Documents disponibles écrits par cet auteur

Solid-acid-catalyzed esterification of oleic acid assisted by microwave heating / Carlos A. R. Melo Junior in Industrial & engineering chemistry research, Vol. 49 N° 23 (Décembre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 23 (Décembre 2010) . - pp. 12135–12139 Titre : Solid-acid-catalyzed esterification of oleic acid assisted by microwave heating Type de document : texte imprimé Auteurs : Carlos A. R. Melo Junior, Auteur ; Carlos E. R. Albuquerque, Auteur ; Juliana S. A. Carneiro, Auteur Année de publication : 2011 Article en page(s) : pp. 12135–12139 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Solid  acid  catalysts Résumé : 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. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100501d [article] Solid-acid-catalyzed esterification of oleic acid assisted by microwave heating [texte imprimé] / Carlos A. R. Melo Junior, Auteur ; Carlos E. R. Albuquerque, Auteur ; Juliana S. A. Carneiro, Auteur . - 2011 . - pp. 12135–12139. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 23 (Décembre 2010) . - pp. 12135–12139 Mots-clés : Solid  acid  catalysts Résumé : 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. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100501d