Activated carbon with high meso-macropore ratio for wastewater and exhaust gas and preparation method thereof

Abstract

The application provides a high-middle-large-pore ratio activated carbon for waste water and waste gas, the specific surface area of the middle pore is 200-350 m 2 / g, the middle pore ratio is 8%-15%, the specific surface area of the large pore is 50-100 m 2 / g, and the large pore ratio is 4%-8%; the application also provides a preparation method of the high-middle-large-pore ratio activated carbon for waste water and waste gas, which comprises the following steps in sequence: low-temperature primary carbonization; adding pitch, stirring and grinding, and screening; adding a binder and kneading; extrusion molding; drying; secondary carbonization; screening; high-temperature activation; and screening. The middle pore ratio and the large pore ratio in the total specific surface area are both increased, the continuity is strong, the yield is large, no waste product is generated, materials and energy are saved, no chemical process is needed, no environmental pollution is caused, the developed middle pore and large pore can adsorb larger molecules, the filtration speed is fast, and the activated carbon is a better choice for the waste water and waste gas industry.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of activated carbon adsorption material preparation, and particularly relates to an activated carbon with high and medium pore and macropore rate for waste water and waste gas and a preparation method thereof. BACKGROUND

[0002] The proportions of micropores, mesopores and macropores in the activated carbon are as follows: micropores: the radius of the micropores is less than 2nm, the volume thereof is usually 0.20-0.60cm 3 / g, and more than 95% of the total specific surface area of the activated carbon, even more than 1500m 2 / g; mesopores: the radius of the mesopores is between 2 and 50nm, the volume thereof is usually 0.2-0.8cm 3 / g, and the specific surface area thereof is 200-450m 2 / g, the mesopores account for less than 5% of the total specific surface area of the activated carbon; macropores: the radius of the macropores is greater than 50nm, the volume thereof is usually 0.2-0.8cm 3 / g, and the specific surface area thereof is the smallest, usually 0.5-100m 2 / g, and the macropores account for less than 1% of the total specific surface area of the activated carbon. Application scenarios of different pore diameters: micropores: due to the extremely small pore diameter and the huge specific surface area, the micropores have extremely strong adsorption capacity for small molecule substances such as hydrogen, carbon dioxide and methane, and they are often used in the fields of gas storage, indoor air purification, super capacitor electrode materials and the like; mesopores: the mesopores mainly serve as transport channels to help the diffusion of adsorbate molecules into micropores, and they are often used to adsorb large molecule substances or as catalyst carriers, for example, to adsorb dye molecules in textile printing and dyeing wastewater treatment; macropores: the macropores provide channels for adsorbates to enter the interior of the activated carbon, and they are often used to adsorb large molecule substances or to provide fast adsorption channels, in water treatment, the macropores can enable large molecule organic substances to quickly enter the interior, and then be adsorbed by the mesopores and micropores.

[0003] At present, the activated carbon produced contains micropores, mesopores and macropores, and the proportions are unstable, especially the activated carbon used in the wastewater and waste gas industry, the adsorption rate of the 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 the conventional activated carbon is high, the adsorption rate is low, the activated carbon product needs to be replaced frequently, cannot be regenerated online, resources are wasted seriously, and the environment is easily polluted.

[0004] At present, the mesopores and macropores in the conventional activated carbon account for about 5% of the total specific surface area of the activated carbon, and it is very wasteful to use the conventional activated carbon in waste water and waste gas. SUMMARY

[0005] The application aims to provide a high-middle-large-pore activated carbon for waste water and waste gas and a preparation method thereof.

[0006] In order to achieve the above-mentioned purpose, the technical scheme of the application is as follows:

[0007] A high-middle-large-pore activated carbon for waste water and waste gas, wherein the radius of the middle pore is between 2 and 50 nm, the specific surface area of the middle pore is 200-350 m 2 / g, and the middle pore accounts for 8%-15% in the total specific surface area of the activated carbon.

[0008] The radius of the large pore is greater than 50 nm, the specific surface area of the large pore is 50-100 m 2 / g, and the large pore accounts for 4%-8% in the total specific surface area of the activated carbon.

[0009] The radius of the micro-pore is less than 2 nm, the specific surface area of the micro-pore is 1000-1500 m 2 / g, and the micro-pore accounts for the balance in the total specific surface area of the activated carbon.

[0010] A preparation method of the high-middle-large-pore activated carbon for waste water and waste gas, comprising the following steps in sequence:

[0011] 1) Firstly, the raw material is delivered to an internal heat type carbonization furnace for low-temperature primary carbonization, and after the carbonization is discharged, the carbonization material is indirectly cooled by water to obtain a primary carbonization material;

[0012] 2) The primary carbonization material is uniformly mixed with pitch in a stirring tank, and then is delivered to a powder mill for grinding to 200 mesh, and after passing through a 200 mesh sieve, a carbonization material undersize is obtained;

[0013] 3) The carbonization material undersize is put into a kneader and a binder is added for mixing to obtain a kneaded material;

[0014] 4) The kneaded material is delivered to a press for extrusion molding;

[0015] 5) Then the molded material falls onto a steel belt dryer for drying, and after continuous drying, a dried material is obtained;

[0016] 6) The dried material is delivered to an external heat type carbonization furnace for secondary carbonization;

[0017] 7) After the secondary carbonization is cooled, screening is performed, the undersize is returned to the kneading process, and the oversize is a secondary carbonization material;

[0018] 8) The secondary carbonization material is delivered to an external heat type activation furnace for high-temperature activation;

[0019] 9) Then the activated material is screened, the sieve residue is columnar activated carbon, and the sieve residue 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 temperature of the first carbonization is 630-670 DEG C, the time of the first carbonization is 0.3-1 hour, the oxygen concentration in the rotary carbonization furnace is less than 5% by volume, and the rotary carbonization furnace is operated under micro-negative pressure, with the negative pressure controlled between -50 Pa and -100 Pa.

[0022] Preferably, the particle size of the pitch is 80-90 mesh, and the mass ratio of the first carbonization material to the pitch is (75-80):(20-25).

[0023] Preferably, the added mass of the binder accounts for 8-10% of the mass of the carbonization material sieve residue.

[0024] The binder is prepared by mixing 100 wt% of pregelatinized starch with 8 wt% of 10 million molecular weight polyacrylamide.

[0025] The kneading is mixed into a paste.

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

[0027] Preferably, the drying condition is 110-130 DEG C, the drying time is 1-2 hours, and the drying is performed until the water content is 4-6 wt%.

[0028] Preferably, the temperature of the second carbonization is 600-650 DEG C, the time of the second carbonization is 0.4-0.5 hour, the oxygen concentration in the rotary carbonization furnace is less than 5%, and the rotary carbonization furnace is operated under micro-negative pressure, with the negative pressure controlled between -50 Pa and -100 Pa.

[0029] Preferably, the activation temperature is 800-900 DEG C, the activation time is 30-60 min, and the activation is performed by using water vapor as the activator.

[0030] The present application has the following beneficial technical effects:

[0031] In the present application, the proportion of mesopores and macropores in the total specific surface area of the activated carbon is increased respectively, and the activated carbon is used in the wastewater and waste gas industry, which can increase the use adsorption rate of the activated carbon, reduce the replacement frequency of the activated carbon, and save natural resources under the premise of meeting the use conditions.

[0032] In the present application, the preparation method has the following advantages: (1) strong continuity: from raw materials to finished products, advanced devices and equipment are used; (2) large yield: the inner heating type carbonization furnace is selected for the first carbonization, the outer heating type carbonization furnace is selected for the second carbonization, and the outer heating type activation furnace is selected for the activation, which means that the yield is large; (3) no waste product is generated: the second carbonization screen underflow and the activation screen underflow are reasonably utilized, the second carbonization screen underflow returns to kneading, and the activation screen underflow is ground into another application product; (4) saving of materials and energy, advanced method and strong continuity can save energy; (5) no chemical process, the chemical activation process exists in the market, which has certain environmental pollution and restricts the application range of the activated carbon, and the present application does not use chemicals and has no environmental pollution.

[0033] In the present application, the activated carbon mainly has the following characteristics: although the specific surface area is only moderate, the developed mesopores and macropores can adsorb large molecules, the filtration speed is fast, and the activated carbon is a better choice for the wastewater and waste gas industry. BRIEF DESCRIPTION OF DRAWINGS

[0034] Figure 1 A process flow diagram of a preparation method of a high-mesopore and macropore rate activated carbon for wastewater and waste gas is provided for the embodiments of the present application. DETAILED DESCRIPTION

[0035] To make the purpose, technical scheme and advantages of the embodiments of the present application clearer, the technical scheme in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of protection of the present application.

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

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

[0038] The radius of the micropores is less than 2 nm and greater than or equal to 0.01 nm, the specific surface area of the micropores is 1000-1500 m 2micropore in the total specific surface area of the activated carbon.

[0039] The application provides a preparation method of activated carbon with high mesopore and macropore ratio for waste water and waste gas, comprising the following steps in sequence:

[0040] 1) first, the raw material is transported into an internal heating carbonization furnace for low-temperature primary carbonization, and after the carbonization is discharged, the carbonization material is indirectly cooled by water to obtain a primary carbonization material;

[0041] 2) the primary carbonization material is uniformly mixed with pitch in a stirring tank, and then is transported into a grinding machine for grinding to 200 mesh, and after passing through a 200-mesh sieve, a carbonization material undersize is obtained;

[0042] 3) the carbonization material undersize is put into a kneader, and an adhesive is added for mixing to obtain a kneaded material;

[0043] 4) the kneaded material is transported into a press for extrusion molding;

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

[0045] 6) the dried material is transported into an external heating carbonization furnace for secondary carbonization;

[0046] 7) after secondary carbonization and cooling, screening is performed, the undersize is returned to the kneading process, and the oversize is a secondary carbonization material;

[0047] 8) the secondary carbonization material is transported into an external heating activation furnace for high-temperature activation;

[0048] 9) then, the activated material is screened again, the oversize is a columnar activated carbon, and the undersize is ground to obtain a powdery activated carbon.

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

[0050] In an embodiment of the application, the temperature of primary carbonization is 630-670 DEG C, the time of primary carbonization is 0.3-1 hour, the oxygen concentration in the rotary carbonization furnace is less than 5%, and the rotary carbonization furnace is operated under micro-negative pressure, and the negative pressure is controlled to be between-50 Pa and-100 Pa.

[0051] In an embodiment of the application, the particle size of the pitch is 80-90 mesh, and the mass ratio of the primary carbonization material to the pitch is (75-80):(20-25).

[0052] In an embodiment of the application, the added mass of the adhesive accounts for 8-10% of the mass of the carbonization material undersize.

[0053] The method for preparing the adhesive is mixing 100 wt% of the pregelatinized starch with 8 wt% of 10 million molecular weight polyacrylamide;

[0054] The kneading is mixed into a paste.

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

[0056] In an embodiment of the present application, the drying condition is 110-130°C, the drying time is 1-2 hours, and the drying is performed until the water content is 4-6 wt%.

[0057] In an embodiment of the present application, the temperature for the secondary carbonization is 600-650°C, the time for 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 is operated under a micro-negative pressure with the negative pressure controlled between -50 Pa and -100 Pa.

[0058] In an embodiment of the present application, the activation temperature is 800-900°C, the activation time is 30-60 min, and the activation is performed by using steam as the activator.

[0059] The reason why the proportion of the mesopores in the total specific surface area of the activated carbon in the present application is increased from not more than 5% to 8-15% and the reason why the proportion of the macropores in the total specific surface area is increased from not more than 1% to 4-8% are as follows:

[0060] The oxygen-containing gas such as steam, flue gas (main component: CO2) or mixed gas thereof is used as the activator, and the oxidation-reduction reaction is performed at a high temperature to generate carbon monoxide, carbon dioxide, hydrogen and other hydrocarbon gases, and the gasification reaction (loss on ignition) of carbon is performed to form pores in the carbon particles, which is also the principle for forming mesopores and macropores. The main chemical reaction formulae are as follows:

[0061] C + 2H2O = 2H2 + CO2;

[0062] C + H2O = H2 + CO;

[0063] CO2 + C = 2CO;

[0064] The above three chemical reactions are endothermic reactions, that is, the temperature of the activation reaction zone of the activation furnace will gradually decrease with the progress of the activation reaction. If the temperature of the activation zone is lower than 800°C, the above activation reaction cannot be normally performed. Therefore, part of the air and the coal gas generated by the activation are simultaneously introduced into the activation reaction zone of the activation furnace to combust and supplement the heat, or an external heat source is added to ensure the activation temperature of the activation reaction zone of the activation furnace.

[0065] The activation reaction belongs to a plurality of reactions of a gas-solid phase system. The activation process includes physical and chemical processes. The whole process includes diffusion of the activation agent in the gas phase to the outer surface of the carbonized material, diffusion of the activation agent to the inner surface of the carbonized material, adsorption of the activation agent by the inner and outer surfaces of the carbonized material, reaction of the surface of the carbonized material to generate an intermediate product (a surface complex), decomposition of the intermediate product into a reaction product, desorption of the reaction product, diffusion of the desorbed reaction product from the inner surface to the outer surface of the carbonized material, and the like;

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

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

[0068] 2. The opened pores are continuously expanded, connected and developed in depth. The carbon atoms at the edges of the pores have an unsaturated structure and are easy to react with the activation gas, thereby causing the pores to continuously expand and develop in depth;

[0069] 3. Formation of new pores. With the continuous activation reaction, 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 activation gas, and the non-uniform combustion on the surface of the carbonized material continuously leads to the formation of new pores.

[0070] Reasons and working principles of adding pitch in the present application:

[0071] Providing a carbon source: After carbonization at high temperature, the carbon elements in pitch form the basic framework of activated carbon, providing a solid foundation for the subsequent activation process. This framework structure not only ensures the stability and mechanical strength of activated carbon, but also provides abundant adsorption sites, enabling activated carbon to efficiently adsorb various harmful substances;

[0072] Binder: Pitch plays the role of a binder in the preparation of activated carbon. Certain components in pitch can form a binding bridge at high temperatures, binding activated carbon particles together to form blocky or granular products with certain mechanical strength. This binding effect not only improves the formability of activated carbon, but also enhances its durability and stability in actual applications;

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

[0074] Improve mechanical strength and thermal stability: asphalt can form a strong cohesive bridge at high temperature, so that the connection between activated carbon particles is more closely, thereby improving its compression and wear resistance, in addition, some components in asphalt also have high thermal stability, can maintain its basic physical and chemical properties within a certain temperature range, prolong the service life of activated carbon.

[0075] The primary carbonization and secondary carbonization in the application are:

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

[0077] The purpose of secondary carbonization is that after the first carbonization, a lot of other auxiliary materials, such as asphalt, are added in the granulation process, and these asphalt and other auxiliary materials need to be carbonized.

[0078] The difference between the two carbonizations is that the primary carbonization is for the raw material, and the secondary carbonization is for the auxiliary material.

[0079] In the application, kneading is mixing, which is to uniformly mix the raw material and auxiliary material.

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

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

[0082] In the application, activation is the reaction of water vapor with carbonized material at high temperature to generate hydrogen and carbon monoxide, etc. The escape of these gases promotes the expansion and connection of the internal pores of the carbonized material, forming abundant large and medium pore structures.

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

[0084] In order to better understand the application, the following examples are used to further specifically illustrate the application, but it should not be understood as limiting the application. Some non-essential improvements and adjustments made by those skilled in the art according to the above application content are also regarded as falling within the protection scope of the application.

[0085] Example 1

[0086] The activated carbon for wastewater and waste gas in Example 1 has a high medium and large pore rate, wherein the radius of the medium pores is between 2 and 50 nm, the specific surface area of the medium pores is 205 m2, and the medium pores account for 11.75% of the total specific surface area of the activated carbon.

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

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

[0089] The preparation method of the activated carbon with high mesopore and macropore rates for wastewater and waste gas in Example 1 comprises the following steps performed in sequence:

[0090] 1) First, the raw material is fed into an internal heat type carbonization furnace for low-temperature primary carbonization, and after the carbonization is discharged, it is indirectly cooled by water to obtain a primary carbonization material;

[0091] 2) The primary carbonization material is uniformly mixed with pitch in a stirring tank, and then fed into a powder mill for grinding to 200 mesh, and after passing through a 200 mesh sieve, a carbonization material undersize is obtained;

[0092] 3) The carbonization material undersize is put into a kneader and an adhesive is added for mixing to obtain a kneaded material;

[0093] 4) The kneaded material is fed into a press for extrusion molding;

[0094] 5) Then the molded material falls onto a steel belt dryer for drying, and after continuous drying, a dried material is obtained;

[0095] 6) The dried material is fed into an external heat type carbonization furnace for secondary carbonization;

[0096] 7) After secondary carbonization cooling, screening is performed, the undersize is returned to the kneading process, and the oversize is a secondary carbonization material;

[0097] 8) The secondary carbonization material is fed into an external heat type activation furnace for high-temperature activation;

[0098] 9) Then the activated material is screened again, the oversize is a columnar activated carbon, and the undersize is ground to obtain a powdered activated carbon;

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

[0100] The temperature of the primary carbonization is 650°C, the time of the primary carbonization is 0.4 hours, the oxygen concentration in the rotary carbonization furnace is less than 5%, and the rotary carbonization furnace is operated under micro-negative pressure, with the negative pressure controlled between -50 Pa and -80 Pa;

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

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

[0103] The method of making the binder is a mixture of 100wt% pregelatinized starch and 8wt% 10 million molecular weight polyacrylamide;

[0104] The kneading is mixed into a paste;

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

[0106] The drying conditions are 115℃, the drying time is 1.5 hours, and the drying is carried out to a water content of 5wt%;

[0107] The temperature of the secondary carbonization is 625℃, 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 is operated under micro-negative pressure, with the negative pressure controlled between-50Pa and-80Pa;

[0108] The activation temperature is 835℃-845℃, the activation time is 40min, and the activation is carried out using water vapor as the activator.

[0109] Example 2

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

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

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

[0113] The method for preparing the activated carbon for wastewater and waste gas in Example 2 includes the following steps performed in sequence:

[0114] 1) First, the raw materials are transported into an internal heat type carbonization furnace for low temperature primary carbonization, and after the carbonized material is discharged, it is indirectly cooled by water to obtain a primary carbonized material;

[0115] 2) The primary carbonized material is mixed and stirred uniformly with pitch in a stirring tank, and then transported into a flour mill for grinding to 200 mesh, and after passing through a 200 mesh sieve, a carbonized material undersize is obtained;

[0116] 3) The carbonized material is put into a kneader and mixed with a binder to obtain a kneaded material;

[0117] 4) The kneaded material is fed into a press to be extruded;

[0118] 5) The extruded material is then dried on a steel belt dryer to obtain dried material;

[0119] 6) The dried material is fed into an external heating carbonization furnace for secondary carbonization;

[0120] 7) The secondary carbonized material is sieved after cooling, and the undersize material is returned to the kneading process, and the oversize material is the secondary carbonized material;

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

[0122] 9) The activated material is then sieved, and the oversize material is columnar activated carbon, and the undersize material is ground to obtain powdered activated carbon;

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

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

[0125] The particle size of the pitch is 80 mesh, and the mass ratio of the primary carbonized material to the pitch is 80:20;

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

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

[0128] The kneading is mixed into a paste;

[0129] The extruded shape is cylindrical, with a diameter of 4 mm;

[0130] The drying conditions are 120°C, and the drying time is 1.6 hours, with the moisture content being 5.6 wt% after drying;

[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 is operated under a slight negative pressure, with the negative pressure controlled between -50 Pa and -80 Pa;

[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: An activated carbon with high mesopore and macroporous rate 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 225 m 2 / g, mesopores account for 13.08% of the total specific surface area of ​​activated carbon;

[0135] The radius of the macropores is greater than 50nm, and the specific surface area of ​​the macropores 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] The method for preparing high-medium pore and macroporous activated carbon for wastewater and waste gas of 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 discharge, the material is indirectly cooled with water to obtain a primary carbonized material;

[0139] 2) The primary carbonized material and asphalt are stirred and mixed uniformly in a mixing tank, and then transported to a grinding mill for grinding to 200 mesh, and passed through a 200 mesh sieve to obtain the carbonized material undersize;

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

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

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

[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 screening is carried out, the under-screen material returns to the kneading process, and the over-screen material is the secondary carbonized material;

[0145] 8) Transporting the secondary carbonized material to an external heating activation furnace for high-temperature activation;

[0146] 9) The activated material is then sieved, the sieve-surface material is columnar activated carbon, and the sieve-underface material is ground into powdered activated carbon;

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

[0148] The temperature of the primary carbonization is 655°C, the time of the primary carbonization is 0.35 hours, the oxygen concentration in the rotary carbonization furnace is less than 5%, and the rotary carbonization furnace is operated under micro-negative pressure, with the negative pressure controlled between -50 Pa and -80 Pa;

[0149] The particle size of the pitch is 80 mesh, and the mass ratio of the primary carbonization material to the pitch is 75:25;

[0150] The added mass of the binder accounts for 9.5% of the mass of the carbonization material undersize;

[0151] The binder is made of a mixture of 100 wt% of pregelatinized starch and 8 wt% of 100 million molecular weight polyacrylamide;

[0152] The kneading is mixed into a paste;

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

[0154] The drying condition is 118°C, the drying time is 1.4 hours, and the drying is performed until the water content is 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 is operated under micro-negative pressure, with the negative pressure controlled between -50 Pa and -80 Pa;

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

[0157] The above description of disclosed embodiments enables one skilled in the art to make or use the application. Numerous modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be applied to other embodiments without departing from the spirit or scope of the application. Therefore, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A high meso-macropore ratio activated carbon for waste water exhaust gas, characterized by, The mesopore radius is between 2 and 50 nm, the specific surface area of the mesopore is 200-350 m² / g, and the mesopore accounts for 8%-15% of the total specific surface area of the activated carbon. The macropore radius is greater than 50 nm, the specific surface area of the macropore is 50-100 m² / g, and the macropore accounts for 4%-8% of the total specific surface area of the activated carbon. The micropore radius is less than 2 nm, the specific surface area of the micropore is 1000-1500 m² / g, and the micropore accounts for the balance of the total specific surface area of the activated carbon.

2. A method for producing activated carbon having a high mesopore and macropore ratio for waste water and exhaust gas, for producing the activated carbon having a high mesopore and macropore ratio for waste water and exhaust gas according to claim 1, characterized by, It comprises the following steps in turn: 1) First, the raw material is transported to the internal heat type carbonization furnace for low temperature primary carbonization, and after the carbonization discharge is indirectly cooled by water, the primary carbonized material is obtained; 2) The primary carbonized material is mixed with pitch in a stirring tank, then transported to a flour mill for grinding, and ground to 200 mesh, after passing through a 200 mesh screen, the carbonized material undersize is obtained; 3) The carbonized material undersize is put into a kneader and an adhesive is added for mixing to obtain a kneaded material; 4) The kneaded material is transported to a press for extrusion molding; 5) Then the molded material falls onto a steel belt dryer for drying, and after continuous drying, the dried material is obtained; 6) The dried material is transported to an external heat type carbonization furnace for secondary carbonization; 7) After secondary carbonization cooling, screening is performed, the undersize is returned to the kneading process, and the oversize is the secondary carbonized material; 8) The secondary carbonized material is transported to an external heat type activation furnace for high temperature activation; 9) Then the activated material is screened again, the oversize is columnar activated carbon, and the undersize is powdered activated carbon after grinding.

3. The method of claim 2, wherein the activated carbon has a high mesopore rate. In step 1), the raw material is at least one of fruit shells, coconut shells, and palm shells.

4. The method of claim 2, wherein the activated carbon has a high mesopore and macropore ratio. The temperature of primary carbonization is 630-670℃, the time of primary carbonization 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 under micro negative pressure, with the negative pressure controlled between-50Pa and-100Pa.

5. The preparation method of the activated carbon with high mesopore and macropore rate for wastewater and waste gas according to claim 2, characterized in that the particle size of the pitch is 80-90 mesh, and the mass ratio of the primary carbonized material to the pitch is (75-80):(20-25).

6. The method of claim 2, wherein the activated carbon has a high mesopore and macropore ratio. The added mass of the adhesive accounts for 8%-10% of the mass of the carbonized material undersize; The adhesive is made by adding 8% by weight of 100 million molecular weight polyacrylamide to 100% by weight of pregelatinized starch; Kneading is mixing into a paste.

7. The method of claim 2, wherein the activated carbon has a high mesopore and macropore ratio. After extrusion molding, it is cylindrical with a diameter of 3-6 mm.

8. The method of claim 2, wherein the activated carbon has a high mesopore and macropore ratio. The drying conditions are 110-130℃, and the drying time is 1-2 hours, and the moisture content is 4-6wt% after drying.

9. The method of claim 2, wherein the activated carbon has a high mesopore and macropore ratio. The temperature of secondary carbonization is 600-650℃, the time of secondary carbonization is 0.4-0.5 hour, the oxygen concentration in the rotary carbonization furnace is less than 5%, and the rotary carbonization furnace operates under micro negative pressure, with the negative pressure controlled between-50Pa and-100Pa.

10. The method of claim 2, wherein the activated carbon has a high mesopore and macropore ratio. The activation temperature is 800-900 DEG C, the activation time is 30-60 minutes, and water vapor is used as the activation agent.

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