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The phase behavior effect on the kinetics of transesterification reactions for biodiesel production / Stephen N. Csernica in Industrial & engineering chemistry research, Vol. 51 N° 18 (Mai 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 18 (Mai 2012) . - pp. 6340-6349 Titre : The phase behavior effect on the kinetics of transesterification reactions for biodiesel production Type de document : texte imprimé Auteurs : Stephen N. Csernica, Auteur ; James T. Hsu, Auteur Année de publication : 2012 Article en page(s) : pp. 6340-6349 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Production  Transesterification  Kinetics Résumé : The phase behavior effect on the kinetics of transesterification reactions is investigated in this study. First, the partition coefficient of the catalyst, KOH, was determined. It was found that the vast majority of the catalyst resides in the methanol phase; thus this phase is taken as the primary reaction volume. Mass transfer studies of soybean oil triglycerides show that triglycerides are in fact soluble in methanol. Additionally, it is shown that the rate of mass transfer and the equilibrium concentration of triglycerides in methanol increase with increasing methyl ester concentration Establishing the methanol phase as the primary reaction volume facilitated the thorough investigation of the rate-limiting step. First, the terms mass transfer control and rcaction control are finally defined for transesterification reactions. Once properly defined, it is shown that the sigmoidal, or S-shaped, methyl ester production curve that is so often observed is not necessarily caused by a transition from a mass transfer controlled regime to a reaction controlled regime, as is so often speculated in the literature. Rather, it is shown that the cause of the acceleration, regardless of the rate-limiting step, is caused by a transition from a two-phase system to a single-phase system. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25867285 [article] The phase behavior effect on the kinetics of transesterification reactions for biodiesel production [texte imprimé] / Stephen N. Csernica, Auteur ; James T. Hsu, Auteur . - 2012 . - pp. 6340-6349. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 18 (Mai 2012) . - pp. 6340-6349 Mots-clés : Production  Transesterification  Kinetics Résumé : The phase behavior effect on the kinetics of transesterification reactions is investigated in this study. First, the partition coefficient of the catalyst, KOH, was determined. It was found that the vast majority of the catalyst resides in the methanol phase; thus this phase is taken as the primary reaction volume. Mass transfer studies of soybean oil triglycerides show that triglycerides are in fact soluble in methanol. Additionally, it is shown that the rate of mass transfer and the equilibrium concentration of triglycerides in methanol increase with increasing methyl ester concentration Establishing the methanol phase as the primary reaction volume facilitated the thorough investigation of the rate-limiting step. First, the terms mass transfer control and rcaction control are finally defined for transesterification reactions. Once properly defined, it is shown that the sigmoidal, or S-shaped, methyl ester production curve that is so often observed is not necessarily caused by a transition from a mass transfer controlled regime to a reaction controlled regime, as is so often speculated in the literature. Rather, it is shown that the cause of the acceleration, regardless of the rate-limiting step, is caused by a transition from a two-phase system to a single-phase system. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25867285