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Bite-Size Climate Tech · Season 5 · E11
Can CO₂ Become a New Cement Ingredient? | Co-reactive
The replacement for the replacement: a new supplementary cementitious material.
Recorded 3 September 2026.
About this episode
Cement producers already use materials such as fly ash and blast-furnace slag to replace some clinker in their recipes. But as the industries supplying these materials change, what happens when those alternatives become harder to find?
Dr Andreas Bremen, CEO & Co-Founder of Co-reactive, joins Lydia Chen to explain how his team is developing a new supplementary cementitious material using minerals, water and CO₂.
We explore what happens inside Co-reactive's tubular reactor, why accelerating mineralisation matters, what the company's demonstration-stage work was showing at the time of recording, and why creating a useful product is central to the commercial case.
For the 8-Year-Old Challenge, Andreas explains the technology through a surprisingly memorable image: a fizzy rocky milkshake travelling through an extra-long straw.
The conversation also covers water recycling, the challenges of industrial adoption and an unexpected personal connection between Andreas and Lydia involving Colombia in 2017.
Key takeaways
- Why the cement industry needs alternatives to conventional supplementary materials.
- How mineral feedstocks, CO₂ and water can react to create a cementitious ingredient.
- Why reaction speed and product performance matter for industrial scale.
- What Co-reactive had demonstrated and what remained to be validated.
- Why turning CO₂ into something useful may offer a different commercial proposition from storage alone.
Guest
Dr Andreas Bremen
CEO & Co-Founder, Co-reactive
Listen and watch
Recorded 3 September 2026. Technology milestones and future plans reflect the discussion at that time. Selected CLI animations are conceptual explanations rather than literal representations of Co-reactive's industrial equipment. Co-reactive is developing a supplementary cementitious material, not finished cement. Demonstration trials are not continuous commercial production. Bite-Size Climate Tech is an independent editorial series, not sponsored promotional coverage.