Canadian firm Arca has signed a ten-year offtake agreement with Microsoft to remove around 300,000 tonnes of carbon dioxide through industrial mineralisation, a process that stores atmospheric CO₂ in solid mineral form using industrial waste.
Arca’s method repurposes materials such as mine tailings and waste rock to accelerate the natural geochemical process of carbon mineralisation. The approach captures and permanently stores carbon dioxide as stable carbonate minerals while reducing the environmental impact of mining waste.
“Arca was built on the foundation of more than 20 years of academic research, dozens of field trials and collaborations with more than 30 mining companies around the world,” said Dr Greg Dipple, Arca’s co-founder and Head of Science.
Arca completed its first full-scale mineralisation demonstration project at an operating mine in 2025 and is expanding its pipeline of projects to larger scales. Microsoft’s agreement is expected to support the development of commercial operations.
The announcement was welcomed by Tim Hodgson, Canada’s Minister of Energy and Natural Resources.
“The next generation of clean growth will be built by Canada’s first-class innovation ecosystem – companies like Arca, which are turning Canadian ingenuity into global leadership. Carbon removal technologies are not only strategic tools we can use to tackle climate change, they create good jobs and position Canada at the forefront of the global opportunity of a low-carbon economy.”
Microsoft said the deal broadens its carbon removal portfolio as it works towards becoming carbon negative by 2030.
“This offtake agreement diversifies Microsoft’s carbon removal portfolio into a pathway that combines scalability and permanence,” said Phil Goodman, Director of Microsoft’s Carbon Dioxide Removal Programme. “Arca brings notable scientific expertise and has proven they can sequester carbon through their demonstration project, giving us confidence to enter into a multi-year agreement.”
Arca stated that industrial mineralisation offers practical benefits, including the use of abundant existing waste materials, limited demand for additional energy or land, and secure, long-term carbon storage.
“We have a unique opportunity to utilise one form of waste (mine tailings) to neutralise another (excess atmospheric CO₂). The result is less waste and a healthier environment,” said Paul Needham, Arca’s Chief Executive. “This agreement with Microsoft validates industrial mineralisation as a viable pathway for durable carbon removal with the potential to scale and meaningfully contribute to global climate goals.”
The deal highlights a growing interest in carbon removal technologies that offer verifiable and durable storage as part of broader efforts to mitigate industrial emissions.
