A CO2 adsorption-desorption material and its preparation method

Abstract

This invention discloses a CO2 adsorption / desorption material and its preparation method. First, allyltrimethylammonium chloride is dissolved in ethanol. Nitrogen gas is introduced into the solution, and 3-(isobutyrooxy)propyltrimethoxysilane and azobisisobutyronitrile are added for a condensation reaction. The mixture is then placed in an oil bath and magnetically stirred. TiO2 is then added to react and quaternized TiO2 is obtained. The quaternized TiO2 and ion exchange resin powder are added to the solvent N,N-dimethylacetamide for ultrasonic dispersion. Polyethylene powder is then added and shaken in a gas bath to obtain a casting solution. The casting solution is then subjected to degassing, ultrasonication, coating, drying, and cooling to obtain a formed ion exchange membrane. This invention can capture CO2 from dispersed emission sources, such as automobiles and airplanes, solving the problem of the large quantity and wide distribution of distributed carbon sources.

Description

Technical Field

[0001] This invention belongs to the field of direct air capture technology of carbon dioxide, and relates to a CO2 adsorption-desorption material and its preparation method. Background Technology

[0002] Fossil fuels such as coal, oil, and natural gas have supported the development and normal functioning of human society. However, over-reliance on fossil fuels has also brought many problems. With the rapid development of modern society, the excessive combustion of fossil fuels has led to excessive CO2 emissions, which is considered the main culprit for climate change, characterized primarily by global warming. The continuous rise in global temperatures will bring numerous disasters, such as glacial melting, rising sea levels, and the submergence of coastal islands and regions; the intensification of climate change will lead to more frequent extreme weather events, severe damage to ecosystems, and serious challenges to the survival of humans and other species.

[0003] Against this backdrop, CCUS (Carbon Dioxide Capture, Utilization and Storage) is becoming one of the key technologies for addressing excessive carbon dioxide emissions. Traditional capture methods are divided into pre-combustion capture, oxy-fuel combustion, and post-combustion capture. Pre-combustion capture converts the carbon-containing components in the fuel into water gas, thereby separating the carbon dioxide from it. This method is mostly used in integrated gasification combined cycle power plants. Oxy-fuel combustion separates pure oxygen from the air and introduces it into the combustion system, supplemented by flue gas recirculation. This technology captures carbon dioxide with high purity, but the total system investment is high. Post-combustion capture separates carbon dioxide from the flue gas. Although this technology requires less modification to the original system and is widely used, its energy consumption is high. On the other hand, the development of direct air capture (DAC) technology—capturing carbon dioxide directly from the air and permanently converting and storing it for small-scale fossil fuel combustion and decentralized emission sources such as vehicles—is also essential. Summary of the Invention

[0004] In view of the shortcomings of the existing technology, the purpose of this invention is to provide a CO2 adsorption-desorption material and its preparation method to solve the problem of excessive carbon dioxide emissions.

[0005] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0006] A method for preparing a CO2 adsorption-desorption material includes the following steps:

[0007] Step 1: Allyltrimethylammonium chloride is placed in a flask and dissolved in ethanol at room temperature, while nitrogen gas is introduced into the solution to purge the oxygen; then 3-(isobutenoyloxy)propyltrimethoxysilane and azobisisobutyronitrile are added; then the mixture is placed in an oil bath and magnetically stirred for reaction.

[0008] Step 2: Add TiO2 to the flask from Step 1 and continue the magnetic stirring reaction in an oil bath at 80°C; remove the reaction solution, cool it to room temperature, and centrifuge; wash the product multiple times with ethanol; and vacuum dry the product to obtain quaternized TiO2.

[0009] Step 3: First, add quaternized TiO2 and ion exchange resin powder to the solvent N,N-dimethylacetamide for ultrasonic dispersion; then add polyethylene powder and oscillate in an air bath shaker to obtain a completely dissolved casting solution; then degas and sonicate the casting solution.

[0010] Step 4: Pour the degassed casting solution onto a clean glass plate and use an automatic film scraper to scrape the film. Quickly place the scraped film into a vacuum drying oven for vacuum drying, then remove the film and cool it at room temperature to obtain a formed ion exchange membrane.

[0011] Step 5: Rinse the prepared ion exchange membrane with deionized water, then soak the ion exchange membrane in deionized water; then store it in NaCl solution to finally obtain the CO2 adsorption-desorption material.

[0012] The present invention also includes the following technical features:

[0013] Specifically, the mass ratio of allyltrimethylammonium chloride, 3-(isobutyrooxy)propyltrimethoxysilane and azobisisobutyronitrile is 1:1:0.07;

[0014] The mass ratio of N,N-dimethylacetamide, polyethylene powder, ion exchange resin powder and quaternized TiO2 is 55:35:10:(0.25-2).

[0015] Specifically, the mass ratio of N,N-dimethylacetamide, polyethylene powder, ion exchange resin powder, and quaternized TiO2 is 55:35:10:0.5.

[0016] Specifically, in step 1, the oil bath temperature is 80°C, and the reaction is carried out with magnetic stirring for 3 hours.

[0017] Specifically, in step 2, the oil bath temperature is 80°C, and the reaction is carried out with magnetic stirring for 24 hours; the vacuum drying temperature is 60°C, and the time is 24 hours.

[0018] Specifically, in step 3, the temperature of the air bath shaker is 60℃, and the rotation speed is 180-200 r·min. -1 Shake for 24 hours; ultrasonically disperse for 1 hour; ultrasonically sonicate the casting solution for 2 hours.

[0019] Specifically, in step 4, the vacuum drying temperature is 60°C and the time is 24 hours.

[0020] Specifically, in step 5, the ion exchange membrane is soaked in deionized water for 12 hours.

[0021] Specifically, in step 5, the NaCl solution concentration is 0.05 mol·L⁻¹. -1 .

[0022] A CO2 adsorption-desorption material is prepared using the method described above.

[0023] Compared with the prior art, the present invention has the following technical effects:

[0024] This invention can capture CO2 emitted from dispersed emission sources, such as automobiles and airplanes, solving the problems of the huge number and wide distribution of distributed carbon sources.

[0025] This invention combines the excellent hydrophilicity (hydroxyl groups on the TiO2 surface, giving it hydrophilicity) and mechanical properties of nanomaterials with the membrane substrate (i.e., the basic material for preparing resin membranes: polyethylene) during the preparation process. By functionalizing the surface of the nanomaterials to give them positively charged groups that can exchange with ions, and then doping them into the ion exchange membrane, the ion exchange sites of the membrane are increased. Compared with the previous preparation process, which used dichloromethyl ether, a chloromethylated catalyst, which has strong carcinogenicity and is extremely harmful to human health, and used the method of immersing the membrane in solutions such as trimethylamine for functionalization, resulting in reduced dimensional stability and deterioration of mechanical properties, the preparation method of this invention is simpler and greener.

[0026] The modified ion exchange resin membrane prepared by this invention exhibits a significant increase in water content, ion exchange capacity, fixed charge concentration, and ion selective permeability, while also showing a substantial decrease in membrane surface resistance.

[0027] The resin membrane material obtained by this invention adsorbs CO2 when the surrounding atmosphere is dry and releases CO2 when it is humid through controllable ion hydration. Since the CO2 regeneration process does not involve changes in temperature and pressure, no additional energy consumption is required, reducing operating costs and saving resources. Specifically, this invention achieves CO2 adsorption and desorption through heterogeneous ion exchange; when the membrane material is in a dry environment or with low water vapor concentration, the basic groups at the adsorbent interface adsorb CO2 from the atmosphere; when the membrane material is in an environment with high water vapor concentration or is immersed in water, the adsorbed CO2 is gradually desorbed. Detailed Implementation

[0028] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments. All equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0029] Except for the resin powder, which was purchased from Xi'an Lanxiao Technology New Material Co., Ltd., the other raw materials of this invention, such as allyltrimethylammonium chloride, 3-(isobutyrooxy)propyltrimethoxysilane, azobisisobutyronitrile, PE powder, etc., were all purchased from Chengjie Instrument Equipment Co., Ltd.

[0030] Example 1:

[0031] This embodiment provides a method for preparing a CO2 adsorption-desorption material, including the following steps:

[0032] Step 1: First, weigh 8g of allyltrimethylammonium chloride (TMA) and place it in a 500mL flask. Dissolve it in 200mL of ethanol at room temperature, while simultaneously purging the solution with nitrogen gas to remove any oxygen present. After the TMA is completely dissolved, add 8g of 3-(isobutyrooxy)propyltrimethoxysilane (MPS) and 0.56g of azobisisobutyronitrile (AIBN), and attach a condenser. Then, place the flask in an oil bath at 80℃ and stir magnetically for 3 hours. Remove the flask from the oil bath.

[0033] Step 2: Weigh 8g of TiO2 and add it to the above flask. Continue to stir the mixture magnetically in an oil bath at 80°C for 24 hours. After that, take out the well-reacted solution, cool it to room temperature, and centrifuge it. Wash the product with ethanol and centrifuge it several times. Finally, vacuum dry the product at 60°C for 24 hours.

[0034] Step 3: First, add quaternized TiO2 and ion exchange resin powder (passed through a 500-mesh sieve) to the solvent N,N-dimethylacetamide (DMAC) and ultrasonically disperse for 1 hour; then add polyethylene (PE) powder and shake in a 60°C air bath shaker at 180 r·min⁻¹ for 24 hours to obtain a completely dissolved casting solution; specifically, the ratio is 55 parts DMAC, 35 parts PE, 10 parts resin, and 0.25 parts quaternized TiO2 (mass ratio). Degas the casting solution and ultrasonically disperse for 2 hours.

[0035] Step 4: Pour the degassed casting solution onto a clean glass plate and use an automatic film scraper with a 500μm stainless steel doctor blade. Quickly place the scraped film into a vacuum drying oven and vacuum dry at 60℃ for 24 hours. Remove the membrane and cool it at room temperature to obtain the formed ion exchange membrane.

[0036] Step 5: Rinse the prepared ion exchange membrane with deionized water several times to remove residual DMAC solvent; then, immerse the membrane in deionized water for 12 hours; finally, store it in 0.05 mol·L⁻¹ water. -1 The membrane material was immersed in NaCl solution. After being immersed in room temperature deionized water for 2 days, it was then fully immersed in Na2CO3 solution.

[0037] The resulting membrane material has a water content C w The value was 11.47 (±1.10), and the IEC was 1.3 mmol·g. -1 The FIC was 11.46 mmol·g. -1 Ps is 0.915, and the film surface resistivity is 18 Ω·cm. 2 .

[0038] Example 2:

[0039] This embodiment provides a method for preparing a CO2 adsorption-desorption material, including the following steps:

[0040] Step 1: First, weigh 8g of TMA and place it in a 500mL flask. Dissolve it in 200mL of ethanol at room temperature, while simultaneously purging nitrogen gas into the solution to remove any oxygen present. After the TMA is completely dissolved, add 8g of MPS and 0.56g of AIBN, and attach a condenser. Then, place the flask in an oil bath at 80℃ and stir magnetically for 3 hours. Remove the flask from the oil bath.

[0041] Step 2: Weigh 8g of TiO2 and add it to the above flask. Continue to stir the mixture magnetically in an oil bath at 80°C for 24 hours. After that, take out the well-reacted solution, cool it to room temperature, and centrifuge it. Wash the product with ethanol and centrifuge it several times. Finally, vacuum dry the product at 60°C for 24 hours.

[0042] Step 3: First, add quaternized TiO2 and ion exchange resin powder to the solvent N,N-dimethylacetamide (DMAC) and ultrasonically disperse for 1 hour; then add polyethylene (PE) powder and shake in a 60°C air bath at a speed of 200 r·min. -1 Shake for 24 hours to obtain a completely dissolved casting solution; specifically, the composition is 55 parts DMAC, 35 parts PE, 10 parts resin, and 0.5 parts quaternized TiO2 (mass ratio). The casting solution is then degassed and sonicated for 2 hours.

[0043] Step 4: Pour the degassed casting solution onto a clean glass plate and use an automatic film scraper with a 500μm stainless steel doctor blade. Quickly place the scraped film into a vacuum drying oven and vacuum dry at 60℃ for 24 hours. Remove the membrane and cool it at room temperature to obtain the formed ion exchange membrane.

[0044] Step 5: Rinse the prepared ion exchange membrane with deionized water several times to remove residual DMAC solvent; then, immerse the membrane in deionized water for 12 hours; finally, store it in 0.05 mol·L⁻¹ water. -1 The membrane material was immersed in NaCl solution. After being immersed in room temperature deionized water for 3 days, it was then fully immersed in Na2CO3 solution.

[0045] The resulting membrane material has a water content C w The value was 12.58 (±0.96), and the IEC was 1.39 mmol·g. -1 The FIC was 11.15 mmol·g. -1 The Ps value is 0.935, and the film surface resistivity is 14.8 Ω·cm. 2 .

[0046] Example 3:

[0047] This embodiment provides a method for preparing a CO2 adsorption-desorption material, including the following steps:

[0048] Step 1: First, weigh 8g of TMA and place it in a 500mL flask. Dissolve it in 200mL of ethanol at room temperature, while simultaneously purging nitrogen gas into the solution to remove any oxygen present. After the TMA is completely dissolved, add 8g of MPS and 0.56g of AIBN, and attach a condenser. Then, place the flask in an oil bath at 80℃ and stir magnetically for 3 hours. Remove the flask from the oil bath.

[0049] Step 2: Weigh 8g of TiO2 and add it to the above flask. Continue to stir the mixture magnetically in an oil bath at 80°C for 24 hours. After that, take out the well-reacted solution, cool it to room temperature, and centrifuge it. Wash the product with ethanol and centrifuge it several times. Finally, vacuum dry the product at 60°C for 24 hours.

[0050] Step 3: First, add quaternized TiO2 and ion exchange resin powder to the solvent N,N-dimethylacetamide (DMAC) and ultrasonically disperse for 1 hour; then add polyethylene (PE) powder and shake in a 60°C air bath shaker at 180 r·min⁻¹ for 24 hours to obtain a completely dissolved casting solution; specifically, the ratio is 55 parts DMAC, 35 parts PE, 10 parts resin, and 1 part quaternized TiO2 (mass ratio). Degas the casting solution and ultrasonically disperse for 2 hours.

[0051] Step 4: Pour the degassed casting solution onto a clean glass plate and use an automatic film scraper with a 500μm stainless steel doctor blade. Quickly place the scraped film into a vacuum drying oven and vacuum dry at 60℃ for 24 hours. Remove the membrane and cool it at room temperature to obtain the formed ion exchange membrane.

[0052] Step 5: Rinse the prepared ion exchange membrane with deionized water several times to remove residual DMAC solvent; then, immerse the membrane in deionized water for 12 hours; finally, store it in 0.05 mol·L⁻¹ water. -1 The membrane material was immersed in NaCl solution. After being immersed in deionized water at room temperature for 4 days, it was then fully immersed in Na2CO3 solution.

[0053] The resulting membrane material has a water content C w The value was 13.40 (±1.03), and the IEC was 1.46 mmol·g. -1 The FIC was 9.35 mmol·g. -1 Ps is 0.908, and the film surface resistivity is 16 Ω·cm. 2 .

[0054] Example 4:

[0055] This embodiment provides a method for preparing a CO2 adsorption-desorption material, including the following steps:

[0056] Step 1: First, weigh 8g of TMA and place it in a 500mL flask. Dissolve it in 200mL of ethanol at room temperature, while simultaneously purging nitrogen gas into the solution to remove any oxygen present. After the TMA is completely dissolved, add 8g of MPS and 0.56g of AIBN, and attach a condenser. Then, place the flask in an oil bath at 80℃ and stir magnetically for 3 hours. Remove the flask from the oil bath.

[0057] Step 2: Weigh 8g of TiO2 and add it to the above flask. Continue to stir the mixture magnetically in an oil bath at 80°C for 24 hours. After that, take out the well-reacted solution, cool it to room temperature, and centrifuge it. Wash the product with ethanol and centrifuge it several times. Finally, vacuum dry the product at 60°C for 24 hours.

[0058] Step 3: First, add quaternized TiO2 and ion exchange resin (anion exchange resin in this example) powder to the solvent N,N-dimethylacetamide (DMAC) and ultrasonically disperse for 1 hour; then add polyethylene (PE) powder and shake in a 60°C air bath shaker at 180 r·min⁻¹ for 24 hours to obtain a completely dissolved casting solution; specifically, the ratio is 55 parts DMAC, 35 parts PE, 10 parts resin, and 2 parts quaternized TiO2 (mass ratio). Degas the casting solution and ultrasonically disperse for 2 hours.

[0059] Step 4: Pour the degassed casting solution onto a clean glass plate and use an automatic film scraper with a 500μm stainless steel doctor blade. Quickly place the scraped film into a vacuum drying oven and vacuum dry at 60℃ for 24 hours. Remove the membrane and cool it at room temperature to obtain the formed ion exchange membrane.

[0060] Step 5: Rinse the prepared ion exchange membrane with deionized water several times to remove residual DMAC solvent; then, immerse the membrane in deionized water for 12 hours; finally, store it in 0.05 mol·L⁻¹ water. -1The membrane material was immersed in NaCl solution. After being immersed in deionized water at room temperature for 5 days, it was then fully immersed in Na2CO3 solution.

[0061] The resulting membrane material has a water content C w The value was 15.95 (±1.34), and the IEC was 1.62 mmol·g. -1 The FIC was 9.21 mmol·g. -1 Ps is 0.894, and the film surface resistivity is 19.5 Ω·cm. 2 .

[0062] As can be seen from Examples 1 to 4, different TiO2 doping ratios can improve the basic properties of the membrane material. Among them, when the TiO2 doping ratio is 0.5, the ion selective permeability of the membrane material reaches a maximum of 0.935, while the surface resistivity reaches a minimum of 14.8 Ω·cm. 2 .

[0063] Comparative Example 1:

[0064] The difference between this comparative example and the previous example is that quaternized nanoparticles were not incorporated into the anion exchange membrane during preparation; instead, the membrane material was prepared solely using an evaporation solvent-phase inversion method. The resulting membrane material had a water content of 9.67% and an IEC of 1.085 mmol·g. -1 The FIC was 10.9 mmol·g. -1 Ps is 0.835, and the film surface resistivity is 33.5 Ω·cm. 2 .

[0065] As can be seen from the above examples and comparative examples, after incorporating TiO2 into the membrane material matrix, the water content, ion exchange capacity, fixed charge concentration, and ion selective permeability of the membrane material all show a significant increase, while the membrane surface resistivity also decreases substantially. This demonstrates that combining the excellent hydrophilicity and mechanical properties of nanomaterials with the membrane substrate has a positive effect on improving the performance of membrane materials.

Claims

1. A method for producing a CO2 adsorption / desorption material, characterized by, Includes the following steps: Step 1: Place allyltrimethylammonium chloride in a flask and dissolve it in ethanol at room temperature, while simultaneously bubbling nitrogen gas into the solution to remove any oxygen. Then add 3-(isobutenoyloxy)propyltrimethoxysilane and azobisisobutyronitrile; then place in an oil bath and perform a magnetically stirred reaction; Step 2: Add TiO2 to the flask from Step 1 and continue the magnetic stirring reaction in an oil bath at 80°C; remove the reaction solution, cool it to room temperature, and centrifuge; wash the product multiple times with ethanol. The product was vacuum dried to obtain quaternized TiO2; Step 3: First, add quaternized TiO2 and ion exchange resin powder to the solvent N,N-dimethylacetamide for ultrasonic dispersion; then add polyethylene powder and oscillate in an air bath shaker to obtain a completely dissolved casting solution; then degas and sonicate the casting solution. Step 4: Pour the degassed casting solution onto a clean glass plate and use an automatic film scraper to scrape the film. Quickly place the scraped film into a vacuum drying oven for vacuum drying, then remove the film and cool it at room temperature to obtain a formed ion exchange membrane. Step 5: Rinse the prepared ion exchange membrane with deionized water, then soak the ion exchange membrane in deionized water; then store it in NaCl solution to finally obtain the CO2 adsorption-desorption material.

2. The method for preparing the CO2 adsorption-desorption material as described in claim 1, characterized in that, The mass ratio of allyltrimethylammonium chloride, 3-(isobutyrooxy)propyltrimethoxysilane and azobisisobutyronitrile is 1:1:0.07; The mass ratio of N,N-dimethylacetamide, polyethylene powder, ion exchange resin powder and quaternized TiO2 is 55:35:10:(0.25-2).

3. The method for preparing the CO2 adsorption-desorption material as described in claim 2, characterized in that, The mass ratio of N,N-dimethylacetamide, polyethylene powder, ion exchange resin powder, and quaternized TiO2 is 55:35:10:0.

5.

4. The method for preparing the CO2 adsorption-desorption material as described in claim 1, characterized in that, In step 1, the oil bath temperature is 80°C, and the reaction is carried out with magnetic stirring for 3 hours.

5. The method for preparing the CO2 adsorption-desorption material as described in claim 1, characterized in that, In step 2, the oil bath temperature is 80℃, and the reaction is carried out with magnetic stirring for 24 hours; the vacuum drying temperature is 60℃, and the time is 24 hours.

6. The method for preparing the CO2 adsorption-desorption material as described in claim 1, characterized in that, In step 3, the temperature of the air bath shaker is 60°C, and the rotation speed is 180-200 r·min -1 ; oscillation for 24 h; ultrasonic dispersion for 1 h; ultrasonic casting of the casting solution for 2 h.

7. The method for preparing the CO2 adsorption-desorption material as described in claim 1, characterized in that, In step 4, the vacuum drying temperature is 60℃ and the time is 24h.

8. The method for preparing the CO2 adsorption-desorption material as described in claim 1, characterized in that, In step 5, the ion exchange membrane is soaked in deionized water for 12 hours.

9. The method for preparing the CO2 adsorption-desorption material as described in claim 1, characterized in that, In step 5, the concentration of NaCl solution is 0.05 mol L -1 .

10. A CO2 adsorption-desorption material, characterized in that, It is prepared by the preparation method of CO2 adsorption-desorption material according to any one of claims 1 to 9.