Biogas production by the anaerobic digestion of whey

Abstract

Digestion is an attractive alternative in the treatment of waste generated in the agricultural industry, as it treats waste and also produces biogas that can be used in power generation, resulting in both environmental and economic benefits. This study presents the results of anaerobic digestion of cheese whey using swine wastewater as inoculum. Digestion was performed using sequencing batch bioreactors with a total volume of 2.350 mL. In order to evaluate digester efficiency, biogas was collected in a gas meter. Methane concentration in the biogas was determined using a biogas analysis kit, by AlfaKit®. The project was carried out using two different temperatures, which were 32ºC and 26ºC, that resulted in the production of 270 and 171 L (kg-sv)^-1 of biogas, respectively and a reduction of over 40% in volatile solids in both treatments. The tests show that there is a good potential for the use of whey in the production of biogas and its further conversion into energy.