Producing fuel out of polluted air, using it to power industry and taking the emissions from that industry back out of the air in order to generate more fuel – it sounds too good to be true.
However, while there are a few obstacles to clear, a team headed by
University of Toronto’s Geoffrey Ozin of the department of chemistry in the Faculty of Arts & Science is getting closer to finishing the carbon cycle.
Closing the carbon cycle by U of T's Geoffrey Ozin: The diorama will open in December at Austria’s Museum of Applied Arts in Vienna (Photo by Peter Weibel)
“Carbon dioxide's so frustrating because it's the most stable molecule on the planet,” says University Professor Ozin of the climate pollutant that outlives soot, methane and hydrofluorocarbons by a long shot.
That's the problem. Anything you burn becomes CO 2 and CO 2 is really good at staying CO 2.
Geoffrey Ozin, Professor, The Department of Chemistry, University of Toronto
Ozin, holds the Canada Research Chair of materials chemistry and nanochemistry.
For the past five years, Ozin has headed a multidisciplinary team known as the U of T Solar Fuels Cluster on a quest to come up with a process to transform atmospheric CO
2 into a renewable fuel. Ozin explains that his plan for manufacturing the fuel would take as much carbon dioxide out of the atmosphere as burning the fuel would put back in.
The efforts put forth by the team have attracted the attention of major global corporations, and also inspired an exhibit about the process that has been on display in Germany – a global leader in CO
2 reclamation – and more recently in Austria.
The quest to make fuel out of waste carbon is not new, but Ozin and his team are considered to be the only ones using both the light and heat of the sun in order to convert CO
2, hoping their process will be more efficient than anyone else’s.
Ozin’s work recently caught the attention of the Director of the Center for Art and Media in Karlsruhe, Germany, which focuses on multimedia exhibits at the confluence of art and science. The result was an intense diorama representing Ozin’s vision that has been met with praise in Karlsruhe and will open in December at Austria’s Museum of Applied Arts in Vienna.
It is not the first time Ozin’s research has been immortalized in art. In 2011, American artist Todd Siler began developing multimeter-tall abstract sculptures of Ozin’s nano-structures, displaying them in such places as the Armory Show, New York City’s premier art fair.
There were human-sized nano rods, sheets, self-assembly, applications in energy, climate change. I lost my voice by the end of the week explaining it to all the visitors. We got two main comments: 'I like the colours' and 'What the hell does it all mean?'
Ozin is presently working with a dozen U of T fourth-year chemical engineering students to design and then build a pilot-scale version of his laboratory demonstration 'solar refinery’ linked to U of T's physical plant.
"There are different ways of doing this and maybe different methods will be more useful in some parts of the world than others,” says Ozin. “Some places have more wind, some places are sunnier, some have more water,” he says. “Everybody's pushing their method to valorize CO 2 capture and conversion and when the public sees someone holding a gallon of gasoline that's been pulled out of thin air, that's going to shake them up.
If you want to do this on a gigaton-scale, the way that we're doing it is the way to go.
How Ozin’s ‘photoreactors’ would produce a carbon-neutral cycle:
Renewable electricity is used for driving current through water, teasing out hydrogen gas that can be used for providing a feed stock for reaction with CO
2. Renewable energy captures CO
2 – for instance, from high CO 2-emission sources such as power stations, cement and steel factories, or even from dilute CO 2 sources in air. Once captured into the reactor, sunlight begins to drive the conversion of CO
2 and hydrogen when it comes into contact with catalysts produced from of nano-structured metal oxides and composites with nano-scale metals or various other nano-scale metal oxides engineered by Ozin and team. Ultra black in color, the surface of these nano-catalysts absorbs more than 90% of the sunlight spectrum – from ultraviolet to visible to infrared wavelengths – driving thermo- and photochemical reactions that turn hydrogen gas and CO
2 into synthetic fuels.
“When a black nano-material absorbs light, it gets very hot at the nano-scale, so you get very high local temperatures at the surface of these nano materials,” says Ozin. “So I don't need fossil fuels to drive the conversion. With just the sun, I can get 500 C at the nano-scale because the heat builds up as vibrational or electronic energy, confined to the surface of the catalyst nanoparticles where the CO 2 chemical conversion to synthetic fuels is occurring. That's photothermal catalysis – it utilizes wavelengths of the incident light across the entire solar spectrum to transform CO 2 to synthetic fuels – and it is a process we have patented."
Based on the structure and composition of these catalysts, and also the reaction conditions – pressure and temperature – the fuel material produced can be customized in order to produce carbon monoxide, methanol or methane, potentially ready for use in buildings, factories, engines and more.
Ozin states that all of this is a way to enable the catalysts to be more efficient.
“If we can be half a per cent more efficient than everyone else, that's a big deal when you're dealing in hundreds of millions of tons,” he says. “If you can drive it all through sunlight, that's new. And if you can drive the surface reaction chemistry through light, that's our contribution.”