Bio-Energy Generation from Synthetic Winery Wastewaters

Abstract

In Spain, thewinery industry exerts a great influence on the national economy. Proportional to the scale of production, a significant volume of waste is generated, estimated at 2 million tons per year. In this work, a laboratory-scale reactor was used to study the feasibility of the energetic valorization of winery e uents into hydrogen by means of dark fermentation and its subsequent conversion into electrical energy using fuel cells. First, winery wastewater was characterized, identifying and determining the concentration of the main organic substrates contained within it. To achieve this, a syntheticwinery effluentwas prepared according to the composition of thewinerywastewater studied. This e uent was fermented anaerobically at 26 C and pH = 5.0 to produce hydrogen. The acidogenic fermentation generated a gas e uent composed of CO2 and H2, with the percentage of hydrogen being about 55% and the hydrogen yield being about 1.5 L of hydrogen at standard conditions per liter of wastewater fermented. A gas e uent with the same composition was fed into a fuel cell and the electrical current generated was monitored, obtaining a power generation of 1W h Lð€€€1 of winery wastewater. These results indicate that it is feasible to transform winery wastewater into electricity by means of acidogenic fermentation and the subsequent oxidation of the bio-hydrogen generated in a fuel cell.