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Vol. 51 N° 16 - Avril 2012 [texte imprimé] . - 2012 . - p. 5635-5838 : ill. ; 28 cm. Chemical engineering Langues : Anglais (eng)
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Ajouter le résultat dans votre panierOn the influence of surfactant incorporation during electroless nickel plating / Nkem Nwosu in Industrial & engineering chemistry research, Vol. 51 N° 16 (Avril 2012)
Titre : On the influence of surfactant incorporation during electroless nickel plating Type de document : texte imprimé Auteurs : Nkem Nwosu, Auteur ; Alan Davidson, Auteur ; Colin Hindle, Auteur Année de publication : 2012 Article en page(s) : pp. 5635–5644 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Surfactant Résumé : The effects of surfactants on the dynamics and characteristics of plain and composite electroless nickel plating (ENP) are highlighted and discussed herein. An outline of the rudiments of surfactants and some underlying selection criteria is presented at the outset, before emphasis is laid on the salient benefits of introducing such external agents during the plating process. Evidence suggests that their influence on key coating characteristics such as the rate of deposition, structure, corrosion resistance, and the degree of second-phase particle incorporation into the nickel matrix is significant, and depending on the nature and concentration of surfactant employed, can be of immense value to the system. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25834475
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5635–5644[article] On the influence of surfactant incorporation during electroless nickel plating [texte imprimé] / Nkem Nwosu, Auteur ; Alan Davidson, Auteur ; Colin Hindle, Auteur . - 2012 . - pp. 5635–5644.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5635–5644
Mots-clés : Surfactant Résumé : The effects of surfactants on the dynamics and characteristics of plain and composite electroless nickel plating (ENP) are highlighted and discussed herein. An outline of the rudiments of surfactants and some underlying selection criteria is presented at the outset, before emphasis is laid on the salient benefits of introducing such external agents during the plating process. Evidence suggests that their influence on key coating characteristics such as the rate of deposition, structure, corrosion resistance, and the degree of second-phase particle incorporation into the nickel matrix is significant, and depending on the nature and concentration of surfactant employed, can be of immense value to the system. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25834475 Exemplaires
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Titre : Identification and quantitation of volatile organic compounds from oxidation of linseed oil Type de document : texte imprimé Auteurs : Juita, Auteur ; Bogdan Z. Dlugogorski, Auteur ; Eric M. Kennedy, Auteur Année de publication : 2012 Article en page(s) : pp. 5645-5652 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Oxidation Volatile organic compound Résumé : Solid phase microextraction (SPME) combined with gas chromatography-mass spectrometry (GC-MS) served to identify and quantitate the volatile organic compounds (VOCs) formed in the degradative oxidation of linseed oil. SPME involved experiments under nitrogen and oxygen atmosphere, two oil types (raw and boiled), and two different methods of sampling the head space to differentiate between the oxidation products and the oil impurities. Further experiments entailed the oxidation of neat linoleic and linolenic acids to assist with the development of a detailed reaction mechanism. The majority of the detected product species originated from the oxidation of linolenic compounds, which dominate the composition of linseed oil, while 2-propenal, pentanal, hexanal, 2,4-decadienal, and hexanoic acid, among others, were released from linoleic compounds. The concentration of hexanal (7-26), 2-pentenal (25-39), 1-penten-3-ol (3.1-4.8), trans,trans-2,4-heptadienal (33-50), trans,trans-2,4-decadienal (0.7-0.8), 3,5-octadien-2-one (2.5-6.2; relative area), ethanoic acid (137-195), and hexanoic acid (18-29) increased with the progress of oxidation; the numbers in the parentheses indicate initial and final concentration (ppm) of the species in the oil in 6 h experiments. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25834476
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5645-5652[article] Identification and quantitation of volatile organic compounds from oxidation of linseed oil [texte imprimé] / Juita, Auteur ; Bogdan Z. Dlugogorski, Auteur ; Eric M. Kennedy, Auteur . - 2012 . - pp. 5645-5652.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5645-5652
Mots-clés : Oxidation Volatile organic compound Résumé : Solid phase microextraction (SPME) combined with gas chromatography-mass spectrometry (GC-MS) served to identify and quantitate the volatile organic compounds (VOCs) formed in the degradative oxidation of linseed oil. SPME involved experiments under nitrogen and oxygen atmosphere, two oil types (raw and boiled), and two different methods of sampling the head space to differentiate between the oxidation products and the oil impurities. Further experiments entailed the oxidation of neat linoleic and linolenic acids to assist with the development of a detailed reaction mechanism. The majority of the detected product species originated from the oxidation of linolenic compounds, which dominate the composition of linseed oil, while 2-propenal, pentanal, hexanal, 2,4-decadienal, and hexanoic acid, among others, were released from linoleic compounds. The concentration of hexanal (7-26), 2-pentenal (25-39), 1-penten-3-ol (3.1-4.8), trans,trans-2,4-heptadienal (33-50), trans,trans-2,4-decadienal (0.7-0.8), 3,5-octadien-2-one (2.5-6.2; relative area), ethanoic acid (137-195), and hexanoic acid (18-29) increased with the progress of oxidation; the numbers in the parentheses indicate initial and final concentration (ppm) of the species in the oil in 6 h experiments. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25834476 Exemplaires
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Titre : Mechanism of formation of volatile organic compounds from oxidation of linseed oil Type de document : texte imprimé Auteurs : Juita, Auteur ; Bogdan Z. Dlugogorski, Auteur ; Eric M. Kennedy, Auteur Année de publication : 2012 Article en page(s) : pp. 5653-5661 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Oxidation Volatile organic compound Résumé : The pathways of volatile organic compound (VOC) formation have been investigated through a computational study, employing the Gaussian 03 suite of programs. We optimized geometries and zero-point vibrational energies (ZPVEs) at the B3LYP/6-31G(d) level of theory and improved electronic energies by conducting single-point energy calculations using the large 6-311++G(3df,3pd) basis set. To describe the predominant mechanism of the linseed oil oxidation, the following sequence is proposed: hydrogen abstraction of unsaturated fatty compounds as the initiation reaction followed by the reaction of allylic-type radicals with molecular oxygen to form peroxyl radicals and finally intramolecular rearrangement through four- and five-membered rings. Quantum calculations identified low-energy pathways following cyclization resulting in the formation of major products observed, especially aldehydes and ketones. The overall energy changes taking place through the four- and five-membered rings were found to be 78 and 93 kJ mol-1 exothermic, respectively. Metal catalysts decompose hydroperoxides based on the Fenton-like mechanism into alkoxyl and peroxyl radicals. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25834477
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5653-5661[article] Mechanism of formation of volatile organic compounds from oxidation of linseed oil [texte imprimé] / Juita, Auteur ; Bogdan Z. Dlugogorski, Auteur ; Eric M. Kennedy, Auteur . - 2012 . - pp. 5653-5661.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5653-5661
Mots-clés : Oxidation Volatile organic compound Résumé : The pathways of volatile organic compound (VOC) formation have been investigated through a computational study, employing the Gaussian 03 suite of programs. We optimized geometries and zero-point vibrational energies (ZPVEs) at the B3LYP/6-31G(d) level of theory and improved electronic energies by conducting single-point energy calculations using the large 6-311++G(3df,3pd) basis set. To describe the predominant mechanism of the linseed oil oxidation, the following sequence is proposed: hydrogen abstraction of unsaturated fatty compounds as the initiation reaction followed by the reaction of allylic-type radicals with molecular oxygen to form peroxyl radicals and finally intramolecular rearrangement through four- and five-membered rings. Quantum calculations identified low-energy pathways following cyclization resulting in the formation of major products observed, especially aldehydes and ketones. The overall energy changes taking place through the four- and five-membered rings were found to be 78 and 93 kJ mol-1 exothermic, respectively. Metal catalysts decompose hydroperoxides based on the Fenton-like mechanism into alkoxyl and peroxyl radicals. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25834477 Exemplaires
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Titre : Effective enhancement of the degradation of oxalic acid by catalytic ozonation with TiO2 by exposure of {001} facets and surface fluorination Type de document : texte imprimé Auteurs : Zhiqiao He, Auteur ; Qiaolan Cai, Auteur ; Fangyue Hong, Auteur Année de publication : 2012 Article en page(s) : pp. 5662–5668 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Oxidation Oxalic acid Catalytic ozonation Résumé : Heterogeneous catalytic ozonation is a promising advanced oxidation technology for water treatment. In the present work, the surface fluorination of TiO2 catalysts with a high percentage of exposed {001} facets (F-TiO2) were synthesized through a hydrothermal method using tetrabutyl titanate as the precursor and HF as the shape controlling agent. The structural properties of the catalysts were characterized by X-ray diffraction, the Brunauer–Emmett–Teller method, field-emission scanning electron microscopy, and X-ray photoelectron spectroscopy. The sheetlike TiO2 is pure anatase, with 75% of highly reactive {001} facets. The surface fluoride of the F-TiO2 nanosheets can be removed by washing with dilute NaOH solution (abbreviated here as OH-TiO2), resulting in a decrease of Ti3+ content and an increase of the specific surface area. The catalytic activity of the samples was evaluated by degradation of oxalic acid in aqueous solution in the presence of ozone. It was found that F-TiO2 facilitated the catalytic ozonation process by comparison with OH-TiO2 and pure TiO2 nanoparticles prepared in pure water. We conclude that the high surface energies of {001} facets and the increased concentration of oxygen vacancies contributed to the enhancement of the ozonation activity of fluorinated TiO2 with dominant {001} facets. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202357d
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5662–5668[article] Effective enhancement of the degradation of oxalic acid by catalytic ozonation with TiO2 by exposure of {001} facets and surface fluorination [texte imprimé] / Zhiqiao He, Auteur ; Qiaolan Cai, Auteur ; Fangyue Hong, Auteur . - 2012 . - pp. 5662–5668.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5662–5668
Mots-clés : Oxidation Oxalic acid Catalytic ozonation Résumé : Heterogeneous catalytic ozonation is a promising advanced oxidation technology for water treatment. In the present work, the surface fluorination of TiO2 catalysts with a high percentage of exposed {001} facets (F-TiO2) were synthesized through a hydrothermal method using tetrabutyl titanate as the precursor and HF as the shape controlling agent. The structural properties of the catalysts were characterized by X-ray diffraction, the Brunauer–Emmett–Teller method, field-emission scanning electron microscopy, and X-ray photoelectron spectroscopy. The sheetlike TiO2 is pure anatase, with 75% of highly reactive {001} facets. The surface fluoride of the F-TiO2 nanosheets can be removed by washing with dilute NaOH solution (abbreviated here as OH-TiO2), resulting in a decrease of Ti3+ content and an increase of the specific surface area. The catalytic activity of the samples was evaluated by degradation of oxalic acid in aqueous solution in the presence of ozone. It was found that F-TiO2 facilitated the catalytic ozonation process by comparison with OH-TiO2 and pure TiO2 nanoparticles prepared in pure water. We conclude that the high surface energies of {001} facets and the increased concentration of oxygen vacancies contributed to the enhancement of the ozonation activity of fluorinated TiO2 with dominant {001} facets. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202357d Exemplaires
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Titre : Reaction between tetrameric acids and Ca2+ in oil / water system Type de document : texte imprimé Auteurs : Sébastien Simon, Auteur ; Christian Reisen, Auteur ; Anita Bersas, Auteur Année de publication : 2012 Article en page(s) : pp. 5669-5676 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Tetrameric acids Résumé : C80 tetra-acid (also known as ARN) is a molecule present in crude oil that can precipitate during oil production in basic medium and in presence of calcium ions to form deposits. The formation of such deposits is detrimental in production because they can plug oil production facilities and may lead to costly production shutdowns due to deferment and clean up operations. To better understand this reaction, the solubility of a model molecule mimicking the properties of C80 tetra-acid (named BP-10) have been measured in an oil/water system, using chloroform as oil in presence of calcium to establish quantitative relationships between solubility and pH, calcium concentration, temperature, and other parameters. It has been determined that the maximum BP-10 concentration in oil phase (solubility limit) follows the following relationship: [BP-10]o = A X 10-4pH, with the fitting parameter A X [Ca2+]2 = 2.6 × 1018 mol-1·L+1. This relationship is valid at [Ca2+] ≥ 10 mM, with a slight overestimation of the solubility at lower calcium concentration from temperatures varying from 5 to 50 °C. This relationship holds at any ionic strength (up to 600 mM of NaCl) and total BP-10 concentration (up to 200 μM) in the system. In presence of Mg2+, the relation is still valid with a different prefactor. For all the studied systems, the concentration of BP-10 in water was very low, lower than 2 μM. The solubilities of C80 tetra-acid in oil phase with BP-10 one have been compared. Both molecules have a similar pH range for precipitation, but C80 tetra-acid has a different relationship between its concentration in oil phase and pH. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3000634
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5669-5676[article] Reaction between tetrameric acids and Ca2+ in oil / water system [texte imprimé] / Sébastien Simon, Auteur ; Christian Reisen, Auteur ; Anita Bersas, Auteur . - 2012 . - pp. 5669-5676.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5669-5676
Mots-clés : Tetrameric acids Résumé : C80 tetra-acid (also known as ARN) is a molecule present in crude oil that can precipitate during oil production in basic medium and in presence of calcium ions to form deposits. The formation of such deposits is detrimental in production because they can plug oil production facilities and may lead to costly production shutdowns due to deferment and clean up operations. To better understand this reaction, the solubility of a model molecule mimicking the properties of C80 tetra-acid (named BP-10) have been measured in an oil/water system, using chloroform as oil in presence of calcium to establish quantitative relationships between solubility and pH, calcium concentration, temperature, and other parameters. It has been determined that the maximum BP-10 concentration in oil phase (solubility limit) follows the following relationship: [BP-10]o = A X 10-4pH, with the fitting parameter A X [Ca2+]2 = 2.6 × 1018 mol-1·L+1. This relationship is valid at [Ca2+] ≥ 10 mM, with a slight overestimation of the solubility at lower calcium concentration from temperatures varying from 5 to 50 °C. This relationship holds at any ionic strength (up to 600 mM of NaCl) and total BP-10 concentration (up to 200 μM) in the system. In presence of Mg2+, the relation is still valid with a different prefactor. For all the studied systems, the concentration of BP-10 in water was very low, lower than 2 μM. The solubilities of C80 tetra-acid in oil phase with BP-10 one have been compared. Both molecules have a similar pH range for precipitation, but C80 tetra-acid has a different relationship between its concentration in oil phase and pH. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3000634 Exemplaires
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Titre : Synthesis and characterization of a few amino - functionalized copolymeric resins and their environmental applications Type de document : texte imprimé Auteurs : Muniyappan Rajiv Gandhi, Auteur ; Natrayasamy Viswanathan, Auteur ; Sankaran Meenakshi, Auteur Année de publication : 2012 Article en page(s) : pp. 5677–5684 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Polymeric resins Adsorption Résumé : The synthetic copolymeric resins acrylonitrile/divinylbenzene/vinylbenzyl chloride (AN/DVB/VBC), styrene/divinylbenzene/vinylbenzyl chloride (ST/DVB/VBC), and vinylbenzyl chloride/divinylbenzene (VBC/DVB) have been prepared by suspension polymerization. These polymeric matrixes were aminated with ethylenediamine (ED) and then protonated to increase their selectivity toward Cr(VI). The experiments were carried out in batch mode to optimize various influencing parameters, namely, contact time, pH, other interfering co-ions, and temperature. The chromium removal capacity (CRC) of AN/DVB/VBC–ED resin was found to be higher than those of the other prepared copolymers. The mechanism of chromium removal was governed by electrostatic-adsorption-coupled reduction and complexation. The polymeric resins and chromium-sorbed resins were characterized by FTIR, SEM–EDAX, BET, elemental analysis, and EPR studies. The adsorption data were fitted with Freundlich and Langmuir isotherms. The calculated values of thermodynamic parameters indicated the nature of chromium sorption. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3000503
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5677–5684[article] Synthesis and characterization of a few amino - functionalized copolymeric resins and their environmental applications [texte imprimé] / Muniyappan Rajiv Gandhi, Auteur ; Natrayasamy Viswanathan, Auteur ; Sankaran Meenakshi, Auteur . - 2012 . - pp. 5677–5684.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5677–5684
Mots-clés : Polymeric resins Adsorption Résumé : The synthetic copolymeric resins acrylonitrile/divinylbenzene/vinylbenzyl chloride (AN/DVB/VBC), styrene/divinylbenzene/vinylbenzyl chloride (ST/DVB/VBC), and vinylbenzyl chloride/divinylbenzene (VBC/DVB) have been prepared by suspension polymerization. These polymeric matrixes were aminated with ethylenediamine (ED) and then protonated to increase their selectivity toward Cr(VI). The experiments were carried out in batch mode to optimize various influencing parameters, namely, contact time, pH, other interfering co-ions, and temperature. The chromium removal capacity (CRC) of AN/DVB/VBC–ED resin was found to be higher than those of the other prepared copolymers. The mechanism of chromium removal was governed by electrostatic-adsorption-coupled reduction and complexation. The polymeric resins and chromium-sorbed resins were characterized by FTIR, SEM–EDAX, BET, elemental analysis, and EPR studies. The adsorption data were fitted with Freundlich and Langmuir isotherms. The calculated values of thermodynamic parameters indicated the nature of chromium sorption. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3000503 Exemplaires
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Titre : Catalytic gasification of poultry manure and eucalyptus wood mixture 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. 5685-5690 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Supercritical state Wood Poultry manure Gasification Catalytic reaction Résumé : The effect of wood addition on supercritical water gasification (SCWG) of poultry manure is investigated for broiler-derived wastes consisting of manure and the bedding material such as wood sawdust. SCWG of poultry manure (0.5 wt %) with Eucalyptus wood (0-0.3 wt %) is conducted in a continuous flow system for the temperature range of 550-650 °C and a pressure of 25 MPa. The organic matter in the poultry manure is mainly converted into fuel gases such as H2, CO2, and CH4. During SCWG of poultry manure and wood, not only decomposition of both but also reactions between their decomposition products occur. Wood biomass (cellulose and hemicellulose) are easily decomposed in SCW compared to poultry manure. However, at higher loading of wood in the mixture, the existence of inhibiting compounds in the wood decelerates the gas producing pathways in the overall reactions. The usage of activated carbon in the feedstock mixture improves the gasification efficiency. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25834481
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5685-5690[article] Catalytic gasification of poultry manure and eucalyptus wood mixture in supercritical water [texte imprimé] / Tau Len-Kelly Yong, Auteur ; Yukihiko Matsumura, Auteur . - 2012 . - pp. 5685-5690.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5685-5690
Mots-clés : Supercritical state Wood Poultry manure Gasification Catalytic reaction Résumé : The effect of wood addition on supercritical water gasification (SCWG) of poultry manure is investigated for broiler-derived wastes consisting of manure and the bedding material such as wood sawdust. SCWG of poultry manure (0.5 wt %) with Eucalyptus wood (0-0.3 wt %) is conducted in a continuous flow system for the temperature range of 550-650 °C and a pressure of 25 MPa. The organic matter in the poultry manure is mainly converted into fuel gases such as H2, CO2, and CH4. During SCWG of poultry manure and wood, not only decomposition of both but also reactions between their decomposition products occur. Wood biomass (cellulose and hemicellulose) are easily decomposed in SCW compared to poultry manure. However, at higher loading of wood in the mixture, the existence of inhibiting compounds in the wood decelerates the gas producing pathways in the overall reactions. The usage of activated carbon in the feedstock mixture improves the gasification efficiency. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25834481 Exemplaires
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Titre : Catalytic performance of silica - supported silver nanoparticles for liquid - phase oxidation of ethylbenzene Type de document : texte imprimé Auteurs : Raji Vadakkekara, Auteur ; Mousumi Chakraborty, Auteur ; Parimal A. Parikh, Auteur Année de publication : 2012 Article en page(s) : pp. 5691-5698 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Oxidation Liquid phase Nanoparticle Catalytic reaction Résumé : In this study silver nanoparticles were prepared by chemical reduction method using silver nitrate as metal precursor, starch as protecting agent, and sodium borohydride (NaBH4) as a reducing agent. Formation of silver nanoparticles was monitored using UV-vis absorption spectroscopy and dynamic light scattering (DLS). They were supported on silica by dispersing silica powder in the suspension of destabilized silver nanoparticles. Samples containing different proportions of silver were thus prepared. This method is at variance from the conventionally employed method, i.e., impregnation of silver salt from its solution on support. Ag/SiO2 samples were characterized by UV-vis absorption spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), inductive coupled plasma optical emission spectroscopy (ICP-OES), and N, adsorption-desorption. Superior catalytic performance of the catalyst prepared by the present method could be observed in a test reaction of ethylbenzene oxidation affording high selectivity to acetophenone as compared to the catalyst prepared by the conventional reported methods. The 5 wt % Ag/SiO2 catalyst was found not much susceptible to sintering as could be inferred from the comparable performance of the regenerated and fresh catalysts. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25834482
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5691-5698[article] Catalytic performance of silica - supported silver nanoparticles for liquid - phase oxidation of ethylbenzene [texte imprimé] / Raji Vadakkekara, Auteur ; Mousumi Chakraborty, Auteur ; Parimal A. Parikh, Auteur . - 2012 . - pp. 5691-5698.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5691-5698
Mots-clés : Oxidation Liquid phase Nanoparticle Catalytic reaction Résumé : In this study silver nanoparticles were prepared by chemical reduction method using silver nitrate as metal precursor, starch as protecting agent, and sodium borohydride (NaBH4) as a reducing agent. Formation of silver nanoparticles was monitored using UV-vis absorption spectroscopy and dynamic light scattering (DLS). They were supported on silica by dispersing silica powder in the suspension of destabilized silver nanoparticles. Samples containing different proportions of silver were thus prepared. This method is at variance from the conventionally employed method, i.e., impregnation of silver salt from its solution on support. Ag/SiO2 samples were characterized by UV-vis absorption spectroscopy, transmission electron microscopy (TEM), scanning electron microscopy (SEM), X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), inductive coupled plasma optical emission spectroscopy (ICP-OES), and N, adsorption-desorption. Superior catalytic performance of the catalyst prepared by the present method could be observed in a test reaction of ethylbenzene oxidation affording high selectivity to acetophenone as compared to the catalyst prepared by the conventional reported methods. The 5 wt % Ag/SiO2 catalyst was found not much susceptible to sintering as could be inferred from the comparable performance of the regenerated and fresh catalysts. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25834482 Exemplaires
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Titre : Recovery of terephthalic acid and ethylene glycol from poly(ethylene terephthalate) under hydrothermal conditions of aqueous trimethylamine solution Type de document : texte imprimé Auteurs : Natsumi Wakabayashi, Auteur ; Tomoharu Kojima, Auteur ; Toshitaka Funazukuri, Auteur Année de publication : 2012 Article en page(s) : pp. 5699-5704 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydrothermal condition Résumé : Poly(ethylene terephthalate) pellets were subjected to various amine solutions under hydrothermal conditions in a semibatch reactor. Methylamine, ethylamine, dimethylamine, trimethylamine, ammonia, and sodium hydroxide were examined at 473 K and 10 MPa at concentrations of 0.6 mol/kg. The effects of the amine species on reaction rates and monomer yields were compared. For all solvents examined in the present study, the reactions were expressed by a surface reaction model, i.e., the 2/3rd-order reaction kinetics with respect to unreacted polymer mass. The reaction rates with the four amines were not very different and were similar to that with NaOH at the same concentration; but, they were faster than the rate with ammonia. When the reaction was conducted with trimethylamine, the yields of monomers and total yields of terephthalic acid and ethylene glycol were very close to the theoretical values. However, those with dimethylamine, ethylamine, and methylamine were slightly lower with intermediate products found in the product solutions. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25834483
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5699-5704[article] Recovery of terephthalic acid and ethylene glycol from poly(ethylene terephthalate) under hydrothermal conditions of aqueous trimethylamine solution [texte imprimé] / Natsumi Wakabayashi, Auteur ; Tomoharu Kojima, Auteur ; Toshitaka Funazukuri, Auteur . - 2012 . - pp. 5699-5704.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5699-5704
Mots-clés : Hydrothermal condition Résumé : Poly(ethylene terephthalate) pellets were subjected to various amine solutions under hydrothermal conditions in a semibatch reactor. Methylamine, ethylamine, dimethylamine, trimethylamine, ammonia, and sodium hydroxide were examined at 473 K and 10 MPa at concentrations of 0.6 mol/kg. The effects of the amine species on reaction rates and monomer yields were compared. For all solvents examined in the present study, the reactions were expressed by a surface reaction model, i.e., the 2/3rd-order reaction kinetics with respect to unreacted polymer mass. The reaction rates with the four amines were not very different and were similar to that with NaOH at the same concentration; but, they were faster than the rate with ammonia. When the reaction was conducted with trimethylamine, the yields of monomers and total yields of terephthalic acid and ethylene glycol were very close to the theoretical values. However, those with dimethylamine, ethylamine, and methylamine were slightly lower with intermediate products found in the product solutions. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25834483 Exemplaires
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Titre : Improved modeling of bubble column reactors by considering the bubble size distribution Type de document : texte imprimé Auteurs : Mohammad Ramezani, Auteur ; Navid Mostoufi, Auteur ; Mohammad Reza Mehrnia, Auteur Année de publication : 2012 Article en page(s) : pp. 5705-5714 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Particle size distribution Bubble Reactor column Modeling Résumé : Bioconversion of glucose to gluconic acid with glucose oxidase as enzyme was considered to occur in a bubble column reactor at 40 °C, atmospheric pressure, and pH 5.5 while oxygen gas velocity was varied in the homogeneous and transition regime in the range of 0.0014-0.0112 m s-1. It was found that the superficial gas velocity has a positive effect on gas holdup, mean bubble size, and volumetric mass transfer coefficient, while the glucose concentration has a negative influence on these hydrodynamic parameters. The modeling of bubble column by considering the complete bubble size distribution in the governing equations was carried out in this work. The model was also solved by considering the single and double sizes of bubbles instead of complete bubble size distribution. It was shown that the results of the model, considering the complete bubble size distribution, is in a good agreement with the experimental data, while the considered single and double bubble sizes cannot predict the experimental data of oxygen concentration in the reactor properly. It was also found that the superficial gas velocity has a positive influence on oxygen concentration while glucose concentration has negative influence at low superficial gas velocity and positive influence at high gas velocity. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25834484
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5705-5714[article] Improved modeling of bubble column reactors by considering the bubble size distribution [texte imprimé] / Mohammad Ramezani, Auteur ; Navid Mostoufi, Auteur ; Mohammad Reza Mehrnia, Auteur . - 2012 . - pp. 5705-5714.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5705-5714
Mots-clés : Particle size distribution Bubble Reactor column Modeling Résumé : Bioconversion of glucose to gluconic acid with glucose oxidase as enzyme was considered to occur in a bubble column reactor at 40 °C, atmospheric pressure, and pH 5.5 while oxygen gas velocity was varied in the homogeneous and transition regime in the range of 0.0014-0.0112 m s-1. It was found that the superficial gas velocity has a positive effect on gas holdup, mean bubble size, and volumetric mass transfer coefficient, while the glucose concentration has a negative influence on these hydrodynamic parameters. The modeling of bubble column by considering the complete bubble size distribution in the governing equations was carried out in this work. The model was also solved by considering the single and double sizes of bubbles instead of complete bubble size distribution. It was shown that the results of the model, considering the complete bubble size distribution, is in a good agreement with the experimental data, while the considered single and double bubble sizes cannot predict the experimental data of oxygen concentration in the reactor properly. It was also found that the superficial gas velocity has a positive influence on oxygen concentration while glucose concentration has negative influence at low superficial gas velocity and positive influence at high gas velocity. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25834484 Exemplaires
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Titre : Energy efficiencies in a photo - CREC - air reactor : Conversion of model organic pollutants in air Type de document : texte imprimé Auteurs : Juan Manuel Garcia-Hernandez, Auteur ; Benito Serrano-Rosales, Auteur ; Hugo De Lasa, Auteur Année de publication : 2012 Article en page(s) : pp. 5715-5727 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Pollutant Modeling Reactor Energetic efficiency Résumé : The energy efficiency of the photocatalytic conversion of gas-phase organic pollutants was studied using a redesigned and scaled-up photo-CREC-air reactor. This photocatalytic unit has the unique feature of allowing an accurate analysis of the irradiation field by establishing macroscopic balances and in situ measurements. The photo-CREC-air reactor operates in batch mode with the photocatalyst supported by a stainless steel mesh being irradiated by eight UV lamps. Kinetic modeling was performed, and quantum yields (QYs) and photochemical thermodynamic efficiency factors (PTEFs) were calculated using data for acetone and acetaldehyde photocatalytic degradation in ambient air utilizing a Degussa P25 (Aeroxide 25) photocatalyst. It was found that the photo-CREC-air reactor is suitable for the determination of kinetic and adsorption parameters, given a design with excellent irradiation usage and fluid-catalyst contact. In this respect, quantum yields for both acetone and acetaldehyde exceed the value of 1 (equivalent to 100%), with PTEFs in both cases remaining below the level of 1, as required by thermodynamics. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25834485
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5715-5727[article] Energy efficiencies in a photo - CREC - air reactor : Conversion of model organic pollutants in air [texte imprimé] / Juan Manuel Garcia-Hernandez, Auteur ; Benito Serrano-Rosales, Auteur ; Hugo De Lasa, Auteur . - 2012 . - pp. 5715-5727.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5715-5727
Mots-clés : Pollutant Modeling Reactor Energetic efficiency Résumé : The energy efficiency of the photocatalytic conversion of gas-phase organic pollutants was studied using a redesigned and scaled-up photo-CREC-air reactor. This photocatalytic unit has the unique feature of allowing an accurate analysis of the irradiation field by establishing macroscopic balances and in situ measurements. The photo-CREC-air reactor operates in batch mode with the photocatalyst supported by a stainless steel mesh being irradiated by eight UV lamps. Kinetic modeling was performed, and quantum yields (QYs) and photochemical thermodynamic efficiency factors (PTEFs) were calculated using data for acetone and acetaldehyde photocatalytic degradation in ambient air utilizing a Degussa P25 (Aeroxide 25) photocatalyst. It was found that the photo-CREC-air reactor is suitable for the determination of kinetic and adsorption parameters, given a design with excellent irradiation usage and fluid-catalyst contact. In this respect, quantum yields for both acetone and acetaldehyde exceed the value of 1 (equivalent to 100%), with PTEFs in both cases remaining below the level of 1, as required by thermodynamics. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25834485 Exemplaires
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Titre : Kinetics of the oxidation of tetracycline hydrate by copper(II) complexed with bipyridyl in alkaline medium using chloro - complex of palladium (II) as homogeneous catalyst Type de document : texte imprimé Auteurs : Ashok Kumar Singh, Auteur ; Manjula Singh, Auteur ; Shahla Rahmani, Auteur Année de publication : 2012 Article en page(s) : pp. 5728-573 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Homogeneous catalysis Oxidation Kinetics Résumé : The present paper deals with the kinetics and mechanism of Pd(II)-catalyzed oxidation of tetracycline hydrate by Cu(Bip)22+ in alkaline medium. First-order kinetics with respect to [tetracycline hydrate] and fractional positive order kinetics in [Cu(II)] and [Pd(II)] was observed. Nil effect of [OH-] and [bipyridyl] on the rate of oxidation was observed. Almost no effect of ionic strength as well as dielectric constant of the medium on the rate of oxidation was observed. The reaction was studied at four different temperatures and observed values of rate constants were utilized to calculate various activation parameters specially the entropy of activation (ΔS#). With the help of the observed kinetic orders with respect to the reactants involved in the reaction, spechophotometric evidence collected for the formation of reactive complexes and the positive entropy of activation, a most probable reaction mechanism for Pd(II)-catalyzed oxidation of tetracycline hydrate by Cu(Bip)22+ in alkaline medium has been proposed. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25834486
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5728-573[article] Kinetics of the oxidation of tetracycline hydrate by copper(II) complexed with bipyridyl in alkaline medium using chloro - complex of palladium (II) as homogeneous catalyst [texte imprimé] / Ashok Kumar Singh, Auteur ; Manjula Singh, Auteur ; Shahla Rahmani, Auteur . - 2012 . - pp. 5728-573.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5728-573
Mots-clés : Homogeneous catalysis Oxidation Kinetics Résumé : The present paper deals with the kinetics and mechanism of Pd(II)-catalyzed oxidation of tetracycline hydrate by Cu(Bip)22+ in alkaline medium. First-order kinetics with respect to [tetracycline hydrate] and fractional positive order kinetics in [Cu(II)] and [Pd(II)] was observed. Nil effect of [OH-] and [bipyridyl] on the rate of oxidation was observed. Almost no effect of ionic strength as well as dielectric constant of the medium on the rate of oxidation was observed. The reaction was studied at four different temperatures and observed values of rate constants were utilized to calculate various activation parameters specially the entropy of activation (ΔS#). With the help of the observed kinetic orders with respect to the reactants involved in the reaction, spechophotometric evidence collected for the formation of reactive complexes and the positive entropy of activation, a most probable reaction mechanism for Pd(II)-catalyzed oxidation of tetracycline hydrate by Cu(Bip)22+ in alkaline medium has been proposed. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25834486 Exemplaires
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Titre : Effect of sulfate modification on structure properties, surface acidity, and transesterification catalytic performance of titanium - submitted mesoporous molecular sieve Type de document : texte imprimé Auteurs : Shengping Wang, Auteur ; Yun Shi, Auteur ; Xinbin Ma, Auteur Année de publication : 2012 Article en page(s) : pp. 5737-5742 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Molecular sieve Catalytic reaction Transesterification Acidity Résumé : A series of sulfated titanium-submitted mesoporous molecular sieves denoted as S/Ti-MCM-41 were prepared by wet impregnation method with H2SO4 solution as promoter. The results of XRD, N2 adsorption-desorption, NH3-TPD, FTIR of pyridine adsorption, and XPS analysis indicated that S/Ti-MCM-41 samples possess well-ordered hexagonal mesostructure, although the pore diameter and specific surface area shrunk with the increasing coverage of sulfur species. As a result of the electron inductive effect from the S=O bond of SO42-, Lewis acidity is intensified significantly and new Brönsted acid sites are generated from the activated hydroxyl groups. Brönsted acid sites are medium strength, while part of the Lewis acid sites are of weak strength and part of them are medium. The S/Ti-MCM-41 catalysts exhibited desirable activity for transesterification of dimethyl oxalate and phenol. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25834487
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5737-5742[article] Effect of sulfate modification on structure properties, surface acidity, and transesterification catalytic performance of titanium - submitted mesoporous molecular sieve [texte imprimé] / Shengping Wang, Auteur ; Yun Shi, Auteur ; Xinbin Ma, Auteur . - 2012 . - pp. 5737-5742.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5737-5742
Mots-clés : Molecular sieve Catalytic reaction Transesterification Acidity Résumé : A series of sulfated titanium-submitted mesoporous molecular sieves denoted as S/Ti-MCM-41 were prepared by wet impregnation method with H2SO4 solution as promoter. The results of XRD, N2 adsorption-desorption, NH3-TPD, FTIR of pyridine adsorption, and XPS analysis indicated that S/Ti-MCM-41 samples possess well-ordered hexagonal mesostructure, although the pore diameter and specific surface area shrunk with the increasing coverage of sulfur species. As a result of the electron inductive effect from the S=O bond of SO42-, Lewis acidity is intensified significantly and new Brönsted acid sites are generated from the activated hydroxyl groups. Brönsted acid sites are medium strength, while part of the Lewis acid sites are of weak strength and part of them are medium. The S/Ti-MCM-41 catalysts exhibited desirable activity for transesterification of dimethyl oxalate and phenol. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25834487 Exemplaires
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Titre : Bacteria cellulose nanofibers supported palladium(0) nanocomposite and its catalysis evaluation in heck reaction Type de document : texte imprimé Auteurs : Peipei Zhou, Auteur ; Huanhuan Wang, Auteur ; Jiazhi Yang, Auteur Année de publication : 2012 Article en page(s) : pp. 5743-5748 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Catalysis Nanocomposite Bacteria Résumé : Bacteria cellulose (BC) nanofibers supported palladium(0) nanocomposites were prepared and fully characterized in terms of morphology, crystallinity, composition, and thermal stability. The as-prepared catalyst was further successfully explored in Heck coupling reaction between aryl halide and styrene or acrylates, with a yield over 86-96% for the first coupling reaction. With coupling yields decreased less than 10% for the fifth reaction cycle, Pd/BC catalyst exhibits great potential as recyclable catalyst for Heck coupling. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25834488
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5743-5748[article] Bacteria cellulose nanofibers supported palladium(0) nanocomposite and its catalysis evaluation in heck reaction [texte imprimé] / Peipei Zhou, Auteur ; Huanhuan Wang, Auteur ; Jiazhi Yang, Auteur . - 2012 . - pp. 5743-5748.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5743-5748
Mots-clés : Catalysis Nanocomposite Bacteria Résumé : Bacteria cellulose (BC) nanofibers supported palladium(0) nanocomposites were prepared and fully characterized in terms of morphology, crystallinity, composition, and thermal stability. The as-prepared catalyst was further successfully explored in Heck coupling reaction between aryl halide and styrene or acrylates, with a yield over 86-96% for the first coupling reaction. With coupling yields decreased less than 10% for the fifth reaction cycle, Pd/BC catalyst exhibits great potential as recyclable catalyst for Heck coupling. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25834488 Exemplaires
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Titre : Operational optimization of batch distillation systems Type de document : texte imprimé Auteurs : Santosh Jain, Auteur ; Jin-Kuk Kim, Auteur ; Robin Smith, Auteur Année de publication : 2012 Article en page(s) : pp. 5749–5761 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Batch distillation systems Résumé : The optimal operation of batch distillation systems has been studied in this paper. A new approach termed the limiting gradient approach is introduced for effectively identifying feasible and cost-effective operating profiles for batch distillation systems. A new semirigorous model for batch distillation has been presented for considering holdup of the column, which is applicable for different batch distillation configurations. A novel optimization model incorporating the limiting gradient approach has been proposed, which significantly reduces computational burden to search for a feasible operation of a batch distillation column by considerably reducing effort for carrying out a large number of dynamic simulations required for optimization. Case studies have been presented to demonstrate the applicability of the approach for various batch distillation configurations and to illustrate how the proposed optimization framework systematically addresses different performance indices and objectives. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201844g
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5749–5761[article] Operational optimization of batch distillation systems [texte imprimé] / Santosh Jain, Auteur ; Jin-Kuk Kim, Auteur ; Robin Smith, Auteur . - 2012 . - pp. 5749–5761.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5749–5761
Mots-clés : Batch distillation systems Résumé : The optimal operation of batch distillation systems has been studied in this paper. A new approach termed the limiting gradient approach is introduced for effectively identifying feasible and cost-effective operating profiles for batch distillation systems. A new semirigorous model for batch distillation has been presented for considering holdup of the column, which is applicable for different batch distillation configurations. A novel optimization model incorporating the limiting gradient approach has been proposed, which significantly reduces computational burden to search for a feasible operation of a batch distillation column by considerably reducing effort for carrying out a large number of dynamic simulations required for optimization. Case studies have been presented to demonstrate the applicability of the approach for various batch distillation configurations and to illustrate how the proposed optimization framework systematically addresses different performance indices and objectives. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201844g Exemplaires
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Titre : Simultaneous lot sizing and scheduling of multistage batch processes handling multiple orders per product Type de document : texte imprimé Auteurs : Pablo A. Marchetti, Auteur ; Carlos A. Méndez, Auteur ; Jaime Cerdá, Auteur Année de publication : 2012 Article en page(s) : pp. 5762-5780 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Handling Batchwise Scheduling Résumé : A pair of precedence-based continuous-time formulations addressing the combined lot sizing and scheduling of order-driven multistage batch facilities is presented. The proposed mixed-integer linear programming (MILP) models can handle multiple orders per product with different delivery dates, variable processing times, and sequence-dependent changeovers. As each order may be filled by one or more batches, enough batches for each order ensuring optimality are initially defined. The two monolithic formulations are intended for sequential batch processes where batch integrity is preserved throughout the entire production system. However, lots of final products can be split to satisfy two or more orders. One of the approaches is based on a detailed MILP formulation allocating individual batches to units and ordering them in every unit. In contrast, the second methodology is specially designed for large scheduling problems. It first gathers batches for the same order into clusters, and then assigns clusters to units and sequences groups of batches in every unit. The larger the number of groups, the more rigorous is the cluster-based formulation. Alternative sequencing constraints based on reliable assumptions were also tested. Several examples involving up to 92 batches have been successfully solved using one or both formulations. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25834490
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5762-5780[article] Simultaneous lot sizing and scheduling of multistage batch processes handling multiple orders per product [texte imprimé] / Pablo A. Marchetti, Auteur ; Carlos A. Méndez, Auteur ; Jaime Cerdá, Auteur . - 2012 . - pp. 5762-5780.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5762-5780
Mots-clés : Handling Batchwise Scheduling Résumé : A pair of precedence-based continuous-time formulations addressing the combined lot sizing and scheduling of order-driven multistage batch facilities is presented. The proposed mixed-integer linear programming (MILP) models can handle multiple orders per product with different delivery dates, variable processing times, and sequence-dependent changeovers. As each order may be filled by one or more batches, enough batches for each order ensuring optimality are initially defined. The two monolithic formulations are intended for sequential batch processes where batch integrity is preserved throughout the entire production system. However, lots of final products can be split to satisfy two or more orders. One of the approaches is based on a detailed MILP formulation allocating individual batches to units and ordering them in every unit. In contrast, the second methodology is specially designed for large scheduling problems. It first gathers batches for the same order into clusters, and then assigns clusters to units and sequences groups of batches in every unit. The larger the number of groups, the more rigorous is the cluster-based formulation. Alternative sequencing constraints based on reliable assumptions were also tested. Several examples involving up to 92 batches have been successfully solved using one or both formulations. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25834490 Exemplaires
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Titre : Generalized disjunctive programming as a systematic modeling framework to derive scheduling formulations Type de document : texte imprimé Auteurs : Pedro M. Castro, Auteur ; Ignacio E. Grossmann, Auteur Année de publication : 2012 Article en page(s) : pp. 5781–5792 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Disjunctive programming Scheduling Résumé : We propose linear generalized disjunctive programming (GDP) models for the short-term scheduling problem of single stage batch plants with parallel units. Three different concepts of continuous-time representation are explored, immediate and general precedence, as well as multiple time grids. The linear GDP models are then reformulated using both big-M and convex hull reformulations, and the resulting mixed-integer linear programming models compared through the solution of a set of example problems. We show that two general precedence models from the literature can be derived using a big-M reformulation for a set of disjunctions and a convex hull reformulation for another. The best performer is, however, a multiple time grid model which can be derived from the convex hull reformulation followed by simple algebraic manipulations to eliminate the disaggregated variables and reduce the sets of constraints, thus leading to a more compact and efficient formulation. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2030486
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5781–5792[article] Generalized disjunctive programming as a systematic modeling framework to derive scheduling formulations [texte imprimé] / Pedro M. Castro, Auteur ; Ignacio E. Grossmann, Auteur . - 2012 . - pp. 5781–5792.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5781–5792
Mots-clés : Disjunctive programming Scheduling Résumé : We propose linear generalized disjunctive programming (GDP) models for the short-term scheduling problem of single stage batch plants with parallel units. Three different concepts of continuous-time representation are explored, immediate and general precedence, as well as multiple time grids. The linear GDP models are then reformulated using both big-M and convex hull reformulations, and the resulting mixed-integer linear programming models compared through the solution of a set of example problems. We show that two general precedence models from the literature can be derived using a big-M reformulation for a set of disjunctions and a convex hull reformulation for another. The best performer is, however, a multiple time grid model which can be derived from the convex hull reformulation followed by simple algebraic manipulations to eliminate the disaggregated variables and reduce the sets of constraints, thus leading to a more compact and efficient formulation. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2030486 Exemplaires
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Titre : Reboiler separation efficiencies for binary systems Type de document : texte imprimé Auteurs : Branislav M. Jacimovic, Auteur ; Srbislav B. Genic, Auteur ; Nikola B. Jacimovic, Auteur Année de publication : 2012 Article en page(s) : pp. 5793-5804 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Binary system Reboiler Résumé : Reboilers are essential for the proper work of distillation and stripping columns. Hereby the intensity of axial mixing along the reboiler (Peclet number) is used for the reboiler separation efficiency modeling and estimation for binary systems. Two fully worked examples show that the separation (Murphree) efficiency varies significantly depending on the adopted reboiler flow model. Murphree efficiency ranges between 1.40 and 0.663 in example 1, and between 1.962 and 1 in example 2. The general conclusion is that the reboiler performance must be considered carefully in the case of design of the new plants,as well as in the case of “brown field” projects. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25834492
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5793-5804[article] Reboiler separation efficiencies for binary systems [texte imprimé] / Branislav M. Jacimovic, Auteur ; Srbislav B. Genic, Auteur ; Nikola B. Jacimovic, Auteur . - 2012 . - pp. 5793-5804.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5793-5804
Mots-clés : Binary system Reboiler Résumé : Reboilers are essential for the proper work of distillation and stripping columns. Hereby the intensity of axial mixing along the reboiler (Peclet number) is used for the reboiler separation efficiency modeling and estimation for binary systems. Two fully worked examples show that the separation (Murphree) efficiency varies significantly depending on the adopted reboiler flow model. Murphree efficiency ranges between 1.40 and 0.663 in example 1, and between 1.962 and 1 in example 2. The general conclusion is that the reboiler performance must be considered carefully in the case of design of the new plants,as well as in the case of “brown field” projects. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25834492 Exemplaires
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Titre : Novel simulated moving - bed cascades with a total of five zones for ternary separations Type de document : texte imprimé Auteurs : Wei Feng, Auteur ; Bo Shen, Auteur ; Mingjie Chen, Auteur Année de publication : 2012 Article en page(s) : pp. 5805–5812 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Separation ternary mixture Résumé : Two simulated moving-bed (SMB) cascades are proposed for the separation of a ternary mixture containing the least, medium-, and most retained solutes (A, B, and C). Each cascade has a total of five zones. The first cascade combines two three-zone SMBs sharing zone III: the one SMB with zones I to III separates (A+B+C) into A and (B+C), and the other three-zone SMB with zones III to V separates (B+C) into B and C. The second cascade combines a four-zone SMB consisting of zones I to IV and a three-zone SMB comprising zones IV, V and I: the former separates (A+B+C) into (A+B) and C, and the latter separates (A+B) into A and B. Analysis of the concentration band movement together with a modeling study confirms the feasibilities of the two cascades, suggesting that the first cascade should be adopted if the separation of (A+B) and C is easier than that of A and (B+C), and otherwise, the second cascade should be used. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2024189
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5805–5812[article] Novel simulated moving - bed cascades with a total of five zones for ternary separations [texte imprimé] / Wei Feng, Auteur ; Bo Shen, Auteur ; Mingjie Chen, Auteur . - 2012 . - pp. 5805–5812.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5805–5812
Mots-clés : Separation ternary mixture Résumé : Two simulated moving-bed (SMB) cascades are proposed for the separation of a ternary mixture containing the least, medium-, and most retained solutes (A, B, and C). Each cascade has a total of five zones. The first cascade combines two three-zone SMBs sharing zone III: the one SMB with zones I to III separates (A+B+C) into A and (B+C), and the other three-zone SMB with zones III to V separates (B+C) into B and C. The second cascade combines a four-zone SMB consisting of zones I to IV and a three-zone SMB comprising zones IV, V and I: the former separates (A+B+C) into (A+B) and C, and the latter separates (A+B) into A and B. Analysis of the concentration band movement together with a modeling study confirms the feasibilities of the two cascades, suggesting that the first cascade should be adopted if the separation of (A+B) and C is easier than that of A and (B+C), and otherwise, the second cascade should be used. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2024189 Exemplaires
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Titre : Preparation of a solid adsorbent derived from concrete sludge and its boron removal performance Type de document : texte imprimé Auteurs : Takeshi Sasaki, Auteur ; Yuka Sakai, Auteur ; Teruhisa Hongo, Auteur Année de publication : 2012 Article en page(s) : pp. 5813–5817 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Adsorbent Concrete sludge Résumé : We prepared a solid adsorbent for boron removal using real concrete sludge. The sludge was diluted with water at dilution ratios from 1 to 15. The diluted concrete sludge was then filtered and dried. Two types of drying methods were examined: natural drying under atmospheric conditions and forced drying in an oven at 105 °C. The boron removal performance was examined using a boric acid solution containing 100 mgB/L. All of the adsorbents prepared showed boron removal capacity. The adsorbent prepared with dilution ratio 10 and forced drying exhibited the highest boron removal capacity; the boron concentration after 24 h was just 3.33 mg/L, which is below the Japanese standard for industrial effluent (10 mg/L), and the maximum adsorption capacity for boron was 50 mgboron/gadsorbent. The drying method had a significant effect on both the rate and capacity of boron removal. With natural drying under atmospheric conditions, the adsorption initially proceeded quickly, but the final amount adsorbed was lower than that for the force-dried adsorbents. The boron removal can be attributed to ion exchange and uptake of boron in the ettringite phase. These results indicate that boron adsorbents prepared from concrete sludge can be applied for the removal of boron from effluents. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2024646
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5813–5817[article] Preparation of a solid adsorbent derived from concrete sludge and its boron removal performance [texte imprimé] / Takeshi Sasaki, Auteur ; Yuka Sakai, Auteur ; Teruhisa Hongo, Auteur . - 2012 . - pp. 5813–5817.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5813–5817
Mots-clés : Adsorbent Concrete sludge Résumé : We prepared a solid adsorbent for boron removal using real concrete sludge. The sludge was diluted with water at dilution ratios from 1 to 15. The diluted concrete sludge was then filtered and dried. Two types of drying methods were examined: natural drying under atmospheric conditions and forced drying in an oven at 105 °C. The boron removal performance was examined using a boric acid solution containing 100 mgB/L. All of the adsorbents prepared showed boron removal capacity. The adsorbent prepared with dilution ratio 10 and forced drying exhibited the highest boron removal capacity; the boron concentration after 24 h was just 3.33 mg/L, which is below the Japanese standard for industrial effluent (10 mg/L), and the maximum adsorption capacity for boron was 50 mgboron/gadsorbent. The drying method had a significant effect on both the rate and capacity of boron removal. With natural drying under atmospheric conditions, the adsorption initially proceeded quickly, but the final amount adsorbed was lower than that for the force-dried adsorbents. The boron removal can be attributed to ion exchange and uptake of boron in the ettringite phase. These results indicate that boron adsorbents prepared from concrete sludge can be applied for the removal of boron from effluents. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2024646 Exemplaires
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Titre : Modeling of hydrate dissociation conditions for alkanes in the presence of single and mixed electrolyte solutions using ion - based statistical associating fluid theory Type de document : texte imprimé Auteurs : Hao Jiang, Auteur ; Hertanto Adidharma, Auteur Année de publication : 2012 Article en page(s) : pp. 5818–5825 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Electrolyte Fluid theory Résumé : Ion-based statistical associating fluid theory (SAFT2), coupled with the van der Waals and Platteeuw model for hydrate phase, is applied to describe the hydrate dissociation conditions for methane, ethane, and propane in the presence of single and mixed electrolyte solutions containing NaCl, KCl, and CaCl2. The model, which can be conveniently applied to mixed electrolyte solutions, is found to provide accurate predictions of the hydrate inhibition effects of these electrolyte solutions. The effect of different salt concentrations on the alkane hydrate dissociation conditions is also well-captured. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300170w
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5818–5825[article] Modeling of hydrate dissociation conditions for alkanes in the presence of single and mixed electrolyte solutions using ion - based statistical associating fluid theory [texte imprimé] / Hao Jiang, Auteur ; Hertanto Adidharma, Auteur . - 2012 . - pp. 5818–5825.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5818–5825
Mots-clés : Electrolyte Fluid theory Résumé : Ion-based statistical associating fluid theory (SAFT2), coupled with the van der Waals and Platteeuw model for hydrate phase, is applied to describe the hydrate dissociation conditions for methane, ethane, and propane in the presence of single and mixed electrolyte solutions containing NaCl, KCl, and CaCl2. The model, which can be conveniently applied to mixed electrolyte solutions, is found to provide accurate predictions of the hydrate inhibition effects of these electrolyte solutions. The effect of different salt concentrations on the alkane hydrate dissociation conditions is also well-captured. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300170w Exemplaires
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Titre : Short communication : Comments on the role of gas - phase axial thermal dispersion and solid - phase thermal conduction for heat transfer in a packed bed of solid particles Type de document : texte imprimé Auteurs : Michael G. Beaver, Auteur ; Shivaji Sircar, Auteur Année de publication : 2012 Article en page(s) : pp. 5826-5829 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Solid particle Packed bed Heat transfer Thermal conduction Dispersion Résumé : The effects of gas-phase axial thermal dispersion and solid-phase thermal conduction on gas-solid heat transfer in a packed bed of solid particles was numerically studied using a simplified conduction-dispersion model for heat transfer in conjunction with a realistic set of boundary conditions. It is reconfirmed that the exclusion of gas-phase thermal axial dispersion in the model analysis of gas-solid heat transfer coefficients can result in misleading interpretation of heat transfer in packed beds, particularly in the low Reynolds number gas flow region. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25834496
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5826-5829[article] Short communication : Comments on the role of gas - phase axial thermal dispersion and solid - phase thermal conduction for heat transfer in a packed bed of solid particles [texte imprimé] / Michael G. Beaver, Auteur ; Shivaji Sircar, Auteur . - 2012 . - pp. 5826-5829.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5826-5829
Mots-clés : Solid particle Packed bed Heat transfer Thermal conduction Dispersion Résumé : The effects of gas-phase axial thermal dispersion and solid-phase thermal conduction on gas-solid heat transfer in a packed bed of solid particles was numerically studied using a simplified conduction-dispersion model for heat transfer in conjunction with a realistic set of boundary conditions. It is reconfirmed that the exclusion of gas-phase thermal axial dispersion in the model analysis of gas-solid heat transfer coefficients can result in misleading interpretation of heat transfer in packed beds, particularly in the low Reynolds number gas flow region. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25834496 Exemplaires
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Titre : N,N - dichlorovaleramide : An efficient decontaminating reagent for sulfur mustard Type de document : texte imprimé Auteurs : Pranav K. Gutch, Auteur ; Avik Mazumder, Auteur Année de publication : 2012 Article en page(s) : pp. 5830-5837 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Chemical decontamination Gas Résumé : An efficient and operationally simple method for the chemical decontamination of sulfur mustard (HD) has been reported herein. A newly synthesized (positive chlorine bearing) reagent N,N-dichlorovaleramide has been utilized for this purpose. Decontamination has been achieved in aqueous and aprotic media. The reaction was monitored by gas chromatography-mass spectrometry and NMR spectroscopy. This reagent is more effective, stable, economical, and easy to synthesize and leads to instant decontamination of HD. The reaction was found to instantaneously and completely convert HD to innocuous products at different temperatures (-10 to 25 °C). ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201811v
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5830-5837[article] N,N - dichlorovaleramide : An efficient decontaminating reagent for sulfur mustard [texte imprimé] / Pranav K. Gutch, Auteur ; Avik Mazumder, Auteur . - 2012 . - pp. 5830-5837.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 16 (Avril 2012) . - pp. 5830-5837
Mots-clés : Chemical decontamination Gas Résumé : An efficient and operationally simple method for the chemical decontamination of sulfur mustard (HD) has been reported herein. A newly synthesized (positive chlorine bearing) reagent N,N-dichlorovaleramide has been utilized for this purpose. Decontamination has been achieved in aqueous and aprotic media. The reaction was monitored by gas chromatography-mass spectrometry and NMR spectroscopy. This reagent is more effective, stable, economical, and easy to synthesize and leads to instant decontamination of HD. The reaction was found to instantaneously and completely convert HD to innocuous products at different temperatures (-10 to 25 °C). ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201811v Exemplaires
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