In a water electrolysis system and a method of controlling the water electrolysis system, a control device places a high pressure water discharge solenoid valve, a depressurizing solenoid valve, and a low pressure water discharge solenoid valve in the closed state. Further, a pressure acquisition unit obtains the electrolysis time pressure as a pressure in the low pressure water sealing container during production of hydrogen by a water electrolyzer. Further, the control device determines the occurrence of hydrogen leakage in a depressurizing line based on at least the electrolysis time pressure.

A dual-chamber electrolysis vessel safely stores HHO gas for use by an internal combustion engine.

An electrochemical cell has a membrane located between two flow field plates. On a first side of the membrane, there is a porous support surrounded by a seal between the membrane and the flow field plate. There is a gap between the porous support and the seal at the surface of the membrane. On a second side of the membrane, there is a seal between the membrane and the flow field plate located inside of the gap in plan view. The electrochemical cell is useful, for example, in high pressure or differential pressure electrolysis in which the second side of the membrane will be consistently exposed to a higher pressure than the first side of the membrane.

Among other things, a device for use in electrolyzing water is described. The device comprises an electrolysis unit that includes a chamber, an ion exchange structure in the chamber, a cathode, an anode, a high pressure chamber, and a reservoir. The chamber is separated by the ion exchange structure into a first compartment and a second compartment. The cathode is in the first compartment and the anode in the second compartment. The reservoir is disposed in the high pressure chamber for storing water to be supplied to the chamber of the electrolysis unit. In some implementations, the ion exchange structure is a proton exchange membrane.

A system for producing hydrogen gas comprises a pair of electrodes that are disposed at a predetermined water depth under water and configured to be connected to a power supply for electrolysis of water, a gas storage chamber that is disposed at the water depth, has communication holes through which surrounding water can flow in, and stores the hydrogen gas generated at a cathode of the pair of electrodes due to the electrolysis, a hydrogen recovery device disposed above the water depth, and piping configured to lead the hydrogen gas stored in the gas storage chamber to the hydrogen recovery device.

A carbon dioxide electrolytic device comprises: an electrolysis cell including a first electrode having a first catalyst to reduce carbon dioxide, a second electrode having a second catalyst to oxidize water or hydroxide ions, a first electrode flow path facing the first electrode, a second electrode flow path facing the second electrode, and a separator separating the first and second electrodes; a power controller; a first flow path through which the carbon dioxide flows; a second flow path through which the carbon compound flows; a third flow path through which an electrolytic solution containing the water flows; a fourth flow path through which the oxygen flows; a first valve to connect the first electrode flow path and the first flow path; a second valve to connect the first electrode flow path and the second flow path; a tank connected to the first electrode flow path and configured to store a rinse solution; and a controller programmed to control opening and closing of the first and second valves in accordance with performance requirements of the electrolysis cell.

A carbon dioxide electrolytic device includes: an electrolysis cell; a sensor acquiring data indicating a concentration of a first product containing a carbon compound in an anode flow path of the electrolysis cell; a power controller to apply a voltage between an anode and a cathode of the electrolysis cell; a refresh material source including a gas source to supply a gaseous substance to at least one selected from the group consisting of the anode and cathode flow paths, and a solution supply source to supply a rinse solution to at least one selected from the group consisting of the anode and cathode flow paths; and a controller programmed to stop supply of carbon dioxide and an electrolytic solution, and supply the rinse solution to at least one selected from the group consisting of the anode and cathode flow paths from the refresh material source, in accordance with the data.

A method of treating a carbon electrode includes heat treating a carbon-based electrode in an environment that is above approximately 325 C. and that includes an oxidizing gas, and prior to use of the carbon-based electrode in an electro-chemical battery device, soaking the carbon-based electrode in an oxidizer solution.

A module for an HTE reactor or an SOFC fuel cell, the module including a circuit for the circulation of a gas, in addition to the reactive gases required for the electrolysis reaction or the reverse reaction in an SOFC cell, the circuit enabling, during the operation under pressure, the additional gas to equalise, on one side of the glass- and/or vitroceramic-based seals, the pressure of the reactive gases generated on the other side.

An HHO gas stream for use in an internal combustion engine is heated by heat exchange from with an exhaust gas stream from the internal combustion engine.