Unlocking Sustainable Energy: Nutritional Profiling and Biomethane Potential of Cereal Food Waste for Sustainable Energy Recovery

Cereal food waste represents a significant untapped resource for bioenergy, yet its optimal utilization remains constrained by insufficient data on substrate-specific nutritional profiling and biomethane potential. This study addresses this gap by characterizing the nutrient composition and theoretical biomethane yield of cereal-based food waste in Malumfashi, Nigeria, to evaluate its viability for large-scale energy recovery. Waste samples from local restaurants were analyzed using the Association of Official Analytical Chemists (AOAC) methods for proximate composition (total solids, volatile solids, crude fiber, etc.). Biomethane potential was estimated via the Baserga model, with electrical conversion calculated assuming 35% efficiency. Results revealed high total solids (93.66%) and volatile solids (85.62%), with nitrogen-free extracts (73.75%) dominating the waste profile. The estimated biomethane yield reached 577.3 m³/kgVS (52.3% methane), translating to 1,057 kWh/ton of electricity. This work demonstrates cereal food waste as a high-potential substrate for anaerobic digestion, directly supporting SDG 7 (Affordable Energy) and SDG 12 (Responsible Consumption). Findings provide policymakers with evidence to integrate food waste valorization into renewable energy strategies, particularly in urban settings of developing economies.