Abstract: The present invention provides a simple method for producing an electrode having improved oxygen evolution reaction (OER) activity without a need for catalyst coating and an electrode produced by this production method. The method is a method for producing an electrode including a step of subjecting an electrically conductive substrate comprising a nickel alloy comprising 30 to 70% by mass of Ni and 30 to 70% by mass of Fe, provided that Ni+Fi=100% by mass, to a thermal treatment, and a step of etching the thermally treated electrically conductive substrate with an etchant comprising at least any acid of an organic acid and a weak inorganic acid. The electrode is an electrode that is produced by this production method and that is useful as an oxygen evolution anode or the like.

Abstract: Disclosed is a purification method of electrolytic gas generated from an electrolysis cell having a cathode and an anode. In a step of performing electrolysis of an electrolyte solution supplied into the electrolysis cell and repeating the electrolysis while circulating the electrolyzed electrolyte solution via an circulation tank disposed outside the electrolysis cell, a bag-shaped membrane pack, which is made from a specific porous membrane material, is of a shape having an opening at a top end thereof and closed at an entire side wall and entire bottom wall thereof and has a large permeation area at the entire side wall and entire bottom wall, is disposed in an interior of the circulation tank, thereby enabling to perform the electrolysis while purifying the electrolyte solution in which a portion of the electrolytic gas generated by the electrolysis is dissolved and bubbles of another portion of the electrolytic gas coexist.

Abstract: To provide a method and an apparatus for producing a sodium hypochlorite solution on-site at a high efficiency and at the initial cost and suppressing operating cost without any problems about impurities derived from raw material water and raw salt. A method of producing a sodium hypochlorite solution on-site in the vicinity of a physical plant where a sodium hypochlorite solution is used.

Abstract: To provide a production method and a production apparatus of a sodium hypochlorite solution that can produce a sodium hypochlorite solution with a high available chlorine concentration at a low cost using an on-site facility.

Abstract: To provide a method and an apparatus for producing a sodium hypochlorite solution on-site at a high efficiency and at the initial cost and suppressing operating cost without any problems about impurities derived from raw material water and raw salt. A method of producing a sodium hypochlorite solution on-site in the vicinity of a physical plant where a sodium hypochlorite solution is used.

Abstract: There are provided an electrolyzer gasket, which can accommodate and hold a separator inside an electrolyzer by a simple handling, can more surely prevent leakage of an electrolyte and an electrolytically generated gas from the inside of the electrolyzer, can keep the separator in such a state that the separator is held at a position that is in contact with one of electrodes and is located along the electrode and therefore can suppress damage of the separator and makes it possible to use the separator stably for a long period of time, and an electrolyzer.

Abstract: The present invention provides an alkaline water electrolysis anode such that even when electric power having a large output fluctuation, such as renewable energy, is used as a power source, the electrolysis performance is unlikely to be deteriorated and excellent catalytic activity is retained stably over a long period of time. The alkaline water electrolysis anode is an alkaline water electrolysis anode 10 provided with an electrically conductive substrate 2 at least a surface of which contains nickel or a nickel base alloy and a catalyst layer 6 disposed on the surface of the electrically conductive substrate 2, the catalyst layer 6 containing a nickel-containing metal oxide having a spinel structure, wherein the nickel-containing metal oxide contains nickel (Ni) and manganese (Mn), and has an atom ratio of Li/Ni/Mn/O of (0.0 to 0.8)/(0.4 to 0.6)/(1.0 to 1.8)/4.0.

Abstract: An organic hydride production device comprises an electrolyzer and a water removal device. The electrolyzer has a cathode chamber. The water removal device has a container that stores a catholyte fed from the cathode chamber, a drain pipe that discharges dragged water from the container, a detector that detects that the dragged water has been accumulated in the container, and a switcher that is provided in the drain pipe, is capable of switching between a regulation state in which drainage from the drain pipe is regulated and an execution state in which the drainage is executed, and switches from the regulation state to the execution state based on a detection result of the detector.

Abstract: The present invention provides an electrode for electrolysis in which electrolysis performance is hard to deteriorate and excellent catalytic activity is kept stable over a long period of time even when electric power in which there is a large fluctuation in output, such as renewable energy, is used as a power source. The electrode for electrolysis is an electrode 10 for electrolysis provided with an electrically conductive substrate 2 at least the surface of which contains nickel or a nickel-based alloy, an intermediate layer 4 formed on the surface of the electrically conductive substrate 2 and containing a lithium-containing nickel oxide represented by composition formula LixNi2-xO2 (0.02?x?0.5), and a catalyst layer 6 of a nickel cobalt spinel oxide, an iridium oxide, or the like, the catalyst layer 6 formed on the surface of the intermediate layer 4.

Abstract: A wastewater treatment method includes: a soft water treatment 1 of crystallizing calcium carbonate from wastewater to remove the calcium carbonate therefrom; and an electrolysis 2 of electrolyzing some of the wastewater from which the calcium carbonate has been removed to obtain an acidic aqueous solution and an alkaline aqueous solution, wherein at least some of the alkaline aqueous solution is circulated to be used in the soft water treatment 1.

Abstract: [Problem] To provide a stacked structure including electrodes that can effectively prevent misalignment between units. [Solution] A stacked structure 2 including electrodes 232, 332, 412, 233, 333, 422, wherein multiple units 23, 33, 24, 41, 42 including flat units are stacked and fastened by fasteners 25, the respective units 23, 33, 24, 41, 42 comprising frame-shaped fastening portions 237a, 237b, 337a, 337b, 247a, 247b, 417a, 417b, 427a, 427b on outer peripheral portions on both surfaces thereof, being stacked by the surfaces of the respective fastening portions 237a, 237b, 337a, 337b, 247a, 247b, 417a, 417b, 427a, 427b being pressed against each other, and being formed so that the width of fastening portions 247a, 247b, 337a, 337b, 427a, 427b on one unit is different from the width of fastening portions 237a, 237b, 417a, 417b on another unit.

Abstract: The present invention realizes industrially excellent effects such that when electric power having a large output fluctuation, such as renewable energy, is used as a power source, electrolysis performance is unlikely to be deteriorated and excellent catalytic activity is retained stably over a longer period of time, and in addition, the present invention provides a technique that enables forming a catalyst layer of an oxygen generation anode, which gives such excellent effects, with a more versatile materials and by a simple electrolysis method.

Abstract: An organic hydride production apparatus includes: an electrolyte membrane having proton conductivity; a cathode that includes a cathode catalyst layer used to hydrogenate a hydrogenation target substance using protons to produce an organic hydride and also includes a cathode chamber; an anode that includes an anode catalyst layer used to oxidize water to produce protons and also includes an anode chamber; and a gas introduction unit that introduces, into the anolyte at a certain position, a certain gas used to remove at least one of the hydrogenation target substance and the organic hydride that have passed through the electrolyte membrane and been mixed into the anolyte.

Abstract: Provided is an electrolytic apparatus capable of pressurizing hydrogen gas produced by the electrolytic apparatus and removing impurities in the produced hydrogen gas. In the electrolytic apparatus, gas compression means 101 including an ejector 110, a storage tank 103 storing a circulation liquid, a circulation pipe 105 circulating a fluid mixture of hydrogen gas and the circulation liquid to the ejector, and a circulation pump 104 is provided in a discharge line 12 for hydrogen gas produced by electrolysis, a hydrogen gas discharge pipe 106 and a first valve V1 are provided in the storage tank 103, impurities in the hydrogen gas are transferred to the circulation liquid to remove the impurities from the hydrogen gas, and a pressure of the hydrogen gas stored in the storage tank 103 is raised by controlling a flow rate of the circulation liquid circulated from the storage tank 103 to the ejector 110 and opening and closing of the first valve V1.

Abstract: An organic hydride production apparatus includes: an electrolyte membrane having proton conductivity; a cathode, provided on one side of the electrolyte membrane, that contains a cathode catalyst used to hydrogenate a hydrogenation target substance using protons to produce an organic hydride; an anode, provided opposite to the one side of the electrolyte membrane, that contains an anode catalyst used to oxidize water to produce protons; and an anode support, provided opposite to the electrolyte membrane side of the anode, that supports the anode. The anode support is formed of an elastic porous body of which the Young's modulus is greater than 0.1 N/mm2 and less than 43 N/mm2.

Abstract: An apparatus (100) for producing an acidic aqueous solution includes: an electrodialyzer (110) that has a monovalent ion perm-selective ion-exchange membrane and separates wastewater containing chloride ions and alkali metal ions into electrodialysis concentrated water and electrodialysis diluted water by an electrodialysis treatment; an electrolyzer (120) includes an anode that that electrolyzes the electrodialysis concentrated water to produce an acidic aqueous solution; and a first circulator (13) that circulates at least some of the acidic aqueous solution to the wastewater supplied to the electrodialyzer (110), and that adjusts a pH of the wastewater supplied to the electrodialyzer to 3 to 9.

Abstract: An object of the present invention is to provide an electrolysis technique such that the electrolysis performance is unlikely to be deteriorated, and excellent catalytic activity is retained stably over a long period of time even when electric power having a large output fluctuation, such as renewable energy, is used a power source, and this object is realized by an alkaline water electrolysis method, in which an electrolytic solution obtained by dispersing a catalyst containing a hybrid cobalt hydroxide nanosheet (Co-NS) being a composite of a metal hydroxide and an organic substance is supplied to an anode chamber and a cathode chamber that form an electrolytic cell, and the electrolytic solution is used for electrolysis in each chamber in common, and an alkaline water electrolysis anode.

Abstract: The chamber frame element of the present invention, which has a smaller amount of voltage drop, consumes less reactive power than the prior art, and exhibits no metal corrosion, is a chamber frame element (14) for an electrolyzer or an electrodialysis cell. The chamber frame element (14) includes: a bag body (141); a frame (142) housed in an interior space of the bag body (141); and an inlet (143) and an outlet (144) to which piping can be attached, which are formed on the outer side of a region where the frame is housed in the bag body (141).

Abstract: The chamber frame element of the present invention, which has a smaller amount of voltage drop, consumes less reactive power than the prior art, and exhibits no metal corrosion, is a chamber frame element (14) for an electrolyzer or an electrodialysis cell. The chamber frame element (14) includes: a bag body (141); a frame (142) housed in an interior space of the bag body (141); and an inlet (143) and an outlet (144) to which piping can be attached, which are formed on the outer side of a region where the frame is housed in the bag body (141).

Abstract: To provide an electrolysis cell for producing an organic chemical hydride capable of advancing a reduction reaction in a cathode of an organic compound having an unsaturated bond with high current efficiency and a small electric power consumption unit.