Carbonaceous material and method for producing same, sorption filter, water purifier cartridge, water purifier, and water purification facility

Abstract

A carbonaceous material according to the present invention has a pore volume of 0.16 cm3 / g or more and 0.30 cm3 / g or less with a pore diameter of 0.70 nm or less as calculated by a QSDFT method per 1 g of a carbonaceous material from a nitrogen sorption isotherm, a iodine sorption amount of 750 mg / g or more and 1,340 mg / g or less, a reactive black 5 of 6.0 g / L or more and 30.0 g / L or less, and a specific surface area determined by the BET method from a, sorption isotherm of N2 at -196°C of 610 m2 / g or more and 1,400 m2 / g or less.

Description

Carbonaceous material and its manufacturing method, adsorption filter, water purifier cartridge, water purifier, and water purification equipment

[0001] The present invention relates to a carbonaceous material and a method for producing the same, an adsorption filter, a water purifier cartridge, a water purifier, and a water purification facility.

[0002] Household water purifiers are widely used to remove harmful substances from tap water. Among these harmful substances, volatile organic compounds such as trihalomethanes, including chloroform, which are present in trace amounts in tap water, and harmful substances such as musty odors, typified by 2-methylisoborneol (2-MIB), are designated as substances to be removed by household water purifiers under the Household Products Quality Labeling Act, and it is desirable to remove them from tap water.

[0003] To remove such harmful substances, carbonaceous materials are usually used in household water purifiers. For example, Patent Document 1 discloses a carbonaceous material having a benzene adsorption capacity of 25% to 40%, a vitamin B12 adsorption capacity of 13.0 mg / g to 50.0 mg / g, and a mesopore volume of 0.070 cm3 calculated by the BJH method from a nitrogen adsorption isotherm. 3 / g or more 0.150cm 3 / g or less.

[0004] International Publication No. 2020 / 218370

[0005] However, the carbonaceous material described in Patent Document 1 has a pore volume and specific surface area designed to be able to remove substances such as 2-MIB, which have a relatively large molecular size, rather than trihalomethanes such as chloroform, which have a relatively small molecular size. Therefore, although the filtration capacity value for 2-MIB and the like is high, it is difficult to use the carbonaceous material to remove substances such as trihalomethanes, which have a relatively small molecular size, and it is extremely difficult to remove chloroform, which has an even smaller molecular size than trihalomethanes.

[0006] Furthermore, in 2019, the JIS test method for home water purifiers was revised, and the new JIS S3201:2019 added five new substances to the list of substances to be removed. This has led to a demand for home water purifiers that can remove a wider variety of harmful substances than before.

[0007] Of the five new types, the anionic surfactants have larger molecular sizes than 2-MIB. As described in Patent Document 1, the pore volume and specific surface area of ​​carbonaceous materials used in conventional household water purifiers are designed to be suitable for removing molecules of about 2-MIB size. Therefore, it is difficult for conventional carbonaceous materials to remove harmful substances with larger molecular sizes, such as anionic surfactants.

[0008] Since the revision of the JIS test method, carbonaceous materials used in household water purifiers have been required to be able to remove a wide range of harmful substances, from chloroform and the like, which have relatively small molecular sizes, to anionic surfactants and the like, which have relatively large molecular sizes, with equivalent performance.

[0009] The present invention has been made in view of the above-mentioned problems, and aims to provide a carbonaceous material capable of removing a wide range of harmful substances, from chloroform and the like having a relatively small molecular size to anionic surfactants and the like having a relatively large molecular size, with equivalent performance, as well as a method for producing the same, an adsorption filter, a water purifier cartridge, a water purifier, and a water purification facility.

[0010] As a result of extensive research to achieve the above object, the present inventors have found that a carbonaceous material having a pore volume, iodine adsorption capacity, and Reactive Black pentavalent each falling within a specific range can remove a wide range of harmful substances, from relatively small molecular substances such as chloroform to relatively large molecular substances such as anionic surfactants, with equivalent performance, and have completed the present invention.

[0011] The present invention includes the following embodiments: [1] The volume of pores with a pore diameter of 0.70 nm or less calculated from a nitrogen adsorption isotherm by the QSDFT method per 1 g of a carbonaceous material is 0.16 cm 3 / g or more 0.30cm 3 / g or less, the iodine adsorption amount is 750 mg / g or more and 1,340 mg / g or less, the pentavalent value of Reactive Black is 6.0 g / L or more and 30.0 g / L or less, and the specific surface area determined by the BET method from the N adsorption isotherm at -196°C is 610 m 2 / g or more 1,400m 2 / g or less.

[0012] [2] The carbonaceous material according to [1], wherein the ratio (A / B) of the pore volume (A) of pores with a diameter of 1.00 nm or less calculated per 1 g of the carbonaceous material by the QSDFT method from a nitrogen adsorption isotherm to the pore volume (B) of mesopores determined by the BJH method from an N2 adsorption isotherm at -196°C is 3.0 or more and 8.0 or less.

[0013] [3] The mesopore volume calculated by the BJH method from the N2 adsorption isotherm at -196 °C is 0.030 cm 3 / g or more 0.140cm 3 / g or less.

[0014] [4] The specific surface area calculated by the BET method from the N2 adsorption isotherm at -196°C is 610 m 2 / g or more 1,400m 2 / g or less.

[0015] [5] The carbonaceous material according to [1], having a packing density measured by a tapping method of 0.36 g / mL or more and 0.60 g / mL or less.

[0016] [6] The carbonaceous material according to any one of [1] to [5], which is used to remove at least chloroform and an anionic surfactant in water.

[0017] [7] A method for producing a carbonaceous material according to any one of [1] to [5], comprising: a carbonization step of carbonizing a raw material to obtain a carbonized material; and an activation step of activating the carbonized material to obtain an activated material.

[0018] [8] The method according to [7], further comprising a washing step of washing the activated product.

[0019] [9] The manufacturing method described in [7], wherein the raw material is coconut shell.

[0020]

[10] An adsorption filter comprising the carbonaceous material according to any one of [1] to [5].

[0021]

[11] A water purifier cartridge comprising the carbonaceous material according to any one of [1] to [5].

[0022]

[12] A water purifier comprising the carbonaceous material according to any one of [1] to [5].

[0023]

[13] A water purification facility comprising the carbonaceous material according to any one of [1] to [5].

[0024] According to the present invention, it is possible to provide a carbonaceous material capable of removing a wide range of harmful substances, from chloroform and the like, which have relatively small molecular sizes, to anionic surfactants and the like, which have relatively large molecular sizes, with equivalent performance, as well as a method for producing the same, an adsorption filter, a water purifier cartridge, a water purifier, and a water purification facility.

[0025] In Fig. 1, I is a schematic cross-sectional view of a rotary kiln, and II is a schematic side view of the rotary kiln. Fig. 2 is a schematic cross-sectional view for explaining the rotary kiln.

[0026] Hereinafter, an embodiment for carrying out the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. Note that the present embodiment is an example for explaining the present invention, and the present invention is not limited to only this embodiment.

[0027] [Carbonaceous Material] The carbonaceous material of this embodiment has a pore volume of 0.70 nm or less per 1 g of the carbonaceous material calculated from a nitrogen adsorption isotherm by the QSDFT method of 0.16 cm 3 / g or more 0.30cm 3 / g or less, the iodine adsorption amount is 750 mg / g or more and 1,340 mg / g or less, and the pentavalent value of Reactive Black is 6.0 g / L or more and 67.0 g / L or less.

[0028] By satisfying these requirements, the carbonaceous material can remove a wide range of harmful substances, from substances with relatively small molecular sizes such as chloroform to substances with relatively large molecular sizes such as anionic surfactants, with comparable performance. That is, the carbonaceous material has a pore volume with a pore diameter of 0.70 nm or less within a specific range, and therefore can have high adsorption performance for substances with relatively small molecular sizes such as chloroform. Furthermore, the pore diameter of the carbonaceous material is controlled so as to be suitable for substances with relatively large molecular sizes such as anionic surfactants, and therefore the carbonaceous material can also have high adsorption performance for anionic surfactants.

[0029] Carbonaceous materials can favorably adsorb chloroform and anionic surfactants. Following the 2019 revision of the JIS, volatile organic compounds other than chloroform (bromodichloromethane, dibromochloromethane, bromoform, cis-1,2-dichloroethylene and trans-1,2-dichloroethylene, tetrachloroethylene, trichloroethylene, and benzene) can be tested using chloroform as a substitute for the test method specified in JIS S3201:2019 Appendix A. Therefore, if the chloroform removal performance requirements are met, it can be said that volatile organic substances other than chloroform can also be removed. In other words, carbonaceous materials can favorably adsorb chloroform and one or more of these volatile organic compounds. Furthermore, examples of anionic surfactants include alkyl sulfonates such as linear sodium dodecylbenzenesulfonate. Carbonaceous materials can favorably adsorb one or more of these anionic surfactants.

[0030] In the carbonaceous material, the pore volume (cm) of pores with a diameter of 0.70 nm or less calculated from the nitrogen adsorption isotherm by the QSDFT method per 1 g of the carbonaceous material 3 / g) (hereinafter also referred to simply as "pore volume of pores with a diameter of 0.70 nm or less") is 0.16 cm 3 / g or more 0.30cm 3When the pore volume of pores with diameters of 0.70 nm or less is in the above range, the carbonaceous material exhibits high removal performance mainly for chloroform and the like. When the pore volume of pores with diameters of 0.70 nm or less is in the above range, the carbonaceous material exhibits high removal performance mainly for chloroform and the like. 3 / g or more, the small pore volume effective for removing chloroform and the like having a relatively small molecular size in the micropore volume becomes sufficient, and the adsorption performance for chloroform and the like is significantly improved. 3 / g or less, the amount of pore volume suitable for substances smaller than the molecular size of chloroform, etc., is reduced, and the pore volume suitable for chloroform, etc., is increased accordingly. Therefore, the adsorption performance for chloroform, etc. is significantly improved.

[0031] In this specification, the pores of carbonaceous materials are classified according to the pore size (diameter) of the IUPAC (International Union of Pure and Applied Chemistry) as follows: pores with a pore size of less than 2.0 nm are micropores, pores with a pore size of 2.0 nm or more and 50.0 nm or less are mesopores, and pores with a pore size of more than 50.0 nm are macropores. Micropores are smaller than mesopores and are primarily effective for adsorption of substances with relatively small molecular sizes, such as chloroform. Mesopores are effective for adsorption of substances with relatively large molecular sizes, such as anionic surfactants.

[0032] In this specification, the pore volume of a pore diameter of 0.70 nm or less or a pore diameter of 1.00 nm or less is calculated by the QSDFT method (quenched solid density functional theory). The QSDFT method is an analytical method that can calculate the pore size distribution of about 0.5 nm to about 40 nm, and is intended for pore size analysis of geometrically and chemically irregular microporous and mesoporous carbons. The QSDFT method clearly takes into account the effects of roughness and heterogeneity of the pore surface, and therefore is a method that significantly improves the accuracy of pore size distribution analysis. For specific methods for measuring and calculating the pore volume of a pore diameter of 0.70 nm or less or a pore diameter of 1.00 nm or less, please refer to the Examples.

[0033] The pore volume of the pores having a diameter of 0.70 nm or less is preferably 0.18 cm 3 / g or more 0.29cm 3 / g or less, more preferably 0.20 cm 3 / g or more 0.28cm 3 / g or less, and more preferably 0.22 cm 3 / g or more 0.27cm 3 / g 3 When the pore volume range of pores with diameters of 0.70 nm or less is within the above range, a carbonaceous material tends to be obtained that has higher adsorption performance for chloroform and the like while maintaining removal performance for anionic surfactants and the like.

[0034] The iodine adsorption capacity of the carbonaceous material is 750 mg / g or more and 1,340 mg / g or less. The iodine adsorption capacity is an index of the surface area of ​​pores present in the carbonaceous material that are capable of physically adsorbing chloroform, etc., which have a relatively small molecular size, and anionic surfactants, etc., which have a relatively large molecular size. When the iodine adsorption capacity of the carbonaceous material is within the above range, the carbonaceous material can exhibit high removal performance against anionic surfactants, etc., while maintaining removal performance against chloroform, etc. When the iodine adsorption capacity of the carbonaceous material is 750 mg / g or more, the pore volume of the carbonaceous material is sufficiently large, and the adsorption performance of chloroform, etc. and anionic surfactants, etc. is significantly improved. When the iodine adsorption capacity of the carbonaceous material is 1,340 mg / g or less, the pores of the carbonaceous material are not too large, making it easy to control the pores that adsorb chloroform, etc. and anionic surfactants, etc.

[0035] The iodine adsorption amount is measured and calculated in accordance with JIS K 1474 (2014). For specific methods for measuring and calculating the iodine adsorption amount, see the Examples.

[0036] Since it has a higher removal performance for chloroform and the like and anionic surfactants and the like, the iodine adsorption amount is preferably 900 mg / g or more and 1,330 mg / g or less, more preferably 1,000 mg / g or more and 1,310 mg / g or less.

[0037] The carbonaceous material has a Reactive Black pentavalent of 6.0 g / L or more and 67.0 g / L or less. Reactive Black 5 is a dye represented by the following formula (1) and is also called C.I. Reactive Black-5.

[0038]

[0039] Reactive Black 5 has a large molecular weight of 995.88 and a bulky structure, so the pentavalence of Reactive Black serves as an indicator of the adsorption properties of anionic surfactants and the like with relatively large molecular sizes. When the pentavalence of Reactive Black is within the above range, the carbonaceous material exhibits high adsorption performance, particularly for anionic surfactants and the like, while maintaining its removal performance for chloroform and the like. When the pentavalence of Reactive Black is 6.0 g / L or more, the cumulative pore volume of the large pores in the carbonaceous material does not become too large, and the carbonaceous material can also retain small pores that are effective for chloroform and the like. Therefore, while maintaining its removal performance for chloroform and the like with relatively small molecular sizes, the carbonaceous material can exhibit high removal performance for anionic surfactants and the like with relatively large molecular sizes. When the pentavalence of Reactive Black is 67.0 g / L or less, the number of pores in the carbonaceous material that are suitable for adsorption of anionic surfactants and the like with relatively large molecular sizes increases. Therefore, the adsorption performance for anionic surfactants and the like is significantly improved.

[0040] The Reactive Black 5 valence can be calculated, for example, as follows. That is, first, using an ultraviolet-visible spectrophotometer under conditions of a wavelength of 594 nm and an optical path length (cell length) of 10 mm, the absorbance of a test liquid containing Reactive Black 5 and a residual liquid obtained by mixing a carbonaceous material with the test liquid to thoroughly adsorb Reactive Black 5 onto the carbonaceous material and then removing the carbonaceous material to which Reactive Black 5 has been adsorbed are measured. These absorbances are then used to calculate the residual rate (%) of Reactive Black 5 contained in the residual liquid and the adsorption amount ( / g) of Reactive Black 5 per gram of carbonaceous material. Using these values, the Reactive Black 5 valence (g / L) is calculated as the amount of carbonaceous material required to remove 99% of Reactive Black 5 in 1 L of test liquid. In measuring the Reactive Black 5 valence, it is preferable to use a carbonaceous material whose volume-based cumulative distribution 50% particle size (D50) is adjusted to be 9.0 μm or more and 11.0 μm or less. In this specification, the 50% particle size (D50) refers to a value measured as a volume-based median diameter using a laser diffraction light scattering particle size distribution analyzer. For specific methods for measuring and calculating the pentavalent content of Reactive Black, see the Examples.

[0041] The pentavalent value of Reactive Black is preferably 6.3 g / L or more and 50.0 g / L or less, more preferably 6.5 g / L or more and 40.0 g / L or less, even more preferably 7.0 g / L or more and 30.0 g / L or less, and even more preferably 7.2 g / L or more and 27.0 g / L or less. When the pentavalent value of Reactive Black is within the above range, a carbonaceous material tends to be obtained that has higher adsorption performance for anionic surfactants and the like while maintaining removal performance for chloroform and the like.

[0042] In a carbonaceous material, the ratio (A / B, hereinafter also simply referred to as the "mesopore ratio") of the pore volume (A) having a pore diameter of 1.0 nm or less calculated by the QSDFT method from a nitrogen adsorption isotherm per 1 g of the carbonaceous material (hereinafter also simply referred to as the "pore volume of pores having a pore diameter of 1.00 nm or less") to the mesopore volume (B) obtained by the BJH method from an N adsorption isotherm at −196° C. (hereinafter also simply referred to as the "pore volume of mesopores") is preferably 3.0 or more and 8.0 or less, more preferably 3.5 or more and 7.5 or less, and even more preferably 4.0 or more and 7.0 or less.

[0043] The pore volume of pores with a pore diameter of 1.00 nm or less is an index of small pores that are effective mainly for substances with a relatively small molecular size, such as chloroform. Meanwhile, the pore volume of mesopores is an index of large pores that are effective mainly for substances with a relatively large molecular size, such as anionic surfactants. Therefore, the mesopore ratio is an index showing the balance of performance in the removal performance between chloroform and anionic surfactants.

[0044] When the mesopore ratio is within the above range, it becomes possible to remove a wide range of harmful substances, from substances with relatively small molecular sizes such as chloroform to substances with relatively large molecular sizes such as anionic surfactants, with comparable performance. When the mesopore ratio is 3.0 or more, the proportion of large pores effective for removing anionic surfactants and the like becomes sufficient, and the membrane tends to exhibit high adsorption performance for anionic surfactants and the like. When the mesopore ratio is 8.0 or less, the proportion of small pores effective for removing chloroform and the like becomes sufficient, and the membrane tends to exhibit high adsorption performance for chloroform and the like. For specific methods for measuring and calculating the mesopore ratio, see the Examples.

[0045] In the carbonaceous material, the pore volume of the mesopores (pore volume of the mesopores) determined by the BJH method from the N adsorption isotherm at −196° C. is preferably 0.030 cm 3 / g or more 0.140cm 3 / g or less, and more preferably 0.035 cm 3 / g or more 0.100cm 3 / g or less, and more preferably 0.040 cm 3 / g or more 0.090cm3 / g or less.

[0046] The pore volume of the mesopores is 0.030 cm 3 / g or more, the carbonaceous material can have many relatively large pores that are effective against anionic surfactants and the like. 3 / g or less, the pores of the carbonaceous material do not become too large, and the carbonaceous material can retain many pores that are effective for adsorption of chloroform and the like. Therefore, when the pore volume of the mesopores is within the above range, it tends to be possible to achieve higher levels of performance in removing chloroform and the like and performance in removing anionic surfactants and the like. For specific methods for measuring and calculating the pore volume of the mesopores, see the Examples.

[0047] The carbonaceous material preferably has a specific surface area determined by the BET method from the N adsorption isotherm at −196° C. (hereinafter also simply referred to as “BET specific surface area”) of 610 m 2 / g or more 1,400m 2 / g or less, and more preferably 800m 2 / g or more 1,300m 2 / g or less, and more preferably 900m 2 / g or more 1,300m 2 / g or less.

[0048] The BET specific surface area is an index showing the degree of activation of the carbonaceous material. When the BET specific surface area is in the above range, the carbonaceous material tends to achieve high removal performance against anionic surfactants and the like while maintaining its removal performance against chloroform and the like. 2 / g or more, the carbonaceous material has a sufficient surface area that contributes to physical adsorption, and tends to exhibit high adsorption performance for chloroform and the like. 2 / g or less, the pores of the carbonaceous material do not become too large, and the carbonaceous material tends to have many pores that are effective for adsorption of anionic surfactants, etc. For specific methods for measuring and calculating the BET specific surface area, see the Examples.

[0049] In the carbonaceous material, the packing density measured by the tapping method (hereinafter also simply referred to as "packing density") is preferably 0.36 g / mL or more and 0.60 g / mL or less, more preferably 0.40 g / mL or more and 0.58 g / mL or less, and even more preferably 0.44 g / mL or more and 0.55 g / mL or less. When the packing density is within the above range, the carbonaceous material tends to achieve a higher level of adsorption performance for a wide range of hazardous substances, from chloroform and the like, which have relatively small molecular sizes, to anionic surfactants and the like, which have relatively large molecular sizes. When the packing density is 0.36 g / mL or more, the pores of the carbonaceous material do not become too large, and many pores effective for chloroform and the like and anionic surfactants and the like can be retained. Therefore, the carbonaceous material tends to have high adsorption performance for chloroform and the like and anionic surfactants and the like. When the packing density is 0.60 g / mL or less, there tends to be a sufficient number of pores contributing to physical adsorption. Therefore, carbonaceous materials tend to have higher adsorption performance for chloroform, etc. and anionic surfactants, etc. For specific methods for measuring and calculating the packing density, see the Examples.

[0050] The shape of the carbonaceous material varies depending on the application and is not particularly limited. Examples of such shapes include powder, lump, crushed, sphere, cylinder, elliptical sphere, distorted shape, elliptical cylinder, elliptical truncated cone, and polygonal prism such as triangular prism, quadrangular prism, pentagonal prism, and hexagonal prism, rod shape, thread shape, pellet shape such as solid pellet and hollow pellet, crushed shape such as powder, substrate shape (sheet shape), woven fabric (cloth) shape, felt shape, and block shape.

[0051] The shape of the carbonaceous material is preferably a shape that can be used as a carbonaceous material in known adsorption filters. Examples of such shapes include crushed shapes such as spheres, ellipsoids, distorted shapes, rods, threads, pellets, and powders, as well as substrates (sheets), woven fabrics (cloths), fibers, and blocks. These shapes can be appropriately selected depending on the specific usage. Among these, crushed shapes are preferred, and powder shapes are more preferred, because they have high adsorption performance per unit volume. In the case of powdered carbonaceous materials, their dimensions are not particularly limited, and the particle size and the like can be adjusted appropriately depending on the specific usage.

[0052] In this specification, the term "crushed" refers to particles that are not uniform in shape and typically have any angular shape, and the term "powdered" refers to, for example, fine powder, powder, fine grains, and granular powders, and typically has a 50% particle size (D50) of the cumulative volume distribution of 1 μm or more and 150 μm or less.

[0053] For example, when the carbonaceous material is used as an adsorption filter for a water purifier, the shape thereof is preferably a cylinder or a substrate (sheet), although this shape varies depending on the application and is not particularly limited. When the carbonaceous material has such a shape, the carbonaceous material tends to be able to be used efficiently as an adsorption filter for a water purifier.

[0054] The carbonaceous material is preferably activated carbon.

[0055] [Method for Producing Carbonaceous Material] The carbonaceous material of this embodiment can be obtained by a known production method.

[0056] Examples of such methods include a thermal decomposition method, an activation method, a coating method, and a vapor deposition method. The activation method is preferably used as the production method. By using these production methods, the volume of pores with a diameter of 0.70 nm or less calculated from the nitrogen adsorption isotherm by the QSDFT method per 1 g of the carbonaceous material is 0.16 cm 3 / g or more 0.30cm 3 / g or less, an iodine adsorption amount of 750 mg / g or more and 1,340 mg / g or less, and a Reactive Black pentavalent amount of 6.0 g / L or more and 67.0 g / L or less tend to be more easily produced.

[0057] The method for producing a carbonaceous material according to the present embodiment includes a carbonization step of carbonizing a raw material to obtain a carbonized product, and an activation step of activating the carbonized product to obtain an activated product. The method for producing a carbonaceous material according to the present embodiment preferably includes a cleaning step of cleaning the activated product.

[0058] (Carbonization Step) The method for producing a carbonaceous material includes a carbonization step of carbonizing a raw material to obtain a carbonized product. The raw material is not particularly limited as long as it can be used to obtain the desired carbonaceous material. Examples of raw materials include plant-based or fossil-based raw materials such as wood, wood flour, fruit shells such as coconut shells, seeds such as palm kernels, plums, and peaches, by-products of pulp production, bagasse, blackstrap molasses, coal (peat, lignite, brown coal, bituminous coal, etc.), anthracite, petroleum distillation residue components, petroleum pitch, coke, and coal tar; various synthetic resins such as phenolic resins, vinyl chloride resins, vinyl acetate resins, melamine resins, urea resins, resorcinol resins, celluloid, epoxy resins, polyurethane resins, polyester resins, acrylic resins, and polyamide resins; synthetic rubbers such as polybutylene, polybutadiene, and polychloroprene; other synthetic woods; and synthetic pulp. These raw materials can be used alone or in combination of two or more types in any ratio depending on the required specifications.

[0059] The raw material is preferably a natural product, more preferably coconut shell. By using such a raw material, the pore volume of pores with a diameter of 0.70 nm or less calculated from the nitrogen adsorption isotherm by the QSDFT method per 1 g of the carbonaceous material is 0.16 cm 3 / g or more 0.30cm 3 / g or less, an iodine adsorption amount of 750 mg / g or more and 1,340 mg / g or less, and a Reactive Black pentavalent value of 6.0 g / L or more and 67.0 g / L or less.

[0060] The raw materials may contain additives, etc., as necessary. The additives, etc. may also be added to the carbonized material, as necessary. Examples of such additives include water, coal tar, anhydrous tar, hard pitch, coal tar-based pitch, and petroleum-based pitch. The additives, etc. may be used alone or in combination of two or more. The additives, etc. are typically blended in an amount of 1.0 to 50.0 parts by mass per 100 parts by mass of the raw materials or carbonized material. The total amount of the additives, etc., is typically 1 to 100 parts by mass per 100 parts by mass of the raw materials or carbonized material. When mixing the raw materials or carbonized material with the additives, the amount of oxygen in the raw materials or carbonized material may be adjusted in advance, as necessary, to a range of 1.0 to 20.0% by mass per 100% by mass of the raw materials or carbonized material. The adjustment of the oxygen amount can be performed, for example, by mixing the raw materials or carbonized material with oxygen under heating at a temperature of 150 to 300°C.

[0061] In the method for producing a carbonaceous material, the raw material may be pulverized or molded before being carbonized. Examples of such methods include a method in which the raw material is pulverized into powder using a known pulverizer before being carbonized, and then carbonized. Another example is a method in which the raw material is molded into pellets by a known method before being carbonized, and then carbonized.

[0062] When the raw material is in the form of powder, the particle size of the powder (50% particle size of cumulative volume distribution, D50) is preferably 1 μm or more and 150 μm or less.

[0063] The method for carbonizing the raw material is not particularly limited, and examples thereof include a method in which the raw material is heated to 300° C. or higher and 900° C. or lower, preferably 400° C. or higher and 800° C. or lower, under oxygen-free conditions.

[0064] The carbonization time can be appropriately set depending on the raw material and the equipment used for carbonization. The carbonization time is, for example, 15 minutes to 20 hours, preferably 30 minutes to 10 hours, and more preferably 60 minutes to 5 hours. The carbonization treatment can be carried out using known manufacturing equipment such as a rotary kiln. The carbonization treatment may be carried out under reduced pressure by excluding air, or may be carried out in a nitrogen atmosphere.

[0065] In the method for producing a carbonaceous material, the carbide may be pulverized into powder using a known pulverizer. As a result, the volume of pores with a diameter of 0.70 nm or less calculated by the QSDFT method from the nitrogen adsorption isotherm per 1 g of the carbonaceous material is 0.16 cm 3 / g or more 0.30cm 3 This tends to make it easier to produce a carbonaceous material having an iodine adsorption of 750 mg / g or more and 1,340 mg / g or less, and a reactive black pentavalent of 6.0 g / L or more and 67.0 g / L or less. In a method for producing a carbonaceous material, a carbide may be pulverized into a powder, and then additives and the like may be added to the powdered carbide as needed, followed by kneading by a known method, and the resulting kneaded product may be molded by a known method.

[0066] When the carbide is in the form of powder, the particle size of the carbide (50% particle size of cumulative volume distribution, D50) is preferably 1 μm or more and 150 μm or less.

[0067] In the method for producing a carbonaceous material, a carbide, a powdered carbide, a kneaded product, or a powdered kneaded product may be molded into a cylindrical pellet using a known method. As a result, the volume of pores with a diameter of 0.70 nm or less calculated by the QSDFT method per 1 g of the carbonaceous material from the nitrogen adsorption isotherm is 0.16 cm. 3 / g or more 0.30cm 3This tends to make it easier to produce a carbonaceous material having an iodine adsorption of 750 mg / g or more and 1,340 mg / g or less, and a pentavalent reactive black of 6.0 g / L or more and 67.0 g / L or less. When the carbide is in the form of a cylindrical pellet, the diameter of the cylindrical pellet is preferably 0.1 mm or more and 4.0 mm or less. Furthermore, the aspect ratio (diameter:height) of the cylindrical pellet is preferably 1:1 to 1:10.

[0068] The carbonization step yields a carbonized product of the raw material.

[0069] The method for producing a carbonaceous material may include a washing step and / or a drying step in which the carbonized material is subjected to a washing treatment and / or a drying treatment after the carbonization step. The conditions for these steps are not particularly limited, and known conditions can be used. In addition, the following washing step and drying step may be referred to.

[0070] (Activation Step) The method for producing a carbonaceous material includes an activation step of activating a carbonized material to obtain an activated material.

[0071] As the activation treatment, a known method can be adopted.

[0072] The activation treatment can be carried out using known manufacturing equipment such as a rotary kiln, a fluidized bed furnace, a sleeve furnace (vertical furnace), etc. The activation treatment may be carried out under reduced pressure by excluding air, or under a nitrogen atmosphere.

[0073] The activation treatment is preferably carried out using a rotary kiln. By using a rotary kiln, the activated material, which becomes lighter as the activation of the carbide progresses, can remain in the kiln without scattering outside the furnace. This allows the carbide to be activated more sufficiently, which tends to result in an activated material in which micropores and mesopores are sufficiently developed and the ratio of these pores is controlled within a suitable range.

[0074] Furthermore, the use of a rotary kiln makes it possible to efficiently bring the carbide into contact with the activated gas, which tends to favorably produce a carbonaceous material that has higher adsorption performance for chloroform and anionic surfactants.

[0075] When activation treatment is performed using a rotary kiln, the carbide fed into the rotary kiln preferably has a particle size of 70 mesh (opening size: 243 μm) over sieve and 2 mesh under sieve (opening size: 10.7 mm) using a standard sieve mesh specified in JIS Z8801-1:2019, more preferably 32 mesh (opening size: 490 μm) over sieve and 2 mesh under sieve (opening size: 10.7 mm). By having the particle size of the carbide within the above range, the activated material, whose mass becomes lighter as activation of the carbide progresses, remains in the kiln longer, enabling activation to be performed more efficiently. As the carbide, carbide whose particle size has been adjusted by cutting the raw material to the desired size before the carbonization step may be used, or carbide whose particle size has been adjusted by crushing and classifying the carbide to the desired size may be used.

[0076] Examples of activation treatment methods include gas activation, in which carbide is gasified using activated gases such as water vapor, oxygen, and carbon dioxide, and chemical activation, in which carbide is activated using chemicals such as zinc chloride and phosphoric acid. Gas activation is preferred as the activation treatment method. Using activated gas in gas activation tends to provide a more sufficient reaction rate and enable the reaction rate to be controlled without reducing production efficiency. This tends to make it easier to obtain carbonaceous materials with developed micropores and mesopores. As a result, it tends to be possible to suitably produce carbonaceous materials with a higher level of adsorption performance for a wide range of harmful substances, from relatively small molecular substances such as chloroform to relatively large molecular substances such as anionic surfactants. Note that an inert gas such as nitrogen may be used in combination with the activated gas.

[0077] The partial pressure of the active gas is, for example, 10% or more and 100% or less, and preferably 30% or more and 100% or less.

[0078] As the active gas, it is preferable to use at least one gas selected from the group consisting of water vapor gas and oxygen gas, and it is more preferable to use both water vapor gas and oxygen gas.

[0079] Water vapor gas tends to have a more sufficient reaction rate and allows for better control of the reaction rate without reducing production efficiency. Furthermore, the use of water vapor gas tends to make it easier to obtain a carbonaceous material with developed micropores and mesopores. Therefore, it tends to be possible to suitably produce a carbonaceous material with higher adsorption performance for chloroform and anionic surfactants.

[0080] Furthermore, since the activation reaction is usually an endothermic reaction, a certain amount of heat is required to proceed more efficiently with the activation reaction. In order to maintain this amount of heat, it is preferable to use oxygen gas together with water vapor gas as the activation gas. The volatile gas generated during the activation reaction reacts with the oxygen gas and burns, making it possible to maintain the amount of heat required for activation. Examples of the volatile gas include flammable gases such as hydrogen gas and carbon monoxide gas generated by activating the carbide.

[0081] When water vapor gas and oxygen gas are used as the active gas, the partial pressure of the water vapor is more preferably 33.0% by volume or more and 47.0% by volume or less. The partial pressure of the oxygen gas is more preferably 3.0% by volume or more and 7.0% by volume or less. Note that an inert gas such as nitrogen may be contained as the other gas. In this case, the partial pressure of the inert gas is more preferably 46.0% by volume or more and 64.0% by volume or less. By having these proportions in the above ranges, the pore volume of pores with a diameter of 0.70 nm or less calculated by the QSDFT method from the nitrogen adsorption isotherm per 1 g of the carbonaceous material is 0.16 cm 3 / g or more 0.30cm 3 / g or less, an iodine adsorption amount of 750 mg / g or more and 1,340 mg / g or less, and a Reactive Black pentavalent value of 6.0 g / L or more and 67.0 g / L or less.

[0082] When water vapor gas and oxygen gas are used as the active gas, the flow rate thereof is preferably 10 liters (L) or more and 300 liters (L) or less in total per minute.

[0083] The activation treatment time can be appropriately set depending on conditions such as the raw material, activation temperature, and production equipment. The activation time is, for example, 10 minutes to 36 hours, preferably 30 minutes to 24 hours, more preferably 60 minutes to 12 hours, even more preferably 100 minutes to 360 minutes, and even more preferably 120 minutes to 300 minutes. When the activation time is within the above range, the pore volume of pores with a diameter of 0.70 nm or less calculated by the QSDFT method from the nitrogen adsorption isotherm per gram of carbonaceous material is 0.16 cm 3 / g or more 0.30cm 3 / g or less, an iodine adsorption amount of 750 mg / g or more and 1,340 mg / g or less, and a Reactive Black pentavalent value of 6.0 g / L or more and 67.0 g / L or less.

[0084] The temperature for the activation treatment is not particularly limited, but is preferably 800° C. or higher and 1,250° C. or lower, and more preferably 850° C. or higher and 1,150° C. or lower. By performing the activation treatment at such a temperature, the volume of pores with a diameter of 0.70 nm or less calculated by the QSDFT method from the nitrogen adsorption isotherm per gram of the carbonaceous material becomes 0.16 cm 3 / g or more 0.30cm 3 / g or less, an iodine adsorption amount of 750 mg / g or more and 1,340 mg / g or less, and a Reactive Black pentavalent value of 6.0 g / L or more and 67.0 g / L or less.

[0085] An example of an activation device for performing activation treatment is a rotary kiln as shown in Figures 1 and 2. Figure 1 shows a cross-sectional view I and a side view II of a rotary kiln. Figure 2 is a schematic cross-sectional view for explaining the rotary kiln.

[0086] 1 and 2, a rotary kiln typically includes a tubular body 1 and agitating blades A to F arranged on the inner wall surface of the tubular body 1. The active gas is typically sent from one side to the other, i.e., in the case of a rotary kiln as shown in FIGS. 1 and 2, the active gas is sent in the tubular body 1 in the direction of flow 2 of the active gas.

[0087] The material of the tube body 1 is not particularly limited as long as it is a material that can be used in a rotary kiln, and examples thereof include stainless steel.

[0088] 1 and 2, the number of stirring blades is six, but this can be adjusted appropriately depending on the amount of carbonized material 5 charged as the raw material. The number of stirring blades is usually from 1 to 20, preferably from 3 to 12, and more preferably from 5 to 10. The stirring blades are preferably installed at equal intervals around the central axis of the tubular body 1. For example, if there are six stirring blades, they will be installed every 60° around the central axis of the tubular body 1.

[0089] The height of the agitating blade (height from the wall toward the center of the tubular body 1) can be set appropriately depending on the size of the tubular body 1 and the amount of carbonized material 5 charged, but it is preferable that the height be such that the agitating blade is not covered by the carbonized material 5 charged in the tubular body 1 and is visible. Specifically, when the agitating blade is located at the bottommost surface of the tubular body 1 (the position of agitating blade B in the right diagram of Figure 2), the height of the agitating blade is preferably such that the agitating blade is covered by the carbonized material 5 by 1 / 2 to 2 / 3 from the bottommost surface. It is more preferable that the height of the agitating blade is 10% to 30% of the inner radius of the tubular body 1.

[0090] The thickness of the stirring blade (thickness in the direction of rotation 3 of the tubular body 1) can be set appropriately depending on the size of the tubular body 1 and the amount of carbonized material 5 charged, but it is preferable that the thickness be such that the stirring blade has enough strength to not be damaged by the carbonized material 5 charged into the tubular body 1. Specifically, the thickness of the stirring blade is usually 1% or more and 100% or less of the wall thickness of the tubular body 1, preferably 20% or more and 90% or less, and more preferably 30% or more and 95% or less.

[0091] The material of the stirring blades is not particularly limited as long as it is a material that can be used in a rotary kiln, and examples thereof include stainless steel.

[0092] By arranging the stirring blades in the tubular body 1 in this manner, the contact efficiency between the carbide 5 and the active gas tends to be further improved, which tends to make it easier to produce a carbonaceous material having a desired specific surface area.

[0093] As shown in Figure 2, an appropriate amount of carbide 5 is charged inside tubular body 1. As tubular body 1 rotates in tubular rotation direction 3, for example, carbide 5 captured by agitating blade A is lifted by agitating blade A, and then moves toward carbide falling direction 4, passing over agitating blade A while being mixed, and contacts and is activated with the activated gas, and is then captured between agitating blades A and B. As tubular body 1 rotates in this manner, carbide 5 is mixed while passing over agitating blades A to F, and is activated by efficient and uniform contact with the activated gas. This tends to make it easier to produce a carbonaceous material having a desired pore size distribution.

[0094] In this way, by using a rotary kiln as an activation device, the pore volume of pores with diameters of 0.70 nm or less calculated by the QSDFT method per 1 g of carbonaceous material from the nitrogen adsorption isotherm was 0.16 cm 3 / g or more 0.30cm 3 / g or less, an iodine adsorption amount of 750 mg / g or more and 1,340 mg / g or less, and a Reactive Black pentavalent amount of 6.0 g / L or more and 67.0 g / L or less tend to be more easily produced.

[0095] The activation step yields an activated product.

[0096] The method for producing a carbonaceous material may include a washing step and / or a drying step, in which the activated material is subjected to a washing treatment and / or a drying treatment, etc., after the activation step. The conditions for these steps are not particularly limited, and known conditions can be adopted. In addition, the following washing step and drying step may be referred to.

[0097] (Washing step) The carbonaceous material is preferably obtained through a washing step in which the activated product obtained in the activation step is washed. The washing is more preferably acid washing. By undergoing such a washing step, the volume of pores with a diameter of 0.70 nm or less per gram of the carbonaceous material calculated from the nitrogen adsorption isotherm by the QSDFT method is reduced to 0.16 cm 3 / g or more 0.30cm 3 / g or less, an iodine adsorption amount of 750 mg / g or more and 1,340 mg / g or less, and a Reactive Black pentavalent value of 6.0 g / L or more and 67.0 g / L or less.

[0098] Examples of the acid used in the acid washing include mineral acids such as hydrochloric acid and nitric acid, and organic acids such as formic acid and acetic acid. These acids may be used alone or in combination of two or more.

[0099] The acid concentration, and the temperature and time for acid washing may be adjusted as appropriate so as to obtain the desired carbonaceous material.

[0100] (Drying Step) The carbonaceous material is preferably obtained through a drying step in which the washed product obtained in the washing step is dried.

[0101] The drying method is not particularly limited, and known drying methods such as natural drying, heat drying, and hot air drying can be used. As the drying method, a method of heating and / or reducing pressure is preferred. As a method of drying by heating, a hot air drying method is preferred because it allows for stable drying without uneven drying. Regarding drying conditions, it is preferable to dry the carbonaceous material until the moisture content is 20.0 mass% or less, and more preferably until the moisture content is 10.0 mass% or less.

[0102] Examples of the heating method include heating methods using a stationary constant temperature dryer, a stationary hot air dryer, a vacuum dryer, a rotary evaporator, or a mixing dryer such as a conical dryer or a Nauta dryer. The heating temperature may be any temperature at which the carbonaceous material hardens but does not melt, and is preferably, for example, 40°C or higher and 300°C or lower.

[0103] Examples of the pressure reduction method include a pressure reduction method using an oil pump, an oil-less pump, an aspirator, etc. The pressure in the pressure reduction method is usually 0.00001 MPa or more and 0.05 MPa or less.

[0104] The drying time varies depending on the drying temperature, but is usually about 1 minute to 20 hours.

[0105] The carbonaceous material thus obtained may be used as is, or may be subjected to known methods as necessary to adjust the particle size by crushing, pulverizing, and classifying; to further purify the material by additional washing using, for example, water, an organic solvent, an aqueous acid solution, or an aqueous alkali solution; or to impart durability and adjust the structure by additional heat treatment, thereby obtaining a carbonaceous material.

[0106] The particle size of the carbonaceous material is preferably adjusted so that its particle size (50% particle size of cumulative volume distribution, D50) is 20 μm or more and 500 μm or less. When the particle size of the carbonaceous material is in the above range, the carbonaceous material can be suitably used in, for example, the applications exemplified below.

[0107] [Applications] The carbonaceous material can be suitably used in various applications for removing, adsorbing, concentrating, and recovering chloroform and the like and anionic surfactants and the like. Such applications may involve an appropriate combination of the operations of removal, adsorption, concentration, and recovery. Examples of such applications include adsorption filters, water purifier cartridges, water purifiers, packed towers, water purification equipment including domestic drinking water treatment, water treatment and purification in industrial processes, and wastewater treatment.

[0108] The carbonaceous material is suitable for use in removing chloroform and the like, anionic surfactants and the like.

[0109] [Method for Removing Chloroform, Etc., and Anionic Surfactant, Etc.] The method for removing chloroform, Etc., and anionic surfactant, Etc., includes a removal step of removing chloroform, Etc., and anionic surfactant, Etc., using a carbonaceous material. Chloroform, Etc., and anionic surfactant, Etc., are removed by, for example, being adsorbed onto the carbonaceous material. In addition to using the carbonaceous material of this embodiment as the carbonaceous material, the removal method may include steps similar to known methods for removing chloroform, Etc., and anionic surfactant, Etc., adsorption methods, concentration methods, recovery methods, and the like.

[0110] [Adsorption Filter] The adsorption filter of the present embodiment contains the carbonaceous material of the present embodiment. The adsorption filter is preferably used for a water purifier.

[0111] Because the adsorption filter contains a carbonaceous material, it is possible to adsorb a wide range of harmful substances with equal performance, from relatively small molecular substances such as chloroform to relatively large molecular substances such as anionic surfactants. Therefore, for example, by installing the adsorption filter in a water purifier, it is possible to efficiently remove chloroform and other harmful substances, as well as anionic surfactants, contained in water.

[0112] The adsorption filter preferably comprises a carbonaceous material and a fibrous binder.

[0113] Examples of fibrous binders include those that can be fibrillated to entangle and shape the carbonaceous material. Such fibrous binders may be synthetic or natural. Examples of fibrous binders include acrylic fibers, polyethylene fibers, polypropylene fibers, polyacrylonitrile fibers, cellulose fibers, nylon fibers, aramid fibers, and pulp.

[0114] The fibrous binder may be used alone or in combination of two or more. The fibrous binder is preferably polyacrylonitrile fiber and / or pulp. The use of these fibrous binders can further increase the density and strength of the adsorption filter and suppress performance degradation.

[0115] Since this allows for a higher level of compatibility between the removal performance of chloroform, etc. and anionic surfactants, etc., the adsorption filter preferably contains 20 parts by mass or less, more preferably 10 parts by mass or less, of the fibrous binder per 100 parts by mass of the carbonaceous material. The lower limit is typically 0.01 parts by mass or more. Note that, when the adsorption filter contains other functional components described below, the term "per 100 parts by mass of the carbonaceous material" in relation to the filter composition can be read as "per 100 parts by mass of the carbonaceous material and other functional components combined."

[0116] The adsorption filter may contain other functional components as long as the effects of this embodiment are not impaired. Examples of such other functional components include lead adsorbents such as titanosilicate and zeolite powders that can adsorb and remove soluble lead, ion exchange resins, chelating resins, and various adsorbents containing silver ions and / or silver compounds to impart antibacterial properties.

[0117] When water is passed through an adsorption filter, the water is usually passed at a space velocity (SV) of 300 / hr to 6500 / hr to avoid excessive pressure loss. The performance of the adsorption filter can be confirmed by plotting the relationship between each removal rate calculated from the concentration of the substance to be removed in the raw water and permeated water and the ratio of the amount of water (L) passed from the start of water flow to the volume of the water purification cartridge (mL) (cumulative permeated water volume L / mL).

[0118] (Filtration Capacity) In this specification, the filtration capacity is defined as the amount of water (L) that can be passed through an adsorption filter until the removal rate of the target substance reaches 80%. The water is passed through the adsorption filter at a space velocity (SV) of 3000 / hr.

[0119] (Chloroform filtration capacity) Chloroform filtration capacity can be measured with reference to the volatile organic compound removal performance test in the test method specified in JIS S3201:2019 "Test method for household water purifiers." Specifically, test water is set to a chloroform concentration of 0.060±0.012 (mg / L) and a water temperature of 20°C±3°C, and passed through a carbonaceous material or an adsorption filter. The test raw water and filtrate are analyzed by headspace gas chromatography, and the removal rate (%) is calculated from the test raw water concentration (mg / L) and the filtrate concentration (mg / L). The filtration capacity can be calculated by plotting the removal rate (%) against the cumulative water flow rate (L).

[0120] The adsorption filter of this embodiment has excellent filtering ability, and the chloroform filtering ability measured in accordance with JIS S3201:2019 is usually 1 cm of carbonaceous material. 3 The volume per unit volume is 5.0 L or more, preferably 6.5 L or more, and more preferably 8.0 L or more.

[0121] (Anionic surfactant filtration capacity) Anionic surfactant filtration capacity can be measured using the anionic surfactant removal performance test in the test method specified in JIS S3201:2019 "Household water purifier test method." Specifically, test water is set to an anionic surfactant concentration of 0.20±0.04 (mg / L) and a water temperature of 20°C±3°C, and passed through a carbonaceous material or an adsorption filter. The test raw water and filtrate are analyzed by solid-phase extraction-high performance liquid chromatography, and the removal rate (%) is calculated from the test raw water concentration (mg / L) and the filtrate concentration (mg / L). The filtration capacity can be calculated by plotting the removal rate (%) against the cumulative water flow rate (L).

[0122] The adsorption filter of this embodiment has excellent filtering ability, and therefore, the adsorption filter usually has an anionic surfactant filtering ability measured in accordance with JIS S3201:2019 of 1 cm of carbonaceous material. 3 The volume per unit area is 5.0 L or more, preferably 8.0 L or more, and more preferably 10.0 L or more.

[0123] [Water Purifier Cartridge] The water purifier cartridge of the present embodiment includes the carbonaceous material of the present embodiment. The water purifier cartridge may have the same configuration as known water purifier cartridges, except for including the carbonaceous material of the present embodiment. By including the carbonaceous material, the water purifier cartridge can efficiently remove chloroform and the like and anionic surfactants and the like contained in water. Therefore, for example, by installing the water purifier cartridge in a household water purifier, it is possible to efficiently remove many types of harmful substances, particularly chloroform and the like and anionic surfactants and the like, as described in the "Test Method for Household Water Purifiers" in JIS S3201:2019.

[0124] Examples of the water purification cartridge include a cartridge in which a carbonaceous material is filled in a housing, and a cartridge in which an adsorption filter is filled in a housing. The water purification cartridge may include a combination of a known nonwoven fabric filter, various adsorbents, mineral additives, ceramic filtering materials, hollow fiber membranes, and the like, in addition to the carbonaceous material or adsorption filter according to the present embodiment.

[0125] [Apparatus] The apparatus includes a carbonaceous material. The apparatus may have the same configuration as a known apparatus, except that the carbonaceous material of this embodiment is used as the carbonaceous material.

[0126] The functionality of the carbonaceous material is utilized by an apparatus containing the carbonaceous material. The apparatus is preferably a treatment apparatus. In this specification, the term "treatment apparatus" is not particularly limited as long as it is an apparatus that can remove, adsorb, concentrate, and recover chloroform and other substances and anionic surfactants and other substances contained in treatment targets such as wastewater, waste liquid, and oil using the carbonaceous material of this embodiment. Such a treatment apparatus may be an apparatus that appropriately combines the operations of removal, adsorption, concentration, and recovery. Examples of such treatment apparatus include apparatuses that contain adsorption filters, columns, tanks or baths, tubes, water purifier cartridges, cylinders, and sheets containing carbonaceous materials (hereinafter also simply referred to as "filters, etc. containing carbonaceous materials"), packed towers, and filtration apparatuses such as water purifiers, adsorption devices, and concentration apparatuses. Examples of such apparatus include household drinking water treatment apparatuses, water treatment and purification apparatuses in industrial processes, and wastewater treatment apparatuses.

[0127] The apparatus includes an adsorption section for contacting the carbonaceous material with, for example, chloroform or the like and an anionic surfactant or the like. The adsorption section may contain an adsorbent other than the carbonaceous material according to the present embodiment, as needed. Examples of such adsorbents include activated carbon, zeolite, silica gel, activated alumina, nonwoven fabric, and porous organic compounds other than the carbonaceous material according to the present embodiment.

[0128] Examples of filtration devices include water purifiers, cartridge-type filtration devices, membrane treatment devices, and ultrafiltration membrane devices that contain carbonaceous materials.

[0129] The treatment device may be equipped with other adsorption filters in addition to the adsorption filter containing a carbonaceous material, etc. Examples of such other adsorption filters include metal filters made of stainless steel, aluminum, bronze, copper, titanium, nickel, etc.; and resin filters made of polypropylene, polyvinyl chloride, polyvinylidene chloride, polyethylene, polyamide, fluorine-based resin, etc.

[0130] The processing equipment may be of a batch type or a continuous type, and the carbonaceous material may be used in either type.

[0131] [Water Purifier] The water purifier of the present embodiment includes the carbonaceous material of the present embodiment.

[0132] The water purifier is manufactured using a carbonaceous material or an adsorption filter. By including an adsorption filter, the water purifier can remove a wide range of harmful substances, from relatively small molecular substances such as chloroform to relatively large molecular substances such as anionic surfactants, with the same performance. Therefore, the water purifier can be suitably used in faucets and kitchens.

[0133] The water purifier preferably includes a water purification cartridge, and the water purification cartridge is preferably configured using the carbonaceous material or the adsorption filter according to the present embodiment. For example, the configuration of such a water purification cartridge may refer to the water purifier cartridge described above.

[0134] (Water Purification Method) The water purification method is not particularly limited, but it is preferable to use the water purifier of the present embodiment. The water purification method is not particularly limited, and known methods can be used.

[0135] [Water Purification Equipment] The water purification equipment of this embodiment includes the carbonaceous material of this embodiment. By including the carbonaceous material, the water purification equipment can achieve high levels of both free residual chlorine removal performance and anionic surfactant removal performance.

[0136] Examples of water purification equipment include pure water production equipment, ultrapure water equipment, water purification equipment such as water purification plants, general industrial wastewater treatment equipment, and water purification equipment for pharmaceuticals and food.

[0137] EXAMPLES The present invention will be explained in more detail below by showing examples and comparative examples, but the present invention is not limited to these examples in any way.

[0138] [Evaluation method]

[0139] (1) Pore volume with a pore diameter of 0.70 nm or less Measurement of nitrogen gas adsorption isotherm using BELSORP-MAX Using a specific surface area / pore distribution measuring device (BELSORP (registered trademark)-MAX (product name) manufactured by Microtrac-Bell Corporation), the carbonaceous material was heated at 300°C under vacuum conditions for 3 hours, and then the nitrogen gas adsorption isotherm was measured at a temperature of 77K.

[0140] Measurement of pore volume The pore volume (cm) of micropores with a pore diameter of 0.70 nm or less calculated from the nitrogen adsorption isotherm by the QSDFT method per 1 g of carbonaceous material. 3 / g) was calculated as follows. Specifically, the nitrogen gas adsorption isotherm value obtained in the above "Measurement of nitrogen gas adsorption isotherm using BELSORP-MAX" was used, and the pore size distribution was calculated by applying N2 at 77K carbon [slit pore / cyl. pore (QSDFT Ads.model)] as a calculation model, to obtain the pore volume (cm) of pores with a diameter of 0.70 nm or less. 3 / g) was calculated.

[0141] (2) Iodine Adsorption Amount (Iodine Adsorption Performance) The iodine adsorption amount (mg / g) of the carbonaceous material was measured and calculated. Specifically, the iodine adsorption amount was measured in accordance with JIS K1474 (2014). That is, first, in accordance with JIS Z8801-1, the carbonaceous material was pulverized until 90% or more of the material passed through a 45 μm mesh sieve, and then dried for 3 hours in a constant temperature dryer (DVS402 (trade name) manufactured by Yamato Scientific Co., Ltd.) at 115°C. Thereafter, the material was allowed to cool to room temperature in a desiccator using silica gel as a desiccant, and a carbonaceous material after cooling was obtained.

[0142] Meanwhile, 25.0 g of potassium iodide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and 13.0 g of iodine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were dissolved in approximately 1 L of distilled water to prepare an iodine solution. The iodine solution was titrated with a 0.1 mol / L sodium thiosulfate solution (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and distilled water was added appropriately to the iodine solution to prepare a 0.05 mol / L iodine solution.

[0143] Next, an arbitrary amount of the carbonaceous material after cooling (an amount such that the residual iodine concentration in the supernatant of the filtrate described below is approximately 2.5 g / L) was weighed and placed in a 100 mL Erlenmeyer flask with a stopper, and 50 mL of the 0.05 mol / L iodine solution was added to the entire volume using a pipette. At room temperature (20 ° C or higher and 30 ° C or lower), the mixture was shaken at 200 rpm for 15 minutes using a shaker (medium-sized shaker Reciprocating Shaker NR-10 (trade name) manufactured by Taitec Co., Ltd.) to adsorb iodine to the carbonaceous material, resulting in a mixed solution. Thereafter, the mixed solution was filtered using a cellulose mixed ester membrane filter (A045A025A (trade name) manufactured by Advantec Toyo Co., Ltd.) to obtain a filtrate. 10 mL of the supernatant of the filtrate was collected with a pipette and titrated with 0.1 mol / L sodium thiosulfate solution (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., factor: 1.000), and the residual iodine concentration was calculated using the following formula (I): residual iodine concentration (g / L) = amount (mL) of 0.1 mol / L sodium thiosulfate solution used in titration × factor of 0.1 mol / L sodium thiosulfate solution × 12.69 / 10 (I)

[0144] The amount of iodine adsorption per 1 g of carbonaceous material was calculated using the following formula (II): Amount of iodine adsorption per 1 g of carbonaceous material = (10 × factor of 0.05 mol / L iodine solution - amount (mL) of 0.1 mol / L sodium thiosulfate solution used in titration × factor of 0.1 mol / L sodium thiosulfate solution) × 12.69 × 5 / mass (g) of carbonaceous material

[0145] The factor of the 0.05 mol / L iodine solution was calculated using the formula (III): Factor of 0.05 mol / L iodine solution = (amount (mL) of 0.1 mol / L sodium thiosulfate solution used in titration × factor of 0.1 mol / L sodium thiosulfate solution) / 10 (III)

[0146] An adsorption isotherm was created using Freundlich's adsorption isotherm, with the horizontal axis representing the residual iodine concentration and the vertical axis representing the amount of iodine adsorbed per 1 g of carbonaceous material, and the amount of iodine adsorbed (mg / g) per 1 g of carbonaceous material at a residual iodine concentration of 2.5 g / L was calculated. The amount of iodine adsorbed was taken as the iodine adsorption performance.

[0147] (3) Reactive Black Pentavalent The Reactive Black pentavalent (g / L) of the carbonaceous material was measured. Specifically, the carbonaceous material was first pulverized to a volume-based cumulative distribution of 50% particle size (D50) of approximately 10.0 μm or less, and then dried for 3 hours in a constant temperature dryer (Yamato Scientific Co., Ltd., DVS402 (trade name)) at 115°C. Thereafter, the material was allowed to cool to room temperature in a desiccator using silica gel as a desiccant, and a cooled carbonaceous material was obtained.

[0148] Separately, test solution A containing phosphate buffer solution and Reactive Black 5 (Sigma-Aldrich) was prepared as follows. First, 7.26 g of potassium dihydrogen phosphate (Fujifilm Wako Pure Chemical Industries, Ltd.) and 28.66 g of disodium hydrogen phosphate dodecahydrate (Fujifilm Wako Pure Chemical Industries, Ltd.) were dissolved in 2 L of distilled water to prepare a phosphate buffer solution (pH: 7.0). Then, approximately 0.5 g to 1.2 g of Reactive Black 5 was added to 1 L of the resulting phosphate buffer solution to prepare test solution A. The amount of Reactive Black 5 added to 1 L of the resulting phosphate buffer solution was adjusted as follows: The amount of Reactive Black 5 added to 1 L of the phosphate buffer solution was appropriately adjusted so that the absorbance of a solution obtained by diluting the resulting test solution A 20-fold with distilled water was in the range of 1.18 to 1.23. The absorbance was measured at a wavelength of 594 nm using a glass cell with an optical path length of 10 mm with an ultraviolet-visible spectrophotometer (double beam spectrophotometer U-2910 (trade name) manufactured by Hitachi High-Tech Corp.). Test solution A obtained as described above was diluted 20 times to give test solution B, which was used in the absorbance measurements described below.

[0149] Next, an arbitrary mass of the carbonaceous material after cooling (an amount such that the residual rate of Reactive Black 5 contained in the filtrate is about 10% according to the following formula (V)) was dispensed into a 100 mL Erlenmeyer flask with a stopper, and the carbonaceous material was added to 50 mL of the test liquid A prepared above. The mixture was shaken at a speed of 150 times / min for 5 hours in a water bath at 40°C using a constant temperature shaking bath (Water Bath Shaker MM-10 (trade name) manufactured by Taitec Corporation), to obtain a mixed solution. Thereafter, the mixed solution was filtered using a membrane filter (DISMIC (registered trademark) 25HP045AN (trade name) manufactured by Advantec Toyo Co., Ltd.) to obtain a filtrate.

[0150] The absorbance at a wavelength of 594 nm of each of the obtained test solution B and the filtrate was measured using a glass cell with an optical path length of 10 mm and an ultraviolet-visible spectrophotometer (double-beam spectrophotometer U-2910 (product name) manufactured by Hitachi High-Tech Corporation). Using these absorbances, the amount of Reactive Black 5 adsorbed per 1 g of carbonaceous material (hereinafter simply referred to as "RB5 adsorption amount ( / g) per 1 g of carbonaceous material") was calculated using the following formula (IV): RB5 adsorption amount ( / g) per 1 g of carbonaceous material = (absorbance of test solution B at a wavelength of 594 nm × 20 - absorbance of filtrate at a wavelength of 594 nm) / mass (g) of carbonaceous material (IV)

[0151] The residual rate of Reactive Black 5 contained in the filtrate (hereinafter simply referred to as "RB5 residual rate (%)") was calculated using the following formula (V): RB5 residual rate (%) = (absorbance of filtrate at a wavelength of 594 nm / absorbance of test solution B at a wavelength of 594 nm × 20) × 100 (V)

[0152] Next, a power approximation curve was created using the RB5 residual rate (%) on the horizontal axis and the RB5 adsorption amount ( / g) per gram of carbonaceous material on the vertical axis. Using this power approximation formula, the adsorption amount of Reactive Black 5 when the Reactive Black 5 residual rate was 1% (hereinafter simply referred to as the "RB5 adsorption amount ( / g) when the RB5 residual rate was 1%) was determined, and the Reactive Black 5 valence (g / L) was calculated using formula (VI): Reactive Black 5 valence (g / L) = (absorbance of test solution B at a wavelength of 594 nm × 20 × 0.99 / RB5 adsorption amount ( / g) when the RB5 residual rate was 1%) / 0.05 (L) (VI). Note that 0.05 (L) in formula (VI) is the volume of the test solution.

[0153] (4) Mesopore ratio Measurement of pore volume with a pore diameter of 1.00 nm or less The pore volume (cm) of micropores with a pore diameter of 1.00 nm or less calculated from the nitrogen adsorption isotherm by the QSDFT method per 1 g of carbonaceous material. 3 / g) was calculated as follows. Specifically, the value of the nitrogen gas adsorption isotherm obtained by "Measurement of nitrogen gas adsorption isotherm using BELSORP-MAX" for the pore volume of pores with a pore diameter of 0.70 nm or less was used, and the pore size distribution was calculated by applying N2 at 77K carbon [slit pore / cyl. pore (QSDFT Ads.model)] as the calculation model, thereby obtaining the pore volume (cm) of pores with a pore diameter of 1.00 nm or less. 3 / g) was calculated.

[0154] Measurement of mesopore volume The pore volume (cm) of the mesopores of the carbonaceous material determined by the BJH method from the N adsorption isotherm at -196 °C 3 / g) was measured. Specifically, using the nitrogen adsorption isotherm used in the measurement of the BET specific surface area described below, a curve was obtained by BJH analysis in the relative pressure region of P / P0 = 0.385 or more and 0.99 or less. From the obtained curve, the cumulative pore volume for each pore diameter was calculated, and the pore volume of mesopores with pore diameters of 2.0 nm or more and 50.0 nm or less was calculated by subtracting the cumulative pore volume for pore diameters up to 2.0 nm from the cumulative pore volume for pore diameters up to 50.0 nm.

[0155] Calculation of Mesopore Ratio The mesopore ratio of the carbonaceous material was calculated. Specifically, the mesopore ratio (A / B) of the carbonaceous material was calculated based on the ratio of the pore volume (cm) of pores with a diameter of 1.00 nm or less. 3 / g) (A) and the pore volume of the mesopores (cm 3 The mesopore ratio (A / B) of the carbonaceous material was calculated using the mesopore ratio (A / B) and the pore diameter (A) of 1.00 nm or less according to the following formula (VII):

[0156] (5) Mesopore volume The pore volume (cm) of the mesopores of the carbonaceous material determined by the BJH method from the N adsorption isotherm at -196 °C. 3 / g) was measured and calculated by the "measurement of mesopore volume" in the above mesopore ratio.

[0157] (6) BET specific surface area: The specific surface area (m) of a carbonaceous material determined by the BET method from the N adsorption isotherm at -196 °C. 2Specifically, the BET specific surface area (m 2 / g) was determined as follows. That is, first, using a specific surface area / pore distribution measuring device (BELSORP (registered trademark)-mini II (trade name) manufactured by Microtrac-Bell Corporation), the carbonaceous material was heated at 250°C for 3 hours under reduced pressure (degree of vacuum: 0.1 kPa or less), and then the nitrogen adsorption isotherm of the carbonaceous material at -196°C was measured. Using the obtained nitrogen adsorption isotherm, a straight line was obtained from the obtained curve by BET analysis using the multipoint method in the region of relative pressure P / P0 = 0.01 or more and 0.10 or less, and the BET specific surface area was calculated from this straight line.

[0158] (7) Packing density The packing density (g / mL) of the carbonaceous material measured by the tapping method was calculated. Specifically, the carbonaceous material was first dried for 3 hours in a constant temperature dryer (DVS402 (product name) manufactured by Yamato Scientific Co., Ltd.) at 115°C. Thereafter, the carbonaceous material was allowed to cool to room temperature in a desiccator using silica gel as a desiccant, and a carbonaceous material was obtained after cooling.

[0159] 5.0 g of the carbonaceous material after cooling was weighed and divided into roughly three equal parts, and a portion (about ⅓ of the amount) of the carbonaceous material was placed in a 150 mL measuring cylinder (inner diameter: 31 mm, (Tsutsui Scientific Instruments Co., Ltd.)). A rubber stopper was fitted to the measuring cylinder, and it was set in an automatic tapping device (Tsutsui Scientific Instruments Co., Ltd., powder reduction measuring instrument TPM-3A type (trade name)), and tapping was performed for 1 minute with a shaking width of 45 mm and a shaking frequency of 35 to 36 times per minute. After tapping was completed, another portion (about ⅓ of the amount) of the carbonaceous material that had been previously divided into three equal parts was further added to the measuring cylinder, and a rubber stopper was fitted, and tapping was performed for 1 minute under the same conditions as above. Thereafter, the final portion (about ⅓ of the amount) of the carbonaceous material that had previously been divided into three equal parts was further added to the measuring cylinder, and a rubber stopper was fitted, and tapping was performed for 30 minutes under the same conditions as above.

[0160] After tapping, the rubber stopper was removed, the top surface of the sample in the measuring cylinder was flattened with a spatula or the like, and the sample volume (mL) was visually measured from the graduations on the measuring cylinder. Using the measured sample volume, the packing density measured by the tapping method was calculated according to the following formula (VIII): Packing density (g / mL) = Mass (g) of carbonaceous material / Measured sample volume (mL) (VIII)

[0161] (8) Chloroform filtration capacity The chloroform filtration capacity (L / cm) of the carbonaceous material is measured under the chloroform filtration capacity test conditions specified in the "Test method for household water purifiers" in JIS S3201:2019. 3 The filtration capacity test was carried out by placing 50 cm of carbonaceous material in a descending water column made of Duracon (registered trademark) (polyacetal) (a machined product designed in-house, with an inner diameter of 50 mm and a height of 60 mm). 3 The filtration was carried out at a flow rate of 3.0 L / min.

[0162] (9) Anionic surfactant filtration capacity The anionic surfactant filtration capacity (L / cm) of a carbonaceous material is measured under the test conditions for the anionic surfactant filtration capacity test specified in the "Test method for household water purifiers" in JIS S3201:2019. 3 The filtration capacity test was carried out by placing 50 cm of carbonaceous material in a descending water column made of Duracon (registered trademark) (polyacetal) (a machined product designed in-house, with an inner diameter of 50 mm and a height of 60 mm). 3 The filtration was carried out at a flow rate of 3.0 L / min.

[0163] Example 1 Carbonization Step Coconut shells from the Philippines were carbonized at a temperature of 600° C. for approximately 2 hours to obtain a carbonized product.

[0164] (Activation Treatment) The obtained carbonized material was placed in a rotary kiln with a volume of 1 m as shown in Figs. 1 and 2, which had a furnace heated to 900°C and had agitating blades installed inside. 3 Thereafter, while rotating the kiln at a rotation speed of 3.0 rpm, gas (water vapor 40.0 vol%, oxygen 5.0 vol%, and nitrogen 55.0 vol%) was introduced into the kiln, and activation treatment was carried out for 130 minutes to obtain an activated product.

[0165] In the rotary kiln used, six stirring blades were installed at 60° intervals around the central axis of the tubular body. The height of the stirring blades was 15% to 25% of the inner radius of the tubular body, and the thickness of the stirring blades was 40% to 80% of the thickness of the tubular body.

[0166] (Washing process and drying process, etc.) The obtained activated product was washed with dilute hydrochloric acid, then thoroughly washed with water to remove residual hydrochloric acid, and dried to obtain a dried product. The obtained dried product was then pulverized and sieved using a standard sieve mesh specified in JIS Z8801-1:2019, using a 140 mesh sieve (opening size: 106 μm, Tokyo Screen Co., Ltd.) and a 60 mesh sieve (opening size: 233 μm, Tokyo Screen Co., Ltd.) to obtain a pulverized carbonaceous material 1 that is activated carbon, using a 140 mesh sieve (opening size: 106 μm, Tokyo Screen Co., Ltd.) and a 60 mesh sieve (opening size: 233 μm, Tokyo Screen Co., Ltd.) to obtain a pulverized carbonaceous material 1 that is activated carbon.

[0167] Example 2 A pulverized carbonaceous material 2, which was activated carbon, was obtained in the same manner as in Example 1, except that the activation treatment was carried out for 200 minutes in the activation step.

[0168] Example 3 A pulverized carbonaceous material 3, which was activated carbon, was obtained in the same manner as in Example 1, except that the activation treatment was carried out for 250 minutes in the activation step.

[0169] Example 4 A pulverized carbonaceous material 4, which was activated carbon, was obtained in the same manner as in Example 1, except that the activation treatment was carried out for 280 minutes in the activation step.

[0170] Comparative Example 1 (Carbonization Step) Coconut shells from the Philippines were carbonized at a temperature of 600° C. for approximately 2 hours to obtain a carbonized product.

[0171] (Activation Treatment) The obtained carbonized material was placed in a rotary kiln with a volume of 1 m as shown in Figs. 1 and 2, which had a furnace heated to 900°C and had agitating blades installed inside. 3 Thereafter, while rotating the kiln at a rotation speed of 3.0 rpm, gas (water vapor 40.0 vol%, oxygen 5.0 vol%, and nitrogen 55.0 vol%) was introduced into the kiln, and activation treatment was carried out for 1 minute to obtain an activated product.

[0172] (Washing process and drying process, etc.) The obtained activated material was washed with dilute hydrochloric acid, then thoroughly washed with water to remove residual hydrochloric acid, and dried to obtain a dried material. The obtained dried material was then pulverized and sieved using a standard sieve mesh specified in JIS Z8801-1:2019, using a 140 mesh sieve (opening size: 106 μm, Nishimura Wire Mesh Mfg. Co., Ltd.) and a 60 mesh sieve (opening size: 233 μm, Nishimura Wire Mesh Mfg. Co., Ltd.) to obtain a pulverized carbonaceous material 5, which is activated carbon ....

[0173] Comparative Example 2 A pulverized carbonaceous material 6, which is activated carbon, was obtained in the same manner as in Example 1, except that in the activation step, gas (water vapor 30.0 vol %, oxygen 2.5 vol %, and nitrogen 67.5 vol %) was introduced into the kiln and the activation treatment was carried out for 260 minutes.

[0174] Comparative Example 3 A pulverized carbonaceous material 7, which is activated carbon, was obtained in the same manner as in Example 1, except that in the activation step, gas (water vapor 30.0 vol %, oxygen 2.5 vol %, and nitrogen 67.5 vol %) was introduced into the kiln and activation treatment was carried out for 390 minutes.

[0175]

[0176] The carbonaceous material of the present embodiment can be suitably used in various applications for removing, adsorbing, concentrating, and recovering a wide range of hazardous substances, from chloroform and the like, which have a relatively small molecular size, to anionic surfactants and the like, which have a relatively large molecular size, with equivalent performance.

[0177] This application is based on a Japanese patent application (Patent Application No. 2023-201659) filed on November 29, 2023, the contents of which are incorporated herein by reference.

[0178] A, B, C, D, E, F... agitating blades, 1... pipe body, 2... flow direction of active gas, 3... rotation direction of pipe body, 4... falling direction of carbonized material, 5... carbonized material.

Claims

1. The pore volume of pores with diameters of 0.70 nm or less calculated by the QSDFT method per 1 g of carbonaceous material from the nitrogen adsorption isotherm is 0.16 cm 3 / g or more 0.30cm 3 / g or less, the iodine adsorption amount is 750 mg / g or more and 1,340 mg / g or less, the reactive black pentavalent is 6.0 g / L or more and 30.0 g / L or less, and the specific surface area determined by the BET method from the N2 adsorption isotherm at -196°C is 610 m 2 / g or more 1,400m 2 / g or less.

2. The carbonaceous material according to claim 1, wherein the ratio (A / B) of the pore volume (A) of pores having a pore diameter of 1.00 nm or less calculated from a nitrogen adsorption isotherm by the QSDFT method per 1 g of the carbonaceous material to the pore volume (B) of mesopores calculated from a N2 adsorption isotherm at -196°C by the BJH method is 3.0 or more and 8.0 or less.

3. The mesopore volume calculated from the N2 adsorption isotherm at -196°C using the BJH method is 0.030 cm 3 / g or more 0.140cm 3 / g or less.

4. The carbonaceous material according to claim 1, having a packing density measured by a tapping method of 0.36 g / mL or more and 0.60 g / mL or less.

5. The carbonaceous material according to any one of claims 1 to 4, which is used to remove at least chloroform and an anionic surfactant in water.

6. A method for producing a carbonaceous material according to any one of claims 1 to 4, comprising: a carbonization step of carbonizing a raw material to obtain a carbonized material; and an activation step of activating the carbonized material to obtain an activated material.

7. The method according to claim 6, further comprising a washing step of washing the activation product.

8. The method according to claim 6, wherein the raw material is coconut shell.

9. An adsorption filter comprising the carbonaceous material according to any one of claims 1 to 4.

10. A water purification cartridge comprising the carbonaceous material according to any one of claims 1 to 4.

11. A water purifier comprising the carbonaceous material according to any one of claims 1 to 4.

12. A water purification system comprising the carbonaceous material according to any one of claims 1 to 4.

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