Enhanced Biogas Production from Anaerobic Codigestion of Lignocellulosic Waste for Efficient Bioenergy Utilization in Heating and Combustion Engine

Abstract

Anaerobic digestion (AD) of lignocellulosic agro-waste such as coconut husk fibre, pineapple floret and banana stem was studied using standard protocols. A combination of physical, chemical and biological Pre-treatment was performed to facilitate the anaerobic digestion process. The experiment was carried out using laboratory-scale batch bioreactors maintained at 44.5 ± 2ºC and retention time of 25 days. Biogas production, pH, total and volatile solids concentrations (TS, VS) were also measured. With a general increase in pH after Pre-treatment of all substrates, biogas yield was significantly improved by 83.1% in all codigestion assays when compared to control (untreated substrates) with highest TS and VS removal rates of 77.7% and 87.2% respectively. In terms process performance, Pre-treatment of single substrate did not significantly improve AD of single substrates (coconut husk fibre/pineapple floret) and biogas production was inhibited in pre-treated banana stem. However, the highest biogas production with corresponding TS and VS removal rates of 78.3% and 92.9% respectively were obtained from untreated banana stem. Codigestion significantly enhanced biogas production that can be utilized for heating and knowledge of appropriate Pre-treatment choice is recommended to improve bioenergy production efficiency during anaerobic digestion.