Solid-Acid-Catalyzed Esterification of Oleic Acid Assisted by Microwave Heating

• Published in: Industrial & engineering chemistry research 2010-12, Vol.49 (23), p.12135-12139
• Main Authors: Melo Júnior, Carlos A. R, Albuquerque, Carlos E. R, Carneiro, Juliana S. A, Dariva, Claudio, Fortuny, Montserrat, Santos, Alexandre F, Egues, Silvia M. S, Ramos, André L. D
• Format: Article
• Language: English
• Subjects: Applied Chemistry; Applied sciences; Catalysis; Catalytic reactions; Chemical engineering; Chemistry; Exact sciences and technology; General and physical chemistry; Reactors; Theory of reactions, general kinetics. Catalysis. Nomenclature, chemical documentation, computer chemistry
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/ie100501d

This work aims to evaluate the activity and stability of solid acid catalysts (niobium oxide and sulfated zirconia) in the methyl esterification of oleic acid assisted by microwave heating, an alternative route to the base-catalyzed transesterification reaction using conventional heating. Both catalysts have yielded similar conversions (68% for Nb2O5 and 68.7% for sulfated zirconia at 200 °C, t = 20 min, methanol-to-fatty acid molar ratio = 10, 5% w/w catalyst), much higher than the one obtained without catalyst (39.3%), besides a small deactivation after the fourth use (3% for Nb2O5, 11% for sulfated zirconia, compared to the first use). The results have not indicated a pronounced increase on reaction conversions by using microwave heating when compared to conventional data found in the literature. However, microwave irradiation remains attractive for heating esterification systems, since it allows for achieving high temperatures at reduced times.