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Arvind Varma / Massimo Morbidelli in Industrial & engineering chemistry research, Vol. 47 N° 23 (Décembre 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 8957–8959 Titre : Arvind Varma : Educator, Researcher and Leader Type de document : texte imprimé Auteurs : Massimo Morbidelli, Auteur ; Bala Subramaniam, Auteur Année de publication : 2009 Article en page(s) : p. 8957–8959 Note générale : Engineering Chemistry Langues : Anglais (eng) Mots-clés : Arvind  Varma  --  Educator,  Researcher  and  Leader En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801563q [article] Arvind Varma : Educator, Researcher and Leader [texte imprimé] / Massimo Morbidelli, Auteur ; Bala Subramaniam, Auteur . - 2009 . - p. 8957–8959. Engineering Chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N° 23 (Décembre 2008) . - p. 8957–8959 Mots-clés : Arvind  Varma  --  Educator,  Researcher  and  Leader En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801563q

Exploiting neoteric solvents for sustainable catalysis and reaction engineering / Bala Subramaniam 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. 10218-10229 Titre : Exploiting neoteric solvents for sustainable catalysis and reaction engineering : Opportunities and challenges Type de document : texte imprimé Auteurs : Bala Subramaniam, Auteur Année de publication : 2011 Article en page(s) : pp. 10218-10229 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Reaction  engineering  Catalysis Résumé : The modern refinery relies primarily on feedstocks based on fossil fuels (such as petroleum, natural gas, and coal) to produce fuels and chemicals. Several megaton catalytic processes (such as homogeneous hydroformylation of higher olefins, epoxidation of light olefins, and p-xylene oxidation to produce terephthalic acid) exist that produce the essential chemical intermediates for everyday products but present sustainability challenges with respect to reducing environmental footprints and enhancing energy efficiency. Meeting the increasing demand for such chemicals, through either fossil-based feedstock or plant-based biomass, will require the development of novel sustainable processes. This article highlights the role and promise of neoteric solvents such as compressed CO2, ionic liquids, and water, with an emphasis on gas-expanded liquids (GXLs), for the development of sustainable catalytic processes and the challenges thereof. It is also shown that chemical reaction engineering is the critical link to bring the promise of green chemistry to the marketplace. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23447910 [article] Exploiting neoteric solvents for sustainable catalysis and reaction engineering : Opportunities and challenges [texte imprimé] / Bala Subramaniam, Auteur . - 2011 . - pp. 10218-10229. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 21 (Novembre 2010) . - pp. 10218-10229 Mots-clés : Reaction  engineering  Catalysis Résumé : The modern refinery relies primarily on feedstocks based on fossil fuels (such as petroleum, natural gas, and coal) to produce fuels and chemicals. Several megaton catalytic processes (such as homogeneous hydroformylation of higher olefins, epoxidation of light olefins, and p-xylene oxidation to produce terephthalic acid) exist that produce the essential chemical intermediates for everyday products but present sustainability challenges with respect to reducing environmental footprints and enhancing energy efficiency. Meeting the increasing demand for such chemicals, through either fossil-based feedstock or plant-based biomass, will require the development of novel sustainable processes. This article highlights the role and promise of neoteric solvents such as compressed CO2, ionic liquids, and water, with an emphasis on gas-expanded liquids (GXLs), for the development of sustainable catalytic processes and the challenges thereof. It is also shown that chemical reaction engineering is the critical link to bring the promise of green chemistry to the marketplace. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23447910

Kinetic modeling of aqueous - phase glycerol hydrogenolysis in a batch slurry reactor / Arely Torres 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. 10826-10835 Titre : Kinetic modeling of aqueous - phase glycerol hydrogenolysis in a batch slurry reactor Type de document : texte imprimé Auteurs : Arely Torres, Auteur ; Debdut Roy, Auteur ; Bala Subramaniam, Auteur Année de publication : 2011 Article en page(s) : pp. 10826-10835 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Modeling  Particle  suspension  Reactor  Batchwise  Hydrogenolysis  Kinetic  model Résumé : The kinetics of the aqueous-phase hydrogenolysis of glycerol to 1,2-propanediol (1,2-PDO) was studied using a bimetallic Ru―Re/C catalyst in a slurry reactor in a temperature range of 493-513 K and a hydrogen pressure of 2.4-9.6 MPa. Glycerol hydrogenolysis to produce 1,2-PDO via C―O cleavage (i) proceeds with parallel C—C cleavage, reforming, water-gas shift, and Fischer-Tropsch reactions, (ii) results in a very complex reaction network with several gaseous- and liquid-phase products, and (iii) poses a challenge to design selective catalysts. It is observed that Ru―Re bimetallic catalyst shows higher hydrogenolysis activity (glycerol conversion of X = 57.7%) and 1,2-PDO selectivity (S = 36.6%), compared to the monometallic Ru catalyst (X = 52.1%; S = 18.9%) but the monometallic Re catalyst showed no catalytic activity for the reaction. Stirred-batch reactor data on the transient concentrations of reactants and products in both the gas and liquid phases were obtained using a bimetallic Ru-Re/C catalyst under different conditions to understand the reaction pathways, selectivity behavior, and intrinsic kinetics of the different reaction steps. For kinetic modeling, several experiments were performed at different initial pressures of hydrogen, catalyst concentration, and temperatures. The proposed rate equations, along with the regressed kinetic and activation energy parameters, were found to represent the experimental data for the multistep hydrogenolysis reaction very satisfactorily. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23447975 [article] Kinetic modeling of aqueous - phase glycerol hydrogenolysis in a batch slurry reactor [texte imprimé] / Arely Torres, Auteur ; Debdut Roy, Auteur ; Bala Subramaniam, Auteur . - 2011 . - pp. 10826-10835. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 21 (Novembre 2010) . - pp. 10826-10835 Mots-clés : Modeling  Particle  suspension  Reactor  Batchwise  Hydrogenolysis  Kinetic  model Résumé : The kinetics of the aqueous-phase hydrogenolysis of glycerol to 1,2-propanediol (1,2-PDO) was studied using a bimetallic Ru―Re/C catalyst in a slurry reactor in a temperature range of 493-513 K and a hydrogen pressure of 2.4-9.6 MPa. Glycerol hydrogenolysis to produce 1,2-PDO via C―O cleavage (i) proceeds with parallel C—C cleavage, reforming, water-gas shift, and Fischer-Tropsch reactions, (ii) results in a very complex reaction network with several gaseous- and liquid-phase products, and (iii) poses a challenge to design selective catalysts. It is observed that Ru―Re bimetallic catalyst shows higher hydrogenolysis activity (glycerol conversion of X = 57.7%) and 1,2-PDO selectivity (S = 36.6%), compared to the monometallic Ru catalyst (X = 52.1%; S = 18.9%) but the monometallic Re catalyst showed no catalytic activity for the reaction. Stirred-batch reactor data on the transient concentrations of reactants and products in both the gas and liquid phases were obtained using a bimetallic Ru-Re/C catalyst under different conditions to understand the reaction pathways, selectivity behavior, and intrinsic kinetics of the different reaction steps. For kinetic modeling, several experiments were performed at different initial pressures of hydrogen, catalyst concentration, and temperatures. The proposed rate equations, along with the regressed kinetic and activation energy parameters, were found to represent the experimental data for the multistep hydrogenolysis reaction very satisfactorily. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23447975

Supercritical deoxygenation of a model bio - oil oxygenate / Jackson W. Ford 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. 10852–10858 Titre : Supercritical deoxygenation of a model bio - oil oxygenate Type de document : texte imprimé Auteurs : Jackson W. Ford, Auteur ; Raghunath V. Chaudhari, Auteur ; Bala Subramaniam, Auteur Année de publication : 2011 Article en page(s) : pp. 10852–10858 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Deoxygenation  Oil Résumé : A novel process for the fixed-bed deoxygenation of a model bio-oil compound in supercritical media at mild pressures (tens of bars) is presented. As an example, nonanal deoxygenation over Pt/Al2O3 catalyst in supercritical n-hexane (Tc = 234.45 °C, Pc = 30.2 bar) with excess hydrogen (molar H2/nonanol in feed = 57) at 300 °C provides steady conversions of approximately 60% over a pressure range of 7−80 bar with approximately 40% selectivity to C8 and C9 hydrocarbons, at liquid hourly space velocities of 80 g nonanal·(g Pt)−1·h−1. Further, the conversions display only a mild temperature dependence. This suggests that for the conditions under study, the reaction is limited by mass transfer of nonanal (limiting reactant) from the bulk fluid phase to the catalyst particle. Among the alkanes, the selectivity to the decarbonylation product (n-octane) is higher at all pressures relative to the hydrogention product (n-nonane). However, the selectivities toward nonane and nonanol increase relative to the decarbonylation product (n-octane) at higher reactor pressures, attributed to the enhanced hydrogen partial pressures at supercritical conditions. Effective rate constants, estimated from a simple isothermal packed-bed reactor model that assumes first-order dependence on nonanal concentration, decrease exponentially as the pressure is tuned from subcritical pressures (gaslike properties) to supercritical pressures (liquidlike properties). This decrease is characteristic of the pressure dependence of the external mass transfer coefficient. Mass transfer coefficients, predicted using published correlations, are of the same order of magnitude as the effective rate constants, further affirming that the measured reaction rates are controlled by external mass transfer. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1005492 [article] Supercritical deoxygenation of a model bio - oil oxygenate [texte imprimé] / Jackson W. Ford, Auteur ; Raghunath V. Chaudhari, Auteur ; Bala Subramaniam, Auteur . - 2011 . - pp. 10852–10858. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 21 (Novembre 2010) . - pp. 10852–10858 Mots-clés : Deoxygenation  Oil Résumé : A novel process for the fixed-bed deoxygenation of a model bio-oil compound in supercritical media at mild pressures (tens of bars) is presented. As an example, nonanal deoxygenation over Pt/Al2O3 catalyst in supercritical n-hexane (Tc = 234.45 °C, Pc = 30.2 bar) with excess hydrogen (molar H2/nonanol in feed = 57) at 300 °C provides steady conversions of approximately 60% over a pressure range of 7−80 bar with approximately 40% selectivity to C8 and C9 hydrocarbons, at liquid hourly space velocities of 80 g nonanal·(g Pt)−1·h−1. Further, the conversions display only a mild temperature dependence. This suggests that for the conditions under study, the reaction is limited by mass transfer of nonanal (limiting reactant) from the bulk fluid phase to the catalyst particle. Among the alkanes, the selectivity to the decarbonylation product (n-octane) is higher at all pressures relative to the hydrogention product (n-nonane). However, the selectivities toward nonane and nonanol increase relative to the decarbonylation product (n-octane) at higher reactor pressures, attributed to the enhanced hydrogen partial pressures at supercritical conditions. Effective rate constants, estimated from a simple isothermal packed-bed reactor model that assumes first-order dependence on nonanal concentration, decrease exponentially as the pressure is tuned from subcritical pressures (gaslike properties) to supercritical pressures (liquidlike properties). This decrease is characteristic of the pressure dependence of the external mass transfer coefficient. Mass transfer coefficients, predicted using published correlations, are of the same order of magnitude as the effective rate constants, further affirming that the measured reaction rates are controlled by external mass transfer. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1005492