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.

Technology

Founded in 2024, Co-reactive develops a continuous CO₂ mineralization 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.

Goals

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 mineralize biogenic or process-related CO₂ streams directly at cement and steel production sites.

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 Rarità of conventional cement substitutes due to the coal phase-out and structural changes in the steel industry.