NOVELTY - A hydrogen gas generation system comprises: a housing; a catalyst chamber; a fuel conduit; a hydrogen gas outlet in the housing; a gas permeable membrane; and optionally a throttle valve located in the fuel conduit.    USE - For generating hydrogen in fuel cells and combustion engines.    ADVANTAGE - The system provides environmentally safe and efficient storage of hydrogen gas; and minimizes volume, weight and complexity of hydrogen storage. Thus, the system provides compact and lightweight fuel cells; self-regulation of fuel flow; has a high gravimetric hydrogen density; and can be operable in any orientation.    DETAILED DESCRIPTION - A hydrogen gas generation system comprises:    (a) a housing that has a hydrogen separation chamber and a fuel storage chamber separated by a partition. The fuel storage chamber contains a fuel material capable of reacting to generate hydrogen gas;    (b) a chamber containing a catalyst that promotes the reaction of the fuel material to generate hydrogen and discharged fuel material;    (c) a fuel conduit for conveying the fuel material from the fuel storage chamber to the catalyst chamber, and an outlet conduit to convey the discharged fuel material from the catalyst chamber to the hydrogen separation chamber;    (d) a hydrogen gas outlet in the housing for discharging hydrogen from the hydrogen separation chamber;    (e) a gas permeable membrane located in wall of at least one of the fuel storage chamber or the hydrogen separation chamber. The membrane allows the passage of hydrogen gas and prevents that of an aqueous solution, discharged fuel or the fuel material to the hydrogen gas outlet; and    (f) optional throttle valve located in the fuel conduit. It controls the flow of fuel material from the fuel storage chamber to the catalyst chamber, and is responsive to the hydrogen gas passing through the hydrogen gas conduit.    INDEPENDENT CLAIMS are included for the following:    (1) a volume exchanging container for use in the hydrogen gas generating system comprising the hydrogen separation chamber and the fuel storage chamber separated by a flexible partition, and the gas permeable membrane; and    (2) a fuel container having a fuel outlet for removing the fuel material, the gas permeable membrane within the fuel container, and the hydrogen outlet formed in the fuel container to allow hydrogen gas to pass from a space outwardly from the fuel container. A portion of the container comprises a flexible material adapted to create a pressure on the fuel material so as to force fuel material outwardly through the fuel outlet. The membrane separates the fuel material from the space, and allows hydrogen gas generated by the fuel material to pass through the gas permeable membrane to the space while preventing the fuel material from entering the space.