TECHNOLOGY FOCUS - CHEMICAL ENGINEERING - Preferred Components: The first composition is disposed on a first side of the first porous member, and a reservoir is disposed on a second side of the first porous member. The hydrogen gas generating device further comprises an inlet adapted for the introduction of the second composition into the device; an outlet adapted for the removal of hydrogen gas from the device; second porous member between the outlet and the first porous member; and desiccant between the first porous member and the outlet. The hydrogen-containing composition is present as a bed of particles, and the outlet is disposed on an opposing side of the bed from the first porous member. The device further includes a housing (103) that terminates on an end in the first porous member, and having a plug (133) with first and second opposing surfaces; and a spring (131) within the housing, and being compressed against a first surface of the plug. The dispenser comprises a spring-activated piston, or a piston consisting of pneumatic or hydraulic pistons. It is equipped with a pressurized bladder or a water-swellable material that presses the first composition against the porous member. The water-swellable material, the first composition, and the porous member are arranged in a series of alternating layers disposed in concentric or helical configuration, or in a stack of essentially planar layers. Preferred Materials: The second porous member is an open-celled polymeric foam (121). Preferred Properties: The first material is maintained in a state in which it is pressed against the porous interface with a spring, piston, or pressurized gas.    TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Materials: The first composition comprises a material consisting of hydrides, borohydrides, or boranes, preferably sodium borohydride. The second composition comprises water. The desiccant is consisting of hydrides, borohydrides, boranes, or their hydrates. The first porous member comprises a metal foam and the second composition comprises a chelating agent. The first composition is a solid material and the second composition is a liquid material. The first material reacts with the second material to evolve hydrogen gas and a mud-like reaction byproduct.