Ultrasonic-assisted optimization of biodiesel production from Karabi oil using heterogeneous catalyst

Biodiesel as an alternative to fossil fuels has been developed consistently in last few years due to its several advantages such as renewable and biodegradable fuel, reduction of global warming, less air pollution, low sulfur content, low toxic emission, high cetane number, less water and soil pollution, and fewer health risks. In this paper, the effects of methanol-to-oil molar ratio, catalyst amount and reaction time on the transesterification of Karabi oil to biodiesel were investigated. Methanol with calcium oxide as a heterogeneous catalyst was used for the transesterification process at a temperature of 60 degrees C using different methods of biodiesel production such as mechanical stirring (MS) and ultrasonic cavitation (US). US techniques have shown a faster reaction rate than the MS method. The maximum biodiesel yield of 94.1% was obtained in 2 hours using a methanol-to-oil molar ratio of 12:1, a catalyst amount of 5 w/w% and a reaction temperature of 60 degrees C by the ultrasonic cavitation method, along with improved physiochemical characteristics and very reduced energy consumption.