seawater
(2)
Calcarea
Calcarea is a Caltech- and USC-born climate-tech company decarbonizing the shipping industry with onboard reactors that capture CO2 from ship exhaust and convert it into stable ocean bicarbonate. By speeding up the natural reaction between seawater and limestone - a process that normally takes over 10,000 years - down to about a minute, Calcarea aims to permanently and safely store roughly half of a cargo ship's emissions as slightly saltier seawater, at costs competitive with today's best carbon capture options.
Magrathea
Magrathea is an Oakland, California clean-tech company rebuilding American magnesium production. Using a next-generation electrolytic process, it makes magnesium metal from seawater and brines with near-zero carbon emissions, aiming to break the West's dependence on Chinese supply for a metal critical to aerospace, automotive, and defense.