Abstract: Apparatus for producing alkali hydroxide and method for operating apparatus for producing alkali hydroxide are provided. A cooling chamber through which a coolant can pass is constructed by placing a separation wall in a cathode chamber on a side opposite to an ion-exchange membrane, and a flow rate adjuster, such as manual valves, which can adjust the supply flow rate of the coolant is placed in each unit cell. The electrolytic temperature of each unit cell is regulated at an optimum operating temperature depending on the current density by adjusting the flow rate of the coolant without individually adjusting the flow rate of salt water supplied to the unit cell or the concentration of the salt water.

Abstract: A semiconductor device with favorable electrical characteristics is provided. A semiconductor device with stable electrical characteristics is provided. The semiconductor device includes a first insulating layer, a second insulating layer, a third insulating layer, a fourth insulating layer, a semiconductor layer, and a first conductive layer. The second insulating layer is positioned over the first insulating layer and the island-shaped semiconductor layer is positioned over the second insulating layer. The second insulating layer has an island shape having an end portion outside a region overlapping with the semiconductor layer. The fourth insulating layer covers the second insulating layer, the semiconductor layer, the third insulating layer, and the first conductive layer, is in contact with part of a top surface of the semiconductor layer, and is in contact with the first insulating layer outside the end portion of the second insulating layer.

Abstract: Apparatus for producing alkali hydroxide and method for operating apparatus for producing alkali hydroxide are provided. A cooling chamber through which a coolant can pass is constructed by placing a separation wall in a cathode chamber on a side opposite to an ion-exchange membrane, and a flow rate adjuster, such as manual valves, which can adjust the supply flow rate of the coolant is placed in each unit cell. The electrolytic temperature of each unit cell is regulated at an optimum operating temperature depending on the current density by adjusting the flow rate of the coolant without individually adjusting the flow rate of salt water supplied to the unit cell or the concentration of the salt water.

Abstract: Apparatus for producing alkali hydroxide and method for operating apparatus for producing alkali hydroxide are provided. A cooling chamber through which a coolant can pass is constructed by placing a separation wall in a cathode chamber on a side opposite to an ion-exchange membrane, and a flow rate adjuster, such as manual valves, which can adjust the supply flow rate of the coolant is placed in each unit cell. The electrolytic temperature of each unit cell is regulated at an optimum operating temperature depending on the current density by adjusting the flow rate of the coolant without individually adjusting the flow rate of salt water supplied to the unit cell or the concentration of the salt water.

Abstract: There is provided a method of production of chlorine.sodium hydroxide capable of being operated stably and economically by preventing calcium from being deposited in an ion exchange membrane. The liquid retention layer 3 having a liquid retention amount per unit volume of the liquid retention layer of 0.10 g-H2O/cm3 or more and 0.80 g-H2O/cm3 or less is put between the ion exchange membrane 12 and the gas diffusion electrode 16. Calcium ions transferred through the ion exchange membrane 12 easily diffuse, thereby making it possible to suppress increase in an electrolytic voltage and drop in current efficiency generated by deposition of the calcium ions inside the ion exchange membrane 12.

Abstract: Disclosed is an electrolysis method, whereby sodium chloride concentration of an aqueous caustic soda solution formed through electrolysis in a two-chamber ion-exchange membrane sodium chloride electrolytic cell, which is equipped with a gas diffusion electrode as a cathode and divided into an anode chamber containing an anode and a cathode gas chamber containing the cathode that are partitioned by an ion-exchange membrane, is lowered. In a two-chamber ion-exchange membrane electrolytic cell (1) using a gas diffusion electrode (7), electrolysis is performed while reducing the pressure difference between the liquid pressure in the anode chamber and the gas pressure in the cathode gas chamber, i.e.

Abstract: Provided is a gas diffusion electrode equipped ion exchange membrane electrolyzer including an anode, an ion exchange membrane, and a cathode chamber in which a gas diffusion electrode is disposed, wherein the ion exchange membrane and a cathode chamber inner space in which the gas diffusion electrode is disposed are separated by a liquid retaining member, the outer periphery of the liquid retaining member is held in a void formed in a gasket or a cathode chamber frame constituting the cathode chamber, or the outer periphery and the end face of the outer periphery of the liquid retaining member are sealed, or the outer periphery of the liquid retaining member is joined to and integrated with the gasket.

Abstract: There is provided a method of production of chlorine.sodium hydroxide capable of being operated stably and economically by preventing calcium from being deposited in an ion exchange membrane. The liquid retention layer 3 having a liquid retention amount per unit volume of the liquid retention layer of 0.10 g-H2O/cm3 or more and 0.80 g-H2O/cm3 or less is put between the ion exchange membrane 12 and the gas diffusion electrode 16. Calcium ions transferred through the ion exchange membrane 12 easily diffuse, thereby making it possible to suppress increase in an electrolytic voltage and drop in current efficiency generated by deposition of the calcium ions inside the ion exchange membrane 12.

Abstract: Provided is a gas diffusion electrode equipped ion exchange membrane electrolyzer including an anode, an ion exchange membrane, and a cathode chamber in which a gas diffusion electrode is disposed, wherein the ion exchange membrane and a cathode chamber inner space in which the gas diffusion electrode is disposed are separated by a liquid retaining member, the outer periphery of the liquid retaining member is held in a void formed in a gasket or a cathode chamber frame constituting the cathode chamber, or the outer periphery and the end face of the outer periphery of the liquid retaining member are sealed, or the outer periphery of the liquid retaining member is joined to and integrated with the gasket.

Abstract: Provided is a gas diffusion electrode equipped ion exchange membrane electrolyzer including an anode, an ion-exchange membrane, and a cathode chamber in which a gas diffusion electrode is disposed, wherein in a cathode gas chamber formed between a back plate of the cathode chamber and one side of the gas diffusion electrode opposite to the electrolytic surface, a gas-permeable elastic member is disposed between the gas diffusion electrode and the back plate, and the elastic member forms a conductive connection between the gas diffusion electrode and the back plate by making contact with corrosion-resistant conductive layers formed on the surfaces of a plurality of conductive members which are joined to the back plate.

Abstract: Disclosed is an electrolysis method, whereby sodium chloride concentration of an aqueous caustic soda solution formed through electrolysis in a two-chamber ion-exchange membrane sodium chloride electrolytic cell, which is equipped with a gas diffusion electrode as a cathode and divided into an anode chamber containing an anode and a cathode gas chamber containing the cathode that are partitioned by an ion-exchange membrane, is lowered. In a two-chamber ion-exchange membrane electrolytic cell (1) using a gas diffusion electrode (7), electrolysis is performed while reducing the pressure difference between the liquid pressure in the anode chamber and the gas pressure in the cathode gas chamber, i.e.