A startup in Nova Scotia is currently testing a technique to capture and store more carbon in the ocean through a new pilot facility to validate the concept. The ocean serves as a significant repository for excess carbon dioxide, having absorbed approximately 30 percent of all human-induced carbon emissions since the 1980s.
pHathom, the company behind the initiative, aims to enhance carbon removal by capturing carbon dioxide and transforming it into a form suitable for safe storage in the ocean over millennia. The testing of their method will take place at the Huntsman Marine Science Centre in St. Andrews, N.B., as a pivotal initial step to demonstrate its safety and efficacy.
The process involves replicating a natural phenomenon where raindrops absorb carbon dioxide from the atmosphere, becoming slightly acidic. When these raindrops encounter alkaline rocks like limestone, a portion of the rock dissolves, reducing water acidity and converting carbon dioxide into bicarbonate. This bicarbonate can then be stored in the ocean for thousands of years, effectively sequestering carbon dioxide from the atmosphere.
pHathom’s method entails treating seawater by exposing it to the exhaust of a biomass power plant to increase its acidity. The acidic water is mixed with small limestone particles in a tank, converting the carbon dioxide into bicarbonate, before being reintroduced into the ocean with a pH level similar to regular seawater.
Different companies in Nova Scotia are exploring variations of carbon removal techniques, including alkalinity enhancement. Planetary, operating a project in Halifax’s Tufts Cove, adds alkaline rock to seawater to elevate its pH for better carbon dioxide absorption. Similarly, CarbonRun implements a comparable approach along Nova Scotia rivers.
pHathom’s process boasts efficiency by using concentrated carbon dioxide, facilitating a more streamlined operation. The pilot phase aims to capture 0.1 tonnes of carbon dioxide daily, with testing tanks producing treated water to monitor its impact on various marine species over a three-month period.
If successful, pHathom intends to expand its operations with a second test site in Nova Scotia next year, integrating the reactor into a building transitioning from a fossil-fuel boiler to a biomass system. Despite the potential of carbon removal technologies, scaling up remains a significant challenge, as indicated by Intergovernmental Panel on Climate Change (IPCC) models.
While considerable energy consumption is required for these methods, researchers and experts emphasize the importance of exploring all viable removal technologies amid the climate crisis. Canada has been recognized as a leader in ocean alkalinity enhancement research, with calls for international collaboration and regulatory frameworks.
Despite economic uncertainties affecting carbon capture projects in Canada, optimism persists among industry players like pHathom, preparing for a future where action against climate change becomes imperative.