Optimization of process parameters for the economical generation of biogas from raw vegetable wastes under the positive influence of plastic materials using response surface methodology

In this experimental study, optimization of selected process parameters were assessed as controlling factors for the efficient generation of biogas by Response Surface Methodology (RSM) using raw vegetable wastes (RVW) and waste plastics (WAP) as the key constituents. The four factors: WAP, height to diameter (h/D) ratio, water content (WAC) and digestion time (DT) on weekly basis were optimized by RSM using rotatable central composite design (RCCD) to determine their optimum level. Considering various experimental data, the optimized result showed that enhanced biogas production (25.25 m3/ton of RVW) was achieved with WAP (15%), h/D ratio (35), WAC (162 ml), and DT (18 week). A correlation coefficient (R2) of 0.9976 indicated high degree of correlation between the variables.