Life cycle assessment of three lighthouse cases representing distinct co-processing pathways in China’s cement industry

As a resource- and energy-intensive industry and major source of greenhouse gas emissions, the cement industry is central to China’s carbon peaking and carbon neutrality goals. However, life cycle assessment using generic databases or industry-average inventories may obscure production-line differences. Data collected during 2021–2025 from three representative production lines were evaluated under a harmonized framework. The pathways involved using low-grade limestone and multiple industrial wastes as alternative raw materials and fuels, co-processing heavy metal-contaminated soil, and using municipal solid waste as an alternative fuel. Their integrated environmental load indicators were 16.63%, 17.68%, and 20.42% below the consistent reference scenario, respectively. The largest reductions occurred in abiotic depletion potential, human toxicity potential, and global warming potential, corresponding to resource-conservation, pollution-control, and fuel-substitution pathways. Environmental benefits and burden shifts depended on the substituted function and input properties. These findings provide production-line-level evidence for selecting and optimizing resource-recovery pathways in China’s cement industry.