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Aqueous HCl electrolysis utilizing an oxygen reducing cathode / F. Mohammadi in Chemical engineering journal, Vol. 155 N° 3 (Decembre 2009) 

Public ISBD [article]  in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 757-762 Titre : Aqueous HCl electrolysis utilizing an oxygen reducing cathode Type de document : texte imprimé Auteurs : F. Mohammadi, Auteur ; S. N. Ashrafizadeh, Auteur ; A. Sattari, Auteur Année de publication : 2010 Article en page(s) : pp. 757-762 Note générale : Génie Chimique Langues : Anglais (eng) Mots-clés : Aqueous  HCl  Electrolysis  Oxygen  reducing  cathode  Membrane  CCE  MEA Index. décimale : 660 Résumé : The effects of various process parameters on the cell voltage and chlorine current efficiency (CCE) in a Half-MEA (Nafion® 115 membrane-Loading: 0.4 mg Pt/cm2) oxygen reducing membrane electrolysis cell employing a dimensionally stable anode (DSA®) were studied. Process parameters under investigation included anolyte concentration, anolyte flow rate, anolyte temperature, oxygen flow rate and applied current density. The effect of the latter parameters on the cell voltage and CCE was determined quantitatively. Taguchi and ANOVA techniques were employed for experimental design and data analysis, respectively. It was observed that increasing either of anolyte flow rate, anolyte concentration, oxygen flow rate and anolyte temperature caused a decrease in cell voltage and an increase in CCE. At the same time, increasing current density linearly increased cell voltage. Current density and the anolyte flow rate had the highest contributions, of 49.7% and 30.62%, to the cell voltage, respectively. On the other hand, the oxygen flow rate and the anolyte flow rate had the highest contributions, of 57.19% and 23.66%, on the CCE, respectively. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X8CD4K-3&_user=6 [...] [article] Aqueous HCl electrolysis utilizing an oxygen reducing cathode [texte imprimé] / F. Mohammadi, Auteur ; S. N. Ashrafizadeh, Auteur ; A. Sattari, Auteur . - 2010 . - pp. 757-762. Génie Chimique Langues : Anglais (eng) in Chemical engineering journal > Vol. 155 N° 3 (Decembre 2009) . - pp. 757-762 Mots-clés : Aqueous  HCl  Electrolysis  Oxygen  reducing  cathode  Membrane  CCE  MEA Index. décimale : 660 Résumé : The effects of various process parameters on the cell voltage and chlorine current efficiency (CCE) in a Half-MEA (Nafion® 115 membrane-Loading: 0.4 mg Pt/cm2) oxygen reducing membrane electrolysis cell employing a dimensionally stable anode (DSA®) were studied. Process parameters under investigation included anolyte concentration, anolyte flow rate, anolyte temperature, oxygen flow rate and applied current density. The effect of the latter parameters on the cell voltage and CCE was determined quantitatively. Taguchi and ANOVA techniques were employed for experimental design and data analysis, respectively. It was observed that increasing either of anolyte flow rate, anolyte concentration, oxygen flow rate and anolyte temperature caused a decrease in cell voltage and an increase in CCE. At the same time, increasing current density linearly increased cell voltage. Current density and the anolyte flow rate had the highest contributions, of 49.7% and 30.62%, to the cell voltage, respectively. On the other hand, the oxygen flow rate and the anolyte flow rate had the highest contributions, of 57.19% and 23.66%, on the CCE, respectively. DEWEY : 660 ISSN : 1385-8947 En ligne : http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6TFJ-4X8CD4K-3&_user=6 [...]

Development of an empirical model to predict the effect of contaminants in liquid-liquid extraction / S. N. Ashrafizadeh in Industrial & engineering chemistry research, Vol. 47 N°19 (Octobre 2008) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 47 N°19 (Octobre 2008) . - p. 7242–7249 Titre : Development of an empirical model to predict the effect of contaminants in liquid-liquid extraction Type de document : texte imprimé Auteurs : S. N. Ashrafizadeh, Auteur ; J. Saien, Auteur ; B. Reza, Auteur Année de publication : 2008 Article en page(s) : p. 7242–7249 Note générale : Chemical engineering Langues : Anglais (eng) Mots-clés : Slater  Liquid-liquid  extraction  unitsWater-acetone-toluene  system Résumé : In the presence of surface-active reagents, the flux of mass transfer into/from the droplets drastically decreases within the liquid−liquid extraction units. Therefore, particular design equations are required to incorporate the presence of contaminants in the design of industrial-scale extraction columns. In the combinatorial model of Slater, the mass-transfer coefficients for the continuous and dispersed phases are corrected with the aid of a contamination factor. However, since the latter factor in the Slater model is originally obtained from the experimental data, the Slater model is unable to predict the behavior of an extraction system where the experimental data are not available. In this research, the model of Slater, i.e., single-drop single-solvent model, was employed to simulate the experimental data of a water−acetone−toluene system in the presence of three surface-active reagents, i.e., SDS, Triton X-100, and DTMAC. These components exhibit anionic, cationic, and nonionic surfactants, respectively. The experimental data provided by Saien et al. for both directions of the mass transfer, i.e., continuous to dispersed phases and vice versa, were employed. Based on the experimental data along with the theoretical principles, an empirical model for the contamination factor was developed. The provided model predicts the mass-transfer coefficients within ±4% of certainty only through the physical properties data of the phases, independent of the surfactant type. Two different mechanisms for the mass transfer within the liquid droplets, depending on the size of the droplets, have been recognized. Simulation of the extraction system by the aid of the present model, along with the combinatorial model of Slater and the terminal velocity model of Grace, predicts the experimental results satisfactorily. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie0715557 [article] Development of an empirical model to predict the effect of contaminants in liquid-liquid extraction [texte imprimé] / S. N. Ashrafizadeh, Auteur ; J. Saien, Auteur ; B. Reza, Auteur . - 2008 . - p. 7242–7249. Chemical engineering Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 47 N°19 (Octobre 2008) . - p. 7242–7249 Mots-clés : Slater  Liquid-liquid  extraction  unitsWater-acetone-toluene  system Résumé : In the presence of surface-active reagents, the flux of mass transfer into/from the droplets drastically decreases within the liquid−liquid extraction units. Therefore, particular design equations are required to incorporate the presence of contaminants in the design of industrial-scale extraction columns. In the combinatorial model of Slater, the mass-transfer coefficients for the continuous and dispersed phases are corrected with the aid of a contamination factor. However, since the latter factor in the Slater model is originally obtained from the experimental data, the Slater model is unable to predict the behavior of an extraction system where the experimental data are not available. In this research, the model of Slater, i.e., single-drop single-solvent model, was employed to simulate the experimental data of a water−acetone−toluene system in the presence of three surface-active reagents, i.e., SDS, Triton X-100, and DTMAC. These components exhibit anionic, cationic, and nonionic surfactants, respectively. The experimental data provided by Saien et al. for both directions of the mass transfer, i.e., continuous to dispersed phases and vice versa, were employed. Based on the experimental data along with the theoretical principles, an empirical model for the contamination factor was developed. The provided model predicts the mass-transfer coefficients within ±4% of certainty only through the physical properties data of the phases, independent of the surfactant type. Two different mechanisms for the mass transfer within the liquid droplets, depending on the size of the droplets, have been recognized. Simulation of the extraction system by the aid of the present model, along with the combinatorial model of Slater and the terminal velocity model of Grace, predicts the experimental results satisfactorily. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie0715557

Novel equation for the prediction of rheological parameters of drilling fluids in an annulus / M. Nasiri 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. 3374–3385 Titre : Novel equation for the prediction of rheological parameters of drilling fluids in an annulus Type de document : texte imprimé Auteurs : M. Nasiri, Auteur ; S. N. Ashrafizadeh, Auteur Année de publication : 2010 Article en page(s) : pp. 3374–3385 Note générale : Industrial Chemistry Langues : Anglais (eng) Mots-clés : Novel  Equation  Prediction  Rheological  Drilling  Fluids  Annulus Résumé : Several well-known correlations such as the Bingham-plastic, power-law, and Herschel−Bulkley models have been used so far to determine the rheological parameters of drilling fluids. For some particular fluids, however, even a three-parameter model such as Herschel−Bulkley does not exhibit appropriate behavior. On the other hand, determination of the rheological parameters by numerical methods such as nonlinear regression may provide meaningless values, i.e. negative yield stresses. This is particularly notable in determination of yield stress, which identifies the capacity of the drilling fluid to carry the cuttings. In this work, a new equation has been developed which is capable of determining the rheological parameters and, more particularly, the yield stress of drilling fluids. It is demonstrated that the developed correlation improves the prediction of the rheological parameters of the fluids by including a logarithmic term. The velocity profiles and pressure drop values obtained for several drilling fluids in an annulus geometry exhibit the suitability of this novel equation in comparison with the previously mentioned equations. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9009233 [article] Novel equation for the prediction of rheological parameters of drilling fluids in an annulus [texte imprimé] / M. Nasiri, Auteur ; S. N. Ashrafizadeh, Auteur . - 2010 . - pp. 3374–3385. Industrial Chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 7 (Avril 2010) . - pp. 3374–3385 Mots-clés : Novel  Equation  Prediction  Rheological  Drilling  Fluids  Annulus Résumé : Several well-known correlations such as the Bingham-plastic, power-law, and Herschel−Bulkley models have been used so far to determine the rheological parameters of drilling fluids. For some particular fluids, however, even a three-parameter model such as Herschel−Bulkley does not exhibit appropriate behavior. On the other hand, determination of the rheological parameters by numerical methods such as nonlinear regression may provide meaningless values, i.e. negative yield stresses. This is particularly notable in determination of yield stress, which identifies the capacity of the drilling fluid to carry the cuttings. In this work, a new equation has been developed which is capable of determining the rheological parameters and, more particularly, the yield stress of drilling fluids. It is demonstrated that the developed correlation improves the prediction of the rheological parameters of the fluids by including a logarithmic term. The velocity profiles and pressure drop values obtained for several drilling fluids in an annulus geometry exhibit the suitability of this novel equation in comparison with the previously mentioned equations. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie9009233