Microsoft and carbon dioxide removal (CDR) solutions provider Neustark announced today a multi-year offtake agreement, with Neustark providing Microsoft with credits from the removal of biogenic carbon from biogas plants for storage in recycled construction materials.

Founded in 2019, Switzerland-based Neustark’s technology uses recycled materials such as concrete from demolished buildings as permanent storage for the CO₂ removed from the atmosphere. The solution utilizes a mineralization process, through which captured biogenic CO2 from partnering biogas plants is liquified and transported to partnering construction waste recycling sites for use as an add-on to the existing recycling process. Neustark’s technology triggers an accelerated mineralization process, thus binding the CO2 permanently to the pores and surface of the granules. The carbonated granules can then be used by recyclers to build roads or to produce recycled concrete.

Neustark currently operates at 14 sites with an aggregate capacity of over 5,000 tons of CO2 per year, with a goal to scale to capture one million tons of CO2 in 2030.

Under the new agreement, Neustark will deliver 27,600 tons of carbon removal credits to Microsoft over the course of 6 years. The company started collaborating with Microsoft in 2022 and receives support as part of the “Microsoft for Startups” program.

Lisa Braune, Head of CDR at Neustark, said:

“We turn the world’s largest waste stream – demolition concrete – and other mineral waste material into a carbon sink. Our solution makes an impact now: we have removed more than 1000 tons of CO2 to date, and we are expanding our footprint quickly. Working with such carbon removal pioneers such as Microsoft significantly helps to scale our impact and the CDR industry as a whole.”

The deal marks the latest in a growing series of carbon removal investments for Microsoft, forming part of the company’s initiative to become carbon negative by 2030, and to remove all of its historical emissions by 2050. Microsoft’s recent carbon removal deals include large-scale nature-based carbon removal agreements with Chestnut Carbon and Brazilian reforestation-focused startup Mombak, an agreement in January with soil carbon removal solutions startup Grassroots Carbon, other providers through technologies spanning direct air capture (DAC), ocean-based carbon removal, and biochar-based solutions.

Brian Marrs, Senior Director of Energy & Carbon Removal at Microsoft, said:

“Neustark deploys a model for delivering high-quality, highly-durable carbon removal that is both scalable and measurable to help organizations towards a sustainable future. Through this six-year purchase agreement, we are excited to continue working with neustark to advance Microsoft’s carbon removal purchasing towards our goal of becoming carbon negative by 2030.”