Barasa, HenryNyaanga, DavidNjue, MusaMatofari, Joseph2024-02-272024-02-272020-07Barasa, Henry & Nyaanga, David & Njue, Musa & Matofari, Joseph. (2020). Optimization of Biogas Production in a Batch Laboratory Digester Using Total Solids, Substrate Retention Time, and Mesophilic Temperature. International Journal of Power and Energy Research. 4. 10.22606/ijper.2020.42001.https://dx.doi.org/10.22606/ijper.2020.42001https://repository.nrf.go.ke/handle/123456789/593Optimization was done by investigating the interaction effects of total solids, mesophilic temperature, and substrate retention time on biogas production in a batch biodigester. The volume of the biodigester was 0.15m3. Central composite design of Response Surface Methodology was used to design the experiment. Total solid levels were varied from 6.31% to 9.68%, temperature was from 26.59°C to 43.41°C, and substrate retention time was from 9.95 to 20.04 days. Analysis of results was done using Design Expert software statistical package (version 10.0.0.3). It gave a coefficient of determination of 0.9665 which indicated a high correlation between the variables. All the variables had a significant effect. The highest biogas production rate of 75.41litres/day (or 0.50 m3 of biogas per m3 of digester volume per day, m3/m3d) was achieved at a level of 8% total solids, a temperature of 43.41°C, and a substrate retention time of 15 days.enMasinde Muliro University of Science and TechnologyArticle