Evaluation of the Potential use of Bagasse and Sugar Millswaste Water as Substrate for Biogas Production

Biogas is a sustainable alternative source of energy to fossil fuels. Its production also serves as sink for biological wastes and it is a pollution control measure. Most of biogas generation units in Kenya utilize animal wastes as the substrate. However, the bio fuel potential of bagasse, the abundant crop residues like co-products in sugarcane-based industries remain underutilized. The idea of converting bagasse into additional energy is gaining attention, especially through government commitments on increasing the renewable energy generation combined with the reduction of carbon dioxide emissions. In this study bagasse samples collected from Chemelil sugar mills were passed through multiple sieves of different sizes to obtain different particle sizes. Mills waste water was also collected from Chemelil sugar factory and analyzed for pH and Total Dissolved Solids (TDS) to establish their biogas production potential, the analyzed mills waste water was then mixed with different particle sizes of bagasse and allowed to be digested anaerobically. Volume of the gas collected from each flask containing different particle sizes of bagasse was measured to identify the optimum conditions for biogas production. The study showed that the mills waste water that had the highest TDS (130g/L) yielded relatively higher volumes of biogas when mixed with bagasse of different particle sizes. Bagasse of particle size ≤0.600mm produced the highest volume when mixed with the mills waste water with TDS and pH of130g/l and 4.67 respectively. Designing and installing a digester system that allows for the control of TDS and pH in mills wastewater and utilizes bagasse of particle size ≤0.600mm would be expected to produce reasonable amount of biofuel and put a check on environmental pollution problems associated with bagasse and sugar mill waste waters in sugar factories.