Optimization of Biodiesel Production from Used Cooking Oil Using Immobilized Lipase Isolated from Bacillus halotolerans Through Response Surface Methodology

Abstract

The primary goal of this study is to convert waste cooking oil into biodiesel using immobilized lipase enzyme from Bacillus halotolerans. The used cooking oil acid quantity is 3.95 mg KOH/g. In the optimal settings of enzymatic transesterification, methanol:oil ratio 6:1, reaction time 120 min, lipase enzyme concentration 0.6 mg/ml, and temperature 32 °C, the biodiesel yield was 29.64 mg/kg. ANOVA analysis revealed that enzyme concentration and methanol:oil ratios are the two most dominating factors affecting biodiesel yield. The high R2 99.87 and R2 adj 99.56 values indicate that the fitted model agrees with the predicted biodiesel and actual experimental values. Bio-supported beads could preserve up to 76.62 percent of original activity after six cycles of immobilized lipase enzyme reusability testing. Furthermore, the characteristics of biodiesel were assessed and confirmed using the glycerol assay method and FTIR analysis. The proposed technique has the potential to reduce biodiesel production costs and make waste cooking oil disposal easier. Additionally, this study found that the optimization process improves and enhances the process of converting waste cooking oil to biodiesel.