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Chemical equilibrium and reaction kinetics of the heterogeneously catalyzed formation of poly(oxymethylene) dimethyl ethers from methylal and trioxane / Jakob Burger in Industrial & engineering chemistry research, Vol. 51 N° 39 (Octobre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 39 (Octobre 2012) . - pp. 12751–12761 Titre : Chemical equilibrium and reaction kinetics of the heterogeneously catalyzed formation of poly(oxymethylene) dimethyl ethers from methylal and trioxane Type de document : texte imprimé Auteurs : Jakob Burger, Auteur ; Eckhard Ströfer, Auteur ; Hans Hasse, Auteur Année de publication : 2012 Article en page(s) : pp. 12751–12761 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Kinetics  Heterogeneously  catalyzed Résumé : Poly(oxymethylene) dimethyl ethers (OMEs) are attractive components for tailoring diesel fuels. They belong to the group of oxygenates that reduce soot formation in the combustion when added to diesel fuels and can be produced on a large scale based on gas-to-liquid technology. This work deals with a particularly favorable route for their large scale production in which they are formed from methylal and trioxane. Reaction kinetics and chemical equilibrium of the OME formation via this route were studied in a batch reactor using the ion-exchange resin Amberlyst 46 as heterogeneous catalyst at temperatures between 323 and 363 K and for a wide range of feed compositions. An adsorption-based kinetic model is presented that represents both reaction kinetics and equilibrium well. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301490q [article] Chemical equilibrium and reaction kinetics of the heterogeneously catalyzed formation of poly(oxymethylene) dimethyl ethers from methylal and trioxane [texte imprimé] / Jakob Burger, Auteur ; Eckhard Ströfer, Auteur ; Hans Hasse, Auteur . - 2012 . - pp. 12751–12761. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 39 (Octobre 2012) . - pp. 12751–12761 Mots-clés : Kinetics  Heterogeneously  catalyzed Résumé : Poly(oxymethylene) dimethyl ethers (OMEs) are attractive components for tailoring diesel fuels. They belong to the group of oxygenates that reduce soot formation in the combustion when added to diesel fuels and can be produced on a large scale based on gas-to-liquid technology. This work deals with a particularly favorable route for their large scale production in which they are formed from methylal and trioxane. Reaction kinetics and chemical equilibrium of the OME formation via this route were studied in a batch reactor using the ion-exchange resin Amberlyst 46 as heterogeneous catalyst at temperatures between 323 and 363 K and for a wide range of feed compositions. An adsorption-based kinetic model is presented that represents both reaction kinetics and equilibrium well. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301490q

Online NMR spectroscopic study of species distribution in MDEA-H2O-CO2 and MDEA-PIP-H2O-CO2 / Wolfram Bottinger in Industrial & engineering chemistry research, Vol. 47 N°20 (Octobre 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 N°20 (Octobre 2008) . - P. 7917-7926 Titre : Online NMR spectroscopic study of species distribution in MDEA-H2O-CO2 and MDEA-PIP-H2O-CO2 Type de document : texte imprimé Auteurs : Wolfram Bottinger, Auteur ; Michael Maiwald, Auteur ; Hans Hasse, Auteur Année de publication : 2008 Article en page(s) : P. 7917-7926 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Nuclear  magnetic  resonance(NMR)  Carbon  dioxide  (CO2)  Vapor-liquid  equilibrium  (VLE) Résumé : Quantitative online nuclear magnetic resonance (NMR) spectroscopy was used to study the species distribution in solutions of carbon dioxide (CO2) in aqueous N-methyldiethanolamine (MDEA), and MDEA + piperazine (PIP). The mass fraction of MDEA in the unloaded ternary solution was 0.2, 0.3, and 0.4 g/g. In quaternary solutions, the mass fraction of MDEA was 0.3 g/g, and that of PIP was 0.1 g/g. The temperature ranged from 293 K to 333 K, and the overall CO2 loading was up to 1.4 molCO2/molamine. For the measurements, a special apparatus was used that allowed the mixtures to be prepared gravimetrically and applied pressures up to 25 bar to keep the CO2 in solution. It was coupled to a 400 MHz NMR spectrometer by heated capillaries. Using both 1H and 13C NMR spectroscopy, quantitative information on the concentrations of the following species was obtained: amines, carbamates, bicarbonate, and CO2. Because of the fast proton transfer between molecular and protonated amines, only the sum of their concentrations can be determined. Furthermore, a byproduct was observed and quantified. The experimental data were used to develop a thermodynamic model of the studied electrolyte solutions, based on the extended Pitzer GE-model. In the model development, vapor−liquid equilibrium (VLE) data from the literature also were included. The model describes both the species distribution and the VLE of the studied mixtures. The properties of the quaternary system are predicted from information on the subsystems. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800914m [article] Online NMR spectroscopic study of species distribution in MDEA-H2O-CO2 and MDEA-PIP-H2O-CO2 [texte imprimé] / Wolfram Bottinger, Auteur ; Michael Maiwald, Auteur ; Hans Hasse, Auteur . - 2008 . - P. 7917-7926. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N°20 (Octobre 2008) . - P. 7917-7926 Mots-clés : Nuclear  magnetic  resonance(NMR)  Carbon  dioxide  (CO2)  Vapor-liquid  equilibrium  (VLE) Résumé : Quantitative online nuclear magnetic resonance (NMR) spectroscopy was used to study the species distribution in solutions of carbon dioxide (CO2) in aqueous N-methyldiethanolamine (MDEA), and MDEA + piperazine (PIP). The mass fraction of MDEA in the unloaded ternary solution was 0.2, 0.3, and 0.4 g/g. In quaternary solutions, the mass fraction of MDEA was 0.3 g/g, and that of PIP was 0.1 g/g. The temperature ranged from 293 K to 333 K, and the overall CO2 loading was up to 1.4 molCO2/molamine. For the measurements, a special apparatus was used that allowed the mixtures to be prepared gravimetrically and applied pressures up to 25 bar to keep the CO2 in solution. It was coupled to a 400 MHz NMR spectrometer by heated capillaries. Using both 1H and 13C NMR spectroscopy, quantitative information on the concentrations of the following species was obtained: amines, carbamates, bicarbonate, and CO2. Because of the fast proton transfer between molecular and protonated amines, only the sum of their concentrations can be determined. Furthermore, a byproduct was observed and quantified. The experimental data were used to develop a thermodynamic model of the studied electrolyte solutions, based on the extended Pitzer GE-model. In the model development, vapor−liquid equilibrium (VLE) data from the literature also were included. The model describes both the species distribution and the VLE of the studied mixtures. The properties of the quaternary system are predicted from information on the subsystems. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800914m