Lightweight High Yield Borazane-fed Hydrogen Generator

There is an urgent need for a stable and high energy density hydrogen source for portable military applications. 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 source of hydrogen for use in fuel cells. The hydrogen can be liberated via hydrolysis with a throttleable hydrolysis reactor producing a quantitative 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 with a practical 10.05 wt% hydrogen release (combined reactants basis). Lynntech proposes developing a self-sustained 20 Watt power supply system comprised of a hydrogen generator and 20W PEM fuel cell stack. This means that a soldier requiring 20W of continuous power will only require about 280 g of fuel (when the hydrogen is consumed at a 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.