Predicting kinetic model of biogas production and biodegradability organic materials: Biogas production from vinasse at variation of COD/N ratio

The biogas fermentation of vinasse (TS 7.015 ± 0.007%) was investigated within a wide range of COD (Chemical Oxygen Demand)/N (Total Nitrogen) ratio. Urea (46% nitrogen content) was added into substrate to adjust COD/N ratio of 400/7–700/7. This study used batch anaerobic digesters in laboratory-scale that were operated at room temperature in 60 days. The results showed that control variable, 400/7, 500/7, 600/7, 700/7 generated total biogas of 107.45, 123.87, 133.82, 139.17, 113.27 mL/g COD and had the value of COD removal of 31.274 ± 0.887, 33.483 ± 0.266, 36.573 ± 1.689, 38.088 ± 0.872, 32.714 ± 0.881%, respectively. Variable with COD/N ratio of 600/7 was the best variable. In the kinetic model of biogas production, variable with COD/N of 600/7 had kinetic constant of A (mL/g COD), μ (mL/g COD.day), λ (days) of 132.580, 15.200, 0.213, respectively. The model equation of kinetic of biodegradability organic materials obtained was C ( t ) = Co - exp - exp μ e A ( λ - t ) + 1 ∗ Co + Ce .