On May 31, the Swiss company Climeworks will turn on the first commercial plant to suck carbon dioxide out of the air and feed it to vegetables in a neighboring greenhouse. Located in the tiny, agricultural municipality of Hinwil, Switzerland, the plant stands 40 feet tall and looks like a rectangular wall of oversized dryers stacked three-high.
It will be the first business to sell carbon dioxide drawn right out of its surroundings, using a technology called direct air capture. To date, carbon capture technologies have been restricted to areas where there are high concentrations — like the smokestacks of coal-fired plants. But the promise of direct air capture is to grab the kind of ambient carbon emitted by cars, aircraft, and trains.
Since it’s not happening at the source, direct air capture must be able to deal with lower concentrations (0.04 percent of air), making the technology inherently more difficult, and expensive. That’s why until now, it has been demonstrated only in small, experimental pilot plants.
What Climeworks is hoping to show in Hinwil isn’t just that the technology works but that captured carbon can then be resold as plant fertilizer, fuel, or even for carbonated beverages.
How this could help the environment
But climate scientists say so-called negative-emissions technologies — which remove pollutants from air — will be crucial to meet the goal of the Paris Agreement, the landmark 2015 deal co-signed by 196 nations, to hold the increase in global temperature to no more than 2 degrees Celsius.
“Climeworks is the first to scale up to substantive level,” said Julio Friedmann, a former principal deputy assistant for fossil energy for the U.S. Department of Energy and senior adviser at the Lawrence Livermore National Lab. “There’s almost no way to hit those targets without using negative emissions, and in some cases, quite soon.”
The plant is projected to capture 900 metric tons of the greenhouse gas, or about the emissions from 200 cars a year. It traps ambient carbon dioxide with absorbent filters inside the plant’s air collector. To release the carbon dioxide, the filters are heated to 212 °F with waste heat from a neighboring partner waste incinerator plant owned by the company Kezo. The freed carbon dioxide is then pumped over to the greenhouse operated by Gebrüder Meier to “enhance the growth of vegetables and lettuce by up to 20 percent,” according to a press release.
One study estimates that to avoid the two-degree global temperature rise by century’s end, negative emission technologies must scale up to capturing 5 billion tons of CO2 annually by 2050. That’s approximately twice the amount absorbed by all the planet’s oceans. And it’s a hefty ask for these fledgling technologies.
“If we want to do this by midcentury, we need to not only start developing these technologies but implementing and scaling up these technologies. That’s what we see as our main role,” said Jan Wurzbacher, who co-founded Climeworks in 2009 with Christoph Gebald at the University ETH Zurich. Wurzbacher and Gebald developed their process in collaboration with the Swiss Federal Laboratories for Materials Science and Technology; the startup has received more than $7 million in venture capital funding from Venture Kick, Gebert Ruf Stiftung, de Vigier Stiftung and ClimateKIC, private investors, and also grants from the Swiss government for various projects, including their new plant.
The company has an ambitious goal of capturing 1 percent of the global emissions of CO2 by 2025. That would require 750,000 of their modular plants in operation, Wurzbacher said. To get there, they need to cut costs by a quarter to a third and land a lot more customers, he said.