Assessment of maize biomass digestibility: Roles of plant age and ensilage duration in biogas generation

Maize residue is considered a significant feedstock for biogas production, especially in regions where it is abundantly cultivated. Maize ensilage undergoes chemical changes during the silage period, which positively impact biogas yield. This study investigates the impact of maize plant age, ensilage period, digestion temperature, substrate characteristics, biogas production, and substrate degradation rate on anaerobic digestion efficiency. Two samples of maize, differing in age by 20 days (Maize silage_{90 days}) and (Maize silage_{110 days}), were ensiled for 100 days, in a batch mode under mesophilic (35°C) and thermophilic (55°C) conditions for 60 days for anaerobic digestion. The results revealed that under thermophilic conditions, biogas production from Maize silage₉₀ was 8.86% higher than from Maize silage₁₁₀, while under mesophilic conditions, Maize silage₉₀ produced 22.86% more biogas than Maize silage₁₁₀. The rate of COD degradation reached 95.99% (Maize silage₉₀) and 93.75% (Maize silage₁₁₀) under thermophilic conditions, while 93.75% (Maize silage₉₀) and 88.94% (Maize silage₁₁₀) under mesophilic conditions. These results indicate that the younger maize plant, combined with appropriate silage and temperature, can substantially enhance biogas yield and substrate degradation, providing a basis for optimizing AD performance.