JPWO2013108597A1 - Liquid-permeable capacitor, deionized liquid production apparatus, and deionized liquid production method - Google Patents

Abstract

A liquid passing type capacitor in which a plurality of cells are stacked, the cell including a first electrode, a second electrode, a separator interposed between the first electrode and the second electrode, wherein the first electrode is made of a graphite sheet. A first current collector sheet, a first porous carbon sheet laminated on the first current collector sheet, and a cation exchange membrane laminated on the first porous carbon sheet, the second electrode comprising graphite A cation exchange membrane and an anion comprising: a second current collector sheet comprising a sheet; a second porous carbon sheet laminated on the second current collector sheet; and an anion exchange membrane laminated on the second porous carbon sheet. The exchange membrane is disposed so as to face the separator, and at least one of the first current collector sheet and the second current collector sheet has a tab portion that does not face the porous carbon sheet, and at least 2 Two or more tab parts are It is connected by arranged in contact conductive sheet.

Description

  The present invention relates to a liquid-passing capacitor, a deionized liquid production apparatus, and a deionized liquid production method for adsorbing and removing ions in a liquid for desalting.

  2. Description of the Related Art Liquid passing type capacitors for removing ions in a liquid using an electrostatic force are known. The desalting method using a flow-through capacitor is a desalting method that is excellent in energy efficiency because electrical energy supplied during ion adsorption can be stored in the capacitor, and electrical energy can be recovered during ion desorption. Further, the liquid passing type capacitor can be operated even at a low voltage. Furthermore, in a liquid-flowing type capacitor, since the polarity is switched between when ions are adsorbed and when they are desorbed, it is difficult for scale to be generated inside the apparatus. From these points, the liquid-pass capacitor is a desalting method with high equipment merit.

  For example, Patent Document 1 below discloses a liquid-permeable capacitor in which at least one ion adsorption electrode is a porous metal foil. Patent Document 2 below includes a rechargeable electrode that includes a porous material and is configured to adsorb ions of opposite charges, and an ion exchange material that is in contact with the porous material of the rechargeable electrode. An electrode assembly is disclosed. In this electrode assembly, the ion exchange material is charged the same as the rechargeable electrode, and the ion exchange material is permeable to ions of opposite charge and at least partially to ions of the same charge. It is disclosed that it is impermeable.

JP 2011-167463 A Special table 2010-513018

  With reference to FIG. 9 and FIG. 10, the configuration of the liquid passing type capacitor 110 will be described. FIG. 9 is a partially exploded schematic view for explaining the cell structure of the liquid-permeable capacitor 110. FIG. 10 is a schematic view of the XX ′ cross section of FIG. 9 when the cells of the liquid-passing capacitor 110 are assembled. As shown in FIGS. 9 and 10, the liquid-flowing capacitor 110 includes two electrodes 101 and 102 for adsorbing ions in the liquid, and a separator 3 interposed between the electrodes 101 and 102. A plurality of cells 120 are stacked. Each electrode 101 includes a current collector 1a (1a ′) and a porous carbon sheet 1b (1b ′) laminated on the current collector 1a (1a ′). Each electrode 102 includes a current collector 2a and a porous carbon sheet 2b laminated on the current collector 2a. The electrodes 101 and 102 are counter electrodes. And the laminated body formed by accumulating the cell 120 several cells is fastened with the metal fastening bolts 5a and 5b, for example. In each cell 120, the fastening bolt 5a electrically connects the tab portions 1d provided on the current collector 1a so as not to face the porous carbon sheet 1b (1b ′). Similarly, the fastening bolt 5b electrically connects the tab portion 2d provided on the current collector 2a so as not to face the porous carbon sheet 2b in each cell 120. The plurality of current collectors 1a or the plurality of current collectors 2a are electrically connected to each other by the tab portion 1d or the tab portion 2d fastened by the fastening bolt 5a or the fastening bolt 5b.

  In the liquid passing type capacitor 110, for example, the liquid to be processed is passed in the direction indicated by the white arrow in FIG. When a voltage is applied between the electrode 101 and the electrode 102 by an external power supply (not shown) and a liquid is passed between the capacitors formed by the electrode 101 and the electrode 102, ions in the passed liquid are porous carbon. Adsorbed to the sheet 1b (1b ') and the porous carbon sheet 2b. Then, the processing liquid after the ions are adsorbed and removed by the capacitor reaches the liquid passage hole 8 provided in the center of each cell, and is discharged to the outside through the liquid passage hole 8.

  As described above, in the liquid-flowing capacitor 110, the current collectors 1a having the same polarity and the current collectors 2a are connected to each other by the metal fastening bolts 5a and 5b. It was electrically connected by fastening. Only by fastening with such fastening bolts, if the liquid to be treated contains a high concentration of ions, or if the liquid to be treated is processed at a high flow rate, the conductivity is insufficient and the removal of ions is performed. The rate may decline. In particular, when a material having a high electrical conductivity anisotropy, such as a graphite (graphite) sheet, having a high electrical conductivity in the surface direction of the sheet and low in the vertical direction is used as a current collector. In some cases, the ion removal rate may be reduced due to lack of electrical conductivity in the vertical direction.

One aspect of the present invention is a liquid-permeable capacitor formed by stacking a plurality of cells, and the cell includes a first electrode, a second electrode, a separator interposed between the first electrode and the second electrode. A first current collector sheet made of a graphite sheet; a first porous carbon sheet laminated on the first current collector sheet; and a cation exchange membrane laminated on the first porous carbon sheet. A second current collector sheet made of a graphite sheet, a second porous carbon sheet laminated on the second current collector sheet, and an anion laminated on the second porous carbon sheet The cation exchange membrane and the anion exchange membrane are disposed so as to face each other with a separator interposed therebetween, and at least one of the first current collector sheet and the second current collector sheet is made of each porous carbon. At least two tabs that do not face the sheet Tab portions of the above are flow-through capacitor that is electrically connected with placed conductive sheets to contact the surface of the tab portion.
In addition, another aspect of the present invention includes a liquid-permeable capacitor as described above, a DC power supply, and a container that stores the liquid-flowing capacitor, and the DC power supply has a positive polarity and a negative polarity that are mutually opposite. The container is connected to the first electrode and the second electrode in a replaceable manner, and the container is processed from the liquid supply port for supplying a liquid containing an ionic substance to the liquid-flowing capacitor, and the liquid-passing capacitor. It is a deionized liquid manufacturing apparatus provided with the drainage port for discharging | emitting a liquid.
Furthermore, another aspect is a method for producing a deionized liquid using the deionized liquid production apparatus as described above, wherein ions are supplied from a liquid supply port while applying a voltage to the first electrode and the second electrode by a DC power source. A first step of supplying a treatment liquid containing an ionic substance to adsorb ions derived from the ionic substance on each electrode surface and discharging the treatment liquid from which the ionic substance has been removed from a drainage port; Adhering to the surface of each electrode by supplying a liquid to be treated containing an ionic substance from a liquid supply port while applying a voltage with the polarity of the positive electrode and the negative electrode of each electrode reversed from the first step And a second step of discharging the ion concentrate containing the ions from the drain port, and a method for producing a deionized liquid.

  The objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description and the accompanying drawings.

  ADVANTAGE OF THE INVENTION According to this invention, compared with the conventional liquid-flow type capacitor, the removal capability of an ionic substance can provide a liquid-flow type capacitor, the manufacturing method of a deionized liquid, and a deionized liquid manufacturing apparatus.

It is a partial exploded perspective schematic diagram for explaining the principal part of composition of liquid penetration type capacitor 100 of a 1st embodiment. FIG. 2A is a schematic top view of the liquid-permeable capacitor 100. FIG. 2B is a schematic front view of the liquid-permeable capacitor 100. FIG. 3A is a schematic diagram for explaining an example of an arrangement pattern of conductive sheets of a liquid-permeable capacitor. FIG. 3B is a schematic diagram for explaining an example of an arrangement pattern of conductive sheets of a liquid-permeable capacitor. FIG. 4 is a schematic explanatory diagram for explaining a configuration of a deionized liquid manufacturing apparatus 200 including the liquid-permeable capacitor 100 according to the first embodiment. FIG. 5A is an explanatory diagram for explaining a first stage of the operation of the capacitor structure in the liquid-flowing capacitor 100. FIG. 5B is an explanatory diagram for explaining a second stage of the action of the capacitor structure in the liquid-permeable capacitor 100. FIG. 5C is an explanatory diagram for explaining a third stage of the action of the capacitor structure in the liquid-permeable capacitor 100. 4 is a graph plotting changes in current and voltage with respect to time (seconds) during operation of the liquid-flowing capacitor of Example 1. 6 is a graph plotting changes in electrical conductivity with respect to time (seconds) during operation of the liquid-pass capacitor of Example 1. FIG. It is the graph which plotted the average removal rate with respect to the flow rate of water when the liquid-flow type capacitor of an Example and a comparative example was drive | operated. It is a schematic exploded view for demonstrating the cell structure of the conventional liquid penetration type capacitor. FIG. 10 is a schematic view of the vicinity of the XX ′ cross section of FIG. 9.

The configuration of the liquid-permeable capacitor according to the embodiment of the present invention will be described.
FIG. 1 is a partially exploded perspective schematic view for explaining a main part of the configuration of the liquid-permeable capacitor 100 of the present embodiment, FIG. 2A is a schematic top view of the liquid-permeable capacitor 100, and FIG. 2B is a schematic front view thereof. is there.

  As shown in FIG. 1, the liquid-permeable capacitor 100 of the present embodiment has a capacitor structure in which a plurality of cells 10 are stacked. Each cell 10 includes a first electrode 1, a second electrode 2, and a separator 3 interposed between the first electrode 1 and the second electrode 2. In FIG. 1, for convenience of explanation, a state in which a part of a layer is disassembled so as to develop a laminated structure is schematically illustrated.

  The first electrode 1 includes a first current collector sheet 1a or a first current collector sheet 1a ′ and a first porous carbon sheet 1b (1b ′) laminated on the first current collector sheet 1a (1a ′). And a cation exchange membrane 1c (1c ′) laminated on the first porous carbon sheet 1b (1b ′). The second electrode 2 includes a second current collector sheet 2a, a second porous carbon sheet 2b laminated on the second current collector sheet 2a, and an anion exchange membrane 2c laminated on the second porous carbon sheet 2b. With. The cation exchange membrane 1c (1c ′) and the anion exchange membrane 2c are arranged to face each other with the separator 3 interposed therebetween. The first current collector sheet 1a and the first porous carbon sheet 1b, the second current collector sheet 2a and the second porous carbon sheet 2b, the cation exchange membrane 1c and the anion exchange membrane 2c are substantially in the center. The liquid passage hole 8 for passing the liquid deionized by the cell 10 is provided. On the other hand, the first current collector sheet 1a ′ and the first porous carbon sheet 1b ′ cation exchange membrane 1c ′ do not have the liquid passage hole 8 in order to regulate the liquid passage direction, and form the uppermost cell.

  The first current collector sheet 1a, 1a 'has a tab portion 1d that does not face the first porous carbon sheet 1b, 1b', and the second current collector sheet 2a faces the second porous carbon sheet 2b. The tab portion 2d is not provided. The plurality of tab portions 1d and the plurality of tab portions 2d are fastened by conductive fastening bolts 5a and 5b, respectively. Such fastening bolts 5a and 5b are electrically connected by bringing the tab portions 1d or the tab portions 2d into contact with each other on the surface. The fastening bolt 5a for fastening the plurality of tab portions 1d and the fastening bolt 5b for fastening the plurality of tab portions 2d are respectively connected to one electrode side and the other electrode side of the DC power supply, as will be described later. Then, the plurality of first current collector sheets 1a or the plurality of second current collector sheets 2a are made equipotential.

  In the liquid-permeable capacitor 100, as shown in FIG. 1, FIG. 2A and FIG. 2B, the plurality of tab portions 1d are one conductive sheet 6a arranged so as to contact the surface of each tab portion 1d. Electrically connected. Similarly, the plurality of tab portions 2d are electrically connected by one conductive sheet 6b arranged so as to be in contact with the surface of each tab portion 2d. Thus, by connecting the plurality of tab portions 1d or the plurality of tab portions 2d via the conductive sheet 6a or the conductive sheet 6b, the plurality of first current collector sheets 1a or the plurality of second current collector sheets 1a are connected to each other. The current collector sheets 2a are electrically connected in a direction parallel to the sheet surface. According to the connection in the parallel direction to the sheet surface, for example, as the first current collector sheet or the second current collector sheet, the electrical conductivity is high in the surface direction of the sheet like a graphite (graphite) sheet. Even when a sheet material having high anisotropy in electrical conductivity, such as low in the vertical direction, is used, sufficient conductivity can be obtained. Thereby, even when a high concentration ionic substance is contained in the liquid to be processed or when the liquid is processed at a high flow rate, a high ion removal rate can be maintained.

  In addition, in the current collector sheet shown in FIGS. 1, 2A and 2B, two tab portions are provided on one side of one current collector sheet, but the tab of one current collector sheet is provided. The number of parts is not particularly limited, and may be one place or three or more places. Moreover, it is preferable to arrange | position a conductive sheet so that a tab part may contact directly so that the tab parts of several collector sheet of the same polarity may mutually conduct. An example of the arrangement pattern of the conductive sheet is shown in FIGS. 3A and 3B. As the arrangement pattern, even if the conductive sheet C is arranged so as to sew the tab portions D one by one as in the arrangement pattern shown in FIG. 3A, the plurality of tab portions D are stacked as shown in FIG. 3B. The conductive sheet C may be arranged so as to sew the body.

  As the conductive sheet, any conductive sheet having high corrosion resistance can be used without particular limitation. Specific examples of such a conductive sheet include, for example, a titanium metal made of titanium or a titanium alloy, a metal foil made of gold, platinum, silver, or a composite material thereof, or a graphite sheet. In these, the titanium foil formed from the titanium-type metal from the point which is excellent in the balance of corrosion resistance, electroconductivity, and low cost is used preferably.

  The thickness of the conductive sheet is preferably 20 to 200 μm, and more preferably 30 to 100 μm, from the viewpoint that it is not necessary to secure an excessive space while maintaining high conductivity.

  Moreover, as a fastening bolt, what uses the fastening means of the bolt and nut structure using conductive bolts and nuts, such as a metal bolt, is preferable. In addition, since the liquid passing type capacitor is used for desalting the liquid to be treated, it is particularly preferable to use a metal bolt having high corrosion resistance such as a titanium bolt made of titanium or a titanium alloy. Further, the fastening means is not limited to the bolt structure, and means such as clamping with a clip-like structure may be used.

  Moreover, when fastening with a fastening bolt, the current collector sheet or the conductive sheet may be damaged by the fastening pressure. In order to prevent such damage, a metal plate 4 having excellent corrosion resistance and conductivity such as a titanium plate as shown in FIG. 1 is interposed between the bolt head of the fastening bolt and the conductive sheet. It is preferable to disperse the pressure. Although the thickness of such a metal plate 4 is not specifically limited, It is preferable that it is about 0.5-5 mm. In this case, the metal plate, the fastening bolt, the current collector sheet, and the conductive sheet are electrically connected, so that they are electrically connected.

  One cell is composed of two electrodes sandwiching a separator. The number of cells approximately matches the number of separators. Although the number of cells of the liquid-permeable capacitor of this embodiment is not particularly limited, specifically, it is preferably 3 to 100, and more preferably about 5 to 50, for example.

  Next, other elements constituting the liquid-permeable capacitor 100 will be described in detail.

  A graphite sheet is used as the first current collector sheet and the second current collector sheet. Specific examples of the graphite sheet include a graphite sheet formed from expanded graphite. The graphite sheet has an excellent balance of corrosion resistance, high conductivity, and low cost. On the other hand, the graphite sheet is characterized in that the electrical conductivity is lower in the thickness direction than in the surface direction of the sheet. When the tab portion is fastened with a fastening bolt or the like using such a graphite sheet having electrical conductivity anisotropy as a current collector, the electrical conductivity in the thickness direction tends to be low and the surface direction of the sheet tends to be high. . In the liquid-permeable type capacitor according to the present embodiment, the conductive sheet is disposed so as to contact the tab portion of the graphite sheet, and the plurality of tab portions are electrically connected to each other, thereby increasing the height in the surface direction of the graphite sheet. The conductivity can be fully utilized. The thickness of the graphite sheet is preferably 100 to 500 μm.

  Examples of the first porous carbon sheet and the second porous carbon sheet include molded sheets obtained by binding porous carbon particles such as activated carbon particles with a binder.

  Specific examples of the activated carbon particles include, for example, wood, sawdust, charcoal, fruit husks such as coconut husk and walnut husk, fruit seeds, pulp production by-products, lignin, molasses, etc .; peat, grass charcoal, lignite , Mineral activated carbon particles obtained by carbonizing and activating lignite, lecherous coal, anthracite, coke, coal tar, coal pitch, petroleum distillation residue, petroleum pitch, etc .; carbonizing and activating phenol, saran, acrylic resin, etc. Synthetic resin-based activated carbon particles obtained by natural carbon; natural fiber-based activated carbon particles obtained by carbonizing and activating regenerated fibers (rayon) and the like. Among these, coconut shell activated carbon particles are particularly preferable from the viewpoint of excellent adsorption performance.

  The center particle diameter of the activated carbon particles is preferably 1 to 100 μm, more preferably 2 to 50 μm, and particularly preferably 3 to 30 μm. Here, the central particle diameter is the particle diameter when the integrated value of the mass of all particles is 50% in the particle size distribution. Such a center particle diameter can be measured, for example, using a Nikkiso Co., Ltd. Microtrac particle size distribution measuring device (MT3300). When the central particle diameter of the activated carbon particles is too small, the amount of binder to be used increases, and the proportion of the activated carbon decreases, so that the ion trapping ability tends to decrease. Moreover, when the center particle diameter of activated carbon particle is too large, the surface uniformity of the obtained activated carbon sheet will worsen, and there exists a tendency for the ion capture capability to fall.

The specific surface area of the activated carbon particles, 700~2500m ² / g, more preferably a 1500~2000m ² / g. When the specific surface area is too small, the deionization ability is lowered, and when ions are adsorbed on the surface of the activated carbon sheet with the polarity of the electrode being reversed, ions tend not to be desorbed. In addition, when the specific surface area is too large, not only the performance per volume is lowered, but also the amount of binder used is increased and the proportion of activated carbon is decreased, so that the ion trapping ability tends to be lowered. The specific surface area can be measured, for example, by the following method. The nitrogen adsorption isotherm of activated carbon at 77K is measured using BELSORP-mini manufactured by Nippon Bell Co., Ltd. Then, from the obtained nitrogen adsorption isotherm, analysis by the multipoint method is performed by the BET equation, and the specific surface area is calculated from the straight line in the region of the relative pressure p / p ₀ = 0.01 to 0.1 of the obtained curve. It can be calculated.

The pore volume of the activated carbon particles is preferably 0.5 to 1.2 mL / g, more preferably 0.7 to 1.0 mL / g. If the pore volume is too small, ions tend to be difficult to desorb when the polarity of the electrode is reversed and ions adsorbed on the surface of the activated carbon sheet are desorbed. Moreover, when the pore volume is too large, the performance per volume tends to decrease. The pore volume can be measured, for example, by the following method. The nitrogen adsorption isotherm of activated carbon at 77K is measured using BELSORP-mini or the like. The pore volume can be calculated from the nitrogen adsorption volume (mL / g) in the standard state at a relative pressure p / p ₀ = 0.99 by the following formula.
Pore volume = (nitrogen adsorption volume in the standard state at p / p ₀ = 0.99) × 28/22400 / 0.808

Further, the average pore diameter of the activated carbon particles is preferably 1.5 to 2.4 nm, and more preferably 1.6 to 2.2 nm. If the average pore diameter is too small, ions tend to be difficult to desorb when the polarity of the electrode is reversed and ions adsorbed on the surface of the activated carbon sheet are desorbed. Moreover, when the average pore diameter is too large, the performance per volume tends to decrease. The average pore diameter can be calculated by the following formula from the specific surface area and pore volume determined as described above.
Average pore diameter = pore volume x 4000 / specific surface area

The surface functional group amount of the activated carbon particles is preferably 0.1 to 0.8 meq / g, more preferably 0.2 to 0.5 meq / g. When the amount of surface functional groups is too small, sheet molding tends to be difficult due to the influence of the surface charge of the activated carbon particles. Moreover, when the amount of surface functional groups is too large, the durability of the performance tends to decrease. The amount of surface functional groups can be measured, for example, by the following method. It vacuum-drys for 8 to 10 hours with the constant temperature dryer adjusted to 120 degreeC, Then, it cools in the desiccator which put the silica gel as a desiccant. Then, 1 g of activated carbon cooled in a 100 mL stoppered Erlenmeyer flask is accurately weighed to a unit of 0.1 mg. Then, 50 mL of N / 10 sodium ethoxide ethanol solution is added to the stoppered Erlenmeyer flask in which the activated carbon has been weighed, and shaken at 160 rpm and 25 ° C. for 24 hours. Then, after shaking, the supernatant and the precipitate are separated by centrifugation, 20 mL of the supernatant is accurately weighed into a 100 mL Erlenmeyer flask, titrated with N / 10 hydrochloric acid at the titration end point, and titrated with N / 10 hydrochloric acid. Ask for. On the other hand, a blank test is performed with a solution containing no sample, and a blank test titer is also obtained. And the amount of surface functional groups is calculated by the following formula.
Surface functional group amount = ((blank test titration) − (sample titration)) × 0.1 × f (hydrochloric acid factor) × 50/20

  The activated carbon sheet is obtained by forming a mixture containing activated carbon particles and a binder into a sheet shape. In addition, as a binder, when using for water purification, it is preferable to use the binder which is not harmful to living organisms. The ratio of the activated carbon particles contained in the activated carbon sheet is preferably 50 to 99% by mass, more preferably 80 to 95% by mass. When the ratio of the activated carbon particles contained in the activated carbon sheet is too low, the performance tends to decrease.

  Specific examples of the binder include, for example, polytetrafluoroethylene, polyvinylidene fluoride, fluoroethylene-perfluoroalkoxyethylene copolymer, ethylene-tetrafluoroethylene copolymer, styrene-butadiene copolymer, polyethylene, polypropylene, polystyrene. , Ethylene-methacrylic acid copolymer, ethylene-vinyl acetate copolymer, polyethylene terephthalate, polybutylene terephthalate, polymethyl methacrylate, polyacrylonitrile, polyamide and the like. Among these, polytetrafluoroethylene is preferable from the viewpoints of binding properties and stability.

  The activated carbon sheet may further contain a conductive material. By blending the conductive material, excellent conductivity can be imparted to the activated carbon sheet. Specific examples of such a conductive material include, for example, carbon-based materials such as acetylene black, ketjen black, and graphite; noble metals such as gold, platinum, and silver; titanium nitride, titanium silicon carbide, titanium carbide, titanium boride, And highly conductive ceramics such as zirconium boride. Among these, a carbon-based material is preferable because it is excellent in cost and workability.

  Although the thickness of an activated carbon sheet is not specifically limited, About 200-500 micrometers is preferable from the point that an electrical resistance does not become high too much.

  Specific examples of the separator include, for example, a resin net of synthetic fibers, a woven fabric, a paper-like aggregate, a nonwoven fabric in which synthetic fibers or recycled fibers are integrated. Among these, resin nets and nonwoven fabrics, particularly resin nets, are preferable from the viewpoint of excellent liquid permeability and economic efficiency.

  Examples of the material of the separator include polyethylene terephthalate, polypropylene, polyamide, polytetrafluoroethylene, ethylene-tetrafluoroethylene copolymer, polyether ether ketone, and the like. Among these, polyethylene terephthalate and polypropylene, particularly polyethylene terephthalate are preferable from the viewpoint of low cost and processability.

  The thickness of the separator is preferably 50 to 250 μm, more preferably 70 to 150 μm. When the thickness of the separator is too thick, the ion trapping ability tends to decrease due to an increase in electrical resistance between cells during energization. Moreover, when too thin, there exists a tendency for liquid flow resistance to become large.

  Moreover, it is preferable that the aperture ratio of a separator is 20 to 80%, Furthermore, it is preferable that it is 30 to 70%. If the opening rate of the separator is too small, the liquid flow resistance may be too large, and liquid flow may be difficult. Moreover, when too large, there exists a possibility that it may become unable to express the performance as a liquid-permeable type capacitor by carrying out an internal short circuit in an opening part.

  The anion exchange membrane is not particularly limited, and specific examples include a membrane containing an anion exchange group such as a quaternary amino group and containing an ion exchange resin such as a styrene resin, an acrylic resin, or a fluorine resin. It is done. Further, although the cation exchange membrane is not particularly limited, specifically, for example, a membrane containing an ion exchange resin such as a styrene resin, an acrylic resin, or a fluorine resin having a cation exchange group such as a sulfone group or a carboxyl group. Can be mentioned.

  FIG. 4 is a schematic explanatory diagram for explaining a configuration of a deionized liquid manufacturing apparatus 200 including the liquid-permeable capacitor 100 according to the first embodiment. The operation of the deionized liquid manufacturing apparatus 200 provided with the liquid flow type capacitor 100 will be described with reference to FIG. The deionized liquid manufacturing apparatus 200 includes a liquid passing capacitor 100, a DC power supply 20, and a container 30 that houses the liquid passing capacitor 100. The DC power supply 20 is connected to fastening bolts 5a and 5b for fastening the first electrode 1 or the second electrode 2 of the liquid-flowing capacitor 100 by wires 20a and 20b so that the positive electrode side and the negative electrode side can be exchanged with each other. The container 30 includes a liquid supply port 31 for supplying a liquid to be processed containing an ionic substance to the liquid flow type capacitor 100, and a liquid discharge port 32 for discharging the processing liquid processed by the liquid flow type capacitor 100. Is provided. The container 30 also includes terminals 15a and 15b for energizing the fastening bolts 5a and 5b.

  In order to perform the deionization treatment of the liquid to be treated containing the ionic substance by the deionized liquid manufacturing apparatus 200, first, the liquid to be treated W1 such as water containing the ionic substance in the container 30 from the liquid supply port 31. Supply liquid. The liquid W1 to be treated is passed through the container 30 along the flow path indicated by the arrow in FIG. Then, the liquid to be treated W1 is discharged from the liquid discharge port 32 through the liquid passage hole 8 provided in the central portion of the liquid passage type capacitor 100. While supplying the liquid W1 to be treated, a voltage is applied from the DC power supply 20 to the liquid-flowing capacitor 100 via the terminals 15a and 15b connected to the fastening bolts 5a and 5b, respectively. And deionized liquid is discharged | emitted from the drain port 32 of the container 30, applying a voltage.

  Ions contained in the liquid W1 are electrostatically adsorbed to the first porous carbon sheet 1b and the second porous carbon sheet 2b when passing between the first electrode 1 and the second electrode 2. To be captured. When a large amount of ions are adsorbed on the surface of the first porous carbon sheet 1b or the second porous carbon sheet 2b, the valve V1 is opened and the valve V2 is closed to switch to the ion concentrate recovery path. The concentrated ions can be recovered by reversing the polarity of the electrodes. In this way, the adsorption capacity of the first porous carbon sheet and the second porous carbon sheet can be regenerated.

  The cycle for switching the electrodes is not particularly limited, but the adsorption process and the desorption process are performed so that the time of the adsorption process / the time of the desorption process is 1 to 5, and further 1.5 to 4.5. It is preferable to switch repeatedly.

  The operation of each capacitor in the cell 10 of the liquid-flowing capacitor 100 will be described.

  As shown in FIG. 5A, before the voltage is applied to the liquid-flowing capacitor 100, the anion (−) and cation (+) in the liquid are not changed even if the liquid to be treated W1 is passed through each cell 10. The first electrode 1 and the second electrode 2 are not captured and pass between both electrodes. As shown in FIG. 5B, when a voltage is applied between both electrodes by connecting the negative electrode side of the DC power source to the first electrode 1 and the positive electrode side of the DC power source to the second electrode 2, the cations are on the surface of the first electrode 1. Can pass through the cation exchange membrane 1c disposed on the first electrode 1 and is adsorbed on the first porous carbon sheet 1b of the first electrode 1, while the anion passes through the anion exchange membrane 2c disposed on the surface of the second electrode 2. Since it can pass through, it is adsorbed by the second porous carbon sheet 2 b of the second electrode 2. Then, as the liquid flow rate increases, the ion adsorption amount of the first electrode 1 and the second electrode 2 gradually increases, and the ion capturing ability gradually decreases. Then, as shown in FIG. 5C, the positive electrode side of the DC power source is connected to the first electrode 1, and the negative electrode side of the DC power source is connected to the second electrode 2, and a voltage opposite to that at the time of adsorption is applied between both electrodes. In this case, the cation adsorbed on the first electrode 1 and the anion adsorbed on the second electrode 2 are desorbed and released into the liquid to be passed. At this time, since the released cations cannot pass through the anion exchange membrane 2 c disposed on the surface of the second electrode 2, they are not adsorbed on the second electrode 2. Similarly, since the released anion cannot pass through the cation exchange membrane 1c disposed on the surface of the first electrode 1, it is not adsorbed on the first electrode 1. Thus, since it is suppressed that ion is re-adsorbed to the 1st electrode 1 and the 2nd electrode 2, the high concentration ion contains in the liquid passed at this time. Therefore, by periodically discharging the liquid containing this high concentration of ions, the ions in the liquid can be efficiently removed.

As a liquid passing method for removing ions in the liquid using the liquid passing type capacitor 100, either a total filtration method for filtering the whole amount of the stock solution to be treated may be adopted, or a circulation filtration method may be adopted. . The condition for passing liquid is not particularly limited, but it is preferable to carry out at a space velocity (SV) of 5 to 100 hr ⁻¹ because the pressure loss does not become too high.

  The state of the ion removal capability can be monitored by two-dimensionally plotting the relationship between the electrical conductivity of the discharged liquid and the amount of liquid flowed from the start of liquid flow. In addition, since the ion concentration in the liquid has a correlation with the electric conductivity of water, the ion removal rate can be calculated by measuring the electric conductivity of the liquid before and after the deionization process. . The ion concentration in the liquid can also be measured by a method such as ion chromatography.

  The type of the DC power supply 20 that supplies power to the deionized liquid manufacturing apparatus 200 is not particularly limited. The voltage may be adjusted from a 100 V household power supply and used as a direct current, or power may be supplied using a battery or a storage battery. Moreover, when using it outdoors, you may use independent power supplies, such as a solar cell, a wind power generator, a fuel cell, and a cogenerator. In addition, since the liquid-flowing capacitor itself has a power storage capability, a plurality of liquid-flowing capacitors may be connected and the power stored in each other may be alternately used as a power source. The voltage of the DC power supply is not particularly limited, but when the liquid-flowing capacitor 100 of the present embodiment is used, it can be operated even at a low voltage such as 1.5 to 2V.

  The liquid-permeable type capacitor and deionized liquid production apparatus of the present invention described above are independent of other water treatment means such as known water purification means, even if used alone for deionization treatment of water containing ionic substances. You may use it in combination. Specific examples of known water treatment means include, for example, water treatment means including various adsorbents such as nonwoven fabric filters, ceramic filters, activated carbon, mineral additives, ceramic filter media, hollow fiber membrane filter materials, ion adsorbent materials, and the like. Can be mentioned.

  Hereinafter, the present invention will be described more specifically with reference to examples. The scope of the present invention is not limited by the contents of the following examples.

[Example 1]
As a porous carbon sheet, activated carbon particles (coconut shells having a center particle diameter of 6 μm, a specific surface area of 1700 m ² / g, a pore volume of 0.73 mL / g, an average pore diameter of 1.7 nm, and a surface functional group amount of 0.33 meq / g) Activated carbon sheet A1 containing 10 parts by mass of polytetrafluoroethylene binder was used with respect to 100 parts by mass of activated carbon particles as raw materials, GW-H manufactured by Kuraray Chemical Co., Ltd. The activated carbon sheet A1 had a thickness of 250 μm and was cut into a length of 60 mm and a width of 60 mm.

  As a current collector sheet, a 250 μm thick graphite sheet (SIGRAFLEX S GRAFHITE FOIL manufactured by SGL Carbon Japan Co., Ltd.) formed by compression molding expanded graphite is 60 mm long and 60 mm wide, and the center of one side Were cut into a shape having two tab portions of 50 mm in length and 20 mm in width. Furthermore, the tab part was provided with a hole with a diameter of 6.5 mm through which a bolt for fastening the laminated body can pass.

  Further, as the separator, a polyester resin net (PETEX07-80 / 32 manufactured by Sefar AG) having a thickness of 90 μm, a wire diameter of 62 μm, an aperture of 80 μm, and an aperture ratio of 32% was cut into 68 mm length and 68 mm width. .

  Furthermore, as the anion exchange membrane, a 130 μm-thick Selemion AMV manufactured by Asahi Glass Co., Ltd. was used, and as the cation exchange membrane, a 130 μm-thick Selemion CMV manufactured by Asahi Glass Co., Ltd. cut into a length of 64 mm and a width of 64 mm was used.

  The activated carbon sheet, current collector sheet, separator, anion exchange membrane, and cation exchange membrane described above were laminated to form a laminate. Specifically, current collector sheet, activated carbon sheet, cation exchange membrane, separator, anion exchange membrane, activated carbon sheet, current collector sheet, activated carbon sheet, anion exchange membrane ... cation exchange membrane, activated carbon sheet, current collector A laminated body having a 10-cell capacitor structure was formed. In addition, the laminated body overlapped the area | region of 60 mm in length and 60 mm in width of each component, and the tab part of each collector sheet was arrange | positioned so that the tab part of the nearest layer which pinched | interposed the separator might face the mutually reverse direction. Further, a diameter of 9 mm for passing a deionized liquid to be treated is passed through the central portions of the current collector sheet, separator, anion exchange membrane, and cation exchange membrane, which form each layer except the uppermost layer. The liquid passage hole was formed.

  Then, as shown in FIGS. 2A and 2B, a plurality of tabs overlapping in each direction of the laminate are fastened with two titanium bolts (four in total) and nuts, respectively. Fixed. At this time, between the tab portions in the same direction, a single band-shaped titanium foil having a width of 20 mm and a thickness of 100 μm is overlapped on the sheet surface as shown in FIG. 1 so as to be folded through the tab portions. Arranged. In order to prevent the current collector from being damaged by the fastening pressure when the bolt is fastened, a titanium plate having a thickness of 2 mm and a width of 15 mm is disposed between the uppermost layer and the lowermost layer of the laminate and the bolt head, respectively. did. Thus, the laminated body which is a liquid-permeable type capacitor was fastened and fixed.

  Then, the obtained liquid-permeable capacitor was accommodated in a resin container. The container had a substantially rectangular parallelepiped shape with an inner shape of 170 mm in length, 70 mm in width, and 50 mm in height, and was provided with a liquid supply path having a diameter of 9 mm and a drainage path having a diameter of 9 mm. Moreover, the terminal of the two electrodes electrically connected with the titanium volt | bolt of the liquid-permeable type capacitor accommodated in the container was distribute | arranged to the top surface of the container. A deionized liquid production apparatus was manufactured by enclosing a liquid-flowing type capacitor in a container. Then, the negative electrode side and the positive electrode side of the DC power source were respectively connected to the terminals exposed to the outside.

  Then, about 1000 μS / cm saline was passed through the obtained deionized liquid production apparatus at a flow rate of 100 ml / min. And electric power was supplied to the terminal of each electrode from DC power supply. The power was supplied by constant current and constant voltage control (CC-CV) with a voltage upper limit of 1.5 V and a current upper limit of 20 A. In addition, in order to regenerate the activated carbon sheet, the polarity of the DC power source connected to the terminal was periodically reversed. Specifically, the polarity was reversed with a cycle of 180 seconds at the time of adsorption and 60 seconds at the time of desorption as one cycle, and this cycle was repeated for a plurality of cycles. The change in current and voltage plotted against time (seconds) is shown in the graph of FIG.

The electrical conductivity of the treated water discharged from the deionized liquid production device was measured for each predetermined amount of water flow, and the ion removal rate was calculated from the electrical conductivity of the saline solution of the raw water and the electrical conductivity of the treated water. . Specifically, the electrical conductivity (μS / cm) of the water supplied to the deionized liquid production apparatus and the electrical conductivity (μS / cm) of the water discharged from the deionized liquid production apparatus are measured, Was used to calculate the ion removal rate.
Ion removal rate (%) = (Electric conductivity of feed water−Electric conductivity of discharged water) / Electric conductivity of discharged water × 100
In addition, the electrical conductivity of the water discharged | emitted at the time of adsorption | suction falls, and the electrical conductivity of the water discharged | emitted at the time of desorption increases. The amount of adsorption becomes maximum at the first cycle and gradually decreases with each cycle. The adsorption amount at the 10th cycle in which the balance between adsorption and desorption was stable was treated as the adsorption amount of the cell. The change in electrical conductivity plotted against time (seconds) is shown in the graph of FIG. The average removal rate was calculated to be 84%. The results are shown in Table 1.

[Examples 2 to 4]
The characteristics of the deionized liquid production apparatus were evaluated in the same manner as in Example 1 except that water was passed at a flow rate of 250 ml / min, 400 ml / min, or 1000 ml / min instead of water flow at a flow rate of 100 ml / min. The results are shown in Table 1.

[Examples 5 to 8]
Instead of forming a laminated body having a 10-cell capacitor structure, a laminated body having a 20-cell capacitor structure in which the respective layers are laminated in the same order is formed, and a liquid passing type capacitor and a deionized liquid manufacturing apparatus are produced. Evaluated the characteristics of the deionized liquid production apparatus in the same manner as in Examples 1 to 4. The results are shown in Table 1.

[Comparative Examples 1-8]
The characteristics of the deionized liquid production apparatus were evaluated in the same manner as in Examples 1 to 8, except that a liquid-permeable capacitor and a deionized liquid production apparatus were prepared without disposing a titanium foil between the tab portions. The results are shown in Table 1.

  From FIG. 8 in which the results of Examples 1 to 4 and Comparative Examples 1 to 4 and the results of Examples 5 to 8 and Comparative Examples 5 to 8 are plotted, the same number of cells is passed at the same water flow rate. In operation, it can be seen that the example in which the titanium foil is disposed in the tab portion has a significantly higher average ion removal rate than the comparative example. In particular, when the water flow rate is 400 mL / min or less, it can be seen that as the water flow rate increases, the improvement in the average removal rate of ions by placing the titanium foil becomes more significant. Such an improvement in the average removal rate is considered to be due to the electrical conductivity being improved by arranging the titanium foil to connect the current collector in the direction parallel to the sheet surface.

  The liquid-permeable type capacitor and the deionized liquid production apparatus of the present invention are used for various applications that require desalting treatment. Specifically, for example, it can be applied to a wide range of uses such as desalination treatment of tap water and industrial water, seawater desalination equipment, and groundwater beverage application water equipment. In particular, the liquid-flowing capacitor and the deionized water production apparatus of the present invention have a high ion adsorption capacity and can be operated with a small amount of power. Therefore, for example, various water purifiers for treating water from household water supply, more specifically, the removal of washing water provided in local water purifiers, water purifiers, local washing devices provided in toilet seats, etc. It can be preferably used as a salt device.

DESCRIPTION OF SYMBOLS 1,101 1st electrode 1a, 1a '1st collector sheet 1b, 1b' 1st porous carbon sheet 1c Cation exchange membrane 1d, 2d, D Tab part 2,102 2nd electrode 2a 2nd collector sheet 2b Second porous carbon sheet 2c Anion exchange membrane 3 Separator 4 Metal plate 5a, 5b Fastening bolt 6a, 6b, C Conductive sheet 8 Liquid passage hole 10, 120 Cell 15a, 15b Terminal 20 DC power supply 30 Container 31 Supply port 32 Drainage port 100, 110 Flow-through capacitor 200 Deionized liquid production device W1 Liquid to be treated V1, V2 Valve

Claims (9)

A liquid passing type capacitor formed by laminating a plurality of cells,
The cell includes a first electrode, a second electrode, a separator interposed between the first electrode and the second electrode,
The first electrode includes a first current collector sheet made of a graphite sheet, a first porous carbon sheet laminated on the first current collector sheet, and a cation exchange laminated on the first porous carbon sheet. With a membrane,
The second electrode includes a second current collector sheet made of a graphite sheet, a second porous carbon sheet laminated on the second current collector sheet, and an anion exchange membrane laminated on the second porous carbon sheet. And
The cation exchange membrane and the anion exchange membrane are arranged to face each other with the separator interposed therebetween,
At least one of the first current collector sheet and the second current collector sheet has a tab portion that does not face each porous carbon sheet,
At least two or more of the tab portions are electrically connected by a conductive sheet disposed so as to be in contact with the tab portions.   The liquid-permeable capacitor according to claim 1, wherein the conductive sheet is a titanium foil or a titanium alloy foil.   The liquid passing type capacitor according to claim 1 or 2, wherein the plurality of tab portions are fastened by at least one metal bolt.   The liquid-passing capacitor according to claim 3, wherein the metal bolt is a bolt formed of titanium or a titanium alloy.   5. The liquid-type capacitor according to claim 3, wherein the metal bolt has a bolt head, and a metal plate formed of titanium or a titanium alloy is interposed between the bolt head and the conductive sheet. The liquid-permeable capacitor according to any one of claims 1 to 5, a direct-current power source, and a container that accommodates the liquid-permeable capacitor.
The DC power supply is connected to the first electrode and the second electrode so that the polarities on the positive electrode side and the negative electrode side can be exchanged with each other,
The container includes a liquid supply port for supplying a liquid containing an ionic substance to the liquid flow type capacitor, and a liquid discharge port for discharging the processed liquid from the liquid flow type capacitor. A deionized liquid production apparatus.   The deionized liquid manufacturing apparatus according to claim 6, wherein the voltage of the DC power source is in a range of 1.5 to 2V. A method for producing a deionized liquid using the deionized liquid producing apparatus according to claim 6 or 7,
By supplying a liquid to be treated containing an ionic substance from the liquid supply port while applying a voltage to the first electrode and the second electrode by the DC power supply, ions derived from the ionic substance are supplied to the surface of each electrode. And a first step of discharging the treatment liquid from which the ionic substance has been removed from the drainage port;
By supplying a liquid to be treated containing an ionic substance from the liquid supply port while applying a voltage with the polarity of the positive electrode and the negative electrode of each electrode opposite to that of the first step, the surface of each electrode And a second step of discharging the ion concentrate containing the ions from the drainage port.   The deionization according to claim 8, wherein the first step and the second step are alternately performed so that a ratio of the time of the first step / the time of the second step is 1 to 5. Liquid manufacturing method.