Catalogue en ligne Bibliothèque Ecole Nationale Polytechnique d'Alger

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15293–15298

Titre :	Determination of the solubility parameter of ionic liquid 1-hexyl-3-methylimidazolium hexafluorophosphate by inverse gas chromatography
Type de document :	texte imprimé
Auteurs :	Yali Chen, Auteur ; Qiang Wang, Auteur ; Zhengfang Zhang, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15293–15298
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Gas chromatography Ionic liquid Solubility
Résumé :	In this study, physical and thermodynamic properties of 1-hexyl-3-methylimidazolium hexafluorophosphate ([HMIM]PF6) were investigated by using inverse gas chromatography (IGC). Two groups of solvents with different chemical natures and polarities were used to obtain information about [HMIM]PF6-solvent interactions: chloroform, ethyl acetate, ether, acetone and alkanes. The specific retention volume (Vg0), molar heat of sorption, weight fraction activity coefficient, activity coefficients at infinite dilution, partial molar heat of mixing and Flory–Huggins interaction parameter between [HMIM]PF6 and solvents were determined in the temperature range of 343.15–373.15 K. Also, the solubility parameters of [HMIM]PF6 at infinite dilution were found by plotting the graph of δ12/(RT) – χ1.2∞/V1 versus solubility parameters, δ1, of probes. The results showed that n-C6, n-C7, n-C8, n-C9, ether, and n-butyl alcohol were poor solvents for [HMIM]PF6; chloroform, acetone, and ethyl acetate were favorite ones, while ethanol was moderate solvent for [HMIM]PF6 (close to poor solvent). The solubility parameter of [HMIM]PF6 was determined as 23.28 (J/cm3)0.5 by the extrapolation at 298.15 K.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26679650

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15282–15292

Titre :	Mixing performance of the novel kar dynamic mixer impeller in small laboratory-scale systems
Type de document :	texte imprimé
Auteurs :	Zhao Yu, Auteur ; Richard F. Cope, Auteur ; Kishore K. Kar, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15282–15292
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Laboratory scale Agitator Mixer Mixing
Résumé :	Small (<100 mL) lab-scale systems for rapid screening are widely employed in research and development in chemistry and biology, but commonly encounter significant mixing challenges. Researchers from the Engineering and Process Sciences Laboratory of The Dow Chemical Company developed and patented a novel Kar Dynamic Mixer (KDM) impeller for overhead mixing within such unbaffled systems. This impeller consists of multiple twisted ribbon elements mounted on a rotating shaft. Through laboratory experiments and computational fluid dynamics (CFD) simulations, the performance of the KDM impeller was compared to that of vendor-offered impellers in three different lab-scale mixing systems. In fluid viscosities ranging from 5000 to 30 000 cP, the KDM impeller produced the desired mixing in significantly less time than each commercially offered impeller system. Experiments and simulations characterized KDM impeller operations and yielded the recommended ratios of KDM diameter-to-vial diameter (D/T), liquid submergence-to-KDM diameter (s/D), and off-bottom clearance-to-KDM diameter (c/D). The optimal speed at which the KDM impeller rotates depends on the fluid system of interest. The design of the KDM impeller was refined for the applications described in this work by optimizing the length-to-diameter ratio (L/D) of the impeller elements, as well as the number of repeated KDM elements so as to meet the recommended values of s/D, c/D, and L/D. Other crucial features of the optimized KDM design included twisting all elements in the same direction (be it clockwise or counter-clockwise), and the 90 degree offset angle between adjacent elements. The KDM impeller is well suited to laboratory scales, but its high relative mass could make it impractical at some larger scales, depending on fluids of interest and materials of construction. Identifying the size at which the KDM becomes impractical was beyond the current effort.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26679649

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15276–15281

Titre :	Rolling ball viscometer calibration with gas over whole interest range of pressure and temperature improves accuracy of gas viscosity measurement
Type de document :	texte imprimé
Auteurs :	Ehsan Davani, Auteur ; Gioia Falcone, Auteur ; Catalin Teodoriu, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15276–15281
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Viscosity Calibration
Résumé :	A practical method for measuring gas viscosity uses gas to calibrate the rolling ball viscometer over the whole interest range of pressure and temperature. It reduces the turbulent effect of gas flow around the ball. The viscometer calibration at only atmospheric pressure yields poor results, because it cannot accommodate the turbulent effect at higher pressures. We used nitrogen to calibrate the viscometer for the pressure up to 8,000 psia and temperature up to 260 °F. Optimal tube inclination angle and also ball/tube diameter ratio ensure the laminar flow around the ball and improve the accuracy of the results. Viscosity measurements of ultrapure CO2 confirmed this technique.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26679648

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15268-15275

Titre :	Flow pattern characteristics in vertical dense-phase pneumatic conveying of pulverized coal using electrical capacitance tomography
Type de document :	texte imprimé
Auteurs :	Xingliang Cong, Auteur ; Xiaolei Guo, Auteur ; Haifeng Lu, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15268-15275
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Tomography Capacitance Coal Pneumatic conveyance Dense phaseFlow field
Résumé :	Research on flow patterns can provide a better understanding of particle dynamics in dense-phase pneumatic conveying of pulverized coal. In this paper, electrical capacitance tomography (ECT) has been employed to study flow patterns in the 20 mm diameter vertical riser. Three flow patterns were identified on the basis of ECT image analysis, and their characteristics and formation mechanisms were discussed. The flow patterns at high solid concentration were more asymmetrical than those at low solid concentration. Solid concentration signals obtained from ECT were analyzed by different signal analysis methods including relative standard deviation (RSD), probability density function (PDF), and power spectral density function (PSD), which were verified to be effective enough to identify the characteristics of the different flow patterns. Additionally, the Bi model (Bi, H. T.; Grace, J. R. Int. J. Multiphase Flow 1995, 21, 1229-1239) was modified to effectively predict chocking velocity in the vertical dense-phase pneumatic conveying of pulverized coal.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26679647

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15258-15267

Titre :	Mixing of newtonian and non-newtonian fluids in a cylindrical mixer equipped with a side-entry impeller
Type de document :	texte imprimé
Auteurs :	Jaime Sossa-Echeverria, Auteur ; Fariborz Taghipour, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15258-15267
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Agitator Mixer Non Newtonian fluid Mixing
Résumé :	The effects of rheological properties on the mixing flow generated in a cylindrical tank equipped with a side-entry impeller were investigated using particle image velocimetry (PIV). Velocity vector maps were obtained from the laminar and transitional flow regimes of viscous Newtonian and non-Newtonian shear-thinning fluids with yield stress. Radical changes in the discharge angle were detected under the evaluated conditions. It was observed that radial discharge and a strong tangential flow arise when the viscous forces dominate the flow. Moreover, the impeller discharge is affected when the interaction between the flow and one of the walls of the vessel is significant; thus, the flow features are defined by the Reynolds number and the restrictions imposed by the walls of the tank.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26679646

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15251-15257

Titre :	Introducing a fast method to determine the solubility and metastable zone width for proteins : Case study lysozyme
Type de document :	texte imprimé
Auteurs :	Somchai Maosoongnern, Auteur ; Viviana Diaz Borbon, Auteur ; Adrian E. Flood, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15251-15257
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Solubility
Résumé :	The phase diagrams of tetragonal hen egg white lysozyme containing besides thermodynamic (solubility) also kinetic (nucleation) data were determined for pH values of 4.4, 5.0, and 6.0, 3 to 7 wt % sodium chloride concentrations and lysozyme concentrations from 5 to 70 mg/mL by the use of a turbidity technique. This new technique offers a rapid, precise and reliable determination of nucleation and solubility points. These points can be obtained simultaneously within 6 h. The errors of measurements are less than ±0.9 °C for the solubility temperature and less than ±1.0 °C for the nucleation temperature. The solubility data obtained could be extended and described by a good correlation with literature data. The solubility of lysozyme was found to decrease with increasing salt concentration while the nucleation points were observed more early with respect to salt addition; as a consequence the metastable zone is more narrow. The solubility of lysozyme is slightly reduced at higher values of the pH, and the nucleation point is observed later in time. The result is an increase of the metastable zone width.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26679645

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15242-15250

Titre :	Studies on Cr(VI) removal from aqueous solutions by nanoalumina
Type de document :	texte imprimé
Auteurs :	Madona Lien Paul, Auteur ; Jastin Samuel, Auteur ; Sushree Bedatrayee Das, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15242-15250
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Aqueous solution
Résumé :	The current study deals with Cr(VI) removal using unmodified alumina nanoparticles of two different sizes (NA1: mean hydrodynamic diameter = 75.3 ± 2.8 nm; NA2: mean hydrodynamic diameter = 229.8 ± 3.3 nm). The equilibrium adsorption capacities, 73.2 and 59.4 mg of Cr(VI)/g of adsorbent, were noted for NA1 and NA2, respectively, under optimized conditions (pH 7.0, temperature = 27 °C, initial Cr(VI) concentration = 20 mg L―1, adsorbent dosage = O.lg L―1) but different contact times (120 min for NA1, 180 min for NA2). For both sorbents, the equilibrium adsorption data fitted well with the Langmuir isotherm model. The adsorbent NA1 followed a pseudo-second-order kinetics, whereas NA2 followed pseudo-first-order kinetics. Surface characterization studies (zeta potential measurement, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDX), and Fourier transform infrared (FTIR) spectroscopy) substantiated oxyanionic binding on the sorbent surface. The EPR and XRD spectroscopy confirmed the existence of reduced Cr(III) on the adsorbent surface. The applicability of the sorbent in Cr(VI)-contaminated water was studied.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26679644

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15233-15241

Titre :	Experimental and model study on enantioselective extraction of phenylglycine enantiomers with BINAP–metal complexes
Type de document :	texte imprimé
Auteurs :	Kewen Tang, Auteur ; Guohui Wu, Auteur ; Panliang Zhang, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15233-15241
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Enantiomer Modeling
Résumé :	Enantioselective extraction of phenylglycine (PHG) enantiomers with (S)-BINAP―metal complexes as chiral selector was investigated. A reactive extraction model was established to interpret the experimental data. The complexation equilibrium constants and other important parameters required by the model were determined experimentally. The extraction system shows good selectivity toward PHG enantiomers. The complex [(S)-BINAP(CH3CN)Cu][PF6] (BINAP-Cu) exhibits the highest selectivity among the selectors studied, which is dissolved in the organic phase and preferentially extracts L-PHG from aqueous phase. Efficiency of extraction depends, often strongly, on a number of process variables, including types of organic solvents and metal precursors, concentration of selector, pH, and temperature. The model quantitatively predicts extraction performance as a function of key operating parameters, providing a simple computational approach to process optimization. The model was verified experimentally with excellent results.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26679643

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15224–15232

Titre :	Silica-based 2-aminomethylpyridine functionalized adsorbent for hydrometallurgical extraction of low-grade copper ore
Type de document :	texte imprimé
Auteurs :	Xin Li, Auteur ; Baohua Li, Auteur ; Shan Wu, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15224–15232
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Adsorbent Hydrometallurgical
Résumé :	A silica-based 2-aminomethylpyridine functionalized adsorbent was synthesized to extract copper. Characterization of the adsorbent was carried out to determine the surface morphology, specific surface area, pore size, and grafting ratio of 2-aminomethylpyridine groups. The adsorption selectivity of the adsorbent for Cu(II) ions was 1353 times higher than that for Fe(III) ions. The adsorption capacity for Cu(II) ions maintained a stable value of 0.53 mmol/g with and without perturbation of Fe(III) ions. Density functional theory (DFT) calculations revealed a mechanism of selective adsorption of copper, through the formation of 2-aminomethylpyridine-Cu(II) complexes. Semi-industrial scale experiments revealed that Cu(II) ions in the acidic leachate of low-grade copper ore could be efficiently extracted by the adsorbent even in perturbation of substantial amounts of Fe(III) and other metal ions. Based on the adsorbent, a new process for copper hydrometallurgical extraction was developed, in which the adverse environmental impacts in traditional solvent extraction processes could be avoided.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301852r

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15217–15223

Titre :	U-Shaped BaCo0.7Fe0.2Ta0.1O3 − δ hollow - fiber membranes with high permeation for oxygen separation
Type de document :	texte imprimé
Auteurs :	Qing Liao, Auteur ; Qin Zheng, Auteur ; Jian Xue, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15217–15223
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Hollow fiber membrane
Résumé :	Dense perovskite hollow-fiber membranes based on BaCo0.7Fe0.2Ta0.1O3−δ (BCFT) are prepared by a phase inversion spinning process. The thermal cycling performance and the dependences of oxygen permeation on the air flow rate on the shell side, the helium flow rate on the core side, the oxygen partial pressures, and the operating temperatures are experimentally investigated. The oxygen transport through the U-shaped hollow-fiber membrane is controlled by both surface reaction and bulk diffusion at the temperature ranges of 750–950 °C, whereas the oxygen permeation is predominantly controlled by the surface reaction at 700 °C. X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses of the spent hollow-fiber membrane after oxygen permeation for 250 h show the good stability of the U-shaped BCFT hollow-fiber membrane.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301789t

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15207–15216

Titre :	Transportation of catechin (±C) using physiologically benign vegetable oil as liquid membrane
Type de document :	texte imprimé
Auteurs :	Mriganka Sekhar Manna, Auteur ; Kamal Kumar Bhatluri, Auteur ; Prabirkumar Saha, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15207–15216
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Vegetable oil Liquid membrane
Résumé :	This paper presents an experimental study on the simultaneous extraction and recovery of catechin through bulk liquid membrane (BLM). Various environmentally benign solvents, namely vegetable oils, have been used as liquid membrane along with various transport-enhancing carrier agents to identify the best solute–carrier combination that would yield optimum performance of the BLM. Tributyl phosphate (TBP) (carrier) in sunflower oil (SFO) (solvent) is found to be the best among the tested combinations. Initially two-phase (feed–membrane) equilibrium studies have been carried out in order to study the effects of operating conditions, namely pH, temperature, initial feed concentration, and carrier concentration, on the equilibrium distribution. Based on these results, simultaneous extraction and recovery of the catechin have been carried out in a BLM type liquid membrane configuration using ethanol as the stripping agent and the optimum operating conditions are redefined accordingly. Seventy percent extraction and 44% recovery of the catechin have been achieved respectively at the optimum conditions of the parameters namely 0.36 M TBP in the membrane phase, 0.2 M ethanol as stripping agent, 400 rpm stirring speed, and 25 °C temperature from an initial aqueous feed of 4.0 pH and 100 mg L–1 concentration. Maximum fluxes of the extraction and recovery were found as 5.7 × 10–9 g cm–2 s–1 and 4.9× 10–9 g cm–2 s–1, respectively.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3017863

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15193-15206

Titre :	Solubility and modeling of sodium aluminosilicate in NaOH–NaAl(OH)4 solutions and its application to desilication
Type de document :	texte imprimé
Auteurs :	Lanmu Zeng, Auteur ; Zhibao Li, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15193-15206
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Modeling Solubility
Résumé :	The solubility of sodium aluminosilicate (sodalite), a major desilication product (DSP) in the Bayer process, in NaOH and NaOH―NaAl(OH)4 solutions was determined and modeled at temperatures from 303.2 to 348.2 K. Sodium aluminosilicate was synthesized in a batch crystallizer and the effect of temperature, solution concentrations, and aging time was investigated. Solubility was found to increase with increasing NaOH concentration while the solubility sharply decreases with the addition of Al(OH)3, reaches a minimum at about 0.8 mol·L―1, and then increases. A mixed-solvent electrolyte (MSE) model for the solubility of sodalite was developed with the help of the OLI platform via regression to obtain the model parameters. In addition, the desilication kinetics of NaOH―NaAl(OH)4 solutions by using sodalite as seeds was studied experimentally and modeled with the aid of a second order kinetic model. The activation energy of desilication over the temperature range 323.2― 363.2 K was found to be 92 ± 14 kJ·mol―1. Under the optimal operation conditions, 80% silica was removed after 2 h.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26679639

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15184-15192

Titre :	Separation of Bi(III) and Sb(III) from Cu(II) HCl/H2SO4 mixed media by supported liquid membranes using cyanex 921 as carrier
Type de document :	texte imprimé
Auteurs :	Luis A. Santiago-Santiago, Auteur ; J. Antonio Reyes-Aguilera, Auteur ; M. P. Gonzalez, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15184-15192
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Membrane separation Supported liquid membranes
Résumé :	We present a systematic study of the separation of Bi(III) and Sb(III) contained in acidic HCl/H2SO4 aqueous solutions of Cu(II), by SLM, using Cyanex 921 as carrier. The transfer of Sb(III), Bi(lII) and Cu(II) was evaluated in order to determine the efficiency and selectivity of the specific SLM developed. Using a polyvinylidene fluoride (PVDF) microporous membrane impregnated with Cyanex 921, as SLM, we studied the influence of the characteristics of the stripping solution and the effect of temperature on the membrane efficiency and stability. Recovery rates of Sb(III) and Bi(III) were close to 99%, while Cu(II) was barely transferred into the stripping solution.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301447x

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15176-15183

Titre :	Active vapor split control for dividing-wall columns
Type de document :	texte imprimé
Auteurs :	Deeptanshu Dwivedi, Auteur ; Jens P. Strandberg, Auteur ; Ivar J. Halvorsen, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15176-15183
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Distillation columns Energy
Résumé :	Dividing-wall distillation columns offer large potential energy savings over conventional column sequences, typically up to 30% for three-product (Petlyuk) columns and 40% for four-product (Kaibel) columns. However, the energy required for a separation depends on using an optimal vapor split. Hence, the energy saving potential may be lost if the column is operated away from its optimal point, for example, due to feed composition changes. This work demonstrates experimentally that the vapor split can be effectively used as a degree of freedom during operation, for example, for temperature control in the prefractionator section. Together with an adjustable liquid split, the vapor split control allows for minimizing the energy requirements.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3014346

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp.15170–15175

Titre :	Washing of uranyl nitrate hexahydrate crystals with nitric acid aqueous solution to improve crystal quality
Type de document :	texte imprimé
Auteurs :	Masaumi Nakahara, Auteur ; Yasuo Nakajima, Auteur ; Tsutomu Koizumi, Auteur
Année de publication :	2013
Article en page(s) :	pp.15170–15175
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Nitrate Crystals
Résumé :	To develop a uranium crystallization process for advanced aqueous reprocessing, two method experiments were investigated to evaluate the effect of crystal washing on uranyl nitrate hexahydrate (UNH). In one experiment, crystal washing was carried out using a uranyl nitrate solution with varying concentrations of HNO3 in washing solutions, and in the other, it was conducted with a dissolver solution of the irradiated fast neutron reactor core fuel. In the crystal washing experiments with the uranyl nitrate solution, the UNH crystals were immersed into a uranyl nitrate solution containing Ce, which was washed out in the mother liquor on the surface of the UNH crystals using an HNO3 solution. The experimental results showed that the decontamination factor (DF) of Ce increased with decreasing HNO3 concentration of the washing solution. However, because the UNH crystals tended to dissolve in low HNO3 concentration solutions, the yield decreased as a result of the washing operation. In the crystallization experiment using a dissolver solution derived from the irradiated fast neutron reactor core fuel, the DFs of the liquid impurities for the UNH crystals were improved with each crystal washing. However, their values approached a constant value because the inclusions within the UNH crystal were not removed by the crystal washing operation. On the other hand, solid impurities such as Cs2Pu(NO3)6 and Ba(NO3)2 remained in the UNH crystals after several crystal washing operations.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3013067

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15163–15169

Titre :	AM-TEPA impregnated disordered mesoporous silica as CO2 capture adsorbent for balanced adsorption–desorption properties
Type de document :	texte imprimé
Auteurs :	Xiaoyun Zhang, Auteur ; Xiuxin Zheng, Auteur ; Sisi Zhang, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15163–15169
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Mesoporous silica
Résumé :	A disordered mesoporous silica was found to be a promising solid support for CO2 capture. It was prepared with a process similar to that for MCM-41. X-ray diffraction characterization (XRD) and transmission electron microscopy (TEM) confirmed its disordered structure. N2 adsorption–desorption tests indicated that its average pore size is significantly larger than that of MCM-41. On this support was deposited acrylamide (AM)-modified tetraethylenepentamine (TEPA), resulting in an adsorbent suitable for CO2 capture. This material exhibited well balanced adsorption and desorption properties. Substantially higher CO2 adsorption capacity (159.1 mg/g-adsorbent) was obtained with pure CO2 at 25 °C, and satisfactory stability during 12 adsorption–desorption turnovers was achieved.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300180u

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15153-15162

Titre :	Dynamics of CO2 adsorption on amine adsorbents. 2. : Insights into adsorbent design
Type de document :	texte imprimé
Auteurs :	Praveen Bollini, Auteur ; Nicholas A. Brunelli, Auteur ; Stephanie A. Didas, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15153-15162
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Design Adsorption Carbon dioxide
Résumé :	Packed bed breakthrough experiments are reported for commercial zeolite 13X and 3-aminopropyl-functionalized SBA-15 silica materials with three different amine loadings. Mass and heat transfer dynamics for all four materials are modeled successfully. Amine adsorbents with open pores are found to exhibit faster mass diffusion rates compared to zeolite 13X. When amine loading is increased by coupling aminopropyl groups, premature breakthrough combined with a long tail is observed. Contrary to conventional physisorbants, finite heat losses to the column wall do not explain the long breakthrough tail. A rate model that accounts for heterogeneity in diffusion was found to accurately capture the breakthrough shape of the high loading material. Batch uptake measurements support the hypothesis that slow diffusion through the polymer phase is what hampers adsorption kinetics in the high amine loading adsorbent. The results emphasize the importance of designing materials that are not overloaded with amine sites, as excessive amine loadings can lead to depressed adsorption kinetics and premature column breakthrough.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26679634

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15145-15152

Titre :	Dynamics of CO2 adsorption on amine adsorbents. 1. : Impact of heat effects
Type de document :	texte imprimé
Auteurs :	Praveen Bollini, Auteur ; Nicholas A. Brunelli, Auteur ; Stephanie A. Didas, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15145-15152
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Adsorption Carbon dioxide
Résumé :	The packed bed heat and mass transfer dynamics of CO2 adsorption onto a 3-aminopropylsilyl-functionalized SBA-15 silica material are reported. Concentration measurements at the outlet of the packed bed and temperature profiles inside the bed are measured simultaneously. Heat and mass transfer models in conjunction with the linear driving force rate model are used to simulate the concentration and temperature profiles in the bed. The heat and mass transfer processes in the amine adsorbent packed bed are successfully captured by the model, and comparison of isothermal and nonisothermal models reveals that isothermal models provide an accurate description of the dynamic mass transport behavior in the adsorption column under the experimental conditions used in this study. The results help establish that under certain experimental conditions, heat effects in amine adsorbent packed beds have a negligible effect on CO2 breakthrough, and simple isothermal models can be used to accurately assess adsorption kinetics.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26679633

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15132-15144

Titre :	A CFD modeling approach to design a new gas barrier in a multizone circulating polymerization reactor
Type de document :	texte imprimé
Auteurs :	Wei-Cheng Yan, Auteur ; Guo-Qiang Chen, Auteur ; Zheng-Hong Luo, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15132-15144
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Polymerization reactor Design ModelingComputational fluid dynamics
Résumé :	In this work, the CFD modeling approach, which is an old approach in chemical engineering, is extended to the propylene polymerization process in a multizone circulating reactor (MZCR) in order to design a new gas-barrier system in the MZCR from the fluid-dynamics viewpoint. First, the CFD modeling approach based on an Eulerian-Eulerian model, incorporating a kinetic theory of granular flow, is applied to describe the gas―solid flow in a polypropylene MZCR. Furthermore, the modeling approach is used to obtain important operation data of the gas-barrier inlet and to optimize the gas-barrier inlet configuration. Accordingly, the entire field in the MZCR with the optimal gas-barrier system above is predicted. The simulation results show that the four-way tangential gas-barrier configuration is suitable in the MZCR, which is the first use of a gas-barrier inlet that allows an optimal flow field in the MZCR. This article has reported an old approach in chemical engineering that has been applied to a new field for the purpose of designing a new gas barrier, which opens up a new research field in the olefin polymerization process.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26679632

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15122–15131

Titre :	Carbon dioxide liquefaction process for ship transportation
Type de document :	texte imprimé
Auteurs :	Ung Lee, Auteur ; Seeyub Yang, Auteur ; Yeong Su Jeong, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15122–15131
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Liquefaction process
Résumé :	CO2 liquefaction is an essential process for long-distance ship transportation. The conventional CO2 liquefaction process employs either an external coolant or liquid expansion followed by multistage compression to obtain liquefied CO2 at low pressure. However, these processes consume considerable amounts of energy, which presents an obstacle to commercialization. Thus, the CO2 liquefaction process needs to be carefully researched and designed to reduce the operating energy. In this study, two alternative CO2 liquefaction processes are proposed and evaluated. These alternative processes use multistage expansion and multistream heat exchangers to lower the input stream temperature for the compressor. In addition, the system is operated in a more efficient manner by operating the process with an optimized compression ratio. Evaluation of the economic feasibility was performed in this study for a complete assessment of the alternative processes. As a result, about 98.1 kWh/t of CO2 was consumed for alternative process 2, which is only 91.8% of the total operating energy of existing CO2 liquefaction processes, and the CO2 liquefaction costs for alternative process 2 were reduced by 5.5%.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300431z

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15109-15121

Titre :	Effect of chemical and physical cross-linking on tensile characteristics of solution-blown soy protein nanofiber mats
Type de document :	texte imprimé
Auteurs :	S. Sinha-Ray, Auteur ; S. Khansari, Auteur ; A. L. Yarin, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15109-15121
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Nanofiber
Résumé :	Solution-blown soy protein/nylon 6 nanofibers, 40/60 and 50/50 wt/wt %, were collected on a rotating aluminum drum in order to form a mat. The collected fiber mats were bonded both chemically (using aldehydes and ionic cross-linkers) and physically (by means of wet and thermal treatment) to increase the tensile strength to increase the range of application of such green nonwovens. Chemical cross-linkers bond different amino groups, primary amides, and sulfhydryl groups in protein structure. This is beneficial for the enhancement of tensile strength. Such mechanical properties of soy-protein-containing nanofiber mats as Young’s modulus, yield stress, and maximum stress and strain at rupture were measured for different cross-linkers at different contents. Overall, higher contents of cross-linking agents in soy protein nanofiber mats resulted in nanofibers with higher strength which was accompanied by a less plastic behavior. Treatment with ionic cross-linkers resulted in nanofiber mats with higher Young’s modulus of the mats. Covalent bonds formed by aldehyde groups had a smaller effect on the mat strength. As cross-linked nanofibers were exposed to heat, the bonds formed between amino groups in the fibers were broken and they became less aggregated. The overall increase of about 50% in tensile strength as a result of thermal bonding under compression was observed. In addition, wet conglutination of soy protein/nylon 6 nanofiber mats for 24 h under 6 kPa pressure led to partial physical cross-linking of nanofibers and, consequently, to a 65% increase in Young’s modulus. Solution-blown soy protein/nylon 6 nanofiber mats were also subjected to aging in water for 1 h at 80 °C. An enhancement in the tensile strength of soy protein nanofiber mats was revealed after the exposure to water, as well as a slight plasticizing effect.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie302359x

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15096-15108

Titre :	Exfoliated and optically transparent polycarbonate/clay nanocomposites using phosphonium modified organoclay : Preparation and characterizations
Type de document :	texte imprimé
Auteurs :	Supratim Suin, Auteur ; Bhanu B. Khatua, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15096-15108
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Preparation Nanocomposite
Résumé :	This investigation deals with the morphology and properties of polycarbonate (PC)/clay nanocomposites prepared by melt-blending and solution-blending, using benzyltriphenylphosphonium modified montmorillonite (BTPP+-MMT) clay. Isothermal thermogravimetric analysis of the BTPP+-MMT at 280 °C revealed higher stability of the BTPP+-MMT clay against thermal degradation at the processing temperature of PC. Wide angle X-ray diffraction, transmission electron microscopy, and rheological studies indicated the presence of highly delaminated clay silicate layers in PC/BTPP+-MMT nanocomposites. A slight increase in glass transition temperature (Tg) of PC in the nanocomposites suggested the presence of an attractive interaction of PC chains with the clay silicates in the nanocomposites. The tensile strength and modulus of PC was increased with increasing content of clay in the nanocomposites. However, at certain clay loading, tensile strength and Young modulus of the melt-blended BTPP+-MMT nanocomposites were significantly higher than that of the solution-blended nanocomposites, indicating better dispersion and distribution of the clay silicates in melt-blended nanocomposites.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26679629

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15089–15095

Titre :	Adsorption of the uranyl ions on an amidoxime-based polyethylene nonwoven fabric prepared by preirradiation-induced emulsion graft polymerization
Type de document :	texte imprimé
Auteurs :	Xiyan Liu, Auteur ; Hanzhou Liu, Auteur ; Hongjuan Ma, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15089–15095
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Uranyl ions
Résumé :	A polyethylene (PE) nonwoven fabric adsorbent with amidoxime (AO) groups denoted as PE-g-PAO is prepared by preirradiation-induced emulsion graft polymerization of acrylonitrile (AN) and subsequent amidoximation of the nitrile groups of the poly(acetonitrile) (PAN) grafting chains with hydroxylamine (NH2OH). The chemical structure, thermal stability, and mechanical intensity are evaluated by means of Fourier transform infrared, thermogravimetric analysis, differential scanning calorimetry, and tensile tests, respectively. The adsorption behavior of the uranyl ions in low initial concentrations over a range of 3–50 μg/L on the PE-g-PAO nonwoven fabric is studied by the batch technique at a pH value of 7.5 at different temperatures. It can be found that the temperature induces a positive effect on the adsorption process and the adsorption capacity increases with an increase of the uranyl ion initial concentration. The adsorption data obtained under the corresponding conditions are correlated with the pseudo-first-order and pseudo-second-order kinetic and Freundlich isotherm models, respectively.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301965g

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15082-15088

Titre :	Investigation of thermal and combustion properties for intumescent flame-retardant ethylene–viny acetate composites containing ferrous disulfide
Type de document :	texte imprimé
Auteurs :	Lei Wang, Auteur ; Yuan Hu, Auteur ; Lei Song, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15082-15088
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Composite material Flame retardant Combustion
Résumé :	Ferrous disulfide (FeS2) nanocrystals were synthesized via a simple hydrothermal reaction. The FeS2 nanocrystals were then combined in intumescent flame-retardant ethylene―vinyl acetate (EVA/IFR) systems. Thermogravimetric analysis data indicate that the addition of FeS2 into the EVA/IFR composite can improve the char yields. Cone calorimeter results reveal that FeS2 and IFR can clearly change the decomposition behavior of EVA and form a char layer on the surface of the composites, consequently resulting in efficient reduction of the flammability parameters, such as the heat release rate, total heat release, and so on. Moreover, significant improvements are obtained in the limited oxygen index and Underwriters Laboratories 94 ratings. Laser Raman spectroscopy of residual char shows that the ordered carbon is increased with the addition of FeS2. Scanning electron microscopy demonstrates that FeS2 can help the EVA/IFR system form a dense char layer. The results of dynamic mechanical thermal analyses reveal that FeS2 can increase the glass transition temperature and the storage modulus of EVA/IFR. The mechanism is also proposed in this paper.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26679627

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15075-15081

Titre :	Novel method for preparing activated carbons with high specific surface area from rice husk
Type de document :	texte imprimé
Auteurs :	Xiaolan Song, Auteur ; Ying Zhang, Auteur ; Caimin Chang, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15075-15081
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Vegetal waste Rice by product Specific surface area Activated carbon
Résumé :	This study reports the novel dry activation for preparing activated carbon with a high specific surface area from rice husks using solid NaOH. Materials were characterized by N2 adsorption, X-ray diffraction, infrared spectroscopy, and scanning electron microscopy. The effects of mass ratio (1―4) and the activation process (dry activation or impregnation) on the surface area were studied, explicating the mechanism of pore development. With a mass ratio of 3, carbons prepared by dry activation possessed a much higher surface area of 2841 m2/g than the 933 m2/g for impregnation. For the adsorption of phenol, their maximum adsorption capacities were 351.4 and 160.8 mg/g, fitting with the Langmuir model. In addition, the economic analysis estimated a significant gross profit margin of 40.2% for the product. Therefore, it is demonstrated that dry activation is an effective and convenient method for obtaining low cost activated carbon with outstanding surface area.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26679626

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15064-15074

Titre :	Novel cyclolinear cyclotriphosphazene-linked epoxy resin for halogen-free fire resistance : Synthesis, characterization, and flammability characteristics
Type de document :	texte imprimé
Auteurs :	Yongwei Bai, Auteur ; Xiaodong Wang, Auteur ; Dezhen Wu, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15064-15074
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Flammability Fire resistance
Résumé :	A novel halogen-free flame-retardant epoxy resin was designed by introducing phosphazene rings into the backbone in a cyclolinear-linked mode, and then it was synthesized through a three-step synthetic route. The chemical structures and compositions of all the cyclotriphosphazene precursors and the final product were confirmed by 1H and 31P NMR spectroscopy, elemental analysis, and Fourier transform infrared spectroscopy. The thermal curing behaviors of the synthesized epoxy resin with dicyandiamide, 4,4'-diaminodiphenylmethane, and novolak as hardeners were investigated by differential scanning calorimetry (DSC), and the thermal properties were also evaluated by DSC and thermogravimetric analysis. These thermosets achieved high glass transition temperatures over 150 °C and simultaneously displayed good thermal stability with high char yields. Moreover, these thermosets have higher tensile and flexural strength but lower impact toughness in comparison with the conventional epoxy thermosets. The flammability characteristics of the thermosets obtained by curing this epoxy with three hardeners were studied on the basis of the limiting oxygen index (LOI) and UL―94 vertical burning experiments as well as the analysis of residual chars of the tested bars after vertical burring. The high LOI values and the V―0 classification for these epoxy thermosets indicate that the incorporation of phosphazene rings into the molecular backbone imparts flame retardancy on the epoxy resin. This may result from a unique combination of phosphorus and nitrogen in the phosphazene ring. The epoxy resin synthesized in this study is a green functional polymer and may become a potential candidate for fire- and heat-resistant applications in electronic and microelectronic fields.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26679625

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15053-15063

Titre :	Modeling the lignin degradation kinetics in a ethanol/formic acid solvolysis approach. Part 2. : Validation and transfer to variable conditions
Type de document :	texte imprimé
Auteurs :	Daniel Forchheim, Auteur ; James R. Gasson, Auteur ; Ursel Hornung, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15053-15063
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Kinetics Modeling
Résumé :	A formal kinetic model treating the depolymerization and hydrodeoxygenation of wheat straw lignin in ethanol with formic acid as hydrogen source developed by Gasson et al. [Gasson et al. Ind. Eng. Chem. Res. 2012, 51 (32), 10595-10606J is validated and its applicability in a continuous stirred tank reactor (CSTR) at varying temperatures between 633 K and 673 K is tested. The fitted formal kinetic rate coefficients are compared and sensitivity and flux analyses are performed. Activation energies are estimated for the lumped reactions. The depolymerization to primary products is considerably accelerated when transferring the reaction from batch to a continuous operation. Higher heating rates and continuous feeding of the hydrogen donor formic acid aid in suppressing both gas and char production. Repolymerization of intermediate phenolic compounds is suppressed, which is suggested to be due to the interaction of intermediate and final products. The evaluation shows that a continuous system can aid in avoiding further gasification and charring of the intermediate products in this one-step lignin depolymerization deoxygenation reaction for the production of a phenol-rich bio-oil.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26679624

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15041-15052

Titre :	Experiments and kinetic modeling for CO2 gasification of indian coal chars in the context of underground coal gasification
Type de document :	texte imprimé
Auteurs :	Ramesh Naidu Mandapati, Auteur ; Sateesh Daggupati, Auteur ; Sanjay M. Mahajani, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15041-15052
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Modeling Coal Coal gasification Carbon dioxide Kinetic model
Résumé :	Gasification of four Indian coals is carried out in a CO2 atmosphere, using a thermogravimetric analyzer (TGA) to determine the intrinsic kinetics over a temperature range of 800―1050 °C with different partial pressures of CO2. The applicability of three models, viz., the volumetric reaction model, the shrinking core model and the random pore model, is evaluated. Of these three models, the random pore model is found to be the most suitable for all the coals considered in the current study. The dependence of the reaction rate on the gas-phase partial pressures is explained by the Langmuir― Hinshelwood model, and the parameters for the inhibition due to CO and CO2 are determined by performing experiments at different partial pressures. In underground coal gasification, the reaction takes place on reasonably large sized coal particles, wherein diffusion effects are significant. A one-dimensional reaction diffusion model is therefore developed in order to determine the diffusional resistance in the coal particle, and values of diffusivity are estimated.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26679623

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15032-15040

Titre :	Fundamentals of petroleum residue cracking gasification for coproduction of oil and syngas
Type de document :	texte imprimé
Auteurs :	YuMing Zhang, Auteur ; Deping Yu, Auteur ; Wangliang Li, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15032-15040
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Synthesis gas Gasification Cracking Petroleum
Résumé :	Vacuum residue (VR) was stepwise converted via catalytic cracking for liquid and coke gasification for hydrogen-rich syngas in a fluidized bed reactor. Silica sand and spent equilibrium FCC (E-FCC) catalyst were used as the catalysts for VR cracking. The liquid yield was about 89 wt % at 568 °C using silica sand as catalyst and the conversion ratio of heavy fractions was only 55%. About 60 wt % VR was converted into gas and coke over the E-FCC catalyst at 480 °C, showing that the catalyst had too strong acidity for VR cracking. The E-FCC catalyst was thus modified (aged) with both hydrothermal treatment and impregnation of alkali and alkaline-earth metals (K and Mg) to weaken its acidity and facilitate the liquid oil production. The aged FCC (A-FCC) catalyst exhibited appropriate cracking activity to allow both the expected liquid yield of about 80 wt % and heavy fraction conversion ratio of up to 98 wt %. Steam gasification of the deposited coke on the surface of the A-FCC catalyst resulted in the production of syngas containing CO and H2 content to be about 45 and 42 vol %, respectively.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26679622

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15011-15017

Titre :	Model development and validation of ethyl tert-butyl ether production reactors using industrial plant data
Type de document :	texte imprimé
Auteurs :	Luís Domingues, Auteur ; Carla I. C. Pinheiro, Auteur ; Nuno M. C. Oliveira, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15011-15017
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Reactor Production Modeling
Résumé :	This work considers the development and validation of a first-principles dynamic model for the production of ethyl tert-butyl ether (ETBE) in the presence of the coproducts diisobutene (DIB) and tert-butyl alcohol (TBA). Desulfonation is assumed to be the main deactivation mechanism of the catalyst used, an acidic ion-exchange resin. Operational data from an industrial ETBE production plant, taken over the period of 1 year, were used to estimate both the deactivation and DIB kinetic constant parameters. A data reconciliation strategy was employed to convert the raw data into a consistent data set, representing the most likely process operation data. The parameters estimated were incorporated in a set of detailed mass and energy balances, together with additional kinetic and physical information from the literature, to originate a distributed parameter model capable of accurately describing the operation of two industrial reactors used for the production of ETBE. Model development and validation were performed in gPROMS Modelbuilder with the necessary physical properties calculated by Aspen Plus, through the CAPE-OPEN standard. The desulfonation decay order obtained was close to second order kinetics, previously proposed by other authors. The activation energy estimated for the desulfonation process was also comparable with past reported values, while the value of the pre-exponential factor for the desulfonation was slightly lower. Different temperature ranges and particle sizes are attributed as possible causes for the differences observed.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26679621

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15011-15017

Titre :	Axial dispersion based on the residence time distribution curves in a millireactor filled with β-SiC foam catalyst
Type de document :	texte imprimé
Auteurs :	Meryem Saber, Auteur ; Cuong Pham-Huu, Auteur ; David Edouard, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15011-15017
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Catalyst foam Residence time distribution Axial mixing
Résumé :	The hydrodynamics of the platelet millireactor filled with different morphologies of the commercial open cell β-SiC foams (0.8 < porosity (ε) < 0.95 and 890 μm < cell size (Φ) < 2700 μm) has been investigated. The axial dispersion profile of an inert tracer in a gas flow (superficial velocity from 0.01 to 0.3 m/s) is estimated by a robust deconvolution procedure. The axial Peclet number based on Φ is found to be on the order of 1. The results are in agreement with the literature data and can be compared with the available results for the standard fixed bed.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26679620

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 15004-15010

Titre :	Pd–Pb/SDB bimetallic catalysts for the direct oxidative esterification of methacrolein to methyl methacrylate
Type de document :	texte imprimé
Auteurs :	Baohe Wang, Auteur ; Wenjuan Sun, Auteur ; Jing Zhu, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15004-15010
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Esterification Oxidation Catalyst
Résumé :	Pd―Pb/SDB catalyst prepared by depositing lead and palladium on hydrophobic styrene-divinylbenzene (SDB) copolymer constitutes a new and highly efficient catalyst for the oxidative esterification of methacrolein with methanol to methyl methacrylate under mild conditions. Compared to the monometallic Pd/SDB catalyst and conventional hydrophilic catalysts supported on γ-Al2O3, the Pd―Pb/SDB bimetallic catalyst shows higher reaction rate and product selectivity. The Pd―Pb/SDB catalyst was prepared by impregnating method and characterized by N2 adsorption-desorption isotherm, X-ray diffraction (XRD), environmental scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The results showed that Pd―Pb atoms formed intermetallic Pd3Pb1 crystals and the active component had a better dispersion and a smaller particle size than Pd/SDB. The SDB-supported catalyst could be recycled easily and reused, even up to seven cycles, without any appreciable loss efficiency. Based on the experimental results, the potential reaction mechanism was also proposed.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26679619

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 14994–15003

Titre :	Production of benzene polycarboxylic acids from lignite by alkali-oxygen oxidation
Type de document :	texte imprimé
Auteurs :	Wenhua Wang, Auteur ; Yucui Hou, Auteur ; Weize Wu, Auteur
Année de publication :	2013
Article en page(s) :	pp. 14994–15003
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Polycarboxylic Acids
Résumé :	The oxidation of coal to produce high-valued benzene polycarboxylic acids (BPCAs), which are obtained currently from diminishing petroleum reserves, is a promising industrial process of the future. Up to now, the yield distribution of BPCAs has not been studied in detail and the mechanism of coal oxidation to BPCAs remains unclear. In this study, Huolinhe lignite was oxidized in a batch reactor by alkali-oxygen oxidation. All 12 kinds of BPCAs obtained were quantified by a new established method. Effects of alkali/coal mass ratio, reaction temperature, initial oxygen pressure, and reaction time on the yield distribution of BPCAs were studied for the first time. The results indicate that BPCAs with four or five carboxyls are the predominant products, and BPCAs with one or two carboxyls are formed in a relatively short time; moreover, the formation of BPCAs with more carboxyls is relatively more sensitive to the salting out effect. CP/MAS 13C NMR spectra and oxidation of model compounds show that phenolic, ether-substituted aromatic, ether, and aldehyde groups are easily converted and that water-soluble acids (WSA) are formed rapidly and largely due to the breakage of these bonds. The step from WSA to BPCAs is relatively slow mainly due to the inertia of the aromatic clusters with attached carboxyls or carboxylate. On the whole, the BPCAs are derived from aromatic clusters through the oxidation of condensed benzene rings, bridges, or peripheral groups that are attached to the aromatic clusters. Possible mother units for BPCAs in the lignite are suggested based on the generally agreed lignite structure.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3021297

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 14980–14993

Titre :	Free-radical-induced degradation of aqueous polyethylene Oxide by UV/H2O2 : Experimental design, reaction mechanisms, and kinetic modeling
Type de document :	texte imprimé
Auteurs :	Samira Ghafoori, Auteur ; Mehrab Mehrvar, Auteur ; Philip K. Chan, Auteur
Année de publication :	2013
Article en page(s) :	pp. 14980–14993
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Polyethylene Oxide Kinetic
Résumé :	The advanced oxidation of aqueous polyethylene oxide (PEO) is studied using the UV/H2O2 process in a batch recirculation photoreactor. The response surface methodology (RSM), combined with quadratic programming, is used for the experimental design, statistical analysis, and optimization of the process. In the second part, a detailed mathematical model is developed to predict the total organic carbon (TOC) removal as a function of time. Continuous distribution kinetics is applied to establish the kinetic model for the photodegradation of PEO. The model is validated at different influential operating conditions using experimental data obtained by a recirculating batch photoreactor. An excellent agreement between the model predictions and the experimental data is confirmed for all experimental conditions. Also, the intrinsic rate constants are estimated using an optimization algorithm. The model provides a good insight into the free-radical-induced degradation mechanisms and kinetics that could be considered for the process optimization.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3005995

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 14966-14979

Titre :	Application of some condensed uracils as corrosion inhibitors for mild steel : Gravimetric, electrochemical, surface morphological, UV–visible, and theoretical investigations
Type de document :	texte imprimé
Auteurs :	Dileep Kumar Yadav, Auteur ; Mumtaz Ahmad Quraishi, Auteur
Année de publication :	2013
Article en page(s) :	pp. 14966-14979
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Ultraviolet radiation Mild steel Corrosion inhibitor
Résumé :	Gravimetric, electrochemical impedance spectroscopy (EIS), linear polarization resistance (LPR), and potentiodynamic polarization (PDP) studies were carried out to investigate the comparative corrosion protection efficiency of four condensed uracils (CUs) on mild steel in 1 M HCl. EIS plots indicated that the addition of inhibitors increases the charge-transfer resistance (Rct), decreases the double-layer capacitance (Cdl) of the corrosion process, and hence increases inhibition performance. Moreover, the thermodynamic activation parameters for the corrosion reaction were calculated and discussed in relation to the stability of the protective inhibitor layer. The morphology of the surface was examined by scanning electron microscopy (SEM), and the surface composition was evaluated using energy-dispersive X-ray spectroscopy (EDX) to verify the presence of inhibitor on the mild steel surface. Quantum chemical study suggests that the heterocyclic rings in these compounds are structurally essential for the protection of the mild steel surface.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26679616

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 14958-14965

Titre :	Hydrothermal synthesis of Co3O4–graphene for heterogeneous activation of peroxymonosulfate for decomposition of phenol
Type de document :	texte imprimé
Auteurs :	Yunjin Yao, Auteur ; Zeheng Yang, Auteur ; Hongqi Sun, Auteur
Année de publication :	2013
Article en page(s) :	pp. 14958-14965
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Activation
Résumé :	This paper reports the synthesis of Co3O4―reduced graphene oxide (rGO) hybrids and the catalytic performance in heterogeneous activation of peroxymonosulfate (PMS) for the decomposition of phenol. The surface morphologies and structures of the Co3O4―rGO hybrids were investigated by field emission scanning electron microscopy (SEM), energy-dispersive X-ray spectrometer (EDS), transmission electron microscopy (TEM), powder X-ray diffraction (XRD), Raman spectroscopy, Fourier transform infrared spectroscopy (FTIR), and thermogravimetric analysis (TGA). Through an in situ chemical deposition and reduction, Co3O4―rGO hybrids with Co3O4 nanoparticles at an average size of 33 nm were produced. Catalytic testing showed that 20 mg/L of phenol could be completely oxidized in 20 min at 25 °C on Co3O4―rGO hybrids, which is mostly attributed to the generation of sulfate radicals through Co3O4-mediated activation of PMS. Phenol oxidation was fitted by a pseudo-zero-order kinetic model. The rate constant was found to increase with increasing temperature and PMS dosage, but to decrease with increasing initial phenol concentration. The combination of Co3O4 nanoparticles with graphene sheets leads to much higher catalytic activity than pure Co3O4. rGO plays an important role in Co3O4 dispersion and decomposition of phenol.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26679615

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 14949-14957

Titre :	Mechanistic insights into thermal stability improvement of exo-tetrahydrodicyclopentadiene by 1,2,3,4-tetrahydroquinoline
Type de document :	texte imprimé
Auteurs :	Sun Hee Park, Auteur ; Joongyeon Kim, Auteur ; Jeong Hwan Chun, Auteur
Année de publication :	2013
Article en page(s) :	pp. 14949-14957
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Thermal stability
Résumé :	We investigated the thermal stability of exo-tetrahydrodicyclopentadiene (exo-THDCP, C10H16) in the absence and presence of 1,2,3,4-tetrahydroquinoline (THQ), which acts as a hydrogen donor (H-donor). It was found that conversion of exo-THDCP was faster at the higher temperature. The increase in the rate of
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26679614

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 14941–14948

Titre :	Swelling and Dye-Adsorption Characteristics of an Amphoteric Superabsorbent Polymer
Type de document :	texte imprimé
Auteurs :	Neelesh Bharti Shukla, Auteur ; Shruti Rattan, Auteur ; Giridhar Madras, Auteur
Année de publication :	2013
Article en page(s) :	pp. 14941–14948
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Adsorption Polymer
Résumé :	Amphoteric superabsorbent polymers (SAPs) based on the anionic monomer sodium acrylate (SA) and the cationic monomer [2-(methacryloyloxy)ethyl]trimethylammonium chloride (METAC) were synthesized by solution polymerization using N,N′-methylenebisacrylamide as a cross-linking agent. The ratio of anionic to cationic repeat units was varied to obtain anionic, cationic, and amphoteric SAPs. The synthesized SAPs were characterized by Fourier transform infrared spectroscopy. The equilibrium swelling capacity of the SAPs was found to be dependent on the nature and extent of the net charge on the SAPs but independent of pH. The equilibrium swelling capacity was lowest for the SAP whose ratio of anionic to cationic repeat units was unity. The equilibrium swelling capacity increased as this ratio deviated from unity. The adsorption of an anionic dye (orange G) and a cationic dye (methylene blue) was carried out from the individual solution as well as from their mixture. The adsorption of the dyes was found to be dependent on the nature and amount of net charge on the SAPs but independent of pH. The amount of the dye adsorbed decreased as the net charge on the amphoteric SAPs decreased. The amphoteric SAPs with net negative or positive charge selectively adsorbed oppositely charged dyes from the mixture, but the amounts adsorbed were lower than those adsorbed from the individual dye solutions.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301839z

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 46 (Novembre 2012) . - pp. 14935-14940

Titre :	Novel in situ batch reactor with a facile catalyst separation device for biodiesel production
Type de document :	texte imprimé
Auteurs :	Yanjun Jiang, Auteur ; Hanqi Gu, Auteur ; Liya Zhou, Auteur
Année de publication :	2013
Article en page(s) :	pp. 14935-14940
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Production Catalyst Reactor Batchwise In situ
Résumé :	In an effort to reduce the production cost of biodiesel and realize the lipase recovery of the in situ transesterification technology, a reactor with facile catalyst separation device was developed in this study. Compared with conventional method of biodiesel production, this improved reactive extraction technology can realize not only the biodiesel synthesis in a single step, but also the separation of immobilized lipases from the oilseed residues easily. This technology may present a sustainable, economically attractive process for biodiesel production. J. curcas L. seed, methanol, Lipozyme TL IM, and cosolvent n-hexane were used in this study. The effect of various process parameters on the yield of fatty acid methyl esters (FAMEs) was investigated. The highest FAMEs yield of 90.6% could be achieved under the optimum conditions: n-hexane/seed ratio of 3.5:1 mL/g, methanol/oil molar ratio of 6:1, 15% (w/w) of Lipozyme TL IM, reaction temperature of 45 °C, water content of 1.0%, and reaction time of 12 h. The lipase could maintain more than 40% of its initial activity after 13 batches operation under optimal reaction conditions. This simple in situ transesterification technology with facile catalyst separation device can be a potential route for biodiesel production, which may greatly reduce the processing steps and costs.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26679612

Industrial & engineering chemistry research / Paul, Donald R. . Vol. 51 N° 46

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