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Vol. 51 N° 37 - Septembre 2012 [texte imprimé] . - 2012 . - p. 11819-12154 : ill. ; 28 cm. Chemical engineering Langues : Anglais (eng)
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Ajouter le résultat dans votre panierHydrogen storage in perovskite - type oxides ABO3 for Ni / MH battery applications / Qiang Wang in Industrial & engineering chemistry research, Vol. 51 N° 37 (Septembre 2012)
Titre : Hydrogen storage in perovskite - type oxides ABO3 for Ni / MH battery applications : A density functional investigation Type de document : texte imprimé Auteurs : Qiang Wang, Auteur ; Zhiqian Chen, Auteur ; Yungui Chen, Auteur Année de publication : 2012 Article en page(s) : pp. 11821–11827 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydrogen Oxides Résumé : Perovskite oxides were typically considered as the electronic and ionic conductors for application in the electrolytes for solid oxides fuel cells (SOFCs). Recently, LaFeO3-based systems were mainly focused on the electrochemical property for the anode of Ni/MH batteries in our previous work, and the exciting results of their electrochemistry capacity and cycle life examination exhibited much scientific values for further investigation. In the present work, the effects of A (La)-site or B (Fe)-site metal ions doped and substituted on the fundamental properties of these materials were calculated by a first-principle approach. In conjunction with the experimental results, the microscopic mechanisms of the doped or substituted effect were discussed and elucidated. On the other hand, the hydrides of LaFe(Cr)O3 were established and computed to explore the nature of electrochemical behaviors of these perovskite oxides. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202284z
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11821–11827[article] Hydrogen storage in perovskite - type oxides ABO3 for Ni / MH battery applications : A density functional investigation [texte imprimé] / Qiang Wang, Auteur ; Zhiqian Chen, Auteur ; Yungui Chen, Auteur . - 2012 . - pp. 11821–11827.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11821–11827
Mots-clés : Hydrogen Oxides Résumé : Perovskite oxides were typically considered as the electronic and ionic conductors for application in the electrolytes for solid oxides fuel cells (SOFCs). Recently, LaFeO3-based systems were mainly focused on the electrochemical property for the anode of Ni/MH batteries in our previous work, and the exciting results of their electrochemistry capacity and cycle life examination exhibited much scientific values for further investigation. In the present work, the effects of A (La)-site or B (Fe)-site metal ions doped and substituted on the fundamental properties of these materials were calculated by a first-principle approach. In conjunction with the experimental results, the microscopic mechanisms of the doped or substituted effect were discussed and elucidated. On the other hand, the hydrides of LaFe(Cr)O3 were established and computed to explore the nature of electrochemical behaviors of these perovskite oxides. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202284z Exemplaires
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Titre : Review : Photochemical and thermochemical production of solar fuels from H2O and CO2 using metal oxide catalysts Type de document : texte imprimé Auteurs : Greg P. Smestad, Auteur ; Aldo Steinfeld, Auteur Année de publication : 2012 Article en page(s) : pp. 11828–11840 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Photochemical Thermochemical Production Résumé : Metal oxides are reviewed as catalysts to convert H2O and CO2 to fuels using solar energy. For photochemical conversion, TiO2 has been found to be the most stable and useful oxide material, but it is currently limited by its large bandgap and a mismatch between its conduction band and the redox couples for water splitting and CO2 reduction. A theoretical framework has been utilized to understand the basic thermodynamics and energetics in photochemical energy conversion systems. This is applied to model systems comprised of Ag2O and AgCl to examine why the former reacts thermochemically in air, while the latter reacts photochemically. For thermochemical conversion, zinc-, ceria-, and ferrite-based redox cycles are examined and examples of high-temperature solar reactors driven by concentrated solar radiation are presented. For CO2 splitting, theoretical solar-to-fuel energy conversion efficiencies can be up to 26.8% for photochemical systems, and can exceed 30% for thermochemical systems, provided that sensible heat is recovered between the redox steps. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3007962
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11828–11840[article] Review : Photochemical and thermochemical production of solar fuels from H2O and CO2 using metal oxide catalysts [texte imprimé] / Greg P. Smestad, Auteur ; Aldo Steinfeld, Auteur . - 2012 . - pp. 11828–11840.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11828–11840
Mots-clés : Photochemical Thermochemical Production Résumé : Metal oxides are reviewed as catalysts to convert H2O and CO2 to fuels using solar energy. For photochemical conversion, TiO2 has been found to be the most stable and useful oxide material, but it is currently limited by its large bandgap and a mismatch between its conduction band and the redox couples for water splitting and CO2 reduction. A theoretical framework has been utilized to understand the basic thermodynamics and energetics in photochemical energy conversion systems. This is applied to model systems comprised of Ag2O and AgCl to examine why the former reacts thermochemically in air, while the latter reacts photochemically. For thermochemical conversion, zinc-, ceria-, and ferrite-based redox cycles are examined and examples of high-temperature solar reactors driven by concentrated solar radiation are presented. For CO2 splitting, theoretical solar-to-fuel energy conversion efficiencies can be up to 26.8% for photochemical systems, and can exceed 30% for thermochemical systems, provided that sensible heat is recovered between the redox steps. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3007962 Exemplaires
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Titre : Enhanced charge separation in nanostructured TiO2 materials for photocatalytic and photovoltaic applications Type de document : texte imprimé Auteurs : He He, Auteur ; Chao Liu, Auteur ; Kevin D. Dubois, Auteur Année de publication : 2012 Article en page(s) : pp. 11841–11849 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Photocatalytic Photovoltaic Résumé : Titanium dioxide (TiO2) has been extensively investigated in solar energy applications, including heterogeneous photocatalysis and photovoltaics. For most TiO2 materials, charge recombination between photoexcited electrons and holes severely limits the efficiencies of solar energy conversion. Different strategies have been attempted to improve charge separation in TiO2 materials. This review focuses on three effective approaches to achieve enhanced charge separation by constructing mixed-phase TiO2, highly dispersed titanium oxides, and nanotubular TiO2 materials. Selected examples from the literature are discussed to demonstrate how the three approaches could be implemented in the context of photocatalytic water splitting, photocatalytic CO2 reduction, and dye-sensitized solar cells. The discussion provides useful insights regarding the design of new TiO2 nanostructures for use in solar energy conversion. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300510n
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11841–11849[article] Enhanced charge separation in nanostructured TiO2 materials for photocatalytic and photovoltaic applications [texte imprimé] / He He, Auteur ; Chao Liu, Auteur ; Kevin D. Dubois, Auteur . - 2012 . - pp. 11841–11849.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11841–11849
Mots-clés : Photocatalytic Photovoltaic Résumé : Titanium dioxide (TiO2) has been extensively investigated in solar energy applications, including heterogeneous photocatalysis and photovoltaics. For most TiO2 materials, charge recombination between photoexcited electrons and holes severely limits the efficiencies of solar energy conversion. Different strategies have been attempted to improve charge separation in TiO2 materials. This review focuses on three effective approaches to achieve enhanced charge separation by constructing mixed-phase TiO2, highly dispersed titanium oxides, and nanotubular TiO2 materials. Selected examples from the literature are discussed to demonstrate how the three approaches could be implemented in the context of photocatalytic water splitting, photocatalytic CO2 reduction, and dye-sensitized solar cells. The discussion provides useful insights regarding the design of new TiO2 nanostructures for use in solar energy conversion. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300510n Exemplaires
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Titre : Spectroscopic studies of light - driven water oxidation catalyzed by polyoxometalates Type de document : texte imprimé Auteurs : Zhuangqun Huang, Auteur ; Yurii V. Geletii, Auteur ; Djamaladdin G. Musaev, Auteur Année de publication : 2012 Article en page(s) : pp. 11850–11859 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Spectroscopic Oxidation Résumé : This review is focused on the spectroscopic studies of the charge transfer dynamics in polyoxometalate (POM)-catalyzed artificial photodriven water oxidation systems. We first describe the general challenges in solar fuel production, showing that water oxidation catalysts (WOCs) are of central importance. After the introduction of a new class of highly efficient WOCs based on all-inorganic polyoxometalates, we summarize the performance of these WOCs in homogeneous water oxidation systems. We show that the individual steps involved in the overall light-driven water oxidation reaction can be investigated by spectroscopic techniques (fluorescence quenching, transient absorption, and stopped flow). These studies provide important insight into the factors that limit the overall conversion efficiency in these systems and suggest possible approaches for improving these devices. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202950h
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11850–11859[article] Spectroscopic studies of light - driven water oxidation catalyzed by polyoxometalates [texte imprimé] / Zhuangqun Huang, Auteur ; Yurii V. Geletii, Auteur ; Djamaladdin G. Musaev, Auteur . - 2012 . - pp. 11850–11859.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11850–11859
Mots-clés : Spectroscopic Oxidation Résumé : This review is focused on the spectroscopic studies of the charge transfer dynamics in polyoxometalate (POM)-catalyzed artificial photodriven water oxidation systems. We first describe the general challenges in solar fuel production, showing that water oxidation catalysts (WOCs) are of central importance. After the introduction of a new class of highly efficient WOCs based on all-inorganic polyoxometalates, we summarize the performance of these WOCs in homogeneous water oxidation systems. We show that the individual steps involved in the overall light-driven water oxidation reaction can be investigated by spectroscopic techniques (fluorescence quenching, transient absorption, and stopped flow). These studies provide important insight into the factors that limit the overall conversion efficiency in these systems and suggest possible approaches for improving these devices. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202950h Exemplaires
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Titre : Experimental and Modeling Study of Continuous Catalytic Transesterification to Biodiesel in a Bench-Scale Fixed-Bed reactor Type de document : texte imprimé Auteurs : Yang Xiao, Auteur ; Lijing Gao, Auteur ; Guomin Xiao, Auteur Année de publication : 2012 Article en page(s) : pp. 11860–11865 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Catalytic Biodiesel Résumé : A 500 h endurance test of continuous catalytic transesterification to biodiesel was conducted in a bench-scale fixed-bed reactor. A designed cylinder shape of KF/Ca–Mg–Al hydrotalcite catalyst was stable through the test with high catalytic activity and mechanical strength, converting palm oil to biodiesel with a conversion of more than 95%. Conditions effects on transesterification under relative high pressure (1.0 MPa) were investigated and a one-dimensional heterogeneous model of a fixed-bed reactor was developed to describe the reaction-mass transfer behaviors of continuous catalytic transesterification in a bench-scale fixed-bed reactor. With the given reactor size, optimum conditions were proposed as a LHSV (liquid hourly space velocity) of 0.76–0.25 h–1, molar ratio of methanol-to-oil of 9.16–13.7, and temperature of 338–347 K. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202312z
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11860–11865[article] Experimental and Modeling Study of Continuous Catalytic Transesterification to Biodiesel in a Bench-Scale Fixed-Bed reactor [texte imprimé] / Yang Xiao, Auteur ; Lijing Gao, Auteur ; Guomin Xiao, Auteur . - 2012 . - pp. 11860–11865.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11860–11865
Mots-clés : Catalytic Biodiesel Résumé : A 500 h endurance test of continuous catalytic transesterification to biodiesel was conducted in a bench-scale fixed-bed reactor. A designed cylinder shape of KF/Ca–Mg–Al hydrotalcite catalyst was stable through the test with high catalytic activity and mechanical strength, converting palm oil to biodiesel with a conversion of more than 95%. Conditions effects on transesterification under relative high pressure (1.0 MPa) were investigated and a one-dimensional heterogeneous model of a fixed-bed reactor was developed to describe the reaction-mass transfer behaviors of continuous catalytic transesterification in a bench-scale fixed-bed reactor. With the given reactor size, optimum conditions were proposed as a LHSV (liquid hourly space velocity) of 0.76–0.25 h–1, molar ratio of methanol-to-oil of 9.16–13.7, and temperature of 338–347 K. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202312z Exemplaires
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Titre : Intensification of synthesis of biodiesel from nonedible oils using sonochemical reactors Type de document : texte imprimé Auteurs : Vitthal L. Gole, Auteur ; Parag R. Gogate, Auteur Année de publication : 2012 Article en page(s) : pp. 11866–11874 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Biodiesel Résumé : Biodiesel synthesis from nonedible oils, which offer excellent potential as sustainable feed stock, is highly energy-intensive and slow operation, because it requires considerable processing due to higher initial acid values and due to the fact that the reaction is mass-transfer-controlled. The present work reports the intensification of synthesis of biodiesel from the high-acid-value Nagchampa oil using sonochemical reactors. The synthesis process is a two-step method of esterification in the presence of homogeneous acid catalyst followed by transesterification using an alkaline (KOH) catalyst. The synthesis has also been attempted using conventional methods of reflux for analyzing the degree of intensification. With an objective of avoiding possible saponification reaction in the transesterification based on use of an alkaline catalyst, the acid value of oil was reduced from 18.4 mg KOH/g of oil to 1.4 mg KOH/g of oil, using the first-stage esterification method. The reduction in the acid value allows for an efficient second transesterification stage. The reaction temperature, molar ratio, and catalyst concentration were optimized for esterification and transesterification stages for the ultrasound and conventional techniques. It has been observed that the reaction temperature and reaction time required for esterification, as well as the transesterification stages, are substantially lower in the case of sonochemical reactors, compared to the conventional heating method. Also, the percentage excess of the reactants is significantly reduced, leading to energy savings in the subsequent separation processes for getting the purified product. Overall, the present work has clearly established the efficacy of sonochemical reactors for the intensification of biodiesel synthesis based on a sustainable raw material. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2029442
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11866–11874[article] Intensification of synthesis of biodiesel from nonedible oils using sonochemical reactors [texte imprimé] / Vitthal L. Gole, Auteur ; Parag R. Gogate, Auteur . - 2012 . - pp. 11866–11874.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11866–11874
Mots-clés : Biodiesel Résumé : Biodiesel synthesis from nonedible oils, which offer excellent potential as sustainable feed stock, is highly energy-intensive and slow operation, because it requires considerable processing due to higher initial acid values and due to the fact that the reaction is mass-transfer-controlled. The present work reports the intensification of synthesis of biodiesel from the high-acid-value Nagchampa oil using sonochemical reactors. The synthesis process is a two-step method of esterification in the presence of homogeneous acid catalyst followed by transesterification using an alkaline (KOH) catalyst. The synthesis has also been attempted using conventional methods of reflux for analyzing the degree of intensification. With an objective of avoiding possible saponification reaction in the transesterification based on use of an alkaline catalyst, the acid value of oil was reduced from 18.4 mg KOH/g of oil to 1.4 mg KOH/g of oil, using the first-stage esterification method. The reduction in the acid value allows for an efficient second transesterification stage. The reaction temperature, molar ratio, and catalyst concentration were optimized for esterification and transesterification stages for the ultrasound and conventional techniques. It has been observed that the reaction temperature and reaction time required for esterification, as well as the transesterification stages, are substantially lower in the case of sonochemical reactors, compared to the conventional heating method. Also, the percentage excess of the reactants is significantly reduced, leading to energy savings in the subsequent separation processes for getting the purified product. Overall, the present work has clearly established the efficacy of sonochemical reactors for the intensification of biodiesel synthesis based on a sustainable raw material. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2029442 Exemplaires
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Titre : Exoskeleton of a mollusk (Pila globosa) as a heterogeneous catalyst for synthesis of biodiesel using used frying oil Type de document : texte imprimé Auteurs : Shweta Agrawal, Auteur ; Bhaskar Singh, Auteur ; Yogesh Chandra Sharma, Auteur Année de publication : 2012 Article en page(s) : pp. 11875–11880 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Heterogeneous catalyst Biodiesel Résumé : A heterogeneous catalyst has been derived from a waste material (i.e., exoskeleton of mollusk) for transesterification of a waste feedstock (i.e., used frying oil (UFO)) for synthesis of biodiesel. The exoskeleton of mollusk shell was crushed, ground, and calcined at 900 °C to derive CaO as a heterogeneous catalyst. The catalyst was characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, X-ray fluorescence spectroscopy (XRF), and differential thermal analysis/thermogravimetric (DT/TG) analysis. The XRD peaks observed at 2θ = 31.80, 36.93, and 53.37° were characteristic of CaO and showed high crystallinity. The FTIR absorption bands of the calcined shell were observed at 1474, 870, and 502 cm–1, which are attributed to the vibration of CO32– molecules, and a sharp peak at 3640 cm–1 indicated the presence of OH– stretching due to Ca(OH)2. The XRF analysis demonstrated the Pila globosa shell to comprise 79.86% of calcium along with few minor elements (viz. Pd, I, Te, Sb, Sn, W, Al, Si, Sr, Cr, S). The (DT/TG) analysis showed the decomposition of calcium carbonate present in Pila globosa at 860 °C. The waste-driven substances (exoskeleton of mollusk as catalyst and UFO as feedstock) resulted in a high yield (92%) and conversion (97.8%) of biodiesel that was obtained at a 10:1 (methanol to oil) molar ratio, 4.0 wt % catalyst, at 60 ± 0.5 °C in 5 h reaction. The conversion of UFO to biodiesel was determined by 1H FT-NMR. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202404r
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11875–11880[article] Exoskeleton of a mollusk (Pila globosa) as a heterogeneous catalyst for synthesis of biodiesel using used frying oil [texte imprimé] / Shweta Agrawal, Auteur ; Bhaskar Singh, Auteur ; Yogesh Chandra Sharma, Auteur . - 2012 . - pp. 11875–11880.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11875–11880
Mots-clés : Heterogeneous catalyst Biodiesel Résumé : A heterogeneous catalyst has been derived from a waste material (i.e., exoskeleton of mollusk) for transesterification of a waste feedstock (i.e., used frying oil (UFO)) for synthesis of biodiesel. The exoskeleton of mollusk shell was crushed, ground, and calcined at 900 °C to derive CaO as a heterogeneous catalyst. The catalyst was characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, X-ray fluorescence spectroscopy (XRF), and differential thermal analysis/thermogravimetric (DT/TG) analysis. The XRD peaks observed at 2θ = 31.80, 36.93, and 53.37° were characteristic of CaO and showed high crystallinity. The FTIR absorption bands of the calcined shell were observed at 1474, 870, and 502 cm–1, which are attributed to the vibration of CO32– molecules, and a sharp peak at 3640 cm–1 indicated the presence of OH– stretching due to Ca(OH)2. The XRF analysis demonstrated the Pila globosa shell to comprise 79.86% of calcium along with few minor elements (viz. Pd, I, Te, Sb, Sn, W, Al, Si, Sr, Cr, S). The (DT/TG) analysis showed the decomposition of calcium carbonate present in Pila globosa at 860 °C. The waste-driven substances (exoskeleton of mollusk as catalyst and UFO as feedstock) resulted in a high yield (92%) and conversion (97.8%) of biodiesel that was obtained at a 10:1 (methanol to oil) molar ratio, 4.0 wt % catalyst, at 60 ± 0.5 °C in 5 h reaction. The conversion of UFO to biodiesel was determined by 1H FT-NMR. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202404r Exemplaires
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Titre : Effect of nanoparticles on flammability, UV resistance, biodegradability, and chemical resistance of wood polymer nanocomposite Type de document : texte imprimé Auteurs : Biplab K. Deka, Auteur ; Manabendra Mandal, Auteur ; Tarun K. Maji, Auteur Année de publication : 2012 Article en page(s) : pp. 11881–11891 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Nanoparticles Polymer Résumé : Wood polymer nanocomposite (WPNC) was developed by using high-density polyethylene (HDPE), low-density polyethylene (LDPE), polypropylene (PP), polyvinyl chloride (PVC), wood flour (WF), polyethylene-co-glycidyl methacrylate (PE-co-GMA), and different nanoparticles viz. nanoclay, SiO2, and ZnO. The distribution of nanoparticles was examined by X-ray diffraction (XRD) study. The change in surface morphology due to the addition of compatibilizer and nanoparticles was studied by scanning electron microscopy (SEM). The surface modification of nanoparticles by organic surfactant and their interaction with polymer and wood was studied by Fourier transform infrared spectroscopy (FTIR). The UV resistance property was improved after the incorporation of clay, SiO2, and ZnO. Bacterial degradation of WPC was found to increase linearly with the incorporation of clay and nanoparticles. The degraded samples showed lower mechanical properties. Flame retarding property, chemical resistance, and water vapor resistance were found maximum in WPC loaded with 3 phr each of clay, SiO2, and ZnO. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3003123
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11881–11891[article] Effect of nanoparticles on flammability, UV resistance, biodegradability, and chemical resistance of wood polymer nanocomposite [texte imprimé] / Biplab K. Deka, Auteur ; Manabendra Mandal, Auteur ; Tarun K. Maji, Auteur . - 2012 . - pp. 11881–11891.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11881–11891
Mots-clés : Nanoparticles Polymer Résumé : Wood polymer nanocomposite (WPNC) was developed by using high-density polyethylene (HDPE), low-density polyethylene (LDPE), polypropylene (PP), polyvinyl chloride (PVC), wood flour (WF), polyethylene-co-glycidyl methacrylate (PE-co-GMA), and different nanoparticles viz. nanoclay, SiO2, and ZnO. The distribution of nanoparticles was examined by X-ray diffraction (XRD) study. The change in surface morphology due to the addition of compatibilizer and nanoparticles was studied by scanning electron microscopy (SEM). The surface modification of nanoparticles by organic surfactant and their interaction with polymer and wood was studied by Fourier transform infrared spectroscopy (FTIR). The UV resistance property was improved after the incorporation of clay, SiO2, and ZnO. Bacterial degradation of WPC was found to increase linearly with the incorporation of clay and nanoparticles. The degraded samples showed lower mechanical properties. Flame retarding property, chemical resistance, and water vapor resistance were found maximum in WPC loaded with 3 phr each of clay, SiO2, and ZnO. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3003123 Exemplaires
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Titre : Investigation of the structure and catalytic performance of highly dispersed Ni - based catalysts for the growth of carbon nanostructures Type de document : texte imprimé Auteurs : Muzi Li, Auteur ; Guoli Fan, Auteur ; Hua Qin, Auteur Année de publication : 2012 Article en page(s) : pp. 11892–11900 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Catalysts Nanostructures Résumé : The in situ growth of Ni-containing layered double hydroxide (LDH) microcrystallites on microspherical γ-alumina support was carried out through the surface activation of support followed by a homogeneous coprecipitation process, and carbon nanomaterials were synthesized directly over as-grown supported LDH samples via catalytic chemical vapor deposition of acetylene. As compared to that prepared by the conventional impregnation, supported LDH samples calcined at 700 °C possessed higher metal dispersion, which was attributed to well-developed two-dimensional structure of LDH platelets uniformly grown on the support surface originating from the strong interaction between brucite-like lattices and support. Furthermore, the supported catalyst from NiAl-LDH could catalyze the growth of regular carbon nanofibers, while another one from NiMgAl-LDH exhibited excellent catalytic performance for the growth of uniform carbon nanotubes due to higher metal dispersion achieved by the separating effect of amorphous metal oxide (MgO and Al2O3) phases around Ni nanoparticles. As-synthesized supported Ni-based catalysts are promising for practical applications in the production of carbon nanostructures with uniform geometric shape. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3008659
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11892–11900[article] Investigation of the structure and catalytic performance of highly dispersed Ni - based catalysts for the growth of carbon nanostructures [texte imprimé] / Muzi Li, Auteur ; Guoli Fan, Auteur ; Hua Qin, Auteur . - 2012 . - pp. 11892–11900.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11892–11900
Mots-clés : Catalysts Nanostructures Résumé : The in situ growth of Ni-containing layered double hydroxide (LDH) microcrystallites on microspherical γ-alumina support was carried out through the surface activation of support followed by a homogeneous coprecipitation process, and carbon nanomaterials were synthesized directly over as-grown supported LDH samples via catalytic chemical vapor deposition of acetylene. As compared to that prepared by the conventional impregnation, supported LDH samples calcined at 700 °C possessed higher metal dispersion, which was attributed to well-developed two-dimensional structure of LDH platelets uniformly grown on the support surface originating from the strong interaction between brucite-like lattices and support. Furthermore, the supported catalyst from NiAl-LDH could catalyze the growth of regular carbon nanofibers, while another one from NiMgAl-LDH exhibited excellent catalytic performance for the growth of uniform carbon nanotubes due to higher metal dispersion achieved by the separating effect of amorphous metal oxide (MgO and Al2O3) phases around Ni nanoparticles. As-synthesized supported Ni-based catalysts are promising for practical applications in the production of carbon nanostructures with uniform geometric shape. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3008659 Exemplaires
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Titre : Selective recovery of precious metals from acidic leach liquor of circuit boards of spent mobile phones using chemically modified persimmon tannin gel Type de document : texte imprimé Auteurs : Manju Gurung, Auteur ; Birendra Babu Adhikari, Auteur ; Hidetaka Kawakita, Auteur Année de publication : 2012 Article en page(s) : pp. 11901–11913 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Precious metals Acidic leach Résumé : A tannin-based novel adsorbent, named “BTU-PT gel”, was prepared by immobilizing bisthiourea (BTU) ligand on persimmon tannin (PT) extract. The adsorption behaviors of precious metal ions along with other coexisting base metal ions onto BTU-PT gel were studied by batch and continuous column methods. The gel exhibited remarkable selectivity for precious metal ions such as Au(III), Pd(II), and Pt(IV) over base metal ions such as Cu(II), Fe(III), Ni(II), and Zn(II) in 1–5 mol dm–3 hydrochloric acid. The adsorption of precious metal ions on the present gel was found to obey the typical monolayer type of Langmuir model, and the maximum adsorption capacity of the adsorbent was evaluated as 5.18 mol kg–1 for Au(III), 1.80 mol kg–1 for Pd(II), and 0.67 mol kg–1 for Pt(IV). Combination of ion exchange, electrostatic interaction, and coordination through the thiocarbonyl group is the mechanism of adsorption of precious metals on BTU-PT gel. In the case of Au(III) adsorption, the adsorbed species was simultaneously reduced to elemental gold by abundant polyphenolic groups of the tannin matrix. Elution by using acidothiourea solution in continuous column experiment recovered the adsorbed precious metals almost quantitatively. The results of a potential reusability test of the gel for consecutive adsorption and elution cycles by continuous column experiment indicated that the gel was stable and regenerated with undiminished metal uptake capacity up to five cycles. The real time applicability of the adsorbent for the recovery of precious metals from real industrial liquor was evaluated from actual acidic leach liquor of printed circuit boards of spent mobile phones. The gel selectively adsorbed precious metal species but exhibited negligible affinity toward base metals present in the leach liquor. The BTU-PT gel is a potential adsorbent for selective recovery of precious metals from acidic leachate of spent mobile phones containing elevated concentrations of base metals. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3009023
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11901–11913[article] Selective recovery of precious metals from acidic leach liquor of circuit boards of spent mobile phones using chemically modified persimmon tannin gel [texte imprimé] / Manju Gurung, Auteur ; Birendra Babu Adhikari, Auteur ; Hidetaka Kawakita, Auteur . - 2012 . - pp. 11901–11913.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11901–11913
Mots-clés : Precious metals Acidic leach Résumé : A tannin-based novel adsorbent, named “BTU-PT gel”, was prepared by immobilizing bisthiourea (BTU) ligand on persimmon tannin (PT) extract. The adsorption behaviors of precious metal ions along with other coexisting base metal ions onto BTU-PT gel were studied by batch and continuous column methods. The gel exhibited remarkable selectivity for precious metal ions such as Au(III), Pd(II), and Pt(IV) over base metal ions such as Cu(II), Fe(III), Ni(II), and Zn(II) in 1–5 mol dm–3 hydrochloric acid. The adsorption of precious metal ions on the present gel was found to obey the typical monolayer type of Langmuir model, and the maximum adsorption capacity of the adsorbent was evaluated as 5.18 mol kg–1 for Au(III), 1.80 mol kg–1 for Pd(II), and 0.67 mol kg–1 for Pt(IV). Combination of ion exchange, electrostatic interaction, and coordination through the thiocarbonyl group is the mechanism of adsorption of precious metals on BTU-PT gel. In the case of Au(III) adsorption, the adsorbed species was simultaneously reduced to elemental gold by abundant polyphenolic groups of the tannin matrix. Elution by using acidothiourea solution in continuous column experiment recovered the adsorbed precious metals almost quantitatively. The results of a potential reusability test of the gel for consecutive adsorption and elution cycles by continuous column experiment indicated that the gel was stable and regenerated with undiminished metal uptake capacity up to five cycles. The real time applicability of the adsorbent for the recovery of precious metals from real industrial liquor was evaluated from actual acidic leach liquor of printed circuit boards of spent mobile phones. The gel selectively adsorbed precious metal species but exhibited negligible affinity toward base metals present in the leach liquor. The BTU-PT gel is a potential adsorbent for selective recovery of precious metals from acidic leachate of spent mobile phones containing elevated concentrations of base metals. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3009023 Exemplaires
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Titre : Production and application properties of dispersive viscosity index improvers Type de document : texte imprimé Auteurs : Ivana Soljic Jerbic, Auteur ; Jelena Parlov Vukovic, Auteur ; Ante Jukic, Auteur Année de publication : 2012 Article en page(s) : pp. 11914–11923 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Dispersive viscosity Résumé : Polymeric dispersive viscosity index improvers of lubricating mineral oils based on styrene, dodecyl-methacrylate, octadecyl methacrylate, and N,N-dimethylaminoethyl methacrylate (d-PSAMA) were produced by performing copolymerizations isothermally up to the high conversion in mineral base oil solution, using monofunctional or bifunctional peroxide initiator. The obtained kinetics results reveal the benefits of the usage of a bifunctional peroxide initiator over a monofunctional, because complete conversion of monomers was accomplished in the shorter reaction time, performing the process in a full batchwise mode. When the bifunctional initiator was applied, the required polymerization temperature was slightly higher (105 °C), and copolymers of higher average molecular weight values (Mw = 60–120 kg mol–1) were obtained, while in case of the monofunctional peroxide initiator, the reaction temperature was 100 °C, and average molecular weight values of copolymers were Mw = 30–100 kg/mol. Investigated application properties demonstrated that d-PSAMA additives were fully comparable with conventional pure methacrylate additives, and also it provided other advantages such as higher viscosity index and kinematic viscosity, lower values of pour point temperatures, as well as better dispersant and detergent properties. Thus, by increasing the N,N-dimethylaminoethyl methacrylate share in copolymers from 2 to 10 mol %, their weight average molecular weight decreased from 120 to 60 kg mol–1, while kinematic viscosity values at 100 °C remain high and amounted to 14.5 ± 0.5 mm2 s–1. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301010n
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11914–11923[article] Production and application properties of dispersive viscosity index improvers [texte imprimé] / Ivana Soljic Jerbic, Auteur ; Jelena Parlov Vukovic, Auteur ; Ante Jukic, Auteur . - 2012 . - pp. 11914–11923.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11914–11923
Mots-clés : Dispersive viscosity Résumé : Polymeric dispersive viscosity index improvers of lubricating mineral oils based on styrene, dodecyl-methacrylate, octadecyl methacrylate, and N,N-dimethylaminoethyl methacrylate (d-PSAMA) were produced by performing copolymerizations isothermally up to the high conversion in mineral base oil solution, using monofunctional or bifunctional peroxide initiator. The obtained kinetics results reveal the benefits of the usage of a bifunctional peroxide initiator over a monofunctional, because complete conversion of monomers was accomplished in the shorter reaction time, performing the process in a full batchwise mode. When the bifunctional initiator was applied, the required polymerization temperature was slightly higher (105 °C), and copolymers of higher average molecular weight values (Mw = 60–120 kg mol–1) were obtained, while in case of the monofunctional peroxide initiator, the reaction temperature was 100 °C, and average molecular weight values of copolymers were Mw = 30–100 kg/mol. Investigated application properties demonstrated that d-PSAMA additives were fully comparable with conventional pure methacrylate additives, and also it provided other advantages such as higher viscosity index and kinematic viscosity, lower values of pour point temperatures, as well as better dispersant and detergent properties. Thus, by increasing the N,N-dimethylaminoethyl methacrylate share in copolymers from 2 to 10 mol %, their weight average molecular weight decreased from 120 to 60 kg mol–1, while kinematic viscosity values at 100 °C remain high and amounted to 14.5 ± 0.5 mm2 s–1. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301010n Exemplaires
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Titre : Predicting pKa of amines for CO2 capture : Computer versus pencil - and - paper Type de document : texte imprimé Auteurs : Kazi Z. Sumon, Auteur ; Amr Henni, Auteur ; Allan L. L. East, Auteur Année de publication : 2012 Article en page(s) : pp. 11924–11930 Note générale : Industrial chmistry Langues : Anglais (eng) Mots-clés : Amines CO2 Capture Résumé : For pKa prediction of aliphatic amines (amines relevant to industrial CO2 capture), the performance of quantum-chemistry continuum-solvation methods is contrasted with the 1981 pencil-and-paper group-additivity method of Perrin, Dempsey, and Serjeant (PDS). We have optimized a quantum-chemistry continuum-plus-correction strategy, as well as updated the parameter values in the PDS method. The PDS method outperformed the continuum-based method: root-mean-square errors for a sample of 32 amines are 0.28 for the continuum-based method, 0.33 for the original PDS method, and 0.18 for the updated PDS method. Considering also that there is ambiguity in choice of cavity radii and molecular conformer for continuum-based methods, we recommend the pencil-and-paper PDS method over such methods. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301033p
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11924–11930[article] Predicting pKa of amines for CO2 capture : Computer versus pencil - and - paper [texte imprimé] / Kazi Z. Sumon, Auteur ; Amr Henni, Auteur ; Allan L. L. East, Auteur . - 2012 . - pp. 11924–11930.
Industrial chmistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11924–11930
Mots-clés : Amines CO2 Capture Résumé : For pKa prediction of aliphatic amines (amines relevant to industrial CO2 capture), the performance of quantum-chemistry continuum-solvation methods is contrasted with the 1981 pencil-and-paper group-additivity method of Perrin, Dempsey, and Serjeant (PDS). We have optimized a quantum-chemistry continuum-plus-correction strategy, as well as updated the parameter values in the PDS method. The PDS method outperformed the continuum-based method: root-mean-square errors for a sample of 32 amines are 0.28 for the continuum-based method, 0.33 for the original PDS method, and 0.18 for the updated PDS method. Considering also that there is ambiguity in choice of cavity radii and molecular conformer for continuum-based methods, we recommend the pencil-and-paper PDS method over such methods. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301033p Exemplaires
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Titre : High efficiency multijunction photovoltaic development Type de document : texte imprimé Auteurs : David Wilt, Auteur ; Mark Stan, Auteur Année de publication : 2012 Article en page(s) : pp. 11931–11940 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Multijunction Photovoltaic Résumé : Photovoltaic energy conversion has demonstrated remarkable improvements in performance over the past 60 years. The rate of solar cell efficiency change has actually increased over the past 20 years as researchers have moved beyond elemental semiconductors to increasingly more sophisticated materials and devices. In addition, significant improvements in materials quality and deposition technology have further fueled this dramatic improvement in device performance. Diversifying from silicon to III–V compound semiconductor materials has enabled the development of multijunction solar cells with 3, 4, and even 6 subcells to achieve ever higher conversion efficiency. For 1-sun space application(s), these III–V multijunction cells are demonstrating 35% efficiency, while under terrestrial concentrated sunlight conditions efficiencies are >42%. This Article will discuss the development of high efficiency III–V multijunction solar cells, focusing on recently developed metamorphic device structures and novel lattice matched approaches. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3012616
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11931–11940[article] High efficiency multijunction photovoltaic development [texte imprimé] / David Wilt, Auteur ; Mark Stan, Auteur . - 2012 . - pp. 11931–11940.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11931–11940
Mots-clés : Multijunction Photovoltaic Résumé : Photovoltaic energy conversion has demonstrated remarkable improvements in performance over the past 60 years. The rate of solar cell efficiency change has actually increased over the past 20 years as researchers have moved beyond elemental semiconductors to increasingly more sophisticated materials and devices. In addition, significant improvements in materials quality and deposition technology have further fueled this dramatic improvement in device performance. Diversifying from silicon to III–V compound semiconductor materials has enabled the development of multijunction solar cells with 3, 4, and even 6 subcells to achieve ever higher conversion efficiency. For 1-sun space application(s), these III–V multijunction cells are demonstrating 35% efficiency, while under terrestrial concentrated sunlight conditions efficiencies are >42%. This Article will discuss the development of high efficiency III–V multijunction solar cells, focusing on recently developed metamorphic device structures and novel lattice matched approaches. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3012616 Exemplaires
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Titre : Antiwear additive derived from soybean oil and boron utilized in a gear oil formulation Type de document : texte imprimé Auteurs : Brajendra K. Sharma, Auteur ; Kenneth M. Doll, Auteur ; Glenn L. Heise, Auteur Année de publication : 2012 Article en page(s) : pp. 11941–11945 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Lubricant additives Résumé : The synthesis of lubricant additives based on boron and epoxidized soybean oil are presented. These additives are made from a simple patent pending method involving a ring-opening reaction of the epoxidized oil. A couple of these borates were tested in soybean oil, polyalpha olefin basestock, group III basestock, and hexadecane. An aromatic additive was able to increase the oxidation onset of the basestocks by 14, 52, 48, and 49 °C, respectively, when used at 2% wt. The other additive was shown to reduce the wear scar diameter in a friction test when used in soybean oil basestock, from 0.61 mm down to 0.41 mm. These additives were also tested in a gear oil blend, and shown to reduce both wear and oxidation. They were also compatible with a popular additive, additive zinc dialkyl dithiophosphate. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301519r
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11941–11945[article] Antiwear additive derived from soybean oil and boron utilized in a gear oil formulation [texte imprimé] / Brajendra K. Sharma, Auteur ; Kenneth M. Doll, Auteur ; Glenn L. Heise, Auteur . - 2012 . - pp. 11941–11945.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11941–11945
Mots-clés : Lubricant additives Résumé : The synthesis of lubricant additives based on boron and epoxidized soybean oil are presented. These additives are made from a simple patent pending method involving a ring-opening reaction of the epoxidized oil. A couple of these borates were tested in soybean oil, polyalpha olefin basestock, group III basestock, and hexadecane. An aromatic additive was able to increase the oxidation onset of the basestocks by 14, 52, 48, and 49 °C, respectively, when used at 2% wt. The other additive was shown to reduce the wear scar diameter in a friction test when used in soybean oil basestock, from 0.61 mm down to 0.41 mm. These additives were also tested in a gear oil blend, and shown to reduce both wear and oxidation. They were also compatible with a popular additive, additive zinc dialkyl dithiophosphate. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301519r Exemplaires
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Titre : Semi - IPN chitosan / PEG microspheres and films for biomedical applications : Characterization and sustained release optimization Type de document : texte imprimé Auteurs : Ismail Dogan Gunbas, Auteur ; Umran Aydemir Sezer, Auteur ; Sultan Gulce iz, Auteur Année de publication : 2012 Article en page(s) : pp. 11946–11954 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Microspheres Optimization Résumé : Micro drug carriers are one of the efficient methods for local or systemic cancer treatment. In this study, the aim was to prepare a novel semi-interpenetrated (semi-IPN) micro system by using biocompatible chitosan (CH) and polyethylene glycol (PEG). Various combinations of the systems were prepared and loaded with a model chemotherapeutic drug, methotrexate (MTX), and the effects of composition on the properties and the release behavior of microspheres were examined. Also, the mechanical and thermal properties were examined on film forms of similar compositions. Increase in cross-linking caused a decrease in particle size of CH from 144 to 91 μm, while the addition of PEG caused an increase up to 163 μm. Elastic modulus values of the films first increased and then decreased parallel to PEG content. In vitro studies showed faster MTX release from semi-IPN CH-PEG microspheres as compared to pure CH ones. Promising results were obtained in the development of biodegradable drug vehicles. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3015523
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11946–11954[article] Semi - IPN chitosan / PEG microspheres and films for biomedical applications : Characterization and sustained release optimization [texte imprimé] / Ismail Dogan Gunbas, Auteur ; Umran Aydemir Sezer, Auteur ; Sultan Gulce iz, Auteur . - 2012 . - pp. 11946–11954.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11946–11954
Mots-clés : Microspheres Optimization Résumé : Micro drug carriers are one of the efficient methods for local or systemic cancer treatment. In this study, the aim was to prepare a novel semi-interpenetrated (semi-IPN) micro system by using biocompatible chitosan (CH) and polyethylene glycol (PEG). Various combinations of the systems were prepared and loaded with a model chemotherapeutic drug, methotrexate (MTX), and the effects of composition on the properties and the release behavior of microspheres were examined. Also, the mechanical and thermal properties were examined on film forms of similar compositions. Increase in cross-linking caused a decrease in particle size of CH from 144 to 91 μm, while the addition of PEG caused an increase up to 163 μm. Elastic modulus values of the films first increased and then decreased parallel to PEG content. In vitro studies showed faster MTX release from semi-IPN CH-PEG microspheres as compared to pure CH ones. Promising results were obtained in the development of biodegradable drug vehicles. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3015523 Exemplaires
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Titre : Mechanistic modeling of cobalt based catalyst sintering in a fixed bed reactor under different conditions of fischer – tropsch synthesis Type de document : texte imprimé Auteurs : Majid Sadeqzadeh, Auteur ; Jingping Hong, Auteur ; Pascal Fongarland, Auteur Année de publication : 2012 Article en page(s) : pp. 11955–11964 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Catalyst Résumé : A three-step sintering mechanism is proposed for Co-based catalysts under Fischer–Tropsch reaction conditions. This mechanism includes an intermediate formation of oxide layer on cobalt metal nanoparticles in the presence of water. The partially reversibly oxidized surface accelerates sintering by both reducing the surface energy and enhancing the diffusion rates of cobalt particles. The proposed mechanism is then employed for a fixed-bed unsteady state reactor. The effect of particle growth on the catalytic activity was analyzed within a diverse range of operating conditions (syngas ratio = 1.5–4, water co-feed ratio = 0–6, inert co-feed ratio = 0–6). It is found that, at the same gas space velocity, sintering proceeds faster at higher H2/CO ratios. At the same initial conversion, a low H2/CO syngas ratio increases sintering severity, i.e., catalyst deactivation due to the crystallite growth, as it brings about higher relative water partial pressure. Dilution of syngas with different amounts of inert gas does not affect the cobalt sintering rate. Cobalt sintering proceeds more rapidly if water is co-fed during the reaction. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3006929
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11955–11964[article] Mechanistic modeling of cobalt based catalyst sintering in a fixed bed reactor under different conditions of fischer – tropsch synthesis [texte imprimé] / Majid Sadeqzadeh, Auteur ; Jingping Hong, Auteur ; Pascal Fongarland, Auteur . - 2012 . - pp. 11955–11964.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11955–11964
Mots-clés : Catalyst Résumé : A three-step sintering mechanism is proposed for Co-based catalysts under Fischer–Tropsch reaction conditions. This mechanism includes an intermediate formation of oxide layer on cobalt metal nanoparticles in the presence of water. The partially reversibly oxidized surface accelerates sintering by both reducing the surface energy and enhancing the diffusion rates of cobalt particles. The proposed mechanism is then employed for a fixed-bed unsteady state reactor. The effect of particle growth on the catalytic activity was analyzed within a diverse range of operating conditions (syngas ratio = 1.5–4, water co-feed ratio = 0–6, inert co-feed ratio = 0–6). It is found that, at the same gas space velocity, sintering proceeds faster at higher H2/CO ratios. At the same initial conversion, a low H2/CO syngas ratio increases sintering severity, i.e., catalyst deactivation due to the crystallite growth, as it brings about higher relative water partial pressure. Dilution of syngas with different amounts of inert gas does not affect the cobalt sintering rate. Cobalt sintering proceeds more rapidly if water is co-fed during the reaction. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3006929 Exemplaires
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Titre : Esterification of acetic acid with n - hexanol in batch and continuous chromatographic reactors using a gelular ion - exchange resin as a catalyst Type de document : texte imprimé Auteurs : Dipesh Patel, Auteur ; Basudeb Saha, Auteur Année de publication : 2012 Article en page(s) : pp. 11965–11974 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Ion exchange Catalyst Résumé : Heterogeneously catalyzed esterification reactions of acetic acid and n-hexanol were studied in batch and continuous chromatographic reactors in the presence of a gelular ion-exchange resin catalyst (Purolite CT-124) to synthesize a value added ester, namely n-hexyl acetate. A laboratory scale batch chromatographic reactor column (BCRC) was designed and constructed. BCRC experiments were carried out using different parameters such as feed flow rate, feed mole ratio (FMR) of n-hexanol to acetic acid, desorbent (n-hexanol) flow rate, and reaction step time to maximize the formation of n-hexyl acetate as well as to achieve complete conversion of acetic acid. Samples were collected from the chromatographic reactor column (CRC) outlet at regular intervals and were analyzed by gas chromatography (GC). The continuous chromatographic reactor column (CCRC) was designed, constructed, and commissioned on the basis of the results obtained from the BCRC experiments. The experiments carried out in a CCRC correlate very well with the results obtained from the optimized reaction condition in a BCRC for maximum formation of n-hexyl acetate and complete conversion of acetic acid. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3007424
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11965–11974[article] Esterification of acetic acid with n - hexanol in batch and continuous chromatographic reactors using a gelular ion - exchange resin as a catalyst [texte imprimé] / Dipesh Patel, Auteur ; Basudeb Saha, Auteur . - 2012 . - pp. 11965–11974.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11965–11974
Mots-clés : Ion exchange Catalyst Résumé : Heterogeneously catalyzed esterification reactions of acetic acid and n-hexanol were studied in batch and continuous chromatographic reactors in the presence of a gelular ion-exchange resin catalyst (Purolite CT-124) to synthesize a value added ester, namely n-hexyl acetate. A laboratory scale batch chromatographic reactor column (BCRC) was designed and constructed. BCRC experiments were carried out using different parameters such as feed flow rate, feed mole ratio (FMR) of n-hexanol to acetic acid, desorbent (n-hexanol) flow rate, and reaction step time to maximize the formation of n-hexyl acetate as well as to achieve complete conversion of acetic acid. Samples were collected from the chromatographic reactor column (CRC) outlet at regular intervals and were analyzed by gas chromatography (GC). The continuous chromatographic reactor column (CCRC) was designed, constructed, and commissioned on the basis of the results obtained from the BCRC experiments. The experiments carried out in a CCRC correlate very well with the results obtained from the optimized reaction condition in a BCRC for maximum formation of n-hexyl acetate and complete conversion of acetic acid. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3007424 Exemplaires
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Titre : Reaction kinetics of the lignin conversion in supercritical water Type de document : texte imprimé Auteurs : Tau Len-Kelly Yong, Auteur ; Yukihiko Matsumura, Auteur Année de publication : 2012 Article en page(s) : pp. 11975–11988 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Kinetics Résumé : The effect of temperature (390–450 °C) and residence time (0.5–10 s) at a pressure of 25 MPa was investigated for lignin conversion in supercritical water (SCW) using a continuous flow apparatus designed to rapidly heat the system to the desired reaction temperature. Conversion of lignin in SCW occurs rapidly, and complete depolymerization can be achieved within a 5 s residence time. A high degree of depolymerization is achieved from rapid heating to supercritical temperatures. In addition, supercritical conditions result in a high yield of solid that does not significantly change with an increase in temperature or residence time. To test the suggested hypothesis that the formation of low molecular weight fragments and cross-linking of these fragments forms higher molecular weight fragments, the yield of char, gaseous products, phenolic compounds (phenol, guaiacol, catechol, o-cresol, m-cresol, and catechol) and aromatic hydrocarbons (benzene, toluene, and naphthalene) were determined. The formation of phenolic compounds at short residence time indicates that ether bonds in lignin are easily degraded under supercritical conditions. A reaction network model was proposed, and the subsequent kinetic parameters for the conversion pathways were determined by assuming a first-order reaction. It is observed that the rate constant of overall lignin conversion obeys Arrhenius behavior. The individual rate constants of each reaction in the network are evaluated to determine conformity to Arrhenius behavior. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300921d
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11975–11988[article] Reaction kinetics of the lignin conversion in supercritical water [texte imprimé] / Tau Len-Kelly Yong, Auteur ; Yukihiko Matsumura, Auteur . - 2012 . - pp. 11975–11988.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11975–11988
Mots-clés : Kinetics Résumé : The effect of temperature (390–450 °C) and residence time (0.5–10 s) at a pressure of 25 MPa was investigated for lignin conversion in supercritical water (SCW) using a continuous flow apparatus designed to rapidly heat the system to the desired reaction temperature. Conversion of lignin in SCW occurs rapidly, and complete depolymerization can be achieved within a 5 s residence time. A high degree of depolymerization is achieved from rapid heating to supercritical temperatures. In addition, supercritical conditions result in a high yield of solid that does not significantly change with an increase in temperature or residence time. To test the suggested hypothesis that the formation of low molecular weight fragments and cross-linking of these fragments forms higher molecular weight fragments, the yield of char, gaseous products, phenolic compounds (phenol, guaiacol, catechol, o-cresol, m-cresol, and catechol) and aromatic hydrocarbons (benzene, toluene, and naphthalene) were determined. The formation of phenolic compounds at short residence time indicates that ether bonds in lignin are easily degraded under supercritical conditions. A reaction network model was proposed, and the subsequent kinetic parameters for the conversion pathways were determined by assuming a first-order reaction. It is observed that the rate constant of overall lignin conversion obeys Arrhenius behavior. The individual rate constants of each reaction in the network are evaluated to determine conformity to Arrhenius behavior. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300921d Exemplaires
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Titre : Effect of sorbent type on the sorption enhanced water gas shift process in a fluidized bed reactor Type de document : texte imprimé Auteurs : Yang Liu, Auteur ; Zhenshan Li, Auteur ; Lei Xu, Auteur Année de publication : 2012 Article en page(s) : pp. 11989–11997 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Sorption water gas Résumé : reactions: the WGS reaction and the CaO carbonation reaction. The WGS reaction is a surface catalytic reaction, while the CaO carbonation is a bulk reaction. This study of the SEWGS reaction in a fluidized bed reactor showed that the sorbent type has an important effect on the SEWGS reaction, with both the CaO and MgO in the sorbent catalyzing the reaction. For calcined limestone, the WGS reaction occurs on the CaO surface with CO2 sorption in situ, but the reaction rate gradually decreases with the CaO conversion due to coverage by the CaCO3 product layer on the CaO surface. Thus, the shift reaction becomes the rate limiting step. For calcined dolomite, MgO in the sorbent does not react with CO2 and can then be used as a catalyst. The shift reaction is not a limiting step, with most of the CO2 for the CaO carbonation coming from the WGS reaction on the MgO surface. Even when the CaO surface is completely covered by the CaCO3 product, the MgO in the calcined dolomite is not completely covered by the CaCO3 product and can still catalyze the WGS reaction. An important phenomenon observed was that not only CaO but also MgO experienced the decay in the catalytic reactivity after multiple cycles. The decay of catalytic reactivity of MgO in dolomite is mainly the gradual covering of the MgO surface by CaO/CaCO3 grains, so most of the MgO grains will lose contact with the CO and the steam in the gas phase. The observation of encapsulation of MgO particles by CaO or CaCO3 is also important for understanding the stabilization of synthetic calcium based sorbent with support addition. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301100y
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11989–11997[article] Effect of sorbent type on the sorption enhanced water gas shift process in a fluidized bed reactor [texte imprimé] / Yang Liu, Auteur ; Zhenshan Li, Auteur ; Lei Xu, Auteur . - 2012 . - pp. 11989–11997.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11989–11997
Mots-clés : Sorption water gas Résumé : reactions: the WGS reaction and the CaO carbonation reaction. The WGS reaction is a surface catalytic reaction, while the CaO carbonation is a bulk reaction. This study of the SEWGS reaction in a fluidized bed reactor showed that the sorbent type has an important effect on the SEWGS reaction, with both the CaO and MgO in the sorbent catalyzing the reaction. For calcined limestone, the WGS reaction occurs on the CaO surface with CO2 sorption in situ, but the reaction rate gradually decreases with the CaO conversion due to coverage by the CaCO3 product layer on the CaO surface. Thus, the shift reaction becomes the rate limiting step. For calcined dolomite, MgO in the sorbent does not react with CO2 and can then be used as a catalyst. The shift reaction is not a limiting step, with most of the CO2 for the CaO carbonation coming from the WGS reaction on the MgO surface. Even when the CaO surface is completely covered by the CaCO3 product, the MgO in the calcined dolomite is not completely covered by the CaCO3 product and can still catalyze the WGS reaction. An important phenomenon observed was that not only CaO but also MgO experienced the decay in the catalytic reactivity after multiple cycles. The decay of catalytic reactivity of MgO in dolomite is mainly the gradual covering of the MgO surface by CaO/CaCO3 grains, so most of the MgO grains will lose contact with the CO and the steam in the gas phase. The observation of encapsulation of MgO particles by CaO or CaCO3 is also important for understanding the stabilization of synthetic calcium based sorbent with support addition. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301100y Exemplaires
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Titre : Selective degradation of orange II with the cobalt (II) – bicarbonate – hydrogen peroxide system Type de document : texte imprimé Auteurs : Xuejun Long, Auteur ; Zhen Yang, Auteur ; Hong Wang, Auteur Année de publication : 2012 Article en page(s) : pp. 11998–12003 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Catalyst Résumé : A simple and efficient approach to orange II (AOII) degradation using Co2+–HCO3– system as the catalyst and H2O2 as the oxidant under mild reaction conditions was reported. Complete decolorization of 50 μM AOII was observed with 5 μM Co2+ ions and 4 mM H2O2 in 10 mM NaHCO3 aqueous solution after 10 min, which was much faster that that of Fenton reagent with 50 μM Fe2+ ions. Some intermediate products such as carboxylic acids were detected by electrospray ionization-ion trap mass spectrometry and ion chromatography. In the presence of other pollutants such as methylene blue, sulforhodamine B, and a significant amount of anions including Cl–, CO32–, SO42–, NO3–, HPO42–, and CH3COO–, AOII was still rapidly degraded. The results of photoluminescence probing technology, electron spin resonance spin-trapping technology, and radical trap experiments indicated that the tightly associated hydroxyl radicals with the cobalt complex were the reactive species for AOII degradation. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3013924
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11998–12003[article] Selective degradation of orange II with the cobalt (II) – bicarbonate – hydrogen peroxide system [texte imprimé] / Xuejun Long, Auteur ; Zhen Yang, Auteur ; Hong Wang, Auteur . - 2012 . - pp. 11998–12003.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11998–12003
Mots-clés : Catalyst Résumé : A simple and efficient approach to orange II (AOII) degradation using Co2+–HCO3– system as the catalyst and H2O2 as the oxidant under mild reaction conditions was reported. Complete decolorization of 50 μM AOII was observed with 5 μM Co2+ ions and 4 mM H2O2 in 10 mM NaHCO3 aqueous solution after 10 min, which was much faster that that of Fenton reagent with 50 μM Fe2+ ions. Some intermediate products such as carboxylic acids were detected by electrospray ionization-ion trap mass spectrometry and ion chromatography. In the presence of other pollutants such as methylene blue, sulforhodamine B, and a significant amount of anions including Cl–, CO32–, SO42–, NO3–, HPO42–, and CH3COO–, AOII was still rapidly degraded. The results of photoluminescence probing technology, electron spin resonance spin-trapping technology, and radical trap experiments indicated that the tightly associated hydroxyl radicals with the cobalt complex were the reactive species for AOII degradation. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3013924 Exemplaires
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Titre : Combustion synthesis of a nickel supported catalyst : Effect of metal distribution on the activity during ethanol decomposition Type de document : texte imprimé Auteurs : Allison Cross, Auteur ; Anand Kumar, Auteur ; Eduardo E. Wolf, Auteur Année de publication : 2012 Article en page(s) : pp. 12004–12008 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Catalyst Ethanol Résumé : Solution combustion synthesis method is used to prepare Ni catalysts supported on γ-Al2O3 pellets with controlled metal distribution. It was shown that impregnation time of the SCS solution onto the pellet determines the distribution of the Ni in the pellet which in turn affects the catalyst selectivity toward hydrogen production during ethanol decomposition. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301478n
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12004–12008[article] Combustion synthesis of a nickel supported catalyst : Effect of metal distribution on the activity during ethanol decomposition [texte imprimé] / Allison Cross, Auteur ; Anand Kumar, Auteur ; Eduardo E. Wolf, Auteur . - 2012 . - pp. 12004–12008.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12004–12008
Mots-clés : Catalyst Ethanol Résumé : Solution combustion synthesis method is used to prepare Ni catalysts supported on γ-Al2O3 pellets with controlled metal distribution. It was shown that impregnation time of the SCS solution onto the pellet determines the distribution of the Ni in the pellet which in turn affects the catalyst selectivity toward hydrogen production during ethanol decomposition. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301478n Exemplaires
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Titre : Thermal degradation and flame retardance of biobased polylactide composites based on aluminum hypophosphite Type de document : texte imprimé Auteurs : Gang Tang, Auteur ; Xin Wang, Auteur ; Weiyi Xing, Auteur Année de publication : 2012 Article en page(s) : pp. 12009–12016 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Thermal behavior Polylactide Résumé : A series of flame retardant polylactide composites (FR-PLA) based on aluminum hypophosphite (AHP) were facilely prepared by melt blending method. The thermal behavior, flammability, and mechanical properties of FR-PLA composites were investigated by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), the UL-94 vertical burning test, limiting oxygen index (LOI), cone calorimeter testing, microscale combustion calorimetry, mechanical testing, and dynamic mechanical analysis (DMA). TGA results showed that the FR-PLA composites presented higher char residue and reduced mass loss rate than neat PLA. The FR-PLA composite showed excellent fire resistance, from no rating of neat PLA to a V0 rating of FR-PLA containing 20 wt % aluminum hypophosphite in the UL-94 test. The microscale combustion calorimetry test showed that the heat release capacity, the peak of heat release and the total heat release of FR-PLA composites were significantly decreased with the increase of AHP content. The cone calorimeter test also confirmed that the addition of AHP resulted in a significant decrease in the peak heat release rate value of PLA/AHP composites compared with pure PLA. Additionally, the results from DSC and DMA tests indicated that the addition of AHP into polylactide significantly changed the crystallization behavior and storage modulus of polylactide. However, the addition of AHP decreases the tensile strength and elongation at break. The char after LOI testing was investigated by scanning electron microscopy and craterlike morphology was observed on the surface of the char. The thermal degradation process of FR-PLA composites was analyzed by real-time Fourier transform infrared spectroscopy. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3008133
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12009–12016[article] Thermal degradation and flame retardance of biobased polylactide composites based on aluminum hypophosphite [texte imprimé] / Gang Tang, Auteur ; Xin Wang, Auteur ; Weiyi Xing, Auteur . - 2012 . - pp. 12009–12016.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12009–12016
Mots-clés : Thermal behavior Polylactide Résumé : A series of flame retardant polylactide composites (FR-PLA) based on aluminum hypophosphite (AHP) were facilely prepared by melt blending method. The thermal behavior, flammability, and mechanical properties of FR-PLA composites were investigated by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), the UL-94 vertical burning test, limiting oxygen index (LOI), cone calorimeter testing, microscale combustion calorimetry, mechanical testing, and dynamic mechanical analysis (DMA). TGA results showed that the FR-PLA composites presented higher char residue and reduced mass loss rate than neat PLA. The FR-PLA composite showed excellent fire resistance, from no rating of neat PLA to a V0 rating of FR-PLA containing 20 wt % aluminum hypophosphite in the UL-94 test. The microscale combustion calorimetry test showed that the heat release capacity, the peak of heat release and the total heat release of FR-PLA composites were significantly decreased with the increase of AHP content. The cone calorimeter test also confirmed that the addition of AHP resulted in a significant decrease in the peak heat release rate value of PLA/AHP composites compared with pure PLA. Additionally, the results from DSC and DMA tests indicated that the addition of AHP into polylactide significantly changed the crystallization behavior and storage modulus of polylactide. However, the addition of AHP decreases the tensile strength and elongation at break. The char after LOI testing was investigated by scanning electron microscopy and craterlike morphology was observed on the surface of the char. The thermal degradation process of FR-PLA composites was analyzed by real-time Fourier transform infrared spectroscopy. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3008133 Exemplaires
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Titre : Facile approach for superparamagnetic CNT - Fe3O4 / polystyrene tricomponent nanocomposite via synergetic dispersion Type de document : texte imprimé Auteurs : Wu Zhong, Auteur ; Peng Liu, Auteur ; Zhaobin Tang, Auteur Année de publication : 2012 Article en page(s) : pp. 12017–12024 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Nanocomposite Synergetic dispersion Résumé : A facile one-pot in-situ radical bulk polymerization strategy was developed for preparation of the superparamagnetic multiwalled carbon nanotubes-Fe3O4/polystyrene (CNT-Fe3O4/PS) tricomponent nanocomposite by the synergetic dispersion strategy via the multiwalled carbon nanotubes (CNT) immobilized Fe3O4 nanoparticles (CNT-Fe3O4) with oleic acid (OA) as surface modifier. Compared with the tricomponent nanocomposite prepared with the multiwalled carbon nanotubes and Fe3O4 nanoparticles added separately, immobilization of Fe3O4 nanoparticles on multiwalled carbon nanotubes could avoid efficiently aggregation of the Fe3O4 nanoparticles in polymer matrices. OA molecules adsorb onto the surfaces of the Fe3O4 nanoparticles immobilized on the multiwalled carbon nanotubes, improving efficiently the dispersibility of the multiwalled carbon nanotubes in styrene, which resulted in the well-dispersed CNT-Fe3O4/PS tricomponent nanocomposite. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300891h
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12017–12024[article] Facile approach for superparamagnetic CNT - Fe3O4 / polystyrene tricomponent nanocomposite via synergetic dispersion [texte imprimé] / Wu Zhong, Auteur ; Peng Liu, Auteur ; Zhaobin Tang, Auteur . - 2012 . - pp. 12017–12024.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12017–12024
Mots-clés : Nanocomposite Synergetic dispersion Résumé : A facile one-pot in-situ radical bulk polymerization strategy was developed for preparation of the superparamagnetic multiwalled carbon nanotubes-Fe3O4/polystyrene (CNT-Fe3O4/PS) tricomponent nanocomposite by the synergetic dispersion strategy via the multiwalled carbon nanotubes (CNT) immobilized Fe3O4 nanoparticles (CNT-Fe3O4) with oleic acid (OA) as surface modifier. Compared with the tricomponent nanocomposite prepared with the multiwalled carbon nanotubes and Fe3O4 nanoparticles added separately, immobilization of Fe3O4 nanoparticles on multiwalled carbon nanotubes could avoid efficiently aggregation of the Fe3O4 nanoparticles in polymer matrices. OA molecules adsorb onto the surfaces of the Fe3O4 nanoparticles immobilized on the multiwalled carbon nanotubes, improving efficiently the dispersibility of the multiwalled carbon nanotubes in styrene, which resulted in the well-dispersed CNT-Fe3O4/PS tricomponent nanocomposite. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300891h Exemplaires
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Titre : A General phase - transfer protocol for mineral acids and its application in the large - scale synthesis of highly nanoporous iron phosphate in nonaqueous solvent Type de document : texte imprimé Auteurs : Junmei Zhao, Auteur ; Jie Ma, Auteur ; Zelang Jian, Auteur Année de publication : 2012 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Nanoporous Iron Résumé : As a general protocol for transferring mineral acids from an aqueous solution to an organic phase, mineral acids are extracted with secondary carbon primary amine (C9–11)2CHNH2 (commercial code: N1923) into an organic phase (e.g., heptane or benzene) because of the complexation reaction and the formation of typical reversed micelles. Based on this principle, a novel approach for a large-scale synthesis of highly nanoporous iron phosphate particles is developed via the formed RNH3+/H2PO4– (H2O)/oil reversed micelle system and ethanol–Fe3+ solutions. Synthetic conditions, such as H3PO4 concentration in reversed micelles and Fe3+ concentration in ethanol–Fe3+ solution are investigated and optimized. The product is characterized using transmission electron microscopy, Brunauer–Emett–Teller, thermogravimetric analysis, X-ray diffraction, and Fourier transform infrared spectroscopy. The as-obtained iron phosphate is flocculent and highly porous, exhibiting a high reported surface area of 144 m2/g. The synthetic procedure is relatively simple and is suitable for large-scale fabrication, and the used organic amines can be recycled. The power of this approach is demonstrated using other kinds of organic amines, such as tri-n-octylamine (TOA) and tri-C8–10-alkylmethyl ammonium chloride (N263), as phase-transfer reagents exhibiting promising application in the synthesis of highly nanoporous materials. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3016285
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012)[article] A General phase - transfer protocol for mineral acids and its application in the large - scale synthesis of highly nanoporous iron phosphate in nonaqueous solvent [texte imprimé] / Junmei Zhao, Auteur ; Jie Ma, Auteur ; Zelang Jian, Auteur . - 2012.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012)
Mots-clés : Nanoporous Iron Résumé : As a general protocol for transferring mineral acids from an aqueous solution to an organic phase, mineral acids are extracted with secondary carbon primary amine (C9–11)2CHNH2 (commercial code: N1923) into an organic phase (e.g., heptane or benzene) because of the complexation reaction and the formation of typical reversed micelles. Based on this principle, a novel approach for a large-scale synthesis of highly nanoporous iron phosphate particles is developed via the formed RNH3+/H2PO4– (H2O)/oil reversed micelle system and ethanol–Fe3+ solutions. Synthetic conditions, such as H3PO4 concentration in reversed micelles and Fe3+ concentration in ethanol–Fe3+ solution are investigated and optimized. The product is characterized using transmission electron microscopy, Brunauer–Emett–Teller, thermogravimetric analysis, X-ray diffraction, and Fourier transform infrared spectroscopy. The as-obtained iron phosphate is flocculent and highly porous, exhibiting a high reported surface area of 144 m2/g. The synthetic procedure is relatively simple and is suitable for large-scale fabrication, and the used organic amines can be recycled. The power of this approach is demonstrated using other kinds of organic amines, such as tri-n-octylamine (TOA) and tri-C8–10-alkylmethyl ammonium chloride (N263), as phase-transfer reagents exhibiting promising application in the synthesis of highly nanoporous materials. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3016285 Exemplaires
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Titre : Diblock poly(ester) - poly (ester - ether) copolymers : I. Synthesis, thermal properties, and degradation kinetics Type de document : texte imprimé Auteurs : Nowsheen Goonoo, Auteur ; Archana Bhaw-Luximon, Auteur ; Gary L. Bowlin, Auteur Année de publication : 2012 Article en page(s) : pp. 12031–12040 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Thermal Properties Kinetics Résumé : The synthesis and characterization of polycaprolactone (PCL) and poly(dioxanone-methyl dioxanone) (P(DX-co-MeDX)) block copolymers in a range of compositions of the two segments and with varying methyl dioxanone units is herein reported. The thermal properties of the copolymers were studied by differential scanning calorimetry (DSC) which revealed that copolymers exhibited two melting transitions ranging between 48 and 53 °C for the PCL segment and 71–79 °C for the P(DX-co-MeDX) segment. Copolymers exhibited only one crystallization exotherm which decreased as the MeDX content of the copolymer increased, thereby increasing miscibility of PCL and P(DX-co-MeDX) segments, a result also confirmed by scanning electron micrographs (SEM). Lastly, the kinetics of thermal degradation of PCL-b-P(DX-co-MeDX) copolymers were investigated by thermogravimetric analysis (TGA). Thermal degradation was shown to proceed in three distinct steps with the P(DX-co-MeDX) segment degrading in the first stage followed by the PCL segment in the last two stages most likely via unzipping and random polymerization mechanisms. The activation energies of copolymer degradation were determined and were found to decrease with increasing MeDX content of the copolymer. Overall, increasing MeDX content influenced both thermal properties and degradation kinetics through phase mixing of segments in the copolymers. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301703j
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12031–12040[article] Diblock poly(ester) - poly (ester - ether) copolymers : I. Synthesis, thermal properties, and degradation kinetics [texte imprimé] / Nowsheen Goonoo, Auteur ; Archana Bhaw-Luximon, Auteur ; Gary L. Bowlin, Auteur . - 2012 . - pp. 12031–12040.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12031–12040
Mots-clés : Thermal Properties Kinetics Résumé : The synthesis and characterization of polycaprolactone (PCL) and poly(dioxanone-methyl dioxanone) (P(DX-co-MeDX)) block copolymers in a range of compositions of the two segments and with varying methyl dioxanone units is herein reported. The thermal properties of the copolymers were studied by differential scanning calorimetry (DSC) which revealed that copolymers exhibited two melting transitions ranging between 48 and 53 °C for the PCL segment and 71–79 °C for the P(DX-co-MeDX) segment. Copolymers exhibited only one crystallization exotherm which decreased as the MeDX content of the copolymer increased, thereby increasing miscibility of PCL and P(DX-co-MeDX) segments, a result also confirmed by scanning electron micrographs (SEM). Lastly, the kinetics of thermal degradation of PCL-b-P(DX-co-MeDX) copolymers were investigated by thermogravimetric analysis (TGA). Thermal degradation was shown to proceed in three distinct steps with the P(DX-co-MeDX) segment degrading in the first stage followed by the PCL segment in the last two stages most likely via unzipping and random polymerization mechanisms. The activation energies of copolymer degradation were determined and were found to decrease with increasing MeDX content of the copolymer. Overall, increasing MeDX content influenced both thermal properties and degradation kinetics through phase mixing of segments in the copolymers. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301703j Exemplaires
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Titre : Process and cost modeling of saturated branched - chain fatty acid isomer production Type de document : texte imprimé Auteurs : Helen L. Ngo, Auteur ; Winnie C. Yee, Auteur ; Andrew J. McAloon, Auteur Année de publication : 2012 Article en page(s) : pp. 12041–12045 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Modeling Acid Isomer Résumé : For decades, lubricants and hydraulic fluids were almost entirely based on petroleum. In recent years, the potential health risks of these materials as a result of their poor biodegradability have stimulated public awareness and concerns. It is therefore becoming increasingly important to implement environmentally friendly biobased fluids for the chemical industries. The development of new heterogeneous chemocatalytic processes for the conversion of vegetable oils and animal fats into high-value biobased industrial products can also have important positive impacts on the U.S. agriculture industry. Saturated branched-chain fatty acid isomers (sbc-FAs) such as isostearic acid, which are produced from renewable materials, are of interest because of their excellent lubricity and potentially good biodegradability. These unique features make them attractive in many important applications. Currently, sbc-FAs are produced as a byproduct of industrial dimer acid production, are synthesized in small quantities, and are costly to produce. In this paper, an efficient and effective isomerization process that produces predominantly the sbc-FA materials is presented as a case study to evaluate the potential of the technology to be implemented on the industrial scale. The case study was simulated using SuperPro Designer software to estimate the capital and process costs for producing sbc-FAs at an annual production of 4.5 × 106 kg (10 × 106 lb). The studies show that the process is cost-effective, with an estimated production cost of U.S. $2.53 kg–1 ($1.15 lb–1). ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300451x
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12041–12045[article] Process and cost modeling of saturated branched - chain fatty acid isomer production [texte imprimé] / Helen L. Ngo, Auteur ; Winnie C. Yee, Auteur ; Andrew J. McAloon, Auteur . - 2012 . - pp. 12041–12045.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12041–12045
Mots-clés : Modeling Acid Isomer Résumé : For decades, lubricants and hydraulic fluids were almost entirely based on petroleum. In recent years, the potential health risks of these materials as a result of their poor biodegradability have stimulated public awareness and concerns. It is therefore becoming increasingly important to implement environmentally friendly biobased fluids for the chemical industries. The development of new heterogeneous chemocatalytic processes for the conversion of vegetable oils and animal fats into high-value biobased industrial products can also have important positive impacts on the U.S. agriculture industry. Saturated branched-chain fatty acid isomers (sbc-FAs) such as isostearic acid, which are produced from renewable materials, are of interest because of their excellent lubricity and potentially good biodegradability. These unique features make them attractive in many important applications. Currently, sbc-FAs are produced as a byproduct of industrial dimer acid production, are synthesized in small quantities, and are costly to produce. In this paper, an efficient and effective isomerization process that produces predominantly the sbc-FA materials is presented as a case study to evaluate the potential of the technology to be implemented on the industrial scale. The case study was simulated using SuperPro Designer software to estimate the capital and process costs for producing sbc-FAs at an annual production of 4.5 × 106 kg (10 × 106 lb). The studies show that the process is cost-effective, with an estimated production cost of U.S. $2.53 kg–1 ($1.15 lb–1). ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300451x Exemplaires
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Titre : Comparison of dimethyl disulfide and carbon disulfide in sulfurization of activated carbons for producing mercury adsorbents Type de document : texte imprimé Auteurs : Neda Asasian, Auteur ; Tahereh Kaghazchi, Auteur Année de publication : 2012 Article en page(s) : pp. 12046–12057 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Activated carbons Adsorbents Résumé : In this work, the use of dimethyl disulfide (DMDS) as a sulfurizing impregnator for producing mercury adsorbents for the first time has been investigated and compared with CS2, one of the materials commonly used in this field. Sulfurized adsorbents were characterized by CHNS/O elemental analysis, N2 adsorption/desorption, XPS, and FT-IR spectroscopy. The sulfur contents of CS2 and DMDS modified activated carbons were about 3.2 and 9.6 wt %, respectively. The impregnated sulfur was found in two major organic and elemental forms in granular activated carbon modified with DMDS; however, elemental sulfur was not observed in the case modified with CS2. After comparing the equilibrium capacities and the rates of mercury adsorption, the occurrence of sulfur leaching from the sulfurized adsorbents during the adsorption processes was studied. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3001474
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12046–12057[article] Comparison of dimethyl disulfide and carbon disulfide in sulfurization of activated carbons for producing mercury adsorbents [texte imprimé] / Neda Asasian, Auteur ; Tahereh Kaghazchi, Auteur . - 2012 . - pp. 12046–12057.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12046–12057
Mots-clés : Activated carbons Adsorbents Résumé : In this work, the use of dimethyl disulfide (DMDS) as a sulfurizing impregnator for producing mercury adsorbents for the first time has been investigated and compared with CS2, one of the materials commonly used in this field. Sulfurized adsorbents were characterized by CHNS/O elemental analysis, N2 adsorption/desorption, XPS, and FT-IR spectroscopy. The sulfur contents of CS2 and DMDS modified activated carbons were about 3.2 and 9.6 wt %, respectively. The impregnated sulfur was found in two major organic and elemental forms in granular activated carbon modified with DMDS; however, elemental sulfur was not observed in the case modified with CS2. After comparing the equilibrium capacities and the rates of mercury adsorption, the occurrence of sulfur leaching from the sulfurized adsorbents during the adsorption processes was studied. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3001474 Exemplaires
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Titre : Investigation of mass - transfer performance for CO2 absorption into diethylenetriamine (DETA) in a randomly packed column Type de document : texte imprimé Auteurs : Kaiyun Fu, Auteur ; Teerawat Sema, Auteur ; Zhiwu Liang, Auteur Année de publication : 2012 Article en page(s) : pp. 12058–12064 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Mass transfer CO2 Absorption Résumé : The mass-transfer performance of CO2 absorption into aqueous diethylenetriamine (DETA) solutions was investigated in an absorption column randomly packed with Dixon rings at 303–303 K and atmospheric pressure, and compared with that of monoethanolamine (MEA), which is widely considered as a benchmark solvent for CO2 absorption. The mass-transfer performance was presented in terms of volumetric overall mass-transfer coefficient (KGav). In particular, the effects of operating parameters, such as inlet CO2 loading, solvent concentration, liquid flow rate, inert gas flow rate, and liquid temperature, were investigated and compared for both MEA and DETA. Over 40 runs of absorption experiments were carried out in this study. The results showed that KGav of DETA was found to be higher than that of MEA. Also, inlet CO2 loading, solvent concentration, liquid flow rate, and liquid inlet temperature had significant effect on KGav for both systems. However, the inert gas flow rate had an insignificant effect on KGav. Lastly, predictive correlations for KGav for DETA–CO2 and MEA–CO2 systems in randomly Dixon ring packed columns were successfully developed. The predicted results were found to be in relatively good agreement with the experimental results, with average absolute deviations (AADs) of 16% and 14%, respectively. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300830h
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12058–12064[article] Investigation of mass - transfer performance for CO2 absorption into diethylenetriamine (DETA) in a randomly packed column [texte imprimé] / Kaiyun Fu, Auteur ; Teerawat Sema, Auteur ; Zhiwu Liang, Auteur . - 2012 . - pp. 12058–12064.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12058–12064
Mots-clés : Mass transfer CO2 Absorption Résumé : The mass-transfer performance of CO2 absorption into aqueous diethylenetriamine (DETA) solutions was investigated in an absorption column randomly packed with Dixon rings at 303–303 K and atmospheric pressure, and compared with that of monoethanolamine (MEA), which is widely considered as a benchmark solvent for CO2 absorption. The mass-transfer performance was presented in terms of volumetric overall mass-transfer coefficient (KGav). In particular, the effects of operating parameters, such as inlet CO2 loading, solvent concentration, liquid flow rate, inert gas flow rate, and liquid temperature, were investigated and compared for both MEA and DETA. Over 40 runs of absorption experiments were carried out in this study. The results showed that KGav of DETA was found to be higher than that of MEA. Also, inlet CO2 loading, solvent concentration, liquid flow rate, and liquid inlet temperature had significant effect on KGav for both systems. However, the inert gas flow rate had an insignificant effect on KGav. Lastly, predictive correlations for KGav for DETA–CO2 and MEA–CO2 systems in randomly Dixon ring packed columns were successfully developed. The predicted results were found to be in relatively good agreement with the experimental results, with average absolute deviations (AADs) of 16% and 14%, respectively. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300830h Exemplaires
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Titre : Study on mass transfer - reaction kinetics of NO removal from flue gas by using a UV / fenton - like reaction Type de document : texte imprimé Auteurs : Yangxian Liu, Auteur ; Jianfeng Pan, Auteur ; Jun Zhang, Auteur Année de publication : 2012 Article en page(s) : pp. 12065–12072 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Mass transfer Kinetics Résumé : The mass transfer-reaction kinetics of NO removal from flue gas by using a UV/Fenton-like reaction was investigated in a lab-scale UV-bubbling column reactor. The results show that the NO absorption rate increases with the increase of UV radiation intensity and H2O2 concentration, but the growth rates become smaller gradually. NO absorption rates increase with the increase of Cu2+ concentration and NO concentration but decrease with the increase of SO2 concentration. The absorption of NO by using a UV/Fenton-like reaction is a pseudo-first-order fast reaction with respect to NO, thus the chemical reaction rate of NO removal is much larger than the mass transfer rate, and the mass transfer process is the main control step of the NO absorption process. NO absorption can be further strengthened by increasing the gas phase mass transfer coefficient, the gas–liquid specific interfacial area, and the NO partial pressure. The validation results of the NO absorption rate equation indicate that the calculated values are in good agreement with the experimental values. The maximal average error is less than 2.0%, and the maximal error is less than 10.1% between the calculated values and the experimental values. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300883f
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12065–12072[article] Study on mass transfer - reaction kinetics of NO removal from flue gas by using a UV / fenton - like reaction [texte imprimé] / Yangxian Liu, Auteur ; Jianfeng Pan, Auteur ; Jun Zhang, Auteur . - 2012 . - pp. 12065–12072.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12065–12072
Mots-clés : Mass transfer Kinetics Résumé : The mass transfer-reaction kinetics of NO removal from flue gas by using a UV/Fenton-like reaction was investigated in a lab-scale UV-bubbling column reactor. The results show that the NO absorption rate increases with the increase of UV radiation intensity and H2O2 concentration, but the growth rates become smaller gradually. NO absorption rates increase with the increase of Cu2+ concentration and NO concentration but decrease with the increase of SO2 concentration. The absorption of NO by using a UV/Fenton-like reaction is a pseudo-first-order fast reaction with respect to NO, thus the chemical reaction rate of NO removal is much larger than the mass transfer rate, and the mass transfer process is the main control step of the NO absorption process. NO absorption can be further strengthened by increasing the gas phase mass transfer coefficient, the gas–liquid specific interfacial area, and the NO partial pressure. The validation results of the NO absorption rate equation indicate that the calculated values are in good agreement with the experimental values. The maximal average error is less than 2.0%, and the maximal error is less than 10.1% between the calculated values and the experimental values. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300883f Exemplaires
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Titre : High - flux MFI zeolite membrane supported on YSZ hollow fiber for separation of ethanol / water Type de document : texte imprimé Auteurs : Xiaojun Shu, Auteur ; Xuerui Wang, Auteur ; Qingqing Kong, Auteur Année de publication : 2012 Article en page(s) : pp 12073–12080 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Zeolite Ethanol Résumé : Pure-silica MFI zeolite (silicalite-1) membranes exhibit great potential in the separation of an ethanol/water mixtures. For synthesis of silicalite membranes, however, conventional supports such as α-Al2O3 and mullite have aluminum element leaching out and entering into a zeolite structure, which would reduce the hydrophobicity of the zeolite layer and thus affect the separation performance for ethanol selectivity. In this paper, we prepared silicalite membranes on hollow fiber substrates fabricated with yttria stabilized zirconia (YSZ) without aluminum. The influence of seed size, synthesis parameters, and substrates was investigated. The as-synthesized membranes were characterized by scanning electron microscopy (SEM), electron probe microanalyzer (EPMA), infrared spectrum analysis (IR), and X-ray diffraction (XRD). A thin MFI zeolite layer with a thickness of about 3 μm could be formed on the support, which exhibited highly selective to ethanol over water. A high flux of 7.4 kg m–2 h–1 with the separation factor (ethanol/water) of 47 was achieved on the as-made membrane for separating 5 wt % ethanol/water at 60 °C. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301087u
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp 12073–12080[article] High - flux MFI zeolite membrane supported on YSZ hollow fiber for separation of ethanol / water [texte imprimé] / Xiaojun Shu, Auteur ; Xuerui Wang, Auteur ; Qingqing Kong, Auteur . - 2012 . - pp 12073–12080.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp 12073–12080
Mots-clés : Zeolite Ethanol Résumé : Pure-silica MFI zeolite (silicalite-1) membranes exhibit great potential in the separation of an ethanol/water mixtures. For synthesis of silicalite membranes, however, conventional supports such as α-Al2O3 and mullite have aluminum element leaching out and entering into a zeolite structure, which would reduce the hydrophobicity of the zeolite layer and thus affect the separation performance for ethanol selectivity. In this paper, we prepared silicalite membranes on hollow fiber substrates fabricated with yttria stabilized zirconia (YSZ) without aluminum. The influence of seed size, synthesis parameters, and substrates was investigated. The as-synthesized membranes were characterized by scanning electron microscopy (SEM), electron probe microanalyzer (EPMA), infrared spectrum analysis (IR), and X-ray diffraction (XRD). A thin MFI zeolite layer with a thickness of about 3 μm could be formed on the support, which exhibited highly selective to ethanol over water. A high flux of 7.4 kg m–2 h–1 with the separation factor (ethanol/water) of 47 was achieved on the as-made membrane for separating 5 wt % ethanol/water at 60 °C. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301087u Exemplaires
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Titre : Dynamics of CO2 absorption and desorption processes in alkanolamine with cosolvent polyethylene glycol Type de document : texte imprimé Auteurs : Jun Li, Auteur ; Chenjia You, Auteur ; Lifang Chen, Auteur Année de publication : 2012 Article en page(s) : pp. 12081–12088 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Dynamics Absorption Résumé : To reduce the high energy consumption and equipment corrosion in conventional processes of CO2 capture with aqueous amine solutions, the mixed nonaqueous solvents of monoethanolamine (MEA), diethanolamine (DEA), and diglycolamine (DGA) with polyethylene glycol (PEG) as cosolvent were explored for CO2 capture. The dynamic experiments of CO2 absorption and desorption were carried out to evaluate the performance of the studied nonaqueous solutions. It demonstrated that the mixed solutions of amines and PEG exhibited higher CO2 cyclic capacity and regeneration efficiency compared with the only aqueous amine solutions. Especially, the solution of 3 mol/L DGA-PEG200 exhibits a high cyclic capacity of 0.438 mol CO2/mol DGA and a high regeneration efficiency of 94.6%, which indicates its great potential in industrial application. Moreover, the very low vapor pressure of PEG helps the mixed solution for CO2 capture with reduced corrosion, energy consumption, and environmental pollution. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301164v
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12081–12088[article] Dynamics of CO2 absorption and desorption processes in alkanolamine with cosolvent polyethylene glycol [texte imprimé] / Jun Li, Auteur ; Chenjia You, Auteur ; Lifang Chen, Auteur . - 2012 . - pp. 12081–12088.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12081–12088
Mots-clés : Dynamics Absorption Résumé : To reduce the high energy consumption and equipment corrosion in conventional processes of CO2 capture with aqueous amine solutions, the mixed nonaqueous solvents of monoethanolamine (MEA), diethanolamine (DEA), and diglycolamine (DGA) with polyethylene glycol (PEG) as cosolvent were explored for CO2 capture. The dynamic experiments of CO2 absorption and desorption were carried out to evaluate the performance of the studied nonaqueous solutions. It demonstrated that the mixed solutions of amines and PEG exhibited higher CO2 cyclic capacity and regeneration efficiency compared with the only aqueous amine solutions. Especially, the solution of 3 mol/L DGA-PEG200 exhibits a high cyclic capacity of 0.438 mol CO2/mol DGA and a high regeneration efficiency of 94.6%, which indicates its great potential in industrial application. Moreover, the very low vapor pressure of PEG helps the mixed solution for CO2 capture with reduced corrosion, energy consumption, and environmental pollution. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301164v Exemplaires
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Titre : Solution chemistry of sodium silicate and implications for pyrite flotation Type de document : texte imprimé Auteurs : Bo Feng, Auteur ; Yiping Lu, Auteur ; Qiming Feng, Auteur Année de publication : 2012 Article en page(s) : pp. 12089–12094 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Solution chemistry Résumé : The solution chemistry of sodium silicate and implications for pyrite flotation have been studied. In addition to flotation and sedimentation tests, electrophoresis, inductively coupled plasma (ICP) tests, and X-ray photoelectron spectroscopy (XPS) have been used. The flotation and sedimentation results show that lizardite causes problems in the flotation of pyrite by adhering to the pyrite particles. Addition of the sodium silicate could make the mixed sample of pyrite and lizardite more disperse in the alkaline condition and significantly reduce the adverse effect of lizardite on the flotation of pyrite. ICP tests and XPS analysises show that sodium silicate can adsorb onto the lizardite surface and change the surface characteristic of lizardite. Sodium silicate mainly exists in the form of SiO(OH)3– in the pH range that sodium silicate can restore pyrite flotation recovery. The adsorption of SiO(OH)3– ions at the lizardite/solution interface overcompensates the positive charge on the lizardite particle and its ζ potential is rendered negative. The total interaction energy between lizardite and pyrite is changed from attractive energy to repulsive energy in the presence of sodium silicate, according to the calculation of the Derjaguin–Landau–Verwey–Overbeek theory. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301307a
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12089–12094[article] Solution chemistry of sodium silicate and implications for pyrite flotation [texte imprimé] / Bo Feng, Auteur ; Yiping Lu, Auteur ; Qiming Feng, Auteur . - 2012 . - pp. 12089–12094.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12089–12094
Mots-clés : Solution chemistry Résumé : The solution chemistry of sodium silicate and implications for pyrite flotation have been studied. In addition to flotation and sedimentation tests, electrophoresis, inductively coupled plasma (ICP) tests, and X-ray photoelectron spectroscopy (XPS) have been used. The flotation and sedimentation results show that lizardite causes problems in the flotation of pyrite by adhering to the pyrite particles. Addition of the sodium silicate could make the mixed sample of pyrite and lizardite more disperse in the alkaline condition and significantly reduce the adverse effect of lizardite on the flotation of pyrite. ICP tests and XPS analysises show that sodium silicate can adsorb onto the lizardite surface and change the surface characteristic of lizardite. Sodium silicate mainly exists in the form of SiO(OH)3– in the pH range that sodium silicate can restore pyrite flotation recovery. The adsorption of SiO(OH)3– ions at the lizardite/solution interface overcompensates the positive charge on the lizardite particle and its ζ potential is rendered negative. The total interaction energy between lizardite and pyrite is changed from attractive energy to repulsive energy in the presence of sodium silicate, according to the calculation of the Derjaguin–Landau–Verwey–Overbeek theory. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301307a Exemplaires
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Titre : Adsorption of anionic - azo dye from aqueous solution by lignocellulose - biomass jute fiber : Equilibrium, kinetics, and thermodynamics study Type de document : texte imprimé Auteurs : Aparna Roy, Auteur ; Sumit Chakraborty, Auteur ; Sarada Prasad Kundu, Auteur Année de publication : 2012 Article en page(s) : pp. 12095–12106 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Adsorption Aqueous solution Kinetics Thermodynamics Résumé : The present investigation describes the evaluation of feasibility of lignocellulosic-biomass jute fiber (JF) toward adsorptive removal of anionic-azo dye from aqueous solution. Batch studies illustrated that dye uptake was highly dependent on different process variables, pH, initial dye concentration of solution, adsorbent dosage, and temperature. Further, an attempt has been taken to correlate these process variables with dye absorption and was optimized through a full-factorial central composite design (CCD) in response surface methodology (RSM). Maximum adsorption capacity (29.697 mg/g) under optimum conditions of variables (pH 3.91, adsorbent dose 2.04 g/L, adsorbate concentration 244.05 mg/L, and temperature 30 °C), as predicted by RSM, was found to be very close to the experimentally determined value (28.940 mg/g). Exothermic and spontaneous nature of adsorption was revealed from thermodynamic study. Equilibrium adsorption data were highly consistent with Langmuir isotherm yielding R2 = 0.999. Kinetic studies revealed that adsorption followed pseudo second-order model regarding the intraparticle diffusion. Activation parameters for the adsorption process were computed using Arrhenius and Eyring equations. Maximum desorption efficiency of spent adsorbent was achieved using sodium hydroxide solution (0.1 M). ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301708e
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12095–12106[article] Adsorption of anionic - azo dye from aqueous solution by lignocellulose - biomass jute fiber : Equilibrium, kinetics, and thermodynamics study [texte imprimé] / Aparna Roy, Auteur ; Sumit Chakraborty, Auteur ; Sarada Prasad Kundu, Auteur . - 2012 . - pp. 12095–12106.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12095–12106
Mots-clés : Adsorption Aqueous solution Kinetics Thermodynamics Résumé : The present investigation describes the evaluation of feasibility of lignocellulosic-biomass jute fiber (JF) toward adsorptive removal of anionic-azo dye from aqueous solution. Batch studies illustrated that dye uptake was highly dependent on different process variables, pH, initial dye concentration of solution, adsorbent dosage, and temperature. Further, an attempt has been taken to correlate these process variables with dye absorption and was optimized through a full-factorial central composite design (CCD) in response surface methodology (RSM). Maximum adsorption capacity (29.697 mg/g) under optimum conditions of variables (pH 3.91, adsorbent dose 2.04 g/L, adsorbate concentration 244.05 mg/L, and temperature 30 °C), as predicted by RSM, was found to be very close to the experimentally determined value (28.940 mg/g). Exothermic and spontaneous nature of adsorption was revealed from thermodynamic study. Equilibrium adsorption data were highly consistent with Langmuir isotherm yielding R2 = 0.999. Kinetic studies revealed that adsorption followed pseudo second-order model regarding the intraparticle diffusion. Activation parameters for the adsorption process were computed using Arrhenius and Eyring equations. Maximum desorption efficiency of spent adsorbent was achieved using sodium hydroxide solution (0.1 M). ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301708e Exemplaires
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Titre : Bubble size and frequency in corrugated - wall bubbling fluidized beds — image analysis and neural network correlations Type de document : texte imprimé Auteurs : A. N. Khan Wardag, Auteur ; F. Larachi, Auteur ; B.P.A. Grandjean, Auteur Année de publication : 2012 Article en page(s) : pp. 12107–12116 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Bubbling dynamics Résumé : Digital image analysis was implemented to monitor bubbling dynamics in corrugated-wall bubbling fluidized beds (CWBFB) loaded with Geldart D particles. Various geometrical configurations were investigated in terms of corrugation angle, interwall clearance, and rest bed height and gas superficial velocity. Implementation of wall corrugation led to improved gas–solid fluidization quality with respect to flat-wall bubbling fluidized beds (FWBFB) as measured in terms of retreat of the onset of bubbling as a function of gas flow rate, of reduction of bubble sizes and rise velocities, and of increase of bubble frequency. Two artificial neural network correlations valid both for FWBFB and CWBFB were recommended for estimation of bubble frequency and size using a common set of independent variables, that is, gas superficial-minimum bubbling velocity ratio, bed rest height, corrugation angle, average clearance, and vertical location. The bubble frequency explicit correlation accounted additionally for interwall minimum clearance and distance between side wall and either neck or hip of front plate, at a given elevation, whereas bubble size correlation needed bubble frequency as a supplementary input variable. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3007775
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12107–12116[article] Bubble size and frequency in corrugated - wall bubbling fluidized beds — image analysis and neural network correlations [texte imprimé] / A. N. Khan Wardag, Auteur ; F. Larachi, Auteur ; B.P.A. Grandjean, Auteur . - 2012 . - pp. 12107–12116.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12107–12116
Mots-clés : Bubbling dynamics Résumé : Digital image analysis was implemented to monitor bubbling dynamics in corrugated-wall bubbling fluidized beds (CWBFB) loaded with Geldart D particles. Various geometrical configurations were investigated in terms of corrugation angle, interwall clearance, and rest bed height and gas superficial velocity. Implementation of wall corrugation led to improved gas–solid fluidization quality with respect to flat-wall bubbling fluidized beds (FWBFB) as measured in terms of retreat of the onset of bubbling as a function of gas flow rate, of reduction of bubble sizes and rise velocities, and of increase of bubble frequency. Two artificial neural network correlations valid both for FWBFB and CWBFB were recommended for estimation of bubble frequency and size using a common set of independent variables, that is, gas superficial-minimum bubbling velocity ratio, bed rest height, corrugation angle, average clearance, and vertical location. The bubble frequency explicit correlation accounted additionally for interwall minimum clearance and distance between side wall and either neck or hip of front plate, at a given elevation, whereas bubble size correlation needed bubble frequency as a supplementary input variable. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3007775 Exemplaires
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Titre : Assessment of stability of spouted bed using pressure fluctuation analysis Type de document : texte imprimé Auteurs : Palash Kumar Mollick, Auteur ; Dakshinamoorthy Sathiyamoorthy, Auteur Année de publication : 2012 Article en page(s) : pp. 12117–12125 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Analysis pressure fluctuation Résumé : Spouted beds are widely used in many industrial applications for achieving good gas–solid contact/mixing especially for a bed of coarse/nonspherical particles. The stability of the spouted bed is important and critical for certain sensitive applications like coating, blending, catalytic conversion, etc. This paper presents the results of experimental investigations carried out using both two-dimensional and three-dimensional spouted beds to identify various transition velocities and condition to arrive at a stable spouted bed. Standard deviation and power spectral density (PSD) of pressure fluctuation were used to determine the stable operating fluidization/spouting velocity. Zirconia microspheres were used as the spouted bed material and argon, nitrogen, and methane were used as spouting gases. Standard deviation of pressure fluctuation was calculated at minimum spouting velocity and at a velocity corresponding to transition from stable spouting to unstable spouting condition. It is shown that standard deviation of pressure fluctuation and PSD varies with various spouting gases and seen to follow a trend with Archemedes number of a given gas–solid system. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300950p
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12117–12125[article] Assessment of stability of spouted bed using pressure fluctuation analysis [texte imprimé] / Palash Kumar Mollick, Auteur ; Dakshinamoorthy Sathiyamoorthy, Auteur . - 2012 . - pp. 12117–12125.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12117–12125
Mots-clés : Analysis pressure fluctuation Résumé : Spouted beds are widely used in many industrial applications for achieving good gas–solid contact/mixing especially for a bed of coarse/nonspherical particles. The stability of the spouted bed is important and critical for certain sensitive applications like coating, blending, catalytic conversion, etc. This paper presents the results of experimental investigations carried out using both two-dimensional and three-dimensional spouted beds to identify various transition velocities and condition to arrive at a stable spouted bed. Standard deviation and power spectral density (PSD) of pressure fluctuation were used to determine the stable operating fluidization/spouting velocity. Zirconia microspheres were used as the spouted bed material and argon, nitrogen, and methane were used as spouting gases. Standard deviation of pressure fluctuation was calculated at minimum spouting velocity and at a velocity corresponding to transition from stable spouting to unstable spouting condition. It is shown that standard deviation of pressure fluctuation and PSD varies with various spouting gases and seen to follow a trend with Archemedes number of a given gas–solid system. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300950p Exemplaires
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Titre : Precipitation of piperazine in aqueous piperazine solutions with and without CO2 loadings Type de document : texte imprimé Auteurs : Xiaoguang Ma, Auteur ; Inna Kim, Auteur ; Ralf Beck, Auteur Année de publication : 2012 Article en page(s) : pp. 12126–12134 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Piperazine Crystallization Résumé : The crystallization of piperazine in water as well as in systems loaded with CO2 has been studied for piperazine concentrations of 30–70 wt %, representing conditions relevant for CO2 capture. The use of a LabMax reactor system equipped with probes for in situ focused beam reflectance measurement (FBRM) and particle vision measurement (PVM) made it possible to determine solid–liquid transitions, crystal habit, and chord length distributions in these highly concentrated systems without disturbing the solid–liquid–gas equilibrium during crystallization. As shown by powder X-ray diffraction analysis, three phases including piperazine hemihydrate, piperazine hexahydrate, and anhydrous crystals were precipitated from the aqueous piperazine solutions at different concentrations and temperatures, as also supported by findings from FBRM and PVM. It was found that the metastable zone widths of the piperazine–H2O system were substantial even at the lower cooling rates, which could allow for a higher tolerance with respect to cooling prior to a new carbon dioxide absorption cycle. However, the eutectic composition exhibits a smaller metastable zone width than the other concentrations, which is believed to be caused by the precursor needle-shaped crystals, assisting the precipitation of the final product. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301101q
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12126–12134[article] Precipitation of piperazine in aqueous piperazine solutions with and without CO2 loadings [texte imprimé] / Xiaoguang Ma, Auteur ; Inna Kim, Auteur ; Ralf Beck, Auteur . - 2012 . - pp. 12126–12134.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12126–12134
Mots-clés : Piperazine Crystallization Résumé : The crystallization of piperazine in water as well as in systems loaded with CO2 has been studied for piperazine concentrations of 30–70 wt %, representing conditions relevant for CO2 capture. The use of a LabMax reactor system equipped with probes for in situ focused beam reflectance measurement (FBRM) and particle vision measurement (PVM) made it possible to determine solid–liquid transitions, crystal habit, and chord length distributions in these highly concentrated systems without disturbing the solid–liquid–gas equilibrium during crystallization. As shown by powder X-ray diffraction analysis, three phases including piperazine hemihydrate, piperazine hexahydrate, and anhydrous crystals were precipitated from the aqueous piperazine solutions at different concentrations and temperatures, as also supported by findings from FBRM and PVM. It was found that the metastable zone widths of the piperazine–H2O system were substantial even at the lower cooling rates, which could allow for a higher tolerance with respect to cooling prior to a new carbon dioxide absorption cycle. However, the eutectic composition exhibits a smaller metastable zone width than the other concentrations, which is believed to be caused by the precursor needle-shaped crystals, assisting the precipitation of the final product. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301101q Exemplaires
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Titre : Extension of the UNIFAC model for ionic liquids Type de document : texte imprimé Auteurs : Zhigang Lei, Auteur ; Chengna Dai, Auteur ; Xing Liu, Auteur Année de publication : 2012 Article en page(s) : pp. 12135–12144 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Extension Ionic Liquids Résumé : The UNIFAC model has recently become very popular for ionic liquids (ILs) because of its applicability for prediction of thermodynamic properties. This work is a continuation of our studies on the extension of group parameters of the UNIFAC model to systems with ILs. The new IL groups for 33 main groups and 53 subgroups were added into the current UNIFAC parameter matrix. The parameters of group surface area and volume for ILs were obtained by the COSMO calculation, while the group binary interaction parameters, anm and amn, were obtained by means of correlating the activity coefficients of solutes at infinite dilution in ILs at different temperatures exhaustively collected from literature by the end of 2011. The predicted results of UNIFAC model are more accurate than those of the COSMO-RS model so that it can be used for identifying the general relationship between molecular structure of ILs and separation performance for the separation of liquid mixtures with ILs. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301159v
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12135–12144[article] Extension of the UNIFAC model for ionic liquids [texte imprimé] / Zhigang Lei, Auteur ; Chengna Dai, Auteur ; Xing Liu, Auteur . - 2012 . - pp. 12135–12144.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12135–12144
Mots-clés : Extension Ionic Liquids Résumé : The UNIFAC model has recently become very popular for ionic liquids (ILs) because of its applicability for prediction of thermodynamic properties. This work is a continuation of our studies on the extension of group parameters of the UNIFAC model to systems with ILs. The new IL groups for 33 main groups and 53 subgroups were added into the current UNIFAC parameter matrix. The parameters of group surface area and volume for ILs were obtained by the COSMO calculation, while the group binary interaction parameters, anm and amn, were obtained by means of correlating the activity coefficients of solutes at infinite dilution in ILs at different temperatures exhaustively collected from literature by the end of 2011. The predicted results of UNIFAC model are more accurate than those of the COSMO-RS model so that it can be used for identifying the general relationship between molecular structure of ILs and separation performance for the separation of liquid mixtures with ILs. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301159v Exemplaires
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Titre : Polyacrylates with high biomass contents for pressure - sensitive adhesives prepared via mini - emulsion polymerization Type de document : texte imprimé Auteurs : Gang Pu, Auteur ; Matthew R. Dubay, Auteur ; Jiguang Zhang, Auteur Année de publication : 2012 Article en page(s) : pp. 12145–12149 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Polyacrylates Biomass Résumé : n-Butyl acrylate and other acrylic monomers were copolymerized with an acrylated macromonomer to produce polymers for pressure-sensitive adhesive (PSA) applications. Macromonomers were generated through the ring-opening copolymerization of l-lactide and ε-caprolactone with 2-hydroxyethyl methacrylate (HEMA) at an average molar composition of 5:4:1, respectively. Conversion in the mini-emulsion polymerization was followed using Raman spectroscopy and was nearly complete within 2 h. Testing of these adhesive polymers indicates that performance properties meet or exceed those of commercial water-based acrylic PSAs. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301492v
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12145–12149[article] Polyacrylates with high biomass contents for pressure - sensitive adhesives prepared via mini - emulsion polymerization [texte imprimé] / Gang Pu, Auteur ; Matthew R. Dubay, Auteur ; Jiguang Zhang, Auteur . - 2012 . - pp. 12145–12149.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12145–12149
Mots-clés : Polyacrylates Biomass Résumé : n-Butyl acrylate and other acrylic monomers were copolymerized with an acrylated macromonomer to produce polymers for pressure-sensitive adhesive (PSA) applications. Macromonomers were generated through the ring-opening copolymerization of l-lactide and ε-caprolactone with 2-hydroxyethyl methacrylate (HEMA) at an average molar composition of 5:4:1, respectively. Conversion in the mini-emulsion polymerization was followed using Raman spectroscopy and was nearly complete within 2 h. Testing of these adhesive polymers indicates that performance properties meet or exceed those of commercial water-based acrylic PSAs. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301492v Exemplaires
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Titre : Liquid organic hydrogen carriers : An upcoming alternative to conventional technologies. thermochemical studies. Type de document : texte imprimé Auteurs : Sergey P. Verevkin, Auteur ; Vladimir N. Emel'yanenko, Auteur ; Andreas Heintz, Auteur Année de publication : 2012 Article en page(s) : pp. 12150–12153 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydrogen Thermochemical Résumé : A system based on the catalytic hydrogenation/dehydrogenation reactions of N-ethylcarbazole is one of the most promising as the new class of the liquid organic hydrogen carrier (LOHC) compounds. Enthalpy of formation of the liquid dodecahydro-N-ethylcarbazole (fully hydrogenated N-ethylcarbazole) was measured using combustion calorimetry. Vaporization enthalpy for this compound was derived from vapor pressure–temperature dependence measured by transpiration. The enthalpy of formation of the gaseous dodecahydro-N-ethylcarbazole was derived and validated with the high-level quantum chemical calculation. Vapor pressures of the liquid N-ethylcarbazole (0.0008 bar) and dodecahydro-N-ethylcarbazole (0.01 bar) at a practical and relevant temperature (400 K) were assessed from the new experimental data. It has turned out that these vapor pressures were low enough to fulfill the basic requirement for an LOHC. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301898m
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12150–12153[article] Liquid organic hydrogen carriers : An upcoming alternative to conventional technologies. thermochemical studies. [texte imprimé] / Sergey P. Verevkin, Auteur ; Vladimir N. Emel'yanenko, Auteur ; Andreas Heintz, Auteur . - 2012 . - pp. 12150–12153.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12150–12153
Mots-clés : Hydrogen Thermochemical Résumé : A system based on the catalytic hydrogenation/dehydrogenation reactions of N-ethylcarbazole is one of the most promising as the new class of the liquid organic hydrogen carrier (LOHC) compounds. Enthalpy of formation of the liquid dodecahydro-N-ethylcarbazole (fully hydrogenated N-ethylcarbazole) was measured using combustion calorimetry. Vaporization enthalpy for this compound was derived from vapor pressure–temperature dependence measured by transpiration. The enthalpy of formation of the gaseous dodecahydro-N-ethylcarbazole was derived and validated with the high-level quantum chemical calculation. Vapor pressures of the liquid N-ethylcarbazole (0.0008 bar) and dodecahydro-N-ethylcarbazole (0.01 bar) at a practical and relevant temperature (400 K) were assessed from the new experimental data. It has turned out that these vapor pressures were low enough to fulfill the basic requirement for an LOHC. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301898m Exemplaires
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