Catalogue en ligne Bibliothèque Ecole Nationale Polytechnique d'Alger

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1991–1994

Titre :	Pretreatments of coils to minimize Coke formation in ethylene furnaces
Type de document :	texte imprimé
Auteurs :	Zhang, Zhaobin, Auteur ; Albright, Lyle F., Auteur
Année de publication :	2010
Article en page(s) :	pp 1991–1994
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Pretreatments coils Coke Ethylene furnaces.
Résumé :	Numerous techniques have been considered on how to reduce coke formation and/or coke collection on the inner surfaces of the coils in furnaces producing ethylene, propylene, etc. Such reduction would lead to several beneficial events including much reduced production costs. The techniques tested by Nova Chemical in several of their furnaces have resulted in a major reduction of coke. They have tested several pretreatments of the coils in their furnaces using several oxidizing gases at 800−1200 °C. For example, hydrogen/steam mixtures have been employed. Various pretreatments have been employed in the current study that suggest improved pretreatments are now possible.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900271q

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1986–1990

Titre :	Drying model for calcium alginate beads
Type de document :	texte imprimé
Auteurs :	Lyn, Margaret E., Auteur ; Ying, DanYang, Auteur
Année de publication :	2010
Article en page(s) :	pp 1986–1990
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Calcium alginate beads.
Résumé :	The dehydration of calcium alginate beads is observed to have a simple power-law time dependence. The ratio of the water content, M(t), to the initial water content, M0, can be expressed as The parameter tc is insensitive to the guluronic content of the alginate or the degree of cross-linking. Using this simple model, tc can be estimated from the properties of water vapor, the initial water content, and the relative humidity, in addition to an empirically derived correction factor, K, which has been found to be 2.8 ± 0.3.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901451m

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1982–1985

Titre :	Regeneration of coked al-promoted sulfated zirconia catalysts by high pressure hydrogen
Type de document :	texte imprimé
Auteurs :	Yang, Ying-Chieh, Auteur ; Weng, Hung-Shan, Auteur
Année de publication :	2010
Article en page(s) :	pp 1982–1985
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Catalysts High Pressure Hydrogen.
Résumé :	To avoid the inconvenience and danger caused by using air or oxygen as a regenerating gas for coked catalysts, this work proposes an effective regeneration method for the fouled Al-promoted sulfated zirconia (AL/SZ) catalyst. This work tries hydrogen for regenerating fouled catalysts; nevertheless, regaining activity is low when introducing atmospheric hydrogen as a regenerating gas. Fortunately, over 98% of original activity can be regained using high pressure hydrogen (2.1 MPa) at 250 °C within 8 h. The operation temperature for this new regeneration method is much lower than that for conventional methods using air or oxygen as a regenerating gas. This method does not affect the product distribution of n-C4 isomerization.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900338b

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1975–1981

Titre :	Adapting process unit relations in experimental data weighting procedures : a phase equilibrium case study
Type de document :	texte imprimé
Auteurs :	Ngigi, Geoffrey K., Auteur ; Diane Hildebrandt, Auteur ; David Glasser, Auteur
Année de publication :	2010
Article en page(s) :	pp 1975–1981
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Weighting method Phase equilibrium.
Résumé :	A data weighting method derived from analysis of the distillation column design relation(s) is used on several experimental vapor−liquid equilibrium (VLE) sets of data for estimating the interaction pair parameters of two local-composition models (NRTL and Wilson). It is shown that process equations can provide insights on the requisite objective function(s) to obtain parameters more suited to a particular design intent.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie801987j

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1964–1974

Titre :	Controlled supersaturation precipitation of hydromagnesite for the MgCl2−Na2CO3 system at elevated temperatures : chemical modeling and experiment
Type de document :	texte imprimé
Auteurs :	Cheng, Wenting, Auteur ; Zhibao Li, Auteur
Année de publication :	2010
Article en page(s) :	pp 1964–1974
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Hydromagnesite MgCl2−Na2CO3 System Chemical Modeling.
Résumé :	A new chemical model of supersaturation (S) was developed and applied to test for the precipitation of hydromagnesite [Mg5(CO3)4(OH)2·4H2O] in the MgCl2−Na2CO3 system in supersaturated solutions over the temperature range of 50−90 °C. Based on the new model with the help of the OLI platform, the contour supersaturation of Mg5(CO3)4(OH)2·4H2O has been exactly constructed by calculating the activity coefficients of species in unstable solutions. Mg5(CO3)4(OH)2·4H2O crystals were identified using X-ray diffraction (XRD) analysis and scanning electron microscopy (SEM) images. It was found that the crystal properties, such as morphology, particle size distribution, filtration, and sedimentation characteristics, can be optimized by controlling the supersaturation during precipitation. With the control of supersaturation, well-developed spherical-like Mg5(CO3)4(OH)2·4H2O crystals can grow to an average size of 30−40 μm, indicating a narrow particle size distribution, good filtration characteristics, and a high sedimentation rate. In addition, the Mg5(CO3)4(OH)2·4H2O obtained was calcined to produce high-purity MgO at 800 °C. The size and morphology of MgO were similar to the same characteristics of the corresponding precursors.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9015073

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1958–1963

Titre :	Folate-receptor-targeted delivery of doxorubicin using polyethylene glycol-functionalized gold nanoparticles
Type de document :	texte imprimé
Auteurs :	Asadishad, Bahareh, Auteur ; Manouchehr Vossoughi, Auteur ; Alemzadeh, Iran, Auteur
Année de publication :	2010
Article en page(s) :	pp 1958–1963
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Doxorubicin Nanoparticles Polyethylene glycol.
Résumé :	Doxorubicin-loaded nanocarriers were produced employing folate-modified polyethylene glycol (PEG)-functionalized gold nanoparticles for targeted delivery to positive folate-receptor cancer cells. Doxorubicin and folate were, respectively, conjugated to activated-folate and activated-PEG. The conjugates formed doxorubicin nanocarrier with an average size of 12 nm in diameter. The drug release response of functionalized gold nanoparticles was characterized by an initial rapid drug release followed by a controlled release. The doxorubicin nanocarriers showed higher cytotoxic effect on folate-receptor-positive cells (KB cells) than folate-receptor-negative cells (A549 cells). Cell viability in healthy cells (HFF cells) in drug-loaded nanoparticles was higher compared to free doxorubicin. These nanocarriers might offer a cancer therapy with high targeting efficiency and lower side effects.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9011479

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1953–1957

Titre :	Electrospinning of cellulose acetate phthalate from different solvent systems
Type de document :	texte imprimé
Auteurs :	Olaru, Niculae, Auteur ; Olaru, Liliana, Auteur
Année de publication :	2010
Article en page(s) :	pp 1953–1957
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Electrospinning Solvent systems.
Résumé :	Electrospinning of cellulose acetate phthalate (CAP) has been performed from an acetone−water mixture 85/15 (v/v), 2-methoxyethanol, and a 2-methoxyethanol−acetone−water mixture 50/42.5/7.5 (v/v/v). It has been observed that, at low polymer concentration (12.5%, w/v), a solution in an acetone−water mixture 85/15 (v/v) gave uniform fibers with diameters lower than 500 nm, whereas in 2-methoxyethanol fine particles that look like void hemispheres were obtained. The morphology of the electrospun CAP from this solvent gradually changed by increasing the polymer concentration and beaded fibers and fibers without beads have been produced from solutions of 25% (w/v) and 35% (w/v), respectively. Smooth filaments with no beads and diameters of about 600 nm could be obtained from a solution of CAP in the ternary system 2-methoxyethanol−acetone−water 50/42.5/7.5 (v/v/v) at a polymer concentration of 25% (w/v). The electrospinnability of CAP from 2-methoxyethanol-containing solvents was better than that from the acetone−water mixture 85/15 (v/v).
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901427f

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1947–1952

Titre :	Dispersion of fatty acid surface modified ceria nanocrystals in various organic solvents
Type de document :	texte imprimé
Auteurs :	Toshihiko Arita, Auteur ; Ueda, Yu, Auteur ; Minami, Kimitaka, Auteur
Année de publication :	2010
Article en page(s) :	pp 1947–1952
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Nanocyrstals Organic solvents.
Résumé :	Ceria (CeO2) nanocyrstals which could be transparently dispersed in several organic solvents were synthesized by organic-ligand-assisted hydrothermal synthesis. We have studied the dispersity of the nanocrystals into typical organic solvents using dynamic light scattering (DLS) measurement. The mean diameter of the dispersant (the nanocrystals’ cluster) varied with changing the solvent species. When the solubility parameter (SP) values of the solvent and the modifier were comparable to each other, the nanocrystals tended to disperse in the solvent with the initial particle size. One of the three-dimensional SPs, i.e., the Hansen solubility parameters, brought more detailed understanding of the mechanism of the dispersion of the surface modified nanocrystals. Because of the dense modifier layer on the surface of the ceria nanocrystals, the hydrogen bonding ability of the solvent was not the dominant factor to determine dispersion of the surface modified nanocrystals. The dispersion and polar factors of the Hansen SPs could describe the ideal condition of perfect dispersion of the surface modified CeO2 nanocrystals.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901319c

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1937–1946

Titre :	Thermodynamics of binary and ternary solutions of multivalent electrolytes with formation of 1:1 and 1:2 complexes, within the mean spherical approximation
Type de document :	texte imprimé
Auteurs :	Torres-Arenas, José, Auteur ; Simonin, Jean-Pierre, Auteur ; Olivier Bernard, Auteur
Année de publication :	2010
Article en page(s) :	pp 1937–1946
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Thermodynamics Binary ternary solutions Electrolytes.
Résumé :	The mean activity (γ±) and osmotic (Φ) coefficients for binary and ternary aqueous solutions of trivalent electrolytes (mainly made up of lanthanide salts) are described in the framework of the primitive model of ionic solutions, using the binding mean spherical approximation (BiMSA). This model, based on the Wertheim formalism, accounts for (chemical or electrostatic) association of ions. In this work, the multivalent cation and the anion are allowed to form 1:1 (pairs) and 1:2 (trimers) complexes. Expressions for γ± and Φ are given which satisfy the Gibbs−Duhem relation. The model involves concentration-dependent cation size and effective relative permittivity, variations that can be interpreted in terms of solvent effects. The theory is applied to aqueous solutions of binary and ternary mixtures at 25 °C with common anion.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901323x

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1931–1936

Titre :	Hydrodynamic considerations in an external loop airlift reactor with a modified downcomer
Type de document :	texte imprimé
Auteurs :	Jones, Samuel T., Auteur ; Heindel, Theodore J., Auteur
Année de publication :	2010
Article en page(s) :	pp 1931–1936
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Gas Hydrodynamic Loop airlift reactor.
Résumé :	Gas holdup and superficial liquid velocity in the downcomer and riser are studied for an external loop airlift reactor with a downcomer-to-riser area ratio of 1:16. Two downcomer configurations are investigated over a range of superficial gas velocities (0.5 ≤ UG ≤ 20 cm/s) using three aeration plate open area ratios (A = 0.62, 0.99, and 2.22%). These results are compared to a bubble column operated with similar operating conditions. Gas holdup in both the riser and downcomer are found to increase with increasing superficial gas velocity. Results show that riser gas holdup varies slightly with downcomer configuration, while a considerable variation is observed for downcomer gas holdup. The superficial liquid velocity varies considerably for the two downcomer configurations and is a function of superficial gas velocity and flow conditions in the downcomer. Observed variations are independent of aeration plate open area ratio.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901311r

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1920–1930

Titre :	Model to predict the concentration of ultradispersed particles immersed in viscous media flowing through horizontal cylindrical channels
Type de document :	texte imprimé
Auteurs :	Herbert Loria, Auteur ; Pedro Pereira-Almao, Auteur
Année de publication :	2010
Article en page(s) :	pp 1920–1930
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Ultradispersed particles Viscous Horizontal cylindrical channels.
Résumé :	An innovative way to upgrade heavy crude oils is the use of ultradispersed catalysts; however, an adequate mathematical expression that describes the mass transfer on this process is still missing. This paper studies the separation and suspension of ultradispersed particles based on their motion through diverse viscous media enclosed in horizontal cylindrical channels. A time-dependent, three-dimensional convective−dispersive model which simulates the transient deposition and suspension of these particles immersed in viscous media inside a horizontal cylinder was developed and solved. This model was also experimentally validated, and its results unveiled the particle and fluid media properties that are necessary to control particle deposition. The experiments were performed using Fe2O3 particles (average sizes of 198 nm) immersed in water−glycerol mixtures with different densities and viscosities subject to different fluid velocities. The effect of the fluid medium properties, the initial particle concentration, and fluid velocity on the dispersion coefficient was also studied.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901232p

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1910–1919

Titre :	Investigation of immiscible and miscible foam for enhancing oil recovery
Type de document :	texte imprimé
Auteurs :	R. Farajzadeh, Auteur ; Andrianov, A., Auteur ; P. L. J. Zitha, Auteur
Année de publication :	2010
Article en page(s) :	pp 1910–1919
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Immiscible miscible foam Oil recovery.
Résumé :	We report the study of flow of CO2 and N2 foam in natural sandstone cores containing oil with the aid of X-ray computed tomography. The study is relevant for enhanced oil recovery (EOR). The cores were partially saturated with oil and brine (half top) and brine only (half bottom) to mimic the water−oil transition occurring in oil reservoirs. The CO2 was used either under subcritical conditions (P = 1 bar) or under supercritical (immiscible (P = 90 bar) and miscible (P = 137 bar)) conditions, whereas N2 remained subcritical. Prior to gas injection the cores were flooded with several pore volumes of water. In a typical foam experiment water flooding was followed by the injection of 1−2 pore volumes of a surfactant solution with alpha olefin sulfonate (AOS) as the foaming agent. We visually show how foam propagates in a porous medium containing oil. At low-pressure experiments (P = 1 bar) in the case of N2, weak foam could be formed in the oil-saturated part. Diffused oil bank is formed ahead of the foam front, which results in additional oil recovery, compared to pure gas injection. CO2 hardly foams in the oil-bearing part of the core, most likely due to its higher solubility. Above the critical point (P = 90 bar), CO2 injection following the slug of surfactant reduces its mobility when there is no oil. Nevertheless, when the foam front meets the oil, the interface between gas and liquid disappears. The presence of the surfactant (when foaming supercritical CO2) did not affect the oil recovery and pressure profile, indicating the detrimental effect of oil on foam stability in the medium. However, at miscible conditions (P = 137 bar), injection of surfactant prior to CO2 injection significantly increases the oil recovery.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901109d

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1905–1909

Titre :	Evaluation of the multiphase behavior in binaries using a new technique for describing solid phases based on the soave−redlich−kwong equation of state
Type de document :	texte imprimé
Auteurs :	Yang, Quan, Auteur ; Zhu, Shen-Lin, Auteur ; Zhao, Tian-Sheng, Auteur
Année de publication :	2010
Article en page(s) :	pp 1905–1909
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Multiphase behavior binaries Equation state.
Résumé :	In the petroleum industry, knowledge of phase behavior is essential to solve many problems, such as the design of the catalytic cracking of heavy oil. The catalyst tends to lose activity as a result of the formation of the solid phase, so the calculation of multiphase behavior of systems containing solid phases will serve to solve the problem. The Soave−Redlich−Kwong equation of state is widely employed to evaluate multiphase behavior, but cubic equations of state are incapable of calculating the properties of solid phases and thus cannot evaluate the multiphase behavior of systems containing solid phases. In this research, a new technique for describing the solid phase has been developed. The multiphase behavior of propane binaries with ployaromatic hydrocarbons was then explored. To evaluate the critical end point, which is difficult to calculate, an algorithm combining the method of Heidemann and Khalil ( AIChE J. 1980, 26, 769−780) to compute the critical point and the tangent-plane criterion was developed previously (Yang et al. Ind. Eng. Chem. Res. 2009, 48, 6877−6881). Setting the initial guesses with the values at the obtained critical end points, the three-phase loci were then computed successfully. The calculation results show that the three-phase loci terminate at a lower critical end point (LCEP), which is wrong according to the experimental data. To correct this mistake, the newly developed technique was employed, and the quadruple points where the three-phase loci really end were evaluated successfully.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9011003

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1900–1904

Titre :	Effect of CuO nanoparticles in enhancing the thermal conductivities of monoethylene glycol and paraffin fluids
Type de document :	texte imprimé
Auteurs :	Moghadassi, A. R., Auteur ; Hosseini, S. Masoud, Auteur ; Henneke, Dale E., Auteur
Année de publication :	2010
Article en page(s) :	pp 1900–1904
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	CuO nanoparticles Thermal conductivities Monoethylene glycol Paraffin Fluids.
Résumé :	The effect of CuO nanoparticles on the thermal conductivities of paraffin and monoethylene glycol (MEG) was investigated. An enhancement in the effective thermal conductivity was found for both fluids. This enhancement was studied with regard to various factors: nanoparticle concentration, nanoparticle size, and base-fluid type. For both base fluids, an improvement in thermal conductivity was found as nanoparticle concentration increased; this was attributed to an increase in particle-to-particle interactions. It was also found that, as the particle size was reduced, there was also an improvement in the thermal conductivities of the fluids. A reduction in nanoparticle size leads to an increase in the Brownian motion of the particles, which also causes more particle-to-particle interactions. The role that the base fluid plays in the observed enhancement is complex. Lower fluid viscosities are believed to contribute to greater enhancement, but a second effect, the interaction of the fluid with the nanoparticle surface, can be even more important. Nanoparticle−liquid suspensions generate a shell of organized liquid molecules on the particle surface. These organized molecules more efficiently transmit energy, via phonons, to the bulk of the fluid. The efficient energy transmission results in enhanced thermal conductivity. The experimentally measured thermal conductivities of the suspensions were compared to a variety of models. None of the models were found to adequately predict the thermal conductivities of the nanoparticle suspensions.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901060e

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1883–1899

Titre :	Modeling the fluid phase behavior of carbon dioxide in aqueous solutions of monoethanolamine using transferable parameters with the SAFT-VR approach
Type de document :	texte imprimé
Auteurs :	Mac Dowell, N., Auteur ; Llovell, F., Auteur ; Adjiman, C. S., Auteur
Année de publication :	2010
Article en page(s) :	pp 1883–1899
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Carbon dioxide Aqueous solutions Fluid phase.
Résumé :	The current method of choice for large-scale carbon dioxide (CO2) capture is amine-based chemisorption, typically in packed columns, with the benchmark solvent being aqueous solutions of a primary alkanolamine: monoethanolamine (MEA). In this contribution, we use the statistical associating fluid theory for potentials of variable range (SAFT-VR) to describe the fluid phase behavior of MEA + H2O + CO2 mixtures. The physical chemistry of CO2 in aqueous solutions of amines is highly complex owing to the chemical equilibria between the various species that are formed in solution at ambient conditions. We explicitly consider the multifunctional nature of MEA and, in so doing, are able to represent accurately the thermodynamic properties and phase equilibria of this highly nonideal mixture over a wide range of temperatures, pressures, and compositions. MEA is modeled as an associating chain molecule formed from homonuclear spherical segments with six distinct association sites incorporated to mediate the asymmetric hydrogen bonding interactions exhibited by this molecule. The models for H2O and CO2 are taken from previous work. In order to describe the chemisorption, which is the key to the CO2 capture process, two additional effective sites are incorporated on the otherwise nonassociating CO2 molecule to describe the chemical interaction between the MEA and CO2, so that the correct maximal stoichiometry of two amine molecules per CO2 molecule is retained. The vapor−liquid phase equilibria of the various binary mixtures and of the MEA + H2O + CO2 ternary mixture are accurately described with our approach, including the degree of absorption of CO2 in the solvent for wide ranges of temperature and pressure. This suggests that the underlying complexity of the chemical equilibria associated with this system are correctly captured by the model and provides great promise for the modeling of the overall process of CO2 capture.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901014t

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1872–1882

Titre :	Calculation of critical points of thermodynamic mixtures with differential evolution algorithms
Type de document :	texte imprimé
Auteurs :	Henderson, Nélio, Auteur ; Sacco, Wagner F., Auteur ; Barufatti, Nelza E., Auteur
Année de publication :	2010
Article en page(s) :	pp 1872–1882
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Thermodynamic Differential evolution algorithms.
Résumé :	In this article, we use differential evolution (DE) algorithms for the first time in the prediction of critical points of thermodynamic mixtures. Despite the name, DE algorithms are direct search populational techniques that do not use derivatives. We work with four different versions of DE algorithms and propose a variant for calculating more than one critical point. The differential evolution algorithms are tested on several multicomponent systems, and the new variant is capable of obtaining multiple solutions on different petroleum fluids.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://fr.babelfish.yahoo.com/translate_txt

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1859–1871

Titre :	Pilot-scale gasification of corn stover, switchgrass, wheat straw, and wood : 1. parametric study and comparison with literature
Type de document :	texte imprimé
Auteurs :	Carpenter, Daniel L., Auteur ; Bain, Richard L., Auteur ; Davis, Ryan E., Auteur
Année de publication :	2010
Article en page(s) :	pp 1859–1871
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Gasification Corn stover Switchgrass.
Résumé :	A parametric study of the gasification of four feedstocks (corn stover, switchgrass, wheat straw, and wood) has been performed on an experimental, pilot-scale (0.5 ton/day) gasification facility. A comparison was made of the performance of the gasifier as a function of feedstock, in terms of the syngas production and composition. In these experiments, pelletized feedstock was used, so that the shapes and sizes of the materials did not influence the results. A total of 22 statistically designed experimental conditions were examined for each feedstock, including the effects of varying the temperature of the fluidized bed, the temperature of the secondary thermal cracker, and the steam-to-biomass ratio. For each experimental condition, the permanent-gas composition was measured continuously by gas chromatography (GC). Tars were measured continuously using a molecular-beam mass spectrometer (MBMS). Sulfur analysis by GC was also conducted for three of the feedstocks studied. The results from this study show that there were significant differences between the feedstocks studied in terms of light gases formed, but less apparent variation in tar formation. In general, the variations in products were smaller at higher temperatures. A preliminary analysis of gasifier efficiency was performed using an Aspen Plus process model for selected gasification conditions. Finally, a comparison was made between the results of this work and other similar biomass gasification studies.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900595m

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1848–1858

Titre :	Experimental study of a dual reflux enriching pressure swing adsorption process for concentrating dilute feed streams
Type de document :	texte imprimé
Auteurs :	McIntyre, J. A., Auteur ; Armin D. Ebner, Auteur ; Ritter, J. A., Auteur
Année de publication :	2010
Article en page(s) :	pp 1848–1858
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Pressure swing adsorption process Dilute feed streams.
Résumé :	A dual reflux (DR) enriching pressure swing adsorption (PSA) process with two beds and an intermediate feed located at z/L = 0.5 was studied experimentally for concentrating a dilute feed of ethane in N2 using MeadWestvaco BAX-1500 activated carbon. A five-step cycle was used with feed, light reflux, and heavy reflux steps carried out simultaneously, and cocurrent depressurization and heavy product pressurization steps carried out simultaneously during different segments of the cycle. A parametric study showed that the light reflux flow rate, feed/heavy reflux step time, heavy product flow rate, and ethane feed mole fraction all had significant effects on the process performance in terms of purity and recovery. It also showed that it was relatively easy to concentrate ethane using a pressure ratio of only 7. The average of 19 runs with an ethane feed concentration of 1.38 vol % gave an ethane enrichment of 45.8 (63.2 vol %) and ethane recovery of 84%, while producing N2 at high purity (99.8 vol %) and recovery (>99%). Overall, this study showed that a DR enriching PSA process is well suited for concentrating dilute hydrocarbon feed streams and producing the light component at both high purity and recovery.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901266y

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1844–1847

Titre :	Experimental determination of vapor−liquid equilibria and excess enthalpy data for the binary system 2-methyl-1-butanol + 3-methyl-1-butanol as a test mixture for distillation columns
Type de document :	texte imprimé
Auteurs :	Thiede, Sarah, Auteur ; Horstmann, Sven, Auteur ; Meisel, Thomas, Auteur
Année de publication :	2010
Article en page(s) :	pp 1844–1847
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Vapor liquid Binary system Methyl butanol Distillation columns.
Résumé :	Isothermal vapor−liquid equilibrium data for 2-methyl-1-butanol + 3-methyl-1-butanol were measured using a static synthetic method at temperatures of 343.15, 353.69, 368.15, and 404.45 K. Additionally, excess enthalpy (HE) data for the system were measured with an isothermal flow calorimeter at 363.13 K. The experimental data were correlated using temperature dependent interaction parameters for the NRTL model which were fitted to all measured data. The system was chosen as a test system for distillation columns.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9012453

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1837–1843

Titre :	Article high silica zeolites as an alternative to weak base adsorbents in succinic acid recovery
Type de document :	texte imprimé
Auteurs :	Efe, Cagri, Auteur ; Van der Wielen, Luuk A. M., Auteur ; Straathof, Adrie J. J., Auteur
Année de publication :	2010
Article en page(s) :	pp 1837–1843
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	High silica zeolites Succinic acid.
Résumé :	Initial studies were performed on succinic acid adsorption from aqueous solutions by zeolite powders. CVB-28014 (high-silica ZSM-5) showed higher equilibrium loadings (up to 0.16 g/g) than CBV-901 and CP811C-300, and was used for follow up studies. In the presence of Na+ counterions, the succinic acid adsorption decreased in parallel with the succinic acid dissociation, but the adsorbent also showed some affinity toward sodium hydrogensuccinate with selectivities in the range 10−20 toward succinic acid. The presence of acetic acid resulted in lower succinic acid loadings but the capacities remained sufficient for efficient recovery. The selectivity between succinic acid and acetic acid ranged from 1 to 6. Increasing the temperature to 70 °C reduced the equilibrium loadings, but in ethanol the succinic acid loadings showed a more significant drop. Therefore, regeneration might be achieved by using an adsorption-competitive solvent like ethanol. The current results suggest that this may lead to an attractive option for the recovery of succinic acid from fermentation media. Hydrophobic rather than ionic interactions are used, thus avoiding regeneration involving acid and base and the associated waste salt production.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901110b

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1832–1836

Titre :	Laboratory studies on the preparation procedures of alumina converted from aluminum citrate
Type de document :	texte imprimé
Auteurs :	Yu, Zhanglong, Auteur ; Lv, Yajing, Auteur ; Yongmei Chen, Auteur
Année de publication :	2010
Article en page(s) :	pp 1832–1836
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Alumina industry Citric acid.
Résumé :	It is a promising technology in the alumina industry using citric acid to extract aluminum from clay or kaolin and obtain the solution of aluminum citrate (AlCit). But the prerequisite of the preparation procedure of alumina started from AlCit is that citric acid should be recycled. A process named AlCit−Dawsonite−alumina is proposed in this paper. By using Dawsonite as an intermediate, citrate groups could be separated and reused. The process was verified in laboratory scale: First, Dawsonite was precipitated from AlCit solution with a satisfied purity and conversion rate. Second, Dawsonite was transformed to alumina with low Na content through the two proposed methods. The structure and purity of the intermediate of Dawsonite and products of alumina were characterized by infrared, thermogravimetric−differential thermal analysis, X-ray diffraction, scanning electron microscopy, and inductively coupled plasma. The results show that the synthesized Dawsonite has a great purity and perfect crystallinity; and the Na content of the final alumina product is lower than 0.2%.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901400r

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1822–1831

Titre :	Minimization of Energy in Reverse Osmosis Water Desalination Using Constrained Nonlinear Optimization
Type de document :	texte imprimé
Auteurs :	Li, Mingheng, Auteur
Année de publication :	2010
Article en page(s) :	pp 1822–1831
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Osmosis water desalination Nonlinear optimization.
Résumé :	This work focuses on the minimization of energy in reverse osmosis water desalination. First, a set of dimensionless parameters were derived to characterize the reverse osmosis desalination process. On the basis of the assumptions of constant pump efficiency and no pressure change in the retentate, the minimization of energy cost per volume of produced permeate or specific energy consumption (SEC) for three different reverse osmosis modules (single-stage, two-stage, and single-stage with an energy recovery device (ERD)) were then formulated and solved as constrained nonlinear optimization problems. Without ERD, the optimal solution to SEC normalized by the feed salinity was solely dependent on a dimensionless parameter γ that is comprised of the membrane area, hydraulic permeability, feed rate, and salinity. In the thermodynamic limit where γ approaches infinity, the minimal SEC approaches 4 and 3.596 times the feed salinity and the fractional recovery approaches 0.5 and 0.574 for single-stage and two-stage reverse osmosis modules, respectively. However, the water yield approaches zero in both cases. With an ERD, the SEC can be further reduced to the feed salinity while the fractional recovery approaches zero. It is also shown that the SEC flattens out quickly as γ increases, and a cutoff of γ (around 0.5−1.5 for one-stage and 1−3 for two-stage membrane modules) can be used to achieve a reasonable water yield as well as a low SEC slightly above the theoretical global minimum.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9012826

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1812–1821

Titre :	Fisher information on the performance of dynamic systems
Type de document :	texte imprimé
Auteurs :	Rico-Ramirez, Vicente, Auteur ; Reyes-Mendoza, Miguel A., Auteur ; Quintana-Hernandez, Pedro A., Auteur
Année de publication :	2010
Article en page(s) :	pp 1812–1821
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Fisher information Dynamic systems.
Résumé :	Recent attempts to develop sustainability theory propose the use of Fisher information as a sustainability index. The approach has been shown to be suitable for the analysis of ecological models, including dynamic simulations as well as optimal control problems where the objective function involves maximizing or minimizing Fisher information. Nevertheless, Fisher information can also be interpreted as a measure of the degree of variability of a dynamic system. The goal of this work is two-fold. First, we study the scope of using the concept of Fisher information as a sustainability index in dynamic systems different in nature from ecological systems. Then we study the behavior of Fisher information in terms of the variability and performance of the dynamic system rather than using it as a sustainability index. The results of three case studies are presented, including two chemical engineering applications (a continuous crystallization system and a series of three continuous stirred tank reactors) and a dynamic model of immunotherapy (therapeutic optimization). We perform parametric analyses, evaluating the behavior of the value of Fisher information against significant model parameters. In general, although its usefulness as a sustainability index might be difficult to interpret and elucidate in some cases, Fisher information not only can indeed be related to the degree of variability of any dynamic system, but also provides useful insights with potential application in process control.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901220w

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1799–1811

Titre :	An integrated CP-based approach for scheduling of processing and transport units in pipeless plants
Type de document :	texte imprimé
Auteurs :	Zeballos, Luis J., Auteur ; Carlos A. Méndez, Auteur
Année de publication :	2010
Article en page(s) :	pp 1799–1811
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Pipeless plants Integrated CP based.
Résumé :	This work addresses the simultaneous production and material handling scheduling problem typically arising in pipeless plants with alternative layouts. An integrated constraint programming (CP) methodology, comprising both a detailed CP model and a suitable search strategy, is developed to address manufacturing environments in which multiple products with different recipes are to be produced. The general pipeless plant topology involves fixed processing stations and a limited number of moveable vessels used to transfer the material between consecutive stations, according to the predefined product recipes. Because of the high combinatorial complexity of the problem, an efficient search methodology is also presented to significantly accelerate the search and reduce the computational effort. The applicability of the proposed integrated CP methodology (model + search strategy) is successfully tested with several challenging examples taken from literature.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901176n

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1792–1798

Titre :	Leaching characteristics of hanford ferrocyanide wastes
Type de document :	texte imprimé
Auteurs :	Edwards, Matthew K., Auteur ; Fiskum, Sandra K., Auteur ; Shimskey, Rick W., Auteur
Année de publication :	2010
Article en page(s) :	pp 1792–1798
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Leaching Ferrocyanide wastes.
Résumé :	A series of leach tests were performed on actual Hanford Site tank wastes in support of the Hanford Tank Waste Treatment and Immobilization Plant (WTP). The samples were targeted composite slurries of high-level tank waste materials representing major complex, radioactive, tank waste mixtures at the Hanford Site. Using a filtration/leaching apparatus, sample solids were concentrated, caustic leached, and washed under conditions representative of those planned for the Pretreatment Facility in the WTP. Caustic leaching was performed to assess the mobilization of aluminum (as gibbsite, Al[OH]3, and boehmite AlO[OH]), phosphates [PO43−], chromium [Cr3+], and, to a lesser extent, oxalates [C2O42−]). Ferrocyanide waste released solid phase 137Cs during caustic leaching; this was antithetical to the other Hanford waste types studied. Previous testing on ferrocyanide tank waste focused on the aging of the ferrocyanide salt complex and its thermal compatibilities with nitrites and nitrates. Few studies, however, examined cesium mobilization in the waste. Careful consideration should be given to the pretreatment of ferrocyanide wastes in light of this new observed behavior, given the fact that previous testing on simulants indicates a vastly different cesium mobility in this waste form. The discourse of this work will address the overall ferrocyanide leaching characteristics as well as the behavior of the 137Cs during leaching.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9010

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1779–1791

Titre :	Object-oriented disjunctive programming with a nested heuristic and gradient-based solver for chemical process synthesis
Type de document :	texte imprimé
Auteurs :	Tian, Daqing, Auteur ; Zhu, Lingyu, Auteur ; Xi Chen, Auteur
Année de publication :	2010
Article en page(s) :	pp 1779–1791
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Disjunctive programming Chemical process synthesis.
Résumé :	The generalized disjunctive programming (GDP) model has been proposed and applied in the past decade as an alternative to the mixed integer nonlinear programming (MINLP) model because it has the advantages of being straightforward when used in conditional modeling and being able to reduce the complexity in the sub-NLP. In this paper, we introduced an improved variant of the traditional GDP model, otherwise known as the object-oriented disjunctive programming (ODP) model. Such a method helps generate well-posed sub-NLP, thereby improving the solving process. A nested method combining the heuristic algorithm and gradient-based optimizer is also proposed to solve the GDP and ODP. It is a two-layer method, wherein a heuristic algorithm performs master iterations in the outer-loop when dealing with the Boolean variables, and a gradient-based NLP solver is applied in the inner-loop when dealing with the sub-NLP. Excellent performance has been demonstrated by applying the modeling and solving methods into the process synthesis of heat exchanger networks (HENs) and water networks (WNs).
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901010a

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1770–1778

Titre :	A nonlinear probabilistic method for process monitoring
Type de document :	texte imprimé
Auteurs :	Ge, Zhiqiang, Auteur ; Zhihuan Song, Auteur
Année de publication :	2010
Article en page(s) :	pp 1770–1778
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Nonlinear probabilistic Monitoring nonlinear.
Résumé :	To improve monitoring performance, the traditional principal component analysis (PCA) based process monitoring approach has been extended to its probabilistic counterpart. However, its ability is limited in linear processes. This paper proposes a nonlinear probabilistic method for monitoring nonlinear processes, which is based on generative topographic mapping (GTM). Similar to traditional methods, the monitoring statistic and its corresponding fault diagnosis approach have both been developed. Two case studies are provided to evaluate the feasibility and efficiency of the proposed method.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900858v

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1762–1769

Titre :	Application of dynamic optimization techniques for poly(β-hydroxybutyrate) production in a fed-batch bioreactor
Type de document :	texte imprimé
Auteurs :	Lopez, Jimmy A., Auteur ; Verónica Bucalá, Auteur ; Villar, Marcelo A., Auteur
Année de publication :	2010
Article en page(s) :	pp 1762–1769
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Dynamic optimization Poly β-hydroxybutyrate Fed batch bioreactor.
Résumé :	Poly(β-hydroxybutyrate), PHB, is a microbial biopolymer produced by bacteria under unbalanced culture conditions. Such unbalanced conditions can be easily reached in a fed-batch bioreactor; therefore, it is important to know the system’s behavior as well as its constraints to induce unbalanced conditions that allow the optimization of feeding profiles and, consequently, PHB productivity. In this work, dynamic optimization has been applied to maximize PHB productivity in a fed-batch bioreactor. Optimal feeding profiles of carbon and nitrogen sources, as well as their respective concentrations, were obtained using gPROMS (generalized process modeling system). When there is reliable bioreaction kinetics available, dynamic optimization becomes a very valuable tool for predicting optimal operating conditions to maximize PHB productivity, with a considerable reduction in time and experimental costs.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9006547

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1749–1761

Titre :	A Systematic approach for the design of optimal monitoring systems for large scale processes
Type de document :	texte imprimé
Auteurs :	Zumoffen, David, Auteur ; Basualdo, Marta, Auteur
Année de publication :	2010
Article en page(s) :	pp 1749–1761
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Optimal monitoring systems Large scale processes.
Résumé :	In this work a new concept for designing an efficient monitoring system for large scale chemical plants is presented. It is considered that the monitoring problem must be solved integrated with the optimal sensor location together with the plant-wide control structure design. The solution of these problems involves deciding among a great number of possible combinations between the input−output variables. It is done supported by the application of genetic algorithm (GA). The key new idea is to propose an adequate objective function, within the GA, that takes into account a fault detectability index based on combined statistics. Additionally, by using a specific penalty function, it is possible to drive the search to the less expensive structure, that is by using the lowest number of sensors. The well-known benchmark case of the Tennessee Eastman plant (TE) is chosen for testing this methodology and for discussion purposes. Since several authors have studied the TE case, the results obtained here can be rigorously compared with those already published. All of the previous works considered that every TE output variables were available for the abnormal events detection for designing the monitoring system.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9017836

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1737–1748

Titre :	Robust optimization model for crude oil scheduling under uncertainty
Type de document :	texte imprimé
Auteurs :	Wang, Jishuai, Auteur ; Rong, Gang, Auteur
Année de publication :	2010
Article en page(s) :	pp 1737–1748
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Crude oil Optimization.
Résumé :	In this article, a two-stage robust model is proposed to solve the crude oil scheduling problem under uncertain conditions. The first stage of the model is developed using chance-constrained programming and fuzzy programming that can be transformed into the deterministic counterpart problem, whereas the second-stage is scenario-based. Through the combination of the approaches, the two-stage model can deal with uncertain parameters with both continuous and discrete probability distributions within a finite number of scenarios. The model was tested on several small examples and an industrial-size case. Uncertainties were introduced in ship arrival times and fluctuating product demands. The computational results demonstrate the effectiveness and robustness of the proposed approach. The tradeoff between solution robustness and model robustness was also analyzed.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900358z

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1732–1736

Titre :	Preparation and characterization of calcium stearate powders and films prepared by precipitation and langmuir−blodgett techniques
Type de document :	texte imprimé
Auteurs :	Gonen, Mehmet, Auteur ; Ozturk, Serdar, Auteur ; Balkose, Devrim, Auteur
Année de publication :	2010
Article en page(s) :	pp 1732–1736
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Calcium stearate Langmuir blodgett techniques.
Résumé :	The preparation of calcium stearate (CaSt2) using precipitation and Langmuir−Blodgett techniques was investigated in this study. While sodium stearate and calcium chloride were used in the precipitation process, calcium stearate nanofilms were produced from stearic acid and calcium chloride in sodium borate buffer with the Langmuir−Blodgett technique. Fourier transform infrared (FTIR) spectroscopy indicated carboxylate bands at 1577 and 1543 cm−1 in equal intensity in the powder form, but the films had a higher intensity 1577 cm−1 band than the 1543 cm−1 band. This showed the calcium ions associated with the COO− ions in the monodendate and bidendate structures in powders, and it was mainly in the bidendate structure in films. While characteristic peaks of CaSt2 at 2θ values of 6.40° and 19.58° were obtained in the X-ray diffraction (XRD) pattern of the dried powdered product, no sharp peaks were present in the 13 layer CaSt2 film. From scanning electron microscopy (SEM) micrographs, it was seen that calcium stearate powder had lamellar structure and the average particle size was 600 nm. The AFM picture of the CaSt2 film indicated the surface was not smooth with a peak to valley distance of 6 nm.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901437d

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1725–1731

Titre :	Redox activity and NO storage capacity of MnOx−ZrO2 with enhanced thermal stability at elevated temperatures
Type de document :	texte imprimé
Auteurs :	Zhao, Qiang, Auteur ; Shih, Wan Y., Auteur ; Chang, Hsiao-Lan, Auteur
Année de publication :	2010
Article en page(s) :	pp 1725–1731
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Oxides MnOx ZrO2 Redox Heat treatment.
Résumé :	MnOx−ZrO2 mixed oxides are very active catalysts for oxidation or combustion applications due to their excellent redox activity. Recently, they have also shown promising results for NO storage in emission control. Despite the versatile applications, a systematic study on the redox activity and NO storage capacity of MnOx−ZrO2 with their thermal stability at high temperatures is still missing. In this paper the evolution of these properties in the temperature range 500−900 °C is reported. It was found that there is a dramatic deterioration in redox activity and NO storage capacity when the calcination temperature increases to 900 °C, which is attributed to the loss of thermal stability at this high temperature. On the other hand, doping with La can hinder the sintering of MnOx−ZrO2 particles and therefore increase the surface area of the mixed oxides calcined at 900 °C. Correspondingly, La-doped MnOx−ZrO2 mixed oxides show much improved redox activity and NO storage capacity even after 900 °C heat treatment.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901234x

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1711–1724

Titre :	Adsorption and coalescence in mixed-surfactant systems : air−water interface
Type de document :	texte imprimé
Auteurs :	Suryanarayana, G., Auteur ; Ghosh, Pallab, Auteur
Année de publication :	2010
Article en page(s) :	pp 1711–1724
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Adsorption Air water interface.
Résumé :	Mixtures of ionic and nonionic surfactants have a wide range of industrial and household applications. The properties of the monolayer formed by such systems at the air−water interface depend on the interactions between the surfactants. The presence of salt influences the interactions between the surfactants in the monolayer as well as in the micelle. In this work, these interactions in the presence and absence of a 1:1 salt were studied using nonideal solution theory. An anionic surfactant, a cationic surfactant, and a nonionic surfactant were used. The stability of foams was significantly affected by the interactions between the surfactants. To study this effect, the coalescence of air bubbles in the mixed-surfactant systems was studied and compared with that in the corresponding single-surfactant systems. The effect of salt on the coalescence time was also studied. The results were analyzed using the film drainage and stochastic theories of coalescence. Seven film drainage models were employed to predict the coalescence time, and the values predicted by these models were compared with the experimental data. The parameters of the stochastic model were analyzed based on the properties of the systems.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9012216

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1703–1710

Titre :	Dielectric properties of free-radical polymerizations : molecularly symmetrical initiators during thermal decomposition
Type de document :	texte imprimé
Auteurs :	Smith, Alastair D., Auteur ; Lester, Edward, Auteur ; Thurecht, Kristofer J., Auteur
Année de publication :	2010
Article en page(s) :	pp 1703–1710
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Dielectric properties Polymerizations Thermal decomposition.
Résumé :	The first dedicated study investigating how the dielectric properties of free-radical initiators vary with both temperature and time is reported herein. The materials tested were chosen because they are standard initiators that are widely used by both industry and academia. Initially, each initiator was subjected to thermogravimetric analysis under the same temperature/time profiles, which reflects the mass lost from the materials when subjected to conventional heating. By comparing these data to the dielectric properties, we found that both the melting and decomposition points are directly related to large changes in the dielectric properties of the sample. We then used these data to investigate the likelihood of electromagnetic fields at microwave frequencies being capable of exerting an effect on the molecular decomposition of these initiating species, through a polarization−relaxation mechanism, and whether this effect could potentially alter the mechanistic pathways taken in free-radical polymerization chemistry. Finally, we considered whether direct molecular-based effects of electromagnetic fields at microwave frequencies on such initating species are responsible for the empirical observations related to polymerization that have been reported in the literature, such as rate and molecular-weight enhancements.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901201h

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1697–1702

Titre :	Preparation of well-dispersed silver nanoparticles for oil-based nanofluids
Type de document :	texte imprimé
Auteurs :	Li, Dan, Auteur ; Hong, Biyuan, Auteur ; Fang, Wenjun, Auteur
Année de publication :	2010
Article en page(s) :	pp 1697–1702
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Nanoparticles Nanofluids Oil based.
Résumé :	Self-assembled silver nanoparticles with an average diameter of 5 nm have been successfully fabricated by reduction of Ag+ with ascorbic acid in the mixture of water, alkylamine, and oleic acid. Thermogravimetry (TG), differential scanning calorimetry (DSC), and contact angle measurements indicate that oleic acid molecules are well capped on the silver nanoparticles. The effects of temperature and reaction-medium pH on the morphology and composition of the silver nanoparticles are discussed. A decrease in pH leads to a tendency to produce silver nanorods and nanospheres. The temperature can affect the thickness of the organic layer on the surfaces of the silver nanoparticles. The stabilities of the silver nanoparticles in the nanofluids were monitored at different temperatures. Thermal conductivity enhancements were determined in kerosene-based nanofluids with the prepared silver nanoparticles. The surface-capped silver nanoparticles exhibited excellent dispersity in kerosene and conventional organic solvent such as n-hexane and chloroform. The highly dispersible silver nanoparticles are therefore suitable for the preparation of oil-based nanofluids.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901173h

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1691–1696

Titre :	Inverse gas chromatography investigation of rubber reinforcement by modified pyrolytic carbon black from scrap tires
Type de document :	texte imprimé
Auteurs :	Zhou, Jie, Auteur ; Yu, Tianming, Auteur ; Wu, Shengji, Auteur
Année de publication :	2010
Article en page(s) :	pp 1691–1696
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Gas chromatography Pyrolytic carbon.
Résumé :	Pyrolysis has the potential of transforming waste into recyclable products. Pyrolytic carbon black (PCB) is one of the most important products from the pyrolysis of used tires. Techniques for surface modifications of PCB have been developed. One of the most significant applications for modified PCB is to reinforce rubber matrixes to obtain high added values. Inverse gas chromatography (IGC) results show that a large quantity of inorganic materials and carbonaceous deposits are removed by treating pyrolytic carbon black with nitric acid solution. Plenty of active sites originally occupied by inorganic ash and coke are recovered. The surface energy of pyrolytic carbon black (TWPC) modified by titanate coupling agent, especially the specific interaction γssp determined by the specific probe molecule benzene, shows a strong interaction between the TWPC and the polyisoprene chains. Mechanical testing results confirmed the IGC prediction. The PCB modified by demineralization and NDZ-105 titanate coupling agent could be used to replace the commercial semireinforcing carbon black.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9009217

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1684–1690

Titre :	Thermally on−off switching membranes prepared by pore-filling poly(N-isopropylacrylamide) hydrogels
Type de document :	texte imprimé
Auteurs :	Wang, Wencai, Auteur ; Tian, Xiaodong, Auteur ; Yiping Feng, Auteur
Année de publication :	2010
Article en page(s) :	pp 1684–1690
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Polymer hydrogels Switching membranes.
Résumé :	Pore-filling N-isopropylacrylamide (NIPAAM) polymer hydrogels were successfully grafted onto track-etched polycarbonate (PC) membranes by plasma-induced graft copolymerization. The microstructure and morphology of the PC-g-PNIPAAM membranes were investigated by XPS, SEM, ATR-FTIR, TGA, and water flux experiments. The effective pore sizes were regulated by the volume change of the cross-linked PNIPAAM hydrogels in the temperature range around its lower critical solution temperature (LCST). The PC-g-PNIPAAM membranes demonstrated a fast and reversible valve switching mechanism in a small temperature range. The on−off water flux ratio became more significant with the increase of the monomer concentration. Contact angle results showed that the thermal-responsive gating characteristics of PC-g-PNIPAAM membranes were mainly dependent on the pore size change
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9008666

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1677–1683

Titre :	Synthesis of organoclays with controlled particle size and whiteness from chemically treated indian bentonite
Type de document :	texte imprimé
Auteurs :	Patel, Hasmukh A., Auteur ; Somani, Rajesh S., Auteur ; Hari C. Bajaj, Auteur
Année de publication :	2010
Article en page(s) :	pp 1677–1683
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Organoclays nanoclays Chemically treated bentonites.
Résumé :	Organoclays or nanoclays have gained increased attention from industry as well as academia during the past 11/2 decades. These clays are prepared from natural clays which invariably have other minerals as impurities. It is of prime significance to remove impurities from organoclays which find applications in polymer nanocomposites, paints, cosmetics, and medicinal formulations. The Indian bentonites were treated with sulfuric acid, hydrochloric acid, hydrogen peroxide, oxalic acid, citric acid, and sodium dithionite to remove impurities invariably present in natural clays. Treatment with both minerals and organic acid could remove both interlayer and structural iron and improve the whiteness with breaking up layered structure. However, sodium dithionite treatment is observed to be more suited to remove iron impurities from bentonite and improve whiteness to 11% without any effect on the structure of the clay. Chemically treated bentonites were used for preparing organoclays in a single step to eliminate the filtration and washing steps. The organoclays were prepared under varied reaction parameters such as temperature, the amount and type of organic modifier, and the concentration of the clay. The optimization of these parameters was done to prepare orgnaoclays with controlled particle size and whiteness.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie801368b

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1669–1676

Titre :	Hydrogenation of p-chloronitrobenzene on tungsten-modified NiCoB catalyst
Type de document :	texte imprimé
Auteurs :	Zhao, Bin, Auteur ; Chou, Chun-Jen, Auteur ; Chen, Yu-Wen, Auteur
Année de publication :	2010
Article en page(s) :	pp 1669–1676
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Hydrogenation Tungsten Catalyst.
Résumé :	NiCoB has been reported to be a good catalyst for the hydrogenation of p-chloronitrobenzene (p-CNB). However, it aggregates easily. In this study, a series of tungsten-modified NiCoB catalysts with various tungsten contents were synthesized by the chemical reduction method using NaBH4 as the reducing agent. The products were characterized by X-ray diffraction (XRD), N2 sorption, transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). The catalysts were tested for the liquid-phase hydrogenation of p-CNB. Ni, Co, W, and B were present in both elemental and oxidized states. The addition of tungsten could influence the surface composition of the catalyst. The electronic structures of Ni, Co, W, and B were also changed with changing content of tungsten. XPS showed that the elemental states of Ni, Co, W, and B formed an amorphous nanoalloy. The interactions of these species affected their electron densities and further influenced their catalytic activities. The tungsten oxide located among the NiCoB particles could act as a spacer that separates the NiCoB particles from their neighbors and inhibits aggregation. Compared to the unmodified NiCoB catalyst, the catalytic activity of tungsten-modified NiCoB exhibited an obvious increase, along with a slight decrease in the selectivity of p-chloroaniline (p-CAN). The differences in the atom radius and electronegativity of tungsten from those of the other elements in the alloy resulted in the formation of active sites for the catalytic reaction. The concentration of boron on the catalyst surface decreased with increasing tungsten concentration, which was responsible for the slight decrease in the selectivity of p-CAN. Considering the electronic effects, the structural effects, and the amount of B3+ (Lewis acid), good catalytic performance in the hydrogenation of p-CNB was achieved by modifying the NiCoB catalysts with the proper amount of tungsten. Tungsten species not only acted as a spacer to prevent NiCoB particles from aggregating, but also donated partial electrons to Ni and Co. An overdose of tungsten would cover the surface of Ni and result in low activity.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901606b

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1663–1668

Titre :	Influence of the support on MnOx metallic monoliths for the combustion of volatile organic compounds
Type de document :	texte imprimé
Auteurs :	Aguero, Fabiola N., Auteur ; Barbero, Bibiana P., Auteur ; Sanz, Oihane, Auteur
Année de publication :	2010
Article en page(s) :	pp 1663–1668
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	MnOx metallic Monoliths Organic compounds.
Résumé :	The influence of the alumina layer nature which acts as the support on the preparation of structured catalysts and on the catalytic performance in VOC combustion was studied. Anodized aluminum and a ferritic alloy covered with colloidal alumina (Nyacol) and θ−δ-Al2O3 were the materials used to prepare the monolith catalysts. The impregnation was performed in one and two stages using two different concentrations of manganese acetate solutions. The catalytic properties of these catalysts were evaluated in ethanol, ethyl acetate, and toluene combustion. The most active catalysts in the combustion of the three molecules were those prepared using a θ−δ-Al2O3 as a support. The low activity of aluminum monoliths anodized with H2SO4 is due to the presence of SO42− ions which act as catalyst poison. The anodization with H2C2O4 is a preferable method to prepare MnOx monolithic catalysts.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901567a

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1658–1662

Titre :	The Nature of PH3 decomposition reaction over amorphous CoNiBP alloy supported on carbon nanotubes
Type de document :	texte imprimé
Auteurs :	Lili Li, Auteur ; Han, Changxiu, Auteur ; Yang, Li, Auteur
Année de publication :	2010
Article en page(s) :	pp 1658–1662
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Carbon nanotube Amorphous CoNiBP.
Résumé :	The carbon nanotubes (CNTs) supported amorphous CoNiBP catalyst is synthesized by means of induced electroless-plating method. The morphology, structure, and composition of the catalyst are characterized using a number of analytical instrumentations including transmission electron microscopy, X-ray diffraction, BET surface area measurement, and inductively coupled plasma. The activity of the catalyst in phosphine decomposition reaction is measured and correlated with its surface and structural properties. The characterization results show that the amorphous CoNiBP alloy nanoparticles, having average diameters of about 5−9 nm and 8−12 nm, are uniformly distributed inside and on the surface of CNTs, respectively. During phosphine decomposition reaction, some of phosphorus atoms migrate onto the CoNiBP particles, forming crystalline CoP phase which acts as the dominant active phase for phosphine decomposition reaction. Furthermore, the CoNiBP/CNTs catalyst exhibits high activity and stability in phosphine decomposition reaction. When operated in a fixed-bed reactor at 380 °C, single-pass phosphine conversion of about 99.7% can be achieved.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9015478

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1652–1657

Titre :	Iron-ceria aerogels doped with palladium as water−gas shift catalysts for the production of hydrogen
Type de document :	texte imprimé
Auteurs :	Bali, Sumit, Auteur ; Huggins, Frank E., Auteur ; Ernst, Richard D., Auteur
Année de publication :	2010
Article en page(s) :	pp 1652–1657
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Iron oxide Cerium oxide catalys.
Résumé :	Mixed 4.5% iron oxide−95.5% cerium oxide aerogels doped with 1% and 2% palladium (Pd) by weight have been synthesized, and their activities for the catalysis of water−gas shift (WGS) reaction have been determined. The aerogels were synthesized using propylene oxide as the proton scavenger for the initiation of hydrolysis and polycondensation of a homogeneous alcoholic solution of cerium(III) chloride heptahydrate and iron(III) chloride hexahydrate precursor. Palladium was doped onto some of these materials by gas-phase incorporation (GPI) using (η3-allyl)(η5-cyclopentadienyl)palladium as the volatile Pd precursor. Water−gas shift catalytic activities were evaluated in a six-channel fixed-bed reactor at atmospheric pressure and reaction temperatures ranging from 150 to 350 °C. Both 1% and 2% Pd-doped 4.5% iron oxide−95.5% cerium oxide aerogels showed WGS activities that increased significantly from 150 to 350 °C. The activities of 1% Pd-doped 4.5% iron oxide−95.5% cerium oxide aerogels were also compared with that of the 1% Pd-doped ceria aerogel without iron. The WGS activity of 1% Pd on 4.5% iron oxide−95.5% cerium oxide aerogels is substantially higher (5 times) than the activity of 1% Pd-doped ceria aerogel without iron. The gas-phase incorporation results in a better Pd dispersion. Ceria aerogel provides a nonrigid structure wherein iron is not significantly incorporated inside the matrix, thereby resulting in better contact between the Fe and Pd and thus enhancing the WGS activity. Further, neither Fe nor Pd is reduced during the ceria-aerogel-catalyzed WGS reaction. This behavior contrasts with that noted for other Fe-based WGS catalysts, in which the original ferric oxide is typically reduced to a nonstoichiometric magnetite form.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901543w

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1642–1651

Titre :	Kinetic investigation of benzene ethylation with ethanol over USY zeolite in a riser simulator
Type de document :	texte imprimé
Auteurs :	Odedairo, T., Auteur ; Al-Khattaf, S., Auteur
Année de publication :	2010
Article en page(s) :	pp 1642–1651
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Kinetic Benzene Ethylation Zeolite.
Résumé :	The ethylation of benzene with ethanol over USY zeolite catalysts has been investigated at three different temperatures (300, 350, and 400 °C) for reaction times of 3, 5, 7, 10, 13, and 15 s with constant benzene to ethanol mole ratio of 1:1. Significant benzene conversion was found in the ethylation of benzene with ethanol over USY-2 catalyst as compared with the negligible conversion observed over USY-1 catalyst of lower acidity. The cracking of ethylbenzene (EB) was found to dominate at high temperatures (350 and 400 °C) in the ethylation of benzene with ethanol over USY-2 catalyst while ethylbenzene ethylation becomes significant at lower temperature (300 °C). Considerable amount of toluene was observed in the ethylation of benzene over USY-2 catalyst and was found to increase with increasing reaction temperature. The effect of reaction conditions on ethylbenzene selectivity, toluene selectivity, toluene-to-EB ratio, and total diethylbenzene (DEB) selectivity, are reported. Kinetic parameters for the ethylation of benzene with ethanol (E1), cracking of EB (E2), ethylation of ethylbenzene with ethanol (E3), and the cracking of diethylbenzene (E4) over USY-2 catalyst were determined using the catalyst activity decay function based on time-on-stream model. The apparent activation energies were found to decrease as follows: E2 > E3 > E4 > E1.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901526d

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1631–1641

Titre :	Effect of gas and liquid superficial velocities on the performance of monolithic reactors
Type de document :	texte imprimé
Auteurs :	Mogalicherla, Aswani Kumar, Auteur ; Deepak Kunzru, Auteur
Année de publication :	2010
Article en page(s) :	pp 1631–1641
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Gas Monolithic reactors.
Résumé :	The effect of gas and liquid velocities on the rate of hydrogenation of α-methyl styrene (AMS) in a monolithic reactor has been investigated at different washcoat loadings. The catalyst used was 0.5 wt% Pd/Al2O3. To cover a wide range of velocities, reaction studies were conducted in multichannel as well as single-channel monolith blocks. The liquid channel velocity was varied from 0.5 cm/s to 22 cm/s, and the gas channel velocity was varied from 1.2 cm/s to 22 cm/s. To study the effect of internal diffusional resistance, the washcoat thickness was varied from 11 μm to 62 μm. Under these operating conditions, both external mass-transfer and internal diffusional resistance affected the rate of reaction. At low liquid velocities (<2 cm/s), the measured rate of reaction was not significantly affected by the gas velocity, whereas at high liquid velocities, the measured reaction rate passed through a maximum with increasing gas velocity. The highest reaction rates were obtained for gas and liquid velocities in the range of 5−10 cm/s. At higher liquid velocities (>10 cm/s), the rate of reaction decreased with liquid velocity, most probably because of the increase in liquid slug length and film thickness around the gas bubble. The overall effectiveness factor of the monolith catalyst was determined from the measured rate of reaction and the published intrinsic kinetics. Using the approximation of Gottifredi et al. for nonlinear kinetics [Gottifredi et al. Chem. Eng. Sci. 1981, 36, 313−317], the internal effectiveness factor and overall mass-transfer coefficient were determined. The overall mass-transfer coefficients determined from the reaction-rate data have been compared with the values calculated using the available correlations.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901442d

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1625–1630

Titre :	Low-pressure catalytic wet air oxidation of aniline over Co3O4/CeO21
Type de document :	texte imprimé
Auteurs :	Ersoz, Gulin, Auteur ; Atalay, Suheyda, Auteur
Année de publication :	2010
Article en page(s) :	pp 1625–1630
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Catalytic Oxidation Electron microscope X-ray diffraction Thermogravimetric analysi.
Résumé :	Low -pressure catalytic wet air oxidation of aniline was investigated in a bubble reactor over Co3O4 (10% wt)/CeO2. The catalyst was prepared by sol−gel technology and characterized by using scanning electron microscope, X-ray diffraction, nitrogen adsorption, and thermogravimetric analysis techniques. The aim was to search for the conditions to destroy the aniline content by avoiding production of byproducts such as ammonium, nitrate, and nitrite ions. The reaction was optimized at 0.5 g/L catalyst loading at 150 °C with a pressure of 4 atm, in 2 h with an air flow rate of 1.36 L/min. A 35.15% amount of aniline was removed, and 14% of the input nitrogen was converted into N2 gas. To evaluate the stability of the catalyst, two consecutive runs were performed by reusing the catalyst recovered. The highest removal with the reused catalyst was found as 34.94%, showing that Co3O4/CeO2 is a stable catalyst.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901383e

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1611–1624

Titre :	Enhanced olefin production from renewable aliphatic feedstocks and co-fed lignin derivatives using experimental surrogates by millisecond catalytic partial oxidation
Type de document :	texte imprimé
Auteurs :	Dreyer, Bradon J., Auteur ; Dauenhauer, Paul J., Auteur ; Horn, Raimund, Auteur
Année de publication :	2010
Article en page(s) :	pp 1611–1624
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Olefin Lignin derivatives Catalytic Oxidation.
Résumé :	To investigate the effect of co-fed lignin derivatives on olefin production in the catalytic partial oxidation of aliphatic feedstocks, benzene was selected as a lignin surrogate and n-hexane was selected as a renewable oil surrogate. Aromatic benzene and aliphatic n-hexane, along with the corresponding 80:20 and 50:50 molar n-hexane/benzene mixtures, were partially oxidized in millisecond contact time reactors, varying the fuel to oxygen ratio (0.8 < C/O < 2.0), the catalyst (5 wt % Pt or Rh), the support (45 or 80 pores per linear inch α-Al2O3) while maintaining constant space time (GHSV=105 h−1). The experiments indicate that the addition of benzene likely results in competitive catalytic adsorption which reduces the catalytic oxidation of n-hexane and increases production of olefins by homogeneous cracking. Under optimal conditions, selectivity to ethylene and propylene from n-hexane was increased from 35% using pure n-hexane to 65% when using a 50:50 molar mixture of benzene and n-hexane. Results indicate that the addition of lignin-derived aromatic species should increase production of olefins from catalytically reformed renewable oils.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9013452

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1605–1610

Titre :	Mass transfer in a rotor−stator spinning disk reactor with cofeeding of gas and liquid
Type de document :	texte imprimé
Auteurs :	Meeuwse, Marco, Auteur ; John Van Der Schaaf, Auteur ; Schouten, Jaap C., Auteur
Année de publication :	2010
Article en page(s) :	pp 1605–1610
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Mass transfer Gas liquid.
Résumé :	This paper presents a new type of spinning disk reactor configuration for gas−liquid operations. It combines the features of a classical spinning disk with a liquid film on the rotor [e.g., Aoune, A.; Ramshaw, C. Int. J. Heat Mass Transfer 1999, 42, 2543−2556] and those of a rotor−stator spinning disk unit with a single gas inlet in the bottom stator [Meeuwse, M.; van der Schaaf, J.; Kuster, B. F. M.; Schouten, J. C. Chem. Eng. Sci. 2010, 65 (1), 466−471]. In this new configuration, gas and liquid are cofed through an inlet in the top stator. It is shown that gas−liquid mass transfer mainly takes place in the dispersed region between the rotor and the bottom stator. kGLaGLVR in this region is up to a factor of 6 larger than in the region with the liquid film on the rotor. Simulation of gas desorption from a saturated liquid shows that the gas−liquid mass transfer in this cofed configuration is considerably improved in comparison to the separate reactors, at similar operating conditions. The new reactor has also a higher potential for scaling up: gas and liquid can be cofed from one rotor−stator unit to another without the need for redistribution of the gas.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901301m

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1600–1604

Titre :	Article mechanism and kinetics of sulfonation of polystyrene−butadiene rubber with chlorosulfonic acid
Type de document :	texte imprimé
Auteurs :	Idibie, Christopher A., Auteur ; Abdulkareem, Saka A., Auteur ; Pienaar, Christo H. vZ, Auteur
Année de publication :	2010
Article en page(s) :	pp 1600–1604
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	kinetics Sulfonation Chlorosulfonic Acid.
Résumé :	The sulfonation kinetics of polystyrene−butadiene rubber (PSBR) with different initial concentrations of chlorosulfonic acid was studied. First, the kinetic study showed that an optimum sulfonation time of 24 h and 1.6 M/mL of chlorosulfonic acid were required for the sulfonation of PSBR to obtain optimum degree of sulfonation. First-order irreversible and first-order reversible models for the reaction kinetics were investigated. The reaction rate was found to obey the first-order reversible model in aromatic ring content due to the effect of HCl produced alongside with the sulfonated rubber. A predictive model was developed, which is able to predict the degree of sulfonation at different initial concentrations of the acid. The simulated results were found to correspond properly with the experimental result with correlation coefficients between 0.991 and 0.997 depending on the concentration of the acid.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9012858

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1591–1599

Titre :	Thermogravimetric analysis of tobacco combustion assuming DAEM devolatilization and empirical char-burnoff kinetics
Type de document :	texte imprimé
Auteurs :	Varhegyi, Gabor, Auteur ; Czégény, Zsuzsanna, Auteur ; Liu, Chuan, Auteur
Année de publication :	2010
Article en page(s) :	pp 1591–1599
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Thermogravimetric analysis kinetics.
Résumé :	Two blends of tobacco (Virginia and Burley) were studied by thermogravimetry at linear and nonlinear heating programs in gas flows containing 2, 4, and 9% oxygen. A kinetic scheme of successive devolatilization and char-burnoff reactions was assumed. A distributed activation energy model was assumed for devolatilization with a Gaussian distribution and a constant preexponential factor. The evaluations were also carried out using nonconstant preexponential factors that depended on the activation energy. The char burnoff was described by first-order kinetics and by an empirical model that took into account the change of the reactivity with conversion of the sample. The dependence of the rate of combustion on the oxygen concentration was approximated by a power function. Series of 15 and 30 experiments were used for the determination of the model parameters by simultaneous least-squares evaluation of the experiments. The considerations, methods, and results can also be used in the fields of biomass gasification and combustion.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901180d

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1588–1590

Titre :	Kinetics of the acid digestion of serpentine with concurrent grinding. 3. model validation and prediction
Type de document :	texte imprimé
Auteurs :	Van Essendelft, Dirk T., Auteur ; Schobert, Harold H., Auteur
Année de publication :	2010
Article en page(s) :	pp 1588–1590
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Kinetics Magnesium Serpentine
Résumé :	The rapid extraction of magnesium from serpentine is critical to novel low-pressure mineral carbonation methodology. Although almost any acid can dissolve the magnesium, the rate plays a critical role in the industrialization of the process. As detailed in parts 1 and 2 of this study [Van Essendelft and Schobert Ind. Eng. Chem. Res. 2009, 48 (5), 2556−2565; 2009, 48 (22), 9892−9901], a computational model has been developed that explains the kinetics of the extraction of magnesium from serpentine with concurrent grinding. The model has direct ties to first principles and accounts for surface speciation and reaction, the electrical double layer, ash-layer diffusion, particle size distribution, temperature effects, and solution thermodynamics. It is desirable to demonstrate the robustness of the model and to use the model to predict useful scenarios. Presented here are experimental data obtained under various conditions not tested before and the predictions of the model under those circumstances, as well as the predictions of the model in an industrial application.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901159t

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1577–1587

Titre :	Experimental investigation of a JP8 fuel processor : autothermal reformer and CO-cleanup train
Type de document :	texte imprimé
Auteurs :	Barrai, Federico, Auteur ; Marco J. Castaldi, Auteur
Année de publication :	2010
Article en page(s) :	pp 1577–1587
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Fuel processor Autothermal CO-cleanup train.
Résumé :	This paper presents an experimental investigation of a fuel processor consisting of a JP-8 autothermal reforming (ATR) reactor and a surrogate-fed CO-cleanup train. The CO-cleanup train, comprising a water−gas shift (WGS) and two preferential oxidation (PROX) reactors, was tested as an integrated reactor train. A finned-wall ATR reactor was examined for light-off behavior and for steady-state product distribution, upon which the CO-cleanup train was designed. The thermal and chemical transient analysis during catalyst ignition indicated that the fuel undergoes deep oxidation to CO2 and H2O until 80% of the catalyst bed is ignited, followed by a significant rise in synthesis gas production. The WGS and PROX reactors were tested individually with the objective of identifying operating regimes for maximum CO removal. The PROX reactor train, consisting of two identical reactors connected in series, reduced the CO concentration from 1% to less than 6 ppm. The PROX-1 and PROX-2 reactors were compared in order to elucidate the CO conversion and selectivity loss observed for PROX-1 at T > 250 °C and for PROX-2 at temperatures between 120 and 145 °C, suggesting that the CO conversion decrease follows different controlling mechanisms for the two reactors. Finally the CO-cleanup train was tested as three reactors in series, illustrating the critical effect that the CO conversion in the water−gas shift reactor has on the downstream PROX reactors. The CO-cleanup train was operated at the maximum conversion, demonstrating the capability to decrease the CO concentration from 8% to single-digit ppm level.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901735x

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1561–1576

Titre :	Numerical investigation of sorption enhanced steam methane reforming process using computational fluid dynamics eulerian−eulerian code
Type de document :	texte imprimé
Auteurs :	Di Carlo, A., Auteur ; Bocci, E., Auteur ; Zuccari, F., Auteur
Année de publication :	2010
Article en page(s) :	pp 1561–1576
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Sorption Methane Computational fluid dynamics.
Résumé :	This paper highlights the use of a fluidized bed reactor of 10 cm i.d. for producing hydrogen by sorption-enhanced steam methane reforming (SE-SMR). The model used for the hydrodynamic behavior of the bed is Eulerian−Eulerian. The kinetics of the steam methane reforming, water−gas shift, and carbonation reactions are based on literature values. Intra- and extraparticle mass transfer effects are considered together with the kinetics in the chemical models. The bed is composed of an Ni catalyst and calcined dolomite. A static bed height of 20 cm is investigated. A volume ratio of dolomite/catalyst is varied from 0−5 during the simulation. Dry hydrogen mole fraction of >0.93 is predicted for temperatures of 900 K and a superficial gas velocity of 0.3 m/s with a dolomite/catalyst ratio >2. Furthermore, the bubble formation in the fluidized bed influence product yields and product oscillations are observed. Another important aspect is that when the dolomite/catalyst ratio is higher than 2 the necessary heat for the reforming endothermic reaction can be almost entirely supplied by the exothermic reaction of carbonation.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900748t

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1550–1560

Titre :	Catalysis and mechanistic studies of Ru(III), Os(VIII), Pd(II), and Pt(IV) metal ions on oxidative conversion of folic acid
Type de document :	texte imprimé
Auteurs :	Kumar, C. H. Vinod, Auteur ; Jagadeesh, R. V., Auteur ; Shivananda, K. N., Auteur
Année de publication :	2010
Article en page(s) :	pp 1550–1560
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Homogeneous catalysis Metal Ions Folic Acid.
Résumé :	The homogeneous catalysis of Ru(III), Os(VIII), Pd(II), and Pt(IV) in the oxidative conversion of folic acid (FA) to pterin-6-carboxylic acid, p-aminobenzoic acid, and glutamic acid by sodium N-bromo-p-toluenesulfonamide (bromamine-T; BAT) was studied in alkaline medium. The detailed kinetic and mechanistic investigations of all four catalyzed oxidation reactions were studied at 313 K. The stoichiometries and oxidation products of the four catalyzed reactions were found to be the same, but their kinetic patterns and oxidation mechanisms were different. The reactions were studied at different temperatures, and the activation parameters were evaluated for each catalyzed reaction. Under identical sets of experimental conditions, the kinetics of all four catalyzed reactions were compared with those of uncatalyzed reactions, revealing that the catalyzed reactions are 6−22 times faster. The catalytic efficiency of these catalysts follows the order Os(VIII) > Ru(III) > Pt(IV) > Pd(II). This trend can be attributed to the different d electronic configuration of the catalysts. Based on the observed experimental results, a detailed mechanistic interpretation and the related kinetic model were derived for each catalyst.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900340k

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1541–1549

Titre :	Screening of additives to a Co/SrCO3 catalyst by artificial neural network for preferential oxidation of CO in excess H2
Type de document :	texte imprimé
Auteurs :	Kobayashi, Yasukazu, Auteur ; Kohji Omata, Auteur ; Yamada, Muneyoshi, Auteur
Année de publication :	2010
Article en page(s) :	pp 1541–1549
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Catalysts Co/SrCO3 Cobalt carbonate.
Résumé :	Preferential oxidation (PROX) of CO in excess hydrogen was investigated over cobalt catalysts supported on SrCO3, which showed a high performance. From the results of X-ray diffraction, X-ray photoelectron spectra (XPS), and temperature-programmed desorption, it was concluded that the active species for the PROX of CO is not cobalt oxide but cobalt carbonate-like compound, which was formed in the catalyst preparation step from Co(NO3)2 precursor and SrCO3 support. On the basis of the multivariate analysis, characters by XPS analysis are the main factors to determine the CO conversion with Co/SrCO3 catalyst. The selectivity for CO oxidation was suppressed by the side reactions, such as H2 oxidation and reverse water-gas shift reaction. Therefore, new additive to the Co/SrCO3 catalyst for the retardation of the side reactions was investigated by using an artificial neural network (ANN). The activities of 17 mol % Co + 1.7 mol % X/SrCO3 (X = B, K, Sc, Mn, Zn, Nb, Ag, Nd, Re and Tl) and 16 physicochemical properties of those 10 elements were used as training data of ANN, and the most optimal additive among 53 elements in periodic table was predicted by ANN. From the result of the prediction and experimental verification, boron addition to the catalyst was effective to increase the activity for CO oxidation at the reaction temperature range from 200 to 240 °C. Actually, 17 mol % Co + 5.1 mol % B/SrCO3 catalyst showed 99% CO conversion with 52% selectivity at 200 °C with a feed composition of 0.69 vol % CO, 0.69 vol % O2, 4.5 vol % N2, 10 vol % H2 O, 17 vol % CO2 and H2 as a balance at a space velocity of 3 g·h/mol, and its activity was stable for 50 h.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901435h

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1534–1540

Titre :	Removal of reactive blue 221 by kaolinite from aqueous solutions
Type de document :	texte imprimé
Auteurs :	Karaoglu, M. Hamdi, Auteur ; Dogan, Mehmet, Auteur ; Alkan, Mahir, Auteur
Année de publication :	2010
Article en page(s) :	pp 1534–1540
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Adsorption Reactive blue Aqueous Solutions.
Résumé :	The adsorption behavior of reactive blue 221 (RB221) on kaolinite was investigated by batch tests. The experiments were performed by employing a spectrophotometer to measure the concentration of RB221 before and after adsorption. The effects of various parameters such as initial solution pH, ionic strength, temperature, and acid activation were determined. The adsorption process reached equilibrium within 3 h. The adsorbed amount of RB221 increased with increasing ionic strength, temperature, and acid activation, but it decreased with increasing pH. Langmuir and Freundlich isotherms were applied to fit the equilibrium data to identify the best isotherm to describe the RB221 adsorption. The data were best described by the Langmuir isotherm. The isosteric heat of adsorption indicated the endothermic nature of RB221 adsorption on kaolinite. It was concluded that reactive blue 221 physically adsorbs on kaolinite. The value of the dimensionless separation factor (RL) suggests that kaolinite can be used for the removal of reactive blue 221 from aqueous solutions. The experimental results were applied to a batch design. As a result, kaolinite could be used for the removal of dyes from aqueous solutions.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9017258

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1530–1533

Titre :	Investigation on the Oxidation Mechanism of Cobalt Hydroxide to Cobalt Oxyhydroxide
Type de document :	texte imprimé
Auteurs :	Ramesh, Thimmasandra Narayan, Auteur
Année de publication :	2010
Article en page(s) :	pp 1530–1533
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Oxidation mechanism Hydroxide Cobalt oxyhydroxide.
Résumé :	Cobalt hydroxide and cobalt oxyhydroxide derive their crystal structure from brucite mineral. Cobalt hydroxide crystallizes in hexagonal 1H polytype while cobalt oxyhydroxide in rhombohedral symmetry. In spite of the isostructural relationship between cobalt hydroxide and oxyhydroxide, we observe different symmetries. Hexagonal and rhombohedral polytypes are related to each other by a simple translation vector. Translation of AC layers by (1/3, 2/3, 1) and (2/3, 1/3, 1) with respect to each other generates the 3R polytype. Careful evaluation of the X-ray powder diffraction (PXRD) patterns of cobalt oxyhydroxide reveals the exact stacking sequence to be AC CB BA. The structural transformation of cobalt hydroxide to cobalt oxyhydroxide is reported.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901714v

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1526–1529

Titre :	Oxypropylation of rapeseed cake Residue generated in the biodiesel production process
Type de document :	texte imprimé
Auteurs :	Serrano, Luis, Auteur ; Alriols, Maria Gonzalez, Auteur ; Briones, Rodrigo, Auteur
Année de publication :	2010
Article en page(s) :	pp 1526–1529
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Oxypropylation Biodiesel Propylene oxide.
Résumé :	he oxypropylation of rapeseed cake residue generated in the biodiesel production process was studied. The reaction was carried out by suspending the rapeseed cake residue in propylene oxide [30/70 ratio (w/v)] in the presence of a basic catalyst (10% KOH) and heating the resulting mixture at 160 °C in a nitrogen atmosphere. The chemical structure of the obtained polyol was studied by CHNS elemental analysis, infrared spectroscopy, and 1H NMR spectroscopy, and other parameters such as viscosity, OH number, molecular weight (GPC), and thermal behavior (DSC, TGA) were also measured. The obtained results showed an almost total conversion of the solid substrate into a polyol with good characteristics (OH number, 610 mg of KOH/g; viscosity, 84.23 Pa·s; and molecular weight, 33550 g/mol) for use in polyurethane, polyether, or polyester formulations.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9016732

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1520–1525

Titre :	Hydrothermal electrolysis of glycerol using a continuous flow reactor
Type de document :	texte imprimé
Auteurs :	Yuksel, Asli, Auteur ; Koga, Hiromichi, Auteur ; Sasaki, Mitsuru, Auteur
Année de publication :	2010
Article en page(s) :	pp 1520–1525
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Hydrothermal electrolysis Glycerol Continuous flow reactor.
Résumé :	Hydrothermal electrolysis reactions of glycerol were investigated under various operating conditions to determine the effects of applied DC current, electrolysis time, and alkali concentration on the decomposition mechanism of glycerol. In addition, intermediate products were identified, possible reaction schemes for both hydrothermal electrolysis and hydrothermal degradation of glycerol based on experimental data were clarified, and detailed product analysis was conducted using high performance liquid chromatography (HPLC), gas chromatography with a flame ionization detector (GC-FID), and gas chromatography with a thermal conductivity detector (GC-TCD). For the present study, a continuous flow reactor equipped with titanium electrodes (as cathode and anode), an electric furnace, a heater, a pump, a heat exchanger, a back pressure regulator, and DC supply was used. The main gaseous product was hydrogen, whereas glycolaldehyde, lactic acid, and formic acid were the main liquid products. Results indicate that greater than 92% of the glycerol could be decomposed under optimum conditions by hydrothermal electrolysis using the continuous
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9016418

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1514–1519

Titre :	Nafion−montmorillonite nanocomposite membrane for the effective reduction of fuel crossover
Type de document :	texte imprimé
Auteurs :	Felice, Christine, Auteur ; Ye, Stanley, Auteur ; Qu, Deyang, Auteur
Année de publication :	2010
Article en page(s) :	pp 1514–1519
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Nanocomposite membranes Methanol Hydrogen migration.
Résumé :	The effect of Nafion−clay nanocomposite membranes on hydrogen and methanol crossover in a proton exchange membrane (PEM) fuel cell was studied. Several analytical methods were used to determine the fuel crossover rate and the ionic conductivity of the membranes. It is the first time a Nafion−clay nanocomposite was investigated to reduce the hydrogen migration rate across the PEM membrane. The Nafion−clay nanocomposites demonstrated significantly reduced permeability to both methanol and hydrogen. The reduction of hydrogen and methanol crossover was compared, and the possible mechanistic difference was discussed. The ionic conductivities for both in-plane and through-plane were measured using alternating current impedance techniques. The ionic conductivities of the Nafion−clay nanocomposites were lower than a pure Nafion membrane of the same thickness.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901600a

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1503–1513

Titre :	Poly(vinyl chloride)/kaolinite nanocomposites : characterization and thermal and optical properties
Type de document :	texte imprimé
Auteurs :	Turhan, Yasemin, Auteur ; Dogan, Mehmet, Auteur ; Alkan, Mahir, Auteur
Année de publication :	2010
Article en page(s) :	pp 1503–1513
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Nanocomposites Kaolinite X-ray diffraction Thermal Optical Properties.
Résumé :	Nanocomposites of poly(vinyl chloride) (PVC) have been prepared by solution intercalation method using both natural and modified kaolinites. Kaolinite was modified with dimethyl sulfoxide (DMSO) to expand the interlayer basal spacing. The characterization of PVC/kaolinite nanocomposites was made by X-ray diffraction (XRD) and transmission electron microscopy (TEM); the interactions between kaolinite and PVC was discussed by FTIR-ATR; the thermal stability was determined by simultaneous DTA/TG. FTIR-ATR confirms hydrogen bonds formed between dimethyl sulfoxide molecules and the inner surface hydroxyl groups of kaolinite. XRD and TEM results give evidence that kaolinite was dramatically intercalated into nanoscale and homogenously dispersed in the PVC matrix. Thermogravimetric analysis indicated that introduction of clay to the polymer network resulted in an increase in thermal stability. Ultraviolet (UV) absorbance experiments showed that nanocomposites have a higher UV transmission than PVC film. The Kissinger method was used for calculation the decomposition activation energy. The results have shown that activation energy values at both stages for PVC/kaolinite nanocomposite are higher than those of pure PVC, indicating that addition of kaolinite particles improves thermal stability of PVC.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901384x

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1493–1502

Titre :	Studies of collector adsorption on iron oxides by in situ ATR-FTIR spectroscopy
Type de document :	texte imprimé
Auteurs :	Potapova, E., Auteur ; Carabante, I., Auteur ; Grahn, M., Auteur
Année de publication :	2010
Article en page(s) :	pp 1493–1502
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Adsorption Iron Oxides Spectroscopy.
Résumé :	In this work, the adsorption of three model collectors, viz., poly(ethylene glycol) monooleate (PEGMO), ethyl oleate, and maleic acid, as well as the commercial fatty-acid-type collector Atrac 1563, was studied in situ on synthetic hematite using attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy. The adsorption behavior of the studied compounds on hematite was determined to a large extent by the polar headgroup. Adsorption of Atrac and PEGMO as a function of concentration showed good agreement with the Freundlich adsorption model, suggesting energetically heterogeneous adsorption. In situ desorption experiments revealed that a large fraction of the Atrac was weakly attached to the hematite surface, as it was partially removed by flushing with water at pH 8.5 and 10. These results suggest that a separate washing unit after the flotation step could be beneficial in reducing the contamination of iron ore by flotation chemicals.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901343f

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1486–1492

Titre :	Inhibition of methane hydrate formation by ice-structuring proteins
Type de document :	texte imprimé
Auteurs :	Jensen, Lars, Auteur ; Ramlov, Hans, Auteur ; Kaj Thomsen, Auteur
Année de publication :	2010
Article en page(s) :	pp 1486–1492
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Methane hydrate Ice structuring proteins.
Résumé :	In the oil and gas industry there is ample motivation for moving toward greener kinetic inhibitors of gas hydrates as many of those used today suffer from poor biodegradability. In this work, we have investigated experimentally whether ice-structuring proteins (ISPs) found in fish and insect, assumed biodegradable, are capable of inhibiting the growth of methane hydrate (a structure I hydrate). The ISPs investigated were type III HPLC12 (originally identified in ocean pout) and ISP type III found in meal worm (Tenebrio molitor). These were compared to polyvinylpyrrolidone (PVP) a well-known kinetic hydrate inhibitor. The results revealed that adding ISP in sufficient amounts caused the appearance of an initial nonlinear growth period. At a certain point during the growth process the growth pattern changed to linear which is identical to the growth observed for methane hydrate in the absence of inhibitors. The profile of the nonlinear growth was concentration-dependent but also dependent on the stirring rate. ISP type III HPLC12 decreased the growth rate of methane hydrate during the linear growth period by 17−75% at concentrations of 0.01−0.1 wt % (0.014−0.14 mM) while ISP from Tenebrio molitor and PVP decreased the growth rate by 30% and 39% at concentrations of 0.004 wt % (0.005 mM) and 0.1 wt % (0.1 mM), respectively. Considering the low concentration of Tenebrio molitor ISP used, these results indicate that ISP from Tenebrio molitor is the most effective hydrate inhibitor among those investigated. Thermal hysteresis ice formation experiments revealed that ISP from Tenebrio molitor causes higher thermal hysteresis for ice formation compared to type III ISP identified in ocean pout while PVP did not cause thermal hysteresis. This indicates that there might be a direct relationship between ISP performance for ice and hydrate inhibition, and that thermal hysteresis experiments can be used to screen ISPs as kinetic inhibitors.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901321p

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1480–1485

Titre :	Synthesis, characterization, and photocatalytic activity of Sr2+ doped TiO2 nanoplates
Type de document :	texte imprimé
Auteurs :	Kumaresan, L., Auteur ; Mahalakshmi, M., Auteur ; Palanichamy, M., Auteur
Année de publication :	2010
Article en page(s) :	pp 1480–1485
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Photocatalytic nanoplates Strontium.
Résumé :	Strontium doped titania (TiO2) nanoplates and titania nanoparticles were synthesized by sol−gel method. The characterization of the materials revealed the mesoporous nanoplate-like structure for Sr2+ doped TiO2. The thickness and edge length of Sr2+ doped TiO2 nanoplates were found to be 12 nm and 25−75 nm, respectively. TiO2 nanoparticles and Sr2+ doped TiO2 nanoplates showed higher surface area due to the presence of mesopores. The photocatalytic activity of TiO2 nanoparticles and Sr2+ doped TiO2 nanoplates was evaluated using 2,4-dinitrophenol (DNP) as a model pollutant. The photocatalytic activity of Sr2+ doped TiO2 nanoplates was higher than both TiO2 nanoparticles and commercial TiO2 (Degussa P-25). Sr2+ doped TiO2 nanoplates exhibited enhanced photocatalytic activity due to increases in the band gap energy and surface area.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901191z

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1473–1479

Titre :	Peroxide−acetic acid pretreatment to remove bagasse lignin prior to enzymatic hydrolysis
Type de document :	texte imprimé
Auteurs :	Tan, He, Auteur ; Yang, Rallming, Auteur ; Sun, Weidong, Auteur
Année de publication :	2010
Article en page(s) :	pp 1473–1479
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Peroxide-acetic acid Enzymatic hydrolysis.
Résumé :	This paper presents results on the features of bagasse pretreatment with peroxide and acetic acid (peroxide−HAc) aiming at selective removal of lignin to enhance enzymatic hydrolysis. Surface response methodology was employed to study the effects of major process parameters on delignification and to establish a model for the prediction of lignin removal in the process. Enzymatic hydrolysis following the pretreatment was conducted to evaluate the enhancement of biohydrolysis by the pretreatment. Results revealed that peroxide−HAc pretreatment of bagasse retained most of the carbohydrate constituents, although the delignification rate was low. Peroxide−HAc concentration, temperature, and time demonstrated significant effects on bagasse lignin removal. The relationship between lignin removal and the process parameters could be well described by a mathematical model derived from the experimental data. After treatment with 69.1% peroxide−HAc at 80 °C for 26.5 h, 97.08% of lignin could be removed while keeping 68.24% hemicelluloses intact. Over 93.58% of carbohydrate in treated bagasse could be hydrolyzed with exoglucanase in a dosage of 138 FPU/g carbohydrates at 35 °C within 48 h. It was thus demonstrated that treated bagasse has a much higher response toward enzymatic hydrolysis than its untreated counterpart.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901529q

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1467–1472

Titre :	Effect of ethanol organosolv pretreatment on enzymatic hydrolysis of buddleja davidii stem biomass
Type de document :	texte imprimé
Auteurs :	Hallac, Bassem B., Auteur ; Sannigrahi, Poulomi, Auteur ; Pu, Yunqiao, Auteur
Année de publication :	2010
Article en page(s) :	pp 1467–1472
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Ethanol organosolv pretreatment Enzymatic Biomass.
Résumé :	Ethanol organosolv pretreatment was performed on Buddleja davidii to evaluate this bioresource as a potential feedstock for bioethanol production. B. davidii was pretreated and delignified, while 85% of the glucose content of the untreated material was retained in the pretreated solid fraction. The enzymatic hydrolysis showed that organosolv pretreatment produced solid substrates that were readily digestible by cellulases. Gel-permeation chromatography was used to determine the degree of polymerization (DP) of cellulose, and solid-state cross polarization/magic angle spinning 13C NMR experiments were conducted to study the changes in crystallinity and ultrastructure of cellulose. The results showed a decrease in DP along with an increase in the relative proportions of para-crystalline and amorphous cellulose and a decrease in cellulose Iα and Iβ. Removal of lignin and hemicellulose, reduction in DP, and decrease in the crystalline allomorphs (Iα and Iβ) increased the amenability of the biomass to enzymatic degradation.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900683q

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 4 (Fevrier 2010) . - pp 1457–1466

Titre :	Review: the use of microwave irradiation in the processing of glasses and their composites
Type de document :	texte imprimé
Auteurs :	Oxana V. Kharissova, Auteur ; Boris I. Kharisov, Auteur ; Ruz Valdés, Juan Jacobo, Auteur
Année de publication :	2010
Article en page(s) :	pp 1457–1466
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Radiation Thermal treatment Glass precursors.
Résumé :	The use of microwave (MW) radiation in glass processing is reviewed and compared to the usual processing techniques, such as glass melting, sintering, sealing, devitrification, coating, reinforcement with various substances, deposition by layers, etc. MW heating is known as a much-faster process (requiring minutes rather than hours), yielding good product quality, in comparison with the prolonged conventional thermal treatment of glass precursors.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9014765

Industrial & engineering chemistry research / Paul, Donald R. . Vol. 49 N° 4

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