Aluminum + Water + Secret Sauce = Low-Cost Hydrogen Fuel

Chemical engineers know better than anyone the difficulties in turning a promising lab curiosity into an actual product. Consider, for example, aluminum-water reactions as a means for generating hydrogen gas. For decades, researchers have been trying to tap the commercial potential of these reactions, which have the potential to produce hydrogen without the high costs and energy inefficiency of steam reforming and electrolysis techniques and systems. Over the years, there have been scores of patents and technical papers documenting efforts to harness the hydrogen-generating power of aluminum-water reactions.

By and large, these efforts have remained in the lab because of the thorny chemistry and engineering development challenges associated with the commercialization and “productization” of the technology.

Until now. AlumiFuel Power, Inc., this month introduced a new aluminum-water reactor system called the Portable Balloon Inflation System, or PBIS-1000. Unlike other hydrogen generation technologies, this portable hydrogen generator requires no external energy whatsoever.  All it needs is freshwater or salt water in its tank and a pair of AlumiFuel 32-ounce cartridges containing aluminum powder along with proprietary additives and packing materials. To initiate the reaction and start generating hydrogen, users open the cartridge and insert it into the unit’s stainless-steel reaction chamber, where it is punctured by a needle that allows the water to be pumped in by hand. A two-cartridge PBIS system fits in a two-foot cube with room to spare and can generate 1,000 liters of hydrogen in about 20 minutes; this is enough lift gas to launch a 5-foot-diameter weather balloon. Yields for the system typically exceed 95%.

Though initially developed for inflating weather balloons in the field, this reactor technology can generate hydrogen for use in fuel cells. The current sweet spot for technology is portable, supplying backup and remote power in the range of 100 W to 5kW. Energy densities for the fuel are 9.2 kWh/L or 8.9 kWh/kg, or about four times the amount offered by current state-of-the-art battery technologies. The system also can produce hydrogen for a variety of niche applications that currently rely on hydrogen supplied in bulky, expensive K cylinders.

The aluminum-water-additive reaction isn’t just about hydrogen. Similar reactor designs can be used to harness the superheated steam from this highly exothermic reaction. In one promising class of applications, the steam can be used to drive turbines that power unmanned underwater vehicles (UUVs) and other submersibles for naval and commercial customers.

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Source: Engineering Cases - Knovel