Parametric study of the alkali catalyzed transesterification of waste frying oil for Biodiesel production

Waste frying oil (WFO) conversion to Biodiesel (Biodiesel) by Alkali-catalyzed transesterification was studied. The effect of operating and processing variables e.g. reaction temperature, MeOH/oil ratio, type of catalyst used and its concentration was investigated at different reaction times. Further, the physical and chemical properties of the WFO and the produced methyl ester (Biodiesel) were measured. Results showed that (within the range of variables studied) the optimum conditions for Biodiesel manufacturing were MeOH/oil ratio 0.4 v/v (corresponds to 9.5 M ratio), with 1.0% (% w/v) KOH (corresponds to 0.83% w/w), temperature of 50 °C and reaction time between 20 and 40 min. Under these conditions, the obtained Biodiesel yield was approximately 98%. Results also showed that the viscosity of the obtained Biodiesel was 5.86 mm2/s which is close to that of petrodiesel with an average decrease of 69.5% in comparison with WFO. Furthermore, the iodine value (25.36 g I2/100 g sample) and the density (0.877 g/cm3) of the Biodiesel met the values specified by JUS EN14214.