Carbonaceous material and method for producing the same, and adsorbing filter

Abstract

In the carbonaceous material of the present application, the volume (cm 3 / g) of pores having a pore diameter of 0.80 nm or less per 1 g of the carbonaceous material calculated based on nitrogen adsorption isotherm by QSDFT method is 0.23 cm 3 / g or more and 0.35 cm 3 / g or less, the bulk density measured in accordance with Japanese Industrial Standards JIS K1474 (2014) is 0.43 g / mL or more and 0.65 g / mL or less, and the active black 5 value is 3.0 g / L or more and 60.0 g / L or less.

Description

Technical Field

[0001] This invention relates to a carbonaceous material and its manufacturing method, as well as an adsorption filter. Background Technology

[0002] Volatile organic compounds (VOCs) in automobile exhaust not only contain harmful substances such as aldehydes, but can also be the cause of harmful substances generated through photochemical reactions. Examples of VOCs emitted in large quantities and 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 are collectively referred to as "butanes"). Butanes can enter the vehicle's interior during driving, adversely affecting the driver's health or causing discomfort due to their odor. Therefore, automobiles typically have filters containing activated carbon as an adsorbent for these substances.

[0003] As an adsorbent material used in such filters, for example, Patent Document 1 describes a method in which aromatic aminosulfonic acid and a specific organic acid are attached in a predetermined amount to a BET (Brunauer-Emmett-Teller) filter with a specific surface area of ​​700 m². 2 / g or more and 1300m 2 A composite gas adsorbent material formed on activated carbon with a concentration of less than / g. The adsorbent material cited in Reference 1 is intended to adsorb composite gases containing aldehydes and butane.

[0004] Existing technical documents

[0005] Patent documents

[0006] Patent Document 1: Japanese Patent Application Publication No. 2011-143359 Summary of the Invention

[0007] -The technical problem the invention aims to solve-

[0008] However, in the adsorption material of Patent Document 1, for acetaldehyde, its high removal performance is achieved through the attachment of substances, regardless of the adsorption characteristics of activated carbon; for butane, the removal performance is achieved by controlling only the specific surface area, which is an adsorption characteristic of activated carbon. However, by controlling the specific surface area alone, it is impossible to control the small micropores that are effective for butane adsorption, and thus high butane removal performance cannot be obtained.

[0009] The present invention was made in view of the above-mentioned technical problems, and its purpose is to provide a carbonaceous material with high adsorption performance for butanes, a method for manufacturing the same, and an adsorption filter.

[0010] - Technical solutions used to solve technical problems -

[0011] To achieve the above objectives, the inventors conducted in-depth research and discovered that carbonaceous materials with pore volume, filling density, and active black 5 value within specific ranges exhibit high adsorption performance for butanes, thus completing this invention.

[0012] The present invention includes the following embodiments.

[0013] [1] A carbonaceous material, wherein the pore volume (cm³) of 1g of carbonaceous material with a pore size of less than 0.80nm is calculated by QSDFT (Quenched Solid Density Functional Theory) based on nitrogen adsorption isotherms. 3 / g) is 0.23cm 3 / g or more and 0.35cm 3 The filling density, measured according to the 2014 Japanese Industrial Standard JIS K1474, is 0.43 g / mL or more and 0.65 g / mL or less, and the Active Black 5 value is 3.0 g / L or more and 60.0 g / L or less.

[0014] [2] Based on the carbonaceous material described in [1], the iodine adsorption capacity is above 710 mg / g and below 1500 mg / g.

[0015] [3] Based on the carbonaceous material described in [1], the proportion of pore volume with a pore size of 0.80 nm or less is 61% or more and 92% or less.

[0016] [4] Based on the carbonaceous material described in [1], the average pore size of the micropores is above 0.60 nm and below 0.80 nm.

[0017] [5] Based on any one of [1] to [4], the carbonaceous material is used to adsorb at least one selected from the group consisting of n-butane, isobutane, 1,2-butadiene and 1,3-butadiene.

[0018] [6] A method for manufacturing a carbonaceous material, wherein the carbonaceous material is any one of [1] to [4], the manufacturing method comprising: a carbonization step of carbonizing raw materials to obtain a carbide, and an activation step of activating the carbide to obtain an activated material.

[0019] [7] Based on the manufacturing method described in [6], the manufacturing method further includes a cleaning step for cleaning the activated material.

[0020] [8] Based on the manufacturing method described in [6], the raw material is coconut shell.

[0021] [9] An adsorption filter comprising any one of [1] to [4] carbonaceous material.

[0022]

[10] Based on the adsorption filter described in [9], the adsorption filter is an adsorption filter for automobiles.

[0023] -The effects of the invention-

[0024] According to the present invention, a carbonaceous material with high adsorption performance for butanes, a method for manufacturing the same, and an adsorption filter can be provided. Attached Figure Description

[0025] Figure 1 This is a schematic cross-sectional view of a fluidized bed furnace. Detailed Implementation

[0026] The following describes in detail the methods for implementing the present invention (hereinafter referred to as "this embodiment"). It should be noted that the following embodiment is an example for illustrating the present invention, and the present invention is not limited to this embodiment.

[0027] [Carbon-based materials]

[0028] Regarding the carbonaceous material of this embodiment, the pore volume (cm³) of pores with a pore size of 0.80 nm or less per 1 g of carbonaceous material is calculated using the QSDFT method based on the nitrogen adsorption isotherm. 3 / g) is 0.23cm 3 / g or more and 0.35cm 3 The filling density, measured according to Japanese Industrial Standard JIS K1474 (2014), is 0.43 g / mL or more and 0.65 g / mL or less, and the Reactive Black 5 value is 3.0 g / L or more and 60.0 g / L or less.

[0029] Carbonaceous materials possess these characteristics, thereby exhibiting high adsorption performance for butanes. Therefore, the carbonaceous material of this embodiment is suitable for use in adsorption filters for removing butanes. Examples of butanes include butanes such as n-butane and isobutane, as well as butenes such as 1,2-butadiene and 1,3-butadiene.

[0030] In carbonaceous materials, the pore volume (cm³) of pores with a diameter of less than 0.80 nm per 1 g of carbonaceous material is calculated using the QSDFT method based on nitrogen adsorption isotherms. 3 / g (hereinafter also referred to as "pore volume with a pore size of less than 0.80nm") is 0.23cm. 3 / g or more and 0.35cm 3The pore volume of carbonaceous materials with a pore size of less than 0.80 nm falls within a specific range, thus exhibiting excellent adsorption performance for butanes, which have relatively small molecular sizes. In other words, by reducing the pore volume of the pores with a pore size of less than 0.80 nm to 0.23 cm³, the adsorption capacity can be significantly reduced. 3 The pore volume is above / g, thus providing sufficient pore volume for removing substances with relatively small molecular sizes, significantly improving the adsorption performance for butanes. Furthermore, by achieving a pore volume of 0.35 cm³ for pores with a diameter of 0.80 nm or less, the adsorption performance is further enhanced. 3 The amount of pore volume suitable for substances with molecular sizes smaller than butanes is reduced below a certain value ( / g), while the amount suitable for butanes is increased. Therefore, the adsorption performance for butanes is significantly improved.

[0031] In this specification, following the classification criteria of IUPAC (International Union of Pure and Applied Chemistry), the pores of carbonaceous materials are classified according to their pore size (diameter): pores with a diameter less than 2.0 nm are "micropores," pores with a diameter greater than 2.0 nm but less than 50.0 nm are "mesopores," and pores with a diameter greater than 50.0 nm are "macropores." Micropores are smaller than mesopores and are effective for adsorbing butane molecules with relatively small molecular sizes.

[0032] In this specification, pore volumes with pore sizes below 0.80 nm are calculated using the QSDFT (Quenched Solids Density Functional Method). The QSDFT method is an analytical method for analyzing the pore size of geometrically and chemically irregular microporous / mesoporous carbon materials, capable of calculating pore size distributions from approximately 0.5 nm to approximately 40 nm. The QSDFT method explicitly considers the effects of surface roughness and inhomogeneity of the pores; therefore, it significantly improves the accuracy of pore size distribution analysis. For specific measurement and calculation methods of pore volumes below 0.80 nm, please refer to the examples.

[0033] The preferred pore volume for pore sizes below 0.80 nm is 0.235 cm³. 3 / g or more and 0.300cm 3 / g or less, more preferably 0.240cm 3 / g or more and 0.270cm 3 / g or less. When the pore volume range with a pore size of 0.80 nm or less is within the above range, it is likely that carbonaceous materials with higher adsorption performance for butanes can be obtained.

[0034] In carbonaceous materials, the packing density (hereinafter, also referred to as "packing density") measured according to Japanese Industrial Standard JIS K1474 (2014) is 0.43 g / mL or more and 0.65 g / mL or less. Packing density is significantly affected by the pore volume of the carbonaceous material. Therefore, when measuring the packing density of carbonaceous materials using materials with a particle size (D50) of 9.0 μm or more and 11.0 μm or less in a cumulative distribution based on a volume basis, the packing density value becomes an indicator of the pore volume retained by the carbonaceous material. By keeping the packing density within the above range, the carbonaceous material tends to achieve a higher level of adsorption performance for butanes. By keeping the packing density at 0.43 g / mL or more, the pores of the carbonaceous material do not become excessively large, and a greater number of pores effective for adsorbing butanes are retained. By keeping the packing density at 0.65 g / mL or less, sufficient pores conducive to the adsorption of butanes tend to exist. For specific methods of measuring and calculating filling density, please refer to the examples.

[0035] The packing density is preferably 0.50 g / mL or more and 0.63 g / mL or less, more preferably 0.52 g / mL or more and 0.60 g / mL or less. When the packing density is within the above range, it is preferable to obtain a carbonaceous material with higher adsorption performance for butanes.

[0036] The reactive black 5 value for carbonaceous materials is above 3.0 g / L and below 60.0 g / L. Reactive black 5 is a dye represented by the following formula (1), and is also known as CI reactive black 5.

[0037] [Chemical Formula 1]

[0038]

[0039] Reactive Black 5 has a relatively large molecular weight of 995.88 and a large volumetric structure. Therefore, the Reactive Black 5 value serves as an indicator of the cumulative pore volume of the large pores in carbonaceous materials. By maintaining the Reactive Black 5 value within the aforementioned range, carbonaceous materials exhibit high adsorption performance for butanes. By setting the Reactive Black 5 value above 3.0 g / L, the relatively large pores in the carbonaceous material that are difficult to adsorb butanes are reduced. Consequently, the effective pore volume for butane adsorption increases, resulting in a significant improvement in butane adsorption performance. Furthermore, by setting the Reactive Black 5 value below 60.0 g / L, the carbonaceous material can maintain an effective amount of porosity for butane adsorption. Therefore, its butane adsorption performance is significantly improved.

[0040] The Reactive Black 5 value can be calculated, for example, as follows: First, using a UV-Vis spectrophotometer, at a wavelength of 594 nm and a path length (cuvette length) of 10 mm, the absorbance of the test solution containing Reactive Black 5 and the absorbance of the residual liquid obtained after removing the carbonaceous material that has been mixed into the test solution and allowed to fully adsorb Reactive Black 5 are calculated. Then, using these absorbance values, the residual percentage of Reactive Black 5 in the residual liquid and the amount of Reactive Black 5 adsorbed per 1 g of carbonaceous material are calculated. Using these values, the amount of carbonaceous material required to remove 99% of the Reactive Black 5 from 1 L of test solution is calculated as the Reactive Black 5 value (g / L). It should be noted that, in the measurement of the Reactive Black 5 value, the carbonaceous material preferably used has its 50% particle size (D50) in the cumulative distribution based on volume adjusted to be 9.0 μm or more and 11.0 μm or less. In this specification, 50% particle size (D50) refers to the median diameter based on a volume reference, measured using a laser diffraction light scattering particle size distribution measurement device. For specific measurement and calculation methods of the Reactive Black D50 value, please refer to the examples.

[0041] The active black 5-value is preferably 10.0 g / L or higher and 55.0 g / L or lower, more preferably 15.0 g / L or higher and 50.0 g / L or lower, even more preferably 20.0 g / L or higher and 40.0 g / L or lower, and even more preferably 22.0 g / L or higher and 30.0 g / L or lower. When the active black 5-value is within the above range, it is preferable to obtain a carbonaceous material with higher adsorption performance for butanes.

[0042] The iodine adsorption capacity of the carbonaceous material is preferably 710 mg / g or more and 1500 mg / g or less, more preferably 750 mg / g or more and 1300 mg / g or less, and even more preferably 800 mg / g or more and 1120 mg / g or less. When the iodine adsorption capacity is within the above range, it is preferable to obtain a carbonaceous material with higher adsorption performance for butanes.

[0043] Iodine adsorption capacity is an indicator of the surface area of ​​pores in carbonaceous materials capable of physically adsorbing butanes. By maintaining the iodine adsorption capacity of the carbonaceous material within the aforementioned range, the material exhibits high adsorption performance for butanes. By ensuring the iodine adsorption capacity is above 710 mg / g, the pore volume of the carbonaceous material is not excessively small, thus retaining a relatively large number of pores effective for butane adsorption. By maintaining the iodine adsorption capacity below 1500 mg / g, the pore size of the carbonaceous material is not excessively large, thus retaining a relatively large number of pores effective for butane adsorption.

[0044] The iodine adsorption capacity was measured and calculated according to Japanese Industrial Standard JIS K 1474 (2014). For specific measurement and calculation methods for iodine adsorption capacity, please refer to the examples.

[0045] In carbonaceous materials, the proportion of pore volume with a pore size 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 proportion of pore volume is within the above range, it is preferable to obtain carbonaceous materials with higher adsorption performance for butanes.

[0046] The proportion of pore volume with a pore size of 0.80 nm or less represents the proportion of smaller pores retained by carbonaceous materials. When the proportion of pore volume with a pore size of 0.80 nm or less is above 61%, the carbonaceous material retains a relatively large number of smaller pores effective for adsorbing butanes, thus tending to exhibit high adsorption performance. When the proportion of pore volume with a pore size of 0.80 nm or less is below 92%, the pore size does not become too small, and the carbonaceous material retains a relatively large number of pores effective for adsorbing butanes, therefore tending to exhibit high adsorption performance.

[0047] The proportion of pore volume with a pore size of 0.80 nm or less is determined by the ratio of the pore volume with a pore size of 0.80 nm or less to the pore volume with a pore size of 2.0 nm or less. For specific measurement and calculation methods regarding the proportion of pore volume with a pore size of 0.80 nm or less, please refer to the examples.

[0048] The average pore size of the micropores in the carbonaceous material is preferably 0.60 nm or more and 0.80 nm or less, more preferably 0.61 nm or more and 0.75 nm or less, and even more preferably 0.63 nm or more and 0.70 nm or less. When the average pore size is within the above range, it is preferable to obtain a carbonaceous material with higher adsorption performance for butanes.

[0049] The average pore size of micropores refers to the average pore size of micropores in carbonaceous materials. When the average pore size is within the above-mentioned range, carbonaceous materials tend to retain more effective porosity for adsorbing butanes.

[0050] The average pore size of the micropores is the specific surface area (m²) of micropores with a pore size of less than 2.0 nm per 1 g of carbonaceous material, calculated using the QSDFT method based on nitrogen adsorption isotherms. 2 / g (hereinafter also referred to as "specific surface area of ​​micropores"), and the pore volume (cm³) of micropores with a pore size of less than 2.0 nm per 1g of carbonaceous material calculated by QSDFT method based on nitrogen adsorption isotherms. 3 / g (hereinafter also referred to as "pore volume of micropores") is calculated by the following formula (2). For the specific measurement and calculation method of the average pore size, please refer to the example. It should be noted that when measuring and calculating the average pore size of micropores, pores with a pore size of 2.0 nm are also considered as micropores.

[0051] Average pore diameter (nm) of micropores = (pore volume of micropores (cm³)) 3 / g) / Specific surface area of ​​micropores (m²) 2 / g))×2000…(2)

[0052] The shape of carbonaceous materials varies depending on their application and is not particularly limited. Examples of such shapes include: powder, block, crushed, spherical, cylindrical, ellipsoidal sphere, distorted, elliptical cylinder, elliptical cone, and multi-faceted prisms such as triangular prisms, quadrangular prisms, pentagonal prisms, and hexagonal prisms; granular, solid, and hollow granules; crushed, powdery, substrate-like (sheet-like), woven fabric-like, felt-like, and block-like materials.

[0053] The shape of the carbonaceous material is preferably one that can be used in known adsorption filters. Examples of such shapes include: spherical, ellipsoidal, distorted, rod-shaped, filamentous, granular, powdered, and other broken forms, substrate-like (sheet-like), woven fabric-like, fibrous, and block-like. These shapes can be appropriately selected depending on the specific application. Among these shapes, from the viewpoint of high adsorption performance per unit volume, a broken shape is preferred for the carbonaceous material, and a powdered shape is more preferred. In the case of powdered carbonaceous material, its size is not particularly limited; the particle size can be appropriately adjusted according to the specific application.

[0054] In this specification, "fragmented" refers to particles of any shape that are not fixed in shape and are usually angular. Additionally, "powdered" refers to powders such as micro-powder, powder, fine granules, and granules, typically with 50% of the particle size (D50) in the cumulative distribution based on volume being 1 μm or more and 150 μm or less.

[0055] For example, when using carbonaceous materials as adsorption filters for automobiles, their shape is preferably powder, granules, pellets, or fibers. When carbonaceous materials are in these shapes, they are easier to process into sheets and pleats, resulting in suitable filters. Therefore, carbonaceous materials are less likely to flow out of the resulting filter, making them suitable for use as adsorption filters.

[0056] Activated carbon is the preferred carbonaceous material.

[0057] [Manufacturing methods for carbonaceous materials]

[0058] The carbonaceous material of this embodiment can be obtained by known manufacturing methods.

[0059] Examples of such methods include thermal decomposition, activation, coating, and vapor deposition. Activation is preferred as the manufacturing method. By using these methods, it becomes easier to manufacture pore volumes (cm³) per gram of carbonaceous material with pore sizes of 0.80 nm or less, calculated using the QSDFT method based on nitrogen adsorption isotherms. 3 / g) is 0.23cm 3 / g or more and 0.35cm 3 Carbonaceous materials with a filling density of 0.43 g / mL or more and 0.65 g / mL or less as measured according to Japanese Industrial Standard JIS K1474 (2014), and an Active Black 5 value of 3.0 g / L or more and 60.0 g / L or less.

[0060] The method for manufacturing carbonaceous materials according to this embodiment includes a carbonization step of carbonizing raw materials to obtain carbides, and an activation step of activating the carbides to obtain activated materials. Preferably, the method for manufacturing carbonaceous materials according to this embodiment includes a cleaning step of cleaning the activated materials.

[0061] (Carbonization process)

[0062] The manufacturing method of carbonaceous materials includes a carbonization process that carbonizes raw materials to obtain carbides.

[0063] As raw materials, there are no particular limitations on any material that can produce the desired carbonaceous material. Examples of raw materials include: wood, wood flour, fruit shells such as coconut shells, palm kernels, plum and peach seeds, byproducts of pulp production, bagasse, molasses waste, coal (peat, sub-bituminous coal, lignite, and bituminous coal, etc.), anthracite, petroleum distillation residues, petroleum asphalt, coke, and coal tar, as well as other plant-based or fossil-based raw materials; various synthetic resins such as phenolic resin, vinyl chloride resin, vinyl acetate resin, melamine resin, urea resin, resorcinol resin, celluloid, epoxy resin, polyurethane resin, polyester resin, acrylic resin, and polyamide resin; synthetic rubbers such as polybutene, polybutadiene, and polychloroprene; other synthetic woods; and synthetic pulp. These raw materials can be used individually or in any proportion of two or more depending on the required specifications.

[0064] The raw material is preferably a natural product, more preferably coconut shell. By using such a raw material, it is easier to manufacture pore volumes (cm³) per 1g of carbonaceous material with pore sizes below 0.80nm, calculated using the QSDFT method based on nitrogen adsorption isotherms. 3 / g) is 0.23cm 3 / g or more and 0.35cm 3 Carbonaceous materials with a filling density of 0.43 g / mL or more and 0.65 g / mL or less as measured according to Japanese Industrial Standard JIS K1474 (2014), and an Active Black 5 value of 3.0 g / L or more and 60.0 g / L or less.

[0065] The raw materials may also contain additives, etc., as needed. In addition, additives, etc., may be added to the carbides as needed.

[0066] Examples of such additives include: water, coal tar, anhydrous tar, hard pitch, coal tar-based pitch, and petroleum-based pitch. Additives can be used alone or in combination of two or more.

[0067] Typically, additives, etc., are added in amounts of 1.0 part by mass and 50.0 parts by mass relative to 100 parts by mass of the raw material or carbide. Furthermore, the total amount of additives, etc., is typically 1 part by mass and 100 parts by mass relative to 100 parts by mass of the raw material or carbide. When mixing the raw material or carbide with additives, the oxygen content in the raw material or carbide may be pre-adjusted to a range of 1.0% by mass and 20.0% by mass relative to 100% by mass, as needed. Oxygen content adjustment can be achieved, for example, by mixing the raw material or carbide with oxygen under heating conditions of 150°C to 300°C.

[0068] In methods for manufacturing carbonaceous materials, the raw materials may be pulverized or shaped before carbonization. One example of such a method is to pulverize the raw materials into powder or granules using a known pulverizer before carbonization. Another example is to shape the raw materials into granules using a known method before carbonization.

[0069] When the raw material is in powder form, the particle size of the powder (50% particle size in the cumulative distribution based on volume, D50) is preferably 1 μm or more and 150 μm or less. When the raw material is in granular form, the particle size (D50) is preferably 150 μm or more and 2000 μm or less. When the raw material is in granular form, the particle size (D50) is preferably 2000 μm or more and 3000 μm or less.

[0070] There are no particular limitations on the carbonization method of the raw materials. For example, heating to above 300°C and below 900°C under anaerobic conditions, preferably above 400°C and below 800°C, can be cited.

[0071] The carbonization time can be appropriately set according to the raw materials and the equipment used for carbonization. For example, a carbonization time of 15 minutes or more and 20 hours or less is preferred, with 30 minutes or more and 10 hours or less being preferable. The carbonization process can be performed using known manufacturing equipment such as a fluidized bed furnace. Furthermore, the carbonization process can also be performed under reduced pressure with air removal or under a nitrogen atmosphere.

[0072] In the manufacturing methods of carbonaceous materials, known pulverizers can be used to pulverize carbides into powder or granules. Alternatively, known methods can be used to shape carbides into granules. Therefore, it is easier to manufacture pore volumes (cm³) per 1g of carbonaceous material with pore sizes of 0.80 nm or less, calculated using the QSDFT method based on nitrogen adsorption isotherms. 3 / g) is 0.23cm 3 / g or more and 0.35cm 3 Carbonaceous materials with a filling density of 0.43 g / mL or less and 0.65 g / mL or less as measured according to Japanese Industrial Standard JIS K1474 (2014), and an Active Black 5 value of 3.0 g / L or more and 60.0 g / L or less. In the manufacturing method of carbonaceous materials, after pulverizing the carbide into powder or granules, or molding it into granules, additives may be added to the powdered carbide as needed, and the mixture may be kneaded using known methods, and then the resulting mixture may be shaped using known methods.

[0073] When the carbide is in the form of powder, granules, or pellets, the preferred range of particle size (50% particle size in the cumulative distribution based on volume, D50) of each carbide is the same as the preferred range described above when the raw material is in the form of powder, granules, or pellets.

[0074] In the manufacturing methods of carbonaceous materials, known methods can also be used to shape carbides, powdered or granular carbides, mixtures, or powdered or granular mixtures into cylindrical granules. Therefore, it is easier to manufacture pore volumes (cm³) with pore sizes below 0.80 nm per 1g of carbonaceous material, calculated using the QSDFT method based on nitrogen adsorption isotherms. 3 / g) is 0.23cm 3 / g or more and 0.35cm 3 Carbonaceous materials with a filling density of 0.43 g / mL or more and 0.65 g / mL or less as measured according to Japanese Industrial Standard JIS K1474 (2014), and an Active Black 5 value of 3.0 g / L or more and 60.0 g / L or less.

[0075] When the carbide is shaped into cylindrical granules, the diameter of the cylindrical granules is preferably 0.1 mm or more and 4.0 mm or less. In addition, the aspect ratio (diameter:height) of the cylindrical granules is preferably 1:1 to 1:10.

[0076] The carbonization process described above yields carbonized materials.

[0077] The manufacturing method of carbonaceous materials may also include a cleaning process to clean the carbides and / or a drying process to dry the carbides after the carbonization process. There are no particular limitations on the conditions in these processes, and known conditions can be used. Alternatively, the cleaning and drying processes described below can also be referenced.

[0078] (Activation process)

[0079] The manufacturing method of carbonaceous materials includes an activation process that activates carbides to obtain activated materials.

[0080] As an activation treatment, known methods can be used.

[0081] The activation process can be performed using known manufacturing equipment such as rotary kilns, fluidized bed furnaces, and Sleip furnaces (vertical furnaces). Alternatively, the activation process can be carried out under reduced pressure with air removal or under a nitrogen atmosphere.

[0082] Activation treatment is preferably performed using a fluidized bed furnace. Fluidized bed furnaces enable efficient contact between carbides and active gases, thus tending to impart more micropores to carbonaceous materials without developing mesopores, especially efficiently imparting pores with a diameter of less than 0.80 nm to carbonaceous materials in a short time.

[0083] When using a fluidized bed furnace for activation, the carbides fed into the furnace are sieved using a standard metal mesh sieve as specified in Japanese Industrial Standard JIS Z8801-1:2019. Preferably, the carbides have a particle size that does not pass through 70 mesh (sieve aperture size: 243 μm) and passes through 10 mesh (sieve aperture size: 1.54 mm), more preferably, a particle size that does not pass through 70 mesh (sieve aperture size: 243 μm) and passes through 14 mesh (sieve aperture size: 1.31 mm). By ensuring the carbide particle size is within the above range, the activated material, which becomes lighter as activation progresses, remains in the fluidized bed furnace, enabling more efficient activation. The carbides can be either those whose particle size has been adjusted by pre-cutting the raw material to the desired size before the carbonization process, or those whose particle size has been adjusted by crushing and classifying the carbides to the desired size.

[0084] Activation methods include, for example, using reactive gases such as water vapor, oxygen, and carbon dioxide. By using reactive gases as the activation method, it is generally easier to obtain carbonaceous materials with more micropores, especially those with a pore size of 0.80 nm or less. It should be noted that inert gases such as nitrogen can also be used simultaneously with the reactive gas.

[0085] As the active gas, it is preferred to use one or more selected from the group consisting of water vapor, oxygen and carbon dioxide gas, and more preferably to use all of water vapor, oxygen and carbon dioxide gas.

[0086] Water vapor exhibits a more efficient reaction rate, allowing for further control of the reaction rate without reducing production efficiency. Furthermore, the use of water vapor tends to impart more micropores to carbonaceous materials, particularly a higher proportion of pores with diameters below 0.80 nm. Therefore, it is preferable to manufacture carbonaceous materials with superior adsorption performance for butanes.

[0087] Typically, activation reactions are endothermic; therefore, a certain amount of heat is required for the activation reaction to proceed more efficiently. To maintain this heat, it is preferable to use oxygen as an active gas in addition to water vapor. The volatile gases produced during the activation reaction react with the oxygen and burn, thereby maintaining the heat required for activation. It should be noted that flammable gases such as hydrogen and carbon monoxide produced during the activation of carbides can be cited as examples of volatile gases.

[0088] If excess oxygen is introduced into the fluidized bed furnace as an active gas, excess oxygen that has not reacted with the volatile gases will be generated. This excess oxygen will react with carbides in a combustion reaction, potentially damaging the porosity of the carbonaceous material. Therefore, it is preferable to perform the activation process while controlling the amount of oxygen within an appropriate range.

[0089] When using water vapor and oxygen as the active gases, their ratio is preferably 5% to 15% of oxygen, and more preferably 8% to 12% of water vapor, relative to 1% of oxygen by volume. By keeping their ratio within the above range, it is easier to produce a pore volume (cm³) of 0.80 nm or less per gram of carbonaceous material, calculated by the QSDFT method based on the nitrogen adsorption isotherm. 3 / g) is 0.23cm 3 / g or more and 0.35cm 3Carbonaceous materials with a filling density of 0.43 g / mL or more and 0.65 g / mL or less as measured according to Japanese Industrial Standard JIS K1474 (2014), and an Active Black 5 value of 3.0 g / L or more and 60.0 g / L or less.

[0090] When using water vapor, oxygen, and carbon dioxide as active gases, the partial pressure of water vapor is preferably 10% to 30% by volume, more preferably 15% to 25% by volume. The partial pressure of oxygen is preferably 0.5% to 5% by volume, more preferably 1% to 4% by volume. The partial pressure of carbon dioxide is preferably 1% to 10% by volume, more preferably 3% to 7% by volume. It should be noted that inert gases such as nitrogen may also be included as other gases. In this case, the partial pressure of the inert gas is preferably 55% to 88.5% by volume, more preferably 64% to 81% by volume. By keeping their proportions within the above ranges, it is easier to manufacture a pore volume (cm³) of 0.80 nm or less per gram of carbonaceous material, calculated by the QSDFT method based on the nitrogen adsorption isotherm. 3 / g) is 0.23cm 3 / g or more and 0.35cm 3 Carbonaceous materials with a filling density of 0.43 g / mL or more and 0.65 g / mL or less as measured according to Japanese Industrial Standard JIS K1474 (2014), and an Active Black 5 value of 3.0 g / L or more and 60.0 g / L or less.

[0091] When using water vapor and oxygen as active gases, their flow rates are preferably a total of 10 liters (L) or more and 300 liters (L) or less per minute.

[0092] The activation time can be appropriately set according to conditions such as raw materials, activation temperature, and manufacturing equipment. For example, the activation time is 20 minutes or more and 48 hours or less, preferably 30 minutes or more and 36 hours or less, more preferably 40 minutes or more and 24 hours or less, further preferably 45 minutes or more and 480 minutes or less, and even more preferably 50 minutes or more and 360 minutes or less. By keeping the activation time within the above range, it is easier to manufacture a pore volume (cm³) of 0.80 nm or less per 1g of carbonaceous material, calculated using the QSDFT method based on the nitrogen adsorption isotherm. 3 / g) is 0.23cm 3 / g or more and 0.35cm 3Carbonaceous materials with a filling density of 0.43 g / mL or more and 0.65 g / mL or less as measured according to Japanese Industrial Standard JIS K1474 (2014), and an Active Black 5 value of 3.0 g / L or more and 60.0 g / L or less.

[0093] The activation temperature is preferably 750°C or higher and 1200°C or lower, more preferably 800°C or higher and 1100°C or lower, and even more preferably 870°C or higher and 950°C or lower. By keeping the activation temperature within the above range, it is easier to produce a pore volume (cm³) of 0.80 nm or less per 1 g of carbonaceous material, calculated by QSDFT based on the nitrogen adsorption isotherm. 3 / g) is 0.23cm 3 / g or more and 0.35cm 3 Carbonaceous materials with a filling density of 0.43 g / mL or more and 0.65 g / mL or less as measured according to Japanese Industrial Standard JIS K1474 (2014), and an Active Black 5 value of 3.0 g / L or more and 60.0 g / L or less.

[0094] As an activation device for performing activation treatment, examples include... Figure 1 The schematic cross-sectional view of the fluidized bed furnace is shown.

[0095] like Figure 1 As shown, a fluidized bed furnace typically includes: gas inlets 1-4 at the bottom, a flow bed 5 above it, a combustion bed 6 for combustible gases above it, and a gas outlet 8 above it. Gas introduced from the gas inlets 1-4 is transported in the main gas direction A, passing through the flow bed 5 and the combustion bed 6 for combustible gases, and is discharged from the gas outlet 8. Carbides, as raw materials, are loaded into the flow bed 5, and carbonaceous materials are produced by activation within the flow bed 5.

[0096] Gas inlets 1-4 are used to introduce water vapor, oxygen, carbon dioxide, and nitrogen into the fluidized bed furnace. Preferably, gas inlets 1-4 are for water vapor, carbon dioxide, nitrogen, and oxygen, respectively. By configuring gas inlets 1-4 in this way, each gas is introduced into the fluidized bed furnace, thereby allowing for more appropriate activation of the carbide (raw material) and facilitating the easier production of the desired carbonaceous material. It should be noted that... Figure 1 The device is equipped with four gas inlets, but the number of gas inlets can be appropriately set according to factors such as the type of raw material, the degree of activation, and the size of the equipment. Furthermore, the types of gas introduced into gas inlets 1 to 4 can also be appropriately set according to factors such as the type of raw material, the degree of activation, and the size of the equipment.

[0097] like Figure 1 As shown, the fluidized bed furnace preferably includes an oxygen-containing gas inlet 7 for introducing oxygen-containing gas. By introducing oxygen-containing gas into the fluidized bed furnace through the oxygen-containing gas inlet 7, volatile gases can be combusted efficiently. This generates heat of combustion, which is used to further raise the temperature within the flow layer 5, enabling more efficient activation.

[0098] Furthermore, the efficient combustion of volatile gases and oxygen-containing gases prevents excess oxygen from being introduced through gas inlets 1 to 4. As a result, the combustion reaction between oxygen and carbides can be more appropriately suppressed, thus making it easier to control the porosity of carbonaceous materials.

[0099] For this reason, it is easier to manufacture carbonaceous materials with the desired porosity and specific surface area.

[0100] The oxygen-containing gas inlet 7 is located within the fluidized bed furnace at a position that does not contact the upper end of the flow layer 5, preferably at a position that allows oxygen-containing gas to be introduced into the combustion layer 6 of the combustible gas. Furthermore, the orientation of the oxygen-containing gas inlet 7 is preferably parallel to the main gas direction A and opposite to it (i.e., towards the downstream layer side). By configuring the oxygen-containing gas inlet 7 in this way, oxygen-containing gas is appropriately delivered into the combustion layer 6 of the combustible gas, thereby enabling a further increase in temperature within the fluidized bed furnace. This allows for more uniform activation of carbides, thus making it easier to manufacture carbonaceous materials with the desired pore size distribution.

[0101] As for the material used in fluidized bed furnaces, there are no special restrictions, as long as the material is used in fluidized bed furnaces, stainless steel can be used as an example.

[0102] In this way, by using a fluidized bed furnace as the activation device, it is easier to produce pore volumes (cm³) of less than 0.80 nm per 1 g of carbonaceous material, calculated by QSDFT based on nitrogen adsorption isotherms. 3 / g) is 0.23cm 3 / g or more and 0.35cm 3 Carbonaceous materials with a filling density of 0.43 g / mL or more and 0.65 g / mL or less as measured according to Japanese Industrial Standard JIS K1474 (2014), and an Active Black 5 value of 3.0 g / L or more and 60.0 g / L or less.

[0103] The activated material is obtained through the above activation process.

[0104] The manufacturing method of carbonaceous materials may also include a cleaning process for rinsing the activated material and / or a drying process for drying the activated material after the activation process. The conditions in these processes are not particularly limited, and known conditions can be used. Alternatively, the cleaning and drying processes described below can also be referenced.

[0105] (Cleaning process)

[0106] The carbonaceous material is preferably obtained through a cleaning process that cleans the activated material obtained in the activation process. Water washing is more preferred as the cleaning method. This cleaning process makes it easier to produce a pore volume (cm³) per 1g of carbonaceous material with a pore size of 0.80 nm or less, calculated using the QSDFT method based on the nitrogen adsorption isotherm. 3 / g) is 0.23cm 3 / g or more and 0.35cm 3 Carbonaceous materials with a filling density of 0.43 g / mL or more and 0.65 g / mL or less as measured according to Japanese Industrial Standard JIS K1474 (2014), and an Active Black 5 value of 3.0 g / L or more and 60.0 g / L or less.

[0107] The temperature and time during cleaning should be adjusted appropriately to obtain the desired carbonaceous material.

[0108] (Drying process)

[0109] The carbonaceous material is preferably obtained by a drying process in which the cleaned material obtained in the cleaning process is dried.

[0110] There are no particular limitations on the drying method; known drying methods such as natural drying, heated drying, and hot air drying can be used. Heating and / or depressurization are preferred methods. From the viewpoint of achieving uniform and stable drying, hot air drying is preferred as a heating method. In the drying process, it is preferable to dry the carbonaceous material until the moisture content is 20.0% by mass or less, more preferably until the moisture content is 10.0% by mass or less.

[0111] Examples of heating methods include those using the following dryers: static constant temperature dryer; static hot air dryer; vacuum dryer; rotary evaporator; conical dryer; Nota dryer; and other mixed dryers. The heating temperature should be such that the carbonaceous material solidifies without melting, preferably between 40°C and 300°C.

[0112] Examples of pressure reduction methods include those using oil pumps, oilless pumps, and suction devices. The pressure in these methods is typically between 0.00001 MPa and 0.05 MPa.

[0113] The drying time varies depending on the drying temperature, and is usually between 1 minute and 20 hours.

[0114] The resulting carbonaceous material can be used directly or, as needed, by using known methods to adjust the particle size through crushing, pulverizing, and grading; by using additional cleaning with, for example, water, organic solvents, acidic aqueous solutions, and alkaline aqueous solutions to improve purity; and by using additional heat treatment to impart durability and adjust the structure, thus obtaining the carbonaceous material.

[0115] [use]

[0116] Carbonaceous materials can be suitably used for various applications involving the removal, adsorption, concentration, and recovery of butanes. Such applications can also involve appropriately combining removal, adsorption, concentration, and recovery operations. Examples of such applications include adsorption filters and packed columns.

[0117] Carbonaceous materials are suitable for adsorbing at least one butane selected from the group consisting of n-butane, isobutane, 1,2-butadiene, and 1,3-butadiene. Carbonaceous materials are more suitable for adsorbing at least one selected from the group consisting of n-butane and isobutane, and are further suitable for adsorbing n-butane.

[0118] [Adsorption methods for butanes]

[0119] The butane adsorption method includes an adsorption step of adsorbing butane onto a carbonaceous material. Examples of methods for adsorbing butane include adsorbing butane onto a carbonaceous material to concentrate the butane within the carbonaceous material. In the concentration method, in addition to using the carbonaceous material described in this embodiment, the same steps as known butane adsorption, concentration, and recovery methods may be employed.

[0120] In the adsorption process, for example, butanes are brought into contact with carbonaceous materials, thereby causing the carbonaceous materials to adsorb butanes.

[0121] [Apparatus]

[0122] The device is made of carbonaceous material. Besides using the carbonaceous material of this embodiment, the device may also have the same structure as known devices.

[0123] The function of the carbonaceous material is utilized by an apparatus containing the carbonaceous material. The apparatus is preferably a processing apparatus. It should be noted that, in this specification, "processing apparatus" is not particularly limited to any apparatus capable of removing, adsorbing, concentrating, and recovering butane compounds contained in VOCs, etc., using the carbonaceous material of this embodiment. Such a processing apparatus can also be an apparatus that appropriately combines the operations of removal, adsorption, concentration, and recovery. Examples of such processing apparatuses include: an apparatus containing carbonaceous material, comprising an adsorption filter, column, tank or bath, tube, filter element, cylinder, and sheet (hereinafter also simply referred to as "filters containing carbonaceous material, etc."), an adsorption apparatus, and a concentration apparatus.

[0124] The apparatus, for example, includes an adsorption section for contacting carbonaceous materials with butanes. The adsorption section may, as needed, include adsorption materials other than the carbonaceous materials described in this embodiment. Examples of such adsorption materials include activated carbon, zeolite, silica gel, activated alumina, nonwoven fabric, and porous organic compounds, other than the carbonaceous materials described in this embodiment.

[0125] The treatment device may include an adsorption filter containing carbonaceous material, as well as other adsorption filters. Examples of such other adsorption filters include: metal filters made of stainless steel, aluminum, bronze, copper, titanium, and nickel; and resin filters made of polypropylene, polyvinyl chloride, polyvinylidene chloride, polyethylene, polyamide, and fluoropolymers.

[0126] In addition, the processing device can be intermittent or continuous, and carbonaceous materials can be used in either mode.

[0127] [Adsorption Filter]

[0128] The adsorption filter of this embodiment contains the carbonaceous material of this embodiment. Furthermore, the adsorption filter is preferably an adsorption filter for automobiles.

[0129] Because adsorption filters contain carbonaceous materials, they exhibit high adsorption performance for butanes. Therefore, for example, by installing adsorption filters in automobiles, butanes suspended in the vehicle's interior space can be removed efficiently.

[0130] The adsorption filter preferably comprises carbonaceous material and fibrous binder.

[0131] Examples of fibrous binders include those capable of winding and shaping carbonaceous materials through fibrillation. Such fibrous binders can be either synthetic or natural. Examples of fibrous binders include acrylic fibers, polyethylene fibers, polypropylene fibers, polyacrylonitrile fibers, cellulose fibers, nylon fibers, aramid fibers, and pulp.

[0132] The fibrous binder can be used alone or in combination of two or more. Preferred fibrous binders are polyacrylonitrile fibers and / or pulp. Using these fibrous binders can further improve the density and strength of the adsorption filter, and suppress performance degradation.

[0133] From the viewpoint of obtaining carbonaceous materials with higher adsorption performance for butanes, the adsorption filter preferably contains 20 parts by mass or less of a fibrous binder relative to 100 parts by mass of the carbonaceous material, more preferably 10 parts by mass or less of a fibrous binder. As a lower limit, it is typically 0.01 parts by mass or more.

[0134] It should be noted that, in cases where the adsorption filter contains other functional components described later, the phrase "100 parts by mass relative to the carbonaceous material" regarding the filter composition should be replaced with "100 parts by mass relative to the total of the carbonaceous material and other functional components".

[0135] The adsorption filter may also contain other functional components, provided that the effectiveness of this embodiment is not impaired. Examples of such other functional components include: lead adsorption materials such as titanosilicon and zeolite powders capable of adsorbing and removing dissolved lead; ion exchange resins; chelating resins; and various adsorption materials containing silver ions and / or silver compounds to impart antibacterial properties.

[0136] [Automotive Adsorption Filter]

[0137] The automotive adsorption filter of this embodiment includes the carbonaceous material of this embodiment. Besides including the carbonaceous material of this embodiment, the automotive adsorption filter may also have the same structure as known automotive adsorption filters. Because the automotive adsorption filter includes the carbonaceous material, it exhibits high adsorption performance for butanes. Therefore, for example, by installing the adsorption filter in a car, butanes suspended in the vehicle's interior space can be removed efficiently.

[0138] Example

[0139] The following examples and comparative examples illustrate the present invention in more detail, but the present invention is not limited to these examples.

[0140] [Evaluation Method]

[0141] (1) Pore volume with a pore size of less than 0.80 nm

[0142] Measurements using the BELSORP-MAX nitrogen adsorption isotherm

[0143] Using a specific surface area / pore distribution measuring device (BELSORP (registered trademark) - MAX (trade name) manufactured by MicrotracBEL Corp.), the nitrogen adsorption isotherm was measured at a temperature of 77K after heating the carbonaceous material at 300°C for 3 hours under vacuum conditions.

[0144] Measurement of pore volume

[0145] The pore volume (cm³) of carbonaceous material with a pore size of less than 0.80 nm per 1 g of micropores, calculated by QSDFT method based on nitrogen adsorption isotherms. 3 The pore size distribution is calculated as follows. Specifically, using the nitrogen adsorption isotherm values ​​obtained through the aforementioned "measurement using BELSORP-MAX nitrogen adsorption isotherms," ​​the pore size distribution is calculated using N2 at 77K carbon [slit pore / cyl.pore (QSDFT Ads.model)] as the calculation model. From this, the pore volume (cm³) for pore sizes below 0.80 nm is calculated. 3 / g).

[0146] (2) Filling density

[0147] The filling density (g / mL) of the carbonaceous material was measured according to Japanese Industrial Standard JIS K1474 (2014). Specifically, the carbonaceous material was first dried in a constant-temperature desiccator (Yamato Scientific Co., Ltd. DVS402 (trade name)) at 115±5℃ for 3 hours. Then, it was naturally cooled to room temperature in a desiccant-based dryer to obtain naturally cooled carbonaceous material. The naturally cooled carbonaceous material was then transferred into the storage funnel of a filling density measuring container (manufactured by ToyoMachine Manufacturing Co., Ltd., model TD-V5 (trade name)), and the carbonaceous material was filled to the 100mL mark of the filling density measuring container using the attached vibrator. The mass of the filled carbonaceous material was measured to an accuracy of 0.1g.

[0148] (3) Active Black 5-value

[0149] The Reactive Black 5 value (g / L) was measured using carbonaceous materials.

[0150] Specifically, firstly, the carbonaceous material is pulverized to approximately 10.0 μm or less, representing 50% of the cumulative particle size (D50) based on a volumetric criterion, and then dried for 3 hours in a constant-temperature dryer (Yamato Scientific Co., Ltd., DVS402 (trade name)) at 115°C. Then, it is naturally cooled to room temperature in a dryer using silica gel as a desiccant to obtain the naturally cooled carbonaceous material.

[0151] On the other hand, test solution A, containing phosphate buffer and Reactive Black 5 (manufactured by Sigma-Aldrich Co. LLC), was prepared as follows: First, 7.26 g of potassium dihydrogen phosphate (manufactured by FUJIFILM Wako Pure Chemical Corporation) and 28.66 g of disodium hydrogen phosphate dodecahydrate (manufactured by FUJIFILM Wako Pure Chemical Corporation) were dissolved in 2 L of distilled water to prepare phosphate buffer (pH: 7.0). Then, Reactive Black 5 was added to 1 L of the obtained phosphate buffer at a concentration of approximately 0.5 g to 1.2 g to prepare test solution A. It should be noted that the amount of Reactive Black 5 was adjusted as follows: The amount of Reactive Black 5 added to 1 L of phosphate buffer was appropriately adjusted so that the absorbance of the solution after diluting test solution A 20 times 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 cuvette with a 10 mm optical path length and a UV-Vis spectrophotometer (Hitachi High-Tech Corporation U-2910 double-beam spectrophotometer). It should be noted that the solution obtained above, diluted 20 times with test solution A, was used as test solution B, and this test solution B was used for the absorbance measurement described below.

[0152] Next, in a 100 mL Erlenmeyer flask with a stopper, take an arbitrary mass (calculated by formula (II) below, the residual percentage of Reactive Black 5 in the filtrate being approximately 10%) of the naturally cooled carbonaceous material described above, and add this carbonaceous material to 50 mL of the prepared test solution A. Using a shaking thermostat (TAITEC CORPORATION MM-10 water bath shaker, trade name), shake at 150 times / minute for 5 hours in a 40°C water bath to obtain a mixture. Then, filter the mixture using a membrane filter (Advantec Toyo Kaisha, Ltd. DISMIC 25HP045AN, trade name), thereby obtaining the filtrate.

[0153] Using a 10 mm glass cuvette, the absorbance of the obtained test solution B and filtrate was measured at a wavelength of 594 nm using a UV-Vis spectrophotometer (Hitachi High-Tech Corporation U-2910 double-beam spectrophotometer). Using these absorbances, the adsorption amount of Reactive Black 5 per 1 g of carbonaceous material was calculated using the following formula (I) (hereinafter referred to as "RB5 adsorption amount per 1 g of carbonaceous material ( / g)").

[0154] The RB5 adsorption capacity per 1g of carbonaceous material ( / g) = (Absorbance of test solution B at 594nm wavelength × 20 - Absorbance of filtrate at 594nm wavelength) / Mass of carbonaceous material (g) ... (I)

[0155] In addition, the residual rate of Reactive Black 5 contained in the filtrate (hereinafter referred to as "RB5 residual rate (%)") is calculated by the following formula (II).

[0156] RB5 residue rate (%) = (absorbance of filtrate at 594 nm / absorbance of test solution B at 594 nm × 20) × 100… (II)

[0157] Next, a power function approximation curve was constructed with the RB5 residual rate (%) as the horizontal axis and the RB5 adsorption amount per 1g of carbonaceous material ( / g) as the vertical axis. Using its power function approximation, the adsorption amount of Reactive Black 5 at a residual rate of 1% was calculated (hereinafter referred to as "RB5 adsorption amount ( / g) at a residual rate of 1%"), and the Reactive Black 5 value (g / L) was calculated using equation (III).

[0158] Reactive Black 5 value (g / L) = (Absorbance of test solution B at wavelength 594nm × 20 × 0.99 / Adsorption amount of RB5 at 1% RB5 residue ( / g)) / 0.05 (L) ... (III)

[0159] It should be noted that 0.05 (L) in formula (III) is the amount of test solution.

[0160] (4) Iodine adsorption capacity (iodine adsorption performance)

[0161] The iodine adsorption capacity (mg / g) of carbonaceous materials was measured and calculated.

[0162] Specifically, the iodine adsorption capacity was measured according to Japanese Industrial Standard JIS K1474 (2014). First, according to Japanese Industrial Standard JIS Z 8801-1, the carbonaceous material was pulverized until more than 90% of it could pass through a 45μm sieve, and then dried for 3 hours in a constant-temperature dryer (Yamato Scientific Co., Ltd. DVS402 (trade name)) at 115°C. Then, it was naturally cooled to room temperature in a dryer using silica gel as a desiccant to obtain the naturally cooled carbonaceous material.

[0163] On the other hand, 25.0 g of potassium iodide (manufactured by FUJIFILM Wako Pure Chemical Corporation) and 13.0 g of iodine (manufactured by FUJIFILM Wako Pure Chemical Corporation) were dissolved in about 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 Corporation), and distilled water was added appropriately to prepare a 0.05 mol / L iodine solution.

[0164] Next, weigh an arbitrary amount (enough to make the residual iodine concentration in the supernatant of the filtrate approximately 2.5 g / L) of the naturally cooled carbonaceous material and place it in a stoppered 100 mL Erlenmeyer flask. Then, using a full-volume pipette, add 50 mL of the aforementioned 0.05 mol / L iodine solution. At room temperature (above 20°C and below 30°C), shake the mixture at 200 vibrations per minute for 15 minutes using a shaker (TAITECCORPORATION Recipro Shaker NR-10, a medium-sized shaker, trade name) to allow the carbonaceous material to adsorb iodine, resulting in a mixture. Then, filter the mixture using a mixed cellulose ester membrane filter (Advantec ToyoKaisha, Ltd., A045A025A, trade name) to obtain the filtrate. Take 10 mL of the supernatant from the filtrate using a full-volume pipette, titrate it with 0.1 mol / L sodium thiosulfate solution (prepared by FUJIFILM Wako Pure Chemical Corporation, correction factor: 1.000), and calculate the residual iodine concentration using the following formula (IV).

[0165] Iodine residual concentration (g / L) = Volume of 0.1 mol / L sodium thiosulfate solution used for titration (mL) × Correction factor of 0.1 mol / L sodium thiosulfate solution × 12.69 / 10… (IV)

[0166] The amount of iodine adsorbed per 1g of carbonaceous material can be calculated using the following formula (V).

[0167] Iodine adsorption capacity per 1g of carbonaceous material = (Correction factor of 10 × 0.05 mol / L iodine solution - Volume of 0.1 mol / L sodium thiosulfate solution used for titration (mL) × Correction factor of 0.1 mol / L sodium thiosulfate solution) × 12.69 × 5 / Mass of carbonaceous material (g) ... (V)

[0168] It should be noted that the correction factor for the 0.05 mol / L iodine solution is calculated using equation (VI).

[0169] The correction factor for a 0.05 mol / L iodine solution = (volume of 0.1 mol / L sodium thiosulfate solution used for titration (mL) × correction factor for 0.1 mol / L sodium thiosulfate solution) / 10… (VI)

[0170] Based on the Freundlich adsorption isotherm, an adsorption isotherm was constructed with the iodine residual concentration on the horizontal axis and the iodine adsorption amount per 1g of carbonaceous material on the vertical axis. The iodine adsorption amount per 1g of carbonaceous material (mg / g) when the iodine residual concentration is 2.5g / L was calculated. This iodine adsorption amount was taken as the iodine adsorption performance.

[0171] (5) Average pore size of micropores

[0172] Measurement of specific surface area with pore size below 2.0 nm

[0173] The specific surface area (m²) of micropores with a pore size of less than 2.0 nm per 1 g of carbonaceous material, calculated using the QSDFT method. 2 / g) is calculated using the nitrogen adsorption isotherm obtained in the above-mentioned item "(1) Pore volume with a pore size of less than 0.80 nm". Specifically, using the value of the nitrogen adsorption isotherm obtained by the above-mentioned "Measurement of nitrogen adsorption isotherm using BELSORP-MAX", the pore size distribution is calculated by applying N2 at 77 K carbon [slit pore / cyl.pore (QSDFTAds.model)] as the calculation model, and thus the specific surface area (m²) of micropores with a pore size of less than 2.0 nm is calculated. 2 / g).

[0174] Measurement of pore volume with a pore size of less than 2.0 nm

[0175] The pore volume (cm³) of micropores with a pore size of less than 2.0 nm per 1g of carbonaceous material, calculated using the QSDFT method. 3 / g) is calculated using the nitrogen adsorption isotherm obtained in the above-mentioned item "(1) Pore volume with a pore size of less than 0.80 nm". Specifically, using the value of the nitrogen adsorption isotherm obtained by the above-mentioned "Measurement of nitrogen adsorption isotherm using BELSORP-MAX", the pore size distribution is calculated by applying N2 at 77K carbon [slit pore / cyl.pore (QSDFT Ads.model)] as the calculation model, and thus, the pore volume (cm) with a pore size of less than 2.0 nm is calculated. 3 / g).

[0176] Method for calculating the average pore size of micropores

[0177] The average pore diameter (nm) of the micropores in the carbonaceous material is calculated using the specific surface area and pore volume of the micropores obtained above, by the following formula (VII).

[0178] Average pore diameter (nm) of micropores = (pore volume of micropores (cm³)) 3 / g) / Specific surface area of ​​micropores (m²) 2 / g))×2000…(VII)

[0179] (6) The proportion of pore volume with a pore size of less than 0.80 nm

[0180] The percentage (%) of pore volume with a pore size of less than 0.80 nm in carbonaceous materials was calculated.

[0181] Specifically, the percentage (%) of pore volume with a pore size of 0.80 nm or less in carbonaceous materials is the pore volume (cm³) with a pore size of 0.80 nm or less obtained from the item “(1) Pore volume with a pore size of 0.80 nm or less” above. 3 / g) and the pore volume (cm³) with a pore size of less than 2.0 nm obtained in the above item "(6) Average pore size of micropores". 3 / g), calculated using the following formula (VIII).

[0182] The percentage of pore volume with a pore size of 0.80 nm or less (%) = the total pore volume with a pore size of 0.80 nm or less (cm³) 3 / g) / Pore volume (cm³) with a pore size of less than 2.0 nm 3 / g)×100…(VIII)

[0183] (8) n-Butane adsorption capacity (n-Butane adsorption performance)

[0184] The n-butane adsorption capacity (mg / g) of carbonaceous materials was measured and calculated.

[0185] Specifically, firstly, following Japanese Industrial Standard JIS Z8801-1, the carbonaceous material was sieved using a test sieve to a particle size range of 0.600 mm to 0.250 mm with a nominal sieve aperture size, ensuring uniform particle size. The sieved carbonaceous material was then dried for 3 hours in a constant-temperature desiccator (Yamato Scientific Co., Ltd. DVS402 (trade name)) at 115±5℃. Finally, it was naturally cooled to room temperature in a dryer using silica gel as a desiccant, yielding naturally cooled carbonaceous material.

[0186] Next, 0.492 g of naturally cooled carbonaceous material was filled into a glass column (manufactured by IwataGlass Industrial Co., Ltd.) with an inner diameter of 28 mm. Then, the filled glass column was placed in a thermostatic bath (manufactured by ADVANTEC LF-681 (trade name)) maintained at 25°C, and water vapor adjusted to a relative humidity of 50% RT was circulated into the glass column at a flow rate of 7.39 L / min for 30 minutes for pretreatment.

[0187] Then, the pretreated glass column was placed in a gas chromatograph (Shimadzu Corporation GC-2014, trade name) and n-butane gas (concentration: 80 ppm) adjusted to a relative humidity of 50% RT was used as the test gas, flowing into the column at a flow rate of 7.3 L / min. The n-butane gas concentration before and after column passage was measured, and the penetration rate of the n-butane concentration (C) after column passage (C0) relative to the n-butane concentration before column passage (C0) was calculated. This experiment was conducted until the penetration rate reached 95%. It should be noted that the penetration rate was calculated using the following formula (IX).

[0188] Penetration rate (%) = n-Butane concentration after column passage (C) / n-Butane concentration before column passage (C0) × 100… (IX)

[0189] Based on the n-butane adsorption capacity (mg) at a penetration rate of 95% and the amount of carbonaceous material packed into the glass column, the n-butane adsorption capacity (mg / g) per 1g of carbonaceous material is calculated using the following formula (X). This n-butane adsorption capacity is taken as the n-butane adsorption performance.

[0190] n-Butane adsorption capacity (mg / g) = n-Butane adsorption capacity (mg) when breakthrough reaches 95% / Amount of carbonaceous material packed into the glass column (g) ... (X)

[0191] [Example 1]

[0192] (Carbonization process)

[0193] Coconut shells from the Philippines were carbonized at 600°C for about 2 hours and then crushed. They were then sieved using a standard metal mesh as specified in Japanese Industrial Standard JIS Z8801-1:2019. The particle size was adjusted so that it did not pass through 70 mesh (sieve aperture size: 243 μm, manufactured by Nishimura Kinzoku Co., Ltd.) but passed through 14 mesh (sieve aperture size: 1.31 mm, manufactured by Nishimura Kinzoku Co., Ltd.) so that the particle size (50% particle size in the cumulative distribution based on volume, D50) was 405 μm, thereby obtaining granular carbonized material.

[0194] (Activation treatment)

[0195] The resulting carbide is then put into... Figure 1 The fluidized bed furnace, as shown, was heated to 900°C. Then, active gases (20% by volume of water vapor, 2% by volume of oxygen, 5% by volume of carbon dioxide, and 73% by volume of nitrogen) were introduced into the fluidized bed furnace for activation treatment for 110 minutes, thereby obtaining the activated product.

[0196] (Cleaning and drying processes, etc.)

[0197] The activated material is thoroughly washed with water and dried to obtain a dried material. Then, the dried material is pulverized to obtain pulverized carbonaceous material 1 as activated carbon.

[0198] [Example 2]

[0199] In the activation process, the activation treatment is carried out for 130 minutes, otherwise the same as in Example 1, to obtain pulverized carbonaceous material 2 as activated carbon.

[0200] [Example 3]

[0201] In the activation process, the activation treatment is carried out for 170 minutes, otherwise the same as in Example 1, to obtain pulverized carbonaceous material 3 as activated carbon.

[0202] [Example 4]

[0203] In the activation process, the activation treatment is carried out for 190 minutes, otherwise the same as in Example 1, to obtain pulverized carbonaceous material 4 as activated carbon.

[0204] [Example 5]

[0205] In the activation process, the activation treatment is carried out for 205 minutes, otherwise the same as in Example 1, to obtain pulverized carbonaceous material 5 as activated carbon.

[0206] [Example 6]

[0207] In the activation process, the activation treatment is carried out for 225 minutes, otherwise the same as in Example 1, to obtain pulverized carbonaceous material 6 as activated carbon.

[0208] [Example 7]

[0209] In the activation process, the activation treatment is carried out for 90 minutes, otherwise the same as in Example 1, to obtain pulverized carbonaceous material 7 as activated carbon.

[0210] [Example 8]

[0211] In the activation process, the activation treatment is carried out for 240 minutes, otherwise the same as in Example 1, to obtain pulverized carbonaceous material 8 as activated carbon.

[0212] [Example 9]

[0213] In the activation process, the activation treatment is carried out for 300 minutes, otherwise the same as in Example 1, to obtain pulverized carbonaceous material 9 as activated carbon.

[0214] [Comparative Example 1]

[0215] (Carbonization process)

[0216] Coconut shells from the Philippines were carbonized at 600°C for about 2 hours and then crushed. They were then sieved using a standard metal mesh as specified in Japanese Industrial Standard JIS Z8801-1:2019. The particle size was adjusted so that it did not pass through 70 mesh (sieve aperture size: 243 μm, manufactured by Nishimura Kinzoku Co., Ltd.) but passed through 14 mesh (sieve aperture size: 1.31 mm, manufactured by Nishimura Kinzoku Co., Ltd.) so that the particle size (50% particle size in the cumulative distribution based on volume, D50) was 405 μm, thereby obtaining granular carbonized material.

[0217] (Activation treatment)

[0218] The resulting carbides were placed in a volume of 1 m³ relative to the rotary kiln. 3 Approximately 0.06 times the volume of the active gas was introduced into a rotary kiln heated to 900°C and equipped with stirring blades. Then, while rotating the kiln at 3.0 rpm, the active gas (35% by volume of water vapor, 5% by volume of oxygen, 5% by volume of carbon dioxide, and 55% by volume of nitrogen) was introduced into the kiln and immediately removed, thereby obtaining the activated product.

[0219] (Cleaning and drying processes, etc.)

[0220] The activated material is thoroughly washed with water and dried to obtain a dried material. Then, the dried material is pulverized to obtain pulverized carbonaceous material 10 as activated carbon.

[0221] [Comparative Example 2]

[0222] In the activation process, the activation treatment was carried out for 170 minutes. Otherwise, it was the same as Comparative Example 1, and a pulverized carbonaceous material 11 as activated carbon was obtained.

[0223] [Comparative Example 3]

[0224] In the activation process, the activation treatment was carried out for 220 minutes. Otherwise, it was the same as Comparative Example 1, and a pulverized carbonaceous material 12 as activated carbon was obtained.

[0225] [Comparative Example 4]

[0226] (Carbonization process)

[0227] Wood flour from Japan and Malaysia was carbonized at 600°C for about 2 hours and then pulverized. It was then sieved using a standard metal mesh sieve as specified in Japanese Industrial Standard JIS Z8801-1:2019. The particle size was adjusted so that it did not pass through 20 mesh (sieve aperture size: 870 μm, manufactured by Nishimura Kinzoku Co., Ltd.) but passed through 10 mesh (sieve aperture size: 1.54 mm, manufactured by Nishimura Kinzoku Co., Ltd.) so that the particle size (50% particle size in the cumulative distribution based on volume, D50) was 1451 μm, thereby obtaining granular carbides.

[0228] (Activation treatment)

[0229] The resulting carbides were placed in a volume of 1 m³ relative to the rotary kiln. 3 Approximately 0.06 times the volume of the mixture was added to a rotary kiln preheated to 850°C and equipped with stirring blades. Then, while rotating the kiln at 3.0 rpm, active gases (50% by volume water vapor, 10% by volume oxygen, 35.0% by volume carbon dioxide, and 5.0% by volume nitrogen) were introduced into the kiln for activation treatment until the specific surface area reached 1080 m². 2 Up to / g, the activated product is obtained.

[0230] (Cleaning and drying processes, etc.)

[0231] The 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 dried material was then pulverized to obtain pulverized carbonaceous material 13 as activated carbon.

[0232] [Comparative Example 5]

[0233] In the activation process of Example 1, the time was changed from 110 minutes to 225 minutes, and the granular carbide obtained in Example 1 was activated. The obtained activated material was pulverized and then sieved using a standard metal mesh as specified in Japanese Industrial Standard JIS Z8801-1:2019. The particle size was adjusted to pass through 30 mesh (sieve size: 550 μm, manufactured by Nishimura Kinzoku Co., Ltd.) but not through 60 mesh (sieve aperture size: 243 μm) so that the particle size (50% particle size in the cumulative distribution based on volume, D50) was 334 μm, thereby obtaining granular activated material.

[0234] Then, the obtained activated material was impregnated in 0.5N hydrochloric acid preheated to 95°C, and allowed to stand at 95°C for 20 minutes while heating. Next, the impregnated activated material was washed with water until the pH reached approximately 6-7, and then dried until the water content of the activated material was below 3% by mass, thus obtaining dried activated carbon. It should be noted that the specific surface area of ​​the dried activated carbon is 1050 m² / s. 2 / g. Next, the dried activated carbon was sprayed with an 18% by mass aqueous solution of p-aminobenzenesulfonic acid (p-aminobenzenesulfonic acid: manufactured by FUJIFILM Wako Pure Chemical Corporation, reagent grade: extra grade, containing 0.95 moles of sodium hydroxide per mole of p-aminobenzenesulfonic acid) to adsorb the p-aminobenzenesulfonic acid onto the activated carbon, thereby obtaining adsorbed product 1. The obtained adsorbed product 1 was placed at room temperature for 30 minutes, and then sprayed with a 46% by mass aqueous solution of citric acid to adsorb the citric acid onto the activated carbon, thereby obtaining adsorbed product 2. The obtained adsorbed product 2 was placed at room temperature for 60 minutes, thereby obtaining impregnated carbon. Next, the impregnated carbon was dried in a constant temperature dryer (Yamato Scientific Co., Ltd. DVS402 (trade name)) at 90°C for 24 hours, thereby obtaining carbonaceous material 14 as impregnated carbon (containing 8.0 parts by mass of p-aminobenzenesulfonic acid and 4.4 parts by mass of citric acid per 100 parts of activated carbon).

[0235] [Table 1]

[0236]

[0237] -Industry Applicability-

[0238] The carbonaceous material of this embodiment can be appropriately used for various applications of removing, adsorbing, concentrating, and recovering butanes.

[0239] This application is based on Japanese Patent Application No. 2023-201660, filed on November 29, 2023, the contents of which are incorporated herein by reference.

[0240] - Explanation of figure labels -

[0241] A…Main direction of gas, 1, 2, 3, 4…Gas inlet, 5…Flow layer, 6…Combustion layer of combustible gas, 7…Oxygen-containing gas inlet, 8…Gas outlet.

Claims

1. A carbonaceous material, characterized in that: The pore volume (cm³) of carbonaceous material with a pore size of less than 0.80 nm per 1g, calculated by QSDFT method based on nitrogen adsorption isotherms. 3 / g) is 0.23cm 3 / g or more and 0.35cm 3 The filling density, measured according to the 2014 Japanese Industrial Standard JIS K1474, is 0.43 g / mL or more and 0.65 g / mL or less, and the Active Black 5 value is 3.0 g / L or more and 60.0 g / L or less.

2. The carbonaceous material according to claim 1, characterized in that: The iodine adsorption capacity is above 710 mg / g and below 1500 mg / g.

3. The carbonaceous material according to claim 1, characterized in that: The proportion of pore volume with a pore size of 0.80 nm or less is 61% or more and 92% or less.

4. The carbonaceous material according to claim 1, characterized in that: The average pore size of the micropores is above 0.60 nm and below 0.80 nm.

5. The carbonaceous material according to any one of claims 1 to 4, characterized in that: The carbonaceous material is used to adsorb at least one selected from the group consisting of n-butane, isobutane, 1,2-butadiene and 1,3-butadiene.

6. A method for manufacturing a carbonaceous material, characterized in that: The carbonaceous material is the carbonaceous material according to any one of claims 1 to 4. The manufacturing method includes: a carbonization step of carbonizing raw materials to obtain a carbide, and an activation step of activating the carbide to obtain an activated product.

7. The manufacturing method according to claim 6, characterized in that: The manufacturing method further includes a cleaning step for cleaning the activated material.

8. The manufacturing method according to claim 6, characterized in that: The raw material is coconut shell.

9. An adsorption filter, characterized in that: The adsorption filter comprises the carbonaceous material according to any one of claims 1 to 4.

10. The adsorption filter according to claim 9, characterized in that: The adsorption filter is an automotive adsorption filter.

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