Carbonaceous material, method for producing same, and adsorption filter

Abstract

With respect to a carbonaceous material according to the present invention, the pore volume (cm3 / g) of pores that each have a pore diameter of 0.80 nm or less as calculated per 1 g of the carbonaceous material by a QSDFT method from the nitrogen adsorption isotherm is 0.23 cm3 / g to 0.35 cm3 / g inclusive, the packing density as determined in accordance with JIS K1474 (2014) is 0.43 g / mL to 0.65 g / mL inclusive, and the reactive black 5 value is 3.0 g / L to 60.0 g / L inclusive.

Description

Carbonaceous material, its manufacturing method, and adsorption filter

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

[0002] Volatile organic compounds (VOCs) in automobile exhaust gases not only contain harmful substances such as aldehydes, but also cause the generation of harmful substances through photochemical reactions. Examples of VOCs that are emitted in large quantities and are prone to photochemical reactions include butanes such as n-butane and isobutane, and butenes such as 1,2-butadiene and 1,3-butadiene (hereinafter, in this specification, these butanes and butenes will be collectively referred to simply as "butanes"). Butanes flow into the interior of a vehicle during driving, causing adverse health effects for drivers and unpleasant odors. For this reason, automobiles are typically equipped with automobile filters incorporating activated carbon as an adsorbent for these substances.

[0003] As an adsorbent for such a filter, for example, Patent Document 1 discloses a material having a BET specific surface area of ​​700 m 2 / g or more 1300m 2 The document 1 describes a composite gas adsorbent in which an aromatic aminosulfonic acid and a specific organic acid are impregnated in a predetermined amount on activated carbon having a densitometric value of 0.1% or less. The adsorbent in the document 1 is intended to adsorb a composite gas containing aldehyde and butane.

[0004] JP 2011-143359 A

[0005] However, in the adsorbent of Patent Document 1, high removal performance for acetaldehyde is achieved by the impregnated substance, regardless of the adsorption characteristics of the activated carbon, but removal performance for butane is achieved by controlling only the specific surface area, which is an adsorption characteristic of the activated carbon. However, controlling only the specific surface area does not allow for control of the small micropores effective for butane adsorption, and therefore high butane removal performance cannot be achieved.

[0006] The present invention has been made in view of the above problems, and an object of the present invention is to provide a carbonaceous material having high adsorption performance for butanes, a method for producing the same, and an adsorption filter.

[0007] As a result of extensive research to achieve the above object, the present inventors have found that a carbonaceous material having a pore volume, packing density, and a pentavalent of reactive black each falling within a specific range has high adsorption performance for butanes, and have completed the present invention.

[0008] The present invention includes the following embodiments: [1] The pore volume (cm) of pores with a diameter of 0.80 nm or less calculated from a nitrogen adsorption isotherm by the QSDFT method per 1 g of a carbonaceous material. 3 / g) is 0.23 cm 3 / g or more 0.35cm 3 / g or less, a packing density measured in accordance with JIS K1474 (2014) of 0.43 g / mL or more and 0.65 g / mL or less, and a reactive black pentavalent of 3.0 g / L or more and 60.0 g / L or less.

[0009] [2] The carbonaceous material according to [1], having an iodine adsorption capacity of 710 mg / g or more and 1,500 mg / g or less.

[0010] [3] The carbonaceous material according to [1], wherein the proportion of the pore volume having a pore diameter of 0.80 nm or less is 61% or more and 92% or less.

[0011] [4] The carbonaceous material according to [1], wherein the average pore diameter of the micropores is 0.60 nm or more and 0.80 nm or less.

[0012] [5] The carbonaceous material according to any one of [1] to [4], which is used for adsorbing at least one selected from the group consisting of n-butane, isobutane, 1,2-butadiene, and 1,3-butadiene.

[0013] [6] A method for producing a carbonaceous material according to any one of [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.

[0014] [7] The method according to [6], further comprising a washing step of washing the activated product.

[0015] [8] The manufacturing method described in [6], wherein the raw material is coconut shell.

[0016] [9] An adsorption filter comprising the carbonaceous material according to any one of [1] to [4].

[0017]

[10] The adsorption filter according to [9], wherein the adsorption filter is for use in automobiles.

[0018] According to the present invention, it is possible to provide a carbonaceous material having high adsorption performance for butanes, a method for producing the same, and an adsorption filter.

[0019] FIG. 1 is a schematic cross-sectional view of a fluidized bed furnace.

[0020] 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.

[0021] [Carbonaceous Material] The carbonaceous material of this embodiment has a pore volume (cm) of pores with a pore diameter of 0.80 nm or less calculated from a nitrogen adsorption isotherm by the QSDFT method per 1 g of the carbonaceous material. 3 / g) is 0.23 cm 3 / g or more 0.35cm 3 / g or less, the packing density measured in accordance with JIS K1474 (2014) is 0.43 g / mL or more and 0.65 g / mL or less, and the pentavalent value of Reactive Black is 3.0 g / L or more and 60.0 g / L or less.

[0022] By satisfying these requirements, the carbonaceous material has high adsorption performance for butanes. Therefore, the carbonaceous material of this embodiment is suitable for an adsorption filter for removing butanes. Examples of butanes include butanes such as n-butane and isobutane, and butenes such as 1,2-butadiene and 1,3-butadiene.

[0023] In the carbonaceous material, the pore volume (cm) of pores with a diameter of 0.80 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 0.80 nm or less") is 0.23 cm 3 / g or more 0.35cm 3The carbonaceous material has an excellent adsorption performance for butanes having a relatively small molecular size because the pore volume of the pores having a diameter of 0.80 nm or less is within a specific range. 3 / g or more, the small pore volume suitable for removing substances with a relatively small molecular size is sufficient, and the adsorption performance for butanes is significantly improved. 3 / g or less, the amount of pore volume suitable for substances smaller than the molecular size of butanes is reduced, and the pore volume suitable for butanes is increased accordingly, resulting in a significant improvement in the adsorption performance for butanes.

[0024] In this specification, pores in 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 called micropores, pores with a pore size of 2.0 nm or more and 50.0 nm or less are called mesopores, and pores with a pore size of more than 50.0 nm are called macropores. Micropores are smaller than mesopores and are effective for adsorbing butanes, which have a relatively small molecular size.

[0025] In this specification, the pore volume of pores with a diameter of 0.80 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 analyzing the pore size 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 pores with a diameter of 0.80 nm or less, please refer to the Examples.

[0026] The pore volume of the pores having a diameter of 0.80 nm or less is preferably 0.235 cm 3 / g or more 0.300cm 3 / g or less, more preferably 0.240 cm 3 / g or more 0.270cm 3When the pore volume range of pores with diameters of 0.80 nm or less is within the above range, a carbonaceous material having higher adsorption performance for butanes tends to be obtained.

[0027] In carbonaceous materials, the packing density (hereinafter also simply referred to as "packing density") measured in accordance with JIS K1474 (2014) is 0.43 g / mL or more and 0.65 g / mL or less. The packing density is significantly affected by the pore volume of the carbonaceous material. Therefore, when the packing density is measured using a carbonaceous material in which the 50% particle diameter (D50) of the volume-based cumulative distribution is adjusted to 9.0 μm or more and 11.0 μm or less, the packing density value serves as an indicator of the pore volume possessed by the carbonaceous material. When the packing density is within the above range, the carbonaceous material tends to achieve a higher level of adsorption performance for butanes. When the packing density is 0.43 g / mL or more, the pores of the carbonaceous material do not become too large, and many pores effective for adsorption of butanes can be possessed. When the packing density is 0.65 g / mL or less, there tends to be a sufficient number of pores contributing to the adsorption of butanes. For specific methods for measuring and calculating the packing density, see the Examples.

[0028] The packing density is preferably 0.50 g / mL or more and 0.63 g / mL or less, and more preferably 0.52 g / mL or more and 0.60 g / mL or less. When the packing density is in this range, a carbonaceous material having higher adsorption performance for butanes tends to be obtained.

[0029] The carbonaceous material has a Reactive Black pentavalent of 3.0 g / L or more and 60.0 g / L or less. Reactive Black 5 is a dye represented by the following formula (1) and is also known as C.I. Reactive Black-5.

[0030]

[0031] Reactive Black 5 has a large molecular weight of 995.88 and a bulky structure, so the Reactive Black pentavalent is an indicator of the cumulative pore volume of large pores in the carbonaceous material. When the Reactive Black pentavalent is within the above range, the carbonaceous material exhibits high adsorption performance for butanes. When the Reactive Black pentavalent is 3.0 g / L or more, the number of relatively large pores in the carbonaceous material that have difficulty adsorbing butanes is reduced. This increases the pore volume effective for adsorbing butanes, resulting in significantly improved adsorption performance for butanes. Furthermore, when the Reactive Black pentavalent is 60.0 g / L or less, the carbonaceous material can maintain a volume of pores effective for adsorbing butanes. This significantly improves adsorption performance for butanes.

[0032] 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.

[0033] The pentavalent value of Reactive Black is preferably 10.0 g / L or more and 55.0 g / L or less, more preferably 15.0 g / L or more and 50.0 g / L or less, even more preferably 20.0 g / L or more and 40.0 g / L or less, and even more preferably 22.0 g / L or more and 30.0 g / L or less. When the pentavalent value of Reactive Black is within the above range, a carbonaceous material having higher adsorption performance for butanes tends to be obtained.

[0034] The iodine adsorption capacity of the carbonaceous material is preferably 710 mg / g or more and 1,500 mg / g or less, more preferably 750 mg / g or more and 1,300 mg / g or less, and even more preferably 800 mg / g or more and 1,120 mg / g or less. When the iodine adsorption capacity is within the above range, a carbonaceous material having higher adsorption performance for butanes tends to be obtained.

[0035] The iodine adsorption capacity is an index of the surface area of ​​pores present in a carbonaceous material that are capable of physically adsorbing butanes. When the iodine adsorption capacity of the carbonaceous material is within the above range, the carbonaceous material exhibits high adsorption performance for butanes. When the iodine adsorption capacity is 710 mg / g or more, the pore volume of the carbonaceous material does not become too small, and many pores effective for adsorbing butanes can be retained. When the iodine adsorption is 1,500 mg / g or less, the pores of the carbonaceous material do not become too large, and many pores effective for adsorbing butanes can be retained.

[0036] 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.

[0037] In the carbonaceous material, the proportion of the volume of pores having a pore diameter of 0.80 nm or less is preferably 61% or more and 92% or less, more preferably 70% or more and 90% or less, and even more preferably 73% or more and 89% or less. When the range of the pore volume proportion is within the above range, a carbonaceous material having higher adsorption performance for butanes tends to be obtained.

[0038] The proportion of the pore volume having a pore diameter of 0.80 nm or less is the proportion of small pores possessed by the carbonaceous material. When the proportion of the pore volume having a pore diameter of 0.80 nm or less is 61% or more, the carbonaceous material tends to possess many small pores effective for adsorbing butanes, and to exhibit high adsorption performance. When the proportion of the pore volume having a pore diameter of 0.80 nm or less is 92% or less, the pore diameter is not too small, and the carbonaceous material tends to possess many pores effective for adsorbing butanes, and to exhibit high adsorption performance.

[0039] The ratio of the volume of pores having a diameter of 0.80 nm or less is determined as the ratio of the volume of pores having a diameter of 0.80 nm or less to the volume of pores having a diameter of 2.0 nm or less. For specific methods for measuring and calculating the ratio of the volume of pores having a diameter of 0.80 nm or less, see the Examples.

[0040] The average pore size of the micropores in the carbonaceous material is preferably 0.60 nm or more and 0.80 nm or less, preferably 0.61 nm or more and 0.75 nm or less, and more preferably 0.63 nm or more and 0.70 nm or less. When the average pore size is within the above range, the carbonaceous material tends to have higher adsorption performance for butanes.

[0041] The average pore size of the micropores is the average value of the pore sizes of the micropores in the carbonaceous material. When the average pore size is within the above range, the carbonaceous material tends to more suitably possess pores that are effective for adsorbing butanes.

[0042] The average pore diameter of the micropores is the specific surface area (m ) of micropores with a pore diameter of 2.0 nm or less calculated from the nitrogen adsorption isotherm by the QSDFT method per 1 g of the carbonaceous material. 2 / g) (hereinafter also referred to simply as "specific surface area of ​​micropores"), and the pore volume (cm) of micropores with a pore diameter of 2.0 nm or less calculated by the QSDFT method per 1 g of the carbonaceous material from the nitrogen adsorption isotherm. 3 / g) (hereinafter also referred to simply as "pore volume of micropores") is used to calculate the average pore diameter according to the following formula (2). For specific methods of measuring and calculating the average pore diameter, see the Examples. In measuring and calculating the average pore diameter of micropores, pores with a pore diameter of 2.0 nm are also considered as micropores. Average pore diameter of micropores (nm) = (pore volume of micropores (cm3 / g) / specific surface area of ​​micropores (m 2 / g))×2000...(2)

[0043] 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.

[0044] 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.

[0045] 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.

[0046] For example, when the carbonaceous material is used as an adsorption filter for automobiles, the shape thereof is preferably powder, granules, pellets, or fibers. When the carbonaceous material has such a shape, it is easy to process the material into a sheet and a pleat-filling process, and a suitable filter can be obtained. Therefore, the carbonaceous material is less likely to flow out of the obtained filter, and tends to be suitable for use as an adsorption filter.

[0047] The carbonaceous material is preferably activated carbon.

[0048] [Method for Producing Carbonaceous Material] The carbonaceous material of this embodiment can be obtained by a known production method.

[0049] 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 such a production method, the pore volume (cm) of pores with a diameter of 0.80 nm or less calculated by the QSDFT method per 1 g of the carbonaceous material from the nitrogen adsorption isotherm can be reduced. 3 / g) is 0.23 cm 3 / g or more 0.35cm 3 / g or less, a packing density measured in accordance with JIS K1474 (2014) of 0.43 g / mL or more and 0.65 g / mL or less, and a reactive black pentavalent of 3.0 g / L or more and 60.0 g / L or less.

[0050] 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.

[0051] (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.

[0052] The raw material is preferably a natural product, more preferably coconut shell. By using such a raw material, the pore volume (cm) of pores with a diameter of 0.80 nm or less calculated from the nitrogen adsorption isotherm by the QSDFT method per 1 g of the carbonaceous material can be increased. 3 / g) is 0.23 cm 3 / g or more 0.35cm 3 / g or less, a packing density measured in accordance with JIS K1474 (2014) of 0.43 g / mL or more and 0.65 g / mL or less, and a reactive black pentavalent of 3.0 g / L or more and 60.0 g / L or less.

[0053] The raw material may contain additives, etc., as needed. In addition, the additives, etc. may be added to the carbide, as needed.

[0054] Examples of such additives include water, coal tar, anhydrous tar, hard pitch, coal tar-based pitch, and petroleum-based pitch. The additives may be used singly or in combination of two or more. The additives are typically blended in an amount of 1.0 to 50.0 parts by mass per 100 parts by mass of the raw material or carbonized product. The total amount of the additives is typically 1 to 100 parts by mass per 100 parts by mass of the raw material or carbonized product. When mixing the raw material or carbonized product with the additives, the oxygen content in the raw material or carbonized product 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 material or carbonized product. The oxygen content can be adjusted, for example, by mixing the raw material or carbonized product with oxygen under heating at a temperature of 150 to 300°C.

[0055] 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 or granules 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.

[0056] When the raw material is in the form of a powder, the particle size of the powder (50% particle size of cumulative distribution on a volume basis, D50) is preferably 1 μm or more and 150 μm or less. When the raw material is in the form of granules, the particle size (D50) of the granules is preferably 150 μm or more and 2000 μm or less. When the raw material is in the form of pellets, the particle size (D50) of the pellets is preferably 2000 μm or more and 3000 μm or less.

[0057] 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.

[0058] The carbonization time can be appropriately set depending on the raw material and the equipment used for carbonization. The carbonization time is, for example, from 15 minutes to 20 hours, and preferably from 30 minutes to 10 hours. The carbonization treatment can be carried out using known manufacturing equipment such as a fluidized furnace. The carbonization treatment may be carried out under reduced pressure by excluding air, or may be carried out in a nitrogen atmosphere.

[0059] In the method for producing a carbonaceous material, the carbide may be pulverized into powder or granules using a known pulverizer. Alternatively, the carbide may be formed into pellets using a known method. By these methods, the pore volume (cm) of pores with a diameter of 0.80 nm or less calculated by the QSDFT method per 1 g of the carbonaceous material from the nitrogen adsorption isotherm can be determined. 3 / g) is 0.23 cm 3 / g or more 0.35cm 3 This method tends to make it easier to produce a carbonaceous material having a packing density of 0.43 g / mL or more and 0.65 g / mL or less, as measured in accordance with JIS K1474 (2014), and a reactive black pentavalent of 3.0 g / L or more and 60.0 g / L or less. In the method for producing a carbonaceous material, after pulverizing a charcoal into a powder or granules or forming it into pellets, additives and the like may be added to the powdered charcoal, if necessary, and the mixture may be kneaded by a known method, and the resulting kneaded product may be molded by a known method.

[0060] When the carbide is in the form of a powder, granules, or pellets, the preferred range of the particle size (50% particle size of cumulative volume distribution, D50) of the carbide is the same as the preferred range when the raw material is in the form of a powder, granules, or pellets.

[0061] In the method for producing a carbonaceous material, a carbide, a powdered or granular carbide, a kneaded product, or a powdered or granular kneaded product may be molded into a cylindrical pellet using a known method. This allows the volume of pores (cm) with a pore diameter of 0.80 nm or less calculated by the QSDFT method per 1 g of the carbonaceous material from the nitrogen adsorption isotherm to be determined. 3 / g) is 0.23 cm 3 / g or more 0.35cm 3 This tends to make it easier to produce a carbonaceous material having a packing density of 0.43 g / mL or more and 0.65 g / mL or less, as measured in accordance with JIS K1474 (2014), and a pentavalent reactive black of 3.0 g / L or more and 60.0 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.

[0062] The carbonization step yields a carbonized product of the raw material.

[0063] 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.

[0064] (Activation Step) The method for producing a carbonaceous material includes an activation step of activating a carbonized material to obtain an activated material.

[0065] As the activation treatment, a known method can be adopted.

[0066] 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.

[0067] The activation treatment is preferably carried out using a fluidized bed furnace, which can efficiently bring the carbonized material into contact with an activated gas, and therefore tends to prevent the development of mesopores and provide many micropores to the carbonaceous material, and in particular, to provide pores with a pore diameter of 0.80 nm or less to the carbonaceous material efficiently in a short period of time.

[0068] When activation treatment is performed using a fluidized furnace, the carbide charged into the fluidized furnace preferably has a particle size of 70 mesh (mesh size: 243 μm) over sieve and 10 mesh under sieve (mesh size: 1.54 mm) using a standard wire sieve specified in JIS Z8801-1:2019, and more preferably has a particle size of 70 mesh (mesh size: 243 μm) over sieve and 14 mesh under sieve (mesh size: 1.31 mm). By having the particle size of the carbide within the above range, the activated product, which becomes lighter in mass as activation of the carbide progresses, remains in the fluidized furnace, allowing activation to be performed more efficiently. As the carbide, carbide whose particle size has been adjusted by cutting the raw material to a desired size before the carbonization step may be used, or carbide whose particle size has been adjusted by crushing and classifying the carbide to a desired size may be used.

[0069] Examples of activation treatment methods include methods using active gases such as water vapor gas, oxygen gas, and carbon dioxide gas. By using an active gas as an activation method, it tends to be easier to obtain a carbonaceous material having many micropores, particularly having a larger number of pores with a pore diameter of 0.80 nm or less. Note that an inert gas such as nitrogen may be used in combination with the active gas.

[0070] As the active gas, it is preferable to use one or more gases selected from the group consisting of water vapor gas, oxygen gas, and carbon dioxide gas, and it is more preferable to use all of water vapor gas, oxygen gas, and carbon dioxide gas.

[0071] Water vapor gas has a more sufficient reaction rate and tends to be able to better control the reaction rate without reducing production efficiency. Furthermore, the use of water vapor gas tends to impart many micropores to the carbonaceous material, and in particular, tends to impart a high proportion of pores with a pore diameter of 0.80 nm or less to the carbonaceous material. Therefore, it tends to be possible to suitably produce a carbonaceous material with higher adsorption performance for butanes.

[0072] 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.

[0073] If an excessive amount of oxygen gas is introduced into the fluidized bed furnace as the activated gas, excess oxygen gas that does not react with the volatile gas is generated. This excess oxygen gas may undergo a combustion reaction with the carbonized material and destroy the pores of the carbonaceous material. Therefore, it is preferable to carry out the activation treatment while controlling the amount of oxygen gas within a suitable range.

[0074] When water vapor gas and oxygen gas are used as the active gas, the ratio thereof is preferably 5% by volume or more and 15% by volume or less, more preferably 8% by volume or more and 12% by volume or less, relative to 1% by volume of oxygen gas. When the ratio is within the above range, the pore volume (cm) of pores with a diameter of 0.80 nm or less calculated by the QSDFT method from the nitrogen adsorption isotherm per 1 g of the carbonaceous material is 3 / g) is 0.23 cm 3 / g or more 0.35cm 3 / g or less, a packing density measured in accordance with JIS K1474 (2014) of 0.43 g / mL or more and 0.65 g / mL or less, and a reactive black pentavalent of 3.0 g / L or more and 60.0 g / L or less.

[0075] When water vapor gas, oxygen gas, and carbon dioxide gas are used as the active gas, the partial pressure of the water vapor is preferably 10% by volume or more and 30% by volume or less, and more preferably 15% by volume or more and 25% by volume or less. The partial pressure of the oxygen gas is preferably 0.5% by volume or more and 5% by volume or less, and more preferably 1% by volume or more and 4% by volume or less. The partial pressure of the carbon dioxide gas is preferably 1% by volume or more and 10% by volume or less, and more preferably 3% by volume or more and 7% 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 preferably 55% by volume or more and 88.5% by volume or less, and more preferably 64% by volume or more and 81% by volume or less. When the proportions thereof are within the above ranges, the pore volume (cm ) of pores with a diameter of 0.80 nm or less calculated by the QSDFT method per 1 g of the carbonaceous material from the nitrogen adsorption isotherm can be reduced. 3 / g) is 0.23 cm 3 / g or more 0.35cm 3 / g or less, a packing density measured in accordance with JIS K1474 (2014) of 0.43 g / mL or more and 0.65 g / mL or less, and a reactive black pentavalent of 3.0 g / L or more and 60.0 g / L or less.

[0076] 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.

[0077] 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, 20 minutes to 48 hours, preferably 30 minutes to 36 hours, more preferably 40 minutes to 24 hours, even more preferably 45 minutes to 480 minutes, and even more preferably 50 minutes to 360 minutes. When the activation time is within the above range, the pore volume (cm) of pores with a diameter of 0.80 nm or less calculated by the QSDFT method from the nitrogen adsorption isotherm per 1 g of the carbonaceous material is 3 / g) is 0.23 cm 3 / g or more 0.35cm 3 / g or less, a packing density measured in accordance with JIS K1474 (2014) of 0.43 g / mL or more and 0.65 g / mL or less, and a reactive black pentavalent of 3.0 g / L or more and 60.0 g / L or less.

[0078] The temperature of the activation treatment is preferably 750° C. or higher and 1,200° C. or lower, more preferably 800° C. or higher and 1,100° C. or lower, and even more preferably 870° C. or higher and 950° C. or lower. When the activation temperature is within the above range, the pore volume (cm) of pores with diameters of 0.80 nm or smaller calculated by the QSDFT method from the nitrogen adsorption isotherm per 1 g of the carbonaceous material is reduced. 3 / g) is 0.23 cm 3 / g or more 0.35cm 3 / g or less, a packing density measured in accordance with JIS K1474 (2014) of 0.43 g / mL or more and 0.65 g / mL or less, and a reactive black pentavalent of 3.0 g / L or more and 60.0 g / L or less.

[0079] An example of an activation device for carrying out the activation treatment is a fluidized bed furnace as shown in the schematic cross-sectional view of FIG.

[0080] As shown in Fig. 1, a fluidized furnace typically includes gas inlets 1 to 4 in the lowest layer, a fluidized bed 5 disposed above the fluidized bed 5, a combustible gas combustion layer 6 disposed above the fluidized bed 5, and a gas outlet 8 disposed above the fluidized bed 5. Gas introduced from the gas inlets 1 to 4 is sent in a main gas direction A, and is discharged from the gas outlet 8 while passing through the fluidized bed 5 and the combustible gas combustion layer 6. A carbide as a raw material is charged into the fluidized bed 5, and is activated in the fluidized bed 5 to produce a carbonaceous material.

[0081] Gas inlets 1 to 4 are inlets for introducing water vapor gas, oxygen gas, carbon dioxide gas, and nitrogen gas into the fluidized furnace. Gas inlets 1 to 4 are preferably a water vapor gas inlet, a carbon dioxide gas inlet, a nitrogen gas inlet, and an oxygen gas inlet, respectively. By arranging gas inlets 1 to 4 in this manner and introducing the respective gases into the fluidized furnace, the activation process of the carbide (raw material) tends to proceed more smoothly, making it easier to produce the desired carbonaceous material. While FIG. 1 shows four gas inlets, the number of gas inlets can be appropriately set depending on, for example, the type of raw material, the degree of activation, the size of the equipment, etc. Furthermore, the type of gas introduced into gas inlets 1 to 4 can also be appropriately set depending on, for example, the type of raw material, the degree of activation, the size of the equipment, etc.

[0082] As shown in FIG. 1 , the fluidized furnace preferably includes an oxygen-containing gas inlet 7 for introducing an oxygen-containing gas. By introducing the oxygen-containing gas into the fluidized furnace through the oxygen-containing gas inlet 7, the volatile gas can be efficiently combusted. This generates combustion heat, which can further increase the temperature in the fluidized bed 5, allowing activation to proceed more efficiently. Furthermore, efficient combustion of the volatile gas with the oxygen-containing gas makes it less likely that the oxygen gas introduced through the gas inlets 1 to 4 will become excessive. As a result, the oxygen gas can more effectively suppress the combustion reaction with the carbide, making it easier to control the pores of the carbonaceous material. For these reasons, carbonaceous materials having desired pores and specific surface areas tend to be more easily produced.

[0083] The position of the oxygen-containing gas inlet 7 is preferably at a position in the fluidized furnace that does not contact the upper end of the fluidized bed 5 and that allows the oxygen-containing gas to be introduced into the combustible gas combustion layer 6. The orientation of the oxygen-containing gas inlet 7 is preferably parallel to the main gas direction A and opposite to the main gas direction A (i.e., on the downstream layer side). By arranging the oxygen-containing gas inlet 7 in this manner, the oxygen-containing gas is suitably blown into the combustible gas combustion layer 6, making it possible to further increase the temperature inside the fluidized furnace. This allows the carbide to be activated more uniformly, which tends to make it easier to produce a carbonaceous material having a desired pore size distribution.

[0084] The material of the fluidized bed furnace is not particularly limited as long as it is a material that can be used in fluidized bed furnaces, and examples thereof include stainless steel.

[0085] In this way, by using a fluidized bed furnace as an activation device, the pore volume (cm) of pores with diameters of 0.80 nm or less calculated by the QSDFT method per 1 g of carbonaceous material from the nitrogen adsorption isotherm can be reduced. 3 / g) is 0.23 cm 3 / g or more 0.35cm 3 / g or less, a packing density measured in accordance with JIS K1474 (2014) of 0.43 g / mL or more and 0.65 g / mL or less, and a reactive black pentavalent of 3.0 g / L or more and 60.0 g / L or less.

[0086] The activation step yields an activated product.

[0087] 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.

[0088] (Washing step) The carbonaceous material is preferably obtained through a washing step in which the activated product obtained in the activation step is washed. Washing with water is more preferable. By undergoing such a washing step, the pore volume (cm) of pores with a diameter of 0.80 nm or less calculated by the QSDFT method per 1 g of the carbonaceous material from the nitrogen adsorption isotherm is reduced. 3 / g) is 0.23 cm 3 / g or more 0.35cm 3 / g or less, a packing density measured in accordance with JIS K1474 (2014) of 0.43 g / mL or more and 0.65 g / mL or less, and a reactive black pentavalent of 3.0 g / L or more and 60.0 g / L or less.

[0089] The temperature and time for washing may be adjusted as appropriate so as to obtain the desired carbonaceous material.

[0090] (Drying Step) The carbonaceous material is preferably obtained through a drying step in which the washed product obtained in the washing step is dried.

[0091] 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. In the drying step, drying is preferably performed until the moisture content of the carbonaceous material is 20.0 mass % or less, and more preferably until it is 10.0 mass % or less.

[0092] 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.

[0093] 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.

[0094] The drying time varies depending on the drying temperature, but is usually about 1 minute to 20 hours.

[0095] 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.

[0096] [Applications] The carbonaceous material can be suitably used in various applications for removing, adsorbing, concentrating, and recovering butanes. Such applications may involve an appropriate combination of the operations of removal, adsorption, concentration, and recovery. Examples of such applications include adsorption filters and packed columns.

[0097] The carbonaceous material is suitably used for adsorbing at least one butane selected from the group consisting of n-butane, isobutane, 1,2-butadiene, and 1,3-butadiene. The carbonaceous material is more suitably used for adsorbing at least one selected from the group consisting of n-butane and isobutane, and is more suitably used for adsorbing n-butane.

[0098] [Method for Adsorbing Butanes] The method for adsorbing butanes includes an adsorption step of adsorbing butanes onto a carbonaceous material. Examples of the method for adsorbing butanes include a method of adsorbing butanes onto a carbonaceous material and concentrating the butanes in the carbonaceous material. In addition to using the carbonaceous material of this embodiment as the carbonaceous material, the concentration method may include the same steps as known methods for adsorbing, concentrating, and recovering butanes.

[0099] In the adsorption step, for example, the butanes are brought into contact with a carbonaceous material to cause the butanes to be adsorbed onto the carbonaceous material.

[0100] [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.

[0101] The functions of the carbonaceous material are utilized by a device containing the carbonaceous material. The device is preferably a processing device. In this specification, the term "processing device" is not particularly limited as long as it is a device that can remove, adsorb, concentrate, and recover butanes contained in VOCs and the like using the carbonaceous material of this embodiment. Such a processing device may be a device that appropriately combines the operations of removal, adsorption, concentration, and recovery. Examples of such processing devices include devices that include an adsorption filter, column, tank or bath, tube, cartridge, cylinder, and sheet containing a carbonaceous material (hereinafter also simply referred to as a "filter, etc. containing a carbonaceous material"), as well as an adsorption device and a concentration device.

[0102] The apparatus includes, for example, an adsorption unit for bringing butanes into contact with a carbonaceous material. The adsorption unit 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.

[0103] The treatment device may include other adsorption filters in addition to the adsorption filter containing a carbonaceous material, such as 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.

[0104] The processing equipment may be of a batch type or a continuous type, and the carbonaceous material may be used in either type.

[0105] [Adsorption Filter] The adsorption filter of this embodiment contains the carbonaceous material of this embodiment. The adsorption filter is preferably for use in automobiles.

[0106] Because the adsorption filter contains a carbonaceous material, it has high adsorption performance for butanes. Therefore, for example, by installing an adsorption filter in a car, it is possible to efficiently remove butanes floating in the car interior.

[0107] The adsorption filter preferably comprises a carbonaceous material and a fibrous binder.

[0108] 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.

[0109] 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.

[0110] Because this tends to result in a carbonaceous material with higher adsorption performance for butanes, 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. When the adsorption filter contains other functional components described below, the term "per 100 parts by mass of the carbonaceous material" in the filter composition can be read as "per 100 parts by mass of the carbonaceous material and other functional components combined."

[0111] 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.

[0112] [Automotive Adsorption Filter] The automotive adsorption filter of this embodiment contains the carbonaceous material of this embodiment. The automotive adsorption filter may have the same configuration as known automotive adsorption filters, except for containing the carbonaceous material of this embodiment. By containing the carbonaceous material, the automotive adsorption filter has high adsorption performance for butanes. Therefore, for example, by installing the adsorption filter in an automobile, it is possible to efficiently remove butanes floating in the interior space of the automobile.

[0113] 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.

[0114] [Evaluation method]

[0115] (1) Pore volume with a pore diameter of 0.80 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.

[0116] Measurement of pore volume The pore volume (cm) of micropores with a pore diameter of 0.80 nm or less calculated from the nitrogen adsorption isotherm by the QSDFT method per 1 g of carbonaceous material. 3 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 0.80 nm or less. 3 / g) was calculated.

[0117] (2) Packing Density The packing density (g / mL) of the carbonaceous material was measured in accordance with JIS K1474 (2014). Specifically, the carbonaceous material was first dried for 3 hours in a constant temperature dryer (Yamato Scientific Co., Ltd., DVS402 (trade name)). The material was then allowed to cool to room temperature in a desiccator using silica gel as a desiccant, yielding a carbonaceous material after cooling. The cooled carbonaceous material was introduced into the storage funnel of a packing density measuring container (Toyo Electromagnetic Machinery Mfg. Co., Ltd., Model No. TD-V5 (trade name)), and the carbonaceous material was filled into the packing density measuring container up to the 100 mL mark using the attached vibrator. The mass of the filled carbonaceous material was measured to the nearest 0.1 g.

[0118] (3) Reactive Black Pentavalent The Reactive Black pentavalent (g / L) was measured using a carbonaceous material. 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. The material was then allowed to cool to room temperature in a desiccator using silica gel as a desiccant, yielding a cooled carbonaceous material.

[0119] Separately, test solution A containing phosphate buffer 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 (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 to prepare test solution A. The amount of Reactive Black 5 was adjusted as follows: Specifically, the amount of Reactive Black 5 added to 1 L of phosphate buffer 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.

[0120] 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 according to the following formula (II) is about 10%) 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 rpm for 5 hours in a 40°C water bath 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.

[0121] 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 according to the following formula (I): 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 (I)

[0122] 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 (II): 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 (II)

[0123] 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 (III): 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) (III) Note that 0.05 (L) in formula (III) is the volume of the test solution.

[0124] (4) 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.

[0125] 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.

[0126] 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). The residual iodine concentration was calculated using the following formula (IV): 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 (IV)

[0127] The amount of iodine adsorption per 1 g of carbonaceous material was calculated using the following formula (V): 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 (V).

[0128] The factor of the 0.05 mol / L iodine solution was calculated using formula (VI): 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 (VI)

[0129] 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.

[0130] (5) Average pore diameter of micropores Measurement of specific surface area of ​​pores with diameters of 2.0 nm or less Using the nitrogen adsorption isotherm obtained in the above section "(1) Pore volume of pores with diameters of 0.80 nm or less", the specific surface area (m ) of micropores with diameters of 2.0 nm or less was calculated by the QSDFT method per 1 g of carbonaceous material. 2 / 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, thereby obtaining the specific surface area (m 2 / g) was calculated.

[0131] Measurement of pore volume with a pore diameter of 2.0 nm or less Using the nitrogen adsorption isotherm obtained in the above section "(1) Pore volume with a pore diameter of 0.80 nm or less", the pore volume (cm) of micropores with a pore diameter of 2.0 nm or less was calculated 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 2.0 nm or less. 3 / g) was calculated.

[0132] - Method for calculating the average pore diameter of micropores The average pore diameter (nm) of the micropores in the carbonaceous material was calculated from the specific surface area of ​​the micropores and the pore volume of the micropores obtained above, according to the following formula (VII): average pore diameter (nm) = (pore volume of micropores (cm 3 / g) / specific surface area of ​​micropores (m 2 / g))×2000...(VII)

[0133] (6) Proportion of the volume of pores with a pore diameter of 0.80 nm or less The proportion (%) of the volume of pores with a pore diameter of 0.80 nm or less in the carbonaceous material was calculated. Specifically, the proportion (%) of the volume of pores with a pore diameter of 0.80 nm or less in the carbonaceous material was calculated by multiplying the volume of pores with a pore diameter of 0.80 nm or less (cm) obtained in the above section "(1) Volume of pores with a pore diameter of 0.80 nm or less". 3 / g) and the pore volume (cm) of pores with a diameter of 2.0 nm or less obtained in the above section "(6) Average pore diameter of micropores". 3 / g) according to the following formula (VIII): Percentage of pore volume with a pore diameter of 0.80 nm or less (%) = Volume of pores with a pore diameter of 0.80 nm or less (cm 3 / g) / pore volume (cm) of pores with a diameter of 2.0 nm or less 3 / g)×100...(VIII)

[0134] (8) n-Butane Adsorption Amount (n-Butane Adsorption Performance) The n-butane adsorption amount (mg / g) of the carbonaceous material was measured and calculated. Specifically, in accordance with JIS Z8801-1, the carbonaceous material was first sieved using a test sieve into a particle size range of nominal mesh sizes of 0.600 mm or more and 0.250 mm or less to achieve uniform particle sizes. The sieved carbonaceous material was dried for 3 hours in a constant temperature dryer (DVS402 (product name) manufactured by Yamato Scientific Co., Ltd.) at 115±5°C. Thereafter, the carbonaceous material was allowed to cool to room temperature in a desiccator using silica gel as a desiccant, and a cooled carbonaceous material was obtained.

[0135] Next, 0.492 g of the cooled carbonaceous material was packed into a glass column (manufactured by Iwata Glass Industry Co., Ltd.) having an inner diameter of 28 mm. Thereafter, the packed glass column was placed in a constant temperature liquid bath (LF-681 (trade name) manufactured by ADVANTEC) maintained at 25°C, and pretreatment was performed by passing water vapor gas adjusted to a relative humidity of 50% RT through the glass column at a flow rate of 7.39 L / min for 30 minutes.

[0136] The pretreated glass column was then installed in a gas chromatograph (GC-2014 (trade name) manufactured by Shimadzu Corporation), and n-butane gas (concentration: 80 ppm) adjusted to a relative humidity of 50% RT was passed through the column as the test gas at a flow rate of 7.3 L / min. While measuring the n-butane gas concentrations before and after passing through the column, the breakthrough rate of the n-butane concentration (C) after passing through the column relative to the n-butane concentration (C) before passing through the column was calculated, and the test was continued until this value reached 95%. The breakthrough rate was calculated using the following formula (IX): Breakthrough rate (%) = n-butane concentration (C) after passing through the column / n-butane concentration (C) before passing through the column × 100 (IX)

[0137] The n-butane adsorption amount (mg / g) per 1 g of the carbonaceous material was calculated using the following formula (X) from the n-butane adsorption amount (mg) when the breakthrough rate reached 95% and the amount of carbonaceous material packed into the glass column. The n-butane adsorption amount was taken as the n-butane adsorption performance. n-butane adsorption amount (mg / g) = n-butane adsorption amount (mg) when the breakthrough rate reached 95% / amount of carbonaceous material packed into the glass column (g) ... (X)

[0138] [Example 1] (Carbonization step) Coconut shells from the Philippines were carbonized at a temperature of 600°C for approximately 2 hours and pulverized. After that, the carbonized material was sieved using a standard sieve mesh specified in JIS Z8801-1:2019, with a 70 mesh (opening size: 243 μm, manufactured by Nishimura Wire Mesh Mfg. Co., Ltd.) and an oversized 14 mesh (opening size: 1.31 mm, manufactured by Nishimura Wire Mesh Mfg. Co., Ltd.) to obtain a granular carbide. The particle size (50% particle size of cumulative volume distribution, D50) was adjusted to 405 μm.

[0139] (Activation Treatment) The obtained carbonized material was placed in a fluidized furnace heated to 900° C. as shown in Fig. 1. Then, activated gas (20% by volume of water vapor, 2% by volume of oxygen, 5% by volume of carbon dioxide, and 73% by volume of nitrogen) was introduced into the fluidized furnace, and activation treatment was carried out for 110 minutes to obtain an activated material.

[0140] (Washing step and drying step, etc.) The obtained activated material was thoroughly washed with water and dried to obtain a dried material. Thereafter, the obtained dried material was pulverized to obtain a pulverized carbonaceous material 1, which is activated carbon.

[0141] 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 130 minutes in the activation step.

[0142] 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 170 minutes in the activation step.

[0143] 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 190 minutes in the activation step.

[0144] Example 5 A pulverized carbonaceous material 5, which was activated carbon, was obtained in the same manner as in Example 1, except that the activation treatment was carried out for 205 minutes in the activation step.

[0145] Example 6 A pulverized carbonaceous material 6, which was activated carbon, was obtained in the same manner as in Example 1, except that the activation treatment was carried out for 225 minutes in the activation step.

[0146] Example 7 A pulverized carbonaceous material 7, which was activated carbon, was obtained in the same manner as in Example 1, except that the activation treatment was carried out for 90 minutes in the activation step.

[0147] Example 8 A pulverized carbonaceous material 8, which was activated carbon, was obtained in the same manner as in Example 1, except that the activation treatment was carried out for 240 minutes in the activation step.

[0148] Example 9 A pulverized carbonaceous material 9, which was activated carbon, was obtained in the same manner as in Example 1, except that the activation treatment was carried out for 300 minutes in the activation step.

[0149] [Comparative Example 1] (Carbonization step) Coconut shells from the Philippines were carbonized at a temperature of 600°C for approximately 2 hours and pulverized. After that, the carbonized material was sieved using a standard sieve mesh specified in JIS Z8801-1:2019, with a 70 mesh (opening size: 243 μm, manufactured by Nishimura Wire Mesh Mfg. Co., Ltd.) and a 14 mesh oversize sieve (opening size: 1.31 mm, manufactured by Nishimura Wire Mesh Mfg. Co., Ltd.) to obtain a granular carbide. The particle size (50% particle size of cumulative distribution on a volume basis, D50) was adjusted to 405 μm.

[0150] (Activation Treatment) The obtained carbonized material was placed in a rotary kiln with a volume of 1 m3 and equipped with stirring blades in a furnace heated to 900°C. 3 Thereafter, while rotating the kiln at a rotation speed of 3.0 rpm, activated gas (water vapor 35% by volume, oxygen 5% by volume, carbon dioxide 5% by volume, and nitrogen 55% by volume) was introduced into the kiln and immediately removed, thereby obtaining an activated material.

[0151] (Washing step and drying step, etc.) The obtained activated material was thoroughly washed with water and dried to obtain a dried material. Thereafter, the obtained dried material was pulverized to obtain pulverized carbonaceous material 10, which is activated carbon.

[0152] Comparative Example 2 A pulverized carbonaceous material 11, which was activated carbon, was obtained in the same manner as in Comparative Example 1, except that the activation treatment was carried out for 170 minutes in the activation step.

[0153] Comparative Example 3 A pulverized carbonaceous material 12, which was activated carbon, was obtained in the same manner as in Comparative Example 1, except that the activation treatment was carried out for 220 minutes in the activation step.

[0154] [Comparative Example 4] (Carbonization step) Domestic and Malaysian wood flour was carbonized and pulverized at a temperature of 600°C for approximately 2 hours. After that, the powder was sieved using a standard sieve mesh specified in JIS Z8801-1:2019, with a 20 mesh (opening size: 870 μm, manufactured by Nishimura Wire Mesh Mfg. Co., Ltd.) and a 10 mesh undersize (opening size: 1.54 mm, manufactured by Nishimura Wire Mesh Mfg. Co., Ltd.) to obtain a granular carbide. The particle size (50% particle size of the cumulative volume distribution, D50) was adjusted to 1451 μm.

[0155] (Activation Treatment) The obtained carbonized material was placed in a rotary kiln with a volume of 1 m3 and equipped with stirring blades in a furnace heated to 850°C. 3 Then, while rotating the kiln at a rotation speed of 3.0 rpm, activated gas (water vapor 50% by volume, oxygen 10% by volume, carbon dioxide 35.0% by volume, and nitrogen 5.0% by volume) was introduced into the kiln. 2 / g, thereby obtaining an activated product.

[0156] (Washing step and drying step, 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. Thereafter, the obtained dried material was pulverized to obtain pulverized carbonaceous material 13, which is activated carbon.

[0157] Comparative Example 5: The activation time in the activation step of Example 1 was changed from 110 minutes to 225 minutes, and the granular carbonized material obtained in Example 1 was activated. The obtained activated material was pulverized and then sieved using a standard wire sieve specified in JIS Z8801-1:2019, with a 60 mesh (opening size: 243 μm, manufactured by Nishimura Wire Mesh Mfg. Co., Ltd.) oversize sieve and a 30 mesh undersize sieve (opening size: 550 μm, manufactured by Nishimura Wire Mesh Mfg. Co., Ltd.) to obtain a granular activated material with a particle size (50% particle size of the cumulative volume distribution, D50) of 334 μm. The activated material was then immersed in 0.5 N hydrochloric acid preheated to 95°C and allowed to stand at 95°C for 20 minutes while heating. The immersed activated material was then washed with water until the pH reached approximately 6 to 7, and then dried until the water content of the activated material was 3% by mass or less, thereby obtaining a dried activated carbon. The specific surface area of ​​the dried activated carbon is 1,050 m 2 / g. Next, an 18% by mass aqueous solution of sulfanilic acid (sulfanilic acid: special grade reagent, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd., an aqueous solution containing 0.95 mol of sodium hydroxide per 1 mol of sulfanilic acid) was sprayed onto the dried activated carbon to impregnate the activated carbon with sulfanilic acid, thereby obtaining Impregnated Product 1. The obtained Impregnated Product 1 was left as is at room temperature for 30 minutes, and then a 46% by mass aqueous solution of citric acid was sprayed onto the activated carbon to impregnate the activated carbon with citric acid, thereby obtaining Impregnated Product 2. The obtained Impregnated Product 2 was left as is at room temperature for 60 minutes to obtain Impregnated carbon. Next, the impregnated carbon was dried for 24 hours in a constant temperature dryer (DVS402 (trade name), manufactured by Yamato Scientific Co., Ltd.) at 90°C to obtain Carbonaceous Material 14, which is impregnated carbon (containing 8.0 parts by mass of sulfanilic acid and 4.4 parts by mass of citric acid per 100 parts of activated carbon).

[0158]

[0159] The carbonaceous material of this embodiment can be suitably used in various applications for removing, adsorbing, concentrating, and recovering butanes.

[0160] This application is based on a Japanese patent application (Patent Application No. 2023-201660) filed on November 29, 2023, the contents of which are incorporated herein by reference.

[0161] A...main direction of gas, 1, 2, 3, 4...gas inlet, 5...fluidized bed, 6...combustible gas combustion layer, 7...oxygen-containing gas inlet, 8...gas outlet.

Claims

1. The pore volume (cm) of pores with a diameter of 0.80 nm or less calculated by the QSDFT method per 1 g of carbonaceous material from the nitrogen adsorption isotherm 3 / g) is 0.23 cm 3 / g or more 0.35cm 3 / g or less, a packing density measured in accordance with JIS K1474 (2014) of 0.43 g / mL or more and 0.65 g / mL or less, and a reactive black pentavalent of 3.0 g / L or more and 60.0 g / L or less.

2. The carbonaceous material according to claim 1, having an iodine adsorption amount of 710 mg / g or more and 1,500 mg / g or less.

3. The carbonaceous material according to claim 1, wherein the proportion of the pore volume having a pore diameter of 0.80 nm or less is 61% or more and 92% or less.

4. The carbonaceous material according to claim 1, wherein the average pore size of the micropores is 0.60 nm or more and 0.80 nm or less.

5. The carbonaceous material according to any one of claims 1 to 4, which is used for adsorbing at least one alkane selected from the group consisting of n-butane, isobutane, 1,2-butadiene, and 1,3-butadiene.

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. The adsorption filter of claim 9, wherein the adsorption filter is for use in an automobile.

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