Integrated Policy for Bio-Energy Production: the Apulia Region

The present work represents an innovative attempt to give a solution to the double necessity of seeking for new energy sources, and avoiding the disposal of the most abundant wastes from agricultural and food activities in the Apulia region in order to preserve the environment.In particular olive pomaces, olive mill wastewaters and whey milk have a high organic content (100 g/l, 60 g/l and 60 g/l respectively), they are acid (pH between 3,5 – 5,5), total solid percentage concentrations of 30%, <5% and 5% respectively. These chemical characteristics make these wastes potential sources of contamination for the land and aquifers, but also an interesting feedstock for biogas production through anaerobic digestion process.This work includes two experimental campaigns, both conducted at Asja Ambiente’s research centre in Ceglie Messapica (Italy). In the first one, different waste-mixtures, obtained from olive pomace, olive mill wastewaters and whey milk, were feeded in a 45 liters anaerobic reactor in order to evaluate their biogas yields. The best feed mixture was the combination of olive pomace at 25% w/w concentration with whey milk, with a daily biogas production of about 40 liters, approximately 0,75 liters of biogas per liter of reactor.The second experimental campaign was carried out using the above combination of whey milk and olive pomace has the main feed mixture in a anaerobic pilot plant of 1.8 m3 of volume. The duration of campaign was of 75 days and, after a period of acclimatization of the biomass to the substrates charged in the reactor, lead to a stable daily biogas production of about 2000 liters (approximately 1,1 liter of biogas per liter of reactor), with a methane concentration in the range 65-70% w/w.