Creating diesel out of thin air seems as possible as turning lead into gold, but some companies in Canada and Germany are taking a page out of the alchemy handbook and turning carbon dioxide into a renewable energy source. Sunfire Corporation manufactured its first shipment of “e-diesel” back in April. Johanna Wanka, Federal Minister of Education and Research, celebrated by putting a few liters in her car. And Canadian company Carbon Engineering recently produced 500 liters of diesel by implementing a pilot plant to suck up to two tons of carbon dioxide from the atmosphere daily.
The caveat is that the technique uses electricity to power the mechanism, but by using renewable electricity, it’s possible to manufacture diesel that is carbon neutral. Strictly speaking, burning off the diesel in your car will return the CO2 into the atmosphere that was expunged in the first place. On the other hand, fossil fuels only add more carbon dioxide into the environment. Climate change is a major global issue, and stopping the acceleration of CO2 and other greenhouse gases has become pivotal for future generations. Carbon dioxide concentrations in the atmosphere reached a record high – 400 parts per million in 2012-2013 – since scientific measurements of the air began. And July 2014 to June 2015 was the warmest year on record, according to the US National Oceanic and Atmospheric Administration.
The science behind making fuel from CO2 isn’t particularly complicated – split water into hydrogen and oxygen via electrolysis, add the hydrogen to CO2 to create carbon monoxide and water, then add in more hydrogen to fortify hydrocarbon chains. This last part is called the Fischer-Tropsch process, and was invented back in the 1920s.
But it’s the technologies sucking in the carbon dioxide from the atmosphere that are just now becoming cheap enough to be feasible. The biggest technological obstacles have been high-temperature furnaces, states Adrian Corless, chief executive of Carbon Engineering.
Corless says there is still “a month of hard work” in order to get the furnaces to work as the company would like. But the furnaces have also have been his firm’s preeminent innovation. Precipitating captured CO2 into solid calcium carbonate pellets which can be easily washed and dried is a major challenge, according to Corless. The pellets are then heated to 800-900ºC, whereon they emit a pure carbon dioxide stream. As a residue, they leave calcium oxide which, can be put back into the first air capture stage.
Captured CO2 isn’t just for fuel; the possibilities are endless. Climeworks, a corporation spun from a local university in Switzerland, is preparing for its inaugural commercial-scale plant that will capture CO2 to a nearby greenhouse. The Swiss company plants on selling fizzy drinks to bottlers in Africa, Japan and faraway islands, by setting up shop locally and saving on transportation expenses. The cost of compressing, liquefying, and shipping carbon dioxide is up to 10 times more expensive in such places, states the firm’s chief operating officer, Dominique Kronenberg. It is definitely easier to extract carbon dioxide from the exhaust of fossil fuel-burning plants that capture it from thin air due to exhaust streams from gas and coal plants containing three percent and 15 percent carbon dioxide proportionately. By comparison, air contains about 400 parts per million of carbon dioxide.
So then what’s the point? “We don’t have to purify exhaust gases from a boiler or coal—these have a lot of sulphur and other molecules that might be difficult to purify out,” Kronenberg told BBC. Another benefit of capturing air is it that it is easier to extract the CO2 using this method than from the exhaust gases of automobiles and other forms of transport, says Corless.
The impending question is whether or not e-diesel could ever compete with fossil fuels on price. Sunfire predicts that their e-diesel will sell for €1-€1.5 ($1.51-$2.27 USD) per liter – making it slightly cheaper than the current UK diesel pump price. Though, it depends heavily on governmental policy. The real price of the fuel could be 30% lower than what the British pay at the pump, while the rest of the price is made up of fuel taxes, VAT, and the retailer’s profit margin.
“So we assume certain taxes might not be applied to these renewable fuels we produce,” said Kronenberg. In the US and the UK there are government proposals to cut greenhouse gas emissions through the implementation of “greener” transport fuels. Nevertheless, it’s the expense of electricity that has the power to make or break e-diesel’s commercial growth, because the method uses an ample amount of energy.
”You can take electricity and convert it to fuel for your vehicle with about 13% efficiency,” explains Dr Paul Fennell, reader in clean energy at Imperial College London. “If you compare that to taking electricity and charging up an electric vehicle, then that can be done with about 80 percent efficiency,” he adds.
But Corless states that “in the last two or three years, the cost of renewable electricity has dropped dramatically—especially solar.”
Would you buy gas made from thin air?