Documents disponibles écrits par cet auteur

3D Simulation of bubbling fluidized bed reactors for sorption enhanced steam methane reforming processes / Yuefa Wang in Journal of natural gas science and engineering, Vol. 2 N° 2-3 (Juillet 2010) 

Public ISBD [article]  in Journal of natural gas science and engineering > Vol. 2 N° 2-3 (Juillet 2010) . - pp. 105–113 Titre : 3D Simulation of bubbling fluidized bed reactors for sorption enhanced steam methane reforming processes Type de document : texte imprimé Auteurs : Yuefa Wang, Auteur ; Zhongxi Chao, Auteur ; Hugo A. Jakobsen, Auteur Année de publication : 2012 Article en page(s) : pp. 105–113 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Methane  reforming  Carbon  dioxide  capture  SE-SMR  CaO  sorbent  3D  simulation  Fluidized  bed Résumé : Hydrogen production by the Sorption Enhanced Steam Methane Reforming (SE-SMR) process was studied with a numerical two-fluid model. The process was simulated in a three dimensional bubbling fluidized bed reactor. The effects of pressure, steam-to-carbon ratio and inlet gas flow rate on the reactions are studied. High pressure and low steam-to-carbon ratio will decrease the conversion of methane. But the high pressure makes the adsorption of CO2 faster. Compared to the standard SMR process, the methane conversion and heat utility are enhanced by CO2 adsorption. The CO2 produced in the methane reforming process is adsorbed almost totally in a relative long period of time in the bubbling fluidized bed. It means that the adsorption rate of CO2 is fast enough compared with the SMR rate. In a certain range of gas flow rates, the mass transfer and reaction kinetics can reach the equilibrium, and the reaction efficiency is independent of gas flow rate. The temperature distribution is almost uniform over the whole reactor. ISSN : 1875-5100 En ligne : http://www.sciencedirect.com/science/article/pii/S1875510010000302 [article] 3D Simulation of bubbling fluidized bed reactors for sorption enhanced steam methane reforming processes [texte imprimé] / Yuefa Wang, Auteur ; Zhongxi Chao, Auteur ; Hugo A. Jakobsen, Auteur . - 2012 . - pp. 105–113. Génie Chimique Langues : Anglais (eng) in Journal of natural gas science and engineering > Vol. 2 N° 2-3 (Juillet 2010) . - pp. 105–113 Mots-clés : Methane  reforming  Carbon  dioxide  capture  SE-SMR  CaO  sorbent  3D  simulation  Fluidized  bed Résumé : Hydrogen production by the Sorption Enhanced Steam Methane Reforming (SE-SMR) process was studied with a numerical two-fluid model. The process was simulated in a three dimensional bubbling fluidized bed reactor. The effects of pressure, steam-to-carbon ratio and inlet gas flow rate on the reactions are studied. High pressure and low steam-to-carbon ratio will decrease the conversion of methane. But the high pressure makes the adsorption of CO2 faster. Compared to the standard SMR process, the methane conversion and heat utility are enhanced by CO2 adsorption. The CO2 produced in the methane reforming process is adsorbed almost totally in a relative long period of time in the bubbling fluidized bed. It means that the adsorption rate of CO2 is fast enough compared with the SMR rate. In a certain range of gas flow rates, the mass transfer and reaction kinetics can reach the equilibrium, and the reaction efficiency is independent of gas flow rate. The temperature distribution is almost uniform over the whole reactor. ISSN : 1875-5100 En ligne : http://www.sciencedirect.com/science/article/pii/S1875510010000302

Effects of gas-solid hydrodynamic behavior on the reactions of the sorption enhanced steam methane reforming process in bubbling fluidized bed reactors / Yuefa Wang in Industrial & engineering chemistry research, Vol. 50 N° 14 (Juillet 2011) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 50 N° 14 (Juillet 2011) . - pp. 8430-8437 Titre : Effects of gas-solid hydrodynamic behavior on the reactions of the sorption enhanced steam methane reforming process in bubbling fluidized bed reactors Type de document : texte imprimé Auteurs : Yuefa Wang, Auteur ; Zhongxi Chao, Auteur ; Hugo A. Jakobsen, Auteur Année de publication : 2011 Article en page(s) : pp. 8430-8437 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Fluidized  bed  reactor  Bubbling  Reforming  Water  vapor  Sorption  Hydrodynamics  Gas  solid Résumé : A three-dimensional two-fluid modeling approach with the kinetic theory of granular flow was used to study the process of sorption enhanced steam methane reforming (SE-SMR) carried out in a bubbling fluidized bed reactor. The effects of the superficial gas velocity and restitution coefficient on the solid flow pattern and reactions were investigated. The hydrodynamic properties of the reactive flow showed different behaviors compared to the cold flow. The superficial gas velocity and restitution coefficient influence the bed expansion and bed uniformity in different ways. The reactions ofSE-SMR were affected mainly by the superficial gas velocity, while the restitution coefficient has a smaller influence on the reactions. The CO2 adsorption is a faster reaction than the SMR reactions. A uniform bed state will be of more benefit to slow reactions than to fast reactions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24346883 [article] Effects of gas-solid hydrodynamic behavior on the reactions of the sorption enhanced steam methane reforming process in bubbling fluidized bed reactors [texte imprimé] / Yuefa Wang, Auteur ; Zhongxi Chao, Auteur ; Hugo A. Jakobsen, Auteur . - 2011 . - pp. 8430-8437. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 50 N° 14 (Juillet 2011) . - pp. 8430-8437 Mots-clés : Fluidized  bed  reactor  Bubbling  Reforming  Water  vapor  Sorption  Hydrodynamics  Gas  solid Résumé : A three-dimensional two-fluid modeling approach with the kinetic theory of granular flow was used to study the process of sorption enhanced steam methane reforming (SE-SMR) carried out in a bubbling fluidized bed reactor. The effects of the superficial gas velocity and restitution coefficient on the solid flow pattern and reactions were investigated. The hydrodynamic properties of the reactive flow showed different behaviors compared to the cold flow. The superficial gas velocity and restitution coefficient influence the bed expansion and bed uniformity in different ways. The reactions ofSE-SMR were affected mainly by the superficial gas velocity, while the restitution coefficient has a smaller influence on the reactions. The CO2 adsorption is a faster reaction than the SMR reactions. A uniform bed state will be of more benefit to slow reactions than to fast reactions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24346883

Mass conservative solution of the population balance equation using the least-squares spectral element method / Zhengjie Zhu in Industrial & engineering chemistry research, Vol. 49 N° 13 (Juillet 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 13 (Juillet 2010) . - pp. 6204–6214 Titre : Mass conservative solution of the population balance equation using the least-squares spectral element method Type de document : texte imprimé Auteurs : Zhengjie Zhu, Auteur ; Carlos A. Dorao, Auteur ; Hugo A. Jakobsen, Auteur Année de publication : 2010 Article en page(s) : pp. 6204–6214 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Population  balance  equation  Mass  loss Résumé : In the standard formulation of the population balance equation that consists of breakage terms, significant loss of mass is observed for the dispersed phase. This mass loss is actually caused by the inexact conservation property reflected by many breakage kernels; hence, incorrect physical interpretations of the model simulations may be drawn. In this work, a constrained method is developed enforcing mass conservation. This numerical property is accomplished by adding an extra restriction to the original population balance equation in terms of the dispersed phase continuity equation through the Lagrange multipliers strategy. The discretized system resulting from applying the method to a two-phase population balance equation problem is symmetric and pseudopositive definite. Numerical experiments are carried out simulating the motion of a two-phase mixture passing through a 2D domain. The results obtained by the modified least-squares spectral element method show that the mass is conserved everywhere in the domain with high accuracy. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900710y [article] Mass conservative solution of the population balance equation using the least-squares spectral element method [texte imprimé] / Zhengjie Zhu, Auteur ; Carlos A. Dorao, Auteur ; Hugo A. Jakobsen, Auteur . - 2010 . - pp. 6204–6214. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 13 (Juillet 2010) . - pp. 6204–6214 Mots-clés : Population  balance  equation  Mass  loss Résumé : In the standard formulation of the population balance equation that consists of breakage terms, significant loss of mass is observed for the dispersed phase. This mass loss is actually caused by the inexact conservation property reflected by many breakage kernels; hence, incorrect physical interpretations of the model simulations may be drawn. In this work, a constrained method is developed enforcing mass conservation. This numerical property is accomplished by adding an extra restriction to the original population balance equation in terms of the dispersed phase continuity equation through the Lagrange multipliers strategy. The discretized system resulting from applying the method to a two-phase population balance equation problem is symmetric and pseudopositive definite. Numerical experiments are carried out simulating the motion of a two-phase mixture passing through a 2D domain. The results obtained by the modified least-squares spectral element method show that the mass is conserved everywhere in the domain with high accuracy. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900710y

On the Consistent Modeling of Porous Catalyst Pellets / Jannike Solsvik in Industrial & engineering chemistry research, Vol. 51 N° 24 (Juin 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8222-8236 Titre : On the Consistent Modeling of Porous Catalyst Pellets : Mass and Molar Formulations Type de document : texte imprimé Auteurs : Jannike Solsvik, Auteur ; Stian Tangen, Auteur ; Hugo A. Jakobsen, Auteur Année de publication : 2012 Article en page(s) : pp. 8222-8236 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Pellet  Catalyst  Modeling Résumé : Accurate modeling ofintrapartide heat and mass transport is a prerequisite for the design of many industrial processes and the interpretation of experiments. In the recent literature, deviations are noticed between simulation results of mole and mass formulated pellet model equations. For this reason, in this study, a comprehensive mathematical and numerical analysis has been performed. Several pellet model complexities are simulated to elucidate the effects of modeling assumptions on the behavior of the mass and mole formulated pellet model equations. Noted findings are as follows: (i) The simulation results show that the Wilke and Wilke-Bosanquet models with respect to the mass and mole average velocity definitions are not consistent. The Maxwell―Stefan and dusty gas closures are recommended; identical simulation results can be obtained with the mass and mole formulated pellet equations where the species mole and mass diffusion fluxes are defined relative to the respective average mixture velocities. (ii) Considering simplified models in which the convective terms are neglected, the species mole balance should be manipulated with the continuity equation to enforce the continuity balance of the mole number change. For the rigorous models retaining the convective terms, model manipulation by use of the continuity equation is still beneficial simplifying the model complexity and thus the implementation. Moreover, it is important to identify the velocity definitions used in the pellet equations and apply them consistently. DEWEY : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26029657 [article] On the Consistent Modeling of Porous Catalyst Pellets : Mass and Molar Formulations [texte imprimé] / Jannike Solsvik, Auteur ; Stian Tangen, Auteur ; Hugo A. Jakobsen, Auteur . - 2012 . - pp. 8222-8236. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 24 (Juin 2012) . - pp. 8222-8236 Mots-clés : Pellet  Catalyst  Modeling Résumé : Accurate modeling ofintrapartide heat and mass transport is a prerequisite for the design of many industrial processes and the interpretation of experiments. In the recent literature, deviations are noticed between simulation results of mole and mass formulated pellet model equations. For this reason, in this study, a comprehensive mathematical and numerical analysis has been performed. Several pellet model complexities are simulated to elucidate the effects of modeling assumptions on the behavior of the mass and mole formulated pellet model equations. Noted findings are as follows: (i) The simulation results show that the Wilke and Wilke-Bosanquet models with respect to the mass and mole average velocity definitions are not consistent. The Maxwell―Stefan and dusty gas closures are recommended; identical simulation results can be obtained with the mass and mole formulated pellet equations where the species mole and mass diffusion fluxes are defined relative to the respective average mixture velocities. (ii) Considering simplified models in which the convective terms are neglected, the species mole balance should be manipulated with the continuity equation to enforce the continuity balance of the mole number change. For the rigorous models retaining the convective terms, model manipulation by use of the continuity equation is still beneficial simplifying the model complexity and thus the implementation. Moreover, it is important to identify the velocity definitions used in the pellet equations and apply them consistently. DEWEY : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26029657

A sensitivity study of the two-fluid model closure parameters (β, e) determining the main gas−solid flow pattern characteristics / Yuefa Wang in Industrial & engineering chemistry research, Vol. 49 N° 7 (Avril 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 7 (Avril 2010) . - pp. 3433–3441 Titre : A sensitivity study of the two-fluid model closure parameters (β, e) determining the main gas−solid flow pattern characteristics Type de document : texte imprimé Auteurs : Yuefa Wang, Auteur ; Zhongxi Chao, Auteur ; Hugo A. Jakobsen, Auteur Année de publication : 2010 Article en page(s) : pp. 3433–3441 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Sensitivity  Two-Fluid  Model  Closure  Parameters  Main  Gas−Solid  Flow  (β,  e) Résumé : The closures determining the interactions of particle−particle and gas−particle are very important for gas−solid flow. A three-dimensional two-fluid modeling approach with the kinetic theory of granular flow is used to simulate the hydrodynamic behaviors of a bubbling fluidized bed and a circulating fluidized bed. The influences of the coefficient of restitution and the drag model on the flow pattern are studied. The simulation results for bubbling beds are compared with the experimental results of Lin et al.(1) It is found that the coefficient of restitution has strong influence on the flow pattern of the particle phase in bubbling beds. A relationship between the coefficient of restitution and the superficial inlet velocity is correlated. The effects of restitution coefficient on the distribution of solid phase in the circulating fluidized beds were also studied. In this case, the influence of the coefficient of restitution is weaker than for bubbling fluidized beds. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901314u [article] A sensitivity study of the two-fluid model closure parameters (β, e) determining the main gas−solid flow pattern characteristics [texte imprimé] / Yuefa Wang, Auteur ; Zhongxi Chao, Auteur ; Hugo A. Jakobsen, Auteur . - 2010 . - pp. 3433–3441. Industrial Chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 7 (Avril 2010) . - pp. 3433–3441 Mots-clés : Sensitivity  Two-Fluid  Model  Closure  Parameters  Main  Gas−Solid  Flow  (β,  e) Résumé : The closures determining the interactions of particle−particle and gas−particle are very important for gas−solid flow. A three-dimensional two-fluid modeling approach with the kinetic theory of granular flow is used to simulate the hydrodynamic behaviors of a bubbling fluidized bed and a circulating fluidized bed. The influences of the coefficient of restitution and the drag model on the flow pattern are studied. The simulation results for bubbling beds are compared with the experimental results of Lin et al.(1) It is found that the coefficient of restitution has strong influence on the flow pattern of the particle phase in bubbling beds. A relationship between the coefficient of restitution and the superficial inlet velocity is correlated. The effects of restitution coefficient on the distribution of solid phase in the circulating fluidized beds were also studied. In this case, the influence of the coefficient of restitution is weaker than for bubbling fluidized beds. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901314u

Sorption enhanced steam methane reforming process performance and bubbling fluidized bed reactor design analysis by use of a two-fluid model / Håvard Lindborg in Industrial & engineering chemistry research, Vol. 48 N°3 (Février 2009) 

Permalink