A paint made using residue from cement recycling can sequester carbon from the air
Spotted: Here’s a new way to sequester carbon while beautifying your home or other building: paint made from concrete. Celour paint was developed by Royal College of Art and Imperial College London graduate Kukborg Kim, who created the paint using waste concrete powder. This is a cement-based residue comprised of calcium oxide, which is leftover from concrete recycling.
The cement residue is normally buried in landfills, where it can leach into the soil and turn it alkaline, consequently damaging the local environment. However, when mixed into paint, the powder can undergo mineral carbonation. This is the formation of stable carbonates by the reaction of CO2 with minerals in the cement. The carbonation process effectively sequesters carbon in the air and has been used in a number of other CO2 sequestration projects.
To create the indoor-outdoor paint, Kim filters the powder, pulverises and mixes it with a polyvinyl alcohol binder, water and various pigments. Once applied to a wall, Kim claims that the paint is capable of sequestering 27 grams of CO2 for every 135 grams of paint used. Kim also claims that the paint could allow carbon to be locked away almost indefinitely unless exposed to extreme heat.
On her website, Kim writes that “By using Celour, we can not only actively capture CO2 in the air but also decrease the carbon emission occurring while making new cement. Celour will be the initial step in restoring pre-industrial atmospheric levels by the users.”
It is estimated that the cement industry contributes as much as seven per cent of global anthropogenic CO2 emissions – a huge amount. This realisation has led to a number of innovations aimed at reducing this figure. Springwise has recently covered some of the ways of tackling this, including a hydrogen-powered cement production process and concrete made from waste vegetables instead of cement.
Written By: Lisa Magloff