Lightweight High Yield Borazane-fed Hydrogen Generator

With 19.6 wt% hydrogen in its composition, borazane (NH3BH3), a water soluble, non-cryogenic solid, is one of the most hydrogen rich solids around, and a promising means to deliver hydrogen for use in fuel cells. The hydrogen can be liberated by either hydrolysis or pyrolysis with a throttleable hydrolysis reactor producing a higher hydrogen yield from a given mass of borazane with no need for a pressure vessel and no high temperature heat signature. In this system hydrogen is generated at near ambient temperature through the catalyzed hydrolysis of an aqueous borazane solution. Lynntech proposes to develop a lightweight generator to produce hydrogen on demand through the controlled hydrolysis of borazane using water of almost any quality. This means that a soldier requiring 20 W of continuous power will only require about 400 g of fuel with an energy density of 3.6 Wh (when the hydrogen is consumed at typical fuel cell efficiency) and produce a net system energy density of =1.5 kWh/kg (including water that can be collected locally) for a 72 hr mission. To match a variable power demand, the rate of hydrogen generation can be varied to maximize the utilization of borazane.