Sci-tech

Scientists say cost of sucking carbon from thin air could tumble

Scientists say cost of sucking carbon from thin air could tumble

"This isn't going to save the world from the impacts of climate change, but it's going to be a big step on the path to a low-carbon economy", said David Keith, a Harvard Professor of Applied Physics and founder of Carbon Engineering.

"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.

Plans to build solar shields in space or to seed the seas with materials to soak up carbon have been seen as risky and a distraction to the more mundane but hard task of getting people to cut their emissions.

"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", David Keith, lead study author and professor from Harvard University, explains in a statement. 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.

"What Carbon Engineering is taking to market is first of all carbon neutral fuels, in that sense we are just another emissions-cutting technology, there is no net removal from the atmosphere", he said.

A British Columbia company says in newly published research that it's doing just that - and for less than one-third the cost of other companies working on the same technology. Its backers hope it will help in the fight against climate change.

The pilot plant in Canada
Carbon Engineering The pilot plant in Canada

Direct air capture technology works through giant fans drawing ambient air into contact with an aqueous solution that picks and traps carbon dioxide. "That's why we think we have a reasonable possibility of scaling up". After running a pilot plant for three years, Canadian company Carbon Engineering (CE) has broken down the costs of a DAC system and shown it can be done much more cost-effectively than previously thought. That means that the fuel could be only USD$1 per liter.

Granted, it's possible that, in practice, the new technology will be more expensive than those estimates predict, especially if it were to be implemented at any major scale.

First, outside air is sucked into the factory's "contactors" and exposed to an alkaline liquid. The projects consists in capturing the Carbon dioxide from the air directly.

Second, the now-watery liquid (containing carbon dioxide) is brought into the factory, where it undergoes a series of chemical reactions to separate the base from the acid. After capturing the Carbon dioxide in solution, the plant transfers it into a solid, which when heated releases it in a pure gas stream.

Direct air capture is pretty much what it sounds like: a large fan draws in lots of air and essentially filters it through a liquid solution which captures any Carbon dioxide it comes in contact with. A Canadian company is entering the race to suck carbon from the sky and turn it into automotive fuels. 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. The carbon is combined with hydrogen to make motor fuel, through a technique used at pulp mills.