Co-reactive raises €6.5M seed funding for CO₂-negative materials tech

German climatetech startup Co-reactive has completed a €6.5 million seed financing round led by HTGF, with participation from NRW.Bank, HBG Ventures, AFI Ventures, Evercurious VC, and a group of experienced climate-tech business angels. Additional support is provided through public funding programs, including the Federal Funding for Industry and Climate (BIK) from the German Federal Ministry for Economic Affairs and Energy.

Founded in 2024, Co-reactive develops a continuous CO₂ mineralisation process that converts captured CO₂ and natural minerals, such as olivine or metallurgical slags (EAF & BOF), into CO₂-negative supplementary cementitious materials (SCMs). These materials enable a reduction in clinker content and associated emissions while maintaining or improving compressive strength and durability. The technology is designed as a drop-in solution that can be integrated into existing cement and construction material production processes.

The company collaborates across the value chain with CO₂ and raw material suppliers, cement and concrete producers, and certification bodies to support the transition from pilot facilities to industrial-scale plants in the 100–300 kiloton range.

Through this approach, Co-reactive addresses key challenges in the cement industry, including the high emissions intensity of cement production (responsible for around eight percent of global CO₂ emissions), and the increasing scarcity of conventional cement substitutes due to the coal phase-out and structural changes in the steel industry.

With the seed financing, Co-reactive plans to scale its laboratory and pilot activities to a continuous demonstration plant with a capacity of approximately 1,000 tons per year by Q2 2026.

In parallel, the company is working with industrial partners to prepare first-of-a-kind plants at the tens-of-thousands-of-tons scale, which from 2027 onward are intended to mineralise biogenic or process-related CO₂ streams directly at cement and steel production sites.