Nos Abonnements
Ressources Électroniques
|
[n° ou bulletin]
[n° ou bulletin]
Vol. 50 N° 21 - Novembre 2011 [texte imprimé] . - 2011 . - p. 11771-12310 : ill. ; 28 cm. Chemical engineering Langues : Anglais (eng)
|
Exemplaires
| Code-barres | Cote | Support | Localisation | Section | Disponibilité |
|---|---|---|---|---|---|
| aucun exemplaire | |||||
|
Dépouillements
Ajouter le résultat dans votre panierDegradation of tributyl phosphate using nanopowders of iron and iron – nickel under the influence of a static magnetic field / Ritu D. Ambashta in Industrial & engineering chemistry research, Vol. 50 N° 21 (Novembre 2011)
Titre : Degradation of tributyl phosphate using nanopowders of iron and iron – nickel under the influence of a static magnetic field Type de document : texte imprimé Auteurs : Ritu D. Ambashta, Auteur ; Eveliina Repo, Auteur ; Mika Sillanpaa, Auteur Année de publication : 2011 Article en page(s) : pp. 11771-11777 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Magnetic field Résumé : A novel method for the degradation of tributyl phosphate was investigated through the use of nanopowders of iron and iron-nickel. A combination of magnetic field and sonication was used to induce degradation. Using a tributyl phosphate concentration of 300 ppm at pH 4, the Fenton reaction was initiated in the presence of sonication and a reduction in organic carbon content of up to 50% could be created under an induced magnetic field of 0.7 T. The magnetic properties of powders after sonication treatment, in the presence and absence of a magnetic field, were observed to be different. Different degradation mechanisms were proposed under the influence of varying induced magnetic field for iron and iron-nickel. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697492
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11771-11777[article] Degradation of tributyl phosphate using nanopowders of iron and iron – nickel under the influence of a static magnetic field [texte imprimé] / Ritu D. Ambashta, Auteur ; Eveliina Repo, Auteur ; Mika Sillanpaa, Auteur . - 2011 . - pp. 11771-11777.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11771-11777
Mots-clés : Magnetic field Résumé : A novel method for the degradation of tributyl phosphate was investigated through the use of nanopowders of iron and iron-nickel. A combination of magnetic field and sonication was used to induce degradation. Using a tributyl phosphate concentration of 300 ppm at pH 4, the Fenton reaction was initiated in the presence of sonication and a reduction in organic carbon content of up to 50% could be created under an induced magnetic field of 0.7 T. The magnetic properties of powders after sonication treatment, in the presence and absence of a magnetic field, were observed to be different. Different degradation mechanisms were proposed under the influence of varying induced magnetic field for iron and iron-nickel. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697492 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Novel semi - interpenetrating microspheres of dextran - grafted - acrylamide and poly (vinyl alcohol) for controlled release of abacavir sulfate Type de document : texte imprimé Auteurs : Anita G. Sullad, Auteur ; Lata S. Manjeshwar, Auteur ; Tejraj M. Aminabhavi, Auteur Année de publication : 2011 Article en page(s) : pp. 11778–11784 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Microspheres Dextran Résumé : A novel drug delivery system using semi-interpenetrating (semi-IPN) microspheres of dextran-grafted-acrylamide (Dex-g-AAm) and poly(vinyl alcohol) (PVA) was prepared in the size range of 80–100 μm by emulsion cross-linking for investigating controlled release (CR) of an anti-HIV agent, abacavir sulfate. The graft copolymer was confirmed by Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The microspheres were characterized for morphology, swelling, and in vitro release of abacavir sulfate in pH 1.2 and 7.4 buffer media to display the effect of drug release in acidic and alkaline conditions. The kinetics of in vitro release was analyzed using the empirical equations to understand the nature of release mechanism. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2006438
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11778–11784[article] Novel semi - interpenetrating microspheres of dextran - grafted - acrylamide and poly (vinyl alcohol) for controlled release of abacavir sulfate [texte imprimé] / Anita G. Sullad, Auteur ; Lata S. Manjeshwar, Auteur ; Tejraj M. Aminabhavi, Auteur . - 2011 . - pp. 11778–11784.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11778–11784
Mots-clés : Microspheres Dextran Résumé : A novel drug delivery system using semi-interpenetrating (semi-IPN) microspheres of dextran-grafted-acrylamide (Dex-g-AAm) and poly(vinyl alcohol) (PVA) was prepared in the size range of 80–100 μm by emulsion cross-linking for investigating controlled release (CR) of an anti-HIV agent, abacavir sulfate. The graft copolymer was confirmed by Fourier transform infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The microspheres were characterized for morphology, swelling, and in vitro release of abacavir sulfate in pH 1.2 and 7.4 buffer media to display the effect of drug release in acidic and alkaline conditions. The kinetics of in vitro release was analyzed using the empirical equations to understand the nature of release mechanism. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2006438 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Origin of the difference in structural behavior of poly(acrylic acid) and poly(methacrylic acid) in aqueous solution discerned by explicit - solvent explicit - ion MD simulations Type de document : texte imprimé Auteurs : Muralidharan S. Sulatha, Auteur ; Upendra Natarajan, Auteur Année de publication : 2011 Article en page(s) : pp. 11785-11796 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Aqueous solution Résumé : The conformational and hydration behavior ofpoly(acrylic acid) (PAA) and poly(methacrylic acid) (PMA) in dilute aqueous solution, as a function of charge density, is studied using two different sets of force field parameters: FF-1 and FF-2. The two sets of force field parameters predict similar correlation distances between carboxylate groups and water. The simulations bring about the difference in the interaction of the counterions with the polyions PAA and PMA. FF-1 predicts that upon neutralization PMA shows stronger correlation with Na+ ions in comparison to PAA in aqueous solution. This difference in behavior agrees with the fact that, in poor solvents, the polyelectrolyte chain and the counterions interact strongly. The atomistic simulations using FF-1 parameters presented here bring about the difference in the conformational behaviors of PAA and PMA and the effect of solvent quality on the polyacrylate chain backbone structure. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697494
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11785-11796[article] Origin of the difference in structural behavior of poly(acrylic acid) and poly(methacrylic acid) in aqueous solution discerned by explicit - solvent explicit - ion MD simulations [texte imprimé] / Muralidharan S. Sulatha, Auteur ; Upendra Natarajan, Auteur . - 2011 . - pp. 11785-11796.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11785-11796
Mots-clés : Aqueous solution Résumé : The conformational and hydration behavior ofpoly(acrylic acid) (PAA) and poly(methacrylic acid) (PMA) in dilute aqueous solution, as a function of charge density, is studied using two different sets of force field parameters: FF-1 and FF-2. The two sets of force field parameters predict similar correlation distances between carboxylate groups and water. The simulations bring about the difference in the interaction of the counterions with the polyions PAA and PMA. FF-1 predicts that upon neutralization PMA shows stronger correlation with Na+ ions in comparison to PAA in aqueous solution. This difference in behavior agrees with the fact that, in poor solvents, the polyelectrolyte chain and the counterions interact strongly. The atomistic simulations using FF-1 parameters presented here bring about the difference in the conformational behaviors of PAA and PMA and the effect of solvent quality on the polyacrylate chain backbone structure. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697494 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Colon targeting of 5 - fluorouracil using polyethylene glycol cross - linked chitosan microspheres enteric coated with cellulose acetate phthalate Type de document : texte imprimé Auteurs : Kuntal Ganguly, Auteur ; Tejraj M. Aminabhavi, Auteur ; Anandrao R. Kulkarni, Auteur Année de publication : 2011 Article en page(s) : pp. 11797-11807 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Microsphere Résumé : Polyethylene glycol cross-linked chitosan microspheres loaded with 5-fluorouracil (5-FU) have been prepared by emulsion cross-linking and enteric coated with cellulose acetate phthalate (CAP) to facilitate direct targeting of S-FU to the colon. Spherical microspheres with surface ridges to moderate smooth surfaces loaded with different concentrations (i.e., 10, 20, and 30% w/w) of 5-FU have been evaluated for encapsulation efficiency, swelling and in vitro release characteristics in simulated gastro intestinal tract (GIT) conditions for both enteric coated and uncoated microspheres. In acidic pH, 8 to 17%, but in alkaline pH, approximately 88 to 97% of 5-FU was released with CAP coated microspheres. In the case of uncoated microspheres, 46 to 77% release of 5-FU occurred in acidic pH, but 93 to 97% was released in alkaline pH. The study demonstrates that chitosan coating with CAP and cross-linking with PEG is necessary for targeted delivery of 5-FU to the colon. The coated microspheres are found to be more suitable for colon targeting than the uncoated formulations as the former prolonged the 5-FU release from 6 to 12 h by protecting 5-FU in acidic environment of the stomach. Kinetics of drug release as investigated by empirical equations suggested Super Case II transport mechanism. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697495
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11797-11807[article] Colon targeting of 5 - fluorouracil using polyethylene glycol cross - linked chitosan microspheres enteric coated with cellulose acetate phthalate [texte imprimé] / Kuntal Ganguly, Auteur ; Tejraj M. Aminabhavi, Auteur ; Anandrao R. Kulkarni, Auteur . - 2011 . - pp. 11797-11807.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11797-11807
Mots-clés : Microsphere Résumé : Polyethylene glycol cross-linked chitosan microspheres loaded with 5-fluorouracil (5-FU) have been prepared by emulsion cross-linking and enteric coated with cellulose acetate phthalate (CAP) to facilitate direct targeting of S-FU to the colon. Spherical microspheres with surface ridges to moderate smooth surfaces loaded with different concentrations (i.e., 10, 20, and 30% w/w) of 5-FU have been evaluated for encapsulation efficiency, swelling and in vitro release characteristics in simulated gastro intestinal tract (GIT) conditions for both enteric coated and uncoated microspheres. In acidic pH, 8 to 17%, but in alkaline pH, approximately 88 to 97% of 5-FU was released with CAP coated microspheres. In the case of uncoated microspheres, 46 to 77% release of 5-FU occurred in acidic pH, but 93 to 97% was released in alkaline pH. The study demonstrates that chitosan coating with CAP and cross-linking with PEG is necessary for targeted delivery of 5-FU to the colon. The coated microspheres are found to be more suitable for colon targeting than the uncoated formulations as the former prolonged the 5-FU release from 6 to 12 h by protecting 5-FU in acidic environment of the stomach. Kinetics of drug release as investigated by empirical equations suggested Super Case II transport mechanism. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697495 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Simultaneous decomposition and fixation of F - gases using waste concrete Type de document : texte imprimé Auteurs : Atsushi Iizuka, Auteur ; Hiroaki Ishizaki, Auteur ; Atsushi Mizukoshi, Auteur Année de publication : 2011 Article en page(s) : pp. 11808-11814 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Fixation gases Waste concrete Résumé : Experimental study was conducted on the simultaneous process of decomposition and fixation of fluoride of F-gases. HFC-134a, a hydrofluorocarbon (HFC), used most widely, was selected as a model gas, and its decomposition performances were examined in a tube type reactor with and without waste concrete powder. Decomposition of HFC-134a was observed at temperatures above 500 °C, while no thermal decomposition occurred below 750 °C without waste concrete. The results for the differential type reactor with high SV demonstrated that the calcium reaction ratio in the waste concrete reached about 50 mol % after 10 min of reaction. Thermal decomposition of HFC-134a was promoted by increasing the reaction temperature. The particle size of the waste concrete within the range studied scarcely affected the decomposition rate. An increase in HFC-134a concentration resulted in a higher calcium reaction ratio of waste concrete. For the integral reactor conditions with packed bed of waste concrete, almost all HFC-134a in the feed gas could be decomposed until 20 min of the reaction time. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201727j
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11808-11814[article] Simultaneous decomposition and fixation of F - gases using waste concrete [texte imprimé] / Atsushi Iizuka, Auteur ; Hiroaki Ishizaki, Auteur ; Atsushi Mizukoshi, Auteur . - 2011 . - pp. 11808-11814.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11808-11814
Mots-clés : Fixation gases Waste concrete Résumé : Experimental study was conducted on the simultaneous process of decomposition and fixation of fluoride of F-gases. HFC-134a, a hydrofluorocarbon (HFC), used most widely, was selected as a model gas, and its decomposition performances were examined in a tube type reactor with and without waste concrete powder. Decomposition of HFC-134a was observed at temperatures above 500 °C, while no thermal decomposition occurred below 750 °C without waste concrete. The results for the differential type reactor with high SV demonstrated that the calcium reaction ratio in the waste concrete reached about 50 mol % after 10 min of reaction. Thermal decomposition of HFC-134a was promoted by increasing the reaction temperature. The particle size of the waste concrete within the range studied scarcely affected the decomposition rate. An increase in HFC-134a concentration resulted in a higher calcium reaction ratio of waste concrete. For the integral reactor conditions with packed bed of waste concrete, almost all HFC-134a in the feed gas could be decomposed until 20 min of the reaction time. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201727j Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Catalytic air gasification of plastic waste (Polypropylene) in a fluidized bed. Part II : effects of some operating variables on the quality of the raw gas produced using olivine as the in - bed material Type de document : texte imprimé Auteurs : José M. Toledo, Auteur ; María P. Aznar, Auteur ; Jesús A. Sancho, Auteur Année de publication : 2011 Article en page(s) : pp. 11815-11821 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Fluidized bed Fluidization Plastic waste Gasification Catalytic reaction Résumé : This work focuses on the gasification of 100 wt % plastic waste (polypropylene). Some operating variables that were studied included the amount of olivine in the gasifier bed, the equivalence ratio, and the freeboard temperature. In a first series of tests, the effect of the amount of olivine in the bed on the gas composition was studied. Using 100 wt % olivine in the gasifier bed provided good results regarding tar content, ~2 g of tar/mN3; lower heating value (LHV), ~6 MJ/mN3; and gas yield, ~5.5 mN,drybasis3/kgdaf. In a second series of tests, the equivalence ratio and freeboard temperature were varied to obtain better results. The tar content in this second series of tests was about 2 g of tar/mN3, the LHV was about 9 MJ/mN3, and the gas yield was about 3.5 mN,drybasis3/kgdaf . DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697497
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11815-11821[article] Catalytic air gasification of plastic waste (Polypropylene) in a fluidized bed. Part II : effects of some operating variables on the quality of the raw gas produced using olivine as the in - bed material [texte imprimé] / José M. Toledo, Auteur ; María P. Aznar, Auteur ; Jesús A. Sancho, Auteur . - 2011 . - pp. 11815-11821.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11815-11821
Mots-clés : Fluidized bed Fluidization Plastic waste Gasification Catalytic reaction Résumé : This work focuses on the gasification of 100 wt % plastic waste (polypropylene). Some operating variables that were studied included the amount of olivine in the gasifier bed, the equivalence ratio, and the freeboard temperature. In a first series of tests, the effect of the amount of olivine in the bed on the gas composition was studied. Using 100 wt % olivine in the gasifier bed provided good results regarding tar content, ~2 g of tar/mN3; lower heating value (LHV), ~6 MJ/mN3; and gas yield, ~5.5 mN,drybasis3/kgdaf. In a second series of tests, the equivalence ratio and freeboard temperature were varied to obtain better results. The tar content in this second series of tests was about 2 g of tar/mN3, the LHV was about 9 MJ/mN3, and the gas yield was about 3.5 mN,drybasis3/kgdaf . DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697497 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Modeling of toluene acetylation with acetic anhydride on H-USY zeolite Type de document : texte imprimé Auteurs : Eileen A. Dejaegere, Auteur ; Joris W. Thybaut, Auteur ; Guy B. Marin, Auteur Année de publication : 2011 Article en page(s) : pp. 11822-11832 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Zeolite Acetylation Modeling Résumé : The liquid-phase acetylation of toluene with acetic anhydride was carried out in a continuous-flow reactor over H-USY zeolites with different Si/Al ratios at 180 °C, at different contact times and feed compositions. H-USY is an active catalyst for this reaction because the main reaction products at all times on stream are the desired methylacetophenone (MAP) and its reaction byproduct acetic acid Within the different MAP isomers, the selectivity toward 4-MAP equals 85%. Although the initial acetic anhydride conversion is 100%, the zeolite is subject to deactivation. Small amounts of side products such as methylbenzoic acid and isopropenyltoluene were also identified and their formation explained. The data and insights obtained during these experiments were used to obtain models describing the formation of MAP and the other components present in the reactor effluent. The most plausible model, obtained via model discrimination, was validated at different reaction conditions and takes into account adsorption of the chemical compounds, the catalytic reactions, and deactivation of the catalyst. It also includes hydrolysis of acetic anhydride and the formation of side products originating from MAP. According to this model, catalyst deactivation starts from MAP and acetic anhydride, whereby acetic acid is liberated. Fitting of the model to the experimental data shows that the kinetic constant for the formation of 4-MAP is comparable to that of the deactivation reaction. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697498
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11822-11832[article] Modeling of toluene acetylation with acetic anhydride on H-USY zeolite [texte imprimé] / Eileen A. Dejaegere, Auteur ; Joris W. Thybaut, Auteur ; Guy B. Marin, Auteur . - 2011 . - pp. 11822-11832.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11822-11832
Mots-clés : Zeolite Acetylation Modeling Résumé : The liquid-phase acetylation of toluene with acetic anhydride was carried out in a continuous-flow reactor over H-USY zeolites with different Si/Al ratios at 180 °C, at different contact times and feed compositions. H-USY is an active catalyst for this reaction because the main reaction products at all times on stream are the desired methylacetophenone (MAP) and its reaction byproduct acetic acid Within the different MAP isomers, the selectivity toward 4-MAP equals 85%. Although the initial acetic anhydride conversion is 100%, the zeolite is subject to deactivation. Small amounts of side products such as methylbenzoic acid and isopropenyltoluene were also identified and their formation explained. The data and insights obtained during these experiments were used to obtain models describing the formation of MAP and the other components present in the reactor effluent. The most plausible model, obtained via model discrimination, was validated at different reaction conditions and takes into account adsorption of the chemical compounds, the catalytic reactions, and deactivation of the catalyst. It also includes hydrolysis of acetic anhydride and the formation of side products originating from MAP. According to this model, catalyst deactivation starts from MAP and acetic anhydride, whereby acetic acid is liberated. Fitting of the model to the experimental data shows that the kinetic constant for the formation of 4-MAP is comparable to that of the deactivation reaction. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697498 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Investigation of the dissolution of colemanite ore in water and boric acid solutions including highly acidic ion exchangers under microwave heating Type de document : texte imprimé Auteurs : Cigdem Eymir Tekin, Auteur ; Huseyin Okur, Auteur Année de publication : 2011 Article en page(s) : pp. 11833-11842 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Microwave heating Ion exchanger Dissolution Résumé : The dissolution of colemanite obtained from Bandirma Boraks Corporation was investigated in boric acid solutions containing highly acidic ion exchangers in a classical and microwave energy heating environment and the results showed that superior conversions can be obtained via microwave heating. Particle size, acid concentration, reaction temperature, stirring speed, amount of ion exchanger, solid to liquid ratio, and microwave power were selected as parameters. Dissolution kinetics of colemanite was also examined and it was observed that the dissolution rate increased with decreasing particle size and solid to liquid ratio and increased with stirring speed, acid concentration, and amount of acidic ion exchanger. The relationship between conversion and system parameters was determined with nonlinear estimation by using the statistical program Statistica 7.0. The activation energies (E) for classical and microwave heating methods were found as 24.40 and 22.98 kJmol-1, respectively. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697499
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11833-11842[article] Investigation of the dissolution of colemanite ore in water and boric acid solutions including highly acidic ion exchangers under microwave heating [texte imprimé] / Cigdem Eymir Tekin, Auteur ; Huseyin Okur, Auteur . - 2011 . - pp. 11833-11842.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11833-11842
Mots-clés : Microwave heating Ion exchanger Dissolution Résumé : The dissolution of colemanite obtained from Bandirma Boraks Corporation was investigated in boric acid solutions containing highly acidic ion exchangers in a classical and microwave energy heating environment and the results showed that superior conversions can be obtained via microwave heating. Particle size, acid concentration, reaction temperature, stirring speed, amount of ion exchanger, solid to liquid ratio, and microwave power were selected as parameters. Dissolution kinetics of colemanite was also examined and it was observed that the dissolution rate increased with decreasing particle size and solid to liquid ratio and increased with stirring speed, acid concentration, and amount of acidic ion exchanger. The relationship between conversion and system parameters was determined with nonlinear estimation by using the statistical program Statistica 7.0. The activation energies (E) for classical and microwave heating methods were found as 24.40 and 22.98 kJmol-1, respectively. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697499 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Determination of liquid multiscale circulation structure in a bubble column by tracing the liquid flowing trajectory Type de document : texte imprimé Auteurs : Zi-Bin Huang, Auteur ; Zhen-Min Cheng, Auteur Année de publication : 2011 Article en page(s) : pp. 11843-11852 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Bubble column Résumé : To identify the liquid circulation flow structure in a bubble column, a set of multipoint tracer injection and detection device was developed for a systematic study in a bubble column of 550 cm in height and 50 cm in diameter. Tracer response profiles were measured to track the liquid flowing trajectory under various flow conditions in the column with and without draft tubes. They showed that only when the draft tube length was greater than 3 m could the tracer response exhibit obvious periodicity. To resolve the liquid circulation flow structure in the time and frequency domain, wavelet multiresolution analysis was adopted. The results showed that the liquid circulation frequency increased with superficial gas velocity, which is in agreement with the published literature. It was also found that the macroscale, mesoscale, and microscale circulation loops coexisted in the bubble column. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697500
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11843-11852[article] Determination of liquid multiscale circulation structure in a bubble column by tracing the liquid flowing trajectory [texte imprimé] / Zi-Bin Huang, Auteur ; Zhen-Min Cheng, Auteur . - 2011 . - pp. 11843-11852.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11843-11852
Mots-clés : Bubble column Résumé : To identify the liquid circulation flow structure in a bubble column, a set of multipoint tracer injection and detection device was developed for a systematic study in a bubble column of 550 cm in height and 50 cm in diameter. Tracer response profiles were measured to track the liquid flowing trajectory under various flow conditions in the column with and without draft tubes. They showed that only when the draft tube length was greater than 3 m could the tracer response exhibit obvious periodicity. To resolve the liquid circulation flow structure in the time and frequency domain, wavelet multiresolution analysis was adopted. The results showed that the liquid circulation frequency increased with superficial gas velocity, which is in agreement with the published literature. It was also found that the macroscale, mesoscale, and microscale circulation loops coexisted in the bubble column. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697500 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Controllable preparation of poly(butyl acrylate) by suspension polymerization in a coaxial capillary microreactor Type de document : texte imprimé Auteurs : Zhendong Liu, Auteur ; Yangcheng Lu, Auteur ; Bodong Yang, Auteur Année de publication : 2011 Article en page(s) : pp. 11853–11862 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Microreactor Résumé : In this work, a new controllable and continuous free radical polymerization process was developed and characterized in a coaxial capillary microreactor. In this process, the monomer solution was first dispersed into monodispersed droplets followed by thermal-initiated polymerization in the following capillary immersed in an oil bath. Poly(butyl acrylate) prepared in this microreactor possessed a much higher average molecular weight (Mn) and far lower polydispersity index (PDI) than that produced in a typical stirred vessel. The microreactor method possesses two unique advantages which allow for the optimization of the free radical polymerization process. First, the use of highly monodispersed droplets as polymerization units ensures that the polymerization process occurs uniformly in each individual droplet. Second, the small droplet size, on the order of several hundred micrometers, greatly enhances heat transfer efficiency with no heat accumulation within the droplets during polymerization. A simplified numerical simulation was used to show the superiority of the microreactor in effectively removing polymerization heat due to the miniaturization of the droplets to submillimeter scale. Simulation results also demonstrated that, in contrast to polymerization processes occurring in macroreactors, the polymerization conducted in the microreactor proceeded in a nearly isothermal condition. Experimental results in the microreactor showed that the molecular weight distribution was mainly determined by the size of the droplet, while the molecular weight of the polymer could be adjusted by changing the reaction temperature and 2,2-azobis(isobutyronitrile) concentration. This type of microreactor can potentially be applied to research involving the mechanisms of highly exothermic free radical polymerization processes and can also be used as an efficient tool for their controllable preparation. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201497b
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11853–11862[article] Controllable preparation of poly(butyl acrylate) by suspension polymerization in a coaxial capillary microreactor [texte imprimé] / Zhendong Liu, Auteur ; Yangcheng Lu, Auteur ; Bodong Yang, Auteur . - 2011 . - pp. 11853–11862.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11853–11862
Mots-clés : Microreactor Résumé : In this work, a new controllable and continuous free radical polymerization process was developed and characterized in a coaxial capillary microreactor. In this process, the monomer solution was first dispersed into monodispersed droplets followed by thermal-initiated polymerization in the following capillary immersed in an oil bath. Poly(butyl acrylate) prepared in this microreactor possessed a much higher average molecular weight (Mn) and far lower polydispersity index (PDI) than that produced in a typical stirred vessel. The microreactor method possesses two unique advantages which allow for the optimization of the free radical polymerization process. First, the use of highly monodispersed droplets as polymerization units ensures that the polymerization process occurs uniformly in each individual droplet. Second, the small droplet size, on the order of several hundred micrometers, greatly enhances heat transfer efficiency with no heat accumulation within the droplets during polymerization. A simplified numerical simulation was used to show the superiority of the microreactor in effectively removing polymerization heat due to the miniaturization of the droplets to submillimeter scale. Simulation results also demonstrated that, in contrast to polymerization processes occurring in macroreactors, the polymerization conducted in the microreactor proceeded in a nearly isothermal condition. Experimental results in the microreactor showed that the molecular weight distribution was mainly determined by the size of the droplet, while the molecular weight of the polymer could be adjusted by changing the reaction temperature and 2,2-azobis(isobutyronitrile) concentration. This type of microreactor can potentially be applied to research involving the mechanisms of highly exothermic free radical polymerization processes and can also be used as an efficient tool for their controllable preparation. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201497b Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Ammonia storage and slip in a urea selective catalytic reduction catalyst under steady and transient conditions Type de document : texte imprimé Auteurs : Yanguang Zhao, Auteur ; Jing Hu, Auteur ; Lun Hua, Auteur Année de publication : 2011 Article en page(s) : pp. 11863–11871 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Ammonia storage slip Résumé : This paper aims to investigate quantitatively the characteristics of the storage and slip of ammonia in a full-size vanadium-based selective catalytic reduction (SCR) catalyst under typical steady and transient conditions on a diesel engine test bench. The effect of space velocity (SV) and exhaust temperature on the ammonia storage process and the storage capacity of the catalyst was studied. The ammonia slip in various transient processes was also investigated. The experimental results indicate that the increase of SV causes early appearance of ammonia slip. Then, the ammonia storage time is shorten to avoid the ammonia slip and the ammonia storage amount is consequently reduced which has an effect on the NOx conversion efficiency. The exhaust temperature is the key factor affecting the ammonia storage capacity of the catalyst which sharply decreases with the increase of temperature. The NOx conversion efficiency strongly depends on the amount of ammonia storage when the temperature is lower than 280 °C, and it is nearly linear to the amount of ammonia storage at 200 °C. If the ammonia storage is not controlled properly ammonia slip will occur under various transient conditions. Rapid heating of the catalyst at low temperature can cause serious ammonia slip. The initial temperature of the heating process is crucial to causing ammonia slip in transient processes while SV is not the key factor. The saturation level of the ammonia storage has a significant effect on ammonia slip in transient processes. There is an appropriate amount of ammonia storage which can be defined as the “slip-preventing limit” that maximizes the NOx conversion efficiency while keeping ammonia slip under 10 ppm to comply with the Euro 6 legislation for heavy-duty diesel engines. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201045w
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11863–11871[article] Ammonia storage and slip in a urea selective catalytic reduction catalyst under steady and transient conditions [texte imprimé] / Yanguang Zhao, Auteur ; Jing Hu, Auteur ; Lun Hua, Auteur . - 2011 . - pp. 11863–11871.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11863–11871
Mots-clés : Ammonia storage slip Résumé : This paper aims to investigate quantitatively the characteristics of the storage and slip of ammonia in a full-size vanadium-based selective catalytic reduction (SCR) catalyst under typical steady and transient conditions on a diesel engine test bench. The effect of space velocity (SV) and exhaust temperature on the ammonia storage process and the storage capacity of the catalyst was studied. The ammonia slip in various transient processes was also investigated. The experimental results indicate that the increase of SV causes early appearance of ammonia slip. Then, the ammonia storage time is shorten to avoid the ammonia slip and the ammonia storage amount is consequently reduced which has an effect on the NOx conversion efficiency. The exhaust temperature is the key factor affecting the ammonia storage capacity of the catalyst which sharply decreases with the increase of temperature. The NOx conversion efficiency strongly depends on the amount of ammonia storage when the temperature is lower than 280 °C, and it is nearly linear to the amount of ammonia storage at 200 °C. If the ammonia storage is not controlled properly ammonia slip will occur under various transient conditions. Rapid heating of the catalyst at low temperature can cause serious ammonia slip. The initial temperature of the heating process is crucial to causing ammonia slip in transient processes while SV is not the key factor. The saturation level of the ammonia storage has a significant effect on ammonia slip in transient processes. There is an appropriate amount of ammonia storage which can be defined as the “slip-preventing limit” that maximizes the NOx conversion efficiency while keeping ammonia slip under 10 ppm to comply with the Euro 6 legislation for heavy-duty diesel engines. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201045w Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Methanol to gasoline - range hydrocarbons : influence of nanocrystal size and mesoporosity on catalytic performance and product distribution of ZSM - 5 Type de document : texte imprimé Auteurs : Ali A. Rownaghi, Auteur ; Jonas Hedlund, Auteur Année de publication : 2011 Article en page(s) : pp. 11872-11878 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Catalytic reaction Nanocrystal Résumé : Improvement of synthesis methods for ZSM-5 zeolite, as a heteregeneous catalyst, is essential for a wide variety of different reactions in the chemical industry. Decreasing zeolite crystal size and introducing mesoporosity into the zeolite structure can improve its performance in catalytic reaction through decreasing the micropore diffusion path-length and increasing the external surface area. In this study, three different ZSM-5 zeolites (Nano-ZSM-5, Meso-ZSM-5, and Con-ZSM-5) were prepared by a single-templating procedure, and the reaction of methanol to gasoline-range hydrocarbons was evaluated over synthesized ZSM-5 crystals in a fixed-bed continuous flow reactor. Good correlation was observed between catalytic performance, product distribution, mesoporosity, and crystal size of ZSM-5 zeolites. Both nanocrystal and mesoporous ZSM-5 zeolites showed long-term catalytic stability compared with the conventional one. In contrast to conventional ZSM-5 catalyst, the nanocrystal and mesoporous ZSM-5 catalysts showed high selectivities for light olefins and alkyl aromatics, respectively, in the conversion of methanol to gasoline. These results clearly indicate that both crystal size and mesoporosity significantly influence the ZSM-5 lifetime and product distribution. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697503
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11872-11878[article] Methanol to gasoline - range hydrocarbons : influence of nanocrystal size and mesoporosity on catalytic performance and product distribution of ZSM - 5 [texte imprimé] / Ali A. Rownaghi, Auteur ; Jonas Hedlund, Auteur . - 2011 . - pp. 11872-11878.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11872-11878
Mots-clés : Catalytic reaction Nanocrystal Résumé : Improvement of synthesis methods for ZSM-5 zeolite, as a heteregeneous catalyst, is essential for a wide variety of different reactions in the chemical industry. Decreasing zeolite crystal size and introducing mesoporosity into the zeolite structure can improve its performance in catalytic reaction through decreasing the micropore diffusion path-length and increasing the external surface area. In this study, three different ZSM-5 zeolites (Nano-ZSM-5, Meso-ZSM-5, and Con-ZSM-5) were prepared by a single-templating procedure, and the reaction of methanol to gasoline-range hydrocarbons was evaluated over synthesized ZSM-5 crystals in a fixed-bed continuous flow reactor. Good correlation was observed between catalytic performance, product distribution, mesoporosity, and crystal size of ZSM-5 zeolites. Both nanocrystal and mesoporous ZSM-5 zeolites showed long-term catalytic stability compared with the conventional one. In contrast to conventional ZSM-5 catalyst, the nanocrystal and mesoporous ZSM-5 catalysts showed high selectivities for light olefins and alkyl aromatics, respectively, in the conversion of methanol to gasoline. These results clearly indicate that both crystal size and mesoporosity significantly influence the ZSM-5 lifetime and product distribution. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697503 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Computational fluid dynamics simulation of a three - dimensional catalytic layer for decane oxidation : case study of reaction on particle surface Type de document : texte imprimé Auteurs : Alessio Caravella, Auteur ; Shigeki Hara, Auteur ; Nobuo Hara, Auteur Année de publication : 2011 Article en page(s) : pp. 11879–11888 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Fluid dynamics Decane oxidation Résumé : Computational fluid dynamics (CFD) simulations of a reactive catalytic layer of micrometer-sized particles with a submicrometer interparticle distance for decane oxidation are described. The investigation used two main approaches. The heterogeneous approach simulates particles at the reactive particle surface, by use of a monodispersed face-centered cubic structure of eight unit cells in series. In contrast, the pseudohomogeneous approach investigates the particle system as a homogeneous system (approximation) having dimensions and geometrical properties (tortuosity and porosity) identical to those of the heterogeneous one. Heterogeneous system results show that mass transfer resistance can be regarded as negligible in the whole range of parameters investigated (temperature and interparticle distance). Particularly, the difference in results obtained by the two approaches is negligible up to the highest temperature considered (400 °C), with a maximum discrepancy of about 2.4%. An analogous result is found through study of the effect of interparticle distance, which indicates that, under the conditions investigated, the pseudohomogeneous approach can be used effectively to simulate particle systems with micrometer-order length and submicrometer interparticle distance. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201225r
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11879–11888[article] Computational fluid dynamics simulation of a three - dimensional catalytic layer for decane oxidation : case study of reaction on particle surface [texte imprimé] / Alessio Caravella, Auteur ; Shigeki Hara, Auteur ; Nobuo Hara, Auteur . - 2011 . - pp. 11879–11888.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11879–11888
Mots-clés : Fluid dynamics Decane oxidation Résumé : Computational fluid dynamics (CFD) simulations of a reactive catalytic layer of micrometer-sized particles with a submicrometer interparticle distance for decane oxidation are described. The investigation used two main approaches. The heterogeneous approach simulates particles at the reactive particle surface, by use of a monodispersed face-centered cubic structure of eight unit cells in series. In contrast, the pseudohomogeneous approach investigates the particle system as a homogeneous system (approximation) having dimensions and geometrical properties (tortuosity and porosity) identical to those of the heterogeneous one. Heterogeneous system results show that mass transfer resistance can be regarded as negligible in the whole range of parameters investigated (temperature and interparticle distance). Particularly, the difference in results obtained by the two approaches is negligible up to the highest temperature considered (400 °C), with a maximum discrepancy of about 2.4%. An analogous result is found through study of the effect of interparticle distance, which indicates that, under the conditions investigated, the pseudohomogeneous approach can be used effectively to simulate particle systems with micrometer-order length and submicrometer interparticle distance. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201225r Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Temperature induced emulsification and demulsification of pseudoternary mixtures of tween80 – butanol – kerosene – water system Type de document : texte imprimé Auteurs : Partha Mukherjee, Auteur ; Sandhyamayee Sahu, Auteur ; Susanta Kumar Padhan, Auteur Année de publication : 2011 Article en page(s) : pp. 11889-11896 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Demulsification Emulsification Résumé : The phase diagrams of pseudoternary mixtures of Tween80-butanol-kerosene-water system were constructed by visual titration. The major three domains, i.e., oil in water, bicontinuous, and water in oil microemulsions were demarcated through conductivity measurement. A sharp increase in specific conductance in increasing water content in the bicontinuous domain has been ascribed to the percolation of ions through water continuum. Temperature induced clouding behavior of the mixtures in the Winsor IV domains was investigated to find out the effect of composition on the clouding temperature. A generalized regression model was proposed considering the cloud point to be a function of surfactant/cosurfactant ratio and oil and emulsifier contents. The increase in all these parameters increases the cloud points of the mixture. In the turbid Winsor III domain, temperature has an emulsifying effect. With increase in temperature, the turbid phase separates to three different phases, which experience transparent, translucent, and turbid characteristics due to mass transfer from one phase to another. The mass transfer phenomenon was well visualized by using nickel as water-soluble and N-alkyl 4-(p-N,N-dimethylaminostyryl)pyridinium dyes as oil-soluble probes. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697505
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11889-11896[article] Temperature induced emulsification and demulsification of pseudoternary mixtures of tween80 – butanol – kerosene – water system [texte imprimé] / Partha Mukherjee, Auteur ; Sandhyamayee Sahu, Auteur ; Susanta Kumar Padhan, Auteur . - 2011 . - pp. 11889-11896.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11889-11896
Mots-clés : Demulsification Emulsification Résumé : The phase diagrams of pseudoternary mixtures of Tween80-butanol-kerosene-water system were constructed by visual titration. The major three domains, i.e., oil in water, bicontinuous, and water in oil microemulsions were demarcated through conductivity measurement. A sharp increase in specific conductance in increasing water content in the bicontinuous domain has been ascribed to the percolation of ions through water continuum. Temperature induced clouding behavior of the mixtures in the Winsor IV domains was investigated to find out the effect of composition on the clouding temperature. A generalized regression model was proposed considering the cloud point to be a function of surfactant/cosurfactant ratio and oil and emulsifier contents. The increase in all these parameters increases the cloud points of the mixture. In the turbid Winsor III domain, temperature has an emulsifying effect. With increase in temperature, the turbid phase separates to three different phases, which experience transparent, translucent, and turbid characteristics due to mass transfer from one phase to another. The mass transfer phenomenon was well visualized by using nickel as water-soluble and N-alkyl 4-(p-N,N-dimethylaminostyryl)pyridinium dyes as oil-soluble probes. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697505 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Hybrid intumescent coatings for wood protection against fire action Type de document : texte imprimé Auteurs : Guadalupe Canosa, Auteur ; Paula V. Alfieri, Auteur ; Carlos A. Giudice, Auteur Année de publication : 2011 Article en page(s) : pp. 11897-11905 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Hybrid coatings Résumé : Hybrid intumescent coatings for wood protection against fire were developed. Several resins were chosen as film-forming materials. Similar active and complementary pigments were used. To improve the efficiency, coatings were formulated by using reinforcing fibers. The performance of hybrid coatings was determined on panels of Araucaria angustifolia; some coatings showed an excellent performance in thermal conductivity test, two-foot tunnel, OI cabin, UL 94 horizontal–vertical chamber, and TGA trials. The best performance was achieved with chlorinated rubber, followed by phenolic resin, and finally by epoxy resin. With respect to fibers, hybrid formulations had a superior performance in relation to the respective reference samples; in addition, coatings displayed the best behavior with alumina, carbon, aramid, and glass fibers in their composition, in that order. An elevated synergistic effect was observed; the mentioned synergistic effect could be based on that the nature of the interface in a composite would affect its combustibility. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200015k
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11897-11905[article] Hybrid intumescent coatings for wood protection against fire action [texte imprimé] / Guadalupe Canosa, Auteur ; Paula V. Alfieri, Auteur ; Carlos A. Giudice, Auteur . - 2011 . - pp. 11897-11905.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11897-11905
Mots-clés : Hybrid coatings Résumé : Hybrid intumescent coatings for wood protection against fire were developed. Several resins were chosen as film-forming materials. Similar active and complementary pigments were used. To improve the efficiency, coatings were formulated by using reinforcing fibers. The performance of hybrid coatings was determined on panels of Araucaria angustifolia; some coatings showed an excellent performance in thermal conductivity test, two-foot tunnel, OI cabin, UL 94 horizontal–vertical chamber, and TGA trials. The best performance was achieved with chlorinated rubber, followed by phenolic resin, and finally by epoxy resin. With respect to fibers, hybrid formulations had a superior performance in relation to the respective reference samples; in addition, coatings displayed the best behavior with alumina, carbon, aramid, and glass fibers in their composition, in that order. An elevated synergistic effect was observed; the mentioned synergistic effect could be based on that the nature of the interface in a composite would affect its combustibility. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200015k Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Tough thermoplastic starch modified with polyurethane microparticles : the effects of NCO content in prepolymers Type de document : texte imprimé Auteurs : Yu Zhang, Auteur ; Yan Huang, Auteur ; Xiaoxia Chen, Auteur Année de publication : 2011 Article en page(s) : pp. 11906-11911 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Microparticle Résumé : In this work, polyurethane prepolymers (PUPs) with various NCO content proportions were synthesized and mixed reactively with a starch-water mixture to prepare modified thermoplastic starch (TPS) in an environmentally friendly way. The effects of polyurethane NCO content on the structure and/or properties of the modified TPS sheets were investigated. Results revealed that the reaction ratio of PUPs used for preparing the modified TPS was 99.8%, indicating that the PUPs were almost cross-linked to the starch matrix. With an increase of NCO content in PUP, the tensile strength of the modified TPS increased from 19.3 to 37.4 MPa, and the elongation from 1.7% to 17.2%. As the PUP's NCO content increased, the amount of urethane linkage between PU microparticles and the starch matrix would increase. In addition, the compatibility of the two polymers was also improved resulting in the improvement of tensile properties. The urethane linkage between PU and starch therefore played an important role in improving the toughness of the modified TPS. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697507
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11906-11911[article] Tough thermoplastic starch modified with polyurethane microparticles : the effects of NCO content in prepolymers [texte imprimé] / Yu Zhang, Auteur ; Yan Huang, Auteur ; Xiaoxia Chen, Auteur . - 2011 . - pp. 11906-11911.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11906-11911
Mots-clés : Microparticle Résumé : In this work, polyurethane prepolymers (PUPs) with various NCO content proportions were synthesized and mixed reactively with a starch-water mixture to prepare modified thermoplastic starch (TPS) in an environmentally friendly way. The effects of polyurethane NCO content on the structure and/or properties of the modified TPS sheets were investigated. Results revealed that the reaction ratio of PUPs used for preparing the modified TPS was 99.8%, indicating that the PUPs were almost cross-linked to the starch matrix. With an increase of NCO content in PUP, the tensile strength of the modified TPS increased from 19.3 to 37.4 MPa, and the elongation from 1.7% to 17.2%. As the PUP's NCO content increased, the amount of urethane linkage between PU microparticles and the starch matrix would increase. In addition, the compatibility of the two polymers was also improved resulting in the improvement of tensile properties. The urethane linkage between PU and starch therefore played an important role in improving the toughness of the modified TPS. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697507 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Preparation of hydrolyzed electrospun polyacrylonitrile fiber mats as chelating substrates : a case study on copper(II) ions Type de document : texte imprimé Auteurs : Pimolpun Kampalanonwat, Auteur ; Pitt Supaphol, Auteur Année de publication : 2011 Article en page(s) : pp. 11912-11921 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Hydrolyzed Electrospun Copper Ions Résumé : Ultrafine polyacrylonitrile (PAN) fiber mats were prepared by electrospinning and subsequently hydrolytically treated with a sodium hydroxide ethanolic/aqueous solution to impart the ability to chelate metal ions. This was achieved through the conversion of the nitrile functional groups on the surface of the PAN fibers into imine conjugated sequences, which was confirmed by Fourier-transform infrared spectroscopy. The chelating property of the hydrolyzed electrospun PAN fiber mats (i.e., H-ePAN fiber mats) was evaluated against Cu(U) ions. The amounts ofthe Cu(II) ions adsorbed onto the H-ePAN fiber mats were influenced by the initial pH and the initial concentration of the metal ion solutions. At the optimal pH of 5.0, the amounts of the Cu(II) ions adsorbed onto the H-ePAN fiber mats increased with an initial increase in the time the materials were in contact with the metal ion solution to finally reach the maximal, plateau values after about 5 h of immersion. The maximal adsorption capacity of the H-ePAN fiber mats for the Cu(II) ions was determined to be 31.3 mg g-1, and the fully adsorbed materials could be regenerated upon submersion in 0.1 M hydrochloric acid aqueous solution for 30 min. Finally, X-ray photoelectron spectroscopy indicated specific interactions between the adsorbed Cu(II) ions and the N- and/or the O-atoms associated with the imine groups on the. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200504c
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11912-11921[article] Preparation of hydrolyzed electrospun polyacrylonitrile fiber mats as chelating substrates : a case study on copper(II) ions [texte imprimé] / Pimolpun Kampalanonwat, Auteur ; Pitt Supaphol, Auteur . - 2011 . - pp. 11912-11921.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11912-11921
Mots-clés : Hydrolyzed Electrospun Copper Ions Résumé : Ultrafine polyacrylonitrile (PAN) fiber mats were prepared by electrospinning and subsequently hydrolytically treated with a sodium hydroxide ethanolic/aqueous solution to impart the ability to chelate metal ions. This was achieved through the conversion of the nitrile functional groups on the surface of the PAN fibers into imine conjugated sequences, which was confirmed by Fourier-transform infrared spectroscopy. The chelating property of the hydrolyzed electrospun PAN fiber mats (i.e., H-ePAN fiber mats) was evaluated against Cu(U) ions. The amounts ofthe Cu(II) ions adsorbed onto the H-ePAN fiber mats were influenced by the initial pH and the initial concentration of the metal ion solutions. At the optimal pH of 5.0, the amounts of the Cu(II) ions adsorbed onto the H-ePAN fiber mats increased with an initial increase in the time the materials were in contact with the metal ion solution to finally reach the maximal, plateau values after about 5 h of immersion. The maximal adsorption capacity of the H-ePAN fiber mats for the Cu(II) ions was determined to be 31.3 mg g-1, and the fully adsorbed materials could be regenerated upon submersion in 0.1 M hydrochloric acid aqueous solution for 30 min. Finally, X-ray photoelectron spectroscopy indicated specific interactions between the adsorbed Cu(II) ions and the N- and/or the O-atoms associated with the imine groups on the. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200504c Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Effect of thickness of photocatalyst film immobilized on a buoyant substrate on the degradation of methyl orange dye in aqueous solutions under different light irradiations Type de document : texte imprimé Auteurs : Hui Han, Auteur ; Renbi Bai, Auteur Année de publication : 2011 Article en page(s) : pp. 11922-11929 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Aqueous solution Dyes Photocatalysis Catalyst Résumé : This study examined the effect of thickness of photocatalyst film immobilized on a buovant polypropylene (PP) substrate on the degradation of methyl orange (MO) dye in aqueous solutions using different light sources. The photocatalyst used was titanium dioxide (TiO2) and the immobilized photocatalyst film thickness varied in a range from 6.9 to 34.1 μm. Both degradation experiments and model fitting analysis for the experimental data were carried out. All the experimental results on MO dye degradation were found to be well fitted by a pseudo-first-order reaction kinetic model. However, the degradation performance and the reaction kinetic model rate constant showed a clear trend of increase with the increase of the photocatalyst film thickness under the visible (Vis) light irradiation, but had no obvious change with the photocatalyst film thickness under the ultraviolet (UV) light irradiation. This phenomenon was attributed to the much smaller active photocatalyst film thickness for the UV light (due to the lesser quantity of photons and hence less thickness through which the light penetrated), as compared to that for the Vis light in the photocatalytic reaction. The study reveals that methods effectively increasing the photocatalyst film thickness on the buoyant substrate in the preparation of the buoyant composite photocatalyst are beneficial for the photocatalytic degradation of MO dye, especially for situations when the system may work mainly with the visible light, such as using the natural sunlight as the light source. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697509
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11922-11929[article] Effect of thickness of photocatalyst film immobilized on a buoyant substrate on the degradation of methyl orange dye in aqueous solutions under different light irradiations [texte imprimé] / Hui Han, Auteur ; Renbi Bai, Auteur . - 2011 . - pp. 11922-11929.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11922-11929
Mots-clés : Aqueous solution Dyes Photocatalysis Catalyst Résumé : This study examined the effect of thickness of photocatalyst film immobilized on a buovant polypropylene (PP) substrate on the degradation of methyl orange (MO) dye in aqueous solutions using different light sources. The photocatalyst used was titanium dioxide (TiO2) and the immobilized photocatalyst film thickness varied in a range from 6.9 to 34.1 μm. Both degradation experiments and model fitting analysis for the experimental data were carried out. All the experimental results on MO dye degradation were found to be well fitted by a pseudo-first-order reaction kinetic model. However, the degradation performance and the reaction kinetic model rate constant showed a clear trend of increase with the increase of the photocatalyst film thickness under the visible (Vis) light irradiation, but had no obvious change with the photocatalyst film thickness under the ultraviolet (UV) light irradiation. This phenomenon was attributed to the much smaller active photocatalyst film thickness for the UV light (due to the lesser quantity of photons and hence less thickness through which the light penetrated), as compared to that for the Vis light in the photocatalytic reaction. The study reveals that methods effectively increasing the photocatalyst film thickness on the buoyant substrate in the preparation of the buoyant composite photocatalyst are beneficial for the photocatalytic degradation of MO dye, especially for situations when the system may work mainly with the visible light, such as using the natural sunlight as the light source. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697509 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Dispersibility and hydrophobicity analysis of titanium dioxide nanoparticles grafted with silane coupling agent Type de document : texte imprimé Auteurs : Chaoxia Wang, Auteur ; Haiyan Mao, Auteur ; Chunxia Wang, Auteur Année de publication : 2011 Article en page(s) : pp. 11930-11934 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Coupling agent Nanoparticle Hydrophobicity Résumé : The high surface energy of TiO2 nanoparticulate leads to the aggregation of nanoparticles. The grafted modification of nanoparticles is necessary in order to improve its dispersibility in the organic solvent. The effect of grafted modification with silane coupling agent on dispersibility and lipophilicity of TiO2 nanoparticles was investigated. The factors of the modification were discussed, such as the amount of silane coupling agent, pH value, and reaction time. The average sizes of the TiO2 nanoparticles were 200-300 nm. The thermogravimetric analysis (TGA) curves indicated that the TiO2 nanoparticle surface had been grafted with the silane coupling agent. The zeta potential showed that modified TiO2 could disperse well in the organic solvent. The lipophilic degree and contact angle suggested that the modified TiO2 had low surface energy and changed from a hydrophilic nature to a lipophilic nature. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697510
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11930-11934[article] Dispersibility and hydrophobicity analysis of titanium dioxide nanoparticles grafted with silane coupling agent [texte imprimé] / Chaoxia Wang, Auteur ; Haiyan Mao, Auteur ; Chunxia Wang, Auteur . - 2011 . - pp. 11930-11934.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11930-11934
Mots-clés : Coupling agent Nanoparticle Hydrophobicity Résumé : The high surface energy of TiO2 nanoparticulate leads to the aggregation of nanoparticles. The grafted modification of nanoparticles is necessary in order to improve its dispersibility in the organic solvent. The effect of grafted modification with silane coupling agent on dispersibility and lipophilicity of TiO2 nanoparticles was investigated. The factors of the modification were discussed, such as the amount of silane coupling agent, pH value, and reaction time. The average sizes of the TiO2 nanoparticles were 200-300 nm. The thermogravimetric analysis (TGA) curves indicated that the TiO2 nanoparticle surface had been grafted with the silane coupling agent. The zeta potential showed that modified TiO2 could disperse well in the organic solvent. The lipophilic degree and contact angle suggested that the modified TiO2 had low surface energy and changed from a hydrophilic nature to a lipophilic nature. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697510 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Electric relaxational effects induced by ionic conductivity in dielectric materials Type de document : texte imprimé Auteurs : Jolanta Swiergiel, Auteur ; Jan Jadzyn, Auteur Année de publication : 2011 Article en page(s) : pp. 11935-11941 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Dielectric materials Résumé : The paper shows how the direct current ionic conductivity (σDC) and the static dielectric permittivity (εs) reveal themselves in the complex impedance, the electric modulus, and the conductance of molecular liquids when the frequency of the electric stimulus is much lower than that corresponding to the dipolar reorientational relaxation of the liquid under investigation. It was shown that, in such static dielectric conditions, one observes the relaxational behavior of the impedance and the electric modulus, both ofthe Debye-type and ofthe same relaxation time, depending on σDC and εs values. The discussion is illustrated with the experimental electric spectra of liquid cyclobutanone recorded in the frequency region from 500 Hz to 5 MHz and in the temperature range from 243 to 313 K. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697511
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11935-11941[article] Electric relaxational effects induced by ionic conductivity in dielectric materials [texte imprimé] / Jolanta Swiergiel, Auteur ; Jan Jadzyn, Auteur . - 2011 . - pp. 11935-11941.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11935-11941
Mots-clés : Dielectric materials Résumé : The paper shows how the direct current ionic conductivity (σDC) and the static dielectric permittivity (εs) reveal themselves in the complex impedance, the electric modulus, and the conductance of molecular liquids when the frequency of the electric stimulus is much lower than that corresponding to the dipolar reorientational relaxation of the liquid under investigation. It was shown that, in such static dielectric conditions, one observes the relaxational behavior of the impedance and the electric modulus, both ofthe Debye-type and ofthe same relaxation time, depending on σDC and εs values. The discussion is illustrated with the experimental electric spectra of liquid cyclobutanone recorded in the frequency region from 500 Hz to 5 MHz and in the temperature range from 243 to 313 K. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697511 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Entrainer effect of N , N - dimethylformamide on solubility of monomers for aromatic polyimide in supercritical carbon dioxide Type de document : texte imprimé Auteurs : Masashi Haruki, Auteur ; Naoya Fukui, Auteur ; Fumiya Kobayashi, Auteur Année de publication : 2011 Article en page(s) : pp. 11942-11949 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Supercritical state Carbon dioxide Solubility Résumé : The solubilities of 4,4'-diaminodiphenyl ether (ODA) and pyromellitic dianhydride (PMDA) in supercritical carbon dioxide (scCO2) with N,N-dimethylformamide (DMF) were measured by a semibatch flow method, to accumulate new experimental data and to clarify the entrainer effect of DMF on the solubilities of the monomers of aromatic polyimide in scCO2. All measurements were carried out at 323 K and 20.0 MPa with DMF concentrations from 0 to about 20 mol %. The solubilities of both ODA and PMDA increased dramatically with increasing DMF concentration under our experimental conditions. For example, the addition of about 10 mol % of DMF increased the solubilities of ODA and PMDA to 54- and 115-fold, respectively, as compared to their solubilities in pure scCO2. The experimental results were correlated and predicted by the Peng-Robinson equation of state (PR-EOS). The critical temperatures and pressures of ODA and PMDA were estimated utilizing the group contribution method proposed by Constantinou and Gani, and the solid molar volumes of ODA and PMDA needed for calculation were obtained by the COSMO-RS method. The vapor pressures of ODA and PMDA, which are also required to calculate the solubilities, were obtained by correlating the solubilities of ODA and PMDA in pure CO2. The binary interaction parameters were estimated by correlating the phase equilibria and solubilities for each binary system. The predicted results approximately reproduced the experimental results for the solubilities of ODA in scCO2. As for the solubilities of PMDA, while a large deviation was observed between the predicted and experimental results, the correlated results approximately corresponded to the experimental data. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697512
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11942-11949[article] Entrainer effect of N , N - dimethylformamide on solubility of monomers for aromatic polyimide in supercritical carbon dioxide [texte imprimé] / Masashi Haruki, Auteur ; Naoya Fukui, Auteur ; Fumiya Kobayashi, Auteur . - 2011 . - pp. 11942-11949.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11942-11949
Mots-clés : Supercritical state Carbon dioxide Solubility Résumé : The solubilities of 4,4'-diaminodiphenyl ether (ODA) and pyromellitic dianhydride (PMDA) in supercritical carbon dioxide (scCO2) with N,N-dimethylformamide (DMF) were measured by a semibatch flow method, to accumulate new experimental data and to clarify the entrainer effect of DMF on the solubilities of the monomers of aromatic polyimide in scCO2. All measurements were carried out at 323 K and 20.0 MPa with DMF concentrations from 0 to about 20 mol %. The solubilities of both ODA and PMDA increased dramatically with increasing DMF concentration under our experimental conditions. For example, the addition of about 10 mol % of DMF increased the solubilities of ODA and PMDA to 54- and 115-fold, respectively, as compared to their solubilities in pure scCO2. The experimental results were correlated and predicted by the Peng-Robinson equation of state (PR-EOS). The critical temperatures and pressures of ODA and PMDA were estimated utilizing the group contribution method proposed by Constantinou and Gani, and the solid molar volumes of ODA and PMDA needed for calculation were obtained by the COSMO-RS method. The vapor pressures of ODA and PMDA, which are also required to calculate the solubilities, were obtained by correlating the solubilities of ODA and PMDA in pure CO2. The binary interaction parameters were estimated by correlating the phase equilibria and solubilities for each binary system. The predicted results approximately reproduced the experimental results for the solubilities of ODA in scCO2. As for the solubilities of PMDA, while a large deviation was observed between the predicted and experimental results, the correlated results approximately corresponded to the experimental data. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697512 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Enhancement of hematite flocculation in the hematite – starch – (Low - Molecular - Weight) poly (acrylic acid) system Type de document : texte imprimé Auteurs : Mark Ma, Auteur Année de publication : 2011 Article en page(s) : pp.11950–11953 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Flocculation Hematite Résumé : In the iron ore industry, the flocculation of hematite with starch in the presence of a dispersant for gangue minerals is important for the production of high-grade concentrates. The sequence of reagent addition in this process has been considered negligible as starch was reported to have no significant effect on the adsorption of other reagents in the literature. In this work, the colloid stability of hematite with different reagent addition sequences was studied. The results demonstrate that, when hematite is preconditioned with starch, the subsequent addition of a low-molecular-weight poly(acrylic acid) does not show any dispersive effect on hematite at starch concentrations greater than or equal to 4 ppm, because the adsorption of poly(acrylic acid) is completely blocked by the starch molecules coated on the hematite surfaces. When hematite is preconditioned with poly(acrylic acid) , the flocculation effect of the subsequently added starch is significantly affected, with strong steric stabilization observed because of the reduced number of adsorption sites available to starch molecules. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2013373
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp.11950–11953[article] Enhancement of hematite flocculation in the hematite – starch – (Low - Molecular - Weight) poly (acrylic acid) system [texte imprimé] / Mark Ma, Auteur . - 2011 . - pp.11950–11953.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp.11950–11953
Mots-clés : Flocculation Hematite Résumé : In the iron ore industry, the flocculation of hematite with starch in the presence of a dispersant for gangue minerals is important for the production of high-grade concentrates. The sequence of reagent addition in this process has been considered negligible as starch was reported to have no significant effect on the adsorption of other reagents in the literature. In this work, the colloid stability of hematite with different reagent addition sequences was studied. The results demonstrate that, when hematite is preconditioned with starch, the subsequent addition of a low-molecular-weight poly(acrylic acid) does not show any dispersive effect on hematite at starch concentrations greater than or equal to 4 ppm, because the adsorption of poly(acrylic acid) is completely blocked by the starch molecules coated on the hematite surfaces. When hematite is preconditioned with poly(acrylic acid) , the flocculation effect of the subsequently added starch is significantly affected, with strong steric stabilization observed because of the reduced number of adsorption sites available to starch molecules. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie2013373 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Inhibitive effect of argemone mexicana plant extract on acid corrosion of mild steel Type de document : texte imprimé Auteurs : Gopal ji, Auteur ; Sudhish Kumar Shukla, Auteur ; Priyanka Dwivedi, Auteur Année de publication : 2011 Article en page(s) : pp. 11954-11959 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Mild steel Acid corrosion Extract Résumé : The effect of plant extract of Papaveraceae family Argemone mexicana is studied for use as a low cost and efficient corrosion inhibitor for mild steel in acidic environment. This plant extract is selected for the study of corrosion inhibition in view of its rich source of organic inhibiting molecules as proteins, amino acids, tannins, phenolic compounds, saponins, and flavonoids and nonalkaloids organic compounds such as fused benzene rings, hetero N atom rings, -OCH3, and -OH groups. A simple extraction method is adopted to obtain water-based plant extract. Argemone mexicana extract is for the first time used as an efficient inhibitor for mild steel in 1 M HCL Weight loss and electrochemical methods are used to study the corrosion. Nearly 80% corrosion inhibition is observed at around 200 mg L-1 inhibitor concentration and maximum (92.5%) for 500 mg L-1 extract concentration in 1 M HCl. Inhibition mechanism is studied using UV-vis, electrochemical, and surface imaging techniques. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697514
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11954-11959[article] Inhibitive effect of argemone mexicana plant extract on acid corrosion of mild steel [texte imprimé] / Gopal ji, Auteur ; Sudhish Kumar Shukla, Auteur ; Priyanka Dwivedi, Auteur . - 2011 . - pp. 11954-11959.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11954-11959
Mots-clés : Mild steel Acid corrosion Extract Résumé : The effect of plant extract of Papaveraceae family Argemone mexicana is studied for use as a low cost and efficient corrosion inhibitor for mild steel in acidic environment. This plant extract is selected for the study of corrosion inhibition in view of its rich source of organic inhibiting molecules as proteins, amino acids, tannins, phenolic compounds, saponins, and flavonoids and nonalkaloids organic compounds such as fused benzene rings, hetero N atom rings, -OCH3, and -OH groups. A simple extraction method is adopted to obtain water-based plant extract. Argemone mexicana extract is for the first time used as an efficient inhibitor for mild steel in 1 M HCL Weight loss and electrochemical methods are used to study the corrosion. Nearly 80% corrosion inhibition is observed at around 200 mg L-1 inhibitor concentration and maximum (92.5%) for 500 mg L-1 extract concentration in 1 M HCl. Inhibition mechanism is studied using UV-vis, electrochemical, and surface imaging techniques. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697514 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Structural characterization and catalytic evaluation of supported copper – ceria catalysts for soot oxidation Type de document : texte imprimé Auteurs : Komateedi N. Rao, Auteur ; P. Venkataswamy, Auteur ; Benjaram M. Reddy, Auteur Année de publication : 2011 Article en page(s) : pp. 11960–11969 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Soot oxidation catalyst Résumé : The present investigation was undertaken with the aim of designing a noble-metal-free diesel soot oxidation catalyst that can work at relatively low temperatures. Accordingly, a series CeO2–Al2O3, CeO2–ZrO2, and CeO2–SiO2 mixed-oxide-supported copper catalysts were prepared by a modified deposition–precipitation method from ultradilute aqueous solutions and evaluated for soot oxidation at normal atmospheric pressure. The structural and electronic properties were investigated by various physicochemical techniques, namely, X-ray diffraction (XRD), Raman spectroscopy, temperature-programmed desorption (TPD), temperature-programmed reduction–oxidation (TPR–TPO), temperature-programmed mass spectroscopy (TP-MS), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Formation of a Ce1–xCuxO2 solid solution was inferred from XRD, TPR, and Raman spectroscopy studies. The TEM results revealed the presence of copper–ceria nano-oxides of 5–7-nm size in highly dispersed form. The TPR–TPO results suggested a profound influence of mixed-oxide supports on the reduction behavior of copper oxide. In particular, the TP-MS results provided direct evidence for labile oxygen generation. Among the investigated catalysts, the CuO/CeO2–ZrO2 combination exhibited excellent catalytic activity for soot oxidation, with T1/2 = 611 K. Incorporation of Cu2+ into the ceria–zirconia solid solution favored the creation of more structural defects, which accelerate the oxygen diffusion and induce more of the surface-active oxygen species that are responsible for the enhanced soot oxidation activity at lower temperatures. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201474p
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11960–11969[article] Structural characterization and catalytic evaluation of supported copper – ceria catalysts for soot oxidation [texte imprimé] / Komateedi N. Rao, Auteur ; P. Venkataswamy, Auteur ; Benjaram M. Reddy, Auteur . - 2011 . - pp. 11960–11969.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11960–11969
Mots-clés : Soot oxidation catalyst Résumé : The present investigation was undertaken with the aim of designing a noble-metal-free diesel soot oxidation catalyst that can work at relatively low temperatures. Accordingly, a series CeO2–Al2O3, CeO2–ZrO2, and CeO2–SiO2 mixed-oxide-supported copper catalysts were prepared by a modified deposition–precipitation method from ultradilute aqueous solutions and evaluated for soot oxidation at normal atmospheric pressure. The structural and electronic properties were investigated by various physicochemical techniques, namely, X-ray diffraction (XRD), Raman spectroscopy, temperature-programmed desorption (TPD), temperature-programmed reduction–oxidation (TPR–TPO), temperature-programmed mass spectroscopy (TP-MS), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). Formation of a Ce1–xCuxO2 solid solution was inferred from XRD, TPR, and Raman spectroscopy studies. The TEM results revealed the presence of copper–ceria nano-oxides of 5–7-nm size in highly dispersed form. The TPR–TPO results suggested a profound influence of mixed-oxide supports on the reduction behavior of copper oxide. In particular, the TP-MS results provided direct evidence for labile oxygen generation. Among the investigated catalysts, the CuO/CeO2–ZrO2 combination exhibited excellent catalytic activity for soot oxidation, with T1/2 = 611 K. Incorporation of Cu2+ into the ceria–zirconia solid solution favored the creation of more structural defects, which accelerate the oxygen diffusion and induce more of the surface-active oxygen species that are responsible for the enhanced soot oxidation activity at lower temperatures. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201474p Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Miscibility and crystallization behavior of biodegradable poly (butylene succinate) / tannic acid blends Type de document : texte imprimé Auteurs : Fang Yang, Auteur ; Zhaobin Qiu, Auteur Année de publication : 2011 Article en page(s) : pp. 11970-11974 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Crystallization Résumé : Miscibility, crystallization behavior, crystal structure, and microstructure of biodegradable poly(butylene succinate)/ tannic acid (PBSU/TA) blends were studied with differential scanning calorimetry, optical microscopy, wide-angle X-ray diffraction, and small-angle X-ray scattering in this work. PBSU and TA are miscible as evidenced by the single composition dependent glass transition temperature over the whole blend composition range and the depression of equilibrium melting point of PBSU in the blends. Nonisothermal melt crystallization of PBSU is retarded by the presence of TA. It is found that blending with TA affects the spherulitic morphology of PBSU apparently but does not modify the crystal structure of PBSU. The long period and thickness of the amorphous phase become larger with increasing the TA content in the blends, indicating that TA mainly resides in the interlamellar region of PBSU spherulites. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697516
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11970-11974[article] Miscibility and crystallization behavior of biodegradable poly (butylene succinate) / tannic acid blends [texte imprimé] / Fang Yang, Auteur ; Zhaobin Qiu, Auteur . - 2011 . - pp. 11970-11974.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11970-11974
Mots-clés : Crystallization Résumé : Miscibility, crystallization behavior, crystal structure, and microstructure of biodegradable poly(butylene succinate)/ tannic acid (PBSU/TA) blends were studied with differential scanning calorimetry, optical microscopy, wide-angle X-ray diffraction, and small-angle X-ray scattering in this work. PBSU and TA are miscible as evidenced by the single composition dependent glass transition temperature over the whole blend composition range and the depression of equilibrium melting point of PBSU in the blends. Nonisothermal melt crystallization of PBSU is retarded by the presence of TA. It is found that blending with TA affects the spherulitic morphology of PBSU apparently but does not modify the crystal structure of PBSU. The long period and thickness of the amorphous phase become larger with increasing the TA content in the blends, indicating that TA mainly resides in the interlamellar region of PBSU spherulites. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697516 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Development and characterization of fire retarded glass - fiber reinforced poly(1,4 - butylene terephthalate) composites based on a novel flame retardant system Type de document : texte imprimé Auteurs : Wei Yang, Auteur ; Richard K. K. Yuen, Auteur ; Yuan Hu, Auteur Année de publication : 2011 Article en page(s) : pp. 11975-11981 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Flame retardant Composite material Glass fiber Fires Résumé : The aim of this work was to develop halogen-free glass-fiber reinforced poly( 1,4-butylene terephthalate) (GRPBT) composites with significantly improved fire retardancy performance using a novel flame retardant system. The system was composed of aluminum hypophosphite (AHP), polycarbonate (PC), and melamine cyanurate (MC). The GRPBT composite containing the system achieved a V-0 classification in UL-94 testing (the thickness of testing bar was 0.8 mm). In microscale combustion calorimeter and cone calorimeter testing, both of the two different PHRRs (peak of heat release rate) for GRPBT composites were remarkably reduced by the incorporation ofthe novel system. Thermogravimetric analysis and residue characterization revealed that the addition of PC promoted the formation of char residues leading to the reduction of mass loss rate, which resulted in the improvement of fire retardancy. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697517
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11975-11981[article] Development and characterization of fire retarded glass - fiber reinforced poly(1,4 - butylene terephthalate) composites based on a novel flame retardant system [texte imprimé] / Wei Yang, Auteur ; Richard K. K. Yuen, Auteur ; Yuan Hu, Auteur . - 2011 . - pp. 11975-11981.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11975-11981
Mots-clés : Flame retardant Composite material Glass fiber Fires Résumé : The aim of this work was to develop halogen-free glass-fiber reinforced poly( 1,4-butylene terephthalate) (GRPBT) composites with significantly improved fire retardancy performance using a novel flame retardant system. The system was composed of aluminum hypophosphite (AHP), polycarbonate (PC), and melamine cyanurate (MC). The GRPBT composite containing the system achieved a V-0 classification in UL-94 testing (the thickness of testing bar was 0.8 mm). In microscale combustion calorimeter and cone calorimeter testing, both of the two different PHRRs (peak of heat release rate) for GRPBT composites were remarkably reduced by the incorporation ofthe novel system. Thermogravimetric analysis and residue characterization revealed that the addition of PC promoted the formation of char residues leading to the reduction of mass loss rate, which resulted in the improvement of fire retardancy. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697517 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Preparation and characterization of anatase TiO2 nanosheets - based microspheres for dye - sensitized solar cells Type de document : texte imprimé Auteurs : Yali Wang, Auteur ; Weiguang Yang, Auteur ; Weimin Shi, Auteur Année de publication : 2011 Article en page(s) : pp. 11982-11987 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Dyes Microsphere Titanium oxide Preparation Résumé : The one-pot synthesis of hierarchically structured anatase TiO2 nanosheets-based microspheres with controlled sizes is successfully achieved through the hydrolysis of titanium tetrafluoride in polyol medium with heating at 170 °C. Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS) are used to characterize the products. The effect of heat treatment on F- adsorbed on the surface of the nanosheets-based microspheres is investigated. In our work, fluorine ions from TiF4, diethylene glycol (DEG) as a solvent as well as a protective capping agent, and excess acetic acid play important roles in the formation of the dominantly exposed {001} facets and hierarchical structure. Due to the dominant exposure of high surface energy {001} facets, enlarged surface area, and improved light-scattering effect of the anatase TiO2 nanosheets-based microspheres, the dye-sensitized solar cell (DSSC) based on such materials exhibits cell performance superior to that of P25 TiO2. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697518
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11982-11987[article] Preparation and characterization of anatase TiO2 nanosheets - based microspheres for dye - sensitized solar cells [texte imprimé] / Yali Wang, Auteur ; Weiguang Yang, Auteur ; Weimin Shi, Auteur . - 2011 . - pp. 11982-11987.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11982-11987
Mots-clés : Dyes Microsphere Titanium oxide Preparation Résumé : The one-pot synthesis of hierarchically structured anatase TiO2 nanosheets-based microspheres with controlled sizes is successfully achieved through the hydrolysis of titanium tetrafluoride in polyol medium with heating at 170 °C. Field emission scanning electron microscopy (FESEM), X-ray diffraction (XRD), high-resolution transmission electron microscopy (HRTEM), and X-ray photoelectron spectroscopy (XPS) are used to characterize the products. The effect of heat treatment on F- adsorbed on the surface of the nanosheets-based microspheres is investigated. In our work, fluorine ions from TiF4, diethylene glycol (DEG) as a solvent as well as a protective capping agent, and excess acetic acid play important roles in the formation of the dominantly exposed {001} facets and hierarchical structure. Due to the dominant exposure of high surface energy {001} facets, enlarged surface area, and improved light-scattering effect of the anatase TiO2 nanosheets-based microspheres, the dye-sensitized solar cell (DSSC) based on such materials exhibits cell performance superior to that of P25 TiO2. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697518 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Fabrication and characterization of TiO2 nanotube – epoxy nanocomposites Type de document : texte imprimé Auteurs : Yu Wu, Auteur ; Lei Song, Auteur ; Yuan Hu, Auteur Année de publication : 2011 Article en page(s) : pp. 11988–11995 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Nanocomposite Titanium oxide Résumé : A systematic study has been conducted to investigate the polymer matrix properties resulting from the introduction of TiO2 nanotubes (1-5% by weight) that had been surface-modified with phenyl dichlorophosphate (PDCP), into an epoxy resin. The thermal, mechanical, and combustion properties of the nanocomposites and the neat resin were measured by thermogravimetric analysis, dynamic mechanical thermal analysis, and microscale combustion calorimetry. The nanofiller infusion improved the thermal and mechanical properties of the epoxy resin. The nanocomposites resulted in an increase in the storage modulus and glass transition temperature compared to those of the neat epoxy resin. In addition, the combustion characteristics of the epoxy polymer were effectively improved by addition of the surface-modified nanotubes. Thermogravimetric analysis/infrared spectrometry and direct pyrolysis mass spectrometry confirmed that the TiO2 nanotubes were able to improve the thermal stability and combustion behavior of the polymer matrix because the TNTs retard the release of inflammable gas and change the degradation pathway. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697519
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11988–11995[article] Fabrication and characterization of TiO2 nanotube – epoxy nanocomposites [texte imprimé] / Yu Wu, Auteur ; Lei Song, Auteur ; Yuan Hu, Auteur . - 2011 . - pp. 11988–11995.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11988–11995
Mots-clés : Nanocomposite Titanium oxide Résumé : A systematic study has been conducted to investigate the polymer matrix properties resulting from the introduction of TiO2 nanotubes (1-5% by weight) that had been surface-modified with phenyl dichlorophosphate (PDCP), into an epoxy resin. The thermal, mechanical, and combustion properties of the nanocomposites and the neat resin were measured by thermogravimetric analysis, dynamic mechanical thermal analysis, and microscale combustion calorimetry. The nanofiller infusion improved the thermal and mechanical properties of the epoxy resin. The nanocomposites resulted in an increase in the storage modulus and glass transition temperature compared to those of the neat epoxy resin. In addition, the combustion characteristics of the epoxy polymer were effectively improved by addition of the surface-modified nanotubes. Thermogravimetric analysis/infrared spectrometry and direct pyrolysis mass spectrometry confirmed that the TiO2 nanotubes were able to improve the thermal stability and combustion behavior of the polymer matrix because the TNTs retard the release of inflammable gas and change the degradation pathway. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697519 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Analysis of optimal control problems and plant debottlenecking for urea granulation circuits Type de document : texte imprimé Auteurs : Ivana M. Cotabarren, Auteur ; Diego Bertín, Auteur ; Juliana Pina, Auteur Année de publication : 2011 Article en page(s) : pp. 11996-12010 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Granulation Optimal control Résumé : The optimal control of a complete urea granulation circuit is studied in this work. The dynamic circuit operation is modeled by means of population, mass, and energy balances for the equipment of an industrial urea granulation flowsheet. The objective for the optimal control of the granulation circuit is to drive the process from a given steady-state (corresponding to the nominal capacity of a large-scale plant) to another one, by maximizing the throughput during the transient To this aim, realistic operating constraints are taken into account and, based on an analysis of the active physical limitations, different optimal control variables are selected (i.e., urea melt flow rate, granulator discharge area, and granulator fluidization air temperature and mass flow rate). The results provide new promising operating points, which can be achieved by tracking the calculated optimal time-trajectories for the selected control variables, and give insights into the main plant bottlenecks. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697520
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11996-12010[article] Analysis of optimal control problems and plant debottlenecking for urea granulation circuits [texte imprimé] / Ivana M. Cotabarren, Auteur ; Diego Bertín, Auteur ; Juliana Pina, Auteur . - 2011 . - pp. 11996-12010.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 11996-12010
Mots-clés : Granulation Optimal control Résumé : The optimal control of a complete urea granulation circuit is studied in this work. The dynamic circuit operation is modeled by means of population, mass, and energy balances for the equipment of an industrial urea granulation flowsheet. The objective for the optimal control of the granulation circuit is to drive the process from a given steady-state (corresponding to the nominal capacity of a large-scale plant) to another one, by maximizing the throughput during the transient To this aim, realistic operating constraints are taken into account and, based on an analysis of the active physical limitations, different optimal control variables are selected (i.e., urea melt flow rate, granulator discharge area, and granulator fluidization air temperature and mass flow rate). The results provide new promising operating points, which can be achieved by tracking the calculated optimal time-trajectories for the selected control variables, and give insights into the main plant bottlenecks. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697520 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Mixing and dissolution processes of pharmaceutical bulk materials in stirred tanks : experimental and numerical investigations Type de document : texte imprimé Auteurs : Thomas Hormann, Auteur ; Daniele Suzzi, Auteur ; Johannes G. Khinast, Auteur Année de publication : 2011 Article en page(s) : pp. 12011-12025 Note générale : Chimie induistrielle Langues : Anglais (eng) Mots-clés : Stirred vessel Bulk material Dissolution Mixing Résumé : Numerical analysis of mixing and dissolution processes is becoming increasingly important for graining a process understanding and thus optimizing the production. Due to the increasing costs and shortage of raw materials, "in-silico" techniques are currently employed together with standard experimental analyses. Numerical simulations have proven to be a useful tool for understanding and optimizing industrial mixing problems. However, such simulations are still in the research phase. Although Computational Fluid Dynamics (CFD) is a well-developed and validated method, for more complex applications (e.g., industrial mixing) much work is still required to obtain reliable results quickly enough. In this work we focused on the simulation of mixing and dissolution of a bulk powder in a moderately viscous solution in an unbaffled stirred tank reactor typically used in the chemical and pharmaceutical industries. Estimations were made with regard to optimizing batch sizes, tank geometry, impeller type, and placement and process variables, such as the impeller agitation speed. In addition, the vortex formation of the liquid surface, the feeding position of the bulk powder, and the dissolution process of the solid particles that represent the bulk powder were manipulated. Finally, a quantitative comparison of different stirring systems and scale-up studies was prepared. The time-dependent and turbulent flow of the mixture was studied by solving the Reynolds-averaged Navier-Stokes equations. The numerical predictions of the flow field were validated by means of high-speed camera images and particle image velodmetry postprocessing techniques. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697521
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12011-12025[article] Mixing and dissolution processes of pharmaceutical bulk materials in stirred tanks : experimental and numerical investigations [texte imprimé] / Thomas Hormann, Auteur ; Daniele Suzzi, Auteur ; Johannes G. Khinast, Auteur . - 2011 . - pp. 12011-12025.
Chimie induistrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12011-12025
Mots-clés : Stirred vessel Bulk material Dissolution Mixing Résumé : Numerical analysis of mixing and dissolution processes is becoming increasingly important for graining a process understanding and thus optimizing the production. Due to the increasing costs and shortage of raw materials, "in-silico" techniques are currently employed together with standard experimental analyses. Numerical simulations have proven to be a useful tool for understanding and optimizing industrial mixing problems. However, such simulations are still in the research phase. Although Computational Fluid Dynamics (CFD) is a well-developed and validated method, for more complex applications (e.g., industrial mixing) much work is still required to obtain reliable results quickly enough. In this work we focused on the simulation of mixing and dissolution of a bulk powder in a moderately viscous solution in an unbaffled stirred tank reactor typically used in the chemical and pharmaceutical industries. Estimations were made with regard to optimizing batch sizes, tank geometry, impeller type, and placement and process variables, such as the impeller agitation speed. In addition, the vortex formation of the liquid surface, the feeding position of the bulk powder, and the dissolution process of the solid particles that represent the bulk powder were manipulated. Finally, a quantitative comparison of different stirring systems and scale-up studies was prepared. The time-dependent and turbulent flow of the mixture was studied by solving the Reynolds-averaged Navier-Stokes equations. The numerical predictions of the flow field were validated by means of high-speed camera images and particle image velodmetry postprocessing techniques. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697521 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Dynamic scheduling for ethylene cracking furnace system Type de document : texte imprimé Auteurs : Chuanyu Zhao, Auteur ; Chaowei Liu, Auteur ; Qiang Xu, Auteur Année de publication : 2011 Article en page(s) : pp. 12026-12040 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Cracking Scheduling Résumé : The craking furnace system is crucial for an olefin plant. its operation needs to follow a predefined schelule to process various feeds continuously, meanwhile conducting a periodically decoking operation for each furnace when its performance apparently decreases. In practice, because the feed supply changes dynamically, the routine furnace scheduling is better performed in a dynamic and reactive way, through which the furnace operations can be smartly rescheduled with respect to any delivery of new coming feeds. Thus, the feeds from the new delivery and the leftover inventories can be timely, feasibly, and optimally allocated to different furnaces for processing to obtain the maximum average net profit per time. Facing this challenge, this paper develops a new MINLP-based reactive scheduling strategy, which can dynamically generate reschedules based on the new feed deliveries, the leftover feeds, and current furnace operating conditions. It simultaneously addresses all the major scheduling issues of a cracking furnace system, such as semicontinuous operation, nonsimultaneous decoking, secondary ethane cracking, and seamless rescheduling. The efficacy of the study and its significant economic potential are demonstrated by a comprehensive case study. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697522
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12026-12040[article] Dynamic scheduling for ethylene cracking furnace system [texte imprimé] / Chuanyu Zhao, Auteur ; Chaowei Liu, Auteur ; Qiang Xu, Auteur . - 2011 . - pp. 12026-12040.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12026-12040
Mots-clés : Cracking Scheduling Résumé : The craking furnace system is crucial for an olefin plant. its operation needs to follow a predefined schelule to process various feeds continuously, meanwhile conducting a periodically decoking operation for each furnace when its performance apparently decreases. In practice, because the feed supply changes dynamically, the routine furnace scheduling is better performed in a dynamic and reactive way, through which the furnace operations can be smartly rescheduled with respect to any delivery of new coming feeds. Thus, the feeds from the new delivery and the leftover inventories can be timely, feasibly, and optimally allocated to different furnaces for processing to obtain the maximum average net profit per time. Facing this challenge, this paper develops a new MINLP-based reactive scheduling strategy, which can dynamically generate reschedules based on the new feed deliveries, the leftover feeds, and current furnace operating conditions. It simultaneously addresses all the major scheduling issues of a cracking furnace system, such as semicontinuous operation, nonsimultaneous decoking, secondary ethane cracking, and seamless rescheduling. The efficacy of the study and its significant economic potential are demonstrated by a comprehensive case study. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697522 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Review and analysis of blood glucose (BG) models for type 1 diabetic patients Type de document : texte imprimé Auteurs : Naviyn Prabhu Balakrishnan, Auteur ; Gade Pandu Rangaiah, Auteur ; Lakshminarayanan Samavedham, Auteur Année de publication : 2011 Article en page(s) : pp. 12041-12066 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Modeling Résumé : Blood glucose (BG) regulation in type 1 diabetic patients has been investigated by researchers for a long time. Manv mathematical models mimicking the physiological behavior of diabetic patients have been developed to predict BG variations. Models characterizing meal absorption and physical activities have also been developed in the literature, as they play a significant role in altering BG levels. Hence, existing glucose-insulin dynamic models dating back from early 1960s are reviewed along with an overview of meal absorption and exercise effect models. The available knowledge-driven BG models have been classified into different families based on their origin for development. Also, five knowledge-driven BG models (with at least one model from a family) have been analyzed by either varying basal insulin or meal ingestion. The available meal absorption models have also been simulated to compare and analyze them for different meal sizes. The major objective of the analysis is to study the BG dynamics of different models at their nominal parameter values, under varying basal insulin doses and meal ingestion. Similar analysis has been performed on 10 adult patient models in a recent benchmark simulator for comparison. These results will be useful for understanding the responses of different BG models at their nominal parameter values and for preliminary selection of a suitable treatment model(s) for a patient. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697523
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12041-12066[article] Review and analysis of blood glucose (BG) models for type 1 diabetic patients [texte imprimé] / Naviyn Prabhu Balakrishnan, Auteur ; Gade Pandu Rangaiah, Auteur ; Lakshminarayanan Samavedham, Auteur . - 2011 . - pp. 12041-12066.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12041-12066
Mots-clés : Modeling Résumé : Blood glucose (BG) regulation in type 1 diabetic patients has been investigated by researchers for a long time. Manv mathematical models mimicking the physiological behavior of diabetic patients have been developed to predict BG variations. Models characterizing meal absorption and physical activities have also been developed in the literature, as they play a significant role in altering BG levels. Hence, existing glucose-insulin dynamic models dating back from early 1960s are reviewed along with an overview of meal absorption and exercise effect models. The available knowledge-driven BG models have been classified into different families based on their origin for development. Also, five knowledge-driven BG models (with at least one model from a family) have been analyzed by either varying basal insulin or meal ingestion. The available meal absorption models have also been simulated to compare and analyze them for different meal sizes. The major objective of the analysis is to study the BG dynamics of different models at their nominal parameter values, under varying basal insulin doses and meal ingestion. Similar analysis has been performed on 10 adult patient models in a recent benchmark simulator for comparison. These results will be useful for understanding the responses of different BG models at their nominal parameter values and for preliminary selection of a suitable treatment model(s) for a patient. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697523 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Simulation - based process design and integration for the sustainable retrofit of chemical processes Type de document : texte imprimé Auteurs : Aurora Hernández Enríquez, Auteur ; Martin Tanco, Auteur Année de publication : 2011 Article en page(s) : pp. 12067-12079 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Design Résumé : This research proposes a novel Retrofit Design Approach based on process simulation and the Response Surface Methodology (RSM). The approach comprises a diagnosis stage to select the promising variables through a sensitivity analysis, an evaluation stage to assess the impact of the promising variables, and to identify the most important factors through RSM.A reduced model from the process response behavior is built, and an optimization is carried out with the reduced model to identify optimal conditions and performance of the system, subject to objective function and model constraints. All these procedures are simulation-supported. The main advantage of the proposed approach is to handle a large industrial-scale design problem within a reasonable computational effort and to obtain a reduced model based on the most important factors. Limitations for the developed method include that the global optimality ofthe solutions found is not fully guaranteed, while large computational time for simulation maybe required when the large number of factors and levels need to be considered, although this is offset by the reduced optimization time. The proposed Retrofit Design Approach has been applied to the NGL (natural gas liquids) recovery process, in which steady-state process simulation using Aspen Plus TM has been carried out, and complex design interactions existed for retrofit scenarios have been systematically evaluated, leading to optimal strategies for retrofitting through the proposed design method. Both the continuous and discrete design options are considered in the retrofit design, and the results showed that the approach is effective to provide reliable, cost-effective solutions which yield to economic and environmental improvements in the studied processes. The promising sets of retrofit design options were presented as a portfolio of investment opportunities for supporting further decision-making procedures DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697524
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12067-12079[article] Simulation - based process design and integration for the sustainable retrofit of chemical processes [texte imprimé] / Aurora Hernández Enríquez, Auteur ; Martin Tanco, Auteur . - 2011 . - pp. 12067-12079.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12067-12079
Mots-clés : Design Résumé : This research proposes a novel Retrofit Design Approach based on process simulation and the Response Surface Methodology (RSM). The approach comprises a diagnosis stage to select the promising variables through a sensitivity analysis, an evaluation stage to assess the impact of the promising variables, and to identify the most important factors through RSM.A reduced model from the process response behavior is built, and an optimization is carried out with the reduced model to identify optimal conditions and performance of the system, subject to objective function and model constraints. All these procedures are simulation-supported. The main advantage of the proposed approach is to handle a large industrial-scale design problem within a reasonable computational effort and to obtain a reduced model based on the most important factors. Limitations for the developed method include that the global optimality ofthe solutions found is not fully guaranteed, while large computational time for simulation maybe required when the large number of factors and levels need to be considered, although this is offset by the reduced optimization time. The proposed Retrofit Design Approach has been applied to the NGL (natural gas liquids) recovery process, in which steady-state process simulation using Aspen Plus TM has been carried out, and complex design interactions existed for retrofit scenarios have been systematically evaluated, leading to optimal strategies for retrofitting through the proposed design method. Both the continuous and discrete design options are considered in the retrofit design, and the results showed that the approach is effective to provide reliable, cost-effective solutions which yield to economic and environmental improvements in the studied processes. The promising sets of retrofit design options were presented as a portfolio of investment opportunities for supporting further decision-making procedures DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697524 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Parameter estimation in batch bioreactor simulation using metabolic models : sequential solution with direct sensitivities Type de document : texte imprimé Auteurs : Juha T. Leppävuori, Auteur Année de publication : 2011 Article en page(s) : pp. 12080-12091 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Sensitivity analysis Modeling Bioreactor Batchwise Parameter estimation Résumé : In this study, we propose a parameter estimation method for genome-scale dynamic flux balance (DFBA) models. A bilevel optimization problem is reformulated as a differential-algebraic equation (DAE) optimization problem and solved sequentially, using gradient-based optimization with direct sensitivity equations. The resulting solution method is computationally efficient for today's largest genome-scale metabolic models. The parameter estimation method combined with parameter selection algorithm is applied on simulated and experimental data. This paper presents the parameter estimation and selection method and numerical results of estimation of kinetic parameters of the DFBA model of anaerobic batch fermentation. The results show improved computational performance over previous approaches, thus making parameter estimation available for genome-scale DFBA models. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697525
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12080-12091[article] Parameter estimation in batch bioreactor simulation using metabolic models : sequential solution with direct sensitivities [texte imprimé] / Juha T. Leppävuori, Auteur . - 2011 . - pp. 12080-12091.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12080-12091
Mots-clés : Sensitivity analysis Modeling Bioreactor Batchwise Parameter estimation Résumé : In this study, we propose a parameter estimation method for genome-scale dynamic flux balance (DFBA) models. A bilevel optimization problem is reformulated as a differential-algebraic equation (DAE) optimization problem and solved sequentially, using gradient-based optimization with direct sensitivity equations. The resulting solution method is computationally efficient for today's largest genome-scale metabolic models. The parameter estimation method combined with parameter selection algorithm is applied on simulated and experimental data. This paper presents the parameter estimation and selection method and numerical results of estimation of kinetic parameters of the DFBA model of anaerobic batch fermentation. The results show improved computational performance over previous approaches, thus making parameter estimation available for genome-scale DFBA models. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697525 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Start - up and dynamic analysis of a novel thermally coupled reactor for the simultaneous production of methanol and benzene Type de document : texte imprimé Auteurs : Mohammad Hasan Khademi, Auteur ; Mohammad Reza Rahimpour, Auteur ; Abdolhossein Jahanmiri, Auteur Année de publication : 2011 Article en page(s) : pp. 12092-12102 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Production Reactor Résumé : Coupling energy intensive endothermic reaction systems with suitable exothermic reactions improves the thermal efficiency of processes, achieving the autothermality within the reactor, reducing the size of the reactors, and achieving a multiple reactants-multiple products configuration. In this study, a dynamic heterogeneous model for a novel thermally coupled reactor-containing methanol synthesis reactions and cyclohexane dehydrogenation-is developed to consider the startup and transient response of the system. This heat-exchanger reactor consists of two fixed beds separated by a wall, where heat is transferred across the surface of tube from the exothermic side to the endothermic side. The proposed model was validated against conventional methanol synthesis reactor, and a good agreement was achieved. Dynamic simulation results for the co-current mode have been investigated to present the response of the reactor outlet temperature, methanol yield, and cyclohexane conversion in the cases of a step change in the initial molar flow rate and inlet temperature of both sides. The challenges posed by the transient operation of thermally coupled reactor are identified to avoid severe issues that can arise in the course of operating the reactor (such as reactor extinction). The results suggest that control of this coupled reactor could be feasible and beneficial. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697526
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12092-12102[article] Start - up and dynamic analysis of a novel thermally coupled reactor for the simultaneous production of methanol and benzene [texte imprimé] / Mohammad Hasan Khademi, Auteur ; Mohammad Reza Rahimpour, Auteur ; Abdolhossein Jahanmiri, Auteur . - 2011 . - pp. 12092-12102.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12092-12102
Mots-clés : Production Reactor Résumé : Coupling energy intensive endothermic reaction systems with suitable exothermic reactions improves the thermal efficiency of processes, achieving the autothermality within the reactor, reducing the size of the reactors, and achieving a multiple reactants-multiple products configuration. In this study, a dynamic heterogeneous model for a novel thermally coupled reactor-containing methanol synthesis reactions and cyclohexane dehydrogenation-is developed to consider the startup and transient response of the system. This heat-exchanger reactor consists of two fixed beds separated by a wall, where heat is transferred across the surface of tube from the exothermic side to the endothermic side. The proposed model was validated against conventional methanol synthesis reactor, and a good agreement was achieved. Dynamic simulation results for the co-current mode have been investigated to present the response of the reactor outlet temperature, methanol yield, and cyclohexane conversion in the cases of a step change in the initial molar flow rate and inlet temperature of both sides. The challenges posed by the transient operation of thermally coupled reactor are identified to avoid severe issues that can arise in the course of operating the reactor (such as reactor extinction). The results suggest that control of this coupled reactor could be feasible and beneficial. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697526 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Optimization study of steelmaking under novel blast furnace operation combined with methanol production Type de document : texte imprimé Auteurs : Hamid Ghanbari, Auteur ; Mikko Helle, Auteur ; Frank Pettersson, Auteur Année de publication : 2011 Article en page(s) : pp. 12103-12112 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Production Blast furnace Optimization Résumé : The opportunities to improve the performance of an existing production concept by plant retrofit are largely dependent on the available knowledge of the best operational state of the plant and its parameters and conditions. In this paper, nonlinear programming was used to analyze the economic potential of the use of large volumes of gases in a steel plant to produce methanol as a valuable byproduct in steelmaking. Conventional blast furnace operation was compared with the option of operating the blast furnace with top gas recycling after carbon dioxide stripping. The optimal integration of the processes was investigated by minimizing the cost of liquid steel production, considering the cost of raw materials and fuels, CO2 emission, and stripping, as well as credits for power, district heat, and methanol production. It was found that the novel way of operating the blast furnace with cold oxygen blowing and top gas recycling was well suited for combination with a polygeneration system using the residual gases of the steel plant. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697527
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12103-12112[article] Optimization study of steelmaking under novel blast furnace operation combined with methanol production [texte imprimé] / Hamid Ghanbari, Auteur ; Mikko Helle, Auteur ; Frank Pettersson, Auteur . - 2011 . - pp. 12103-12112.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12103-12112
Mots-clés : Production Blast furnace Optimization Résumé : The opportunities to improve the performance of an existing production concept by plant retrofit are largely dependent on the available knowledge of the best operational state of the plant and its parameters and conditions. In this paper, nonlinear programming was used to analyze the economic potential of the use of large volumes of gases in a steel plant to produce methanol as a valuable byproduct in steelmaking. Conventional blast furnace operation was compared with the option of operating the blast furnace with top gas recycling after carbon dioxide stripping. The optimal integration of the processes was investigated by minimizing the cost of liquid steel production, considering the cost of raw materials and fuels, CO2 emission, and stripping, as well as credits for power, district heat, and methanol production. It was found that the novel way of operating the blast furnace with cold oxygen blowing and top gas recycling was well suited for combination with a polygeneration system using the residual gases of the steel plant. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697527 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Effect of nano-TiO2 particles on the performance of PVDF, PVDF - g - (Maleic anhydride), and PVDF - g - poly(acryl amide) membranes Type de document : texte imprimé Auteurs : Xiaokai Bian, Auteur ; Liuqing Shi, Auteur ; Xuanxuan Yang, Auteur Année de publication : 2011 Article en page(s) : pp. 12113-12123 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Nanoparticles Polymer membranes Résumé : To study the effects of nano-TiO2 particles on membrane performance and structure and to explore possible interactions between nano-TiO2 particles and polymer, polymer/TiO2 embedded hybrid membranes and neat polymer membranes were prepared using the phase inversion method. Poly(vinylidene difluoride) (PVDF), poly(vinylidene difluoride)-g-(maleic anhydride) (PVDF-g-MA), and poly(vinylidene difluoride)-g-poly(acryl amide) (PVDF-g-PAM) were selected as the membrane materials. SEM images showed that the hybrid membranes had a thinner skin layer and a larger number ofpores in the sublayer than the neat membranes, which was the main cause of the increase in water flux of the hybrid membranes. They also exhibited a better antifouling property than the neat ones in the continuous BSA solution filtration process. In the 48-h-long pure-water experiment, the hybrid membranes underwent a water flux decline and an increase in contact angle. The loss of nano-TiO2 particles, revealed by EDS analysis, influenced the stability of hybrid membrane performance. The XPS analysis suggested that nano-TiO2 particles were immobilized in the membrane surface layer through the formation of a stable chemical structure resulting from its reaction with polymer and/or through intertwining with polymer chains. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200232u
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12113-12123[article] Effect of nano-TiO2 particles on the performance of PVDF, PVDF - g - (Maleic anhydride), and PVDF - g - poly(acryl amide) membranes [texte imprimé] / Xiaokai Bian, Auteur ; Liuqing Shi, Auteur ; Xuanxuan Yang, Auteur . - 2011 . - pp. 12113-12123.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12113-12123
Mots-clés : Nanoparticles Polymer membranes Résumé : To study the effects of nano-TiO2 particles on membrane performance and structure and to explore possible interactions between nano-TiO2 particles and polymer, polymer/TiO2 embedded hybrid membranes and neat polymer membranes were prepared using the phase inversion method. Poly(vinylidene difluoride) (PVDF), poly(vinylidene difluoride)-g-(maleic anhydride) (PVDF-g-MA), and poly(vinylidene difluoride)-g-poly(acryl amide) (PVDF-g-PAM) were selected as the membrane materials. SEM images showed that the hybrid membranes had a thinner skin layer and a larger number ofpores in the sublayer than the neat membranes, which was the main cause of the increase in water flux of the hybrid membranes. They also exhibited a better antifouling property than the neat ones in the continuous BSA solution filtration process. In the 48-h-long pure-water experiment, the hybrid membranes underwent a water flux decline and an increase in contact angle. The loss of nano-TiO2 particles, revealed by EDS analysis, influenced the stability of hybrid membrane performance. The XPS analysis suggested that nano-TiO2 particles were immobilized in the membrane surface layer through the formation of a stable chemical structure resulting from its reaction with polymer and/or through intertwining with polymer chains. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie200232u Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Novel approach to recover natural antioxidants from oil seed meal in ultrafiltration - nanofiltration - based technique Type de document : texte imprimé Auteurs : Ranjana Das, Auteur ; Chiranjib Bhattacharjee, Auteur ; Santinath Ghosh, Auteur Année de publication : 2011 Article en page(s) : pp. 12124-12133 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Nanofiltration Membrane separation Ultrafiltration Antioxidant Résumé : This study describes an innovative approach for recovery and concentration of sesame glucosides from defatted sesame cake using membrane separation route. Simple aqueous extraction of the seed meal at suitable pH value followed by two steps membrane fractionation (ultrafiltration-nanofiltration) was done to obtain sesame glucoside concentrate. In this process, about 0.7% ± 0.29 recovery of total meal glucoside was achieved along with coproduct sesame protein isolate at yield value of 36.50%. Several in vitro analyses were carried out to assay the antioxidative potential of recovered glucosides in different reaction models. Recovered glucosides have shown comparable α,α'-diphenyl-1-picryl-hydrazyl radical scavenging activity and Cu2+ ion chelation capacity with solvent extracted glucosides. Sesame glucosides have shown unique antioxidant activity for 29 h in an induced oxidation system of linoleic acid emulsion. This study includes a detail analysis on membrane performance parameters and fouling characteristics of ultrafiltration membrane, which are crucial factors to consider for industrial relevance. All findings point toward the potentiality of ultrafiltration-nanofiltration-based technique for recovery of polar antioxidants from various raw materials. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697529
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12124-12133[article] Novel approach to recover natural antioxidants from oil seed meal in ultrafiltration - nanofiltration - based technique [texte imprimé] / Ranjana Das, Auteur ; Chiranjib Bhattacharjee, Auteur ; Santinath Ghosh, Auteur . - 2011 . - pp. 12124-12133.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12124-12133
Mots-clés : Nanofiltration Membrane separation Ultrafiltration Antioxidant Résumé : This study describes an innovative approach for recovery and concentration of sesame glucosides from defatted sesame cake using membrane separation route. Simple aqueous extraction of the seed meal at suitable pH value followed by two steps membrane fractionation (ultrafiltration-nanofiltration) was done to obtain sesame glucoside concentrate. In this process, about 0.7% ± 0.29 recovery of total meal glucoside was achieved along with coproduct sesame protein isolate at yield value of 36.50%. Several in vitro analyses were carried out to assay the antioxidative potential of recovered glucosides in different reaction models. Recovered glucosides have shown comparable α,α'-diphenyl-1-picryl-hydrazyl radical scavenging activity and Cu2+ ion chelation capacity with solvent extracted glucosides. Sesame glucosides have shown unique antioxidant activity for 29 h in an induced oxidation system of linoleic acid emulsion. This study includes a detail analysis on membrane performance parameters and fouling characteristics of ultrafiltration membrane, which are crucial factors to consider for industrial relevance. All findings point toward the potentiality of ultrafiltration-nanofiltration-based technique for recovery of polar antioxidants from various raw materials. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697529 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Absorption Mass-Transfer Characteristics of Mellapak Packings Series Type de document : texte imprimé Auteurs : L. Valenz, Auteur ; F. J. Rejl, Auteur ; J. Síma, Auteur Année de publication : 2011 Article en page(s) : pp. 12134-12142 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Mass transfer Résumé : Mass-transfer characteristics were measured for the Mellapak structured packing series 250Y, 350Y, 452Y, and 500Y. kLa was measured by oxygen desorption from water and the effective mass-transfer area a by absorption of CO2 into NaOH solution and also by oxygen absorption into a sulfite solution. Using Bodenstein numbers determined by means of the "cold" air-water dynamic experiments, effects of gas- and liquid-phase axial mixing on the characteristics were evaluated for Mellapak 250Y. Strikingly large differences found between the mass-transfer parameters and their flow dependencies measured in this work and those predicted by models especially designed for the prediction of the parameters in corrugated sheet structured packings (Billet, R.; Schultes, M. Chem. Eng. Res. Des. 1999, 77, 498; Rocha, J. A.; Bravo, J. L.; Fair, J. R. Ind. Eng. Chem. Res. 1996, 35, 1660; Olujić, Z.; Kamerbeek, A. B.; Graauw, J. Chem. Eng. Process. 1999,38,683) demonstrate the bad physical relevance of the parameters predicted. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697530
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12134-12142[article] Absorption Mass-Transfer Characteristics of Mellapak Packings Series [texte imprimé] / L. Valenz, Auteur ; F. J. Rejl, Auteur ; J. Síma, Auteur . - 2011 . - pp. 12134-12142.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12134-12142
Mots-clés : Mass transfer Résumé : Mass-transfer characteristics were measured for the Mellapak structured packing series 250Y, 350Y, 452Y, and 500Y. kLa was measured by oxygen desorption from water and the effective mass-transfer area a by absorption of CO2 into NaOH solution and also by oxygen absorption into a sulfite solution. Using Bodenstein numbers determined by means of the "cold" air-water dynamic experiments, effects of gas- and liquid-phase axial mixing on the characteristics were evaluated for Mellapak 250Y. Strikingly large differences found between the mass-transfer parameters and their flow dependencies measured in this work and those predicted by models especially designed for the prediction of the parameters in corrugated sheet structured packings (Billet, R.; Schultes, M. Chem. Eng. Res. Des. 1999, 77, 498; Rocha, J. A.; Bravo, J. L.; Fair, J. R. Ind. Eng. Chem. Res. 1996, 35, 1660; Olujić, Z.; Kamerbeek, A. B.; Graauw, J. Chem. Eng. Process. 1999,38,683) demonstrate the bad physical relevance of the parameters predicted. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697530 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Removal and recycling of inherent inorganic nutrient species in mallee biomass and derived biochars by water leaching Type de document : texte imprimé Auteurs : Hongwei Wu, Auteur ; Kongvui Yip, Auteur ; Zhaoying Kong, Auteur Année de publication : 2011 Article en page(s) : pp. 12143-12151 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Lixiviation Biomass Recycling Résumé : Biomass growth extracts inorganic nutrients from soil as inherent nutrient species in the biomass. Unless at least some of these inherent inorganic nutrients are eventually recycled to the soil, biomass utilization during its full life cycle may not be sustainable. This study reports the removal and recycling of inherent inorganic species in mallee biomass and its derived biochars by water leaching. A series of biochars were produced from the pyrolysis of various mallee components including wood, leaf, and bark under various conditions. An increasing pyrolysis temperature leads to increases in biochar C content and aromaticity and decreases in biochar H and O contents as well as oxygen functional groups. Most of the alkali and alkaline earth metallic species (Na, K, Mg, and Ca) and P are retained in the biochars, while substantial amounts of S, N, and Cl are released during pyrolysis. For biomass samples, almost all of K, Na, and Cl and large proportions of S, P, and Mg can be recycled by water leaching, but limited Ca and little N can be recycled. However, nutrients recycling via water leaching of biochars results in substantial reductions in the overall recycling of most nutrient species orignally present in biomass, due to either substantial release of nutrients (Cl, S, and N) during pyrolysis or the forms of nutrient species (Na, K, Mg, P) in biochars becoming increasingly water insoluble. The results also suggest that heat treatment may be employed to tune the biochars to facilitate the recycling of Ca which is the dominant inherent inorganic nutrient species of the samples investigated. It is noted that water leaching can also remove small amounts of organic matter, generally DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697531
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12143-12151[article] Removal and recycling of inherent inorganic nutrient species in mallee biomass and derived biochars by water leaching [texte imprimé] / Hongwei Wu, Auteur ; Kongvui Yip, Auteur ; Zhaoying Kong, Auteur . - 2011 . - pp. 12143-12151.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12143-12151
Mots-clés : Lixiviation Biomass Recycling Résumé : Biomass growth extracts inorganic nutrients from soil as inherent nutrient species in the biomass. Unless at least some of these inherent inorganic nutrients are eventually recycled to the soil, biomass utilization during its full life cycle may not be sustainable. This study reports the removal and recycling of inherent inorganic species in mallee biomass and its derived biochars by water leaching. A series of biochars were produced from the pyrolysis of various mallee components including wood, leaf, and bark under various conditions. An increasing pyrolysis temperature leads to increases in biochar C content and aromaticity and decreases in biochar H and O contents as well as oxygen functional groups. Most of the alkali and alkaline earth metallic species (Na, K, Mg, and Ca) and P are retained in the biochars, while substantial amounts of S, N, and Cl are released during pyrolysis. For biomass samples, almost all of K, Na, and Cl and large proportions of S, P, and Mg can be recycled by water leaching, but limited Ca and little N can be recycled. However, nutrients recycling via water leaching of biochars results in substantial reductions in the overall recycling of most nutrient species orignally present in biomass, due to either substantial release of nutrients (Cl, S, and N) during pyrolysis or the forms of nutrient species (Na, K, Mg, P) in biochars becoming increasingly water insoluble. The results also suggest that heat treatment may be employed to tune the biochars to facilitate the recycling of Ca which is the dominant inherent inorganic nutrient species of the samples investigated. It is noted that water leaching can also remove small amounts of organic matter, generally DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697531 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Carbon dioxide - selective membranes for high - pressure synthesis gas purification Type de document : texte imprimé Auteurs : He Bai, Auteur ; W. S. Winston Ho, Auteur Année de publication : 2011 Article en page(s) : pp. 12152-12161 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Gas purification Synthesis gas Carbon dioxide Résumé : The CO2-selective facilitated transport membranes baced on cross-linked poly(vinyl alcohol) (PVA) and sulfonated polybenzimidazole (SPBI) matrixes were synthesized and characterized for high-pressure synthesis gas purification. The cross-linked PVA-based membranes showed CO2/H2 selectivity higher than 30 and CO2 permeability as high as close to 1000 barrers for a membrane thickness of 15-30 μm at a feed pressure of 220 psia, which are desirable for the intended gas purification. The SPBI-based membranes generally showed lower separation performance because of their lower hydrophilicity. The cross-linked PVA-based membranes showed the best separation performance at 106 °C. However, the SPBI-1 copolymer-based membranes exhibited the best separation performance at 100 °C because of also their lower hydrophilicity. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697532
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12152-12161[article] Carbon dioxide - selective membranes for high - pressure synthesis gas purification [texte imprimé] / He Bai, Auteur ; W. S. Winston Ho, Auteur . - 2011 . - pp. 12152-12161.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12152-12161
Mots-clés : Gas purification Synthesis gas Carbon dioxide Résumé : The CO2-selective facilitated transport membranes baced on cross-linked poly(vinyl alcohol) (PVA) and sulfonated polybenzimidazole (SPBI) matrixes were synthesized and characterized for high-pressure synthesis gas purification. The cross-linked PVA-based membranes showed CO2/H2 selectivity higher than 30 and CO2 permeability as high as close to 1000 barrers for a membrane thickness of 15-30 μm at a feed pressure of 220 psia, which are desirable for the intended gas purification. The SPBI-based membranes generally showed lower separation performance because of their lower hydrophilicity. The cross-linked PVA-based membranes showed the best separation performance at 106 °C. However, the SPBI-1 copolymer-based membranes exhibited the best separation performance at 100 °C because of also their lower hydrophilicity. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697532 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Simulation of turbulent flow in square cyclone separator with different gas exhaust Type de document : texte imprimé Auteurs : Yaxin Su, Auteur ; Bingtao Zhao, Auteur ; Anqiao Zheng, Auteur Année de publication : 2011 Article en page(s) : pp. 12162-12169 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Cyclone separator Turbulent flow Résumé : The gas-solid turbulent flow and separation processes in square cyclone senarators are numerically modeled by the computational fluid dynamics (CFD) method. The Reynolds stress model (RSM) is used to simulate the gas flow and the Lagrangian model is used to calculate the particle motion. Three types of gas exhaust are investigated, including the circular gas exhaust and two types of square gas exhaust with different arrangement. The simulated separation efficiency and pressure drop of the cyclone with the circular gas exhaust are compared to experimental data to verify the present CFD model. The effect of gas exhaust configuration on the turbulent flow characteristics in the separator is discussed and compared for the three types of gas exhaust. The results show that the separation efficiency increases and the pressure drop decreases when the square gas exhaust is used to take place of the circular gas exhaust of the same cross section. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697533
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12162-12169[article] Simulation of turbulent flow in square cyclone separator with different gas exhaust [texte imprimé] / Yaxin Su, Auteur ; Bingtao Zhao, Auteur ; Anqiao Zheng, Auteur . - 2011 . - pp. 12162-12169.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12162-12169
Mots-clés : Cyclone separator Turbulent flow Résumé : The gas-solid turbulent flow and separation processes in square cyclone senarators are numerically modeled by the computational fluid dynamics (CFD) method. The Reynolds stress model (RSM) is used to simulate the gas flow and the Lagrangian model is used to calculate the particle motion. Three types of gas exhaust are investigated, including the circular gas exhaust and two types of square gas exhaust with different arrangement. The simulated separation efficiency and pressure drop of the cyclone with the circular gas exhaust are compared to experimental data to verify the present CFD model. The effect of gas exhaust configuration on the turbulent flow characteristics in the separator is discussed and compared for the three types of gas exhaust. The results show that the separation efficiency increases and the pressure drop decreases when the square gas exhaust is used to take place of the circular gas exhaust of the same cross section. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697533 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Synergistic effect in the solvent extraction and separation of lanthanoids by 4 - (4 - Fluorobenzoyl) - 3 - methyl - 1 - phenyl - pyrazol - 5 - one in the presence of monofunctional neutral organophosphorus extractants Type de document : texte imprimé Auteurs : Maria A. Petrova, Auteur ; Vanya B. Kurteva, Auteur ; Lubomir A. Lubenov, Auteur Année de publication : 2011 Article en page(s) : pp. 12170-12176 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Solvent extraction Synergism Résumé : 4-(4-Fluorobenzoyl)-3-methyl-1-phenyl-pyrazol-5-one (HL) has been synthesized and its complexation properties in solution were examined. Mixed ligand chelate extraction of trivalent lanthanoids (La, Nd, Eu, Ho, and Lu) from chloride medium at constant ionic strength μ = 0.1 into C6H6 with HL in combination with one of the three phosphine oxide compounds trioctylphosphine oxide (TOPO), tributylphosphine oxide (TBPO), or triphenylphosphine oxide (TPPO) as well as with tributylphosphate (TBP) was studied. The interaction between the extractants in C6H6-d6 has been studied by 1H, 13C, and 31P NMR spectroscopy and its influence on the synergistic extraction of Nd(III) ion has been investigated. The composition of the extracted species was established as LnL3·HL with HL alone and as LnL3·2S in the presence of TOPO, TPPO, and TBP or LnL3·S with the mixture of HL-TBPO. A synergic effect up to 106 was observed for the extraction of the above-mentioned lanthanoid ions with binary mixtures of extractants. The change of the synergistic agent causes a significant increase of the KL,S values. The parameters of the extraction process were determined and the separation factors were calculated. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697534
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12170-12176[article] Synergistic effect in the solvent extraction and separation of lanthanoids by 4 - (4 - Fluorobenzoyl) - 3 - methyl - 1 - phenyl - pyrazol - 5 - one in the presence of monofunctional neutral organophosphorus extractants [texte imprimé] / Maria A. Petrova, Auteur ; Vanya B. Kurteva, Auteur ; Lubomir A. Lubenov, Auteur . - 2011 . - pp. 12170-12176.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12170-12176
Mots-clés : Solvent extraction Synergism Résumé : 4-(4-Fluorobenzoyl)-3-methyl-1-phenyl-pyrazol-5-one (HL) has been synthesized and its complexation properties in solution were examined. Mixed ligand chelate extraction of trivalent lanthanoids (La, Nd, Eu, Ho, and Lu) from chloride medium at constant ionic strength μ = 0.1 into C6H6 with HL in combination with one of the three phosphine oxide compounds trioctylphosphine oxide (TOPO), tributylphosphine oxide (TBPO), or triphenylphosphine oxide (TPPO) as well as with tributylphosphate (TBP) was studied. The interaction between the extractants in C6H6-d6 has been studied by 1H, 13C, and 31P NMR spectroscopy and its influence on the synergistic extraction of Nd(III) ion has been investigated. The composition of the extracted species was established as LnL3·HL with HL alone and as LnL3·2S in the presence of TOPO, TPPO, and TBP or LnL3·S with the mixture of HL-TBPO. A synergic effect up to 106 was observed for the extraction of the above-mentioned lanthanoid ions with binary mixtures of extractants. The change of the synergistic agent causes a significant increase of the KL,S values. The parameters of the extraction process were determined and the separation factors were calculated. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697534 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Adsorption of organic compounds in vapor, liquid, and aqueous solution phases on hydrophobic aerogels Type de document : texte imprimé Auteurs : Ding Wang, Auteur ; Elisabeth McLaughlin, Auteur ; Robert Pfeffer, Auteur Année de publication : 2011 Article en page(s) : pp. 12177–12185 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : kinetics Adsorption Organic compounds Aqueous Solution Résumé : The kinetics and equilibrium capacity for adsorption of six volatile organic compounds (VOCs) in the vapor, pure liquid, and aqueous solution phases on commercially available hydrophobic silica aerogel granules (Cabot Nanogel) were studied at room temperature. Very different rates of adsorption were observed depending on whether the vapor, liquid, or solution phases were used. Adsorption of vapor is very slow due to the extremely low thermal conductivity of the aerogel. Effects of heat of adsorption are minimal for the liquid and solution phases, and the faster adsorption rates observed in these two cases are controlled by the mass transport of the organic compounds, either by capillary flow for the adsorption of liquids, or by vapor diffusion/adsorption for the adsorption of the organic compounds from water solutions. The equilibrium adsorption capacities of the aerogel were measured and compared to other sorbents for similar VOCs for the three different phases. The adsorption capacity of the commercial aerogel from the vapor phase studied in this work is higher than that of two other hydrophobic aerogels that were synthesized in the laboratory using supercritical drying, and much higher than that of two commercial sorbents (silica gel and activated carbon). The volumetric sorption capacities of all of the organic liquids studied on Nanogel are all around 16 mL/g. The equilibrium adsorption capacities of the six VOCs from aqueous solution increase in the following order: benzene DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201301n
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12177–12185[article] Adsorption of organic compounds in vapor, liquid, and aqueous solution phases on hydrophobic aerogels [texte imprimé] / Ding Wang, Auteur ; Elisabeth McLaughlin, Auteur ; Robert Pfeffer, Auteur . - 2011 . - pp. 12177–12185.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12177–12185
Mots-clés : kinetics Adsorption Organic compounds Aqueous Solution Résumé : The kinetics and equilibrium capacity for adsorption of six volatile organic compounds (VOCs) in the vapor, pure liquid, and aqueous solution phases on commercially available hydrophobic silica aerogel granules (Cabot Nanogel) were studied at room temperature. Very different rates of adsorption were observed depending on whether the vapor, liquid, or solution phases were used. Adsorption of vapor is very slow due to the extremely low thermal conductivity of the aerogel. Effects of heat of adsorption are minimal for the liquid and solution phases, and the faster adsorption rates observed in these two cases are controlled by the mass transport of the organic compounds, either by capillary flow for the adsorption of liquids, or by vapor diffusion/adsorption for the adsorption of the organic compounds from water solutions. The equilibrium adsorption capacities of the aerogel were measured and compared to other sorbents for similar VOCs for the three different phases. The adsorption capacity of the commercial aerogel from the vapor phase studied in this work is higher than that of two other hydrophobic aerogels that were synthesized in the laboratory using supercritical drying, and much higher than that of two commercial sorbents (silica gel and activated carbon). The volumetric sorption capacities of all of the organic liquids studied on Nanogel are all around 16 mL/g. The equilibrium adsorption capacities of the six VOCs from aqueous solution increase in the following order: benzene DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201301n Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Evaporation crystallization of RDX by ultrasonic spray Type de document : texte imprimé Auteurs : Jun-Woo Kim, Auteur ; Moon-Soo Shin, Auteur ; Jae-Kyeong Kim, Auteur Année de publication : 2011 Article en page(s) : pp. 12186-12193 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Crystallization Evaporation Résumé : Cyclotrimethylene trinitramine (RDX) with size of 0.8 to 2.6 μm was produced by evaporation crystallization of RDX with ultrasonic spray. In the experimental range of the present work, the size of RDX crystals was found to be strongly affected by operating parameters including RDX concentration and furnace temperature. The size of RDX crystals was reduced as RDX concentration decreased and furnace temperature increased. The formation of random-shaped RDX particles due to agglomeration could be explained by coalescence between a crystal-containing droplet and a crystal or a crystal-containing droplet. In the present work, agglomeration was found to be controlled with injection of additives into starting solution: polyvinylpyrrolidone (PVP), which acted as a strong nucleation inhibitor in the crystallization of RDX from acetone, was very effective on the formation of spherical RDX particles. However, when the nucleation promoters such as polyoxyethylene 10 oleoyl ether (Brij 97) and oleylamine were added, highly agglomerated and random-shaped RDX particles were produced. Therefore, it can be concluded that the controlling onset time of nucleation is an important factor to improve crystal shape in evaporation crystallization by ultrasonic spray. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697536
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12186-12193[article] Evaporation crystallization of RDX by ultrasonic spray [texte imprimé] / Jun-Woo Kim, Auteur ; Moon-Soo Shin, Auteur ; Jae-Kyeong Kim, Auteur . - 2011 . - pp. 12186-12193.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12186-12193
Mots-clés : Crystallization Evaporation Résumé : Cyclotrimethylene trinitramine (RDX) with size of 0.8 to 2.6 μm was produced by evaporation crystallization of RDX with ultrasonic spray. In the experimental range of the present work, the size of RDX crystals was found to be strongly affected by operating parameters including RDX concentration and furnace temperature. The size of RDX crystals was reduced as RDX concentration decreased and furnace temperature increased. The formation of random-shaped RDX particles due to agglomeration could be explained by coalescence between a crystal-containing droplet and a crystal or a crystal-containing droplet. In the present work, agglomeration was found to be controlled with injection of additives into starting solution: polyvinylpyrrolidone (PVP), which acted as a strong nucleation inhibitor in the crystallization of RDX from acetone, was very effective on the formation of spherical RDX particles. However, when the nucleation promoters such as polyoxyethylene 10 oleoyl ether (Brij 97) and oleylamine were added, highly agglomerated and random-shaped RDX particles were produced. Therefore, it can be concluded that the controlling onset time of nucleation is an important factor to improve crystal shape in evaporation crystallization by ultrasonic spray. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697536 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Thermodynamic modeling and gaseous pollution prediction of the yellow phosphorus production Type de document : texte imprimé Auteurs : Zhonghua Wang, Auteur ; Ming Jiang, Auteur ; Ping Ning, Auteur Année de publication : 2011 Article en page(s) : pp. 12194-12202 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Production Prediction Pollution Modeling Résumé : Thermodynamic modeling of the yellow phosphorus production is carried out to understand the producing mechanism of the tail gas, to predict its most probable composition, and to realize its deep purification and multipurpose utilization. The model is based on the typical raw materials composition and the common industrial process parameters of the electric furnace method, using FactSage6.1 and its database package. The predicted relative productivity between yellow phosphorus and byproduct is consistent with the reported values. Furthermore, the main composition of the tail gas can be obtained if kinetic inhibition is taken into account. The thus calculated equilibrium amounts of CO, H2S, and HF and the total amount of As are in good agreement with the results measured in the field, whereas those of PH3, COS, and CS2 are higher. This method of modeling can be used in the gaseous pollution prediction of other industrial chemical processes occurring at high temperatures. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697537
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12194-12202[article] Thermodynamic modeling and gaseous pollution prediction of the yellow phosphorus production [texte imprimé] / Zhonghua Wang, Auteur ; Ming Jiang, Auteur ; Ping Ning, Auteur . - 2011 . - pp. 12194-12202.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12194-12202
Mots-clés : Production Prediction Pollution Modeling Résumé : Thermodynamic modeling of the yellow phosphorus production is carried out to understand the producing mechanism of the tail gas, to predict its most probable composition, and to realize its deep purification and multipurpose utilization. The model is based on the typical raw materials composition and the common industrial process parameters of the electric furnace method, using FactSage6.1 and its database package. The predicted relative productivity between yellow phosphorus and byproduct is consistent with the reported values. Furthermore, the main composition of the tail gas can be obtained if kinetic inhibition is taken into account. The thus calculated equilibrium amounts of CO, H2S, and HF and the total amount of As are in good agreement with the results measured in the field, whereas those of PH3, COS, and CS2 are higher. This method of modeling can be used in the gaseous pollution prediction of other industrial chemical processes occurring at high temperatures. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697537 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Effect of electrolytes in aqueous solution on bubble size in gas – liquid bubble columns Type de document : texte imprimé Auteurs : José E. Botello-Álvarez, Auteur ; Sergio A. Baz-Rodríguez, Auteur ; Raúl González-García, Auteur Année de publication : 2011 Article en page(s) : pp. 12203-12207 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Bubble column Particle size Aqueous solution Electrolyte Résumé : The effects of three inorganic electrolytes (CaCl2, MgCl2, and NaCl) in aqueous solutions on the bubble size in a gas-liquid bubble column under a homogeneous bubbling regime were investigated. The concentration of electrolytes and the superficial gas velocity at the entrance of the column were varied. The average bubble diameter in the main section of the equipment was estimated using digital image analysis. From an analysis of variance, it was found that the electrolyte concentration is the main reason for bubble size variation. Moreover, it was found that the coalescent and noncoalescent behaviors in the bubble column are separated by the transition concentrations of coalescence. The ratio between the electrolyte concentrations and the transition concentration of coalescence (reduced concentration) was used to modify an empirical correlation that describes the experimental behavior of the Sauter mean diameter within an absolute percentage deviation of 10.47%. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697538
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12203-12207[article] Effect of electrolytes in aqueous solution on bubble size in gas – liquid bubble columns [texte imprimé] / José E. Botello-Álvarez, Auteur ; Sergio A. Baz-Rodríguez, Auteur ; Raúl González-García, Auteur . - 2011 . - pp. 12203-12207.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12203-12207
Mots-clés : Bubble column Particle size Aqueous solution Electrolyte Résumé : The effects of three inorganic electrolytes (CaCl2, MgCl2, and NaCl) in aqueous solutions on the bubble size in a gas-liquid bubble column under a homogeneous bubbling regime were investigated. The concentration of electrolytes and the superficial gas velocity at the entrance of the column were varied. The average bubble diameter in the main section of the equipment was estimated using digital image analysis. From an analysis of variance, it was found that the electrolyte concentration is the main reason for bubble size variation. Moreover, it was found that the coalescent and noncoalescent behaviors in the bubble column are separated by the transition concentrations of coalescence. The ratio between the electrolyte concentrations and the transition concentration of coalescence (reduced concentration) was used to modify an empirical correlation that describes the experimental behavior of the Sauter mean diameter within an absolute percentage deviation of 10.47%. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697538 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Distribution of Trace Elements from a Coal Burned in Two Different Spanish Power Stations Type de document : texte imprimé Auteurs : M. Antonia López-Antón, Auteur ; Mercedes Díaz-Somoano, Auteur ; Raquel Ochoa-González, Auteur Année de publication : 2011 Article en page(s) : pp. 12208-12216 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Coal Trace element Résumé : The behavior of trace elements during coal combustion varies, depending on their mode of occurrence in a given coal and the variations in the operational conditions in the power plants. However, the extent to which these variables may influence the behavior of trace elements is not yet clear. The objective of this study is to evaluate the influence of the operational conditions on the behavior of trace elements in two coal-fired power plants when the same coal supply is used. Fractions of the fly ash sampled from the hoppers of the electrostatic precipitators (ESPs) were studied and the relative enrichment (RE) factors of the elements were compared. Moreover, a series of leaching tests were carried out, with the objective of determining the level of risk when the wastes are finally disposed of. The behavior of the trace elements was found to be broadly similar. However, some differences were observed when evaluating their distribution among the different fly ash fractions from the ESPs. These differences are related to (i) the operational variables of the power plants and (ii) the performance of the mills. All of the coal combustion byproducts evaluated in this work may be considered as inert waste when they are disposed of. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697539
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12208-12216[article] Distribution of Trace Elements from a Coal Burned in Two Different Spanish Power Stations [texte imprimé] / M. Antonia López-Antón, Auteur ; Mercedes Díaz-Somoano, Auteur ; Raquel Ochoa-González, Auteur . - 2011 . - pp. 12208-12216.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12208-12216
Mots-clés : Coal Trace element Résumé : The behavior of trace elements during coal combustion varies, depending on their mode of occurrence in a given coal and the variations in the operational conditions in the power plants. However, the extent to which these variables may influence the behavior of trace elements is not yet clear. The objective of this study is to evaluate the influence of the operational conditions on the behavior of trace elements in two coal-fired power plants when the same coal supply is used. Fractions of the fly ash sampled from the hoppers of the electrostatic precipitators (ESPs) were studied and the relative enrichment (RE) factors of the elements were compared. Moreover, a series of leaching tests were carried out, with the objective of determining the level of risk when the wastes are finally disposed of. The behavior of the trace elements was found to be broadly similar. However, some differences were observed when evaluating their distribution among the different fly ash fractions from the ESPs. These differences are related to (i) the operational variables of the power plants and (ii) the performance of the mills. All of the coal combustion byproducts evaluated in this work may be considered as inert waste when they are disposed of. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697539 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Analysis of steam assisted gravity drainage produced water using two-dimensional gas chromatography with time - of - flight mass spectrometry Type de document : texte imprimé Auteurs : Matthew A. Petersen, Auteur ; Hans Grade, Auteur Année de publication : 2011 Article en page(s) : pp. 12217-12224 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Mass spectrometry Gas chromatography Water vapor Résumé : The recycling of water coproduced during in situ bitumen production is one of the primary operating challenges for steam assisted gravity drainage (SAGD) operations in oil sand reserves. Produced water that is either recycled for steam production or disposed of may be subject to different water quality requirements for the purposes of plant operations or environmental regulations. The organic components dissolved and suspended in the produced water are a fingerprint of the bitumen-in-place, the processing conditions utilized during production, and the chemicals used by operators during operations. Analysis of SAGD produced water using two-dimensional gas chromatography coupled with electron ionization and time-of-flight mass spectrometry (2DGC-TOFMS) showed a wide variety of organic constituents within the water sample. Compounds ranging from C6 to C18 straight chain and branched aliphatics to more polar, water-soluble, oxygen- and sulfur- heteroatomic species were tentatively identified. Methyl- and ethyl-phenols were prevalent constituents eluting in the heteroatomic region of the chromatographic contour plot. Sample extraction conditions that enhanced partitioning of polar organic species resulted in a significantly larger amount of compounds being detected by this approach. These results show how this method is complementary to more widely used analytical techniques, which cannot provide a comprehensive view of the broad range of compounds within oilfield produced water using a single method. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697540
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12217-12224[article] Analysis of steam assisted gravity drainage produced water using two-dimensional gas chromatography with time - of - flight mass spectrometry [texte imprimé] / Matthew A. Petersen, Auteur ; Hans Grade, Auteur . - 2011 . - pp. 12217-12224.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12217-12224
Mots-clés : Mass spectrometry Gas chromatography Water vapor Résumé : The recycling of water coproduced during in situ bitumen production is one of the primary operating challenges for steam assisted gravity drainage (SAGD) operations in oil sand reserves. Produced water that is either recycled for steam production or disposed of may be subject to different water quality requirements for the purposes of plant operations or environmental regulations. The organic components dissolved and suspended in the produced water are a fingerprint of the bitumen-in-place, the processing conditions utilized during production, and the chemicals used by operators during operations. Analysis of SAGD produced water using two-dimensional gas chromatography coupled with electron ionization and time-of-flight mass spectrometry (2DGC-TOFMS) showed a wide variety of organic constituents within the water sample. Compounds ranging from C6 to C18 straight chain and branched aliphatics to more polar, water-soluble, oxygen- and sulfur- heteroatomic species were tentatively identified. Methyl- and ethyl-phenols were prevalent constituents eluting in the heteroatomic region of the chromatographic contour plot. Sample extraction conditions that enhanced partitioning of polar organic species resulted in a significantly larger amount of compounds being detected by this approach. These results show how this method is complementary to more widely used analytical techniques, which cannot provide a comprehensive view of the broad range of compounds within oilfield produced water using a single method. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697540 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Electricity generation from wastewater using an anaerobic fluidized bed microbial fuel cell Type de document : texte imprimé Auteurs : Weifang Kong, Auteur ; Qingjie Guo, Auteur ; Xuyun Wang, Auteur Année de publication : 2011 Article en page(s) : pp. 12225-12232 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Fuel cell Fluidized bed Fluidization Anaerobe Waste water Résumé : The anaerobic fluidized bed microbial fuel cell (AFBMFC) was developed to generate electricity while simultaneously treating wastewater. During a complete cycle, the AFBMFC continuously generated electricity with a maximum power density of 1100 mW/m2 and removal of total chemical oxygen demand (COD) of 89%. To achieve this power density, the artificial electron-mediator neutral red (NR) was employed in the anode chamber. Granular biological electrodes, fluidization behavior, electron mediators, and temperature were evaluated to improve power production and wastewater treatment efficiency. The results showed that the maximum power density production of granule-graphite AFBMFC was 530 mW/m2, much higher than 410 mW/m2 using a granular activated carbon AFBMFC in the same reactor. Fluidization behaviors enhance the mass transfer and momentum transfer between activated carbon and wastewater. The power density increased with increasing methylene blue (MB) and NR concentration. Furthermore, power density reveals a slight increase as MB and NR concentrations exceed 0.5 and 1.7 mmol/L. The optimum temperature ranges from 23 to 40 °C. The Coulombic efficiency was 9.3% under the best operating conditions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697541
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12225-12232[article] Electricity generation from wastewater using an anaerobic fluidized bed microbial fuel cell [texte imprimé] / Weifang Kong, Auteur ; Qingjie Guo, Auteur ; Xuyun Wang, Auteur . - 2011 . - pp. 12225-12232.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12225-12232
Mots-clés : Fuel cell Fluidized bed Fluidization Anaerobe Waste water Résumé : The anaerobic fluidized bed microbial fuel cell (AFBMFC) was developed to generate electricity while simultaneously treating wastewater. During a complete cycle, the AFBMFC continuously generated electricity with a maximum power density of 1100 mW/m2 and removal of total chemical oxygen demand (COD) of 89%. To achieve this power density, the artificial electron-mediator neutral red (NR) was employed in the anode chamber. Granular biological electrodes, fluidization behavior, electron mediators, and temperature were evaluated to improve power production and wastewater treatment efficiency. The results showed that the maximum power density production of granule-graphite AFBMFC was 530 mW/m2, much higher than 410 mW/m2 using a granular activated carbon AFBMFC in the same reactor. Fluidization behaviors enhance the mass transfer and momentum transfer between activated carbon and wastewater. The power density increased with increasing methylene blue (MB) and NR concentration. Furthermore, power density reveals a slight increase as MB and NR concentrations exceed 0.5 and 1.7 mmol/L. The optimum temperature ranges from 23 to 40 °C. The Coulombic efficiency was 9.3% under the best operating conditions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697541 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Next - generation modeling of melt blowing Type de document : texte imprimé Auteurs : Brent R. Shambaugh, Auteur ; Dimitrios V. Papavassiliou, Auteur ; Robert L. Shambaugh, Auteur Année de publication : 2011 Article en page(s) : pp. 12233-12245 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Modeling Résumé : An advanced model has been developed for predicting the behavior of a fiber as it is formed in the melt blowing process. The model involves the simultaneous solution of the momentum, energy, and continuity equations. Crystallization effects are included. The model equations are solved numerically. As a bottom boundary condition in this solution, a "stop point" is assumed. The stop point is the point where (a) the fiber stress is zero, and (b) the air velocity and fiber velocity are equal. Predicted parameters include fiber diameter, velocity, temperature, stress, and crystallinity. The predicted results show that very little online crystallization takes place under typical melt blowing conditions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697542
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12233-12245[article] Next - generation modeling of melt blowing [texte imprimé] / Brent R. Shambaugh, Auteur ; Dimitrios V. Papavassiliou, Auteur ; Robert L. Shambaugh, Auteur . - 2011 . - pp. 12233-12245.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12233-12245
Mots-clés : Modeling Résumé : An advanced model has been developed for predicting the behavior of a fiber as it is formed in the melt blowing process. The model involves the simultaneous solution of the momentum, energy, and continuity equations. Crystallization effects are included. The model equations are solved numerically. As a bottom boundary condition in this solution, a "stop point" is assumed. The stop point is the point where (a) the fiber stress is zero, and (b) the air velocity and fiber velocity are equal. Predicted parameters include fiber diameter, velocity, temperature, stress, and crystallinity. The predicted results show that very little online crystallization takes place under typical melt blowing conditions. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697542 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Radical - mediated graft modification of polyethylene models with vinyltrimethoxysilane : a fundamental study Type de document : texte imprimé Auteurs : P. Pollet, Auteur ; C. L. Liotta, Auteur ; C. A. Eckert, Auteur Année de publication : 2011 Article en page(s) : pp. 12246-12253 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Modeling Résumé : Cross-linked polyethylenes have widespread applications such as insulators for current-carrying wires/cables and for hot water pipes. Industrially, cross-linked polyethylene can be prepared via the radical-initiated grafting of polyethylene with vinyltrimethoxysilane (VTMS) followed by moisture-induced cross-linking. The efficiency of the grafting reaction is not optimal: (1) a large portion of the VTMS remains unreacted and (2) controlling the distribution and extent of grafting is difficult. We present new contributions to the fundamental understanding of grafting reactions with VTMS on polymeric models (dodecane and heptane) as to the effect of phenyllithium capping reaction time on the analyses, the origin of the observation of multiple grafts, and the regiochemistry of the multiple graft products. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697543
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12246-12253[article] Radical - mediated graft modification of polyethylene models with vinyltrimethoxysilane : a fundamental study [texte imprimé] / P. Pollet, Auteur ; C. L. Liotta, Auteur ; C. A. Eckert, Auteur . - 2011 . - pp. 12246-12253.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12246-12253
Mots-clés : Modeling Résumé : Cross-linked polyethylenes have widespread applications such as insulators for current-carrying wires/cables and for hot water pipes. Industrially, cross-linked polyethylene can be prepared via the radical-initiated grafting of polyethylene with vinyltrimethoxysilane (VTMS) followed by moisture-induced cross-linking. The efficiency of the grafting reaction is not optimal: (1) a large portion of the VTMS remains unreacted and (2) controlling the distribution and extent of grafting is difficult. We present new contributions to the fundamental understanding of grafting reactions with VTMS on polymeric models (dodecane and heptane) as to the effect of phenyllithium capping reaction time on the analyses, the origin of the observation of multiple grafts, and the regiochemistry of the multiple graft products. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697543 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Vapor – liquid equilibrium measurements for the ternary systems of CO2 + n - hexane + n - decane and CO2 + n - octane + n - decane Type de document : texte imprimé Auteurs : Carmen Sánchez-García, Auteur ; Karla E. Vázquez-Hernández, Auteur ; Luis A. Galicia-Luna, Auteur Année de publication : 2011 Article en page(s) : pp. 12254-12258 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Carbon dioxide Ternary system Phase equilibrium Liquid vapor Résumé : The experimental vapor-liquid equilibrium (VLE) data for two ternary systems containing CO2 + n-alkane + n-decane were measured using an online static-analytic apparatus with a movable ROLSI sampler. The studied CO2 + n-hexane + n-decane and CO2 + n-octane + n-decane systems were measured at temperatures of (312.89, 342.50, and 376.20) K and (313.59, 344.28, and 373.49) K, respectively. The Peng-Robinson equation of state was used to predict the VLE data of the ternary systems from the temperature-independent interaction parameters of the binary systems. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697544
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12254-12258[article] Vapor – liquid equilibrium measurements for the ternary systems of CO2 + n - hexane + n - decane and CO2 + n - octane + n - decane [texte imprimé] / Carmen Sánchez-García, Auteur ; Karla E. Vázquez-Hernández, Auteur ; Luis A. Galicia-Luna, Auteur . - 2011 . - pp. 12254-12258.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12254-12258
Mots-clés : Carbon dioxide Ternary system Phase equilibrium Liquid vapor Résumé : The experimental vapor-liquid equilibrium (VLE) data for two ternary systems containing CO2 + n-alkane + n-decane were measured using an online static-analytic apparatus with a movable ROLSI sampler. The studied CO2 + n-hexane + n-decane and CO2 + n-octane + n-decane systems were measured at temperatures of (312.89, 342.50, and 376.20) K and (313.59, 344.28, and 373.49) K, respectively. The Peng-Robinson equation of state was used to predict the VLE data of the ternary systems from the temperature-independent interaction parameters of the binary systems. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697544 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Liquid – liquid equilibria in binary solutions formed by [Pyridinium - Derived] [F4B] ionic liquids and alkanols : new experimental data and validation of a multiparametric model for correlating LLE data Type de document : texte imprimé Auteurs : Fernando Espiau, Auteur ; Juan Ortega, Auteur ; Luís Fernández, Auteur Année de publication : 2011 Article en page(s) : pp. 12259-12270 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Modeling Ionic liquid Phase equilibrium Liquid Résumé : Experimental solubility data are presented for a set of binary systems composed of ionic liquids (IL) derived from pyridium, with the tetrafluoroborate anion, ana normal alcohols ranging from ethanol to decanol, in me temperature interval of 275-420 K, at atmospheric pressure. For each case, the miscibility curve and the upper critical solubility temperature (UCST) values are presented. The effects of the ILs on the behavior of solutions with alkanols are analyzed, paying special attention to the pyridine derivatives, and considering a series of structural characteristics of the compounds involved. Miscibility curves are modeled using, for the first time in a LLE study, an adimensional form of a semiempirical model proposed for the Gibbs excess function, GE = GE(p,Trx) [Ind. Eng. Chem. Res. 2010, 49, 406], whose particular form in this work is gE(T,x)=z(x)[1-z(x)] r∑i=0 gi(T)zi(x) The results are compared with those of an extended form of the Non-Random Two-Liquids (NRTL) equation, using temperature-dependent parameters. In both cases, a rigorous procedure is carried out to calculate the LLE data, considering the isoactivity criteria, and a global test to check the phase stability for the solutions studied. The final evaluation of the application with the new equation gave satisfactory results. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697545
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12259-12270[article] Liquid – liquid equilibria in binary solutions formed by [Pyridinium - Derived] [F4B] ionic liquids and alkanols : new experimental data and validation of a multiparametric model for correlating LLE data [texte imprimé] / Fernando Espiau, Auteur ; Juan Ortega, Auteur ; Luís Fernández, Auteur . - 2011 . - pp. 12259-12270.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12259-12270
Mots-clés : Modeling Ionic liquid Phase equilibrium Liquid Résumé : Experimental solubility data are presented for a set of binary systems composed of ionic liquids (IL) derived from pyridium, with the tetrafluoroborate anion, ana normal alcohols ranging from ethanol to decanol, in me temperature interval of 275-420 K, at atmospheric pressure. For each case, the miscibility curve and the upper critical solubility temperature (UCST) values are presented. The effects of the ILs on the behavior of solutions with alkanols are analyzed, paying special attention to the pyridine derivatives, and considering a series of structural characteristics of the compounds involved. Miscibility curves are modeled using, for the first time in a LLE study, an adimensional form of a semiempirical model proposed for the Gibbs excess function, GE = GE(p,Trx) [Ind. Eng. Chem. Res. 2010, 49, 406], whose particular form in this work is gE(T,x)=z(x)[1-z(x)] r∑i=0 gi(T)zi(x) The results are compared with those of an extended form of the Non-Random Two-Liquids (NRTL) equation, using temperature-dependent parameters. In both cases, a rigorous procedure is carried out to calculate the LLE data, considering the isoactivity criteria, and a global test to check the phase stability for the solutions studied. The final evaluation of the application with the new equation gave satisfactory results. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697545 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Environment - friendly bromination of aromatic heterocycles using a bromide – bromate couple in an aqueous medium Type de document : texte imprimé Auteurs : Girdhar Joshi, Auteur ; Subbarayappa Adimurthy, Auteur Année de publication : 2011 Article en page(s) : pp. 12271-12275 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Aqueous medium Bromination Résumé : Selective monobromination of aromatic heterocyclic compounds through in-situ acid activation of 2:1 bromide/ bromate couple as a benign brominating reagent is described. The in-situ acid activation of a bromide-bromate couple generates the reactive species BrOH, and it is proved to be an efficient for the bromination of various heterocycles under mild aqueous conditions without the use of any catalyst. Heterocycles that had electron-rich substituents provided good yields. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697546
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12271-12275[article] Environment - friendly bromination of aromatic heterocycles using a bromide – bromate couple in an aqueous medium [texte imprimé] / Girdhar Joshi, Auteur ; Subbarayappa Adimurthy, Auteur . - 2011 . - pp. 12271-12275.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12271-12275
Mots-clés : Aqueous medium Bromination Résumé : Selective monobromination of aromatic heterocyclic compounds through in-situ acid activation of 2:1 bromide/ bromate couple as a benign brominating reagent is described. The in-situ acid activation of a bromide-bromate couple generates the reactive species BrOH, and it is proved to be an efficient for the bromination of various heterocycles under mild aqueous conditions without the use of any catalyst. Heterocycles that had electron-rich substituents provided good yields. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697546 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Degradation of cellulose in dilute aqueous solutions of acidic ionic liquid 1 - (1 - Propylsulfonic) - 3 - methylimidazolium chloride, and p - toluenesulfonic acid at moderate temperatures and pressures Type de document : texte imprimé Auteurs : Ananda S. Amarasekara, Auteur ; Bernard Wiredu, Auteur Année de publication : 2011 Article en page(s) : pp. 12276-12280 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Ionic liquid Aqueous solution Résumé : Dilute aqueous solutions of 1-(1-propylsulfonic)-3-methylimidazolium chloride and p-toluenesulfonic acid are shown to be better catalysts than aqueous sulfuric acid of the same H+ ion concentration for the degradation of cellulose at moderate temperatures and pressures. For example, Sigmacell cellulose (DP ≈ 450) in aqueous solutions of 1-(1-propylsulfonic)-3-methylimidazolium chloride, p-toluenesulfonic acid, and sulfuric acid of the same acid strength (0.0321 mol H+ ion/L) produced total reducing sugar (TRS) yields of 28.5%, 32.6%, and 22.0%, respectively, after heating at 170 °C for 3.0 h. In the same set of experiments, glucose yields of 22.2%, 21.0%, and 16.2% were attained in 1-(1-propylsulfonic)-3-methylimidazolium chloride, p-toluenesulfonc acid, and sulfuric acid mediums, respectively. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697547
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12276-12280[article] Degradation of cellulose in dilute aqueous solutions of acidic ionic liquid 1 - (1 - Propylsulfonic) - 3 - methylimidazolium chloride, and p - toluenesulfonic acid at moderate temperatures and pressures [texte imprimé] / Ananda S. Amarasekara, Auteur ; Bernard Wiredu, Auteur . - 2011 . - pp. 12276-12280.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12276-12280
Mots-clés : Ionic liquid Aqueous solution Résumé : Dilute aqueous solutions of 1-(1-propylsulfonic)-3-methylimidazolium chloride and p-toluenesulfonic acid are shown to be better catalysts than aqueous sulfuric acid of the same H+ ion concentration for the degradation of cellulose at moderate temperatures and pressures. For example, Sigmacell cellulose (DP ≈ 450) in aqueous solutions of 1-(1-propylsulfonic)-3-methylimidazolium chloride, p-toluenesulfonic acid, and sulfuric acid of the same acid strength (0.0321 mol H+ ion/L) produced total reducing sugar (TRS) yields of 28.5%, 32.6%, and 22.0%, respectively, after heating at 170 °C for 3.0 h. In the same set of experiments, glucose yields of 22.2%, 21.0%, and 16.2% were attained in 1-(1-propylsulfonic)-3-methylimidazolium chloride, p-toluenesulfonc acid, and sulfuric acid mediums, respectively. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697547 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Fouling - free membranes obtained by facile surface modification of commercially available membranes using the dynamic forming method Type de document : texte imprimé Auteurs : Kazuki Akamatsu, Auteur ; Keita Mitsumori, Auteur ; Fang Han, Auteur Année de publication : 2011 Article en page(s) : pp. 12281-12284 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Fouling Résumé : The dynamic forming method was first employed for the preparation of fouling-free membranes. The copolymer of 1-carboxy-N,N-dimethyl-N-(2'-methacryloyloxyethyl) methanaminium inner salt and n-butyl methacrylate was selected for the surface modification polymer to realize the fouling-free property in this study, and its aqueous solution was filtered using a commercially available ultrafiltration membrane. The surface modification polymer was thus deposited on the ultrafiltration membrane in a facile manner over several minutes. Compared to the unmodified membrane, the dynamically formed membrane with the surface modification polymer layer proved to have excellent fouling resistance against 1000 ppm bovine serum albumin (BSA) solution. In particular, the dynamically formed membrane was hardly fouled and maintained its initial flux when the filtration flux was set below 6 × 10-6 m3 m-2 s-1. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697548
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12281-12284[article] Fouling - free membranes obtained by facile surface modification of commercially available membranes using the dynamic forming method [texte imprimé] / Kazuki Akamatsu, Auteur ; Keita Mitsumori, Auteur ; Fang Han, Auteur . - 2011 . - pp. 12281-12284.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12281-12284
Mots-clés : Fouling Résumé : The dynamic forming method was first employed for the preparation of fouling-free membranes. The copolymer of 1-carboxy-N,N-dimethyl-N-(2'-methacryloyloxyethyl) methanaminium inner salt and n-butyl methacrylate was selected for the surface modification polymer to realize the fouling-free property in this study, and its aqueous solution was filtered using a commercially available ultrafiltration membrane. The surface modification polymer was thus deposited on the ultrafiltration membrane in a facile manner over several minutes. Compared to the unmodified membrane, the dynamically formed membrane with the surface modification polymer layer proved to have excellent fouling resistance against 1000 ppm bovine serum albumin (BSA) solution. In particular, the dynamically formed membrane was hardly fouled and maintained its initial flux when the filtration flux was set below 6 × 10-6 m3 m-2 s-1. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697548 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Decontamination of chemical warfare agents using household chemicals Type de document : texte imprimé Auteurs : George Wayne Wagner, Auteur Année de publication : 2011 Article en page(s) : pp. 12285–12287 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Household chemicals Résumé : Chemical warfare agents (CWA) such as VX (a V-type nerve agent), GD (a G-type nerve agent), and HD (a blister agent) are readily decontaminated using common household chemicals, such as ammonia-based cleaners, hydrogen peroxide, baking soda, washing soda, and rubbing alcohol, thus providing safe, cost-effective decontamination capability that is accessible to the general public. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201297e
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12285–12287[article] Decontamination of chemical warfare agents using household chemicals [texte imprimé] / George Wayne Wagner, Auteur . - 2011 . - pp. 12285–12287.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12285–12287
Mots-clés : Household chemicals Résumé : Chemical warfare agents (CWA) such as VX (a V-type nerve agent), GD (a G-type nerve agent), and HD (a blister agent) are readily decontaminated using common household chemicals, such as ammonia-based cleaners, hydrogen peroxide, baking soda, washing soda, and rubbing alcohol, thus providing safe, cost-effective decontamination capability that is accessible to the general public. DEWEY : 660 ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie201297e Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : A highly active and robust solid - supported polypyridylruthenium(II) catalyst for the oxidation of alcohols and alkenes by cerium(IV) and periodate in water Type de document : texte imprimé Auteurs : Zongmin Hu, Auteur ; Hongxia Du, Auteur ; Chi-Fai Leung, Auteur Année de publication : 2011 Article en page(s) : pp. 12288-12292 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Oxidation Catalyst Résumé : The species cis-[RuII(2,9-Me2phen)2(OH2)2]2+, both in homogeneous solution and supported on Dowex cation-exchange resin, is a highly active and robust catalyst for the oxidation of alcohols and alkenes in water at room temperature, using Ce(IV) and IO4- as terminal oxidants, with a turnover number (TON) of >104. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697550
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12288-12292[article] A highly active and robust solid - supported polypyridylruthenium(II) catalyst for the oxidation of alcohols and alkenes by cerium(IV) and periodate in water [texte imprimé] / Zongmin Hu, Auteur ; Hongxia Du, Auteur ; Chi-Fai Leung, Auteur . - 2011 . - pp. 12288-12292.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12288-12292
Mots-clés : Oxidation Catalyst Résumé : The species cis-[RuII(2,9-Me2phen)2(OH2)2]2+, both in homogeneous solution and supported on Dowex cation-exchange resin, is a highly active and robust catalyst for the oxidation of alcohols and alkenes in water at room temperature, using Ce(IV) and IO4- as terminal oxidants, with a turnover number (TON) of >104. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697550 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Energy recovery from acid – base neutralization process through pH - sensitive polymeric ion exchangers Type de document : texte imprimé Auteurs : Sudipta Sarkar, Auteur ; Arup K. SenGupta, Auteur ; John E. Greenleaf, Auteur Année de publication : 2011 Article en page(s) : pp. 12293–12298 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Ion exchanger pH Neutralization Energy recovery Résumé : Globally speaking, waste acid neutralization is a widely used industrial pollution control process. In principle, acid-base neutralization is a thermodynamically favorable reaction that involves the association of hydrogen and hydroxyl ions to form neutral water molecules with the generation of a significant amount of thermal energy (ΔH = -55.84 kJ/mol). However, it is not possible to recover the energy, because the increase in temperature of the bulk solution phase is often miniscule, because of the diluted nature of the waste acid solution and the high specific heat of water. Here, we demonstrate a methodology to recover a significant amount of useful energy by carrying out the neutralization reaction inside a pH-sensitive hydrophilic polymer (or biopolymer) phase containing covalently attached weak-acid or weak-base functional groups. When contacted with an acid or a base, the variation ofpH causes the functional groups to reversibly acquire and lose its ionic character. This gives rise to an on-off pattern regarding the generation of osmotic pressure inside the polymer phase, causing it to reversibly swell and shrink, because of the movement of water into and out of the polymer phase. Laboratory experiments validate the reversibility of the swelling-shrinking pattern of a commercial weak-acid ion-exchange resin for multiple numbers of cycles with a concomitant generation of mechanical energy during the neutralization reaction. The process can be enhanced by tailoring the cross-linking and hydrophilicity of the polymer phase. The energy generated is free of carbon emission. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697551
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12293–12298[article] Energy recovery from acid – base neutralization process through pH - sensitive polymeric ion exchangers [texte imprimé] / Sudipta Sarkar, Auteur ; Arup K. SenGupta, Auteur ; John E. Greenleaf, Auteur . - 2011 . - pp. 12293–12298.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12293–12298
Mots-clés : Ion exchanger pH Neutralization Energy recovery Résumé : Globally speaking, waste acid neutralization is a widely used industrial pollution control process. In principle, acid-base neutralization is a thermodynamically favorable reaction that involves the association of hydrogen and hydroxyl ions to form neutral water molecules with the generation of a significant amount of thermal energy (ΔH = -55.84 kJ/mol). However, it is not possible to recover the energy, because the increase in temperature of the bulk solution phase is often miniscule, because of the diluted nature of the waste acid solution and the high specific heat of water. Here, we demonstrate a methodology to recover a significant amount of useful energy by carrying out the neutralization reaction inside a pH-sensitive hydrophilic polymer (or biopolymer) phase containing covalently attached weak-acid or weak-base functional groups. When contacted with an acid or a base, the variation ofpH causes the functional groups to reversibly acquire and lose its ionic character. This gives rise to an on-off pattern regarding the generation of osmotic pressure inside the polymer phase, causing it to reversibly swell and shrink, because of the movement of water into and out of the polymer phase. Laboratory experiments validate the reversibility of the swelling-shrinking pattern of a commercial weak-acid ion-exchange resin for multiple numbers of cycles with a concomitant generation of mechanical energy during the neutralization reaction. The process can be enhanced by tailoring the cross-linking and hydrophilicity of the polymer phase. The energy generated is free of carbon emission. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697551 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Effect of orotic acid on the crystallization kinetics and morphology of biodegradable poly (l-lactide) as an efficient nucleating agent Type de document : texte imprimé Auteurs : Zhaobin Qiu, Auteur ; Zhisheng Li, Auteur Année de publication : 2011 Article en page(s) : pp. 12299-12303 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Morphology Kinetics Crystallization Résumé : The wider practical application of biodegradable and biocompatible poly(L-lactic acid) (PLLA) has been restricted because of many disadvantages, especially its relatively slow crystallisation rate. In this note, a PLLA/orotic add (OA) composite was prepared via a simple melt compounding method. It is found that both the nonisothermal melt crystallization and overall isothermal melt crystallization kinetics of PLLA have been enhanced signifcantly in the composite, even at very low OA content, relative to that of neat PLLA, indicating that OA is an efficient muleating agent of PLLA for its wider practical application, especially as biomaterial. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697552
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12299-12303[article] Effect of orotic acid on the crystallization kinetics and morphology of biodegradable poly (l-lactide) as an efficient nucleating agent [texte imprimé] / Zhaobin Qiu, Auteur ; Zhisheng Li, Auteur . - 2011 . - pp. 12299-12303.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12299-12303
Mots-clés : Morphology Kinetics Crystallization Résumé : The wider practical application of biodegradable and biocompatible poly(L-lactic acid) (PLLA) has been restricted because of many disadvantages, especially its relatively slow crystallisation rate. In this note, a PLLA/orotic add (OA) composite was prepared via a simple melt compounding method. It is found that both the nonisothermal melt crystallization and overall isothermal melt crystallization kinetics of PLLA have been enhanced signifcantly in the composite, even at very low OA content, relative to that of neat PLLA, indicating that OA is an efficient muleating agent of PLLA for its wider practical application, especially as biomaterial. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697552 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
Titre : Modification of the stokes – einstein equation with a semiempirical microfriction factor for correlation of tracer diffusivities in organic solvents Type de document : texte imprimé Auteurs : Shaw H. Chen, Auteur ; Simon K.-H. Wei, Auteur Année de publication : 2011 Article en page(s) : pp. 12304-12310 Note générale : Chimie industrielle Langues : Anglais (eng) Mots-clés : Organic solvent Diffusion coefficient Tracers Correlation analysis Semiempirical method Résumé : Characterized by conceptual simplicity, a semiempirical formula based on the Stokes-Einstein equation and microfriction theory was constructed for correlating tracer diffusivities and, alternatively, for evaluating solute aggregation in organic solvents. For nonassociated systems, van der Waals radii determined by Bondi's method were adopted to establish a base equation for treating associated solvents and solute-solvent systems. Values of molecular association numbers for hydrogen-bonded solvents are in good agreement with those characterized by X-ray diffraction and near-infrared spectroscopy. The generalized equation incorporating independently evaluated solutes' solvation numbers and solvents' association numbers as needed is capable of predicting tracer diffusivities to within ±8% for nonassociated and associated solute-solvent systems without resorting to adjustable parameters. Overall, this new approach perfohttp://atcatalogue_2.enp.edu.dz/catalog.php?categ=serials&sub=analysis&action=analysis_form&bul_id=15683&analysis_id=0rms better than the widely used Wilke-Chang equation with a comparable level of simplicity, including delineating temperature dependencies from 298 to 473 K of tracer diffusivities of solute-solvent systems consisting of relatively compact molecules. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697553
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12304-12310[article] Modification of the stokes – einstein equation with a semiempirical microfriction factor for correlation of tracer diffusivities in organic solvents [texte imprimé] / Shaw H. Chen, Auteur ; Simon K.-H. Wei, Auteur . - 2011 . - pp. 12304-12310.
Chimie industrielle
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 50 N° 21 (Novembre 2011) . - pp. 12304-12310
Mots-clés : Organic solvent Diffusion coefficient Tracers Correlation analysis Semiempirical method Résumé : Characterized by conceptual simplicity, a semiempirical formula based on the Stokes-Einstein equation and microfriction theory was constructed for correlating tracer diffusivities and, alternatively, for evaluating solute aggregation in organic solvents. For nonassociated systems, van der Waals radii determined by Bondi's method were adopted to establish a base equation for treating associated solvents and solute-solvent systems. Values of molecular association numbers for hydrogen-bonded solvents are in good agreement with those characterized by X-ray diffraction and near-infrared spectroscopy. The generalized equation incorporating independently evaluated solutes' solvation numbers and solvents' association numbers as needed is capable of predicting tracer diffusivities to within ±8% for nonassociated and associated solute-solvent systems without resorting to adjustable parameters. Overall, this new approach perfohttp://atcatalogue_2.enp.edu.dz/catalog.php?categ=serials&sub=analysis&action=analysis_form&bul_id=15683&analysis_id=0rms better than the widely used Wilke-Chang equation with a comparable level of simplicity, including delineating temperature dependencies from 298 to 473 K of tracer diffusivities of solute-solvent systems consisting of relatively compact molecules. DEWEY : 660 ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=24697553 Exemplaires
Code-barres Cote Support Localisation Section Disponibilité aucun exemplaire
