Catalogue en ligne Bibliothèque Ecole Nationale Polytechnique d'Alger

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7697–7700

Titre :	Revisiting the liu − silva − macedo model for tracer diffusion coefficients of supercritical, liquid, and gaseous systems
Type de document :	texte imprimé
Auteurs :	Ana L. Magalhães, Auteur ; Simao P. Cardoso, Auteur ; Bruno R. Figueiredo, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7697–7700
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Liquid Gaseous Systems
Résumé :	This work comprises two main purposes: to present the largest database of tracer diffusion coefficients ever published, comprehending 5279 experimental points and 296 binary systems, and provide the necessary Lennard-Jones diameter and energy, and the interaction parameter of the Liu−Silva−Macedo correlation (TLSMd), since it affords reliable and very good results for all systems studied (the global deviation found was 3.89%). For comparison, the well-known equations of Dymond−Hildebrand−Batschinsky, Zhu and co-workers, and Tyn−Calus have been adopted.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie1009475

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7693–7696

Titre :	Preparation of rutile titanium dioxide white pigment via doping and calcination of metatitanic acid obtained by the NaOH molten salt method
Type de document :	texte imprimé
Auteurs :	Yong Wang, Auteur ; Jie Li, Auteur ; Lina Wang, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7693–7696
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Molten salt Calcining Doping Pigments Preparation
Résumé :	Rutile titanium dioxide (TiO2) white pigment has been prepared by doping and calcination of metatitanic acid (H2TiO3) obtained by the NaOH molten salt method. It was found that the properties of the rutile TiO2 sample prepared were improved by adding K2O, P2O5, Al2O3, and rutile nuclei. The X-ray diffraction (XRD) results show the rutile content of the rutile TiO2 sample prepared is 97%, and scanning electron microscopy (SEM) results show that the rutile TiO2 particles prepared have well-shaped morphology and narrow particle size distribution. The purity and color performance of the rutile TiO2 sample prepared approached the commercial TiO2 pigment standards.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23109349

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7687–7692

Titre :	Critical analysis of maxwell’s equal area rule : implications for phase equilibrium calculations
Type de document :	texte imprimé
Auteurs :	Karthikeyan Rajendran, Auteur ; R. Ravi, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7687–7692
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Phase Equilibrium
Résumé :	The fundamental flaws inherent in Maxwell’s equal area rule are analyzed. Using an alternative principle that overcomes the limitations of Maxwell’s rule, general equations are derived for determining the saturation pressure and other properties associated with the liquid−vapor phase transition given an arbitrary equation of state. The equivalence of the equation for saturation pressure to those available in the literature is proved. It is found that the alternative principle predicts saturation pressures that are significantly different from those calculated using Maxwell’s rule. These results are based on numerical studies on three different equations of state and fifteen substances. Similar results are obtained for the vaporization entropy as well.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100571m

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7685–7686

Titre :	Direct sulfonation of methane to methanesulfonic acid
Type de document :	texte imprimé
Auteurs :	Ahmad Shaabani, Auteur ; Rahim Ghadari, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7685–7686
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Methane Acid
Résumé :	Direct sulfonation of methane to methanesulfonic acid with chlorosufonic acid in the presence of Ce4+ as a catalyst was investigated. Oxygen was found to be an important component for the regeneration of the catalyst. The influence of CH4 to O2 ratio on yield of reaction was examined, too.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9015733

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7678–7684

Titre :	Equation of State for the Phase Behavior of Carbon Dioxide−Polymer Systems
Type de document :	texte imprimé
Auteurs :	Hun Yong Shin, Auteur ; Jianzhong Wu, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7678–7684
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Thermodynamic Multicomponent Solutions
Résumé :	We proposed a hybrid equation of state for CO2−polymer systems that utilizes the Peng−Robinson (PR) equation of state for the molecular excluded-volume effects and the van der Waals attractions, and equations from the statistical associating fluid theory (SAFT) for the polymer intrachain correlations and for the short-ranged forces due to weakly polar or association interactions. The numerical performance of the new equation of state was tested by its application to correlating the PVT behavior of pure CO2, including both the vapor−liquid coexistence densities, the vapor pressure, and the specific density of condensed CO2 at near-critical and supercritical conditions, and to the volumetric properties of high molecular weight alkanes and a few representative polymers. With the parameters from the original PR equation of state for nonpolar monomeric fluids and additional ones to account for the solvent polarity and the solute degree of polymerization, the new equation of state was successfully used to calculate the phase behavior of CO2−polymer systems, including the vapor−liquid equilibria of ternary systems.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100903f

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7671-7677

Titre :	Systematic study of the simple predictive approaches for thermodynamic and transport properties of multicomponent solutions
Type de document :	texte imprimé
Auteurs :	Jia-Zhen Yang, Auteur ; Jian-Guo Liu, Auteur ; Jing Tong, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7671-7677
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Transport properties
Résumé :	The densities, viscosities, and conductivities were measured for the ternary solution NaCl + urea + H2O, the quintuple solution NaCl + Na2SO4 + KCl + K2SO4 + H2O, and their binary subsystems at 298.15 K. The results together with the densities, viscosities, and conductivities of multicomponent solutions reported in the literature were used to study the predictability of the Young’s rule for density and conductivity, the rule of Patwardhan and Kumar for density, Hu’s equation for the viscosity of mixed electrolyte solutions based on the Eyring’s absolute rate theory and the rule of Patwardhan and Kumar, and the semiideal solution theory for thermodynamic and transport properties. The results show that all the tested equations can provide comparable and accurate predictions for the densities of multicomponent electrolyte solutions. The semiideal solution theory is applicable to the aqueous solutions of electrolytes and nonelectrolytes, and its predictions for the densities of the examined solutions are in nice agreement with the experimental results. The simple equation based on Eyring’s absolute rate theory and the rule of Patwardhan and Kumar and the semiideal solution theory can provide nice predictions for the viscosity of the tested electrolyte solutions. The predictions for the viscosity of the ternary solution NaCl + urea + H2O by the semiideal solution theory are also in accordance with the measured viscosities. The semiideal solution theory can provide better predictions for the conductivities of the tested electrolyte solutions than the extended Young’s rule, and their predictions are both in good agreement with the experimental results. The advantages of the semiideal solution theory are briefly discussed and reviewed.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23109345

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7666–7670

Titre :	Density and conversion in biodiesel production with supercritical methanol
Type de document :	texte imprimé
Auteurs :	A. Velez, Auteur ; P. Hegel, Auteur ; G. Mabe, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7666–7670
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Biodiesel Production
Résumé :	The densities of reacting mixtures of vegetable oils + methanol were measured by loading a closed vessel with a known amount of an oil/alcohol mixture of a given molar ratio. For each studied condition, the mixture was brought to a temperature at which the system became homogeneous. The isochoric (constant-volume) relation between temperature and pressure at this particular density and composition was recorded. In the temperature range of 550−630 K, a high conversion of the oil to the corresponding fatty esters and glycerin was obtained. The densities of sunflower oil with methanol for two different alcohol/oil ratios, namely, 40:1 and 25:1, were measured. Densities of coconut oil + methanol and methyl oleate + methanol mixtures were also measured. The effect of global density on conversion was studied at long reaction times (3−4 h). Strong evidence of the phase transitions of the reacting mixtures, from heterogeneous to homogeneous, was obtained from the experimental results.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100670r

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7660–7665

Titre :	Evaluation of fuel properties of butanol − biodiesel − diesel blends and their impact on engine performance and emissions
Type de document :	texte imprimé
Auteurs :	Rakhi N. Mehta, Auteur ; Mousumi Chakraborty, Auteur ; Pinakeswar Mahanta, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7660–7665
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Fuel properties Biodiesel Engine
Résumé :	Present work deals with the development of butanol−diesel−biodiesel blends to substitute for petrodiesel. These blends were tested for physical stability and various fuel properties conforming to ASTM standards. Subsequently engine performance and emission tests were conducted with each blend. Observations revealed the blends to be thermally and physically stable, and they showed good resemblance to the properties of diesel, with the exception of flash point only. Brake power showed marginal decrease and fuel consumption an increase in the range of 4.9%−10.7% as compared to diesel for identical performance. Exhaust gas temperature showed a drop in the range of 3.3%−9.4% due to quenching effect of butanol, whereas brake thermal efficiency showed a reduction of 6.3%−10% to that over petrodiesel. Exhaust gas emissions showed a significant decrease in CO (42%) at medium and higher loads, whereas NO showed an average increase of 2.4%−11% as compared to diesel.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie1006257

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7654–7659

Titre :	Empirical regularity of the thermal pressure coefficient for dense fluids
Type de document :	texte imprimé
Auteurs :	Zhi-Yong Zeng, Auteur ; Yuan-Yuan Xu, Auteur ; Xiao-Sen Li, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7654–7659
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Thermal Pressure
Résumé :	In this paper, an empirical regularity has been proposed for dense fluids, namely, that the thermal pressure coefficient is a near-parabola function of pressure. The regularity has been tested with experimental data for both associating and nonassociating compounds. The applicable ranges have also been investigated widely. It is found that the regularity holds well from the freezing temperature to critical temperature, and no obvious limits were found for pressure and compound type. Moreover, parameters of the thermal pressure coefficient expression were regressed from experimental data for n-alkanols, and the statistical results show it is an accurate correlation equation. Further, on the basis of the Lennard-Jones (12−6) potential function, the theoretical analysis was given to confirm the existence and uniqueness of the peak point for Lennard-Jones fluids.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100271c

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7646–7653

Titre :	Application of infinite dilution activity coefficients for determining binary equation of state parameters
Type de document :	texte imprimé
Auteurs :	Christian S. Schacht, Auteur ; Lawien Zubeir, Auteur ; Theo W. de Loos, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7646–7653
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Binary Equation
Résumé :	Infinite dilution activity coefficients can be determined relatively fast from several experimental techniques. Literature values for the infinite dilution activity coefficients are used to determine a binary interaction parameter of the perturbed-chain polar statistical associating fluid theory (PCP-SAFT) equation of state. The model is, subsequently, applied to the full concentration range of binary mixtures, and the results are compared to experimental data from literature. The applicability of the method is demonstrated for examples involving polar, associating, and polymeric components. It is confirmed that the parametrization allows for extrapolations in temperature. In combination with a group-contribution model for the estimation of infinite dilution activity coefficients (e.g., modified UNIFAC(Do)), the equation of state can be used to predict vapor−liquid equilibria of mixtures.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100259e

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7638–7645

Titre :	Flow characteristics in a jetting fluidized bed with acoustic assistance
Type de document :	texte imprimé
Auteurs :	Qingjie Guo, Auteur ; Chongdian Si, Auteur ; Zhang, Jian, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7638–7645
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Acoustic Fluidized Bed
Résumé :	A jetting fluidized bed with acoustic assistance was employed to investigate the jet penetration depth and particle concentration profiles using an optical fiber probe. One type of FCC and two types of quartz sand particles were used as bed materials in this study. Experimental results indicated that the jet penetration depth is increased with increasing fluidizing number, jet nozzle diameter, and jet gas velocity, respectively. The jet penetration depth is decreased with an increase in particle diameter and in particle density. The semitheoretical correlations were developed to predict the jet penetration depth with and without the sound assistance. In the bubbling region, particle concentration increased with an increase in sound pressure level, which had a maximal value at a sound frequency of 150 Hz. The sound excitation had a slight influence on the particle concentration profiles in the jetting region and dense-phase particle compression region.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9016573

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp.7631–7637

Titre :	Dynamics of transitional phase inversion emulsification : effect of addition time on the type of inversion and drop size
Type de document :	texte imprimé
Auteurs :	Fatemeh Jahanzad, Auteur ; Dimitris Josephides, Auteur ; Ali Mansourian, Auteur
Année de publication :	2010
Article en page(s) :	pp.7631–7637
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Résumé :	Emulsification processes are very sensitive to the time scale during which the dispersed phase is introduced into the continuous phase. A series of experiments were conducted across a transitional phase inversion path, which often leads to formation of nanoemulsions, with the speed of incorporation of the second phase (water) into the first phase (oil) being altered. The optimum condition could only be achieved if the optimum composition was maintained for a critical time. A slow addition (addition time > 60 s) of water to the oil allows the transitional phase inversion to become operative, leading to formation of sub-micrometer droplets. A very fast addition of the water phase (<5.0 s) caused the catastrophic phase inversion mechanism to become dominant, leading to formation of rather large drops. In the intermediate range of addition time, 20−40 s, both inversion mechanisms have contributed to drop formation, at least locally, and as a result skewed or bimodal drop size distributions were formed. The results indicate that while spontaneous emulsification is fast, it is not instantaneous. At a low surfactant concentration, the droplet size was only slightly affected by the rate of addition.
Note de contenu :	Transitional Phase
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901577f

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7620–7630

Titre :	Vapor − liquid equilibria of acid gas − aqueous ethanolamine solutions using the PC - SAFT quation of state
Type de document :	texte imprimé
Auteurs :	Khashayar Nasrifar, Auteur ; Amir H. Tafazzol, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7620–7630
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Acid Gas Aqueous
Résumé :	Using the perturbed-chain statistical associating fluid theory (PC-SAFT), the vapor pressure, saturated liquid density, and heat of vaporization for monoethanolamine (MEA), diethanolamine (DEA), and methyldiethanolamine (MDEA) were calculated. PC-SAFT accurately described the properties of the pure ethanolamines along the coexistence curve. Then, the vapor−liquid equilibria (VLE) of the aqueous ethanolamine solutions were calculated by temperature-independent binary interaction parameters. Using the binary interaction parameters for the systems DEA + water, DEA + methanol, and methanol + water, the VLE of the ternary system DEA + water + methanol was predicted. The results indicated that PC-SAFT successfully described the equilibrium properties of the aqueous ethanolamine solutions. Finally, the solubilities of carbon dioxide and hydrogen sulfide in the aqueous ethanolamine solutions were predicted and compared to the experimental data. While no adjustable parameters were used, PC-SAFT reasonably described the solubility data.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901181n

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7610–7619

Titre :	Calculation of critical points in gas − condensate mixtures under the influence of magnetic fields
Type de document :	texte imprimé
Auteurs :	Wilson A. Canas-Marín, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7610–7619
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Gas Magnetic fields
Résumé :	The mathematical conditions representing the gas−liquid critical points of multicomponent mixtures are used to compute the gas−liquid critical points of diamagnetic gas−condensate fluids of interest to the oil industry, where the effect of a static magnetic field on calculated critical points is studied for the first time. Magneto-chemical fugacity derivatives, required to fulfill the quadratic and cubic forms of the Helmholtz free energy at the critical points, have been obtained from a recently developed theory of phase equilibria in diamagnetic multicomponent fluids and numerical differentiation (Canas-Marin, W. A.; Ortiz-Arango, J. D.; Guerrero-Aconcha, U. E.; Lira-Galeana, C. AIChE J. 2006, 52 (8), 2887−2897). Results in diamagnetic synthetic gas−condensate mixtures show that a magnetic field can increase or decrease the critical points depending on mixture composition and the extent of the applied magnetic field. For mixtures rich in heavy diamagnetic substances (i.e., hydrocarbon oils), the critical points have an initial tendency to decrease up to a certain value of the field and then to increase with the applied magnetic field. If high amounts of light diamagnetic components are present (i.e., gases), the critical properties always increase with the applied field. The effect of the applied magnetic field on the stability limit of these mixtures is also studied in detail.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900939y

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7605–7609

Titre :	Modeling kinetics of Cd, Pb, and Zn vaporization during municipal solid waste bed incineration
Type de document :	texte imprimé
Auteurs :	Abhishek Asthana, Auteur ; Quentin Falcoz, Auteur ; Philippe Sessiecq, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7605–7609
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Modeling Kinetics
Résumé :	The fate of heavy metals contained in municipal solid waste is of major concern in the incineration process. This study is the first attempt to analyze the kinetic behavior of Cd, Pb, and Zn in a waste bed burning on the grate of an incinerator. The vaporization rates of the three heavy metals were derived from laboratory experiments. The kinetic law was then introduced into Garbed-ss, a mathematical model of the on-grate incineration of a refuse bed. Results show that the calculated vaporization of the three metals is fast, proceeds to nearly full completion, occurs at the pyrolysis front, and is indeed controlled by the thermal degradation of the waste. Alhough in agreement with thermodynamic calculations, the vaporization of lead and zinc seems to be overestimated. The model would be improved by accounting for the initial physical and chemical speciation of the heavy metals in the waste feed.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100181x

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp 7597–7604

Titre :	Modeling on - grate MSW incineration with experimental validation in a batch incinerator
Type de document :	texte imprimé
Auteurs :	Abhishek Asthana, Auteur ; Yannick Ménard, Auteur ; Philippe Sessiecq, Auteur
Année de publication :	2010
Article en page(s) :	pp 7597–7604
Note générale :	Industrail chemistry
Langues :	Anglais (eng)
Mots-clés :	Solid waste incineration
Résumé :	This Article presents a 2-D steady-state model developed for simulating on-grate municipal solid waste incineration, termed GARBED-ss. Gas−solid reactions, gas flow through the porous waste particle bed, conductive, convective, and radiative heat transfer, drying and pyrolysis of the feed, the emission of volatile species, combustion of the pyrolysis gases, the formation and oxidation of char and its gasification by water vapor and carbon dioxide, and the consequent reduction of the bed volume are described in the bed model. The kinetics of the pyrolysis of cellulosic and noncellulosic materials were experimentally derived from experimental measurements. The simulation results provide a deep insight into the various phenomena involved in incineration, for example, the complete consumption of oxygen in a large zone of the bed and a consequent char-gasification zone. The model was successfully validated against experimental measurements in a laboratory batch reactor, using an adapted sister version in a transient regime.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100175e

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7589–7596

Titre :	Modeling of highly nonideal systems : 2. prediction of high pressure phase equilibria with the group contribution NRTL - PR EoS
Type de document :	texte imprimé
Auteurs :	Evelyne Neau, Auteur ; Joan Escandell, Auteur ; Christophe Nicolas, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7589–7596
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Nonideal Systems
Résumé :	The purpose of this study is to propose a simple cubic equation of state for the prediction of phase equilibria in highly non ideal systems. The NRTL-PR equation of state is based on the association of the Peng−Robinson EoS and the generalized NRTL model developed in the first part of this work. This model, which derives from the lattice two-fluid theory, was specially developed to take account for the differences in size and shape between mixture components. The main advantage of the resulting NRTL-PR equation of state is to yield a simple and predictive model, depending on very few interaction parameters. In addition, it also allows satisfactory predictions of excess enthalpies, liquid−vapor and liquid−liquid equilibria occurring in mixtures formed by very asymmetric compounds, such as hydrocarbons, water, and ethylene glycols.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie101266x

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7580–7588

Titre :	Modeling of highly nonideal systems : 1. a generalized version of the NRTL equation for the description of low - pressure equilibria
Type de document :	texte imprimé
Auteurs :	Evelyne Neau, Auteur ; Joan Escandell, Auteur ; Christophe Nicolas, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7580–7588
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Nonideal systems
Résumé :	The topic of the present work is the development of a simple model for the description of phase equilibria occurring in nonideal systems, such as those containing size-asymmetric components or mixtures made of polar or associating compounds with hydrocarbons, that are capable of strong demixing. The generalized NRTL model presented in this first part derives from the lattice two-fluid theory and differs from the original model by considering the size asymmetry of mixture components; results obtained for the modeling of phase equilibria in hydrocarbon, polar, and highly immiscible systems are compared with other literature models, such as the van Laar, NRTL, and UNIQUAC models. In the second part of this work, this model is associated with the Peng−Robinson EoS using the EoS/GE approach based on a generalized reference state, and a new group contribution is proposed for the prediction of the binary interaction parameters.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100121c

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7574-7579

Titre :	Selective adsorption of Cd(II) and Zn(II) ions by nano - hydrous manganese dioxide (HMO) - encapsulated cation exchanger
Type de document :	texte imprimé
Auteurs :	Shunli Wan, Auteur ; Xin Zhao, Auteur ; Lu Lv, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7574-7579
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Cation exchanger Adsorption
Résumé :	A novel hybrid adsorbent HMO-001 was fabricated by impregnating nanosized hydrous manganese dioxide (HMO) onto a porous polystyrene cation exchanger resin (D-001) for enhanced removal of Cd(II) and Zn(II) ions from waters. The immobilized sulfonate anions covalently bound to the D-001 polymeric matrix are supposed to result in preconcentration and enhanced permeation of both target metal ions for favorable adsorption by HMO. Batch and column adsorption runs demonstrated that HMO-001 exhibited highly preferable Cd(II) and Zn(II) retention from waters in the presence of competing Ca(II) ions at much greater levels. The exhausted adsorbent particles are amenable to efficient regeneration by 2% HCl solution without any HMO loss during operation.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23109332

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7563–7573

Titre :	Thermodynamic and experimental analyses of the three - stage calcium looping process
Type de document :	texte imprimé
Auteurs :	Shwetha Ramkumar, Auteur ; Liang-Shih Fan, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7563–7573
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Thermodynamic Analyses
Résumé :	Clean-coal technologies that include carbon dioxide and sulfur capture during the production of electric power, liquid fuels, and hydrogen represent a major thrust area. The calcium looping process (CLP) is one such technology that is being developed to convert syngas obtained from coal gasification to hydrogen using a regenerable calcium oxide sorbent. It integrates the water−gas shift reaction with in situ carbon dioxide, sulfur, and halide removal at high temperatures while eliminating the need for a water−gas shift catalyst and reducing the overall footprint of the hydrogen production process. The CLP comprises three reactors: the carbonation reactor, where the thermodynamic constraint of the water−gas shift reaction is overcome by the constant removal of the carbon dioxide product and high-purity hydrogen is produced with contaminant removal; the calciner, where the calcium sorbent is regenerated and a sequestration-ready carbon dioxide stream is produced; and the hydrator, where the calcined sorbent is reactivated to improve its recyclability. In this article, the reaction chemistry occurring in the three calcium looping reactors and the performance of the reactors at various process conditions are presented through thermodynamic and experimental analyses. High-purity H2 with less than 1 ppm of H2S is obtained in the carbonation stage at a stoichiometric steam-to-carbon ratio at high pressures. Although calcination of the sorbent under realistic conditions causes severe sintering and a loss in reactivity, sorbent reactivation by hydration is effective in restoring sorbent reactivity.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100846u

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7550–7562

Titre :	Enabling low - cost CO2 capture via heat integration
Type de document :	texte imprimé
Auteurs :	Ryan P. Lively, Auteur ; Ronald R. Chance, Auteur ; William J. Koros, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7550–7562
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Heat Integration
Résumé :	Hollow fiber sorbents in rapid thermal swing mode, packed bed solid sorbents in thermal swing mode, hollow fiber membranes, monoethanolamine-based liquid amines, and chilled ammonia CO2 sorption systems are compared on an energetic basis for CO2 capture from coal-fired power plants. The systems are compared on an intrinsic heat and auxiliary basis both with and without plantwide heat integration efforts. Without heat integration, every technology considered was shown to be highly parasitic, consuming between 1.0 and 4.0 GJ/(ton of CO2 captured) (effectively between 40 and 100% parasitic, depending on plant efficiencies). When heat integration strategies are considered, such as utilizing feedwater preheating heat flows (without disrupting plant operation) and utilizing heats generated during CO2 compression, the overall parasitic nature of the technologies decreases dramatically. Namely, chilled ammonia and zeolite MFI-based fiber sorbents consume approximately 0.07 and 0.13 GJ/(ton of CO2 captured), respectively. The overall energetic analysis strongly suggests that CO2 capture systems must be highly integrated with the plant systems for successful widespread deployment as retrofits to large power plants.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100806g

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7541–7549

Titre :	Competitive adsorption of C20 − C36 linear paraffins on the amorphous microporous silica − alumina ERS-8 in vapor phase and liquid phase
Type de document :	texte imprimé
Auteurs :	Ben Li, Auteur ; Vincenzo Calemma, Auteur ; Chiara Gambaro, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7541–7549
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Microporous
Résumé :	Adsorption of C20−C36 linear paraffins on the amorphous microporous silica−alumina ERS-8 was studied at vapor phase and liquid phase conditions. Henry adsorption constants and low coverage adsorption enthalpies were determined using the pulse chromatographic method at temperatures between 90 and 370 °C in gas phase. The low coverage adsorption enthalpy increases linearly with carbon number with 5.5 kJ/mol per additional methyl group. Competitive adsorption in liquid and dense vapor phase conditions was studied by performing column breakthrough experiments with various binary C20−C36 n-paraffin mixtures diluted in short chain length alkane solvents or undiluted as bulk mixture, at temperatures ranging from 25 to 300 °C and pressures from 3 to 110 bar. Both the adsorption capacity and the selectivity are strongly temperature and pressure dependent. At low temperature and high pressure, all n-paraffins are adsorbed equally and no separation is possible. With increasing temperature and decreasing pressure, the density of the bulk phase decreases, and a transition from a pure liquid paraffin stream to a dense vapor stream occurs. In such conditions, longer n-paraffins are adsorbed preferentially compared to the shorter n-paraffins. The selectivity increases with increasing difference in chain length between the adsorbing n-paraffins.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100728h

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7530–7540

Titre :	Ionic liquids for aromatics extraction. present status and future outlook
Type de document :	texte imprimé
Auteurs :	G. Wytze Meindersma, Auteur ; Antje R. Hansmeier, Auteur ; Andre B. de Haan, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7530–7540
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Ionic Liquids
Résumé :	Ionic liquids (ILs) can be used to replace conventional solvents in liquid−liquid extractions of aromatic hydrocarbons. An IL-based extraction process requires fewer process steps and less energy consumption, provided that the mass-based aromatic distribution coefficient and/or the aromatic/aliphatic selectivity are higher than those of the current state-of-the-art solvents such as sulfolane. Only a small number of ionic liquids are able to combine higher mass-based distribution coefficients with selectivities comparable to or higher than those of sulfolane. The most suitable ILs from our analysis are [bmim]C(CN)3, [3-mebupy]N(CN)2, [3-mebupy]C(CN)3, and [3-mebupy]B(CN)4. The mass-based distribution coefficients with these four ILs for benzene, toluene, and p-xylene are factors of 1.2−2.5 higher than those with sulfolane, and the aromatic/aliphatic selectivities are up to a factor of 1.9 higher than with sulfolane. Based on the performed analysis, it can be concluded that industrial application of ILs for aromatics extraction has not yet materialized because only four of the total of 121 investigated ILs are considered suitable for aromatic/aliphatic separation. Most of the reported ILs do not provide higher mass-based aromatic distribution coefficients and/or higher aromatic/aliphatic selectivities than those achieved by conventional solvents such as sulfolane.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100703p

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7524–7529

Titre :	Selective adsorption of oxygen over argon in alkaline - earth - metal cation - exchanged zeolite X
Type de document :	texte imprimé
Auteurs :	Sunil A. Peter, Auteur ; Arun S. Moharir, Auteur ; Raksh V. Jasra, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7524–7529
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Adsorbed molecule Adsorption behavior Alkaline earth Cation-exchanged zeolites Chromatographic separations Electrostatic interactions
Résumé :	The separation of argon and oxygen from their gaseous mixture by adsorption is challenging because of the closeness of their molecular properties and, hence, adsorption behavior. In the present study, the potential of zeolite X with strontium as the extraframework cation as an oxygen-selective adsorbent for the separation and purification of argon is discussed. Equilibrium adsorption isotherms of oxygen and argon on calcium, strontium, and barium cation-exchanged zeolite X were measured at 288 and 303 K. The equilibrium adsorption capacity and selectivity for oxygen over argon were observed to be higher in zeolite X exchanged with alkaline-earth-metal cations than in NaX. Among these alkaline-earth-metal cation-exchanged zeolite X adsorbents, SrX showed the highest adsorption selectivity, in the range of 2.0 at 50 mmHg to 1.8 at 760 mmHg for oxygen over argon at 303 K. The increased selectivity for oxygen over argon in SrX is discussed in terms of the size, location, and effective partial charges on the extraframework cations present in the zeolite cavity and the subsequent electrostatic interactions between the adsorbed molecules and the extraframework cations. Strontium cation-exchanged zeolite X is also shown to be useful for the chromatographic separation and analysis of argon/oxygen mixtures.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100615e

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7515–7523

Titre :	Titanium silicate porous materials for carbon dioxide adsorption : synthesis using a structure directing agent, detemplation and inclusion of alkaline earth metal cations
Type de document :	texte imprimé
Auteurs :	José N. Primera-Pedrozo, Auteur ; Brenda D. Torres-Cosme, Auteur ; Meghan E. Clardy, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7515–7523
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Porous materials Adsorption
Résumé :	A titanium silicate variant named UPRM-5 was prepared using tetraethylammonium hydroxide as a structure-directing agent (SDA). Characterization of the material by scanning electron microscopy (SEM) and X-ray diffraction (XRD) techniques showed a homogeneous and crystalline solid powder phase, with unit cell dimensions of a = 6.8 Å, b = 11.7 Å, c = 13.4 Å, α = 102.9°, β = 92.8°, and γ = 91.1°. Successful detemplation was achieved via ion exchange with NH4Cl as evidenced by thermal gravimetric analysis (TGA) and Fourier transform infrared (FT-IR) spectroscopy data. Effective functionalization was obtained after ion exchanging the detemplated material using SrCl2 and BaCl2. These ion exchanged variants were also characterized using XRD and porosimetry techniques. Thermal-vacuum activation of Sr-UPRM-5 at 90 °C resulted in a material with a surface area of ca. 240 m2/g, while activation at higher temperatures resulted in low surface areas and plausible structural distortion. On the other hand, the barium variant exhibited the best thermal stability, with an average surface area on the order of 250 m2/g after employing activation temperatures up to 180 °C. The differences in thermal stability may be a result of structurally coordinated water. Adsorption of CO2 at 25 °C in Sr- and Ba-UPRM-5 materials activated at different temperatures also co-corroborated the aforementioned thermal stability observations in addition to what appears to be cation relocation. Fitting of the CO2 adsorption data with the Dubinin−Astakhov model revealed a heterogeneous surface, which was corroborated by isosteric heats of adsorption estimated from the uptake data. For low partial pressures, the observed CO2 adsorption capacities increased as follows: NH4-UPRM-5 < Sr-UPRM-5 < Ba-UPRM-5. Both the Sr- and Ba-UPRM-5 materials exhibited outstanding selectivity for CO2 over CH4, N2, and O2.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100331q?journalCode=iecred

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7504–7514

Titre :	Pervaporation separation of xylene isomers by hybrid membranes of PAAS filled with silane - modified zeolite
Type de document :	texte imprimé
Auteurs :	Xin Y. Qu, Auteur ; Hang Dong, Auteur ; Zhi J. Zhou, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7504–7514
Note générale :	Industial chemistry
Langues :	Anglais (eng)
Mots-clés :	Hybrid Membranes Zeolite
Résumé :	Silicalite-1 zeolite was modified with 3-aminopropyltriethoxysilane (APTES) and then loaded into poly(acrylic acid) sodium (PAAS) to prepare PAAS/silicalite-1 hybrid pervaporation membranes for the separation of xylene isomer mixtures. Characterization by Fourier transform infrared (FT-IR) and nuclear magnetic resonance (NMR) spectroscopies confirmed that chemical modification on the zeolite surface had taken place. Based on sorption equilibrium experiments, the diffusion coefficients of permeates in the membrane were obtained, and the order of the diffusion coefficients of xylene isomers was found to be Do < Dm < Dp. An investigation of the effects of the original versus modified zeolite loading on the pervaporation performance was performed. With the original zeolite, the permeation flux of the binary xylene mixtures showed little change, whereas the selectivity of the hybrid membrane exhibited some enhancement. After modification of the zeolite surface, the selectivity of the hybrid membrane was clearly improved, the permeation flux of the membrane decreased slightly, and the maximum separation factors of the p-/o-xylyne (αp/o) and p-/m-xylene (αp/m) mixtures were determined to be 2.62 and 2.68, respectively. The experimental results revealed that the modification promoted the compatibility of the PAAS and silicalite-1 zeolite interface.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100256u

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7497–7503

Titre :	CO2 and CH4 separation by adsorption using Cu - BTC metal − organic framework
Type de document :	texte imprimé
Auteurs :	Lomig Hamon, Auteur ; Jolimaitre, Elsa, Auteur ; Gerhard D. Pirngruber, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7497–7503
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Metal Organic Adsorption
Résumé :	Molecular simulations have shown that the metal−organic framework Cu-BTC (Cu3(BTC)2) is an interesting candidate for the separation of CO2 by adsorption. In this work, the first experimental binary and ternary adsorption data of CO2, CH4, and CO on the Cu-BTC are reported. These data are analyzed and compared with coadsorption models that are built from pure component isotherm data. Cu-BTC has a CO2/CH4 selectivity of 8 and a high delta loading (=difference between adsorption capacity under conditions of adsorption and desorption) and therefore appears to be a good compromise between zeolites, with high selectivity for CO2, but low delta loadings, and activated carbons, with high delta loadings, but low selectivity, for pressure swing adsorption applications.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie902008g

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7488–7496

Titre :	Prediction of infinite - dilution activity coefficients using UNIFAC and COSMO - SAC variants
Type de document :	texte imprimé
Auteurs :	Renan P. Gerber, Auteur ; Rafael de P. Soares, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7488–7496
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Chemical equilibriums.
Résumé :	Infinite-dilution activity coefficients (IDAC) can be used to predict, for example, the behavior of liquid−liquid equilibrium or to determine parameters for excess Gibbs free energy expressions like NRTL, Wilson, or UNIQUAC. For systems where limited (or no) experimental data are available, predictive tools as the well-known UNIFAC variations can be very helpful. An alternative approach is to use methods based on conductor-like screening model (COSMO). In this work, we have tested a modified UNIFAC model with a recent parameter set and three variations of the COSMO-SAC model. To compare the models, a database with a total of 748 IDAC experimental points was assembled with data from the literature and is available as Supporting Information. For nonaqueous solutions, the IDAC logarithm absolute average deviation for UNIFAC was 0.28, while it was 0.48 for a COSMO-SAC with parameters adjusted in this work. On the other hand, for aqueous systems, a COSMO-SAC with optimized parameters led to a deviation of 0.81 against 1.47 for the UNIFAC model tested.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901947m

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7484–7487

Titre :	Decolorization of synthetic wastewater containing azo dyes in a batch -operated rotating biological contactor reactor with the immobilized fungus phanerochaete chrysosporium
Type de document :	texte imprimé
Auteurs :	Kannan Pakshirajan, Auteur ; Sukhwinder Singh, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7484–7487
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Wastewater Biological Contactor
Résumé :	Biodecolorization of synthetic wastewater containing azo dyes, Direct Red-80 (DR-80) and Mordant Blue-9 (MB-9), both individually and together, using immobilized Phanerochaete chrysosporium in a batch-operated rotating biological contactor (RBC) reactor was investigated. Following initial startup of the RBC reactor, which took almost 1 month, results on dye decolorization and enzyme activities of lignin peroxidase (LiP) and manganese peroxidase (MnP) by the fungus were obtained. From experiments involving the individual dyes, decolorization efficiencies were found to be in the range of 94−100%, and from experiments in which the dyes were added together, the decolorization efficiencies of the dye mixture were between 77% and 97% at the end of 24 h. Results of LiP and MnP activities by the fungus revealed a strong role played by the enzymes in the dye decolorization process. As compared to the previous results obtained in batch shake flasks, the results in the present study revealed excellent performance of the bioreactor in decolorizing the wastewater containing the azo dyes.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie1007079

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7478–7483

Titre :	A Novel integrated approach to the enhanced production of polyhydrobutyrate with mixed culture in activated sludge
Type de document :	texte imprimé
Auteurs :	Fang Fang, Auteur ; Guo-Ping Sheng, Auteur ; Han-Qing Yu, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7478–7483
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Biomass
Résumé :	Polyhydrobutyrate (PHB) production from fatty acids by activated sludge is mainly influenced by the ratio of initial substrate concentration (S0) to initial biomass concentration (X0), ratio of chemical oxygen demand to nitrogen (COD/N), and aeration strength. In this work the PHB production by activated sludge was evaluated and enhanced using an integration of the response surface methodology (RSM) and a novel machine learning method, that is, support vector regression (SVR) coupled with the accelerating genetic algorithm (AGA). The results demonstrated that the SVR−AGA model was superior over the RSM model. With the SVR−AGA approach, a maximum PHB yield of 185.48 mg PHB/g VSS under the optimum conditions of S0/X0 of 0.286, COD/N of 144, and aeration intensity 0.004 m3/(L·h) was estimated. The verification experiment confirmed that the measured optimum PHB yield was close to that estimated by using the SVR−AGA approach. This work indicates that an integration of the SVR and AGA methods was an appropriate and effective approach for evaluating and enhancing the PHB production process by mixed cultures like activated sludge.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100297y

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7470–7477

Titre :	Combining kernel partial least - squares modeling and iterative learning control for the batch - to - batch optimization of constrained nonlinear processes
Type de document :	texte imprimé
Auteurs :	Yingwei Zhang, Auteur ; Yunpeng Fan, Auteur ; Pengchao Zhang, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7470–7477
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Non linear system Optimization Batchwise Learning Modeling Partial least squares
Résumé :	A new approach to the optimal control with constraints is proposed to achieve a desired end product quality, and a modified kernel partial least-squares (KPLS) is used to build the combining model of nonlinear processes. The particle swarm optimization algorithm is used to solve the optimal problem. The contributions of the article are as follows: The modified KPLS is proposed for the optimal control purpose, and the optimal manipulated variables are computed for the next batch run based on modified KPLS. The proposed approach is applied to a bulk polymerization of styrene batch process and fused magnesium furnace. Simulation results show the proposed approach is effective for predicting the control profile of next batch run.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=23109320

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7446–7469

Titre :	Optimal event point determination for short - term scheduling of multipurpose batch plants via unit - specific event - based continuous - time approaches
Type de document :	texte imprimé
Auteurs :	Jie Li, Auteur ; Christodoulos A. Floudas, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7446–7469
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Continuous time Batchwise Multipurpose installation Scheduling Short term
Résumé :	In the past two decades, three types of continuous-time models have been developed for the short-term scheduling of multipurpose batch plants: sequence-based, slot-based, and event-based models. Both slot- and event-based models require an iterative procedure proposed by Ierapetritou and Floudas ( Ind. Eng. Chem. Res. 1998, 37, 4341) to determine the number of event points or slots, which results in increased computational time and no optimal number of event points or slots in some cases. In this work, we first enhance the recently proposed three-index unit-specific event-based model developed by Shaik and Floudas ( Ind. Eng. Chem. Res. 2009, 48, 2947) and extend it to handle different wait policies. Then, we develop a general framework to obtain the optimal number of event points where an iterative procedure is employed to obtain the maximum number of event points and determine the critical intermediate states. The approach proposed by Janak and Floudas ( Comput. Chem. Eng. 2008, 32, 913) is used to obtain the minimum number of event points. Based on the maximum and minimum numbers of event points, we propose a branch-and-bound strategy to obtain the optimal number of event points. To accelerate convergence, techniques for task prefixing in the shortest path are proposed. Furthermore, we propose some criteria to determine which tasks to split over multiple event points and the maximum number of event points over which to continue them. Several examples with different intermediate storage requirements such as unlimited intermediate storage (UIS) and finite intermediate storage (FIS) are solved to illustrate the potential and computational efficiency of the proposed framework.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901842k

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7421–7445

Titre :	Control of chemical processes via output feedback controller networks
Type de document :	texte imprimé
Auteurs :	Shichao Xu, Auteur ; Jie Bao, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7421–7445
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Chemical Processes
Résumé :	Many modern chemical plants are complex systems consisting of a large number of process units. The interactions between these units often intensify the complexity of large scale plantwide systems and cause significant difficulties in plantwide process control. This paper aims to address these issues by developing a networked control approach. The plantwide process is modeled as a network of process units connected via mass and energy flow. A network of output feedback distributed controllers are then designed to control the process network. Using the concept of dissipativity, plantwide stability and global performance requirement are translated into dissipativity conditions for which each output feedback control system has to satisfy. This allows controllers to be designed and implemented independently. In this framework, the plantwide connective stability is established to ensure the stability of the plant even when communications between controllers break down. This leads to improved reliability and fault tolerance. The effectiveness of the proposed linear control approach is demonstrated in a case study of a process network that consists of a reactor and two multistage distillation columns.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901768q

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7412–7420

Titre :	Thermodynamic - analysis - based design and operation for boil - Off gas flare minimization at LNG receiving terminals
Type de document :	texte imprimé
Auteurs :	Chaowei Liu, Auteur ; Zhang, Jian, Auteur ; Qiang Xu, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7412–7420
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Thermodynamic Gas
Résumé :	The LNG (liquefied natural gas) receiving terminal is an important component of the entire LNG value chain. The handling of unloading BOG (boil-off gas) during LNG regasification at LNG receiving terminals significantly influences the BOG flare emission and energy consumption. In this work, thermodynamic-analysis-based design and operations are simultaneously considered to recover BOG with the minimum total energy consumption, a goal of which is to provide a cost-effective flare minimization strategy at LNG receiving terminals. A rigorous simulation-based optimization model and its solution algorithm are developed based on an LNG regasification superstructure. Case studies are used to demonstrate the efficacy of the developed methodology. The presented general optimization model and thermodynamic analysis also provide fundamental understandings of the LNG regasification process that are valuable for industrial applications.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie1008426

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7398–7411

Titre :	Design and control of a heat - integrated reactive distillation system for the hydrolysis of methyl acetate
Type de document :	texte imprimé
Auteurs :	Hao-Yeh Lee, Auteur ; Yi-Chen Lee, Auteur ; Chien, I-Lung, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7398–7411
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Hydrolysis Reactive Distillation System
Résumé :	There is increasing interest in the heat-integrated reactive distillation systems, lately. In this Article, two types of heat-integrated reactive distillation systems for the hydrolysis of methyl acetate are investigated. One type is to use the concept of internally heat-integrated distillation column (HIDiC) as applied to the reactive distillation system. Another type for the heat integration is to use a multieffect distillation concept by splitting the feed to enter into two smaller reactive distillation columns operated at different pressures. Rigorous simulation study has been conducted to compare the optimal flowsheet of the above two designs. It is found that, although the first design can save operating costs by 8.05%, due to the high cost of the compressor needed in the system, the total annual cost is 33.13% higher than that of the base design without heat integration. On the contrary, the multieffect distillation design not only saves operating cost by 15.19%, but also saves the total annual cost by 6.42%. The overall control strategy of this proposed heat-integrated design has also been developed. Only tray temperature control loops are needed to properly reject feed disturbances.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9016754

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7389–7397

Titre :	Modeling and simulation for control of the TEALARC liquified natural gas process
Type de document :	texte imprimé
Auteurs :	Finn Are Michelsen, Auteur ; Ivar Johan Halvorsen, Auteur ; Berit Floor Lund, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7389–7397
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Natural Gas Process
Résumé :	This article describes a dynamic, control relevant, mechanistic model of the TEALARC liquified natural gas process. The model is to be used for both steady-state and dynamic controllability analysis. The model therefore needs to be computationally light, but still include enough complexity such as to study the impact of capacity constraints on the control structure. Structured assumptions have been used to obtain simplified representations of gas/liquid flows and thermodynamic properties. The steady-state operating points of the dynamic model have been adapted to a given steady-state process design model. The paper demonstrates that the model is well suited for operability analysis. Steady-state and dynamic characteristics are illustrated.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901650e

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7371–7388

Titre :	Toward novel hybrid biomass, coal, and natural gas processes for satisfying current transportation fuel demands, 2 : simultaneous heat and power integration
Type de document :	texte imprimé
Auteurs :	Josephine A. Elia, Auteur ; Richard C. Baliban, Auteur ; Christodoulos A. Floudas, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7371–7388
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Hybrid Biomass Natural Gas
Résumé :	This paper, which is the second of a series of papers, presents an approach for the generation of a novel heat exchange and power recovery network (HEPN) for use with any large-scale process. A three-stage decomposition framework is introduced to sequentially determine the minimum hot/cold/power utility requirement, the minimum number of heat exchanger matches, and the minimum annualized cost of heat exchange. A superset of heat engine operating conditions is used to derive the heat engine design alternatives that produce the maximum amount of electricity that can be generated when there is complete integration with the process streams. Given the minimum utility loads and the appropriate subnetworks for each process flowsheet, the minimum number of heat exchanger matches is found for each subnetwork. Weighted matches and vertical heat transfer are used to distinguish among the heat exchanger sets, to postulate the appropriate set of matches that will yield the lower minimum annualized cost. Finally, a minimum annualized cost model was presented, which uses Aspen Plus process information to estimate the cost functions for a heat exchanger match and the overall heat transfer coefficient. The proposed model is then used to analyze the seven simulated process flowsheets detailed in the first part of this series of papers [Ind. Eng. Chem. Res. 2010, DOI: 10.1016/ie100063y]. Detailed case studies are presented for the three hybrid process flowsheets to highlight the key differences in the HEPN for each process.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100064q

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7343–7370

Titre :	Toward novel hybrid biomass, coal, and natural gas processes for satisfying current transportation fuel demands, 1 : process alternatives, gasification modeling, process simulation, and economic analysis
Type de document :	texte imprimé
Auteurs :	Richard C. Baliban, Auteur ; Josephine A. Elia, Auteur ; Christodoulos A. Floudas, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7343–7370
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Hybrid Biomass
Résumé :	This paper, which is the first part of a series of papers, introduces a hybrid coal, biomass, and natural gas to liquids (CBGTL) process that can produce transportation fuels in ratios consistent with current U.S. transportation fuel demands. Using the principles of the H2Car process, an almost-100% feedstock carbon conversion is attained using hydrogen produced from a carbon or noncarbon source and the reverse water-gas-shift reaction. Seven novel process alternatives that illustrate the effect of feedstock, hydrogen source, and light gas treatment on the process are considered. A complete process description is presented for each section of the CBGTL process including syngas generation, syngas treatment, hydrocarbon generation, hydrocarbon upgrading, and hydrogen generation. Novel mathematical models for biomass and coal gasification are developed to model the nonequilibrium effluent conditions using a stoichiometry-based method. Input−output relationships are derived for all vapor-phase components, char, and tar through a nonlinear parameter estimation optimization model based on the experimental results of multiple case studies. Two distinct Fischer−Tropsch temperatures and a detailed upgrading section based on a Bechtel design are used to produce the proper effluent composition to correctly match the desired ratio of gasoline, diesel, and kerosene. Steady-state process simulation results based on Aspen Plus are presented for the seven process alternatives with a detailed economic analysis performed using the Aspen Process Economic Analyzer and unit cost functions obtained from literature. Based on the appropriate refinery margins for gasoline, diesel, and kerosene, the price at which the CBGTL process becomes competitive with current petroleum-based processes is calculated. This break-even oil price is derived for all seven process flowsheets, and the sensitivity analysis with respect to hydrogen price, electricity price, and electrolyzer capital cost, is presented.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100063y

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7336–7342

Titre :	Characteristics of polyurethane elastomer blends with poly (acrylonitrile - co - butadiene) rubber as an encapsulant for underwater sonar devices
Type de document :	texte imprimé
Auteurs :	H. G. Im, Auteur ; K. R. Ka, Auteur ; C. K. Kim, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7336–7342
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Thermoplastic Elastomer
Résumé :	Thermoplastic polyurethane elastomer (TPU) is widely used as an encapsulant in undersea sonar devices. Since sonar encapsulants are filled with a paraffin oil to prevent the ingress of seawater into the transducer, encapsulant materials possessing a lower swelling ratio for seawater and paraffin oil, along with better mechanical strength than TPU after impregnation, are desirable. To fabricate polymeric materials for application in sonar encapsulants, TPUs prepared with poly(tetramethylene glycol) (PTMG) and methyldiphenyldiisocyanate (MDI) were blended with poly(acrylonitrile-co-butadiene) rubber (NBR) containing various amounts of acrylonitrile (AN). The swelling ratios of the TPU/NBR blends in seawater were all lower than that of TPU, regardless of the AN content of the NBR, and the swelling ratio gradually decreased with increasing AN content of the NBR. The TPU blend with NBR containing 43 wt % AN exhibited a lower swelling ratio than TPU in paraffin oil. In addition, the TPU/NBR43 blend exhibited enhanced mechanical strength, as compared to TPU after being impregnated with seawater and paraffin oil.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100975n

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7330–7335

Titre :	Sulfur poisoning and regeneration of NOx storage − reduction Cu/K2Ti2O5 catalyst
Type de document :	texte imprimé
Auteurs :	Qiang Wang, Auteur ; Jiahua Zhu, Auteur ; Suying Wei, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7330–7335
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Catalyst
Résumé :	A new Cu/K2Ti2O5 catalyst has been developed recently to remove NOx through the NOx storage−reduction (NSR) process. However, its NSR performance in the presence of sulfur has not been investigated. In this article, the sulfur poisoning of the NOx storage−reduction catalyst Cu/K2Ti2O5 and the corresponding deactivation mechanisms are reported for the first time. The effect of the sulfur concentration, adsorption/regeneration cycling tests, and temperature-programmed regeneration are studied. At low temperatures, the poisoning effect is negligible when the SO2 concentration is lower than 20 ppm, and the sulfated samples can be easily regenerated by 3.5% H2 at 550 °C. However, at high temperatures, the sulfur species are adsorbed on K+ sites to form K2SO4 and, consequently, induce a structure transformation from K2Ti2O5 to K2Ti6O13 nanoparticles. The structural change is reversible, and the sulfated catalyst can be regenerated by hydrogen at 650−700 °C.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie1009525

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7323–7329

Titre :	Novel pH - sensitive hydrogels prepared from the blends of poly(vinyl alcohol) with acrylic acid - graft - guar gum matrixes for isoniazid delivery
Type de document :	texte imprimé
Auteurs :	Anita G. Sullad, Auteur ; Lata S. Manjeshwar, Auteur ; Tejraj M. Aminabhavi, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7323–7329
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Hydrogels
Résumé :	A novel type of pH-sensitive hydrogel blend of poly(vinyl alcohol) with acrylic acid-graft-guar gum has been prepared. Microspheres with a size of 10 μm were produced by the water-in-oil (w/o) emulsification method for investigating the controlled release of an antituberculosis drug, isoniazid. These novel carriers were analyzed for surface morphology, size, effect of pH, swelling, drug loading, and in vitro release of isoniazid in pH 1.2 and 7.4 media. The kinetics of drug release was analyzed using empirical equations. Release times of the drug were increased to 8 h from its nascent plasma half-life of 0.5−1.6 h.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100389v

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7313–7322

Titre :	Effect of tolyltriazole on the corrosion protection of copper against ammonia and disinfectants in cooling systems
Type de document :	texte imprimé
Auteurs :	Ming-Kai Hsieh, Auteur ; David A. Dzombak, Auteur ; Radisav D. Vidic, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7313–7322
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Corrosion Copper
Résumé :	Tolyltriazole (TTA) has been widely used as a corrosion inhibitor for copper and copper alloy heat exchanger components in power plant cooling water systems. In this work the effectiveness of TTA protection in the presence of free chlorine, monochloramine, and ammonia was studied, in the context of using secondary treated municipal wastewater as cooling water. Results indicated that the corrosiveness of ammonia becomes negligible in the presence of TTA. Also, monochloramine represents a better disinfection agent in terms of copper corrosion protection by TTA than free chlorine. The packing density, film thickness, and number of layers of TTA adsorbed on the Cu surface were estimated from measurements and compared with estimates from other studies. It was found that copper can work as a catalyst for free chlorine to degrade TTA and that the surface packing density, film thickness, and number of layers increased in the presence of monochloramine.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100384d

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7303–7312

Titre :	Effect of Bimodality on the Adhesive Properties of Pressure Sensitive Adhesives : Role of Bimodal Particle Size and Molecular Weight Distributions
Type de document :	texte imprimé
Auteurs :	Gabriela E. Fonseca, Auteur ; Timothy F. L. McKenna, Auteur ; Marc A. Dubé, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7303–7312
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Adhesive Properties
Résumé :	A one-pot, two-step miniemulsion polymerization approach was successfully used to create poly(2-ethyl hexyl acrylate/methyl methacrylate/acrylic acid) pressure sensitive adhesives with well-defined and predictable bimodal particle size distributions (PSDs) or bimodal molecular weight distributions (MWDs). The resulting viscoelastic (shear storage and loss moduli) and adhesive properties (i.e., loop tack, peel strength, and shear strength) were tested and compared to monomodal distributions of either particle size or molecular weight along with bimodal distributions created by postpolymerization blending. The results indicated that in situ bimodal MWDs offered superior values of PSA properties when compared to either monomodal MWDs or postpolymerization blends. Viscoelastic analysis of the in situ bimodal MWD samples showed that the proposed approach can effectively vary the MWDs and cross-linking densities of the resulting PSAs, thus tailoring the final properties. In comparison, the in situ bimodal PSD latexes did not show significant differences in viscoelastic behavior, but they exhibited large differences in PSA properties.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100204x

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7294–7302

Titre :	A Green and efficient synthesis of ZSM - 5 using NaY as seed with mother liquid recycling and in the absence of organic template
Type de document :	texte imprimé
Auteurs :	Huihua Pan, Auteur ; Qunxiong Pan, Auteur ; Yuansheng Zhao, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7294–7302
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Organic template
Résumé :	A green and efficient route toward the synthesis of ZSM-5 is developed, which is characterized by using silica gel powder as silica source and NaY as seed, low synthesis H2O/SiO2 ratio, high zeolite yield, mother liquid recycling, and organic template free. ZSM-5 zeolite was synthesized with silica to alumina ratios from 30 to 70 under autogenous pressure using NaY as seed. By fine-tuning the chemical composition, ZSM-5 with high crystallinity was obtained. Compared with the conventional synthesis method using waterglass as silica source, this method considerably improves zeolite yield and silica source utilization. The synthesized samples were characterized by X-ray diffraction, nitrogen adsorption and desorption, scanning electron microscopy, X-ray fluorescence, NH3-temperature programmed desorption, and pyridine infrared spectrum analysis. Besides creating less waste, mother liquid recycling has a positive effect on crystallization rate and crystal morphology. Crystallization mechanisms for silica powder as silica source with and without mother liquid recycling were also discussed. Catalytic cracking results show that ZSM-5 prepared by this method is a promising catalytic material.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100191a

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7287–7293

Titre :	Bactericidal efficiency of silver nanoparticles deposited onto radio frequency plasma pretreated polyester fabrics
Type de document :	texte imprimé
Auteurs :	Vesna Ilic, Auteur ; Zoran Saponjic, Auteur ; Vesna Vodnik, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7287–7293
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Nanoparticles Polyester
Résumé :	The potential application of low-temperature radio frequency (RF) plasma for fiber surface activation in order to enhance the binding efficiency of colloidal silver nanoparticles onto the polyester fabrics and improve the stability of antibacterial effects was studied. Antibacterial activity and laundering durability were tested against gram-negative bacterium Escherichia coli and gram-positive bacterium Staphylococcus aureus. Plasma treatment positively affected the loading of silver nanoparticles as well as antibacterial activity and laundering durability of these textile nanocomposite materials. In spite of good laundering durability after five washing cycles, it was found that silver leached from the fabric into the bath during washing. Released silver from the washing effluent was efficiently removed by recycled wool-based nonwoven sorbent modified with hydrogen peroxide and biopolymer alginate.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie1001313

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7281–7286

Titre :	Liquid and supercritical carbon dioxide - assisted implantation of ketoprofen into biodegradable sutures
Type de document :	texte imprimé
Auteurs :	Randy D. Weinstein, Auteur ; Kenneth R. Muske, Auteur ; Sherrie-Ann Martin, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7281–7286
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Carbon Dioxide Biodegradable
Résumé :	In this study we explored the use of liquid and supercritical carbon dioxide for the creation of a sustained release drug delivery device. An anti-inflammatory (ketoprofen) was dissolved into carbon dioxide at various temperatures (25−55 °C) and pressures (65−300 bar) and then exposed to biodegradable braided sutures made of poly(lactide-co-glycolide) copolymers. The effect of temperature, pressure (and hence density), and exposure time were explored on the ability of the sutures to absorb ketoprofen. The diffusion of the drug into the suture was modeled, and diffusion coefficients were calculated. The amount of ketoprofen loaded into the suture increased with pressure and density and decreased with temperature; however, increasing temperature tended to speed up the absorption process.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901913x

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7263–7280

Titre :	Prediction of partition coefficients of plastic additives between packaging materials and food simulants
Type de document :	texte imprimé
Auteurs :	Guillaume Gillet, Auteur ; Olivier Vitrac, Auteur ; Stéphane Desobry, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7263–7280
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Plastic Additives
Résumé :	Partition coefficients, Ki,F/P, between liquids or food simulants, F, and amorphous regions of polymers, P, are important quantities to predict the sorption or desorption kinetics in various areas and in particular to predict the contamination of food by substances originating from food contact materials. This work extends an atomistic Flory−Huggins approach previously developed by us ( Ind. Eng. Chem. Res 2009, 48, 5285−5301) to predict Ki,F/P values for large solutes such as antioxidants, light stabilizers, and surface agents. Two extensions were particularly considered. The first extension aims at determining by isobaric molecular dynamics (MD) simulation the contribution of translational entropy in liquids with increasing polarity (isopropanol, ethanol, methanol, ethyl acetate, water) for large and flexible solutes representative of plastics additives. It was found to be higher than the partial molar volume of such solutes, independent of the considered alcohol and satisfactory estimated by the volume accessible to a hydrogen probe. The validity of the coarse-graining approximation for large flexible solutes (octadecane and octacosane) was tested by computing the radial distribution function from MD simulations. A simple correction was proposed to account for the partial overlapping at the coarse-grained level between F molecules and large flexible segments of solutes. The second major improvement extends the whole methodology to water and water−ethanol mixtures. Intrinsic limitations of the Flory−Huggins approximation to handle hydrogen bond cooperativity were overcame by reweighting contact energies in water and by introducing tabulated nonideal properties of water−ethanol mixtures. All predictions agreed well with previously published partitioning data as well as those generated by this study. From experimental values and theoretical considerations, the possibility to predict the contamination of food emulsions with water−ethanol mixtures is finally discussed.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9010595#aff1

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp 7257–7262

Titre :	A Pseudo second - order kinetic expression for dissolution kinetic profiles of solids in solutions
Type de document :	texte imprimé
Auteurs :	K. Vasanth Kumar, Auteur ; Issam A. Khaddour, Auteur ; Vinod K. Gupta, Auteur
Année de publication :	2010
Article en page(s) :	pp 7257–7262
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Kinetic Solids
Résumé :	A pseudo second-order kinetic expression was presented to explain the dissolution kinetics of solids in solution. The kinetic constant, initial dissolution rate, and theoretical saturation concentration according to pseudo second-order kinetic expression was defined. The proposed expression successfully represents the published dissolution kinetic profiles of alumina, digoxin, benzoic acid, lead chloride, and lecithin in solutions. A pseudo second-order kinetics based on fractional conversion successfully represents the dissolution kinetics of ulexite in ammonium acetate solutions. The pseudo second-order kinetics enabled the prediction of dissolution kinetics for higher residence time from experimental data obtained in relatively short time.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie1010228

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7239–7256

Titre :	Fuel processing for high - temperature high - efficiency fuel cells
Type de document :	texte imprimé
Auteurs :	Khaliq Ahmed, Auteur ; Karl Foger, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7239–7256
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Fuel Cells
Résumé :	Fuel processing for fuel cells has received considerable attention in the literature. However, most of the reported work focused on the production of hydrogen. With internal reforming fuel cells, the fuel processor can operate at relatively low temperatures to generate a mixture of gases containing hydrogen, methane, and the carbon oxides. The primary challenge for any fuel cell system is to select the most effective reforming scheme for a particular application considering factors such as electric efficiency, operating parameters, system complexity, and costs. In this paper we briefly review fuel processing technologies for fuel cells with particular emphasis on fuel pretreatment for internal reforming fuel cells, and discuss concepts and investigations we have pursued at Ceramic Fuel Cells, Ltd. (CFCL) on processing of gaseous and liquid hydrocarbons for application in CFCL’s solid oxide fuel cells.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100778g

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7234–7238

Titre :	Study on alkylation of toluene with tert - butanol over La2O3 - modified HY zeolite
Type de document :	texte imprimé
Auteurs :	Lin-bo Chen, Auteur ; Hong-jun Dong, Auteur ; Shi Li, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7234–7238
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Zeolite catalysts
Résumé :	Alkylation of toluene with tert-butanol was investigated over La2O3-modified HY zeolite catalysts in the microfixed bed reactor. The affect factors of conversion of toluene and the selectivity of tert-butyltoluene were studied. The main reaction products have been identified as p-tert-butyltoluene and m-tert-butyltoluene, La2O3 modified HY zeolite catalyst can significantly improve the selectivity of p-tert-butyltoluene. The result showed that 5% La2O3-modified HY zeolite catalyst was catalytic active (32.4% conversion of toluene), with para-selectivity near 82% at 473 K after 8 h. At the same time the catalysts were characterized by the X-ray diffraction (XRD) and Fourier transform infrared (FT-IR) spectroscopy. The FT-IR results showed that the modifier could increase the concentration of weak B acid of HY zeolite and obviously improve the selectivity of p-tert-butyltoluene.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100695k

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7227–7233

Titre :	Reactive ionic liquid media for the separation of propylene/propane gaseous mixtures
Type de document :	texte imprimé
Auteurs :	Alfredo Ortiz, Auteur ; Lara Maria Galan, Auteur ; Daniel Gorri, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7227–7233
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Ionic Liquid Gaseous Mixtures
Résumé :	Designed room temperature ionic liquids (RTILs) containing silver salt are presented as reactive media in separating propylene/propane gas mixtures. Solubilities of propylene and propane in the reactive media, silver tetrafluoroborate (AgBF4) dissolved in 1-butyl-3-methylimidazolium tetrafluoroborate (BmimBF4) and N-butyl-4-methylpyridinium tetrafluoroborate (BmpyBF4), were investigated as a function of silver ion concentration, temperature, and pressure. Equilibrium data were obtained working in a temperature range between 278 and 318 K and at pressures up to 6 bar. Propylene absorption was chemically enhanced in the silver-based RTILs and was considerably higher than that in the standard RTILs. Absorption of propane in the silver-based RTILs is based on physical interactions only. A simple mathematical model based on the formation of complex species with different stoichiometry has been developed in order to describe the total propylene absorption, and the model was validated with experimental data obtained working with different concentrations of silver salt (between 0.1 and 1 M). The model parameters, equilibrium constants (KEq,1 f(T) and KEq,2 f(T)), and enthalpies of complexation (ΔHr,1, ΔHr,2) were obtained. Thermal stability of the silver ions was analyzed and to be found dependent on the silver salt concentration. Complete regeneration of the reaction media was possible at a temperature of 313 K and 20 mbar of pressure.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100576r

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7210–7226

Titre :	Selective homogeneous oxidation system for producing hydroperoxides concentrate : kinetic simulation of catalytic oxidation of gas oils
Type de document :	texte imprimé
Auteurs :	Syed Mumtaz Danish Naqvi, Auteur ; Muhammad Ashraf Kamal, Auteur ; Fasihullah Khan, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7210–7226
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Modeling Gas oil Catalytic reaction Catalytic reaction Oxidation
Résumé :	Homogeneous production of hydroperoxides concentrate has been simulated via multivariate calibration of yield data, obtained during an earlier study [Naqvi and Khan Ind. Eng. Chem. Res. 2009, 48, 5642] made on the air oxidation of diluted gas oils in the presence of chemically generated redox couple Co(III)/Co(II). Principal component analysis has been applied to abstract dynamic hydroperoxides yield data that provides the basis for the simulation. A novel chemometric technique, inverse nonlinear principal component regression, has been introduced to simulate experimental yield profiles with exceptional accuracy (R2 = 0.9841). Simulated yield profiles have then been subjected to Levenberg−Marquardt method in order to estimate the rate constants for formation and decomposition of hydroperoxides. These estimations have permitted the development of two reasonably accurate multivariate global models that relate the specific rates, for formation (R2 = 0.8873) and decomposition (R2 = 0.9504) of hydroperoxides, to process and composition variables. Construction of such models allows the specific rates to be optimized so that the reactor could be operated at an oil conversion (up to ≈5%) that is almost proportional to the yield of hydroperoxides ensuring selectivity ≈88%.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100327m

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7201–7209

Titre :	Alkylation of isobutane /1 - butene on methyl - modified nafion / SBA - 16 materials
Type de document :	texte imprimé
Auteurs :	Wei Shen, Auteur ; Yi Gu, Auteur ; Hualong Xu, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7201–7209
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Acidic resin Nafion
Résumé :	Three-dimensional mesoporous SBA-16 silica materials were functionalized with perfluorosulfonic acidic resin Nafion using an impregnation method. The intrinsic polarity of the SBA-16 surface was tuned by grafting ethoxytrimethylsilane on its surface. Characterized by N2-physisorption, X-ray diffraction (XRD), and transmission electron micrographs (TEM), all the materials synthesized exhibited ordered three-dimensional Im3m mesoporous structure. Elemental analysis and water adsorption measured by an intelligent gravimetric analyzer (IGA) showed that trimethylsilane is grafted on the surface by capping the −OHs which enhance the hydrophobicity of SBA-16. Elemental analysis and potentiometric titration showed that Nafion resin was incorporated, revealing a three-dimensional mesoporous strong solid acid with a hydrophobic surface. The catalytic alkylation of isobutane/1-butene was thereafter evaluated on each material under specified conditions and compared with the one-dimensional Nafion/SBA-15 and commercial Nafion silica nanocomposite SAC-13. The catalyst with three-dimensional mesoporous channels was shown to outperform the one with one-dimensional channels. The higher activity of Nafion over methyl modified SBA-16 materials is related to the more hydrophobic surface of support.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie1001873

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7193–7200

Titre :	Dynamic modeling the anaerobic reactor startup process
Type de document :	texte imprimé
Auteurs :	Bai-Hang Zhao, Auteur ; Yang Mu, Auteur ; Fang Dong, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7193–7200
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Anaerobic Reactor
Résumé :	The startup of anaerobic reactors is a very important issue for their application in the treatment of wastewaters and solid wastes. However, very limited information is available about the quantitative and dynamic modeling of anaerobic reactor startup in the literature. In this work, by introducing a linear phenomenological equation into the IWA Anaerobic Digestion Model No. 1 (ADM1), we developed a model to describe the dynamic behavior of the startup of anaerobic reactors. The model was calibrated and verified using the experimental results of two anaerobic reactors: an upflow anaerobic sludge blanket (UASB) reactor fed with soybean processing wastewater and a continuously stirred tank reactor (CSTR) system with simulated municipal solid wastes as the substrate. The simulation results matched with the experimental data well, and the model could capture the variation trends of the components. This agreement demonstrates the rationality and validity of the established model for describing the startup of anaerobic systems.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie1001857

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7183–7192

Titre :	Pd − Cu and Pt − Cu catalysts supported on carbon nanotubes for nitrate reduction in water
Type de document :	texte imprimé
Auteurs :	Olivia Salomé G. P. Soares, Auteur ; José J. M. Orfao, Auteur ; Manuel Fernando R. Pereira, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7183–7192
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Catalysts Nanotubes carbon.
Résumé :	The influence of the preparation conditions on the performance of Pd−Cu and Pt−Cu supported on multiwalled carbon nanotubes for the reduction of nitrates was studied and compared with that obtained using a commercial activated carbon as support. Different preparation conditions lead to different catalytic activities and selectivities. Generally, the activity decreases by increasing the calcination and reduction temperatures for the catalysts supported on the original carbon nanotubes, where the nitrate conversion varies from 67% (noncalcined and nonreduced) to 15% (calcined and reduced at 200 °C) for the pair Pd−Cu after 5 h of reaction; the inverse performance was observed for the catalysts supported on carbon nanotubes previously oxidized with HNO3 and on this same sample heat treated at 400 °C. The functional groups created during the oxidation treatment have a negative effect on the catalyst performance. For all the preparation conditions tested, the Pd−Cu pair is more selective to nitrogen than the pair Pt−Cu; 82% and 37% are the highest values obtained for each pair, respectively. Carbon nanotubes are demonstrated to be a good support for this reaction.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie1001907

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp.7176–7182

Titre :	Cadmium compounds as catalysts for biodiesel production
Type de document :	texte imprimé
Auteurs :	Melquizedeque B. Alves, Auteur ; Fernando C. M. Medeiros, Auteur ; Paulo A. Z. Suarez, Auteur
Année de publication :	2010
Article en page(s) :	pp.7176–7182
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Catalysts Biodiesel
Résumé :	Divalent cadmium compounds, particularly CdO, were used as Lewis-acid catalysts in the hydrolysis, esterification, and transesterification of pure triacylglycerides or fatty acids obtained from neutralized soybean oil, as well as mixtures of these substrates. In more than one step, reaction yields of up to 98% in fatty acids or fatty acid methyl esters were achieved. To study the use of these reactions for the development of technologies for biodiesel production from low-grade starting materials, a study was also carried out using a real sample with a high content of free fatty acids from the Brazilian savanna palm-tree oil called Macauba (Acrocomia sclerocarpa M.). Using multistep, sequential, or combined (one-pot) reaction processes, it was possible to obtain an overall reaction yield of up to 98% in methyl esters.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100172u

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7168–7175

Titre :	Enzymatic production of decyl acetate : kinetic study in n - hexane and comparison with supercritical CO2
Type de document :	texte imprimé
Auteurs :	Adriano S. Ribeiro, Auteur ; Manuela V. Oliveira, Auteur ; Sílvia F. Rebocho, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7168–7175
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	kinetics
Résumé :	The kinetics of the lipase-catalyzed synthesis of decyl acetate, by the transesterification reaction of vinyl acetate with decanol, was investigated at 30 °C using n-hexane as the solvent. Novozym 435 was found to be the most active catalyst among the immobilized lipases tested. Given the nonideality of the reaction mixture, only a thermodynamic activity-based kinetics was found to be suitable to represent the experimental data in the entire range of compositions tested (0.1−1.4 M). The reaction follows a ping-pong bi-bi mechanism, in which inhibition only by excess of alcohol was identified. Although intraparticle diffusional limitations were detected, intrinsic kinetic parameters were obtained by crushing the catalyst particles. The results were compared to those obtained with supercritical CO2 as the solvent. For the conditions tested, Candida antarctica lipase B showed higher activity in the organic medium.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie902026d

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7159–7167

Titre :	Biodegradation of 2-chlorobenzoic acid by Klebsiella oxytoca : mathematical modeling and effect of some growth conditions
Type de document :	texte imprimé
Auteurs :	Isam H. Aljundi, Auteur ; Khaled M. Khleifat, Auteur ; Ali M. Khlaifat, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7159–7167
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Biodegradation
Résumé :	Klebsiella oxytoca was grown in batch cultures using a 2-chlorobenzoic acid (2-CBA) containing minimal salt medium. 2-CBA was the sole source for carbon and energy.1H NMR and electron-impact mass spectra results suggested an ortho-cleavage pathway of the 2-CBA degradation. An unstructured model with substrate inhibition was successfully applied to the 2-CBA experimental data at different concentrations. The maximum specific growth rate, saturation constant, and substrate inhibition constant were found to be 0.8573 h−1, 10.441 mM, and 50.95 mM, respectively. All carbon sources exhibited different growth kinetics and caused an increase in bacterial growth several times (2−4 fold). Glucose, sorbitol, and fructose at 0.2% concentration, as additional carbon sources, decreased the initial degradation rates of 2-CBA at ranges of 20−70% lower than that of the control. At the same time, lactose, maltose, and sucrose led to the increase in the 2-CBA biodegradation. Nitrogen sources (except l-prolin) caused an inhibition in 2-CBA degradation by 55, 60, and 33% for yeast extract, casein, and trypton, respectively. The data showed that different initial (inocula) densities affected the induction time for 2-CBA degradation and resulted in the different degradation rates by concentration-dependent manner. 2-CBA degradation was optimally achieved at a 37 °C incubation temperature and a pH of 7.0.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100964f

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7152–7158

Titre :	Seeded emulsion polymerization of butyl acrylate using a redox initiator system : kinetics and mechanism
Type de document :	texte imprimé
Auteurs :	Zhen-guo Liu, Auteur ; Ye Han, Auteur ; Chao Zhou, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7152–7158
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Kinetics Mechanism
Résumé :	Seeded emulsion polymerization of n-butyl acrylate (n-BA) was initiated by a redox initiator system: cumene hydroperoxide/ferrous sulfate hexahydrate/ethylene-diaminetetraacetic acid monosodium salt/sodium formaldehyde sulfoxylate (CHP−Fe2+−EDTA−SFS). Final poly(n-butylacrylate) (PBA) particles with narrow size distribution were obtained. The kinetics and mechanism of seeded emulsion polymerization initiated by the redox initiator system were investigated. Special care was focused on effects of component concentration of the redox initiator system on the seeded emulsion polymerization kinetics. Particle growth and pH variation during the polymerization were also studied. It was found that the polymerization rate and the overall conversion increased with increasing CHP and SFS concentration. Interestingly, the optimal molar ratio of CHP/SFS was 1.10/3.81 rather than being equimolar in our work. In addition, an optimal molar ratio of EDTA to ferrous ions (2.19 × 10−5 mol/7.12 × 10−6 mol) was found. The polymerization rate increased first and then decreased with increases in ferrous ion concentration. The pH value in the system decreased as the polymerization proceeded. A limiting conversion phenomenon of conversion not being able to exceed 20% was found, and an explanation to the limiting conversion was proposed on the basis of the views of the practical cumulative formation constant log KMY and reaction rate comparison. When another activator solution (EDTA/FES/SFS (mol) 2.19 × 10−5/7.12 × 10−6/1.91 × 10−3) was added, the limiting conversion was removed and the final conversion reached 97%.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901359z

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7147–7151

Titre :	Quaternaries as intermediates in the thermal and oxidative degradation of alkanolamines
Type de document :	texte imprimé
Auteurs :	Stephen A. Bedell, Auteur ; Clare M. Worley, Auteur ; Rida Sadek Al-Horr, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7147–7151
Note générale :	Indusrtrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Thermal Oxidative Degradation
Résumé :	Mass spectral evidence is presented for the formation of quaternaries in the high temperature (140 °C) autoxidation of MDEA. Additionally it is demonstrated that the quaternary reacts with neutral amines in a manner consistent with an SN2 mechanism. Rate studies are presented which could be extended to include a systematic variation of nucleophiles, quaternaries, temperature, and solvent composition and allow precise modeling of thermal degradation.
ISSN :	0888-85
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100938e

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7136–7146

Titre :	Interpenetrating Networks of Cross-Linked Poly(acrylic acid) and Cross-linked Polyethyleneimine (80% Ethoxylated) for Desalination of Brackish Water by Thermoreversible Sorption
Type de document :	texte imprimé
Auteurs :	Manas Chanda, Auteur ; S. Arumugom Pillay, Auteur ; Amitava Sarkar, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7136–7146
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Polymer networks
Résumé :	Interpenetrating polymer networks (IPNs) comprising weakly acidic and weakly basic cross-linked polymers, namely, poly(acrylic acid-co-ethyleneglycol dimethacrylate) (XPAA) and 80% ethoxylated polyethyleneimine (EPEI) cross-linked with glutaraldehyde, were prepared by the copolymerization of acrylic acid (AA) and ethyleneglycol dimethacrylate by a free-radical method, in the presence of calculated amounts of EPEI in methanol solution, followed by cross-linking with glutaraldehyde. The resulting IPNs, containing carboxylic acid groups and weakly basic tertiary amine groups in close proximity in the same resin bead, exhibited thermally regenerable desalination properties [e.g., sorption of salt at 30 °C and desorption at higher temperatures (80 °C)], simulating the behavior of the well-known Sirotherm resins. For NaCl and MgCl2, the maximum equilibrium sorption (0.5 mmol/g of dry resin in 0.1 M salt solution) was exhibited by an IPN with a carboxylic-to-amine (C/A) mole ratio in the range of 3−5. The equilibrium sorption at 30 °C for NaCl and MgCl2 on an IPN sorbent with a C/A mole ratio of 4.2 (referred to as Sirosorb) fitted well to both the Langmuir and Freundlich isotherms for single-component sorption and the Butler−Ockrent and Jain−Snoeyink models for bicomponent sorption. Containing both carboxylic and amine groups largely in a free state, Sirosorb exhibited buffer action over a wide range of feed solution pH values (3−8) to give nearly constant sorption of NaCl, although the sorption of MgCl2 increased with increasing pH because of additional sorption by ion exchange at the ionic sites formed by neutralization of the carboxylic acid groups. The sorption rate data showed characteristics of particle diffusion control with a NaCl and MgCl2 diffusivity ratio of 2:1, yielding diffusivity values of (2.5−3.9) × 10−7cm2/s for NaCl and (1.2−1.7) × 10−7cm2/s for MgCl2 in the initial period at 30 °C, with the diffusivity falling abruptly in both cases at higher conversion. Continuous column operation performed with Sirosorb showed that the quantity of potable water with a NaCl content of less than 1500 mg/L that can be produced is about 4 times the weight (dry) of the resin, when the influent brackish water has a NaCl content of 3000 mg/L. The used resin was regenerated with 1 M NaCl solution at 90 °C and used repeatedly with no apparent loss of capacity, as demonstrated in the present work for up to 10 cycles of operation.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100342r

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7129–7135

Titre :	Green recovery of gold through biosorption, biocrystallization, and pyro - crystallization
Type de document :	texte imprimé
Auteurs :	M. Sathishkumar, Auteur ; A. Mahadevan, Auteur ; K. Vijayaraghavan, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7129–7135
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Biosorption Biocrystallization
Résumé :	Gold recovery from dilute solutions has always been a subject of great interest due to ever increasing demand of this precious metal. In the present study, an attempt had been made to recover this noble metal in ionic, nanocrystalline, and metallic form using a combination of biosorption, biocrystallization, and pyro-crystallization techniques with Sargassum biomass as biomaterial. Optimization of process parameters revealed that the biosorption capacity increased with a decrease in pH due to an ion-pairing effect. Kinetic studies showed that the biosorption of Au(III) onto Sargassum biomass was a rapid process with more than 90% removal at the initial 15 min. Nonlinear forms of pseudofirst-order and pseudosecond-order models were used to fit the experimental data. The adsorption capacity (Qmax) from the Langmuir model was found to be 32.94 mg/g at pH 2. Maximum desorption of 97.8% was achieved with 2 N NaOH used as desorption medium. Biocrystallization of ionic gold through bioreduction was observed from 30 min with high productivity at pH 8. The X-ray diffraction analysis (XRD) patterns of the gold nanoparticles revealed their biphasic nature. Recovery of the biosorbed ionic gold in metallic form through pyro-crystallization technique showed the possibility of 91.44% recovery of the metal in pure form as revealed by XRD analysis. The overall results indicate that gold from dilute solutions can be recovered through green processes in ionic, nanocrystalline, or metallic form as desired by the end-consumer using Sargassum biomass as biomaterial.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100104j

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7121–7128

Titre :	Antiferroelectric bent - core liquid crystals for molecular switching applications
Type de document :	texte imprimé
Auteurs :	S. Balamurugan, Auteur ; P. Kannan, Auteur ; M. T. Chuang, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7121–7128
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Antiferroélectriques
Résumé :	A homologous series of unsymmetrical bent-core (BC) liquid crystalline (LC) molecules were synthesized and characterized. Structural effects on mesomorphic and physiochemical properties were investigated in terms of variation in one terminal chain length with respect to constant at another terminal. The synthesis and characterization of new bent-core mesogens were exhibiting antiferroelectric switchable columnar phases. The homologues with short methylene chains (8a and 8b) and longer methylene chain (8d−8g) molecules exhibited switchable B2 mesophase and nonswitchable rectangular columnar B1 phase obtained for phase middle homologue (8c). The spacer effect was observed in forming B2 phase with various lengths of spacers. Spontaneous polarization was measured and maximum of 535 nC/cm−1 observed for longer methylene chain containing compound (8g).
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100019p

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 16 (Août 2010) . - pp. 7113–7120

Titre :	Characterization of electron beam irradiated ethylene methyl acrylate copolymer
Type de document :	texte imprimé
Auteurs :	Nilambar Mongal, Auteur ; Debabrata Chakraborty, Auteur ; Rupa Bhattacharyya, Auteur
Année de publication :	2010
Article en page(s) :	pp. 7113–7120
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Electron Beam
Résumé :	The effect of electron beam dose on the mechanical, thermal, and electrical properties over ethylene methylacrylate (EMA) copolymer was investigated. The copolymer (Elvaloy 1224) was subjected to electron beam radiation at different doses for cross-linking, with the incorporation of the sensitizer trimethylolpropane trimethacrylate (TMPTMA) at various levels. It was observed that the mechanical properties reached an optimum level around 60 kGy radiation dose and 1 phr sensitizer. Beyond that, an increase in irradiation dose or sensitizer level contributed little to modify the properties further. These observations were supported from spectral studies. Improved thermal behavior was observed from the thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) thermograms. The electrical properties were affected very little by irradiation.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901966s

Industrial & engineering chemistry research / Paul, Donald R. . Vol. 49 N° 16

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