Purification of Residual Glycerol from Biodiesel Production as a Value-Added Raw Material for Glycerolysis of Free Fatty Acids in Waste Cooking Oil

The crude glycerol produced as a byproduct of transesterification synthesis has very few applications because it comprises significant amounts methanol, catalyst, and soap. On the other hand, transesterifications highly acidic oil in presence an alkaline catalyst are problematic due to high free fatty acids. In this study, acid level oil, which was initially determined be 19.25%, decreased permit direct production biodiesel via glycerolysis with pure glycerol, making feasible. Through process purification, refined 92.5% purity. It revealed that physiochemical parameters density, moisture content, ash matter organic non-glycerol pH, Na/K concentrations generated purified equal those commercially available glycerol. contrast, treatment successfully less than 2% under optimal conditions, were 200 °C, glycerol-to-oil molar ratio 4:1, KOH concentration 1.6 wt.% at 350 rpm. inclusion hexane co-solvent accelerated process, weight oil-to-hexane 8:1. Moreover, viable use waste methanol for raw material variety industries, including production. addition, compared esterification, FFA value fell significantly.