Ultrasound-assisted production of biodiesel from soybean oil using Brønsted acidic ionic liquid as catalyst.

Biodiesel production from soybean oil with methanol was performed in the presence of a Brønsted acidic ionic liquid-based catalyst under ultrasound irradiation. The influences of various parameters on the transesterification reaction, including the amount of catalyst, the molar ratio of methanol to oil, the temperature and the ultrasound power, were investigated. The optimal conditions were: methanol/oil molar ratio of 9:1, 1.0 wt.% catalyst in oil, ultrasound power of 200 W, and reaction temperature of 60°C. Under these conditions, the conversion of triglycerides to fatty acid methyl esters was about 93.2% within the reaction time of 60 min.