Effects of ultrasonification and mechanical stirring methods for the production of biodiesel from rapeseed oil

This study was conducted to compare the effects of ultrasonic energy and mechanical stirring methods in bio-diesel production from rapeseed oil under base catalysis conditions. With the transesterification of rapeseed oil, the molar ratio of methanol to vegetable oil was 6: 1, and the amount of catalysts added to the vegetable oil was 0. 3, 0. 5 and 1. 0% (wt/wt). The main components of methyl esters from the transesterification of rapeseed oil were oleic acid (48. 5%, C18:1) and linoleic acid (18. 1%, C18:2). In addition, the optimum conditions to produce fatty acid methyl esters (96. 6%) were 0. 5% KOH after 25 min of ultrasonification at 40 °C as compared to mechanical stirring at 60 °C. The maximum conversion ratio was 75. 6% with 1. 0% NaOH after 40 min of ultrasonification at 40 °C. These results indicate that ultrasonic energy could be a valuable tool for transesterification of fatty acids from rapeseed oil in terms of the reaction time and temperature.