In-line ultrasonic monitoring of biodiesel production

Biodiesel is an evolution in the attempt to substitute diesel oil by biomass. The aim of this paper is show the development of the method to monitor the transesterification reaction “in line of process” using the ultrasound technique. The materials used in this study were degummed soybean oil, methanol and ethanol and potassium hydroxide (KOH). Two catalytic routes were tested, both of them using soybean oil and KOH, as catalyser. The difference between them was the alcohol used (methanol and ethanol). The test was carried out in batch without heating, and with stirring. The results showed that the time of flight, as well as the echo amplitude, present different behaviours depending on the type of alcohol used. Although the study is still in progress, preliminary results suggest that the proposed method may be feasible to monitor the reactions of biodiesel during its fabrication, in real time and with relatively low cost equipment.