CO2 pumped out of tailpipes in New York City traffic could eventually be sucked up by an air capture plant in the desert in Australia or North Africa.
Carbon Engineering, a Canadian startup, is designing massive walls of fans that suck carbon dioxide out of the air and turn it into things we need–like more fuel.
Because carbon dioxide is everywhere, the air capture plants could be built anywhere in the world and still help reduce global concentrations. “A direct air capture plant can be built wherever land is cheap and there is a demand for the CO2 produced,” says Geoff Holmes, Carbon Engineering’s business development manager.
While trees naturally do the same thing as the company’s machines, planting enough trees to deal with the world’s carbon problems would take at least 1,000 times more land–and the trees would have to live in areas that might be needed for agriculture. The smog-sucking machines are more efficient and can go in deserts.
The technology works by pulling air over a special carbon-absorbing liquid that traps CO2 and turns it into a salt. While it’s not quite as easy as trapping carbon directly at a source like the smokestack on a coal power plant–where concentrations are far higher–it’s possible (though less efficient). And it’s important, because most emissions come from moving sources like cars.
“Only about 40% of our total emissions come from large flue stacks, and the other 60% results from what we call ‘diffuse and mobile’ sources that can be difficult to tackle at source,” says Holmes. “Capturing them back from the atmosphere may be a key way to help manage these diffuse emissions.”
The captured CO2 can be stored underground, used in the oil industry to make something called “low carbon crude,” or turned into low-carbon synthetic fuels that can replace something like jet fuel.
“These fuels have the same chemical make-up as fossil fuels, but are sourced from air and sunlight rather than from crude oil,” says Holmes. “Air capture plus fuel synthesis is potentially one of the few truly scalable ways to power transportation in a way that’s carbon-neutral.”
At its pilot plant in Canada, Carbon Engineering is getting ready to run their machine continuously for the first time, and we’ll see if this seemingly crazy idea will actually work. “This will prove that CE’s carbon capture technology is now ready to build and operate at a large industrial scale,” he says. After the pilot finishes, the company plans to build a first-of-its-kind commercial plant in 2017 or 2018. The plant will produce 10,000 barrels of synthetic fuel in a year.
It’s the kind of engineering that could be necessary if the world is going to attempt to avoid catastrophic climate change; even if humans somehow instantly stopped using fossil fuels now, we’d be unlikely to stay under the two-degree limit for global warming that climate scientists say is needed.
But it’s also not the only answer. “No one single technology or approach is ‘enough’ to help avoid climate change; we need every option we’ve got, and more,” says Holmes. “Air capture has the potential to be a big help in cutting emissions that are difficult and costly to reduce at source, and that will add to the momentum that’s building in other sectors of the clean-tech industry. The moment you start cutting emissions is the moment you start reducing risk of future dangerous climate change.”