Carbonaceous material and method for producing the same, fluorine-containing organic compound removing material, water purification filter and water purifier

Abstract

One aspect of the present invention relates to a carbonaceous material having a benzene adsorption capacity of 30 to 60%, a vitamin B12 adsorption capacity of more than 50.0 mg / g, and a mesopore volume calculated from a nitrogen adsorption isotherm by a BJH method of 0.13 to 0.30 cm <supgt;3< / supgt; / g。

Description

Technical Field

[0001] The present invention relates to a carbonaceous material and also to a method for producing the carbonaceous material, and a fluorine-containing organic compound removing material, a water purification filter and a water purifier using the carbonaceous material. Background Art

[0002] In recent years, there has been an increasing concern about the safety and hygiene of tap water quality, and there is a demand for the removal of various harmful substances.

[0003] Since fluorinated organic compounds have unique properties that other substances cannot achieve (excellent heat resistance and chemical resistance, can be used under harsh conditions, no light absorption, etc.), they are used in various applications such as surfactants, emulsifiers, waterproofing agents, fire extinguishers, waxes, carpet cleaners, coating agents, etc. Recently, their use as functional materials such as surface treatment agents for semiconductors and fuel cell components is increasing.

[0004] However, since a few years ago, researchers, mainly in the United States and Canada, have reported that some fluorinated organic compounds are accumulating in environmental water and wildlife. Perfluorooctanoic acid (PFOA: C 7 F 15 Perfluoroalkyl carboxylic acids represented by perfluorooctane sulfonic acid (PFOS: C 8 F 17 SO 3 H). Subsequently, researchers from Europe and Japan also participated in environmental analysis studies, and the results confirmed that these compounds exist in the environment worldwide, including Japan. In response to this situation, efforts have been made to reduce the environmental risks of fluorinated organic compounds (perfluoroalkyl compounds and polyfluoroalkyl compounds; sometimes referred to as "PFAS" below).

[0005] For example, a method has been proposed in which activated carbon containing 90% or more of the particles passing through a 75 μm filter is brought into contact with water to be treated containing a fluorinated surfactant to remove the fluorinated surfactant from the water to be treated (Patent Document 1).

[0006] As shown in the technology proposed in Patent Document 1, there is a technology for removing fluorinated organic compounds from water using activated carbon. However, the technology described in Patent Document 1 is mainly used in batch applications (treatment and purification of factory wastewater). The technology proposed so far is a method for removing PFAS from raw water (river water, etc.) in such batch applications and water purification plants, and currently, there has not been much progress in research on methods for removing fluorinated organic compounds using water purifiers, etc.

[0007] The water used for treatment in water treatment plants and water purifiers is different (raw water and tap water), and the treatment time for the water used for treatment is also very different. Therefore, the PFAS removal method used in water treatment plants cannot be directly applied to, for example, household water purifiers.

[0008] Therefore, a main object of the present invention is to provide a carbonaceous material having high PFAS (PFOS, PFOA, etc.) removal performance that can be used also in water purifier applications.

[0009] Prior art literature

[0010] Patent Literature

[0011] Patent Document 1: Japanese Patent Publication No. 2010-158662 Summary of the invention

[0012] The present inventors have conducted intensive studies to solve the above-mentioned problems. As a result, they have found that the above-mentioned problems can be solved by a carbonaceous material having the following structure. Based on this finding, the present inventors have further conducted studies and have completed the present invention.

[0013] That is, the carbonaceous material according to one aspect of the present invention has a benzene adsorption of 30 to 60%, a vitamin B12 adsorption of more than 50.0 mg / g, and a mesopore volume calculated by the BJH method from the nitrogen adsorption isotherm of 0.13 to 0.30 cm 3 / g.

[0014] Another aspect of the present invention is a method for producing carbonaceous materials using a fluidized bed furnace, wherein, in addition to introducing fluidizing gas from the furnace bed, an oxygen-containing gas is also introduced into the fluidized bed furnace so that the oxygen concentration in the combined gas of the fluidizing gas and the oxygen-containing gas becomes 0.004 to 1% by volume.

[0015] A water purification filter according to another aspect of the present invention comprises: the carbonaceous material as described above; and a fibrous binder, wherein the CSF value of the fibrous binder is 10 to 150 mL, and the fibrous binder is contained in an amount of 4 to 10 parts by mass per 100 parts by mass of the carbonaceous material. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 This is a schematic diagram for explaining a method for producing a carbonaceous material using a fluidized bed furnace according to one embodiment of the present invention.

[0017] Figure 2 This is a schematic diagram for explaining a method for producing a carbonaceous material using a fluidized bed furnace according to one embodiment of the present invention.

[0018] Figure 3It is a graph showing the relationship between the removal rate of PFOS and PFOA and the bed volume (Bed Volume) in Examples and Comparative Examples of the present invention. DETAILED DESCRIPTION

[0019] Hereinafter, embodiments of the present invention will be described in detail, but the present invention is not limited to these embodiments.

[0020] [Carbonaceous materials]

[0021] The carbonaceous material according to one embodiment of the present invention has a benzene adsorption capacity of 30 to 60%, a vitamin B12 adsorption capacity of more than 50.0 mg / g, and a mesopore volume calculated by the BJH method from the nitrogen adsorption isotherm of 0.13 to 0.30 cm 3 / g.

[0022] According to the above configuration, it is possible to provide a carbonaceous material having high PFAS (PFOS, PFOA, etc.) removal performance that can be used also in water purifier applications.

[0023] (Benzene adsorption)

[0024] The amount of benzene adsorption is an index showing the degree of progress of activation of the carbonaceous material. The carbonaceous material according to the present embodiment is suitable for adsorbing PFAS because the amount of benzene adsorption is in the range of 30 to 60%.

[0025] From the perspective of having excellent PFAS adsorption performance, the benzene adsorption amount of the carbonaceous material is in the range of 30 to 60%, with the upper limit preferably being below 58%, more preferably below 56%, and further preferably below 55%, and the lower limit is preferably above 40%, more preferably above 42%, and further preferably above 44%.

[0026] The amount of benzene adsorption of the carbonaceous material can be measured by the method described in [Measurement of Benzene Adsorption] described later.

[0027] (Vitamin B12 adsorption)

[0028] Vitamin B12 (cyanocobalamin) has a large molecular weight of about 1355, and the amount of vitamin B12 adsorbed is an indicator of the adsorption characteristics of substances with large molecular sizes. The carbonaceous material involved in this embodiment has a vitamin B12 adsorption amount exceeding 50 mg / g, making it a carbonaceous material suitable for adsorbing PFAS.

[0029] From the perspective of achieving excellent PFAS adsorption performance, the vitamin B12 adsorption of the carbonaceous material exceeds 50 mg / g, preferably 60 mg / g or more, more preferably 70 mg / g or more, and further preferably 80 mg / g or more. The upper limit of the vitamin B12 adsorption is not particularly limited, but from the perspective of the balance with other physical properties such as benzene adsorption, it is generally preferably 500 mg / g or less, more preferably 460 mg / g or less, and further preferably 420 mg / g or less.

[0030] The amount of vitamin B12 adsorbed by the carbonaceous material can be measured by the method described in [Measurement of Vitamin B12 Adsorption Amount] described later.

[0031] (Mesopore volume)

[0032] The pores of carbonaceous materials can be classified into micropores (diameter less than 2 nm), mesopores (diameter 2 to 50 nm) and macropores (diameter greater than 50 nm) according to their diameters (the IUPAC classification standard is indicated in brackets). Mesopores are larger than micropores, and the volume of mesopores can be mainly used as an indicator of the adsorption characteristics of substances with large molecular sizes. The mesopore volume of the carbonaceous material involved in this embodiment is between 0.130 and 0.30 cm 3 / g range, thereby becoming a carbonaceous material more suitable for adsorbing PFAS.

[0033] From the perspective of achieving excellent PFAS adsorption performance, the mesopore volume of carbonaceous materials is between 0.130 and 0.300 cm 3 / g, the lower limit is preferably 0.140cm 3 / g or more, more preferably 0.145cm 3 / g or more. In addition, the upper limit is preferably 0.280cm 3 / g or less, more preferably 0.250cm 3 / g or less.

[0034] The mesopore volume of the carbonaceous material can be calculated from the nitrogen adsorption isotherm using the BJH (Barrett-Joyner-Halenda) method. The determination of the nitrogen adsorption isotherm and the calculation of the mesopore volume can be implemented by the methods described in [Determination of nitrogen adsorption isotherm] and [Determination of mesopore volume by BJH method] described later.

[0035] The above attempts to explain the technical significance of the benzene adsorption, vitamin B12 adsorption and mesopore volume in the present embodiment, but the relationship between the structure of the carbonaceous material (adsorption medium) and the adsorption characteristics of the adsorbate is complex, and sometimes the benzene adsorption, vitamin B12 adsorption and mesopore volume are not directly correlated with the adsorption characteristics of the adsorbate independently. It is believed that in order to achieve a carbonaceous material that can effectively remove PFAS, it is important to balance these benzene adsorption, vitamin B12 adsorption and mesopore volume. As described later, in the present embodiment, a carbonaceous material having the above characteristics is successfully manufactured by a specific manufacturing method using a fluidized bed furnace.

[0036] As long as the benzene adsorption, vitamin B12 adsorption and mesopore volume of the carbonaceous material of this embodiment are each within the above ranges as described above, there are no particular limitations on other properties. However, in order to more reliably achieve the effects of the present invention, it is considered that the carbonaceous material preferably also has the properties described below.

[0037] (Specific surface area)

[0038] From the viewpoint of achieving a high level of adsorption and removal performance required for a water purifier, the specific surface area of ​​the carbonaceous material is preferably between 1200 and 2000 m 2 The lower limit of the specific surface area is preferably 1300 m 2 / g or above or 1400m 2 / g or more, and the upper limit is preferably 1900m 2 / g or below or 1800m 2 / g or less.

[0039] The specific surface area of ​​the carbonaceous material can be calculated from the nitrogen adsorption isotherm using the BET method. The measurement of the nitrogen adsorption isotherm and the calculation of the specific surface area can be carried out by the methods described in [Measurement of nitrogen adsorption isotherm] and [Measurement of specific surface area] described below.

[0040] (Average pore size)

[0041] From the viewpoint of achieving better PFAS adsorption performance, the average pore diameter of the carbonaceous material is preferably in the range of 1.85 to 1.90 nm. The lower limit of the average pore diameter is preferably 1.86 nm or 1.87 nm, and the upper limit is preferably 1.89 nm or 1.88 nm.

[0042] The average pore diameter of the carbonaceous material can be calculated from the nitrogen adsorption isotherm. The measurement of the nitrogen adsorption isotherm and the calculation of the average pore diameter can be carried out by the methods described in [Measurement of nitrogen adsorption isotherm] and [Measurement of total pore volume and average pore diameter] described below.

[0043] (Conductivity)

[0044] The carbonaceous material involved in the present embodiment preferably has a conductivity in the range of 3 to 9 S / cm as measured by powder resistance under a load of 12 kN. If the conductivity is within this range, in detail, if the carbonaceous material has a structure with a conductivity within the range, the high level of adsorption and removal performance required for the water purifier can be achieved. The upper limit of the conductivity is preferably 8.7 S / cm or less, more preferably 8.3 S / cm or less, and further preferably 8 S / cm or less, and the lower limit is preferably 5.3 S / cm or more, more preferably 5.6 S / cm or more, and further preferably 6 S / cm or more.

[0045] The electrical conductivity of the carbonaceous material can be measured by the method described in [Measurement of Electrical Conductivity] described later.

[0046] The shape of the carbonaceous material is not particularly limited, and can be any shape such as a particle, a fiber (filament, a woven (cloth) shape, a felt shape), etc., and can be appropriately selected according to the specific use mode, but due to the high adsorption performance per unit volume, it is preferably a particle. In the case of a particle-shaped carbonaceous material, its size is not particularly limited, and the particle size can be appropriately adjusted according to the specific use mode.

[0047] The raw material (carbonaceous precursor) of the carbonaceous material is not particularly limited. For example, plant-based carbonaceous precursors (such as wood, wood shavings, charcoal, fruit shells such as coconut shells and walnut shells, fruit seeds, byproducts of pulp manufacturing, lignin, waste molasses and other plant-based materials); mineral-based carbonaceous precursors (such as peat, lignite (sub-charcoal), wood coal (brown coal), bituminous coal, anthracite, coke, coal tar, coal tar, petroleum distillation residues, petroleum asphalt and other mineral-based materials); synthetic resin-based carbonaceous precursors (such as phenolic resins, polyvinylidene chloride, acrylic resins and other synthetic resin-based materials); natural fiber-based carbonaceous precursors (such as natural fibers such as cellulose, natural fiber-based materials such as regenerated fibers such as rayon), etc. Among them, plant-based carbonaceous precursors are easy to use as carbonaceous materials with excellent adsorption properties for removal targets specified in the Household Products Quality Labeling Act, and are therefore preferred. Therefore, in a preferred embodiment, the carbonaceous material is derived from a plant-based carbonaceous precursor. From the viewpoint of realizing a carbonaceous material that can more effectively remove PFAS, coconut shell is preferably used as a raw material. Therefore, in a particularly preferred embodiment, coconut shell is used as a plant-based carbonaceous precursor.

[0048] The carbonaceous material involved in this embodiment is suitable for adsorbing PFAS, and has excellent effects in water purifier applications. Therefore, the carbonaceous material of this embodiment can be suitable for use as a carbonaceous material for water purification (carbonaceous material for water purification), and is more suitable for use as a carbonaceous material for purifying tap water (carbonaceous material for tap water purification).

[0049] In particular, the carbonaceous material of the present embodiment has a fluorine-containing organic compound removal performance of 12,000 or more in terms of bed volume (Bed Volume) obtained under the following measurement conditions.

[0050] (Measurement conditions)

[0051] Water (containing 1.2 ppm TOC) adjusted to 50±10 ppt PFOA and 50±10 ppt PFOS was used as test water at 7.2 mL / min and space velocity (SV=560 hr) -1 Under the condition of , water is passed through a stainless steel column with a diameter of 6.2 mm, a height of 25.4 mm, and an internal volume of 0.77 mL filled with carbonaceous material in an upward flow manner, and the water flow from the start of water flow to the breakthrough point (breakthrough point) obtained when the removal rate is less than 80% is taken as the breakthrough point, that is, the bed volume (bedVolume) is used as the removal performance. It is believed that the excellent removal effect can be obtained more reliably according to this.

[0052] Since the carbonaceous material of this embodiment can effectively adsorb fluorine-containing organic compounds, it is suitable for use as a fluorine-containing organic compound removing material. Therefore, the present invention also includes a fluorine-containing organic compound removing material formed of the above-mentioned carbonaceous material.

[0053] [Method for producing carbonaceous material]

[0054] The carbonaceous material according to one embodiment of the present invention is manufactured by activating the above-mentioned carbonaceous precursor. In addition, when carbonization is required before activation, it is usually isolated from oxygen or air and carbonized at, for example, 400 to 800° C. (preferably 500 to 800° C., more preferably 550 to 750° C.). At this time, the raw carbon obtained by carbonization of the carbonaceous precursor is activated to manufacture the carbonaceous material.

[0055] When achieving a carbonaceous material with a benzene adsorption amount, a vitamin B12 adsorption amount, and a mesopore volume (further, the specific surface area, average pore diameter, conductivity, and other characteristics that are arbitrarily satisfied as needed) within a specific range, an activation method is important. The method for producing a carbonaceous material according to the present embodiment is characterized in that (hereinafter, also referred to as "the production method of the present embodiment") a fluidized bed furnace (fluidized activation furnace) is used as an activation furnace, and in addition to the fluidizing gas introduced from the furnace bed, an oxygen-containing gas is introduced into the fluidized bed furnace. Accordingly, a carbonaceous material with a benzene adsorption amount of 40 to 60% and a vitamin B12 adsorption amount exceeding 50 mg / g can be achieved, which is difficult to achieve in the conventional method of using a rotary kiln as an activation furnace and the conventional method of only introducing a fluidizing gas from the furnace bed into the fluidized bed furnace.

[0056] The fluidizing gas is not particularly limited as long as it has the function of fluidizing and activating the raw carbon, and any conventionally known substance can be used. For example, as the fluidizing gas, a gas containing water vapor and / or carbon dioxide can be cited. In industry, since water vapor and carbon dioxide are moderately contained, it is preferred to use a combustion gas of hydrocarbons (for example, light gases such as methane, propane, and butane; liquid fuels such as light oil, kerosene, and heavy oil).

[0057] From the viewpoint of effectively activating the raw carbon, the water vapor concentration in the fluidizing gas is preferably 10 to 40% by volume. The upper limit is more preferably 35% by volume or less or 30% by volume or less, and the lower limit is more preferably 12% by volume or more, 14% by volume or more, or 15% by volume or more. In addition, when the fluidizing gas contains carbon dioxide, the carbon dioxide concentration in the fluidizing gas is preferably 15% by volume or less. The upper limit is more preferably 14% by volume or less or 13% by volume or less, and the lower limit is more preferably 8% by volume or more, 9% by volume or more, or 10% by volume or more.

[0058] In the manufacturing method of the present embodiment, in addition to the fluidizing gas introduced from the furnace bed, an oxygen-containing gas is also introduced into the fluidized bed furnace. The oxygen-containing gas is introduced into the fluidized bed furnace in such a way that the oxygen concentration in the combined gas of the fluidizing gas and the oxygen-containing gas becomes 0.004 to 1% by volume. From the perspective of obtaining a carbonaceous material that can further effectively remove PFAS, the oxygen concentration in the combined gas of the fluidizing gas and the oxygen-containing gas is preferably 0.005% by volume or more, 0.01% by volume or more, 0.02% by volume or more, 0.03% by volume or more, 0.04% by volume or more, or 0.05% by volume or more. The upper limit of the oxygen concentration is preferably 0.95% by volume or less, 0.9% by volume or less, 0.85% by volume or less, or 0.8% by volume or less. In the present embodiment, the oxygen concentration in the combined gas of the fluidizing gas and the oxygen-containing gas is a charge-converted concentration calculated based on the composition and introduction amount of the fluidizing gas, and the composition and introduction amount of the oxygen-containing gas.

[0059] The oxygen-containing gas is not particularly limited as long as it contains oxygen, for example, air and a gas diluted with other gases (such as inert gases such as nitrogen) can be used. The oxygen concentration in the oxygen-containing gas is not particularly limited as long as the oxygen concentration in the combined gas of the fluidizing gas and the oxygen-containing gas is in the range of 0.004 to 1% by volume, but is preferably 20% by volume or less, more preferably 15% by volume or less, 10% by volume or less, 8% by volume or less, 6% by volume or less, 5% by volume or less, 4% by volume or less, 3% by volume or less or 2% by volume or less. The lower limit of the oxygen concentration in the oxygen-containing gas can usually be set to 0.1% by volume or more, 0.2% by volume or more, etc. In addition, the fluidizing gas introduced from the furnace bed can contain oxygen, but when using combustion gas as the fluidizing gas, it is generally difficult to control the trace oxygen concentration in the combustion gas, so it is preferred to control the oxygen concentration by oxygen derived from the oxygen-containing gas.

[0060] Hereinafter, the manufacturing method of this embodiment will be described with reference to the drawings.

[0061] Figure 1 A schematic diagram showing a fluidized bed furnace (fluidized activation furnace) 100 used in the manufacturing method of the present embodiment. In the following description, each reference numeral represents: 1 fluidizing gas inlet, 2 oxygen-containing gas inlet, 3 gas outlet, 4 gas dispersion layer, 5 raw charcoal, 6 raw charcoal (during fluidization activation), 7 fluidizing gas, 8 oxygen-containing gas, 9 exhaust gas, 10 gas dispersion section, 20 fluidized bed section, 100 fluidized bed furnace (fluidized activation furnace).

[0062] The fluidized bed furnace 100 includes a fluidizing gas inlet 1, an oxygen-containing gas inlet 2, a gas outlet 3, and a gas dispersion layer 4. The fluidizing gas inlet 1 is usually arranged at the furnace bed. The fluidizing gas (not shown) introduced into the fluidized bed furnace 100 passes through the gas dispersion layer 4 and contacts the raw coal 5 to fluidize and activate the raw coal. Then, the fluidizing gas is discharged to the outside of the furnace from the gas outlet 3 usually arranged at the furnace top. Figure 1 In FIG. 5 , the main flow direction of the fluidizing gas (ie, the flow direction from the furnace bed to the furnace top) is represented as direction Z.

[0063] The gas dispersion layer 4 is not particularly limited as long as it has the function of dispersing the flow of the fluidizing gas introduced from the fluidizing gas inlet 1 and making the fluidizing gas and the raw coal 5 contact uniformly, and a conventionally known gas dispersion layer can be used. For example, when a perforated plate is used to disperse the fluidizing gas, the buffer area from the furnace bed to the perforated plate is included and is called the gas dispersion layer 4. Figure 1As shown in FIG. 1 , the gas distribution layer 4 is arranged on the upstream side in the fluidized bed furnace when viewed from the main flow direction Z of the fluidizing gas. In the present embodiment, the region formed by the gas distribution layer 4 is referred to as a gas distribution section 10. Therefore, when viewed from the main flow direction Z of the fluidizing gas, the fluidized bed furnace 100 includes the gas distribution section 10 on the upstream side in the fluidized bed furnace.

[0064] The fluidized bed furnace 100 further includes a fluidized bed section 20 on the downstream side in the fluidized bed furnace when viewed from the main flow direction Z of the fluidizing gas. In the fluidized bed section 20 , the raw coal 5 contacts the fluidizing gas, and fluidization activation of the raw coal 5 is performed.

[0065] As described above, the manufacturing method of the present embodiment is characterized in that in addition to introducing the fluidizing gas from the furnace bed, an oxygen-containing gas is also introduced into the fluidized bed furnace. Furthermore, when realizing a carbonaceous material having a benzene adsorption amount and a vitamin B12 adsorption amount within a specific range, the position of introducing the oxygen-containing gas is important. That is, when the upstream end position of the gas dispersion section in the main flow direction Z of the fluidizing gas is set to 0 (m), the downstream end position is set to t1 (m) (t1>0), and the oxygen-containing gas introduction position is set to t2 (m), it is preferred to satisfy the relationship of 0.5t1≤t2. When 0.5t1>t2, it is difficult to realize the carbonaceous material involved in the present embodiment having a benzene adsorption amount and a vitamin B12 adsorption amount within a specific range. Preferably, 0.7t1≤t2, more preferably 0.8t1≤t2, 0,9t1≤t2 or t1≤t2, particularly preferably t1<t2, 1.2t1≤t2, 1.4t1≤t2 or 1.5t1≤t2. The upper limit of t2 is not particularly limited as long as the oxygen-containing gas can contact the raw coal in the fluidized activation process, and can be any position up to the furnace top, but preferably, when the height (thickness) of the fluidized bed 20 is T (m) (i.e., T = (height of the furnace top - t1)) when viewed from the direction Z, t2 ≤ 0.8T, t2 ≤ 0.7T, t2 ≤ 0.6T or t2 ≤ 0.5T. In addition, when the oxygen-containing gas inlet 2 has a width (thickness) when viewed from the direction Z, the oxygen-containing gas introduction position t2 refers to the center position of its width (thickness).

[0066] Figure 2 It means use Figure 1 Schematic diagram of the fluidized bed furnace fluidizing and activating raw carbon. Figure 2 In, use Figure 1 Components and parts denoted by the same reference numerals represent the same Figure 1 Same components and parts.

[0067] exist Figure 2In the fluidized bed furnace 100, a fluidizing gas 7 is introduced from the furnace bed into the fluidized bed furnace 100, and an oxygen-containing gas 8 is introduced from the furnace side into the fluidized bed furnace 100. The fluidizing gas 7 passes through the gas dispersion section 10 formed by the gas dispersion layer 4, and contacts the raw charcoal in the fluidized bed section 20 to provide fluidization activation of the raw charcoal. In addition, the oxygen-containing gas 8 (more specifically, the oxygen in the gas) contacts the raw charcoal 6 during fluidization activation to provide local activation of the raw charcoal. It can be inferred that by locally activating the raw charcoal with such an oxygen-containing gas, mesopores can be locally developed while maintaining micropores, and as a result, a carbonaceous material having a benzene adsorption amount and a vitamin B12 adsorption amount within a specific range can be advantageously produced.

[0068] The raw carbon activation conditions may adopt conventionally known conditions except for introducing the oxygen-containing gas and the fluidizing gas separately. For example, the activation temperature may be 700 to 1000°C (preferably 800 to 1000°C, more preferably 850 to 950°C), and the activation time may be any time that achieves the desired amount of benzene adsorption (the desired degree of activation progress).

[0069] As described above, in the manufacturing method of the present embodiment, the desired carbonaceous material having a benzene adsorption amount, a vitamin B12 adsorption amount, and a mesopore pore volume within a specific range can be manufactured by the action of the oxygen-containing gas introduced separately from the fluidizing gas. Here, the activation of the raw carbon using water vapor and carbon dioxide in the fluidizing gas is an endothermic reaction, whereas the activation of the raw carbon using oxygen in the oxygen-containing gas is a rapid exothermic reaction. Therefore, in the manufacturing method of the present embodiment in which the oxygen-containing gas is brought into contact with the raw carbon during fluidization activation, the heat supply from the outside required to maintain the activation of the raw carbon can be reduced, which is also extremely advantageous from the perspective of energy balance.

[0070] The fluidizing gas 7 and the oxygen-containing gas 8 are supplied to activate the raw coal and then discharged to the outside of the furnace from the gas outlet ( Figure 2 9) By circulating part or all of the exhaust gas or performing heat exchange, the thermal energy of the exhaust gas can be reused.

[0071] Figure 1 and Figure 2 The fluidized bed furnace is shown with one fluidizing gas inlet 1, one oxygen-containing gas inlet 2, and one gas outlet 3. Figure 1 and Figure 2 It is just a schematic diagram, and the fluidized bed furnace may have multiple fluidizing gas inlets 1, oxygen-containing gas inlets 2, and gas outlets 3. When there are multiple oxygen-containing gas inlets 2, they may be arranged at the same position (height) or at different positions (heights) when viewed from the main flow direction Z of the fluidizing gas.

[0072] When using a plant-based carbonaceous precursor or a mineral-based carbonaceous precursor such as coconut shell containing impurities such as alkali metals, alkaline earth metals and transition metals, the activated carbonaceous material is washed in order to remove ash or chemical reagents. Therefore, in one embodiment, the manufacturing method of the present invention may also include a step of washing the activated carbonaceous material. At this time, an inorganic acid or water is used in the washing, and as the inorganic acid, hydrochloric acid with high washing efficiency is preferred. In the case of washing (pickling) the carbonaceous material with an inorganic acid such as hydrochloric acid, it is preferably washed with water after pickling, etc., for deacidification.

[0073] After washing, the obtained carbonaceous material is dried and, if necessary, pulverized and sieved to obtain a carbonaceous material product.

[0074] [Water purification filter]

[0075] A water purification filter can be produced using a carbonaceous material. A water purification filter according to a preferred embodiment will be described below.

[0076] In a preferred embodiment, a water purification filter includes the carbonaceous material according to the present embodiment described above and a fibrous binder.

[0077] The fibrous binder is not particularly limited as long as it can be shaped by entanglement with the carbonaceous material through fibrillation, and both synthetic and natural products can be widely used. Examples of such fibrous binders include acrylic fibers, polyethylene fibers, polypropylene fibers, polyacrylonitrile fibers, cellulose fibers, nylon fibers, aramid fibers, pulp, etc. The fiber length of the fibrous binder is preferably 4 mm or less.

[0078] The fibrous binder can be used in combination of two or more. It is particularly preferred to use polyacrylonitrile fiber or pulp as the binder. This can further increase the density and strength of the molded body and suppress performance degradation.

[0079] In a preferred embodiment, the water permeability of the fibrous binder is about 10 to 150 mL in terms of CSF value. In the present embodiment, the CSF value is a value measured in accordance with the Canadian Standard Freeness Method of JIS P8121 "Test Method for Water Filterability of Pulp". In addition, the CSF value can be adjusted, for example, by fibrillating the fibrous binder. If the CSF value of the fibrous binder is less than 10 mL, water permeability cannot be obtained, and there is a risk that the strength of the molded body will decrease and the pressure loss will also increase. On the other hand, when the CSF value exceeds 150 mL, the powdered activated carbon cannot be fully retained, the strength of the molded body will decrease, and there is a possibility that the adsorption performance will deteriorate.

[0080] As for the filter for water purification, from the viewpoint of the removal performance and formability of the removal target substance, it is preferred to contain 4 to 10 parts by mass of a fibrous binder relative to 100 parts by mass of carbonaceous material, and more preferably 4.5 to 6 parts by mass of a fibrous binder. Therefore, in a preferred embodiment, the filter for water purification contains the carbonaceous material and the fibrous binder involved in the present embodiment, the CSF value of the fibrous binder is 10 to 150 mL, and 4 to 10 parts by mass of the fibrous binder are contained relative to 100 parts by mass of the carbonaceous material. It should be noted that, in the case where the filter for water purification contains other functional components described later, the "relative to 100 parts by mass of carbonaceous material" in the filter composition can be rewritten as "relative to 100 parts by mass of carbonaceous material and other functional components in total".

[0081] As long as the effect of the present invention is not inhibited, the water purification filter may further include other functional components. As other functional components, lead adsorbents such as titanium silicate or zeolite powders that can adsorb and remove soluble lead, ion exchange resins or chelate resins, or various adsorbents containing silver ions and / or silver compounds to impart antibacterial properties can be cited.

[0082] The water purification filter involved in the present embodiment includes the carbonaceous material involved in the present embodiment, and thus can effectively remove PFAS. The water flow conditions are not particularly limited, and are implemented, for example, at a space velocity (SV) of 300 to 6500 / hr so ​​that the pressure loss does not become extremely large. By plotting the relationship between each removal rate calculated based on the concentration of the removal target substance in the raw water and the permeated water, and the ratio of the amount of water (L) flowing from the start of water flow to the volume (mL) of the water purification filter element (cumulative permeated water volume L / mL), the performance of the water purification filter can be confirmed.

[0083] [Water Purifier]

[0084] A water purifier can be manufactured using the carbonaceous material or the water purification filter. In a preferred embodiment, the water purifier includes the carbonaceous material or the water purification filter according to the present embodiment as described above.

[0085] In a preferred embodiment, the water purifier includes a water purification filter element, which is formed using the carbonaceous material or water purification filter involved in the present embodiment. For example, the carbonaceous material involved in the present embodiment can be filled into a housing to form a water purification filter element, and further, the water purification filter involved in the present embodiment can also be filled into a housing to form a water purification filter element. In addition to the carbonaceous material or water purification filter involved in the present embodiment, the water purification filter element can also be combined to include a known non-woven filter, various adsorbents, mineral additives, ceramic filter materials, hollow fiber membranes, etc.

[0086] As described above, this specification discloses various aspects of technology, and its main technologies are summarized as follows.

[0087] That is, the carbonaceous material according to one aspect of the present invention has a benzene adsorption of 30 to 60%, a vitamin B12 adsorption of more than 50.0 mg / g, and a mesopore volume calculated by the BJH method from the nitrogen adsorption isotherm of 0.13 to 0.30 cm 3 / g.

[0088] According to this configuration, it is possible to provide a carbonaceous material having high PFAS (PFOS, PFOA, etc.) removal performance and usable also in water purifier applications.

[0089] In the carbonaceous material, preferably, the specific surface area calculated from the nitrogen adsorption isotherm by the BET method is 1200 to 2000 m 2 / g. It is considered that this configuration can achieve a high level of adsorption and removal performance required for a water purifier.

[0090] Furthermore, in the carbonaceous material, it is preferred that the average pore diameter calculated from the nitrogen adsorption isotherm is 1.85 to 1.90 nm. It is believed that this can further effectively remove PFAS.

[0091] Furthermore, in the carbonaceous material, it is preferred that the electrical conductivity obtained by powder resistance measurement under a load of 12 kN is 3 to 9 S / cm. It is considered that this can achieve a high level of adsorption and removal performance required for a water purifier.

[0092] In addition, the carbonaceous material is preferably derived from a plant-based carbonaceous precursor. It is believed that this makes it easy to use as a carbonaceous material with excellent adsorption performance for the removal target substances specified in the Household Products Quality Labeling Act. Moreover, the plant-based carbonaceous precursor is preferably coconut shell, which is believed to be able to achieve a carbonaceous material that can further effectively remove PFAS.

[0093] Furthermore, it is preferred that the carbonaceous material has a fluorine-containing organic compound removal performance of 12,000 or more in terms of bed volume (Bed Volume) obtained under the following measurement conditions.

[0094] Measurement conditions: Water (containing 1.2 ppm TOC) adjusted to 50±10 ppt PFOA and 50±10 ppt PFOS concentrations was used as test water at 7.2 mL / min and space velocity (SV) = 560 hr -1Under the conditions of , water was passed through a stainless steel column with a diameter of 6.2 mm, a height of 25.4 mm, and an internal volume of 0.77 mL filled with carbonaceous material in an upward flow manner, and the water flow from the start of water flow to the breakthrough point, i.e., the bed volume, was obtained when the point where the removal rate became less than 80% was taken as the breakthrough point as the removal performance. It is believed that the above-mentioned effect can be obtained more reliably according to this.

[0095] Another aspect of the present invention relates to a method for producing a carbonaceous material using a fluidized bed furnace, wherein, in addition to introducing a fluidizing gas from a furnace bed, an oxygen-containing gas is introduced into the fluidized bed furnace so that the oxygen concentration in the combined gas of the fluidizing gas and the oxygen-containing gas is 0.004 to 1% by volume. With this configuration, an excellent carbonaceous material as described above can be obtained.

[0096] Furthermore, in the production method, it is preferred that the concentration of water vapor in the fluidizing gas introduced from the hearth is 10 to 40% by volume. This is considered to enable the raw carbon to be effectively activated.

[0097] Furthermore, in the production method, it is preferred that the fluidized bed furnace has a gas dispersion section on the upstream side in the fluidized bed furnace when viewed in the main flow direction Z of the fluidizing gas, and when the upstream end position of the gas dispersion section in the direction Z is set to 0 in meters, the downstream end position is set to t1 in meters, and the position for introducing the oxygen-containing gas is set to t2 in meters, the oxygen-containing gas is introduced in a manner that satisfies the relationship of 0, 5t1≤t2. It is believed that the excellent carbonaceous material as described above can be obtained more reliably according to this.

[0098] Another aspect of the present invention relates to a water purification filter comprising: the carbonaceous material as described above; and a fibrous binder, wherein the CSF value of the fibrous binder is 10 to 150 mL, and 4 to 10 parts by mass of the fibrous binder are contained relative to 100 parts by mass of the carbonaceous material. In addition, the present invention also includes: a water purifier comprising the carbonaceous material as described above; a fluorine-containing organic compound removal material comprising the carbonaceous material as described above; and a water purifier comprising the water purification filter.

[0099] Example

[0100] Hereinafter, the present invention will be further specifically described by way of examples, however, the present invention is not limited to these examples.

[0101] <Evaluation method>

[0102] The physical property values ​​in the examples were measured by the methods shown below.

[0103] [Determination of benzene adsorption amount]

[0104] The carbonaceous materials prepared in the examples and comparative examples were dried in a constant temperature dryer at 115°C for 3 hours and then cooled to room temperature in a dryer using silica gel as a desiccant. Next, dry air containing benzene at a concentration of 1 / 10 of the saturated concentration was passed through the carbonaceous material in a constant temperature bath at 20°C. The benzene adsorption amount (mass %) was calculated according to the following formula (1) based on the mass of the carbonaceous material that reached adsorption equilibrium and the mass of the carbonaceous material before adsorption (i.e., the mass of the carbonaceous material after drying and cooling).

[0105] [Formula (1)]

[0106] Benzene adsorption amount (mass %) = [{(mass of sample after benzene adsorption) - (mass of sample before benzene adsorption)} / (mass of sample before benzene adsorption)] × 100

[0107] [Determination of vitamin B12 adsorption]

[0108] The carbonaceous material prepared in the examples and comparative examples was crushed into a volume-based cumulative distribution of the carbonaceous material with a 50% particle size (D50) of about 9 to 11 μm, and dried in a constant temperature dryer at 115°C for 3 hours, and then cooled to room temperature in a dryer using silica gel as a desiccant. In addition, the particle size of the crushed carbonaceous material was measured using a laser diffraction measurement method. That is, the carbonaceous material to be measured was added to ion exchange water together with a surfactant, ultrasonic vibration was applied to prepare a uniform dispersion, and the measurement was performed using Microtrac MT3200 manufactured by Microtrac BEL Co., Ltd. The surfactant used was "Polyoxyethylene (10) octylphenyl ether" manufactured by Fujifilm Wako Pure Chemical Industries, Ltd. The analysis conditions are shown below.

[0109] (Analysis conditions)

[0110] Number of measurements: 1

[0111] Measurement time: 30 seconds

[0112] Distribution Display: Volume

[0113] Particle size classification: Standard Calculation mode: MT3000

[0114] Solvent name: Water

[0115] Upper limit of measurement: 1408μm, Lower limit of measurement: 0.265μm

[0116] Residual component ratio: 0.00

[0117] By composition ratio: 0.00

[0118] Residual component ratio setting: Invalid

[0119] Particle permeability:

[0120] Particle refractive index: 1.81

[0121] Particle shape: non-spherical

[0122] Solvent refractive index: 1.333

[0123] DV value: 0.0100~0.0500

[0124] Transmittance (TR): 0.750~0.920

[0125] Flow rate: 50%

[0126] To about 0.050 g of the obtained carbonaceous material was added vitamin B12 (C 63 H 88 N 14 O 14 PCo: molecular weight 1355.4) aqueous solution 100 mL, and stirred at 25 ° C for 24 hours. Then, the absorbance at 330 nm was measured for the filtrate after filtering the carbonaceous material and the vitamin B12 test water of about 300 ppm used in the adsorption test, and the concentration of vitamin B12 was calculated based on the pre-made calibration curve. Based on the obtained vitamin B12 concentration, the adsorption amount of vitamin B12 per 1 g of carbonaceous material was calculated by the following formula (2).

[0127] [Formula (2)]

[0128] Vitamin B12 adsorption amount (mg / g) = {Vitamin B12 concentration before adsorption (ppm) - Vitamin B12 concentration after adsorption treatment (ppm)} × 0.1 / mass of carbonaceous material (g)

[0129] [Determination of nitrogen adsorption isotherm]

[0130] The carbonaceous material was heated at 300° C. for 3 hours under a nitrogen flow (nitrogen flow rate: 50 mL / min) using BELSORP-mini manufactured by Microchip BEL CORPORATION, and then the nitrogen adsorption / desorption isotherm of the carbonaceous material at 77 K was measured.

[0131] [Measurement of specific surface area]

[0132] The nitrogen adsorption isotherm obtained by the above method was analyzed by a multipoint method using the BET equation, and the specific surface area was calculated from a straight line in the relative pressure region of P / P0=0.01 to 0.1 of the obtained curve.

[0133] [Measurement of total pore volume and average pore diameter]

[0134] The total pore volume was calculated by the Gurvish method from the nitrogen adsorption amount at the relative pressure P / P0=0.99 of the nitrogen adsorption isotherm obtained by the above method. The average pore diameter was calculated based on the total pore volume and the specific surface area obtained by the BET method described above according to the following formula (3).

[0135] [Formula (3)]

[0136] Average pore diameter (nm) = total pore volume (cm 3 / g) / Specific surface area (m 2 / g)×4000

[0137] [Measurement of mesopore volume by BJH method]

[0138] The BJH method was applied to the nitrogen adsorption isotherm obtained by the above method to calculate the pore volume of the mesopores. In addition, when performing the analysis by the BJH method, the reference curve "NGCB-BEL.t" provided by Microchip BEL Co., Ltd. was used.

[0139] [Determination of electrical conductivity]

[0140] The electrical conductivity of the carbonaceous material was measured using a powder resistivity test system (manufactured by Mitsubishi Chemical Analytical Tech Co., Ltd., MCP-PD51). Since the particle size of the test sample has a great influence on the measurement of the electrical conductivity, it was crushed so that the 50% particle size (D50) of the cumulative distribution of the carbonaceous material on a volume basis was about 5 to 8 μm, and the electrical conductivity of the carbonaceous material particles was measured when a load of 12 kN was applied. In addition, the particle size of the crushed carbonaceous material was measured using a laser diffraction measurement method. The measurement procedure and analysis conditions for the particle size of the carbonaceous material are as described above in [Measurement of Vitamin B12 Adsorption].

[0141] <Example 1>

[0142] The particle size of coconut shell charcoal obtained by carbonizing coconut shells produced in the Philippines was adjusted from 30 mesh (0.5 mm) to 60 mesh (0.25 mm). 1 kg of the coconut shell charcoal was put into a fluidized activation furnace heated to 900°C, and a fluidizing gas of 15% by volume of water vapor and 11% by volume of carbon dioxide was introduced from the furnace bed at 50 L / min, and an oxygen-containing gas of 0.5% by volume of oxygen and 99.5% by volume of nitrogen was introduced from the side of the furnace at 5 L / min, and an activation treatment was performed until the benzene adsorption reached about 53.3% by weight (the oxygen concentration in the total gas introduced into the fluidized activation furnace was about 0.045% by volume). The fluidized activation furnace used a furnace with a gas dispersion layer on the upstream side of the furnace when viewed from the main flow direction Z of the fluidized gas. In addition, the introduction position t2 of the oxygen-containing gas in the direction Z and the downstream end t1 of the gas dispersion layer satisfied the relationship t1<t2. That is, the oxygen-containing gas was introduced into the fluidized bed portion of the fluidized activation furnace.

[0143] The activated carbon obtained was washed with dilute hydrochloric acid, and then fully washed with ion exchange water to remove the residual hydrochloric acid, and then dried to obtain a carbonaceous material. Table 1 shows the treatment conditions and the physical properties of the obtained carbonaceous material.

[0144] <Example 2>

[0145] A carbonaceous material was obtained in the same manner as in Example 1, except that the concentration of the oxygen-containing gas introduced during the activation treatment was changed to 1.0% by volume of oxygen and 99.0% by volume of nitrogen, and the activation treatment was performed until the amount of benzene adsorption reached 45.7% by weight. The treatment conditions and physical properties of the obtained carbonaceous material are shown in Table 1.

[0146] <Example 3>

[0147] A carbonaceous material was obtained in the same manner as in Example 1, except that the concentration of the oxygen-containing gas introduced during the activation treatment was changed to 3.0% by volume of oxygen and 97.0% by volume of nitrogen, and the activation treatment was performed until the amount of benzene adsorption reached 52.6% by weight. The treatment conditions and physical properties of the obtained carbonaceous material are shown in Table 1.

[0148] <Comparative Example 1>

[0149] A carbonaceous material was obtained by the same method as in Example 1 except that the activation treatment was performed until the amount of benzene adsorption reached about 34.4% by weight. Table 1 shows the treatment conditions and the physical properties of the obtained carbonaceous material.

[0150] <Comparative Example 2>

[0151] The particle size of coconut shell charcoal obtained by carbonizing coconut shells produced in the Philippines was adjusted from 30 mesh (0.5 mm) to 60 mesh (0.25 mm). 5 g of the coconut shell charcoal was put into a horizontal electric tubular furnace provided with a quartz tube with an inner diameter of 42 mm. Water was bubbled with 0.5% oxygen by volume and 99.5% nitrogen at 1 L / min, thereby introducing water vapor into the furnace and heating it to 900 ° C. The activation treatment was carried out until the benzene adsorption reached 32.3% by weight. The activated charcoal obtained was washed with dilute hydrochloric acid, and then fully washed and dried with ion exchange water to remove the residual hydrochloric acid, thereby obtaining a carbonaceous material. The treatment conditions and the physical properties of the obtained carbonaceous material are shown in Table 1.

[0152] <Comparative Example 3>

[0153] A carbonaceous material was obtained in the same manner as in Example 1, except that the concentration of the oxygen-containing gas introduced during the activation treatment was changed to 0.1% by volume of oxygen and 99.9% by volume of nitrogen, and the activation treatment was performed until the amount of benzene adsorption reached 46.6% by weight. The treatment conditions and the physical properties of the obtained carbonaceous material are shown in Table 1.

[0154] <Comparative Example 4>

[0155] A carbonaceous material was obtained in the same manner as in Example 1, except that the concentration of the oxygen-containing gas introduced during the activation treatment was changed to 10.0% by volume of oxygen and 90.0% by volume of nitrogen, and the activation treatment was performed until the amount of benzene adsorption reached 53.0% by weight. The treatment conditions and the physical properties of the obtained carbonaceous material are shown in Table 1.

[0156] <Comparative Example 5>

[0157] The particle size of coconut shell charcoal obtained by carbonizing coconut shells produced in the Philippines was adjusted from 10 mesh (1.7 mm) to 30 mesh (0.5 mm). 1 kg of the coconut shell charcoal was put into a rotary kiln heated to 900°C, and an activation gas of 15% by volume of water vapor and 11% by volume of carbon dioxide was introduced at 10 L / min, and an additional gas of 0.5% by volume of oxygen and 99.5% by volume of nitrogen was introduced at 1 L / min, and an activation treatment was performed until the benzene adsorption reached about 62.3% by weight.

[0158] The activated carbon obtained was washed with dilute hydrochloric acid, and then fully washed with ion exchange water to remove the residual hydrochloric acid, and then dried to obtain a carbonaceous material. Table 1 shows the treatment conditions and the physical properties of the obtained carbonaceous material.

[0159] <Comparative Example 6>

[0160] 10 g of granular activated carbon AquaCarb 1240C manufactured by Evoqua was immersed in an aqueous solution prepared by dissolving 0.28 g of calcium chloride and 0.96 g of citric acid in 18.8 mL of ion exchange water and left to stand for 12 hours. The aqueous solution was then removed by suction filtration, and about half of the obtained calcium / citric acid impregnated activated carbon was placed in an alumina boat in a wet state and placed in a horizontal electric tubular furnace provided with a quartz tube with an inner diameter of 42 mm. Water was bubbled with 0.5% by volume of oxygen and 99.5% of nitrogen at 1 L / min, thereby introducing water vapor into the furnace and heating to 900°C, and the activation treatment was carried out until the benzene adsorption reached 56.0% by weight.

[0161] The activated carbon obtained was washed with dilute hydrochloric acid, and then fully washed with ion exchange water to remove the residual hydrochloric acid, and then dried to obtain a carbonaceous material. Table 1 shows the treatment conditions and the physical properties of the obtained carbonaceous material.

[0162] <Comparative Example 7>

[0163] The particle size of coconut shell charcoal obtained by carbonizing coconut shells produced in the Philippines was adjusted from 10 mesh (1.7 mm) to 30 mesh (0.5 mm). 1 kg of the coconut shell charcoal was put into a rotary kiln heated to 900°C, and an activation gas of 15% by volume of water vapor and 11% by volume of carbon dioxide was introduced at 10 L / min, and an additional gas of 0.5% by volume of oxygen and 99.5% by volume of nitrogen was introduced at 1 L / min, and an activation treatment was performed until the benzene adsorption reached about 31.0% by weight.

[0164] The activated carbon obtained was washed with dilute hydrochloric acid, and then fully washed with ion exchange water to remove the residual hydrochloric acid, and then dried to obtain a carbonaceous material. Table 1 shows the treatment conditions and the physical properties of the obtained carbonaceous material.

[0165]

[0166] [Evaluation of Filtration Capacity of Carbonaceous Materials]

[0167] The carbonaceous materials prepared in Examples 1 to 3 and Comparative Examples 1 to 7 were filled in a stainless steel column with a diameter of 6.2 mm, a height of 25.4 mm, and an internal volume of 0.77 mL, and the filtration capacity test of PFOA + PFOS was implemented in the order shown below according to the procedure for predicting the absorption of GAC contaminants in water systems by rapid small-scale column tests specified in ASTM D6586-03 (2014). In addition, for the carbonaceous materials used in this test, the particle size was adjusted to 120 mesh (125 μm) to 200 mesh (74 μm) and then the test was carried out.

[0168] [PFOA+PFOS filtration capacity test]

[0169] Water (containing TOC 1.2 ppm) adjusted to PFOA concentration of 50±10 ppt and PFOS concentration of 50±10 ppt was used as test water at 7.2 mL / min and space velocity (SV) = 560 hr -1 Under the condition of , water was passed in an upward flow manner, and the point where the removal rate was less than 80% was used as the breakthrough point to implement the filtration capacity test. In this test, the filtration capacity of 12000 (Bed Volumes) or more was considered qualified. The water flow test conditions and results are shown in Table 2 and Figure 3 .

[0170] Table 2

[0171]

[0172] (Inspection)

[0173] According to Table 2 and Figure 3 The results clearly show that the carbonaceous materials of the embodiments of the present invention can be used for water purifiers and have excellent PFAS removal capabilities. In particular, it can be seen that Examples 1 and 3 with an average pore diameter of 1.85 nm or more exhibited better removal capabilities.

[0174] In contrast, Comparative Examples 1 to 7, in which at least one of the amount of benzene adsorption, the amount of vitamin B12 adsorption, and the volume of mesopores did not meet the requirements of the present invention, failed to sufficiently remove PFAS. In particular, in Comparative Examples 2 and 7, in which both the amount of vitamin B12 adsorption and the volume of mesopores did not meet the requirements of the present invention, the removal rate from the start of water flow was much lower than 80%, and the PFAS removal capacity was 0.

[0175] This application is based on Japanese invention patent application No. 2020-177898 filed on October 23, 2020, the contents of which are incorporated herein by reference.

[0176] In order to describe the present invention, the present invention is appropriately and fully described above through specific embodiments, but it should be understood that those skilled in the art can easily change and / or improve the embodiments described. Therefore, as long as the modified embodiments or improved embodiments implemented by those skilled in the art do not deviate from the level of the protection scope of the claims recorded in the claims, the modified embodiments or improved embodiments can be interpreted as being included in the protection scope of the claims.

[0177] Industrial Applicability

[0178] The carbonaceous material of the present invention is particularly useful for removing fluorine-containing organic compounds. Therefore, the present invention has wide industrial applicability in water purification technologies such as water purification filters and water purifiers.

Claims

1. A carbonaceous material, It is characterized in that The benzene adsorption amount is 30-60% by mass, the vitamin B12 adsorption amount exceeds 50.0 mg / g, and the mesopore volume with a diameter of 2-50 nm calculated by the BJH method from the nitrogen adsorption isotherm is 0.13-0.30 cm 3 / g.

2. The carbonaceous material according to claim 1, It is characterized in that The specific surface area calculated from the nitrogen adsorption isotherm by the BET method is 1200-2000m 2 / g.

3. The carbonaceous material according to claim 1 or 2, It is characterized in that The average pore diameter calculated based on the total pore volume and the specific surface area according to the following formula (3) is 1.85 to 1.90 nm. The total pore volume is calculated by the Gurvish method based on the nitrogen adsorption amount at the relative pressure P / P0=0.99 of the nitrogen adsorption isotherm. [Formula (3)] Average pore diameter (nm) = total pore volume (cm 3 / g) / Specific surface area (m 2 / g)×4000.

4. The carbonaceous material according to claim 1 or 2, It is characterized in that The electrical conductivity obtained by measuring the powder resistance under a load of 12 kN is 3 to 9 S / cm.

5. The carbonaceous material according to claim 1 or 2, It is characterized in that The carbonaceous material is derived from a plant-based carbonaceous precursor.

6. The carbonaceous material according to claim 5, It is characterized in that The plant-based carbonaceous precursor is coconut shell.

7. The carbonaceous material according to claim 1 or 2, It is characterized in that The removal performance of fluorinated organic compounds obtained under the following measurement conditions is 12000 or more in terms of bed volume. Measurement conditions: Water adjusted to PFOA concentration of 50±10ppt and PFOS concentration of 50±10ppt, i.e., water containing TOC 1.2ppm, was used as test water, at 7.2mL / min, space velocity, i.e., SV=560hr -1 Under the conditions, water was passed through an upward flow method through a stainless steel column with a diameter of 6.2 mm, a height of 25.4 mm and an internal volume of 0.77 mL filled with carbonaceous material, and the water flow from the start of water flow to the breakthrough point, i.e., the bed volume, was obtained when the removal rate became less than 80% as the breakthrough point, and was used as the removal performance.

8. A method for producing a carbonaceous material, Its characteristics are A method for producing a carbonaceous material according to any one of claims 1 to 7 using a fluidized bed furnace, wherein: In addition to the fluidizing gas introduced from the furnace bed, an oxygen-containing gas is introduced into the fluidized bed furnace so that the oxygen concentration in the total gas of the fluidizing gas and the oxygen-containing gas becomes 0.004 to 1% by volume.

9. The method for producing a carbonaceous material according to claim 8, It is characterized in that The water vapor concentration in the fluidizing gas introduced from the hearth is 10 to 40% by volume.

10. The method for producing a carbonaceous material according to claim 8 or 9, It is characterized in that The fluidized bed furnace includes a gas dispersion portion on the upstream side in the fluidized bed furnace when viewed from the main flow direction Z of the fluidizing gas. When the upstream end position of the gas dispersion section in the direction Z is set to 0 in meters, the downstream end position is set to t1 in meters, and the position for introducing the oxygen-containing gas is set to t2 in meters, the oxygen-containing gas is introduced in a manner that satisfies the relationship of 0.5t1≤t2.

11. A filter for water purification, Features Include: The carbonaceous material according to any one of claims 1 to 7; and a fibrous binder, wherein The CSF value of the fibrous binder is 10 to 150 mL. The fibrous binder is contained in an amount of 4 to 10 parts by mass based on 100 parts by mass of the carbonaceous material.

12. A water purifier, Features Comprising: the carbonaceous material according to any one of claims 1 to 7.

13. A water purifier, Features It comprises: the water purification filter according to claim 11.

14. A fluorine-containing organic compound removal material, Features Comprising: the carbonaceous material according to any one of claims 1 to 7.

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