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Catalytic studies toward synthesis of 2,6 - dimethylnaphthalene from 1 - (p - Tolyl) - 2 - methylbutane / Kari Vahteristo in Industrial & engineering chemistry research, Vol. 49 N° 9 (Mai 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 9 (Mai 2010) . - pp. 4018–4025 Titre : Catalytic studies toward synthesis of 2,6 - dimethylnaphthalene from 1 - (p - Tolyl) - 2 - methylbutane Type de document : texte imprimé Auteurs : Kari Vahteristo, Auteur ; Kari-Matti Sahala, Auteur ; Salme Koskimies, Auteur Année de publication : 2010 Article en page(s) : pp. 4018–4025 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Catalysts Résumé : In this work experiments have been performed in order to study the synthesis of 2,6-dimethylnaphthalene (DMN) via dehydrocyclizing 1-(p-tolyl)-2-methylbutane over Pt/SiO2, V/Ca/Al2O3, and unimpregnated or potassium-impregnated Cr2O3/Al2O3 catalysts. The obtained liquid product mixture consisted of 1,6-cyclization products (dimethylnaphthalenes) and dealkylated 1,6-cyclization products (2-methylnaphthalene and naphthalene), 1,5-cyclization products (trimethylindanes and -indenes), and fragmentation products (mainly p-xylene and 3-(p-tolyl)-propylenes) and 1-(p-tolyl)-2-methylbutenes. Among 10 possible DMN isomers 1,5-, 1,6-, 2,6-, and 2,7-DMN were identified. Metal catalysts V/Ca/Al2O3 (5 wt % vanadium) and Pt/SiO2 (1 wt % platinum) were slightly more active than unimpregnated commercial Cr2O3/Al2O3. After 1 h on-stream time the conversion of 1-(p-tolyl)-2-methylbutane was 96 mol % when the artificial contact time (1/weight-hourly space velocity (WHSV)) was 5.7 h at 783 K over unimpregnated Cr2O3/Al2O3. Potassium impregnation decreased the conversion into 84 mol % because of the decreased Brunauer−Emmett−Teller surface area (from 97 m2/g unimpregnated to 70 m2/g potassium-impregnated catalyst). ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9008887 [article] Catalytic studies toward synthesis of 2,6 - dimethylnaphthalene from 1 - (p - Tolyl) - 2 - methylbutane [texte imprimé] / Kari Vahteristo, Auteur ; Kari-Matti Sahala, Auteur ; Salme Koskimies, Auteur . - 2010 . - pp. 4018–4025. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 9 (Mai 2010) . - pp. 4018–4025 Mots-clés : Catalysts Résumé : In this work experiments have been performed in order to study the synthesis of 2,6-dimethylnaphthalene (DMN) via dehydrocyclizing 1-(p-tolyl)-2-methylbutane over Pt/SiO2, V/Ca/Al2O3, and unimpregnated or potassium-impregnated Cr2O3/Al2O3 catalysts. The obtained liquid product mixture consisted of 1,6-cyclization products (dimethylnaphthalenes) and dealkylated 1,6-cyclization products (2-methylnaphthalene and naphthalene), 1,5-cyclization products (trimethylindanes and -indenes), and fragmentation products (mainly p-xylene and 3-(p-tolyl)-propylenes) and 1-(p-tolyl)-2-methylbutenes. Among 10 possible DMN isomers 1,5-, 1,6-, 2,6-, and 2,7-DMN were identified. Metal catalysts V/Ca/Al2O3 (5 wt % vanadium) and Pt/SiO2 (1 wt % platinum) were slightly more active than unimpregnated commercial Cr2O3/Al2O3. After 1 h on-stream time the conversion of 1-(p-tolyl)-2-methylbutane was 96 mol % when the artificial contact time (1/weight-hourly space velocity (WHSV)) was 5.7 h at 783 K over unimpregnated Cr2O3/Al2O3. Potassium impregnation decreased the conversion into 84 mol % because of the decreased Brunauer−Emmett−Teller surface area (from 97 m2/g unimpregnated to 70 m2/g potassium-impregnated catalyst). ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9008887

Kinetics of neopentyl glycol esterification with different carboxylic acids / Kari Vahteristo in Industrial & engineering chemistry research, Vol. 48 N° 13 (Juillet 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 13 (Juillet 2009) . - pp. 6237–6247 Titre : Kinetics of neopentyl glycol esterification with different carboxylic acids Type de document : texte imprimé Auteurs : Kari Vahteristo, Auteur ; Sylvie Maury, Auteur ; Arto Laari, Auteur Année de publication : 2009 Article en page(s) : pp. 6237–6247 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Neopentyl  glycol  esterification  Carboxylic  acids Résumé : The aim of this work was to study the reaction kinetics of neopentyl glycol esterification with different carboxylic acids (propionic acid, isobutyric acid and 2-ethylhexanoic acid). The experiments were carried out in a batch reactor as reactive distillation removing continuously one reaction product (water) by purging nitrogen through the reactor. Commercial heterogeneous gellular (Dowex 50WX2) and macroreticular (Amberlyst 15) type resins and homogeneous para-toluene sulfonic acid were compared as catalysts. The gellular type resin was dried before loading into the reactor. When performing esterification of neopentyl glycol with different acids the observed formation of monoester was clearly much faster than the consecutive esterification of monoester to diester. A disproportionation reaction was also found to take place. The reliability of the estimated Arrhenius parameters was analyzed using Bayesian inference and Markov chain Monte Carlo methods (MCMC). MCMC analysis was also used to study uncertainties in the model predictions and in some additional parameters, such as reaction rate constants calculated from the estimated parameters. This cannot be done by classical regression analysis. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801920m [article] Kinetics of neopentyl glycol esterification with different carboxylic acids [texte imprimé] / Kari Vahteristo, Auteur ; Sylvie Maury, Auteur ; Arto Laari, Auteur . - 2009 . - pp. 6237–6247. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 13 (Juillet 2009) . - pp. 6237–6247 Mots-clés : Neopentyl  glycol  esterification  Carboxylic  acids Résumé : The aim of this work was to study the reaction kinetics of neopentyl glycol esterification with different carboxylic acids (propionic acid, isobutyric acid and 2-ethylhexanoic acid). The experiments were carried out in a batch reactor as reactive distillation removing continuously one reaction product (water) by purging nitrogen through the reactor. Commercial heterogeneous gellular (Dowex 50WX2) and macroreticular (Amberlyst 15) type resins and homogeneous para-toluene sulfonic acid were compared as catalysts. The gellular type resin was dried before loading into the reactor. When performing esterification of neopentyl glycol with different acids the observed formation of monoester was clearly much faster than the consecutive esterification of monoester to diester. A disproportionation reaction was also found to take place. The reliability of the estimated Arrhenius parameters was analyzed using Bayesian inference and Markov chain Monte Carlo methods (MCMC). MCMC analysis was also used to study uncertainties in the model predictions and in some additional parameters, such as reaction rate constants calculated from the estimated parameters. This cannot be done by classical regression analysis. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801920m