Application of Electrodialysis for Acid and Alkali Recycling in Indirect Mineral Carbonation

The steel and cement industry contributes approximately 8% and 7% of CO2 emissions worldwide. The project will be built on the concluded EPSRC/UKCCSRC that addresses CO2 sequestration in the steel and cement sectors using the Indirect Mineral Carbonation process. Indirect mineral carbonation is a promising pathway for permanent CO₂ sequestration, converting alkaline earth minerals into stable carbonates. However, its large-scale implementation is hindered by high operational costs and chemical consumption, particularly acids and alkalis used during mineral dissolution and carbonation steps. This research proposes the integration of electrodialysis (ED) technology to recycle and regenerate acids and alkalis within the indirect mineral carbonation process, enhancing its economic and environmental sustainability.

The study will investigate the optimisation of electrodialyzer configurations for selective ion separation and recovery under varying operational conditions (current density, membrane type, flow rate, and feed concentration). Experimental work will evaluate recovery efficiency, energy consumption, membrane stability, and process scalability. A techno-economic and life cycle assessment will be conducted to compare the integrated system with conventional single-use chemical processes.

The expected outcome is the development of a closed-loop carbonation system with reduced chemical input, lower waste generation, and improved energy efficiency. This research aims to advance carbon capture and utilisation technologies, contributing to sustainable industrial decarbonisation and circular chemical processing.