Heirloom Carbon

Market position

Heirloom describes itself as America's leading direct air capture company and is credited with opening the first commercial DAC facility in the United States; it is one of the more heavily capitalized DAC developers, with a $150M Series B backed by strategic industrial and airline investors and participation in a DOE-funded DAC hub.

Unlike DAC designs that rely on liquid solvents or highly engineered sorbents, Heirloom uses inexpensive, widely available limestone-derived lime as its sorbent and a passive air contactor rather than energy-intensive fan walls, which the company positions as a route to one of the lowest-cost forms of permanent carbon removal. Heirloom has stated a long-term path to $50 per ton of CO2 removed and estimates industry-wide prices falling to $200-$300 per ton by the early 2030s from a current $600-$1,000 range.

Technology

Heirloom's approach is a solid-sorbent DAC process based on accelerated carbon mineralization. Carbonate minerals are used as the sorbent because they are abundant and cost less than 1% of highly engineered sorbents; proprietary techniques enhance the mineral's natural CO2 uptake rate, reducing a geological-timescale process to days and allowing passive exposure of the sorbent to ambient air rather than large fan arrays. A highly optimized passive air contactor plus automated materials handling moves the sorbent through capture and regeneration, where heating releases pure CO2 for permanent geologic storage. The company cites US Geological Survey estimates of roughly 3,000 gigatons of CO2 storage capacity in US reservoirs deeper than 3,000 feet, and notes the technology can be sited anywhere with geologic storage and low-cost renewable power.

Go-to-market

Direct enterprise sales of carbon removal offtake agreements to large corporate buyers and advanced market commitments such as Frontier, complemented by an online purchase channel for carbon removals, government-supported project development (Project Cypress), and strategic investment relationships with industrial and transport corporates.

Corporates buying permanent, verifiable carbon dioxide removal, including technology, financial services and consumer companies, plus hard-to-decarbonize industrials such as aviation and shipping; named buyers include Microsoft, Stripe/Frontier, Meta, Shopify and JPMorgan.

Geography

United States: headquarters in California (reported in Brisbane, California, and described as San Francisco-based), a commercial DAC facility in Tracy in California's Central Valley, and two facilities under construction in northwestern Louisiana. Investors include Japanese corporates such as Japan Airlines, Mitsubishi Corporation (Americas), Mitsui & Co. and MOL Switch.

History

Heirloom publicly launched in April 2021, announcing a plan to harness and accelerate carbon mineralization for low-cost direct air capture, with a stated goal of permanently removing billions of tons of CO2 by 2035. The capture approach was co-invented with researchers in direct air capture and carbon mineralization, credited to Peter Kelemen, Jennifer Wilcox, Greg Dipple, Phil Renforth, Wade McGillis and Heirloom's Noah McQueen. The company started operating North America's first commercial DAC plant in Tracy, California in late 2023, secured $475 million for a second North American DAC facility in Louisiana, announced two Louisiana plants in June 2024, and closed a $150 million Series B in December 2024.

Risks & controversies

Carbon removal costs remain far above the roughly $100 per ton level that experts describe as necessary for wide deployment; Heirloom's own estimates put current removal costs at $600-$1,000 per ton and only project $200-$300 per ton by the early 2030s, with profitability contingent on reaching those prices. Scaling depends on continued corporate credit demand and government funding, and airline investment in DAC has drawn debate over whether offsetting fossil jet fuel emissions substitutes for cleaner fuels.