Catalogue en ligne Bibliothèque Ecole Nationale Polytechnique d'Alger

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8953–8956

Titre :	Measurement and correlation of solubility of diphenyl carbonate in alkanols
Type de document :	texte imprimé
Auteurs :	Dongwei Wei, Auteur ; Yanhong Pei, Auteur
Année de publication :	2008
Article en page(s) :	p. 8953–8956
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Carbonate Alkanols
Résumé :	In an equilibrium vessel, the solubility of diphenyl carbonate (DPC) in alkanols was measured in the temperature range of 283−338 K, using a method in which an excess amount of solute was equilibrated with the alkanol solution. The liquid concentrations of the investigated DPC in the saturated solution were analyzed by spectrophotometry. The solubility data have been correlated as functions of the temperature. Activity coefficients for DPC have been calculated by means of the Wilson, NRTL, and UNIQUAC equations and, with them, were correlated solubility data that were compared with the experimental data. The best correlation of the solubility data has been obtained by the Wilson equation, by which the average root-mean-square deviation of temperature for the seven systems is 1.72 K.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie801263x

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8947–8952

Titre :	Process parameters and kinetics for the electrochemical generation of cerium(IV) methanesulphonate from cerium(III) methanesulphonate
Type de document :	texte imprimé
Auteurs :	Thasan Raju, Auteur ; C. Ahmed Basha, Auteur
Année de publication :	2008
Article en page(s) :	p. 8947–8952
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Electrochemical Cerium(IV) Methanesulphonate from Cerium(III) Methanesulphonate
Résumé :	To study and optimize the process parameters such as current density, temperature, concentration of cerium(III) methanesulphonate and methanesulphonic acid, and kinetics for the electrochemical generation of cerium(IV) methanesulphonate in aqueous methane sulfonic acid medium. A 97% current efficiency and conversion was achieved at 5 A/dm2 current density in 0.8 M cerium(III) methanesulphonate with 2 M methanesulphonic acid medium at 50 °C temperature.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie701727x

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8940–8946

Titre :	Solubility of ethylene in the presence of hydrogen in process solvents under polymerization conditions
Type de document :	texte imprimé
Auteurs :	G. Sivalingam, Auteur ; V. Natarajan, Auteur ; K. R. Sarma, Auteur ; U. Parasuveera, Auteur
Année de publication :	2008
Article en page(s) :	p. 8940–8946
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Ethylene Hydrogen Solvents Polymerization
Résumé :	The concentration of ethylene in the solvent of slurry polymerization process is important as it determines the extent of reaction, reaction temperature, heat duty, and molecular weight. In the present study, gas liquid behavior of ethylene, in the presence and absence of hydrogen, was studied in two process solvents namely, hexane and Varsol at various process pressures and temperatures. Solubility of ethylene increases with increase in pressure and decreases with increase in temperature in both the solvents. Ethylene solubility decreases with increase in carbon number of solvent at identical conditions. The presence of hydrogen strongly influences the solubility of ethylene in hexane and varsol. The solubility of ethylene in hexane decreases in the presence of hydrogen compared to its binary solubility, while the presence of hydrogen increases the solubility of ethylene in varsol compared to its binary solubility. A heterogeneous thermodynamic model based on the Chao−Seader method was adopted for modeling the solubility of ethylene, in the presence and absence of hydrogen, in hexane and varsol. Chao−Seader method uses the Redlich−Kwong equation of state for vapor phase fugacity, Chao−Seader correlation for pure component/reference state fugacity, Scatchard−Hildebrand model for liquid activity coefficient, and Lee−Kesler method for molar volume, Gibbs free energy departure and enthalpy departure of the mixtures. The model could explain the ethylene solubility closely in both solvents with the presence and absence of hydrogen over the entire range of process conditions studied.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie801236m

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8933–8939

Titre :	Clathrate hydrate formation from cyclopentane-in-water emulsions
Type de document :	texte imprimé
Auteurs :	Masahiro Nakajima, Auteur ; Ryo Ohmura, Auteur ; Yasuhiko H. Mori, Auteur
Année de publication :	2008
Article en page(s) :	p. 8933–8939
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Clathrate Hydrate
Résumé :	This paper reports the experimental examinations of hydrate-forming cyclopentane-in-water emulsions as potential thermal energy storage media for air-conditioning systems. It was demonstrated that an adequately compounded cyclopentane/water/surfactant mixture formed a stable emulsion with the aid of continuous agitation and, through its cooling to ∼2 °C, turned into a bulky mass of granular hydrate crystals. The behavior of the hydrate formation was investigated by varying the amount and composition of the surfactant (or surfactant mixture) in the sample cyclopentane/water/surfactant mixture from run to run in order to determine the appropriate preparation of the mixture for efficient hydrate formation. Also performed were measurements of the effective heat of dissociation for the granular hydrate products obtained in the above hydrate-forming experiments. The measurements showed that the effective heat of dissociation can be as high as ∼93% of the intrinsic heat of dissociation of cyclopentane hydrate crystals, thereby indicating a sufficient potential of the cyclopentane-in-water emulsions as thermal energy storage media.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800949k

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8926–8932

Titre :	Validation study of two continuum granular frictional flow theories
Type de document :	texte imprimé
Auteurs :	Sofiane Benyahia, Auteur
Année de publication :	2008
Article en page(s) :	p. 8926–8932
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	dilute flow
Résumé :	Granular kinetic theories are valid in both kinetic (dilute) flow regime and dense collisional (intermediate) flow regime. This is true as long as contacts between two colliding particles are instantaneous. Empirical theories derived from soil mechanics have been traditionally used in continuum modeling for dense granular flows dominated by enduring contact between particles. This study focuses on validating two continuum theories commonly used to model dense frictional granular flows. The first validation example is conducted for a granular bin discharge, and model predictions are compared with a well-known empirical correlation for the discharge rate. The second example involves a more detailed comparison of flow variables with predictions obtained using a discrete technique for granular flow in a simple shear cell. The frictional flow theory that is only activated at the quasi-static flow regime above maximum packing does not show accurate predictions. Better predictions are obtained using a frictional theory that extends in the intermediate flow regime below packing where both collisional and enduring contact between particles occur.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie8003557

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8918–8925

Titre :	Determination of CO2 minimum miscibility pressure from measured and predicted equilibrium interfacial tensions
Type de document :	texte imprimé
Auteurs :	Morteza Nobakht, Auteur ; Samane Moghadam, Auteur ; Yongan Gu, Auteur
Année de publication :	2008
Article en page(s) :	p. 8918–8925
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	CO2 Minimum
Résumé :	Accurate determination of the minimum miscibility pressure (MMP) of a crude oil−CO2 system at the actual reservoir temperature is required in order to determine whether CO2 flooding is immiscible or miscible under the actual reservoir pressure. The objective of this study is to determine the MMPs of a crude oil−CO2 system from its measured and predicted equilibrium interfacial tension (IFT) versus equilibrium pressure data at a constant temperature. In the experiment, first, the CO2 solubilities in the crude oil are measured under four different equilibrium pressures. Second, the equilibrium IFTs of the crude oil−CO2 system are measured at 12 different equilibrium pressures and a constant temperature of T = 27 °C by applying the axisymmetric drop shape analysis (ADSA) technique for the pendant drop case. The detailed experimental results show that the CO2 solubility in the crude oil is increased almost linearly with the equilibrium pressure. It is also found that the measured crude oil−CO2 equilibrium IFT is reduced almost linearly with the equilibrium pressure as long as it is lower than a threshold pressure. The measured equilibrium IFT versus equilibrium pressure data are used to determine the MMP of the crude oil−CO2 system by applying the so-called vanishing interfacial tension (VIT) technique. In addition, the equilibrium IFT versus equilibrium pressure data of the crude oil−CO2 system are predicted by using the parachor model and linear gradient theory (LGT) model, respectively. The predicted equilibrium IFT data from each model are also used to determine the MMP of the same crude oil−CO2 system. Comparison of the MMPs determined from the two equilibrium IFT prediction models and that determined from the measured equilibrium IFTs shows that the LGT model is suitable for determining the MMP of the crude oil−CO2 system.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800358g

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8911–8917

Titre :	Investigation of Interfacial Tensions for Carbon Dioxide Aqueous Solutions by Perturbed-Chain Statistical Associating Fluid Theory Combined with Density-Gradient Theory
Type de document :	texte imprimé
Auteurs :	Xiao-Sen Li, Auteur ; Jian-Min Liu, Auteur ; Dong Fu, Auteur
Année de publication :	2008
Article en page(s) :	p. 8911–8917
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Carbon Dioxide Aqueous Solutions Perturbed-Chain
Résumé :	The perturbed-chain statistical associating fluid theory and density-gradient theory are used to construct an equation of state (EOS) applicable for the phase behaviors of carbon dioxide aqueous solutions. With the molecular parameters and influence parameters respectively regressed from bulk properties and surface tensions of pure fluids as input, both the bulk and interfacial properties of carbon dioxide aqueous solutions are satisfactorily correlated by adjusting the binary interaction parameter (kij). Our results show that the constructed EOS is able to describe the interfacial properties of carbon dioxide aqueous solutions in a wide temperature range, and illustrate the influences of temperature, pressure, and densities in each phase on the interfacial properties.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800959h

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8906–8910

Titre :	Determination of cellulose reactivity by using phosphitylation and quantitative 31P NMR spectroscopy
Type de document :	texte imprimé
Auteurs :	Ilari Filpponen, Auteur ; Dimitris S. Argyropoulos, Auteur
Année de publication :	2008
Article en page(s) :	p. 8906–8910
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Cellulose Phosphitylation
Résumé :	The phosphitylation of cellulose with 2-chloro-4,4,5,5-tetramethyl-1,3,2-dioxaphospholane [P(II)], is proposed as a means to determine its reactivity via an evaluation of its accessible hydroxyl groups. A variety of cellulose samples were subjected to this phosphitylation reaction, and the consumption of phosphitylation reagent was followed by quantitative 31P NMR spectroscopy. This consumption was found to be directly proportional to the amount of reactive hydroxyl groups on the cellulosic material. To further evaluate the quantitative reliability of this methodology, cellulose samples were subjected to a series of mechanical beating treatments, and the changes in the amount of accessible OH groups were evaluated. In addition, cellulose samples were equilibrated to various moisture contents, and their accessible OH groups were determined using the developed methodology. Both variables examined were found to affect the amount of reactive OH groups present on the samples with variations in the moisture content having a greater effect. For example, up to 6.5 mmol g−1, of accessible OH groups were found to be created within the highly refined samples at the highest moisture content.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800936x

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8894–8905

Titre :	Joule−Thomson inversion curves and third virial coefficients for pure fluids from molecular-based models
Type de document :	texte imprimé
Auteurs :	F. Castro-Marcano, Auteur ; C. G. Olivera-Fuentes, Auteur ; C. M. Colina, Auteur
Année de publication :	2008
Article en page(s) :	p. 8894–8905
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Joule−Thomson Curves
Résumé :	In this work, we present the application of the BACKONE, PC-SAFT, SAFT-VR, and soft-SAFT models to examine the impact of the accuracy of representation of third virial coefficients on the behavior of the correspondingly predicted Joule−Thomson inversion curve (JTIC). Calculations were performed for nonassociating fluids such as ethane and pentane, associating fluids such as alcohols, and quadrupolar fluids such as nitrogen and carbon dioxide. By taking advantage of the molecular nature of the models investigated, we were able to evaluate the separate contributions to the Helmholtz free energy. Nonassociating and quadrupolar fluids are mostly governed by the dispersion contribution, whereas, as expected, the association term plays a predominant role for associating compounds. We validated our previous findings that deviations from the correct shape of the JTIC at high temperatures directly reflect the inadequacies in the predicted third virial coefficients. Consequently, much attention should be dedicated to the reliable description of virial coefficients in building and testing any newly developed equation of state.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800651q

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8888–8893

Titre :	New cuprous adsorbent prepared by a bioreduction method for SO2 removal at low temperature
Type de document :	texte imprimé
Auteurs :	Lishan Jia, Auteur ; Hao Song, Auteur ; Qingbiao Li, Auteur ; Weiping Fang, Auteur
Année de publication :	2008
Article en page(s) :	p. 8888–8893
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Bioreduction Method SO2
Résumé :	A new cuprous adsorbent was prepared by bioreduction method with biomass R08 and its desulfurization ability and regenerative property at low temperature were studied. The results indicated that the amount of SO2 adsorbed on the adsorbent was lower than that on Cu/γ-Al2O3 prepared by chemical method at low temperature; however, it can be easily regenerated and the regenerative adsorbent still has a good SO2 adsorption ability, higher than 87% of that in fresh adsorbent after six regenerations. XPS and FTIR analysis showed that biomass can reduce Cu2+ to Cu+ by aldose and keep the valence of copper exposed to O2 and H2O atmosphere. Furthermore, SO2 is adsorbed on the sorbent with chemical complexation bonds so that it can be desorbed by increasing temperature which is different from γ-Al2O3, Cu(II)/γ-Al2O3 and Cu(I)/γ-Al2O3 that sulfate species are formed.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800059z

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8869–8887

Titre :	Integrating controlled random search into the Line-Up competition algorithm to solve unsteady operation problems
Type de document :	texte imprimé
Auteurs :	Daim-Yuang Sun, Auteur ; Pi-Min Lin, Auteur ; Shu-Ping Lin, Auteur
Année de publication :	2008
Article en page(s) :	p. 8869–8887
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Controlled Random Line-Up Algorithm
Résumé :	In this work, a line-up competition algorithm (LCA) is applied to solve the dynamic optimization problems derived from unsteady chemical systems. The problems are first converted ito nonlinear programming problems using the concept of control vector parametrization. The parameters embedded in the converted problems then are selected by LCA. To improve numerical accuracy, the normal (Gaussian) sampling policy is introduced to replace the uniform sampling policy used in basic LCA. Variable step input (VSI) and variable ramp input (VRI) are respectively considered to rebuild the control policy in solutions. Some typical examples are provided to demonstrate the robustness and efficiency of this modification.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie8009999

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8859–8868

Titre :	Modeling Phase Equilibria of Asymmetric Mixtures Using a Group-Contribution SAFT (GC-SAFT) with a kij Correlation Method Based on Londonʼs Theory. 2. Application to Binary Mixtures Containing Aromatic Hydrocarbons, n-Alkanes, CO2, N2, and H2S
Type de document :	texte imprimé
Auteurs :	Dong Nguyen-Huynh, Auteur ; T. K. S. Tran, Auteur ; S. Tamouza, Auteur ; Jean-Philippe Passarello, Auteur
Année de publication :	2008
Article en page(s) :	p. 8859–8868
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	SAFT (GC-SAFT) kij Correlation Hydrocarbons n-Alkanes CO2 N2 H2S
Résumé :	A group-contribution statistical associating fluid theory equation of state (GC-SAFT EOS) that was proposed by Tamouza et al. [Tamouza et al. Fluid Phase Equilib. 2004, 222−223, 67−76], which was extended in the first part in this series of papers to the asymmetric systems CO2 + n-alkane, methane + n-alkane, and ethane + n-alkane, is further tested here on binary mixtures that contain aromatic hydrocarbons, n-alkanes, CO2, N2, and H2S. The method for correlating the binary interaction parameters (kij), which is inspired by Londonʼs theory of dispersive interactions, uses only pure compound adjustable parameters (“pseudo-ionization energies” of compounds i and j, denoted as Ji and Jj). A group contribution for the latter parameters also is used for n-alkane and alkyl benzene series. Numerous prediction tests on the aforementioned cited systems were performed in a systematic and comprehensive way. Predictions are both qualitatively and quantitatively satisfactory, within deviations (4%−5%) that are comparable to those obtained on previously investigated systems (n-alkane + n-alkane, n-alkane + aromatic, n-alkane + n-alkanol).
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie071644j

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8847–8858

Titre :	Modeling phase equilibria of asymmetric mixtures using a group-contribution SAFT (GC-SAFT) with a kij correlation method based on London’s theory. 1. application to CO2 + n-Alkane, Methane + n-Alkane, and Ethane + n-Alkane systems
Type de document :	texte imprimé
Auteurs :	Dong Nguyen-Huynh, Auteur ; Jean-Philippe Passarello, Auteur ; Pascal Tobaly, Auteur
Année de publication :	2008
Article en page(s) :	p. 8847–8858
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	SAFT (GC-SAFT) kij Correlation CO2 + n-Alkane Methane + n-Alkane Ethane + n-Alkane
Résumé :	Here, a group contribution statistical associating fluid theory equation of state (SAFT EOS) (GC-SAFT) proposed earlier by our group (Tamouza et al., Fluid Phase Equilib. 2004, 222−223, 67−76) is extended to some asymmetric systems, using a method for correlating the kij binary parameters, using only pure compound parameters. The method is inspired by London’s theory of dispersive interactions and correlates the kij values to the “pseudo-ionization energies” of compounds i and j (denoted as Ji and Jj, respectively). A group contribution for the latter parameters is also proposed, in view of obtaining a more-predictive model. Correlation tests of phase equilibria are conducted on some CO2 + n-alkane systems. Using the parameters thus obtained, the phase envelopes of other CO2 + n-alkane systems, as well as methane + n-alkane and ethane + n-alkane systems, were fully predicted. Correlation and predictions are qualitatively and quantitatively satisfactory. The deviations are within 4%−5% (i.e., comparable to those obtained on previously investigated systems).
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie071643r

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8840–8846

Titre :	New HIGEE-rotating zigzag bed and its mass transfer performance
Type de document :	texte imprimé
Auteurs :	Q.G. Wang, Auteur ; O. G. Xu, Auteur ; Z. C. Xu, Auteur ; J. B. Ji, Auteur
Année de publication :	2008
Article en page(s) :	p. 8840–8846
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	HIGEE-Rotating Zigzag Bed
Résumé :	To overcome the disadvantages of the rotating bed available in open literature, a novel kind of high gravity device-rotating zigzag bed (RZB) was developed, which exhibits many superior features owing to its unique rotor combining a rotational part with a stationary one. The outstanding characteristics of RZB are its capability of middle-feed and easily realizing multirotor configuration in one unit by simply installing multiple rotors along the same axis. Thus one unit of RZB can be applied to continuous distillation processes with a higher mass transfer capacity. A preliminary test of mass transfer performance of the RZB in a pilot-scale system using methanol−water was carried out in this study. Experimental results show its excellent mass transfer behavior with an acceptable pressure drop. Comparison with rotating packing bed (RPB) shows that RZB provides equivalent mass transfer efficiency to RPB but exhibits excellent operability with a higher turndown ratio than that of RPB. Comparison with valve tray indicates that the baffle efficiency of RZB is slightly lower than the plate efficiency of valve tray. But if the difference between the tray space and baffle space is taken into consideration, RZB provides much higher efficiency than that of valve tray. Therefore the RZB is a kind of high efficiency gas−liquid contactor and a promising alternative in chemical process industries.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie801020u

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8828–8839

Titre :	Rag layers in oil sand froths
Type de document :	texte imprimé
Auteurs :	Mehrrad Saadatmand, Auteur ; Harvey W. Yarranton, Auteur ; Kevin Moran, Auteur
Année de publication :	2008
Article en page(s) :	p. 8828–8839
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	oil sand
Résumé :	During the settling stages in some oil sands froth treatments, a rag layer (an undesirable mixture of dispersed oil, water, and solids) can form at the water−oil interface. To investigate rag layer formation, oil sand froths were diluted with mixtures of toluene and heptane and the diluted froths were centrifuged in steps of increasing rpm. The volumes of oil phase, rag layer, free water, and sediment were measured after each step. The data obtained from the experiments were used for material balances to determine the composition of the rag layers. The size and properties of the rag layer solids were also measured. Two mechanisms were found to influence rag layer formation: slow coalescence of emulsified water between 1500 and 3000 rpm (200−1000 times gravity); trapping of fine intermediate to oil wet solids at higher rpm and residence times. The main process factors affecting rag formation appear to be the type of diluent and asphaltene precipitation. As well, higher quality oil sand produced much smaller rag layers.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800601r

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8823–8827

Titre :	Improved absorption in gas−liquid systems by the addition of a low surface tension component in the gas and/or liquid phase
Type de document :	texte imprimé
Auteurs :	Nai-Hsuan Yang, Auteur ; Yi-Jen Chen, Auteur ; Chien-Chih Liao, Auteur ; Tsair-Wang Chung, Auteur
Année de publication :	2008
Article en page(s) :	p. 8823–8827
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Gas−Liquid
Résumé :	If a system uses the phenomenon of Marangoni convection, there will be more interfacial turbulence and this may dominate the mass transfer performance between the gas and liquid phases. Marangoni convection was applied in a gas−liquid contact device (dehumidifier) in this study to measure the effect of interfacial turbulence on the water vapor removal efficiency caused by adding a low surface tension component (99.5% ethanol) into the gas or liquid phase at room temperature. The differences in water vapor removal efficiency under different conditions with and without the addition of ethanol into the moist air or working solution (38−42 wt % aqueous lithium chloride solution) were observed. Since the Marangoni effect was more pronounced when the concentration of working solution was greater than a specific value, the trend line for water vapor removal efficiency in different solution concentrations was presented as a broken line in this study. The break in the trend line is the critical concentration of the working solution, and the value is about 40 wt % of aqueous lithium chloride solution. The experimental results show that addition of low surface tension ethanol into the gas phase was better than adding it into the liquid phase for the interfacial mass transfer performance in this gas−liquid contact device.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800316n

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8815–8822

Titre :	Synthesis of multicomponent products separation sequences via stochastic GP method
Type de document :	texte imprimé
Auteurs :	Xiao-Hong Wang, Auteur ; Yu-Gang Li, Auteur
Année de publication :	2008
Article en page(s) :	p. 8815–8822
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Stochastic GP Method
Résumé :	This paper addresses the application of genetic programming (GP) to the synthesis of multicomponent products nonsharp distillation sequences, and the proposed method regards minimizing the annual total cost as an optimization objective and seeks the nonsharp separation optimal flow to give the major technological parameters of the important equipment which provide the accurate theoretical basis for actual production. In combination with the domain knowledge of chemical engineering, some evolutionary factors are improved, and a set of a special encoding method and solving strategy is proposed to deal with this kind of problem. The system structural variable is optimized by GP, and the continuous variable is optimized by the complex algorithm simultaneously. Because GP has the automatic searching function, the optimal solution can be automatically found including distillation, splitting, blending, and bypassing operations without any superstructures of nonsharp distillation sequences. Three illustrating examples are presented to demonstrate the effective computational strategies.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800610s

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8808–8814

Titre :	How Is effective enantioselectivity of immobilized enzyme in kinetic resolution of racemate affected in a fixed-bed reactor?
Type de document :	texte imprimé
Auteurs :	Hongwei Yu, Auteur ; Chi Bun Ching, Auteur
Année de publication :	2008
Article en page(s) :	p. 8808–8814
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Enantioselectivity
Résumé :	The purpose of this theoretical discussion is to help researchers understand how some parameters and reaction type (first-order and Michaelis−Menten kinetic) could impact effective enantioselectivity of enzyme in a fixed-bed reactor, including adsorption equilibrium constant (adsorption effect), Biot number, Peclet number, and bed length parameter. The theoretical analysis clearly derives that reaction rate is able to impact the effective enantioselectivity of enzyme through controlling the loading of enzyme on the solid support. In addition, adsorption phenomenon and reaction type have no effect on the effective enantioselectivity in a fixed-bed reactor. Among these parameters, Bi (<10) shows significant effect on the effective enantioselectivity, which indicates that external mass transfer limitation must be controlled. The interesting analysis suggests that cross-link enzyme aggregates without carrier could be an optional way to overcome mass transfer limitation for immobilized enzyme, and if solid support is applied, adsorption method, which is able to facilitate substrates to contact with enzyme compared to other immobilization methods, could be the best choice to immobilize enzyme when the kinetic resolution of racemate is conducted in a fixed-bed reactor.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800429e

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8801–8807

Titre :	Selective extraction and identification of neutral nitrogen compounds contained in straight-run diesel feed Using chloride based ionic liquid
Type de document :	texte imprimé
Auteurs :	Li-Li Xie, Auteur ; Alain Favre-Reguillon, Auteur ; Stephane Pellet-Rostaing, Auteur ; Xu-Xu Wang, Auteur
Année de publication :	2008
Article en page(s) :	p. 8801–8807
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Chloride Based Ionic Liquid Diesel
Résumé :	Extraction of neutral nitrogen-containing compounds (N-compounds) has been investigated with chloride based ionic liquids (ILs) with varying cation classes (imidazolium, pyridinium). ILs were first discriminated by their mutual solubility of ILs and model fuel. Low solubility of 1-butyl-3-methylimidazolinium chloride (BMImCl) and 1-octylpyridinium chloride (OcPyCl) in the model fuel was observed. The ILs were then evaluated using a synthetic solution with dibenzothiophene and carbazole as model compounds, and a high selectivity for N-compounds was found. BMImCl and OcPyCl were then evaluated using straight-run diesel feed, containing 13 400 ppm S and 105 ppm N. An extraction of up to 50% of the N-compounds was obtained in one step whereas the sulfur concentration reduction was only 5%. Both ILs can be regenerated using small amount of water. Extracted compounds could be then extracted using toluene. The major constituents were identified by GC-MS. Analysis of the extracted compounds emphasized the selectivity of the extraction process. Furthermore, refractory sulfur-containing compounds (S-compounds) and polyaromatics were also identified in the extract.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie701704q

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8796–8800

Titre :	The fixed-bed study of dye removal on chitosan beads at high pH
Type de document :	texte imprimé
Auteurs :	Dan Xu, Auteur ; San Hein, Auteur ; Sunsun Leslie Loo, Auteur ; Kean Wang, Auteur
Année de publication :	2008
Article en page(s) :	p. 8796–8800
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Beads High pH
Résumé :	Chitosan hydrogel beads were modified with ammonium sulfate to remove a dye (Acid Orange-7) in aqueous solutions at pH 8.2. The modified beads present much higher sorption capacity than the native beads in the basic solution. The sorption equilibrium was measured in a batch adsorber, and kinetics was investigated in a fixed bed rig. The breakthrough curves were found to be J-shaped in general and were modeled by the Wheeler−Jonas equation with a two-segmented approach. Analysis shows that the kinetics is controlled by film resistance and intraparticle diffusion in each segment, respectively.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800387z

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8785–8795

Titre :	Costs for rescheduling actions : a critical issue for reducing the gap between scheduling theory and practice
Type de document :	texte imprimé
Auteurs :	Kopanos, Georgios M., Auteur ; Elisabet Capon-Garcia, Auteur ; Antonio Espuna, Auteur ; Puigjaner, Luis, Auteur
Année de publication :	2008
Article en page(s) :	p. 8785–8795
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Scheduling
Résumé :	Rescheduling programmed tasks, when an unexpected event occurs, may affect the smooth operation of the plant if the initial schedule is not taken into account. This work addresses the penalty incurred by rescheduling actions and the optimization procedure to preserve schedule stability. To adjust the rescheduling process to the needs of the decision-maker, rescheduling costs are included to the initial objective function. Namely, unit reallocation and sequencing alterations are the sources of rescheduling costs. A mixed-integer linear programming (MILP) model for the simultaneous rescheduling of multiple operations that permits local reordering, unit reallocation, and accommodation of new orders, is considered. The need to consider rescheduling penalties in the optimization procedure is highlighted through several case studies. As a result, the production plant stability and efficiency are preserved, whereas the generation of pseudo-optimal schedules is avoided. In addition, the tradeoff between the original objective function optimization and the smooth operation of the plant is thoroughly examined.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie8005676

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8775–8784

Titre :	Particle swarm optimization algorithm for a campaign planning problem in process industries
Type de document :	texte imprimé
Auteurs :	Lixin Tang, Auteur ; Ping Yan, Auteur
Année de publication :	2008
Article en page(s) :	p. 8775–8784
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	swarm algorithm
Résumé :	Campaign planning problem (CPP) is to determine the number and length of campaigns for different products over a planning horizon such that the setup and inventory holding costs are minimized. This problem can be found frequently in a multiproduct batch processing plant in the processing industry, such as chemical or pharmaceutical industries. This paper investigates a typical CPP and proposes a hybrid approach of heuristic and particle swarm optimization (PSO) algorithms where the PSO is applied to solve one subproblem with binary variables while the heuristic is applied to the other subproblem with remaining variables by fixing binary variables. As for the evaluation of particles, we take the whole objective function of the primal problem as a fitness function which can be calculated by solving the two subproblems. In implementing the PSO, by designing a “product-to-period” representation for a discrete particle, we redefine the particle position and velocity which are different from the standard PSO. Furthermore, a new strategy is developed to move a particle to the new position. To escape from local minima, a disturbance strategy is also introduced during the iteration process of the PSO. Computational results show that the proposed PSO may find optimal or near optimal solutions for the 180 instances generated randomly within a reasonable computational time.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800383y

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8762–8774

Titre :	Stochastic combinatorial optimization approach to biopharmaceutical portfolio management
Type de document :	texte imprimé
Auteurs :	Edmund D. George, Auteur ; Suzanne S. Farid, Auteur
Année de publication :	2008
Article en page(s) :	p. 8762–8774
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Biopharmaceutical Stochastic
Résumé :	Key strategic decisions in biopharmaceutical portfolio management include drug selection, activity scheduling, and third party involvement. Optimizing strategies is complicated by uncertainty, dependency relationships between decisions, and multiple objectives that may conflict. This paper presents the development of a stochastic combinatorial multiobjective optimization framework designed to address these issues. The framework simulates portfolio management strategies while harnessing Bayesian networks and evolutionary computation concertedly to characterize the probabilistic structure of superior decisions and evolve strategies to multiobjective optimality. This formulation is applied to a case study entailing a portfolio of five therapeutic antibody projects. Optimization was driven by two objectives that conflicted here: maximizing profitability and maximizing the probability of being profitable. Initial analysis of competing strategies along the Pareto optimal front indicated that strategies with clear differences in comprising decisions can compete with similar reward−risk profiles. Hence optimization yielded results that were not intuitive but instead suggested that flexibility between strategies can exist in such large-scale problems. A cluster analysis was used to identify the prevalence of broad and superior building blocks along the Pareto front. In-house development of drugs generally emerged as a preferred constituent of superior strategies which suggested a drive toward minimizing contracting fees, premiums, royalty charges, and losses in sales revenue to third parties; no budgetary constraints were imposed in this case study. It appeared that strategies for scheduling activities had the most overarching impact on performance. Strategies for portfolio structure appeared to have the greatest degree of flexibility relative to other strategic components.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie8003144

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8754–8761

Titre :	Three-Dimensional fluid flow in the processing of fine fibers
Type de document :	texte imprimé
Auteurs :	William P. Klinzing, Auteur ; Ephraim M. Sparrow, Auteur
Année de publication :	2008
Article en page(s) :	p. 8754–8761
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Three-Dimensional fluid fibers
Résumé :	In this paper, a multidimensional numerical simulation has been used to investigate the creation of fine fiber by the melt-blown process. The problem involves highly complex fluid flow and convective heat transfer processes. The fine fiber is created by the use of high-velocity, obliquely impinging air jets whose high shear forces stretch a polymer extrudate in the partially fluid state. High-temperature air is used to maintain the fluidity of the polymeric material as it exits the die. The model which was developed and implemented for the simulation closely reflects the physical situation employed in the actual production of fine fibers. The actual configuration of fine fiber production is a linear array of orifices from which the partially fluid polymer emerges. The array contains inherent symmetries which enable the problem to be tractable. Notwithstanding this, the numerical simulation still required multimillions of control volumes to achieve results of practical relevance. The results of the simulation indicate that, contrary to physical intuition, the shear exerted by the airflow is relatively uniform around the circumference of a given fiber. Although the interfiber spacing is small, it does not promote unfavorable fiber-to-fiber interactions.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800099f

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8741–8753

Titre :	Optimizing control of CSTR/distillation column processes with one material recycle
Type de document :	texte imprimé
Auteurs :	Hiroya Seki, Auteur ; Naka Yuji, Auteur
Année de publication :	2008
Article en page(s) :	p. 8741–8753
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	CSTR/Distillation
Résumé :	Control system design for recycle processes that are composed of a continuous stirred tank reactor (CSTR) and a distillation column is discussed. It is shown that the reflux ratio control, which has been known to serve as a self-optimizing control for the process with the elementary chemistry A → B, can be also applied to processes with more-general types of chemistry that involves side reactions. Using the self-optimizing control as the basis, control systems that seek economically optimal operations are hierarchically constructed for example processes with different types of process chemistry. Particularly, for a process that exhibits tradeoff between product yield and separation cost, a linear model predictive controller design example is given with simulation results.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800183a

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8724–8740

Titre :	Optimal design of mixed refrigerant cycles
Type de document :	texte imprimé
Auteurs :	Frank Del Nogal, Auteur ; Jin-Kuk Kim, Auteur ; Simon Perry, Auteur ; Robin Smith, Auteur
Année de publication :	2008
Article en page(s) :	p. 8724–8740
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	mixed refrigerant design
Résumé :	A new approach for the optimal design of mixed refrigerant cycles is presented. It is based on mathematical programming and offers significant improvements in relation to previous approaches. It includes multistage refrigerant compression, full enforcement of the minimum temperature difference in heat exchangers, simultaneous optimization of variables, consideration of capital costs, and the use of stochastic optimization (genetic algorithm) to overcome local optima. The approach can be applied to either single mixed refrigerant cycles or to systems consisting of two of these in cascade. The effectiveness of the method is illustrated by revisiting previously published liquified natural gas case studies, for which better and feasible solutions are produced, and which prove the importance of considering multistage compression and capital costs during optimization. The application of genetic algorithms in the design of mixed refrigerant cycles permits a greater confidence in the optimality of the results.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800515u

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8713–8723

Titre :	Dealing with irregular data in soft sensors : bayesian method and comparative study
Type de document :	texte imprimé
Auteurs :	Khatibisepehr Shima, Auteur ; Biao Huang, Auteur
Année de publication :	2008
Article en page(s) :	p. 8713–8723
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Irregular Data
Résumé :	The main challenge in developing soft sensors in process industry is the existence of irregularity of data, such as measurement noises, outliers, and missing data. This paper is concerned with a comparative study among various data-driven soft sensor algorithms and the Bayesian methods. The algorithms to be considered for a comparative study in this paper include ordinary least-squares, robust regression, error-in-variable methods, partial least-squares, and the Bayesian inference algorithms. Methods for handling irregular data are reviewed. An iterative Bayesian algorithm for handling measurement noise and outliers is proposed. Performance of the Bayesian methods is compared with other existing methods through simulations, a pilot-scale experiment, and an industrial application.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800386v

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8704–8712

Titre :	Dynamic control of a Column/Side-Reactor process
Type de document :	texte imprimé
Auteurs :	Devrim B. Kaymak, Auteur ; William L. Luyben, Auteur
Année de publication :	2008
Article en page(s) :	p. 8704–8712
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Dynamic Control
Résumé :	If the temperature range suitable for reasonable chemical reaction kinetics does not match the temperature range suitable for vapor−liquid equilibrium, reactive columns are not economically attractive. One way to overcome this temperature mismatch is use a flowsheet that features a distillation column with multiple side reactors. The column operates at a pressure that gives temperatures favorable for separation, while the reactors operate at temperatures (and pressures) favorable for reaction kinetics. This paper discusses the controllability of a column/side-reactor process based on the steady-state design studied by Kaymak and Luyben.(1) The performances of two different control structures are explored. The first uses two temperature controllers, one with direct action and the other with reverse action. The second control structure uses an internal composition analyzer. One of the main conclusions is that the opposite actions of controllers in the two-temperature control structure result in a composition breakthrough that moves the column to a different operating condition. The composition and temperature controllers in the second structure have the same action and provide reasonably effective control.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie701705m

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8693–8703

Titre :	Integrated batch-to-batch control and within-batch online control for batch processes using two-step MPLS-based model structures
Type de document :	texte imprimé
Auteurs :	Junghui Chen, Auteur ; Kuen-Chi Lin, Auteur
Année de publication :	2008
Article en page(s) :	p. 8693–8703
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	MPLS-Based Model
Résumé :	A feedback profile tracking scheme is proposed for batch-to-batch and within-batch control of the end-point quality in batch processes. This new method is based on two-step multiway partial least squares (MPLS) models. The first-step MPLS model, called the quality MPLS, is used to relate the final qualities with the online measurements; the second one, called the measurement MPLS, can relate the online measurements with both the manipulated variables and the prior measured variables. Because the standard MPLS model embeds all process variables into a single input data block, the input variables can be adjusted only on the basis of target qualities at the end point. With the proposed method, the desired online measured variables along the time axis can be computed using the quality MPLS; then the operating input variables can be appropriately adjusted using the measurement MPLS to match the desired online measured variables at each time point and finally get the target qualities at the end-time point. Under these two-step MPLS model structures, the integrated control strategy is sequentially developed by combining batch-to-batch control with within-batch control. Also, the conventional double exponentially weighted moving average control method can be separately and directly applied to each input−output variable in the reduced space of the latent variables. It can gradually reduce the model errors for the model-plant mismatches between batches. The applications are discussed through a typical batch reactor to demonstrate the advantages of the proposed method in comparison with the conventional methods.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie070803w

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8684–8692

Titre :	Synthesis of PID tuning rule using the desired closed-loop response
Type de document :	texte imprimé
Auteurs :	Rames Chandra Panda, Auteur
Année de publication :	2008
Article en page(s) :	p. 8684–8692
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Industrial chemistry
Résumé :	Proportional−integral−derivative (PID) controllers are widely used in industry, because of their simple structure and ease in implementation. A tuning method based on the IMC−PID rule is synthesized for stable single-input−single-output systems. The controller transfer function is expanded, in the vicinity of zero in the complex plane, using a Laurent series, to derive analytical expressions for controller parameters. A tuning parameter is chosen to determine the stability of the response/closed-loop system. PID parameters are obtained for different types of processes, and related robustness issues are also discussed.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800258c

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8676–8683

Titre :	Effects of coagulation conditions on properties of multifilament fibers based on dissolution of cellulose in NaOH/Urea aqueous solution
Type de document :	texte imprimé
Auteurs :	Yuan Mao, Auteur ; Lina Zhang, Auteur ; Jie Cai, Auteur ; Jinping Zhou, Auteur
Année de publication :	2008
Article en page(s) :	p. 8676–8683
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Dissolution--Cellulose NaOH/Urea Aqueous
Résumé :	Effects of coagulation temperature, coagulants, and wet-spinning methods on structure and properties of novel regenerated cellulose (RC) fibers prepared from cellulose in 7.5 wt % NaOH/11 wt % urea aqueous solution on pilot scale spinning machine by one- and two-stage coagulation were investigated by tensile testing, optical microscopy, scanning electron micrograph, and wide-angle X-ray diffraction. The results indicated that H2SO4/Na2SO4 and H2SO4 aqueous solutions are potential coagulants for NaOH/urea system and fibers wet-spun from the two-stage coagulation obviously exhibited the better mechanical properties than those from the one-stage coagulation. The optimal coagulation conditions for two-stage coagulation are 10 wt % H2SO4/15 wt % Na2SO4 for the first coagulation bath and 5 wt % H2SO4 for the second bath or 5 wt % H2SO4/15 wt % Na2SO4 for the first coagulation bath and 10 wt % H2SO4 for the second bath. Moreover, the tensile strength of novel fibers increased with a drop in coagulation temperature. The diffusion rate between the coagulant and solvent plays a major role in determining the mechanical properties of the cellulose fibers. Our spinning process was quite different from that of the viscose process, in which orientation and coagulation proceed more or less simultaneously. The production method of this fiber wet-spun could be suitable in the wide range of coagulation conditions, compared to the viscose one.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800833w

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8667–8675

Titre :	Performance enhancement of poly(lactic acid) and sugar beet pulp composites by improving interfacial adhesion and penetration
Type de document :	texte imprimé
Auteurs :	Feng Chen, Auteur ; LinShu Liu, Auteur ; Peter H. Cooke, Auteur ; Kevin B. Hicks, Auteur
Année de publication :	2008
Article en page(s) :	p. 8667–8675
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Poly(lactic acid)
Résumé :	Sugar beet pulp (SBP), the residue from the sugar extraction process, contains abundant dietary fibers and is mainly used for feedstuff. In this study, poly(lactic acid) (PLA) and SBP composites were prepared using a twin screw extruder. The phase structure, thermal properties, mechanical properties, and water absorption of the composites were studied. The molecular weight change of PLA in the composites was also studied. Polymeric diphenylmethane diisocyanate (pMDI) was used as a coupling agent and resulted in significant increases in mechanical properties and water resistance. The tensile strength of the PLA/SBP (70/30 w/w) composite was only 56.9% that of neat PLA, but it was increased to 80.3% with the addition of 0.5% pMDI and further increased to 93.8% at 2% pMDI. With 50% SBP and 2% pMDI, the tensile strength of the composite was 87.8% of that of neat PLA. The microstructure of the composites indicated that the addition of pMDI greatly improved the wettability of the SBP particles by PLA and increased the penetration of PLA into the porous SBP. Consequently, the failure of the composites in mechanical testing changed from extensive debonding without pMDI to progressive rupture of the SBP particles with pMDI.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800930j

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8652–8666

Titre :	Analysis of steady convective heating for molten materials processing within trapezoidal enclosures
Type de document :	texte imprimé
Auteurs :	Tanmay Basak, Auteur ; S. Roy, Auteur ; E. Natarajan, Auteur
Année de publication :	2008
Article en page(s) :	p. 8652–8666
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Convective Heating
Résumé :	Material processing involving natural convection within a trapezoidal enclosure for uniformly and nonuniformly heated bottom wall, insulated top wall, and isothermal sidewalls with inclination angle φ have been investigated. The penalty finite element method is used to obtain isotherm and streamline profiles for model liquids e.g. molten metal, salt water and olive oil. Parametric study for the wide range of Rayleigh number (Ra), 103 ≤ Ra ≤ 105 and Prandtl number (Pr) for model fluids with various tilt angles φ = 45°, 30°, and 0° have been obtained. Secondary circulations were observed during molten metal processing. Streamlines show that the strength of convection is larger for φ = 45° and flow intensities are also found to be larger for olive oil compared to molten metal and salt water. Heat transfer rates are shown via local and average Nusselt number plots. Local heat transfer rates are found to be relatively more for φ = 0° than those with φ = 45° and φ = 30°. Average Nusselt number plots show higher heat transfer rates for φ = 0° except for the nonuniform heating of the bottom wall with Pr = 0.015 (molten metal). Overall, less heat transfer rates are observed for molten metal processing.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800263c

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8645–8651

Titre :	Characterization and evaluation of catalytic dechlorination activity of Pd/Fe bimetallic nanoparticles
Type de document :	texte imprimé
Auteurs :	Xiangyu Wang, Auteur ; Chao Chen, Auteur ; Huiling Liu, Auteur ; Jun Ma, Auteur
Année de publication :	2008
Article en page(s) :	p. 8645–8651
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Dechlorination Pd/Fe
Résumé :	Two kinds of Pd/Fe nanoparticles (NPs) (k-Pd/Fe NPs and p-Pd/Fe NPs) were prepared by using an aqueous solution of potassium hexachloropalladate and an ethanol solution of palladium acetate as palladization solution, respectively, through the chemical precipitation method, followed by drying in an oven under vacuum, and characterized systematically in terms of morphology (SEM), Pd loading (EDS), surface composition (XRF), specific surface area (BET), particle size (TEM), and crystal structure (XRD). Batch experiments were conducted to evaluate the catalytic dechlorination activity of the prepared Pd/Fe NPs. Evidence observed suggests that the activities of various kinds of particles used for dechlorination of chlorinated methanes including carbon tetrachloride (CT), chloroform (CF), and dichloromethane (DCM) followed the order p-Pd/Fe NPs > Fe NPs > k-Pd/Fe NPs > Micro-Fe (commercial microscale iron powder). This order was found to be dependent on the size, surface area, degree of Pd dispersion, and purity extent of metal particles. These results may provide better understanding of the effects of preparing and drying methods on the catalytic dechlorination activity of Pd/Fe NPs.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie701762d

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8639–8644

Titre :	Detoxification kinetic modeling for nonbiodegradable wastewaters : an ecotoxicity lumping approach
Type de document :	texte imprimé
Auteurs :	A. Santos, Auteur ; P. Yustos, Auteur ; S. Rodríguez, Auteur ; F. Vicente, Auteur
Année de publication :	2008
Article en page(s) :	p. 8639–8644
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Detoxification Nonbiodegradable Ecotoxicity
Résumé :	A lumped pseudokinetic model that is able to predict the toxicity change during the treatment of industrial wastewater as a function of the initial toxicity and temperature of the process is proposed. The original pollutant (or pollutant mixture), P, reacts to form a lumped intermediate species, I, which, in turn, reacts to form a nontoxic lumped species D. Therefore, only P and I in this serial scheme, P → I → D, are considered to contribute to the toxicity of the aqueous sample. The median effective nominal concentration of species I, EC50(I), is a fitting parameter in this lumping approach and gives an idea of the toxicity of the first organic intermediates generated, lumped as I. The model was successfully validated by analyzing the toxicity data obtained during the catalytic wet oxidation of phenolic solutions (with phenol, o-cresol, and p-cresol employed as pollutants) in a three-phase fixed-bed reactor. Moreover, the lumped kinetic model developed in a previous work for the mineralization of phenol was also validated by analyzing the total organic carbon (TOC) evolution data obtained with o-cresol and p-cresol as pollutants.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie8010758

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8631–8638

Titre :	Esterification of long-chain acids and alcohols catalyzed by ferric chloride hexahydrate
Type de document :	texte imprimé
Auteurs :	Noboru Ieda, Auteur ; Kshudiram Mantri, Auteur ; Yasuyuki Miyata, Auteur ; Akiyoshi Ozaki, Auteur
Année de publication :	2008
Article en page(s) :	p. 8631–8638
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Acids Alcohols Catalyzed Hexahydrate
Résumé :	A variety of multivalent metal salt, many of them are hydrates, were screened as catalysts for the esterification of fatty acids and alcohols. These salts included chlorides, nitrates, sulfates, and acetates of Fe3+, Al3+, Ga3+, In3+, ZrO2+, HfO2+, Zn2+, Co2+, Ni2+, Mn3+, Cr3+, and Cu2+. Ferric salts, particularly, FeCl3·6H2O, were the most active among the salts screened. The esters of primary C10−C18 fatty acids and alcohols were obtained quantitatively from equimolar mixtures in the presence of FeCl3·6H2O (substrate/catalyst (S/C; mol/mol) = 200, reaction period = 6 h, in refluxing mesitylene). Esters of isostearic acid and C10–C18 fatty alcohols were obtained with large quantities and prolonged reaction periods. The esters of aromatic carboxylic acids with cetyl alcohol and bulky steroid alcohols, including cholesterol, with C8−C18 fatty acids, were obtained in high yield. The cationic cluster formed by hydrolysis of the ferric cation is proposed to be the catalytically active species. Such a catalysis is proposed to occur through the activation of the carboxylic acid by ligand exchange from water to the carboxylate moiety, followed by addition of the alcohol.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800957b

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8625–8630

Titre :	Development of a micropyrolyzer for enhanced Isotope ratio measurement
Type de document :	texte imprimé
Auteurs :	Jianli Hu, Auteur ; Robert A. Dagle, Auteur ; Bradley R. Johnson, Auteur ; Helen W. Kreuzer, Auteur
Année de publication :	2008
Article en page(s) :	p. 8625–8630
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Micropyrolyzer
Résumé :	This paper presents design, fabrication, and testing of a microscale ceramic reactor for the pyrolysis of organic compounds. One application for this pyrolysis reactor is to convert the oxygen and hydrogen atoms in organic compounds to CO and H2 for isotope ratio measurements in a continuous flow mode. Existing commercial pyrolyzers use high carrier gas flow rates (typically 80−100 mL/min) such that >95% of the CO and H2 produced from a given sample is vented before introduction into the mass spectrometer. We describe here the fabrication and testing of a microscale pyrolysis reactor designed to be compatible with existing isotope ratio mass spectrometers. The microreactor uses carrier gas flow rates of 3−5 mL/min, decreasing the proportion of the CO and H2 lost in venting and permitting analysis of samples 20−50 times smaller than can be analyzed with conventional pyrolysis reactors. Results have shown that organic compounds, such as 1-butanol, ethanol, and ethanolamine, can be fully decomposed to desired products CO and H2, at a temperature of 1200 °C, which is 200 °C lower than conventionally reported. Furthermore, we are able to eliminate undesired products such as methane and CO2 in the pyrolysis process. The proof-of-concept experimental results clearly demonstrate that the micropyrolyzer quantitatively converts organic compounds to gases suitable for isotope ratio analysis.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie8009236

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8619–8624

Titre :	Ball mill-assisted dechlorination of flexible and rigid poly(vinyl chloride) in NaOH/EG solution
Type de document :	texte imprimé
Auteurs :	Tomohito Kameda, Auteur ; Masahiko Ono, Auteur ; Guido Grause, Auteur ; Tadaaki Mizoguchi, Auteur
Année de publication :	2008
Article en page(s) :	p. 8619–8624
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Dechlorination vinyl chloride NaOH/EG
Résumé :	Both flexible and rigid forms of poly(vinyl chloride) (PVC) were effectively dechlorinated in NaOH/ethylene glycol (EG) solution during ball mill pulverization. The high degree of dechlorination obtained was attributed to the increased surface area of the crushed PVC particles and the resulting enhancement of contact between the PVC and dissolved hydroxide ions. The common additives diisononyl phthalate and CaCO3 were easily separated from the PVC bulk during the dechlorination reaction. The reaction proceeded under chemical control, with degrees of dechlorination for both flexible and rigid PVC increasing with temperature with apparent activation energies of 110 and 80 kJ/mol, respectively. This reaction was accurately represented by a modified shrinking-core model.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie8006819

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8612–8618

Titre :	Textural and structural analyses of industrial raney nickel catalyst
Type de document :	texte imprimé
Auteurs :	Cristiane B. Rodella, Auteur ; Guinther Kellermann, Auteur ; Maria Suzana P. Francisco, Auteur ; Maura H. Jordao, Auteur
Année de publication :	2008
Article en page(s) :	p. 8612–8618
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Nickel Catalyst
Résumé :	In this work, the influence of the temperature (60, 80, and 110 °C) in the production of Raney Ni catalysts was addressed. The catalysts were obtained by alkaline leaching of a Ni−Al alloy, and both the Ni−Al alloy and the leaching process that was evaluated were provided by an industrial partner. The physical−chemical properties of the catalysts were investigated by X-ray diffraction (XRD), scanning and transmission electron microscopies (FEG-SEM and TEM), X-ray photoelectron spectroscopy (XPS), N2 adsorption, and small-angle X-ray scattering (SAXS) techniques. In particular, a comparison between SAXS and N2 adsorption results about the textural properties is discussed. The three Raney Ni catalysts presented the typical highly porous metallic nickel structure. The analysis of the surface, however, suggested the presence of major contributions of NiO, Ni(OH)2/Ni2O3, and Ni−O−Al species in all samples and the presence of Ni0 for the samples produced at 60 and 80 °C. The two samples prepared at lower temperatures presented similar characteristics: crystalline domains of 50 and 60 Å, BET specific surface area of 58 and 65 m2 g−1, and porosity of 0.100 and 0.107 cm3 g−1, respectively. These properties appear to be more interesting for catalytic purposes than the characteristics of the catalyst prepared at 110 °C: mean crystalline size of 100 Å, BET specific surface area of 51 m2 g−1, and pore volume of the 0.097 cm3 g−1. A higher concentration of Al species, about 80 atom %, however, was also observed on the surface of the catalysts produced at 60 and 80 °C. The larger pores found in the catalyst produced at 110 °C may have facilitated the removal of the Al species during the washing process and are probably related to the larger Ni crystalline domains in this sample.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800543t

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8602–8611

Titre :	Simultaneous ammonia and toluene decomposition on tungsten-based catalysts for hot gas cleanup
Type de document :	texte imprimé
Auteurs :	Sourabh S. Pansare, Auteur ; James G. Goodwin, Auteur ; Santosh Gangwal, Auteur
Année de publication :	2008
Article en page(s) :	p. 8602–8611
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Ammonia Toluene Catalysts Gas cleanup
Résumé :	The current paper reports the results of a study of the simultaneous decomposition of NH3 and toluene on sulfur tolerant nonconventional tungsten-based catalysts [tungsten carbide (WC) and tungstated zirconia (WZ)] at temperatures <750 °C in the presence of H2, CO, CO2, and H2O, such as it would be present in hot gas cleanup following biomass gasification. Toluene was chosen as a model compound to represent tars. The effects of addition of each gasification gas component on the activities of WC and WZ for NH3 and toluene decomposition were investigated. The NH3 and toluene decomposition reactions were conducted at typical hot gas cleanup conditions of 700 °C and 1 atm. In the absence of gasification gases, low activities were observed for toluene decomposition on WC and WZ while complete conversion of 4000 ppm of NH3 was observed at space velocities of 5 800 000 and 385 000 h−1 for WC and WZ, respectively. The presence of H2, CO, CO2, and H2O had a somewhat negative impact on the high activities of WC and WZ for NH3 decomposition while it had a positive impact on the toluene decomposition activities of both the catalysts. However, both WC and WZ were active for the simultaneous removal of NH3 and toluene in the presence of H2, CO, CO2, and H2O. In the presence of gasification gases, both WC and WZ showed comparable performances for toluene decomposition on a “per-g-catalyst” basis with that of a commercial ultrastable Y zeolite (USY). However, on a “per-m2-catalyst” basis, WC showed by far the highest activity.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800525c

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8594–8601

Titre :	Simple procedure for interpreting hydrotreating kinetic data
Type de document :	texte imprimé
Auteurs :	K. T. Kam Ezra, Auteur ; Hamza Al-Bazzaz, Auteur ; Jamal Al-Fadhli, Auteur
Année de publication :	2008
Article en page(s) :	p. 8594–8601
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Hydrotreating
Résumé :	A simple procedure is developed to determine the apparent rate constants, reaction orders, and activation energies of various hydrotreating reactions, such as the hydrodesulfurization (HDS), hydrodemetalation (HDM), hydrodenitrogenation (HDN), and asphaltene cracking (HDAsph) of hydrotreating catalysts loaded in multiple-reactor fixed bed units. The procedure is derived from the basic kinetic and engineering principles. The only required input parameters are the sulfur, vanadium, nickel, nitrogen, and asphaltenes contents in the feedstock and products, reaction temperatures, and liquid hourly space velocity (LHSV). These parameters are normally available from laboratories performing the kinetic studies. Since there is no correlation coefficient in the developed kinetic expression, the apparent reaction rate constant and activation energy for various hydrotreating reactions can be determined directly once the optimum value of the reaction order has been identified. To demonstrate how the procedure works, it has been applied to calculate the kinetic values published in the open literature. Excellent agreements are obtained. The procedure is further verified with kinetic parameters from experiments undertaken in our pilot plants. In some cases, kinetic values which were unable to be determined in our pervious studies can now be obtained. The overall absolute average deviation (AAD) is less than 10%.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie8002705

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8588–8593

Titre :	Combination of V2O5/WO3 - TiO2, Fe - ZSM5, and Cu - ZSM5 Catalysts for the selective catalytic reduction of nitric oxide with ammonia
Type de document :	texte imprimé
Auteurs :	Oliver Krocher, Auteur ; Martin Elsener, Auteur
Année de publication :	2008
Article en page(s) :	p. 8588–8593
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	V2O5/WO3−TiO2,Fe−ZSM5,Cu−ZSM5
Résumé :	Cordierite monoliths coated with V2O5/WO3−TiO2, Fe−ZSM5, and Cu−ZSM5 catalysts were combined to investigate the possibility of combining the advantages of the different single catalysts for the selective catalytic reduction of nitric oxide with ammonia (NO SCR) while minimizing their drawbacks. Selected combinations of two of the three above-mentioned catalysts were connected in series such that the volume of each catalyst was halved in order to maintain the total space velocity constant. The combinations V2O5/WO3−TiO2 followed by Fe−ZSM5 and the reversed catalyst order achieved markedly lower NOx reduction efficiencies (DeNOx) than the pure vanadia-based catalyst. Fe−ZSM5 applied downstream of V2O5/WO3−TiO2 did not reduce the N2O formed over the V-based catalyst at temperatures above 450 °C, as expected from the known N2O decomposition and N2O SCR activities of Fe−ZSM5. When V2O5/WO3−TiO2 was mounted downstream of Fe−ZSM5, ammonia slip was observed even at small NOx reduction efficiencies. The combination of Fe−ZSM5 and Cu−ZSM5 showed high activities at temperatures from 200 to 700 °C with small N2O formation, similar to pure Fe−ZSM5. V2O5/WO3−TiO2 combined with Cu−ZSM5 showed slightly higher activity at lower temperatures than V2O5/WO3−TiO2 only. At temperatures above 350 °C potential ammonia excess was selectively oxidized to nitrogen; in other words, Cu−ZSM5 functions as a selective catalyst for ammonia oxidation.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800951a

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8582–8587

Titre :	Study on the FCC process of a novel riser−downer coupling reactor (III) : industrial trial and CFD modeling
Type de document :	texte imprimé
Auteurs :	Fei Liu, Auteur ; Wei Fei, Auteur ; Guoliang Li, Auteur
Année de publication :	2008
Article en page(s) :	p. 8582–8587
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Industrial Trial CFD Modeling
Résumé :	Industrial trials detailed in a riser−downer coupling reactor proposed for the fluid catalytic cracking (FCC) process are presented in this paper. The trials are based on the fundamental research of hydrodynamics, mixing behaviors, and laboratory-scale hot experiments described in our previous investigations. Compared with the riser reactor with the same feeds and catalyst, the LPG and propylene yield increased by 8.15 and 4.30 wt %, respectively. The gasoline octane number likewise reached 94.8 with 28 wt % olefin content. However, dry gas is significantly suppressed, and the coke has little change in yield even with the increased catalyst to oil ratio. With some gasoline recycling, the LPG and propylene yield increased by 11.45 and 5.06 wt %, respectively, and the olefin content in gasoline significantly decreased to 22 wt %; the high octane number (95.4) is maintained. The computational fluid dynamics (CFD) coupled with a 6-lump kinetic model is also applied to simulate the FCC process for the industrial trials. The yield of propylene and butylene and the temperature profile along the axis direction demonstrated consistency between the simulation results and the experimental data.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800645y

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8572–8581

Titre :	Multiscale modeling and solution multiplicity in catalytic pellet reactors
Type de document :	texte imprimé
Auteurs :	Kedar Kulkarni, Auteur ; Jeonghwa Moon, Auteur ; Libin Zhang, Auteur
Année de publication :	2008
Article en page(s) :	p. 8572–8581
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Pellet Reactors
Résumé :	Transport and reaction phenomena in catalytic pellet reactors are often difficult to analyze because of coupling between heat and mass transport occurring at different space and time scales. To calculate the reactor concentrations and temperatures, it is necessary to account for the species reaction and transport occurring in the reactor bulk at the macroscopic level as well as the catalyst pellets at the microscopic level. The resulting approach yields a large system of nonlinear partial differential equations with multiple scales and solutions that are difficult to find numerically. In addition, the catalyst pellets may operate in multiple steady states for identical conditions. Conventional computational methods may entirely miss the multiplicity phenomenon at the catalyst pellet level and, as a result, may not correctly predict overall reactor yields. In this paper, we introduce two numerical techniques to address multiple scales and multiplicity in heterogeneous reaction models. The first method expands existing bisection with “shooting”; the second global method deploys orthogonal collocation over finite elements with niche evolutionary algorithms. We also propose a new multiscale method entitled effectiveness factor maps to expedite and simplify the numerical effort to solve transport and reaction phenomena at different length scales.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie8003978

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8566–8571

Titre :	Spectroscopic characterization of linseed oil based polymers
Type de document :	texte imprimé
Auteurs :	Vinay Sharma, Auteur ; J. S. Banait, Auteur ; P. P. Kundu, Auteur
Année de publication :	2008
Article en page(s) :	p. 8566–8571
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Linseed Oil Based Polymers
Résumé :	Linseed oil based polymers from cationic and thermal polymerizations have been investigated quantitatively through 1H NMR and FTIR spectroscopic analysis. The solubility of the samples ranges from 22 to 37% for cationic samples and from 4.23 to 53% for thermal samples. The content of the grafted linseed oil calculated from 1H NMR results ranges from 22.9 to 43.0% and from 0 to 10% for cationic and thermal samples. The grafted linseed oil contents from FTIR are 18.2−45.4% and 0−10.7% for cationic and thermal samples. The values obtained through quantitative 1H NMR and FTIR spectroscopic analysis methods are consistent and can be applied to other polymers also.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800415z

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8561–8565

Titre :	Synthesis of environmentally friendly calcium oleate detergent
Type de document :	texte imprimé
Auteurs :	Yonglei Wang, Auteur ; Wumanjiang Eli, Auteur ; Yuanfeng Liu, Auteur
Année de publication :	2008
Article en page(s) :	p. 8561–8565
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	calcium oleate Ca(OH)2 detergent
Résumé :	This article discusses a method for synthesizing an environmentally friendly calcium oleate detergent using vegetable oil instead of mineral oil as the raw material. Reaction conditions including the molar ratio of total lime [Ca(OH)2 and CaO] to oleic acid, the molar ratio of Ca(OH)2 to CaO, the carbonation temperature, the amount of methanol, the molar ratio of water to CaO, the gas flow rate of CO2, and the molar ratio of injected CO2 to total lime [Ca(OH)2 and CaO] were optimized. Using the optimized conditions, a high-alkali calcium oleate solution with a total base number (TBN) of 376 mg of KOH/g and an overbased calcium oleate solution with a value of TBN = 420 mg of KOH/g could be obtained.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800679a

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8555–8560

Titre :	Mathematical model for predicting gel Point in the process of manufacturing alkyd resins
Type de document :	texte imprimé
Auteurs :	M. A. B. Prashantha, Auteur ; J. K. Premachandra, Auteur ; A. D. U. S. Amarasinghe, Auteur
Année de publication :	2008
Article en page(s) :	p. 8555–8560
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Mathematical Manufacturing Alkyd
Résumé :	A mathematical model for the prediction of gel formation in the synthesis of alkyd resins is developed. The probability of developing linear polymer molecules is related to the average functionality, Fav. A statistical factor φ is introduced to represent the probability of having free OH groups in the backbone of a linear alkyd molecule. Factor φ increases from 0 to a maximum of φmax when the acid value decreases from AVinitial to AVmax during the polymerization. Branch generation in alkyd molecules becomes significant only after the acid value is reached, AVmax, and it continues until a gel is formed. At φmax, the average functionality (Fav(max)) and the acid value (AVmax) are calculated in terms of the number of moles of OH groups, number of moles of COOH groups, and total number of molecules per unit mass at the beginning of polymerization. The acid value at the gel point, AVgel, is then calculated using the values of Fav(max) and AVmax. The predicted acid values using the new model are in good agreement with the actual data reported for polyesterification in the synthesis of alkyd resins.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie8005534

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8550–8554

Titre :	Reduction of nitrite by ultrasound-dispersed nanoscale zero-valent iron particles
Type de document :	texte imprimé
Auteurs :	Feng Liang, Auteur ; Jing Fan, Auteur ; Yanhui Guo, Auteur
Année de publication :	2008
Article en page(s) :	p. 8550–8554
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Nitrite Ultrasound Iron
Résumé :	This research focuses on the removal of nitrite by ultrasound-dispersed nanoscale zerovalent iron (NZVI) particles. The factors affecting the removal of nitrite, namely, the length of ultrasonication time, the dosage of NZVI, the initial nitrite concentration, the temperature, and the solution pH, were investigated. Kinetics studies revealed that the denitrification process is a pseudo-first-order reaction with respect to the concentration of nitrite under the given experimental conditions. The derived activation energy of NZVI-based nitrite reduction is 31.44 kJ·mol−1.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie8003946

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8542–8549

Titre :	Influence of lignin structural features on eucalyptus globulus kraft pulping
Type de document :	texte imprimé
Auteurs :	Anderson Guerra, Auteur ; Juan Pedro Elissetche, Auteur
Année de publication :	2008
Article en page(s) :	p. 8542–8549
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Eucalyptus Kraft Pulping
Résumé :	Clones of Eucalyptus globulus Labill. (5- to 7-year-old), from a common geographic area, were evaluated for chemical pulping easiness. Significant variations were observed in the pulp yield and specific wood consumption to produce pulps with similar kappa numbers, as well as in the strength properties of the resulting kraft pulps. Comprehensive lignin analyses were undertaken in an attempt to rationalize the observed differences in these clones’ pulping performance. While lignin content did not correlate with pulp yield, the data reported here provides evidence of the influence of lignin features on the pulping response of different eucalyptus clones. Significant correlations were observed between pulp yield and specific wood consumption and the content of syringyl-type arylglycerol-β-aryl structures (β-O-4 linkages). Furthermore, eucalyptus woods with a greater content of uncondensed β-O-4 linkages were found to require more PFI revolutions to obtain pulps with a given drainability. In contrast, no relationship between pulping efficiency and the other lignin structural features evaluated was apparent, including syringyl/guaiacyl ratio (S/G), total aliphatic and phenolic hydroxyl groups, syringyl and guaiacyl units bearing free phenolic hydroxyls, and the erythro-to-threo ratio of β-O-4 structures. These findings support the use of the content of syringyl-type arylglycerol-β-aryl structures as a selection parameter in clonal breeding programs for pulpwood production.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800320d

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8533–8541

Titre :	Initial degradation rate of p-Nitrophenol in aqueous solution by fenton reaction
Type de document :	texte imprimé
Auteurs :	Meng-Wen Chang, Auteur ; Tai-Shang Chen, Auteur ; Jia-Ming Chern, Auteur
Année de publication :	2008
Article en page(s) :	p. 8533–8541
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	p-Nitrophenol
Résumé :	Because of environmental concern, wastewater containing nitrophenols must be treated before it is allowed to discharge. In addition to traditional treatment methods, advanced oxidation processes (AOPs) using a powerful hydroxyl radical to decompose organic pollutants in wastewater receive great attraction. Among the many AOPs to degrade nitrophenols, the Fenton reaction was proven to be the most effective and the least expensive method, and the resultant solutions treated by the Fenton reagent were not toxic. However, owing to the complicated mechanism involved in the Fenton reaction, an oversimplified first-order rate equation or empirical rate laws were usually used to model the Fenton reaction. Such oversimplified or empirical kinetics cannot be used confidently in the design and operation of large-scale Fenton processes. A series of experiments were carried out to determine the initial decomposition rates of p-nitrophenol (PNP) at varying initial ferrous ion, hydrogen peroxide, and PNP concentrations. The PNP decomposition rate equations for two proposed mechanisms were derived by the general rate methodology. The rate equation resulting from the reaction mechanism involving the PNP reaction with both hydroxyl and hydroperoxy radicals fits the experimental data well.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie8003013

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p. 8526–8532

Titre :	Electrosynthesis of Potassium Permanganate in a Cation Exchange Membrane Cell
Type de document :	texte imprimé
Auteurs :	K. Subramanian, Auteur ; K. G. Gomathi, Auteur ; K. Asokan, Auteur
Année de publication :	2008
Article en page(s) :	p. 8526–8532
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Potassium Permanganate Electrosynthesis
Résumé :	Potassium permanganate is produced by the electro-oxidation of alkaline potassium manganate in a divided electrolytic cell. A filter press type flow electrolyzer has been designed, fabricated, and operated with perfluoro sulfonic acid based cation exchange membrane Nafion 417, precious metal/precious metal oxide coated titanium anode, and stainless steel cathode. Optimum process parameters are evaluated and reported. Performance characteristics of coated titanium anodes are compared with conventional nickel anodes, to fix the most suitable one for the job on hand. Anode materials have been electrochemically characterized by potentiodynamic studies in alkaline potassium manganate solution. Transport properties of the membrane Nafion 417 for K+ ions and water molecules are studied using a small membrane cell operating on batch mode. It has been estimated that each K+ ion transported across the membrane carries with it 1.5 to 1.7 water molecules. The anolyte contains K2MnO4 and KOH. Studies reveal that the relative current efficiency value for electro-oxidation of manganate and the competing anodic oxygen evolution may have a direct bearing on the source of K+ ion transported across the cation exchange membrane.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800240m

[article]
in Industrial & engineering chemistry research > Vol. 47 n°22 (Novembre 2008) . - p.8517–8525

Titre :	Toward a sustainable chemical industry : cyclic innovation applied to ionic liquid-based technology
Type de document :	texte imprimé
Auteurs :	Maaike C. Kroon, Auteur ; Dap Hartmann, Auteur
Année de publication :	2008
Article en page(s) :	p.8517–8525
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Chemical Industry
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie800370t

Industrial & engineering chemistry research / Paul, Donald R. . Vol. 47 n°22

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