An Innovative Small Sized Anaerobic Digester Integrated in Historic Building

Abstract

The CRB - Biomass Research Centre of the University of Perugia has developed an innovative anaerobic batch plant for the biogas production consisting on polyethylene bags, conventionally used for agriculture silage storage, converted and used as anaerobic digesters. Bags equipped with piping systems, become biocells: hence the name of the plant, biocells biogas plant.The biocells, filled with biomass residues and manure, allow the disposal of residual agricultural biomass and manure, with a reduced cost for plant and a quick return on investment, thanks to the incentives for electric production from renewable sources, particularly advantageous for small biogas plants, according to the last Ministry Decree.The tests carried out on the biocells system detected the critical issues in order to implement a new prototype of a small size plant, more flexible and adaptable to other contexts different than the rural one.Unlike previous systems that worked for farms, the new plant will be integrated into a civil building: the stables of the Fortress of Saint Apollinare, located in the municipality of Marsciano (PG), currently under renovation in order to create an office structure at service of the fortress, that will be rehabilitated to host a research and education centre, with classrooms, dining areas, offices, rooms and canteen.The plant will be fed by waste from the canteen residues and the pruning or residual biomass from the maintenance of the green and the neighbouring municipal wastewater from the septic tank. The thermal production is partially absorbed to maintain the temperature for the biological reactions in the digester; electrical energy is injected into the grid to take advantage of incentives from renewable sources.