Anaerobic Co-digestion with different concentrations of whey and cow dung in biogas production

Abstract

In this research, the whey potential for optimization of biogas production by anaerobic codigestion with cow dung was studied. It used a two-component multifactorialdesign, where it was studied four batch typebiodigesters of 4 liters on a laboratory scale with different whey concentrations (0%, 10%, 30%, 50%) and dilute cow dung in relation 1:1.5, each one in three replications. The experimentation was performed under temperature control of 35°C±2°C; and pH control between 6.4 to 6.9 by the addition of NaOH 3N; with an average of 7% of total solids and a holding time of 35 days. Below these conditions, the 2 nd biodigester with 10% of whey, it was the one which generate the largest amount of biogas with 37.9 liters in total; the 3 rd biodigester, with 30% of whey generates 24.2 liters of biogas;and the 4 th biodigester, with 50% of whey generates 14.5 liters. The reduction of total solids in biodigesters were 38.5%, 43.4%, 40.2% and 27.6% respectively. We used the Gompertz model, which allowed us to find high correlation grades oscillating between 86.295% y 94.268%. Therefore, it can be established, that the use of whey duplicates the biogas production until 52% and sets a limit of 30% (v/v) to obtain a good biogas production in batch-type biodigesters.