Key 'step forward' in cutting cost of removing Carbon dioxide from air

Mindy Sparks
June 8, 2018

Carbon Engineering acknowledges that their work isn't going to end global warming, but they say it could help bridge the gap between today's economy and its reliance on fossil fuel and a future economy powered by sustainable energies.

"The goal of capturing from the air is that you can make low carbon fuels from renewable power". At that point, one of the only ways to reverse the effects is to remove carbon dioxide from the atmosphere, where it otherwise persists for thousands of years.

The study appeared in a new scientific journal Joule, and covered in the June issue of The Atlantic.

"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.

"It's unlike Carbon dioxide capture that's created to work from a power plant". Giant fans draw ambient air into contact with an aqueous solution that picks out and traps carbon dioxide. After heating and chemical reactions, the carbon dioxide can be extracted - and used either for making fuel or for storage. Once purified, the captured Carbon dioxide can be injected underground or used to make commercial products, such as fuels or plastics.

The idea of direct air capture is hardly new, but the successful implementation of a scalable and cost-effective working pilot plant is.

David Keith, a Harvard physics professor and lead author of the paper, says the findings should shift the perception of direct air capture from "vaporware" to "something that can be built with current industrial technologies now". That gives it a carbon footprint 70 per cent lower than a fossil fuel, he said.


Long-distance transportation would welcome such fuel, suggested Keith. 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 hard to electrify.

Keith says it is still cheaper to cut emissions of carbon dioxide than to remediate them. "These guys actually have something you can measure", says Stephen Pacala, an ecologist with Princeton University who is chairing a panel on carbon removal technologies for the National Academies of Sciences, Engineering, and Medicine. To make real gains in removing greenhouse gases, the world may eventually need to permanently store massive amounts of captured carbon dioxide, rather than releasing it again when synthetic fuels burn.

Keith and Oldham are optimistic that they have reduced scale-up risks by implementing direct air capture at reasonable costs using standard industrial equipment.

"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. Commercialization of such plants would allow direct air capture to make a dent in transportation emissions by connecting low-cost renewable energy to low-carbon transportation fuels using Carbon Engineering's AIR TO FUELSTM pathway.

A Canadian company, backed by Bill Gates, says it has reached an important threshold in developing technology that can remove Carbon dioxide from the air.

Keith is also the founder of Carbon Engineering, a Calgary-based startup that has spent the last nine years designing, refining, and testing a direct air capture pilot plant in Squamish, British Columbia.

Other reports by Iphone Fresh

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