Aluminium Pucks Fuel Hydrogen Trucks

In the race toward a future free from fossil fuels, hydrogen is rapidly gaining ground. On paper, hydrogen sounds fantastic — it’s clean-burning with zero emissions, the refuel time is much faster than electric, and hydrogen-fueled vehicles can go longer distances between refuels than their outlet-dependent brethren.

The reality is that hydrogen vehicles usually need fuel cells to convert hydrogen and oxygen into electricity. They also need pressurized tanks to store the gases and pumps for refueling, all of which adds weight, takes up space, and increases the explosive potential of the system.

Kurt Koehler has a better idea: make the hydrogen on demand, in the vehicle, using a solid catalyst and a simple chemical reaction. Koehler is the founder of Indiana-based startup AlGalCo — Aluminium Gallium Company. After fourteen years of R&D and five iterations of his system, the idea is really starting to float. Beginning this summer, these pucks are going to power a few trucks in a town just outside of Indianapolis.

AlGalCo’s hydrogen-on-tap (HOT) system has none of the bulky and dangerous trappings of other hydrogen vehicles. Instead, it uses solid pucks of an alloy of aluminium and gallium to instantly create hydrogen whenever it’s needed. The moment these pucks come into contact with water, a chemical reaction begins, and the water molecules are split into hydrogen and oxygen. The resulting hydrogen gas is captured and sent immediately to the intake manifold to fuel the engine. Here’s the best part: the oxygen binds with aluminium and becomes aluminium oxide powder, which can be turned into new pucks indefinitely with the addition of more gallium.

This summer, the city of Carmel, Indiana is running a trial on five of their street department’s existing gasoline-engine trucks. These trucks will be retrofitted with the hydrogen-on-tap system, which consists of a metal box with six canisters that sit in the truck bed just behind the cab. The hydrogen is pumped underneath the bed and into the engine. Each day, the trucks will start out running on hydrogen and automatically switch over to gas when all the canisters full of alloy pucks are spent. When they roll back into the motor pool, the canisters can be swapped out for fresh ones in a matter of minutes. Testing has shown that the system brings a 15% improvement in gas mileage to these trucks, and a 20% reduction in carbon dioxide emissions.

Kurt Koehler has been developing this hydrogen-on-tap system at Purdue University for the last 14 years, but the technology itself is much older. The HOT system is based on the work of Jerry Woodall, who discovered the chemical reaction in 1968 while he was developing aluminium gallium arsenide compound that gave us the cheap and energy-efficient red LEDs now used in brake lights, traffic lights, and DVD players.

Woodall was trying to grow crystals in a solution of aluminium and liquid gallium. When he rinsed out his crucible with water, there was a violent, gas-emitting chemical reaction. That gas turned out to be hydrogen. Over time, he tried using less gallium.

Below is part one of a two-part video of Kurt demonstrating the previous iteration of the HOT system, including the awesome chemical reaction that goes on inside an AlGalCo canister. (Link to part 2)

We think this is a fantastic step toward widespread adoption of hydrogen power, and the hydrogen-gasoline hybrid trials will probably win the idea a lot of support. Solid fuel is easier to store and transport, and this particular fuel seems to be non-volatile as long as it stays dry.

All five of the Carmel city trucks should be running by the end of June. If you happen to live anywhere near central Indiana, Koehler gives weekly demonstrations of the technology at the Carmel street department’s garage. AlGalCo plans to adapt the system for use in diesel trucks and delivery vans, and already has interest from New York City officials.