Porous carbon material taking black mountain coal as raw material and preparation method of porous carbon material

Abstract

The invention belongs to the field of coal chemical industry, and relates to a porous carbon material taking black mountain coal as a raw material and a preparation method thereof. The method comprises the following steps: (1) crushing black mountain coal, grinding and screening; (2) carrying out acid pickling and pre-deliming on the screened black mountain coal raw material, washing with water to remove residual acid liquor in the raw material, and drying; (3) carrying out pre-oxidation treatment on the material obtained in the pre-deliming process; then carrying out carbonization treatment on the pre-oxidized product; (4) grinding and mixing the obtained carbonized material and an alkaline activator, and activating; and (5) post-treatment: carrying out acid pickling post-treatment on the obtained activated material, washing with water to remove residual acid liquor in the material, and drying to obtain a porous carbon product. According to the invention, the porous carbon material with low ash content and high specific surface area is prepared, the preparation process is simpler and more convenient, the cost is lower, and both process simplification and product quality guarantee are realized.

Description

Technical Field

[0001] The invention belongs to the field of coal chemical industry and relates to a porous carbon material using Heishan coal as raw material and a preparation method thereof. Background Art

[0002] At present, with the rapid development of new energy storage and environmental protection technologies, the industry is looking for ultra-low ash (ash content <1%), ultra-high specific surface area (>2000m 2 The demand for porous carbon materials (>1000 wt%) is increasingly urgent. Such materials must possess a hierarchical microporous-mesoporous structure to optimize mass transfer efficiency while avoiding the negative impact of residual ash on electrode reactivity or adsorption selectivity. However, existing commercial porous carbons generally struggle with synergistic ash control and pore size regulation.

[0003] Patent document CN105060290A discloses a method for preparing coal-based low-ash, high-specific surface area activated carbon. First, the coal is crushed to less than 150 μm to obtain coal powder, a strong base compound is added and mixed evenly, and then, under the protection of an inert gas, it is heated and activated to obtain an activated product; the obtained activated product is then acid-washed and washed with water until the filtrate is neutral, and then a strong base compound is added and mixed evenly. Under the protection of an inert gas, it is heated to a constant temperature, and then the inert gas is switched to water vapor for activation to obtain a final activated product; finally, the obtained final activated product is acid-washed and washed with water until the filtrate is neutral, and then dried to obtain a low-ash, high-specific surface area activated carbon product.

[0004] The current preparation methods of high specific surface area activated carbon still have some limitations: first, the properties of the selected raw materials have certain limitations, and the ash in the raw materials will affect the development of the pore structure during the activation process. In addition, for raw coal with low metamorphic degree, post-acid washing of the activated product is also prone to cause pore collapse, resulting in a decrease in specific surface area; second, the preparation process is complicated. The raw materials are prepared through chemical activation-acid washing-physical and chemical coupled activation-acid washing process to prepare low-ash and high specific surface area activated carbon. The preparation process is relatively cumbersome, and the etching effect of the two strong alkalis will seriously affect the product yield, resulting in poor economic efficiency.

[0005] Due to its unique chemical composition and physical properties, Heishan coal can be one of the preferred raw materials for the preparation of ultra-low ash and ultra-high specific surface area porous carbon materials. As a raw material for the preparation of ultra-low ash and ultra-high specific surface area porous carbon materials, Heishan coal has the advantages of low ash and sulfur content, which makes it easy to carry out deep deashing treatment; and its high calorific value also provides an efficient carbon source for carbonization and activation. However, the volatile matter of this type of coal is low, which will lead to insufficient autogenous pores during the carbonization process. It is difficult to achieve ultra-high specific surface area of ​​porous carbon materials by activating Heishan coal using traditional physical activation methods; and although a single chemical activation method can increase the specific surface area of ​​porous carbon materials, it is difficult to simultaneously solve the problems of missing mesopores and secondary enrichment of ash in porous carbon materials.

[0006] Therefore, the development of a synergistic process of directional pore control and deep ash removal based on Heishan coal as raw material has become a key path to break through the technical barriers of high-performance porous carbon preparation. Summary of the Invention

[0007] The purpose of the present invention is to solve the problems of complex preparation process and low product yield of existing low-ash and high-specific-surface-area activated carbon. The present invention provides an ultra-low-ash and ultra-high-specific-surface-area porous carbon material and its preparation method. With low-ash, low-sulfur and high-calorific-value Heishan coal as raw material, the ash content of the obtained product can be controlled below 1% through a one-step preparation process of raw material pre-deashing - chemical activation - post-deashing. At the same time, the specific surface area is higher than 2000m 2 / g, not only can porous carbon materials with low ash content and high specific surface area be produced, but also the preparation process can be simplified and the cost can be lowered, achieving a balance between simplifying the process and ensuring product quality. The ultra-low ash and ultra-high specific surface area porous carbon materials produced can be used in the fields of energy storage and high-precision environmental protection.

[0008] In order to achieve the above object, the present invention provides the following technical solutions:

[0009] In a first aspect, a method for preparing a porous carbon material using Heishan coal as a raw material is provided, comprising the following steps:

[0010] (1) Raw material screening: crush the Black Mountain coal, grind it into powder and screen it;

[0011] (2) Pre-deashing: The screened Heishan coal raw material is acid-washed and pre-deashed, then washed with water to remove residual acid in the raw material and dried;

[0012] (3) Pre-oxidation and carbonization: The material obtained from the pre-deashing process is pre-oxidized; the product after pre-oxidation is then carbonized to obtain a carbonized material;

[0013] (4) Activation: Grinding and mixing the obtained carbonized material with an alkaline activator, and performing an activation treatment to obtain an activated material;

[0014] (5) Post-treatment: The activated material is subjected to acid washing, then washed with water to remove the residual acid in the material and dried to obtain a porous carbon product.

[0015] According to the preparation method provided by the present invention, in some embodiments, the particle size range of the Heishan coal after grinding and screening is 200 mesh-500 mesh, for example, 205 mesh, 210 mesh, 220 mesh, 240 mesh, 250 mesh, 260 mesh, 280 mesh, 300 mesh, 320 mesh, 350 mesh, 400 mesh, 420 mesh, 450 mesh, and 480 mesh.

[0016] Uniform Heishan coal particles are conducive to more complete ash removal from the raw materials, and at the same time can ensure more uniform heating in the subsequent pre-oxidation stage, carbonization stage and activation stage, so that carbon materials with higher specific surface area can be obtained.

[0017] In the present invention, the equipment used for grinding and screening can be conventionally selected in the art and will not be described in detail here.

[0018] In the Black Mountain coal described in the present invention, the ash content can be 1-4% (for example, 1.5%, 2%, 2.5%, 3%, 3.5%), and the sulfur content can be 0-0.5% (for example, 0.01%, 0.02%, 0.05%, 0.1%, 0.15%, 0.2%, 0.3%, 0.4%, 0.45%); its calorific value range can be 30-40MJ / kg (for example, 32MJ / kg, 34MJ / kg, 35MJ / kg, 36MJ / kg, 38MJ / kg).

[0019] According to the preparation method provided by the present invention, in some embodiments, the acid solution used for the pickling pre-deliming in step (2) is selected from one or more of hydrochloric acid aqueous solution, sulfuric acid aqueous solution, nitric acid aqueous solution, hydrofluoric acid aqueous solution and oxalic acid aqueous solution; preferably, sulfuric acid aqueous solution.

[0020] In some embodiments, the concentration of the acid solution in step (2) is 2 wt%-15 wt%, for example, 3 wt%, 4 wt%, 5 wt%, 6 wt%, 8 wt%, 10 wt%, 12 wt%, 14 wt%.

[0021] In some embodiments, the process conditions for pickling and pre-deliming in step (2) include: a pickling temperature of 50-90°C (for example, 55°C, 60°C, 70°C, 80°C, 85°C), and a pickling time of 0.25h-2h (for example, 0.5h, 1h, 1.25h, 1.5h, 1.8h).

[0022] Acid washing pre-deashing can remove various metal salts and silicon oxides contained in the raw materials, which is beneficial to inhibit the sintering of ash particles and optimize the pore structure of carbon materials.

[0023] The drying process conditions in step (2) can be conventionally selected in the art and will not be described in detail here.

[0024] According to the preparation method provided by the present invention, in some embodiments, the process conditions of the pre-oxidation treatment in step (3) include: a treatment temperature of 20-350°C (for example, 20-250°C, 20-255°C, 20-280°C, 20-300°C, 20-310°C, 20-320°C, 20-330°C, 20-340°C), a heating rate of 2-10°C / min (for example, 2.5°C / min, 3°C / min, 4°C / min, 5°C / min, 6°C / min, 8°C / min, 9°C / min), and a treatment time of 30-165min (for example, 35min, 45min, 60min, 90min, 110min, 120min, 150min, 160min); and the atmosphere of the pre-oxidation treatment is air.

[0025] Regarding the pre-oxidation heating process and treatment temperature, it can be understood that the pre-oxidation process is carried out at a heating rate of 2-10°C / min from 20°C to a specific temperature (for example, 300°C, 310°C, 320°C, 330°C, 340°C, 350°C).

[0026] The volatile matter of Heishan coal after pre-deashing treatment is low. Pre-oxidation treatment can promote the formation of oxygen-containing functional groups inside it, increase the porosity generated by subsequent pyrolysis, and also slow down the pyrolysis weight loss rate, which can inhibit the coking and pore collapse problems caused by the concentrated release of volatiles.

[0027] According to the preparation method provided by the present invention, in some embodiments, the process conditions of the carbonization treatment in step (3) include: a treatment temperature of 250-650°C (for example, 255°C, 280°C, 300°C, 310°C, 320°C, 340°C, 350°C, 360°C, 380°C, 400°C, 420°C, 450°C, 480°C, 500°C, 520°C, 550°C, 580°C, 600°C, 620°C, 640°C), a heating rate of 2-10°C / min n (for example, 2.5 ° C / min, 3 ° C / min, 4 ° C / min, 5 ° C / min, 6 ° C / min, 8 ° C / min, 9 ° C / min), the final temperature holding time of the treatment is 0-1.5h (for example, 1min, 5min, 10min, 20min, 25min, 30min, 35min, 40min, 45min, 50min, 55min, 60min, 70min, 80min), and the atmosphere of the carbonization treatment is nitrogen.

[0028] In the present invention, the carbonization process can be performed by gradually heating the material from the pre-oxidation temperature to 600-650°C at a specific heating rate and maintaining the temperature for a specific time. The volatile matter in the carbonized material escapes, reducing the impurity content while forming a primary pore structure.

[0029] According to the preparation method provided by the present invention, in some embodiments, the alkaline activator is selected from one or more of sodium hydroxide, potassium hydroxide, potassium carbonate, potassium bicarbonate, sodium carbonate and sodium bicarbonate.

[0030] In some embodiments, the mass ratio of the alkaline activator to the carbonized material is in the range of 1:1-5:1, for example, 1.5:1, 2:1, 2.5:1, 3:1, 3.5:1, 4:1, 4.5:1; preferably 4:1-5:1.

[0031] The alkaline activator undergoes a redox reaction with the carbon matrix at high temperature, etching the carbon skeleton to form a rich porous structure. In the present invention, the alkaline activator is ground and mixed with the resulting carbonized material in solid form. Compared with traditional physical activators (such as H2O, CO2, etc.), the alkaline activator participates in the activation reaction in solid form, which is more efficient in forming a porous structure and can significantly increase the specific surface area of ​​the carbon material.

[0032] According to the preparation method provided by the present invention, in some embodiments, the process conditions of the activation treatment in step (4) include: a treatment temperature of 650-850°C (for example, 660°C, 680°C, 700°C, 750°C, 780°C, 800°C, 820°C, 840°C), a treatment time of 0.5-2h (for example, 0.75h, 1h, 1.25h, 1.5h, 1.8h), and the atmosphere of the activation treatment is nitrogen.

[0033] The carbon material activated by solid alkaline activator has a rich pore structure, which is conducive to further increasing the specific surface area.

[0034] According to the preparation method provided by the present invention, in some embodiments, the acid solution used for the pickling post-treatment in step (5) is selected from one or more of hydrochloric acid aqueous solution, sulfuric acid aqueous solution, nitric acid aqueous solution, hydrofluoric acid aqueous solution and oxalic acid aqueous solution.

[0035] In some embodiments, the concentration of the acid solution in step (5) is 2 wt%-15 wt%, for example, 3 wt%, 5 wt%, 6 wt%, 8 wt%, 10 wt%, 12 wt%, 14 wt%.

[0036] In some embodiments, the process conditions of the pickling post-treatment in step (5) include: a treatment temperature of 50-90°C (for example, 55°C, 60°C, 70°C, 80°C, 85°C), and a treatment time of 0.25h-2h (for example, 0.5h, 1h, 1.25h, 1.5h, 1.8h).

[0037] The pickling post-treatment can neutralize the alkalinity in the activator on the one hand, and promote the further removal of ash in the activated material on the other hand.

[0038] According to the preparation method of the present invention, in some embodiments, the water washing temperature in step (5) is 20-80°C (for example, 25°C, 30°C, 40°C, 50°C, 60°C, 70°C, 75°C), the sample is dried at a temperature of 70-100°C (for example, 75°C, 80°C, 85°C, 90°C, 95°C) after washing, and the drying time is 2-12h (for example, 2.5h, 3h, 4h, 5h, 6h, 8h, 10h).

[0039] In a second aspect, a porous carbon material prepared by the preparation method described above is provided.

[0040] In the present invention, the ash content of the porous carbon material is less than or equal to 1wt% (for example, 0.8wt%, 0.6wt%, 0.5wt%, 0.4wt%, 0.2wt%, 0.1wt%, 0.05wt%), and the specific surface area is greater than or equal to 2000m 2 / g (e.g., 2050m 2 / g、2100m 2 / g, 2150m 2 / g、2180m 2 / g、2200m 2 / g、2250m 2 / g、2300m 2 / g、2400m 2 / g).

[0041] Compared with the prior art, the beneficial effects of the technical solution of the present invention are at least:

[0042] (1) The present invention combines the process of pre-deashing of raw materials with the process of post-deashing of activated materials. Pre-deashing can reduce the damage of ash to the pore structure in the subsequent high-temperature treatment process, and post-deashing further optimizes the purity of the finished product and improves the chemical stability. In addition, compared with the activated carbon prepared by the traditional process, the porous carbon material prepared by the process of the present invention has a lower ash content.

[0043] (2) The present invention adopts a pre-oxidation-carbonization-chemical activation coupling process. Oxygen-containing groups can be introduced in the pre-oxidation stage to promote the formation of cross-linked structures in the carbonization stage and inhibit the generation of disordered structures. This can significantly improve the pore uniformity of the carbon material and form a higher specific surface area. The carbonized material is ground and mixed with an alkaline activator in solid form, and the distribution of micropores and mesopores is more uniform, further increasing the specific surface area of ​​the product.

[0044] Compared with the traditional physical activation process, the chemical activation treatment after carbonization in the pre-oxidation-carbonization-chemical activation coupling process of the present invention has higher activation efficiency, more pore content, and the specific surface area can be increased by 30%-50%;

[0045] Compared with the traditional chemical activation process (adding a solution of an activating agent to the raw material for activation treatment), in the chemical activation step of the pre-oxidation-carbonization-chemical activation coupling process of the present invention, the alkaline activating agent in solid form can deeply etch the pore structure in the carbonized material, making the distribution of micropores and mesopores more uniform, further increasing the specific surface area of ​​the product.

[0046] The present invention utilizes the characteristics of Montenegro coal and uses low-ash, low-sulfur, and high-calorific value Montenegro coal as raw material. By cleverly utilizing a simple deashing method in the preparation method, an ultra-low-ash product can be obtained; in addition, a pre-oxidation-carbonization-chemical activation coupling process is adopted to ensure the stability and uniformity of the pore structure during the deashing process and avoid the cumbersomeness of the preparation process. The prepared porous carbon material has the advantages of uniform pore size distribution, low ash content, and ultra-high specific surface area. The preparation process of the low-ash and high-specific surface area porous carbon material can be simple and low-cost, and the preparation efficiency and yield of the obtained carbon material are greatly improved, which has high practicality.

[0047] The product prepared by the present invention has better performance, the ash content of the product can be controlled below 1wt%, and the specific surface area is higher than 2000m 2 / g, which can be applied to the fields of energy storage and high-precision environmental protection. DETAILED DESCRIPTION

[0048] In order to understand the technical features and content of the present invention in detail, the preferred embodiments of the present invention will be described in more detail below. Although the preferred embodiments of the present invention are described in the embodiments, it should be understood that the present invention can be implemented in various forms and should not be limited by the embodiments set forth herein.

[0049] If no specific conditions are specified in the examples, the reaction was carried out according to conventional conditions or the conditions recommended by the manufacturer. The raw materials used in the examples are understood to be commercially available unless otherwise specified.

[0050] <Source of raw materials>

[0051] In each embodiment and comparative example, the raw material Heishan coal was sourced from Xinjiang Tuokexun Energy Co., Ltd. The Heishan coal had an ash content of 2.44%, a sulfur content of 0.44%, and a calorific value of 32.44 MJ / kg.

[0052] Example 1:

[0053] A method for preparing ultra-low ash and high specific surface area porous carbon material using Heishan coal as raw material comprises the following steps:

[0054] (1) crushing the Heishan coal raw material and then grinding and screening it to a particle size of 325 mesh;

[0055] (2) Pre-deashing: The ground and screened Heishan coal powder was acid-washed and pre-deashed with a 10% aqueous sulfuric acid solution at 80°C for 1.5 hours, and then the residual acid in the material was washed with deionized water at 20°C and dried at 80°C for 8 hours;

[0056] (3) Pre-oxidation and carbonization: 20 g of the material obtained after acid washing and pre-deashing as above was taken and pre-oxidized at 20-300 ° C in an air atmosphere at a heating rate of 5 ° C / min for 56 min; then the atmosphere was switched to a nitrogen atmosphere, and the temperature was continued to be increased to 600 ° C at a heating rate of 3 ° C / min, and carbonized at this temperature for 30 min to obtain a carbonized material (pre-oxidation carbonization yield was about 70%).

[0057] (4) Activation: Using potassium hydroxide as an alkaline activator, grind and mix the alkaline activator and the carbonized material in a mass ratio of 4:1. After the mixture is uniform, activate it at an activation temperature of 820°C for 1 hour under nitrogen protection to obtain an activated material (the activation yield can reach more than 75%).

[0058] (5) The activated material was acid-washed with a 10% aqueous hydrofluoric acid solution at 80°C for 1.5 h. The residual acid in the material was then washed with deionized water at 20°C and dried at 80°C for 8 h to obtain a porous carbon material (Product A). The total yield of the carbon material product was approximately 52%.

[0059] Comparative Example 1 (not pre-oxidized):

[0060] The method for preparing porous carbon material using Heishan coal as raw material comprises the following steps:

[0061] (1) crushing the Heishan coal raw material and then grinding and screening it to a particle size of 325 mesh;

[0062] (2) Pre-deashing: The Heishan coal powder after raw grinding and screening was acid-washed and pre-deashed with a 10% sulfuric acid aqueous solution at 80°C for 1.5 hours, and then the residual acid in the material was washed with deionized water at 20°C and dried at 80°C for 8 hours;

[0063] (3) Carbonization: Take 20 g of the material obtained after acid washing and pre-deashing, and in a nitrogen atmosphere, first heat the system from 20°C to 300°C at a heating rate of 5°C / min, then continue to heat it to 600°C at a heating rate of 3°C / min, and keep it at this temperature for 30 minutes for carbonization treatment to obtain a carbonized material;

[0064] (4) Activation: Using potassium hydroxide as an alkaline activator, grinding and mixing according to a mass ratio of alkaline activator to carbonized material of 4:1, after mixing evenly, activating the mixture at an activation temperature of 820°C for 1 hour under nitrogen protection to obtain an activated material;

[0065] (5) Post-treatment: The activated material was acid-washed with a 10% hydrofluoric acid aqueous solution at 80°C for 1.5 h, and then the residual acid in the material was washed with deionized water at 20°C and dried at 80°C for 8 h to obtain a carbon material (Product B).

[0066] Table 1 Performance test results of the products obtained in Example 1 and Comparative Example 1

[0067]

[0068] The iodine value can reflect the micropore content in the product to a certain extent. As shown in Table 1, the iodine value and specific surface area of ​​the product A obtained by performing a pre-oxidation treatment step in the process of Example 1 are significantly higher than those of the product B obtained in Comparative Example 1 (without the pre-oxidation treatment step).

[0069] Comparative Example 2 (traditional physical activation):

[0070] The method for preparing porous carbon material using Heishan coal as raw material comprises the following steps:

[0071] (1) crushing the Heishan coal raw material and then grinding and screening it to a particle size of 325 mesh;

[0072] (2) Carbonization: 20 g of ground and sieved Heishan coal powder was taken, and the temperature was first raised from 20°C to 300°C at a heating rate of 5°C / min in a nitrogen atmosphere, and then further raised to 600°C at a heating rate of 3°C / min, and kept at this temperature for 30 min for carbonization treatment to obtain a carbonized material;

[0073] (3) Activation: After the system temperature rises to 850°C, water vapor is introduced into the obtained carbonized material at a flow rate of 5 mL / min for 3 h to perform activation treatment to obtain a carbon material (Product C).

[0074] Comparative Example 3 (traditional chemical activation):

[0075] The method for preparing porous carbon material using Heishan coal as raw material comprises the following steps:

[0076] (1) crushing the Heishan coal raw material and then grinding and screening it to a particle size of 325 mesh;

[0077] (2) 20 g of ground and sieved Heishan coal powder was taken, potassium hydroxide was used as an alkaline activator, and the mixture was ground and mixed according to a mass ratio of alkaline activator to coal powder of 4:1. After the mixture was uniformly mixed, the system was heated from 20°C to 820°C at a heating rate of 5°C / min under a nitrogen atmosphere to perform an activation reaction to obtain an activated material;

[0078] (3) The residual alkali solution in the reaction material was washed with deionized water at 20°C and then dried at 80°C for 8 hours to obtain a carbon material (Product D). The total yield of the carbon material product was about 46%.

[0079] Table 2 Performance test results of the products obtained in Example 1 and Comparative Examples 2-3

[0080]

[0081] Comparative Example 2 used traditional physical activation to prepare carbon materials. No pre-deashing and pre-oxidation treatments were performed prior to carbonization, and water vapor was used as the activator during the activation process. The resulting product, Product C, had a high ash content and a low iodine value and specific surface area. Comparative Example 3 used traditional chemical activation to prepare carbon materials. Chemical activation was performed by directly mixing an alkaline activator with pulverized coal. The resulting product, Product D, had a high ash content and a low iodine value and specific surface area.

[0082] Example 2

[0083] The preparation method of the ultra-low ash, high specific surface area porous carbon material was similar to that of Example 1, except that in the pre-oxidation treatment of step (3), the heating rate was changed to 3°C / min, the pre-oxidation temperature range was changed to 20-350°C, and the pre-oxidation time was changed to 110 minutes. The remaining steps were the same as those of Example 1. A porous carbon material (Product E) was obtained.

[0084] Example 3

[0085] The preparation method of the ultra-low ash, high specific surface area porous carbon material was similar to that of Example 1, except that in the carbonization treatment of step (3), the carbonization heating rate was changed to 5°C / min, and the final carbonization temperature was changed to 650°C. The remaining steps were the same as those of Example 1. A porous carbon material (Product F) was obtained.

[0086] Example 4

[0087] The preparation method of the ultra-low ash, high specific surface area porous carbon material was similar to that of Example 1, except that in step (4) of the activation treatment, the mass ratio of the grinding and mixing of the alkaline activator and the carbonized material was changed to 4.5:1. The remaining steps were the same as those of Example 1. A porous carbon material (Product G) was obtained.

[0088] Example 5

[0089] The preparation method of the ultra-low ash and high specific surface area porous carbon material is similar to that of Example 1, except that in step (4), the activation temperature is changed to 850°C. The remaining steps are the same as those of Example 1. A porous carbon material (Product H) is obtained.

[0090] Table 3 Performance test results of the products obtained in Examples 2-4

[0091]

[0092] By adopting the technical solution of the present invention, low-ash, low-sulfur and high-calorific value Heishan coal is selected as raw material. Through the one-step preparation process of raw material pretreatment - chemical activation - post-deashing, the ash content of the obtained carbon material product can be controlled below 1%, and the specific surface area is higher than 2000m 2 / g; at the same time, it makes the preparation process simpler and the cost lower, achieving a balance between simplifying the process and ensuring product quality.

[0093] While various embodiments of the present invention have been described above, the above description is intended to be illustrative, not exhaustive, and not limited to the disclosed embodiments. Many modifications and variations will be apparent to those skilled in the art without departing from the spirit of the present invention.

Claims

1. A method for preparing a porous carbon material using Heishan coal as raw material, characterized in that: The following steps are involved: (1) Raw material screening: crush the Black Mountain coal, grind it into powder and screen it; (2) Pre-deashing: The screened Heishan coal raw material is acid-washed and pre-deashed, then washed with water to remove residual acid in the raw material and dried; (3) Pre-oxidation and carbonization: The material obtained from the pre-deashing process is pre-oxidized; the product after pre-oxidation is then carbonized to obtain a carbonized material; (4) Activation: Grinding and mixing the obtained carbonized material with an alkaline activator, and performing an activation treatment to obtain an activated material; (5) Post-treatment: The activated material is subjected to acid washing, then washed with water to remove the residual acid in the material and dried to obtain a porous carbon product.

2. The preparation method according to claim 1, characterized in that The particle size range of the Heishan coal after grinding and screening is 200 mesh-500 mesh.

3. The preparation method according to claim 1 or 2, characterized in that The acid solution used for the pickling pre-deashing in step (2) is selected from one or more of hydrochloric acid aqueous solution, sulfuric acid aqueous solution, nitric acid aqueous solution, hydrofluoric acid aqueous solution and oxalic acid aqueous solution; preferably sulfuric acid aqueous solution; The concentration of the acid solution is 2wt%-15wt%; The process conditions of pickling and pre-deashing include: pickling temperature of 50-90° C., and pickling time of 0.25 h to 2 h.

4. The preparation method according to any one of claims 1 to 3, characterized in that The process conditions of the pre-oxidation treatment in step (3) include: a treatment temperature of 20-350°C, a heating rate of 2-10°C / min, and a treatment time of 30-165min; and the atmosphere of the pre-oxidation treatment is air.

5. The preparation method according to any one of claims 1 to 4, characterized in that The process conditions of the carbonization treatment in step (3) include: a treatment temperature of 250-650°C, a heating rate of 2-10°C / min, a final treatment temperature holding time of 0-1.5h, and a nitrogen atmosphere for the carbonization treatment.

6. The preparation method according to any one of claims 1 to 5, characterized in that The alkaline activator is selected from one or more of sodium hydroxide, potassium hydroxide, potassium carbonate, potassium bicarbonate, sodium carbonate and sodium bicarbonate; The mass ratio of the alkaline activator to the carbonized material during grinding and mixing is in the range of 1:1-5:

1.

7. The preparation method according to any one of claims 1 to 6, characterized in that The process conditions of the activation treatment in step (4) include: a treatment temperature of 650-850° C., a treatment time of 0.5-2 h, and a nitrogen atmosphere for the activation treatment.

8. The preparation method according to any one of claims 1 to 7, characterized in that The acid solution used for the pickling post-treatment in step (5) is selected from one or more of a hydrochloric acid aqueous solution, a sulfuric acid aqueous solution, a nitric acid aqueous solution, a hydrofluoric acid aqueous solution and an oxalic acid aqueous solution; The concentration of the acid solution is 2wt%-15wt%; The process conditions of the pickling post-treatment include: a treatment temperature of 50-90° C. and a treatment time of 0.25 h to 2 h.

9. The preparation method according to any one of claims 1 to 8, characterized in that The water washing temperature in step (5) is 20-80°C, and the sample is dried at a temperature of 70-100°C after washing, and the drying time is 2-12h.

10. The porous carbon material obtained by the preparation method according to any one of claims 1 to 9.

Images