Documents disponibles écrits par cet auteur

Enhanced mass transfer of CO2 into water / R. Farajzadeh in Industrial & engineering chemistry research, Vol. 48 N° 13 (Juillet 2009) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 48 N° 13 (Juillet 2009) . - pp. 6423–6431 Titre : Enhanced mass transfer of CO2 into water : experiment and modeling Type de document : texte imprimé Auteurs : R. Farajzadeh, Auteur ; P. L. J. Zitha, Auteur ; J. Bruining, Auteur Année de publication : 2009 Article en page(s) : pp. 6423–6431 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : CO2  Sub-surface  water  Mass  transfer Résumé : Concern over global warming has increased interest in quantification of the dissolution of CO2 in (sub-)surface water. The mechanisms of the mass transfer of CO2 in aquifers and of transfer to surface water have many common features. The advantage of experiments using bulk water is that the underlying assumptions to the quantify mass-transfer rate can be validated. Dissolution of CO2 into water (or oil) increases the density of the liquid phase. This density change destabilizes the interface and enhances the transfer rate across the interface by natural convection. This paper describes a series of experiments performed in a cylindrical PVT-cell at a pressure range of pi = 10−50 bar, where a fixed volume of CO2 gas was brought into contact with a column of distilled water. The transfer rate is inferred by following the gas pressure history. The results show that the mass-transfer rate across the interface is much faster than that predicted by Fickian diffusion and increases with increasing initial gas pressure. The theoretical interpretation of the observed effects is based on diffusion and natural convection phenomena. The CO2 concentration at the interface is estimated from the gas pressure using Henry’s solubility law, in which the coefficient varies with both pressure and temperature. Good agreement between the experiments and the theoretical results has been obtained. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801521u [article] Enhanced mass transfer of CO2 into water : experiment and modeling [texte imprimé] / R. Farajzadeh, Auteur ; P. L. J. Zitha, Auteur ; J. Bruining, Auteur . - 2009 . - pp. 6423–6431. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 48 N° 13 (Juillet 2009) . - pp. 6423–6431 Mots-clés : CO2  Sub-surface  water  Mass  transfer Résumé : Concern over global warming has increased interest in quantification of the dissolution of CO2 in (sub-)surface water. The mechanisms of the mass transfer of CO2 in aquifers and of transfer to surface water have many common features. The advantage of experiments using bulk water is that the underlying assumptions to the quantify mass-transfer rate can be validated. Dissolution of CO2 into water (or oil) increases the density of the liquid phase. This density change destabilizes the interface and enhances the transfer rate across the interface by natural convection. This paper describes a series of experiments performed in a cylindrical PVT-cell at a pressure range of pi = 10−50 bar, where a fixed volume of CO2 gas was brought into contact with a column of distilled water. The transfer rate is inferred by following the gas pressure history. The results show that the mass-transfer rate across the interface is much faster than that predicted by Fickian diffusion and increases with increasing initial gas pressure. The theoretical interpretation of the observed effects is based on diffusion and natural convection phenomena. The CO2 concentration at the interface is estimated from the gas pressure using Henry’s solubility law, in which the coefficient varies with both pressure and temperature. Good agreement between the experiments and the theoretical results has been obtained. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie801521u

Investigation of immiscible and miscible foam for enhancing oil recovery / R. Farajzadeh in Industrial & engineering chemistry research, Vol. 49 N° 4 (Fevrier 2010) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1910–1919 Titre : Investigation of immiscible and miscible foam for enhancing oil recovery Type de document : texte imprimé Auteurs : R. Farajzadeh, Auteur ; Andrianov, A., Auteur ; P. L. J. Zitha, Auteur Année de publication : 2010 Article en page(s) : pp 1910–1919 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Immiscible  miscible  foam  Oil  recovery. Résumé : We report the study of flow of CO2 and N2 foam in natural sandstone cores containing oil with the aid of X-ray computed tomography. The study is relevant for enhanced oil recovery (EOR). The cores were partially saturated with oil and brine (half top) and brine only (half bottom) to mimic the water−oil transition occurring in oil reservoirs. The CO2 was used either under subcritical conditions (P = 1 bar) or under supercritical (immiscible (P = 90 bar) and miscible (P = 137 bar)) conditions, whereas N2 remained subcritical. Prior to gas injection the cores were flooded with several pore volumes of water. In a typical foam experiment water flooding was followed by the injection of 1−2 pore volumes of a surfactant solution with alpha olefin sulfonate (AOS) as the foaming agent. We visually show how foam propagates in a porous medium containing oil. At low-pressure experiments (P = 1 bar) in the case of N2, weak foam could be formed in the oil-saturated part. Diffused oil bank is formed ahead of the foam front, which results in additional oil recovery, compared to pure gas injection. CO2 hardly foams in the oil-bearing part of the core, most likely due to its higher solubility. Above the critical point (P = 90 bar), CO2 injection following the slug of surfactant reduces its mobility when there is no oil. Nevertheless, when the foam front meets the oil, the interface between gas and liquid disappears. The presence of the surfactant (when foaming supercritical CO2) did not affect the oil recovery and pressure profile, indicating the detrimental effect of oil on foam stability in the medium. However, at miscible conditions (P = 137 bar), injection of surfactant prior to CO2 injection significantly increases the oil recovery. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901109d [article] Investigation of immiscible and miscible foam for enhancing oil recovery [texte imprimé] / R. Farajzadeh, Auteur ; Andrianov, A., Auteur ; P. L. J. Zitha, Auteur . - 2010 . - pp 1910–1919. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1910–1919 Mots-clés : Immiscible  miscible  foam  Oil  recovery. Résumé : We report the study of flow of CO2 and N2 foam in natural sandstone cores containing oil with the aid of X-ray computed tomography. The study is relevant for enhanced oil recovery (EOR). The cores were partially saturated with oil and brine (half top) and brine only (half bottom) to mimic the water−oil transition occurring in oil reservoirs. The CO2 was used either under subcritical conditions (P = 1 bar) or under supercritical (immiscible (P = 90 bar) and miscible (P = 137 bar)) conditions, whereas N2 remained subcritical. Prior to gas injection the cores were flooded with several pore volumes of water. In a typical foam experiment water flooding was followed by the injection of 1−2 pore volumes of a surfactant solution with alpha olefin sulfonate (AOS) as the foaming agent. We visually show how foam propagates in a porous medium containing oil. At low-pressure experiments (P = 1 bar) in the case of N2, weak foam could be formed in the oil-saturated part. Diffused oil bank is formed ahead of the foam front, which results in additional oil recovery, compared to pure gas injection. CO2 hardly foams in the oil-bearing part of the core, most likely due to its higher solubility. Above the critical point (P = 90 bar), CO2 injection following the slug of surfactant reduces its mobility when there is no oil. Nevertheless, when the foam front meets the oil, the interface between gas and liquid disappears. The presence of the surfactant (when foaming supercritical CO2) did not affect the oil recovery and pressure profile, indicating the detrimental effect of oil on foam stability in the medium. However, at miscible conditions (P = 137 bar), injection of surfactant prior to CO2 injection significantly increases the oil recovery. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie901109d

Rheological transition during foam flow in porous media / M. Simjoo in Industrial & engineering chemistry research, Vol. 51 N° 30 (Août 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 30 (Août 2012) . - pp. 10225-10231 Titre : Rheological transition during foam flow in porous media Type de document : texte imprimé Auteurs : M. Simjoo, Auteur ; Q. P. Nguyen, Auteur ; P. L. J. Zitha, Auteur Année de publication : 2012 Article en page(s) : pp. 10225-10231 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Porous  medium  Foam Résumé : The flow of nitrogen foam in Bentheimer sandstone cores previously saturated with a surfactant solution has been investigated experimentally. The displacement process was visualized with the aid of a computed tomography (CT) scanner. CT data were analyzed to obtain water saturation profiles at different times. Pressure drops measured over core segments were recorded to determine foam mobility. It was found that foam undergoes a sharp transition from a weak to a strong state at a critical gas saturation of Sgc = 0.75 ± 0.02. This effect was interpreted successfully by the rise of foam yield stress as gas saturation exceeds the Sgc. It is suggested that confined jamming is the most likely mechanism responsible for the mobility transition. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26201439 [article] Rheological transition during foam flow in porous media [texte imprimé] / M. Simjoo, Auteur ; Q. P. Nguyen, Auteur ; P. L. J. Zitha, Auteur . - 2012 . - pp. 10225-10231. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 30 (Août 2012) . - pp. 10225-10231 Mots-clés : Porous  medium  Foam Résumé : The flow of nitrogen foam in Bentheimer sandstone cores previously saturated with a surfactant solution has been investigated experimentally. The displacement process was visualized with the aid of a computed tomography (CT) scanner. CT data were analyzed to obtain water saturation profiles at different times. Pressure drops measured over core segments were recorded to determine foam mobility. It was found that foam undergoes a sharp transition from a weak to a strong state at a critical gas saturation of Sgc = 0.75 ± 0.02. This effect was interpreted successfully by the rise of foam yield stress as gas saturation exceeds the Sgc. It is suggested that confined jamming is the most likely mechanism responsible for the mobility transition. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26201439