Comparison and modelling of Biogas production from unpeeled and peeled cassava tubers at a mesophilic temperature

Abstract

The production of energy from biomass such as an energy crop is gaining momentum due to the steady increase of the world population, economic growth and the accelerating cost of fossil fuels. In recent years, progressive climate change related to global warming and rampant Green House Gases emissions necessitates applied research in renewable energy generation from different sources. The purpose of this study, therefore, was to evaluate the potential of production of biogas from unpeeled and peeled cassava laboratory scale biogas digester, with cow dung (inoculum) as source of methanogens. The experimental design consists of two biomass raw materials (i.e. whole cassava and peeled whole cassava tuber) L/kg VS was obtained from peeled cassava tuber anaerobic fermentation using inoculum followed by the digestion of peeled cassava tuber as raw material without inoculum which led to the production of 493.35 L/kg VS. The cassava with inoculum, produced 28.75% more gas yield when compared to peeled cassava without inoculum. The Modified Gompertz model fitted the cumulative experimental methane gas data well. The model with the newly developed coefficient was used to predicate the maximum biogas yield at day 40. The validated results show that peeling the cassava tuber increase the biogas yield by 38% compared to the unpeeled tuber.