美国国家公共电台 NPR How One Company Pulls Carbon From The Air, Aiming To Avert A Climate Catastrophe（在线收听）

STEVE INSKEEP, HOST:

At a climate meeting in Poland this week, almost 200 countries are trying to reach a deal - a deal to dramatically reduce carbon emissions. A recent U.N. report finds that may not be enough to avoid the most dangerous climate effects. It says what's really needed is a way to actually pull massive amounts of carbon dioxide from the air. NPR's Jeff Brady traveled to Canada to see how one company aims to do that.

JEFF BRADY, BYLINE: North of Vancouver in the picturesque small town of Squamish, we're at an industrial site to see what's behind a locked chain link fence.

(SOUNDBITE OF CHAIN CLANGING)

BRADY: It's raining, so the grounds of a company called Carbon Engineering are muddy. Our guide is chemist and engineer Jenny McCahill.

JENNY MCCAHILL: So we're walking up now towards our air contactor.

BRADY: This is the machine that sucks carbon dioxide out of the air. It looks like an oversized semitrailer with a huge fan on top. In front, it sounds like a waterfall.

(SOUNDBITE OF LIQUID RUNNING)

BRADY: The liquid has chemicals that capture and retain carbon dioxide. That may sound simple, but even though scientists say there's too much CO2 in the atmosphere now, it's still a tiny fraction - about .04 percent.

MCCAHILL: So you have to pull in a huge volume of air to get that CO2. And that's really the trick to direct air capture.

BRADY: Next, more chemicals are added. The liquid is heated and turned into white pellets that are 50 percent carbon dioxide. McCahill is holding some in her hand.

MCCAHILL: As you can see, those pellets are about a millimeter in diameter.

BRADY: They look like the things inside of a bean bag chair.

MCCAHILL: Yep.

BRADY: The pellets are superheated to further concentrate the CO2 into a gas. At this point, the company could inject that underground. That's one way to address climate change. But there's no business model for that right now, and Carbon Engineering is looking for profits. So it combines the CO2 gas with hydrogen extracted from water and makes a synthetic fuel. McCahill has a glass bottle of the clear liquid and says it's similar to crude oil.

MCCAHILL: It's a lot purer. So we don't have impurities like sulfur and nitrogen components that end up with that soot when you combust.

BRADY: Can I smell it?

MCCAHILL: Sure.

BRADY: So you're taking the cap off. And it sort of smells like an alcohol, maybe.

MCCAHILL: A little bit, yeah. That's kind of just the smell of the hydrocarbons.

BRADY: Put this liquid through a refinery, and McCahill says you could burn it in your car. But that emits carbon dioxide. So, essentially, the company would just be moving carbon around, not reducing it. Still, CEO Steve Oldham argues there is an environmental benefit.

STEVE OLDHAM: We capture it again the next day. And we make more fuel out of it. So the CO2 becomes recycled. And consequently, there's no additional emissions from using the fuel.

BRADY: That's because Carbon Engineering's fuel would replace carbon-intensive fossil fuels.

OLDHAM: If you were to sell our fuel directly at the pump today, we're about 20 percent more expensive than regular gasoline.

BRADY: But you can't buy the fuel now. This is a pilot plant that removes just one ton of CO2 from the air each day and produces only about two barrels of synthetic fuel. Oldham says his company, along with investors that include Bill Gates, spent $30 million in nearly a decade perfecting this process. He says they're ready to build much larger plants now. The company says it can extract carbon dioxide from the air for less than $100 a ton. But some experts are skeptical it can be done that cheaply. Howard Herzog is senior research engineer at the Massachusetts Institute of Technology Energy Initiative.

HOWARD HERZOG: The reality is it's a lot cheaper to keep CO2 out of the air than to capture it once we get it into the air.

BRADY: But many of his colleagues argue it's too late to rely on only reducing emissions with projections of dire consequences from climate change. Jennifer Wilcox is a chemical engineering professor at Worcester Polytechnic Institute.

JENNIFER WILCOX: Certainly in light of the recent climate report, we don't have the option of simply avoiding carbon emissions anymore. We now are at a point where we need to start removing CO2 directly from the atmosphere.

BRADY: Wilcox and others say the technology needs more research and development.

NOAH DEICH: I see this industry similar to the renewable energy industry maybe 20 or 30 years ago.

BRADY: Noah Deich heads the California group Carbon180 and says direct air capture needs the kind of private and government investment that helped wind and solar grow. Earlier this year, Congress gave the fledgling business a hand, expanding tax credits for extracting carbon.

DEICH: I think an even bigger opportunity on the policy front is in California.

BRADY: Deich says the state has a carbon trading program for transportation fuels like gas. That could be a big boost for Carbon Engineering's fuel. Back at the company's plant in British Columbia, CEO Steve Oldham wants more government programs that put a price or tax on carbon dioxide emissions.

OLDHAM: It will force companies that have a carbon footprint today to find ways to mitigate that carbon footprint. And we're a very good way of doing so.

BRADY: Oldham says his company plans to soon build its first full-sized plant, one that will suck much more carbon dioxide out of the air and, he hopes, become a model for many more plants in the future. Jeff Brady, NPR News, Squamish, British Columbia.

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