CO₂ from the air with battery chemistry: method needs about half as much energy
A University of Delaware team captures CO₂ with a battery electrode at room temperature. A pilot unit in Israel ran for more than 5,000 hours, the university says.
Graphic: TERRA WORLD NEWS (own graphic based on the sources listed)
Systems that pull carbon dioxide directly from the ambient air (direct air capture) are seen as one way to offset hard-to-avoid emissions – but so far they need a lot of energy. A team led by chemical engineer Yushan Yan, Henry Belin du Pont Chair at the University of Delaware, uses the chemistry of rechargeable batteries instead. The study has been published in the journal Nature Energy; the university presented it on 27 October.
A nickel hydroxide electrode takes up CO₂ from the air on one side of the device and releases it as a purified gas stream on the other – driven by electricity rather than heat, at room temperature. When one electrode is discharged, a second takes over while the first is recharged, so the process runs continuously. According to the researchers, the method needs less than one megawatt-hour per ton of CO₂, about 50 percent less energy than conventional systems.
The company RepAir Carbon, one of the technology's licensees, ran a pilot unit in Israel for more than half a year, over 5,000 hours. Researchers widely regard 100 dollars per ton as the target for affordable capture. "This technology brings those numbers within reach," says first author James Buchen. The captured CO₂ can be stored or reused, for example in the beverage industry; the announcement gives no specific costs for the unit.