Documents disponibles écrits par cet auteur

CO2 Sequestration in chrysotile mining residues — implication of watering and passivation under environmental conditions / Gnouyaro P. Assima in Industrial & engineering chemistry research, Vol. 51 N° 26 (Juillet 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 26 (Juillet 2012) . - pp 8726–8734 Titre : CO2 Sequestration in chrysotile mining residues — implication of watering and passivation under environmental conditions Type de document : texte imprimé Auteurs : Gnouyaro P. Assima, Auteur ; Faïçal Larachi, Auteur ; Georges Beaudoin, Auteur Année de publication : 2012 Article en page(s) : pp 8726–8734 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Chrysotile  Mining  Residues Résumé : Factors affecting carbon dioxide fixation in chrysotile mining residues (CMR) under environmental conditions were studied by reproducing mineral dissolution and carbonation in laboratory columns packed with CMR particles. Carbonation is very sensitive to water saturation and watering frequency of the CMR porous media. CO2 uptake by dry residues subjected to dry CO2 flow for several days at ambient temperature was below 0.02%. However, an increase by a factor of 20 in CO2 uptake was achieved by periodic addition of small amounts of water with respect to a moistened CO2 stream over dry CMR samples. The highest MgCO3 conversion resulted in nearly 22 mg of CO2 captured per gram of residue, revealing that up to 93% of Mg remained noncarbonated because of surface obstructing processes. Magnesium leaching from CMR was hindered by two concomitant passivation phenomena limiting the residue’s CO2 storage capacity. A unique cyclic voltammetry technique using oxic and anoxic aqueous solutions contacted with CMR fixed beds was implemented to assess the relative importance from CMR-borne iron electrochemical passivation and silica-deposit nonelectrochemical passivation. Passivation around the dissolving CMR particles by iron hydroxide precipitation was found to develop very rapidly in comparison to silica gel polymerization. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202693q [article] CO2 Sequestration in chrysotile mining residues — implication of watering and passivation under environmental conditions [texte imprimé] / Gnouyaro P. Assima, Auteur ; Faïçal Larachi, Auteur ; Georges Beaudoin, Auteur . - 2012 . - pp 8726–8734. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 26 (Juillet 2012) . - pp 8726–8734 Mots-clés : Chrysotile  Mining  Residues Résumé : Factors affecting carbon dioxide fixation in chrysotile mining residues (CMR) under environmental conditions were studied by reproducing mineral dissolution and carbonation in laboratory columns packed with CMR particles. Carbonation is very sensitive to water saturation and watering frequency of the CMR porous media. CO2 uptake by dry residues subjected to dry CO2 flow for several days at ambient temperature was below 0.02%. However, an increase by a factor of 20 in CO2 uptake was achieved by periodic addition of small amounts of water with respect to a moistened CO2 stream over dry CMR samples. The highest MgCO3 conversion resulted in nearly 22 mg of CO2 captured per gram of residue, revealing that up to 93% of Mg remained noncarbonated because of surface obstructing processes. Magnesium leaching from CMR was hindered by two concomitant passivation phenomena limiting the residue’s CO2 storage capacity. A unique cyclic voltammetry technique using oxic and anoxic aqueous solutions contacted with CMR fixed beds was implemented to assess the relative importance from CMR-borne iron electrochemical passivation and silica-deposit nonelectrochemical passivation. Passivation around the dissolving CMR particles by iron hydroxide precipitation was found to develop very rapidly in comparison to silica gel polymerization. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202693q

Cyclic operation strategies in trickle beds and electrical capacitance tomography imaging of filtration dynamics / Mohsen Hamidipour in Industrial & engineering chemistry research, Vol. 49 N° 3 (Fevrier 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 3 (Fevrier 2010) . - pp. 934–952 Titre : Cyclic operation strategies in trickle beds and electrical capacitance tomography imaging of filtration dynamics Type de document : texte imprimé Auteurs : Mohsen Hamidipour, Auteur ; Faïçal Larachi, Auteur ; Zbigniew Ring, Auteur Année de publication : 2010 Article en page(s) : pp. 934–952 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Cyclic--Trickle  Beds--Electrical  Capacitance--Tomography--Imaging--Filtration  Dynamics Résumé : The dynamics of propagating liquid pulsations generated via various cyclic operation strategies in trickle beds was monitored through electrical capacitance tomography (ECT) for gas and liquid superficial velocities in the range of trickle flow regime. The characteristics of ON−OFF liquid, ON−OFF gas, and gas/liquid alternating cyclic operations were compared in terms of mean liquid holdup, pressure drop, pulsation intensity, pulsation propagation velocity, and spatial maldistribution maps of liquid holdup and liquid pulsation propagation velocity. The morphological features of liquid holdup pulsations as a function of cycle frequency were characterized in terms of breakthrough, plateau, and decay times. Gas/liquid alternating cyclic strategy was shown to produce long-lived liquid pulsations under the applied operating conditions and thus could be viewed as a new process intensification means to achieve uniform phase holdup and velocity distributions. In ON−OFF liquid cyclic operation, pulsation velocity did not increase along the bed unlike the ON−OFF gas and gas/liquid alternating cyclic modes where increased pulsation velocities were able to give rise to pulse flow regime. The gas/liquid alternating cyclic operation resulted in the shortest breakthrough and decay times and the longest plateau time, thus approaching the ideal square-shaped inlet pulsations for symmetrical splits. ECT imaging was also used to scrutinize the dynamics of local deposition of fines in trickle beds fed with kaolin suspensions under the three cyclic operations. Data revealed that applying ON−OFF gas and gas/liquid alternating cyclic methods resulted in significant reduction of fines deposition. This suggests new practical solutions for possible industrial implementation of self-cleaning modulation strategies of trickle beds subject to unwanted filtration during suspension flows. Note de contenu : Bibiogr. ISSN : 0885-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900605b [article] Cyclic operation strategies in trickle beds and electrical capacitance tomography imaging of filtration dynamics [texte imprimé] / Mohsen Hamidipour, Auteur ; Faïçal Larachi, Auteur ; Zbigniew Ring, Auteur . - 2010 . - pp. 934–952. Industrial Chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 3 (Fevrier 2010) . - pp. 934–952 Mots-clés : Cyclic--Trickle  Beds--Electrical  Capacitance--Tomography--Imaging--Filtration  Dynamics Résumé : The dynamics of propagating liquid pulsations generated via various cyclic operation strategies in trickle beds was monitored through electrical capacitance tomography (ECT) for gas and liquid superficial velocities in the range of trickle flow regime. The characteristics of ON−OFF liquid, ON−OFF gas, and gas/liquid alternating cyclic operations were compared in terms of mean liquid holdup, pressure drop, pulsation intensity, pulsation propagation velocity, and spatial maldistribution maps of liquid holdup and liquid pulsation propagation velocity. The morphological features of liquid holdup pulsations as a function of cycle frequency were characterized in terms of breakthrough, plateau, and decay times. Gas/liquid alternating cyclic strategy was shown to produce long-lived liquid pulsations under the applied operating conditions and thus could be viewed as a new process intensification means to achieve uniform phase holdup and velocity distributions. In ON−OFF liquid cyclic operation, pulsation velocity did not increase along the bed unlike the ON−OFF gas and gas/liquid alternating cyclic modes where increased pulsation velocities were able to give rise to pulse flow regime. The gas/liquid alternating cyclic operation resulted in the shortest breakthrough and decay times and the longest plateau time, thus approaching the ideal square-shaped inlet pulsations for symmetrical splits. ECT imaging was also used to scrutinize the dynamics of local deposition of fines in trickle beds fed with kaolin suspensions under the three cyclic operations. Data revealed that applying ON−OFF gas and gas/liquid alternating cyclic methods resulted in significant reduction of fines deposition. This suggests new practical solutions for possible industrial implementation of self-cleaning modulation strategies of trickle beds subject to unwanted filtration during suspension flows. Note de contenu : Bibiogr. ISSN : 0885-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie900605b

Hydrodynamics of gas–liquid cocurrent flows in micropacked beds—wall visualization study / Ali Faridkhou in Industrial & engineering chemistry research, Vol. 51 N° 50 (Décembre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16495–16504 Titre : Hydrodynamics of gas–liquid cocurrent flows in micropacked beds—wall visualization study Type de document : texte imprimé Auteurs : Ali Faridkhou, Auteur ; Faïçal Larachi, Auteur Année de publication : 2013 Article en page(s) : pp. 16495–16504 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydrodynamics  Gas  Liquid Résumé : An inverted microscopy technique was implemented to scrutinize the wall-region hydrodynamics of gas–liquid cocurrent flows in micropacked beds. Digital image analysis enabled characterization of two contiguous flow regimes, hysteresis, and transition thereof. Low- and high-interaction regimes featuring, respectively, slow and rapid displacements of gas–liquid boundary were identified. The onset of regime changeover was delineated by distinguishing the fluctuating behavior in time of characteristic lengths extracted from the areas occupied by gas and liquid in the field of view. A Charpentier and Favier flow regime map demarcating low and high interaction regimes in conventional macroscale trickle beds was elaborated for the sake of comparison of micropacked bed transitions for three different gas–liquid systems (air–water, argon–water, and argon–sucrose solution). The flow regime map suggests that micropacked bed transition occurs at considerably lower L/G values. Manifestation of hysteresis in micropacked beds was apprehended via pressure drop measurements and wetting fraction determination both in imbibition and drainage modes. In agreement with macroscale packed bed observations, the drainage branch revealed a larger pressure drop and wetting fraction compared with the imbibition branch for the same set of bed and fluid flow rates. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301709x [article] Hydrodynamics of gas–liquid cocurrent flows in micropacked beds—wall visualization study [texte imprimé] / Ali Faridkhou, Auteur ; Faïçal Larachi, Auteur . - 2013 . - pp. 16495–16504. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 50 (Décembre 2012) . - pp. 16495–16504 Mots-clés : Hydrodynamics  Gas  Liquid Résumé : An inverted microscopy technique was implemented to scrutinize the wall-region hydrodynamics of gas–liquid cocurrent flows in micropacked beds. Digital image analysis enabled characterization of two contiguous flow regimes, hysteresis, and transition thereof. Low- and high-interaction regimes featuring, respectively, slow and rapid displacements of gas–liquid boundary were identified. The onset of regime changeover was delineated by distinguishing the fluctuating behavior in time of characteristic lengths extracted from the areas occupied by gas and liquid in the field of view. A Charpentier and Favier flow regime map demarcating low and high interaction regimes in conventional macroscale trickle beds was elaborated for the sake of comparison of micropacked bed transitions for three different gas–liquid systems (air–water, argon–water, and argon–sucrose solution). The flow regime map suggests that micropacked bed transition occurs at considerably lower L/G values. Manifestation of hysteresis in micropacked beds was apprehended via pressure drop measurements and wetting fraction determination both in imbibition and drainage modes. In agreement with macroscale packed bed observations, the drainage branch revealed a larger pressure drop and wetting fraction compared with the imbibition branch for the same set of bed and fluid flow rates. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301709x

Modeling of heat uptake and release with embedded phase-change materials in monolithic microfluidized bed reactors / Akash Mittal in Industrial & engineering chemistry research, Vol. 49 N° 3 (Fevrier 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 3 (Fevrier 2010) . - pp. 1086–1097 Titre : Modeling of heat uptake and release with embedded phase-change materials in monolithic microfluidized bed reactors Type de document : texte imprimé Auteurs : Akash Mittal, Auteur ; Shantanu Roy, Auteur ; Faïçal Larachi, Auteur Année de publication : 2010 Article en page(s) : pp. 1086–1097 Note générale : Industrial Industrial Langues : Anglais (eng) Mots-clés : Heat--Uptake--Modeling--Release--Embedded--Phase-Change--Reactors--Microfluidized--Monolithic--Bed Résumé : An innovative process concept for biomass gasification is proposed, which involves a combination of gasification and combustion reactions in a monolithic structured reactor by using high-temperature phase-change materials to intensify the process heat management. In this paper we specifically look at the heat transport problem, dynamics of which drives the overall dynamics of the proposed process concept. Exploiting the large “separation of scales” between the axial and radial coordinates, we have addressed the modeling problem at the corresponding scales with a simplified, one-dimensional dynamic model in the reactor (axial) scale and a detailed dynamic finite element method (FEM) model at the channel (radial) scale. This contribution relates to the latter model, wherein we have investigated the effect of various controlling physical parameters as well and geometrical and configurational aspects. Finally, we identify ways in which such a process concept may be optimized. Note de contenu : Bibiogr. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9007425 [article] Modeling of heat uptake and release with embedded phase-change materials in monolithic microfluidized bed reactors [texte imprimé] / Akash Mittal, Auteur ; Shantanu Roy, Auteur ; Faïçal Larachi, Auteur . - 2010 . - pp. 1086–1097. Industrial Industrial Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 3 (Fevrier 2010) . - pp. 1086–1097 Mots-clés : Heat--Uptake--Modeling--Release--Embedded--Phase-Change--Reactors--Microfluidized--Monolithic--Bed Résumé : An innovative process concept for biomass gasification is proposed, which involves a combination of gasification and combustion reactions in a monolithic structured reactor by using high-temperature phase-change materials to intensify the process heat management. In this paper we specifically look at the heat transport problem, dynamics of which drives the overall dynamics of the proposed process concept. Exploiting the large “separation of scales” between the axial and radial coordinates, we have addressed the modeling problem at the corresponding scales with a simplified, one-dimensional dynamic model in the reactor (axial) scale and a detailed dynamic finite element method (FEM) model at the channel (radial) scale. This contribution relates to the latter model, wherein we have investigated the effect of various controlling physical parameters as well and geometrical and configurational aspects. Finally, we identify ways in which such a process concept may be optimized. Note de contenu : Bibiogr. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9007425

Monitoring filtration in trickle beds using electrical capacitance tomography / Mohsen Hamidipour in Industrial & engineering chemistry research, Vol. 48 N°3 (Février 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N°3 (Février 2009) . - p. 1140–1153 Titre : Monitoring filtration in trickle beds using electrical capacitance tomography Type de document : texte imprimé Auteurs : Mohsen Hamidipour, Auteur ; Faïçal Larachi, Auteur ; Zbigniew Ring, Auteur Année de publication : 2009 Article en page(s) : p. 1140–1153 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Trickle  Beds  --  Filtration  Oil  Hydrocarbon Résumé : Experiments were carried out to monitor the evolution of the deposition of fine particles in trickle-bed reactors during the flow of nonpolar hydrocarbon oil-like liquid suspensions using electrical capacitance tomography (ECT) imaging. The accuracy of the ECT rendition was validated in the pristine (i.e., deposit-free) bed state by comparing the liquid holdup measurements from ECT with the liquid holdup from residence time distribution (RTD) measurements. The pulse-flow characteristics (pulse velocity and frequency) estimated from the ECT signals were in agreement with existing literature data. For filtration experiments, the effects of the initial liquid suspension distribution, the gas and liquid superficial velocities, and single-phase flow (i.e., zero gas velocity) on the structure of the deposition in the bed were studied. ECT imaging successfully tracked the unsteady-state progression of bed plugging throughout the trickle bed. It was found that increasing the liquid or gas superficial velocity resulted in increased local deposition. The transition, due to deposition, from trickle to pulse flow was also determined from ECT. In the case of stagnant gas, a filter cake formed on top of the bed. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800810t [article] Monitoring filtration in trickle beds using electrical capacitance tomography [texte imprimé] / Mohsen Hamidipour, Auteur ; Faïçal Larachi, Auteur ; Zbigniew Ring, Auteur . - 2009 . - p. 1140–1153. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N°3 (Février 2009) . - p. 1140–1153 Mots-clés : Trickle  Beds  --  Filtration  Oil  Hydrocarbon Résumé : Experiments were carried out to monitor the evolution of the deposition of fine particles in trickle-bed reactors during the flow of nonpolar hydrocarbon oil-like liquid suspensions using electrical capacitance tomography (ECT) imaging. The accuracy of the ECT rendition was validated in the pristine (i.e., deposit-free) bed state by comparing the liquid holdup measurements from ECT with the liquid holdup from residence time distribution (RTD) measurements. The pulse-flow characteristics (pulse velocity and frequency) estimated from the ECT signals were in agreement with existing literature data. For filtration experiments, the effects of the initial liquid suspension distribution, the gas and liquid superficial velocities, and single-phase flow (i.e., zero gas velocity) on the structure of the deposition in the bed were studied. ECT imaging successfully tracked the unsteady-state progression of bed plugging throughout the trickle bed. It was found that increasing the liquid or gas superficial velocity resulted in increased local deposition. The transition, due to deposition, from trickle to pulse flow was also determined from ECT. In the case of stagnant gas, a filter cake formed on top of the bed. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie800810t

Phase holdups in three-phase semifluidized beds and the generalized bubble wake model / Markus Schubert in Industrial & engineering chemistry research, Vol. 48 N° 18 (Septembre 2009) 

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Prediction of solids accumulation in slurry bubble columns with polydispersed solid loadings / Ion Iliuta in Industrial & engineering chemistry research, Vol. 51 N° 40 (Octobre 2012) 

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Simulating the dynamics of gas−solid flows in a multichannel microcirculating fluidized bed / Yi-Ning Wang in Industrial & engineering chemistry research, Vol. 48 N° 17 (Septembre 2009) 

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