High-heat-conductivity low-temperature carbon capture material, preparation method and application

Abstract

The invention provides a high-heat-conductivity low-temperature carbon capture material, and a preparation method and application thereof. The preparation method comprises the following steps: respectively drying potassium carbonate, aluminum oxide and graphite nanosheets; adding the dried potassium carbonate and aluminum oxide into a high-speed mixer for mixing to obtain uniform mixed powder; adding the mixed powder into a rolling granulator, rotating the mixed powder, adding the dried graphite nanosheets into the rolling granulator at a constant speed, and spraying deionized water as a binder in the adding process to obtain spherical particles; and drying the spherical particles at high temperature, cooling to room temperature, and screening to obtain the high-heat-conductivity low-temperature carbon capture material. According to the method, the graphite nanosheets are doped in the rolling granulation process to construct a heat-conducting network, so that the heat-conducting property of the material is remarkably improved, the desorption energy consumption is reduced, the desorption time is shortened, and matching of adsorption-desorption-cooling technological processes and continuous carbon capture are realized.

Description

Technical Field

[0001] This invention belongs to the field of low-temperature carbon capture technology and thermally conductive modified material preparation technology, specifically involving a high thermal conductivity low-temperature carbon capture material, its preparation method and application. Background Technology

[0002] With the advancement of global carbon neutrality goals, carbon capture, utilization, and storage (CCUS) technology has become one of the key supporting technologies for reducing industrial carbon emissions. Among them, low-temperature carbon capture technology has broad application prospects in industrial settings such as coal-fired power plants and steel mills due to its advantages such as low equipment investment and mild operating conditions. Potassium carbonate, as a typical low-temperature carbon capture adsorbent, has become one of the research hotspots in this field due to its high adsorption capacity for carbon dioxide, low cost, and environmental friendliness.

[0003] However, existing low-temperature carbon capture materials based on potassium carbonate face significant technical bottlenecks in engineering applications: First, they require high desorption temperatures, needing to reach above 220℃ in engineering practice to achieve effective desorption; second, the materials themselves have low thermal conductivity, resulting in a slow heating rate and thus prolonging the desorption time. This characteristic of "high desorption temperature + slow heating rate" makes it difficult to achieve time-series matching of the three core processes of adsorption, desorption, and cooling in the carbon capture process, making it impossible to achieve continuous and stable carbon capture operations.

[0004] To address these issues, existing technologies often employ increasing heating power to accelerate the heating rate. However, this leads to a significant increase in system energy consumption, substantially reducing the economic viability of carbon capture technology. Furthermore, while current research attempts to improve the structural stability of potassium carbonate adsorbents through composite carrier materials, it has not specifically optimized their thermal conductivity. Although high thermal conductivity materials such as graphite nanosheets have been applied to thermal conductivity modification in fields like electronics and energy storage, there are no reported technical solutions for doping and modifying them during the spheroidization and granulation process of potassium carbonate adsorbents to simultaneously achieve both shaping and enhanced thermal conductivity.

[0005] To address the aforementioned issues, it is necessary to propose a high thermal conductivity low-temperature carbon capture material with a reasonable design that effectively solves these problems, along with its preparation method and applications. Summary of the Invention

[0006] The present invention aims to solve at least one of the technical problems existing in the prior art, and to provide a high thermal conductivity low temperature carbon capture material, its preparation method and application.

[0007] One aspect of the present invention provides a method for preparing a high thermal conductivity, low-temperature carbon capture material, the method comprising: Potassium carbonate, aluminum oxide, and graphite nanosheets were dried separately. The dried potassium carbonate and aluminum oxide were added to a high-speed mixer and mixed to obtain a uniform mixed powder. The mixed powder is added to a spheroidizing granulator and rotated. At the same time, dried graphite nanosheets are added to the spheroidizing granulator at a uniform speed, and deionized water is sprayed as a binder during the addition process to obtain spherical particles. The spherical particles are dried at high temperature, cooled to room temperature, and then sieved to obtain a high thermal conductivity, low-temperature carbon capture material.

[0008] Optionally, the potassium carbonate has a mass percentage of 40% to 60%; the alumina has a mass percentage of 35% to 55%; and the graphite nanosheets have a mass percentage of 2% to 8%.

[0009] Optionally, potassium carbonate, alumina, and graphite nanosheets are dried separately, including: The potassium carbonate and the aluminum oxide were respectively placed in an oven at 80℃~120℃ and dried for 2h~4h. The graphite nanosheets were placed in a vacuum drying oven and dried at 60℃~80℃ for 1h~2h.

[0010] Optionally, the dried potassium carbonate and alumina are added to a high-speed mixer for mixing, including: Add the dried potassium carbonate and aluminum oxide to a high-speed mixer and mix at a speed of 1000r / min to 1500r / min for 10min to 20min.

[0011] Optionally, adding the mixed powder into a rounding granulator and rotating it includes: Add the mixed powder into the spheroidizing granulator, turn on the spheroidizing granulator and adjust the rotation speed to 200 r / min~400 r / min.

[0012] Optionally, the dried graphite nanosheets are added uniformly into a spheroidizing granulator, including: The dried graphite nanosheets are fed into the rounding granulator at a feeding rate of 5 g / min to 15 g / min.

[0013] Optionally, deionized water is sprayed as a binder during the addition process to obtain spherical particles, including: During the addition process, deionized water is sprayed as a binder, the material moisture content is controlled at 15%~25%, and the granulation time is 30min~60min, to obtain spherical particles with a particle size of 0.5mm~2mm.

[0014] Optionally, the spherical particles are subjected to high-temperature drying, including: The spherical particles were dried in an oven at 100℃~140℃ for 4h~6h.

[0015] Another aspect of the present invention provides a high thermal conductivity low-temperature carbon capture material, which is prepared by the high thermal conductivity low-temperature carbon capture material preparation method described above.

[0016] Another aspect of the present invention provides an application of a high thermal conductivity low-temperature carbon capture material, which is applied to CCUS; wherein the high thermal conductivity low-temperature carbon capture material is the high thermal conductivity low-temperature carbon capture material described above.

[0017] This invention relates to a high thermal conductivity, low-temperature carbon capture material, its preparation method, and its application. In this preparation method, graphite nanosheets are simultaneously doped during the spheroidizing granulation process, resulting in a uniform distribution of the nanosheets within the particles and the construction of a continuous thermally conductive network. This increases the material's thermal conductivity by 2-3 times compared to pure potassium carbonate-alumina composite materials, effectively accelerating the heating rate. The improved thermal conductivity shortens the desorption heating time by more than 30%, significantly reducing system heating energy consumption. Simultaneously, it achieves time-series matching of the adsorption-desorption-cooling process, ensuring continuous carbon capture operations. The introduction of the alumina carrier gives the material good mechanical strength, and the spherical particle shape is suitable for various industrial reactors such as fixed beds and fluidized beds. The spheroidizing granulation process ensures uniform particle size and reduces fluid resistance. The preparation process requires no additional complex equipment and can be scaled up using existing spheroidizing granulation production lines, reducing the cost of industrial transformation. Attached Figure Description

[0018] Figure 1 This is a schematic flowchart of a method for preparing a high thermal conductivity, low-temperature carbon capture material according to an embodiment of the present invention. Detailed Implementation

[0019] To enable those skilled in the art to better understand the technical solution of the present invention, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0020] To address the technical problems of existing potassium carbonate-based low-temperature carbon capture materials, such as low thermal conductivity, slow desorption heating, high energy consumption, and inability to operate continuously, Figure 1 As shown, one aspect of the present invention provides a method S100 for preparing a high thermal conductivity, low-temperature carbon capture material, the method comprising: S110. Potassium carbonate, aluminum oxide and graphite nanosheets are dried separately.

[0021] Specifically, the potassium carbonate and the alumina are dried in an oven at 80℃~120℃ for 2h~4h to remove moisture. The graphite nanosheets are dried in a vacuum drying oven at 60℃~80℃ for 1h~2h to prevent agglomeration.

[0022] In this step, potassium carbonate, aluminum oxide and graphite nanosheets are dried separately to ensure the uniformity of subsequent mixing and doping and improve the overall performance stability of the material.

[0023] S120. Add the dried potassium carbonate and aluminum oxide to a high-speed mixer and mix to obtain a uniform mixed powder.

[0024] Specifically, dry potassium carbonate and aluminum oxide are weighed out according to a mass percentage of 40%~60% and a mass percentage of 35%~55%, respectively. The potassium carbonate and aluminum oxide are added to a high-speed mixer and mixed at a speed of 1000r / min~1500r / min for 10min~20min to obtain a uniform mixed powder.

[0025] In this step, a high-speed mixing process is used to ensure that potassium carbonate and alumina are mixed uniformly, providing a uniform powder base for subsequent spheroidization and granulation, which is beneficial for the uniform doping of graphite nanosheets and the formation of a thermally conductive network.

[0026] S130. The mixed powder is added to a spheroidizing granulator and rotated. At the same time, the dried graphite nanosheets are added to the spheroidizing granulator at a uniform speed, and deionized water is sprayed as a binder during the addition process to obtain spherical particles.

[0027] Specifically, the mixed powder is added to a spheroidizing granulator, which is then turned on and its rotation speed is adjusted to 200 r / min to 400 r / min. Simultaneously, dried graphite nanosheets, weighed at 2% to 8% of their original weight, are added to the spheroidizing granulator at a uniform feeding rate of 5 g / min to 15 g / min. Deionized water is sprayed as a binder during the addition of the graphite nanosheets, and the material moisture content is controlled at 15% to 25%. The granulation time is 30 min to 60 min, resulting in spherical particles with a particle size of 0.5 mm to 2 mm.

[0028] This step breaks through the traditional technical approach of granulation followed by modification, directly doping graphite nanosheets during the spheroidization granulation process of the potassium carbonate-alumina adsorbent. This solves the problems of uneven dispersion and discontinuous thermal conductivity networks caused by the later addition of thermally conductive agents, achieving integrated molding and thermal conductivity modification. By controlling the rotation speed, feeding rate, humidity, and granulation time, particles with good sphericity and uniform particle size can be obtained, suitable for industrial reactors such as fixed beds and fluidized beds, reducing airflow resistance and improving mass transfer efficiency.

[0029] S140. The spherical particles are dried at high temperature, cooled to room temperature, and then sieved to obtain a high thermal conductivity low temperature carbon capture material.

[0030] Specifically, the spherical particles are dried in an oven at 100℃~140℃ for 4h~6h for high-temperature drying, cooled to room temperature, and then sieved to remove particles with unqualified particle size, thereby obtaining a high thermal conductivity low-temperature carbon capture material.

[0031] The present invention provides a method for preparing high thermal conductivity low-temperature carbon capture materials, breaking through the traditional technical path of granulation followed by modification. It directly incorporates graphite nanosheets during the spheroidization granulation process of the potassium carbonate-alumina adsorbent, solving the problems of uneven dispersion and discontinuous thermal conductivity networks caused by the later addition of thermally conductive agents. This achieves integrated molding and thermal conductivity modification. Precise control of the ratio of potassium carbonate, alumina, and graphite nanosheets creates a synergistic effect between the structural support of the carrier, the carbon dioxide capture effect of the adsorbent, and the heat transfer enhancement effect of the thermally conductive agent, balancing adsorption capacity and thermal conductivity. By improving thermal conductivity, the desorption temperature and heating time are reduced, avoiding the use of high-power heating equipment. Simultaneously, it solves the core bottleneck of mismatched adsorption-desorption-cooling sequences in existing processes, providing technical support for the engineering and continuous operation of low-temperature carbon capture technology.

[0032] Another aspect of the present invention provides a high thermal conductivity low-temperature carbon trapping material, which is prepared using the high thermal conductivity low-temperature carbon trapping material preparation method S100 described above. The specific process of this high thermal conductivity low-temperature carbon trapping material preparation method S100 has been described in detail above and will not be repeated here.

[0033] The high thermal conductivity low-temperature carbon capture material of the present invention is composed of the following components by mass percentage: potassium carbonate at a mass percentage of 40% to 60%, alumina at a mass percentage of 35% to 55%, and graphite nanosheets at a mass percentage of 2% to 8%; wherein, alumina serves as a carrier to provide structural support and pore channels, graphite nanosheets serve as a thermally conductive agent to construct a continuous thermally conductive network, and potassium carbonate serves as the core adsorption component.

[0034] The high thermal conductivity, low-temperature carbon capture material of this invention is prepared using the method described in the entire text. By doping graphite nanosheets during the spheroidization granulation process to construct a thermally conductive network, the thermal conductivity of the material is significantly improved, the desorption energy consumption and time are reduced, and the matching of the adsorption-desorption-cooling process flow and continuous carbon capture are achieved. By limiting the mass percentage of each component, it is ensured that potassium carbonate has sufficient adsorption capacity, alumina provides structural support and pore channels, and graphite nanosheets construct a highly efficient thermally conductive network in an appropriate proportion, thereby significantly improving thermal conductivity while ensuring adsorption performance.

[0035] The high thermal conductivity, low-temperature carbon capture material of this invention can be applied to CCUS (Carbon Capture by Adsorption). This material significantly improves thermal conductivity, reduces desorption energy consumption and time, and achieves matching and continuous carbon capture of the adsorption-desorption-cooling process. It is particularly suitable for carbon capture of medium- and low-temperature exhaust gases (such as flue gas) from coal-fired power plants and steel mills, requiring low equipment investment and operating under mild conditions. By improving carbon capture efficiency and continuity, it facilitates large-scale, low-cost CO2 capture in the industrial sector, accelerating the implementation of CCUS technology and the achievement of carbon neutrality goals. The high-purity CO2 obtained through rapid desorption can be promptly transported to utilization systems (such as synthetic fuels and chemicals) or storage facilities, improving the overall operational efficiency. Potassium carbonate, alumina, and graphite nanosheets are all environmentally friendly materials, free of toxic and harmful components, aligning with the development direction of green chemistry.

[0036] The specific process of the preparation method S100 for high thermal conductivity low temperature carbon capture material of the present invention will be described below with reference to specific embodiments.

[0037] Example 1 The high thermal conductivity low-temperature carbon capture material in this embodiment has the following composition and mass percentage: potassium carbonate 45%, alumina 50%, and graphite nanosheets 5%.

[0038] Preparation steps: 1) Raw material pretreatment: Potassium carbonate and aluminum oxide were dried in an oven at 100℃ for 3 hours; graphite nanosheets were dried in a vacuum drying oven at 70℃ for 1.5 hours.

[0039] 2) Premixing: Weigh 450g of potassium carbonate and 500g of aluminum oxide, add them to a high-speed mixer, and mix at 1200r / min for 15 minutes to obtain a uniformly mixed powder.

[0040] 3) Rounding granulation and thermal conductivity agent doping: Add the premixed powder to the rounding granulator, adjust the speed to 300 r / min, add 50g of graphite nanosheets at a rate of 10g / min through a quantitative feeding device, and spray deionized water to control the material humidity to 20% at the same time. The granulation time is 45 minutes to obtain spherical particles with a particle size of 0.5mm~2mm.

[0041] 4) Post-processing: Place the spherical particles in a 120℃ oven and dry for 5 hours. After cooling to room temperature, sieve to remove particles with a diameter less than 0.5 mm and greater than 2 mm to obtain a high thermal conductivity low temperature carbon capture material.

[0042] Performance testing: The high thermal conductivity low-temperature carbon capture material prepared in this embodiment has a thermal conductivity of 1.1 W / (m•K), which is 2.75 times higher than that of the undoped potassium carbonate-alumina composite material (thermal conductivity 0.4 W / (m•K)). At a desorption temperature of 195℃, the desorption time is 40 minutes, which is 35% shorter than that of the undoped sample, and continuous cycle operation of adsorption-desorption-cooling can be achieved.

[0043] Example 2 The high thermal conductivity low-temperature carbon capture material in this embodiment has the following composition and mass percentage: potassium carbonate 50%, alumina 45%, and graphite nanosheets 5%.

[0044] Preparation steps: 1) Raw material pretreatment: Potassium carbonate and aluminum oxide were dried in an oven at 110℃ for 2.5 hours; graphite nanosheets were dried in a vacuum drying oven at 65℃ for 2 hours.

[0045] 2) Premixing: Weigh 500g of potassium carbonate and 450g of aluminum oxide, add them to a high-speed mixer, and mix at 1400r / min for 12 minutes to obtain a uniformly mixed powder.

[0046] 3) Rounding granulation and thermal conductivity agent doping: The premixed powder is added to the rounding granulator and the rotation speed is adjusted to 350 r / min. 50g of graphite nanosheets are added at a rate of 12g / min through a quantitative feeding device. At the same time, deionized water is sprayed to control the material humidity to 22%. The granulation time is 40 minutes to obtain spherical particles with a particle size of 0.5mm~2mm.

[0047] 4) Post-processing: The spherical particles were dried in an oven at 130℃ for 4.5 hours, cooled to room temperature, and then sieved to obtain a high thermal conductivity low temperature carbon capture material.

[0048] Performance testing: In this embodiment, the thermal conductivity of the high thermal conductivity low temperature carbon capture material is 1.2 W / (m•K), which is 3 times higher than that of the undoped sample; at a desorption temperature of 200℃, the desorption time is 38 minutes, which is 38% shorter than that of the undoped sample.

[0049] Comparative example (undoped graphite nanosheets) The material composition is: 45% potassium carbonate and 55% alumina. The preparation steps are the same as in Example 1, except that graphite nanosheets are not added. Performance tests show that its thermal conductivity is 0.4 W / (m•K), and the desorption time at a desorption temperature of 220℃ is 62 minutes. This indicates that continuous matching of adsorption-desorption-cooling cannot be achieved, resulting in high system energy consumption.

[0050] In summary, the high thermal conductivity low temperature carbon capture material prepared by the method of the present invention has a thermal conductivity that is 2-3 times higher than that of pure potassium carbonate-alumina composite material, effectively accelerating the heating rate. The improved thermal conductivity shortens the desorption heating time by more than 30%, significantly reducing the system heating energy consumption, while achieving time-series matching of the adsorption-desorption-cooling process, ensuring continuous carbon capture operation.

[0051] It is understood that the above embodiments are merely exemplary implementations used to illustrate the principles of the present invention, and the present invention is not limited thereto. For those skilled in the art, various modifications and improvements can be made without departing from the spirit and essence of the present invention, and these modifications and improvements are also considered to be within the scope of protection of the present invention.

Claims

1. A method for preparing a high thermal conductivity, low-temperature carbon capture material, characterized in that, The preparation method includes: Potassium carbonate, aluminum oxide, and graphite nanosheets were dried separately. The dried potassium carbonate and aluminum oxide were added to a high-speed mixer and mixed to obtain a uniform mixed powder. The mixed powder is added to a spheroidizing granulator and rotated. At the same time, dried graphite nanosheets are added to the spheroidizing granulator at a uniform speed, and deionized water is sprayed as a binder during the addition process to obtain spherical particles. The spherical particles are dried at high temperature, cooled to room temperature, and then sieved to obtain a high thermal conductivity, low-temperature carbon capture material.

2. The preparation method according to claim 1, characterized in that, The potassium carbonate has a mass percentage of 40% to 60%; the alumina has a mass percentage of 35% to 55%; and the graphite nanosheets have a mass percentage of 2% to 8%.

3. The preparation method according to claim 1, characterized in that, Potassium carbonate, aluminum oxide, and graphite nanosheets were dried separately, including: The potassium carbonate and the aluminum oxide were respectively placed in an oven at 80℃~120℃ and dried for 2h~4h. The graphite nanosheets were placed in a vacuum drying oven and dried at 60℃~80℃ for 1h~2h.

4. The preparation method according to any one of claims 1 to 3, characterized in that, The dried potassium carbonate and aluminum oxide are added to a high-speed mixer for mixing, including: Add the dried potassium carbonate and aluminum oxide to a high-speed mixer and mix at a speed of 1000r / min to 1500r / min for 10min to 20min.

5. The preparation method according to any one of claims 1 to 3, characterized in that, Adding the mixed powder to a rounding granulator and rotating it includes: Add the mixed powder into the spheroidizing granulator, turn on the spheroidizing granulator and adjust the rotation speed to 200 r / min~400 r / min.

6. The preparation method according to any one of claims 1 to 3, characterized in that, The dried graphite nanosheets are added at a uniform rate into a spheroidizing granulator, including: The dried graphite nanosheets are fed into the rounding granulator at a feeding rate of 5 g / min to 15 g / min.

7. The preparation method according to any one of claims 1 to 3, characterized in that, During the addition process, deionized water is sprayed as a binder to obtain spherical particles, including: During the addition process, deionized water is sprayed as a binder, the material moisture content is controlled at 15%~25%, and the granulation time is 30 min~60 min to obtain spherical particles with a particle size of 0.5mm~2mm.

8. The preparation method according to any one of claims 1 to 3, characterized in that, The spherical particles are dried at high temperature, including: The spherical particles were dried in an oven at 100℃~140℃ for 4h~6h.

9. A high thermal conductivity, low-temperature carbon capture material, characterized in that, It is prepared by the method for preparing high thermal conductivity low temperature carbon capture material according to any one of claims 1 to 8.

10. The high thermal conductivity low-temperature carbon capture material of claim 9 is applied to CCUS.

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