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Product separation after chemical interesterification of vegetable oils with methyl acetate. Part I / Abraham Casas in Industrial & engineering chemistry research, Vol. 51 N° 23 (Juin 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 23 (Juin 2012) . - pp. 8087-8094 Titre : Product separation after chemical interesterification of vegetable oils with methyl acetate. Part I : Vapor – liquid equilibrium Type de document : texte imprimé Auteurs : Abraham Casas, Auteur ; Maria Jesús Ramos, Auteur ; Angel Pérez, Auteur Année de publication : 2012 Article en page(s) : pp. 8087-8094 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Phase  equilibrium  Liquid  vapor  equilibrium  Vegetable  oil Résumé : Chemical interesterification of triglycerides with methyl acetate yields biodiesel and triacetin. This reaction is highly reversible, which implies the presence of intermediate compounds such as diacetinmonoglycerides. In addition, the use of methanolic potassium methoxide as the catalyst causes the appearance of diacetin, monoacetin, and glycerol. Vacuum distillation becomes an interesting alternative for the separation of biodiesel and triacetin. Vapor―liquid equilibrium (VLE) determination requires information related to the vapor pressures of the different compounds and the nonideality of the liquid phase (activity coefficients). The lack of literature information for some compounds was supplemented with experimental data and predictive models for vapor pressure and activity coefficients (UNIFAC and UNIFAC Dortmund). The suitability of using vacuum distillation was evaluated using the Fenske equation and experimental results from a structured packed distillation column. According to the results, removal of diacetinmonoglycerides can be easily accomplished, unlike the elimination of diacetin, monoacetin, and glycerol, which form azeotropes with triacetin. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25990321 [article] Product separation after chemical interesterification of vegetable oils with methyl acetate. Part I : Vapor – liquid equilibrium [texte imprimé] / Abraham Casas, Auteur ; Maria Jesús Ramos, Auteur ; Angel Pérez, Auteur . - 2012 . - pp. 8087-8094. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 23 (Juin 2012) . - pp. 8087-8094 Mots-clés : Phase  equilibrium  Liquid  vapor  equilibrium  Vegetable  oil Résumé : Chemical interesterification of triglycerides with methyl acetate yields biodiesel and triacetin. This reaction is highly reversible, which implies the presence of intermediate compounds such as diacetinmonoglycerides. In addition, the use of methanolic potassium methoxide as the catalyst causes the appearance of diacetin, monoacetin, and glycerol. Vacuum distillation becomes an interesting alternative for the separation of biodiesel and triacetin. Vapor―liquid equilibrium (VLE) determination requires information related to the vapor pressures of the different compounds and the nonideality of the liquid phase (activity coefficients). The lack of literature information for some compounds was supplemented with experimental data and predictive models for vapor pressure and activity coefficients (UNIFAC and UNIFAC Dortmund). The suitability of using vacuum distillation was evaluated using the Fenske equation and experimental results from a structured packed distillation column. According to the results, removal of diacetinmonoglycerides can be easily accomplished, unlike the elimination of diacetin, monoacetin, and glycerol, which form azeotropes with triacetin. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25990321

Product separation after chemical interesterification of vegetable oils with methyl acetate. Part II / Abraham Casas in Industrial & engineering chemistry research, Vol. 51 N° 30 (Août 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 30 (Août 2012) . - pp. 10201–10206 Titre : Product separation after chemical interesterification of vegetable oils with methyl acetate. Part II : Liquid – liquid equilibrium Type de document : texte imprimé Auteurs : Abraham Casas, Auteur ; Maria Jesús Ramos, Auteur ; Angel Pérez, Auteur Année de publication : 2012 Article en page(s) : pp. 10201–10206 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Vegetable  Oils  Liquid  equilibrium Résumé : The aim of this work was the removal of diacetin, monoacetin, and glycerol from biodiesel–triacetin mixtures using liquid–liquid extraction with water. Liquid–liquid equilibrium was predicted using UNIFAC based models for the activity coefficient calculations. These data have been corroborated with experimental information from all possible binary, ternary (water, triacetin, and biodiesel), and overall (diacetin, monoacetin, glycerol, water, triacetin, and biodiesel) mixtures. The experimental determination of the diacetin, monoacetin, and glycerol distribution factor and their selectivity with respect to triacetin allows the operating temperature set at 27.5 °C. After that, it was determined that three washing steps, with a water to feed mixture mass ratio of 0.05 (per stage), were necessary for the effective elimination of these compounds. The final composition of the raffinate phase was 94.6 wt % biodiesel and 5.1 wt % triacetin. The extract phase consisted of a mixture of 59.2 wt % acetins and glycerol and 40.7 wt % water. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300791g [article] Product separation after chemical interesterification of vegetable oils with methyl acetate. Part II : Liquid – liquid equilibrium [texte imprimé] / Abraham Casas, Auteur ; Maria Jesús Ramos, Auteur ; Angel Pérez, Auteur . - 2012 . - pp. 10201–10206. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 30 (Août 2012) . - pp. 10201–10206 Mots-clés : Vegetable  Oils  Liquid  equilibrium Résumé : The aim of this work was the removal of diacetin, monoacetin, and glycerol from biodiesel–triacetin mixtures using liquid–liquid extraction with water. Liquid–liquid equilibrium was predicted using UNIFAC based models for the activity coefficient calculations. These data have been corroborated with experimental information from all possible binary, ternary (water, triacetin, and biodiesel), and overall (diacetin, monoacetin, glycerol, water, triacetin, and biodiesel) mixtures. The experimental determination of the diacetin, monoacetin, and glycerol distribution factor and their selectivity with respect to triacetin allows the operating temperature set at 27.5 °C. After that, it was determined that three washing steps, with a water to feed mixture mass ratio of 0.05 (per stage), were necessary for the effective elimination of these compounds. The final composition of the raffinate phase was 94.6 wt % biodiesel and 5.1 wt % triacetin. The extract phase consisted of a mixture of 59.2 wt % acetins and glycerol and 40.7 wt % water. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300791g