—Biodiesel has been produced by transesterification of soybean oil by methanol. This reaction, heterogeneous, only takes place in the interphase alcohol triglyceride. Lowfrequency ultrasonic irradiation produces an emulsion of the two immiscible liquids, improving mass transfer and getting that the chemical reaction controls the kinetic of the process. This causes an increase of the reaction rate, decreasing time of reaction. Abatch and a continuous process were carried out, using potassium hydroxide as catalyst. A Branson processor of 20 kHz was used in all of the experiments. In the batch process methanol: oil molar ratio (3:1 to 15:1), maximum temperature (70 and 100 ºC) and ultrasound amplitude (40 to 100%) were studied. In the continuous process, methanol: oil molar ratio (6:1, 12:1 and 15:1) and catalyst concentration (0.28 to 0.70 g.mL-1) were evaluated. In the first process, MeOH:oil molar ratio influenced on the yield, while temperature did not exercise influence. Amplitude affected reaction rate, but the conversion achieved was similar after 15 minutes. In the continuous process, the MeOH:oil molar ratio influenced in the reaction, while the concentration of catalyst had a positive effect only to low residence times.
—Biodiesel, soybean oil, transesterification, ultrasonic irradiation.
J. M. Encinar, N. Sanchez, G. Martínez, and D. Álvarez are with the Department of Chemical Engineering and Physical Chemistry, University of Extremadura, Avda. Elvas s/n, 06006 Badajoz, Spain (e-mail: firstname.lastname@example.org, email@example.com, firstname.lastname@example.org).
J. F. González is with the Department of Applied Physics, University of Extremadura, Avda. Elvas s/n, 06006 Badajoz, Spain (e-mail: email@example.com).
Cite:José M. Encinar, Gloria Martínez, Juan F. González, Nuria Sánchez, and Dolores Álvarez, "Biodiesel from Soybean Oil Transesterification Assisted by Ultrasonic Irradiation," International Journal of Environmental Science and Development vol. 6, no. 1, pp. 48-53, 2015.