The company proved that enforced carbonation of recycled concrete paste (RCP) within the site’s existing wet scrubber allows for a high carbon uptake within less than 30 minutes, preventing emissions from entering the air. During the trial, 15 tons of industrial RCP were fed into the scrubber. The result was 100 kilograms of carbon dioxide being bound within each ton of RCP.
The trial was carried out with the R&D team of Hanson’s parent company Heidelberg Materials. It confirmed that enforced carbonation is feasible, said Sustainability Director Marian Garfield. This discovery supports the circular economy by using waste-recovered concrete fines to remove carbon emissions from the production process while producing a secondary material that can replace virgin limestone in cement and concrete production, she also said.