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Vol. 50 N° 10 - Mai 2011 [texte imprimé] . - 2011 . - p. 5881-6516 : ill. ; 28 cm. Chemical engineering Langues : Anglais (eng)
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Ajouter le résultat dans votre panierModified silica sol coatings for highly hydrophobic cotton and polyester fabrics using a one-step procedure / Quan Zhu in Industrial & engineering chemistry research, Vol. 50 N° 10 (Mai 2011)
Titre : Modified silica sol coatings for highly hydrophobic cotton and polyester fabrics using a one-step procedure Type de document : texte imprimé Auteurs : Quan Zhu, Auteur ; Qinwen Gao, Auteur ; Yuliang Guo, Auteur Année de publication : 2011 Article en page(s) : pp. 5881-5888 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Sol coatings Highly hydrophobic cotton Polyester Résumé : The applications of water-resistant and stain-resistant finishes to apparel have become widespread in recent years due to high consumer demand. In our previous research, we studied the formation of highly hydrophobic surfaces on cotton and polyester fabrics using a two-step treatment procedure, i.e., first forming silica sol by hydrolysis and subsequent condensation of tetraethoxysilane under alkaline conditions, applying the sol to the surfaces of cotton and polyester fabrics, and then applying hydrolyzed hexadecyltrimethoxysilane on the treated fabrics to impart hydrophobicity to the surfaces of the fabrics. In this research, we developed a novel one-step procedure to form highly hydrophobic surfaces on cotton and polyester fabrics using different modified silica sols. The first series of modified silica sol ("sol A") was prepared by the reactions of a sol formed by alkaline hydrolysis of tetraethoxysilane and alkyltrialkoxysilanes in a NH4OH-ethanol solution. A second series ("sol B") was prepared by the reactions of a sol formed by the same method, followed by adding (3-glycidylosypropyl)trimethoaysilane and alkyltrialkoxysilanes to the sol. The cotton and polyester fabrics treated with the two modified silica sol systems showed excellent water repellency with the water contact angle above 150° on cotton and above 140° on polyester under the optimum treatment conditions. The treated cotton and polyester had significantly improved hydrolysis resistance and maintained high levels of hydrophobicity after 30 laundering cycles. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158883
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 5881-5888[article] Modified silica sol coatings for highly hydrophobic cotton and polyester fabrics using a one-step procedure [texte imprimé] / Quan Zhu, Auteur ; Qinwen Gao, Auteur ; Yuliang Guo, Auteur . - 2011 . - pp. 5881-5888.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 5881-5888
Mots-clés : Sol coatings Highly hydrophobic cotton Polyester Résumé : The applications of water-resistant and stain-resistant finishes to apparel have become widespread in recent years due to high consumer demand. In our previous research, we studied the formation of highly hydrophobic surfaces on cotton and polyester fabrics using a two-step treatment procedure, i.e., first forming silica sol by hydrolysis and subsequent condensation of tetraethoxysilane under alkaline conditions, applying the sol to the surfaces of cotton and polyester fabrics, and then applying hydrolyzed hexadecyltrimethoxysilane on the treated fabrics to impart hydrophobicity to the surfaces of the fabrics. In this research, we developed a novel one-step procedure to form highly hydrophobic surfaces on cotton and polyester fabrics using different modified silica sols. The first series of modified silica sol ("sol A") was prepared by the reactions of a sol formed by alkaline hydrolysis of tetraethoxysilane and alkyltrialkoxysilanes in a NH4OH-ethanol solution. A second series ("sol B") was prepared by the reactions of a sol formed by the same method, followed by adding (3-glycidylosypropyl)trimethoaysilane and alkyltrialkoxysilanes to the sol. The cotton and polyester fabrics treated with the two modified silica sol systems showed excellent water repellency with the water contact angle above 150° on cotton and above 140° on polyester under the optimum treatment conditions. The treated cotton and polyester had significantly improved hydrolysis resistance and maintained high levels of hydrophobicity after 30 laundering cycles. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158883 Exemplaires
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Titre : Cross-linking cotton cellulose by the combination of maleic acid and sodium hypophosphite. 2. fabric fire performance Type de document : texte imprimé Auteurs : Charles Q. Yang, Auteur ; Qingliang He, Auteur ; Bojana Voncina, Auteur Année de publication : 2011 Article en page(s) : pp. 5889-5897 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Fires Résumé : Multifunctional carboxylic acids have been used as durable press finishing agents for cotton with sodium hypophosphite (NaH2PO2) as the most effective catalyst. In our previous research, we found that cellulose cross-linking takes place when cotton fabric treated with a combination of maleic acid and NaH2PO2 is cured at ≥150°C. The data suggested that H-P-H of hypophosphite likely reacts with >C=C DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158884
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 5889-5897[article] Cross-linking cotton cellulose by the combination of maleic acid and sodium hypophosphite. 2. fabric fire performance [texte imprimé] / Charles Q. Yang, Auteur ; Qingliang He, Auteur ; Bojana Voncina, Auteur . - 2011 . - pp. 5889-5897.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 5889-5897
Mots-clés : Fires Résumé : Multifunctional carboxylic acids have been used as durable press finishing agents for cotton with sodium hypophosphite (NaH2PO2) as the most effective catalyst. In our previous research, we found that cellulose cross-linking takes place when cotton fabric treated with a combination of maleic acid and NaH2PO2 is cured at ≥150°C. The data suggested that H-P-H of hypophosphite likely reacts with >C=C DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158884 Exemplaires
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Titre : Sulfonic acid-functionalized catalysts for the valorization of glycerol via transesterification with methyl acetate Type de document : texte imprimé Auteurs : Gabriel Morales, Auteur ; Marta Paniagua, Auteur ; Juan A. Melero, Auteur Année de publication : 2011 Article en page(s) : pp. 5898-5906 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Transesterification Upgrading Catalyst Résumé : Sulfonic acid-functionalized mesostructured SBA-15 silicas have been demonstrated to be active for the catalytic transesterification of glycerol with methyl acetate to produce di- and triacetylglycerols. An optimization of the reaction conditions carried out with pharmaceutical glycerol by means of experimental design methodology showed that it is necessary to use a high methyl acetate to glycerol molar ratio (50:1) and a high catalyst loading (7.5 wt % based on glycerol) in order to obtain simultaneously very high glycerol conversion (99.5%) and high combined selectivity toward di- and triacetylglycerols (74.2%). In addition, the formation of nondesired byproduct was minimized at such reaction conditions. The activity displayed by arenesulfonic acid-functionalized mesostructured silica was comparable to that displayed by commercial catalysts such as the resin Amberlyst-70 or the composite Nafion-SAC-13. The acid strength of the catalytic sites, and in less extent their surface density, proved to be the most influential parameters in this reaction. Arenesulfonic SBA-15 also provided suitable conversions and selectivities with technical-grade glycerol, although not with crude glycerol due to the deactivating effect of salts. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158885
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 5898-5906[article] Sulfonic acid-functionalized catalysts for the valorization of glycerol via transesterification with methyl acetate [texte imprimé] / Gabriel Morales, Auteur ; Marta Paniagua, Auteur ; Juan A. Melero, Auteur . - 2011 . - pp. 5898-5906.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 5898-5906
Mots-clés : Transesterification Upgrading Catalyst Résumé : Sulfonic acid-functionalized mesostructured SBA-15 silicas have been demonstrated to be active for the catalytic transesterification of glycerol with methyl acetate to produce di- and triacetylglycerols. An optimization of the reaction conditions carried out with pharmaceutical glycerol by means of experimental design methodology showed that it is necessary to use a high methyl acetate to glycerol molar ratio (50:1) and a high catalyst loading (7.5 wt % based on glycerol) in order to obtain simultaneously very high glycerol conversion (99.5%) and high combined selectivity toward di- and triacetylglycerols (74.2%). In addition, the formation of nondesired byproduct was minimized at such reaction conditions. The activity displayed by arenesulfonic acid-functionalized mesostructured silica was comparable to that displayed by commercial catalysts such as the resin Amberlyst-70 or the composite Nafion-SAC-13. The acid strength of the catalytic sites, and in less extent their surface density, proved to be the most influential parameters in this reaction. Arenesulfonic SBA-15 also provided suitable conversions and selectivities with technical-grade glycerol, although not with crude glycerol due to the deactivating effect of salts. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158885 Exemplaires
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Titre : Wet cross-linking of cellulose fibers via a bioconjugation reaction Type de document : texte imprimé Auteurs : Alvaro Tejado, Auteur ; Miro Antal, Auteur ; Xiaojun Liu, Auteur Année de publication : 2011 Article en page(s) : pp. 5907-5913 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Cellulose Fiber Résumé : A well-known bioconjugation reaction, the EDC-assisted reaction of carboxyl and amine groups, is shown to be extremely well-adapted for cross-linking fibers under papermaking conditions. By using such chemistry we obtained increases as high as 500% and 100% in the wet-web strength (WWS) of papers made from, respectively, unbeaten and beaten hardwood kraft pulps, after pretreating the fibers with carboxymethyl cellulose and using adipic dihydrazide as the cross-linker. These increments exceed previous attempts in most cases by about 1 order of magnitude. Experiments show that the cross-linking reaction does not counteract the beating effect, as has usually occurred in the past for other cross-linking routes, but instead complements it. The ability ofEDC for promoting covalent bonding under very wet conditions appears to make it an excellent agent for the enhancement of the WWS of paper, the property that ultimately determines the runnability of a papermaking machine. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158886
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 5907-5913[article] Wet cross-linking of cellulose fibers via a bioconjugation reaction [texte imprimé] / Alvaro Tejado, Auteur ; Miro Antal, Auteur ; Xiaojun Liu, Auteur . - 2011 . - pp. 5907-5913.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 5907-5913
Mots-clés : Cellulose Fiber Résumé : A well-known bioconjugation reaction, the EDC-assisted reaction of carboxyl and amine groups, is shown to be extremely well-adapted for cross-linking fibers under papermaking conditions. By using such chemistry we obtained increases as high as 500% and 100% in the wet-web strength (WWS) of papers made from, respectively, unbeaten and beaten hardwood kraft pulps, after pretreating the fibers with carboxymethyl cellulose and using adipic dihydrazide as the cross-linker. These increments exceed previous attempts in most cases by about 1 order of magnitude. Experiments show that the cross-linking reaction does not counteract the beating effect, as has usually occurred in the past for other cross-linking routes, but instead complements it. The ability ofEDC for promoting covalent bonding under very wet conditions appears to make it an excellent agent for the enhancement of the WWS of paper, the property that ultimately determines the runnability of a papermaking machine. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158886 Exemplaires
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Titre : Effects of reaction conditions on elemental mercury oxidation in simulated flue gas by DC nonthermal plasma Type de document : texte imprimé Auteurs : Meiyan Wang, Auteur ; Tianle Zhu, Auteur ; Hongjing Luo, Auteur Année de publication : 2011 Article en page(s) : pp. 5914-5919 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Non thermal plasma Gaseous effluent Oxidation Zerovalent metal Résumé : The effects of discharge polarity, discharge electrode configuration, O2/CO2 ratio, and water vapor on the elemental mercury (Hg0) oxidation in simulated flue gas were investigated in a wire-cylinder plasma reactor energized by DC power. The Hg0 oxidation efficiency increases with the increase of specific energy density (SED). Compared with the glow corona discharge energized by negative DC high voltage, the streamer corona discharge induced by positive DC high voltage exhibits a much higher Hg0 oxidation efficiency under identical SED. The discharge electrode configuration significantly influences the energy density in the plasma reactor, but hardly affects Hg0 oxidation for a fixed SED. The increase of O2/CO2 ratio in simulated flue gas obviously enhances Hg0 oxidation. However, with the addition of H2O, Hg0 oxidation is remarkably restrained due to the decrease of O3 formation. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158887
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 5914-5919[article] Effects of reaction conditions on elemental mercury oxidation in simulated flue gas by DC nonthermal plasma [texte imprimé] / Meiyan Wang, Auteur ; Tianle Zhu, Auteur ; Hongjing Luo, Auteur . - 2011 . - pp. 5914-5919.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 5914-5919
Mots-clés : Non thermal plasma Gaseous effluent Oxidation Zerovalent metal Résumé : The effects of discharge polarity, discharge electrode configuration, O2/CO2 ratio, and water vapor on the elemental mercury (Hg0) oxidation in simulated flue gas were investigated in a wire-cylinder plasma reactor energized by DC power. The Hg0 oxidation efficiency increases with the increase of specific energy density (SED). Compared with the glow corona discharge energized by negative DC high voltage, the streamer corona discharge induced by positive DC high voltage exhibits a much higher Hg0 oxidation efficiency under identical SED. The discharge electrode configuration significantly influences the energy density in the plasma reactor, but hardly affects Hg0 oxidation for a fixed SED. The increase of O2/CO2 ratio in simulated flue gas obviously enhances Hg0 oxidation. However, with the addition of H2O, Hg0 oxidation is remarkably restrained due to the decrease of O3 formation. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158887 Exemplaires
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Titre : pH-Dependent interactions between lead and typha angustifolia biomass in the biosorption process Type de document : texte imprimé Auteurs : Wu-Jun Liu, Auteur ; Fan-Xin Zeng, Auteur ; Jiang Hong, Auteur Année de publication : 2011 Article en page(s) : pp. 5920-5926 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Biosorption Biomass pH Résumé : Removal of heavy metals from wastewater by biosorption is an attractive approach. In this work, the interactions between lead and Typha angustifolia biomass, a cost-effective biosorbent, were investigated It was found that the interactions between lead and T. angustifolia biomass were complex, and the solution pH was a key factor governing such interactions. The FTIR characterization and the results of blocking experiment indicate the amino, hydroxyl, and carboxyl are the main functional groups contributing to these interactions. A synergistic mechanism involving ion exchange, complexation, and hydrogen binding was elucidated. According to this mechanism, the dominant interactions between the biomass and lead altered with the variation of pH, which was consistent with the experimental results. Additionally, a simple method was explored to estimate the contributions of different interactions between the biomass and lead. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158888
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 5920-5926[article] pH-Dependent interactions between lead and typha angustifolia biomass in the biosorption process [texte imprimé] / Wu-Jun Liu, Auteur ; Fan-Xin Zeng, Auteur ; Jiang Hong, Auteur . - 2011 . - pp. 5920-5926.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 5920-5926
Mots-clés : Biosorption Biomass pH Résumé : Removal of heavy metals from wastewater by biosorption is an attractive approach. In this work, the interactions between lead and Typha angustifolia biomass, a cost-effective biosorbent, were investigated It was found that the interactions between lead and T. angustifolia biomass were complex, and the solution pH was a key factor governing such interactions. The FTIR characterization and the results of blocking experiment indicate the amino, hydroxyl, and carboxyl are the main functional groups contributing to these interactions. A synergistic mechanism involving ion exchange, complexation, and hydrogen binding was elucidated. According to this mechanism, the dominant interactions between the biomass and lead altered with the variation of pH, which was consistent with the experimental results. Additionally, a simple method was explored to estimate the contributions of different interactions between the biomass and lead. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158888 Exemplaires
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Titre : High temperature carbonation of Ca(OH)2 Type de document : texte imprimé Auteurs : Vlatko Materic, Auteur ; Stuart I. Smedley, Auteur Année de publication : 2011 Article en page(s) : pp. 5927-5932 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Carbonation Résumé : Steam hydration is reported to be an effective method for reactivating spent sorbents in calcium looping applications; however, uncertainties remain regarding the optimal method of returning the hydrated sorbent to the CO2 capture loop. Carbonation conversions were found to be higher when Ca(OH)2 was directly carbonated at high temperatures compared to conversions reached when Ca(OH)2 was dehydrated prior to carbonation. This observation can lead to improved hydration based reactivation techniques for calcium looping applications. Upon heating in CO2, calcium hydroxide remained stable at temperatures >450 °C and the extent of carbonation was controlled by temperature only. The carbonation mechanism of Ca(OH)2 at high temperatures appears to be more complex than the expected simple mechanism comprising the dehydration reaction of Ca(OH)2 and the subsequent carbonation of the resulting CaO. An alternate mechanism was proposed, involving the formation of liquid like layers of water on the surface of Ca(OH)2. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158889
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 5927-5932[article] High temperature carbonation of Ca(OH)2 [texte imprimé] / Vlatko Materic, Auteur ; Stuart I. Smedley, Auteur . - 2011 . - pp. 5927-5932.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 5927-5932
Mots-clés : Carbonation Résumé : Steam hydration is reported to be an effective method for reactivating spent sorbents in calcium looping applications; however, uncertainties remain regarding the optimal method of returning the hydrated sorbent to the CO2 capture loop. Carbonation conversions were found to be higher when Ca(OH)2 was directly carbonated at high temperatures compared to conversions reached when Ca(OH)2 was dehydrated prior to carbonation. This observation can lead to improved hydration based reactivation techniques for calcium looping applications. Upon heating in CO2, calcium hydroxide remained stable at temperatures >450 °C and the extent of carbonation was controlled by temperature only. The carbonation mechanism of Ca(OH)2 at high temperatures appears to be more complex than the expected simple mechanism comprising the dehydration reaction of Ca(OH)2 and the subsequent carbonation of the resulting CaO. An alternate mechanism was proposed, involving the formation of liquid like layers of water on the surface of Ca(OH)2. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158889 Exemplaires
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Titre : Hydrodynamics of a fluid catalytic cracking stripper using γ-ray densitometry Type de document : texte imprimé Auteurs : Ganesh K. Veluswamy, Auteur ; Rajesh K. Upadhyay, Auteur ; Ranjeet P. Utikar, Auteur Année de publication : 2011 Article en page(s) : pp. 5933-5941 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Densitometry Fluid catalytic cracking Hydrodynamics Résumé : This paper reports hydrodynamics of a laboratory-scale fluid catalytic cracking (FCC) stripper. The laboratory-scale stripper was designed by geometrically and dynamically scaling down an industrial-scale FCC stripper that had a disk and donut baffle. The solids holdup was measured using a γ-ray densitometry technique with a 3-μCi-strength Cs-137 radioactive source. Measurements were taken at different elevations and chordal positions. The effect of operating conditions on the solids holdup profiles was investigated in detail. For example, the particle flow rate was varied from 0.025 kg/s to 0.042 kg/s, and the superficial air velocity between 0.74 m/s and 1.1 m/s. It was observed that the shape of baffles played an important role in the hydrodynamics of the stripper. Several dead zones were noticed under the baffle regions indicating unused areas in the stripper. The measured solid holdup radial profiles were of asymmetric nature underlying the need for three-dimensional (3D) simulations. At low superficial gas velocities, there was a widespread segregation in the solid phase, which along with the solid holdup decreased on increasing the air superficial velocity. However, the change in solid flow rates did not have any effect on the solids holdup. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158890
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 5933-5941[article] Hydrodynamics of a fluid catalytic cracking stripper using γ-ray densitometry [texte imprimé] / Ganesh K. Veluswamy, Auteur ; Rajesh K. Upadhyay, Auteur ; Ranjeet P. Utikar, Auteur . - 2011 . - pp. 5933-5941.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 5933-5941
Mots-clés : Densitometry Fluid catalytic cracking Hydrodynamics Résumé : This paper reports hydrodynamics of a laboratory-scale fluid catalytic cracking (FCC) stripper. The laboratory-scale stripper was designed by geometrically and dynamically scaling down an industrial-scale FCC stripper that had a disk and donut baffle. The solids holdup was measured using a γ-ray densitometry technique with a 3-μCi-strength Cs-137 radioactive source. Measurements were taken at different elevations and chordal positions. The effect of operating conditions on the solids holdup profiles was investigated in detail. For example, the particle flow rate was varied from 0.025 kg/s to 0.042 kg/s, and the superficial air velocity between 0.74 m/s and 1.1 m/s. It was observed that the shape of baffles played an important role in the hydrodynamics of the stripper. Several dead zones were noticed under the baffle regions indicating unused areas in the stripper. The measured solid holdup radial profiles were of asymmetric nature underlying the need for three-dimensional (3D) simulations. At low superficial gas velocities, there was a widespread segregation in the solid phase, which along with the solid holdup decreased on increasing the air superficial velocity. However, the change in solid flow rates did not have any effect on the solids holdup. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158890 Exemplaires
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Titre : Selective catalytic reduction for NO removal : comparison of transfer and reaction performances among monolith catalysts Type de document : texte imprimé Auteurs : Zhigang Lei, Auteur ; Cuiping Wen, Auteur ; Jie Zhang, Auteur Année de publication : 2011 Article en page(s) : pp 5942–5951 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Monolith catalysts Résumé : One of the available technologies that can effectively control the emission of NOx is the selective catalytic reduction (SCR) of NOx with ammonia (NH3). Monolith catalysts are widely used in this technology due to their unique advantages that they offer, like low pressure drop, high external geometric surface area, and resistance to deposition of carbon, dust, and metals from combustion process. But the configuration of monolith catalysts has prominent influence on transfer and reaction performances of SCR for NO removal. This work tries to provide an easy-to-read and comprehensive comparison of momentum transfer, heat transfer, mass transfer, and reaction performance between two types of monolith catalysts with five kinds of channel shapes for SCR for NO removal, and to address the issues specific to SCR applications as to (i) whether or not monolith catalysts can improve the transfer and reaction performances compared to traditional pellet packed-bed reactors; (ii) which type of monolith catalysts and (iii) which kind of channel shapes for each type are optimum from the viewpoint of chemical reaction engineering. It was found that monolith catalysts have a much lower pressure drop and higher effectiveness factor than traditional pellet packed-bed reactors, and a coating catalyst seems more suitable than an extruded catalyst for SCR for NO removal. Although a round channel brings the best heat and mass transfer, a triangle-shaped channel of coating catalyst possesses the highest NOx conversion due to the chemical reaction being the controlling step. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102206x
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp 5942–5951[article] Selective catalytic reduction for NO removal : comparison of transfer and reaction performances among monolith catalysts [texte imprimé] / Zhigang Lei, Auteur ; Cuiping Wen, Auteur ; Jie Zhang, Auteur . - 2011 . - pp 5942–5951.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp 5942–5951
Mots-clés : Monolith catalysts Résumé : One of the available technologies that can effectively control the emission of NOx is the selective catalytic reduction (SCR) of NOx with ammonia (NH3). Monolith catalysts are widely used in this technology due to their unique advantages that they offer, like low pressure drop, high external geometric surface area, and resistance to deposition of carbon, dust, and metals from combustion process. But the configuration of monolith catalysts has prominent influence on transfer and reaction performances of SCR for NO removal. This work tries to provide an easy-to-read and comprehensive comparison of momentum transfer, heat transfer, mass transfer, and reaction performance between two types of monolith catalysts with five kinds of channel shapes for SCR for NO removal, and to address the issues specific to SCR applications as to (i) whether or not monolith catalysts can improve the transfer and reaction performances compared to traditional pellet packed-bed reactors; (ii) which type of monolith catalysts and (iii) which kind of channel shapes for each type are optimum from the viewpoint of chemical reaction engineering. It was found that monolith catalysts have a much lower pressure drop and higher effectiveness factor than traditional pellet packed-bed reactors, and a coating catalyst seems more suitable than an extruded catalyst for SCR for NO removal. Although a round channel brings the best heat and mass transfer, a triangle-shaped channel of coating catalyst possesses the highest NOx conversion due to the chemical reaction being the controlling step. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102206x Exemplaires
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Titre : Experimental study on liquid–liquid macromixing in a stirred tank Type de document : texte imprimé Auteurs : Yanchun Zhao, Auteur ; Xiangyang Li, Auteur ; Jingcai Cheng, Auteur Année de publication : 2011 Article en page(s) : pp. 5952-5958 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Stirred vessel Macromixing Résumé : In this paper, the experimental data on the mixing time and power consumption of two immiscible liquids in a mechanically agitated baffled tank are presented. The electric conductivity method was taken for the measurement of the mixing time and the shaft-torque method for the power consumption measurement Tap water was used as the continuous phase and kerosene the dispersed phase. The effects of the agitation speed, type of impeller, clearance of the impeller off the tank bottom, volume fraction of the dispersed phase, physical properties of the liquids, and probe position on the macromixing of the liquid-liquid system were studied. The phenomena of macromixing are largely similar to those of single-liquid and gas-liquid stirred tanks. The experiment indicates that the flow field and turbulence can be dampened at high volume fraction of the dispersed phase while enhanced at low percentage. The mixing time becomes longer with increasing viscosity of the dispersed phase. The results show that the pitched blade turbine downflow is more efficient for macromixing than the others tested in this work. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158892
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 5952-5958[article] Experimental study on liquid–liquid macromixing in a stirred tank [texte imprimé] / Yanchun Zhao, Auteur ; Xiangyang Li, Auteur ; Jingcai Cheng, Auteur . - 2011 . - pp. 5952-5958.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 5952-5958
Mots-clés : Stirred vessel Macromixing Résumé : In this paper, the experimental data on the mixing time and power consumption of two immiscible liquids in a mechanically agitated baffled tank are presented. The electric conductivity method was taken for the measurement of the mixing time and the shaft-torque method for the power consumption measurement Tap water was used as the continuous phase and kerosene the dispersed phase. The effects of the agitation speed, type of impeller, clearance of the impeller off the tank bottom, volume fraction of the dispersed phase, physical properties of the liquids, and probe position on the macromixing of the liquid-liquid system were studied. The phenomena of macromixing are largely similar to those of single-liquid and gas-liquid stirred tanks. The experiment indicates that the flow field and turbulence can be dampened at high volume fraction of the dispersed phase while enhanced at low percentage. The mixing time becomes longer with increasing viscosity of the dispersed phase. The results show that the pitched blade turbine downflow is more efficient for macromixing than the others tested in this work. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158892 Exemplaires
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Titre : Parametric study of gasification processes in a BFB coal gasifier Type de document : texte imprimé Auteurs : L. M. Armstrong, Auteur ; S. Gu, Auteur ; K. H. Luo, Auteur Année de publication : 2011 Article en page(s) : pp. 5959–5974 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Gasification processes Résumé : An Eulerian-Eulerian computational fluid dynamics (CFD) model of the gasification processes in a coal bubbling fluidized bed (BFB) is presented based on the experimental setup taken from the literature. The base model is modified to account for different parameter changes in the model setup. The exiting gas compositions for the base model have been averaged over time and validated with experimental data and compared to the exiting results for the different parameter models. An extensive study is also carried out which considers the variation of different parameters such as bed temperatures, bed height, bed material, heat transfer coefficients, and devolatilization models influenced the gasification processes in different ways. Such an extensive parametric study has yet to be carried out for an Eulerian-Eulerian coal gasification model. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1023029
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 5959–5974[article] Parametric study of gasification processes in a BFB coal gasifier [texte imprimé] / L. M. Armstrong, Auteur ; S. Gu, Auteur ; K. H. Luo, Auteur . - 2011 . - pp. 5959–5974.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 5959–5974
Mots-clés : Gasification processes Résumé : An Eulerian-Eulerian computational fluid dynamics (CFD) model of the gasification processes in a coal bubbling fluidized bed (BFB) is presented based on the experimental setup taken from the literature. The base model is modified to account for different parameter changes in the model setup. The exiting gas compositions for the base model have been averaged over time and validated with experimental data and compared to the exiting results for the different parameter models. An extensive study is also carried out which considers the variation of different parameters such as bed temperatures, bed height, bed material, heat transfer coefficients, and devolatilization models influenced the gasification processes in different ways. Such an extensive parametric study has yet to be carried out for an Eulerian-Eulerian coal gasification model. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1023029 Exemplaires
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Titre : Accelerated deactivation of hydrotreating catalysts by coke deposition Type de document : texte imprimé Auteurs : Marcelo Edral Pacheco, Auteur ; Vera Maria Martins Salim, Auteur ; Jose Carlos Pinto, Auteur Année de publication : 2011 Article en page(s) : pp. 5975-5981 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Coke deposition Catalyst Hydrotreating Deactivation Résumé : Pilot plant experiments are designed to allow for evaluation of the impact caused by increasing the severity of key operation variables on deactivation of hydrotreating (HDT) catalysts, through accelerated runs performed in short periods of time. One of the main aspects of this work is the use of a kinetic approach in order to observe the impact of accelerated deactivation conditions upon catalyst performances during hydrodesulfurization (HDS), hydrodenitrogenation (HDN), and aromatic hydrogenation (HDA) reactions. This approach allows for evaluation of catalyst deactivation for each of the analyzed reactions. Results obtained with a reference catalyst indicate that the proposed methodology is able to deactivate the catalyst effectively, leading to proper representation of actual industrial deactivation at the end of a catalyst life cycle. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158894
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 5975-5981[article] Accelerated deactivation of hydrotreating catalysts by coke deposition [texte imprimé] / Marcelo Edral Pacheco, Auteur ; Vera Maria Martins Salim, Auteur ; Jose Carlos Pinto, Auteur . - 2011 . - pp. 5975-5981.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 5975-5981
Mots-clés : Coke deposition Catalyst Hydrotreating Deactivation Résumé : Pilot plant experiments are designed to allow for evaluation of the impact caused by increasing the severity of key operation variables on deactivation of hydrotreating (HDT) catalysts, through accelerated runs performed in short periods of time. One of the main aspects of this work is the use of a kinetic approach in order to observe the impact of accelerated deactivation conditions upon catalyst performances during hydrodesulfurization (HDS), hydrodenitrogenation (HDN), and aromatic hydrogenation (HDA) reactions. This approach allows for evaluation of catalyst deactivation for each of the analyzed reactions. Results obtained with a reference catalyst indicate that the proposed methodology is able to deactivate the catalyst effectively, leading to proper representation of actual industrial deactivation at the end of a catalyst life cycle. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158894 Exemplaires
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Titre : Combined in situ monitoring method for analysis and optimization of the lithiation-fluoroacetylation of N-(4-chlorophenyl)-pivalamide Type de document : texte imprimé Auteurs : Tamas A. Godany, Auteur ; Yorck-Michael Neuhold, Auteur ; Konrad Hungerbühler, Auteur Année de publication : 2011 Article en page(s) : pp. 5982-5991 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Optimization Surveillance In situ Résumé : Lithiation-fluoroacetylation of N-(4-chlorophenyl)-pivalamide (NCP) is a key step in the synthesis of a potent inhibitor of the HIV type 1 reverse transcriptase. The reaction comprises a heterogeneous lithiation step catalyzed by the solvent, fluoroacetylation with ethyl-trifluoroacetate (TFAEt), and hydrolysis. We investigate the reaction in our in-house developed small-scale low-temperature reaction calorimeter (CRC.v6 LT) employing in situ monitoring methods, such as reaction calorimetry, in situ spectroscopy (ATR FT-IR and UV/vis), and endoscopy, complemented by off-line GC/FID and GC/MS. The dynamic behavior of the reaction steps including end point prediction/detection is discussed, giving insights into a possible reaction mechanism and optimized reaction conditions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158895
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 5982-5991[article] Combined in situ monitoring method for analysis and optimization of the lithiation-fluoroacetylation of N-(4-chlorophenyl)-pivalamide [texte imprimé] / Tamas A. Godany, Auteur ; Yorck-Michael Neuhold, Auteur ; Konrad Hungerbühler, Auteur . - 2011 . - pp. 5982-5991.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 5982-5991
Mots-clés : Optimization Surveillance In situ Résumé : Lithiation-fluoroacetylation of N-(4-chlorophenyl)-pivalamide (NCP) is a key step in the synthesis of a potent inhibitor of the HIV type 1 reverse transcriptase. The reaction comprises a heterogeneous lithiation step catalyzed by the solvent, fluoroacetylation with ethyl-trifluoroacetate (TFAEt), and hydrolysis. We investigate the reaction in our in-house developed small-scale low-temperature reaction calorimeter (CRC.v6 LT) employing in situ monitoring methods, such as reaction calorimetry, in situ spectroscopy (ATR FT-IR and UV/vis), and endoscopy, complemented by off-line GC/FID and GC/MS. The dynamic behavior of the reaction steps including end point prediction/detection is discussed, giving insights into a possible reaction mechanism and optimized reaction conditions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158895 Exemplaires
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Titre : Periodic switching of monomer additions for controlling the compositions and microstructures of segmented and random ethylene-propylene copolymers in polypropylene in-reactor alloys Type de document : texte imprimé Auteurs : Zhou Tian, Auteur ; Xue-Ping Gu, Auteur ; Gang-Liang Wu, Auteur Année de publication : 2011 Article en page(s) : pp. 5992-5999 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Reactor Microstructure Résumé : This work aims at shading fundamental insights into mechanisms that dictate the composition and microstructure of polypropylene/poly(ethylene-co-propylene) (PP/EPR) in-reactor alloys produced by the multizone circulating reactor (MZCR) technology, a novel one for polyolefin production. For this purpose, this technology is simulated by a batch process with periodic switching of monomer additions. An increase in the switch frequency leads to a decrease in the fraction of ethylene/propylene random (amorphous) copolymers denoted as EPR and an increase in the fraction and the length of PP segments of ethylene/ propylene segmented (partially crystalline) copolymers denoted as EPS. Concomitantly, the size of the dispersed phase domains (EPR) decreases, and its size distribution becomes more uniform as a result of the decrease in the fraction of the EPR and the increase in that of the EPS which acts as a compatibilizer for PP/EPR in-reactor blends. Mechanical properties of the PP/EPR in-reactor blends are also discussed. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158896
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 5992-5999[article] Periodic switching of monomer additions for controlling the compositions and microstructures of segmented and random ethylene-propylene copolymers in polypropylene in-reactor alloys [texte imprimé] / Zhou Tian, Auteur ; Xue-Ping Gu, Auteur ; Gang-Liang Wu, Auteur . - 2011 . - pp. 5992-5999.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 5992-5999
Mots-clés : Reactor Microstructure Résumé : This work aims at shading fundamental insights into mechanisms that dictate the composition and microstructure of polypropylene/poly(ethylene-co-propylene) (PP/EPR) in-reactor alloys produced by the multizone circulating reactor (MZCR) technology, a novel one for polyolefin production. For this purpose, this technology is simulated by a batch process with periodic switching of monomer additions. An increase in the switch frequency leads to a decrease in the fraction of ethylene/propylene random (amorphous) copolymers denoted as EPR and an increase in the fraction and the length of PP segments of ethylene/ propylene segmented (partially crystalline) copolymers denoted as EPS. Concomitantly, the size of the dispersed phase domains (EPR) decreases, and its size distribution becomes more uniform as a result of the decrease in the fraction of the EPR and the increase in that of the EPS which acts as a compatibilizer for PP/EPR in-reactor blends. Mechanical properties of the PP/EPR in-reactor blends are also discussed. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158896 Exemplaires
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Titre : Photocatalytic membrane contactors for water treatment Type de document : texte imprimé Auteurs : Izumi Kumakiri, Auteur ; Spyros Diplas, Auteur ; Christian Simon, Auteur Année de publication : 2011 Article en page(s) : pp. 6000–600 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Water treatment Catalytic membrane Résumé : A three-phase catalytic membrane contactor (CMC) was applied in the photocatalytic degradation of organic substances in water. Particles of commercial TiO2 (P25 and ST01) were deposited on porous ceramic materials. Platinum was deposited onto TiO2 by the photoreduction method. The activity of the photo-CMC was studied with respect to removing from water model contaminants such as formic acid, oxalic acid, and humic acid. The influence of contacting nitrogen and oxygen with water through the membrane on the efficiency of the removal of those contaminants was investigated. The highest degradation rate was observed under UV (black light) irradiation with simultaneous oxygen supply. A combination of Pt with a photocatalyst improved the lifetime of Pt, as the photocatalysis maintains Pt in the metallic state by its reductive action and prevents Pt poisoning due to the generation of reactive oxygen species. No membrane fouling was observed under the conditions studied. The initial catalytic activity was preserved during several months of the tests and several months of storage in air. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102470f
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6000–600[article] Photocatalytic membrane contactors for water treatment [texte imprimé] / Izumi Kumakiri, Auteur ; Spyros Diplas, Auteur ; Christian Simon, Auteur . - 2011 . - pp. 6000–600.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6000–600
Mots-clés : Water treatment Catalytic membrane Résumé : A three-phase catalytic membrane contactor (CMC) was applied in the photocatalytic degradation of organic substances in water. Particles of commercial TiO2 (P25 and ST01) were deposited on porous ceramic materials. Platinum was deposited onto TiO2 by the photoreduction method. The activity of the photo-CMC was studied with respect to removing from water model contaminants such as formic acid, oxalic acid, and humic acid. The influence of contacting nitrogen and oxygen with water through the membrane on the efficiency of the removal of those contaminants was investigated. The highest degradation rate was observed under UV (black light) irradiation with simultaneous oxygen supply. A combination of Pt with a photocatalyst improved the lifetime of Pt, as the photocatalysis maintains Pt in the metallic state by its reductive action and prevents Pt poisoning due to the generation of reactive oxygen species. No membrane fouling was observed under the conditions studied. The initial catalytic activity was preserved during several months of the tests and several months of storage in air. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102470f Exemplaires
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Titre : Analysis of the autoignition process under the industrial partial oxidation conditions using detailed kinetic modeling Type de document : texte imprimé Auteurs : Yefei Liu, Auteur ; Tiefeng Wang, Auteur Année de publication : 2011 Article en page(s) : pp. 6009–6016 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Autoignition process Résumé : In the noncatalytic partial oxidation process, autoignition of the heated premixed combustible gases is a major source of reactor damage, unstable operation, and even explosion accidents. The knowledge of the autoignition behavior is of great importance to risk assessment and loss prevention in the partial oxidation reactors. The large experimental effort could be reduced if a reliable modeling procedure is available to identify the safe operating conditions. In this work the reliability of the detailed kinetic modeling method was investigated by comparing the simulated results with the experimental data reported in the literatures. It was found that the USC II mechanism gave the best predictions on the ignition delay times for the methane/air mixtures with equivalence ratios of 3.33 and 6.67. This mechanism was used to extrapolate the ignition delay times in the industrial partial oxidation process. The effects of initial temperature and equivalence ratio on ignition delay times were also investigated. The species concentration profiles were analyzed to understand the underlying ignition chemistry. The sensitivity analysis was carried out for the identification of the main reactions affecting the autoignition process. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102485v
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6009–6016[article] Analysis of the autoignition process under the industrial partial oxidation conditions using detailed kinetic modeling [texte imprimé] / Yefei Liu, Auteur ; Tiefeng Wang, Auteur . - 2011 . - pp. 6009–6016.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6009–6016
Mots-clés : Autoignition process Résumé : In the noncatalytic partial oxidation process, autoignition of the heated premixed combustible gases is a major source of reactor damage, unstable operation, and even explosion accidents. The knowledge of the autoignition behavior is of great importance to risk assessment and loss prevention in the partial oxidation reactors. The large experimental effort could be reduced if a reliable modeling procedure is available to identify the safe operating conditions. In this work the reliability of the detailed kinetic modeling method was investigated by comparing the simulated results with the experimental data reported in the literatures. It was found that the USC II mechanism gave the best predictions on the ignition delay times for the methane/air mixtures with equivalence ratios of 3.33 and 6.67. This mechanism was used to extrapolate the ignition delay times in the industrial partial oxidation process. The effects of initial temperature and equivalence ratio on ignition delay times were also investigated. The species concentration profiles were analyzed to understand the underlying ignition chemistry. The sensitivity analysis was carried out for the identification of the main reactions affecting the autoignition process. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102485v Exemplaires
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Titre : Kinetics and mechanism study of Low-temperature selective catalytic reduction of NO with urea supported on pitch-based spherical activated carbon Type de document : texte imprimé Auteurs : Zhi Wang, Auteur ; Yanli Wang, Auteur ; Donghui Long, Auteur Année de publication : 2011 Article en page(s) : pp. 6017–6027 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Kinetics Mechanism Catalytic reduction Résumé : The kinetics and mechanism of selective catalytic reduction (SCR) of NO with urea supported on pitch-based spherical activated carbons (PSACs) were studied at low temperatures. NO oxidation to NO2 catalyzed by the 0.5−0.8 nm micropores in PSACs was found to be the rate-limiting step in urea−SCR reaction, which was confirmed by both the apparent activation energy calculations and the kinetics results of urea−SCR reaction and NO oxidation on PSAC. These two reactions gave very similar negative apparent activation energies (−16.5 kJ/mol for urea−SCR reaction and −15.2 kJ/mol for NO oxidation), indicating that the adsorption of reactants on PSAC is of key importance in these two reactions. Moreover, these two reactions were both approximately first-order with respect to NO and one-half order with respect to O2. It was found that NO3 from the disproportionation of the produced NO2 was quickly reduced by supported urea into N2. After the complete consumption of supported urea, NO2 started to release, and the carbon surface was gradually oxidized by adsorbed NOx species. NO3 was found to be stably adsorbed on the oxidized carbon surface. On the basis of the results obtained, a reaction mechanism of low-temperature urea-SCR reaction on PSAC was proposed and discussed. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102506q
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6017–6027[article] Kinetics and mechanism study of Low-temperature selective catalytic reduction of NO with urea supported on pitch-based spherical activated carbon [texte imprimé] / Zhi Wang, Auteur ; Yanli Wang, Auteur ; Donghui Long, Auteur . - 2011 . - pp. 6017–6027.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6017–6027
Mots-clés : Kinetics Mechanism Catalytic reduction Résumé : The kinetics and mechanism of selective catalytic reduction (SCR) of NO with urea supported on pitch-based spherical activated carbons (PSACs) were studied at low temperatures. NO oxidation to NO2 catalyzed by the 0.5−0.8 nm micropores in PSACs was found to be the rate-limiting step in urea−SCR reaction, which was confirmed by both the apparent activation energy calculations and the kinetics results of urea−SCR reaction and NO oxidation on PSAC. These two reactions gave very similar negative apparent activation energies (−16.5 kJ/mol for urea−SCR reaction and −15.2 kJ/mol for NO oxidation), indicating that the adsorption of reactants on PSAC is of key importance in these two reactions. Moreover, these two reactions were both approximately first-order with respect to NO and one-half order with respect to O2. It was found that NO3 from the disproportionation of the produced NO2 was quickly reduced by supported urea into N2. After the complete consumption of supported urea, NO2 started to release, and the carbon surface was gradually oxidized by adsorbed NOx species. NO3 was found to be stably adsorbed on the oxidized carbon surface. On the basis of the results obtained, a reaction mechanism of low-temperature urea-SCR reaction on PSAC was proposed and discussed. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102506q Exemplaires
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Titre : Catalytic thermochemical conversion of glycerol to simple and polyhydric alcohols using raney nickel catalyst Type de document : texte imprimé Auteurs : Randy L. Maglinao, Auteur ; B. Brian He, Auteur Année de publication : 2011 Article en page(s) : pp. 6028-6033 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Catalyst Raney nickel Catalytic reaction Résumé : The crude glycerol from biodiesel production possesses low economic values and alternative wavs of converting it to valuable chemicals are needed to sustain the biodiesel industry. This study aimed to investigate the production of primary alcohols and propylene glycol from glycerol through a catalytic thermochemical process without an external supply of hydrogen. The effects of reaction time, water to glycerol ratio, and doses of catalyst on glycerol conversion and alcohol yields were investigated using a batch pressure reactor and Raney nickel catalyst The presence of alcohols and gases in the products confirmed that hydrogen was produced and was utilized in the formation of propylene glycol through hydrogenolysis. Ethanol and propylene glycol yields of up to 10.4±0.2 and 33.2±1.4 mol %, respectively, were observed. It was also concluded that ethanol is formed through hydrogenolysis of propylene glycol and its yield improves at extended reaction time and increased initial water content of the feed. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158900
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6028-6033[article] Catalytic thermochemical conversion of glycerol to simple and polyhydric alcohols using raney nickel catalyst [texte imprimé] / Randy L. Maglinao, Auteur ; B. Brian He, Auteur . - 2011 . - pp. 6028-6033.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6028-6033
Mots-clés : Catalyst Raney nickel Catalytic reaction Résumé : The crude glycerol from biodiesel production possesses low economic values and alternative wavs of converting it to valuable chemicals are needed to sustain the biodiesel industry. This study aimed to investigate the production of primary alcohols and propylene glycol from glycerol through a catalytic thermochemical process without an external supply of hydrogen. The effects of reaction time, water to glycerol ratio, and doses of catalyst on glycerol conversion and alcohol yields were investigated using a batch pressure reactor and Raney nickel catalyst The presence of alcohols and gases in the products confirmed that hydrogen was produced and was utilized in the formation of propylene glycol through hydrogenolysis. Ethanol and propylene glycol yields of up to 10.4±0.2 and 33.2±1.4 mol %, respectively, were observed. It was also concluded that ethanol is formed through hydrogenolysis of propylene glycol and its yield improves at extended reaction time and increased initial water content of the feed. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158900 Exemplaires
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Titre : Experimental study of HCl capture using CaO sorbents : activation, deactivation, reactivation, and ionic transfer mechanism Type de document : texte imprimé Auteurs : Zhenchao Sun, Auteur ; Fu-Chen Yu, Auteur ; Fanxing Li, Auteur Année de publication : 2011 Article en page(s) : pp. 6034-6043 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Deactivation Activation Résumé : Experimental study of dry HCl removal from synthesis gas or flue gas using CaO sorbents, in the context of CaO-based chemical looping processes, is reported. The study was first conducted in a TGA and a fixed-bed reactor to test the effects of chloridation temperature, sorbent particle size, HCl concentration, and space velocity on the HCl capture capacity. The chloridation reactivity deterioration of CaO sorbents with multicyclic carbonation-calcination reaction (CCR) and/or at high calcination temperatures, which are of notable relevance to the CaO-based chemical looping processes, was also investigated. In addition, precipitation (activation) and hydration (reactivation) were used to enhance initial sorbent reactivity and to reactivate the deactivated sorbents, respectively. The effects of deactivation, activation, and reactivation were explained by the morphological property change of the sorbents. To further elucidate the solid phase reaction mechanism of CaO and HCl, ionic transfer behavior during chloridation reaction was characterized using an inert marker experiment Through the present work, the performance of CaO sorbents in HCl capture, deactivation of the sorbents by high-temperature calcination and multiple CCR cycles, sorbent activation and reactivation strategies, and the corresponding reaction mechanisms are determined. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158901
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6034-6043[article] Experimental study of HCl capture using CaO sorbents : activation, deactivation, reactivation, and ionic transfer mechanism [texte imprimé] / Zhenchao Sun, Auteur ; Fu-Chen Yu, Auteur ; Fanxing Li, Auteur . - 2011 . - pp. 6034-6043.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6034-6043
Mots-clés : Deactivation Activation Résumé : Experimental study of dry HCl removal from synthesis gas or flue gas using CaO sorbents, in the context of CaO-based chemical looping processes, is reported. The study was first conducted in a TGA and a fixed-bed reactor to test the effects of chloridation temperature, sorbent particle size, HCl concentration, and space velocity on the HCl capture capacity. The chloridation reactivity deterioration of CaO sorbents with multicyclic carbonation-calcination reaction (CCR) and/or at high calcination temperatures, which are of notable relevance to the CaO-based chemical looping processes, was also investigated. In addition, precipitation (activation) and hydration (reactivation) were used to enhance initial sorbent reactivity and to reactivate the deactivated sorbents, respectively. The effects of deactivation, activation, and reactivation were explained by the morphological property change of the sorbents. To further elucidate the solid phase reaction mechanism of CaO and HCl, ionic transfer behavior during chloridation reaction was characterized using an inert marker experiment Through the present work, the performance of CaO sorbents in HCl capture, deactivation of the sorbents by high-temperature calcination and multiple CCR cycles, sorbent activation and reactivation strategies, and the corresponding reaction mechanisms are determined. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158901 Exemplaires
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Titre : Modeling and simulation of an industrial ethylene oxide (EO) reactor using artificial neural networks (ANN) Type de document : texte imprimé Auteurs : M. R. Rahimpour, Auteur ; M. Shayanmehr, Auteur ; M. Nazari, Auteur Année de publication : 2011 Article en page(s) : pp. 6044–6052 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Ethylene oxide Artificial neural networks Résumé : In the present work, a one-dimensional heterogeneous model was used for dynamic simulation of an industrial fixed-bed catalytic ethylene oxide (EO) reactor in the presence of long-term catalyst deactivation. In order to determine the level of optimum ethylene dichloride (EDC), a multilayer perceptron (MLP) neural network was used. In addition, the effect of inlet gas velocity on EO mole fraction of gas and solid phases was investigated. The model validation was carried out by comparison of model results with corresponding industrial conditions and over a period of three operating years. A good agreement was found between the simulation results of the dynamic model and historical process data. The error of simulation was found to be less than 5%. The results of the artificial neural network (ANN) modeling showed that the maximum selectivity occurs in the range of 0.37–0.42 ppm of EDC. Also, it was observed that with decrease of gas velocity the difference between the EO mole fraction of gas phase and solid phase increases. This behavior was attributed to the distinct resistances of kinetically controlled and the mass transfer resistance of gas film around the catalyst pellets. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101319d
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6044–6052[article] Modeling and simulation of an industrial ethylene oxide (EO) reactor using artificial neural networks (ANN) [texte imprimé] / M. R. Rahimpour, Auteur ; M. Shayanmehr, Auteur ; M. Nazari, Auteur . - 2011 . - pp. 6044–6052.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6044–6052
Mots-clés : Ethylene oxide Artificial neural networks Résumé : In the present work, a one-dimensional heterogeneous model was used for dynamic simulation of an industrial fixed-bed catalytic ethylene oxide (EO) reactor in the presence of long-term catalyst deactivation. In order to determine the level of optimum ethylene dichloride (EDC), a multilayer perceptron (MLP) neural network was used. In addition, the effect of inlet gas velocity on EO mole fraction of gas and solid phases was investigated. The model validation was carried out by comparison of model results with corresponding industrial conditions and over a period of three operating years. A good agreement was found between the simulation results of the dynamic model and historical process data. The error of simulation was found to be less than 5%. The results of the artificial neural network (ANN) modeling showed that the maximum selectivity occurs in the range of 0.37–0.42 ppm of EDC. Also, it was observed that with decrease of gas velocity the difference between the EO mole fraction of gas phase and solid phase increases. This behavior was attributed to the distinct resistances of kinetically controlled and the mass transfer resistance of gas film around the catalyst pellets. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101319d Exemplaires
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Titre : Application of technical kinetics for macroscopic analysis of ozone synthesis process Type de document : texte imprimé Auteurs : Sławomir Jodzis, Auteur Année de publication : 2011 Article en page(s) : pp. 6053-6060 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Kinetics Résumé : The method of measuring the technical rate of ozone synthesis process, and the manner of utilizing the process rate for determining the boundary ozone contents in the reacting system has been presented. On the basis of macroscopic analysis of the process the reason causing the obtaining of the ozone concentration lower than that theoretically possible, has been pointed out. It is shown that an increase in temperature in the discharge gap does not inhibit the ozone-forming rate. The decrease in ozone concentration observed is a result of ozone intensive decomposition. However, under typical conditions of the process, the ozone decomposition is a result of the temperature in the microdischarge channels and not that of the gas or the cooling liquid. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158903
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6053-6060[article] Application of technical kinetics for macroscopic analysis of ozone synthesis process [texte imprimé] / Sławomir Jodzis, Auteur . - 2011 . - pp. 6053-6060.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6053-6060
Mots-clés : Kinetics Résumé : The method of measuring the technical rate of ozone synthesis process, and the manner of utilizing the process rate for determining the boundary ozone contents in the reacting system has been presented. On the basis of macroscopic analysis of the process the reason causing the obtaining of the ozone concentration lower than that theoretically possible, has been pointed out. It is shown that an increase in temperature in the discharge gap does not inhibit the ozone-forming rate. The decrease in ozone concentration observed is a result of ozone intensive decomposition. However, under typical conditions of the process, the ozone decomposition is a result of the temperature in the microdischarge channels and not that of the gas or the cooling liquid. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158903 Exemplaires
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Titre : Continuous polyolefin cracking on an HZSM-5 zeolite catalyst in a conical spouted bed reactor Type de document : texte imprimé Auteurs : Gorka Elordi, Auteur ; Martin Olazar, Auteur ; Gartzen Lopez, Auteur Année de publication : 2011 Article en page(s) : pp. 6061-6070 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Reactor Fluidization Spouted bed Catalyst Zeolite Cracking Résumé : The effect of operating conditions on product yields and compositions has been studied in the catalytic cracking of polyolefins (high- and low-density polyethylene and polypropylene) in a conical spouted bed reactor. The catalyst has been prepared by agglomerating an HZSM-5 zeolite (SiO2/Al2O3 = 30) with bentonite and alumina. The study has been carried out in continuous mode, in the 450-570 °C range, with polyolefin flow rates between 1 and 2 g min-1 and feeding up to 1 kg of polyolefin into a 30 g catalyst bed. The result is an excellent performance of the reactor-catalyst pairing for continuous catalytic pyrolysis, given that the yields obtained in the pyrolysis of high-density polyethylene at 500 °C without defluidization problems and very low catalyst deactivation are as follows: 60 wt % C2-C4 olefins, 15 wt % nonaromatic C5-C11, hydrocarbons, 10 wt % single-ring aromatics, and 14 wt % C4- alkanes. Only small differences are observed in the pyrolysis of the different polyolefins. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158904
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6061-6070[article] Continuous polyolefin cracking on an HZSM-5 zeolite catalyst in a conical spouted bed reactor [texte imprimé] / Gorka Elordi, Auteur ; Martin Olazar, Auteur ; Gartzen Lopez, Auteur . - 2011 . - pp. 6061-6070.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6061-6070
Mots-clés : Reactor Fluidization Spouted bed Catalyst Zeolite Cracking Résumé : The effect of operating conditions on product yields and compositions has been studied in the catalytic cracking of polyolefins (high- and low-density polyethylene and polypropylene) in a conical spouted bed reactor. The catalyst has been prepared by agglomerating an HZSM-5 zeolite (SiO2/Al2O3 = 30) with bentonite and alumina. The study has been carried out in continuous mode, in the 450-570 °C range, with polyolefin flow rates between 1 and 2 g min-1 and feeding up to 1 kg of polyolefin into a 30 g catalyst bed. The result is an excellent performance of the reactor-catalyst pairing for continuous catalytic pyrolysis, given that the yields obtained in the pyrolysis of high-density polyethylene at 500 °C without defluidization problems and very low catalyst deactivation are as follows: 60 wt % C2-C4 olefins, 15 wt % nonaromatic C5-C11, hydrocarbons, 10 wt % single-ring aromatics, and 14 wt % C4- alkanes. Only small differences are observed in the pyrolysis of the different polyolefins. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158904 Exemplaires
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Titre : Texture-based foam segmentation and analysis Type de document : texte imprimé Auteurs : Wei Wang, Auteur ; Xiaolei Huang, Auteur ; Ali Esmaili, Auteur Année de publication : 2011 Article en page(s) : pp. 6071-6081 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Foam Résumé : A variety of polymers or surfactant mixtures or aeration of a number of liquids could generate mixtures of liquid and foam. Therefore, characterizing the properties ofliquid/foam mixtures has important applications in the chemical process industry. The lack of a robust automated method for characterization within limited time and with high accuracy, however, has made this task difficult. In this work, we propose a new method based on image analysis for quantifying the geometric and statistical properties of such liquid/foam mixtures using images captured by an optical camera. The method can reliably achieve automated segmentation of liquid and foam layers. It can also find the boundaries of individual bubbles in the foam layer. At first, the region of interest, the foam region, is segmented from the input raw image. Then, the foam region is partitioned into two types of subregions, namely, loose foam or dense foam, according to local texture feature analysis. In the next step, to segment bubbles within the foam to obtain quantitative characterization, we apply two image processing algorithms, namely, Canny edge detection and K-means clustering, each specific to a different type of foam (loose or dense). The results show that the proposed automated segmentation and characterization method is robust and applicable to the processing of foam/liquid mixtures under many conditions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158905
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6071-6081[article] Texture-based foam segmentation and analysis [texte imprimé] / Wei Wang, Auteur ; Xiaolei Huang, Auteur ; Ali Esmaili, Auteur . - 2011 . - pp. 6071-6081.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6071-6081
Mots-clés : Foam Résumé : A variety of polymers or surfactant mixtures or aeration of a number of liquids could generate mixtures of liquid and foam. Therefore, characterizing the properties ofliquid/foam mixtures has important applications in the chemical process industry. The lack of a robust automated method for characterization within limited time and with high accuracy, however, has made this task difficult. In this work, we propose a new method based on image analysis for quantifying the geometric and statistical properties of such liquid/foam mixtures using images captured by an optical camera. The method can reliably achieve automated segmentation of liquid and foam layers. It can also find the boundaries of individual bubbles in the foam layer. At first, the region of interest, the foam region, is segmented from the input raw image. Then, the foam region is partitioned into two types of subregions, namely, loose foam or dense foam, according to local texture feature analysis. In the next step, to segment bubbles within the foam to obtain quantitative characterization, we apply two image processing algorithms, namely, Canny edge detection and K-means clustering, each specific to a different type of foam (loose or dense). The results show that the proposed automated segmentation and characterization method is robust and applicable to the processing of foam/liquid mixtures under many conditions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158905 Exemplaires
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Titre : Adsorption and inhibitory mechanism of 1H-1,2,4-triazol-l-yl-methyl-2-(4-chlorophenoxy) acetate on corrosion of mild steel in acidic solution Type de document : texte imprimé Auteurs : Zhihua Tao, Auteur ; Shengtao Zhang, Auteur ; Weihua Li, Auteur Année de publication : 2011 Article en page(s) : pp. 6082-6088 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Acidic solution Mild steel Corrosion Adsorption Résumé : The triazole-acetate derivative TMCA was synthesized and its inhibiting action on the corrosion of mild steel in sulphuric acid was investigated by means of weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and scanning electronic microscope (SEM). The potentiodynamic polarization measurements show that the TMCA acts essentially as a mixed-type inhibitor, and EIS confirmed that changes in the impedance parameters were due to surface adsorption. The inhibition efficiencies (IE%) obtained from weight loss measurement and electrochemical tests were in good agreement. Substitutional inhibition mechanism of mild steel was established according to the fitted results at different temperatures. The number of water molecules (X) replaced by a molecule of organic adsorbate was determined from the different substitutional adsorption isotherms applied to the data obtained from weight loss experiments. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158906
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6082-6088[article] Adsorption and inhibitory mechanism of 1H-1,2,4-triazol-l-yl-methyl-2-(4-chlorophenoxy) acetate on corrosion of mild steel in acidic solution [texte imprimé] / Zhihua Tao, Auteur ; Shengtao Zhang, Auteur ; Weihua Li, Auteur . - 2011 . - pp. 6082-6088.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6082-6088
Mots-clés : Acidic solution Mild steel Corrosion Adsorption Résumé : The triazole-acetate derivative TMCA was synthesized and its inhibiting action on the corrosion of mild steel in sulphuric acid was investigated by means of weight loss, potentiodynamic polarization, electrochemical impedance spectroscopy (EIS), and scanning electronic microscope (SEM). The potentiodynamic polarization measurements show that the TMCA acts essentially as a mixed-type inhibitor, and EIS confirmed that changes in the impedance parameters were due to surface adsorption. The inhibition efficiencies (IE%) obtained from weight loss measurement and electrochemical tests were in good agreement. Substitutional inhibition mechanism of mild steel was established according to the fitted results at different temperatures. The number of water molecules (X) replaced by a molecule of organic adsorbate was determined from the different substitutional adsorption isotherms applied to the data obtained from weight loss experiments. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158906 Exemplaires
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Titre : Predicting the effect of the homogenization pressure on emulsion drop-size distributions Type de document : texte imprimé Auteurs : Neha B. Raikar, Auteur ; Surita R. Bhatia, Auteur ; Michael F. Malone, Auteur Année de publication : 2011 Article en page(s) : pp. 6089–6100 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Homogenization pressure Emulsion Résumé : We have previously developed a population balance equation (PBE) model for emulsion drop breakage in a high-pressure homogenizer that incorporated multiple-drop formation within two mechanisms of turbulent drop breakage. The model was found to satisfactorily predict the effects of formulation variables on the drop-size distribution, but the model was not extensible to a range of homogenization pressures. The objective of this paper is to determine the additional model elements necessary to obtain acceptable predictions over a wide range of pressures. The most significant improvements were obtained by increasing the number of daughter drops formed upon breakage from 20 to 150 drops and by introducing a maximum stable diameter, below which drops could not break. Smaller improvements were obtained by introducing terms that describe the loss of energy available for drop breakage due to thermal heating of the sample and homogenizer and by extending the model to account for the effects of surfactant adsorption and deficiency on the interfacial tension. The simultaneous implementation of all five enhancements was shown to produce a 62% improvement over the previous model, as measured by a least-squares objective based on the difference between the measured and predicted drop-size distributions over five homogenization passes and five pressures in the range 250−1250 bar. The resulting model was also validated over a range of oil and surfactant concentrations and shown to provide satisfactory predictions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101818h
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6089–6100[article] Predicting the effect of the homogenization pressure on emulsion drop-size distributions [texte imprimé] / Neha B. Raikar, Auteur ; Surita R. Bhatia, Auteur ; Michael F. Malone, Auteur . - 2011 . - pp. 6089–6100.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6089–6100
Mots-clés : Homogenization pressure Emulsion Résumé : We have previously developed a population balance equation (PBE) model for emulsion drop breakage in a high-pressure homogenizer that incorporated multiple-drop formation within two mechanisms of turbulent drop breakage. The model was found to satisfactorily predict the effects of formulation variables on the drop-size distribution, but the model was not extensible to a range of homogenization pressures. The objective of this paper is to determine the additional model elements necessary to obtain acceptable predictions over a wide range of pressures. The most significant improvements were obtained by increasing the number of daughter drops formed upon breakage from 20 to 150 drops and by introducing a maximum stable diameter, below which drops could not break. Smaller improvements were obtained by introducing terms that describe the loss of energy available for drop breakage due to thermal heating of the sample and homogenizer and by extending the model to account for the effects of surfactant adsorption and deficiency on the interfacial tension. The simultaneous implementation of all five enhancements was shown to produce a 62% improvement over the previous model, as measured by a least-squares objective based on the difference between the measured and predicted drop-size distributions over five homogenization passes and five pressures in the range 250−1250 bar. The resulting model was also validated over a range of oil and surfactant concentrations and shown to provide satisfactory predictions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101818h Exemplaires
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Titre : Synthesis of bimodal porous titania beads and their potential in liquid chromatography Type de document : texte imprimé Auteurs : Kai-Feng Du, Auteur ; Min Yan, Auteur ; Hang Song, Auteur Année de publication : 2011 Article en page(s) : pp. 6101-6108 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Liquid chromatography Résumé : Bimodal porous titania beads were synthesized from titania nanocrystals of about 34 nm by a method that combines particles agglomeration and sol-gel templating process. The structure properties of porous titania beads were investigated, and the results indicated that the porous titania beads in size of about 15 μm are pure anatase phase and featured by two types of pores with macropores centered at about 200 nm and mesopores smaller than 10 nm. The bimodal pore structure is attributed to hard aggregates of titania particles with different size. In particular, the larger titania nanocrystals agglomerate into macropores and the smaller ones from crystal growth of coated titania into mesopores. Finally, after cation modification, the bimodal porous adsorbents (BPA) were evaluated for investigating chromatographic performance and compared to microporous ones (MPA). It was observed that static and dynamic adsorption capacities of cytochrome C on BPA are both larger than that on MPA. Moreover, the BPApacked column shows better column efficiency than the MPA packed one in test flow rates. Therefore, we demonstrated that the BPA occupies more advantages over the other one and is expected for potential application in chromatography. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158908
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6101-6108[article] Synthesis of bimodal porous titania beads and their potential in liquid chromatography [texte imprimé] / Kai-Feng Du, Auteur ; Min Yan, Auteur ; Hang Song, Auteur . - 2011 . - pp. 6101-6108.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6101-6108
Mots-clés : Liquid chromatography Résumé : Bimodal porous titania beads were synthesized from titania nanocrystals of about 34 nm by a method that combines particles agglomeration and sol-gel templating process. The structure properties of porous titania beads were investigated, and the results indicated that the porous titania beads in size of about 15 μm are pure anatase phase and featured by two types of pores with macropores centered at about 200 nm and mesopores smaller than 10 nm. The bimodal pore structure is attributed to hard aggregates of titania particles with different size. In particular, the larger titania nanocrystals agglomerate into macropores and the smaller ones from crystal growth of coated titania into mesopores. Finally, after cation modification, the bimodal porous adsorbents (BPA) were evaluated for investigating chromatographic performance and compared to microporous ones (MPA). It was observed that static and dynamic adsorption capacities of cytochrome C on BPA are both larger than that on MPA. Moreover, the BPApacked column shows better column efficiency than the MPA packed one in test flow rates. Therefore, we demonstrated that the BPA occupies more advantages over the other one and is expected for potential application in chromatography. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158908 Exemplaires
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Titre : Immobilization of polymethyl methacrylate brushes on hydroxyapatite under molecular weight control Type de document : texte imprimé Auteurs : D. Tian, Auteur ; X. H. Chu, Auteur ; D. H. Yu, Auteur Année de publication : 2011 Article en page(s) : pp. 6109-6114 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Hydroxyapatite Immobilization Résumé : Polymethyl methacrylate (PMMA) brushes with a quantitative molecular weight (Mw) and low polydispersity index are synthesized via atom transfer radical polymerization and grafted onto the surfaces of hydroxyapatite (HA) that were modified with γ-methacryloxypropyl trimethoxysilane (MPTS). The structure and morphology of MPTS surface modified and furthermore PMMA grafted HA was mainly investigated by means of infrared spectrophotometry, X-ray diffraction, thermal gravimetric analysis, scanning electron microscope, and differential scanning calorimetry studies. It is found that polymer brushes are covalently attached to the HA surface under controlled Mw of PMMA segments without any structural deformation on the HA phase and exhibit grafting abilities for tuning properties of the composites. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158909
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6109-6114[article] Immobilization of polymethyl methacrylate brushes on hydroxyapatite under molecular weight control [texte imprimé] / D. Tian, Auteur ; X. H. Chu, Auteur ; D. H. Yu, Auteur . - 2011 . - pp. 6109-6114.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6109-6114
Mots-clés : Hydroxyapatite Immobilization Résumé : Polymethyl methacrylate (PMMA) brushes with a quantitative molecular weight (Mw) and low polydispersity index are synthesized via atom transfer radical polymerization and grafted onto the surfaces of hydroxyapatite (HA) that were modified with γ-methacryloxypropyl trimethoxysilane (MPTS). The structure and morphology of MPTS surface modified and furthermore PMMA grafted HA was mainly investigated by means of infrared spectrophotometry, X-ray diffraction, thermal gravimetric analysis, scanning electron microscope, and differential scanning calorimetry studies. It is found that polymer brushes are covalently attached to the HA surface under controlled Mw of PMMA segments without any structural deformation on the HA phase and exhibit grafting abilities for tuning properties of the composites. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158909 Exemplaires
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Titre : Effects of UV exposure and initiator concentration on the spatial variation of poly(glycidyl methacrylate) grafts on nonwoven fabrics Type de document : texte imprimé Auteurs : Yong Zheng, Auteur ; Patrick V. Gurgel, Auteur ; Ruben G. Carbonell, Auteur Année de publication : 2011 Article en page(s) : pp. 6115–6123 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Fibers of polypropylene nonwoven Résumé : This paper describes the spatial uniformity of grafted layers of poly(glycydyl methacrylate) on the fibers of polypropylene nonwoven fabrics, and how they depend on the UV pretreatment step, the adsorption of initiator (benzophenone) to the fiber surface, and the UV grafting step. UV light transmission inside the nonwoven fabrics was measured to determine the effect of light intensity variations during the pretreatment and grafting steps. The light intensity decay depends on the pore size of the fabric and the presence of solvents in the nonwoven fabric. The adsorption of benzophenone to the fiber surface is lower in regions of low light intensity, resulting in a spatial variation due to the UV pretreatment. The presence of solvents tends to reduce light intensity decay during the grafting step. The results of this paper indicate how to avoid spatial nonuniformities during grafting by controlling the reaction conditions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1021333
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6115–6123[article] Effects of UV exposure and initiator concentration on the spatial variation of poly(glycidyl methacrylate) grafts on nonwoven fabrics [texte imprimé] / Yong Zheng, Auteur ; Patrick V. Gurgel, Auteur ; Ruben G. Carbonell, Auteur . - 2011 . - pp. 6115–6123.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6115–6123
Mots-clés : Fibers of polypropylene nonwoven Résumé : This paper describes the spatial uniformity of grafted layers of poly(glycydyl methacrylate) on the fibers of polypropylene nonwoven fabrics, and how they depend on the UV pretreatment step, the adsorption of initiator (benzophenone) to the fiber surface, and the UV grafting step. UV light transmission inside the nonwoven fabrics was measured to determine the effect of light intensity variations during the pretreatment and grafting steps. The light intensity decay depends on the pore size of the fabric and the presence of solvents in the nonwoven fabric. The adsorption of benzophenone to the fiber surface is lower in regions of low light intensity, resulting in a spatial variation due to the UV pretreatment. The presence of solvents tends to reduce light intensity decay during the grafting step. The results of this paper indicate how to avoid spatial nonuniformities during grafting by controlling the reaction conditions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1021333 Exemplaires
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Titre : Improving flexibility of poly(l-lactide) by blending with poly(l-lactic acid) based poly(ester-urethane) : morphology, mechanical properties, and crystallization behaviors Type de document : texte imprimé Auteurs : Jian-Bing Zeng, Auteur ; Yi-Dong Li, Auteur ; Yi-Song He, Auteur Année de publication : 2011 Article en page(s) : pp. 6124–6131 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Crystallization Mechanical properties Morphology Flexibility Résumé : Poly(L-lactide) (PLLA) is one of the most promising biobased and biodegradable polymers. However, the lack of toughness restricts its application considerably. In the present study, PLLA was successfully toughened by blending with a poly(lactic acid) based poly(ester-urethane) (PEU), which contained poly(butylene succinate) as a flexible segment The tensile properties and notched Izod impact strength of PLLA and toughened PLLA were investigated. The flexibility of PLLA was considerably improved after introduction of PEU by the evidence of high strain and improved impact strength. The crystallization behavior was investigated by differential scanning calorimeter (DSC), polarized optical microscopy (POM), and wide-angle X-ray diffraction (WAXD). The glass transition temperature of toughened PLLA decreased with an increasing content of PEU, suggesting that the blends showed limited miscibility. POM observation showed that the crystallites of PEU uniformly distributed in the PLLA matrix after two-step crystallization at 120 and 60 °C. The results of WAXD suggest that the crystal structure of PLLA remained unchanged after blending with the PEU. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158911
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6124–6131[article] Improving flexibility of poly(l-lactide) by blending with poly(l-lactic acid) based poly(ester-urethane) : morphology, mechanical properties, and crystallization behaviors [texte imprimé] / Jian-Bing Zeng, Auteur ; Yi-Dong Li, Auteur ; Yi-Song He, Auteur . - 2011 . - pp. 6124–6131.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6124–6131
Mots-clés : Crystallization Mechanical properties Morphology Flexibility Résumé : Poly(L-lactide) (PLLA) is one of the most promising biobased and biodegradable polymers. However, the lack of toughness restricts its application considerably. In the present study, PLLA was successfully toughened by blending with a poly(lactic acid) based poly(ester-urethane) (PEU), which contained poly(butylene succinate) as a flexible segment The tensile properties and notched Izod impact strength of PLLA and toughened PLLA were investigated. The flexibility of PLLA was considerably improved after introduction of PEU by the evidence of high strain and improved impact strength. The crystallization behavior was investigated by differential scanning calorimeter (DSC), polarized optical microscopy (POM), and wide-angle X-ray diffraction (WAXD). The glass transition temperature of toughened PLLA decreased with an increasing content of PEU, suggesting that the blends showed limited miscibility. POM observation showed that the crystallites of PEU uniformly distributed in the PLLA matrix after two-step crystallization at 120 and 60 °C. The results of WAXD suggest that the crystal structure of PLLA remained unchanged after blending with the PEU. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158911 Exemplaires
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Titre : Effect of oxygen content on structures of graphite oxides Type de document : texte imprimé Auteurs : Hui Wang, Auteur ; Yun Hang Hu, Auteur Année de publication : 2011 Article en page(s) : pp. 6132-6137 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Oxygen content Résumé : Graphite oxide was synthesized by the oxidation of graphite via a modified Hummers approach. The oxygen content of graphite oxide was tuned by changing the oxidation time. The saturated ratio of oxygen to carbon is 0.47. Furthermore, the effect of oxygen content on the structures of graphite oxide was evaluated by using SEM, TEM, XRD, Raman, FTIR, TG, TPD-MS, and nitrogen adsorption. It was found that the types of functional groups in graphite oxides, which are epoxy, hydroxyl, and carboxyl groups, were independent of oxygen content. However, the interplanar space and BET surface area of graphite oxide linearly increased with increasing O/C ratio. Furthermore, the structure of graphite can be easily and remarkably disordered even by partial oxidation. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158912
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6132-6137[article] Effect of oxygen content on structures of graphite oxides [texte imprimé] / Hui Wang, Auteur ; Yun Hang Hu, Auteur . - 2011 . - pp. 6132-6137.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6132-6137
Mots-clés : Oxygen content Résumé : Graphite oxide was synthesized by the oxidation of graphite via a modified Hummers approach. The oxygen content of graphite oxide was tuned by changing the oxidation time. The saturated ratio of oxygen to carbon is 0.47. Furthermore, the effect of oxygen content on the structures of graphite oxide was evaluated by using SEM, TEM, XRD, Raman, FTIR, TG, TPD-MS, and nitrogen adsorption. It was found that the types of functional groups in graphite oxides, which are epoxy, hydroxyl, and carboxyl groups, were independent of oxygen content. However, the interplanar space and BET surface area of graphite oxide linearly increased with increasing O/C ratio. Furthermore, the structure of graphite can be easily and remarkably disordered even by partial oxidation. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158912 Exemplaires
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Titre : Wetting of TX-100 and igepal CO-630 surfactants on a PTFE surface Type de document : texte imprimé Auteurs : Nihar Ranjan Biswal, Auteur ; Santanu Paria, Auteur Année de publication : 2011 Article en page(s) : pp. 6138-6145 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Surfactant Wetting Résumé : Nonionic surfactants are advantageous in a diversified range of applications from household cleaners, laundry detergents, and shampoo to paints, coatings, and food emulsifiers because of their low CMC and surface tension values over the ionic surfactants. Nonionic surfactants, in general, are very useful in mixed surfactant systems because of their electrical neutrality. Among the similar class of nonionic surfactants, structural difference is important in the performance. In this study, we report on the adsorption and wetting behavior of two nonionic surfactants (TX-100 and Igepal CO-630) having the same head group but structurally different tail groups. The kinetics of adsorption follows a pseudo-second-order kinetic model and a Langmuir-type isotherm for both the surfactants. The change in contact angle with the concentration of surfactant follows a trend similar to that for adsorption onto a PTFE surface. At low surfactant concentration, Igepal CO-630 shows a slightly higher adsorption density and better wetting properties than TX-100. Both surfactants show lower adsorption densities at the PTFE-water interface than at the air-water interface. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158913
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6138-6145[article] Wetting of TX-100 and igepal CO-630 surfactants on a PTFE surface [texte imprimé] / Nihar Ranjan Biswal, Auteur ; Santanu Paria, Auteur . - 2011 . - pp. 6138-6145.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6138-6145
Mots-clés : Surfactant Wetting Résumé : Nonionic surfactants are advantageous in a diversified range of applications from household cleaners, laundry detergents, and shampoo to paints, coatings, and food emulsifiers because of their low CMC and surface tension values over the ionic surfactants. Nonionic surfactants, in general, are very useful in mixed surfactant systems because of their electrical neutrality. Among the similar class of nonionic surfactants, structural difference is important in the performance. In this study, we report on the adsorption and wetting behavior of two nonionic surfactants (TX-100 and Igepal CO-630) having the same head group but structurally different tail groups. The kinetics of adsorption follows a pseudo-second-order kinetic model and a Langmuir-type isotherm for both the surfactants. The change in contact angle with the concentration of surfactant follows a trend similar to that for adsorption onto a PTFE surface. At low surfactant concentration, Igepal CO-630 shows a slightly higher adsorption density and better wetting properties than TX-100. Both surfactants show lower adsorption densities at the PTFE-water interface than at the air-water interface. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158913 Exemplaires
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Titre : Detailed design of multiproduct batch plants considering production scheduling Type de document : texte imprimé Auteurs : Yanina Fumero, Auteur ; Gabriela Corsano, Auteur ; Jorge M. Montagna, Auteur Année de publication : 2011 Article en page(s) : pp. 6146-6160 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Scheduling Production Batchwise Design Résumé : Most previous approaches for the design of multiproduct batch plants have assumed the simplest scheduling policy. In order to simplify the formulation and take into account that many times demands are uncertain, they have used single product campaigns to determine the plant configuration and select the unit sizes. From the commercial point of view, this production mode is not realistic: for example, huge inventories should be kept to support this approach. However, when a stable context can be assured, the simultaneous resolution of design and a more detailed scheduling allows assessing different trade-offs. This article presents a new mixed integer linear programming (MILP) formulation assuming mixed product campaigns. Now, the composition and the sequence of the batches in the campaign must be determined as well as the assignment of batches to units when parallel units are used. Taking into account that the plant configuration is simultaneously obtained, the scheduling problem must be solved without knowing the number of available units and their sizes. Several examples are presented in order to show the performance of the proposed approach. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158914
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6146-6160[article] Detailed design of multiproduct batch plants considering production scheduling [texte imprimé] / Yanina Fumero, Auteur ; Gabriela Corsano, Auteur ; Jorge M. Montagna, Auteur . - 2011 . - pp. 6146-6160.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6146-6160
Mots-clés : Scheduling Production Batchwise Design Résumé : Most previous approaches for the design of multiproduct batch plants have assumed the simplest scheduling policy. In order to simplify the formulation and take into account that many times demands are uncertain, they have used single product campaigns to determine the plant configuration and select the unit sizes. From the commercial point of view, this production mode is not realistic: for example, huge inventories should be kept to support this approach. However, when a stable context can be assured, the simultaneous resolution of design and a more detailed scheduling allows assessing different trade-offs. This article presents a new mixed integer linear programming (MILP) formulation assuming mixed product campaigns. Now, the composition and the sequence of the batches in the campaign must be determined as well as the assignment of batches to units when parallel units are used. Taking into account that the plant configuration is simultaneously obtained, the scheduling problem must be solved without knowing the number of available units and their sizes. Several examples are presented in order to show the performance of the proposed approach. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158914 Exemplaires
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Titre : Novel method based on electric field simulation and optimization for designing an energy-saving magnesium electrolysis cell Type de document : texte imprimé Auteurs : Ze Sun, Auteur ; Yun Zhao, Auteur ; Guimin Lu, Auteur Année de publication : 2011 Article en page(s) : pp. 6161-6173 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Electrolysis cell Energy conservation Optimization Electric field Résumé : In this study, on the basis of simulation of the electric field, the design optimization methods for 120 and 250 kA magnesium electrolysis cells were developed. A 3D numerical model was built to simulate the electric field at the steady state to obtain the minimum resistance voltage which has a significant effect on the energy consumption in the magnesium electrolysis process. The major optimization was focused on adjustment of structural parameters, such as the relative positions of the anode and cathode, electrolyte height in the cell, and so on. An orthogonal design approach was used to optimize the structural parameters in a 120 kA cell, and the optimization criterion was applied to magnify the design of a 250 kA cell. The resistance voltage in the optimized 250 kAcell was computed, and the minimum resistance voltage was 1631.3 mV among the provided solutions. Hence, the developed model and simulation results would be useful for the design optimization of a magnesium electrolysis cell. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158915
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6161-6173[article] Novel method based on electric field simulation and optimization for designing an energy-saving magnesium electrolysis cell [texte imprimé] / Ze Sun, Auteur ; Yun Zhao, Auteur ; Guimin Lu, Auteur . - 2011 . - pp. 6161-6173.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6161-6173
Mots-clés : Electrolysis cell Energy conservation Optimization Electric field Résumé : In this study, on the basis of simulation of the electric field, the design optimization methods for 120 and 250 kA magnesium electrolysis cells were developed. A 3D numerical model was built to simulate the electric field at the steady state to obtain the minimum resistance voltage which has a significant effect on the energy consumption in the magnesium electrolysis process. The major optimization was focused on adjustment of structural parameters, such as the relative positions of the anode and cathode, electrolyte height in the cell, and so on. An orthogonal design approach was used to optimize the structural parameters in a 120 kA cell, and the optimization criterion was applied to magnify the design of a 250 kA cell. The resistance voltage in the optimized 250 kAcell was computed, and the minimum resistance voltage was 1631.3 mV among the provided solutions. Hence, the developed model and simulation results would be useful for the design optimization of a magnesium electrolysis cell. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158915 Exemplaires
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Titre : Dynamic modeling and optimal control of batch reactors, based on structure approaching hybrid neural networks Type de document : texte imprimé Auteurs : J. Wang, Auteur ; L. Lin Cao, Auteur ; H. Yan Wu, Auteur Année de publication : 2011 Article en page(s) : pp. 6174-6186 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Neural network Reactor Batchwise Optimal control Modeling Dynamic model Résumé : A novel Structure Approaching Hybrid Neural Network (SAHNN) approach to model batch reactors is presented. The Virtual Supervisor-Artificial Immune Algorithm method is utilized for the training of SAHNN, especially for the batch processes with partial unmeasurable state variables. SAHNN involves the use of approximate mechanistic equations to characterize unmeasured state variables. Since the main interest in batch process operation is on the end-of-batch product quality, an extended integral square error control index based on the SAHNN model is applied to track the desired temperature profile of a batch process. This approach introduces model mismatches and unmeasured disturbances into the optimal control strategy and provides a feedback channel for control. The performance of robustness and antidisturbances of the control system are then enhanced. The simulation result indicates that the SAHNN model and model-based optimal control strategy of the batch process are effective. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158916
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6174-6186[article] Dynamic modeling and optimal control of batch reactors, based on structure approaching hybrid neural networks [texte imprimé] / J. Wang, Auteur ; L. Lin Cao, Auteur ; H. Yan Wu, Auteur . - 2011 . - pp. 6174-6186.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6174-6186
Mots-clés : Neural network Reactor Batchwise Optimal control Modeling Dynamic model Résumé : A novel Structure Approaching Hybrid Neural Network (SAHNN) approach to model batch reactors is presented. The Virtual Supervisor-Artificial Immune Algorithm method is utilized for the training of SAHNN, especially for the batch processes with partial unmeasurable state variables. SAHNN involves the use of approximate mechanistic equations to characterize unmeasured state variables. Since the main interest in batch process operation is on the end-of-batch product quality, an extended integral square error control index based on the SAHNN model is applied to track the desired temperature profile of a batch process. This approach introduces model mismatches and unmeasured disturbances into the optimal control strategy and provides a feedback channel for control. The performance of robustness and antidisturbances of the control system are then enhanced. The simulation result indicates that the SAHNN model and model-based optimal control strategy of the batch process are effective. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158916 Exemplaires
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Titre : Binary distillation column startup using two temperature measurements Type de document : texte imprimé Auteurs : Eduardo Castellanos-Sahagun, Auteur ; Jesus Alvarez, Auteur Année de publication : 2011 Article en page(s) : pp. 6187-6204 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Temperature measurement Distillation column Résumé : The problem of designing the startup (SU) control scheme for a binary distillation column with two temperature and two level measurements is addressed. The objective is the quick attainment, with minimum off-spec production and heat consumption, of closed-loop stable operation in continuous regime. The combination of advanced constructive control and conventional distillation dynamics and control tools leads to a variable control structure scheme with: (i) an event controller which, on the basis of the two temperature measurements, decides the duration of an initial open-loop batch operation period at total reflux, and (ii) a set of four (two level and two temperature) linear-decentralized controllers activated in a sequential manner, which steers the column toward its nominal steady-state in a continuous regime, by manipulating the heat duty, reflux, distillate, and bottom flow rates. The proposed SU control scheme is tested through simulations with three high-purity column examples with ideal and nonideal thermodynamics, yielding a behavior that matches or improves the ones obtained in previous studies with detailed model-based schemes. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158917
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6187-6204[article] Binary distillation column startup using two temperature measurements [texte imprimé] / Eduardo Castellanos-Sahagun, Auteur ; Jesus Alvarez, Auteur . - 2011 . - pp. 6187-6204.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6187-6204
Mots-clés : Temperature measurement Distillation column Résumé : The problem of designing the startup (SU) control scheme for a binary distillation column with two temperature and two level measurements is addressed. The objective is the quick attainment, with minimum off-spec production and heat consumption, of closed-loop stable operation in continuous regime. The combination of advanced constructive control and conventional distillation dynamics and control tools leads to a variable control structure scheme with: (i) an event controller which, on the basis of the two temperature measurements, decides the duration of an initial open-loop batch operation period at total reflux, and (ii) a set of four (two level and two temperature) linear-decentralized controllers activated in a sequential manner, which steers the column toward its nominal steady-state in a continuous regime, by manipulating the heat duty, reflux, distillate, and bottom flow rates. The proposed SU control scheme is tested through simulations with three high-purity column examples with ideal and nonideal thermodynamics, yielding a behavior that matches or improves the ones obtained in previous studies with detailed model-based schemes. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158917 Exemplaires
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Titre : Process simulation of fuel ethanol production from lignocellulosics using aspen plus Type de document : texte imprimé Auteurs : Julian A. Quintero, Auteur ; Carlos A. Cardona, Auteur Année de publication : 2011 Article en page(s) : pp. 6205-6212 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Production Fuel Résumé : Fuel ethanol production has become one of the most studied processes in the last two decades because of the need to decrease its production cost and improve its energetic performance. The most promising raw material is lignocellulosic biomass because of its negligible cost and high availability. On the other hand, most research has focused on single steps and has not considered the whole process design. Aspen Plus allowed designing this kind of process while considering relevant aspects such as raw material composition and kinetic models of chemical and biological transformation. In this study fuel ethanol from rice hulls has been simulated considering the kinetic parameters for acid pretreatment, detoxification, and fermentation with the aim of assessing the energy performance of the process. In addition, the economic evaluation was accomplished using Aspen Process Economic Analyzer with the objective of calculating the production cost. It was found that the dilute acid pretreatment had a higher ethanol yield (347.25 L/t) and lower energy consumption (86.75 MJ/L) than liquid hot water pretreatment. However, the latter pretreatment had a lower production cost (US although when energy cogeneration and electricity sales were included in the analysis, dilute acid pretreatment became the most economic technology with a lower production cost (US$0.1918/L). DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158918
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6205-6212[article] Process simulation of fuel ethanol production from lignocellulosics using aspen plus [texte imprimé] / Julian A. Quintero, Auteur ; Carlos A. Cardona, Auteur . - 2011 . - pp. 6205-6212.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6205-6212
Mots-clés : Production Fuel Résumé : Fuel ethanol production has become one of the most studied processes in the last two decades because of the need to decrease its production cost and improve its energetic performance. The most promising raw material is lignocellulosic biomass because of its negligible cost and high availability. On the other hand, most research has focused on single steps and has not considered the whole process design. Aspen Plus allowed designing this kind of process while considering relevant aspects such as raw material composition and kinetic models of chemical and biological transformation. In this study fuel ethanol from rice hulls has been simulated considering the kinetic parameters for acid pretreatment, detoxification, and fermentation with the aim of assessing the energy performance of the process. In addition, the economic evaluation was accomplished using Aspen Process Economic Analyzer with the objective of calculating the production cost. It was found that the dilute acid pretreatment had a higher ethanol yield (347.25 L/t) and lower energy consumption (86.75 MJ/L) than liquid hot water pretreatment. However, the latter pretreatment had a lower production cost (US although when energy cogeneration and electricity sales were included in the analysis, dilute acid pretreatment became the most economic technology with a lower production cost (US$0.1918/L). DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158918 Exemplaires
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Titre : Disjunctive-genetic programming approach to synthesis of process networks Type de document : texte imprimé Auteurs : Andrew O. Odjo, Auteur ; Norman E. Sammons, Auteur ; Wei Yuan, Auteur Année de publication : 2011 Article en page(s) : pp. 6213-6228 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Disjunctive genetic programming Résumé : In this work, disjunctive-genetic programming (D-GP), based on the integration of genetic algorithm (GA) with the disjunctive formulations of generalized disjunctive programming (GDP) for the optimization of process networks, has been proposed. Discrete optimization problems, which give rise to the conditional modeling of equations through representations as logic based disjunctions, are very important and often appear in all scales of chemical engineering process network design and synthesis. The decomposition of the resulting mixed integer nonlinear programming (MINLP) problem obtained from the relaxation of the disjunctive formulation of the original problem results in alternating solutions of mixed integer linear programming (MILP) master problems and nonlinear programming (NLP) subproblems. With the increase in the problem scale, dealing with such alternating routes becomes difficult due to increased computational load and possible entanglement of the results in suboptimal solutions due to infeasibilities in the MILP space. In this work, the genetic algorithm (GA) has been used as a jumping operator to the different terms of the discrete search space and for the generation of different feasible fixed configurations. This proposed approach eliminates the need for the reformulation of the discrete/discontinuous optimization problems into direct MINLP problems, thus allowing for the solution of the original problem as a continuous optimization problem but only at each individual discrete and reduced search space. Segment-based mutation (SBM) and segment-based floating crossover (SBFC) strategies were proposed for the efficient handling of the population of chromosomes comprising the coded terms of the disjunctions. The effectiveness of D-GP as shown on various benchmark problems involving heat exchange equipment design and network problems as well as a classical process network problem shows this may be a promising approach in dealing with process network problems with large discontinuous objective and/or constraint functions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1017699
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6213-6228[article] Disjunctive-genetic programming approach to synthesis of process networks [texte imprimé] / Andrew O. Odjo, Auteur ; Norman E. Sammons, Auteur ; Wei Yuan, Auteur . - 2011 . - pp. 6213-6228.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6213-6228
Mots-clés : Disjunctive genetic programming Résumé : In this work, disjunctive-genetic programming (D-GP), based on the integration of genetic algorithm (GA) with the disjunctive formulations of generalized disjunctive programming (GDP) for the optimization of process networks, has been proposed. Discrete optimization problems, which give rise to the conditional modeling of equations through representations as logic based disjunctions, are very important and often appear in all scales of chemical engineering process network design and synthesis. The decomposition of the resulting mixed integer nonlinear programming (MINLP) problem obtained from the relaxation of the disjunctive formulation of the original problem results in alternating solutions of mixed integer linear programming (MILP) master problems and nonlinear programming (NLP) subproblems. With the increase in the problem scale, dealing with such alternating routes becomes difficult due to increased computational load and possible entanglement of the results in suboptimal solutions due to infeasibilities in the MILP space. In this work, the genetic algorithm (GA) has been used as a jumping operator to the different terms of the discrete search space and for the generation of different feasible fixed configurations. This proposed approach eliminates the need for the reformulation of the discrete/discontinuous optimization problems into direct MINLP problems, thus allowing for the solution of the original problem as a continuous optimization problem but only at each individual discrete and reduced search space. Segment-based mutation (SBM) and segment-based floating crossover (SBFC) strategies were proposed for the efficient handling of the population of chromosomes comprising the coded terms of the disjunctions. The effectiveness of D-GP as shown on various benchmark problems involving heat exchange equipment design and network problems as well as a classical process network problem shows this may be a promising approach in dealing with process network problems with large discontinuous objective and/or constraint functions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie1017699 Exemplaires
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Titre : Estimation of instrument variance and bias using bayesian methods Type de document : texte imprimé Auteurs : Ruben Gonzalez, Auteur ; Biao Huang, Auteur ; Fangwei Xu, Auteur Année de publication : 2011 Article en page(s) : pp. 6229-6239 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Bias Instruments Résumé : Imprecision of sensors is one of the main causes of poor control and process performance. Often, instrument measurement bias and variance change over the time and online calibration/re-estimation is necessary. Originated from a real industrial application problem, this paper proposed a Bayesian approach to determine the inconsistency of sensors, based on mass-balance principles. A mass-balance factor model is then introduced, where the factor analysis method is used to determine initial values for estimating instrument noise and process disturbance variance. Because of the structural constraint of mass-balance equations, a gray-box estimation procedure must be adopted for which Bayesian network estimation via the expectation-maximization (EM) algorithm is a very suitable method. Therefore, this paper uses factor analysis to determine the initial values, and, afterward, estimates process and sensor variance by means of Bayesian estimation. After estimating the process and instrument variance, the process steady state and instrument bias can be similarly estimated. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158920
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6229-6239[article] Estimation of instrument variance and bias using bayesian methods [texte imprimé] / Ruben Gonzalez, Auteur ; Biao Huang, Auteur ; Fangwei Xu, Auteur . - 2011 . - pp. 6229-6239.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6229-6239
Mots-clés : Bias Instruments Résumé : Imprecision of sensors is one of the main causes of poor control and process performance. Often, instrument measurement bias and variance change over the time and online calibration/re-estimation is necessary. Originated from a real industrial application problem, this paper proposed a Bayesian approach to determine the inconsistency of sensors, based on mass-balance principles. A mass-balance factor model is then introduced, where the factor analysis method is used to determine initial values for estimating instrument noise and process disturbance variance. Because of the structural constraint of mass-balance equations, a gray-box estimation procedure must be adopted for which Bayesian network estimation via the expectation-maximization (EM) algorithm is a very suitable method. Therefore, this paper uses factor analysis to determine the initial values, and, afterward, estimates process and sensor variance by means of Bayesian estimation. After estimating the process and instrument variance, the process steady state and instrument bias can be similarly estimated. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158920 Exemplaires
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Titre : Detailed scheduling of operations in single-source refined products pipelines Type de document : texte imprimé Auteurs : Vanina G. Cafaro, Auteur ; Diego C. Cafaro, Auteur ; Carlos A. Méndez, Auteur Année de publication : 2011 Article en page(s) : pp. 6240-6259 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Scheduling Résumé : The short-term scheduling of refined products pipelines is a very complex problem with many operational constraints to be considered Available nondiscrete planning approaches just provide the input schedule and the set of aggregate product deliveries to be performed from in-transit lots to depots at every batch injection. To determine the sequence of individual cuts on each batch to be accomplished by the pipeline operator, it is still necessary to refine such an aggregate plan. To do so, new computational tools for efficiently generating the detailed schedule of single-source pipelines with multiple distribution terminals are presented. Two types of methodologies are proposed. On one hand, it is developed a continuous-time mixed-integer linear programming (MILP) formulation that seeks to minimize both the total flow restart volume and the number of single-delivery pumping runs over the planning horizon. In this way, substantial savings in energy consumption and pump maintenance costs are achieved. Effective solution strategies for the MILP model are also designed to deal with large pipeline scheduling problems. On the other hand, three different heuristic rules for selecting the receiving terminal are introduced. By applying those rules in combination with a discrete-event simulation model, not only alternative detailed schedules can be generated in a very short CPU time but also some of them are near-optimal solutions. Three instances of a case study aimed at finding the detailed schedule of a real-world single-source pipeline system are solved through the proposed optimization and discrete-event simulation methods. Results are analyzed to assess the quality of the generated solutions and the required computational costs. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158921
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6240-6259[article] Detailed scheduling of operations in single-source refined products pipelines [texte imprimé] / Vanina G. Cafaro, Auteur ; Diego C. Cafaro, Auteur ; Carlos A. Méndez, Auteur . - 2011 . - pp. 6240-6259.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6240-6259
Mots-clés : Scheduling Résumé : The short-term scheduling of refined products pipelines is a very complex problem with many operational constraints to be considered Available nondiscrete planning approaches just provide the input schedule and the set of aggregate product deliveries to be performed from in-transit lots to depots at every batch injection. To determine the sequence of individual cuts on each batch to be accomplished by the pipeline operator, it is still necessary to refine such an aggregate plan. To do so, new computational tools for efficiently generating the detailed schedule of single-source pipelines with multiple distribution terminals are presented. Two types of methodologies are proposed. On one hand, it is developed a continuous-time mixed-integer linear programming (MILP) formulation that seeks to minimize both the total flow restart volume and the number of single-delivery pumping runs over the planning horizon. In this way, substantial savings in energy consumption and pump maintenance costs are achieved. Effective solution strategies for the MILP model are also designed to deal with large pipeline scheduling problems. On the other hand, three different heuristic rules for selecting the receiving terminal are introduced. By applying those rules in combination with a discrete-event simulation model, not only alternative detailed schedules can be generated in a very short CPU time but also some of them are near-optimal solutions. Three instances of a case study aimed at finding the detailed schedule of a real-world single-source pipeline system are solved through the proposed optimization and discrete-event simulation methods. Results are analyzed to assess the quality of the generated solutions and the required computational costs. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158921 Exemplaires
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Titre : Influence of tangent pinch points on the energy demand of batch distillations : development of a conceptual model for binary mixtures Type de document : texte imprimé Auteurs : Karina Andrea Torres, Auteur ; Jose Espinosa, Auteur Année de publication : 2011 Article en page(s) : pp. 6260-6275 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Binary mixture Modeling Distillation Batchwise Résumé : This contribution explores the influence of tangent pinch points on the performance of batch distillations of highly nonideal binary mixtures and its incorporation into a conceptual modeling framework under the assumption of a rectifier with an infinite number of stages. First of all, the y-x diagram is divided into three regions taking into account both the inflection point (IP) in the phase diagram and the slope of the equilibrium curve at xD = 1. After that, limiting values for the reflux ratio and distillate composition; namely, r* and x*D are calculated for the instantaneous still composition xB with the aid of region-dependent algorithms, which incorporate the tangency condition in different ways. Finally, the instantaneous column performance is estimated taking into account the selected operation mode; i.e., constant reflux ratio or constant distillate composition. Applied to the mixture acetone-water, results for complete simulations are presented in terms of both rectification advance and operation time. A brief comparative study on the minimum energy demand required for a given separation as estimated from models with and without tangent pinches is also carried out. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158922
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6260-6275[article] Influence of tangent pinch points on the energy demand of batch distillations : development of a conceptual model for binary mixtures [texte imprimé] / Karina Andrea Torres, Auteur ; Jose Espinosa, Auteur . - 2011 . - pp. 6260-6275.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6260-6275
Mots-clés : Binary mixture Modeling Distillation Batchwise Résumé : This contribution explores the influence of tangent pinch points on the performance of batch distillations of highly nonideal binary mixtures and its incorporation into a conceptual modeling framework under the assumption of a rectifier with an infinite number of stages. First of all, the y-x diagram is divided into three regions taking into account both the inflection point (IP) in the phase diagram and the slope of the equilibrium curve at xD = 1. After that, limiting values for the reflux ratio and distillate composition; namely, r* and x*D are calculated for the instantaneous still composition xB with the aid of region-dependent algorithms, which incorporate the tangency condition in different ways. Finally, the instantaneous column performance is estimated taking into account the selected operation mode; i.e., constant reflux ratio or constant distillate composition. Applied to the mixture acetone-water, results for complete simulations are presented in terms of both rectification advance and operation time. A brief comparative study on the minimum energy demand required for a given separation as estimated from models with and without tangent pinches is also carried out. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158922 Exemplaires
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Titre : Facility location and supply chain optimization for a biorefinery Type de document : texte imprimé Auteurs : Ian M. Bowling, Auteur ; José María Ponce-Ortega, Auteur ; Mahmoud M. El-Halwagi, Auteur Année de publication : 2011 Article en page(s) : pp. 6276-6286 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Optimization Résumé : This paper presents a systematic approach for the optimal production planning and facility placement of a biorefinery. A structural representation is first developed to include sources of biomass feedstock, distributed preprocessing hubs, and centralized processing facilities to produce desired products and byproducts. An optimization formulation is developed to determine the optimal supply chain, size, operational strategies, and location of the biorefinery and preprocessing hub facilities. The model considers simultaneously the optimal selection of different configurations considering the specific location configuration (centralized and/or distributed), selection of biomass, and processing facilities to determine the one with the maximum overall net profit. The objective function considers the overall sales and the costs for the feedstocks, transportation costs, capital costs for the facilities, and the operational costs for the facilities. The model also considers nonlinear economy-of-scale behavior of the capital-cost functions that are reformulated using disjunctive models to yield convex relationships to guarantee a global optimal solution. The proposed model was applied to two case studies. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158923
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6276-6286[article] Facility location and supply chain optimization for a biorefinery [texte imprimé] / Ian M. Bowling, Auteur ; José María Ponce-Ortega, Auteur ; Mahmoud M. El-Halwagi, Auteur . - 2011 . - pp. 6276-6286.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6276-6286
Mots-clés : Optimization Résumé : This paper presents a systematic approach for the optimal production planning and facility placement of a biorefinery. A structural representation is first developed to include sources of biomass feedstock, distributed preprocessing hubs, and centralized processing facilities to produce desired products and byproducts. An optimization formulation is developed to determine the optimal supply chain, size, operational strategies, and location of the biorefinery and preprocessing hub facilities. The model considers simultaneously the optimal selection of different configurations considering the specific location configuration (centralized and/or distributed), selection of biomass, and processing facilities to determine the one with the maximum overall net profit. The objective function considers the overall sales and the costs for the feedstocks, transportation costs, capital costs for the facilities, and the operational costs for the facilities. The model also considers nonlinear economy-of-scale behavior of the capital-cost functions that are reformulated using disjunctive models to yield convex relationships to guarantee a global optimal solution. The proposed model was applied to two case studies. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158923 Exemplaires
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Titre : Shortcut design of fully thermally coupled distillation systems with postfractionator Type de document : texte imprimé Auteurs : Lorena E. Ruiz-Marin, Auteur ; Nelly Ramirez-Corona, Auteur ; Angel Castro-Aguero, Auteur Année de publication : 2011 Article en page(s) : pp. 6287-6296 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Distillation Design Résumé : A modification to the fully thermally coupled distillation system, or Petlyuk column, in which a postfractionator is added has recently been considered. The modified structure incorporates the postfractionator aiming for a better match in the composition of the interlinking stages of the Petlyuk column. In this paper we present a design method for the modified thermally coupled system with postfractionator. A shortcut method is used to provide the minimum reflux conditions of the system, and the boundary value method is used to complete the design task. The effectiveness of the design method is shown through the application to several case studies. The effect of the postfractionator on the performance of the Petlyuk system is also analyzed. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158924
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6287-6296[article] Shortcut design of fully thermally coupled distillation systems with postfractionator [texte imprimé] / Lorena E. Ruiz-Marin, Auteur ; Nelly Ramirez-Corona, Auteur ; Angel Castro-Aguero, Auteur . - 2011 . - pp. 6287-6296.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6287-6296
Mots-clés : Distillation Design Résumé : A modification to the fully thermally coupled distillation system, or Petlyuk column, in which a postfractionator is added has recently been considered. The modified structure incorporates the postfractionator aiming for a better match in the composition of the interlinking stages of the Petlyuk column. In this paper we present a design method for the modified thermally coupled system with postfractionator. A shortcut method is used to provide the minimum reflux conditions of the system, and the boundary value method is used to complete the design task. The effectiveness of the design method is shown through the application to several case studies. The effect of the postfractionator on the performance of the Petlyuk system is also analyzed. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158924 Exemplaires
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Titre : Development of a scalable and comprehensive infrastructure model for carbon dioxide utilization and disposal Type de document : texte imprimé Auteurs : Jee-Hoon Han, Auteur ; In-Beum Lee, Auteur Année de publication : 2011 Article en page(s) : pp. 6297-6315 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Carbon dioxide Modeling Résumé : Much of the previous research on carbon capture and storage (CCS) has focused on individual technologies for disposing of CO2, such as capture, storage, sequestration, or transport. Moreover, recent research work considers utilization of CO2 as fuels, chemicals, or nutrients for bioreactors. To efficiently manage CO2 and the economic benefits achieved by this process, the CO2 transport and processing infrastructure supporting CCS will have to be constructed at a macro-scale. This paper introduces a scalable and comprehensive infrastructure model for CO2 utilization and disposal that generates an integrated, profit-maximizing CCS system. The proposed model determines where and how much CO2 to capture, store, transport, utilize or sequester to maximize total annual profit while meeting the CO2 mitigation target. The applicability of the proposed model is demonstrated using a case study for treating CO2 emitted by an industrial complex on the eastern coast of Korea in 2020. The results may be important in systematic planning of a CCS infrastructure and in assisting national and international policy makers to determine investment strategies for developing CCS infrastructures. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158925
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6297-6315[article] Development of a scalable and comprehensive infrastructure model for carbon dioxide utilization and disposal [texte imprimé] / Jee-Hoon Han, Auteur ; In-Beum Lee, Auteur . - 2011 . - pp. 6297-6315.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6297-6315
Mots-clés : Carbon dioxide Modeling Résumé : Much of the previous research on carbon capture and storage (CCS) has focused on individual technologies for disposing of CO2, such as capture, storage, sequestration, or transport. Moreover, recent research work considers utilization of CO2 as fuels, chemicals, or nutrients for bioreactors. To efficiently manage CO2 and the economic benefits achieved by this process, the CO2 transport and processing infrastructure supporting CCS will have to be constructed at a macro-scale. This paper introduces a scalable and comprehensive infrastructure model for CO2 utilization and disposal that generates an integrated, profit-maximizing CCS system. The proposed model determines where and how much CO2 to capture, store, transport, utilize or sequester to maximize total annual profit while meeting the CO2 mitigation target. The applicability of the proposed model is demonstrated using a case study for treating CO2 emitted by an industrial complex on the eastern coast of Korea in 2020. The results may be important in systematic planning of a CCS infrastructure and in assisting national and international policy makers to determine investment strategies for developing CCS infrastructures. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158925 Exemplaires
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Titre : Production scheduling in multiproduct multistage semicontinuous food processes Type de document : texte imprimé Auteurs : Kopanos, Georgios M., Auteur ; Puigjaner, Luis, Auteur ; Michael C. Georgiadis, Auteur Année de publication : 2011 Article en page(s) : pp. 6316-6324 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Food engineering Semicontinuous Scheduling Production Résumé : This works presents a novel mixed-integer programming framework and a solution strategy for the optimal production scheduling of multiproduct and multistage food process industries, such as ice-cream production facilities, studied in detail. The overall mathematical framework relies on an efficient modeling approach of the sequencing decisions, the integrated modeling of all production stages, and the inclusion of strong valid integer cuts in the formulation. The simultaneous optimization of all processing stages increases the plant production capacity, reduces the production cost for final products, and facilitates interaction among the different departments of the production facility. Several instances of a real-life industrial case study concerning ice-cream production have been solved to optimality to illustrate the applicability and efficiency of the overall modeling and solution approach. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158926
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6316-6324[article] Production scheduling in multiproduct multistage semicontinuous food processes [texte imprimé] / Kopanos, Georgios M., Auteur ; Puigjaner, Luis, Auteur ; Michael C. Georgiadis, Auteur . - 2011 . - pp. 6316-6324.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6316-6324
Mots-clés : Food engineering Semicontinuous Scheduling Production Résumé : This works presents a novel mixed-integer programming framework and a solution strategy for the optimal production scheduling of multiproduct and multistage food process industries, such as ice-cream production facilities, studied in detail. The overall mathematical framework relies on an efficient modeling approach of the sequencing decisions, the integrated modeling of all production stages, and the inclusion of strong valid integer cuts in the formulation. The simultaneous optimization of all processing stages increases the plant production capacity, reduces the production cost for final products, and facilitates interaction among the different departments of the production facility. Several instances of a real-life industrial case study concerning ice-cream production have been solved to optimality to illustrate the applicability and efficiency of the overall modeling and solution approach. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158926 Exemplaires
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Titre : Utilization of bipolar membrane electrodialysis for the removal of boron from aqueous solution Type de document : texte imprimé Auteurs : Hiroki Nagasawa, Auteur ; Atsushi Iizuka, Auteur ; Akihiro Yamasaki, Auteur Année de publication : 2011 Article en page(s) : pp. 6325-6330 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Membrane separation Aqueous solution Electrodialysis Bipolar membrane Résumé : Bipolar membrane electrodialysis (BMED) was used to remove boron from aqueous solution. BMED was compared with conventional electrodialysis (ED) using aqueous solutions of sodium tetraborate containing 100 mg/L of boron. With use of BMED, more than 90% of the boron was removed under both acidic (pH 2.3) and basic (pH 9.1) conditions, whereas only 35-45% of the boron was removed using conventional ED. Over 90% of the boron was removed from the diluate solution over a wide range of initial pH from 2.3 to 12.0. A high initial pH reduces the current efficiency of boron removal because of the high mobility and high concentration of hydroxide ions compared with those of borate ions. The power requirement for boron removal increased as the initial pH and concentration of sodium chloride increased, but decreased as the applied voltage was increased. BMED is a promising option for removal of boron from aqueous solution. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158927
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6325-6330[article] Utilization of bipolar membrane electrodialysis for the removal of boron from aqueous solution [texte imprimé] / Hiroki Nagasawa, Auteur ; Atsushi Iizuka, Auteur ; Akihiro Yamasaki, Auteur . - 2011 . - pp. 6325-6330.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6325-6330
Mots-clés : Membrane separation Aqueous solution Electrodialysis Bipolar membrane Résumé : Bipolar membrane electrodialysis (BMED) was used to remove boron from aqueous solution. BMED was compared with conventional electrodialysis (ED) using aqueous solutions of sodium tetraborate containing 100 mg/L of boron. With use of BMED, more than 90% of the boron was removed under both acidic (pH 2.3) and basic (pH 9.1) conditions, whereas only 35-45% of the boron was removed using conventional ED. Over 90% of the boron was removed from the diluate solution over a wide range of initial pH from 2.3 to 12.0. A high initial pH reduces the current efficiency of boron removal because of the high mobility and high concentration of hydroxide ions compared with those of borate ions. The power requirement for boron removal increased as the initial pH and concentration of sodium chloride increased, but decreased as the applied voltage was increased. BMED is a promising option for removal of boron from aqueous solution. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158927 Exemplaires
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Titre : On column profile maps : an analysis of sharp splits Type de document : texte imprimé Auteurs : Daniel A. Beneke, Auteur ; Diane Hildebrandt, Auteur ; David Glasser, Auteur Année de publication : 2011 Article en page(s) : pp. 6331-6342 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Cartography Résumé : Column profile maps (CPMs) have recently been shown to be a useful tool in the design of distillation operations, especially complex configurations. CPMs are essentially a family of composition trajectories for a column section in a distillation column. They have been shown to be topological transforms of residue curve maps, and are dependent on two main parameters: RΔ (generalized reflux) and XΔ (a pseudocomposition vector), which effectively fixes the net flow in a column section. This paper focuses on the interaction between these parameters for the special case of sharp splits. With the CPM technique it has been shown that sharp splits behave in a unique manner, due to a phenomenon termed as "node bumping". In particular, it has been shown that it is possible to locate specific ranges of RΔ where one may drastically influence the movement of profiles in somewhat counterintuitive directions. Although this effect may not be useful in product producing column sections, it is shown how these unique phenomena can affect a separation in a desirable manner, especially when designing unconventional column configurations. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158928
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6331-6342[article] On column profile maps : an analysis of sharp splits [texte imprimé] / Daniel A. Beneke, Auteur ; Diane Hildebrandt, Auteur ; David Glasser, Auteur . - 2011 . - pp. 6331-6342.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6331-6342
Mots-clés : Cartography Résumé : Column profile maps (CPMs) have recently been shown to be a useful tool in the design of distillation operations, especially complex configurations. CPMs are essentially a family of composition trajectories for a column section in a distillation column. They have been shown to be topological transforms of residue curve maps, and are dependent on two main parameters: RΔ (generalized reflux) and XΔ (a pseudocomposition vector), which effectively fixes the net flow in a column section. This paper focuses on the interaction between these parameters for the special case of sharp splits. With the CPM technique it has been shown that sharp splits behave in a unique manner, due to a phenomenon termed as "node bumping". In particular, it has been shown that it is possible to locate specific ranges of RΔ where one may drastically influence the movement of profiles in somewhat counterintuitive directions. Although this effect may not be useful in product producing column sections, it is shown how these unique phenomena can affect a separation in a desirable manner, especially when designing unconventional column configurations. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158928 Exemplaires
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Titre : Modified chitosan hydrogels for the removal of acid dyes at high pH : modification and regeneration Type de document : texte imprimé Auteurs : Dan Xu, Auteur ; San Hein, Auteur ; Sunsun Leslie Loo, Auteur Année de publication : 2011 Article en page(s) : pp. 6343-6346 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : pH Acid dye Résumé : Chitosan hydrogels were modified with (NH4)2SO4 solution using two methods and were tested in adsorbing acid dyes at a high pH of 8.2. The modified chitosan presented significantly improved adsorption capacities toward two dye samples: acid orange 7 and acid red 18. Specifically, these capacities were about 7.4 and 14.4 times higher than those of native chitosan, respectively, at the same conditions. The ion-exchange mechanism of the dye adsorption on the modified sample was proposed and verified by FTIR spectra. Regeneration experiments showed that the dye exhausted sample can be almost completely regenerated with NaOH solution while the capacity was largely retained even after 20 cycles of adsorption-regeneration-modification processes. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158929
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6343-6346[article] Modified chitosan hydrogels for the removal of acid dyes at high pH : modification and regeneration [texte imprimé] / Dan Xu, Auteur ; San Hein, Auteur ; Sunsun Leslie Loo, Auteur . - 2011 . - pp. 6343-6346.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6343-6346
Mots-clés : pH Acid dye Résumé : Chitosan hydrogels were modified with (NH4)2SO4 solution using two methods and were tested in adsorbing acid dyes at a high pH of 8.2. The modified chitosan presented significantly improved adsorption capacities toward two dye samples: acid orange 7 and acid red 18. Specifically, these capacities were about 7.4 and 14.4 times higher than those of native chitosan, respectively, at the same conditions. The ion-exchange mechanism of the dye adsorption on the modified sample was proposed and verified by FTIR spectra. Regeneration experiments showed that the dye exhausted sample can be almost completely regenerated with NaOH solution while the capacity was largely retained even after 20 cycles of adsorption-regeneration-modification processes. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158929 Exemplaires
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Titre : Effect of hydroxyl content and molecular weight of biodegradable ethylcellulose on demulsification of water-in-diluted bitumen emulsions Type de document : texte imprimé Auteurs : Xianhua Feng, Auteur ; Shengqun Wang, Auteur ; Jun Hou, Auteur Année de publication : 2011 Article en page(s) : pp. 6347-6354 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Emulsion Bitumen Demulsification Résumé : Ethylcellulose (EC) polymers with different hydroxyl content and molecular weight were synthesized in tetrabutyl ammonium fluoride/dimethyl sulfoxide medium. Their performance for demulsification of water-in-naphtha diluted bitumen emulsions was evaluated. It was found that EC with 4.5 wt % hydroxyl (degree of hydroxyl substitution, 2.4) is the most effective in demulsification. The demulsification efficiency of EC could be linked to its interfacial activity and potency of flocculation. The potency of flocculation by EC depends on its molecular weight and hydroxyl content, which affect molecular interactions. EC with higher molecular weight was found to be more effective in the demulsification of water-in-naphtha diluted bitumen emulsions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158930
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6347-6354[article] Effect of hydroxyl content and molecular weight of biodegradable ethylcellulose on demulsification of water-in-diluted bitumen emulsions [texte imprimé] / Xianhua Feng, Auteur ; Shengqun Wang, Auteur ; Jun Hou, Auteur . - 2011 . - pp. 6347-6354.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6347-6354
Mots-clés : Emulsion Bitumen Demulsification Résumé : Ethylcellulose (EC) polymers with different hydroxyl content and molecular weight were synthesized in tetrabutyl ammonium fluoride/dimethyl sulfoxide medium. Their performance for demulsification of water-in-naphtha diluted bitumen emulsions was evaluated. It was found that EC with 4.5 wt % hydroxyl (degree of hydroxyl substitution, 2.4) is the most effective in demulsification. The demulsification efficiency of EC could be linked to its interfacial activity and potency of flocculation. The potency of flocculation by EC depends on its molecular weight and hydroxyl content, which affect molecular interactions. EC with higher molecular weight was found to be more effective in the demulsification of water-in-naphtha diluted bitumen emulsions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158930 Exemplaires
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Titre : Selective separation of Cu(II) from aqueous solution with a novel Cu(II) surface magnetic ion-imprinted polymer Type de document : texte imprimé Auteurs : Youcai Zhan, Auteur ; Xubiao Luo, Auteur ; Shanshan Nie, Auteur Année de publication : 2011 Article en page(s) : pp. 6355-6361 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Aqueous solution Résumé : A novel Cu(II) magnetic ion-imprinted polymer (MIIP) was prepared via the sol-gel method. The Cu(II)-MIIP exhibited good magnetic property and thermal stability. The binding characteristics of Cu(II)-MIIP were studied by adopting both static and dynamic adsorption experiments. The maximum adsorptions calculated from the Langmuir isotherm are 58.20 and 23.10 mg/g for Cu(II)-MIIP and magnetic nonimprinted polymer (MNIP), respectively. The kinetics studies showed that the adsorption process obeyed a pseudo-second-order kinetic model. The selectivity coefficients of the Cu(II)-MIIP for Cu(II) in the presence of Zn(II) and Ni(II) are 49.44 and 50.38, respectively. The relative selectivity coefficients of cu(II)-MIIP for Cu(II)/Zn(II) and Cu(II)/Ni(II) are 12.36 and 8.73, respectively. Moreover, Cu(II)-MIIP could be used five times without obvious deterioration in their adsorption capacities. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158931
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6355-6361[article] Selective separation of Cu(II) from aqueous solution with a novel Cu(II) surface magnetic ion-imprinted polymer [texte imprimé] / Youcai Zhan, Auteur ; Xubiao Luo, Auteur ; Shanshan Nie, Auteur . - 2011 . - pp. 6355-6361.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6355-6361
Mots-clés : Aqueous solution Résumé : A novel Cu(II) magnetic ion-imprinted polymer (MIIP) was prepared via the sol-gel method. The Cu(II)-MIIP exhibited good magnetic property and thermal stability. The binding characteristics of Cu(II)-MIIP were studied by adopting both static and dynamic adsorption experiments. The maximum adsorptions calculated from the Langmuir isotherm are 58.20 and 23.10 mg/g for Cu(II)-MIIP and magnetic nonimprinted polymer (MNIP), respectively. The kinetics studies showed that the adsorption process obeyed a pseudo-second-order kinetic model. The selectivity coefficients of the Cu(II)-MIIP for Cu(II) in the presence of Zn(II) and Ni(II) are 49.44 and 50.38, respectively. The relative selectivity coefficients of cu(II)-MIIP for Cu(II)/Zn(II) and Cu(II)/Ni(II) are 12.36 and 8.73, respectively. Moreover, Cu(II)-MIIP could be used five times without obvious deterioration in their adsorption capacities. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158931 Exemplaires
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Titre : Three-liquid-phase extraction and separation of Ti(IV), Fe(III), and Mg(II) Type de document : texte imprimé Auteurs : Keng Xie, Auteur ; Kun Huang, Auteur ; Lin Xu, Auteur Année de publication : 2011 Article en page(s) : pp. 6362-6368 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Liquid phase Résumé : Three-liquid-phase extraction has been considered to be a promising method for isolation and separation of multicomponents. Selective extraction-separation of Ti(IV), Fe(III), and Mg(II) in the three-liquid-phase system containing trialkylphosphine oxide (TRPO), poly(ethylene glycol) with an average molecular mass of 2000 (PEG 2000), and (NH4)2SO4 was achieved by adding a water-soluble complexing agent, ethylenediaminetetraacetic acid (EDTA). The simple and environmentally benign complexing method was proved to be an effective strategy for enhancing the selectivity of the PEG-2000-rich middle phase for Fe(III) without reducing the affinity of the TRPO-rich top phase to Ti(IV). The related chemistry was detailed, and effects of some important parameters such as the aqueous phase pH, EDTA amount, mixing time, and temperature were examined. It revealed that Ti(IV) and Fe(III) could be enriched respectively into the TRPO-rich top phase and the PEG-2000-rich middle phase through optimization of the aqueous pH and the EDTA amount. Ti(IV) was extracted into the top phase with a slow kinetics and a positive enthalpy change (ΔH), whereas Fe(III) was rapidly transferred to the middle phase as Fe(III)-EDTA complexes formed by an exothermic reaction. Mg(II) tended to remain in the bottom phase. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158932
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6362-6368[article] Three-liquid-phase extraction and separation of Ti(IV), Fe(III), and Mg(II) [texte imprimé] / Keng Xie, Auteur ; Kun Huang, Auteur ; Lin Xu, Auteur . - 2011 . - pp. 6362-6368.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6362-6368
Mots-clés : Liquid phase Résumé : Three-liquid-phase extraction has been considered to be a promising method for isolation and separation of multicomponents. Selective extraction-separation of Ti(IV), Fe(III), and Mg(II) in the three-liquid-phase system containing trialkylphosphine oxide (TRPO), poly(ethylene glycol) with an average molecular mass of 2000 (PEG 2000), and (NH4)2SO4 was achieved by adding a water-soluble complexing agent, ethylenediaminetetraacetic acid (EDTA). The simple and environmentally benign complexing method was proved to be an effective strategy for enhancing the selectivity of the PEG-2000-rich middle phase for Fe(III) without reducing the affinity of the TRPO-rich top phase to Ti(IV). The related chemistry was detailed, and effects of some important parameters such as the aqueous phase pH, EDTA amount, mixing time, and temperature were examined. It revealed that Ti(IV) and Fe(III) could be enriched respectively into the TRPO-rich top phase and the PEG-2000-rich middle phase through optimization of the aqueous pH and the EDTA amount. Ti(IV) was extracted into the top phase with a slow kinetics and a positive enthalpy change (ΔH), whereas Fe(III) was rapidly transferred to the middle phase as Fe(III)-EDTA complexes formed by an exothermic reaction. Mg(II) tended to remain in the bottom phase. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158932 Exemplaires
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Titre : Removal of carbon dioxide by absorption in microporous tube-in-tube microchannel reactor Type de document : texte imprimé Auteurs : Na-Na Gao, Auteur ; Jie-Xin Wang, Auteur ; Lei Shao, Auteur Année de publication : 2011 Article en page(s) : pp. 6369-6374 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Microreactor Microporosity Carbon dioxide Résumé : In this article, preliminary experimental results are presented on the absorption of carbon dioxide (CO2) in a novel high-throughput microporous tube-in-tube microchannel reactor (MTMCR), with an aqueous solution of monoethanolamine (MEA) and a mixture of CO2/N2 as the working fluids. The effects of design and operating parameters on the CO2 removal efficiency were investigated. The absorbent concentration was given the priority as a key factor for consideration, with the result that the CO2 removal efficiency increased with increasing concentrationan and could reach 90% or even higher at a high throughput of 440 L/h for gas with an MEA concentration of 30 wt %. With a decrease of the superficial gas velocity or an increase of the superficial liquid velocity, the CO2 removal efficiency increased. Increasing the absorbent temperature yielded better absorption performance. Reducing the most important structural parameters of the MTMCR, such as the micropore size and the annular channel width, led to ahigher mass-transfer rate and was beneficial for CO2 removal. This work also investigated the characteristics of the pressure drop of two-phase flows through the MTMCR. The results obtained imply a great potential for MTMCRs applied to the separation of the greenhouse gas CO2 from the exhausted gases. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158933
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6369-6374[article] Removal of carbon dioxide by absorption in microporous tube-in-tube microchannel reactor [texte imprimé] / Na-Na Gao, Auteur ; Jie-Xin Wang, Auteur ; Lei Shao, Auteur . - 2011 . - pp. 6369-6374.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6369-6374
Mots-clés : Microreactor Microporosity Carbon dioxide Résumé : In this article, preliminary experimental results are presented on the absorption of carbon dioxide (CO2) in a novel high-throughput microporous tube-in-tube microchannel reactor (MTMCR), with an aqueous solution of monoethanolamine (MEA) and a mixture of CO2/N2 as the working fluids. The effects of design and operating parameters on the CO2 removal efficiency were investigated. The absorbent concentration was given the priority as a key factor for consideration, with the result that the CO2 removal efficiency increased with increasing concentrationan and could reach 90% or even higher at a high throughput of 440 L/h for gas with an MEA concentration of 30 wt %. With a decrease of the superficial gas velocity or an increase of the superficial liquid velocity, the CO2 removal efficiency increased. Increasing the absorbent temperature yielded better absorption performance. Reducing the most important structural parameters of the MTMCR, such as the micropore size and the annular channel width, led to ahigher mass-transfer rate and was beneficial for CO2 removal. This work also investigated the characteristics of the pressure drop of two-phase flows through the MTMCR. The results obtained imply a great potential for MTMCRs applied to the separation of the greenhouse gas CO2 from the exhausted gases. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158933 Exemplaires
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Titre : Effects of cooling rate, saturation temperature, and solvent on the metastable zone width of triethanolamine hydrochloride Type de document : texte imprimé Auteurs : Yan Zhang, Auteur ; Zhibao Li, Auteur Année de publication : 2011 Article en page(s) : pp. 6375-6381 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Saturation Cooling Résumé : The metastable zone widths (MZWs) of triethanolamine hydrochloride ([HTEA]Cl), defined as the maximum temperature difference ΔTmax a solution can withstand before crystallization of a solid phase, in water, ethanol-water, and HCl-water mixed solvents have been determined at a saturation temperature To range from 293.15 to 303.15 K with cooling rate R from 3 to 8 K·h-1. Solubilities of [HTEA]Cl in ethanol-water mixtures have also been obtained using a dynamic method. An equation of MZW with similar form to Sangwal's equation was derived from the fundamental driving force of crystallization based on chemical potential. With the newly obtained equation, the experimental values of MZW ΔTmax for [HTEA]Cl-water system at 298.15 K was correlated with the cooling rate R by ln(ΔTmax/T0) = -6.140 + 1.222 In R. The enthalpy of mixing ΔHmix was calculated with the solubility data, and the result of differential scanning calorimetry (DSC). For [HTEA]Cl-water system, the value of ΔHmix was determined to be 30.88 kJ·mol-1, and the addition of both HCl and ethanol led to a decrease of -ΔHmix. The experimental results also showed that MZW could be greatly enhanced when ethanol and HCl were added. It was found that the values ofMZW decrease with -ΔHmix for both [HTEA]Cl-ethanol-water and [HTEA]Cl-HCl-water systems at the same saturation temperature and cooling rate. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158934
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6375-6381[article] Effects of cooling rate, saturation temperature, and solvent on the metastable zone width of triethanolamine hydrochloride [texte imprimé] / Yan Zhang, Auteur ; Zhibao Li, Auteur . - 2011 . - pp. 6375-6381.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6375-6381
Mots-clés : Saturation Cooling Résumé : The metastable zone widths (MZWs) of triethanolamine hydrochloride ([HTEA]Cl), defined as the maximum temperature difference ΔTmax a solution can withstand before crystallization of a solid phase, in water, ethanol-water, and HCl-water mixed solvents have been determined at a saturation temperature To range from 293.15 to 303.15 K with cooling rate R from 3 to 8 K·h-1. Solubilities of [HTEA]Cl in ethanol-water mixtures have also been obtained using a dynamic method. An equation of MZW with similar form to Sangwal's equation was derived from the fundamental driving force of crystallization based on chemical potential. With the newly obtained equation, the experimental values of MZW ΔTmax for [HTEA]Cl-water system at 298.15 K was correlated with the cooling rate R by ln(ΔTmax/T0) = -6.140 + 1.222 In R. The enthalpy of mixing ΔHmix was calculated with the solubility data, and the result of differential scanning calorimetry (DSC). For [HTEA]Cl-water system, the value of ΔHmix was determined to be 30.88 kJ·mol-1, and the addition of both HCl and ethanol led to a decrease of -ΔHmix. The experimental results also showed that MZW could be greatly enhanced when ethanol and HCl were added. It was found that the values ofMZW decrease with -ΔHmix for both [HTEA]Cl-ethanol-water and [HTEA]Cl-HCl-water systems at the same saturation temperature and cooling rate. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158934 Exemplaires
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Titre : Adsorptive removal of dimethyl disulfide in olefin rich C4 with ion-exchanged zeolites Type de document : texte imprimé Auteurs : Jieun Lee, Auteur ; Hee Tae Beum, Auteur ; Chang Hyun Ko, Auteur Année de publication : 2011 Article en page(s) : pp. 6382-6390 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Zeolite Résumé : The purpose of this study is to investigate the removal of dimethyl disulfide (DMDS) in the olefin rich Fluid Catalytic Cracking (FCC) C4 hydrocarbon mixture with the ion-exchanged β-zeolite. Effects of Si/Al ratio, metal cations, and the ion exchange level on the removal efficiency have been accessed by performing the breakthrough experiment with a model C4 mixture of 20 ppm DMDS in 40% n-Butane/60% 1-Butene. The metal ions used for the preparation of ion exchanged zeolite are Ag(I), Cu(II), Ni(II), Fe(III), and Cu(I). The adsorption characteristics of 1-Butene and DMDS on the adsorbent have been studied through the temperature programmed desorption (TPD). DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158935
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6382-6390[article] Adsorptive removal of dimethyl disulfide in olefin rich C4 with ion-exchanged zeolites [texte imprimé] / Jieun Lee, Auteur ; Hee Tae Beum, Auteur ; Chang Hyun Ko, Auteur . - 2011 . - pp. 6382-6390.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6382-6390
Mots-clés : Zeolite Résumé : The purpose of this study is to investigate the removal of dimethyl disulfide (DMDS) in the olefin rich Fluid Catalytic Cracking (FCC) C4 hydrocarbon mixture with the ion-exchanged β-zeolite. Effects of Si/Al ratio, metal cations, and the ion exchange level on the removal efficiency have been accessed by performing the breakthrough experiment with a model C4 mixture of 20 ppm DMDS in 40% n-Butane/60% 1-Butene. The metal ions used for the preparation of ion exchanged zeolite are Ag(I), Cu(II), Ni(II), Fe(III), and Cu(I). The adsorption characteristics of 1-Butene and DMDS on the adsorbent have been studied through the temperature programmed desorption (TPD). DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158935 Exemplaires
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Titre : Ammonium ion removal with a natural zeolite in monodispersed and segregated fluidized beds Type de document : texte imprimé Auteurs : Ayse Cecen Erbil, Auteur ; Elif Soyer, Auteur ; Bilsen Beler Baykal, Auteur Année de publication : 2011 Article en page(s) : pp. 6391-6403 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Fluidized bed Fluidization Zeolite Résumé : This study focuses on the dynamic behavior of ammonium ion uptake during continuous operation with respect to liquid by means of ion exchange with a natural zeolite in fluidized and segregated fluidized beds. The major operating variables affecting the performance in both types of fluidized beds are particle size, bed expansion, and flow rate. Use of particles of about 300 μm size in monodispersed fluidized beds resulted in breakthrough capacities of about 0.5 meq/g or higher, with contact times in the order of 0.7-5.5 min. The column efficiencies in terms of breakthrough capacity/total capacity were in the order of 0.42-0.61. The segregated fluidized bed, as achieved by using two nonmixing particle size fractions, is a hybrid fluidized bed consisting of an expanded bed with reduced mixing which is topped by a regular fluidized bed. Segregation increased the column efficiency to 0.69 when a combination of 250-300 and 500-600 μm sized particles were fluidized with a contact time of 1 min. The breakthrough capadties for the segregated fluidized beds with the finer particle size combination were 0.60-0.89 meq/g. A new representation of the breakthrough curves in terms of C/C0 versus a dimensionless time t/tf suggests that these plots are a valuable tool for comparing performances for a wide variety of experimental conditions. The results of this study indicate that fluidization can well be applied to ion exchange operations to accommodate high influent flow rates. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158936
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6391-6403[article] Ammonium ion removal with a natural zeolite in monodispersed and segregated fluidized beds [texte imprimé] / Ayse Cecen Erbil, Auteur ; Elif Soyer, Auteur ; Bilsen Beler Baykal, Auteur . - 2011 . - pp. 6391-6403.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6391-6403
Mots-clés : Fluidized bed Fluidization Zeolite Résumé : This study focuses on the dynamic behavior of ammonium ion uptake during continuous operation with respect to liquid by means of ion exchange with a natural zeolite in fluidized and segregated fluidized beds. The major operating variables affecting the performance in both types of fluidized beds are particle size, bed expansion, and flow rate. Use of particles of about 300 μm size in monodispersed fluidized beds resulted in breakthrough capacities of about 0.5 meq/g or higher, with contact times in the order of 0.7-5.5 min. The column efficiencies in terms of breakthrough capacity/total capacity were in the order of 0.42-0.61. The segregated fluidized bed, as achieved by using two nonmixing particle size fractions, is a hybrid fluidized bed consisting of an expanded bed with reduced mixing which is topped by a regular fluidized bed. Segregation increased the column efficiency to 0.69 when a combination of 250-300 and 500-600 μm sized particles were fluidized with a contact time of 1 min. The breakthrough capadties for the segregated fluidized beds with the finer particle size combination were 0.60-0.89 meq/g. A new representation of the breakthrough curves in terms of C/C0 versus a dimensionless time t/tf suggests that these plots are a valuable tool for comparing performances for a wide variety of experimental conditions. The results of this study indicate that fluidization can well be applied to ion exchange operations to accommodate high influent flow rates. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158936 Exemplaires
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Titre : An object-oriented approach for structure design of property calculation programs using equations of state Type de document : texte imprimé Auteurs : Lijuan Shi, Auteur ; Xiaodong Liang, Auteur Année de publication : 2011 Article en page(s) : pp. 6404–6412 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Equations of state calculation programs Résumé : A new object-oriented approach for designing general property calculation programs using different types of equations of state (EoS) is presented in this work. It helps to ease the programs’ extensibility, reusability, and maintainability and, at the same time, minimize the code redundancy. The approach consists of two parts: (a) the total Helmholtz free energy function is separated into specific terms, based on physical meanings or mathematical expressions, independent of the properties of interest, and the same or similar specific terms used in different equations of state are abstracted to general algorithms; (b) the general relationships between these algorithms and the properties of interest are implemented at the highest level of the program. According to this strategy, a general cubic algorithm can be abstracted for all of the cubic EoS. The general hard-sphere, hard-chain, and association algorithms can be aggregated into different Statistical Associating Fluid Theory (SAFT) family EoS with different dispersion algorithms. Similarly, the general cubic and association algorithms can be aggregated into Cubic Plus Association (CPA) EoS. Taking Perturbed-Chain SAFT (PC-SAFT) EoS as an example, this manuscript demonstrates a clear object-oriented structure for developers, with regard to how to design a complete thermodynamic model package using this approach. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101547t
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6404–6412[article] An object-oriented approach for structure design of property calculation programs using equations of state [texte imprimé] / Lijuan Shi, Auteur ; Xiaodong Liang, Auteur . - 2011 . - pp. 6404–6412.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6404–6412
Mots-clés : Equations of state calculation programs Résumé : A new object-oriented approach for designing general property calculation programs using different types of equations of state (EoS) is presented in this work. It helps to ease the programs’ extensibility, reusability, and maintainability and, at the same time, minimize the code redundancy. The approach consists of two parts: (a) the total Helmholtz free energy function is separated into specific terms, based on physical meanings or mathematical expressions, independent of the properties of interest, and the same or similar specific terms used in different equations of state are abstracted to general algorithms; (b) the general relationships between these algorithms and the properties of interest are implemented at the highest level of the program. According to this strategy, a general cubic algorithm can be abstracted for all of the cubic EoS. The general hard-sphere, hard-chain, and association algorithms can be aggregated into different Statistical Associating Fluid Theory (SAFT) family EoS with different dispersion algorithms. Similarly, the general cubic and association algorithms can be aggregated into Cubic Plus Association (CPA) EoS. Taking Perturbed-Chain SAFT (PC-SAFT) EoS as an example, this manuscript demonstrates a clear object-oriented structure for developers, with regard to how to design a complete thermodynamic model package using this approach. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie101547t Exemplaires
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Titre : Determination of inorganic salt solubility at a temperature above the boiling point of water by multiple headspace extraction gas chromatography Type de document : texte imprimé Auteurs : Xin-Sheng Chai, Auteur ; Christopher L. Verrill, Auteur Année de publication : 2011 Article en page(s) : pp. 6413-6417 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Gas chromatography Boiling point Solubility Résumé : This paper describes a novel method for the determination of the solubility of sodium carbonate and sodium sulfate in single- and bisalt aqueous solutions at 110 °C, using multiple headspace extraction gas chromatography (MHE-GC). Both benzene alcohol and methanol were used as the tracer compounds whose vapor-liquid equilibrium (VLE) partition coefficients (CV/CL) are related to the concentration of salt in the studied solution, thereby indirectly providing solubility data. During the MHE process, small amounts of water are removed stepwise by a series of headspace vapor extractions, which simulates the evaporation process, resulting in an increase in the salt concentration in the solution and a decrease in the amount of tracer in the headspace vapor. Eventually, the salt concentration reaches saturation (the limit of solubility), a transition point that can be identified experimentally via GC, because of the different behaviors of the tracer loss before and after the salt saturation point. Knowing the salt concentration in the initial solution and gathering data on the amount of water lost in reaching the transition point, we calculated the solubilities of sodium sulfate and sodium carbonate at 110 °C as 30.6 and 31.9 wt %, respectively, which are in good agreement with data reported previously, using more-complex conventional methods. The method reported here has several advantages, including its simplicity and ease of automation. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158938
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6413-6417[article] Determination of inorganic salt solubility at a temperature above the boiling point of water by multiple headspace extraction gas chromatography [texte imprimé] / Xin-Sheng Chai, Auteur ; Christopher L. Verrill, Auteur . - 2011 . - pp. 6413-6417.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6413-6417
Mots-clés : Gas chromatography Boiling point Solubility Résumé : This paper describes a novel method for the determination of the solubility of sodium carbonate and sodium sulfate in single- and bisalt aqueous solutions at 110 °C, using multiple headspace extraction gas chromatography (MHE-GC). Both benzene alcohol and methanol were used as the tracer compounds whose vapor-liquid equilibrium (VLE) partition coefficients (CV/CL) are related to the concentration of salt in the studied solution, thereby indirectly providing solubility data. During the MHE process, small amounts of water are removed stepwise by a series of headspace vapor extractions, which simulates the evaporation process, resulting in an increase in the salt concentration in the solution and a decrease in the amount of tracer in the headspace vapor. Eventually, the salt concentration reaches saturation (the limit of solubility), a transition point that can be identified experimentally via GC, because of the different behaviors of the tracer loss before and after the salt saturation point. Knowing the salt concentration in the initial solution and gathering data on the amount of water lost in reaching the transition point, we calculated the solubilities of sodium sulfate and sodium carbonate at 110 °C as 30.6 and 31.9 wt %, respectively, which are in good agreement with data reported previously, using more-complex conventional methods. The method reported here has several advantages, including its simplicity and ease of automation. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158938 Exemplaires
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Titre : Admicellar polymerization and mixing in a laboratory dyeing unit-A variant of rocking reactors Type de document : texte imprimé Auteurs : Srinivas Hanumansetty, Auteur ; Pratik Kothary, Auteur ; Nantaya Yanumet, Auteur Année de publication : 2011 Article en page(s) : pp. 6418-6425 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Reactor Mixing Polymerization Résumé : Mass transfer in a laboratory dyeing machine, consisting of cylindrical canisters mounted on a carousel with a horizontal axis, has been examined to adapt the unit for modification of cotton by admicellar polymerization. Canisters located at the periphery of the carousel are canted relative to the axis of rotation so that fluid in the canister moves front-to-back and back-to-front over the course of one revolution in a fashion similar to a rocking reactor. Dissolution of benzoic acid in water at 30 °C has been used to determine mass transfer coefficients β in the dyeing system as a function of rotational rate and fill volume. Mixing in the dyeing system improved with canister fill fraction to an optimum of 0.9, while rotation rate had little effect over the available range. Findings for β as well as predictions for β obtained from estimates of specific mixing power are compared to values from the literature for a rocking reactor. The process of admicellar polymerization on cotton was subsequently examined in the laboratory dyeing machine. Cotton with a water repellent coating prepared in the unit was evaluated using various techniques. Conditions favorable to mass transfer in the model experiments were consistent with those providing optimal performance of the water-repellent coating applied by admicellar polymerization. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158939
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6418-6425[article] Admicellar polymerization and mixing in a laboratory dyeing unit-A variant of rocking reactors [texte imprimé] / Srinivas Hanumansetty, Auteur ; Pratik Kothary, Auteur ; Nantaya Yanumet, Auteur . - 2011 . - pp. 6418-6425.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6418-6425
Mots-clés : Reactor Mixing Polymerization Résumé : Mass transfer in a laboratory dyeing machine, consisting of cylindrical canisters mounted on a carousel with a horizontal axis, has been examined to adapt the unit for modification of cotton by admicellar polymerization. Canisters located at the periphery of the carousel are canted relative to the axis of rotation so that fluid in the canister moves front-to-back and back-to-front over the course of one revolution in a fashion similar to a rocking reactor. Dissolution of benzoic acid in water at 30 °C has been used to determine mass transfer coefficients β in the dyeing system as a function of rotational rate and fill volume. Mixing in the dyeing system improved with canister fill fraction to an optimum of 0.9, while rotation rate had little effect over the available range. Findings for β as well as predictions for β obtained from estimates of specific mixing power are compared to values from the literature for a rocking reactor. The process of admicellar polymerization on cotton was subsequently examined in the laboratory dyeing machine. Cotton with a water repellent coating prepared in the unit was evaluated using various techniques. Conditions favorable to mass transfer in the model experiments were consistent with those providing optimal performance of the water-repellent coating applied by admicellar polymerization. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158939 Exemplaires
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Titre : Determination of interfacial area and overall volumetric mass-transfer oefficient in a novel type of two impinging streams reactor by chemical method Type de document : texte imprimé Auteurs : Asghar Molaei Dehkordi, Auteur ; Chiya Savari, Auteur Année de publication : 2011 Article en page(s) : pp. 6426-6435 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Impinging stream Chemical method Reactor Mass transfer Volumetric mass coefficient Interfacial area Résumé : The theory of mass transfer accompanied by chemical reaction for gas-liquid systems was used to measure the effective interfacial area (a) and the overall volumetric mass-transfer coefficient (kLa) in a new two impinging streams reactor (TISR), which is characterized by ahigh-intensity mixing chamber equipped with two two-phase nozzles directed toward each other. As a result of both the impinging process and high rate shear forces exerted on the gas and liquid phases, the overall volumetric mass-transfer coefficients of up to 0.41 s-1, and the mass-transfer coefficients (kL) of up to 15 × 10-4 m/s have been obtained. In addition, the influences of gas and liquid flow rates on the kLa and a values obtained in the TISR have been investigated. These experimental results verify the capability of the proposed TISR in gas-liquid operations. Furthermore, on the basis of the experimental results obtained, two correlations for both the Sherwood number for the liquid phase (ShL) and the specific interfacial area (a) in terms of Froude, Reynolds, Schmidt, and Morton numbers have been derived. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158940
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6426-6435[article] Determination of interfacial area and overall volumetric mass-transfer oefficient in a novel type of two impinging streams reactor by chemical method [texte imprimé] / Asghar Molaei Dehkordi, Auteur ; Chiya Savari, Auteur . - 2011 . - pp. 6426-6435.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6426-6435
Mots-clés : Impinging stream Chemical method Reactor Mass transfer Volumetric mass coefficient Interfacial area Résumé : The theory of mass transfer accompanied by chemical reaction for gas-liquid systems was used to measure the effective interfacial area (a) and the overall volumetric mass-transfer coefficient (kLa) in a new two impinging streams reactor (TISR), which is characterized by ahigh-intensity mixing chamber equipped with two two-phase nozzles directed toward each other. As a result of both the impinging process and high rate shear forces exerted on the gas and liquid phases, the overall volumetric mass-transfer coefficients of up to 0.41 s-1, and the mass-transfer coefficients (kL) of up to 15 × 10-4 m/s have been obtained. In addition, the influences of gas and liquid flow rates on the kLa and a values obtained in the TISR have been investigated. These experimental results verify the capability of the proposed TISR in gas-liquid operations. Furthermore, on the basis of the experimental results obtained, two correlations for both the Sherwood number for the liquid phase (ShL) and the specific interfacial area (a) in terms of Froude, Reynolds, Schmidt, and Morton numbers have been derived. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158940 Exemplaires
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Titre : Modeling gas solubilities in the aqueous solution of methyldiethanolamine Type de document : texte imprimé Auteurs : Ying Zhang, Auteur ; Chau-Chyun Chen, Auteur Année de publication : 2011 Article en page(s) : pp. 6436-6446 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Aqueous solution Solubility Modeling Résumé : A thermodynamically consistent model recently developed for representing CO2 solubility in aqueous solutions of methyldiethanolamine is extended to include H2S and lower hydrocarbons. The electrolyte-nonrandom two-liquid (NRTL) activity coefficient model and the PC-SAFT equation of state are used to represent the liquid phase and the vapor phase nonideality, respectively. The Henry's constant of H2S in water is fitted to the total pressure data of the H2S-H2O binary system. The NRTL binary interaction parameters of the solvent-electrolyte binaries are regressed with the VLE data of the H2S-H2O-MDEA ternary system. The differential heat of H2S absorption of the H2S-H2O-MDEA ternary system and the partial pressures of H2S and CO2 of the H2S-CO2-H2O-MDEA quaternary system are predicted and compared favorably to the experimental data. The Henry's constants of light hydrocarbons in water and MDEA are also determined by fitting the total pressure data of the hydrocarbon-H2O binary and the hydrocarbon-H2O-MDEA ternary systems. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158941
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6436-6446[article] Modeling gas solubilities in the aqueous solution of methyldiethanolamine [texte imprimé] / Ying Zhang, Auteur ; Chau-Chyun Chen, Auteur . - 2011 . - pp. 6436-6446.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6436-6446
Mots-clés : Aqueous solution Solubility Modeling Résumé : A thermodynamically consistent model recently developed for representing CO2 solubility in aqueous solutions of methyldiethanolamine is extended to include H2S and lower hydrocarbons. The electrolyte-nonrandom two-liquid (NRTL) activity coefficient model and the PC-SAFT equation of state are used to represent the liquid phase and the vapor phase nonideality, respectively. The Henry's constant of H2S in water is fitted to the total pressure data of the H2S-H2O binary system. The NRTL binary interaction parameters of the solvent-electrolyte binaries are regressed with the VLE data of the H2S-H2O-MDEA ternary system. The differential heat of H2S absorption of the H2S-H2O-MDEA ternary system and the partial pressures of H2S and CO2 of the H2S-CO2-H2O-MDEA quaternary system are predicted and compared favorably to the experimental data. The Henry's constants of light hydrocarbons in water and MDEA are also determined by fitting the total pressure data of the hydrocarbon-H2O binary and the hydrocarbon-H2O-MDEA ternary systems. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158941 Exemplaires
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Titre : Investigation of water diffusion in low-density polyethylene by attenuated total reflectance fourier transform infrared spectroscopy and two-dimensional correlation analysis Type de document : texte imprimé Auteurs : Mengyin Wang, Auteur ; Peiyi Wu, Auteur ; Saurav S. Sengupta, Auteur Année de publication : 2011 Article en page(s) : pp. 6447-6454 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Correlation analysis Fourier-transformed infrared spectrometry Reflectance Density Diffusion Résumé : Water diffusion through low density polyethylene (LDPE) film was investigated by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and two-dimensional correlation spectroscopy (2DCOS) over a temperature range of 25-80 °C. The 2DCOS spectra of water diffusion in LDPE at different temperatures were very similar. The broad OH stretching vibration (v(OH)) was split into four bands assigned to three different types of water molecules, namely, bulk water, cluster water, and free water, which will be defined. It appeared that as water molecules disperse in LDPE, cluster water with moderate hydrogen bonds diffused faster than bulk water with strong hydrogen bonds. Additionally, the hydrogen bonds between water molecules may have been further weakened or even broken to form free water, possibly due to limited free volume. On the basis of a Fickian model, the diffusion coefficients could be calculated from overall, fast and slow diffusion process, respectively. The diffusion coefficients were observed to increase with temperature, possibly due to increased swelling of molecular chain, more free volume, and reduced size of the penetrants. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158942
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6447-6454[article] Investigation of water diffusion in low-density polyethylene by attenuated total reflectance fourier transform infrared spectroscopy and two-dimensional correlation analysis [texte imprimé] / Mengyin Wang, Auteur ; Peiyi Wu, Auteur ; Saurav S. Sengupta, Auteur . - 2011 . - pp. 6447-6454.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6447-6454
Mots-clés : Correlation analysis Fourier-transformed infrared spectrometry Reflectance Density Diffusion Résumé : Water diffusion through low density polyethylene (LDPE) film was investigated by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy and two-dimensional correlation spectroscopy (2DCOS) over a temperature range of 25-80 °C. The 2DCOS spectra of water diffusion in LDPE at different temperatures were very similar. The broad OH stretching vibration (v(OH)) was split into four bands assigned to three different types of water molecules, namely, bulk water, cluster water, and free water, which will be defined. It appeared that as water molecules disperse in LDPE, cluster water with moderate hydrogen bonds diffused faster than bulk water with strong hydrogen bonds. Additionally, the hydrogen bonds between water molecules may have been further weakened or even broken to form free water, possibly due to limited free volume. On the basis of a Fickian model, the diffusion coefficients could be calculated from overall, fast and slow diffusion process, respectively. The diffusion coefficients were observed to increase with temperature, possibly due to increased swelling of molecular chain, more free volume, and reduced size of the penetrants. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158942 Exemplaires
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Titre : Study of gas hydrate formation in the carbon dioxide + hydrogen + water systems : Compositional Analysis of the gas phase Type de document : texte imprimé Auteurs : Veronica Belandria, Auteur ; Ali Eslamimanesh, Auteur ; Amir H. Mohammadi, Auteur Année de publication : 2011 Article en page(s) : pp. 6455-6459 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Carbon dioxide Gas hydrates Résumé : Molar compositions of carbon dioxide (and hydrogen) in the gas phase in equilibrium with gas hydrate and aqueous phases were measured for various (H2 + CO2) gas mixtures + water systems in the temperature range of 273.6-281.2 K at pressures up to ~9 MPa. The compositions of the gas phase were measured using an isochoric technique, in combination with the ROLSI capillary gas-phase sampling and a gas chromatography technique. The compositional data generated in this work are compared with the literature data, and the agreement is found to be generally acceptable. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158943
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6455-6459[article] Study of gas hydrate formation in the carbon dioxide + hydrogen + water systems : Compositional Analysis of the gas phase [texte imprimé] / Veronica Belandria, Auteur ; Ali Eslamimanesh, Auteur ; Amir H. Mohammadi, Auteur . - 2011 . - pp. 6455-6459.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6455-6459
Mots-clés : Carbon dioxide Gas hydrates Résumé : Molar compositions of carbon dioxide (and hydrogen) in the gas phase in equilibrium with gas hydrate and aqueous phases were measured for various (H2 + CO2) gas mixtures + water systems in the temperature range of 273.6-281.2 K at pressures up to ~9 MPa. The compositions of the gas phase were measured using an isochoric technique, in combination with the ROLSI capillary gas-phase sampling and a gas chromatography technique. The compositional data generated in this work are compared with the literature data, and the agreement is found to be generally acceptable. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158943 Exemplaires
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Titre : An equation of state for the isotropic-nematic phase transition of semiflexible polymers Type de document : texte imprimé Auteurs : Yuan-Xiang Zheng, Auteur ; Yang-Xin Yu, Auteur ; Ying-Feng Li, Auteur Année de publication : 2011 Article en page(s) : pp. 6460-6469 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Thermodynamic properties Phase transitions Equations of state Résumé : Based on the thermodynamic perturbation theory for polymer, a new equation is proposed by incorporating a wide range of molecular flexibility and perturbative interactions to describe the isotropic-anisobupic (nematic) phase transition phenomena of the semiflexible polymers. In the new equation, the framework of the Helmholtz free energy of the system is the same as the Onsager-like theory. The entropy loss due to the orientation is estimated by the Khokhlov-Semenov (KS) theory. With regard to the configurational free energy, the polymer is envisioned as a series of subchains. The Parsons-Lee approximation is used to account for the higher virial coefficients of the subchain and Yu equation for the hard-sphere-chain fluid is adopted to modify the defect of the first order approximation in dealing with the associating points. An analytical expression of the perturbative term is obtained by employing the "square peg in a round hole" potential function and the mean-field approximation. The hard-core part of the equation reduces to the Dupre-Yang theory when the stiffness of the molecule is high. When the model approaches the limit of the random coil, a modified equation of the hard-sphere-chain fluid is obtained. The present theory has been used to predict the isotropic-nematic phase equilibrium for real semiflexible polymers with two adjustable parameters. The agreements between the theoretical results and experimental data are much better than that of previous theories. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158944
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6460-6469[article] An equation of state for the isotropic-nematic phase transition of semiflexible polymers [texte imprimé] / Yuan-Xiang Zheng, Auteur ; Yang-Xin Yu, Auteur ; Ying-Feng Li, Auteur . - 2011 . - pp. 6460-6469.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6460-6469
Mots-clés : Thermodynamic properties Phase transitions Equations of state Résumé : Based on the thermodynamic perturbation theory for polymer, a new equation is proposed by incorporating a wide range of molecular flexibility and perturbative interactions to describe the isotropic-anisobupic (nematic) phase transition phenomena of the semiflexible polymers. In the new equation, the framework of the Helmholtz free energy of the system is the same as the Onsager-like theory. The entropy loss due to the orientation is estimated by the Khokhlov-Semenov (KS) theory. With regard to the configurational free energy, the polymer is envisioned as a series of subchains. The Parsons-Lee approximation is used to account for the higher virial coefficients of the subchain and Yu equation for the hard-sphere-chain fluid is adopted to modify the defect of the first order approximation in dealing with the associating points. An analytical expression of the perturbative term is obtained by employing the "square peg in a round hole" potential function and the mean-field approximation. The hard-core part of the equation reduces to the Dupre-Yang theory when the stiffness of the molecule is high. When the model approaches the limit of the random coil, a modified equation of the hard-sphere-chain fluid is obtained. The present theory has been used to predict the isotropic-nematic phase equilibrium for real semiflexible polymers with two adjustable parameters. The agreements between the theoretical results and experimental data are much better than that of previous theories. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158944 Exemplaires
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Titre : Specific heat capacity of pure water at 4.0 MPa between 298.15 and 465.65 K Type de document : texte imprimé Auteurs : Joan J. Manya, Auteur ; Michael Jerry Antal, Auteur ; Christopher K. Kinoshita, Auteur Année de publication : 2011 Article en page(s) : pp. 6470-6484 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Heat capacity Specific heat Résumé : The present work reports experimental results concerning the specific isobaric heat capacity of pure water at elevated pressure. Experiments were performed using a Tian-Calvet differential scanning calorimeter (Setaram Model BT2.15), at temperatures ranging from 298.15 to 465.65 K and at a constant pressure of 4.0 MPa. The aim of this study is to compare the new experimental results with values predicted by the LAPWS-95 formulation, which is generally accepted as reliable by the scientific community despite the fact that, in this formulation, nearly all the data for the isobaric heat capacity of water are based on measurements of Sirota's group in the former Soviet Union in the period from 1956 to 1970. The present calorimetric results for the specific heat capacity of pure water were found to be substantially in disagreement with the values obtained using the IAPWS-95 formulation, especially at high temperatures, where the differences are greater thanSpecific heat 20%. Additional studies are therefore warranted in order to confirm this discrepancy. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158945
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6470-6484[article] Specific heat capacity of pure water at 4.0 MPa between 298.15 and 465.65 K [texte imprimé] / Joan J. Manya, Auteur ; Michael Jerry Antal, Auteur ; Christopher K. Kinoshita, Auteur . - 2011 . - pp. 6470-6484.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6470-6484
Mots-clés : Heat capacity Specific heat Résumé : The present work reports experimental results concerning the specific isobaric heat capacity of pure water at elevated pressure. Experiments were performed using a Tian-Calvet differential scanning calorimeter (Setaram Model BT2.15), at temperatures ranging from 298.15 to 465.65 K and at a constant pressure of 4.0 MPa. The aim of this study is to compare the new experimental results with values predicted by the LAPWS-95 formulation, which is generally accepted as reliable by the scientific community despite the fact that, in this formulation, nearly all the data for the isobaric heat capacity of water are based on measurements of Sirota's group in the former Soviet Union in the period from 1956 to 1970. The present calorimetric results for the specific heat capacity of pure water were found to be substantially in disagreement with the values obtained using the IAPWS-95 formulation, especially at high temperatures, where the differences are greater thanSpecific heat 20%. Additional studies are therefore warranted in order to confirm this discrepancy. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158945 Exemplaires
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Titre : Performance evaluation and neural modeling of gas-phase styrene removal in one- and two-liquid phase suspended-growth bioreactors Type de document : texte imprimé Auteurs : Eldon R. Rene, Auteur ; Maria C. Veiga, Auteur ; Christian Kennes, Auteur Année de publication : 2011 Article en page(s) : pp. 6485–6495 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Bioreactors Résumé : The removal of gas-phase styrene was studied in both one- and two-liquid phase continuous stirred tank bioreactors (CSTBs) inoculated with Sporothrix variecibatus. Experiments were carried out at different gas residence times and inlet styrene concentrations to reach inlet loading rates varying between 10 and 838 g m−3 h−1 in the bioreactors. The addition of 10% (v/v) silicone oil acted as a buffer for high styrene loads and improved the two-liquid phase CSTB performance 3.1-fold in comparison to the one-liquid phase CSTB, with maximum elimination capacities of 426 and 137 g m−3 h−1, respectively. The CSTBs performance was modeled using artificial neural networks (ANNs) with inlet concentration (g m−3) and unit flow (h−1) as the input variables. The best network topology, selected by a trial and error approach and by estimating the determination coefficient (R2) values, was found to be 2−5−1 and 2−6−1, respectively, for the one- and two-liquid phase CSTB. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102523j
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6485–6495[article] Performance evaluation and neural modeling of gas-phase styrene removal in one- and two-liquid phase suspended-growth bioreactors [texte imprimé] / Eldon R. Rene, Auteur ; Maria C. Veiga, Auteur ; Christian Kennes, Auteur . - 2011 . - pp. 6485–6495.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6485–6495
Mots-clés : Bioreactors Résumé : The removal of gas-phase styrene was studied in both one- and two-liquid phase continuous stirred tank bioreactors (CSTBs) inoculated with Sporothrix variecibatus. Experiments were carried out at different gas residence times and inlet styrene concentrations to reach inlet loading rates varying between 10 and 838 g m−3 h−1 in the bioreactors. The addition of 10% (v/v) silicone oil acted as a buffer for high styrene loads and improved the two-liquid phase CSTB performance 3.1-fold in comparison to the one-liquid phase CSTB, with maximum elimination capacities of 426 and 137 g m−3 h−1, respectively. The CSTBs performance was modeled using artificial neural networks (ANNs) with inlet concentration (g m−3) and unit flow (h−1) as the input variables. The best network topology, selected by a trial and error approach and by estimating the determination coefficient (R2) values, was found to be 2−5−1 and 2−6−1, respectively, for the one- and two-liquid phase CSTB. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie102523j Exemplaires
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Titre : Microalgae capture of CO2 from actual flue gas discharged from a combustion chamber Type de document : texte imprimé Auteurs : Fang-Fang Li, Auteur ; Zhong-Hua Yang, Auteur ; Rong Zeng, Auteur Année de publication : 2011 Article en page(s) : pp. 6496-6502 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Combustion chamber Gaseous effluent Carbon dioxide Résumé : Fixation CO2 with microalgae is a potential promising technique to reduce CO2 emission for its various advantages. In this work, we develop a microalgal fixation CO2 system to capture CO2 from actual flue gas. At first, we evolved a strain Scenedesmus obliquus, named S. obliquus WUST4, with a UV mutagenesis technique, which can endure actual flue gas. The S. obliquus WUST4 can tolerate high concentration CO2, and possesses high CO2 fixation ability. Then, we developed a pilot scale microalgal fixation CO2 system to capture CO2 from actual flue gas with the evolved S. obliquus WUST4. The flue gas was discharged from the combustion chamber in a coke oven. A 100 L air-lift photobioreactor was built in this system. In the pilot scale system, CO2 can be captured from the actual flue gas by the S. obliquus WUST4. The CO2 removal ratio can reach 67% with the optimal operation conditions. This provides an efficient technique for CO2 capture. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158947
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6496-6502[article] Microalgae capture of CO2 from actual flue gas discharged from a combustion chamber [texte imprimé] / Fang-Fang Li, Auteur ; Zhong-Hua Yang, Auteur ; Rong Zeng, Auteur . - 2011 . - pp. 6496-6502.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6496-6502
Mots-clés : Combustion chamber Gaseous effluent Carbon dioxide Résumé : Fixation CO2 with microalgae is a potential promising technique to reduce CO2 emission for its various advantages. In this work, we develop a microalgal fixation CO2 system to capture CO2 from actual flue gas. At first, we evolved a strain Scenedesmus obliquus, named S. obliquus WUST4, with a UV mutagenesis technique, which can endure actual flue gas. The S. obliquus WUST4 can tolerate high concentration CO2, and possesses high CO2 fixation ability. Then, we developed a pilot scale microalgal fixation CO2 system to capture CO2 from actual flue gas with the evolved S. obliquus WUST4. The flue gas was discharged from the combustion chamber in a coke oven. A 100 L air-lift photobioreactor was built in this system. In the pilot scale system, CO2 can be captured from the actual flue gas by the S. obliquus WUST4. The CO2 removal ratio can reach 67% with the optimal operation conditions. This provides an efficient technique for CO2 capture. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158947 Exemplaires
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Titre : Prediction of vaporization enthalpy of pure compounds using a group contribution-based method Type de document : texte imprimé Auteurs : Farhad Gharagheizi, Auteur ; Omid Babaie, Auteur ; Sahar Mazdeyasna, Auteur Année de publication : 2011 Article en page(s) : pp. 6503-6507 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Thermodynamic properties Enthalpy Vaporization Prediction Résumé : In this work, the artificial neural network-group contribution (ANN-GC) method is applied to estimate the vaporization enthalpy of pure chemical compounds at their normal boiling point. A group of 4907 pure compounds from various chemical families are investigated to propose a comprehensive and predictive model. The obtained results show the squared correlation coeffident (R2) of 0.993, root mean square error of 1.1 kJ/mol, and average absolute deviation lower than 1.5% for the estimated properties from existing experimental values. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158948
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6503-6507[article] Prediction of vaporization enthalpy of pure compounds using a group contribution-based method [texte imprimé] / Farhad Gharagheizi, Auteur ; Omid Babaie, Auteur ; Sahar Mazdeyasna, Auteur . - 2011 . - pp. 6503-6507.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6503-6507
Mots-clés : Thermodynamic properties Enthalpy Vaporization Prediction Résumé : In this work, the artificial neural network-group contribution (ANN-GC) method is applied to estimate the vaporization enthalpy of pure chemical compounds at their normal boiling point. A group of 4907 pure compounds from various chemical families are investigated to propose a comprehensive and predictive model. The obtained results show the squared correlation coeffident (R2) of 0.993, root mean square error of 1.1 kJ/mol, and average absolute deviation lower than 1.5% for the estimated properties from existing experimental values. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158948 Exemplaires
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Titre : Measurements of local nusselt number with a miniscale laminar confined slot-Jet impinging on a flat plate Type de document : texte imprimé Auteurs : Dae Hee Lee, Auteur Année de publication : 2011 Article en page(s) : pp. 6508-6512 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Flat plate Nusselt number Résumé : Heat transfer characteristics in a miniscale laminar confined slot-jet on a heated plate at uniform heat flux are experimentally investigated. The effects of the jet Reynolds number (Re = 120-180) on the heat transfer and flow are considered. An electrically heated gold film Intrex (a very thin gold-coated polyester substrate sheet) is used to create a uniform heat flux on the flat surface. The temperature on the surface is measured by thermochromic liquid crystals and a digital color image processing system. Recorded color images of liquid crystals are then used to determine the local Nusselt numbers along the surface. The results show a peculiar behavior in that the Nusselt number increases between Re = 120 and Re = 140, suddenly drops at around Re = 150-160, and increases again beyond Re = 160. This sudden drop of Nusselt number at around Re = 150-160 may be caused by a sinusoidal fluctuation of the jet flow. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158949
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6508-6512[article] Measurements of local nusselt number with a miniscale laminar confined slot-Jet impinging on a flat plate [texte imprimé] / Dae Hee Lee, Auteur . - 2011 . - pp. 6508-6512.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6508-6512
Mots-clés : Flat plate Nusselt number Résumé : Heat transfer characteristics in a miniscale laminar confined slot-jet on a heated plate at uniform heat flux are experimentally investigated. The effects of the jet Reynolds number (Re = 120-180) on the heat transfer and flow are considered. An electrically heated gold film Intrex (a very thin gold-coated polyester substrate sheet) is used to create a uniform heat flux on the flat surface. The temperature on the surface is measured by thermochromic liquid crystals and a digital color image processing system. Recorded color images of liquid crystals are then used to determine the local Nusselt numbers along the surface. The results show a peculiar behavior in that the Nusselt number increases between Re = 120 and Re = 140, suddenly drops at around Re = 150-160, and increases again beyond Re = 160. This sudden drop of Nusselt number at around Re = 150-160 may be caused by a sinusoidal fluctuation of the jet flow. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158949 Exemplaires
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Titre : Direct oxidation of methane to a methanol derivative using molecular oxygen Type de document : texte imprimé Auteurs : Jiongliang Yuan, Auteur ; Lanlan Wang, Auteur ; Yan Wang, Auteur Année de publication : 2011 Article en page(s) : pp. 6513-6516 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Oxidation Résumé : A direct selective oxidation of methane to a methanol derivative with the catalysis of palladium acetate/ benzoquinone/molybdovanado-phosphoric acid using molecular oxygen in trifluoroacetic acid has been suggested. Methyl trifluoroacetate is the only liquid product, and its highest yield could be obtained at 80-100 °C. The addition of perfluorooctane could improve the yield of methyl trifluoroacetate significantly. The reaction product can be easily separated from the reaction system, using the difference of boiling points. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158950
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6513-6516[article] Direct oxidation of methane to a methanol derivative using molecular oxygen [texte imprimé] / Jiongliang Yuan, Auteur ; Lanlan Wang, Auteur ; Yan Wang, Auteur . - 2011 . - pp. 6513-6516.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 10 (Mai 2011) . - pp. 6513-6516
Mots-clés : Oxidation Résumé : A direct selective oxidation of methane to a methanol derivative with the catalysis of palladium acetate/ benzoquinone/molybdovanado-phosphoric acid using molecular oxygen in trifluoroacetic acid has been suggested. Methyl trifluoroacetate is the only liquid product, and its highest yield could be obtained at 80-100 °C. The addition of perfluorooctane could improve the yield of methyl trifluoroacetate significantly. The reaction product can be easily separated from the reaction system, using the difference of boiling points. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24158950 Exemplaires
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