its amide groups, through specific interactions with octanoic acid and reaction intermediates, not only further promote the hydration and activation process of carbon dioxide but may also participate in the formation of more easily dissociated intermediates, thus synergistically enhancing the overall absorption capacity and rate at the molecular level. Detailed Implementation

[0037] The technical solutions 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, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative effort are within the scope of protection of the present invention.

[0038] This application discloses an organic amine-based carbon dioxide scavenger, comprising the following raw materials in parts by weight: 60-80 parts organic amine, 10-20 parts octanoic acid, 3-7 parts carbon powder, 5-10 parts urea, 10-20 parts polyethylene glycol 400, 1.8-4 parts polyethylene glycol monooleate, 2-4.05 parts choline chloride, and 40-60 parts solvent.

[0039] This application discloses a method for preparing a carbon dioxide scavenging agent based on organic amines, comprising the following steps:

[0040] S1. Mix octanoic acid, polyethylene glycol 400 and polyethylene glycol monooleate, heat and stir at 50-70℃ for 10-20 minutes to obtain a premix;

[0041] S2. Mix organic amine, urea and choline chloride, add solvent, heat and stir at 40-60℃ for 20-40 min to obtain amine phase;

[0042] S3. Add the carbon powder to the premixed solution and stir at 8000-10000 r / min for 10-20 min. Then add the amine phase and stir evenly at 8000-10000 r / min for 5-10 min. Degas under vacuum at -0.08~-0.10 MPa for 20-40 min to obtain the carbon dioxide scavenger.

[0043] This application discloses a carbon dioxide capture and absorption method, which includes contacting waste gas containing carbon dioxide with a carbon dioxide capture agent to obtain a carbon dioxide enriched liquid; and heating the carbon dioxide enriched liquid at 80-110℃ for 1-2 hours to obtain carbon dioxide gas.

[0044] All raw materials used in the embodiments of this application are commercially available, wherein:

[0045] 2-(tert-Butylamino)ethanol, Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0046] N-Methyldiethanolamine, Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0047] 2-Amino-2-methyl-1-propanol, Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0048] Bitterness, Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0049] Polyethylene glycol 400, Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0050] Polyethylene glycol monooleate, Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0051] Urea, Shanghai Aladdin Biochemical Technology Co., Ltd.;

[0052] Choline chloride, Wuhan Kemike Biomedical Technology Co., Ltd.;

[0053] Powdered activated carbon, Chongqing Saihongqiu Technology Co., Ltd. Specific Implementation

[0054] Preparation Example 1

[0055] Preparation of nitrogen-doped carbon powder: Mix 10g of urea and 10mL of water, add 10g of carbon powder, mix evenly, calcine at 800℃ for 2h under nitrogen atmosphere, grind, and pass through a 100-mesh sieve to obtain nitrogen-doped carbon powder. Example 1

[0056] Mix 15g of octanoic acid, 15g of polyethylene glycol 400, and 3g of polyethylene glycol monooleate, and heat and stir at 60℃ for 15min to obtain a premix. Mix 70g of 2-(tert-butylamino)ethanol, 7.5g of urea, and 3g of choline chloride, add 50mL of water, and heat and stir at 50℃ for 30min to obtain an amine phase. Add 5g of powdered activated carbon to the premix, stir at 8000r / min for 15min, then add the amine phase, stir evenly at 8000r / min for 10min, and degas under vacuum at -0.09MPa for 30min to obtain a carbon dioxide scavenging agent. Example 2

[0057] Mix 10g of octanoic acid, 10g of polyethylene glycol 400, and 2g of polyethylene glycol monooleate, and heat and stir at 50°C for 20 minutes to obtain a premix. Mix 60g of N-methyldiethanolamine, 5g of urea, and 2g of choline chloride, add 20mL of ethanol and 20mL of water, and heat and stir at 40°C for 40 minutes to obtain an amine phase. Add 3g of powdered activated carbon to the premix, stir at 10000r / min for 10 minutes, then add the amine phase, stir evenly at 10000r / min for 5 minutes, and degas under vacuum at -0.08MPa for 40 minutes to obtain a carbon dioxide scavenging agent. Example 3

[0058] Mix 20g of octanoic acid, 20g of polyethylene glycol 400, and 4g of polyethylene glycol monooleate, and heat and stir at 70℃ for 10min to obtain a premix. Mix 80g of 2-amino-2-methyl-1-propanol, 10g of urea, and 4g of choline chloride, add 60mL of N-methylpyrrolidone, and heat and stir at 60℃ for 20min to obtain an amine phase. Add 7g of powdered activated carbon to the premix, stir at 8000r / min for 20min, then add the amine phase, stir evenly at 8000r / min for 5min, and degas under vacuum at -0.10MPa for 20min to obtain a carbon dioxide scavenger.

[0059] The carbon dioxide capture agents obtained in Examples 1-3 were tested for carbon dioxide absorption rate, carbon dioxide desorption rate, and regeneration efficiency. The carbon dioxide absorption rate and desorption rate were tested as follows: 25 mL of the carbon dioxide capture agent was added to an absorption bottle and heated in a water bath at 40°C, while simulated waste gas was introduced at a flow rate of 50 mL / min. The simulated waste gas contained 83 vol% nitrogen, 12 vol% carbon dioxide, and 5 vol% water vapor. The carbon dioxide absorption rate was calculated by the amount of gas introduced and the amount of gas discharged. Then, the carbon dioxide-absorbed capture agent was heated to 80°C for desorption for 60 min, and the carbon dioxide desorption rate was calculated by the amount of gas discharged. The regeneration efficiency was tested as follows: carbon dioxide absorption and desorption were performed according to the same methods. The regenerated capture agent was then subjected to the same carbon dioxide absorption-desorption steps as described above, and the regeneration efficiency of the carbon dioxide capture agent after 10 cycles was calculated.

[0060] The test results of Examples 1-3 obtained according to the above test methods are shown in Table 1:

[0061] Table 1 Performance testing of carbon dioxide scavengers in Examples 1-3

[0062]

[0063] As shown in Examples 1-3 and Table 1, the carbon dioxide scavenging agents of Examples 1-3 have a carbon dioxide absorption rate of over 80%, a carbon dioxide desorption rate of over 77%, and a regeneration efficiency of over 79%. This indicates that the carbon dioxide scavenging agent of this application can improve the absorption performance and regeneration effect of carbon dioxide.

[0064] Comparative Example 1

[0065] The difference between this comparative example and Example 1 is that the polyethylene glycol monooleate in Example 1 is replaced by polyethylene glycol 400.

[0066] Comparative Example 2

[0067] The difference between this comparative example and Example 1 is that in this comparative example, polyethylene glycol 400 in Example 1 is replaced by polyethylene glycol monooleate.

[0068] The carbon dioxide capture agents obtained in Example 1 and Comparative Examples 1-2 were tested for carbon dioxide absorption rate, desorption rate, and regeneration efficiency. The test results are shown in Table 2.

[0069] Table 2 Performance testing of carbon dioxide scavengers in Examples 1 and 1-2

[0070]

[0071] As shown in Example 1, Comparative Examples 1-2, and Table 2, the carbon dioxide capture agent in Example 1 exhibits a carbon dioxide absorption rate of 83%, a carbon dioxide desorption rate of 79%, and a regeneration efficiency of 81%, significantly higher than that in Comparative Examples 1-2. This indicates that polyethylene glycol 400 and polyethylene glycol monooleate ester can synergistically reduce the surface tension of the solution, increase the solubility and diffusion coefficient of carbon dioxide in the liquid film, and form an elastic film at the gas-liquid interface, thereby improving mass transfer stability. While polyethylene glycol 400 alone can increase the viscosity of the system, it is difficult to effectively reduce the gas-liquid interfacial tension, leading to a decrease in carbon dioxide mass transfer efficiency; while polyethylene glycol monooleate ester alone can improve the structural stability of the system, it is prone to causing excessive foaming or interfacial film instability, affecting regeneration performance. Example 4

[0072] The difference between this embodiment and Example 1 is that in this embodiment, the powdered activated carbon in Example 1 is replaced by nitrogen-doped carbon powder obtained in Preparation Example 1.

[0073] Examples 5-6

[0074] Based on Example 4, except for the weight ratio of polyethylene glycol 400 and polyethylene glycol monooleate, the total weight of polyethylene glycol 400 and polyethylene glycol monooleate remained unchanged, and the other components and preparation methods were the same as in Example 4. Example 5

[0075] The difference between this embodiment and embodiment 4 is that the weight ratio of polyethylene glycol 400 and polyethylene glycol monooleate in this embodiment is 7:1. Specifically, the weight of polyethylene glycol 400 is 15.75g and the weight of polyethylene glycol monooleate is 2.25g. Example 6

[0076] The difference between this embodiment and embodiment 4 is that the weight ratio of polyethylene glycol 400 and polyethylene glycol monooleate in this embodiment is 9:1. Specifically, the weight of polyethylene glycol 400 is 18.2g and the weight of polyethylene glycol monooleate is 1.8g.

[0077] The carbon dioxide capture agents obtained in Examples 1 and 4-6 were tested for carbon dioxide absorption rate, desorption rate, and regeneration efficiency. The test results are shown in Table 3.

[0078] Table 3 Performance testing of carbon dioxide scavengers in Examples 1 and 4-6

[0079]

[0080] As shown in Examples 1 and 4 and Table 3, the carbon dioxide capture agent of Example 4 has a carbon dioxide absorption rate of 86%, a carbon dioxide desorption rate of 82%, and a regeneration efficiency of 84%, which are significantly higher than those of Example 1. This indicates that the nitrogen-doped carbon powder used in this application can enhance the amine molecule loading and mass transfer efficiency, thereby improving the absorption, desorption, and cycle stability of carbon dioxide.

[0081] As shown in Examples 4-6 and Table 3, the carbon dioxide capture agent of Example 5 has a carbon dioxide absorption rate of 88%, a carbon dioxide desorption rate of 84%, and a regeneration efficiency of 85%, which are significantly higher than those of Example 4. This indicates that the present application uses a specific ratio of polyethylene glycol 400 and polyethylene glycol monooleate, which can increase the gas-liquid contact area while enhancing the elasticity and stability of the liquid film, thereby improving the carbon dioxide absorption performance.

[0082] Examples 7-8

[0083] Based on Example 5, except for the weight ratio of polyethylene glycol monooleate and choline chloride, the other components and preparation methods are the same as in Example 5. Example 7

[0084] The difference between this embodiment and embodiment 5 is that the weight ratio of polyethylene glycol monooleate and choline chloride in this embodiment is 1:1.7. Specifically, the weight of polyethylene glycol monooleate is 2.25g and the weight of choline chloride is 3.825g. Example 8

[0085] The difference between this embodiment and embodiment 5 is that the weight ratio of polyethylene glycol monooleate and choline chloride in this embodiment is 1:1.8. Specifically, the weight of polyethylene glycol monooleate is 2.25g and the weight of choline chloride is 4.05g.

[0086] The carbon dioxide capture agents obtained in Examples 5 and 7-8 were tested for carbon dioxide absorption rate, desorption rate, and regeneration efficiency. The test results are shown in Table 4.

[0087] Table 4 Performance testing of carbon dioxide scavengers in Examples 5 and 7-8

[0088]

[0089] As shown in Examples 5, 7-8, and Table 4, the carbon dioxide capture agent of Example 7 exhibits a carbon dioxide absorption rate of 90%, a carbon dioxide desorption rate of 86%, and a regeneration efficiency of 87%, significantly higher than that of Examples 5 and 8. This indicates that the specific ratio of polyethylene glycol monooleate and choline chloride in this application allows for precise control of the physicochemical microenvironment of the absorbent system, achieving synergistic optimization of surface activity, viscosity control, and reaction kinetics promotion, thereby further enhancing the absorption, desorption, and cycling stability of carbon dioxide. Excessive proportions of choline chloride and polyethylene glycol monooleate will affect the surface activity and stability of the ionic liquid microenvironment, thus impacting the carbon dioxide absorption efficiency.

[0090] Examples 9-10

[0091] Based on Example 7, except for the weight ratio of octanoic acid and urea, the other components and preparation methods are the same as in Example 7, and the total weight of octanoic acid and urea remains unchanged. Example 9

[0092] The difference between this embodiment and embodiment 7 is that the weight ratio of caprylic acid to urea in this embodiment is 1.5:1. Specifically, the weight of caprylic acid is 13.5g and the weight of urea is 9g. Example 10

[0093] The difference between this embodiment and embodiment 7 is that the weight ratio of caprylic acid to urea in this embodiment is 1.4:1. Specifically, the weight of caprylic acid is 13.125g and the weight of urea is 9.375g. Example 11

[0094] 13.5g of octanoic acid, 15.75g of polyethylene glycol 400, and 2.25g of polyethylene glycol monooleate were mixed and heated at 60℃ for 15min to obtain a premix. 70g of 2-(tert-butylamino)ethanol, 9g of urea, 3.825g of choline chloride, 6g of potassium carbonate, and 0.5g of copper nitrate were mixed and 50mL of water was added. The mixture was heated at 50℃ for 30min to obtain an amine phase. 5g of powdered activated carbon was added to the premix and stirred at 8000r / min for 15min. Then, the amine phase was added and stirred at 8000r / min for 10min until homogeneous. The mixture was then degassed under vacuum at -0.09MPa for 30min to obtain a carbon dioxide scavenging agent.

[0095] The carbon dioxide capture agents obtained in Examples 7 and 9-11 were tested for carbon dioxide absorption rate, desorption rate, and regeneration efficiency. The test results are shown in Table 5.

[0096] Table 5 Performance testing of carbon dioxide capture agents in Examples 7 and 9-11

[0097]

[0098] As shown in Examples 7, 9-10, and Table 5, the carbon dioxide capture agent of Example 9 exhibits a carbon dioxide absorption rate of 91%, a carbon dioxide desorption rate of 87%, and a regeneration efficiency of 88%, significantly higher than that of Examples 7 and 10. This indicates that the present application utilizes a specific ratio of octanoic acid and urea to construct a highly efficient "proton transfer and activation" synergistic system. While providing a suitable acidic environment and accelerating reaction kinetics, it effectively inhibits the thermal degradation of amines, thereby further improving the carbon dioxide absorption capacity, desorption efficiency, and cycle stability. A low proportion of octanoic acid will affect the proton supply efficiency, thus impacting reaction kinetics; a low proportion of urea will affect the absorption rate and capacity.

[0099] As shown in Examples 9, 11, and Table 5, the carbon dioxide capture agent of Example 11 has a carbon dioxide absorption rate of 93%, a carbon dioxide desorption rate of 89%, and a regeneration efficiency of 90%, which is significantly better than that of Example 9. This indicates that by constructing a mixed amine-carbonate absorption system, this application can further synergistically improve the carbon dioxide absorption capacity and regeneration efficiency of the capture agent.

[0100] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A carbon dioxide scavenging agent based on organic amines, characterized in that, The raw materials include the following parts by weight: 60-80 parts organic amine, 10-20 parts octanoic acid, 3-7 parts carbon powder, 5-10 parts urea, 10-20 parts polyethylene glycol 400, 1.8-4 parts polyethylene glycol monooleate, 2-4.05 parts choline chloride, and 40-60 parts solvent.

2. The organic amine-based carbon dioxide scavenger according to claim 1, characterized in that, The carbon powder is nitrogen-doped carbon powder. The preparation steps of the nitrogen-doped carbon powder include: mixing urea and water, adding carbon powder, mixing evenly, calcining under nitrogen atmosphere, and grinding to obtain nitrogen-doped carbon powder.

3. The organic amine-based carbon dioxide scavenger according to claim 1, characterized in that, The organic amine is at least one of 2-(tert-butylamino)ethanol, N-methyldiethanolamine, and 2-amino-2-methyl-1-propanol.

4. The organic amine-based carbon dioxide scavenger according to claim 1, characterized in that, The weight ratio of polyethylene glycol 400 to polyethylene glycol monooleate is (5-9):

1.

5. The organic amine-based carbon dioxide scavenger according to claim 4, characterized in that, The weight ratio of polyethylene glycol monooleate to choline chloride is 1:(1-1.8).

6. The organic amine-based carbon dioxide scavenger according to claim 1, characterized in that, The weight ratio of caprylic acid to urea is (1.4-2):

1.

7. The organic amine-based carbon dioxide scavenger according to claim 1, characterized in that, The solvent is at least one of water, ethanol, and N-methylpyrrolidone.

8. The organic amine-based carbon dioxide scavenger according to claim 1, characterized in that, It also includes 6 parts by weight of potassium carbonate and 0.5 parts by weight of copper nitrate.

9. A method for preparing the organic amine-based carbon dioxide scavenger according to claim 1, characterized in that, Includes the following steps: S1. Mix octanoic acid, polyethylene glycol 400 and polyethylene glycol monooleate, heat and stir until homogeneous to obtain a premixed solution; S2. Mix organic amine, urea and choline chloride, add solvent, heat and stir until homogeneous to obtain amine phase; S3. Add the carbon powder to the premixed liquid, stir evenly, then add the amine phase, stir evenly, and degas under vacuum to obtain the carbon dioxide scavenger.

10. A method for capturing and absorbing carbon dioxide, characterized in that, The method includes contacting waste gas containing carbon dioxide with the organic amine-based carbon dioxide capture agent according to any one of claims 1-8 to obtain a carbon dioxide enriched liquid; and heating the carbon dioxide enriched liquid to obtain the carbon dioxide gas.

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