Customers also served as development partners

Neustark’s technology repurposes concrete from demolished buildings and other mineral waste material as permanent storage for removed CO₂, using a process known as mineralization. Biogenic CO₂ is captured from partnering biogas plants, then liquified and transported to partnering construction waste recycling sites. There, as an add-on to the existing recycling process, the carbon dioxide is injected into demolition concrete granules. 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.

Not only does this solution already remove thousands of tons of CO2 from the air and store it permanently, it also contributes to making the building industry more circular.

"We conducted our first material tests with carbonated concrete and found that the compressive strength increased, which is very attractive for our partnering concrete recyclers and producers. We collaborated with EMPA to understand why this happened, which significantly boosted us."

Tiefentaler explains that neustark's transition from research to business was very smooth. "We always had a good division of tasks and brought in people with complementary expertise, such as plant construction. We developed concepts with our customers, ensuring they were always close to the product. In the early phase, we sought customers who were curious to co-develop and engage in new ideas. The journey doesn't end with the first customer; it requires pioneers at various levels and for different prototypes."

"The journey doesn't end with the first customer; it requires pioneers at various levels and for different prototypes." – Johannes Tiefentaler - Co-Founder & Co-CEO neustark AG

"Our partners use the carbonated, recycling concrete granules to produce more sustainable building materials. More and more real estate developers – such as the city of Zurich and private builders – are looking to build with eco-friendlier material. The construction sector contributes heavily to CO2 emissions, so finding ways to decarbonize building is in the interest of everyone," says Johannes, referring to the construction sector's high CO2 emissions.

Building trust by demonstrating the solution

Looking ahead, Neustark's focus is on further scaling. "Now that we have a proven solution, it's about rolling it out widely. We have sites in Switzerland, Germany, Liechtenstein and Austria in operation, and many other sites being built across Europe. Next year, we plan to enter the North American market. Our expansion strategy is based on clusters: We roll out our solution in areas with significant demolition concrete recycling already happening – so larger urban clusters –, by forming partnerships with biogas plants and concrete recyclers to build capture and storage sites.”

“To reach our goal of durably removing 1 million tons of CO2 in 2030, we will deploy around 1000 sites. Certainly an ambitious plan, but a doable one – and one certainly needed to help ensure a bright future of all generations on our planet."

neustark AG

Storing CO2 permanently in concrete