Kinetic model of biodiesel processing with ultrasound

Conventional process of biodiesel production is carried out in a batch system with mechanical stirrer. This process needs 30 up to 120 minutes for a complete reaction and produces less than 96% conversion of vegetable oil to biodiesel. Ultrasound is predicted to be able to accelerate the chemical reaction, to increase the conversion of vegetable oil into biodiesel, and to decrease the need of catalyst and energy input. Mathematical model and the application of ultrasound for processing of biodiesel were conducted in this research. The result of the experiments showed that the ultrasound increased reaction rate and the conversion of palm oil into biodiesel up to 100 % in 1 minute. Simulation with experiment data showed that the acceleration of transesferification with ultrasound was affected not only by natural mixing and increasing temperature but also the cavitations, surface tension of micro bubble, and hot spot accelerate chemical reaction. In fact, transesterification of palm oil with ultrasound still needs catalyst. However, the concentration was lower than that with mechanical stirrer. Ultrasound improves reaction rate and conversion of palm oil into biodiesel, and decrease the need of catalyst.