Frontier facilitates first carbon removal purchases

June 29, 2022

Earlier this year, Stripe, Alphabet, Shopify, Meta, and McKinsey Sustainability launched Frontier, an advance market commitment to accelerate the development of carbon removal technologies. A few months later, after careful review from an advisory panel of 19 scientists and industry experts, Frontier has facilitated its first purchases—from AspiraDAC, Calcite-Origen, Lithos Carbon, RepAir, Travertine, and Living Carbon—on behalf of Stripe.

Carbon dioxide removal (CDR) is critical to achieving climate goals, alongside radical emissions reductions. Models project that by 2050 we will need to permanently remove billions of tons of CO₂ from the atmosphere every year. To date, fewer than 10,000 tons have been removed in total.

Frontier aims to catalyze new solutions that bridge this enormous gap. These initial six companies represent a diverse group of promising, early-stage technologies, and we are pleased to be the first customer for all of them.

The majority of Frontier’s $1B of committed capital will go toward multiyear offtake agreements designed to give the most promising carbon removal solutions a pathway to scale. With an offtake, Frontier’s members agree to pay for future carbon removal supply at the time it’s delivered. However, in order for there to be enough companies eligible for offtakes in future years, we must get a critical mass of promising companies to the starting line now. Over the next few years, low-volume prepurchases—like those we’re announcing today—will continue to be an area of focus for Frontier.

Observations from this purchase cycle

Several themes emerged from the 26 applications reviewed as part of this round of purchases:

  • Increasing project diversity | A wider variety of solutions is meeting or exceeding our bar for durability. Applications spanned nine distinct approaches to CDR, including direct ocean capture, biomass burial, and synthetic biology. We’re also seeing increased diversity within each pathway: direct air capture (DAC) applications ranged from electrochemical capture on railcars to modular, solar powered metal-organic framework (MOF) adsorption systems.
  • Electrified DAC | DAC at scale will require huge amounts of energy. An increasing number of projects are using electricity, as opposed to heat, to power their processes. While these approaches tend to be relatively energy-intensive in their early stages, they have the potential to become energy-efficient systems that harness renewable energy as the grid decarbonizes.
  • Scalable sources of alkalinity | Because CO₂ is an acidic molecule, rising global CO₂ concentrations can be neutralized by alkalinity. We’re encouraged by ideas for safe alkalinity production at scale. One approach, using large-scale waste sources such as mine tailings, could remove up to 0.5 gigatons of CO₂ a year. Alkalinity can also be produced electrochemically, for example, as part of ocean alkalinity enhancement (OAE). We are looking for new ways of improving the energy efficiency of alkalinity production, while considering how the resulting acid coproduct can be managed safely.
  • MRV innovation | Enhanced rock weathering (ERW) and OAE are examples of high-potential, open systems whose effects are intrinsically harder to measure than closed systems (like DAC, where the CO₂ stream can be calculated directly). This means they need to be paired with even stronger measurement, reporting, and verification (MRV) methodologies to reduce uncertainty. We are encouraged by the increasing number of projects treating measurement methodologies as part of the core roadmap.

The projects

Stripe will spend $2.4M buying carbon removal from these six companies, with another $5.4M contingent on projects reaching agreed upon technical milestones. Prices range between $500 and $1.8K per ton of carbon removed, and we’re excited to be the first customer for all six projects. To view project applications, purchase contracts, and renewal criteria, visit Frontier’s GitHub.


Direct air capture | Sydney, Australia | 500 tons

AspiraDAC is building a modular, solar-powered DAC system with the energy supply integrated into the modules. One of the biggest opportunities for DAC to scale is by increasing its ability to integrate with renewable electricity. AspiraDAC’s modular approach allows it to experiment with a more distributed scale-up. Its MOF sorbent has low temperature heat requirements and cheap material inputs, increasing the likelihood that AspiraDAC can help accelerate the production of lower-cost MOFs, which historically have been expensive and difficult to synthesize.


Direct air capture | US and UK | 278 tons

This project blends the novel Calcite air contactor design from 8 Rivers with Origen’s strengths in calcination. Their DAC technology accelerates the natural process of carbon mineralization by contacting highly reactive slaked lime with ambient air to capture CO₂. The resulting carbonate minerals are calcined to create a concentrated CO₂ stream for geologic storage, and then looped continuously. The inexpensive materials and fast cycle time make this a promising approach to affordable capture at scale.


Enhanced weathering | San Francisco, CA, US | 640 tons

Lithos accelerates the natural ability of rocks to absorb CO₂ by spreading superfine crushed basalt on farmlands and measuring the removal empirically. They’re pioneering a novel measurement technique that more accurately quantifies the carbon permanently removed from enhanced weathering.


Direct air capture | Tel Aviv, Israel | 199 tons

RepAir uses clean electricity to capture CO₂ from the air using a novel electrochemical cell, and then stores the CO₂ underground via a partnership with Carbfix. The demonstrated energy efficiency of RepAir’s capture step is already notable and continues to advance. This approach has the potential to deliver low-cost carbon removal that minimizes strain on the electrical grid.


Enhanced weathering | Boulder, CO, US | 365 tons

Travertine is working to reengineer chemical production for CO₂ removal. Using electrochemistry, Travertine produces sulfuric acid to accelerate the weathering of ultramafic mine tailings, releasing CO₂ reactive elements that convert CO₂ into carbonate minerals that are stable on geologic timescales. Their process also releases metals that are critical to decarbonizing transportation and electricity generation.

Living Carbon

Biomass carbon removal & storage | Hayward, CA, US | 0 tons

Living Carbon is developing a novel approach to synthesize a durable biopolymer within algae to sequester atmospheric CO₂ at scale. As a first step, Living Carbon is conducting research to select the optimal algae strain and demonstrate expression and activity of key enzymes of the biopolymer synthesis pathway within the algae. Initial research also aims to better understand how the field thinks about the durability of sporopollenin. Synthetic biology is a nascent but exciting tool for carbon removal that has promise both as a standalone solution like Living Carbon and as an amplifier across pathways like bio-enhanced mineralization.

Be part of our next purchases

Frontier is an advance market commitment to buy an initial $1B+ of carbon removal between 2022 and 2030.

If you are a carbon removal supplier building an early-pilot, precommercial facility, or an at-scale deployment, we’d love to hear from you. Learn a bit more about our next purchase cycle and how to get in touch.

If you are interested in becoming a buyer of carbon removal through Frontier, please get in touch at