Multiple feedstocks and decentralized biorefineries as a strategy for a sustainable development approach: A case study

Mixed-feedstock biorefining is promising for producing valuable bioproducts in regions with diffuse and dispersed biomass resources. By combining feedstocks, regions of low-density biomass can achieve economies of scale and lower production costs. Mixed-feedstock biorefining presents several challenges, including biomass handling, optimal plant sizing, bioproduct selectivity, and separation efficiency. Unlike the existing literature, which primarily focuses on single-feedstock and centralized configurations, this study presents a novel process design analysis for mixed-feedstock biorefining through a case study, integrating agro-industrial and forestry residues. Specifically, bioethanol, xylitol, and lignin production from sugarcane bagasse and eucalyptus sawdust are analyzed. Two scenarios are studied with variations in biomass transport distance, plant sizing, biomass handling operations, and product selectivity. Net Present Value (NPV) was used as the economic indicator. For the decentralized configuration (Scenario II), an investment of USD 35.1 million resulted in an NPV of USD 3.2 million. Additionally, transport-related emissions were reduced by 46%, and 40–45 direct jobs could be generated. These results demonstrate that decentralized mixed-feedstock biorefining can enhance economic viability, reduce environmental impacts, and promote rural development through the valorization of multiple waste streams.