Comparison of formic and sulfuric acids as a glucose decomposition catalyst / Laura Kupiainen in Industrial & engineering chemistry research, Vol. 49 N° 18 (Septembre 2010)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 49 N° 18 (Septembre 2010) . - pp. 8444–8449 Titre : Comparison of formic and sulfuric acids as a glucose decomposition catalyst Type de document : texte imprimé Auteurs : Laura Kupiainen, Auteur ; Juha Ahola, Auteur ; Juha Tanskanen, Auteur Année de publication : 2010 Article en page(s) : pp. 8444–8449 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Sulfuric acids Catalyst Résumé : Dilute sulfuric acid hydrolysis of cellulose is the oldest and a well-studied technology for converting biomass to ethanol. Despite continuous technology improvements, the process still gives only a moderate selectivity due to glucose decomposition in the cellulose hydrolysis conditions. According to the recent literature, carboxylic acids have been recognized as more selective acid hydrolysis catalysts than sulfuric acid in low hydrogen ion concentrations. In this paper, formic acid was compared to sulfuric acid as a glucose decomposition catalyst at values below pH 2.2 at 180−220 °C. It was found that glucose decomposition depends only on the hydrogen ion concentration in the prevailing reaction conditions and is independent of the hydrogen ion source. Earlier contradictory findings can be the consequence of ignoring the temperature function of the dissociation constants of the acids and setting hydrogen ion concentrations at room temperature. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1008822 [article] Comparison of formic and sulfuric acids as a glucose decomposition catalyst [texte imprimé] / Laura Kupiainen, Auteur ; Juha Ahola, Auteur ; Juha Tanskanen, Auteur . - 2010 . - pp. 8444–8449. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 18 (Septembre 2010) . - pp. 8444–8449 Mots-clés : Sulfuric acids Catalyst Résumé : Dilute sulfuric acid hydrolysis of cellulose is the oldest and a well-studied technology for converting biomass to ethanol. Despite continuous technology improvements, the process still gives only a moderate selectivity due to glucose decomposition in the cellulose hydrolysis conditions. According to the recent literature, carboxylic acids have been recognized as more selective acid hydrolysis catalysts than sulfuric acid in low hydrogen ion concentrations. In this paper, formic acid was compared to sulfuric acid as a glucose decomposition catalyst at values below pH 2.2 at 180−220 °C. It was found that glucose decomposition depends only on the hydrogen ion concentration in the prevailing reaction conditions and is independent of the hydrogen ion source. Earlier contradictory findings can be the consequence of ignoring the temperature function of the dissociation constants of the acids and setting hydrogen ion concentrations at room temperature. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1008822

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Kinetics of xylose dehydration into furfural in formic acid / Kaisa Lamminpaa in Industrial & engineering chemistry research, Vol. 51 N° 18 (Mai 2012)  

Public ISBD [article]  inIndustrial & engineering chemistry research > Vol. 51 N° 18 (Mai 2012) . - pp. 6297-6303 Titre : Kinetics of xylose dehydration into furfural in formic acid Type de document : texte imprimé Auteurs : Kaisa Lamminpaa, Auteur ; Juha Ahola, Auteur ; Juha Tanskanen, Auteur Année de publication : 2012 Article en page(s) : pp. 6297-6303 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Dehydration Kinetics Résumé : In this study, kinetics of formic add-catalyzed xylose dehydration into furfural and furfural decomposition was investigated using batch experiments within a temperature range of 130-200 °C. Initial xylose and furfural concentrations up to 0.2 and 0.08 mol/L, respectively, were used. The room temperature pH of the formic add catalyst solution was between 0.9 and 1.7. The kinetic model used was based on a specific acid catalysis model and included the prevailing hydrogen ion concentration in reaction conditions. The study showed that the modeling must account for other reactions for xylose besides dehydration into furfural. Moreover, the reactions between xylose intermediate and furfural play only a minor role. The study also showed that kinetic modeling of xylose and furfural decomposition reactions must take the uncatalyzed reaction in water solvent into account. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25867280 [article] Kinetics of xylose dehydration into furfural in formic acid [texte imprimé] / Kaisa Lamminpaa, Auteur ; Juha Ahola, Auteur ; Juha Tanskanen, Auteur . - 2012 . - pp. 6297-6303. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 18 (Mai 2012) . - pp. 6297-6303 Mots-clés : Dehydration Kinetics Résumé : In this study, kinetics of formic add-catalyzed xylose dehydration into furfural and furfural decomposition was investigated using batch experiments within a temperature range of 130-200 °C. Initial xylose and furfural concentrations up to 0.2 and 0.08 mol/L, respectively, were used. The room temperature pH of the formic add catalyst solution was between 0.9 and 1.7. The kinetic model used was based on a specific acid catalysis model and included the prevailing hydrogen ion concentration in reaction conditions. The study showed that the modeling must account for other reactions for xylose besides dehydration into furfural. Moreover, the reactions between xylose intermediate and furfural play only a minor role. The study also showed that kinetic modeling of xylose and furfural decomposition reactions must take the uncatalyzed reaction in water solvent into account. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25867280

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