Documents disponibles écrits par cet auteur

Dissolution of mineral fiber in a formic acid solution / Henrik Grenman ; Fernando Ramirez ; Kari Eranen in Industrial & engineering chemistry research, Vol. 47 n°24 (Décembre 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 n°24 (Décembre 2008) . - p. 9834–9841 Titre : Dissolution of mineral fiber in a formic acid solution : kinetics, modeling, and gelation of the resulting sol Type de document : texte imprimé Auteurs : Henrik Grenman, Auteur ; Fernando Ramirez, Auteur ; Kari Eranen, Auteur Année de publication : 2009 Article en page(s) : p. 9834–9841 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Mineral  fiber Résumé : A new inorganic adhesive based on sol−gel technology has been developed recently. The sol is produced by dissolving a mineral material, with silica as the major compound, in formic acid. In this work, the kinetics and mechanisms of the solid−liquid reaction of the amorphous mineral raw material with formic acid were studied. The effect of different variables, such as temperature, acid concentration, and fiber load, were examined. Moreover, the influence of various parameters on the gelation rate of the resulting sol was investigated at different temperatures. The dissolution of the mineral fiber was found to be strongly dependent on the temperature and fiber load, but moderately dependent on the acid concentration as the pH of the solution was buffered by the formic acid. The kinetic model developed for the dissolution process accurately describes the experimental results and can thus be used for design and optimization of the process. The gelation studies showed that the temperature and the amount dissolved are the variables most affecting the gelation time. The knowledge of the gelation kinetics is important when striving for a high dry solid content in the sol, while still avoiding premature gelation in production, transport, and storage. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800267a [article] Dissolution of mineral fiber in a formic acid solution : kinetics, modeling, and gelation of the resulting sol [texte imprimé] / Henrik Grenman, Auteur ; Fernando Ramirez, Auteur ; Kari Eranen, Auteur . - 2009 . - p. 9834–9841. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 n°24 (Décembre 2008) . - p. 9834–9841 Mots-clés : Mineral  fiber Résumé : A new inorganic adhesive based on sol−gel technology has been developed recently. The sol is produced by dissolving a mineral material, with silica as the major compound, in formic acid. In this work, the kinetics and mechanisms of the solid−liquid reaction of the amorphous mineral raw material with formic acid were studied. The effect of different variables, such as temperature, acid concentration, and fiber load, were examined. Moreover, the influence of various parameters on the gelation rate of the resulting sol was investigated at different temperatures. The dissolution of the mineral fiber was found to be strongly dependent on the temperature and fiber load, but moderately dependent on the acid concentration as the pH of the solution was buffered by the formic acid. The kinetic model developed for the dissolution process accurately describes the experimental results and can thus be used for design and optimization of the process. The gelation studies showed that the temperature and the amount dissolved are the variables most affecting the gelation time. The knowledge of the gelation kinetics is important when striving for a high dry solid content in the sol, while still avoiding premature gelation in production, transport, and storage. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800267a

Ethylene oxide formation in a microreactor / Jose R. Hernandez Carucci in Industrial & engineering chemistry research, Vol. 49 N° 21 (Novembre 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 21 (Novembre 2010) . - pp. 10897–10907 Titre : Ethylene oxide formation in a microreactor : From qualitative kinetics to detailed modeling Type de document : texte imprimé Auteurs : Jose R. Hernandez Carucci, Auteur ; Ville Halonen, Auteur ; Kari Eranen, Auteur Année de publication : 2011 Article en page(s) : pp. 10897–10907 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Microreactor  Kinetics Résumé : Silver/α-alumina catalysts were wash-coated in stainless steel microchannels. The microchannels were used for the epoxidation of ethylene. Pure silver microplates were also investigated giving the highest activities and selectivities toward the ethylene oxide formation. Pretreatment conditions with oxygen and ethylene for the pure silver catalyst were studied and optimized. The experiments were carried out under atmospheric pressure, varying the temperature from 220 to 300 °C and the total gas flow from 5.4 to 10.5 cm3/min. A precise kinetic model for the ethylene oxide formation in pure silver microchannels was developed at 260 °C. The model was based on the competitive adsorption of ethylene and molecular oxygen over the silver surface. The concentrations of the reactants (oxygen and ethylene) in the gas flow were systematically varied from 5 to 25 vol % using helium gas as balance. The model was confronted with experimental data obtained in the microchannels, resulting in a very high degree of explanation (97%). ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100521j [article] Ethylene oxide formation in a microreactor : From qualitative kinetics to detailed modeling [texte imprimé] / Jose R. Hernandez Carucci, Auteur ; Ville Halonen, Auteur ; Kari Eranen, Auteur . - 2011 . - pp. 10897–10907. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 21 (Novembre 2010) . - pp. 10897–10907 Mots-clés : Microreactor  Kinetics Résumé : Silver/α-alumina catalysts were wash-coated in stainless steel microchannels. The microchannels were used for the epoxidation of ethylene. Pure silver microplates were also investigated giving the highest activities and selectivities toward the ethylene oxide formation. Pretreatment conditions with oxygen and ethylene for the pure silver catalyst were studied and optimized. The experiments were carried out under atmospheric pressure, varying the temperature from 220 to 300 °C and the total gas flow from 5.4 to 10.5 cm3/min. A precise kinetic model for the ethylene oxide formation in pure silver microchannels was developed at 260 °C. The model was based on the competitive adsorption of ethylene and molecular oxygen over the silver surface. The concentrations of the reactants (oxygen and ethylene) in the gas flow were systematically varied from 5 to 25 vol % using helium gas as balance. The model was confronted with experimental data obtained in the microchannels, resulting in a very high degree of explanation (97%). ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100521j

Kinetics of aqueous extraction of hemicelluloses from spruce in an intensified reactor system / Henrik Grenman in Industrial & engineering chemistry research, Vol. 50 N° 7 (Avril 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 7 (Avril 2011) . - pp. 3818–3828 Titre : Kinetics of aqueous extraction of hemicelluloses from spruce in an intensified reactor system Type de document : texte imprimé Auteurs : Henrik Grenman, Auteur ; Kari Eranen, Auteur ; Jens Krogell, Auteur Année de publication : 2011 Article en page(s) : pp. 3818–3828 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Kinetics Résumé : The aqueous extraction of hemicelluloses has gained increasing interest with new emerging applications for hemicelluloses in the modern forest-based biorefinery concept. The extraction kinetics play a key role in their industrial utilization. The traditional kinetic studies and models for the selective dissolution of softwoods, however, always incorporate high concentrations of sodium hydroxide and sodium sulfide relevant to pulping, and the kinetics in pure water is left outside the scope of these investigations. Aqueous extraction of hemicelluloses from spruce sapwood was investigated with a new cascade reactor setup, which was developed for intensified investigation of solid−liquid dissolution kinetics. The experiments were performed at 150−170 °C with a particle size of 1.25−2 mm and solid loads of about 6.25 g of dry wood/L in the kinetic regime of intrinsic kinetics. The pH of the liquid phase was measured during the reaction. The selectivity of the dissolution and degradation of hemicelluloses was examined qualitatively. The total concentrations of arabinose (Ara), xylose (Xyl), galactose (Gal), glucose (Glc), mannose (Man), rhamnose (Rha), glucuronic acid (GlcA), 4-O-methylglucuronic acid (4-O-MeGlcA), and galacturonic acid (GalA) were analyzed from the liquid and solid phases during the reaction. The dissolution was observed to be highly temperature dependent, and degradation of the compounds was observed. A kinetic model was developed for the overall extraction of the hemicelluloses. The activation energy was determined to be 135 kJ/mol. No significant influence of the pH on the actual extraction kinetics was observed, even though it influences strongly the degradation of the compounds through hydrolysis. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101946c [article] Kinetics of aqueous extraction of hemicelluloses from spruce in an intensified reactor system [texte imprimé] / Henrik Grenman, Auteur ; Kari Eranen, Auteur ; Jens Krogell, Auteur . - 2011 . - pp. 3818–3828. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 7 (Avril 2011) . - pp. 3818–3828 Mots-clés : Kinetics Résumé : The aqueous extraction of hemicelluloses has gained increasing interest with new emerging applications for hemicelluloses in the modern forest-based biorefinery concept. The extraction kinetics play a key role in their industrial utilization. The traditional kinetic studies and models for the selective dissolution of softwoods, however, always incorporate high concentrations of sodium hydroxide and sodium sulfide relevant to pulping, and the kinetics in pure water is left outside the scope of these investigations. Aqueous extraction of hemicelluloses from spruce sapwood was investigated with a new cascade reactor setup, which was developed for intensified investigation of solid−liquid dissolution kinetics. The experiments were performed at 150−170 °C with a particle size of 1.25−2 mm and solid loads of about 6.25 g of dry wood/L in the kinetic regime of intrinsic kinetics. The pH of the liquid phase was measured during the reaction. The selectivity of the dissolution and degradation of hemicelluloses was examined qualitatively. The total concentrations of arabinose (Ara), xylose (Xyl), galactose (Gal), glucose (Glc), mannose (Man), rhamnose (Rha), glucuronic acid (GlcA), 4-O-methylglucuronic acid (4-O-MeGlcA), and galacturonic acid (GalA) were analyzed from the liquid and solid phases during the reaction. The dissolution was observed to be highly temperature dependent, and degradation of the compounds was observed. A kinetic model was developed for the overall extraction of the hemicelluloses. The activation energy was determined to be 135 kJ/mol. No significant influence of the pH on the actual extraction kinetics was observed, even though it influences strongly the degradation of the compounds through hydrolysis. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101946c

Reversible autocatalytic hydrolysis of alkyl formate / Olatunde Jogunola 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. 4099–4106 Titre : Reversible autocatalytic hydrolysis of alkyl formate : kinetic and reactor modeling Type de document : texte imprimé Auteurs : Olatunde Jogunola, Auteur ; Tapio Salmi, Auteur ; Kari Eranen, Auteur Année de publication : 2010 Article en page(s) : pp. 4099–4106 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydrolysis  Kinetic Résumé : The kinetics and thermodynamics of alkyl formate hydrolysis in liquid phase were studied in a laboratory-scale autoclave at temperatures between 333 and 383 K using different molar ratios of the reactants. The process was found to exhibit an autocatalytic effect due to the acid formed. More so, the rate of neutral hydrolysis of ethyl formate is faster compared to methyl formate in the uncatalyzed reaction. However, the autocatalytic effect is more pronounced in methyl formate hydrolysis. In addition, the effect of adding a small amount of formic acid as an initial charge upon the equilibrium conversion and kinetics was investigated, and it was found that the addition improved the reaction rate by reducing the induction period but it suppressed slightly the equilibrium conversion. A kinetic model was proposed to explain these experimental trends, and the model agreed well with the experimental results. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie902031d [article] Reversible autocatalytic hydrolysis of alkyl formate : kinetic and reactor modeling [texte imprimé] / Olatunde Jogunola, Auteur ; Tapio Salmi, Auteur ; Kari Eranen, Auteur . - 2010 . - pp. 4099–4106. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 9 (Mai 2010) . - pp. 4099–4106 Mots-clés : Hydrolysis  Kinetic Résumé : The kinetics and thermodynamics of alkyl formate hydrolysis in liquid phase were studied in a laboratory-scale autoclave at temperatures between 333 and 383 K using different molar ratios of the reactants. The process was found to exhibit an autocatalytic effect due to the acid formed. More so, the rate of neutral hydrolysis of ethyl formate is faster compared to methyl formate in the uncatalyzed reaction. However, the autocatalytic effect is more pronounced in methyl formate hydrolysis. In addition, the effect of adding a small amount of formic acid as an initial charge upon the equilibrium conversion and kinetics was investigated, and it was found that the addition improved the reaction rate by reducing the induction period but it suppressed slightly the equilibrium conversion. A kinetic model was proposed to explain these experimental trends, and the model agreed well with the experimental results. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie902031d