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Vol. 51 N° 21 - Mai 2012 [texte imprimé] . - 2012 . - p. 7137-7456 : ill. ; 28 cm. Chemical engineering Langues : Anglais (eng)
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Ajouter le résultat dans votre panierCharacterization of Oxygen Scavenging Films Based on 1,4-Polybutadiene / Hua Li in Industrial & engineering chemistry research, Vol. 51 N° 21 (Mai 2012)
Titre : Characterization of Oxygen Scavenging Films Based on 1,4-Polybutadiene Type de document : texte imprimé Auteurs : Hua Li, Auteur ; Kevin K. Tung, Auteur ; D. R. Paul, Auteur Année de publication : 2012 Article en page(s) : pp. 7138-7145 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Polybutadiene Résumé : To better characterize the fundamentals of oxygen scavenging as a means to prepare high oxygen barrier polymer films, the oxidation of 1,4-polybutadiene, in the presence of a transition metal salt catalyst, cobalt neodecanoate, was studied at 30 °C. Oxygen uptake of 1,4-polybutadiene films was measured as a function of cobalt neodecanoate concentration. In these samples, oxygen mass uptake values as high as 15 wt % were observed, and the kinetics of oxidation were of the order of 10 days. Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis suggest that the oxidation was heterogeneous, with the film surface being highly oxidized and the film center being less oxidized. Interestingly, the oxygen uptake exhibited a maximum with catalyst loading, which is believed to be related to the heterogeneous nature of the oxidation process. Since antioxidants are typically added during the industrial scale preparation and the amount of antioxidants would affect the oxygen mass uptake value and oxidation kinetics, the importance of an antioxidant removal method and a normalized purification strategy were determined prior to oxygen uptake experiments. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201905j
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7138-7145[article] Characterization of Oxygen Scavenging Films Based on 1,4-Polybutadiene [texte imprimé] / Hua Li, Auteur ; Kevin K. Tung, Auteur ; D. R. Paul, Auteur . - 2012 . - pp. 7138-7145.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7138-7145
Mots-clés : Polybutadiene Résumé : To better characterize the fundamentals of oxygen scavenging as a means to prepare high oxygen barrier polymer films, the oxidation of 1,4-polybutadiene, in the presence of a transition metal salt catalyst, cobalt neodecanoate, was studied at 30 °C. Oxygen uptake of 1,4-polybutadiene films was measured as a function of cobalt neodecanoate concentration. In these samples, oxygen mass uptake values as high as 15 wt % were observed, and the kinetics of oxidation were of the order of 10 days. Fourier transform infrared (FTIR) and X-ray photoelectron spectroscopy (XPS) analysis suggest that the oxidation was heterogeneous, with the film surface being highly oxidized and the film center being less oxidized. Interestingly, the oxygen uptake exhibited a maximum with catalyst loading, which is believed to be related to the heterogeneous nature of the oxidation process. Since antioxidants are typically added during the industrial scale preparation and the amount of antioxidants would affect the oxygen mass uptake value and oxidation kinetics, the importance of an antioxidant removal method and a normalized purification strategy were determined prior to oxygen uptake experiments. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201905j Exemplaires
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Titre : Thermal treatment of dredged sediment in a rotary kiln : Investigation of structural changes Type de document : texte imprimé Auteurs : Jocelyn Ramaroson, Auteur ; Moussa Dia, Auteur ; Jean-Louis Dirion, Auteur Année de publication : 2012 Article en page(s) : pp. 7146-7152 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Rotary kiln Sediments Heat treatment Résumé : Sediment deposits cause the silting of channels, rivers, and lakes. This completely natural phenomenon is exacerbated by the introduction of industrial and urban wastes into the erosion and sedimentation process. Other problems then appear, such as an increased risk of flooding, a reduced capacity for biological purification, and an associated loss of biodiversity. The presence of toxic compounds in the sediments (of industrial, household, or agricultural origin) worsens the situation, and measures must be taken to restore the natural environmental conditions and processes. This study assesses the technology of treating heavy metals from dredged sediments using phosphoric acid (the NOVOSOL process, which was developed by SOLVAY), which aims to convert metals, mainly Pb, Cd, Zn, and Cu, into insoluble metallic phosphates, and (by calcination) to engineer the properties of the final residues for beneficial use. The effectiveness of this treatment was evaluated by creating the chemical reaction, followed by convective drying and maturation of the treated sediment at ambient temperature, and finally by calcination (400—1000 °C). This paper focuses on the study of the decomposition of organics and structural change in the sediment during thermal treatment in a rotary kiln. The results showed that the specific surface, the particle size, and the total organic of the sediment are dependent on the calcination parameters such as the residence time, the calcination temperature, and the flow rate. The degradation of the organic compounds is effective at 600 °C. An increase in specific surface is observed until 600 °C, followed by a significant reduction accompanied by a densification and growth of particles. This increase in specific surface area observed attributed to the formation of pores due mainly to the decomposition of organics and the gas evolve (CO2, H2O, ...) from 600 °C to 900 °C. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948454
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7146-7152[article] Thermal treatment of dredged sediment in a rotary kiln : Investigation of structural changes [texte imprimé] / Jocelyn Ramaroson, Auteur ; Moussa Dia, Auteur ; Jean-Louis Dirion, Auteur . - 2012 . - pp. 7146-7152.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7146-7152
Mots-clés : Rotary kiln Sediments Heat treatment Résumé : Sediment deposits cause the silting of channels, rivers, and lakes. This completely natural phenomenon is exacerbated by the introduction of industrial and urban wastes into the erosion and sedimentation process. Other problems then appear, such as an increased risk of flooding, a reduced capacity for biological purification, and an associated loss of biodiversity. The presence of toxic compounds in the sediments (of industrial, household, or agricultural origin) worsens the situation, and measures must be taken to restore the natural environmental conditions and processes. This study assesses the technology of treating heavy metals from dredged sediments using phosphoric acid (the NOVOSOL process, which was developed by SOLVAY), which aims to convert metals, mainly Pb, Cd, Zn, and Cu, into insoluble metallic phosphates, and (by calcination) to engineer the properties of the final residues for beneficial use. The effectiveness of this treatment was evaluated by creating the chemical reaction, followed by convective drying and maturation of the treated sediment at ambient temperature, and finally by calcination (400—1000 °C). This paper focuses on the study of the decomposition of organics and structural change in the sediment during thermal treatment in a rotary kiln. The results showed that the specific surface, the particle size, and the total organic of the sediment are dependent on the calcination parameters such as the residence time, the calcination temperature, and the flow rate. The degradation of the organic compounds is effective at 600 °C. An increase in specific surface is observed until 600 °C, followed by a significant reduction accompanied by a densification and growth of particles. This increase in specific surface area observed attributed to the formation of pores due mainly to the decomposition of organics and the gas evolve (CO2, H2O, ...) from 600 °C to 900 °C. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948454 Exemplaires
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Titre : Enzymatic Digestibility of Corn Stover Fractions in Response to Fungal Pretreatment Type de document : texte imprimé Auteurs : Zhifang Cui, Auteur ; Caixia Wan, Auteur ; Jian Shi, Auteur Année de publication : 2012 Article en page(s) : pp. 7153–7159 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Enzymatic digestibility Résumé : Corn stover fractions (leaves, cobs, and stalks) were studied for enzymatic digestibility after pretreatment with a white rot fungus, Ceriporiopsis subvermispora. Among the three fractions, leaves had the least recalcitrance to fungal pretreatment and the lignin degradation reached 45% after 30 days of pretreatment. The lignin degradation of stalks and cobs was similar but was significantly lower than that of leaves (p ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300487z
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7153–7159[article] Enzymatic Digestibility of Corn Stover Fractions in Response to Fungal Pretreatment [texte imprimé] / Zhifang Cui, Auteur ; Caixia Wan, Auteur ; Jian Shi, Auteur . - 2012 . - pp. 7153–7159.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7153–7159
Mots-clés : Enzymatic digestibility Résumé : Corn stover fractions (leaves, cobs, and stalks) were studied for enzymatic digestibility after pretreatment with a white rot fungus, Ceriporiopsis subvermispora. Among the three fractions, leaves had the least recalcitrance to fungal pretreatment and the lignin degradation reached 45% after 30 days of pretreatment. The lignin degradation of stalks and cobs was similar but was significantly lower than that of leaves (p ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300487z Exemplaires
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Titre : Concise cuI - catalyzed azide – alkyne 1,3 - dipolar cycloaddition reaction ligation remarkably enhances the corrosion inhibitive potency of natural amino acids for mild steel in HCl Type de document : texte imprimé Auteurs : Qiong Deng, Auteur ; Xiao-Peng He, Auteur ; Hong-Wei Shi, Auteur Année de publication : 2012 Article en page(s) : pp. 7160-7169 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Mild steel Corrosion Catalytic reaction Résumé : Despite natural amino acids having been proposed as the green surrogate of currently used corrosion inhibitors that are generally toxic to both nature and human body during the everyday industrial processing of metallic equipments, their structural simplicity yet lowers the inhibitive potency, thereby hampering their further industrialization. We disclose here that a concise chemical ligation (CuI-catalyzed azide―alkyne 1,3-dipolar cycloaddition reaction [Cue-AAC]) between two L-amino acids that are weak or noncorrosion inhibitors may result in their largely improved protective effect for mild steel in HCl. A series of 1,4-disubstituted 1,2,3-triazolyl bis-amino acid derivatives constituted by L-serine, L-threonine, L-phenylalanine, and L-tyrosine were efficiently synthesized via Cue-AAC and deprotection reactions in high yields. Subsequently performed electrochemical impedance spectroscopy (EIS) evidenced that the inhibitive effect of these compounds for mild steel in 1 M HCl is markedly better than that of their natural amino acid counterparts. The inhibitive modality of the most potent inhibitor was interpreted in detail by potentiodynamic polarization and thermodynamic calculations. Furthermore, quantum chemical calculations suggest that the triazole ring formed by the Cue-AAC has contribution to their metal surface adsorption. This study would offer unique insights into the facile development of potency-enhanced green corrosion inhibitors based on the concise Cue-AAC ligation of natural amino acids. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948456
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7160-7169[article] Concise cuI - catalyzed azide – alkyne 1,3 - dipolar cycloaddition reaction ligation remarkably enhances the corrosion inhibitive potency of natural amino acids for mild steel in HCl [texte imprimé] / Qiong Deng, Auteur ; Xiao-Peng He, Auteur ; Hong-Wei Shi, Auteur . - 2012 . - pp. 7160-7169.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7160-7169
Mots-clés : Mild steel Corrosion Catalytic reaction Résumé : Despite natural amino acids having been proposed as the green surrogate of currently used corrosion inhibitors that are generally toxic to both nature and human body during the everyday industrial processing of metallic equipments, their structural simplicity yet lowers the inhibitive potency, thereby hampering their further industrialization. We disclose here that a concise chemical ligation (CuI-catalyzed azide―alkyne 1,3-dipolar cycloaddition reaction [Cue-AAC]) between two L-amino acids that are weak or noncorrosion inhibitors may result in their largely improved protective effect for mild steel in HCl. A series of 1,4-disubstituted 1,2,3-triazolyl bis-amino acid derivatives constituted by L-serine, L-threonine, L-phenylalanine, and L-tyrosine were efficiently synthesized via Cue-AAC and deprotection reactions in high yields. Subsequently performed electrochemical impedance spectroscopy (EIS) evidenced that the inhibitive effect of these compounds for mild steel in 1 M HCl is markedly better than that of their natural amino acid counterparts. The inhibitive modality of the most potent inhibitor was interpreted in detail by potentiodynamic polarization and thermodynamic calculations. Furthermore, quantum chemical calculations suggest that the triazole ring formed by the Cue-AAC has contribution to their metal surface adsorption. This study would offer unique insights into the facile development of potency-enhanced green corrosion inhibitors based on the concise Cue-AAC ligation of natural amino acids. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948456 Exemplaires
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Titre : Aging of water from steam - assisted gravity drainage (SAGD) operations due to air exposure and effects on ceramic membrane filtration Type de document : texte imprimé Auteurs : Anthony Y. Ku, Auteur ; Claire S. Henderson, Auteur ; Matthew A. Petersen, Auteur Année de publication : 2012 Article en page(s) : pp. 7170-7176 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Membrane separation filtration Ceramic materials Inorganic membrane Water vapor Résumé : The performance of first generation steam assisted gravity drainage (SAGD) plants for bitumen recovery has improved through operational experience, but there remain ample opportunities for the introduction of technologies that can further improve energy efficiency and plant reliability. Laboratory testing and validation is an important initial step in technology development A major factor that determines the applicability and validity of testing results is the integrity of process water samples used in lab and field studies for this purpose. The results presented in this paper demonstrate aging of SAGD process water and its direct implication on membrane performance testing. Aging in samples collected after primary bitumen/water separation occurred mainly through reactions of dissolved organic species with air. This resulted in a gradual change in appearance, accompanied by a significantly higher tendency to foul membranes in dead-end filtration tests. The root cause for this change was proposed to be the reaction of phenolic species with oxygen, leading to more compressible and tightly packed filter cakes on the membrane surface. This effect was mitigated by minimizing air exposure during sample collection and handling. These results establish that preventing oxygen exposure to the sample is critical for maintaining sample integrity during a test program. Although this study focuses on filtration, aging effects can also lead to misleading results in laboratory testing of other water treatment processes and must be carefully considered during technology evaluation and development. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948457
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7170-7176[article] Aging of water from steam - assisted gravity drainage (SAGD) operations due to air exposure and effects on ceramic membrane filtration [texte imprimé] / Anthony Y. Ku, Auteur ; Claire S. Henderson, Auteur ; Matthew A. Petersen, Auteur . - 2012 . - pp. 7170-7176.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7170-7176
Mots-clés : Membrane separation filtration Ceramic materials Inorganic membrane Water vapor Résumé : The performance of first generation steam assisted gravity drainage (SAGD) plants for bitumen recovery has improved through operational experience, but there remain ample opportunities for the introduction of technologies that can further improve energy efficiency and plant reliability. Laboratory testing and validation is an important initial step in technology development A major factor that determines the applicability and validity of testing results is the integrity of process water samples used in lab and field studies for this purpose. The results presented in this paper demonstrate aging of SAGD process water and its direct implication on membrane performance testing. Aging in samples collected after primary bitumen/water separation occurred mainly through reactions of dissolved organic species with air. This resulted in a gradual change in appearance, accompanied by a significantly higher tendency to foul membranes in dead-end filtration tests. The root cause for this change was proposed to be the reaction of phenolic species with oxygen, leading to more compressible and tightly packed filter cakes on the membrane surface. This effect was mitigated by minimizing air exposure during sample collection and handling. These results establish that preventing oxygen exposure to the sample is critical for maintaining sample integrity during a test program. Although this study focuses on filtration, aging effects can also lead to misleading results in laboratory testing of other water treatment processes and must be carefully considered during technology evaluation and development. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948457 Exemplaires
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Titre : Pilot - scale study of CO2 capture by CaO - based sorbents in the presence of steam and SO2 Type de document : texte imprimé Auteurs : Robert T. Symonds, Auteur ; Dennis Y. Lu, Auteur ; Vasilije Manovic, Auteur Année de publication : 2012 Article en page(s) : pp. 7177-7184 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Water vapor Carbon dioxide Résumé : Calcium looping cycles require an oxy-fired calciner burning coal for sorbent regeneration. Thus, in addition to O2 and CO2, the flue gases will include both steam and SO2, and similarly, carbonation of real flue-gases will occur in the presence of steam. However, to date, most research has been done without either of these two gaseous components present. Here, batch combustion experiments were performed in a pilot-scale fluidized-bed reactor to study the effects of steam and SO2 addition on CO2 capture by limestone-based sorbents calcined under oxygen-enriched air and oxy-fuel conditions. The initial fast kinetically controlled CO2 capture stage was dramatically reduced when the sorbent was calcined at realistic temperatures in the presence of SO2. This is attributed to both greater sintering due to higher local 2calcination temperatures required by high CO2 concentrations and CaSO4 formation. By contrast, steam in the synthetic flue gas during carbonation extended the initial, high-efficiency CO2 capture period compared with that observed during carbonation with dry synthetic flue gases. A comparison between pilot-scale fluidized-bed combustion (FBC) and thermogravimetric analysis (TGA) results showed that sorbent reactivity was considerably lower during pilot-scale FBC testing, as anticipated given the higher calcination temperatures employed in the FBC reactor and the presence of the other feed gases. The enhanced CO2 capture efficiency in FBC reactors with steam present was also confirmed by TGA tests. These results are important because they demonstrate how sorbent deactivation effects seen in realistic FBC calcium-looping operation can be successfully reduced by the presence of steam in the carbonator. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948458
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7177-7184[article] Pilot - scale study of CO2 capture by CaO - based sorbents in the presence of steam and SO2 [texte imprimé] / Robert T. Symonds, Auteur ; Dennis Y. Lu, Auteur ; Vasilije Manovic, Auteur . - 2012 . - pp. 7177-7184.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7177-7184
Mots-clés : Water vapor Carbon dioxide Résumé : Calcium looping cycles require an oxy-fired calciner burning coal for sorbent regeneration. Thus, in addition to O2 and CO2, the flue gases will include both steam and SO2, and similarly, carbonation of real flue-gases will occur in the presence of steam. However, to date, most research has been done without either of these two gaseous components present. Here, batch combustion experiments were performed in a pilot-scale fluidized-bed reactor to study the effects of steam and SO2 addition on CO2 capture by limestone-based sorbents calcined under oxygen-enriched air and oxy-fuel conditions. The initial fast kinetically controlled CO2 capture stage was dramatically reduced when the sorbent was calcined at realistic temperatures in the presence of SO2. This is attributed to both greater sintering due to higher local 2calcination temperatures required by high CO2 concentrations and CaSO4 formation. By contrast, steam in the synthetic flue gas during carbonation extended the initial, high-efficiency CO2 capture period compared with that observed during carbonation with dry synthetic flue gases. A comparison between pilot-scale fluidized-bed combustion (FBC) and thermogravimetric analysis (TGA) results showed that sorbent reactivity was considerably lower during pilot-scale FBC testing, as anticipated given the higher calcination temperatures employed in the FBC reactor and the presence of the other feed gases. The enhanced CO2 capture efficiency in FBC reactors with steam present was also confirmed by TGA tests. These results are important because they demonstrate how sorbent deactivation effects seen in realistic FBC calcium-looping operation can be successfully reduced by the presence of steam in the carbonator. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948458 Exemplaires
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Titre : Hydrogenation of tetralin over Ir - containing mesoporous catalysts Type de document : texte imprimé Auteurs : Verónica A. Vallés, Auteur ; Gerardo S. Balangero Bottazzi, Auteur ; María L. Martínez, Auteur Année de publication : 2012 Article en page(s) : pp. 7185-7195 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Catalyst Hydrogenation Résumé : A new series of catalysts based on noble metals have been prepared with the main aim of obtaining thiotolerant catalysts to be used in second-stage processes of mild hydrotreating. We studied the catalytic properties of 1 wt % Ir-containing mesoporous materials in the hydrogenation of tetralin to decalin, in the presence of 100 ppm of dibenzotiophene at 250 °C and 15 atm pressure of hydrogen, using a Parr reactor. Ir/mesoporous materials were prepared by wetness impregnation, using iridium acetylacetonate as the source of Ir. The Ir/SBA-3 catalyst synthesized by us had a high activity in tetralin hydrogenation under mild conditions. The experimental data were quantitatively represented by a modified Langmuir―Hinshelwood-type rate equation. The preliminary results reveal that these materials are promising catalyts for HDS/HDN reactions. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948459
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7185-7195[article] Hydrogenation of tetralin over Ir - containing mesoporous catalysts [texte imprimé] / Verónica A. Vallés, Auteur ; Gerardo S. Balangero Bottazzi, Auteur ; María L. Martínez, Auteur . - 2012 . - pp. 7185-7195.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7185-7195
Mots-clés : Catalyst Hydrogenation Résumé : A new series of catalysts based on noble metals have been prepared with the main aim of obtaining thiotolerant catalysts to be used in second-stage processes of mild hydrotreating. We studied the catalytic properties of 1 wt % Ir-containing mesoporous materials in the hydrogenation of tetralin to decalin, in the presence of 100 ppm of dibenzotiophene at 250 °C and 15 atm pressure of hydrogen, using a Parr reactor. Ir/mesoporous materials were prepared by wetness impregnation, using iridium acetylacetonate as the source of Ir. The Ir/SBA-3 catalyst synthesized by us had a high activity in tetralin hydrogenation under mild conditions. The experimental data were quantitatively represented by a modified Langmuir―Hinshelwood-type rate equation. The preliminary results reveal that these materials are promising catalyts for HDS/HDN reactions. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948459 Exemplaires
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Titre : Comparison of photodegradation performance of 1,1,1 - trichloroethane in aqueous solution with the addition of H2O2 or S2O82 – oxidants Type de document : texte imprimé Auteurs : Xiaogang Gu, Auteur ; Shuguang Lu, Auteur ; Zhaofu Qiu, Auteur Année de publication : 2012 Article en page(s) : pp. 7196-7204 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Oxidant Hydrogen peroxide Aqueous solution Photochemical degradation Résumé : The chemical oxidation of 1,1,1-trichloroethane (TCA), a widely detected groundwater pollutant, by UV/H2O2 and UV/S2O82― processes was investigated. The effects of various factors were evaluated, including peroxide/TCA molar ratio, solution pH, C― and HCO3― anions, and humic acid (HA). The results showed that TCA oxidation fit to a pseudo-first-order kinetic model. The optimum H2O2/TCA molar ratio was 5:1, with TCA removal of 54.2% in 60 min. In the UV/S2O82― process, higher molar ratios (from 1/1 to 10/1) resulted in higher TCA oxidation rates, and TCA could be completely removed after 60 min with a S2O82―/TCA molar ratio of 3/1. In addition, acidic conditions were favorable for TCA removal in the UV/S2O82― process, while maximum TCA removal was observed at pH 6 in the UV/H2O2 process. Both Cl― and HCO3― anions adversely affected TCA oxidation performance, and higher concentration of HA resulted in a lag phase for TCA oxidation in both processes. Several reaction intermediates, including 1,1,1,2-tetrachloroethane, carbon tetrachloride, chloroform, tetrachloroethylene, 1,1-dichloroethylene, and tri- and dichloroacetic acids, were first identified during TCA oxidation by S2O82― chemistry, while only monochloroacetic acid was detected in the UV/H2O2 process. The results indicated that the UV/S2O82― process was much more effective than the UV/H2O2 process, but the latter was more environmentally friendly because fewer toxic intermediates were produced. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948460
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7196-7204[article] Comparison of photodegradation performance of 1,1,1 - trichloroethane in aqueous solution with the addition of H2O2 or S2O82 – oxidants [texte imprimé] / Xiaogang Gu, Auteur ; Shuguang Lu, Auteur ; Zhaofu Qiu, Auteur . - 2012 . - pp. 7196-7204.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7196-7204
Mots-clés : Oxidant Hydrogen peroxide Aqueous solution Photochemical degradation Résumé : The chemical oxidation of 1,1,1-trichloroethane (TCA), a widely detected groundwater pollutant, by UV/H2O2 and UV/S2O82― processes was investigated. The effects of various factors were evaluated, including peroxide/TCA molar ratio, solution pH, C― and HCO3― anions, and humic acid (HA). The results showed that TCA oxidation fit to a pseudo-first-order kinetic model. The optimum H2O2/TCA molar ratio was 5:1, with TCA removal of 54.2% in 60 min. In the UV/S2O82― process, higher molar ratios (from 1/1 to 10/1) resulted in higher TCA oxidation rates, and TCA could be completely removed after 60 min with a S2O82―/TCA molar ratio of 3/1. In addition, acidic conditions were favorable for TCA removal in the UV/S2O82― process, while maximum TCA removal was observed at pH 6 in the UV/H2O2 process. Both Cl― and HCO3― anions adversely affected TCA oxidation performance, and higher concentration of HA resulted in a lag phase for TCA oxidation in both processes. Several reaction intermediates, including 1,1,1,2-tetrachloroethane, carbon tetrachloride, chloroform, tetrachloroethylene, 1,1-dichloroethylene, and tri- and dichloroacetic acids, were first identified during TCA oxidation by S2O82― chemistry, while only monochloroacetic acid was detected in the UV/H2O2 process. The results indicated that the UV/S2O82― process was much more effective than the UV/H2O2 process, but the latter was more environmentally friendly because fewer toxic intermediates were produced. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948460 Exemplaires
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Titre : Reactive thermal hazards of tributyl phosphate with nitric acid Type de document : texte imprimé Auteurs : Velayuthan Sreekantan Smitha, Auteur ; Mahadevan Surianarayanan, Auteur ; Hariharan Seshadri, Auteur Année de publication : 2012 Article en page(s) : pp. 7205-7210 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hazard Résumé : The accelerating rate calorimetry studies on the tributyl phosphate and nitric acid reactions at various acid concentrations revealed that the conditions for red oil formation may vary with acid strength. The accelerating rate calorimeter studies supplemented with FT-IR characterization of the end products confirmed the formation of red oil at temperatures as low as 75 °C. This study thus strongly advocates for a revisit of safety limits set in the fuel reprocessing plants to prevent red oil formation. The chemical pathway for red oil formation is worked out. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948461
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7205-7210[article] Reactive thermal hazards of tributyl phosphate with nitric acid [texte imprimé] / Velayuthan Sreekantan Smitha, Auteur ; Mahadevan Surianarayanan, Auteur ; Hariharan Seshadri, Auteur . - 2012 . - pp. 7205-7210.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7205-7210
Mots-clés : Hazard Résumé : The accelerating rate calorimetry studies on the tributyl phosphate and nitric acid reactions at various acid concentrations revealed that the conditions for red oil formation may vary with acid strength. The accelerating rate calorimeter studies supplemented with FT-IR characterization of the end products confirmed the formation of red oil at temperatures as low as 75 °C. This study thus strongly advocates for a revisit of safety limits set in the fuel reprocessing plants to prevent red oil formation. The chemical pathway for red oil formation is worked out. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948461 Exemplaires
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Titre : Supported nanometric Pd hierarchical catalysts for efficient toluene removal : Catalyst characterization and activity elucidation Type de document : texte imprimé Auteurs : Chi He, Auteur ; Lingling Xu, Auteur ; Lin Yue, Auteur Année de publication : 2012 Article en page(s) : pp. 7211–7222 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Nanometric Catalysts Résumé : Micro-/mesoporous composite materials with coke-resistant ZSM-5 and three-dimensional large-pore KIT-6 as their micro- and mesoporous components, respectively, were synthesized using a simple in situ overgrowth approach. The hydrothermal stabilities and acidities of the biporous catalysts were found to be significantly enhanced. All composite materials acted as powerful catalysts for toluene oxidation. Among them, Pd/ZK-6% showed the highest catalytic activity, with 90% toluene decomposition at 203 °C, which is more than 30 °C lower than required for Pd/KIT-6. It can be anticipated that the specific surface area and acidity have a synergistic effect on the Pd dispersion. Overall, the catalytic activities were found to be primarily correlated with the specific surface area, support acidity, Pd dispersion, and toluene adsorption capability. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201243c
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7211–7222[article] Supported nanometric Pd hierarchical catalysts for efficient toluene removal : Catalyst characterization and activity elucidation [texte imprimé] / Chi He, Auteur ; Lingling Xu, Auteur ; Lin Yue, Auteur . - 2012 . - pp. 7211–7222.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7211–7222
Mots-clés : Nanometric Catalysts Résumé : Micro-/mesoporous composite materials with coke-resistant ZSM-5 and three-dimensional large-pore KIT-6 as their micro- and mesoporous components, respectively, were synthesized using a simple in situ overgrowth approach. The hydrothermal stabilities and acidities of the biporous catalysts were found to be significantly enhanced. All composite materials acted as powerful catalysts for toluene oxidation. Among them, Pd/ZK-6% showed the highest catalytic activity, with 90% toluene decomposition at 203 °C, which is more than 30 °C lower than required for Pd/KIT-6. It can be anticipated that the specific surface area and acidity have a synergistic effect on the Pd dispersion. Overall, the catalytic activities were found to be primarily correlated with the specific surface area, support acidity, Pd dispersion, and toluene adsorption capability. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201243c Exemplaires
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Titre : Applicability of new acrylic, weakly basic anion exchanger purolite A - 830 of very high capacity in removal of palladium(II) chloro - complexes Type de document : texte imprimé Auteurs : Anna Wolowicz, Auteur ; Zbigniew Hubicki, Auteur Année de publication : 2012 Article en page(s) : pp. 7223–7230 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Anion exchanger Résumé : According to the manufacture description Purolite A-830 is a sorbent of very high capacity (2.75 eq/dm3), which was the main reason for examining its applicability in the removal of palladium(II) chloro-complexes from acidic solutions and comparison of its experimental capacity with other weakly basic anion exchangers. The influence of several parameters such as hydrochloric and nitric acids concentrations, competitive anions (effect of AlCl3 addition) and temperature increase were studied. Sorption isotherms were obtained and modeled using the Langmuir and the Freundlich model. The influences of agitation speed, palladium concentration, and particle size on sorption kinetics were considered. Kinetic curves were modeled using the pseudo-first- and pseudo-second-order kinetic equations. According to the evaluation using the Langmuir equation, the maximum sorption capacity obtained from the Langmuir isotherm was equal to 356.88 mg Pd(II)/g. The reduction of Pd(II) uptake was observed with the increasing concentration of chloride ions, temperature, and AlCl3 addition. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948463
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7223–7230[article] Applicability of new acrylic, weakly basic anion exchanger purolite A - 830 of very high capacity in removal of palladium(II) chloro - complexes [texte imprimé] / Anna Wolowicz, Auteur ; Zbigniew Hubicki, Auteur . - 2012 . - pp. 7223–7230.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7223–7230
Mots-clés : Anion exchanger Résumé : According to the manufacture description Purolite A-830 is a sorbent of very high capacity (2.75 eq/dm3), which was the main reason for examining its applicability in the removal of palladium(II) chloro-complexes from acidic solutions and comparison of its experimental capacity with other weakly basic anion exchangers. The influence of several parameters such as hydrochloric and nitric acids concentrations, competitive anions (effect of AlCl3 addition) and temperature increase were studied. Sorption isotherms were obtained and modeled using the Langmuir and the Freundlich model. The influences of agitation speed, palladium concentration, and particle size on sorption kinetics were considered. Kinetic curves were modeled using the pseudo-first- and pseudo-second-order kinetic equations. According to the evaluation using the Langmuir equation, the maximum sorption capacity obtained from the Langmuir isotherm was equal to 356.88 mg Pd(II)/g. The reduction of Pd(II) uptake was observed with the increasing concentration of chloride ions, temperature, and AlCl3 addition. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948463 Exemplaires
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Titre : Performance of thin - layer hydrogel polyethersulfone composite membranes during dead - end ultrafiltration of various protein solutions Type de document : texte imprimé Auteurs : Polina D. Peeva, Auteur ; Thomas Knoche, Auteur ; Thorsten Pieper, Auteur Année de publication : 2012 Article en page(s) : pp. 7231-7241 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Membrane separation Ultrafiltration Composite material Résumé : Low-fouling thin-layer hydrogel composite membranes were prepared during UV initiated grafting from of the hydrophilic monomer poly(ethylene glycol) methacrylate onto polyethersulfone (PES) ultrafiltration (UF) membranes. The selectivity of the functionalized membranes was adjusted by varying the UV irradiation dose and applying the cross-linking agent N,N'-methylene bisacrylamide. Virgin and composite membranes were tested in short (20-fold volume reduction) and long (24 h) dead-end (DE) filtration experiments of various protein solutions and the performance improvement by the membrane hydrophilization was evaluated. Moreover, the effects of membrane molecular weight cutoff, solute size, and solute charge (as function of pH) as well as cleaning were evaluated. The dominating fouling mechanisms were identified using the classical model equation proposed by Hermia [Hermia, J. Constant Pressure Blocking Filtration Laws—Application to Power Law Non-Newtonian Fluids. Trans. Inst. Chem. Eng. 1982, 60, 183] for DE filtration mode. The results showed that the surface functionalization improved the membrane performance during filtration of protein solutions. Moreover, the cleanability of functionalized membranes with water was much more effective compared to unmodified PES membranes. The performed fouling mechanism study clarified the occurring processes during filtrations with virgin and composite membranes. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948464
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7231-7241[article] Performance of thin - layer hydrogel polyethersulfone composite membranes during dead - end ultrafiltration of various protein solutions [texte imprimé] / Polina D. Peeva, Auteur ; Thomas Knoche, Auteur ; Thorsten Pieper, Auteur . - 2012 . - pp. 7231-7241.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7231-7241
Mots-clés : Membrane separation Ultrafiltration Composite material Résumé : Low-fouling thin-layer hydrogel composite membranes were prepared during UV initiated grafting from of the hydrophilic monomer poly(ethylene glycol) methacrylate onto polyethersulfone (PES) ultrafiltration (UF) membranes. The selectivity of the functionalized membranes was adjusted by varying the UV irradiation dose and applying the cross-linking agent N,N'-methylene bisacrylamide. Virgin and composite membranes were tested in short (20-fold volume reduction) and long (24 h) dead-end (DE) filtration experiments of various protein solutions and the performance improvement by the membrane hydrophilization was evaluated. Moreover, the effects of membrane molecular weight cutoff, solute size, and solute charge (as function of pH) as well as cleaning were evaluated. The dominating fouling mechanisms were identified using the classical model equation proposed by Hermia [Hermia, J. Constant Pressure Blocking Filtration Laws—Application to Power Law Non-Newtonian Fluids. Trans. Inst. Chem. Eng. 1982, 60, 183] for DE filtration mode. The results showed that the surface functionalization improved the membrane performance during filtration of protein solutions. Moreover, the cleanability of functionalized membranes with water was much more effective compared to unmodified PES membranes. The performed fouling mechanism study clarified the occurring processes during filtrations with virgin and composite membranes. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948464 Exemplaires
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Titre : Thermal and transport properties of six ionic liquids : An experimental and molecular dynamics study Type de document : texte imprimé Auteurs : Hongjun Liu, Auteur ; Edward Maginn, Auteur ; Ann E. Visser, Auteur Année de publication : 2012 Article en page(s) : pp. 7242–7254 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Ionic liquids Dynamics Résumé : Experimental measurements and molecular dynamics simulations are used to determine the density, heat capacity, self-diffusivity, shear viscosity, and thermal conductivity of six ionic liquids over a range of temperatures. The ionic liquids examined are 1-butyl-3-methylimidazolium bis[(perfluoroethyl)sulfonyl]imide ([bmim][Pf2N]), 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([bmim][Tf2N]), 1-butyl-2,3-dimethylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([bmmim][Tf2N]), 1-butyl-1-methylpyrrolidinium bis[(trifluoromethyl)sulfonyl]imide ([bmpyr][Tf2N]), N-butyl-N,N,N-trimethylammonium bis[(trifluoromethyl)sulfonyl]imide ([N4111][Tf2N]), and N,N,N-trimethylammonium-N-butanoic acid bis[(trifluoromethyl)sulfonyl]imide ([N4111][COOHTfN]). The results of this work suggest that several of these ionic liquids have properties that would enable them to be successful high temperature heat transfer fluids. In particular, their energy storage densities and thermal conductivities are quite favorable when compared to conventional heat transfer fluids. The low temperature viscosities of the ILs are significantly higher than conventional fluids, but the viscosities drop rapidly with increasing temperature. The simulations, which are purely predictive, agree quantitatively with the experimental data for density and qualitatively for other properties. It is shown that the simulated thermal conductivity can be adequately correlated with density and molecular weight of the [Tf2N]-based ionic liquids. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300222a
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7242–7254[article] Thermal and transport properties of six ionic liquids : An experimental and molecular dynamics study [texte imprimé] / Hongjun Liu, Auteur ; Edward Maginn, Auteur ; Ann E. Visser, Auteur . - 2012 . - pp. 7242–7254.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7242–7254
Mots-clés : Ionic liquids Dynamics Résumé : Experimental measurements and molecular dynamics simulations are used to determine the density, heat capacity, self-diffusivity, shear viscosity, and thermal conductivity of six ionic liquids over a range of temperatures. The ionic liquids examined are 1-butyl-3-methylimidazolium bis[(perfluoroethyl)sulfonyl]imide ([bmim][Pf2N]), 1-butyl-3-methylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([bmim][Tf2N]), 1-butyl-2,3-dimethylimidazolium bis[(trifluoromethyl)sulfonyl]imide ([bmmim][Tf2N]), 1-butyl-1-methylpyrrolidinium bis[(trifluoromethyl)sulfonyl]imide ([bmpyr][Tf2N]), N-butyl-N,N,N-trimethylammonium bis[(trifluoromethyl)sulfonyl]imide ([N4111][Tf2N]), and N,N,N-trimethylammonium-N-butanoic acid bis[(trifluoromethyl)sulfonyl]imide ([N4111][COOHTfN]). The results of this work suggest that several of these ionic liquids have properties that would enable them to be successful high temperature heat transfer fluids. In particular, their energy storage densities and thermal conductivities are quite favorable when compared to conventional heat transfer fluids. The low temperature viscosities of the ILs are significantly higher than conventional fluids, but the viscosities drop rapidly with increasing temperature. The simulations, which are purely predictive, agree quantitatively with the experimental data for density and qualitatively for other properties. It is shown that the simulated thermal conductivity can be adequately correlated with density and molecular weight of the [Tf2N]-based ionic liquids. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300222a Exemplaires
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Titre : Permeability, viscoelasticity, and flammability performances and their relationship to polymer nanocomposites Type de document : texte imprimé Auteurs : Ping’an Song, Auteur ; Youming Yu, Auteur ; Tao Zhang, Auteur Année de publication : 2012 Article en page(s) : pp. 7255-7263 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Nanocomposite Flammability Viscoelasticity Permeability Résumé : Despite abundant studies on gas barrier, viscoelastic, and flammability properties of polymer nanocomposites, comprehensive understandings of these performances and their relationships are still lacking. We herein attempt to gain deep insights into the performances by creating several polymer nanocomposites by incorporating three types of nanoparticles, nanoclay (Clay), carbon nanotubes (CNTs), and reduced graphene nanoplates (RGO), into polypropylene (PP). The oxygen permeability, viscoelasticity, and flammability measurements demonstrate that RGO can lead to much more reduction in the gas permeability (by ∼73%) and flammability (peak heat release rate (PHRR) reduction by ∼78%), as well as a higher storage modulus and melt viscosity of polymer matrix relative to clay and CNTs at the same loading (1.0 wt %) due to its higher aspect ratio. Clay performs better than CNTs in terms of gas barrier property due to its lamellar structure while behaves worse than CNTs in terms of increasing the melt viscosity and reducing flammability of polymers. Most important, there is a nearly line correlation among these properties for all polymer nanocomposites despite some deviations. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948466
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7255-7263[article] Permeability, viscoelasticity, and flammability performances and their relationship to polymer nanocomposites [texte imprimé] / Ping’an Song, Auteur ; Youming Yu, Auteur ; Tao Zhang, Auteur . - 2012 . - pp. 7255-7263.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7255-7263
Mots-clés : Nanocomposite Flammability Viscoelasticity Permeability Résumé : Despite abundant studies on gas barrier, viscoelastic, and flammability properties of polymer nanocomposites, comprehensive understandings of these performances and their relationships are still lacking. We herein attempt to gain deep insights into the performances by creating several polymer nanocomposites by incorporating three types of nanoparticles, nanoclay (Clay), carbon nanotubes (CNTs), and reduced graphene nanoplates (RGO), into polypropylene (PP). The oxygen permeability, viscoelasticity, and flammability measurements demonstrate that RGO can lead to much more reduction in the gas permeability (by ∼73%) and flammability (peak heat release rate (PHRR) reduction by ∼78%), as well as a higher storage modulus and melt viscosity of polymer matrix relative to clay and CNTs at the same loading (1.0 wt %) due to its higher aspect ratio. Clay performs better than CNTs in terms of gas barrier property due to its lamellar structure while behaves worse than CNTs in terms of increasing the melt viscosity and reducing flammability of polymers. Most important, there is a nearly line correlation among these properties for all polymer nanocomposites despite some deviations. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948466 Exemplaires
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Titre : Novel biodegradable and double crystalline multiblock copolymers comprising of poly (butylene succinate) and poly (E - caprolactone) : Synthesis, characterization, and properties Type de document : texte imprimé Auteurs : Liuchun Zheng, Auteur ; Chuncheng Li, Auteur ; Zhaodong Wang, Auteur Année de publication : 2012 Article en page(s) : pp. 7264-7272 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Biodegradable Crystalline Copolymers Résumé : A series of double crystalline multiblock copolymers composed of poly(butylene succinate) (PBS) and poly(ε-caprolactone) (PCL) have been successfully synthesized with hexamethylene diisocyanate (HDI) as a chain extender. The copolymers were systematically characterized by 1H NMR, GPC, TGA, DSC, WAXD, and mechanical testing. The results indicate that the PBS segment is immiscible with the PCL segment in the amorphous region. The copolymers follow a two-stage degradation behavior, and thermal stability increases with increasing PBS content. PBS and PCL in the copolymers crystallize and melt separately. The mechanical properties of the copolymers can be conveniently adjusted from rigid plastics to flexible elastomers by changing the feed composition. The impact strength is substantially improved by the incorporation of the PCL segment. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300576z
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7264-7272[article] Novel biodegradable and double crystalline multiblock copolymers comprising of poly (butylene succinate) and poly (E - caprolactone) : Synthesis, characterization, and properties [texte imprimé] / Liuchun Zheng, Auteur ; Chuncheng Li, Auteur ; Zhaodong Wang, Auteur . - 2012 . - pp. 7264-7272.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7264-7272
Mots-clés : Biodegradable Crystalline Copolymers Résumé : A series of double crystalline multiblock copolymers composed of poly(butylene succinate) (PBS) and poly(ε-caprolactone) (PCL) have been successfully synthesized with hexamethylene diisocyanate (HDI) as a chain extender. The copolymers were systematically characterized by 1H NMR, GPC, TGA, DSC, WAXD, and mechanical testing. The results indicate that the PBS segment is immiscible with the PCL segment in the amorphous region. The copolymers follow a two-stage degradation behavior, and thermal stability increases with increasing PBS content. PBS and PCL in the copolymers crystallize and melt separately. The mechanical properties of the copolymers can be conveniently adjusted from rigid plastics to flexible elastomers by changing the feed composition. The impact strength is substantially improved by the incorporation of the PCL segment. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300576z Exemplaires
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Titre : Fabrication of high toughness poly (lactic acid) by combining plasticization with cross - linking reaction Type de document : texte imprimé Auteurs : Zhongjie Ren, Auteur ; Huihui Li, Auteur ; Xiaoli Sun, Auteur Année de publication : 2012 Article en page(s) : pp. 7273-7278 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Plasticization Résumé : A new method to produce high toughness Poly(lactic acid) (PLA) was introduced in this study. The blends of low molecular weight triacetin (TAC) and oligomeric poly(1,3-butylene glycol adipate) (PBGA) were first used as multiple plasticizers to lubricate PLA and then the plasticized PLA cross-linked with triallyl isocyanurate (TAIC) through electron beam irradiation. In this way, a kind of stable PLA material with high elongation at break was obtained. The elongation at break of the prepared material is more than 260% with a tensile strength of 23.5 MPa when the irradiation dose is 10 Mrad. Detailed studies of Fourier transform infrared (FTIR) spectra and viscosity experiments revealed that both the self-cross-linking of the PLA molecular chains and the cross-linking between the molecular chains of PLA and PBGA could occur. This results in the remarkable improvement in the performance of the obtained materials. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948468
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7273-7278[article] Fabrication of high toughness poly (lactic acid) by combining plasticization with cross - linking reaction [texte imprimé] / Zhongjie Ren, Auteur ; Huihui Li, Auteur ; Xiaoli Sun, Auteur . - 2012 . - pp. 7273-7278.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7273-7278
Mots-clés : Plasticization Résumé : A new method to produce high toughness Poly(lactic acid) (PLA) was introduced in this study. The blends of low molecular weight triacetin (TAC) and oligomeric poly(1,3-butylene glycol adipate) (PBGA) were first used as multiple plasticizers to lubricate PLA and then the plasticized PLA cross-linked with triallyl isocyanurate (TAIC) through electron beam irradiation. In this way, a kind of stable PLA material with high elongation at break was obtained. The elongation at break of the prepared material is more than 260% with a tensile strength of 23.5 MPa when the irradiation dose is 10 Mrad. Detailed studies of Fourier transform infrared (FTIR) spectra and viscosity experiments revealed that both the self-cross-linking of the PLA molecular chains and the cross-linking between the molecular chains of PLA and PBGA could occur. This results in the remarkable improvement in the performance of the obtained materials. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948468 Exemplaires
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Titre : Assessment of changes due to accelerated weathering of low - density polyethylene / feather composites Type de document : texte imprimé Auteurs : Spiridon Siouris, Auteur ; Oana Maria Paduraru, Auteur ; Marek Rudowski, Auteur Année de publication : 2012 Article en page(s) : pp. 7279-7286 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Composite material Density Material weathering Weathering Résumé : In this study, property changes of controlled aged LDPE/feather composites in comparison to those of nonaged samples were investigated by mechanical tests, dynamic rheological and thermal tests, infrared spectroscopy, and oxygen permeability analysis. The viscoelastic behavior of the aged composites was modified, whereas a pseudoplastic character was observed for the nonaged samples. After weathering, infrared spectroscopy indicated the formation of carbonyl and vinyl groups, and the oxygen permeability became significantly higher than for the reference samples. DSC results showed α-helix denaturation of keratin after aging and an increase in crystallinity due to reinforcement of composites containing feather fibers upon UV exposure. An aging time of 500 h was found to induce surface degradation of composites, especially for a feather fiber loading of 10 wt %. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948469
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7279-7286[article] Assessment of changes due to accelerated weathering of low - density polyethylene / feather composites [texte imprimé] / Spiridon Siouris, Auteur ; Oana Maria Paduraru, Auteur ; Marek Rudowski, Auteur . - 2012 . - pp. 7279-7286.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7279-7286
Mots-clés : Composite material Density Material weathering Weathering Résumé : In this study, property changes of controlled aged LDPE/feather composites in comparison to those of nonaged samples were investigated by mechanical tests, dynamic rheological and thermal tests, infrared spectroscopy, and oxygen permeability analysis. The viscoelastic behavior of the aged composites was modified, whereas a pseudoplastic character was observed for the nonaged samples. After weathering, infrared spectroscopy indicated the formation of carbonyl and vinyl groups, and the oxygen permeability became significantly higher than for the reference samples. DSC results showed α-helix denaturation of keratin after aging and an increase in crystallinity due to reinforcement of composites containing feather fibers upon UV exposure. An aging time of 500 h was found to induce surface degradation of composites, especially for a feather fiber loading of 10 wt %. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948469 Exemplaires
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Titre : Nonconvex generalized benders decomposition with piecewise convex relaxations for global optimization of integrated process design and operation problems Type de document : texte imprimé Auteurs : Xiang Li, Auteur ; Yang Chen, Auteur ; Paul I. Barton, Auteur Année de publication : 2012 Article en page(s) : pp. 7287–7299 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Optimization Nonconvex Résumé : This paper considers the global optimization of challenging stochastic or multiperiod mixed-integer nonconvex programs that arise from integrated process design and operation. The difficulties of the problems are large scale and the nonconvexity involved. Recently, a novel decomposition method, called nonconvex generalized Benders decomposition (NGBD), has been developed to solve this problem to global optimality finitely, and this method shows dramatic computational advantages over traditional branch-and-bound based global optimization methods because it can exploit well the decomposable structure of such problems. Since the convergence rate of NGBD is largely dependent on the tightness of the convex relaxations of the nonconvex functions, the efficiency of NGBD can be improved by generating tighter convex relaxations. Building on the success of piecewise linearization for bilinear programs in the process systems engineering literature, this paper develops a piecewise convex relaxation framework, which can yield tighter convex relaxations for factorable nonconvex programs, and integrates this framework into NGBD to expedite the solution. Case studies of a classical literature problem and an industry-level problem show that, while NGBD can solve problems that are intractable for a state-of-the-art global optimization solver, integrating the proposed piecewise convex relaxation into NGBD helps to reduce the solution time by up to an order of magnitude. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201262f
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7287–7299[article] Nonconvex generalized benders decomposition with piecewise convex relaxations for global optimization of integrated process design and operation problems [texte imprimé] / Xiang Li, Auteur ; Yang Chen, Auteur ; Paul I. Barton, Auteur . - 2012 . - pp. 7287–7299.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7287–7299
Mots-clés : Optimization Nonconvex Résumé : This paper considers the global optimization of challenging stochastic or multiperiod mixed-integer nonconvex programs that arise from integrated process design and operation. The difficulties of the problems are large scale and the nonconvexity involved. Recently, a novel decomposition method, called nonconvex generalized Benders decomposition (NGBD), has been developed to solve this problem to global optimality finitely, and this method shows dramatic computational advantages over traditional branch-and-bound based global optimization methods because it can exploit well the decomposable structure of such problems. Since the convergence rate of NGBD is largely dependent on the tightness of the convex relaxations of the nonconvex functions, the efficiency of NGBD can be improved by generating tighter convex relaxations. Building on the success of piecewise linearization for bilinear programs in the process systems engineering literature, this paper develops a piecewise convex relaxation framework, which can yield tighter convex relaxations for factorable nonconvex programs, and integrates this framework into NGBD to expedite the solution. Case studies of a classical literature problem and an industry-level problem show that, while NGBD can solve problems that are intractable for a state-of-the-art global optimization solver, integrating the proposed piecewise convex relaxation into NGBD helps to reduce the solution time by up to an order of magnitude. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201262f Exemplaires
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Titre : Production scheduling of a large - scale steelmaking continuous casting process via unit - specific event - based continuous - time models : Short - term and medium - term shceduling Type de document : texte imprimé Auteurs : Jie Li, Auteur ; Xin Xiao, Auteur ; Qiuhua Tang, Auteur Année de publication : 2012 Article en page(s) : pp. 7300-7319 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Medium term Short Modeling Continuous time Casting Scheduling Production Résumé : The scheduling of steelmaking continuous-casting (SCC) processes is of major importance in iron and steel operations, since it is often a bottleneck in iron and steel production. Optimal scheduling of SCC processes can increase profit, minimize production cost, reduce material and energy consumption, and improve customer satisfaction. Scheduling of SCC processes is challenging, because of its combinatorial nature, complex practical constraints, and strict requirements on material continuity and flow time, as well as the technological requirements to ensure practical feasibility of the resulting scheduling. In this paper, we first develop a novel unit-specific event-based continuous-time mixed-integer linear optimization (MILP) model for this problem and incorporate several realistic operational features. Then, we extend the rolling horizon approach proposed by Lin et aL [Lin et al. Ind. Eng. Chem. Res. 2002, 41, 3884―3906] and Janak et al. [Janak et al. Ind. Eng. Chem. Res. 2006, 45, 8234―8252] to solve this large-scale and complex optimization problem. Four large-scale industrial problems are used to illustrate the efficiency and effectiveness of the proposed formulation and rolling horizon approach. The computational results show that the extended rolling horizon approach successfully solves the large-scale case studies and results in the same or better integer solution than that obtained from directly solving the entire scheduling model. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948471
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7300-7319[article] Production scheduling of a large - scale steelmaking continuous casting process via unit - specific event - based continuous - time models : Short - term and medium - term shceduling [texte imprimé] / Jie Li, Auteur ; Xin Xiao, Auteur ; Qiuhua Tang, Auteur . - 2012 . - pp. 7300-7319.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7300-7319
Mots-clés : Medium term Short Modeling Continuous time Casting Scheduling Production Résumé : The scheduling of steelmaking continuous-casting (SCC) processes is of major importance in iron and steel operations, since it is often a bottleneck in iron and steel production. Optimal scheduling of SCC processes can increase profit, minimize production cost, reduce material and energy consumption, and improve customer satisfaction. Scheduling of SCC processes is challenging, because of its combinatorial nature, complex practical constraints, and strict requirements on material continuity and flow time, as well as the technological requirements to ensure practical feasibility of the resulting scheduling. In this paper, we first develop a novel unit-specific event-based continuous-time mixed-integer linear optimization (MILP) model for this problem and incorporate several realistic operational features. Then, we extend the rolling horizon approach proposed by Lin et aL [Lin et al. Ind. Eng. Chem. Res. 2002, 41, 3884―3906] and Janak et al. [Janak et al. Ind. Eng. Chem. Res. 2006, 45, 8234―8252] to solve this large-scale and complex optimization problem. Four large-scale industrial problems are used to illustrate the efficiency and effectiveness of the proposed formulation and rolling horizon approach. The computational results show that the extended rolling horizon approach successfully solves the large-scale case studies and results in the same or better integer solution than that obtained from directly solving the entire scheduling model. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948471 Exemplaires
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Titre : Product design : A nanomized nutraceutical with enhanced bioactivity and bioavailability Type de document : texte imprimé Auteurs : Yeuk Tin Lau, Auteur ; Na Chen, Auteur ; Kam Ming Ko, Auteur Année de publication : 2012 Article en page(s) : pp. 7320-7326 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Bioavailability Product development Résumé : This study considered the design and process development of nanomized products in two product forms: nanoemulsion and nanodispersible solids. The effect of product formulation and processing conditions on product attributes such as particle size and appearance were studied using orange oil and Oil Red O as model compounds. The relationship between particle size and product quality in terms of bioactivity and bioavaflabflity was illustrated using schisandrin B, a strong antioxidant, as a model drug. The bioactivity as measured by in vivo glutathione regeneration capacity assay of schisandrin B with an average size of 45 nm was nearly double that of the original coarse schisandrin B; the corresponding bioavailability as measured by the plasma schisandrin B level in an animal study was 14.5-fold higher. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948472
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7320-7326[article] Product design : A nanomized nutraceutical with enhanced bioactivity and bioavailability [texte imprimé] / Yeuk Tin Lau, Auteur ; Na Chen, Auteur ; Kam Ming Ko, Auteur . - 2012 . - pp. 7320-7326.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7320-7326
Mots-clés : Bioavailability Product development Résumé : This study considered the design and process development of nanomized products in two product forms: nanoemulsion and nanodispersible solids. The effect of product formulation and processing conditions on product attributes such as particle size and appearance were studied using orange oil and Oil Red O as model compounds. The relationship between particle size and product quality in terms of bioactivity and bioavaflabflity was illustrated using schisandrin B, a strong antioxidant, as a model drug. The bioactivity as measured by in vivo glutathione regeneration capacity assay of schisandrin B with an average size of 45 nm was nearly double that of the original coarse schisandrin B; the corresponding bioavailability as measured by the plasma schisandrin B level in an animal study was 14.5-fold higher. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948472 Exemplaires
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Titre : Transfer of process monitoring models between different plants using latent variable techniques Type de document : texte imprimé Auteurs : Pierantonio Facco, Auteur ; Emanuele Tomba, Auteur ; Fabrizio Bezzo, Auteur Année de publication : 2012 Article en page(s) : pp. 7327–7339 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Process monitoring models Résumé : This paper addresses the scenario where the manufacturing of a product with assigned quality specifications is transferred from a plant A to a plant B, which uses the same manufacturing process as plant A, but may differ for scale, configuration, actual operating conditions, measurement system arrangement, or simply location. The issue arises on whether the process data already available for plant A can be exploited to build a process monitoring model enabling to monitor the operation of plant B until enough data have been collected in this plant to design a monitoring model based entirely on the incoming data. This paper presents a general framework to tackle this problem (which we refer to as a model transfer problem), and three possible latent variable approaches within this framework are proposed and evaluated. One approach makes use of measurements coming from plant A only, whereas the other two integrate plant A data and plant B data into a single adaptive monitoring model. The proposed approaches are tested on an industrial spray-drying process, where plant A is a pilot unit and plant B is a production unit. It is shown that all proposed model transfer approaches guarantee very satisfactory monitoring performance in plant B, with quick fault detection, limited number of false alarms or undetected faults, and limited (or no) need of plant B data to accomplish the model transfer. We believe that these strategies can provide a valuable contribution to the practical implementation of quality-by-design methodologies and continuous quality assurance programs in product manufacturing. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202974u
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7327–7339[article] Transfer of process monitoring models between different plants using latent variable techniques [texte imprimé] / Pierantonio Facco, Auteur ; Emanuele Tomba, Auteur ; Fabrizio Bezzo, Auteur . - 2012 . - pp. 7327–7339.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7327–7339
Mots-clés : Process monitoring models Résumé : This paper addresses the scenario where the manufacturing of a product with assigned quality specifications is transferred from a plant A to a plant B, which uses the same manufacturing process as plant A, but may differ for scale, configuration, actual operating conditions, measurement system arrangement, or simply location. The issue arises on whether the process data already available for plant A can be exploited to build a process monitoring model enabling to monitor the operation of plant B until enough data have been collected in this plant to design a monitoring model based entirely on the incoming data. This paper presents a general framework to tackle this problem (which we refer to as a model transfer problem), and three possible latent variable approaches within this framework are proposed and evaluated. One approach makes use of measurements coming from plant A only, whereas the other two integrate plant A data and plant B data into a single adaptive monitoring model. The proposed approaches are tested on an industrial spray-drying process, where plant A is a pilot unit and plant B is a production unit. It is shown that all proposed model transfer approaches guarantee very satisfactory monitoring performance in plant B, with quick fault detection, limited number of false alarms or undetected faults, and limited (or no) need of plant B data to accomplish the model transfer. We believe that these strategies can provide a valuable contribution to the practical implementation of quality-by-design methodologies and continuous quality assurance programs in product manufacturing. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202974u Exemplaires
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Titre : Application of the minka and myers theory of liquid adsorption to systems with two liquid phases Type de document : texte imprimé Auteurs : Christine Wegmann, Auteur ; Piet J. A. M. Kerkhof, Auteur Année de publication : 2012 Article en page(s) : pp. 7340–7348 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Adsorption Liquid phases Résumé : Dissolved acrylonitrile can be separated from a water stream by adsorption onto a polymeric sorbent (Dowex Optipore L-493) in a fixed bed and desorbed again by flushing the column with acetone. When the acetone fraction in the ternary mixture acrylonitrile/acetone/water is low and the acrylonitrile fraction is high, a phase separation between a water rich and an acrylonitrile rich phase occurs. In order to find the operating parameters for this separation process, the adsorbed amounts for all possible compositions of the bulk mixture need to be known. By use of a thermodynamic model, the loading in the ternary system was predicted from the three binary isotherms acrylonitrile/water, acrylonitrile/acetone, and acetone/water. These isotherms were determined experimentally. From the binary isotherms, the activity coefficients in the adsorbed phase were estimated. The binary model for the adsorbed phase activity coefficients was then extended to a ternary model. From this ternary activity coefficient model, the composition of the adsorbed phase was calculated as a function of the liquid phase composition. The agreement between the calculated adsorbed phase composition and the experimentally determined adsorbed phase composition is good to fair. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300273x
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7340–7348[article] Application of the minka and myers theory of liquid adsorption to systems with two liquid phases [texte imprimé] / Christine Wegmann, Auteur ; Piet J. A. M. Kerkhof, Auteur . - 2012 . - pp. 7340–7348.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7340–7348
Mots-clés : Adsorption Liquid phases Résumé : Dissolved acrylonitrile can be separated from a water stream by adsorption onto a polymeric sorbent (Dowex Optipore L-493) in a fixed bed and desorbed again by flushing the column with acetone. When the acetone fraction in the ternary mixture acrylonitrile/acetone/water is low and the acrylonitrile fraction is high, a phase separation between a water rich and an acrylonitrile rich phase occurs. In order to find the operating parameters for this separation process, the adsorbed amounts for all possible compositions of the bulk mixture need to be known. By use of a thermodynamic model, the loading in the ternary system was predicted from the three binary isotherms acrylonitrile/water, acrylonitrile/acetone, and acetone/water. These isotherms were determined experimentally. From the binary isotherms, the activity coefficients in the adsorbed phase were estimated. The binary model for the adsorbed phase activity coefficients was then extended to a ternary model. From this ternary activity coefficient model, the composition of the adsorbed phase was calculated as a function of the liquid phase composition. The agreement between the calculated adsorbed phase composition and the experimentally determined adsorbed phase composition is good to fair. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300273x Exemplaires
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Titre : Enrichment and purification of total flavonoid C - glycosides from abrus mollis extracts with macroporous resins Type de document : texte imprimé Auteurs : Huibin Du, Auteur ; Hao Wang, Auteur ; Jia Yu, Auteur Année de publication : 2012 Article en page(s) : pp. 7349-7354 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Macroporosity Extract Purification Résumé : In the present study, the performance and separation characteristics of six macroporous resins for the enrichment and purification of total flavonoid C-glycosides (vicenin-2, 1; isoschaftoside, 2; schaftoside, 3) from Abrus mollis extracts have been evaluated. The adsorption and desorption properties of total flavonoid C-glycosides were studied on macroporous resins, including HPD-100, HPD-450, AB-8, HPD-600, DA-201, and HPD-417. According to the results, HPD-100 resin showed the best adsorption and desorption capacity for these three flavonoid C-glycosides among six resins. Adsorption isotherms were constructed on HPD-100 resin and fitted well to the Langmuir (R2 > 0.99) and Freundlich (R2 > 0.89, 0.1 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948475
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7349-7354[article] Enrichment and purification of total flavonoid C - glycosides from abrus mollis extracts with macroporous resins [texte imprimé] / Huibin Du, Auteur ; Hao Wang, Auteur ; Jia Yu, Auteur . - 2012 . - pp. 7349-7354.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7349-7354
Mots-clés : Macroporosity Extract Purification Résumé : In the present study, the performance and separation characteristics of six macroporous resins for the enrichment and purification of total flavonoid C-glycosides (vicenin-2, 1; isoschaftoside, 2; schaftoside, 3) from Abrus mollis extracts have been evaluated. The adsorption and desorption properties of total flavonoid C-glycosides were studied on macroporous resins, including HPD-100, HPD-450, AB-8, HPD-600, DA-201, and HPD-417. According to the results, HPD-100 resin showed the best adsorption and desorption capacity for these three flavonoid C-glycosides among six resins. Adsorption isotherms were constructed on HPD-100 resin and fitted well to the Langmuir (R2 > 0.99) and Freundlich (R2 > 0.89, 0.1 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948475 Exemplaires
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Titre : Onsite CO2 capture from flue gas by an adsorption process in a coal - fired power plant Type de document : texte imprimé Auteurs : Zhen Liu, Auteur ; Lu Wang, Auteur ; Xiangming Kong, Auteur Année de publication : 2012 Article en page(s) : pp. 7355–7363 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Flue gas Adsorption Résumé : The feasibility and efficiency of adsorption technology were evaluated experimentally and theoretically for CO2 capture from the flue gas in an existing coal-fired power plant, where a three-bed VPSA unit was set up to test 282 kg of adsorbent materials. In this work, the experimental results are reported for zeolite 5A as the adsorbent. The composition of the flue gas after dehydration was 15.0 vol % CO2, 76.5 vol % N2, and 8.5 vol % O2. With a three-bed seven-step VPSA process including rinse and pressure equalization steps, 85% CO2 was obtained with recovery of 79% from flue gas at a feed flow rate of 46.0 Nm3/h. The experimentally measured energy consumption was 2.37 MJ/(kg of CO2). The experimental work was compared with numerical simulations through the multibed VPSA modeling framework developed in a previous work. The simulated results were found to agree well with the experimental results. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3005308
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7355–7363[article] Onsite CO2 capture from flue gas by an adsorption process in a coal - fired power plant [texte imprimé] / Zhen Liu, Auteur ; Lu Wang, Auteur ; Xiangming Kong, Auteur . - 2012 . - pp. 7355–7363.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7355–7363
Mots-clés : Flue gas Adsorption Résumé : The feasibility and efficiency of adsorption technology were evaluated experimentally and theoretically for CO2 capture from the flue gas in an existing coal-fired power plant, where a three-bed VPSA unit was set up to test 282 kg of adsorbent materials. In this work, the experimental results are reported for zeolite 5A as the adsorbent. The composition of the flue gas after dehydration was 15.0 vol % CO2, 76.5 vol % N2, and 8.5 vol % O2. With a three-bed seven-step VPSA process including rinse and pressure equalization steps, 85% CO2 was obtained with recovery of 79% from flue gas at a feed flow rate of 46.0 Nm3/h. The experimentally measured energy consumption was 2.37 MJ/(kg of CO2). The experimental work was compared with numerical simulations through the multibed VPSA modeling framework developed in a previous work. The simulated results were found to agree well with the experimental results. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3005308 Exemplaires
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Titre : Mass transfer from single drops and the influence of temperature Type de document : texte imprimé Auteurs : Javad Saien, Auteur ; Shabnam Daliri, Auteur Année de publication : 2012 Article en page(s) : pp. 7364–7372 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Mass transfer Résumé : Temperature can alter the performance of conventional liquid–liquid extraction columns in which one phase is dispersed inside another phase. In this research, the influence of temperature on the extraction process was investigated using a toluene–acetic acid–water chemical system with dominant mass transfer resistance in the organic phase. Single drop experiments with a range of drop size within 2.49–3.77 mm and temperature within 15–40 °C were performed. Results demonstrate significant impact of temperature on the rate of mass transfer with an average enhancement of 93.6% in overall mass transfer coefficient while small drops are benefited more. Having lower contributions by drop size and terminal velocity, the extraction efficiency is the most effective term in this regard which itself is increased by increasing molecular diffusivity in the organic dispersed phase. For the aim of modeling, effective diffusivity was substituted for molecular diffusivity in Newman’s equation and consequently, a reliable empirical equation was derived for the enhancement factor of diffusivity as a function of dimensionless variables. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300649d
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7364–7372[article] Mass transfer from single drops and the influence of temperature [texte imprimé] / Javad Saien, Auteur ; Shabnam Daliri, Auteur . - 2012 . - pp. 7364–7372.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7364–7372
Mots-clés : Mass transfer Résumé : Temperature can alter the performance of conventional liquid–liquid extraction columns in which one phase is dispersed inside another phase. In this research, the influence of temperature on the extraction process was investigated using a toluene–acetic acid–water chemical system with dominant mass transfer resistance in the organic phase. Single drop experiments with a range of drop size within 2.49–3.77 mm and temperature within 15–40 °C were performed. Results demonstrate significant impact of temperature on the rate of mass transfer with an average enhancement of 93.6% in overall mass transfer coefficient while small drops are benefited more. Having lower contributions by drop size and terminal velocity, the extraction efficiency is the most effective term in this regard which itself is increased by increasing molecular diffusivity in the organic dispersed phase. For the aim of modeling, effective diffusivity was substituted for molecular diffusivity in Newman’s equation and consequently, a reliable empirical equation was derived for the enhancement factor of diffusivity as a function of dimensionless variables. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300649d Exemplaires
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Titre : Atomically detailed modeling of metal organic frameworks for adsorption, diffusion, and separation of noble gas mixtures Type de document : texte imprimé Auteurs : Yeliz Gurdal, Auteur ; Seda Keskin, Auteur Année de publication : 2012 Article en page(s) : pp. 7373–7382 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Metal organic Adsorption Gas Résumé : Atomically detailed simulations have been widely used to assess gas storage and gas separation properties of metal organic frameworks (MOFs). We used molecular simulations to examine adsorption, diffusion, and separation of noble gas mixtures in MOFs. Adsorption isotherms and self-diffusivities of Xe/Kr and Xe/Ar mixtures at various compositions in ten representative MOFs were computed using grand canonical Monte Carlo and equilibrium molecular dynamics simulations. Several properties of MOFs such as adsorption selectivity, working capacity, diffusion selectivity, permeation selectivity, and gas permeability were evaluated and compared with those of traditional nanoporous materials. Results showed that MOFs are promising candidates for Xe/Kr and Xe/Ar separations due to their high Xe selectivity and permeability. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300766s
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7373–7382[article] Atomically detailed modeling of metal organic frameworks for adsorption, diffusion, and separation of noble gas mixtures [texte imprimé] / Yeliz Gurdal, Auteur ; Seda Keskin, Auteur . - 2012 . - pp. 7373–7382.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7373–7382
Mots-clés : Metal organic Adsorption Gas Résumé : Atomically detailed simulations have been widely used to assess gas storage and gas separation properties of metal organic frameworks (MOFs). We used molecular simulations to examine adsorption, diffusion, and separation of noble gas mixtures in MOFs. Adsorption isotherms and self-diffusivities of Xe/Kr and Xe/Ar mixtures at various compositions in ten representative MOFs were computed using grand canonical Monte Carlo and equilibrium molecular dynamics simulations. Several properties of MOFs such as adsorption selectivity, working capacity, diffusion selectivity, permeation selectivity, and gas permeability were evaluated and compared with those of traditional nanoporous materials. Results showed that MOFs are promising candidates for Xe/Kr and Xe/Ar separations due to their high Xe selectivity and permeability. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300766s Exemplaires
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Titre : Flow of pellet and coke particles in and from a fixed chute Type de document : texte imprimé Auteurs : Yaowei Yu, Auteur ; Henrik Saxén, Auteur Année de publication : 2012 Article en page(s) : pp. 7383-7397 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Pellet Résumé : The velocity distribution of particles in the chute of a bell-less charging equipment affects the burden segregation and distribution in the blast furnace. This paper studies the angular and translational velocity distributions of particles during their flow along and from an inclined fixed chute through experiments and simulations by the discrete element method. The simulation results are validated by comparison with observed mass fractions collected in boxes at the end of the falling trajectories and by measuring the average velocity of particles along the chute. Angular and translational velocity distributions along and across the chute are reported, and the effect of the particle size distribution and particle shape are studied. The results show that the angular velocity distribution in cross sections of the chute exhibits a V-shaped appearance, that is, opposite the distribution of the translational velocity. The mass fractions of the particles in the trajectories show a similar distribution, regardless of particle size and shape. The mean angular velocity increases and the translational velocity decreases with a growing particle size distribution, while particle shape only influences the angular velocity. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201362n
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7383-7397[article] Flow of pellet and coke particles in and from a fixed chute [texte imprimé] / Yaowei Yu, Auteur ; Henrik Saxén, Auteur . - 2012 . - pp. 7383-7397.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7383-7397
Mots-clés : Pellet Résumé : The velocity distribution of particles in the chute of a bell-less charging equipment affects the burden segregation and distribution in the blast furnace. This paper studies the angular and translational velocity distributions of particles during their flow along and from an inclined fixed chute through experiments and simulations by the discrete element method. The simulation results are validated by comparison with observed mass fractions collected in boxes at the end of the falling trajectories and by measuring the average velocity of particles along the chute. Angular and translational velocity distributions along and across the chute are reported, and the effect of the particle size distribution and particle shape are studied. The results show that the angular velocity distribution in cross sections of the chute exhibits a V-shaped appearance, that is, opposite the distribution of the translational velocity. The mass fractions of the particles in the trajectories show a similar distribution, regardless of particle size and shape. The mean angular velocity increases and the translational velocity decreases with a growing particle size distribution, while particle shape only influences the angular velocity. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201362n Exemplaires
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Titre : Semianalytical bubble - flow models for the development of a novel bubble - column simulator Type de document : texte imprimé Auteurs : Waldo Coetzee, Auteur ; Roelof L. J. Coetzer, Auteur ; Randhir Rawatlal, Auteur Année de publication : 2012 Article en page(s) : pp. 7398-7409 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Bubble column Modeling flow Résumé : The simulation of bubble columns is a computationally expensive task because of the complexity of the hydrodynamics. A novel bubble-column simulation approach attempts to increase the computational efficiency by accounting for the flow regions around individual bubbles with an algebraic flow model. To improve the accuracy and reduce the number of parameters of the flow model, the linear combination of the creeping and potential flow analytical solutions is considered as a first approximation, which is found to accurately model large portions of the flow field within the considered operating range (Rc ≤ 270). The residual consists of significant nonlinear features, e.g., bubble wake, for which two statistically based strategies, i.e., Design and Analysis of Computer Experiments (DACE) and regression with empirical models, are evaluated. Both resulted in good fits, with the DACE strategy making fewer assumptions about the data, however, requiring more parameters. The combination of analytical and empirical models is therefore recommended for use as an accurate algebraic approximation of the flow field. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948480
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7398-7409[article] Semianalytical bubble - flow models for the development of a novel bubble - column simulator [texte imprimé] / Waldo Coetzee, Auteur ; Roelof L. J. Coetzer, Auteur ; Randhir Rawatlal, Auteur . - 2012 . - pp. 7398-7409.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7398-7409
Mots-clés : Bubble column Modeling flow Résumé : The simulation of bubble columns is a computationally expensive task because of the complexity of the hydrodynamics. A novel bubble-column simulation approach attempts to increase the computational efficiency by accounting for the flow regions around individual bubbles with an algebraic flow model. To improve the accuracy and reduce the number of parameters of the flow model, the linear combination of the creeping and potential flow analytical solutions is considered as a first approximation, which is found to accurately model large portions of the flow field within the considered operating range (Rc ≤ 270). The residual consists of significant nonlinear features, e.g., bubble wake, for which two statistically based strategies, i.e., Design and Analysis of Computer Experiments (DACE) and regression with empirical models, are evaluated. Both resulted in good fits, with the DACE strategy making fewer assumptions about the data, however, requiring more parameters. The combination of analytical and empirical models is therefore recommended for use as an accurate algebraic approximation of the flow field. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948480 Exemplaires
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Titre : Thermodynamics of nonferroelectric mixtures under the influence of electrostatic fields Type de document : texte imprimé Auteurs : Wilson A. Canas-Marín, Auteur Année de publication : 2012 Article en page(s) : pp. 7410-7417 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Thermodynamic Nonferroelectric Electrostatic Résumé : A thermodynamic framework for modeling the phase equilibrium of nonferroelectric pure components and multicomponent liquid, vapor, or solid mixtures under the influence of an electrostatic field is presented. Then, this framework is used for the first time to predict the effect of this kind of field on the critical temperature and critical pressure of a multicomponent hydrocarbon mixture, giving as a result that the critical properties exhibit a downward shift with the strength of the electrostatic field applied and then a final upward shift for very huge values of the field. For these calculations an alternative mathematical expression to determine the electric susceptibilities of mixtures, and its respective compositional derivatives, is also presented; its predictive capability is illustrated by using experimental data of binary systems. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3002149
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7410-7417[article] Thermodynamics of nonferroelectric mixtures under the influence of electrostatic fields [texte imprimé] / Wilson A. Canas-Marín, Auteur . - 2012 . - pp. 7410-7417.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7410-7417
Mots-clés : Thermodynamic Nonferroelectric Electrostatic Résumé : A thermodynamic framework for modeling the phase equilibrium of nonferroelectric pure components and multicomponent liquid, vapor, or solid mixtures under the influence of an electrostatic field is presented. Then, this framework is used for the first time to predict the effect of this kind of field on the critical temperature and critical pressure of a multicomponent hydrocarbon mixture, giving as a result that the critical properties exhibit a downward shift with the strength of the electrostatic field applied and then a final upward shift for very huge values of the field. For these calculations an alternative mathematical expression to determine the electric susceptibilities of mixtures, and its respective compositional derivatives, is also presented; its predictive capability is illustrated by using experimental data of binary systems. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3002149 Exemplaires
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Titre : Quantitative research on the vaporization and decomposition of [EMIM] [Tf2N] by thermogravimetric analysis – mass spectrometry Type de document : texte imprimé Auteurs : Yu Chen, Auteur ; Yuanyuan Cao, Auteur ; Yang Shi, Auteur Année de publication : 2012 Article en page(s) : pp. 7418–7427 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Thermogravimetric analysis Mass spectrometry Résumé : The thermal stability of [EMIM][Tf2N] was investigated by thermogravimetric analysis–mass spectrometry (TG–MS) in this study. It showed that [EMIM][Tf2N] decomposed at temperatures over 350 °C by Hoffman elimination and substitution of nucleophilic mechanisms (SN, including the unimolecular substitution nucleophilic reaction SN1 and the bimolecular substitution nucleophilic reaction SN2). The instability of [EMIM][Tf2N] is induced by decomposition of the anion [Tf2N] to a more nucleophilic group, such as NH2 and F, and then methyl and/or ethyl in the imidazolium cation are attacked by those groups of relatively high nucleophilic activity. Mass loss of [EMIM][Tf2N] in a nitrogen atmosphere can be attributed to its decomposition and/or vaporization. The ratios of decomposition and vaporization (Dec/Vap), elimination and SN (Elim/SN), and SN2/SN1 for [EMIM][Tf2N] were approximately determined by TG–MS. The thermal stability including both decomposition and vaporization of [EMIM][Tf2N] decreases with an increase of the temperature, while decomposition is more sensitive to the temperature than evaporation. Vaporization of [EMIM][Tf2N] dominates the mass loss at temperatures below 350 °C, while decomposition dominates the mass loss at temperatures over 350 °C. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300247v
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7418–7427[article] Quantitative research on the vaporization and decomposition of [EMIM] [Tf2N] by thermogravimetric analysis – mass spectrometry [texte imprimé] / Yu Chen, Auteur ; Yuanyuan Cao, Auteur ; Yang Shi, Auteur . - 2012 . - pp. 7418–7427.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7418–7427
Mots-clés : Thermogravimetric analysis Mass spectrometry Résumé : The thermal stability of [EMIM][Tf2N] was investigated by thermogravimetric analysis–mass spectrometry (TG–MS) in this study. It showed that [EMIM][Tf2N] decomposed at temperatures over 350 °C by Hoffman elimination and substitution of nucleophilic mechanisms (SN, including the unimolecular substitution nucleophilic reaction SN1 and the bimolecular substitution nucleophilic reaction SN2). The instability of [EMIM][Tf2N] is induced by decomposition of the anion [Tf2N] to a more nucleophilic group, such as NH2 and F, and then methyl and/or ethyl in the imidazolium cation are attacked by those groups of relatively high nucleophilic activity. Mass loss of [EMIM][Tf2N] in a nitrogen atmosphere can be attributed to its decomposition and/or vaporization. The ratios of decomposition and vaporization (Dec/Vap), elimination and SN (Elim/SN), and SN2/SN1 for [EMIM][Tf2N] were approximately determined by TG–MS. The thermal stability including both decomposition and vaporization of [EMIM][Tf2N] decreases with an increase of the temperature, while decomposition is more sensitive to the temperature than evaporation. Vaporization of [EMIM][Tf2N] dominates the mass loss at temperatures below 350 °C, while decomposition dominates the mass loss at temperatures over 350 °C. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300247v Exemplaires
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Titre : Molecular modeling and simulation of vapor – liquid equilibria of ethylene oxide, ethylene glycol, and water as well as their binary mixtures Type de document : texte imprimé Auteurs : Y.-L. Huang, Auteur ; T. Merker, Auteur ; M. Heilig, Auteur Année de publication : 2012 Article en page(s) : pp. 7428–7440 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Simulation Vapor liquid aquilibria Résumé : Mixtures containing ethylene oxide are technically highly relevant but hazardous so that typically only few reliable experimental data are available. They are therefore interesting candidates for the application of molecular modeling and simulation to predict thermodynamic properties. The industrially most important ethylene oxide containing mixtures are those with water and ethylene glycol. An excellent molecular model for ethylene oxide is available from prior work. Because the molecular models for water from the literature do not yield satisfactory results for the vapor–liquid equilibrium over a wide temperature range, a new water model is developed. Furthermore, also a new molecular model for ethylene glycol is developed. The models for ethylene glycol and water show mean unsigned deviations with respect to experimental data, considering the whole temperature range from triple point to critical point, of 0.8 and 1.1% for the saturated liquid density, 4.8 and 7.2% for the vapor pressure, and 13.4 and 2.8% for the enthalpy of vaporization, respectively. Vapor–liquid equilibria of all three binary mixtures are determined by molecular simulation, and in general, a good agreement is found with the available experimental data. The models can be used for subsequent predictions at other conditions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300248z
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7428–7440[article] Molecular modeling and simulation of vapor – liquid equilibria of ethylene oxide, ethylene glycol, and water as well as their binary mixtures [texte imprimé] / Y.-L. Huang, Auteur ; T. Merker, Auteur ; M. Heilig, Auteur . - 2012 . - pp. 7428–7440.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7428–7440
Mots-clés : Simulation Vapor liquid aquilibria Résumé : Mixtures containing ethylene oxide are technically highly relevant but hazardous so that typically only few reliable experimental data are available. They are therefore interesting candidates for the application of molecular modeling and simulation to predict thermodynamic properties. The industrially most important ethylene oxide containing mixtures are those with water and ethylene glycol. An excellent molecular model for ethylene oxide is available from prior work. Because the molecular models for water from the literature do not yield satisfactory results for the vapor–liquid equilibrium over a wide temperature range, a new water model is developed. Furthermore, also a new molecular model for ethylene glycol is developed. The models for ethylene glycol and water show mean unsigned deviations with respect to experimental data, considering the whole temperature range from triple point to critical point, of 0.8 and 1.1% for the saturated liquid density, 4.8 and 7.2% for the vapor pressure, and 13.4 and 2.8% for the enthalpy of vaporization, respectively. Vapor–liquid equilibria of all three binary mixtures are determined by molecular simulation, and in general, a good agreement is found with the available experimental data. The models can be used for subsequent predictions at other conditions. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300248z Exemplaires
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Titre : Biomediated silver nanoparticles for the highly selective copper (II) ion sensor applications Type de document : texte imprimé Auteurs : C. Joseph Kirubaharan, Auteur ; D. Kalpana, Auteur ; Yang Soo Lee, Auteur Année de publication : 2012 Article en page(s) : pp. 7441–7446 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Silver nanoparticles Résumé : Nanoparticles synthesis is an evergreen research field of 21st century in which the connotation of the biomediated experimental process is highly imperative. Biomediated silver nanoparticles were synthesized with the aid of an eco-friendly biomaterial, namely, aqueous Azadirachta indica extract. The effect of pH and temperature on the formation of silver nanoparticles was analyzed. Formation of the silver nanoparticles was verified by surface plasmon spectra using a UV–vis spectrophotometer. Morphology and crystalline structure of the prepared silver nanoparticles were characterized by TEM and XRD techniques, respectively. Furthermore, the biomediated silver nanoparticles without any surface modification were used for the heavy metal ion sensors in aqueous media. The prepared silver nanoparticles were successful in detecting even the minimal amount of heavy metal copper(II) ion and exhibited excellent specific metal ion selectivity. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3003232
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7441–7446[article] Biomediated silver nanoparticles for the highly selective copper (II) ion sensor applications [texte imprimé] / C. Joseph Kirubaharan, Auteur ; D. Kalpana, Auteur ; Yang Soo Lee, Auteur . - 2012 . - pp. 7441–7446.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7441–7446
Mots-clés : Silver nanoparticles Résumé : Nanoparticles synthesis is an evergreen research field of 21st century in which the connotation of the biomediated experimental process is highly imperative. Biomediated silver nanoparticles were synthesized with the aid of an eco-friendly biomaterial, namely, aqueous Azadirachta indica extract. The effect of pH and temperature on the formation of silver nanoparticles was analyzed. Formation of the silver nanoparticles was verified by surface plasmon spectra using a UV–vis spectrophotometer. Morphology and crystalline structure of the prepared silver nanoparticles were characterized by TEM and XRD techniques, respectively. Furthermore, the biomediated silver nanoparticles without any surface modification were used for the heavy metal ion sensors in aqueous media. The prepared silver nanoparticles were successful in detecting even the minimal amount of heavy metal copper(II) ion and exhibited excellent specific metal ion selectivity. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3003232 Exemplaires
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Titre : Pressure drop models of seepage catalytic packing internal for catalytic distillation column Type de document : texte imprimé Auteurs : Xin Gao, Auteur ; Xingang Li, Auteur ; Rui Zhang, Auteur Année de publication : 2012 Article en page(s) : pp. 7447-7452 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Distillation column Catalytic reaction Modeling Hydrodynamics Pressure drop Résumé : A seepage catalytic packing internal (SCPI) consisting of catalyst containers with avert-overflow baffles and corrugated metal sheets was developed for a catalytic distillation column. By changing the width ratio (Rcc/cms) of the catalyst containers (CC) relative to corrugated metal sheets (CMS), the SCPI developed in this work can be suitable to various reaction and separation zones in different catalytic distillation processes. The influence of the Rcc/cms, a significant factor influencing the pressure drop, also was studied. The flooding behaviors and pressure drop were evaluated using cold model experiments in the column (600 mm in diameter x 1500 mm height); the results were compared with that of the catalytic packing typically used in catalytic distillation. A model for predicting the pressure drop of SCPI was developed and compared with experimental results. Results show that the pressure drop was decreased with decreases of Rcc/cms. The results from this work are valuable in the design and scale-up of SCPI in catalytic distillation columns. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948485
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7447-7452[article] Pressure drop models of seepage catalytic packing internal for catalytic distillation column [texte imprimé] / Xin Gao, Auteur ; Xingang Li, Auteur ; Rui Zhang, Auteur . - 2012 . - pp. 7447-7452.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7447-7452
Mots-clés : Distillation column Catalytic reaction Modeling Hydrodynamics Pressure drop Résumé : A seepage catalytic packing internal (SCPI) consisting of catalyst containers with avert-overflow baffles and corrugated metal sheets was developed for a catalytic distillation column. By changing the width ratio (Rcc/cms) of the catalyst containers (CC) relative to corrugated metal sheets (CMS), the SCPI developed in this work can be suitable to various reaction and separation zones in different catalytic distillation processes. The influence of the Rcc/cms, a significant factor influencing the pressure drop, also was studied. The flooding behaviors and pressure drop were evaluated using cold model experiments in the column (600 mm in diameter x 1500 mm height); the results were compared with that of the catalytic packing typically used in catalytic distillation. A model for predicting the pressure drop of SCPI was developed and compared with experimental results. Results show that the pressure drop was decreased with decreases of Rcc/cms. The results from this work are valuable in the design and scale-up of SCPI in catalytic distillation columns. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=25948485 Exemplaires
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Titre : A highly breathable organic / inorganic barrier material that blocks the passage of mustard agent simulants Type de document : texte imprimé Auteurs : Yeny C. Hudiono, Auteur ; A. Lee Miller, Auteur ; Phillip W. Gibson, Auteur Année de publication : 2012 Article en page(s) : pp. 7453–7456 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Composite material Résumé : Garment materials that provide protection against exposure to toxic chemical warfare agents (CWAs) not only require the ability to block the passage of these toxic compounds in vapor form but also the ability to transport water vapor to allow cooling for the wearer. Only a very limited number of examples of such “breathable” CWA barrier materials are known. A new type of reactive organic/inorganic composite film material is presented that has a very high water vapor transport rate (>1800 g m–2 day–1 for a 220-μm-thick film) and the ability to completely block penetration of the mustard agent simulant, 2-chloroethyl ethyl sulfide (CEES), after 22 h of continuous exposure. This new composite material is based on two components: (1) a cross-linked, diol-functionalized room-temperature ionic liquid polymer that serves as a dense, flexible hydrophilic matrix, and (2) a basic zeolite (sodium zeolite-Y (NaY)) that serves as an inexpensive, nucleophilic additive that chemically degrades the CEES as it enters the film. Preliminary FT-IR studies on this new reactive barrier material suggest that the OH groups on the ionic polymer not only facilitates water vapor transport but may also help activate mustard-type vapors for reaction with the imbedded NaY. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202977e
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7453–7456[article] A highly breathable organic / inorganic barrier material that blocks the passage of mustard agent simulants [texte imprimé] / Yeny C. Hudiono, Auteur ; A. Lee Miller, Auteur ; Phillip W. Gibson, Auteur . - 2012 . - pp. 7453–7456.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 21 (Mai 2012) . - pp. 7453–7456
Mots-clés : Composite material Résumé : Garment materials that provide protection against exposure to toxic chemical warfare agents (CWAs) not only require the ability to block the passage of these toxic compounds in vapor form but also the ability to transport water vapor to allow cooling for the wearer. Only a very limited number of examples of such “breathable” CWA barrier materials are known. A new type of reactive organic/inorganic composite film material is presented that has a very high water vapor transport rate (>1800 g m–2 day–1 for a 220-μm-thick film) and the ability to completely block penetration of the mustard agent simulant, 2-chloroethyl ethyl sulfide (CEES), after 22 h of continuous exposure. This new composite material is based on two components: (1) a cross-linked, diol-functionalized room-temperature ionic liquid polymer that serves as a dense, flexible hydrophilic matrix, and (2) a basic zeolite (sodium zeolite-Y (NaY)) that serves as an inexpensive, nucleophilic additive that chemically degrades the CEES as it enters the film. Preliminary FT-IR studies on this new reactive barrier material suggest that the OH groups on the ionic polymer not only facilitates water vapor transport but may also help activate mustard-type vapors for reaction with the imbedded NaY. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202977e Exemplaires
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