WO2024128196A1 - Diaphragm element, electrolytic cell and gas production method - Google Patents

Diaphragm element, electrolytic cell and gas production method Download PDF

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Publication number
WO2024128196A1
WO2024128196A1 PCT/JP2023/044247 JP2023044247W WO2024128196A1 WO 2024128196 A1 WO2024128196 A1 WO 2024128196A1 JP 2023044247 W JP2023044247 W JP 2023044247W WO 2024128196 A1 WO2024128196 A1 WO 2024128196A1
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Prior art keywords
diaphragm
cathode
gasket
electrolytic
anode
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PCT/JP2023/044247
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French (fr)
Japanese (ja)
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康行 田中
佑亮 則安
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株式会社トクヤマ
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Publication of WO2024128196A1 publication Critical patent/WO2024128196A1/en

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  • the present invention relates to a membrane element, an electrolytic cell, and a gas production method, and more specifically to a membrane element and an electrolytic cell that can be suitably used for electrolytic reactions under pressurized conditions (e.g., electrolysis of alkaline water), and a gas production method using the electrolytic cell.
  • pressurized conditions e.g., electrolysis of alkaline water
  • Alkaline water electrolysis is known as a method for producing hydrogen gas and oxygen gas.
  • a basic aqueous solution (alkaline water) containing dissolved alkali metal hydroxides (e.g. NaOH, KOH, etc.) is used as the electrolyte to electrolyze water, generating hydrogen gas from the cathode and oxygen gas from the anode.
  • alkali metal hydroxides e.g. NaOH, KOH, etc.
  • Known electrolytic cells for alkaline water electrolysis include an anode chamber and a cathode chamber separated by an ion-permeable diaphragm, with the anode placed in the anode chamber and the cathode placed in the cathode chamber.
  • the zero-gap electrolytic cell 900 includes electrolytic elements (electrode chamber units) 910, 910, ... each having a conductive partition wall 911 and a flange portion 912 separating an anode chamber A and a cathode chamber C, an ion-permeable diaphragm 920 disposed between adjacent electrolytic elements 910, 910, a gasket 930, 930 disposed between the diaphragm 920 and the flange portion 912 of the electrolytic element 910 and sandwiching the peripheral portion of the diaphragm 920, an anode 940 held by conductive ribs 913, 913, ...
  • the conductive elastic body 960 presses the flexible cathode 970 against the diaphragm 920 and the anode 940, so that the diaphragm 920 is sandwiched between the adjacent cathodes 970 and anodes 940.
  • Gas generated by the electrolysis of alkaline water is usually distributed commercially in a state compressed to a specified pressure.
  • the pressure inside the electrode chamber is approximately normal pressure
  • the gas recovered from the electrode chamber is also approximately normal pressure, so an external compression device is required to compress the gas recovered from the electrolytic cell to a specified pressure outside the electrolytic cell. If the pressure inside the electrode chamber is higher than normal pressure, the capacity of such an external compression device can be reduced or such an external compression device can be eliminated, which is thought to reduce the cost of gas production.
  • the pressure inside the electrode chamber is increased, the bubbles formed in the electrode liquid by the gas generated inside the electrode chamber become smaller, reducing the resistance between the electrodes, and therefore the electrolysis voltage can be reduced even with the same current density, which is thought to enable energy savings.
  • the electrolyte and/or gas may leak to the outside of the electrolytic cell 900 through the porous diaphragm 920 itself and/or the contact surface between the diaphragm 920 and the gasket 930. Therefore, it is desirable that the peripheral portion of the diaphragm and the contact portion between the diaphragm and the gasket do not communicate with the outside of the electrolytic cell. Nonetheless, a structure that completely houses the diaphragm inside the electrolytic cell creates workability problems in the assembly process of the electrolytic cell.
  • a conventional electrolytic cell 900 can be assembled by vertically standing electrolytic elements 910, 910 to which components other than a diaphragm 920 (a gasket 930, an anode 940, a cathode current collector 950, an elastic body 960, and a cathode 970) are attached (i.e., in the orientation shown on the paper of FIG. 1 ), and sandwiching the held diaphragm 920 between the stood electrolytic elements 910, 910 while temporarily holding the diaphragm 920 in the vertical direction using a separate temporary holding means (e.g., an operator's hand).
  • a separate temporary holding means e.g., an operator's hand
  • the peripheral edge of the diaphragm 920 protrudes slightly from the outer periphery of the electrolytic cell 900.
  • a method of sandwiching a diaphragm temporarily held by a separate temporary holding means between electrolytic elements cannot be adopted. This is because the temporary holding means for the diaphragm interferes with the electrolytic element.
  • the electrolytic element 910 is placed horizontally, and the diaphragm 920 and the adjacent electrolytic element 910 are sequentially placed on the surface of the electrolytic element 910, and when a certain number of elements (usually about 5 to 15 elements) are stacked, the elements are vertically raised and assembled.
  • a certain number of elements usually about 5 to 15 elements
  • the holding force for the diaphragm 920 which has a flexible nature, becomes insufficient, and a defect that a part of the diaphragm 920 slips down easily occurs.
  • the present invention aims to provide a membrane element that can improve the assembly workability of an electrolytic cell suitable for pressurized operation. It also provides an electrolytic cell equipped with the membrane element, and a gas production method using the electrolytic cell.
  • the present invention includes the following embodiments [1] to [5].
  • An ion-permeable membrane having a first surface and a second surface; A gasket that holds a peripheral portion of the diaphragm; a frame-shaped protective member that receives and holds the gasket that sandwiches the diaphragm; Equipped with the protective member includes an electrically insulating frame-shaped base, a frame-shaped cover member, and a plurality of screws;
  • the frame-shaped base body is a receiving portion provided on an inner circumferential side of the base body and receiving the gasket and the cover member; a support portion that projects and extends from the receiving portion toward an inner circumferential side of the base and supports the gasket received in the receiving portion in a direction intersecting with a main surface of the diaphragm, the cover member has a shape and a size that allows it to be received in the receiving portion of the base; the gasket holding the diaphragm therebetween and the cover member are received in the receiving portion of the base, whereby the gas
  • a plurality of stacked electrolytic elements each of the plurality of electrolytic elements including an anode, a conductive partition wall, and a cathode, in the above-mentioned order, and the anode and the cathode are each electrically connected to the partition wall; and a diaphragm element according to [1], disposed between each pair of adjacent electrolytic elements; the plurality of electrolytic elements are stacked such that the anodes of the electrolytic elements appear on the same side of the conductive partition wall; an anode chamber accommodating the anode is defined between the diaphragm of the diaphragm element and one of the electrolytic elements adjacent to the diaphragm element; an electrolytic cell, wherein a cathode chamber accommodating the cathode is defined between the diaphragm of the diaphragm element and another electrolytic element adjacent to the diaphragm element.
  • a method for producing at least hydrogen gas by electrolysis of alkaline water comprising: (a) electrolyzing alkaline water using the electrolytic cell according to claim 2, The step (a) supplying alkaline water as an electrolytic solution to each anode chamber and each cathode chamber of the electrolytic cell; Passing a direct current through the electrolytic cell; recovering hydrogen gas from the cathode chamber;
  • a method for producing gas comprising:
  • step (a) further includes recovering oxygen gas from the anode chamber.
  • step (a) The gas production method described in [3] or [4], wherein in step (a), the pressure inside the anode chamber and/or the cathode chamber is maintained at +20 kPa or more relative to atmospheric pressure.
  • the gasket holding the diaphragm and the cover member are received in the receiving portion of the frame-shaped base, so that the gasket holding the diaphragm is sandwiched between the support portion of the base and the cover member. Then, screws are inserted into the first, second, and third through holes of the cover member, gasket, and diaphragm, respectively, and screwed into the screw holes of the frame-shaped base, so that the gasket holding the diaphragm is fastened by the cover member and the support portion of the frame-shaped base, and the cover member, gasket, and diaphragm are removably fixed to the frame-shaped base.
  • an electrolytic cell can be assembled by sandwiching the diaphragm element of the present invention between electrolytic elements, so that it is possible to improve the assembly workability of an electrolytic cell suitable for pressurized operation.
  • the diaphragm element of the present invention is disposed between each pair of adjacent electrolytic elements. Therefore, the electrolytic cell of the present invention makes it possible to improve the assembly workability of an electrolytic cell suitable for pressurized operation.
  • a certain number of the electrolytic elements usually about 5 to 15 elements
  • the diaphragm is completely contained inside the electrolytic cell, and then these are raised vertically and stacked, there is no defect in that the diaphragm of some of the electrolytic elements slips downward due to insufficient clamping force when raised vertically.
  • the gas production method of the present invention uses the electrolytic cell of the present invention to perform electrolysis, so even when it becomes necessary to replace a diaphragm 10 that has deteriorated with use with a new one, it is possible to reduce the time that the electrolytic cell cannot be operated or to reduce the cost of the replacement work.
  • FIG. 1 is a cross-sectional view illustrating a conventional alkaline water electrolytic cell 900 according to one embodiment.
  • 1A and 1B are diagrams illustrating a diaphragm element 100 according to an embodiment of the present invention, in which (A) is a plan view of the diaphragm element 100, and (B) is a bottom view of the diaphragm element 100.
  • 1A is a plan view of a base 31.
  • FIG. 1A is a plan view of the diaphragm 10.
  • FIG. 2A is a cross-sectional view taken along the line BB of FIG. 2A
  • FIG. FIG. 1 is a cross-sectional view illustrating an electrolytic cell 1000 according to one embodiment of the present invention.
  • FIG. 7 is a view taken along the line BB in FIG. 6.
  • 8(A) is a view showing only the cathode side press frame 62 extracted from Fig. 6.
  • (B) is a cross-sectional view taken along the line BB in Fig. 8(A).
  • 9A is a view showing only the cathode-side insulating member 52 extracted from Fig. 6.
  • (B) is a view taken along the line B-B in Fig. 9A.
  • (C) is a view taken along the line CC in Fig. 9A.
  • 10A is a view of only the cathode end cell 220e extracted from Fig. 6.
  • (B) is a view taken along the line BB in Fig. 10A.
  • (C) is a view taken along the line CC in Fig. 10A. 12A is a view showing only the electrolytic element 200 from Fig. 6.
  • (B) is a view taken along the line B-B in Fig. 12A.
  • (C) is a view taken along the line CC in Fig. 12A. 12A is a view showing only the anode end cell 210e extracted from Fig. 6.
  • (B) is a view taken along the line BB in Fig. 12A.
  • (C) is a view taken along the line CC in Fig. 12A.
  • 14(A) is a view showing only the anode-side insulating member 51 extracted from Fig. 6.
  • (B) is a cross-sectional view taken along the line BB in Fig. 14(A).
  • 14(A) is a view showing only the anode-side press frame 61 extracted from Fig. 6.
  • (B) is a cross-sectional view taken along the line BB in
  • E 1 and/or E 2 for the elements E 1 and E 2 means “E 1 or E 2 , or a combination thereof"
  • the notation "E 1 , ..., E N-1 , and/or E N " for the elements E 1 , ..., E N-1 , or E N , or a combination thereof” is intended to mean.
  • N is an integer of 4 or more
  • M is an integer of 3 or more and less than N
  • FIG. 2 is a diagram for explaining a diaphragm element 100 (hereinafter, sometimes simply referred to as "diaphragm element 100") according to one embodiment of the present invention.
  • FIG. 2(A) is a plan view of the diaphragm element 100
  • FIG. 2(B) is a bottom view of the diaphragm element 100.
  • the diaphragm element 100 includes an ion-permeable diaphragm 10, gaskets 20, 20 (hereinafter, sometimes simply referred to as "gasket 20”) that hold the peripheral portion of the diaphragm 10, and a frame-shaped protective member 30 that holds the gasket 20.
  • the protective member 30 includes an electrically insulating frame-shaped base 31, a frame-shaped cover member 32, and a plurality of screws 33, 33, ... (hereinafter, sometimes simply referred to as "screws 33").
  • FIG. 2(A) shows a first surface 10a of the diaphragm 10
  • FIG. 2(B) shows a second surface 10b of the diaphragm 10.
  • Fig. 2(A) shows a first surface 31fa of the base 31
  • Fig. 2(B) shows a second surface 31fb of the base 31.
  • Fig. 3(A) is a plan view of the base 31
  • Fig. 3(B) is a plan view of the cover member 32
  • Fig. 4(A) is a plan view of the diaphragm 10
  • Fig. 4(B) is a plan view of the gasket 20.
  • Fig. 5(A) is a cross-sectional view taken along line B-B of Fig. 2(A)
  • Fig. 5(B) is an exploded view of Fig. 5(A).
  • the base 31 includes a receiving portion 31a that is provided on the inner circumferential side of the base 31 and that receives the gasket 20 (which sandwiches the diaphragm 10) and the cover member 32, and a support portion 31b that protrudes and extends from the receiving portion 31a toward the inner circumferential side of the base 31 and supports the gasket 20 received in the receiving portion 31a in a direction intersecting the main surface of the diaphragm 10 (the left-right direction on the paper in FIGS. 5(A) and 5(B); hereinafter, this may be referred to as the "stacking direction" ( FIG. 5(B) ).
  • the screw 33 has a shaft portion 33a and a head portion 33b provided at one end of the shaft portion 33a (FIG. 5(B)).
  • the support portion 31b of the base body 31 has a plurality of screw holes 31h, 31h, ... (hereinafter simply referred to as “screw holes 31h”) that are provided to open toward the gasket 20 and can be screwed with the screw 33 (shaft portion 33a) (FIG. 3(A)).
  • the cover member 32 has a plurality of first through holes 32h, 32h, ... (hereinafter simply referred to as "first through holes 32h") that are provided at positions corresponding to the plurality of screw holes 31h of the base body 31 and can insert the screw 33 (shaft portion 33a) (FIG.
  • the opening direction of the screw hole 31h in the support part 31b of the base 31 is not particularly limited and may be either toward the anode side or toward the cathode side.
  • the anode side press frame or the cathode side press frame located at both ends of the electrolytic cell open toward the side to which the tube members (anode liquid supply pipe, cathode liquid supply pipe, anode liquid and gas recovery pipe, and cathode liquid and gas recovery pipe) are connected to the outer surface.
  • the electrolytic cell 1000 according to one embodiment of the present invention shown in FIG.
  • these tube members are connected to the outer surface of the cathode side press frame 62, and the screw hole 31h in the support part 31b of the base 31 opens toward the cathode side press frame 62.
  • the outer surface of the anode side press frame 61 is not joined to these tube members, and is entirely flat.
  • the anode-side press frame 61 having a flat outer surface can be stably placed and then the electrolytic elements can be stacked on top of it.
  • the first through hole 32h has a narrow portion 32ha through which the shaft portion 33a of the screw 33 can be inserted but not the head portion 33b, and a wide portion 32hb having a dimension capable of receiving the head portion 33b of the screw 33 when the shaft portion 33a of the screw 33 is inserted into the narrow portion 32ha and screwed into the screw hole 31h of the base body 31 (FIG. 5B).
  • the gasket 20 has a plurality of second through holes 20h, 20h, ...
  • second through holes 20h through which the shaft portions 33a of the screws 33 can be inserted, which are provided at positions corresponding to the plurality of screw holes 31h of the base body 31 (FIG. 4B).
  • the diaphragm 10 has a plurality of third through holes 10h, 10h, ... (hereinafter, simply referred to as “third through holes 10h”) that are provided at positions corresponding to the plurality of screw holes 31h of the base 31 and through which the shanks 33a of the screws 33 can be inserted (FIG. 4(A)).
  • the lid member 32 has dimensions that enable it to be received in the step between the surface of the base 31 that receives the gasket 20 (with the diaphragm 10 sandwiched) in the receiving portion 31a and the surface of the gasket (FIGS. 2(A), 3(A) and (B), and 5(A) and (B)).
  • the outer periphery of the lid member 32 has approximately the same dimensions as the inner periphery of the receiving portion 31a of the base 31, the inner periphery of the lid member 32 has approximately the same dimensions as the inner periphery of the support portion 31b of the base 31, and the thickness of the lid member 32 in the stacking direction is such that the sum of the thickness of the gaskets 20, 20 sandwiching the diaphragm 10 in the stacking direction and the thickness of the lid member 32 in the stacking direction is approximately the same as the depth of the receiving portion 31a of the base 31 in the stacking direction.
  • the gasket 20 (holding the diaphragm 10) and the cover member 32 are received in the receiving portion 31a of the base 31, so that the gasket 20 (holding the diaphragm 10) is sandwiched and held between the support portion 31b of the base 31 and the cover member 32.
  • each of the multiple screws 33 is inserted through the first through hole 32h of the cover member 32, the second through hole 20h of the gasket 20, and the third through hole 10h of the diaphragm 10, and is screwed into the screw hole 31h of the base 31, so that the gasket 20 holding the diaphragm 10 is fastened by the cover member 32 and the support portion 31b of the base 31, and the cover member 32, the gasket 20, and the diaphragm 10 are detachably fixed to the base 31.
  • any ion-permeable diaphragm that can be used in an electrolytic cell (e.g., an electrolytic cell for alkaline water electrolysis) in which the diaphragm element 100 is used can be used without any particular restrictions.
  • the diaphragm 10 desirably has low gas permeability, low electrical conductivity, and high strength.
  • Examples of the diaphragm 10 include porous diaphragms such as porous membranes made of asbestos or modified asbestos, porous diaphragms using polysulfone-based polymers, cloth using polyphenylene sulfide fibers, fluorine-based porous membranes, and porous membranes using hybrid materials containing both inorganic and organic materials.
  • ion exchange membranes such as fluorine-based ion exchange membranes can also be used as the diaphragm 10.
  • FIG. 5 shows a cross section of the gasket 20.
  • the gasket 20 has a flat shape and holds the peripheral portion of the diaphragm 10, while being sandwiched and held between the support portion 31b of the base 31 and the cover member 32 in the receiving portion 31a of the base 31.
  • the gasket 20 is preferably formed of an elastomer having alkali resistance.
  • Examples of materials for the gasket 20 include elastomers such as natural rubber (NR), styrene butadiene rubber (SBR), chloroprene rubber (CR), butadiene rubber (BR), acrylonitrile-butadiene rubber (NBR), ethylene-propylene rubber (EPT), ethylene-propylene-diene rubber (EPDM), isobutylene-isoprene rubber (IIR), and chlorosulfonated polyethylene rubber (CSM).
  • a layer of an alkali-resistant material may be provided on the surface of the gasket material by coating or other means.
  • the base 31 is preferably electrically insulating against the application of a voltage from the outside.
  • the base 31 is formed from an electrically insulating material.
  • a resin material having alkali resistance and strength to withstand the pressing force applied in the stacking direction can be preferably used.
  • resin materials include rigid polyvinyl chloride resin, polypropylene resin, polyethylene resin, polyetherimide resin, polyphenylene sulfide resin, polybenzimidazole resin, polytetrafluoroethylene resin, tetrafluoroethylene-perfluoroalkylvinylether copolymer resin, tetrafluoroethylene-ethylene copolymer resin, etc.
  • the base 31 comprises a core material made of a metal material and a coating layer of an electrically insulating material that coats the surface of the core material.
  • metal materials forming the core material of the base 31 include rigid metal materials such as simple metals such as iron and stainless steels such as SUS304.
  • electrically insulating material forming the coating layer of the base 31 include the above-mentioned electrically insulating resin materials, as well as elastomers having electrical insulation and alkali resistance.
  • elastomers include natural rubber (NR), styrene butadiene rubber (SBR), chloroprene rubber (CR), butadiene rubber (BR), acrylonitrile-butadiene rubber (NBR), ethylene-propylene rubber (EPT), ethylene-propylene-diene rubber (EPDM), isobutylene-isoprene rubber (IIR), and chlorosulfonated polyethylene rubber (CSM).
  • NR natural rubber
  • SBR styrene butadiene rubber
  • CR chloroprene rubber
  • BR butadiene rubber
  • NBR acrylonitrile-butadiene rubber
  • EPT ethylene-propylene rubber
  • EPDM ethylene-propylene-diene rubber
  • IIR isobutylene-isoprene rubber
  • CSM chlorosulfonated polyethylene rubber
  • a layer of an alkali-resistant material may be provided on the surface of the elastomer by coating or the
  • the lid member 32 may be made of metal or may be formed of an electrically insulating material.
  • the metal material forming the lid member 32 include the same metal material as described above in relation to the base 31.
  • the lid member 32 is formed of an electrically insulating material.
  • a preferred example of the electrically insulating material forming the lid member 32 is the same resin material as described above in relation to the base 31.
  • the lid member 32 includes a core material made of a metal material and a coating layer of an electrically insulating material that coats the surface of the core material.
  • the metal material forming the core material of the lid member 32 include the same rigid metal material as described above in relation to the core material of the base 31.
  • Preferable examples of the electrically insulating material forming the covering layer of the cover member 32 include the same resin materials and elastomers as those described above in relation to the covering layer of the base body 31 .
  • a first electrolytic solution supplying flow hole 31ea and a second electrolytic solution supplying flow hole 31eb are provided as through holes in the lower part of the base 31.
  • a second electrolytic solution-gas recovery flow hole 31ec and a first electrolytic solution-gas recovery flow hole 31ed are provided as through holes in the upper part of the base 31.
  • These through holes, that is, the first and second electrolytic solution supplying flow holes 31ea, 31eb and the first and second electrolytic solution-gas recovery flow holes 31ec, 31ed are provided on the outer periphery side of the receiving part 31a and the supporting part 31b.
  • a first flow groove 31ga and a second flow groove 31gc are provided on the second surface 31fb of the base 31, which are fluidically connected to the electrode chamber facing the second surface 10b of the diaphragm 10.
  • the first flow groove 31ga is in fluid communication with the first electrolytic solution supplying through hole 31ea.
  • the second flow groove 31gc is in fluid communication with the first electrolytic solution-gas recovery through hole 31ed.
  • the diaphragm element 100 When assembling the electrolytic cell, the diaphragm element 100 is stacked with the electrolytic element, so that the first electrolytic solution supplying through hole 31ea constitutes a part of the first electrolytic solution supplying through hole, the second electrolytic solution supplying through hole 31eb constitutes a part of the second electrolytic solution supplying through hole, the second electrolytic solution-gas recovery through hole 31ec constitutes a part of the second electrolytic solution-gas recovery through hole, and the first electrolytic solution-gas recovery through hole 31ed constitutes a part of the first electrolytic solution-gas recovery through hole.
  • the first flow groove 31ga and the second flow groove 31gc are covered by the adjacent electrolytic element or end cell.
  • the covered first flow channel 31ga functions as a flow channel that guides the first electrolytic solution from the first electrolytic solution supply flow channel to the electrode chamber facing the second surface 10b of the diaphragm 10.
  • the covered second flow channel 31gc functions as a flow channel that guides the first electrolytic solution and gas from the electrode chamber facing the second surface 10b of the diaphragm 10 to the first electrolytic solution-gas recovery flow channel.
  • a seal material 31s is provided on the periphery of each of the first electrolytic solution flow hole 31ea and the first electrolytic solution-gas recovery flow hole 31ed, facing at least the first surface 31fa of the base 31.
  • a seal material 31s is also provided on the outer periphery, facing the first surface 31fa.
  • the seal material 31s functions to further improve the sealing property for the electrolytic solution and gas when the electrolytic cell is operated under pressure.
  • the material for the sealing material 31s may be an elastomer that is resistant to the electrolytic solution (e.g., alkaline water) of the electrolytic cell in which the diaphragm element 100 is used.
  • Preferred examples of the elastomer that is resistant to alkali include the elastomers described above in relation to the gasket 20.
  • the diaphragm element 100 is described with reference to a configuration including a sealing material 31s, but the diaphragm element of the present invention is not limited to this configuration.
  • the diaphragm element 100 is described with first and second flow grooves 31ga, 31gc as branch flow paths, but the diaphragm element of the present invention is not limited to this form.
  • the diaphragm element of the present invention is not limited to this form.
  • the gasket 20 holding the diaphragm 10 is fastened by the cover member 32 and the support portion 31b of the frame-shaped base 31 with a total of eight screws 33, and the cover member 32, gasket 20, and diaphragm 10 are removably fixed to the base 31.
  • the diaphragm element of the present invention is not limited to this configuration.
  • the number of screws 33 provided on the diaphragm element 100, and the number of through holes through which the screws 33 are inserted and screw holes into which the screws 33 are screwed can be appropriately changed by a person skilled in the art as necessary.
  • the membrane element of the present invention is not limited to this configuration.
  • Electrolytic cell> Fig. 6 is a cross-sectional view for explaining an electrolytic cell 1000 according to an embodiment of the present invention.
  • the electrolytic cell 1000 is an electrolytic cell for electrolyzing alkaline water. 6 and 7, the top and bottom directions of the paper surface correspond to the vertical top and bottom directions, respectively.
  • the electrolytic cell 1000 includes a plurality of stacked electrolytic elements 200, 200, Each of the electrolytic elements 200 includes an anode 43, a conductive partition wall 41, and a cathode 44, in the above order. and a cathode 44, each electrically connected to a partition wall 41; and a diaphragm element 100 (see FIGS. 2 to 5) disposed between each pair of adjacent electrolytic elements 200, 200.
  • the number of stacked electrolytic elements 200 between the anode end cell 210e and the cathode end cell 220e is not particularly limited, but is usually 10 to 400, and more preferably 50 to 350.
  • the electrolytic elements 200 are stacked such that the anodes 43 of the electrolytic elements 200 appear on the same side of the conductive partition wall 41.
  • an anode chamber A (A2, A3) for accommodating an anode 43 is defined, and between the diaphragm 10 of the diaphragm element 100 and the other electrolytic element 200 adjacent to the diaphragm element 100, A cathode chamber C (C1, C2) for accommodating a cathode 44 is defined therein.
  • Each electrolytic element 200 further includes a flange portion 42 that is provided on the outer periphery of the partition wall 41 and extends on both sides of the partition wall 41 .
  • the electrolytic cell 1000 further includes a conductive partition wall 41, a first flange portion 212e provided on the outer periphery of the partition wall 41 and extending to one side of the partition wall 41, and an anode electrically connected to the partition wall 41.
  • an anode end cell 210e including a conductive partition wall 41 and a second flange portion 222e extending from one side of the partition wall 41; and a cathode end cell 220e including a cathode 44 electrically connected to the partition 41 and defining a cathode chamber C3.
  • 10 defines an anode chamber A (A1) that houses an anode 43.
  • a cathode chamber C (C3) accommodating a cathode 44 is defined between the cathode end cell 220e and the diaphragm 10 of the diaphragm element 100 adjacent to the cathode end cell 220e.
  • the anode 43 is connected to a plurality of conductive ribs 45, 45, . . . (hereinafter, simply referred to as "conductive ribs 45") provided to protrude from the partition wall 41.
  • conductive ribs 45 provided to protrude from the partition wall 41.
  • the cathode 44 is supported by conductive ribs 46, 46, ...
  • the anode end cell 210e is included in an anode end unit 300e.
  • the anode end unit 300e includes an anode side press frame 61, an anode side
  • the cathode end cell 220e is included in a cathode end unit 400e.
  • the cathode end unit 400e is provided with an insulating member 51 and an anode end cell 210e.
  • the cathode end cell 220e is provided in the cathode end unit 400e from the cathode end side of the electrolytic cell (the left side of the drawing in FIG. 6 ).
  • the cathode 220 comprises a cathode press frame 62, a cathode insulating member 52, and a cathode end cell 220e arranged in this order.
  • FIG. 8(A) is a view of only the cathode side press frame 62 extracted from FIG. 6, and FIG. 8(B) is a cross-sectional view taken along the line B-B in FIG. 8(A).
  • the cathode side press frame 62 has a first electrolyte supply flow hole 62b and a second electrolyte supply flow hole 62a, each of which is provided as a through hole in the lower part, and a first electrolyte-gas recovery flow hole 62c and a second electrolyte-gas recovery flow hole 62d, each of which is provided as a through hole in the upper part.
  • the cathode side press frame 62 is a metal member.
  • Figure 9(A) is a view of only the cathode side insulating member 52 extracted from Figure 6, and Figure 9(B) is a view taken along the line B-B of Figure 9(A).
  • the cathode side insulating member 52 has a first electrolyte supply flow hole 52b and a second electrolyte supply flow hole 52a, each of which is provided as a through hole in the lower part of the member, and a first electrolyte-gas recovery flow hole 52c and a second electrolyte-gas recovery flow hole 52d, each of which is provided as a through hole in the upper part of the member.
  • FIG. 9(C) is a view taken along the arrows C-C in FIG. 9(A), and includes a first electrolyte supply hole 52b, a second electrolyte supply hole 52a, a first electrolyte-gas recovery hole 52c, and a second electrolyte-gas recovery hole 52d.
  • the first electrolyte supply hole 52b, the second electrolyte supply hole 52a, the first electrolyte-gas recovery hole 52c, and the second electrolyte-gas recovery hole 52d of the cathode side insulating member 52 are connected to the first electrolyte supply hole 62b, the second electrolyte supply hole 62a, the first electrolyte-gas recovery hole 62c, and the second electrolyte-gas recovery hole 62d of the cathode side press frame 62, respectively.
  • FIG. 10(A) is a view of only the cathode end cell 220e from FIG. 6, FIG. 10(B) is a view taken along the line B-B of FIG. 10(A), and FIG. 10(C) is a view taken along the line C-C of FIG. 10(A).
  • the conductive rib 46 and the cathode 44 are omitted in FIG. 10(C).
  • a cathode liquid supply flow section 25ea and an anode liquid supply flow section 25eb are provided at the bottom of the second flange section 222e of the cathode end cell 220e.
  • an anode liquid and gas recovery flow section 25ec and a cathode liquid and gas recovery flow section 25ed are provided at the top of the second flange section 222e of the cathode end cell 220e.
  • Fig. 11(A) is a view of only the electrolytic element 200 extracted from Fig. 6, Fig. 11(B) is a view taken along the line B-B of Fig. 11(A), and Fig. 11(C) is a view taken along the line C-C of Fig. 11(A).
  • the conductive rib 45 and the anode 43 are omitted in Fig. 11(B).
  • the conductive rib 46 and the cathode 44 are omitted in Fig. 11(C).
  • Figs. 11(C) As shown in Figs.
  • an anolyte supply circulating portion 42eb and a catholyte supply circulating portion 42ea are provided at the lower part of the flange portion 42 of the electrolytic element 200. Furthermore, a cathode liquid and gas recovery circulating portion 42ed and an anolyte and gas recovery circulating portion 42ec are provided at the upper part of the flange portion 42 of the electrolytic element 200.
  • the electrolytic element 200 includes a cathode liquid supply branch flow path 42gb provided in fluid communication with the cathode liquid supply circulating portion 42ea and the cathode chamber C (C1, C2), and cathode liquid is supplied from the second electrolytic solution supply flow path 71, of which the cathode liquid supply circulating portion 42ea constitutes a part, to the cathode chamber C (C1, C2) via the cathode liquid supply branch flow path 42gb.
  • the electrolytic element 200 also includes a cathode liquid and gas recovery branch flow path 42gd provided in fluid communication with the cathode liquid and gas recovery circulating portion 42ed and the cathode chamber C (C1, C2), and the cathode liquid and the gas in the cathode chamber are recovered from the cathode chamber C (C1, C2) to the second electrolytic solution-gas recovery flow path 74, of which the cathode liquid and gas recovery circulating portion 42ed constitutes a part, via the cathode liquid and gas recovery branch flow path 42gd.
  • a cathode liquid and gas recovery branch flow path 42gd provided in fluid communication with the cathode liquid and gas recovery circulating portion 42ed and the cathode chamber C (C1, C2), and the cathode liquid and the gas in the cathode chamber are recovered from the cathode chamber C (C1, C2) to the second electrolytic solution-gas recovery flow path 74, of which the cathode liquid and gas recovery circulating
  • each anode chamber A (A1 to A3), anode liquid is supplied to the anode chamber A (A1 to A3) from the first electrolyte supply flow path 72, of which the first electrolyte supply flow hole 31ea constitutes a part, through the first flow path groove 31ga (Fig. 2 (B)) of the diaphragm element 100.
  • anode liquid and gas in the anode chamber are recovered from the anode chamber A (A1 to A3) to the first electrolyte-gas recovery flow path 73, of which the first electrolyte-gas recovery flow hole 31ed constitutes a part, through the second flow path groove 31gc (Fig. 2 (B)) of the diaphragm element 100.
  • Fig. 12(A) is a view of only the anode end cell 210e extracted from Fig. 6, Fig. 12(B) is a view taken along the line B-B in Fig. 12(A), and Fig. 12(C) is a view taken along the line C-C in Fig. 12(A). However, the conductive rib 45 and the anode 43 are omitted in Fig. 12(B).
  • Fig. 13(A) is a view of only the anode side insulating member 51 extracted from Fig. 6, and Fig. 13(B) is a cross-sectional view taken along the line B-B in Fig. 13(A).
  • the anode side insulating member 51 does not have any through holes communicating with any of the first electrolyte supply flow path 72, the second electrolyte supply flow path 71, the first electrolyte-gas recovery flow path 73, and the second electrolyte-gas recovery flow path 74.
  • Fig. 14(A) is a view of only the anode side press frame 61 extracted from Fig. 6, and Fig. 14(B) is a cross-sectional view taken along the line B-B in Fig. 14(A).
  • the anode side press frame 61 does not have any through holes communicating with any of the first electrolyte supply flow path 72, the second electrolyte supply flow path 71, the first electrolyte-gas recovery flow path 73, and the second electrolyte-gas recovery flow path 74.
  • the anolyte supply flow section 42eb of each electrolytic element 200, the first electrolytic solution supply flow hole 31ea of each diaphragm element 100, and the anolyte supply flow section 25eb of the cathode end cell 220e are in fluid communication with each other to form an integrated anolyte supply flow section 72. Furthermore, the anode liquid and gas recovery flow section 42ec of each electrolytic element 200, the first electrolytic solution-gas recovery flow hole 31ed of each diaphragm element 100, and the anode liquid and gas recovery flow section 25ec of the cathode end cell 220e are fluidly connected to each other to form an integrated anode liquid and gas recovery flow section 73.
  • the cathode liquid supply passage 42ea of each electrolytic element 200, the second electrolytic liquid supply passage hole 31eb of each diaphragm element 100, and the cathode liquid supply passage 25ea of the cathode end cell 220e are fluidly connected to each other to form an integrated cathode liquid supply passage 71. Furthermore, the cathode liquid and gas recovery circulating part 42ed of each electrolytic element 200, the second electrolytic solution-gas recovery circulating part 31ec of each diaphragm element 100, and the cathode liquid and gas recovery circulating part 25ed of the cathode end cell 220e are fluidly connected to each other to form an integrated cathode liquid and gas recovery circulating part 74.
  • a cathode liquid supply pipe 81 that supplies cathode liquid to the cathode liquid supply flow part 71 is connected to the cathode liquid supply flow part 71 via second electrolytic solution supply flow holes 62a, 52a that are provided in the cathode side press frame 62 and the cathode side insulating member 52 so as to communicate with the cathode liquid supply flow part 71 (see FIGS. 6 to 9 ).
  • An anode liquid supply pipe 82 that supplies anode liquid to the anode liquid supply passage 72 is connected to the anode liquid supply passage 72 via first electrolytic solution supply passage holes 62b, 52b that are provided in the cathode side press frame 62 and the cathode side insulating member 52 so as to communicate with the anode liquid supply passage 72 (see FIGS. 6 to 9 ).
  • An anode liquid and gas recovery pipe 83 that recovers the anode liquid and gas from the anode liquid and gas recovery flow part 73 is connected to the anode liquid and gas recovery flow part 73 via first electrolytic solution-gas recovery flow holes 62c, 52c that are provided in the cathode side press frame 62 and the cathode side insulating member 52 so as to communicate with the anode liquid and gas recovery flow part 73 (see FIGS. 6 to 9 ).
  • a cathode liquid and gas recovery pipe 84 that recovers the cathode liquid and gas from the cathode liquid and gas recovery flow part 74 is connected to the cathode liquid and gas recovery flow part 74 via second electrolytic solution-gas recovery flow holes 62d, 52d that are provided in the cathode side press frame 62 and the cathode side insulating member 52 in communication with the cathode liquid and gas recovery flow part 74 (see Figures 6 to 9 ).
  • a rigid conductive material having resistance to the environment in which the electrolytic cell 1000 is operated can be used without any particular limitation, and for example, a metal material such as nickel, iron, etc.; ordinary steel (i.e., low carbon steel and medium carbon steel), carbon steel such as high carbon steel, stainless steel (e.g., SUS304, SUS310, SUS310S, SUS316, SUS316L, etc.) can be preferably used. These metal materials may be nickel-plated to improve corrosion resistance and conductivity.
  • a rigid material having resistance to alkali can be used without any particular limitation, and for example, a metal material such as nickel, iron, etc.; ordinary steel (i.e., low carbon steel and medium carbon steel), carbon steel such as high carbon steel, stainless steel (e.g., SUS304, SUS310, SUS310S, SUS316, SUS316L, etc.).
  • Metal materials such as steels such as Cr, Cu, and Cu may be preferably used. The above metal materials may be nickel-plated to improve corrosion resistance.
  • the partition wall 41 and the flange portion 212e of the anode end cell 210e may be joined by welding, adhesion, or the like, or may be integrally formed of the same material.
  • the partition wall 41 and the flange portion 222e of the cathode end cell 220e may be joined by welding, adhesion, or the like, or may be integrally formed of the same material.
  • the partition wall 41 and the flange portion 42 of each electrolysis element 200 may be joined by welding, adhesion, or the like, or may be integrally formed of the same material.
  • the partition wall 41 and flange portion 212e of the anode end cell 210e are integrally formed from the same conductive material (for example, the above-mentioned metal material)
  • the partition wall 41 and flange portion 222e of the cathode end cell 220e are preferably integrally formed from the same conductive material (for example, the above-mentioned metal material)
  • the partition wall 41 and flange portion 42 of each electrolytic element 200 are preferably integrally formed from the same conductive material (for example, the above-mentioned metal material).
  • any anode that can be used for the anode reaction of the electrolytic cell 1000 (for example, oxygen generation reaction when the electrolytic cell 1000 is an electrolytic cell for alkaline water electrolysis) can be used without any particular restrictions.
  • the anode 43 usually comprises a conductive base material and a catalytic layer that covers the surface of the base material. It is preferable that the catalytic layer is porous.
  • the conductive base material of the anode 43 suitable for the oxygen generation reaction for example, nickel, nickel alloy, nickel iron, vanadium, molybdenum, copper, silver, manganese, platinum group elements, graphite, or chromium, or a combination thereof can be used.
  • a conductive base material made of nickel can be preferably used for the anode 43. It is preferable that the catalytic layer contains nickel as an element.
  • the catalytic layer preferably contains nickel oxide, metallic nickel, or nickel hydroxide, or a combination thereof, and may contain an alloy of nickel and one or more other metals. It is particularly preferable that the catalytic layer is made of metallic nickel.
  • the catalyst layer may further include chromium, molybdenum, cobalt, tantalum, zirconium, aluminum, zinc, a platinum group element, a rare earth element, or a combination thereof. Rhodium, palladium, iridium, ruthenium, or a combination thereof may be further supported on the surface of the catalyst layer as an additional catalyst.
  • the conductive substrate of the anode 43 may be a rigid substrate or a flexible substrate.
  • Examples of the rigid conductive substrate constituting the anode 43 include expanded metal and punched metal.
  • Examples of the flexible conductive substrate constituting the anode 43 include a wire mesh woven (or knitted) with metal wires.
  • the cathode 44 can be any cathode that can be used for the cathode reaction of the electrolytic cell 1000 (for example, hydrogen generation reaction when the electrolytic cell 1000 is an electrolytic cell for alkaline water electrolysis) without any particular restrictions.
  • the cathode 44 usually comprises a conductive base material and a catalyst layer that covers the surface of the base material.
  • the conductive base material of the cathode 44 suitable for the hydrogen generation reaction for example, nickel, nickel alloy, stainless steel, mild steel, nickel alloy, or stainless steel or mild steel with nickel plating on the surface can be preferably used.
  • a catalyst layer made of a precious metal oxide, nickel, cobalt, molybdenum, or manganese, or an oxide thereof, or a precious metal oxide can be preferably used.
  • the conductive base material constituting the cathode 44 may be, for example, a rigid base material or a flexible base material.
  • the rigid conductive base material constituting the cathode 44 include expanded metal, punched metal, etc.
  • examples of the flexible conductive base material constituting the cathode 44 include, for example, a metal mesh woven (or knitted) with metal wires.
  • connection method, shape, number, and arrangement of the conductive rib 46 are not particularly limited.
  • the material for the conductive ribs 45 and 46 can be any rigid conductive material that is resistant to the environment in which the electrolytic cell 1000 is operated (e.g., alkali resistance) and is not particularly limited.
  • metal materials such as nickel, iron, and the like; carbon steels such as ordinary steel (i.e., low carbon steel and medium carbon steel), high carbon steel, and stainless steels (e.g., SUS304, SUS310, SUS310S, SUS316, SUS316L, etc.) can be preferably used. These metal materials may be nickel-plated to improve corrosion resistance and electrical conductivity.
  • any insulating member that can be used for electrical insulation between the anode end cell and the anode side press frame and between the cathode end cell and the cathode side press frame in an electrolytic cell can be used without any particular restrictions.
  • Examples of materials for the insulating members 51 and 52 include rigid polyvinyl chloride resin, polypropylene resin, polyethylene resin, nylon resin, polyacetal resin, non-crystalline polyester resin, polyether ether ketone resin, polyetherimide resin, polyphenylene sulfide resin, polybenzimidazole resin, polytetrafluoroethylene resin, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin, tetrafluoroethylene-ethylene copolymer resin, etc.
  • the anode side press frame 61 and the cathode side press frame 62 are fastened by tie rods (not shown) to integrate the insulating members 51 and 52, the electrolytic elements 200, the diaphragm elements 100, the anode end cell 210e, and the cathode end cell 220e arranged between the anode side press frame 61 and the cathode side press frame 62.
  • the press frames 61 and 62 are formed of a metal material having the rigidity to withstand the fastening load. Examples of the metal material constituting the press frames 61 and 62 include carbon steel such as SS400 and stainless steel such as SUS304 and SUS316.
  • the electrolytic cell 1000 is an electrolytic cell suitable for pressurized operation, while having improved assembly workability.
  • the electrolytic cell 1000 also improves the workability of disassembly and reassembly for replacing the diaphragm 10 that has deteriorated with use.
  • An anode terminal is connected to the anode end cell 210e, and a cathode terminal is connected to the cathode end cell 220e. It is also preferable that the anode side press frame 61, the cathode side press frame 62, the cathode liquid supply pipe 81, the anode liquid supply pipe 82, the anode liquid and gas recovery pipe 83, and the cathode liquid and gas recovery pipe 84 are all electrically grounded ( Figures 6 and 7).
  • the pressure inside the cathode chamber is preferably 20 kPa or more higher than atmospheric pressure, more preferably 400 kPa or more higher, and even more preferably 800 kPa or more higher.
  • the upper limit of the pressure inside the cathode chamber depends on the strength of the members constituting the electrolytic cell, but can be, for example, less than atmospheric pressure + 3000 kPa.
  • the pressure inside the cathode chamber be equal to or higher than the above lower limit
  • the compression ratio in the pressure increase step after recovering hydrogen gas from the cathode chamber can be reduced or the pressure increase step can be omitted, reducing equipment costs and enabling the equipment to be space-saving and energy-saving as a whole.
  • the electrolysis voltage can be reduced. This is thought to be due to the fact that the size of the bubbles generated in the cathode chamber becomes smaller, thereby reducing the bubble resistance between the anode and cathode.
  • the compression ratio in the pressure increase step after oxygen gas is recovered from the anode chamber can be reduced or the pressure increase step can be omitted, which further reduces equipment costs and enables further space and energy savings for the entire facility.
  • the pressure inside the anode chamber be equal to or higher than the lower limit, the electrolysis voltage can be reduced. This is thought to be due to the fact that the size of the bubbles generated in the anode chamber becomes smaller, which further reduces the bubble resistance between the anode and cathode.
  • the difference between the pressure inside the cathode chamber and the pressure inside the anode chamber is preferably less than 5.0 kPa, for example, and more preferably less than 1.0 kPa.
  • an electrolytic cell 1000 is given as an example in which the electrode liquid supply pipes/recovery pipes 81-84 are connected to the electrode liquid supply flow paths/recovery flow paths 71-74 through the first to fourth through holes 62a/52a-62d/52d provided in the cathode side press frame 62 and the cathode side insulating member 52, respectively, but the present invention is not limited to this configuration.
  • the electrolytic cell of the present invention can be preferably used, for example, for producing gas by electrolysis of alkaline water.
  • a gas production method according to one embodiment is a method for producing at least hydrogen gas by electrolyzing alkaline water, and includes the step (a) of electrolyzing alkaline water using the electrolytic cell of the present invention.
  • the electrolytic cell in the step (a) for example, the electrolytic cell 1000 described above can be used.
  • the alkaline water any known basic aqueous solution (e.g., a KOH aqueous solution, a NaOH aqueous solution, etc.) used in hydrogen production by alkaline water electrolysis can be used without any particular limitation.
  • Step (a) can be carried out by supplying an electrolyte (alkaline water) to each anode chamber and each cathode chamber of the electrolytic cell of the present invention, and applying a voltage so that a predetermined electrolytic current flows between the anode and cathode (passing a direct current through the electrolytic cell).
  • the gas generated by electrolysis is recovered from each electrode chamber together with the electrolyte, and by performing gas-liquid separation, hydrogen gas can be recovered from the cathode chamber and oxygen gas can be recovered from the anode chamber.
  • the electrolyte separated from the gas by gas-liquid separation can be supplied again to each electrode chamber, with water being replenished as necessary.
  • the pressure inside the cathode chamber is preferably maintained at 20 kPa or more higher than atmospheric pressure.
  • the pressure inside the cathode chamber is preferably 400 kPa or more higher than atmospheric pressure, and more preferably 800 kPa or more higher.
  • the upper limit of the pressure inside the cathode chamber depends on the strength of the members constituting the electrolytic cell, but can be, for example, less than atmospheric pressure + 1000 kPa.
  • the pressure inside the cathode chamber be equal to or higher than the lower limit, the size of the bubbles generated in the cathode chamber becomes smaller, reducing the resistance between the anode and cathode, and therefore making it possible to reduce the electrolysis voltage.
  • the pressure inside the anode chamber is preferably maintained at 20 kPa or more higher than atmospheric pressure.
  • the pressure inside the anode chamber is preferably 400 kPa or more higher than atmospheric pressure, and more preferably 800 kPa or more higher.
  • the upper limit of the pressure inside the anode chamber depends on the strength of the members constituting the electrolytic cell, but can be, for example, less than atmospheric pressure + 1000 kPa.
  • the pressure inside the anode chamber be equal to or higher than the lower limit, the size of the bubbles generated in the anode chamber becomes smaller, which further reduces the resistance between the anode and cathode, and therefore makes it possible to further reduce the electrolysis voltage.
  • the difference between the pressure inside the cathode chamber and the pressure inside the anode chamber is, for example, preferably less than 5.0 kPa, and more preferably less than 1.0 kPa.
  • the difference between the pressure inside the cathode chamber and the pressure inside the anode chamber be less than the above upper limit, it becomes easier to prevent gas from passing through the diaphragm due to the pressure difference between the anode chamber and the cathode chamber and moving from the anode chamber to the cathode chamber or from the cathode chamber to the anode chamber, and to prevent the diaphragm from being damaged due to the pressure difference between the anode chamber and the cathode chamber.
  • the electrolytic cell of the present invention has improved assembly workability, so that even when it becomes necessary to replace a diaphragm 10 that has deteriorated with use with a new diaphragm 10, it is possible to reduce the time during which the electrolytic cell cannot be operated or to reduce the cost of the replacement work.
  • the electrolytic cell of the present invention also has improved resistance to pressure inside the electrode chamber, and the deterioration of the diaphragm's performance due to the heat and mechanical pressure to which it is subjected is suppressed. Therefore, by electrolyzing alkaline water using the electrolytic cell of the present invention, it is possible to perform electrolysis more safely and efficiently, even under conditions of increased pressure inside the electrode chamber.

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  • Electrolytic Production Of Non-Metals, Compounds, Apparatuses Therefor (AREA)

Abstract

The present invention provides a diaphragm element which is capable of enhancing the assembling workability of an electrolytic cell that is suitable for pressurized operation.　The present invention provides a diaphragm element which is provided with a diaphragm, a gasket which holds the peripheral part of the diaphragm, and a frame-like protective member, wherein: the protective member is provided with a frame-like base material, a frame-like cover member, and a plurality of screws; the base material is provided with a receiving part which is provided on the inner circumferential side of the base material and receives the gasket and the cover member, and a support part which extends so as to protrude from the receiving part toward the inner circumferential side of the base material; the support part is provided with screw holes that can be screwed with the screws; the cover member, the gasket and the diaphragm respectively have first, second and third through holes into which the screws can be inserted; the gasket, which holds the diaphragm, and the cover member are received in the receiving part; and by having the screws inserted into the first to third through holes and screwed with the screw holes, the gasket, which holds the diaphragm, is fastened by the cover member and the support part, and the cover member, the gasket and the diaphragm are affixed to the base material in a detachable manner.

Description

隔膜エレメント、電解槽およびガス製造方法Diaphragm element, electrolytic cell and gas production method
　本発明は、隔膜エレメント、電解槽およびガス製造方法に関し、より詳しくは、加圧条件下での電解反応（例えばアルカリ水の電解）に好適に用いることのできる、隔膜エレメント及び電解槽並びに該電解槽を用いたガス製造方法に関する。 The present invention relates to a membrane element, an electrolytic cell, and a gas production method, and more specifically to a membrane element and an electrolytic cell that can be suitably used for electrolytic reactions under pressurized conditions (e.g., electrolysis of alkaline water), and a gas production method using the electrolytic cell.
　水素ガスおよび酸素ガスの製造方法として、アルカリ水電解法が知られている。アルカリ水電解法においては、アルカリ金属水酸化物（例えばＮａＯＨ、ＫＯＨ等。）が溶解した塩基性の水溶液（アルカリ水）を電解液として用いて水を電気分解することにより、陰極から水素ガスが発生し、陽極から酸素ガスが発生する。アルカリ水電解用の電解槽としては、イオン透過性の隔膜によって区画された陽極室および陰極室を備え、陽極室に陽極が、陰極室に陰極がそれぞれ配置された電解槽が知られている。 Alkaline water electrolysis is known as a method for producing hydrogen gas and oxygen gas. In alkaline water electrolysis, a basic aqueous solution (alkaline water) containing dissolved alkali metal hydroxides (e.g. NaOH, KOH, etc.) is used as the electrolyte to electrolyze water, generating hydrogen gas from the cathode and oxygen gas from the anode. Known electrolytic cells for alkaline water electrolysis include an anode chamber and a cathode chamber separated by an ion-permeable diaphragm, with the anode placed in the anode chamber and the cathode placed in the cathode chamber.
国際公開２０１３／１９１１４０号公報International Publication No. 2013/191140 特開２００２－３３２５８６号公報JP 2002-332586 A 特許第４４５３９７３号公報Patent No. 4453973 国際公開２０１４／１７８３１７号公報International Publication No. 2014/178317 特許第６０９３３５１号公報Japanese Patent No. 6093351 特開２０１５－１１７４１７号公報JP 2015-117417 A 国際公開２０１９／１８８２６１号公報International Publication No. 2019/188261
　図１は、一の実施形態に係る従来のアルカリ水電解槽９００を模式的に説明する部分断面図である。ゼロギャップ型電解槽９００は、陽極室Ａと陰極室Ｃとを隔てる導電性の隔壁９１１及びフランジ部９１２を備える電解エレメント（極室ユニット）９１０、９１０、…と、隣接する電解エレメント９１０、９１０の間に配置されたイオン透過性の隔膜９２０と、隔膜９２０と電解エレメント９１０のフランジ部９１２との間に配置され、隔膜９２０の周縁部を挟み込むガスケット９３０、９３０と、隔壁９１１から立設された導電性のリブ９１３、９１３、…に保持された陽極９４０と、隔壁９１１から立設された導電性のリブ９１４、９１４、…に保持された集電体９５０及び該集電体９５０に接して配置された導電性の弾性体９６０に保持された柔軟な陰極９７０と、を備えている。陰極９７０の周縁部および導電性の弾性体９６０の周縁部は、集電体９５０の周縁部に固定されている。電解槽９００においては、導電性の弾性体９６０が柔軟な陰極９７０を隔膜９２０及び陽極９４０に向けて押し付けることにより、隣接する陰極９７０及び陽極９４０の間に隔膜９２０が挟み込まれている。 1 is a partial cross-sectional view illustrating a conventional alkaline water electrolytic cell 900 according to one embodiment. The zero-gap electrolytic cell 900 includes electrolytic elements (electrode chamber units) 910, 910, ... each having a conductive partition wall 911 and a flange portion 912 separating an anode chamber A and a cathode chamber C, an ion-permeable diaphragm 920 disposed between adjacent electrolytic elements 910, 910, a gasket 930, 930 disposed between the diaphragm 920 and the flange portion 912 of the electrolytic element 910 and sandwiching the peripheral portion of the diaphragm 920, an anode 940 held by conductive ribs 913, 913, ... erected from the partition wall 911, a current collector 950 held by conductive ribs 914, 914, ... erected from the partition wall 911, and a flexible cathode 970 held by a conductive elastic body 960 disposed in contact with the current collector 950. The periphery of the cathode 970 and the periphery of the conductive elastic body 960 are fixed to the periphery of the current collector 950. In the electrolytic cell 900, the conductive elastic body 960 presses the flexible cathode 970 against the diaphragm 920 and the anode 940, so that the diaphragm 920 is sandwiched between the adjacent cathodes 970 and anodes 940.
　アルカリ水の電解によって発生したガスは、通常、所定の圧力まで圧縮された状態で商業的に流通される。極室内部の圧力が略常圧である場合、該極室から回収されるガスも略常圧であるので、電解槽から回収されたガスを電解槽の外部で所定の圧力まで圧縮する外部圧縮装置が必要になる。極室内の圧力が常圧よりも高ければ、そのような外部圧縮装置の能力が低くて済むか、又はそのような外部圧縮装置が不要になり、ガスの製造コストを低減できると考えられる。また極室内の圧力を高めれば、極室内で発生したガスが極液中で形成する気泡が小さくなるので、電極間の抵抗が低減され、したがって電流密度が同一でも電解電圧を低減することができ、省エネルギー化が可能になると考えられる。 Gas generated by the electrolysis of alkaline water is usually distributed commercially in a state compressed to a specified pressure. When the pressure inside the electrode chamber is approximately normal pressure, the gas recovered from the electrode chamber is also approximately normal pressure, so an external compression device is required to compress the gas recovered from the electrolytic cell to a specified pressure outside the electrolytic cell. If the pressure inside the electrode chamber is higher than normal pressure, the capacity of such an external compression device can be reduced or such an external compression device can be eliminated, which is thought to reduce the cost of gas production. Furthermore, if the pressure inside the electrode chamber is increased, the bubbles formed in the electrode liquid by the gas generated inside the electrode chamber become smaller, reducing the resistance between the electrodes, and therefore the electrolysis voltage can be reduced even with the same current density, which is thought to enable energy savings.
　しかしながら、図１に示す従来の電解槽９００において極室内部の圧力を高めるためには、さらなるシール性の向上が望まれる。例えば電解槽９００において、電解液および／またはガスは、多孔質の隔膜９２０それ自体、及び／又は、隔膜９２０とガスケット９３０との接触面を通じて、電解槽９００外部に漏洩し得る。したがって、隔膜の周縁部、及び、隔膜とガスケットとの接触部は、電解槽外部に通じていないことが望ましい。そうではあるが、隔膜を電解槽内部に完全に収容する構造は、電解槽の組み立てプロセスにおいて、作業性の問題を生じさせる。 However, in order to increase the pressure inside the electrode chamber in the conventional electrolytic cell 900 shown in FIG. 1, further improvements in sealing are desired. For example, in the electrolytic cell 900, the electrolyte and/or gas may leak to the outside of the electrolytic cell 900 through the porous diaphragm 920 itself and/or the contact surface between the diaphragm 920 and the gasket 930. Therefore, it is desirable that the peripheral portion of the diaphragm and the contact portion between the diaphragm and the gasket do not communicate with the outside of the electrolytic cell. Nonetheless, a structure that completely houses the diaphragm inside the electrolytic cell creates workability problems in the assembly process of the electrolytic cell.
　従来の電解槽９００は、隔膜９２０以外の構成要素（ガスケット９３０、陽極９４０、陰極集電体９５０、弾性体９６０、陰極９７０）が取り付けられた電解エレメント９１０、９１０を縦に（すなわち図１の紙面通りの姿勢に）起こし、隔膜９２０を別途の仮保持手段（例えば作業者の手）により縦方向に仮保持しながら、該保持された隔膜９２０を、当該起こされた電解エレメント９１０、９１０で挟むことにより、組み立てることができる。組立後の電解槽９００においては、隔膜９２０の周縁部が電解槽９００の外周部から若干はみ出た構造となる。これに対して、隔膜を電解槽内部に完全に収容する構造の電解槽を組み立てる際には、別の仮保持手段で仮保持された隔膜を電解エレメントで挟むやり方は採用できない。隔膜の仮保持手段が電解エレメントと干渉するからである。よって、電解エレメント９１０を水平方向に置き、その面上に隔膜９２０及び隣接させる電解エレメント９１０を順次に載置し、一定数（通常は、５～１５エレメント程度）を積みあげたところで、これを縦に起こして組み入れ積層していく方法等で実施しているが、この方法では、前記縦に起こす際に、柔軟な性状にある隔膜９２０に対する挟持力が足りなくなり、一部が下方へズレ落ちる不良が生じ易かった。
　このように、加圧運転に適した電解槽の組立作業性を向上させることが望まれる。 A conventional electrolytic cell 900 can be assembled by vertically standing electrolytic elements 910, 910 to which components other than a diaphragm 920 (a gasket 930, an anode 940, a cathode current collector 950, an elastic body 960, and a cathode 970) are attached (i.e., in the orientation shown on the paper of FIG. 1 ), and sandwiching the held diaphragm 920 between the stood electrolytic elements 910, 910 while temporarily holding the diaphragm 920 in the vertical direction using a separate temporary holding means (e.g., an operator's hand). In the assembled electrolytic cell 900, the peripheral edge of the diaphragm 920 protrudes slightly from the outer periphery of the electrolytic cell 900. In contrast, when assembling an electrolytic cell having a structure in which the diaphragm is completely housed inside the electrolytic cell, a method of sandwiching a diaphragm temporarily held by a separate temporary holding means between electrolytic elements cannot be adopted. This is because the temporary holding means for the diaphragm interferes with the electrolytic element. Therefore, in the conventional method, the electrolytic element 910 is placed horizontally, and the diaphragm 920 and the adjacent electrolytic element 910 are sequentially placed on the surface of the electrolytic element 910, and when a certain number of elements (usually about 5 to 15 elements) are stacked, the elements are vertically raised and assembled. However, with this method, when the elements are vertically raised, the holding force for the diaphragm 920, which has a flexible nature, becomes insufficient, and a defect that a part of the diaphragm 920 slips down easily occurs.
Thus, it is desirable to improve the ease of assembly of electrolytic cells suitable for pressurized operation.
　本発明は、加圧運転に適した電解槽の組立作業性を高めることが可能な、隔膜エレメントを提供することを課題とする。また、該隔膜エレメントを備える電解槽、及び、該電解槽を用いたガス製造方法を提供する。 The present invention aims to provide a membrane element that can improve the assembly workability of an electrolytic cell suitable for pressurized operation. It also provides an electrolytic cell equipped with the membrane element, and a gas production method using the electrolytic cell.
　本発明は、次の［１］～［５］の形態を包含する。
［１］　第１の面および第２の面を有する、イオン透過性の隔膜と、
　前記隔膜の周縁部を挟持する、ガスケットと、
　前記隔膜を挟持した前記ガスケットを受け入れ保持する、枠状の保護部材と、
を備え、
　前記保護部材は、電気絶縁性の枠状の基体と、枠状の蓋部材と、複数のネジとを備え、
  前記枠状の基体は、
　　該基体の内周側に設けられ、前記ガスケット及び前記蓋部材を受け入れる受容部と、　　
  前記受容部より前記基体の内周側に向けて突出して延在し、前記受容部に受け容れられた前記ガスケットを前記隔膜の主面に交差する方向に支持する支持部と
を備え、
　前記蓋部材は、前記基体の受容部に受け容れられることが可能な形状および寸法を有し、
　前記基体の受容部に、前記隔膜を挟持した前記ガスケット、及び、前記蓋部材が受け容れられることにより、前記隔膜を挟持した前記ガスケットが前記基体の支持部と前記蓋部材との間に挟持され、
　前記枠状の基体の支持部は、前記ガスケットに向けて開口するように設けられた、前記ネジと螺合可能な複数のネジ穴を備え、
　前記蓋部材は、前記枠状の基体の複数のネジ穴に対応する位置に設けられた、前記ネジを挿通可能な複数の第１の貫通孔を備え、
　前記ガスケットは、前記枠状の基体の複数のネジ穴に対応する位置に設けられた、前記ネジを挿通可能な複数の第２の貫通孔を備え、
　前記隔膜は、前記枠状の基体の複数のネジ穴に対応する位置に設けられた、前記ネジを挿通可能な複数の第３の貫通孔を備え、
　前記枠状の基体の複数のネジ穴と、前記蓋部材の複数の第１の貫通孔と、前記ガスケットの複数の第２の貫通孔と、前記隔膜の複数の第３の貫通孔とが、相互に連通し、
　前記複数のネジのそれぞれが、前記蓋部材の第１の貫通孔、前記ガスケットの第２の貫通孔、及び前記隔膜の第３の貫通孔に挿通され、前記枠状の基体のネジ穴に螺合されることにより、前記隔膜を挟持したガスケットが前記蓋部材と前記枠状の基体の支持部とによって締め付けられ、且つ、前記蓋部材、前記ガスケット、及び前記隔膜が前記枠状の基体に着脱可能に固定される、隔膜エレメント。 The present invention includes the following embodiments [1] to [5].
[1] An ion-permeable membrane having a first surface and a second surface;
A gasket that holds a peripheral portion of the diaphragm;
a frame-shaped protective member that receives and holds the gasket that sandwiches the diaphragm;
Equipped with
the protective member includes an electrically insulating frame-shaped base, a frame-shaped cover member, and a plurality of screws;
The frame-shaped base body is
a receiving portion provided on an inner circumferential side of the base body and receiving the gasket and the cover member;
a support portion that projects and extends from the receiving portion toward an inner circumferential side of the base and supports the gasket received in the receiving portion in a direction intersecting with a main surface of the diaphragm,
the cover member has a shape and a size that allows it to be received in the receiving portion of the base;
the gasket holding the diaphragm therebetween and the cover member are received in the receiving portion of the base, whereby the gasket holding the diaphragm therebetween is held between the support portion of the base and the cover member,
the support portion of the frame-shaped base includes a plurality of screw holes that are open toward the gasket and can be screwed into the screws,
the cover member includes a plurality of first through holes through which the screws can be inserted, the first through holes being provided at positions corresponding to the plurality of screw holes in the frame-shaped base,
the gasket includes a plurality of second through holes, through which the screws can be inserted, the second through holes being provided at positions corresponding to the plurality of screw holes of the frame-shaped base,
the diaphragm includes a plurality of third through holes, through which the screws can be inserted, the third through holes being provided at positions corresponding to the plurality of screw holes of the frame-shaped base,
a plurality of screw holes in the frame-shaped base, a plurality of first through holes in the cover member, a plurality of second through holes in the gasket, and a plurality of third through holes in the diaphragm are mutually communicated,
a diaphragm element in which each of the plurality of screws is inserted through a first through hole of the cover member, a second through hole of the gasket, and a third through hole of the diaphragm and screwed into a screw hole of the frame-shaped base, such that the gasket holding the diaphragm is fastened between the cover member and a support portion of the frame-shaped base, and the cover member, the gasket, and the diaphragm are removably fixed to the frame-shaped base.
［２］　積層された複数の電解エレメントであって、前記複数の電解エレメントのそれぞれは、陽極と、導電性の隔壁と、陰極とを上記順に備え、前記陽極および前記陰極はそれぞれ前記隔壁に電気的に接続されている、複数の電解エレメントと、
　隣接する前記電解エレメントの各組の間に配置された、［１］に記載の隔膜エレメントと
を備え、
　前記複数の電解エレメントは、各電解エレメントの陽極が前記導電性の隔壁の同じ側に現れるように積層され、
　前記隔膜エレメントの前記隔膜と、該隔膜エレメントに隣接する一方の電解エレメントとの間に、前記陽極を収容する陽極室が画定され、
　前記隔膜エレメントの前記隔膜と、該隔膜エレメントに隣接する他方の電解エレメントとの間に、前記陰極を収容する陰極室が画定されている、電解槽。 [2] A plurality of stacked electrolytic elements, each of the plurality of electrolytic elements including an anode, a conductive partition wall, and a cathode, in the above-mentioned order, and the anode and the cathode are each electrically connected to the partition wall;
and a diaphragm element according to [1], disposed between each pair of adjacent electrolytic elements;
the plurality of electrolytic elements are stacked such that the anodes of the electrolytic elements appear on the same side of the conductive partition wall;
an anode chamber accommodating the anode is defined between the diaphragm of the diaphragm element and one of the electrolytic elements adjacent to the diaphragm element;
an electrolytic cell, wherein a cathode chamber accommodating the cathode is defined between the diaphragm of the diaphragm element and another electrolytic element adjacent to the diaphragm element.
［３］　アルカリ水の電解により少なくとも水素ガスを製造する方法であって、
　（ａ）請求項２に記載の電解槽を用いてアルカリ水を電解する工程
を含み、
　前記工程（ａ）は、
　　前記電解槽の各陽極室および各陰極室に電解液としてアルカリ水を供給することと、
  前記電解槽に直流電流を通電することと、
　　前記陰極室から水素ガスを回収することと、
を含む、ガス製造方法。 [3] A method for producing at least hydrogen gas by electrolysis of alkaline water, comprising:
(a) electrolyzing alkaline water using the electrolytic cell according to claim 2,
The step (a)
supplying alkaline water as an electrolytic solution to each anode chamber and each cathode chamber of the electrolytic cell;
Passing a direct current through the electrolytic cell;
recovering hydrogen gas from the cathode chamber;
A method for producing gas comprising:
［４］　前記工程（ａ）が、前記陽極室から酸素ガスを回収することをさらに含む、［３］に記載のガス製造方法。 [4] The gas production method described in [3], wherein step (a) further includes recovering oxygen gas from the anode chamber.
［５］　前記工程（ａ）において、前記陽極室および／または前記陰極室内部の圧力が、大気圧に対して＋２０ｋＰａ以上に保たれる、［３］又は［４］に記載のガス製造方法。 [5] The gas production method described in [3] or [4], wherein in step (a), the pressure inside the anode chamber and/or the cathode chamber is maintained at +20 kPa or more relative to atmospheric pressure.
　本発明の隔膜エレメントにおいては、枠状の基体の受容部に、隔膜を挟持したガスケット、及び、蓋部材が受け容れられることにより、隔膜を挟持したガスケットが基体の支持部と蓋部材との間に挟持される。そして、蓋部材、ガスケット、及び隔膜がそれぞれ備える第１、第２、及び第３の貫通孔にネジが挿通され、枠状の基体のネジ穴に螺合されることにより、隔膜を挟持したガスケットが蓋部材と枠状の基体の支持部とによって締め付けられ、且つ、蓋部材、ガスケット、及び隔膜が枠状の基体に着脱可能に固定される。本発明の隔膜エレメントによれば、本発明の隔膜エレメントを電解エレメントで挟むことにより電解槽を組み立てることができるので、加圧運転に適した電解槽の組立作業性を高めることが可能である。 In the diaphragm element of the present invention, the gasket holding the diaphragm and the cover member are received in the receiving portion of the frame-shaped base, so that the gasket holding the diaphragm is sandwiched between the support portion of the base and the cover member. Then, screws are inserted into the first, second, and third through holes of the cover member, gasket, and diaphragm, respectively, and screwed into the screw holes of the frame-shaped base, so that the gasket holding the diaphragm is fastened by the cover member and the support portion of the frame-shaped base, and the cover member, gasket, and diaphragm are removably fixed to the frame-shaped base. According to the diaphragm element of the present invention, an electrolytic cell can be assembled by sandwiching the diaphragm element of the present invention between electrolytic elements, so that it is possible to improve the assembly workability of an electrolytic cell suitable for pressurized operation.
　本発明の電解槽においては、隣接する電解エレメントの各組の間に、本発明の隔膜エレメントが配置される。したがって、本発明の電解槽によれば、加圧運転に適した電解槽の組立作業性を高めることが可能である。特に、前記隔膜が電解槽内部に完全に収容されている構造の電解槽における従来の組立て方法に準じて、上記電解エレメントの一定数（通常は、５～１５エレメント程度）を水平方向に積みあげたところで、これを縦に起こして積層していく方法を実施しても、この縦への起こしの際に、挟持力不足で、一部の電解エレメントにおいて隔膜が下方へズレ落ちる不良が生じない。 In the electrolytic cell of the present invention, the diaphragm element of the present invention is disposed between each pair of adjacent electrolytic elements. Therefore, the electrolytic cell of the present invention makes it possible to improve the assembly workability of an electrolytic cell suitable for pressurized operation. In particular, even if a certain number of the electrolytic elements (usually about 5 to 15 elements) are stacked horizontally in accordance with the conventional assembly method for an electrolytic cell in which the diaphragm is completely contained inside the electrolytic cell, and then these are raised vertically and stacked, there is no defect in that the diaphragm of some of the electrolytic elements slips downward due to insufficient clamping force when raised vertically.
　本発明のガス製造方法は、本発明の電解槽を用いて電解を行うので、使用に伴って劣化した隔膜１０を新たな隔膜１０に交換する作業が必要になった際にも、電解槽を運転できない時間を低減する、又は、交換作業に要する費用を低減することが可能である。 The gas production method of the present invention uses the electrolytic cell of the present invention to perform electrolysis, so even when it becomes necessary to replace a diaphragm 10 that has deteriorated with use with a new one, it is possible to reduce the time that the electrolytic cell cannot be operated or to reduce the cost of the replacement work.
一の実施形態に係る従来のアルカリ水電解槽９００を模式的に説明する断面図である。FIG. 1 is a cross-sectional view illustrating a conventional alkaline water electrolytic cell 900 according to one embodiment. 本発明の一の実施形態に係る隔膜エレメント１００を模式的に説明する図である。（Ａ）隔膜エレメント１００の平面図である。（Ｂ）隔膜エレメント１００の底面図である。1A and 1B are diagrams illustrating a diaphragm element 100 according to an embodiment of the present invention, in which (A) is a plan view of the diaphragm element 100, and (B) is a bottom view of the diaphragm element 100. （Ａ）基体３１の平面図である。（Ｂ）蓋部材３２の平面図である。1A is a plan view of a base 31. FIG. （Ａ）隔膜１０の平面図である。（Ｂ）ガスケット２０の平面図である。1A is a plan view of the diaphragm 10. FIG. （Ａ）図２（Ａ）のＢ－Ｂ断面図である。（Ｂ）図５（Ａ）の分解図である。2A is a cross-sectional view taken along the line BB of FIG. 2A, and FIG. 本発明の一の実施形態に係る電解槽１０００を模式的に説明する断面図である。FIG. 1 is a cross-sectional view illustrating an electrolytic cell 1000 according to one embodiment of the present invention. 図６のＢ－Ｂ矢視図である。7 is a view taken along the line BB in FIG. 6. （Ａ）図６から陰極側プレスフレーム６２のみを抜き出した図である。（Ｂ）図８（Ａ）のＢ－Ｂ矢視断面図である。8(A) is a view showing only the cathode side press frame 62 extracted from Fig. 6. (B) is a cross-sectional view taken along the line BB in Fig. 8(A). （Ａ）図６から陰極側絶縁部材５２のみを抜き出した図である。（Ｂ）図９（Ａ）のＢ－Ｂ矢視図である。（Ｃ）図９（Ａ）のＣ－Ｃ矢視図である。9A is a view showing only the cathode-side insulating member 52 extracted from Fig. 6. (B) is a view taken along the line B-B in Fig. 9A. (C) is a view taken along the line CC in Fig. 9A. （Ａ）図６から陰極エンドセル２２０ｅのみを抜き出した図である。（Ｂ）図１０（Ａ）のＢ－Ｂ矢視図である。（Ｃ）図１０（Ａ）のＣ－Ｃ矢視図である。10A is a view of only the cathode end cell 220e extracted from Fig. 6. (B) is a view taken along the line BB in Fig. 10A. (C) is a view taken along the line CC in Fig. 10A. （Ａ）図６から電解エレメント２００のみを抜き出した図である。（Ｂ）図１２（Ａ）のＢ－Ｂ矢視図である。（Ｃ）図１２（Ａ）のＣ－Ｃ矢視図である。12A is a view showing only the electrolytic element 200 from Fig. 6. (B) is a view taken along the line B-B in Fig. 12A. (C) is a view taken along the line CC in Fig. 12A. （Ａ）図６から陽極エンドセル２１０ｅのみを抜き出した図である。（Ｂ）図１２（Ａ）のＢ－Ｂ矢視図である。（Ｃ）図１２（Ａ）のＣ－Ｃ矢視図である。12A is a view showing only the anode end cell 210e extracted from Fig. 6. (B) is a view taken along the line BB in Fig. 12A. (C) is a view taken along the line CC in Fig. 12A. （Ａ）図６から陽極側絶縁部材５１のみを抜き出した図である。（Ｂ）図１４（Ａ）のＢ－Ｂ矢視断面図である。14(A) is a view showing only the anode-side insulating member 51 extracted from Fig. 6. (B) is a cross-sectional view taken along the line BB in Fig. 14(A). （Ａ）図６から陽極側プレスフレーム６１のみを抜き出した図である。（Ｂ）図１４（Ａ）のＢ－Ｂ矢視断面図である。14(A) is a view showing only the anode-side press frame 61 extracted from Fig. 6. (B) is a cross-sectional view taken along the line BB in Fig. 14(A).
　以下、図面を参照しつつ、本発明の実施の形態について説明する。ただし、本発明はこれらの形態に限定されるものではない。なお、図面は必ずしも正確な寸法を反映したものではない。また図では、一部の符号を省略することがある。本明細書においては特に断らない限り、数値Ａ及びＢについて「Ａ～Ｂ」という表記は「Ａ以上Ｂ以下」を意味するものとする。かかる表記において数値Ｂのみに単位を付した場合には、当該単位が数値Ａにも適用されるものとする。また「又は」及び「若しくは」の語は、特に断りのない限り論理和を意味するものとする。また要素Ｅ１及びＥ２について「Ｅ１及び／又はＥ２」という表記は「Ｅ１若しくはＥ２、又はそれらの組み合わせ」を意味するものとし、要素Ｅ１、…、ＥＮ（Ｎは３以上の整数）について「Ｅ１、…、ＥＮ－１、及び／又はＥＮ」という表記は「Ｅ１、…、ＥＮ－１、若しくはＥＮ、又はそれらの組み合わせ」を意味するものとする。また図Ｎ（Ｎは４以上の整数）において、図３～Ｍ（Ｍは３以上Ｎ未満の整数）に既に表れた要素には図３～Ｍにおける符号と同一の符号を付し、説明を省略することがある。 Hereinafter, the embodiments of the present invention will be described with reference to the drawings. However, the present invention is not limited to these embodiments. The drawings do not necessarily reflect accurate dimensions. In addition, some symbols may be omitted in the drawings. In this specification, unless otherwise specified, the notation "A to B" for the numerical values A and B means "A or more and B or less". In such notation, when a unit is added only to the numerical value B, the unit is also applied to the numerical value A. In addition, the words "or" and "or" mean a logical sum unless otherwise specified. In addition, the notation "E 1 and/or E 2 " for the elements E 1 and E 2 means "E 1 or E 2 , or a combination thereof", and the notation "E 1 , ..., E N-1 , and/or E N " for the elements E 1 , ..., E N-1 , or E N , or a combination thereof" is intended to mean. In addition, in Figure N (N is an integer of 4 or more), elements that already appear in Figures 3 to M (M is an integer of 3 or more and less than N) are given the same symbols as in Figures 3 to M, and descriptions thereof may be omitted.
　＜１．隔膜エレメント＞
　図２は、本発明の一の実施形態に係る隔膜エレメント１００（以下において単に「隔膜エレメント１００」ということがある。）を模式的に説明する図である。図２（Ａ）は隔膜エレメント１００の平面図であり、図２（Ｂ）は隔膜エレメント１００の底面図である。隔膜エレメント１００は、イオン透過性の隔膜１０と、隔膜１０の周縁部を挟持するガスケット２０、２０（以下において単に「ガスケット２０」ということがある。）と、ガスケット２０を保持する枠状の保護部材３０とを備えている。保護部材３０は、電気絶縁性の枠状の基体３１と、枠状の蓋部材３２と、複数のネジ３３、３３、…（以下において単に「ネジ３３」ということがある。）とを備えている。なお図２（Ａ）には隔膜１０の第１の面１０ａが表れており、図２（Ｂ）には隔膜１０の第２の面１０ｂが表れている。
また図２（Ａ）には基体３１の第１の面３１ｆａが表れており、図２（Ｂ）には基体３１の第２の面３１ｆｂが表れている。図３（Ａ）は基体３１の平面図、図３（Ｂ）は蓋部材３２の平面図、図４（Ａ）は隔膜１０の平面図、図４（Ｂ）はガスケット２０の平面図である。図５（Ａ）は図２（Ａ）のＢ－Ｂ断面図であり、図５（Ｂ）は図５（Ａ）の分解図である。基体３１は、基体３１の内周側に設けられ、（隔膜１０を挟持した）ガスケット２０、及び蓋部材３２を受け容れる受容部３１ａと、受容部３１ａより基体３１の内周側に向けて突出して延在し、受容部３１ａに受け容れられたガスケット２０を隔膜１０の主面に交差する方向（図５（Ａ）及び（Ｂ）の紙面左右方向。以下において「積層方向」ということがある。）に支持する支持部３１ｂと、を備えている（図５（Ｂ））。 <1. Diaphragm element>
FIG. 2 is a diagram for explaining a diaphragm element 100 (hereinafter, sometimes simply referred to as "diaphragm element 100") according to one embodiment of the present invention. FIG. 2(A) is a plan view of the diaphragm element 100, and FIG. 2(B) is a bottom view of the diaphragm element 100. The diaphragm element 100 includes an ion-permeable diaphragm 10, gaskets 20, 20 (hereinafter, sometimes simply referred to as "gasket 20") that hold the peripheral portion of the diaphragm 10, and a frame-shaped protective member 30 that holds the gasket 20. The protective member 30 includes an electrically insulating frame-shaped base 31, a frame-shaped cover member 32, and a plurality of screws 33, 33, ... (hereinafter, sometimes simply referred to as "screws 33"). Note that FIG. 2(A) shows a first surface 10a of the diaphragm 10, and FIG. 2(B) shows a second surface 10b of the diaphragm 10.
Also, Fig. 2(A) shows a first surface 31fa of the base 31, and Fig. 2(B) shows a second surface 31fb of the base 31. Fig. 3(A) is a plan view of the base 31, Fig. 3(B) is a plan view of the cover member 32, Fig. 4(A) is a plan view of the diaphragm 10, and Fig. 4(B) is a plan view of the gasket 20. Fig. 5(A) is a cross-sectional view taken along line B-B of Fig. 2(A), and Fig. 5(B) is an exploded view of Fig. 5(A). The base 31 includes a receiving portion 31a that is provided on the inner circumferential side of the base 31 and that receives the gasket 20 (which sandwiches the diaphragm 10) and the cover member 32, and a support portion 31b that protrudes and extends from the receiving portion 31a toward the inner circumferential side of the base 31 and supports the gasket 20 received in the receiving portion 31a in a direction intersecting the main surface of the diaphragm 10 (the left-right direction on the paper in FIGS. 5(A) and 5(B); hereinafter, this may be referred to as the "stacking direction") ( FIG. 5(B) ).
　ネジ３３は、軸部３３ａと、軸部３３ａの一方の端部に設けられた頭部３３ｂとを備える（図５（Ｂ））。基体３１の支持部３１ｂは、ガスケット２０に向けて開口するように設けられた、ネジ３３（の軸部３３ａ）と螺合可能な複数のネジ穴３１ｈ、３１ｈ、…（以下において単に「ネジ穴３１ｈ」ということがある。）を備える（図３（Ａ））。蓋部材３２は、基体３１の複数のネジ穴３１ｈに対応する位置に設けられた、ネジ３３（の軸部３３ａ）を挿通可能な複数の第１の貫通孔３２ｈ、３２ｈ、…（以下において単に「第１の貫通孔３２ｈ」ということがある。）を備える（図３（Ｂ））。
　ここで、基体３１の支持部３１ｂにおけるネジ穴３１ｈの開口方向は、陽極側に向いてでも、陰極側に向いてでも特に制限はない。電解槽の組立作業性の良さを勘案すれば、電解槽両端に位置する、陽極側プレスフレームまたは陰極側プレスフレームにおいて、その外面に、管部材（陽極液供給管、陰極液供給管、陽極液・ガス回収管、及び陰極液・ガス回収管）が接続されている方に向かって開口しているのがより好ましい。具体的には、後述する図６に示される、本発明の一実施形態に係る電解槽１０００であれば、これら管部材は陰極側プレスフレーム６２の外面に接続されており、基体３１の支持部３１ｂのネジ穴３１ｈは、該陰極側プレスフレーム６２に向かって開口している。換言すれば、陽極側プレスフレーム６１では、その外面にはこれら管部材が接合されておらず、全面平たんになる。この場合、前記電解槽１０００の組立てでは、陽極エンドユニット３００ｅに隣接する付近の電解エレメントの前記水平方向の積み上げにおいて、斯様に外面が平坦な陽極側プレスフレーム６１を安定に載置してから、その上に上記電解エレメントを積み重ねることができる。しかも、この方向に、電解エレメントを積み上げていくのであれば、基体３１において支持部３１ｂのネジ穴３１ｈは上向き開口になり、ネジ３３による、ネジ穴３１ｈへの締め付け操作が容易になる。
　なお第１の貫通孔３２ｈは、ネジ３３の軸部３３ａを挿通可能だが頭部３３ｂは通さない細部３２ｈａと、ネジ３３の軸部３３ａが細部３２ｈａに挿通され且つ基体３１のネジ穴３１ｈと螺合された際にネジ３３の頭部３３ｂを受け容れることが可能な寸法を有する広部３２ｈｂとを備える（図５（Ｂ））。ガスケット２０は、基体３１の複数のネジ穴３１ｈに対応する位置に設けられた、ネジ３３の軸部３３ａを挿通可能な複数の第２の貫通孔２０ｈ、２０ｈ、…（以下において単に「第２の貫通孔２０ｈ」ということがある。）を備える（図４（Ｂ））。隔膜１０は、基体３１の複数のネジ穴３１ｈに対応する位置に設けられた、ネジ３３の軸部３３ａを挿通可能な複数の第３の貫通孔１０ｈ、１０ｈ、…（以下において単に「第３の貫通孔１０ｈ」ということがある。）を備える（図４（Ａ））。隔膜１０を挟持したガスケット２０、及び蓋部材３２が基体３１の受容部３１ａに受け容れられたとき、基体３１のネジ穴３１ｈと、蓋部材３２の第１の貫通孔３２ｈと、ガスケット２０の第２の貫通孔２０ｈと、隔膜１０の第３の貫通孔１０ｈとは、相互に連通する（図５（Ａ）及び（Ｂ））。 The screw 33 has a shaft portion 33a and a head portion 33b provided at one end of the shaft portion 33a (FIG. 5(B)). The support portion 31b of the base body 31 has a plurality of screw holes 31h, 31h, ... (hereinafter simply referred to as "screw holes 31h") that are provided to open toward the gasket 20 and can be screwed with the screw 33 (shaft portion 33a) (FIG. 3(A)). The cover member 32 has a plurality of first through holes 32h, 32h, ... (hereinafter simply referred to as "first through holes 32h") that are provided at positions corresponding to the plurality of screw holes 31h of the base body 31 and can insert the screw 33 (shaft portion 33a) (FIG. 3(B)).
Here, the opening direction of the screw hole 31h in the support part 31b of the base 31 is not particularly limited and may be either toward the anode side or toward the cathode side. In consideration of ease of assembly of the electrolytic cell, it is more preferable that the anode side press frame or the cathode side press frame located at both ends of the electrolytic cell open toward the side to which the tube members (anode liquid supply pipe, cathode liquid supply pipe, anode liquid and gas recovery pipe, and cathode liquid and gas recovery pipe) are connected to the outer surface. Specifically, in the electrolytic cell 1000 according to one embodiment of the present invention shown in FIG. 6 described later, these tube members are connected to the outer surface of the cathode side press frame 62, and the screw hole 31h in the support part 31b of the base 31 opens toward the cathode side press frame 62. In other words, the outer surface of the anode side press frame 61 is not joined to these tube members, and is entirely flat. In this case, in assembling the electrolytic cell 1000, in stacking the electrolytic elements in the horizontal direction near the anode end unit 300e, the anode-side press frame 61 having a flat outer surface can be stably placed and then the electrolytic elements can be stacked on top of it. Moreover, if the electrolytic elements are stacked in this direction, the screw holes 31h of the support parts 31b in the base 31 open upward, making it easier to tighten the screws 33 into the screw holes 31h.
The first through hole 32h has a narrow portion 32ha through which the shaft portion 33a of the screw 33 can be inserted but not the head portion 33b, and a wide portion 32hb having a dimension capable of receiving the head portion 33b of the screw 33 when the shaft portion 33a of the screw 33 is inserted into the narrow portion 32ha and screwed into the screw hole 31h of the base body 31 (FIG. 5B). The gasket 20 has a plurality of second through holes 20h, 20h, ... (hereinafter sometimes simply referred to as "second through holes 20h") through which the shaft portions 33a of the screws 33 can be inserted, which are provided at positions corresponding to the plurality of screw holes 31h of the base body 31 (FIG. 4B). The diaphragm 10 has a plurality of third through holes 10h, 10h, ... (hereinafter, simply referred to as "third through holes 10h") that are provided at positions corresponding to the plurality of screw holes 31h of the base 31 and through which the shanks 33a of the screws 33 can be inserted (FIG. 4(A)). When the gasket 20 holding the diaphragm 10 and the cover member 32 are received in the receiving portion 31a of the base 31, the screw holes 31h of the base 31, the first through hole 32h of the cover member 32, the second through hole 20h of the gasket 20, and the third through hole 10h of the diaphragm 10 communicate with each other (FIGS. 5(A) and 5(B)).
　蓋部材３２は、受容部３１ａに（隔膜１０を挟持した）ガスケット２０を受け容れた基体３１の面とガスケットの面との間の段差に受け容れられることが可能な寸法を有している（図２（Ａ）、図３（Ａ）及び（Ｂ）、並びに図５（Ａ）及び（Ｂ））。すなわち、蓋部材３２の外周部は、基体３１の受容部３１ａの内周部と略同一の寸法を有しており、蓋部材３２の内周部は、基体３１の支持部３１ｂの内周部と略同一の寸法を有しており、蓋部材３２の積層方向における厚さは、隔膜１０を挟持したガスケット２０、２０の積層方向の厚さと蓋部材３２の積層方向の厚さとの合計が基体３１の受容部３１ａの積層方向における深さと略同一となるようにされている。図５（Ａ）及び（Ｂ）に示すように、（隔膜１０を挟持した）ガスケット２０、及び蓋部材３２が、基体３１の受容部３１ａに受け容れられることにより、（隔膜１０を挟持した）ガスケット２０が基体３１の支持部３１ｂと蓋部材３２との間に挟まれて保持される。さらに、複数のネジ３３のそれぞれ（の軸部３３ａ）が、蓋部材３２の第１の貫通孔３２ｈ、ガスケット２０の第２の貫通孔２０ｈ、及び隔膜１０の第３の貫通孔１０ｈに挿通され、基体３１のネジ穴３１ｈに螺合されることにより、隔膜１０を挟持したガスケット２０が蓋部材３２と基体３１の支持部３１ｂとによって締め付けられ、且つ、蓋部材３２、ガスケット２０、及び隔膜１０が基体３１に着脱可能に固定される。 The lid member 32 has dimensions that enable it to be received in the step between the surface of the base 31 that receives the gasket 20 (with the diaphragm 10 sandwiched) in the receiving portion 31a and the surface of the gasket (FIGS. 2(A), 3(A) and (B), and 5(A) and (B)). That is, the outer periphery of the lid member 32 has approximately the same dimensions as the inner periphery of the receiving portion 31a of the base 31, the inner periphery of the lid member 32 has approximately the same dimensions as the inner periphery of the support portion 31b of the base 31, and the thickness of the lid member 32 in the stacking direction is such that the sum of the thickness of the gaskets 20, 20 sandwiching the diaphragm 10 in the stacking direction and the thickness of the lid member 32 in the stacking direction is approximately the same as the depth of the receiving portion 31a of the base 31 in the stacking direction. As shown in Fig. 5(A) and (B), the gasket 20 (holding the diaphragm 10) and the cover member 32 are received in the receiving portion 31a of the base 31, so that the gasket 20 (holding the diaphragm 10) is sandwiched and held between the support portion 31b of the base 31 and the cover member 32. Furthermore, each of the multiple screws 33 (shafts 33a) is inserted through the first through hole 32h of the cover member 32, the second through hole 20h of the gasket 20, and the third through hole 10h of the diaphragm 10, and is screwed into the screw hole 31h of the base 31, so that the gasket 20 holding the diaphragm 10 is fastened by the cover member 32 and the support portion 31b of the base 31, and the cover member 32, the gasket 20, and the diaphragm 10 are detachably fixed to the base 31.
　隔膜１０としては、隔膜エレメント１００が用いられる電解槽（例えばアルカリ水電解用の電解槽）に使用可能なイオン透過性の隔膜を特に制限なく用いることができる。隔膜１０は、ガス透過性が低く、電気伝導度が小さく、強度が高いことが望ましい。隔膜１０の例としては、アスベストや変性アスベストからなる多孔質膜、ポリスルホン系ポリマーを用いた多孔質隔膜、ポリフェニレンスルファイド繊維を用いた布、フッ素系多孔質膜、無機系材料と有機系材料との両方を含むハイブリッド材料を用いた多孔質膜等の多孔質隔膜を挙げることができる。またこれらの多孔質隔膜以外にも、フッ素系イオン交換膜等のイオン交換膜を隔膜１０として用いることも可能である。 As the diaphragm 10, any ion-permeable diaphragm that can be used in an electrolytic cell (e.g., an electrolytic cell for alkaline water electrolysis) in which the diaphragm element 100 is used can be used without any particular restrictions. The diaphragm 10 desirably has low gas permeability, low electrical conductivity, and high strength. Examples of the diaphragm 10 include porous diaphragms such as porous membranes made of asbestos or modified asbestos, porous diaphragms using polysulfone-based polymers, cloth using polyphenylene sulfide fibers, fluorine-based porous membranes, and porous membranes using hybrid materials containing both inorganic and organic materials. In addition to these porous diaphragms, ion exchange membranes such as fluorine-based ion exchange membranes can also be used as the diaphragm 10.
　ガスケット２０としては、隔膜エレメント１００が用いられる電解槽（例えばアルカリ水電解用の電解槽）に使用可能なガスケットを特に制限なく用いることができる。図５にはガスケット２０の断面が表れている。ガスケット２０は平坦な形状を有し、隔膜１０の周縁部を保持する一方で、基体３１の受容部３１ａにおいて、基体３１の支持部３１ｂと蓋部材３２との間に挟まれて保持される。ガスケット２０は、耐アルカリ性を有するエラストマーによって形成されていることが好ましい。ガスケット２０の材料の例としては、天然ゴム（ＮＲ）、スチレンブタジエンゴム（ＳＢＲ）、クロロプレンゴム（ＣＲ）、ブタジエンゴム（ＢＲ）、アクリロニトリル－ブタジエンゴム（ＮＢＲ）、エチレン－プロピレンゴム（ＥＰＴ）、エチレン－プロピレン－ジエンゴム（ＥＰＤＭ）、イソブチレン－イソプレンゴム（ＩＩＲ）、クロロスルホン化ポリエチレンゴム（ＣＳＭ）等のエラストマーを挙げることができる。また、アルカリ耐性を有しないガスケット材料を使用する場合、該ガスケット材料の表面に耐アルカリ性を有する材料の層を被覆等により設けてもよい。 As the gasket 20, any gasket that can be used in an electrolytic cell (e.g., an electrolytic cell for alkaline water electrolysis) in which the diaphragm element 100 is used can be used without any particular restrictions. FIG. 5 shows a cross section of the gasket 20. The gasket 20 has a flat shape and holds the peripheral portion of the diaphragm 10, while being sandwiched and held between the support portion 31b of the base 31 and the cover member 32 in the receiving portion 31a of the base 31. The gasket 20 is preferably formed of an elastomer having alkali resistance. Examples of materials for the gasket 20 include elastomers such as natural rubber (NR), styrene butadiene rubber (SBR), chloroprene rubber (CR), butadiene rubber (BR), acrylonitrile-butadiene rubber (NBR), ethylene-propylene rubber (EPT), ethylene-propylene-diene rubber (EPDM), isobutylene-isoprene rubber (IIR), and chlorosulfonated polyethylene rubber (CSM). In addition, when using a gasket material that does not have alkali resistance, a layer of an alkali-resistant material may be provided on the surface of the gasket material by coating or other means.
　基体３１は、外部からの電圧印加に対して電気絶縁性であることが好ましい。一の実施形態において、基体３１は、電気絶縁性の材料により形成される。基体３１を形成する電気絶縁性材料としては、耐アルカリ性を有し積層方向に印加される押圧力に耐える強度を有する樹脂材料を好ましく用いることができ、そのような樹脂材料の好ましい例としては、硬質塩化ビニル樹脂、ポリプロピレン樹脂、ポリエチレン樹脂、ポリエーテルイミド樹脂、ポリフェニレンサルファイド樹脂、ポリベンゾイミダゾール樹脂、ポリテトラフルオロエチレン樹脂、テトラフルオロエチレン－パーフルオロアルキルビニルエーテル共重合体樹脂、テトラフルオロエチレン－エチレン共重合体樹脂等を挙げることができる。他の実施形態において、基体３１は、金属材料からなる芯材と、該芯材の表面を被覆する電気絶縁性材料の被覆層とを備えてなる。基体３１の芯材を形成する金属材料の例としては、例えば鉄等の単体金属やＳＵＳ３０４等のステンレス鋼等の、剛性の金属材料を挙げることができる。また基体３１の被覆層を形成する電気絶縁性材料の好ましい例としては、上記した電気絶縁性の樹脂材料のほか、電気絶縁性および耐アルカリ性を有するエラストマーを挙げることができる。そのようなエラストマーの好ましい例としては、天然ゴム（ＮＲ）、スチレンブタジエンゴム（ＳＢＲ）、クロロプレンゴム（ＣＲ）、ブタジエンゴム（ＢＲ）、アクリロニトリル－ブタジエンゴム（ＮＢＲ）、エチレン－プロピレンゴム（ＥＰＴ）、エチレン－プロピレン－ジエンゴム（ＥＰＤＭ）、イソブチレン－イソプレンゴム（ＩＩＲ）、クロロスルホン化ポリエチレンゴム（ＣＳＭ）等を挙げることができる。また、アルカリ耐性を有しないエラストマーを使用する場合、該エラストマーの表面に耐アルカリ性を有する材料の層を被覆等により設けても良い。 The base 31 is preferably electrically insulating against the application of a voltage from the outside. In one embodiment, the base 31 is formed from an electrically insulating material. As the electrically insulating material forming the base 31, a resin material having alkali resistance and strength to withstand the pressing force applied in the stacking direction can be preferably used. Preferred examples of such resin materials include rigid polyvinyl chloride resin, polypropylene resin, polyethylene resin, polyetherimide resin, polyphenylene sulfide resin, polybenzimidazole resin, polytetrafluoroethylene resin, tetrafluoroethylene-perfluoroalkylvinylether copolymer resin, tetrafluoroethylene-ethylene copolymer resin, etc. In another embodiment, the base 31 comprises a core material made of a metal material and a coating layer of an electrically insulating material that coats the surface of the core material. Examples of metal materials forming the core material of the base 31 include rigid metal materials such as simple metals such as iron and stainless steels such as SUS304. In addition, preferred examples of the electrically insulating material forming the coating layer of the base 31 include the above-mentioned electrically insulating resin materials, as well as elastomers having electrical insulation and alkali resistance. Preferred examples of such elastomers include natural rubber (NR), styrene butadiene rubber (SBR), chloroprene rubber (CR), butadiene rubber (BR), acrylonitrile-butadiene rubber (NBR), ethylene-propylene rubber (EPT), ethylene-propylene-diene rubber (EPDM), isobutylene-isoprene rubber (IIR), and chlorosulfonated polyethylene rubber (CSM). In addition, when using an elastomer that does not have alkali resistance, a layer of an alkali-resistant material may be provided on the surface of the elastomer by coating or the like.
　蓋部材３２は、金属製であってもよく、電気絶縁性の材料により形成されてもよい。蓋部材３２を形成する金属材料の例としては、基体３１に関連して上記説明したものと同様の金属材料を挙げることができる。一の実施形態において、蓋部材３２は電気絶縁性の材料により形成される。蓋部材３２を形成する電気絶縁性材料の好ましい例としては、基体３１に関連して上記説明したものと同様の樹脂材料を挙げることができる。他の実施形態において、蓋部材３２は、金属材料からなる芯材と、該芯材の表面を被覆する電気絶縁性材料の被覆層とを備えてなる。蓋部材３２の芯材を形成する金属材料の例としては、基体３１の芯材に関連して上記説明したものと同様の剛性の金属材料を挙げることができる。
また蓋部材３２の被覆層を形成する電気絶縁性材料の好ましい例としては、基体３１の被覆層に関連して上記説明したものと同様の樹脂材料およびエラストマーを挙げることができる。 The lid member 32 may be made of metal or may be formed of an electrically insulating material. Examples of the metal material forming the lid member 32 include the same metal material as described above in relation to the base 31. In one embodiment, the lid member 32 is formed of an electrically insulating material. A preferred example of the electrically insulating material forming the lid member 32 is the same resin material as described above in relation to the base 31. In another embodiment, the lid member 32 includes a core material made of a metal material and a coating layer of an electrically insulating material that coats the surface of the core material. Examples of the metal material forming the core material of the lid member 32 include the same rigid metal material as described above in relation to the core material of the base 31.
Preferable examples of the electrically insulating material forming the covering layer of the cover member 32 include the same resin materials and elastomers as those described above in relation to the covering layer of the base body 31 .
　再び図２（Ａ）及び（Ｂ）、並びに図３（Ａ）を参照する。基体３１の下部には、第１の電解液供給用流通孔３１ｅａ及び第２の電解液供給用流通孔３１ｅｂが、それぞれ貫通孔として設けられている。基体３１の上部には、第２の電解液－ガス回収用流通孔３１ｅｃ及び第１の電解液－ガス回収用流通孔３１ｅｄが、それぞれ貫通孔として設けられている。これらの貫通孔、すなわち、第１及び第２の電解液供給用流通孔３１ｅａ、３１ｅｂ、並びに第１及び第２の電解液－ガス回収用流通孔３１ｅｃ、３１ｅｄは、受容部３１ａ及び支持部３１ｂの外周側に設けられている。さらに図２（Ｂ）を参照すると、基体３１の第２の面３１ｆｂには、隔膜１０の第２の面１０ｂが面する極室に流体連通する、第１の流路溝３１ｇａ、及び第２の流路溝３１ｇｃが設けられている。第１の流路溝３１ｇａは、第１の電解液供給用流通孔３１ｅａと流体連通している。第２の流路溝３１ｇｃは、第１の電解液－ガス回収用流通孔３１ｅｄと流体連通している。電解槽を組み立てる際、隔膜エレメント１００が電解エレメントと積層されることにより、第１の電解液供給用流通孔３１ｅａは第１の電解液供給流路の一部を構成し、第２の電解液供給用流通孔３１ｅｂは第２の電解液供給流路の一部を構成し、第２の電解液－ガス回収用流通孔３１ｅｃは第２の電解液－ガス回収流路の一部を構成し、第１の電解液－ガス回収用流通孔３１ｅｄは第１の電解液－ガス回収流路の一部を構成する。このとき、第１の流路溝３１ｇａ及び第２の流路溝３１ｇｃは、隣接する電解エレメント又はエンドセルにより蓋をされる。蓋をされた第１の流路溝３１ｇａは、第１の電解液供給流路から隔膜１０の第２の面１０ｂが面する極室に第１の電解液を導く流路として機能する。蓋をされた第２の流路溝３１ｇｃは、隔膜１０の第２の面１０ｂが面する極室から第１の電解液－ガス回収流路に第１の電解液及びガスを導く流路として機能する。
　基体３１の少なくとも第１の面３１ｆａに面して、第１の電解液用流通孔３１ｅａ、第１の電解液－ガス回収用流通孔３１ｅｄのそれぞれの周縁部には、シール材３１ｓが設けられている。また、第１の面３１ｆａに面して、外周部にもシール材３１ｓが設けられている。シール材３１ｓは、電解槽が加圧運転された際の電解液およびガスのシール性をさらに高めるように機能する。
　シール材３１ｓの材料としては、隔膜エレメント１００が用いられる電解槽の電解液（例えばアルカリ水）に対して耐性を有するエラストマーを用いることができる。耐アルカリ性を有するエラストマーの好ましい例としては、ガスケット２０に関連して上記説明したものと同様のエラストマーを挙げることができる。 Referring again to Figs. 2(A) and (B) and Fig. 3(A). A first electrolytic solution supplying flow hole 31ea and a second electrolytic solution supplying flow hole 31eb are provided as through holes in the lower part of the base 31. A second electrolytic solution-gas recovery flow hole 31ec and a first electrolytic solution-gas recovery flow hole 31ed are provided as through holes in the upper part of the base 31. These through holes, that is, the first and second electrolytic solution supplying flow holes 31ea, 31eb and the first and second electrolytic solution-gas recovery flow holes 31ec, 31ed are provided on the outer periphery side of the receiving part 31a and the supporting part 31b. Referring further to Fig. 2(B), a first flow groove 31ga and a second flow groove 31gc are provided on the second surface 31fb of the base 31, which are fluidically connected to the electrode chamber facing the second surface 10b of the diaphragm 10. The first flow groove 31ga is in fluid communication with the first electrolytic solution supplying through hole 31ea. The second flow groove 31gc is in fluid communication with the first electrolytic solution-gas recovery through hole 31ed. When assembling the electrolytic cell, the diaphragm element 100 is stacked with the electrolytic element, so that the first electrolytic solution supplying through hole 31ea constitutes a part of the first electrolytic solution supplying through hole, the second electrolytic solution supplying through hole 31eb constitutes a part of the second electrolytic solution supplying through hole, the second electrolytic solution-gas recovery through hole 31ec constitutes a part of the second electrolytic solution-gas recovery through hole, and the first electrolytic solution-gas recovery through hole 31ed constitutes a part of the first electrolytic solution-gas recovery through hole. At this time, the first flow groove 31ga and the second flow groove 31gc are covered by the adjacent electrolytic element or end cell. The covered first flow channel 31ga functions as a flow channel that guides the first electrolytic solution from the first electrolytic solution supply flow channel to the electrode chamber facing the second surface 10b of the diaphragm 10. The covered second flow channel 31gc functions as a flow channel that guides the first electrolytic solution and gas from the electrode chamber facing the second surface 10b of the diaphragm 10 to the first electrolytic solution-gas recovery flow channel.
A seal material 31s is provided on the periphery of each of the first electrolytic solution flow hole 31ea and the first electrolytic solution-gas recovery flow hole 31ed, facing at least the first surface 31fa of the base 31. In addition, a seal material 31s is also provided on the outer periphery, facing the first surface 31fa. The seal material 31s functions to further improve the sealing property for the electrolytic solution and gas when the electrolytic cell is operated under pressure.
The material for the sealing material 31s may be an elastomer that is resistant to the electrolytic solution (e.g., alkaline water) of the electrolytic cell in which the diaphragm element 100 is used. Preferred examples of the elastomer that is resistant to alkali include the elastomers described above in relation to the gasket 20.
　本発明に関する上記説明では、シール材３１ｓを備える形態の隔膜エレメント１００を参照して説明したが、本発明の隔膜エレメントは当該形態に限定されない。例えば、シール材３１ｓを備えない形態の隔膜エレメントとすることも可能である。 In the above description of the present invention, the diaphragm element 100 is described with reference to a configuration including a sealing material 31s, but the diaphragm element of the present invention is not limited to this configuration. For example, it is also possible to use a diaphragm element without a sealing material 31s.
　本発明に関する上記説明では、分岐流路として第１及び第２の流路溝３１ｇａ、３１ｇｃを備える形態の隔膜エレメント１００を参照して説明したが、本発明の隔膜エレメントは当該形態に限定されない。例えば、分岐流路を備えない形態の隔膜エレメントとすることも可能である。また例えば、第１及び第２の流路溝３１ｇａ、３１ｇｃに代えて、基体３１の内部を通る分岐流路を備える形態の隔膜エレメントとすることも可能である。 In the above explanation of the present invention, the diaphragm element 100 is described with first and second flow grooves 31ga, 31gc as branch flow paths, but the diaphragm element of the present invention is not limited to this form. For example, it is also possible to use a diaphragm element with no branch flow paths. Also, for example, it is also possible to use a diaphragm element with a branch flow path that passes through the inside of the base 31 instead of the first and second flow grooves 31ga, 31gc.
　本発明に関する上記説明では、合計８個のネジ３３により、隔膜１０を挟持したガスケット２０が蓋部材３２と枠状の基体３１の支持部３１ｂとによって締め付けられ、且つ、蓋部材３２、ガスケット２０、及び隔膜１０が基体３１に着脱可能に固定される形態の隔膜エレメント１００を参照して説明したが、本発明の隔膜エレメントは当該形態に限定されない。隔膜エレメント１００が備えるネジ３３の個数、及び、ネジ３３が挿通される貫通孔及びネジ３３が螺合されるネジ穴の数は、必要に応じて当業者が適切に変更できる。 In the above description of the present invention, the gasket 20 holding the diaphragm 10 is fastened by the cover member 32 and the support portion 31b of the frame-shaped base 31 with a total of eight screws 33, and the cover member 32, gasket 20, and diaphragm 10 are removably fixed to the base 31. However, the diaphragm element of the present invention is not limited to this configuration. The number of screws 33 provided on the diaphragm element 100, and the number of through holes through which the screws 33 are inserted and screw holes into which the screws 33 are screwed can be appropriately changed by a person skilled in the art as necessary.
　本発明に関する上記説明では、四角形の隔膜１０を備え、これに対応した形状を有するガスケット２０及び枠状の保護部材３０を備える形態の隔膜エレメント１００を参照して説明したが、本発明の隔膜エレメントは当該形態に限定されない。例えば、円形の隔膜を備え、これに対応した形状のガスケット及び保護部材を備える形態の隔膜エレメントとすることも可能である。 The above description of the present invention has been given with reference to a membrane element 100 having a rectangular membrane 10, a gasket 20 having a corresponding shape, and a frame-shaped protective member 30, but the membrane element of the present invention is not limited to this configuration. For example, it is also possible to have a membrane element having a circular membrane, and a gasket and protective member having a corresponding shape.
　＜２．電解槽＞
　図６は、本発明の一の実施形態に係る電解槽１０００を模式的に説明する断面図である。電解槽１０００は、アルカリ水電解用の電解槽である。図７は、図６のＢ－Ｂ矢視図である。図６及び図７において、紙面上下方向が鉛直上下方向にそれぞれ対応する。図６に示すように、電解槽１０００は、積層された複数の電解エレメント２００、２００、…（以下において単に「電解エレメント２００」ということがある。）であって、複数の電解エレメント２００のそれぞれは、陽極４３と、導電性の隔壁４１と、陰極４４とを上記順に備え、陽極４３および陰極４４はそれぞれ隔壁４１に電気的に接続されている、複数の電解エレメント２００と；隣接する電解エレメント２００、２００の各組の間に配置された、隔膜エレメント１００（図２～５参照。）と、を備えている。ここで、陽極エンドセル２１０ｅ及び陰極エンドセル２２０ｅ間において、電解エレメント２００の積層数は特に制限されるものではないが、通常は１０～４００であり、より好ましくは５０～３５０である。
　複数の電解エレメント２００は、各電解エレメント２００の陽極４３が導電性の隔壁４１の同じ側に現れるように積層されている。隔膜エレメント１００の隔膜１０と、該隔膜エレメント１００に隣接する一方の電解エレメント２００との間に、陽極４３を収容する陽極室Ａ（Ａ２、Ａ３）が画定されているとともに、隔膜エレメント１００の隔膜１０と、該隔膜エレメント１００に隣接する他方の電解エレメント２００との間に、陰極４４を収容する陰極室Ｃ（Ｃ１、Ｃ２）が画定されている。
　各電解エレメント２００は、隔壁４１の外周部に設けられ、隔壁４１の両側に延在するフランジ部４２をさらに備えている。
　電解槽１０００はさらに、導電性の隔壁４１と、隔壁４１の外周部に設けられ、隔壁４１の一方の側に延在する第１のフランジ部２１２ｅと、隔壁４１に電気的に接続された陽極４３とを備え、陽極室Ａ１を画定する、陽極エンドセル２１０ｅと；導電性の隔壁４１と、隔壁４１の外周部に設けられ、隔壁４１の一方の側に延在する第２のフランジ部２２２ｅと、隔壁４１に電気的に接続された陰極４４とを備え、陰極室Ｃ３を画定する、陰極エンドセル２２０ｅと、をさらに備えている。陽極エンドセル２１０ｅと、陽極エンドセル２１０ｅに隣接する隔膜エレメント１００の隔膜１０との間に、陽極４３を収容する陽極室Ａ（Ａ１）が画定されている。また陰極エンドセル２２０ｅと、陰極エンドセル２２０ｅに隣接する隔膜エレメント１００の隔膜１０との間に、陰極４４を収容する陰極室Ｃ（Ｃ３）が画定されている。
　各陽極室Ａ（Ａ１～Ａ３）において、陽極４３は、隔壁４１から突出して設けられた複数の導電リブ４５、４５、…（以下において単に「導電リブ４５」ということがある。）に接続され保持されている。また各陰極室Ｃ（Ｃ１～Ｃ３）において、陰極４４は、隔壁４１から突出して設けられた導電リブ４６、４６、…（以下において単に「導電リブ４６」ということがある。）に接続され保持されている。
　陽極エンドセル２１０ｅは、陽極エンドユニット３００ｅに含まれている。陽極エンドユニット３００ｅは、電解槽の陽極側端部側（図６の紙面右側）から順に配置された、陽極側プレスフレーム６１、陽極側絶縁部材５１、及び陽極エンドセル２１０ｅを備えてなる。陰極エンドセル２２０ｅは、陰極エンドユニット４００ｅに含まれている。陰極エンドユニット４００ｅは、電解槽の陰極側端部側（図６の紙面左側）から順に配置された、陰極側プレスフレーム６２、陰極側絶縁部材５２、及び陰極エンドセル２２０ｅを備えてなる。 <2. Electrolytic cell＞
Fig. 6 is a cross-sectional view for explaining an electrolytic cell 1000 according to an embodiment of the present invention. The electrolytic cell 1000 is an electrolytic cell for electrolyzing alkaline water. 6 and 7, the top and bottom directions of the paper surface correspond to the vertical top and bottom directions, respectively. As shown in FIG. 6, the electrolytic cell 1000 includes a plurality of stacked electrolytic elements 200, 200, Each of the electrolytic elements 200 includes an anode 43, a conductive partition wall 41, and a cathode 44, in the above order. and a cathode 44, each electrically connected to a partition wall 41; and a diaphragm element 100 (see FIGS. 2 to 5) disposed between each pair of adjacent electrolytic elements 200, 200. ) and is equipped with. Here, the number of stacked electrolytic elements 200 between the anode end cell 210e and the cathode end cell 220e is not particularly limited, but is usually 10 to 400, and more preferably 50 to 350.
The electrolytic elements 200 are stacked such that the anodes 43 of the electrolytic elements 200 appear on the same side of the conductive partition wall 41. Between the element 200 and the diaphragm 10 of the diaphragm element 100, an anode chamber A (A2, A3) for accommodating an anode 43 is defined, and between the diaphragm 10 of the diaphragm element 100 and the other electrolytic element 200 adjacent to the diaphragm element 100, A cathode chamber C (C1, C2) for accommodating a cathode 44 is defined therein.
Each electrolytic element 200 further includes a flange portion 42 that is provided on the outer periphery of the partition wall 41 and extends on both sides of the partition wall 41 .
The electrolytic cell 1000 further includes a conductive partition wall 41, a first flange portion 212e provided on the outer periphery of the partition wall 41 and extending to one side of the partition wall 41, and an anode electrically connected to the partition wall 41. an anode end cell 210e including a conductive partition wall 41 and a second flange portion 222e extending from one side of the partition wall 41; and a cathode end cell 220e including a cathode 44 electrically connected to the partition 41 and defining a cathode chamber C3. 10 defines an anode chamber A (A1) that houses an anode 43. Further, a cathode chamber C (C3) accommodating a cathode 44 is defined between the cathode end cell 220e and the diaphragm 10 of the diaphragm element 100 adjacent to the cathode end cell 220e.
In each anode chamber A (A1 to A3), the anode 43 is connected to a plurality of conductive ribs 45, 45, . . . (hereinafter, simply referred to as "conductive ribs 45") provided to protrude from the partition wall 41. In each cathode chamber C (C1 to C3), the cathode 44 is supported by conductive ribs 46, 46, ... (hereinafter, simply referred to as "conductive ribs 46") provided so as to protrude from the partition wall 41. ) and is held in place.
The anode end cell 210e is included in an anode end unit 300e. The anode end unit 300e includes an anode side press frame 61, an anode side The cathode end cell 220e is included in a cathode end unit 400e. The cathode end unit 400e is provided with an insulating member 51 and an anode end cell 210e. The cathode end cell 220e is provided in the cathode end unit 400e from the cathode end side of the electrolytic cell (the left side of the drawing in FIG. 6 ). The cathode 220 comprises a cathode press frame 62, a cathode insulating member 52, and a cathode end cell 220e arranged in this order.
　図８（Ａ）は、図６から陰極側プレスフレーム６２のみを抜き出した図であり、図８（Ｂ）は図８（Ａ）のＢ－Ｂ矢視断面図である。図８（Ｂ）に示すように、陰極側プレスフレーム６２は、その下部にそれぞれ貫通孔として設けられた第１の電解液供給用流通孔６２ｂ及び第２の電解液供給用流通孔６２ａ、並びに、その上部にそれぞれ貫通孔として設けられた第１の電解液－ガス回収用流通孔６２ｃ及び第２の電解液－ガス回収用流通孔６２ｄを備えている。陰極側プレスフレーム６２は金属製の部材である。 FIG. 8(A) is a view of only the cathode side press frame 62 extracted from FIG. 6, and FIG. 8(B) is a cross-sectional view taken along the line B-B in FIG. 8(A). As shown in FIG. 8(B), the cathode side press frame 62 has a first electrolyte supply flow hole 62b and a second electrolyte supply flow hole 62a, each of which is provided as a through hole in the lower part, and a first electrolyte-gas recovery flow hole 62c and a second electrolyte-gas recovery flow hole 62d, each of which is provided as a through hole in the upper part. The cathode side press frame 62 is a metal member.
　図９（Ａ）は、図６から陰極側絶縁部材５２のみを抜き出した図であり、図９（Ｂ）は図９（Ａ）のＢ－Ｂ矢視図である。図９（Ｂ）に示すように、陰極側絶縁部材５２は、その下部にそれぞれ貫通孔として設けられた第１の電解液供給用流通孔５２ｂ及び第２の電解液供給用流通孔５２ａ、並びに、その上部にそれぞれ貫通孔として設けられた第１の電解液－ガス回収用流通孔５２ｃ及び第２の電解液－ガス回収用流通孔５２ｄを備えている。第１の電解液供給用流通孔５２ｂ、第２の電解液供給用流通孔５２ａ、第１の電解液－ガス回収用流通孔５２ｃ及び第２の電解液－ガス回収用流通孔５２ｄのぞれぞれの外周部には、シール材３１ｓが設けられている。図９（Ｃ）は、図９（Ａ）のＣ－Ｃ矢視図であり、第１の電解液供給用流通孔５２ｂ、第２の電解液供給用流通孔５２ａ、第１の電解液－ガス回収用流通孔５２ｃ及び第２の電解液－ガス回収用流通孔５２ｄを備えている。図６において、陰極側絶縁部材５２の第１の電解液供給用流通孔５２ｂ、第２の電解液供給用流通孔５２ａ、第１の電解液－ガス回収用流通孔５２ｃ、及び第２の電解液－ガス回収用流通孔５２ｄは、陰極側プレスフレーム６２の第１の電解液供給用流通孔６２ｂ、第２の電解液供給用流通孔６２ａ、第１の電解液－ガス回収用流通孔６２ｃ、及び第２の電解液－ガス回収用流通孔６２ｄと、それぞれ連通している。 Figure 9(A) is a view of only the cathode side insulating member 52 extracted from Figure 6, and Figure 9(B) is a view taken along the line B-B of Figure 9(A). As shown in Figure 9(B), the cathode side insulating member 52 has a first electrolyte supply flow hole 52b and a second electrolyte supply flow hole 52a, each of which is provided as a through hole in the lower part of the member, and a first electrolyte-gas recovery flow hole 52c and a second electrolyte-gas recovery flow hole 52d, each of which is provided as a through hole in the upper part of the member. A seal material 31s is provided on the outer periphery of each of the first electrolyte supply flow hole 52b, the second electrolyte supply flow hole 52a, the first electrolyte-gas recovery flow hole 52c, and the second electrolyte-gas recovery flow hole 52d. FIG. 9(C) is a view taken along the arrows C-C in FIG. 9(A), and includes a first electrolyte supply hole 52b, a second electrolyte supply hole 52a, a first electrolyte-gas recovery hole 52c, and a second electrolyte-gas recovery hole 52d. In FIG. 6, the first electrolyte supply hole 52b, the second electrolyte supply hole 52a, the first electrolyte-gas recovery hole 52c, and the second electrolyte-gas recovery hole 52d of the cathode side insulating member 52 are connected to the first electrolyte supply hole 62b, the second electrolyte supply hole 62a, the first electrolyte-gas recovery hole 62c, and the second electrolyte-gas recovery hole 62d of the cathode side press frame 62, respectively.
　図１０（Ａ）は、図６から陰極エンドセル２２０ｅのみを抜き出した図であり、図１０（Ｂ）は図１０（Ａ）のＢ－Ｂ矢視図、図１０（Ｃ）は図１０（Ａ）のＣ－Ｃ矢視図である。ただし図１０（Ｃ）において、導電リブ４６及び陰極４４は省略している。図１０（Ｂ）及び（Ｃ）に示すように、陰極エンドセル２２０ｅの第２のフランジ部２２２ｅの下部には、陰極液供給用流通部２５ｅａ及び陽極液供給用流通部２５ｅｂが設けられている。また陰極エンドセル２２０ｅの第２のフランジ部２２２ｅの上部には、陽極液・ガス回収用流通部２５ｅｃ及び陰極液・ガス回収用流通部２５ｅｄが設けられている。 FIG. 10(A) is a view of only the cathode end cell 220e from FIG. 6, FIG. 10(B) is a view taken along the line B-B of FIG. 10(A), and FIG. 10(C) is a view taken along the line C-C of FIG. 10(A). However, the conductive rib 46 and the cathode 44 are omitted in FIG. 10(C). As shown in FIGS. 10(B) and (C), a cathode liquid supply flow section 25ea and an anode liquid supply flow section 25eb are provided at the bottom of the second flange section 222e of the cathode end cell 220e. In addition, an anode liquid and gas recovery flow section 25ec and a cathode liquid and gas recovery flow section 25ed are provided at the top of the second flange section 222e of the cathode end cell 220e.
　図１１（Ａ）は、図６から電解エレメント２００のみを抜き出した図であり、図１１（Ｂ）は図１１（Ａ）のＢ－Ｂ矢視図、図１１（Ｃ）は図１１（Ａ）のＣ－Ｃ矢視図である。ただし図１１（Ｂ）において、導電リブ４５及び陽極４３は省略している。また図１１（Ｃ）において、導電リブ４６及び陰極４４は省略している。図１１（Ｂ）及び（Ｃ）に示すように、電解エレメント２００のフランジ部４２の下部には、陽極液供給用流通部４２ｅｂ及び陰極液供給用流通部４２ｅａが設けられている。また電解エレメント２００のフランジ部４２の上部には、陰極液・ガス回収用流通部４２ｅｄ及び陽極液・ガス回収用流通部４２ｅｃが設けられている。
　図１１（Ａ）及び（Ｃ）に示すように、電解エレメント２００は、陰極液供給用流通部４２ｅａおよび陰極室Ｃ（Ｃ１、Ｃ２）と流体連通して設けられた、陰極液供給用分岐流路４２ｇｂを備え、該陰極液供給用分岐流路４２ｇｂを通じて、陰極液供給用流通部４２ｅａがその一部を構成する第２の電解液供給流路７１から陰極室Ｃ（Ｃ１、Ｃ２）に陰極液が供給される。また電解エレメント２００は、陰極液・ガス回収用流通部４２ｅｄおよび陰極室Ｃ（Ｃ１、Ｃ２）と流体連通して設けられた、陰極液・ガス回収用分岐流路４２ｇｄを備え、該陰極液・ガス回収用分岐流路４２ｇｄを通じて、陰極室Ｃ（Ｃ１、Ｃ２）から陰極液および陰極室中のガスが、陰極液・ガス回収用流通部４２ｅｄがその一部を構成する第２の電解液－ガス回収流路７４に回収される。 Fig. 11(A) is a view of only the electrolytic element 200 extracted from Fig. 6, Fig. 11(B) is a view taken along the line B-B of Fig. 11(A), and Fig. 11(C) is a view taken along the line C-C of Fig. 11(A). However, the conductive rib 45 and the anode 43 are omitted in Fig. 11(B). Furthermore, the conductive rib 46 and the cathode 44 are omitted in Fig. 11(C). As shown in Figs. 11(B) and (C), an anolyte supply circulating portion 42eb and a catholyte supply circulating portion 42ea are provided at the lower part of the flange portion 42 of the electrolytic element 200. Furthermore, a cathode liquid and gas recovery circulating portion 42ed and an anolyte and gas recovery circulating portion 42ec are provided at the upper part of the flange portion 42 of the electrolytic element 200.
11(A) and 11(C), the electrolytic element 200 includes a cathode liquid supply branch flow path 42gb provided in fluid communication with the cathode liquid supply circulating portion 42ea and the cathode chamber C (C1, C2), and cathode liquid is supplied from the second electrolytic solution supply flow path 71, of which the cathode liquid supply circulating portion 42ea constitutes a part, to the cathode chamber C (C1, C2) via the cathode liquid supply branch flow path 42gb. The electrolytic element 200 also includes a cathode liquid and gas recovery branch flow path 42gd provided in fluid communication with the cathode liquid and gas recovery circulating portion 42ed and the cathode chamber C (C1, C2), and the cathode liquid and the gas in the cathode chamber are recovered from the cathode chamber C (C1, C2) to the second electrolytic solution-gas recovery flow path 74, of which the cathode liquid and gas recovery circulating portion 42ed constitutes a part, via the cathode liquid and gas recovery branch flow path 42gd.
　また、各陽極室Ａ（Ａ１～Ａ３）において、隔膜エレメント１００の第１の流路溝３１ｇａ（図２（Ｂ））を通じて、第１の電解液供給用流通孔３１ｅａがその一部を構成する第１の電解液供給流路７２から陽極室Ａ（Ａ１～Ａ３）に陽極液が供給される。各陽極室Ａ（Ａ１～Ａ３）において、隔膜エレメント１００の第２の流路溝３１ｇｃ（図２（Ｂ））を通じて、陽極室Ａ（Ａ１～Ａ３）から陽極液および陽極室中のガスが、第１の電解液－ガス回収用流通孔３１ｅｄがその一部を構成する第１の電解液－ガス回収流路７３に回収される。 Also, in each anode chamber A (A1 to A3), anode liquid is supplied to the anode chamber A (A1 to A3) from the first electrolyte supply flow path 72, of which the first electrolyte supply flow hole 31ea constitutes a part, through the first flow path groove 31ga (Fig. 2 (B)) of the diaphragm element 100. In each anode chamber A (A1 to A3), anode liquid and gas in the anode chamber are recovered from the anode chamber A (A1 to A3) to the first electrolyte-gas recovery flow path 73, of which the first electrolyte-gas recovery flow hole 31ed constitutes a part, through the second flow path groove 31gc (Fig. 2 (B)) of the diaphragm element 100.
　図１２（Ａ）は、図６から陽極エンドセル２１０ｅのみを抜き出した図であり、図１２（Ｂ）は図１２（Ａ）のＢ－Ｂ矢視図、図１２（Ｃ）は図１２（Ａ）のＣ－Ｃ矢視図である。ただし図１２（Ｂ）において、導電リブ４５及び陽極４３は省略している。 Fig. 12(A) is a view of only the anode end cell 210e extracted from Fig. 6, Fig. 12(B) is a view taken along the line B-B in Fig. 12(A), and Fig. 12(C) is a view taken along the line C-C in Fig. 12(A). However, the conductive rib 45 and the anode 43 are omitted in Fig. 12(B).
　図１３（Ａ）は、図６から陽極側絶縁部材５１のみを抜き出した図であり、図１３（Ｂ）は図１３（Ａ）のＢ－Ｂ矢視断面図である。図１３（Ｂ）に示すように、陽極側絶縁部材５１は、第１の電解液供給流路７２、第２の電解液供給流路７１、第１の電解液－ガス回収流路７３、第２の電解液－ガス回収流路７４のいずれと連通する貫通孔も有していない。 Fig. 13(A) is a view of only the anode side insulating member 51 extracted from Fig. 6, and Fig. 13(B) is a cross-sectional view taken along the line B-B in Fig. 13(A). As shown in Fig. 13(B), the anode side insulating member 51 does not have any through holes communicating with any of the first electrolyte supply flow path 72, the second electrolyte supply flow path 71, the first electrolyte-gas recovery flow path 73, and the second electrolyte-gas recovery flow path 74.
　図１４（Ａ）は、図６から陽極側プレスフレーム６１のみを抜き出した図であり、図１４（Ｂ）は図１４（Ａ）のＢ－Ｂ矢視断面図である。図１４（Ｂ）に示すように、陽極側プレスフレーム６１は、第１の電解液供給流路７２、第２の電解液供給流路７１、第１の電解液－ガス回収流路７３、第２の電解液－ガス回収流路７４のいずれと連通する貫通孔も有していない。 Fig. 14(A) is a view of only the anode side press frame 61 extracted from Fig. 6, and Fig. 14(B) is a cross-sectional view taken along the line B-B in Fig. 14(A). As shown in Fig. 14(B), the anode side press frame 61 does not have any through holes communicating with any of the first electrolyte supply flow path 72, the second electrolyte supply flow path 71, the first electrolyte-gas recovery flow path 73, and the second electrolyte-gas recovery flow path 74.
　電解槽１０００において、各電解エレメント２００の陽極液供給用流通部４２ｅｂと、各隔膜エレメント１００の第１の電解液供給用流通孔３１ｅａと、陰極エンドセル２２０ｅの陽極液供給用流通部２５ｅｂとが相互に流体連通して、一体の陽極液供給用流通部７２を形成している。
　また、各電解エレメント２００の陽極液・ガス回収用流通部４２ｅｃと、各隔膜エレメント１００の第１の電解液－ガス回収用流通孔３１ｅｄと、陰極エンドセル２２０ｅの陽極液・ガス回収用流通部２５ｅｃとが相互に流体連通して、一体の陽極液・ガス回収用流通部７３を形成している。
　また、各電解エレメント２００の陰極液供給用流通部４２ｅａと、各隔膜エレメント１００の第２の電解液供給用流通孔３１ｅｂと、陰極エンドセル２２０ｅの陰極液供給用流通部２５ｅａとが相互に流体連通して、一体の陰極液供給用流通部７１を形成している。
　また、各電解エレメント２００の陰極液・ガス回収用流通部４２ｅｄと、各隔膜エレメント１００の第２の電解液－ガス回収用流通部３１ｅｃと、陰極エンドセル２２０ｅの陰極液・ガス回収用流通部２５ｅｄとが相互に流体連通して、一体の陰極液・ガス回収用流通部７４を形成している。 In the electrolytic cell 1000, the anolyte supply flow section 42eb of each electrolytic element 200, the first electrolytic solution supply flow hole 31ea of each diaphragm element 100, and the anolyte supply flow section 25eb of the cathode end cell 220e are in fluid communication with each other to form an integrated anolyte supply flow section 72.
Furthermore, the anode liquid and gas recovery flow section 42ec of each electrolytic element 200, the first electrolytic solution-gas recovery flow hole 31ed of each diaphragm element 100, and the anode liquid and gas recovery flow section 25ec of the cathode end cell 220e are fluidly connected to each other to form an integrated anode liquid and gas recovery flow section 73.
Furthermore, the cathode liquid supply passage 42ea of each electrolytic element 200, the second electrolytic liquid supply passage hole 31eb of each diaphragm element 100, and the cathode liquid supply passage 25ea of the cathode end cell 220e are fluidly connected to each other to form an integrated cathode liquid supply passage 71.
Furthermore, the cathode liquid and gas recovery circulating part 42ed of each electrolytic element 200, the second electrolytic solution-gas recovery circulating part 31ec of each diaphragm element 100, and the cathode liquid and gas recovery circulating part 25ed of the cathode end cell 220e are fluidly connected to each other to form an integrated cathode liquid and gas recovery circulating part 74.
　陰極液供給用流通部７１に陰極液を供給する陰極液供給管８１が、陰極側プレスフレーム６２及び陰極側絶縁部材５２に陰極液供給用流通部７１と連通して設けられた第２の電解液供給用流通孔６２ａ、５２ａを通じて、陰極液供給用流通部７１に接続されている（図６～９参照）。
　陽極液供給用流通部７２に陽極液を供給する陽極液供給管８２が、陰極側プレスフレーム６２及び陰極側絶縁部材５２に陽極液供給用流通部７２と連通して設けられた第１の電解液供給用流通孔６２ｂ、５２ｂを通じて、陽極液供給用流通部７２に接続されている（図６～９参照）。
　陽極液・ガス回収用流通部７３から陽極液およびガスを回収する陽極液・ガス回収管８３が、陰極側プレスフレーム６２及び陰極側絶縁部材５２に陽極液・ガス回収用流通部７３と連通して設けられた第１の電解液－ガス回収用流通孔６２ｃ、５２ｃを通じて、陽極液・ガス回収用流通部７３に接続されている（図６～９参照）。
　陰極液・ガス回収用流通部７４から陰極液およびガスを回収する陰極液・ガス回収管８４が、陰極側プレスフレーム６２及び陰極側絶縁部材５２に陰極液・ガス回収用流通部７４と連通して設けられた第２の電解液－ガス回収用流通孔６２ｄ、５２ｄを通じて、陰極液・ガス回収用流通部７４に接続されている（図６～９参照）。 A cathode liquid supply pipe 81 that supplies cathode liquid to the cathode liquid supply flow part 71 is connected to the cathode liquid supply flow part 71 via second electrolytic solution supply flow holes 62a, 52a that are provided in the cathode side press frame 62 and the cathode side insulating member 52 so as to communicate with the cathode liquid supply flow part 71 (see FIGS. 6 to 9 ).
An anode liquid supply pipe 82 that supplies anode liquid to the anode liquid supply passage 72 is connected to the anode liquid supply passage 72 via first electrolytic solution supply passage holes 62b, 52b that are provided in the cathode side press frame 62 and the cathode side insulating member 52 so as to communicate with the anode liquid supply passage 72 (see FIGS. 6 to 9 ).
An anode liquid and gas recovery pipe 83 that recovers the anode liquid and gas from the anode liquid and gas recovery flow part 73 is connected to the anode liquid and gas recovery flow part 73 via first electrolytic solution-gas recovery flow holes 62c, 52c that are provided in the cathode side press frame 62 and the cathode side insulating member 52 so as to communicate with the anode liquid and gas recovery flow part 73 (see FIGS. 6 to 9 ).
A cathode liquid and gas recovery pipe 84 that recovers the cathode liquid and gas from the cathode liquid and gas recovery flow part 74 is connected to the cathode liquid and gas recovery flow part 74 via second electrolytic solution-gas recovery flow holes 62d, 52d that are provided in the cathode side press frame 62 and the cathode side insulating member 52 in communication with the cathode liquid and gas recovery flow part 74 (see Figures 6 to 9 ).
　導電性の隔壁４１の材質としては、電解槽１０００が運転される際の環境に耐性を有する（例えばアルカリ耐性を有する）剛性の導電性材料を特に制限なく用いることができ、例えばニッケル、鉄等の単体金属；普通鋼（すなわち低炭素鋼および中炭素鋼。）、高炭素鋼等の炭素鋼、ステンレス鋼（例えばＳＵＳ３０４、ＳＵＳ３１０、ＳＵＳ３１０Ｓ、ＳＵＳ３１６、ＳＵＳ３１６Ｌ等。）の等の鋼、等の金属材料を好ましく採用できる。これら金属材料は、耐食性や導電性を向上させるために、ニッケルめっきを施して用いても良い。フランジ部４２、２１２ｅ、及び２２２ｅの材質としては、例えばアルカリ耐性を有する剛性の材料を特に制限なく用いることができ、例えばニッケル、鉄等の単体金属；普通鋼（すなわち低炭素鋼および中炭素鋼。）、高炭素鋼等の炭素鋼、ステンレス鋼（例えばＳＵＳ３０４、ＳＵＳ３１０、ＳＵＳ３１０Ｓ、ＳＵＳ３１６、ＳＵＳ３１６Ｌ等。
）等の鋼、等の金属材料を好ましく採用できる。上記金属材料には、耐食性を向上させるために、ニッケルめっきを施しても良い。陽極エンドセル２１０ｅの隔壁４１とフランジ部２１２ｅとは溶接や接着等で接合されていてもよく、同一の材料で一体に形成されていてもよい。同様に、陰極エンドセル２２０ｅの隔壁４１とフランジ部２２２ｅとは溶接や接着等で接合されていてもよく、同一の材料で一体に形成されていてもよい。各電解エレメント２００の隔壁４１とのフランジ部４２とは溶接や接着等で接合されていてもよく、同一の材料で一体に形成されていてもよい。ただし、極室内部の圧力に対する耐性を高めることが容易である点で、陽極エンドセル２１０ｅの隔壁４１とフランジ部２１２ｅとは同一の導電性材料（例えば上記金属材料。）で一体に形成されていることが好ましく、陰極エンドセル２２０ｅの隔壁４１とフランジ部２２２ｅとは同一の導電性材料（例えば上記金属材料。）で一体に形成されていることが好ましく、各電解エレメント２００の隔壁４１とフランジ部４２とは同一の導電性材料（例えば上記金属材料。）で一体に形成されていることが好ましい。 As the material of the conductive partition 41, a rigid conductive material having resistance to the environment in which the electrolytic cell 1000 is operated (e.g., having resistance to alkali) can be used without any particular limitation, and for example, a metal material such as nickel, iron, etc.; ordinary steel (i.e., low carbon steel and medium carbon steel), carbon steel such as high carbon steel, stainless steel (e.g., SUS304, SUS310, SUS310S, SUS316, SUS316L, etc.) can be preferably used. These metal materials may be nickel-plated to improve corrosion resistance and conductivity. As the material of the flange portions 42, 212e, and 222e, for example, a rigid material having resistance to alkali can be used without any particular limitation, and for example, a metal material such as nickel, iron, etc.; ordinary steel (i.e., low carbon steel and medium carbon steel), carbon steel such as high carbon steel, stainless steel (e.g., SUS304, SUS310, SUS310S, SUS316, SUS316L, etc.).
Metal materials such as steels such as Cr, Cu, and Cu may be preferably used. The above metal materials may be nickel-plated to improve corrosion resistance. The partition wall 41 and the flange portion 212e of the anode end cell 210e may be joined by welding, adhesion, or the like, or may be integrally formed of the same material. Similarly, the partition wall 41 and the flange portion 222e of the cathode end cell 220e may be joined by welding, adhesion, or the like, or may be integrally formed of the same material. The partition wall 41 and the flange portion 42 of each electrolysis element 200 may be joined by welding, adhesion, or the like, or may be integrally formed of the same material. However, in terms of facilitating increasing resistance to pressure inside the electrode chamber, it is preferable that the partition wall 41 and flange portion 212e of the anode end cell 210e are integrally formed from the same conductive material (for example, the above-mentioned metal material), the partition wall 41 and flange portion 222e of the cathode end cell 220e are preferably integrally formed from the same conductive material (for example, the above-mentioned metal material), and the partition wall 41 and flange portion 42 of each electrolytic element 200 are preferably integrally formed from the same conductive material (for example, the above-mentioned metal material).
　陽極４３としては、電解槽１０００の陽極反応（例えば電解槽１０００がアルカリ水電解用の電解槽である場合には、酸素発生反応）に使用可能な陽極を特に制限なく用いることができる。陽極４３は通常、導電性基材と、該基材の表面を被覆する触媒層とを備える。触媒層は多孔質であることが好ましい。酸素発生反応に適した陽極４３の導電性基材としては、例えば、ニッケル、ニッケル合金、ニッケル鉄、バナジウム、モリブデン、銅、銀、マンガン、白金族元素、黒鉛、若しくはクロム、又はそれらの組み合わせを用いることができる。陽極４３においてはニッケルからなる導電性基材を好ましく用いることができる。触媒層は元素としてニッケルを含むことが好ましい。触媒層は、酸化ニッケル、金属ニッケル、若しくは水酸化ニッケル、又はそれらの組み合わせを含むことが好ましく、ニッケルと他の１種以上の金属との合金を含んでもよい。触媒層は金属ニッケルからなることが特に好ましい。なお、触媒層は、クロム、モリブデン、コバルト、タンタル、ジルコニウム、アルミニウム、亜鉛、白金族元素、若しくは希土類元素、又はそれらの組み合わせをさらに含んでもよい。触媒層の表面に、ロジウム、パラジウム、イリジウム、若しくはルテニウム、又はそれらの組み合わせが追加的な触媒としてさらに担持されていてもよい。陽極４３の導電性基材は剛性の基材であってもよく、可撓性の基材であってもよい。陽極４３を構成する剛性の導電性基材としては、例えばエキスパンドメタル、パンチドメタル等を挙げることができる。また陽極４３を構成する可撓性の導電性基材としては、例えば金属ワイヤーで織った（又は編んだ）金網等を挙げることができる。 As the anode 43, any anode that can be used for the anode reaction of the electrolytic cell 1000 (for example, oxygen generation reaction when the electrolytic cell 1000 is an electrolytic cell for alkaline water electrolysis) can be used without any particular restrictions. The anode 43 usually comprises a conductive base material and a catalytic layer that covers the surface of the base material. It is preferable that the catalytic layer is porous. As the conductive base material of the anode 43 suitable for the oxygen generation reaction, for example, nickel, nickel alloy, nickel iron, vanadium, molybdenum, copper, silver, manganese, platinum group elements, graphite, or chromium, or a combination thereof can be used. A conductive base material made of nickel can be preferably used for the anode 43. It is preferable that the catalytic layer contains nickel as an element. The catalytic layer preferably contains nickel oxide, metallic nickel, or nickel hydroxide, or a combination thereof, and may contain an alloy of nickel and one or more other metals. It is particularly preferable that the catalytic layer is made of metallic nickel. The catalyst layer may further include chromium, molybdenum, cobalt, tantalum, zirconium, aluminum, zinc, a platinum group element, a rare earth element, or a combination thereof. Rhodium, palladium, iridium, ruthenium, or a combination thereof may be further supported on the surface of the catalyst layer as an additional catalyst. The conductive substrate of the anode 43 may be a rigid substrate or a flexible substrate. Examples of the rigid conductive substrate constituting the anode 43 include expanded metal and punched metal. Examples of the flexible conductive substrate constituting the anode 43 include a wire mesh woven (or knitted) with metal wires.
　陰極４４としては、電解槽１０００の陰極反応（例えば電解槽１０００がアルカリ水電解用の電解槽である場合には、水素発生反応）に使用可能な陰極を特に制限なく用いることができる。陰極４４は通常、導電性基材と、該基材の表面を被覆する触媒層とを備える。水素発生反応に適した陰極４４の導電性基材としては、例えば、ニッケル、ニッケル合金、ステンレススチール、軟鋼、ニッケル合金、又は、ステンレススチール若しくは軟鋼の表面にニッケルメッキを施したものを好ましく採用できる。陰極４４の触媒層としては、貴金属酸化物、ニッケル、コバルト、モリブデン、若しくはマンガン、若しくはそれらの酸化物、又は貴金属酸化物からなる触媒層を好ましく採用できる。陰極４４を構成する導電性基材は例えば剛性の基材であってもよく、可撓性の基材であってもよい。陰極４４を構成する剛性の導電性基材としては、例えばエキスパンドメタル、パンチドメタル等を挙げることができる。また陰極４４を構成する可撓性の導電性基材としては、例えば金属ワイヤーで織った（又は編んだ）金網等を挙げることができる。 The cathode 44 can be any cathode that can be used for the cathode reaction of the electrolytic cell 1000 (for example, hydrogen generation reaction when the electrolytic cell 1000 is an electrolytic cell for alkaline water electrolysis) without any particular restrictions. The cathode 44 usually comprises a conductive base material and a catalyst layer that covers the surface of the base material. As the conductive base material of the cathode 44 suitable for the hydrogen generation reaction, for example, nickel, nickel alloy, stainless steel, mild steel, nickel alloy, or stainless steel or mild steel with nickel plating on the surface can be preferably used. As the catalyst layer of the cathode 44, a catalyst layer made of a precious metal oxide, nickel, cobalt, molybdenum, or manganese, or an oxide thereof, or a precious metal oxide can be preferably used. The conductive base material constituting the cathode 44 may be, for example, a rigid base material or a flexible base material. Examples of the rigid conductive base material constituting the cathode 44 include expanded metal, punched metal, etc. Also, examples of the flexible conductive base material constituting the cathode 44 include, for example, a metal mesh woven (or knitted) with metal wires.
　導電リブ４５及び４６としては、公知の導電性リブを用いることができる。電解槽１０００において、導電リブ４５は電解エレメント２００及び陽極エンドセル２１０ｅの隔壁４１から突出して設けられており、導電リブ４６は電解エレメント２００及び陰極エンドセル２２０ｅの隔壁４１から突出して設けられている。導電リブ４５が陽極４３を電解エレメント２００及び陽極エンドセル２１０ｅに対して固定および保持できる限りにおいて、導電リブ４５の接続方法、形状、数、及び配置は特に制限されない。また導電リブ４６が陰極４４を電解エレメント２００及び陰極エンドセル２２０ｅに対して固定および保持できる限りにおいて、導電リブ４６の接続方法、形状、数、及び配置も特に制限されない。導電リブ４５及び４６の材質としては、電解槽１０００が運転される際の環境に耐性を有する（例えばアルカリ耐性を有する）剛性の導電性材料を特に制限なく用いることができ、例えばニッケル、鉄等の単体金属；普通鋼（すなわち低炭素鋼および中炭素鋼。）、高炭素鋼等の炭素鋼、ステンレス鋼（例えばＳＵＳ３０４、ＳＵＳ３１０、ＳＵＳ３１０Ｓ、ＳＵＳ３１６、ＳＵＳ３１６Ｌ等。）等の鋼、等の金属材料を好ましく採用できる。
これら金属材料には、耐食性や導電性を向上させるために、ニッケルめっきを施しても良い。 Known conductive ribs can be used as the conductive ribs 45 and 46. In the electrolytic cell 1000, the conductive rib 45 is provided to protrude from the partition wall 41 of the electrolytic element 200 and the anode end cell 210e, and the conductive rib 46 is provided to protrude from the partition wall 41 of the electrolytic element 200 and the cathode end cell 220e. As long as the conductive rib 45 can fix and hold the anode 43 to the electrolytic element 200 and the anode end cell 210e, the connection method, shape, number, and arrangement of the conductive rib 45 are not particularly limited. In addition, as long as the conductive rib 46 can fix and hold the cathode 44 to the electrolytic element 200 and the cathode end cell 220e, the connection method, shape, number, and arrangement of the conductive rib 46 are not particularly limited. The material for the conductive ribs 45 and 46 can be any rigid conductive material that is resistant to the environment in which the electrolytic cell 1000 is operated (e.g., alkali resistance) and is not particularly limited. For example, metal materials such as nickel, iron, and the like; carbon steels such as ordinary steel (i.e., low carbon steel and medium carbon steel), high carbon steel, and stainless steels (e.g., SUS304, SUS310, SUS310S, SUS316, SUS316L, etc.) can be preferably used.
These metal materials may be nickel-plated to improve corrosion resistance and electrical conductivity.
　陽極側絶縁部材５１及び陰極側絶縁部材５２（図６、９、１３参照。以下において単に「絶縁部材５１及び５２」ということがある。）としては、（例えばアルカリ水電解用の）電解槽において陽極エンドセルと陽極側プレスフレームとの間の電気的絶縁および陰極エンドセルと陰極側プレスフレームとの間の電気的絶縁に使用可能な絶縁部材を特に制限なく用いることができる。絶縁部材５１及び５２の材料の例としては、硬質塩化ビニル樹脂、ポリプロピレン樹脂、ポリエチレン樹脂、ナイロン樹脂、ポリアセタール樹脂、非結晶性ポリエステル樹脂、ポリエーテルエーテルケトン樹脂、ポリエーテルイミド樹脂、ポリフェニレンサルファイド樹脂、ポリベンゾイミダゾール樹脂、ポリテトラフルオロエチレン樹脂、テトラフルオロエチレン－パーフルオロアルキルビニルエーテル共重合体樹脂、テトラフルオロエチレン－エチレン共重合体樹脂等を挙げることができる。 As the anode side insulating member 51 and the cathode side insulating member 52 (see Figures 6, 9, and 13; hereinafter, sometimes simply referred to as "insulating members 51 and 52"), any insulating member that can be used for electrical insulation between the anode end cell and the anode side press frame and between the cathode end cell and the cathode side press frame in an electrolytic cell (for example, for alkaline water electrolysis) can be used without any particular restrictions. Examples of materials for the insulating members 51 and 52 include rigid polyvinyl chloride resin, polypropylene resin, polyethylene resin, nylon resin, polyacetal resin, non-crystalline polyester resin, polyether ether ketone resin, polyetherimide resin, polyphenylene sulfide resin, polybenzimidazole resin, polytetrafluoroethylene resin, tetrafluoroethylene-perfluoroalkyl vinyl ether copolymer resin, tetrafluoroethylene-ethylene copolymer resin, etc.
　陽極側プレスフレーム６１及び陰極側プレスフレーム６２（図６～８、１４参照。以下において単に「プレスフレーム６１及び６２」ということがある。）は、不図示のタイロッドによって締結されることにより、陽極側プレスフレーム６１と陰極側プレスフレーム６２との間に配置された、絶縁部材５１及び５２、各電解エレメント２００、各隔膜エレメント１００、陽極エンドセル２１０ｅ、陰極エンドセル２２０ｅを一体化する。プレスフレーム６１及び６２は、上記締結の荷重に耐える剛性を有する金属材料で形成されている。プレスフレーム６１及び６２を構成する金属材料の例としては、ＳＳ４００等の炭素鋼やＳＵＳ３０４、ＳＵＳ３１６等のステンレス鋼等を挙げることができる。 The anode side press frame 61 and the cathode side press frame 62 (see Figures 6 to 8 and 14; hereinafter, sometimes simply referred to as "press frames 61 and 62") are fastened by tie rods (not shown) to integrate the insulating members 51 and 52, the electrolytic elements 200, the diaphragm elements 100, the anode end cell 210e, and the cathode end cell 220e arranged between the anode side press frame 61 and the cathode side press frame 62. The press frames 61 and 62 are formed of a metal material having the rigidity to withstand the fastening load. Examples of the metal material constituting the press frames 61 and 62 include carbon steel such as SS400 and stainless steel such as SUS304 and SUS316.
　電解槽１０００は、隔膜１０の周縁部および隔膜１０とガスケット２０との接触部が電解槽外部に通じていないので、加圧運転に適した構造を有する。その一方で、電解槽１０００においては、柔軟な隔膜１０が隔膜エレメント１００に収容および保持されているので、電解槽１０００の組み立て作業を行うにあたって隔膜１０を別途の仮保持手段を用いて仮保持する必要がない。そして、電解エレメントの一定数（通常は、５～１５エレメント程度）を水平方向に積みあげたところで、これを縦に起こして積層していく方法で、電解槽の組み立てを実施しても、上記縦への起こしの際に、挟持力不足で、一部の電解エレメントにおいて隔膜が下方へズレ落ちる不良も生じない。したがって電解槽１０００は、加圧運転に適した電解槽でありながら、組立作業性が高められている。
　また電解槽１０００においては、使用により劣化した隔膜１０を交換するための分解再組立て作業の作業性も高められている。隔膜エレメント１００において、ネジ３３が枠状の基体３１のネジ穴に螺合されることにより、隔膜１０を挟持したガスケット２０が枠状の基体３１の支持部３１ｂと蓋部材３２とによって締め付けられ、且つ、蓋部材３２、ガスケット２０、及び隔膜１０が枠状の基体３１に着脱可能に固定される。したがって隔膜１０を交換する際には、枠状の基体３１及び蓋部材３２を再利用することが可能であり、ガスケット２０の状態が良ければガスケット２０も再利用できる。そして新たな隔膜１０を用いて隔膜エレメント１００を組み立てるにあたり、加熱等の、隔膜１０の性能または寿命に悪影響を及ぼし得る操作は不要である。 The electrolytic cell 1000 has a structure suitable for pressurized operation because the peripheral portion of the diaphragm 10 and the contact portion between the diaphragm 10 and the gasket 20 do not communicate with the outside of the electrolytic cell. On the other hand, in the electrolytic cell 1000, the flexible diaphragm 10 is contained and held in the diaphragm element 100, so there is no need to temporarily hold the diaphragm 10 using a separate temporary holding means when assembling the electrolytic cell 1000. Furthermore, even if the electrolytic cell is assembled by stacking a certain number of electrolytic elements (usually about 5 to 15 elements) in the horizontal direction and then vertically raising and stacking these elements, there is no defect in that the diaphragms of some of the electrolytic elements slip downward due to insufficient clamping force during the vertical raising. Thus, the electrolytic cell 1000 is an electrolytic cell suitable for pressurized operation, while having improved assembly workability.
The electrolytic cell 1000 also improves the workability of disassembly and reassembly for replacing the diaphragm 10 that has deteriorated with use. In the diaphragm element 100, the screw 33 is screwed into the screw hole of the frame-shaped base 31, whereby the gasket 20 holding the diaphragm 10 is fastened by the support part 31b of the frame-shaped base 31 and the cover member 32, and the cover member 32, the gasket 20, and the diaphragm 10 are detachably fixed to the frame-shaped base 31. Therefore, when replacing the diaphragm 10, the frame-shaped base 31 and the cover member 32 can be reused, and if the gasket 20 is in good condition, the gasket 20 can also be reused. When assembling the diaphragm element 100 using a new diaphragm 10, no operation that may adversely affect the performance or lifespan of the diaphragm 10, such as heating, is required.
　陽極エンドセル２１０ｅには陽極端子が、陰極エンドセル２２０ｅには陰極端子が、それぞれ接続されている。また陽極側プレスフレーム６１、陰極側プレスフレーム６２、陰極液供給管８１、陽極液供給管８２、陽極液・ガス回収管８３、及び陰極液・ガス回収管８４は、いずれも電気的に接地されていることが好ましい（図６、７）。 An anode terminal is connected to the anode end cell 210e, and a cathode terminal is connected to the cathode end cell 220e. It is also preferable that the anode side press frame 61, the cathode side press frame 62, the cathode liquid supply pipe 81, the anode liquid supply pipe 82, the anode liquid and gas recovery pipe 83, and the cathode liquid and gas recovery pipe 84 are all electrically grounded (Figures 6 and 7).
　陽極室および陰極室の少なくとも一方を大気圧よりも高圧に維持しながら電解を行う場合、陰極室内部の圧力は大気圧に対して２０ｋＰａ以上高圧であることが好ましく、４００ｋＰａ以上高圧であることがより好ましく、８００ｋＰａ以上高圧であることがさらに好ましい。陰極室内部の圧力の上限は電解槽を構成する部材の強度にもよるが、例えば大気圧＋３０００ｋＰａ未満とすることができる。陰極室内部の圧力が上記下限値以上であることにより、陰極室から水素ガスを回収した後の昇圧工程における圧縮率を低減、または昇圧工程を省略することができるので、設備コストを削減し、設備全体として省スペース化および省エネルギー化を図ることが可能になる。また陰極室内部の圧力が上記下限値以上であることにより、電解電圧を低減する効果が得られる。これは陰極室で発生する気泡のサイズが小さくなることにより、陽極－陰極間の気泡抵抗が減少することに由来すると考えられる。 When electrolysis is performed while maintaining at least one of the anode chamber and the cathode chamber at a pressure higher than atmospheric pressure, the pressure inside the cathode chamber is preferably 20 kPa or more higher than atmospheric pressure, more preferably 400 kPa or more higher, and even more preferably 800 kPa or more higher. The upper limit of the pressure inside the cathode chamber depends on the strength of the members constituting the electrolytic cell, but can be, for example, less than atmospheric pressure + 3000 kPa. By having the pressure inside the cathode chamber be equal to or higher than the above lower limit, the compression ratio in the pressure increase step after recovering hydrogen gas from the cathode chamber can be reduced or the pressure increase step can be omitted, reducing equipment costs and enabling the equipment to be space-saving and energy-saving as a whole. In addition, by having the pressure inside the cathode chamber be equal to or higher than the above lower limit, the electrolysis voltage can be reduced. This is thought to be due to the fact that the size of the bubbles generated in the cathode chamber becomes smaller, thereby reducing the bubble resistance between the anode and cathode.
　また陽極室および陰極室の少なくとも一方を大気圧よりも高圧に維持しながら電解を行う場合、陽極室内部の圧力は大気圧に対して２０ｋＰａ以上高圧であることが好ましく、４００ｋＰａ以上高圧であることがより好ましく、８００ｋＰａ以上高圧であることがさらに好ましい。陽極室内部の圧力の上限は電解槽を構成する部材の強度にもよるが、例えば大気圧＋３０００ｋＰａ未満とすることができる。陽極室内部の圧力が上記下限値以上であることにより、陽極室から酸素ガスを回収した後の昇圧工程における圧縮率を低減、または昇圧工程を省略することができるので、設備コストをさらに削減し、設備全体としてさらなる省スペース化および省エネルギー化を図ることが可能になる。また陽極室内部の圧力が上記下限値以上であることにより、電解電圧を低減する効果が得られる。これは陽極室で発生する気泡のサイズが小さくなることにより、陽極－陰極間の気泡抵抗がさらに減少することに由来すると考えられる。 When electrolysis is performed while maintaining at least one of the anode chamber and the cathode chamber at a pressure higher than atmospheric pressure, the pressure inside the anode chamber is preferably 20 kPa or more higher than atmospheric pressure, more preferably 400 kPa or more higher, and even more preferably 800 kPa or more higher. The upper limit of the pressure inside the anode chamber depends on the strength of the members constituting the electrolytic cell, but can be, for example, less than atmospheric pressure + 3000 kPa. By having the pressure inside the anode chamber be equal to or higher than the lower limit, the compression ratio in the pressure increase step after oxygen gas is recovered from the anode chamber can be reduced or the pressure increase step can be omitted, which further reduces equipment costs and enables further space and energy savings for the entire facility. In addition, by having the pressure inside the anode chamber be equal to or higher than the lower limit, the electrolysis voltage can be reduced. This is thought to be due to the fact that the size of the bubbles generated in the anode chamber becomes smaller, which further reduces the bubble resistance between the anode and cathode.
　陰極室内部の圧力と陽極室内部の圧力との差は、例えば５．０ｋＰａ未満であることが好ましく、１．０ｋＰａ未満であることがより好ましい。陰極室内部の圧力と陽極室内部の圧力との差が上記上限値未満であることにより、陽極室－陰極室間の差圧に起因してガスが隔膜を透過して陽極室から陰極室へ又は陰極室から陽極室へ移動することを抑制すること、及び、陽極室－陰極室間の差圧に起因して隔膜が損傷する事態を抑制することが容易になる。 The difference between the pressure inside the cathode chamber and the pressure inside the anode chamber is preferably less than 5.0 kPa, for example, and more preferably less than 1.0 kPa. By having the difference between the pressure inside the cathode chamber and the pressure inside the anode chamber be less than the above upper limit, it becomes easier to prevent gas from passing through the diaphragm and moving from the anode chamber to the cathode chamber or from the cathode chamber to the anode chamber due to the pressure difference between the anode chamber and the cathode chamber, and to prevent the diaphragm from being damaged due to the pressure difference between the anode chamber and the cathode chamber.
　本発明に関する上記説明では、各極液供給管／回収管８１～８４が、陰極側プレスフレーム６２及び陰極側絶縁部材５２に設けられた第１～第４の貫通孔６２ａ／５２ａ～６２ｄ／５２ｄを通じて、各極液供給流路／回収流路７１～７４にそれぞれ接続されている形態の電解槽１０００を例に挙げたが、本発明は当該形態に限定されない。例えば、各極液供給管／回収管のうち一つ以上が、陽極側プレスフレーム及び陽極側絶縁部材に設けられた貫通孔を通じて、対応する極液供給流路／回収流路に接続されている形態の電解槽とすることも可能である。 In the above description of the present invention, an electrolytic cell 1000 is given as an example in which the electrode liquid supply pipes/recovery pipes 81-84 are connected to the electrode liquid supply flow paths/recovery flow paths 71-74 through the first to fourth through holes 62a/52a-62d/52d provided in the cathode side press frame 62 and the cathode side insulating member 52, respectively, but the present invention is not limited to this configuration. For example, it is also possible to have an electrolytic cell in which one or more of the electrode liquid supply pipes/recovery pipes are connected to the corresponding electrode liquid supply flow paths/recovery flow paths through through holes provided in the anode side press frame and the anode side insulating member.
　＜３．ガス製造方法＞
　本発明の電解槽は、例えばアルカリ水の電解によるガスの製造に好ましく用いることができる。一の実施形態に係るガス製造方法は、アルカリ水を電解して少なくとも水素ガスを製造する方法であって、（ａ）本発明の電解槽を用いてアルカリ水を電解する工程を含む。工程（ａ）における電解槽としては、例えば、上記説明した電解槽１０００を用いることができる。アルカリ水としては、アルカリ水電解法による水素の製造に用いられる公知の塩基性水溶液（例えばＫＯＨ水溶液、ＮａＯＨ水溶液等。）を特に制限なく用いることができる。 3. Gas production method
The electrolytic cell of the present invention can be preferably used, for example, for producing gas by electrolysis of alkaline water. A gas production method according to one embodiment is a method for producing at least hydrogen gas by electrolyzing alkaline water, and includes the step (a) of electrolyzing alkaline water using the electrolytic cell of the present invention. As the electrolytic cell in the step (a), for example, the electrolytic cell 1000 described above can be used. As the alkaline water, any known basic aqueous solution (e.g., a KOH aqueous solution, a NaOH aqueous solution, etc.) used in hydrogen production by alkaline water electrolysis can be used without any particular limitation.
　工程（ａ）は、本発明の電解槽の各陽極室および各陰極室に電解液（アルカリ水）を供給し、陽極－陰極間に所定の電解電流が流れるように電圧を印加する（電解槽に直流電流を通電する）ことにより、行うことができる。電解により発生したガスを各極室から電解液とともに回収し、気液分離を行うことにより、陰極室から水素ガスを、及び陽極室から酸素ガスを、それぞれ回収することができる。気液分離によりガスから分離された電解液は、必要に応じて水を補充しつつ、各極室へ再度供給することができる。 Step (a) can be carried out by supplying an electrolyte (alkaline water) to each anode chamber and each cathode chamber of the electrolytic cell of the present invention, and applying a voltage so that a predetermined electrolytic current flows between the anode and cathode (passing a direct current through the electrolytic cell). The gas generated by electrolysis is recovered from each electrode chamber together with the electrolyte, and by performing gas-liquid separation, hydrogen gas can be recovered from the cathode chamber and oxygen gas can be recovered from the anode chamber. The electrolyte separated from the gas by gas-liquid separation can be supplied again to each electrode chamber, with water being replenished as necessary.
　工程（ａ）において、陰極室内部の圧力は大気圧に対して２０ｋＰａ以上高圧に維持されることが好ましい。陰極室内部の圧力は大気圧に対して４００ｋＰａ以上高圧であることが好ましく、８００ｋＰａ以上高圧であることがより好ましい。陰極室内部の圧力の上限は電解槽を構成する部材の強度にもよるが、例えば大気圧＋１０００ｋＰａ未満とすることができる。陰極室内部の圧力が上記下限値以上であることにより、陰極室から水素ガスを回収した後の昇圧工程における圧縮率を低減、または昇圧工程を省略することができるので、設備コストを削減し、設備全体として省スペース化および省エネルギー化を図ることが可能になる。また陰極室内部の圧力が上記下限値以上であることにより、陰極室で発生する気泡のサイズが小さくなるので、陽極－陰極間の抵抗が減少し、したがって電解電圧を低減することが可能になる。 In step (a), the pressure inside the cathode chamber is preferably maintained at 20 kPa or more higher than atmospheric pressure. The pressure inside the cathode chamber is preferably 400 kPa or more higher than atmospheric pressure, and more preferably 800 kPa or more higher. The upper limit of the pressure inside the cathode chamber depends on the strength of the members constituting the electrolytic cell, but can be, for example, less than atmospheric pressure + 1000 kPa. By having the pressure inside the cathode chamber be equal to or higher than the lower limit, the compression ratio in the pressure increase step after recovering hydrogen gas from the cathode chamber can be reduced or the pressure increase step can be omitted, thereby reducing equipment costs and enabling the equipment to be space- and energy-efficient as a whole. In addition, by having the pressure inside the cathode chamber be equal to or higher than the lower limit, the size of the bubbles generated in the cathode chamber becomes smaller, reducing the resistance between the anode and cathode, and therefore making it possible to reduce the electrolysis voltage.
　工程（ａ）において、陽極室内部の圧力も、大気圧に対して２０ｋＰａ以上高圧に維持されることが好ましい。陽極室内部の圧力は大気圧に対して４００ｋＰａ以上高圧であることが好ましく、８００ｋＰａ以上高圧であることがより好ましい。陽極室内部の圧力の上限は電解槽を構成する部材の強度にもよるが、例えば大気圧＋１０００ｋＰａ未満とすることができる。陽極室内部の圧力が上記下限値以上であることにより、陽極室から酸素ガスを回収した後の昇圧工程における圧縮率を低減、または昇圧工程を省略することができるので、設備コストをさらに削減し、設備全体としてさらなる省スペース化および省エネルギー化を図ることが可能になる。また陽極室内部の圧力が上記下限値以上であることにより、陽極室で発生する気泡のサイズが小さくなるので、陽極－陰極間の抵抗がさらに減少し、したがって電解電圧をさらに低減することが可能になる。 In step (a), the pressure inside the anode chamber is preferably maintained at 20 kPa or more higher than atmospheric pressure. The pressure inside the anode chamber is preferably 400 kPa or more higher than atmospheric pressure, and more preferably 800 kPa or more higher. The upper limit of the pressure inside the anode chamber depends on the strength of the members constituting the electrolytic cell, but can be, for example, less than atmospheric pressure + 1000 kPa. By having the pressure inside the anode chamber be equal to or higher than the lower limit, the compression ratio in the pressure increase step after recovering oxygen gas from the anode chamber can be reduced or the pressure increase step can be omitted, which further reduces equipment costs and enables further space and energy savings for the entire facility. In addition, by having the pressure inside the anode chamber be equal to or higher than the lower limit, the size of the bubbles generated in the anode chamber becomes smaller, which further reduces the resistance between the anode and cathode, and therefore makes it possible to further reduce the electrolysis voltage.
　工程（ａ）において、陰極室内部の圧力と陽極室内部の圧力との差は、例えば５．０ｋＰａ未満であることが好ましく、１．０ｋＰａ未満であることがより好ましい。陰極室内部の圧力と陽極室内部の圧力との差が上記上限値未満であることにより、陽極室－陰極室間の差圧に起因してガスが隔膜を透過して陽極室から陰極室へ又は陰極室から陽極室へ移動することを抑制すること、及び、陽極室－陰極室間の差圧に起因して隔膜が損傷する事態を抑制することが容易になる。 In step (a), the difference between the pressure inside the cathode chamber and the pressure inside the anode chamber is, for example, preferably less than 5.0 kPa, and more preferably less than 1.0 kPa. By having the difference between the pressure inside the cathode chamber and the pressure inside the anode chamber be less than the above upper limit, it becomes easier to prevent gas from passing through the diaphragm due to the pressure difference between the anode chamber and the cathode chamber and moving from the anode chamber to the cathode chamber or from the cathode chamber to the anode chamber, and to prevent the diaphragm from being damaged due to the pressure difference between the anode chamber and the cathode chamber.
　本発明の電解槽は、組立作業性が高められているので、使用に伴って劣化した隔膜１０を新たな隔膜１０に交換する作業が必要になった際にも、電解槽を運転できない時間を低減する、又は、交換作業に要する費用を低減することが可能である。 The electrolytic cell of the present invention has improved assembly workability, so that even when it becomes necessary to replace a diaphragm 10 that has deteriorated with use with a new diaphragm 10, it is possible to reduce the time during which the electrolytic cell cannot be operated or to reduce the cost of the replacement work.
　また本発明の電解槽は、極室内部の圧力に対する耐性が向上しているとともに、隔膜が受ける熱および機械的圧力による隔膜の性能低下が抑制されている。したがって本発明の電解槽を用いてアルカリ水の電解を行うことにより、極室内部の圧力を高めた条件でも、より安全に且つより効率的に電解を行うことが可能である。 The electrolytic cell of the present invention also has improved resistance to pressure inside the electrode chamber, and the deterioration of the diaphragm's performance due to the heat and mechanical pressure to which it is subjected is suppressed. Therefore, by electrolyzing alkaline water using the electrolytic cell of the present invention, it is possible to perform electrolysis more safely and efficiently, even under conditions of increased pressure inside the electrode chamber.
１０　（イオン透過性の）隔膜
２０　ガスケット
３０　（枠状の）保護部材
３１　（枠状の）基体
３１ａ　受容部
３１ｂ　支持部
３１ｈ　ネジ穴
３１ｅａ　第１の電解液供給用流通孔（陽極液供給用流通孔）
３１ｅｂ　第２の電解液供給用流通孔（陰極液供給用流通孔）
３１ｅｃ　第２の電解液－ガス回収用流通孔（陰極液－ガス回収用流通孔）
３１ｅｄ　第１の電解液－ガス回収用流通孔（陽極液－ガス回収用流通孔）
３１ｇａ　第１の流路溝（分岐流路）
３１ｇｃ　第２の流路溝（分岐流路）
３１ｓ　シール材
３１ｆａ　第１の面
３１ｆｂ　第２の面
３２ｈ　第１の貫通孔
３２ｈａ　（第１の貫通孔の）細部
３２ｈｂ　（第１の貫通孔の）広部
２０ｈ　第２の貫通孔
１０ｈ　第３の貫通孔
３２　（枠状の）蓋部材
３３　ネジ
３３ａ　軸部
３３ｂ　頭部
４１　（導電性の）隔壁
４５、４６　導電リブ
４３　陽極
４４　陰極
５１　陽極側絶縁部材
５２　陰極側絶縁部材
６１　陽極側プレスフレーム
６２　陰極側プレスフレーム
７１　第２の電解液供給流路（陰極液供給流路）
７２　第１の電解液供給流路（陽極液供給流路）
７３　第１の電解液－ガス回収流路（陽極液－ガス回収流路）
７４　第２の電解液－ガス回収流路（陰極液－ガス回収流路）
８１　陰極液供給管
８２　陽極液供給管
８３　陽極液・ガス回収管
８４　陰極液・ガス回収管
１００　隔膜エレメント
２００　電解エレメント
２１０ｅ　陽極エンドセル
２２０ｅ　陰極エンドセル
１０００　電解槽
Ａ１、Ａ２、Ａ３　陽極室
Ｃ１、Ｃ２、Ｃ３　陰極室 10 (ion-permeable) diaphragm 20 Gasket 30 (frame-shaped) protective member 31 (frame-shaped) base 31a Receptacle 31b Support 31h Screw hole 31ea First electrolyte supply flow hole (anode electrolyte supply flow hole)
31eb Second electrolyte supply passage hole (cathode electrolyte supply passage hole)
31ec Second electrolyte-gas recovery passage hole (cathode electrolyte-gas recovery passage hole)
31ed First electrolyte-gas recovery passage hole (anode electrolyte-gas recovery passage hole)
31ga First flow channel (branch flow channel)
31gc Second flow channel (branch flow channel)
[0033] 31s sealing material 31fa first surface 31fb second surface 32h first through hole 32ha narrow portion 32hb (of first through hole) wide portion 20h second through hole 10h third through hole 32 (frame-shaped) cover member 33 screw 33a shaft portion 33b head portion 41 (conductive) partition walls 45, 46 conductive rib 43 anode 44 cathode 51 anode side insulating member 52 cathode side insulating member 61 anode side press frame 62 cathode side press frame 71 second electrolyte solution supply flow path (cathode solution supply flow path)
72 First electrolyte supply flow path (anolyte supply flow path)
73 First electrolyte-gas recovery passage (anode liquid-gas recovery passage)
74 Second electrolyte-gas recovery flow path (cathode electrolyte-gas recovery flow path)
81 Catholyte supply pipe 82 Anolyte supply pipe 83 Anolyte/gas recovery pipe 84 Catholyte/gas recovery pipe 100 Diaphragm element 200 Electrolysis element 210e Anode end cell 220e Cathode end cell 1000 Electrolysis cells A1, A2, A3 Anode chambers C1, C2, C3 Cathode chambers

Claims (5)

  1. 　第１の面および第２の面を有する、イオン透過性の隔膜と、
    　前記隔膜の周縁部を挟持する、ガスケットと、
    　前記隔膜を挟持した前記ガスケットを受け入れ保持する、枠状の保護部材と、
    を備え、
      前記保護部材は、電気絶縁性の枠状の基体と、枠状の蓋部材と、複数のネジとを備え、

      前記枠状の基体は、
    　　該基体の内周側に設けられ、前記ガスケット及び前記蓋部材を受け入れる受容部と、
      前記受容部より前記基体の内周側に向けて突出して延在し、前記受容部に受け容れられた前記ガスケットを前記隔膜の主面に交差する方向に支持する支持部と
    を備え、
    　前記蓋部材は、前記基体の受容部に受け容れられることが可能な形状および寸法を有し、
    　前記基体の受容部に、前記隔膜を挟持した前記ガスケット、及び、前記蓋部材が受け容れられることにより、前記隔膜を挟持した前記ガスケットが前記基体の支持部と前記蓋部材との間に挟持され、
    　前記枠状の基体の支持部は、前記ガスケットに向けて開口するように設けられた、前記ネジと螺合可能な複数のネジ穴を備え、
    　前記蓋部材は、前記枠状の基体の複数のネジ穴に対応する位置に設けられた、前記ネジを挿通可能な複数の第１の貫通孔を備え、
    　前記ガスケットは、前記枠状の基体の複数のネジ穴に対応する位置に設けられた、前記ネジを挿通可能な複数の第２の貫通孔を備え、
    　前記隔膜は、前記枠状の基体の複数のネジ穴に対応する位置に設けられた、前記ネジを挿通可能な複数の第３の貫通孔を備え、
    　前記枠状の基体の複数のネジ穴と、前記蓋部材の複数の第１の貫通孔と、前記ガスケットの複数の第２の貫通孔と、前記隔膜の複数の第３の貫通孔とが、相互に連通し、
    　前記複数のネジのそれぞれが、前記蓋部材の第１の貫通孔、前記ガスケットの第２の貫通孔、及び前記隔膜の第３の貫通孔に挿通され、前記枠状の基体のネジ穴に螺合されることにより、前記隔膜を挟持したガスケットが前記蓋部材と前記枠状の基体の支持部とによって締め付けられ、且つ、前記蓋部材、前記ガスケット、及び前記隔膜が前記枠状の基体に着脱可能に固定される、隔膜エレメント。     an ion-permeable membrane having a first surface and a second surface;
    A gasket that holds a peripheral portion of the diaphragm;
    a frame-shaped protective member that receives and holds the gasket that sandwiches the diaphragm;
    Equipped with
    the protective member includes an electrically insulating frame-shaped base, a frame-shaped cover member, and a plurality of screws;

    The frame-shaped base body is
    a receiving portion provided on an inner circumferential side of the base body and receiving the gasket and the cover member;
    a support portion that projects and extends from the receiving portion toward an inner circumferential side of the base and supports the gasket received in the receiving portion in a direction intersecting with a main surface of the diaphragm,
    the cover member has a shape and a size that allows it to be received in the receiving portion of the base;
    the gasket holding the diaphragm therebetween and the cover member are received in the receiving portion of the base, whereby the gasket holding the diaphragm therebetween is held between the support portion of the base and the cover member,
    the support portion of the frame-shaped base includes a plurality of screw holes that are open toward the gasket and can be screwed into the screws,
    the cover member includes a plurality of first through holes through which the screws can be inserted, the first through holes being provided at positions corresponding to the plurality of screw holes in the frame-shaped base,
    the gasket includes a plurality of second through holes, through which the screws can be inserted, the second through holes being provided at positions corresponding to the plurality of screw holes of the frame-shaped base,
    the diaphragm includes a plurality of third through holes, through which the screws can be inserted, the third through holes being provided at positions corresponding to the plurality of screw holes of the frame-shaped base,
    a plurality of screw holes in the frame-shaped base, a plurality of first through holes in the cover member, a plurality of second through holes in the gasket, and a plurality of third through holes in the diaphragm are mutually communicated,
    a diaphragm element in which each of the plurality of screws is inserted through a first through hole of the cover member, a second through hole of the gasket, and a third through hole of the diaphragm and screwed into a screw hole of the frame-shaped base, such that the gasket holding the diaphragm is fastened between the cover member and a support portion of the frame-shaped base, and the cover member, the gasket, and the diaphragm are removably fixed to the frame-shaped base.
  2. 　積層された複数の電解エレメントであって、前記複数の電解エレメントのそれぞれは、陽極と、導電性の隔壁と、陰極とを上記順に備え、前記陽極および前記陰極はそれぞれ前記隔壁に電気的に接続されている、複数の電解エレメントと、
    　隣接する前記電解エレメントの各組の間に配置された、請求項１に記載の隔膜エレメントと
    を備え、
    　前記複数の電解エレメントは、各電解エレメントの陽極が前記導電性の隔壁の同じ側に現れるように積層され、
    　前記隔膜エレメントの前記隔膜と、該隔膜エレメントに隣接する一方の電解エレメントとの間に、前記陽極を収容する陽極室が画定され、
    　前記隔膜エレメントの前記隔膜と、該隔膜エレメントに隣接する他方の電解エレメントとの間に、前記陰極を収容する陰極室が画定されている、電解槽。     a plurality of stacked electrolytic elements, each of the plurality of electrolytic elements including an anode, a conductive partition wall, and a cathode, in the above-mentioned order, the anode and the cathode being each electrically connected to the partition wall;
    and a membrane element according to claim 1 disposed between each pair of adjacent electrolytic elements.
    the plurality of electrolytic elements are stacked such that the anodes of the electrolytic elements appear on the same side of the conductive partition wall;
    an anode chamber accommodating the anode is defined between the diaphragm of the diaphragm element and one of the electrolytic elements adjacent to the diaphragm element;
    an electrolytic cell, wherein a cathode chamber accommodating the cathode is defined between the diaphragm of the diaphragm element and another electrolytic element adjacent to the diaphragm element.
  3. 　アルカリ水の電解により少なくとも水素ガスを製造する方法であって、
    　（ａ）請求項２に記載の電解槽を用いてアルカリ水を電解する工程
    を含み、
    　前記工程（ａ）は、
    　　前記電解槽の各陽極室および各陰極室に電解液としてアルカリ水を供給することと、
      前記電解槽に直流電流を通電することと、
    　　前記陰極室から水素ガスを回収することと、
    を含む、ガス製造方法。     A method for producing at least hydrogen gas by electrolysis of alkaline water, comprising the steps of:
    (a) electrolyzing alkaline water using the electrolytic cell according to claim 2,
    The step (a)
    supplying alkaline water as an electrolytic solution to each anode chamber and each cathode chamber of the electrolytic cell;
    Passing a direct current through the electrolytic cell;
    recovering hydrogen gas from the cathode chamber;
    A method for producing gas comprising:
  4. 　前記工程（ａ）が、前記陽極室から酸素ガスを回収することをさらに含む、
    請求項３に記載のガス製造方法。     The step (a) further comprises recovering oxygen gas from the anode chamber.
    The gas production method according to claim 3 .
  5. 　前記工程（ａ）において、前記陽極室および／または前記陰極室内部の圧力が、大気圧に対して＋２０ｋＰａ以上に保たれる、
    請求項３又は４に記載のガス製造方法。     In the step (a), the pressure inside the anode chamber and/or the cathode chamber is maintained at +20 kPa or more relative to atmospheric pressure.
    The gas production method according to claim 3 or 4.
PCT/JP2023/044247 2022-12-14 2023-12-11 Diaphragm element, electrolytic cell and gas production method WO2024128196A1 (en)

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JP2022-199540 2022-12-14
JP2022199540 2022-12-14

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