Parametric Evaluation of Biogas Production from Sawdust and Treated Human Faeces: Optimal Custom Design Approach

Abstract

As energy demand is increasing astronomically, fossil-based fuels became scarce and more expensive, and carbon dioxide emission levels became of greater concern. Thus, the need to convert the co-digestion of sawdust and treated human faeces to produce biogas, a carbon-neutral gas to replace fossil fuels. From the outcome, the logistic function model performance was satisfactory in the simulation of the experimental process. The codigestion of sawdust and human faeces at 2.5 kg each produced the highest biogas output of 5.43 L using Optimal (Custom) Design of Mixture approach but the human faeces alone gave a better biogas quality. Additionally, the high coefficient of determination (R2) ranging between 0.9959 - 0.9879 and standard deviation of 0.023 - 0.321 for temperature - biogas yield respectively, fall within an ideal range. Thus, the model proved to be a useful tool in predicting anaerobic digestion and biogas production processes. Furthermore, the FTIR analysis of sawdust and human faeces indicates their potential to produce biogas if subjected to anaerobic environment. In addition, the GCMS analyzed the % of methane to be 58.40% which is within accepted range. The biogas was tested with a locally fabricated gas burner for flammability and it ignited with a blue flame. Thus, this experiment can be translated to an industrial scale biogas production for cooking and electricity to boost local economy and alleviate poverty.