Method for preparing carbon dioxide adsorption material from camellia seed shells
By pretreatment with the ternary eutectic solvent DES and activation with KOH, the problem of wasted camellia seed shell resources was solved, and a highly efficient carbon dioxide adsorption material was prepared, which improved CO2 adsorption performance and reduced costs.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- DALIAN INSTITUTE OF CHEMICAL PHYSICS CHINESE ACADEMY OF SCIENCES
- Filing Date
- 2024-11-21
- Publication Date
- 2026-05-22
AI Technical Summary
Biomass resources such as camellia seed shells have not been effectively utilized, leading to resource waste and environmental pollution. Existing porous carbon material preparation processes suffer from problems such as difficulty in removing mineral impurities, high costs, and poor adsorption performance.
Camellia seed shells were pretreated with the ternary eutectic solvent DES, and then activated with KOH. Nitrogen and oxygen atoms were embedded into the carbon skeleton of microalgae through the Maillard reaction to form a highly efficient carbon dioxide adsorption material.
This study has enabled the efficient preparation of high-performance carbon dioxide adsorbent materials, which increases CO2 adsorption capacity and surface functional group content, reduces preparation costs, and is environmentally friendly.
Abstract
Description
Technical Field
[0001] This application relates to a method for preparing carbon dioxide adsorbent material from camellia seed shells, belonging to the field of adsorbent materials. Background Technology
[0002] Over the past few decades, China has extensively developed the camellia oil industry, leading to its rapid growth. However, this has also resulted in the waste of biomass such as camellia seed meal and shells. If these are not recycled, they not only cause environmental pollution but also represent a waste of resources. Camellia seed shells have a high carbon content and numerous surface pores, making them suitable for preparing biomass carbon materials, such as carbon dioxide adsorption materials. Among common carbon dioxide adsorbents, porous carbon materials possess advantages such as high thermal stability, good chemical stability, low desorption temperature (<373K), and strong surface hydrophobicity, making them considered ideal adsorbents. Based on their preparation process, they can be categorized into: traditional activated carbon, biomass-derived carbon, polymer-derived carbon, and graphite carbon. Traditional activated carbon is prepared using coal tar pitch as a carbon precursor, but mineral impurities are difficult to remove, affecting the structure and resulting in poor adsorption performance. Polymers offer better performance but are costly and unsuitable for industrial production. Biomass-derived porous carbon materials, on the other hand, have advantages such as wide availability, renewability, low cost, environmental friendliness, and simple preparation processes, making them a key research focus in current porous carbon material research. Studies have found that a lower KOH / char ratio and activation temperature are beneficial for increasing the volume of ultramicropores, thereby achieving high CO2 adsorption performance. Secondly, specific surface area and oxygen-containing functional groups on the surface are also important factors affecting CO2 adsorption. The coexistence of high specific surface area, high micropore porosity, and oxygen-containing functional groups on the surface achieves efficient CO2 adsorption. Summary of the Invention
[0003] This application provides a novel solvent that combines high processing capacity with environmental friendliness. Utilizing the eutectic solvent DES as a solvent pretreatment method for biomass precursors, it promotes the interactive polymerization of proteins and carbohydrates under hydrothermal conditions via Maillard reactions, embedding nitrogen and oxygen atoms into the microalgal carbon framework to inhibit nitrogen and oxygen loss and forming abundant nitrogen and oxygen functional groups. This provides a new approach for the research and preparation of carbon dioxide adsorbent materials from camellia seed shells, and can be used for the efficient pretreatment of camellia seed shells.
[0004] According to one aspect of this application, a method for preparing carbon dioxide adsorbent material from camellia seed shells is provided, comprising the following steps:
[0005] (1) Mix camellia seed shells with a ternary eutectic solvent, react and stir to obtain a solid substance;
[0006] (2) The solid material is pre-carbonized, then mixed with KOH, ground, and carbonized to obtain the carbon dioxide adsorbent material.
[0007] The ternary eutectic solvent is obtained through the following steps:
[0008] Betaine, N,N-dimethylurea and propylene glycol are mixed and heated to obtain the ternary eutectic solvent;
[0009] The molar ratio of betaine, N,N-dimethylurea and propylene glycol is 1:1:3 to 1:1:5;
[0010] The heating temperature is 60–100°C;
[0011] The heating time is 60 to 100 minutes;
[0012] The solid-liquid ratio of the camellia seed shell to the ternary eutectic solvent is 1:15 to 1:45 g / ml;
[0013] The reaction temperature is 60–100°C;
[0014] The reaction time is 60–100 min;
[0015] The stirring speed is 400-500 rpm.
[0016] The pre-carbonization temperature is 700–900°C;
[0017] The pre-carbonization time is 1 to 2 hours.
[0018] The mass ratio of the solid substance to KOH is 1:2.
[0019] The carbonization temperature is 700–900°C;
[0020] The carbonization time is 1 to 2 hours.
[0021] The camellia seed shells are selected from waste camellia seed shells and ground through a 60-mesh sieve.
[0022] Optionally, the following steps are included:
[0023] Synthesis of DES: Betaine was used as a hydrogen bond acceptor and mixed with N,N-dimethylurea and propylene glycol, two hydrogen bond donors, in a molar ratio of 1:1:5. The mixture was heated and stirred to prepare a solvent. The synthesis was complete when the final solution was clear and transparent.
[0024] Pretreatment of rapeseed hulls: The prepared ternary eutectic solvent is heated and stirred with camellia seed hull powder. Through strong hydrogen bonding, waste camellia seed hulls are efficiently treated. After the treatment, the precipitate is collected by centrifugation and dried at 110℃.
[0025] Pre-carbonization: The rapeseed hulls after DES treatment are collected as filter residue and carbonized at high temperature in a tubular furnace.
[0026] Activation carbonization: The obtained pre-carbonized product is ground and mixed with KOH at a mass ratio of 1:2, and then placed back into a tube furnace for carbonization at the same temperature as the pre-carbonization. Too low a temperature may result in insufficient KOH decomposition and fewer micropores formed; too high a temperature may cause micropore collapse, affecting performance.
[0027] (1) Determination of carbon dioxide adsorption capacity: The amount of CO2 adsorbed by the sample under 273K (0℃) conditions. Before measurement, the sample was degassed in a vacuum environment at 200℃ for 4 hours until it stabilized, and then cooled to 273K for corresponding CO2 adsorption. High-purity CO2 was introduced to obtain adsorption isotherms in the range of 0.001 to 1 bar. The adsorption performance was evaluated by the amount of CO2 adsorbed per gram of sample within the pressure range.
[0028] The beneficial effects that this application can produce include:
[0029] A novel ternary reagent for treating camellia seed shells is disclosed to promote the doping reaction of heteroatoms in the shells. Subsequently, under high-temperature carbonization conditions, a new method for efficiently preparing high-performance carbon dioxide adsorbent carbon materials is provided. Detailed Implementation
[0030] The present application is described in detail below with reference to the embodiments, but the present application is not limited to these embodiments.
[0031] Unless otherwise specified, the raw materials and reagents used in the embodiments of this application were all purchased commercially.
[0032] The analysis method in the embodiments of this application is as follows:
[0033] Carbon dioxide adsorption capacity determination: Carbon dioxide adsorption capacity was determined and analyzed using a multi-station extended fully automated specific surface area and porosity analyzer (Micromeritics ASAP 2460).
[0034] Example 1
[0035] Synthesis of ternary DES: 117.1 g of betaine, 88.1 g of N,N-dimethylurea, and 380.5 g of propylene glycol were heated and stirred at 60 °C until a clear and transparent liquid was obtained. In a round-bottom flask, 10 g of oven-dried camellia seed shell powder and 350 ml of ternary DES extraction reagent were added. The mixture was reacted at 85 °C for 65 min at 500 rpm. After the reaction, the residue was collected, dried at 110 °C, and 3 g was pre-carbonized at 900 °C. After cooling, the pre-carbonized product was ground and mixed with KOH at a mass ratio of 1:2, and then placed in a tube furnace for further carbonization at 900 °C. CO2 adsorption curves were then measured, and the CO2 adsorption capacity was calculated. CO2 adsorption capacity: 5.76 mmol / g.
[0036] Example 2
[0037] Synthesis of ternary DES: 117.1 g of betaine, 88.1 g of N,N-dimethylurea, and 380.5 g of propylene glycol were heated and stirred at 60 °C until a clear and transparent liquid was obtained. In a round-bottom flask, 10 g of oven-dried camellia seed shell powder and 350 ml of ternary DES extraction reagent were added. The mixture was reacted at 85 °C for 65 min at 500 rpm. After the reaction, the residue was collected, dried at 110 °C, and 3 g was pre-carbonized at 700 °C. After cooling, the pre-carbonized product was ground and mixed with KOH at a mass ratio of 1:2, and then placed in a tube furnace for further carbonization at 700 °C. CO2 adsorption curves were then measured, and the CO2 adsorption capacity was calculated. CO2 adsorption capacity: 6.20 mmol / g.
[0038] Example 3
[0039] 3g of camellia seed shell raw material was pre-carbonized at 900℃. After cooling, the pre-carbonized product was ground and mixed with KOH at a mass ratio of 1:2, and then placed in a tube furnace for high-temperature carbonization at 900℃. CO2 adsorption curve was then measured, and the CO2 adsorption capacity was calculated. CO2 adsorption capacity: 5.43mmol / g.
[0040] Example 4
[0041] Synthesis of ternary DES: 117.1 g of betaine, 88.1 g of N,N-dimethylurea, and 380.5 g of propylene glycol were heated and stirred at 60 °C until a clear and transparent liquid was obtained. In a round-bottom flask, 10 g of oven-dried camellia seed shell powder and 350 ml of ternary DES extraction reagent were added. The mixture was reacted at 85 °C for 65 min at 500 rpm. After the reaction, the residue was collected, repeatedly washed, and dried at 110 °C. 3 g of the residue was pre-carbonized at 900 °C. After cooling, the pre-carbonized product was ground and mixed with KOH at a mass ratio of 1:2. The mixture was then placed in a tube furnace and carbonized again at 900 °C. CO2 adsorption curves were then measured, and the CO2 adsorption capacity was calculated. CO2 adsorption capacity: 5.64 mmol / g.
[0042] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.
Claims
1. A method for preparing carbon dioxide adsorbent material from camellia seed shells, characterized in that, Includes the following steps: (1) Mix camellia seed shells with a ternary eutectic solvent, react, stir, and obtain a solid substance; (2) The solid material is pre-carbonized, then mixed with KOH, ground, and carbonized to obtain the carbon dioxide adsorption material.
2. The method according to claim 1, characterized in that, The ternary eutectic solvent is obtained through the following steps: Betaine, N,N-dimethylurea and propylene glycol are mixed and heated to obtain the ternary eutectic solvent; The molar ratio of betaine, N,N-dimethylurea and propylene glycol is 1:1:3 to 1:1:5; The heating temperature is 60–100°C; The heating time is 60 to 100 minutes.
3. The method according to claim 1, characterized in that, The solid-liquid ratio of the camellia seed shell to the ternary eutectic solvent is 1:15 to 1:45 g / ml; The reaction temperature is 60–100°C; The reaction time is 60–100 min; The stirring speed is 400-500 rpm.
4. The method according to claim 1, characterized in that, The pre-carbonization temperature is 700–900°C; The pre-carbonization time is 1 to 2 hours.
5. The method according to claim 1, characterized in that, The mass ratio of the solid substance to KOH is 1:
2.
6. The method according to claim 1, characterized in that, The carbonization temperature is 700–900°C; The carbonization time is 1 to 2 hours.