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Exclusive: Rewind raises $5M to deposit biomass into the Black Sea

Illustration of an anchor holding three carbon dioxide molecules underwater.

Illustration: Aïda Amer/Axios

Carbon removal startup Rewind has closed a $5 million seed round to collect biomass from farm and timber harvests and deposit it in the Black Sea.

Why it matters: The Israeli company says its model offers a relatively cheap approach to removing carbon from the atmosphere.

Catch up fast: The Black Sea has what's known as an anoxic seabed, meaning there's no oxygen at its lowest depths.

  • That makes the water body a potential repository for plants that might otherwise vent carbon into the air when they decompose or get burned.

How it works: Rivers already carry farm leftovers and other biomass to the Black Sea.

  • Rewind aims to accelerate that process by paying logistics companies to haul that material by truck and ship, and then selling the associated carbon credits.
  • "Not a lot of capex, not a lot of opex to get this done," CEO Ram Amar tells Axios.

Driving the news: Rewind in September closed a $3.75 million seed round that included early-stage investor Yes VC, ocean climate-tech venture fund Propeller, carbon removal marketplace Frontier, and climate accelerator Third Derivative.

  • Mensch VC, Leap Forward Ventures and Zora participated.
  • Adding to the total were $250,000 in research grants from Frontier, and $1 million from the Israeli Government Innovation Fund.

What's next: Rewind plans to sequester about 30 to 40 tons of CO2, with an early focus on wood waste. It hopes to follow that project with a 10,000-ton effort.

Of note: One ton of biomass roughly equates to about 1 ton of carbon sequestration.

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