Carbon reduction system

Abstract

A closed-loop system for reducing carbon dioxide to solid carbon includes a reactor vessel where gaseous carbon dioxide is sparged into reagents, producing a mixture of carbon and metal oxide. The system comprises a separator tank to separate the carbon from the metal oxide, a regenerator to convert the metal oxide back to liquid metal or chemical mixture, and a purifier to further purify the carbon. The reagents are continuously recycled within the system, allowing for efficient carbon reduction and the production of high-purity carbon materials, such as graphene.

Description

Carbon Reduction SystemField of the Invention

[0001] This disclosure pertains to a carbon converter system and methods for converting carbon dioxide into solid carbon material. Specifically, it concerns a closed-loop system that utilises liquid metal, alloy or other chemical mixtures, either combined or used separately. The carbon converter system can be tuned to accommodate both liquid metal alloys or chemical mixtures and reagents to facilitate the reduction of carbon dioxide into high-purity carbon materials, such as graphene, carbon nanotubes while continuously regenerating the liquid metal alloys and chemical mixtures for repeated use. The liquid metal alloys may include indium, gallium, tin, aluminium, zinc, and other metals and alloys that are liquid below 700- 800 degrees Celsius. The chemical mixtures may include aqueous amines ionic liquids, carbonate / bicarbonate salts such as potassium carbonate or sodium carbonate, polyalkylene glycol, organic solvents like dimethylformamide and dimethyl sulfoxide, molten salts, and other chemicals that are typically heated between 50°C and 500°C which absorb CO2Background of the Invention

[0002] The rise in atmospheric carbon dioxide (CO2) levels is a significant environmental concern, driving the demand for innovative solutions to reduce CO2emissions. Current methods to address CO2emissions include a variety of chemical and physical processes aimed at capturing and utilising CO2in different forms. These methods vary in efficiency, cost, and environmental impact. The exploration of new technologies that can effectively reduce CO2and convert it into useful carbon-based materials remains an ongoing area of research and development. There is a continuing need for systems and methods that can address these challenges in a manner that is both economically viable and environmentally sustainable.

[0003] It is to be understood that, if any prior art information is referred to herein, such reference does not constitute an admission that the information forms part of the common general knowledge in the art, in Australia or any other country.Summary of the Disclosure

[0004] There is provided herein a closed-loop carbon reduction system designed to efficiently convert gaseous carbon dioxide into solid carbon using liquid metal alloys and / or chemical mixtures as the reactive medium. The system can operate in both batch and continuous process modes, allowing the liquid metal alloys and chemical mixtures to be recycled without the need for external replenishment. The primary components include reactor vessel reactor vessel, a separator tank, a regenerator, and a purifier, which work together to facilitate the necessary chemical reactions and separations for carbon reduction and regeneration of the reactive medium.

[0005] Within the reactor vessel reactor vessel, carbon dioxide is sparged into a bath of liquid metal alloy and / or chemical mixture, where it reacts to produce solid carbon material and metal oxide. The mixture of solid carbon and metal oxide or chemical mixture is then transported to the separator tank, where the solid carbon is separated from the metal oxide or chemical mixture. The metal oxide, dissolved or suspended in the liquid metal alloy, is directed to the regenerator, where it undergoes a reduction process, such as electrowinning, to restore the metal to its liquid state. Chemical mixtures are washed through the purifier to restore their reactive state. The regenerated liquid metal alloy and chemical mixture are cycled back into the reactor vessel reactor vessel, ensuring the system operates continuously in a closed-loop configuration.

[0006] The purifier processes the solid carbon to produce high-purity carbon products such as graphene, carbon nanotubes, and other carbon-based materials. Purification methods may involve treatments with bases or acids to remove residual metal oxides or other contaminants, or mechanical separation techniques to eliminate non- carbonaceous residues. The system can control the production of carbon monoxide during gallium oxide reduction by adjusting the temperature between 25°C and 800°C, which allows the decomposition of carbon monoxide into carbon and oxygen.

[0007] Liquid metal alloys, including indium, gallium, tin, aluminium, zinc, and other metals or alloys that remain liquid below 700-800°C, are identified as effective reactive mediums due to their ability to react with carbon dioxide. Chemical mixtures such as aqueous amines, ionic liquids, carbonate / bicarbonate salts, polyalkyleneglycol, organic solvents, and molten salts heated between 50 °C and 500°C, which absorb CO2, are also considered suitable for the system. The system is optimised for sustainability and efficiency, minimising waste and reducing the need for external resources while producing valuable carbon materials.

[0008] According to one aspect, there is provided a closed-loop carbon reduction system comprising a reactor vessel into which gaseous carbon dioxide is sparged into a reactive medium, the reactor vessel having a gas inlet, an upper outlet, and a lower inlet, the system further comprising a separator tank configured with a separator across which carbon and oxide are divided into respective outlets, a regenerator arranged to regenerate oxide into a reactive medium, and a purifier arranged to purify carbon.

[0009] Preferably, the reactive medium may comprise either a liquid metal or a chemical mixture. In some embodiments, the reactor vessel, separator tank, and regenerator together form a closed-loop through which the reactive medium is recycled without replenishment.

[0010] Optionally, the reactive medium includes one or more of aqueous amines, ionic liquids, carbonate or bicarbonate salts, polyalkylene glycol, organic solvents, or molten salts.

[0011] In other embodiments, the reactive medium is a liquid metal such as indium, gallium, tin, aluminium, zinc, or any other liquid metal remaining liquid below about 700-800°C.

[0012] Preferably, the oxide formed during reaction may comprise gallium oxide.

[0013] In certain embodiments, regeneration of the oxide is carried out using a reductant gas, for example hydrogen, methane, or other hydrocarbons.

[0014] Alternatively, the oxide may be regenerated by electrowinning in which the oxide is dissolved in an alkaline solution, heated, and subjected to electrolysis.

[0015] In embodiments where gallium oxide is reduced, oxygen may be released as a by-product of the regeneration.

[0016] Optionally, the purifier is arranged to wash the separated carbon with a base solution to remove residual oxides.

[0017] In other embodiments, the purification process may include mechanical separation techniques such as sieving or filtration.

[0018] In some forms, the separator tank separates carbon from the reactive medium by the use of acids, alkalines, or electrolysis.

[0019] Preferably, the carbon produced includes graphene, carbon nanotubes, or related nanostructured allotropes.

[0020] In further embodiments, regeneration of chemical mixtures is achieved by heating to a temperature between 50°C and 500°C or by applying a vacuum to desorb absorbed carbon dioxide.

[0021] According to another aspect, there is provided a method of reducing carbon dioxide to solid carbon in a closed-loop system, the method including introducing gaseous carbon dioxide into a reactor vessel containing a reactive medium, separating the resultant carbon and oxide, regenerating the oxide into reactive medium, recycling the regenerated reactive medium back into the reactor vessel, and purifying the separated carbon.

[0022] Preferably, the reactive medium is chosen from liquid metals or chemical mixtures.

[0023] In certain embodiments, the purification step includes washing the carbon with a base solution or performing mechanical separation.

[0024] Optionally, the reactive medium comprises one or more of aqueous amines, ionic liquids, carbonate or bicarbonate salts, polyalkylene glycol, organic solvents, or molten salts.

[0025] In other embodiments, the reactive medium is a liquid metal such as gallium, indium, tin, or aluminium.

[0026] Preferably, where chemical mixtures are employed, regeneration is achieved by heating the mixture to between 50°C and 500°C or applying a vacuum to desorb absorbed carbon dioxide.

[0027] Other aspects of the invention are also disclosed.Brief Description of the Drawings

[0028] Notwithstanding any other forms which may fall within the scope of the present invention, preferred embodiments of the disclosure will now be described, by way of example only, with reference to the accompanying drawings in which:

[0029] Figure 1 shows a closed-loop carbon reduction system comprising a reactor vessel, a separator tank, a regenerator, and a purifier. The figure illustrates the flow of gaseous carbon dioxide through the system, the conversion of the gas into solid carbon and metal oxide or chemical mixtures in the reactor vessel, the separation process in the separator tank, the regeneration of the reactive medium in the regenerator, and the purification of the carbon product in the purifier.Description of Embodiments

[0030] Figure 1 shows a closed-loop carbon reduction system 100, specifically designed to reduce gaseous carbon oxides, such as carbon dioxide (CO2), to solid carbon using a liquid metal (which may include a liquid metal alloy) or chemical mixtures as the reactive medium. This system 100 operates in a closed-loop configuration, allowing the liquid metal or chemical mixtures to be continuously recycled without the need for external replenishment. The system 100 is particularly well-suited for producing high-purity carbon products such as graphene and carbon nanotubes while also efficiently regenerating the reactive medium for repeated use. The system 100 comprises several key components, including a reactor vessel 101 , a separator tank 105, a regenerator 110, and a purifier 113, which work in concert to facilitate the chemical reactions and subsequent separations necessary to achieve the desired carbon reduction and medium regeneration.

[0031] The reactor vessel 101 is where the primary chemical reaction occurs, converting gaseous carbon oxide into solid carbon and metal or chemical oxide. The reactor vessel 101 is designed to receive gaseous carbon oxide through a reactor gas inlet 102. This gaseous carbon oxide is sparged into the liquid metal or chemical mixture within the reactor vessel 101 , where it undergoes a chemical reaction to produce solid carbon and metal or chemical oxide. The reactive medium serves both as a reactant and a medium for the reaction. The design of the reactor vessel 101 ensures that the products of the reaction, namely the solid carbon and metal orchemical oxide, are carried upward through the reactor, driven by the flow of the sparged gas. These reaction products exit the reactor vessel 101 through a reactor upper outlet 103. The design of the reactor vessel 101 also includes a reactor lower inlet 104, positioned below the upper outlet 103, through which the regenerated reactive medium is reintroduced into the reactor, thereby maintaining a continuous cycle of reaction and regeneration within the system 100.

[0032] The separator tank 105 is connected to the reactor vessel 101 and is configured to separate the carbon from the metal or chemical oxide. The mixture of solid carbon and metal or chemical oxide that exits the reactor vessel 101 through the reactor upper outlet 103 is introduced into the separator tank 105 via a separator tank inlet 106. Inside the separator tank 105, the mixture encounters a separator 109, which is strategically positioned to allow the metal or chemical oxide (and any liquid medium) to pass through while retaining the solid carbon. The separator 109 facilitates the separation process by allowing the metal or chemical oxide to flow with the reactive medium toward the separator tank liquid outlet 107. The reactive medium, carrying the dissolved or suspended metal or chemical oxide, is then directed from the separator tank 105 to the regenerator 110 through the separator tank liquid outlet 107. Concurrently, the solid carbon is conveyed across the separator 109 to the separator tank solid outlet 108, from where it is collected and subsequently transferred to the purifier 113 for further processing.

[0033] In the regenerator 110, the process begins by separating the metal or chemical oxide and carbon mixture from the separator tank 105. The mixture is then added to an alkaline solution, such as sodium hydroxide (NaOH) with a concentration ranging from 3 mol / L to 21 mol / L, equivalent to 0.00001 weight percentage to 99.99999 weight percentage, although other alkaline solutions may also be used. For example 3 mol KOH+ 3 mol NaOH would also be suitable. Some acids may work for this purpose. The solution is then heated to a temperature range of approximately 30- 150°C while being mixed. After the heating and mixing process, the solids, including the carbon, and any remaining reactive medium are separated from the solution by filtration. The clear solution, now primarily containing dissolved metal or chemical oxide, is transferred to an electrolyser.

[0034] Within the electrolyser, the solution is further heated to approximately 45°C using a heating rod to maintain the optimal temperature for electrolysis. The electrolyser is set up with a platinum plate as the counter electrode and a tungsten mesh as the working electrode, although other suitable metals may also be used depending on availability and specific requirements. A voltage of 0.00001 V to 24 V is applied across the electrodes, with a current ranging from 0.01 A to 30 A. These values can be adjusted depending on the number of cells in series or parallel and the size of the electrodes.

[0035] The reactive medium, regenerated from the metal or chemical oxide, collects at the bottom of the electrolyser. The reactive medium is then filtered to remove any solid particles that may have formed during the electrolysis process. After filtration, the reactive medium is reintroduced into the reactor vessel 101 through the regenerator outlet 112, completing the regeneration process. The electrolyser is then refilled with fresh alkaline solution (3 M to 21 M) as new mixtures of metal or chemical oxide and carbon are added for continuous processing.

[0036] The purifier 113 is designed to purify the solid carbon product, with particular efficacy in the production of high-purity graphene, carbon nanotubes, and other carbon materials. The solid carbon, which has been separated from the metal or chemical oxide in the separator tank 105, is introduced into the purifier 113 through a purifier inlet 114. Within the purifier 113, the carbon undergoes various purification processes depending on the specific requirements of the final product. These processes may include treatment with an aqueous base, such as sodium hydroxide, to dissolve any residual metal or chemical oxides and facilitate the separation of purified carbon from the solution. Alternatively, the carbon may be subjected to mechanical separation techniques, such as sieving or filtration, to remove non- carbonaceous residues, further enhancing the purity of the carbon product. The purification process is a multi-step procedure, involving several stages to ensure the highest quality of the final carbon product. Once purified, the carbon is discharged from the purifier 113 through a purifier outlet 115, resulting in a high-quality carbon material suitable for various industrial applications.

[0037] In a preferred embodiment, the reactive medium used in the closed-loop carbon reduction system 100 is gallium or chemical mixtures. Gallium is particularly suitable for this application due to its low melting point, non-toxicity, and its ability to effectively react with gaseous carbon oxides, such as carbon dioxide, to form gallium oxide. The chemical reactions involving gallium within the system 100 convert carbon dioxide into solid carbon while simultaneously regenerating the liquid gallium for continuous use in the system. Similarly, chemical mixtures such as aqueous amines, ionic liquids, carbonate / bicarbonate salts, polyalkylene glycol, organic solvents, and molten salts can be used as effective reagents for CO2absorption and conversion into carbon products.

[0038] When carbon dioxide is introduced into the reactor vessel 101 through the reactor gas inlet 102, it is sparged into the liquid gallium or chemical mixtures contained within the reactor. The primary chemical reaction occurring in the reactor vessel 101 can be represented by the following equation 2 Ga + xC022GaOx+ xC where 0 < x < 1 .5

[0039] In this reaction, carbon dioxide reacts stoichiometrically with the liquid gallium to produce solid carbon and gallium oxide. The carbon precipitates out as a solid product, while the gallium oxide forms within the reactive medium. The solid carbon and gallium oxide are carried upwards within the reactor vessel 101 and exit through the reactor upper outlet 103 as a mixture.

[0040] This mixture is then directed into the separator tank 105 through the separator tank inlet 106. In the separator tank 105, the mixture encounters the separator 109, where the solid carbon is separated from the gallium oxide and liquid gallium or chemical mixtures. The gallium oxide, now dissolved or suspended in the liquid gallium or chemical mixtures, flows through the separator 109 and exits the separator tank 105 via the separator tank liquid outlet 107, which leads to the regenerator 110.

[0041] In the regenerator 110, the gallium oxide or chemical mixtures undergo a reduction reaction to regenerate the liquid gallium or chemical reagents. This reduction process can be facilitated by a reductant gas such as hydrogen, methane, or other hydrocarbons. Additionally, the regenerator 110 can utilise electrowinning as an alternative method of reduction. In the electrowinning process, the gallium oxideor chemical mixture is added to an alkaline solution, heated, and subjected to electrolysis. The preferred reduction reaction using hydrogen gas can be described by the following equation: GaOx+ xH2— » Ga + xH2O where 0 < x < 1 .5I n this reaction, gallium oxide is reduced by hydrogen gas to regenerate elemental gallium and produce water as a by-product. Alternatively, in the electrowinning process, the gallium oxide or chemical mixtures are reduced to liquid gallium or their respective chemicals through electrolysis, and the oxygen produced during the reduction is released as a by-product. The regenerated liquid gallium or chemical mixture is then reintroduced into the reactor vessel 101 through the regenerator outlet 112, allowing the system 100 to maintain a continuous cycle of carbon dioxide reduction and gallium or chemical regeneration without the need for external replenishment of the reactive medium.

[0042] The solid carbon that is separated in the separator tank 105, typically comprising graphene, carbon nanotubes, or similar high-purity carbon materials, is transferred to the purifier 113 through the separator tank solid outlet 108. In the purifier 113, the carbon may undergo further processing to remove any residual gallium oxide or chemical impurities. For instance, the carbon can be treated with sodium hydroxide (NaOH) to dissolve any remaining gallium oxide or chemical residues. This reaction results in the formation of gallium hydroxide, which is soluble in the alkaline solution, leaving behind purified carbon. The purification process may also include mechanical separation techniques, such as sieving or filtration, to ensure the highest quality of the final carbon product.

[0043] In another preferred embodiment, chemical mixtures are used as the reactive medium in the system 100 for CO2absorption and conversion into carbon products. After CO2absorption, the chemical mixture may be washed with water or an organic solvent to remove impurities and residual carbon products. Regeneration is then achieved by heating the chemical mixture to temperatures between 50°C to 500°C or by applying a vacuum to desorb the absorbed CO2through the wash and purifier 113. The most effective chemical mixtures for this process include aqueous amines, ionic liquids, carbonate / bicarbonate salts, polyalkylene glycol, organic solvents, and molten salts, which absorb CO2and facilitate its conversion into carbon products.These chemical mixtures are engineered to work in unison, facilitating the necessary reactions and separations for carbon reduction when heated between 50°C and 500°C.

[0044] Upon CO2injection into the reactor vessel 101 , the chemical mixture aids in converting CO2into a carbon product, which passes through the separator tank 106, continues to the separator tank solid outlet 108, and is separated in the separator tank 105 before being routed to the purifier 113. In the purifier 113, the carbon undergoes further processing to remove any residual chemical impurities. The chemical mixture is purified and regenerated for continuous use, leaving a high- quality carbon byproduct. These chemical mixtures allow for efficient CO2capture and regeneration with minimal loss, making them ideal for repeated cycles.

[0045] In a specific example, a closed-loop carbon reduction system as described herein was constructed using gallium as the reactive medium. The reactor vessel was charged with 5 kg of liquid gallium maintained at 35°C above its melting point. Carbon dioxide gas of 99.9% purity was introduced through the reactor gas inlet at a pressure of 1.2 bar and a flow rate of 200 mL / min, sparged through a fine-pore diffuser to generate uniform bubbles with an average diameter of approximately 1 mm. Under these conditions, the carbon dioxide reacted with the gallium to produce gallium oxide and precipitated solid carbon. After 4 hours of continuous operation, analysis showed a conversion rate of approximately 85% of the introduced carbon dioxide into solid carbon, with the remainder primarily exiting as unreacted CO2and trace amounts of carbon monoxide (less than 2% of the inlet flow). Approximately 22 g of carbon product was collected in this run.

[0046] The effluent mixture passed from the reactor upper outlet into the separator tank, where it encountered a sintered ceramic separator element having a pore size of 5 pm. The carbon particles were retained on the upstream side and transferred to the purifier through the separator tank solid outlet, while gallium oxide dissolved in the gallium flowed through the separator into the liquid outlet.

[0047] The regenerator received the oxide-laden gallium and introduced it into a 5 M sodium hydroxide solution maintained at 60°C. The solution was subjected to electrowinning in a cell equipped with a tungsten mesh cathode and platinum anode,operating at 2.5 V and 10 A for 2 hours. This process reduced gallium oxide back to elemental gallium, which was separated by filtration and recycled into the reactor vessel through the reactor lower inlet. Oxygen was observed and quantified as a byproduct at the anode at a rate consistent with the stoichiometry of the gallium oxide reduction.

[0048] The retained carbon was transferred to the purifier, where it was treated with 1 M sodium hydroxide solution at 70°C for 30 minutes to dissolve residual gallium oxide. The purified carbon, predominantly comprising graphene flakes and nanotube structures, was recovered by filtration, washed with deionised water, and dried at 120°C.

[0049] In a comparative embodiment, a chemical mixture of 30 wt% monoethanolamine in water combined with 10 wt% sodium carbonate was used as the reactive medium in place of gallium. The reactor vessel was maintained at 90°C, and carbon dioxide was sparged at 0.5 bar and 150 mL / min. The amine solution absorbed the carbon dioxide, facilitating formation of carbamate species and release of carbon particulates. After 6 hours of operation, approximately 70% of the carbon dioxide was converted to solid carbon with the balance released as unreacted CO2and minor carbonate by-products. The separator tank employed centrifugation at 3,000 rpm for 20 minutes to separate solid carbon from the solution. The amine solution was then regenerated by heating to 120°C under 0.8 bar vacuum to release absorbed CO2and restore its reactive capacity. The carbon was purified by washing with ethanol to remove traces of amine and carbonate salts, and then dried to yield a high-purity carbon powder.

[0050] The foregoing description, for purposes of explanation, used specific nomenclature to provide a thorough understanding of the invention. However, it will be apparent to one skilled in the art that specific details are not required in order to practise the invention. Thus, the foregoing descriptions of specific embodiments of the invention are presented for purposes of illustration and description. They are not intended to be exhaustive or to limit the invention to the precise forms disclosed as obviously many modifications and variations are possible in view of the above teachings. The embodiments were chosen and described in order to best explain theprinciples of the invention and its practical applications, thereby enabling others skilled in the art to best utilize the invention and various embodiments with various modifications as are suited to the particular use contemplated. It is intended that the following claims and their equivalents define the scope of the invention.

Claims

Claims1. A closed-loop carbon reduction system comprising: a reactor vessel wherein gaseous carbon dioxide is sparged into a reactive medium, the reactor vessel having: a reactor gas inlet configured to receive the gaseous carbon dioxide; a reactor upper outlet from which a mixture of carbon and oxide exits the reactor; a reactor lower inlet, below the upper outlet; a separator tank having: a separator tank inlet operably interfacing the reactor upper outlet; a separator tank liquid outlet; a separator tank solid outlet; a separator interfacing the separator tank inlet, across which the mixture flows, through which the oxide flows to the separator tank liquid outlet, and across which the carbon is conveyed to the separator tank solid outlet; a regenerator wherein the oxide is regenerated to a reactive medium, the regenerator having: a regenerator inlet operably interfacing the separator tank liquid outlet; and a regenerator outlet operably interfacing the reactor lower inlet; a purifier wherein the carbon is purified, the purifier having: a purifier inlet operably interfacing the separator tank solid outlet; and a purifier outlet from which purified carbon is taken.

2. The system according to claim 1 , wherein the reactive medium comprises a liquid metal or chemical mixture.

3. The system according to claim 1 , wherein the reactor vessel, separator tank, and regenerator form a closed-loop through which the reactive medium is recycled in the system without replenishment.

4. The system according to claim 2, wherein the reactive medium comprises at least one of aqueous amines, ionic liquids, carbonate / bicarbonate salts, polyalkylene glycol, organic solvents, or molten salts.

5. The system according to claim 2, wherein the reactive medium is a liquid metal, comprising indium, gallium, tin, aluminium, zinc, or any liquid metal that is liquid below 700-800 degrees Celsius.

6. The system according to claim 5, wherein the metal oxide comprises gallium oxide.

7. The system according to claim 1 , wherein the oxide is regenerated to a reactive medium by reducing the oxide back to its active form using a reductant gas selected from the group consisting of hydrogen, methane, or other hydrocarbons.

8. The system according to claim 7, wherein the oxide is regenerated by electrowinning, wherein the oxide is dissolved in an alkaline solution, heated, and subjected to electrolysis.

9. The system according to claim 5, wherein the regenerator produces oxygen as a by-product during the reduction of gallium oxide.

10. The system according to claim 1 , wherein the purification of the carbon includes washing the carbon with a base solution to remove residual oxides.

11. The system according to claim 1 , wherein the purification of the carbon includes mechanical separation techniques such as sieving or filtration.

12. The system according to claim 1 , wherein the separator tank separates carbon from the reactive medium by using acids, alkalines, and electrolysis.

13. The system according to claim 1 , wherein the carbon comprises at least one of graphene and carbon nanotubes.

14. The system according to claim 1 , wherein the regeneration of the chemical mixture is achieved by heating to a temperature between 50°C and 500°C or by applying a vacuum to desorb absorbed CO2.

15. A method of reducing carbon dioxide to solid carbon in a closed-loop system, the method comprising: introducing gaseous carbon dioxide into a reactor vessel containing a reactive medium, wherein the gaseous carbon dioxide is sparged into the reactive medium, resulting in a chemical reaction that produces a mixture of solid carbon and oxide; separating the solid carbon from the oxide in a separator tank, allowing the oxide to flow through a liquid outlet while conveying the solid carbon to a solid outlet; regenerating the oxide into a reactive medium in a regenerator by reducing the oxide back to its active form using a reductant gas selected from the group consisting of hydrogen, methane, or other hydrocarbons; recycling the regenerated reactive medium back into the reactor vessel to maintain continuous operation; and purifying the separated solid carbon in a purifier by treating it to remove any residual oxides or contaminants, thereby producing high-purity carbon.

16. The method according to claim 15, wherein the reactive medium is selected from liquid metals or chemical mixtures.

17. The method according to claim 15, wherein the purification of the carbon includes washing the carbon with a base solution or using mechanical separation techniques.

18. The method according to claim 16, wherein the reactive medium comprises aqueous amines, ionic liquids, carbonate / bicarbonate salts, polyalkylene glycol, organic solvents, or molten salts.

19. The method according to claim 16, wherein the reactive medium is a liquid metal, including gallium, indium, tin, or aluminium.

20. The method according to claim 16, wherein the chemical mixture is regenerated by heating to a temperature between 50°C and 500°C or by applying a vacuum to desorb absorbed CO2.

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