Harvard researchers have found a cost-effective way to remove emitted carbon dioxide from the atmosphere, and turn it into fuel.
Direct air capture technology works through giant fans drawing ambient air into contact with an aqueous solution that picks and traps carbon dioxide.
Through heating and a handful of familiar chemical reactions, that carbon dioxide is re-extracted and can be used as a carbon source for making valuable chemicals like fuels or for storage via a sequestration strategy.
Scientists from Harvard University in the US and Carbon Engineering, a Canadian CO2-capture and clean fuels enterprise, is already achieving both CO2 capture and fuel generation.
The technology will soon be able to produce gasoline and jet fuel from little more than limestone, hydrogen, and air, researchers said.
It aims at the eventual construction of a vast, industrial-scale network of carbon scrubbers, capable of removing greenhouse gases directly from the atmosphere.
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"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," said David Keith, a professor at Harvard University.
"Making fuels that are easy to store and transport eases the challenge of integrating renewable into the energy system," said Keith.
The resulting fuels, including gasoline, diesel, and jet fuel, are compatible with existing fuel distribution and transportation infrastructure.
Due 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.
The successful implementation of a scalable and cost-effective working pilot plant is a new revelation.
After conducting a full process analysis and crunching the numbers, Keith and his colleagues claim that realising direct air capture on an impactful scale will cost roughly USD 94-232 per tonne of carbon dioxide captured, which is on the low end of estimates that have ranged up to USD 1,000 per tonne in theoretical analyses.
This price point is low enough to use direct air capture to start tackling the roughly 20 per cent of global carbon emissions that result from driving, flying, trucking, and other transportation.
Due to unchecked human carbon emissions, atmospheric carbon dioxide is a virtually unlimited feedstock for transformation into new fuels.
The project has the capability to move to full-size plants capable of manufacturing 2,000 barrels of fuels per day totalling over 30 million gallons per year across plants.
Commercialisation of such plants would allow direct air capture to affect transportation emissions by connecting low-cost renewable energy to low-carbon transportation fuels.