Method for preparing high-performance carbon material from coal liquefied asphalt
By thermal extraction and mixing coal liquefaction pitch with pyrolysis tar to form an interpenetrating network structure, the problems of high ash content and wide pore size distribution of activated carbon in the existing technology are solved, and the preparation of high-performance carbon materials is achieved, especially with a significant improvement in specific surface area.
Patent Information
- Application Number
- CN202510871566.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-26
- Publication Date
- 2025-09-26
AI Technical Summary
In the existing technology, activated carbon prepared from biomass and coal has a high ash content and a wide pore size distribution, and there is a lack of suitable methods for preparing high-performance activated carbon from liquefied asphalt, resulting in high energy consumption and complex processes.
Ash-free extracted asphalt is extracted from coal liquefaction asphalt by thermal extraction and mixed with pyrolysis tar to form an interpenetrating network structure precursor, and high-performance carbon materials are prepared through carbonization and activation.
The prepared carbon material has an ultra-high specific surface area, which improves the performance of activated carbon, especially the specific surface area can reach up to 3400m2/g.
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Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of carbon material preparation, and in particular relates to a method for preparing high-performance carbon material from coal liquefaction pitch. Background Art
[0002] Currently, the raw materials for the preparation of activated carbon are mainly biomass and coal, and the prepared activated carbon has a high ash content and a wide pore size distribution.
[0003] Patent CN116282013A discloses a method for preparing highly efficient activated carbon for VOCS adsorption. The method comprises the following steps: washing rice husks with deionized water to remove surface impurities, followed by drying to constant weight to obtain dried rice husks; ultrasonically impregnating the dried rice husks in a saturated sodium fluoride solution at room temperature; filtering the impregnated rice husks, freezing the resulting filter cake, pressing it, and then freeze-drying it under vacuum to obtain pressed rice husks; heating the pressed rice husks to 550-650°C in a nitrogen atmosphere, maintaining the temperature for carbonization, then further heating the temperature to 1500-1550°C for high-temperature reaction, and then further heating the temperature to 1700-1720°C. After the high-temperature reaction, cooling and discharging the material to obtain a carbonized material; and activating the carbonized material with a potassium hydroxide solution to obtain the product. This method has an excessively high reaction temperature, resulting in high energy consumption.
[0004] Patent CN118387872A discloses a method for preparing highly hygroscopic walnut shell activated carbon. The method involves washing the walnut shells, crushing and screening them, pyrolyzing the crushed shells at 600°C, and grinding them into a powder. The ground carbon powder is then acid-washed to remove ash and then immersed in a sodium acetate solution. The dried carbon is then evenly distributed in a silica sol, resulting in an activated carbon with excellent adsorption capacity and chemical stability. While this method addresses the issues of complex production processes and high energy consumption, the acid-washing process is incomplete, resulting in a high ash content in the resulting activated carbon, which affects performance.
[0005] Liquefied pitch is a solid waste product from the direct coal liquefaction process, comprising approximately 30% by weight of the raw coal. This high volume of coal liquefaction is challenging to process. However, coal liquefaction pitch offers advantages such as low volatile matter content, high carbon content, and high carbonization yield, making it suitable for producing activated carbon. However, there is currently no suitable method for producing high-surface-weight, high-performance activated carbon from liquefied pitch.
[0006] In view of this, the present invention is proposed. Summary of the Invention
[0007] The purpose of the present invention is to provide a method for preparing high-performance carbon materials from coal liquefaction pitch. The method uses coal liquefaction pitch as raw material, adopts thermal extraction to obtain ash-free extraction pitch, pyrolysis tar is obtained by pyrolysis of the extraction residue, and the pyrolysis tar is added to the ash-free extraction pitch. After carbonization and activation, a carbon material with an interpenetrating network structure and an ultra-high specific surface area is obtained.
[0008] In order to achieve the above objectives, the present invention adopts the following technical solutions:
[0009] The present invention provides a method for preparing high-performance carbon materials from coal liquefaction pitch, comprising the following steps:
[0010] The coal liquefaction pitch and the extractant are mixed and then subjected to hot extraction to obtain ash-free extracted pitch and extraction residue;
[0011] pyrolyzing the extraction residue to obtain pyrolysis tar;
[0012] The pyrolysis tar is mixed with the ash-free extraction asphalt, and the carbon material is obtained after carbonization and activation.
[0013] Optionally, the extractant includes one or more of n-hexane, cyclohexane, toluene, xylene, tetrahydrofuran, 1-methylnaphthalene or coal liquefaction heavy oil.
[0014] Furthermore, the mass ratio of the coal liquefaction pitch to the extractant is 1:10-40.
[0015] Furthermore, the temperature of the thermal extraction is 50-300° C.; and the pressure of the step-by-step thermal dissolution is 0.1-6 MPa.
[0016] In one embodiment, the pyrolysis temperature is 450-650° C., and the pyrolysis time is 20-40 min.
[0017] Furthermore, the pyrolysis tar and ash-free extraction asphalt are mixed by dissolving the pyrolysis tar in tetrahydrofuran, adding the ash-free extraction asphalt and stirring for 1-2 hours, and then removing the tetrahydrofuran by rotary evaporation to obtain the asphalt-based interpenetrating network structure precursor.
[0018] Furthermore, the mass ratio of the pyrolysis tar to the ash-free extracted asphalt is 1:2-10; the mass ratio of the total mass of the pyrolysis tar and the ash-free extracted asphalt to the tetrahydrofuran solvent is 1:50-100.
[0019] In another embodiment, the pyrolysis is first carried out at 450-550°C for 30-35 minutes to obtain a first pyrolysis tar, and then at 550-650°C for 5-10 minutes to obtain a second pyrolysis tar.
[0020] Furthermore, the pyrolysis tar and the ash-free extracted asphalt are mixed into a first mixing and a second mixing, and then the products of the first mixing and the second mixing are mixed evenly.
[0021] The first mixing comprises dissolving the first pyrolysis tar in tetrahydrofuran, adding ash-free extraction asphalt and stirring for 1-2 hours, and then removing tetrahydrofuran by rotary evaporation to obtain a first precursor; the second mixing comprises dissolving the second pyrolysis tar in n-hexane, adding ash-free extraction asphalt and stirring for 1-2 hours, and then removing n-hexane by rotary evaporation to obtain a second precursor.
[0022] The mass ratio of the first pyrolysis tar to the ash-free extracted asphalt is 1:2-10; the mass ratio of the second pyrolysis tar to the ash-free extracted asphalt is 1:2-10. The mass ratio of the total mass of the first pyrolysis tar and the ash-free extracted asphalt to the corresponding tetrahydrofuran solvent is 1:25-50, and the mass ratio of the total mass of the second pyrolysis tar and the ash-free extracted asphalt to the corresponding n-hexane solvent is 1:25-50.
[0023] In either the first or second scheme, pyrolysis is carried out under an inert gas atmosphere.
[0024] Furthermore, the carbonization temperature is 700-1000°C.
[0025] Furthermore, the activation includes physical activation or chemical activation; the activation temperature is 700-1000°C.
[0026] The physical activation method generally uses water vapor or CO2 activation, the temperature is 700-1000°C, the heating rate is 2-10°C / min, and the activation time is 1-2h.
[0027] The chemical activation method generally includes adding an activator, the activator is phosphoric acid or potassium hydroxide, the mass ratio of phosphoric acid to raw materials is 0.2-0.8:1, the mass ratio of potassium hydroxide to raw materials is 2-5:1, the temperature is 700-1000°C, the heating rate is 2-10°C / min, and it is carried out under nitrogen or argon atmosphere. The activation time is 1-2h.
[0028] Optionally, the carbon material includes microporous carbon for supercapacitors, spherical activated carbon, activated carbon fibers, or carbon materials for hydrogen fuel cell catalyst supports.
[0029] When the carbon material is spherical activated carbon, the mixed pyrolysis tar and ash-free extraction asphalt are first subjected to thermal polycondensation to form balls, and then carbonized and / or activated to obtain the spherical activated carbon.
[0030] Specifically, the mixed pyrolysis tar and ash-free extracted asphalt are heated and stirred at 180-280°C to melt, a 1-10% by mass surfactant aqueous solution is placed in an autoclave, and the melted pyrolysis tar and ash-free extracted asphalt are slowly injected into the autoclave and heated and stirred to obtain microspheres at a temperature of 200-300°C, a reaction time of 2-10 hours, and a stirring rate of 300-1000 r / min. The microspheres are vacuum-dried at 50-200°C for 2-10 hours, then heated in an air atmosphere at 180-250°C for curing and crosslinking for 2-6 hours, then carbonized at 700-1000°C and activated at 700-1000°C to obtain the spherical activated carbon.
[0031] Optionally, the surfactant is one of polyvinyl alcohol, polyethylene glycol, stearic acid, and Tween.
[0032] Furthermore, the mass ratio of the molten mixture of the pyrolysis tar and the ash-free extracted asphalt to the surfactant aqueous solution is 1:2-10.
[0033] When the carbon material is activated carbon fiber, the mixed pyrolysis tar and ash-free extraction pitch are first melt-spun and then carbonized and / or activated to obtain the activated carbon fiber.
[0034] Specifically, the mixed pyrolysis tar and ash-free extracted asphalt are melt-spun in a melt spinning machine under a nitrogen atmosphere at a temperature of 230-250°C, a pressure of 0.5 MPa, and a rotation speed of 200-500 r / min to produce asphalt fiber precursors. The resulting asphalt fiber precursors are then heated in an air atmosphere at 180-250°C for 2-6 hours to produce stabilized fibers, which are then carbonized at 700-1000°C and activated at 700-1000°C to produce the activated carbon fibers.
[0035] When the carbon material is a carbon material for a hydrogen fuel cell catalyst carrier, magnesium oxide is added to the mixed pyrolysis tar and ash-free extracted asphalt, and then the mixture is carbonized, pickled, washed, activated, and graphitized to obtain the carbon material for a hydrogen fuel cell catalyst carrier.
[0036] Specifically, magnesium oxide is added to a mixture of pyrolysis tar and ash-free extracted asphalt, and the mixture is carbonized at 700-1000°C under a nitrogen atmosphere. The carbonized sample is then acid-washed to remove the magnesium oxide, with a sample-to-acid mass ratio of 1:5-20. The sample is then washed with deionized water until neutral, and activated at 700-1000°C. The activated sample is graphitized at 1600-2000°C under a nitrogen atmosphere for 2 hours to obtain the carbon material for a hydrogen fuel cell catalyst support.
[0037] Furthermore, the mass ratio of the mixture of pyrolysis tar and ash-free extracted asphalt to magnesium oxide is 1:2-5.
[0038] Compared with the existing technology, the present invention uses thermal extraction to extract ash-free extracted asphalt from coal liquefaction pitch, and mixes the ash-free extracted asphalt with the tar obtained by pyrolysis of the extract residue to form an interpenetrating network structure precursor based on asphalt. Since the pyrolysis tar and the extracted asphalt have different thermal stabilities, the easily decomposable components in the pyrolysis tar volatilize during the carbonization process, forming an interpenetrating network pore structure in the carbon matrix, thereby improving the performance of the carbon material. In particular, the specific surface area of the activated carbon prepared by the method of the present invention can reach up to 3400m 2 / g or above. DETAILED DESCRIPTION
[0039] To make the objectives, technical solutions, and advantages of the embodiments of the present invention more clear, the technical solutions in the embodiments of the present invention will be clearly and completely described below in conjunction with the accompanying drawings of the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts shall fall within the scope of protection of the present invention.
[0040] It should be noted that the raw materials used in this invention are all commercially available products. Any ratios not specified herein may be any ratio. The units of all ratios not specified herein are all mass ratios. Any technical details not elaborated herein are prior art. The coal liquefaction pitch described in the Examples and Comparative Examples was produced by the Shenhua Ordos direct coal liquefaction project.
[0041] Example 1
[0042] A method for preparing high-performance carbon materials from coal liquefaction pitch:
[0043] Coal liquefaction pitch was placed in a flow reactor, and tetrahydrofuran (THF) was pumped in at a rate of 1 mL / min. The mass ratio of coal liquefaction pitch to THF was maintained at 1:20. The reaction temperature was adjusted to 200°C, the pressure to 2 MPa, and the reaction time was 2 hours. A mixture of ash-free extracted pitch and THF was collected at the outlet. The THF was removed from the mixture by rotary evaporation. The extract residue from the reactor was removed and pyrolyzed in a fixed bed at 550°C for 30 minutes to produce pyrolysis tar. The ash-free extracted pitch and pyrolysis tar were added to THF at a mass ratio of 5:1 (the mass ratio of the total mass of ash-free extracted pitch and pyrolysis tar to THF was 1:50), stirred for 1 hour, and then the THF was removed by rotary evaporation. The extracted asphalt mixed with pyrolysis tar was placed in a tubular furnace. First, the temperature was raised to 180°C at a heating rate of 5°C / min in an air atmosphere and maintained for 2 hours. Then, the temperature was raised to 700°C at a heating rate of 5°C / min in a nitrogen or argon atmosphere and carbonized for 2 hours. After carbonization, it was mixed with potassium hydroxide at a mass ratio of 1:4 and activated by heating to 900°C at 5°C / min in a nitrogen atmosphere for 2 hours to obtain activated carbon with an interpenetrating network pore structure. The BET specific surface area test showed that the activated carbon had a specific surface area of 2887m 2 / g.
[0044] Example 2
[0045] A method for preparing high-performance carbon materials from coal liquefaction pitch:
[0046] Coal liquefaction pitch was placed in a flow reactor, and cyclohexane was pumped in at a rate of 1 mL / min. The mass ratio of coal liquefaction pitch to cyclohexane was controlled at 1:25. The reaction temperature was adjusted to 250°C, the reaction pressure was adjusted to 2 MPa, and the reaction time was 2 hours. A mixture of ash-free extracted pitch and cyclohexane was collected at the outlet. The cyclohexane was removed from the mixture by rotary evaporation. The extract residue from the reactor was removed and pyrolyzed in a fixed bed at 500°C for 30 minutes to produce pyrolysis tar. The ash-free extracted pitch and pyrolysis tar were added to tetrahydrofuran at a mass ratio of 5:1 (the mass ratio of the total mass of ash-free extracted pitch and pyrolysis tar to tetrahydrofuran was 1:70), stirred for 1 hour, and then the tetrahydrofuran was removed by rotary evaporation. The extracted asphalt mixed with pyrolysis tar was placed in a tubular furnace. First, the temperature was raised to 250°C at a heating rate of 5°C / min in an air atmosphere and maintained for 2 hours. Then, the temperature was raised to 700°C at a heating rate of 3°C / min in a nitrogen or argon atmosphere and carbonized for 2 hours. After carbonization, it was mixed with potassium hydroxide at a mass ratio of 1:4 and activated by heating to 900°C at 3°C / min in a nitrogen atmosphere for 2 hours to obtain activated carbon with an interpenetrating network pore structure. The BET specific surface area test showed that the activated carbon had a specific surface area of 3346 m 2 / g.
[0047] Example 3
[0048] A method for preparing high-performance carbon materials from coal liquefaction pitch
[0049] Coal liquefaction pitch was placed in a flow reactor and pumped into coal liquefaction heavy oil at a rate of 5 mL / min. The mass ratio of coal liquefaction pitch to coal liquefaction heavy oil was controlled at 1:15. The reaction temperature was adjusted to 250°C, the pressure to 3 MPa, and the reaction time was 1 hour. A mixture of ash-free extracted pitch and coal liquefaction heavy oil was collected at the outlet. The coal liquefaction heavy oil was removed from the mixture by centrifugation. The extract residue from the reactor was removed and pyrolyzed in a fixed bed at 600°C for 20 minutes to produce pyrolysis tar. The ash-free extracted pitch and pyrolysis tar were added to tetrahydrofuran at a mass ratio of 5:1 (the mass ratio of the total mass of ash-free extracted pitch and pyrolysis tar to tetrahydrofuran was 1:50) and stirred for 1 hour. The tetrahydrofuran was then removed by rotary evaporation. The extracted asphalt mixed with pyrolysis tar was placed in a tubular furnace. First, the temperature was raised to 250°C at a heating rate of 10°C / min in an air atmosphere and maintained for 2 hours. Then, the temperature was raised to 700°C at a heating rate of 10°C / min in a nitrogen or argon atmosphere and carbonized for 2 hours. After carbonization, it was mixed with potassium hydroxide at a mass ratio of 1:4 and activated by heating to 900°C at 10°C / min in a nitrogen atmosphere for 2 hours to obtain activated carbon with an interpenetrating network pore structure. The BET specific surface area test showed that the activated carbon had a specific surface area of 2632m 2 / g.
[0050] Example 4
[0051] A method for preparing high-performance carbon materials from coal liquefaction pitch:
[0052] Coal liquefaction pitch was placed in a flow reactor, and cyclohexane was pumped in at a rate of 1 mL / min. The mass ratio of coal liquefaction pitch to cyclohexane was maintained at 1:25. The reaction temperature was adjusted to 250°C, the pressure to 2 MPa, and the reaction time was 2 hours. A mixture of ash-free extracted pitch and cyclohexane was collected at the outlet. The cyclohexane was removed from the mixture by rotary evaporation. The extract residue was removed from the reactor and pyrolyzed in a fixed bed at 450°C for 30 minutes to produce a first pyrolysis tar. Subsequently, the reaction was continued at 650°C for 10 minutes to produce a second pyrolysis tar. The ash-free extracted pitch and the first pyrolysis tar were added to tetrahydrofuran at a mass ratio of 5:1 and stirred for 1 hour (the mass ratio of the total mass of the ash-free extracted pitch and the first pyrolysis tar to the tetrahydrofuran was 1:35). The ash-free extracted pitch and the second pyrolysis tar were added to tetrahydrofuran at a mass ratio of 5:1 and stirred for 1 hour (the mass ratio of the total mass of the ash-free extracted pitch and the second pyrolysis tar to n-hexane was 1:35). The tetrahydrofuran and n-hexane were then removed by rotary evaporation to obtain the first and second precursors. The mixture of the first and second precursors was placed in a tube furnace and first heated to 250°C at a heating rate of 5°C / min in an air atmosphere and held for 2 hours. Then, the mixture was heated to 700°C at a heating rate of 3°C / min in a nitrogen or argon atmosphere and carbonized for 2 hours. After carbonization, it was mixed with potassium hydroxide in a mass ratio of 1:4, and heated to 900℃ at 3℃ / min for 2h under nitrogen atmosphere to obtain activated carbon with an interpenetrating network pore structure. The BET specific surface area test showed that the activated carbon had a specific surface area of 3430m 2 / g.
[0053] Example 5
[0054] The mixed ash-free extraction asphalt and pyrolysis tar in Example 1 were heated to 200°C and stirred to melt. A 5% polyethylene glycol aqueous solution was placed in a high-pressure reactor. The molten pyrolysis tar and ash-free extraction asphalt were slowly injected into the high-pressure reactor and heated and stirred to obtain microspheres. The mass ratio of the molten mixture of pyrolysis tar and ash-free extraction asphalt to the polyethylene glycol aqueous solution was 1:2, the temperature was 300°C, the reaction time was 2h, and the stirring rate was 500r / min. The microspheres were vacuum dried at 150°C for 5h, then heated in an air atmosphere at 250°C for curing and crosslinking for 2h, and then heated to 700°C in a nitrogen atmosphere at a heating rate of 5°C / min for carbonization for 2h. After carbonization, they were mixed with potassium hydroxide in a mass ratio of 1:4 and activated by heating to 900°C in a nitrogen atmosphere at 5°C / min for 2h to obtain spherical activated carbon with an interpenetrating network pore structure. The BET specific surface area test showed that the specific surface area of the spherical activated carbon was 2564m 2 / g.
[0055] Example 6
[0056] Add magnesium oxide to the ash-free extraction asphalt and pyrolysis tar mixed in Example 1 and stir and mix (the mass ratio of the total mass of ash-free extraction asphalt and pyrolysis tar to magnesium oxide is 1:2). Heat to 700°C at a heating rate of 5°C / min under a nitrogen atmosphere and carbonize for 2 hours. The carbonized sample is pickled with 6 mol / L hydrochloric acid, and the sample and hydrochloric acid are pickled at a mass ratio of 1:10 to remove magnesium oxide, and then washed with deionized water until neutral; the pickled sample is mixed with potassium hydroxide at a mass ratio of 1:4, and heated to 900°C at 5°C / min under a nitrogen atmosphere for activation for 2 hours. The activated sample is graphitized at 2000°C under a nitrogen atmosphere for 2 hours to obtain a carbon material that can be used as a catalyst carrier for hydrogen fuel cells. According to the BET specific surface area test, the specific surface area of the carbon material is 1526m 2 / g.
[0057] Example 7
[0058] The ash-free extracted asphalt and pyrolysis tar mixed in Example 1 were melt-spun in a melt spinning machine to obtain asphalt fiber precursors in a nitrogen atmosphere, a temperature of 230°C, a pressure of 0.5 MPa, and a rotation speed of 300 r / min. The obtained asphalt fiber precursors were heated at 250°C in an air atmosphere for curing and cross-linking for 2 hours. Then, the temperature was raised to 700°C at a heating rate of 5°C / min under a nitrogen atmosphere and carbonized for 2 hours. After carbonization, it was mixed with potassium hydroxide in a mass ratio of 1:4, and the temperature was raised to 900°C at 5°C / min under a nitrogen atmosphere for activation for 2 hours to obtain activated carbon fibers with an interpenetrating network pore structure. According to the BET specific surface area test, the specific surface area of the obtained activated carbon fiber was 2725m 2 / g.
[0059] Comparative Example 1
[0060] The difference from Example 1 is that the raw material is replaced with medium and low temperature coal tar pitch produced by Yan'an Energy Chemical (Group) Co., Ltd., and the specific surface area of the activated carbon obtained is 2027m 2 / g.
[0061] Comparative Example 2
[0062] The difference from Example 1 is that the ash-free extracted asphalt is not mixed with pyrolysis tar, and the activated carbon is directly prepared. The specific surface area of the obtained activated carbon is 1027m 2 / g.
[0063] Comparative Example 3
[0064] Different from Example 2, the ash-free extracted asphalt was not mixed with pyrolysis tar, and activated carbon was directly prepared. The specific surface area of the activated carbon obtained was 2337m 2 / g.
[0065] Comparative Example 4
[0066] Different from Example 3, the ash-free extracted asphalt was not mixed with pyrolysis tar, and activated carbon was directly prepared. The specific surface area of the activated carbon obtained was 986m 2 / g.
[0067] Comparative Example 5
[0068] The difference from Example 5 is that the ash-free extracted asphalt is not mixed with pyrolysis tar, and spherical activated carbon is directly prepared. The specific surface area of the obtained spherical activated carbon is 1097m 2 / g.
[0069] Comparative Example 6
[0070] The difference from Example 6 is that the ash-free extracted asphalt is not mixed with pyrolysis tar, and is directly used to prepare the carbon material for hydrogen fuel cell catalyst support. The specific surface area of the obtained carbon material is 817m 2 / g.
[0071] Comparative Example 7
[0072] Different from Example 6, the ash-free extracted asphalt was not mixed with pyrolysis tar, and the activated carbon fiber was directly prepared. The specific surface area of the activated carbon fiber obtained was 1257m 2 / g.
[0073] Table 1 is the pore structure comparison data of different carbon material products in the examples and comparative examples
[0074] Table 1 Pore structure parameters of different carbon materials
[0075]
[0076]
[0077] It can be seen that the carbon materials obtained by carbonizing and activating the precursors mixed with ashless extraction pitch and pyrolysis tar in Examples 1-7 have significantly higher specific surface area and pore volume than the different raw materials in Comparative Example 1 and the carbon materials obtained without pyrolysis tar in Comparative Examples 2-7. By comparing Example 2 and Example 4, it can be seen that after the pyrolysis products of the extract residue are mixed with ashless extraction pitch at different temperatures, the resulting precursors have a subdivided pore structure. Compared with the precursors subjected to single pyrolysis, their pore structure is restructured and adjusted to be more microporous. Therefore, the activated carbon obtained in Example 4 has a greater proportion of micropores, and the total specific surface area and pore volume are both improved.
[0078] Finally, it should be noted that the above embodiments are intended only to illustrate the technical solutions of the present invention and are not intended to limit them. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art will appreciate that the technical solutions described in the aforementioned embodiments may be modified, or some or all of the technical features therein may be replaced with equivalents. Such modifications or replacements do not deviate from the essence of the corresponding technical solutions within the scope of the technical solutions of the various embodiments of the present invention. Furthermore, those skilled in the art will appreciate that although some embodiments herein include certain features included in other embodiments but not others, the combination of features from different embodiments is intended to be within the scope of the present invention and to form different embodiments. For example, in the claims above, any of the claimed embodiments may be used in any combination. The information disclosed in this background section is intended solely to enhance understanding of the overall background technology of the present invention and should not be construed as an admission or any form of implication that such information constitutes prior art already known to those skilled in the art.
Claims
1. A method for preparing high-performance carbon materials from coal liquefaction pitch, characterized in that: The steps include: The coal liquefaction pitch and the extractant are mixed and then subjected to hot extraction to obtain ash-free extracted pitch and extraction residue; pyrolyzing the extraction residue to obtain pyrolysis tar; The pyrolysis tar is mixed with the ash-free extraction asphalt, and the carbon material is obtained after carbonization and activation.
2. The method according to claim 1, characterized in that The extractant includes one or more of n-hexane, cyclohexane, toluene, xylene, tetrahydrofuran, 1-methylnaphthalene or coal liquefaction heavy oil; And / or, the temperature of the thermal extraction is 50-300°C; And / or, the pressure of the step-by-step thermal dissolution is 0.1-6 MPa.
3. The method according to claim 1, characterized in that The pyrolysis temperature is 450-650°C; And / or, the pyrolysis time is 20-40 min.
4. The method according to claim 3, characterized in that The mixing of pyrolysis tar and ash-free extraction asphalt is carried out by dissolving pyrolysis tar in tetrahydrofuran, adding ash-free extraction asphalt and stirring for 1-2 hours, and then removing tetrahydrofuran by rotary evaporation to obtain an asphalt-based interpenetrating network structure precursor; And / or, the mass ratio of the pyrolysis tar to the ash-free extracted asphalt is 1:2-10.
5. The method according to claim 1, wherein The pyrolysis is carried out by first reacting at 450-550° C. for 30-35 minutes to obtain a first pyrolysis tar, and then reacting at 550-650° C. for 5-10 minutes to obtain a second pyrolysis tar.
6. The method according to claim 5, characterized in that The pyrolysis tar and the ash-free extracted asphalt are mixed into a first mixing and a second mixing, and then the products of the first mixing and the second mixing are mixed evenly; The first mixing comprises dissolving the first pyrolysis tar in tetrahydrofuran, adding ash-free extraction asphalt and stirring for 1-2 hours, and then removing the tetrahydrofuran by rotary evaporation to obtain a first precursor; The second mixing step comprises dissolving the second pyrolysis tar in n-hexane, adding ash-free extraction asphalt, stirring for 1-2 hours, and then removing the n-hexane by rotary evaporation to obtain a second precursor; and / or, the mass ratio of the first pyrolysis tar to the ashless extracted asphalt is 1:2-10; And / or, the mass ratio of the second pyrolysis tar to the ash-free extracted asphalt is 1:2-10.
7. The method according to any one of claims 1 to 6, characterized in that The carbon material includes activated carbon for supercapacitors, spherical activated carbon, activated carbon fibers or carbon materials for hydrogen fuel cell catalyst supports.
8. The method according to claim 7, characterized in that When the carbon material is spherical activated carbon, the mixed pyrolysis tar and ash-free extraction asphalt are first subjected to thermal polycondensation to form balls, and then carbonized and / or activated to obtain the spherical activated carbon.
9. The method according to claim 7, characterized in that When the carbon material is activated carbon fiber, the mixed pyrolysis tar and ash-free extraction pitch are first melt-spun and then carbonized and / or activated to obtain the activated carbon fiber.
10. The method according to claim 7, characterized in that When the carbon material is a carbon material for a hydrogen fuel cell catalyst carrier, magnesium oxide is added to the mixed pyrolysis tar and ash-free extraction asphalt, and then carbonized, pickled, washed, activated, and graphitized to obtain the carbon material for a hydrogen fuel cell catalyst carrier.