Co-reactive secures €6.5 million in seed funding for climate-neutral building material technology
29.01.2026
Figure: Co-Reactive
Co-reactive, a climate tech start-up founded in 2024 in North Rhine-Westphalia, has completed a seed financing round totaling €6.5 million. The capital will be used to scale the company's CO₂ mineralization technology, which harnesses CO₂ and binds it sustainably as high-performance building materials, from prototype to industrial application.
The round is led by HTGF. Additional investors include NRW.Bank, HBG Ventures, AFI Ventures (the early-stage impact arm of Ventech), Evercurious VC, and a network of experienced climate tech business angels. The company also receives support from funding programs such as the Federal Industry and Climate Fund (BIK) from the Federal Ministry for Economic Affairs and Energy (BMWE).
Co-reactive has developed a continuous process that converts CO₂ together with natural minerals such as olivine or metallurgical slag (EAF & BOF) into CO₂-negative Supplementary Cementitious Materials (SCMs). The materials enable a significant reduction in the clinker content of cement and building materials – and thus a significant reduction in their carbon footprint. At the same time, they contribute to the compressive strength and durability of building materials. The solution is designed as a drop-in technology and can be easily integrated into existing production processes.
Co-reactive thus addresses two key challenges facing the industry:
- High emissions: Cement production accounts for around eight percent of global CO₂ emissions. With CO₂ pricing on the rise, manufacturing costs are set to double in the coming decade.
- Raw material shortages: Classic cement substitutes such as fly ash and blast furnace slag are becoming increasingly scarce due to the phase-out of coal and the transformation of the steel industry.
With the seed financing, Co-reactive will initially scale its current laboratory and pilot operations in Q2 2026 to a continuously operated demonstration plant with a capacity of around 1,000 tons per year. At the same time, the company is working with industry partners to prepare first-of-a-kind plants on a ten-thousand-ton scale, which are expected to mineralize biogenic or process-related CO₂ streams in the cement and steel industries on site starting in 2027. Dr. Andreas Bremen, co-founder and CEO of Co-reactive: "Funding and science are the basis – real transformation only comes about through entrepreneurial action. With the right co-founders and an interdisciplinary team, we are bringing CO₂ mineralization from the laboratory into continuous industrial operation. The support of our financing partners, with HTGF as lead investor, gives us the clout to deliver proof of concept with a 1,000-ton demonstration plant and prepare for scaling up together with industry. We are building a solution that is urgently needed today so that it can be effective on an industrial scale tomorrow.“ Anna Stetter, Investment Manager, HTGF: ”The construction industry is at a turning point: traditional cement substitutes such as granulated blast furnace slag and fly ash are becoming scarce and expensive due to decarbonization – prices for fly ash have quadrupled in some cases over the last 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 mineralization and plant engineering experts, Co-reactive has the potential to transform the industry in the long term." About Co-reactive Co-reactive GmbH is a climate tech start-up founded in 2024 and based in Düsseldorf. The company is developing a continuous CO₂ mineralization technology that produces novel, highly reactive Supplementary Cementitious Materials (CO-SCMs) from captured CO₂ and magnesium/calcium-containing silicate minerals such as olivine or metallurgical slag. CO-SCMs have a negative carbon footprint and enable a significant reduction in the clinker content of cement and building materials without compromising performance. Co-reactive works along the entire value chain with CO₂ and raw material suppliers, cement and concrete producers, and certification bodies to pave the way from pilot plants to large-scale industrial plants on a 100- to 300-kt scale. The team combines expertise in CO₂ mineralization, heavy industry plant engineering, and commercialization, and has experience in scaling sustainable technologies.
CONTACT
Co-Reactive GmbH
Ludenberger Strasse 44
40699 Erkrath/Germany
