VALORISATION OF CASSAVA PEEL WASTE THROUGH MICROBIAL FERMENTATION FOR PRODUCTION OF BIOETHANOL AND BIOGAS IN SOUTHWEST NIGERIA

Abstract

The increasing generation of cassava peel waste (CPW) in Southwest Nigeria poses significant environmental challenges while representing an underutilised biomass resource for renewable energy production. This study investigates the valorisation of CPW through microbial fermentation for the dual production of bioethanol and biogas, integrating experimental optimisation with techno-economic and environmental assessments. Cassava peel samples were collected from major processing communities in Oyo, Ogun, and Ondo States and characterised for biochemical composition. Indigenous microbial strains were isolated, identified, and applied in batch fermentation and anaerobic digestion processes. Fermentation parameters were optimised using Response Surface Methodology, while bioethanol and biogas yields were quantified using gas chromatography and volumetric methods, respectively. Results show that CPW contains high levels of fermentable carbohydrates and supports substantial bioethanol and methane yields, with indigenous microbial strains outperforming commercial counterparts. Techno-economic analysis indicated favourable economic viability with a short payback period, while life cycle assessment revealed significant reductions in greenhouse gas emissions and waste volume compared to conventional disposal. The study demonstrates that CPW valorisation offers a sustainable, circular-economy pathway for renewable energy generation and waste management in cassava-producing regions of Nigeria.