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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

Transesterification of castor oil / Rosaura Peña in Industrial & engineering chemistry research, Vol. 48 N°3 (Février 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N°3 (Février 2009) . - p. 1186–1189 Titre : Transesterification of castor oil : effect of catalyst and co-solvent Type de document : texte imprimé Auteurs : Rosaura Peña, Auteur ; Rubi Romero, Auteur ; Sandra Luz Martínez, Auteur ; Maria Jesús Ramos, Auteur Année de publication : 2009 Article en page(s) : p. 1186–1189 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Biodiesel  Castor  Oil  --  Transesterification  Catalyst  Methanol Résumé : Biodiesel is emerging as an alternative fuel with several advantages over the common petroleum based fuels. In its production, however, variables such as raw material, catalyst, and co-solvent are an issue worth exploring because of the impact they have on final biodiesel properties. Therefore, this work aims to establish the effect of the aforesaid variables on methyl ester content, viscosity, acidity, and water content of biodiesel produced from castor oil. In this context, the methanolysis of castor oil has been conducted at 60 °C in a batch reactor, and the effect of three alkaline catalysts (CH3ONa, NaOH, and KOH) and a co-solvent (hexane) has been established. It is concluded that sodium methoxide leads to considerably higher methyl ester content than the other essayed catalysts. Besides, when utilizing a co-solvent the methyl ester content increases up to a very close value (95.5%) to that established by the EN14214 norm (>96.5%). This has been ascribed to a significant improvement on oil−methanol contact. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8005929 [article] Transesterification of castor oil : effect of catalyst and co-solvent [texte imprimé] / Rosaura Peña, Auteur ; Rubi Romero, Auteur ; Sandra Luz Martínez, Auteur ; Maria Jesús Ramos, Auteur . - 2009 . - p. 1186–1189. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N°3 (Février 2009) . - p. 1186–1189 Mots-clés : Biodiesel  Castor  Oil  --  Transesterification  Catalyst  Methanol Résumé : Biodiesel is emerging as an alternative fuel with several advantages over the common petroleum based fuels. In its production, however, variables such as raw material, catalyst, and co-solvent are an issue worth exploring because of the impact they have on final biodiesel properties. Therefore, this work aims to establish the effect of the aforesaid variables on methyl ester content, viscosity, acidity, and water content of biodiesel produced from castor oil. In this context, the methanolysis of castor oil has been conducted at 60 °C in a batch reactor, and the effect of three alkaline catalysts (CH3ONa, NaOH, and KOH) and a co-solvent (hexane) has been established. It is concluded that sodium methoxide leads to considerably higher methyl ester content than the other essayed catalysts. Besides, when utilizing a co-solvent the methyl ester content increases up to a very close value (95.5%) to that established by the EN14214 norm (>96.5%). This has been ascribed to a significant improvement on oil−methanol contact. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8005929