WO2015076123A1 - Deionizing sheet for use in electrode in flow-through-type capacitor - Google Patents

Deionizing sheet for use in electrode in flow-through-type capacitor Download PDF

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WO2015076123A1
WO2015076123A1 PCT/JP2014/079589 JP2014079589W WO2015076123A1 WO 2015076123 A1 WO2015076123 A1 WO 2015076123A1 JP 2014079589 W JP2014079589 W JP 2014079589W WO 2015076123 A1 WO2015076123 A1 WO 2015076123A1
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liquid
deionized
sheet
capacitor
permeable
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PCT/JP2014/079589
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French (fr)
Japanese (ja)
Inventor
昭典 河内
澤田 重明
一臣 菅原
廣和 小田
清晴 中川
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ユニチカ株式会社
学校法人関西大学
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Publication of WO2015076123A1 publication Critical patent/WO2015076123A1/en

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    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/46Treatment of water, waste water, or sewage by electrochemical methods
    • C02F1/469Treatment of water, waste water, or sewage by electrochemical methods by electrochemical separation, e.g. by electro-osmosis, electrodialysis, electrophoresis
    • C02F1/4691Capacitive deionisation
    • CCHEMISTRY; METALLURGY
    • C02TREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02FTREATMENT OF WATER, WASTE WATER, SEWAGE, OR SLUDGE
    • C02F1/00Treatment of water, waste water, or sewage
    • C02F1/46Treatment of water, waste water, or sewage by electrochemical methods
    • C02F1/461Treatment of water, waste water, or sewage by electrochemical methods by electrolysis
    • C02F1/46104Devices therefor; Their operating or servicing
    • C02F1/46109Electrodes
    • C02F2001/46133Electrodes characterised by the material

Definitions

  • the present invention uses a deionized sheet for electrodes of a liquid-permeable capacitor, a liquid-permeable capacitor using the deionized sheet, a deionized liquid manufacturing apparatus including the liquid-permeable capacitor, and the deionized liquid manufacturing apparatus.
  • the present invention relates to a method for producing a deionized liquid.
  • a method for removing an ionic substance contained in a liquid such as water a chemical precipitation method, an ion exchange method, a reverse osmosis membrane method, a method using the principle of an electric double layer, and the like are known.
  • the ionic substance in the method using the principle of the electric double layer, the ionic substance can be adsorbed / released by repeatedly storing and discharging the electric energy at the electrode. It has the advantage that ionic substances can be removed (adsorbed / released).
  • a method using the principle of the electric double layer a method using a liquid-passing capacitor composed of a laminate in which electrodes are arranged via a separator is known.
  • a liquid containing an ionic substance is passed through such a laminate, and a voltage is applied between the electrodes while the liquid is passed to adsorb the ionic substance on the electrode surface.
  • a voltage is applied between the electrodes while the liquid is passed to adsorb the ionic substance on the electrode surface.
  • an active carbon layer mainly composed of high specific surface area activated carbon is disposed with a separator made of an electrically insulating porous liquid-permeable sheet interposed therebetween, and a collector electrode is disposed outside the activated carbon layer.
  • a flat plate-shaped liquid-type electric double layer capacitor having a configuration in which a holding plate is disposed outside the collector electrode is disclosed.
  • a liquid passing type electric double layer capacitor that has a high and stable removal rate of ionic substances and can be implemented on an industrial scale is provided. It is described that it is done.
  • Patent Document 2 includes a laminate in which a plurality of electrodes capable of passing liquids and a plurality of separators capable of passing liquids are alternately stacked, and the electrodes include activated carbons capable of passing liquids including activated carbon powder and a binder.
  • a liquid-permeable capacitor comprising a sheet, wherein the activated carbon powder has a center particle diameter of 10 to 500 ⁇ m, and the binder includes at least one selected from fibrillated fibers and thermoplastic binder particles.
  • the liquid-passing capacitor disclosed in Patent Document 2 it is described that a liquid-passing capacitor having a higher ability to remove ionic substances than a conventional liquid-passing capacitor can be obtained.
  • activated carbon may be used for electrodes constituting the laminate as in Patent Document 1 and Patent Document 2, for example.
  • a liquid-flowing capacitor using activated carbon as disclosed in Patent Document 1 and Patent Document 2 if the ion removal rate per unit volume is to be increased, the removal is difficult. It has been clarified that the flow rate per unit time of the liquid supplied to the ions is small, and it may take a long time to remove the ions. On the contrary, it has been clarified that the ion removal rate per unit volume may decrease when the flow rate per unit time of the liquid used for deionization is increased.
  • a main object of the present invention is to provide a deionization sheet for a flow-through capacitor that can provide a high ion removal rate and a high flow rate to the flow-through capacitor. Furthermore, the present invention provides a liquid-permeable capacitor using the deionized sheet, a deionized liquid manufacturing apparatus including the liquid-permeable capacitor, and a method of manufacturing a deionized liquid using the deionized liquid manufacturing apparatus. Also aimed.
  • the present inventor has intensively studied to solve the above problems.
  • the deionized sheet for electrodes of liquid-permeable capacitors containing activated carbon fibers the deionized sheet is formed by a wet papermaking method, and thus has a high ion removal rate compared to liquid-permeable capacitors. It has been found that a high liquid flow rate can be provided. Further, the present inventor can provide such a deionized sheet with a particularly excellent ion removal rate and liquid flow rate when the liquid-passing capacitor is allowed to naturally flow by the dead weight of the liquid used for deionization. I found. The present invention has been completed by further studies based on these findings.
  • a deionized sheet for electrodes of liquid-permeable capacitors containing activated carbon fibers is a deionized sheet for electrodes of a liquid-permeable capacitor, which is formed by a wet papermaking method.
  • Item 2. In the pore distribution determined by the DH method using a nitrogen adsorption isotherm at 77.4K, the mesopore volume in the range of pore diameters of 20 mm or more and less than 500 mm is 0.002 to 0.8 ml / g, and the total pores Item 2.
  • Item 3. Item 3. The deionized sheet for electrodes of a liquid-permeable capacitor according to Item 1 or 2, wherein the activated carbon fiber includes at least one selected from the group consisting of Mg, Mn, Fe, Y, Pt, and Gd.
  • Item 4. A liquid-permeable capacitor comprising a laminate in which electrodes and separators are alternately laminated, 4. The liquid passing type capacitor, wherein the electrode has a deionizing sheet for a liquid passing type capacitor electrode according to any one of Items 1 to 3.
  • Item 5. Item 4.
  • the liquid-passing capacitor according to Item 4 A power source electrically connected to the electrode of the liquid-permeable capacitor; A container for accommodating the liquid-flow type capacitor; With In the liquid passing type capacitor, the electrode to which the positive electrode side of the power source is electrically connected and the electrode to which the negative electrode side is electrically connected are alternately arranged in the stacking direction of the stacked body through the separator. Are stacked, In the container, a deionized liquid production apparatus in which a liquid to be deionized is passed from one side to the other side in the stacking direction of the liquid passing type capacitor. Item 6. Item 6. The deionized liquid production apparatus according to Item 5, wherein the liquid supplied to the deionization is passed by its own weight. Item 7.
  • a method for producing a deionized liquid using the deionized liquid production apparatus according to Item 5 or 6 A method for producing a deionized liquid, wherein a voltage is applied between the electrodes while flowing a liquid to be used for deionization from one side to the other side in the stacking direction of the liquid-permeable capacitor.
  • Item 8. Use of a sheet containing activated carbon fiber and formed by a wet papermaking method for deionization of an electrode of a liquid-pass capacitor.
  • Item 9. A method for deionizing an electrode of a liquid-permeable capacitor using a deionized sheet containing activated carbon fibers and formed by a wet papermaking method as a deionized sheet for an electrode of a liquid-permeable capacitor.
  • seat for liquid flow type capacitors which can provide the high ion removal rate per unit volume and the high liquid flow rate per unit time with respect to a liquid flow type capacitor is provided. it can. Furthermore, according to the present invention, a liquid-permeable capacitor using the deionized sheet, a deionized liquid production apparatus including the liquid-permeable capacitor, having a high ion removal rate and a high liquid flow rate, and the desorption A method for producing a deionized liquid using an ionic liquid production apparatus can be provided.
  • a deionization sheet for a flow-through capacitor according to the present invention, a liquid-flow capacitor using the deionization sheet, a deionization liquid production apparatus including the liquid-flow capacitor, and a deionization using the deionization liquid production apparatus
  • the manufacturing method of an ionic liquid is explained in full detail.
  • Deionized sheet for liquid-permeable capacitors is a deionized sheet for electrodes of liquid-permeable capacitors containing activated carbon fibers, and the deionized sheet is formed by a wet papermaking method. It is characterized by being made.
  • Examples of the type of activated carbon fiber contained in the deionized sheet of the present invention include, for example, polyacrylonitrile-based, rayon-based, phenolic resin-based, coal pitch-based, petroleum pitch-based fibers, etc., which are infusible and optionally carbonized.
  • Any activated carbon fiber produced by activation by holding at a predetermined temperature for a predetermined time in an atmosphere containing water vapor and carbon dioxide can be employed.
  • activated carbon fibers using coal pitch and petroleum pitch as raw materials are preferable from the viewpoint of imparting a high ion removal rate and a high liquid flow rate to the liquid flow type capacitor.
  • Activated carbon fiber may be used individually by 1 type, and may be used in combination of 2 or more types.
  • the activated carbon fiber has a mesopore volume Vf meso of 0.02 to 0.8 ml in a pore diameter range of 20 mm or more and less than 500 mm in the pore distribution determined by the BJH method using a nitrogen adsorption isotherm at 77.4K. It is preferable that the ratio Rf meso of the mesopore volume to the total pore volume is 5 to 45%. Since the mesopore volume of the activated carbon fiber and the ratio of the mesopore volume to the total pore volume are in the above range, a higher ion removal rate and a higher liquid flow rate for the liquid passing type capacitor Can be granted.
  • Mesopore refers to a pore having a pore diameter of 20 to 500 mm
  • micropore refers to a pore having a pore diameter of less than 20 mm.
  • the pore distributions of the activated carbon fiber and the deionized sheet for the liquid-flow type capacitor are respectively calculated based on the nitrogen adsorption isotherm at 77.4K, and specifically, as follows.
  • a nitrogen adsorption isotherm is created.
  • the activated carbon fiber or the deionized sheet for a flow-through capacitor is cooled to 77.4 K (the boiling point of nitrogen), nitrogen gas is introduced, and the adsorption amount of nitrogen gas V [ml / g] is measured by the volume method.
  • the pressure P [mmHg] of the nitrogen gas to be introduced is gradually increased, and the value obtained by dividing by the saturated vapor pressure P 0 [mmHg] of the nitrogen gas is set as the relative pressure P / P 0 , and the adsorption amount with respect to each relative pressure is plotted.
  • the adsorption amount of nitrogen gas can be carried out by using a commercially available automatic gas adsorption amount measuring device (for example, trade name “AUTOSORB-6” (manufactured by QUANTCHROME), trade name “BELSORP-mini” (manufactured by Nippon Bell Co., Ltd.), etc.) .
  • the pore distribution can be obtained according to a known analysis method based on the nitrogen adsorption isotherm. For this analysis, known means such as an analysis program attached to the apparatus can be used.
  • the mesopore volume Vf meso of the activated carbon fiber is calculated by the BJH method based on the above pore distribution, and the micropore volume Vf micro is calculated by the t-plot method based on the above pore distribution.
  • the mesopore volume Vs meso of a deionized sheet for a flow-through capacitor to be described later is calculated by the DH method based on the above pore distribution, and the micropore volume Vs micro is t ⁇ based on the above pore distribution. Calculate by the plot method.
  • the BJH method is a known method, and specifically, the method disclosed in “J. Amer. Chem. Soc., 73, 373 (1951))” is employed.
  • the DH method is specifically the method disclosed in “D. Dollimore, GR Heal, J. Colloid Interface Sci., 33 508 (1970)”.
  • the total pore volume Vf total of the activated carbon fiber and the total pore volume Vs total of the deionized sheet for the liquid-flow capacitor are respectively the maximum adsorption of nitrogen in the measurement results of the adsorption amount of the nitrogen gas. It can be calculated from the quantity.
  • the ratio Rf meso of the mesopore volume with respect to the total pore volume of the activated carbon fiber is expressed by the following formula (1), and the ratio of the mesopore volume with respect to the total pore volume of the deionized sheet for a liquid-permeable capacitor Rs meso Is calculated by the following equation (2).
  • Rf meso Vf meso / Vf total ⁇ 100 (%) (1)
  • Rs meso Vs meso / Vs total ⁇ 100 (%) (2)
  • the mesopore volume Vf meso of the activated carbon fiber is more preferably about 0.15 to 0.8 ml / g. preferable.
  • the ratio Rf meso of the mesopore volume to the total pore volume of the activated carbon fiber is more preferably about 20 to 80%.
  • the specific surface area of the activated carbon fibers is preferably about 700 to 2500 m 2 / g, more preferably 1000 to 2000 m. About 2 / g.
  • the total pore volume of the activated carbon fiber is about 0.30 to 1.50 ml / g, the micropore volume is about 0.25 to 1.30 ml / g, and the mesopore mode diameter is about 5 to 70 mm.
  • the “mesopore mode diameter” in the present invention means the pore diameter where the peak of the pore volume distribution in the mesopore region of 20 to 500 mm calculated by the BJH method based on the above pore distribution is located. .
  • the activated carbon fiber has these physical properties, a higher ion removal rate and a higher liquid flow rate can be imparted to the liquid passing type capacitor.
  • the activated carbon fiber preferably contains at least one metal component selected from the group consisting of Mg, Mn, Fe, Y, Pt, and Gd.
  • the activated carbon fiber can be an activated carbon fiber having a specific mesopore mode diameter by including these metal components.
  • the activated carbon fiber has the following structure and characteristics depending on the type of the metal component contained.
  • the average fiber diameter of the activated carbon fiber is preferably 30 ⁇ m or less, more preferably about 5 to 20 ⁇ m.
  • the average fiber diameter of the activated carbon fiber has such a value, a higher ion removal rate and a higher liquid flow rate can be imparted to the liquid passing type capacitor.
  • the average fiber length of the activated carbon fiber is not particularly limited as long as it can be formed into a sheet shape, but is preferably about 0.5 to 50 mm, more preferably about 3 to 25 mm. When the average fiber length is in such a range, sufficient strength can be imparted to the deionized sheet, and the dispersibility in the liquid is increased in the wet papermaking method described later, thereby forming a uniform sheet. It becomes easy to do.
  • the fiber length of the activated carbon fiber in the deionized sheet formed by the wet papermaking method is preferably 3 mm or less. In order to make it 3 mm or less, it becomes easy by beating with a beating machine.
  • the average fiber diameter of the activated carbon fiber of the present invention is a value measured by an image processing fiber diameter measuring apparatus (based on JIS K 1477). Further, the average fiber length of the activated carbon fiber is a value measured using image measurement software, a trade name “MicroMeasure” (manufactured by SCARA), and the like.
  • the activated carbon fiber as described above can be produced by a known method, for example, by the method described in JP-A No. 2004-182511.
  • Examples of commercially available activated carbon fibers include A-15 manufactured by Adol.
  • the content of the activated carbon fiber in the deionized sheet of the present invention is not particularly limited as long as the effect of the present invention is achieved, but is preferably 10% by mass or more, more preferably about 10 to 95% by mass, and still more preferably. About 45 to 95% by mass.
  • the ratio of the activated carbon fiber in the deionized sheet of the present invention has such a value, a higher ion removal rate and a higher liquid flow rate can be imparted to the liquid passing type capacitor.
  • about 80 to 95% by mass is particularly preferable from the viewpoint that a particularly excellent ion removal rate and liquid flow rate can be provided when the liquid-passing capacitor is naturally passed by its own weight for deionization.
  • the deionized sheet of the present invention is formed by a wet papermaking method. That is, the deionized sheet of the present invention is obtained by molding the above activated carbon fiber into a sheet by a wet papermaking method. Since the deionized sheet of the present invention is formed by a wet papermaking method, both a high ion removal rate and a high liquid flow rate can be achieved as compared with a conventional deionized sheet. In the present invention, the details of the mechanism by which such a special effect is achieved are not clear, but can be considered as follows, for example.
  • the deionized sheet of the present invention is formed by a wet papermaking method, the average fiber length of the activated carbon fibers tends to be short, and the activated carbon fibers are uniformly distributed. For this reason, in the deionized sheet, the activated carbon fibers can be formed at a high density, and can be formed into a sheet having low resistance when passing through. Furthermore, when using the binder mentioned later, the fall of the specific surface area of the activated carbon fiber resulting from the fusion
  • the wet papermaking method in the present invention will be specifically described.
  • a raw material containing activated carbon fibers is dispersed and mixed in a liquid to prepare a slurry.
  • the activated carbon fibers are dispersed.
  • the slurry is made by a wet paper making method and formed into a sheet. That is, for the formation of the sheet, a paper machine or the like is used, and solid-liquid separation is performed so that the solid content in water is made into a sheet shape in the manner of papermaking.
  • the deionized sheet of the present invention is obtained by drying the obtained wet sheet.
  • the liquid in which the activated carbon fiber is dispersed preferably includes water and alcohol, and preferably includes water.
  • the ratio of the activated carbon fiber in the input raw material is not particularly limited as long as the activated carbon fiber is uniformly dispersed in the slurry, and examples thereof include about 10 to 95% by mass. From the viewpoint that a higher ion removal rate and a higher liquid flow rate can be imparted to the liquid flow type capacitor, 45 to 95% by mass is preferable. Further, in the case where the liquid-passing capacitor is naturally passed by its own weight for deionization, 80 to 95% by mass is particularly preferable from the viewpoint that a particularly excellent ion removal rate and liquid flow rate can be provided.
  • the deionized sheet of the present invention preferably contains a binder.
  • heat treatment is performed at a temperature equal to or higher than the temperature at which at least a part of the binder melts, whereby the activated carbon fiber and binder in the deionized sheet And the mechanical strength of the binder can be increased.
  • the ratio of the binder in the input raw material is not particularly limited as long as the activated carbon fibers are uniformly dispersed in the slurry, and examples thereof include about 3 to 90% by mass. From the viewpoint that a higher ion removal rate and a higher liquid flow rate can be imparted to the liquid flow type capacitor, 3 to 50% by mass is preferable. Further, in the case where the liquid-passing capacitor is naturally passed by its own weight for deionization, 3 to 15% by mass is particularly preferable from the viewpoint of providing a particularly excellent ion removal rate and liquid flow rate.
  • the binder is not particularly limited as long as it can increase the mechanical strength of the deionized sheet, but binder fibers such as acrylic fibers, polyolefin fibers, and polyester fibers are preferable.
  • a binder may be used individually by 1 type and may be used in combination of 2 or more types.
  • the binder fiber is preferably a heat-fusible fiber formed of two or more polymers having different melting points or softening points. More preferably, the high melting point polymer is a core component and the low melting point polymer is a sheath component. And synthetic fibers having a core-sheath structure. Specific examples of the binder fiber having a core-sheath structure include a synthetic fiber (polyolefin-based composite fiber) having a core part made of polypropylene and a sheath part made of modified polyethylene, a core part made of polyethylene terephthalate, and a sheath part made of polyolefin.
  • Synthetic fiber polyolefin-polyester composite fiber
  • a synthetic fiber polybased composite fiber having a core part made of polyethylene terephthalate and a sheath part made of a low melting point (low softening point) polyester.
  • a commercially available product can be used as the synthetic fiber having a core-sheath structure.
  • a polyester composite fiber marketed under the trademark of Melty by Unitika Trading Co., Ltd. is preferable.
  • a binder fiber having a core-sheath structure By using a binder fiber having a core-sheath structure, a binder fiber having a high melting point polymer as a core component and a low melting point polymer as a sheath component is sufficiently dispersed and mixed, and both fibers are uniformly dispersed to form a composite. It can be made into the state which carried out. Further, when using a binder fiber having a core-sheath structure, the wet sheet obtained by the above solid-liquid separation is heat-treated at a temperature not lower than the melting point of the sheath component of the binder fiber and not higher than the melting point of the core component minus -20 ° C. Thus, a deionized sheet having excellent mechanical strength can be obtained.
  • the average fiber length of the binder fiber is preferably about 1 to 50 mm, more preferably about 3 to 25 mm.
  • the average fiber diameter of the binder fiber is preferably about 2 to 100 ⁇ m, more preferably about 5 to 50 ⁇ m.
  • synthetic pulp can be added to the slurry to improve the strength of the sheet after papermaking.
  • Synthetic pulp is, for example, one made of a thermoplastic polymer such as polyolefin-based, acrylic-based, polyimide-based, aromatic polyamide-based, wholly aromatic polyester-based, or cellulose-based pulp-like multibranched fiber. These synthetic pulps, when dispersed in a liquid, have a very strong trapping power for other materials, so that a high strength sheet can be produced by a wet papermaking method with a small amount of synthetic pulp added.
  • synthetic pulp commercially available products can be used. For example, an acrylic synthetic pulp marketed by Toyobo under the trademark BiPUL is preferable.
  • the ratio of the synthetic pulp in the input raw material is not particularly limited as long as the activated carbon fibers are uniformly dispersed in the slurry, and examples thereof include about 1 to 90% by mass. From the viewpoint that a higher ion removal rate and a higher liquid flow rate can be imparted to the liquid flow type capacitor, 1 to 50% by mass is preferable. Further, in the case where the liquid-passing capacitor is naturally passed by its own weight for deionization, 1 to 10% by mass is particularly preferable from the viewpoint that a particularly excellent ion removal rate and liquid flow rate can be provided.
  • heating is performed under a pressing pressure of a surface pressure of 0.1 kgf / cm 2 or more, and then cooling is performed while maintaining the pressing pressure. It is also possible to do.
  • a binder When preparing the slurry, for example, a binder may be used as necessary.
  • the binder is preferably a solid component added in an amount of less than 3% by mass, particularly less than 1% by mass.
  • the binder may be, for example, a bound anion such as an acrylic polymer or styrene-butadiene polymer containing a bound sulfonium group, isothiouronium group, pyridinium group, quaternary ammonium group, sulfate group, sulfonate group or carboxylate group.
  • examples thereof include polymer latex made of an organic polymer having an ionic or cationic charge and substantially insoluble in water.
  • Suitable organic flocculants include various organic flocculants such as aluminum polychloride (aluminum hydroxychloride), partially hydrolyzed polyacrylamide, modified cationic polyacrylamide, diallyl diethylammonium chloride and the like.
  • the amount of the flocculant added is less than 3% by mass of the sheet, preferably less than 1% by mass.
  • slurry viscosity modifiers such as a xanthan gum, can also be used, for example. It is preferable that the addition amount of such a thickener is less than 2 mass% of the activated carbon fiber sheet.
  • the deionized sheet of the present invention has a mesopore volume Vs meso in the range of pore diameters of 20 mm or more and less than 500 mm in the pore distribution determined by the DH method using a nitrogen adsorption isotherm at 77.4 K of 0.002 to 0.8 ml. It is preferable that the ratio Rs meso of the mesopore volume to the total pore volume is 1 to 80%. In the present invention, when the deionization sheet has these physical property values, a higher ion removal rate and a higher liquid flow rate can be imparted to the liquid flow type capacitor.
  • the mesopore volume Vs meso , the micropore volume Vs micro , and the ratio Rs meso of the mesopore volume to the total pore volume of the deionized sheet of the present invention are values measured by the method described above. is there.
  • the mesopore volume Vs meso of the deionized sheet is more preferably about 0.15 to 0.8 ml / g. preferable. From the same viewpoint, the ratio of the mesopore volume to the total pore volume is more preferably about 20 to 80%.
  • the deionized sheet of the present invention preferably has the following physical properties.
  • the micropore volume is preferably about 0.2 to 1.30 ml / g, more preferably about 0.5 to 1.30 ml / g.
  • the total pore volume is preferably about 0.5 to 1.50 ml / g, more preferably about 0.7 to 1.50 ml / g.
  • the specific surface area is preferably about 700 to 2500 m 2 / g, more preferably about 1000 to 2500 m 2 / g.
  • the thickness of the deionized sheet of the present invention is preferably about 0.2 to 1.2 mm, more preferably about 0.5 to 0.9 mm. When the thickness of the deionized sheet is in such a range, a higher ion removal rate and liquid flow rate can be imparted to the liquid flow type capacitor.
  • the deionized sheet of the present invention is used as a liquid-type capacitor
  • the deionized sheet is preferably pressed and compressed in the thickness direction, and the thickness after compression is preferably about 0.35 to 0.60 mm. Is about 0.40 to 0.55 mm.
  • the thickness of the deionized sheet is in such a range, a particularly high ion removal rate and liquid flow rate can be imparted to the liquid flow type capacitor.
  • the basis weight of the deionized sheet of the present invention is preferably about 30 to 200 g / m 2 , more preferably about 30 to 130 g / m 2 , and still more preferably about 70 to 90 g / m 2 .
  • a higher ion removal rate and liquid flow rate can be provided to the liquid flow type capacitor.
  • the deionized sheet formed by the wet papermaking method of the present invention is used in a liquid-passing capacitor (deionized liquid production apparatus), it is surprising that the liquid used for deionization By being naturally passed by its own weight, a particularly excellent ion removal rate and liquid flow rate can be exhibited.
  • the deionized sheet of the present invention can be suitably used for, for example, a liquid-permeable capacitor and a deionized liquid manufacturing apparatus including the same. can do.
  • liquid-permeable capacitor of the present invention uses the above-described deionized sheet of the present invention.
  • the liquid-permeable capacitor of the present invention includes a laminate in which electrodes and separators are alternately laminated, and the electrodes have the deionized sheet.
  • the electrode is not particularly limited as long as it has the above deionization sheet.
  • the electrode preferably includes a collecting electrode. It is preferable.
  • the laminated structure of the liquid-permeable capacitor of the present invention will be described with reference to the schematic cross-sectional view of FIG.
  • the electrodes 2 and the separators 3 are alternately laminated.
  • the deionized sheet 21 is formed on the collector electrode 22.
  • An insulating separator 3 is disposed between the plurality of deionized sheets 21.
  • the laminated body 1 constituting the liquid-permeable capacitor has a laminated structure of electrode 2 (collector electrode 21 / deionized sheet 22) / separator 3 / electrode 2 (deionized sheet 21 / collector electrode 22).
  • FIG. 1 shows a case where two such laminated structures are continuously formed (the total number of collector electrodes, deionized sheets, and separators is nine). ing.
  • the collector electrode is not particularly limited as long as it is made of a conductive material, and for example, a copper plate, an aluminum plate, a carbon plate, foil-like graphite, or the like that can be in close contact with the deionized sheet can be used.
  • a liquid passage hole may be provided in the collector electrode.
  • the thickness of the collector electrode is preferably about 0.01 to 1 mm, more preferably about 0.02 to 0.5 mm.
  • the separator is not particularly limited as long as it has liquid permeability and insulating properties, and examples thereof include filter paper and nonwoven fabric.
  • the thickness of the separator is preferably about 30 to 300 ⁇ m, more preferably about 50 to 250 ⁇ m.
  • the total number of layers constituting the laminate such as a deionized sheet, a separator, and a collector electrode is the size of the target liquid-permeable capacitor and the ion removal performance per unit volume.
  • the flow rate per unit time can be appropriately set. For example, 10 layers or more, preferably about 40 to 100 layers can be mentioned.
  • the height (thickness in the stacking direction) of the laminated body constituting the liquid-permeable capacitor of the present invention is appropriately determined according to the size of the target liquid-permeable capacitor, the ion removal performance, and the liquid flow rate per unit time. From the viewpoint of improving the compactness, ion removal performance, and flow rate per unit time, for example, 5 mm or more, preferably about 20 to 50 mm can be mentioned.
  • the height of the laminate is generally increased by increasing the number of layers constituting the laminate and the thickness of each layer, but the height can be adjusted by applying pressure in the stacking direction of the laminate. The higher the pressure applied to the laminate, the lower the height of the laminate and the higher the density of the laminate, so that the ion removal rate per unit volume can be increased, but the flow rate per unit time decreases. To do.
  • the cross-sectional area in the direction perpendicular to the height direction of the multilayer body depends on the size of the target liquid-permeable capacitor, the ion removal performance, and the liquid flow rate per unit time.
  • the liquid-passing capacitor of the present invention is a deionized sheet formed by a wet papermaking method, even if the liquid-passing capacitor is compact, while suppressing a decrease in the liquid flow rate per unit time, A high ion removal rate per unit volume can be achieved. Further, by making it compact, for example, when it is a pot type water purifier, it can be accommodated in a household refrigerator.
  • the liquid-permeable capacitor of the present invention can be suitably used in a deionized liquid production apparatus, and can be applied to a deionized liquid production apparatus as described below, for example.
  • the deionized liquid manufacturing apparatus of the present invention includes the above-described liquid passing type capacitor of the present invention.
  • a deionized liquid production apparatus of the present invention includes the above-described liquid-flowing capacitor, a power source, and a container.
  • the power source is electrically connected to the electrode of the liquid-pass capacitor.
  • the electrode electrically connected to the positive electrode side of the power source and the electrode electrically connected to the negative electrode side are alternately stacked in the stacking direction of the stacked body through the separator.
  • the container contains a liquid passing type capacitor. In the container, a liquid to be used for deionization is passed from one side in the stacking direction of the liquid passing type capacitor toward the other side.
  • the size and shape of the container are not particularly limited as long as the above-described liquid-permeable capacitor can be accommodated, but the liquid used for deionization between all the electrodes of the liquid-permeable capacitor Therefore, the container preferably has an internal space along the shape of the liquid-permeable capacitor in the stacking direction.
  • the flow of the liquid to be used for deionization may be controlled by a pump or the like so that the flow rate of the liquid is constant, or may be performed by natural flow by the weight of the liquid.
  • the liquid flow rate (ml / min) per unit time is preferably 20 ml / min or more, more preferably about 50 to 120 ml / min.
  • the said liquid flow amount is an average value from the liquid flow start to the completion of liquid flow.
  • the liquid subjected to deionization is not particularly limited as long as it is a liquid containing ions, and examples thereof include water, seawater, waste liquid, and the like. Among these, water such as tap water and hard water is exemplified. Further, the ionic substance to be removed is not particularly limited, and examples thereof include an electrolyte that can dissociate into ions in a liquid such as a metal salt, an amine salt, an ammonium salt, an inorganic acid, or an organic acid.
  • the deionized liquid production apparatus of the present invention can be particularly suitably used as a method for producing deionized water of hard water containing about 5 to 600 ppm of metal ions.
  • the ion removal rate is 75% or more when the liquid is passed at 100 ml / min and a voltage of 1.5 V is applied.
  • 1 L of hard water can be softened efficiently in a short time, and can be particularly suitable as a pot-type water purifier used in general households.
  • the pore distribution of the activated carbon fiber, the specific surface area, the average fiber length, the average fiber diameter and Content, content of binder and / or synthetic pulp, thickness and basis weight of deionized sheet, total number of layers constituting laminate such as deionized sheet, separator, collector electrode, lamination constituting liquid-permeable capacitor This can be achieved by appropriately adjusting the height of the body.
  • Hardness (ppm) Ca 2+ (ppm) ⁇ 2.5 + Mg 2+ (ppm) ⁇ 4.1 (3)
  • the method for producing a deionized liquid of the present invention can be performed using the above-described deionized liquid manufacturing apparatus of the present invention. That is, the voltage between the electrodes of the flow-through capacitor is passed while flowing the liquid used for deionization from one side to the other side in the stacking direction of the flow-through capacitor provided in the deionized liquid production apparatus. Apply. As a result, cations contained in the liquid being passed are adsorbed on the anode side electrode, anions are adsorbed on the cathode side, ionic substances are removed from the liquid, and a deionized liquid is produced.
  • the voltage applied between the electrodes is not particularly limited, and for example, about 0.5 to 5 V can be mentioned.
  • the positive electrode of the power supply is on one side of the electrodes facing each other, and the negative electrode of the power supply is on the other side Can be electrically connected to each other.
  • the ionic substance adsorbed on the electrode can be released from the electrode surface by applying no voltage or reverse voltage. For this reason, the ionic substance adsorbed on the electrode can be discharged as a liquid containing a high concentration of ionic substance.
  • Example 1 A deionized sheet was prepared by the following wet papermaking method. 87 parts by mass of activated carbon fiber (A-15 manufactured by Adol) and a polyester-composite fiber (Melty 4080, 2.2 dtex ⁇ ) having a core-sheath structure in which the softening point of the sheath is 80 ° C. and the melting point of the core is 250 ° C.
  • aqueous slurry in which 10 parts by mass of 5 mm (manufactured by Unitika) and 3 parts by mass of acrylic fiber (BiPUL, manufactured by Toyobo Co., Ltd.) as synthetic pulp was mixed and sheared in water using a beating machine to prepare a uniformly dispersed aqueous slurry.
  • the obtained aqueous slurry was flowed on a wire at a predetermined flow rate to form a solid content in water into a sheet, and then the sheet was dried by a dryer part through a press part. Further, the surface of the sheet was smoothed with a calendar part and wound up with a reel to obtain a deionized sheet.
  • the specific surface area of the activated carbon fiber used in Example 1 was a specific surface area of 1730 m 2 / g.
  • the specific surface area was measured by the BET method (one-point method) using nitrogen as an adsorbed substance.
  • the nitrogen gas adsorption amount of the activated carbon fiber was measured using a trade name “AUTOSORB-6” (manufactured by QUANTCHROME).
  • the analysis of the pore distribution was carried out with the attached analysis program.
  • the total pore volume Vf total of the activated carbon fiber was 0.81 ml / g.
  • the total pore volume was calculated from the maximum adsorption amount of nitrogen.
  • Table 1 shows g), mesopore volume Vs meso (ml / g), total pore volume Vs total (ml / g), and the ratio Rs meso (%) of the mesopore volume to the total pore volume.
  • the specific surface area (m 2 / g), micropore volume (ml / g), mesopore volume (ml / g), and total pore volume (ml / g) of the deionized sheet are trade names “BELSORP”.
  • the nitrogen gas adsorption amount is measured, the specific surface area is the BET method, the micropore volume Vs micro is the t-plot method, the mesopore volume Vs meso is the DH method, the total The pore volume Vs total is a value calculated from the maximum adsorption amount of nitrogen.
  • the maximum fiber length of the activated carbon fiber in the obtained deionized sheet was 2 mm (that is, the fiber length of the activated carbon fiber in the deionized sheet was 3 mm or less).
  • Deionized sheet obtained above, separator (filter paper No. 5C manufactured by Advantech, thickness 0.22 mm), and collector electrode provided with a tab (graphite foil sheet, PERMA-FOIL manufactured by Toyo Tanso Co., Ltd., thickness 0.05mm) is cut into a ring shape having an outer diameter of 82 mm and an inner diameter of 25 mm, respectively, and the collector electrode, the deionized sheet, the separator, the deionized sheet, and the collector electrode are laminated in this order so that there are a total of 54 layers.
  • a laminate liquid-passing type capacitor
  • the height of the laminated body was adjusted to 25 mm by applying a pressure of about 5 MPa to the laminated body in the lamination direction.
  • the obtained laminate is filled into a vinyl chloride resin cylindrical container having an outer diameter of 140 mm, an inner diameter of 125 mm, and a height of 110 mm, and the negative electrode side and the positive electrode side of the power source are alternately arranged.
  • An electrode terminal was connected to the tab of the electrode to obtain a deionized liquid production apparatus equipped with a liquid passing type capacitor.
  • a water supply tank (volume 2 L) is mounted on the container of the deionized liquid production apparatus, 1 L of the hard water is filled in the water supply tank, and the liquid-passing capacitor is naturally passed by its own weight. Made it water. The average flow rate until all hard water was passed was 100 ml / min. Note that a voltage of 1.5 V was applied to each electrode while passing the hard water. The electrical conductivity of the treated water that passed through the liquid-type capacitor was measured, and the ion removal rate from the hard water was determined from the electrical conductivity of the hard water targeted for deionization and the electrical conductivity of the treated water. The results are shown in Table 2.
  • Example 1 A deionized liquid production apparatus equipped with a liquid-flow type capacitor was obtained in the same manner as in Example 1 except that Kyonoru (product number ACC-5092-15) manufactured by Gunei Chemical Industry Co., Ltd. was used as the deionized sheet. Kynol is not a wet papermaking method but an activated carbon fiber sheet produced by carbonizing a textile sheet.
  • the specific surface area (m 2 / g), micropore volume (ml / g), mesopore volume (ml / g), and total pore volume (ml / g) of the deionized sheet are as described above. It is a value calculated by the method.
  • Comparative Example 2 A deionized liquid production apparatus including a liquid-permeable capacitor was obtained in the same manner as in Comparative Example 1 except that the pressure applied when forming the laminate was reduced and the height of the laminate was adjusted to 36 mm. Next, the hard water was naturally passed in the same manner as in Example 1 to obtain the ion removal rate from the hard water. The results are shown in Table 2. In the deionized liquid production apparatus of Comparative Example 2, the water flow rate until all hard water was passed was 100 ml / min on average.
  • Example 2 Deionization provided with a liquid-flow type capacitor in the same manner as in Example 1 except that the pressure applied when forming the laminate was slightly weaker than that in Example 1 and the height of the laminate was 27 mm. A liquid production apparatus was obtained. Next, the hard water was naturally passed in the same manner as in Example 1 to obtain the ion removal rate from the hard water. The results are shown in Table 3. In addition, in the deionization liquid manufacturing apparatus of Example 2, the water flow rate until all hard water was passed was 130 ml / min on average.
  • Example 3 Deionization provided with a liquid-permeable capacitor in the same manner as in Example 1 except that the pressure applied when forming the laminate was further weakened compared to Example 2 and the height of the laminate was 30 mm. A liquid production apparatus was obtained. Next, the hard water was naturally passed in the same manner as in Example 1 to obtain the ion removal rate from the hard water. The results are shown in Table 3. In addition, in the deionized liquid manufacturing apparatus of Example 3, the water flow rate until all hard water was passed was 170 ml / min on average.
  • Example 4 A liquid-permeable capacitor is provided in the same manner as in Example 1 except that the number of layers of the laminated body is increased from 54 to 81 and the height of the laminated body is 37.5 mm. A deionized liquid production apparatus was obtained. Next, the hard water was naturally passed in the same manner as in Example 1 to obtain the ion removal rate from the hard water. The results are shown in Table 3. In addition, in the deionized liquid manufacturing apparatus of Example 4, the water flow rate until all hard water was passed was 120 ml / min on average.
  • Example 3 in the deionized liquid production apparatus of Example 2 in which the thickness of the laminate was made larger than that of Example 1 to reduce the density of the layer, the average water flow rate was 130 ml. The ion removal rate was high despite the increase to 1 / min. Further, in the deionized liquid production apparatus of Example 3 in which the thickness of the laminate was further increased and the layer density was reduced as compared with Example 2, the average water flow rate was increased to 170 ml / min. Nevertheless, it had a relatively high ion removal rate.
  • the ion removal rate and the flow rate are as follows. We were able to greatly improve both.
  • Example 5 Using the pump, the same procedure as in Example 1 was performed except that the flow rate of hard water until all the hard water was passed in the deionized liquid production apparatus of Example 1 was kept constant (100 ml / min). The removal rate of ions from hard water was determined. The results are shown in Table 4.
  • Example 5 where the water flow rate was forcibly controlled by a pump, deionization could be produced, but the ion removal rate was lower than in Example 1 where natural water flow was performed. did.
  • the deionized liquid production apparatus using the deionized sheet formed by the wet papermaking method ions that are particularly excellent in natural water flow due to the dead weight of the liquid used for deionization, rather than forced water flow by the pump. It became clear that a removal rate and a liquid flow rate could be provided.
  • the liquid-passing capacitors of Examples 1 to 4 in which natural water was passed are very compact with an outer diameter of 82 mm and a height of 25 to 37.5 mm.

Abstract

[Problem] To provide a deionizing sheet for use in a flow-through-type capacitor, which can impart both a high ion removal ratio per unit volume and a high passing flow amount per unit time to a flow-through-type capacitor. [Solution] A deionizing sheet for use in an electrode in a flow-through-type capacitor, which comprises active carbon fibers and is formed by a wet-mode paper making method.

Description

通液型キャパシタの電極用脱イオンシートDeionized sheet for electrode of liquid-type capacitor
 本発明は、通液型キャパシタの電極用脱イオンシート、当該脱イオンシートを用いた通液型キャパシタ、当該通液型キャパシタを備える脱イオン液製造装置、及び当該脱イオン液製造装置を用いた脱イオン液の製造方法に関する。 The present invention uses a deionized sheet for electrodes of a liquid-permeable capacitor, a liquid-permeable capacitor using the deionized sheet, a deionized liquid manufacturing apparatus including the liquid-permeable capacitor, and the deionized liquid manufacturing apparatus. The present invention relates to a method for producing a deionized liquid.
 従来、水などの液体中に含まれるイオン性物質を除去する方法として、薬品沈殿法、イオン交換法、逆浸透膜法、電気二重層の原理を利用した方法などが知られている。これらの中でも、電気二重層の原理を利用した方法では、電極での電気エネルギーの蓄電、放電を繰り返すことにより、イオン性物質の吸着・放出を行うことができるため、化学薬品を用いずに液体からイオン性物質の除去(吸着・放出)を行うことができるという利点を有する。 Conventionally, as a method for removing an ionic substance contained in a liquid such as water, a chemical precipitation method, an ion exchange method, a reverse osmosis membrane method, a method using the principle of an electric double layer, and the like are known. Among these, in the method using the principle of the electric double layer, the ionic substance can be adsorbed / released by repeatedly storing and discharging the electric energy at the electrode. It has the advantage that ionic substances can be removed (adsorbed / released).
 電気二重層の原理を利用した方法としては、セパレータを介して電極を配置した積層体からなる通液型キャパシタを用いる方法が知られている。通液型キャパシタにおいては、このような積層体にイオン性物質を含む液体を通液し、通液中に電極間に電圧を印加することにより電極表面にイオン性物質を吸着して、当該液体からイオン性物質を除去する。また、電極に吸着したイオン性物質は、無電圧または逆電圧の印加により電極表面から放出できるため、電極の再生に化学薬品を使用する必要がない。 As a method using the principle of the electric double layer, a method using a liquid-passing capacitor composed of a laminate in which electrodes are arranged via a separator is known. In a liquid-flow type capacitor, a liquid containing an ionic substance is passed through such a laminate, and a voltage is applied between the electrodes while the liquid is passed to adsorb the ionic substance on the electrode surface. To remove ionic substances from Further, since the ionic substance adsorbed on the electrode can be released from the electrode surface by applying no voltage or reverse voltage, it is not necessary to use chemicals for regeneration of the electrode.
 例えば、特許文献1には、電気絶縁性多孔質通液性シートからなるセパレータを挟んで、高比表面積活性炭を主材とする活性炭層を配置し、その活性炭層の外側に集電極を配置し、さらにその集電極の外側に押え板を配置した構成を有する平板形状の通液型電気二重層コンデンサが開示されている。特許文献1に開示された通液型電気二重層コンデンサによれば、イオン性物質の除去率が高くかつ安定しており、工業的規模での実施が可能な通液型電気二重層コンデンサが提供されることが記載されている。 For example, in Patent Document 1, an active carbon layer mainly composed of high specific surface area activated carbon is disposed with a separator made of an electrically insulating porous liquid-permeable sheet interposed therebetween, and a collector electrode is disposed outside the activated carbon layer. Furthermore, a flat plate-shaped liquid-type electric double layer capacitor having a configuration in which a holding plate is disposed outside the collector electrode is disclosed. According to the liquid passing type electric double layer capacitor disclosed in Patent Document 1, a liquid passing type electric double layer capacitor that has a high and stable removal rate of ionic substances and can be implemented on an industrial scale is provided. It is described that it is done.
 また、特許文献2には、複数の通液可能な電極と複数の通液可能なセパレータとを交互に積層した積層体を備え、前記電極は、活性炭粉末とバインダとを含む通液可能な活性炭シートを備え、前記活性炭粉末は10~500μmの中心粒子径を有し、前記バインダがフィブリル化繊維及び熱可塑性バインダ粒子から選ばれた少なくとも1種を含むことを特徴とする通液型キャパシタが開示されている。特許文献2に開示された通液型キャパシタによれば、従来の通液型キャパシタに比べて、イオン性物質の除去能力が高い通液型キャパシタが得られることが記載されている。 Further, Patent Document 2 includes a laminate in which a plurality of electrodes capable of passing liquids and a plurality of separators capable of passing liquids are alternately stacked, and the electrodes include activated carbons capable of passing liquids including activated carbon powder and a binder. Disclosed is a liquid-permeable capacitor comprising a sheet, wherein the activated carbon powder has a center particle diameter of 10 to 500 μm, and the binder includes at least one selected from fibrillated fibers and thermoplastic binder particles. Has been. According to the liquid-passing capacitor disclosed in Patent Document 2, it is described that a liquid-passing capacitor having a higher ability to remove ionic substances than a conventional liquid-passing capacitor can be obtained.
特開平6-325983号公報JP-A-6-325983 国際公開第2010/150534号パンフレットInternational Publication No. 2010/150534 Pamphlet
 従来の通液型キャパシタにおいては、例えば、特許文献1及び特許文献2などのように、積層体を構成する電極には活性炭が用いられる場合がある。しかしながら、本発明者が検討を重ねたところ、特許文献1及び特許文献2に開示されたような活性炭を用いた通液型キャパシタにおいては、単位体積当たりのイオン除去率を高めようとすると、脱イオンに供する液体の単位時間当たりの通液流量が小さくなり、イオンを除去するのに長時間が必要になる場合があることが明らかとなった。また、逆に、脱イオンに供する液体の単位時間当たりの通液流量を高めようとすると、単位体積当たりのイオン除去率が低下する場合があることが明らかとなった。このように、従来の通液型キャパシタにおいては、単位体積当たりのイオン除去率と単位時間当たりの通液流量とを共に高めることが困難となる場合があることを見出した。さらに、本発明者がさらに検討を重ねたところ、イオン除去率と通液流量とを共に高めることが困難であることは、電極に使用される脱イオンシートの構成に起因することを見出した。 In a conventional liquid-flowing capacitor, for example, activated carbon may be used for electrodes constituting the laminate as in Patent Document 1 and Patent Document 2, for example. However, as a result of repeated studies by the present inventor, in a liquid-flowing capacitor using activated carbon as disclosed in Patent Document 1 and Patent Document 2, if the ion removal rate per unit volume is to be increased, the removal is difficult. It has been clarified that the flow rate per unit time of the liquid supplied to the ions is small, and it may take a long time to remove the ions. On the contrary, it has been clarified that the ion removal rate per unit volume may decrease when the flow rate per unit time of the liquid used for deionization is increased. As described above, it has been found that it is sometimes difficult to increase both the ion removal rate per unit volume and the liquid flow rate per unit time in the conventional liquid flow type capacitor. Furthermore, as a result of further studies by the present inventors, it has been found that it is difficult to increase both the ion removal rate and the liquid flow rate due to the configuration of the deionization sheet used for the electrode.
 このような状況下、本発明は、通液型キャパシタに対して高いイオン除去率と高い通液流量とを付与し得る通液型キャパシタ用脱イオンシートを提供することを主な目的とする。さらに、本発明は、当該脱イオンシートを用いた通液型キャパシタ、当該通液型キャパシタを備える脱イオン液製造装置、及び当該脱イオン液製造装置を用いた脱イオン液の製造方法を提供することも目的とする。 Under such circumstances, a main object of the present invention is to provide a deionization sheet for a flow-through capacitor that can provide a high ion removal rate and a high flow rate to the flow-through capacitor. Furthermore, the present invention provides a liquid-permeable capacitor using the deionized sheet, a deionized liquid manufacturing apparatus including the liquid-permeable capacitor, and a method of manufacturing a deionized liquid using the deionized liquid manufacturing apparatus. Also aimed.
 本発明者は、上記のような課題を解決すべく鋭意検討を行った。その結果、活性炭繊維を含む、通液型キャパシタの電極用脱イオンシートにおいて、脱イオンシートが、湿式抄紙法により形成されたものであることにより、通液型キャパシタに対して高いイオン除去率と高い通液流量とを付与し得ることを見出した。さらに、本発明者は、このような脱イオンシートは、脱イオンに供する液体の自重によって通液型キャパシタを自然通液させる場合において、特に優れたイオン除去率及び通液流量を付与し得ることを見出した。本発明は、これらの知見に基づいて、さらに検討を重ねることにより完成された発明である。 The present inventor has intensively studied to solve the above problems. As a result, in the deionized sheet for electrodes of liquid-permeable capacitors containing activated carbon fibers, the deionized sheet is formed by a wet papermaking method, and thus has a high ion removal rate compared to liquid-permeable capacitors. It has been found that a high liquid flow rate can be provided. Further, the present inventor can provide such a deionized sheet with a particularly excellent ion removal rate and liquid flow rate when the liquid-passing capacitor is allowed to naturally flow by the dead weight of the liquid used for deionization. I found. The present invention has been completed by further studies based on these findings.
 すなわち、本発明は、下記に掲げる態様の発明を提供する。
項1. 活性炭繊維を含む、通液型キャパシタの電極用脱イオンシートであって、
 前記脱イオンシートは、湿式抄紙法により形成されたものである、通液型キャパシタの電極用脱イオンシート。
項2. 77.4Kにおける窒素吸着等温線によりDH法で求めた細孔分布において細孔直径20Å以上500Å未満の範囲のメソ細孔容積が0.002~0.8ml/gであり、かつ、全細孔容積に対する前記メソ細孔容積の割合が1~80%である、項1に記載の通液型キャパシタの電極用脱イオンシート。
項3. 前記活性炭繊維は、Mg、Mn、Fe、Y、Pt、及びGdからなる群から選択された少なくとも1種を含む、項1または2に記載の通液型キャパシタの電極用脱イオンシート。
項4. 電極とセパレータとが交互に積層された積層体を備える通液型キャパシタであって、
 前記電極は、項1~3のいずれかに記載の通液型キャパシタの電極用脱イオンシートを有する、通液型キャパシタ。
項5. 項4に記載の通液型キャパシタと、
 前記通液型キャパシタの前記電極に電気的に接続された電源と、
 前記通液型キャパシタを収容する容器と、
を備え、
 前記通液型キャパシタにおいては、前記電源の正極側が電気的に接続された前記電極と、負極側が電気的に接続された前記電極とが、前記セパレータを介して前記積層体の積層方向に交互に積層されており、
 前記容器内において、前記通液型キャパシタの積層方向の一方側から他方側に向かって、脱イオンに供される液体が通液される、脱イオン液製造装置。
項6. 前記脱イオンに供される液体の通液が、前記脱イオンに供される液体の自重により行われる、項5に記載の脱イオン液製造装置。
項7. 項5または6に記載の脱イオン液製造装置を用いる、脱イオン液の製造方法であって、
 前記通液型キャパシタの積層方向の一方側から他方側に向かって、脱イオンに供される液体を通液しながら、前記電極間に電圧を印加する、脱イオン液の製造方法。
項8. 活性炭繊維を含み、湿式抄紙法により形成されたシートの、通液型キャパシタの電極の脱イオンのための使用。
項9. 通液型キャパシタの電極用脱イオンシートとして、活性炭繊維を含み、湿式抄紙法により形成された脱イオンシートを用いる、通液型キャパシタの電極の脱イオン方法。
That is, this invention provides the invention of the aspect hung up below.
Item 1. A deionized sheet for electrodes of liquid-permeable capacitors containing activated carbon fibers,
The deionized sheet is a deionized sheet for electrodes of a liquid-permeable capacitor, which is formed by a wet papermaking method.
Item 2. In the pore distribution determined by the DH method using a nitrogen adsorption isotherm at 77.4K, the mesopore volume in the range of pore diameters of 20 mm or more and less than 500 mm is 0.002 to 0.8 ml / g, and the total pores Item 2. The deionized sheet for electrodes of a fluid-permeable capacitor according to Item 1, wherein the ratio of the mesopore volume to the volume is 1 to 80%.
Item 3. Item 3. The deionized sheet for electrodes of a liquid-permeable capacitor according to Item 1 or 2, wherein the activated carbon fiber includes at least one selected from the group consisting of Mg, Mn, Fe, Y, Pt, and Gd.
Item 4. A liquid-permeable capacitor comprising a laminate in which electrodes and separators are alternately laminated,
4. The liquid passing type capacitor, wherein the electrode has a deionizing sheet for a liquid passing type capacitor electrode according to any one of Items 1 to 3.
Item 5. Item 4. The liquid-passing capacitor according to Item 4,
A power source electrically connected to the electrode of the liquid-permeable capacitor;
A container for accommodating the liquid-flow type capacitor;
With
In the liquid passing type capacitor, the electrode to which the positive electrode side of the power source is electrically connected and the electrode to which the negative electrode side is electrically connected are alternately arranged in the stacking direction of the stacked body through the separator. Are stacked,
In the container, a deionized liquid production apparatus in which a liquid to be deionized is passed from one side to the other side in the stacking direction of the liquid passing type capacitor.
Item 6. Item 6. The deionized liquid production apparatus according to Item 5, wherein the liquid supplied to the deionization is passed by its own weight.
Item 7. A method for producing a deionized liquid using the deionized liquid production apparatus according to Item 5 or 6,
A method for producing a deionized liquid, wherein a voltage is applied between the electrodes while flowing a liquid to be used for deionization from one side to the other side in the stacking direction of the liquid-permeable capacitor.
Item 8. Use of a sheet containing activated carbon fiber and formed by a wet papermaking method for deionization of an electrode of a liquid-pass capacitor.
Item 9. A method for deionizing an electrode of a liquid-permeable capacitor using a deionized sheet containing activated carbon fibers and formed by a wet papermaking method as a deionized sheet for an electrode of a liquid-permeable capacitor.
 本発明によれば、通液型キャパシタに対して、単位体積当たりの高いイオン除去率と、単位時間当たりの高い通液流量とを付与し得る通液型キャパシタ用脱イオンシートを提供することができる。さらに、本発明によれば、当該脱イオンシートを用いた通液型キャパシタ、当該通液型キャパシタを備え、高いイオン除去率と高い通液流量とを備えた脱イオン液製造装置、及び当該脱イオン液製造装置を用いた脱イオン液の製造方法を提供することができる。 ADVANTAGE OF THE INVENTION According to this invention, the deionization sheet | seat for liquid flow type capacitors which can provide the high ion removal rate per unit volume and the high liquid flow rate per unit time with respect to a liquid flow type capacitor is provided. it can. Furthermore, according to the present invention, a liquid-permeable capacitor using the deionized sheet, a deionized liquid production apparatus including the liquid-permeable capacitor, having a high ion removal rate and a high liquid flow rate, and the desorption A method for producing a deionized liquid using an ionic liquid production apparatus can be provided.
本発明の通液型キャパシタを構成する積層体の一例(層数が9層である場合)の略図的断面図である。It is a schematic sectional drawing of an example (when the number of layers is 9 layers) which constitutes a liquid penetration type capacitor of the present invention. 本発明の脱イオン液製造装置の模式図である。It is a schematic diagram of the deionized liquid manufacturing apparatus of this invention.
 以下、本発明の通液型キャパシタ用脱イオンシート、当該脱イオンシートを用いた通液型キャパシタ、当該通液型キャパシタを備える脱イオン液製造装置、及び当該脱イオン液製造装置を用いた脱イオン液の製造方法について詳述する。 Hereinafter, a deionization sheet for a flow-through capacitor according to the present invention, a liquid-flow capacitor using the deionization sheet, a deionization liquid production apparatus including the liquid-flow capacitor, and a deionization using the deionization liquid production apparatus The manufacturing method of an ionic liquid is explained in full detail.
1.通液型キャパシタ用脱イオンシート
 本発明の通液型キャパシタ用脱イオンシートは、活性炭繊維を含む通液型キャパシタの電極用脱イオンシートであって、当該脱イオンシートが、湿式抄紙法により形成されたものであることを特徴とする。
1. Deionized sheet for liquid-permeable capacitors The deionized sheet for liquid-permeable capacitors of the present invention is a deionized sheet for electrodes of liquid-permeable capacitors containing activated carbon fibers, and the deionized sheet is formed by a wet papermaking method. It is characterized by being made.
 本発明の脱イオンシートに含まれる活性炭繊維の種類としては、例えば、ポリアクリロニトリル系、レーヨン系、フェノール樹脂系、石炭ピッチ系、石油ピッチ系等の繊維を不融化し、所望により炭化処理した後、水蒸気、二酸化炭素を含有する雰囲気中、所定温度で所定時間保持することによって賦活することにより製造される任意の活性炭繊維を採用することができる。通液型キャパシタに対して高いイオン除去率と高い通液流量とを付与する観点から、これらの中でも、石炭ピッチ、石油ピッチを原料とした活性炭繊維が好ましい。活性炭繊維は、1種類単独で使用してもよいし、2種類以上を組み合わせて使用してもよい。 Examples of the type of activated carbon fiber contained in the deionized sheet of the present invention include, for example, polyacrylonitrile-based, rayon-based, phenolic resin-based, coal pitch-based, petroleum pitch-based fibers, etc., which are infusible and optionally carbonized. Any activated carbon fiber produced by activation by holding at a predetermined temperature for a predetermined time in an atmosphere containing water vapor and carbon dioxide can be employed. Among these, activated carbon fibers using coal pitch and petroleum pitch as raw materials are preferable from the viewpoint of imparting a high ion removal rate and a high liquid flow rate to the liquid flow type capacitor. Activated carbon fiber may be used individually by 1 type, and may be used in combination of 2 or more types.
 本発明において、活性炭繊維は、77.4Kにおける窒素吸着等温線によりBJH法で求めた細孔分布において細孔直径20Å以上500Å未満の範囲のメソ細孔容積Vfmesoが0.02~0.8ml/gであり、かつ、全細孔容積に対する当該メソ細孔容積の割合Rfmesoが5~45%であることが好ましい。活性炭繊維のメソ細孔容積と、全細孔容積に対する当該メソ細孔容積の割合とが上記の範囲にあることにより、通液型キャパシタに対してより高いイオン除去率とより高い通液流量とを付与し得る。なお、「メソ細孔」とは、細孔直径が20Å以上500Å未満の細孔をいい、「ミクロ細孔」とは、細孔直径が20Å未満の細孔をいう。 In the present invention, the activated carbon fiber has a mesopore volume Vf meso of 0.02 to 0.8 ml in a pore diameter range of 20 mm or more and less than 500 mm in the pore distribution determined by the BJH method using a nitrogen adsorption isotherm at 77.4K. It is preferable that the ratio Rf meso of the mesopore volume to the total pore volume is 5 to 45%. Since the mesopore volume of the activated carbon fiber and the ratio of the mesopore volume to the total pore volume are in the above range, a higher ion removal rate and a higher liquid flow rate for the liquid passing type capacitor Can be granted. “Mesopore” refers to a pore having a pore diameter of 20 to 500 mm, and “micropore” refers to a pore having a pore diameter of less than 20 mm.
 本発明において、活性炭繊維及び通液型キャパシタ用脱イオンシートの細孔分布は、それぞれ、77.4Kにおいて窒素吸着等温線に基づいて算出されるものであり、具体的には次のようにして窒素吸着等温線が作成される。活性炭繊維または通液型キャパシタ用脱イオンシートを77.4K(窒素の沸点)に冷却し、窒素ガスを導入して容量法により窒素ガスの吸着量V[ml/g]を測定する。このとき、導入する窒素ガスの圧力P[mmHg]を徐々に上げ、窒素ガスの飽和蒸気圧P0[mmHg]で除した値を相対圧力P/P0として、各相対圧力に対する吸着量をプロットすることにより窒素吸着等温線が作成される。窒素ガスの吸着量は、市販の自動ガス吸着量測定装置(例えば、商品名「AUTOSORB-6」(QUANTCHROME製)や商品名「BELSORP-mini」(日本ベル社製)等)を用いて実施できる。本発明では、窒素吸着等温線に基づき、公知の解析方法に従って細孔分布を求めることができる。この解析は、上記装置に付属する解析プログラム等のような公知の手段を用いることができる。 In the present invention, the pore distributions of the activated carbon fiber and the deionized sheet for the liquid-flow type capacitor are respectively calculated based on the nitrogen adsorption isotherm at 77.4K, and specifically, as follows. A nitrogen adsorption isotherm is created. The activated carbon fiber or the deionized sheet for a flow-through capacitor is cooled to 77.4 K (the boiling point of nitrogen), nitrogen gas is introduced, and the adsorption amount of nitrogen gas V [ml / g] is measured by the volume method. At this time, the pressure P [mmHg] of the nitrogen gas to be introduced is gradually increased, and the value obtained by dividing by the saturated vapor pressure P 0 [mmHg] of the nitrogen gas is set as the relative pressure P / P 0 , and the adsorption amount with respect to each relative pressure is plotted. By doing so, a nitrogen adsorption isotherm is created. The adsorption amount of nitrogen gas can be carried out by using a commercially available automatic gas adsorption amount measuring device (for example, trade name “AUTOSORB-6” (manufactured by QUANTCHROME), trade name “BELSORP-mini” (manufactured by Nippon Bell Co., Ltd.), etc.) . In the present invention, the pore distribution can be obtained according to a known analysis method based on the nitrogen adsorption isotherm. For this analysis, known means such as an analysis program attached to the apparatus can be used.
 本発明において、活性炭繊維のメソ細孔容積Vfmesoは、上記の細孔分布に基づきBJH法で計算し、ミクロ細孔容積Vfmicroは上記の細孔分布に基づきt-plot法で計算する。また、後述する通液型キャパシタ用脱イオンシートのメソ細孔容積Vsmesoは、上記の細孔分布に基づきDH法で計算し、ミクロ細孔容積Vsmicroは上記の細孔分布に基づきt-plot法で計算する。BJH法は公知の方法であり、具体的には、「J.Amer.Chem.Soc.,73,373(1951))」に開示された方法が採用される。また、DH法は、具体的には、「D.Dollimore, G.R. Heal, J. Colloid Interface Sci., 33 508 (1970)」に開示された方法が採用される。 In the present invention, the mesopore volume Vf meso of the activated carbon fiber is calculated by the BJH method based on the above pore distribution, and the micropore volume Vf micro is calculated by the t-plot method based on the above pore distribution. In addition, the mesopore volume Vs meso of a deionized sheet for a flow-through capacitor to be described later is calculated by the DH method based on the above pore distribution, and the micropore volume Vs micro is t− based on the above pore distribution. Calculate by the plot method. The BJH method is a known method, and specifically, the method disclosed in “J. Amer. Chem. Soc., 73, 373 (1951))” is employed. The DH method is specifically the method disclosed in “D. Dollimore, GR Heal, J. Colloid Interface Sci., 33 508 (1970)”.
 また、本発明において、活性炭繊維の全細孔容積Vftotal及び通液型キャパシタ用脱イオンシートの全細孔容積Vstotalは、それぞれ、上記の窒素ガスの吸着量の測定結果における窒素の最大吸着量から計算することができる。活性炭繊維の全細孔容積に対する当該メソ細孔容積の割合Rfmesoは下記式(1)により、また、通液型キャパシタ用脱イオンシートの全細孔容積に対する当該メソ細孔容積の割合Rsmesoは下記式(2)により算出する。
Rfmeso=Vfmeso/Vftotal×100(%)   ・・・(1)
Rsmeso=Vsmeso/Vstotal×100(%)   ・・・(2)
In the present invention, the total pore volume Vf total of the activated carbon fiber and the total pore volume Vs total of the deionized sheet for the liquid-flow capacitor are respectively the maximum adsorption of nitrogen in the measurement results of the adsorption amount of the nitrogen gas. It can be calculated from the quantity. The ratio Rf meso of the mesopore volume with respect to the total pore volume of the activated carbon fiber is expressed by the following formula (1), and the ratio of the mesopore volume with respect to the total pore volume of the deionized sheet for a liquid-permeable capacitor Rs meso Is calculated by the following equation (2).
Rf meso = Vf meso / Vf total × 100 (%) (1)
Rs meso = Vs meso / Vs total × 100 (%) (2)
 通液型キャパシタに対して高いイオン除去率と高い通液流量とを付与する観点から、活性炭繊維のメソ細孔容積Vfmesoとしては、0.15~0.8ml/g程度であることがより好ましい。また、同様の観点から、活性炭繊維の全細孔容積に対する当該メソ細孔容積の割合Rfmesoとしては、20~80%程度がより好ましい。 From the viewpoint of imparting a high ion removal rate and a high liquid flow rate to the liquid flow type capacitor, the mesopore volume Vf meso of the activated carbon fiber is more preferably about 0.15 to 0.8 ml / g. preferable. From the same viewpoint, the ratio Rf meso of the mesopore volume to the total pore volume of the activated carbon fiber is more preferably about 20 to 80%.
 本発明において、活性炭繊維の比表面積(窒素を被吸着物質として用いたBET法(1点法)により測定される値)としては、好ましくは700~2500m2/g程度、より好ましくは1000~2000m2/g程度が挙げられる。また、活性炭繊維の全細孔容積としては0.30~1.50ml/g程度、ミクロ細孔容積としては0.25~1.30ml/g程度、メソ細孔モード直径としては5~70Å程度であることが好ましい。なお、本発明における「メソ細孔モード直径」とは、前記した細孔分布に基づきBJH法により計算される20~500Åのメソポア領域における細孔容積分布のピークが位置する細孔直径を意味する。活性炭繊維がこれらの物性を有することにより、通液型キャパシタに対してより高いイオン除去率とより高い通液流量とを付与し得る。 In the present invention, the specific surface area of the activated carbon fibers (value measured by the BET method (one-point method) using nitrogen as an adsorbed substance) is preferably about 700 to 2500 m 2 / g, more preferably 1000 to 2000 m. About 2 / g. The total pore volume of the activated carbon fiber is about 0.30 to 1.50 ml / g, the micropore volume is about 0.25 to 1.30 ml / g, and the mesopore mode diameter is about 5 to 70 mm. It is preferable that The “mesopore mode diameter” in the present invention means the pore diameter where the peak of the pore volume distribution in the mesopore region of 20 to 500 mm calculated by the BJH method based on the above pore distribution is located. . When the activated carbon fiber has these physical properties, a higher ion removal rate and a higher liquid flow rate can be imparted to the liquid passing type capacitor.
 本発明において、活性炭繊維は、Mg、Mn、Fe、Y、Pt、及びGdからなる群から選択された少なくとも1種の金属成分を含むことが好ましい。活性炭繊維は、これらの金属成分を含むことによって、特定のメソ細孔モード直径を有する活性炭繊維となり得る。例えば、含有する金属成分の種類に応じて次のような構造・特性を有する活性炭繊維となる。これらの活性炭繊維を用いることにより、通液型キャパシタに対してより高いイオン除去率とより高い通液流量とを付与し得る。 In the present invention, the activated carbon fiber preferably contains at least one metal component selected from the group consisting of Mg, Mn, Fe, Y, Pt, and Gd. The activated carbon fiber can be an activated carbon fiber having a specific mesopore mode diameter by including these metal components. For example, the activated carbon fiber has the following structure and characteristics depending on the type of the metal component contained. By using these activated carbon fibers, a higher ion removal rate and a higher liquid flow rate can be imparted to the liquid passing type capacitor.
(a)Mgを含む場合
 77.4Kにおける窒素吸着等温線よりBJH法で求めた細孔分布において細孔直径30Å以上50Å未満の範囲のメソ細孔容積が0.02~0.40ml/gであり、全細孔容積に対する上記メソ細孔容積の割合が5~45%であり、かつ、メソ細孔モード直径が30~36Åである活性炭繊維
(A) When Mg is included The mesopore volume in the pore diameter range of 30 mm or more and less than 50 mm in the pore distribution determined by the BJH method from the nitrogen adsorption isotherm at 77.4 K is 0.02 to 0.40 ml / g. Activated carbon fiber having a ratio of the mesopore volume to the total pore volume of 5 to 45% and a mesopore mode diameter of 30 to 36 mm
(b)Mn、Y、Pt、Gdの少なくとも1種を含む場合
 77.4Kにおける窒素吸着等温線よりBJH法で求めた細孔分布において細孔直径30Å以上50Å未満の範囲のメソ細孔容積が0.02~0.40ml/gであり、全細孔容積に対するメソ細孔容積の割合が5~45%であり、かつ、メソ細孔モード直径が34~40Åである活性炭繊維
(B) When containing at least one of Mn, Y, Pt, and Gd The mesopore volume in the range of pore diameters of 30 mm or more and less than 50 mm in the pore distribution determined by the BJH method from the nitrogen adsorption isotherm at 77.4K Activated carbon fiber having a mesopore volume ratio of 5 to 45% and a mesopore mode diameter of 34 to 40 mm with a total pore volume of 0.02 to 0.40 ml / g
(c)Feを含む場合
 77.4Kにおける窒素吸着等温線よりBJH法で求めた細孔分布において細孔直径30Å以上50Å未満の範囲のメソ細孔容積が0.02~0.40ml/gであり、全細孔容積に対するメソ細孔容積の割合が5~45%であり、かつ、メソ細孔モード直径が40Å~45Åである活性炭繊維
(C) When Fe is contained The mesopore volume in the pore diameter range of 30 mm or more and less than 50 mm in the pore distribution determined by the BJH method from the nitrogen adsorption isotherm at 77.4 K is 0.02 to 0.40 ml / g. And activated carbon fibers having a mesopore volume ratio of 5 to 45% with respect to the total pore volume and a mesopore mode diameter of 40 to 45 mm
 活性炭繊維の平均繊維径としては、好ましくは30μm以下、より好ましくは5~20μm程度が挙げられる。活性炭繊維の平均繊維径がこのような値を有することにより、通液型キャパシタに対してより高いイオン除去率とより高い通液流量とを付与し得る。また、活性炭繊維の平均繊維長としては、シート状に成形できれば特に制限されないが、0.5~50mm程度が好ましく、3~25mm程度がより好ましい。平均繊維長がこのような範囲にあることにより、脱イオンシートに十分な強度が付与することができ、かつ、後述の湿式抄紙法において液体中での分散性が高くなり、均一なシートを形成し易くなる。また、湿式抄紙法により形成された脱イオンシート中の活性炭繊維の繊維長としては、3mm以下が好ましい。3mm以下とするには、叩解機にて叩解することにより容易となる。なお、本発明の活性炭繊維の平均繊維径は、画像処理繊維径測定装置(JIS K 1477に準拠)により測定した値である。また、活性炭繊維の平均繊維長は、画像測定ソフト、商品名「MicroMeasure」(スカラ社製)等)を用いて測定した値である。 The average fiber diameter of the activated carbon fiber is preferably 30 μm or less, more preferably about 5 to 20 μm. When the average fiber diameter of the activated carbon fiber has such a value, a higher ion removal rate and a higher liquid flow rate can be imparted to the liquid passing type capacitor. Further, the average fiber length of the activated carbon fiber is not particularly limited as long as it can be formed into a sheet shape, but is preferably about 0.5 to 50 mm, more preferably about 3 to 25 mm. When the average fiber length is in such a range, sufficient strength can be imparted to the deionized sheet, and the dispersibility in the liquid is increased in the wet papermaking method described later, thereby forming a uniform sheet. It becomes easy to do. Further, the fiber length of the activated carbon fiber in the deionized sheet formed by the wet papermaking method is preferably 3 mm or less. In order to make it 3 mm or less, it becomes easy by beating with a beating machine. In addition, the average fiber diameter of the activated carbon fiber of the present invention is a value measured by an image processing fiber diameter measuring apparatus (based on JIS K 1477). Further, the average fiber length of the activated carbon fiber is a value measured using image measurement software, a trade name “MicroMeasure” (manufactured by SCARA), and the like.
 上記のような活性炭繊維は、公知の方法により製造することができ、例えば、特開2004-182511号公報に記載された方法により製造することができる。また、活性炭繊維の市販品としては、アドール社製のA-15などが挙げられる。 The activated carbon fiber as described above can be produced by a known method, for example, by the method described in JP-A No. 2004-182511. Examples of commercially available activated carbon fibers include A-15 manufactured by Adol.
 本発明の脱イオンシートにおける活性炭繊維の含有量としては、本発明の効果を奏することを限度として特に制限されないが、好ましくは10質量%以上、より好ましくは10~95質量%程度、さらに好ましくは45~95質量%程度が挙げられる。本発明の脱イオンシートにおける活性炭繊維の割合がこのような値を有することにより、通液型キャパシタに対してより高いイオン除去率とより高い通液流量とを付与し得る。中でも、脱イオンに供する液体の自重によって通液型キャパシタを自然通液させる場合において特に優れたイオン除去率及び通液流量を付与し得るという観点から、80~95質量%程度が特に好ましい。 The content of the activated carbon fiber in the deionized sheet of the present invention is not particularly limited as long as the effect of the present invention is achieved, but is preferably 10% by mass or more, more preferably about 10 to 95% by mass, and still more preferably. About 45 to 95% by mass. When the ratio of the activated carbon fiber in the deionized sheet of the present invention has such a value, a higher ion removal rate and a higher liquid flow rate can be imparted to the liquid passing type capacitor. In particular, about 80 to 95% by mass is particularly preferable from the viewpoint that a particularly excellent ion removal rate and liquid flow rate can be provided when the liquid-passing capacitor is naturally passed by its own weight for deionization.
 本発明の脱イオンシートは、湿式抄紙法により形成されたものである。すなわち、本発明の脱イオンシートは、上記の活性炭繊維を湿式抄紙法によりシート状に成形して得られたものである。本発明の脱イオンシートは、湿式抄紙法により形成されていることにより、従来の脱イオンシートに比して高いイオン除去率と高い通液流量とを両立できる。本発明において、このような格別な効果が奏される機序の詳細は明らかではないが、例えば次のように考えることができる。すなわち、本発明の脱イオンシートが湿式抄紙法により形成されていることにより、活性炭繊維の平均繊維長が短いものとなりやすく、かつ、活性炭繊維が均一に分布する。このため、脱イオンシートにおいて、活性炭繊維を高密度なものとしながら、通液の際にかかる抵抗の小さいシートに成形することができる。さらに、後述するバインダーを用いる場合において、バインダーの融着に起因する活性炭繊維の比表面積の低下が抑制されやすくなる。これらが作用し、単位時間当たりの通液流量の低下を抑制しつつ、単位体積当たりの高いイオン除去率が達成されているものと考えられる。以下、本発明における湿式抄紙法について、具体的に説明する。 The deionized sheet of the present invention is formed by a wet papermaking method. That is, the deionized sheet of the present invention is obtained by molding the above activated carbon fiber into a sheet by a wet papermaking method. Since the deionized sheet of the present invention is formed by a wet papermaking method, both a high ion removal rate and a high liquid flow rate can be achieved as compared with a conventional deionized sheet. In the present invention, the details of the mechanism by which such a special effect is achieved are not clear, but can be considered as follows, for example. That is, when the deionized sheet of the present invention is formed by a wet papermaking method, the average fiber length of the activated carbon fibers tends to be short, and the activated carbon fibers are uniformly distributed. For this reason, in the deionized sheet, the activated carbon fibers can be formed at a high density, and can be formed into a sheet having low resistance when passing through. Furthermore, when using the binder mentioned later, the fall of the specific surface area of the activated carbon fiber resulting from the fusion | melting of a binder becomes easy to be suppressed. These act, and it is considered that a high ion removal rate per unit volume is achieved while suppressing a decrease in the liquid flow rate per unit time. Hereinafter, the wet papermaking method in the present invention will be specifically described.
 まず、活性炭繊維を含む投入原料を液体中で分散、混合してスラリーを調製する。これにより、活性炭繊維が分散した状態となる。このとき、予め投入原料を叩解機にて叩解することが好ましい。次に、スラリーを湿式抄紙法により抄紙し、シート状に成形する。すなわち、シートの形成には、抄紙機などを用い、抄紙の要領で水中の固形分をシート状となすように固液分離する。次に、得られた湿ったシートを乾燥させることにより、本発明の脱イオンシートが得られる。活性炭繊維を分散させる液体としては、好ましくは水、アルコールなどが挙げられ、好ましくは水が挙げられる。 First, a raw material containing activated carbon fibers is dispersed and mixed in a liquid to prepare a slurry. As a result, the activated carbon fibers are dispersed. At this time, it is preferable to beat the input raw material in advance with a beater. Next, the slurry is made by a wet paper making method and formed into a sheet. That is, for the formation of the sheet, a paper machine or the like is used, and solid-liquid separation is performed so that the solid content in water is made into a sheet shape in the manner of papermaking. Next, the deionized sheet of the present invention is obtained by drying the obtained wet sheet. The liquid in which the activated carbon fiber is dispersed preferably includes water and alcohol, and preferably includes water.
 投入原料中における活性炭繊維の割合としては、スラリー中において活性炭繊維が均一に分散されれば特に制限されず、例えば10~95質量%程度が挙げられる。通液型キャパシタに対してより高いイオン除去率とより高い通液流量とを付与し得るという観点から、45~95質量%が好ましい。さらに、脱イオンに供する液体の自重によって通液型キャパシタを自然通液させる場合において特に優れたイオン除去率及び通液流量を付与し得るという観点から、80~95質量%が特に好ましい。 The ratio of the activated carbon fiber in the input raw material is not particularly limited as long as the activated carbon fiber is uniformly dispersed in the slurry, and examples thereof include about 10 to 95% by mass. From the viewpoint that a higher ion removal rate and a higher liquid flow rate can be imparted to the liquid flow type capacitor, 45 to 95% by mass is preferable. Further, in the case where the liquid-passing capacitor is naturally passed by its own weight for deionization, 80 to 95% by mass is particularly preferable from the viewpoint that a particularly excellent ion removal rate and liquid flow rate can be provided.
 活性炭繊維を含むスラリーを調製する際には、バインダーを混合することが好ましい。バインダーを混合することにより、脱イオンシートの機械的強度を高めることができる。すなわち、本発明の脱イオンシートは、バインダーを含むことが好ましい。湿式抄紙法において、バインダーを混合する場合、固液を分離した湿ったシートを形成した後、バインダーの少なくとも一部が溶融する温度以上の温度で熱処理することにより、脱イオンシートにおける活性炭繊維とバインダーとの結合を強固なものとし、バインダーの機械的強度を高めることができる。 When preparing a slurry containing activated carbon fibers, it is preferable to mix a binder. By mixing the binder, the mechanical strength of the deionized sheet can be increased. That is, the deionized sheet of the present invention preferably contains a binder. In the wet papermaking method, when the binder is mixed, after forming a wet sheet from which the solid and liquid are separated, heat treatment is performed at a temperature equal to or higher than the temperature at which at least a part of the binder melts, whereby the activated carbon fiber and binder in the deionized sheet And the mechanical strength of the binder can be increased.
 投入原料中におけるバインダーの割合としては、スラリー中において活性炭繊維が均一に分散されれば特に制限されず、例えば3~90質量%程度が挙げられる。通液型キャパシタに対してより高いイオン除去率とより高い通液流量とを付与し得るという観点から、3~50質量%が好ましい。さらに、脱イオンに供する液体の自重によって通液型キャパシタを自然通液させる場合において特に優れたイオン除去率及び通液流量を付与し得るという観点から、3~15質量%が特に好ましい。 The ratio of the binder in the input raw material is not particularly limited as long as the activated carbon fibers are uniformly dispersed in the slurry, and examples thereof include about 3 to 90% by mass. From the viewpoint that a higher ion removal rate and a higher liquid flow rate can be imparted to the liquid flow type capacitor, 3 to 50% by mass is preferable. Further, in the case where the liquid-passing capacitor is naturally passed by its own weight for deionization, 3 to 15% by mass is particularly preferable from the viewpoint of providing a particularly excellent ion removal rate and liquid flow rate.
 バインダーとしては、脱イオンシートの機械的強度を高める得るものであれば特に制限されないが、好ましくはアクリル繊維、ポリオレフィン繊維、ポリエステル繊維などのバインダー繊維が好ましい。バインダーは、1種類単独で使用してもよいし、2種類以上を組み合わせて使用してもよい。 The binder is not particularly limited as long as it can increase the mechanical strength of the deionized sheet, but binder fibers such as acrylic fibers, polyolefin fibers, and polyester fibers are preferable. A binder may be used individually by 1 type and may be used in combination of 2 or more types.
 バインダー繊維としては、好ましくは、融点または軟化点の異なる2成分以上のポリマーで形成された熱融着性の繊維が挙げられ、より好ましくは、高融点ポリマーを芯成分、低融点ポリマーを鞘成分とする芯鞘構造を有する合成繊維が挙げられる。芯鞘構造を有するバインダー繊維の具体例としては、芯部がポリプロピレンで鞘部が変性ポリエチレンにより構成された合成繊維(ポリオレフィン系複合繊維)、芯部がポリエチレンテレフタレートで鞘部がポリオレフィンにより構成されたからなる合成繊維(ポリオレフィン・ポリエステル複合繊維)、芯部がポリエチレンテレフタレートで鞘部が低融点(低軟化点)ポリエステルにより構成された合成繊維(ポリエステル系複合繊維)が挙げられる。芯鞘構造を有する合成繊維としては、市販品を使用することができ、例えば、ユニチカトレーディング株式会社からメルティーの商標で上市されているポリエステル複合繊維が好ましい。芯鞘構造を有するバインダー繊維を用いることにより、高融点ポリマーを芯成分とし、低融点ポリマーを鞘成分とするバインダー繊維とが充分に分散混合されて、両方の繊維が均一に分散して複合化した状態とすることができる。また、芯鞘構造を有するバインダー繊維を用いる際に、上記の固液分離により得られた湿ったシートをバインダー繊維の鞘成分の融点以上、芯成分の融点-20℃以下の温度で熱処理することにより、機械的強度に優れた脱イオンシートが得られる。 The binder fiber is preferably a heat-fusible fiber formed of two or more polymers having different melting points or softening points. More preferably, the high melting point polymer is a core component and the low melting point polymer is a sheath component. And synthetic fibers having a core-sheath structure. Specific examples of the binder fiber having a core-sheath structure include a synthetic fiber (polyolefin-based composite fiber) having a core part made of polypropylene and a sheath part made of modified polyethylene, a core part made of polyethylene terephthalate, and a sheath part made of polyolefin. Synthetic fiber (polyolefin-polyester composite fiber), and a synthetic fiber (polyester-based composite fiber) having a core part made of polyethylene terephthalate and a sheath part made of a low melting point (low softening point) polyester. As the synthetic fiber having a core-sheath structure, a commercially available product can be used. For example, a polyester composite fiber marketed under the trademark of Melty by Unitika Trading Co., Ltd. is preferable. By using a binder fiber having a core-sheath structure, a binder fiber having a high melting point polymer as a core component and a low melting point polymer as a sheath component is sufficiently dispersed and mixed, and both fibers are uniformly dispersed to form a composite. It can be made into the state which carried out. Further, when using a binder fiber having a core-sheath structure, the wet sheet obtained by the above solid-liquid separation is heat-treated at a temperature not lower than the melting point of the sheath component of the binder fiber and not higher than the melting point of the core component minus -20 ° C. Thus, a deionized sheet having excellent mechanical strength can be obtained.
 バインダー繊維の平均繊維長としては、好ましくは1~50mm程度、より好ましくは3~25mm程度が挙げられる。また、バインダー繊維の平均繊維径としては、好ましくは2~100μm程度、より好ましくは5~50μm程度が挙げられる。バインダー繊維の平均繊維長及び平均繊維径が、それぞれ、これらの範囲にあることにより、脱イオンシートの機械的強度を高めることができ、かつ、スラリー中での活性炭繊維とバインダー繊維との分散性を高めることができる。 The average fiber length of the binder fiber is preferably about 1 to 50 mm, more preferably about 3 to 25 mm. The average fiber diameter of the binder fiber is preferably about 2 to 100 μm, more preferably about 5 to 50 μm. When the average fiber length and average fiber diameter of the binder fiber are within these ranges, respectively, the mechanical strength of the deionized sheet can be increased, and the dispersibility of the activated carbon fiber and the binder fiber in the slurry. Can be increased.
 本発明においては、抄紙後のシートの強度を向上させるために、スラリー中に合成パルプを添加して製造することもできる。合成パルプとは、例えばポリオレフィン系、アクリル系、ポリイミド系、芳香族ポリアミド系、全芳香族ポリエステル系等の熱可塑性ポリマーからなるものや、セルロース系のパルプ状多分岐繊維である。これらの合成パルプは、液体中に分散させた場合に他材料の捕捉力が非常に強力なため、合成パルプの少量の添加で湿式抄紙法により強度の高いシートを作製することができる。合成パルプとしては、市販品を使用することができ、例えば東洋紡社からBiPULの商標で上市されているアクリル系の合成パルプが好ましい。 In the present invention, synthetic pulp can be added to the slurry to improve the strength of the sheet after papermaking. Synthetic pulp is, for example, one made of a thermoplastic polymer such as polyolefin-based, acrylic-based, polyimide-based, aromatic polyamide-based, wholly aromatic polyester-based, or cellulose-based pulp-like multibranched fiber. These synthetic pulps, when dispersed in a liquid, have a very strong trapping power for other materials, so that a high strength sheet can be produced by a wet papermaking method with a small amount of synthetic pulp added. As the synthetic pulp, commercially available products can be used. For example, an acrylic synthetic pulp marketed by Toyobo under the trademark BiPUL is preferable.
 投入原料中における合成パルプの割合としては、スラリー中において活性炭繊維が均一に分散されれば特に制限されず、例えば1~90質量%程度が挙げられる。通液型キャパシタに対してより高いイオン除去率とより高い通液流量とを付与し得るという観点から、1~50質量%が好ましい。さらに、脱イオンに供する液体の自重によって通液型キャパシタを自然通液させる場合において特に優れたイオン除去率及び通液流量を付与し得るという観点から、1~10質量%が特に好ましい。 The ratio of the synthetic pulp in the input raw material is not particularly limited as long as the activated carbon fibers are uniformly dispersed in the slurry, and examples thereof include about 1 to 90% by mass. From the viewpoint that a higher ion removal rate and a higher liquid flow rate can be imparted to the liquid flow type capacitor, 1 to 50% by mass is preferable. Further, in the case where the liquid-passing capacitor is naturally passed by its own weight for deionization, 1 to 10% by mass is particularly preferable from the viewpoint that a particularly excellent ion removal rate and liquid flow rate can be provided.
 本発明では、必要に応じて、熱処理して得られた活性炭繊維シートの密度を上げるために面圧0.1kgf/cm2以上のプレス圧力下に加熱し、次いでプレス圧力を保持した状態で冷却することも可能である。 In the present invention, if necessary, in order to increase the density of the activated carbon fiber sheet obtained by heat treatment, heating is performed under a pressing pressure of a surface pressure of 0.1 kgf / cm 2 or more, and then cooling is performed while maintaining the pressing pressure. It is also possible to do.
 スラリーを調製する際には、必要に応じて、例えば結合剤を用いることもできる。結合剤は固体成分で3質量%未満、特に1質量%未満を添加させることが好ましい。結合剤としては、例えば、結合したスルホニウム基、イソチオウロニウム基、ピリジニウム基、第四アンモニウム基、サルフェート基、スルホネート基又はカルボキシレート基を含有するアクリルポリマー又はスチレン・ブタジエンポリマーのような結合した陰イオンもしくは陽イオン電荷を有する実質的に水に不溶な有機ポリマーからなるポリマーラテックス等が挙げられる。 When preparing the slurry, for example, a binder may be used as necessary. The binder is preferably a solid component added in an amount of less than 3% by mass, particularly less than 1% by mass. The binder may be, for example, a bound anion such as an acrylic polymer or styrene-butadiene polymer containing a bound sulfonium group, isothiouronium group, pyridinium group, quaternary ammonium group, sulfate group, sulfonate group or carboxylate group. Examples thereof include polymer latex made of an organic polymer having an ionic or cationic charge and substantially insoluble in water.
 さらに、この結合剤を使用する方法では、有機凝集剤を併用することが好ましい。適当な有機凝集剤としては、アルミニウム・ポリクロリド(アルミニウム・ヒドロオキシクロリド)、一部加水分解したポリアクリルアミド、変性陽イオンポリアクリルアミド、ジアリルジエチルアンモニウムクロリド等の種々の有機凝集剤が挙げられる。この凝集剤の添加量はシートの3質量%未満、好ましくは1質量%未満である。また、分散性を向上させるために、例えばキサンタンガム等のスラリー粘度調整剤を用いることもできる。このような増粘剤の添加量は、活性炭繊維シートの2質量%未満であることが好ましい。 Furthermore, in the method using this binder, it is preferable to use an organic flocculant in combination. Suitable organic flocculants include various organic flocculants such as aluminum polychloride (aluminum hydroxychloride), partially hydrolyzed polyacrylamide, modified cationic polyacrylamide, diallyl diethylammonium chloride and the like. The amount of the flocculant added is less than 3% by mass of the sheet, preferably less than 1% by mass. Moreover, in order to improve dispersibility, slurry viscosity modifiers, such as a xanthan gum, can also be used, for example. It is preferable that the addition amount of such a thickener is less than 2 mass% of the activated carbon fiber sheet.
 本発明の脱イオンシートは、77.4Kにおける窒素吸着等温線によりDH法で求めた細孔分布において細孔直径20Å以上500Å未満の範囲のメソ細孔容積Vsmesoが0.002~0.8ml/gであり、かつ、全細孔容積に対する前記メソ細孔容積の割合Rsmesoが1~80%であることが好ましい。本発明においては、脱イオンシートがこれらの物性値を有することにより、通液型キャパシタに対してより高いイオン除去率とより高い通液流量とを付与し得る。なお、本発明の脱イオンシートのメソ細孔容積Vsmeso、ミクロ細孔容積Vsmicro、全細孔容積に対する当該メソ細孔容積の割合Rsmesoは、それぞれ、前述した方法により測定される値である。 The deionized sheet of the present invention has a mesopore volume Vs meso in the range of pore diameters of 20 mm or more and less than 500 mm in the pore distribution determined by the DH method using a nitrogen adsorption isotherm at 77.4 K of 0.002 to 0.8 ml. It is preferable that the ratio Rs meso of the mesopore volume to the total pore volume is 1 to 80%. In the present invention, when the deionization sheet has these physical property values, a higher ion removal rate and a higher liquid flow rate can be imparted to the liquid flow type capacitor. The mesopore volume Vs meso , the micropore volume Vs micro , and the ratio Rs meso of the mesopore volume to the total pore volume of the deionized sheet of the present invention are values measured by the method described above. is there.
 通液型キャパシタに対してさらに高いイオン除去率及び通液流量を付与する観点から、脱イオンシートのメソ細孔容積Vsmesoとしては、0.15~0.8ml/g程度であることがより好ましい。また、同様の観点から、全細孔容積に対する当該メソ細孔容積の割合としては、20~80%程度がより好ましい。 From the viewpoint of imparting a higher ion removal rate and liquid flow rate to the liquid flow type capacitor, the mesopore volume Vs meso of the deionized sheet is more preferably about 0.15 to 0.8 ml / g. preferable. From the same viewpoint, the ratio of the mesopore volume to the total pore volume is more preferably about 20 to 80%.
 同様の観点から、本発明の脱イオンシートは、以下の物性を有することが好ましい。ミクロ細孔容積としては、好ましくは0.2~1.30ml/g程度、より好ましくは0.5~1.30ml/g程度である。全細孔容積としては、好ましくは0.5~1.50ml/g程度、より好ましくは0.7~1.50ml/g程度である。比表面積(窒素を被吸着物質として用いたBET法(1点法)により測定される値)としては、好ましくは700~2500m2/g程度、より好ましくは1000~2500m2/g程度である。 From the same viewpoint, the deionized sheet of the present invention preferably has the following physical properties. The micropore volume is preferably about 0.2 to 1.30 ml / g, more preferably about 0.5 to 1.30 ml / g. The total pore volume is preferably about 0.5 to 1.50 ml / g, more preferably about 0.7 to 1.50 ml / g. The specific surface area (value measured by the BET method (one-point method) using nitrogen as an adsorbed substance) is preferably about 700 to 2500 m 2 / g, more preferably about 1000 to 2500 m 2 / g.
 本発明の脱イオンシートの厚みとしては、好ましくは0.2~1.2mm程度、より好ましくは0.5~0.9mm程度が挙げられる。脱イオンシートの厚みがこのような範囲にあることにより、通液型キャパシタに対してより高いイオン除去率及び通液流量を付与し得る。 The thickness of the deionized sheet of the present invention is preferably about 0.2 to 1.2 mm, more preferably about 0.5 to 0.9 mm. When the thickness of the deionized sheet is in such a range, a higher ion removal rate and liquid flow rate can be imparted to the liquid flow type capacitor.
 本発明の脱イオンシートを通液型キャパシタとして用いる場合、上記脱イオンシートを厚み方向に対して加圧し圧縮することが好ましく、圧縮後の厚みとしては0.35~0.60mm程度、より好ましくは0.40~0.55mm程度が挙げられる。脱イオンシートの厚みがこのような範囲にあることにより、通液型キャパシタに対して特に高いイオン除去率及び通液流量を付与し得る。 When the deionized sheet of the present invention is used as a liquid-type capacitor, the deionized sheet is preferably pressed and compressed in the thickness direction, and the thickness after compression is preferably about 0.35 to 0.60 mm. Is about 0.40 to 0.55 mm. When the thickness of the deionized sheet is in such a range, a particularly high ion removal rate and liquid flow rate can be imparted to the liquid flow type capacitor.
 また、本発明の脱イオンシートの目付としては、好ましくは30~200g/m2程度、より好ましくは30~130g/m2程度、さらに好ましくは70~90g/m2程度が挙げられる。脱イオンシートの目付がこのような範囲にあることにより、通液型キャパシタに対してより高いイオン除去率及び通液流量を付与し得る。 The basis weight of the deionized sheet of the present invention is preferably about 30 to 200 g / m 2 , more preferably about 30 to 130 g / m 2 , and still more preferably about 70 to 90 g / m 2 . When the basis weight of the deionized sheet is in such a range, a higher ion removal rate and liquid flow rate can be provided to the liquid flow type capacitor.
 後述の通り、本発明の湿式抄紙法により形成された脱イオンシートは、通液型キャパシタ(脱イオン液製造装置)に用いられた場合に、驚くべきことに、脱イオンに供される液体の自重によって自然通液されることにより、特に優れたイオン除去率と通液流量とを発揮することができる。 As will be described later, when the deionized sheet formed by the wet papermaking method of the present invention is used in a liquid-passing capacitor (deionized liquid production apparatus), it is surprising that the liquid used for deionization By being naturally passed by its own weight, a particularly excellent ion removal rate and liquid flow rate can be exhibited.
 本発明の脱イオンシートは、例えば、通液型キャパシタ、これを備える脱イオン液製造装置に好適に使用することができ、例えば後述のような通液型キャパシタ、脱イオン液製造装置などに適用することができる。 The deionized sheet of the present invention can be suitably used for, for example, a liquid-permeable capacitor and a deionized liquid manufacturing apparatus including the same. can do.
2.通液型キャパシタ
 本発明の通液型キャパシタは、上記の本発明の脱イオンシートを用いたものである。具体的には、本発明の通液型キャパシタは、電極とセパレータとが交互に積層された積層体を備えており、当該電極が、上記の脱イオンシートを有している。
2. Liquid-permeable capacitor The liquid-permeable capacitor of the present invention uses the above-described deionized sheet of the present invention. Specifically, the liquid-permeable capacitor of the present invention includes a laminate in which electrodes and separators are alternately laminated, and the electrodes have the deionized sheet.
 本発明の通液型キャパシタにおいて、電極としては、上記の脱イオンシートを有していれば特に制限されないが、高いイオン除去率及び通液流量を発揮させる観点からは、好ましくは集電極を備えていることが好ましい。 In the liquid-passing capacitor of the present invention, the electrode is not particularly limited as long as it has the above deionization sheet. However, from the viewpoint of exhibiting a high ion removal rate and liquid flow rate, the electrode preferably includes a collecting electrode. It is preferable.
 本発明の通液型キャパシタの積層構造について、図1の略図的断面図を用いて説明する。図1に示される積層体1において、電極2とセパレータ3とが交互に積層されている。電極2において、脱イオンシート21は、集電極22の上に形成されている。複数の脱イオンシート21の間には、絶縁性のセパレータ3が配置されている。通液型キャパシタを構成する積層体1は、図1に示すように、電極2(集電極21/脱イオンシート22)/セパレータ3/電極2(脱イオンシート21/集電極22)という積層構造を最小単位としており、図1においては、このような積層構造が連続して2つ形成されている(集電極、脱イオンシート、及びセパレータの合計層数が9層)である場合について示されている。 The laminated structure of the liquid-permeable capacitor of the present invention will be described with reference to the schematic cross-sectional view of FIG. In the laminate 1 shown in FIG. 1, the electrodes 2 and the separators 3 are alternately laminated. In the electrode 2, the deionized sheet 21 is formed on the collector electrode 22. An insulating separator 3 is disposed between the plurality of deionized sheets 21. As shown in FIG. 1, the laminated body 1 constituting the liquid-permeable capacitor has a laminated structure of electrode 2 (collector electrode 21 / deionized sheet 22) / separator 3 / electrode 2 (deionized sheet 21 / collector electrode 22). FIG. 1 shows a case where two such laminated structures are continuously formed (the total number of collector electrodes, deionized sheets, and separators is nine). ing.
 集電極としては、導電性材料により構成されていれば特に制限されず、例えば、銅板、アルミニウム板、カーボン板、フォイル状グラファイトなど、上記の脱イオンシートと密着可能なものを用いることができる。なお、集電極に通液性を付与するために、集電極に通液孔を設けてもよい。集電極の厚みとしては、好ましくは0.01~1mm程度、より好ましくは0.02~0.5mm程度が挙げられる。なお、電極間の印加を容易にするため、後述の脱イオン製造装置において、集電極に端子(リード)を設けることが好ましい。 The collector electrode is not particularly limited as long as it is made of a conductive material, and for example, a copper plate, an aluminum plate, a carbon plate, foil-like graphite, or the like that can be in close contact with the deionized sheet can be used. In order to impart liquid permeability to the collector electrode, a liquid passage hole may be provided in the collector electrode. The thickness of the collector electrode is preferably about 0.01 to 1 mm, more preferably about 0.02 to 0.5 mm. In addition, in order to make the application between electrodes easy, it is preferable to provide a terminal (lead) on the collecting electrode in a deionization manufacturing apparatus described later.
 セパレータとしては、通液性及び絶縁性を有するものであれば特に制限されず、例えば、ろ紙、不織布などが挙げられる。また、セパレータの厚みとしては、好ましくは30~300μm程度、より好ましくは50~250μm程度が挙げられる。なお、本発明の通液型キャパシタにおいては、脱イオンシート、セパレータ、集電極以外の層を1層以上有していてもよい。 The separator is not particularly limited as long as it has liquid permeability and insulating properties, and examples thereof include filter paper and nonwoven fabric. The thickness of the separator is preferably about 30 to 300 μm, more preferably about 50 to 250 μm. In addition, in the liquid-permeable capacitor of this invention, you may have one or more layers other than a deionization sheet | seat, a separator, and a collector electrode.
 本発明の通液型キャパシタにおいて、脱イオンシート、セパレータ、集電極などの積層体を構成する層の合計層数としては、目的とする通液型キャパシタの大きさ、単位体積当たりのイオン除去性能、及び単位時間当たりの通液流量に応じて適宜設定することができ、例えば10層以上、好ましくは40~100層程度が挙げられる。 In the liquid-permeable capacitor of the present invention, the total number of layers constituting the laminate such as a deionized sheet, a separator, and a collector electrode is the size of the target liquid-permeable capacitor and the ion removal performance per unit volume. , And the flow rate per unit time can be appropriately set. For example, 10 layers or more, preferably about 40 to 100 layers can be mentioned.
 本発明の通液型キャパシタを構成する積層体の高さ(積層方向における厚み)は、目的とする通液型キャパシタの大きさ、イオン除去性能、及び単位時間当たりの通液流量に応じて適宜設定することができ、コンパクト化、イオン除去性能、及び単位時間当たりの通液流量のいずれも向上させる観点から、例えば5mm以上、好ましくは20~50mm程度が挙げられる。当該積層体の高さは、一般に、積層体を構成する層数及び各層の厚みの増加により高くなるが、積層体の積層方向に圧力を加えることによって、高さを調整することができる。積層体に加える圧力が大きいほど、積層体の高さは低くなり、積層体の密度は高くなるため、単位体積当たりのイオン除去率を高めることができるが、単位時間当たりの通液流量は低下する。 The height (thickness in the stacking direction) of the laminated body constituting the liquid-permeable capacitor of the present invention is appropriately determined according to the size of the target liquid-permeable capacitor, the ion removal performance, and the liquid flow rate per unit time. From the viewpoint of improving the compactness, ion removal performance, and flow rate per unit time, for example, 5 mm or more, preferably about 20 to 50 mm can be mentioned. The height of the laminate is generally increased by increasing the number of layers constituting the laminate and the thickness of each layer, but the height can be adjusted by applying pressure in the stacking direction of the laminate. The higher the pressure applied to the laminate, the lower the height of the laminate and the higher the density of the laminate, so that the ion removal rate per unit volume can be increased, but the flow rate per unit time decreases. To do.
 本発明の通液型キャパシタにおいて、積層体の高さ方向に対して垂直方向の断面積は、目的とする通液型キャパシタの大きさ、イオン除去性能、及び単位時間当たりの通液流量に応じて適宜設定することができるが、コンパクト化、イオン除去性能、及び単位時間当たりの通液流量のいずれも向上させる観点から、1000~5000cm2が好ましい。本発明の通液型キャパシタは、脱イオンシートが湿式抄紙法により形成されたものであるため、通液型キャパシタをコンパクトなものとしても、単位時間当たりの通液流量の低下を抑制しつつ、単位体積当たりの高いイオン除去率が達成することができる。また、コンパクト化を図ることにより、例えばポット型浄水器とした場合に家庭用の冷蔵庫への収納にも対応可能となる。 In the liquid-permeable capacitor of the present invention, the cross-sectional area in the direction perpendicular to the height direction of the multilayer body depends on the size of the target liquid-permeable capacitor, the ion removal performance, and the liquid flow rate per unit time. However, from the viewpoint of improving compactness, ion removal performance, and liquid flow rate per unit time, 1000 to 5000 cm 2 is preferable. Since the liquid-passing capacitor of the present invention is a deionized sheet formed by a wet papermaking method, even if the liquid-passing capacitor is compact, while suppressing a decrease in the liquid flow rate per unit time, A high ion removal rate per unit volume can be achieved. Further, by making it compact, for example, when it is a pot type water purifier, it can be accommodated in a household refrigerator.
 本発明の通液型キャパシタは、脱イオン液製造装置に好適に使用することができ、例えば後述のような脱イオン液製造装置などに適用することができる。 The liquid-permeable capacitor of the present invention can be suitably used in a deionized liquid production apparatus, and can be applied to a deionized liquid production apparatus as described below, for example.
3.脱イオン液製造装置
 本発明の脱イオン液製造装置は、上記の本発明の通液型キャパシタを備えている。具体的には、本発明の脱イオン液製造装置は、上記の通液型キャパシタと、電源と、容器とを備えている。電源は、通液型キャパシタの上記電極に電気的に接続されている。通液型キャパシタにおいて、電源の正極側が電気的に接続された電極と、負極側が電気的に接続された電極とが、セパレータを介して積層体の積層方向に交互に積層されている。また、容器は、通液型キャパシタを収容している。当該容器内において、通液型キャパシタの積層方向の一方側から他方側に向かって、脱イオンに供される液体が通液される。本発明の脱イオン液製造装置の模式図を図3に示す。
3. Deionized liquid manufacturing apparatus The deionized liquid manufacturing apparatus of the present invention includes the above-described liquid passing type capacitor of the present invention. Specifically, a deionized liquid production apparatus of the present invention includes the above-described liquid-flowing capacitor, a power source, and a container. The power source is electrically connected to the electrode of the liquid-pass capacitor. In the liquid-permeable type capacitor, the electrode electrically connected to the positive electrode side of the power source and the electrode electrically connected to the negative electrode side are alternately stacked in the stacking direction of the stacked body through the separator. Further, the container contains a liquid passing type capacitor. In the container, a liquid to be used for deionization is passed from one side in the stacking direction of the liquid passing type capacitor toward the other side. A schematic diagram of the deionized liquid production apparatus of the present invention is shown in FIG.
 本発明の脱イオン液製造装置において、容器の大きさ及び形状としては、上記の通液型キャパシタを収容できれば特に制限されないが、通液型キャパシタの全ての電極間に脱イオンに供される液体が通液されるために、容器は、積層方向において通液型キャパシタの形状に沿った内部空間を有することが好ましい。 In the deionized liquid production apparatus of the present invention, the size and shape of the container are not particularly limited as long as the above-described liquid-permeable capacitor can be accommodated, but the liquid used for deionization between all the electrodes of the liquid-permeable capacitor Therefore, the container preferably has an internal space along the shape of the liquid-permeable capacitor in the stacking direction.
 本発明の脱イオン液製造装置においては、脱イオンに供される液体の通液は、ポンプなどで通液流量を一定に制御してもよいし、当該液体の自重による自然通液で行ってもよいが、自然通液により行うことが特に好ましい。本発明の脱イオン液製造装置においては、驚くべきことに、自然通液を行うことにより、より高いイオン除去率及び通液流量を発揮させることが可能となる。自然通液によって、より高いイオン除去率及び通液流量を発揮させることが可能となる理由は不明であるが、本発明の脱イオンシートが湿式抄紙法により形成されていることと関連しているものと考えられる。 In the deionized liquid production apparatus of the present invention, the flow of the liquid to be used for deionization may be controlled by a pump or the like so that the flow rate of the liquid is constant, or may be performed by natural flow by the weight of the liquid. However, it is particularly preferable to carry out by natural liquid passage. Surprisingly, in the deionized liquid production apparatus of the present invention, it is possible to exhibit a higher ion removal rate and liquid flow rate by performing natural liquid flow. The reason why a higher ion removal rate and liquid flow rate can be exhibited by natural liquid flow is unknown, but it is related to the fact that the deionized sheet of the present invention is formed by a wet papermaking method. It is considered a thing.
 本発明の脱イオン液製造装置において、通液型キャパシタの積層方向に対し垂直な断面の断面積が2500cm2である場合に、単位時間当たりの通液流量(ml/分)としては、好ましくは20ml/分以上、より好ましくは50~120ml/分程度が挙げられる。なお、自然通液により行った場合には、当該通液量は、通液開始から通液完了までの平均値である。 In the deionized liquid production apparatus of the present invention, when the cross-sectional area of the cross section perpendicular to the laminating direction of the liquid-permeable capacitor is 2500 cm 2 , the liquid flow rate (ml / min) per unit time is preferably 20 ml / min or more, more preferably about 50 to 120 ml / min. In addition, when it carries out by natural liquid flow, the said liquid flow amount is an average value from the liquid flow start to the completion of liquid flow.
 脱イオンに供される液体としては、イオンを含む液体であれば特に制限されず、例えば、水、海水、廃液などが挙げられ、これらの中でも水道水、硬水などの水が挙げられる。また、除去されるイオン性物質としても、特に制限されず、金属塩、アミン塩、アンモニウム塩、無機酸、有機酸などの液体中でイオンに解離可能な電解質などが挙げられる。本発明の脱イオン液製造装置は、5~600ppm程度の金属イオンなどを含む硬水の脱イオン水の製造方法として特に好適に使用することができる。 The liquid subjected to deionization is not particularly limited as long as it is a liquid containing ions, and examples thereof include water, seawater, waste liquid, and the like. Among these, water such as tap water and hard water is exemplified. Further, the ionic substance to be removed is not particularly limited, and examples thereof include an electrolyte that can dissociate into ions in a liquid such as a metal salt, an amine salt, an ammonium salt, an inorganic acid, or an organic acid. The deionized liquid production apparatus of the present invention can be particularly suitably used as a method for producing deionized water of hard water containing about 5 to 600 ppm of metal ions.
 本発明の脱イオン液製造装置において、脱イオンに供される液体の通液が脱イオンに供される液体の自重により行われる場合、CaCl2及びMgCl2を用い、Mg2+:Ca2+=3:1(重量比)となるようにして、下記の式(3)で算出される硬度成分となるイオン濃度が100ppmの硬水を用い、単位時間当たりの通液流量(ml/分)が100ml/分となるように通液をおこない、1.5Vの電圧を印加したときのイオン除去率が75%以上であることが好ましい。これにより、例えば1Lの硬水を短時間で効率的に軟水化することが可能となり、一般家庭で用いられるポット型浄水器として特に適したものとすることができる。上記通液流量及びイオン除去率とするためには、脱イオンシートが湿式抄紙法により形成されたものであることのほか、活性炭繊維の細孔分布、比表面積、平均繊維長、平均繊維径及び含有量、バインダー及び/または合成パルプの含有量、脱イオンシートの厚み及び目付、脱イオンシート、セパレータ、集電極などの積層体を構成する層の合計層数、通液型キャパシタを構成する積層体の高さ等を適宜調整することにより可能となる。
硬度(ppm)=Ca2+(ppm)×2.5+Mg2+(ppm)×4.1   (3)
In the deionized liquid production apparatus of the present invention, when the flow of the liquid used for deionization is performed by the weight of the liquid used for deionization, CaCl 2 and MgCl 2 are used, and Mg 2+ : Ca 2+ = 3: 1 (weight ratio), using hard water having an ion concentration of 100 ppm as a hardness component calculated by the following formula (3), and the flow rate per unit time (ml / min) is It is preferable that the ion removal rate is 75% or more when the liquid is passed at 100 ml / min and a voltage of 1.5 V is applied. As a result, for example, 1 L of hard water can be softened efficiently in a short time, and can be particularly suitable as a pot-type water purifier used in general households. In order to obtain the liquid flow rate and the ion removal rate, in addition to the deionized sheet formed by a wet papermaking method, the pore distribution of the activated carbon fiber, the specific surface area, the average fiber length, the average fiber diameter and Content, content of binder and / or synthetic pulp, thickness and basis weight of deionized sheet, total number of layers constituting laminate such as deionized sheet, separator, collector electrode, lamination constituting liquid-permeable capacitor This can be achieved by appropriately adjusting the height of the body.
Hardness (ppm) = Ca 2+ (ppm) × 2.5 + Mg 2+ (ppm) × 4.1 (3)
 4.脱イオン液の製造方法
 本発明の脱イオン液の製造方法は、上記の本発明の脱イオン液製造装置を用いて行うことができる。すなわち、脱イオン液製造装置に備え付けられた通液型キャパシタの積層方向の一方側から他方側に向かって、脱イオンに供される液体を通液しながら、通液型キャパシタの電極間に電圧を印加する。これにより、通液中の液体に含まれるカチオンはアノード側の電極に吸着され、アニオンはカソード側に吸着され、液体からイオン性物質が除去されて、脱イオン液が製造される。電極間に印加する電圧としては、特に制限されないが、例えば0.5~5V程度が挙げられる。電極間に電圧を印可する方法としては、セパレータを介して積層体の積層方向に交互に積層されている電極において、互いに対向する電極の一方側には電源の正極、他方側には電源の負極をそれぞれ電気的に接続して行うことができる。また、電極に吸着したイオン性物質は、無電圧または逆電圧の印加により電極表面から放出できる。このため、電極に吸着したイオン性物質は、高濃度のイオン性物質を含む液体として排出することができる。
4). Method for Producing Deionized Liquid The method for producing a deionized liquid of the present invention can be performed using the above-described deionized liquid manufacturing apparatus of the present invention. That is, the voltage between the electrodes of the flow-through capacitor is passed while flowing the liquid used for deionization from one side to the other side in the stacking direction of the flow-through capacitor provided in the deionized liquid production apparatus. Apply. As a result, cations contained in the liquid being passed are adsorbed on the anode side electrode, anions are adsorbed on the cathode side, ionic substances are removed from the liquid, and a deionized liquid is produced. The voltage applied between the electrodes is not particularly limited, and for example, about 0.5 to 5 V can be mentioned. As a method of applying a voltage between the electrodes, in the electrodes stacked alternately in the stacking direction of the stacked body through the separator, the positive electrode of the power supply is on one side of the electrodes facing each other, and the negative electrode of the power supply is on the other side Can be electrically connected to each other. The ionic substance adsorbed on the electrode can be released from the electrode surface by applying no voltage or reverse voltage. For this reason, the ionic substance adsorbed on the electrode can be discharged as a liquid containing a high concentration of ionic substance.
 以下に、実施例及び比較例を示して本発明を詳細に説明する。ただし、本発明は、実施例に限定されない。 Hereinafter, the present invention will be described in detail with reference to Examples and Comparative Examples. However, the present invention is not limited to the examples.
 (実施例1)
 以下の湿式抄紙法により、脱イオンシートを作製した。活性炭繊維(アドール社製のA-15)87質量部と、バインダーとして鞘部の軟化点が80℃、芯部の融点が250℃の芯鞘構造のポリエステル複合繊維(メルティー4080、2.2dtex×5mm、ユニチカ社製)10質量部と、合成パルプとしてアクリル繊維(BiPUL、東洋紡社製)3質量部を、叩解機を用いて水中で混合、せん断し、均一に分散した水性スラリーを調製した。次に、得られた水性スラリーを所定の流量でワイヤー上に流して水中の固形分をシート状とし、その後、プレスパートを経てドライヤーパートでシートを乾燥した。さらに、カレンダーパートでシート表面を平滑にしてからリールで巻き取り、脱イオンシートを得た。
(Example 1)
A deionized sheet was prepared by the following wet papermaking method. 87 parts by mass of activated carbon fiber (A-15 manufactured by Adol) and a polyester-composite fiber (Melty 4080, 2.2 dtex ×) having a core-sheath structure in which the softening point of the sheath is 80 ° C. and the melting point of the core is 250 ° C. An aqueous slurry in which 10 parts by mass of 5 mm (manufactured by Unitika) and 3 parts by mass of acrylic fiber (BiPUL, manufactured by Toyobo Co., Ltd.) as synthetic pulp was mixed and sheared in water using a beating machine to prepare a uniformly dispersed aqueous slurry. Next, the obtained aqueous slurry was flowed on a wire at a predetermined flow rate to form a solid content in water into a sheet, and then the sheet was dried by a dryer part through a press part. Further, the surface of the sheet was smoothed with a calendar part and wound up with a reel to obtain a deionized sheet.
 なお、実施例1で用いた活性炭繊維の比表面積は、比表面積1730m2/gであった。当該比表面積は、窒素を被吸着物質として用いたBET法(1点法)で測定した。活性炭繊維の窒素ガス吸着量は、商品名「AUTOSORB-6」(QUANTCHROME製)を用いて測定した。細孔分布の解析は、付属の解析プログラムで実施した。また、活性炭繊維の全細孔容積Vftotalは、0.81ml/gであった。当該全細孔容積は、窒素の最大吸着量から計算した。 The specific surface area of the activated carbon fiber used in Example 1 was a specific surface area of 1730 m 2 / g. The specific surface area was measured by the BET method (one-point method) using nitrogen as an adsorbed substance. The nitrogen gas adsorption amount of the activated carbon fiber was measured using a trade name “AUTOSORB-6” (manufactured by QUANTCHROME). The analysis of the pore distribution was carried out with the attached analysis program. Moreover, the total pore volume Vf total of the activated carbon fiber was 0.81 ml / g. The total pore volume was calculated from the maximum adsorption amount of nitrogen.
 また、実施例1で得られた脱イオンシートの目付(g/m2)、厚み、活性炭繊維の割合(質量%)、比表面積(m2/g)、ミクロ細孔容積Vsmicro(ml/g)、メソ細孔容積Vsmeso(ml/g)、全細孔容積Vstotal(ml/g)、全細孔容積に対する前記メソ細孔容積の割合Rsmeso(%)を表1に示す。なお、脱イオンシートの比表面積(m2/g)、ミクロ細孔容積(ml/g)、メソ細孔容積(ml/g)、全細孔容積(ml/g)は、商品名「BELSORP-mini」(日本ベル社製)を用いて、窒素ガス吸着量を測定し、比表面積はBET法、ミクロ細孔容積Vsmicroはt-plot法、メソ細孔容積VsmesoはDH法、全細孔容積Vstotalは窒素の最大吸着量より算出した値である。また、得られた脱イオンシート中の活性炭繊維の最大繊維長は2mmであった(すなわち、脱イオンシート中の活性炭繊維の繊維長は3mm以下であった)。 Further, the basis weight (g / m 2 ), thickness, ratio of activated carbon fibers (mass%), specific surface area (m 2 / g), micropore volume Vs micro (ml / m) of the deionized sheet obtained in Example 1 Table 1 shows g), mesopore volume Vs meso (ml / g), total pore volume Vs total (ml / g), and the ratio Rs meso (%) of the mesopore volume to the total pore volume. The specific surface area (m 2 / g), micropore volume (ml / g), mesopore volume (ml / g), and total pore volume (ml / g) of the deionized sheet are trade names “BELSORP”. -Mini "(manufactured by Nippon Bell Co., Ltd.), the nitrogen gas adsorption amount is measured, the specific surface area is the BET method, the micropore volume Vs micro is the t-plot method, the mesopore volume Vs meso is the DH method, the total The pore volume Vs total is a value calculated from the maximum adsorption amount of nitrogen. Moreover, the maximum fiber length of the activated carbon fiber in the obtained deionized sheet was 2 mm (that is, the fiber length of the activated carbon fiber in the deionized sheet was 3 mm or less).
 上記で得られた脱イオンシート、セパレータ(アドバンテック社製のろ紙No.5C、厚さ0.22mm)、及びタブを設けた集電極(グラファイトフォイルシート、東洋炭素社製のPERMA-FOIL、厚さ0.05mm)をそれぞれ外径82mm及び内径25mmのリング状に切り出し、該集電極、該脱イオンシート、該セパレータ、該脱イオンシート、該集電極の順に合計54層となるように積層して積層体(通液型キャパシタ)を得た。なお、積層体に対して、およそ5MPaの圧力を積層方向に加えることにより、積層体の高さを25mmに調整した。次に、得られた積層体を、外径140mm、内径125mm、高さ110mmの塩化ビニル樹脂製の円筒型容器に充填し、電源の負極側と正極側とが交互になるようにして、集電極のタブに電極端子を接続して、通液型キャパシタを備える脱イオン液製造装置とした。 Deionized sheet obtained above, separator (filter paper No. 5C manufactured by Advantech, thickness 0.22 mm), and collector electrode provided with a tab (graphite foil sheet, PERMA-FOIL manufactured by Toyo Tanso Co., Ltd., thickness 0.05mm) is cut into a ring shape having an outer diameter of 82 mm and an inner diameter of 25 mm, respectively, and the collector electrode, the deionized sheet, the separator, the deionized sheet, and the collector electrode are laminated in this order so that there are a total of 54 layers. A laminate (liquid-passing type capacitor) was obtained. In addition, the height of the laminated body was adjusted to 25 mm by applying a pressure of about 5 MPa to the laminated body in the lamination direction. Next, the obtained laminate is filled into a vinyl chloride resin cylindrical container having an outer diameter of 140 mm, an inner diameter of 125 mm, and a height of 110 mm, and the negative electrode side and the positive electrode side of the power source are alternately arranged. An electrode terminal was connected to the tab of the electrode to obtain a deionized liquid production apparatus equipped with a liquid passing type capacitor.
 次に、脱イオンに供する硬水を以下の手順により調製した。CaCl2及びMgCl2を用い、Mg2+:Ca2+=3:1(重量比)となるようにして、下記の式(3)で算出される硬度成分となるイオン濃度が100ppmの硬水を調製した。
硬度(ppm)=Ca2+(ppm)×2.5+Mg2+(ppm)×4.1   (3)
Next, hard water used for deionization was prepared by the following procedure. Using CaCl 2 and MgCl 2 , hard water having an ion concentration of 100 ppm as a hardness component calculated by the following formula (3) is set so that Mg 2+ : Ca 2+ = 3: 1 (weight ratio). Prepared.
Hardness (ppm) = Ca 2+ (ppm) × 2.5 + Mg 2+ (ppm) × 4.1 (3)
 次に、上記の脱イオン液製造装置の容器の上に給水用タンク(容積2L)を取り付け、給水用タンク内に上記の硬水を1L充填し、硬水の自重により通液型キャパシタ内を自然通水させた。全ての硬水が通水されるまでの通水流量の平均は、100ml/分であった。なお、硬水を通水させている間、各電極には1.5Vの電圧を印加した。通液型キャパシタを通過した処理水の電気伝導度を測定し、脱イオン対象とした硬水の電気伝導度と当該処理水の電気伝導度から、硬水からのイオン除去率を求めた。結果を表2に示す。 Next, a water supply tank (volume 2 L) is mounted on the container of the deionized liquid production apparatus, 1 L of the hard water is filled in the water supply tank, and the liquid-passing capacitor is naturally passed by its own weight. Made it water. The average flow rate until all hard water was passed was 100 ml / min. Note that a voltage of 1.5 V was applied to each electrode while passing the hard water. The electrical conductivity of the treated water that passed through the liquid-type capacitor was measured, and the ion removal rate from the hard water was determined from the electrical conductivity of the hard water targeted for deionization and the electrical conductivity of the treated water. The results are shown in Table 2.
 (比較例1)
 脱イオンシートとして、群栄化学工業社製カイノール(品番ACC-5092-15)を用いたこと以外は、実施例1と同様にして、通液型キャパシタを備える脱イオン液製造装置を得た。カイノールは、湿式抄紙法ではなく、紡織シートを炭化賦活して作製された活性炭繊維シートである。カイノールの目付(g/m2)、厚み、活性炭繊維の割合(質量%)、比表面積(m2/g)、ミクロ細孔容積(ml/g)、メソ細孔容積(ml/g)、全細孔容積(ml/g)、全細孔容積に対するメソ細孔容積の割合(%)を表1に示す。なお、脱イオンシートの比表面積(m2/g)、ミクロ細孔容積(ml/g)、メソ細孔容積(ml/g)、全細孔容積(ml/g)は、それぞれ、上記の方法により算出した値である。
(Comparative Example 1)
A deionized liquid production apparatus equipped with a liquid-flow type capacitor was obtained in the same manner as in Example 1 except that Kyonoru (product number ACC-5092-15) manufactured by Gunei Chemical Industry Co., Ltd. was used as the deionized sheet. Kynol is not a wet papermaking method but an activated carbon fiber sheet produced by carbonizing a textile sheet. Kynol basis weight (g / m 2 ), thickness, ratio of activated carbon fibers (mass%), specific surface area (m 2 / g), micropore volume (ml / g), mesopore volume (ml / g), Table 1 shows the total pore volume (ml / g) and the ratio (%) of the mesopore volume to the total pore volume. The specific surface area (m 2 / g), micropore volume (ml / g), mesopore volume (ml / g), and total pore volume (ml / g) of the deionized sheet are as described above. It is a value calculated by the method.
 次に、比較例1の脱イオン液製造装置を用い、実施例1と同様にして硬水を自然通水し、硬水からのイオン除去率を求めた。結果を表2に示す。なお、比較例1の脱イオン液製造装置において、全ての硬水が通水されるまでの通水流量は、平均で29ml/分であった。 Next, using the deionized liquid production apparatus of Comparative Example 1, hard water was naturally passed in the same manner as in Example 1 to determine the ion removal rate from the hard water. The results are shown in Table 2. In addition, in the deionized liquid manufacturing apparatus of Comparative Example 1, the water flow rate until all hard water was passed was 29 ml / min on average.
 (比較例2)
 積層体を形成する際に加える圧力を弱め、積層体の高さを36mmに調整したこと以外は、比較例1と同様にして、通液型キャパシタを備える脱イオン液製造装置を得た。次に、実施例1と同様にして硬水を自然通水し、硬水からのイオン除去率を求めた。結果を表2に示す。なお、比較例2の脱イオン液製造装置において、全ての硬水が通水されるまでの通水流量は、平均で100ml/分であった。
(Comparative Example 2)
A deionized liquid production apparatus including a liquid-permeable capacitor was obtained in the same manner as in Comparative Example 1 except that the pressure applied when forming the laminate was reduced and the height of the laminate was adjusted to 36 mm. Next, the hard water was naturally passed in the same manner as in Example 1 to obtain the ion removal rate from the hard water. The results are shown in Table 2. In the deionized liquid production apparatus of Comparative Example 2, the water flow rate until all hard water was passed was 100 ml / min on average.
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000001
Figure JPOXMLDOC01-appb-T000002
Figure JPOXMLDOC01-appb-T000002
 表2に示される結果から明らかな通り、湿式抄紙法で形成した脱イオンシートを用いた実施例1の脱イオン液製造装置によれば、脱イオンシートの活性炭繊維を高密度なものとしながら、通水の際に抵抗の少ないシートに成形することができることに加え、バインダー繊維の融着に起因する活性炭繊維の比表面積の低下が抑制されやすくなり、硬水からの優れたイオン除去率と、自然通水による高い通水流量が得られた。一方、乾式法で形成された市販の活性炭シート(カイノール)を用い、積層体の層数と厚みとを実施例1と同じにした比較例1の脱イオン液製造装置では、イオン除去率は非常に高くなるものの、通水流量が非常に小さくなり、実用できるものではなかった。また、比較例1の脱イオン液製造装置の通水流量を大きくするために、積層体の厚さを大きくして層の密度を小さくした比較例2の脱イオン液製造装置では、通水流量は実施例1と同じ値に高められたものの、イオン除去率が低下してしまった。 As is apparent from the results shown in Table 2, according to the deionized liquid production apparatus of Example 1 using the deionized sheet formed by the wet papermaking method, while making the activated carbon fibers of the deionized sheet high in density, In addition to being able to be molded into a sheet with low resistance when passing water, the decrease in the specific surface area of the activated carbon fiber due to the fusion of the binder fiber is easily suppressed, and an excellent ion removal rate from hard water and natural A high water flow rate was obtained. On the other hand, in the deionized liquid production apparatus of Comparative Example 1 using a commercially available activated carbon sheet (Kinol) formed by a dry method and having the same number of layers and thickness as those of Example 1, the ion removal rate is very high. However, the water flow rate became very small and was not practical. Further, in order to increase the water flow rate of the deionized liquid production apparatus of Comparative Example 1, in the deionized liquid production apparatus of Comparative Example 2 in which the thickness of the laminate is increased to reduce the layer density, Was raised to the same value as in Example 1, but the ion removal rate was lowered.
(実施例2)
 積層体を形成する際に加える圧力を実施例1よりも少し弱め、積層体の高さが27mmとなるようにしたこと以外は、実施例1と同様にして、通液型キャパシタを備える脱イオン液製造装置を得た。次に、実施例1と同様にして硬水を自然通水し、硬水からのイオン除去率を求めた。結果を表3に示す。なお、実施例2の脱イオン液製造装置において、全ての硬水が通水されるまでの通水流量は、平均で130ml/分であった。
(Example 2)
Deionization provided with a liquid-flow type capacitor in the same manner as in Example 1 except that the pressure applied when forming the laminate was slightly weaker than that in Example 1 and the height of the laminate was 27 mm. A liquid production apparatus was obtained. Next, the hard water was naturally passed in the same manner as in Example 1 to obtain the ion removal rate from the hard water. The results are shown in Table 3. In addition, in the deionization liquid manufacturing apparatus of Example 2, the water flow rate until all hard water was passed was 130 ml / min on average.
(実施例3)
 積層体を形成する際に加える圧力を実施例2よりもさらに弱め、積層体の高さが30mmとなるようにしたこと以外は、実施例1と同様にして、通液型キャパシタを備える脱イオン液製造装置を得た。次に、実施例1と同様にして硬水を自然通水し、硬水からのイオン除去率を求めた。結果を表3に示す。なお、実施例3の脱イオン液製造装置において、全ての硬水が通水されるまでの通水流量は、平均で170ml/分であった。
Example 3
Deionization provided with a liquid-permeable capacitor in the same manner as in Example 1 except that the pressure applied when forming the laminate was further weakened compared to Example 2 and the height of the laminate was 30 mm. A liquid production apparatus was obtained. Next, the hard water was naturally passed in the same manner as in Example 1 to obtain the ion removal rate from the hard water. The results are shown in Table 3. In addition, in the deionized liquid manufacturing apparatus of Example 3, the water flow rate until all hard water was passed was 170 ml / min on average.
(実施例4)
 積層体の層数を54層から81層に増やしたこと、及び、積層体の高さが37.5mmとなるようにしたこと以外は、実施例1と同様にして、通液型キャパシタを備える脱イオン液製造装置を得た。次に、実施例1と同様にして硬水を自然通水し、硬水からのイオン除去率を求めた。結果を表3に示す。なお、実施例4の脱イオン液製造装置において、全ての硬水が通水されるまでの通水流量は、平均で120ml/分であった。
Example 4
A liquid-permeable capacitor is provided in the same manner as in Example 1 except that the number of layers of the laminated body is increased from 54 to 81 and the height of the laminated body is 37.5 mm. A deionized liquid production apparatus was obtained. Next, the hard water was naturally passed in the same manner as in Example 1 to obtain the ion removal rate from the hard water. The results are shown in Table 3. In addition, in the deionized liquid manufacturing apparatus of Example 4, the water flow rate until all hard water was passed was 120 ml / min on average.
Figure JPOXMLDOC01-appb-T000003
Figure JPOXMLDOC01-appb-T000003
 表3に示される結果から明らかな通り、実施例1よりも積層体の厚さを大きくして層の密度を小さくした実施例2の脱イオン液製造装置においては、通水流量の平均を130ml/分にまで高めたにも拘わらず、高いイオン除去率を有していた。また、実施例2よりもさらに積層体の厚さを大きくして層の密度を小さくした実施例3の脱イオン液製造装置においては、通水流量の平均を170ml/分にまで高めたにも拘わらず、比較的高いイオン除去率を有していた。さらに、積層体の層数を増やし、積層体の高さを調整することによって通水流量の平均を120ml/分とした実施例4の脱イオン液製造装置においては、イオン除去率と通水流量を共に非常に高めることができた。 As is clear from the results shown in Table 3, in the deionized liquid production apparatus of Example 2 in which the thickness of the laminate was made larger than that of Example 1 to reduce the density of the layer, the average water flow rate was 130 ml. The ion removal rate was high despite the increase to 1 / min. Further, in the deionized liquid production apparatus of Example 3 in which the thickness of the laminate was further increased and the layer density was reduced as compared with Example 2, the average water flow rate was increased to 170 ml / min. Nevertheless, it had a relatively high ion removal rate. Further, in the deionized liquid production apparatus of Example 4 in which the average flow rate is 120 ml / min by increasing the number of layers in the laminate and adjusting the height of the laminate, the ion removal rate and the flow rate are as follows. We were able to greatly improve both.
(実施例5)
 ポンプを用い、実施例1の脱イオン液製造装置において全ての硬水が通水されるまでの硬水の通水流量を一定(100ml/分)に保ったこと以外は、実施例1と同様にして、硬水からのイオン除去率を求めた。結果を表4に示す。
(Example 5)
Using the pump, the same procedure as in Example 1 was performed except that the flow rate of hard water until all the hard water was passed in the deionized liquid production apparatus of Example 1 was kept constant (100 ml / min). The removal rate of ions from hard water was determined. The results are shown in Table 4.
Figure JPOXMLDOC01-appb-T000004
Figure JPOXMLDOC01-appb-T000004
 表4に示される結果から明らかな通り、ポンプで強制的に通水流量を制御した実施例5では、脱イオンを製造できるものの、自然通水を行った実施例1よりもイオン除去率は低下した。この結果から、湿式抄紙法で形成した脱イオンシートを用いた脱イオン液製造装置においては、ポンプによる強制通水よりも、脱イオンに供される液体の自重による自然通水において特に優れたイオン除去率及び通液流量を付与し得ることが明らかとなった。また、自然通水を行った実施例1~4の通液型キャパシタは、外径82mmで、高さが25~37.5mmと非常にコンパクトでもあり、例えばポット型浄水器とした場合に家庭用の冷蔵庫への収納にも十分対応可能なものであった。なお、この結果から、比較例1の脱イオン液製造装置において、実施例5と同様にして、通水流量が100ml/分になるまでポンプで通水した場合には、ほとんど脱イオンができないと考えられる。また、比較例2の脱イオン液製造装置においては、実施例5と同様にして、通水流量が100ml/分になるまでポンプで通水した場合、イオン除去率が非常に小さくなると考えられる。 As is clear from the results shown in Table 4, in Example 5 where the water flow rate was forcibly controlled by a pump, deionization could be produced, but the ion removal rate was lower than in Example 1 where natural water flow was performed. did. As a result, in the deionized liquid production apparatus using the deionized sheet formed by the wet papermaking method, ions that are particularly excellent in natural water flow due to the dead weight of the liquid used for deionization, rather than forced water flow by the pump. It became clear that a removal rate and a liquid flow rate could be provided. In addition, the liquid-passing capacitors of Examples 1 to 4 in which natural water was passed are very compact with an outer diameter of 82 mm and a height of 25 to 37.5 mm. For example, when a pot-type water purifier is used, It was able to accommodate enough to store in a refrigerator. In addition, from this result, in the deionized liquid production apparatus of Comparative Example 1, when the water was passed through the pump until the water flow rate reached 100 ml / min in the same manner as in Example 5, almost no deionization was possible. Conceivable. Further, in the deionized liquid production apparatus of Comparative Example 2, when the water is passed through the pump until the water flow rate becomes 100 ml / min as in Example 5, it is considered that the ion removal rate becomes very small.
 1…通水型キャパシタ
 2…電極
 21…脱イオンシート
 22…集電極
 3…セパレータ
DESCRIPTION OF SYMBOLS 1 ... Water-flow type capacitor 2 ... Electrode 21 ... Deionization sheet 22 ... Collector electrode 3 ... Separator

Claims (9)

  1.  活性炭繊維を含む、通液型キャパシタの電極用脱イオンシートであって、
     前記脱イオンシートは、湿式抄紙法により形成されたものである、通液型キャパシタの電極用脱イオンシート。
    A deionized sheet for electrodes of liquid-permeable capacitors containing activated carbon fibers,
    The deionized sheet is a deionized sheet for electrodes of a liquid-permeable capacitor, which is formed by a wet papermaking method.
  2.  77.4Kにおける窒素吸着等温線によりDH法で求めた細孔分布において細孔直径20Å以上500Å未満の範囲のメソ細孔容積が0.002~0.8ml/gであり、かつ、全細孔容積に対する前記メソ細孔容積の割合が1~80%である、請求項1に記載の通液型キャパシタの電極用脱イオンシート。 In the pore distribution determined by the DH method using a nitrogen adsorption isotherm at 77.4K, the mesopore volume in the range of pore diameters of 20 mm or more and less than 500 mm is 0.002 to 0.8 ml / g, and the total pores 2. The deionized sheet for electrodes of a liquid-permeable capacitor according to claim 1, wherein a ratio of the mesopore volume to the volume is 1 to 80%.
  3.  前記活性炭繊維は、Mg、Mn、Fe、Y、Pt、及びGdからなる群から選択された少なくとも1種を含む、請求項1または2に記載の通液型キャパシタの電極用脱イオンシート。 3. The deionized sheet for electrodes of a liquid-permeable capacitor according to claim 1, wherein the activated carbon fiber includes at least one selected from the group consisting of Mg, Mn, Fe, Y, Pt, and Gd.
  4.  電極とセパレータとが交互に積層された積層体を備える通液型キャパシタであって、
     前記電極は、請求項1~3のいずれかに記載の通液型キャパシタの電極用脱イオンシートを有する、通液型キャパシタ。
    A liquid-permeable capacitor comprising a laminate in which electrodes and separators are alternately laminated,
    The liquid-permeable capacitor, wherein the electrode has a deionizing sheet for an electrode of the liquid-permeable capacitor according to any one of claims 1 to 3.
  5.  請求項4に記載の通液型キャパシタと、
     前記通液型キャパシタの前記電極に電気的に接続された電源と、
     前記通液型キャパシタを収容する容器と、
    を備え、
     前記通液型キャパシタにおいては、前記電源の正極側が電気的に接続された前記電極と、負極側が電気的に接続された前記電極とが、前記セパレータを介して前記積層体の積層方向に交互に積層されており、
     前記容器内において、前記通液型キャパシタの積層方向の一方側から他方側に向かって、脱イオンに供される液体が通液される、脱イオン液製造装置。
    The liquid-permeable capacitor according to claim 4,
    A power source electrically connected to the electrode of the liquid-permeable capacitor;
    A container for accommodating the liquid-flow type capacitor;
    With
    In the liquid passing type capacitor, the electrode to which the positive electrode side of the power source is electrically connected and the electrode to which the negative electrode side is electrically connected are alternately arranged in the stacking direction of the stacked body through the separator. Are stacked,
    In the container, a deionized liquid production apparatus in which a liquid to be deionized is passed from one side to the other side in the stacking direction of the liquid passing type capacitor.
  6.  前記脱イオンに供される液体の通液が、前記脱イオンに供される液体の自重により行われる、請求項5に記載の脱イオン液製造装置。 The deionized liquid production apparatus according to claim 5, wherein the liquid supplied to the deionization is passed by the weight of the liquid to be deionized.
  7.  請求項5または6に記載の脱イオン液製造装置を用いる、脱イオン液の製造方法であって、
     前記通液型キャパシタの積層方向の一方側から他方側に向かって、脱イオンに供される液体を通液しながら、前記電極間に電圧を印加する、脱イオン液の製造方法。
    A method for producing a deionized liquid using the deionized liquid producing apparatus according to claim 5, wherein:
    A method for producing a deionized liquid, wherein a voltage is applied between the electrodes while flowing a liquid to be used for deionization from one side to the other side in the stacking direction of the liquid-permeable capacitor.
  8.  活性炭繊維を含み、湿式抄紙法により形成されたシートの、通液型キャパシタの電極の脱イオンのための使用。 Use of sheet containing activated carbon fiber and formed by wet papermaking method for deionization of electrode of liquid-pass capacitor.
  9.  通液型キャパシタの電極用脱イオンシートとして、活性炭繊維を含み、湿式抄紙法により形成された脱イオンシートを用いる、通液型キャパシタの電極の脱イオン方法。 A method for deionizing electrodes of liquid-permeable capacitors using deionized sheets containing activated carbon fibers and formed by a wet papermaking method as deionized sheets for electrodes of liquid-permeable capacitors.
PCT/JP2014/079589 2013-11-19 2014-11-07 Deionizing sheet for use in electrode in flow-through-type capacitor WO2015076123A1 (en)

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