High-efficiency low-energy-consumption carbon capture absorbent and preparation method thereof

Abstract

The invention belongs to the technical field of carbon capture, and particularly relates to a high-efficiency low-energy-consumption carbon capture absorbent and a preparation method thereof. The preparation method comprises the following steps: protecting aminopyridine by using di-tert-butyl dicarbonate to obtain protected aminopyridine, then carrying out Mannich reaction on the protected aminopyridine, 2, 2, 3, 3, 4, 4, 5, 5-octafluorovaleraldehyde and 3-aminopropyltrimethoxysilane under the catalysis of acetic acid, and removing amino protection to generate an active agent; and grafting the active agent with the carrier through a silane chain segment to obtain the high-efficiency low-energy-consumption carbon capture absorbent. According to the invention, the adsorption capacity and the regeneration efficiency are synchronously improved, and the stability and the water vapor interference resistance of the adsorbent are also enhanced.

Description

Technical Field

[0001] This invention belongs to the field of carbon capture technology, specifically relating to a high-efficiency, low-energy carbon capture and absorbent and its preparation method. Background Technology

[0002] With increasing global attention to climate change, carbon dioxide (CO2) capture, utilization, and storage (CVS) technologies have become a key pathway to achieving carbon neutrality. Among these, adsorption-based carbon capture technologies using solid adsorbents have shown broad application prospects due to their advantages such as low energy consumption and minimal equipment corrosion. Of various solid adsorbents, supported amine adsorbents with amino compounds as active components have been extensively studied due to their high selectivity for CO2 adsorption.

[0003] Traditional immobilized amine adsorbents typically load polyamines onto porous supports via physical impregnation or chemical grafting. However, a trade-off always exists between adsorption capacity and regeneration energy consumption. The carbamates formed from the reaction of amines with CO2 are overly stable, requiring desorption at high temperatures, resulting in significant energy consumption. Increasing the amine loading to improve adsorption capacity often exacerbates amine molecule aggregation within the pores, blocking CO2 diffusion channels and affecting mass transfer efficiency. Furthermore, the excessive density of active sites further enhances the stability of the adsorbed products, increasing regeneration energy consumption and creating a vicious cycle. In addition, during repeated adsorption-regeneration cycles, amine surfactants are prone to volatilization or degradation, leading to performance degradation and decreased mechanical strength. Water vapor in the environment competes with CO2 for amine active sites and condenses within hydrophilic amines and pores, occupying adsorption space and causing dissolution of active components, resulting in a significant decrease in capture capacity under humid conditions.

[0004] To address the aforementioned issues, existing technologies have attempted some improvements, such as introducing sterically hindered amines or developing novel porous supports. However, these methods often only solve one specific problem—capacity, energy consumption, or stability—and fail to achieve synergistic optimization. Therefore, there is an urgent need in this field to develop a novel, highly efficient, and low-energy-consumption carbon capture and absorbent that simultaneously possesses high adsorption capacity, low regeneration energy consumption, excellent structural stability, and strong resistance to water vapor interference, thereby overcoming the combined shortcomings of existing technologies. Summary of the Invention

[0005] The purpose of this invention is to provide a highly efficient and low-energy carbon capture and absorbent and its preparation method, so as to solve the problems mentioned in the background art.

[0006] Therefore, a first aspect of the present invention provides a method for preparing a highly efficient and low-energy-consumption carbon capture and absorbent, the method comprising: (1) Reaction of aminopyridine with di-tert-butyl dicarbonate yields protected aminopyridine; (2) The protected aminopyridine was reacted with 2,2,3,3,4,4,5,5-octafluoropentanal and 3-aminopropyltrimethoxysilane in a Mannich reaction to obtain the activator; (3) The active agent is grafted onto the solid support to obtain the high-efficiency and low-energy carbon capture adsorbent.

[0007] As a preferred embodiment, the preparation method of the above-mentioned high-efficiency, low-energy-consumption carbon capture and absorbent includes: (1) Add aminopyridine to the first solvent, then add di-tert-butyl dicarbonate, react, after the reaction is complete, extract, collect the organic phase and remove the solvent to obtain protected aminopyridine; (2) Add protected aminopyridine, 2,2,3,3,4,4,5,5-octafluoropentanal, 3-aminopropyltrimethoxysilane and weak acid catalyst to the second solvent, react, remove the solvent from the reaction solution after the reaction is completed, and then remove the tert-butyloxycarbonyl group to obtain the activator. (3) Disperse the activator and solid support in a third solvent to graft the activator onto the solid support, then filter and collect the solid, optionally wash and optionally dry it to obtain the high-efficiency and low-energy carbon capture adsorbent.

[0008] As a preferred embodiment, in the above-mentioned method for preparing a high-efficiency, low-energy carbon capture and absorbent, in step (1), the first solvent is tetrahydrofuran. Tetrahydrofuran is a polar aprotic solvent with good solubility, especially for organic amines (such as aminopyridine) and esters (such as di-tert-butyl dicarbonate), which helps the reactants to fully contact and improves the reaction efficiency. Tetrahydrofuran has a moderate boiling point, which facilitates subsequent removal by methods such as rotary evaporation under reduced pressure, without leaving too many impurities. Compared with other common organic solvents (such as dichloromethane, acetonitrile, etc.), tetrahydrofuran ensures the solubility of the reactants at room temperature and avoids the occurrence of side reactions, which is beneficial for controlling the selectivity and yield of the reaction.

[0009] As a preferred embodiment, in the above-mentioned method for preparing a high-efficiency, low-energy carbon capture and absorbent, the extractant in step (1) is ethyl acetate. Ethyl acetate is a commonly used organic extractant, immiscible with water, and can effectively extract protected aminopyridines from the organic phase while clearly separating from the aqueous layer, making the operation simple. It has good selectivity, which can minimize the entry of impurities into the organic phase and help improve the purity of subsequent products. Ethyl acetate has good volatility and is compatible with the subsequent vacuum rotary evaporation step, which is beneficial for efficient solvent removal.

[0010] As a preferred embodiment, in the above-mentioned method for preparing a high-efficiency, low-energy carbon capture and absorbent, the solvent removal method in step (1) is vacuum rotary evaporation. Vacuum rotary evaporation is a mild concentration and solvent removal method commonly used in laboratories and industries. It can efficiently remove low-boiling-point solvents such as tetrahydrofuran and ethyl acetate at relatively low temperatures, avoiding the decomposition or side reactions of protected aminopyridines caused by high temperatures. This operation method has strong controllability and can effectively preserve the structural integrity of the target product, improving yield and purity.

[0011] As a preferred embodiment, in the above-mentioned method for preparing a high-efficiency, low-energy carbon capture and absorbent, in step (2), the second solvent is ethanol. Ethanol is a polar protic solvent with good hydrogen bonding ability, which is beneficial for promoting proton transfer and intermediate formation among the reactants (protected aminopyridine, 2,2,3,3,4,4,5,5-octafluoropentanal, 3-aminopropyltrimethoxysilane) in the Mannich reaction. Ethanol has good compatibility with acetic acid (a weak acid catalyst), which is conducive to the catalytic reaction. At the same time, its low toxicity and easy recovery characteristics are suitable for green chemical processes. Ethanol has a moderate boiling point and can be efficiently removed by vacuum distillation, which facilitates the separation and purification of subsequent products.

[0012] As a preferred embodiment, in the above-mentioned method for preparing a high-efficiency, low-energy carbon capture and absorbent, the weak acid catalyst in step (2) is acetic acid. Acetic acid, as a typical weak organic acid, can provide a suitable acidic environment in the Mannich reaction, catalyzing the condensation and rearrangement reactions between carbonyl compounds (such as octafluoropentanal) and amines and amine alkylsilanes without excessively promoting side reactions. Its moderate acidity and mild reaction conditions help control the selectivity of the reaction and avoid potential structural damage to the active agent or an increase in byproducts under strong acid conditions. Acetic acid is safe, low-cost, and volatile, making it well-matched with the subsequent vacuum distillation removal process.

[0013] As a preferred embodiment, in the above-mentioned method for preparing a high-efficiency, low-energy carbon capture and absorbent, the solvent removal method in step (2) is vacuum distillation. Similar to step (1), removing solvents such as ethanol by vacuum distillation can achieve high-efficiency concentration under mild conditions, avoiding the deactivation or degradation of the target active agent at high temperatures. This process is green and environmentally friendly, easy to scale up industrially, and ensures the high purity and structural integrity of the product.

[0014] As a preferred embodiment, in the above-mentioned method for preparing a high-efficiency, low-energy carbon capture and absorbent, the third solvent in step (3) is toluene. Toluene is a non-polar aromatic hydrocarbon solvent with excellent solubility for silanization reactions and organosilicon compounds, which helps the silane segments in the active agent to form effective covalent bonds with the surface of the solid support. Toluene has a high boiling point and is suitable for use at grafting reaction temperatures of 70-80℃, while the stability of the reaction system can be maintained by conventional heating. It is chemically inert and does not easily react with reactants, which helps to control the selectivity and efficiency of the grafting reaction.

[0015] As a preferred embodiment, in the above-mentioned method for preparing a high-efficiency, low-energy carbon capture and absorbent, step (2) involves removing the tert-butyloxycarbonyl group from the reaction solution after removing the solvent. This step includes: placing the solution in dichloromethane at 0-5°C, then adding trifluoroacetic acid, stirring for 1-3 hours, and removing the solvent after the reaction is complete. The removal of the tert-butyloxycarbonyl group usually needs to be carried out under acidic conditions. Trifluoroacetic acid is a strong organic acid that can efficiently break the tert-butyloxycarbonyl group, releasing free amino groups, while the reaction conditions are relatively controllable. To avoid damage to sensitive structures (such as perfluoroalkyl and silane segments) in the active agent caused by high temperatures, the reaction is carried out at low temperatures of 0-5°C. Usually, the reaction system is first dissolved in dichloromethane, and then trifluoroacetic acid is added for a short-time reaction. This operation ensures the high efficiency and selectivity of deprotection, while maximizing the protection of the integrity of the overall structure of the active agent, providing a highly active intermediate for subsequent grafting.

[0016] As a preferred embodiment, in the above-mentioned method for preparing a high-efficiency, low-energy carbon capture and absorbent, the aminopyridine is at least one of 2-aminopyridine, 3-aminopyridine, and 4-aminopyridine. While aminopyridines at different positions exhibit slight differences in steric hindrance and electronic effects, they all possess the ability to react with di-tert-butyl dicarbonate to form a stable protecting group, and simultaneously provide active amino sites in the Mannich reaction for subsequent binding with CO2. This flexibility allows for the selection of aminopyridines from different sources or with varying purities based on actual reaction performance or cost considerations, increasing the adaptability of the process and the availability of raw materials.

[0017] As a preferred embodiment, in the above-mentioned method for preparing a high-efficiency, low-energy-consumption carbon capture and absorbent, the solid support is at least one of mesoporous silica, activated carbon, and graphene. Mesoporous silica possesses a high specific surface area and an ordered pore structure, which facilitates the uniform dispersion and fixation of the active agent, improving adsorption performance and stability. Activated carbon's abundant surface functional groups and high porosity help enhance the synergistic effect of physical and chemical adsorption of CO2. Graphene has an ultra-high specific surface area and excellent electronic conductivity, making it suitable as a high-performance support to improve the structural stability and reactivity of the adsorbent. This diversity allows the present invention to flexibly select the support type according to the target application scenario, optimizing the overall adsorbent performance.

[0018] As a preferred embodiment, in the above-mentioned method for preparing a high-efficiency, low-energy carbon capture and absorbent, in step (1), the mass ratio of aminopyridine to di-tert-butyl dicarbonate is 85-90:153-162. This ratio ensures that the aminopyridine is adequately protected, avoids waste or byproducts caused by excessive protective agent, and at the same time ensures complete reaction and improves yield.

[0019] As a preferred embodiment, in the above-mentioned method for preparing a high-efficiency, low-energy carbon capture and absorbent, in step (2), the mass ratio of protected aminopyridine, 2,2,3,3,4,4,5,5-octafluoropentanal, and 3-aminopropyltrimethoxysilane is 40-50:52-65:56-70. This optimized ratio ensures the equilibrium of the Mannich reaction, generating a highly active and functional intermediate (i.e., an activator), thus guaranteeing subsequent grafting and adsorption performance.

[0020] As a preferred embodiment, in the above-mentioned method for preparing a high-efficiency, low-energy carbon capture and absorbent, the mass ratio of the active agent to the solid support in step (3) is 20-30:220-330. This ratio ensures that the active agent is uniformly grafted onto the surface of the support to form a stable functionalized adsorption layer, without excessive accumulation affecting mass transfer or insufficient adsorption capacity.

[0021] As a preferred embodiment, in the above-mentioned method for preparing a high-efficiency, low-energy carbon capture and absorbent, the reaction temperature in step (1) is room temperature, and the reaction time is 8-10 hours. Room temperature reaction conditions are mild and side reactions are avoided; 8-10 hours ensures a complete reaction.

[0022] As a preferred embodiment, in the above-mentioned method for preparing a high-efficiency, low-energy carbon capture and absorbent, step (2) involves a reaction at room temperature for 3-5 hours. Within this time range, the Mannich reaction can achieve a high conversion rate while avoiding over-reaction that could lead to product decomposition.

[0023] As a preferred embodiment, in the above-mentioned method for preparing a high-efficiency, low-energy carbon capture and absorbent, in step (3), the grafting temperature is 70-80℃ and the time is 10-12h. This temperature range is conducive to the chemical reaction between the silane segments and the surface of the support, forming a stable covalent bond; the long reaction time ensures the grafting density and uniformity, and improves the mechanical strength and cycle stability of the adsorbent.

[0024] A second aspect of the present invention provides a highly efficient and low-energy carbon capture and absorbent, which is prepared by the above-described preparation method.

[0025] Compared with the prior art, the present invention has at least the following beneficial effects: 1) In this invention, aminopyridine is first protected with di-tert-butyl dicarbonate to obtain protected aminopyridine. Then, the protected aminopyridine, 2,2,3,3,4,4,5,5-octafluoropentanal, and 3-aminopropyltrimethoxysilane are subjected to the Mannich reaction under the catalysis of acetic acid and deamination protection is carried out to generate an active agent containing silane segments. By grafting the silane segments onto the support, a high-efficiency and low-energy carbon capture and absorbent is obtained, which realizes the simultaneous improvement of adsorption capacity and regeneration efficiency, and also enhances the stability and resistance to water vapor interference of the adsorbent system.

[0026] 2) The perfluoroalkyl chain in the activator of this invention is an electron-withdrawing group, which effectively enhances the nucleophilic attack ability of adjacent amino groups on carbon dioxide molecules through inductive effect, thereby improving the adsorption activity of carbon dioxide; at the same time, the perfluoroalkyl chain segment has a large volume and rigidity, which creates a significant steric hindrance effect in the molecular structure, which not only weakens the stability of CO2 adsorption products (carbamates) and reduces regeneration energy consumption, but also forms more open diffusion channels in the carrier pores after immobilization, providing a more favorable mass transfer channel for CO2 molecule diffusion, thus achieving a simultaneous improvement in adsorption capacity and regeneration efficiency.

[0027] 3) The silane segment introduced at the end of the active agent in this invention achieves covalent bonding and interface strengthening with the carrier, which significantly improves the stability of the absorbent in long-term cyclic operation.

[0028] 4) The silane and perfluoroalkyl segments in the active agent of this invention have extremely strong hydrophobicity, which can effectively repel water molecules in the environment and prevent water vapor from condensing in the pores of the adsorbent or competing with the active sites for adsorption. This significantly reduces the negative impact of humidity on CO2 capture capacity and improves the absorbent's resistance to water vapor interference.

[0029] The above description is merely an overview of the technical solution of the present invention. In order to better understand the technical means of the present invention and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of the present invention more apparent and understandable, specific embodiments of the present invention are described below. Detailed Implementation

[0030] The following description provides numerous specific details to offer a more thorough understanding of the technical solutions provided by this invention. However, it will be apparent to those skilled in the art that the technical solutions provided by this invention can be implemented without one or more of these details.

[0031] In the embodiments and comparative examples of this invention, the room temperature condition is 25±5℃.

[0032] In the embodiments and comparative examples of this invention, the raw materials are commercially available.

[0033] Example 1 A method for preparing a high-efficiency, low-energy carbon capture and absorbent includes the following steps: Step 1: Add 85 parts by mass of 2-aminopyridine to 800 parts by mass of tetrahydrofuran, and then add 153 parts by mass of di-tert-butyl dicarbonate. React at room temperature for 10 hours. After the reaction is complete, extract with ethyl acetate, collect the organic phase and remove the solvent by rotary evaporation under reduced pressure to obtain protected aminopyridine.

[0034] Step 2: Add 40 parts of protected aminopyridine, 65 parts of 2,2,3,3,4,4,5,5-octafluoropentanal, 56 parts of 3-aminopropyltrimethoxysilane, and 5 parts of acetic acid to ethanol. React at room temperature for 3 hours. After the reaction is complete, remove the solvent by vacuum distillation of the reaction solution. Then, place the solution in 300 parts of dichloromethane at 0°C and add 75 parts of trifluoroacetic acid. React for 1 hour. After the reaction is complete, remove the solvent by vacuum distillation to obtain the active agent.

[0035] Third step: Disperse 20 parts of activator and 330 parts of mesoporous silica together in 1200 parts of toluene by mass, sonicate evenly, react at 80°C for 10 hours, cool, filter and collect the solid, wash with anhydrous ethanol, and dry to obtain a high-efficiency and low-energy carbon capture and adsorbent.

[0036] A high-efficiency, low-energy carbon capture and absorbent is prepared by the above steps.

[0037] Example 2 A method for preparing a high-efficiency, low-energy carbon capture and absorbent includes the following steps: Step 1: Add 90 parts by mass of 3-aminopyridine to 680 parts by mass of tetrahydrofuran, and then add 162 parts by mass of di-tert-butyldicarbonate. React at room temperature for 8 hours. After the reaction is complete, extract with ethyl acetate, collect the organic phase and remove the solvent by rotary evaporation under reduced pressure to obtain protected aminopyridine.

[0038] Step 2: Add 50 parts of protected aminopyridine, 52 parts of 2,2,3,3,4,4,5,5-octafluoropentanal, 70 parts of 3-aminopropyltrimethoxysilane, and 4 parts of acetic acid to ethanol. React at room temperature for 5 hours. After the reaction is complete, remove the solvent by vacuum distillation. Then, place the reaction solution in 250 parts of dichloromethane at 5°C and add 60 parts of trifluoroacetic acid. React for 3 hours. After the reaction is complete, remove the solvent by vacuum distillation to obtain the activator.

[0039] The third step involves dispersing 30 parts of activator and 220 parts of activated carbon together in 1800 parts of toluene by mass, sonicating evenly, reacting at 70°C for 12 hours, cooling, filtering to collect the solid, washing with anhydrous ethanol, and drying to obtain a highly efficient and low-energy carbon capture and adsorbent.

[0040] A high-efficiency, low-energy carbon capture and absorbent is prepared by the above steps.

[0041] Example 3 A method for preparing a high-efficiency, low-energy carbon capture and absorbent includes the following steps: Step 1: Add 86 parts by mass of 4-aminopyridine to 720 parts by mass of tetrahydrofuran, and then add 158 parts by mass of di-tert-butyldicarbonate. React at room temperature for 9 hours. After the reaction is complete, extract with ethyl acetate, collect the organic phase and remove the solvent by rotary evaporation under reduced pressure to obtain protected aminopyridine.

[0042] Step 2: Add 45 parts of protected aminopyridine, 55 parts of 2,2,3,3,4,4,5,5-octafluoropentanal, 62 parts of 3-aminopropyltrimethoxysilane, and 4.5 parts of acetic acid to ethanol. React at room temperature for 4 hours. After the reaction is complete, remove the solvent by vacuum distillation of the reaction solution. Then, place the solution in 275 parts of dichloromethane at 3°C ​​and add 63 parts of trifluoroacetic acid. React for 2 hours. After the reaction is complete, remove the solvent by vacuum distillation to obtain the activator.

[0043] The third step involves dispersing 25 parts of activator and 250 parts of graphene together in 1600 parts of toluene by mass, sonicating them uniformly, reacting at 75°C for 11 hours, cooling, filtering to collect the solid, washing with anhydrous ethanol, and drying to obtain a highly efficient and low-energy carbon capture and adsorbent.

[0044] A high-efficiency, low-energy carbon capture and absorbent is prepared by the above steps.

[0045] Comparative Example 1 Step 1: Add 85 parts by mass of 2-aminopyridine to 800 parts by mass of tetrahydrofuran, and then add 153 parts by mass of di-tert-butyl dicarbonate. React at room temperature for 10 hours. After the reaction is complete, extract with ethyl acetate, collect the organic phase and remove the solvent by rotary evaporation under reduced pressure to obtain protected aminopyridine.

[0046] Step 2: Add 40 parts of protected aminopyridine, 65 parts of pentanal, 56 parts of 3-aminopropyltrimethoxysilane, and 5 parts of acetic acid to ethanol and react at room temperature for 3 hours. After the reaction is complete, remove the solvent by vacuum distillation of the reaction solution. Then, place it in 300 parts of dichloromethane at 0°C and add 75 parts of trifluoroacetic acid. React for 1 hour. After the reaction is complete, remove the solvent by vacuum distillation to obtain the active agent.

[0047] Third step: Disperse 20 parts of activator and 330 parts of mesoporous silica together in 1200 parts of toluene by mass, sonicate evenly, react at 80°C for 10 hours, cool, filter and collect the solid, wash with anhydrous ethanol, and dry to obtain a high-efficiency and low-energy carbon capture and adsorbent.

[0048] The only difference between Comparative Example 1 and Example 1 is that 2,2,3,3,4,4,5,5-octafluoropentanal is replaced with pentanal.

[0049] Comparative Example 2 Step 1: Add 85 parts by mass of 2-aminopyridine to 800 parts by mass of tetrahydrofuran, and then add 153 parts by mass of di-tert-butyl dicarbonate. React at room temperature for 10 hours. After the reaction is complete, extract with ethyl acetate, collect the organic phase and remove the solvent by rotary evaporation under reduced pressure to obtain protected aminopyridine.

[0050] Step 2: Add 40 parts of protected aminopyridine, 65 parts of 2,2,3,3,4,4,5,5-octafluoropentanal, 56 parts of 3-aminopropyltrimethylsilane, and 5 parts of acetic acid to ethanol. React at room temperature for 3 hours. After the reaction is complete, remove the solvent by vacuum distillation. Then, place the reaction solution in 300 parts of dichloromethane at 0°C and add 75 parts of trifluoroacetic acid. React for 1 hour. After the reaction is complete, remove the solvent by vacuum distillation to obtain the active agent.

[0051] Third step: Disperse 20 parts of activator and 330 parts of mesoporous silica together in 1200 parts of toluene by mass, sonicate evenly, react at 80°C for 10 hours, cool, filter and collect the solid, wash with anhydrous ethanol, and dry to obtain a high-efficiency and low-energy carbon capture and adsorbent.

[0052] The only difference between Comparative Example 2 and Example 1 is that 3-aminopropyltrimethoxysilane is replaced with 3-aminopropyltrimethylsilane.

[0053] Comparative Example 3 20 parts of polyethyleneimine and 330 parts of mesoporous silica support were added to a 40% (v / v) ethanol solution, stirred at 45°C for 8 hours, and dried to obtain the adsorbent.

[0054] Experimental Example 1 The absorbents in each embodiment and each comparative example were subjected to the following performance tests, and the test results are shown in Table 1.

[0055] 1. Adsorption capacity and adsorption activity test: A mixed gas consisting of 10% (volume) CO2 and 90% (volume) N2 was used to simulate dry flue gas. 1g of each adsorbent sample was filled into a fixed bed adsorption device. Subsequently, the dry simulated flue gas was flowed through the fixed bed at a flow rate of 10mL / min at 45℃ and normal pressure. The carbon dioxide capture rate was tested according to GB / T45121-2024 "Technical Specification for Energy Consumption Measurement of Flue Gas Carbon Dioxide Capture System in Thermal Power Plant". The result is shown in Table 1.

[0056] 2. Regeneration efficiency and regeneration energy consumption test: A mixed gas consisting of 10% (volume) CO2 and 90% (volume) N2 was used to simulate dry flue gas. 1g of each adsorbent sample was filled into the fixed bed adsorption device. Subsequently, the dry simulated flue gas was flowed through the fixed bed at a flow rate of 10mL / min at 45℃ and normal pressure. Referring to GB / T45121-2024 "Technical Specification for Energy Consumption Measurement of Flue Gas Carbon Dioxide Capture System in Thermal Power Plants", the heat consumption for regeneration of ton of carbon dioxide was tested (not exceeding 3.5GJ / tCO2). The results are shown in Table 1.

[0057] 3. Mechanical stability and cycle life test: 1g of each adsorbent sample was loaded into a fixed bed adsorption device, and simulated flue gas (CO2 volume fraction 10%, N2 volume fraction 90%) was introduced. The gas was continuously introduced at 10mL / min at 45℃ and atmospheric pressure until the sample was saturated. Then, the inert gas N2 was switched (flow rate 10mL / min), the temperature was raised to 110℃, and desorption was maintained at atmospheric pressure until the sample was completely desorbed. The above process was repeated. After 100 cycles, the carbon dioxide capture rate was tested again according to GB / T45121-2024 "Technical Specification for Energy Consumption Measurement of Flue Gas Carbon Dioxide Capture System in Thermal Power Plants". The result was recorded as carbon dioxide capture rate 2. The results are shown in Table 1.

[0058] 4. Resistance to water vapor interference test: A mixture of 10% (volume) CO2 and 90% (volume) N2 was used to simulate dry flue gas. Wet flue gas was humidified by a constant-temperature water bath bubbling method to maintain a water vapor partial pressure of 10 kPa. 1 g of each adsorbent sample was packed into a fixed bed. Subsequently, the humid simulated flue gas was flowed through the fixed bed at 10 mL / min under normal pressure and at 45℃. The carbon dioxide capture rate was then tested again according to GB / T45121-2024 "Technical Specification for Energy Consumption Measurement of Flue Gas Carbon Dioxide Capture System in Thermal Power Plants," and the result was calculated as a carbon dioxide capture rate of 3. The results are shown in Table 1.

[0059] Table 1

[0060] As shown in Table 1: 1. The high-efficiency, low-energy carbon capture and absorbent prepared by the present invention (Example) has a significantly better initial adsorption capacity for CO2 under dry conditions than the comparative adsorbent (Comparative Example), exhibiting higher adsorption capacity and adsorption activity.

[0061] The likely cause is the introduction of perfluoroalkyl chains (which enhance the nucleophilic attack of amino groups on CO2) and silane segments into the surfactant (which improve the stability of carrier binding and the openness of diffusion channels).

[0062] 2. The regeneration energy consumption of the adsorbent of the present invention is significantly lower than that of the comparative adsorbent, indicating that it has a lower regeneration temperature or easier desorption characteristics, thus achieving the goal of "low energy consumption".

[0063] The speculated cause is that the steric hindrance effect of the perfluoroalkyl group in the surfactant weakens the stability of the carbamate, allowing it to desorb at lower temperatures and significantly reducing heat consumption. Simultaneously, the silane grafting structure enhances cycling stability, preventing structural collapse or activity loss caused by repeated regeneration.

[0064] 3. The adsorbent of this invention has excellent cycle stability and mechanical durability, and can maintain a high CO2 capture capacity during long-term use, which is far superior to traditional or comparative adsorbents.

[0065] The possible reasons are: the surfactant forms a covalent bond with the carrier through silane segments, which enhances the interfacial bonding and structural integrity; at the same time, the hydrophobic properties of perfluoroalkyl groups and silanes also help to reduce pore blockage and loss of active components.

[0066] 4. The adsorbent of this invention has extremely strong resistance to water vapor interference and can still maintain high CO2 capture performance in humid environments, which is a prominent advantage that comparative adsorbents do not possess.

[0067] The possible cause is that the silane and perfluoroalkyl segments in the surfactant have strong hydrophobicity, which can effectively repel water molecules and prevent water from condensing in the pores or competing with CO2 for adsorption sites, thereby ensuring the stability of the adsorbent under humid conditions.

[0068] As can be seen from Examples 1-3 and Comparative Examples 1-3, the absorbent of the present invention has a better carbon dioxide capture capacity and lower energy consumption during regeneration and recycling, achieving a simultaneous improvement in adsorption capacity and regeneration efficiency; it also has stronger stability and resistance to water vapor interference.

[0069] This article uses specific examples to illustrate the principles and implementation methods of the present invention. The descriptions of the above embodiments are only for the purpose of helping to understand the method and core ideas of the present invention, including the best mode, and also to enable any person skilled in the art to practice the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made to the present invention without departing from the principles of the present invention, and these improvements and modifications also fall within the protection scope of the claims of the present invention.

Claims

1. A method for preparing a high-efficiency, low-energy-consumption carbon capture and absorbent, characterized in that, The preparation method includes: (1) Reaction of aminopyridine with di-tert-butyl dicarbonate yields protected aminopyridine; (2) The protected aminopyridine was reacted with 2,2,3,3,4,4,5,5-octafluoropentanal and 3-aminopropyltrimethoxysilane in a Mannich reaction to obtain the activator; (3) The active agent is grafted onto a solid support to obtain the high-efficiency and low-energy carbon capture adsorbent.

2. The method of claim 1, wherein the method further comprises: The preparation method includes: (1) Add aminopyridine to the first solvent, then add di-tert-butyl dicarbonate, react, after the reaction is complete, extract, collect the organic phase and remove the solvent to obtain protected aminopyridine; (2) Add protected aminopyridine, 2,2,3,3,4,4,5,5-octafluoropentanal, 3-aminopropyltrimethoxysilane and weak acid catalyst to the second solvent, react, remove the solvent from the reaction solution after the reaction is completed, and then remove the tert-butyloxycarbonyl group to obtain the activator. (3) Disperse the activator and solid support in a third solvent to graft the activator onto the solid support, then filter and collect the solid, optionally wash and optionally dry it to obtain the high-efficiency and low-energy carbon capture adsorbent.

3. The method of claim 2, wherein the method further comprises: Satisfy at least one of the following characteristics: In step (1), the first solvent is tetrahydrofuran; In step (1), the extractant is ethyl acetate; In step (1), the solvent is removed by rotary evaporation under reduced pressure; In step (2), the second solvent is ethanol; In step (2), the weak acid catalyst is acetic acid; In step (2), the solvent is removed by vacuum distillation; In step (3), the third solvent is toluene.

4. The method of claim 2, wherein the method further comprises: In step (2), the steps of removing the tert-butyloxycarbonyl group after removing the solvent from the reaction solution include: placing it in dichloromethane at 0-5℃, then adding trifluoroacetic acid, stirring for 1-3 hours, and removing the solvent after the reaction is completed.

5. The method of claim 1 or 2, wherein the method is characterized by, The aminopyridine is at least one of 2-aminopyridine, 3-aminopyridine, and 4-aminopyridine.

6. The method of claim 1 or 2, wherein the method is characterized by, The solid support is at least one of mesoporous silica, activated carbon, and graphene.

7. The method of claim 1 or 2, wherein the method is characterized by, Satisfy at least one of the following characteristics: In step (1), the mass ratio of aminopyridine to di-tert-butyl dicarbonate is 85-90:153-162; In step (2), the mass ratio of protected aminopyridine, 2,2,3,3,4,4,5,5-octafluoropentanal, and 3-aminopropyltrimethoxysilane is 40-50:52-65:56-70. In step (3), the mass ratio of activator to solid carrier is 20-30: 220-330.

8. The method of claim 1, wherein the method further comprises: Satisfy at least one of the following characteristics: In step (1), the reaction temperature is room temperature and the reaction time is 8-10 hours; In step (2), the reaction temperature is room temperature and the reaction time is 3-5 hours.

9. The method of claim 1, wherein the method further comprises: In step (3), the grafting temperature is 70-80℃ and the grafting time is 10-12h.

10. A high efficiency low energy carbon capture absorbent characterized in that, The high-efficiency, low-energy carbon capture and absorbent is prepared by the preparation method described in any one of claims 1-9.

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