5 Things to Know About Carbonation

The solution that Carbon8 offers to industry is based on mineralisation and carbonation. The foundations of this technology rests on over 25 years of research by our Scientists & Engineers. What is this reaction and what could it mean for addressing some of industry’s biggest challenges?

1. Carbonation is one of nature’s ways of sequestering carbon

Mineralisation and carbonation occur in nature when Calcium and Magnesium are exposed to CO₂. In natural atmospheric conditions this reaction, albeit continuous, is extremely slow. Examples of where this can be seen clearly is in the iconic Cliffs of Dover, where the exposed white limestone rocks shows where this has taken place millions of years ago.

2. Recognised means of permanent and safe CO2 storage

In the carbonation reaction, the chemical composition of the CO₂ changes and forms carbonates. In its most basic form, this can be represented in the equation below.

CaO + CO₂ → CaCO₃

Ca(OH)₂ + CO₂ → CaCO₃ + H₂O

This demonstrates that it is a permanent and safe form of Carbon, Capture, Utilisation and Storage (CCUS) as this CO₂ can’t be released back into the atmosphere

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3. Exothermic reaction, releasing more energy than it consumes

 Carbonation is an exothermic reaction, when the CO₂ changes to carbonate it is in a more stable state and energy is released. This means the carbonation reaction generates energy rather than requiring it. This is significant as it represents the only energy efficient CCUS solution.

4. Recognised by the GCCA as one of the routes to NetZero

 The potential of carbonation and recarbonation of concrete is already being acknowledged by industry bodies. In the Global Cement and Concrete Association’s (GCCA’s) roadmap to NetZero by 2050, they specifically acknowledged the importance of carbonation and it lists six steps towards NetZero, five of which involve carbonation.  

5. 52% of the world’s carbon is stored in carbonate rock

The significance of carbonation lies in that CO₂ is locked away for millions of years as limestone.  Accelerated Carbonation Technology (ACT) is able to control, manage and accelerate this process to become a real and ready carbon capture solution, transforming waste carbon and residues into new materials.