Biogas Production from Plantain and Yam Peels: Modelling using Response Surface Methodology

Abstract

The world’s growing demand for energy and our concern to preserve the environment have prompted research into alternative sources of energy. Renewable energy from biomass is one such opportunity. The aim of this study is to model the production of biogas from the anaerobic digestion of plantain and yam peelings and cattle dung. A characterisation of these residues showed their good suitability for methanisation with good moisture contents (˃70%), high volatile solids contents (˃75%) and C/N ratios of between 20 and 30. In addition, methanisation trials under mesophilic conditions following a mixing plan generated quantities of biogas ranging from 128 to 565 mL with CH4 contents of between 54.03 and 72.98%. The digester made up of 1/6 plantain peels + 2/3 yam peels + 1/6 cattle dung gave the best biogas yield with 565 mL for 67.52% CH4. The model established from these results is highly significant with an F value (1268.01) having a probability significantly lower than 0.05. In addition to the coefficients R2 (0.9994) and R2 (0.9986) which adjust are very close to unity, there is a good correlation between the experimental results and those predicted. This prediction model is therefore reliable for explaining biogas production. However, further study of the kinetics of anaerobic digestion and biogas treatment remains important.