Sustainable energy for a winery through biogas production and its utilization: A Chilean case study

The anaerobic digestion of organic residues generated from the wine production process was evaluated. Organic residues namely the stalks, pomace, vine shoots and waste-activated sludge (WAS) from the liquid waste treatment plant and wine lees were used as substrates. A physical and chemical characterization of the solid residues was carried out, demonstrating that the different residues had favorable properties for methane production, although most had acidic characteristics. It was concluded that the highest methane yields (LCH4/kg VS) were achieved in the digesters operating with wine lees and WAS from the aerobic treatment plant with values of 876 +/- 45 and 690 +/- 25 L CH4/kg VS for day 57 of the batch process. By contrast, the wine shoots gave the lowest methane yield achieving values of 93 +/- 5 and 150 +/- 6 L CH4/kg VS on days 30 and 57, respectively. An energy balance was made for the use of biogas in a wine production plant, observing that the amount of biogas generated was sufficient to supply all the necessary energy used by the production plant. An environmental analysis was also carried out focused on the emission of greenhouse gases.