Process-Level Life-Cycle Assessment of Representative CEM II/A-L 42.5 R Cement: Environmental Hotspots and Decarbonisation Priorities

Cement manufacturing has a substantial environmental footprint driven by clinker production, calcination and thermal energy demand, yet many life-cycle assessment (LCA) studies report only aggregated results that offer limited guidance for process improvement. This study presents a cradle-to-gate, process-level LCA of CEM II/A-L 42.5 R cement, based on a cement composition representative of regional production practices and process data reflecting industrial manufacturing conditions. The production system was disaggregated into ten foreground processes, and impacts per tonne of cement were quantified with ReCiPe Midpoint (H) v1.11 in SimaPro. Inventory data were tiered by quality and reconciled against total results. Climate change was 772.2 kg CO2-eq per tonne of cement, to which the rotary kiln contributed 67.7%, preheating and partial calcination 15.5%, and cement grinding 8.6%, together about 92%. Hotspots differed among the 17 interpreted midpoint categories (water depletion was excluded as a background-data artefact): the kiln led in eight, fuel preparation in five and cement grinding in four, including 97.8% of metal depletion, a result attributed to background datasets that requires verification. The climate change result had an estimated uncertainty of about ±11% (one standard deviation), reflecting the assigned data quality uncertainty and representing a lower bound on total uncertainty. The contribution-based ±30% sensitivity analysis showed that the total result was most responsive to changes in the kiln’s assigned contribution, but did not independently test the underlying inventory assumptions. Kiln thermal optimisation, alternative fuels, clinker-ratio reduction and grinding electricity emerged as potential improvement priorities, while single-indicator assessment risks overlooking category-specific hotspots.