Biogas Potential Assessment of Co-digestion of Various Wastes (Cassava Residues, Poultry Droppings and Household Waste) in the Gbêkê Region, Bouaké, Central Ivory Coast

Abstract

Assessing the potential for biogas from cassava residues, poultry droppings and household waste in Bouaké will help determine the viability of a sustainable energy project. Cassava is abundant in this region, and its exploitation produces starch-rich residues, a potential source of biogas through anaerobic digestion. Poultry droppings from livestock farming and household waste are respectively sources of biomass rich in nitrogen and various organic materials. Unfortunately, poor management of these wastes leads to environmental problems, including foul odors that encourage disease, and soil and groundwater pollution. It is therefore necessary to quantify this waste with a view to transforming it into renewable energy. To do this, we began by collecting cassava residues and household waste from attiéké production cooperatives and some restaurants, and poultry droppings from city farms. After collection, we sorted and mixed the different types of waste with water, then filled the digesters. And finally, we made different formulations from these wastes for biogas production. During the process, the results obtained from the physico-chemical characteristics of the waste give respectively for pH 6.4 and 7.4, for BOD5 25 442 mg/L and 19 475 mg/L, for COD 74 400 mg/L and 62 100 mg/L, for MES 3 733 mg/L and 2 675 mg/L, for MS 11.6% and 8.1%, for VDM 64.3% and 58.2%. Concerning biogas composition and production, methane is estimated at 56.5% on average, with a standard deviation of 6.1, giving a biogas volume of 3.2 m3. These results provide valuable indications for the planning and development of biogas production facilities in Bouaké. They encourage the adoption of renewable energies, waste reduction and better management of organic residues, thus contributing to the environmental and economic sustainability of the region.