Accelerated carbonation of different types of construction and demolition waste (CDW)

In this study, accelerated carbonation experiments were performed according to direct aqueous routes on five types of Construction and demolition waste (CDW), with the aim of assessing their potential for CO2 storage. The effect of both water content and residue particle size was evaluated by comparing the extent of carbonation at two liquid to solid ratio (0.4 and 5 l/kg) and two particle dimensions (below 4 and 0.045 mm). At PCO2 = 5 bars and T=25°C, the assessed CO2 storage capacity differed depending on the selected waste stream and was positively influenced by both the water content during carbonation and the specific surface area. A maximum CO2 uptake of 51 kgCO2/ton of CDW was obtained, indicating that it could potentially contribute to the reduction of CO2 emissions, owing to the large quantity of waste produced and available worldwide.