A startup in Nova Scotia is currently conducting trials on a new method to capture and retain more carbon in the ocean, utilizing a pilot facility to validate the concept.
The ocean has been a significant repository for excess carbon dioxide, absorbing approximately 30% of all carbon emissions generated by human activities since the 1980s.
The company, pHathom, is striving to enhance the removal of emissions from the atmosphere by capturing carbon dioxide and transforming it into a form that can be securely stored in the ocean for thousands of years.
The initial testing of this method will take place at the Huntsman Marine Science Centre, a nonprofit research and educational establishment in St. Andrews, N.B.
Kimberly Gilbert, the co-founder and CEO, emphasized that the pilot phase is crucial in establishing the safety and efficacy of their approach at a local level before scaling up.
The company’s technique replicates a natural process where raindrops absorb carbon dioxide from the air, becoming slightly acidic. When these raindrops come into contact with alkaline rocks like limestone, a portion of the rock dissolves, reducing the water’s acidity and converting the carbon dioxide into bicarbonate.
Upon reaching the ocean, the bicarbonate can be preserved for tens of thousands of years, effectively sequestering carbon dioxide from the atmosphere. Gilbert explained that they simulate this process in a controlled reactor.
Their method involves exposing seawater to the emissions of a biomass power plant, acidifying the water. This acidic water is then 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.
Other companies in Nova Scotia are also exploring variations of carbon removal techniques, particularly in the field of alkalinity enhancement. Planetary and CarbonRun are among them, each working on projects that involve altering seawater pH levels to enhance carbon dioxide absorption.
pHathom’s approach is distinguished by its utilization of highly concentrated carbon dioxide, making the process more efficient. The controlled reactor setting allows for direct monitoring of environmental impacts.
During the pilot phase, the company aims to capture 0.1 tonnes of carbon dioxide daily. This amount, though modest, is significant when compared to the emissions produced by major coal-fired power plants like Belledune in northern New Brunswick.
The testing process involves producing treated water for experimental tanks to observe the effects on various marine species over a three-month period at the Huntsman Marine Science Centre.
Davide Asnicar, an associate research scientist at the center, noted the numerous uncertainties surrounding pHathom’s innovative process and emphasized the importance of understanding its safety thresholds.
If successful, pHathom plans to expand its operations with a second test site in Nova Scotia the following year, integrating their reactor into a building transitioning from a fossil-fuel boiler to a biomass system.
However, the scalability of any carbon removal technology poses a significant challenge. According to the Intergovernmental Panel on Climate Change (IPCC), global carbon dioxide removal needs to reach between 10 and 20 gigatonnes annually to limit global warming to 1.5 degrees Celsius.
Katja Fennel, an oceanography professor at Dalhousie University, expressed concerns about the geochemical and regulatory obstacles that could impede the scaling of ocean alkalinity enhancement as a viable climate mitigation strategy.
Despite the challenges, Fennel stressed the importance of investigating promising removal technologies in light of the climate crisis, provided that efforts to transition away from fossil fuels continue.
A recent Canadian Senate report highlighted Canada’s leadership in ocean alkalinity enhancement research and called for federal support in developing international implementation and regulatory frameworks.
While domestic climate policies face economic uncertainties, Kimberly Gilbert remains hopeful that the urgency of the climate crisis will eventually drive global action, emphasizing the need to have proven technologies ready for implementation when that moment arrives.
