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Artificial neural network and neuro - fuzzy methodology for phase distribution modeling of a liquid – solid circulating fluidized bed riser / Shaikh A. Razzak in Industrial & engineering chemistry research, Vol. 51 N° 38 (Septembre 2012) 

Public ISBD [article]  in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12497–12508 Titre : Artificial neural network and neuro - fuzzy methodology for phase distribution modeling of a liquid – solid circulating fluidized bed riser Type de document : texte imprimé Auteurs : Shaikh A. Razzak, Auteur ; Syed M. Rahman, Auteur ; Mohammad M. Hossain, Auteur Année de publication : 2012 Article en page(s) : pp. 12497–12508 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Neural  network  Liquid  solid Résumé : Artificial Neural Network (ANN) and Adaptive Neuro-Fuzzy Inference System (ANFIS) modeling techniques are applied to study the radial and axial solids holdup distributions in a liquid–solid circulating fluidized bed (LSCFB) system. The modeling process is based on the experiments that were conducted using 500 μm size glass beads as solid phase. The radial nonuniformity of the solids holdup is observed under different superficial liquid velocities at superficial solids velocity of 0.95 cm/s and auxiliary liquid velocity of 1.4 cm/s at four axial locations (H = 1.0, 2.0, 3.0, and 3.8 m above the distributor). The effects of different operating parameters such as auxiliary and primary liquid velocities and superficial solids velocity on radial phase distribution in different axial positions of the riser are considered in the model development and analysis. The adequacy of the developed models is investigated by comparing the model predicted and experimental solids holdup data obtained from the pilot scale LSCFB reactor. Radial nonuniformity of the solids holdup is observed under different superficial liquid velocities at superficial solids velocity of 0.95 cm/s and auxiliary liquid velocities of 1.4 cm/s at four axial locations (H = 1, 2, 3, and 3.8 m above the distributor). The cross-sectional average solids holdup in axial directions is compared to the output of the two models. The model outputs show good agreements with the experimental data and reasonable trends of phase distributions. The correlation coefficient values of the predicted output and the experimental data are 0.95 and 0.96 for ANFIS and ANN models, respectively. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301746y [article] Artificial neural network and neuro - fuzzy methodology for phase distribution modeling of a liquid – solid circulating fluidized bed riser [texte imprimé] / Shaikh A. Razzak, Auteur ; Syed M. Rahman, Auteur ; Mohammad M. Hossain, Auteur . - 2012 . - pp. 12497–12508. Industrial chemistry Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 51 N° 38 (Septembre 2012) . - pp. 12497–12508 Mots-clés : Neural  network  Liquid  solid Résumé : Artificial Neural Network (ANN) and Adaptive Neuro-Fuzzy Inference System (ANFIS) modeling techniques are applied to study the radial and axial solids holdup distributions in a liquid–solid circulating fluidized bed (LSCFB) system. The modeling process is based on the experiments that were conducted using 500 μm size glass beads as solid phase. The radial nonuniformity of the solids holdup is observed under different superficial liquid velocities at superficial solids velocity of 0.95 cm/s and auxiliary liquid velocity of 1.4 cm/s at four axial locations (H = 1.0, 2.0, 3.0, and 3.8 m above the distributor). The effects of different operating parameters such as auxiliary and primary liquid velocities and superficial solids velocity on radial phase distribution in different axial positions of the riser are considered in the model development and analysis. The adequacy of the developed models is investigated by comparing the model predicted and experimental solids holdup data obtained from the pilot scale LSCFB reactor. Radial nonuniformity of the solids holdup is observed under different superficial liquid velocities at superficial solids velocity of 0.95 cm/s and auxiliary liquid velocities of 1.4 cm/s at four axial locations (H = 1, 2, 3, and 3.8 m above the distributor). The cross-sectional average solids holdup in axial directions is compared to the output of the two models. The model outputs show good agreements with the experimental data and reasonable trends of phase distributions. The correlation coefficient values of the predicted output and the experimental data are 0.95 and 0.96 for ANFIS and ANN models, respectively. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301746y

Reduction kinetics of la modified NiO / La - γAl2O3 oxygen carrier for chemical - looping combustion / Mohammad M. Hossain 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. 11009–11017 Titre : Reduction kinetics of la modified NiO / La - γAl2O3 oxygen carrier for chemical - looping combustion Type de document : texte imprimé Auteurs : Mohammad M. Hossain, Auteur ; Mohammad R. Quddus, Auteur ; Hugo I. Lasa, Auteur Année de publication : 2011 Article en page(s) : pp. 11009–11017 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Kinetics  Oxygen  Combustion Résumé : La modified Ni/La-γAl2O3 oxygen carrier reduction kinetics is investigated using temperature programmed reduction (TPR) and a parameter nonlinear regression analysis. TPR profile study and XRD analysis of the completely oxidized samples show that NiO is the prevalent phase of the oxygen carrier. Hydrogen pulse chemisorption demonstrates that the nickel crystallite sizes remain unchanged over repeated reduction/oxidation cycles. A nucleation and nuclei growth model and an unreacted shrinking core model are developed based on the oxygen carrier characterization. Model discrimination is conducted based on SSQ, goodness of fittings, and minimum cross-correlation coefficients. On the basis of these statistical indicators, it is established that the random nucleation model describes the reduction of the oxygen carrier adequately. The estimated value of the activation energy for the La modified Ni/La-γAl2O3 sample is found to be 73.4 ± 2.6 kJ/mol, with this being significantly lower than the activation energy for the unmodified Ni/γAl2O3 sample (104.5 ± 3 kJ/mol). This suggests that the unmodified oxygen carrier requires higher activation energy, with this reflecting an increased difficulty of nickel phase reduction due to a strong interaction between nickel and alumina. The nucleation model, as established using TPR, is successfully validated for the reduction cycle using methane as a fuel gas in a CREC minifluidized riser simulator reactor operating under the expected operating conditions for large industrial scale chemical-looping combustion (CLC) units. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100424w [article] Reduction kinetics of la modified NiO / La - γAl2O3 oxygen carrier for chemical - looping combustion [texte imprimé] / Mohammad M. Hossain, Auteur ; Mohammad R. Quddus, Auteur ; Hugo I. Lasa, Auteur . - 2011 . - pp. 11009–11017. Chimie industrielle Langues : Anglais (eng) in Industrial & engineering chemistry research > Vol. 49 N° 21 (Novembre 2010) . - pp. 11009–11017 Mots-clés : Kinetics  Oxygen  Combustion Résumé : La modified Ni/La-γAl2O3 oxygen carrier reduction kinetics is investigated using temperature programmed reduction (TPR) and a parameter nonlinear regression analysis. TPR profile study and XRD analysis of the completely oxidized samples show that NiO is the prevalent phase of the oxygen carrier. Hydrogen pulse chemisorption demonstrates that the nickel crystallite sizes remain unchanged over repeated reduction/oxidation cycles. A nucleation and nuclei growth model and an unreacted shrinking core model are developed based on the oxygen carrier characterization. Model discrimination is conducted based on SSQ, goodness of fittings, and minimum cross-correlation coefficients. On the basis of these statistical indicators, it is established that the random nucleation model describes the reduction of the oxygen carrier adequately. The estimated value of the activation energy for the La modified Ni/La-γAl2O3 sample is found to be 73.4 ± 2.6 kJ/mol, with this being significantly lower than the activation energy for the unmodified Ni/γAl2O3 sample (104.5 ± 3 kJ/mol). This suggests that the unmodified oxygen carrier requires higher activation energy, with this reflecting an increased difficulty of nickel phase reduction due to a strong interaction between nickel and alumina. The nucleation model, as established using TPR, is successfully validated for the reduction cycle using methane as a fuel gas in a CREC minifluidized riser simulator reactor operating under the expected operating conditions for large industrial scale chemical-looping combustion (CLC) units. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie100424w