Energy-optimised cryogenic CO2 capture for cement production decarbonisation: process design and techno-economic analysis

• Cryogenic CO 2 capture in cement plant assessed at 90% and 95% capture rates. • Optimised refrigeration loop conditions to minimise process energy demand. • Refrigerant compression accounts for 75% of overall energy demand and 50% of CAPEX. • Nearly constant energy penalty (1.19-1.21 MJ el /kg CO 2 ) between 90% and 95% capture. • CO 2 avoided cost estimated at 127-128 €/t CO 2 for both cases under an EU energy mix. Achieving net-zero emissions in the cement sector requires the development of effective carbon capture technologies to address process-related emissions from limestone calcination. While much of the current research and applications focus on more conventional methods such as chemical absorption and oxyfuel, cryogenic CO 2 capture offers potential advantages in energy efficiency, capture rate, and product purity, though it remains underexplored at an industrial scale. This study presents a comprehensive assessment of cryogenic CO 2 capture for cement applications in the EU, including thermodynamic modelling, process design and optimisation, and techno-economic analysis. Two process configurations targeting 90% and 95% capture at 99.9% mass CO 2 purity are benchmarked. The 90% capture design achieves an energy penalty of 1.19 MJ el /kg CO 2 , corresponding to a threefold increase in electricity consumption compared to an unabated cement plant. Sensitivity analysis demonstrates consistent energy performance across a 17-28% mol range of flue gas compositions. Increasing the capture rate from 90% to 95% maintains the energy penalty nearly constant (1.19-1.21 MJ el /kg CO 2 ), with only marginal economic impact. At 95% capture, the incremental cost of clinker production rises by 5% compared to 90% capture, while the higher CO 2 avoidance yields a similar cost of avoided CO 2 (127-128 €/t CO 2 ). From an economic perspective, cryogenic capture significantly outperforms conventional MEA-based capture, while remaining slightly less competitive than oxyfuel and calcium looping under current EU energy mix conditions. Overall, cryogenic capture emerges as an energy-efficient and economically viable post-combustion option for cement industry decarbonisation, with the added benefit of delivering a high-purity CO 2 stream suitable for storage or utilisation.