Life cycle assessment and eco-efficiency of biorefineries and conventional management strategies for agro-industrial residues

Several strategies for valorizing agro-industrial residues, such as potato peel (PP), have been explored through both stand-alone processes and integrated biorefinery approaches. However, life cycle impact assessment (LCA) has not been fully utilized as a decision-support tool for identifying the most environmentally sustainable management route. Thus, this study aims to compare four distinct scenarios for the valorization of industrial PP using LCA within a European context. Scenarios A and B represent two biorefinery configurations: Sc_A – involves anaerobic digestion integrated with a combined heat and power (CHP) unit followed by composting; Sc_B – consists of solid-liquid extraction followed by anaerobic digestion with a CHP unit and composting; In contrast, Scenarios Sc_C and Sc_D correspond to stand-alone approaches, with Sc_C involving composting unit and Sc_D comprising landfill disposal. The LCA was carried out using the ReCiPe methodology, with a functional unit defined as the valorization of 1 Mg of PP on a wet basis. Among the scenarios, Sc_B exhibited the highest environmental burden across all midpoint and endpoint categories, primarily due to the substantial ethanol and heat requirements associated with the extraction process. In contrast, Sc_A and Sc_C demonstrated notable environmental benefits, attributed to the substitution of fossil-derived electricity and inorganic fertilizers (N, P 2 O 5 , and K 2 O) by renewable electricity and compost produced. The eco-efficiency analysis further highlighted that different biorefinery configurations can yield markedly different outcomes: Sc_A emerged as the most eco-efficient strategy, followed by Sc_C and Sc_D, whereas Sc_B showed the poorest performance due to its high environmental and operational costs. • Biorefinery and stand-alone residue management strategies were assessed through LCA; • Solid-liquid extraction showed environmental burdens due to heat and solvent demand; • Generation of electricity and organic fertilizers led to environmental benefits; • Anaerobic digestion followed by composting proved the best overall performance; • Biorefinery and stand-alone processes can achieve comparable eco-efficiency levels;