Activated carbon

Abstract

A problem of the present invention is to provide activated carbon with high mechanical strength and outstanding trihalomethane filtration ability.　Activated carbon in which a pore volume A of pore widths in the range of 1.0 nm or less, from among pore volumes calculated using the QSDFT method from a nitrogen desorption isotherm, is 0.23 cc / g or more and 0.25 cc / g or less, a pore volume B of pore widths in the range of 1.5 nm or more and 2.5 nm or less, from among pore volumes calculated using the QSDFT method from the nitrogen desorption isotherm, is more than 0.12 cc / g and 0.19 cc / g or less, and the specific surface area is ​​1000 m2 / g or more and 1200 m2 / g or less.

Description

activated carbon

[0001] The present invention relates to activated carbon having high mechanical strength and excellent trihalomethane filtering ability.

[0002] Conventionally, chlorine has been added to drinking water for the purpose of sterilization. However, the chlorine contained in tap water reacts with organic matter contained in the water to produce organic halogen compounds. For example, it is known that when humic substances, which are natural organic matter, react with chlorine in tap water, they produce trihalomethanes such as chloroform, which are carcinogenic substances. Therefore, activated carbon with excellent filtering ability for trihalomethanes contained in tap water has been proposed in recent years.

[0003] For example, Patent Document 1 reports that the activated carbon with excellent trihalomethane filtering ability is that the pore volume calculated by QSDFT method is 0.3 cc / g or more for the pore diameter of 1.0 nm or less, and the pore volume calculated by QSDFT method is 0.009 cc / g or more for the pore diameter of 3.0 nm or more to 3.5 nm or less.The activated carbon described in Patent Document 1 can also exhibit excellent trihalomethane filtering ability in the water treatment at high superficial velocity (SV), and has high usefulness.

[0004] International Publication No. 2019 / 244903

[0005] The present inventors have conducted research to further improve the functionality of activated carbon and have found that the activated carbon described in Patent Document 1 has room for further improvement in terms of mechanical strength.

[0006] Therefore, a main object of the present invention is to provide an activated carbon having high mechanical strength and excellent trihalomethane filtering ability.

[0007] The present inventors believed that in order to further improve the mechanical strength of the activated carbon described in Patent Document 1, it is necessary to reduce the pore volume A of pores with diameters of 1.0 nm or less. That is, the activated carbon described in Patent Document 1 has a pore volume A of 0.3 cc / g or more for pores with diameters of 1.0 nm or less, which is an obstacle to further improving the mechanical strength. However, trihalomethanes are thought to be easily adsorbed in pores with diameters of 1.0 nm or less, and simply reducing the pore volume A for such pore diameters will result in a decrease in the trihalomethane filtration ability, making it impossible to achieve both high mechanical strength and excellent trihalomethane filtration ability.

[0008] Therefore, the present inventors have conducted further studies and found that by controlling the pore size, pore volume, and specific surface area of ​​activated carbon, it is possible to achieve both high mechanical strength and excellent trihalomethane filtering ability. Specifically, the present inventors have found that (1) among the pore volumes calculated from the nitrogen desorption isotherm by the QSDFT method, the pore volume A of pores with diameters of 1.0 nm or less is 0.230 cc / g or more and 0.250 cc / g or less, (2) among the pore volumes calculated from the nitrogen desorption isotherm by the QSDFT method, the pore volume B of pores with diameters of 1.5 nm or more and 2.5 nm or less is more than 0.12 cc / g and 0.19 cc / g or less, and (3) the specific surface area is 1000 m 2 / g or more 1200m 2 / g or less can have high mechanical strength and excellent trihalomethane filtering ability. The present invention was completed based on this finding and further investigation.

[0009] That is, the present invention provides the following aspects: Item 1. Among the pore volumes calculated from a nitrogen desorption isotherm by the QSDFT method, the pore volume A of pores with diameters in the range of 1.0 nm or less is 0.230 cc / g or more and 0.250 cc / g or less, among the pore volumes calculated from a nitrogen desorption isotherm by the QSDFT method, the pore volume B of pores with diameters in the range of 1.5 nm or more and 2.5 nm or less is more than 0.120 cc / g and 0.190 cc / g or less, and a specific surface area of ​​1000 m 2 / g or more 1200m 2Item 2. The activated carbon according to Item 1, which is a fibrous activated carbon. Item 3. The activated carbon has a superficial velocity of 3000 h as shown below. -1 Item 3. The activated carbon according to Item 1 or 2, wherein the activated carbon has a chloroform filtration capacity of 40 L / g or more when subjected to a water-passing treatment at a superficial velocity of 3000 h -1 Method for measuring chloroform filtration capacity in water flow treatment> 3.0 g of dried activated carbon was beaten and packed into a glass column (diameter 25 mm) to prepare an activated carbon column (activated carbon packed height 41 mm). Test raw water with a chloroform concentration of 60 ± 12 ppb was prepared, and the water temperature was controlled at 20 ° C ± 1 ° C, and the superficial velocity was 3000 h -1 Water is passed through the activated carbon column at a temperature of 925 to 940°C. The chloroform concentrations of the raw test water and the filtered water are measured by the headspace method using a non-radioactive electron capture detector, and the amount of water passing (L / g) at which the chloroform removal rate reaches 80% is determined as the chloroform filtration capacity. Item 4. The activated carbon according to Item 2, having a tensile strength of 0.15 GPa or more as measured in accordance with "7.3.2 Tensile Strength" of JIS K 1477:2007 "Test Methods for Fibrous Activated Carbon". Item 5. A method for producing the activated carbon according to any one of Items 1 to 4, comprising a step of activating an activated carbon precursor containing 0.1 to 1.0 mass% yttrium at a temperature of 925 to 940°C in an atmosphere having a CO2 concentration of 90% by volume or more. Item 6. A water purification filter comprising the activated carbon according to any one of Items 1 to 4. Item 7. A method for filtering water using the activated carbon according to any one of Items 1 to 4.

[0010] The activated carbon of the present invention has a pore size, pore volume, and specific surface area that fall within the predetermined ranges, thereby providing high mechanical strength and excellent trihalomethane filtration capability. In particular, the activated carbon of the present invention can exhibit excellent trihalomethane filtration capability even when passing water through it at a high superficial velocity, making it suitable for use in removing trihalomethanes from tap water.

[0011] 1 is a graph showing the pore size distribution calculated by the QSDFT method from the nitrogen desorption isotherm of the activated carbon of Example 1. FIG. 2 is a graph showing the pore size distribution calculated by the QSDFT method from the nitrogen desorption isotherm of the activated carbon of Example 2. FIG. 3 is a graph showing the pore size distribution calculated by the QSDFT method from the nitrogen desorption isotherm of the activated carbon of Example 3. FIG. 4 is a graph showing the pore size distribution calculated by the QSDFT method from the nitrogen desorption isotherm of the activated carbon of Comparative Example 1. FIG. 5 is a graph showing the pore size distribution calculated by the QSDFT method from the nitrogen desorption isotherm of the activated carbon of Comparative Example 2. FIG. 6 is a graph showing the pore size distribution calculated by the QSDFT method from the nitrogen desorption isotherm of the activated carbon of Comparative Example 3.

[0012] The activated carbon of the present invention has a pore volume calculated from a nitrogen desorption isotherm by the QSDFT method, in which the pore volume A of pores with diameters of 1.0 nm or less is 0.230 cc / g or more and 0.250 cc / g or less, and the pore volume B of pores with diameters of 1.5 nm or more and 2.5 nm or less is more than 0.12 cc / g and 0.19 cc / g or less, and a specific surface area of ​​1000 m 2 / g or more 1200m 2 The activated carbon of the present invention is characterized in that it has a molecular weight of 1 / g or less. The activated carbon of the present invention will be described in detail below.

[0013] [Pore diameter and pore volume] In the present invention, the pore diameter and pore volume of activated carbon are values ​​calculated by the QSDFT method (quenched solid density functional theory) from a nitrogen desorption isotherm (relative pressure 0.02 to 0.995) measured at a temperature of 77 K. The QSDFT method is an analytical technique that targets pore size analysis of geometrically and chemically irregular microporous and mesoporous carbons and can calculate pore size distributions from about 0.5 nm to about 40 nm. The QSDFT method clearly takes into account the effects of roughness and heterogeneity of the pore surface, and therefore is a technique that significantly improves the accuracy of pore size distribution analysis. In the present invention, the nitrogen desorption isotherm can be measured using a gas adsorption amount measuring device such as "AUTOSORB-1-MP" manufactured by Quantachrome, and the pore size distribution analysis by the QSDFT method can be performed by applying N at 77K on carbon [slit pore, QSDFT equilibrium model] as a calculation model.

[0014] The activated carbon of the present invention has a pore volume A of pores with a diameter of 1.0 nm or less, calculated from the nitrogen desorption isotherm by the QSDFT method, of 0.230 cc / g or more and 0.250 cc / g or less. By making the pore volume A 0.250 cc / g or less, the activated carbon can be provided with high mechanical strength. Furthermore, by making the pore volume A 0.230 cc / g or more, the activated carbon can be provided with excellent trihalomethane filtration capacity, particularly excellent trihalomethane filtration capacity even under high superficial velocity. From the viewpoint of more easily achieving both high mechanical strength and excellent trihalomethane filtration capacity, the pore volume A is preferably 0.230 cc / g or more and 0.245 cc / g or less, more preferably 0.230 cc / g or more and 0.240 cc / g or less, and even more preferably 0.235 cc / g or more and 0.240 cc / g or less.

[0015] The activated carbon of the present invention has a pore volume B of pore diameters in the range of 1.5 nm to 2.5 nm, calculated from the nitrogen desorption isotherm by QSDFT, of which the pore volume B is greater than 0.120 cc / g and less than 0.190 cc / g. By making the pore volume B greater than 0.120 cc / g, it is possible to provide excellent trihalomethane filtration capacity, especially excellent trihalomethane filtration capacity even under high superficial velocity. Furthermore, by making the pore volume B less than 0.19 cc / g, it is possible to easily achieve the above-mentioned pore volume A in the range of 0.230 cc / g or more. According to the findings of the present inventors, pores with a pore diameter in the range of 1.5 nm to 2.5 nm have the function of diffusing trihalomethanes into the pores, but are more likely to adsorb trihalomethanes than pores with a pore diameter in the range of 3.0 nm to 3.5 nm. Therefore, it is believed that the activated carbon of the present invention can exhibit excellent trihalomethane adsorption performance even if the pore volume A of pores with diameters of 1.0 nm or less, which are responsible for trihalomethane adsorption performance, is reduced to 0.250 cc / g or less.

[0016] In the activated carbon of the present invention, from the viewpoint of providing excellent trihalomethane filtration ability, particularly excellent trihalomethane filtration ability even at high superficial velocity, the pore volume B is preferably 0.121 cc / g or more and 0.180 cc / g or less, more preferably 0.145 cc / g or more and 0.175 cc / g or less, even more preferably 0.150 cc / g or more and 0.170 cc / g or less, and particularly preferably 0.153 cc / g or more and 0.169 cc / g or less.

[0017] In the activated carbon of the present invention, the pore volume of pores with a diameter of 0.65 nm or less, calculated from the nitrogen desorption isotherm by the QSDFT method, is not particularly limited as long as the pore volumes A and B satisfy the above-mentioned ranges, and may be, for example, 0.060 cc / g or more and 0.090 cc / g or less, preferably 0.060 cc / g or more and 0.077 cc / g or less, more preferably 0.069 cc / g or more and 0.077 cc / g or less. By satisfying such a range, it becomes easier to more suitably achieve both high mechanical strength and excellent trihalomethane filtration ability.

[0018] In the activated carbon of the present invention, the pore volume of pores with a diameter of 0.8 nm or less, calculated from the nitrogen desorption isotherm by the QSDFT method, is not particularly limited as long as the pore volumes A and B satisfy the above-mentioned ranges, and may be, for example, 0.140 cc / g or more and 0.150 cc / g or less, preferably 0.144 cc / g or more and 0.150 cc / g or less. By satisfying such a range, it becomes easier to more suitably achieve both high mechanical strength and excellent trihalomethane filtration ability.

[0019] In the activated carbon of the present invention, the pore volume of pores with diameters of 1.5 nm or less, among the pore volumes calculated from the nitrogen desorption isotherm by the QSDFT method, is not particularly limited as long as the pore volumes A and B satisfy the above-mentioned ranges, but may be, for example, 0.300 cc / g or more and 0.400 cc / g or less, preferably 0.300 cc / g or more and 0.350 cc / g or less. By satisfying such ranges, it becomes easier to more suitably achieve both high mechanical strength and excellent trihalomethane filtration ability.

[0020] In the activated carbon of the present invention, the pore volume of the pore diameter in the range of 2.0 nm or less among the pore volumes calculated by the QSDFT method from the nitrogen desorption isotherm is not particularly limited, as long as the pore volumes A and B satisfy the above-mentioned ranges, but for example, 0.350 cc / g or more and 0.450 cc / g or less, preferably 0.350 cc / g or more and 0.425 cc / g or less, more preferably 0.380 cc / g or more and 0.425 cc / g or less. By satisfying such ranges, it is easier to more suitably achieve both high mechanical strength and excellent trihalomethane filtration ability.

[0021] In the activated carbon of the present invention, the pore volume of pores having a diameter of 2.5 nm or more among the pore volumes calculated by the QSDFT method from the nitrogen desorption isotherm is not particularly limited as long as the pore volumes A and B satisfy the above-mentioned ranges. For example, the pore volume is 0.200 cc / g or less, preferably 0.030 cc / g or more and 0.180 cc / g or less, and more preferably 0.055 cc / g or more and 0.160 cc / g or less.

[0022] In the activated carbon of the present invention, the pore volume of pores with diameters of 3.5 nm or more, calculated from the nitrogen desorption isotherm by the QSDFT method, is not particularly limited as long as the pore volumes A and B satisfy the above-mentioned ranges, but may be, for example, 0.010 cc / g or less, preferably 0.005 cc / g or less. By satisfying such ranges, the trihalomethane filtration ability can be further improved.

[0023] In the activated carbon of the present invention, the total pore volume calculated from the nitrogen desorption isotherm by the QSDFT method is not particularly limited as long as the pore volumes A and B satisfy the above-mentioned ranges, but may be, for example, 0.400 cc / g or more and 0.800 cc / g or less, preferably 0.450 cc / g or more and 0.700 cc / g or less, more preferably 0.500 cc / g or more and 0.670 cc / g or less. By satisfying such ranges, it becomes easier to more suitably achieve both high mechanical strength and excellent trihalomethane filtration ability.

[0024] [Specific surface area] The activated carbon of the present invention has a specific surface area of ​​1000 m 2 / g or more 1200m 2 / g or less. 2 By making the specific surface area 1200 m / g or more, it is possible to provide excellent trihalomethane filtering ability, particularly excellent trihalomethane filtering ability even under high superficial velocity. 2 By setting the specific surface area of ​​the activated carbon of the present invention to 1000 m / s or less, it is possible to easily achieve the pore volume A of 0.230 cc / g or more. From the viewpoint of further improving the filtering ability of trihalomethanes, particularly the filtering ability of trihalomethanes under high superficial velocity, the specific surface area of ​​the activated carbon of the present invention is preferably 1000 m / s or less. 2 / g or more 1180m 2 / g or less, more preferably 1050m 2 / g or more 1180m 2 / g or less, more preferably 1080m 2 / g or more 1160m 2 In the present invention, the specific surface area of ​​activated carbon is a value determined by the BET method (one-point method in which the measurement point is a relative pressure of 0.1) using nitrogen as an adsorbed substance.

[0025] [Original Raw Material] The raw material from which the activated carbon of the present invention is derived (the main raw material of the activated carbon precursor) is not particularly limited, and examples thereof include plant-based carbonaceous precursors (e.g., plant-derived materials such as bamboo, wood, sawdust, charcoal, fruit shells such as coconut shells and walnut shells, and fruit seeds), mineral-based carbonaceous precursors (e.g., mineral-derived materials such as peat, lignite, brown coal, bituminous coal, anthracite, coke, and coal tar), infusible or carbonized organic materials, and infusible resins such as phenolic resins. Specific examples of the organic materials include polyacrylonitrile, pitch, polyvinyl alcohol, and cellulose. Among these, the activated carbon of the present invention is preferably derived from pitch, and more preferably from coal pitch.

[0026] [Containing Metal Species] In one embodiment of the activated carbon of the present invention, yttrium is contained in the activated carbon. As described below, a suitable method for producing the activated carbon of the present invention includes a step of activating an activated carbon precursor containing an yttrium compound, and the activated carbon obtained by this production method contains yttrium derived from the yttrium compound in the activated carbon precursor. The yttrium contained in one embodiment of the activated carbon of the present invention can be in the form of simple yttrium, an yttrium compound, or a mixture thereof. In one embodiment of the activated carbon of the present invention, the yttrium content is, for example, 0.001 to 1.0 mass%, preferably 0.01 to 0.8 mass%, and more preferably 0.4 to 0.6 mass%. The yttrium content in the activated carbon can be determined by measuring the yttrium content using an energy dispersive X-ray fluorescence analyzer. Furthermore, when the activated carbon of the present invention contains yttrium, the yttrium content can be reduced by washing. Reducing the yttrium content by washing does not affect the mechanical strength and trihalomethane filtration capacity of the activated carbon of the present invention.

[0027] In one embodiment of the activated carbon of the present invention, the activated carbon is substantially free of iron (elemental iron and / or iron compounds). Here, "substantially free of iron" means that the content of elemental iron is below the detection limit when the activated carbon is ashed, the ash is dissolved in acid, and the resultant solution is measured using an ICP atomic emission spectrometer.

[0028] [Form] The form of the activated carbon of the present invention is not particularly limited, and examples thereof include fibrous, granular, powdery, etc. From the viewpoints of processability when processed into a filter and the adsorption rate of trihalomethanes when used in a water purifier, fibrous activated carbon is preferred.

[0029] When the activated carbon of the present invention is fibrous, the average fiber diameter is, for example, 30 μm or less, preferably about 5 to 20 μm, more preferably about 10 to 20 μm, and even more preferably about 12 to 16 μm. In the present invention, the average fiber diameter of the fibrous activated carbon is measured by observing a side view of a single test piece of fibrous activated carbon with an optical microscope and photographing it with a microscope camera system attached to the microscope. The photographed image is imported into image analysis software, and the width of the test piece at any position in the longitudinal direction is measured. This is performed for 50 pieces of fibrous activated carbon, and the average value of the widths of the 50 pieces is taken as the average fiber diameter.

[0030] When the activated carbon of the present invention is in the form of granules or powder, the particle size thereof may be, for example, 0.01 to 5 mm in terms of cumulative volume percentage D50 measured by a laser diffraction / scattering method.

[0031] [Trihalomethane filtration capacity] The activated carbon of the present invention has excellent trihalomethane filtration capacity, particularly excellent trihalomethane filtration capacity even under high superficial velocity, by satisfying the above-mentioned pore volume A, pore volume B, and specific surface area within the specified ranges.

[0032] As an example of the trihalomethane filtering capacity that the activated carbon of the present invention can have, the following superficial velocity of 3000 h -1 The chloroform filtration capacity in the water flow treatment is 40 L / g or more, preferably 40 to 90 L / g, more preferably 40 to 60 L / g, and even more preferably 42 to 45 L / g. -1 Method for measuring chloroform filtration capacity in water flow treatment> 3.0 g of dried activated carbon was beaten and packed into a glass column (diameter 25 mm) to prepare an activated carbon column (activated carbon packed height 41 mm). Test raw water with a chloroform concentration of 60 ± 12 ppb was prepared, and the water temperature was controlled at 20 ° C ± 1 ° C, and the superficial velocity was 3000 h -1Water is passed through the activated carbon column at a rate of 1000 kJ / s. The chloroform concentrations of the raw test water and the filtrate are measured by the headspace method using a non-radioactive electron capture detector, and the amount of water passed (L / g) at which the chloroform removal rate reaches 80% is determined as the chloroform filtration capacity. The chloroform removal rate (%) is calculated according to the following formula. The amount of water passed at which the chloroform removal rate reaches 80% is the total amount of filtrate that has flowed out of the activated carbon column and been recovered up to the point at which the chloroform removal rate drops to 80%. Details of the method for measuring chloroform filtration capacity are as described in the Examples section.

[0033] [Mechanical Strength] The activated carbon of the present invention can have high mechanical strength by satisfying the above-mentioned pore volume A, pore volume B, and specific surface area within the predetermined ranges.

[0034] When the activated carbon of the present invention is a fibrous activated carbon, an example of the mechanical strength that the activated carbon may have is a tensile strength of 0.15 GPa or more, preferably 0.15 to 0.40 GPa, and more preferably 0.16 to 0.25 GPa. In the present invention, the tensile strength of the fibrous activated carbon is a value measured in accordance with "7.3.2 Tensile Strength" of Japanese Industrial Standards JIS K 1477:2007 "Test Methods for Activated Carbon Fibre." Specific measurement conditions are as described in the Examples section.

[0035] [Uses] The use of the activated carbon of the present invention is not particularly limited, but it is preferably used for water purification. In particular, since the activated carbon of the present invention has excellent trihalomethane filtration ability, it is suitably used as a water purification filter for removing trihalomethanes from liquids that contain trihalomethanes or liquids that may contain trihalomethanes.

[0036] When the activated carbon of the present invention is used as a water purification filter, it can be molded into a desired shape as needed. For example, when used as a water purification filter for a water purifier, it is preferably cylindrical, and if necessary, a cap may be attached to the top of the cylindrical tube, or the surface may be covered with a nonwoven fabric. Furthermore, when the activated carbon of the present invention is used as a water purification filter, the activated carbon of the present invention can be provided as a cartridge by filling it into a housing either as is or after molding it into a desired shape.

[0037] The trihalomethane to be removed by the activated carbon of the present invention may be at least one of chloroform, bromodichloromethane, dibromochloromethane, and bromoform, but is preferably chloroform.

[0038] Furthermore, the liquid to be treated by the activated carbon of the present invention may be any liquid that contains trihalomethanes or that may contain trihalomethanes, and examples thereof include tap water and industrial water, preferably tap water.

[0039] Furthermore, the activated carbon of the present invention has excellent trihalomethane filtering ability even under high superficial velocity, and therefore can be suitably used as a water purification filter for water treatment (filtration treatment) under high superficial velocity. It goes without saying that it can also be used as a water purification filter for water treatment under low superficial velocity, not just under high superficial velocity. The superficial velocity during water treatment applicable to the activated carbon of the present invention is, for example, 500 h -1 or more, preferably 1000 to 4000 h -1 When the activated carbon of the present invention is used for water treatment at a high superficial velocity, the applied high superficial velocity is preferably 2000 to 4000 h -1 , more preferably 2000 to 3500 h -1 Examples include:

[0040] [Production Method] The method for producing the activated carbon of the present invention is not particularly limited as long as it can produce activated carbon having the aforementioned pore volume A, pore volume B, and specific surface area within the specified ranges, but a suitable example is a production method including a step of activating an activated carbon precursor containing 0.1 to 1.0 mass % of yttrium at a temperature of 925 to 940°C in an atmosphere with a CO concentration of 90% by volume or more. Hereinafter, this production method will be referred to as the "production method for the activated carbon of the present invention" and will be described in detail.

[0041] In the method for producing activated carbon of the present invention, an activated carbon precursor containing 0.1 to 1.0 mass % of yttrium is activated at 925 to 940°C using an activation gas containing 90 vol % or more of CO, which reacts more slowly than water vapor, making it possible to obtain activated carbon having the above-mentioned pore volume A, pore volume B, and specific surface area that fall within the specified ranges.

[0042] In the method for producing activated carbon of the present invention, the main raw material for the activated carbon precursor is not particularly limited, but examples thereof include infusible or carbonized organic materials, infusible resins such as phenolic resins, etc. Examples of the organic materials include polyacrylonitrile, pitch, polyvinyl alcohol, cellulose, etc. Among these main raw materials, pitch is preferred in terms of the theoretical carbonization yield during carbonization, and among pitches, coal pitch is particularly preferred.

[0043] The yttrium contained in the activated carbon precursor may be yttrium alone, an yttrium compound, or a mixture thereof, but is preferably an yttrium compound.

[0044] Examples of yttrium compounds include inorganic yttrium compounds such as yttrium oxide, yttrium hydroxide, yttrium halide, and yttrium sulfate; organic yttrium acid salts such as yttrium acetate; and organic yttrium compounds. Among these yttrium compounds, organic yttrium compounds are preferred from the viewpoint of increasing the dispersibility of the yttrium compound in the activated carbon precursor and making it easier for the obtained activated carbon to satisfy the aforementioned pore volume A, pore volume B, and specific surface area within suitable ranges. A suitable example of an organic yttrium compound is an yttrium complex having a β-diketone compound as a ligand. Examples of β-diketone compounds include those having the structures shown in the following formulas (1) to (3).

[0045]

[0046] In the formula (1), R 12 and R 13 are the same or different and represent an alkyl group having 1 to 22 carbon atoms or an alkenyl group having 1 to 22 carbon atoms, preferably an alkyl group having 1 to 11 carbon atoms or an alkenyl group having 1 to 11 carbon atoms, more preferably an alkyl group having 1 to 8 carbon atoms, and even more preferably a methyl group. 11 represents a hydrogen atom, an alkyl group having 1 to 22 carbon atoms or an alkenyl group having 1 to 22 carbon atoms, preferably a hydrogen atom, an alkyl group having 1 to 11 carbon atoms or an alkenyl group having 1 to 11 carbon atoms, more preferably a hydrogen atom.

[0047] In the formula (2), R 21 represents a hydrogen atom, an alkyl group having 1 to 22 carbon atoms, or an alkenyl group having 1 to 22 carbon atoms, preferably a hydrogen atom, an alkyl group having 1 to 11 carbon atoms, or an alkenyl group having 1 to 11 carbon atoms, more preferably a hydrogen atom. 22 represents a hydrogen atom, an alkyl group having 1 to 22 carbon atoms, or an alkenyl group having 1 to 22 carbon atoms, preferably a hydrogen atom, an alkyl group having 1 to 11 carbon atoms, or an alkenyl group having 1 to 11 carbon atoms, more preferably a hydrogen atom. 23represents an alkyl group having 1 to 22 carbon atoms or an alkenyl group having 1 to 22 carbon atoms, preferably an alkyl group having 1 to 11 carbon atoms or an alkenyl group having 1 to 11 carbon atoms, more preferably an alkyl group having 1 to 8 carbon atoms, and even more preferably a methyl group.

[0048] In the formula (3), R 31 and R 33 are the same or different and represent a hydrogen atom, an alkyl group having 1 to 22 carbon atoms, or an alkenyl group having 1 to 22 carbon atoms, preferably a hydrogen atom, an alkyl group having 1 to 11 carbon atoms, or an alkenyl group having 1 to 11 carbon atoms, more preferably a hydrogen atom. 32 represents a hydrogen atom, an alkyl group having 1 to 22 carbon atoms or an alkenyl group having 1 to 22 carbon atoms, preferably a hydrogen atom, an alkyl group having 1 to 11 carbon atoms or an alkenyl group having 1 to 11 carbon atoms, more preferably a hydrogen atom.

[0049] Among the yttrium complexes having a β-diketone type compound as a ligand, the yttrium complex having a β-diketone type compound represented by the formula (1) as a ligand is preferred, and more preferred is trisacetylacetonatoyttrium [acetylacetone (R 11 and R 13 is a methyl group, R 12 and a compound in which three molecules of the yttrium complex are coordinated.

[0050] In the method for producing activated carbon of the present invention, the yttrium content in the activated carbon precursor may be 0.1 to 1.0 mass%, preferably 0.15 to 1.0 mass%, more preferably 0.15 to 0.5 mass%, and even more preferably 0.20 to 0.25 mass%. The yttrium content in the activated carbon precursor is the amount of yttrium element measured using an energy dispersive X-ray fluorescence analyzer.

[0051] In the production method of the present invention, the CO concentration in the activation atmosphere may be 90% by volume or more, preferably 95% by volume or more, and more preferably 99% by volume or more. As described above, when CO is used as the activation gas, the reaction proceeds slowly, and therefore, the higher the CO concentration, the easier it is to adjust the pore size distribution, making it easier to obtain the activated carbon of the present invention.

[0052] In the activation atmosphere, components other than CO2 include N2, O2, H2, H2O, and CO.

[0053] In the method for producing activated carbon of the present invention, the activation atmosphere temperature may be 925 to 940° C., preferably 928 to 938° C., and more preferably 930 to 935° C. By using an activated carbon precursor containing 0.1 to 1.0 mass % of yttrium and setting the activation temperature within the above range in an atmosphere with a CO concentration of 90% by volume or more, it is possible to obtain activated carbon whose pore volume A, pore volume B, and specific surface area fall within the predetermined ranges.

[0054] The activation time may be adjusted to achieve a predetermined pore size distribution and specific surface area depending on the main raw material of the activated carbon precursor, the content of the yttrium compound, the CO concentration in the activation gas, etc. For example, when pitch having a softening point of 275°C to 288°C is used as the main raw material of the activated carbon precursor, the content of the yttrium compound in the activated carbon precursor is 0.1 to 1.0 parts by mass, and the CO concentration is 100% by volume, activation can be performed at an atmospheric temperature of 925 to 940°C for 30 to 50 minutes.

[0055] The activated carbon obtained after activation may be subjected to a washing treatment using an acid such as sulfuric acid, if necessary. By performing the washing treatment, the yttrium content in the activated carbon can be reduced without adversely affecting the mechanical strength and trihalomethane filtering ability.

[0056] The present invention will be described in detail below with reference to examples and comparative examples, but the present invention should not be construed as being limited to these examples.

[0057] 1. Test Methods (1) Yttrium Content (% by Mass) of Activated Carbon Precursor (Stabilized Pitch Fiber) Pitch fiber was pulverized, and the proportion of yttrium converted into elemental yttrium measured using an energy dispersive X-ray fluorescence analyzer (NEX DE manufactured by Rigaku Corporation) was determined as the yttrium content.

[0058] (2) Iron Content (% by mass) of Activated Carbon Precursor (Infusibilized Pitch Fiber) Pitch fiber was incinerated, and the ash was dissolved in acid. The iron content was determined as the proportion of elemental iron measured using an ICP optical emission spectrometer (Model 715-ES, manufactured by Varian).

[0059] (3) Yttrium Content (% by mass) of Activated Carbon Fibrous activated carbon was pulverized, and the proportion of yttrium converted into elemental yttrium measured using an energy dispersive X-ray fluorescence analyzer (NEX DE manufactured by Rigaku Corporation) was determined as the yttrium content.

[0060] (4) Iron Content (% by mass) of Activated Carbon Fibrous activated carbon was ashed, and the ash was dissolved in acid. The iron content was determined as the proportion of elemental iron measured using an ICP optical emission spectrometer (Model 715-ES, manufactured by Varian).

[0061] (5) Pore volume (cc / g) and specific surface area (m 2 / g) Pore properties were measured from a nitrogen adsorption isotherm at 77K (relative pressure 0.02 to 0.995) using Quantachrome's "AUTOSORB-1-MP." The specific surface area was calculated from the measurement point of a relative pressure of 0.1 by the BET method. The total pore volume and the pore volume in each pore size range listed in Table 1 were analyzed by calculating the pore size distribution by applying N2 at 77K on carbon [slit pore, QSDFT equilibrium model] as a calculation model to the measured nitrogen desorption isotherm. Specifically, the pore volume in each pore size range listed in Table 1 is the read value of the graph showing the pore size distribution shown in Figures 1 to 6 or a value calculated from the read value. More specifically, the pore volume having a pore diameter of 0.65 nm or less is the reading of the cumulative pore volume (cc / g) when the horizontal axis Pore Width of the pore diameter distribution diagram is 0.65 nm. Similarly, the pore volume having a pore diameter of 0.8 nm or less, the pore volume A having a pore diameter of 1.0 nm or less, the pore volume of a pore diameter of 1.5 nm or less, the pore volume of a pore diameter of 2.0 nm or less, the pore volume of a pore diameter of 2.5 nm or less, the pore volume of a pore diameter of 3.0 nm or less, and the pore volume of a pore diameter of 3.5 nm or less were obtained. The pore volume B in the pore diameter range of 1.5 nm to 2.5 nm was calculated by subtracting the pore volume of the pore diameter of 1.5 nm or less from the pore volume of the pore diameter of 2.5 nm or less. The total pore volume was calculated by subtracting the pore volume obtained by the QSDFT method. The pore volume having a pore diameter of 2.0 nm or more was calculated by subtracting the pore volume having a pore diameter of 2.0 nm or less from the total pore volume obtained by the QSDFT method. The pore volume having a pore diameter of 2.5 nm or more was calculated by subtracting the pore volume having a pore diameter of 2.5 nm or less from the total pore volume obtained by the QSDFT method. The pore volume having a pore diameter of 3.5 nm or more was calculated by subtracting the pore volume having a pore diameter of 3.5 nm or less from the total pore volume obtained by the QSDFT method. The pore volume of pores having a diameter in the range of 1.0 nm to 1.5 nm was calculated by subtracting the pore volume A having a pore diameter of 1.0 nm or less from the pore volume having a pore diameter of 1.5 nm or less.The pore volume of pores having a diameter of 1.0 nm or more and 2.0 nm or less was calculated by subtracting the pore volume A of pores having a diameter of 1.0 nm or less from the pore volume of pores having a diameter of 2.0 nm or less. The pore volume of pores having a diameter of 0.65 nm or more and 0.8 nm or less was calculated by subtracting the pore volume of pores having a diameter of 0.65 nm or less from the pore volume of pores having a diameter of 0.8 nm or less. The pore volume of pores having a diameter of 0.65 nm or more and 1.0 nm or less was calculated by subtracting the pore volume of pores having a diameter of 0.65 nm or less from the pore volume A of pores having a diameter of 1.0 nm or less. The pore volume of pores having a diameter of 0.8 nm or less was calculated by subtracting the pore volume of pores having a diameter of 0.8 nm or less from the pore volume of pores having a diameter of 1.5 nm or less. The pore volume of pores with diameters in the range of 2.0 nm or more and 3.0 nm or less was calculated by subtracting the pore volume of pores with diameters of 2.0 nm or less from the pore volume of pores with diameters of 3.0 nm or less.

[0062] (6) Fiber diameter (μm) of fibrous activated carbon The side view of one test piece of fibrous activated carbon was observed under a magnification of 40 times with an optical microscope (Nikon ECLIPSE E600) and photographed with a microscope camera system (Motic Moticam Pro 252A) (512 × 384) attached to the microscope. The photographed image was imported into image analysis software (Image-Pro Plus), and the width at any position in the longitudinal direction of the test piece was measured. This was performed on 50 pieces of fibrous activated carbon, and the average value of the widths of the 50 pieces was taken as the average fiber diameter.

[0063] (7) Chloroform filtration capacity (L / g) After drying the fibrous activated carbon in a dryer at 105 ° C for more than 2 hours, 3.0 g was collected, beaten in a mixer, and then packed into a glass column (diameter 25 mm) to prepare an activated carbon column (activated carbon packed height 41 mm). Test raw water with a chloroform concentration of 60 ± 12 ppb was prepared based on the method specified in "6.4.4.1 Individual Test" of JIS S 3201:2019 "Test Method for Household Water Purifiers," and the water temperature was controlled at 20 ° C ± 1 ° C, and the superficial velocity was 3000 h -1The test water was passed through the activated carbon column at 4000 kJ / g. The chloroform concentrations in the raw test water and filtrate were measured by the headspace method using a non-radioactive electron capture detector (GC7000EN, manufactured by J Science Lab Co., Ltd.). The raw test water was passed continuously until the chloroform removal rate of the filtrate fell below 80%, and the amount of water passing (L / g) at which the chloroform removal rate reached 80% was defined as the chloroform filtration capacity of the activated carbon. A water passing rate of 40 L / g or more at which the chloroform removal rate reached 80% can be evaluated as having excellent chloroform filtration capacity. The chloroform removal rate (%) was calculated according to the following formula. The amount of water passing at which the chloroform removal rate reached 80% is the total amount of filtrate that had flowed out of the activated carbon column and been recovered up to the point at which the chloroform removal rate fell to 80%.

[0064] (8) Tensile Strength (GPa) of Fibrous Activated Carbon The tensile strength was measured in accordance with "7.3.2 Tensile Strength" of JIS K 1477:2007 "Test Methods for Fibrous Activated Carbon" using a tensile tester (trade name: SIMADZU EZ-SX) manufactured by Shimadzu Corporation as a measuring instrument. Specifically, first, both ends of one piece of fibrous activated carbon were fixed to a test mount to prepare a test piece. The test piece was attached to the tensile tester, and the test mount for the test piece was cut to conduct a tensile test on the fibrous activated carbon. The tensile test was performed with the test piece length set to 10.0±0.2 mm and the pulling speed set to 1 mm / min. The force (N) applied when cutting the fibrous activated carbon was calculated based on the average fiber diameter described above, and then multiplied by the fiber cross-sectional area (mm 2 ) and convert the unit to GPa (1 GPa = 1000 N / mm 2 When the tensile strength of the fibrous activated carbon is 0.15 GPa or more, it can be evaluated as having high mechanical strength.

[0065] 2. Production and Evaluation of Fibrous Activated Carbon Example 1 A mixture of 100 parts by mass of granular coal pitch with a softening point of 280°C and 1.0 part by mass of yttrium trisacetylacetonate (CAS number: 15554-47-9) was fed to a melt extruder and melt-mixed at a melting temperature of 325°C to obtain pitch fiber by spinning. The obtained pitch fiber was subjected to a stabilization treatment by increasing the temperature in air from room temperature to 360°C at a rate of 1 to 30°C / min for 70 minutes, to obtain an activated carbon precursor that was a stabilized pitch fiber. The activated carbon precursor had an yttrium content of 0.228% by mass and an iron content of 0% by mass.

[0066] The obtained activated carbon precursor was activated by continuously introducing a gas having a CO2 concentration of 100% by volume into an activation furnace and heat treating it at an atmospheric temperature of 935°C for 40 minutes, to obtain fibrous activated carbon.

[0067] The metal content, pore volume, specific surface area, fiber diameter of the fibrous activated carbon, chloroform filtration capacity, and tensile strength of the obtained activated carbon were measured, and the results are shown in Table 1. The obtained activated carbon had a pore volume A of 0.238 cc / g for pore diameters of 1.0 nm or less, a pore volume B of 0.169 cc / g for pore diameters of 1.5 nm to 2.5 nm, and a specific surface area of ​​1151 m. 2 / g, yttrium content 0.57 mass%, iron content 0 mass%, average fiber diameter 14.0 μm. Furthermore, the obtained activated carbon was washed with sulfuric acid. The yttrium content of the activated carbon after washing was 0.038 mass%. Furthermore, the pore volume, specific surface area, fiber diameter of the fibrous activated carbon, chloroform filtration capacity, and tensile strength of the activated carbon after washing were unchanged from before washing.

[0068] Example 2: As an organic material, 100 parts by mass of granular coal pitch having a softening point of 280°C was mixed with 1.0 part by mass of yttrium trisacetylacetonate (CAS number: 15554-47-9). This mixture was fed into a melt extruder, melt-mixed at a melting temperature of 325°C, and spun to obtain pitch fiber. The obtained pitch fiber was subjected to a stabilization treatment by increasing the temperature in air from room temperature to 360°C at a rate of 1 to 30°C / min for 70 minutes, to obtain an activated carbon precursor, which is a stabilized pitch fiber. The yttrium content of this activated carbon precursor was 0.228% by mass. The iron content was 0% by mass.

[0069] The obtained activated carbon precursor was activated by continuously introducing a gas having a CO2 concentration of 100% by volume into an activation furnace and heat treating it at an atmospheric temperature of 930°C for 40 minutes, to obtain fibrous activated carbon.

[0070] The activated carbon obtained was measured for its metal content, pore volume, specific surface area, fiber diameter of the fibrous activated carbon, chloroform filtration capacity, and tensile strength, and the results are shown in Table 1. The activated carbon obtained had a pore volume A of 0.240 cc / g for pore diameters of 1.0 nm or less, a pore volume B of 0.153 cc / g for pore diameters of 1.5 nm to 2.5 nm, and a specific surface area of ​​1097 m. 2 / g, the yttrium content was 0.53 mass%, the iron content was 0 mass%, and the average fiber diameter was 14.0 μm. Furthermore, the obtained activated carbon was washed with sulfuric acid. The yttrium content of the activated carbon after washing was 0.038 mass%. Furthermore, the pore volume, specific surface area, fiber diameter of the fibrous activated carbon, chloroform filtration capacity, and tensile strength of the activated carbon after washing were unchanged from before washing.

[0071] Example 3: As an organic material, 100 parts by mass of granular coal pitch having a softening point of 280°C was mixed with 1.0 part by mass of yttrium trisacetylacetonate (CAS number: 15554-47-9). This mixture was fed into a melt extruder, melt-mixed at a melting temperature of 325°C, and spun to obtain pitch fiber. The obtained pitch fiber was subjected to a stabilization treatment by increasing the temperature in air from room temperature to 360°C at a rate of 1 to 30°C / min for 70 minutes, to obtain an activated carbon precursor, which is a stabilized pitch fiber. The yttrium content of this activated carbon precursor was 0.232% by mass. The iron content was 0% by mass.

[0072] The obtained activated carbon precursor was activated by continuously introducing a gas having a CO2 concentration of 100% by volume into an activation furnace and heat treating it at an atmospheric temperature of 930°C for 40 minutes, to obtain fibrous activated carbon.

[0073] The activated carbon obtained was subjected to measurements of the metal content, pore volume, specific surface area, fiber diameter of the fibrous activated carbon, chloroform filtration capacity, and tensile strength, and the results are shown in Table 1. The activated carbon obtained had a pore volume A of 0.239 cc / g for pore diameters of 1.0 nm or less, a pore volume B of 0.122 cc / g for pore diameters of 1.5 nm to 2.5 nm, and a specific surface area of ​​1005 m. 2 / g, the yttrium content was 0.44 mass%, the iron content was 0 mass%, and the average fiber diameter was 14.6 μm. Furthermore, the obtained activated carbon was washed with sulfuric acid. The yttrium content of the activated carbon after washing was 0.038 mass%. Furthermore, the pore volume, specific surface area, fiber diameter of the fibrous activated carbon, chloroform filtration capacity, and tensile strength of the activated carbon after washing were unchanged from before washing.

[0074] Comparative Example 1: As an organic material, 100 parts by mass of granular coal pitch having a softening point of 280°C was mixed with 1.3 parts by mass of yttrium trisacetylacetonate (CAS number: 15554-47-9). This mixture was fed into a melt extruder, melt mixed at a melting temperature of 325°C, and spun to obtain pitch fiber. The obtained pitch fiber was subjected to a stabilization treatment by increasing the temperature in air from room temperature to 370°C at a rate of 1 to 30°C / min for 60 minutes, to obtain an activated carbon precursor, which is a stabilized pitch fiber. The yttrium content of this activated carbon precursor was 0.285% by mass. The iron content was 0% by mass.

[0075] The obtained activated carbon precursor was activated by continuously introducing a gas having an H2O concentration of 100% by volume into an activation furnace and heat treating it at an atmospheric temperature of 896°C for 32 minutes, to obtain fibrous activated carbon.

[0076] The metal content, pore volume, specific surface area, fiber diameter of the fibrous activated carbon, chloroform filtration capacity, and tensile strength of the obtained activated carbon were measured, and the results are shown in Table 1. The obtained activated carbon had a pore volume A of 0.212 cc / g for pore diameters of 1.0 nm or less, a pore volume B of 0.124 cc / g for pore diameters of 1.5 nm to 2.5 nm, and a specific surface area of ​​993 m 2 / g, the yttrium content was 0.59 mass%, the iron content was 0 mass%, and the average fiber diameter was 17.4 μm. Furthermore, the obtained activated carbon was washed with sulfuric acid. The yttrium content of the activated carbon after washing was 0.038 mass%. Furthermore, the pore volume, specific surface area, fiber diameter of the fibrous activated carbon, chloroform filtration capacity, and tensile strength of the activated carbon after washing were unchanged from before washing.

[0077] Comparative Example 2: As an organic material, 100 parts by mass of granular coal pitch having a softening point of 280°C was mixed with 1.0 part by mass of yttrium trisacetylacetonate (CAS number: 15554-47-9). This mixture was fed into a melt extruder, melt mixed at a melting temperature of 325°C, and spun to obtain pitch fiber. The obtained pitch fiber was subjected to a stabilization treatment by increasing the temperature in air from room temperature to 360°C at a rate of 1 to 30°C / min for 70 minutes, to obtain an activated carbon precursor, which is a stabilized pitch fiber. The yttrium content of this activated carbon precursor was 0.234% by mass. The iron content was 0% by mass.

[0078] The obtained activated carbon precursor was activated by continuously introducing a gas having a CO2 concentration of 100% by volume into an activation furnace and heat treating it at an atmospheric temperature of 915°C for 40 minutes, to obtain fibrous activated carbon.

[0079] The activated carbon obtained was measured for its metal content, pore volume, specific surface area, fiber diameter of the fibrous activated carbon, chloroform filtration capacity, and tensile strength, and the results are shown in Table 1. The activated carbon obtained had a pore volume A of 0.239 cc / g for pore diameters of 1.0 nm or less, a pore volume B of 0.112 cc / g for pore diameters of 1.5 nm to 2.5 nm, and a specific surface area of ​​960 m 2 / g, the yttrium content was 0.45 mass%, the iron content was 0 mass%, and the average fiber diameter was 14.0 μm. Furthermore, the obtained activated carbon was washed with sulfuric acid. The yttrium content of the activated carbon after washing was 0.038 mass%. Furthermore, the pore volume, specific surface area, fiber diameter of the fibrous activated carbon, chloroform filtration capacity, and tensile strength of the activated carbon after washing were unchanged from before washing.

[0080] Comparative Example 3: As an organic material, 100 parts by mass of granular coal pitch having a softening point of 280°C was mixed with 0.9 parts by mass of tris(2,4-pentanedionato)iron(III) (metal species: Fe), and the mixture was supplied to a melt extruder, melt-mixed at a melting temperature of 320°C, and spun to obtain pitch fiber. The obtained pitch fiber was subjected to a stabilization treatment by increasing the temperature in air from room temperature to 354°C at a rate of 1 to 30°C / min for 54 minutes, to obtain an activated carbon precursor that was a stabilized pitch fiber. The activated carbon precursor had an iron (Fe) content of 0.110% by mass.

[0081] The obtained activated carbon precursor was activated by continuously introducing a gas having a CO2 concentration of 100% by volume into an activation furnace and heat treating it at an atmospheric temperature of 950°C for 25 minutes, to obtain fibrous activated carbon.

[0082] The metal content, pore volume, specific surface area, fiber diameter of the fibrous activated carbon, chloroform filtration capacity, and tensile strength of the obtained activated carbon were measured, and the results are shown in Table 1. The obtained activated carbon had a pore volume A of 0.350 cc / g for pore diameters of 1.0 nm or less, a pore volume B of 0.002 cc / g for pore diameters of 1.5 nm to 2.5 nm, and a specific surface area of ​​988 m 2 / g, the yttrium content was 0 mass%, the iron content was 0.18 mass%, and the average fiber diameter was 13.9 μm. Furthermore, the obtained activated carbon was washed with sulfuric acid. The iron content of the activated carbon after washing was 0.038 mass%. Furthermore, the pore volume, specific surface area, fiber diameter of the fibrous activated carbon, chloroform filtration capacity, and tensile strength of the activated carbon after washing were unchanged from before washing.

[0083] 3. Summary of Evaluation Results The physical properties of each of the obtained fibrous activated carbons are shown in Table 1. In addition, Figures 1 to 6 show the pore size distribution diagrams calculated by the QSDFT method for each activated carbon.

[0084]

[0085] The activated carbons of Examples 1 to 3 have a tensile strength of 0.15 GPa or more, and have high mechanical strength. -1The activated carbons of Examples 1 to 3 had excellent chloroform filtration capacity at high superficial velocities (the amount of water passing through when the chloroform removal rate reached 80%) of 40 L / g or more, and exhibited excellent chloroform filtration capacity at high superficial velocities. From the physical property values, tensile strength, and chloroform filtration capacity satisfied by the activated carbons of Examples 1 to 3, it was found that (1) the pore volume A of pores with diameters of 1.0 nm or less calculated by the SDFT method was 0.23 cc / g or more and 0.25 cc / g or less, (2) the pore volume B of pores with diameters of 1.5 nm or more and 2.5 nm or less calculated by the QSDFT method was more than 0.12 cc / g and 0.19 cc / g or less, and (3) the specific surface area was 1000 m 2 / g or more 1200m 2 / g or less, it was found that both high mechanical strength and excellent chloroform filtering ability could be achieved.

[0086] On the other hand, the activated carbon of Comparative Example 1 has a pore volume A of pores with diameters of 1.0 nm or less of less than 0.23 cc / g, and a specific surface area of ​​1000 m 2 / g, the filtration capacity of chloroform at high superficial velocities was poor.

[0087] The activated carbon of Comparative Example 2 has a pore volume B of pores with diameters in the range of 1.5 nm to 2.5 nm of less than 0.12 cc / g, and a specific surface area of ​​1000 m 2 / g, the filtration capacity of chloroform at high superficial velocities was poor.

[0088] The activated carbon of Comparative Example 3 had poor mechanical strength because the pore volume A of pores with diameters of 1.0 nm or less exceeded 0.25 cc / g.

Claims

1. Among the pore volumes calculated by the QSDFT method from the nitrogen desorption isotherm, the pore volume A with a pore diameter in the range of 1.0 nm or less is 0.230 cc / g or more and 0.245 cc / g or less, Among the pore volumes calculated by the QSDFT method from the nitrogen desorption isotherm, the pore volume B with a pore diameter in the range of 1.5 nm or more and 2.5 nm or less exceeds 0.120 cc / g and is 0.190 cc / g or less, Specific surface area is 1000 m 2 / g or more and 1200 m 2 / g or less, activated carbon.

2. Among the pore volumes calculated by the QSDFT method from the nitrogen desorption isotherm, the pore volume A with a pore diameter in the range of 1.0 nm or less is 0.230 cc / g or more and 0.250 cc / g or less, Among the pore volumes calculated by the QSDFT method from the nitrogen desorption isotherm, the pore volume B with a pore diameter in the range of 1.5 nm or more and 2.5 nm or less exceeds 0.120 cc / g and is 0.190 cc / g or less, Among the pore volumes calculated by the QSDFT method from the nitrogen desorption isotherm, the pore volume with a pore diameter in the range of 1.5 nm or less is 0.300 cc / g or more and 0.340 cc / g or less, Activated carbon having a specific surface area of 1000 m² / g or more and 1200 m² / g or less.

3. The activated carbon according to Claim 1 or 2, which is fibrous activated carbon.

4. The superficial velocity shown below is 3000 h -1 The activated carbon according to claim 1 or 2, wherein the chloroform filtration capacity in the water passing treatment is 40 L / g or more. <Measurement method of chloroform filtration capacity in water flow treatment at an empty tower velocity of 3000 h -1 > 3.0 g of the dried activated carbon is beaten and packed into a glass column (diameter 25 mm) to prepare an activated carbon column (the packed height of the activated carbon is 41 mm). Test raw water with a chloroform concentration of 60 ± 12 ppb is prepared, the water temperature is controlled at 20°C ± 1°C, and the empty tower velocity is 3000 h -1 and water is passed through the activated carbon column. The chloroform concentrations of the test raw water and the filtered water are measured by the headspace method using a non-radiation source type electron capture detector, and the water flow rate (L / g) at the time when the chloroform removal rate reaches 80% is determined as the chloroform filtration capacity.

5. The activated carbon according to Claim 3, wherein the tensile strength measured in accordance with "7.3.2 Tensile Strength" of JIS K 1477:2007 "Test Method for Fibrous Activated Carbon" is 0.15 GPa or more.

6. Among the pore volumes calculated by the QSDFT method from the nitrogen desorption isotherm, the pore volume A with a pore diameter in the range of 1.0 nm or less is 0.230 cc / g or more and 0.250 cc / g or less, Among the pore volumes calculated by the QSDFT method from the nitrogen desorption isotherm, the pore volume B with a pore diameter in the range of 1.5 nm or more and 2.5 nm or less exceeds 0.120 cc / g and is 0.190 cc / g or less, A method for producing activated carbon, having a specific surface area of 1000 m² / g or more and 1200 m² / g or less, A method for producing the activated carbon, comprising a step of activating an activated carbon precursor containing 0.1 to 1.0% by mass of yttrium in an atmosphere with a CO 2 concentration of 90% by volume or more at a temperature of 925 to 940 °C.

7. A water purification filter containing the activated carbon according to Claim 1 or 2.

8. A method for filtering water, using the activated carbon according to Claim 1 or 2.