Exploring the potential of distillery vinasses through upcycling: Pathways to a circular economy

Distillery production, particularly for bioethanol and alcoholic beverages, generates substantial quantities of liquid waste known as vinasses. Typically, 10-15 liters of vinasses are produced for every liter of distilled product. This poses significant environmental challenges, including eutrophication and soil pollution. To address these issues, this systematic review comprehensively evaluates various valorization pathways for distillery vinasses management. The review analyzed 72 treatments involving vinasses from the ethanol industry, alcoholic beverage production, and their combinations with agro-industrial residues. These treatments were categorized into three major valorization pathways: waste-to-energy, waste-to-food, and waste-to-product. While the characteristics of the produced products were found to be independent of the substrate used, biotechnological treatments, such as two-stage anaerobic digestion and fungal anaerobic fermentation, demonstrated superior product yield and diversity. Fungal-based treatments stood out as the most effective, particularly for their ability to process complex substrates and enhance the production of high-value products. Furthermore, the production of polymers and enzymes using bacteria highlighted the potential for generating secondary high-value-added products from primary valorization processes, creating additional economic opportunities. Despite these promising findings, the lack of specific and comprehensive regulations addressing vinasses treatment and valorization remains a significant challenge. Moreover, tools like life cycle assessment (LCA) and techno-economic analysis, essential for ensuring sustainable and practical solutions, remain underused in this area.