Preparation method of phase change-potassium-based honeycomb CO2 composite adsorbent

Abstract

The invention discloses a preparation method of a phase change-potassium-based honeycomb CO2 composite adsorbent, which comprises the following steps: (1) dissolving potassium carbonate and aluminum oxide in a solvent according to a certain mass ratio to form sticky slurry; (2) adding a small amount of potassium hydroxide into the slurry to adjust the pH to be alkaline, and magnetically stirring the slurry to form an adsorbent; (3) attaching an adsorbent to the wall of the honeycomb material, drying and then calcining; and (4) after calcining, adding the phase change capsules into honeycomb material holes to prepare the composite adsorbent. According to the invention, the honeycomb material is treated by a coating method, and the spherical phase-change material is used for replacing the traditional powdery solid, so that the external additional heat required to be added is greatly reduced, the adsorption effect is good, the service life is long, the reaction efficiency is high, the gas mass transfer resistance is reduced, and the pressure drop is reduced.

Description

Technical Field

[0001] This invention belongs to the field of adsorbent preparation technology, specifically relating to a method for preparing a phase change-potassium-based honeycomb CO2 composite adsorbent. Background Technology

[0002] Among many solid adsorbent materials, potassium-based adsorbents have received widespread attention in recent years due to their high reactivity with CO2, good renewability, and suitable operating temperature range.

[0003] In engineering applications, traditional granular or powdered potassium-based adsorbents generally suffer from the following problems: large pressure drop in the granular bed limits large-scale flue gas treatment capacity; and granules are prone to wear, affecting long-term operational stability. To address these issues, honeycomb-shaped structured carriers have begun to replace traditional granular bed structures. By loading potassium-based adsorbents onto the inner walls of the honeycomb carrier channels, a low-pressure-drop gas-solid contact mode is achieved. In existing technologies, the introduction of potassium-based adsorbents into honeycomb carriers mainly employs the impregnation method. However, the impregnation method is prone to pore blockage under high-load conditions, affecting airflow; uneven distribution of active components within the honeycomb channels leads to reduced adsorption efficiency; insufficient bonding strength between the adsorbent layer and the carrier results in easy detachment during cyclic operation; and the effects of different coating times and the ratio of active components to binders on structural integrity and adsorption performance lack systematic optimization.

[0004] In the adsorption of CO2 in solids, the adsorption reaction is usually accompanied by significant exothermic reactions. Increased bed temperature can shift the adsorption equilibrium in an unfavorable direction, thereby reducing adsorption capacity and shortening breakthrough time. To alleviate the temperature rise problem during adsorption, we explored introducing phase change materials (PCMs) into the adsorption system. By utilizing the latent heat absorbed or released by the PCM near its phase change temperature, bed temperature regulation can be achieved. Microencapsulation of the PCM effectively prevents leakage and improves its stability in complex systems.

[0005] Therefore, there is an urgent need to propose a method for preparing a phase change-potassium-based honeycomb CO2 composite adsorbent in order to achieve efficient adsorbent adhesion, stable introduction of phase change capsules, and synergistic improvement of overall performance. Summary of the Invention

[0006] To address the aforementioned issues, this invention discloses a method for preparing a phase change-potassium-based honeycomb CO2 composite adsorbent. The honeycomb material is treated by coating, and spherical phase change material is used instead of traditional powdered solid, which greatly reduces the additional heat required from the outside, resulting in good adsorption effect, long service life, high reaction efficiency, reduced gas mass transfer resistance, and lower pressure drop.

[0007] To achieve the above objectives, the technical solution of the present invention is as follows: A method for preparing a phase change-potassium-based honeycomb CO2 composite adsorbent includes the following steps: (1) Dissolve potassium carbonate and aluminum oxide in a solvent in a certain mass ratio to form a viscous slurry; (2) Add a small amount of potassium hydroxide to the slurry to adjust the pH to alkaline, and then magnetically stir the slurry to form an adsorbent; (3) The adsorbent is attached to the wall of the honeycomb material, dried and then calcined; (4) After calcination, phase change capsules are added into the pores of the honeycomb material to obtain a composite adsorbent.

[0008] In step (1), the mass ratio of potassium carbonate to aluminum oxide is 3-5:3; preferably 4:3. In step (1), the solvent is deionized water.

[0009] In step (3), the adhesion method is a coating method.

[0010] In step (3), the coating is applied twice.

[0011] In step (3), the honeycomb material is titanium dioxide.

[0012] In step (4), the shell material of the phase change capsule is PMMA.

[0013] In step (4), the phase change capsule is prepared by laboratory extrusion-spheronization.

[0014] The beneficial effects of this invention are as follows: (1) In this invention, the honeycomb material is first processed by coating the adsorbent onto the wall of the honeycomb material, adding phase change capsules, and then contacting it with flue gas to carry out an adsorption reaction. The heat released during adsorption is absorbed by the phase change capsules. After the reaction is completed, the heat can be replaced by a heat exchanger for the desorption reaction of the adsorbent. This invention greatly reduces the additional heat required from the outside and uses spherical phase change material instead of traditional powdered solid. The specific surface area of ​​the phase change material is increased, the reaction efficiency is high, the gas mass transfer resistance is reduced, and the pressure drop is lower.

[0015] (2) The present invention uses a coating method to attach the adsorbent, which effectively avoids the pore blockage problem that is easy to cause by traditional attachment methods. At the same time, the adsorbent is attached evenly and firmly, which extends the service life of the composite adsorbent.

[0016] (3) By introducing solid alumina, the present invention enhances the viscosity of the slurry, thereby improving the adhesion of the adsorbent to the wall surface and extending the service life of the composite adsorbent.

[0017] (4) The raw materials selected in this invention are alumina, potassium carbonate, etc., which are common, readily available, have large reserves, are inexpensive, and have little impact on the environment, which is conducive to sustainable development. Attached Figure Description

[0018] Figure 1 This is a schematic flowchart of the method of the present invention; Figure 2 Carbon dioxide adsorption curves of adsorbents prepared under different adsorbent adhesion methods; Figure 3 Carbon dioxide adsorption curves of adsorbents prepared for different honeycomb materials; Figure 4 Carbon dioxide adsorption curves of adsorbents prepared with different coating times when the mass ratio of potassium carbonate to aluminum oxide is 3:3; Figure 5 Carbon dioxide adsorption curves of adsorbents prepared with different coating times when the mass ratio of potassium carbonate to aluminum oxide is 4:3; Figure 6 Carbon dioxide adsorption curves of adsorbents prepared by single coating with different mass ratios of potassium carbonate and alumina; Figure 7 Carbon dioxide adsorption curves of adsorbents prepared by secondary coating with different mass ratios of potassium carbonate and alumina; Figure 8 Carbon dioxide adsorption curves of adsorbents prepared by three coating processes with different mass ratios of potassium carbonate to alumina; Figure 9 Bed temperature profiles with and without the addition of two types of phase change capsules; Figure 10 The adsorption curves of carbon dioxide by the adsorbent are shown when two types of phase change capsules are added and when no phase change capsules are added. Detailed Implementation

[0019] The present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments. It should be understood that the following specific embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Example

[0020] like Figure 1 As shown, this embodiment provides a method for preparing a phase change-potassium-based honeycomb CO2 composite adsorbent: Weigh 10g of potassium carbonate powder and 10g of alumina powder, and add 40ml of deionized water to form a viscous slurry. Weigh approximately 0.002g of potassium hydroxide to adjust the pH of the slurry to approximately 11. Then, place the slurry on a magnetic stirrer and stir at 300 rpm for 30 minutes to form an adsorbent. Subsequently, the adsorbent is coated onto the wall of a titanium dioxide honeycomb material. After coating, the honeycomb material is placed in a constant temperature drying oven at 105℃ for 12 hours to cure the adsorbent. Then, the honeycomb material is placed in a tube furnace and calcined at 300℃ for 3 hours. The calcined adsorbent is named HMTT-1-33.

[0021] The detailed method of coating in this embodiment is as follows: the honeycomb material is held with tweezers and manually operated to continuously switch between being immersed in the slurry and being removed from the slurry, and the coating is carried out for 30 minutes. Example

[0022] Weigh 10g of potassium carbonate powder and 10g of alumina powder, and add 40ml of deionized water to form a viscous slurry. Weigh approximately 0.002g of potassium hydroxide to adjust the pH of the slurry to approximately 11. Then, place the slurry on a magnetic stirrer and stir at 300r / min for 30min to form an adsorbent. Subsequently, the adsorbent is attached to the wall of a titanium dioxide honeycomb material using an impregnation method. After coating, the honeycomb material is placed in a constant temperature drying oven at 105℃ for 12h to cure the adsorbent. Then, the honeycomb material is placed in a tube furnace and calcined at 300℃ for 3h. The calcined adsorbent is named HMJT-1-33. Example

[0023] Weigh 10g of potassium carbonate powder and 10g of alumina powder, and add 40ml of deionized water to form a viscous slurry. Weigh approximately 0.002g of potassium hydroxide to adjust the pH of the slurry to approximately 11. Then, place the slurry on a magnetic stirrer and stir at 300 rpm for 30 minutes to form an adsorbent. Subsequently, the adsorbent is coated onto the wall of a zeolite honeycomb material. After coating, the honeycomb material is placed in a constant temperature drying oven at 105℃ for 12 hours to cure the adsorbent. Then, the honeycomb material is placed in a tube furnace and calcined at 300℃ for 3 hours. The calcined adsorbent is named HMTF-1-33. Example

[0024] Weigh 11.43g of potassium carbonate powder and 8.57g of alumina powder, and add 40ml of deionized water to form a viscous slurry. Weigh approximately 0.002g of potassium hydroxide to adjust the pH of the slurry to approximately 11. Then, place the slurry on a magnetic stirrer and stir at 300 rpm for 30 minutes to form an adsorbent. Subsequently, the adsorbent is coated onto the wall of a titanium dioxide honeycomb material. After coating, the honeycomb material is placed in a constant temperature drying oven at 105℃ for 12 hours to cure the adsorbent. Then, the honeycomb material is placed in a tube furnace and calcined at 300℃ for 3 hours. The calcined adsorbent is named HMTT-1-43. Example

[0025] Weigh 10g of potassium carbonate powder and 10g of alumina powder, and add 40ml of deionized water to form a viscous slurry. Weigh approximately 0.002g of potassium hydroxide to adjust the pH of the slurry to approximately 11. Then, place the slurry on a magnetic stirrer and stir at 300 rpm for 30 minutes to form an adsorbent. Subsequently, the adsorbent is coated onto the wall of a titanium dioxide honeycomb material. After coating, the honeycomb material is dried in a constant temperature drying oven at 105℃ for 4 hours. The coating operation is repeated once, and then the honeycomb material is dried in a constant temperature drying oven at 105℃ for 12 hours to solidify the adsorbent. Finally, the honeycomb material is placed in a tube furnace and calcined at 300℃ for 3 hours. The calcined adsorbent is named HMTT-2-33. Example

[0026] Weigh 11.43g of potassium carbonate powder and 8.57g of alumina powder, and add 40ml of deionized water to form a viscous slurry. Weigh approximately 0.002g of potassium hydroxide to adjust the pH of the slurry to approximately 11. Then, place the slurry on a magnetic stirrer and stir at 300 rpm for 30 minutes to form an adsorbent. Subsequently, the adsorbent is coated onto the wall of a titanium dioxide honeycomb material. After coating, the honeycomb material is dried in a constant temperature drying oven at 105℃ for 4 hours. The coating operation is repeated once, and then the honeycomb material is dried in a constant temperature drying oven at 105℃ for 12 hours to solidify the adsorbent. Finally, the honeycomb material is placed in a tube furnace and calcined at 300℃ for 3 hours. The calcined adsorbent is named HMTT-2-43. Example

[0027] Weigh 12.5g of potassium carbonate powder and 7.5g of alumina powder, and add 40ml of deionized water to form a viscous slurry. Weigh approximately 0.002g of potassium hydroxide to adjust the pH of the slurry to approximately 11. Then, place the slurry on a magnetic stirrer and stir at 300 rpm for 30 minutes to form an adsorbent. Subsequently, the adsorbent is coated onto the wall of a titanium dioxide honeycomb material. After coating, the honeycomb material is dried in a constant temperature drying oven at 105℃ for 4 hours. The coating operation is repeated once, and then the honeycomb material is dried in a constant temperature drying oven at 105℃ for 12 hours to solidify the adsorbent. Finally, the honeycomb material is placed in a tube furnace and calcined at 300℃ for 3 hours. The calcined adsorbent is named HMTT-2-53. Example

[0028] Weigh 10g of potassium carbonate powder and 10g of alumina powder, and add 40ml of deionized water to form a viscous slurry. Weigh approximately 0.002g of potassium hydroxide to adjust the pH of the slurry to approximately 11. Then, place the slurry on a magnetic stirrer and stir at 300 rpm for 30 minutes to form an adsorbent. Subsequently, the adsorbent is coated onto the wall of a titanium dioxide honeycomb material. After coating, the honeycomb material is dried in a constant temperature drying oven at 105℃ for 4 hours. The coating operation is repeated once, and then the honeycomb material is dried in a constant temperature drying oven at 105℃ for 4 hours. The coating operation is repeated once, and then the honeycomb material is dried in a constant temperature drying oven at 105℃ for 12 hours to solidify the adsorbent. Finally, the honeycomb material is placed in a tube furnace and calcined at 300℃ for 3 hours. The calcined adsorbent is named HMTT-3-33. Example

[0029] Weigh 11.43g of potassium carbonate powder and 8.57g of alumina powder, and add 40ml of deionized water to form a viscous slurry. Weigh approximately 0.002g of potassium hydroxide to adjust the pH of the slurry to approximately 11. Then, place the slurry on a magnetic stirrer and stir at 300 rpm for 30 minutes to form an adsorbent. Subsequently, the adsorbent is coated onto the wall of a titanium dioxide honeycomb material. After coating, the honeycomb material is dried in a constant temperature drying oven at 105℃ for 4 hours. The coating operation is repeated once, and then the honeycomb material is dried in a constant temperature drying oven at 105℃ for 4 hours. The coating operation is repeated once, and then the honeycomb material is dried in a constant temperature drying oven at 105℃ for 12 hours to solidify the adsorbent. Finally, the honeycomb material is placed in a tube furnace and calcined at 300℃ for 3 hours. The calcined adsorbent is named HMTT-3-43. Example

[0030] Weigh 11.43g of potassium carbonate powder and 8.57g of alumina powder, and add 40ml of deionized water to form a viscous slurry. Weigh approximately 0.002g of potassium hydroxide to adjust the pH of the slurry to approximately 11. Then, place the slurry on a magnetic stirrer and stir at 300 rpm for 30 minutes to form an adsorbent. Subsequently, the adsorbent is coated onto the wall of a titanium dioxide honeycomb material. After coating, the honeycomb material is dried in a constant temperature drying oven at 105℃ for 4 hours. The coating operation is repeated once, and then the honeycomb material is dried in a constant temperature drying oven at 105℃ for 12 hours to solidify the adsorbent. Finally, the honeycomb material is placed in a tube furnace and calcined at 300℃ for 3 hours. The calcined adsorbent is named HMTT-2-43-1. Example

[0031] Weigh 11.43g of potassium carbonate powder and 8.57g of alumina powder, and add 40ml of deionized water to form a viscous slurry. Weigh approximately 0.002g of potassium hydroxide to adjust the pH of the slurry to approximately 11. Then, place the slurry on a magnetic stirrer and stir at 300r / min for 30min to form an adsorbent. Subsequently, the adsorbent is coated onto the wall of a titanium dioxide honeycomb material. After coating, the honeycomb material is dried in a constant temperature drying oven at 105℃ for 4h. The coating operation is repeated once, and then the honeycomb material is dried in a constant temperature drying oven at 105℃ for 12h to solidify the adsorbent. The honeycomb material is then placed in a tube furnace and calcined at 300℃ for 3h. During adsorption, 0.7g of a phase change capsule with a silica shell is added to the adsorbent. The adsorbent is named HMTT-2-43-SiO2. Example

[0032] Weigh 11.43g of potassium carbonate powder and 8.57g of alumina powder, and add 40ml of deionized water to form a viscous slurry. Weigh approximately 0.002g of potassium hydroxide to adjust the pH of the slurry to approximately 11. Then, place the slurry on a magnetic stirrer and stir at 300 rpm for 30 minutes to form an adsorbent. Subsequently, the adsorbent is coated onto the wall of a titanium dioxide honeycomb material. After coating, the honeycomb material is dried in a constant temperature drying oven at 105℃ for 4 hours. The coating operation is repeated once, and then the honeycomb material is dried in a constant temperature drying oven at 105℃ for 12 hours to solidify the adsorbent. The honeycomb material is then placed in a tube furnace and calcined at 300℃ for 3 hours. During adsorption, 0.7g of a phase change capsule with a PMMA shell is added to the adsorbent. The adsorbent is named HMTT-2-43-PMMA.

[0033] Carbon dioxide adsorption tests were conducted on the composite adsorbent. The experimental setup used was the HP-WF51 catalytic evaluation device manufactured by Nanjing Zirconium & Power Equipment Co., Ltd. During the test, the temperature was increased to 60℃ at a rate of 4℃ / min under a nitrogen atmosphere. Then, carbon dioxide with a concentration of 10% and a total flow rate of 300 ml / min was introduced. After 60 min, the adsorbent approached adsorption saturation. The carbon dioxide concentration at the tail end was detected using an FGA10 integrated flue gas analyzer manufactured by Shenzhen Better Analytical Instruments Co., Ltd.

[0034] For Examples 1 and 2, and Examples 1 and 3, the test methods were as described above, and the results are shown in the appendix. Figure 2 and Figure 3 As shown. By Figure 2 and Figure 3 It can be seen that the adsorbent prepared in Example 1 has a higher carbon dioxide adsorption capacity. That is, the carbon dioxide adsorption capacity is the highest when titanium dioxide is used in the honeycomb material and the adsorbent is attached by coating method.

[0035] The test methods for Examples 1, 5, 8, 4, 6, and 9 are as described above, and the results are shown in the appendix. Figure 4 , 5 As shown. By Figure 4 , 5 It can be seen that the adsorbents prepared in Examples 5 and 6 have a higher carbon dioxide adsorption capacity. That is, when the mass ratio of potassium carbonate to aluminum oxide is constant, the carbon dioxide adsorption capacity is maximized when the coating is applied twice.

[0036] For Examples 1, 4, 5, 6, 7, and 8, 9, the test methods were as described above, and the results are shown in the appendix. Figure 6 , 7 As shown in Figure 8. Figure 6 , 7 As shown in Figures 8 and 9, the adsorbents prepared in Examples 4, 6, and 9 have higher carbon dioxide adsorption capacities. That is, when the number of coating cycles is constant, the carbon dioxide adsorption capacity is greatest when the mass ratio of potassium carbonate to aluminum oxide is 4:3.

[0037] For Examples 10, 11, and 12, the test methods were as described above, and the results are shown in the appendix. Figure 9 , 10 As shown. By Figure 9 It is evident that adding phase change capsules can significantly improve the reactor bed temperature rise problem and increase the time it takes for the bed temperature to stabilize within the desired temperature range. Figure 10 It can be seen that adding phase change capsules can increase carbon dioxide adsorption. Combining the two figures, it can be concluded that PMMA as the capsule shell material has a better temperature control effect and a greater increase in carbon dioxide adsorption.

[0038] It should be noted that the above content merely illustrates the technical concept of the present invention and should not be construed as limiting the scope of protection of the present invention. For those skilled in the art, various improvements and modifications can be made without departing from the principle of the present invention, and all such improvements and modifications fall within the scope of protection of the claims of the present invention.

Claims

1. A method for preparing a phase change-potassium-based honeycomb CO2 composite adsorbent, characterized in that: Includes the following steps: (1) Dissolve potassium carbonate and aluminum oxide in a solvent in a certain mass ratio to form a viscous slurry; (2) Add a small amount of potassium hydroxide to the slurry to adjust the pH to alkaline, and then magnetically stir the slurry to form an adsorbent; (3) The adsorbent is attached to the wall of the honeycomb material, dried and then calcined; (4) After calcination, phase change capsules are added into the pores of the honeycomb material to obtain a composite adsorbent.

2. The preparation method of a phase change-potassium-based honeycomb CO2 composite adsorbent according to claim 1, characterized in that: In step (1), the mass ratio of potassium carbonate to aluminum oxide is 3-5:3, preferably 4:

3.

3. The preparation method of a phase change-potassium-based honeycomb CO2 composite adsorbent according to claim 1, characterized in that: in, In step (1), the solvent is deionized water.

4. The preparation method of a phase change-potassium-based honeycomb CO2 composite adsorbent according to claim 1, characterized in that: In step (2), the amount of potassium hydroxide added is 0.002g.

5. The preparation method of a phase change-potassium-based honeycomb CO2 composite adsorbent according to claim 1, characterized in that: in, In step (3), the adhesion method is a coating method.

6. The method for preparing a phase change-potassium-based honeycomb CO2 composite adsorbent according to claim 1, characterized in that: The coating is applied twice.

7. The method for preparing a phase change-potassium-based honeycomb CO2 composite adsorbent according to claim 1, characterized in that: in, In step (3), the honeycomb material is titanium dioxide.

8. The method for preparing a phase change-potassium-based honeycomb CO2 composite adsorbent according to claim 1, characterized in that: in, In step (4), the shell material of the phase change capsule is PMMA.

9. The method for preparing a phase change-potassium-based honeycomb CO2 composite adsorbent according to claim 1, characterized in that: in, In step (4), the phase change capsule is prepared by laboratory extrusion-spheronization.

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