From Orange Waste to Biocomposite: Environmental Assessment of Orange-Peel Reinforced PHA Material

Abstract

The growing accumulation of fossil-based plastic waste and the underutilization of organic residues from the agri-food sector highlight the need for alternative, low-impact material solutions. Polyhydroxyalkanoates (PHAs) represent a promising family of bio-based and biodegradable polymers; however, their large-scale deployment is still limited by economic and environmental constraints, strongly influenced by feedstock selection and processing requirements. In Mediterranean regions, orange peel waste (OPW) generated in large quantities by the citrus-processing industry may represent a valuable renewable input for the development of PHA-based biocomposites. In this study, a Life Cycle Assessment (LCA) was performed to evaluate a PHA-based composite reinforced with OPW, following established LCA principles and focusing on a residue-based valorization pathway. The analysis includes the collection and pre-treatment of OPW, PHA production from different feedstock matrices, composite manufacturing, and relevant downstream processing stages. The study aims to quantify the environmental implications of integrating OPW into PHA matrices, identify key hotspots, and support evidence-based material design within circular economy strategies. In addition, it assesses the feasibility of producing a PHA–OPW filament suitable for market-ready applications, developed in collaboration with Krill Design®.