Catalogue en ligne Bibliothèque Ecole Nationale Polytechnique d'Alger

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 14221–14225

Titre :	Development of a simple method to predict boiling points and flash points of acyclic alkenes
Type de document :	texte imprimé
Auteurs :	Felix A. Carroll, Auteur ; Justin M. Godinho, Auteur ; Frank H. Quina, Auteur
Année de publication :	2012
Article en page(s) :	pp. 14221–14225
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Boiling point
Résumé :	Boiling points (TB) of acyclic alkenes are predicted from their boiling point numbers (YBP)witfa the relationship TB(K) = ―16.802YBP2/3 + 337.377YBP1/3― 437.883. In turn, YBP values are calculated from structure using the relationship YBF = Oi + 1.726 + 2.779C + 1.716M3 + 1.564M + 4.204E3 + 3.905E ― 0.329D + 0.241G + 0.479V+ 0.967T+ 0.574S. Here Oi is a parameter that depends on the substitution pattern of the alkene, while the rest of the equation is the same as that reported earlier for calculating the YBP values of alkanes. For a data set consisting of 250 acyclic alkenes having from 6 to 36 carbon atoms, the average absolute deviation between literature TB values and those predicted with these equations was 1.29 K, and the R2 of the correlation was 0.999. In addition, the calculation of boiling points by this method provides a useful means to predict the flash points of alkenes from structure.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299894

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 14217-14220

Titre :	Optimization of galactoglucomannans and acidic arabinans recovery in softwood
Type de document :	texte imprimé
Auteurs :	Lyne Desharnais, Auteur ; Fang Du, Auteur ; Nicolas Brosse, Auteur
Année de publication :	2012
Article en page(s) :	pp. 14217-14220
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Softwood Optimization
Résumé :	Autohydrolysis of softwood chips, used as raw material in a paper mill, was studied to simulate one of the aspects of industrial hydrolytic steps of a thermomechanical pulping process. The compositions of the pulps and of the hydrolysates were determined as a function of the residence time and the severity of the treatment. It was found that acidic arabinogalactans were largely affected and depolymerized, even at low severity (log(R0) < 2). The percentage of residual arabinans in the pulp after hydrolysis seemed be a good indicator of the severity of the treatment and can provide an effective guide for an optimization of the industrial process. A hydrolytic step performed at a severity oflog(R0) = 1.8 resulted in the extraction of∼ 100% of the water-soluble acidic arabinogalactans, which constitutes the main part of the αanionic trash" released in mechanical pulping.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299893

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011)

Titre :	Reduction of 4 - chlorophenol by Mg and Mg – Ag bimetallic nanocatalysts
Type de document :	texte imprimé
Auteurs :	Jignasa N. Solanki, Auteur ; Zagabathuni Venkata, Auteur ; Panchakshari Murthy, Auteur
Année de publication :	2012
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Chlorophenol Nanocatalysts
Résumé :	Mg nanocatalyst is successfully synthesized in the present study using wet chemical method via the chemical reduction of magnesium sulfate and a reducing agent (sodium borohydride). Size/size distribution characterization is performed by dynamic light scattering (DLS) and scanning electron microscopy (SEM). Subsequently, 4-chlorophenol compound reduction is systematically studied with Mg catalyst. An ultraviolet―visible light (UV―vis) spectrophotometer is used to study the absorption spectra of in situ reduction reaction with time. Gradual disappearance of the peak corresponding to chloro compounds reveals the degradation of chloro compounds with time. Furthermore, the appearance of a new peak reveals the formation of a respective product (phenol). Mg―Ag bimetallic nanocatalyst is also synthesized via an equivalent chemical method and analogous reduction is performed with the catalyst. The performance of the Mg―Ag bimetallic catalyst is compared with that of the Mg nanocatalyst. Superior dechlorination percentage is observed with the Mg―Ag bimetallic nanocatalyst.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie2022338

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 14203–14210

Titre :	Poly (allylamine) – mesoporous silica composite materials for CO2 capture from simulated flue gas or ambient air
Type de document :	texte imprimé
Auteurs :	Watcharop Chaikittisilp, Auteur ; Ratayakorn Khunsupat, Auteur ; Thomas T. Chen, Auteur
Année de publication :	2012
Article en page(s) :	pp. 14203–14210
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Mesoporous silica Composite materials
Résumé :	Low-molecular-weight poly(allylamine) is prepared via free-radical polymerization, and the resulting polymer is impregnated into mesocellular silica foams at different amine loadings. The resulting poly(allylamine)–silica composites are demonstrated as effective adsorbents for the extraction of carbon dioxide from dilute (simulated flue gas) and ultradilute (simulated ambient air) gas streams. The composite adsorbents are shown to have comparable adsorption capacities to more-conventional poly(ethyleneimine)–silica adsorbents. Potential advantages of poly(allylamine)-derived adsorbents are discussed.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201584t

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 14193–14202

Titre :	Simultaneous prediction of densities and vapor – liquid equilibria of mixtures containing an isomeric chlorobutane and methyl tert - butyl ether using the VTPR model
Type de document :	texte imprimé
Auteurs :	Diego Montaño, Auteur ; Ignacio Gascón, Auteur ; Bastian Schmid, Auteur
Année de publication :	2012
Article en page(s) :	pp. 14193–14202
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Vapor Liquid Isomeric Chlorobutane
Résumé :	Densities of four binary mixtures formed by an isomer of chlorobutane (1-chlorobutane, 2-chlorobutane, 1-chloro-2-methylpropane, or 2-chloro-2-methylpropane) and methyl tert-butyl ether have been measured in the temperature range 283.15 K–313.15 K; from these densities the corresponding excess volumes have been obtained and correlated. The isothermal vapor–liquid equilibria have been also studied at T = 288.15, 298.15, and 308.15 K, and the experimental data have been satisfactorily checked for thermodynamic consistency using the method of Van Ness. The isothermal vapor–liquid equilibria data have been correlated using the Wilson equation, and excess Gibbs energies have been calculated. We have employed this experimental information to check the reliability of the predicted densities and vapor–liquid equilibria of the volume translated Peng–Robinson group contribution equation of state (VTPR model) by comparing the experimental results with the corresponding predictions. The predictions of both properties can be considered as satisfactory.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202082g

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 14186-14192

Titre :	Rheological percolation behavior and isothermal crystallization of poly(butyene Succinte)/carbon nanotube composites
Type de document :	texte imprimé
Auteurs :	Lijuan Yuan, Auteur ; Defeng Wu, Auteur ; Ming Zhang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 14186-14192
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Composite material Crystallization
Résumé :	Carbon nanotube (CNT) filled poly(butylene succinate) composites (PBSCNs) were prepared by melt compounding. The oscillatory rheological properties and crystallization behavior and kinetics were then investigated. The results show that the percolation network of CNTs in the small amplitude oscillatory shear flow is temperature dependent and the values of percolation thresholds reduce gradually with an increase of temperature. Therefore, the principle of time-temperature superposition is invalid on the dynamic rheological responses of those percolated PBSCNs. Besides, the presence of CNTs highly promotes the crystallization of PBS, increasing the overall crystallization rate. But the nucleation mechanism of PBS is not altered with addition of CNTs because the PBS itself is nucleated heterogeneously.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299889

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 14175-1418

Titre :	Implementation of SAFT + Cubic, PC - SAFT, and soave – benedict – webb – rubin equations of state for comprehensive description of thermodynamic properties in binary and ternary mixtures of CH4, CO2, and n - C16H34
Type de document :	texte imprimé
Auteurs :	Ilya Polishuk, Auteur
Année de publication :	2012
Article en page(s) :	pp. 14175-1418
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Carbon dioxide Ternary mixture Thermodynamic properties Equations of state
Résumé :	The binary and ternary mixtures considered in the present study are the most asymmetric ones for which the sound velocity and compressibility data are currently available, and their complete description, including auxiliary and phase equilibria properties, puts a challenging test for Equation of State (EoS) models. The recently proposed SAFT + Cubic EoS passes this test relatively successfully (AAD% for the single phase properties less than 6%), proving its robustness as a predictive tool. PC-SAFT appears to be the less reliable estimator of the data, whose AAD% might exceed 22%. Although the overall precision of the Soave—Benedict—Webb—Rubin (SBWR) model in predicting thermodynamic properties is better than of many popular EoS, it is not as advantageous as SAFT + Cubic (AAD% for the single phase properties less than 12%). The major difficulty of SBWR is modeling phase equilibria in asymmetric systems due to the prediction of the unrealistic U-type LLE critical loci. Nevertheless, the significant practical potential of SBWR for industrial applications should not be neglected, and this model deserves therefore further evaluation and development.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299888

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 14168-14174

Titre :	Experimental studies on phase transformation during pyrite concentrate oxidation under circulating fluidized bed (CFB) roasting conditions
Type de document :	texte imprimé
Auteurs :	Tao Wang, Auteur ; Hai Zhang, Auteur ; Qing Liu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 14168-14174
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Circulating fluidized bed Fluidization Oxidation Phase transformation
Résumé :	The phase transformation during pyrite concentrate oxidation under the conditions of the circulating fluidized bed (CFB) roasting process was experimentally studied at temperatures of 600-900 °C, O2 concentrations of 1%―21%, and particle residence times of ∼5.0 s in a drop tube furnace (DTF). The X-ray diffraction (XRD) and scanning electron microscopy (SEM) were used to analyze the phase composition and microstructure of the product samples. For the roasting process with a short residence time, the products of pyrite concentrate oxidation are in a nonequilibrium phase. At higher O2 concentration and temperature, Fe3O4 is the dominant product phase. When O2 concentration increases, the micromorphology of sample products tends to be perfectly spherical particles with smooth surface, difficult for the formed Fe3O4 to be oxidized to Fe2O3. Experimental results indicated that, in the CFB roasting, relatively high temperature and low O2 concentration are needed to control the phase transformation into Fe2O3.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299887

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 14162-14167

Titre :	Quantitative structure – property relationship (QSPR) modeling of normal boiling point temperature and composition of binary azeotropes
Type de document :	texte imprimé
Auteurs :	Vitaly P. Solov’ev, Auteur
Année de publication :	2012
Article en page(s) :	pp. 14162-14167
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Azeotropic mixture Boiling point Modeling Property structure relationship
Résumé :	Quantitative structure―property relationship (QSPR) modeling of normal boiling point temperature (Taz) and the composition (weight fraction, X1w) of 176 binary azeotropic mixtures was performed using ensemble multiple linear regression analysis and fragment descriptors implemented in ISIDA software. The models have been validated in external 5-fold crossvalidations procedure and on an additional test set of 24 azeotropes. The prediction errors (3―4 K for Taz and 10―14 wt % for X1w) are comparable with the noise in experimental data. A simple empirical relationship linking Taz with boiling points of two molecular components of azeotrope has been suggested.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299886

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 14155-14161

Titre :	Volumetric connectivity index : A new approach for estimation of density of ionic liquids
Type de document :	texte imprimé
Auteurs :	Yan Xiong, Auteur ; Jing Ding, Auteur ; Dahong Yu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 14155-14161
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Ionic liquid Density
Résumé :	A new approach named volumetric connectivity index (VCI) based on the physical observable volumes of groups and the concept of molecular connectivity index is proposed for the prediction of the density of ionic liquids (ILs). The capability of VCI in the prediction by combination of group (formula units) volumes for a new and as yet not prepared modification can provide an estimate of the density of that compound. In this work, the densities at room temperature of 142 pure ILs including imidazoliom, pyridinium, pyrrolidinium, piperidmium, quaternary ammonium, and quaternary phosphonium are estimated by this new model, and the results are compared with the experimental data collected from the most commonly used literatures. The average deviation for the prediction of all the 142 ILS is only 0.63%, and R2 and rmsd are 0.9971 and 0.01214 g·cm―3, respectively. Combined with a model called mass connectivity index (MCI), the new model can also be used to predict the densities of ILs at different temperatures accurately with the room temperature density obtained input in MCI.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299885

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 14148–14154

Titre :	Rheological investigation of prunus Sp. gums in aqueous medium
Type de document :	texte imprimé
Auteurs :	Gina Amarioarei, Auteur ; Iuliana Spiridon, Auteur ; Maria Lungu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 14148–14154
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Rheological behavior Aqueous medium
Résumé :	The paper presents the preparation and rheological behavior of exudate gum obtained from tree gum cherry (Prunus cerasus) in aqueous medium. The shear and oscillatory flow experiments as well as creep-recovery tests, performed in different conditions of shear at 37 °C, show peculiar behavior of the samples as a function of their composition. Rheological parameters are very sensitive to variations in molecular structure or intermolecular interactions, and they are useful in developing structure–function relationships for polysaccharide-based systems.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie2014179

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 14142–14147

Titre :	Vertically - oriented - capillary video - microscopy : drops levitated by a (Reacting) fluid
Type de document :	texte imprimé
Auteurs :	Miguel Garcia-Bermudes, Auteur ; Riccardo Rausa, Auteur ; Kyriakos Papadopoulos, Auteur
Année de publication :	2012
Article en page(s) :	pp. 14142–14147
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Microscopy
Résumé :	Microscopy in a vertical capillary provided the ability to continuously observe the dynamic particle phenomena on microscopic objects levitated by an imposed flow. Such a technique was developed and used to monitor flow-levitated droplets, by manually regulating the imposed flow so as to keep the droplets suspended in the area of view. Local sudden increases and decreases in temperature were achieved with an external heating filament, which produced rapid changes in the fluids’ properties (viscosity and density). Even in such cases it was possible to control the levitated drop’s position in the microscope’s field of vision by adjusting the levitating fluid’s vertical flow. The shrinkage and alteration of levitated acid drops that react with the basic nanoparticles of levitating oil, verified that, when compared to static conditions, fluid flow significantly accelerated the neutralization of the acid drop by the oil’s basic nanoparticles. Allowing droplets to levitate and rotate due to the flow of another fluid in high-temperature regions, this technique may be used as an improved way to mix contents in suspended microscopic droplets.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201409e

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 14136–14141

Titre :	Combustion characteristics of an Al/H2O mixture with polyoxyethylene
Type de document :	texte imprimé
Auteurs :	Yunlan Sun, Auteur ; Baozhong Zhu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 14136–14141
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Combustion Polyoxyethylene
Résumé :	An experimental investigation of the combustion characteristics of an aluminum/water (Al/H2O) mixture with the addition of polyoxyethylene (PEO) was conducted in argon at 0.1 MPa. The burning rates were obtained using a constant-pressure strand burner. Ignition and combustion processes of an Al/H2O mixture were observed with a high-speed camera. The results show that PEO addition can improve the ignition and combustion performance of an Al/H2O mixture. The mixture of nanosized Al powder and H2O cannot be ignited in argon at 0.1 MPa, but the mixture of nanosized Al powder and H2O with the mass fraction 1% PEO or 3% PEO can be ignited, and the mixture can be self-sustaining combustion. The burning rates are 2.57 mm/s and 3.94 mm/s, respectively. In the mixture of nanosized Al powder and H2O with 3% PEO, the ignition can be sustained when 20% nanosized Al powder is replaced by micrometer-sized Al powder, and the burning rate is 3.36 mm/s. However, the mixture would not be ignited when 25% nanosized Al powder is replaced by micrometer-sized Al powder. In addition, the combustion process and flame image characteristics were obtained by using a high-speed photography technique, and the condensed combustion products were characterized by scanning electron microscopy combined with energy dispersive X-ray.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201837a

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 14121-14135

Titre :	Population balance modeling of pulsed (Packed and Sieve - Plate) extraction columns : coupled hydrodynamic and mass transfer
Type de document :	texte imprimé
Auteurs :	Moutasem Jaradat, Auteur ; Menwer Attarakih, Auteur ; Hans-Jörg Bart, Auteur
Année de publication :	2012
Article en page(s) :	pp. 14121-14135
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Mass transfer Hydrodynamics Extraction column Perforated tray Modeling Population balance
Résumé :	Liquid―Liquid Extraction Column Module (LLECMOD) is a rigorous and comprehensive bivariate population balance framework for dynamic and steady-state modeling of liquid―liquid extraction columns. Within LLECMOD, the user can simulate different types of extraction columns, including stirred and pulsed ones. The basis of LLECMOD depends on stable robust numerical algorithms based on an extended version of a fixed pivot technique (to take into account interphase solute transfer) and advanced computational fluid dynamics (CFD) numerical methods. In this work, mathematical models for pulsed packed and sieve tray extraction columns are developed. The models are programmed using visual digital FORTRAN and then integrated into the LLECMOD population balance model. As a case study, the steady-state performance of pulsed packed and sieve-plate columns, under different operating conditions, which include pulsation intensity and volumetric flow rates, are simulated The effect of pulsation intensity is found to have a more profound effect on systems of high interfacial tension. On the other hand, the variation of volumetric flow rates has a substantial effect on the holdup, mean droplet diameter, and solute concentration profiles for chemical systems with low interfacial tension. Two chemical test systems recommended by the EFCE are used in the simulations. Model predictions are successfully validated against experimental data by adjusting the steady-state column hydrodynamics, using only droplet coalescence empirical parameters.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299881

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 14115-14120

Titre :	Influence of water vapor on carbonation of CaO in the temperature range 400 – 550 °C
Type de document :	texte imprimé
Auteurs :	Isak Lindén, Auteur ; Peter Backman, Auteur ; Anders Brink, Auteur
Année de publication :	2012
Article en page(s) :	pp. 14115-14120
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Carbonation Water vapor
Résumé :	The effect of water vapor on the kinetics of CO2 capture using CaO in the form of calcined limestone was determined by means of a thermogravimetric analyzer. The effect was studied at three different temperatures, 400, 450, and 550 °C; three different partial pressures of CO2, 0.05, 0.15, and 0.5 atm; and four different partial pressures of H2O, 0, 0.02, 0.1, and 0.3 atm. Calcined limestone with a particle size of 100―200 μm was used. For each condition the conversion as a function of time was determined. At 400 and 450 °C, water vapor had an accelerating effect on the conversion of CaO to CaCO3. At 500 °C, water vapor had no accelerating effect, instead it had a slightly retarding effect on carbonation. Regardless of the partial pressure of water vapor, higher temperature resulted in higher conversion. To study possible mass transfer limitations the effect of diluting the CaO sample with inert SiO2 was also studied.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299880

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 14105-14114

Titre :	Online data reconciliation with poor redundancy systems
Type de document :	texte imprimé
Auteurs :	Flavio Manenti, Auteur ; Maria Grazia Grottoli, Auteur ; Sauro Pierucci, Auteur
Année de publication :	2012
Article en page(s) :	pp. 14105-14114
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Data reconciliation
Résumé :	The paper deals with the integrated solution of different model-based optimization levels to face the problem of inferring and reconciling online plant measurements practically, under the condition of poor measure redundancy, because of a lack of instrumentation installed in the field. The novelty of the proposed computer-aided process engineering (CAPE) solution is in the simultaneous integration of different optimization levels: (i) the data reconciliation based on a detailed process simulation; (ii) the introduction and estimation of certain adaptive parameters, to match the current process conditions as well as to confer a certain generality on it; and (iii) the use of a set of efficient optimizers to improve plant operations. The online feasibility of the proposed CAPE solution is validated on a large-scale sulfur recovery unit (SRU) of an oil refinery.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299879

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp.14097–14104

Titre :	Investigation of the thermal regeneration efficiency of activated carbons used in the desulfurization of model diesel fuel
Type de document :	texte imprimé
Auteurs :	Mykola Seredych, Auteur ; Juliene Rawlins, Auteur ; Teresa J. Bandosz, Auteur
Année de publication :	2012
Article en page(s) :	pp.14097–14104
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Thermal regeneration
Résumé :	Adsorption of dibenzothiophene (DBT) and 4,6-dimethyldibenzothiophene (DMDBT) from model diesel fuel (MDF) was investigated on a thermally regenerated wood-based carbon and two polymer-derived carbons. The materials were characterized by thermal analysis, potentiometric titration, elemental analysis, adsorption of nitrogen, and mass spectroscopy. The selectivities of DBT and DMDBT were calculated using naphthalene as a reference. The regenerated carbons were found to be very good adsorbents for the desulfurization of MDF. Although most sulfur-containing compounds were adsorbed in the micropores, where dispersive forces govern the adsorption process, DBT and DMDBT were also retained in the larger pores as a result of acid–base and/or polar interactions. This increases the overall adsorption capacity and selectivity. Moreover, thermal regeneration of carbons containing acidic oxygen groups increases their sulfur content and, thus, the contribution of specific adsorption forces involving sulfur–sulfur interactions in both small and larger pores. A significant quantity of the DBT and DMDBT adsorbed in pores larger than 10 Å is oxidized to sulfoxides and sulfones. Sulfur functional groups likely promote this process through oxygen activation.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202159a

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp 14090–14096

Titre :	Multicomponent vapor – liquid – liquid equilibrium prediction using an a priori segment based model
Type de document :	texte imprimé
Auteurs :	Debashis Kundu, Auteur ; Tamal Banerjee, Auteur
Année de publication :	2012
Article en page(s) :	pp 14090–14096
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Vapor Liquid
Résumé :	An isobaric vapor–liquid–liquid equilibrium of eight hydrocarbon systems (seven ternary and one quaternary) has been predicted by equilibrium relations and flash relations. COSMO-SAC, a variant of the COSMO-RS model has been used to calculate the activity coefficients. For the prediction of VLLE, two approaches have been adopted. A modified Rachford–Rice algorithm was used in the equilibrium approach and the Henley–Rosen algorithm for the three phase flash calculation to predict the composition via the flash approach. Overall, the average root-mean-square deviation (rmsd) in the organic phase composition using the equilibrium approach for all the systems taken together is 10.67%. The rmsd values of 7.45% in the aqueous phase and 3.26% in the vapor phase were reported via equilibrium relations. The flash algorithm when applied for two systems, namely, water + 1-propanol + di-n-propyl ether and water + 2-propanol + di-iso-propyl ether, gave an overall average rmsd in the organic phase to be 19.17%, 4.03% in the aqueous phase, and 5.84% in vapor phase.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201864y

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 14084-14089

Titre :	Adsorption and diffusion of methanol, glycerol, and their mixtures in a metal organic framework
Type de document :	texte imprimé
Auteurs :	Yang, Li, Auteur ; Stanley I. Sandler, Auteur ; Dionisios G. Vlachos, Auteur
Année de publication :	2012
Article en page(s) :	pp. 14084-14089
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Diffusion Adsorption
Résumé :	Grand Canonical Monte Carlo (GCMC) simulation has been used to study the adsorption of methanol, glycerol, and their mixtures in the metal organic framework IRMOF-1, and canonical ensemble molecular dynamics simulation was used to study their diffusion in that adsorbent. In particular, we consider the adsorption of pure glycerol in IRMOF-1 at several different temperatures and the diffusion of pure glycerol in IRMOF-1 at infinite dilution. Then, we study the influence of the methanol as solvent and how different concentrations of methanol affect the behavior of glycerol in IRMOF-1. It It is found that the glycerol is easily adsorbed into IRMOF-1, and a small concentration of adsorbed methanol promotes glycerol adsorption. The effect of methanol on the glycerol diffusivity depends on temperature and methanol concentration.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299876

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 14070–14083

Titre :	Anionic dye adsorption on chemically modified ordered mesoporous carbons
Type de document :	texte imprimé
Auteurs :	Chun He, Auteur ; Xijun Hu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 14070–14083
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Adsorption Mesoporous Carbons
Résumé :	The surface chemistry of ordered mesoporous carbon CMK-3 was successfully modified by heat treatment in ammonia gas at a temperature of 1173 K, without destroying its hexagonally ordered mesoporous structure significantly. The adsorption kinetics and equilibrium of three commercial anionic dyes, i.e., orange II, reactive red 2 (RR2), and acid black 1(AB1), on the novel functionalized carbon were investigated. It was found that the ammonia-tailored CMK-3 showed a much higher uptake rate than that of a commercial activated carbon, due to its desirable ordered mesoporous structure and the electron-donating effect of the incorporated nitrogen-containing functional groups, particularly for the adsorption of the large molecule dye with a long chain, AB1. The dye initial concentration and adsorption temperature had little influence on the adsorption rate, while the size and spatial structure of dye molecules and the shaking speed played an important role during the adsorption process. The adsorption of AB1 which has a long chain required the longest time to reach equilibrium. Film mass transfer (the mass transport between the carbon surface and the flowing dye fluid) might be the rate-controlling step. This novel functionalized adsorbent could enhance the adsorption capacity of the three anionic dyes by 90–200% and 40–60% compared to the commercial activated carbon and unmodified CMK-3, respectively. This significant improvement was attributed to the enhanced dispersive forces between the carbon surface and the dye molecules induced by the nitrogen-containing functional groups. The Freundlich isotherm showed better correlation with the experimental adsorption data in all cases than the Langmuir isotherm as a result of the functional groups induced energetic heterogeneous surface. Slow desorption rate and low desorption efficiency of RR2 indicated that the adsorption of RR2 on the modified CMK-3 was extremely favorable, tending to be weakly reversible.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201469p

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 14061-14069

Titre :	Benzyl - functionalized room temperature ionic liquids for CO2/N2 separation
Type de document :	texte imprimé
Auteurs :	Shannon M. Mahurin, Auteur ; Thomas Dai, Auteur ; Joshua S. Yeary, Auteur
Année de publication :	2012
Article en page(s) :	pp. 14061-14069
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Carbon dioxide Ionic liquid
Résumé :	In this work, three classes of room temperature ionic liquids (RTILs), including imidazolium, pyridinium, and pyrrolidinium ionic liquids with a benzyl group appended to the cation, were synthesized and tested for their performance in separating CO2 and N2. All RTILs contained the bis(trifluoromethylsulfonyl)imide anion, permitting us to distinguish the impact of the benzyl moiety attached to the cation on gas separation performance. In general, the attachment of the benzyl group increased the viscosity of the ionic liquid compared with the unfunctionalized analogs and decreased the CO2 permeability. However, all of the benzyl-modified ionic liquids exhibited enhanced CO2/N2 selectivities compared with alkyl-based ionic liquids, with values ranging from 22.0 to 33.1. In addition, CO2 solubilities in the form of Henry's constants were also measured and compared with unfunctionalized analogs. Results of the membrane performance tests and CO2 solubility measurements demonstrate that the benzyl-fimctionalized RTILs have significant potential for use in the separation of carbon dioxide from combustion products.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299874

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 14055-14060

Titre :	Removal of the fermentation inhibitor, furfural, using activated carbon in cellulosic - ethanol production
Type de document :	texte imprimé
Auteurs :	Kuang Zhang, Auteur ; Manoj Agrawal, Auteur ; Justin Harper, Auteur
Année de publication :	2012
Article en page(s) :	pp. 14055-14060
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Production Activated carbon Fermentation
Résumé :	Ethanol can be produced from lignocellulosic biomass through fermentation; however, some byproducts from lignocellulosics, such as furfural compounds, are highly inhibitory to the fermentation and can substantially reduce the efficiency of ethanol production. In this study, commercial and polymer-derived activated carbons were utilized to selectively remove the model fermentation inhibitor, furfural, from water solution during bioethanol production. The oxygen functional groups on the carbon surface were found to influence the selectivity of sorbents between inhibitors and sugars during the separation. After inhibitors were selectively removed from the broth, the cell growth and ethanol production efficiency was recovered noticeably in the fermentation. A sorption/desorption cycle was designed, and the sorbents were regenerated in a fixed-bed column system using ethanol-containing standard solution. Dynamic mass balance was obtained after running four or five cycles, and regeneration results were stable even after twenty cycles.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299873

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 14046–14054

Titre :	Development of Novel Multichannel Rectangular Membranes with Grooved Outer Selective Surface for Membrane Distillation
Type de document :	texte imprimé
Auteurs :	May May Teoh, Auteur ; Na Peng, Auteur ; Tai-Shung Chung, Auteur
Année de publication :	2012
Article en page(s) :	pp. 14046–14054
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Multichannel Rectangular Membranes
Résumé :	In this study, poly(vinylidene fluoride) (PVDF) multichannel rectangular membranes were spun through the non-solvent-induced phase separation method with the aid of a specially designed spinneret. This unique spinneret has an outer rectangular slit and seven inner needles arranged in series. The newly designed membranes have the combined advantages offered by (1) hollow fiber (i.e., high membrane area per volume ratio and easy assembly into membrane modules); (2) flat sheet membranes (i.e., greater mechanical durability and compressibility); and (3) woven or nonwoven spacers used in flat sheet modules (as mechanical supports). Microscopic views and scanning electron microscopy (SEM) microphotographs show an irregular inner contour align symmetrically in the hydrophobic PVDF membrane. Multichannel rectangular membranes with a grooved pattern have the following advantages: (1) easy handling, (2) can be acted as spacers to discrete membrane from attaching together, and (3) creating eddies flow at the membrane outer selective layer. Attempts are also made to understand the deformation of grooved outer surface and irregular inner contour. Apart from interesting membrane geometry, this study also explores the prospect of utilizing aforementioned membranes for seawater desalination via direct contact membrane distillation (DCMD). A promising distillated flux of 54.7 kg m–2 s–1, using a hot feed brine solution of 80 °C, is obtained through these newly spun multichannel rectangular membranes.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201292j

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 14030–14045

Titre :	Separation of methane – nitrogen mixture by pressure swing adsorption for natural gas upgrading
Type de document :	texte imprimé
Auteurs :	S. J. Bhadra, Auteur ; S. Farooq, Auteur
Année de publication :	2012
Article en page(s) :	pp. 14030–14045
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Methane Adsorption Natural gas
Résumé :	A dynamic pressure swing adsorption simulation model has been developed that caters for a detailed transport mechanism of nitrogen and methane in the micropores of both ETS-4 and CMS adsorbents. Five adsorbents, namely, barium-exchanged ETS-4 dehydrated at 400 °C (Ba400), strontium-exchanged ETS-4 dehydrated at 190 °C (Sr190) and 270 °C (Sr270), Bergbau–Forchung carbon molecular sieve (BF CMS), and Takeda carbon molecular sieve (Takeda CMS), have been selected for the simulation study in order to compare their performances for upgrading natural gas. The transport mechanisms of gases in CMS and ETS-4 adsorbents are different. In pressure swing adsorption (PSA) simulation, the binary equilibrium and kinetics are represented by the models that have recently been experimentally verified for methane–nitrogen mixture in Ba400, Sr190, and Sr270 adsorbents [Majumdar, B.; Bhadra, S. J.; Marathe, R. P.; Farooq, S. Ind. Eng. Chem. Res.2011, 50, 3021]. The multisite Langmuir isotherm is used for adsorption equilibrium. The kinetic model takes into account diffusion in both macropores and micropores and the concentration dependence of micropore diffusivity according to the chemical potential gradient as the driving force with constant limiting micropore diffusivity. It also has the provision to allow for the dual transport resistance and strong concentration dependence of the thermodynamically corrected micropore transport coefficients in CMS according to the published results [Huang, Q.; Farooq, S.; Karimi, I. A. Langmuir2003, 19, 5722]. Operating conditions have been identified that favor high recovery while simultaneously meeting the required pipeline specification for methane purity. The performance of the best sample for methane–nitrogen separation by PSA found from the simulation study, Ba400, is compared with published performances of ETS-4 and clinoptilolite. It has been found that, in addition to meeting pipeline specification, Ba400 also gives higher recovery, thus making this adsorbent a promising candidate for further exploration.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201237x

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 14016–14029

Titre :	Performance evaluation of poly(amide - imide) incorporated cellulose acetate ultrafiltration membranes in the separation of proteins and its fouling propensity by AFM imaging
Type de document :	texte imprimé
Auteurs :	Sahadevan Rajesh, Auteur ; Ayyavoo Jayalakshmi, Auteur ; Sundararaj Senthilkumar, Auteur
Année de publication :	2012
Article en page(s) :	pp. 14016–14029
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Cellulose Ultrafiltration Membranes
Résumé :	Polymeric membranes intended to be used in protein separation must be fouling resistant in order to reduce the interactions with proteins during operation. Therefore, cellulose acetate (CA) membranes with superior properties were prepared by phase inversion technique using high-performance thermoplastic poly(amide-imide) (PAI) as the modification agent. The prepared membranes were characterized using attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), scanning electron microscopy (SEM), atomic force microscopy (AFM), molecular weight cutoff, and pore size to investigate the influence of PAI on the properties of the resultant membranes. Intermolecular interactions between the components in blend membranes were established by ATR-FTIR and SEM analysis showed that the blend CA membranes have thinner top layer and higher porosity in the sublayer. These prepared membranes were subjected to the separation of proteins such as bovine serum albumin, egg albumin, pepsin, and trypsin. The fouling-resistant capability of the membranes was studied by bovine serum albumin as the model protein and increase in resistance during protein filtration was calculated by means of resistance in series model analysis. The fouled membranes were characterized by AFM imaging and these membranes were cleaned by washing with deionized water and subsequent sonication. From the AFM images of the fouled membranes it was clear that preferential adsorption takes place at specific locations on the membrane surface and is a function of surface roughness and membrane hydrophilicity. It is worth mentioning that the incorporation of poly(amide-imide) into the cellulose acetate matrix is an effective method for the development of low fouling ultrafiltration membranes for the separation of proteins.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201181h

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 14008-14015

Titre :	Correlations for equilibrium solubility of carbon dioxide in aqueous 4 - (Diethylamino) - 2 - butanol solutions
Type de document :	texte imprimé
Auteurs :	Teerawat Sema, Auteur ; Abdulaziz Naami, Auteur ; Raphael Idem, Auteur
Année de publication :	2012
Article en page(s) :	pp. 14008-14015
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Carbon dioxide Solubility Correlation analysis Correlation
Résumé :	The experimental results of the equilibrium solubility of CO2 in aqueous 4-(diethylamino)-2-butanol (DEAB) solutions are reported over the temperature range of 298–333 K, CO2 partial pressure range of 10–100 kPa, and DEAB concentration range of 1–2.5 M. These results were then used to calculate, with the help of various thermodynamic models, the equilibrium solubility constant of CO2 in aqueous DEAB solutions as a function of various operating parameters. Subsequently, data for the chemical equilibrium constant that governs the CO2–DEAB–water reaction were fitted to the correlation models of Kent–Eisenberg, Austgen, Li–Shen, and Hu–Chakma and used to predict the equilibrium solubility as a function of temperature and CO2 partial pressure. The results show that these models did not represent the CO2 equilibrium solubility in aqueous DEAB solution very well, with absolute average deviations of 7.3%, 7.3%, 7.1%, and 8.3%, respectively.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299869

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13997-14007

Titre :	Synergy pinch analysis of CO2 desorption process
Type de document :	texte imprimé
Auteurs :	Yun S. Yu, Auteur ; Yun Li, Auteur ; Hong F. Lu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13997-14007
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Desorption Carbon dioxide Synergism
Résumé :	To reduce the regeneration costs of capturing CO2 with absorbents, a two-dimensional desorption model for two-phase flow has been proposed. The temperature and pressure predicted by the model were found to agree well with the experiment data. A new synergy pinch concept was proposed to determine the interactive synergy impacts on mass and heat transfer. According to the proposed synergy pinch principle, the carbon surplus (SAC) and energy surplus (SAE) were defined to quantify the synergy effects for mass and heat transfer, respectively. The proposed synergy pinch principle is that the lower the values of SAC and SAE, the more effective the CO2 desorption. In addition, the synergy pinch point can be identified at the ideal value of zero SAC and SAE. Based on this analysis, a stripper with fin internals was introduced that could contribute energy savings of about 10―14% by synergizing the fluid flow between mass and heat transfer. Thus, it was verified that the synergy pinch method can be effectively applied in CO2 emissions control.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299868

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13990-13996

Titre :	Extraction of th (IV) from an HNO3 solution by diglycolamide in ionic liquids
Type de document :	texte imprimé
Auteurs :	Yinglin Shen, Auteur ; Shaofei Wang, Auteur ; Lun Zhu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13990-13996
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Ionic liquid
Résumé :	Extraction of thorium(IV) from a nitric acid solution into various 1-alkyl-3-methylimidazolium hexafluorophosphate ([Cnmim] [PF6], n = 4,6,8) ionic liquids (ILs) was investigated using N,N,N',N'-tetrabutyl-3-oxapentanediamide (TBDA) and N, N'-dimethyl-N,N'-dibutyl-3-oxapentanediamide (MBDA) as the extractants, The extraction efficiency of Th4+ ions in the ionic liquid is higher than that obtained in chloroform under low nitric acid concentration. The extraction mechanism has been studied by slope analysis, UV―vis measurement, and extraction tests. The conventional log―log plot analysis of the extraction equilibrium data reveals that Th4+ ions are extracted as cation complexes characterized by a metal/ligand ratio of 1:2 using MBDA as an extractant. In addition Th4+ ions form 1:2 complexes with TBDA in [bmim]PF6 and [hmim]PF6 and 1:1 complexes in [omim][PF6] and chloroform. The mode of partitioning of thorium ions into [bmim]PF6 and [hmim]PF6 with TBDA appears to proceed predominantly via a cation-exchange mechanism, whereas for [omim][PF6] thorium extraction mechanism is changed from an cation-exchange process to one involving extraction of a neutral thorium-TBDA-nitrato complex as the aqueous nitrate concentration is increased.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299867

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13984-13989

Titre :	Compressor heuristics for conceptual process design
Type de document :	texte imprimé
Auteurs :	William L. Luyben, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13984-13989
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Design Compressor
Résumé :	Multiple compressors in series with intermediate heat exchangers are frequently used to reduce compressor energy consumption or to limit compressor discharge temperatures when the overall compression ratio (initial suction pressure divided by the required final pressure) is large. The optimum number of stages can be fixed by economics (trade-offbetween capital investment and energy cost) or by equipment and/or process compressor discharge temperature limitations. The chemical engineering design literature contains several conflicting heuristics for designing multistage gas compression systems, and little information about the rationale behind these heuristics is provided. This paper explores several aspects of multistage compression systems including economics, equipment temperature limitations, and process temperature limitations. New heuristics are presented that give either the economic optimum or the temperature-limited number of stages as a function of the overall compression ratio.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299866

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13969-13983

Titre :	Transition process modeling and monitoring based on dynamic ensemble clustering and multiclass support vector data description
Type de document :	texte imprimé
Auteurs :	Zhibo Zhu, Auteur ; Zhihuan Song, Auteur ; Palazoglu Ahmet, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13969-13983
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Surveillance Modeling
Résumé :	Monitoring and management of process transitions is a critical activity in chemical plants due to increased potential for abnormal operations. This activity is often hampered by the lack of a proper approach to label the transition states. In this paper, we present a systematic framework that constructs process transition states thus facilitating their monitoring for faulty operations. To address the nonstationary and non-Gaussian characteristics of the time series data collected during the transition process, an ensemble clustering method based on dynamic k-principal component analysis-independent component analysis (k-ICA-PCA) models is proposed to enable labeling of transitions. Next, we combine a PCA-based dimension reduction with a pattern classification strategy based on multiclass support vector data description (SVDD) to achieve transition process monitoring. The Tennessee Eastman (TE) benchmark process is used as a case study to evaluate the performance of the proposed framework.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299865

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13962–13968

Titre :	Zeolite - based process for CO2 capture from high - pressure, moderate - temperature gas streams
Type de document :	texte imprimé
Auteurs :	James C. Fisher, Auteur ; Ranjani V. Siriwardane, Auteur ; Robert W. Stevens, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13962–13968
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Zeolite Gas streams
Résumé :	A novel CO2 capture process was developed using a zeolite suitable for CO2 removal at warm-gas temperatures in high-pressure coal gasification gas streams. The process involves sorption of CO2 at 150 °C and regeneration at 350 °C. Regeneration at 350 °C removes the moisture absorbed during CO2 sorption. This sorption temperature is ideal for CO2 removal downstream of the water gas shift reactor in an integrated gasification combined cycle (IGCC) power plant but is also applicable to other warm gas cleanup processes. Most solvent-based processes require energy-intensive drying to remove moisture prior to CO2 removal. Using zeolites for CO2 capture at 150 °C and regeneration at 350 °C eliminates the problem with moisture in the gas stream traditionally causing deactivation of the zeolite. The results of using this capture scheme in an IGCC power plant is advantageous because of the high-pressure CO2 product stream and because removal of CO2 and H2O from the syngas generates high-quality H2 for the combustion turbines. In the example used in this work, the resulting CO2 stream separated from the fuel gas is delivered at 280 psi significantly reducing the energy required for compression from 27.6 MW in the EPRI report utilizing Selexol to 9.9 MW in this work. The overall thermal efficiency of the plant utilizing this CO2 removal scheme was estimated at 36.5, which is 0.5% less than the comparable Selxol plant. However, this process, combined with other warm gas cleanup technologies, offers the ability to significantly reduce the auxiliary load associated with syngas clean up, thereby increasing overall power plant efficiency.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201666g

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13954–13961

Titre :	Embedded interval type - 2 T - S fuzzy time / space separation modeling approach for nonlinear distributed parameter system
Type de document :	texte imprimé
Auteurs :	Mengling Wang, Auteur ; Ning Li, Auteur ; Shaoyuan Li, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13954–13961
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Distributed parameter system Modeling
Résumé :	Challenging modeling problems include how to obtain a simple and accurate model for a partial differential equation (PDE) unknown nonlinear distributed parameter system (DPS). In this paper, a time/space separation modeling approach based on the interval type-2 T-S fuzzy model (IT2 T-S model) is proposed for nonlinear DPS. First, the spatial-temporal output is divided into a few dominant spatial basis functions and low-dimensional time series by a linear time/space separation method. Second, the interval type-2 T-S fuzzy model is determined from the low-dimensional time series to reconstruct the system dynamics through the spatial basis functions. As the IT2 T-S model employs an interval linear model in the consequent part, the relationship between the input and spatial output can be determined by linear expressions through type reduction and linear time/space reconstruction. Thus, the obtained model is suitable for control design. The simulation presents the accuracies and effectiveness of the proposed modeling methodologies.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299863

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13947–13953

Titre :	A hybrid denitrification – alternate cycles reactor to enhance the nitrogen biological removal in a real wastewater treatment plant
Type de document :	texte imprimé
Auteurs :	M. Santinelli, Auteur ; A. L. Eusebi, Auteur ; E. Cola, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13947–13953
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Hybrid Nitrogen Biological
Résumé :	This paper involves the retrofitting of a real municipal wastewater treatment plant (WWTP) of 6600 population equivalent (PE), from a traditional biological process to a predenitrification–alternating cycles (PreD-AC) technology, defining a hybrid reactor. The application was investigated for 11 months, from the upgrading in October 2009 to September 2010. The process optimization allowed to reach high standards of effluent’s quality, with total nitrogen (TN) and ammonia (NH4-N) concentrations lower than 15 and 1 mg L–1, respectively. Moreover, the flexibility and automatic control of the process guaranteed an energy consumption decrease of 17%, with a specific energy consumption of 0.18 kWh PETN–1 d–1 as an average value. A reduction of 20% was reached by comparing the sludge amounts disposed in landfills in 2009 and 2010.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201346f

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13940-13946

Titre :	On the integrity of uncertain systems with structured uncertainty
Type de document :	texte imprimé
Auteurs :	Majid Firouzbahrami, Auteur ; Amin Nobakhti, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13940-13946
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Uncertainty Uncertain system
Résumé :	The integity of decentralized controllers with integral action, with respect to loop failures, has been researched relatively well. Important results have been found, with respect to the Relative Gain Array (RGA). However, less has been done on the treatment of the integrity of uncertain systems. This paper builds on the more-recent progress on the analysis of uncertain systems and presents new conditions for the integrity of closed-loop systems. The developed Integral Controllable (IC), Integal Controllable with Integrity (ICI), and Decentralized Integral Controllability (DIC) conditions are derived using a model of uncertainties that allows both unstructured and structured independent uncertainties to be studied. A convex framework for the evaluation of the conditions is also presented. The utility of the conditions are illustrated through application to existing examples from the literature.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299861

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp 13932–13939

Titre :	Simulation of the generation of solution gradients in microfluidic systems using the lattice boltzmann method
Type de document :	texte imprimé
Auteurs :	Yangxu Hu, Auteur ; Xianren Zhang, Auteur ; Wenchuan Wang, Auteur
Année de publication :	2012
Article en page(s) :	pp 13932–13939
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Fluid mechanics Microfluidics
Résumé :	In this work, we used the lattice Boltzmann (LB) method to simulate the generation of concentration gradients in microfluidic networks. We first developed a model of microfluidic networks, in which the flow velocity of the laminar flow in the microchannel and the diffusion of solute molecules govern the solute gradients generated, and the obtained results are comparable with experimental data. Our simulation results indicated that the relative positions of the branching plates in different levels, at which a microchannel is split into several daughter microchannels, exert significant effects on the shape of concentration gradients. We also performed extensive simulations to study the dependence of the shape of the concentration gradient on the velocity of the flow u, diffusion coefficients of solutes D, and the length of the microchannel L. A dimensionless parameter, (L/u)/(H2/D), in which H is the hydraulic diameter of the main microchannel, was proposed in this work. It is found that for geometrically similar microfluidic networks, the parameter alone determines the shape of the generated concentration gradient. Therefore, the proposed parameter allows one to perform experiments or simulations with reduced models in microchannels and correlate the data to the other flows or geometry sizes.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299860

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13922–13931

Titre :	Effects of process variables on the properties of spray - dried mannitol and mannitol / disodium cromoglycate powders suitable for drug delivery by inhalation
Type de document :	texte imprimé
Auteurs :	Katarzyna Kramek-Romanowska, Auteur ; Marcin Odziomek, Auteur ; Tomasz R. Sosnowski, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13922–13931
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Cromoglycate
Résumé :	Understanding the influence of process conditions on the properties of pharmaceutical products is critical to their optimal and cost-effective design and manufacture. The aim of this study was to investigate the effect of changing processing variables on the physical properties of spray-dried mannitol and co-spray-dried mannitol/disodium cromoglycate (DSCG) formulations intended for therapeutic inhalation. A 24 full factorial design was performed to assess the consequences of altering the following spray-drying parameters: feed flow rate, nozzle gas flow rate, drying gas inlet temperature, and aspirator capacity (drying gas flow rate). Aqueous solutions of mannitol and mannitol/DSCG were spray-dried using a laboratory-scale spray dryer, and the products were characterized in terms of particle size distribution, powder yield, and particle morphology. These physical properties were found to be affected mainly by two processing variables: nozzle gas flow rate and drying gas inlet temperature. In addition, optimal conditions for the production of inhalable mannitol powders were obtained, generating a yield of 90% by weight of round and smooth particles with a volume median diameter of 4.28 μm. Mannitol/DSCG formulations co-spray-dried in the same conditions had similar characteristics. The results of this study can be applied to controlled formulation of various spray-dried powders for inhalation.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie2006998

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp.13911–13921

Titre :	Simulation of electrodialysis with bipolar membranes : estimation of process performance and energy consumption
Type de document :	texte imprimé
Auteurs :	Yaoming Wang, Auteur ; Anlei Wang, Auteur ; Xu Zhang, Auteur
Année de publication :	2012
Article en page(s) :	pp.13911–13921
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Electrodialysis Bipolar membranes
Résumé :	A mathematical model of a typical three-compartment electrodialysis with bipolar membranes (EDBM) process has been developed to calculate the energy consumption and total cost of the process. In particular, gluconic acid was chosen as a model product, the energy consumption was calculated on the basis of the Nernst–Planck equation, Donnan equilibrium, and electroneutrality assumption. The concentration profiles and resistance distributions across the respective layers were also displayed. Results indicated that the resistances of the solutions, diffusion layers, and Donnan interfaces were highly dependent on the applied current. The resistances in the diffusion layers were the dominant resistances, while the resistances due to Donnan interfaces and resistances of the membranes could be neglected. The energy consumption of an EDBM process was increased with an increase in current. The energy consumption in the validation experiment was in good agreement with the prediction, suggesting the reliability of the model.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie200467s

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13899–13910

Titre :	Algorithm for long - term scheduling of multiproduct pipelines
Type de document :	texte imprimé
Auteurs :	S. A. MirHassani, Auteur ; S. Moradi, Auteur ; N. Taghinezhad, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13899–13910
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Multiproduct Pipelines
Résumé :	In this article a mixed integer linear programming (MILP) model is presented for scheduling a multiproduct oil pipeline that connects a refinery to a few distribution centers. The scheduling task was carried out while considering a number of aspects such as satisfying daily demand, forcing settling periods for quality control, observing prespecified shutdown periods, and calculating batch size by considering the type of product. Finally, an approach to solve the model in long-term planning is proposed. The algorithm is able to achieve a near-optimal solution in reasonable running time.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie200101a

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13892–13898

Titre :	Adsorption Interaction of Tetracyclines with Porous Synthetic Resins
Type de document :	texte imprimé
Auteurs :	Weiben Yang, Auteur ; Fangfang Zheng, Auteur ; Yipin Lu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13892–13898
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Adsorption
Résumé :	The presence of tetracycline antibiotics (TCs) in aquatic environments poses potential risks to human health and ecosystems. In the present study, hypercrosslinked resins MN-200 and NDA-150 and aminated polystyrene resins MN-150 and MN-100 were selected as adsorbents for removing two tetracyclines, TC and oxytetracycline, OTC, from aqueous solutions. Despite the different surface properties and pore structures of the resins, similar patterns of pH-dependent adsorption were observed. The TCs adsorption on the resins exhibited ionic strength dependence, which is consistent with their adsorption mechanism. OTC presented stronger adsorption at pH 2.0 compared with TC; this is ascribed to the enhancement by H-bonding. The proposed mechanisms for TCs adsorption at lower pH are dependent on H-bonding, hydrophobic effect, and π–π electron donor–acceptor (EDA) interaction, whereas those at higher pH are regarded as the coordination of π–π EDA interaction and hydrophobic effect. The findings indicate that the hypercrosslinked resin is a promising adsorbent for the removal of antibiotics from aqueous solutions.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202166g

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13885–13891

Titre :	Morphology, crystallization behavior, and dynamic mechanical properties of biodegradable poly (E - caprolactone) / thermally reduced graphene nanocomposites
Type de document :	texte imprimé
Auteurs :	Jinbing Zhang, Auteur ; Zhaobin Qiu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13885–13891
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Morphology Biodegradable Nanocomposites
Résumé :	Biodegradable poly(E-caprolactone) (PCL)/thermally reduced graphene (TRG) nanocomposites were prepared via a solution mixing method at low TRG loadings in this work. Transmission electron microscopy and high resolution transmission electron microscopy observations reveal that a fine dispersion of TRG has been achieved throughout the PCL matrix. Scanning electron microscopy observation shows not only a nice dispersion of TRG but also a strong interfacial adhesion between TRG and the matrix, as evidenced by the presence of some TRG nanosheets embedded in the matrix. Nonisothermal melt crystallization behavior, isothermal melt crystallization kinetics, spherulitic morphology, and crystal structure of neat PCL and the PCL/TRG nanocomposites were studied in detail with various techniques. The experimental results indicate that both nonisothermal and isothermal melt crystallization of PCL have been enhanced significantly by the presence of TRG in the nanocomposites due to the heterogeneous nucleation effect; however, the crystallization mechanism and crystal structure of PCL do not change. Dynamic mechanical analysis study shows that the storage modulus of the nanocomposites has been greatly improved by about 203% and 292%, respectively, with incorporating only 0.5 and 2.0 wt % TRG at −80 °C as compared with neat PCL.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202132m

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13877–13884

Titre :	Molecular docking simulations for macromolecularly imprinted polymers
Type de document :	texte imprimé
Auteurs :	David R. Kryscio, Auteur ; Yue Shi, Auteur ; Pengyu Ren, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13877–13884
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Macromolecularly Polymers
Résumé :	Molecularly imprinted polymers are fully synthetic antibody mimics prepared via the cross-linking of organic monomers in the presence of an analyte. This general procedure is now well developed for small-molecule templates; however, attempts to extend the same techniques to the macromolecular regime have achieved limited success to date. We employ molecular docking simulations to investigate the interactions between albumin, a common protein template, and frequently employed ligands used in the literature at the molecular level. Specifically, we determine the most favorable binding sites for these ligands on albumin and determine the types of noncovalent interactions taking place based on the amino acids present near this binding pocket. Our results show that hydrogen-bonding, electrostatic, and hydrophobic interactions occur between amino acid side chains and ligands. Several interactions are also taking place with the polypeptide backbone, potentially disrupting the protein’s secondary structure. We show that several of the ligands preferentially bind to the same sites on the protein, which indicates that if multiple monomers are used during synthesis, then competition for the same amino acids could lead to nonspecific recognition. Both of these results provide rational explanations for the lack of success to date in the field.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201858n

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13866–13876

Titre :	Additive - driven dissolution enhancement of colloidal silica. : 2. environmentally friendly additives and natural products
Type de document :	texte imprimé
Auteurs :	Konstantinos D. Demadis, Auteur ; Eleftheria Mavredaki, Auteur ; Maria Somara, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13866–13876
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Colloidal silica
Résumé :	The effect of various environmentally friendly chemical additives and natural products on the dissolution of amorphous silica (Aerosil 200 and laboratory-synthesized, SSD) is studied. The silica scale dissolvers tested include the following: ascorbic acid (vitamin C, ASC), citric acid (CITR), carboxymethyl inulin (CMI), 3,4-dihydroxybenzoic acid (catechuic acid, DHBA), 3,4,5-trihydroxybenzoic acid (gallic acid, GA), dopamine hydrochloride (DOPA), iminodiacetic acid (IDA), histidine (HIST), phenylalanine (PHALA), and malic acid (MAL). The chemical structures of these chemical additives contain potentially dissolution-active moieties, such as 1,2-dihydroxyethylene (ASC), α-hydroxycarboxylate (MAL and CITR), catecholate (DHBA, GA, and DOPA), α-aminocarboxylate (HIST and PHALA, both aminoacids), and finally carboxy-modified fructofuranose units (CMI). It was found that all studied molecules showed variable dissolution efficiency, with MAL, CMI, HIST, and PHALA being the slowest/least effective dissolvers, and the catechol-containing DHBA, GA, and DOPA being the most effective ones. IDA and CITR have intermediate efficiency.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201798e

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13859-13865

Titre :	Morphology and properties of thermoplastic sugar beet pulp and poly (butylene adipate - co - terepthalate) blends
Type de document :	texte imprimé
Auteurs :	Bo Liu, Auteur ; Sachin Bhaladhare, Auteur ; Peng Zhan, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13859-13865
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Morphology
Résumé :	In this work, sugar beet pulp (SBP), the residue remaining after sugar extraction, was first turned into a thermoplastic-like compound by extrusion in the presence of water and glycerol. The resulting thermoplastic SBP (TSBP) was then blended with poly(butylene adipate-co-terepthalate) (PBAT) and extruded into sheets in a single process. The effects of polymeric diphenyl methane diisocyanate (pMDI) as compatibilizer and TSBP content on rheological properties, phase morphology, mechanical properties, and water absorption of the extruded sheets were studied. In comparison, dried SBP powder was also blended with PBAT by extrusion. It was found that when SBP was used as a plastic in compounding, it yielded blends with much finer dispersion of the SBP phase than when SBP was used as a filler in compounding. The dispersion of SBP in the blends was greatly improved with the addition of pMDI. The PBAT/SBP blends with fine phase morphology showed enhanced mechanical properties and moisture resistance.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299852

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp.13854–13858

Titre :	Preservation of carbon dioxide clathrate hydrate at temperatures below the water freezing point under atmospheric pressure
Type de document :	texte imprimé
Auteurs :	Duo Sun, Auteur ; Yusuke Shimono, Auteur ; Satoshi Takeya, Auteur
Année de publication :	2012
Article en page(s) :	pp.13854–13858
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Atmospheric pressure Freezing Clathrate Carbon dioxide
Résumé :	This paper reports the experimental study on the preservation of CO2 hydrate crystal samples at domestic freezer conditions for 3 weeks. These samples were characterized by initial hydrate mass fractions of 0.95 and 0.50, by particle diameters of smaller than 2.8, 2.8–4.0, and 5.6–8.0 mm and greater than 8.0 mm, and also by preservation temperatures at 258 and 253 K. The results revealed that the stability of CO2 hydrate depends on the particle size, the initial hydrate mass fractions in the samples, and the preservation temperatures. Better stability was observed for CO2 hydrate crystal samples of larger particle size and lower initial hydrate fraction and preserved at lower temperature. Visual observations of CO2 hydrate crystal samples showed that dissociation occurs on the surface of the crystal samples. These experimental results indicated the possibility of the development of novel food/drink products containing CO2 hydrate.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299851

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13848-13853

Titre :	Preparation of nickel nanoparticles in spherical polyelectrolyte brush nanoreactor and their catalytic activity
Type de document :	texte imprimé
Auteurs :	Zhongming Zhu, Auteur ; Xuhong Guo, Auteur ; Shuang Wu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13848-13853
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Catalyst activity Polyelectrolyte Nanoparticle Preparation
Résumé :	Nickel nanoparticles (Ni-NPs) with controlled size and narrow size distribution were successfully prepared in spherical poly (acrylic acid) (PAA) brushes (SPBs). The brushes act as nanoreactors for generating the Ni-NPs via adsorption of nickel ions in the brushes and subsequent reduction by addition of NaBH4. The size of Ni-NPs can be well-controlled in several nanometers and with narrow size-distribution. Most interestingly, the size can be tuned by the reaction temperature: the average size increased from 3 to 7 nm upon increasing the reaction temperature from 273 to 303 K. The catalytic activity of these Ni-NPs trapped in SPBs were evaluated using a model reaction based on the reduction of 4-nitrophenol to 4-aminophenol by NaBH4. The kinetic data were observed to follow the pseudofirst-order rate law, and the apparent rate constant was linearly dependent on the total surface area of the Ni-NPs and the reaction temperatures. This work opens a new way to prepare well-controlled Ni-NPs which should be ideal candidates for catalysts with high performance.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299850

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13840-13847

Titre :	Ultrasonic irradiation enhanced cell nucleation in microcellular poly (lactic Acid) : a novel approach to reduce cell size distribution and increase foam expansion
Type de document :	texte imprimé
Auteurs :	Jing Wang, Auteur ; Wentao Zhai, Auteur ; Jianqiang Ling, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13840-13847
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Expansion Foam Particle size distribution
Résumé :	The preparation of poly(lactic acid) (PLA) foam with a well-defined cell structure, high crystallinity, a high expansion ratio, and good mechanical properties is critical to its broader applications. However, achieving these properties in PLA foam simultaneously is challenging, because high crystallinity generally results in nonuniform cell nucleation and suppresses cell growth in the case of solid-state foaming. This study presents a novel approach using ultrasonic irradiation (UI) to achieve the desired properties in PLA simultaneously. As expected, CO2-saturated PLA samples at 5 MPa have a high crystallinity (23.4%), and foamed PLA samples at various foaming temperatures exhibit low foam expansion and nonuniform cell structure. By introducing UI at the very start of the foaming, however, the resultant PLA foams presented a significant and concurrent increase in cell structure uniformity and cell density: cell density increased about 2 orders of magnitude, the expansion ratio increased 1–2 times, the elongation at break increased 2 times, and the specific tensile strength increased 1.1 times, compared to samples without UI. Further investigation indicated that the enhanced cell nucleation induced by UI was the main reason for this unique phenomenon. Our study provides a simple but efficient and cost-effective method to fabricate PLA foams that possess excellent mechanical properties.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299849

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13831-13839

Titre :	Design of aerosol coating reactors : precursor injection
Type de document :	texte imprimé
Auteurs :	Beat Buesser, Auteur ; Sotiris E. Pratsinis, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13831-13839
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Precursor Reactor Aerosols Design
Résumé :	Particles are coated with thin shells to facilitate their processing and incorporation into liquid or solid matrices without altering core particle properties (coloristic, magnetic, etc.). Here, computational fluid and particle dynamics are combined to investigate the geometry of an aerosol reactor for continuous coating of freshly made titanium dioxide core nanoparticles with nanothin silica shells by injection of hexamethyldisiloxane (HMDSO) vapor downstream of TiO2 particle formation. The focus is on the influence of HMDSO vapor jet number and direction, in terms of azimuth and inclination jet angles, on process temperature and coated particle characteristics (shell thickness and fraction of uncoated particles). Rapid and homogeneous mixing of core particle aerosol and coating precursor vapor facilitates synthesis of core–shell nanoparticles with uniform shell thickness and high coating efficiency (minimal uncoated core and free coating particles).
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299848

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13825–13830

Titre :	Synthesis of mesoporous carbons from bituminous coal tar pitch using combined nanosilica template and KOH activation
Type de document :	texte imprimé
Auteurs :	Shitang Tong, Auteur ; Lei Mao, Auteur ; Xiaohua Zhang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13825–13830
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Mesoporous Nanosilica
Résumé :	Mesoporous carbons (MCs) facilitate mass transport in pore networks and enhance the performance of porous carbon. By combining a nanosilica template with KOH activation, highly porous MCs with BET specific surface areas (SBET) greater than 1000 m2/g were synthesized from unmodified commercial coal tar pitch. The MCs had a honeycomblike morphology with randomly arranged macropores. An increase in template amount resulted in an increase in pores larger than 20 nm, the size of silica template. An MC sample activated at 850 °C for 2 h with a KOH-to-carbon ratio of 2.7:1 and a pitch-to-template ratio of 3:1 had an SBET value of 1366 m2/g, 65 vol % mesopores, 19 vol % macropores, and an average pore diameter of 25 nm. Whereas the silica template was largely responsible for macropores and large mesopores, KOH created new micropores and enlarged existing pores through KOH–carbon reactions. Moreover, KOH enhanced the formation of carbonyl, carboxyl, and lactonic groups on the carbon surface. The feasibility of synthesizing MCs from an unmodified commercial carbon precursor with a simpler route was demonstrated.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201565x

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13819–13824

Titre :	Influence of nanoclay concentration on the CO2 diffusion and physical properties of PMMA montmorillonite microcellular foams
Type de document :	texte imprimé
Auteurs :	Vera Realinho, Auteur ; Marcelo Antunes, Auteur ; Antonio B. Martinez, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13819–13824
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Nanoclay concentration Microcellular foams
Résumé :	Microcellular foams of poly(methyl methacrylate) with variable concentrations of an organically modified montmorillonite, oMMT (2.5–10 wt %), were prepared using a supercritical CO2 dissolution physical foaming process. Particular importance was given to the analysis of the influence of the montmorillonite on the CO2 desorption behavior out of the several nanocomposites. The saturation concentration of CO2 was found to be two times higher in the nanocomposites when compared to the pure PMMA and a comparative analysis of the desorption curves showed that a higher concentration of CO2 remained in the nanocomposites for long times when compared to PMMA, except for the 10 wt % oMMT nanocomposite. Also, the incorporation of oMMT promoted the formation of submicrometric foams with much lower cell sizes and higher cell densities. With increasing the amount of oMMT, the glass transition temperature of PMMA decreased in both the solids and foams and important improvements were observed regarding the specific elastic moduli of the foams, demonstrating the mechanical reinforcement effect of oMMT.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201532h

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13813–13818

Titre :	Preparation of roxithromycin - loaded poly (l - lactic acid) films with supercritical solution impregnation
Type de document :	texte imprimé
Auteurs :	Jin-Peng Yu, Auteur ; Yi-Xin Guan, Auteur ; Shan-Jing Yao, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13813–13818
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Roxithromycin
Résumé :	Supercritical solution impregnation (SSI) was applied to prepare drug-loaded biodegradable films where poly(l-lactic acid) (PLLA) was used as the matrix and roxithromycin as the model drug. The effects of impregnation time, operating temperature, and pressure on drug loading capacity (DLC) of roxithromycin into PLLA matrix were investigated. With the extension of impregnation time, DLC increased gradually to an equilibrium value. DLC was also affected by impregnation temperature and pressure. At the optimal condition, i.e., impregnating at 70 °C and 300 bar for 2 h, the maximal DLC was approximately 10.5%. After SSI process, the PLLA film was still transparent. The SEM images showed that the morphologies of PLLA film did not change with the SSI process. The DSC data and XRD spectra demonstrated that roxithromycin molecules were dispersed into the PLLA film in an amorphous state and the SCCO2 processed PLLA film had a lower crystal degree than raw PLLA film. The residual dichloromethane due to the PLLA film preparation could be removed effectively during the SSI process and meet the Chinese Pharmacopoeia limit. In vitro release of roxithromycin consisted of two stages: initial rapid release and a following slow release. The SSI process is expected to be a promising technique to prepare a drug-loaded biodegradable polymer surface and matrix for antibacterial therapeutic implants.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201294u

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13805–13812

Titre :	Preparation of drug nanoparticles using a T - junction microchannel system
Type de document :	texte imprimé
Auteurs :	Qian-Xia Zhang, Auteur ; Li-Min Xu, Auteur ; Yue Zhou, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13805–13812
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Nanoparticles
Résumé :	Cefuroxime axetil (CFA) drug nanoparticles were prepared by liquid antisolvent precipitation in a microchannel system with a T-shaped junction formed by a main microchannel and a branch. Isopropyl ether as the antisolvent (high flow rate) was usually passed through the main microchannel, and CFA acetone solution as the solvent (low flow rate) was injected into the branch simultaneously. The solvent diffused from the CFA acetone solution stream into the antisolvent phase, which resulted in the supersaturation of CFA and thus led to the rapid precipitation of CFA nanoparticles. The change of the injection phase from CFA acetone solution to isopropyl ether was found to have a significant effect on the formation of CFA nanoparticles owing to the different contact behavior. The morphology and size of CFA nanoparticles were characterized by scanning electronic microscopy (SEM) and particle size distribution (PSD) measurements by laser diffractometry. Furthermore, the effects of CFA acetone solution velocity, antisolvent velocity, overall velocity, and CFA concentration on the particle size and size distribution were experimentally investigated. The as-prepared CFA nanoparticles were amorphous and exhibited a higher dissolution rate than raw CFA. This work suggests that microfluidics might find wide applications in the development and optimization of drug nanoparticles in the newly emerging field of nanomedicine.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201291r

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13799–13804

Titre :	Detrimental thixotropic thinning of filter cake of SiO2 – Al2O3 composite coated TiO2 particles and Its control
Type de document :	texte imprimé
Auteurs :	Bing-Xin Wei, Auteur ; Lin Zhao, Auteur ; Ting-Jie Wang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13799–13804
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Thixotropic
Résumé :	A SiO2–Al2O3 double layer coating process is widely used for TiO2 particle to reduce its photocatalytic activity. The conventional coating process needs a long time and uses large amounts of acid and alkali solutions. We recently developed a new SiO2–Al2O3 composite coating process that needs less time and does not use acid and alkali solutions. This process produced coated TiO2 particles with excellent weather durability, but it had the problem that the filter cakes composed of these particles were thixotropically thin and were easily broken up by shear or disturbance on a conveyor belt; that is, the cakes thinned into slurries very quickly. A slurry is not a suitable physical form for the subsequent drying process in industrial production. To understand this problem better, the rheology of the filter cakes was measured. Experiments to investigate the mechanism of the thixotropic thinning behavior indicated that the Si–O–H groups on the surface of the coated particles formed, by hydrogen bonding, a network structure of the particles that entrapped water within the structure. This structure was easily destroyed by an applied shear or disturbance, leading to the release of the occluded water, and the presence of water caused the cake to become a slurry and its viscosity to decrease sharply. This thixotropic thinning behavior of the filter cake was eliminated by coating the particle surface with a thin film of aluminum oxide.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201233u

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13789–13798

Titre :	Crystallization kinetics of linear and long - chain - branched polylactide
Type de document :	texte imprimé
Auteurs :	Mohammadreza Nofar, Auteur ; Wenli Zhu, Auteur ; Chul B. Park, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13789–13798
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Kinetics
Résumé :	In this study, the non-isothermal cold crystallization and isothermal melt crystallization of both linear and long-chain-branched (LCB) polylactide (PLA) were investigated using a differential scanning calorimeter (DSC). Talc was used as a nucleating agent to promote crystallization. The effects of chain branching on PLA’s cold crystallization kinetics at different heating rates and on PLA’s melt crystallization kinetics under different temperatures were studied by using Avrami analysis. The results showed that LCB-PLAs have faster cold and melt crystallization rates than those of linear PLA, since branched chains can play a role of nucleating site. Talc is a powerful nucleating agent, especially for linear PLA, either in cold crystallization or melt crystallization process. It was seen that addition of talc to PLA improves the crystallinity of PLA samples with more linear structure, more effectively because of its role of crystal nucleation. In PLA samples with more branched structure, talc has the least effect on crystallinity suggesting that the branched structure dominated crystallization already regardless of the presence of talc. Isothermal melt crystallization experimental results also showed that branched PLAs crystallized much faster than linear PLA and talc could increase the melt crystallization rate of linear PLA, but not that of PLA with a more branched structure.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie2011966

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13778–13788

Titre :	Selective Recovery of Valuable Components from Converter Steel Slag for Preparing Multidoped FePO4
Type de document :	texte imprimé
Auteurs :	Zhao-Jin Wu, Auteur ; Bei-Feng Jiang, Auteur ; Wei-Ming Liu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13778–13788
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Multidoped materials Lithium Ion Batteries
Résumé :	A novel route for preparing multidoped FePO4, an excellent starting material for synthesis of multidoped LiFePO4 cathode materials for lithium ion batteries, by using converter steel slag as raw material is proposed in this study. The processes included selectively reclaiming Fe, Mn, Cr, and P from the slag in the form of a ferroalloy through a carbothermic process, reacting the ferroalloy with phosphoric acid and hydrogen peroxide solution to produce a precursor, and calcining the precursor to finally obtain the single-phase multidoped FePO4. Effects of the pH value of the reactive system on the constituents and structures of products are determined by XRF, XRD, and SEM analysis. The single-phase hexagonal multidoped FePO4 doped with 1.5–3.3 atom % (Mn+Cr) was obtained at pH = 3.0–4.0, where the molar ratios of (Fe+Mn+Cr) to P were tested to be close to 1. About 80 wt % Fe and Cr in the slag could be recovered and directly turned into the multidoped FePO4, and the control on recovery rate of Mn could be performed by adjusting the pH value of the precipitation system according to constituent demand of the final product. The results indicate that a feasible route for utilizing converter steel slag as substitutes for chemical reagents to prepare multidoped FePO4 has been offered.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202255g

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13771–13777

Titre :	Synthesis and characterization of nanocrystalline PbTiO3
Type de document :	texte imprimé
Auteurs :	Mohamed Abd El-Fattah Gabal, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13771–13777
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Nanocrystalline
Résumé :	Nanocrystalline PbTiO3 in tetragonal form has been successfully prepared via a newly developed environmentally friendly coprecipitation process. The formation process of lead titanate from the PbC2O4·TiO2 precursor was monitored using DTA–TG, XRD, FT-IR, and TEM techniques. XRD showed the phase transition of less stable tetragonal PbO decomposition intermediate to a more stable orthorhombic structure by raising the calcination temperature. For the precursor calcined at 600 °C, only XRD lines characteristic of nanocrystalline tetragonal PbTiO3 are detected. TEM of PbTiO3 nanocrystals showed agglomerates with diameters in the range 85–90 nm. Consistent with the TEM result, the grain size estimated using surface area measurements indicated a high degree of particle agglomeration. FT-IR measurements gave results which are in close agreement with those revealed by XRD technique. The ac conductivity of PbTiO3 depends on the dielectric property. The kinetics of the nonisothermal TG curves for the precursor decomposition was carried out assuming various solid-state-reaction models and applying three different computational methods. The data analysis showed that the presence of TiO2 during oxalate decomposition reaction does not alter the decomposition mechanism; it drastically affects the activation parameter values.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie200988g

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13762-13770

Titre :	Size control of chitosan capsules containing insulin for oral drug delivery via a combined process of ionic gelation with electrohydrodynamic atomization
Type de document :	texte imprimé
Auteurs :	Sang-Yoon Kim, Auteur ; Hyunah Lee, Auteur ; Sungyeon Cho, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13762-13770
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Electrohydrodynamics Gelation Combined process
Résumé :	Recently, the development of new insulin delivery strategies, such as oral drug delivery, has sparked the interest of many researchers. In this paper, microsized chitosan capsules containing insulin were produced via a combined process of ionic gelation with electrohydrodynamic atomization (EHDA). Produced airborne chitosan―insulin droplets were reacted with phytic acid to induce the binding between chitosan and phytic acid, resulting in chitosan capsules containing insulin. As the nozzle size decreased, the size and uniformity of the primary airborne droplets decreased and enhanced, respectively. The size of primary airborne droplets affected the uniformity of the chitosan capsules in size. Using a nozzle of 320 μm in diameter, the mean diameter of the capsules was 232 μm, which is much smaller than that of capsules formed using only the ionic gelation method. The insulin encapsulation efficiency was nearly independent of nozzle size and was above 92%. Through in vitro tests, when a nozzle smaller than or equal to about 700 μm was used, the sustained insulin release occurred in the artificial intestinal juice although the smaller capsules exhibited lower resistance to acidic conditions.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299839

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13752-13761

Titre :	Release of Thyme Oil from Polylactide Microcapsules
Type de document :	texte imprimé
Auteurs :	Isabel M. Martins, Auteur ; Sofia N. Rodrigues, Auteur ; Maria F. Barreiro, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13752-13761
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Microcapsule
Résumé :	Microencapsulation reveals numerous advantages over conventional applications of flavors or fragances. Thus, the goal of this work was to study the release rate of thyme oil through the polylactide (PLA) microcapsules prepared by coacervation. Microcapsules have spherical shape and a mean particle size of 36 μm. The results show that the release of thymol is faster in the first hour and remains almost constant in the next days. Moreover, it was observed that the release of the polar compounds of thyme oil is faster than the apolar ones. The diffusion coefficient in the first hour of release was 1.39 × 10―15 m2/s for thymol and 5.21 × 10―17 m2/s for p-cymene. For a period of 5 drays, diffusion coefficients of 3.81 × 10―17M2/s for thymol and 1.43 x 10―18 m2/s for cymene were determined. The diffusion of thyme oil from the PLA cross-linked membrane was dependent on the microcapsules morphological characteristics.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299838

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13742–13751

Titre :	Design of molecular imprinted hydrogels for controlled release of cisplatin : evaluation of network density of hydrogels
Type de document :	texte imprimé
Auteurs :	Baljit Singh, Auteur ; N. Chauhan, Auteur ; Vikrant Sharma, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13742–13751
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Molecular hydrogels
Résumé :	In this era of new technologies, there is an ongoing interest in enhancing the efficiency of polymer-based drug delivery systems, and molecular imprinting technique has been suggested as one step in this direction. Therefore attempts have been made to design molecular imprinted polymers (MIPs) of HEMA and MAAc for the slow release of cisplatin. The characterization of network structure of hydrogels has been studied by FTIR, swelling studies, and determining the various structural parameters of hydrogel such as polymer volume fraction in the swollen state (2,s), Flory–Huggins interaction parameter (χ1), molecular weight of the polymer chain between two neighboring cross-links (M̅̅c), cross-link density(ρ), and the corresponding mesh size (ξ) by swelling equilibrium method. Effect of the cross-linker concentration on the network parameters has been studied along with influence of the network density on drug entrapment and release of drug from the hydrogel.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie200758b

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13732-13741

Titre :	Single - stage fischer – tropsch synthesis and hydroprocessing : the hydroprocessing performance of Ni / ZSM - 5 / γ - Al2O3 under fischer – tropsch conditions
Type de document :	texte imprimé
Auteurs :	Anier Freitez, Auteur ; Kyra Pabst, Auteur ; Bettina Kraushaar-Czarnetzki, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13732-13741
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Fischer Tropsch synthesis
Résumé :	The single-stage combination of Fischer―Tropsch synthesis and hydroprocessing without intermediate product fractionation has been studied using Co/Al2O3 as FT and Ni/ZSM-5/γ-Al2O3 as HP catalysts either in dual-layer arrangement or in physical mixture. Furthermore, the performance of the hydroprocessing catalyst under Fischer―Tropsch conditions was investigated in more detail in the gas phase hydroprocessing of n-dodecane in the presence of CO and H2O vapor, mimicking 69.4% Fischer-Tropsch conversion. All experiments were conducted at 10 bar and varying temperatures and residence times. In the gas phase hydroconversion of n-dodecane, CO and H2O showed a strongly inhibiting effect. The disturbance of the hydrogenation fimction by CO is most detrimental because enduring deactivation by coke formation is initiated. In combined single-stage experiments, the formation of a liquid hydrocarbon film in the FT reactions reduces the impact of the inhibitors to a large extent. Here, the hydroprocessing performance is mostly determined by the ratio H2/hydrocarbons. In both single-stage configurations, lower C numbers and larger isomer fractions as compared to the FT reference evidenced the activity of the HP catalyst. In physical mixture configuration, however, the HP catalyst benefits from the higher H2/hydrocarbon ratios along the complete catalyst bed, resulting in a more efficient reduction of C21+ hydrocarbons and high isomer fractions in a broader range of carbon numbers.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299836

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13727-13731

Titre :	Nonisothermal decomposition kinetics of abietic acid in argon atmosphere
Type de document :	texte imprimé
Auteurs :	Weijian Nong, Auteur ; Xiaopeng Chen, Auteur ; Linlin Wang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13727-13731
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Kinetics
Résumé :	Abietic acid was isolated from rosin by means of reaction-crystallization coupled with exposure to ultrasonic waves, and it was then characterized by its specific rotation, infrared spectra, and 13C nuclear magnetic resonance spectra. The thermal decomposition of abietic acid in argon atmosphere was studied under nonisothermal conditions using TG-DTG techniques with beating rates of 5,10,20, and 25 K/min. For the kinetic study, the nonisothermal kinetic parameters were obtained via the analysis of the TG-DTG curves by using the Flynn-Wall-Ozawa (FWO) method, the Kissinger method, and the integral method. The results showed that the nonisothermal decomposition mechanism of abietic acid in argon atmosphere followed Mampel Power law with n = 3/2, whose differential and integral forms were f(α)=2/3α―1/2 and G(α) α3/2. The apparent activation energy Ea and the pre-exponential factor A were 123.44 kJ/mol and 1.78 × 1011 s―1, respectively. The kinetic equation can be expressed as da/dt=1.19 x 1011 α―1/2 exp(―1.48 x 104/T). The thermodynamic parameters (ΔH‡, ΔG‡, and ΔS‡) were calculated as well.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299835

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13717–13726

Titre :	Synthesis, characterization, and catalytic performance of highly dispersed supported nickel catalysts from Ni – Al layered double hydroxides
Type de document :	texte imprimé
Auteurs :	Jia Wang, Auteur ; Guoli Fan, Auteur ; Hui Wang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13717–13726
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Catalysts Hydroxides
Résumé :	Highly dispersed nickel nanoparticles were successfully prepared by reduction of Ni–Al layered double hydroxide precursor (NiAl-LDH) supported on nitric acid modified carbon nanotubes (HCNTs). The physicochemical properties of materials were investigated by powder X-ray diffraction (XRD), temperature programmed reduction (TPR), temperature programmed decomposition (TPDE), temperature programmed desorption (TPD), transmission electron microscopy (TEM), low-temperature nitrogen adsorption–desorption experiments, and X-ray photoelectron spectroscopy (XPS). The results revealed that in the synthesis process of NiAl-LDH and HCNTs composite, l-cysteine could improve the attachment of NiAl-LDH on the HCNTs as bridging linker and inhibit the growth of NiAl-LDH crystallites, thus leading to the formation of highly dispersed and uniform Ni nanoparticles with the small particle sizes. Compared with HCNTs-supported Ni catalyst prepared without the addition of l-cysteine, this highly dispersed Ni catalyst exhibited enhanced catalytic performance in liquid phase hydrogenation of o-chloronitrobenzene to o-chloroaniline.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie2015087

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13711-13716

Titre :	Cysteine - based organocatalysts for the highly efficient direct stoichiometric anti - and syn - aldol reactions
Type de document :	texte imprimé
Auteurs :	Shi Li, Auteur ; Chuanlong Wu, Auteur ; Xiangkai Fu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13711-13716
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Organocatalysts Stoichiometric
Résumé :	A series of cysteine-based organocatalysts have been designed and synthesized from a simple step. The anti-aldol and syn-aldol products could be obtained with up to 98:2 anti/syn and 99% ee; the stoichiometric ratio between aldehydes and ketones is 1. This catalyst could be easily recovered and efficiently used in large-scale reactions, which demonstrates its potential application in industry.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201482c

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13703–13710

Titre :	Formulation of Reaction Kinetics for Cyclohexanone Ammoximation Catalyzed by a Clay-Based Titanium Silicalite-1 Composite in a Semibatch Process
Type de document :	texte imprimé
Auteurs :	Alex C. K. Yip, Auteur ; Xijun Hu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13703–13710
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Kinetics
Résumé :	This article focuses on the kinetic modeling of cyclohexanone ammoximation catalyzed by the clay-based titanium silicalite-1 (TS-1) composite. With the use of computational tools, modeling was carried out systematically, and a rational interpretation of the reaction mechanism was successfully achieved. By fitting the experimental and calculated data, it was found that cyclohexanone ammoximation over the clay-based TS-1 composite follows the Eley–Rideal mechanism in which the reaction takes place between adsorbed H2O2 and other reactants in the free state. It is concluded that a full understanding of the mechanism and kinetics of the reaction allows one to engineer the overall cyclohexanone ammoximation process by influencing elementary steps. The pre-exponential factor and activation energy of the reaction were also determined as a reference for industrial reactor design.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201467u

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13693–13702

Titre :	Synthesis and Characterization of 12-Tungstosilicic Acid Anchored to MCM-41 as well as Its Use as Environmentally Benign Catalyst for Synthesis of Succinate and Malonate Diesters
Type de document :	texte imprimé
Auteurs :	Varsha Brahmkhatri, Auteur ; Anjali Patel, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13693–13702
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Tungstosilicic acid Catalyst
Résumé :	12-Tungstosilisic acid anchored to MCM-41 was synthesized and characterized by various physicochemical techniques such as thermogravimetric analysis (TGA), Fourier transform infrared (FT-IR), laser-Raman spectroscopy, diffuse reflectance spectroscopy (DRS), N2 adsorption–desorption, 29Si-magic-angle spinning (MAS) NMR, X-ray diffraction (XRD), scanning electron microscopy (SEM), and transmission electron microscopy (TEM). The total acidity was determined by n-butyl amine titration. The types of acidic sites (acidic strength) were determined by potentiometric titration. The use of synthesized material was explored for esterification of diacarboxylic acids with butanol. Influence of various reaction parameters (catalyst concentration, acid/alcohol molar ratio and reaction time) on catalytic performance was studied. The catalyst shows high activity in terms of higher yields toward diesters, especially for dioctyl succinate and dioctyl malonate. The catalyst was also regenerated and reused for four cycles. All these characteristics imply the high potential of an environmentally benign catalyst for synthesis of succinate and malonate diesters.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201447y

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13686-13692

Titre :	Catalytic oxidative desulfurization of gasoline using ionic liquid emulsion system
Type de document :	texte imprimé
Auteurs :	Jianhua Ge, Auteur ; Yuming Zhou, Auteur ; Yong Yang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13686-13692
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Emulsion Ionic liquid Desulfurization Oxidation Catalytic reaction
Résumé :	With the aim of deep desulfurization of the gasoline, an amphiphilic catalyst, which is composed of lacunary anion [PW11O39]7- and quaternary ammonium cation [C18H37(CH3)3]N+, assembled in hydrophobic ionic liquid emulsions, can oxidize the sulfur compounds present in oil into their corresponding sulfones under ambient reaction conditions. In this process, catalytic oxidation of sulfur-containing molecules in model oil was investigated in detail under different reaction conditions (including different desulfurization systems, H2O2/DBT molar ratio, temperature, and various sulfur compounds). Moreover; this ionic liquid emulsion system could be recycled five times with an unnoticeable decrease in catalytic activity, and, from the kinetics study, it can be shown that the catalytic oxidative reaction is a pseudofirst-order reaction and the half-life is 30.4 min. Furthermore, the mechanism of catalytic oxidation desulfurization was elaborated, and the total sulfur level of real gasoline can be decreased from 1236 to 65 ppm after catalytic oxidation using an ionic liquid emulsion system.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299830

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13672–13685

Titre :	Comprehensive CFD Simulation of Product Yields and Coking Rates for a Floor- and Wall-Fired Naphtha Cracking Furnace
Type de document :	texte imprimé
Auteurs :	Guihua Hu, Auteur ; Honggang Wang, Auteur ; Feng Qian, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13672–13685
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Industrial naphtha furnace
Résumé :	A coupled furnace/reactor simulation was conducted to determine product yields and coking rates for an industrial SL-II naphtha cracking furnace fired by both floor and wall burners. The process gas side, as well as the fire side, is simulated using the computational fluid dynamics (CFD) approach. The molecular kinetic model of Kumar and co-workers was used to simulate the naphtha cracking reactions in the reactor. The results show that the asymmetrical design of the furnace results in asymmetrical profiles of flue gas velocity, temperature, and concentration, and leads to poor heat supply of the wall burners on the front wall as well as a high-temperature zone in the crossover section. The recirculation of flue gas caused by the positioning of burners makes the temperature more uniform in the middle of the furnace. Good agreement between simulation and industrial product yields has been obtained without any tuning of the kinetics, indicating that the proposed approach can be used as a guide for further optimization of geometries and operating parameters of naphtha cracking furnaces with burners located both in the floor and in the wall. The coking rate profile reveals that the maximum coking rate is not located at the coil outlet or near the last reactor bend, but rather at a height of 7 m in the second reactor pass.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie2012642

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13662-13671

Titre :	Hydrogen production via sorption enhanced steam methane reforming process using Ni / CaO multifunctional catalyst
Type de document :	texte imprimé
Auteurs :	Naruewan Chanburanasiri, Auteur ; Ana M. Ribeiro, Auteur ; Alirio E. Rodrigues, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13662-13671
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Catalyst Reforming Water vapor Sorption Hydrogen production
Résumé :	Sorption enhanced steam methane reforming (SESMR) is a promising concept for hydrogen production. The in situ removal of CO2 shifts the reaction equilibrium toward increased H2 production as well as H2 concentration. Generally, most of the previous studies operated the SESMR system using separate materials of a CO2 adsorbent and a reforming catalyst. In this study, a combined catalyst-adsorbent material (considered as multifunctional catalyst), whose functions are not only to catalyze the reaction but also to adsorb CO2 simultaneously, was developed and utilized for the SESMR process. CaO and hydrotalcite (MK30-K), well-known adsorbents for CO2 capture, were selected as supports to replace a conventional Al2O3 support for Ni catalyst. The material was prepared in the form of powder by incipient wetness technique, and the tests were carried out in the fixed bed reactor system. Experimental results indicated that the activity of Ni/CaO was less than Ni/Al2O3 but high hydrogen concentration in the product stream can be achieved. The effect of Ni loading was investigated, and it was found that at atmospheric pressure, steam to methane ratio of 3 and T = 873 K, 12.5 wt % Ni/CaO was the appropriate ratio, offering high hydrogen concentration (80%). The study also suggested that the use of the multifunctional catalyst eliminates the use of Al2O3 and thus requires a reactor with a smaller size.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299828

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13655–13661

Titre :	Kinetics of CO2 stripping and its effect on the saturation state of CaCO3 upon aeration of a CaCO3 – CO 2 – H2O system : application to scaling in the papermaking process
Type de document :	texte imprimé
Auteurs :	Patrick Huber, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13655–13661
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Kinetics Papermaking process
Résumé :	Calcium carbonate scaling is a critical problem in papermills. It often has been observed that scaling occurs in aerated sections of the process, where CO2 stripping from the solution is responsible for the saturation increase with respect to CaCO3. To better cope with scaling problems, it is important to be able to predict both supersaturation levels after aeration and the rate at which the system becomes supersaturated. In this study, trials are performed on a bubble column. Air is bubbled to strip out the dissolved CO2 from a CaCO3–CO2–H2O system. The saturation kinetics with respect to CaCO3 are followed by recording pH, and analyzed by speciation calculations. Aeration conditions are determined through gas hold-up and bubble size measurements. A general kinetic model is proposed to estimate how fast a solution will become saturated with respect to calcium carbonate during aeration. The model is applied to water quality and aeration conditions typically encountered in some unit operations of the papermaking process. Knowing the rate of change of calcium carbonate saturation will help papermakers to better estimate scaling risk in their process, and will help equipment suppliers to either minimize scaling problems in aerated sections of the process or design aeration units for calcium carbonate removal by controlled precipitation.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie200956z

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13650–13654

Titre :	Environmentally friendly efficient one - pot electrochemical synthesis of 2,4 - dimethylanisole by selective oxidation of m - xylene in methanol with metals promoted sulfated zirconia
Type de document :	texte imprimé
Auteurs :	Fengtao Chen, Auteur ; Sanchuan Yu, Auteur ; Xiaoping Dong, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13650–13654
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Electrochemical Oxidation Methanol
Résumé :	Herein, we reported the efficiently catalytic synthesis of 2,4-dimethylanisole with electrochemically selective oxidation of m-xylene in methanol under mild conditions. The catalysts of SO42–/M–ZrO2 (M = Mo, Cu, Fe, Co, and Cr), prepared by coprecipitation and postsynthesized sulfation, were characterized by means of Fourier transform infrared (FT-IR) spectroscopy and powder X-ray diffraction (XRD), which indicated that the modification of sulfates and the incorporation of metal ions would not influence the structure of zirconia and the doped metal ions were well dispersed. The electrochemical reaction process was monitored by UV–vis spectroscopy, and the distribution of the products was analyzed by gas chromatography–mass spectrometry (GC–MS). All catalysts exhibited excellent activity for the electrochemical reaction assisted by a pair of porous graphite plane electrodes. X-ray photoelectron spectroscopy (XPS) showed a mixture of Zr2+ and Zr4+ in the catalysts after the reaction, demonstrating the participation of catalyst in this redox reaction. The results revealed that a maximum yield of about 62.1% was achieved for 2,4-dimethylanisole in the SO42–/Mo–ZrO2 reaction system in 3 h. This method provides a new environmentally benign and simple way to synthesize 2,4-dimethylanisole.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie200740p

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13642–13649

Titre :	Gold nanoparticles intercalated into the walls of mesoporous silica as a versatile redox catalyst
Type de document :	texte imprimé
Auteurs :	Lifang Chen, Auteur ; Juncheng Hu, Auteur ; Zhiwen Qi, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13642–13649
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Nanoparticles Mesoporous Silica
Résumé :	A nanoscaled reactor framework of well-dispersed gold particles intercalated into the walls of mesoporous silica (GMS) was prepared by functionalizing silica with thioether groups. The GMS maintains mesoporous structure with uniform pores of 5.6 nm and possesses high surface area of more than 800 m2·g–1. Very recently, we reported that the GMS catalyst was very active for the oxidation of alkanes and alcohols but was also durable and recyclable. Here, we show that the catalyst is also very active for the reduction of p-nitrophenol (PNP) and methylene blue (MB) displaying catalytic activity in the reduction of PNP with Knor-PNP of 45.9 mmol–1·s–1. The unobstructed ordered mesoporous structure of the GMS catalyst and the small size of gold nanoparticles are the main factors leading to high catalytic activities. Further, for reduction of MB, the catalytic rate of the catalyst decreases by less than 6% when recycled 10 times. Therefore, the nanoreactor framework catalyst is very robust and is readily separable and reusable, demonstrating attractive potential for practical applications.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie200606t

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13636–13641

Titre :	Direct synthesis of dimethyl toluene - 2,4 - dicarbamate from 2,4 - toluene diamine, urea, and methanol
Type de document :	texte imprimé
Auteurs :	Xinqiang Zhao, Auteur ; Na Wang, Auteur ; Yanlou Geng, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13636–13641
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Dimethyl Toluene Dicarbamate
Résumé :	Dimethyl toluene-2,4-dicarbamate (TDC) was directly synthesized from 2,4-toluene diamine (TDA), urea, and methanol in order to overcome the drawbacks of other technological routes to TDC. First the thermodynamic analysis for this reaction was made and the results show that the reaction is endothermic and can occur spontaneously beyond 413.8 K. Then the effects of catalyst and reaction conditions were studied. TDA conversion of 98.8% and TDC selectivity of 41.6% were attained in the presence of zinc chloride catalyst and under the suitable conditions of molar ratio of TDA/zinc chloride/urea/methanol = 1/0.07/5/80, reaction temperature of 190 °C, reaction pressure of 3.0 MPa, and reaction time of 9 h. Low TDC selectivity is attributed to the difficulty in the conversion of the intermediates, methyl 2-methyl-5-amino N-phenylcarbamate (TMC1) and methyl 3-amino-4-methyl-N-phenylcarbamate (TMC2), to TDC. Finally on the basis of analyses of HPLC–MS, HPLC, and GC, three possible reaction paths were proposed. One path is the reaction of TDA with urea to toluene-2,4-bisurea (TBU) and then the formation of TDC from the succeeding reaction of TBU with methanol. Another path is the generation of TMC1 and TMC2 from the reaction of TDA with first urea and then methanol, and the succeeding reaction of the formed TMC1 and TMC2 with first urea and then methanol to TDC. Still another path is the formation of methyl carbamate (MC) by the reaction of urea and methanol and then the reaction of TDA with MC to TMC1 and TMC2, and finally a further reaction of TMC1 and TMC2 with MC to TDC.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201891p

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13628-13635

Titre :	Schiff base ligands immobilized on a nanosized SiO2 – Al2O3 mixed oxide as adsorbents for heavy metals
Type de document :	texte imprimé
Auteurs :	Mohammad Arshadi, Auteur ; Mehran Ghiaci, Auteur ; Antonio Gil, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13628-13635
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Heavy metal Ligand
Résumé :	Three adsorbents have been synthesized by immobilization of Schiff base ligands on the surface of SiO2―Al2O3 mixed oxides and evaluated for the removal of Cd(II) and Pb(II) from aqueous solutions. The contact time to attain equilibrium for maximum adsorption was 120 min. These heterogeneous Schiffbase ligands were found to be effective adsorbents for the removal of heavy metal ions from solution, with Si/Al-pr-N=salicylaldehyde having a high adsorption capacity for Cd(II) ions and Si/Al-pr-N=pyridine-2-carbaldehyde having a high adsorption capacity for Pb(II) ions. The adsorption of heavy metal ions has been studied in terms of pseudo-first-order and pseudo-second-order kinetics, and the Freundlich, Langmuir, and Langmuir—Freundlich isotherm models have also been applied to the equilibrium adsorption data.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299823

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13620-13627

Titre :	Design and performance evaluation of ionic - liquids - based microwave - assisted environmentally friendly extraction technique for camptothecin and 10 - hydroxycamptothecin from samara of camptotheca acuminata
Type de document :	texte imprimé
Auteurs :	Shu-ya Wang, Auteur ; Lei Yang, Auteur ; Yuan-gang Zu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13620-13627
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Microwave Ionic liquid Design
Résumé :	Ionic-liquids-based, microwave-assisted extraction (ILMAE) was successfully applied to the extraction of two alkaloids: camptothecin (CPT) and 10-hydroxycamptothecin (HCPT) from samara of Camptotheca acuminata. Ten different types of 1-alkyl-3-methylimidazolium, with different cations and anions, were investigated in this work, and 1-hexyl-3-methylimidazolium bromide ([C8MIM]Br) solution was selected as the optimal solvent. In addition, the extraction parameters, including ionic liquid concentration, soak time, microwave irradiation power, irradiation time, solid—liquid ratio, and number of extraction cycles, were optimized. The optimal conditions were as follows: 0.8 M [C8MIM]Br; soak time, 2 h; microwave irradiation power, 385 W; irradiation time, 8 min; solid-liquid ratio, 1:12 (g/mL); and two of extraction cycles. No degradation of the target analytes have been observed at the optimum conditions, as evidenced from the stability studies performed with standard CPT and HCPT. The proposed method also shows high reproducibility. Compared with the traditional methods, the proposed approach demonstrates higher efficiency in a shorter extraction time (from 4 h to 8 min), which demonstrates that ILMAE is a rapid, efficient, and simple sample extraction technique.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25299822

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13614–13619

Titre :	Versatile and scalable method for producing N - functionalized imidazoles
Type de document :	texte imprimé
Auteurs :	Jason E. Bara, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13614–13619
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Sodium imidazolate
Résumé :	Imidazolate salts are powerful and versatile starting materials that can be used to generate many useful compounds. To this end, a method for producing sodium imidazolate (NaIm) from only commodity starting materials has been developed. NaIm was directly produced at a scale of 400 g via the neutralization of molten imidazole by NaOH, followed by dehydration. The NaIm product was then utilized as a starting material to produce 20 different N-functionalized imidazole and bis(imidazole) compounds, with the application of a common procedure involving minimal solvent volumes and straightforward purification via flash chromatography and solvent evaporation. Generating N-functionalized imidazoles “on demand” from NaIm and alkyl halides (or similar compounds) can eliminate the need for hazardous starting materials such as NaH and anhydrous solvents that have typically been employed in their synthesis. This method may ultimately enhance the availability of N-functionalized imidazoles for a variety of research and commercial applications.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie102535c

[article]
in Industrial & engineering chemistry research > Vol. 50 N° 24 (Décembre 2011) . - pp. 13589–13613

Titre :	Rice husk and its ash as low - cost adsorbents in water and wastewater treatment
Type de document :	texte imprimé
Auteurs :	M. Ahmaruzzaman, Auteur ; Vinod K. Gupta, Auteur
Année de publication :	2012
Article en page(s) :	pp. 13589–13613
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Adsorbents Water Wastewater treatment
Résumé :	Rice husk, which is a relatively abundant and inexpensive material, is currently being investigated as an adsorbent for the removal of various pollutants from water and wastewaters. Various pollutants, such as dyes, phenols, organic compounds, pesticides, inorganic anions, and heavy metals can be removed very effectively with rice husk as an adsorbent. This article presents a brief review on the role of rice husk and rice husk ash in the removal of various pollutants from wastewater. Studies on the adsorption of various pollutants by rice husk materials are reviewed and the adsorption mechanism, influencing factors, favorable conditions, etc., discussed in this article. It is evident from the review that rice husk and its ash can be potentially utilized for the removal of various pollutants from water and wastewaters.
DEWEY :	660
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201477c

Industrial & engineering chemistry research / Paul, Donald R. . Vol. 50 N° 24

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