Co-reactive raises €6.5 million to decarbonise the cement industry

German ClimateTech startup Co-reactive has raised €6.5 million in Seed funding to scale its CO₂ mineralisation technology for the construction industry. The round was led by HTGF, with backing from NRW.Bank, HBG Ventures, AFI Ventures (Ventech’s early-stage impact arm), Evercurious VC, and climate tech business angels. Co-reactive has also secured public funding, including the Federal Funding for Industry and Climate (BIK) from the German Federal Ministry for Economic Affairs and Energy (BMWE).

Co-reactive has developed a continuous process that mineralises CO₂ using magnesium- or calcium-rich silicate minerals, such as olivine or metallurgical slags, to produce CO₂-negative supplementary cementitious materials (CO-SCMs). These materials reduce clinker content without sacrificing performance and can be integrated into existing production lines as a drop-in solution.

Dr.-Ing. Andreas Bremen, co-founder and CEO of Co-reactive, said, “With the right co-founders and an interdisciplinary team, we are taking CO₂ mineralisation from the lab into continuous industrial operation. The support of our financing partners, with the HTGF as lead investor, gives us the strength to deliver proof of performance with a 1,000-ton demonstration plant and to prepare large-scale deployment together with industry. We are building a solution that is urgently needed today so that it can create impact at industrial scale tomorrow.”

“The construction industry is at a turning point: Conventional supplementary cementitious materials such as ground granulated blast furnace slag and fly ash are becoming scarce and expensive as decarbonisation progresses – prices for fly ash have in some cases quadrupled over the past two years. Co-reactive offers a scalable alternative that is not only CO₂-negative, but can also be integrated into existing processes as a drop-in solution. With strong unit economics and an experienced team of mineralisation and plant engineering experts, Co-reactive has the potential to transform the industry in a lasting way,” said Anna Stetter, Investment Manager, HTGF.

The new funding will support the scale-up from lab and pilot operations to a continuous demonstration plant with a capacity of around 1,000 tons per year in Q2 2026. The company is also preparing first-of-a-kind industrial plants at the tens-of-thousands-of-tons scale, with on-site CO₂ mineralisation at cement and steel facilities planned from 2027.

Co-reactive works with partners across the value chain, from CO₂ and raw material suppliers to cement producers and certification bodies, as it scales toward industrial units in the 100–300 kiloton range.