Advances and future perspectives in agricultural waste valorization

Agricultural waste valorization has emerged as a promising strategy to support the circular bioeconomy by reducing waste streams and generating sustainable alternatives to fossil-derived chemicals. In this review, we discuss the valorization of agricultural waste to value-added chemicals, reporting on secondary metabolites extracted from different waste biomasses. Additionally, we focus on extraction techniques and their environmental impacts, as assessed by life cycle assessment (LCA) studies. Finally, we discuss emerging waste biomass sources, including pine needles, wood bark, and poultry manure, along with their valorization processes. Further research is needed to enable their comprehensive valorization through the integration of experimental investigations and robust LCA approaches. Future studies should adopt harmonized methodological frameworks that include product-oriented functional units, comprehensive system boundaries, transparent allocation procedures, and solvent and energy management strategies, alongside scale-up and sensitivity analyses to improve the robustness, comparability, and industrial relevance of sustainability assessments.