Catalogue en ligne Bibliothèque Ecole Nationale Polytechnique d'Alger

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13862-13868

Titre :	Effect of Uracil on the Isothermal Melt Crystallization Kinetics and Polymorphic Crystals Control of Biodegradable Poly(butylene adipate)
Type de document :	texte imprimé
Auteurs :	Mengting Weng, Auteur ; Yingran He, Auteur ; Zhaobin Qiu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13862-13868
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Kinetics Melt crystallization
Résumé :	Biodegradable poly(butylene adipate) (PBA) and uracil composites were prepared via a solution and casting method at low uracil loadings in this work. The isothermal melt crystallization rate has been increased apparently in the composites by the addition of uracil, which acts as a nucleating agent for the crystallization of PBA. PBA may crystallize in the α-or β-form under different conditions. During the nonisothermal melt crystallization, the α-form crystals of neat PBA are formed at only relatively slow cooling rate; however, the formation of α-form crystals can be induced by uracil in the composites at relatively faster cooling rates. The formation of polymorphic crystals of PBA may be regulated by changing cooling rate and the uracil loading, which provides an efficient way of controlling the polymorphic crystals formation and biodegradation behaviors.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26508211

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13853–13861

Titre :	Toward a unified framework for interpreting the phase rule
Type de document :	texte imprimé
Auteurs :	R. Ravi, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13853–13861
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Phase rule
Résumé :	The apparent differences in the statements of the phase rule for the two sets of variables commonly used, namely, temperature, pressure, and mole fractions on the one hand and temperature, pressure, and chemical potentials on the other are resolved by developing a framework in which the phase rule may be stated and analyzed in terms of a whole class of variable sets. The framework is restricted to the case where all the components are present in all the phases. Central to the framework is the notion, due to Gibbs, of a fundamental relation for homogeneous states and the associated general equation cast in terms of intensive and specific variables. The significance of the Gibbs–Duhem equations within the context of the phase rule is brought out. The lead provided by Gibbs in his approach to the phase rule is utilized to carry out a local analysis of the equations that result from the criteria of equilibrium for the two sets of variables referred to above. The central role played by the general equations is brought out. The scope of the phase rule is widened by identifying particular sets of variables that would be suitable for uniquely defining the equilibrium state of a multiphase mixture.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301417n

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13846-13852

Titre :	Thermodynamic modeling of mixtures containing carboxylic acids using the PC-SAFT equation of state
Type de document :	texte imprimé
Auteurs :	Chen Yushu, Auteur ; Attia Afef, Auteur ; Mutelet Fabrice, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13846-13852
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Thermodynamic properties Equations of state Modeling
Résumé :	The aim of this work is to investigate whether the PC-SAFT (pertubed chain-statistical associating fluid theory) equation of state can describe the vapor―liquid equilibria for carboxylic acid-containing systems. Carboxylic acids, unlike many other associating compounds, have a strong tendency to dimerize in the vapor phase at normal conditions resulting in strong nonideal behavior at low pressures. In this work, we will focus on five binary systems {water + acetic acid}, {water + propionic acid}, {water + acrylic acid}, {acetic acid + propionic acid}, and {acetic acid + acrylic acid} due to their importance for chemical industries. The study was performed in a systematic method: first, the PC-SAFT equation has been applied to the pure carboxylic acid in order to determine the pure molecular parameters and then to the binary system. In this case, the interaction parameter k¡j was determined using liquid―vapor equilibria data. This work shows that the PC-SAFT equation of state is able to represent the pure carboxylic acid as well as mixtures containing carboxylic acid.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26508209

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13839-13845

Titre :	The Discharge of pulverized coal from a pressurized aerated hopper
Type de document :	texte imprimé
Auteurs :	Haifeng Lu, Auteur ; Xiaolei Guo, Auteur ; Xingliang Cong, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13839-13845
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Bin Coal
Résumé :	An aerated discharge system was established in this paper to investigate the discharge of pulverized coal from a pressurized aerated hopper. Two opposite effects of aerated gas on solid were first revealed. "Fluidized pressurization", which effectively fluidized the solid and improved the subsequent hopper discharge, was then developed. The effect of hopper pressure on the discharge of pulverized coal was studied. Our experimental results showed that the gas volumetric flow rate increased and the gas superficial velocity decreased with the increase of the hopper pressure in the range of 0―1800 kPa. It was confirmed that more energy was needed; the uncertainty and instability was increased to discharge pulverized coal at higher pressures. Gas momentum flux was defined and used to describe the effect of aeration. The optimum gas momentum flux, which was independent of the hopper pressure, was obtained on the basis of the experimental data. The optimum gas volumetric flow rates and the optimum gas superficial velocities corresponding to the maximum solid discharge rates were further predicted, which agreed well with the experimental data. On the other hand, the hopper pressure also showed a positive effect on the solid discharge, as the maximum solid discharge rate increased gradually with the hopper pressure until a limit value of about 8000 kg/ h was reached at 800 kPa.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26508208

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13833-13838

Titre :	Adhesion, abrasion, and desulfurization characteristics of rapidly hydrated sorbent with cheap and easily obtained adhesive carrier particles
Type de document :	texte imprimé
Auteurs :	Yuan Li, Auteur ; Changfu You, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13833-13838
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Adhesive Desulfurization Abrasion Adhesion
Résumé :	Adhesive carrier particles have important technical and economic influence on circulating fluidized bed flue gas desulfurization (CFB-FGD) systems that use rapidly hydrated sorbent. Several cheap and easily obtained materials with rough surfaces and porous structures were used as adhesive carrier particles to prepare rapidly hydrated sorbent: the fly ash from the first electrical field in the electrostatic precipitator (ESP) of a circulating fluidized bed (CFB) boiler, the fly ash from a chain boiler, and river sand. Scanning electron microscopy (SEM), particle size distribution (PSD) analysis, surface and pore analysis, abrasion tests, and thermal gravimetric analysis (TGA) tests were used to examine the influence of the adhesive carrier particles' surface and pore characteristics on the adhesion, abrasion, and desulfurization characteristics of the rapidly hydrated sorbent. Experimental results showed that the CFBB ESP ash, chain boiler ash, and river sand all improved the abrasion and desulfurization characteristics of the rapidly hydrated sorbent compared to the coal fly ash. Specifically, the abrasion ratios of the experimental sorbents were all less than 25% compared to 45% for the coal fly ash sorbent, while the desulfurization abilities of the three experimental sorbents were more than 830 mg SO2/g lime compared to 725 mg SO2/g lime for the coal fly ash sorbent. The river sand sorbent had the greatest desulfurization ability and the lowest abrasion ratio, and it possesses the best industrial application potential of all the tested materials.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26508207

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13825-13832

Titre :	Evaluating the behavior of electrolytic gas bubbles and their effect on the cell voltage in alkaline water electrolysis
Type de document :	texte imprimé
Auteurs :	Dongke Zhang, Auteur ; Kai Zeng, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13825-13832
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Electrolysis Bubble
Résumé :	The behavior of electrolytic gas bubbles and their effect on the cell voltage in water electrolysis were studied theoretically and experimentally. A fundamental force analysis was employed to predict the critical diameter for the departure of the electrolytic gas bubbles. Good agreement between the predictions and observations was obtained. It was found that increasing the electrode potential strengthened the force due to the interfacial tension and increased the critical diameter, while increasing the electrolyte concentration led to a reduction. This was explained by the changes in both the contact angle and surface tension. Many more fine gas bubbles were observed at high current density, which was explained by that the enhanced natural convection forced bubbles to depart prematurely. The cell voltage was only slightly reduced by the electrolyte circulation, which reduced the critical diameter for bubble departure. This confirmed that the layer of fine bubbles represented a significant energy barrier, that is, the additional resistance due to the bubble curtain formed on the electrodes, for alkaline water electrolysis.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26508206

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13815-13824

Titre :	Radial bubble distribution in a fluidized bed with vertical tubes
Type de document :	texte imprimé
Auteurs :	Martin Rüdisüli, Auteur ; Tilman J. Schildhauer, Auteur ; Serge M. A. Biollaz, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13815-13824
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Vertical tube Fluidized bed Fluidization Bubble
Résumé :	The radial distribution of bubble characteristics such as the bubble frequency, the bubble size, and the bubble rise velocity, is a key to better understanding the flow patterns of gas (and solids) in bubbling fluidized beds. Therefore, the radial distribution of bubble characteristics is investigated in a fluidized bed with vertical tubes by means of optical probes. Measurements are taken for Geldart B particles at two bed heights, three gas velocities, and three vertical tube bank configurations. While the bubble frequency shows a strong dependence on the radial position in the bed and the orientation of the vertical tubes, the bubble size and the bubble rise velocity, in particular in the lower portions of the bed, are more constant. Typical bubble pathways are shown to move from the column wall to the center axis of the bed with increased bed height. Therefore, in order to have a representative mean bubble size and mean bubble rise velocity, which accounts for the whole cross-section of the bed, an area-number weighted mean is introduced.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26508205

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13803–13814

Titre :	Modeling of water-spray application in the forced dispersion of LNG vapor cloud using a combined eulerian–lagrangian approach
Type de document :	texte imprimé
Auteurs :	Byung Kyu Kim, Auteur ; Dedy Ng, Auteur ; Ray A. Mentzer, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13803–13814
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	LNG Eulerian lagrangian
Résumé :	The safety and security of liquefied natural gas (LNG) facilities has prompted the need for continued study of LNG mitigation systems. Water-spray curtains are widely recognized as an effective measure for dispersing LNG vapor clouds (Martinsen et al. Hydrocarbon Process. 1977, 56, 260−267). Currently, there are no engineering guidelines available for water-curtain applications in the LNG industry because of a lack of understanding of the complex interactions between the LNG vapor cloud and water droplets. This work applies computational fluid dynamics (CFD) modeling to investigate the dominant mechanisms observed in the forced dispersion of LNG vapor using upward-oriented full-cone spray nozzles. An Eulerian–Lagrangian approach was used for the continuous and discrete phases to simulate the energy and momentum exchange between the two phases. Discussed are the physical parameters that are essential inputs to the CFD simulation of the water spray–LNG system. The prediction results were also validated with the Mary Kay O’Connor Process Safety Center’s LNG outdoor experimental data collected in March 2009 at the Brayton Fire Training Field. On the basis of these findings, dominant mechanisms that govern the effectiveness of water spray in the forced dispersion of LNG vapor clouds are discussed.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3003864

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13792-13802

Titre :	Optimal solvent screening for the crystallization of pharmaceutical compounds from multisolvent systems
Type de document :	texte imprimé
Auteurs :	Ehsan Sheikholeslamzadeh, Auteur ; Chau-Chyun Chen, Auteur ; Sohrab Rohani, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13792-13802
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Crystallization
Résumé :	In this study, an effort has been made to predict the solid―liquid equilibrium (SLE) behavior of different solids (pharmaceuticals) in many common solvents and their mixtures. A modified optimization of a recent thermodynamic model, the NRTL―SAC model, was used in all stages of calculation (VLE, LLE, and SLE predictions). The batch cooling-antisolvent crystallization process was simulated for seven model molecules from the initial temperature to the final temperature and for the volume fraction of each solvent. The feasible region of temperature for each crystallization case was calculated based on the bubble-point temperature of the solvent mixture and the melting point of the model molecules. The NRTL-SAC model was used in conjunction with the optimization procedure to test the complete miscibility of solvents during each part of crystallization. After estimating the optimum solvent mixture (combination) for a specific model molecule, the results for single, binary, and ternary solvent mixtures were compared. The results obtained from the binary and ternary combinations were similar in terms of crystallization yields per mass of solvent mixture and far superior to those obtained with single solvents. The proposed algorithm demonstrates flexibility, simplicity, and accuracy in predicting the phase behavior and eventual optimal solvent screening for the crystallization of pharmaceutical components.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26508203

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13784-13791

Titre :	Cure of filament-caused MBR fouling in the presence of antibiotics : Taking ciprofloxacin exposure as an example
Type de document :	texte imprimé
Auteurs :	Fangang, Meng, Auteur ; Zhizhen Wang, Auteur ; Yue Li, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13784-13791
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Antibiotic Fouling
Résumé :	Pharmaceuticals and personal care products (PPCPs) are ubiquitous in wastewater streams, but little is known regarding their roles in membrane fouling during the operation of membrane bioreactors (MBRs). This study attempted to understand the role of ciprofloxacin exposure in control of filamentous bulking as well as membrane fouling mitigation. Compared with the control MBR, results show that the ciprofloxacin could selectively inhibit and kill filaments present in the mixed liquor, and, as a consequence, the sludge settleability improved significantly. The addition of ciprofloxacin had little influence on organic removals and nitrification, but had an adverse effect on denitrification. In addition, the sludge flocs exposure to ciprofloxacin still kept in compact structure; specifically, granular sludge was finally formed possibly due to the increase of polysaccharides in extracellular polymeric substances (EPS). Characterization by nuclear magnetic resonance (NMR) corroborated the enrichment of polysaccharides in the EPS exposure to ciprofloxacin. On the other hand, because of the release of EPS and the decay of filaments, soluble microbial products (SMP), particularly soluble polysaccharides, increased significantly in the MBR exposure to ciprofloxacin. Despite this, the results of this study show that the presence of trace contaminants in wastewater streams may play some positive roles in MBR fouling control.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26508202

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13773-13783

Titre :	Operating strategy to produce consistent CSD in combined antisolvent-cooling crystallization using FBRM
Type de document :	texte imprimé
Auteurs :	Martin Wijaya Hermanto, Auteur ; Pui Shan Chow, Auteur ; Reginald B. H. Tan, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13773-13783
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Crystallization Cooling
Résumé :	In this study, an operating strategy which uses focused beam reflectance measurement (FBRM) to achieve consistent product quality in a combined antisolvent-cooling crystallization process is developed. The proposed operating strategy involves rapid generation of seed crystals by antisolvent addition, which is followed by a seed conditioning process through gentle heating. Subsequently, the conditioned seed crystals are grown by combined antisolvent addition and cooling. FBRM statistics were used as indications for switching from one operating region to the subsequent one. The operating strategy is demonstrated for the crystallization of paracetamol in acetone-water solution and glycine in water-ethanol solution. The crystal size distribution (CSD) produced by this operating strategy is significantly more consistent than that produced by the unseeded antisolvent crystallization and slightly more consistent than that produced by seeded antisolvent crystallization. The proposed operating strategy also reduces agglomerations in product crystals substantially and is robust in the presence of initial concentration disturbances. Furthermore, a new implementation of a distance measure is proposed for quantitative assessment of product CSD consistency.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26508201

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13765-13772

Titre :	Reappraisal of the skarstrom cycle for CO2 recovery from flue gas streams : New results with potassium-exchanged zeolite adsorbent
Type de document :	texte imprimé
Auteurs :	Anshu Nanoti, Auteur ; Soumen Dasgupta, Auteur ; Nabanita Biswas, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13765-13772
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Zeolite Gaseous effluent Carbon dioxide
Résumé :	CO2―N2 separation performance of a simple Skarstrom type pressure vacuum swing adsorption (PVSA) cycle is compared with a heavy reflux cycle with a potassium exchanged X zeolite adsorbent. Contrary to literature reports, the performance of the Skarstrom cycle has been found to be better under different PVSA process conditions. The best CO2 purity achieved was 92 mol % at a recovery as high as 80% from a feed consisting of 15 mol % CO2 in N2 and under an excellent feed throughput of 790 LSTP/h/kg. The power consumption in the Skarstrom cycle is also found to be lower than in the heavy reflux cycle.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26508200

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - .13743–13764

Titre :	Optimal operation of discretely controlled continuous systems under uncertainty
Type de document :	texte imprimé
Auteurs :	Mariano De Paula, Auteur ; Ernesto C. Martinez, Auteur
Année de publication :	2012
Article en page(s) :	.13743–13764
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Optimal operation Continuous systems
Résumé :	Discretely controlled continuous systems constitute a special class of continuous-time hybrid dynamical systems where timely switching to alternative control modes is used for dynamic optimization in uncertain environments. Each mode implements a parametrized feedback control law until a stopping condition triggers due to the activation of a constraint related to states, controls, or disturbances. For optimal operation under uncertainty, a novel simulation-based algorithm that combines dynamic programming with event-driven execution and Gaussian processes is proposed to learn a switching policy for mode selection. To deal with the size/dimension of the state space and a continuum of control mode parameters, Bayesian active learning is proposed using a utility function that trades off information content with policy improvement. Probabilistic models of the state transition dynamics following each mode execution are fitted upon data obtained by increasingly biasing operating conditions. Throughput maximization in a hybrid chemical plant is used as a representative case study.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301015z

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13732–13742

Titre :	Data-derived analysis and inference for an industrial deethanizer
Type de document :	texte imprimé
Auteurs :	Francesco Corona, Auteur ; Michela Mulas, Auteur ; Roberto Baratti, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13732–13742
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Industrial processes
Résumé :	This paper presents an application of data-derived approaches for analyzing and monitoring industrial processes. The discussed methods are used in visualizing process measurements, extracting operational information, and designing estimation models for primary process variables otherwise difficult to measure in real-time. Emphasis is given to the modeling of the data with two classical machine learning paradigms; the self-organizing map (SOM) and the multi-layer perceptron (MLP). The effectiveness of the proposed approach is validated on an industrial deethanizer, where the goal is to identify operational modes and most sensitive variables for this full-scale unit, as well as design an inferential model for a critical process variable, the bottom ethane concentration. The study led to the definition of a fully automated monitoring tool to be implemented online in the plant’s distributed control system. The results confirmed the potential of the data-derived approach, and based on the analysis, the existing control configuration of the unit could be redefined toward more consistent operations. Because it is general and modular by design, the tool can be easily used for other processes.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202854b

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13732–13742

Titre :	Data-derived analysis and inference for an industrial deethanizer
Type de document :	texte imprimé
Auteurs :	Francesco Corona, Auteur ; Michela Mulas, Auteur ; Roberto Baratti, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13732–13742
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Résumé :	This paper presents an application of data-derived approaches for analyzing and monitoring industrial processes. The discussed methods are used in visualizing process measurements, extracting operational information, and designing estimation models for primary process variables otherwise difficult to measure in real-time. Emphasis is given to the modeling of the data with two classical machine learning paradigms; the self-organizing map (SOM) and the multi-layer perceptron (MLP). The effectiveness of the proposed approach is validated on an industrial deethanizer, where the goal is to identify operational modes and most sensitive variables for this full-scale unit, as well as design an inferential model for a critical process variable, the bottom ethane concentration. The study led to the definition of a fully automated monitoring tool to be implemented online in the plant’s distributed control system. The results confirmed the potential of the data-derived approach, and based on the analysis, the existing control configuration of the unit could be redefined toward more consistent operations. Because it is general and modular by design, the tool can be easily used for other processes.

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13712–13731

Titre :	Root cause analysis of linear closed-loop oscillatory chemical process systems
Type de document :	texte imprimé
Auteurs :	S. Babji, Auteur ; U. Nallasivam, Auteur ; R. Rengaswamy, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13712–13731
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Oscillations
Résumé :	In a single-input single-output (SISO) closed-loop system, under constant or nonoscillatory set-point, oscillations in the output can occur mainly because of one or a combination of the following reasons: (i) presence of stiction in control valve, (ii) marginally stable control loops (because of aggressively tuned controller/changes in process time constant/gain/time delays or a combination of them), and (iii) disturbances external to the loop. The presence of these oscillations can propagate plant-wide and force plants to deviate from optimal operating conditions. Therefore, it is essential to develop techniques that can diagnose the source of oscillations in control loops. Several data-driven methods have been developed to address the diagnosis problem by focusing on only one of the causes for oscillations. In the current study, an off-line data driven approach is developed to identify the root cause for oscillations in control loops using the routine plant operating data. Unlike the existing techniques, this approach identifies and distinguishes between the three major causes for oscillations in linear closed loop systems. The proposed methodology combines both parametric (Hammerstein-based approach) and nonparametric (Hilbert–Huang spectrum) schemes for performing oscillation diagnosis. Simulation and industrial case studies that demonstrate the utility and limitations of the proposed method for root cause diagnosis in closed loop systems are discussed.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie2024323

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13703–13711

Titre :	Capacity planning under clinical trials uncertainty in continuous pharmaceutical manufacturing, 2 : Solution method
Type de document :	texte imprimé
Auteurs :	Arul Sundaramoorthy, Auteur ; Xiang Li, Auteur ; James M. B. Evans, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13703–13711
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Pharmaceutical manufacturing
Résumé :	In Part 1 of this paper, we presented a scenario-based multiperiod mixed-integer linear programming (MILP) formulation for a capacity planning problem in continuous pharmaceutical manufacturing under clinical trials uncertainty. The number of scenarios and, thus, the formulation size grows exponentially with the number of products. The model size easily becomes intractable for conventional algorithms for more than 8 products. However, industrial-scale problems often involve 10 or more products, and thus a scalable solution algorithm is essential to solve such large-scale problems in reasonable times. In this part of the paper, we develop a rigorous decomposition strategy that exploits the underlying problem structure. We demonstrate the effectiveness of the proposed algorithm using several examples containing up to 16 potential products and over 65 000 scenarios. With the proposed decomposition algorithm, the solution time scales linearly with the number of scenarios, whereby a 16-product example with over 65 million binary variables, nearly 240 million continuous variables, and over 250 million constraints was solved in less than 6 h of solver time.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3003254

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13692–13702

Titre :	Capacity planning under clinical trials uncertainty in continuous pharmaceutical manufacturing, 1 : Mathematical framework
Type de document :	texte imprimé
Auteurs :	Arul Sundaramoorthy, Auteur ; James M. B. Evans, Auteur ; Paul I. Barton, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13692–13702
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Pharmaceutical manufacturing
Résumé :	Unlike traditional batch-based pharmaceutical manufacturing, where the active pharmaceutical ingredient (API) and the final drug product are often produced in different facilities at different locations, novel continuous pharmaceutical manufacturing strategies enable the production of both the API and the final drug product in the same integrated facility. The capacities of such integrated continuous facilities must be determined for potential products in the face of clinical trials uncertainty. Given a portfolio consisting of potential products in the development stage, the goal of capacity planning is to ensure the availability of enough production capacity to meet the projected demands of products, which vary from the launch to the peak-demand periods. To address this problem, we propose a multiscenario, multiperiod, mixed-integer linear programming (MILP) formulation that takes into account uncertainty in the outcome of clinical trials. We illustrate the proposed framework using several examples. The exponential increase in problem size with the number of products motivates us to develop an efficient solution method, which is discussed in Part 2 of this paper.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300324h

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13686-13691

Titre :	Effect of low thermally reduced graphene loadings on the crystallization kinetics and morphology of biodegradable poly(3-hydroxybutyrate)
Type de document :	texte imprimé
Auteurs :	Xiangjin Jing, Auteur ; Zhaobin Qiu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13686-13691
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Morphology Kinetics Crystallization Loading
Résumé :	Biodegradable poly(3-hydroxybutyrate) (PHB) and thermally reduced graphene (TRG) nanocomposites have been prepared successfully via a solution and coagulation method in this work at low TRG loadings. The effects of TRG on the crystal structure, spherulitic morphology, nonisothermal melt crystallization behavior, and isothermal melt crystallization kinetics of PHB in the PHB/TRG nanocomposites were investigated with various techniques. It was found that TRG does not change the crystal structure of PHB but apparently increases the nucleation density of PHB spherulites in the PHB/TRG nanocomposites. Moreover, both the nonisothermal and isothermal melt crystallizations of PHB are enhanced significantly in the nanocomposites because of the efficient nucleating agent effect of TRG. In addition, the isothermal melt crystallization kinetics of neat PHB and the PHB/TRG nanocomposites was analyzed by the Avrami equation. The overall isothermal melt crystallization rates of PHB are increased with deceasing crystallization temperature and increasing the TRG loadings in the nanocomposites; however, the crystallization mechanism remains unchanged in spite of the crystallization temperature and TRG loadings.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26508194

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13680-13685

Titre :	Drying of porous coating : Influence of coating composition
Type de document :	texte imprimé
Auteurs :	Joel Songok, Auteur ; Douglas Bousfield, Auteur ; Cathy Ridgway, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13680-13685
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Drying
Résumé :	The influence of the coating composition of a porous paper coating on the evaporation rate of water contained in the sample has been studied experimentally. For low-content latex samples, drying was found to be mainly controlled by capillarity, perhaps also in the form of thin film pore surface feature/wall wetting, which drew water from the connected pores to the drying surface or near the surface. This led to a lengthy constant drying rate period (CDRP) where nearly 70% of the saturated water was evaporated. High-content latex samples, characterized by low porosity and permeability showed shorter CDRP and lengthy falling drying rate period. The drying rate curve varied linearly with time in the CDRP and with the square root of time in the falling rate period, indicating a diffusive controlled mechanism. Low latex content samples took less time to dry, which can be inferred to mean they require less drying energy.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26508193

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13670–13679

Titre :	Crystallization behavior of long-chain branching polylactide
Type de document :	texte imprimé
Auteurs :	Jianye Liu, Auteur ; Shijun Zhang, Auteur ; Liying Zhang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13670–13679
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Crystallization Polylactide
Résumé :	The crystallization behavior of long-chain branched (LCB) poly(l-lactide) (PLLA), which were successfully prepared by successive functional group reactions, was studied by nonisothermal and isothermal methods in a wide temperature range. The density of the nuclei for LCB samples during crystallization was much higher than that for linear PLLA. According to qualitative information about the chain topologies of the branched PLLAs, obtained by a combination of linear viscoelasticity and branch-on-branch (BOB) dynamic modeling, it should be the backbones of LCB that are able to act as nuclei and thus markedly enhance the crystallization rate of PLLA. Moreover, a kinetic analysis of crystallization was performed using secondary nucleation theory.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301567n

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13663-13669

Titre :	Evidence of hydrogen-bond formation during crystallization of cefodizime sodium from induction-time measurements and in situ raman spectroscopy
Type de document :	texte imprimé
Auteurs :	Penglei Cui, Auteur ; Xinwei Zhang, Auteur ; Qiuxiang Yin, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13663-13669
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	In situ Induction Crystallization
Résumé :	In this article, the nudeation process of cefodizime sodium was analyzed from two perspectives: induction time and hydrogen-bond formation. According to classical nucleation theory, the correlation of the induction time indicated that heterogeneous nucleation dominates the nucleation process at lower supersaturation whereas homogeneous nucleation is the main mechanism at higher supersaturation. Then, in situ Raman spectroscopy was used to investigate the probability of hydrogen-bond formation in the supersaturated solution and the nucleation process of cefodizime sodium. A central feature of the hydrogen bonding is that the probability reaches a maximum value at the nucleation point, which can be used to relate the probability of hydrogen-bond formation to the induction time. Furthermore, SEM imaging affords fundamental information to illustrate the effect of supersaturation on the morphology of cefodizime sodium crystals: agglomerated small needlelike particles preferentially formed at a high supersaturation, whereas large needlelike particles formed at low supersaturation.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26508191

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13655-13662

Titre :	Adsorption of aqueous Cr(VI) by novel fibrous adsorbent with amino and quaternary ammonium groups
Type de document :	texte imprimé
Auteurs :	Jing Wang, Auteur ; Liang Zhao, Auteur ; Wenjie Duan, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13655-13662
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Adsorption
Résumé :	A novel fibrous adsorbent functionalized with both amino and quaternary ammonium groups (QAPAN) was prepared through a simple two-step route (i.e., amination followed by quaternization reactions) for removing aqueous Cr(VI) through batch and column experiments. As compared with traditional adsorbents, the QAPAN had an extremely fast adsorption kinetic (equilibrium achieved within 10 min) and an exceptionally high adsorption capacity (Qm = 248 mg/g). The QAPAN worked well even in strong basic conditions, and ionic strength and coexisting anions had minor inhibitory effects on the adsorption. Besides, the QAPAN could be repeatedly used for Cr(VI) adsorption with no obvious decrease of uptake after regeneration with 0.1 mol/L NaOH. By analyzing FTIR and XPS spectra, an electrostatic interaction mechanism between Cr(VI) oxyanions and the surface amino and quaternary ammonium groups was proposed. Findings of the current study provided a novel material and technology for treatment of Cr(VI) contaminated waters.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26508190

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13648-13654

Titre :	A Strategy to functionalize the carbon nanotubes and the nanocomposites based on poly(l-lactide)
Type de document :	texte imprimé
Auteurs :	Yihui Xu, Auteur ; Qifang Li, Auteur ; Da Sun, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13648-13654
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Nanocomposite
Résumé :	A strategy to achieve balanced properties using functionalized carbon nanotubes has been investigated, and its nanocomposite exhibited good performance in mechanical and electrical properties. Polybutyl acrylate (PBA) has been utilized to functionalize multiwalled carbon nanotubes (MWNTs) by in situ atom transfer radical polymerization, resulting in a shell of molecular weight controlled on MWNTs (MWNT-PBA). Poly(L-lactide) (PLLA), which has been pitched on acting as the matrix of the polymers that are compatible with PBA such as poly(methyl methacrylate) (PMMA) and poly(vinylidene fluoride) (PVDF). A series of PLLA/MWNT-PBA nanocomposites were prepared by solution blending. Morphology, mechanical properties, and electrical properties have been tested, and the results showed that the volume electrical resistance of PLLA/ MWNT-PBA nanocomposites decreased by 10 orders of magnitude as the content of MWNTs arrived at its percolation threshold, which is just 1.51 wt %, while the elastic modulus had increased 94.7%, compared to neat PLLA when the content of MWNTs is 2.98 wt %. Optical microscope images exhibited the spherulite morphologies of the nanocomposites while differential scanning calorimetry (DSC) measures showed that the temperature of cold crystallization increased when the content of MWNT-PBA increased.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26508189

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13639-13647

Titre :	Visible-light-induced photocatalyst based on cobalt-doped zinc ferrite nanocrystals
Type de document :	texte imprimé
Auteurs :	Guoli Fan, Auteur ; Ji Tong, Auteur ; Feng, Li, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13639-13647
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Nanocrystal Photocatalysis Catalyst Visible radiation
Résumé :	The present work reported the synthesis of visible-light-induced cobalt-doped zinc ferrite (Zn1-xCoxFe2O4) photocatalysts via a facile reduction―oxidation route, which involved rapid reduction of Fe3+ and Co2+ cations in colloid mill reactor, followed by oxidation of iron and cobalt nuclei and structural transformation under hydrothermal conditions. The structural and optical properties of materials were characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray photoelectron spectroscopy (XPS), and UV―vis diffuse reflectance spectra. The results indicated that metallic Co and Fe nuclei could be obtained by reduction in the colloid mill, and Zn1-xCoxFe2O4 nanocrystals with uniform size were successfully achieved. Furthermore, compared to ZnFe2O4, Zn1-xCoxFe2O4 samples (x = 0.03, 0.1, 0.2) exhibited enhanced photocatalytic activity in the degradation of methylene blue under visible light irradiation. Especially, the Zn0.8Co0.2Fe2O4 sample had the highest photocatalytic activity, which was mainly attributable to its smaller band edge. Since as-synthesized Zn-Co ferrites nanocrystals have the advantages of intrinsic chemical stability and magnetic property, it can be expected that they may have potential application in the field of industrial photodegradation of organic pollutants.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26508188

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13632–13638

Titre :	Decolorization of orange II in aqueous solution by an Fe(II)/sulfite system : Replacement of persulfate
Type de document :	texte imprimé
Auteurs :	Long Chen, Auteur ; Xinzi Peng, Auteur ; Jihao Liu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13632–13638
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Aqueous solution sulfite system
Résumé :	A novel process for decolorizing dyes with sulfate radicals (SO4•–) using an Fe(II)/sulfite system is reported in this manuscript. The objective of this study was to investigate the conditions under which Fe(II) activates Na2SO3 to produce SO4•– and decolorize organic dyes. Orange II, Rhodamine B, Indigo Carmine, and Reactive Brilliant Blue X-BR could be efficiently decolorized using this novel system, which was compared with the Fe(II)/persulfate and Fenton (Fe(II)/H2O2) systems. The Fe(II)/sulfite system surpassed the other two in the decolorization of these dyes, and detailed mechanisms of the Fe(II)/sulfite system were researched. Primary radical identification through quenching experiments using tert-butyl alcohol and ethanol confirmed the existence of SO4•–, HO•, and SO5•–. A kinetic model was established for the halide ion effect, and kI–,SO4•– (3.2 × 1011 mol–1 L s–1) and RSO4•–f (10–4–10–3 mol L–1 s–1) were indirectly derived. In conclusion, the Fe(II)/sulfite system is a good candidate for use in detoxifying water contaminants.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3020389

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13627-13631

Titre :	A Novel application of methanesulfonic acid as catalyst for the alkylation of olefins with aromatics
Type de document :	texte imprimé
Auteurs :	Ying Tian, Auteur ; Xuan Meng, Auteur ; Ji-yun Duan, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13627-13631
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Alkylation Catalyst
Résumé :	Methanesulfonic acid (MSA) was used as the catalyst to remove trace olefins from aromatics (referred to as oil). The reactions were conducted in a round-bottom flask equipped with a reflux condenser and oil-bath under atmospheric pressure. The influences of the reaction temperature, the mass ratio of MSA to oil, and the reaction time were investigated. The experimental results showed that after a 40 min reaction time at 413 K, the olefins conversion of 89.45% was obtained with a mass ratio of MSA to oil of 6%. The catalyst was reused five times without a reactivation treatment, and the olefins conversion reached 66.02% the fifth time. More importantly, the catalytic mechanism was also proposed in this work. In addition, as MSA is biodegradable, this method represents an environmentally benign route to remove trace olefins from aromatics.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26508186

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13619-13626

Titre :	A New mathematical model study on CO2 gasification reaction of typical agricultural residues
Type de document :	texte imprimé
Auteurs :	Hua Fei, Auteur ; Song Hu, Auteur ; Faen Shi, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13619-13626
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Gasification Carbon dioxide Mathematical model
Résumé :	In this context, the differential mass conservation equations were used to describe typical noncatalytic gas-solid reactions, such as biomass chars gasification, and an approximate method was applied to solve these equations. The methodology developed in this work was based on an approximate method for decoupling the gas conservation equation. With this strategy, the calculation of gas concentration and solid conversion at any time and position during reaction could be converted to the solution of two coupled algebraic equations. Thereby, a new mathematical model, modified quantize model (MQM), was constructed to describe the gasification rates of biomass chars according to a nonlinear relationship between the porosity and reaction surface of biomass chars when pore diffusion effect is considered. Carbon conversion rates predicted by the MQM were in closer agreement with the experimental data than those predicted by the Rafsanjani model (QM) and discrete random pore model (DRPM). Using the MQM, the gasification process of biomass chars in CO2 at different temperatures was analyzed.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26508185

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13609–13618

Titre :	Chemical and molecular descriptors for the reactivity of amines with CO2
Type de document :	texte imprimé
Auteurs :	Anita S. Lee, Auteur ; John R. Kitchin, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13609–13618
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Reactivity amines
Résumé :	Amine-based solvents are likely to play an important role in CO2 capture applications in the future, and the identification of amines with superior performance will facilitate their use in CO2 capture. While some improvements in performance will be achieved through process modifications, modifying the CO2 capture performance of an amine also implies in part an ability to modify the reactions between the amine and CO2 through development of new functionalized amines. We present a computational study of trends in the reactions between CO2 and functionalized amines with a focus on identifying molecular descriptors that determine trends in reactivity. We examine the formation of bicarbonate and carbamate species on three classes of functionalized amines: alkylamines, alkanolamines, and fluorinated alkylamines including primary, secondary, and tertiary amines in each class. These functional groups span electron-withdrawing to donating behavior, hydrogen-bonding, extent of functionalization, and proximity effects of the functional groups. Electron withdrawing groups tend to destabilize CO2 reaction products, whereas electron-donating groups tend to stabilize CO2 reaction products. Hydrogen bonding stabilizes CO2 reaction products. Electronic structure descriptors based on electronegativity were found to describe trends in the bicarbonate formation energy. A chemical correlation was observed between the carbamate formation energy and the carbamic acid formation energy. The local softness on the reacting N in the amine was found to partially explain trends of carbamic acid formation energy.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301419q

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13599-13608

Titre :	Efficiency evaluation of different TiO2 coatings on the photocatalytic inactivation of airborne bacterial spores
Type de document :	texte imprimé
Auteurs :	Silvia M. Zacarias, Auteur ; Maria L. Satuf, Auteur ; Maria C. Vaccari, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13599-13608
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Metabolic inactivation Photocatalysis Titanium oxide
Résumé :	The performance of different TiO2 coatings is compared for the photocatalytic inactivation of dry Bacillus subtilis spores dispersed on TiO2 films under UV-A radiation. Three different TiO2 coatings were assayed: Degussa P-2S, sol-gel, and composite sol―gel/Degussa P-25. The influence of the increase in the number of TiO2 layers was also studied. Furthermore, the amount of TiO2 deposited on the borosilicate glass plates and the fraction of energy effectively absorbed by the catalytic films were determined. Spectral diffuse transmittance and reflectance measurements were performed using a spectroradiometer with an integrating-sphere attachment. The net-radiation method was then applied to evaluate the fraction of energy absorbed by the coatings. To objectively compare the performance of the catalytic films, two types of efficiencies were calculated: the photonic efficiency and the quantum efficiency of inactivation. The highest quantum efficiency was obtained with the TiO2 Degussa P-2S coating with two layers.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26508183

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13589-13598

Titre :	Coupling conversion of methanol and C4 hydrocarbon to propylene on la-modified HZSM-5 zeolite catalysts
Type de document :	texte imprimé
Auteurs :	Ting Gong, Auteur ; Xin Zhang, Auteur ; Ting Bai, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13589-13598
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Catalyst Zeolite
Résumé :	The coupling conversion of methanol and C4 hydrocarbon (62.2 wt % of n-butanes and 34.4 wt % of n-butylenes) to propylene was studied over La-modified HZSM-5 (La/HZSM-5) catalysts. Compared with the individual methanol to olefins and C4 hydrocarbon cracking to propylene, the coupling conversion remarkably improved propylene yield and the catalytic stability of La/HZSM-5. In the coupling conversion, propylene yield was strongly dependent on the reaction conditions and the loading of La. The interaction of La with hydroxyl groups (OH) adsorbed on HZSM-5 surface occurred. Such interaction modified the density and distribution of acid sites from the hydroxyl groups. Propylene yield was close relative to the density and distribution of acid sites. The comparatively high propylene yield of ca. 46.0 wt % was obtained on La/HZSM-5 catalyst with 1.5 wt % load of La (1.5 wt % La/HZSM-5), possibly due to the moderate density and distribution of acid sites on the catalyst.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26508182

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13580-13588

Titre :	The Pore structure variation of coal char during pyrolysis and its relationship with char combustion reactivity
Type de document :	texte imprimé
Auteurs :	Dong-Wook Lee, Auteur ; Jong-Soo Bae, Auteur ; Se Joon Park, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13580-13588
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Chemical reactivity Combustion Pyrolysis Coal Pore structure
Résumé :	We investigated the pore-structure variation of coal char during the devolatilization process of Baganuur coal (BC) and Shievee Ovoo coal (SOC) from Mongolia, and reported the relationship between the char pore structure and its combustion reactivity. SOC char showed much higher combustion reactivity than BC char at real-power-plant temperatures (1100-1400 °C) as well as at the low temperature range below 900 °C. Meanwhile, the surface area of the SOC char was much higher than that of the BC char, and it was confirmed that their surface areas were dominantly derived from their ash pore structure. In addition, the ash phase dispersion of the SOC char was better than that of the BC char. Thus, it was concluded that the higher surface area and better dispersion of ash phase leads to a higher combustion reactivity of the SOC char.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26508181

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13574–13579

Titre :	Analysis of external and internal mass transfer at low reynolds numbers in a multiple-slit packed bed microstructured reactor for synthesis of methanol from syngas
Type de document :	texte imprimé
Auteurs :	Hamidreza Bakhtiary-Davijany, Auteur ; Farbod Dadgar, Auteur ; Fatemeh Hayer, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13574–13579
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Synthesis gas Reactor Packed bed Low Reynolds number Mass transfer
Résumé :	The possibility of mass transfer limitations in an integrated micro packed bed reactor-heat exchanger (IMPBRHE) for methanol synthesis was experimentally investigated. Experiments were performed with three different particle size distributions (50-200 μm) of a Cu-based catalyst at 80 bar and 215-270 °C. Negligible effects of pore diffusion limitations on the performance of the reactor under methanol synthesis conditions for catalyst particle diameters up to 125 μm were found. Due to a very low Reynolds numbers (∼1) and dominance of molecular diffusion, variation of the total pressure was applied as a suitable technique to alter the diffusivities of reactants in the gas mixture by dilution, while keeping the reactant flow and partial pressure constant. No significant change in the CO conversion was observed in the temperature range 235―255 °C, pressure range 50-90 bar, and for reactant contact times of 105-308 ms·g/mL. The same procedure was applied to a laboratory fixed bed reactor with similar results. Possible heat transfer effects associated with the dilution were shown to be negligible. We therefore conclude that both reactor systems operate in the absence of external mass transfer limitations.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26508180

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13562-13573

Titre :	A Graphical method of improving the production rate from batch reactors
Type de document :	texte imprimé
Auteurs :	David Ming, Auteur ; Diane Hildebrandt, Auteur ; David Glasser, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13562-13573
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Reactor Batchwise Production
Résumé :	In this work, a graphical method of identifying opportunities for improving the production rate from batch reactors is presented. On the basis of this approach, a modification to the standard procedure of batch operation is also developed. It is found that by modifying the initial concentration of the batch, overall production performance may be improved. This may be achieved in practice by retaining a fraction of the final product volume and mixing with fresh feed material for the next batch cycle. This result is counterintuitive to the normal method of batch operation. Arguments demonstrating how the graphical method may be used to gain insight into alternative methods of operation are also briefly discussed. As such, the bypassing of feed may also be used to improve production rate for exit concentrations not associated with the optimal concentration. The graphical approach also allows optimization of batches where only experimental data are given. The method is demonstrated through several industrial examples and is successfully shown to improve over the standard method of batch operation.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26508179

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13552-13561

Titre :	Preparation of some useful compounds of zirconium from bangladeshi zircon
Type de document :	texte imprimé
Auteurs :	Ranjit K. Biswas, Auteur ; Mohammad A. Habib, Auteur ; Aneek K. Karmakar, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13552-13561
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Zirconium
Résumé :	A number of useful zirconium compounds, such as hydrated zirconyl chloride, hydrated zirconium sulfate, zirconium dioxide, γ-zirconium ammonium phosphate, γ-zirconium phosphate, γ-zirconium phosphate phosphite, and γ-zirconium phosphate hypophosphite have been prepared from Bangladeshi zircon following the NaOH-fusion, acid (HCl and H2SO4)-leaching, precipitation, calcination/pyrolysis, condensation polymerization, ion exchange and the tap tactic reaction methods. The products have been characterized by chemical and thermogravimetric analyses in all cases, together with the XRD patterns and sodium exchange capacities in some cases.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301412b

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 42 (Octobre 2012) . - pp. 13545-13551

Titre :	Hydrothermal hydrolysis of hesperidin into more valuable compounds under supercritical carbon dioxide condition
Type de document :	texte imprimé
Auteurs :	Duangkamol Ruen-ngam, Auteur ; Armando T. Quitain, Auteur ; Mitsuru Sasaki, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13545-13551
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Supercritical state Carbon dioxide Hydrolysis
Résumé :	Synergistic effects of utilizing subcritical water and supercritical carbon dioxide were investigated for the hydrolysis of hesperidin into more valuable compounds at a pressure range of 10―25 MPa and temperature of 110―140 °C. The effect of operating conditions such as pressure, temperature, reaction time, and addition of cosolvent such as ethanol were found to affect the hydrolysis rate. Higher yields were obtained at higher carbon dioxide pressure owing to an increase in formation of carbonic acid. Moreover, the rate of reaction was also found to increase with increasing temperature, obtaining higher yields of the main products, hesperetin-β-glucoside and hesperetin. Addition of ethanol as a cosolvent could increase solubility of hesperidin, however, it inhibited the reaction and formation of carbonic acid. At the maximum temperature of 140 °C and pressure of 25 MPa investigated in this work, the highest concentration of hesperetin-β-glucoside of 4.2 mol/L was obtained in a reaction time of 2 h, whereas for hesperetin the highest was 6.9 mol/L obtained in 3 h. Among the hydrolysis methods investigated, the proposed method was the most selective toward formation of the target compounds.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26508177

Industrial & engineering chemistry research / Paul, Donald R. . Vol. 51 N° 42

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