A new carbon removal startup is powered by sunlight and seawater
economictimes.indiatimes.comcarbon capture approaches. The technology? Sunlight and seawater.
The company, Banyu Carbon, says it has developed an ocean carbon dioxide removal (CDR) system that relies on a synthetic molecule that, when exposed to light, changes shape and becomes acidic. When it interacts with seawater, the resulting process scrubs CO2. Though the company is currently working at the gram scale, its technology holds the promise of a low-cost way to limit global warming.
“The main problem we're trying to solve is that carbon removal takes a ton of energy,” says Banyu co-founder and Chief Executive Officer Alex Gagnon, a chemical oceanography professor who spun the startup out of the University of Washington in 2022 with colleague Julian Sachs. (A marine organic chemist and Banyu’s chief technology officer, Sachs previously conducted fieldwork in the Pacific, and “Banyu” is an Indonesian word for “seawater.”)
The startup’s workhorse is a unique molecule, dubbed a “reversible photoacid.” After being exposed to sunlight, the photoacid releases acidifying protons that are temporarily transferred to seawater pumped into a tank, where it transforms dissolved CO2 in the water into a gas that can be safely stored. The decarbonised seawater is returned to the ocean where it draws down CO2 from the atmosphere. Once back in the dark, the photoacid resumes its original shape for reuse.
Since blue-spectrum light waves are the catalyst for the process, Banyu mostly uses power to operate seawater pumps. That’s in contrast to many other ocean
