In a bet on scaling carbon removal technology breakthroughs, Frontier pre-purchased $1.75 million of three early climate businesses—Karbonetiq (US), Limenet (Italy), and pHathom (Canada). The buys, which are included in Frontier's fifth round of investment, were made on behalf of climate leader businesses Stripe, Shopify, and Google. The transactions are the first commercial customer purchases for two of the three businesses, a key milestone for the quickly developing carbon removal ecosystem.

Both of the three projects aim at two strongly promising yet not well-studied carbon dioxide removal (CDR) methods: surficial mineralization and ocean alkalinity enhancement (OAE). Both technologies can potentially capture billions of tons of CO₂ per year if they were developed and scaled. With these prepurchases, Frontier is seeking to speed up the development and deployment of frontier climate solutions while generating proof of the effectiveness of such solutions under real-world conditions.

Ocean Alkalinity Enhancement accomplishes this by enhancing the ability of oceans to capture and store CO₂, mainly by raising the alkalinity of the surface waters. Ocean liming, the most promising among all OAE strategies, involves the injection of high-purity alkaline material like quicklime into seawater. It not only stores atmospheric CO₂ but also alleviates coastal ocean acidification, hence benefiting marine organisms such as coral reefs and shellfish beds. But one of the main issues with scaling up this process is energy- and emission-grabby production of quicklime, a limitation that Frontier aims to eliminate with its Limenet investment.

Limenet, headquartered in Lecco, Italy, is at the forefront of solving that problem. The company is building its own custom-made electric kiln which makes zero-carbon quicklime, a carbon-free feedstock for ocean liming but also for other carbon removal technologies like surficial mineralization and looping minerals in DAC systems. The company says that its clean quicklime is at the heart of making a variety of decarbonisation approaches from industrial decarbonisation up to new CDR technology.

Conversely, surface mineralization mimics and speeds up the natural method by which CO₂ reacts with alkaline minerals—under normal circumstances in mine wastes or industrial byproducts—to create permanent carbonates. This, under normal circumstances taking thousands of years, can be accelerated to take place within decades by grinding the minerals into a fine powder, effectively expanding the reactive mineral surface area. Aside from carbon sequestration, the technology facilitates the treatment of mine wastes and recovery of essential metals for the energy transition. Nonetheless, energy consumption and associated greenhouse gas emissions due to mineral processing and transportation are still major hindrances to commercialization.

California startup Karbonetiq is taking them head-on. Working with alkaline industrial waste that has an innate ability to absorb CO₂, the firm has created a passive aeration technology with real-time sensor and software to increase and measure carbon capture through mineralization. The technology is co-located on existing infrastructure with low land use and logistics cost. Karbonetiq's pre-purchase by Frontier will enable scaling of this compelling model, which seeks to integrate operating efficiency with verifiable carbon removal results.

The third of the Frontier funding recipients, pHathom, is a Nova Scotia, Canada-based business at the intersection of ocean alkalinity enrichment and carbon capture via bioenergy. The company sequesters CO₂ from coastal bioenergy power stations in a proprietary weathering reactor involving limestone, seawater, and biocatalysts. It releases the resulting bicarbonate solution into the ocean safely as a low-risk, scalable supplement to conventional geologic CO₂ storage. This method not only sequesters carbon from the air but is also compatible with coastal DAC, BECCS and CCS infrastructure. pHathom's biocatalyst technology has a stunning effect on limestone reactivity, unlocking much wider applications in marine and terrestrial carbon removal.

This round comes on the heels of Frontier's bigger step in enabling climate-leading finance. Previously, it led a $58 million carbon removal transaction based on biomass for Stripe, Alphabet, McKinsey, and JPMorgan. The $1.75 million raise, albeit smaller, is a big step to drive early-stage growth in multi-gigaton CO₂ removal technology.

"Pre-purchases enable us to move faster with new solutions and test their performance ahead of scale," Frontier stated in its press release, highlighting commercial traction's significance for establishing trust and scalability for nascent CDR technologies.

By funding initiatives such as Karbonetiq, Limenet, and pHathom, Frontier is not only investing in science-grounded carbon removal methods but also pushing their stage of preparedness for commerce—spanning the important distance between laboratory success and commercial deployment. The project also puts Frontier's goal of scaling up promising climate solutions that are successful on the climate and financial well-being over the long term in focus.