JP6174556B2 - Modified activated carbon, method for producing the same, and filtration cartridge - Google Patents

Description

  The present invention relates to a technique using activated carbon.

  In order to remove a trace amount of organic halogen compounds (such as trihalomethane) contained in tap water, a water purifier having activated carbon is used. Plant-derived activated carbon such as coconut shell activated carbon has pores with various diameters (D) from micropores to macropores. Here, in the IUPAC (International Union of Pure and Applied Chemistry), pores smaller than 2 nm in diameter (D = 2) are defined as micropores, and pores having a diameter of 2 nm to 50 nm. Are defined as mesopores, and pores larger than 50 nm in diameter (D = 50) are defined as macropores. For example, chloroform (trichloromethane), which is a representative example of trihalomethane existing in a very small amount in tap water, is not adsorbed by micropores having a peak of pore size distribution at about 0.7 nm, not macropores or mesopores. Thus, an organic halogen compound such as trihalomethane is easily adsorbed to micropores having a diameter of less than 2 nm, but is difficult to adsorb to mesopores and macropores.

  In order to increase the number of micropores among the pores, it is conceivable to reduce the activation degree of the activated carbon. However, activated carbon with a low degree of activation has a small pore volume, so that the adsorption amount of trihalomethanes is small when viewed in unit volume of activated carbon. Patent Document 1 discloses that activated carbon is heat-treated in a nitrogen gas atmosphere within a range of 1200 to 1700 ° C. in order to increase the adsorption amount of trihalomethanes.

JP-A-8-26711

The techniques described above, it is necessary to heat treating the activated carbon at a very high temperature and 1200 to 1700 ° C. after having prepared a nitrogen gas atmosphere to increase the adsorption amount of trihalomethanes.

The present invention has an object to provide a novel modified activated carbon and a filtration cartridge having an increased number of micropores per unit volume .

The modified activated carbon of the present invention has a mode in which powdered activated carbon for removing the substance to be removed enters the macropores of the activated carbon.
Moreover, the method for producing the modified activated carbon of the present invention includes activated carbon having an average particle diameter D1 having macropores, powdered activated carbon having an average particle diameter D2 (D2 <D1) for removing a substance to be removed, and a dispersion medium, a mixture of materials including putting powdered activated carbon of the average particle diameter D2 to the macropores of the activated carbon of the average particle diameter D1, a modified activated carbon containing the powdery activated carbon into the macropores of the activated carbon Having an aspect to manufacture.
Furthermore, this invention has the aspect of the filtration cartridge using the modified activated carbon in which the powdery activated carbon for removing the substance of removal object entered into the macropore of activated carbon.

That is, since the powdered activated carbon is contained in the macropores larger than 50 nm in diameter among the pores in the activated carbon, an increase in the volume of the modified activated carbon due to the presence of the powdered activated carbon is suppressed. This aspect can provide a novel modified activated carbon having an increased number of micropores per unit volume . In addition, the material containing activated carbon, powdered activated carbon, and a liquid dispersion medium includes both a material including only the three kinds of raw materials and a material including a raw material different from the three kinds of raw materials.

  Furthermore, in the method for producing the modified activated carbon of the present invention, the predetermined size generated from a part of the activated carbon by mixing a material containing activated carbon having macropores larger than the predetermined size and a liquid dispersion medium. A modified activated carbon in which the powdered activated carbon is placed in the macropores of the activated carbon by performing the step of removing the powdered activated carbon having the predetermined size or less that has not entered the macropores by putting the following powdered activated carbon in the macropores Having an embodiment.

  That is, since the powdered activated carbon is contained in the macropores larger than 50 nm in diameter among the pores in the activated carbon, an increase in the volume of the modified activated carbon due to the presence of the powdered activated carbon is suppressed. Moreover, since the process of removing the powdery activated carbon below a predetermined size is performed, the aggregate of the modified activated carbon is less likely to be clogged. In addition, the material containing activated carbon larger than a predetermined size and the liquid dispersion medium includes both a material including only the two kinds of raw materials and a material including a raw material different from the two kinds of raw materials.

In the inventions according to claims 1 to 4 , it is possible to provide a novel modified activated carbon having an increased number of micropores per unit volume.
In the invention which concerns on Claim 5 , the filtration cartridge using the novel modified activated carbon which increased the micropore per unit volume can be provided.

The figure which illustrates typically the structure of modified activated carbon. The figure which illustrates typically the surface of modified activated carbon. (A), (b) is a flowchart which shows the example of the manufacturing method of modified activated carbon typically. The flowchart which shows the example of the manufacturing method of modified activated carbon typically. The figure which shows the example of a water purification cartridge typically. 3 is a photograph showing the surface of the modified activated carbon of Example 1. 3 is a photograph showing the surface of the modified activated carbon of Example 2. The photograph which shows the surface of the modified activated carbon of Reference Example 1 .

  Embodiments of the present invention will be described below. Of course, the following embodiments are merely examples of the present invention, and all the features shown in the embodiments are not necessarily essential to the means for solving the invention.

(1) Overview of modified activated carbon:
1-5 has shown the example of the modified activated carbon of this technique, its manufacturing method, and its utilization method. 1 to 5 are schematic diagrams, and the enlargement ratio in each direction shown in these diagrams may be different, and the diagrams may not be consistent.

The modified activated carbon 1 of the present technology shown in FIG. 1 has a structure in which a powdery functional substance 20 for removing a substance to be removed enters a macropore 14 of the activated carbon 10. Activated carbon 10 shown in FIG. 1 has, as pores 11, micropores 12 having a diameter D smaller than 2 nm, mesopores 13 having a diameter D of 2 nm to 50 nm, and macropores 14 having a diameter D larger than 50 nm. Have. In addition, the diameter of the pore when actually measured is to be measured at the opening of the pore appearing in a planar observation field such as a photographed image, and if the opening is non-circular, the major axis and minor axis phases are measured. The arithmetic mean. The diameter Dmacro of the macropore 14 is smaller than the diameter of the individual activated carbon 10 and is generally larger than the diameter of the individual functional material 20 that has entered the macropore 14. In addition, the diameter of the object to be measured (activated carbon and functional substance) when actually measured is to be measured in a flat observation field. If the object to be measured on the observation field is non-circular, the major axis and the minor axis are measured. Arithmetic average. FIG. 1 shows an average particle diameter D1 obtained by averaging the diameters of the individual activated carbons 10 and an average particle diameter D2 obtained by averaging the diameters of the individual functional substances 20. Depth length L of the macropores 14 typically have length than the diameter Dmacro macropores 14.

In tap water, there are trace amounts of organic halogen compounds such as trihalomethanes (those in which 3 hydrogen atoms in 4 hydrogen atoms contained in methane molecules are substituted with halogen atoms) generated by adding chlorine. Trihalomethane includes chloroform, bromodichloromethane, dibromochloromethane, bromoform, and the like, but it is mainly chloroform and bromodichloromethane that are present in tap water. Here, chloroform is easily adsorbed by the micropores 12 having a pore size distribution peak at about 0.7 nm. In addition, 1,1,1-trichloroethane (one in which three hydrogen atoms in six ethane atoms are replaced by chlorine atoms) is a micropore having a peak of pore size distribution at about 1 nm. 12 is easily adsorbed.
As described above, the organic halogen compound existing in tap water is not easily adsorbed to the micropores 12 having a diameter of less than 2 nm, not the macropores 14 and the mesopores 13.

The powdery functional substance 20 only needs to have a function of removing the substance to be removed, and may be powdered activated carbon as shown in FIG. 3B, or an ion exchanger such as zeolite (zeolite) or ion exchange resin, A catalyst such as titanium or titanium oxide may be used. When a large amount of the functional substance 20 enters the macropores 14, a large number of functions by the functional substance 20 are imparted to the modified activated carbon 1. In addition, when the functional substance 20 is the powdered activated carbon 21, the activated carbon 10 is also called a main activated carbon and the powdered activated carbon 21 is also called a secondary activated carbon.
The macropores 14 of the activated carbon 10 of the modified activated carbon 1 may contain 1 part by weight or more of the powdered functional substance 20 with respect to 100 parts by weight of the activated carbon 10, and may be 2 parts by weight or more, 3 parts by weight or more. 5 parts by weight or more, 7 parts by weight or more, and further 10 parts by weight or more may be contained. In addition, the upper limit of the amount of the powdery functional substance 20 entering the macropores 14 may be a blending ratio of the powdery functional substance 20 mixed with the activated carbon 10.

  FIG. 2 shows an example in which the functional substance 20 entering the macropores 14 is quantified. On the surface of the activated carbon 10, an opening of the macro hole 14 appears. Here, when the surface of the modified activated carbon 1 is observed, the total number of macropores 14 observed in the unit area of the observation field (for example, 50 μm square) is Nm, and the number of macropores containing the functional substance 20 observed. (The number excluding the macro holes 14a in which the functional substance 20 is not included in the macro holes 14) is defined as Ni. The 50 μm square means a square having a side of 50 μm. The quantitative value of the functional substance 20 can be expressed by, for example, the ratio Ni / Nm of the macropores 14 containing the functional substance 20. The modified activated carbon 1 of the present technology can satisfy Ni / Nm ≧ 0.5 (50% or more), and Ni / Nm ≧ 0.6 (60% or more), Ni / Nm ≧ 0.7 ( 70% or more), Ni / Nm ≧ 0.8 (80% or more), Ni / Nm ≧ 0.9 (90% or more).

  The macro hole 14 may contain one functional substance 20 or may contain two or more functional substances 20. Here, the number of functional substances 20 entering the macropores 14 observed in the unit area (for example, 50 μm square) of the observation field when the surface of the modified activated carbon 1 is observed is defined as Nf. The quantitative value of the functional substance 20 can also be expressed by the number of functional substances Nf per unit area. The modified activated carbon 1 of the present technology can satisfy Nf ≧ 10, and can also satisfy Nf ≧ 20, Nf ≧ 30, Nf ≧ 50, and Nf ≧ 100. You may provide a minimum in the magnitude | size of the functional substance 20 counted as the number Nf. This lower limit can be variously set to 0.1 μm, 0.2 μm, 0.3 μm, 0.5 μm, 1 μm, 2 μm, and the like depending on the type of the functional substance 20.

(2) Specific examples of modified activated carbon and its production method:
Next, with reference to FIGS. 1-4, the specific example of the modified activated carbon 1 and its manufacturing method is demonstrated.
FIG. 3A schematically shows an example of a method for producing the modified activated carbon 1. This example is an example of a method for producing modified activated carbons 2 to 4 using at least activated carbon 10, functional material 20, and water (liquid dispersion medium) 30. The liquid dispersion medium means a liquid dispersion medium. The modified activated carbons 2 to 4 are collectively referred to as modified activated carbon 1.

  The carbonaceous material used as the raw material of the activated carbon 10 should just be able to form the activated carbon which has a macropore by activating, and a plant-type carbonaceous material etc. can be used. As the plant-based carbonaceous material, fruit shells such as coconut shells and almond shells, wood, sawdust, bamboo, grass and the like can be used. Activation is a reaction that develops micropores in the carbonaceous material. Examples of the activation include gas activation for high-temperature treatment in the presence of water vapor, carbon dioxide, air, etc., chemical activation for chemical treatment with zinc chloride, sulfate, phosphoric acid, etc., activation using a combination of chemical and water vapor, etc. . Activation of the carbonaceous material includes activation treatment after carbonization treatment. The carbonization treatment can be, for example, a treatment for carbonizing a carbonaceous material at 600 to 800 ° C. in an inert atmosphere such as nitrogen or argon. The activation treatment after the carbonization treatment can be, for example, a treatment for activating the carbonaceous material at 700 to 1100 ° C., more preferably 800 to 1000 ° C. in an atmosphere of an oxidizing gas such as water vapor or carbon dioxide. .

  For the activated carbon 10 having the macropores 14, activated carbon having various shapes such as granular, pulverized, powdered, and fibrous can be used. When the average particle diameter can be obtained, the average particle diameter D1 of the activated carbon 10 is larger than the average particle diameter D2 of the functional substance 20, for example, 10 μm or more, 20 μm or more, 30 μm or more, 50 μm or more, 100 μm or more, etc. And can be set variously. The upper limit side of the average particle diameter D1 of the activated carbon 10 can be variously set, for example, 1000 μm or less, 500 μm or less, 300 μm or less, and the like. In addition, the average particle diameter in this application is a particle diameter distribution based on JIS K5600-9-3: 2006 (Paint general test method-Part 9: Powder paint-Section 3: Measuring method of particle size distribution by laser diffraction). To JIS Z8819-2 (Expression of particle diameter measurement result-Part 2: Average particle diameter from particle diameter distribution or calculation of average particle diameter and moment).

  The average particle diameter D2 of the powdered functional material 20 such as the powdered activated carbon 21, the ion exchanger, and the catalyst shown in FIG. 3B is made smaller than the average particle diameter D1 of the activated carbon 10. Since the individual functional materials 20 need only enter the macropores 14 and may be partially pulverized in the mixing step S1, the average particle diameter D2 of the functional materials 20 may be larger than the diameter Dmacro of the macropores 14. The average particle diameter D2 of the functional substance 20 can be variously set to, for example, 50 μm or less, 30 μm or less, 20 μm or less, 10 μm or less, 5 μm or less, and the like. The lower limit of the average particle diameter D2 of the functional substance 20 is variously set, for example, 50 nm or more, 0.1 μm or more, 0.2 μm or more, 0.3 μm or more, 0.5 μm or more, 1 μm or more, 2 μm or more, etc. can do. When a hollow fiber membrane is disposed after the modified activated carbon 1 in a filtration cartridge using the modified activated carbon 1, if the particle size of the functional substance 20 is larger than the pore diameter of the hollow fiber membrane, the function not entering the macropores 14 is achieved. Even if the substance 20 flows out of the modified activated carbon 1, it is captured by the hollow fiber membrane. The average particle diameter D2 of the functional substance 20 is preferably larger than the pore diameter of the hollow fiber membrane. For example, when the pore diameter of the hollow fiber membrane is 0.1 μm, the average particle diameter D2 of the functional substance 20 is preferably 0.2 μm or more.

  The secondary activated carbon (powdered activated carbon 21) as the functional substance 20 may or may not have macropores. The carbonaceous material that is the raw material of the secondary activated carbon is only required to be able to form activated carbon by activation, and plant-based, coal-based, petroleum-based, synthetic resin-based, natural material-based, various organic ash, etc. may be used. it can. Similar to the main activated carbon 10, fruit shells such as coconut shells and almond shells, wood, sawdust, bamboo, grass, and the like can be used as the plant carbonaceous material. As the coal-based carbonaceous material, peat, lignite, and charcoal, bituminous coal, anthracite, or the like can be used. Petroleum pitch or the like can be used as the petroleum-based carbonaceous material. As the synthetic resin-based carbonaceous material, phenol resin, epoxy resin, urea resin, polyamide resin, polyvinyl alcohol resin, polyacrylonitrile resin, polyolefin resin, and the like can be used. As the natural carbonaceous material, natural fibers such as cotton, regenerated fibers such as rayon, semi-synthetic fibers such as acetate, and the like can be used. The activation conditions for generating the secondary activated carbon are the same as the activation conditions for generating the main activated carbon.

  The amount of the sub activated carbon to be mixed is preferably 0.5 parts by weight or more, more preferably 1 part by weight or more, more preferably 2 parts by weight with respect to 100 parts by weight of the main active carbon from the viewpoint of sufficiently obtaining a substance removing function by the sub active carbon. The above is more preferable. Further, from the viewpoint of reducing the amount of secondary activated carbon that does not enter the macropores 14, the amount of secondary activated carbon is preferably 30 parts by weight or less, more preferably 20 parts by weight or less, and more preferably 10 parts by weight or less with respect to 100 parts by weight of the primary activated carbon. Is more preferable. In addition, the weight ratio of the secondary activated carbon mixed with respect to the primary activated carbon may be the upper limit of the weight ratio of the secondary activated carbon entering the macropore to the primary activated carbon.

As the ion exchanger as the functional substance 20, an inorganic ion exchanger such as zeolite, an ion exchange resin such as a cation exchange resin or an anion exchange resin, a chelate compound such as a chelate resin, or the like can be used. Zeolite and cation exchange resin adsorb metal ions by a cation exchange function. The chelate compound selectively adsorbs a specific metal ion through a chelate bond. That is, Ze zeolite and cation exchange resin and chelate compounds function as metal treatment agents. As the catalyst as the functional substance 20, a transition metal such as titanium or copper, a transition metal compound, or the like can be used.
In addition, the functional substance 20 may be used in combination of two or more kinds of substances selected from powdered activated carbon 21, ion exchangers, and catalysts.

  The compounding amount of the functional substance 20 (the compounding amount of the combined substances when two or more substances are combined) is based on 100 parts by weight of the activated carbon 10 from the viewpoint of sufficiently obtaining a substance removing function by the functional substance 20. 0.5 parts by weight or more is preferable, 1 part by weight or more is more preferable, and 2 parts by weight or more is more preferable. Further, from the viewpoint of reducing the functional substance 20 that does not enter the macropores 14, the blending amount of the functional substance 20 is preferably 30 parts by weight or less, more preferably 20 parts by weight or less with respect to 100 parts by weight of the activated carbon 10. More preferred are parts by weight or less. The weight ratio of the functional substance 20 to be mixed with the activated carbon 10 may be the upper limit of the weight ratio of the functional substance 20 entering the macropores with respect to the activated carbon 10.

  A liquid dispersion medium such as water 30 or alcohol (for example, methanol or ethanol) facilitates the retention of the powdery functional substance 20 in the macropores 14 of the activated carbon 10. In general, for particles with a particle size of 1 mm or less, electrostatic adhesion and van der Waals force are stronger than gravity, and liquid bridge adhesion force is more than electrostatic adhesion and van der Waals force. Is strong. If there is no liquid dispersion medium, it is estimated that van der Waals force and electrostatic adhesion force work between the activated carbon 10 and the functional material 20, but the liquid dispersion medium is held between the activated carbon 10 and the functional material 20. Thus, it is presumed that a strong attractive force called liquid cross-linking adhesion acts between the activated carbon 10 and the functional substance 20.

  The blending amount of the water 30 is preferably 50 parts by weight or more, more than 80 parts by weight with respect to 100 parts by weight of the activated carbon 10 and the functional substance 20 in order to exert a strong attractive force between the activated carbon 10 and the functional substance 20. Is more preferable, and 100 parts by weight or more is more preferable. The upper limit of the amount of water 30 is preferably 200 parts by weight or less, more preferably 150 parts by weight or less, and still more preferably 120 parts by weight or more with respect to 100 parts by weight of the activated carbon 10 and the functional substance 20 combined.

  The material to be mixed may be only a combination of the activated carbon 10, the powdery functional substance 20, and the water 30. However, for example, about 0.1 to 60 parts by weight of the additive 40 may be added to 100 parts by weight of the activated carbon 10. . The additive 40 may be a functional substance (excluding activated carbon) having an average particle diameter larger than the average particle diameter D2 of the powdered functional substance 20. Although the functional substance as the additive 40 does not enter the macropores 14 of the activated carbon 10, the substance removal function by the additive 40 can be imparted to the modified activated carbon 1. The amount of water 30 in the case of adding the additive 40 is that the activated carbon 10, the functional substance 20, and the additive 40 are combined from the point that a strong attractive force acts between the activated carbon 10, the functional substance 20 and the additive 40. The amount is preferably 50 parts by weight or more, more preferably 80 parts by weight or more, and still more preferably 100 parts by weight or more with respect to 100 parts by weight. The upper limit of the amount of water 30 is preferably 200 parts by weight or less, more preferably 150 parts by weight or less, and 120 parts by weight or more with respect to 100 parts by weight of the activated carbon 10, the functional substance 20, and the additive 40 combined. Further preferred.

  In the mixing step S <b> 1, a material containing the activated carbon 10, the powdery functional substance 20, water 30 and, if necessary, the additive 40 is mixed and the powdery functional substance 20 is put into the macropores 14 of the activated carbon 10. The order of mixing the raw materials is not particularly limited, and may be charged simultaneously into the mixing device, or a slurry obtained by mixing the powdered functional material 20 and water 30 is mixed with the activated carbon 10 and, if necessary, the additive 40. May be. By mixing these raw materials, the modified activated carbon 2 in a wet state in which the functional substance 20 that does not enter the macropores 14 is obtained can be obtained. By the attractive force acting on the activated carbon 10 and the powdered functional material 20, the functional material 20 is retained in the macropores 14 of the activated carbon 10 even without a binder.

  When the functional substance 20 enters the macropores 14 of the activated carbon 10, an increase in the volume of the modified activated carbon due to the presence of the functional substance 20 is suppressed, and the function of the functional substance 20 is imparted to the modified activated carbon 2. That is, the modified activated carbon 2 is a new material in which the powdered functional substance 20 is contained in the modified activated carbon 1 that has entered the macropores 14 of the activated carbon 10 and the function of the functional substance is added while suppressing an increase in volume. .

  For mixing performed in the mixing step S1, manual mixing, mixer, blender, horizontal cylindrical type, V type, double cone type, square solid type, S type, continuous V type, ball mill type, rocking type, cross rotary Mixing devices such as molds, ribbon types, screw types, rotor types, pug mill types, planetary types, turbine types, high-speed flow types, rotating disk types, centrifugal types (devices that stir using centrifugal force), granulators, etc. Can be used. The mixing temperature is not particularly limited, and may be a temperature that does not use a heater or a cooler, such as a room temperature of about 20 ° C., or may be a temperature controlled to a target temperature of about 10 to 90 ° C., for example.

  As needed, you may perform the free functional substance removal process S2 which removes the functional substance 20 which is not contained in the macropore 14 after mixing process S1. For example, when the modified activated carbon 2 is placed on a sieve having a mesh of a predetermined size (for example, 50 μm) and the functional material 20 having a predetermined size or less is washed away with a liquid dispersion medium such as water, the functional material 20 that is not contained in the macropores 14. Thus, the modified activated carbon 3 in a wet state from which at least a part thereof is removed is obtained. The functional substance 20 that has entered the macropores 14 remains due to the attractive force with the activated carbon 10. When the particle size distribution of the modified activated carbon 3 is measured, the peak of the average particle diameter D2 of the powdered functional material 20 is hardly seen, and the peak of the average particle diameter D1 of the activated carbon 10 is seen.

  Since the functional substance 20 is contained in the macropores 14 of the activated carbon 10, an increase in the volume of the modified activated carbon due to the presence of the functional substance 20 is suppressed, and the function of the functional substance 20 is imparted to the modified activated carbon 3. ing. That is, the modified activated carbon 3 is a new material in which the powdered functional material 20 is included in the modified activated carbon 1 that has entered the macropores 14 of the activated carbon 10 and the function of the functional material is added while suppressing an increase in volume. . Further, by removing at least a part of the fine functional substance 20 that does not enter the macropores 14, the aggregate of the modified activated carbon used in the filtration cartridge such as the water purification cartridge is less likely to be clogged.

  The size of the sieve mesh can be variously set, for example, from 10 μm or more, 20 μm or more, 30 μm or more, 40 μm or more, etc. from the point of removing the powdery functional substance 20. The upper limit side of the mesh size can be variously set, for example, from 90 μm or less, 80 μm or less, 70 μm or less, 60 μm or less, etc. from the point of leaving the modified activated carbon 3.

  Further, if necessary, a step of removing a liquid dispersion medium such as water (for example, a drying step S3) may be performed after the free functional substance removing step S2 or the mixing step S1. For example, when the modified activated carbon 3 containing water is dried, the modified activated carbon 4 in a dry state in which at least a part of the functional substance 20 not entering the macropores 14 is removed is obtained. When the particle size distribution of the modified activated carbon 4 is measured, the peak of the average particle diameter D2 of the powdered functional material 20 is hardly seen, and the peak of the average particle diameter D1 of the activated carbon 10 is seen. The bulk specific gravity of the modified activated carbon 4 is larger than the bulk specific gravity of the activated carbon 10.

  The modified activated carbon 4 is a new material in which the powdered functional substance 20 is contained in the modified activated carbon 1 that has entered the macropores 14 of the activated carbon 10 and the function of the functional substance is added while suppressing an increase in volume. Moreover, the aggregate of the modified activated carbon used for the filtration cartridge is not easily clogged.

  FIG. 3B shows an example in which secondary activated carbon (powdered activated carbon 21) is used as the functional substance 20. That is, in the mixing step S <b> 1, a material including the main activated carbon 10, the powdered activated carbon 21, water 30 and, if necessary, the additive 40 is mixed and the powdered activated carbon 21 is put into the macropores 14 of the main activated carbon 10. Thereby, the modified activated carbon 2 in a wet state in which the powdered activated carbon 21 not entering the macropores 14 remains is obtained. By entering the powdered activated carbon 21 into the macropores 14 of the main activated carbon 10, an increase in the volume of the modified activated carbon due to the presence of the powdered activated carbon 21 is suppressed, and the number of micropores per unit volume is increased. That is, the modified activated carbon 2 is a new material in which the powdered activated carbon 21 is included in the modified activated carbon 1 in which the macropores 14 of the main activated carbon 10 are contained, and the number of micropores per unit volume is increased.

  In the manufacturing method shown in FIG. 3B, the free function substance removing step S2 and the drying step S3 may be performed as necessary. When the particle size distribution of the obtained modified activated carbons 3 and 4 is measured, the peak of the average particle diameter D2 of the powdered functional material 20 is hardly seen, and the peak of the average particle diameter D1 of the activated carbon 10 is seen. The bulk specific gravity of the modified activated carbon 4 is larger than the bulk specific gravity of the activated carbon 10. The specific surface area (volume basis) of the modified activated carbon 4 is larger than the specific surface area (volume basis) of the activated carbon 10. The total pore volume (volume basis) of the modified activated carbon 4 is larger than the total pore volume (volume basis) of the activated carbon 10. The modified activated carbon 4 has an organic halogen compound removing performance higher than that of the activated carbon 10. That is, the modified activated carbons 3 and 4 are new materials in which the powdered activated carbon 21 is included in the modified activated carbon 1 in the macro pores 14 of the main activated carbon 10 and the number of micropores per unit volume is increased. Moreover, the aggregate of the modified activated carbon used for the filtration cartridge is not easily clogged.

  Furthermore, a secondary activated carbon (powdered activated carbon 21) may be generated from a part of the main activated carbon 10 and put into the macropores 14 as in the manufacturing method shown in FIG. In the mixing step S11 shown in FIG. 4, the main activated carbon 10 larger than a predetermined size (for example, 50 μm), water (liquid dispersion medium) 30 and a material containing the additive 40 as necessary are mixed to mix the main activated carbon 10. Powdered activated carbon 21 having a predetermined size (for example, 50 μm) or less generated from the part is put into the macropores 14. The predetermined size can be variously set, for example, from 10 μm or more, 20 μm or more, 30 μm or more, 40 μm or more, etc. from the point of removing the powdered activated carbon 21 in the free functional substance removing step S2. The upper limit side of the predetermined size can be variously set, for example, 90 μm or less, 80 μm or less, 70 μm or less, 60 μm or less, etc. from the point that the modified activated carbon 3 is left in the free functional substance removing step S2.

  As described above, the modified activated carbon 2 in a wet state in which the powdered activated carbon 21 that does not enter the macropores 14 remains is obtained. When the powdered activated carbon 21 generated from a part of the main activated carbon 10 larger than the predetermined size enters the macropores 14 of the main activated carbon 10, an increase in the volume of the modified activated carbon due to the presence of the powdered activated carbon 21 is suppressed, The number of micropores per unit volume increases. That is, the modified activated carbon 2 shown in FIG. 4 is also a new material in which the powdered activated carbon 21 is included in the modified activated carbon 1 in the macropores 14 of the main activated carbon 10 and the number of micropores per unit volume is increased.

  For the mixing performed in the mixing step S11, a mixing device that can be used in the mixing step S1 shown in FIG. 3A can be used. Here, in the mixing step S11, since a part of the main activated carbon 10 is pulverized, strong mixing such as increasing the rotation speed of the mixing device or extending the mixing time may be performed as compared with the case of the mixing step S1. The mixing temperature is the same as in the mixing step S1.

  Also in the manufacturing method shown in FIG. 4, the free functional substance removing step S <b> 2 and the drying step S <b> 3 may be performed as necessary. For example, when the modified activated carbon 2 is placed on a sieve having a mesh having a predetermined size (for example, 50 μm) and the powdered activated carbon 21 having a predetermined size or less is washed away with water, the powdered activated carbon 21 not entering the macropores 14 is washed away. The modified activated carbon 3 in a wet state from which at least a part has been removed is obtained (free functional substance removing step S2). When the modified activated carbon 3 is dried, the modified activated carbon 4 in a dry state from which at least a part of the powdered activated carbon 21 not entering the macropores 14 is removed is obtained (drying step S3). That is, the modified activated carbons 3 and 4 shown in FIG. 4 are also new materials in which the powdered activated carbon 21 is included in the modified activated carbon 1 in the macro pores 14 of the main activated carbon 10 and the number of micropores per unit volume is increased. is there. Moreover, the aggregate of the modified activated carbon used for the filtration cartridge is not easily clogged.

(3) How to use the modified activated carbon:
The modified activated carbon 1 can be used, for example, in a water purification cartridge (filtration cartridge) C1 as shown in FIG.
The water purification cartridge C1 shown in FIG. 5 is a central position surrounded by a cylindrical modified activated carbon filling chamber C2 and a modified activated carbon filling chamber C2 partitioned by a nonwoven fabric C3 on the inlet side and an ion exchange fiber C4 on the outlet side. The cylindrical hollow fiber membrane storage chamber C5 provided in the pipe is filtered, tap water flowing from the inlet C11 is filtered, and filtered water is discharged from the outlet C12. That is, the nonwoven fabric C3, the modified activated carbon 1, the ion exchange fiber C4, and the hollow fiber membrane C6 are used as the filter medium.

Nonwoven fabric C3 removes large debris from tap water flowing into inlet C11. The modified activated carbon 1 filled in the modified activated carbon filling chamber C2 adsorbs and removes free residual chlorine, organic substances, and the like. When the modified activated carbon 1 contains a metal treating agent, metal ions are removed. The ion exchange fiber C4 removes metal ions and the like. The ion exchange fiber C4 may be used in combination with activated carbon fiber or the like. The hollow fiber membrane C6 accommodated in the hollow fiber membrane accommodation chamber C5 removes fine turbidity of about 0.1 μm or more, iron rust and general bacteria.
In addition to the above, the modified activated carbon 1 can be used in an air cleaner or the like.

(4) Example:
EXAMPLES Hereinafter, although an Example is shown and this invention is demonstrated concretely, this invention is not limited by the following examples.

[Example 1]
As the main activated carbon, coconut shell activated carbon having an average particle size of 220 μm was used. The main activated carbon was pulverized with a pulverizer for 10 minutes to obtain a secondary activated carbon having an average particle diameter of 3.2 μm. The pulverizer was a blender PM-2005 manufactured by WARING, and pulverized at a high speed mode. The mixer used was a Kenwood tabletop mixer KM-800 (sold by Aikosha Seisakusho Co., Ltd.) with a Supermincer A-950 as an extrusion mechanism, and the screw shaft rotation speed was set to 40 rpm. A sieve having a mesh of 50 μm was used as an instrument for removing the sub-active carbon that did not enter the macropores.
5 g of secondary activated carbon and 205 g of water were mixed to form a slurry, and this slurry was sprinkled on 200 g of main activated carbon to obtain an initial mixture. This mixture was passed 5 times through the extrusion mechanism of the mixing device. When the mixture is passed through the extrusion mechanism N times (N is an integer of 3 or more), the mixture that has not been passed through the extrusion mechanism in the first time is put into the extrusion mechanism and extruded, and in the second to Nth time, the mixture extruded last time. It means to put into the extrusion mechanism and to extrude. Next, the treated mixture was placed on the sieve, and the secondary activated carbon not contained in the macropores was washed away with 1 L (liter) of water. Thereafter, the wet modified activated carbon remaining on the sieve was dried at 115 ° C. for 4 hours to obtain a modified activated carbon sample of Example 1.

[Example 2]
The same main activated carbon, secondary activated carbon, mixing device, and sieve were used as in Example 1.
10 g of secondary activated carbon and 215 g of water were mixed to form a slurry, and this slurry was sprinkled on 200 g of main activated carbon to obtain an initial mixture. This mixture was passed 40 times through the extrusion mechanism of the mixing device. Next, the treated mixture was placed on the above-mentioned sieve, and the sub activated carbon not contained in the macropores was washed away with 1 L of water. Thereafter, the wet modified activated carbon remaining on the sieve was dried at 115 ° C. for 4 hours to obtain a modified activated carbon sample of Example 2.

[Comparative Example 1]
The main activated carbon used in Example 1 was used as the modified activated carbon sample of Comparative Example 1.

[Measurement of bulk specific gravity]
For the modified activated carbon samples of Examples 1 and 2 and Comparative Example 1, the weight per unit volume was measured as the bulk specific gravity (unit: g / cm ³ ).

[Measurement of specific surface area based on volume]
For the modified activated carbon samples of Examples 1 and 2 and Comparative Example 1, the specific surface area (unit: m ² / g) was measured using BELSORP-max manufactured by Bell Japan Co., Ltd., and the specific surface area (unit: 1 cm ³ ) : M ² / cm ³ )

[Volume-based total pore volume measurement]
For modified activated carbon samples of Examples 1 and 2 and Comparative Example 1, Bel Japan using Ltd. BELSORP-max total pore volume (unit: cm ³ / g) and determined the total pore per sample 1 cm ³ The volume (unit: cm ³ / cm ³ ) was converted.

[Chloroform removal performance measurement]
50 cm ³ of the modified activated carbon samples of Examples 1 and 2 and Comparative Example 1 were put in a water purification cartridge, and the raw water adjusted to 0.060 mg / L chloroform according to JIS S3201: 2010 (house water purifier test method) Water was passed through a water purification cartridge, and the total amount of filtered water (unit: L) until the chloroform removal rate reached 80% or more was measured. In addition, the measurement of chloroform used Shimadzu Corporation GCMS-QP2010.

[Measurement of the number of secondary activated carbons in the macro holes]
The modified activated carbon samples of Examples 1 and 2 were photographed with the surface magnified with a microscope, and the approximate number of sub-activated carbons that entered the macropores observed in the 50 μm square of the observation field were measured.

[Test results]
FIG. 6 shows the surface of the modified activated carbon sample of Example 1, and FIG. 7 shows the surface of the modified activated carbon sample of Example 2. As shown in FIGS. 6 and 7, it can be seen that activated carbon is contained in accordance with the macropores of the main activated carbon. In Examples 1 and 2, there were 50 or more sub activated carbons that entered the macro holes observed in the 50 μm square of the observation field.

Table 1 shows the bulk specific gravity, the volume-based specific surface area, the volume-based total pore volume, and the total filtered water amount in the chloroform removal performance test for Examples 1 and 2 and Comparative Example 1.
As shown in Table 1, the bulk specific gravity was 0.52 in Comparative Example 1 but 0.54 in Example 1 and 0.58 in Example 2, which was larger than Comparative Example 1. It was. This is probably because activated carbon entered the macro pores of the main activated carbon. In Example 1, the activated carbon contained {(0.54-0.52) /0.52} = 3.8 parts by weight according to the macropores with respect to 100 parts by weight of the main activated carbon. In this case, the activated carbon contained {(0.58−0.52) /0.52} = 11.5 parts by weight with respect to 100 parts by weight of the main activated carbon.

As for the specific surface area (volume basis), Comparative Example 1 was 509 m ² / cm ³ , while Example 1 was 529 m ² / cm ³ and Example 2 was 567 m ² / cm ³ , compared with Comparative Example 1. Also became larger. This is considered to be because the surface area of the pores of the activated carbon was added according to the surface area of the pores of the main activated carbon.

The total pore volume (volume basis), whereas Comparative Example 1 was 0.218cm ³ / cm ^3, Example 1 is 0.227cm ³ / cm ^3, Example 2 is 0.244cm ³ / cm ³ , which was larger than Comparative Example 1. This is presumably because the pore volume of the activated carbon was added according to the pore volume of the main activated carbon.

  Regarding the total amount of filtered water in the chloroform removal performance test, Comparative Example 1 was 300 L, while Example 1 was 360 L and Example 2 was 490 L, which was larger than Comparative Example 1. From this, it can be seen that Examples 1 and 2 have improved organohalogen compound removal performance with sub activated carbon as compared with Comparative Example 1.

  From the above, the modified activated carbon containing activated carbon according to the macropores of the main activated carbon is a new material with increased micropores per unit volume, and it is a new material that suppresses the increase in volume and adds functions by functional substances. The material was confirmed.

[ Reference Example 1 ]
As the activated carbon, coconut shell activated carbon having an average particle size of 220 μm was used. As the powdered catalyst (functional substance), powdered titanium oxide having a particle size of about 0.2 to 0.5 μm was used. The same mixing apparatus and sieve as in Example 1 were used.
5 g of powdered titanium oxide and 205 g of water were mixed to form a slurry, and this slurry was sprinkled on 200 g of activated carbon to obtain an initial mixture. This mixture was passed 5 times through the extrusion mechanism of the mixing device. Next, the treated mixture was placed on the sieve, and the titanium oxide not contained in the macropores was washed away with 1 L of water. Thereafter, the wet modified activated carbon remaining on the sieve was dried at 115 ° C. for 4 hours to obtain a modified activated carbon sample of Reference Example 1 .

[Test results]
About the modified activated carbon sample of Reference Example 1 , the surface was magnified with a microscope and photographed, and the approximate number of sub activated carbons that entered the macropores observed in the 50 μm square of the observation field was measured. FIG. 8 shows the surface of the modified activated carbon sample of Reference Example 1 . In FIG. 8, the white shining particles are titanium oxide. As shown in FIG. 8, it can be seen that powdered titanium oxide is contained in the macropores of the activated carbon. In addition, there were 100 or more titanium oxides entering the macropores observed in the 50 μm square of the observation field. Therefore, the bulk specific gravity of Reference Example 1 is larger than the bulk density of Comparative Example 1, modified activated carbon of Example 1 is presumed to catalyst function is imparted by titanium oxide.

  As described above, the modified activated carbon in which powdered titanium oxide is contained in the macropores of the activated carbon is a new material in which the function of the functional substance is added while suppressing the increase in volume.

(5) Conclusion:
As described above, according to the present invention, according to various aspects, it is possible to provide a technology such as modified activated carbon to which an increase in volume is suppressed and a function of a functional substance is added. Needless to say, the above-described basic actions and effects can be obtained even with a technique that does not have the constituent requirements according to the dependent claims but includes only the constituent requirements according to the independent claims.
In addition, the configurations disclosed in the embodiments and modifications described above are mutually replaced, the combinations are changed, the known technology, and the configurations disclosed in the embodiments and modifications described above are mutually connected. It is possible to implement a configuration in which replacement or combination is changed. The present invention includes these configurations and the like.

1, 2, 3, 4 ... modified activated carbon,
10 ... activated carbon, 11 ... pore, 12 ... micropore, 13 ... mesopore, 14 ... macropore,
20 ... functional substances, 21 ... powdered activated carbon,
30 ... Water (liquid dispersion medium),
40 ... additives,
C1 ... Water purification cartridge (filtration cartridge),
S1, S11 ... mixing step, S2 ... free functional substance removing step, S3 ... drying step.

Claims (5)

Modified activated carbon in which powdered activated carbon for removing substances to be removed enters the macropores of the activated carbon. The modified activated carbon according to claim 1 , wherein there are 10 or more powdered activated carbons entering the macropores observed in the 50 μm square of the observation field when the surface of the modified activated carbon is observed. Activated carbon having an average particle size D1 having macropores, and powdered activated carbon removes the average particle size for the removal of substances of interest D2 (D2 <D1), the average mixing a material containing a liquid dispersion medium, the A method for producing a modified activated carbon, wherein a powdered activated carbon having the average particle diameter D2 is placed in a macropore of activated carbon having a particle size D1, and a modified activated carbon in which powdered activated carbon is contained in a macropore of the activated carbon is produced.   Mixing a material containing activated carbon larger than a predetermined size with macropores and a liquid dispersion medium, and putting the powdered activated carbon having a predetermined size or less generated from a part of the activated carbon into the macropores, A method for producing modified activated carbon, wherein a step of removing powdered activated carbon having a predetermined size or less that has not entered the macropores is performed to produce modified activated carbon having powdered activated carbon in the macropores of the activated carbon. A filtration cartridge using modified activated carbon in which powdered activated carbon for removing the substance to be removed enters the macropores of the activated carbon.