Application-Oriented Valorization Routes and Arrangements for Agro-Industrial Residues and By-Products: A Scoping Review Across Sectors and Application Scales

The valorization of agro-industrial residues and by-products can improve resource efficiency and circularity, but implementation depends on more than technical performance. This scoping review mapped application-oriented valorization routes, their distribution across sectors and scales, and the barriers, facilitators, gaps, and recommendations related to implementation. Following Joanna Briggs Institute guidance and PRISMA-ScR, the Web of Science Core Collection was searched without publication-period or language restrictions. Thirty peer-reviewed studies published between 1996 and 2026 were included. Vegetable oils and oilseeds accounted for 40.0% of the studies, while industrial or plant-level applications represented 30.0%. Energy-based strategies were the most frequent (26.7%), followed by biological and chemical or physicochemical approaches (20.0% each). Implementation was influenced by residue characteristics, production processes, infrastructure, costs, logistics, coordination, regulation, and information availability. Six interconnected implementation domains were identified: technical and operational; economic and financial; logistical; organizational and governance; regulatory and institutional; and scale-up, limitations, and recommendations. The findings indicate that scale-up requires integration of technical, operational, logistical, economic, governance, and institutional conditions. An implementation-oriented perspective is provided to support future assessments, industrial planning, and policy decisions toward circular agro-industrial systems.