Dartmouth-based Planetary Technologies has signed a US$31.3 million (C$43.2 million) agreement with Frontier to remove 115,211 tons of carbon dioxide from the atmosphere between 2026 and 2030.

Blue-chip companies that back Frontier will pay Planetary to scale up its ocean alkalinity enhancement (OAE) operations in one of the world’s largest OAE projects to date.

Frontier works with some of the world’s largest companies to encourage the development of carbon-capture technology. By paying for carbon-capture agreements while the technology is still being developed, Frontier helps young companies grow through the difficult stages of getting to market.

“This offtake with Frontier buyers allows us to demonstrate that ocean alkalinity enhancement can safely and effectively remove CO2 beyond small-scale trials,” said Planetary CEO Mike Kelland in a statement. “We’re eager to show how it can be rolled out responsibly.”

Planetary’s process involves adding dissolved alkaline minerals – such as calcium oxide and magnesium oxide – into coastal waters. This accelerates the ocean’s natural carbon cycle by converting dissolved CO₂ into stable bicarbonate ions, which remain stored in the ocean for more than 10,000 years, the company says. The company uses existing infrastructure, including power plant cooling water discharges, to integrate its process without building new large-scale facilities.

In 2023, Planetary signed a smaller deal with Frontier to remove 937 tons of CO2 with its technology. It now has a facility in operation in Tufts Cove in Dartmouth.

The Frontier statement said Planetary this year completed a pilot project verifying for the first time that tons of CO2 could be removed from the atmosphere using OAE. With the new funding, the company aims to initiate its next phase of operations, with deliveries scheduled to begin in 2026.

OAE has drawn interest because of its potential for large-scale, low-cost carbon removal, said Frontier. Scientists estimate it could remove billions of tons of CO2 annually at costs that could fall below $100 per ton. Frontier has funded a range of approaches to clarify the viability of OAE, supporting trials on land, in freshwater systems, and now in a coastal environment through Planetary.

“Ocean alkalinity enhancement can remove CO2 from the atmosphere extremely cheaply and efficiently,” said Frontier Head of Deployment Hannah Bebbington. “But expanding it beyond small-scale trials calls for ironclad measurement and safety protocols, alongside addressing community concerns. . . . This is the right project and team to pave the way forward for this promising pathway.”

One interesting note about Frontier is that its website says it now has more than 50 companies in its portfolio, and three of them are from the Halifax area.

As well as the recent deal with Planetary, Frontier in July awarded a US$1.75 million contract to pHathom Technologies to remove 510 tons of CO2 from the atmosphere. The company’s technology captures CO2 emissions from coastal bioenergy plants, which are plants that transform organic material from plants and animals into useful energy like heat, electricity, or biofuels. 

Frontier also signed a deal in 2023 with CarbonRun to remove 57,000 tons of CO2, five tons of which have been delivered. CarbonRun adds crushed limestone to rivers to reduce their acidity, storing CO2 as dissolved bicarbonate in the river and ultimately in the ocean.