Uncovering the Techno-Economic and Environmental Implications of a Multiproduct Biorefinery from Exhausted Olive...

Biorefineries are pivotal in advancing sustainability, yet most studies remain confined to laboratory scales, lacking comprehensive industrial-level analyses. In this work, the laboratory experiments are scaled up to design and assess the techno-economic and environmental implications of a multiproduct biorefinery system producing antioxidant extracts, lignin, and bioethanol from exhausted olive pomace, a residual biomass from olive oil extraction. Using process simulation and life cycle assessment, five scenarios were evaluated, varying in electricity sources (national mix, solar, wind, or olive biomass) and the heat and cooling sources (fossil natural gas or synthetic natural gas from capture CO₂ and electrolytic hydrogen), with one scenario incorporating a carbon capture and storage (CCS) system. The CCS scenario showed the highest overall costs, 2.5 times higher than the base scenario (27.74 vs 10.99 $/functional unit), primarily due to the additional infrastructure and energy-intensive processes associated with CO₂ utilization and storage. Despite higher costs, it achieved even a negative carbon footprint (-1.05 kg CO₂eq per functional unit cradle-to-gate) and reduced impacts on ecosystem quality, resources, and human health. However, specific impacts like human noncarcinogenic and carcinogenic effects (40% and 60%) and ecotoxicity (up 70%) worsened. Notwithstanding economic barriers and environmental challenges, which can be alleviated by selling carbon credits and tailored policies and strategic decisions, these findings underscore the potential of integrating CCS into biorefinery schemes as a promising pathway to enhance environmental sustainability.