Tech Giants Support Frontier’s $1.75M Bet on Ocean and Rock-Based Carbon Removal

Key Impact Points:

• $1.75M in new carbon removal prepurchases were made by Stripe, Shopify, and Google via Frontier to support early-stage climate tech firms.
• Two emerging carbon removal approaches—ocean alkalinity enhancement and surficial mineralization—receive critical backing to test and scale innovative technologies.
• First customers for two of the three startups, accelerating pathways to billion-ton-per-year removal potential.

Frontier Backs Early Carbon Removal Innovators

Frontier has announced $1.75 million in prepurchase agreements to advance three early-stage carbon removal companies: Karbonetiq (U.S.), Limenet (Italy), and pHathom (Canada). The deals were made on behalf of Stripe, Shopify, and Google.

The funding targets two high-potential, underdeveloped pathways: ocean alkalinity enhancement (OAE) and surficial mineralization, both seen as scalable solutions to remove billions of tons of CO₂ annually.

“Frontier buyers are the first customers for two out of three companies.”

Ocean Alkalinity Enhancement: Boosting Nature’s CO₂ Sponge

OAE works by raising the alkalinity of ocean surface waters, enhancing their capacity to absorb and store carbon as bicarbonate. One technique, ocean liming, involves dispersing fast-dissolving minerals such as quicklime into the ocean—potentially reversing local ocean acidification and benefiting marine life.

pHathom (Canada, 510 tons) uses a weathering reactor filled with limestone, seawater, and biocatalysts to capture CO₂ from coastal bioenergy plants and convert it into stable ocean-bound bicarbonates.

“Their biocatalyst could facilitate the wider use of limestone for other carbon removal approaches.”

Limenet (Italy, 330 tons) is developing a zero-carbon electric kiln to produce clean quicklime. This novel feedstock can be used across multiple applications—including ocean liming, mineral looping DAC, and industrial decarbonization.

“Limenet’s carbon-free quicklime enables a range of promising approaches to scale.”

Surficial Mineralization: Speeding Up Earth’s Natural Process

Surficial mineralization accelerates the absorption of CO₂ by exposing alkaline minerals through crushing and milling, compressing geological processes into manageable timeframes. When done sustainably, it can also clean mine waste or recover key metals.

Karbonetiq (U.S., 2,142 tons) harnesses alkaline industrial residues that naturally absorb CO₂, using a passive aeration system and monitoring software to track carbon capture.

“Karbonetiq’s process could significantly improve mineralization rates and reduce the land required for deployment.”

Why It Matters

These investments mark Frontier’s fifth round of prepurchases, designed to help early-stage companies de-risk and commercialize transformative carbon removal technologies. Both OAE and surficial mineralization remain technically promising but need real-world pilots and reliable offtake partners to prove scalability.

Frontier’s strategic backing aims to accelerate precisely that.

Related Article: Frontier Commits $33 Million to Carbon Removal Through Enhanced Rock Weathering by Eion