Abstract
The aim of this work was to produce biodiesel from waste vegetable oil over ZnO/TiO2 catalysts as well as investigating the effect of co-solvent (hexane), reaction temperature and time on waste vegetable oil conversion to biodiesel. Production of biodiesel from virgin oil is still a downfall in commercial processes due to high cost. Thus, the process of producing biodiesel from waste vegetable oil over a TiO2-supported ZnO catalyst was studied in the absence and the presence of hexane as co-solvent respectively. The conversion of waste vegetable oil was found to increase with temperature and reaction time. The highest conversion that has been achieved was 99.1% at a temperature of 200 °C after 15 min of reaction for the reaction using hexane as co-solvent. The use of hexane as co-solvent was found to increase the oil conversion at lower reaction temperature and no effect was observed at higher temperatures.