Environmental Benchmarking for Sustainable Clinker Production: A Harmonized Cradle-to-Gate Life Cycle Assessment Using Real Industrial Data

Clinker production is the main contributor to the environmental footprint of cement manufacturing and represents a key target for improving the sustainability of the cement industry. This study presents a harmonized cradle-to-gate life cycle assessment (LCA) of clinker production based on real industrial plant-level data and establishes environmental benchmarks for inter-plant comparison. The framework enables consistent evaluation of environmental performance while minimizing methodological inconsistencies that often limit the comparability of LCA studies. Using a plant-level industrial inventory dataset, key energy and emission indicators were assessed and compared with a literature-based benchmark under harmonized methodological conditions. The case-study plant exhibited a thermal energy intensity of 3162 MJ/t clinker and electricity consumption of 52.23 kWh/t clinker, representing improvements of approximately 6% and 29%, respectively, relative to the benchmark system. However, total direct CO2 emissions remained comparable at 1010 kg CO2/t clinker, indicating that improvements in operational energy efficiency do not necessarily result in proportional reductions in overall greenhouse gas emissions. Process-related emissions from limestone calcination accounted for approximately 73% of total emissions, limiting the mitigation potential achievable through energy efficiency alone. These findings highlight the importance of integrated benchmarking approaches that simultaneously consider energy intensity, emission structure, and climate impact when evaluating clinker production systems and developing decarbonization strategies for the cement industry.