Timing of HHO gas injection into a 4-stroke engine is optimized based on engine operating parameters to improve fuel economy.

The invention relates to an electrolysis arrangement for the electrochemical production of hydrogen and oxygen from an alkaline electrolyte having anode and cathode separators for the separation of oxygen and hydrogen from the electrolyte, and an anode and cathode pipe system to circulate electrolyte between anode and cathode sections of an electrolysis stack of the electrolysis arrangement. Control valves and interconnections are configured so that dependent on an electrolyte flow rate passing first, second and third control valve, oxygen and hydrogen depleted electrolyte withdrawn from the separators can be supplied unmixed, partly mixed or fully mixed to the anode and cathode sections of the electrolysis stack to control hydrogen to oxygen and oxygen to hydrogen crossover in the electrolysis arrangement.

An apparatus is provided for generating hydrogen and oxygen through alkaline electrolysis. A process is also provided for generating hydrogen and oxygen through alkaline electrolysis using the apparatus. The apparatus and process are advantageously applied in apparatuses and systems for the accumulation of hydrogen using demineralized water and electric energy, also coming from renewable sources.

An apparatus is provided for generating hydrogen and oxygen through alkaline electrolysis. A process is also provided for generating hydrogen and oxygen through alkaline electrolysis using the apparatus. The apparatus and process are advantageously applied in apparatuses and systems for the accumulation of hydrogen using demineralized water and electric energy, also coming from renewable sources.

An alkaline water electrolysis system includes: a plurality of reaction chambers, each including a main electrode and an auxiliary electrode; a piston provided in each reaction chamber to change a volume of the reaction chamber through reciprocating motion; a drive motor; a connecting rod and a crankshaft installed to change rotational motion of the drive motor into reciprocating linear motion of the piston; a plurality of gas valves installed on an upper side of the reaction chamber to discharge hydrogen and oxygen generated in the reaction chamber through different paths, respectively; a pressure sensor installed in the reaction chamber; a controller configured to open and close the gas valves in response to a signal received from the pressure sensor; and an electrolyte supply apparatus provided to supply an electrolyte to the reaction chambers.

A water electrolysis system includes a water supply unit, a KOH tank, a water electrolysis apparatus, and a control device. The water supply unit and the KOH tank supply an aqueous solution containing hydroxide ions of a predetermined concentration to a cathode of the water electrolysis apparatus. The water electrolysis apparatus includes a solid polymer electrolyte membrane, and a water electrolysis cell having an anode and a cathode provided on both sides of the solid polymer electrolyte membrane. The control device changes the voltage to increase while restricting a supply amount of a KOH aqueous solution to the cathode when a concentration of the KOH aqueous solution is higher than a predetermined reference concentration on the basis of information on correspondence between a voltage and current between the anode and the cathode and the concentration of the KOH aqueous solution on the cathode.

A high-pressure electrolyzer assembly includes a pressure vessel having two dome-shaped ends, and an electrolyzer arranged inside the pressure vessel. The pressure vessel is pressurized using an inert gas or a process gas of the electrolyzer. A vehicle may include at least one such electrolyzer assembly.

A high-pressure electrolyzer assembly includes a pressure vessel having two dome-shaped ends, and an electrolyzer arranged inside the pressure vessel. The pressure vessel is pressurized using an inert gas or a process gas of the electrolyzer. A vehicle may include at least one such electrolyzer assembly.

The invention relates to an electrolysis arrangement for the production of hydrogen and oxygen by alkaline electrolysis. The electrolysis arrangement includes a system configuration which enables to balance the lye concentrations between the anode and cathode section of the arrangement depending on the current density of the direct current supplied to the electrolysis stack of the electrolysis medium. At high current densities, hydrogen to oxygen crossover and oxygen to hydrogen crossover is low, which allows full mixing of electrolysis media to balance the concentration between anolyte and catholyte. At low current densities, hydrogen to oxygen crossover and oxygen to hydrogen crossover is high. Therefore, the electrolysis arrangement is configured so that the mixing of the electrolysis media is decreased in case a current density of a direct current supplied to the electrolysis stack is decreased.

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. An electrolyzer gasket including a picture-frame-shaped thin-plate-like frame having a first surface being in contact with an anode metal frame and a second surface being in contact with a cathode metal frame, wherein the gasket has a structure in which a notch having a difference in level of approximately the same thickness as the thickness of the separator, the notch obtained by thinly scraping off, in a uniform thickness, a region including the edge on the anode chamber side or the cathode chamber side, is formed on any one of the first surface and the second surface, and the edge part of the separator is accommodated and held in the notch, and an electrolyzer using the electrolyzer gasket.