Converting fruit waste into biogas: a waste to energy strategy for urban markets in Ibadan, South-West Nigeria

Abstract

This study aimed at producing biogas, an alternative source of energy, from selected fruit wastes generated in markets in Ibadan, Nigeria. Slurries of five varieties of fruit waste viz: orange slurry (OS), pineapple slurry (PS), watermelon slurry (WMS), banana slurry (BS) and tomato slurry (TMS) were fed into 1 m3 biogas digester in batches and monitored for their biogas yield potentials. Physicochemical analyses of the fruits, feedstock slurries and spent slurries were carried using standard methods. The TMS had the highest potential of biogas generation (6.52 ± 0.03 m3) followed by PS (5.52 ± 0.03 m3), BS (4.43 ± 0.04 m3), WMS (3.79 ± 0.04 m3) and OS (3.39 ± 0.04 m3). There was a very strong positive correlation between CH4 concentration and C/N ratio (r = 0.598, p < 0.05) and VS (r = 0.48, p > 0.05) of all the slurries. Hence, sustainable management of fruit waste could be achieved through conversion to bioenergy which can benefit the waste generators in the markets.