Climatetech startup Co-reactive is developing a continuous CO₂ mineralisation process that locks emissions into CO₂-negative supplementary cementitious materials (SCMs). Now, the company has raised €6.5 million in seed funding to scale a breakthrough technology that turns CO₂ into high-performance construction materials.
The round was led by High-Tech Gründerfonds (HTGF) with participation from NRW.Bank, HBG Ventures, AFI Ventures, Evercurious VC, and several climate tech angels. Co-reactive also secured seven-figure support from the German Federal Ministry for Economic Affairs and Energy (BMWi).
With fresh capital, Co-reactive is moving from early prototype to meaningful industrial scale. The company will transition its current laboratory and pilot activities into a continuous 1,000-tonne-per-year demonstration plant by Q2 2026. Alongside industrial partners, it is preparing first-of-a-kind plants at tens-of-thousands-of-tons scale, aiming to directly mineralise biogenic or process-related CO₂ streams at cement and steel facilities starting in 2027.
Tackling cement’s twin crisis
Cement production accounts for roughly 8 per cent of global CO₂ emissions, making decarbonisation efforts urgent. Rising CO₂ pricing is expected to push production costs upward, potentially doubling within a decade. At the same time, traditional cement substitutes like fly ash and ground granulated blast furnace slag are becoming scarce due to the coal phase-out and shifts in steel production methods.
Co-reactive targets both challenges simultaneously. By offering a reliable, scalable source of high-reactivity SCMs, the startup provides an alternative to declining raw material streams. And with its CO₂-negative profile, the technology reduces cement’s carbon intensity at a time when regulators and industry leaders are demanding cleaner solutions.
Turning industrial CO₂ into a valuable material stream
Headquartered in Düsseldorf, Co-reactive was founded in 2024 by Dr. Andreas Bremen, Orlando Kleineberg, and Willi Peter. It is building an end-to-end ecosystem, collaborating with CO₂ suppliers, raw material providers, cement and concrete manufacturers, and certification bodies. The long-term vision points to 100–300 kilotonne industrial plants that bring CO₂ mineralisation into mainstream production. The team combines expertise in mineralisation chemistry, plant engineering, commercialisation, and scaling climate technologies. These are essential to turn groundbreaking ideas into a globally deployable industrial solution.
Co-reactive’s core innovation lies in transforming CO₂ from a liability into a building asset. Its process reacts emissions with natural minerals such as olivine or metallurgical slags from EAF and BOF steelmaking. The result is a new class of CO₂-negative SCMs that enhance compressive strength and durability while allowing producers to drastically cut clinker content, one of the biggest drivers of cement’s emissions profile.
Designed as drop-in technology, the solution integrates into current cement and materials production lines without requiring a complete overhaul. By permanently binding CO₂ within construction materials, the process addresses both environmental and performance demands of a sector under intense pressure to decarbonise.
Dr.-Ing. Andreas Bremen, Co-Founder and CEO of Co-reactive, said: “Funding and scientific research form the foundation – but real transformation only happens through entrepreneurial action. 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.”
Anna Stetter, Investment Manager, HTGF: “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.”
