In a typical run, water bath temperature wasfixed at 56
C and
the desired amount of oil was transferred into the reactor. Then, the
required pre-heated amount of methanol was added to the oil
followed by the catalyst. Ultrasonic irradiation was then provided
in a discrete pattern with 9 s on and 3 s off. In this system, the heat
generated by the ultrasonic probe combined with the heat gained
from the water bath successfully kept the reaction vessel at
651
C. After the reaction, the products were quenched in water
and excess methanol was distilled out. After centrifugation at
3000 rpm for 20 min, the biodiesel layer was collected for analysis