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Vol. 51 N° 43 - Octobre 2012 [texte imprimé] . - 2013 . - p. 13869-14316 : ill. ; 28 cm. Chemical engineering Langues : Anglais (eng)
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Ajouter le résultat dans votre panierPreparation, characterization, and tribological evaluation of a calcium borate embedded in an oleic acid matrix / Sheng Han in Industrial & engineering chemistry research, Vol. 51 N° 43 (Octobre 2012)
Titre : Preparation, characterization, and tribological evaluation of a calcium borate embedded in an oleic acid matrix Type de document : texte imprimé Auteurs : Sheng Han, Auteur ; Sizhou Liu, Auteur ; Yuhong Wang, Auteur Année de publication : 2013 Article en page(s) : pp. 13869-13874 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Calcium borate Résumé : Calcium borate nanoparticles embedded in an oleic acid liquid matrix (CBNL) with high stability in base oil were synthesized as nanoparticle lubricant additives designed as potential solution to problems of insolubility and stable dispersity using the conventional preparation method. The microstructures of the as-synthesized samples were characterized by laser particle analysis, infrared spectra, and thermogravimetric analysis. The results indicated that, in CBNL, the composition of the nanosized calcium borate was 2CaO·B2O3·xH2O, and the average size of the calcium borate nanoparticles was about 18 nm. The tribological properties of CBNL as a lubricating oil additive were evaluated on a four-ball tribometer. CBNL exhibited excellent tribological capacities including load-carrying, friction-reducing, and antiwear properties. The worn surface of the steel ball was investigated by a three-dimensional noncontact surface profile meter and X-ray photoelectron spectroscopy. The tribological mechanism of the nanoparticles was discussed. The excellent tribological properties exhibited by the as-synthesized sample resulted from a wear-resistant film containing both depositions and the tribochemical reaction products that comprise B2O3, FeB, and Fe2O3. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300940r
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13869-13874[article] Preparation, characterization, and tribological evaluation of a calcium borate embedded in an oleic acid matrix [texte imprimé] / Sheng Han, Auteur ; Sizhou Liu, Auteur ; Yuhong Wang, Auteur . - 2013 . - pp. 13869-13874.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13869-13874
Mots-clés : Calcium borate Résumé : Calcium borate nanoparticles embedded in an oleic acid liquid matrix (CBNL) with high stability in base oil were synthesized as nanoparticle lubricant additives designed as potential solution to problems of insolubility and stable dispersity using the conventional preparation method. The microstructures of the as-synthesized samples were characterized by laser particle analysis, infrared spectra, and thermogravimetric analysis. The results indicated that, in CBNL, the composition of the nanosized calcium borate was 2CaO·B2O3·xH2O, and the average size of the calcium borate nanoparticles was about 18 nm. The tribological properties of CBNL as a lubricating oil additive were evaluated on a four-ball tribometer. CBNL exhibited excellent tribological capacities including load-carrying, friction-reducing, and antiwear properties. The worn surface of the steel ball was investigated by a three-dimensional noncontact surface profile meter and X-ray photoelectron spectroscopy. The tribological mechanism of the nanoparticles was discussed. The excellent tribological properties exhibited by the as-synthesized sample resulted from a wear-resistant film containing both depositions and the tribochemical reaction products that comprise B2O3, FeB, and Fe2O3. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300940r Exemplaires
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Titre : Aggregation-resistant superparamagnetic noncovalent hybrid multilayer hollow microcapsules in high ionic strength media Type de document : texte imprimé Auteurs : Peng Liu, Auteur ; Xiaorui Li, Auteur ; Bin Mu, Auteur Année de publication : 2013 Article en page(s) : pp. 13875-13881 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Ionic strength Microcapsule Multiple layer Aggregation Résumé : In order to avoid the aggregation and/or fusion of the polyelectrolyte multilayer hollow microcapsules self-assembled via the noncovalent bonds, superparamagnetic polyelectrolyte hybrid hollow microcapsules surface-modified with polyethylene glycol (PEG) brushes were designed and fabricated. After the layer-by-layer (LbL) self-assembly of chitosan (CS) and citric acid-modified magnetic nanoparticles (Fe3O4―CA) as the polycation and the hybrid anion on the polystyrene sulfonate microsphere (PSS) templates, respectively, the aldehyde group terminated polyethylene glycol-4000 (APEG) was grafted onto the surface of the superparamagnetic polyelectrolyte hybrid multilayer coated template microspheres via the nucleophilic addition between the aldehyde groups of APEG and the amino groups of CS. Then, the modified superparamagnetic polyelectrolyte hybrid hollow microcapsules were obtained after the templates were removed by dialysis. It was found that the surface PEGylation could prevent aggregation among the hollow microcapsules in the media with high salt concentration by dynamic light scattering (DLS), besides the increase in biocompatibility. The technique developed is expected to realize the application of the polyelectrolyte multilayer hollow microcapsules in real physiological environments. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593312
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13875-13881[article] Aggregation-resistant superparamagnetic noncovalent hybrid multilayer hollow microcapsules in high ionic strength media [texte imprimé] / Peng Liu, Auteur ; Xiaorui Li, Auteur ; Bin Mu, Auteur . - 2013 . - pp. 13875-13881.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13875-13881
Mots-clés : Ionic strength Microcapsule Multiple layer Aggregation Résumé : In order to avoid the aggregation and/or fusion of the polyelectrolyte multilayer hollow microcapsules self-assembled via the noncovalent bonds, superparamagnetic polyelectrolyte hybrid hollow microcapsules surface-modified with polyethylene glycol (PEG) brushes were designed and fabricated. After the layer-by-layer (LbL) self-assembly of chitosan (CS) and citric acid-modified magnetic nanoparticles (Fe3O4―CA) as the polycation and the hybrid anion on the polystyrene sulfonate microsphere (PSS) templates, respectively, the aldehyde group terminated polyethylene glycol-4000 (APEG) was grafted onto the surface of the superparamagnetic polyelectrolyte hybrid multilayer coated template microspheres via the nucleophilic addition between the aldehyde groups of APEG and the amino groups of CS. Then, the modified superparamagnetic polyelectrolyte hybrid hollow microcapsules were obtained after the templates were removed by dialysis. It was found that the surface PEGylation could prevent aggregation among the hollow microcapsules in the media with high salt concentration by dynamic light scattering (DLS), besides the increase in biocompatibility. The technique developed is expected to realize the application of the polyelectrolyte multilayer hollow microcapsules in real physiological environments. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593312 Exemplaires
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Titre : Absorption properties and spectroscopic studies of dilute sulfur dioxide in aqueous glycerol solutions Type de document : texte imprimé Auteurs : Zhiqiang He, Auteur ; Jinrong Liu, Auteur ; Lijun Li, Auteur Année de publication : 2013 Article en page(s) : pp. 13882–13890 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Spectroscopic Dioxide Résumé : Isothermal gas–liquid equilibrium (GLE) data were reported at 298.15 K and 123.15 kPa for the absorption of dilute SO2 in aqueous glycerol solutions, in which SO2 partial pressures are calculated in the range of (0 to 140) Pa. The GLE data were obtained with uncertainties within ±0.02 K for temperatures, ± 0.133 kPa for total pressures, ± 3.5% for SO2 concentration in the gas phase, and ±5% for SO2 concentration in the liquid phase. The measurements showed that the solubility of dilute SO2 in the system of glycerol (1) + water (2) increases with the increasing glycerol concentrations in the whole composition, and the solubility of SO2 in the system of glycerol (1) + water (2) presents an extreme minimum of 60.1 mg·L–1 at the mass fraction of w1 = 1.00 when SO2 in the gas phase is designed at ySO2 = 5 × 10–4. In addition, UV, FTIR (Fourier transform infrared), 1H NMR, and fluorescence spectra in the absorption processes of SO2 in the system of glycerol (1) + water (2) were investigated to present important absorption mechanism. Based on the spectral results obtained, the possibility of intermolecular hydrogen bond formation by hydroxyl oxygen atoms in the glycerol molecule with hydrogen atom in the H2O molecule and S···O interaction formation by hydroxyl oxygen atom in the glycerol molecule with sulfur atom in the SO2 molecule are discussed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3016158
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13882–13890[article] Absorption properties and spectroscopic studies of dilute sulfur dioxide in aqueous glycerol solutions [texte imprimé] / Zhiqiang He, Auteur ; Jinrong Liu, Auteur ; Lijun Li, Auteur . - 2013 . - pp. 13882–13890.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13882–13890
Mots-clés : Spectroscopic Dioxide Résumé : Isothermal gas–liquid equilibrium (GLE) data were reported at 298.15 K and 123.15 kPa for the absorption of dilute SO2 in aqueous glycerol solutions, in which SO2 partial pressures are calculated in the range of (0 to 140) Pa. The GLE data were obtained with uncertainties within ±0.02 K for temperatures, ± 0.133 kPa for total pressures, ± 3.5% for SO2 concentration in the gas phase, and ±5% for SO2 concentration in the liquid phase. The measurements showed that the solubility of dilute SO2 in the system of glycerol (1) + water (2) increases with the increasing glycerol concentrations in the whole composition, and the solubility of SO2 in the system of glycerol (1) + water (2) presents an extreme minimum of 60.1 mg·L–1 at the mass fraction of w1 = 1.00 when SO2 in the gas phase is designed at ySO2 = 5 × 10–4. In addition, UV, FTIR (Fourier transform infrared), 1H NMR, and fluorescence spectra in the absorption processes of SO2 in the system of glycerol (1) + water (2) were investigated to present important absorption mechanism. Based on the spectral results obtained, the possibility of intermolecular hydrogen bond formation by hydroxyl oxygen atoms in the glycerol molecule with hydrogen atom in the H2O molecule and S···O interaction formation by hydroxyl oxygen atom in the glycerol molecule with sulfur atom in the SO2 molecule are discussed. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3016158 Exemplaires
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Titre : Acidic and catalytic properties of modified clay for removing trace olefin from aromatics and its industrial test Type de document : texte imprimé Auteurs : Xin Pu, Auteur ; Nai-wang Liu, Auteur ; Zheng-hong Jiang, Auteur Année de publication : 2013 Article en page(s) : pp. 13891-13896 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Catalytic reaction Résumé : The commercial clay modified with zeolite and La2O3 was characterized by thermoprogrammed desorption (t.p.d.) of NH, and pyridine adsorption followed by Fourier transform infrared spectroscopy (FTIR). The result showed that the weak Lewis acid plays an important role in the alkylation reaction between olefin and aromatics which obeyed the carbonium ion mechanism. The industrial test was conducted in the 450kt/a industrial PX device at Sinopec Zhenhai Company for removing trace olefins from aromatics: It has been proved that the life cycle of the catalyst was 5.3 times that of the commercial clay. The kinetics formula for deactivation rates was explored and the result showed that the rate of clay was much higher than the catalyst deactivation rate. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593314
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13891-13896[article] Acidic and catalytic properties of modified clay for removing trace olefin from aromatics and its industrial test [texte imprimé] / Xin Pu, Auteur ; Nai-wang Liu, Auteur ; Zheng-hong Jiang, Auteur . - 2013 . - pp. 13891-13896.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13891-13896
Mots-clés : Catalytic reaction Résumé : The commercial clay modified with zeolite and La2O3 was characterized by thermoprogrammed desorption (t.p.d.) of NH, and pyridine adsorption followed by Fourier transform infrared spectroscopy (FTIR). The result showed that the weak Lewis acid plays an important role in the alkylation reaction between olefin and aromatics which obeyed the carbonium ion mechanism. The industrial test was conducted in the 450kt/a industrial PX device at Sinopec Zhenhai Company for removing trace olefins from aromatics: It has been proved that the life cycle of the catalyst was 5.3 times that of the commercial clay. The kinetics formula for deactivation rates was explored and the result showed that the rate of clay was much higher than the catalyst deactivation rate. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593314 Exemplaires
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Titre : Predicting the toxicity of ionic liquids in leukemia rat cell line by the quantitative structure–activity relationship method using topological indexes Type de document : texte imprimé Auteurs : Fangyou Yan, Auteur ; Shuqian Xia, Auteur ; Qiang Wang, Auteur Année de publication : 2013 Article en page(s) : pp. 13897-13901 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Property structure relationship Ionic liquid ToxicityPrediction Résumé : On the basis of the new topological index (TI) proposed in our previous work, a multiple linear regression (MLR) model was developed for predicting the toxicity of ionic liquids (ILs) in Leukemia Rat Cell Line (log EC50 IPC-81). The TI is derived from atom characters (e.g., atom radius, atom electronegativity, etc.) and atom position in the hydrogen-suppressed molecule structure. Because ILs are composed entirely of cations and anions, the TIs are calculated from cation and anion, respectively. A third TI was also proposed to depict the interaction of anion and cation. The toxicity of 173 ILs, which are based on imidazolium (Lm), pyridinium (Py), pyrrolidinium (Pyr), ammonium (Am), phosphonium (Ph), quinolinium (Qu), piperidinium (Pi), and morpholinium (Mo), was calculated by the model. The regression coefficient (R2) and the overall average absolute error (AAE) are 0.938 and 0.226, respectively. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593315
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13897-13901[article] Predicting the toxicity of ionic liquids in leukemia rat cell line by the quantitative structure–activity relationship method using topological indexes [texte imprimé] / Fangyou Yan, Auteur ; Shuqian Xia, Auteur ; Qiang Wang, Auteur . - 2013 . - pp. 13897-13901.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13897-13901
Mots-clés : Property structure relationship Ionic liquid ToxicityPrediction Résumé : On the basis of the new topological index (TI) proposed in our previous work, a multiple linear regression (MLR) model was developed for predicting the toxicity of ionic liquids (ILs) in Leukemia Rat Cell Line (log EC50 IPC-81). The TI is derived from atom characters (e.g., atom radius, atom electronegativity, etc.) and atom position in the hydrogen-suppressed molecule structure. Because ILs are composed entirely of cations and anions, the TIs are calculated from cation and anion, respectively. A third TI was also proposed to depict the interaction of anion and cation. The toxicity of 173 ILs, which are based on imidazolium (Lm), pyridinium (Py), pyrrolidinium (Pyr), ammonium (Am), phosphonium (Ph), quinolinium (Qu), piperidinium (Pi), and morpholinium (Mo), was calculated by the model. The regression coefficient (R2) and the overall average absolute error (AAE) are 0.938 and 0.226, respectively. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593315 Exemplaires
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Titre : Acid hydrolysis of prehydrolysis liquor produced from the kraft-based dissolving pulp production process Type de document : texte imprimé Auteurs : Guihua Yang, Auteur ; M. Sarwar Jahan, Auteur ; Haitang Liu, Auteur Année de publication : 2013 Article en page(s) : pp. 13902-13907 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Manufacturing process Hydrolysis Résumé : Acid hydrolysis is an essential step in converting polysaccharides to monosaccharides for the production of fuels and chemicals. The prehydrolysis liquor (PHL) from the kraft-based dissolving pulp production process contains mainly oligosugars with a minor amount of monosugars. In this study, the influence of process conditions, including the sulfuric acid concentration, temperature, and time on the PHL hydrolysis was thoroughly investigated in order to get maximum monosugar concentration with minimal degradation of sugars. The maximum monosugar concentration was obtained at 130 °C for 20 min when the hydrolysis was carried out with 1.78% H2SO4. A high acid concentration (3.33%) increased furfural formation and decreased the monosugar concentration. Acetic acid is generated from the acetyl groups bound to the dissolved hemicelluloses, resulting in a significant increase in the acetic acid concentration in the PHL. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593316
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13902-13907[article] Acid hydrolysis of prehydrolysis liquor produced from the kraft-based dissolving pulp production process [texte imprimé] / Guihua Yang, Auteur ; M. Sarwar Jahan, Auteur ; Haitang Liu, Auteur . - 2013 . - pp. 13902-13907.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13902-13907
Mots-clés : Manufacturing process Hydrolysis Résumé : Acid hydrolysis is an essential step in converting polysaccharides to monosaccharides for the production of fuels and chemicals. The prehydrolysis liquor (PHL) from the kraft-based dissolving pulp production process contains mainly oligosugars with a minor amount of monosugars. In this study, the influence of process conditions, including the sulfuric acid concentration, temperature, and time on the PHL hydrolysis was thoroughly investigated in order to get maximum monosugar concentration with minimal degradation of sugars. The maximum monosugar concentration was obtained at 130 °C for 20 min when the hydrolysis was carried out with 1.78% H2SO4. A high acid concentration (3.33%) increased furfural formation and decreased the monosugar concentration. Acetic acid is generated from the acetyl groups bound to the dissolved hemicelluloses, resulting in a significant increase in the acetic acid concentration in the PHL. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593316 Exemplaires
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Titre : The Kinetics of the incorporation of metals into tetraphenylporphyrin with metal salts in high-temperature water Type de document : texte imprimé Auteurs : Takafumi Sato, Auteur ; Katsutoshi Ebisawa, Auteur ; Kiwamu Sue, Auteur Année de publication : 2013 Article en page(s) : pp. 13908–13914 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Kinetics Metal salts Résumé : The incorporation of cobalt, nickel, copper, and oxovanadium(IV) into nonpolar 5,10,15,20-tetraphenyl-21H,23H-porphyrin (H2TPP) occurred with their sulfates, nitrates, and chlorides in high-temperature water. The yield of metalloporphyrin significantly increased with increasing temperature for cobalt, nickel, and copper sulfates from 473 to 673 K, which means that the high temperature region was preferred for the incorporation of metals into the porphyrin structure. In high-temperature water, most of H2TPP dissolved, whereas almost all of metals probably existed in solid phase. The incorporation of metal into a porphyrin structure was almost first-order with respect to H2TPP and probably proceeded through the pre-equilibrium state between metal ion and H2TPP. ISSN : 0888-5885
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13908–13914[article] The Kinetics of the incorporation of metals into tetraphenylporphyrin with metal salts in high-temperature water [texte imprimé] / Takafumi Sato, Auteur ; Katsutoshi Ebisawa, Auteur ; Kiwamu Sue, Auteur . - 2013 . - pp. 13908–13914.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13908–13914
Mots-clés : Kinetics Metal salts Résumé : The incorporation of cobalt, nickel, copper, and oxovanadium(IV) into nonpolar 5,10,15,20-tetraphenyl-21H,23H-porphyrin (H2TPP) occurred with their sulfates, nitrates, and chlorides in high-temperature water. The yield of metalloporphyrin significantly increased with increasing temperature for cobalt, nickel, and copper sulfates from 473 to 673 K, which means that the high temperature region was preferred for the incorporation of metals into the porphyrin structure. In high-temperature water, most of H2TPP dissolved, whereas almost all of metals probably existed in solid phase. The incorporation of metal into a porphyrin structure was almost first-order with respect to H2TPP and probably proceeded through the pre-equilibrium state between metal ion and H2TPP. ISSN : 0888-5885 Exemplaires
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Titre : Production of light olefins from polyethylene in a two-step process : Pyrolysis in a conical spouted bed and downstream high-temperature thermal cracking Type de document : texte imprimé Auteurs : Maite Artetxe, Auteur ; Gartzen Lopez, Auteur ; Gorka Elordi, Auteur Année de publication : 2013 Article en page(s) : pp. 13915-13923 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Thermal cracking Fluidization Spouted bed Pyrolysis Production Résumé : A two-step process has been used for the selective production of light olefins by the thermal cracking of high-density polyethylene. The plastic has been continuously fed into a conical spouted-bed reactor (CSBR) operating at 500 °C, which yields 93 wt % of waxes (C21+) and C12―C21 hydrocarbons. The volatile product stream has been cracked downstream in a multitubular (quartz tubes) reactor in the 800-950 °C range, with short residence times (0.016―0.032 s). A yield of 77 wt % of light olefins (C2―C4) has been obtained by operating at 900 °C in the second step. The maximum yields of ethylene, propylene, and butenes are 40.4, 19.5, and 17.5 wt %, respectively. Given the short residence time of the products in the reactor, the yield of aromatics is only 6.2 wt %. The high light olefin yield is due to the excellent performance of both steps. The CSBR allows maximizing the yield of waxes and avoiding defluidization problems. The operating conditions in the multitubular reactor (low concentration of the compounds in the volatile stream and short volatile residence times) are suitable for minimizing secondary reactions. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593318
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13915-13923[article] Production of light olefins from polyethylene in a two-step process : Pyrolysis in a conical spouted bed and downstream high-temperature thermal cracking [texte imprimé] / Maite Artetxe, Auteur ; Gartzen Lopez, Auteur ; Gorka Elordi, Auteur . - 2013 . - pp. 13915-13923.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13915-13923
Mots-clés : Thermal cracking Fluidization Spouted bed Pyrolysis Production Résumé : A two-step process has been used for the selective production of light olefins by the thermal cracking of high-density polyethylene. The plastic has been continuously fed into a conical spouted-bed reactor (CSBR) operating at 500 °C, which yields 93 wt % of waxes (C21+) and C12―C21 hydrocarbons. The volatile product stream has been cracked downstream in a multitubular (quartz tubes) reactor in the 800-950 °C range, with short residence times (0.016―0.032 s). A yield of 77 wt % of light olefins (C2―C4) has been obtained by operating at 900 °C in the second step. The maximum yields of ethylene, propylene, and butenes are 40.4, 19.5, and 17.5 wt %, respectively. Given the short residence time of the products in the reactor, the yield of aromatics is only 6.2 wt %. The high light olefin yield is due to the excellent performance of both steps. The CSBR allows maximizing the yield of waxes and avoiding defluidization problems. The operating conditions in the multitubular reactor (low concentration of the compounds in the volatile stream and short volatile residence times) are suitable for minimizing secondary reactions. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593318 Exemplaires
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Titre : Evaluation of CuAl2O4 as an oxygen carrier in chemical-looping combustion Type de document : texte imprimé Auteurs : Mehdi Arjmand, Auteur ; Abdul-Majeed Azad, Auteur ; Henrik Leion, Auteur Année de publication : 2013 Article en page(s) : pp. 13924–13934 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Chemical looping combustion Résumé : The chemical-looping combustion (CLC) process is a novel solution for efficient combustion with intrinsic separation of carbon dioxide. The process uses a metal oxide as an oxygen carrier to transfer oxygen from an air to a fuel reactor where the fuel, or gasification products of the fuel, reacts with the solid oxygen carrier. In this work, copper(II) aluminate (CuAl2O4) was assessed as a potential oxygen carrier using methane as fuel. The carrier particles were produced by freeze–granulation and calcined at 1050 °C for a duration of 6 h. The chemical-looping characteristics were evaluated in a laboratory-scale fluidized-bed reactor in the temperature range of 900–950 °C during 45 alternating redox cycles. The oxygen carrier exhibited reproducible and stable reactivity behavior in this temperature range. Neither agglomeration nor defluidization was noticed in any of the cycles carried out at 900–925 °C. However, after reactivity tests at 950 °C, soft agglomeration and particle fragmentation were observed. Systematic phase analysis of the Cu–Al–O system during the redox cycle was carried out as a function of duration of reduction and oxygen concentration during the oxidation period. It was found that the CuAl2O4 is reduced to copper(I) aluminate (CuAlO2; delafossite), Cu2O, and elemental Cu. The CuAlO2 phase is characterized by slow kinetics for oxidation into CuO and CuAl2O4. Despite this kinetic limitation, complete conversion of methane with reproducible reactivity of the oxygen carrier is achieved. Thus, CuAl2O4 could be a potential oxygen carrier for chemical-looping combustion. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300427w
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13924–13934[article] Evaluation of CuAl2O4 as an oxygen carrier in chemical-looping combustion [texte imprimé] / Mehdi Arjmand, Auteur ; Abdul-Majeed Azad, Auteur ; Henrik Leion, Auteur . - 2013 . - pp. 13924–13934.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13924–13934
Mots-clés : Chemical looping combustion Résumé : The chemical-looping combustion (CLC) process is a novel solution for efficient combustion with intrinsic separation of carbon dioxide. The process uses a metal oxide as an oxygen carrier to transfer oxygen from an air to a fuel reactor where the fuel, or gasification products of the fuel, reacts with the solid oxygen carrier. In this work, copper(II) aluminate (CuAl2O4) was assessed as a potential oxygen carrier using methane as fuel. The carrier particles were produced by freeze–granulation and calcined at 1050 °C for a duration of 6 h. The chemical-looping characteristics were evaluated in a laboratory-scale fluidized-bed reactor in the temperature range of 900–950 °C during 45 alternating redox cycles. The oxygen carrier exhibited reproducible and stable reactivity behavior in this temperature range. Neither agglomeration nor defluidization was noticed in any of the cycles carried out at 900–925 °C. However, after reactivity tests at 950 °C, soft agglomeration and particle fragmentation were observed. Systematic phase analysis of the Cu–Al–O system during the redox cycle was carried out as a function of duration of reduction and oxygen concentration during the oxidation period. It was found that the CuAl2O4 is reduced to copper(I) aluminate (CuAlO2; delafossite), Cu2O, and elemental Cu. The CuAlO2 phase is characterized by slow kinetics for oxidation into CuO and CuAl2O4. Despite this kinetic limitation, complete conversion of methane with reproducible reactivity of the oxygen carrier is achieved. Thus, CuAl2O4 could be a potential oxygen carrier for chemical-looping combustion. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300427w Exemplaires
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Titre : Hydrogenation of dimethyl oxalate using extruded Cu/SiO2 catalysts : Mechanical strength and catalytic performance Type de document : texte imprimé Auteurs : Li Zhao, Auteur ; Yujun Zhao, Auteur ; Shengping Wang, Auteur Année de publication : 2013 Article en page(s) : pp. 13935-13943 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Catalytic reaction Strength Catalyst Hydrogenation Résumé : In this work, the extrusion process of Cu/SiO2 catalysts prepared by the ammonia-evaporation (AE) method has been investigated and optimized in order to obtain materials with convenient catalytic and mechanical properties for their application in the gas-phase hydrogenation reaction of dimethyl oxalate (DMO) to ethylene glycol (EG). Thereby, a variety of Cu/SiO2 extrudates were prepared with different Cu loading, It has been observed that a special microstructure including defects, flaws, and discontinuities plays a significant role on the mechanical strength. Larger CuO grains may act as fracture origins, which negatively affect the mechanical strength. The 20Cu/SiO2 extrudate with high Cu dispersion and high porosity is optimized for hydrogenation of DMO to EG, achieving a 98% conversion of DMO and 85% selectivity of EG under the liquid hourly space velocity (LHSV) of 1.0 h―1. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593320
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13935-13943[article] Hydrogenation of dimethyl oxalate using extruded Cu/SiO2 catalysts : Mechanical strength and catalytic performance [texte imprimé] / Li Zhao, Auteur ; Yujun Zhao, Auteur ; Shengping Wang, Auteur . - 2013 . - pp. 13935-13943.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13935-13943
Mots-clés : Catalytic reaction Strength Catalyst Hydrogenation Résumé : In this work, the extrusion process of Cu/SiO2 catalysts prepared by the ammonia-evaporation (AE) method has been investigated and optimized in order to obtain materials with convenient catalytic and mechanical properties for their application in the gas-phase hydrogenation reaction of dimethyl oxalate (DMO) to ethylene glycol (EG). Thereby, a variety of Cu/SiO2 extrudates were prepared with different Cu loading, It has been observed that a special microstructure including defects, flaws, and discontinuities plays a significant role on the mechanical strength. Larger CuO grains may act as fracture origins, which negatively affect the mechanical strength. The 20Cu/SiO2 extrudate with high Cu dispersion and high porosity is optimized for hydrogenation of DMO to EG, achieving a 98% conversion of DMO and 85% selectivity of EG under the liquid hourly space velocity (LHSV) of 1.0 h―1. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593320 Exemplaires
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Titre : CFD analysis of flow patterns and micromixing efficiency in a Y-type microchannel reactor Type de document : texte imprimé Auteurs : Xin Shi, Auteur ; Yang Xiang, Auteur ; Li-Xiong Wen, Auteur Année de publication : 2013 Article en page(s) : pp. 13944-13952 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Microreactor Micromixing Flow field Computational fluid dynamics Résumé : Micromixing efficiency is a significant performance index of most chemical reactors. In this work, a three-dimensional Computational Fluid Dynamics (CFD) model for a Y-type microchannel reactor has been developed to predict its flow patterns and micromixing efficiency with the iodate-iodide reaction testing system. The effects of Re, volumetric flow ratio (R), and initial concentration of H+ on the micromixing efficiency (represented by the segregation index XS) have been investigated and the visualization of velocity, path lines, and concentration distributions inside the reactor has been demonstrated. It was found that XS decreases with increasing Re, or decreasing R or initial H― concentration. To optimize the microchannel reactor for enhanced mixing performance, the effects of microchannel configuration, such as length of channel, mixing angle, and hydraulic diameters, on micromixing efficiency were studied as well. The results demonstrated that the mixing process mainly occurs in the Y-junction area and extra length of outlet channel has little effect on micromixing efficiency. It also showed that XS depends strongly on the mixing angle and hydraulic diameters of the channels, and the pressure drop within the channel increases significantly with decreasing hydraulic diameters. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593321
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13944-13952[article] CFD analysis of flow patterns and micromixing efficiency in a Y-type microchannel reactor [texte imprimé] / Xin Shi, Auteur ; Yang Xiang, Auteur ; Li-Xiong Wen, Auteur . - 2013 . - pp. 13944-13952.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13944-13952
Mots-clés : Microreactor Micromixing Flow field Computational fluid dynamics Résumé : Micromixing efficiency is a significant performance index of most chemical reactors. In this work, a three-dimensional Computational Fluid Dynamics (CFD) model for a Y-type microchannel reactor has been developed to predict its flow patterns and micromixing efficiency with the iodate-iodide reaction testing system. The effects of Re, volumetric flow ratio (R), and initial concentration of H+ on the micromixing efficiency (represented by the segregation index XS) have been investigated and the visualization of velocity, path lines, and concentration distributions inside the reactor has been demonstrated. It was found that XS decreases with increasing Re, or decreasing R or initial H― concentration. To optimize the microchannel reactor for enhanced mixing performance, the effects of microchannel configuration, such as length of channel, mixing angle, and hydraulic diameters, on micromixing efficiency were studied as well. The results demonstrated that the mixing process mainly occurs in the Y-junction area and extra length of outlet channel has little effect on micromixing efficiency. It also showed that XS depends strongly on the mixing angle and hydraulic diameters of the channels, and the pressure drop within the channel increases significantly with decreasing hydraulic diameters. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593321 Exemplaires
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Titre : Role of support in hydrotreatment of jatropha oil over sulfided NiMo catalysts Type de document : texte imprimé Auteurs : Shaofeng Gong, Auteur ; Akira Shinozaki, Auteur ; Eika W. Qian, Auteur Année de publication : 2013 Article en page(s) : pp. 13953–13960 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydrotreatment Catalysts Résumé : Hydrotreatment of jatropha oil over a series of sulfided NiMo/SiO2–Al2O3 and NiMo/ZSM-5–Al2O3 catalysts in a fixed-bed reactor was carried out. Effect of support on various reactions occurring in hydrotreatment was investigated. For NiMo/SiO2–Al2O3 series catalysts, the rates of decarboxylation and/or decarbonylation increased with increasing Si/(Si+Al) ratio, while the ratio of hydrodeoxygenation decreased with increasing Si/(Si+Al) ratio. For NiMo/ZSM-5–Al2O3 series catalysts, with increasing amounts of ZSM-5, the rate of decarboxylation and/or decarbonylation versus hydrodeoxygenation did not change. These results could be attributed to the total acidic sites of catalyst having a positive effect on the decarboxylation and/or decarbonylation pathways. NiMo/SiO2–Al2O3 catalysts showed a much higher isomerization/cracking ratio than NiMo/ZSM-5–Al2O3 catalysts. It was suggested that isomerization reaction was favorable for weak and middle acidic sites but cracking reaction was favorable for strong acidic sites. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301204u
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13953–13960[article] Role of support in hydrotreatment of jatropha oil over sulfided NiMo catalysts [texte imprimé] / Shaofeng Gong, Auteur ; Akira Shinozaki, Auteur ; Eika W. Qian, Auteur . - 2013 . - pp. 13953–13960.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13953–13960
Mots-clés : Hydrotreatment Catalysts Résumé : Hydrotreatment of jatropha oil over a series of sulfided NiMo/SiO2–Al2O3 and NiMo/ZSM-5–Al2O3 catalysts in a fixed-bed reactor was carried out. Effect of support on various reactions occurring in hydrotreatment was investigated. For NiMo/SiO2–Al2O3 series catalysts, the rates of decarboxylation and/or decarbonylation increased with increasing Si/(Si+Al) ratio, while the ratio of hydrodeoxygenation decreased with increasing Si/(Si+Al) ratio. For NiMo/ZSM-5–Al2O3 series catalysts, with increasing amounts of ZSM-5, the rate of decarboxylation and/or decarbonylation versus hydrodeoxygenation did not change. These results could be attributed to the total acidic sites of catalyst having a positive effect on the decarboxylation and/or decarbonylation pathways. NiMo/SiO2–Al2O3 catalysts showed a much higher isomerization/cracking ratio than NiMo/ZSM-5–Al2O3 catalysts. It was suggested that isomerization reaction was favorable for weak and middle acidic sites but cracking reaction was favorable for strong acidic sites. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301204u Exemplaires
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Titre : Kinetics of the gas-phase noncatalytic oxidation of hexafluoropropene Type de document : texte imprimé Auteurs : David Lokhat, Auteur ; Deresh Ramjugernath, Auteur ; Maciej Starzak, Auteur Année de publication : 2013 Article en page(s) : pp. 13961-13972 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Oxidation Kinetics Résumé : The kinetics of the high-temperature gas-phase oxidation of hexafluoropropene with molecular oxygen was investigated in an isothermal tubular reactor operating under laminar flow. Measurements were conducted at a total pressure of 450 kPa and over the temperature range from 463 to 493 K. A reaction scheme involving eight reactions was proposed to model the oxidation process. The initial steps are addition of oxygen to hexafluoropropene to yield hexafluoropropene oxide and some acid fluorides followed by thermal decomposition of the epoxide, radical recombination, and secondary oxidation reactions, giving three major products, viz. hexafluoropropene oxide, carbonyl fluoride, and trifluoroacetyl fluoride, as well as polyoxadifluoromethylene oligomers. Rate parameters for each of the reactions were determined through weighted nonlinear data regression. A plug flow approximation was used for modeling the reactor, as all radial concentration profiles in the long and narrow coiled reactor tube were found to be practically uniform. The proposed kinetic model of hexafluoropropene oxidation is in satisfactory agreement with the experimental observations, including carbon and oxygen element balances as well as thermochemical constraints. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593323
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13961-13972[article] Kinetics of the gas-phase noncatalytic oxidation of hexafluoropropene [texte imprimé] / David Lokhat, Auteur ; Deresh Ramjugernath, Auteur ; Maciej Starzak, Auteur . - 2013 . - pp. 13961-13972.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13961-13972
Mots-clés : Oxidation Kinetics Résumé : The kinetics of the high-temperature gas-phase oxidation of hexafluoropropene with molecular oxygen was investigated in an isothermal tubular reactor operating under laminar flow. Measurements were conducted at a total pressure of 450 kPa and over the temperature range from 463 to 493 K. A reaction scheme involving eight reactions was proposed to model the oxidation process. The initial steps are addition of oxygen to hexafluoropropene to yield hexafluoropropene oxide and some acid fluorides followed by thermal decomposition of the epoxide, radical recombination, and secondary oxidation reactions, giving three major products, viz. hexafluoropropene oxide, carbonyl fluoride, and trifluoroacetyl fluoride, as well as polyoxadifluoromethylene oligomers. Rate parameters for each of the reactions were determined through weighted nonlinear data regression. A plug flow approximation was used for modeling the reactor, as all radial concentration profiles in the long and narrow coiled reactor tube were found to be practically uniform. The proposed kinetic model of hexafluoropropene oxidation is in satisfactory agreement with the experimental observations, including carbon and oxygen element balances as well as thermochemical constraints. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593323 Exemplaires
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Titre : Fuel particle conversion of pulverized biomass during pyrolysis in an entrained flow reactor Type de document : texte imprimé Auteurs : Kentaro Umeki, Auteur ; Kawnish Kirtania, Auteur ; Luguang Chen, Auteur Année de publication : 2013 Article en page(s) : pp. 13973-13979 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Reactor Pyrolysis Biomass Fuel Résumé : This study addresses the change of char morphology and fuel conversion during pyrolysis in a laminar entrained flow reactor by experiments and particle simulation. Three experimental parameters were examined: reaction temperature (1073 and 1273 K); particle size (125-250, 250-500, and 500-1000 μm); and the length of reaction zone (650 and 1885 mm). The scanning electron microscopic (SEM) images showed that biomass swelled during heating and shrank during initial stage of pyrolysis. Then, char morphology transformed to cenospheres after the plastic stage. The yields of solid residue from the experiments were reasonably predicted by particle simulation. To give a guideline for the design of laminar entrained flow pyrolysis reactors, the required reactor length for complete conversion of biomass was also calculated for the pyrolysis. High reaction temperature, small particles, and slower gas flow were favorable for high fuel conversion. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593324
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13973-13979[article] Fuel particle conversion of pulverized biomass during pyrolysis in an entrained flow reactor [texte imprimé] / Kentaro Umeki, Auteur ; Kawnish Kirtania, Auteur ; Luguang Chen, Auteur . - 2013 . - pp. 13973-13979.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13973-13979
Mots-clés : Reactor Pyrolysis Biomass Fuel Résumé : This study addresses the change of char morphology and fuel conversion during pyrolysis in a laminar entrained flow reactor by experiments and particle simulation. Three experimental parameters were examined: reaction temperature (1073 and 1273 K); particle size (125-250, 250-500, and 500-1000 μm); and the length of reaction zone (650 and 1885 mm). The scanning electron microscopic (SEM) images showed that biomass swelled during heating and shrank during initial stage of pyrolysis. Then, char morphology transformed to cenospheres after the plastic stage. The yields of solid residue from the experiments were reasonably predicted by particle simulation. To give a guideline for the design of laminar entrained flow pyrolysis reactors, the required reactor length for complete conversion of biomass was also calculated for the pyrolysis. High reaction temperature, small particles, and slower gas flow were favorable for high fuel conversion. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593324 Exemplaires
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Titre : Performance and Kinetics of Flame-Made Vanadia/Titania Catalyst Nanoparticles in the Partial Oxidation of o-Xylene Type de document : texte imprimé Auteurs : Philip Mulheims, Auteur ; Anika Ritter, Auteur ; Andreas Reitzmann, Auteur Année de publication : 2013 Article en page(s) : pp. 13980-13992 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Partial oxidation Nanoparticle Catalyst Flame Kinetics Résumé : Vanadia/titania catalyst particles were made by flame-spray pyrolysis and deposited onto ceramic sponge monoliths either by direct deposition of the flame-made particles or by a dip-coating technique. In the partial oxidation of o-xylene, the influence of the coating thickness and porosity on the catalytic performance was investigated. It was found that the highly porous coatings obtained by direct deposition exhibit insufficient heat transfer properties, while dip-coated layers are prone to internal mass transfer limitations if a certain thickness of the coating is exceeded. In the absence of transport limitations, kinetic experiments were carried out to derive a reaction network and to develop a quantitative kinetic model. The resulting model describes well the influences of reactant concentrations and temperature on the product distributions in the oxidation of o-xylene to phthalic anhydride over the novel flame-made catalyst and can be used for reactor simulations. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593325
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13980-13992[article] Performance and Kinetics of Flame-Made Vanadia/Titania Catalyst Nanoparticles in the Partial Oxidation of o-Xylene [texte imprimé] / Philip Mulheims, Auteur ; Anika Ritter, Auteur ; Andreas Reitzmann, Auteur . - 2013 . - pp. 13980-13992.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13980-13992
Mots-clés : Partial oxidation Nanoparticle Catalyst Flame Kinetics Résumé : Vanadia/titania catalyst particles were made by flame-spray pyrolysis and deposited onto ceramic sponge monoliths either by direct deposition of the flame-made particles or by a dip-coating technique. In the partial oxidation of o-xylene, the influence of the coating thickness and porosity on the catalytic performance was investigated. It was found that the highly porous coatings obtained by direct deposition exhibit insufficient heat transfer properties, while dip-coated layers are prone to internal mass transfer limitations if a certain thickness of the coating is exceeded. In the absence of transport limitations, kinetic experiments were carried out to derive a reaction network and to develop a quantitative kinetic model. The resulting model describes well the influences of reactant concentrations and temperature on the product distributions in the oxidation of o-xylene to phthalic anhydride over the novel flame-made catalyst and can be used for reactor simulations. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593325 Exemplaires
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Titre : Kinetics of n-butanol partial oxidation to butyraldehyde over lanthanum–transition metal perovskites Type de document : texte imprimé Auteurs : Bing-Shiun Jiang, Auteur ; Ray Chang, Auteur ; Yi-Chen Hou, Auteur Année de publication : 2013 Article en page(s) : pp. 13993-13998 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Partial oxidation Kinetics Résumé : Partial oxidation of butanol to butyraldehyde over a series of LaBO3 (B = Mn, Fe, and Co) perovskites was investigated in a continuous fixed-bed system under ambient pressure. Physicochemical properties of catalysts were characterized by X-ray diffraction, H2 temperature-programmed reduction, and temperature-programmed oxidation. LaMnO, was more favorable to be reduced and reoxidized than LaFeO, and LaCoO3. Catalytic results have indicated that all catalysts show similar butanol and oxygen conversions and over 90% butyraldehyde selectivities below 300 °C. Side reactions such as butanol or butyraldehyde combustion could be enhanced at high temperatures. To gain an in-depth understanding of perovskite's chemistry involved, kinetic analysis has been carried out. Eight reaction pathways based on the Mars-van Krevelen redox cycle were proposed. These pathways have been lumped and associated with the Langmuir―Hinshelwood―Hougen―Watson formalism to derive a set of rate equations. Parameter estimation via nonlinear regression of derived rate equations has shown that surface reaction, evolving chemisorbed butanol and oxygen, is probably rate-determining. The estimated activation energy of LaMnO3 (15.0 kcal/mol) by assuming surface reaction as the rate-limiting step was the lowest among all perovskites. This can be ascribed to the better redox property of LaMnO3, thereby decreasing the energy barrier in butanol partial oxidation. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593326
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13993-13998[article] Kinetics of n-butanol partial oxidation to butyraldehyde over lanthanum–transition metal perovskites [texte imprimé] / Bing-Shiun Jiang, Auteur ; Ray Chang, Auteur ; Yi-Chen Hou, Auteur . - 2013 . - pp. 13993-13998.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13993-13998
Mots-clés : Partial oxidation Kinetics Résumé : Partial oxidation of butanol to butyraldehyde over a series of LaBO3 (B = Mn, Fe, and Co) perovskites was investigated in a continuous fixed-bed system under ambient pressure. Physicochemical properties of catalysts were characterized by X-ray diffraction, H2 temperature-programmed reduction, and temperature-programmed oxidation. LaMnO, was more favorable to be reduced and reoxidized than LaFeO, and LaCoO3. Catalytic results have indicated that all catalysts show similar butanol and oxygen conversions and over 90% butyraldehyde selectivities below 300 °C. Side reactions such as butanol or butyraldehyde combustion could be enhanced at high temperatures. To gain an in-depth understanding of perovskite's chemistry involved, kinetic analysis has been carried out. Eight reaction pathways based on the Mars-van Krevelen redox cycle were proposed. These pathways have been lumped and associated with the Langmuir―Hinshelwood―Hougen―Watson formalism to derive a set of rate equations. Parameter estimation via nonlinear regression of derived rate equations has shown that surface reaction, evolving chemisorbed butanol and oxygen, is probably rate-determining. The estimated activation energy of LaMnO3 (15.0 kcal/mol) by assuming surface reaction as the rate-limiting step was the lowest among all perovskites. This can be ascribed to the better redox property of LaMnO3, thereby decreasing the energy barrier in butanol partial oxidation. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593326 Exemplaires
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Titre : From kinetic study to thermal safety assessment : Application to peroxyformic acid synthesis Type de document : texte imprimé Auteurs : Sébastien Leveneur, Auteur ; Martin Thönes, Auteur ; Jean-Pierre Hébert, Auteur Année de publication : 2013 Article en page(s) : pp. 13999-14007 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Safety Kinetics Résumé : This article proposes a kinetic and thermal study of the formic acid perhydrolysis in a semibatch process at various hydrogen peroxide concentrations (5.32―8.21 mol/L), formic acid molar inlet flow rates (0.04―0.22 mol/min), reaction temperatures (30-60 °C), and catalyst amount (0.0―10.6 g). A cation-exchange resin, i.e., Amberlite IR-120, was used as a catalyst. Synthesis and decomposition of peroxyformic acid were modeled by coupling the energy and mass balances, and a pseudohomogeneous model for the reaction kinetics. A nonlinear regression method was used to estimate the kinetic parameters, such as rate constant, and thermal parameters, such as reaction enthalpy. The knowledge of these parameters allows the determination of maximum temperature of the synthesis reaction (MTSR), the time to maximum rate under adiabatic condition (TMRad), and the criticality classification. These safety parameters are important to properly design the industrial reactor. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593327
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13999-14007[article] From kinetic study to thermal safety assessment : Application to peroxyformic acid synthesis [texte imprimé] / Sébastien Leveneur, Auteur ; Martin Thönes, Auteur ; Jean-Pierre Hébert, Auteur . - 2013 . - pp. 13999-14007.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 13999-14007
Mots-clés : Safety Kinetics Résumé : This article proposes a kinetic and thermal study of the formic acid perhydrolysis in a semibatch process at various hydrogen peroxide concentrations (5.32―8.21 mol/L), formic acid molar inlet flow rates (0.04―0.22 mol/min), reaction temperatures (30-60 °C), and catalyst amount (0.0―10.6 g). A cation-exchange resin, i.e., Amberlite IR-120, was used as a catalyst. Synthesis and decomposition of peroxyformic acid were modeled by coupling the energy and mass balances, and a pseudohomogeneous model for the reaction kinetics. A nonlinear regression method was used to estimate the kinetic parameters, such as rate constant, and thermal parameters, such as reaction enthalpy. The knowledge of these parameters allows the determination of maximum temperature of the synthesis reaction (MTSR), the time to maximum rate under adiabatic condition (TMRad), and the criticality classification. These safety parameters are important to properly design the industrial reactor. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593327 Exemplaires
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Titre : Polyethylene cracking on a spent FCC catalyst in a conical spouted bed Type de document : texte imprimé Auteurs : Gorka Elordi, Auteur ; Martin Olazar, Auteur ; Pedro Castano, Auteur Année de publication : 2013 Article en page(s) : pp. 14008-14017 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Fluidization Spouted bed Catalyst Cracking Résumé : The catalytic cracking of HDPE (high density polyethylene) at 500 °C using a spent FCC catalyst agglomerated with bentonite (50 wt %) has been studied in a conical spouted bed reactor. The reaction is carried out in continuous regime (1 g min―1 of HDPE is fed) with no bed defluidization problems. The results obtained, namely, total conversion, and high yields of gasoline (C5―C11 fraction) (50 wt %) and C2―C4 olefins (28 wt %), are explained by favorable reactor conditions and good catalyst properties. These results are compared with those for a catalyst prepared in the laboratory by agglomerating a commercial HY zeolite (SiO2/Al2O3 = 5.2). The conical spouted bed is a suitable reactor for enhancing the physical steps of melting the polymer and coating the catalyst with the melted polymer. Furthermore, high heat and mass transfer rates promote devolatilization, and short residence times minimize secondary reactions from olefins by enhancing primary cracking products. The meso- and macroporous structure of the spent FCC catalyst matrix enhances the diffusion of long polymer chains, whereas the zeolite crystals have micropores that give a proper shape selectivity to form the lumps of gasoline and light olefins. Because of long use in reaction-regeneration cycles, the moderate acidity of the spent FCC catalyst minimizes the secondary reactions of hydrogen transfer, and so restricts the formation of aromatics and paraffins, as well as the reactions of overcracking and condensation and, therefore, the coke formation. The spent FCC catalyst exhibits a low deactivation rate and is regenerable by coke combustion with air at 550 °C. Consequently, the use of a catalyst with the sole cost of a simple agglomeration and the production of value added product streams make the process of polyolefin catalytic cracking a promising option for refinery integration. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593328
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14008-14017[article] Polyethylene cracking on a spent FCC catalyst in a conical spouted bed [texte imprimé] / Gorka Elordi, Auteur ; Martin Olazar, Auteur ; Pedro Castano, Auteur . - 2013 . - pp. 14008-14017.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14008-14017
Mots-clés : Fluidization Spouted bed Catalyst Cracking Résumé : The catalytic cracking of HDPE (high density polyethylene) at 500 °C using a spent FCC catalyst agglomerated with bentonite (50 wt %) has been studied in a conical spouted bed reactor. The reaction is carried out in continuous regime (1 g min―1 of HDPE is fed) with no bed defluidization problems. The results obtained, namely, total conversion, and high yields of gasoline (C5―C11 fraction) (50 wt %) and C2―C4 olefins (28 wt %), are explained by favorable reactor conditions and good catalyst properties. These results are compared with those for a catalyst prepared in the laboratory by agglomerating a commercial HY zeolite (SiO2/Al2O3 = 5.2). The conical spouted bed is a suitable reactor for enhancing the physical steps of melting the polymer and coating the catalyst with the melted polymer. Furthermore, high heat and mass transfer rates promote devolatilization, and short residence times minimize secondary reactions from olefins by enhancing primary cracking products. The meso- and macroporous structure of the spent FCC catalyst matrix enhances the diffusion of long polymer chains, whereas the zeolite crystals have micropores that give a proper shape selectivity to form the lumps of gasoline and light olefins. Because of long use in reaction-regeneration cycles, the moderate acidity of the spent FCC catalyst minimizes the secondary reactions of hydrogen transfer, and so restricts the formation of aromatics and paraffins, as well as the reactions of overcracking and condensation and, therefore, the coke formation. The spent FCC catalyst exhibits a low deactivation rate and is regenerable by coke combustion with air at 550 °C. Consequently, the use of a catalyst with the sole cost of a simple agglomeration and the production of value added product streams make the process of polyolefin catalytic cracking a promising option for refinery integration. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593328 Exemplaires
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Titre : Preparation of a copper ion selective membrane by surface-modified molecular imprinting Type de document : texte imprimé Auteurs : Huining Deng, Auteur ; Liya Gao, Auteur ; Shaofeng Zhang, Auteur Année de publication : 2013 Article en page(s) : pp. 14018–14025 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Copper ion membrane Résumé : A novel copper ion-selective membrane was prepared by pressure-driven depositing poly(ethyleneimine) (PEI) onto the surface of a polyacrylonitrile (PAN) ultrafiltration (UF) membrane and was subsequently modified with molecular imprinting technique. Examination by infrared spectroscopy and scanning electron microscopy (SEM) confirmed PEI was successfully introduced onto the surface of a hydrolyzed PAN UF membrane. The increase of the pH of copper ion solution was beneficial to the template ion adsorption on the PEI deposited PAN (PEI-PAN) membrane. In ion imprinting, with the cross-linking time prolonged, the adsorption selectivity of the ion imprinted membrane (IIM) increased. The results of binding experiment fitted well with the Langmuir model and showed that the Cu2+ imprinted membrane has the ability of specificity and recognition toward the imprinted copper ion. The imprinting factor calculated from the separation factor was 2.25, indicating that the surface imprinting process facilitated the perm-selectivity of the membrane. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202972j
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14018–14025[article] Preparation of a copper ion selective membrane by surface-modified molecular imprinting [texte imprimé] / Huining Deng, Auteur ; Liya Gao, Auteur ; Shaofeng Zhang, Auteur . - 2013 . - pp. 14018–14025.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14018–14025
Mots-clés : Copper ion membrane Résumé : A novel copper ion-selective membrane was prepared by pressure-driven depositing poly(ethyleneimine) (PEI) onto the surface of a polyacrylonitrile (PAN) ultrafiltration (UF) membrane and was subsequently modified with molecular imprinting technique. Examination by infrared spectroscopy and scanning electron microscopy (SEM) confirmed PEI was successfully introduced onto the surface of a hydrolyzed PAN UF membrane. The increase of the pH of copper ion solution was beneficial to the template ion adsorption on the PEI deposited PAN (PEI-PAN) membrane. In ion imprinting, with the cross-linking time prolonged, the adsorption selectivity of the ion imprinted membrane (IIM) increased. The results of binding experiment fitted well with the Langmuir model and showed that the Cu2+ imprinted membrane has the ability of specificity and recognition toward the imprinted copper ion. The imprinting factor calculated from the separation factor was 2.25, indicating that the surface imprinting process facilitated the perm-selectivity of the membrane. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie202972j Exemplaires
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Titre : Adsorption behaviors and mechanisms of methyl orange on heat-treated palygorskite clays Type de document : texte imprimé Auteurs : Hao Chen, Auteur ; Aiguo Zhong, Auteur ; Junyong Wu, Auteur Année de publication : 2013 Article en page(s) : pp. 14026–14036 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Clay mineral Résumé : Understanding completely the interaction of clay mineral and anionic dye is very important for the applications of clay minerals. In this paper, the adsorption behaviors of heat-treated palygorskite clays for methyl orange (MO) from an aqueous medium were studied using equilibrium batch and theoretic calculation techniques. The crystal structure and surface appearance of the heat-treated samples were studied using Fourier transform infrared (FTIR) and scanning electron microscopy (SEM). The adsorption results reveal that a higher calcining temperature helps in improving removal performance of palygorskite clay for methyl orange. The isothermal adsorption experiments show that there is almost no adsorption at low dye concentrations but a sudden linear increase occurs when the dye concentration exceeds to a certain value. A lower change point is observed for 700 °C treated sample compared with that of the natural sample. The leaching of exchangeable Mg2+ ions located in palygorskite should be a key factor affecting the adsorption capacity. Both the experimental and theoretical studies suggest that the adsorption of MO onto heat-treated palygorskite clay is controlled by the two mechanisms: for samples treated at lower temperatures (400 °C), electrostatic interaction between the dye–Mg2+ complexes and negatively charged surface of heat-treated palygorskite clay becomes dominant. In addition, the latter becomes stronger with the increasing the calcination temperature, which can be ascribed to the formation of a higher ratio of complexes and stronger negatively charged surface of the adsorbent caused by leaching of more metal ions. This work provides a deep insight into the interaction of heat-treated palygorskite clay and anionic dye, which paves the way for their practical applications in anionic dye adsorption. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300702j
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14026–14036[article] Adsorption behaviors and mechanisms of methyl orange on heat-treated palygorskite clays [texte imprimé] / Hao Chen, Auteur ; Aiguo Zhong, Auteur ; Junyong Wu, Auteur . - 2013 . - pp. 14026–14036.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14026–14036
Mots-clés : Clay mineral Résumé : Understanding completely the interaction of clay mineral and anionic dye is very important for the applications of clay minerals. In this paper, the adsorption behaviors of heat-treated palygorskite clays for methyl orange (MO) from an aqueous medium were studied using equilibrium batch and theoretic calculation techniques. The crystal structure and surface appearance of the heat-treated samples were studied using Fourier transform infrared (FTIR) and scanning electron microscopy (SEM). The adsorption results reveal that a higher calcining temperature helps in improving removal performance of palygorskite clay for methyl orange. The isothermal adsorption experiments show that there is almost no adsorption at low dye concentrations but a sudden linear increase occurs when the dye concentration exceeds to a certain value. A lower change point is observed for 700 °C treated sample compared with that of the natural sample. The leaching of exchangeable Mg2+ ions located in palygorskite should be a key factor affecting the adsorption capacity. Both the experimental and theoretical studies suggest that the adsorption of MO onto heat-treated palygorskite clay is controlled by the two mechanisms: for samples treated at lower temperatures (400 °C), electrostatic interaction between the dye–Mg2+ complexes and negatively charged surface of heat-treated palygorskite clay becomes dominant. In addition, the latter becomes stronger with the increasing the calcination temperature, which can be ascribed to the formation of a higher ratio of complexes and stronger negatively charged surface of the adsorbent caused by leaching of more metal ions. This work provides a deep insight into the interaction of heat-treated palygorskite clay and anionic dye, which paves the way for their practical applications in anionic dye adsorption. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300702j Exemplaires
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Titre : Thermal, Crystallization Properties, and Micellization Behavior of HEC-g-PPDO Copolymer : Microstructure Parameters Effect Type de document : texte imprimé Auteurs : Xue-Ting Dong, Auteur ; Wen-Ting Shi, Auteur ; Hai-Chun Dang, Auteur Année de publication : 2013 Article en page(s) : pp. 14037–14046 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Crystallization properties Micellization Résumé : Hydroxyethylcellulose (HEC)-graft-poly(p-dioxanone) (PPDO) copolymer (HEC-g-PPDO) was synthesized homogeneously in ionic liquid 1-butyl-3-methylimidazolium chloride by coupling PPDO onto HEC backbone in the presence of 1,6-hexamethylene diisocyanate (HDI). When the feed ratio of PPDO and HEC was adjusted, as well as the molecular weight of PPDO, a series of HEC-g-PPDO copolymers with different microstructure parameters were obtained. The chemical structure, thermal stability, and thermal transition behaviors were investigated by FT-IR, 1H NMR, TG, DSC, and nano DSC, respectively. These amphiphilic HEC-g-PPDO copolymers can self-assembly into micelles. The critical micelle concentration (CMC) and the hydrodynamic diameters were determined by fluorescence and dynamic light scattering (DLS) analyses. It was found that both the degree of substitution (DS) and polymerization (DP) of PPDO had an effect on the thermal stability, crystallization, and micellization of HEC-g-PPDO copolymers. Due to the crystallization of PPDO side chain, HEC-g-11.7PPDO0.15 whose DP and DS are 11.7 and 0.15, respectively, shows a minimum CMC value. The micelle size was in the range of 200–800 nm depending on the microstructure parameters of HEC-g-PPDO copolymers. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300873a
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14037–14046[article] Thermal, Crystallization Properties, and Micellization Behavior of HEC-g-PPDO Copolymer : Microstructure Parameters Effect [texte imprimé] / Xue-Ting Dong, Auteur ; Wen-Ting Shi, Auteur ; Hai-Chun Dang, Auteur . - 2013 . - pp. 14037–14046.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14037–14046
Mots-clés : Crystallization properties Micellization Résumé : Hydroxyethylcellulose (HEC)-graft-poly(p-dioxanone) (PPDO) copolymer (HEC-g-PPDO) was synthesized homogeneously in ionic liquid 1-butyl-3-methylimidazolium chloride by coupling PPDO onto HEC backbone in the presence of 1,6-hexamethylene diisocyanate (HDI). When the feed ratio of PPDO and HEC was adjusted, as well as the molecular weight of PPDO, a series of HEC-g-PPDO copolymers with different microstructure parameters were obtained. The chemical structure, thermal stability, and thermal transition behaviors were investigated by FT-IR, 1H NMR, TG, DSC, and nano DSC, respectively. These amphiphilic HEC-g-PPDO copolymers can self-assembly into micelles. The critical micelle concentration (CMC) and the hydrodynamic diameters were determined by fluorescence and dynamic light scattering (DLS) analyses. It was found that both the degree of substitution (DS) and polymerization (DP) of PPDO had an effect on the thermal stability, crystallization, and micellization of HEC-g-PPDO copolymers. Due to the crystallization of PPDO side chain, HEC-g-11.7PPDO0.15 whose DP and DS are 11.7 and 0.15, respectively, shows a minimum CMC value. The micelle size was in the range of 200–800 nm depending on the microstructure parameters of HEC-g-PPDO copolymers. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie300873a Exemplaires
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Titre : Isothermal crystallization kinetics, morphology, and mechanical properties of biocomposites based on poly(3-hydroxybutyrate-co-4-hydroxybutyrate) and recycled carbon fiber Type de document : texte imprimé Auteurs : Hongyan Han, Auteur ; Xiaodong Wang, Auteur ; Dezhen Wu, Auteur Année de publication : 2013 Article en page(s) : pp. 14047-14060 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Carbon fiber Mechanical properties Morphology Kinetics Crystallization Résumé : The biocomposites of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3,4HB)] and recycled carbon fiber (RCF) were prepared via a melting extrusion. The crystallization behaviors and kinetics of the P(3,4HB) matrix in composites were exclusively studied under both nonisothermal and isothermal conditions. The corresponding results indicated that the P(3,4HB) either neat or compositing with RCF had a dual-peak cold crystallization behavior in the nonisothermal condition, and the isothermal crystallization rate of P(3,4HB) in composites was jointly determined by the rates of the nucleation and the crystal growth and integrity. However, it was reduced with the incorporation of RCF. Wide-angle X-ray scattering investigation demonstrated that the presence of RCF did not change the crystallization mechanism and crystalline structure of the P(3,4HB) matrix, but the crystallinity of the P(3,4HB) either neat or compositing with RCF was enhanced with an increase of crystallization temperature. Dynamic mechanical analysis revealed that the storage moduli of P(3,4HB)-based composites were significantly improved with increasing the RCF loadings, and the dual internal friction peaks corresponding to the thermal motion of surface molecule of crystalline zone and the glass transfer of whole macromolecules were observed on the thermograms of the P(3,4HB) either neat or compositing with RCF. The mechanical properties including tensile, flexural, and notched Izod impact strength were significantly improved in the presence of RCF, and such reinforcing and toughening effects were due to the good interfacial adhesion between RCF and P(3,4HB) as a result of bonding effect of silane coupling agent. Scanning electronic microscopy further confirmed a good dispersion of RCF in P(3,4HB) matrix and a strong interfacial interaction between fibers and matrix. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593332
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14047-14060[article] Isothermal crystallization kinetics, morphology, and mechanical properties of biocomposites based on poly(3-hydroxybutyrate-co-4-hydroxybutyrate) and recycled carbon fiber [texte imprimé] / Hongyan Han, Auteur ; Xiaodong Wang, Auteur ; Dezhen Wu, Auteur . - 2013 . - pp. 14047-14060.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14047-14060
Mots-clés : Carbon fiber Mechanical properties Morphology Kinetics Crystallization Résumé : The biocomposites of poly(3-hydroxybutyrate-co-4-hydroxybutyrate) [P(3,4HB)] and recycled carbon fiber (RCF) were prepared via a melting extrusion. The crystallization behaviors and kinetics of the P(3,4HB) matrix in composites were exclusively studied under both nonisothermal and isothermal conditions. The corresponding results indicated that the P(3,4HB) either neat or compositing with RCF had a dual-peak cold crystallization behavior in the nonisothermal condition, and the isothermal crystallization rate of P(3,4HB) in composites was jointly determined by the rates of the nucleation and the crystal growth and integrity. However, it was reduced with the incorporation of RCF. Wide-angle X-ray scattering investigation demonstrated that the presence of RCF did not change the crystallization mechanism and crystalline structure of the P(3,4HB) matrix, but the crystallinity of the P(3,4HB) either neat or compositing with RCF was enhanced with an increase of crystallization temperature. Dynamic mechanical analysis revealed that the storage moduli of P(3,4HB)-based composites were significantly improved with increasing the RCF loadings, and the dual internal friction peaks corresponding to the thermal motion of surface molecule of crystalline zone and the glass transfer of whole macromolecules were observed on the thermograms of the P(3,4HB) either neat or compositing with RCF. The mechanical properties including tensile, flexural, and notched Izod impact strength were significantly improved in the presence of RCF, and such reinforcing and toughening effects were due to the good interfacial adhesion between RCF and P(3,4HB) as a result of bonding effect of silane coupling agent. Scanning electronic microscopy further confirmed a good dispersion of RCF in P(3,4HB) matrix and a strong interfacial interaction between fibers and matrix. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593332 Exemplaires
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Titre : On the extraction of double-layer capacitances for nonideal capacitive behaviors Type de document : texte imprimé Auteurs : Muzaffer Ozcan, Auteur ; İlyas Dehri, Auteur ; Mehmet Erbil, Auteur Année de publication : 2013 Article en page(s) : pp. 14061-14064 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Capacitance Résumé : The equation for ideal capacitive behavior of a metal/solution interface was modified in such a way that it allows direct extraction of double-layer capacitance (Cdl) values as a function of the frequency from complex plane plots exhibiting nonideal behavior. Experimental impedance data verified by the Kramers-Kronig (K-K) transforms were presented for a mild steel/hydrochloric acid interface in the absence and presence of an organic additive. The results revealed that the modified equation works well for real systems. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593333
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14061-14064[article] On the extraction of double-layer capacitances for nonideal capacitive behaviors [texte imprimé] / Muzaffer Ozcan, Auteur ; İlyas Dehri, Auteur ; Mehmet Erbil, Auteur . - 2013 . - pp. 14061-14064.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14061-14064
Mots-clés : Capacitance Résumé : The equation for ideal capacitive behavior of a metal/solution interface was modified in such a way that it allows direct extraction of double-layer capacitance (Cdl) values as a function of the frequency from complex plane plots exhibiting nonideal behavior. Experimental impedance data verified by the Kramers-Kronig (K-K) transforms were presented for a mild steel/hydrochloric acid interface in the absence and presence of an organic additive. The results revealed that the modified equation works well for real systems. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593333 Exemplaires
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Titre : Preparation and characterization of flame-retardant aluminum hypophosphite/Poly(Vinyl Alcohol) composite Type de document : texte imprimé Auteurs : Bihe Yuan, Auteur ; Chenlu Bao, Auteur ; Yuqiang Guo, Auteur Année de publication : 2013 Article en page(s) : pp. 14065-14075 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Composite material Flame retardant Preparation Résumé : Composites based on poly(vinyl alcohol) (PVA) and aluminum hypophosphite (AHP) are prepared by solvent blending. The thermal, mechanical, and crystallinity properties of the composites are studied. AHP remarkably improves the char residue yield during the thermal degradation and combustion of AHP/PVA composites. The flame retardancy of the composites is obviously improved. The increased char which protects underlying PVA from heat and oxygen is one of the key reasons for the improved flame retardancy. The crystallinity of the composites is decreased. The glass transition temperature (Tg) and the storage modulus of the composites are increased. In the composite with 15 wt % AHP, limiting oxygen index (LOI) reaches 28.0%, UL-94 V-0 rating is obtained, Tg is increased by 7 °C, and the storage modulus is increased by 17.2% in comparison with neat PVA. Moreover, AHP/PVA composites keep high transparence and maintain most of the mechanical properties of PVA, which is advantageous for the practical application of the composites. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593334
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14065-14075[article] Preparation and characterization of flame-retardant aluminum hypophosphite/Poly(Vinyl Alcohol) composite [texte imprimé] / Bihe Yuan, Auteur ; Chenlu Bao, Auteur ; Yuqiang Guo, Auteur . - 2013 . - pp. 14065-14075.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14065-14075
Mots-clés : Composite material Flame retardant Preparation Résumé : Composites based on poly(vinyl alcohol) (PVA) and aluminum hypophosphite (AHP) are prepared by solvent blending. The thermal, mechanical, and crystallinity properties of the composites are studied. AHP remarkably improves the char residue yield during the thermal degradation and combustion of AHP/PVA composites. The flame retardancy of the composites is obviously improved. The increased char which protects underlying PVA from heat and oxygen is one of the key reasons for the improved flame retardancy. The crystallinity of the composites is decreased. The glass transition temperature (Tg) and the storage modulus of the composites are increased. In the composite with 15 wt % AHP, limiting oxygen index (LOI) reaches 28.0%, UL-94 V-0 rating is obtained, Tg is increased by 7 °C, and the storage modulus is increased by 17.2% in comparison with neat PVA. Moreover, AHP/PVA composites keep high transparence and maintain most of the mechanical properties of PVA, which is advantageous for the practical application of the composites. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593334 Exemplaires
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Titre : Surface tension of polytetrafluoroethylene and polymethyl methacrylate under the Influence of the fluorocarbon surfactant film Type de document : texte imprimé Auteurs : Katarzyna Szymczyk, Auteur ; Bronislaw Janczuk, Auteur Année de publication : 2013 Article en page(s) : pp. 14076-14083 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Surfactant Surface tension Résumé : Measurements of the contact angle for water, formamide, and diiodomethane on polytetrafluoroethylene (PTFE) and polymethyl methacrylate (PMMA) covered by Zonyl FSN-100 (FSN100) and Zonyl FSO-100 (FSO100) films were made. On the basis of the obtained values, the Lifshitz-van der Waals component and electron-acceptor and electron-donor parameters of the acid-base component of PTFE and PMMA covered by the surfactant film surface tension were determined by the use of van Oss et al. approach to the interfacial tension and Young's equation. The components and parameters of surface tension were discussed in the light of the sorption of fluorocarbon surfactants at the polymer/solution interface and proper orientation of the surfactant molecules to this interface. Taking into account the changes of determined values of the components and parameters of PTFE and PMMA surface tension under influence of the surfactant films, the relationship between the adhesion tension and the surface tension, as well as between the cosine of contact angle and the surface tension of aqueous solution of fluorocarbon surfactants, was explained. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593335
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14076-14083[article] Surface tension of polytetrafluoroethylene and polymethyl methacrylate under the Influence of the fluorocarbon surfactant film [texte imprimé] / Katarzyna Szymczyk, Auteur ; Bronislaw Janczuk, Auteur . - 2013 . - pp. 14076-14083.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14076-14083
Mots-clés : Surfactant Surface tension Résumé : Measurements of the contact angle for water, formamide, and diiodomethane on polytetrafluoroethylene (PTFE) and polymethyl methacrylate (PMMA) covered by Zonyl FSN-100 (FSN100) and Zonyl FSO-100 (FSO100) films were made. On the basis of the obtained values, the Lifshitz-van der Waals component and electron-acceptor and electron-donor parameters of the acid-base component of PTFE and PMMA covered by the surfactant film surface tension were determined by the use of van Oss et al. approach to the interfacial tension and Young's equation. The components and parameters of surface tension were discussed in the light of the sorption of fluorocarbon surfactants at the polymer/solution interface and proper orientation of the surfactant molecules to this interface. Taking into account the changes of determined values of the components and parameters of PTFE and PMMA surface tension under influence of the surfactant films, the relationship between the adhesion tension and the surface tension, as well as between the cosine of contact angle and the surface tension of aqueous solution of fluorocarbon surfactants, was explained. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593335 Exemplaires
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Titre : Thermophysical properties and proton transport mechanisms of trialkylammonium and 1-Alkyl-1H-imidazol-3-ium protic ionic liquids Type de document : texte imprimé Auteurs : Janice L. Lebga-Nebane, Auteur ; Simon E. Rock, Auteur ; Joshua Franclemont, Auteur Année de publication : 2013 Article en page(s) : pp. 14084-14098 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Ionic liquid Transport process Résumé : We investigated the thermophysical and electrochemical properties of eight model protic ionic liquids (PILs) primarily because of our interest in their proton conductivity and low volatility. The chemical structures of the cations (ammonium vs imidazolium) and anions (mesylate vs triflate) were found to strongly govern properties such as density, viscosity, ionic conductivity, thermal and electrochemical stability, and phase transition behaviors. Structure-property relations were analyzed on the basis of charge delocalization, cation π-stacking, van der Waals interactions of alkyl tails, and hydrogen bonding interactions between cations and anions. The diffusion coefficients of the free proton, the cation, and the anion were determined by using NMR spectroscopy, and were used to differentiate between the vehicular and Grotthuss mechanisms of diffusion of protons. A correlation, based on the Sutherland―Einstein equation, was developed to predict ionic conductivity by using the room temperature molar volume and the VFT equation for viscosity. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593336
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14084-14098[article] Thermophysical properties and proton transport mechanisms of trialkylammonium and 1-Alkyl-1H-imidazol-3-ium protic ionic liquids [texte imprimé] / Janice L. Lebga-Nebane, Auteur ; Simon E. Rock, Auteur ; Joshua Franclemont, Auteur . - 2013 . - pp. 14084-14098.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14084-14098
Mots-clés : Ionic liquid Transport process Résumé : We investigated the thermophysical and electrochemical properties of eight model protic ionic liquids (PILs) primarily because of our interest in their proton conductivity and low volatility. The chemical structures of the cations (ammonium vs imidazolium) and anions (mesylate vs triflate) were found to strongly govern properties such as density, viscosity, ionic conductivity, thermal and electrochemical stability, and phase transition behaviors. Structure-property relations were analyzed on the basis of charge delocalization, cation π-stacking, van der Waals interactions of alkyl tails, and hydrogen bonding interactions between cations and anions. The diffusion coefficients of the free proton, the cation, and the anion were determined by using NMR spectroscopy, and were used to differentiate between the vehicular and Grotthuss mechanisms of diffusion of protons. A correlation, based on the Sutherland―Einstein equation, was developed to predict ionic conductivity by using the room temperature molar volume and the VFT equation for viscosity. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593336 Exemplaires
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Titre : Preparation of uniform magnetic chitosan microcapsules and their application in adsorbing copper ion(II) and chromium ion(III) Type de document : texte imprimé Auteurs : Sai Zhang, Auteur ; Yifeng Zhou, Auteur ; Wangyan Nie, Auteur Année de publication : 2013 Article en page(s) : pp. 14099-14106 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Microcapsule Preparation Résumé : Biocompatible and biodegradable magnetic chitosan microcapsules were successfully prepared using carboxyl-functionalized polystyrene (PS) particles as core template. First, the monodisperse PS template with an average diameter of 340 nm was made by emulsifier-free emulsion polymerization. Second, the chitosan (CS) adsorbed onto the surface of the PS template and cross-linked by glutaraldehyde. After removal of the PS core, CS microcapsules could be obtained. The shell thickness of CS could be controlled between 20 and 45 nm by varying the adsorption temperature. Third, the CS microcapsules were used as a microreactor, and iron oxide nanoparticles were incorporated within CS microcapsules. The structure and morphology of the PS template, core―shell PS/CS particles, and magnetic CS microcapsules were characterized by Fourier transform infrared spectroscopy and transmission electron microscopy. The adsorption of Cu2+ and Cr3+ was investigated including the effects of adsorption time, pH value, temperature, and initial concentration by the batch method. The optimal condition for adsorption of Cu2+ and Cr3+ was 30 °C, with a pH value of 7.0, where the saturated adsorption capacity was 104 mg/g and 159 mg/g, respectively. The adsorption isotherms obeyed the Langmuir equation, and kinetics followed a pseudo-second-order model. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593337
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14099-14106[article] Preparation of uniform magnetic chitosan microcapsules and their application in adsorbing copper ion(II) and chromium ion(III) [texte imprimé] / Sai Zhang, Auteur ; Yifeng Zhou, Auteur ; Wangyan Nie, Auteur . - 2013 . - pp. 14099-14106.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14099-14106
Mots-clés : Microcapsule Preparation Résumé : Biocompatible and biodegradable magnetic chitosan microcapsules were successfully prepared using carboxyl-functionalized polystyrene (PS) particles as core template. First, the monodisperse PS template with an average diameter of 340 nm was made by emulsifier-free emulsion polymerization. Second, the chitosan (CS) adsorbed onto the surface of the PS template and cross-linked by glutaraldehyde. After removal of the PS core, CS microcapsules could be obtained. The shell thickness of CS could be controlled between 20 and 45 nm by varying the adsorption temperature. Third, the CS microcapsules were used as a microreactor, and iron oxide nanoparticles were incorporated within CS microcapsules. The structure and morphology of the PS template, core―shell PS/CS particles, and magnetic CS microcapsules were characterized by Fourier transform infrared spectroscopy and transmission electron microscopy. The adsorption of Cu2+ and Cr3+ was investigated including the effects of adsorption time, pH value, temperature, and initial concentration by the batch method. The optimal condition for adsorption of Cu2+ and Cr3+ was 30 °C, with a pH value of 7.0, where the saturated adsorption capacity was 104 mg/g and 159 mg/g, respectively. The adsorption isotherms obeyed the Langmuir equation, and kinetics followed a pseudo-second-order model. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593337 Exemplaires
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Titre : Novel unsaturated aliphatic polyesters : Synthesis, characterization, and properties of multiblock copolymers composing of poly(butylene fumarate) and poly(1,2-propylene succinate) Type de document : texte imprimé Auteurs : Liuchun Zheng, Auteur ; Zhaodong Wang, Auteur ; Chuncheng Li, Auteur Année de publication : 2013 Article en page(s) : pp. 14107-14114 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Aliphatic compound Résumé : Widespread application of biodegradable polyesters is restrained by various disadvantages such as inadequate thermomechanical properties, high cost, and lack of reactive sites for further modification. Poly(butylene fumarate) (PBF), as a novel and low-cost aliphatic polyester, possesses good physical properties and reactive double bonds along with the polymer backbones which can be potentially modified to endow the polyester with specific properties. However, the biodegradation rate of PBF is too slow to meet the requirement of practical application. In this contribution, amorphous poly(1,2-propylene succinate) (PPS) was copolymerized with PBF to decrease the crystallinity (Xc) and accelerate the biodegradability of PBF via chain-extension with diisocyanate. The chemical structures of the copolymers were confirmed by 1H NMR spectra and gel permeation chromatography (GPC). The crystal structure and physicochemical properties were investigated by wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), mechanical testing, and enzymatic degradation in detail. Both the impact strength and degradation rate of the copolymers are effectively improved by the introduction of amorphous PPS; while the melting point (Tm) and crystallization temperature (Tc) are hardly reduced by the incorporation of PPS. The novel polymer may be directed used as low-cost biodegradable materials or be further functionalized with special properties for particular applications. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593338
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14107-14114[article] Novel unsaturated aliphatic polyesters : Synthesis, characterization, and properties of multiblock copolymers composing of poly(butylene fumarate) and poly(1,2-propylene succinate) [texte imprimé] / Liuchun Zheng, Auteur ; Zhaodong Wang, Auteur ; Chuncheng Li, Auteur . - 2013 . - pp. 14107-14114.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14107-14114
Mots-clés : Aliphatic compound Résumé : Widespread application of biodegradable polyesters is restrained by various disadvantages such as inadequate thermomechanical properties, high cost, and lack of reactive sites for further modification. Poly(butylene fumarate) (PBF), as a novel and low-cost aliphatic polyester, possesses good physical properties and reactive double bonds along with the polymer backbones which can be potentially modified to endow the polyester with specific properties. However, the biodegradation rate of PBF is too slow to meet the requirement of practical application. In this contribution, amorphous poly(1,2-propylene succinate) (PPS) was copolymerized with PBF to decrease the crystallinity (Xc) and accelerate the biodegradability of PBF via chain-extension with diisocyanate. The chemical structures of the copolymers were confirmed by 1H NMR spectra and gel permeation chromatography (GPC). The crystal structure and physicochemical properties were investigated by wide-angle X-ray diffraction (WAXD), differential scanning calorimetry (DSC), mechanical testing, and enzymatic degradation in detail. Both the impact strength and degradation rate of the copolymers are effectively improved by the introduction of amorphous PPS; while the melting point (Tm) and crystallization temperature (Tc) are hardly reduced by the incorporation of PPS. The novel polymer may be directed used as low-cost biodegradable materials or be further functionalized with special properties for particular applications. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593338 Exemplaires
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Titre : Molecular-level understanding of the inhibition efficiency of some inhibitors of zinc corrosion by quantum chemical approach Type de document : texte imprimé Auteurs : Gokhan Gece, Auteur ; Semra Bilgic, Auteur Année de publication : 2013 Article en page(s) : pp. 14115-14120 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Corrosion Résumé : 2-[4-(Methylthio) phenyl] acetohydrazide (HYD) and 5-[4-(methylthio)benzyl]-4H-1,2,4-triazole-3-thiol (TRD) are compounds that contain methylthiophenyl moiety and substantially inhibit corrosion of zinc in acidic medium. The relationship between molecular structures and inhibition efficiencies of these intriguing inhibitors remains the subject of intense speculation, as introduction of thiophenyl group in strategic positions of many molecules alters their activity. We have performed density functional theory calculations at the B3LYP/6-311++G(d,p) level to analyze the inhibition mechanisms proposed for these compounds. In agreement with experiments, the results afford a full explanation of the highest efficiency observed for TRD in terms of electronic and structural characteristics. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593339
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14115-14120[article] Molecular-level understanding of the inhibition efficiency of some inhibitors of zinc corrosion by quantum chemical approach [texte imprimé] / Gokhan Gece, Auteur ; Semra Bilgic, Auteur . - 2013 . - pp. 14115-14120.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14115-14120
Mots-clés : Corrosion Résumé : 2-[4-(Methylthio) phenyl] acetohydrazide (HYD) and 5-[4-(methylthio)benzyl]-4H-1,2,4-triazole-3-thiol (TRD) are compounds that contain methylthiophenyl moiety and substantially inhibit corrosion of zinc in acidic medium. The relationship between molecular structures and inhibition efficiencies of these intriguing inhibitors remains the subject of intense speculation, as introduction of thiophenyl group in strategic positions of many molecules alters their activity. We have performed density functional theory calculations at the B3LYP/6-311++G(d,p) level to analyze the inhibition mechanisms proposed for these compounds. In agreement with experiments, the results afford a full explanation of the highest efficiency observed for TRD in terms of electronic and structural characteristics. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593339 Exemplaires
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Titre : Quantification of valve stiction and dead band in control loops based on the harmonic balance method Type de document : texte imprimé Auteurs : Alancardek P. Araujo, Auteur ; Celso J. Munaro, Auteur ; Moacir Rosado Filho, Auteur Année de publication : 2013 Article en page(s) : pp. 14121-14134 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Valve Résumé : The presence of stiction in control valves often causes oscillations in control loops, with negative effects on quality and cost of goods. To address this issue, it is necessary to quantify this stiction to decide about maintenance or to implement compensators that can improve control loop performance until the next plant stop. The describing function (DF) method is a well-known scheme to predict the period and amplitude of limit cycles in control loops, requiring the knowledge of linear and nonlinear parameters of the system model. In the present study, a method has been proposed to estimate these nonlinear parameters using the parameters of linear model and amplitude and period of limit cycle produced by nonlinearity. A procedure is proposed to overcome the case of unknown process model. In addition, generalization of this method to the case of parametric uncertainties in the linear part of the control loop has also been presented. The result is a simple and efficient algorithm that can be easily extended to other nonlinearities. Furthermore, the conditions for existence and uniqueness of solution for dead band and stiction estimations have been obtained. The usefulness of the proposed method has been demonstrated through simulations and its applications to a pilot plant and to real industrial data. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593340
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14121-14134[article] Quantification of valve stiction and dead band in control loops based on the harmonic balance method [texte imprimé] / Alancardek P. Araujo, Auteur ; Celso J. Munaro, Auteur ; Moacir Rosado Filho, Auteur . - 2013 . - pp. 14121-14134.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14121-14134
Mots-clés : Valve Résumé : The presence of stiction in control valves often causes oscillations in control loops, with negative effects on quality and cost of goods. To address this issue, it is necessary to quantify this stiction to decide about maintenance or to implement compensators that can improve control loop performance until the next plant stop. The describing function (DF) method is a well-known scheme to predict the period and amplitude of limit cycles in control loops, requiring the knowledge of linear and nonlinear parameters of the system model. In the present study, a method has been proposed to estimate these nonlinear parameters using the parameters of linear model and amplitude and period of limit cycle produced by nonlinearity. A procedure is proposed to overcome the case of unknown process model. In addition, generalization of this method to the case of parametric uncertainties in the linear part of the control loop has also been presented. The result is a simple and efficient algorithm that can be easily extended to other nonlinearities. Furthermore, the conditions for existence and uniqueness of solution for dead band and stiction estimations have been obtained. The usefulness of the proposed method has been demonstrated through simulations and its applications to a pilot plant and to real industrial data. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593340 Exemplaires
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Titre : Operating Energy Consumption Analysis of RO Desalting System : Effect of Membrane Process and Energy Recovery Device (ERD) Performance Variables Type de document : texte imprimé Auteurs : Bingwei Qi, Auteur ; Yue Wang, Auteur ; Shichang Xu, Auteur Année de publication : 2013 Article en page(s) : pp. 14135-14144 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Energy recovery Desalination consumption Résumé : Significant improvement in reverse osmosis (RO) membrane permeability makes the emergence of thermodynamic restriction in desalting process. Due to the filtration flux, both the accumulation of rejected solute and the subsequent concentration polarization layer contribute to the transmembrane osmotic pressure difference that needs to be overcome by the applied pressure. A theoretically derived formula predicting the permeate flux accounting for pressure drop, effect of applied pressure on solute rejection and concentration polarization is presented, and the obtained average rejection is used to calculate the operating energy consumption of RO process more accurately. On the basis of theoretical considerations, at the limit imposed by thermodynamic restriction, an energy consuming analysis model of RO process was developed to study the effects of RO operating parameters (e.g., recovery rate), energy recovery devices (ERDs) performance variables (efficiency and leakage ratio), and pump efficiencies on the specific energy consumption (SEC). ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593341
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14135-14144[article] Operating Energy Consumption Analysis of RO Desalting System : Effect of Membrane Process and Energy Recovery Device (ERD) Performance Variables [texte imprimé] / Bingwei Qi, Auteur ; Yue Wang, Auteur ; Shichang Xu, Auteur . - 2013 . - pp. 14135-14144.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14135-14144
Mots-clés : Energy recovery Desalination consumption Résumé : Significant improvement in reverse osmosis (RO) membrane permeability makes the emergence of thermodynamic restriction in desalting process. Due to the filtration flux, both the accumulation of rejected solute and the subsequent concentration polarization layer contribute to the transmembrane osmotic pressure difference that needs to be overcome by the applied pressure. A theoretically derived formula predicting the permeate flux accounting for pressure drop, effect of applied pressure on solute rejection and concentration polarization is presented, and the obtained average rejection is used to calculate the operating energy consumption of RO process more accurately. On the basis of theoretical considerations, at the limit imposed by thermodynamic restriction, an energy consuming analysis model of RO process was developed to study the effects of RO operating parameters (e.g., recovery rate), energy recovery devices (ERDs) performance variables (efficiency and leakage ratio), and pump efficiencies on the specific energy consumption (SEC). ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593341 Exemplaires
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Titre : A Multiobjective optimization approach for CCS infrastructure considering cost and environmental impact Type de document : texte imprimé Auteurs : Jae-Uk Lee, Auteur ; Jee-Hoon Han, Auteur ; In-Beum Lee, Auteur Année de publication : 2013 Article en page(s) : pp. 14145-14157 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Environment impact Optimization Résumé : In this study, we address the design of a carbon capture and storage (CCS) infrastructure with economic and environmental concerns. Given a set of available technologies to capture, sequestrate, and transport CO2, the problem consists of determining the optimal planning of the CCS infrastructure capable of satisfying a predefined CO2 reduction target. The planning task is formulated as a multiobjective mixed-integer linear programming (moMILP) problem, which simultaneously accounts for the minimization of cost and environmental impact. The environmental impact is measured through all contributions made by operation and installation of the CCS infrastructure. The emissions considered in the environmental impact analysis are quantified according to the principles of Life Cycle Assessment (LCA), specifically the Eco-indicator 99 method. The multiobjective optimization problem was solved by using the e-constraint method. The capability of the proposed modeling framework is illustrated and applied to a real case study based on Korea, for which valuable insights are obtained. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593342
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14145-14157[article] A Multiobjective optimization approach for CCS infrastructure considering cost and environmental impact [texte imprimé] / Jae-Uk Lee, Auteur ; Jee-Hoon Han, Auteur ; In-Beum Lee, Auteur . - 2013 . - pp. 14145-14157.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14145-14157
Mots-clés : Environment impact Optimization Résumé : In this study, we address the design of a carbon capture and storage (CCS) infrastructure with economic and environmental concerns. Given a set of available technologies to capture, sequestrate, and transport CO2, the problem consists of determining the optimal planning of the CCS infrastructure capable of satisfying a predefined CO2 reduction target. The planning task is formulated as a multiobjective mixed-integer linear programming (moMILP) problem, which simultaneously accounts for the minimization of cost and environmental impact. The environmental impact is measured through all contributions made by operation and installation of the CCS infrastructure. The emissions considered in the environmental impact analysis are quantified according to the principles of Life Cycle Assessment (LCA), specifically the Eco-indicator 99 method. The multiobjective optimization problem was solved by using the e-constraint method. The capability of the proposed modeling framework is illustrated and applied to a real case study based on Korea, for which valuable insights are obtained. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593342 Exemplaires
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Titre : A MINLP study on shell and tube heat exchanger : Hybrid branch and bound/meta-heuristics approaches Type de document : texte imprimé Auteurs : O. Aras, Auteur ; M. Bayramoglu, Auteur Année de publication : 2013 Article en page(s) : pp. 14158-14170 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Mathematical programming Heuristic approach Branch and bound method Heat exchanger Mixed integer Non linear Résumé : Optimal design of shell and tube heat exchangers (STHE) has a crucial role in terms of the energy efficiency of plants. Therefore, it is currently one of the research topics of interest. In this study, a rigorous STHE design model strictly following TEMA standards and including various crucial constraints was established. Ten design variables of various kinds (continuous, integer, discrete, binary, and type) were selected for MINLP task. The handling of noncontinuous variables was attempted by means of three approaches including GA, PSO, and hybrid branch and bound methods over three case studies. Comparisons of the algorithms were performed using various performance criteria. Besides, the presence of noncontinuous variables in MINLP was analyzed. As a brief result, when type/binary/integer variables were included as optimization variables, very poor results were obtained, and hybrid PSO exhibited performance in each case superior to the others in terms of objective function value. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593343
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14158-14170[article] A MINLP study on shell and tube heat exchanger : Hybrid branch and bound/meta-heuristics approaches [texte imprimé] / O. Aras, Auteur ; M. Bayramoglu, Auteur . - 2013 . - pp. 14158-14170.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14158-14170
Mots-clés : Mathematical programming Heuristic approach Branch and bound method Heat exchanger Mixed integer Non linear Résumé : Optimal design of shell and tube heat exchangers (STHE) has a crucial role in terms of the energy efficiency of plants. Therefore, it is currently one of the research topics of interest. In this study, a rigorous STHE design model strictly following TEMA standards and including various crucial constraints was established. Ten design variables of various kinds (continuous, integer, discrete, binary, and type) were selected for MINLP task. The handling of noncontinuous variables was attempted by means of three approaches including GA, PSO, and hybrid branch and bound methods over three case studies. Comparisons of the algorithms were performed using various performance criteria. Besides, the presence of noncontinuous variables in MINLP was analyzed. As a brief result, when type/binary/integer variables were included as optimization variables, very poor results were obtained, and hybrid PSO exhibited performance in each case superior to the others in terms of objective function value. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593343 Exemplaires
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Titre : A Simple graphical utilities targeting method for heat integration between processes Type de document : texte imprimé Auteurs : Anita Kovac Kralj, Auteur Année de publication : 2013 Article en page(s) : pp. 14171-14177 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Utilities Heat recovery Résumé : Heat integration between processes aims at identifying options for heat recovery and optimal energy conversion during industrial processes. This Article introduces a simple graphical utilities targeting method for heat integration between processes. The problem is formulated as a graphical utilities targeting problem for restricting only the heat flow regarding heating and cooling when using utilities. Therefore, the original process cannot be changed but the utilities themselves could attract savings. A mathematical formulation is presented for choosing optimal heat transfer technologies. The grand composite curves of different processes represent optimal heat transfers between processes. This method is very general; it can be used within new designs and within existing processes' integrations for utility savings. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593344
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14171-14177[article] A Simple graphical utilities targeting method for heat integration between processes [texte imprimé] / Anita Kovac Kralj, Auteur . - 2013 . - pp. 14171-14177.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14171-14177
Mots-clés : Utilities Heat recovery Résumé : Heat integration between processes aims at identifying options for heat recovery and optimal energy conversion during industrial processes. This Article introduces a simple graphical utilities targeting method for heat integration between processes. The problem is formulated as a graphical utilities targeting problem for restricting only the heat flow regarding heating and cooling when using utilities. Therefore, the original process cannot be changed but the utilities themselves could attract savings. A mathematical formulation is presented for choosing optimal heat transfer technologies. The grand composite curves of different processes represent optimal heat transfers between processes. This method is very general; it can be used within new designs and within existing processes' integrations for utility savings. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593344 Exemplaires
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Titre : Novel cross-linked polyphosphonate for the removal of Pb2+ and Cu2+ from aqueous solution Type de document : texte imprimé Auteurs : Othman Charles S. Al Hamouz, Auteur ; Shaikh A. Ali, Auteur Année de publication : 2013 Article en page(s) : pp. 14178-14187 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Aqueous solution Résumé : A novel cross-linked polyzwitterionic acid (CPZA) was synthesized via cyclopolymerization of diallylaminomethylphosphonic acid (90 mol %) and 1,1,4,4-tetraallylpiperazinium dichloride (10 mol %), a cross-linker, with sulfur dioxide in the presence of azoisobutyronitrile (AIBN) in dimethylsulfoxide (DMSO) at 65 °C. CPZA, upon treatment with NaOH, was converted into a cross-linked anionic polyelectrolyte (CAPE). The experimental data for the adsorption of Pb2+ and Cu2+ on CAPE fitted the Lagergren second-order kinetic model as well as Langmuir and Freundlich isotherm models. The adsorption capacity of Pb2+ was higher than that of Cu2+, and the rate of adsorption of both metals was found to be almost equal. The maximum adsorption capacity of Pb2+ and Cu2― were determined to be 2.76 and 2.22 mmol g―1, respectively. The adsorption process was spontaneous and endothermic in nature with negative and positive values for ΔG and ΔH, respectively. The relatively low activation energies of 25.5 and 27.1 kJ/mol for Pb2+ and Cu2+, respectively, indicated the adsorption as a favorable process. The excellent adsorption and very good desorption efficiency implied the efficacy of the resin in removing as well as recovering the metal ions from aqueous solution. An efficient synthetic access to the resin would enable its use in the treatment of contaminated wastewater. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593345
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14178-14187[article] Novel cross-linked polyphosphonate for the removal of Pb2+ and Cu2+ from aqueous solution [texte imprimé] / Othman Charles S. Al Hamouz, Auteur ; Shaikh A. Ali, Auteur . - 2013 . - pp. 14178-14187.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14178-14187
Mots-clés : Aqueous solution Résumé : A novel cross-linked polyzwitterionic acid (CPZA) was synthesized via cyclopolymerization of diallylaminomethylphosphonic acid (90 mol %) and 1,1,4,4-tetraallylpiperazinium dichloride (10 mol %), a cross-linker, with sulfur dioxide in the presence of azoisobutyronitrile (AIBN) in dimethylsulfoxide (DMSO) at 65 °C. CPZA, upon treatment with NaOH, was converted into a cross-linked anionic polyelectrolyte (CAPE). The experimental data for the adsorption of Pb2+ and Cu2+ on CAPE fitted the Lagergren second-order kinetic model as well as Langmuir and Freundlich isotherm models. The adsorption capacity of Pb2+ was higher than that of Cu2+, and the rate of adsorption of both metals was found to be almost equal. The maximum adsorption capacity of Pb2+ and Cu2― were determined to be 2.76 and 2.22 mmol g―1, respectively. The adsorption process was spontaneous and endothermic in nature with negative and positive values for ΔG and ΔH, respectively. The relatively low activation energies of 25.5 and 27.1 kJ/mol for Pb2+ and Cu2+, respectively, indicated the adsorption as a favorable process. The excellent adsorption and very good desorption efficiency implied the efficacy of the resin in removing as well as recovering the metal ions from aqueous solution. An efficient synthetic access to the resin would enable its use in the treatment of contaminated wastewater. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593345 Exemplaires
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Titre : Thermodynamic characterization of undefined petroleum fractions using group contribution methods Type de document : texte imprimé Auteurs : Bernardo Carreon-Calderon, Auteur ; Veronica Uribe-Vargas, Auteur ; Edgar Ramirez-Jaramillo, Auteur Année de publication : 2013 Article en page(s) : pp. 14188–14198 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Thermodynamic Résumé : Properties of petroleum fractions of unknown composition, the so-called undefined petroleum fractions, are estimated using an approach based on group contribution methods. Using liquid density and molecular weight as experimental data and classical thermodynamics as framework, functional groups were assigned to each undefined fraction by minimizing its free energy. Thus, methods requiring molecular structures were used directly in phase equilibrium simulations of petroleum fluids. The proposed procedure also allows the critical properties of such undefined fractions to be calculated employing no specific correlations. The obtained results show reasonable accuracy concerning phase equilibrium experiments. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3016076
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14188–14198[article] Thermodynamic characterization of undefined petroleum fractions using group contribution methods [texte imprimé] / Bernardo Carreon-Calderon, Auteur ; Veronica Uribe-Vargas, Auteur ; Edgar Ramirez-Jaramillo, Auteur . - 2013 . - pp. 14188–14198.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14188–14198
Mots-clés : Thermodynamic Résumé : Properties of petroleum fractions of unknown composition, the so-called undefined petroleum fractions, are estimated using an approach based on group contribution methods. Using liquid density and molecular weight as experimental data and classical thermodynamics as framework, functional groups were assigned to each undefined fraction by minimizing its free energy. Thus, methods requiring molecular structures were used directly in phase equilibrium simulations of petroleum fluids. The proposed procedure also allows the critical properties of such undefined fractions to be calculated employing no specific correlations. The obtained results show reasonable accuracy concerning phase equilibrium experiments. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3016076 Exemplaires
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Titre : Membrane-assisted liquid-phase extraction of lu(III) in a U-shaped contactor with a single hollow fiber membrane Type de document : texte imprimé Auteurs : Ksenija R. Kumric, Auteur ; Goran T. Vladisavljevic, Auteur ; Tatjana M. Trtic-Petrovic, Auteur Année de publication : 2013 Article en page(s) : pp. 14199–14208 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Fiber membrane Résumé : Extraction of Lu(III) from an aqueous LuCl3 solution at pH 3.5 into an organic phase containing 5% (v/v) di(2-ethylhexyl)phosphoric acid (DEHPA) in di-n-hexyl ether (DHE) immobilized within a polypropylene hollow fiber membrane and a simultaneous back-extraction of Lu(III) into 2 mol dm–3 HCl solution has been investigated using two miniaturized supported liquid membrane (SLM) systems: (i) a single hollow fiber membrane, with stagnant acceptor phase in the lumen, immersed into a donor phase reservoir; and (ii) a U-shaped module containing a single hollow fiber membrane with a closed-loop recirculation of aqueous phases through the module. In the stagnant SLM system, the maximum extraction efficiency was 8.8% due to limited acceptor volume and absence of flow within the lumen. In recirculating SLM system, after 80 min of operation at the donor phase flow rate of 5.3 cm3 min–1, the acceptor phase flow rate of 0.4 cm3 min–1 and the donor-to-acceptor phase volume ratio of 6.7, the equilibrium removal efficiency of Lu(III) reached 88% and less than 5% of Lu(III) extracted from the feed solution was kept in the organic phase. For shell side flow of the donor phase at Reynolds numbers of Re = 3–34, the overall mass-transfer coefficient was proportional to the donor flow rate raised to the power of 0.63 and increased from 2.3 × 10–5 m s–1 to 8.8 × 10–5 m s–1. The rate-limiting step was the mass transfer of Lu(III) within the boundary layer of the donor phase adjacent to the outer wall of the hollow fiber. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301887h
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14199–14208[article] Membrane-assisted liquid-phase extraction of lu(III) in a U-shaped contactor with a single hollow fiber membrane [texte imprimé] / Ksenija R. Kumric, Auteur ; Goran T. Vladisavljevic, Auteur ; Tatjana M. Trtic-Petrovic, Auteur . - 2013 . - pp. 14199–14208.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14199–14208
Mots-clés : Fiber membrane Résumé : Extraction of Lu(III) from an aqueous LuCl3 solution at pH 3.5 into an organic phase containing 5% (v/v) di(2-ethylhexyl)phosphoric acid (DEHPA) in di-n-hexyl ether (DHE) immobilized within a polypropylene hollow fiber membrane and a simultaneous back-extraction of Lu(III) into 2 mol dm–3 HCl solution has been investigated using two miniaturized supported liquid membrane (SLM) systems: (i) a single hollow fiber membrane, with stagnant acceptor phase in the lumen, immersed into a donor phase reservoir; and (ii) a U-shaped module containing a single hollow fiber membrane with a closed-loop recirculation of aqueous phases through the module. In the stagnant SLM system, the maximum extraction efficiency was 8.8% due to limited acceptor volume and absence of flow within the lumen. In recirculating SLM system, after 80 min of operation at the donor phase flow rate of 5.3 cm3 min–1, the acceptor phase flow rate of 0.4 cm3 min–1 and the donor-to-acceptor phase volume ratio of 6.7, the equilibrium removal efficiency of Lu(III) reached 88% and less than 5% of Lu(III) extracted from the feed solution was kept in the organic phase. For shell side flow of the donor phase at Reynolds numbers of Re = 3–34, the overall mass-transfer coefficient was proportional to the donor flow rate raised to the power of 0.63 and increased from 2.3 × 10–5 m s–1 to 8.8 × 10–5 m s–1. The rate-limiting step was the mass transfer of Lu(III) within the boundary layer of the donor phase adjacent to the outer wall of the hollow fiber. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301887h Exemplaires
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Titre : Selective removal of silver impurity from oxaliplatin by sorption on functionalized polymer Type de document : texte imprimé Auteurs : Pradipta Kumar, Auteur ; Khursheed B. Ansari, Auteur ; Vilas G. Gaikar, Auteur Année de publication : 2013 Article en page(s) : pp. 14209-14217 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Sorption Impurity Résumé : This report relates to synthesis of functionalized polymeric adsorbents for selective removal of silver ion in the presence of platinum(II) from crude oxaliplatin, thus providing an effective method for its purification with a desired impurity profile for silver. Two chelating ligands, thiourea and thiosemicarbazide, were grafted on styrene backbone cross-linked with 2% divinyl benzene (DVB) and tested by batch adsorption studies for the uptake of silver and platinum. The maximum sorption capacity values for both the adsorbents for Ag+ were 101.58 and 67.75 (mg/g), respectively, with an exceptionally high value of separation factor (α = 1155 and 231) over platinum. The experimental sorption data were fitted well with the Langmuir model. Desorption of silver from the polymer can be achieved by using 0.3 M Na2S solution for regeneration. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593348
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14209-14217[article] Selective removal of silver impurity from oxaliplatin by sorption on functionalized polymer [texte imprimé] / Pradipta Kumar, Auteur ; Khursheed B. Ansari, Auteur ; Vilas G. Gaikar, Auteur . - 2013 . - pp. 14209-14217.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14209-14217
Mots-clés : Sorption Impurity Résumé : This report relates to synthesis of functionalized polymeric adsorbents for selective removal of silver ion in the presence of platinum(II) from crude oxaliplatin, thus providing an effective method for its purification with a desired impurity profile for silver. Two chelating ligands, thiourea and thiosemicarbazide, were grafted on styrene backbone cross-linked with 2% divinyl benzene (DVB) and tested by batch adsorption studies for the uptake of silver and platinum. The maximum sorption capacity values for both the adsorbents for Ag+ were 101.58 and 67.75 (mg/g), respectively, with an exceptionally high value of separation factor (α = 1155 and 231) over platinum. The experimental sorption data were fitted well with the Langmuir model. Desorption of silver from the polymer can be achieved by using 0.3 M Na2S solution for regeneration. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593348 Exemplaires
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Titre : Predicting the performance of zeolite imidazolate framework/polymer mixed matrix membranes for CO2, CH4, and H2 separations using molecular simulations Type de document : texte imprimé Auteurs : Gamze Yilmaz, Auteur ; Seda Keskin, Auteur Année de publication : 2013 Article en page(s) : pp. 14218-14228 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Modeling Molecular model Carbon dioxide Zeolite Prediction Résumé : We used molecular simulations to assess the performance of zeolite imidazolate framework (ZIF) based mixed matrix membranes (MMMs) for CO2/CH4, H2/CH4, and H2/CO2 separations. The gas permeability of ZIF based MMMs was estimated based on the gas permeability of pure ZIFs obtained from molecular simulations and the gas permeability of pure polymers obtained from experimental studies. Predicted gas selectivity and permeability were compared with the available experimental data of MMMs in which ZIF-8 and ZIF-90 were used as filler particles. After showing the good agreement between the predictions of theoretical methods and experiments, we estimated gas selectivity and permeability of 360 new MMMs composed of 15 different ZIFs and 24 different polymers. Our results showed that ZIF-11 based MMMs exhibit high performance for separation of CO2/CH4 whereas ZIF-65 based MMMs are good candidates for H2/CO2 separation. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593349
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14218-14228[article] Predicting the performance of zeolite imidazolate framework/polymer mixed matrix membranes for CO2, CH4, and H2 separations using molecular simulations [texte imprimé] / Gamze Yilmaz, Auteur ; Seda Keskin, Auteur . - 2013 . - pp. 14218-14228.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14218-14228
Mots-clés : Modeling Molecular model Carbon dioxide Zeolite Prediction Résumé : We used molecular simulations to assess the performance of zeolite imidazolate framework (ZIF) based mixed matrix membranes (MMMs) for CO2/CH4, H2/CH4, and H2/CO2 separations. The gas permeability of ZIF based MMMs was estimated based on the gas permeability of pure ZIFs obtained from molecular simulations and the gas permeability of pure polymers obtained from experimental studies. Predicted gas selectivity and permeability were compared with the available experimental data of MMMs in which ZIF-8 and ZIF-90 were used as filler particles. After showing the good agreement between the predictions of theoretical methods and experiments, we estimated gas selectivity and permeability of 360 new MMMs composed of 15 different ZIFs and 24 different polymers. Our results showed that ZIF-11 based MMMs exhibit high performance for separation of CO2/CH4 whereas ZIF-65 based MMMs are good candidates for H2/CO2 separation. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593349 Exemplaires
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Titre : Electrochemical characterization of mass transport in porous electrodes Type de document : texte imprimé Auteurs : Quentin de Radiguès, Auteur ; Pierre-Yves Sévar, Auteur ; Frédéric Van Wonterghem, Auteur Année de publication : 2013 Article en page(s) : pp. 14229-14235 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Electrodes Mass transfer Résumé : Mass transport in reticulated vitreous carbon electrodes in flow by mode has been studied with the cathodic deposition of copper as a model reaction. Two methods characterizing mass transport are being compared. The first one relies on determination of the electrorecovery kinetics under mass-transfer limiting conditions in galvanostatic mode. The second method is the determination of the limiting current by a linear potential sweep technique. This technique has been modified to allow for a more unambiguous limiting current determination. In some cases, the modified linear sweep technique can also be used to measure the influence of a gaseous reaction side products on mass transport. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593350
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14229-14235[article] Electrochemical characterization of mass transport in porous electrodes [texte imprimé] / Quentin de Radiguès, Auteur ; Pierre-Yves Sévar, Auteur ; Frédéric Van Wonterghem, Auteur . - 2013 . - pp. 14229-14235.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14229-14235
Mots-clés : Electrodes Mass transfer Résumé : Mass transport in reticulated vitreous carbon electrodes in flow by mode has been studied with the cathodic deposition of copper as a model reaction. Two methods characterizing mass transport are being compared. The first one relies on determination of the electrorecovery kinetics under mass-transfer limiting conditions in galvanostatic mode. The second method is the determination of the limiting current by a linear potential sweep technique. This technique has been modified to allow for a more unambiguous limiting current determination. In some cases, the modified linear sweep technique can also be used to measure the influence of a gaseous reaction side products on mass transport. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593350 Exemplaires
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Titre : Hydrodynamic simulations of seepage catalytic packing internal for catalytic distillation column Type de document : texte imprimé Auteurs : Xingang Li, Auteur ; Hui Zhang, Auteur ; Xin Gao, Auteur Année de publication : 2013 Article en page(s) : pp. 14236–14246 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Hydrodynamic Catalytic distillation Résumé : A seepage catalytic packing internal (SCPI) consisting of catalyst containers with avert-overflow baffles and corrugated metal sheets was developed for a catalytic distillation column. Models used for predicting the pressure drop of the SCPI and the height of liquid above the catalyst bed were built by using a commercial CFD package CFX13.0. Simulation strategies, flow geometry, and boundary conditions of SCPI were described in detail. Taking into account the structure of the corrugated metal sheets indirectly, the porous media model was used to acquire the dry pressure drop of the SCPI. Pseudo single phase formulation was utilized to process two-phase flow simulation for irrigated pressure drop determination. The Euler–Euler two-fluid model was employed to simulate the height of liquid above the catalyst bed and aid in designing the height of catalyst containers with avert-overflow baffles. The dry pressure drop (SCPI-I, SCPI-II), irrigated pressure drop (QLS = 14.06, 23.44 m3/m2/h), and height of liquid above the catalyst bed (HC = 50, 75 mm) were calculated and compared to their experimental counterparts. The average relative error between CFD predictions and the experimental data is in the range 4.26–11.2%. In all cases, the CFD predictions show a good agreement with the experimental data, indicating that these simulation methods are feasible and CFD is a reliable, cost saving, and suitable technique for the design and optimization of SCPI. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3010034
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14236–14246[article] Hydrodynamic simulations of seepage catalytic packing internal for catalytic distillation column [texte imprimé] / Xingang Li, Auteur ; Hui Zhang, Auteur ; Xin Gao, Auteur . - 2013 . - pp. 14236–14246.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14236–14246
Mots-clés : Hydrodynamic Catalytic distillation Résumé : A seepage catalytic packing internal (SCPI) consisting of catalyst containers with avert-overflow baffles and corrugated metal sheets was developed for a catalytic distillation column. Models used for predicting the pressure drop of the SCPI and the height of liquid above the catalyst bed were built by using a commercial CFD package CFX13.0. Simulation strategies, flow geometry, and boundary conditions of SCPI were described in detail. Taking into account the structure of the corrugated metal sheets indirectly, the porous media model was used to acquire the dry pressure drop of the SCPI. Pseudo single phase formulation was utilized to process two-phase flow simulation for irrigated pressure drop determination. The Euler–Euler two-fluid model was employed to simulate the height of liquid above the catalyst bed and aid in designing the height of catalyst containers with avert-overflow baffles. The dry pressure drop (SCPI-I, SCPI-II), irrigated pressure drop (QLS = 14.06, 23.44 m3/m2/h), and height of liquid above the catalyst bed (HC = 50, 75 mm) were calculated and compared to their experimental counterparts. The average relative error between CFD predictions and the experimental data is in the range 4.26–11.2%. In all cases, the CFD predictions show a good agreement with the experimental data, indicating that these simulation methods are feasible and CFD is a reliable, cost saving, and suitable technique for the design and optimization of SCPI. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3010034 Exemplaires
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Titre : Mixing and segregation behavior in a spout-fluid bed : Effect of particle size Type de document : texte imprimé Auteurs : Yong Zhang, Auteur ; Wenqi Zhong, Auteur ; Baosheng Jin, Auteur Année de publication : 2013 Article en page(s) : pp. 14247–14257 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Fluid bed Résumé : The mixing and segregation behavior of a binary mixture have been investigated experimentally in a spout-fluid bed. Three types of binary mixtures were used by mixing glass beads with equal density and dissimilar size. The spouting and fluidizing gas flow rate were adjusted to cover a range of flow regimes, typically including internal jet (IJ), jet in fluidized bed with bubbling (JFB), spouting (S) and spout-fluid (SF). The mixing and segregation behavior were analyzed in terms of flow regimes, concentration profile, and mixing index. The results show that in IJ, the particle circulation is combined with the local segregation where smaller particles migrate to the interface between the jet and stagnant region, even into the latter. In S, the distribution of particle depends greatly on the fountain structure. In JFB, the axial segregation takes place where the smaller particles prevail in the upper part of the bed. Segregation becomes more pronounced with increasing the particle size difference. In addition, a mixing/segregation pattern map is constructed. Three regions including mixing region, segregation region, and intermediate region, are identified by the criterion of mixing index. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301005n
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14247–14257[article] Mixing and segregation behavior in a spout-fluid bed : Effect of particle size [texte imprimé] / Yong Zhang, Auteur ; Wenqi Zhong, Auteur ; Baosheng Jin, Auteur . - 2013 . - pp. 14247–14257.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14247–14257
Mots-clés : Fluid bed Résumé : The mixing and segregation behavior of a binary mixture have been investigated experimentally in a spout-fluid bed. Three types of binary mixtures were used by mixing glass beads with equal density and dissimilar size. The spouting and fluidizing gas flow rate were adjusted to cover a range of flow regimes, typically including internal jet (IJ), jet in fluidized bed with bubbling (JFB), spouting (S) and spout-fluid (SF). The mixing and segregation behavior were analyzed in terms of flow regimes, concentration profile, and mixing index. The results show that in IJ, the particle circulation is combined with the local segregation where smaller particles migrate to the interface between the jet and stagnant region, even into the latter. In S, the distribution of particle depends greatly on the fountain structure. In JFB, the axial segregation takes place where the smaller particles prevail in the upper part of the bed. Segregation becomes more pronounced with increasing the particle size difference. In addition, a mixing/segregation pattern map is constructed. Three regions including mixing region, segregation region, and intermediate region, are identified by the criterion of mixing index. En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301005n Exemplaires
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Titre : Experimental and numerical investigations on the electrostatics generation and transport in the downer reactor of a triple-bed combined circulating fluidized bed Type de document : texte imprimé Auteurs : Yongpan Cheng, Auteur ; Darren Yan Jun Lau, Auteur ; Guoqing Guan, Auteur Année de publication : 2013 Article en page(s) : pp. 14258-14267 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Circulating fluidized bed Fluidization Rector Downer Transport process Résumé : Electrostatics is an inevitable phenomenon in fluidization processes and granular flow systems where collisions between particulates and walls with different materials occur. In this study, the electrostatic performance in the downer reactor of a triple-bed combined circulating fluidized bed was investigated through both experiments and numerical simulations. In numerical simulation the Discrete Element Method (DEM) was adopted to simulate the electrostatic charge generation and transfer occurring in the downer. Both experimental and numerical results showed that the averaged induced currents caused by electrostatics increased with increasing solids mass flux in the downer, and the electrostatics was the strongest near the entrance of the downer because of the highest frequency of collisions between particles and the wall caused by the largest solids holdup at that location. Numerical studies also revealed that the averaged induced currents increased with increasing initial particle velocity and particle size, and the averaged induced current caused by the charge transfer was much larger than those by charge generation through tribocharging. These results may help us better understand the mechanism of electrostatic phenomena, and better cope with challenges and problems caused by electrostatics. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593353
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14258-14267[article] Experimental and numerical investigations on the electrostatics generation and transport in the downer reactor of a triple-bed combined circulating fluidized bed [texte imprimé] / Yongpan Cheng, Auteur ; Darren Yan Jun Lau, Auteur ; Guoqing Guan, Auteur . - 2013 . - pp. 14258-14267.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14258-14267
Mots-clés : Circulating fluidized bed Fluidization Rector Downer Transport process Résumé : Electrostatics is an inevitable phenomenon in fluidization processes and granular flow systems where collisions between particulates and walls with different materials occur. In this study, the electrostatic performance in the downer reactor of a triple-bed combined circulating fluidized bed was investigated through both experiments and numerical simulations. In numerical simulation the Discrete Element Method (DEM) was adopted to simulate the electrostatic charge generation and transfer occurring in the downer. Both experimental and numerical results showed that the averaged induced currents caused by electrostatics increased with increasing solids mass flux in the downer, and the electrostatics was the strongest near the entrance of the downer because of the highest frequency of collisions between particles and the wall caused by the largest solids holdup at that location. Numerical studies also revealed that the averaged induced currents increased with increasing initial particle velocity and particle size, and the averaged induced current caused by the charge transfer was much larger than those by charge generation through tribocharging. These results may help us better understand the mechanism of electrostatic phenomena, and better cope with challenges and problems caused by electrostatics. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593353 Exemplaires
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Titre : Gas holdup, axial dispersion, and mass transfer studies in bubble columns Type de document : texte imprimé Auteurs : Mayank Shah, Auteur ; Anton A. Kiss, Auteur ; Edwin Zondervan, Auteur Année de publication : 2013 Article en page(s) : pp. 14268–14278 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Gas Mass Transfer Résumé : This article presents an extensive study on the gas holdup, axial liquid dispersion, and mass transfer for packed, trayed, and empty bubble columns. Four types of structured packings (Super-Pak, Flexipac, Mellapak, and Gauze) and two types of perforated partition trays (with 25% and 40% tray open area) were used to characterize the packed and trayed bubble columns, respectively. It was observed that the gas holdup and mass transfer characteristics of the packed and trayed bubble columns are superior to those of an empty bubble column, while the axial dispersion coefficients are much lower. This article discusses in detail the effect of the liquid and gas flow rates, liquid-phase viscosity, and type of internals. Additionally, experimental data of the packed, trayed, and empty bubble column are correlated by dimensionless numbers. Novel empirical correlations are proposed for the gas holdup, Bodenstein number (for the axial dispersion coefficient), and Stanton number (for the volumetric mass transfer coefficient), as a function of the Froude and Galileo dimensionless numbers. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301227t
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14268–14278[article] Gas holdup, axial dispersion, and mass transfer studies in bubble columns [texte imprimé] / Mayank Shah, Auteur ; Anton A. Kiss, Auteur ; Edwin Zondervan, Auteur . - 2013 . - pp. 14268–14278.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14268–14278
Mots-clés : Gas Mass Transfer Résumé : This article presents an extensive study on the gas holdup, axial liquid dispersion, and mass transfer for packed, trayed, and empty bubble columns. Four types of structured packings (Super-Pak, Flexipac, Mellapak, and Gauze) and two types of perforated partition trays (with 25% and 40% tray open area) were used to characterize the packed and trayed bubble columns, respectively. It was observed that the gas holdup and mass transfer characteristics of the packed and trayed bubble columns are superior to those of an empty bubble column, while the axial dispersion coefficients are much lower. This article discusses in detail the effect of the liquid and gas flow rates, liquid-phase viscosity, and type of internals. Additionally, experimental data of the packed, trayed, and empty bubble column are correlated by dimensionless numbers. Novel empirical correlations are proposed for the gas holdup, Bodenstein number (for the axial dispersion coefficient), and Stanton number (for the volumetric mass transfer coefficient), as a function of the Froude and Galileo dimensionless numbers. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301227t Exemplaires
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Titre : Formation and characterization of deposits in cyclone dipleg of a commercial residue fluid catalytic cracking reactor Type de document : texte imprimé Auteurs : Sung Won Kim, Auteur ; Ju Wook Lee, Auteur ; Jae Suk Koh, Auteur Année de publication : 2013 Article en page(s) : pp. 14279-14288 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Reactor Fluid catalytic cracking Cyclone Résumé : Deposits in the cyclone dipleg of a commercial residue fluid catalytic cracking (RFCC) reactor, which are one of the primary problems causing abnormal shut-down of RFCC, were characterized using an analytical approach in order to understand the formation mechanism of the deposit. The main components of the deposits are hydrocarbons and a high portion of inorganic matter, reflecting dipleg conditions with particle flow. The deposit consists of two parts of massive bulk matter which are mainly pure Sb metal and catalyst particles surrounded by filamentous cokes and lumps of carbonaceous matters. Nickel nanopowders on the catalyst surface and from heavy oil in vapor phase catalyze the filament coke, which accelerate the increase in the amount of deposits by filtering heavy oil droplets. The Sb metals, originated from injected Ni passivator in the riser, contribute largely to deposit formation, and this is validated by a simulation of RFCC conditions and a calculation of cyclone collection efficiency. Possible mechanisms for the deposit formation and methods for the reduction of the deposits are proposed. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593355
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14279-14288[article] Formation and characterization of deposits in cyclone dipleg of a commercial residue fluid catalytic cracking reactor [texte imprimé] / Sung Won Kim, Auteur ; Ju Wook Lee, Auteur ; Jae Suk Koh, Auteur . - 2013 . - pp. 14279-14288.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14279-14288
Mots-clés : Reactor Fluid catalytic cracking Cyclone Résumé : Deposits in the cyclone dipleg of a commercial residue fluid catalytic cracking (RFCC) reactor, which are one of the primary problems causing abnormal shut-down of RFCC, were characterized using an analytical approach in order to understand the formation mechanism of the deposit. The main components of the deposits are hydrocarbons and a high portion of inorganic matter, reflecting dipleg conditions with particle flow. The deposit consists of two parts of massive bulk matter which are mainly pure Sb metal and catalyst particles surrounded by filamentous cokes and lumps of carbonaceous matters. Nickel nanopowders on the catalyst surface and from heavy oil in vapor phase catalyze the filament coke, which accelerate the increase in the amount of deposits by filtering heavy oil droplets. The Sb metals, originated from injected Ni passivator in the riser, contribute largely to deposit formation, and this is validated by a simulation of RFCC conditions and a calculation of cyclone collection efficiency. Possible mechanisms for the deposit formation and methods for the reduction of the deposits are proposed. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593355 Exemplaires
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Titre : Gas–solid flow and energy dissipation in inclined pneumatic conveying Type de document : texte imprimé Auteurs : S. B. Kuang, Auteur ; R. P. Zou, Auteur ; R. H. Pan, Auteur Année de publication : 2013 Article en page(s) : pp. 14289–14302 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Gas solid Résumé : This article presents a numerical study of inclined pneumatic conveying using the combination of the discrete element model (DEM) for the particles and computational fluid dynamics (CFD) for the gas. In the numerical model, periodic boundary conditions (PBCs) are applied to both gas and particles in the conveying direction for computational efficiency. The validity of the model is first examined by comparing the calculated and measured results in terms of solids flow rate and gas pressure drop during pneumatic conveying with a pipeline inclination angle varying from 0° to 90°. On this basis, the effects of inclination angle, solids flow rate, and gas velocity on gas pressure are quantified. The contributions of different forces including the particle–wall friction force, particle gravitational force, and fluid–wall friction force to the pressure drop are examined. Finally, the energy dissipation as a result of interactions between particles, between particles and wall, between particles and fluid, between fluids, and between fluid and wall is studied in detail. The results show that the energy loss during steady-state inclined pneumatic conveying can mainly be attributed to particle–fluid energy dissipation, gravitational potential energy, particle–wall friction energy dissipation, and fluid–wall viscous energy dissipation. These energy dissipations vary significantly with inclination angle and flow regime. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301894d
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14289–14302[article] Gas–solid flow and energy dissipation in inclined pneumatic conveying [texte imprimé] / S. B. Kuang, Auteur ; R. P. Zou, Auteur ; R. H. Pan, Auteur . - 2013 . - pp. 14289–14302.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14289–14302
Mots-clés : Gas solid Résumé : This article presents a numerical study of inclined pneumatic conveying using the combination of the discrete element model (DEM) for the particles and computational fluid dynamics (CFD) for the gas. In the numerical model, periodic boundary conditions (PBCs) are applied to both gas and particles in the conveying direction for computational efficiency. The validity of the model is first examined by comparing the calculated and measured results in terms of solids flow rate and gas pressure drop during pneumatic conveying with a pipeline inclination angle varying from 0° to 90°. On this basis, the effects of inclination angle, solids flow rate, and gas velocity on gas pressure are quantified. The contributions of different forces including the particle–wall friction force, particle gravitational force, and fluid–wall friction force to the pressure drop are examined. Finally, the energy dissipation as a result of interactions between particles, between particles and wall, between particles and fluid, between fluids, and between fluid and wall is studied in detail. The results show that the energy loss during steady-state inclined pneumatic conveying can mainly be attributed to particle–fluid energy dissipation, gravitational potential energy, particle–wall friction energy dissipation, and fluid–wall viscous energy dissipation. These energy dissipations vary significantly with inclination angle and flow regime. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie301894d Exemplaires
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Titre : COSMOquick : A novel interface for fast a-profile composition and its application to COSMO-RS solvent screening using multiple reference solvents Type de document : texte imprimé Auteurs : Christoph Loschen, Auteur ; Andreas Klamt, Auteur Année de publication : 2013 Article en page(s) : pp. 14303-14308 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Standard COSMO-RS Multiple reference solvents Résumé : We present a novel, simpler to use modification of the standard COSMO-RS solubility prediction scheme which in addition can achieve higher accuracy by the usage of multiple experimental reference solubilities. When only one reference solvent is used, the approach reduces to the original COSMO-RS-based solubility prediction. Considerable speedup and simplification compared to the original COSMO-RS arises from the usage of approximate σ-profiles generated from a database of COSMO-files from 65000 diverse molecules. This method enables fast and accurate solvent screening. Solubility predictions using the novel approach on pure solvents perform favorably when compared to NRTL-SAC calculations. The new method is accessible via a graphical user-interface (COSMOquick) and combines the reliability and broad applicability of COSMO-RS theory with some practical advantages of more empirical solubility models. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3023675
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14303-14308[article] COSMOquick : A novel interface for fast a-profile composition and its application to COSMO-RS solvent screening using multiple reference solvents [texte imprimé] / Christoph Loschen, Auteur ; Andreas Klamt, Auteur . - 2013 . - pp. 14303-14308.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14303-14308
Mots-clés : Standard COSMO-RS Multiple reference solvents Résumé : We present a novel, simpler to use modification of the standard COSMO-RS solubility prediction scheme which in addition can achieve higher accuracy by the usage of multiple experimental reference solubilities. When only one reference solvent is used, the approach reduces to the original COSMO-RS-based solubility prediction. Considerable speedup and simplification compared to the original COSMO-RS arises from the usage of approximate σ-profiles generated from a database of COSMO-files from 65000 diverse molecules. This method enables fast and accurate solvent screening. Solubility predictions using the novel approach on pure solvents perform favorably when compared to NRTL-SAC calculations. The new method is accessible via a graphical user-interface (COSMOquick) and combines the reliability and broad applicability of COSMO-RS theory with some practical advantages of more empirical solubility models. ISSN : 0888-5885 En ligne : http://pubs.acs.org/doi/abs/10.1021/ie3023675 Exemplaires
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Titre : Flash points of organosilicon compounds : How data for alkanes combined with custom additive fragments can expedite the development of predictive models Type de document : texte imprimé Auteurs : Didier Mathieu, Auteur Année de publication : 2013 Article en page(s) : pp. 14309-14315 Note générale : Industrial chemistry Langues : Anglais (eng) Mots-clés : Forecast model Additive Résumé : An especially simple approach to the evaluation of flash point (FP) from additive fragment contributions is outlined. Being based on a square root expression derived from the examination of n-alkanes data, it avoids the need for nonlinear fitting procedures and for trial-and-error optimization of the analytical relationship between FP and molecular descriptors. Furthermore, in spite of a specially small number of additive contributions, the method can be applied to most organic molecules. For organosilicon compounds, it exhibits some advantages compared to previously available procedures, while providing very similar performances, with an average absolute deviation from experiment close to 12 K, a determination coefficient R2 = 0.89 and only one error >40 K. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593358
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14309-14315[article] Flash points of organosilicon compounds : How data for alkanes combined with custom additive fragments can expedite the development of predictive models [texte imprimé] / Didier Mathieu, Auteur . - 2013 . - pp. 14309-14315.
Industrial chemistry
Langues : Anglais (eng)
in Industrial & engineering chemistry research > Vol. 51 N° 43 (Octobre 2012) . - pp. 14309-14315
Mots-clés : Forecast model Additive Résumé : An especially simple approach to the evaluation of flash point (FP) from additive fragment contributions is outlined. Being based on a square root expression derived from the examination of n-alkanes data, it avoids the need for nonlinear fitting procedures and for trial-and-error optimization of the analytical relationship between FP and molecular descriptors. Furthermore, in spite of a specially small number of additive contributions, the method can be applied to most organic molecules. For organosilicon compounds, it exhibits some advantages compared to previously available procedures, while providing very similar performances, with an average absolute deviation from experiment close to 12 K, a determination coefficient R2 = 0.89 and only one error >40 K. ISSN : 0888-5885 En ligne : http://cat.inist.fr/?aModele=afficheN&cpsidt=26593358 Exemplaires
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