Enhancing biogas production from vinasse through optimizing hydraulic retention time and added load using the response surface methodology

Vinasse, a byproduct of ethanol production from sugarcane, is a rich organic matter and poses environmental challenges due to its high pollutant content. Effective biomethane production from vinasse can mitigate its environmental impact by converting organic matter into a useful energy source while reducing its pollutant load. The biomethane production by anaerobic digestion (AD) process of the vinasse byproduct was examined on a laboratory scale. In this regard, several loads from 0.5 to 7 g VS/L were investigated to assess AD performance and methane production. This study investigated how two separate factors, namely the load and hydraulic retention time (HRT), affect both cumulative methane production (CMP) and methane yield (Y_CH4). This investigation utilized a response surface methodology known as the central composite design (RSM-CCD). Statistical analysis of variance (ANOVA) was employed to evaluate the effectiveness of the model generated. Thus, the model's fit, Y_CH4 has a maximum R² value of 0.9759. The results revealed an astounding level of agreement between the experimental data and the proposed model. The RSM results revealed maximum CMP and Y_CH4 values of 409.82 ml and 178.95 ml/g VS respectively, obtained for optimum load values of 2.17 g VS/L and HRT of 15 h. The results emphasize the environmental and economic significance of AD, providing a sustainable waste management solution that helps reduce greenhouse gas emissions and organic pollution. Additionally, it generates valuable biogas and biofertilizers, presenting economic opportunities through renewable energy production and resource recovery. This approach not only alleviates the environmental burden of vinasse but also enhances the economic viability of ethanol production by creating additional revenue streams.