Big VC names stake carbon removal startup

Heirloom, a startup developing novel tech for removing CO2 from the atmosphere, raised $53 million in a Series A round that includes boldface names in climate VC.

Driving the news: The Bill Gates-led Breakthrough Energy Ventures co-led the round with Carbon Direct Capital Management and Ahren Innovation Capital.

• Others involved include Microsoft's climate VC arm and Chris Sacca's Lowercarbon Capital.

How it works: Heirloom, founded in 2020, hopes to massively speed up the process by which cheap abundant minerals called carbonates — such as limestone — naturally absorb CO2.

• Their tech heats carbonates to very high temperatures in kilns powered with renewable energy, which breaks it down into CO2 and calcium oxide.
• The CO2 is captured for geologic storage. The calcium oxide is spread out and exposed to the air.
• It then uptakes more CO2 and re-forms carbonates, which are fed back into kilns to separate more CO2 for storage or other uses like building materials. Go deeper.

The big picture: Heirloom is among a suite of young DAC startups.

• Players that are further along, like Climeworks and Carbon Engineering, are also attracting investment and have launched commercial removal contracts with customers.
• But bringing down costs significantly will be key to whether DAC can move the needle on climate.

Why it matters: DAC, if the tech truly scales, could complement renewables, electric cars, efficiency, and other energy tech that slashes new emissions.

• But much faster deployment of zero-carbon energy is needed to prevent blowing past the Paris Agreement goals.