Catalogue en ligne Bibliothèque Ecole Nationale Polytechnique d'Alger

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13585–13588

Titre :	Synthesis of Cd hydroxide particles with hollow structures by a one - step process
Type de document :	texte imprimé
Auteurs :	Ying Tian, Auteur ; Xin Cui, Auteur ; Fangming Jin, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13585–13588
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Hydroxide
Résumé :	Cd4Cl3(OH)5 particles, for use as a CdS photocatalyst precursor with hollow morphology, were successfully synthesized at room temperature via a one-step process, using boric acid or sodium borate as a buffer. The identification of the morphology and characterization of synthesized particles by high-resolution transmission electron microscopy coupled with energy-dispersive X-ray analysis (HR-TEM/EDX) and X-ray diffraction (XRD) revealed that Cd4Cl3(OH)5 was the main compound. with a size of 40–100 nm, and boron was mostly concentrated on the shell covering nanosized Cd4Cl3(OH)5 particles. Compared with the traditional synthetic methods, this approach has benefits of direct, easy synthesis without the need for additional treatment. It is suggested that boron should play an important role in the synthesis of hollow morphology.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201518t

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13576-13584

Titre :	A new quartic equation of state based on a general form and its application to pure fluids
Type de document :	texte imprimé
Auteurs :	Daxue Li, Auteur ; Jingjing Cao, Auteur ; Zhi Yun, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13576-13584
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Thermodynamic properties Equations of state
Résumé :	A new quartic equation of state (EOS) based on a general form is proposed. Parameters in the new equation are regressed as substance-specific constants for 88 pure substances. The calculated saturated properties for nonpolar and polar substances are compared with experimental data and with that obtained by the Peng―Robinson Stryjek―Vera (PRSV), Patel―Teja (PT), and Yun EOSs for the various pure substances. Despite its simplicity, the proposed equation has good predictive capability over the entire temperature region.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267517

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13568–13575

Titre :	On the influencing factors and strengthening mechanism for thermal conductivity of nanofluids by molecular dynamics simulation
Type de document :	texte imprimé
Auteurs :	Wenzheng Cui, Auteur ; Minli Bai, Auteur ; Jizu Lv, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13568–13575
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Nanofluids Dynamics simulation
Résumé :	Compared with conventional single-phase working fluids, nanofluids possess significantly increased thermal conducting properties, but the mechanism for the increase still lacks perfect theory to explain. The aim of this study was to investigate effects of various influencing factors and determine the strengthening mechanism for thermal conductivity of nanofluids by Molecular Dynamics simulations. Thermal conductivities of nanofluids containing nanoparticles with different materials, volume concentrations, and shapes were calculated based on the Green–Kubo formula. Besides, Radical Distribution Function was first applied to nanofluids to analyze the microstructure. In addition, micromotions of nanoparticles were investigated thoroughly by statistical analysis. It was found for the first time that the effects of influencing factors for thermal conductivity of nanofluids can be explained and forecasted by comparing the proportion of energetic atoms containing in different nanoparticles. The changed microstructure of nanofluids is a newly discovered mechanism, and combined with the micromotions of nanoparticles they are proposed to be the main mechanism for strengthening thermal conductivity of nanofluids. The present work indicates that analyzing the proportion of energetic atoms can be an effective way for predicting thermal conducting properties of nanofluids and suggests the main mechanism for thermal conductivity increase which is the basis of developing new heat transfer theory for nanofluids.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201307w

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13561-1356

Titre :	Thermodynamic preparation window of alpha calcium sulfate hemihydrate from calcium sulfate dihydrate in non - electrolyte glycerol – water solution under mild conditions
Type de document :	texte imprimé
Auteurs :	Baohong Guan, Auteur ; Guangming Jiang, Auteur ; Hailu Fu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13561-1356
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Electrolyte Preparation
Résumé :	Through vapor pressure measurements, water activities of the glycerol-water solution were first examined under temperatures of 30―85 °C and glycerol concentrations of 0―50 mol %. The water activity is the only determinant of phase-transition point among CaSO4·2H2O (DH), α-CaSO4·0.5H2O (α-HH), and CaSO4 (AH) in glycerol-water solution. Accordingly, a phase-transition diagram was constructed as a function of temperature (0―140 °C) and glycerol concentration (0―50 mol %), which provided a thermodynamic preparation window of α-HH from DH. Controlling glycerol concentration and temperature within the window, direct transition of DH to α-HH can be regnlated. However, the window is apt to shrink as the operating time is shortened, indicating that its available profile is directed by transition kinetics ofDH to α-HH besides transition thermodynamics. Overall, the glycerol―water solution could act as a novel category of nonelectrolyte medium for α-HH preparation from DH.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267515

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13554-13560

Titre :	New correlation for mass transfer characteristics of spray column
Type de document :	texte imprimé
Auteurs :	Tsubsa Tanda, Auteur ; Koichi Shirai, Auteur ; Yukihiko Matsumura, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13554-13560
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Spray tower Mass transfer Correlation analysis Correlation
Résumé :	This paper presents a study of the mass transfer characteristics of a spray column being used as a dehumidification device for air. The experiment was conducted using high humidity air and polyethylene glycol (PEG) as a desiccant solution over a range of process conditions including various liquid flow rates, gas flow rates, water concentrations of PEG, temperatures of PEG, and nozzle diameters. The performance of the spray column was evaluated in terms of volumetric mass transfer coefficients. The results were well expressed by the correlation using dimensionless groups including the physical properties of the liquid and nozzle diameter.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267514

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13545-13553

Titre :	Experimental investigation on the performances on the shell side of shell - and - tube heat exchangers with multiparallel channels
Type de document :	texte imprimé
Auteurs :	Wen-Liang Zeng, Auteur ; Zheng-Guo Zhang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13545-13553
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Heat exchanger
Résumé :	This paper presents an experimental investigation on the local surface heat-transfer coefficient on the shell side of a longitudinal-flow shell-and-tube heat exchanger with a multiparallel channel (MPC) inlet and outlet. Under the conditions of with or without a fluid flow distributor (FDB) in the inlet region of the heat exchanger, some characteristics (such as the local Nussult number (Nu) distribution, local-mean Nu distribution, overall heat-transfer performance, and pressure drop) were investigated. The investigation results reveal the distribution of the local surface Nu value in the inlet region, and they give a reasonable mechanism analysis. It was suggested that not only the uniformity of both the fluid flow and the local Nu distribution was effectively improved by FDBs, but also that the global heat-transfer surface Nu value of the heat exchanger was enhanced by more than 10% with the pressure drop increasing slightly by FDBs.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267513

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13538-13544

Titre :	On the subgrid behavior of accelerated riser flows for a high stokes number particulate
Type de document :	texte imprimé
Auteurs :	Christian C. Milioli, Auteur ; Fernando E. Milioli, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13538-13544
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Riser
Résumé :	We carried out two-fluid highly resolved subgid simulations (SGS) to investigate the effective hydrodynamics of solid phases in riser flows. We considered a high Stokes number articulate, solid hold-ups and gas velocities typical of circulating Fluidized bed combustors and gasifiers (CFBC-G), namely a 520 μm size and 2620 kg/m3 density particulate, average solid fractions from 0.015 to 0.09, and gas velocities from about 3 to 9 m/s. Periodic boundaries were applied in the gravitational direction with the flow driving force provided by an additional gas phase pressure gradient chosen to exceed the gravity acting on the local gas-solid mixture. As a consequence, the simulations produced transient accelerated flows, giving rise to instantaneous field predictions and volume averaged effective parameters at growing gas velocities. The results showed significant effects of both gas velocity and solid bold-up over the flow topology, over the effective stresses and pressure of the solid phase, and over the effective drag. A reasonable agreement was found with a few empirical data that were available for effective shear stresses and effective drag.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267512

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13526–13537

Titre :	Natural nontoxic solvents for recovery of picolinic acid by reactive extraction
Type de document :	texte imprimé
Auteurs :	Mangesh D. Waghmare, Auteur ; Kailas L. Wasewar, Auteur ; Shriram S. Sonawane, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13526–13537
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Nontoxic solvents
Résumé :	Pyridine carboxylic acids and their derivatives are attracting considerable attention for their presence in many natural products. 2-Pyridinecarboxylic acid, also known as picolinic acid is widely used in the pharmaceutical industries. Compared to chemical methods, enzymatic oxidation of 3-hydroxyanthranillic acid is an advantageous alternative for the production of picolinic acid. Reactive extraction is a promising method to recover carboxylic acid but suffers from toxicity problems of the diluent and extractant employed, therefore there is a need for a nontoxic extractant and diluent or a combination of less toxic extractants in a nontoxic diluent that can recover acid efficiently. The present paper focuses on the reactive extraction of picolinic acid using tri-n-butyl phosphate (TBP) in sunflower oil and castor oil. Results were presented in terms of distribution coefficients (0.0066 to 0.664 for sunflower oil and 0.0099 to 0.94 for castor oil), loading ratio (<0.5), degree of extraction (0.65 to 42.9% for sunflower oil and 0.9 to 74.6% for castor oil), and equilibrium complexation constants. Relative basicity, mass action law, and Langmuir models were used to represent the reactive extraction equilibrium for picolinic acid–TBP–diluent. Model results are close to experimental results.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201228u

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13518–13525

Titre :	Equilibrium and kinetic studies on reactive extraction of pyruvic acid with trioctylamine in 1 - octanol
Type de document :	texte imprimé
Auteurs :	Mustafa E. Marti, Auteur ; Turker Gurkan, Auteur ; L. K. Doraiswamy, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13518–13525
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Kinetic
Résumé :	Interest in pyruvic acid has been growing due to the increase in its potential areas of use and its importance in metabolic reactions. These reasons along with the limitations on recovery have prompted researchers to consider novel recovery techniques. Reactive extraction has been proposed as a promising approach to the recovery of carboxylic acids. In this study, equilibrium and kinetic data were obtained for reactive extraction of pyruvic acid using trioctylamine (TOA) or Alamine 336 in 1-octanol or oleyl alcohol. The results showed that, without pH adjustment in the aqueous phase, and without the use of an extractant, 1-octanol extracted more pyruvic acid than oleyl alcohol with a distribution coefficient (KD) of 0.30. This trend remained the same when tertiary amines were used as an extractant. The KD values did not significantly differ with TOA or Alamine 336. The recovery of pyruvic acid was observed to increase as a function of TOA concentration and the stoichiometry of the reaction was mainly 1:1. As tertiary amines react only with undissociated acids, an increase in the initial pH of the aqueous phase lowered the KD values. When the pH was 4.0, the effect of TOA concentration on pyruvic acid extraction disappeared and for all concentration levels a distribution coefficient of 0.10 was obtained. Kinetic measurements showed that the reaction between pyruvic acid and TOA in 1-octanol is first order with respect to the two reactants with a rate constant of 0.94 L mol–1 s–1. The enhancement factor was calculated as 25.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie200625q

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13508–13517

Titre :	CO2 - Tolerant oxygen - permeable Fe2O3 - Ce0.9Gd0.1O2 - δ dual phase membranes
Type de document :	texte imprimé
Auteurs :	Huixia Luo, Auteur ; Heqing Jiang, Auteur ; Konstantin Efimov, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13508–13517
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Phase membranes Oxygen permeable
Résumé :	CO2-stable oxygen-permeable Fe2O3 (FO) - Ce0.9Gd0.1O2-δ (CGO) dual phase composite membranes of the composition χ wt % FO - (100 – χ) wt % CGO with χ = 25, 40, 50 were successfully prepared via a one-pot single-step method. X-ray diffraction (XRD) demonstrated that all FO - CGO composite membranes after sintering at 1300 °C for 5 h represent a microscale mixture of only the two pure phases FO and CGO. Scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDXS), and oxygen permeation revealed that the microstructure of the composition of the χ FO - (100 – χ) CGO dual phase membranes has a great influence on the oxygen permeability including its time-dependence. It was found that the composition of 40FO - 60CGO displays the highest oxygen permeability. An oxygen permeation flux of 0.18 mL/min·cm2 was obtained through the uncoated 40FO - 60CGO membrane with a thickness of 0.5 mm under an air/He oxygen gradient at 1000 °C. In situ XRD demonstrates that the 40FO - 60CGO material possesses a good phase stability not only in an atmosphere of 50 vol % CO2/50 vol % Ar but also in other atmospheres with a low oxygen partial pressure like reduced pressure (vacuum) and 5 vol % H2/95 vol % He. After coating the 40FO - 60CGO dual phase membrane with a porous La0.6Sr0.4CoO3-δ (LSC) layer of a few μm thicknesses on the air side, the oxygen permeation flux reaches the steady state immediately. This steady oxygen permeation flux of the LSC coated membrane was found to be 0.20 mL/min·cm2 unchanged for more than 150 h even when pure CO2 was used as the sweep gas, which indicates that the coated 40FO - 60CGO dual phase membrane is CO2 stable.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie200517t

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13500–13507

Titre :	A GA - based neural fuzzy system for modeling a paper mill wastewater treatment process
Type de document :	texte imprimé
Auteurs :	Mingzhi Huang, Auteur ; Jinquan Wan, Auteur ; Yongwen Ma, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13500–13507
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Neural fuzzy system Wastewater treatment
Résumé :	A genetic algorithm-based neural fuzzy system (GA-NFS) was presented for studying the coagulation process of wastewater treatment in a paper mill. In order to adapt the system to a variety of operating conditions and acquire a more flexible learning ability, the GA-NFS was employed to model the nonlinear relationships between the effluent concentration of pollutants and the chemical dosages, and a hybrid learning algorithm divided into two stages was proposed for parameters learning. During the first learning stage, a genetic algorithm was used to optimize the structure of GA-NFS and the membership function of each fuzzy term due to its capability of parallel and global search. On the basis of an optimized training stage, the back-propagation algorithm (BP algorithm) was chosen to update the parameters of GA-NFS to improve the system precision. The GA-NFS proves to be very effective in modeling coagulation perform and performs better than adaptive-network-based fuzzy inference system (ANFIS). RMSE, MAPE, and R between the predicted and observed values for GA-NFS were only 0.01099, 2.3337, and 0.9375, respectively.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201296p

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13485–13499

Titre :	Process optimization of FT - diesel production from lignocellulosic switchgrass
Type de document :	texte imprimé
Auteurs :	Mariano Martin, Auteur ; Ignacio E. Grossmann, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13485–13499
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Optimization Lignocellulosic
Résumé :	In this paper, we present the conceptual design for the optimization of FT-diesel production process from switchgrass via gasification of biomass. We propose a limited superstructure where the process starts with the gasification of the biomass. Two different alternatives are evaluated, direct and indirect gasification. The gas obtained is cleaned up and its composition adjusted in terms of the ratio CO/H2 considering a bypass, a PSA system and water gas shift reaction. Next, the removal of CO2 and H2S is performed using absorption in monoethanolamines and PSA. Once the syngas is prepared, the Fischer-Tropsch reaction is conducted and the products separated. Hydrocracking of the heavy products is also considered to increase the yield toward green diesel. The optimization of the system is formulated as an equation-based Mixed-Integer Nonlinear Programming (MINLP) problem that is solved for the optimal production of the biodiesel fraction while minimizing the energy consumption and the hydrogen consumption. The optimal solution requires the use of indirect gasification followed by steam reforming. The ratio of CO/H2 is left unchanged as the one obtained after gas reforming, while adjusting the temperature at the FT reactor and the operating conditions of the hydrocracking to increase the FT-diesel production. A promising production cost of 0.71 $/gallon is obtained, and only 0.15 gal Water/gal bioifuel of water consumption is required if air cooling is implemented in the plant.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201261t

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13475–13484

Titre :	Production of B - carotene nanoparticles by the solution enhanced dispersion with enhanced mass transfer by ultrasound in supercritical CO2 (SEDS - EM)
Type de document :	texte imprimé
Auteurs :	He Yang Jin, Auteur ; Melinda Hemingway, Auteur ; Fei Xia, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13475–13484
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Résumé :	In recent years, the solution enhanced dispersion in supercritical fluids (SEDS) technique is widely applied to produce fine and small particles of drugs and other active ingredients. However, this technique still cannot be used to generate particles in the submicrometer range for specific compounds, such as carotenoids. In this study, a modified SEDS technique is explored and applied in the preparation of β-carotene nanoparticles with relatively narrow size distribution. This novel technique, termed SEDS-EM, combines a traditional SEDS technique with ultrasonication from the supercritical antisolvent with enhanced mass transfer precipitation technique (SAS-EM). For this new technique, the β-carotene solution is premixed with the antisolvent (supercritical CO2) in a coaxial nozzle; then the mixed solution is sprayed from the coaxial nozzle onto a surface vibrating at an ultrasonic frequency. The solution jet is dispersed by the coaxial nozzle and further atomized into very small droplets by the ultrasonic vibrating surface. This combination of a coaxial nozzle and the ultrasound field enhances the mass transfer between the solution and the antisolvent. The resultant β-carotene particles decreased in size from the micrometer range (2–5 μm) by SEDS to the nanometer range (20–205 nm) by SEDS-EM. This smaller particle size can be controlled by the power supplied from the attached ultrasound transducer utilized in SEDS-EM. The size and morphology of the particles are observed by scanning electron microscopy (SEM) and transmission electron microscopy (TEM). The effects of the process parameters on the β-carotene yield are discussed. The crystallography transformation of the processed and unprocessed β-carotene is characterized by XRD and FTIR. The particle precipitation in sub and near critical regions of the DCM-CO2 binary system is also discussed.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie2011565

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13466-13474

Titre :	Evaluation tool for the environmental design of chemical processes
Type de document :	texte imprimé
Auteurs :	Carmen M. Torres, Auteur ; Mamdouh A. Gadalla, Auteur ; Josep M. Mateo-Sanz, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13466-13474
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Design
Résumé :	Since the environmental awareness increases and regulations become more restrictive, chemical industries are forced to adopt measures for minimizing the environmental impact and to include these techniques in the process design. This work proposes a methodology where environment and human health considerations are coupled with the process design of new and existing plants. With this aim, a new assessment tool for the environmental evaluation of chemical processes is presented. It includes the development of a new environmental indicator (Material Balance Environmental Index, MBEl) based on the toxicities of the chemicals involved and the materials flows between the process and environment. Moreover, a total index is computed following three levels of aggregation using the geometric mean of the ratios of several environmental impact categories. The environmental evaluation tool is tested using two case studies (formaldehyde and styrene production), where data are obtained from rigorous process simulation validated with industrial data.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267505

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13457–13465

Titre :	Subspace - modeling - based nonlinear measurement for process design
Type de document :	texte imprimé
Auteurs :	XinJiang Lu, Auteur ; MingHui Huang, Auteur ; YiBo Li, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13457–13465
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Nonlinear processes
Résumé :	In industry, many nonlinear processes can be approximated well by a linear model under a suitable design parameter, upon which a linear controller can effectively control these processes. The key problem is how to find this suitable design parameter, which is never considered in process design. In this paper, a novel design for control approach is proposed to design the process to have a satisfactory linear approximation. First, a subspace-modeling-based nonlinear measurement is proposed to avoid the infinite dimensional optimization problem in the traditional nonlinearity measurement. Then a particle-swarm-optimization-based design approach is developed to obtain the optimal design parameter through solving the nonconvex and nondifferential measurement problem. Finally, the proposed design is applied to design a practical curing oven and compared with the existing design.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie2008554

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13444-13456

Titre :	A superstructure optimization approach for membrane separation - based water regeneration network synthesis with detailed nonlinear mechanistic reverse osmosis model
Type de document :	texte imprimé
Auteurs :	Cheng Seong Khor, Auteur ; Dominic C. Y. Foo, Auteur ; Mahmoud M. El-Halwagi, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13444-13456
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Modeling Reverse osmosis Membrane separation Optimization Superstructure
Résumé :	Scarcity of freshwater resources and increasingly stringent environmental regulations on industrial effluents have motivated the process industry to identify and develop various water recovery strategies. This work proposes the use of detailed model representation for water regeneration network synthesis, in which nonlinear mechanistic models of the regeneration units are embedded within an overall mixed-integer nonlinear programming (MINLP) optimization framework. The superstructure-based MINLP framework involves both continuous variables for water flow rates and contaminant concentrations and 0―1 variables for selection ofpiping interconnections. The nonlinear regeneration model produces a rigorous cost-based relation, instead of a "black box" model, that is incorporated within the overall MINLP representing a network of numerous water sources and water sinks. Hence, such an approach enables a simultaneous evaluation of both direct water reuse/recycle and regeneration-reuse/recycle opportunities. To demonstrate the proposed approach, an industrial case study is illustrated that incorporates a mechanistic model of reverse osmosis network (RON) for water regeneration for an operating refinery in Malaysia. The results indicate a potential of 58% savings in freshwater use. The capital investment for the water regeneration network is reported as $8,960,000 with a payback period of 2.1 years, thus providing economic support to pursue the RON retrofit option.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267503

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13435-13443

Titre :	Two - stage stochastic programming model for planning CO2 utilization and disposal infrastructure considering the uncertainty in the CO2 emission
Type de document :	texte imprimé
Auteurs :	Jee-Hoon Han, Auteur ; In-Beum Lee, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13435-13443
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Mathematical programming Uncertainty Carbon dioxide Planning Modeling Stochastic programming
Résumé :	Numerous research works have been undertaken to plan carbon capture and storage (CCS) infrastructures for CO2 utilization and disposal. CO2 emissions are difficult to estimate precisely, because CO2 is emitted from various sources at varying rates. In this study, a two-stage stochastic programming model is developed for planning CCS infrastructure including CO2 utilization and disposal under stochastic CO2 emissions. The proposed model considers uncertainties in the variation of CO2 emissions. It can help determine where and how much CO2 to capture, store, transport, utilize, or sequester for the purpose of maximizing the total profit of handling uncertain CO2 emissions while meeting the CO2 mitigation target. The capability of the proposed model to provide correct decisions despite changing CO2 emissions is tested by applying it to an industrial complex on the eastern coast of Korea in 2020. The results will help to determine planning of, and budgeting for, development of a CCS infrastructure.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267502

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13427–13434

Titre :	Optimal structure of learning - type set - point in various set - point - related indirect ILC algorithms
Type de document :	texte imprimé
Auteurs :	Youqing Wang, Auteur ; Jianyong Tuo, Auteur ; Zhong Zhao, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13427–13434
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Optimal
Résumé :	According to the literature statistics, only less than 10% of reported iterative learning control (ILC) methods have been devoted to the indirect approach. Motivated by the full potential of research opportunities in this field, a number of studies on indirect ILC were proposed recently, where ILC-based P-type control and learning-type model predictive control (L-MPC) are two successful stories. All indirect ILC algorithms consist of two loops: an ILC in the outer loop and a local controller in the inner loop. The local controllers are, respectively, a P-type controller in the ILC-based P-type control and a model predictive control (MPC) in the L-MPC. Logically, this leads to the question of what type of ILC should be chosen respectively for the two above-mentioned indirect ILC methods. In this study, P-type ILC and anticipatory P-type (A-P-type) ILC are studied and compared, because they are typical and widely implemented. Based on mathematical analysis and simulation test, it has been proved that the A-P-type ILC should be used in the ILC-based P-type control and while the P-type ILC should be used in the L-MPC. Furthermore, an improved L-MPC with batch-varying learning gain was proposed to handle the trade-off between convergence rate and robustness performance. The simulation results on injection molding process and a nonlinear batch process validated the feasibility and effectiveness of the proposed algorithm.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie200021t

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13419-13426

Titre :	Improvements in petroleum refinery planning : 2. case studies
Type de document :	texte imprimé
Auteurs :	Omar J. Guerra, Auteur ; Galo A. C. Le Roux, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13419-13426
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Planning Refinery Petroleum
Résumé :	This paper is the second part of a series of two papers on the recent advances in petroleum refinery planning. In Part 1 (Guerra and Le Roux, Ind. Eng. Chem. Res. 2011, DOI: 10.1021/ie200303m), nonlinear empirical process models for CDUs and a FCC unit were developed. The implementation of these models in two case studies for petroleum refinery planning is presented in this paper. In the first case, the empirical model for CDUs was implemented in the planning model for a small-scale refinery. In the second case, the empirical models for CDUs and a FCC unit were integrated in the planning model for a medium-scale refinery. In both case studies, empirical process models from the literature were adopted for refinery processes that were not considered in Part 1 of this work. In addition, a comparison of the computational performance for three popular nonlinear programming (NLP) solvers is presented in case study 1. The case studies showed that the empirical models developed in Part 1 of this work are computationally adequate for the petroleum refinery planning.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267500

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp.13403–13418

Titre :	Improvements in petroleum refinery planning : 1. formulation of process models
Type de document :	texte imprimé
Auteurs :	Omar J. Guerra, Auteur ; Galo A. C. Le Roux, Auteur
Année de publication :	2012
Article en page(s) :	pp.13403–13418
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Petroleum Refinery Process models
Résumé :	Optimization of the production planning is crucial for the economic success of a petroleum refinery. Nevertheless, it is a difficult task, because of the large scale of the system and the complexity of the processes involved. Part 1 of this series of two papers addresses the formulation of process models for petroleum refinery planning. First, a generic formulation of nonlinear refinery planning model is adopted from the literature. Subsequently, the formulation of nonlinear empirical models for crude distillation units (CDUs) and a fluid catalytic cracking (FCC) unit is addressed. These empirical models were successfully validated using rigorous process simulators. Finally, the results from model validation showed that the accuracy of model predictions is as good as the current empirical process models reported in the literature, while the empirical process models proposed in this work overcome the limitations of both linear and nonlinear empirical models for CDUs and FCC units previously developed by other authors. Part 2 [Ind. Eng. Chem. Res.2011, DOI: 10.1021/ie200304v] involves the implementation of nonlinear empirical process models in the petroleum refinery planning.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie200303m

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13396–13402

Titre :	Characterization of jack pine early - and iatewood fibers in thermomechanical pulping
Type de document :	texte imprimé
Auteurs :	Fang Huang, Auteur ; Robert Lanouette, Auteur ; Kwei-Nam Law, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13396–13402
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Thermomechanical
Résumé :	The principal objective of this research was to study the morphological changes of Jack pine (Pinus banksiana) earlywood (EW) and latewood (LW) in thermomechanical pulping (TMP). The results indicate that EW fibers tend to separate at the P/S1 interface, whereas LW fibers commonly fail in the regions between the primary wall and the transition layer or outer layer of the secondary wall (P/S1) and between the outer and central layers of the secondary wall (S1/S2). LW fibers exhibit mostly intrawall failure and lower curl and kink indices, whereas EW fibers tend to fail in transwall mode (splitting) and suffer fiber cuttings. In addition, the thin-walled EW fibers show higher collapsibility and conformability than their thick-walled LW counterparts. Moreover, EW fines have higher surface lignin coverage, whereas LW fines have a higher specific volume (SV).
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie2019992

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13387–13395

Titre :	Supercritical carbon dioxide induced foaming of highly oriented isotactic polypropylene
Type de document :	texte imprimé
Auteurs :	Jin-Biao Bao, Auteur ; Tao Liu, Auteur ; Ling Zhao, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13387–13395
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Dioxide Carbon Isotactic Polypropylene
Résumé :	A highly oriented isotactic polypropylene (iPP) with a shish-kebab crystalline structure is used as a template to achieve nanocellular foams by CO2 foaming in the solid state. The shish-kebab crystalline structure is obtained by tuning injection-molding conditions. Nanocells are generated in amorphous domains confined by shish-kebab crystalline domains which cannot foam. The highly oriented iPP consists of both shish-kebab crystalline structure and spherulites structure and is used to investigate the effect of the crystalline morphology on the cell formation at a given CO2 saturation pressure (15 MPa) and various foaming temperatures (135, 140, 143, and 146 °C). When the foaming temperature is 143 °C, a uniform open nanocellular morphology is obtained. The cell size and cell density both increase with foaming temperature from 135 to 143 °C due to the fact that more crystals are molten, providing more space for cell nucleation and growth. However, when the foaming temperature is increased to 146 °C, the cell size abruptly increases from dozens of nanometers to dozens of micrometers, and the corresponding cell density decreases by several orders of magnitude.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie2018228

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp.13380–13386

Titre :	CoAl - CrO4 layered double hydroxides as selective oxidation catalysts at room temperature
Type de document :	texte imprimé
Auteurs :	Jinesh Cherukattu Manayil, Auteur ; Sivashunmugam Sankaranarayanan, Auteur ; Deep Singh Bhadoria, Auteur
Année de publication :	2012
Article en page(s) :	pp.13380–13386
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Hydroxides Oxidation Catalysts
Résumé :	A new combined approach of using layered double hydroxides (LDHs) for both environmental remediation and the derived material as heterogeneous catalyst for selective oxidation is presented. A series of CoAl LDHs with carbonate or nitrate anion in the interlayers was synthesized by two different methods, namely, constant-pH precipitation using NaOH as precipitating agent and homogeneous precipitation by hexamine hydrolysis. The samples were optimized for chromate removal and an uptake of 45 mg Cr/g was obtained for CoAl2-N (CoAl-LDH with Co/Al atomic ratio of 2 and nitrate as interlayer anion by constant-pH precipitation) which was significantly higher than its corresponding carbonate sample that showed 15 mg Cr/g. The thus derived materials after uptake of chromate were explored for solvent free selective oxidation of benzyl alcohol using tert-butyl hydroperoxide as oxidant at room temperature. Among the catalysts screened, CoAl2-N sample after chromate uptake gave 23% conversion with 100% selectivity for benzaldehyde using a catalyst/substrate weight ratio 1:20. The catalyst was recyclable up to four cycles, and the reaction was heterogeneous. The studies revealed that the chromate ion-exchanged sample was more stable and selective as oxidation catalyst than that of surface adsorbed sample. The observed activity of this catalyst was ascribed to the cooperative contribution of Co and Cr.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201436b

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13373-13379

Titre :	Fast - rate – constant - rate oxidation kinetics model for asphalt binders
Type de document :	texte imprimé
Auteurs :	Xin Jin, Auteur ; Rongbin Han, Auteur ; Yuanchen Cui, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13373-13379
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Modeling Binders Kinetic model Oxidation Kinetics Rate constant
Résumé :	Asphalt oxidative aging at constant temperature is characterized by a declining fast-rate period and a constant-rate period. While constant-rate reaction kinetics are known for many asphalt materials, much less is known about the equally important fast-rate region. Fifteen modified and unmodified asphalts were aged at five temperatures in 1 atm air, with samples collected during both fast-rate and constant-rate periods. Arrhenius kinetics parameters were obtained for both reactions; an additional parameter characterizes the total oxidation that occurs by the fast-rate, first-order reaction. Interestingly, the data show correlations between the kinetics parameters. Viscosity hardening in response to oxidation, as characterized by hardening susceptibility, is not significantly different for the two aging periods for a single binder. Therefore, the combined first-order, zero-order oxidation model together with hardening susceptibility is capable of modeling asphalt oxidation and hardening. Such a capability is fundamentally important to modeling pavement oxidation, to predicting pavement performance, and to improving pavement design.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267495

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13362-13372

Titre :	Anodic dissolution of pure aluminum during electrocoagulation process : influence of supporting electrolyte, Initial pH, and current density
Type de document :	texte imprimé
Auteurs :	Khaled Mansouri, Auteur ; Karim Ibrik, Auteur ; Nasr Bensalah, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13362-13372
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Density pH Electrolyte Electrocoagulation Dissolution
Résumé :	In this work, effects of some experimental parameters (supporting electrolyte, initial pH, and current density) on aluminum corrosion and anodic dissolution of aluminum during electrocoagulation process were investigated. Potentiodynamic polarization tests, impedance spectroscopy measurements and potentisotatic current density transients were used to evaluate corrosion parameters and verify effects of supporting electrolyte and initial pH on aluminum corrosion. The presence of NaCl and Na2SO4 shifted the corrosion potential toward more cathodic potentials, indicating that corrosion of aluminum is catalyzed by the presence NaCl and Na2SO4. On the contrary, the presence of NaH2PO4 increased the corrosion potential, which indicates that the presence of NaH2PO4 inhibits the corrosion of aluminum. Galvanostatic electrolyses demonstrated that measured concentrations of aluminum exceeded theoretical values calculated using Faraday's Law. The excess in dissolved aluminum produced during galvanostatic electrolyses is primary due to the chemical dissolution of aluminum, which is more significant at highly alkaline conditions. A final pH of value around pH 9 was observed in the presence of NaCl for pH values in the range pH 4―11 which can be explained by buffering effects of aluminum hydroxides.
DEWEY :	660
ISSN :	088-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267494

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13355-13361

Titre :	Preparation of Mesoporous ZnO Microspheres through a Membrane-Dispersion Microstructured Reactor and a Hydrothermal Treatment
Type de document :	texte imprimé
Auteurs :	Chunling Zhang, Auteur ; Yujun Wang, Auteur ; Siwei Bi, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13355-13361
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Hydrothermal treatment Reactor Dispersion Microsphere Preparation
Résumé :	Mesoporous ZnO microspheres with a diameter of about 10 μm were prepared through the combination of a membrane-dispersion microstructured reactor with a hydrothermal process. First, ZnSO4 reacted with NH4HCO3 in a membrane-dispersion reactor to produce the Zn5(CO3)2(OH)6 precursor, and then the precursor was treated at the temperature of 80 °C for 2 h to form the Zn5(CO3)2(OH)6 microspheres aided by the surfactant CTAB or F127; after the calcinations, mesoporous ZnO microspheres were obtained. The experimental results showed that the morphology of ZnO microspheres obtained using the membrane-dispersion microstructured reactor to mix the raw materials was better than that of those obtained using stirred tanks. Without surfactants and the hydrothermal treatment of the precursors, uniform ZnO microspheres could not be obtained. The SEM images showed that the monodispersed ZnO microspheres were assembled by the plates, and deeper observations revealed that these plates were aggregated by the ZnO nanorods formed by ZnO nanoparticles with a diameter of 9.0 nm. The adsorption-desorption isotherm curve indicated that the ZnO microspheres had mesoporous structures with an average pore diameter of 13.8 nm when using CTAB as the surfactant, and the specific surface area of the ZnO microspheres could reach 71.3 m2/g, much higher than that of ZnO nanoparticles.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267493

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13347–13354

Titre :	An Efficient Catalyst for the Large Scale Production of Multi-Walled Carbon Nanotubes
Type de document :	texte imprimé
Auteurs :	Jayaseelan Logeswari, Auteur ; Arumugam Pandurangan, Auteur ; Dharmalingam Sangeetha, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13347–13354
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Carbon nanotubes
Résumé :	The main objective of this work is to design an efficient catalyst for the synthesis of multiwalled carbon nanotubes (MWNTs) in our scalable, high quality with gram amount synthesis. The catalysts with composition of Fe, Mo, and MgO in the molar ratios 1:0.5:13, 1:1:13, and 1:1:50 were prepared by combustion method. The high acetylene conversion and carbon yield of chemical vapor deposition (CVD) reaction suggest the formation of MWNTs by 1:1:50 molar ratio catalysts under pyrolysis of the pure C2H2 gas with the flow rate about 60 mL/min at 800 ̊C for 30 min. The catalysts and the resulting CNT samples were analyzed by XRD, TGA, FT-Raman, SEM, and TEM to establish a relation between catalyst design and MWNT yield. Raman results indicate that CNTs are in multiwalled structure, since no single-walled characteristic features appear in the 200–400 cm–1 region. We give evidence that increased carbon conversion, carbon yields and % purity of more than 65%, 1000%, and 99%, respectively, with respect to our catalysts are directly related to ratio between Fe–Mo and MgO. One g of acetylene containing 0.9231 g of carbon would enter the reaction chamber, which is responsible for the 1.96, 1.9842, and 2.2356 g of the carbon deposition per 200 mg of catalyst A, B, and C respectively.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie102525u

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13340-13346

Titre :	Sulfur-Emission-Free Process of Molybdenum Carbide Synthesis by Lime-Enhanced Molybdenum Disulfide Reduction with Methane
Type de document :	texte imprimé
Auteurs :	Samad Ghasemi, Auteur ; Mohammad Hasan Abbasi, Auteur ; Ali Saidi, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13340-13346
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Molybdenum carbide Molybdenum disulfide
Résumé :	To investigate a sulfur-emission-free process of molybdenum carbide synthesis from molybdenite, the reaction pathways of MoS2 reduction with methane in the presence of lime (CaO) have been studied. A mixture of MoS2 + 2CaO was reduced isothermally with CH4 in a microreactor, and the composition of effluent gases and the reduced fraction were determined as a function of reaction time. Analysis of the solid phase at different reaction times at 800 °C showed the formation of CaMoO4 as an intermediate phase. Hence, the reaction pathways proposed for reduction of MoS2 + CaO with CH4 involves the direct reduction of MoS2 with CH4 to form Mo2C and sulfur-containing gases. The sulfur-containing gases are captured by CaO to form CaS, CO(g), CO2(g), and H2O(g). The uureacted MoS2 is oxidized by CO2(g) and H2O(g) to form MoO3(g), which reacted with CaO to form CaMoO4 on CaO particles. Finally, CaMoO4 and remaining MoS2 are further reduced with CH4, Characterization of solid samples was carried out by XRD, CHN, and FE-SEM equipped with EDS, providing results consistent with the proposed reaction pathways. Carbon content of solid sample increased with reduction time, and in fully reduced sample at 800 °C it was well above the stoichiometric amount indicating considerable excess carbon deposition due to CH4 cracking.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201860h

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13330–13339

Titre :	Kinetics of copper oxidation in the air reactor of a chemical looping combustion system using the law of additive reaction times
Type de document :	texte imprimé
Auteurs :	Asad H. Sahir, Auteur ; JoAnn S. Lighty, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13330–13339
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Kinetics Oxidation
Résumé :	Chemical looping combustion (CLC) is one of the promising technologies for fuel combustion which has the potential to reduce the energy penalty associated with the CO2 capture process. A CLC system typically consists of two interconnected fluidized beds that act as a fuel and an air reactor, with a recirculating metal/metal-oxide system acting as the carrier of oxygen from the latter to the former. Insights to the design and optimization of an air reactor in a CLC process could be obtained by analyzing the oxidation kinetics by the Law of Additive Reaction Times. The law offers an approximate closed form solution for a gas–solid reaction in which structural changes on reaction can be neglected. It takes into account the pore diffusion of gaseous species in the interior of the porous oxygen carrier. This is in contrast to shrinking-core model, which assumes the occurrence of the reaction along a well-defined sharp reaction interface that progresses into the solid as the reaction occurs; when applied to an initially porous solid, this model is only appropriate when pore diffusion is controlling. This law provides a convenient and realistic means for analyzing the oxidation process in an air reactor of a CLC system.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201577g

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13322-13329

Titre :	Low - temperature catalytic oxidation of monochlorobenzene by ozone over silica - supported manganese oxide
Type de document :	texte imprimé
Auteurs :	Hsu Sheng Liang, Auteur ; Hou Chuan Wang, Auteur ; Moo Been Chang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13322-13329
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Oxidation Catalytic reaction Low temperature
Résumé :	In this study, we investigated the use of a silica-supported manganese oxide prepared through the impregnation method for the low-temperature (<150 °C) ozone catalytic oxidation (OZCO) of gaseous monochlorobenzene (MCB). Moreover, the effects of various operating parameters including the reaction temperature, ozone concentration, and space velocity (SV) on MCB removal were also evaluated. In the absence of ozone, MCB conversion achieved over 10 wt % MnOx/SiO2 was only 15% at 250 °C; the conversion increased to 90.4% over 10 wt % MnOx/SiO2 when 900 ppm of ozone was added at 120 °C and SV = 300 000 h―1. In the kinetic analysis, the power-rate law feasibly describes the data of MCB oxidation via OZCO reaction. For temperatures lower than 120 °C, the activation energy and frequency factor were 10.5 kJ mol―1 and 8.05 x 102 L1.187 mol―0.187 g―1 s―1, respectively. Furthermore, the economic feasibility analysis conducted by comparing the cost of the OZCO process relative to that of general catalytic oxidation using V2O5-based catalysts indicates that the OZCO process is more cost-effective for the removal of MCB from flue gas.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267489

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13313–13321

Titre :	Modeling of chemical vapor deposition of pyrolytic carbon in a gas - spouted bed reactor
Type de document :	texte imprimé
Auteurs :	Palash Kumar Mollick, Auteur ; Dakshinamoorthy Sathiyamoorthy, Auteur ; Pandugula Thirmaleshwar Rao, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13313–13321
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Reactor Fluidization Spouted bed Chemical vapor deposition Modeling
Résumé :	Spouted beds are used in chemical vapor deposition as they provide good solid mixing, thereby enhancing high mass and heat transfer rates. In the present study, investigations on the kinetics of a coating process by chemical vapor deposition were carried out in a spouted-bed reactor. Pyrolytic carbon coatings were studied by thermal cracking of acetylene mixed with carrier gas argon at 1350 °C. A theoretical model was proposed based on the mass balance of the precursor in the spout and annulus zones at isothermal condition, and the model equations were solved using MATLAB (version 7.1) software. The effect of the operating gas velocity, initial static bed height, and acetylene concentration on the coating rate was examined experimentally and also by simulation results. The simulated results agreed well with the experimental results. Model equations used for simulation were utilized to evaluate the reaction rate constant and radial gas diffusion coefficient and then to study the effect of spout diameter, operating gas velocity, and precursor concentration on the overall conversion of the precursor.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267488

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13304–13312

Titre :	Packed - bed catalytic cracking of oak - derived pyrolytic vapors
Type de document :	texte imprimé
Auteurs :	David J. Mihalcik, Auteur ; Akwasi A. Boateng, Auteur ; Charles A. Mullen, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13304–13312
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Catalytic Pyrolysis vapors
Résumé :	Catalytic upgrading of pyrolysis vapors derived from oak was carried out using a fixed-bed catalytic column at 425 °C. The vapors were drawn by splitting a fraction from the full stream of vapors produced at 500 °C in a 5 kg/h bench-scale fast pyrolysis reactor system downstream from the cyclone separator. The placement of the fixed-bed column was varied within the condenser train to determine the effect of temperature, residual water, solids, and oxygenated components of the approach vapor stream on the upgraded product quality. The upgraded liquid was collected by immediate contact with a dry ice acetone bath, complimented by a secondary collection system comprised of a methanol spray condenser. Quantitative gas chromatography/mass spectroscopy (GC/MS) analysis of the recovered liquid showed a substantial decrease of oxygen-containing species with a significant increase in carbon-rich (≥C6) aromatic hydrocarbons. The extent of deoxygenation was location-specific and dependent upon temperature and the relative concentrations of water, oxygenates, and residual solids in the approach vapor. The study provides the engineering practicality to catalytic vapor upgrading and offers the necessary data for the design and optimization of a full-stream upgrading of pyrolysis oils via in situ vapor cracking.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201831e

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13299–13303

Titre :	Synthesis and UV Absorption Properties of Aurintricarboxylic Acid Intercalated Zn–Al Layered Double Hydroxides
Type de document :	texte imprimé
Auteurs :	Haifeng Zhu, Auteur ; Yongjun Feng, Auteur ; Pinggui Tang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13299–13303
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Ultraviolet radiation
Résumé :	Aurintricarboxylic acid (ATA), a UV absorbent, has successfully been intercalated into the interlayer spacing of Zn-Al-NO3LDHs precursor through an anion-exchange reaction. The structure and the thermal- and photostability of the intercalated product were investigated by various techniques such as powder X-ray diffraction (XRD), infrared spectroscopy (FT-IR), thermogravimetry and differential thermal analysis (TG―DTA), and UV―vis spectroscopy. The increase of the basal spacing from 0.90 to 1.52 nm as observed by XRD suggests that the ATA anions have replaced the NO3― anions in the interlayer region of the precursor LDHs. The results of infrared spectroscopy and thermogravimetry and differential thermal analysis (TG―DTA) also reveal the presence of supramolecular host—guest interactions between the brucite-like sheet and the intercalated ATA anions. The intercalation of the ATA anions into the LDHs markedly enhances the thermal stability of this UV absorbent After incorporation of 1 wt % ZnAl-ATA-LDHs to polypropylene (PP), also, the resulted ZnAl-ATA-LDHs/PP composite has much higher resistance to UV degradation related to PP.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267486

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13288-13298

Titre :	Thorium (IV) removal and recovery from aqueous solutions using tannin - modified poly (glycidylmethacrylate) - grafted zirconium oxide densified cellulose
Type de document :	texte imprimé
Auteurs :	Thayyath S. Anirudhan, Auteur ; Sylaja R. Rejeena, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13288-13298
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Aqueous solution
Résumé :	A novel adsorbent, tannin-modified poly(glycidylmethacrylate)-grafted zirconium oxide-densified cellulose (TMPGZDC) was synthesized by graft copolymerization reaction of glycidylmethacrylate onto zirconium oxide densified cellulose (ZDC) in the presence of N,N'-methylenebuacrylamide as cross-linker followed by tannin immobilization, and well characterized. The adsorption efficiency of TMPGZDC toward thorium(IV) from aqueous solutions was studied at different optimized conditions. The optimum pH for maximum adsorption was found to be 5.5 with the adsorption percentage of99.2% for an initial concentration of 10 mg/L Equilibrium was achieved within 2 h. The kinetic data were found to follow pseudo-second-order model, which assumes the presence of chemisorption. The temperature dependence indicates an exothermic process. The well agreement of equilibrium data with Langmuir isotherm and Redlich-Peterson isotherm models confirms the monolayer coverage of Th(IV) onto TMPGZDC surface and the maximum adsorption capacity was found to be 96.7 mg/g. Complete removal of Th(IV) from simulated seawater was possible with an adsorbent dosage of 3.0 g/L. Spent adsorbent was effectively degenerated with 0.1 M HNO3. The present investigation shows that TMPGZDC is a promising adsorbent for the removal and recovery of Th(IV) from aqueous solutions.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267485

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13280–13287

Titre :	Novel interpenetrating polymer network hydrogel microspheres of chitosan and poly (acrylamide) - grafted - guar gum for controlled release of ciprofloxacin
Type de document :	texte imprimé
Auteurs :	Praveen B. Kajjari, Auteur ; Lata S. Manjeshwar, Auteur ; Tejraj M. Aminabhavi, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13280–13287
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Polymer Hydrogel Microspheres
Résumé :	Acrylamide-grafted-guar gum (pAAm-g-GG) was prepared and blended with chitosan (CS) to form interpenetrating polymer network (IPN) hydrogel microspheres by the emulsion cross-linking method using glutaraldehyde (GA) as a cross-linker. The microspheres encapsulated up to 74% of ciprofloxacin (CFX), an antibiotic drug, having a plasma half-life of 4 h and the release of CFX was extended up to 12 h. Scanning electron microscopy (SEM) confirmed their spherical structure with smooth surfaces; Fourier transform infrared spectroscopy (FTIR) confirmed the grafting reaction as well as chemical stability of CFX in the blend IPN hydrogel microspheres. Differential scanning calorimetry (DSC) and X-ray diffraction (XRD) techniques confirmed the molecular level dispersion of CFX in the matrix. Swelling of microspheres performed in pH 7.4 buffer media was used to understand the drug release kinetics. In vitro release of CFX in pH 1.2 and 7.4 media showed a dependence on blend composition of the IPN, extent of cross-linking as well as initial drug loading. In vitro release data was analyzed using empirical equations, namely, Korsmeyer–Peppas, to compute the diffusion exponent (n), whose value ranged between 0.19 and 0.33, indicating non-Fickian transport of CFX through the blend IPN hydrogel microspheres.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie2012856

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13273-13279

Titre :	Effect of calcination temperature on catalytic hydrolysis of COS over CoNiAl catalysts derived from hydrotalcite precursor
Type de document :	texte imprimé
Auteurs :	Honghong Yi, Auteur ; Hongyan Wang, Auteur ; Xiaolong Tang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13273-13279
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Precursor Catalyst Hydrolysis Catalytic reaction Calcining
Résumé :	A series of CoNiAl composite oxide catalysts were prepared by calcining the CoNiAl hydrotalcite-like precursor at various temperatures and used in the catalytic hydrolysis of carbonyl sulfide (COS). The raw CoNiAl precursor and calcined products were characterized by various technologies. The catalyst calcined at 350 °C showed excellent activity and stability for COS hydrolysis at 50 °C and GHSV of 2000 h―1 with temperature of water saturator of 25 °C. The CoNiAl precursor was decomposed at 350 °C to form NiO accompanying spinel phase and hydroxyl groups (OH―), which were active sites of the hydrolysis of COS. With lower calcination temperature, the precursor is incompletely decomposed to form mixed oxides, thereby decreasing the catalyst activity. Increasing the calcination temperature above 350 °C led to severe sintering of NiO and other active components, causing decrease in the number of active sites. The deactivation of catalysts was also investigated.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267483

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13258–13272

Titre :	Celerity - amplitude relations for solitary waves on vertically falling films
Type de document :	texte imprimé
Auteurs :	Cesar E. Meza, Auteur ; Vemuri Balakotaiah, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13258–13272
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Celerity solitary waves
Résumé :	Experimental data relating the amplitude and celerity of solitary waves on vertically falling and naturally excited films are presented over a wide of range of fluid properties and flow rates (2 < Ka < 3883, 0.08 < We < 35). It is found that for a fixed set of fluid properties (Ka) and flow rate (1/We), the celerity-amplitude relationship for all finite amplitude waves that exist on the film is nearly linear with a slope that decreases with the flow rate (1/We). For viscous fluids (2 < Ka < 129), the observed normalized maximum wave amplitude increased monotonically with the flow rate (1/We) and saturated at values around 3 (hmax ≈ 3) and found to be nearly independent of the fluid viscosity (Ka). For less viscous fluids (206 < Ka < 3883) the waves were found to be continuously evolving with maximum normalized amplitudes of about 10. A recently developed two equation h–q model is used to analyze the spatio-temporal dynamics of waves on the film. The model predictions corroborate the hypothesis that the existence of very large amplitude waves for less viscous fluids is due to the phenomenon of flow reversal (or existence of up-flows) near the wall. The model predicts a critical Ka value below which no flow reversal occurs. It is also shown that once the wave amplitude exceeds a critical value, the amplitude-celerity relationship is nearly linear for all solitary waves that exist on the film and is independent of the inlet forcing frequency or amplitude or initial conditions. Local bifurcation analysis in the traveling wave coordinate, computational results on extended domains with periodic inlet forcing, and computational results on finite domains with periodic boundary conditions are used to explain the experimentally observed wave celerity-ampliude relations on naturally excited films.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie2005803

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13250-13257

Titre :	Stabilizing the interface in the rayleigh – taylor and the saffman – taylor problems by heating
Type de document :	texte imprimé
Auteurs :	Kamuran E. Uguz, Auteur ; Lewis E. Johns, Auteur ; Ranga Narayanan, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13250-13257
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Heating
Résumé :	We can stabilize the Rayleigh―Taylor instability to perturbations of any wavelength by heating from above. The same is true for the Saffinan―Taylor instability. We present formulas for estimating the temperature difference required to do this and find that more reasonable temperature differences obtain in the Saffman―Taylor problem because the temperature dependence of the viscosity is much stronger than the temperature dependence of the density.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267481

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13244-13249

Titre :	Effect of domain perturbations on the critical condition for steady - state thermal explosions
Type de document :	texte imprimé
Auteurs :	W. R. Batson, Auteur ; L. E. Johns, Auteur ; R. Narayanan, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13244-13249
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Thermal explosion Steady state Critical conditions
Résumé :	A region heated by a temperature-dependent source is said to be stable if the heat conducted to the surroundings can balance the heat generated in the region. The critical value of the Frank-Kamenetskii number gives the limit of stability, the point at which a steady temperature field is no longer possible. Assuming that the critical Frank-Kamenetskii number can be obtained for a symmetric region where the problem is one-dimensional, we present a method for determining how it changes as the region is displaced into a less-symmetric region. We find that the displacement can be either stabilizing or destabilizing. The case of exponential heat generation is fairly well-predicted by the case of linear heat generation.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267480

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13236–13243

Titre :	Chemical engineering at the cellular scale : cellular signal processing
Type de document :	texte imprimé
Auteurs :	J. Krishnan, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13236–13243
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Cellular processes Cellular signal
Résumé :	There has been a considerable effort in the past decade to understand different aspects of cellular processes from both a reverse engineering and, more recently, a synthetic perspective. In this article I provide a perspective on aspects of cellular signal processing which involve traditional chemical engineering elements (reactions, transport, control) and their variants, along with additional ingredients, sometimes combined in unusual ways. I also compare and contrast certain basic aspects of chemical engineering and cellular signal processing in areas of mutual overlap.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie200323p

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13230-13235

Titre :	Liquid – liquid mixing in coiled flow inverter
Type de document :	texte imprimé
Auteurs :	Monisha Mridha Mandal, Auteur ; Palka Aggarwal, Auteur ; K. D. P. Nigam, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13230-13235
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Mixing
Résumé :	The mixing of liquids is a common operation in process industries such as refineries and chemical and pharmaceutical industries, etc. However, the problem of mixing of different liquids has not been rigorously characterized. Therefore, the objective of this paper is to investigate liquid―liquid mixing in a novel coiled flow inverter (CFI). The device works on the principle of flow inversion which is achieved by bending a coiled tube to 90° at equidistant length. In the present study, velocity field and scalar concentration distribution of liquids were characterized. The mixing performances and pressure drop in CFI was investigated and compared with that of a straight, coiled tube and helical element mixer (HEM) for a liquid flow range of 98 ≤ Re ≤ 1020. CFI exhibits significant mixing of two liquids with negligible change in pressure drop as compared to a coiled tube as well as a HEM. The present study reveals that CFI is an efficient device for the mixing of two liquids in process industries.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267478

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13220-13229

Titre :	Experimental and computational investigation of two phase gas — liquid flows : point source injection at the center
Type de document :	texte imprimé
Auteurs :	Ashraf Ali, Auteur ; S. Pushpavanam, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13220-13229
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Point source Two phase flow Gas liquid flow
Résumé :	In this work, an experimental and numerical investigation ofhydrodynamics in a liquid induced by a bubble plume is carried out. The gas is introduced through a needle in the center of the tank containing water. The gas―liquid flow in such systems is inherently unsteady. Particle image velocimetry (PIV) was used to experimentally determine the transient velocity fields in the system. For this gas―liquid flow system, both the fluctuating and mean liquid velocities were determined experimentally by 2D and 3D PIV. The system was investigated for a liquid phase Reynolds number in the range of 3.7 × 104 to 1.8 × 105 and bubble phase Reynolds number in the range from 2350 to 11773. The behavior of the system was simulated in FLUENT 6.3.26 using a two fluid Euler―Lagrangian (EL) model with a constant bubble size of 5 mm. Here, water is treated as the continuous phase, and gas bubbles are treated as the dispersed phase. Motion of the bubbles renders the flow turbulent, and this effect is captured by the standard k―ε turbulence model. The temporal prediction of the flow field is compared with experimental results obtained from 2D and 3D measurements. The predictions from the 3D simulations capture the oscillating behavior found using 3D PIV. The 2D simulations predict a significantly higher value of turbulent viscosity. This is hypothesized as the reason as to why these simulations do not capture the oscillating behavior.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267477

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13210-13219

Titre :	Investigation of high - frequency, high - intensity ultrasonics for size reduction and washing of coal in aqueous medium
Type de document :	texte imprimé
Auteurs :	B. Ambedkar, Auteur ; R. Nagarajan, Auteur ; Jayanti, S., Auteur
Année de publication :	2012
Article en page(s) :	pp. 13210-13219
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Aqueous medium Coal Washing
Résumé :	While ultrasonic coal-wash is not entirely new in many countries, it has not yet been practiced in India, though it would appear that the relatively high-ash content of Indian coals would render them particularly suitable for such a washing procedure. In this study, state-of-the-art ultrasonic equipment, spanning the frequency range from highly cavitational (< 100 kHz), to mostly acoustic-streaming dominated (> 100 kHz), were used. The coal to be studied was received from Giral mine, Rajasthan, India. Four stages for ultrasound assisted coal particle breakage have been proposed and characterized with SEM images of sonicated coal. Sono-treatment, followed by the decanting process, has been found to remove detached ash effectively. Decanted coal samples were analyzed by SEM/EDX to determine the mechanism of ash removal by sonication. The present investigation also encompasses aqueous-based ultrasonic coal desulfurization. Ultrasound in aqueous medium produces OH, H2O2, HO2, O2, and ozone, which are strong oxidizing agents. The oxidation occurring in the presence of ultrasound is called αadvanced oxidation process", and this converts the sulfur present in the coal to water-soluble sulfates, thereby enhancing sulfur removal. Larger-scale trials with high-ash and sulfur coals are strongly recommended.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267476

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13202–13209

Titre :	A mechanism for the occurrence of ions in distilled water
Type de document :	texte imprimé
Auteurs :	Ramesh Balakrishnan, Auteur ; Ravi Sankannavar, Auteur ; K. Kesava Rao, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13202–13209
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Ions water Solar distillation
Résumé :	Solar distillation can be used to produce potable water from contaminated water. However, studies show that ions such as F– and NO3– occur in distillates from solar stills. In order to understand the reasons for this behavior, imaging and distillation experiments were conducted. White dots were seen in the vapor space above the interface of hot water poured into containers. The concentrations of various ions such as F– and SO42– in the distillates from thermal and solar distillation experiments were roughly comparable when the feed consisted of deionized water and also solutions having fluoride concentrations of 100 and 10 000 mg/L. These observations suggest that aerosols enter the distillation setup through leaks and provide nuclei for the condensation of water vapor. The water-soluble component of aerosols dissolves in the drops formed, and some of the drops are transferred to the distillate by buoyancy-driven convection.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie2002022

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13190–13201

Titre :	Constitutive models for filtered two - fluid models of fluidized gas – particle flows
Type de document :	texte imprimé
Auteurs :	Yesim Igci, Auteur ; Sankaran Sundaresan, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13190–13201
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Gas Particle flows
Résumé :	Our prior study [Igci et al., AIChE J., 2008, 54, 1431–1448] presented a methodology where computational results obtained through highly resolved simulations of a given microscopic two-fluid model (TFM) for gas-particle flows are filtered to deduce models for the residual correlations appearing in the corresponding filtered TFM equations that are appropriate for coarse-grid simulations of gas-particle flows. In the present study, we have performed a large number of highly resolved simulations of a kinetic theory based TFM in two- and three-dimensional periodic domains using this methodology and filtered the results to generate computational data on the filtered drag coefficient, the filtered particle phase pressure, and the filtered particle phase viscosity. These results have been captured in the form of correlations that can readily be employed in coarse-grid simulations of gas-particle flows.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie200190q

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13169–13189

Titre :	Analysis of entropy generation due to natural convection in rhombic enclosures
Type de document :	texte imprimé
Auteurs :	R. Anandalakshmi, Auteur ; Tanmay Basak, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13169–13189
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Entropy generation
Résumé :	One way of increasing the energy efficiency in thermal processing of materials is to reduce exergy losses due to irreversibilities, measured as “entropy generation”. In this study, an analysis of entropy generation during natural convection in rhombic enclosures with various inclination angles (φ = 30°, 45°, and 75°) has been carried out for the efficient thermal processing of various fluids (Prandtl numbers of Pr = 0.015, 0.7, 7.2, and 1000) in a range of Rayleigh numbers (Ra = 103–105). The enclosure is bounded by an adiabatic top wall, cold side walls, and an isothermally (case 1) and nonisothermally (case 2) heated bottom wall. Isotherms (θ), streamlines (ψ), and entropy generation contours due to heat transfer (Sθ) and fluid friction irreversibility (Sψ) are analyzed for both cases. At low Rayleigh number (Ra = 103), the entropy generation in the cavity is dominated by Sθ for all φ, irrespective of Pr. As Ra increases to 105, the fluid flow intensifies and Sψ also increases for all φ, irrespective of Pr. The total entropy generation (Stotal), average Bejan number (Beav), and average heat-transfer rate (Nub) are plotted for Rayleigh number ranges of 103 ≤ Ra ≤ 105. The total entropy generation (Stotal) is found to be low for φ = 30° and high for φ = 75° for all Pr values at Ra = 105. Analysis of variations of Beav with Ra for high-Pr fluids indicates that Sψ contributes significantly for increase in Stotal. It is also found that the largest heat-transfer rate (Nub) corresponds to minimum entropy generation (Stotal) for φ = 30° cavities at Ra = 105 with all Pr in case 1. The nonisothermal heating strategy (case 2) is energy efficient, because of its lower Stotal value, corresponding to low Nub, which is due to a lesser heating effect than case 1 for all φ. Overall, rhombic cavities with φ = 30° may be the optimal geometrical design for thermal processing of all types of fluids (Pr = 0.015, 0.7, 7.2, and 1000), irrespective of the heating strategy.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie200184y

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13161–13168

Titre :	Influence of shear thinning on viscoelastic fluid – structure interaction in a two - dimensional collapsible channel
Type de document :	texte imprimé
Auteurs :	Debadi Chakraborty, Auteur ; J. Ravi Prakash, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13161–13168
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Viscoelastic Fluid structure
Résumé :	We compute numerically the steady flow of a viscoelastic FENE-P fluid in a two-dimensional collapsible channel, in which a zero-thickness membrane under constant tension has replaced part of the top wall. This geometry has been studied extensively as a benchmark to examine fluid-structure interactions between a flowing Newtonian fluid and a deformable wall. The rheological behavior of the viscoelastic FENE-P fluid is described in terms of a conformation tensor model. The mesh equation and transport equations are discretized using the discrete elastic viscous stress split-traceless gradient (DEVSS-TG/SUPG) mixed finite-element method. The influence of viscoelasticity and shear thinning on flow patterns and stress profiles is examined, and comparisons with Newtonian predictions are reported. The existence of a limiting Weissenberg number beyond which computations fail is demonstrated. The extent of shear thinning is shown to be a key factor in determining the nature of the fluid-structure interaction.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie200173b

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13137–13160

Titre :	Effects of particle diameter and position on hydrodynamics around a confined sphere
Type de document :	texte imprimé
Auteurs :	Suresh Krishnan, Auteur ; Kannan Aravamudan, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13137–13160
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Hydrodynamics
Résumé :	The effect of confinement of a sphere within a tube on the hydrodynamics of Newtonian fluid flow around the solid surface is investigated. The ratio of particle diameter to tube diameter (blockage ratio), the ratio of sphere distance from the tube axis to the tube diameter (eccentricity), and the fluid flow rate were the parameters of this study. Computational fluid dynamics (CFD) simulations were carried out to obtain the flow field around the sphere from which the angle of boundary layer separations, as well as drag and lift coefficients, were obtained. The pressure distributions and friction factor along the sphere surface are also reported. To estimate the effect of confinement and eccentricity in position of the particle, with respect to the tube axis, the results are compared with the classical case involving the flow of an unbounded fluid over the sphere. The drag coefficient diminished when the particle was positioned eccentrically with respect to the tube axis at very low particle Reynolds number (Rep). However, the drag coefficient increased with increasing eccentric positions at higher Rep. At eccentric particle positions, boundary layer separation occurred earlier from the upper hemisphere while, depending on the eccentricity, it was delayed or nonexistent in the lower hemisphere. The difference in pressure between the lower and upper hemisphere regions led to incursion of fluid into the upper hemispherical region. Correlations are proposed for the drag and lift coefficients in the range of 0.1≤ Rep ≤ 500 for different possible eccentricities and blockage ratios. The results from this work will be of relevance in applications such as fluidization and aseptic food processing.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie2000852

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13129–13136

Titre :	pH and temperature stresses in bioreactor cultures : intracellular superoxide levels
Type de document :	texte imprimé
Auteurs :	Pritish Sarkar, Auteur ; G. K. Suraishkumar, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13129–13136
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Bioreactor
Résumé :	Two of the most common stresses in natural environments, as well as in bioreactors, that are of importance in biofuel or bioterrorism contexts are pH and temperature stresses. Superoxide generation has been suspected as a possible reason for the effects of the above stresses, and superoxide is suspected to play a role in cell signaling. But, no information is available on a direct relationship between environmental stress and intracellular superoxide levels. We hypothesize that the exposure of cells to pH stress induces superoxide radicals, which leads to oxidative cellular damage, and thus it affects cells in culture. We tested the hypothesis on a model organism, Bacillus subtilis, which is well studied, and has relevance in biofuel and bioterrorism contexts. Bacillus subtilis cells were exposed to different pH-stress conditions (pH 5, 6, 8, or 9) and temperature-stress conditions (42, 45, 48, and 55 °C). Specific superoxide levels at pH 8 and 9 were 22% and 160%, respectively, higher than that of normal growth pH (pH 7), which was 6.48 ± 0.37 mmol (1012 live cells)−1. Superoxide generation due to pH stress has not been reported thus far in the literature. Although detection of superoxide induced by temperature stress has been reported, it has not been quantified. When Bacillus subtilis cells were exposed to 42, 45, 48, and 55 °C for 1 h, the specific intracellular superoxide levels were 52%, 150%, 220%, and 314%, respectively, higher than the value at normal growth temperature, 37 °C. The extent of intracellular lipid peroxidation was higher under the stressed conditions. The mechanism for alkaline pH-stress-induced superoxide generation seems to be the continuation of metabolic activities even though the growth is arrested. The mode of temperature-stress-mediated cell death is necrosis, and the extent of cell death is correlated with the specific intracellular superoxide level.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie200081k?mi=qryllt&af=R&pageSize=20&searchT [...]

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13116–13128

Titre :	Population balance modeling of environment dependent breakage : role of granular viscosity, density and compaction. model formulation and similarity analysis
Type de document :	texte imprimé
Auteurs :	Jayanta Chakraborty, Auteur ; Doraiswami Ramkrishna, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13116–13128
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Similarity Compaction Density Viscosity Modeling Population balance
Résumé :	In this work, we introduce mechanistic considerations in nonlinear milling of particulate material. We show that the mobility of the powder can have a significant effect on the breakage frequency. During grinding, the change in particle size leads to changes in the mobility of the powder which in turn alters the breakage rate. The mechanistic modeling, being able to accommodate different responses of powder mobility for wet and dry grinding, is able to distinguish naturally between dry and wet grinding, an attribute not possessed by other nonlinear models. It is shown that the rich variety of phenomena observed in grinding mills emanates from the interplay between opposing factors that influence the breakage environment in a mill. Such factors include viscosity, density, and compaction of the powder. For dry grinding, the change in powder porosity and viscosity leads to a variety of nonlinear effects. For wet grinding the viscosity and density of the slurry impart a nonmonotonic variation in the breakage rate with particle size. A population balance equation (PBE) for environment dependent breakage has been formulated by considering the foregoing effects. Similarity analysis of the model equation shows the existence of self-similar behavior even for the environment dependent breakage. Experimental investigation of such self-similarity provides an effective diagnostic process for validating model framework. Furthermore, when combined with the methodology of solving inverse problems (e.g., Sathyagal, A. N.; Ramkrishna, D. Chem. Eng. Sci. 1996, 51, 1377), an effective approach becomes available for model identification.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267469

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13105–13115

Titre :	Drag on a sphere in poiseuille flow of shear - thinning power - law ffuids
Type de document :	texte imprimé
Auteurs :	Daoyun Song, Auteur ; Rakesh K. Gupta, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13105–13115
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Poiseuille Flow
Résumé :	The effect of finite boundaries on the drag experienced by a sphere exposed to the Poiseuille flow of power-law fluids in cylindrical vessels has been investigated numerically. In particular, the momentum equations have been solved over the following ranges of conditions: sphere Reynolds number based on the area average velocity in the pipe, Re 1−100; power law index, n: 0.2−1, and sphere-to-tube diameter ratio, λ: 0−0.5. Due to the obstruction in the path of the fluid caused by the sphere fixed at the axis of the tube and the corresponding changes in the velocity field close to the sphere, there is extra viscous dissipation at the walls and this, in turn, leads to an increase in the drag force acting on the sphere. Conversely, there is an extra pressure drop caused by the fixed sphere for the flow of the fluid in the tube. The effect, however, is more significant at low Reynolds numbers than that at high Reynolds numbers. Similarly, the additional drag due to the confining walls increases with the increasing degree of obstruction, i.e., sphere-to-tube diameter ratio. Overall, all else being equal, the wall effect is seen to be less severe in power-law fluids than that in Newtonian fluids. Furthermore, the confining walls also influence the onset of flow separation and subsequently the size of the recirculation region. The present numerical predictions are consistent with the scant experimental results available in the literature for Newtonian and power-law fluids.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie102120p

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13092–13104

Titre :	Modification of activated carbon fiber by metal dispersion and surface functionalization for the removal of 2 - chloroethanol
Type de document :	texte imprimé
Auteurs :	Mekala Bikshapathi, Auteur ; Susovan Mandal, Auteur ; Gyanesh N. Mathur, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13092–13104
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Carbon Fiber Chloroethanol
Résumé :	Nickel-impregnated phenolic resin precursor-based activated carbon fiber (ACF) was functionalized with pyridine and investigated for the adsorptive removal of 2-chloroethanol. Adsorption tests were carried out under flow conditions for different gas flow rates, solute concentrations, and temperatures in a perforated tubular adsorber. Various analytical and spectroscopic techniques, including X-ray diffraction (XRD), Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), and CHNSO elemental analysis, were used to characterize the adsorbents that have been prepared in this study. The results showed that the ACFs adsorbed significant amounts of 2-chloroethanol. Temperature had adverse effects on adsorption. At metallic concentrations in excess of 0.4 M of nickel, the formation of metal crystallites occurred, causing blockage of the pores and a decrease in the number of active metal sites. The functionalization of ACFs by pyridine was shown to produce a basic surface, resulting in the enhanced adsorption of the organic solute. The results have applications in the preparation of effective ACF-based adsorbents for controlling the emission of hazardous organic compounds.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie101860e

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13083–13091

Titre :	Intensification of the dissolution of a sparingly soluble solid from a spinning disk in the presence of power ultrasound
Type de document :	texte imprimé
Auteurs :	D. Krishna Sandilya, Auteur ; A. Kannan, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13083–13091
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Power ultrasound
Résumé :	The effect of power ultrasound (20 kHz) on the dissolution rates of a spinning disk made from sparingly soluble benzoic acid was investigated. Ultrasound was found to intensify the dissolution rates especially at lower rotational speeds of the spinning disk. The ultrasonic intensification was found to decrease with increase in the rotational speed of the spinning disk. Empirical correlation was developed for the Sherwood number in the presence of ultrasound and mechanical rotation of the disk. From this, the intensification factor was derived in terms of ultrasonic power input and Reynolds number corresponding to the spinning disk. The intensification factor obtained in the current spinning disk configuration was compared with that obtained for the rotating cylinder configuration studied by Kannan and Pathan [Kannan, A.; Pathan, S. K. Enhancement of Solid Dissolution Process. Chem. Eng. J.2004, 102, 45.].
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie101702u

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13076–13082

Titre :	The gibbs - duhem equation, the ideal gas mixture, and a generalized interpretation of dalton’s law
Type de document :	texte imprimé
Auteurs :	R. Ravi, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13076–13082
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Gibbs duhem equation Gas mixture
Résumé :	The ideas used by Gibbs in defining the ideal gas mixture are brought to light in view of their fundamental significance and the fact that they have not received due attention in the literature. Specifically, the central role played by the well-known Gibbs−Duhem equation in this regard is explained. The concept of a fundamental equation and its importance in the definition of an ideal gas as well as an ideal gas mixture is elucidated. The manner in which these ideas enabled Gibbs to give a very general interpretation of Dalton’s law is examined in detail.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie101614s

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13066-13075

Titre :	Prediction of liquid – liquid equilibria for biofuel applications by quantum chemical calculations using the cosmo - SAC method
Type de document :	texte imprimé
Auteurs :	Mitesh R. Shah, Auteur ; Ganapati D. Yadav, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13066-13075
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Phase equilibrium Liquid liquid equilibrium Prediction
Résumé :	Currently, there is a great interest in the production of biofuels such as biodiesel, bioethanol and biobutanol. These processes involve liquid―liquid equilibria, which are important for the overall design of the process. However, suitable experimental data are often scarce. The Cosmo-SAC model provides a method to predict liquid―liquid equilibrium data from quantum chemical calculations without any experimental data. Hence, it can be used to provide initial estimates where experimental data are not available. In this work, we have evaluated the Cosmo-SAC model for the liquid―liquid equilibria involved in biodiesel production and bioalcohol extraction using ionic liquids, and we have compared it with the currently available experimental data.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267464

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13056–13065

Titre :	Influence of feed entry on the segregation of a binary mixture of solids in a continuous fast fluidized bed
Type de document :	texte imprimé
Auteurs :	K. Ganesh Palappan, Auteur ; P. S. T. Sai, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13056–13065
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Fast fluidized
Résumé :	Studies on the influence of feed entry on segregation using continuous fast fluidization is not clearly understood even though studies are available on the segregation of particles in continuous bubbling/turbulent fluidized beds. In the present study, four different feed inlet positions are selected and tested in a 69 mm ID and 3.65 m height continuous fast fluidized bed. The feed is a binary mixture of solid particles of the same size, but different density. The inimitable observations noticed at various feed locations on fluidization behavior with segregation is discussed. Change in the feed inlet height of the fluidized bed is reflected drastically on the compositions of top and bottom products. Disparate behavior of continuous fluidization is noticed at selected feed inlet positions. Operation is not stable due to either particle congestion in the feeding line or nonuniform discharge of solids from the fluidized bed when the feed inlet position is located close to distributor. Further an enhanced-feed inlet location created a particle’s cloud above the dense phase. Excess of feed inlet height transformed the binary mixture severance and freeboard height. The optimum operating gas velocity required for maximum separation of both species is identified at every feed entry for different feed rates. A unique feed entry location is recognized for maximum separation of both the species and minimum gas.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie200093d

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13045-13055

Titre :	Optimal plant friendly input design for system identification
Type de document :	texte imprimé
Auteurs :	Sridharakumar Narasimhan, Auteur ; S. Arun Srikanth, Auteur ; J. V. N. Sreeram, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13045-13055
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	System identification Design
Résumé :	The primary objective in solving optimal input design problems is to obtain maximally informative inputs to be used as perturbation signals in system identification experiments. In plant-fiiendly identification, the designer has to respect constraints on experiment time, input and output amplitudes or input move sizes. This work focuses on plant friendly input design with constraints on input move size and output power. We present a convex relaxation to the problem of designing an informative input subject to input move size and output power constraints. The problem is finitely parametrized using ideas from Tchebycheff systems and reformulated as a SemiDefinite Progamme.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267462

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13037-13044

Titre :	Effect of alkaline hydroxides on the vapor − liquid equilibrium of ammonia / water and the performance of absorption chillers
Type de document :	texte imprimé
Auteurs :	Simona Steiu, Auteur ; David Martínez-Maradiaga, Auteur ; Daniel Salavera, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13037-13044
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Phase equilibrium Liquid vapor equilibrium
Résumé :	New simple and accurate correlations of the equilibrium properties and solution enthalpies for NH3/H2O/alkaline hydroxide mixtures are presented for use in the modeling and design of absorption chillers in a temperature range between 273.15 and 353.15 K. The correlations are used to calculate the P—T—x diagrams and show the effect of hydroxide on the liquid-vapor equilibrium. Finally, the correlations presented are used to estimate the improvement in the cycle performance in absorption chillers when NH3/H2O mixtures containing NaOH are used instead of the conventional NH3/H2O mixture. Results show that the addition of hydroxide can significantly decrease the generator temperature of ammonia/water absorption refrigeration cycles while simultaneously increasing the Coefficient of Performance (COP). For a NaOH concentration of 12%, the temperature at the generator decreases by about 17°C, the COP increases by 28%, and the size of the rectifier can be up to 46% less than that required when the conventional NH3/H2O cycle is used.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267461

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13030-13036

Titre :	Polymer - functionalized nanoparticles for improving waterflood sweep efficiency : characterization and transport properties
Type de document :	texte imprimé
Auteurs :	R. Ponnapati, Auteur ; O. Karazincir, Auteur ; E. Dao, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13030-13036
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Transport properties Nanoparticle
Résumé :	Water-dispersible polymer―silica nanocomposite particles, SiO2―ethylene oxide-based polymer nanoparticles hybrids, were synthesized using a "grafting-from" method, where polymer brushes were grown on silica nanoparticles using living radical polymerization. Water-soluble polymer chains were grown from initiator-tethered 15-nm silica nanopartides with ∼600 chains grafted per nanopartide, resulting in a surface grafting of∼1 chain per square nanometer. The single-phase and multiphase transport properties of low concentration brine dispersions of these polymer nanoparticles hybrids through a Berea sandstone core were measured. Experiments show that, while the viscosity increase is modest for dispersions with concentrations of 0.5― 2 wt % of the nanopartide hybrid, the dispersions were able to transport without hindrance through the porous media and, furthermore, were found to be effective at mobilizing waterflood residual oil.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267460

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13021-13029

Titre :	Carbothermal synthesis of aerosol - based adsorptive - reactive iron – carbon particles for the remediation of chlorinated hydrocarbons
Type de document :	texte imprimé
Auteurs :	Jingjing Zhan, Auteur ; Bhanukiran Sunkara, Auteur ; Jingjian Tang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13021-13029
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Decontamination Aerosols
Résumé :	Spherical iron—carbon nanocomposites were synthesized through a facile aerosol-based process and a subsequent carbothermal reduction. The distribution and immobilization of iron particles throughout the carbon microspheres prevents nanoiron aggregation, allowing the maintenance of particle reactivity. The carbon microspheres allow adsorption of TCE, thus removing dissolved TCE rapidly and facilitating reaction by increasing the local concentration ofTCE in the vicinity of iron particles. The strongly adsorptive property of the composites may prevent release of toxic chlorinated intermediate products. The nanoscale composite particle size is in the optimal range for effective transport through groundwater saturated sediments. It is also shown that carbothermal treatment of the composite material leads to highly porous carbon materials containing zerovalent iron species, a necessary reactive component in the reaction pathway. The mesoporous structure generated allows access to internal reactive sites.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267459

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13012–13020

Titre :	Biomimicked superhydrophobic polymeric and carbon surfaces
Type de document :	texte imprimé
Auteurs :	Chandra S. Sharma, Auteur ; Kumar Abhishek, Auteur ; Hari Katepalli, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13012–13020
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Carbon Polymer
Résumé :	We report two direct and easy ways of fabricating stable, superhydrophobic polymeric and carbon surfaces directly by biomimicking the patterns found on natural plant leaves by micromolding and nanoimprint lithography. Two distinct classes of naturally occurring microtextures on superhydrophobic leaves were mimicked in this study, which include leaves of Elephant creeper (Argyreia Nervosa) and Nasturtium (Tropaeolum Majus). These show structural superhydrophobicity derived from high aspect ratio hairs and lower aspect ratio microtextures, respectively. Both the textures could be replicated by micromolding in different polymers, polydimethylsiloxane, polystyrene, and an organic resorcinol-formaldehyde (RF) gel. Patterned RF gel surfaces yielded superhydrophobic carbon surfaces upon pyrolysis because RF gel is a polymer precursor to glassy carbon. The nanoimprint lithography could be used for a direct transfer of the lower aspect ratio leaf patterns on the surfaces of various other polymers like poly(ethylene terephthalate) and poly(methyl methacrylate).
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie200369r

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 13000–13011

Titre :	Filling characteristics for an activated carbon based adsorbed natural gas storage system
Type de document :	texte imprimé
Auteurs :	Pradeepta K. Sahoo, Auteur ; Mathew John, Auteur ; Bharat L. Newalkar, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13000–13011
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Carbon Natural gas
Résumé :	The storage capacity of an activated carbon bed is studied using a 2D transport model with constant inlet flow conditions. The predicted filling times and variation in bed pressure and temperature are in good agreement with experimental observations obtained using a 1.82 L prototype ANG storage cylinder. Storage efficiencies based on the maximum achievable V/V (volume of gas/volume of container) and filling times are used to quantify the performance of the charging process. For the high permeability beds used in the experiments, storage efficiencies are controlled by the rate of heat removal. Filling times, defined as the time at which the bed pressure reaches 3.5 MPa, range from 120 to 3.4 min for inlet flow rates of 1.0 L min–1 and 30.0 L min–1, respectively. The corresponding storage efficiencies, ηs, vary from 90% to 76%, respectively. Simulations with L/D ratios ranging from 0.35 to 7.8 indicate that the storage efficiencies can be improved with an increase in the L/D ratios and/or with water cooled convection. Thus for an inlet flow rate of 30.0 L min–1, an ηs value of 90% can be obtained with water cooling for an L/D ratio of 7.8 and a filling time of a few minutes. In the absence of water cooling the ηs value reduces to 83% at the same L/D ratio. Our study suggests that with an appropriate choice of cylinder dimensions, solutions based on convective cooling during adsorptive storage are possible with some compromise in the storage capacity.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie200241x

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 12990–12999

Titre :	Measurement and analysis of effective thermal conductivity of MmNi4.5Al0.5 hydride bed
Type de document :	texte imprimé
Auteurs :	E. Anil Kumar, Auteur ; M. Prakash Maiya, Auteur ; S. Srinivasa Murthy, Auteur
Année de publication :	2012
Article en page(s) :	pp. 12990–12999
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Thermal conductivity
Résumé :	The effective thermal conductivity (ke) of a MmNi4.5Al0.5 hydride powder bed was measured using an one-dimensional steady-state axial heat transfer comparative method. The experiments showed that ke lies between 0.1 and 1.2 W/m K in the pressure and the temperature ranges of 0–50 bar and 0–100 °C, respectively. While hydrogen pressure and concentration showed strong influence on ke over the complete range, the temperature effects were minimal. Thermal conductivity of the solid materials, MmNi4.5Al0.5 alloy and its hydrides, was also back calculated from the experimentally measured ke values.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie200116d

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 12984–12989

Titre :	Controlled crystallization of macromolecules using patterned substrates in a sandwiched plate geometry
Type de document :	texte imprimé
Auteurs :	Anindita Sengupta Ghatak, Auteur ; Animangsu Ghatak, Auteur
Année de publication :	2012
Article en page(s) :	pp. 12984–12989
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Macromolecules
Résumé :	Crystallization of macromolecules such as proteins and peptides is known to be influenced by the topographical and chemical heterogeneity of the substrate. However, controlling the nucleation and the growth of crystal on such surfaces has been an issue. Here, we present systematic experiments carried out on hydrophilic elastomeric substrates topographically patterned by forming stretch induced surface wrinkles; the distance between the wrinkles, importantly the density of occurrence of defects between the wrinkles, is systematically varied. Furthermore, to maximize the effect of the substrates, the crystallization experiment is carried out between two such parallel substrates, the gap between which is maintained by using spacers. This process results in very controlled evaporation of the solvent. Experiments with two different model proteins: hen egg-white lysozyme and Thaumatin from Thaoumatococcus daniellii show that on surfaces with uniformly spaced wrinkles the crystals nucleate extensively but with insignificant growth. However, when a small number of defects are introduced into the patterns, fewer crystals nucleate, which grow to form large crystals. With further increase in the defect density, extent of nucleation increases again, but with decrease in the crystal growth. Thus, the crystal size attains maxima at an intermediate wavelength of the wrinkles and the defect density.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie102596c

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 12975-12983

Titre :	Kinetic modeling and statistical optimization of lipase catalyzed enantioselective resolution of (R,S) - 2 - pentanol
Type de document :	texte imprimé
Auteurs :	Jyoti B. Sontakke, Auteur ; Ganapati D. Yadav, Auteur
Année de publication :	2012
Article en page(s) :	pp. 12975-12983
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Modeling Enzymatic catalysis Optimization Kinetic model
Résumé :	S-2-pentanol is a chiral intermediate in the synthesis of several potential antialzheimer's drugs that inhibit β-amyloid peptide release or its synthesis. The present work focuses on the kinetic resolution of (R,S)-2-pentanol using vinyl acetate as an acyl donor. Effects of various parameters were studied to deduce the kinetics and mechanism of the reaction. Novozyme 435 was found to be the most efficient catalyst among different catalysts studied Response Surface methodology and Box-Behnken design were employed to evaluate the effect of process parameters such as speed of agitation, enzyme loading, temperature and acyl donor/ alcohol molar ratio on conversion, enantiomeric excess, enantioselectivity and initial rate. Initial rate data and progress curve data were used to arrive at a suitable model. Ping-pong bi-bi mechanism with 2-pentanol inhibition was found to describe the kinetics of the reaction. The kinetic parameters evaluated from initial rate data were used to simulate the experimental results. There was a very good agreement between theory and experiment.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267454

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 12960–12974

Titre :	Incremental identification of reaction and mass – transfer kinetics using the concept of extents
Type de document :	texte imprimé
Auteurs :	Nirav Bhatt, Auteur ; Michael Amrhein, Auteur ; Dominique Bonvin, Auteur
Année de publication :	2012
Article en page(s) :	pp. 12960–12974
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Mass transfer Kinetics
Résumé :	This paper proposes a variation of the incremental approach to identify reaction and mass-transfer kinetics from concentration measurements for both homogeneous and gas–liquid reaction systems. This incremental approach proceeds in two steps: (i) computation of the extents of reaction and mass transfer from concentration measurements without explicit knowledge of the reaction and mass-transfer rate expressions, and (ii) estimation of the rate parameters for each rate expression individually from the computed extents using the integral method. The novelty consists in using extents, thereby avoiding differentiation of measured concentrations. For the computation of extents, two cases are considered: a linear transformation is used if the concentrations of all liquid-phase species can be measured; otherwise, if the concentrations of only a subset of the liquid-phase species are available, an approach that uses additional measurements of flow rates and possibly gas-phase concentration is proposed. The incremental identification approach is illustrated in simulation via two reaction systems, namely, the homogeneous acetoacetylation of pyrrole and the gas–liquid chlorination of butanoic acid.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie2007196

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 12946–12959

Titre :	Oxidation of chloride ion on platinum electrode : dynamics of electrode passivation and its effect on oxidation kinetics
Type de document :	texte imprimé
Auteurs :	Rajkumar S. Patil, Auteur ; Vinay A. Juvekar, Auteur ; Vijay M. Naik, Auteur
Année de publication :	2012
Article en page(s) :	pp. 12946–12959
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Oxidation Ion Kinetics
Résumé :	Kinetics of oxidation of chloride ion is studied on both active platinum electrode and that undergoing transient passivation. Experiments are conducted in concentrated NaCl solution at rotating disk electrode. It is observed that on the active platinum electrode, oxidation is very fast, and hence the current density is controlled by the ohmic resistance of the solution. Electrode kinetics becomes important only when the electrode is passivated to a significant extent. Kinetics of chloride oxidation on the electrode undergoing passivation is modeled using the Butler–Volmer equation, in which the contribution from the ohmic resistance of the solution is incorporated. Two regimes of passivation are identified. The first is the fast regime corresponding to the formation of the platinum oxide monolayer. In this regime, the rate of passivation is first order in the concentration of the metal sites on the surface. In the slow passivation regime, the exchange current density for chloride oxidation is found to vary inversely with square root of time. This regime is modeled by considering unsteady diffusion of oxygen ions through the metal lattice. From this analysis it is concluded that the chloride oxidation current is almost totally contributed by a small fraction of the active metal sites which are continuously being regenerated as a result of diffusion of oxygen ions from the surface into the bulk of the metal.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie200663a

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp.12933–12945

Titre :	Single - event microKinetics of aromatics hydrogenation on Pt / H - ZSM22
Type de document :	texte imprimé
Auteurs :	Tapan Bera, Auteur ; Joris W. Thybaut, Auteur ; Guy B. Marin, Auteur
Année de publication :	2012
Article en page(s) :	pp.12933–12945
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	MicroKinetics Hydrogenation
Résumé :	A fundamental Single-Event MicroKinetic (SEMK) model for the hydrogenation of aromatic components on a Pt catalyst has been developed. It is based on the Horiuti-Polanyi mechanism considering atomic hydrogen addition steps to the (partially hydrogenated) aromatic species on the catalyst surface. The reaction network used accounts for the position at which the hydrogen atoms are added to the ring. In accordance with a quantum chemical assessment of the reaction pathway it was assumed that the kinetic parameters only depend on the saturation degree of the nearest neighbor carbon atoms and the branching degree of the carbon atom involved in the hydrogen atom addition. Six reactions families, of which three occur in the reaction network for benzene, are considered. The total number of 18 model parameters was reduced to 7 by calculation of the pre-exponential factors and by accounting for thermodynamic constraints. Experimental benzene hydrogenation data measured at temperatures in the range from 423 to 498 K, benzene inlet partial pressures in the range from 10 to 60 kPa, and hydrogen inlet partial pressures from 100 to 600 kPa on Pt catalyst have been regressed. In accordance with quantum chemical, statistical, and thermodynamic calculations, the selected version of the model gives the best description of the data with an F value of 4150. According to this selected SEMK model, the activation energies for the hydrogen addition to a carbon atom between two unsaturated or two saturated carbon atoms are identical and lower than the activation energy for hydrogen addition to a carbon atom between an unsaturated and saturated hydrogen atom. The estimated chemisorption enthalpy of hydrogen amounts to −59.4 kJ mol–1 and corresponds with an average surface coverage of 30%. A value of −56.0 kJ mol–1 for the chemisorption enthalpy of benzene is obtained. The total surface coverage by hydrocarbon species amounts to 60% under typical reaction conditions, without a pronounced Most Abundant Surface Intermediate (MASI).
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie200541q

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 12925-12932

Titre :	Numerical analysis of fractal catalyst structuring in microreactors
Type de document :	texte imprimé
Auteurs :	Venkat Reddy Regatte, Auteur ; Niket S. Kaisare, Auteur
Année de publication :	2012
Article en page(s) :	pp. 12925-12932
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Microreactor Catalyst Fractal Numerical simulation Numerical analysis
Résumé :	The objective of this work is to verify the feasibility of implementing fractal structuring to reduce the amount of active catalyst surface required in microreactors. This work follows up on the work by Phillips et al. [Chem. Eng. ScL, 2003, 58, 2403―2408], where the authors reported the use of Cantor triads to reduce the total amount of active catalyst in a mass-transfer-limited system. They considered flat-plate geometry with infinitely fast reactions. This work is extended to realistic microreactors with finite rate chemistry to study the effect of catalyst structuring in the presence of flow confinement. Fractal and periodic patterns are formed by removing the catalyst from various sections along the reactor wall, resulting in alternating catalytic and noncatalytic segments. Two-dimensional computational fluid dynamics (CFD) simulations of tubular microreactor channel with catalyst structuring are performed. Our results show that the role of catalyst structuring confined geometry is rather modest, compared to the open (flat-plate) geometries considered so far. We also show that singularities (boundary of noncatalytic and catalytic segments) formed with catalyst structuring, and not the fractal pattern itself, are responsible for improved conversion from the microreactor. Large gradients at singularities result in enhanced mass transfer, which is analyzed using Sherwood number correlations. The effect of various operating parameters is investigated.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267450

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 12915-12924

Titre :	Photocatalytic activity of combustion synthesized ZrO2 and ZrO2 – TiO2 mixed oxides
Type de document :	texte imprimé
Auteurs :	Sneha Polisetti, Auteur ; Parag A. Deshpande, Auteur ; Giridhar Madras, Auteur
Année de publication :	2012
Article en page(s) :	pp. 12915-12924
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Titanium oxide Combustion Photocatalysis
Résumé :	Tetragonal ZrO2, synthesized by solution combustion technique, was found to be photocatalytically active for the degradation of anionic dyes. The compound was characterized by FT-Raman spectroscopy, X-ray photoelectron spectroscopy, FT-infrared spectroscopy, UV―vis spectroscopy, BET surface area analysis, and zero point charge pH measurement. A high concentration of surface hydroxyl groups was observed over the catalyst, as confirmed by XPS and FTIR. The photocatalytic degradation of orange G, amido black, remazol brilliant blue R, and alizarin cyanine green (ACG) was carried out with this material. The effect of pH, inorganic salts, and H2O2 on the activity of the catalyst was also studied, and it was found that the catalyst maintained its activity at a wide range of pH and in the presence of inorganic salts. Having established that ZrO2 was photocatalytically active, mixed oxide catalysts of TiO2―ZrO2 were also tested for the photocatalytic degradation of ACG, and the 50% ZrO2―TiO2 mixed oxides showed activity that was comparable to the activity of TiO2.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267449

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp.12904–12914

Titre :	Integrated multiscale methodology for virtual prototyping of porous catalysts
Type de document :	texte imprimé
Auteurs :	V. Novak, Auteur ; P. Koci, Auteur ; F. Stepanek, Auteur
Année de publication :	2012
Article en page(s) :	pp.12904–12914
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Porous catalysts
Résumé :	The microstructure of the support determines a key property of porous catalysts—effective diffusivity. Typically, supporting materials with bimodal pore size distribution are used that involve both meso- and macropores. Spatial distribution of active metal crystallites within the porous support then influences reaction rates and conversions. To optimize the catalyst support microstructure and ultimately the whole catalyst, it is necessary to relate quantitatively the morphological features of the porous structure both to its preparation conditions and to the final transport properties and catalyst performance under reaction conditions. In this paper we demonstrate the application of novel models based on the generalized volume-of-fluid method and 3D digital reconstruction of a porous structure. The procedure includes simulation of porous support formation (virtual packing of primary particles of defined shapes and sizes), drying and crystallization of impregnated metal solution (growth of metal nanoparticles), and solution of reaction and transport within the final virtual catalyst structure to obtain volume-averaged reaction rates that are then used in a full-scale model of a catalytic monolith reactor. A parametric study is performed to investigate the effects of the sizes of primary particles (influencing the meso- and macroporosity and pore sizes) and active metal impregnation conditions (influencing the distribution of active catalytic surface area) on the macroscopic activity of a catalytic monolith with Pt/γ-Al2O3 washcoat used for automotive exhaust gas aftertreatment.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie2003347

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 12895-12903

Titre :	Multicomponent dosing in membrane reactors including recycling — concept and demonstration for the oxidative dehydrogenation of propane
Type de document :	texte imprimé
Auteurs :	Christof Hamel, Auteur ; Tanya Wolff, Auteur ; Pushpavanam Subramaniam, Auteur
Année de publication :	2012
Article en page(s) :	pp. 12895-12903
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Dehydrogenation Oxidation Recycling Membrane reactor
Résumé :	The potential of a multicomponent distributed reactant dosing via membranes for enhancing selectivity and yield in a network of series and parallel reactions is investigated in this work. In a preliminary theoretical feasibility study, the optimal local concentrations of the various reactants used to improve the selectivity and conversion of the desired intermediate product were determined. These results were extended to a case study. For this examination, the oxidative dehydrogenation of propane to the kinetically limited intermediate product propylene on a VOx/γ-Al2O3 catalyst was considered. The kinetic equations and parameters were first estimated. It is shown that, compared to a single-component dosing of O2 via membranes, the yield of propylene can be almost trebled via a controlled simultaneous dosing of oxygen and propane.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267447

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 12881-12894

Titre :	Steam reforming of ethanol in a microchannel reactor : kinetic study and reactor simulation
Type de document :	texte imprimé
Auteurs :	Nageswara Rao Peela, Auteur ; Deepak Kunzru, Auteur
Année de publication :	2012
Article en page(s) :	pp. 12881-12894
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Reactor Kinetics Microreactor Steam reforming
Résumé :	The kinetics of steam reforming of ethanol (SRE) was determined at atmospheric pressure in the temperature range of 450―550 °C over 2% Rh/20% CeO2/Al2O3 in a microchannel reactor. The product distribution could be explained by a reaction scheme consisting of four reactions: reaction of steam with ethanol, decomposition of ethanol, methane steam reforming, and the water-gas shift reaction. The kinetic expression based on Langmuir―Hinshelwood kinetics could explain the experimental data satisfactorily. A two-dimensional simulation was also carried out to predict the performance of a microchannel SRE reactor in which the endothermic heat of reaction was supplied by the co-current flow of a hot gas in the adjacent channel. The performance of the coupled reactor/heat exchange system was evaluated by varying several parameters such as heating side gas velocity and temperature, width of the channel, weight of the catalyst, reactor inlet temperature, and inlet flow rate.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267446

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 12872–12880

Titre :	Modeling the cytotoxicity of cisplatin
Type de document :	texte imprimé
Auteurs :	Vishnu Sresht, Auteur ; Jayesh R. Bellare, Auteur ; Santosh K. Gupta, Auteur
Année de publication :	2012
Article en page(s) :	pp. 12872–12880
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Cytotoxicity Cisplatin
Résumé :	Cisplatin has been the mainstay of chemotherapeutic efforts against several types of cancers for over 30 years. However, there is still much that is unknown regarding its mechanism of action. The several serious side effects of cisplatin therapy and the lack of consensus regarding the ideal dosage regimen necessitate the development of a quantitative model for cisplatin action. A first-level mathematical model is presented for the cytotoxicity of cisplatin which predicts the survival of cancer cells when subjected to a given dose of this antitumor drug. This model comprises of (i) an uptake model that describes the movement of cisplatin molecules from the extracellular medium to the cell nucleus and the formation (and repair) of cisplatin−DNA adducts and (ii) a tolerance model that relates the quantity of cisplatin−DNA adducts formed inside the cell nuclei in a tumor to the fraction of tumor cells that are killed. The predictions of the model are in good agreement with in vitro experimental data obtained for carcinoma cell lines. To the best of our knowledge, this is the first model combining the uptake of cisplatin (consistent with the biochemical mechanism of action) with cell death (based on cisplatin−DNA adducts). It predicts a Pareto-type set of dosage regimen (dosage, Cext, vs exposure time, texp) of cisplatin to obtain a desired chemotherapeutic efficacy. Some reported patient-data is consistent with this prediction
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie102360e

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 12865–12871

Titre :	Evaluation of the effect of the concentration of CO2 on the overall reactivity of drop tube furnace derived indian sub - bituminous coal chars during CO2/O2 combustion
Type de document :	texte imprimé
Auteurs :	V. Saravanan, Auteur ; R. Shivakumar, Auteur ; Jayanti, S., Auteur
Année de publication :	2012
Article en page(s) :	pp. 12865–12871
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Nonisothermal Thermogravimetric Derived
Résumé :	A nonisothermal thermogravimetric analysis technique was used to evaluate the effect of CO2 concentration on the overall reactivity of Indian coal chars during CO2/O2 combustion. The study was carried out for the drop tube furnace derived chars of three Indian sub-bituminous coals from different sources. The selected coal char samples were combusted in different CO2/O2 molar volume combinations, namely, 80:20, 60:40, 40:60, 20:80, and 0:100 (pure O2) so that the effect of the concentration of CO2 on the overall reaction rate could be quantified. The Arrhenius constants (E and A) were determined using the random pore model. The concept of weighted mean activation energy was used to account for the multi-Arrhenius linearities. Empirical equations were proposed to evaluate the Arrhenius constants in terms of the mole fraction of CO2 for the overall reaction rate.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie1019358

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 23 (Décembre 2011) . - pp. 12847-12864

Titre :	Kinetic mechanisms of cholesterol synthesis : a review
Type de document :	texte imprimé
Auteurs :	Tapobrata Panda, Auteur ; Tanmay Basak, Auteur ; Ganesan Saraswathi, Auteur
Année de publication :	2012
Article en page(s) :	pp. 12847-12864
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Kinetics
Résumé :	Increased levels of cholesterol lead to critical health risk factors such as hypercholesterolemia and atherosclerosis in the human system. Regulation of cholesterol synthesis in mammals, especially in humans, is required for a healthy lifestyle. Cholesterol synthesis from acetyl Co-A in liver involves more than 10 enzymes, beginning with acetoacetyl Co-A thiolase, to desmosterol reductase. Among these, 3-hydroxy-3-methylglutaryl-Coenzyme A reductase (HMGR) could be involved in the rate-determining step of cholesterol synthesis. Statins are used to control HMGR. Because statins possess many side effects, an alternate drug for hypercholesterolemia with minimum or no side effects is in great demand. The first and foremost step in drug design is to select a suitable drug target, most likely an enzyme inhibitor. In this regard, an in-depth study of the kinetics of the enzymes involved in cholesterol synthesis is required for a preferred drug target, which, in turn, requires a thorough knowledge of the mechanisms involved in each step of cholesterol synthesis. This communication gives an overview of the mechanisms and kinetics of the key enzymatic reactions involved in the cholesterol synthesis pathway in different organisms.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25267443

Industrial & engineering chemistry research / Paul, Donald R. . Vol. 50 N° 23

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