Documents disponibles écrits par cet auteur

Application of a combined catalyst and sorbent for steam reforming of methane / Karl O. Albrecht 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. 4091–4098 Titre : Application of a combined catalyst and sorbent for steam reforming of methane Type de document : texte imprimé Auteurs : Karl O. Albrecht, Auteur ; Justinus A. Satrio, Auteur ; Brent H. Shanks, Auteur Année de publication : 2010 Article en page(s) : pp. 4091–4098 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Catalyst  Methane Résumé : The performance of a combined catalyst and sorbent material designed for reforming hydrocarbons was evaluated by reacting methane with steam at different temperatures and pressures in a reactor packed with the material. The combined material was in the form of small spherical pellets comprised of a sorbent core of lime encased in a porous shell made largely of sintered alumina that supported a nickel catalyst. On the basis of previous research, two shell formulations were included in the study. One shell formulation contained a small quantity of CaO for strengthening of the shells, whereas the other contained a similar quantity of La2O3. Reaction testing of the combined catalyst and sorbent over a temperature range of 550−650 °C and a pressure range of 1.0−10.0 atm showed that pellets with either shell formulation were capable of producing H2 at or near thermodynamic equilibrium levels during a period when CO2 was being rapidly absorbed by the core material. Limited lifecycle testing of the combined catalyst and sorbent was also conducted at 650 °C and 1.0 atm over 10 cycles of H2 production and sorbent regeneration. A product stream with 98 mol % H2 (dry basis) was produced during the rapid CO2 absorption period of each cycle. However, the length of this period declined with each cycle. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901914c [article] Application of a combined catalyst and sorbent for steam reforming of methane [texte imprimé] / Karl O. Albrecht, Auteur ; Justinus A. Satrio, Auteur ; Brent H. Shanks, Auteur . - 2010 . - pp. 4091–4098. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 9 (Mai 2010) . - pp. 4091–4098 Mots-clés : Catalyst  Methane Résumé : The performance of a combined catalyst and sorbent material designed for reforming hydrocarbons was evaluated by reacting methane with steam at different temperatures and pressures in a reactor packed with the material. The combined material was in the form of small spherical pellets comprised of a sorbent core of lime encased in a porous shell made largely of sintered alumina that supported a nickel catalyst. On the basis of previous research, two shell formulations were included in the study. One shell formulation contained a small quantity of CaO for strengthening of the shells, whereas the other contained a similar quantity of La2O3. Reaction testing of the combined catalyst and sorbent over a temperature range of 550−650 °C and a pressure range of 1.0−10.0 atm showed that pellets with either shell formulation were capable of producing H2 at or near thermodynamic equilibrium levels during a period when CO2 was being rapidly absorbed by the core material. Limited lifecycle testing of the combined catalyst and sorbent was also conducted at 650 °C and 1.0 atm over 10 cycles of H2 production and sorbent regeneration. A product stream with 98 mol % H2 (dry basis) was produced during the rapid CO2 absorption period of each cycle. However, the length of this period declined with each cycle. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901914c

Conversion of biorenewable feedstocks / Brent H. Shanks 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. 10212-10217 Titre : Conversion of biorenewable feedstocks : New challenges in heterogeneous catalysis Type de document : texte imprimé Auteurs : Brent H. Shanks, Auteur Année de publication : 2011 Article en page(s) : pp. 10212-10217 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Heterogeneous  catalysis Résumé : For biorenewable feedstocks to serve as a significant source of chemicals and/or fuels, the development of new chemical processes as well as biological processes will be required. However, the conversion of biorenewable feedstocks with heterogeneous catalyst-based processes provides new challenges in inorganic catalyst research and development relative to historical work with petrochemical feedstocks. These catalyst and process challenges include the need to convert highly functionalized molecules with high selectivity, to develop stable catalytic liquid—solid interfaces in which the liquid phase is commonly aqueous, to control solvent phase effects and to develop novel reaction systems. While some of these challenges will be addressed using novel catalytic materials, others will need to be overcome through design of new catalytic reaction systems. Examples of emerging research results demonstrating unique approaches that have been taken to begin to address the efficient conversion of biorenewable feedstocks to chemicals and fuels are discussed. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23447909 [article] Conversion of biorenewable feedstocks : New challenges in heterogeneous catalysis [texte imprimé] / Brent H. Shanks, Auteur . - 2011 . - pp. 10212-10217. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 21 (Novembre 2010) . - pp. 10212-10217 Mots-clés : Heterogeneous  catalysis Résumé : For biorenewable feedstocks to serve as a significant source of chemicals and/or fuels, the development of new chemical processes as well as biological processes will be required. However, the conversion of biorenewable feedstocks with heterogeneous catalyst-based processes provides new challenges in inorganic catalyst research and development relative to historical work with petrochemical feedstocks. These catalyst and process challenges include the need to convert highly functionalized molecules with high selectivity, to develop stable catalytic liquid—solid interfaces in which the liquid phase is commonly aqueous, to control solvent phase effects and to develop novel reaction systems. While some of these challenges will be addressed using novel catalytic materials, others will need to be overcome through design of new catalytic reaction systems. Examples of emerging research results demonstrating unique approaches that have been taken to begin to address the efficient conversion of biorenewable feedstocks to chemicals and fuels are discussed. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=23447909

Effect of electrolytes on CO-water mass transfer / Haiyang Zhu in Industrial & engineering chemistry research, Vol. 48 N° 6 (Mars 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 6 (Mars 2009) . - pp. 3206–3210 Titre : Effect of electrolytes on CO-water mass transfer Type de document : texte imprimé Auteurs : Haiyang Zhu, Auteur ; Brent H. Shanks, Auteur ; Heindel, Theodore J., Auteur Année de publication : 2009 Article en page(s) : pp. 3206–3210 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Electrolytes  CO-water  mass  transfer  Mass-transfer  coefficient  MCM41  nanoparticles Résumé : The influence of various electrolytes such as sulfate, nitrate, and chloride on CO−water mass transfer was investigated in this study. The results indicate that the enhancement in the CO−water volumetric mass-transfer coefficient ranged from 1.5 to 4.7 times that of a baseline system without electrolytes, depending on electrolyte type and concentration. For those electrolytes with the same anions, copper-containing electrolytes provided stronger enhancement, whereas for those electrolytes with the same cations, sulfate-containing electrolytes showed stronger enhancement. By measuring both the CO−water volumetric mass-transfer coefficient (kLa) and the mass-transfer coefficient (kL), it was found that the electrolytes inhibit gas bubble coalescence. This leads to an increase in the gas−liquid interfacial area, resulting in CO−water mass-transfer enhancement. In contrast, when MCM41 nanoparticles with or without functionalized mercaptopropyl groups were added to water, the mass-transfer coefficient and CO−water interfacial area were both increased. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8012924 [article] Effect of electrolytes on CO-water mass transfer [texte imprimé] / Haiyang Zhu, Auteur ; Brent H. Shanks, Auteur ; Heindel, Theodore J., Auteur . - 2009 . - pp. 3206–3210. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 6 (Mars 2009) . - pp. 3206–3210 Mots-clés : Electrolytes  CO-water  mass  transfer  Mass-transfer  coefficient  MCM41  nanoparticles Résumé : The influence of various electrolytes such as sulfate, nitrate, and chloride on CO−water mass transfer was investigated in this study. The results indicate that the enhancement in the CO−water volumetric mass-transfer coefficient ranged from 1.5 to 4.7 times that of a baseline system without electrolytes, depending on electrolyte type and concentration. For those electrolytes with the same anions, copper-containing electrolytes provided stronger enhancement, whereas for those electrolytes with the same cations, sulfate-containing electrolytes showed stronger enhancement. By measuring both the CO−water volumetric mass-transfer coefficient (kLa) and the mass-transfer coefficient (kL), it was found that the electrolytes inhibit gas bubble coalescence. This leads to an increase in the gas−liquid interfacial area, resulting in CO−water mass-transfer enhancement. In contrast, when MCM41 nanoparticles with or without functionalized mercaptopropyl groups were added to water, the mass-transfer coefficient and CO−water interfacial area were both increased. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie8012924

Enhancing CO-water mass transfer by functionalized MCM41 nanoparticles / Haiyang Zhu 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. 7881-7887 Titre : Enhancing CO-water mass transfer by functionalized MCM41 nanoparticles Type de document : texte imprimé Auteurs : Haiyang Zhu, Auteur ; Brent H. Shanks, Auteur ; Heindel, Theodore J., Auteur Année de publication : 2008 Article en page(s) : P. 7881-7887 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : CO-Water  Gas Résumé : Organic groups are grafted to ∼250-nm-diameter MCM41 nanoparticles with a spherical morphology to enhance the CO−water volumetric mass-transfer coefficient (kLa) for synthesis gas fermentation. The results indicate that (i) ∼250-nm MCM41 nanoparticles show a higher kLa value than large silica particles (1.4 and 7 μm), (ii) surface hydroxyl groups on MCM41 nanoparticles play an important role in mass-transfer enhancement, (iii) organic groups grafted to MCM41 modify the mass-transfer enhancement, and (iv) mercaptan groups grafted to MCM41 show the most mass-transfer enhancement of ∼1.9 times that of no nanoparticle addition. The CO−water mass-transfer enhancement depends on the interaction between the nanoparticles and the CO molecules, which is influenced by the hydrophobicity of the nanoparticles and the functional group on the nanoparticles. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800238w [article] Enhancing CO-water mass transfer by functionalized MCM41 nanoparticles [texte imprimé] / Haiyang Zhu, Auteur ; Brent H. Shanks, Auteur ; Heindel, Theodore J., Auteur . - 2008 . - P. 7881-7887. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N°20 (Octobre 2008) . - P. 7881-7887 Mots-clés : CO-Water  Gas Résumé : Organic groups are grafted to ∼250-nm-diameter MCM41 nanoparticles with a spherical morphology to enhance the CO−water volumetric mass-transfer coefficient (kLa) for synthesis gas fermentation. The results indicate that (i) ∼250-nm MCM41 nanoparticles show a higher kLa value than large silica particles (1.4 and 7 μm), (ii) surface hydroxyl groups on MCM41 nanoparticles play an important role in mass-transfer enhancement, (iii) organic groups grafted to MCM41 modify the mass-transfer enhancement, and (iv) mercaptan groups grafted to MCM41 show the most mass-transfer enhancement of ∼1.9 times that of no nanoparticle addition. The CO−water mass-transfer enhancement depends on the interaction between the nanoparticles and the CO molecules, which is influenced by the hydrophobicity of the nanoparticles and the functional group on the nanoparticles. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800238w

Improving the stability of a CaO-based sorbent for CO2 by thermal pretreatment / Dursun Can Ozcan in Industrial & engineering chemistry research, Vol. 50 N° 11 (Juin 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6933-6942 Titre : Improving the stability of a CaO-based sorbent for CO2 by thermal pretreatment Type de document : texte imprimé Auteurs : Dursun Can Ozcan, Auteur ; Brent H. Shanks, Auteur ; Thomas D. Wheelock, Auteur Année de publication : 2011 Article en page(s) : pp. 6933-6942 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Pretreatment  Carbon  dioxide  Stability Résumé : Although the reversible absorption of CO2 by CaO at high temperature has been proposed as a promising method for capturing and removing CO2 from hot gas streams produced by the combustion of fossil fuels and other industrial processes, the activity of the sorbent has invariably declined when applied over many cycles of CO2 absorption and desorption. The objective of the present investigation was to extend the life cycle performance of the absorbent through improved thermal pretreatment as the absorbent was prepared from limestone, dolomite, calcium acetate, or plaster of Paris. The first three materials were converted to CaO by calcination, while the third being an impure form of CaSO4 required a combination of reduction and oxidation. The life cycle performance of an absorbent derived by calcination was found to depend on the calcination conditions including particle size, temperature, atmosphere, and length of treatment. Sorbent stability was favored by calcining fine-size particles (10 μm) at high temperature (1000 °C) in an atmosphere containing 50% CO2 or more. The sorbent derived from plaster of Paris by a cyclic process of reduction and oxidation at 1070 °C proved to be a very unusual material when applied because its activity increased rapidly and was still increasing after 200 cycles of absorption and regeneration. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199911 [article] Improving the stability of a CaO-based sorbent for CO2 by thermal pretreatment [texte imprimé] / Dursun Can Ozcan, Auteur ; Brent H. Shanks, Auteur ; Thomas D. Wheelock, Auteur . - 2011 . - pp. 6933-6942. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 11 (Juin 2011) . - pp. 6933-6942 Mots-clés : Pretreatment  Carbon  dioxide  Stability Résumé : Although the reversible absorption of CO2 by CaO at high temperature has been proposed as a promising method for capturing and removing CO2 from hot gas streams produced by the combustion of fossil fuels and other industrial processes, the activity of the sorbent has invariably declined when applied over many cycles of CO2 absorption and desorption. The objective of the present investigation was to extend the life cycle performance of the absorbent through improved thermal pretreatment as the absorbent was prepared from limestone, dolomite, calcium acetate, or plaster of Paris. The first three materials were converted to CaO by calcination, while the third being an impure form of CaSO4 required a combination of reduction and oxidation. The life cycle performance of an absorbent derived by calcination was found to depend on the calcination conditions including particle size, temperature, atmosphere, and length of treatment. Sorbent stability was favored by calcining fine-size particles (10 μm) at high temperature (1000 °C) in an atmosphere containing 50% CO2 or more. The sorbent derived from plaster of Paris by a cyclic process of reduction and oxidation at 1070 °C proved to be a very unusual material when applied because its activity increased rapidly and was still increasing after 200 cycles of absorption and regeneration. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24199911