CO2 capture by mineral carbonation of construction and industrial wastes

The construction sector is one of the main contributors to CO2 emissions, with around 10 Gt of CO2 emitted in 2021. Moreover, it is also a large contributor to waste streams, amounting to 37.1% of the total European waste in 2020. To reduce the sector's environmental impact, this chapter addresses CO2 capture by mineral carbonation using construction and demolition waste (C and DW). This process leads to a double contribution to the circular economy by combining two waste streams (CO2 and C and DW), resulting in valuable materials such as recycled concrete aggregates (RCA) with improved properties and other fillers that can be reused in the construction sector. In this chapter, the main mineral raw materials used in the construction sector are described and the process of mineral carbonation is explained, with a focus on C and DW. The phenomena involved in this process are described and the influences of operating parameters such as water-to-cement ratio, relative humidity, pH, temperature, and CO2 concentration are reviewed.