What They Do

Concrete that is stronger and absorbs CO2? C4C is developing a novel technology for carbon sequestration within concrete. The team has developed a range of additive materials that act as carriers for captured CO2. The carrier (loaded with CO2) is mixed with cement in the concrete making process. As the concrete cures, the carrier releases the loaded CO2 in a highly predictable manner which then carbonates within the concrete. The mineralised CO2 is thereby sequestered permanently while strengthening the concrete itself.

Why It Matters

Converting captured CO₂ into long-lasting materials and products is an alternative sequestration avenue (compared with underground injection) with the potential to add value beyond the carbon impact. With its production responsible for 8% of global GHG emissions, concrete is the one man-made material produced at the gigatonne scale that can make an impact on the global carbon balance.

Many routes are being explored for decarbonising concrete - curing with captured CO₂ being one of them. C4C’s approach stands out compared to other potential solutions as no changes are required to concrete supply chains or manufacturing processes. C4C’s CO₂-bearing carriers can be added directly to the cement mix. Alongside sequestering CO₂, the process enhances the concrete’s strength, which in turn reduces the amount of cement needed. A genuine win-win - reducing the emissions from utilising concrete AND sequestering additional CO2 durably

C4C's labs in Nottingham, UK

Testing the strength of C4C's CO2 enhanced concrete