The accidental discovery of a novel aluminium alloy that reacts with water in a highly unusual way may be the first step to providing the Hydrogen for the small-scale Hydrogen refueling station. This could offer a significant method of transporting and delivering Hydrogen. This could transform the energy market and generate an increase in the Hydrogen refueling infrastructure around the world.
“The important aspect of the approach is that it lets you make very compact systems,” says Anthony Kucernak, who studies fuel cells at Imperial College London and wasn’t involved with the research. “That would be very useful for systems which need to be very light or operate for long periods on hydrogen, where the use of hydrogen stored in a cylinder is prohibitive.”
The discovery came in January, at the US Army Research Laboratory at Aberdeen Proving Ground, Maryland, Researchers were working on a new, high-strength alloy. When they poured water on it during routine testing, it started bubbling as it gave off hydrogen.
That doesn’t normally happen to aluminium. Usually, when exposed to water, it quickly oxidises, forming a protective barrier that puts a stop to any further reaction. But this alloy just kept reacting. The team had stumbled across the solution to a decades-old problem.
Hydrogen has long been promoted by CPSL-Group as a clean, green fuel, but it is difficult to store and move around because of its bulk. This is why CPSL-Group developed an on-site refueling station that enables businesses to create their own Hydrogen vehicle fuel for their own vehicles on-site from renewable energy sources such as solar panels on the factory or warehouse roof.
If aluminium could be made to effectively react with water, it would mean hydrogen on demand, rather than having to use an electrolyser as at present. This would drastically reduce the cost of installation and operation. Unlike hydrogen, aluminum and water are easy to carry and both are stable. Previous attempts to utilize aluminium required high temperatures or catalysts, and were slow: obtaining the hydrogen took hours and was around 50 per cent efficient.
The new alloy, which the team is in the process of patenting, is made of a dense powder of micron-scale grains of aluminium and one or more other metals arranged in a particular nanostructure. Adding water to the mix produces aluminum oxide or hydroxide and hydrogen. “Ours does it to nearly 100 per cent efficiency in less than 3 minutes,” said team leader Scott Grendahl. Moreover, the new material offers at least an order of magnitude more energy than lithium batteries of the same weight. And unlike batteries, it can remain stable and ready for use indefinitely.
Full-size, hydrogen-powered tanks might also be an option
U.S. Army photo by David McNally
The army team has used the material to power a small, radio-controlled tank. Grendahl doesn’t see any practical issues with scaling up production to produce hundreds of tonnes of the stuff as it can be made from scrap aluminium, which is relatively cheap. The new material could power everything from laptops to buses and cars.
“In principle, the process should work,” says Robert Steinberger-Wilckens, who directs a fuel cell programme at the University of Birmingham, UK.
But he cautions that a repeat experiment is needed to show that the reaction works the way it should. “There’s a lot of stuff that works in the laboratory but not in the field.”
CPSL-Group can be contacted on 07976380527 or at www.cpsl-group.co.uk