Method for preparing activated carbon in pressurized atmosphere

Abstract

The invention provides a method for preparing activated carbon in a pressurized atmosphere, which comprises the following steps: 1) performing pyrolysis carbonization treatment on a biomass material in a protective gas atmosphere to obtain biomass charcoal; and 2) activating the biomass charcoal in a pressurized gas atmosphere to obtain the activated carbon material. According to the method, the active carbon material with large specific surface area, high microporosity, high product quality and high monomer price can be prepared.

Description

Technical Field

[0001] The invention relates to the technical field of activated carbon preparation, in particular to a method for preparing activated carbon under a pressurized atmosphere. Background Art

[0002] Activated carbon is a functional material with well-developed pores, large specific surface area, and strong adsorption capacity. It has stable physical and chemical properties, is resistant to acid, alkali, and heat, and can be regenerated after failure. Activated carbon materials have been widely used in food, medicine, water treatment, gas purification and recovery, chemical industry, environmental protection, metallurgy, national defense, agriculture and other fields.

[0003] As a large agricultural country, my country has a growing proportion of crop straw, fruit shells and other wastes year by year. However, most agricultural wastes have not been used as resources (such as burning, landfilling, and random discarding), which has aggravated the pollution and destruction of the agricultural ecological environment and caused serious waste of resources. In traditional production methods, the raw materials for the production of activated carbon are often non-renewable resources such as coal, lignite, and petroleum residues, or expensive wood.

[0004] However, due to the continuous shortage of energy and the continuous reduction of forest area, a new solution of utilizing renewable resources is urgently needed. Summary of the invention

[0005] The present invention aims to solve one of the technical problems in the related art at least to a certain extent. To this end, one purpose of the present invention is to propose a method for producing activated carbon using renewable resources (mainly biomass) as an effective solution. This method uses agricultural and forestry waste as raw materials, which can not only reduce costs, but also make resource utilization of agricultural and forestry waste, while also avoiding environmental pollution problems caused by unorganized incineration. The inventor has developed and designed a new method for preparing activated carbon materials from biomass with large specific surface area, high microporosity, high product quality and high monomer price.

[0006] In a first aspect of the present invention, the present invention provides a method for preparing an activated carbon material under a pressurized atmosphere. According to an embodiment of the present invention, the method comprises:

[0007] 1) In an atmosphere of protective gas, the biomass material is subjected to pyrolysis and carbonization treatment to obtain biomass charcoal;

[0008] 2) Activating the biochar in a pressurized gas atmosphere to obtain an activated carbon material. The method is simple to operate and environmentally friendly. In addition, the method according to the embodiment of the present invention can obtain an activated carbon material with a large specific surface area, high microporosity, high product quality, and high monomer price.

[0009] According to an embodiment of the present invention, the above method may further include at least one of the following additional technical features:

[0010] According to an embodiment of the present invention, the biomass material is one or more of mushroom sticks, bamboo, pine, straw, bagasse, wheat straw and pine sawdust. The method uses agricultural and forestry waste as raw materials, which can not only reduce costs, but also make use of agricultural and forestry waste as resources, while also avoiding environmental pollution caused by unorganized incineration.

[0011] According to an embodiment of the present invention, the biomass material is pre-grinded and screened.

[0012] According to an embodiment of the present invention, the grinding and screening processes are performed by placing the dried biomass raw material into a grinding and milling machine for grinding and screening until the biomass raw material is ground into powder and then screened.

[0013] According to an embodiment of the present invention, the sieving process uses a sieve mesh size of 40-1000 mesh, such as 40 mesh, 100 mesh, 200 mesh, 300 mesh, 400 mesh, 500 mesh, 600 mesh, 700 mesh, 800 mesh, 900 mesh, or 1000 mesh.

[0014] According to an embodiment of the present invention, the temperature of the pyrolysis carbonization treatment is 500-800°C, such as 500°C, 600°C, 700°C or 800°C.

[0015] According to an embodiment of the present invention, the time of the pyrolysis carbonization treatment is 10-120 min, for example, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min, 90 min, 100 min, 110 min, or 120 min, etc.

[0016] According to an embodiment of the present invention, the protective gas is one or more selected from nitrogen, argon and helium.

[0017] According to an embodiment of the present invention, the temperature of the activation treatment is 500-1200°C, for example, 500°C, 600°C, 700°C, 800°C, 900°C, 1000°C, 1100°C, or 1200°C.

[0018] According to an embodiment of the present invention, the activation treatment time is 10-120 min, for example, 10 min, 20 min, 30 min, 40 min, 50 min, 60 min, 70 min, 80 min, 90 min, 100 min, 110 min, or 120 min.

[0019] According to an embodiment of the present invention, the pressurized gas is selected from one or more of carbon dioxide, water vapor, air, oxygen, and flue gas.

[0020] According to an embodiment of the present invention, the heating rate in the pyrolysis carbonization treatment process is 1 to 20°C / min, for example, 1°C / min, 2°C / min, 3°C / min, 4°C / min, 5°C / min, 6°C / min, 7°C / min, 8°C / min, 9°C / min, 10°C / min, 11°C / min, 12°C / min, 13°C / min, 14°C / min, 15°C / min, 16°C / min, 17°C / min, 18°C / min, 19°C / min, or 20°C / min.

[0021] According to an embodiment of the present invention, the cooling rate during the pyrolysis carbonization treatment is 3 to 15°C / min, for example, 3°C / min, 4°C / min, 5°C / min, 6°C / min, 7°C / min, 8°C / min, 9°C / min, 10°C / min, 11°C / min, 12°C / min, 13°C / min, 14°C / min or 15°C / min.

[0022] According to an embodiment of the present invention, the heating rate in the activation treatment process is 1 to 20°C / min, for example, 1°C / min, 2°C / min, 3°C / min, 4°C / min, 5°C / min, 6°C / min, 7°C / min, 8°C / min, 9°C / min, 10°C / min, 11°C / min, 12°C / min, 13°C / min, 14°C / min, 15°C / min, 16°C / min, 17°C / min, 18°C / min, 19°C / min, or 20°C / min.

[0023] According to an embodiment of the present invention, the cooling rate during the activation treatment is 3 to 15°C / min, for example, 3°C / min, 4°C / min, 5°C / min, 6°C / min, 7°C / min, 8°C / min, 9°C / min, 10°C / min, 11°C / min, 12°C / min, 13°C / min, 14°C / min or 15°C / min.

[0024] According to an embodiment of the present invention, the gas flow rate in the activation treatment process is controlled at 10mL / min-500mL / min, for example, 10mL / min, 50mL / min, 100mL / min, 150mL / min, 200mL / min, 250mL / min, 300mL / min, 350mL / min, 400mL / min, 450mL / min, or 500mL / min.

[0025] According to an embodiment of the present invention, the pressure during the activation treatment is 0.1013MPa-10Mpa, for example, 0.2MPa, 0.3MPa, 0.4MPa, 0.5MPa, 0.6MPa, 0.7MPa, 0.8MPa, 0.9MPa, 1MPa, 2MPa, 3MPa, 4MPa, 5MPa, 6MPa, 7MPa, 8MPa, 9MPa, or 10MPa.

[0026] In another aspect of the present invention, the present invention further provides an activated carbon material. According to an embodiment of the present invention, the activated carbon material is prepared by the method described above.

[0027] In another aspect of the present invention, the present invention also proposes the application of the above-mentioned method in treating agricultural and forestry wastes.

[0028] According to the embodiments of the present invention, compared with the traditional method for preparing activated carbon from biomass, the present invention has at least one of the following technical effects:

[0029] (1) The present invention provides a method for preparing activated carbon materials under a pressurized atmosphere, wherein the biomass is first carbonized under a protective atmosphere, and then the biomass charcoal is activated under a pressurized atmosphere; the preparation method has a simple process and high possibility of large-scale production, which can solve the problem that traditional preparation methods cannot be prepared on a large scale.

[0030] (2) The present invention provides an activated carbon material prepared under a pressurized atmosphere, which is prepared by the above-mentioned preparation method. In view of the advantages of the above-mentioned preparation method, the activated carbon material prepared under a pressurized atmosphere is characterized by BET, and it can be seen that the material has high microporosity and high specific surface area, which indicates that pressurization during the activation process can have a beneficial effect on the pore-forming process of activated carbon.

[0031] The present invention also provides an application of the activated carbon material prepared under the above-mentioned pressurized atmosphere. In view of the advantages of the above-mentioned preparation method, the activated carbon material prepared under the pressurized atmosphere can be analyzed by analyzing its preparation cost to find that the quality of the activated carbon material is high, which increases the monomer price of the activated carbon material, thereby bringing a significant increase in income and achieving further high-value conversion, which broadens the application scenarios of the activated carbon material. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] The above and / or additional aspects and advantages of the present invention will become apparent and easily understood from the description of the embodiments in conjunction with the following drawings, in which:

[0033] Figure 1 2 is a graph of specific surface areas of the embodiments and comparative examples;

[0034] Figure 2is a microporosity relationship diagram of the embodiment and the comparative example;

[0035] Figure 3 It is the relationship diagram of iodine value between the embodiment and the comparative example. DETAILED DESCRIPTION

[0036] The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present invention, but should not be construed as limiting the present invention.

[0037] Example 1

[0038] This embodiment provides a method for preparing activated carbon material from biomass in a pressurized atmosphere, comprising the following steps:

[0039] (1) The dried mushroom stick raw material is placed in a crushing and grinding machine for crushing and grinding until the biomass activated carbon raw material is crushed into powder and screened, and the screening mesh size is 100 mesh.

[0040] (2) The screened raw materials are placed in a tubular furnace for carbonization. The tubular furnace is a nitrogen gas environment with a gas flow rate of 80 mL / min, a carbonization temperature of 700 °C, and the temperature is maintained for 60 min to obtain biochar.

[0041] (3) The obtained biomass activated carbon was activated. The atmosphere in the tubular furnace was CO2, 1 MPa, the gas flow rate was controlled at 100 mL / min, the activation temperature was 800°C, and the temperature was maintained for 30 min to obtain activated carbon material.

[0042] Example 2

[0043] This embodiment provides a method for preparing activated carbon material from biomass in a pressurized atmosphere, comprising the following steps:

[0044] (1) The dried mushroom stick raw material is placed in a crushing and grinding machine for crushing and grinding until the biomass activated carbon raw material is crushed into powder and screened, and the screening mesh size is 100 mesh.

[0045] (2) The screened raw materials are placed in a tubular furnace for carbonization. The tubular furnace is a nitrogen gas environment with a gas flow rate of 80 mL / min, a carbonization temperature of 700 °C, and the temperature is maintained for 60 min to obtain biochar.

[0046] (3) The obtained biomass activated carbon was activated. The atmosphere in the tubular furnace was CO2, 2MPa, the gas flow rate was controlled at 100mL / min, the activation temperature was 800°C, and the temperature was maintained for 30min to obtain activated carbon material.

[0047] Example 3

[0048] This embodiment provides a method for preparing activated carbon material from biomass in a pressurized atmosphere, comprising the following steps:

[0049] (1) The dried Si Ya pine raw material is placed in a crushing and grinding machine for crushing and grinding until the biomass activated carbon raw material is crushed into powder and screened, and the screening mesh size is 100 mesh.

[0050] (2) The screened raw materials are placed in a tubular furnace for carbonization. The tubular furnace is a nitrogen gas environment with a gas flow rate of 80 mL / min, a carbonization temperature of 700 °C, and the temperature is maintained for 60 min to obtain biochar.

[0051] (3) The obtained biomass activated carbon was activated. The atmosphere in the tubular furnace was CO2, 1 MPa, the gas flow rate was controlled at 100 mL / min, the activation temperature was 800°C, and the temperature was maintained for 30 min to obtain activated carbon material.

[0052] Example 4

[0053] This embodiment provides a method for preparing activated carbon material from biomass in a pressurized atmosphere, comprising the following steps:

[0054] (1) The dried Si Ya pine raw material is placed in a crushing and grinding machine for crushing and grinding until the biomass activated carbon raw material is crushed into powder and screened, and the screening mesh size is 100 mesh.

[0055] (2) The screened raw materials are placed in a tubular furnace for carbonization. The tubular furnace is a nitrogen gas environment with a gas flow rate of 80 mL / min, a carbonization temperature of 700 °C, and the temperature is maintained for 60 min to obtain biochar.

[0056] (3) The obtained biomass activated carbon was activated. The atmosphere in the tubular furnace was CO2, 2MPa, the gas flow rate was controlled at 100mL / min, the activation temperature was 800°C, and the temperature was maintained for 30min to obtain activated carbon material.

[0057] Example 5

[0058] This embodiment provides a method for preparing activated carbon material from biomass in a pressurized atmosphere, comprising the following steps:

[0059] (1) The dried rice straw raw material is placed in a grinding and grinding machine for grinding and grinding until the biomass activated carbon raw material is ground into powder and screened, and the screening mesh size is 100 mesh.

[0060] (2) The screened raw materials are placed in a tubular furnace for carbonization. The tubular furnace is a nitrogen gas environment with a gas flow rate of 80 mL / min, a carbonization temperature of 700 °C, and the temperature is maintained for 60 min to obtain biochar.

[0061] (3) The obtained biomass activated carbon was activated. The atmosphere in the tubular furnace was CO2, 1 MPa, the gas flow rate was controlled at 100 mL / min, the activation temperature was 800°C, and the temperature was maintained for 30 min to obtain activated carbon material.

[0062] Example 6

[0063] This embodiment provides a method for preparing activated carbon material from biomass in a pressurized atmosphere, comprising the following steps:

[0064] (1) The dried rice straw raw material is placed in a grinding and grinding machine for grinding and grinding until the biomass activated carbon raw material is ground into powder and screened, and the screening mesh size is 100 mesh.

[0065] (2) The screened raw materials are placed in a tubular furnace for carbonization. The tubular furnace is a nitrogen gas environment with a gas flow rate of 80 mL / min, a carbonization temperature of 700 °C, and the temperature is maintained for 60 min to obtain biochar.

[0066] (3) The obtained biomass activated carbon was activated. The atmosphere in the tubular furnace was CO2, 2MPa, the gas flow rate was controlled at 100mL / min, the activation temperature was 800°C, and the temperature was maintained for 30min to obtain activated carbon material.

[0067] Example 7

[0068] This embodiment provides a method for preparing activated carbon material from biomass in a pressurized atmosphere, comprising the following steps:

[0069] (1) The dried bamboo raw material is placed in a crushing and grinding machine for crushing and grinding until the biomass activated carbon raw material is crushed into powder and screened, and the screening mesh size is 100 mesh.

[0070] (2) The screened raw materials are placed in a tubular furnace for carbonization. The tubular furnace is a nitrogen gas environment with a gas flow rate of 80 mL / min, a carbonization temperature of 700 °C, and the temperature is maintained for 60 min to obtain biochar.

[0071] (3) The obtained biomass activated carbon was activated. The atmosphere in the tubular furnace was CO2, 1 MPa, the gas flow rate was controlled at 100 mL / min, the activation temperature was 800°C, and the temperature was maintained for 30 min to obtain activated carbon material.

[0072] Example 8

[0073] This embodiment provides a method for preparing activated carbon material from biomass in a pressurized atmosphere, comprising the following steps:

[0074] (1) The dried bamboo raw material is placed in a crushing and grinding machine for crushing and grinding until the biomass activated carbon raw material is crushed into powder and screened, and the screening mesh size is 100 mesh.

[0075] (2) The screened raw materials are placed in a tubular furnace for carbonization. The tubular furnace is a nitrogen gas environment with a gas flow rate of 80 mL / min, a carbonization temperature of 700 °C, and the temperature is maintained for 60 min to obtain biochar.

[0076] (3) The obtained biomass activated carbon was activated. The atmosphere in the tubular furnace was CO2, 2MPa, the gas flow rate was controlled at 100mL / min, the activation temperature was 800°C, and the temperature was maintained for 30min to obtain activated carbon material.

[0077] Comparative Example 1

[0078] This embodiment provides a method for preparing activated carbon material from biomass in a pressurized atmosphere, comprising the following steps:

[0079] (1) The dried mushroom stick raw material is placed in a crushing and grinding machine for crushing and grinding until the biomass activated carbon raw material is crushed into powder and screened, and the screening mesh size is 100 mesh.

[0080] (2) The screened raw materials are placed in a tubular furnace for carbonization. The tubular furnace is a nitrogen gas environment with a gas flow rate of 80 mL / min, a carbonization temperature of 700 °C, and the temperature is maintained for 60 min to obtain biochar.

[0081] (3) Activating the biomass activated carbon, the atmosphere in the tubular furnace is CO2, normal pressure, the gas flow rate is controlled at 100 mL / min, the activation temperature is 800°C, the temperature is maintained for 30 min, and the activated carbon material is obtained.

[0082] Comparative Example 2

[0083] This embodiment provides a method for preparing activated carbon material from biomass in a pressurized atmosphere, comprising the following steps:

[0084] (1) The dried Si Ya pine raw material is placed in a crushing and grinding machine for crushing and grinding until the biomass activated carbon raw material is crushed into powder and screened, and the screening mesh size is 100 mesh.

[0085] (2) The screened raw materials are placed in a tubular furnace for carbonization. The tubular furnace is a nitrogen gas environment with a gas flow rate of 80 mL / min, a carbonization temperature of 700 °C, and the temperature is maintained for 60 min to obtain biochar.

[0086] (3) Activating the biomass activated carbon, the atmosphere in the tubular furnace is CO2, normal pressure, the gas flow rate is controlled at 100 mL / min, the activation temperature is 800°C, the temperature is maintained for 30 min, and the activated carbon material is obtained.

[0087] Comparative Example 3

[0088] This embodiment provides a method for preparing activated carbon material from biomass in a pressurized atmosphere, comprising the following steps:

[0089] (1) The dried rice straw raw material is placed in a grinding and grinding machine for grinding and grinding until the biomass activated carbon raw material is ground into powder and screened, and the screening mesh size is 100 mesh.

[0090] (2) The screened raw materials are placed in a tubular furnace for carbonization. The tubular furnace is a nitrogen gas environment with a gas flow rate of 80 mL / min, a carbonization temperature of 700 °C, and the temperature is maintained for 60 min to obtain biochar.

[0091] (3) Activating the biomass activated carbon, the atmosphere in the tubular furnace is CO2, normal pressure, the gas flow rate is controlled at 100 mL / min, the activation temperature is 800°C, the temperature is maintained for 30 min, and the activated carbon material is obtained.

[0092] Comparative Example 4

[0093] This embodiment provides a method for preparing activated carbon material from biomass in a pressurized atmosphere, comprising the following steps:

[0094] (1) The dried bamboo raw material is placed in a crushing and grinding machine for crushing and grinding until the biomass activated carbon raw material is crushed into powder and screened, and the screening mesh size is 100 mesh.

[0095] (2) The screened raw materials are placed in a tubular furnace for carbonization. The tubular furnace is a nitrogen gas environment with a gas flow rate of 80 mL / min, a carbonization temperature of 700 °C, and the temperature is maintained for 60 min to obtain biochar.

[0096] (3) Activating the biomass activated carbon, the atmosphere in the tubular furnace is CO2, normal pressure, the gas flow rate is controlled at 100 mL / min, the activation temperature is 800°C, the temperature is maintained for 30 min, and the activated carbon material is obtained.

[0097] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described may be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art may combine and combine the different embodiments or examples described in this specification and the features of the different embodiments or examples, without contradiction.

[0098] Although the embodiments of the present invention have been shown and described above, it is to be understood that the above embodiments are exemplary and are not to be construed as limitations of the present invention. A person skilled in the art may change, modify, replace and vary the above embodiments within the scope of the present invention.

Claims

1. A method for preparing activated carbon material under pressurized atmosphere, characterized in that: include: 1) In an atmosphere of protective gas, the biomass material is subjected to pyrolysis and carbonization treatment to obtain biomass charcoal; 2) Activating the biomass charcoal in a pressurized gas atmosphere to obtain an activated carbon material.

2. The method according to claim 1, characterized in that The biomass material is one or more of mushroom sticks, bamboo, pine, straw, bagasse, wheat straw and pine sawdust.

3. The method according to claim 1, characterized in that The biomass material is pre-grinded and screened; Optionally, the grinding and screening process is performed by placing the dried biomass raw material into a grinding and milling machine for grinding and screening until the biomass raw material is ground into powder and then screened; Optionally, the screening process uses a sieving mesh size of 40-1000 meshes.

4. The method according to claim 1, characterized in that: The temperature of the pyrolysis carbonization treatment is 500-800°C; Optionally, the pyrolysis carbonization treatment time is 10-120min; Optionally, the protective gas is one or more selected from nitrogen, argon and helium.

5. The method according to claim 1, characterized in that The temperature of the activation treatment is 500-1200°C; Optionally, the activation treatment time is 10-120 min; Optionally, the pressurized gas is selected from one or more of carbon dioxide, water vapor, air, oxygen, and flue gas.

6. The method according to claim 1, characterized in that The heating rate during the pyrolysis carbonization process is 1 to 20°C / min; Optionally, the cooling rate during the pyrolysis carbonization process is 3 to 15° C. / min.

7. The method according to claim 1, characterized in that The heating rate during the activation treatment is 1 to 20°C / min; Optionally, the cooling rate during the activation treatment is 3 to 15°C / min; Optionally, the gas flow rate during the activation treatment is controlled at 10 mL / min-500 mL / min.

8. The method according to claim 1, characterized in that The pressure during the activation treatment is 0.1013MPa-10Mpa.

9. An activated carbon material, characterized in that The activated carbon material is prepared by the method according to any one of claims 1 to 8.

10. Use of the method according to any one of claims 1 to 8 in treating agricultural and forestry wastes.

Images