Published: Sun, June 10, 2018
Research | By Raquel Erickson

Key 'Step Forward' In Cutting Cost Of Removing CO2 From Air

Key 'Step Forward' In Cutting Cost Of Removing CO2 From Air

Carbon Engineering says the technique unveiled today has already been implemented at its small, pilot plant in Squamish, British Columbia.

Is that gasoline in the making pouring out of those smokestacks? They are using direct air capture.

He and his colleagues estimate that their company, Carbon Engineering, could capture CO2 for between $94 and $232 per metric ton.

Finally, the carbon dioxide is combined with hydrogen and converted into liquid fuels, including gasoline, diesel, and jet fuel. Plants naturally remove Carbon dioxide from the air, and the proposed machine would mimic their natural actions. Doing that on a large scale would nearly surely require significant cost reductions, a high price on carbon, or other public policy support.

To date, atmospheric carbon capture has been deemed too expensive to be practical, because of the high energy inputs.

The paper's primary researcher was David Keith, Founder of CE.

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

In addition to funds raised by Carbon Engineering, this work was supported by the British Columbia Innovative Clean Energy Fund, Sustainable Development Technologies Canada, the Industrial Research Assistanceship Program, and the U.S. Department of Energy. CE has a pilot plant in Squamish, British Columbia, which has been removing Carbon dioxide from the atmosphere since 2015. So if new fuels are going to actually become widespread, the government may need to provide some subsidies to drop the cost.

What if we could directly capture Carbon dioxide from the atmosphere and turn that into fuel? The liquid goes through a series of steps that include freezing it into pellets and then transforming it into a slurry.

The process uses a liquid sorbent to collect the CO2, unlike others that have used a solid sorbent.

The Swiss company Climeworks has a 900 ton of Carbon dioxide per year commercial facility that has been operating since 2017.

The Carbon Engineering facility is far smaller than the Climeworks operations, now removing just one metric ton, or 2,200 pounds, of CO2 from the atmosphere each day. Producing new fuel at the end provides a way to pay for the effort. "We're ready to build a much larger plant".

The plant draws in air, Carbon dioxide being scrubbed out and eventually combined with hydrogen to form a variety of different liquid fuels. The company is now making around one barrel a day by combining the pure Carbon dioxide with hydrogen derived from water, using renewable energy. And with oil prices surging in recent months, it might not have to worry about being able to compete with traditional sources.

The study implies that falling costs of solar power could produce hydrogen affordably from electrolysis without producing an excessive increase in CO2. If that problem is not addressed, experts stress, the price tag could run into the trillions of dollars in terms of flooding, as oceans rise and the weather grows more volatile, losses in food production and other problems.

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.

What makes DAC so useful is that it's completely scaleable - so rather than having to develop new technologies to make it bigger, you simply build lots of them.

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