Decarbonising cementitious materials through carbon capture and utilisation (CO24Cem)

Decarbonising concrete production is important since it is directly responsible for ~9% of global CO2 emissions. Academic research in low carbon concrete has overwhelmingly focused on a limited set of supply-side decarbonisation measures, such as carbon capture and storage, broadly overlooking the huge potential of carbon capture and utilisation. CO24Cem will address this knowledge gap and decarbonisation goal by delivering a near-zero CO2 emissions cement produced by carbonating end-of-life concrete with waste CO2. The main scientific aim in CO24Cem is to create this carbonated cement with sufficiently high reactivity so it contains ~0% Portland cement clinker, which is the high-CO2 material produced in cement plants. This aim will be achieved by making breakthrough advancements in cement chemistry and carbonation process technology, which will involve chemical modification of the carbonation reactor feedstock (end-of-life cement paste), optimisation of the carbonation reactor conditions, and the use of novel combinations of materials in its mix design. Success here will create an important pathway to completely decarbonise European cement production and achieve ~100% recycling of non-energy materials in this industry. The breakthrough cement technology will also have excellent use potential globally at the multiple gigaton scale. In CO24Cem, near-zero CO2 emissions concrete products will be produced using this breakthrough technology, accompanied by a life cycle assessment study, to demonstrate its feasibility and the massive potential beneficial impacts. Overall, CO24Cem represents a significant step towards decarbonising the cement and concrete industries, which is one of the most difficult to achieve yet essential aspects of 1.5-2 C temperature rise climate change mitigation targets.