JPS6132249B2 - - Google Patents

Description

[Detailed description of the invention]

Activated carbon has conventionally been used in powder or granular form as an adsorbent for various substances, as a catalyst carrier, and the like. Powdered activated carbon has excellent adsorption ability, but has the disadvantages of large pressure loss during fluid permeation, poor regeneration efficiency, and difficult handling. On the other hand, although powdered activated carbon is superior to powdered activated carbon in terms of fluid permeability, regeneration efficiency, and ease of handling, it has the disadvantage of inferior adsorption ability, and is also susceptible to vibration during use. Due to rocking or the like, the filled state of the activated carbon becomes uneven in density, creating gaps in some parts through which fluid can easily pass, and the activated carbon cannot be used uniformly and effectively throughout. As a means to improve these drawbacks, fibrous activated carbon obtained by carbonizing and activating insoluble fibers or fibers or fiber structures that have been subjected to insolubilization treatment has been proposed. These materials can be in the form of woven fabrics, non-woven fabrics, etc. and are therefore somewhat superior in handling, but they have drawbacks such as low strength and significantly large pressure loss. In addition, as another method to improve the above-mentioned drawbacks,
Activated carbon obtained by carbonizing and activating organic polymer foams has been proposed, but in many of them, the foams do not have continuous pores, the pore size distribution is not uniform, the porosity is low, and it is difficult to give shape. However, it has drawbacks such as large deformation and weight loss during carbonization activation. The present inventors have developed a new method for producing activated carbon that overcomes the above-mentioned drawbacks by carbonizing and activating a synthetic resin composite porous body with continuous pores made of a polyvinyl acetal-based synthetic resin and a resin that can be converted into glassy carbon by thermal decomposition. We proposed a method for producing network-structured activated carbon. The network activated carbon has excellent adsorption ability, has continuous pores with a uniform pore size distribution, has low pressure loss, does not become denser due to vibration or rocking, and is easy to regenerate. It has certain characteristics. However, the network structure activated carbon also has the disadvantage that the specific surface area cannot be increased beyond a certain level because cracks occur in the activated carbon structure when the activation conditions are tightened to increase the specific surface area and the yield during activation is reduced. This tendency was more pronounced as the size of the activated carbon structure became larger. As a result of intensive research to improve the above-mentioned drawbacks of network-structured activated carbon, the present inventors have discovered a composite porous material with continuous air consisting of a polyvinyl acetal-based synthetic resin, a resin that can be converted into glassy carbon by thermal decomposition, and ceramic fine powder. The present invention was completed based on the discovery that network-structured activated carbon with excellent properties can be obtained by carbonizing and activating the activated carbon. The purpose of the present invention is to provide a method for producing network-structured activated carbon that has continuous pores with a uniform pore size distribution, has low pressure loss during fluid permeation, has good shape retention, and has a large specific surface area and excellent adsorption capacity. It is on offer. The above purpose is to carbonize and activate the resin component in a composite porous body with continuous pores made of polyvinyl acetal synthetic resin, a resin that can be converted into glassy carbon by thermal decomposition, or a resin containing these as the main component, and fine ceramic powder. This is achieved by The manufacturing method of the composite porous body having continuous pores of the present invention can be roughly divided into two. The first method is to first create a polyvinyl acetal synthetic resin porous body with continuous pores containing fine ceramic powder, impregnate the porous body with a resin that can be converted into glassy carbon by thermal decomposition, and then harden it. It's a method. The second method is to mix a phenolic resin, which is one of the resins that can be converted into glassy carbon, with polyvinyl alcohol, fine ceramic powder, and a pore-forming material, and then react and cure the mixture in the presence of a crosslinking agent. In order to produce a polyvinyl acetal-based synthetic resin porous body containing ceramic fine powder in the first method, polyvinyl alcohol and ceramic fine powder are mixed with aldehydes as a crosslinking agent, starch as a pore forming material, and a water-soluble thermoplastic resin. etc. and a catalyst such as sulfuric acid, cross-linked and molded, and after solidification, water-soluble substances are eluted with water to provide continuous pores. The polyvinyl alcohol used in the production of the polyvinyl acetal synthetic resin porous body containing the ceramic fine powder mentioned above has a degree of polymerization of 100 to 5000 and a degree of saponification of 70% or more, and may also be partially modified with carboxyl groups, etc. Suitably used. Ceramic fine powders include oxides such as silica, alumina, aluminum silicate, magnesia, zirconium oxide, zirconium silicate, and titanium oxide, clays such as Kibushi clay, Frogme clay, and clay Shamotsu, kaolin, and diatomaceous earth. , montmorinite, bentonite, silicon carbide, silicon nitride, aluminum phosphate, etc. are suitable, but are not limited to these. These ceramic fine powders may be used alone, or two or more types of fine powders may be used in combination. Among them, fine powders containing acid-soluble alkaline components such as montmolinite and bentonite react with the acid added as a catalyst during the production of the composite porous body.
This is particularly preferred because it forms a strong composite porous body in which fine ceramic powder and synthetic resin are uniformly mixed. Examples of the aldehydes used as crosslinking agents include formaldehyde, acetaldehyde, propionaldehyde, n-butyraldehyde, octylaldehyde, 2-ethylhexylaldehyde, glyoxal, acrolein, and benzaldehyde. As the powder or granule for providing continuous pores, starch or other organic fine powder, water-soluble metal salt, or the like is used, and the powder or granule is appropriately selected so as to provide the desired pore size. A more specific description of the method for producing a ceramic-containing polyvinyl acetal synthetic resin porous body using the above-mentioned polyvinyl alcohol, ceramic fine powder, and pore-forming material is as follows. That is, a predetermined amount of polyvinyl alcohol aqueous solution is heated with stirring, fine ceramic powder previously dispersed in water is added thereto and stirred, and then an aqueous solution or aqueous dispersion of a pore-forming material such as wheat flour starch is added. After cooling to about 40°C, aldehydes as a crosslinking agent and sulfuric acid as a catalyst are added, mixed uniformly, and cast into a mold of the desired shape. This is further heated to cause a reaction, and after the reaction is completed, the molded product taken out from the mold is washed with water to wash away aldehydes and acids that have not reacted with the pore-forming material. The shape of the porous body can be freely selected from plate-like, cylindrical, cylindrical, etc. depending on the purpose, use, and required performance. Among the polyvinyl acetal synthetic resin porous bodies containing fine ceramic powder thus obtained, polyvinyl formal synthetic resin porous bodies having a specific network structure or polyvinyl benzal synthetic resin porous bodies are particularly suitable. Examples of resins that can be converted into glassy carbon to be impregnated into the polyvinyl acetal synthetic resin porous body containing fine ceramic powder produced as described above include phenolic resins such as resol resins and novolac resins, and furan resins. Although these may be used alone or in combination, resol resins are most preferred, and novolac resins are second most preferred, considering workability such as resin curing operations. Resole resin is an initial product produced by reacting phenolic resin with aldehydes in the presence of a basic catalyst, and is a self-thermal crosslinking resol with a molecular weight of up to about 600, usually rich in methylol groups. be. In particular, when producing resol resins, water-soluble resols can be obtained by reacting 1.5 to 3.5 moles of aldehydes with 1 mole of phenol in the presence of a slightly excess alkali catalyst. Phenols used in the production of resol resins most commonly include phenols and cresols. However, other phenols can also be used, such as phenol, 0-cresol, m-cresol, p-cresol, 2,3-xylenol,
2,5-xylenol, 2,4-xylenol,
2,6-xylenol, 3,4-xylenol,
3,5-xylenol, 0-ethylphenol,
m-ethylphenol, p-ethylphenol,
Examples include p-phenylphenol, p-tert-butylphenol, p-tert-aminophenol, bisphenol A, resorcinol, and mixtures of these phenols. Formaldehyde is the most common aldehyde used for polycondensation with this phenol. However, monoaldehydes and dialdehydes such as paraformaldehyde, hexamethylenetetramine, furfural and glutaraldehyde, adipaldehyde and glyoxal may also be used. As the basic catalyst used in the resol resin synthesis reaction, known catalysts such as caustic alkali, alkali carbonate, barium hydroxide, calcium hydroxide, ammonia, quaternary ammonium compounds, and amines may be used. is most commonly used. The novolac resin is prepared by adding the same phenols used in the production of the resol resin and the same aldehydes used in the production of the resol resin to oxalic acid, formic acid, acetic acid, halogenated acid, and p-toluenesulfonic acid. An uncured and meltable compound with a molecular weight of about 300 to 2000, which can be produced by reacting with heating in the presence of an acid catalyst of organic acids such as hydrochloric acid, sulfuric acid, perchloric acid, phosphoric acid, etc., and inorganic acids such as phosphoric acid. It is a thermoplastic resin. Examples of the furan resin include furfuryl alcohol resin, furfuryl alcohol phenol resin, furfural resin, furfural phenol resin, and furfural ketone resin. As a curing agent for these resins, for example, organic acids such as aniline hydrochloride and para-toluenesulfonic acid can be used. Various methods can be applied to produce a composite porous body by applying a resin that can be converted into glassy carbon to a polyvinyl acetal synthetic resin porous body having continuous pores containing the aforementioned fine ceramic powder. However, most commonly, a polyvinyl acetal synthetic resin porous body containing fine ceramic powder having a predetermined shape, pore diameter, and porosity may be immersed in a phenol resin solution, a furan resin solution, or the like. A phenolic resin such as a resol resin or a novolac resin can be dissolved in an appropriate amount in a solvent such as methanol or acetone to prepare a phenolic resin solution with a predetermined concentration. In addition, as a resol resin,
Water-soluble resols can also be used. In the case of a resol resin, if necessary, a small amount of an organic acid such as paratoluenesulfonic acid or phthalic acid may be added in advance to the solution as an acid catalyst for curing. In the case of a novolak resin, a novolak resin solution prepared by dissolving an appropriate amount of a crosslinking agent in a solvent such as methanol or acetone may be used. As a crosslinking agent, hexamethylenetetramine can be used most commonly, but its value also includes paraformaldehyde, glutaraldehyde,
Aldehydes such as adipaldehyde and glyoxal may be used in combination with acids or alkalis. Alternatively, the porous body may be impregnated with the novolac resin in advance and then heated and cured in an aqueous solution containing hexamethylenetetramine, an acid or alkali, and an aldehyde. In the case of a furan resin, a solution may be used in which the furan resin is dissolved in a solvent such as acetone or benzene, and further a curing agent such as aniline hydrochloride or paratoluenesulfonic acid is mixed in at about 0.2 to 1% of the solid content of the resin. After adjusting the resin adhesion amount by centrifugation or the like on a polyvinyl acetal synthetic resin porous body impregnated with a resin that can be converted into glassy carbon by thermal decomposition such as phenol resin or furan resin by such a method, it is heated at room temperature or under heating. Dry and further 120 ~
Cured at a high temperature of 180℃. Through this drying and curing process, the impregnated resin that has permeated into the porous body of the polyvinyl acetal synthetic resin containing ceramic is integrated with the porous body to form a composite porous body having continuous pores, which is then carbonized and activated as described below. This results in network-structured activated carbon that retains the network structure of the porous polyvinyl acetal synthetic resin. A second method for producing a composite porous body having continuous pores according to the present invention includes a method in which polyvinyl alcohol, a phenolic resin, and fine ceramic powder are mixed together with a pore-forming material, and the mixture is reacted in the presence of a crosslinking agent. The polyvinyl alcohol, fine ceramic powder, crosslinking agent, pore-forming material, etc. used in this method may be the same as those used in the production of the polyvinyl acetal synthetic resin porous body containing fine ceramic powder according to the first method described above. Further, as the phenolic resin, water-soluble resols and phenolic resin powders that have good miscibility with polyvinyl alcohol, crosslinking agents, and pore-forming materials are suitable. As the phenolic resin powder, cured phenolic resin powder, short phenolic resin fibers, pulverized fine powder of phenolic resin fibers, etc. can be used, but particularly reactive granular or powdered phenolic resin is preferred. The reactive granular or powdered phenolic resin of the present invention is a granular or powdered resin made of a condensate of phenols and formaldehyde, and has an infrared absorption spectrum of 1600 cm ^-1 ( D ₁₆₀₀ , 990 to 1015 cm
When the largest absorption intensity in the range of ^-1 (absorption peak attributed to the methylol group) is expressed as D ₉₉₀ to ₁₀₁₅ , 890cm ^-1 (absorption peak of the vertical hydrogen atom of the benzene nucleus) absorption intensity D ₈₀₀ , _A granular or powdery phenol formaldehyde resin having _D990-1015 / _D1600 = _0.2-9.0 , _D890 / _D1600 = 0.09-1.0, preferably _D990-1015 / _D1600 = 0.3-7.0 _{D890 /D1600=0.1-0.9} , particularly preferably _D990-1015 / _D1600 = _{0.4-5.0 D890} / _D1600 =0.12-0.8. In the infrared absorption spectrum, the peak at D ₁₆₀₀ indicates absorption attributed to the benzene nucleus, and the peak at D ₉₉₀ ~
The peak at ₁₀₁₅ shows an absorption attributed to the methylol group, and the peak at D ₈₉₀ shows an absorption attributable to the hydrogen atom of the benzene nucleus.
Formaldehyde resins are already widely known. The reactive granular or powdered phenolic resin used in the present invention has a D ₉₉₀ to ₁₀₁₅ / D ₁₆₀₀ = 0.2 to 9.0.
This characteristic value indicates that the resin contains at least a certain amount of methylol groups, and that the methylol group content can be adjusted within a fairly wide range. Especially D ₉₉₀ ~ ₁₀₁₅ = 0.3 ~ 7.0, especially 0.4 ~ 5.0
The resins preferred for use in the present invention contain moderate concentrations of methylol groups and are more stable. Furthermore, the resin has a D ₈₉₀ /D ₁₆₀₀ = 0.09 to 1.0 in the infrared absorption spectrum.
The fact that the resin exhibits a characteristic of D ₈₉₀ /D ₁₆₀₀ = 0.1 to 0.9, particularly 0.12 to 0.8, indicates that the reactive sites (ortho and para positions) of the phenol molecules involved in the reaction are formed by methylene bonds or methylol groups. This shows the fact that there is a moderate lockdown. To produce a composite porous body by the second method,
First, heat a predetermined amount of polyvinyl alcohol aqueous solution with stirring, add water-soluble phenolic resin to it, mix it, and if necessary, add reactive granular or powdered phenolic resin or other phenolic resin powder. Stir to mix. To this are added pore-forming materials such as fine ceramic powder dispersed in water and wheat flour starch in an aqueous solution or dispersion, and stirred. After cooling to about 40°C, aldehydes as a crosslinking agent and aldehydes as a catalyst are added. Add sulfuric acid, mix uniformly, transfer to a mold, and react. After the reaction is completed, the molded product taken out from the mold is washed to wash away aldehydes and acid that have not reacted with the pore-forming material. As described above, the composite porous body of the present invention can be produced by two methods, and the continuous porosity of the composite porous body is usually 50 to 92%, preferably 70 to 92%, and most preferably 80 to 92%. . Furthermore, the content of the resin that can be converted into glassy carbon in the composite porous body produced by the above two methods is usually 25 to 85% by weight, preferably 40 to 82% by weight, and most preferably 55 to 80% by weight. %. The content of ceramic fine powder in the composite porous body is usually 3
~10% by weight, preferably 4-9%, most preferably 4-8%. If the content of the resin that can be converted into glassy carbon in the composite porous material is extremely low, the weight loss and size reduction during the carbonization and activation processes become large, resulting in non-uniform deformation. Since the strength of the network activated carbon is significantly reduced, it cannot be put to practical use.
If the content of resin that can be converted into glassy carbon is excessive, exceeding 85% by weight, the porosity of the composite porous material will decrease, and the porosity of the network activated carbon obtained by carbonization activation will also decrease, resulting in a fluid The pressure loss during permeation increases and the properties of activated carbon having continuous pores are lost. When the content of the resin that can be converted into glassy carbon in the composite porous material is 25 to 85% by weight, dimensional changes during carbonization activation are small and the yield is high, and the continuous porosity is large and pressure loss is reduced. Activated carbon with a low network structure can be obtained. The effect of mixing fine ceramic powder into the composite porous body of the present invention is to suppress the occurrence of cracks due to stress generated during carbonization activation of the composite porous body. In a synthetic resin porous body that does not contain fine ceramic powder, cracks are more likely to occur as the activation conditions become more severe and the specific surface area increases, and as the sample shape becomes larger and more complex, but it is important to mix an appropriate amount of fine ceramic powder. This makes it possible to suppress the occurrence of cracks. When the content of the ceramic fine powder in the composite porous body is less than 3%, the effect of the ceramic fine powder on suppressing cracks is hardly recognized. Furthermore, if the content of fine ceramic powder exceeds 10%, the proportion of fine ceramic powder in the network structure activated carbon after carbonization activation becomes too large, the specific surface area of the activated carbon structure decreases, and the adsorption capacity decreases. Problems arise, such as the strength being significantly lowered. The content of ceramic fine powder in the composite porous body is 3 to 10% by weight.
In this case, network-structured activated carbon with high strength and specific surface area can be obtained without cracks occurring during carbonization activation even for samples with complex shapes and large dimensions. Furthermore, other synthetic resins such as melamine resins, epoxy resins, mixtures of vinyl polymers and divinyl compounds, urea resins, unsaturated polyester resins, pitch, tar, etc. are applied to the above composite porous body. You may. These resins can be easily applied, for example, by impregnating the composite porous body with a resin solution or a mixture of these resins and a resin that can be converted into glassy carbon by thermal decomposition. After producing the composite porous body as described above, the composite porous body is subjected to an activation treatment. The activation treatment may be performed by either a gas activation method or a chemical activation method. In the gas activation method, carbonization and activation can be performed in two steps, or carbonization and activation can be performed simultaneously as one step. When carbonization and activation are performed separately in the gas activation method, the combined The porous body is usually carbonized and fired at a temperature of 600°C or higher. Next, activation treatment is performed at a predetermined temperature in an atmosphere of water vapor, carbon dioxide gas, air, or a mixed gas thereof. The temperature and time of the activation treatment are appropriately determined depending on the porosity, pore diameter, shape, desired specific surface area, atmosphere, etc. of the composite porous body. For example, in the case of a steam or carbon dioxide atmosphere, the activation treatment is usually carried out at 500 to 1200°C, preferably 700 to 1000°C, for several minutes to several hours. When carbonization and activation are performed simultaneously using a gas activation method, the temperature of the composite porous body is generally raised in a steam or carbon dioxide atmosphere, and the process is carried out at a predetermined temperature of 500 to 1200° C. for a predetermined period of time. In the case of the chemical activation method, carbonization and activation are performed simultaneously by firing a composite porous material with continuous pores containing zinc chloride, phosphoric acid, potassium sulfide, etc. at 400 to 1000°C in a non-oxidizing atmosphere. be able to. To impart chemicals to the composite porous material, e.g.
A composite porous body may be impregnated with an aqueous solution of Zncl ₂ and then dried, or a polyvinyl acetal synthetic resin porous body containing fine ceramic powder with continuous pores is impregnated with an aqueous Zncl ₂ solution, dried, and then converted into glassy carbon. A resin that can be used may also be applied. Since the composite porous material of the present invention contains fine ceramic powder, activation proceeds uniformly throughout the sample even in large-sized samples with complex shapes, and the specific surface area is increased without causing cracks in the sample. It is possible to obtain activated carbon with a network structure that is large and strong. In addition, the network activated carbon is an activated carbon with a high continuous porosity consisting of uniformly distributed pores, and has both the adsorption function and filter function of ordinary activated carbon. Such network activated carbon is effective as various adsorbents and can also remove fine particles in liquids and dust in the air, so it is significantly simpler than the conventional method of using an activated carbon layer and other filters. be. Furthermore, the activated carbon has the advantage that it does not have problems such as pulverization or uneven density during use or transportation, unlike granular or fibrous activated carbon, and can significantly reduce pressure loss. Further, depending on the use, the network activated carbon may be used after its surface is coated with a hydrophilic acrylic polymer, collodion, gelatin, or the like. The network activated carbon with continuous pores of the present invention is
Taking advantage of the above advantages, it can be extremely effectively used for adsorption of various harmful gases and various compounds, purification of contaminated air, sewage treatment, etc. Furthermore, it is highly useful as an easy-to-handle activated carbon in decolorizing, deodorizing, and colloid removal in pharmaceutical manufacturing processes, and in the production of industrial ultrapure water. Furthermore, the activated carbon forms a reticular skeleton and does not allow carbon powder to fall off, making it ideal as activated carbon for artificial organs. In addition to the above, if the network-structured activated carbon supports an acid such as sulfuric acid, it will be possible to obtain a carbon with excellent ability to remove basic compounds such as ammonia and various amines from the air. By supporting hydroxides, carbonates, or manganese oxides of alkali metals such as hydroxides, carbonates, or manganese oxides, products with better ability to remove sulfur dioxide gas, nitrogen oxides, etc. can be obtained, and can be used for air purification. In addition, palladium is added to the activated carbon.
When a noble metal such as platinum is supported, a catalyst filter capable of oxidizing carbon monoxide, hydrocarbons, etc. at low temperatures can be obtained. Furthermore, the activated carbon is also effective as activated carbon for canisters to suppress evaporative loss of fuel in automobiles. The present invention will be specifically explained below using Examples. Example 1 Polyvinyl alcohol (PVA) with a degree of polymerization of 1700 and a degree of saponification of 99%, fine silica sand powder (average powder diameter 30μ)
m), a reactive powdered phenolic resin (average powder diameter 40 μm), and a water-soluble resol resin (Sumitomo Durez Co., Ltd. product, PR961A, solid content 65% by weight) with a solid content ratio as shown in Table 1. It was weighed so that the total solid content was 2 kg. First, PVA was dispersed in water and dissolved by heating, and then reactive granular phenol resin, water-soluble resol resin, and fine silica sand powder, which had been previously dispersed in water, were added and thoroughly stirred and mixed while heating. 60
When the temperature reaches ℃, add flour starch of the specified particle size.
Add 340g of water dispersion and heat to 70-80℃ while stirring.
heated until. After cooling this mixture to 40° C., 900 ml of 37% formalin and 600 ml of 50% sulfuric acid were added and mixed, and the liquid volume of the mixture was adjusted to 10 by adding a small amount of water. The mixture was poured into a cylindrical mold, heated at 60°C for 18 hours, and then removed from the mold.
Washed with shower for 24 hours, outer diameter 200mmφ, inner diameter 100
A composite porous body having continuous pores containing fine silica sand powder and having a diameter of mmφ and a length of 400 mm was obtained. The average pore diameter of the composite porous body was 15 μm. This composite porous material is placed in an electric furnace and placed in a nitrogen atmosphere.
The temperature was raised to 850°C at a heating rate of 100°C/hr for carbonization, and then the nitrogen gas containing water vapor obtained by flowing nitrogen gas into 80°C hot water at a flow rate of 10/min was heated into an electric furnace. The network structure activated carbon shown in Table 1 was obtained by introducing the activated carbon into the solution and activating it at 850° C. for a predetermined period of time. As can be seen from Table 1, even in relatively large samples such as those of this example, by mixing an appropriate amount of fine ceramic powder, network activated carbon having a large specific surface and good shape retention was obtained. If the silica sand content is too low, cracks will occur, and if the silica sand content is too high, the carbon content in the network activated carbon will be too small, resulting in a decrease in strength and a tendency to collapse.

[Table] Example 2 Polyvinyl alcohol with a degree of polymerization of 1000 and a degree of saponification of 99% was dispersed in water, then heated and dissolved, and bentonite fine powder (produced by Toyosun Yoko Co., Ltd., trade name) previously dispersed in water. Bengel) was added and mixed by stirring. When the temperature of the mixture reaches 60℃, add the potato starch aqueous dispersion and heat to 70-80℃ while stirring.
heated to. After cooling this liquid mixture to 40°C, a 30% aqueous benzaldehyde solution and a 50% aqueous sulfuric acid solution were added and mixed uniformly. The amount of each raw material is the total of polyvinyl alcohol and bentonite fine powder.
600g, potato starch 260g, 30% benzaldehyde
500 ml, 50% sulfuric acid 440 ml, and finally, a small amount of water was added to the mixed solution to adjust the liquid volume to 5.
The solution was poured into a mold with an outer diameter of 100 mmφ and a length of 500 mm, heated at 60°C for 20 hours, and then demolded to obtain a polyvinylbenzal porous body containing bentonite fine powder from which starch and unreacted substances had been washed away. Ta. The average pore diameter of the porous body was 30 to 50 μm. The polyvinylbenzal porous material containing the bentonite fine powder described above is immersed in furan resin with a solid content concentration of 40% (Hitachi Chemical Co., Ltd. product, Hitafuran 302, containing 0.2% curing agent) diluted with acetone, and the specified resin is After squeezing to the desired amount of adhesion, it was dried and cured at 90°C for 18 hours, and further cured at 120°C for 30 minutes to obtain a composite porous body. The composite porous body containing a predetermined amount of furan resin thus obtained was placed in an electric furnace and placed in a nitrogen atmosphere.
The temperature was raised to 650°C at a heating rate of 150°C/hr, and then activated while raising the temperature to 900°C over a predetermined period of time in a steam atmosphere. A steam atmosphere was created by introducing nitrogen gas into an electric furnace, which was flowed at a flow rate of 10/min into hot water at 80°C. Table 2 shows the physical properties of the obtained network activated carbon.

[Table] As can be seen from Table 2, in Sample 1, in which the furan resin content was too low, the sample deformed unevenly during activation, and good network structure activated carbon could not be obtained.
In addition, in sample 6, which had too much furan resin content, the continuous porosity was low, making it difficult for uniform activation to proceed to the inside of the sample, resulting in large variations in surface area depending on location. In addition, since the obtained activated carbon had a small surface area and a low glassy carbon content, the pressure loss of the fluid was large and it could not be put to practical use. Samples 2 to 5 containing an appropriate amount of furan resin gave activated carbon with a good network structure. Example 3 In the same manner as in Example 1, by using Kibushi clay (average particle size 20 μm) as the ceramic fine powder and n-butyraldehyde as the crosslinking agent,
42% by weight polyvinyl butyral, 8% by weight Kibushi clay, 50% by weight reactive granular phenolic resin
A flat composite porous body (average pore diameter 20 μm) of 40×400×300 mm was prepared. Furthermore, the porous composite material was mixed with a resol resin methanol solution (product of Gunei Chemical Industry Co., Ltd.) with a solid content concentration of 35% by weight.
PL-3206), centrifuged, and dried and hardened at 130°C for 2 hours. The resulting composite porous body contained 25% by weight of polyvinyl butyral, 5% by weight of Kibushi clay, and 70% by weight of total phenolic resin. This composite porous material was immersed in a 50% by weight Zncl ₂ aqueous solution, dried, and placed in an electric furnace at 700°C in a nitrogen atmosphere.
The carbon was maintained for 45 minutes, cooled, and then washed with water to obtain activated carbon with a good network structure having a specific surface area of 1310 m ² /g and a continuous porosity of 80%.

Claims (1)

[Scope of Claims] 1. A resin component in a composite porous body having continuous pores consisting of a polyvinyl acetal-based synthetic resin, a resin that can be converted into glassy carbon by thermal decomposition, or a resin containing these as its main component, and ceramic fine powder. A method for producing network activated carbon having continuous pores, which is characterized by carbonization and activation. 2. Claim 1, wherein the composite porous body having continuous pores is a polyvinyl acetal-based synthetic resin porous body containing fine ceramic powder, to which a resin that can be converted into glassy carbon by thermal decomposition is added.
2. Method for producing network activated carbon as described in Section 1. 3. The method for producing network activated carbon according to claim 2, wherein the polyvinyl acetal synthetic resin is polyvinyl formal or polyvinyl benzal. 4. The composite porous body having continuous pores is a porous body obtained by mixing polyvinyl alcohol, phenolic resin, and fine ceramic powder with a pore-forming material and reacting the mixture with a crosslinking agent. A method for producing network activated carbon according to any one of the above. 5 A composite porous body having continuous pores is obtained by mixing polyvinyl alcohol, phenolic resin, and fine ceramic powder with a pore-forming material, and reacting the mixture with a crosslinking agent, and a resin that can be further converted into glassy carbon by thermal decomposition. A method for producing network activated carbon according to any one of claims 1 to 3. 6. The method for producing network activated carbon according to claim 2 or 5, wherein the resin that can be converted into glassy carbon by thermal decomposition is a phenolic resin or a furan resin. 7. The method for producing network activated carbon according to claim 4 or 5, wherein the crosslinking agent is formaldehyde or benzaldehyde. 8 The content of resin that can be converted into glassy carbon by thermal decomposition in the composite porous body having continuous pores is 25 to 25%.
A method for producing network activated carbon according to claim 1, wherein the content is 85% by weight. 9. The method for producing network activated carbon according to claim 1, wherein the content of ceramic fine powder in the composite porous body having continuous pores is 3 to 10% by weight. 10. The net-like structure according to claim 1, wherein the carbonization and activation are carried out by carbonizing and firing the composite porous body in a non-oxidizing atmosphere, and then heating the composite porous body to 500 to 1200° C. in a steam or carbon dioxide atmosphere for activation. Method for producing structural activated carbon. 11. The method for producing network activated carbon according to claim 1, wherein the carbonization and activation are carried out by heating the composite porous body at 500 to 1200°C in a steam or carbon dioxide atmosphere, and carbonizing and activating it. 12 Carbonization and activation of zinc chloride,
The method for producing network activated carbon according to claim 1, which is carried out by adding phosphoric acid or potassium sulfide, heating it to 400 to 1000°C in a non-oxidizing atmosphere, and carbonizing and activating it.