Effects of inoculum to feedstock ratio on anaerobic digestion for biogas production

Abstract

Biogas is considered as a clean and a renewable form of energy that could replace the increasing non-renewable energy sources such as fossil fuel for use in heat production and for electricity generation. The inchoate gain in the shift for a renewable source of energy is that the feedstock is often a by-product, a residue or waste product of other processes without the competition for arable land. In this study, five (5) Laboratory scale biodigesters were used for the anaerobic co-digestion of locally available Miscanthus Fuscus and cow dung, controlled at a pH range of 6.2-7.8 and at a mesophilic temperature of 35 ± 2˚C. Study was also carried out in batch mode at a hydraulic retention time of 33 days. The anaerobic co-digestion process was developed and optimized at varying inoculum to feedstock ratio of 1:0, 0:1, 1:3, 3:1, and 1:1 to determine the potential biogas yield from each proportion. The highest biogas potential was recorded at an inoculum to feedstock ratio of 3:1 with the least biogas potential recorded by the biodigester at a ratio of 0:1.