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

Abstract

To provide a carbonaceous material with high performance of adsorbing butanes, a method for producing the same, and an adsorption filter.SOLUTION: 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 by a QSDFT method per 1 g of the carbonaceous material from the nitrogen adsorption isotherm is from 0.23 cm3 / g to 0.35 cm3 / g inclusive, the packing density as determined in accordance with JIS K1474 (2014) is from 0.43 g / mL to 0.65 g / mL inclusive, and the reactive black 5 value is from 3.0 g / L to 60.0 g / L inclusive.SELECTED DRAWING: Figure 1

Description

Technical Field

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

Background Art

[0002] Volatile organic compounds (VOCs) in automotive exhaust gases not only contain harmful substances such as aldehydes but also cause the generation of harmful substances through photochemical reactions. Examples of VOCs with high emissions that easily cause 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 simply as "butanes"). Butanes flow into the vehicle interior in the driving environment, causing adverse effects on the health of the driver and discomfort due to odors. Therefore, automobiles are usually equipped with automotive filters incorporating activated carbon as an adsorbent for these substances.

[0003] As an adsorbent for such filters, for example, in Patent Document 1, a composite gas adsorbent is described in which an aromatic aminosulfonic acid and a specific organic acid are attached in a predetermined amount to activated carbon having a BET specific surface area of 700 m 2 / g or more and 1300 m 2 / g or less. The adsorbent of Cited Document 1 is intended for adsorbing a composite gas containing aldehydes and butanes.

Prior Art Documents

Patent Documents

[0004]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0005] However, in the adsorbent of Patent Document 1, although acetaldehyde obtains high removal performance by the adhering substance regardless of the adsorption characteristics of activated carbon, butane obtains the removal performance by controlling only the specific surface area which is the adsorption characteristic of activated carbon. However, by controlling only the specific surface area, small micropores effective for butane adsorption cannot be controlled, and high butane removal performance cannot be obtained.

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

Means for Solving the Problems

[0007] As a result of intensive studies to achieve the above object, the present inventors have found that a carbonaceous material in which the pore volume, the packing density, and the reactive black pentavalent are respectively in specific ranges has high adsorption performance for butanes, and have completed the present invention.

[0008] The present invention includes the following embodiments. [1] A carbonaceous material having a pore volume (cm 3 / g) of pores 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 of 0.23 cm 3 / g or more and 0.35 cm 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 amount of 710 mg / g or more and 1,500 mg / g or less.

[0010] [3] The carbonaceous material according to [1], wherein the ratio of the pore volume of pores with 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 adsorption of 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 carbide, and an activation step of subjecting the carbide to an activation treatment to obtain an activated product.

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

[0015] [8] The production method according to [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 an automobile.

Advantages of the Invention

[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.

Brief Description of the Drawings

[0019]

Figure 1

Embodiments for Carrying Out the Invention

[0020] Hereinafter, embodiments for implementing the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. Note that the following present embodiment is an exemplification for explaining the present invention, and the present invention is not limited to only the present embodiment.

[0021] [Carbonaceous material] The carbonaceous material of the present embodiment has a pore volume (cm 3 / g) of 0.23 cm 3 / g or more and 0.35 cm 3 / g or less calculated by the QSDFT method per 1 g of the carbonaceous material from the nitrogen adsorption isotherm, 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 5 value of 3.0 g / L or more and 60.0 g / L or less.

[0022] By having such requirements, the carbonaceous material has high adsorption performance for butanes. Therefore, the carbonaceous material of the present embodiment is suitable for an adsorption filter for removing butanes. Examples of butanes include butane 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 3 / g) 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 (hereinafter also simply referred to as "pore volume with a pore diameter of 0.80 nm or less") is 0.23 cm 3 / g or more and 0.35 cm 3 / g or less. Since the carbonaceous material has a pore volume with a pore diameter of 0.80 nm or less within a specific range, it has excellent adsorption performance for butanes with a relatively small molecular size. That is, when the pore volume with a pore diameter of 0.80 nm or less is 0.23 cm 3 / g or more, a small pore volume suitable for removing substances with a relatively small molecular size is sufficient, and the adsorption performance for butanes is significantly improved. Also, when the pore volume with a pore diameter of 0.80 nm or less is 0.35 cm 3By being below / g, the abundance of the pore volume suitable for substances smaller than the molecular size of butanes decreases, and accordingly, the pore volume suitable for butanes increases. Therefore, the adsorption performance for butanes is remarkably improved.

[0024] In this specification, the pores of the carbonaceous material conform to the classification criteria of IUPAC (International Union of Pure and Applied Chemistry), and according to the pore diameter (diameter), pores with a pore diameter of less than 2.0 nm are classified as micropores, pores with a pore diameter of 2.0 nm or more and 50.0 nm or less are classified as mesopores, and pores with a pore diameter exceeding 50.0 nm are classified as macropores. Micropores are pores smaller than mesopores and are effective for the adsorption of butanes with a relatively small molecular size.

[0025] In this specification, the pore volume with a pore 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 capable of calculating the pore diameter distribution of about 0.5 nm or more and about 40 nm or less, targeting the pore diameter analysis of geometrically and chemically irregular microporous and mesoporous carbons. Since the QSDFT method clearly considers the influence of the roughness and non-uniformity of the pore surface, it is a method with a significantly improved accuracy of pore diameter distribution analysis. For the specific measurement and calculation method of the pore volume with a pore diameter of 0.80 nm or less, reference may be made to the examples.

[0026] The pore volume with a pore diameter of 0.80 nm or less is preferably 0.235 cm 3 / g or more and 0.300 cm 3 / g or less, and more preferably 0.240 cm 3 / g or more and 0.270 cm 3 / g or less. When the range of the pore volume with a pore diameter 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 the carbonaceous material, the bulk density measured in accordance with JIS K1474 (2014) (hereinafter, also simply referred to as "bulk density") is 0.43 g / mL or more and 0.65 g / mL or less. The bulk density is greatly affected by the pore volume of the carbonaceous material. Therefore, when the bulk density is measured using a carbonaceous material in which the 50% particle diameter (D50) of the cumulative distribution based on volume is adjusted to 9.0 μm or more and 11.0 μm or less, the value of the bulk density serves as an index of the pore volume possessed by the carbonaceous material. When the bulk density is within the above range, the carbonaceous material tends to achieve a higher level of adsorption performance for butanes. When the bulk density is 0.43 g / mL or more, the pores of the carbonaceous material do not become too large, and it can possess many pores effective for the adsorption of butanes. When the bulk density is 0.65 g / mL or less, pores contributing to the adsorption of butanes tend to be sufficiently present. For the specific measurement and calculation method of the bulk density, reference may be made to the examples.

[0028] The bulk 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 range of the bulk density is within the above range, a carbonaceous material having a higher adsorption performance for butanes tends to be obtained.

[0029] The reactive black 5 of the carbonaceous material is 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 referred to as C.I. Reactive Black-5.

[0030]

Chemical formula

[0031] Since Reactive Black 5 has a large molecular weight of 995.88 and a bulky structure, the Reactive Black 5 valence serves as an indicator of the cumulative pore volume in the large pores of the carbonaceous material. When the Reactive Black 5 valence of the carbonaceous material is within the above range, it exhibits high adsorption performance for butanes. When the Reactive Black 5 valence is 3.0 g / L or more, among the pores of the carbonaceous material, the relatively large pores that are difficult to adsorb butanes decrease. Therefore, the pore volume effective for the adsorption of butanes increases, and as a result, the adsorption performance for butanes is significantly improved. Also, when the Reactive Black 5 valence is 60.0 g / L or less, the carbonaceous material can retain the pore volume effective for the adsorption of butanes. Therefore, the adsorption performance for butanes is significantly improved.

[0032] The Reactive Black 5 valence can be calculated, for example, as follows. That is, first, using an ultraviolet-visible spectrophotometer, under the conditions of a wavelength of 594 nm and an optical path length (cell length) of 10 mm, the absorbance of each of a test solution containing Reactive Black 5 and a residual solution obtained by removing the carbonaceous material adsorbed with Reactive Black 5 after mixing the carbonaceous material with the test solution and sufficiently adsorbing Reactive Black 5 onto the carbonaceous material is measured. Then, using these absorbances, the residual ratio (%) of Reactive Black 5 contained in the residual solution and the adsorption amount ( / g) of Reactive Black 5 per 1 g of the carbonaceous material are calculated. The Reactive Black 5 valence (g / L) is calculated as the amount of the carbonaceous material required to remove 99% of Reactive Black 5 in 1 L of the test solution using these values. In the measurement of the Reactive Black 5 valence, as the carbonaceous material, it is preferable to use a carbonaceous material whose 50% particle diameter (D50) of the volume-based cumulative distribution is adjusted to be 9.0 μm or more and 11.0 μm or less. In this specification, the 50% particle diameter (D50) refers to the value measured as the volume-based median diameter using a laser diffraction light scattering method particle size distribution measuring device. For the specific measurement and calculation method of the Reactive Black 5 valence, reference may be made to the examples.

[0033] Reactive Black 5 valence 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, still 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 range of Reactive Black 5 valence is within the above range, a carbonaceous material having higher adsorption performance for butanes tends to be obtained.

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

[0035] The iodine adsorption amount is an index of the surface area of pores in the carbonaceous material that can physically adsorb butanes. When the iodine adsorption amount of the carbonaceous material is within the above range, the carbonaceous material exhibits high adsorption performance for butanes. When the iodine adsorption amount is 710 mg / g or more, the pore volume of the carbonaceous material does not become too small, and a large number of pores effective for the adsorption of 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 a large number of pores effective for the adsorption of butanes can be retained.

[0036] The iodine adsorption amount is measured and calculated in accordance with JIS K 1474 (2014). For the specific measurement and calculation method of the iodine adsorption amount, refer to the examples.

[0037] In the carbonaceous material, the ratio of the pore volume with 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 still more preferably 73% or more and 89% or less. When the range of the ratio of the pore volume 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 with a pore diameter of 0.80 nm or less is the proportion of the small pores possessed by the carbonaceous material. When the proportion of the pore volume with a pore diameter of 0.80 nm or less is 61% or more, the carbonaceous material has many small pores effective for butanes and tends to exhibit high adsorption performance. When the proportion of the pore volume with a pore diameter of 0.80 nm or less is 92% or less, the pore diameter does not become too small, and the carbonaceous material has many pores effective for the adsorption of butanes, so it tends to exhibit high adsorption performance.

[0039] The proportion of the pore volume with a pore diameter of 0.80 nm or less is obtained as the ratio of the pore volume with a pore diameter of 0.80 nm or less to the pore volume with a pore diameter of 2.0 nm or less. For the specific measurement and calculation method of the proportion of the pore volume with a pore diameter of 0.80 nm or less, reference may be made to the examples.

[0040] The average pore diameter of the micropores of 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 range of the average pore diameter is within the above range, a carbonaceous material having higher adsorption performance for butanes tends to be obtained.

[0041] The average pore diameter of the micropores is the average value of the pore diameters of the micropores in the carbonaceous material. When the average pore diameter is within the above range, the carbonaceous material tends to more preferably hold pores effective for the adsorption of butanes.

[0042] The average pore diameter of the micropores is calculated by the QSDFT method per 1 g of the carbonaceous material from the nitrogen adsorption isotherm for the specific surface area (m 2 / g) (hereinafter also simply referred to as the "specific surface area of the micropores") of the micropores with a pore diameter of 2.0 nm or less, and the pore volume (cm 3(hereinafter also simply 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 diameter, reference may be made to the examples. In addition, when measuring and calculating the average pore diameter of micropores, pores with a pore diameter of 2.0 nm were also regarded as micropores. Average pore diameter of micropores (nm) = (pore volume of micropores (cm 3 / 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. Such shapes include, for example, powdery, massive, crushed, spherical, cylindrical, ellipsoidal, distorted, elliptical cylindrical, frustum of an elliptical cone, and polygonal columns such as triangular column, square column, pentagonal column, and hexagonal column, etc., rod-shaped, filamentous, pellet-shaped such as solid pellet and hollow pellet, crushed such as powdery, substrate-shaped (sheet-shaped), woven fabric (cloth) - shaped, fibrous such as felt-shaped, and block-shaped, etc.

[0044] The shape of the carbonaceous material is preferably a shape applicable as the carbonaceous material in known adsorption filters. Such shapes include, for example, spherical, ellipsoidal, distorted, rod-shaped, filamentous, pellet-shaped, crushed such as powdery, substrate-shaped (sheet-shaped), woven fabric (cloth) - shaped, fibrous, and block-shaped. These shapes can be appropriately selected according to the specific usage mode. Among these, since the adsorption performance per unit volume is high, the shape of the carbonaceous material is preferably crushed, and more preferably powdery. In the case of a powdery carbonaceous material, its dimensions are not particularly limited, and the particle size, etc. can be appropriately adjusted according to the specific usage mode.

[0045] In this specification, "crushed" refers to particles having an irregular shape and usually having any angular shape. Also, "powdery" refers to, for example, fine powder, powder, fine granular, and granular powders, and usually, the 50% particle size (D50) of the cumulative distribution based on volume is 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 is preferably powder, granule, pellet, or fiber. When the carbonaceous material has such a shape, it is easy to subject it to sheet processing and pleat filling processing, 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 of manufacturing carbonaceous materials] The carbonaceous material of the present embodiment can be obtained by a known production method.

[0049] Examples of such a method include a pyrolysis 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, it is possible to obtain a 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. 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 value of 3.0 g / L or more and 60.0 g / L or less, tend to be more easily produced.

[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 material, and an activation step of activating the carbonized material to obtain an activated material. The method for producing a carbonaceous material according to the present embodiment preferably includes a washing step of washing the activated material.

[0051] (carbonization process) The method for producing a carbonaceous material includes a carbonization step of carbonizing a raw material to obtain a carbonized material. The raw material is not particularly limited as long as it can obtain the desired carbonaceous material. Examples of the raw material include plant-based raw materials or fossil-based raw materials such as wood, wood powder, fruit shells such as coconut shells, palm kernels, seeds such as plums and peaches, by-products during pulp production, bagasse, molasses, coal (such as peat, lignite, brown coal, and bituminous coal), anthracite, petroleum distillation residue components, petroleum pitch, coke, and coal tar; 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 polybutylene, polybutadiene, and polychloroprene; other synthetic woods; synthetic pulp, etc. These raw materials can be used alone or, depending on the required specifications, two or more of them can be mixed and used in any ratio.

[0052] The raw material is preferably a natural product, more preferably a coconut shell. By using such a raw material, the pore volume (cm 3 / g) of pores 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 is 0.23 cm 3 / g or more and 0.35 cm 3 / g or less, the bulk density measured in accordance with JIS K1474 (2014) is 0.43 g / mL or more and 0.65 g / mL or less, and there is a tendency to more easily produce a carbonaceous material in which the reactive black 5 valence is 3.0 g / L or more and 60.0 g / L or less.

[0053] The raw material may contain additives, etc. as required. Also, additives, etc. may be added to the carbide as required.

[0054] Examples of such additives, etc. include water, coal tar, tar, hard pitch, coal tar-based pitch, and petroleum-based pitch. The additives, etc. may be used alone or in combination of two or more. Additives and the like are each usually blended in an amount of 1.0 part by mass or more and 50.0 parts by mass or less with respect to 100 parts by mass of the raw material or carbide. Further, the total amount of additives and the like is usually 1 part by mass or more and 100 parts by mass or less with respect to 100 parts by mass of the raw material or carbide. When mixing the raw material or carbide and the additive, if necessary, the oxygen amount in the raw material or carbide may be adjusted in advance in the range of 1.0% by mass or more and 20.0% by mass or less with respect to 100% by mass of the raw material or carbide. The adjustment of the oxygen amount can be carried out, for example, by mixing the raw material or carbide and oxygen under heating at 150°C or higher and 300°C or lower.

[0055] In the method for producing a carbonaceous material, the raw material may be pulverized or formed before carbonizing the raw material. Examples of such methods include a method in which the raw material is pulverized into a powder or granule using a known pulverizer and then carbonized before carbonizing the raw material. Further, examples include a method in which the raw material is formed into pellets by a known method and then carbonized before carbonizing the raw material.

[0056] When the shape of the raw material is powder, the particle size of the powder (50% particle diameter of the cumulative distribution based on volume, D50) is preferably 1 μm or more and 150 μm or less. When the shape of the raw material is granule, the particle size of the granule (D50) is preferably 150 μm or more and 2000 μm or less. When the shape of the raw material is pellet, the particle size of the pellet (D50) is preferably 2000 μm or more and 3000 μm or less.

[0057] The carbonization method of the raw material is not particularly limited, and examples thereof include a method of heating to 300°C or higher and 900°C or lower, preferably 400°C or higher and 800°C or lower, under an oxygen-free condition.

[0058] The carbonization time can be appropriately set according to the raw material and the equipment for carbonization. The carbonization time is, for example, 15 minutes or more and 20 hours or less, preferably 30 minutes or more and 10 hours or less. The carbonization treatment can be carried out using a known production equipment such as a fluidized furnace. Further, 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, a carbide may be pulverized into a powder or granular form using a known pulverizer. Further, the carbide may be formed into a pellet form using a known method. By these methods, the pore volume (cm 3 / g) of pores 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 is 0.23 cm 3 / g or more and 0.35 cm 3 / g or less, the bulk density measured in accordance with 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, there is a tendency to more easily produce a carbonaceous material. In the method for producing a carbonaceous material, after pulverizing the carbide into a powder or granular form or forming it into a pellet form, if necessary, an additive or the like may be added to the powdered carbide and kneaded by a known method, and the obtained kneaded material may be formed by a known method.

[0060] When the shape of the carbide is powder, granular, or pellet, the preferable range of the particle size (50% particle size of the cumulative distribution based on volume, D50) of each carbide is the same as the preferable range when the shape of the above raw material is powder, granular, or pellet.

[0061] In the method for producing a carbonaceous material, a carbide, a powdered or granular carbide, a kneaded material, or a powdered or granular kneaded material may be formed into a cylindrical pellet form using a known method. By this, the pore volume (cm 3 / g) of pores 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 is 0.23 cm 3 / g or more and 0.35 cm 3 / g or less, the bulk density measured in accordance with 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, there is a tendency to more easily produce a carbonaceous material. When the carbide is in the shape of a cylindrical pellet, the diameter of the cylindrical pellet is preferably 0.1 mm or more and 4.0 mm or less. Further, the aspect ratio (diameter: height) of the cylindrical pellet is preferably 1:1 to 1:10.

[0062] By the above carbonization step, a carbide of the raw material is obtained.

[0063] The method for producing the carbonaceous material may include a cleaning step and / or a drying step of performing a cleaning treatment and / or a drying treatment, etc. on the carbide after the carbonization step. The conditions in these steps are not particularly limited, and known conditions can be adopted. Also, the following cleaning step and drying step may be referred to.

[0064] (Activation step) The method for producing the carbonaceous material includes an activation step of subjecting the carbide to an activation treatment to obtain an activated product.

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

[0066] For the activation treatment, known production equipment such as a rotary kiln, a fluidized furnace, and a sleep furnace (vertical furnace) can be used. Also, the activation treatment may be performed under reduced pressure by excluding air, or may be performed in a nitrogen atmosphere.

[0067] The activation treatment is preferably performed using a fluidized furnace. Since a fluidized furnace can efficiently bring the carbide into contact with the active gas, mesopores do not develop, and a large number of micropores can be imparted to the carbonaceous material. In particular, micropores with a pore diameter of 0.80 nm or less can be efficiently imparted to the carbonaceous material in a short time.

[0068] When performing the activation treatment using a fluidized furnace, the carbide introduced into the fluidized furnace preferably has a particle size that passes through a 70-mesh (aperture size: 243 μm) standard sieve mesh defined in JIS Z8801-1:2019 and is retained on a 10-mesh sieve (aperture size: 1.54 mm), more preferably a particle size that passes through a 70-mesh (aperture size: 243 μm) standard sieve mesh and is retained on a 14-mesh sieve (aperture size: 1.31 mm). When the particle size of the carbide is within the above range, the activated product whose mass has become lighter as the activation of the carbide progresses stays in the fluidized furnace, making it possible to perform the activation more efficiently. As the carbide, carbide whose particle size is adjusted by cutting the raw material into a desired size in advance before the carbonization process may be used, or carbide whose particle size is adjusted by crushing and classifying the carbide into a desired size may be used.

[0069] Examples of the activation treatment method include methods using active gases such as water vapor gas, oxygen gas, and carbon dioxide gas. By using an active gas as the activation method, it tends to be easier to obtain a carbonaceous material having many micropores, particularly having more 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 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 control the reaction rate without further reducing the production efficiency. Also, by using water vapor gas, many micropores can be imparted to the carbonaceous material, and particularly, the proportion of pores with a pore diameter of 0.80 nm or less can be increased in the carbonaceous material. Therefore, it tends to be possible to suitably produce a carbonaceous material having a higher adsorption performance for butanes.

[0072] Generally, since the activation reaction is an endothermic reaction, in order to make the activation reaction proceed more efficiently, a certain amount of heat is required. To maintain that amount of heat, it is preferable to use oxygen gas together with water vapor gas as the active gas. By reacting and burning the volatile gas generated during the activation reaction with oxygen gas, it becomes possible to maintain the amount of heat required for activation. Examples of the volatile gas include combustible gases such as hydrogen gas and carbon monoxide gas generated by activating carbides.

[0073] When an excessive amount of oxygen gas is introduced into the fluidized bed as the active gas, excess oxygen gas that does not react with the volatile gas is generated. That excess oxygen gas may undergo a combustion reaction with the carbide and destroy the pores of the carbonaceous material. Therefore, it is preferable to perform the activation treatment while controlling the amount of oxygen gas within a suitable range.

[0074] When using water vapor gas and oxygen gas as the active gas, their ratio is preferably 5 vol% or more and 15 vol% or less of water vapor gas with respect to 1 vol% of oxygen gas, and more preferably 8 vol% or more and 12 vol% or less of water vapor gas. When their ratio is within the above range, the pore volume (cm 3 / g) of pores 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 is 0.23 cm 3 / g or more and 0.35 cm 3 / g or less, the bulk density measured in accordance with JIS K1474 (2014) is 0.43 g / mL or more and 0.65 g / mL or less, and the carbonaceous material with a reactive black 5 value of 3.0 g / L or more and 60.0 g / L or less can be more easily manufactured.

[0075] When using water vapor gas, oxygen gas, and carbon dioxide gas as the active gases, the partial pressure of 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 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 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. In addition, as other gases, an inert gas such as nitrogen may be included. In that 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 their ratios are within the above ranges, the pore volume (cm 3 / g) 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 is 0.23 cm 3 / g or more and 0.35 cm 3 / g or less, the bulk density measured in accordance with JIS K1474 (2014) is 0.43 g / mL or more and 0.65 g / mL or less, and there is a tendency to more easily produce a carbonaceous material in which the reactive black 5 value is 3.0 g / L or more and 60.0 g / L or less.

[0076] When using water vapor gas and oxygen gas as the active gases, their flow rates are 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 according to conditions such as the raw material, activation temperature, and manufacturing equipment. As the activation time, for example, it 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, still more preferably 45 minutes or more and 480 minutes or less, and even more preferably 50 minutes or more and 360 minutes or less. When the activation time is within the above range, the pore volume (cm 3 / g) 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 is 0.23 cm 3 / g or more and 0.35 cm3 is 0.43 g / mL or more and 0.65 g / mL or less as measured in accordance with JIS K1474 (2014), and the quinone form of reactive black is 3.0 g / L or more and 60.0 g / L or less, there is a tendency to more easily produce a carbonaceous material.

[0078] The activation treatment temperature 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 still more preferably 870°C or higher and 950°C or lower. When the activation temperature is within the above range, the pore volume (cm 3 / g) of pores 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 is 0.23 cm 3 / g or more and 0.35 cm 3 / g or less, and the bulk density measured in accordance with JIS K1474 (2014) is 0.43 g / mL or more and 0.65 g / mL or less, and the quinone form of reactive black is 3.0 g / L or more and 60.0 g / L or less, there is a tendency to more easily produce a carbonaceous material.

[0079] Examples of the activation device for performing the activation treatment include a fluidized furnace as shown in the schematic cross-sectional view of FIG. 1.

[0080] As shown in FIG. 1, the fluidized furnace usually includes gas inlets 1 to 4 in the lowermost layer, a fluidized bed 5 arranged in the upper layer thereof, a combustion layer 6 of combustible gas arranged in the upper layer thereof, and a gas outlet 8 arranged in the upper layer thereof. The gas introduced from the gas inlets 1 to 4 is sent in the main direction A of the gas, ventilates through the fluidized bed 5 and the combustion layer 6 of combustible gas, and is discharged from the gas outlet 8. The carbide as the raw material is charged into the fluidized bed 5, and a carbonaceous material is produced by being activated in the fluidized bed 5.

[0081] The gas inlets 1 to 4 are inlets for introducing each of the steam gas, oxygen gas, carbon dioxide gas, and nitrogen gas into the fluidized furnace. It is preferable that the gas inlets 1 to 4 are, respectively, the inlet for the steam gas, the inlet for the carbon dioxide gas, the inlet for the nitrogen gas, and the inlet for the oxygen gas. When the gas inlets 1 to 4 are arranged in such a manner and each gas is introduced into the fluidized furnace, the activation treatment of the carbide (raw material) tends to proceed more suitably, and a desired carbonaceous material can be more easily manufactured. In FIG. 1, four gas inlets are arranged, but the number of gas inlets can be appropriately set according to, for example, the type of raw material, the degree of activation, and the size of the equipment. Also, the types of gases introduced into the gas inlets 1 to 4 can be appropriately set according to, for example, the type of raw material, the degree of activation, and the size of the equipment.

[0082] As shown in FIG. 1, it is preferable that the fluidized furnace includes an oxygen-containing gas inlet 7 for introducing an oxygen-containing gas. By introducing the oxygen-containing gas into the fluidized furnace from the oxygen-containing gas inlet 7, the volatile gas can be efficiently burned. Thereby, combustion heat is generated, and the temperature in the fluidized bed 5 can be further increased by the combustion heat, and the activation can proceed more efficiently. Also, since the volatile gas burns efficiently with the oxygen-containing gas, the oxygen gas introduced from the gas inlets 1 to 4 is less likely to be excessive. As a result, the oxygen gas can more suitably suppress the combustion reaction with the carbide, so that the pores of the carbonaceous material can be more easily controlled. For such reasons, there is a tendency to more easily manufacture a carbonaceous material having desired pores and specific surface area.

[0083] The position of the oxygen-containing gas inlet 7 should be at a position in the fluidized furnace that does not contact the upper end of the fluidized bed 5, and preferably at a position where the oxygen-containing gas can be introduced into the combustion layer 6 of the combustible gas. Also, the direction of the oxygen-containing gas inlet 7 is preferably parallel to the main direction A of the gas and opposite to the main direction A of the gas (i.e., the downstream layer side). By arranging the oxygen-containing gas inlet 7 in this way, the oxygen-containing gas can be suitably blown into the combustion layer 6 of the combustible gas, so that the temperature in the fluidized furnace can be further increased. Thereby, since the carbide can be activated more uniformly, there is a tendency that a carbonaceous material having a desired pore size distribution can be manufactured more easily.

[0084] The material of the fluidized furnace is not particularly limited as long as it is a material used for the fluidized furnace. For example, stainless steel can be mentioned.

[0085] Thus, by using a fluidized furnace as the activation device, the pore volume (cm 3 / g) of pores 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 is 0.23 cm 3 / g or more and 0.35 cm 3 / g or less, the bulk density measured in accordance with JIS K1474 (2014) is 0.43 g / mL or more and 0.65 g / mL or less, and the reactive black 5 valence is 3.0 g / L or more and 60.0 g / L or less. There is a tendency that a carbonaceous material can be manufactured more easily.

[0086] By the above activation step, an activated product is obtained.

[0087] The method for producing the carbonaceous material may have a washing step and / or a drying step, etc., in which after the activation step, the activated product is subjected to a washing treatment and / or a drying treatment, etc. The conditions in these steps are not particularly limited, and known conditions can be adopted. Also, the following washing step and drying step may be referred to.

[0088] (Washing step) The carbonaceous material is preferably obtained through a washing step of washing the activated product obtained in the activation step. More preferably, the washing is water washing. By undergoing such a washing step, the pore volume (cm 3 / g) of pores with a pore diameter of 0.80 nm or less calculated by the QSDFT method per gram of the carbonaceous material from the nitrogen adsorption isotherm is 0.23 cm 3 / g or more and 0.35 cm 3 / g or less, the bulk density measured in accordance with 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, and there is a tendency to more easily manufacture a carbonaceous material.

[0089] The temperature and time in the washing may be appropriately adjusted so that the target carbonaceous material can be obtained.

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

[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 the pressure is preferable. As the method of drying by heating, a hot air drying method is preferable from the viewpoint of no drying unevenness and stable drying. In the drying step, it is preferable to dry until the moisture content of the carbonaceous material becomes 20.0 mass% or less, and more preferably until it becomes 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; a mixed dryer such as a conical dryer and a Nauta dryer. The heating temperature may be a temperature at which the carbonaceous material hardens and does not melt, and for example, 40°C or more and 300°C or less is preferable.

[0093] Examples of the pressure reduction method include a pressure reduction method using an oil pump, an oil-free 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 depends on the drying temperature, but is usually about 1 minute or more and 20 hours or less.

[0095] The carbonaceous material thus obtained may be used as it is, or, if necessary, by a known method, adjustment of the particle size by crushing, pulverizing, and classification; for example, purification by additional washing using water, an organic solvent, an acid aqueous solution, and an alkali aqueous solution; imparting durability and structural adjustment using additional heat treatment to obtain a carbonaceous material.

[0096] [Use] The carbonaceous material can be suitably used for various applications for removing, adsorbing, concentrating, and recovering butanes. Such applications may be applications in which the operations of removal, adsorption, concentration, and recovery are appropriately combined. Examples of such applications include an adsorption filter and a packed column.

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

[0098] [Method for Adsorbing Butanes] The method for adsorbing butanes includes an adsorption step of adsorbing butanes to the carbonaceous material. Examples of the method for adsorbing butanes include a method of adsorbing butanes to the carbonaceous material to concentrate the butanes in the carbonaceous material. The concentration method may have the same steps as known methods for adsorbing, concentrating, and recovering butanes, etc., other than using the carbonaceous material of the present embodiment as the carbonaceous material.

[0099] In the adsorption step, for example, by bringing butanes into contact with a carbonaceous material, the butanes are 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 the present embodiment is used as the carbonaceous material.

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

[0102] The apparatus includes, for example, an adsorption section for bringing butanes into contact with the carbonaceous material. In the adsorption section, an adsorbent other than the carbonaceous material according to the present embodiment may be included as necessary. Examples of such an adsorbent include activated carbon, zeolite, silica gel, activated alumina, non-woven fabric, and porous organic compounds other than the carbonaceous material according to the present embodiment.

[0103] The processing apparatus may include another adsorption filter together with an adsorption filter or the like containing a carbonaceous material. Examples of such another adsorption filter include metal filters made of stainless steel, aluminum, bronze, copper, titanium, nickel, etc.; resin filters made of polypropylene, polyvinyl chloride, polyvinylidene chloride, polyethylene, polyamide, fluororesin, etc.

[0104] Further, the processing apparatus may be batch type or continuous type, and the carbonaceous material can be used in either mode.

[0105] 〔Adsorption Filter〕 The adsorption filter of this embodiment contains the carbonaceous material of this embodiment. Further, the adsorption filter is preferably for automobiles.

[0106] Since the adsorption filter contains a carbonaceous material, it 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 vehicle interior space.

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

[0108] Examples of the fibrous binder include those that can entangle and shape the carbonaceous material by fibrillation. Such fibrous binders may be synthetic or natural. Examples of the fibrous binder include acrylic fiber, polyethylene fiber, polypropylene fiber, polyacrylonitrile fiber, cellulose fiber, nylon fiber, aramid fiber, and pulp.

[0109] The fibrous binder may be used alone or in an appropriate combination of two or more. The fibrous binder is preferably polyacrylonitrile fiber and / or pulp. By using these fibrous binders, the density and strength of the adsorption filter can be further increased, and performance degradation can be suppressed.

[0110] Since there is a tendency to obtain a carbonaceous material having higher adsorption performance for butanes, the adsorption filter preferably contains the fibrous binder in an amount of 20 parts by mass or less, more preferably 10 parts by mass or less, based on 100 parts by mass of the carbonaceous material. The lower limit is usually 0.01 part by mass or more. In addition, when the adsorption filter contains other functional components described later, "with respect to 100 parts by mass of the carbonaceous material" regarding the filter composition may be read as "with respect to a total of 100 parts by mass of the carbonaceous material and other functional components" and applied accordingly.

[0111] The adsorption filter may contain other functional components as long as the effects of the present embodiment are not inhibited. Examples of such other functional components include lead adsorbents such as titanosilicate and zeolite-based powder that can adsorb and remove soluble lead; ion exchange resins; chelate resins; and various adsorbents containing silver ions and / or silver compounds for imparting antibacterial properties.

[0112] [Automobile Adsorption Filter] The automobile adsorption filter of the present embodiment contains the carbonaceous material of the present embodiment. The automobile adsorption filter may have the same configuration as a known automobile adsorption filter in addition to containing the carbonaceous material of the present embodiment. By containing the carbonaceous material, the automobile 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 vehicle interior space.

Examples

[0113] Hereinafter, examples and comparative examples will be shown to more specifically explain the present invention, but the present invention is not limited by these examples in any way.

[0114] [Evaluation Method]

[0115] (1) Pore volume of pores 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 size distribution measuring device (BELSORP (registered trademark)-MAX (product name) manufactured by Microtrac BEL Co., Ltd.), after heating the carbonaceous material under vacuum conditions at 300 °C for 3 hours, the nitrogen gas adsorption isotherm under the condition of a temperature of 77 K was measured.

[0116] ·Measurement of Pore Volume The pore volume (cm 3 ) of pores with a pore diameter of 0.80 nm or less among the micropores calculated by the QSDFT method per 1 g of the carbonaceous material from the nitrogen adsorption isotherm was calculated as follows. Specifically, using the values of the nitrogen gas adsorption isotherm obtained by the above-mentioned "Measurement of Nitrogen Gas Adsorption Isotherm Using BELSORP-MAX", and applying N 2 at 77K carbon[slit pore / cyl.pore (QSDFT Ads.model)] as the calculation model to calculate the pore size distribution, the pore volume (cm 3 / g) of pores with a pore diameter of 0.80 nm or less was calculated.

[0117] (2) Bulk Density The bulk density (g / mL) of the carbonaceous material was measured in accordance with JIS K1474 (2014). Specifically, first, the carbonaceous material was dried in a constant temperature dryer (Yamato Scientific Co., Ltd. DVS402 (product name)) at 115 ± 5°C for 3 hours. Then, it was allowed to cool to room temperature in a desiccator using silica gel as a desiccant to obtain the carbonaceous material after cooling. The carbonaceous material after cooling was introduced into the storage funnel of a bulk density measurement container (manufactured by Toyo Denki Kikai Seisakusho Co., Ltd., model number TD-V5 (product name)), and the carbonaceous material was filled up to the 100 mL mark of the bulk density measurement container using the attached vibrator. The mass of the carbonaceous material after filling was measured to the nearest 0.1 g.

[0118] (3) Reactive Black 5 Valence Using the carbonaceous material, the reactive black 5 valence (g / L) was measured. Specifically, first, the carbonaceous material was pulverized so that the 50% particle size (D50) of the volume-based cumulative distribution was about 10.0 μm or less, and dried in a constant temperature dryer (Yamato Scientific Co., Ltd. DVS402 (product name)) at 115°C for 3 hours. Then, it was allowed to cool to room temperature in a desiccator using silica gel as a desiccant to obtain the carbonaceous material after cooling.

[0119] On one hand, a test solution A containing a phosphate buffer and reactive black 5 (manufactured by Sigma-Aldrich) was prepared as follows. That is, 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 a phosphate buffer (pH: 7.0). Then, for 1 L of the obtained phosphate buffer, reactive black 5 was added in the range of about 0.5 g or more and 1.2 g or less to prepare test solution A. At that time, the amount of reactive black 5 was adjusted as follows. That is, the amount of reactive black 5 added to 1 L of the phosphate buffer was appropriately adjusted so that the absorbance of the solution obtained by diluting the obtained test solution A 20-fold with distilled water was in the range of 1.18 or more and 1.23 or less. The absorbance was the absorbance at a wavelength of 594 nm and was measured with an ultraviolet-visible spectrophotometer (double-beam spectrophotometer U-2910 (trade name) manufactured by Hitachi High-Tech Corporation) using a glass cell with an optical path length of 10 mm. In addition, the solution obtained by diluting the test solution A obtained as described above 20-fold was used as test solution B, and that test solution B was used for the measurement of the following absorbance.

[0120] Next, an arbitrary mass (the amount at which the residual rate of reactive black 5 contained in the filtrate is about 10% according to the following formula (II)) of the above-mentioned carbonaceous material after cooling was taken in a 100 mL conical flask with a stopper, and the carbonaceous material was added to 50 mL of the test solution A prepared above. Using a shaking thermostatic bath (water bath shaker MM-10 (trade name) manufactured by Taitec Corporation), it was shaken in a water bath at 40 °C at a speed of 150 times / min for 5 hours to obtain a mixed solution. Then, 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] Using a glass cell with an optical path length of 10 mm, the absorbances of the obtained test solution B and the filtrate were measured at a wavelength of 594 nm using an ultraviolet-visible spectrophotometer (double-beam spectrophotometer U-2910 (trade name) manufactured by Hitachi High-Tech Corporation). Using these absorbances, the adsorption amount of reactive black 5 per 1 g of the carbonaceous material (hereinafter simply referred to as "RB5 adsorption amount per 1 g of carbonaceous material ( / g)") was calculated according to the following formula (I). RB5 adsorption amount per 1 g of carbonaceous material ( / g) = (absorbance of test solution B at a wavelength of 594 nm × 20 - absorbance of filtrate at a wavelength of 594 nm) / mass of carbonaceous material (g) ··· (I)

[0122] Also, the residual rate of reactive black 5 contained in the filtrate (hereinafter simply referred to as "RB5 residual rate (%)") was calculated according to 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 per 1 g of the carbonaceous material ( / g) on the vertical axis. Using the power approximation formula, the adsorption amount of reactive black 5 when the RB5 residual rate is 1% (hereinafter simply referred to as "RB5 adsorption amount when RB5 residual rate is 1% ( / g)") was obtained, and the reactive black 5 valence (g / L) was calculated according to 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 when RB5 residual rate is 1% ( / g)) / 0.05 (L) ··· (III) Note that 0.05 (L) in formula (III) is the amount 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 measurement of the iodine adsorption amount was carried out in accordance with JIS K1474 (2014). That is, first, in accordance with JIS Z8801-1, the carbonaceous material was pulverized until it passed through a 45-μm sieve by 90% or more, and then dried in a constant-temperature dryer at 115°C (DVS402 (trade name) manufactured by Yamato Scientific Co., Ltd.) for 3 hours. Thereafter, it was allowed to cool to room temperature in a desiccator using silica gel as a desiccant, and the carbonaceous material after cooling was obtained.

[0125] 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 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 Corporation), and an appropriate amount of distilled water was added to the iodine solution to prepare a 0.05 mol / L iodine solution.

[0126] Next, an arbitrary amount of the carbonaceous material after the above cooling (an amount such that the iodine residual concentration in the supernatant of the following filtrate is approximately 2.5 g / L) was weighed and placed in a 100-mL conical flask with a stopper. Further, 50 mL of the above 0.05 mol / L iodine solution was added in its entirety with a pipette. At room temperature (20°C or higher and 30°C or lower), using a shaker (medium-sized shaker reciprocating shaker NR-10 (trade name) manufactured by Taitec Co., Ltd.), it was shaken at 200 times / min for 15 minutes to adsorb iodine to the carbonaceous material and obtain 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 in its entirety with a pipette and titrated with a 0.1 mol / L sodium thiosulfate solution (manufactured by Fujifilm Wako Pure Chemical Corporation, factor: 1.000), and the iodine residual concentration was calculated by the following formula (IV). Iodine residual concentration (g / L) = amount of 0.1 mol / L sodium thiosulfate solution used for titration (mL) × factor of 0.1 mol / L sodium thiosulfate solution × 12.69 / 10 ··· (IV)

[0127] The amount of iodine adsorption per 1 g of the carbonaceous material was calculated by the following formula (V). Amount of iodine adsorbed per 1 g of carbonaceous material = (10 × factor of 0.05 mol / L iodine solution – amount of 0.1 mol / L sodium thiosulfate solution used in titration (mL) × factor of 0.1 mol / L sodium thiosulfate solution) × 12.69 × 5 / mass of carbonaceous material (g) (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 of 0.1 mol / L sodium thiosulfate solution used in titration (mL) × factor of 0.1 mol / L sodium thiosulfate solution) / 10 (VI)

[0129] Using Freundlich's adsorption isotherm, an adsorption isotherm was created 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 size 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) Volume of pores with a pore diameter of 0.80 nm or less", the specific surface area (m2) of micropores with a pore diameter 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 by the above-mentioned "Measurement of nitrogen gas adsorption isotherm using BELSORP-MAX" was used as the calculation model. 2 The pore size distribution was calculated using the QSDFT Ads.model at 77K carbon[slit pore / cyl.pore (QSDFT Ads.model)] to obtain 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) Volume of pores 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 per 1 g of carbonaceous material calculated by the QSDFT method was calculated. 3 / g) was calculated as follows. Specifically, the nitrogen gas adsorption isotherm value obtained by the above-mentioned "Measurement of nitrogen gas adsorption isotherm using BELSORP-MAX" was used as the calculation model. 2 The pore size distribution was calculated using the QSDFT Ads.model at 77K carbon[slit pore / cyl.pore (QSDFT Ads.model)] to obtain the pore volume (cm) of pores with a diameter of 2.0 nm or less. 3 / g) was calculated.

[0132] How to calculate the average pore size of micropores The average pore size (nm) of the micropores in the carbonaceous material was calculated from the following formula (VII) using the specific surface area of ​​the micropores and the pore volume of the micropores obtained above. Average pore diameter of micropores (nm) = (pore volume of micropores (cm 3 / g) / specific surface area of ​​micropores (m 2 / g)) × 2000 (VII)

[0133] (6) Percentage of pore volume with a pore diameter of 0.80 nm or less The percentage (%) of the volume of pores with diameters of 0.80 nm or less in the carbonaceous material was calculated. Specifically, the percentage (%) of the pore volume of a carbonaceous material having a pore diameter of 0.80 nm or less is calculated by dividing the pore volume (cm) of the pores having a pore diameter of 0.80 nm or less obtained in the above section "(1) Volume of pores having a pore diameter of 0.80 nm or less" by the 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 of pores with diameters of 2.0 nm or less (cm3 / g) × 100 (VIII)

[0134] (8) n-Butane adsorption capacity (n-butane adsorption performance) The n-butane adsorption amount (mg / g) of the carbonaceous material was measured and calculated. Specifically, first, the carbonaceous material was sieved into a particle size range of 0.600 mm or more and 0.250 mm or less nominal opening size using a test sieve in accordance with JIS Z8801-1 to make the particle size uniform. 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, it was allowed to cool to room temperature in a desiccator using silica gel as a desiccant, and a carbonaceous material after cooling was obtained.

[0135] Next, 0.492 g of the cooled carbonaceous material was packed into a glass column (manufactured by Iwata Glass Co., Ltd.) with an inner diameter of 28 mm. The packed glass column was then 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 placed in a gas chromatograph (Shimadzu Corporation GC-2014 (product name)) and n-butane gas (concentration: 80 ppm) adjusted to a relative humidity of 50% RT was passed through the column at a flow rate of 7.3 L / min as the test gas. The n-butane gas concentrations before and after passing through the column were measured, while the n-butane concentration before passing through the column (C 0 The breakthrough rate of the n-butane concentration (C) after passing through the column was calculated relative to the total concentration (C) of the column, and the test was continued until the value reached 95%. The breakthrough rate was calculated using the following formula (IX). Breakthrough rate (%) = n-butane concentration after passing through the column (C) / n-butane concentration before passing through the column (C 0 ) × 100...(IX)

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

[0138] Example 1 (carbonization process) Coconut shells from the Philippines were carbonized and crushed at a temperature of 600°C for approximately 2 hours, and then the particle size (50% particle size of the cumulative volume distribution, D50) was adjusted to 405 μm using a standard sieve mesh specified in JIS Z8801-1:2019, using a 70 mesh (mesh size: 243 μm, manufactured by Nishimura Wire Mesh Mfg. Co., Ltd.) over sieve and a 14 mesh under sieve (mesh size: 1.31 mm, manufactured by Nishimura Wire Mesh Mfg. Co., Ltd.) to obtain granular charcoal.

[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 steam, 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] (Cleaning process, drying process, etc.) The obtained activated material was thoroughly washed with water and dried to obtain a dried material, which was then pulverized to obtain a pulverized carbonaceous material 1, which is activated carbon.

[0141] Example 2 A pulverized carbonaceous material 2, which is 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 is 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 is 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 is 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 is 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 is 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 is 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 is 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 process) Coconut shells from the Philippines were carbonized and crushed at a temperature of 600°C for approximately 2 hours, and then sieved through a standard sieve mesh specified in JIS Z8801-1:2019 using a 70 mesh (mesh size: 243 μm, manufactured by Nishimura Wire Mesh Mfg. Co., Ltd.) over sieve and a 14 mesh under sieve (mesh size: 1.31 mm, manufactured by Nishimura Wire Mesh Mfg. Co., Ltd.) to obtain a granular carbonized material by adjusting the particle size (50% particle size of cumulative distribution on a volume basis, D50) to 405 μm.

[0150] (Activation treatment) The obtained carbide was introduced into a rotary kiln equipped with stirring blades in a furnace heated to 900 °C at about 0.06 times the volume of the rotary kiln of 1 m 3 . Then, while rotating the kiln at a rotational speed of 3.0 rpm, an active gas (35% by volume of steam, 5% by volume of oxygen, 5% by volume of carbon dioxide, and 55% by volume of nitrogen) was introduced into the kiln and immediately taken out to obtain an activated product.

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

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

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

[0154] [Comparative Example 4] (Carbonization step) The carbonization of wood powder produced in Japan and Malaysia was carried out at a temperature of 600 °C for about 2 hours. After pulverization, using a wire mesh for standard sieves specified in JIS Z8801-1:2019, with a sieve size of 20 mesh (opening size: 870 μm, manufactured by Nishimura Wire Mesh Manufacturing Co., Ltd.) on the sieve and 10 mesh below the sieve (opening size: 1.54 mm, manufactured by Nishimura Wire Mesh Manufacturing Co., Ltd.), the granular carbide was obtained by adjusting the particle size (50% particle diameter of the cumulative distribution based on volume, D50) to 1451 μm.

[0155] (Activation treatment) The obtained carbide was introduced into a rotary kiln equipped with stirring blades in a furnace heated to 850 °C at a volume of 1 m of the rotary kiln 3It was charged at about 0.06 times. Then, while rotating the kiln at a rotation speed of 3.0 rpm, an active gas (50% by volume of water vapor, 10% by volume of oxygen, 35.0% by volume of carbon dioxide, and 5.0% by volume of nitrogen) was introduced into the kiln until the specific surface area reached 1080 m 2 / g, and an activated product was obtained by performing an activation treatment.

[0156] (washing process, drying process, etc.) The obtained activated product was washed with dilute hydrochloric acid, then thoroughly washed with water to remove the remaining hydrochloric acid, and dried to obtain a dried product. Then, the obtained dried product was pulverized to obtain a pulverized carbonaceous material 13 which is activated carbon.

[0157] [Comparative Example 5] In the activation step of Example 1, 110 minutes was changed to 225 minutes, and the granular carbide obtained in Example 1 was activated. After pulverizing the obtained activated product, using a wire mesh for standard sieves specified in JIS Z8801-1:2019, with a 60-mesh (opening size: 243 μm, manufactured by Nishimura Wire Mesh Manufacturing Co., Ltd.) sieve on top and a 30-mesh sieve below (opening size: 550 μm, manufactured by Nishimura Wire Mesh Manufacturing Co., Ltd.), the particle size (50% particle diameter of the cumulative distribution based on volume, D50) was adjusted to 334 μm to obtain a granular activated product. Then, the obtained activated product was immersed in 0.5 N hydrochloric acid preheated to 95°C and allowed to stand at 95°C for 20 minutes while heating. Next, the activated product after immersion was washed with water until the pH reached about 6 - 7, and then dried until the water content of the activated product was 3% by mass or less to obtain activated carbon after drying. The specific surface area of the activated carbon after drying was 1,050 m 2 / g. Subsequently, an aqueous solution of sulfanilic acid with a concentration of 18% by mass (sulfanilic acid: reagent special grade manufactured by Fuji Film 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, and the sulfanilic acid was adhered to the activated carbon to obtain the adhered product 1. The obtained adhered product 1 was left at room temperature for 30 minutes as it was, and then an aqueous solution of citric acid with a concentration of 46% by mass was sprayed, and the citric acid was adhered to the activated carbon to obtain the adhered product 2. The obtained adhered product 2 was left at room temperature for 60 minutes as it was to obtain the adhered carbon. Subsequently, the adhered carbon was dried in a constant-temperature dryer (Yamato Scientific Co., Ltd. DVS402 (trade name)) at 90°C for 24 hours to obtain a carbonaceous material 14 (containing 8.0 parts by mass of sulfanilic acid and 4.4 parts by mass of citric acid with respect to 100 parts of activated carbon).

[0158]

Table 1

Industrial Applicability

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

Explanation of Symbols

[0160] A… Main direction of the gas, 1, 2, 3, 4… Gas inlets, 5… Fluidized bed, 6… Combustion layer of combustible gas, 7… Oxygen-containing gas inlet, 8… Gas outlet.

Claims

1. The pore volume (cm ３ / g) of pores 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 is 0.23 cm ３ / g or more and 0.35 cm ３ / g or less, the bulk density measured in accordance with JIS K1474 (2014) is 0.43 g / mL or more and 0.65 g / mL or less, and the reactive black pentavalent is 3.0 g / L or more and 60.0 g / L or less. Carbonaceous material.

2. The carbonaceous material according to Claim 1, wherein the iodine adsorption amount is 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 of pores 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 diameter 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 adsorption of at least one selected from the group consisting of n-butane, isobutane, 1,2-butadiene, and 1,3-butadiene.

6. A carbonization step of carbonizing a raw material to obtain a carbide, An activation step of subjecting the carbide to an activation treatment to obtain an activated product, and A method for producing a carbonaceous material according to any one of Claims 1 to 4.

7. The production method according to Claim 6, further comprising a washing step of washing the activated product.

8. The production method according to Claim 6, wherein the raw material is a coconut shell.

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

10. The adsorption filter according to Claim 9, wherein the adsorption filter is for an automobile.

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