Molecules called photoacids could offer a more energy-efficient way to release carbon dioxide captured from the air in order to store or reuse it
This direct air capture system can pull carbon dioxide from the air for later reuse – but it requires a lot of energy Orjan Ellingvag / Alamy Light-sensitive molecules called photoacids could make the process of removing carbon dioxide from the atmosphere more energy efficient. Researchers are now devising ways to make photoacids more practical to use. This could be especially valuable for direct air capture (DAC) systems, which blow air over carbon-capturing materials called sorbents. Existing systems require a large amount of energy to separate pure CO2 from sorbents in order to store or use it elsewhere. This poses a major barrier to using DAC to remove billions of tonnes of CO2 from the atmosphere each year. "That step is hitting a wall," says Anna de Vries at ETH Zurich in Switzerland. "Every single direct air capture company is struggling and trying to make the most efficient process." Advertisement Adding photoacids to the sorbents could help. When illuminated, each photoacid molecule changes…