Metal as fuel? These Canadian scientists are working to make it happen

Imagine one day fuelling your car with iron powder, rather than gasoline. That's the goal of some Canadian scientists who hope that metal will one day provide a cleaner, greener alternative for our vehicles.

Researchers at McGill University have been studying the combustion capabilities of metal for more than a decade. Last week, they launched an experiment into space to gain further insight to this yet untapped potential. The experiment was designed to help scientists better understand how the metal particles react in weightlessness.

While using metal as fuel might sound unusual, the concept has been around for quite some time. Andrew Higgins, one of the McGill researchers, says he's been studying it for about 20 years.

Metal fuel is created when a metal is ground into a powder, which is then fed into a burner. It's so efficient that more energy and heat is generated per litre of iron powder, compared to one litre of gas.

The key to its greenness is that it releases no carbon dioxide. Instead, it releases iron oxide: rust.

Not only that, but that iron oxide can be collected by a vacuum and then reused to burn again. It's a closed-loop system, Higgins told CBC News, and one that is far more efficient than other alternative fuels for vehicles, such as biofuels. 

Though the concept of using metal as fuels has been around for some time, applying it as a form green technology is somewhat new. 

But to make it truly "green," the researchers say, you need to ensure that whatever system is doing the recycling has its own clean energy source.

McGill researcher Jeffrey Bergthorson, who was not involved in last week's launch but who has been studying metal fuels for more than a decade, said that he'd like to think big: first ships and trains, and then trickle down to smaller vehicles, like cars.

Bergthorson also noted that Canada, rich with metals, could see great economic benefits by shipping iron for fuel to other countries. Ships could be powered on iron, carrying iron to other countries — like China, a country that is struggling with extreme air pollution, making it a truly closed-loop system.

"The whole idea is to close the loop," Bergthorson said. "The key idea … is to have energy that goes from one place to another, but the material just goes around and around and around without losses to the environment."

Future research

While battery technology is a green and clean energy source currently being used in vehicles, the problem is that in order to increase the range of a car or truck, the battery needs to get bigger. That's not the case with metal fuels. And that, both researchers say, is why metal fuel is the fuel of the future.

Using metals as a fuel source isn't completely new. NASA's space shuttle used about 16 per cent aluminum powder in its solid rocket boosters. However, what is new is the idea of incorporating it into common use and making it cleaner: the space shuttle wasn't able to collect the aluminum oxide it produced.

Bergthorson said that humanity needs to use some alternative thinking for alternative fuels.

"We have to expand our horizons, our vision of what a fuel is, and what are the possibilities. And when we look big enough, I think we find that metals are going to be the solution," he said. "I want a renewable, energy-rich future, and not an energy-poor future."

Unfortunately, there aren't many metal fuel researchers, Bergthorson said, and more are needed to advance the technology.

Higgins agrees.

"To put it all together into a real technology, we're going to need a lot of other people to help us on this," he said. "We hope people will continue to collaborate with us to keep advancing the technology."

Higgins sees a future where drivers pull into a station to refuel and, in turn, drop off their iron oxide for recycling. 

And, he jokes, it's almost a return to older times.

"Maybe the fuel of the future will be a return to the Iron Age."