High-mesopore and large-porosity activated carbon for waste water and waste gas and preparation method of high-mesopore and large-porosity activated carbon

Abstract

The invention provides activated carbon with high mesopore and macropore ratio for waste water and waste gas, the specific surface area of mesopores is 200-350m < 2 > / g, the ratio of the mesopores is 8-15%, the specific surface area of macropores is 50-100m < 2 > / g, and the ratio of the macropores is 4-8%; the invention also provides a preparation method of the high-mesopore and large-porosity activated carbon for waste water and waste gas. The preparation method sequentially comprises the following steps: carrying out low-temperature primary carbonization; adding asphalt, stirring, grinding and screening; adding an adhesive for kneading; extruding and forming; performing drying; carrying out secondary carbonization; performing screening; activating at high temperature; and screening. The ratio of mesopores and macropores in the total specific surface area is respectively improved, the continuity is strong, the yield is large, no waste product is generated, materials and energy are saved, no chemical process and no environmental pollution are generated, developed mesopores and macropores are provided, larger molecules can be adsorbed, the filtering speed is high, and the method is a better choice for the wastewater and waste gas industry.

Description

Technical Field

[0001] The invention belongs to the technical field of preparation of activated carbon adsorption materials, and in particular relates to activated carbon with high medium pores and macroporosity for waste water and waste gas and a preparation method thereof. Background Art

[0002] The proportions of micropores, mesopores and macropores in activated carbon are as follows: Micropores: The radius of micropores is less than 2nm, and their volume is usually 0.20-0.60cm 3 / g, accounting for more than 95% of the total specific surface area of ​​activated carbon, even exceeding 1500m 2 / g; Mesopore: The radius of the mesopore is between 2 and 50 nm, and its volume is usually between 0.2-0.8 cm 3 / g, with a specific surface area of ​​200-450m 2 / g, mesopores account for a small proportion of the total specific surface area of ​​activated carbon, usually not exceeding 5%; macropores: The radius of macropores is greater than 50nm, and their volume is usually 0.2-0.8cm 3 / g, with the smallest specific surface area, usually between 0.5-100m 2 / g, macropores account for a relatively small proportion of the total specific surface area of ​​activated carbon, usually not exceeding 1%. Application scenarios of different pore sizes: Micropores: Due to their extremely small pore size and huge specific surface area, micropores have a strong adsorption capacity for small molecules, such as hydrogen, carbon dioxide, methane, etc., and are often used in gas storage, indoor air purification, supercapacitor electrode materials and other fields; Mesopores: Mesopores mainly serve as transport channels, helping adsorbate molecules to diffuse into micropores. They are often used to adsorb large molecules or as catalyst carriers, such as adsorbing dye molecules in textile printing and dyeing wastewater treatment; Macropores: Macropores provide channels for adsorbates to enter the interior of activated carbon, and are often used to adsorb large molecules or provide fast adsorption channels. In water treatment, macropores allow large molecular organic matter to quickly enter the interior and then be adsorbed through mesopores and micropores.

[0003] At present, the activated carbon produced contains micropores, mesopores and macropores, and the proportion is unstable. Especially for the activated carbon used in the wastewater and waste gas industries, the adsorption rate of activated carbon per unit mass is only about 15%, and the used activated carbon can only be treated as hazardous waste or solid waste, which greatly wastes resources. At present, the procurement cost of conventional activated carbon is high, the adsorption rate is low, the activated carbon products are frequently replaced, and they cannot be regenerated online, which seriously wastes resources and easily pollutes the environment.

[0004] At present, the mesopores and macropores in conventional activated carbon account for about 5% of the total specific surface area of ​​the activated carbon. It is a waste to use this conventional activated carbon in wastewater and exhaust gas. Summary of the invention

[0005] The purpose of the present invention is to provide an activated carbon with high medium pore size and macropore rate for wastewater and waste gas and a preparation method thereof, which can be used in the field of wastewater adsorption and waste gas adsorption to solve the problems of low adsorption rate of activated carbon, short product replacement cycle and inability to regenerate online.

[0006] In order to achieve the above object, the technical solution of the present invention is as follows:

[0007] An activated carbon with high mesopore and macropore ratio for wastewater and waste gas, wherein the mesopore radius of the activated carbon is between 2 and 50 nm, and the specific surface area of ​​the mesopore is between 200 and 350 m 2 / g, mesopores account for 8%-15% of the total specific surface area of ​​activated carbon;

[0008] The radius of the macropore is greater than 50nm, and the specific surface area of ​​the macropore is 50-100m 2 / g, macropores account for 4%-8% of the total specific surface area of ​​activated carbon;

[0009] The radius of the micropore is less than 2nm, and the specific surface area of ​​the micropore is 1000-1500m 2 / g, and the proportion of micropores in the total specific surface area of ​​activated carbon is the balance.

[0010] A method for preparing high-medium pore and macroporous activated carbon for wastewater and waste gas, comprising the following steps in sequence:

[0011] 1) First, the raw materials are transported to an internal heating carbonization furnace for low-temperature primary carbonization. After the carbonization material is discharged, it is indirectly cooled by water to obtain a primary carbonized material;

[0012] 2) The primary carbonized material and asphalt are stirred and mixed evenly in a stirring tank, and then transported to a grinding machine for grinding to 200 meshes, and after passing through a 200-mesh sieve, the carbonized material undersize is obtained;

[0013] 3) putting the carbonized material under the sieve into a kneader, adding a binder, and mixing to obtain a kneaded material;

[0014] 4) conveying the kneaded material to a press for extrusion molding;

[0015] 5) The molding material then falls onto a steel belt dryer for drying, and after continuous drying is completed, the dried material is obtained;

[0016] 6) The dried material is transported to an externally heated carbonization furnace for secondary carbonization;

[0017] 7) After the secondary carbonization is cooled, the material under the screen is returned to the kneading process, and the material on the screen is the secondary carbonization material;

[0018] 8) The secondary carbonized material is transported to an external heating activation furnace for high temperature activation;

[0019] 9) The activated material is then screened, the material on the screen is columnar activated carbon, and the material under the screen is ground to obtain powdered activated carbon.

[0020] Preferably, in step 1), the raw material is at least one of fruit shell, coconut shell and palm shell.

[0021] Preferably, the primary carbonization temperature is 630°C-670°C, the primary carbonization time is 0.3-1 hour, the oxygen concentration in the rotary carbonization furnace is less than 5% by volume, and the rotary carbonization furnace operates at a slight negative pressure, which is controlled between -50Pa and -100Pa.

[0022] Preferably, the particle size of the asphalt is 80-90 mesh, and the mass of the primary carbonized material: the mass of the asphalt = (75-80): (20-25).

[0023] Preferably, the added mass of the binder accounts for 8%-10% of the mass of the carbonized material underscreen;

[0024] The adhesive is prepared by a mixture of 100 wt% pregelatinized starch and 8 wt% polyacrylamide with a molecular weight of 10 million;

[0025] Kneading is mixing into a paste.

[0026] Preferably, after extrusion molding, the product is cylindrical with a diameter of 3mm-6mm.

[0027] Preferably, the drying condition is 110° C.-130° C., the drying time is 1-2 hours, and the drying is performed to a moisture content of 4wt%-6wt%.

[0028] Preferably, the temperature of the secondary carbonization is 600°C-650°C, the time of the secondary carbonization is 0.4-0.5 hours, the oxygen concentration in the rotary carbonization furnace is less than 5%, and the rotary carbonization furnace operates at a slight negative pressure, and the negative pressure is controlled between -50Pa and -100Pa.

[0029] Preferably, the activation temperature is 800° C.-900° C., the activation time is 30 min-60 min, and water vapor is used as the activating agent for activation.

[0030] This application has achieved the following beneficial technical effects:

[0031] In the present application, the proportion of mesopores and macropores in the activated carbon in the total specific surface area is increased respectively. Using this activated carbon in the wastewater and waste gas industry can increase the adsorption rate of the activated carbon while meeting the use conditions, reduce the number of times the activated carbon is replaced, and save natural resources.

[0032] In the present application, the preparation method: (1) has strong continuity: from raw materials to finished products, advanced devices and equipment are used; (2) has large output: the first carbonization uses an internal heating carbonization furnace, the second carbonization uses an external heating carbonization furnace, and the activation uses an external heating activation furnace. This equipment means large output; (3) no waste products are generated: the secondary carbonization undersize and the activation undersize are both reasonably utilized. The secondary carbonization undersize is returned for kneading, and the activation undersize is ground into another product for application; (4) it saves materials and energy. The advanced method has strong continuity and can save energy; (5) there is no chemical process. At present, there are chemical activation methods such as alkali activation on the market. The preparation of this kind of carbon has certain environmental pollution, and the application range of the produced activated carbon is restricted. This application does not use any chemicals and does not pollute the environment.

[0033] In this application, the main feature of this activated carbon is that although it has only a medium specific surface area, it has well-developed mesopores and macropores, can adsorb larger molecules, and has a fast filtration speed, making it a better choice for use in the wastewater and waste gas industry. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Figure 1 A schematic diagram of the process flow of a method for preparing high-medium pore and macroporous activated carbon for wastewater and waste gas provided in an embodiment of the present application. DETAILED DESCRIPTION

[0035] In order to make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be clearly and completely described below in conjunction with the drawings in the embodiments of the present invention. Obviously, the described embodiments are part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0036] like Figure 1 As shown, the present application provides an activated carbon with high mesopore and macropore ratio for wastewater and waste gas, wherein: the radius of the mesopore is between 2 and 50 nm, and the specific surface area of ​​the mesopore is 200-350 m 2 / g, mesopores account for 8%-15% of the total specific surface area of ​​activated carbon;

[0037] The radius of the macropore is greater than 50nm and less than or equal to 150nm, and the specific surface area of ​​the macropore is 50-100m 2 / g, macropores account for 4%-8% of the total specific surface area of ​​activated carbon;

[0038] The radius of the micropore is less than 2nm and greater than or equal to 0.01nm, and the specific surface area of ​​the micropore is 1000-1500m 2 / g, the proportion of micropores in the total specific surface area of ​​activated carbon is 100% minus the proportion of mesopores and macropores.

[0039] The present application provides a method for preparing high-medium pore and macroporous activated carbon for wastewater and waste gas, comprising the following steps performed in sequence:

[0040] 1) First, the raw materials are transported to an internal heating carbonization furnace for low-temperature primary carbonization. After the carbonization material is discharged, it is indirectly cooled by water to obtain a primary carbonized material;

[0041] 2) The primary carbonized material and asphalt are stirred and mixed evenly in a stirring tank, and then transported to a grinding machine for grinding to 200 meshes, and after passing through a 200-mesh sieve, the carbonized material undersize is obtained;

[0042] 3) putting the carbonized material under the sieve into a kneader, adding a binder, and mixing to obtain a kneaded material;

[0043] 4) conveying the kneaded material to a press for extrusion molding;

[0044] 5) The molding material then falls onto a steel belt dryer for drying, and after continuous drying is completed, the dried material is obtained;

[0045] 6) The dried material is transported to an externally heated carbonization furnace for secondary carbonization;

[0046] 7) After the secondary carbonization is cooled, the material under the screen is returned to the kneading process, and the material on the screen is the secondary carbonization material;

[0047] 8) The secondary carbonized material is transported to an external heating activation furnace for high temperature activation;

[0048] 9) The activated material is then screened, the material on the screen is columnar activated carbon, and the material under the screen is ground to obtain powdered activated carbon.

[0049] In one embodiment of the present application, in step 1), the raw material is at least one of fruit shell, coconut shell and palm shell.

[0050] In one embodiment of the present application, the temperature of a carbonization is 630°C-670°C, the time of a carbonization is 0.3-1 hour, the oxygen concentration in the rotary carbonization furnace is less than 5%, and the rotary carbonization furnace operates at a slightly negative pressure, and the negative pressure is controlled between -50Pa and -100Pa.

[0051] In one embodiment of the present application, the particle size of the asphalt is 80-90 mesh, and the mass of the primary carbonized material: the mass of the asphalt = (75-80): (20-25).

[0052] In one embodiment of the present application, the added mass of the binder accounts for 8%-10% of the mass of the carbonized material underscreen;

[0053] The adhesive is prepared by a mixture of 100 wt% pregelatinized starch and 8 wt% polyacrylamide with a molecular weight of 10 million;

[0054] Kneading is mixing into a paste.

[0055] In one embodiment of the present application, after extrusion molding, the shape is cylindrical with a diameter of 3mm-6mm.

[0056] In one embodiment of the present application, the drying conditions are 110° C.-130° C., the drying time is 1-2 hours, and the drying is performed to a moisture content of 4wt%-6wt%.

[0057] In one embodiment of the present application, the temperature of the secondary carbonization is 600°C-650°C, the time of the secondary carbonization is 0.4-0.5 hours, the oxygen concentration in the rotary carbonization furnace is less than 5%, and the rotary carbonization furnace operates at a slightly negative pressure, and the negative pressure is controlled between -50Pa and -100Pa.

[0058] In one embodiment of the present application, the activation temperature is 800° C.-900° C., the activation time is 30 min-60 min, and water vapor is used as the activating agent for activation.

[0059] The reason why the proportion of mesopores in the activated carbon in the present application in the total specific surface area is increased from no more than 5% to 8%-15% and the reason why the proportion of macropores in the total specific surface area is increased from no more than 1% to 4%-8% is:

[0060] Using water vapor, flue gas (mainly CO 2 ) or its mixed gas or other oxygen-containing gas as an activator, contact with carbon at high temperature to cause redox reaction for activation, generate carbon monoxide, carbon dioxide, hydrogen and other hydrocarbon gases, and achieve the purpose of forming pores in carbon particles through carbon gasification reaction (burning loss). This is also the principle of forming mesopores and macropores. Its main chemical reaction formula is as follows:

[0061] C+2H 2 O=2H 2 +CO 2 ;

[0062] C+H 2 O=H 2 +CO;

[0063] CO 2 +C=2CO;

[0064] The above three chemical reactions are all endothermic reactions, that is, as the activation reaction proceeds, the temperature of the activation reaction area of ​​the activation furnace will gradually decrease. If the temperature of the activation area is lower than 800°C, the above activation reaction cannot proceed normally. Therefore, it is necessary to introduce part of the air into the activation reaction area of ​​the activation furnace to supplement the heat with the gas generated by the activation, or to supplement the external heat source to ensure the activation temperature of the activation reaction area of ​​the activation furnace.

[0065] The activation reaction belongs to multiple reactions of the gas-solid phase system. The activation process includes two processes, physical and chemical. The whole process includes the diffusion of the activator in the gas phase to the outer surface of the carbonized material, the diffusion of the activator to the inner surface of the carbonized material, the adsorption of the activator by the inner and outer surfaces of the carbonized material, the reaction on the surface of the carbonized material to generate intermediate products (surface complexes), the decomposition of intermediate products into reaction products, the desorption of reaction products, and the diffusion of the desorbed reaction products from the inner surface of the carbonized material to the outer surface.

[0066] The activation reaction ultimately achieves the purpose of activation and pore formation through the following three stages:

[0067] 1. The opening of the pores formed during carbonization but blocked by disordered carbon atoms and heteroatoms, that is, at high temperature, the activated gas first reacts with the disordered carbon atoms and heteroatoms;

[0068] 2. The opened pores continue to expand, penetrate and develop in depth. The carbon atoms at the edge of the pores are unsaturated and easily react with the activated gas, thus causing the pores to continue to expand and develop in depth.

[0069] 3. The formation of new pores. As the activation reaction continues, new unsaturated carbon atoms or active points are exposed on the surface of the carbonized material. These new active points can then react with other molecules of the activated gas. This uneven combustion on the surface of the carbonized material continuously leads to the formation of new pores.

[0070] The reason and working principle of adding asphalt in this application:

[0071] Providing carbon source: After high-temperature carbonization, the carbon element in the asphalt forms the basic skeleton of activated carbon, which provides a solid foundation for the subsequent activation process. This skeleton structure not only ensures the stability and mechanical strength of the activated carbon, but also provides it with abundant adsorption sites, enabling the activated carbon to efficiently adsorb various harmful substances;

[0072] Binder: Asphalt plays the role of a binder in the preparation process of activated carbon. Certain components in asphalt can form bonding bridges at high temperatures, bonding the activated carbon particles together to form a block or granular product with a certain mechanical strength. This bonding effect not only improves the molding of activated carbon, but also enhances its durability and stability in practical applications;

[0073] Pore ​​formation and pore structure adjustment: The gas and tar produced during the pyrolysis of asphalt will form new pores, thereby increasing the specific surface area of ​​activated carbon. By controlling the amount of asphalt added and the pyrolysis conditions, the pore structure and distribution of activated carbon can be finely adjusted to optimize its adsorption and catalytic properties.

[0074] Improve mechanical strength and thermal stability: Asphalt can form a strong bonding bridge at high temperature, making the connection between activated carbon particles tighter, thereby improving its compression and wear resistance. In addition, some components in asphalt have high thermal stability and can maintain their basic physical and chemical properties within a certain temperature range, thus extending the service life of activated carbon.

[0075] In this application, primary carbonization and secondary carbonization are performed:

[0076] The purpose of primary carbonization is to pyrolyze the non-carbon components and impurities in the raw materials (such as moisture, impurities) to obtain carbonized materials with higher carbon content. The raw materials include fruit shells, coconut shells, etc.

[0077] The purpose of secondary carbonization is that after the first carbonization, many other auxiliary materials, such as asphalt, are added to the product during the granulation process, and these asphalt and other auxiliary materials all need to be carbonized;

[0078] The difference between the two carbonizations is that the first carbonization is for raw materials, and the second carbonization is for auxiliary materials.

[0079] In the present application, kneading means mixing, that is, uniformly mixing the raw materials and auxiliary materials.

[0080] In this application, extrusion molding is to increase the strength of activated carbon after molding, and the normal extrusion pressure is maintained at 200-240kg / cm 2 .

[0081] In the present application, drying is to dry out the moisture in time so that the formed activated carbon will have sufficient strength.

[0082] In the present application, activation is the reaction of water vapor with carbonized material at high temperature to generate gases such as hydrogen and carbon monoxide. The escape of these gases promotes the expansion and connection of pores inside the carbonized material, forming a rich macroporous and mesoporous structure.

[0083] The methods and devices not described in detail in the present invention are all prior art and will not be described in detail.

[0084] In order to better understand the present invention, the present invention is further specifically described below through the following examples, but it should not be understood as a limitation of the present invention. Some non-essential improvements and adjustments made by technicians in this field based on the above invention content are also considered to fall within the protection scope of the present invention.

[0085] Example 1

[0086] An activated carbon with high mesopore and macroporosity for wastewater and waste gas according to Example 1, wherein: the radius of the mesopore is between 2 and 50 nm, the specific surface area of ​​the mesopore is 205 m2, and the mesopore accounts for 11.75% of the total specific surface area of ​​the activated carbon;

[0087] The radius of the macropore is greater than 50nm, and the specific surface area of ​​the macropore is 90m 2 / g, and the macropores account for 5.16% of the total specific surface area of ​​activated carbon;

[0088] The radius of the micropore is less than 2nm, and the specific surface area of ​​the micropore is 1450m 2 / g, and the proportion of micropores in the total specific surface area of ​​activated carbon is the balance.

[0089] A method for preparing high-medium pore and macroporous activated carbon for wastewater and waste gas in Example 1 comprises the following steps performed in sequence:

[0090] 1) First, the raw materials are transported to an internal heating carbonization furnace for low-temperature primary carbonization. After the carbonization material is discharged, it is indirectly cooled by water to obtain a primary carbonized material;

[0091] 2) The primary carbonized material and asphalt are stirred and mixed evenly in a stirring tank, and then transported to a grinding machine for grinding to 200 meshes, and after passing through a 200-mesh sieve, the carbonized material undersize is obtained;

[0092] 3) putting the carbonized material under the sieve into a kneader, adding a binder, and mixing to obtain a kneaded material;

[0093] 4) conveying the kneaded material to a press for extrusion molding;

[0094] 5) The molding material then falls onto a steel belt dryer for drying, and after continuous drying is completed, the dried material is obtained;

[0095] 6) The dried material is transported to an externally heated carbonization furnace for secondary carbonization;

[0096] 7) After the secondary carbonization is cooled, the material under the screen is returned to the kneading process, and the material on the screen is the secondary carbonization material;

[0097] 8) The secondary carbonized material is transported to an external heating activation furnace for high temperature activation;

[0098] 9) The activated material is then screened, the material on the screen is columnar activated carbon, and the material under the screen is ground to obtain powdered activated carbon;

[0099] In step 1), the raw material is at least one of fruit shell, coconut shell and palm shell;

[0100] The primary carbonization temperature is 650°C, the primary carbonization time is 0.4 hours, the oxygen concentration in the rotary carbonization furnace is less than 5%, and the rotary carbonization furnace operates at a slight negative pressure, which is controlled between -50Pa and -80Pa;

[0101] The particle size of asphalt is 80 mesh, the mass of primary carbonized material: the mass of asphalt = 78:22;

[0102] The added mass of the binder accounts for 9% of the mass of the carbonized material under the sieve;

[0103] The adhesive is prepared by a mixture of 100 wt% pregelatinized starch and 8 wt% polyacrylamide with a molecular weight of 10 million;

[0104] Kneading is mixing into a paste;

[0105] After extrusion, it is cylindrical with a diameter of 4mm;

[0106] The drying condition is 115°C, the drying time is 1.5 hours, and the drying is performed until the water content is 5wt%;

[0107] The temperature of the secondary carbonization is 625°C, the time of the secondary carbonization is 0.4 hours, the oxygen concentration in the rotary carbonization furnace is less than 5%, and the rotary carbonization furnace operates at a slight negative pressure, which is controlled between -50Pa and -80Pa;

[0108] The activation temperature is 835°C-845°C, the activation time is 40 minutes, and water vapor is used as the activating agent.

[0109] Example 2

[0110] Example 2 is an activated carbon with high mesopore and macropore ratio for wastewater and waste gas, wherein the mesopore radius of the activated carbon is between 2 and 50 nm, and the specific surface area of ​​the mesopore is 213 m 2 / g, mesopores account for 11.85% of the total specific surface area of ​​activated carbon;

[0111] The radius of the macropore is greater than 50nm, and the specific surface area of ​​the macropore is 85m 2 / g, macropores account for 4.73% of the total specific surface area of ​​activated carbon;

[0112] The radius of the micropore is less than 2nm, and the specific surface area of ​​the micropore is 1500m 2 / g, and the proportion of micropores in the total specific surface area of ​​activated carbon is the balance.

[0113] A method for preparing high-medium pore and macroporous activated carbon for wastewater and waste gas in Example 2 comprises the following steps performed in sequence:

[0114] 1) First, the raw materials are transported to an internal heating carbonization furnace for low-temperature primary carbonization. After the carbonization material is discharged, it is indirectly cooled by water to obtain a primary carbonized material;

[0115] 2) The primary carbonized material and asphalt are stirred and mixed evenly in a stirring tank, and then transported to a grinding machine for grinding to 200 meshes, and after passing through a 200-mesh sieve, the carbonized material undersize is obtained;

[0116] 3) putting the carbonized material under the sieve into a kneader, adding a binder, and mixing to obtain a kneaded material;

[0117] 4) conveying the kneaded material to a press for extrusion molding;

[0118] 5) The molding material then falls onto a steel belt dryer for drying, and after continuous drying is completed, the dried material is obtained;

[0119] 6) The dried material is transported to an externally heated carbonization furnace for secondary carbonization;

[0120] 7) After the secondary carbonization is cooled, the material under the screen is returned to the kneading process, and the material on the screen is the secondary carbonization material;

[0121] 8) The secondary carbonized material is transported to an external heating activation furnace for high temperature activation;

[0122] 9) The activated material is then screened, the material on the screen is columnar activated carbon, and the material under the screen is ground to obtain powdered activated carbon;

[0123] In step 1), the raw material is at least one of fruit shell, coconut shell and palm shell;

[0124] The temperature of the first carbonization is 640°C, the time of the first carbonization is 0.5 hours, the oxygen concentration in the rotary carbonization furnace is less than 5%, and the rotary carbonization furnace operates at a slight negative pressure, which is controlled between -50Pa and -80Pa;

[0125] The particle size of asphalt is 80 mesh, the mass of primary carbonized material: the mass of asphalt = 80:20;

[0126] The added mass of the binder accounts for 8% of the mass of the carbonized material under the sieve;

[0127] The adhesive is prepared by a mixture of 100 wt% pregelatinized starch and 8 wt% polyacrylamide with a molecular weight of 10 million;

[0128] Kneading is mixing into a paste;

[0129] After extrusion, it is cylindrical with a diameter of 4mm;

[0130] The drying condition is 120°C, the drying time is 1.6 hours, and the drying is performed to a water content of 5.6 wt%;

[0131] The temperature of the secondary carbonization is 630°C, the time of the secondary carbonization is 0.4 hours, the oxygen concentration in the rotary carbonization furnace is less than 5%, and the rotary carbonization furnace operates at a slight negative pressure, which is controlled between -50Pa and -80Pa;

[0132] The activation temperature is 840°C-850°C, the activation time is 45 minutes, and water vapor is used as the activating agent.

[0133] Example 3

[0134] Example 3 is an activated carbon with high mesopore and macropore ratio for wastewater and waste gas, wherein the radius of the mesopore is between 2 and 50 nm, and the specific surface area of ​​the mesopore is 225 m 2 / g, mesopores account for 13.08% of the total specific surface area of ​​activated carbon;

[0135] The radius of the macropore is greater than 50nm, and the specific surface area of ​​the macropore is 95m 2 / g, and the macropores account for 5.52% of the total specific surface area of ​​activated carbon;

[0136] The radius of the micropore is less than 2nm, and the specific surface area of ​​the micropore is 1400m 2 / g, and the proportion of micropores in the total specific surface area of ​​activated carbon is the balance.

[0137] A method for preparing high-medium pore and macroporous activated carbon for wastewater and waste gas in Example 3 comprises the following steps performed in sequence:

[0138] 1) First, the raw materials are transported to an internal heating carbonization furnace for low-temperature primary carbonization. After the carbonization material is discharged, it is indirectly cooled by water to obtain a primary carbonized material;

[0139] 2) The primary carbonized material and asphalt are stirred and mixed evenly in a stirring tank, and then transported to a grinding machine for grinding to 200 meshes, and after passing through a 200-mesh sieve, the carbonized material undersize is obtained;

[0140] 3) putting the carbonized material under the sieve into a kneader, adding a binder, and mixing to obtain a kneaded material;

[0141] 4) conveying the kneaded material to a press for extrusion molding;

[0142] 5) The molding material then falls onto a steel belt dryer for drying, and after continuous drying is completed, the dried material is obtained;

[0143] 6) The dried material is transported to an externally heated carbonization furnace for secondary carbonization;

[0144] 7) After the secondary carbonization is cooled, the material under the screen is returned to the kneading process, and the material on the screen is the secondary carbonization material;

[0145] 8) The secondary carbonized material is transported to an external heating activation furnace for high temperature activation;

[0146] 9) The activated material is then screened, the material on the screen is columnar activated carbon, and the material under the screen is ground to obtain powdered activated carbon;

[0147] In step 1), the raw material is at least one of fruit shell, coconut shell and palm shell;

[0148] The primary carbonization temperature is 655°C, the primary carbonization time is 0.35 hours, the oxygen concentration in the rotary carbonization furnace is less than 5%, and the rotary carbonization furnace operates at a slight negative pressure, which is controlled between -50Pa and -80Pa;

[0149] The particle size of asphalt is 80 mesh, the mass of primary carbonized material: the mass of asphalt = 75:25;

[0150] The added mass of the binder accounts for 9.5% of the mass of the carbonized material under the sieve;

[0151] The adhesive is prepared by a mixture of 100 wt% pregelatinized starch and 8 wt% polyacrylamide with a molecular weight of 10 million;

[0152] Kneading is mixing into a paste;

[0153] After extrusion, it is cylindrical with a diameter of 4mm;

[0154] The drying condition is 118°C, the drying time is 1.4 hours, and the drying is performed to a water content of 5.2 wt%;

[0155] The temperature of the secondary carbonization is 635°C, the time of the secondary carbonization is 0.42 hours, the oxygen concentration in the rotary carbonization furnace is less than 5%, and the rotary carbonization furnace operates at a slight negative pressure, and the negative pressure is controlled between -50Pa and -80Pa;

[0156] The activation temperature is 840°C-845°C, the activation time is 35 minutes, and water vapor is used as the activating agent.

[0157] The above description of the disclosed embodiments enables one skilled in the art to implement or use the present invention. Various modifications to these embodiments will be apparent to one skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to the embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An activated carbon with high medium pore size and high porosity for wastewater and waste gas, characterized in that: In the activated carbon, the radius of the mesopore is between 2 and 50 nm, and the specific surface area of ​​the mesopore is 200-350 m 2 / g, mesopores account for 8%-15% of the total specific surface area of ​​activated carbon; The radius of the macropore is greater than 50nm, and the specific surface area of ​​the macropore is 50-100m 2 / g, macropores account for 4%-8% of the total specific surface area of ​​activated carbon; The radius of the micropore is less than 2nm, and the specific surface area of ​​the micropore is 1000-1500m 2 / g, and the proportion of micropores in the total specific surface area of ​​activated carbon is the balance.

2. A method for preparing high-medium pore and macroporous activated carbon for wastewater and waste gas, characterized in that: The method includes the following steps in sequence: 1) First, the raw materials are transported to an internal heating carbonization furnace for low-temperature primary carbonization. After the carbonization material is discharged, it is indirectly cooled by water to obtain a primary carbonized material; 2) The primary carbonized material and asphalt are stirred and mixed evenly in a stirring tank, and then transported to a grinding machine for grinding to 200 meshes, and after passing through a 200-mesh sieve, the carbonized material undersize is obtained; 3) putting the carbonized material under the sieve into a kneader, adding a binder, and mixing to obtain a kneaded material; 4) conveying the kneaded material to a press for extrusion molding; 5) The molding material then falls onto a steel belt dryer for drying, and after continuous drying is completed, the dried material is obtained; 6) The dried material is transported to an externally heated carbonization furnace for secondary carbonization; 7) After the secondary carbonization is cooled, the material under the screen is returned to the kneading process, and the material on the screen is the secondary carbonization material; 8) The secondary carbonized material is transported to an external heating activation furnace for high temperature activation; 9) The activated material is then screened, the material on the screen is columnar activated carbon, and the material under the screen is ground to obtain powdered activated carbon.

3. The method for preparing high-medium pore and macroporous activated carbon for wastewater and waste gas according to claim 2, characterized in that: In step 1), the raw material is at least one of fruit shell, coconut shell and palm shell.

4. The method for preparing high-medium pore and macroporous activated carbon for wastewater and waste gas according to claim 2, characterized in that: The primary carbonization temperature is 630°C-670°C, the primary carbonization time is 0.3-1 hour, the oxygen concentration in the rotary carbonization furnace is less than 5% by volume, and the rotary carbonization furnace operates at a slight negative pressure, which is controlled between -50Pa and -100Pa.

5. The method for preparing high-medium pore and macroporous activated carbon for wastewater and waste gas according to claim 2, characterized in that: The particle size of asphalt is 80-90 mesh, and the mass of primary carbonized material: the mass of asphalt = (75-80): (20-25).

6. The method for preparing high-medium pore and macroporous activated carbon for wastewater and waste gas according to claim 2, characterized in that: The added mass of the binder accounts for 8%-10% of the mass of the carbonized material under the sieve; The adhesive is prepared by a mixture of 100 wt% pregelatinized starch and 8 wt% polyacrylamide with a molecular weight of 10 million; Kneading is mixing into a paste.

7. The method for preparing high-medium pore and macroporous activated carbon for wastewater and waste gas according to claim 2, characterized in that: After extrusion molding, it is cylindrical with a diameter of 3mm-6mm.

8. The method for preparing high-medium pore and macroporous activated carbon for wastewater and waste gas according to claim 2, characterized in that: The drying conditions are 110° C.-130° C., the drying time is 1-2 hours, and the drying is performed until the moisture content is 4wt%-6wt%.

9. The method for preparing high-medium pore and macroporous activated carbon for wastewater and waste gas according to claim 2, characterized in that: The temperature of the secondary carbonization is 600°C-650°C, the time of the secondary carbonization is 0.4-0.5 hours, the oxygen concentration in the rotary carbonization furnace is less than 5%, and the rotary carbonization furnace operates at a slight negative pressure, and the negative pressure is controlled between -50Pa and -100Pa.

10. The method for preparing high-medium pore and macroporous activated carbon for wastewater and waste gas according to claim 2, characterized in that: The activation temperature is 800°C-900°C, the activation time is 30min-60min, and water vapor is used as the activating agent.

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