Co-reactive secures €6.5 million in seed funding for CO₂-negative construction materials technology

• The climate-tech start-up Co-reactive closes a seed financing round totaling €6.5 million.
• The company’s technology continuously mineralizes CO₂ and converts emissions into high-performance, CO₂-negative supplementary cementitious materials (SCMs).
• The financing round is led by High-Tech Gründerfonds (HTGF). Further investors: NRW.Bank, HBG Ventures, AFI Ventures (the early-stage impact arm of Ventech), Evercurious VC as well as climate tech business angels. In addition, the company receives seven-figure funding from the German Federal Ministry for Economic Affairs and Energy (BMWE).
• Co-reactive is now scaling from prototype to a continuous 1,000-ton demonstration plant and preparing industrial pilot plants at the tens-of-thousands-of-tons scale.

Founded in 2024, climate-tech start-up Co-reactive from North Rhine-Westphalia (NRW) has completed a seed financing round totaling €6.5 million. The capital will be used to scale the company’s CO₂ mineralization technology – which makes use of CO₂ and binds it permanently in high-performance construction materials – from prototype to industrial application.

The round is led by HTGF. In addition, NRW.Bank, HBG Ventures, AFI Ventures (the early-stage impact arm of Ventech), Evercurious VC and a network of experienced climate tech business angels are investing. The company also receives further support through grants such as 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 converts CO₂ together with natural minerals such as olivine or metallurgical slags (EAF & BOF) into performance-enhancing, CO₂-negative supplementary cementitious materials (SCMs). These materials enable a significant reduction of the clinker content in cement and construction materials – and thus a substantial reduction of their CO₂ footprint. At the same time, they increase compressive strength and durability. The solution is designed as a drop-in technology and can be integrated into existing production processes.

In doing so, Co-reactive addresses two key challenges of the industry:

• High emissions: Cement production accounts for around eight percent of global CO₂ emissions. With rising CO₂ pricing, production costs risk doubling over the next decade.
• Raw material scarcity: Conventional cement substitutes such as fly ash and ground granulated blast furnace slag are becoming increasingly scarce due to the coal phase-out and the transformation of the steel industry.

With the seed financing, Co-reactive will scale its current lab and pilot operations in Q2 2026 to a continuous demonstration plant with a capacity of around 1,000 tons per year. In parallel, the company is preparing, together with industrial partners, first-of-a-kind plants at the tens-of-thousands-of-tons scale that from 2027 onwards are intended to mineralize biogenic or process-related CO₂ streams directly on site at cement and steel plants.

Quotes on the financing

Dr.-Ing. Andreas Bremen, Co-Founder and CEO of Co-reactive: “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 mineralization 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 decarbonization 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 mineralization and plant engineering experts, Co-reactive has the potential to transform the industry in a lasting way.”

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About Co-reactive
Co-reactive GmbH is a climate-tech start-up founded in 2024, supported by the EXIST program of BMWE and headquartered in Düsseldorf. The company is developing a continuous CO₂ mineralization technology that uses captured CO₂ and magnesium-/calcium-containing silicate minerals such as olivine or metallurgical slags to produce novel, highly reactive supplementary cementitious materials (CO-SCMs). The CO-SCMs have a negative CO₂ footprint and enable a significant reduction of the clinker content in cement and construction materials without compromising performance. Co-reactive works along the entire value chain with CO₂ and raw material suppliers, cement and concrete producers as well as certification bodies to pave the way from pilot plants to large-scale industrial plants in the 100- to 300-kilotons range. The team combines expertise in CO₂ mineralization, plant engineering, commercialization, and brings experience in scaling sustainable technologies.

Contact
Co-reactive GmbH
Willi Peter, Co-founder & Chief Commercial Officer
willipeter@co-reactive.com

About HTGF – High-Tech Gründerfonds
HTGF is one of the leading and most active early-stage investors in Germany and Europe, financing start-ups in the fields of deep tech, industrial tech, climate tech, digital tech, life sciences and chemistry. With its experienced investment team, HTGF supports startups in all stages of their development on the way to becoming international market leaders. HTGF invests in the pre-seed and seed phase and can participate significantly in further financing rounds. Since its founding in 2005, it has financed around 800 start-ups and realized 200 successful exits. HTGF has over €2 billion in fund volume.
The fund investors in this public-private partnership include the Federal Ministry for Economic Affairs and Energy, KfW Capital as well as 45 companies and family offices.
Further information is available at HTGF.de or on LinkedIn.

Media contact
High-Tech Gründerfonds Management GmbH            
Tobias Jacob, Senior Marketing & Communications Manager      
T: +49 228 – 82300 – 121
t.jacob@htgf.de