(DE19522989-A1)      Hydrogen is generated by the reaction of alkali metal hydrides or alkaline earth metal hydrides with H2O. A hydride holder (35) is in close contact with the hydride contained and distributed in it. A water-feeding medium (33) is also in close contact with the hydride holder (35) and takes up water and supplies it by capillary action.    The hydride holder (35) is made of stiff corrugated material which is perforated. The water-feeding medium (33) is a sheet or mat made of inorganic or organic fibres. Heat is eliminated from the device by a casing or a jacket (13). The casing may be a cylindrical cartridge with a water feed pipe fitted. The casing may be a flat container (50), incorporating a water storage material (41) in a holder (42). The water storage material (41) is a water-absorbing macroporous material. The water-feeding medium (33) which H2 cannot pass through and the holder (42) are separated from each other. The container (50) may incorporate a valve. It may be a throw-away item, carrying water in excess of that required for the reaction and made of a cellulose material.    USE -   For the generation of H2 on demand, for example for filling meteorological balloons or for supplying fuel cells in unmanned submarines.    ADVANTAGE -   Hydrogen can be generated in accordance with quantitative demand. The device avoids the use of excess water to fully react the hydride.    (US5833934-A)      Load responsive hydrogen generator for releasing H2 from a particle hydride bed comprises:    (a) an enclosed housing adapted for contg. hydrogen gas under pressure;    (b) an hydride storage compartment disposed within the housing for storing a mass of hydride particles dispersed in a matrix, and further including a corrugated, perforated support structure adapted to accommodate volumetric expansion of the hydride particles upon conversion of hydrogen to hydroxide;    (c) a liquid water storage removed from the hydride storage compartment, the liquid water storage structure including a macroporous water absorbent material for storing liquid water;    (d) a liquid water transfer device disposed between the liquid water storage structure and the hydride storage compartment for permitting passage of the liquid water from the storage structure to the hydride storage compartment, the transfer device being impervious to passage of hydrogen gas from the hydride storage compartment to the liquid water storage structure while permitting passage of liquid water storage structure to the hydride storage compartment;    (e) a distributor for receiving the liquid water from the liquid water transfer device and for distributing the liquid water directly to the hydride particles, thereby permitting hydriding reaction to generate hydrogen gas into the hydride storage compartment; and    (f) a gas communicating device for removing the hydrogen gas from the hydride storage compartment upon load demand.    USE -   The generator is used for releasing hydrogen gas from a particle hydride bed as demand for hydrogen warrants, e.g. for filling meteorological balloons, for electric power generation in fuel cells.    ADVANTAGE -   The combination of the corrugated cartridge structure and the wicking material dispersed throughout the cartridge allows complete utilisation of the hydride and water in a demand responsive mode.