Ionic liquids-catalyzed transesterification of soybean oil under ultrasound irradiation

The ionic liquid-catalyzed transesterification of soybean oil with short-chain alcohols by using ultrasound (24kHz, 80W) was studied. We found that, at 60°C under ultrasonic irradiation and a molar ratio of 14:1 methanol/oil, a biodiesel yield in excess of 96% can be achieved in a remarkably short time duration of 20 min or less in comparison to 5h or more using conventional method. Therefore, this method was proved to be efficient and time saving for the preparation of biodiesel by transesterification of soybean oil. In addition, the ionic liquid had a good reusability and can be easily separated from the biodiesel by simple decantation.