Plug flow digestors for biogas generation from leaf biomass

The low, family level availability of animal dung in rural Indian families restricts the spread of biogas technology. This has warranted the design and development of novel biogas plants for other biomass feedstocks. The plug-flow digestors discussed in this paper circumvent the problems associated with floating of biomass feedstocks and enable a semi-continuous operation. The long term operation of such biogas plants using a mixed green leaf biomass feedstock is reported along with its design features. Results show that during long term operation, such biogas plants have the ability to produce up to 0.5 m3 gas/m3 reactor/day (ambient conditions) at specific conversion rates ranging between 180 and 360 l biogas/kg TS (total solids) at a 35 day retention time.