Life cycle assessment of the indirectly heated calcium carbonate looping carbon capture for lime production

Reducing process CO₂ emissions from lime production is essential for decarbonising one of the most carbon‑intensive industries. This study provides the first comprehensive life cycle assessment (LCA) of indirectly heated calcium carbonate looping (IHCaL) applied to lime plants, evaluating five scenarios: a reference plant, two tail‑end IHCaL configurations, and two fully integrated IHCaL configurations, each fuelled by lignite or solid recovered fuel (SRF). Using ReCiPe 2016 midpoint and endpoint methods and a functional unit of 1 kg of lime, environmental impacts were quantified across 18 categories and assessed using Monte Carlo uncertainty analysis (10,000 iterations). All IHCaL scenarios substantially reduce global warming impact relative to the reference case, with reductions exceeding 80%. SRF‑fuelled systems achieve net‑negative mean global warming impact due to avoided landfill burdens, and tail-end configurations further benefited from electricity export. However, lignite‑fuelled IHCaL scenarios increase freshwater and marine ecotoxicity, freshwater eutrophication, and human carcinogenic toxicity, driven mainly by upstream lignite mining. SRF‑fuelled scenarios avoid these burdens but have higher mineral and fossil resource scarcity impacts related to natural gas use in SRF processing. IHCaL offers a strong route to decarbonisation of lime production, provided fuel supply chains are carefully managed. The findings show SRF as the environmentally preferred fuel and underscore the importance of upstream process optimisation and region‑specific electricity modelling.