Nonetheless, "We need enormous volumes of CO2 removal and to achieve that, we need accurate economic analysis and hard engineering data", said Julio Friedmann, CEO of Carbon Wrangler LLC and senior advisor at The Global Carbon Capture and Storage Institute.
United Nations reports indicate that governments may have to deploy such novel technologies this century to remove carbon from nature and bury it to limit global warming under the 2015 Paris climate agreement.
"Our low-carbon fuel is entirely compatible with any automobile, any truck, any airplane that exists today", He said.
Carbon Engineering is entering the race to suck carbon from the sky and turn it into automotive fuels.
"The carbon dioxide generated via direct air capture can be combined with sequestration for carbon removal, or it can enable the production of carbon-neutral hydrocarbons, which is a way to take low-priced carbon-free power sources like solar or wind and channel them into fuels that can be used to decarbonize the transportation sector", says lead author David Keith, founder and chief scientist of Carbon Engineering, a Canadian CO2-capture and clean fuels enterprise, and a professor of applied physics and public policy at Harvard University.
"If these aren't renewable fuels, what are?" said David Keith, professor of applied physics at Harvard University, lead author of the paper and principal in Carbon Engineering.
The British Columbia-based company has been working to bring down costs.
The company has also built a pilot operation to turn captured Carbon dioxide into a variety of liquid fuels, including gasoline, diesel, and jet fuel.
It costs Climeworks about $600 USA a tonne to remove carbon from the atmosphere.
President Donald Trump considers pardon for Muhammad Ali
Last week, the president said he was considering pardoning Martha Stewart and commuting the sentence of former Illinois Gov. I'm thinking about that seriously. "There is no conviction from which a pardon is needed", he said.
Carbon Engineering has published a peer-reviewed study showing that they can capture carbon for under $100 dollars a tonne.
"We're tapping into existing industrial equipment and then defining a new process and applying some unique chemistry to it", said Oldham. "Direct air capture" that removes the gas from ambient air has possible since the 1940s, but - at a cost estimated in 2011 to be as much as $1,000 per metric ton of Carbon dioxide - it has always been viewed as too expensive to be practical.
"Until you really can confirm the costs and performance at scale, you've always got to take those costs with a grain of salt", he says.
"We've bought the smallest scalable unit of each piece of technology we have". Prof Keith said that if their fuel gets the same subsidies as other carbon neutral approaches then they will be able to raise funds and build plants very quickly. Oldham said work is being done to reduce that.
Keith co-founded Carbon Engineering in 2009, when direct air capture was still on the fringes of industrial climate solutions.
He compared the idea of recycling atmospheric carbon into fuel to the idea of converting all the cars in the world, estimated at more than 1 billion, to electric and fueling them with electricity from renewable sources, which he said would be incredibly costly and disruptive.
That footprint would shrink further if the plant were all-electric. In the fuel cases, the carbon is essentially recycled and replaces fossil fuels pulled from the ground, hence the process is carbon neutral. "By making the fuel carbon neutral, the entire transportation sector can become carbon neutral without changing all of the infrastructure - we don't all have to get a new vehicle, we don't have to replace every gas station with an electric grid for charging".
Keith is also founder and chief scientist of Carbon Engineering, a Canadian firm that has been developing the technology. Doing that on a large scale would nearly surely require significant cost reductions, a high price on carbon, or other public policy support.