Claire Nelson

Direct air capture technology has made it possible to remove carbon dioxide from the sky. But then what? Claire Nelson, 31, cofounder of Cella Mineral Storage, aims to inject that carbon dioxide underground and securely store it as a mineral called carbonate. 

Carbon mineralization naturally occurs when carbon dioxide, water, and porous volcanic rock meet. Cella tweaks this process by repeatedly injecting CO₂, followed by water, into bedrock. This allows the company to more evenly distribute CO₂ within the rock’s pores and use half as much water as other similar carbon storage methods. Using fewer resources lowers the cost, and a more even distribution of carbonate makes it less likely the rock’s pores will clog up. Plus, injection sites don’t need to be monitored as heavily, because there’s little risk of the carbon dioxide escaping. 

Nelson, who received her PhD in geochemistry from Northwestern University, is also working to accurately capture where mineralized carbon is stored underground. She’s filed a patent for a technique that  will analyze the levels of carbon and calcium in the water contained within a reservoir at different stages of the mineralization process. With this technique, the company can determine where exactly in the reservoir the carbon is being stored. 

Cella, which is based in New York City and employs seven people, is now constructing its first commercial carbon storage facility, in Kenya, alongside a direct air capture plant built by RepAir. They will need to show that the stored carbonate does not clog the reservoir’s pores and reduce the rock’s permeability (which could be  detrimental). Then, Nelson hopes to expand to more countries and plans to focus her efforts on those that will struggle the most to transition from fossil fuels to renewable energy.