Sustainability assessment of biogas production from buffalo grass and dung: biogas purification and bio-fertilizer

Biomass from wetland aquatic grass and buffalo grass can be exploited for biogas production, because this substrate is plenteous and does not compete with food production. In this study, the grass substrate was physically pretreated by boiling with different retention time to increase its biodegradability and was examined in batch mode. Boiling pretreatment suggested that 100 °C with 2 h retention time was the best condition. The results showed that the optimum grass concentration in the 1:1 ratio of co-digestion mixture with manure produced the highest methane yield. The results suggested that co-digestion of buffalo grass and buffalo dung was a promising approach for improving biogas production. This study was achieved the upgraded biogas through biological purification contained 90.42% CH4 8.04% CO2 1.43% O2 and 0.11% other trace gases-a remarkable performance based on an efficiency criteria. Furthermore, the digestate has high nutrient concentrations that can potentially use as fertilizer.