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: 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: 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: 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: Provided is an alkaline water electrolyzer in which leakage of aqueous alkali solutions is prevented. The alkaline water electrolyzer 10 includes an anode chamber frame 11 defining an anode chamber 12; a cathode chamber frame 17 defining a cathode chamber 18; a porous diaphragm 16 disposed between the anode and cathode chamber frames 11 and 17 and partitioning the anode and cathode chambers 12 and 18; an anode gasket 15 disposed on the anode chamber frame 11; and a cathode gasket 21 disposed on the cathode chamber frame 17, wherein when the anode and cathode chamber frames 11 and 17 are fastened, the porous diaphragm 16 is held between the anode and cathode chamber frames 11 and 17 via the anode and cathode gaskets 15 and 21 and the anode and cathode gaskets 15 and 21 are in contact with each other around the peripheral edge of the porous diaphragm 16 by compressing the anode and cathode gaskets 15 and 21.

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.

Abstract: An organic hydride production apparatus that enables the reduction reaction at the cathode of an organic compound having an unsaturated bond to proceed at high current efficiency and at a low electric power consumption rate, and a method for producing an organic hydride that uses this production apparatus.

Abstract: A diaphragm includes a porous supporting body and a polymer porous membrane. When one of surfaces of the porous membrane is defined as a surface A, the other surface opposite to the surface A is defined as a surface B, a section of the porous membrane parallel to the surfaces A and B is defined as a section C, an average pore diameter on the surface A is defined as an average pore diameter DA, an average pore diameter on the surface B is defined as an average pore diameter DB, and an average pore diameter on the section C is defined as an average pore diameter DC, the average pore diameters DA and DB are substantially equal to each other, and the average pore diameter DC is larger than each of the average pore diameters DA and DB.

Abstract: Provided is a method capable of producing, in a simple and low-cost manner, an electrolysis electrode which can be used in alkaline water electrolysis and has superior durability against output variation. The method for producing an anode for alkaline water electrolysis includes: a step of dissolving lithium nitrate and a nickel carboxylate in water to prepare an aqueous solution containing lithium ions and nickel ions, a step of applying the aqueous solution to the surface of a conductive substrate having at least the surface composed of nickel or a nickel-based alloy, and a step of subjecting the conductive substrate to which the aqueous solution has been applied to a heat treatment at a temperature within a range from at least 450° C. to not more than 600° C., thereby forming a catalyst layer composed of a lithium-containing nickel oxide on the conductive substrate.

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: Provided is an alkaline water electrolysis method capable of reducing or preventing degradation in cathode and anode performance even in an operation of repeated cycles of frequent starting and stopping, and/or even in an operation involving a significant output variation.

Abstract: Provided is a water treatment system using an alkaline water electrolytic device and an alkaline fuel cell in which for continuing an electrolytic treatment, a hydrogen gas and an oxygen gas required in an alkaline water electrolytic device and an alkaline fuel cell, an amount of water corresponding to raw water lost through the electrolytic treatment, and an electrolytic solution are efficiently circulated and used in a water treatment system to considerably reduce electric power consumption.

Abstract: Provided is an alkaline water electrolyzer in which leakage of aqueous alkali solutions is prevented. The alkaline water electrolyzer 10 includes an anode chamber frame 11 defining an anode chamber 12; a cathode chamber frame 17 defining a cathode chamber 18; a porous diaphragm 16 disposed between the anode and cathode chamber frames 11 and 17 and partitioning the anode and cathode chambers 12 and 18; an anode gasket 15 disposed on the anode chamber frame 11; and a cathode gasket 21 disposed on the cathode chamber frame 17, wherein when the anode and cathode chamber frames 11 and 17 are fastened, the porous diaphragm 16 is held between the anode and cathode chamber frames 11 and 17 via the anode and cathode gaskets 15 and 21 and the anode and cathode gaskets 15 and 21 are in contact with each other around the peripheral edge of the porous diaphragm 16 by compressing the anode and cathode gaskets 15 and 21.

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: To provide an electrolytic apparatus and an electrolytic method which can remove a risk of reaching an explosion limit of hydrogen by gradual accumulation of a very small amount of gas in a circulation line of an electrolytic solution in an electrolytic process generating hydrogen. The electrolytic apparatus 1 is characterized by including an anode gas feeding line 20 connecting a gas phase region 21 to an anode side gas-liquid separation means in order to dilute the concentration of the hydrogen gas by feeding anode gas into the gas phase region 21 in which hydrogen gas can exist as a gas phase. By feeding at least a part of the anode gas to the gas phase region 21 with the anode gas feeding line 20, the hydrogen gas in the gas phase region 21 is diluted with the anode gas so that the concentration of the hydrogen gas is surely less than a lower limit value of explosion limit.

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 a method capable of producing, in a simple and low-cost manner, an electrolysis electrode which can be used in alkaline water electrolysis and has superior durability against output variation. The method for producing an anode for alkaline water electrolysis includes: a step of dissolving lithium nitrate and a nickel carboxylate in water to prepare an aqueous solution containing lithium ions and nickel ions, a step of applying the aqueous solution to the surface of a conductive substrate having at least the surface composed of nickel or a nickel-based alloy, and a step of subjecting the conductive substrate to which the aqueous solution has been applied to a heat treatment at a temperature within a range from at least 450° C. to not more than 600° C., thereby forming a catalyst layer composed of a lithium-containing nickel oxide on the conductive substrate.

Abstract: A device for producing an organic hydride 10 of an aspect of the present invention has an electrochemical cell provided with an anode 12 on a surface of an electrolyte membrane 11 and a cathode including a cathode catalyst layer 13 and a cathode diffusion layer 14 on another surface of the electrolyte membrane 11. A gap is provided between the anode 12 and the electrolyte membrane 11. The anode 12 has a network structure with an aperture ratio of 30 to 70%, and has an electrical supply supporting material formed of an electronic conductor and the electrode catalyst held by the electrical supply supporting material.

Abstract: Provided is an alkaline water electrolysis method capable of reducing or preventing degradation in cathode and anode performance even in an operation of repeated cycles of frequent starting and stopping, and/or even in an operation involving a significant output variation.