Frontier buyers sign $47M in offtake agreements with CarbonCapture Inc. and Heirloom

• CarbonCapture and Heirloom will remove a total of 72,000 tons on behalf of Frontier buyers by 2030.
• DAC, when paired with geologic storage, offers high durability, limited physical footprint, and straightforward verifiability making it a promising carbon removal pathway.
• Frontier has facilitated purchases on behalf of Frontier Founding Members Stripe, Alphabet, Shopify, Meta, and McKinsey Sustainability, as well as Autodesk, H&M Group, JPMorgan Chase, and Workday. Aledade, Boom Supersonic, Canva, SKIMS, Wise, and Zendesk have purchased via Watershed’s partnership with Frontier.

Frontier has facilitated its first set of direct air capture (DAC) offtakes with CarbonCapture and Heirloom. Frontier buyers will pay CarbonCapture $20.0M to permanently remove 45,500 tons of CO₂ by 2028 and Heirloom $26.6M to remove 26,900 tons of CO₂ by 2030 from its next commercial facility, with options to purchase more tons from future projects at lower prices. These prices account for both the removal itself as well as measuring, reporting, and verifying (MRV) that each ton is safely stored and accounted for according to a rigorous protocol.

DAC pulls CO₂ out of ambient air via a recurring cycle of CO₂ capture and release that’s facilitated by a sorbent or solvent. The resulting CO₂ stream can then be coupled with geologic sequestration or mineralization for permanent carbon removal.

DAC is one of several promising solutions that could help get carbon removal to gigaton-scale. It is highly durable, easy to measure and verify, and takes up a small physical footprint relative to other kinds of carbon removal. DAC’s main challenge is the high cost per ton, which is driven by both capex as well as the energy required to power the process. Frontier looks for DAC companies that are likely to have particularly steep cost curves and fast iteration speeds (either due to the nature of the technology itself, the team, or both). CarbonCapture and Heirloom are two of those companies—each with a distinct approach.

CarbonCapture’s DAC machines use solid sorbents that soak up atmospheric CO₂ and release concentrated CO₂ when heated. Sorbent choice is a major cost driver for DAC companies, as it impacts both upfront costs as well as how much energy is required in regenerating the sorbent. CarbonCapture has built a modular and upgradeable capture system that allows them to swap in best-in-class sorbents as they become available. In parallel, they’re actively cultivating a pipeline of new sorbents through external partners.

Taken together, this allows CarbonCapture to drive down costs by upgrading the sorbent in existing units, instead of needing to build an entirely new facility to benefit from the latest sorbent breakthroughs. Buyers will pay a price per ton that will decline steadily over the course of the agreement, by at least 46%.

CarbonCapture's modular sorbent cartridge system removes CO₂.

Heirloom takes a different approach. The company’s core innovation is the use of limestone (an inexpensive, abundant, and effective material that absorbs CO₂ naturally) coupled with a modular and repeatable process. In Heirloom’s process, crushed limestone is heated to remove the CO₂ stored in the rock and then spread on stacked trays and hydrated to expose the now highly reactive rock to the ambient air. Over the course of three days (as opposed to the months to years it would take in nature) the minerals absorb CO₂. They’re then moved into an electric kiln and heated for a few seconds, resulting in a stream of CO₂ that can be paired with any type of permanent storage. The same crushed rock is then redistributed back onto the trays, and the cycle begins again.

What makes Heirloom compelling is that their path to low-cost DAC doesn’t depend on breakthrough innovation but rather operational excellence and economies of scale. Heirloom has made substantial progress down their cost curve, reducing their price by more than 50% since 2021, and projects a further 70% decline by 2030.

Heirloom “tray-stack” process to remove CO₂ using limestone.

Frontier founders Stripe, Alphabet, Shopify, Meta, McKinsey Sustainability, and members Autodesk, H&M Group, JPMorgan Chase and Workday purchased as part of this round of offtakes. Aledade, Boom Supersonic, Canva, SKIMS, Wise, and Zendesk will also participate with purchases via Frontier’s partnership with Watershed.

Adrian Corless, CEO, CarbonCapture: “We're extremely pleased to be supplying Frontier and its members with high-quality DAC carbon removal. Large offtake agreements like this are critical to us because they demonstrate commercial viability and unlock a path to scale. We highly value Frontier's confidence in our technology and team, particularly as we emerge from the lab and begin deployment.”

Shashank Samala, Cofounder and CEO, Heirloom: “On the heels of opening America’s first and only commercial Direct Air Capture facility, our team at Heirloom is thrilled to sign offtake agreements with Frontier members to remove CO₂ at our next facility. By harnessing the natural properties of an earth-abundant mineral, limestone, Heirloom has moved quickly from lab to commercial scale and halved the costs of our removals in just over two years. Offtake agreements like these allow us to continue moving quickly towards high scale and low cost direct air capture.”

Hannah Bebbington, Strategy Lead, Frontier: “Getting DAC to gigaton scale requires finding ways to quickly drive down costs. Heirloom and CarbonCapture are each pursuing creative—and distinct—approaches to doing that.”