Study of enzyme-catalyzed biodiesel process with high FFA oil assisted by ultrasonic

摘要

The enzyme-catalyzed esterification and transesterification of waste oil with 1-propanol to biodiesel assisted with ultrasonic by an immobilized lipase Novozym 435 was studied. It was found that with the assistant of mild energy and low frequency ultrasonic, the enzyme-catalyzed esterification and transesterification velocites were advanced and higher conversion ratio to propyl oleate was achieved in shorter reaction time compared to conventional mechanical agitation. The optimal reaction and the frequency and power of ultrasonic, 28 KHz and 100W. Under such conditions, the conversion ratio achieved was almost 94% in 40 min in comparison with the highest almost 84% conversion ratio achieved. Furthermore, the ultrasonic energy was important to accelerating the speed of diffusing production in reaction system and enhancing the transesterification activity of immobilized lipase.