MPA and its members are always looking for new opportunities to provide innovative solutions that reduce emissions in the manufacturing process or bring new low carbon products to the market.
This project follows on from an MPA BEIS-funded feasibility study in 2019 which found that a combination of 70% biomass, 20% hydrogen and 10% plasma energy could be used to eliminate fossil fuel CO2 emissions from cement manufacturing. Fuel switching is an essential ‘lever for change’ in MPAs UK Concrete and Cement Industry Roadmap to Beyond Net Zero.
Carbonation is a slow process where concrete absorbs CO2 from the atmosphere throughout its lifetime. It is essentially a reversal of the chemical reaction that occurs when cement is produced and CO2 is released from calcium carbonate raw materials when they are heated to volcanic temperatures (these emissions are known as process emissions).
An MPA-led consortium co-funded by Innovate UK, has begun to investigate the potential of new cements containing UK-sourced calcined clays. The project partners will assess the feasibility of producing calcined clays from lower-grade clays, specifically those reclaimed from extraction or other manufacturing processes. Reclaimed clay sources include waste bricks, which do not require heating as they have already undergone thermal treatment, as well as large reserves of overburden clay materials at quarry sites.
Cements for UK concrete applications generally consist of two main components which are usually Portland cement (CEM I) with limited quantities of either fly ash*, GGBS** or limestone powder. The scientific literature has shown that cements can work better if more than two main components are used. In this project, cements with three main components were developed: CEM I-fly ash-limestone powder, and CEM I-ggbs-limestone powder. Not only can cements with more than two components work better in concrete, there is also the opportunity to improve energy efficiency and to reduce embodied carbon vs. single component (CEM I) and two component cements (CEM II and CEM III).