Halifax-based pHathom Technologies has closed a $4 million seed round, which will help to finance pilot projects to validate its carbon capture technology.

The company, whose technology captures carbon from coastal bioenergy facilities, issued a press release Thursday saying Boston-based Propeller Ventures led the round. The other investors are the New Brunswick Innovation Foundation, Invest Nova Scotia and Carmeuse Ventures of Belgium.

“Reducing emissions from large facilities isn’t enough unless the solution is durable, verifiable, and responsible,” said pHathom CEO Dr. Kimberly Gilbert in the statement. “This investment allows us to demonstrate a bioenergy carbon capture pathway that works within existing infrastructure, meets high scientific and measurement standards, and can be governed using established regulatory frameworks.”

With the closing of this round, pHathom now has $12 million in committed capital. This pool of money includes funds received from: the Bioenergy Carbon Capture and Marine Storage Project supported by Canada’s Ocean Supercluster; a grant from the B.C.-based climate action fund NorthX; and a deal to remove carbon through Frontier, which signs carbon-capture agreements on behalf of leading tech companies.

Founded in 2024, pHathom has developed a process that uses seawater and limestone to capture CO2 at plants that produce energy by burning biomass. It converts the CO2 into dissolved inorganic carbon forms that already exist naturally in seawater. After treatment, the water is returned to the ocean under closely monitored conditions.

According to the company, the process is designed to achieve durable and verifiable carbon storage without relying on new pipelines, long-distance transport of carbon dioxide, or underground geological injection. The system operates within existing industrial sites and regulatory frameworks and does not involve direct intervention in the marine environment.

In an interview, Gilbert said the first pilot project will take place this year at the Huntsman Marine Science Centre in St. Andrew’s, N.B. The centre will conduct eco-toxicology tests on the water discharge to ensure it does no harm to 13 different marine species.

The second pilot will be about 10 times as large, and will take place at a community college in 2027.

Gilbert admitted the pHathom process is capital-intensive and that the company next year will begin work on a Series A round that it hopes will finance even larger projects.

Alastair Jarvis, pHathom’s vice-president of external affairs, said in the interview that the team is excited to hear Prime Minister Mark Carney talk of Canada as an energy superpower with a commitment to sustainability. What pHathom is focusing on is supplying the evidence that carbon capture is effective in supporting that goal.

“The [pHathom] team is addressing carbon removal with highly scalable, customer-first technology for durable carbon removal from existing emitters,” said Propeller Ventures Partner Steven Fox. “This financing positions pHathom well to serve initial partners, validate impact, and play a meaningful role in the carbon removal market.”