Imagine filling your car with gas pulled from the sky, rather than out of the ground.
Scientists have developed a cost-effective way of pulling CO2 from the air and creating carbon-neutral fuels, including petrol and diesel, compatible with existing fuel networks and vehicles.
The process works by direct air capture – which is when giant fans draw ambient air into contact with an aqueous solution that picks out and traps carbon dioxide.
Add heat and chemical reactions, and that same carbon dioxide can be re-extracted and made into new fuels, to be used or stored, they say.
How to suck carbon dioxide from the sky for fuels:
Someday, the petrol you buy might trace its heritage to carbon dioxide pulled straight out of the sky rather than from oil pumped out of the ground. By removing emitted carbon dioxide from the atmosphere and turning it into fresh fuels, engineers at a Canadian firm have demonstrated a scalable and cost-effective way to make deep cuts in the carbon footprint of transportation with minimal disruption to existing vehicles.
“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-cost 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.
The idea of direct air capture is hardly new, but the successful implementation of a scalable and cost-effective working pilot plant is. After conducting a full process analysis, Keith and his colleagues claim that realising direct air capture on an impactful scale will cost roughly $94-$232 per ton of carbon dioxide captured.
That price-point is low enough to use direct air capture to start tackling the roughly 20% of global carbon emissions that result from driving, flying, trucking, and other ways of getting people and goods around. “Electricity from solar and wind is intermittent; we can take this energy straight from big solar or wind installations at great sites where it’s cheap and apply it to reclaim and recycle carbon dioxide into new fuel,” Keith says, adding that “Making fuels that are easy to store and transport eases the challenge of integrating renewables into the energy system.”
The resulting fuels, including petrol and diesel, are compatible with existing fuel distribution and transportation infrastructure. Thanks to ultra-low life cycle carbon intensities, they are a promising route for reducing carbon emissions in heavy transportation and other sectors of the energy system that are demanding and difficult to electrify.
“After 100 person-years of practical engineering and cost analysis, we can confidently say that while air capture is not some magical cheap solution, it is a viable and buildable technology for producing carbon-neutral fuels in the immediate future and for removing carbon in the long run,” says Keith.
This story was first published in The Fence magazine.