An agreement between Montreal-based Exterra Carbon Solutions and German chemicals firm BASF will explore operating carbon capture and storage (CCS) projects to alleviate emissions from hard-to-abate Quebec industries.

Using BASF’s OASE blue gas treatment technology in tandem with Exterra’s Reactive Oxide to Carbonate (ROC) system, the greenhouse gas emissions from these industries will be weathered into a mineral from mine tailings called magnesium oxide, durably trapping carbon.

Steps commonly associated with CCS such as removing humidity in the gas stream “are not required to be done in a typical capture unit if it’s combined with a mineralization unit” like Exterra’s, Olivier Dufresne, CEO and co-founder of Exterra, said in an interview with Sustainable Biz Canada.

The expectation is to run pilot programs in 2025 with BASF and Quebec companies.

OASE to ROC

The pilot programs would deploy a post-combustion carbon capture technology named OASE blue on the emitter’s facility.

CO2 will be captured from the on-site emissions and purified with an amine solution. The CO2 would then be processed by ROC reactors located with the BASF carbon capture, blending the gas with water and flowing the mixture to a supply of magnesium oxide. The CO2 then binds with the mineral, producing magnesium carbonate.

“We will truck in magnesium oxide and truck out magnesium carbonate,” Dufresne said, summarizing the process.

Each project will be capable of capturing and storing over one tonne of CO2 per day.

Exterra’s ROC rapidly accelerates the natural storage of CO2 in rocks, Dufresne said, mineralizing the greenhouse gas in four hours, seven million times faster than nature. The magnesium carbonate is durable, staying inert for thousands of years, and only releases CO2 in the unlikely event of extreme heat or exposure to acids.

The company is mapping out the opportunity to sell the magnesium carbonate as a filler in concrete, as wallboard material or to rehabilitate mine sites.

This partnership would not require substantial infrastructure for CCS, such as expansive underground storage sites for CO2 or long pipelines, Dufresne said, noting a lack of these structures in Quebec. As a result, the projects can be finished three times faster compared to underground storage projects, with benefits such as rehabilitating mines and extracting by-products like silica and nickel.

Commercializing Exterra's carbon storage

The relationship comes as a result of BASF looking to sell its OASE technology. It reached out to Exterra because of the firm's surface-level CO2 sequestration that does not require expansive storage infrastructure, Dufresne said. The absence of a “practical risk of reversal” - CO2 leaking after storage - also interested BASF, he added.

If the tests are promising, commercialization could follow.

Dufresne expects a range of potential clients, emitting 50,000 to one million tonnes of CO2 per year. The company’s initial preference is firms emitting hundreds of thousands of tonnes per year.

Commercial-level sites would be located within 100 kilometres of Exterra’s Hub One, a project anticipated to store approximately 500,000 tonnes of CO2 per year. Dufresne previously told Sustainable Biz Canada construction of Hub One is expected to start in 2027 if permitting progresses according to plan.

Industries the partners intend to focus on include steel and cement, with pulp and paper and waste-to-energy as two others Dufresne finds interesting.

What piqued his interest in the latter two industries is the production of biomass CO2 that qualifies as carbon removal credits. In high demand, the carbon credits could be a new revenue stream for emitters utilizing carbon removal technology, he said.

The steel and cement industries are large polluters with ambitious climate targets, so CCS can be a tool to achieve the companies’ environmental goals. Additionally, it can relieve a carbon tax burden.

Magnesium oxide as a direct sorbent

Development of CCS technology is leading to other cost-effective novel ideas Exterra hopes to explore.

Dufresne said one example is using the magnesium oxide as a sorbent, rather than a synthetic material. The mineral could be placed on a flue gas source to directly mineralize into magnesium carbonate, preventing the need to regenerate the sorbent through an energy-intensive process.

Exterra is in the final phase of its Series A fundraise, Dufresne said, and further details on its pilots with BASF, such as participants and locations, will be unveiled in 2025.