Catalogue en ligne Bibliothèque Ecole Nationale Polytechnique d'Alger

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10746–10750

Titre :	Determination of effective diffusion coefficients through the walls of coated diesel particulate filters
Type de document :	texte imprimé
Auteurs :	Oliver Krocher, Auteur ; Martin Elsener, Auteur ; Martin Votsmeier, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10746–10750
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Determination--Effective--Diffusion--Coefficients--through--Walls--Coated Diesel--Particulate Filters
Résumé :	We demonstrate in this paper that the effective diffusion coefficient in the wall of a particulate filter can be determined by measuring the diffusion of NO between two adjacent channels of a filter segment in a simple apparatus based on a modified experimental method of Beeckman. The effective diffusion coefficient in the walls of an uncoated SiC particulate filter is determined as 2.8 × 10−6 m2/s at room temperature. Coating the filter with 30 or 65 g/L of wall-integrated washcoat leads to an insignificant increase in the diffusion coefficient, whereas coating the same filter with a high washcoat loading of 140 g/L leads to a decrease of the diffusion coefficient to 2.0 × 10−6 m2/s. All of the determined diffusion coefficients increase with temperature proportional to T1.5. This indicates that the diffusion in the wall is mainly molecular diffusion and that Knudsen diffusion plays a minor role. Fitting the parallel pore model to the experimental diffusion coefficient of the uncoated filter results in a tortuosity factor of 3.5. The random pore model overpredicts the effective diffusion coefficient by almost 50%. Neither of the two models reproduces the threshold-type dependency of the effective diffusion coefficient on washcoat loading. However, all experimental results are predicted by both pore models with an accuracy of better than 50%, so that an estimation of the effective diffusion coefficient might be a feasible solution for many practical simulation tasks.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901269v

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10740–10745

Titre :	Estimating crystal growth rates using in situ ATR-FTIR and raman spectroscopy in a calibration-free manner
Type de document :	texte imprimé
Auteurs :	Jeroen Cornel, Auteur ; Mazzotti, Marco, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10740–10745
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Estimating--Crystal--Growth--Rates--Using--situ ATR-FTIR--Raman--Spectroscopy-- Calibration-Free Manner
Résumé :	Seeded batch desupersaturation experiments of paracetamol in water were monitored using in situ ATR-FTIR and in situ Raman spectroscopy. On the basis of the linear relationship between the measured signal and the concentrations of the involved components, in situ ATR-FTIR and Raman spectroscopy could be used quantitatively in a calibration-free manner to estimate the crystal growth rate of paracetamol. Using a population balance model and a nonlinear least-squares optimization routine, it was shown that by fitting the measured time-resolved ATR-FTIR spectra directly and by fitting the desupersaturation profiles obtained from these spectra combined with a previously developed calibration model, essentially the same growth rate parameters can be estimated. Very similar growth rate parameters could be obtained by fitting the measured time-resolved Raman spectra using the same population balance model. These results show that crystal growth rates can be estimated in a calibration-free manner using both in situ spectroscopic techniques, thereby avoiding lengthy calibration procedures.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9008138

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10734–10739

Titre :	Investigation of bulk and interfacial properties for nitrogen and light hydrocarbon binary mixtures by perturbed-chain statistical associating fluid theory combined with density-gradient theory
Type de document :	texte imprimé
Auteurs :	SongTao Liu, Auteur ; Dong Fu, Auteur ; JianYi Lu, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10734–10739
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Investigation--Bulk--Interfacial--Properties--Nitrogen-- Hydrocarbon--Binary--Mixtures--Perturbed-Chain--Statistical--Associating--Fluid Theory--Combined--Density-Gradient
Résumé :	The perturbed-chain statistical associating fluid theory (PC-SAFT) and density-gradient theory (DGT) are used to construct an equation of state (EOS) for the phase behavior of the binary mixtures of nitrogen and light hydrocarbons. With the molecular parameters and influence parameters respectively regressed from bulk properties and surface tensions of pure fluids as input, both the bulk and the interfacial properties for binary mixtures are investigated. The calculated surface tensions of nitrogen−pentane, nitrogen−hexane, nitrogen−heptane, nitrogen−octane, nitrogen−decane, and nitrogen−toluene binary mixtures are satisfactory as compared to the experimental data. Our results show that PC-SAFT combined with DGT is able to describe the interfacial properties of the binary mixtures of nitrogen−light hydrocarbons in wide pressure range and illustrate the influences of temperature, pressure, and bulk properties on the interfacial properties.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9007437

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10728–10733

Titre :	Thermodynamic analysis on the mineralization of trace organic contaminants with oxidants in advanced oxidation processes
Type de document :	texte imprimé
Auteurs :	Yuanhui Ji, Auteur ; Zhuhong Yang, Auteur ; Xiaoyan Ji, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10728–10733
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Thermodynamic--Analysis--Mineralization--Trace Organic--Contaminants--Oxidants--Advanced--Oxidation--Processes
Résumé :	There is a growing demand for the efficient treatment of organic polluted wastewaters by advanced oxidation processes (AOPs) which calls for the determination of the mineralization order of ease for the organic contaminants with oxidants. The mineralization abilities of organic contaminants in AOPs are investigated in this work. Photocatalytic experiments for three representative organic contaminants are carried out, and their corresponding reaction rates are determined experimentally. Meanwhile, molar Gibbs free energy changes ΔrGm° for the reactions of 31 organic contaminants (10 chlorinated hydrocarbons, four brominated hydrocarbons, 11 aromatic hydrocarbons and their derivatives, three chloroacetic acid, and three chloroacetyl chloride) with oxidants of •OH, H2O2, •O−, O3, and O2 are calculated, and the mineralization order of ease is determined theoretically on the basis of ΔrGm°. The agreement of the theoretical and experimental mineralization abilities for most of the organic contaminants investigated implies the reliability of the determination of the mineralization ability from the magnitude of ΔrGm° for the mineralization of trace organic contaminants. Results also show that for most of the organic contaminants studied, the mineralization abilities are •OH > H2O2 > •O− > O3 > O2, and the mineralization ability of the organic contaminants depends on not only the oxidants but also the structure and properties of the organic contaminants themselves, and the degradation reaction products.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900620n

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10718–10727

Titre :	Multistage fluidized bed reactor performance characterization for adsorption of carbon dioxide
Type de document :	texte imprimé
Auteurs :	Sudeshna Roy, Auteur ; C. R. Mohanty, Auteur ; B. C. Meikap, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10718–10727
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Multistage--Fluidized--Reactor Performance--Characterization--Adsorption--Carbon Dioxide
Résumé :	Carbon dioxide and its different compounds are generated as primary greenhouse gases from the flue gases of coal-fired thermal power plants, boilers, and other stationary combustion processes. This greenhouse gas causes global warming after being emitted to the environment. To deal with this problem, a new dry scrubbing process was tested in this study. A three-stage countercurrent fluidized bed adsorber was developed, designed, and fabricated. It was used as a removal apparatus and operated in a continuous regime for the two-phase system. The height of each stage was 0.30 m, and the inner diameter was 0.10 m. The paper presents the removal of CO2 from gas mixtures by chemical sorption on porous granular calcium oxide particles in the reactor at ambient temperature. The advantages of a multistage fluidized bed reactor for high mass transfer and high gas−solid contact can enhance the removal of the gas when using a dry method. The effects of the operating parameters such as sorbent, superficial gas velocity, and the Weir height on CO2 removal efficiency in the multistage fluidized bed were investigated. The results indicate that the removal efficiency of the carbon dioxide was around 71% at a high solid flow rate corresponding to lower gas velocity at room temperature. In comparison with wet scrubbers, this dry process appears to have lower cost, less complicated configuration, and simpler disposal of used sorbent. The results in this study assume importance from the perspective of use of a multistage fluidized bed adsorber for control of gaseous pollutants at high temperature.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901133r

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10708–10717

Titre :	Generalized cubic equation of state adjusted to the virial coefficients of real gases and its prediction of auxiliary thermodynamic properties
Type de document :	texte imprimé
Auteurs :	Ilya Polishuk, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10708–10717
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Generalized--Cubic Equation--Adjusted--Virial Coefficients--Real Gases--Prediction--Auxiliary--Thermodynamic--Properties
Résumé :	This study demonstrates that the overall reliability of a simplest cubic equation of state (EOS) might be improved by developing its accuracy in estimating the virial coefficients. In particular, it has been demonstrated that the progress can be achieved in predicting the sound velocities and, probably, the Joule−Thomson inversion curves. At the same time, the limitations of the simplest model are evident. In particular, it fails in predicting of the virial coefficients in the low temperature range. As a result, its predictions of the liquid phase properties are still imperfect. Further directions of development of the proposed EOS are discussed.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900905p

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10702–10707

Titre :	Comparison of mercury retention by fly ashes using different experimental devices
Type de document :	texte imprimé
Auteurs :	M. Antonia López-Antón, Auteur ; Patricia Abad-Valle, Auteur ; Mercedes Díaz-Somoano, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10702–10707
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Comparison--Mercury Retention--Fly Ashes--Using--Different--Experimental--Devices
Résumé :	To study mercury (Hg) retention in solid sorbents, researchers generally employ similar laboratory-scale devices. However, despite their similarities, these devices are generally used under different experimental conditions. The Hg concentration in the gas phase, gas flow, and sorbent-bed characteristics are variables that influence the contact time, mass transfer, and kinetics and may greatly modify the quantities of Hg retained when the same sorbents are compared. These differences in the experimental conditions do not impede an evaluation of the sorbents as long as the results obtained points toward the same qualitative conclusions. However, the extent of variation needs to be defined to avoid misinterpretation. To illustrate the range of interpretations, the results of a preliminary approach using four experimental devices in two laboratories have been compared in this work. All the experiments were carried out under a nitrogen atmosphere and Hg0 in the gas phase. The same sorbents were employed in all the devices. These were fly ashes obtained from the combustion of coals of different rank and with different unburned carbon contents. From the results obtained it can be inferred that it is necessary to strictly control the influence of the experimental variables to infer a correct interpretation of the results.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900766y

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10691–10701

Titre :	Pilot-scale gasification of corn stover, switchgrass, wheat straw, and wood : 2. identification of global chemistry using multivariate curve resolution techniques
Type de document :	texte imprimé
Auteurs :	Whitney Jablonski, Auteur ; Katherine R. Gaston, Auteur ; Mark R. Nimlos, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10691–10701
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Pilot-Scale--Gasification--Corn Stover--Switchgrass--Wheat Straw--Wood--Identification--Global Chemistry--Using Multivariate--Curve Resolution--Techniques
Résumé :	A pilot-scale study was conducted to examine the effect of the steam-to-biomass ratio, the gasification temperature, and the thermal cracker temperature for Vermont wood, wheat straw, switchgrass, and corn stover on the formation and speciation of tars. This study is divided into two parts; the first paper detailed the processing conditions and gives quantitative information on low-molecular-weight species. This paper, which is the second part of this study, uses multivariate curve resolution techniques to correlate process variables with the mass spectra gathered during the study to (1) identify the global chemistry of the system and (2) to identify differences or similarities of the product gas streams for each feedstock. Three main groups of products were identified statistically: (1) primary and secondary pyrolysis products (e.g., guaiacol, furfural), (2) cracking products (e.g., phenol, cresol), and (3) polynuclear aromatic hydrocarbons (PAHs). Our findings support known global reaction mechanisms that delineate the formation of the more-refractory PAHs, whereby oxygenated pyrolysis products are cracked into smaller fragments that contain less oxygen. These crack further into small hydrocarbons and radicals that undergo molecular weight growth to produce PAHs. The results from this statistical analysis indicate that, at high temperatures, where PAHs dominate, there is little variation observed between the feedstocks.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900596v

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10682–10690

Titre :	Characteristics and precipitation of glucose oligomers in the fresh liquid products obtained from the hydrolysis of cellulose in hot-compressed water
Type de document :	texte imprimé
Auteurs :	Yun Yu, Auteur ; Hongwei Wu, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10682–10690
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Characteristics--Precipitation--Glucose--Oligomers--Fresh Liquid--Products--Obtained--Hydrolysis--Cellulose--Hot-Compressed--Water
Résumé :	Using a high-performance anion exchange chromatography with pulsed amperometric detection (HPAEC-PAD), this study shows the presence of a wide range of glucose oligomers with the degrees of polymerization (DPs) up to 30 and their derivatives in the fresh liquid products produced from cellulose hydrolysis in hot-compressed water (HCW) using a semicontinuous reactor system at 280 °C and 20 MPa. None of those oligomers can be detected by a high-performance liquid chromatography with evaporative light scattering detector (HPLC-ELSD) that however can detect glucose oligomers with DPs up to 6 after the liquid solutions are concentrated by 25 times via vacuum evaporation at 40 °C, during which a large amount of precipitate is formed. While quantitative analysis of the glucose oligomers with DPs > 5 cannot be done due to the lack of standards, that of the glucose oligomers from glucose (DP = 1) to cellopentaose (DP = 5) using both HPAEC-PAD and HPLC-ELSD are in good agreement, suggesting that these low-DP glucose oligomers do not contribute to the precipitate formation. Results from a set of purposely designed precipitation experiments indicate that the precipitation starts as the fresh liquid sample is collected and is fast during the initial 8 h, levels off as the precipitation time increases further, and completes after 120 h (5 days). On the basis of a new approach developed for the quantification of glucose oligomer retention during the precipitation process, it is found that the contribution of glucose oligomers to precipitate formation increases with DP. The higher the DP is, the lower the solubility of the glucose oligomer is. The glucose oligomers from glucose to cellopentaose and their derivatives (DPs = 1−5) contribute little to the precipitate formation, which explains why HPLC-ELSD can correctly analyze these glucose oligomers in the concentrated solutions prepared by vacuum evaporation. The glucose oligomers and their derivatives with DP > 5, which are soluble in HCW but become supersaturated in the solutions under ambient conditions, are responsible for precipitate formation. Most (but not all) of the glucose oligomers and their derivatives with DPs > 16 contribute to the precipitate formation as tiny peaks of these glucose oligomers are still shown in the chromatograms, suggesting that these glucose oligomers have very low (but nonzero) solubilities in ambient water. The retentions of glucose oligomers and their derivatives increase substantially with the DP decreasing from 16 to 6, indicating that less of these lower-DP oligomers contribute to the precipitate formation. To avoid the effect of precipitation on oligomer analysis, the fresh liquid products must be analyzed immediately after sample collection.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900768m

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10664–10681

Titre :	The Modified Sanchez−Lacombe Equation of State Applied to Polydisperse Polyethylene Solutions
Type de document :	texte imprimé
Auteurs :	Ryan A. Krenz, Auteur ; Torben Laursen, Auteur ; Robert A. Heidemann, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10664–10681
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Modified--Sanchez−Lacombe--Equation--Applied--Polydisperse--Polyethylene--Solutions
Résumé :	The modified Sanchez−Lacombe equation of state (MSL-EOS) is Neau’s version of the Sanchez−Lacombe equation of state modified to include a Péneloux-type volume translation. The purpose of this work is to report parameters for modeling the phase behavior of polyethylene solutions. The MSL equation is an empirical equation that contains four parameters to define each pure compound whether a solvent or a polydisperse polymer. The MSL equation uses conventional linear and quadratic mixing rules. A parametrization can be used to obtain the pure compound parameters from the molar mass, critical temperature, critical pressure, and acentric factor. These properties cannot be defined for polydisperse polymers, and parameters were determined from a combination of liquid density (PVT) data and polymer + solvent cloud point (xPT) data. Binary interaction parameters have been obtained for over 50 mixtures by correlating the fluid phase boundaries. Binary mixtures including ethylene, hexane, and/or cyclohexane are of particular interest to polyethylene production. A single binary interaction parameter is usually sufficient to represent vapor−liquid equilibrium, but temperature dependence is required to accurately represent liquid−liquid equilibrium. The MSL equation of state can be used to correlate the cloud points of polyethylene solutions at high pressures.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie801451a

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10657–10663

Titre :	Adsorption of aniline on cross-linked starch sulfate from aqueous solution
Type de document :	texte imprimé
Auteurs :	Lei Guo, Auteur ; Guiying Li, Auteur ; Junshen Liu, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10657–10663
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Adsorption--Aniline--Cross-Linked--Starch--Sulfate--Aqueous--Solution
Résumé :	A new environment friendly adsorbent, cross-linked starch sulfate (CSS), was prepared and used to adsorb aniline from aqueous solution. Different adsorption parameters like initial pH, adsorption time, equilibrium aniline concentration, and temperature were thoroughly studied, and the kinetic, equilibrium, and thermodynamics of the adsorption process were further investigated. It showed that CSS can effectively remove aniline from the solution. The adsorption capacity is highly dependent on the amount of sulfate groups on adsorbents and the initial pH. The pseudo-first-order and pseudo-second-order kinetic models were applied to test the experimental data, and the pseudo-second-order kinetic model provided a better correlation of the experimental data in comparison with the pseudo-first-order model. The maximum removal efficiency of aniline is 75.29% using 1 g L−1 of CSS3 dose. Langmuir, Freundlich, Dubinin−Radushkevich, and Sips models have been applied to study the adsorption equilibrium, and the equilibrium adsorption data were well described by the Sips isotherms. The Scatchard plot analysis was used to evaluate the binding sites of CSS. The adsorption of aniline on CSS is exothermic in nature.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9010782

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10650–10656

Titre :	Potential of silver-based room-temperature ionic liquids for ethylene/ethane separation
Type de document :	texte imprimé
Auteurs :	Lara M. Galán Sánchez, Auteur ; G. Wytze Meindersma, Auteur ; André B. Haan, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10650–10656
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Potential--Silver-Based--Room-Temperature--Ionic Liquids--Ethylene/Ethane--Separation
Résumé :	The potential of room-temperature ionic liquids (RTILs) in separating ethylene from ethane is investigated. The absorption of olefins is enhanced by chemical absorption via π-complex formation with a transition-metal cation added to a standard RTIL. The effects of the ionic liquid structure of silver-based RTILs that contain Ag(I) salts (AgNO3, Ag[TfO], and Ag[Tf2N]) on gas absorption and solvent stability are investigated. The absorption isotherms of C2H4 and C2H6 into standard RTILs and designed silver-based RTILs were measured with a gravimetric balance between 303 and 333 K and up to 10 bar. C2H4 absorption was chemically enhanced in the silver-based RTILs and was considerably higher than that in the standard RTILs. Absorption of C2H6 in the silver-based RTILs is based on physical interactions only. The olefin/paraffin selectivity at a pressure of 1 bar was ∼30−50 higher in the silver-based RTILs than in standard ionic liquids.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9010244

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10643–10649

Titre :	Studies on performance of crossflow concentric-ring rotating bed
Type de document :	texte imprimé
Auteurs :	Guang Q. Wang, Auteur ; Yun Q. Jiao, Auteur ; Zhi C. Xu, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10643–10649
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Studies--Performance--Crossflow--Concentric-Ring--Rotating Bed
Résumé :	A new kind of high-gravity device—crossflow concentric-ring rotating bed was developed, of which the rotor contains a series of perforated concentric rings. In operation, the gas could repeatedly crosscurrently make contact with the dispersed liquid flow between the concentric rings. The rotor structures and flow arrangements determine the device’s potential features, such as lower pressure drop and power consumption, which, together with the multiple-contact mechanism, are favorable to gas−liquid stripping processes. In a pilot crossflow concentric-ring rotating bed, the performance of the rotor was investigated under different operation conditions. The experimental results show that the pressure drop Δp, the power consumption P, and the mass transfer coefficient kLa fall within the range of 0.03−1.02 kPa, 0.65−1.08 kW, and 0.027−0.071 s−1, respectively. Empirical correlations based upon the experimental data were proposed to describe the dependence of pressure drop and power consumption on operation parameters. Compared with packed columns and spray contactor, the crossflow concentric-ring rotating bed has great advantages in mass transfer, equipment size, and gas/liquid loading despite the additional energy consumption. Moreover, the crossflow concentric-ring rotating bed shows lower pressure drop, power consumption, and mass transfer coefficient than that of counterflow or crossflow rotating packed beds. However, considering that stripping makes no high demand on mass transfer, crossflow concentric-ring rotating bed can be a promising option in performing stripping processes.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900956r

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10637–10642

Titre :	Modeling of cross-flow filtration processes in an airlift ceramic membrane reactor
Type de document :	texte imprimé
Auteurs :	Feng Zhang, Auteur ; Wenheng Jing, Auteur ; Weihong Xing, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10637–10642
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Modeling--Cross-Flow--Filtration--Processes--Airlift--Ceramic--Membrane--Reactor
Résumé :	Air sparging is recognized as an effective way to overcome concentration polarization in membrane filtration processes. The mechanism of flux enhancement in the case of slug flow in tubular ceramic membrane is discussed in this Article. The region near the gas slug is divided into three different zones: gas slug zone, wake zone, and remaining liquid slug zone. Air sparging significantly increases shear stress and flow instabilities, and consequently lowers concentration polarization for the gas slug zone and the wake zone. A novel model based on hydrodynamics of air−liquid two-phase flow is developed to predicting permeate flux in such processes. The dimensionless groups of filtrate resistance number and shear stress number are used to analyze the cake resistance induced by the concentration polarization, and, from these, the average permeate flux for air sparged ultrafiltration can be calculated. The model was tested by the ultrafiltration of T2000 dextran at different gas flow rates with an external-loop airlift ceramic membrane reactor. The model is validated with experimental data with an error of 10%. Experimental results show that air sparging can enhance the permeate flux significantly.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900512g

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10627–10636

Titre :	Adsorption of divalent lead on a montmorillonite−illite type of clay
Type de document :	texte imprimé
Auteurs :	John U. Kennedy Oubagaranadin, Auteur ; Z. V. P. Murthy, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10627–10636
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Adsorption--Divalent Lead--Montmorillonite−Illite--Clay
Résumé :	Lead(II) was removed from aqueous solution by adsorption on a montmorillonite−illite type of clay (MIC) collected from the Gulbarga district of Karnataka, India. The objectives of the current work were (i) to characterize the clay (adsorbent) and (ii) to perform equilibrium, kinetic, mass-transfer, and thermodynamic studies for the adsorption of Pb(II) on the clay. Batch adsorption equilibrium data were determined with different initial Pb(II) concentrations (100, 150, and 200 ppm) at pH 4 and 37 °C, and the data were tested with isotherm models. The three-parameter Freundlich−Langmuir model gave the best fit to the equilibrium data (R2 = 0.9979). However, as the initial Pb(II) concentration was increased (150 and 200 ppm), multilayer adsorption was observed. The maximum monolayer adsorption capacity of the clay was determined to be ∼52 mg/g. Kinetic studies indicated that the rate of adsorption of Pb(II) on the clay followed a second-order rate mechanism, with decreasing rate constant values of 0.1097, 0.0571, and 0.0022 g/(mg min) as the initial Pb(II) concentration was increased in the order of 100, 150, and 200 ppm, respectively. The value of the Freundlich constant (n) in the range of 2.5−4.6 indicated that MIC was a good adsorbent of divalent lead. At a higher initial Pb(II) concentration (200 ppm), the adsorption process was determined to be film-diffusion-controlled, with a rate of 0.051 min−1. The mean values of the thermodynamic parameters—the change in the free energy (ΔH°), the change in the entropy (ΔS°), and the change in the Gibbs free energy (ΔG°) showed that the adsorption process was endothermic, thermodynamically favorable, and spontaneous. A two-stage adsorber system that has been proposed reduced the clay dose by 8.5%, compared to that of a single-stage adsorption system.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9005047

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10619–10626

Titre :	Catalytic wet peroxide oxidation of phenol in a new two-impinging-jets reactor
Type de document :	texte imprimé
Auteurs :	Asghar Molaei Dehkordi, Auteur ; Amir Ali Ebrahimi, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10619–10626
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Catalytic--Peroxide--Oxidation--Phenol--Impinging-Jets--Reactor
Résumé :	The catalytic wet peroxide oxidation (CWPO) of phenol with activated carbon (AC) as the catalyst has been successfully tested in a novel type of two-impinging-jets reactor (TIJR). The TIJR is characterized by a high-intensity reaction chamber, which is separated by a perforated plate from other parts of the reactor. The perforated plate was used as a filter to keep the catalyst particles within the reaction chamber. The influences of various operating and design parameters such as jet Reynolds number, feed flow rate, internozzle distance, and the jet diameter on the performance capability of the TIJR were investigated. As a result of the impinging process, turbulence, complex trajectory of AC particles, relatively high local concentration of hydrogen peroxide, and the relatively high local catalyst loading within the reaction chamber, the fractional disappearance of phenol and the total organic carbon (TOC) removal, obtained in the TIJR, increased compared to those obtained by conventional reaction systems such as packed-bed reactors and batch stirred-tank reactors. This may be attributed to the elimination of the external mass-transfer resistance around the solid particles, complex flow pattern within the reaction chamber, energy released as the result of impinging-jets collision, efficient use of hydrogen peroxide caused by the contact pattern provided by the TIJR, and the high-intensity mixing especially at the impingement zone of the TIJR.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9004496

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10614–10618

Titre :	Turnip (brassica rapa) peroxidase : purification and characterization
Type de document :	texte imprimé
Auteurs :	Sepideh Motamed, Auteur ; Farnoosh Ghaemmaghami, Auteur ; Alemzadeh, Iran, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10614–10618
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Turnip--(Brassica rapa)--Peroxidase--Purification--Characterization
Résumé :	Partial purification of plant peroxidase from turnip (Brassica rapa) was optimized. Aqueous two phase system and precipitation by ammonium sulfate (as two parallel purification methods) were used. Polyethylene glycol/ammonium sulfate/NaCl (25:7:3%, w/v) system followed by gel-filtration chromatography gave a purification factor of about 36 fold. On the other hand, ammonium sulfate precipitation (60−80% deg) followed by gel filtration gave only about 13 purification fold. Hence, the aqueous two-phase system was more efficient and useful method as a primary purification step since it was less laborious, less time-consuming, and led to more purification factor. The partially purified turnip enzyme was stable at a pH range 2.6−6.0 and had an optimum pH at 4.0. The enzyme was stable up to 55 °C with an optimum activity at 35 °C.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie801997e

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10604–10613

Titre :	Magnesia-stabilized calcium oxide absorbents with improved durability for high temperature CO2 capture
Type de document :	texte imprimé
Auteurs :	Liyu Li, Auteur ; David L. King, Auteur ; Zimin Nie, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10604–10613
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Magnesia-Stabilized--Calcium--Oxide--Absorbents--Improved--Durability--Temperature--CO2 Capture
Résumé :	Calcium oxide based materials are attractive regenerable absorbents for separating CO2 from hot gas streams because of their high reactivity, high CO2 capacity, and low material cost. Their high carbonation temperature makes it possible to recover and use high quality heat released during CO2 capture, which increases overall process efficiency. However, the performance of all reported CaO-based absorbents deteriorates as the number of carbonation−decarbonation cycles increases. This is caused by absorbent sintering during the highly exothermic carbonation process. We have found that sintering can be effectively mitigated by properly mixing with a modest amount of MgO. A class of CaO-based absorbents with improved durability and CO2 reactivity were prepared by physical mixing of Ca(CH3COO)2 with small MgO particles followed by high temperature calcination. With 26 wt % MgO content, a CaO−MgO mixture prepared by this method gives as high as 53 wt % CO2 capacity after 50 carbonation−decarbonation cycles at 758 °C. Without MgO addition, the CO2 capacity of pure CaO obtained from the same source decreases from 66 wt % for the first cycle to 26 wt % for the 50th cycle under the same test conditions.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901166b

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10594–10603

Titre :	Method for evaluating single-end control of distillation columns
Type de document :	texte imprimé
Auteurs :	William L. Luyben, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10594–10603
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Method--Evaluating--Single--Control--Distillation--Columns
Résumé :	Distillation columns are, in an ideal situation, controlled using a dual-composition structure in which the light-key impurity in the bottoms and heavy-key impurity in the distillate are both maintained at the specified values. This structure minimizes energy consumption. However, it is often almost as efficient to use one-end control of either a composition or a temperature. This single-end distillation control structure is widely used in industry because of its simplicity and because it avoids dynamic interaction between the two competing loops. Because distillation columns have two control degrees of freedom, another variable besides the single temperature or composition must be selected among several alternatives. Usually these choices involve a ratio so that feed rate changes can be effectively handled. However, different ratio schemes handle feed composition changes with different degrees of effectiveness. The two most commonly used are either a reflux-to-feed ratio (R/F) or a reflux ratio (RR). The purpose of this Article is to present a methodology for deciding if single-end control can be effective and, if so, which ratio should be used. A steady-state simulation is used in which the two product purities (or impurities) are held constant as feed composition is varied around the design value. Plots are made of the two ratios (R/F and RR). If one of these curves shows little sensitivity to feed composition, it should be used in a single-end control structure. If both ratios show significant change, a dual control structure (two compositions, two temperatures, or one of each) is required to handle feed composition disturbances.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900778r

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10584–10593

Titre :	Heavy Metal Ions Removal in the Presence of 1-Hydroxyethane-1,1-diphosphonic Acid From Aqueous Solutions on Polystyrene Anion Exchangers
Type de document :	texte imprimé
Auteurs :	Dorota Kołodyńska, Auteur ; Zbigniew Hubicki, Auteur ; Alicja Skiba, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10584–10593
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Heavy Metal--Removal--Presence--1-Hydroxyethane-1--1-diphosphonic--Acid--Aqueous--Solutions--Polystyrene--Anion Exchangers
Résumé :	In the presented paper, the ability of commercially available gel and macroporous polystyrene anion exchangers for the removal of copper(II), zinc(II), nickel(II), and cadmium(II) complexes with 1-hydroxyethane-1,1-diphosphonic acid (HEDP) from aqueous solutions was investigated under various experimental conditions. In the experiments, the strongly basic anion exchangers Lewatit MonoPlus M 600, Lewatit MonoPlus MP 500, and Amberlite IRA 402 with the quaternary ammonium functional groups as well as the medium basic anion exchanger Lewatit MonoPlus MP 64 with the quaternary ammonium/tertiary amine functional groups were used. Special attention was paid to the concentration of heavy metal ions, M(II)−HEDP molar ratio, pH of solutions, temperature, and the physicochemical properties of the anion exchangers used. The effect of the interfered ions such as Ca(II), Mg(II), Cl−, NO3−, and SO42− on the efficiency of heavy metal complexes with HEDP sorption was also investigated. It was found that polystyrene anion exchangers rapidly sorbed the test metal complexes with HEDP, and the process became saturated in 20 min. The sorption kinetic data showed pseudo-second-order reaction kinetics rather than the pseudo-first-order kinetics. The adsorption behavior of Cu(II), Zn(II), Ni(II), and Cd(II) complexes with HEDP was studied in single as well as in multicomponent competitive systems. The obtained data were fitted well by the Langmuir adsorption isotherm model. Maximum sorption capacities for Cu(II), Zn(II), Ni(II), and Cd(II) complexes with HEDP occurred for strongly basic anion exchanger Lewatit MonoPlus M 600 at the optimal pH 11.5 and were found to be 96.15, 80.64, 70.42, and 142.85 mg/g, respectively. For binary and quaternary metal complexes solutions, these values were smaller than those from single metal solutions. The presence of Cu(II) and Zn(II) complexes more strongly inhibited Ni(II) and Cd(II) once sorption occured which indicates their greater affinity than that of the remaining complexes for the anion exchangers.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901195j

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10577–10583

Titre :	Asymmetric hollow fiber membranes for separation of CO2 from hydrocarbons and fluorocarbons at high-pressure conditions relevant to C2F4 polymerization
Type de document :	texte imprimé
Auteurs :	Madhava R. Kosuri, Auteur ; William J. Koros, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10577–10583
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Asymmetric--Hollow Fiber--Membranes--Separation--CO2--Hydrocarbons --Fluorocarbons--High-Pressure--Conditions--Relevant--C2F4--Polymerization
Résumé :	Separation of high-pressure carbon dioxide from fluorocarbons is important for the production of fluoropolymers such as poly(tetrafluoroethylene). Typical polymeric membranes plasticize under high CO2 partial pressure conditions and fail to provide adequate selective separations. Torlon, a polyamide−imide polymer, with the ability to form interchain hydrogen bonding, is shown to provide stability against aggressive CO2 plasticization. Torlon membranes in the form of asymmetric hollow fibers (the most productive form of membranes) are considered for an intended separation of CO2/C2F4. To avoid safety issues with tetrafluoroethylene (C2F4), which could detonate under testing conditions, safer surrogate mixtures (C2H2F2 and C2H4) are considered in this paper. Permeation measurements (at 35 °C) indicate that the Torlon membranes are not plasticized even up to 1250 psi of CO2. The membranes provide mixed gas CO2/C2H2F2 and CO2/C2H4 selectivities of 100 and 30, respectively, at 1250 psi partial pressures of CO2. On the basis of the measured separation performances of CO2/C2H2F2 and CO2/C2H4 mixtures, the selectivity of the CO2/C2F4 mixture is expected to be greater than 100. Long-term stability studies indicate that the membranes provide stable separations over a period of 5 days at 1250 psi partial pressures of CO2, thereby making the membrane approach attractive.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900803z

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10564–10576

Titre :	Design and control of heterogeneous azeotropic column system for the separation of pyridine and water
Type de document :	texte imprimé
Auteurs :	Yi Chang Wu, Auteur ; Chien, I-Lung, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10564–10576
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Design--Control--Heterogeneous--Azeotropic--Column-- Separation--Pyridine
Résumé :	The design and control of two types of separation systems using heterogeneous azeotropic distillation have been studied in the literature. One type (e.g., isopropyl alcohol dehydration) is to add a light entrainer (cyclohexane) into the system so that a minimum-boiling ternary azeotrope is formed which can split into two liquid phases in a decanter. This type of system also introduces two additional azeotropes (isopropyl alcohol−cyclohexane and water−cyclohexane), thus dividing the ternary system into three distillation regions. Another type (e.g., acetic acid dehydration) does not contain azeotrope in the original system. However, due to a tangent pinch near the pure water end an entrainer (isobutyl acetate) is added into the system to aid the separation. This type of system has only one binary heterogeneous azeotrope (water−isobutyl acetate); thus there is only one distillation region. In this paper, design and control of a different residue curve map (RCM) type of separation system utilizing heterogeneous azeotropic distillation will be studied. An example of this RCM type is pyridine and water separation using toluene as entrainer. Adding toluene into this system introduces two additional azeotropes, one is minimum-boiling binary heterogeneous azeotrope (water−toluene) and the other one is a binary homogeneous azeotrope (pyridine−toluene). There is no ternary azeotrope for this system. Two alternative design flow sheets are compared in this paper to find the one which is most economical and also meet stringent product purity specifications. A simple overall control strategy of this process has also been developed which requires only one temperature control loop in each column.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901231s

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10551–10563

Titre :	Design and control of the monoisopropylamine process
Type de document :	texte imprimé
Auteurs :	William L. Luyben, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10551–10563
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Design--Control--Monoisopropylamine--Process
Résumé :	The monoisopropylamine (MIPA) process provides an interesting example of plantwide economic design optimization and plantwide control. The process consists of a tubular reactor and three distillation columns. There are both gas and liquid recycles. Fresh feed streams of isopropyl alcohol and ammonia are introduced into the process. The desired products are MIPA and water. An undesirable byproduct of di-isopropylamine (DIPA) is also produced and is recycled to extinction since its formation reaction is reversible. An excess of ammonia in the reactor inhibits the DIPA reaction, so ammonia is also recycled. The purpose of this paper is to present the details of the process for use by other workers as a test case for use in plantwide design and control studies. A heuristic economic optimum design and a control structure are developed. The process illustrates the classical design trade-off between reactor costs versus separation costs. In addition, the process has two recycles, which are both distillate products from different distillation columns, and this leads to another trade-off. Using more ammonia recycle produces less DIPA recycle. So the optimum design must balance the separation costs of the two recycles. Two of the distillation columns can be effectively controlled using a single temperature and a reflux-to-feed ratio control structure. The third column requires a dual control structure ratio (one temperature and one composition).
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900965s

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10541–10550

Titre :	Effects of H2O and particles on the simultaneous removal of SO2 and fly ash using a fluidized-bed sorbent/catalyst reactor
Type de document :	texte imprimé
Auteurs :	Jui-Yeh Rau, Auteur ; Jyh-Cherng Chen, Auteur ; Ming-Yen Wey, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10541–10550
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Effects--H2O--Particles--Simultaneous--Removal--SO2--Using--Fluidized-Bed--Sorbent/Catalyst Reactor
Résumé :	This study investigated the potential of a fluidized-bed sorbent/catalyst reactor for the simultaneous removals of SO2 and fly ash from a simulated flue gas containing different H2O and particles. Experimental results showed that the removal efficiency of particles and SO2 was 85%−96% and 5.75−2.97 mg SO2/g, respectively, as the H2O content was 1.5−5.3%. The activities of sorbent/catalysts for simultaneous removals of SO2 and particles were inhibited by H2O and particles, and the inhibition effects increased with the content of H2O. As the H2O content increased, the particle size distribution (PSD) of fine particles shifted to the coarse particles. The results of BET analysis show that the obstruction phenomenon of the sorbent/catalyst caused by the particles was diminished with the increased content of H2O. The results showed this aggregation phenomenon of fine particles shifted to the coarse particles may cause increased water vapor content in fluidized-bed sorbent/catalyst reactor.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900843f

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10532–10540

Titre :	Two-stripper/decanter flowsheet for methanol recovery in the TAME reactive-distillation process
Type de document :	texte imprimé
Auteurs :	Yi Chang Wu, Auteur ; Chien, I-Lung, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10532–10540
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Two-Stripper/Decanter--Flowsheet--Methanol--Recovery--TAME--Reactive-Distillation--Process
Résumé :	The process to produce TAME via reactive distillation requires a methanol-recovery section because the presence of C5/methanol azeotropes means that a significant amount of methanol is present in the distillate from the reactive column. The use of pressure-swing azeotropic distillation and extractive distillation were studied in a previous paper in which both the steady-state design and the plantwide control of the entire process were developed. This paper considers a third alternative flowsheet for the separation of the C5/methanol azeotropes that takes advantage of the heterogeneity of the azeotrope. Two stripping columns and a decanter are used. The total annual cost of this flowsheet is a factor of 4 less than that of the pressure-swing system. The system is demonstrated to be easy to control by controlling a tray temperature in each stripping column.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900670f

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10522–10531

Titre :	Crystallization of hydrated ferric arsenate. process design using METSIM
Type de document :	texte imprimé
Auteurs :	Pía C. Hernández, Auteur ; María E. Taboada, Auteur ; Teófilo A. Graber, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10522–10531
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Crystallization--Hydrated--Ferric--Arsenate--Process Design--Using METSIM
Résumé :	An industrial process for extracting arsenic from solutions through scorodite crystallization at 70 °C was designed and simulated using METSIM software. Using equilibrium information from the phase diagram of the system As(V)/Fe(III)/H2O at 50 and 70 °C, experimental tests were carried out of crystallization of scorodite at 50, 70, and 95 °C, as well as crystallization at 170 °C in an autoclave. This information provides the preliminary operational conditions for the process. The tests show that temperature influences the quality of crystals and the velocity of scorodite crystallization (residence time between 3 h and 3 days). The simulated process allows for the analysis of different evaporation ratios (42.5, 71.97, and 86.7%), determining the material and energy balances and the quality of the products and residues, thus providing important information for potential industrial applications. The energy requirements for each evaporation ratio are 21 568, 33 747, and 39 836 Mcal/h, and the sums of the total flows are 11 588.60, 8876.28, and 7520.11 tons/day, respectively. This last variable is related to the size of the equipment used in the process. Molar Fe/As ratios of 1, 0.9, and 0.8 result in yields of 93, 88, and 78%.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900639e

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10515–10521

Titre :	Predictive ratio control for interacting processes
Type de document :	texte imprimé
Auteurs :	Tan, Kok Kiong, Auteur ; Tay, Arthur, Auteur ; Zhao Shao, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10515–10521
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Predictive--Ratio--Control--Interacting--Processes
Résumé :	In this paper, a predictive-PID ratio control scheme is developed for multivariable processes. The Generalized predictive control based PID configuration is incorporated into various conventional ratio control schemes. Conventional parallel and series ratio control cannot satisfy the stringent requirements. The proposed method is applied to the wafer temperature uniformity control in the lithography. Both simulation and experimental results show the effectiveness of the proposed predictive ratio control method.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900219u

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10504–10514

Titre :	Near-optimization of operating conditions and residence times in multizone dryers for polymer coatings
Type de document :	texte imprimé
Auteurs :	Raj K. Arya, Auteur ; Madhu Vinjamur, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10504–10514
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Near-Optimization--Operating Conditions--Residence--Multizone--Dryers--Polymer Coatings
Résumé :	Several polymeric coatings are dried by blowing jets of hot air on them from the top and bottom sides in multizone dryers. The goal of quickly removing solvent from a coating by manipulating air flow and temperature, together called operating conditions in this work, conflicts with the goal of producing blister-free coatings. Optimum operating conditions ensure both minimum residual solvent and no defects. Determining optimum conditions for multizone dryers is a difficult task with severe convergence problems. In this work, an easy method is developed to determine near-optimum operating conditions and residence times. The results indicate that the air flow on the top side should always be lower than or equal to that on the bottom side; the minimum residence time in first zone should be such that, toward the end, the solvent concentration starts to fall at the bottom. As long as the residence times are reasonably long, several different combinations of residence times in the second and subsequent zones nearly minimize residual solvent.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900604f

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10498–10503

Titre :	Glass-based processing of mixed-oxide desulfurization sorbents
Type de document :	texte imprimé
Auteurs :	Michael D. Dolan, Auteur ; Alex Y. Ilyushechkin, Auteur ; Keith G. McLennan, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10498–10503
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Glass-Based--Processing--Mixed-Oxide--Desulfurization--Sorbents
Résumé :	The favorable thermodynamics of the reaction between H2S and oxides of iron, nickel, and zinc make these materials suitable for the sorption of sulfur from coal-derived synthesis gas. As an alternative to traditional solid-state processing, the suitability for coal gas desulfurization of glass-ceramics based on transition metal oxides has been evaluated. Glass-ceramics based on NiAl2O4 and ZnFe2O4 have similar sorption properties and a high resistance to agglomeration, but the inexpensive raw materials and moderate processing temperature of the ZnFe2O4-based glass makes it more suitable for a commercial application. The overall performance is highly dependent on the particle size of the sorbent, but these materials can be formed with relatively high surface areas by using fiber-based processing. This material is a potential alternative to mixed oxide sorbents prepared by solid-state processing, as it offers comparable performance combined with the ability to process the glass by existing glass-processing techniques.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901170f

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10491–10497

Titre :	Mechanical and morphological properties of chemically treated coir-filled polypropylene composites
Type de document :	texte imprimé
Auteurs :	Md. Nazrul Islam, Auteur ; Md. Mominul Haque, Auteur ; Md. Monimul Huque, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10491–10497
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Mechanical--Morphological--Chemically Treated--Coir-Filled--Polypropylene Composites
Résumé :	In the present work, coir was chemically treated first with sodium perchlorate and then with 2,4-dinitrophenyl hydrazine (DNPH) to improve the mechanical properties of the coir−PP composites. Untreated, oxidized, and DNPH-treated coir samples at different mixing ratios were utilized to prepare the composites. Mechanical properties of the composites prepared from both perchlorate and DNPH-treated coir were found to be better than those of untreated ones. The tensile strengths of both untreated and treated coir−PP composites decreased with an increase in fiber content. However, the values were found to be higher than those of corresponding values of untreated ones. Treated coir−PP composites were found to absorb a lower amount of water than the untreated ones. To understand why the mechanical properties of composites prepared under different conditions of coir were different, surface morphologies of the tensile fractured surfaces of the specimens were recorded using scanning electron microscopy (SEM). The SEM images clearly revealed that there were fewer fiber agglomerations, microvoids, and fiber pull out traces in both perchorate and DNPH-treated coir−PP composite than in the untreated one, indicating that better distribution of the fiber into the matrix as well as stronger fiber matrix interfacial adhesion occurred upon treatment of coir.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900824c

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10485–10490

Titre :	Treatment of fractionated fibers with various cationic-modified poly(vinyl alcohols) and Its iImpact on paper properties
Type de document :	texte imprimé
Auteurs :	Pedram Fatehi, Auteur ; Jeffery E. Ward, Auteur ; Huining Xiao, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10485–10490
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Treatment--Fractionated Fibers--Various--Cationic-Modified--Poly(vinyl alcohols--Impact--Paper Properties
Résumé :	In this work, the effects of various high molecular weight cationic poly(vinyl alcohols), CPVAs, on the fiber morphology and the properties of papers made from fractionated refined fibers were investigated. At first, bleached sulfite fibers were refined under various revolutions and then refined fibers were fractionated under various time intervals to obtain refined fibers with a similar fiber length and fines content. Then, 20 mg/g CPVAs with various charge densities was adsorbed on the fractionated refined fibers prior to making hand sheets. The results showed that the lower the charge density of CPVA, the higher the effectiveness of CPVA in improving the paper strength at any refining revolution. The reasons for such a phenomenon were perhaps the different configurations of CPVAs on the surface of the fibers and the different adhesion/repulsion forces developed between CPVA-modified fibers in hand sheets. Also, by reducing the freeness of the fractionated fibers (increasing the refining revolutions), the effect of CPVA in improving the paper strength was reduced. In this case, the CPVAs tended to cover the fibrils on the fiber surface, which was demonstrated by SEM observations, thus reducing the contact area of the fractionated refined fibers.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900999n

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10479–10484

Titre :	Computational study on the influences of framework charges on CO2 uptake in metal−organic frameworks
Type de document :	texte imprimé
Auteurs :	Chengcheng Zheng, Auteur ; Dahuan Liu, Auteur ; Qingyuan Yang, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10479–10484
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Computational--Influences--Framework--Charges--CO2 Uptake--Metal-−Organic--Frameworks
Résumé :	This work involved a computational study to investigate the influences of framework charges on CO2 uptake in metal−organic frameworks (MOFs), in which a total of 20 MOFs with different topologies, pore sizes, and chemical characteristics were examined. The results showed that, at atmospheric pressure, the contribution of the framework charges is generally large, and a linear relationship with pore size was found, showing that, when the pore size is larger than 3.3 nm, the contribution becomes smaller than 10%. On the other hand, the framework charge contribution was found to decrease rapidly with increasing pressure and to become less than 10% at pressures higher than 2.0 MPa. This work shows that the framework charge contribution in MOFs cannot be ignored in computational screening of MOF materials for CO2 capture under low-pressure conditions, whereas at moderate operating pressures, the contribution can be ignored in large-scale prescreening such as in the natural gas upgrading process.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901000x

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10472–10478

Titre :	New insights into coating uniformity and base sheet structures
Type de document :	texte imprimé
Auteurs :	Christina Dahlstrom, Auteur ; Tetsu Uesaka, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10472–10478
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	New Insights--Coating--Uniformity--Base Sheet--Structures
Résumé :	Base sheet structures, such as surface roughness and mass density distribution (formation), have been known to affect coating uniformity. However, the literature is not necessarily consistent in determining which structure controls coating uniformity. This study employed scanning electron microscopy (SEM) and image analysis, combined with autocorrelation and frequency analyses, to investigate the fundamental mechanisms of coating and to resolve some of the controversies in the literature regarding the base sheet effects. The results showed that coating thickness variation resembles a process of random deposition with leveling. At small length scales (in the size of fiber width), leveling causes a very strong dependence of coating thickness variations on the surface profile of the base sheet, whereas at larger length scales, coating thickness variation diminishes in its intensity by the same leveling effect, but still retains a significant correlation with base sheet structure, particularly formation. Frequency analyses clearly showed that the discrepancies in the results for the base sheet effects in the literature are due to the length scales used in the experiments, that is, the sampling area and the resolution of the measurements.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900819c

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10467–10471

Titre :	Hydrothermal Decarboxylation of Pentafluorobenzoic Acid and Quinolinic Acid
Type de document :	texte imprimé
Auteurs :	Jie Fu, Auteur ; Phillip E. Savage, Auteur ; Xiuyang Lu, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10467–10471
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Hydrothermal--Decarboxylation--Pentafluorobenzoic--Acid--Quinolinic--Acid
Résumé :	We report herein the first kinetics studies of hydrothermal decarboxylation of a fully halogenated benzoic acid and a heterocyclic aromatic diacid. Decarboxylation was the only reaction path observed, and there was no evidence of dehalogenation. Experiments at different initial reactant concentrations and different batch holding times revealed that both compounds exhibited first-order kinetics. Experiments at different temperatures showed that the first-order rate constants displayed Arrhenius behavior with activation energies of 157 kJ mol−1 for pentafluorobenzoic acid decarboxylation and 141 kJ mol−1 for quinolinic acid decarboxylation.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901182y

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10456–10466

Titre :	Photocatalytic reactor employing titanium dioxide : from a theoretical model to realistic experimental results
Type de document :	texte imprimé
Auteurs :	Roberto L. Romero, Auteur ; Orlando M. Alfano, Auteur ; Alberto E. Cassano, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10456–10466
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Photocatalytic--Reactor--Employing--Titanium Dioxide--Theoretical--Model--Realistic Experimental--Results
Résumé :	The performance of a reacting system for degradation of trichloroethylene (TCE) in a pilot-size annular photocatalytic reactor having a tubular lamp located at its centerline was studied. The reactor operation was carried out with commercial catalytic particles of titanium dioxide (Aldrich) in a water suspension. The description of the reactor performance was made by employing a kinetic model developed in a laboratory reactor of different size and configuration, irradiated with similar lamps of lower output power. The annular reactor was operated in the continuous mode but inside the loop of a recirculation system.The performance of the annular reactor was modeled by assuming three different behaviors: (i) a well-stirred tank reactor, (ii) a pseudo-steady-state laminar flow reactor in a batch recycle, and (iii) a transient-state laminar flow reactor in a recycle. Case iii produced the best representation of the experimental data. Along with the experimental validation of the developed theoretical models, three practical features were unveiled that had to be taken into account in any subsequent design: (a) an important change in the pH, from 6.5 to 3.5, along the reaction time; (b) a significant titanium dioxide deposition on the reactor walls; and (c) an appreciable catalyst agglomeration produced by the recirculation system and magnified by the change in pH. Only after the first 120 min of reaction time, the reactor conditions became almost stabilized; thus, the observed transformations had to be incorporated into the modeling.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900354y

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10448–10455

Titre :	Modeling of the kinetics for methanol synthesis using Cu/ZnO/Al2O3/ZrO2 catalyst : influence of carbon dioxide during hydrogenation
Type de document :	texte imprimé
Auteurs :	Hye-Won Lim, Auteur ; Myung-June Park, Auteur ; Suk-Hwan Kang, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10448–10455
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Modeling--Kinetics--Methanol--Synthesis--using--Cu/ZnO/Al2O3/ZrO2--Catalyst--Influence--Carbon Dioxide--during Hydrogenation
Résumé :	A kinetic model for methanol (MeOH) synthesis over Cu/ZnO/Al2O3/ZrO2 catalyst has been developed and selected to evaluate the effect of carbon dioxide on the reaction rates due to its high activity and stability. Detailed kinetic mechanism, on the basis of different sites on Cu for the adsorption of carbon monoxide and carbon dioxide, is applied, and the water−gas shift (WGS) reaction is included in order to provide the relationship between the hydrogenations of carbon monoxide and carbon dioxide. Parameter estimation results show that, among 48 reaction rates from different combinations of rate determining steps (RDSs) in each reaction, the surface reaction of a methoxy species, the hydrogenation of a formate intermediate HCO2, and the formation of a formate intermediate are the RDS for CO and CO2 hydrogenations and the WGS reaction, respectively. It is shown that the CO2 hydrogenation rate is much lower than the CO hydrogenation rate, and this affects the methanol production rate. However, carbon dioxide decreases the WGS reaction rate, which prevents methanol from converting to dimethyl ether, a byproduct. In such a way, a small fraction of carbon dioxide accelerates the production of methanol indirectly within a limited range, showing a threshold value of the CO2 fraction for the maximum methanol synthesis.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901081f

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10439–10447

Titre :	The development of a macro kinetic model for a commercial Co/Pt/Al2O3 fischer−tropsch catalyst
Type de document :	texte imprimé
Auteurs :	F. Gideon Botes, Auteur ; Braam van Dyk, Auteur ; Craig McGregor, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10439–10447
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Development--Macro--Kinetic--Model--Commercial--Co/Pt/Al2O3--Fischer−Tropsch--Catalyst
Résumé :	An experimental study was performed with an aged Co/Pt/Al2O3 catalyst in a laboratory slurry reactor to develop a macrokinetic expression for the Fischer−Tropsch (FT) synthesis. A semiempirical model was found to be the preferred two-parameter rate equation of the reaction. However, it was shown that this model is virtually indistinguishable from a mechanistically derived three-parameter rate model that assumes the following kinetically relevant steps in the cobalt-FT synthesis: CO dissociation occurs without hydrogen interaction and is not a rate-limiting step; the first hydrogen addition to surface carbon and the second hydrogen addition to surface oxygen are the rate-determining steps.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900119z

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10431–10438

Titre :	Evolution of char structure during the steam gasification of biochars produced from the pyrolysis of various mallee biomass components
Type de document :	texte imprimé
Auteurs :	Hongwei Wu, Auteur ; Kongvui Yip, Auteur ; Fujun Tian, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10431–10438
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Evolution--Structure--during--Steam--Gasification--Biochars--Produced--Pyrolysis--Various--Mallee--Biomass--Components
Résumé :	This study reports the evolution of char structure during the steam gasification of biochars under chemical-reaction-controlled conditions. Partially gasified samples were collected at various conversion levels during the steam gasification of both the raw biochars and the acid-treated biochars that had been prepared via acid-washing of the raw biochars. Results from FT-Raman spectroscopy show that the biochars have highly heterogeneous and disordered structures, which are selectively consumed with progress of steam gasification, leading to enrichment of larger aromatic ring systems, hence the so-called “selective gasification”. Selective gasification of biochar can be significantly influenced by the inherent alkali and alkaline earth metallic (AAEM) species in the biochars. The abundant catalysts present in the raw biochars can alter the gasification reaction pathway, but such an alteration appears to have little effect on the evolution of pore surface area, which increases significantly with conversion. While the wood biochar has too low a content of AAEM species to have an apparent effect on selective gasification, for the raw leaf and bark biochars with high contents of AAEM species, selective gasification is considerably less significant in comparison with the respective acid-treated biochars. For acid-treated biochars, gasification seems to take place slowly throughout the biochar on carbon active sites to consume the smaller rings selectively; the reactivity is controlled by the biochar carbon structure. However, for the raw leaf and bark biochars, gasification would be more focused or localized on the catalytic sites so that the activity of carbon active sites becomes less important. The catalytic effect of the inherent AAEM species seems to in turn depend on the carbon structure that probably affects the catalyst dispersion.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901025d

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10425–10430

Titre :	Kinetics of oxidative decarboxylation of 3,4-methylenedioxymandelic acid to piperonal with dilute nitric acid
Type de document :	texte imprimé
Auteurs :	Hongjuan Xi, Auteur ; Zhixian Gao, Auteur ; Jianguo Wang, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10425–10430
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Kinetics--Oxidative--Decarboxylation--3,4-Methylenedioxymandelic--Acid--Piperonal--Dilute Nitric
Résumé :	The oxidative decarboxylation of 3,4-methylenedioxymandelic acid (DMA) to piperonal with dilute nitric acid was investigated. This reaction was initiated by NaNO2 and catalyzed by H2SO4, but the autocatalytic behavior, which was noted in most nitric acid oxidation reactions, was not observed. Detailed kinetic study showed that the respective reaction orders of NaNO2, H2SO4, HNO3, and DMA were 0.5, 0.5, 1.2, and 1.8, and the activation energy was 59.65 kJ/mol. The gained reaction rate equation provided a good model for the reaction under other temperatures and even the condition of a slightly higher concentration of nitric acid. Additional experimental data suggested that HNO2 was the reactive species. On the basis of the results, a possible reaction mechanism was proposed.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900961r

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10414–10424

Titre :	Effect of Citric Acid Addition on Co−Mo/B2O3/Al2O3 Catalysts Prepared by a Post-Treatment Method
Type de document :	texte imprimé
Auteurs :	Nino Rinaldi, Auteur ; Tekeshi Kubota, Auteur ; Yasuaki Okamoto, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10414–10424
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Effect--Citric--Acid Addition--Co−Mo/B2O3/Al2O3--Catalysts--Prepared--Post-Treatment--Method
Résumé :	Co−Mo/B2O3/Al2O3 catalysts were prepared by a post-treatment of the calcined states with citric acid (CA) and were tested for the hydrodesulfurization (HDS) reaction of thiophene. The catalysts were characterized by LRS, UV−visible spectroscopy, Mo K-edge EXAFS, TEM, NO adsorption capacity, and surface area measurements. Catalysts obtained by simultaneous impregnation with citric acid were also prepared for comparison. Sulfided catalysts were characterized by a chemical vapor deposition (CVD) technique using Co(CO)3NO. The addition of citric acid in a post-treatment more effectively increased the catalytic activity and NO adsorption capacity than did addition by a simultaneous-impregnation method. Co-CA and Mo-CA surface complexes formed at the expense of CoMoO4 and polymolybdates. The maximum potential activity of Co−Mo/B2O3/Al2O3 was obtained by a simple post-treatment of the calcined catalyst with citric acid.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9008343

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10408–10413

Titre :	Dependence of sulfadiazine oxidative degradation on physicochemical properties of manganese dioxides
Type de document :	texte imprimé
Auteurs :	Chengshuai Liu, Auteur ; Lijia Zhang, Auteur ; Fangbai Li, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10408–10413
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Dependence--Sulfadiazine--Oxidative--Degradation--Physicochemical--Properties--Manganese--Dioxides
Résumé :	Manganese dioxides as active oxidants are the common minerals in environment, and different types of manganese dioxides may exhibit varied oxidative activity. In this study, eight manganese dioxides were used to conduct sulfadiazine (SD) oxidative degradation. SD can be oxidatively degraded and even mineralized by these manganese dioxides, and the toxicity of the SD sample can also be reduced significantly. The experiments in this study demonstrated that the kinetic reaction rate constant k values of SD degradation strongly depended on the physicochemical properties of different manganese dioxides, including average oxidation state (AOS), reductive potential (Eh), pH at the point of zero charge (pHPZC), and apparent activation energy (Ea). The k values were positively correlated with the AOS and Eh, while negatively correlated with pHPZC and Ea. The values of these physicochemical properties can be used to quantitatively estimate the oxidative activity of a manganese dioxide to some extent for better understanding of the degradation of organic pollutants with manganese dioxides.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900812j

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10402–10407

Titre :	Au/FeOx−TiO2 catalysts for the preferential oxidation of CO in a H2 stream
Type de document :	texte imprimé
Auteurs :	Yi-Fen Yang, Auteur ; Palanivelu Sangeetha, Auteur ; Chen, Yu-Wen, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10402–10407
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Au/FeOx−TiO2--Catalysts--Preferential--Oxidation--CO--H2--Stream
Résumé :	A series of gold catalysts supported on Fe2O3−TiO2 with various iron contents were prepared. A FeOx−TiO2 support was prepared via incipient-wetness impregnation with aqueous solution of Fe(NO3)3 on TiO2. A gold catalyst with a nominal loading of 1 wt % was prepared by deposition−precipitation at pH 7 and 65 °C. The catalysts were characterized by X-ray diffraction, transmission electron microscopy, and X-ray photoelectron spectroscopy. The catalytic performance of these catalysts were investigated by preferential oxidation of carbon monoxide in hydrogen stream (PROX). The reaction was conducted in a fixed-bed microreactor with a feed of CO:O2:H2:He = 1:1:49:49 (volume ratios). A limited amount of oxygen was used. Gold catalysts have been reported to be efficient catalysts for the PROX reaction to reduce CO concentration to <50 ppm. The Au/TiO2 catalyst had high CO and H2 oxidation activity. However, CO conversion decreases obviously when the temperature reaches above 80 °C, because of the competition of hydrogen oxidation on the catalysts. In this study, FeOx was added to Au/TiO2 to suppress H2 oxidation without sacrificing the activity for CO oxidation. Adding a suitable amount of Fe2O3 on Au/TiO2 could enhance CO conversion to a higher extent and suppress H2 oxidation. In the highly active gold-supported catalysts, the amorphous nature of Fe2O3, along with TiO2, not only enhanced electronic interaction but also stabilized the nanosized gold particles, thereby enhancing the catalytic activity of CO oxidation toward a higher extent.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900806r

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10395–10401

Titre :	Morphological characterization of ceramic sponges for applications in chemical engineeringc
Type de document :	texte imprimé
Auteurs :	Julia Grosse, Auteur ; Benjamin Dietrich, Auteur ; Gerardo Incera Garrido, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10395–10401
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Morphological--Characterization--Ceramic Sponges--Applications--Chemical Engineering
Résumé :	An extensive study on morphological parameters of ceramic sponge structures of different material, porosity, and pores per linear inch (ppi) number was performed. Volume image analyses of magnetic resonance imaging (MRI) and X-ray tomography (CT) measurements were carried out to determine experimentally the geometric specific surface area of the structures. Furthermore, face and strut diameters, porosities, and densities were assessed through conventional methods including optical microscopy, mercury porosimetry, and helium pycnometry. The resulting data were used to evaluate morphological models representing the irregular strut network by packings of regular polyhedra. On the basis of an adapted Weaire−Phelan model, a novel correlation was developed that enables the calculation of the specific surface area of sponges with high accuracy. The input parameters for this correlation are easily accessible by standard microscopy and porosimetry measurements.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900651c

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10387–10394

Titre :	Heterogeneously-catalyzed glycerolysis of fatty acid methyl esters : reaction parameter optimization
Type de document :	texte imprimé
Auteurs :	Cristián A. Ferretti, Auteur ; Roberto N. Olcese, Auteur ; Carlos R. Apesteguía, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10387–10394
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Heterogeneously-Catalyzed--Glycerolysis--Fatty Acid--Methyl--Esters--Reaction Parameter--Optimization
Résumé :	The synthesis of monoglycerides by glycerolysis of methyl oleate, an unsaturated fatty acid methyl ester, was studied on strongly basic high surface area MgO as an alternative to the current commercial technology that uses liquid base catalysts. Initially, the reaction conditions such as catalyst particle size and stirring rate required for operating the four-phase reactor under a kinetically controlled regime were determined. Then, the optimization of the reaction parameters for achieving high monoglyceride yields was performed. Results showed that glycerolysis of methyl oleate on MgO compares favorably with the corresponding homogeneously catalyzed process. In fact, when using high reaction temperatures (493−523 K), glycerol/methyl oleate molar ratios between 2 and 6, and catalyst/reactant ratios of about 30 g/mol, glycerolysis of methyl oleate on MgO yields up to 77% monoglycerides in 2 h, a much higher value than those usually obtained via the liquid-base-catalyzed homogeneous process (40−60%).
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9004783

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10381–10386

Titre :	Osmium(VIII) catalyzed oxidative cleavage of pyrrolidine ring in l-proline by hexacyanoferrate(III) in alkaline media
Type de document :	texte imprimé
Auteurs :	K. Sharanabasamma, Auteur ; Mahantesh A. Angadi, Auteur ; Manjalee S. Salunke, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10381–10386
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Osmium(VIII)--Catalyzed--Oxidative Cleavage--Pyrrolidine--Proline--Hexacyanoferrate(III)--Alkaline Media
Résumé :	Kinetics of oxidation of l-proline by hexacyanoferrate(III) catalyzed by osmium(VIII) in alkaline medium was studied at 30 °C. A mechanism involving free radical path was proposed. Rate law of the reaction was derived as The rate constant k and equilibrium constants K1 and K2 were evaluated as 3.79 × 103 dm3 mol−1 s−1, 0.52 dm3 mol−1, and 3.78 × 103 dm3 mol−1, respectively. The main reactive species of the catalyst appears to be OsO5(OH)3−. The oxidative product of l-proline was identified as l-glutamic acid which is different from the earlier reports. The literature reveals that 4-amino butyric acid, 4-amino butaraldehyde and keto acids were the oxidative products. Activation parameters were evaluated as Ea = 33.5 ± 2 kJ mol−1, ΔH⧧ = 31.0 ± 0.2 kJ mol−1, ΔS⧧ = −24 ± 1.5 J K−1 mol−1, ΔG⧧ = 38.0 ± 2 kJ mol−1.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901049p

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10375–10380

Titre :	Amine-functionalized ordered mesoporous silica transesterification catalysts
Type de document :	texte imprimé
Auteurs :	Victor Varela Guerrero, Auteur ; Daniel F. Shantz, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10375–10380
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Amine-Functionalized--Ordered--Mesoporous--Silica--Transesterification--Catalysts
Résumé :	The synthesis, characterization, and catalytic behavior of several amine-functionalized ordered mesoporous silica (OMS) materials are reported. All samples show catalytic activity for the conversion of glyceryl tributyrate with methanol to methyl esters in high yield (>60%). The reactivity of the amines approximately correlates with the pK values of the free amines. The effect of the amine identity, loading, and substrate pore size is also reported. To determine if leached amine was responsible for the observed reactivity, the hot filtrate method was employed. Those experiments show that upon removal of the OMS material the reaction conversion does not increase, indicating surface-tethered amines are primarily responsible for the observed reactivity. The stability of the most promising catalyst, 3-(anilinopropyl)-MCM-41 was analyzed via recycle studies. Leaching of the amine is observed via a decrease in conversion with multiple recycles and a concomitant change in sample color. Capping the residual silanols groups with hexamethyldisilazane leads to an increase in the catalyst stability with a decrease in activity. The work indicates that these solids are interesting alternatives to conventional homogeneous catalysts for this class of chemistry.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9003915

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10364–10374

Titre :	Effects of pretreatment of coal by CO2 on nitric Oxide emission and unburned carbon in various combustion environments
Type de document :	texte imprimé
Auteurs :	Benson B. Gathitu, Auteur ; Wei-Yin Chen, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10364–10374
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Effects--Pretreatment--CO2--Nitric Oxide--Emission--Unburned--Carbon--Various--Combustion--Environments
Résumé :	Polar solvents are known to swell coal, break hydrogen bonds in the macromolecular structure, and enhance coal liquefaction efficiencies. The effects of the pretreatment of coal using supercritical CO2 on its physical structure and combustion properties have been studied at the bench-scale level. Emphasis has been placed on NO reburning, NO emissions during air-fired and oxy-fired combustion, and loss on ignition (LOI). Pretreatment was found to increase porosity and to significantly alter the fuel nitrogen reaction pathways. Consequently, NO reduction during reburning using bituminous coal increased, and NO emissions during oxidation of lignite decreased. These two benefits were achieved without negative impacts on LOI.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901069k

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10359–10363

Titre :	Study on several mesoporous materials catalysts applied to the removal of trace olefins from aromatics and commercial sidestream tests
Type de document :	texte imprimé
Auteurs :	Chang, Chih-Chen, Auteur ; Deh-Juan Wu, Auteur ; Xian-song Zeng, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10359–10363
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Study--Several--Mesoporous--Materials--Catalysts--Applied--Removal Trace Olefins--Aromatics--Commercial--Sidestream Tests
Résumé :	Deep removal of trace olefins from aromatics using mesoporous materials and modified mesoporous materials was studied with regard to the removal of trace olefins from aromatic hydrocarbons. The mesoporous materials and the modified mesoporous molecular sieve materials were characterized by X-ray diffraction and Fourier transform infrared (FT-IR) spectroscopy. Under the commercial sidestream test, the effects of four types of mesoporous materials, with regard to the removal of olefins from the aromatics, were evaluated. The result showed that the mesoporous materials that had surface areas larger than 300 m2/g and modified with AlCl3 were best, with regard to the effect on the removal of olefins from aromatics. The FT-IR results showed that the modifier could increase the concentration of weak Lewis acid of mesoporous materials and obviously enhance the effect of removing olefins and prolonging the reaction time.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901062c

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10343–10358

Titre :	Coke formation in the transfer line exchanger during steam cracking of hydrocarbons
Type de document :	texte imprimé
Auteurs :	Kevin M. Van Geem, Auteur ; Inge Dhuyvetter, Auteur ; Serge Prokopiev, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10343–10358
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Coke Formation--Transfer--Line Exchanger--during Steam--Cracking --Hydrocarbons
Résumé :	Coke formation under transfer line exchanger conditions, that is, at temperatures from 623 to 873 K and atmospheric pressure, is studied in an electrobalance setup. The coking rate is initially very high (catalytic coking) and drops after a few hours to a constant value. At the studied conditions the observed coking behavior on 15Mo3 alloy pigs can be explained via a catalytic mechanism only, and contributions of the free-radical mechanism and the condensation mechanism are insignificant. Experiments with ethane and naphtha steam cracking effluents and with well-defined reaction mixtures show that the coking rate is independent of the partial pressure of ethene (0−2.7 × 104 Pa), ortho-xylene (0−1.0 × 104 Pa), heavy aromatic hydrocarbons (0−3.0 × 102 Pa), and also 1,3-butadiene (0−2.7 × 104 Pa). The rate of coke deposition depends only on the temperature and the ratio of the partial pressures of water to dihydrogen. The activation energy for initial coke formation was estimated to be ∼90 kJ/mol, a value close to the experimentally determined diffusion energy of carbon in iron.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900124z

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10335–10342

Titre :	Kinetics of cinnamaldehyde hydrogenation by supported ionic liquid catalysts (SILCA)
Type de document :	texte imprimé
Auteurs :	Pasi Virtanen, Auteur ; Tapio Salmi, Auteur ; Jyri-Pekka Mikkola, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10335–10342
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Kinetics--Cinnamaldehyde--Hydrogenation--Supported--Ionic Liquid--Catalysts (SILCA)
Résumé :	The research of ionic liquids and their applications in catalysis are attracting increasing attention in chemistry and chemical engineering. A supported ionic liquid catalyst (SILCA) consists of immobilized catalytic species (e.g., transition-metal particles, metal complexes, or enzymes) residing in an ionic liquid layer immobilized on a porous solid support. The kinetics of cinnamaldehyde hydrogenation over SILCAs that contained palladium nanoparticles in ionic liquid, which, in turn, was immobilized on active carbon cloth (ACC), was studied and modeled in detail. A mechanistic kinetic model, which describes the differences of the activity and selectivity of the catalysts consisting of different ionic liquids, was developed. The model explained the experimental results well.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901041z

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10324–10334

Titre :	Hydrotreatment of fast pyrolysis oil using heterogeneous noble-metal catalysts
Type de document :	texte imprimé
Auteurs :	Jelle Wildschut, Auteur ; Farchad H. Mahfud, Auteur ; Robbie H. Venderbosch, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10324–10334
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Hydrotreatment--Fast Pyrolysis--Oil Using--Heterogeneous--Noble-Metal--Catalysts
Résumé :	Fast pyrolysis oils from lignocellulosic biomass are promising second-generation biofuels. Unfortunately, the application range for such oils is limited because of the high acidity (pH∼2.5) and the presence of oxygen in a variety of chemical functionalities, and upgrading of the oils is required for most applications. Herein, we report an experimental study on the upgrading of fast pyrolysis oil by catalytic hydrotreatment. A variety of heterogeneous noble-metal catalysts were tested for this purpose (Ru/C, Ru/TiO2, Ru/Al2O3, Pt/C, and Pd/C), and the results were compared to those obtained with typical hydrotreatment catalysts (sulfided NiMo/Al2O3 and CoMo/Al2O3). The reactions were carried out at temperatures of 250 and 350 °C and pressures of 100 and 200 bar. The Ru/C catalyst was found to be superior to the classical hydrotreating catalysts with respect to oil yield (up to 60 wt %) and deoxygenation level (up to 90 wt %). The upgraded products were less acidic and contained less water than the original fast pyrolysis oil. The HHV was about 40 MJ/kg, which is about twice the value of pyrolysis oil. Analyses of the products by 1H NMR spectroscopy and 2D GC showed that the upgraded pyrolysis oil had lower contents of organic acids, aldehydes, ketones, and ethers than the feed, whereas the amounts of phenolics, aromatics, and alkanes were considerably higher.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9006003

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10314–10323

Titre :	Computational fluid dynamics study of pulverized coal combustion in blast furnace raceway
Type de document :	texte imprimé
Auteurs :	Y. S. Shen, Auteur ; D. Maldonado, Auteur ; B.Y. Guo, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10314–10323
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Computational--Fluid Dynamics--Pulverized--Coal--Combustion--Blast Furnace--Raceway
Résumé :	In this work, a numerical model is used to study the flow and coal combustion along the coal plume in a large-scale setting simulating the lance−blowpipe−tuyere−raceway region of a blast furnace. The model formulation is validated against the measurements in terms of burnout for both low and high volatile coals. The typical phenomena related to coal combustion along the coal plume are simulated and analyzed. The effects of some operational parameters on combustion behavior are also investigated. The results indicate that oxygen as a cooling gas gives a higher coal burnout than methane and air. The underlying mechanism of coal combustion is explored. It is shown that under the conditions examined, coal burnout strongly depends on the availability of oxygen and residence time. Moreover, the influences of two related issues, i.e. the treatment of volatile matter (VM) and geometric setting in modeling, are investigated. The results show that the predictions of final burnouts using three different VM treatments are just slightly different, but all comparable to the measurements. However, the influence of the geometric setting is not negligible when numerically examining the combustion of pulverized coal under blast furnace conditions.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900853d

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10307–10313

Titre :	Effect of O2 on SO2 reduction with CO or H2 over SnO2−ZrO2 catalyst
Type de document :	texte imprimé
Auteurs :	Gi Bo Han, Auteur ; No-Kuk Park, Auteur ; Tae Jin Lee, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10307–10313
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	O2--SO2--Reduction--CO--H2--SnO2−ZrO2--Catalyst
Résumé :	To investigate the effect of the O2 content on the direct sulfur recovery process (DSRP) combined with the hot gas desulfurization (HGD) process with the unreacted O2 emitted from the regeneration process, either CO or H2 was used as a reducing agent for the reduction of SO2 over SnO2−ZrO2 catalyst with a Sn/Zr molar ratio of 2/1. Then, the reaction conditions, including temperature, CO (or H2)/SO2 molar ratio, and space velocity, were optimized to maximize the sulfur yield in the presence and absence of 1 vol % O2. The temperature, CO (or H2)/SO2 molar ratio, and space velocity were varied in the ranges of 300−600 °C, 1.0−4.0, and 1000−30000 h−1, respectively. In SO2 reduction using CO with 1 vol % O2, the temperature, CO/SO2 molar ratio, and space velocity for the maximum sulfur yield were 600 °C, 3.5, and 10000 h−1, respectively, in which case the SO2 conversion and sulfur yield were about 85% and 77%, respectively. In SO2 reduction using H2 with 1 vol % O2, the temperature, H2/SO2 molar ratio, and space velocity optimized for the maximum sulfur yield were 600 °C, 3.0, and 10000 h−1, respectively, in which case the SO2 conversion and sulfur yield were about 89% and 57%, respectively.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900553s

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10292–10306

Titre :	Characterization and vsible light photocatalytic activity of cerium- and Iron-doped titanium dioxide sol−gel materials
Type de document :	texte imprimé
Auteurs :	Meera Sidheswaran, Auteur ; Lawrence L. Tavlarides, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10292–10306
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Characterization--Visible--Photocatalytic--Cerium--Iron-Doped--Titanium Dioxide--Sol−Gel Materials
Résumé :	Cerium- and iron-based titanium dioxide catalysts are made at varying concentrations and cured at different temperatures to develop a new class of photocatalysts that displays catalytic activity for volatile organic compound destruction when irradiated with visible light. These catalysts are characterized using X-ray diffractometry, Raman spectroscopy, UV−vis diffuse reflectance spectroscopy and BET surface area analyses. The potential of these catalysts to destroy indoor air volatile organics is evaluated using a tubular reactor flow channel with visible light irradiated interior surfaces through which air contaminated with toluene, decane, ethanol, acetaldehyde, or linalool is reacted. It was found that both cerium- and iron-doped titania have lower band-gap energy than pure titania and can be activated with visible light. The anatase and rutile phase transitions of these doped titania is however similar to pure titania and is unaffected by dopants. The crystalinity is however altered and crystal sizes in the range of six to nine nanometers were obtained with the sol−gel type synthesis of the titania catalyst. Although both cerium- and iron-based titania show destruction of these volatile organics in visible light as compared to pure titania, cerium-based titania has better performance than iron-based titania. A photocatalytic oxidation reaction pathway for linalool is proposed on the basis of previous studies and compounds are identified in the exit stream of the reactor. Further, reaction rate constants for toluene, linalool, ethanol, and acetaldheyhde have been determined using a two-dimensional diffusion model (Sidheswaran and Tavlarides, 2008), and are compared with values from literature. It has been found that cerium-doped titania developed in this study performs comparably to the commercially available titania even when irradiated with visible light.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900773m

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10284–10291

Titre :	Investigation of the Enhanced Water Gas Shift Reaction Using Natural and Synthetic Sorbents for the Capture of CO2
Type de document :	texte imprimé
Auteurs :	Christoph R. Müller, Auteur ; Roberta Pacciani, Auteur ; Christopher D. Bohn, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10284–10291
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Investigation--Enhanced--Water Gas--Shift Reaction--Using Natural--Synthetic Sorbents--Capture--CO2
Résumé :	The water gas shift (WGS) reaction was conducted in the presence of two natural and two synthetic CaO-based sorbents. It was shown that such sorbents can affect the WGS in two ways: (i) by catalysis of the reaction and (ii) by altering the equilibrium position by abstraction of CO2 from the gas phase. It was shown that CaO can significantly enhance the production of H2 during the WGS reaction; however, a trade-off between the production of H2 and contamination of the product gas with CO2 (the “CO2 slip”) has to be made. It was found that CaO catalyzes the WGS reaction. The carbonation reaction was very close to thermodynamic equilibrium, even at small contact times at 650 °C. However, the concentration of H2 was significantly below that predicted from equilibrium considerations. In our experiments, once the sorbent had been fully carbonated, it was regenerated by heating to release the CO2 so that it could be reused. In such a cyclic experiment, calcium magnesium acetate, a synthetic sorbent, was the best sorbent tested, albeit only over five cycles of reaction, with respect to the amount of H2 produced. The other sorbents, especially limestone, revealed a decrease in the production of hydrogen with the number of cycles.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900772q

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10277–10283

Titre :	Hybrid modeling of methane reformers. 3 : optimal geometries of perforated catalyst pellets
Type de document :	texte imprimé
Auteurs :	André L. Alberton, Auteur ; Marcio Schwaab, Auteur ; Roberto Carlos Bittencourt, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10277–10283
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Hybrid--Modeling--Methane--Reformers--Optimal--Geometries--Perforated--Catalyst Pellets
Résumé :	This paper studies the optimization of catalyst pellet geometries for the simultaneous maximization of the mechanical strength and catalyst activity of perforated catalyst pellets used for the reforming of methane. This multiobjective problem can be analyzed with the help of Pareto fronts. A previous work (Part 1: Alberton; et al. Ind. Eng. Chem. Res., in press) demonstrated that the effectiveness factor of catalysts with complex geometry used for the reforming of methane can be expressed as a linear function of the specific area of the pellet; consequently, catalyst activity can be expressed in terms of the geometric parameters of the pellet. It can also be assumed that the mechanical strength of perforated catalyst pellets is related to the minimum wall thickness of the solid piece. Therefore, two optimization problems can be proposed: (i) the simultaneous maximization of the specific area and of the minimum wall thickness of the pellet and (ii) the simultaneous maximization of the overall catalyst activity in the catalyst bed and of the minimum wall thickness of the pellet. These objective functions are evaluated here for several catalyst geometries and analyzed with a Pareto filter. The Pareto fronts obtained for the two analyzed cases are essentially the same, indicating that the maximization of the specific area constitutes a useful criterion for design of perforated catalysts in diffusion-controlled systems. Optimized catalyst geometries are presented for different catalyst designs and can be used as references for future manufacture of catalyst pellets.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9001662

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10268–10276

Titre :	Investigation of physicochemical parameters that influence photocatalytic degradation of methyl orange over TiO2 nanotubes
Type de document :	texte imprimé
Auteurs :	York R. Smith, Auteur ; Archana Kar, Auteur ; Vaidyanathan (Ravi) Subramanian, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10268–10276
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Investigation--Physicochemical--Parameters--Influence--Photocatalytic--Degradation--Methyl--Orange--TiO2 Nanotubes
Résumé :	The photocatalytic degradation of a model textile dye, methyl orange (MO), using anodized titanium dioxide (TiO2) nanotubes has been investigated. The effects of light intensity, dye concentration, external bias, pH, and nanotube dimensions (length, diameter, and wall thickness) on MO photodegradation have been examined. The application of a minimal bias of +0.0 versus saturated calomel electrode (SCE) can enhance the dye degradation at least 10 times compared to unbiased conditions for dye concentrations between 20 and 100 μM. The overall initial dye degradation rate demonstrates three types of dependence on dye concentration over a range from 2.5−100 μM. For lower dye concentrations (2.5−40 μM) and natural pH (∼6.0) conditions, Langmuir−Hinshelwood (LH) kinetics was observed. The nanotubes diameter, calcination condition, and the anatase-to-rutile ratio in the crystalline TiO2 nanotubes together influence the photocatalytic and photoelectrochemical properties of the TiO2 nanotubes.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie801851p

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10262–10267

Titre :	Photocatalytic degradation of methylene blue dye using ultraviolet light emitting diodes
Type de document :	texte imprimé
Auteurs :	Rajesh J. Tayade, Auteur ; Thillai Sivakumar Natarajan, Auteur ; Hari C. Bajaj, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10262–10267
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Photocatalytic--Degradation--Methylene--Blue Dye--Using--Ultraviolet--Emitting Diodes
Résumé :	This study was focused on the application of ultraviolet light emitting diodes (UV-LED) as an alternate source for the photocatalytic degradation of methylene blue (MB), which was used as a model compound. A simple reactor arrangement was made to carry out the photocatalytic degradation of methylene blue dye. The photocatalytic activity of P-25 Degussa TiO2 was evaluated using UV-LED reactor. The decomposition of MB dye in aqueous solution by TiO2 photocatalytic process with the UV-LED was found to be technically feasible. The effects of various parameters such as catalyst loading, initial dye concentration, pH, and addition of H2O2 on decolorization and degradation have been investigated to find the optimum conditions. The complete mineralization of MB dye (3.12 × 10−5 M) was confirmed by chemical oxygen demand analysis. Results demonstrated that the UV-LED/TiO2 process can effectively degrade methylene blue dye with optimum conditions.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9012437

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10253–10261

Titre :	Industrial investigation on the origin of sulfur in fluid catalytic cracking gasoline
Type de document :	texte imprimé
Auteurs :	Dicho S. Stratiev, Auteur ; Ivelina hishkova, Auteur ; Todor zingov, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10253–10261
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Industrial--Investigation--Origin--Sulfur--Fluid--Catalytic--Cracking--Gasoline
Résumé :	Industrial experiments on the addition of H2S to the fluid catalytic cracking (FCC) feed (hydrotreated vacuum gas oil) were carried out in the commercial FCC unit at Lukoil Neftochim, Bulgaria. It was found that during cracking of pure hydrotreated vacuum gas oil to which was added about 550 ppm H2S that the FCC gasoline contained about 12 ppm more sulfur than the nonspiked feed. Both gasolines obtained from the pure feed and the H2S-spiked feed contained the same type of sulfur compounds: mercaptans, thiophenes, and benzothiophenes. In the case of the H2S-spiked feed, the additional FCC gasoline sulfur formed was about 1.2% of the sulfur in the H2S added to the feed. The FCC gasoline sulfur formed from the pure FCC feed, on the other hand, was about 2.5% of the sulfur in the feed. The higher percent of sulfur conversion of the pure FCC feed relative to the conversion of the H2S suggests that both reaction of H2S with olefins or diolefins (from the catalytic cracking of the hydrocarbons of the feed) and transformation of heavy sulfur compounds contained in the feed may be responsible for the entire FCC gasoline sulfur compounds formation.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900985g

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10247–10252

Titre :	Influence of water quality on the efficiency of retention aids systems for the paper industry
Type de document :	texte imprimé
Auteurs :	Ruth Ordóñez, Auteur ; Daphne Hermosilla, Auteur ; Elena de la Fuente, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10247–10252
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Influence--Water--Quality--Efficiency--Retention--Systems--Paper--Industry
Résumé :	It has been reported that about 10−15% of the fresh water intake in a paper mill is used for feeding and diluting retention aids, so significant savings could be achieved by replacing fresh water with process water. Water from different sources and qualities—fresh water, the outflow from an internal ultrafiltration placed in the machine circuit of a paper mill, and water from a membrane bioreactor used to treat the final effluent of this paper mill—were used to prepare a dual retention system consisting of a cationic polyacrylamide and bentonite. While the behavior of bentonite was not significantly affected by the quality of the water used in its preparation, the efficiency of the cationic polyacrylamide was reduced to about 12% when it was prepared with water with high anionic trash content and conductivity as a result of a partial neutralization of the charged groups. The effect of nonionic chemical oxygen demand on the efficiency of the polymer was negligible.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9010029

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10240–10246

Titre :	Reductive Precipitation of Elemental Selenium from Selenious Acidic Solutions Using Sodium Dithionite
Type de document :	texte imprimé
Auteurs :	Nicolas Geoffroy, Auteur ; George P. Demopoulos, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10240–10246
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Reductive--Precipitation--Elemental--Selenium--Selenious--Acidic--Solutions--Using Sodium--Dithionite
Résumé :	In this work, the batch-reactor reduction of selenious acid (H2SeO3) species with sodium dithionite (Na2S2O4) from weakly acidic sulfate solutions containing 300 mg/L of selenium at 23 οC was studied. The results showed that, at an initial pH value of <1.7 and a dithionite stoichiometric excess of >3, <0.5 μg/L of selenium(IV) remained in solution after reduction. The reductive precipitation reaction started as soon as dithionite was added in the selenium-bearing solution and was completed within less than a minute. However, it was determined that the precipitate was not stable in the presence of the dithionite decomposition byproduct and partially redissolved after several hours. The reaction product, characterized using X-ray diffraction, scanning electron microscopy, and chemical analysis, was determined to be red amorphous selenium. The precipitate, in addition to elemental selenium, was determined to contain monoclinic sulfur that was apparently formed via a side reaction pathway involving the decomposition of dithionite.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9008502

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10234–10239

Titre :	Liquid-phase hydrogenation of crotonaldehyde over platinum- and palladium-based catalysts
Type de document :	texte imprimé
Auteurs :	Betiana C. Campo, Auteur ; María A. Volpe, Auteur ; Carlos E. Gigola, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10234–10239
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Liquid-Phase--Hydrogenation--Crotonaldehyde--Platinum--Palladium-Based--Catalysts
Résumé :	The selective hydrogenation of crotonaldehyde in liquid phase, at a temperature of 353 K and a H2 pressure of 400 kPa, is studied over different palladium- and platinum-based catalysts (Pd−Pb/α-Al2O3, Pd−Zn/α-Al2O3, Pd/ZnO, and two Pt/ZnO samples, prepared from Pt(NH3)4(NO3)2 and H2PtCl6, respectively). The intrinsic selectivity of palladium cannot be modified by alloying or following a promotion with a second metal, and the selectivity to crotyl alcohol measured over palladium-based samples is nil or extremely low. The selectivity corresponding to the Pt/ZnO catalysts increases with the time-on-stream reaching high levels. The formation of a Pt−Zn alloy is the origin of the enhanced selectivity toward crotyl alcohol; this effect is more pronounced for the sample that has been prepared from H2PtCl6.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901217r

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10222–10233

Titre :	Influence of secondary reactions on the heat of pyrolysis of biomass
Type de document :	texte imprimé
Auteurs :	Claudia Gomez, Auteur ; Enric Velo, Auteur ; Federica Barontini, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10222–10233
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Influence--Secondary--Reactions--Heat--Pyrolysis--Biomass
Résumé :	The thermal behaviors during the pyrolysis of two different biomass samples, beech wood from carpentry residuals and artichoke thistle from energy-dedicated crops, were investigated. Thermogravimetry/differential scanning calorimetry (TG-DSC) and thermogravimetry coupled to Fourier transform infrared (TG-FTIR) analysis of evolving products were used to investigate the thermal effects of the pyrolysis process. The role of pretreatments (hot-water washing, ethanol extraction, and their combination) was also analyzed. High alterations in the heat demand were observed as a function of the initial sample mass and pyrolysis conditions. The role of vapor−solid secondary interactions was evidenced by the evolution profiles of the main pyrolysis products.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9007985

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10217–10221

Titre :	Regiospecific epoxidation of carvone α,β-unsaturated ketone group with a basic resin
Type de document :	texte imprimé
Auteurs :	María A. Uguina, Auteur ; José A. Delgado, Auteur ; José Carretero, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10217–10221
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Regiospecific--Epoxidation--Carvone α,β-Unsaturated--Ketone Group--Basic Resin
Résumé :	A basic resin in OH− form (Amberlite IRA-900) has been used to catalyze the regiospecific epoxidation of carvone with H2O2 to obtain 5,6-epoxycarvone, showing high activity and selectivity (>99%). The effects of solvent, temperature, stirring rate, catalyst loading, oxidant/substrate ratio, and oxidant dosage have been analyzed. A second-order kinetic model has been proposed to describe the effect of substrate concentration, catalyst loading, and temperature on reaction rate, and the apparent activation energy of the reaction has been estimated. The catalyst has been tested in five consecutive runs and it has shown to be completely reusable after regeneration of its hydroxyl groups before each use.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9010723

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10211–10216

Titre :	Photochemical degradation of 2,4,6-trichlorophenol in the brij 35 micellar solution : pH control on product distribution
Type de document :	texte imprimé
Auteurs :	W. Chu, Auteur ; Y. F. Rao, Auteur ; C. Y. Kwan, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10211–10216
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Photochemical--Degradation--Trichlorophenol--Brij 35 Micellar--Solution--pH Control--Product Distribution
Résumé :	Surfactants have been used for separating organic pollutants from contaminated soils in soil-washing process. The extracted pollutants can be effectively degraded upon UV irradiation in the presence of surfactant micelles. The photodecay rate of 2,4,6-trichlorophenol (2,4,6-TCP) by UV light at 253.7 nm and photonic efficiency of 2,4,6-TCP degradation reaction were investigated at different pH levels with the addition of nonionic surfactant solutions above the critical micelle concentration (cmc). A continual examination on intermediates at all pHs was conducted and photochemical processes induced the dechlorination of TCP to form di- and monochlorinated intermediates and phenol. An additional reaction was observed when the initial pH level was above neutral, at which chlorinated hydroquinones were the resulting intermediates through photohydrolysis process. Two reaction mechanisms, one at acidic and the other at basic conditions, were proposed and verified by the evidence presented in this study.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9003943

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10206–10210

Titre :	Voltammetric oxidation and determination of atenolol using a carbon paste electrode
Type de document :	texte imprimé
Auteurs :	Roopa H. Patil, Auteur ; Rajesh N. Hegde, Auteur ; S. T. Nandibewoor, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10206–10210
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Voltammetric--Oxidation--Determination--Atenolol--Using--Carbon--Paste--Electrode
Résumé :	The electrochemical oxidation of atenolol, an antihypertensive drug, was studied in a phosphate medium at a carbon paste electrode. Cyclic voltammetric results showed one well-defined oxidation peak in the potential range from 0.2 to 1.2 V under different pH conditions, but the best results were obtained at pH 10.4. The oxidation was irreversible and exhibited diffusion-controlled behavior. The response was evaluated with respect to pH and scan rate. The number of electrons transferred in the oxidation process was calculated, and the probable oxidation mechanism was proposed. The proposed differential pulse voltammetric method was successfully applied to atenolol determination in pharmaceutical samples. The analytical performance of this method has been evaluated for detection of analyte in urine as a real sample.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901163k

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10196–10205

Titre :	Recent Developments in the Use of Layered Double Hydroxides as Host Materials for the Storage and Triggered Release of Functional Anions
Type de document :	texte imprimé
Auteurs :	Aamir I. Khan, Auteur ; Anusha Ragavan, Auteur ; Bonnie Fong, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10196–10205
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Recent--Developments--Layered--Double--Hydroxides--Materials--Storage--Triggered--Release--Functional Anions
Résumé :	An extensive and systematic study of the intercalation of a number of commercially important anions into a range of layered double hydroxides (LDHs) has been undertaken. A pseudo-combinatorial approach was employed to determine rapidly the ideal reaction conditions for the intercalation of each guest. Over 50 LDH nanohybrids are reported, the vast majority of them having never previously been synthesized. Guest anions include key drugs, important agrochemicals, vitamins, fragrances, a dye, and a color fixant. The immense potential of LDH systems as reservoirs and to remove agrochemical pollutants from effluvium flows was demonstrated. The release of the guest anions was studied in representative conditions. Some of the thiosulfate intercalates show temperature programmable release characteristics which have not be observed previously.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9012612

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10190–10195

Titre :	Influence of Soda−Air−AQ Pulping of Straw on Silica Precipitation, Paper Strength, and Performance of CPVA as a Dry Strength Additive
Type de document :	texte imprimé
Auteurs :	Pedram Fatehi, Auteur ; Ahmet Tutus, Auteur ; Yonghao Ni, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10190–10195
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Influence--Soda−Air−AQ--Pulping--Straw--Silica--Precipitation--Paper Strength--Performance--CPVA--Strength Additive
Résumé :	In this study, the impact of soda−air−anthraquinone (AQ) pulping conditions on delignification and silica precipitation onto pulp fibers and paper sheets was studied. The results showed that the yield and silica precipitation slightly increased upon application of AQ in soda−air pulping. Scanning electron microscopy (SEM) and elemental analysis confirmed the deposition of silica-related particles on fibers and on paper sheets for both soda−air and soda−air−AQ pulping. Furthermore, increasing the cooking temperature had a stronger impact on delignification and silica deposition than did increasing the cooking time for soda−air−AQ pulping. In another set of experiments, the influence of cationic poly(vinyl alcohol) (CPVA) with two different molecular weights on improving the strength properties of straw pulps produced under various soda−air−AQ pulping conditions was studied. The adsorption of CPVA onto straw pulp and its effect on silica retention for paper sheets were comprehensively investigated.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901273m

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10186–10189

Titre :	Effect of dioxygen partial pressure on ligand degradation in chelated Iron dehydrosulfurization processes
Type de document :	texte imprimé
Auteurs :	Stephen A. Bedell, Auteur ; Clare M. Worley, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10186–10189
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Effect--Dioxygen--Partial--Pressure--Ligand--Degradation--Chelated--Iron--Dehydrosulfurization--Processes
Résumé :	Chelated iron processes such as LO-CAT and SulFeroxSM utilize ferric chelate solutions for the oxidation of hydrogen sulfide to form aqueous suspensions of sulfur. During the ferrous chelate reoxidation, dioxygen reduction intermediates are believed to initiate oxidative degradation reactions of the aminocarboxylate ligands used in the process. This study shows that the same degree of Fe(II) oxidation (regeneration) can be achieved with reduced ligand degradation by decreasing the rate at which O2 is supplied to a reactor. This apparent mass transfer limited degradation is explained in terms of dioxygen reduction intermediate formation and reactions. A model for bubble column regeneration was used to predict local partial pressures of dioxygen for a number of reactor configurations. Such analysis predicts several changes in regenerator design which could substantially reduce the amount of chemical usage in such a process. Changes include reduction of the stoichiometric excess of air, use of multiple reactors, and recycling of spent air.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900904s

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10180–10185

Titre :	Rice polish : an alternative to conventional adsorbents for treating arsenic bearing water by Up-flow column method
Type de document :	texte imprimé
Auteurs :	D. Ranjan, Auteur ; M. alat, Auteur ; S. H. Hasan, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10180–10185
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Rice Polish--Alternative--Conventional--Adsorbents--Treating--Arsenic--Bearing--Up-Flow Column Method
Résumé :	“Rice polish”, an agrowaste from rice milling industries, was utilized as potential biosorbent for removal of arsenic from water in a continuous up-flow fixed bed column system. The experiments were conducted to study the effect of important design parameters such as bed height, flow rate, and initial metal ion concentration. At a bed height of 25 cm, flow rate 1.66 mL/min, and initial metal ion concentration 1000 μg/L, the metal uptake capacity of rice polish for As(III) and As(V) was found to be 66.95 and 78.95 μg/g, respectively. The bed depth service time (BDST) model was used to analyze the experimental data. The computed sorption capacity (No) was 28776 and 28248 μg/L for As(III) and As(V), respectively. The rate constant (Ka) was recorded as 0.117 × 10−3 and 0.26 × 10−4 (L/μg)/min for As(III) and As(V), respectively. The column regeneration studies were carried out using 10% NaOH as eluant for three sorption−desorption cycles. The high arsenic removal ability and regeneration efficiency of this biosorbent suggest its applicability in industrial processes and data generated would help in further upscaling of the adsorption process.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900877p

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10169–10179

Titre :	Corrosion Behavior of Carbon Steel in the Monoethanolamine−H2O−CO2−O2−SO2 System: Products, Reaction Pathways, and Kinetics
Type de document :	texte imprimé
Auteurs :	Nattawan Kladkaew, Auteur ; Raphael Idem, Auteur ; Paitoon Tontiwachwuthikul, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10169–10179
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Corrosion Behavior--Carbon Steel--Monoethanolamine−H2O−CO2−O2−SO2--System--Products--Reaction--Pathways--Kinetics
Résumé :	This work investigates the effect of operating parameters on corrosion products, reaction pathways, and kinetics for the corrosion of carbon steel in the monoethanolamine−H2O−CO2−O2−SO2 system. Corrosion experiments were conducted using a 273A potentiostat unit under conditions in which monoethanolamine (MEA), O2, and SO2 concentrations and CO2 loading were in the range of 1−7 kmol/m3, 0−100%, 0−204 ppm, and 0−0.5 mol CO2/mol MEA, respectively, at corrosion temperatures of 303−353 K to mimic the absorption−regeneration sections. Analysis, performed for this system for the first time, shows that corrosion products generated from the effect of SO2 include FeSO4 and Fe2O3·H2O. Also, a higher concentration of SO2 in simulated flue gas stream induces a higher corrosion rate because of the increase in the hydrogen ion concentration generated by reactions of SO2 and H2O as well as SO2, O2, and H2O. A power-law model developed to correlate corrosion rate with the parameters in the MEA−H2O−CO2−O2−SO2 system shows that corrosion rate of carbon steel increases with an increase in O2 and SO2 concentrations in simulated flue gas stream, as well as MEA concentration, CO2 loading, and operating temperature. It was observed that CO2 loading had the highest impact on the corrosion rate, while SO2 and O2 show only slight effects on the corrosion rate.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900877p

[article]
in Industrial & engineering chemistry research > Vol. 48 N° 23 (Décembre 2009) . - pp. 10163–10168

Titre :	Trimethylamine-modified lignophenol for the recovery of precious metals
Type de document :	texte imprimé
Auteurs :	Durga Parajuli, Auteur ; Koichi Hirota, Auteur ; Katsutoshi Inoue, Auteur
Année de publication :	2010
Article en page(s) :	pp. 10163–10168
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Trimethylamine-Modified--Lignophenol--Recovery--Precious--Metals
Résumé :	A quaternary amine-type sorbent has been prepared by the immobilization of trimethylamine group onto the cross-linked lignophenol matrix. The sorption behavior for a number of metal ions was studied in hydrochloric acid medium. From the batch test of individual metal ion as well as the mixture solution containing equal molar concentration of various metal ions, the sorbent was found to hold selectivity for Au(III), Pd(II), and Pt(IV) ions only with negligible sorption for other metal ions like Cu(II), Co(II), Fe(III), Ni(II), and Zn(II). The sorption kinetics was studied at 30, 50, and 65 °C and elucidated the order of sorption of Au(III), Pd(II), and Pt(IV) and from the values of rate constants at different temperatures, the energy of activation has been evaluated. The sorption isotherm study revealed the Langmuir type sorption and from the Langmuir charts the maximum loading capacity of Au(III), Pd(II), and Pt(IV) has been evaluated.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie801829w

Industrial & engineering chemistry research / Paul, Donald R. . Vol. 48 N° 23

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