Porous biochar material and its manufacturing method

Abstract

To provide a method of manufacturing a multi-porous biomass carbon material which can effectively simplify the manufacturing process and enhance the economic value of the product.SOLUTION: Provided is a method of manufacturing a multi-porous biomass carbon material, comprising: a material preparation step S1 of preparing a raw material mixture by evenly mixing a biomass carbon source and an oxidant at a stirring temperature; a reduction-oxidation step S2 of heating the raw material mixture in an oxygen-deficient environment to induce self-combustion, thereby subjecting the raw material mixture to a reduction-oxidation reaction to obtain an original product; a first-pickling-drying step S3 of pickling the original product to obtain a first pickled product, and then drying the first pickled product to obtain a dried product; a heat treatment step S4 of heating the dried product at a heat treatment temperature in an oxygen-deficient to obtain a volatile-component-removed product; and a second-pickling-drying step S5 of making the second pickled product become the multi-porous biomass carbon material.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to biochar materials and methods for producing the same, in particular to porous biochar materials and methods for producing the same. [Background technology]

[0002] Taiwan generates an average of 1 million tons of agricultural waste annually, but much of it was randomly disposed of, such as by landfilling or incineration on site, and therefore could not be effectively reused. Biochar materials are products produced by pyrolysis of biomass, and have a dual carbon reduction effect on the environment and resources. In recent years, scientists around the world have found that agricultural waste can be used as raw material for biochar materials.

[0003] However, the process of producing biochar materials from agricultural waste is time- and energy-intensive, and the economic value of the biochar materials produced by conventional techniques is difficult to increase. Therefore, it is necessary to improve the conventional production methods. Summary of the Invention

[0004] Therefore, an object of the present invention is to provide a porous biochar material and a method for producing the same, so that the production process can be simplified and the economic value of the product can be increased.

[0005] In order to solve the problems of the prior art, the present invention provides a method for producing a porous biochar material, comprising: a material preparation step of uniformly mixing a biomass carbon source, which is glucose or lignin, and an oxidizing agent, which is potassium nitrate or ammonium nitrate, by stirring at a mixing temperature to obtain a raw material mixture; an oxidation-reduction step of heating the raw material mixture to cause spontaneous combustion in a low-oxygen state, and oxidizing and reducing the raw material mixture to obtain a raw product; a first pickling and drying step of pickling the raw product to obtain a first pickling product, washing the first pickling product to a neutral state with deionized water and drying to obtain a dried product; a heat treatment step of heating the dried product at a heat treatment temperature in a low-oxygen state to remove volatile components remaining in the dried product to obtain a volatile component-removed product; and a second pickling and drying step of pickling the volatile component-removed product to obtain a second pickling product, washing the second pickling product to a neutral state with deionized water and drying to obtain a porous biochar material.

[0006] In one embodiment of the present invention, a method for producing a porous biochar material is provided, which further includes a cooling and fixing step between the material preparation step and the oxidation and reduction step, in which the raw material mixture is placed in a quartz tube and cooled and fixed to obtain the cooled and fixed raw material mixture, and in the oxidation and reduction step, the cooled and fixed raw material mixture is oxidized and reduced to obtain the primitive product.

[0007] In one embodiment of the present invention, there is provided a method for producing a porous biochar material, characterized in that a polishing process is further included between the oxidation-reduction process and the pickling and drying process, in which the raw product is polished to obtain a polished product, and in the first pickling and drying process, the polished product is pickled to obtain the first pickled product, and the first pickled product is dried to obtain the dried product.

[0008] In one embodiment of the present invention, Material preparation processThe present invention provides a method for producing a porous biochar material, characterized in that the biomass carbon source and the oxidant are uniformly mixed by directly mixing the powders or by using a solvent-assisted method to obtain the raw material mixture, and the solvent used in the solvent-assisted method is water or alcohol.

[0009] In one embodiment of the present invention, there is provided a method for producing a porous biochar material, wherein the raw material mixture contains 10 to 90 mass% of the biomass carbon source and 10 to 90 mass% of the oxidizing agent.

[0010] In one embodiment of the present invention, there is provided a method for producing a porous biochar material, wherein the mixing temperature in the material preparation step is 200°C to 400°C.

[0011] In one embodiment of the present invention, there is provided a method for producing a porous biochar material, wherein the heat treatment temperature in the heat treatment step is 700°C to 900°C. Effect of the Invention

[0012] The technical means adopted in the preparation method of the porous biochar material of the present invention not only simplify the preparation process, but also produce porous biochar material with a high surface area, thereby increasing the economic value of the product. [Brief description of the drawings]

[0013] [Figure 1] FIG. 1 is a flow diagram of a method for producing porous biochar material according to an embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0014] Hereinafter, an embodiment of the present invention will be described with reference to Fig. 1. The description is merely an example of an embodiment of the present invention, and is not intended to limit the embodiment of the present invention.

[0015] As shown in FIG. 1, the method for producing porous biochar material according to an embodiment of the present invention includes the following steps: a material preparation step S1, in which a raw material mixture is obtained by evenly mixing a biomass carbon source, which is glucose or lignin, and an oxidizing agent, which is potassium nitrate or ammonium nitrate, in a stirring manner at a mixing temperature.

[0016] As shown in FIG. 1, the method for producing a porous biochar material according to an embodiment of the present invention includes an oxidation-reduction step S2 in which the raw material mixture is heated and spontaneously combusted under a low-oxygen condition, and the raw material mixture is oxidized and reduced to obtain a primitive product.

[0017] As shown in FIG. 1, in the method for producing a porous biochar material according to an embodiment of the present invention, between the material preparation step S1 and the oxidation-reduction step S2, a cooling and fixing step S1 is further included, in which the raw material mixture is put into a quartz tube and cooled and fixed to obtain the cooled and fixed raw material mixture, and the raw product is obtained by oxidizing and reducing the cooled and fixed raw material mixture in the oxidation-reduction step S2.

[0018] As shown in FIG. 1, a method for producing a porous biochar material according to an embodiment of the present invention includes a first pickling and drying step S3, in which the raw product is pickled to obtain a first pickled product, and the first pickled product is neutrally washed with deionized water and dried to obtain a dried product.

[0019] As shown in FIG. 1, in the method for producing a porous biochar material according to an embodiment of the present invention, a polishing process S21 is further included between the oxidation-reduction process S2 and the pickling and drying process S3, in which the raw product is polished to obtain a polished product, and in the first pickling and drying process, the polished product is pickled to obtain the first pickling product, and the first pickling product is dried to obtain the dried product.

[0020] As shown in FIG. 1, a method for producing a porous biochar material according to an embodiment of the present invention includes a heat treatment step S4 in which the dried product is heated at a heat treatment temperature under a low oxygen condition to remove volatile components remaining in the dried product, thereby obtaining a devolatilized product.

[0021] As shown in FIG. 1, a method for producing a porous biochar material according to an embodiment of the present invention includes a second pickling and drying step S5 in which the volatile component removal product is pickled to obtain a second pickled product, and the second pickled product is neutrally washed with deionized water and dried to obtain a porous biochar material.

[0022] As shown in FIG. 1, a method for producing a porous biochar material according to an embodiment of the present invention includes: Material preparation process In the method, the biomass carbon source and the oxidant are mixed evenly by directly mixing the powders or by using a solvent-assisted method to obtain the raw material mixture, and the solvent used in the solvent-assisted method is water or alcohol.

[0023] In the method for producing a porous biochar material according to an embodiment of the present invention, the raw material mixture contains 10 to 90% by mass of the biomass carbon source and 10 to 90% by mass of the oxidizing agent.

[0024] As shown in FIG. 1, in the method for producing a porous biochar material according to an embodiment of the present invention, the mixing temperature in the material preparation step is 200° C. to 400° C.

[0025] As shown in FIG. 1, in the method for producing a porous biochar material according to an embodiment of the present invention, the heat treatment temperature is 700°C to 900°C in the heat treatment step.

[0026] More specifically, the embodiments of the present invention are experimented with different mass% ratios of the raw material mixture, which are respectively designated as embodiment 1, embodiment 2, embodiment 3, embodiment 4 and embodiment 5. The contents of these embodiments are described in more detail below.

[0027] EMBODIMENT 1

[0028] In the material preparation step S1, the biomass carbon source is glucose, the oxidizing agent is potassium nitrate, and 93.26 g of the raw material mixture is obtained by stirring 50% by mass of glucose and 50% by mass of potassium nitrate at 230°C. In the cooling and fixing step S11, the raw material mixture is put into a quartz tube and cooled and fixed to obtain the cooled and fixed raw material mixture. In the oxidation and reduction step S2, a stable nitrogen atmosphere is introduced (nitrogen flow rate: 820 Standard Cubic Centimeters per Minute (SCCM)) to create a low-oxygen atmosphere, the cooled and fixed raw material mixture is heated and spontaneously combusted in the low-oxygen atmosphere, and when the raw material mixture begins to spontaneously combust, heating is stopped, and oxidation and reduction are performed by the spontaneous combustion of the raw material mixture to obtain the primitive product. The nitrogen atmosphere continues to flow steadily during the oxidation and reduction reaction, and the primitive product is taken out after the environmental temperature has cooled to room temperature. In the polishing step S21, the primitive product is polished to obtain the polished product. In the first pickling and drying step S3, the polished product is pickled with 35% by mass hydrochloric acid to obtain the first pickled product, the first pickled product is washed with deionized water to neutrality, and the first pickled product is dried at 105°C until the next day to obtain the dried product. In the heat treatment step S4, the dried product is placed in a crucible, a stable nitrogen atmosphere is introduced (nitrogen flow rate: 5542 SCCM) to create a low-oxygen atmosphere, and the dried product is heated and fired for 2 hours at the heat treatment temperature of 800°C to remove residual volatile components of the dried product to obtain the volatile component-removed product. In the second pickling and drying step S5, the volatile component-removed product is pickled with 35% by mass hydrochloric acid to obtain the second pickled product, the second pickled product is washed with deionized water to neutrality, and the second pickled product is dried at 105°C until the next day to form the second pickled product into a porous biochar material. The weight of the obtained porous biochar material was 1.315 g and the surface area measured by BET was 2526.74 m 2 / g.

[0029] More specifically, the 35 mass % hydrochloric acid used in the first pickling and drying step S3 and the second pickling and drying step S5 can be replaced with another acid solution for pickling.

[0030] EMBODIMENT 2

[0031] In the material preparation step S1, the biomass carbon source is glucose, the oxidizing agent is potassium nitrate, and 61.86 g of the raw material mixture is obtained by stirring 80 mass% glucose and 20 mass% potassium nitrate at 230°C. In the cooling and fixing step S11, the raw material mixture is put into a quartz tube and cooled and fixed to obtain the cooled and fixed raw material mixture. In the oxidation and reduction step S2, a stable nitrogen atmosphere is introduced (nitrogen flow rate: 281 SCCM) to create a low-oxygen atmosphere, and the cooled and fixed raw material mixture is heated in the low-oxygen atmosphere to cause spontaneous combustion. However, since the raw material mixture with this mass% ratio is difficult to spontaneously combust, it is necessary to continue heating the raw material mixture even when it begins to spontaneously combust, and the primitive product is obtained by performing oxidation and reduction through the spontaneous combustion of the raw material mixture. In the polishing step S21, the primitive product is polished to obtain the polished product. In the first pickling and drying step S3, the polished product is pickled with 35% by mass hydrochloric acid to obtain the first pickled product, the first pickled product is washed with deionized water to neutrality, and the first pickled product is dried at 105°C until the next day to obtain the dried product. In the heat treatment step S4, the dried product is placed in a crucible, a stable nitrogen atmosphere is introduced (nitrogen flow rate: 5542 SCCM) to create a low-oxygen atmosphere, and the dried product is heated and fired for 2 hours at the heat treatment temperature of 800°C to remove residual volatile components of the dried product to obtain the volatile component-removed product. In the second pickling and drying step S5, the volatile component-removed product is pickled with 35% by mass hydrochloric acid to obtain the second pickled product, the second pickled product is washed with deionized water to neutrality, and the second pickled product is dried at 105°C until the next day to form the second pickled product into a porous biochar material. The weight of the obtained porous biochar material was 2.612 g and the surface area measured by BET was 549.34 m 2 / g.

[0032] EMBODIMENT 3

[0033] In the material preparation step S1, the biomass carbon source is glucose, the oxidizing agent is potassium nitrate, and 76.60 g of the raw material mixture is obtained by stirring 70% by mass of glucose and 30% by mass of potassium nitrate at 230°C. In the cooling and fixing step S11, the raw material mixture is put into a quartz tube and cooled and fixed to obtain the cooled and fixed raw material mixture. In the oxidation and reduction step S2, a stable nitrogen atmosphere is introduced (nitrogen flow rate: 281 SCCM) to create a low-oxygen atmosphere, the cooled and fixed raw material mixture is heated and spontaneously combusted in the low-oxygen atmosphere, and when the raw material mixture begins to spontaneously combust, heating is stopped, and oxidation and reduction are performed by the spontaneous combustion of the raw material mixture to obtain the primitive product. The nitrogen atmosphere continues to flow steadily during the oxidation and reduction reaction, and the primitive product is taken out after the environmental temperature has cooled to room temperature. In the polishing step S21, the primitive product is polished to obtain the polished product. In the first pickling and drying step S3, the polished product is pickled with 35% by mass hydrochloric acid to obtain the first pickled product, the first pickled product is washed with deionized water to neutrality, and the first pickled product is dried at 105°C until the next day to obtain the dried product. In the heat treatment step S4, the dried product is placed in a crucible, a stable nitrogen atmosphere is introduced (nitrogen flow rate: 5542 SCCM) to create a low-oxygen atmosphere, and the dried product is heated and fired for 2 hours at the heat treatment temperature of 800°C to remove residual volatile components of the dried product to obtain the volatile component-removed product. In the second pickling and drying step S5, the volatile component-removed product is pickled with 35% by mass hydrochloric acid to obtain the second pickled product, the second pickled product is washed with deionized water to neutrality, and the second pickled product is dried at 105°C until the next day to form the second pickled product into a porous biochar material. The weight of the obtained porous biochar material was 4.85 g, and the surface area measured by BET was 763.61 m 2 / g.

[0034] EMBODIMENT 4

[0035] In the material preparation step S1, the biomass carbon source is glucose, the oxidizing agent is potassium nitrate, and 54.75 g of the raw material mixture is obtained by stirring 60 mass% glucose and 40 mass% potassium nitrate at 230°C. In the cooling and fixing step S11, the raw material mixture is put into a quartz tube and cooled and fixed to obtain the cooled and fixed raw material mixture. In the oxidation and reduction step S2, a stable nitrogen atmosphere is introduced (nitrogen flow rate: 402 SCCM) to create a low-oxygen atmosphere, the cooled and fixed raw material mixture is heated and spontaneously combusted in the low-oxygen atmosphere, and when the raw material mixture begins to spontaneously combust, heating is stopped, and oxidation and reduction are performed by the spontaneous combustion of the raw material mixture to obtain the primitive product. The nitrogen atmosphere continues to flow steadily during the oxidation and reduction reaction, and the primitive product is taken out after the environmental temperature has cooled to room temperature. In the polishing step S21, the primitive product is polished to obtain the polished product. In the first pickling and drying step S3, the polished product is pickled with 35% by mass hydrochloric acid to obtain the first pickled product, the first pickled product is washed with deionized water to neutrality, and the first pickled product is dried at 105°C until the next day to obtain the dried product. In the heat treatment step S4, the dried product is placed in a crucible, a stable nitrogen atmosphere is introduced (nitrogen flow rate: 5542 SCCM) to create a low-oxygen atmosphere, and the dried product is heated and fired for 2 hours at the heat treatment temperature of 800°C to remove residual volatile components of the dried product to obtain the volatile component-removed product. In the second pickling and drying step S5, the volatile component-removed product is pickled with 35% by mass hydrochloric acid to obtain the second pickled product, the second pickled product is washed with deionized water to neutrality, and the second pickled product is dried at 105°C until the next day to form the second pickled product into a porous biochar material. The weight of the obtained porous biochar material was 2.42 g, and the surface area measured by BET was 1599.41 m 2 / g.

[0036] EMBODIMENT 4

[0037] In the material preparation step S1, the biomass carbon source is glucose, the oxidizing agent is potassium nitrate, and 129.58 g of the raw material mixture is obtained by stirring 50% by mass of glucose and 50% by mass of potassium nitrate at 230°C. In the cooling and fixing step S11, the raw material mixture is put into a quartz tube and cooled and fixed to obtain the cooled and fixed raw material mixture. In the oxidation and reduction step S2, a stable nitrogen atmosphere is introduced (nitrogen flow rate: 653 Standard Cubic Centimeters per Minute (SCCM)) to create a low-oxygen atmosphere, the cooled and fixed raw material mixture is heated and spontaneously combusted in the low-oxygen atmosphere, and when the raw material mixture begins to spontaneously combust, heating is stopped, and oxidation and reduction are performed by the spontaneous combustion of the raw material mixture to obtain the primitive product. The nitrogen atmosphere continues to flow steadily during the oxidation and reduction reaction, and the primitive product is taken out after the environmental temperature has cooled to room temperature. In the polishing step S21, the primitive product is polished to obtain the polished product. In the first pickling and drying step S3, the polished product is pickled with 35% by mass hydrochloric acid to obtain the first pickled product, the first pickled product is washed with deionized water to neutrality, and the first pickled product is dried at 105°C until the next day to obtain the dried product. In the heat treatment step S4, the dried product is placed in a crucible, a stable nitrogen atmosphere is introduced (nitrogen flow rate: 5542 SCCM) to create a low-oxygen atmosphere, and the dried product is heated and fired for 2 hours at the heat treatment temperature of 800°C to remove residual volatile components of the dried product to obtain the volatile component-removed product. In the second pickling and drying step S5, the volatile component-removed product is pickled with 35% by mass hydrochloric acid to obtain the second pickled product, the second pickled product is washed with deionized water to neutrality, and the second pickled product is dried at 105°C until the next day to form the second pickled product into a porous biochar material. The weight of the obtained porous biochar material was 1.62 g, and the surface area measured by BET was 2124.05 m 2 / g.

[0038] In detail, the above embodiment utilizes the high oxygen content of the biocarbon source and the oxidizing agent (e.g., potassium nitrate) and the property of spontaneously oxidizing and activating the carbon material at high temperature, and in the process of producing the porous biochar material, the surface area of ​​the product (i.e., the porous biochar material of the present invention) can be easily adjusted by adjusting the ratio of the oxidizing agent. The conventional process of producing high surface area carbon material includes multiple heating and cooling steps and requires the use of expensive and complicated activation techniques. Therefore, compared with the conventional process of producing high surface area carbon material, the method of producing the porous biochar material of the present invention is obviously simple.

[0039] The technical means adopted in the method for producing porous biochar material of the present invention not only simplify the production process, but also produce porous biochar material with high surface area, which has a faster mass transfer rate than conventional activated carbon and can be processed into electrodes for supercapacitors or lithium ion capacitors, thus increasing the economic value of the product.

[0040] Although the preferred embodiments of the present invention have been disclosed as above, they are by no means intended to limit the present invention. Various changes and modifications can be made within the scope of the present invention. Therefore, the claims of the present invention should be broadly interpreted to include such changes and modifications. [Explanation of symbols]

[0041] S1 Material preparation process S11 Cooling and fixing process S2 Oxidation-reduction process S21 Polishing process S3 First pickling and drying process S4 Heat treatment process S5 Second pickling drying process

Claims

1. a material preparation step in which a biomass carbon source, which is glucose or lignin, and an oxidizing agent, which is potassium nitrate or ammonium nitrate, are mixed uniformly at a mixing temperature to obtain a raw material mixture; an oxidation-reduction step in which the raw material mixture is heated and spontaneously combusted under a low-oxygen condition to oxidize and reduce the raw material mixture to obtain a primitive product; a first pickling and drying step of pickling the raw product with an acid to obtain a first pickled product, washing the first pickled product with deionized water to neutrality and drying the first pickled product to obtain a dried product; a heat treatment step of heating the dried product at a heat treatment temperature in a low-oxygen state to remove volatile components remaining in the dried product, thereby obtaining a volatile component-removed product; a second pickling and drying step of pickling the volatile component removal product with an acid to obtain a second pickled product, and washing the second pickled product with deionized water to neutrality and drying the product to obtain a porous biochar material; A method for producing a porous biochar material, comprising:

2. 2. The method according to claim 1, further comprising a cooling and fixing step between the material preparation step and the oxidation and reduction step, of obtaining the cooled and fixed raw material mixture by putting the raw material mixture into a quartz tube and cooling and fixing the raw material mixture, and in the oxidation and reduction step, the cooled and fixed raw material mixture is oxidized and reduced to obtain the initial product.

3. 2. The manufacturing method according to claim 1, characterized in that a polishing process is further included between the oxidation-reduction process and the pickling and drying process, in which the raw product is polished to obtain a polished product, and in the first pickling and drying process, the polished product is pickled to obtain the first pickling product, and the first pickling and drying process results in the dried product.

4. 2. The method according to claim 1, wherein in the material preparation step, the biomass carbon source and the oxidant are evenly mixed by directly mixing the powders or by a solvent-assisted method to obtain the raw material mixture, and the solvent used in the solvent-assisted method is water or alcohol.

5. 2. The method according to claim 1, wherein the raw material mixture contains 10 to 90 mass % of the biomass carbon source and 10 to 90 mass % of the oxidizing agent.

6. 2. The method according to claim 1, wherein the mixing temperature is 200° C. to 400° C. in the material preparation step.

7. 2. The method according to claim 1, wherein the heat treatment temperature is 700° C. to 900° C. in the heat treatment step.

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