Optimization of Biogas Production in a Batch Laboratory Mesophilic Temperature

Abstract

Optimization 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 0.15m‘. 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 -’i3.41°(‘/. 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 in‘ of biogas per tn‘ of digester volume per day, mi‘/mid) was achieved at a level of 8% total solids. a temperature of 43.41°C, and a substrate retention time of 15 days.