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 Dollars 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 unit would be one of several that would collectively capture 1M tons of Carbon dioxide per year.
Prof Keith's "useful way" is not to simply suck carbon out of the air but to use the extracted gas as a key raw material for synthetic liquid fuel. Carbon Engineering proudly says that cutting the costs to such an extent is a "real step forward". It started converting carbon dioxide into fuels previous year.
Until now, the cost of climate change has been all about projections. By removing emitted carbon dioxide from the atmosphere and turning it into fresh fuels, engineers at a Canadian firm have demonstrated a scalable and cost-effective way to make deep cuts in the carbon footprint of transportation with minimal disruption to existing vehicles. Numerous so-called negative emissions technologies exist, including growing perennial plants and trees to make biofuels, and sequestering carbon in soils.
Carbon Engineering's plant in Squamish, B.C., now pulls about one tonne of carbon a day from the air and produces about two barrels of fuel.
She has been involved in a project in Iceland where Carbon dioxide from direct air capture is being turned into rock, deep underground.
Set up in 2009 with funding from Microsoft's Bill Gates and Canada oil sands financier Norman Murray Edwards, their pilot plant has been running since 2015, capturing about one tonne of Carbon dioxide per day. The calcium carbonate pellet can be heated to release the CO2.
In 2011, a pair of influential papers all but sounded the death knell for direct air capture, concluding that the approach would cost almost an order of magnitude more than capturing the greenhouse gas from power-plant stacks. Each day they absorb about a ton of Carbon dioxide, but they're working on blueprints for a much larger facility which could potentially filter a million tons of Carbon dioxide per year.
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.
The company has also built a pilot operation to turn captured Carbon dioxide into a variety of liquid fuels, including gasoline, diesel, and jet fuel.
The National Renewable Energy Laboratory (NREL) reported in 2016 that electrolysis using wind power could provide hydrogen at a cost of about $4.50 per kilogram. The result is a compound that can be converted whatever liquid fuel is chosen using the same Fischer-Tropsch processes as a conventional refinery.
"Although direct air capture cost of around $100 per tonne is still somewhat steep, in our current situation where sticks and carrots for similar technologies are sorely lacking, the cost can only be brought down through further development and streamlining of individual technologies and conjugated processes", Edda Sif Aradóttir, from Reykjavik Energy told BBC News.
That's more expensive than most fuels today, but not by much. But, what if we say there is a way to reverse the process by capturing the gas straight out of the sky and converting it into low carbon fuel? Since its components are off the rack, it should be easy to scale up, Oldham said.