To make it possible to detect whether leakage is external leakage or cross leakage in a water electrolyzer, a valve installed in an oxygen-side path, and a valve installed in a hydrogen-side path are closed; a water electrolysis reaction at a water electrolytic cell is progressed, and leakage in the oxygen-side path and leakage in the hydrogen-side path are determined based on the change in an internal pressure; and a differential pressure is made between the oxygen-side path and the hydrogen-side path, and leakage from a solid polymer electrolyte membrane is determined based on the change in the differential pressure.

A process for the preparation of a membrane electrode assembly comprising providing, in the following layer order, (I) a green supporting electrode layer comprising a composite of a mixed metal oxide and Ni oxide; (IV) a green mixed metal oxide membrane layer; and (V) a green second electrode layer comprising a composite of a mixed metal oxide and Ni oxide; and sintering all three layers simultaneously.

A pressure releasing method in a water electrolysis system including a water electrolyzer, the pressure releasing method includes operating the water electrolyzer to electrolyze water to produce oxygen with a first pressure on an anode side and hydrogen with a second pressure higher than the first pressure on the cathode side. It is determined whether the water electrolyzer is in a frozen environment when the water electrolysis system stops operating. The cathode side is depressurized without suppling a depressurizing current to the water electrolyzer if it is determined that the water electrolyzer is in the frozen environment, or with suppling the depressurizing current to the water electrolyzer if it is determined that the water electrolyzer is not in the frozen environment.

A differential pressure water electrolysis apparatus includes high-pressure water electrolysis cells and a pressing mechanism. The high-pressure water electrolysis cells are stacked in a stacking direction. Each of the high-pressure water electrolysis cells includes an electrolyte membrane, a member, an anode current collector, a cathode current collector, an anode separator, and a cathode separator. The electrolyte membrane has a first side and a second side opposite to the first side in the stacking direction. The member has a surface which has an opening and which is in contact with the electrolyte membrane. The anode current collector is disposed on the first side of the electrolyte membrane. The cathode current collector is disposed on the second side of the electrolyte membrane. The anode separator has an anode chamber in which the anode current collector is accommodated. The pressing mechanism is to press the high-pressure water electrolysis cells in the stacking direction.

The disclosure relates, inter alia, to a system comprising: (1) an electric power grid; (2) an electrolyzer generating a first stream of hydrogen in communications link with the electric power grid; (3) hydrogen production means for producing a second stream of hydrogen, said hydrogen production means being a non-electrolyzer in communications link with the electrolyzer; (4) a first conduit leading to a hydrogen user through which hydrogen flows to the hydrogen user; (5) a second conduit connecting the electrolyzer to the first conduit through which hydrogen from the electrolyzer flows to the first conduit at a first location; (6) a third conduit distinct from the second conduit connecting the non-electrolyzer to the first conduit through which hydrogen from the non-electrolyzer flows to the first conduit at a second location distinct from the first location; and (7) means for controlling and maintaining a continuous flow of hydrogen to the hydrogen user.

A dual gas flow device including: a first cooling plate structure, a second cooling plate structure, a plurality of electrode plates, wherein the first cooling plate structure, the second cooling plate structure and the plurality of electrode plates are arranged in a stacked configuration, wherein the first cooling plate structure forms a first end of the stack and the second cooling plate structure forms a second end of the stack, wherein the plurality of electrode plates are arranged between the first cooling plate structure and the second cooling plate structure, wherein each electrode plate includes a plurality of cooling channels extending through the electrode plate, distributed along a peripheral portion of the electrode plate, each cooling channel being aligned with the corresponding cooling channel of the other electrode plates in the stack, wherein each of the first cooling plate structure and the second cooling plate structure is provided with a plurality of connecting channels, each connecting channel being configured to connect adjacent pairs of cooling channels of the electrode plates, whereby the first cooling plate structure forms a return path for cooling fluid at the first end of the stack and the second cooling plate structure forms a return path for cooling fluid at the second end of the stack enabling cooling fluid to flow through all of the cooling channels.

A dual gas flow device including: a first cooling plate structure, a second cooling plate structure, a plurality of electrode plates, wherein the first cooling plate structure, the second cooling plate structure and the plurality of electrode plates are arranged in a stacked configuration, wherein the first cooling plate structure forms a first end of the stack and the second cooling plate structure forms a second end of the stack, wherein the plurality of electrode plates are arranged between the first cooling plate structure and the second cooling plate structure, wherein each electrode plate includes a plurality of cooling channels extending through the electrode plate, distributed along a peripheral portion of the electrode plate, each cooling channel being aligned with the corresponding cooling channel of the other electrode plates in the stack, wherein each of the first cooling plate structure and the second cooling plate structure is provided with a plurality of connecting channels, each connecting channel being configured to connect adjacent pairs of cooling channels of the electrode plates, whereby the first cooling plate structure forms a return path for cooling fluid at the first end of the stack and the second cooling plate structure forms a return path for cooling fluid at the second end of the stack enabling cooling fluid to flow through all of the cooling channels.

An energy storage system includes: a combustion turbine configured to output heated sweep gas; a reformer configured to receive natural gas and steam and to output reformed natural gas; a molten carbonate electrolyzer cell (“MCEC”) comprising an MCEC anode and an MCEC cathode, wherein the MCEC is configured to operate in a hydrogen-generation mode in which: the MCEC anode receives the reformed natural gas from the reformer, and outputs MCEC anode exhaust that contains hydrogen, and the MCEC cathode is configured to receive heated sweep gas from the combustion turbine, and to output MCEC cathode exhaust; and a storage tank configured to receive the MCEC anode exhaust that contains hydrogen.

An energy storage system includes: a combustion turbine configured to output heated sweep gas; a reformer configured to receive natural gas and steam and to output reformed natural gas; a molten carbonate electrolyzer cell (“MCEC”) comprising an MCEC anode and an MCEC cathode, wherein the MCEC is configured to operate in a hydrogen-generation mode in which: the MCEC anode receives the reformed natural gas from the reformer, and outputs MCEC anode exhaust that contains hydrogen, and the MCEC cathode is configured to receive heated sweep gas from the combustion turbine, and to output MCEC cathode exhaust; and a storage tank configured to receive the MCEC anode exhaust that contains hydrogen.

Disclosed is an end assembly for use in a unipolar filter press electrolyser, where the unipolar filter press electrolyser has a filter press stack. The end assembly of the unipolar filter press electrolyser includes an end plate component having two apertures, the two apertures being alignable with channels formed in the filter press stack. The two apertures include a first aperture configured to receive a stream of liquid electrolyte and gases from the filter press stack, and a second aperture configured to receive a stream of recirculated liquid electrolyte. In addition, the end assembly includes an end clamp configured to apply a clamping force on the end plate component to securely retain the filter press stack. The end clamp includes one gas offtake port to extract gases from the stream of liquid electrolyte and gases from the first aperture and discharge the gases out of the unipolar filter press electrolyser.