Carbonaceous material, method for producing same, and method for adsorbing palladium complex

Abstract

A carbonaceous material according to the present invention has a ratio of mesopores of 6.4% to 50.0% inclusive, a reactive black 5 value of 1.0 g / L to 8.0 g / L inclusive, and an iodine adsorption amount of 1,000 mg / g to 1,600 mg / g inclusive.

Description

Carbonaceous material, its manufacturing method, and method for adsorbing palladium complex

[0001] The present invention relates to a carbonaceous material, a method for producing the same, and a method for adsorbing a palladium complex.

[0002] In organic synthetic chemistry, homogeneous catalysts containing palladium are widely used to promote reactions such as carbon-carbon bond formation and asymmetric hydrogenation. These palladium catalysts can efficiently promote reactions by dissolving them in solution. After the reaction is complete, the palladium catalyst can be removed by crystallization or distillation, but if the product is to be used in electronic materials, pharmaceuticals, etc., it is necessary to remove the palladium catalyst from the product and sufficiently reduce its content.

[0003] As a method for removing a palladium catalyst, for example, Patent Document 1 describes a method for removing a solution after an organic reaction by using a catalyst having a specific surface area of ​​50 m 2 / g or more 400m 2 A method of treating with activated alumina having a SiO2 content of 0.1g or less has been proposed.

[0004] Patent Document 2 describes a method for reducing residual palladium in a drug substance, in which a tri-substituted phosphine is added to a mixed solution of the drug substance, a solubilizing agent, and water, and a poor solvent is further added to crystallize the drug substance.

[0005] In Patent Document 3, an adsorbent is disclosed which is used to remove metal components such as palladium catalysts dissolved in organic solvents, and has a specific surface area of ​​1,300 m 2 / g or more and an average pore diameter of 1.8 nm or more is described.

[0006] JP 2008-260704 A JP 2011-57602 A JP 2017-177047 A

[0007] However, in the removal method described in Patent Document 1, the solution used to remove the palladium catalyst is an organic reaction solution using a catalyst containing a phosphorus-based ligand and a palladium compound, and therefore is not sufficiently effective against catalysts that do not contain a phosphorus-based ligand, such as palladium acetate.

[0008] In the reduction method described in Patent Document 2, a tri-substituted phosphine that forms a complex with residual palladium is added to the solution to remove the complex between the tri-substituted phosphine and the residual palladium. However, the method described in Patent Document 2 makes it difficult to remove palladium that is difficult to undergo ligand exchange with the tri-substituted phosphine, such as a palladium complex having a multidentate ligand. Furthermore, there is a concern that the residual tri-substituted phosphine may contaminate the target product.

[0009] Patent Document 3 describes a method for adsorbing a palladium catalyst using activated carbon, and describes that high removal performance is achieved for palladium acetate, a divalent palladium complex, by adjusting the pore characteristics and surface functional group amount of the adsorbent to a specific range. However, Patent Document 3 does not disclose effectiveness for zero-valent palladium complexes, and it is difficult to say that the activated carbon described in Patent Document 3 can be applied to the removal of various palladium complexes such as palladium catalysts.

[0010] The present invention has been made in view of the above problems, and aims to provide a carbonaceous material having high adsorption performance for various palladium complexes, a method for producing the same, and a method for adsorbing palladium complexes.

[0011] As a result of extensive research to solve the above problems, the present inventors have found that a carbonaceous material having a mesopore ratio, a pentavalent reactive black, and an iodine adsorption amount each falling within a specific range has high adsorption performance for various palladium complexes, and have completed the present invention.

[0012] The present invention includes the following embodiments: [1] A carbonaceous material having a mesopore ratio of 6.4% or more and 50.0% or less, a pentavalent reactive black of 1.0 g / L or more and 8.0 g / L or less, and an iodine adsorption of 1,000 mg / g or more and 1,600 mg / g or less.

[0013] [2] The mesopore volume determined by the BJH method from the N adsorption isotherm at -196 °C is 0.16 cm 3 / g or more 0.60cm 3 / g or less.

[0014] [3] The specific surface area determined by the BET method from the N adsorption isotherm at -196 °C is 950 m 2 / g or more 1,700m 2 / g or less.

[0015] [4] The specific surface area calculated by the BJH method from the N2 adsorption isotherm at -196°C is 23 m 2 / g or more 500m 2 / g or less.

[0016] [5] The carbonaceous material according to [1], having a pH of 4.5 or more and 9.5 or less.

[0017] [6] The carbonaceous material according to [1], having a packing density measured by a tapping method of 0.20 g / mL or more and 0.55 g / mL or less.

[0018] [7] The carbonaceous material according to any one of [1] to [6], which is used for adsorbing a zero-valent palladium complex and / or a divalent palladium complex in an organic solvent.

[0019] [8] A method for producing a carbonaceous material according to any one of [1] to [6], comprising: a carbonization step of carbonizing a raw material to obtain a carbonized material; and an activation step of activating the carbonized material to obtain an activated material.

[0020] [9] The method according to [8], further comprising a washing step of washing the activated material.

[0021]

[10] The manufacturing method described in [8], wherein the raw material is at least one selected from the group consisting of coconut shells and wood flour.

[0022]

[11] A method for adsorbing a palladium complex, comprising an adsorption step of adsorbing a palladium complex onto the carbonaceous material according to any one of [1] to [6].

[0023] According to the present invention, it is possible to provide a carbonaceous material having high adsorption performance for various palladium complexes, a method for producing the same, and a method for adsorbing palladium complexes.

[0024] In Fig. 1, I is a schematic cross-sectional view of a rotary kiln, and II is a schematic side view of the rotary kiln. Fig. 2 is a schematic cross-sectional view for explaining the rotary kiln.

[0025] Hereinafter, an embodiment for carrying out the present invention (hereinafter simply referred to as "the present embodiment") will be described in detail. Note that the present embodiment is an example for explaining the present invention, and the present invention is not limited to only this embodiment.

[0026] [Carbonaceous Material] The carbonaceous material of the present embodiment has a mesopore ratio of 6.4% or more and 50.0% or less, a pentavalent reactive black of 1.0 g / L or more and 8.0 g / L or less, and an iodine adsorption capacity of 1,000 mg / g or more and 1,600 mg / g or less.

[0027] By satisfying these requirements, the carbonaceous material has high adsorption performance for various palladium complexes such as palladium catalysts. Therefore, by using the carbonaceous material of the present embodiment, it is possible to suitably remove palladium complexes in various applications.

[0028] The mesopore ratio of the carbonaceous material is 6.4% or more and 50.0% or less. With the mesopore ratio in this range, the carbonaceous material exhibits high adsorption performance for palladium complexes. With the mesopore ratio of 6.4% or more, the carbonaceous material has a high ratio of pores effective for palladium complexes with large molecular sizes, resulting in significantly improved adsorption performance. With the mesopore ratio of 50.0% or less, the pore size of the carbonaceous material does not become too large, making it easy to control the pores that adsorb palladium complexes.

[0029] In this specification, pores in carbonaceous materials are classified according to the pore size (diameter) of the IUPAC (International Union of Pure and Applied Chemistry) as follows: pores with a pore size of less than 2.0 nm are called micropores, pores with a pore size of 2.0 nm or more and 50.0 nm or less are called mesopores, and pores with a pore size of more than 50.0 nm are called macropores. Mesopores are larger than micropores and are effective for adsorption of palladium complexes with large molecular sizes.

[0030] In this specification, the mesopore ratio is calculated as the ratio of the specific surface area of ​​a carbonaceous material calculated by the BET method from an N adsorption isotherm at -196°C (hereinafter also simply referred to as the "BET specific surface area") to the specific surface area of ​​a carbonaceous material calculated by the BJH method from an N adsorption isotherm at -196°C (hereinafter also simply referred to as the "BJH specific surface area"). Mesopores are relatively large pores among the pores that contribute to adsorption in a carbonaceous material. In other words, a larger mesopore ratio indicates better adsorption performance for palladium complexes with large molecular sizes. For specific methods for measuring and calculating the mesopore ratio, see the Examples.

[0031] In order to have higher adsorption performance for various palladium complexes, the mesopore ratio is preferably 10.0% or more and 40.0% or less, and more preferably 15.0% or more and 35.0% or less.

[0032] The carbonaceous material has a Reactive Black pentavalent of 1.0 g / L or more and 8.0 g / L or less. Reactive Black 5 is a dye represented by the following formula (1) and is also called C.I. Reactive Black-5.

[0033]

[0034] Reactive Black 5 has a large molecular weight of 995.88 and a bulky structure, so the pentavalent of Reactive Black serves as an indicator of the adsorption properties of palladium complexes with large molecular sizes. When the pentavalent of Reactive Black is within the above range, the carbonaceous material exhibits high adsorption performance for various palladium complexes. When the pentavalent of Reactive Black is 1.0 g / L or more, the carbonaceous material can ensure a pore volume that suitably adsorbs palladium complexes with large molecular sizes while also retaining a sufficient amount of pores effective for palladium complexes with small molecular sizes, thereby significantly improving adsorption performance. When the pentavalent of Reactive Black is 8.0 g / L or less, the carbonaceous material can retain a sufficient amount of pores effective for palladium complexes with large molecular sizes. Therefore, a carbonaceous material with high adsorption performance, particularly for palladium complexes with large molecular sizes, can be obtained.

[0035] The Reactive Black 5 valence can be calculated, for example, as follows. That is, first, using an ultraviolet-visible spectrophotometer under conditions of a wavelength of 594 nm and an optical path length (cell length) of 10 mm, the absorbance of a test liquid containing Reactive Black 5 and a residual liquid obtained by mixing a carbonaceous material with the test liquid to thoroughly adsorb Reactive Black 5 onto the carbonaceous material and then removing the carbonaceous material to which Reactive Black 5 has been adsorbed are measured. These absorbances are then used to calculate the residual rate (%) of Reactive Black 5 contained in the residual liquid and the adsorption amount ( / g) of Reactive Black 5 per gram of carbonaceous material. Using these values, the Reactive Black 5 valence (g / L) is calculated as the amount of carbonaceous material required to remove 99% of Reactive Black 5 in 1 L of test liquid. In measuring the Reactive Black 5 valence, it is preferable to use a carbonaceous material whose volume-based cumulative distribution 50% particle size (D50) is adjusted to be 9.0 μm or more and 11.0 μm or less. In this specification, the 50% particle size (D50) refers to a value measured as a volume-based median diameter using a laser diffraction light scattering particle size distribution analyzer. For specific methods for measuring and calculating the pentavalent content of Reactive Black, see the Examples.

[0036] Because Reactive Black (5) has higher adsorption performance for various palladium complexes, the concentration of Reactive Black (5) is preferably 1.3 g / L or more and 7.0 g / L or less, more preferably 1.5 g / L or more and 5.0 g / L or less, even more preferably 1.6 g / L or more and 4.0 g / L or less, and even more preferably 1.7 g / L or more and 2.3 g / L or less.

[0037] The iodine adsorption capacity of the carbonaceous material is 1,000 mg / g or more and 1,600 mg / g or less. The iodine adsorption capacity is an index of the surface area of ​​pores present in the carbonaceous material that are capable of physically adsorbing palladium complexes. When the iodine adsorption capacity of the carbonaceous material is within the above range, the carbonaceous material exhibits high adsorption performance for palladium complexes. When the iodine adsorption capacity is 1,000 mg / g or more, there is a sufficient surface area that contributes to physical adsorption, and the adsorption performance for palladium complexes is significantly improved. When the iodine adsorption capacity is 1,600 mg / g or less, the pores of the carbonaceous material do not become too large, making it easier to control the pores that adsorb palladium complexes.

[0038] The iodine adsorption amount is measured and calculated in accordance with JIS K 1474 (2014). For specific methods for measuring and calculating the iodine adsorption amount, see the Examples.

[0039] Since the catalyst has higher adsorption performance for various palladium complexes, the iodine adsorption amount is preferably 1,030 mg / g or more and 1,570 mg / g or less, more preferably 1,055 mg / g or more and 1,550 mg / g or less, and even more preferably 1,100 mg / g or more and 1,350 mg / g or less.

[0040] In the carbonaceous material, the pore volume of mesopores (hereinafter also simply referred to as "mesopore volume") determined by the BJH method from the N adsorption isotherm at -196°C is preferably 0.16 cm 3 / g or more 0.60cm 3 When the pore volume of the mesopores is in the above range, the carbonaceous material tends to be able to achieve a higher level of adsorption performance for various palladium complexes. 3 / g or more, the carbonaceous material can have many relatively large pores that are effective for adsorption of palladium complexes. Therefore, the carbonaceous material tends to have high palladium adsorption performance. 3 / g or less, the pores of the carbonaceous material do not become too large, and the carbonaceous material can have many pores that are effective for adsorption of a palladium complex. Therefore, the carbonaceous material tends to have high palladium adsorption performance. For specific methods for measuring and calculating the pore volume of mesopores, see the Examples.

[0041] Since this tends to realize a higher level of adsorption performance for various palladium complexes, the pore volume of the mesopores is preferably 0.20 cm 3 / g or more 0.59cm 3 / g or less, and more preferably 0.26 cm 3 / g or more 0.58cm 3 / g or less, and more preferably 0.30 cm 3 / g or more 0.57cm 3 / g or less, and even more preferably 0.35 cm 3 / g or more 0.56cm 3 / g or less.

[0042] The carbonaceous material preferably has a specific surface area (i.e., BET specific surface area) determined by the BET method from the N adsorption isotherm at −196° C. of 950 m 2 / g or more 1,700m 2 / g or less. The BET specific surface area is an index showing the degree of progress of activation of a carbonaceous material. When the BET specific surface area is in the above range, it tends to be possible to realize a higher level of adsorption performance for various palladium complexes. 2 When the BET specific surface area is 1,700 m / g or more, the carbonaceous material has a sufficient surface area that contributes to physical adsorption, and tends to exhibit high adsorption performance for palladium complexes. 2 / g or less, the pores of the carbonaceous material do not become too large, and the carbonaceous material tends to have many pores that are effective for adsorption of the palladium complex. For specific methods for measuring and calculating the BET specific surface area, see the Examples.

[0043] Since there is a tendency that the adsorption performance for various palladium complexes can be realized at a higher level, the BET specific surface area is preferably 1,000 m 2 / g or more 1,670m 2 / g, more preferably 1,020 m 2 / g or more 1,650m 2 / g or less, and more preferably 1,100m 2 / g or more 1,550m 2 / g or less, and even more preferably 1330m 2 / g or more 1,500m 2 / g or less.

[0044] The specific surface area of ​​the carbonaceous material determined by the BJH method from the N adsorption isotherm at −196° C. (i.e., the BJH specific surface area) is preferably 23 m 2 / g or more 500m 2 / g or less. The BJH specific surface area is an index showing the amount of mesopores present in a carbonaceous material. When the BJH specific surface area is in the above range, the carbonaceous material tends to be able to achieve a higher level of adsorption performance for various palladium complexes. 2 / g or more, the carbonaceous material can have many relatively large mesopore surfaces that can physically adsorb palladium complexes. Therefore, the carbonaceous material tends to have high palladium adsorption performance. 2 / g or less, the pores of the carbonaceous material do not become too large, and the carbonaceous material can have many pore surfaces that are effective for adsorption of palladium complexes. Therefore, the carbonaceous material tends to have high palladium adsorption performance. For specific methods for measuring and calculating the BJH specific surface area, see the Examples.

[0045] Since the adsorption performance for various palladium complexes tends to be realized at a higher level, the BJH specific surface area is preferably 25 m 2 / g or more 470m 2 / g or less, more preferably 50m 2 / g or more 450m 2 / g or less, and more preferably 100m 2 / g or more 430m 2 / g or less, and even more preferably 150m 2 / g or more 420m 2 / g or less, more preferably 250m 2 / g or more 410m 2 / g or less.

[0046] The pH of the carbonaceous material is preferably 4.5 or more and 9.5 or less. In this embodiment, pH is an index that indicates the electrical properties of the carbonaceous material. When the pH is in the above range, the carbonaceous material tends to have less electrical bias on its surface. Therefore, the carbonaceous material is less susceptible to the electrical properties possessed by the palladium complex, and tends to be able to achieve a higher level of adsorption performance for various palladium complexes. The pH can be measured using a known pH meter, but the examples may be referred to for specific measurement and calculation methods.

[0047] Although the inventors are not sure why the adsorption performance of a carbonaceous material having a pH in the above range is improved, they presume as follows: That is, when the carbonaceous material is immersed in water, the pH in the range of 4.5 to 9.5 means that the hydrogen ion concentration in the water is 10 -4.5 mol / L or more 10 -9.5 mol / L or less. This means that, for example, even if the carbonaceous material has acid-dissociable groups on its surface, the amount of hydrogen ions liberated from the groups is sufficiently small. Also, for example, even if the carbonaceous material contains metal hydroxides or the like adsorbed on its surface as impurities, the amount of hydroxide ions liberated from the metal hydroxides is sufficiently small.

[0048] Therefore, when the pH is in the range of 4.5 to 9.5, the surface of the carbonaceous material is nearly electrically neutral and in a more hydrophobic state, and therefore the carbonaceous material has improved physical adsorption properties for electrically neutral substances, and its adsorption performance is also superior, for example, for electrically neutral palladium complexes such as bis(dibenzylideneacetone)palladium(0).

[0049] Furthermore, when the pH is in the range of 4.5 to 9.5, most of the acid-dissociable groups present on the surface of the carbonaceous material remain undissociated. Such groups can react favorably with relatively acidic metal ions, such as palladium (II) ions, to form metal-oxygen bonds, such as Pd—O bonds, while dissociating hydrogen ions. As a result, the carbonaceous material has excellent adsorption performance, even for relatively acidic palladium (II) complexes, such as palladium acetate.

[0050] From the above, it is presumed that when the pH is in the range of 4.5 to 9.5, the carbonaceous material has superior adsorption properties for both electrically neutral palladium complexes and relatively acidic palladium (II) complexes, and therefore the carbonaceous material can achieve a higher level of adsorption properties for various palladium complexes. Examples of acid-dissociable groups include hydroxyl groups and carboxyl groups. However, the reason is not limited to these.

[0051] Since this tends to enable the realization of even higher levels of adsorption performance for various palladium complexes, the pH is preferably 5.0 or more and 9.0 or less, more preferably 5.5 or more and 8.5 or less, and even more preferably 6.0 or more and 8.0 or less.

[0052] In the carbonaceous material, the packing density measured by the tapping method (hereinafter also simply referred to as "packing density") is preferably 0.20 g / mL or more and 0.55 g / mL or less. The packing density tends to be significantly affected by the pore volume of the carbonaceous material. Therefore, when the packing density is measured using a carbonaceous material in which the 50% particle diameter (D50) of the volume-based cumulative distribution is adjusted to 9.0 μm or more and 11.0 μm or less, the packing density value serves as an index of the pore volume possessed by the carbonaceous material. When the packing density is within the above range, the carbonaceous material tends to be able to achieve a higher level of adsorption performance for various palladium complexes. When the packing density is 0.20 g / mL or more, there tends to be a sufficient number of pores contributing to physical adsorption. Therefore, the carbonaceous material tends to have a higher adsorption performance for palladium complexes. When the packing density is 0.55 g / mL or less, the pores of the carbonaceous material do not become too large, and many pores effective for adsorption of palladium complexes can be possessed. Therefore, carbonaceous materials tend to have high palladium adsorption performance. For specific methods of measuring and calculating the packing density, see the Examples.

[0053] Since this tends to enable the realization of even higher levels of adsorption performance for various palladium complexes, the packing density is preferably 0.25 g / mL or more and 0.50 g / mL or less.

[0054] The shape of the carbonaceous material varies depending on the application and is not particularly limited. Examples of such shapes include powder, lump, crushed, sphere, cylinder, elliptical cylinder, elliptical truncated cone, and polygonal prism such as triangular prism, quadrangular prism, pentagonal prism, and hexagonal prism, as well as rod shapes, pellet shapes such as solid pellets and hollow pellets, substrate shapes (sheet shapes), and block shapes.

[0055] The powdered carbonaceous material is used, for example, in batch processing and as a raw material for molding. In this specification, the term "powdered" refers to, for example, fine powder, powder, fine grains, and granular powder, and typically has a 50% particle size (D50) of a cumulative volume distribution of 1 μm or more and 150 μm or less.

[0056] Crushed carbonaceous materials are used, for example, in flow-through processes and chromatographic columns, etc. In this specification, the term "crushed" refers to particles that are not uniform in shape but have any shape, usually with corners.

[0057] For example, when used in a column or the like, the shape is preferably cylindrical. In this specification, the term "cylindrical shape" does not necessarily mean a strict cylindrical shape geometrically, but includes cylindrical shapes whose cross-sectional shape in a plane perpendicular to the central axis of the cylinder (hereinafter simply referred to as "cross-sectional shape") is oval, right circular, and elliptical, and also includes cylinders that are slightly curved or have a slightly uneven surface. In this specification, a right circular or elliptical shape means, for example, a shape whose ratio of the major axis to the minor axis (major axis / minor axis) is 3 or less. As the cross-sectional shape, circular and elliptical shapes are preferred because they enable the carbonaceous material to be packed more densely into a column or the like.

[0058] When the carbonaceous material has a cylindrical shape, the diameter of the cross-sectional shape varies depending on the application, but is typically about 1.0 mm or more and 10.0 mm or less when used in a column, for example. In this specification, "diameter" means the diameter of a circle when the cross-sectional shape is circular. On the other hand, when the cross-sectional shape is oval, elliptical, or elliptical, "diameter" means the longest direction (i.e., the long axis direction) in those shapes. In this specification, "circular" includes not only a perfect circle, but also an oval, a right circle, and an ellipse.

[0059] When the carbonaceous material has a cylindrical shape, the length of the cylinder in the longitudinal direction varies depending on the application, but for example, when used in a column or the like, it is usually about 1.0 mm or more and 20.0 mm or less.

[0060] When the carbonaceous material is in the form of pellets, the planar shape thereof can be, for example, a shape that can be applied to a column or the like. Examples of such shapes include, in planar view, a circular, elliptical, rectangular, rod-like, and distorted shape. When the carbonaceous material is in the form of pellets, the thickness thereof is not particularly limited, and known adsorbents that are applied to columns or the like can be used as reference. The thickness is preferably a thickness that can be applied to a column or the like, and is typically 100 μm or more and 10,000 μm or less.

[0061] When the carbonaceous material is in the form of a cylindrical pellet, the diameter of the pellet is preferably 2 mm or more and 10 mm or less, and the aspect ratio is preferably 1:1 to 1:10. Such pellets are suitable as adsorbents in columns and the like. In this specification, the aspect ratio refers to the ratio of the diameter to the height of a single carbonaceous material, i.e., the diameter of the carbonaceous material: the height of the carbonaceous material. The aspect ratio refers to the average aspect ratio of 30 randomly selected carbonaceous materials.

[0062] The carbonaceous material is preferably activated carbon.

[0063] [Method for Producing Carbonaceous Material] The carbonaceous material of this embodiment can be obtained by a known production method.

[0064] Examples of such methods 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 these production methods, it tends to be easier to produce a carbonaceous material having a mesopore ratio of 6.4% to 50.0%, a pentavalent reactive black of 1.0 g / L to 8.0 g / L, and an iodine adsorption of 1,000 mg / g to 1,600 mg / g.

[0065] The method for producing a carbonaceous material according to the present embodiment includes a carbonization step of carbonizing a raw material to obtain a carbonized product, and an activation step of activating the carbonized product to obtain an activated product. The method for producing a carbonaceous material according to the present embodiment preferably includes a cleaning step of cleaning the activated product.

[0066] (Carbonization Step) The method for producing a carbonaceous material includes a carbonization step of carbonizing a raw material to obtain a carbonized product. The raw material is not particularly limited as long as it can be used to obtain the desired carbonaceous material. Examples of raw materials include plant-based or fossil-based raw materials such as wood, wood flour, fruit shells such as coconut shells, seeds such as palm kernels, plums, and peaches, by-products of pulp production, bagasse, blackstrap molasses, coal (peat, lignite, brown coal, bituminous coal, etc.), anthracite, petroleum distillation residue components, petroleum pitch, coke, and coal tar; various synthetic resins such as phenolic resins, vinyl chloride resins, vinyl acetate resins, melamine resins, urea resins, resorcinol resins, celluloid, epoxy resins, polyurethane resins, polyester resins, acrylic resins, and polyamide resins; synthetic rubbers such as polybutylene, polybutadiene, and polychloroprene; other synthetic woods; and synthetic pulp. These raw materials can be used alone or in combination of two or more types in any ratio depending on the required specifications.

[0067] The raw material is preferably a natural product, and more preferably at least one selected from the group consisting of coconut shells and wood flour. Use of such a raw material tends to make it easier to produce a carbonaceous material having a mesopore ratio of 6.4% to 50.0%, a Reactive Black pentavalent of 1.0 g / L to 8.0 g / L, and an iodine adsorption capacity of 1,000 mg / g to 1,600 mg / g.

[0068] The raw materials may contain additives, etc., as necessary. The additives, etc. may also be added to the carbonized material, as necessary. Examples of such additives include water, coal tar, anhydrous tar, hard pitch, coal tar-based pitch, and petroleum-based pitch. The additives, etc. may be used alone or in combination of two or more. The additives, etc. are typically blended in an amount of 1.0 to 50.0 parts by mass per 100 parts by mass of the raw materials or carbonized material. The total amount of the additives, etc., is typically 1 to 100 parts by mass per 100 parts by mass of the raw materials or carbonized material. When mixing the raw materials or carbonized material with the additives, the amount of oxygen in the raw materials or carbonized material may be adjusted in advance, as necessary, to a range of 1.0 to 20.0% by mass per 100% by mass of the raw materials or carbonized material. The adjustment of the oxygen amount can be performed, for example, by mixing the raw materials or carbonized material with oxygen under heating at a temperature of 150 to 300°C.

[0069] In the method for producing a carbonaceous material, the raw material may be pulverized or molded before being carbonized. Examples of such methods include a method in which the raw material is pulverized into powder using a known pulverizer before being carbonized, and then carbonized. Another example is a method in which the raw material is molded into pellets by a known method before being carbonized, and then carbonized.

[0070] When the raw material is in the form of powder, the particle size of the powder (50% particle size of cumulative volume distribution, D50) is preferably 1 μm or more and 150 μm or less.

[0071] The method for carbonizing the raw material is not particularly limited, and examples thereof include a method in which the raw material is heated to 300° C. or higher and 900° C. or lower, preferably 400° C. or higher and 800° C. or lower, under oxygen-free conditions.

[0072] The carbonization time can be appropriately set depending on the raw material and the equipment used for carbonization. The carbonization time is, for example, 15 minutes to 20 hours, and preferably 30 minutes to 10 hours. The carbonization treatment can be carried out using known manufacturing equipment such as a rotary kiln. The carbonization treatment may be carried out under reduced pressure by excluding air, or may be carried out in a nitrogen atmosphere.

[0073] In the method for producing a carbonaceous material, the carbide may be pulverized into a powder using a known pulverizer. This tends to make it easier to produce a carbonaceous material having a mesopore ratio of 6.4% to 50.0%, a Reactive Black pentavalent of 1.0 g / L to 8.0 g / L, and an iodine adsorption of 1,000 mg / g to 1,600 mg / g. In the method for producing a carbonaceous material, after pulverizing the carbide into a powder, additives and the like may be added to the powdered carbide as needed, and the resulting kneaded product may be molded by a known method.

[0074] When the carbide is in the form of powder, the particle size of the carbide (50% particle size of cumulative volume distribution, D50) is preferably 1 μm or more and 150 μm or less.

[0075] In the method for producing a carbonaceous material, a carbide, a powdered carbide, a kneaded product, or a powdered kneaded product may be molded into a cylindrical pellet using a known method. This tends to more easily produce a carbonaceous material having a mesopore ratio of 6.4% to 50.0%, a pentavalent reactive black of 1.0 g / L to 8.0 g / L, and an iodine adsorption of 1,000 mg / g to 1,600 mg / g. When the carbide is formed into a cylindrical pellet shape, the diameter of the cylindrical pellet is preferably 0.1 mm to 4.0 mm. The aspect ratio (diameter:height) of the cylindrical pellet is preferably 1:1 to 1:10.

[0076] The carbonization step yields a carbonized product of the raw material.

[0077] The method for producing a carbonaceous material may include a washing step and / or a drying step in which the carbonized material is subjected to a washing treatment and / or a drying treatment after the carbonization step. The conditions for these steps are not particularly limited, and known conditions can be used. In addition, the following washing step and drying step may be referred to.

[0078] (Activation Step) The method for producing a carbonaceous material includes an activation step of activating a carbonized material to obtain an activated material.

[0079] Known methods can be used for the activation treatment. Examples of such methods include activation methods using activated gases such as water vapor, oxygen, and carbon dioxide. Known manufacturing equipment such as a rotary kiln, a fluidized bed furnace, and a sleeve furnace (vertical furnace) can be used for the activation treatment. The activation treatment may be carried out under reduced pressure by excluding air, or may be carried out under a nitrogen atmosphere. For example, when water vapor is used, the activation treatment may involve contacting the water vapor with the carbide at a flow rate of 10 liters (L) to 300 liters (L) per minute for 1 minute to 1,440 minutes. Note that an inert gas such as nitrogen may be used in combination with the activated gas.

[0080] The activation treatment is preferably carried out using a rotary kiln. By using a rotary kiln, the activated material, which becomes lighter as the activation of the carbide progresses, can remain in the kiln without scattering outside the furnace. This allows the carbide to be activated more sufficiently, which tends to result in an activated material with sufficiently developed pores that are effective for adsorption of the palladium complex.

[0081] Furthermore, the use of a rotary kiln makes it possible to efficiently bring the carbide into contact with the activated gas, which tends to favorably produce a carbonaceous material that has high adsorption performance for various palladium complexes such as palladium catalysts.

[0082] When activation treatment is performed using a rotary kiln, the carbide fed into the rotary kiln preferably has a particle size of 70 mesh (opening size: 243 μm) over sieve and 2 mesh under sieve (opening size: 10.7 mm) using a standard sieve mesh specified in JIS Z8801-1:2019, more preferably 32 mesh (opening size: 490 μm) over sieve and 2 mesh under sieve (opening size: 10.7 mm). By having the particle size of the carbide within the above range, the activated material, whose mass becomes lighter as activation of the carbide progresses, remains in the kiln longer, enabling activation to be performed more efficiently. As the carbide, carbide whose particle size has been adjusted by cutting the raw material to the desired size before the carbonization step may be used, or carbide whose particle size has been adjusted by crushing and classifying the carbide to the desired size may be used.

[0083] The temperature for the activation treatment is not particularly limited, but is preferably 750° C. or higher and 1,200° C. or lower, and more preferably 800° C. or higher and 1,100° C. or lower. Activation treatment at such a temperature tends to make it easier to produce a carbonaceous material having a mesopore ratio of 6.4% or higher and 50.0% or lower, a Reactive Black pentavalent of 1.0 g / L or higher and 8.0 g / L or lower, and an iodine adsorption of 1,000 mg / g or higher and 1,600 mg / g or lower.

[0084] The partial pressure of the active gas is, for example, 10% or more and 100% or less, and preferably 30% or more and 100% or less.

[0085] As the active gas, oxygen gas and carbon dioxide gas are preferably used together with water vapor gas. In this case, the partial pressure of the water vapor is preferably greater than 40.0 vol% and less than 60.0 vol%, more preferably 45.0 vol% or more and 55.0 vol% or less. The partial pressure of the oxygen gas is preferably greater than 5.0 vol% and less than 20.0 vol%, more preferably 7.0 vol% or more and 15.0 vol% or less. The partial pressure of the carbon dioxide gas is preferably greater than 1.0 vol% and less than 15.0 vol%, more preferably 3.0 vol% or more and 10.0 vol% or less. Note that an inert gas such as nitrogen may be included as another gas. In this case, the partial pressure of the inert gas is preferably greater than 5.0 vol% and less than 54.0 vol%, more preferably 20.0 vol% or more and 25.0 vol% or less. When these proportions are within the above ranges, it tends to be possible to more easily produce a carbonaceous material having a mesopore proportion of 6.4% or more and 50.0% or less, a pentavalent reactive black of 1.0 g / L or more and 8.0 g / L or less, and an iodine adsorption of 1,000 mg / g or more and 1,600 mg / g or less.

[0086] The activation time can be appropriately set depending on conditions such as the raw material, activation temperature, and production equipment. The activation time is, for example, 20 minutes to 48 hours, preferably 30 minutes to 36 hours, more preferably 40 minutes to 24 hours, even more preferably 45 minutes to 120 minutes, and even more preferably 50 minutes to 100 minutes. When the activation time is within the above range, it tends to be easier to produce a carbonaceous material having a mesopore ratio of 6.4% to 50.0%, a Reactive Black pentavalent of 1.0 g / L to 8.0 g / L, and an iodine adsorption of 1,000 mg / g to 1,600 mg / g.

[0087] An example of an activation device for performing activation treatment is a rotary kiln as shown in Figures 1 and 2. Figure 1 shows a cross-sectional view I and a side view II of a rotary kiln. Figure 2 is a schematic cross-sectional view for explaining the rotary kiln.

[0088] 1 and 2, a rotary kiln typically includes a tubular body 1 and agitating blades A to F arranged on the inner wall surface of the tubular body 1. The active gas is typically sent from one side to the other, i.e., in the case of a rotary kiln as shown in FIGS. 1 and 2, the active gas is sent in the tubular body 1 in the direction of flow 2 of the active gas.

[0089] The material of the tube body 1 is not particularly limited as long as it is a material that can be used in a rotary kiln, and examples thereof include stainless steel.

[0090] 1 and 2, the number of stirring blades is six, but this can be adjusted appropriately depending on the amount of carbonized material 5 charged as the raw material. The number of stirring blades is usually from 1 to 20, preferably from 3 to 12, and more preferably from 5 to 10. The stirring blades are preferably installed at equal intervals around the central axis of the tubular body 1. For example, if there are six stirring blades, they will be installed every 60° around the central axis of the tubular body 1.

[0091] The height of the agitating blade (height from the wall toward the center of the tubular body 1) can be set appropriately depending on the size of the tubular body 1 and the amount of carbonized material 5 charged, but it is preferable that the height be such that the agitating blade is not covered by the carbonized material 5 charged in the tubular body 1 and is visible. Specifically, when the agitating blade is located at the bottommost surface of the tubular body 1 (the position of agitating blade B in the right diagram of Figure 2), the height of the agitating blade is preferably such that the agitating blade is covered by the carbonized material 5 by 1 / 2 to 2 / 3 from the bottommost surface. It is more preferable that the height of the agitating blade is 10% to 30% of the inner radius of the tubular body 1.

[0092] The thickness of the stirring blade (thickness in the direction of rotation 3 of the tubular body 1) can be set appropriately depending on the size of the tubular body 1 and the amount of carbonized material 5 charged, but it is preferable that the thickness be such that the stirring blade has enough strength to not be damaged by the carbonized material 5 charged into the tubular body 1. Specifically, the thickness of the stirring blade is usually 1% or more and 100% or less of the wall thickness of the tubular body 1, preferably 20% or more and 90% or less, and more preferably 30% or more and 95% or less.

[0093] The material of the stirring blades is not particularly limited as long as it is a material that can be used in a rotary kiln, and examples thereof include stainless steel.

[0094] By arranging the stirring blades in the tubular body 1 in this manner, the contact efficiency between the carbide 5 and the active gas tends to be further improved, which tends to make it easier to produce a carbonaceous material having a desired specific surface area.

[0095] As shown in Figure 2, an appropriate amount of carbide 5 is charged inside tubular body 1. As tubular body 1 rotates in tubular rotation direction 3, for example, carbide 5 captured by agitating blade A is lifted by agitating blade A, and then moves toward carbide falling direction 4, passing over agitating blade A while being mixed, and contacts and is activated with the activated gas, and is then captured between agitating blades A and B. As tubular body 1 rotates in this manner, carbide 5 is mixed while passing over agitating blades A to F, and is activated by efficient and uniform contact with the activated gas. This tends to make it easier to produce a carbonaceous material having a desired pore size distribution.

[0096] In this way, by using a rotary kiln as an activation device, it tends to be possible to more easily produce a carbonaceous material having a mesopore ratio of 6.4% or more and 50.0% or less, a pentavalent reactive black of 1.0 g / L or more and 8.0 g / L or less, and an iodine adsorption of 1,000 mg / g or more and 1,600 mg / g or less.

[0097] The activation step yields an activated product.

[0098] The method for producing a carbonaceous material may include a washing step and / or a drying step, in which the activated material is subjected to a washing treatment and / or a drying treatment, etc., after the activation step. The conditions for these steps are not particularly limited, and known conditions can be adopted. In addition, the following washing step and drying step may be referred to.

[0099] (Washing Step) The carbonaceous material is preferably obtained through a washing step in which the activated product obtained in the activation step is washed. The washing is more preferably acid washing. By undergoing such a washing step, it tends to be easier to produce a carbonaceous material having a mesopore ratio of 6.4% to 50.0%, a Reactive Black pentavalent of 1.0 g / L to 8.0 g / L, and an iodine adsorption of 1,000 mg / g to 1,600 mg / g.

[0100] Examples of the acid used in the acid washing include mineral acids such as hydrochloric acid and nitric acid, and organic acids such as formic acid and acetic acid. These acids may be used alone or in combination of two or more.

[0101] The acid concentration, and the temperature and time for acid washing may be adjusted as appropriate so as to obtain the desired carbonaceous material.

[0102] (Drying Step) The carbonaceous material is preferably obtained through a drying step in which the washed product obtained in the washing step is dried.

[0103] The drying method is not particularly limited, and known drying methods such as natural drying, heat drying, and hot air drying can be used. As the drying method, a method of heating and / or reducing pressure is preferred. As a method of drying by heating, a hot air drying method is preferred because it allows for stable drying without uneven drying. Regarding drying conditions, it is preferable to dry the carbonaceous material until the moisture content is 20.0 mass% or less, and more preferably until the moisture content is 10.0 mass% or less.

[0104] Examples of the heating method include heating methods using a stationary constant temperature dryer, a stationary hot air dryer, a vacuum dryer, a rotary evaporator, or a mixing dryer such as a conical dryer or a Nauta dryer. The heating temperature may be any temperature at which the carbonaceous material hardens but does not melt, and is preferably, for example, 40°C or higher and 300°C or lower.

[0105] Examples of the pressure reduction method include a pressure reduction method using an oil pump, an oil-less pump, an aspirator, etc. The pressure in the pressure reduction method is usually 0.00001 MPa or more and 0.05 MPa or less.

[0106] The drying time varies depending on the drying temperature, but is usually about 1 minute to 20 hours.

[0107] The carbonaceous material thus obtained may be used as is, or may be subjected to known methods as necessary to adjust the particle size by crushing, pulverizing, and classifying; to further purify the material by additional washing using, for example, water, an organic solvent, an aqueous acid solution, or an aqueous alkali solution; or to impart durability and adjust the structure by additional heat treatment, thereby obtaining a carbonaceous material.

[0108] [Applications] The carbonaceous material can be suitably used in various applications for removing, adsorbing, concentrating, and recovering various palladium complexes, such as palladium catalysts. Such applications may involve an appropriate combination of removal, adsorption, concentration, and recovery operations. Examples of such applications include wastewater treatment, waste oil treatment, catalyst recovery from reaction solutions, decolorization of products, and removal, concentration, and adsorption of impurities from reaction solutions.

[0109] The carbonaceous material is suitably used for adsorbing a palladium complex in an organic solvent, and more suitably used for adsorbing a zero-valent palladium complex and / or a divalent palladium complex in an organic solvent.

[0110] Examples of zero-valent palladium complexes include bis(dibenzylideneacetone)palladium(0) and tetrakis(triphenylphosphine)palladium(0). As the zero-valent palladium complex, bis(dibenzylideneacetone)palladium(0) is preferred because it has higher adsorption performance.

[0111] Examples of divalent palladium complexes include palladium(II) acetate, palladium(II) chloride, and dichlorobis(triphenylphosphine)palladium(II). Palladium(II) acetate is preferred as the divalent palladium complex because it has higher adsorption performance.

[0112] Examples of organic solvents include methylene chloride, chloroform, carbon tetrachloride, ethylene chloride, trichloroethylene, tetrachloroethylene, o-dichlorobenzene, m-dichlorobenzene, Freon-112, Freon-113, HCFC, HFC, propyl bromide, butyl iodide, acetic acid, methyl acetate, ethyl acetate, propyl acetate, butyl acetate, methyl methacrylate, diethyl carbonate, ethyl formate, diethyl ether, dipropyl ether, tetrahydrofuran, dibutyl ether, anisole, methanol, ethanol, isopropanol, n-butanol, 2-butanol, isobutanol, t-butanol, allyl alcohol, pentanol, heptanol, ethylene glycol, diene Examples of the organic solvent include ethylene glycol, phenol, o-cresol, m-cresol, p-cresol, xylenol, acetaldehyde, acetone, methyl ethyl ketone, methyl isobutyl ketone, cyclohexanone, phorone, acetonitrile, acrylonitrile, n-hexane, isohexane, cyclohexane, methylcyclohexane, n-heptane, n-octane, n-nonane, isononane, decane, dodecane, undecane, tetradecane, decalin, benzene, toluene, m-xylene, o-xylene, p-xylene, ethylbenzene, 1,3,5-trimethylbenzene, n-methylpyrrolidone, dimethylformamide, dimethylacetamide, and dimethyl sulfoxide. These organic solvents may be used alone or in combination.

[0113] [Method for Adsorbing Palladium Complex] The method for adsorbing a palladium complex according to the present embodiment includes an adsorption step of adsorbing a palladium complex onto a carbonaceous material. Examples of the method for adsorbing a palladium complex include a method of adsorbing a palladium complex onto a carbonaceous material and concentrating the palladium complex in the carbonaceous material. In addition to using the carbonaceous material according to the present embodiment as the carbonaceous material, the concentration method may include the same steps as known methods for adsorbing, concentrating, and recovering metal palladium.

[0114] In the adsorption step, for example, the palladium complex is brought into contact with the carbonaceous material, thereby causing the palladium complex to be adsorbed onto the carbonaceous material.

[0115] [Apparatus] The apparatus includes a carbonaceous material. The apparatus may have the same configuration as a known apparatus, except that the carbonaceous material of this embodiment is used as the carbonaceous material.

[0116] The functions of the carbonaceous material are utilized by an apparatus containing the carbonaceous material. The apparatus is preferably a treatment apparatus. In this specification, the term "treatment apparatus" is not particularly limited as long as it is an apparatus that can remove, adsorb, concentrate, and recover various palladium complexes, such as palladium catalysts, contained in treatment targets such as wastewater, waste liquid, and oil, using the carbonaceous material of this embodiment. Such a treatment apparatus may be an apparatus that appropriately combines the operations of removal, adsorption, concentration, and recovery. Examples of such treatment apparatus include apparatuses that include filters, columns, tanks or baths, tubes, cartridges, cylinders, and sheets containing a carbonaceous material (hereinafter also simply referred to as "filters, etc. containing a carbonaceous material"), as well as filtration apparatuses, adsorption apparatuses, and concentration apparatuses.

[0117] The device includes, for example, an adsorption section for contacting the palladium complex with the carbonaceous material. The adsorption section may contain an adsorbent other than the carbonaceous material according to the present embodiment, as needed. Examples of such adsorbents include activated carbon, zeolite, silica gel, activated alumina, nonwoven fabric, and porous organic compounds other than the carbonaceous material according to the present embodiment.

[0118] Filtration devices include, for example, cartridge filters, membrane treatment devices, and ultrafiltration membrane devices, including carbonaceous materials.

[0119] The treatment device may include other adsorption filters in addition to the filter containing a carbonaceous material, etc. Examples of such other adsorption filters include metal filters made of stainless steel, aluminum, bronze, copper, titanium, nickel, etc.; and resin filters made of polypropylene, polyvinyl chloride, polyvinylidene chloride, polyethylene, polyamide, fluorine-based resin, etc.

[0120] The processing equipment may be of a batch type or a continuous type, and the carbonaceous material may be used in either type.

[0121] EXAMPLES The present invention will be explained in more detail below by showing examples and comparative examples, but the present invention is not limited to these examples in any way.

[0122] [Evaluation Method] (1) BET Specific Surface Area The specific surface area (m) of a carbonaceous material determined by the BET method from the N adsorption isotherm at -196°C. 2 Specifically, the BET specific surface area (m 2 / g) was determined as follows. That is, first, using a specific surface area / pore distribution measuring device (BELSORP (registered trademark)-mini II (trade name) manufactured by Microtrac-Bell Corporation), the carbonaceous material was heated at 250°C for 3 hours under reduced pressure (degree of vacuum: 0.1 kPa or less), and then the nitrogen adsorption isotherm of the carbonaceous material at -196°C was measured. Using the obtained nitrogen adsorption isotherm, a straight line was obtained from the obtained curve by BET analysis using the multipoint method in the region of relative pressure P / P0 = 0.01 or more and 0.10 or less, and the BET specific surface area was calculated from this straight line.

[0123] (2) Mesopore volume The pore volume (cm) of the mesopores of the carbonaceous material determined by the BJH method from the N adsorption isotherm at -196 °C. 3 / g) was measured. Specifically, using the nitrogen adsorption isotherm used in the calculation of the BET specific surface area above, a curve was obtained by BJH analysis in the relative pressure region of P / P0 = 0.385 or more and 0.99 or less. From the obtained curve, the cumulative pore volume for each pore diameter was calculated, and the pore volume of mesopores with pore diameters of 2.0 nm or more and 50.0 nm or less was calculated by subtracting the cumulative pore volume for pore diameters of 2.0 nm or less from the cumulative pore volume for pore diameters of 50.0 nm or less.

[0124] (3) BJH specific surface area: The specific surface area (m) of a carbonaceous material determined by the BJH method from the N adsorption isotherm at -196 °C. 2 / g) was measured. The BJH specific surface area is the specific surface area determined from the pore volume and pore diameter of the carbonaceous material measured based on the BJH method. Specifically, using the nitrogen adsorption isotherm used in the calculation of the BET specific surface area above, a curve was obtained by BJH analysis in the relative pressure region P / P0 = 0.385 or more and 0.99 or less. From the obtained curve, the pore volume of mesopores was calculated for each pore diameter in the pore diameter range of 2.0 nm or more and 50.0 nm or less, and the specific surface area was calculated using these values ​​and the following formula (I). The BJH specific surface area of ​​the carbonaceous material was calculated by adding up the obtained specific surface areas for each pore diameter. Ap = 2 × Vp / (rp × 10 7 ) × 0.0001 (I) In the formula (I), Ap is the specific surface area (m 2 / g), and Vp indicates the pore volume (cm 3 / g), and rp indicates the pore diameter (nm).

[0125] (4) Mesopore ratio The mesopore ratio (%) of the carbonaceous material was calculated using the carbonaceous material. Specifically, the mesopore ratio (%) of the carbonaceous material was calculated by multiplying the BET specific surface area (m 2 / g) and BJH specific surface area (m 2 / g) was used to calculate the mesopore ratio according to the following formula (II): Mesopore ratio = BJH specific surface area / BET specific surface area × 100 (II)

[0126] (5) Reactive Black Pentavalent The Reactive Black pentavalent (g / L) was measured using a carbonaceous material. Specifically, the carbonaceous material was first pulverized to a volume-based cumulative distribution of 50% particle size (D50) of approximately 10.0 μm or less, and then dried for 3 hours in a constant temperature dryer (Yamato Scientific Co., Ltd., DVS402 (trade name)) at 115°C. The material was then allowed to cool to room temperature in a desiccator using silica gel as a desiccant, yielding a cooled carbonaceous material.

[0127] Separately, test solution A containing phosphate buffer and Reactive Black 5 (Sigma-Aldrich) was prepared as follows. First, 7.26 g of potassium dihydrogen phosphate (Fujifilm Wako Pure Chemical Industries, Ltd.) and 28.66 g of disodium hydrogen phosphate dodecahydrate (Fujifilm Wako Pure Chemical Industries, Ltd.) were dissolved in 2 L of distilled water to prepare a phosphate buffer (pH: 7.0). Then, approximately 0.5 g to 1.2 g of Reactive Black 5 was added to 1 L of the resulting phosphate buffer to prepare test solution A. The amount of Reactive Black 5 was adjusted as follows: Specifically, the amount of Reactive Black 5 added to 1 L of phosphate buffer was appropriately adjusted so that the absorbance of a solution obtained by diluting the resulting test solution A 20-fold with distilled water was in the range of 1.18 to 1.23. The absorbance was measured at a wavelength of 594 nm using a glass cell with an optical path length of 10 mm with an ultraviolet-visible spectrophotometer (double beam spectrophotometer U-2910 (trade name) manufactured by Hitachi High-Tech Corp.). Test solution A obtained as described above was diluted 20 times to give test solution B, which was used in the absorbance measurements described below.

[0128] Next, an arbitrary mass of the carbonaceous material after cooling (an amount such that the residual rate of Reactive Black 5 contained in the filtrate is about 10% according to the following formula (IV)) was dispensed into a 100 mL Erlenmeyer flask with a stopper, and the carbonaceous material was added to 50 mL of the test liquid A prepared above. The mixture was shaken at a speed of 150 times / min for 5 hours in a water bath at 40 ° C. using a constant temperature shaking bath (Water Bath Shaker MM-10 (trade name) manufactured by Taitec Corporation) to obtain a mixed solution. Thereafter, the mixed solution was filtered using a membrane filter (DISMIC (registered trademark) 25HP045AN (trade name) manufactured by Advantec Toyo Co., Ltd.) to obtain a filtrate.

[0129] The absorbance at a wavelength of 594 nm of each of the obtained test solution B and the filtrate was measured using a glass cell with an optical path length of 10 mm and an ultraviolet-visible spectrophotometer (double-beam spectrophotometer U-2910 (product name) manufactured by Hitachi High-Tech Corporation). Using these absorbances, the amount of Reactive Black 5 adsorbed per 1 g of carbonaceous material (hereinafter referred to as "RB5 adsorption amount ( / g) per 1 g of carbonaceous material") was calculated using the following formula (III): RB5 adsorption amount ( / g) per 1 g of carbonaceous material = (absorbance of test solution B at a wavelength of 594 nm × 20 - absorbance of filtrate at a wavelength of 594 nm) / mass (g) of carbonaceous material (III)

[0130] The residual rate of Reactive Black 5 contained in the filtrate (hereinafter simply referred to as "RB5 residual rate (%)") was calculated using the following formula (IV): 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 (IV)

[0131] Next, a power approximation curve was created using the RB5 residual rate (%) on the horizontal axis and the RB5 adsorption amount ( / g) per 1 g of carbonaceous material on the vertical axis. Using this power approximation formula, the adsorption amount of Reactive Black 5 when the Reactive Black 5 residual rate was 1% (hereinafter simply referred to as the "RB5 adsorption amount ( / g) when the RB5 residual rate is 1%) was determined, and the Reactive Black 5 valence (g / L) was calculated using formula (V): Reactive Black 5 valence (g / L) = (absorbance of test solution B at a wavelength of 594 nm × 20 × 0.99 / RB5 adsorption amount ( / g) when the RB5 residual rate is 1%) / 0.05 (L) (V) Note that 0.05 (L) in formula (V) is the volume of the test solution.

[0132] (6) Iodine Adsorption Amount (Iodine Adsorption Performance) The iodine adsorption amount (mg / g) of the carbonaceous material was measured and calculated. Specifically, the iodine adsorption amount was measured in accordance with JIS K 1474 (2014). That is, first, in accordance with JIS Z 8801-1, the carbonaceous material was pulverized until 90% or more passed through a 45 μm mesh sieve, and then dried for 3 hours in a constant temperature dryer (DVS402 (trade name) manufactured by Yamato Scientific Co., Ltd.) at 115°C. Thereafter, the material was allowed to cool to room temperature in a desiccator using silica gel as a desiccant, and a carbonaceous material after cooling was obtained.

[0133] Meanwhile, 25.0 g of potassium iodide (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) and 13.0 g of iodine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were dissolved in approximately 1 L of distilled water to prepare an iodine solution. The iodine solution was titrated with a 0.1 mol / L sodium thiosulfate solution (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.), and distilled water was added appropriately to the iodine solution to prepare a 0.05 mol / L iodine solution.

[0134] Next, an arbitrary amount of the carbonaceous material after cooling (an amount such that the residual iodine concentration in the supernatant of the filtrate described below is approximately 2.5 g / L) was weighed and placed in a 100 mL Erlenmeyer flask with a stopper, and 50 mL of the 0.05 mol / L iodine solution was added to the entire volume using a pipette. At room temperature (20 ° C or higher and 30 ° C or lower), the mixture was shaken at 200 rpm for 15 minutes using a shaker (medium-sized shaker Reciprocating Shaker NR-10 (trade name) manufactured by Taitec Co., Ltd.) to adsorb iodine to the carbonaceous material, resulting in a mixed solution. Thereafter, the mixed solution was filtered using a cellulose mixed ester membrane filter (A045A025A (trade name) manufactured by Advantec Toyo Co., Ltd.) to obtain a filtrate. 10 mL of the supernatant of the filtrate was collected with a pipette and titrated with 0.1 mol / L sodium thiosulfate solution (Fujifilm Wako Pure Chemical Industries, Ltd., factor: 1.000). The residual iodine concentration was calculated using the following formula (VI): residual iodine concentration (g / L) = amount (mL) of 0.1 mol / L sodium thiosulfate solution used in titration × factor of 0.1 mol / L sodium thiosulfate solution × 12.69 / 10 (VI)

[0135] The amount of iodine adsorption per 1 g of carbonaceous material was calculated using the following formula (VII): Amount of iodine adsorption per 1 g of carbonaceous material = (10 × factor of 0.05 mol / L iodine solution - amount (mL) of 0.1 mol / L sodium thiosulfate solution used in titration × factor of 0.1 mol / L sodium thiosulfate solution) × 12.69 × 5 / mass (g) of carbonaceous material

[0136] The factor of the 0.05 mol / L iodine solution was calculated using the formula (VIII): Factor of 0.05 mol / L iodine solution = (amount (mL) of 0.1 mol / L sodium thiosulfate solution used in titration × factor of 0.1 mol / L sodium thiosulfate solution) / 10 (VIII)

[0137] An adsorption isotherm was created using Freundlich's adsorption isotherm, with the horizontal axis representing the residual iodine concentration and the vertical axis representing the amount of iodine adsorbed per 1 g of carbonaceous material, and the amount of iodine adsorbed (mg / g) per 1 g of carbonaceous material at a residual iodine concentration of 2.5 g / L was calculated. The amount of iodine adsorbed was taken as the iodine adsorption performance.

[0138] (7) pH The pH of the aqueous suspension was measured using a carbonaceous material. Specifically, in accordance with JIS K 1474 (2014), a carbonaceous material having a particle size of less than 150 μm was powdered, and a carbonaceous material having a particle size of 150 μm or more was granulated. Then, 1.0 g of the powdered carbonaceous material was weighed out in dry mass equivalent, and 3.0 g of the granular carbonaceous material was weighed out in dry mass equivalent. The weighed carbonaceous material was then added to a 100 mL tall beaker, and 100 mL of distilled water was further added to obtain a mixed solution. The obtained mixed solution was gently boiled for 5 minutes using a hot plate (Ceramic Hot Plate CHP-400DN (product name) manufactured by AS ONE Corporation). The mixed solution was then allowed to cool to room temperature, and distilled water was added so that the volume of the mixed solution became 100 mL, followed by stirring to obtain a suspension. The pH of the resulting suspension was measured using a pH meter (Horiba, Ltd., tabletop pH meter F-51 (trade name)). (8) Packing density Using a carbonaceous material, the packing density (g / mL) measured by a tapping method was calculated. Specifically, first, the carbonaceous material was pulverized so that the 50% particle diameter (D50) of the volume-based cumulative distribution was approximately 9.0 μm or more and 11.0 μm or less, and dried for 3 hours in a constant temperature dryer (Yamato Scientific Co., Ltd., DVS402 (trade name)). Thereafter, the material was allowed to cool to room temperature in a desiccator using silica gel as a desiccant, and a carbonaceous material after cooling was obtained.

[0139] 5.0 g of the carbonaceous material after cooling was weighed and divided into roughly three equal parts, and a portion (about ⅓ of the amount) of the carbonaceous material was placed in a 150 mL measuring cylinder (inner diameter: 31 mm, (Tsutsui Scientific Instruments Co., Ltd.)). A rubber stopper was fitted to the measuring cylinder, and it was set in an automatic tapping device (Tsutsui Scientific Instruments Co., Ltd., powder reduction measuring instrument TPM-3A type (trade name)), and tapping was performed for 1 minute with a shaking width of 45 mm and a shaking frequency of 35 to 36 times per minute. After tapping was completed, another portion (about ⅓ of the amount) of the carbonaceous material that had been previously divided into three equal parts was further added to the measuring cylinder, and a rubber stopper was fitted, and tapping was performed for 1 minute under the same conditions as above. Thereafter, the final portion (about ⅓ of the amount) of the carbonaceous material that had previously been divided into three equal parts was further added to the measuring cylinder, and a rubber stopper was fitted, and tapping was performed for 30 minutes under the same conditions as above.

[0140] After tapping, the rubber stopper was removed, the top surface of the sample in the measuring cylinder was flattened with a spatula or the like, and the sample volume (mL) was visually measured from the graduations on the measuring cylinder. Using the measured sample volume, the packing density measured by the tapping method was calculated according to the following formula (IX): Packing density (g / mL) = Mass (g) of carbonaceous material / Measured sample volume (mL) (IX)

[0141] (9) Removal rate of palladium (II) complex The adsorption performance for divalent palladium (palladium (II)) complex was measured using a carbonaceous material. Specifically, first, palladium (II) acetate (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was dissolved in toluene to prepare a palladium solution having a palladium concentration of 50 ppm (hereinafter also simply referred to as "palladium (II) solution for adsorption performance measurement"). 25 mL of the palladium solution was placed in a 100 mL Erlenmeyer flask with a stopper, and 0.5 g of carbonaceous material was added. Thereafter, the mixture was shaken for 1 hour using a constant temperature shaking bath (Taitec Co., Ltd. Cool Bath Shaker ML-10F (trade name)) at 25 ° C. to obtain a mixed solution. Thereafter, the mixed solution was filtered using a membrane filter (Advantec Toyo Co., Ltd. DISMIC (registered trademark) 25HP (trade name)) to obtain a filtrate.

[0142] Using a glass cell with an optical path length of 1 mm and an ultraviolet-visible spectrophotometer (double-beam spectrophotometer U-2910 (trade name) manufactured by Hitachi High-Technologies Corporation), the absorbance at a wavelength of 393 nm was measured for each of the palladium (II) solution for adsorption performance measurement and the filtrate obtained above. Using these absorbances and a calibration curve prepared in advance, the residual concentration (ppm) of each palladium (II) complex in the palladium (II) solution for adsorption performance measurement and the filtrate obtained above was calculated. The calibration curve was prepared as follows. Specifically, a palladium solution containing a palladium (II) complex at a concentration of 50 ppm was diluted 5 times, 50 times, and 100 times with toluene to prepare solutions. The absorbance at a wavelength of 393 nm was then measured using these solutions in the same manner as in the measurement method described above, and a calibration curve was prepared based on the measurement results.

[0143] Next, the resulting residual concentration (ppm) of the palladium (II) complex was used to calculate the removal rate (%) of the palladium (II) complex according to the following formula (X). The removal rate of the palladium (II) complex was defined as the adsorption performance of the carbonaceous material for the palladium (II) complex. Removal rate (%) of palladium (II) complex = residual concentration (ppm) of palladium (II) complex in the filtrate / residual concentration (ppm) of palladium (II) complex in the palladium (II) solution for measuring adsorption performance × 100 (X).

[0144] (10) Removal Rate of Palladium (0) Complex Using a carbonaceous material, the adsorption performance for zero-valent palladium (palladium (0)) complex was measured. Specifically, first, bis(dibenzylideneacetone)palladium (0) (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) was dissolved in toluene to prepare a palladium solution having a palladium concentration of 50 ppm (hereinafter also simply referred to as "palladium (0) solution for adsorption performance measurement"). 25 mL of the palladium solution was placed in a 100 mL Erlenmeyer flask with a stopper, and 0.5 g of carbonaceous material was added. Thereafter, the mixture was shaken for 1 hour using a constant temperature shaking bath (Taitec Co., Ltd. Cool Bath Shaker ML-10F (trade name)) at 25 ° C. to obtain a mixed solution. Thereafter, the mixed solution was filtered using a membrane filter (Advantec Toyo Co., Ltd. DISMIC (registered trademark) 25HP (trade name)) to obtain a filtrate.

[0145] Using a glass cell with an optical path length of 1 mm and an ultraviolet-visible spectrophotometer (double-beam spectrophotometer U-2910 (trade name) manufactured by Hitachi High-Technologies Corporation), the absorbance at a wavelength of 523 nm was measured for each of the palladium(0) solution for adsorption performance measurement and the filtrate obtained above. Using these absorbances and a calibration curve prepared in advance, the remaining concentrations (ppm) of the palladium(0) complex in each of the palladium(0) solution for adsorption performance measurement and the filtrate obtained above were calculated. The calibration curve was prepared as follows. That is, a palladium solution containing a palladium(0) complex at a concentration of 50 ppm was diluted 5 times, 50 times, and 100 times with toluene to prepare solutions. Thereafter, the absorbance at a wavelength of 523 nm was measured using these solutions in the same manner as in the measurement method described above, and a calibration curve was prepared based on the measurement results.

[0146] Next, the resulting residual concentration (ppm) of the palladium(0) complex was used to calculate the removal rate (%) of the palladium(0) complex according to the following formula (XI). The removal rate of the palladium(0) complex was defined as the adsorption performance of the carbonaceous material for the palladium(0) complex. Removal rate (%) of palladium(0) complex = residual concentration (ppm) of palladium(0) complex in the filtrate / residual concentration (ppm) of palladium(0) complex in the palladium(0) solution for adsorption performance measurement × 100 (XI).

[0147] Example 1 (Carbonization step) Wood flour produced in Japan and Malaysia was carbonized at a temperature of 550° C. for approximately 8 hours to obtain a carbonized product.

[0148] (Activation Step) The obtained carbonized material was placed in a rotary kiln with a volume of 1 m as shown in Figs. 1 and 2, which was heated to 850°C and had a stirring blade installed in the furnace. 3 Thereafter, while rotating the kiln at a rotation speed of 3.0 rpm, gas (water vapor 50.0 vol%, oxygen 10.0 vol%, nitrogen 35.0 vol%, and carbon dioxide 5.0 vol%) was introduced into the kiln, and activation treatment was carried out for 60 minutes to obtain an activated product.

[0149] In the rotary kiln used, six stirring blades were installed at 60° intervals around the central axis of the tubular body. The height of the stirring blades was 15% to 25% of the inner radius of the tubular body, and the thickness of the stirring blades was 40% to 80% of the thickness of the tubular body.

[0150] (Acid washing step and drying step, etc.) The obtained activated material was washed with dilute hydrochloric acid, then thoroughly washed with water to remove residual hydrochloric acid, and dried to obtain a dried material. Thereafter, the obtained dried material was pulverized to obtain a pulverized carbonaceous material 1, which is activated carbon.

[0151] Example 2 A pulverized carbonaceous material 2, which was activated carbon, was obtained in the same manner as in Example 1, except that the activation treatment was carried out for 80 minutes in the activation step.

[0152] [Example 3] An activated material was obtained in the same manner as in Example 1. Thereafter, the obtained activated material was dried and pulverized in the same manner as in Example 1, except that washing was not performed, to obtain a pulverized carbonaceous material 3, which is activated carbon.

[0153] Example 4 A pulverized carbonaceous material 4, which was activated carbon, was obtained in the same manner as in Example 1, except that the activation treatment was carried out for 90 minutes in the activation step.

[0154] Comparative Example 1 (Carbonization Step) Coconut shells from the Philippines were carbonized at a temperature of 550° C. for approximately 8 hours to obtain a carbonized product.

[0155] (Activation Step) The obtained carbonized material was placed in a rotary kiln with a volume of 1 m as shown in Figs. 1 and 2, which had a furnace heated to 900°C and had a stirring blade installed inside. 3 Thereafter, while rotating the kiln at a rotation speed of 3.0 rpm, gas (water vapor 40.0 vol%, oxygen 5.0 vol%, nitrogen 50.0 vol%, and carbon dioxide 5.0 vol%) was introduced into the kiln, and activation treatment was carried out for 250 minutes to obtain an activated product.

[0156] In the rotary kiln used, six stirring blades were installed at 60° intervals around the central axis of the tubular body. The height of the stirring blades was 15% to 25% of the inner radius of the tubular body, and the thickness of the stirring blades was 40% to 80% of the thickness of the tubular body.

[0157] (Acid Washing Step, Drying Step, etc.) The obtained activated material was subjected to acid washing, drying, and pulverization in the same manner as in Example 1, thereby obtaining a pulverized carbonaceous material 5 that was activated carbon.

[0158] Comparative Example 2 A pulverized carbonaceous material 6, which was activated carbon, was obtained in the same manner as in Comparative Example 1, except that the activation treatment was carried out for 130 minutes in the activation step.

[0159] Comparative Example 3 An activated material was obtained in the same manner as in Comparative Example 2. Thereafter, the obtained activated material was dried and pulverized in the same manner as in Example 1, except that washing was not performed, to obtain pulverized carbonaceous material 7, which is activated carbon.

[0160] Comparative Example 4 An activated product was obtained in the same manner as in Comparative Example 2. The activated product was then washed with dilute hydrochloric acid and then with dilute nitric acid. The product was then thoroughly washed with water to remove residual nitric acid, and dried to obtain a dried product. The dried product was then pulverized to obtain a pulverized carbonaceous material 8, which is activated carbon.

[0161]

[0162] The carbonaceous material of the present embodiment can be suitably used for various applications such as removing, adsorbing, concentrating, and recovering various palladium complexes such as palladium catalysts.

[0163] This application is based on a Japanese patent application (Patent Application No. 2023-201657) filed on November 29, 2023, the contents of which are incorporated herein by reference.

[0164] A, B, C, D, E, F... agitating blades, 1... pipe body, 2... flow direction of active gas, 3... rotation direction of pipe body, 4... falling direction of carbonized material, 5... carbonized material.

Claims

1. A carbonaceous material having a mesopore ratio of 6.4% or more and 50.0% or less, a reactive black pentavalent value of 1.0 g / L or more and 8.0 g / L or less, and an iodine adsorption amount of 1,000 mg / g or more and 1,600 mg / g or less.

2. The mesopore volume calculated from the N2 adsorption isotherm at -196°C using the BJH method is 0.16 cm 3 / g or more 0.60cm 3 The carbonaceous material of claim 1, wherein the carbonaceous material has a molecular weight of 1:1 or less.

3. The specific surface area calculated by the BET method from the N2 adsorption isotherm at -196°C is 950 m 2 / g or more 1,700m 2 The carbonaceous material of claim 1, wherein the carbonaceous material has a molecular weight of 1:1 or less.

4. The specific surface area calculated by the BJH method from the N2 adsorption isotherm at -196°C is 23 m 2 / g or more 500m 2 / g or less.

5. The carbonaceous material according to claim 1, having a pH of 4.5 or more and 9.5 or less.

6. The carbonaceous material according to claim 1, having a packing density measured by a tapping method of 0.20 g / mL or more and 0.55 g / mL or less.

7. The carbonaceous material according to any one of claims 1 to 6, which is used for adsorbing a zero-valent palladium complex and / or a divalent palladium complex in an organic solvent.

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

9. The method according to claim 8, further comprising a washing step of washing the activation product.

10. The method according to claim 8, wherein the raw material is at least one selected from the group consisting of coconut shells and wood flour.

11. A method for adsorbing a palladium complex, comprising an adsorption step of adsorbing a palladium complex onto the carbonaceous material according to any one of claims 1 to 6.

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