A lightweight electrical power source is proposed consisting of a magnesium (or aluminum) hydride/water reactor hydrogen fuel source, a small fuel cell and accessories. This power pack will safely provide nominal power of 200 W using 800 Whr of fuel energy. At under 10 pounds (4.5 kg) and 0.2 ft3 (5.5 1.), the pack will be light enough for soldiers in the field. The power pack requires a water supply or addition of water before use begins. The hydride reaction of interest is MgH2 + 2H20 Mg(OH)2 + 2H2 +62 kcal. The Phase I effort includes introduction, removal and contacting of reactants and products for the fuel source reactor; controlled operation of the hydrogen production, including start-up and stopping; controlled heat release (heat losses are estimated to be about 60 percent of the body heat radiated by a soldier); and system packaging, including integration of the fuel cell and active cooling of the fuel cell, if required. Concepts to be examined include modular fuel packets, microencapsulation of hydride fuel, testing of nickel alloy with the hydrides, and reaction heat utilization such as micro-turbine operation or absorption cooling.
Keywords: magnesium hydride hydrogen fuel cell micro-encapsulation portable power
