Catalogue en ligne Bibliothèque Ecole Nationale Polytechnique d'Alger

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 16157-16161

Titre :	Isoconversional kinetic analysis of complex solid-state processes : Parallel and successive reactions
Type de document :	texte imprimé
Auteurs :	Junmeng Cai, Auteur ; Weixuan Wu, Auteur ; Ronghou Liu, Auteur
Année de publication :	2013
Article en page(s) :	pp. 16157-16161
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Résumé :	A critical study of the use of the iterative linear integral isoconversional method for a parallel reactions process and a successive reactions process has been performed using theoretical simulated nonisothermal data. The activation energies obtained for these complex processes show a strong dependence on the range of heating rates, which is against the assumptions of isoconversional methods. Therefore, a systematic kinetic analysis for discriminating the reactions rather than merely assuming that the activation energy varies with the conversion would be required for understanding the reaction mechanism of these processes.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26732141

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 16151–16156

Titre :	Rheo-Raman : A Promising Technique for In Situ Monitoring of Polymerization Reactions in Solution
Type de document :	texte imprimé
Auteurs :	Marie-Claire Chevrel, Auteur ; Sandrine Hoppe, Auteur ; Laurent Falk, Auteur
Année de publication :	2013
Article en page(s) :	pp. 16151–16156
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Polymerization Acrylic acid
Résumé :	The use of a laboratory-made rheo-Raman device for continuous in situ monitoring of free-radical polymerization of acrylic acid in aqueous solution is reported for the first time. Combining a mixer-type rheometer with a quartz outer cylinder to a Raman spectrometer, this original experimental device has allowed us to overcome three current challenges of polymerization reaction monitoring. First, monomer conversion, polymer formation, and viscosity of reaction medium were continuously monitored with well-defined conditions (composition, temperature, and flow), using Couette analogy. Second, direct correlation between macroscopic viscosity and medium composition was established (accounting for the continuous variation of molar mass distribution). Third, using a mixer-type rheometer provided scalable results, in terms of stirring conditions.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie302054k

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 16146-16150

Titre :	Mitigation of VX effluents in thorough decontamination operations
Type de document :	texte imprimé
Auteurs :	George W. Wagner, Auteur ; Roberta Xega, Auteur
Année de publication :	2013
Article en page(s) :	pp. 16146-16150
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Decontamination Pollution abatement
Résumé :	Effluents resulting from the decontamination of VX from CARC-painted panels using DF200 have been studied to determine the presence of toxic species. The effect of concrete and sand (two possible sump materials) on the effluents is also examined. Wash-effluents, generated by washing the panel with hot soapy water prior to decontamination, contain high levels of VX which slowly hydrolyze to nontoxic EMPTA, EMPA, and toxic EA-2192, with concrete tending to minimize formation of the latter. Rinse-effluents, generated following decontamination, contain lower levels of VX which tend to fall below acceptable levels (20 ppb) within several hours in contact with sand. VX in rinse-effluents in contact with concrete persists for up to a week, consistent with the decomposition by concrete of active H2O2 in any residual DF200. EA-2192 persists for at least a week in rinse—effluents—in contact with either sand or concrete. Lining sump pits with HTH is a possible mitigation strategy as this decontaminant readily oxidizes residual VX, EA-2192, and even EMPTA to nontoxic EMPA and MPA.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26732139

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 16135-16145

Titre :	Novel cellulose esters for forward osmosis membranes
Type de document :	texte imprimé
Auteurs :	Rui Chin Ong, Auteur ; Tai-Shung Chung, Auteur ; Bradley J. Helmer, Auteur
Année de publication :	2013
Article en page(s) :	pp. 16135-16145
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Osmosis
Résumé :	Syntheses and evaluation of novel cellulose esters consisting of a wide range of chemical compositions targeted for forward osmosis membrane fabrication have been carried out. Preliminary studies on the effects of the degree of substitution of hydroxyl, acetyl, and propionyl or butyryl functional groups on the membrane formation and permeation characteristics were conducted. Experiments results show that cellulose esters with high content of hydrophobic functional groups content exhibit great salt rejection, because of low water solubility and small hydrated free volume of hydrophobic cellulose esters. However, as the content of bulky hydrophobic functional groups increases, there is an accompanying increase in free volume due to poor chain packing, which causes a decrease in salt rejection. A high OH content in cellulose esters results in membranes with high salt and water permeation. Among the evaluated cellulose esters, those which have the highest hydrophobicity are unable to form membranes with defect-free selective layers via normal phase inversion casting conditions.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26732138

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 16116–16134

Titre :	Coarse-graining approach to infer mesoscale interaction potentials from atomistic interactions for aggregating systems
Type de document :	texte imprimé
Auteurs :	Sergiy Markutsya, Auteur ; Rodney O. Fox, Auteur ; Shankar Subramaniam, Auteur
Année de publication :	2013
Article en page(s) :	pp. 16116–16134
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Aggregating systems Atomistic
Résumé :	A coarse-graining (CG) approach is developed to infer mesoscale interaction potentials in aggregating systems, resulting in an improved potential of mean force for Langevin dynamics (LD) and Brownian dynamics (BD) simulations. Starting from the evolution equation for the solute pair correlation function, this semi-analytical CG approach identifies accurate modeling of the relative acceleration between solute particles in a solvent bath as a reliable route to predicting the time-evolving structural properties of nonequilibrium aggregating systems. Noting that the solute–solvent pair correlation function attains a steady state rapidly as compared to characteristic aggregation time scales, this CG approach derives the effective relative acceleration between a pair of solute particles in the presence of this steady solute–solvent pair correlation by formally integrating the solvent force on each solute particle. This results in an improved potential of mean force that explicitly depends on the solute–solute and solute–solvent pair potentials, with the capability of representing both solvophilic and solvophobic interactions that give rise to solvation forces. This approach overcomes the difficulty in specifying the LD/BD potential of mean force in aggregating systems where the solute pair correlation function evolves in time, and the Kirkwood formula U(r) = −kBT ln g(r) that is applicable in equilibrium diffusion problems cannot be used. LD simulations are compared to molecular dynamics (MD) simulations for a model colloidal system interacting with Lennard-Jones pair potentials to develop and validate the improved potential of mean force. LD simulations using the improved potential of mean force predict a solute pair correlation function that is in excellent match with MD in all aggregation regimes, whereas using the unmodified MD solute–solute pair potential in LD results in a poor match in the reaction-limited aggregation regime. The improved potential also dramatically improves the predicted extent of aggregation and evolution of cluster size distributions that exhibit the same self-similar scaling found in MD. This technique of coarse-graining MD potentials to obtain an improved potential of mean force can be applied in a general multiscale framework for nonequilibrium systems where the evolution of aggregate structure is important.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3013715

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 16101-16115

Titre :	Review of existing QSAR/QSPR models developed for properties used in hazardous chemicals classification system
Type de document :	texte imprimé
Auteurs :	Flor A. Quintero, Auteur ; Suhani J. Patel, Auteur ; Felipe Munoz, Auteur
Année de publication :	2013
Article en page(s) :	pp. 16101-16115
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Modeling Property structure relationship
Résumé :	The development of a globally harmonized system (GHS) on an international level requires various countries to classify chemicals according to hazardous properties using similar categories. The classification criteria include physical, toxic (health), and environmental properties. The GHS is also being included in the U.S. regulations through the Notice of Proposed Rulemaking issued in September 2009 by the Occupational Safety & Health Administration (OSHA). It has been suggested in the rulemaking that, in cases where experimental data are not available to predict some types of hazard, quantitative structure― activity relationships/quantitative structure―property relationships (QSAR/QSPR) can be applied as found necessary. Any chemical or physical property of the material can be related to information within an individual molecule and its structure, thereby developing prediction models such as QSAR and QSPR. This review examines the work published for QSARs/QSPRs (in addition to previously published reviews) on the prediction of some of the hazardous properties for selected hazard classes within the GHS regulation. These models are powerful but, at times, are limited in application for some types of compounds and properties. The development of extensive models will greatly enhance the need for hazardous classifications of chemicals.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26732136

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 16092-16100

Titre :	Nonlinear PLS integrated with error-based LSSVM and its application to NOx modeling
Type de document :	texte imprimé
Auteurs :	You Lv, Auteur ; Jizhen Liu, Auteur ; Tingting Yang, Auteur
Année de publication :	2013
Article en page(s) :	pp. 16092-16100
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Modeling
Résumé :	This article presents a novel nonlinear partial least-squares (PLS) method to address a nonlinear problem with input collinearity in an industrial process. The proposed method integrates an inner least-squares support vector machine (LSSVM) function with an outer linear PLS framework. First, the input and output latent variables are extracted to eliminate the collinearity through PLS projection, and then LSSVM is used to construct nonlinear relation between each pair of latent variables. Moreover, a weight-updating procedure is incorporated to enhance the accuracy of prediction. Then, training and predicting algorithms based on modified nonlinear iterative partial least-squares (NIPALS) steps are also described in detail. The performance of the new method is also investigated with a benchmark data set. Finally, this approach is applied to a real industrial process to predict the NOx emissions of a coal-fired boiler. The root-mean-square errors (RMSEs) on the training and testing data decreased to only 12.6632 and 37.6609, respectively. Compared with the original linear PLS and other kinds of nonlinear PLS methods, a reduction of approximately 40.8―47.4% in the prediction errors is attained. The results reveal that the new approach is capable of modeling the nonlinear relation of NOx emissions with other process parameters and improving the prediction performance.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26732135

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 16085–16091

Titre :	Evaluation of the separation of liquid–liquid dispersions by flow through fiber beds
Type de document :	texte imprimé
Auteurs :	Dragan D. Govedarica, Auteur ; Radmila M. Secerov Sokolovic, Auteur ; Dunja S. Sokolovic, Auteur
Année de publication :	2013
Article en page(s) :	pp. 16085–16091
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Liquid Liquid Dispersions Fiber
Résumé :	The liquid–liquid model dispersions encompassing four mineral oils of different properties were separated using polyurethane fibers. Experiments were carried out over a wide range of oil properties, bed permeabilities, and fluid velocities. The objective was to introduce multivariate analysis as a statistical method for the estimation of the efficiency of separation of liquid–liquid dispersions by flow through fiber beds. The bed coalescence efficiency was followed by monitoring the changes of critical velocity. On the basis of the principal component analysis, reduced dimensionality and a lower number of variables, an improved statistical treatment of the measurement data was performed. An empirical equation was derived describing the critical velocity as a function of the oil viscosity, interfacial tension, dielectric constant, emulsivity, and bed permeability.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3026967

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 16074-16084

Titre :	Optimization of membrane fouling using experimental design : An example from dairy wastewater treatment
Type de document :	texte imprimé
Auteurs :	Reyhan Hepsen, Auteur ; Yasemin Kaya, Auteur
Année de publication :	2013
Article en page(s) :	pp. 16074-16084
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Waste water purification Experimental design Fouling Optimization
Résumé :	The aim of the present study was to investigate the advanced treatment and reuse of dairy industry wastewater using an integrated membrane process that involves nanofiltration (NF) and reverse osmosis (RO). The Taguchi L16 (44) experimental design was used to determine the optimal conditions for the NF process used in the first phase of this study. The following parameters were selected for optimization of the experimental conditions: NF membrane type (NF 90, Desal 5DL, FM NP010, or NF 270), pH (4, 6, 8, or 10), temperature (20, 25, 30, or 35 °C), and transmembrane pressure (TMP; 12, 16, 20, or 24 bar). Membrane fouling was optimized by calculating the signal-to-noise (S/N) ratio of the parameters. Analysis of variance (ANOVA) was applied, and the results revealed that the pH is the most effective factor. A confirmation experiment performed under the optimum conditions showed good agreement between the observed and calculated results. In addition, the fouling on the membrane was also evaluated by atomic force microscopy (AFM) and contact-angle measurements. In the second phase of this study, the composite permeate obtained from the confirmation experiment in the first part was further purified for reuse with an RO membrane under TMPs of 20 and 40 bar.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26732133

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 16066–16073

Titre :	COSMO-RS studies : Structure–property relationships for CO2 capture by reversible ionic liquids
Type de document :	texte imprimé
Auteurs :	Maria Gonzalez - Miquel, Auteur ; Manish Talreja, Auteur ; Amy L. Ethier, Auteur
Année de publication :	2013
Article en page(s) :	pp. 16066–16073
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Ionic liquids
Résumé :	The quantum-chemical approach COSMO-RS was used to develop structure–property relationships of reversible ionic-liquid (RevIL) solvents for CO2 capture. Trends predicted for the thermodynamic properties of the RevILs using COSMO-RS, such as CO2 solubility, solvent regeneration enthalpy, and solvent reversal temperature, were verified by experimental data. This method was applied to a range of structures, including silylamines with varying alkyl chain lengths attached to the silicon and amine functionality, silylamines with fluorinated alkyl chains, sterically hindered silylamines and carbon-based analogues. The energetics of CO2 capture and release and the CO2 capture capacities are compared to those of the conventional capture solvent monoethanolamine. The results of this study suggest that the simple COSMO-RS computational approaches reported herein can act as a guide for designing new RevILs. COSMO-RS allows for the determination of the relative thermodynamic properties of CO2 in these and related systems.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie302449c

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 16059–16065

Titre :	Study of adsorptive denitrogenation of diesel fuel over mesoporous molecular sieves based on breakthrough curves
Type de document :	texte imprimé
Auteurs :	Han Zhang, Auteur ; Haiyan Song, Auteur
Année de publication :	2013
Article en page(s) :	pp. 16059–16065
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Diesel fuel
Résumé :	Adsorptive denitrogenation of model fuel and commercial diesel containing organic nitrogen compounds was studied over three typical mesoporous molecular sieves (Ti-HMS, HMS, and MCM-41) in a fixed-bed adsorption system at ambient pressure. The adsorbents were characterized by X-ray diffraction, UV–visible spectroscopy, transmission electron microscopy, N2 physical adsorption–desorption, and temperature-programmed NH3 desorption techniques. The adsorption capacities for various compounds (pyridine, quinoline, pyrrole, and indole) were examined and compared on the basis of the breakthrough curves, which provided insight into the adsorption behaviors over the different adsorbents. It is shown that the breakthrough time is shortened at increased temperature and liquid hourly space velocity (LHSV). The adsorption performance of HMS and Ti-HMS depends dominantly on the acid–base interaction. In addition, the polarity of the adsorbate is another factor that influences the adsorption capacity. The introduction of Ti improves the acidity of Ti-HMS, which thus exhibits a higher adsorption capacity than HMS, as confirmed by UV–visible spectroscopy and temperature-programmed NH3 desorption. The adsorption performance of nonacidic MCM-41 depends principally on the molecular weight of the adsorbate. For commercial diesel, the adsorption competition between sulfur and nitrogen compounds influences the adsorption of total nitrogen.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie302169r

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 16049-16058

Titre :	Adsorption of proteins onto ion-exchange chromatographic media : A molecular dynamics study
Type de document :	texte imprimé
Auteurs :	Juan Liang, Auteur ; Georg Fieg, Auteur ; Frerich J. Keil, Auteur
Année de publication :	2013
Article en page(s) :	pp. 16049-16058
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Molecular dynamics method Ion exchange Adsorption
Résumé :	Molecular dynamics (MD) simulations with coarse-grained models are used to investigate the adsorption process of proteins onto an ion-exchange chromatographic medium. The adsorption of human serum albumin (HSA) and bovine hemoglobin (bHb) on the anion exchanger Q Sepharose FF is studied. These two proteins have similar molecule sizes with different isoelectric points. To obtain a reliable set of data, simulations with different initial conditions are carried out for each protein. Convincingly, the results of the MD simulations are qualitatively consistent with those of previous experiments. HSA reaches a stable adsorption in all simulations, while the binding sites can differ. In contrast, bHb reaches a stable adsorption only in one simulation. Due to the stronger protein—ligand interaction of HSA, it adsorbs faster, stronger, and with more binding sites onto QSepharose FF than bHb. The spatial movements during the adsorption process and the adsorbed states are investigated in detail. Moreover, we studied the underlying physical relevance of two parameters (characteristic charge and steric factor) of the steric mass action (SMA) model for HSA and for bHb with MD simulations and compared them with the results of experiments. The results reveal that MD simulations are useful to interpret the physical consistence of the SMA parameters.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26732130

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 16042-16048

Titre :	Sequential SO2/CO2 capture of calcium-based solid waste from the paper industry in the calcium looping process
Type de document :	texte imprimé
Auteurs :	Yingjie Li, Auteur ; Changtian Liu, Auteur ; Rongyue Sun, Auteur
Année de publication :	2013
Article en page(s) :	pp. 16042-16048
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Paper industry Solid waste Carbon dioxide
Résumé :	In this work, the sequential SO2 and CO2 capture behavior of lime mud (LM) as a solid waste from the paper industry was investigated in the calcium looping process. In order to minimize the unfavorable effects of impurities such as Na and Cl on CO2 and SO2 capture of LM, the LM was prewashed with distilled water. The prewash treatment improves the cyclic CO2 capture capacity of the LM during multiple carbonation/calcination cycles. The ultimate carbonation conversion of the treated LM is 1.8 and 4.8 times greater than those of the raw LM and the limestone, respectively. The microstructure analysis shows that the surface area and pore volume of the LM are significantly increased after the prewash treatment. With increasing the sulfation temperature from 850 to 950 °C, both the raw LM and the treated one show an increase in the sulfation conversion after the same number of cycles. Interestingly, the effect of the sulfation temperature decreases with increasing the number of cycles. For the raw LM or the treated LM, the sulfation conversion after 50 cycles is higher than that after 15 or 100 cycles. That is related to the change in pore size of the raw LM and the treated LM after multiple cycles. Compared with the raw LM and the limestone, the sulfation conversion of the treated LM is greater after the same number of cycles and at the same reaction time.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26732129

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 16034-16041

Titre :	Adopting the experimental pressure evolution to monitor online the shrinkage in injection molding
Type de document :	texte imprimé
Auteurs :	V. Speranza, Auteur ; U. Vietri, Auteur ; R. Pantani, Auteur
Année de publication :	2013
Article en page(s) :	pp. 16034-16041
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Injection molding Shrinkage Surveillance
Résumé :	In this work, a procedure is reported which is suitable to analyze online the quality of molded parts in terms of shrinkage. The procedure is based on the evaluation of the average solidification pressure, namely the average along the thickness of the pressure at which each layer solidifies, a parameter which is known to correlate well with shrinkage. The calculation of this parameter normally requires the estimation of the solidification history, information which is currently not reachable experimentally. The procedure reported in this work allows adoption of the pressure evolution measured by a piezoelectric pressure transducer to make an estimation of the solidification profile and thus of the average solidification pressure. The procedure is applied to the data of shrinkage measured on an amorphous PS and a semicrystalline iPP in a wide range of processing conditions.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26732128

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 16016–16033

Titre :	Design and control of extractive dividing-wall column for separating methylal–methanol mixture
Type de document :	texte imprimé
Auteurs :	Ming Xia, Auteur ; Baoru Yu, Auteur ; Qiaoyi Wang, Auteur
Année de publication :	2013
Article en page(s) :	pp. 16016–16033
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Control extractive
Résumé :	The design and control of extractive dividing-wall columns (EDWCs) have not yet been investigated, whereas those of dividing-wall columns (DWCs) and conventional extractive distillation columns (CEDCs) have been studied by many researchers. The control of EDWCs is more difficult than that of CEDCs and somewhat different from that of DWCs because of differences in the inner structure and interactions among control loops in EDWCs. In this work, the design and control of an EDWC for methylal/methanol separation are investigated using commercial chemical simulators (Aspen Plus and Aspen Dynamics). The optimum EDWC design based on the total annual cost (TAC) is screened first; then, the interaction between design and control is observed; and finally, two control structures for the EDWC are presented. The first proposed basic control structure featuring four composition controllers and an adjustable vapor split ratio αV can handle all disturbances well with small offsets in product purities, except for a 20% decrease in feed flow rate with a large deviation in methanol product purity. Then, an improved control structure with the QR/F ratio is established. The large deviation is effectively suppressed, and all of the disturbances are well rejected with small offsets in product purities. It is also revealed that the vapor split ratio αV at the bottom edge of dividing wall must be adjusted at least for composition disturbances of key feed components.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3015395

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 16007-16015

Titre :	Applicability of desirability function for control structure design in the frequency domain
Type de document :	texte imprimé
Auteurs :	Maté Haragovics, Auteur ; Hajnalka Kencse, Auteur ; Péter Mizsey, Auteur
Année de publication :	2013
Article en page(s) :	pp. 16007-16015
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Design
Résumé :	In this work, the application of desirability function on controllability indices in the frequency domain is studied and a methodology is presented for its proper application. To design control structures, controllability indices are often used. Different indices represent different controllability attributes of the investigated system or systems; thus, their results might not be in agreement. With the desirability function, it is possible, however, to aggregate the different indices and a final ranking can be obtained, which may substitute time domain studies. Two different fields are examined: control structure variable pairing and selecting a distillation scheme that shows the best controllability features. On one hand, for the variable pairing step of the control structure design, the methodology does not deliver acceptable results, because controllability indices prove to be inaccurate in such cases on which the calculation is based. On the other hand, the methodology delivers similar result for the selection of the right distillation scheme from the controllability point of view to that of the load rejection investigations. This result shows the right area for the applicability of the methodology based on the desirability function.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26732126

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 15997-16006

Titre :	Quantitative analysis of influences of model plant mismatch on control loop behavior
Type de document :	texte imprimé
Auteurs :	Hong Wang, Auteur ; Tore Hagglund, Auteur ; Zhihuan Song, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15997-16006
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Modeling Quantitative analysis
Résumé :	There is normally a mismatch between the current model of the plant and the model that was used for design. This mismatch is normally acceptable when the controller is designed. But if the process dynamics changes, the mismatch may be so large that the control behavior degrades and may be unacceptable. This paper evaluates the influences of model plant mismatch on the control loop behavior quantitatively. A novel method is developed to calculate proposed performance and robustness indices based on the controller and the mismatch. Priorities for maintenance can be made using these indices. Case studies demonstrate the efficacy of the methodology. In addition, the effects of different process dynamics are studied by general analysis.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26732125

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 15986-15996

Titre :	Computational fluid dynamics modeling of corrugated static mixers for turbulent applications
Type de document :	texte imprimé
Auteurs :	Mirella Coroneo, Auteur ; Giuseppina Montante, Auteur ; Alessandro Paglianti, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15986-15996
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Static mixer Modeling Computational fluid dynamics
Résumé :	This work is aimed at investigating the capability of a fully predictive computational fluid dynamics (CFD) approach to catch the main features of the liquid flow in pipelines equipped with corrugated static mixer inserts. The simulations are based on the numerical solution of the Reynolds averaged Navier—Stokes equations on the three-dimensional domain closely representing the static mixer geometry. As a benchmark, literature experiments on a laboratory scale SMV mixer were considered and the simulation results obtained at different locations were compared with relevant velocity and tracer concentration data. The effect of the turbulence modeling, the near-wall treatment, and the numerical approximations on the accuracy of the results is discussed. The results analysis demonstrated that the selected CFD model can be reliably adopted to evaluate the velocity field and the mixing performances of turbulent flows in static mixers for design and optimization purposes. On the other hand, the application of the same model to an industrial scale corrugated plate mixer highlighted the effects of the distributor geometry and of the distance between consecutive elements on the mixing of two miscible liquids.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26732124

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 15974-15985

Titre :	Novel hybrid evolutionary algorithm for dynamic optimization problems and its application in an ethylene oxide hydration reactor
Type de document :	texte imprimé
Auteurs :	Feng Qian, Auteur ; Fan Sun, Auteur ; Wenli Du, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15974-15985
Note générale :	Industrial chemsitry
Langues :	Anglais (eng)
Mots-clés :	Reactor Hydration Optimization Algorithm
Résumé :	A novel hybrid evolutionary algorithm (HEA) that combines the genetic algorithm (GA) and particle swarm optimization (PSO) is proposed to solve the dynamic optimization problems of chemical processes using numerical methods. Based on the characteristics of dynamic optimization problems, the concept of "search region reduction" is integrated into the HEA to improve the convergence rate. A control vector parametrization (CVP) method based on the HEA is also employed to improve the accuracy of the results. The dynamic optimization problem with state variable constraints is an important research area in process system engineering and is difficult to solve. Thus, the present work also proposes a novel method embedding information about infeasible chromosomes into the evaluation function to solve dynamic optimization problems with or without state variable constraints. The results of several case studies demonstrate the feasibility and efficiency of the proposed methods. Finally, the proposed methods are used to solve the temperature distribution problem in an ethylene oxide hydration reactor. Moreover, the proposed algorithm can be regarded as a useful optimization tool, especially when gradient information is unavailable.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26732123

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 15962-15973

Titre :	Poly(vinylidene fluoride) membranes with hyperbranched antifouling and antibacterial polymer brushes
Type de document :	texte imprimé
Auteurs :	Tao Cai, Auteur ; Wen Jing Yang, Auteur ; Koon-Gee Neoh, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15962-15973
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Antibacterial Polymer
Résumé :	Graft copolymers of poly(vinylidene fluoride) (PVDF) with poly[2-(N,N-dimethylamino)ethyl methacrylate] (PDMAEMA) side chains (PVDF-g-PDMAEMA copolymers) were synthesized via activators generated by electron transfer for atom transfer radical polymerization (AGET-ATRP) of 2-(NN-dimethylamino)ethyl methacrylate (DMAEMA) directly from the secondary fluorine atoms on the PVDF backbone. Microporous membranes were fabricated from the PVDF-g-PDMAEMA amphiphilic copolymers by phase inversion in an aqueous medium. After quatemization by propargyl bromide, the resulting PVDF-g-PQDMAEMA membrane and pore surfaces bearing pendant propargyl moieties could be further functionalized via surface-initiated alkyne―azide click reaction of azido-terminated hyperbranched polyglycerols (HPG-N,) to form the PVDF-g-P[QDMAEMA-click-HPG] membranes. The PVDF-g-P[QDMAEMA-click-HPG] membranes exhibit good resistance to protein adsorption and fouling. Alternatively, alkyne—azide click reaction of azido-terminated polyethylenimine (PEI-N3) on the PVDF-g-PQDMAEMA membranes, followed by quaternization with 1-bromohexane, produce the PVDF-g-P[QDMAEMA-click-QPEI] membrane which is effective in reducing bacterial growth and proliferation under continuous-flow conditions.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie302762w

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 15953–15961

Titre :	Critical content of ultrahigh-molecular-weight polyethylene to induce the highest nucleation rate for isotactic polypropylene in blends
Type de document :	texte imprimé
Auteurs :	Wei Shao, Auteur ; Yaqiong Zhang, Auteur ; Zhigang Wang, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15953–15961
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Crystallization kinetics isotactic
Résumé :	The influence of the addition of low amounts of ultrahigh-molecular-weight polyethylene (UHMWPE) on the crystallization kinetics of isotactic polypropylene (iPP) in iPP/UHMWPE blends has been investigated by means of differential scanning calorimetry (DSC) and polarized optical microscopy. During the nonisothermal crystallization process, the primarily formed UHMWPE crystals serve as heterogeneous nucleating agents for iPP nucleation, whereas during the isothermal crystallization process, UHMWPE is in the molten state, iPP nucleation preferentially occurs at the UHMWPE and iPP phase interfaces, and the spherulitic growth rates are not obviously affected. It is particularly interesting to find a critical UHMWPE content (2.5 wt %) in the blends to induce the highest iPP nucleation rate; however, above the critical UHMWPE content, the iPP nucleation rate slows because of aggregation of the UHMWPE component. A delicately designed DSC measurement provides insight into the nucleation mechanism of iPP at the interfaces between the UHMWPE and iPP phase domains. It is proposed that the concentration fluctuations generated from the unstable inhomogeneous phase interfaces in the iPP/UHMWPE blends promote the formation of nuclei, which eventually enhances the nucleation and overall crystallization rates of the iPP component.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie302542x

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 15942-15952

Titre :	Properties and applications of poly(dimethylsiloxane) containing poly(meth)acrylate-based thermoplastic elastomer/clay nanocomposites
Type de document :	texte imprimé
Auteurs :	Ravikumar Muppalla, Auteur ; Suresh K. Jewrajka, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15942-15952
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Nanocomposite
Résumé :	The beneficial effect of covalent attachment of a moderate amount (8―16 wt %) of poly(dimethylsiloxane) (PDMS) into poly(meth)acrylate-based thermoplastic elastomers (TPEs) toward clay nanocomposite (NC) formation with improved mechanical properties, thermal properties, and tunable hydrophobic drug release behavior is reported. XRD and TEM analyses suggest that the covalent attachment of PDMS enhances the NC formation with both exfoliated and intercalated structures. With increasing amount of attached PDMS, the d-spacing of the intercalated clay part increases and the copolymer forms exclusively exfoliated structure at nearly 16 wt % PDMS content. Hence, clay NCs of a wide range of well-defined block copolymers of PDMS and poly(meth)acrylates can conveniently be prepared by this technique. The surface characterizations revealed comparatively more hydrophobic surface of PDMS-containing poly(meth)acrylate-based TPE/clay NCs than the corresponding neat poly(meth)acrylate-based TPE/clay NC. The improved thermal stability, improved mechanical properties, and sustained drug eluting behavior together with preferential surface coverage by biocompatible and biostable PDMS might provide further opportunities for the use of PDMS-containing poly(meth)acrylate-based TPE/clay NCs in possible biomedical applications.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26732120

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 15936-15941

Titre :	Electrochemical behavior of 4-aminophenazone drug at a graphite pencil electrode and its application in real samples
Type de document :	texte imprimé
Auteurs :	Jayant I. Gowda, Auteur ; Sharanappa T. Nandibewoor, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15936-15941
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Electrodes
Résumé :	An analytical method for the determination of 4-aminophenazone using cyclic and differential-pulse voltammetry has been developed. The oxidation process was shown to be irreversible over the pH range 3.0―11.2. The dependence of the current on pH, concentration, and scan rate was investigated to optimize the experimental conditions for the determination of 4-aminophenazone. The number of electrons transferred in the oxidation process was calculated, and a probable oxidation mechanism was proposed. In the range of ( 1.0 X 10―6)―(1.6 X 10―5) M, the current measured by differential-pulse voltammetry as a function of the concentration of 4-aminophenazone with a detection limit of 0.458 × 10―7 M with good selectivity and sensitivity exhibited a good linear relationship. The proposed method was applied to the determination of 4-aminophenazone in a real sample.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26732119

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 15927–15935

Titre :	Isothermal and nonisothermal cold crystallization behaviors of asymmetric poly(l-lactide)/Poly(d-lactide) blends
Type de document :	texte imprimé
Auteurs :	Yi Li, Auteur ; Changyu Han, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15927–15935
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Isothermal crystallization
Résumé :	Isothermal and nonisothermal cold crystallization behaviors of asymmetric poly(l-lactide) (PLLA)/poly(d-lactide) (PDLA) blends at PDLA loadings of 0–20 wt % were investigated in this work. Formation of the stereocomplex in the blends was confirmed by differential scanning calorimetry and wide-angle X-ray diffraction. For both neat PLLA and its blends, the overall isothermal cold crystallization rates increase with increasing crystallization temperature; moreover, the overall isothermal cold crystallization rates of PLLA are faster in the blends than in neat PLLA, indicative of the nucleating agent effect of the stereocomplex formed in the blends. Crystallization mechanism and crystal structure of PLLA remain unchanged despite the PDLA loading. For the nonisothermal cold crystallization, the crystallization process of PLLA is accelerated by increasing both heating rate and the PDLA loading up to 10 wt %. The Ozawa equation failed to fit the crystallization process, while the Tobin equation could describe it well in the relative degree of crystallization range of 0–75%.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie302447e

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 15918–15926

Titre :	Enhanced properties of the incorporation of a novel reactive phosphorus- and sulfur-containing flame-retardant monomer into unsaturated polyester resin
Type de document :	texte imprimé
Auteurs :	Kang Dai, Auteur ; Lei Song, Auteur ; Richard K. K. Yuen, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15918–15926
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Reactive phosphorus
Résumé :	A novel reactive phosphorus- and sulfur-containing flame-retardant monomer [di(allyloxybisphenol sulfone) phenoxy phosphonate, DASPP] was successfully synthesized and well characterized. Various amounts of DASPP were incorporated into the unsaturated polyester by radical bulk polymerization. The thermal properties and flammability of the flame-retardant unsaturated polyester resin (FR-UPR) samples were investigated by differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), limiting oxygen index (LOI) measurements, and cone calorimetry. The results showed that the introduction of DASPP into unsaturated polyester resin (UPR) can substantially improve its fire resistance and high-temperature stability. Interestingly, a linear increase in the glass transition temperature (Tg) with increasing incorporated DASPP content was observed by DSC. Scanning electron microscopy (SEM) and Raman spectroscopy studies revealed that DASPP can effectively improve the microstructure of UPR char residue and increase its graphitization degree, which can enhance UPR’s thermo-oxidative stability and char yield in high-temperature regions. Furthermore, real-time Fourier transform infrared (RTIR) spectroscopy was employed to study the thermo-oxidative degradation reactions of different UPR samples, providing insight into the combustion mechanism. In addition, results from tensile testing demonstrated the improved mechanical properties for the samples containing DASPP.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie302106w

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 15912–15917

Titre :	Experimental investigation of the interaction of dimethyl sulfide/ethyl mercaptan with nano-manganese dioxide
Type de document :	texte imprimé
Auteurs :	Jie He, Auteur ; Xiaotian Liu, Auteur ; Lin Li, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15912–15917
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Nano manganese dioxide
Résumé :	Nano-MnO2 was prepared by a sol–gel technology, and the structure was characterized by means of powder X-ray diffraction (XRD). The interaction of dimethyl sulfide (DMS) or ethyl mercaptan (EM) with the as-prepared MnO2 was investigated at ambient temperature with Fourier transform infrared (FT-IR) spectroscopy, X-ray photoelectron spectroscopy (XPS), and laser Raman spectroscopy (LRS). The results showed that DMS and EM undergo different interactions with the surface of MnO2. The interaction of DMS and MnO2 bring about carbon–sulfur bond cleavage and the oxidation of C. However, there might be hydrogen bonding between EM and MnO2 in addition to chemical bonding, which results in a weaker S–H bond in the EM molecule, so that EM is easily oxidized to sulfonates and sulfates. Tentative interaction mechanisms for DMS and EM on MnO2 are suggested.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie302097x

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 15901–15911

Titre :	Modeling reaction and diffusion in a spherical catalyst pellet using multicomponent flux models
Type de document :	texte imprimé
Auteurs :	Jin Yang Lim, Auteur ; John S. Dennis, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15901–15911
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Catalyst Multicomponent
Résumé :	This work presents the derivation and evaluation of a nonisothermal, steady-state model for a spherical pellet of catalyst, where the intraparticle diffusion is modeled by the Cylindrical Pore Interpolation Model (CPIM), a multicomponent flux model based on the Stefan-Maxwell equations, modified by a momentum balance. Since many reactions involve more than two chemical species and most industrial catalysts operate under diffusion-limited regimes, understanding intraparticle, multicomponent diffusion is crucial for the accurate modeling of reaction and diffusion within a catalyst pellet. The model was applied to the methanation reaction, where its industrial importance and high exothermicity makes it an ideal candidate as a concrete example. The profiles within the catalyst of composition, pressure, temperature, and rate of reaction were generated for various conditions. Several key dimensionless groups were identified in order to study the system over a large range of conditions and identify the important parameters. The predictions from the CPIM and the Dusty Gas Model (DGM) were compared. It was found that under most circumstances, only minor differences were observed between the predictions of the CPIM and the DGM. However, appreciable discrepancies were found when catalyst pellets, which had low thermal conductivities and contained pores of size such that values of both Knudsen and binary diffusivity were comparable, were reacted at low pressure. In summary, the work shows that the CPIM is well-suited to modeling multicomponent diffusion and reaction in pseudohomogenous catalyst pellets because (i) the assumptions used in the derivation are reasonable and explicit, (ii) an interpolation procedure allows diffusion to be modeled for the range from Knudsen diffusion through to continuum flow, and (iii) the equations can be presented in a compact form suitable for numerical solution.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie302528u

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 15895-15900 [

Titre :	On the suitability of a bacterial consortium to implement a continuous PAHs biodegradation process in a stirred tank bioreactor
Type de document :	texte imprimé
Auteurs :	F. Moscoso, Auteur ; I. Teijiz, Auteur ; M. A. Sanroman, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15895-15900 [
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Bioreactor Stirred vessel Biodegradation
Résumé :	A new microbial consortium made up with two bacterial strains phylogenetically identified as Bacillus pumilus and Staphylococcus warneri was obtained from lab soils polluted with polycyclic aromatic hydrocarbons (PAHs) and heavy metals. Its PAH degradation potential has been demonstrated recently by culturing the consortium in the presence of phenanthrene (PHE), pyrene (PYR), and benzoanthracene (BaA). The efficiency of the proposed degradation process was evaluated at flask and bioreactor scale, operating in fed-batch mode, as a prior step to achieve an effective biodegradation process in continuous mode. An acclimation of the consortium to the selected PAHs has been evidenced in fed-batch cultures after 6 batches (90% of degradation in less than one day). The effect of the dilution rate was analyzed in a continuous stirred tank bioreactor operating for 2 months, observing that some of the dilution rates employed allowed achieving degradation rates higher than 90% per day for all the contaminants.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26732114

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 15884-15894

Titre :	Selective oxidation of glycerol catalyzed by gold supported on multiwalled carbon nanotubes with different surface chemistries
Type de document :	texte imprimé
Auteurs :	Elodie G. Rodrigues, Auteur ; Juan J. Delgado, Auteur ; X. Chen, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15884-15894
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Catalytic reaction Oxidation
Résumé :	Carbon nanotubes with different levels of oxygenated groups on the surface were used as supports for gold nanoparticles and tested in glycerol oxidation. It was concluded that the support has an active role in the catalytic performance. Gold is highly active and selective when the support has only a limited amount of oxygenated groups on the surface. These groups, mainly those with acid character, are unfavorable for the catalytic activity, and their presence promotes the formation of overoxidation products, such as glycolic acid. Accordingly, turnover frequency values vary between 30 and 1870 h―1 depending on the support used. Oxygen-free carbon nanotubes lead to selectivities toward glyceric acid as high as 60%, whereas only 40% was obtained with oxygen-rich supports.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26732113

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp 15872–15883

Titre :	Kinetics of CO2/coal gasification in molten blast furnace slag
Type de document :	texte imprimé
Auteurs :	Li Peng, Auteur ; Qingbo Yu, Auteur ; Qin Qin, Auteur
Année de publication :	2013
Article en page(s) :	pp 15872–15883
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Gasification Kinetics
Résumé :	The coal/CO2 gasification reactions in molten BF (blast furnace) slag were studied kinetically by temperature-programmed thermogravimetry using a thermal analyzer. The effect of heating rates and molten BF slag on coal gasification were studied, and the activation energies, frequency factors, and most possibility mechanism functions were calculated. The results show that the order of reactivity sequence at these temperatures was DT (Datong) coal > FX (Fuxin) coal > coke. With the increase in heating rate, the carbon conversion, and the peak value of reaction rate increased at the same reaction time, the carbon conversion curve shifts to a higher temperature and the reaction rate curve shifts rightward systematically, both of the time required for the carbon conversion to reach nearly unity and the time necessary for reaction rate to reach its maximum decreased. The carbon conversion and reaction rates were sensitive to BF slag; at the same time, the carbon conversion and reaction rates of coal gasification with slag are higher than those without slag. The time required for the carbon conversion to reach nearly unity and the time required for the reaction rate to reach maximum with slag are both shorter than that without slag. In the presence of BF slag, the carbon conversion curve shifts to lower temperature, the peak value of reaction rate is higher than that without slag, and the reaction rate curve also shifts to lower temperature. The molten BF slag acts as a good catalyst to coal gasification. Without molten BF slag, the mechanism functions of coke and FX coal are a C1 model (phase boundary reaction (n = 2) model), while the mechanism function of DT coal is a C2 model (phase boundary reaction (n = 3/2) model). However, with molten BF slag, the mechanism function of coke is a D5 model (3-D diffusion (anti-Jander) model), the mechanism function of DT coal is a D4 model (3-D diffusion model), and the mechanism function of FX coal is a C2 model (phase boundary reaction (n = 3/2) model). The activation energies and frequency factors decrease as heating rates increase. The kinetic compensation effect of coal/CO2 gasification in molten BF slag exists.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301678s

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 15864-15871

Titre :	Direct hydration of β-caryophyllene
Type de document :	texte imprimé
Auteurs :	Gaodong Yang, Auteur ; Pingkeng Wu, Auteur ; Zheng Zhou, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15864-15871
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Hydration
Résumé :	This study of β-caryophyllene hydration to produce β-caryophyllene alcohol was carried out catalyzed by strong acidic cation exchange resin NKC-9. The effects of different parameters such as agitation speed, catalyst type, catalyst loading, mass ratio of the reactants, temperature, and reaction time on the conversion of β-caryophyflene and yield of β-caryophyllene alcohol in a stirred-tank reactor have been investigated to obtain the optimal conditions. Under the optimal conditions (catalyst loading 20%(w/w), nβ-caryophyllene/nwater 1/1, reaction temperature 363.15 K, reaction time 30―40 min), the experiment was then carried out in a pilot-scale stirred tank reactor and in a novel pilot-scale jet reactor respectively to achieve excellent performance. The β-caryophyllene alcohol has been purified by rectifying column and recrystallized. A pseudohomogeneous (PH) model was used to correlate the kinetic data in the temperature range from 333.15 to 363.15 K. The estimated kinetic parameters make the calculated results in excellent agreement with the experimental results.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26732111

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp 15855–15863

Titre :	Kinetic modeling and isotopic investigation of isobutanol fermentation by two engineered escherichia coli strains
Type de document :	texte imprimé
Auteurs :	Yi Xiao, Auteur ; Xueyang Feng, Auteur ; Arul M. Varman, Auteur
Année de publication :	2013
Article en page(s) :	pp 15855–15863
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Kinetic Isotopic
Résumé :	We constructed an Escherichia coli BL21 strain with the Ehrlich pathway (the low-performance strain for isobutanol production). We also obtained a high isobutanol-producing E. coli strain JCL260 from the James Liao group (University of California). To compare the fermentation performances of the two engineered strains, we employed a general Monod-based model coupled with mixed-growth-associated isobutanol formation kinetics to simulate glucose consumption, biomass growth, and product secretion/loss under different cultivation conditions. On the basis of both kinetic data and additional 13C-isotopic investigation, we found that the low-performance strain demonstrated robust biomass growth in the minimal growth medium (20 g/L glucose), achieving isobutanol production (up to 0.95 g/L). It utilized significant amounts of yeast extract to synthesize isobutanol when it grew in the rich medium. The rich medium also enhanced waste product secretion, and thus reduced the glucose-based isobutanol yield. In contrast, JCL260 had poor biomass growth in the minimal medium due to an inflated Monod constant (KS), while the rich medium greatly promoted both biomass growth and isobutanol productivity (60% of the theoretical isobutanol yield). With the optimized keto-acid pathway, JCL260 synthesized isobutanol mostly from glucose even in the presence of sufficient yeast extract. This study not only provided a kinetic model for scaled-up isobutanol fermentation but also offered metabolic insights into the performance trade-off between the two engineered E. coli strains.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202936t

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 15839-15854

Titre :	Flow, transport, and reaction interactions in shaped cylindrical particles for steam methane reforming
Type de document :	texte imprimé
Auteurs :	Anthony G. Dixon, Auteur ; Justin Boudreau, Auteur ; Anne Rocheleau, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15839-15854
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Reforming Water vapor Transport process
Résumé :	Complex interactions between steam methane reforming reaction rates, conduction, and diffusion inside cylindrical catalyst particles with holes, and the external flow and temperature fields near the heated tube wall were shown in detail using computational fluid dynamics and compared to prior work on full cylinders. This work highlights the differences caused by the particle features. Simulations were done under industrial tube inlet conditions at a constant pressure drop for one-, three-, four-, and six-hole cylinders. Heat and mass fluxes were within 10% for all particle surfaces; the holes provided the reactant good access to the particles. The six-hole catalyst particles offered the best temperature distribution and reaction rate. However, the four-hole particles gave a higher mass flow rate and lower tube-wall temperature for a set pressure drop.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26732109

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 15832-15838

Titre :	UV-curable epoxy silicone with a high refractive index and self-photosensitizing effect
Type de document :	texte imprimé
Auteurs :	Wang, Tao, Auteur ; Hui Ye, Auteur ; Xianshun Zhang, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15832-15838
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Ultraviolet radiation
Résumé :	The present work addresses a demand for cationically UV-curable optically transparent monomers and oligomers with high photopolymerization activity and high refractive indexes (RIs). Two novel kinds of epoxy silicones, carbazole-bound epoxy tetramethylcyclotetrasiloxane (Ep-Cz-Si) and carbazole-bound epoxy methylhydrogen silicone oil (Ep-Cz-SiO), were synthesized from 1,3,5,7-tetramethylcyclotetrasiloxane (D4H) and methylhydrogen silicone oil (HHSiO), respectively. Their structures were confirmed by proton nuclear magnetic resonance (1H NMR) and Fourier transform infrared (FT-IR) spectroscopy. Ep-Cz-Si and Ep-Cz-SiO show strong self-photosensitizing effects in photopolymerization and can be photoinitiated directly by a common onium salt photoinitiator under a high-pressure mercury lamp. The RIs of Ep-Cz-Si and Ep-Cz-SiO improve with increasing carbazole content. The photocured networks from Ep-Cz-Si and Ep-Cz-SiO show good thermal stabilities.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26732108

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 15821–15831

Titre :	Synthesis and characterization of Co–Mn nanoparticles immobilized on a modified bentonite and its application for oxidation of p-xylene to terephthalic acid
Type de document :	texte imprimé
Auteurs :	M. Ghiaci, Auteur ; M. Mostajeran, Auteur ; A. Gil, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15821–15831
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Nanoparticles Oxidation
Résumé :	This study describes the synthesis and characterization of a new supported bentonite catalyst prepared by the two-step modification of Na-bentonite. In the first step, Na-bentonite is modified with cetyl pyridinium bromide (CPB) to give a monolayer bentonite (CP-bentonite) in which surfactant ions are adsorbed by cation exchange with the counterions of bentonite. This gives a disordered liquid-like monolayer arrangement of alkyl chains within the gallery. This monolayer bentonite is then treated with the second generation of an amidoamine cascade known as 3,3′-(dodecylazanediyl)bis(N-(2-(2,3,3′-(dodecylazanediyl)bis(N-(2-(2-aminoethyl(2-hydroxybenzenimine))ethyl)propanamide) (DAEP), which has a long aliphatic tail (C12) and a hydrophilic head, to form a modified bilayer bentonite (Ben-DAEP-modified). The solid/liquid interface layer of this architecturally designed bentonite (Ben-DAEP-modified) was used as a pincer-type ligand for the synthesis of a new host–guest catalyst by immobilization of Co, Mn, or Co/Mn on it. The structure, specific surface area, and porosity of bentonite are significantly altered by the incorporation of nanoparticles. The resulting solid catalysts were characterized by UV–vis, Fourier transform infrared (FT-IR), inductively coupled plasma (ICP), scanning electron microscopy (SEM), N2 adsorption, and transmission electron microscopy (TEM) techniques. The oxidation of p-xylene produces five products: 4-methyl benzaldehyde, 4-methyl benzoic acid, 1,4-benzene dialdehyde, 4-carboxybenzaldehyde, and 1,4-benzenedioic acid. The reaction conditions for oxidation of p-xylene were optimized by varying the temperature, pressure, amount of catalyst, time, and catalyst-to-oxidant ratio. The optimum conditions for oxidation of p-xylene to 1,4-benzenedioic acid (terephthalic acid) were 0.15 g of Ben-DAEP-modified-Co/Mn (Co/Mn with a ratio of 10/1), 190 °C, 3% of Br– as promoter, 17 atm, and 3 h.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3021939

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 15811-15820

Titre :	Dielectric properties of free radical initiators—investigation of thermal decomposition products
Type de document :	texte imprimé
Auteurs :	Jaouad El harfi, Auteur ; Sam W. kingman, Auteur ; Georgios Dimitrakis, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15811-15820
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Thermal decomposition Free radical Dielectric properties
Résumé :	Studies into the phenomena that explain the dielectric properties of azo initiators (AMBN and V70) at high temperatures are reported in this paper. Previous studies have successfully related the variation in dielectric properties of these species below 110 °C to either phase changes or the thermal production of free radicals. In the latter case the marked increase in their response was attributed to the free radicals having more prominent dipoles than their initiator precursors. This study reports the results of experiments designed to explain their observed dielectric characteristics within the temperature range of 110―150 °C. At these elevated temperatures, the decomposition half-life of the initiators studied should be of the order of few seconds. However, in both this and the previous reports, the dielectric response is found to remain at a significant level for several hours. The two prime explanations for the unexpected duration of the increased dielectric properties are (i) the presence of microwave induced protected radicals or (ii) the dielectric properties of the initiator decomposition products. The observations made in this study were subsequently used to define that the latter of these is the key to the observed phenomenon.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26732106

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 49 (Décembre 2012) . - pp. 15801–15810

Titre :	Solid-state polymerization of semiaromatic copolyamides of nylon-4,T and Nylon-4,6 : Composition ratio effect and thermal properties
Type de document :	texte imprimé
Auteurs :	Young Jun Kim, Auteur ; Kurnia Endah Yohana, Auteur ; Hong-shik Lee, Auteur
Année de publication :	2013
Article en page(s) :	pp. 15801–15810
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Thermal properties Polymerization
Résumé :	Solid-state polymerization (SSP) of semiaromatic copolyamides composed of nylon-4,T and nylon-4,6 in different molar ratios were investigated using a mixture of nitrogen and steam as the sweep fluid at reaction temperatures in the range of 220–260 °C. Prepolymers having different nylon-4,T contents (28.2, 37.9, and 47.8 mol %) were synthesized by melt polyamidation with stoichiometric ratios of diamine and diacid. The SSP conditions were carefully chosen to eliminate the influences of both internal and external diffusion of the reaction byproducts. Under these conditions, a high-molecular-weight semiaromatic copolyamide with an intrinsic viscosity of 2.469 dL/g was obtained upon SSP at 260 °C for 48 h. As the nylon-4,T content increased, the SSP rate decreased owing to the inherently low reactivity of the aromatic diacid and inhibition of chain-end mobility. The glass transition, melting, and decomposition temperatures of the polymers synthesized from the higher-nylon-4,T-content prepolymer were always higher than those of the polymers synthesized from the lower-nylon-4,T-content prepolymer.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26732105

Industrial & engineering chemistry research / Paul, Donald R. . Vol. 51 N° 49

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