Heirloom Carbon
Heirloom Carbon is a Direct Air Capture company founded in 2020 and based in Brisbane, United States. It has raised $203M in total funding, most recently a Series B in 2024.
Founded in 2020 and based in Brisbane, California, Heirloom Carbon runs a limestone-looping form of direct air capture that speeds the natural weathering of crushed limestone so it reabsorbs atmospheric CO2 in days rather than years. It operates North America's first commercial DAC facility in Tracy, California, and is a partner on Project Cypress, a U.S. Department of Energy-backed regional DAC hub in Louisiana. The company has raised over $200 million, including a $150 million Series B, with carbon-removal offtakes from buyers including Microsoft, Stripe, Shopify, and United Airlines.
A leading low-thermal DAC approach using cheap, abundant limestone, anchoring one of the U.S. DOE's flagship regional direct-air-capture hubs.
heirloomcarbon.com ↗·Direct Air Capture·
United States·private 
