Life-cycle assessment of concrete production with carbon capture and carbon upcycling process

Abstract

The main CO₂ utilization methods for concrete production, aimed at reducing its carbon footprint, include several promising approaches. These methods include the carbonation of concrete, where CO₂ reacts with calcium hydroxide to form calcium carbonate; CO₂-activated concrete, achieved by infusion of CO₂ into concrete during the mixing or curing process; and carbonation of recycled concrete, which uses industrial byproducts like slag and fly ash to sequester CO₂. Another method is the use of biochar in concrete, where CO₂ is sequestered from organic waste to enhance material properties. More recently, a new method has emerged where CO₂ is used to transform industrial byproducts into enhanced supplementary cementitious materials (SCMs) that are then used to either produce blended cements or used directly in concrete. These techniques not only lower carbon emissions but also have the potential to enhance the strength and durability of concrete, making it even more desirable for construction applications. A significant reduction in the CO₂ intensity of concrete production can be achieved by using post-combustion CO₂ capture processes to capture the CO₂ emissions from the cement production process. A life-cycle assessment (LCA) methodology is crucial to assess and mitigate the environmental impact of concrete. Various decision makers and manufacturers are keenly interested in using an LCA approach to understand and minimize the ecological footprint of concrete.