Canada’s Carbon Engineering claims CO2 could be sequestered from the air for less than $100 a ton and converted into carbon-neutral fuel for existing vehicles.
(Credit: Carbon Engineering)
In a new paper published in Joule, the company describes the results from a pilot plant it has been operating in British Columbia since 2015. The plant has been capturing 1 t-CO2/day using giant fans to draw air through an aqueous solution of potassium hydroxide (KOH) coupled to a calcium caustic recovery loop. Working with an independent engineering consultancy, Carbon Engineering has extrapolated the cost of building the process out to scale and integrating it with renewable energy. According to the firm, the cost should be roughly $94-$232 per ton of carbon dioxide captured.
What’s more, the company has developed a process to transform the captured CO2 into hydrocarbon fuels such as petrol, diesel and jet fuel. The facility in British Columbia is already achieving CO2 capture and fuel generation
“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 decarbonise the transportation sector,” said lead author David Keith, founder and chief scientist of Carbon Engineering and a professor of applied physics and public policy at Harvard University.
“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.”
Rendering of Carbon Engineering’s proposed air contactor design (Credit: Carbon Engineering)
As the resulting fuels are compatible with existing distribution and transportation infrastructure, the company believes they are a promising route for reducing carbon emissions in heavy transportation and other sectors of the energy system that are difficult to electrify. Using standard industrial equipment, Carbon Engineering said it could build full-size plants capable of manufacturing 2,000 barrels of fuels per day.
“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,” said Keith.