Catalogue en ligne Bibliothèque Ecole Nationale Polytechnique d'Alger

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13323-13328

Titre :	A comparative study of crystallization, melting behavior, and morphology of biodegradable poly(ethylene adipate) and poly(ethylene adipate-co-5 mol % ethylene succinate)
Type de document :	texte imprimé
Auteurs :	Huina Wu, Auteur ; Zhaobin Qiu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13323-13328
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Morphology Melting Crystallization Comparative study
Résumé :	A comparative study was performed in this work to investigate the crystal structure, thermal behavior, melting behavior, overall isothermal melt crystallization kinetics, and spherulitic morphology of biodegradable neat poly(ethylene adipate) (PEA) and its novel copolyester poly(ethylene adipate-co-5 mol % ethylene succinate) P(EA-co-5 mol % ES). Both neat PEA and P(EA-co-5 mol % ES) show the same crystal structure. Relative to neat PEA, the incorporation of a small amount of ethylene succinate (ES) composition exerts almost no influence on the glass-transition temperature, reduces the melting point temperature and equilibrium melting point temperature slightly, but suppresses the nonisothermal melt and cold crystallization significantly of P(EA-co-5 mol % ES). Depending on crystallization temperature, both neat PEA and P(EA-co-5 mol % ES) show double melting endotherms or one melting endotherm, which can be well explained by the melting, recrystallization, and remelting mechanism. The overall isothermal melt crystallization kinetics was studied for neat PEA and P(EA-co-5 mol % ES) and analyzed by the Avrami equation. With increasing crystallization temperature, the crystallization rates are reduced for both neat PEA and P(EA-co-5 mol % ES); moreover, the crystallization rate is faster in neat PEA than in P(EA-co-5 mol % ES) at a given crystallization temperature. The crystallization mechanism remains unchanged despite crystallization temperature and the incorporation of ES composition. Depending on crystallization temperature, neat PEA and P(EA-co-5 mol % ES) may form ring-banded or ringless spherulites.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26451482

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13319-13322

Titre :	99Mo separation from high-concentration irradiated uranium nitrate and uranium sulfate solutions
Type de document :	texte imprimé
Auteurs :	Gregory E. Dale, Auteur ; Dale A. Dalmas, Auteur ; Michael J. Gallegos, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13319-13322
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Uranium Sulfate
Résumé :	We report separation data indicating that 99Mo can be separated from a vast excess of either uranyl sulfate or uranyl nitrate in irradiated dilute acid solutions. These results suggest that, if medical isotope 99Mo is produced during fission of high concentrations of low enriched uranium sulfate solution fuel, it is feasible to both recover >90% of the 99Mo for further purification and the uranium for recycle.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3008743

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13300-13318

Titre :	Analysis of entropy generation due to natural convection in tilted square cavities
Type de document :	texte imprimé
Auteurs :	Abhishek Kumar Singh, Auteur ; S. Roy, Auteur ; Tanmay Basak, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13300-13318
Note générale :	Industrial chemsitry
Langues :	Anglais (eng)
Mots-clés :	Thermodynamic properties Natural convection Entropy
Résumé :	In this article, the numerical investigation of entropy generation due to heat transfer irreversibility and fluid friction irreversibility during natural convection within tilted square cavity with hot wall AB, cold side walls (DA and BC), and top insulated wall (CD) has been performed. The numerical simulation has been carried out for various fluids of industrial importance (Pr = 0.015, 0.7, and 1000), Rayleigh numbers (103 ≤ Ra ≤ 105), and different inclination angles (ϕ =15°, 45°, and 75°). The results are presented in terms of isotherms (8), streamlines (ψ), entropy generation maps due to heat transfer (Sθ), and fluid friction (Sψ). The total entropy generation (Stotal), average Bejan number (Beav), and average heat transfer rate (NuAB) are plotted for Rayleigh number 103 ≤ Ra ≤ 105. The maximum values of Sθ occur near the comer regions of wall AB due to a junction of hot and cold walls. On the other hand, maximum values of Sψ are found near the walls of the cavity due to friction between the circulation cells and walls of the cavity. It is found that minimum entropy generation occurs for ϕ ≥ 45° at convection dominant mode (Ra = 105) for lower Pr (Pr = 0.015 and 0.7). The inclined cavity with ϕ = 45° may be an alternative optimal inclination angle in optimal thermal processing of high Pr (Pr = 1000).
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26451480

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13282-13299

Titre :	Experimental and quantum chemical studies of some bis(trifluoromethyl-sulfonyl) imide imidazolium-based ionic liquids as corrosion inhibitors for mild steel in hydrochloric acid solution
Type de document :	texte imprimé
Auteurs :	Lutendo C. Murulana, Auteur ; Ashish K. Singh, Auteur ; Sudhish K. Shukla, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13282-13299
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Mild steel Corrosion inhibitor Ionic liquid
Résumé :	The corrosion inhibition of mild steel in 1.0 M HCl solution by some selected imidazolium-based ionic liquids, namely 1-propyl-3-methylimidazolium bis(trifluoromethyl-sulfonyl) imide ((PMIM][NTf2), 1-butyl-3-methylimidazolium bis(trifluoromethyl-sulfonyl) imide ([BMIM][NTf2), 1-hexyl-3-methylimidazolium bis(trifluoromethyl-sulfonyl) imide ([HMIM][NTf2]), and 1-propyl-2,3-methylimidazolium bis(trifluoromethyl-sulfonyl) imide ([PDMIM][NTf2]) was investigated using weight loss, electrochemical measurements, and quantum chemical calculations. All ionic liquids showed appreciable inhibition efficiency. Among the ionic liquids studied, [PDMIM][NTf2] exhibited the best inhibition efficiency. The results from the weight loss, electrochemical measurements and quantum chemical calculations show that the order of inhibition efficiency by the ionic liquids follow the order [PDMIM][NTf2] > [HMIM][NTf2] > [BMIM][NTf2] > [PMIM][NTf2]. At 303 K, polarization measurements indicated that all the studied compounds are mixed-type inhibitors. The adsorption of the studied ionic liquids obeyed the langmuir adsorption isotherm. There is good correlation between a composite index of quantum chemical parameters and experimentally determined inhibition efficiency of the inhibitors. The quantitative structure activity relationship (QSAR) approach has provided a good indication that an optimum of at least two quantum chemical parameters is required for a good correlation with the experimentally determined inhibition efficiency of the ionic liquids.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26451479

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13274-13281

Titre :	Predicting the net heat of combustion of organosilicon compounds from molecular structures
Type de document :	texte imprimé
Auteurs :	Yong Pan, Auteur ; Juncheng Jiang, Auteur ; Yinyan Zhang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13274-13281
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Molecular structure Combustion Prediction
Résumé :	The net heat of combustion is one of the most important properties of flammable substances that can be used to estimate the potential fire hazards of chemicals once they ignite and bum. This study proposed a quantitative structure-property relationship model to predict the net heat of combustion of 308 organosilicon compounds from only the knowledge of their molecular structures. Various kinds of molecular descriptors, such as topological, charge, and geometric descriptors, were calculated to represent the molecular structures of organosilicon compounds. The genetic algorithm combined with multiple linear regression is employed to select optimal subset of descriptors that have significant contribution to the overall net heat of combustion property. The best resulted model is a three-variable multilinear model, with the root-mean-square error and average absolute error for the external test set being 176.8 and 111.2 kJ/mol, respectively. Model validation was also performed to check the stability and predictive capability of the presented model. The results showed that the presented model is a valid and predictive model. This study can provide a new way for predicting the net heat of combustion of organosilicon compounds for engineering.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26451478

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13268-13273

Titre :	Kinetic parameters estimation in the polymerase chain reaction process using the genetic algorithm
Type de document :	texte imprimé
Auteurs :	Lanting Li, Auteur ; Chao Wang, Auteur ; Bo Song, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13268-13273
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Genetic algorithm Polymerase chain reaction Parameter estimationKinetic parameter
Résumé :	Analyzing the polymerase chain reaction (PCR) process by mathematical modelling is of importance in terms of uncovering the dynamic mechanism of PCR and predicting DNA amplification performance. Construction of an ideal PCR model, however, requires sufficient and accurate kinetic parameters, which cannot be easily obtained directly from experimental data. In this work, a genetic algorithm-based approach was introduced for optimizing kinetic parameters of PCR such as the rate constant of polymerase catalyst reaction. The fitted model agrees well with experimental data and predicts the DNA amplification yields as a function of cycle number. The kinetic parameters are not dependent on initial concentrations or the fragment types of DNA amplification. The model also allows us to predict the threshold cycle in real-time PCR, which is helpful for estimating the initial amount of DNA template and determining the optimal PCR reaction conditions.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26451477

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13259–13267

Titre :	Sustainable electrochemical regeneration of copper-loaded ion exchange media
Type de document :	texte imprimé
Auteurs :	David K. Hubler, Auteur ; James C. Baygents, Auteur ; James Farrell, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13259–13267
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Electrochemical regeneration
Résumé :	An electrochemical method for regenerating copper-loaded ion exchange media was investigated. The method involved circulating a moderate pH regenerant solution between a bed of ion exchange media and an electrochemical cell. The electrochemical regeneration process eliminates more than 99% of the acid and base use associated with conventional regeneration, consumes no water, produces metallic copper, and eliminates the production of a copper-laden sludge. Experiments were performed measuring copper plating rates as a function of the aqueous copper concentration, cell current, and flow rate. Experiments were also performed to determine the equilibrium partitioning of copper ions between the solution and the ion exchange media under loading and regeneration conditions. A mathematical model was developed and calibrated using experimental data, to provide guidance for the design of electrochemical ion exchange regeneration systems. The model incorporates the plating kinetics, the stripping of copper from the resin, and the equilibrium isotherm and predicts aqueous and adsorbed copper concentrations during the regeneration process. The model indicates that, in 789 min, 90% of copper can be removed from a resin loaded with 50 mg(Cu)/g(resin). An economic analysis indicates that energy costs for plating are less than 1% of chemical costs for conventional ion exchange regeneration.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301443u

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13251-13258

Titre :	Application of the maxwell–stefan approach to acrylonitrile adsorption and desorption in a macroporous polymer
Type de document :	texte imprimé
Auteurs :	C. Wegmann, Auteur ; E. Suárez García, Auteur ; P. J. A. M. Kerkhof, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13251-13258
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Macroporosity Desorption Adsorption
Résumé :	This article reports the application of the Maxwell―Stefan approach for multicomponent liquid-phase diffusion in a macroporous polymer. The adsorption of acrylonitrile onto Dowex Optipore L-493 from water and its desorption from the sorbent in different water/acetone mixtures was modeled. The intraparticle diffusion is treated as diffusion in a nonideal bulk fluid since the pores of the sorbent are large and the molecules-pore wall interactions can therefore be neglected. The results of the simulations are in good agreement with the experimental data. The Maxwell―Stefan intraparticle diffusion coefficients are in the same range as the free liquid diffusion coefficients according to Fick. The calculation of the thermodynamic factors shows that, whereas for low acrylonitrile mole fractions in water, Fick's diffusion can give good results, the nonideality of the system has to be taken into account for higher acrylonitrile concentrations.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26451475

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13245–13250

Titre :	Extraction behavior of fission products with Tri-n-butyl phosphate by countercurrent multistage extraction in a uranium, plutonium, and neptunium Co-recovery system
Type de document :	texte imprimé
Auteurs :	Masaumi Nakahara, Auteur ; Yasuo Nakajima, Auteur ; Tsutomu Koizumi, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13245–13250
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Solvent extraction process
Résumé :	In an attempt to develop a simplified solvent extraction process for U, Pu, and Np co-recovery, three countercurrent experiments were carried out to evaluate the effect of the scrubbing solution on the decontamination of fission products (FPs) using a dissolver solution derived from the irradiated core fuel of fast reactor “JOYO”. In all the runs, Np was co-extracted with U and Pu using tri-n-butyl phosphate (TBP) at the extraction section by using high HNO3 concentration feed solution. Of all the FPs, the decontamination behavior of Zr and Tc varied with the HNO3 concentration of the scrubbing solutions. Zirconium and Tc were not decontaminated with a single scrub flow sheet, which caused the accumulation of Zr at the co-decontamination section. The decontamination factors (DFs) of Zr and Tc were 2.62 × 101 and 1.07 × 100 with flow sheet using 9 and 1 mol/dm3 HNO3 scrubbing solutions, respectively. On the other hand, their DFs increased to >7.68 × 101 and >7.52 × 100 with 2 and 10 mol/dm3 HNO3 scrubbing solutions, respectively. The experimental results indicate that it is necessary to first remove Zr from the loaded solvent with a low HNO3 concentration scrubbing solution and then decontaminate Tc using a high HNO3 concentration solution. Other FPs, such as Cs, were effectively decontaminated with DFs in the range of 105.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3011287

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13238–13244

Titre :	Degradation of CYANEX 301 in contact with nitric acid media
Type de document :	texte imprimé
Auteurs :	Philippe Marc, Auteur ; Radu Custelcean, Auteur ; Gary S. Groenewold, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13238–13244
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Nitric acid
Résumé :	The nature of the degradation product obtained upon contacting CYANEX 301 (bis(2,4,4-trimethylpentyl)dithiophosphinic acid) with nitric acid has been elucidated and found to be a disulfide derivative. The first step to the degradation of CYANEX 301 in toluene has been studied using 31P{1H} NMR after being contacted with nitric acid media. The spectrum of the degradation product exhibits a complex multiplet around δP = 80 ppm. A succession of purifications of CYANEX 301 has resulted in single crystals of the acidic form and the corresponding ammonium salt. Unlike the original CYANEX 301, which consists of a complex diastereomeric mixture displaying all possible combinations of chiral orientations at the 2-methyl positions, the purified crystals were shown by single-crystal X-ray diffraction to be racemates, containing 50:50 mixtures of the [R;R] and [S;S] diastereomers. The comparison between the 31P {1H} NMR spectra of the degradation products resulting from the diastereomerically pure CYANEX 301 and the original diastereomeric mixture has elucidated the influence of the isomeric composition on the multiplicity of the 31P {1H} NMR peak. These NMR data indicate the initial degradation leads to a disulfide-bridged condensation product displaying multiple resonances due to phosphorus–phosphorus coupling, which is caused by the inequivalence of the two P atoms as a result of their different chirality. A total of nine different NMR resonances, six of which display phosphorus–phosphorus coupling, could be assigned, and the identity of the peaks corresponding to phosphorus atoms coupled to each other was confirmed by 31P {1H} homodecoupled NMR analysis.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300757r

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13227-13237

Titre :	Multiway gaussian mixture model based adaptive kernel partial least squares regression method for soft sensor estimation and reliable quality prediction of nonlinear multiphase batch processes
Type de document :	texte imprimé
Auteurs :	Jie Yu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13227-13237
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Software sensor Batchwise Batchwise Prediction Partial least squares Modeling
Résumé :	The predictive model based soft sensor technique has become increasingly important to provide reliable online measurements, facilitate advanced process control and optimization, and improve product quality in process industries. The conventional soft sensors are normally single-model based and thus may not be appropriate for processes with shifting operating phases or conditions and the underlying changing dynamics. In this study, a multiway Gaussian mixture model (MGMM) based adaptive kernel partial least-squares (AKPLS) method is proposed to handle online quality prediction of batch or semibatch processes with multiple operating phases. The three-dimensional measurement data are first preprocessed and unfolded into two-dimensional matrix. Then, the multiway Gaussian mixture model is estimated in order to identify and isolate different operating phases. Further, the process and quality measurements are separated into multiple segments corresponding to those identified phases, and the various localized kernel PLS models are built in the high-dimensional nonlinear feature space to characterize the shifting dynamics across different operating phases. Using Bayesian inference strategy, each process measurement sample of a new batch is classified into a particular phase with the maximal posterior probability, and thus, the local kernel PLS model representing the identical phase can be adaptively chosen for online quality variable prediction. The presented soft sensor modeling method is applied to a simulated multiphase penicillin fermentation process, and the computational results demonstrate that the proposed MGMM-AKPLS approach is superior to the conventional kernel PLS model in terms of prediction accuracy and model reliability.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26451472

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13219–13226

Titre :	Time-Dependent Implementation of Argonne’s Model for Universal Solvent Extraction
Type de document :	texte imprimé
Auteurs :	Kurt Frey, Auteur ; John F. Krebs, Auteur ; Candido Pereira, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13219–13226
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Solvent extraction processes
Résumé :	Argonne’s Model for Universal Solvent Extraction (AMUSE) simulates multistage counter-current solvent extraction processes for species of interest to spent nuclear fuel reprocessing; it is a model of a liquid–liquid extraction unit operation. This work extends the model from its original steady-state implementation to include a time-dependent description of all species of interest. Major components of this extension include a differential mass transfer term, a description of interstage flow rates, and a reaction network for plutonium reduction. The mass transfer term has been formulated using a lumped efficiency term in place of a mass transfer coefficient; the plutonium reduction reactions have been formulated to ensure consistency at all operating conditions. Several nonequilibrium behaviors during simulations have been identified, which allows for improved safety monitoring during process start up and disturbance response.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301421d

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13205–13218

Titre :	Kernel-Based Spatiotemporal Multimodeling for Nonlinear Distributed Parameter Industrial Processes
Type de document :	texte imprimé
Auteurs :	Chenkun Qi, Auteur ; Han-Xiong, Li, Auteur ; Shaoyuan Li, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13205–13218
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Industrial processes
Résumé :	Many industrial processes are nonlinear distributed parameter systems (DPS) that have significant spatiotemporal dynamics. Due to different production and working conditions, they often need to work at a large operating range with multiple working points. However, direct global modeling and persistently exciting experiment in a large working region are very costly in many cases. The complex spatiotemporal coupling and infinite-dimensional nature make the problem more difficult. In this study, a kernel-based spatiotemporal multimodeling approach is proposed for the nonlinear DPS with multiple working points. To obtain a reasonable operating space division, an iterative approach is proposed where the operating space division and local modeling are performed iteratively. The working range of the current local model will help to determine the next operating point required for modeling. Utilizing the potential of each local model, the number of regions can be reduced. In the local modeling, the Karhunen–Loève method is used for the space/time separation and dimension reduction, and after that unknown parameters of kernels are estimated. Due to consideration of time-scale properties in the dimension reduction, the modeling approach is particularly suitable for dissipative PDEs, particularly of parabolic type. The multimodeling and space/time separation techniques can largely reduce the complexity of global nonlinear spatiotemporal modeling. Finally, to guarantee a smooth transition between local spatiotemporal models, a scheduling integration method is used to provide a global spatiotemporal model. To design scheduling functions, a two-stage training method is proposed to reduce the design complexity. Compared with direct global modeling, the exciting experiment and modeling for each local region become easier. Compared with one local modeling, the multimodel integration will improve modeling accuracy. The effectiveness of the proposed modeling approach is verified by simulations.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301593u

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13195-13204

Titre :	Optimization of experimental parameters to suppress nozzle clogging in inkjet printing
Type de document :	texte imprimé
Auteurs :	Ayoung Lee, Auteur ; Kai Sudau, Auteur ; Kyung Hyun Ahn, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13195-13204
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Optimization
Résumé :	Stable drop jettability is mandatory for a successful, technical scale inkjet printing, and accordingly, this aspect has attracted much attention in fundamental and applied research. Previous studies were mainly focused on Newtonian fluids or polymer solutions. Here, we have investigated the drop jetting for zinc oxide (ZnO) particulate suspensions. Generally, the inverse Ohnesorge number Z = Oh―1, which relates viscous forces to inertia and surface tension, is sufficient to predict the jettability of single phase fluids. For the inkjet printer setup used here, jetting was possible for Newtonian fluids with 2.5 < Z < 26, but in the identical Z-range, nonjetting and nozzle clogging occurred for certain suspensions. A so-called ring-slit device, which allows for simultaneous formation and detection of aggregates in strongly converging flow fields, and single particle detecting techniques, which allow for an accurate determination of the number and size of micrometer-sized aggregates in suspensions of nanopartides, were used to study this phenomenon. Nozzle dogging is induced by heterocoagulation of micrometer-sized aggregates and ZnO nanopartides in the elongational flow field at the nozzle exit. Clogging may occur even if the size of these aggregates is well below the nozzle diameter and their concentration is on the order of only a few hundred parts per million (ppm). Accordingly, increased colloidal stability of nanoparticles and reduced aggregate concentration result in better drop jettability. Also, a nozzle design resulting in a shorter exposure time of the ink to elongational flow and an increased flow velocity helps to avoid nozzle clogging.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26451469

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13182–13194

Titre :	Robust tuning and performance analysis of 2DoF PI controllers for integrating controlled processes
Type de document :	texte imprimé
Auteurs :	Victor M. Alfaro, Auteur ; Ramon Vilanova, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13182–13194
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Robust tuning method
Résumé :	The aim of this paper is to present a robust tuning method and a closed-loop performance analysis of two-degree-of-freedom proportional integral controllers for integrating controlled processes. A closed-loop model reference optimization method has been followed with nonoscillatory and under damped response targets. It has been found that nonoscillatory response targets produce smoother controller outputs and that the regulatory and servo-control performance (integrated absolute error and setting time) may be improved if lightly-under-damped responses are allowed. The proposed tuning method allows the designer to deal with the performance/robustness trade-off of the resulting closed-loop control system by specifying the desired robustness level through selecting a maximum sensitivity in the range from 1.4 to 2.0. Controller tuning equations that guarantee the design robustness level are provided for integrating second-order plus dead-time models with normalized dead-times in the range from 0.1 to 2.0, and integrating plus dead-time models. The robustness of the control system is analyzed. Comparative examples show the effectiveness of the proposed tuning method. The exact achievement of the control system robustness target for all the integrated controlled processes models considered is the distinctive characteristic of the proposed model reference robust tuning method.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300605w

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13173–13181

Titre :	Immobilizing penicillin G acylase using silica-supported ionic liquids : The effects of ionic liquid loadings
Type de document :	texte imprimé
Auteurs :	Huacong Zhou, Auteur ; Liangrong Yang, Auteur ; Wei Li, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13173–13181
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Loading Ionic liquid
Résumé :	The supported ionic liquids (SILs) were prepared via immobilizing silane-functionalized ionic liquids (IL) onto the monodispersive silica nanoparticles, and the composite material was then applied in the immobilization of penicillin G acylase (PGA, EC 3.5.1.11), an important industrial enzyme for the production of semisynthetic antibiotics. This was a novel approach of immobilizing PGA proposed in our previous report, in which we had studied the effects of IL types on the performance of this novel support. Here, we focused on the effects of IL loading on the properties of the SILs and their performance in PGA immobilization. The effects of silica sizes and routes of preparing SILs (the solvent route and the sol-gel route) on IL loading were investigated. The results showed that (1) the IL loading could be tuned efficiently by changing the silica sizes. (2) As compared with the solvent route, the sol-gel route is more simple, time-saving, and ecofriendly in operation. What's more, it has a higher IL loading. Among the factors affecting the IL loading, the reaction time was the most feasible factor to control to tune the IL loading, as compared with the temperature and the dosage of ILs. (3) With the increase of IL loading, the surface ζ-potential of silicas changed from negative to positive, and the isoelectronic point (IEP) increased accordingly, which caused the decrease of the protein loading but the increase of apparent and specific activity. A reusability experiment showed that the sol-gel 1 sample maintained approximately 55% of the initial activity even after 10 consecutive operation cycles under the experimental conditions. This activity was 3.7 times higher than that of the sol-gel 2 sample.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26451467

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13164-13172

Titre :	Carboxymethyl chitosan-functionalized magnetic nanoparticles for disruption of biofilms of staphylococcus aureus and escherichia coli
Type de document :	texte imprimé
Auteurs :	Tong Chen, Auteur ; Rong Wang, Auteur ; Li Qun Xu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13164-13172
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Bacteria Enterobacteriaceae Escherichia coli Biofil Disruption Nanoparticle
Résumé :	Bacteria in biofilms are much more resistant to antibiotics and microbicides as compared to their planktonic stage. Thus, to achieve the same antibacterial efficacy, a much higher dose of antibiotics is required for-biofilm bacteria. However, the widespread use of antibiotics has been recognized as the main cause for the emergence of antibiotic-resistant microbial species, which has now become a major public health crisis globally. In this work, we present an efficient nonantibiotic-based strategy for disrupting biofilms using carboxymethyl chitosan (CMCS) coated on magnetic iron oxide nanoparticles (CMCS-MNPs). CMCS-MNPs demonstrate strong bactericidal activities against both Gram-positive Staphylococcus aureus (S. aureus) and Gram-negative Escherichia coli (E. coli) planktonic cells. More than 99% S. aureus and E. coli planktonic cells were killed after incubation with CMCS-MNPs for 10 and 5 h, respectively. In the presence of a magnetic field (MF), CMCS-MNPs can effectively penetrate into both S. aureus and E. coli biofilms, resulting in a reduction of viable cells counts by 84% and 95%, respectively, after 48 h incubation, as compared to the control experiment without CMCS-MNPs or CMCS. CMCS-MNPs are noncytotoxic toward mammalian cells and can potentially be a useful antimicrobial agent to eliminate both planktonic and biofilm bacteria.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26451466

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13157-13163

Titre :	Preparation and characterization of silanized TiO2 nanoparticles and their application in toner
Type de document :	texte imprimé
Auteurs :	Weishuang Ni, Auteur ; Songping Wu, Auteur ; Qun Ren, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13157-13163
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Nanoparticle Titanium oxide Preparation
Résumé :	Surface modification of TiO2 nanoparticles with 3-methacrylic acyloxy propyl trimethoxysilane (KH570) was carried out in the liquid phase. The modified TiO2 nanoparticles, as charge control agents (CCAs), were added to toner. Infrared and X-ray photoelectron spectroscopies provided strong indications of the formation of organic links between the TiO2 and the KH570. The thick coating layer of KH570 deposited on the surface of TiO2 nanoparticles was determined to be about 2―5 nm by transmission electron microscopy. The hydrophobicity of the modified toner decreased when the amount of coated KH570 reached 5.28 wt % and then increased with further increasing amount of coated KH570. The charge-to-mass ratio (Q/M) of the modified toner shifted in the negative direction with increasing amount of coated KH570; however, with increasing amount of modified TiO2, the value of Q/M shifted in the positive direction. The reason for this difference is that the OH groups existing on the surface of TiO2 transferred from the toner to the carrier after friction.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26451465

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13150-13156

Titre :	Synthesis of iron-doped titanium oxide nanoadsorbent and its adsorption characteristics for fluoride in drinking water
Type de document :	texte imprimé
Auteurs :	Lin Chen, Auteur ; Shuai He, Auteur ; Bo-Yang He, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13150-13156
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Drinking water Adsorption Titanium oxide
Résumé :	A novel iron-doped titanium oxide adsorbent was synthesized by precipitation from a solution of Ti(SO4)2 and FeSO4 and used for fluoride removal from drinking water. The effects of the final pH of the precipitation solution on the adsorbent structure were investigated, and optimized conditions for the synthesis were obtained. The iron doped into the titanium oxide increased the amount of active hydroxyl groups on the adsorbent surface, which increased the fluoride adsorption capacity. The optimized adsorbent had an adsorption capacity of 53.22 mg/g, obtained by fitting adsorption data to the Langmuir isotherm. The adsorption of fluoride followed second-order kinetics. The initial pH of the fluoride solution had little effect on the adsorption capacity. A thermodynamics analysis showed that the adsorption of fluoride ions onto the adsorbent was spontaneous. The adsorbent was easily regenerated with an alkali solution.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26451464

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13144-13149

Titre :	Evaluating surfactants and their effect on methane mole fraction during hydrate growth
Type de document :	texte imprimé
Auteurs :	Jonathan Verrett, Auteur ; Phillip Servio, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13144-13149
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Surfactant
Résumé :	Little work has been done to characterize the effects of surfactant concentration on hydrate growth. The focus of this study is to investigate the effects of gemini and conventional surfadants on hydrate growth and evaluate growth promotion of a variety of surfactants in a consistent manner. The effects of sodium dodecyl sulfate (SDS) and DOWFAX 8390 surfactants on methane hydrates formed in a stirred 600 cm3 reactor containing 343 cm3 of liquid were investigated. Solubility experiments under liquid―hydrate―gas equilibria were conducted at 275.1K with pure water and solutions of each surfactant. Kinetic experiments were performed at 275.1 K and 4545 kPa with surfactant concentrations ranging from 0 to 1150 ppm for SDS and 0 to 200 ppm for DOWFAX 8390. Methane mole fraction measurements were taken at various times throughout the kinetic experiments. Both surfactants were found to have no effect on methane solubility in a gas―liquid―hydrate system at equilibrium. The surfactants did however have a pronounced effect on bulk methane mole fraction during kinetic experiments at surfactant concentrations that significantly promoted hydrate growth. Average hydrate growth rate was measured at various surfactant concentrations, and a sigmoidal trend was observed for both surfactants. Data showed a smooth rather than instantaneous increase in growth rate. A mathematical model is proposed and applied to compare the effectiveness of both surfactants at promoting hydrate growth. DOWFAX 8390 and SDS solutions both promote growth more than 4.5 times that of water samples, but DOWFAX 8390 achieves this promotion at 1/4 the concentration of SDS and has a larger increase in promotion per unit mass of surfactant added. The role of surfactants at the hydrate―liquid and gas―liquid interfaces is discussed.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26451463

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13132-13143

Titre :	Steam reforming of ethanol on copper catalysts derived from hydrotalcite-like materials
Type de document :	texte imprimé
Auteurs :	A. F. Cunha, Auteur ; Y. J. Wu, Auteur ; J. C. Santos, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13132-13143
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Catalyst Steam reforming
Résumé :	Steam reforming of ethanol (SRE) and sorption enhanced steam reforming of ethanol (SE-SRE) on Cu,Zn,Al matenals was studied in the temperature range between 200 and 600 °C for hydrogen production. Precursors with different structures, such as a hydrotalcite-like compound (CuZnAl-HT), zincian malachite derivative (CuZnAl-REF, a reference catalyst precursor for the synthesis of methanol) and amorphous material with embedded copper particles (CuZnAl-ECP), were employed to obtain the active phases. Among the three samples used, the CuZnAl-HT catalyst shows the highest activity (ethanol and water conversion) and selectivity (hydrogen yield). This material also shows a satisfying stability, as the ethanol conversion only decreases around 20% at 400 °C during 12 h of lifetime test. In addition, carbon dioxide uptake during the transient period of SRE was found on the CuZnAl based materials. Especially for the CuZnAl-HT catalyst a SE-SRE phenomena was perfectly observed at 400 °C due to a relative good interaction of carbon dioxide formed in the initial transient period of reaction and the ZnO phase present in the catalyst. Probably, also retained traces of the hydrotalcite-like precursor structure on the CuZnAl-HT catalyst used are responsible for the observed SE-SRE phenomena. Breakthrough tests were performed with the CuZnAl-HT catalyst. This material shows a carbon dioxide adsorption capacity from 0.11 to 0.18 mol/kg, which is a prerequisite for SE-SRE.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26451462

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13123–13131

Titre :	Attrition studies of an iron fischer–tropsch catalyst used in a pilot-scale stirred tank slurry reactor
Type de document :	texte imprimé
Auteurs :	Tie-jun Lin, Auteur ; Xuan Meng, Auteur ; Shi Li, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13123–13131
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Catalysts
Résumé :	Attrition resistance is a key design parameter for catalysts used in slurry phase Fischer–Tropsch (F–T) reactors, especially for industrial-scale reaction. It is well-known that iron F–T catalyst particles undergo physical attrition and chemical stresses caused by phase transformations. Here we report on attrition properties of a Fe–Cu–K–SiO2 catalyst used in a pilot-scale stirred tank slurry reactor (STSR) under low temperature F–T reaction conditions. The wax-free catalysts were characterized by SEM, EDS, BET surface area measurements, and a Mastersizer 2000 for particle size analysis. The results show that, after 408 h of reaction in an STSR, the particle size reduction due to erosion/abrasion and fracture was apparent. Large reductions in the Sauter mean diameter (93.45%) and the volume moment diameter (71.67%) were observed. The increase in the fractions of particles smaller than 5 and 10 μm was 18.25 and 30.11%, respectively. We concluded therefore that the catalyst underwent more severe attrition in industrial application and the attrition was mainly caused by the fracture of larger or smaller particles. Further study is needed to improve the catalyst attrition resistance.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3014428

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13113–13122

Titre :	Catalyst properties and catalytic performance of char from biomass gasification
Type de document :	texte imprimé
Auteurs :	Naomi B. Klinghoffer, Auteur ; Marco J. Castaldi, Auteur ; Ange Nzihou, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13113–13122
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Biomass Gasification
Résumé :	Gasification provides a mechanism to convert solids, such as biomass, coal, or waste, into fuels that can be easily integrated into current infrastructure. This paper discusses the use of residual char from a biomass gasifier as a catalyst for tar decomposition and presents an investigation of the catalytic properties of the char. Poplar wood was gasified in a fluidized bed reactor at temperatures ranging from 550 to 920 °C in reaction environments of 90% steam/10% N2 and 90% N2/10% CO2. The properties of the char recovered from the process were analyzed, and the catalytic performance for hydrocarbon cracking reactions was tested. Brunauer–Emmett–Teller (BET) measurements showed that the surface area of the char was higher than conventional catalyst carriers. The surface area, which ranged from 429 to 687 m2 g–1, increased with temperature and reaction time. The catalytic activity of the char was demonstrated through testing the catalytic decomposition of methane and propane to produce H2 and solid carbon. Higher char surface area resulted in increased performance, but pore size distribution also affected the activity of the catalyst, and evidence of diffusion limitations in microporous char was observed. Clusters of iron were present on the surface of the char. After being used for catalytic applications, carbon deposition was observed on the iron cluster and on the pores of the char, indicating that these sites may influence the reaction. When the char was heated to 800 °C in an inert (N2), atmosphere mass loss was observed, which varied based on the type of char and the time. ESEM/EDX showed that when char was heated to 1000 °C under N2, oxygen and metals migrated to the surface of the char, which may impact its catalytic activity. Through investigating the properties and performance of biomass gasification char, this paper demonstrates its potential to replace expensive tar decomposition catalysts with char catalysts, which are continuously produced on-site in the gasification process.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3014082

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13100-13112

Titre :	Prediction of solids accumulation in slurry bubble columns with polydispersed solid loadings
Type de document :	texte imprimé
Auteurs :	Ion Iliuta, Auteur ; Faïçal Larachi, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13100-13112
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Loading Particle suspension Bubble column Prediction
Résumé :	A core-annulus multicompartment pseudo-2D two-bubble class model accounting for gas and slurry recirculation and coupled with catalyst sedimentation/advection/dispersion/lateral exchange balance equations for monodispersed and polydispersed solid particle systems was proposed to study the hydrodynamics of slurry bubble column facing solids accumulation in the reactor. The distribution of bubbles was represented by a bimodal two-class distribution: large and small bubbles. The model was coupled with a Prandtl—Nikuradse mixing length shear turbulence model or Sato bubble-induced and shear turbulence model to obtain the radial slurry velocity profile. A criterion for setting the onset of particles accumulation in the slurry bubble column was established. In solids polydispersed feeds, the influence of operating conditions (column diameter and height, solids feed mass flux and concentration, particle size distribution, gas velocity, and liquid viscosity) on the threshold particle size corresponding to the onset of particles accumulation in the reactor was analyzed systematically.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26451459

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13092–13099

Titre :	Chlorinated byproducts from the fenton-like oxidation of polychlorinated phenols
Type de document :	texte imprimé
Auteurs :	Macarena Munoz, Auteur ; Zahara M. De Pedro, Auteur ; Gema Pliego, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13092–13099
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Oxidation Phenols
Résumé :	Fenton-like oxidation has proved to be highly efficient in the degradation of polychlorinated phenols (poly-CPs) at 50 °C provided that the H2O2 dose is adjusted appropriately. Using the theoretical stoichiometric H2O2/poly-CP molar ratio allowed a high mineralization of the starting poly-CPs, with negligible residual concentrations of chlorinated organic species and a dramatic reduction of ecotoxicity. Nevertheless, at substoichiometric H2O2 doses, a wide variety of chlorinated condensation byproducts (chlorinated diphenyl ethers, biphenyls, and dibenzofurans) were detected. A chlorinated aromatic iron-containing solid polymer was also formed. At these substoichiometric H2O2 doses, the ecotoxicity values even increased with respect to those of the starting poly-CPs. A reaction scheme is proposed to describe the Fenton-like oxidation of poly-CPs that includes all of the intermediates detected under substoichiometric conditions and used to develop a kinetic model based on TOC lumps. This kinetic model describes fairly well the time evolution of TOC upon the Fenton-like oxidation of poly-CPs.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3013105

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13085-13091

Titre :	Studies on the regeneration mechanism of Mg-Al-Ce-Fe mixed spinel De-SOx additives
Type de document :	texte imprimé
Auteurs :	Wen-Hui Yang, Auteur ; Qiang Zhang, Auteur ; Chun-Yi Li, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13085-13091
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Additive
Résumé :	The regeneration mechanism of sulfur species formed on the Mg-Al-Ce-Fe mixed-spinel sulfur-transfer additives is clarified in this paper. Sulfate is the main sulfur species on the sulfur-transfer catalysts after the oxidative adsorption of SO2, and the S―O bond within sulfates shows lower stability in spinel phase than in the MgO phase. The reduction of these sulfate species leads to the emission of SO2 as well as H2S, and the formation of the two reductive products are both correlated with the change in Mg/Al ratio; however, SO2 is much more sensitive. When the regeneration was conducted at 550 °C, only H2S was observed as a reductive product; yet, at 700 °C, the small amount of H2S was preceded by a large amount of SO2. The mechanism for the sulfate reductive decomposition has been proposed that sulfite is the intermediate, which can be pyrolyzed into SO2 or undergo redox reaction to form H2S. The pyrolysis reaction is closely related to the relative magnitudes of the energy provided and required to break the S―O bond in sulfates, while the probability of the redox reaction is more likely to be dependent on the H2 concentration. Sulfur-transfer additives with more surface-active sites should be developed to enhance the reductive ability, since more time is needed for the bulk-like sulfate to be reduced.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26451457

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13073–13084

Titre :	Joint Transformation of Methanol and n-Butane into Olefins on an HZSM-5 Zeolite Catalyst in Reaction–Regeneration Cycles
Type de document :	texte imprimé
Auteurs :	Andrés T. Aguayo, Auteur ; Ana G. Gayubo, Auteur ; Ainara Ateka, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13073–13084
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Methanol Zeolite Catalys
Résumé :	The joint transformation of methanol and n-butane has been studied under energy-neutral conditions (methanol/n-butane molar ratio of 3/1) on an HZSM-5 zeolite catalyst in order to determine the reactivation kinetics and optimize the process conditions for maximizing the light olefin production rate. The methodology for determining the reactivation kinetics combines the kinetic models for the main reaction and deactivation (determined in previous studies), as well as the experimental reactivation results obtained for a reaction step (at 500 and 550 °C) subsequent to regeneration by coke combustion with air (at 550 °C, up to 120 min). By simulation of the operation in reaction–regeneration cycles, an optimum average olefin production rate of 22 mol/(gcatalyst h) is obtained for a reaction temperature of 500 °C, space time of 0.37 gcatalyst h mol–1, time on stream of 40 min, and partial reactivation by coke combustion for 15 min.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301142k

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13062-13072

Titre :	Improved transfer coefficients for wall-flow monolithic catalytic reactors : Energy and momentum transport
Type de document :	texte imprimé
Auteurs :	Margaritis Kostoglou, Auteur ; Edward J. Bissett, Auteur ; Athanasios G. Konstandopoulos, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13062-13072
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Transport process Momentum Catalytic reactor Monolithic construction
Résumé :	Wall-flow monolithic (WFM) catalytic reactors occupy an ever increasing important position in environmental and industrial catalysis as well as in energy applications. Their performance is very frequently determined by transport (momentum, energy, and mass) limitations, driven by the market needs for lower pressure drop, efficient heat exploitation, and miniaturization. In the present problem we address the problem of deriving the appropriate single channel equations that describe heat transfer in a wall-flow monolithic (WFM) reactor with porous channels of square-cross section. The first step of the study involves setting up a self-similar hydrodynamic problem for the two-dimensional flow field in the channel cross section. This flow field depends only on the so-called wall Reynolds number. It is shown that the self-similarity fails for large values of wall Reynolds number. The second step involves setting up the Graetz problem for the flow velocity profile found in the first step and solving for the asymptotic Nusselt number. This Nusselt number depends on the Prandtl number in addition to the wall Reynolds dependence through the flow-field. Correlations for the Nusselt number as a function of wall Reynolds and Prandtl numbers are given to facilitate the inclusion of these effects into standard practice.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26451455

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13054–13061

Titre :	Modeling of gas liquid taylor flow in capillaries by using a two fluid model
Type de document :	texte imprimé
Auteurs :	Bin Cao, Auteur ; Lingai Luo, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13054–13061
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Gas liquid taylor
Résumé :	This work proposes a two fluid model for predicting gas liquid Taylor flow in capillaries. The model is based on the hydrodynamics characteristics of Taylor bubbles and liquid slug. By considering a unit cell consisting of a bubble and a liquid slug as control volume, conservation of momentum equations for gas and liquid film is combined and solved with a set of empirical closure equations. We also propose a new expression for the interfacial friction factor, which takes the influences of surface tension, the liquid velocity and viscosity and the gas holdup into account. By combining this new expression with the two fluid model, we can calculate the hydrodynamic characteristics of gas–liquid Taylor flow in capillaries for different channels diameters and working fluids. The model is validated by experimental results reported in existing literature. Very good agreement can be observed, demonstrating its potential application in predicting the phenomena of Taylor flow in capillaries.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300817f

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13046–13053

Titre :	Hydrogen production from a victorian brown coal with in situ CO2 capture in a 1 kWth dual fluidized-bed gasification r
Type de document :	texte imprimé
Auteurs :	Hui An, Auteur ; Tao Song, Auteur ; Laihong Shen, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13046–13053
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Hydrogen Gasification
Résumé :	The removal of CO2 during coal gasification will improve H2 yield by promoting coal gasification reactions toward the production of H2. In this work, coal gasification with in situ CO2 capture has been investigated in a 1 kWth dual fluidized-bed gasification reactor. A Victorian brown coal was used as the feed stock. Coal gasification tests at 700 °C were performed with silica sands as the heat carrier and synthetic CaO sorbent for comparison. It was found that the addition of the sorbent improved H2 concentration in the outlet of the fuel reactor by nearly 53%. Carbon conversion rate was also increased and a maximum of 33% was reported. Calcium aluminate cement was used as a binder for the fabrication of the synthetic CaO sorbent, in an attempt to enhance its mechanical strength and improve its chemical properties.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300747m

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13037-13045

Titre :	Effect of nickel-containing layered double hydroxides and cyclophosphazene compound on the thermal stability and flame retardancy of poly(lactic acid)
Type de document :	texte imprimé
Auteurs :	Xueying Shan, Auteur ; Lei Song, Auteur ; Weiyi Xing, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13037-13045
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Flame Thermal stability
Résumé :	Hydrotalcite-like anionic clays or layered double hydroxides with dodecylbenzenesulfonate anions (NiFe, NiAl, and NiCr LDH-SDS, where SDS denotes sodium dodecyl sulfate) were prepared by the coprecipitation method. Hexaphenoxycyclotriphosphazene (HPCP) is an effective cyclophosphazene flame retardant. The HPCP molecule contains a cyclic backbone consisting of alternating phosphorus and nitrogen atoms. LDH-SDS and HPCP were first used to prepare poly(lactic acid) (PLA) composites. One goal of this work was to compare the thermal stability and flame retardancy of PLA/ HPCP/LDH-SDS composites. The structures and properties of LDH-SDS materials were characterized by X-ray diffraction (XRD), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and thermogravimetric analysis (TGA). Thermal analysis and char residue analysis of PLA/HPCP/LDH-SDS composites suggested that NiFe, NiAl, and NiCr LDH-SDS materials play different roles in improving the thermal stability and flame retardancy of PLA composites. The effective mechanism of LDH-SDS and HPCP in PLA composites is also hypothesized in this work.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26451452

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13021-13036

Titre :	Transacetalization of Glycerol with Methylal by Reactive Distillation
Type de document :	texte imprimé
Auteurs :	Amit Hasabnis, Auteur ; Sanjay Mahajani, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13021-13036
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Distillation with reactio
Résumé :	The applicability of reactive distillation (RD) for the transacetalization of glycerol with methylal in the presence of Amberlyst-15 is studied by experiments and simulation. On the basis of the batch kinetic runs a pseudohomogeneous kinetic model is proposed. The experiments are performed on a continuous reactive distillation column and are compared with the predictions of the equilibrium stage model. Various feasible configurations of reactive distillation are identified and the experimentally validated simulator is used to investigate the effect of different design and operating parameters such as number of rectifying stages, stripping stages, feed mole ratio, followed duty, etc on the performance in each case. The RD process alternatives and the conventional process of reaction followed by distillation are compared.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26451451

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13014-13020

Titre :	Prunus domestica fruit extract-mediated synthesis of gold nanoparticles and its catalytic activity for 4-nitrophenol reduction
Type de document :	texte imprimé
Auteurs :	Preeti Dauthal, Auteur ; Mausumi Mukhopadhyay, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13014-13020
Note générale :	industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Catalyst activity Nanoparticle Extract
Résumé :	Gold nanoparticles (Au-NPs) were synthesized at room temperature using Prunus domestica (plum) fruit extract as reducing agent. The UV―visible absorption spectrum showed a characteristic optical absorption peak of Au-NPs at 543 nm. The X-ray diffraction pattern suggested the formation and crystallinity of Au-NPs. Spherical Au-NPs synthesized with an average particle size of 20 ± 6 nm were confirmed by transmission electron microscopy. Fourier transform infrared spectroscopy analysis supported the role of water-soluble polyols and amino adds of plum fruit extract for bioreduction and stabilization of Au-NPs. The catalytic activity of Au-NPs was investigated for 4-nitrophenol (4-NP) reduction using UV―visible absorption spectroscopy. Biosynthesized Au-NPs showed a dose-dependent catalytic activity. Catalytic reduction followed pseudo-first-order kinetics with respect to 4-NP.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26451450

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13008-13013

Titre :	Alkaline ionic liquids as catalysts : A novel and green process for the dehydration of carbohydrates to give 5-hydroxymethylfurfural
Type de document :	texte imprimé
Auteurs :	Yong-Shui Qu, Auteur ; Yan-Lei Song, Auteur ; Chong-Pin Huang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13008-13013
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Dehydration Catalyst Ionic liquid
Résumé :	An efficient process for the conversion of carbohydrates into 5-hydroxymethylfurfural (5-HMF) catalyzed by the room temperature ionic liquid (IL) 1-butyl-3-methylimidazolium hydroxide ([BMIM]OH), using dimethyl sulfoxide (DMSO) as solvent, has been developed. The yield of 5-HMF obtained by hydrolysis of fructose at 160 °C with a mass ratio IL:fructose of 0.5 was 91.6%. The effects of varying the solvent, IL concentration, temperature, and reaction time on the reaction were studied in detail. The activation energy of fructose conversion was determined to be 99.2 kJ·mol―1, with a pre-exponential factor of 2.1 × 108. Furthermore, the catalyst also exhibited good activity for the dehydration of sucrose to 5-HMF under the same conditions.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26451449

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - pp. 13001-13007

Titre :	Mechanism of tar generation during fluidized bed gasification and low temperature pyrolysis
Type de document :	texte imprimé
Auteurs :	Ute Wolfesberger-Schwabl, Auteur ; Isabella Aigner, Auteur ; Hermann Hofbauer, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13001-13007
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Pyrolysis Low temperature Gasification Fluidized bed Fluidization
Résumé :	This work focuses on the comparison of two different thermal conversion processes with respect to different tar amounts and tar compositions at different temperatures and process parameters. Steam gasification experiments were carried out in a 100 kW dual fluidized bed steam gasifier at a temperature range of 700 to 870 °C with straw and wood. Pyrolysis experiments were conducted in a rotary kiln reactor at temperatures between 600 and 630 °C and straw as fuel. For better understanding of tar formation during thermo-chemical conversion of biomass, the tar content and composition in the product gas were analyzed with a gas chromatograph coupled with a mass spectrometer. The main observation was that at higher temperatures the tar composition is shifted to higher molecular tars such as polyaromatic hydrocarbons (PAH). Key tar components at lower temperatures (pyrolysis) are phenols. The tar content and composition in the product gas of steam gasification of straw and wood as well as the tar yields and composition of low temperature pyrolysis of straw are presented in the following work.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26451448

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 40 (Octobre 2012) . - Mingzhu Liu

Titre :	Novel multinutrient fertilizer and its efect on slow release, water holding, and soil amending
Type de document :	texte imprimé
Auteurs :	Boli Ni, Auteur ; Shaoyu Lü, Auteur ; Mingzhu Liu, Auteur
Année de publication :	2012
Article en page(s) :	Mingzhu Liu
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Fertilization
Résumé :	This study was carried out to develop a novel slow-release fertilizer, which is based on natural attapulgite (APT) clay as a matrix, guar gum (GG) as an inner coating, and guar gum-g-poly(itaconic add-co-acrylamide)/humic acid (GG-g-P(IA-co-AM)/HA) superabsorbent polymer as an outer coating. The coated compound fertilizer granules with diameter in the range of 2-3 mm possess low moisture content and high mechanical hardness. The effects of APT matrix, GG, and superabsorbent polymer coatings on nutrients release were explored. The influence of the product on water-holding capacity of soil was determined. The degradation behavior of the GG-g-P(IA-co-AM)/HA outer coating was assessed by examining the weight loss with incubation time in soil. The experimental data and analysis in this study indicated that the product prepared by a simple route can effectively reduce nutrient loss in runoff or leaching, improve soil moisture content, and regulate soil acidity and alkalinity level.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26451447

Industrial & engineering chemistry research / Paul, Donald R. . Vol. 51 N° 40

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