Long flame coal-based granular carbon as well as preparation method and application thereof

Abstract

The invention discloses long flame coal-based granular carbon as well as a preparation method and application thereof, which comprises the following steps: crushing and screening long flame coal, dipping into a sodium carbonate and potassium acetate solution, drying, and pyrolyzing to obtain coal gas, tar and semicoke. And further grinding the semicoke to 200 meshes, adding ramie powder, mesophase pitch, sodium carboxymethyl cellulose and water, uniformly stirring, extruding into strips, airing, cutting into columnar carbon, and activating with water vapor to obtain the granular carbon. When the columnar carbon is prepared, the used main component is semicoke obtained by dipping and pyrolyzing the long flame coal, and deep processing and utilization of the semicoke can be realized; the CMC plays a role of a binding agent and replaces traditional coal tar which is seriously polluted; the ramie powder is added to improve the pore structure of the granular carbon and increase the iodine value of the granular carbon. The method is simple and feasible, graded utilization of the long flame coal is achieved, green preparation of the granular carbon is also achieved, the iodine value of the obtained granular carbon is large, and the method has wide application prospects in the fields of waste gas purification and the like.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of coal grading high-value utilization, and particularly relates to a method for grading utilization of long flame coal and preparation of granular carbon from pyrolysis semi-coke of the long flame coal, namely a long flame coal-based granular carbon and a preparation method and application thereof. BACKGROUND

[0002] With the acceleration of the process of global economic integration, it has become an important direction of the development strategy of the world energy industry to develop the coal-based energy industry by using advanced and reliable technologies.

[0004] High-quality coal is mainly used in the fields of metallurgy and chemical industry. Low-rank coal has low carbon content and low calorific value, and has large heat loss and serious environmental pollution during combustion. In the past, the exploration, mining and research and development of low-rank coal were not sufficient. Under the current situation of global energy shortage, the economic value of low-rank coal and its related processing and production technology have been valued by the world and domestic energy industry.

[0005] Further development and utilization of long flame coal and other low-rank coal has become the development direction of coal energy utilization. Therefore, it is necessary to use advanced long flame coal upgrading and clean technology to improve the utilization efficiency of coal resources, enrich the energy utilization form, and reduce pollution.

[0006] The direct combustion of long flame coal and other low-rank coal has low thermal efficiency and large greenhouse gas emissions, and is difficult to be developed and utilized on a large scale. Therefore, the conversion and utilization of long flame coal as raw material are limited, and it is difficult to meet the quality requirements of various users without processing. In summary, long flame coal comprehensive utilization technology is the key to efficient utilization of this coal. At present, the preparation of coal-based granular carbon generally uses coal, coal tar and water as raw materials to prepare columnar carbon, and then activates the columnar carbon to obtain granular carbon. There is no public report on the preparation of new columnar carbon from semi-coke, ramie powder, CMC, mesophase pitch and water obtained by pyrolysis of long flame coal, and there is no public report on the preparation of long flame coal-based granular carbon from the new columnar carbon. SUMMARY

[0007] The application provides a long flame coal-based granular carbon and a preparation method and application thereof, to solve the problems of low thermal efficiency and large greenhouse gas emissions of direct combustion of long flame coal.

[0008] To achieve the above-mentioned purpose, the technical scheme adopted by the application is as follows:

[0009] The application discloses a preparation method of long-flame coal-based granular carbon, and belongs to the technical field of coal-based carbon.

[0010] Further, the initial raw material used is long-flame coal, and the product is obtained through two-stage reaction. In the first-stage reaction, coal gas, tar and semi-coke are obtained through impregnation and pyrolysis. In the second-stage reaction, the semi-coke obtained in the first-stage reaction is used as the main raw material, and long-flame coal-based granular carbon is obtained through the addition of ramie powder, mesophase pitch, CMC and water.

[0011] The application discloses a preparation method of long-flame coal-based granular carbon, and belongs to the technical field of coal-based carbon.

[0012] Step one, long-flame coal is crushed and sieved, and long-flame coal particles with a particle size of 16-40 meshes are selected as raw materials and are impregnated in a mixed solution of sodium carbonate and potassium acetate at room temperature for 10-24 hours, then filtered, dried at 60 DEG C, and then transferred into a tube furnace for pyrolysis at 500-700 DEG C for 30-90 minutes, and then cooled immediately after the pyrolysis is completed; during the pyrolysis, the pyrolysis volatile components are condensed and collected through a cold trap (-20 DEG C) provided with methanol at the rear end of the reaction tube, liquid tar products are obtained, and the chemical composition is detected and analyzed through a gas chromatograph-mass spectrometer; the pyrolysis gas products are collected through a gas bag, and the gas composition is analyzed through a gas chromatograph; and the solid product obtained after the pyrolysis is semi-coke;

[0013] Step two, the semi-coke obtained in step one is ground to 200 mesh, the semi-coke ground to 200 mesh, mesophase pitch, ramie powder, CMC and distilled water are added into a stirring kettle respectively, and stirred and mixed for 10-30 min, the uniformly stirred mixture is sent into a punch machine for pressing and molding, a cylindrical mold is used to obtain columnar carbon with a diameter of 4 mm, and the columnar carbon is naturally dried at room temperature for 3 days, the columnar carbon with a length of 4-8 mm and a diameter of 4 mm is cut and transferred into a tube furnace, when the tube furnace is heated to 500 DEG C, distilled water is started to be injected, the volume flow rate of the distilled water is controlled by a peristaltic pump, the injected water is injected into the heating zone of the tube furnace and rapidly vaporized to generate water vapor under high-temperature environment, the activation time of the water vapor is 1-4 h, and the columnar carbon is rapidly cooled to room temperature after the activation is completed, and the long-flame coal-based granular carbon is obtained.

[0014] Further, in step one, the concentration of sodium carbonate or potassium acetate in the mixed solution of sodium carbonate and potassium acetate ranges from 0.2 w.t.% to 5 w.t.%, and the volume ratio of long-flame coal to the mixed solution of sodium carbonate and potassium acetate ranges from 1:2 to 10.

[0015] Further, in step one, the temperature of the cold trap is -20 DEG C.

[0016] Further, in step two, the mass ratio of the semi-coke ground to 200 mesh, mesophase pitch, ramie powder, CMC and distilled water ranges from 100:5-20:5-20:2-10:10-50.

[0017] Further, in step two, when the water vapor is activated, the ratio of the mass of columnar carbon to the volume flow rate of distilled water ranges from 100 g:1-10 mL / min.

[0018] The long-flame coal-based granular carbon has an iodine value of up to 1028 mg / g.

[0019] The long-flame coal-based granular carbon is used for indoor air purification and industrial waste gas treatment, and can effectively adsorb VOCs such as formaldehyde and benzene.

[0020] Compared with the prior art, the present application has the following beneficial effects:

[0021] The present application realizes the staged utilization of long-flame coal, and the main components of the obtained long-flame coal-based granular carbon are H2, CO, CO2, CH4, C2H6, C2H4, C3H8, C3H6 and C4H 10The raw materials used in this invention are coal gas, coal tar (mainly composed of saturated aliphatic hydrocarbons), and loose, porous semi-coke. This invention utilizes loose, porous semi-coke as a raw material to prepare granular char, enabling deep processing and utilization of the semi-coke. Adding ramie powder improves the pore structure and increases the iodine value of the activated granular char. Using sodium carboxymethyl cellulose as a novel columnar char binder significantly reduces environmental pollution compared to the traditionally used, more polluting coal tar.

[0022] This invention is simple, feasible, and can be mass-produced. It realizes both the graded utilization of long-flame coal and the green preparation of granular char. Moreover, the iodine value of the obtained granular char is higher than that of some commercially available granular char. The prepared long-flame coal-based granular char has broad application prospects in environmental impact assessment, industrial tail gas purification, flue gas desulfurization, organic waste gas purification, and sewage filtration. Attached Figure Description

[0023] Figure 1 This is the XRD pattern of the long-flame coal in Example 2;

[0024] Figure 2 This is an SEM image of the semi-coke obtained after pyrolyzing the long-flame coal impregnated in Example 4 at 600℃ for 60 min.

[0025] Figure 3 This is a gas chromatogram of the gas produced after the impregnated long-flame coal in Example 4 was pyrolyzed at 600°C for 60 min.

[0026] Figure 4 This is the appearance of the tar collected with methanol after the impregnated long-flame coal in Example 4 was pyrolyzed at 600°C for 60 min;

[0027] Figure 5 This is an appearance diagram of granular carbon A in Example 7;

[0028] Figure 6 This is an appearance diagram of granular carbon B in Example 8;

[0029] Figure 7 This is the XRD pattern of particulate carbon B in Example 8;

[0030] Figure 8 This is a flowchart of the preparation method in this invention. Detailed Implementation

[0031] This invention includes a method for preparing granular char from semi-coke produced by long-flame coal pyrolysis, and its application.

[0032] Example 1: The method for obtaining coal gas, tar, and semi-coke by impregnation and pyrolysis of long-flame coal includes: crushing and sieving long-flame coal, weighing 100 g of long-flame coal particles with a particle size of 16-40 mesh as raw material, impregnating them in 500 mL of a mixture of 0.5% sodium carbonate and 1% potassium acetate at room temperature for 10 h, then filtering, drying the impregnated long-flame coal at 60℃, and then transferring it to a tube furnace for pyrolysis at 500℃ for 30 min. After pyrolysis, the temperature is immediately lowered. The pyrolysis volatiles during the pyrolysis process are condensed and collected through a cold trap (-20℃) containing methanol at the rear end of the reaction tube to obtain liquid tar product. The pyrolysis gaseous product is collected through a gas bag. The solid product obtained after pyrolysis is semi-coke.

[0033] Example 2: This example differs from Example 1 in that the long-flame coal used in this example is No. 8 coal from the No. 106 coal mine of China Coal Energy Xinjiang Tianshan Coal and Electricity Co., Ltd. Figure 1 This is the XRD pattern of coal seam No. 8 from coal mine No. 106. The XRD pattern shows a broad diffraction peak near the diffraction angle 2θ = 25°, indicating a low degree of graphitization. Furthermore, strong diffraction peaks appear at 2θ = 29.7° and 30.9°, corresponding to the diffraction peaks of other impurity minerals in the long-flame coal.

[0034] Example 3: This example differs from Examples 1 or 2 in that the method for obtaining coal gas, tar, and semi-coke through impregnation and pyrolysis of long-flame coal includes: crushing and screening coal No. 8 from the No. 106 coal mine of China Coal Energy Xinjiang Tianshan Coal and Electricity Co., Ltd., weighing 100 g of the above-mentioned long-flame coal particles with a particle size of 16-40 mesh as raw material, impregnating them in 500 mL of a mixed solution of 2% sodium carbonate and 2% potassium acetate at room temperature for 16 h, then filtering, drying the impregnated long-flame coal at 60 ℃, and then transferring it into a tube furnace for pyrolysis at 700 ℃ for 60 min, followed by immediate cooling after pyrolysis. The pyrolysis volatiles generated during the pyrolysis process are condensed and collected through a cold trap (-20 ℃) ​​containing methanol at the rear end of the reaction tube to obtain liquid tar product, and the pyrolysis gaseous products are collected through a gas bag. The solid product obtained after pyrolysis is semi-coke.

[0035] Example 4: This example differs from Examples 1-3 in that the method for obtaining coal gas, tar, and semi-coke through impregnation and pyrolysis of long-flame coal includes: crushing and screening coal No. 8 from the No. 106 coal mine of China Coal Energy Xinjiang Tianshan Coal and Electricity Co., Ltd., weighing 100 g of the above-mentioned long-flame coal particles with a particle size of 16-40 mesh as raw material, impregnating them in 500 mL of a mixture of 1% sodium carbonate and 1% potassium acetate at room temperature for 12 h, then filtering, drying the impregnated long-flame coal at 60 ℃, and then transferring it into a tube furnace for pyrolysis at 600 ℃ for 60 min, followed by immediate cooling after pyrolysis. The pyrolysis volatiles during the pyrolysis process are condensed and collected through a cold trap (-20 ℃) ​​containing methanol at the rear end of the reaction tube to obtain liquid tar product, the chemical composition of which is analyzed by gas chromatography-mass spectrometry; the pyrolysis gaseous products are collected through a gas bag and their gas composition is analyzed by gas chromatography; the solid product obtained after pyrolysis is semi-coke.

[0036] Figure 2 This is a SEM image of the semi-coke obtained after pyrolyzing long-flame coal impregnated in a mixture of 1% sodium carbonate and 1% potassium acetate in Example 4 at 600°C for 60 min. As can be seen from the image, most of the semi-coke retains the blocky structure of the long-flame coal, while some of the semi-coke has been broken, and some large pores have been generated on the surface of the semi-coke. Figure 3 This is the gas chromatogram of the gas produced after pyrolysis of long-flame coal impregnated in a mixture of 1% sodium carbonate and 1% potassium acetate at 600 °C for 60 min, as described in Example 4. Figure 3 Analysis was performed to obtain the composition and volume concentration of the coal gas. The study showed that the coal gas obtained from pyrolysis accounted for 8.96% of the coal sample mass, and its main components were: H2, CO, CO2, CH4, C2H6, C2H4, C3H8, C3H6, and C4H4. 10 . Figure 4 The image shows the appearance of the tar solution collected with methanol after the long-flame coal impregnated in a mixture of 1% sodium carbonate and 1% potassium acetate by mass fraction in Example 4 was pyrolyzed at 600°C for 60 minutes. The image shows a brownish-yellow tar-methanol solution.

[0037] Example 5: This example differs from Examples 1-4 in that the semi-coke obtained in Example 2 is first ground to 200 mesh. Then, 100 g of semi-coke ground to 200 mesh, 8 g of mesophase pitch, 6 g of CMC, and 30 mL (equivalent to 30 g) of distilled water are added to a stirred tank and mixed for 30 min. The uniformly mixed mixture is then fed into a press for mechanical pressing to form columnar carbon with a diameter of 4 mm using a columnar mold. The columnar carbon is then naturally dried at room temperature for 3 days. The columnar carbon is then cut to obtain novel columnar carbon with a length of 4-8 mm and a diameter of 4 mm. 50 g of the novel columnar carbon is transferred to a tube furnace. When the tube furnace is heated to 500 °C, distilled water is introduced. The volumetric flow rate of the distilled water is controlled at 2 mL / min using a peristaltic pump. The water is injected into the heating zone of the tube furnace through the peristaltic pump and rapidly vaporizes to generate water vapor under high temperature. The water vapor activation time is 1 h. After activation, the mixture is rapidly cooled to room temperature to obtain long-flame coal-based granular carbon.

[0038] Example 6: This example differs from Examples 1-5 in that the semi-coke obtained in Example 3 is first ground to 200 mesh. Then, 100 g of semi-coke ground to 200 mesh, 8 g of mesophase pitch, 6 g of CMC, and 30 mL (equivalent to 30 g) of distilled water are added to a stirred tank and mixed for 30 min. The uniformly mixed mixture is then fed into a press for mechanical pressing to form columnar carbon with a diameter of 4 mm using a columnar mold. The columnar carbon is then naturally dried at room temperature for 3 days. The columnar carbon is then cut to obtain novel columnar carbon with a length of 4-8 mm and a diameter of 4 mm. 50 g of the novel columnar carbon is transferred to a tube furnace. When the tube furnace is heated to 500°C, distilled water is introduced. The volumetric flow rate of the distilled water is controlled at 1 mL / min using a peristaltic pump. The water is injected into the heating zone of the tube furnace through the peristaltic pump and rapidly vaporizes to generate water vapor under high temperature. The water vapor activation time is 3 h. After activation, the mixture is rapidly cooled to room temperature to obtain long-flame coal-based granular carbon.

[0039] Example 7: This example differs from Examples 1-6 in that the semi-coke obtained in Example 4 is first ground to 200 mesh. Then, 100 g of semi-coke ground to 200 mesh, 12 g of mesophase pitch, 4 g of CMC, and 30 mL (equivalent to 30 g) of distilled water are added to a mixing vessel and stirred for 30 min. The uniformly stirred mixture is then fed into a stamping press for pressing and mechanical stamping to form columnar carbon with a diameter of 4 mm using a columnar mold. The columnar carbon is then naturally dried at room temperature for 3 days. The columnar carbon is then cut to obtain novel columnar carbon with a length of 4-8 mm and a diameter of 4 mm. 50 g of the novel columnar carbon was transferred into a tubular furnace. When the furnace reached 500 °C, distilled water was introduced, with a peristaltic pump controlling the flow rate at 0.7 mL / min. The water was injected into the heating zone of the furnace via the peristaltic pump, rapidly vaporizing to generate steam at the high temperature. The steam activation time was 1.5 h. After activation, the mixture was rapidly cooled to room temperature to obtain long-flame coal-based granular carbon A. Figure 5 As shown, its iodine value was 757 mg / g after testing.

[0040] Example 8: This example differs from Examples 1-7 in that the semi-coke obtained in Example 4 is first ground to 200 mesh. Then, 100 g of semi-coke ground to 200 mesh, 12 g of mesophase pitch, 12 g of ramie powder, 4 g of CMC, and 30 mL (equivalent to 30 g) of distilled water are added to a mixing vessel and stirred for 30 min. The uniformly stirred mixture is then fed into a stamping press for pressing, mechanically stamped to form columnar carbon with a diameter of 4 mm using a columnar mold. The columnar carbon is then naturally dried at room temperature for 3 days. The columnar carbon is then cut to obtain novel columnar carbon with a length of 4-8 mm and a diameter of 4 mm. 50 g of the novel columnar carbon was transferred into a tubular furnace. When the furnace reached 500°C, distilled water was introduced, with a peristaltic pump controlling the flow rate at 0.7 mL / min. The water was injected into the heating zone of the furnace via the peristaltic pump, rapidly vaporizing to generate steam at the high temperature. The steam activation time was 1.5 h. After activation, the mixture was rapidly cooled to room temperature to obtain long-flame coal-based granular carbon B. Figure 6 As shown, its iodine value was 1028 mg / g, which is higher than that of granular charcoal A and commercially available granular charcoal with an iodine value of 800 mg / g. This indicates that the addition of ramie powder can effectively improve the pore structure of granular charcoal and increase its iodine value. Figure 7 This is the XRD pattern of particulate carbon B. The broad peaks observed at 2θ of about 24 and 43 degrees correspond to the diffraction peaks of the (002) and (100) crystal planes of the porous carbon material, respectively, indicating its amorphous morphological characteristics.

[0041] Example 9: This example differs from Examples 1-8 in that the method for obtaining coal gas, tar, and semi-coke by impregnation and pyrolysis of long-flame coal in this example includes: crushing and screening No. 8 coal from the No. 106 coal mine of China Coal Energy Xinjiang Tianshan Coal and Electricity Co., Ltd., weighing 100 g of the above-mentioned long-flame coal particles with a particle size of 16-40 mesh as raw material, impregnating them in 200 mL of a mixture of 0.2% sodium carbonate and 0.2% potassium acetate at room temperature for 12 h, then filtering, drying the impregnated long-flame coal at 60°C, and then transferring it into a tubular furnace for pyrolysis at 600°C for 60 min, and immediately cooling it after pyrolysis. During the pyrolysis process, the volatiles from the pyrolysis are condensed and collected in a cold trap (-20°C) containing methanol at the rear end of the reaction tube to obtain liquid tar products. The chemical composition of these products is analyzed using gas chromatography-mass spectrometry (GC-MS). The pyrolysis gaseous products are collected in a gas bag, and their gaseous components are analyzed using gas chromatography. The solid product obtained after pyrolysis is semi-coke. The semi-coke is ground to 200 mesh. Then, 100 g of semi-coke ground to 200 mesh, 5 g of mesophase pitch, 5 g of ramie powder, 2 g of CMC, and 10 mL (equivalent to 10 g) of distilled water are added to a stirred tank and stirred for 30 min. The homogeneous mixture is then fed into a press for mechanical pressing to form columnar carbon with a diameter of 4 mm using a columnar mold. The columnar carbon is then naturally dried at room temperature for 3 days. The columnar carbon is then cut to obtain novel columnar carbon with a length of 4–8 mm and a diameter of 4 mm. 50 g of the novel columnar carbon was transferred into a tube furnace. When the tube furnace was heated to 500°C, distilled water was introduced. The volumetric flow rate of the distilled water was controlled at 0.5 mL / min using a peristaltic pump. The introduced water was injected into the heating zone of the tube furnace through the peristaltic pump and rapidly vaporized to generate water vapor under high temperature. The water vapor activation time was 4 h. After activation, the carbon was rapidly cooled to room temperature to obtain long-flame coal-based granular carbon C.

[0042] Example 10: This example differs from Examples 1-9 in that the method for obtaining coal gas, tar, and semi-coke through impregnation and pyrolysis of long-flame coal in this example includes: crushing and screening coal No. 8 from the No. 106 coal mine of China Coal Energy Xinjiang Tianshan Coal and Electricity Co., Ltd., weighing 100 g of the above-mentioned long-flame coal particles with a particle size of 16-40 mesh as raw material, impregnating them in 1000 mL of a mixture of 5% sodium carbonate and 5% potassium acetate at room temperature for 12 h, then filtering, drying the impregnated long-flame coal at 60°C, and then transferring it to a tube furnace for pyrolysis at 600°C for 60 min, and immediately cooling after pyrolysis. The pyrolysis volatiles during the pyrolysis process are condensed and collected through a cold trap (-20°C) containing methanol at the rear end of the reaction tube to obtain liquid tar product, the chemical composition of which is detected and analyzed by gas chromatography-mass spectrometry; the pyrolysis gaseous products are collected through a gas bag and the gas composition is analyzed by gas chromatography; the solid product obtained after pyrolysis is semi-coke. The obtained semi-coke was ground to 200 mesh. Then, 100 g of semi-coke ground to 200 mesh, 20 g of mesophase pitch, 20 g of ramie powder, 10 g of CMC, and 50 mL (equivalent to 50 g) of distilled water were added to a stirred tank and stirred for 30 min. The uniformly stirred mixture was then fed into a press for pressing and mechanically shaped using a columnar mold to obtain columnar carbon with a diameter of 4 mm. The columnar carbon was then naturally dried at room temperature for 3 days. The columnar carbon was then cut to obtain a new type of columnar carbon with a length of 4-8 mm and a diameter of 4 mm. 50 g of the new columnar carbon was transferred into a tube furnace. When the tube furnace was heated to 500°C, distilled water was introduced. The volumetric flow rate of the distilled water was controlled at 5 mL / min using a peristaltic pump. The water was injected into the heating zone of the tube furnace through the peristaltic pump and rapidly vaporized to generate water vapor under high temperature. The water vapor activation time was 1 h. After activation, the mixture was rapidly cooled to room temperature to obtain long-flame coal-based granular carbon D.

[0043] Example 11: A long-flame coal-based granular charcoal is used for indoor air purification and industrial waste gas treatment. The long-flame coal-based granular charcoal can effectively adsorb VOCs such as formaldehyde and benzene. The iodine value of the long-flame coal-based granular charcoal can be as high as 1028 mg / g. The higher the iodine value, the stronger the ability to adsorb formaldehyde and other substances.

[0044] This invention discloses a long-flame coal-based granular char, its preparation method, and its applications. The method involves crushing and sieving long-flame coal, then impregnating it in a sodium carbonate and potassium acetate solution, drying it, and subsequently pyrolyzing it to obtain coal gas, tar, and semi-coke. The semi-coke is then further ground to 200 mesh, and ramie powder, mesophase pitch, sodium carboxymethyl cellulose (CMC), and water are added. After thorough mixing, the mixture is extruded, dried, and cut into columnar char, which is then activated with steam to obtain granular char. In preparing the columnar char, the main component used is the semi-coke obtained from the impregnation and pyrolysis of the aforementioned long-flame coal, enabling deep processing and utilization of the semi-coke. CMC acts as a binder, replacing the traditional, heavily polluting coal tar. The addition of ramie powder improves the pore structure of the granular char and increases its iodine value. This invention is simple and feasible, achieving both the graded utilization of long-flame coal and the green preparation of granular char. Furthermore, the obtained granular char has a high iodine value and broad application prospects in fields such as waste gas purification.

[0045] The above description is only a preferred embodiment of the present invention. It should be noted that for those skilled in the art, several improvements and modifications can be made without departing from the principle of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A method for preparing long-flame coal-based granular char, characterized in that, First, the long-flame coal is crushed and screened, then impregnated with a mixed solution of sodium carbonate and potassium acetate, dried, and pyrolyzed to obtain coal gas, tar, and semi-coke. The semi-coke obtained from pyrolysis is further ground to 200 mesh, and then ramie powder, mesophase pitch, sodium carboxymethyl cellulose (CMC), and water are added. After stirring evenly, the mixture is extruded, dried, and cut into columnar carbon. Finally, the columnar carbon is activated with steam to obtain long-flame coal-based granular carbon.

2. The method for preparing long-flame coal-based granular char according to claim 1, characterized in that, Includes the following steps: Step 1: Crush and screen the long-flame coal, selecting particles with a diameter of 16-40 mesh as raw material. Immerse the coal in a mixed solution of sodium carbonate and potassium acetate at room temperature for 10-24 hours. Then filter the mixture and dry it at 60°C. Transfer the dried coal to a tube furnace and pyrolyze it at 500-700°C for 30-90 minutes. Immediately after pyrolysis, cool the coal. The pyrolysis volatiles are condensed and collected in a methanol-filled cold trap at the rear of the reaction tube, yielding liquid tar. The chemical composition of this tar is analyzed using gas chromatography-mass spectrometry (GC-MS). The pyrolysis gaseous products are collected in a gas bag and analyzed using gas chromatography. The solid product obtained after pyrolysis is semi-coke. Step 2: Grind the semi-coke obtained in Step 1 to 200 mesh. Add the 200-mesh semi-coke, mesophase pitch, ramie powder, CMC, and distilled water to a mixing tank and mix for 10-30 minutes. Send the well-mixed mixture to a press for pressing. Mechanically press the mixture into shape using a columnar mold to obtain columnar carbon with a diameter of 4 mm. Let it dry naturally at room temperature for 3 days. Cut the columnar carbon to obtain columnar carbon with a length of 4-8 mm and a diameter of 4 mm. Transfer it to a tube furnace. When the tube furnace is heated to 500℃, start introducing distilled water. Use a peristaltic pump to control the volumetric flow rate of the distilled water. The water is injected into the heating zone of the tube furnace through the peristaltic pump and rapidly vaporizes to generate water vapor under high temperature. The water vapor activation time is 1-4 hours. After activation, quickly cool to room temperature to obtain long-flame coal-based granular carbon.

3. The method for preparing long-flame coal-based granular char according to claim 2, characterized in that, In step one, the concentration range of sodium carbonate or potassium acetate in the mixed solution of sodium carbonate and potassium acetate is 0.2 wt% to 5 wt%, and the volume ratio of long-flame coal to the mixed solution of sodium carbonate and potassium acetate is 1:2 to 10.

4. The method for preparing long-flame coal-based granular char according to claim 2, characterized in that, In step one, the temperature of the cold trap is -20 ℃.

5. The method for preparing long-flame coal-based granular char according to claim 2, characterized in that, In step two, the mass ratio of semi-coke, mesophase pitch, ramie powder, CMC and distilled water ground to 200 mesh is 100: 5~20: 5~20: 2~10: 10~50.

6. The method for preparing long-flame coal-based granular char according to claim 2, characterized in that, In step two, during steam activation, the ratio of the mass of columnar charcoal to the volumetric flow rate of distilled water is 100 g : 1~10 mL / min.

7. The long-flame coal-based granular char obtained by the preparation method according to any one of claims 1-6, characterized in that, The iodine value of the long-flame coal-based granular char is as high as 1028 mg / g.

8. The application of the long-flame coal-based granular charcoal according to claim 7, characterized in that, The long-flame coal-based granular charcoal is used for indoor air purification and industrial waste gas treatment.

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