Catalogue en ligne Bibliothèque Ecole Nationale Polytechnique d'Alger

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp.12793 -12797

Titre :	Evaluation of interaction forces between nanoparticles by molecular dynamics simulation
Type de document :	texte imprimé
Auteurs :	Qinghua Zeng, Auteur ; Aibing Yu, Auteur ; Gaoqing (Max) Lu, Auteur
Année de publication :	2011
Article en page(s) :	pp.12793 -12797
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Shape controlled synthesis Microscope Crystals Surface
Résumé :	Molecular dynamics simulations are used to quantify the interaction forces between nanoparticles, which are critical to nanoparticle systems. It is shown that the fluctuation of surface atomic density and the dynamics of collisions significantly affect the interaction forces. As a result, the Hamaker method cannot accurately estimate the interaction forces for nanoparticles. The proposed approach offers an effective method for determining the interaction forces between nanoparticles. © 2010 American Chemical Society.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://espace.library.uq.edu.au/view/UQ:226534

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12783–12792

Titre :	Numerical Investigation of Nucleating-Agent-Enhanced Heterogeneous Nucleation
Type de document :	texte imprimé
Auteurs :	C. Wang, Auteur ; S. N. Leung, Auteur ; M. Bussmann, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12783–12792
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Heterogeneous nucleation
Résumé :	Nucleating agents have long been employed in polymeric foaming processes to promote cell nucleation, increase cell density, and improve cell uniformity. This improvement in foam morphology is usually considered to result from the enhanced heterogeneous nucleation caused by the lower free energy barrier for cell nucleation. However, less is known about the underlying mechanisms of nucleating-agent-enhanced nucleation. In the polymer foaming process, pressure is a critical parameter that affects the degree of supersaturation of gas within a polymer−gas solution. In most previous theoretical studies on cell nucleation, a uniform pressure was assumed throughout the solution. Although this assumption may be acceptable when no particles have been added, its validity is questionable when nucleating agents are present. It has been speculated that growing cells that have already been nucleated generate local flow fields that induce tensile stresses around nearby particles, resulting in local pressure fluctuations. The discontinuity at the interface between a nucleating agent particle and the surrounding polymer melt yields local pressure and stress fields around the particle that are different from those in the bulk, which may enhance it as a potential heterogeneous nucleation site. This paper presents a numerical analysis to investigate the pressure profile in the vicinity of nucleating agents and provides new information about the underlying mechanism that promotes cell nucleation in the presence of nucleating agents.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie1017207

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12773-12782

Titre :	Molecular characterization of gasoline and diesel streams
Type de document :	texte imprimé
Auteurs :	Yongwen Wu, Auteur ; Nan Zhang, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12773-12782
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Gasoline Diesel Streams
Résumé :	A novel methodology to characterize gasoline and diesel streams into the molecular level is developed on the basis of molecular type homologous series (MTHS) matrix framework (Chem. Eng. Sci. 2005, 60, 6702−6717). The method comprises the enhancements of both representation matrix construction and transformation methodology of bulk properties into molecular composition. To improve the accuracy and adequacy of the representation model, different strategies are set up separately for gasoline and diesel streams for the consideration of isomers. By introducing statistical distribution and applying extensive bulk properties, the transformation approach is revolutionized to increase the usability, and tackle the challenge of possibly achieving significantly different molecular compositions from the same bulk properties of refining streams by existing transformation approaches. The proposed method is verified with both gasoline and diesel streams, and the results show a good agreement with measured data.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie101647d

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12762–12772

Titre :	Biogenic Synthesis of Au Nanoparticles Using Vascular Plants
Type de document :	texte imprimé
Auteurs :	Roza Bali, Auteur ; Andrew T. Harris, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12762–12772
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Nanoparticles Biogenic
Résumé :	The known metallophytes Brassica juncea (B. juncea) and Medicago sativa (M. sativa) were investigated for their ability to accumulate and sequester gold (Au) from aqueous solutions of KAuCl4. Once sequestered, some of the metal was stored as nanoparticles, throughout the epidermis, cortex, and vascular tissue for both species, but predominantly located in the xylem parenchyma cells. Nanoparticle size distribution within the plant tissues was determined. In general, particle sizes ranged between 2 nm to 2 μm in B. juncea and 2 nm to 1 μm in M. sativa and was location dependent; root located nanoparticles had similar size distributions in both species, whereas the distribution within above ground tissues differed between M. sativa and B. juncea, with B. juncea showing a much broader range of particle sizes. Au(0) nanoparticles were also formed ex vivo following contact between root exudates and an aqueous solution of KAuCl4 resulting in the reduction of Au(III) to Au(0). The largest proportion of particles was in the range 5−10 nm (B. juncea) and 10−20 nm (M. sativa). The mechanism of growth of Au(0) nanoparticles using live plants, both in vivo and ex vivo is consistent with Turkevich [Gold Bull. 1985, 18 (3), 86−91], who suggested that the process of Au(0) particle formation involved the interplay of crystal nucleation, growth, and coagulation.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie101600m

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12756–12761

Titre :	Characterization of oil - water emulsion and its use in enhanced oil recovery
Type de document :	texte imprimé
Auteurs :	Ajay Mandal, Auteur ; Abhijit Samanta, Auteur ; Achinta Bera, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12756–12761
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Oil water emulsion
Résumé :	Oil-in-water emulsions are important in the petroleum industry as a displacing fluid for enhanced oil recovery (EOR). To investigate the efficiency of oil−water emulsions in EOR, experiments were performed to characterize the emulsions in terms of their physicochemical properties and size distribution of the dispersed oil droplet in water phase. In the present study commercially available gear oil was used to prepare oil-in-water emulsions. Flooding experiments were also carried out to evaluate the effectiveness of the emulsion as displacing fluid for enhanced oil recovery. Substantial additional recoveries (more than 20% of original oil in place) over conventional water flooding were obtained in the present investigation.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie101589x

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12747-12755

Titre :	Beclomethasone microparticles for wet inhalation, produced by supercritical assisted atomization
Type de document :	texte imprimé
Auteurs :	Ernesto Reverchon, Auteur ; Renata Adami, Auteur ; Mariarosa Scognamiglio, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12747-12755
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Supercritical state Microparticle
Résumé :	Supercritical assisted atomization (SAA) was used to produce micronized particles of beclomethasone dipropionate (BDP) to be used for inhalation therapy. Methanol, acetone, acetone + water 9% v/v, and methanol + water 4% v/v were tested as liquid solvents to explore their influence on particle size and crystalline structure of the precipitated powder. Particles with narrow size distributions (PSD) were obtained by changing the SAA process operating conditions. In particular, using acetone + water 9% v/v with a BDP concentration of 90 mg/mL, crystalline particles ranging between 0.2 and 4.7 μm were produced and 70% by volume of these particles ranged between 1 and 3 μm. PSD stability analysis in a wet formulation showed that BDP powder obtained by SAA does not modify over a long period of time. The results obtained on the laboratory scale plant were successfully reproduced on a pilot plant and a further refinement of the operating conditions was performed. About 30 g of BDP microparticles were produced per batch and a recovery of about 93 wt % of the micronized powder with respect to the injected quantity was obtained. The largest volumetric fraction of BDP particles falling in the range 1-3 μm was 83% on the pilot scale.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23692032

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12740–12746

Titre :	Influence of the Solvent Quality on the Thermodynamic Behavior of Polymethylphenylsiloxane Solutions
Type de document :	texte imprimé
Auteurs :	Cristina-Eliza Brunchi, Auteur ; Simona Morariu, Auteur ; Maria Cazacu, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12740–12746
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Solvent quality Thermodynamic
Résumé :	In this work we investigate the effect of the solvent quality on the thermodynamic behavior of the polydimethyldiphenylsiloxane copolymer by using turbidimetry and viscosimetry. The turbidimetric method was used for the determination of the composition of the solvent mixture at the theta point. The experimental data obtained by using the capillary viscometry both in good and theta solvent conditions have been processed by using classical Huggins equation and new Wolf model (2007), which allows the calculation of intrinsic viscosities and other hydrodynamic parameters. The results obtained by using the two approaches were discussed comparatively. The conformational properties of copolymer in solution depend on their molecular structure, which is essentially dominated by the solvent quality, reflecting the balance of the interactions between the polymer chains and each solvent and that between solvent molecules.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie1015238

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12726–12739

Titre :	Thermodynamic analysis of systems formed by alkyl esters with a - w alkyl dibromides : new experimental information and the use of a dense database to describe their behavior using the UNIFAC group contribution method and the COSMO - RS methodology
Type de document :	texte imprimé
Auteurs :	Ana Navas, Auteur ; Juan Ortega, Auteur ; Tomas Martin, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12726–12739
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Thermodynamic
Résumé :	This is a theoretical study carried out on the experimental data obtained for 90 binary systems comprised of alkyl esters with dibromoalkanes, using data from previous publications and those corresponding to 20 mixtures presented here. The experimental part of this work corresponds to experimental measurements of HmE and VmE at T = 298.15 K and atmospheric pressure for systems containing propyl alkanoates (methanoate to butanoate) with 1,ω-dibromoalkanes (ω = 2−6). The systems containing propyl methanoate present HmE > 0, while the remaining ones give values of HmE that follow a sigmoid distribution. The VmE of these mixtures of propyl esters are either positive or negative, depending on the dihalide involved. Positive ones correspond to mixtures with short-chain dibromoalkanes, and contraction effects are observed with the increasing chain length of the dihalide compound. On the whole, experimental information suggests a specific behavior with either positive or negative structural mixing effects depending on the chain length of the compounds. HmE values were estimated theoretically by applying two different types of models. The UNIFAC group contribution model gives good results in the prediction, but only when the Br, Br/carboxylate interaction is considered to vary with the chains of the ester and dibromoalkane; mathematical expressions are presented to describe these variations for the entire set of mixtures. The COSMO-RS quantum-chemical method is also applied to predict HmE values for the systems studied and the results extrapolated to a set of 90 systems (alkyl alkanoates + dibromoalkane), optimizing the model parameters, especially to obtain an adequate description of the Van der Waals interactions. As a result, the optimized COSMO-RS method can be used to interpret the behavior of the HmE for the whole group of alkyl esters + dibromoalkane in terms of the different intermolecular interactions taking place inside the pure compounds and mixtures, especially in relation to the variable effects of the alkyl chains of the components on the mixing enthalpies.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie101479v

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12718–12725

Titre :	Phase equilibria of mixtures containing organic sulfur species (OSS) and water / hydrocarbons : VLE measurements and modeling using the cubic - plus - association equation of state
Type de document :	texte imprimé
Auteurs :	Javeed A. Awan, Auteur ; Ioannis Tsivintzelis, Auteur ; Martin P. Breil, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12718–12725
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Organic sulfur Hydrocarbons
Résumé :	We report new vapor−liquid equilibrium (VLE) data for dimethyl sulfide (DMS) in pure water, performed at three temperatures (303, 330, and 362 K) in the 1−8 MPa pressure range. The total system pressure was maintained introducing CH4. The inlet mole fraction of DMS was the same in all experiments, around 1.5 × 10−3 in the liquid phase. A “static-analytic” method was used for performing all of the measurements. The objective is to provide experimental VLE data for the dimethyl sulfide + CH4 + water system, for which no data are available in the open literature. These data will allow industry to model sulfur emissions. The new VLE data as well as the VLE data of some binary systems from the literature containing organic sulfur species + hydrocarbon, organic sulfur species + water, and some ternary systems containing organic sulfur species in hydrocarbons and water have been modeled successfully with the cubic-plus-association (CPA) equation of state. Useful remarks are presented about the application of Henry’s constant values to estimate binary interaction parameters of the CPA EoS for the description of whole vapor−liquid equilibria. The results using CPA EoS show that the cross association interactions in the methyl mercaptan + water system and ethyl mercaptan + water system should be considered. In aqueous mixtures of higher mercaptans, the consideration of such interactions does not improve the calculations, indicating that they are rather weak.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie101470b

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12709–12717

Titre :	Effects of O2 on characteristics of sulfur added to petroleum coke through reaction with SO2
Type de document :	texte imprimé
Auteurs :	Eric A. Morris, Auteur ; Charles Q. Jia, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12709–12717
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Sulfur petroleum coke
Résumé :	Alberta oil-sands petroleum coke is an abundant byproduct of the upgrading of bitumen. The current study aims to improve the current understanding of sulfur added to the surface of petroleum coke through reaction with sulfur dioxide (SO2) and how this is affected by a large excess of oxygen (O2). Particular focus is given to the distribution and speciation of sulfur within the coke particles, as well as its thermal stability. Petroleum coke was activated in SO2 with and without O2 in a packed bed reactor at 600−800 °C. The activated cokes were characterized with electron probe microanalysis (EPMA), X-ray photoelectron spectroscopy (XPS), thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). Cross-sectional analysis with EPMA of activated coke particles revealed that sulfur-rich coke particles (i.e., SIAC) could be produced with and without O2. Under low SO2 (3%), high O2 (18%) conditions, however, O2 competitively reacted with coke at 600 °C, and SO2 only reacted to form a sulfur-rich layer after O2 had been depleted. Analysis with XPS suggested that the sulfur-rich layer of the coke particles was made up of thiophene from the coke plus carbon−sulfur surface complexes, mainly heterocyclic sulfide and disulfide, while the presence of aliphatic sulfide, thiolactone, and thiol could not be ruled out. TGA and DSC analyses confirmed that sulfur added to activated coke via reaction with SO2 was not elemental in nature. In both N2 and air, sulfur added via high-temperature reaction with SO2 is more thermally stable than that of a commercial SIAC sulfurized at lower temperatures. This may have beneficial implications if these SO2 activated cokes were to be used to capture mercury, since they could be thermally regenerated with minimal loss of active sulfur surface sites while the captured mercury is collected, avoiding the costly and potentially problematic landfill disposal of Hg-containing activated carbon.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie101388q

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12702–12708

Titre :	Prediction of flash point of organosilicon compounds using quantitative structure property relationship approach
Type de document :	texte imprimé
Auteurs :	Chan-Cheng Chen, Auteur ; Horng-Jang Liaw, Auteur ; Yi-Jen Tsai, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12702–12708
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Organosilicon compounds
Résumé :	Flash point (FP) is the primary property to classify flammable liquids for the purpose of assessing their fire and explosion hazards. Because of the advancement of technology in discovering or synthesizing new compounds, there is often a significant gap between the demand for such data and their availability. In this regard, reliable methods to estimate the FP of a compound are indispensible. In this work, a quantitative structure property relationship study is presented for predicting the FP of organosilicon compounds. To build up and validate the proposed models, a data set of 230 organosilicon compounds are collected and divided into a training set of 184 compounds and a testing set of 46 compounds. The stepwise regression method is used to select the required molecular descriptors for predicting the FP of organosilicon compounds from 1538 molecular descriptors. Depending on the p-value for accepting a descriptor to enter the model, models with different number of descriptors are obtained. A 13-descriptor model and a 6-descriptor model are obtained with the p-value of 5 × 10−4 and 1 × 10−5, respectively. It is found that the 6-descriptor model could fit the training data with R2 = 0.8981 and predict the test data with Q2 = 0.8533 and the 13-descriptor model could fit the training data with R2 = 0.9293 and predict the test data with Q2 = 0.9245. The average predictive errors are less than 5% for both proposed models and they are useful for many practical applications, because the proposed models used only calculated descriptors from the molecular structure.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie101381b

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12696-12701

Titre :	Critical - point temperature of ionic liquids from surface tension at liquid — vapor equilibrium and the correlation with the interaction energy
Type de document :	texte imprimé
Auteurs :	Mohammad Hadi Ghatee, Auteur ; Fatemeh Moosavi, Auteur ; Amin Reza Zolghadr, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12696-12701
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Correlation analysis Correlation Phase equilibrium Liquid vapor equilibrium Surface tension Ionic liquid Critical point
Résumé :	The critical temperature of ionic liquids is predicted by scaling-law, Guggenheim, and Eötvös approaches using surface tension data measured in the temperature range of 293-393 K. The available surface tensior data for imidazolium-, phosphonium-, and ammonium-based ionic liquids, with different anions content, show that the predicted critical temperature is a function of cation type and its alkyl chain length as well as the anion type. According to this dependence on the nature of the ionic liquid, the anion-cation interactior energy (Einter) was calculated by quantum mechanical density functional theory and the correlation with the predicted critical temperature was studied. The predicted critical temperature has a direct correlation to the absolute value of Einter. The ionic liquids with the BF4- anion, which consistently have the highest critica point temperature, also have the largest absolute value of Einter. As the alkyl chain length increases, the critica temperature decreases. When the surface tension is measured under a liquid-vapor equilibrium, the prediction has the meaningful feature of producing the critical-point temperature.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23692026

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12685-12695

Titre :	A new Neural network group contribution method for estimation of upper flash point of pure chemicals
Type de document :	texte imprimé
Auteurs :	Farhad Gharagheizi, Auteur ; Reza Abbasi, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12685-12695
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Group contribution method Neural network
Résumé :	In this study, a new group contribution-based model is presented for the prediction of the upper flash point temperature of pure compounds based on a large data set containing 1294 pure compounds. The model is a neural network using a number of occurrences of 122 chemical groups in a pure compound to predict its related UFLT (Upper Flash Point Limit). The squared correlation coefficient, average percent error, mean average error, and root-mean-square error of the model over the main data set containing 1294 pure compounds are 0.99, 1.7%, 6, and 8.5, respectively.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23692025

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12675-12684

Titre :	Synthesis and characterization of novel poly (N - isopropylacrylamide - co - N,N' - dimethylaminoethyl methacrylate sulfate) hydrogels
Type de document :	texte imprimé
Auteurs :	Gulten Gurdag, Auteur ; Bestenur Kurtulus, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12675-12684
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Hydrogels
Résumé :	Poly(N-isopropylacrylamide-co-N,N'-dimethylaminoethyl methacrylate sulfate) [P(NIPAM-co-DMAEMASA)] was prepared from N-isopropylacrylamide (NIPAM) and N,N-dimethylaminoethyl methacrylate sulfate (DMAEMASA) monomers, and its properties were compared with those of poly(N-isopropylacrylamide-co-N,N'-dimethylaminoethyl methacrylate) [P(NIPAM-co-DMAEMA)]. The copolymers were characterized by swelling measurements in distilled water (10-40 °C) and buffer solutions (I = 0.1 M, pH = 2.2-10.0), FTIR, DSC, and SEM methods. The ESV's of the NIPAM-DMAEMASA copolymers in distilled water were 5 times higher than those of P(NIPAM-co-DMAEMA); they decreased with an increase in comonomer (DMAEMASA/DMAEMA) content for both copolymers. While NIPAM-DMAEMASA copolymers did not display any phase transition with temperature, the LCST of the NIPAM-DMAEMA copolymer was determined as 20 °C. Both copolymers displayed a phase transition at pH = 5.0, but the pH of the phase transition for NIPAM-DMAEMA gels shifted to 7.0 with increased DMAEMA content. Glass transition temperatures of NIPAM copolymers did not change with the type and content of comonomer.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23692024

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12663-12674

Titre :	Modeling of carbon dioxide absorption by aqueous ammonia solutions using the extended UNIQUAC model
Type de document :	texte imprimé
Auteurs :	Victor Darde, Auteur ; Willy J. M. Van Well, Auteur ; Erling H. Stenby, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12663-12674
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Gas absorption Carbon dioxide Modeling
Résumé :	An upgraded version of the extended UNIQUAC thermodynamic model for the carbon dioxide-ammonia-water system has been developed, on the basis of the original version proposed by Thomsen and Rasmussen (Chem. Eng. Sci. 1999, 54, 1787). The original model was valid in the temperature range 0-110 °C, the pressure range 0-10 MPa, and the concentration range up to 80 m ammonia. In this work, the validity of this model was extended up to 150 °C and the accuracy improved by increasing the number of experimental data points from 2000 to more than 3700. These experimental data consisting of vapor-liquid equilibrium data in various concentration ranges, enthalpy change from partial evaporation measurements, speciation data, heat capacity, enthalpy of solution, and enthalpy of dilution data have been used to refit 43 model parameters and standard-state properties. Henry's law constant correlations have been used for extrapolating standard-state properties of carbon dioxide and ammonia to supercritical conditions.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23692023

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12654–12662

Titre :	Process control and investigation of oxidation kinetics of postoxidative effluents using gas chromatography with pulsed flame photometric detection (GC - PFPD)
Type de document :	texte imprimé
Auteurs :	Grzegorz Boczkaj, Auteur ; Marian Kaminski, Auteur ; Andrzej Przyjazny, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12654–12662
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Kinetics
Résumé :	This article presents the results of investigations on the use of headspace analysis and gas chromatography with pulsed flame photometric detection (HSA-GC-PFPD) to evaluate the effectiveness of oxidation of postoxidative effluents from the production of bitumens. Samples of effluents from the bitumen oxidation unit were used in the experiments. In addition, the kinetics of effluent oxidation was also investigated. The content of volatile sulfur compounds (VSCs) was determined using HSA-GC-PFPD. The results were correlated with chemical oxygen demand (COD). The changes in concentration of individual volatile sulfur compounds in the course of effluent oxidation were measured, which enabled the determination of the order of the oxidation reactions. The usefulness of the determination of VSCs in the headspace as a reliable technique for evaluating the reduction in emissions of volatile malodorous compounds was demonstrated. The developed method is also useful for process control of the oxidation of postoxidative effluents. The procedure ensures an objective evaluation of the effectiveness of the removal of volatile sulfur compounds from postoxidative effluents. The experimental results revealed that the effectiveness of the oxidation of organosulfur compounds was much higher than that of other classes of organic compounds. Furthermore, the order of oxidation reactions along with the rate constants of thiophenol, p-thiocresol, and hydrogen sulfide were determined. An advantage of the developed procedure is that it can be automated.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100939x

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12646-12653

Titre :	A heuristic - embedded scheduling system for a pharmaceutical intermediates manufacturing plant
Type de document :	texte imprimé
Auteurs :	Jiyong Kim, Auteur ; Junghwan Kim, Auteur ; Taeyeong Lee, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12646-12653
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Manufacturing Scheduling
Résumé :	This paper proposes a new mathematical model for a real pharmaceutical intermediates manufacturing (PIM plant. To consider the general characteristics of the scheduling problems experienced at PIM plants, the propose model employed a strategy to address a mixed-integer linear programming (MILP) formulation. Two heuristi techniques—preclassification of equipment and sequential two-stage optimization-were then proposed, to relax the complexities of scheduling problems that are due to practical constraints. The objective function the proposed model is to minimize the total operation time (makespan) that is subject to the mass balance constraints and process boundary conditions. On the basis of the proposed models and heuristics, new package software is developed for an application to real PIM plants. To show the features and capabilities of th proposed scheduling system, four real examples were examined. The results reveal that the techniques ar helpful for obtaining both higher accuracy of optimized solutions and higher computational performance.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23692021

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp.12638–12645

Titre :	Pre - extraction of hemicelluloses from hardwood chips using an alkaline wood pulping solution followed by kraft pulping of the extracted wood chips
Type de document :	texte imprimé
Auteurs :	Sara L. Walton, Auteur ; Dwane Hutto, Auteur ; Joseph M. Genco, Auteur
Année de publication :	2011
Article en page(s) :	pp.12638–12645
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Hemicelluloses Wood
Résumé :	Mixed southern hardwood chips were extracted with an alkaline wood pulping solution called kraft green liquor. This aqueous solution containing mainly sodium carbonate and sodium sulfide was applied at different alkali charges (expressed as Na2O) of 0, 2, 4, and 6% on dry wood weight. The extractions were performed at 160 °C for effective times ranging from about 1−2 h to determine the effect of extraction severity on pulp yield and composition of the extracted liquor. The severity of hemicellulose extraction time and alkaline charge controls the concentration of acetic acid and monosaccharide sugars available for downstream processing, the accumulation of degradation products such as organic acids and furans in the extract, and the pulp yield attainable for the extracted wood chips. As the alkali charge was increased, the amount of acetate side chains on the hemicelluloses and the dissolved lignin in the extract increased but the carbohydrate and sugars in the extract decreased appreciably. Water extraction (0% alkali addition) released the greatest amount of carbohydrates, up to 30 g/L measured as component sugars, but resulted in the greatest decrease in pulp yield, dropping from 47% to 35%. Extraction with 2% green liquor increased the pulp yield to 51% while greatly reducing the component sugars to 8 g/L. Data obtained in this work will allow selection of optimum hemicellulose extraction conditions for integrating the extraction operation into the Kraft pulping process.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100848p

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12632-12637

Titre :	Preparation of spherical ammonium nitrate particles by melt spray
Type de document :	texte imprimé
Auteurs :	Jae-Kyeong Kim, Auteur ; Seung-Il Choi, Auteur ; Eui Jung Kim, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12632-12637
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Preparation Spherical ammonium
Résumé :	Spherical ammonium nitrate particles with average diameters of 82-206 μm were produced using the mel spray system built in the present work. The effects of spray pressure and temperature on the size distribution and average diameter of the ammonium nitrate particles were investigated. It was found that increasing the spray pressure at given temperature or increasing the temperature at given pressure enhanced the disintegration of the front edge of the liquid sheet into fine droplets and, thus, slightly reduced the average diameter of the ammonium nitrate particles. X-ray diffraction patterns confirmed all spherical ammonium nitrate particles to be form IV because of a rapid phase transition from form I to form IV. Dombrowski and Johns' equation which is applicable to highly viscous spray fluids, was found to be satisfactory for estimating the Saute diameter of the ammonium nitrate particles.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23692019

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12620-12631

Titre :	Enhancement of particle collection efficiency in electrohydrodynamic atomization process for pharmaceutical particle fabrication
Type de document :	texte imprimé
Auteurs :	Alireza Rezvanpour, Auteur ; Amalina B. E. Attia, Auteur ; Chi-Hwa Wang, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12620-12631
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Electrohydrodynamics Particle collection
Résumé :	In the present work, Electrohydrodynamic Atomization was employed to produce biodegradable polymeri microparticles in a new generation of shuttle glass chamber. The effects of different parameters including solution flow rate, nitrogen flow rate, nozzle, and ring voltage on the particle collection efficiency and residua amount of organic solvent in collected particles were investigated systematically. The Taguchi (a combine< experimental and statistical) method was used to obtain the optimal collection conditions for the particle collection efficiency. It was found that the important factors affecting particle collection efficiency were given in the following order-solution flow rate, nitrogen flow rate, ring, and nozzle voltage. It was also found tha voltage difference between nozzle and ring can significantly affect the particle collection efficiency. Duration of the process, polymer material, and electrical conductivity of the solution were the other factors that affected particle collection efficiency. It was found that solution flow rate and nozzle voltage can considerably affec the size of fabricated particles. Gas Chromatography/Mass Spectrometry was used to determine the residua content of Dichloromethane (DCM) in the collected particles. For all 16 trials, the residual DCM content o the particles fabricated using the EHDA method was well within the limit of safety standards (600 ppm) a the end of process without engaging any additional freeze-drying process. In summary, high collection efficiency and minimum residual solvent in collected particles can be achieved by adjusting the operating parameters and geometrical characteristics of the system.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23692018

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12613–12619

Titre :	Liquid - liquid equilibrium for ternary systems containing ethyl esters, anhydrous ethanol and water at 298.15, 313.15, and 333.15 K
Type de document :	texte imprimé
Auteurs :	Luis A. Follegatti-Romero, Auteur ; Marcelo Lanza, Auteur ; Fabio R. M. Batista, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12613–12619
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Ternary system Phase equilibrium Liquid liquid equilibrium
Résumé :	The most common method used for purifying biodiesel is washing with water. During the biodiesel washing process, two phases are formed, a water-rich phase and an ester-rich one. For this reason, knowledge of the corresponding phase equilibrium is an important step in optimizing the final purification of biodiesel. The objective of this work was to investigate the liquid−liquid equilibrium related to some esters of interest in the production of ethylic biodiesel, in particular the equilibrium data for systems containing ethyl laurate/ethyl myristate + ethanol + water at 298.15, 313.15, and 333.15 K. The data obtained were correlated with the cubic-plus-association equation of state (CPA EoS). It was shown that this model was able to provide a very good description of the phase diagrams of the systems studied.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23692017

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12605-12612

Titre :	Mixed - matrix membrane hollow fibers of Cu3(BTC)2 MOF and polyimide for gas separation and adsorption
Type de document :	texte imprimé
Auteurs :	Jun Hu, Auteur ; Hongpei Cai, Auteur ; Huiqing Ren, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12605-12612
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Adsorption Hollow fiber
Résumé :	Metal-organic framework (MOF) crystals of Cu3(BTC)2 with a high surface area (1396 m2·g-1) were synthesized and mixed with polyimide (PI) to prepare mixed-matrix membranes (MMMs) for gas separations. The PI-Cu3(BTC)2 blend was successfully spun into MMM hollow fiber by the dry/wet-spinning method. SEM images of the fiber cross sections revealed significant plastic deformation of the polymer matrix owing to the strong affinity between Cu3(BTC)2 and PI. The H2 permeance and the selectivity of H2 with respect to other gases such as N2, CO2, O2, and CH4 both increased markedly with increased Cu3(BTC)2 loading. At a loading of 6 wt % Cu3(BTC)2, the permeance of H2 increased by 45%, and the ideal selectivity increased by a factor of 2—3 compared to the corresponding values for pure PI.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23692016

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12596-12604

Titre :	Prediction of the phase behavior of Ionic liquid solutions
Type de document :	texte imprimé
Auteurs :	Li Yang, Auteur ; Stanley I. Sandler, Auteur ; Changjun Peng, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12596-12604
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Ionic liquid Prediction
Résumé :	Here we examine the application of the COSMO-SAC model to phase equilibrium calculations of solutions containing ionic liquids (ILs). As there is uncertainty about the degree of ionization in these liquids, we consider three methods: treating the IL as a neutral molecule, as a separated anion and cation, and essentially as an ion pair. In the first case, the needed quantum mechanics calculation is done for the neutral molecule referred to as COSMO-SAC(molecule), and in the other two cases, the calculations are performed for the separated ions in which the IL is treated as two separate components, COSMO-SAC(ions) or COSMO-SAC(CA), in which the separate cosmo files are combined and the IL is treated as a single-component neutral ion pair. There is generally good agreement between the predicted results and the experimental data using COSMO-SAC(CA) and COSMO-SAC(ions), while for COSMO-SAC(molecule) the results are less satisfactory and the calculations are more difficult because of the problems with geometry optimization and the density functional calculations for the large intact IL molecules. The results show that the COSMO-SAC model can give reasonably good predictions for the vapor—liquid equilibria, liquid—liquid equilibria, and infinite dilution activity coefficients for solutions containing ionic liquids.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23692015

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12587–12595

Titre :	Effect of the acid treatment of olive stone on the biosorption of lead in a packed - bed column
Type de document :	texte imprimé
Auteurs :	Monica Calero de Hoces, Auteur ; Gabriel Blazquez Garcia, Auteur ; Alicia Ronda Galvez, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12587–12595
Note générale :	Chimie industrielle
Mots-clés :	Biosorption
Résumé :	Biosorption of lead(II) ions from aqueous solutions by untreated, HCl-treated, H2SO4-treated, HNO3-treated, and H3PO4-treated olive stone was studied in a continuous-upflow packed-bed column. The effect of acid treatment on the lead biosorption capacity of olive stone was determined by evaluating the breakthrough curves obtained at different inlet concentrations of lead, changing from 10 to 150 mg/L. Results indicated that the treatment of olive stone with inorganic acids improves significantly its capacity to removal lead ions from aqueous solution. Finally, the Adams−Bohart, Thomas, Yoon and Nelson, and dose−response models were used to analyze the experimental data to determine the characteristic parameters of the column useful for process design. In particular, the dose−response model was able to simulate breakthrough curves at lower and higher time periods with high correlation coefficients. The maximum column biosorption capacity predicted by this model at an inlet lead concentration of 150 mg/L was 1.31 mg/g for unmodified olive stone and 14.03 mg/g for olive stone treated by H2SO4. Also, the pH variations during the sorption process have been reported.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie1013597

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12576–12586

Titre :	Simultaneous capture of mercury and CO2 in amine - based CO2 absorption process
Type de document :	texte imprimé
Auteurs :	Zheng Cui, Auteur ; Adisorn Aroonwilas, Auteur ; Amornvadee Veawab, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12576–12586
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Absorption Process
Résumé :	The feasibility of using an amine-based carbon dioxide (CO2) capture unit for the simultaneous capture of mercury (Hg) and CO2 was studied by carrying out Hg absorption experiments with three different types of absorption solutions: mixtures of sodium chloride (NaCl) and sodium hypochlorite (NaOCl), monoethanolamine (MEA), and blended MEA and NaCl/NaOCl. The results show that it is not effective to use the amine-based CO2 unit for the concurrent capture of Hg and CO2 because the Hg absorption performance of aqueous solutions of MEA and blended MEA/NaCl/NaOCl is low. Mixtures of NaOCl and NaCl do not perform as a rate enhancer for Hg removal in the presence of MEA. The presence of Hg in the MEA solutions does not affect the CO2 absorption performance of MEA. To capture both Hg and CO2, a two-step capture process that employs an aqueous NaCl/NaOCl solution for Hg removal, prior to CO2 capture in the amine unit, might be an option.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100687a

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12567–12575

Titre :	Adsorption of neodymium(III) from aqueous solutions using a phosphorus functionalized adsorbent
Type de document :	texte imprimé
Auteurs :	Hyung-Jun Park, Auteur ; Lawrence L. Tavlarides, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12567–12575
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Adsorption neodymium Aqueous solutions
Résumé :	Separation of neodymium(III) from aqueous solutions is investigated using an phosphorus based sol−gel adsorbent. This adsorbent has been formed by the sol−gel synthesis method. The speciation diagram of Nd(III) in an aqueous phase with varying pH is studied by analyses of the equilibria equations. Batch adsorption equilibrium studies show an increase in neodymium uptake capacity with increase in pH in the range from pH 0.5 to pH 6.5, and the maximum uptake capacity at pH 6 is observed to be 1.13 mmol/g (160 mg/g). The equilibrium adsorption isotherm gives a satisfactory fit of the adsorption data. A kinetics study conducted with different concentrations and particle sizes of neodymium(III) in a batch reactor shows a high rate of adsorption. The adsorbent shows a capability of selectivity toward Nd(III) and other rare earths. Adsorption tests in a fixed bed column show a sharp breakthrough curve. Stripping of the neodymium-loaded column bed is achieved using 1 M HNO3. The material also has sustainable stability over repeated metal loading and stripping in a column. In addition to the experimental studies, the adsorption processes in batch and packed column systems are successfully modeled by using a pore diffusion model, and the results are presented. The organophosphorus functionalized adsorbent is demonstrated to be an effective sorbent material for the separation of neodymium(III) from aqueous solutions.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100403b

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12560–12566

Titre :	Fabrication of bimodal porous CaTiO3 microspheres using composite agarose/CaCO3 beads as template
Type de document :	texte imprimé
Auteurs :	Kai-Feng Du, Auteur ; Xiao-Yan Dong, Auteur ; Yan Sun, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12560–12566
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Microspheres Bimodal porous
Résumé :	Agarose gel entrapping CaCO3 granules is used for the synthesis of bimodal porous CaTiO3 beads by a method that combines a sol−gel process and solid phase reaction, in which CaCO3 (1.05 μm) performed as both calcium resource and porogen for creating macropores. The amount of CaCO3 granules embedded in agarose gel is varied from 0 to 16 wt %, and the macropores on the surface and in the inner of final CaTiO3 beads are investigated. It is found that the addition of 12 wt % of CaCO3 produced CaTiO3 beads that present interconnected macropores of about 745 ± 20 nm. The calcination temperature affects the surface area, mesopore size, phase state, and crystalline size of the CaTiO3 beads. By calcination at 450 °C, the CaTiO3 beads prepared by the addition of 12 wt % CaCO3 are amorphous with an average pore size of 9 nm and possess a high surface area of about 225 m2 g−1. With an increase of temperature to 600, 750, and 900 °C, the CaTiO3 is transformed into perovskite in size of about 32, 34, and 37 nm with mesopores of about 20, 23, and 24 nm, respectively, and its specific surface area decreases below 20 m2 g−1. The bimodal porous CaTiO3 beads of about 15 μm are packed into a column for investigating its chromatographic performance. The column shows much higher column efficiency than that packed with CaTiO3 beads without removal of the porogen. The remarkably high separation performance is attributed to the unique surface property and interconnected macropores present in the CaTiO3 beads.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901727s

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12548–12559

Titre :	Turndown control structures for distillation columns
Type de document :	texte imprimé
Auteurs :	Patrick J. Robinson, Auteur ; William L. Luyben, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12548–12559
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Distillation columns
Résumé :	Future chemical plants may be required to have much higher flexibility and agility than existing process facilities in order to be able to handle new hybrid combinations of power and chemical units. An important example is a gasification process producing synthesis gas that can either feed a combustion turbine for the generation of electricity or, during periods of lower power demand, feed a chemical plant. The chemical plant would be designed for the maximum capacity that is associated with periods of minimum electric power demand. But the plant would have to be able to turndown to low throughputs during periods of maximum electric power demand. The 24 h power demand swings in many locations can be a factor of 2 or more from day to night. The separations required in many chemical processes are achieved using distillation columns. If the process must operate over a wide range of throughputs, the columns must also have wide rangeability. There are several low-throughput limitations in distillation columns, usually involving hydraulic constraints. The most common is a low limit on vapor flow rate, below which weeping can adversely affect tray efficiency and separation. The vapor limit depends on tray design, with valve trays being the most rangeable. Even valve trays lose performance below about 50% of design vapor rates. If the plant throughput must be reduced to 25% of design capacity and the column vapor can only be reduced to 50% of design, a control structure that effectively handles this situation is required. The purpose of this paper is to explore three alternative control structures for columns with significant turndown requirements.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie101945x

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12538-12547

Titre :	Plantwide control system design and performance evaluation for ammonia synthesis process
Type de document :	texte imprimé
Auteurs :	Chi Zhang, Auteur ; Suraj Vasudevan, Auteur ; G.P. Rangaiah, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12538-12547
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	System design Control system Process control
Résumé :	The emphasis on process economics in modem chemical plants has led to the increased use of material recycle and energy integration that significantly alter process dynamics and add complexity. As a result, many plantwide control (PWC) methodologies have emerged. However, there are very few comparative studies to evaluate the effectiveness of alternate methodologies. In this study, a PWC structure for the ammonia synthesis process is developed using the integrated framework of simulation and heuristics [Konda et al. Ind. Eng. Chem. Res. 2005, 44, 8300-8313], which is then compared with that developed by Araújo and Skogestad [Araújo and Skogestad, Comput. Chem. Eng. 2008, 32, 2920-2932] using the self-optimizing control procedure. The different control structures are evaluated in a comprehensive manner including assessment of the dynamic performance and steady-state profit.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23692009

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12529-12537

Titre :	Novel syngas production techniques for GTL - FT synthesis of gasoline using reverse flow catalytic membrane reactors
Type de document :	texte imprimé
Auteurs :	C. Dillerop, Auteur ; H. Van den Berg, Auteur ; A. G. J. Van der Ham, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12529-12537
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Catalytic reactor Production Synthesis gas
Résumé :	Syngas production plays a key role in gas-to-liquid (GTL) technology. In this feasibility study, existing and new syngas production techniques are compared. As the conventional autothermal reforming reactors (ATR) always consist of extensive heat exchange equipment and air separation units, alternatives are based on integrating these within the reactor design. Reverse flow catalytic membrane reactors (RFCMR) make it possible to perform heat integration within the reactor; integrated air separation is accomplished by incorporating O2 selective membranes. The alternatives show a higher economic potential than the conventional technique. The use of an O2 selective membrane still experiences reliability problems and was therefore not considered. The second part of the study consists of an extended conceptual design of both the conventional design as well as the reactor with integrated heat transfer. The design involved a GTL plant producing 100 000 bbl/day of gasoline. The feasibility of the reversed flow catalytic membrane reactor is shown by reduced methane and oxygen consumption.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23692008

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12521–12528

Titre :	Decentralized control system design for MIMO processes with integrators / differentiators
Type de document :	texte imprimé
Auteurs :	Wuhua Hu, Auteur ; Wen-Jian Cai, Auteur ; Gaoxi Xiao, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12521–12528
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	MIMO processes integrators
Résumé :	This work extends the concept of relative normalized gain array (RNGA) and proposes a systematic approach to designing decentralized proportional−integral−derivative (PID) control for multi-input−multi-output (MIMO) processes containing integrators and/or differentiators. By determining the input−output-pairing using the relative gain array (RGA)−Nederlinski index (NI)−RNGA criterion, equivalent transfer functions (ETFs) for the selected input−output pairs are derived by utilizing the RGA and RNGA information, which has incorporated the information on loop interactions. Based on the ETFs, decentralized PID controllers are tuned to stabilize the MIMO system independently. The proposed approach is simple, easy to understand, and easy to implement by field engineers. Three industrial MIMO processes with different dimensions and interaction modes are employed to demonstrate the efficiency of the proposed approach.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie1005838

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12513-12520

Titre :	Thickeners in vat dye textile printing : rheology and morphology
Type de document :	texte imprimé
Auteurs :	Ziad Saffour, Auteur ; Chuang C. Wang, Auteur ; Pierre Viallier, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12513-12520
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Morphology Textile industry Vat dye
Résumé :	This paper is a study of the thickeners used in two-phase vat dye textile printing. Throughout this complex process, the thickener dispersion undergoes several transformations, especially spreading on the textile material, drying, and coagulation. Empirical knowledge prescribes several requirements in terms of viscosity but also concerning the dried thickener. But, a better understanding of the phenomena is necessary to determine the origin of possible failure if the basic recipe is modified. Three different thickeners are considered: guaranate, alginate, and modified starch, as well as a combination of these three polymers. Their rheological properties are characterized in both permanent and oscillatory shear flow. Use of a mixture of polymers instead of a simple one avoids undesirable effects of thixotropy, yield stress, and elasticity, for a given value of the viscosity. The process involves the gelation of the thickener by cross-linking of guaranate chains with borate ions. The mechanical properties of such gels strongly depend on the pH, and their stability is affected by the presence of salt. Additionally, thickener films are dried under different conditions, and the morphology of the film is observed at different scales. It is shown that rapid drying at high temperature prevents crystalline structures obtained in the case of slow drying under ambient conditions. This is propitious to a good flexibility of the polymer film, suitable for fabric handling, good swelling in the steamer, and easy washing off.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23692006

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12503-12512

Titre :	Pharmaceutical salt formation guided by phase diagrams
Type de document :	texte imprimé
Auteurs :	Ka W. Lam, Auteur ; Jinjie Xu, Auteur ; Ka M. Ng, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12503-12512
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Phase diagram
Résumé :	Salt formation is frequently employed to improve the solubility and bioavailability of pharmaceutical compounds. Solid-liquid equilibrium (SLE) phase diagram that serves as the foundation for designing crystallization-based separation is introduced to facilitate the recovery of the desired salt form. Two poorly water-soluble drugs, each with two ionizable groups, were selected to demonstrate this phase diagram-guided approach. The first is pemetrexed with confirmed monosodium and disodium salt forms. The second drug is the orally administered dapsone for which no known salt form has been established. Dihydrochloric salt of dapsone was successfully formed alongside the experimental phase diagram. Its solubility was found to be 80 times higher than that of the parent drug. Caco-2 cell assays showed that the intestinal permeability of the dihydrochloric salt was as good as that of the parent drug, thus confirming the usefulness of the salt form.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23692005

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12496-12502

Titre :	Thermodynamic analysis on work transfer process of two gas streams
Type de document :	texte imprimé
Auteurs :	Jian - Qiang Deng, Auteur ; Ji - Quan Shi, Auteur ; Zao - Xiao Zhang, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12496-12502
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Thermodynamic analysis
Résumé :	A novel concept of gas-gas work exchanger (WE) is proposed for recovery of mechanical energy. Its thermodynamic process is analyzed by using the energy conservation law and the real gas's pressure-specific enthalpy diagram. An in-depth work evaluation model of the work transfer process is carried out. A simplified equation for quick forecast work recovery efficiency of a gas-gas work exchanger is derived. The performances of a gas-gas work exchanger are analyzed by predigesting some precondition. The work recovery efficiency of a gas—gas work exchanger is found to be lower than that of a liquid-liquid work exchanger, e.g., the work recovery efficiency of a diatomic molecule gas drops from 0.75 to 0.46 as the compression ratio is increased from 1.5 to 3.0. The higher compression rate results in more work loss. In the example case of this work, supposing the same nitrogen stream supplies the power for recovery, a three-stage recovery process can recover 79% more power than a single stage process. A low-pressure stream can be compressed and rise its temperature far higher than that of two original temperatures of the streams. It is a new approach to energy transfer driven by pressure difference and it is wholly different from the heat transfer in a heat exchanger (HE). A network combining WEs with HEs is proposed for recovering energy thoroughly and flexibly.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23692004

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12477-12495

Titre :	Improving the computational performance of STN / RTN formulations for short - term scheduling
Type de document :	texte imprimé
Auteurs :	Guillermo A. Durand, Auteur ; J. Alberto Bandoni, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12477-12495
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Scheduling Short term
Résumé :	In this article, we present a series of integer cuts to improve the computational performance of scheduling problems based on either discrete- or continuous-time representation. They are expressed as novel equations in terms of binary variables alone that take advantage of structural characteristic of general STN and RTN formulations. Different fixed pairs of tasks appearing in scheduling problems of continuous and batch-continuous processes are identified, and corresponding integer cuts are developed to improve the solution efficiency of the mathematical formulations. For demonstration purposes, five selected scheduling formulations are modified as proposed in this article and applied to three well-known benchmark problems, and their computational performances are compared against the unmodified formulations. An industrial case study is also used to demonstrate the advantages of using the new equations. This case study corresponds to a sector, the so-called "sugarhouse", of a beet sugar plant. The scheduling model is presented, and the results are discussed in terms of both the optimal plant schedule and the computational point of view.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23692003

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp12471–12476

Titre :	High - performance hybrid magnetorheological materials : preparation and mechanical properties
Type de document :	texte imprimé
Auteurs :	W. Zhang, Auteur ; X. L. Gong, Auteur ; S. H. Xuan, Auteur
Année de publication :	2011
Article en page(s) :	pp12471–12476
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Magnetorheological Mechanical properties
Résumé :	To improve mechanical performance of magnetorheological elastomers (MREs), two novel hybrid magnetorheological elastomers that were embedded with magnetorheological fluids (MRFs) and magnetorheological gels (MRGs) were fabricated. In this work, MRFs and MRGs were injected into different numbers of holes that were punched on MRE specimens regularly. The nonlinear mechanical properties of the as-prepared magnetorheological fluid-elastomers (MRFEs) and magnetorheological gel-elastomers (MRGEs) were investigated in the presence of external homogeneous magnetic fields. The modulus, loss factor, and hysteresis were evaluated with a modified dynamic mechanical analyzer (DMA) and vibrating sample magnetometer (VSM). Dependence of the rheological response on the volume fraction was also investigated. As the experimental results show, not only were the initial moduli of the two novel hybrid magnetorheological materials higher than those of both the MRFs and MRGs, but also their magnetorheological (MR) effects were better than those of MREs. The loss factors of the two new hybrids were different from those of traditional MREs. Moreover, their dynamic properties changed according to the different volume ratios of MRFs and MRGs injected into the MRE specimens. These results suggest that the two novel hybrid magnetorheological elastomers are improved systems with volume-fraction-dependent rheological responses and the mechanical properties of MREs can be improved by embedding them with MRFs and MRGs.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie101904f

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12461–12470

Titre :	Meniscus - shear particle detachment in foam - based cleaning of silicon wafers with an immersion / withdrawal cell
Type de document :	texte imprimé
Auteurs :	V. A. Andreev, Auteur ; J. M. Prausnitz, Auteur ; C. J. Radke, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12461–12470
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	silicon
Résumé :	New experimental data collected at Lam Research Corporation and theoretical analyses are presented for aqueous-foam cleaning of silicon wafers contaminated with strongly adhered 90 nm Si3N4 particles (Freer et al. 2010). We analyze the distribution of contaminant removal along the wafer surface and the influence of foam quality in a vertical rectangular slot upon wafer immersion/withdrawal. At zero foam quality, particle removal along the wafer surface is uniform. Increased foam quality leads to improved overall removal. Removal, however, is no longer uniform with larger detachment rates toward the bottom of the wafer. To explain the observed nonuniform particle removal, we adopt a binary-collision model that demands a linear dependence of removal rate on the surface shear rate. Perturbation analysis provides the distribution of the wall shear rate along the wafer surface in an unfoamed solution. Calculations show that the wall shear rate on the wafer surface is strongly peaked in the meniscus just above the liquid-filled slot. Thus, with no foam present, removal in the meniscus zone dominates the overall removal process. Because the time of exposure to this high shear is the same for all parts of the surface, we obtain uniform cleaning. With foam bubbles present, the wall shear rate in the slot is enhanced, leading to significant removal in the bulk of the slot. Because the residence time of a wafer in the bulk cleaning solution varies for different parts of the wafer, contaminant removal in the bulk of the slot depends on the vertical position. Combined particle removal in the meniscus zone and in the slot leads to the observed nonuniform distribution of contaminant particles remaining on the wafer surface. Increasing foam quality increases the slot wall shear rate and, hence, the removal rate inside the immersion/withdrawal cell.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie1012954

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12452-12460

Titre :	Comparison of the corrosion inhibitive effect of anaerobic and aerobic cigarette butts water extracts on N80 steel at 90 °C in hydrochloric acid solution
Type de document :	texte imprimé
Auteurs :	Jun Zhao, Auteur ; Ningsheng Zhang, Auteur ; Chengtun Qu, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12452-12460
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Steel Extract Aerobe Anaerobe Corrosion
Résumé :	The chemical compositions of cigarette butts water extracts mainly are aromatic amines including nicotine and its compounds. If oxygen exists, the aromatic amine compounds can be oxidized easily. Whether this oxidation would be beneficial in enhancing the corrosion inhibitive effect of the inhibitor is not known. In this study, the corrosion inhibitive effect of aerobic and anaerobic cigarette butts water extracts are compared on N80 steel at 90 °C in 15% (weight %) hydrochloric acid. The chemical compositions of the aerobic and anaerobic cigarette butts water extracts are also contrasted. Weight loss, X-ray diffraction, and electrochemical techniques (such as electrochemical noise, impedance, and potentiodynamic polarization) are used to evaluate the corrosion inhibitive effect of aerobic and anaerobic cigarette butts water extracts. Results show that the inhibition efficiency of the aerobic cigarette butts water extracts (92.9%) is higher than anaerobic cigarette butts water extracts (84.6%).
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23692000

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12444–12451

Titre :	Rubbery polymer − inorganic nanocomposite membranes : free volume characteristics on separation property
Type de document :	texte imprimé
Auteurs :	Ben Li, Auteur ; Dan Xu, Auteur ; Xiongfei Zhang, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12444–12451
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Nanocomposite Polymer inorganic
Résumé :	The rational design of polymer−inorganic nanocomposite membranes relies heavily on the precise insight and elaborate control of the interface. Presently, the direct exploration of the hierarchical structure of nanocomposite membranes still remains elusive. In the present study, we propose a facile and generic methodology to quantitatively probe the interfacial structure by complementary positron annihilation lifetime spectroscopy (PALS) and molecular dynamics simulation (MDS) techniques. MDS is used to acquire the molecular level information such as the polymer−inorganic interface interaction energy, chain mobility within the nanocomposite membranes, whereas PALS is used to acquire the free volume characteristics of the nanocomposite membranes. As proof-of-principle, we choose anisotropic inorganic nanotube embedded rubbery polymer membrane as a model, which generates the interface between soft polymer and rigid inorganic. PALS reveals that incorporation of titanate nanotubes (TNTs) narrows the free volume pore radius distribution of the membranes. MDS indicates that the segmental chain mobility in the vicinity of the polymer−inorganic interface is substantially restrained, which creates numerous nanosized voids for molecular transport, and dramatically enhances the fractional free volume (FFV) of the membranes. Quite interestingly, it was found that the rubbery membranes can also exhibit simultaneously increased permeability and membrane selectivity, and this unusual phenomenon was tentatively elucidated by relating the separation properties to the free volume characteristics of the membranes.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie101142b

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12435–12443

Titre :	Stable citrate - coated iron oxide superparamagnetic nanoclusters at high salinity
Type de document :	texte imprimé
Auteurs :	Csaba Kotsmar, Auteur ; Ki Youl Yoon, Auteur ; Haiyang Yu, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12435–12443
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Superparamagnetic nanoclusters
Résumé :	Superparamagnetic nanoclusters may be used in imaging in biomedicine and in mapping of petroleum reservoirs, by generating either ultrasonic or acoustic signals with oscillating magnetic motion. For a given magnetization per weight of iron oxide, nanoclusters with diameters from 20 to 100 nm experience a much larger magnetic force than that of the primary sub-10-nm primary particles. Aqueous dispersions of 0.1 wt % superparamagnetic iron oxide nanoclusters were stabilized with citric acid on the particle surface, with a high loading of 90% iron oxide. The dispersions were stable for months even with high salt concentrations up to 4 wt % at a pH of 6 and 8 based on the hydrodynamic diameter from dynamic light scattering. The citrate ligands provide electrostatic repulsion, as characterized by the ζ potential. The small size of the clusters, superparamagnetic properties, and high salt tolerance are highly beneficial in various applications including the mapping of petroleum reservoirs with magnetomotive techniques.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie1010965

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp.12429-12434

Titre :	Ca(OH)2 superheating as a low - attrition steam reactivation method for CaO in calcium looping applications
Type de document :	texte imprimé
Auteurs :	Vlatko Materic, Auteur ; Susan Edwards, Auteur ; Stuart I. Smedley, Auteur
Année de publication :	2011
Article en page(s) :	pp.12429-12434
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Attrition rate Calcium Carbonation/calcination cycle Dehydration Dehydration reactions Dewatering Fluid-beds Fluidization Free lime Heat storage Hydration Initiation temperature Lime Non equilibrium Reactivation process Sorption Steam Steam hydration Superheated state Temperature Thermodynamic equilibria water vapor
Résumé :	Steam hydration of lime is an effective method for restoring CO2 capture activity but gives rise to high particle attrition rates in a fluid bed reactor. This paper describes the phenomenon of Ca(OH)2 superheating, also referred to as superheated dehydration (SD). The potential of an attrition-free lime reactivation process using this phenomenon is also investigated. Attrition rates of the sorbent are measured when a reactivation step using steam hydration is implemented every three carbonation/calcination cycles. It has been shown that the presence of CO2 during the dehydration step reduces attrition during subsequent cycles. Experiments performed in a small fluid bed reactor show that the presence of 40-100% CO 2 during the dehydration step increases the initiation temperature of the decomposition of Ca(OH)2 from 445 to 618 °C. The thermodynamic equilibrium water vapor pressure for the dehydration reaction at 618 °C is 516 kPa, whereas no water vapor was detected in the reactor during the dehydration step before the temperature reached 618 °C. Under these circumstances it is proposed that the Ca(OH)2 is in a nonequilibrium "superheated state". A CO2 capture cycling experiment, with a reactivation step every three carbonation/calcination cycles, maintained an average activity of 60%, creating only 3.25% of fines < 150 μm after 28 carbonations. The reactivation step consisted of hydrating the sorbent at a temperature of 270 °C and dehydrating it in 100% CO2 with a 23 min hold at 520 °C. It is proposed that the SD phenomenon may be a key step in the development of an industrially feasible method of lime reactivation for use in CO2 capture and in thermal energy storage applications. © 2010 American Chemical Society.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://www.irl.cri.nz/caoh2-superheating-low-attrition-steam-reactivation-method [...]

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12423-12428

Titre :	Synthesis of Ni - SiO2/silicalite -1 core - shell micromembrane reactors and their reaction / diffusion performance
Type de document :	texte imprimé
Auteurs :	Easir A. Khan, Auteur ; Arvind Rajendran, Auteur ; Zhiping Lai, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12423-12428
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Diffusion Reactor
Résumé :	Core—shell micromembrane reactors are a novel class of materials where a catalyst and a shape-selective membrane are synergistically housed in a single particle. In this work, we report the synthesis of micrometer -sized core-shell particles containing a catalyst core and a thin permselective zeolite shell and their application as a micromembrane reactor for the selective hydrogenation of the 1-hexene and 3,3-dimethyl-1-butene isomers. The bare catalyst, which is made from porous silica loaded with catalytically active nickel, showed no reactant selectivity between hexene isomers, but the core-shell particles showed high selectivities up to 300 for a 1-hexene conversion of 90%.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23691996

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12414-12422

Titre :	Epoxy resins cross - linked with rosin adduct derivatives. cross - linking and thermal behaviors
Type de document :	texte imprimé
Auteurs :	Fanica R. Mustata, Auteur ; Nita Tudorachi, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12414-12422
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Rosin adduct derivatives
Résumé :	Rosin adduct derivatives were obtained by chemical reaction of the Diels—Alder adduct of rosin acid with maleic anhydride (RAMA) with aspartic acid (ASP) and p-aminobenzoic acid (p-ABA), at 1/1 molar ratio. The structure of the obtained monomers was established by means of elemental analysis, FT-IR spectroscopy, and 1H NMR. These acids were used as cross-linking agents, in the presence of triethylbenzylammonium chloride as catalyst (TEBAC) for diglycidyl monomers (diglycidyl ether of bisphenol A, DGEBA, and diglycidyl ether of hydroquinone, DGEHQ). Using differential scanning calorimetry (DSC) at different heating rates and the literature methods, the kinetic parameters of cross-linking reactions were obtained. The thermal stability of the cross-linked polymers investigated by using thermogravimetric analysis (TGA) showed they are reasonably thermostable.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie101746v

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12405–12413

Titre :	Fe2+ - Catalyzed wet oxidation of phenolic acids under different pH values
Type de document :	texte imprimé
Auteurs :	Sergio Collado, Auteur ; David Quero, Auteur ; Adriana Laca, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12405–12413
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Catalytic oxidation Aqueous phase
Résumé :	Catalytic oxidation in the aqueous phase of phenol and phenol-derivates present in pharmaceutical wastewaters has been investigated using FeSO4·7H2O as a homogeneous catalyst at 413 K and 1.0 MPa. Different initial pH values and catalyst concentrations have been tested, and the results obtained have been discussed taking into account the different roles that the iron plays depending on the pH value and the phenolic compound studied. The degradation rate of each pollutant assayed and the degree of mineralization achieved during the wet oxidation process were greatly affected by pH. The catalytic effect of iron(II) during the wet oxidation of phenol was only observed at pH values ranging between 2 and 3, due to the establishment of a Fe(III)/Fe(II) redox cycle. However, the best results for the catalytic oxidation of salicylic acid were obtained for pH values below 2, and they were related to the formation of an Fe(II)−salicylic acid complex. On the other hand, the presence of iron(II) had a prejudicial effect on the degradation of p-hydroxybenzoic and 5-hydroxyisophthalic acids, provoking the apparition of induction periods in both cases, due to the competition between the autoxidation of Fe(II) and the hydroxylation of the phenolic compound by the initial OH•.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie101497s

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12399-12404

Titre :	Etherification of glycerol with isobutylene to produce oxygenate additive using sulfonated peanut shell catalyst
Type de document :	texte imprimé
Auteurs :	Weiqin Zhao, Auteur ; Bolun Yang, Auteur ; Chunhai Yi, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12399-12404
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Catalyst Additive Etherification
Résumé :	A carbon-based solid acid catalyst was prepared by sulfonation of partially carbonized peanut shell, and characterized by SEM, EDS, BET analysis, FTIR spectroscopy, NH3 TPD, and TGA. The analytic results indicate that sulfonated peanut shell catalyst has an amorphous porous structure with a high acid capacity and good thermal stability and exhibits better catalytic activity for the glycerol etherification reaction than cation-exchange resin. With a molar ratio of isobutylene to glycerol of 4: a catalyst-to-glycerol mass ratio of 6 wt %, a reaction temperature of 343 K, and a reaction time of 2 h, glycerol was completely transformed into a mixture of glycerol ethers including mono-tert-butylglycerols (MTBGs), di-tert-butylglycerols (DTBGs), and tri-tert-butylglycerol (TTBG), and the selectivity toward the sum of the desired DTBGs and TTBG of 92.1% was obtained. Moreover, excellent reusability of the catalyst was also confirmed by repeated experiments.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23691993

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12390–12398

Titre :	Process engineering study of the homogenously catalyzed biodiesel synthesis in a bubble column reactor
Type de document :	texte imprimé
Auteurs :	Thomas Mollenhauer, Auteur ; Walther Klemm, Auteur ; Manfred Lauterbach, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12390–12398
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Bubble column reactor Catalyzed biodiesel
Résumé :	A bubble column reactor has been developed for the production of fatty acid methyl ester (FAME) from refined oil and oil with high free fatty acid (FFA) content. The aim of our investigations was to examine the basic use of a discontinuously operated bubble reactor for homogenously catalyzed synthesis of FAME in comparison to use of a discontinuously operated stirred reactor. Stirring of the liquid phase in the bubble reactor was realized by the ascending force of bubbles which were introduced over a distribution system from the bottom of the reactor. Either the aerating nitrogen gas (at 60 °C) or vaporized methanol (at 80 °C) were used in the bubble reactor. The ascending bubbles should enable the mass transfer for transesterification and esterification of the feedstock. Further, the catalysts p-toluene sulfonic acid (p-TSS; 3 wt %) or sodium methoxide (1 wt %) were applied to an initial load of 2 L in a molar ratio of 2:1 methanol-to-feedstock related to the fatty acids. Additionally, important process engineering parameters and kinetic information were collected experimentally as well as theoretically. The results show that a bubble reactor is a serious alternative reaction technique for FAME production simplifying the devices and enabling higher throughputs per reaction unit.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie101430w

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12383-12389

Titre :	Ethanol steam reforming over Rh (1%) MgAl 2O4/ Al2O3 : a kinetic study
Type de document :	texte imprimé
Auteurs :	Cecilia Graschinsky, Auteur ; Miguel Laborde, Auteur ; Norma Amadeo, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12383-12389
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Kinetics Steam reforming
Résumé :	A kinetic study of ethanol steam-reforming reaction on Rh catalyst supported over a spinel structure (MgAl2O4/ Al2O3) was carried out. From the analysis of products distribution, the following four reactions were proposed as the reaction scheme: C2H5OH → CO + CH4 + H2 (ED), C2H5OH + H2O → CO2 + CH4 + 2H2 (ER), water-gas shift reaction, and methane steam-reforming reaction. When the initial rate method was applied, it was demonstrated that in the rate-determining step (RDS) two active sites of the same type are involved. With use of our experimental results and data obtained from the literature, a sequence of 14 elementary steps were proposed, in agreement with the reaction scheme. Taking into account both the reaction mechanism and the occurrence of two active sites in the RDS, four different kinetic expressions can be formulated in which the RDS is (1) dissociative adsorption of ethanol, (2) dehydrogenation of ethoxide, (3) C-C bond scission, or (4) reaction between two adsorbed species. Finally, when discrimination models were applied, it was verified that the mechanism that fits experimental data is that in which the RDS is the surface reaction.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23691991

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12379–12382

Titre :	Investigation of the dissolution kinetics of meta - kaolin in H2SO4 solution
Type de document :	texte imprimé
Auteurs :	Mehmet Riza Altiokka, Auteur ; Handan Akalin, Auteur ; Nergis Melek, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12379–12382
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	kinetics
Résumé :	Kaolin with a given size distribution was calcined at 1023 K for 2 h then digested in 3.0, 4.5, and 6.0 N sulfuric acid at constant temperatures within the range 328−358 K. The samples taken from the solution at predetermined time intervals were analyzed by using a complexometric method and the amount of aluminum passed into the solution was determined. The results showed that the dissolution kinetics follow the shrinking core model for spherical particles of unchanging size, t/τ = 1 − (1 − xB)1/3, with the apparent activation energy of 98.4 kJ/mol. The leaching reaction was found to be the 0.75th order with respect to acid concentration and controlled by reaction step.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie101147n

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12371–12378

Titre :	Kinetics of methanol transformation into hydrocarbons on a HZSM - 5 zeolite catalyst at high temperature (400 - 550 °C)
Type de document :	texte imprimé
Auteurs :	Andrés T. Aguayo, Auteur ; Diana Mier, Auteur ; Ana G. Gayubo, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12371–12378
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Kinetics Zeolite catalyst
Résumé :	A kinetic model of seven lumps has been established which allows the quantification of the product distribution (oxygenates, n-butane, C2−C4 olefins, C2−C4 paraffins (without n-butane), C5−C10 fraction, methane) in the transformation of methanol into hydrocarbons at high temperature (400−550 °C) on a HZSM-5 zeolite catalyst (SiO2/Al2O3 = 30) with high acidic strength (>120 kJ (mol of NH3)−1) and agglomerated with bentonite and alumina. The kinetic model fits well the experimental data obtained in a fixed bed reactor, from small values of space time in which the formation of hydrocarbons is incipient, to a space time of 2.4 (g of catalyst) h (mol CH2) −1 for a complete conversion of methanol. The rise in temperature increases the yield of C2−C4 olefins, so that the maximum value (50%) is obtained at the ceiling temperature for the hydrothermal stability of the HZSM-5 (550 °C) and space times between 0.6 and 1 (g of catalyst) h (mol CH2)−1.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie101047f

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp.12365–12370

Titre :	Dehydrogenation of isopropanol on copper - containing mesoporous catalysts
Type de document :	texte imprimé
Auteurs :	Nancy F. Balsamo, Auteur ; Corina M. Chanquia, Auteur ; Eduardo R. Herrero, Auteur
Année de publication :	2011
Article en page(s) :	pp.12365–12370
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Mesoporous catalysts
Résumé :	Copper-containing mesoporous catalysts with an MCM-41 type structure have been prepared using direct hydrothermal synthesis and characterized using XRD, AAS, N2 adsorption−desorption, DRUV−vis, and TEM. All of the samples showed high structural regularity and surface area. Three copper species are presented in these materials: isolated mononuclear Cuδ+ species, oligonuclear [Cuδ+···Oδ−···Cuδ+]n clusters, and bulky CuO oxides. These materials were catalytically tested in isopropanol dehydrogenation, showing good activity and very high selectivity to propanone at 300 °C. A further reduction treatment of the samples allowed us to suggest possible active species. Both the [Cuδ+···Oδ−···Cuδ+]n clusters and the isolated Cuδ+ cations seem to be the species responsible for isopropanol dehydrogenation.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100972h

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12358-12364

Titre :	Kinetic modeling of liquid phase photocatalysis on supported TiO2 nanoparticles in a rectangular flat - plate photoreactor
Type de document :	texte imprimé
Auteurs :	A. R. Khataee, Auteur ; M. Fathinia, Auteur ; S. Aber, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12358-12364
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Modeling Photochemical reactor Flat plate Nanoparticle Titanium oxide Photocatalysis Liquid phase Kinetic model
Résumé :	The photocatalytic degradation of C.I. Basic Blue 3 (BB3) in water on supported TiO2 nanoparticles was carried out in a rectangular flat-plate photoreactor. The photocatalytic degradation kinetic characteristics were experimentally investigated under different light intensities and initial dye concentrations. Calculating corresponding "apparent adsorption constants", Ks, and "apparent rate constants", kr, of experimental results according to the Langmuir-Hinshelwood (L-H) model emphasized that the L-H constants varied with regard to the light intensity. A new kinetic model was developed on the basis of the intrinsic element reactions, which took into account the effect of light intensity, reaction intermediates, organic compound content, and first order reaction kinetics. The new kinetic model described the experimental results in a more accurate way and explained consistently the dependence of the apparent kinetic parameters kr and Ks on the light intensity.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23691987

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12352-12357

Titre :	Application of sulfonated carbon - based catalyst for reactive extraction of 1,3-propanediol from model fermentation mixture
Type de document :	texte imprimé
Auteurs :	Panatpong Boonoun, Auteur ; Navadol Laosiripojana, Auteur ; Chirakarn Muangnapoh, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12352-12357
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Fermentation Modeling Catalyst
Résumé :	This study deals with the possibility of the application of a low-cost sulfonated carbon-based catalyst for reactive extraction to separate 1,3-propanediol (1,3-PDO) from a model solution of 1,3-PDO biologically derived from glycerol. The catalyst was synthesized by incomplete carbonization of naphthalene in sulfuric acid, and was demonstrated to be active for the acetalization of 1,3-PDO with acetaldehyde in aqueous solution. The performance of the reactive extraction process by using a sulfonated carbon-based catalyst was proven to be excellent based on the percent recovery rate of 1,3-PDO. These results along with those on the catalyst reactivity demonstrate that the carbon-based catalyst can be used to replace expensive commercial catalysts currently used such as Dowex 50-WX4-200 and Amberlite IR120.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23691986

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp.12345–12351

Titre :	Y - Al2O3 modified with praseodymium : an application in the heterogeneous catalytic ozonation of succinic acid in aqueous solution
Type de document :	texte imprimé
Auteurs :	Zhiqiao He, Auteur ; Angliang Zhang, Auteur ; Shuang Song, Auteur
Année de publication :	2011
Article en page(s) :	pp.12345–12351
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Catalytic ozonation Succinic acid Aqueous solution
Résumé :	In an attempt to utilize ozone effectively, a series of praseodymium-modified γ-Al2O3 (Pr/Al2O3) was prepared via incipient wetness impregnation using Pr(NO3)3·6H2O as the precursor. The structure and properties of the catalysts were studied by X-ray diffraction (XRD) and the Brunauer−Emmett−Teller (BET) method. Catalytic activity was evaluated by monitoring the degradation of succinic acid (SA) in the presence of ozone. The praseodymium modification can effectively enhance the ozonation activity of γ-Al2O3 upon SA removal. Increasing the calcination temperature of Pr/Al2O3 is disadvantageous for the catalytic process, whereas increasing the load of praseodymium is helpful. After three successive cycles, the Pr/Al2O3 catalyst remained stable in the catalytic ozonation of SA. Overall, the initial degradation rate of SA, as well as the saturated adsorption capacity of SA, were found to have a linear relation to changes of the surface hydroxyl groups of the catalyst. On this basis, we conclude that the significant enhancement of SA degradation using Pr/Al2O3 as a catalyst should be because praseodymium, in the form of Pr6O11, promoted the formation of surface hydroxyl groups. Hence, the adsorption was increased, and the degradation rate of SA was enhanced.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie101233h

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12339-12344

Titre :	Design and analysis of experiments for obtaining high bulk density sodium tripolyphosphate
Type de document :	texte imprimé
Auteurs :	Marcin Banach, Auteur ; Zygmunt Kowalski, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12339-12344
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Bulk density Design
Résumé :	The results of experiments for obtaining granulated sodium tripolyphosphate with bulk density adjustable within 1.00-1.05 kg/dm3 and expected content of STPP crystalline phases are presented. The scope of experiments included the identification of factors with statistically significant impacts on the study object and the estimation of response surface. Because of the application of the Plackett-Burman design, 15 input factors could be evaluated regarding their impact significance and insignificant factors could be eliminated. Moreover, the Hartley design enabled the determination of a response surface based on the general regression equation in the form of a second degree polynomial with double interactions. The input factor values, determined on the basis of the prediction profile and desirability function, were used to perform a series of experiments to achieve STPP expected bulk density within the range of 1.00-1.05 kg/dm3.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23691984

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 24 (Décembre 2010) . - pp. 12333-12338

Titre :	New catalysts for the borohydride dyeing process
Type de document :	texte imprimé
Auteurs :	N. Meksi, Auteur ; M. Ben Ticha, Auteur ; M. Kechida, Auteur
Année de publication :	2011
Article en page(s) :	pp. 12333-12338
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Catalyst
Résumé :	In the borohydride dyeing process, indigo cannot be reduced by sodium borohydride to its reduced form without the addition of catalyst. This catalyst, which is a metallic salt, is used to activate the reduction procedure of the reducing agent. So, the reduction reaction of indigo depends significantly on the nature of this catalyst. In this paper, the effect of 12 different metallic salts on the performances of the indigo reduction reaction has been discussed. These performances were evaluated by measuring the indigo reduction yield as well as the color yield (K/S) of the dyed samples of cotton. In these studies, it was found that the copper-based catalysts were the best and offered maximum performance.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23691983

Industrial & engineering chemistry research / Paul, Donald R. . Vol. 49 N° 24

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