Transesterification of soybean frying oil to biodiesel using heterogeneous catalysts

• Published in: Fuel processing technology Vol. 90; no. 5; pp. 671 - 676
• Main Authors: Georgogianni, K.G., Katsoulidis, A.P., Pomonis, P.J., Kontominas, M.G.
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.05.2009; Elsevier
• Subjects: Applied sciences; Biodiesel; Biomass; Energy; Exact sciences and technology; Heterogeneous catalysis; Natural energy; Soybean oil; Transesterification; Heterogeneous catalysis; Transesterification; Soybean oil; Biodiesel; Scanning electron microscopy; Diesel fuel; Porosimetry; Biofuel; Desorption; Zirconium oxide; Adsorption; Porosity; X ray diffractometry; Frying oil; Catalyst activity; Catalyst; Methanol
• ISSN: 0378-3820; 1873-7188
• DOI: 10.1016/j.fuproc.2008.12.004

In the present work, the transesterification reaction of soybean frying oil with methanol, in the presence of different heterogeneous catalysts (Mg MCM-41, Mg-Al Hydrotalcite, and K + impregnated zirconia), using low frequency ultrasonication (24 KHz) and mechanical stirring (600 rpm) for the production of biodiesel fuel was studied. Selection of catalysts was based on a combination of porosity and surface basicity. Their characterization was carried out using X-ray diffraction, Nitrogen adsorption-desorption porosimetry and scanning electron microscopy (SEM) with energy dispersive spectra (EDS). The activities of the catalysts were related to their basic strength. Mg-Al hydrotalcite showed particularly the highest activity (conversion 97%). It is important to mention that the catalyst activity of ZrO 2 in the transesterification reaction increased as the catalyst was enriched with more potassium cations becoming more basic. Use of ultrasonication significantly accelerated the transesterification reaction compared to the use of mechanical stirring (5 h versus 24 h).