Catalogue en ligne Bibliothèque Ecole Nationale Polytechnique d'Alger

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5952–5957

Titre :	Solubility model of solid solute in supercritical fluid solvent based on UNIFAC
Type de document :	texte imprimé
Auteurs :	Yueqiang Zhao, Auteur ; Weiwei Liu, Auteur ; Zhengming Wu, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5952–5957
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	UNIFAC Semitheoretical model based Supercritical fluid (SF) solvent Vapor−liquid equilibrium
Résumé :	A semitheoretical model based on UNIFAC was proposed to correlate the solubility of solid solute in supercritical fluid (SF) solvent simply and reliably, which does not need critical parameters for solid solutes. The interaction parameters aij between the SF solvents (such as carbon dioxide, ethylene, and ethane) and the functional groups of solutes were regressed, which is compatible with the vapor−liquid equilibrium (VLE) UNIFAC group-interaction parameters. More efforts and experimental data are needed to obtain a sufficiently large number of interaction parameters for extensive applications. The estimated power exponent of reduced density seems identical for the same solid solute in SF cosolvent homologues. This model could predict the solubility of a solid solute in supercritical CO2 with cosolvents successfully.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100656v

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5945–5951

Titre :	Enhanced fiber quality of black spruce (Picea mariana) thermomechanical pulp fiber through selective enzyme application
Type de document :	texte imprimé
Auteurs :	Marc J. Sabourin, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5945–5951
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Black Spruce Thermomechanical pulping Enzyme application
Résumé :	Two different enzyme applications were applied to black spruce thermomechanical pulping (TMP) in an attempt to selectively enhance the physical properties of the resulting pulp. Past studies have revealed some application difficulties between pulp and enzymes. A new method of enzyme application including fiberizing the wood chips and cooling the fiberized material prior to enzyme application was employed to maximize the fiber surface area available for enzyme reaction and to obtain optimal enzyme reaction temperatures. Fiberized chips are chips that have been destructured in a converging screw chip press followed by low energy refining to produce extremely coarse fiber pulp. TMP pulps obtained from a control sample of whole wood chips, fiberized wood treated with water, and fiberized wood with two different enzyme applications were evaluated for specific refining energy and various physical properties. Scanning electron microscopy (SEM) in conjunction with image analysis techniques was used to determine fiber wall thickness, degree of fiber fibrillation, and percent surface disruption for selected trial pulps. One monocomponent pectinase enzyme evaluated in this work was found to significantly improve various physical properties and increase the specific surface area of the resulting pulp. The multicomponent more aggressive pectinase enzyme evaluated was determined to be less effective at enhancing physical properties than the less aggressive monocomponent enzyme. The new fiberizing application method employed prior to enzyme application was found to reduce the specific refining energy requirements by 7%. When evaluated at a constant freeness, the enzyme treatment in conjunction with the new application method was found to reduce specific refining energy by about 9%. The enzyme application had only minimal impact on energy requirements. The enzyme application did significantly enhance the tensile and tear index of the resulting pulp. Dramatic increases in the amount of fibrillation and fiber surface disruption were also found to result from specific enzyme action upon the fiber. The resulting fiber wall thickness was reduced as a result of the enzyme action as well. Results from this work reveal that selective enzyme application is an effective method for enhancing specific physical properties of TMP pulps.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100681e

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5939–5944

Titre :	Energy estimation on CRN process of fly ash as a slow-release nitrogen fertilizer
Type de document :	texte imprimé
Auteurs :	Qi Qiu, Auteur ; V. Hlavacek, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5939–5944
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Carbothermal reduction and nitridation Nitrogen fertilizer
Résumé :	Through carbothermal reduction and nitridation (CRN) reaction, nitrogen could be fixed into fly ash up to 28 wt %. Nitrided fly ash has the potential to be a source of slow release nitrogen fertilizer. To further investigate this potential, the energy consumptions were estimated for the nitridation process of fly ash. Reactors such as parallel rotary furnaces were simulated for the heat loss of radiation and convection. Material balance was carried out to determine the dimension of the rotary furnaces. Subsequently, on the basis of the dimension of the rotary furnace, the energy balance was performed from the reaction engineering aspects of the nitridation reaction of fly ash. Ultimately, the total energy was transformed into per unit nitrogen and compared with the energy consumption of the Haber−Bosch process for ammonia synthesis. The energy balance calculation suggested that there is great potential for nitrided fly ash to be slow release nitrogen fertilizer.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100391y

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5933–5938

Titre :	Continuity control of b-oriented MFI zeolite films by microwave synthesis
Type de document :	texte imprimé
Auteurs :	Xianming Li, Auteur ; Yushan Yan, Auteur ; Zhengbao Wang, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5933–5938
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	b-oriented MFI zeolite films Crystallization
Résumé :	Influences of aging and crystallization conditions on the continuity of b-oriented MFI zeolite films on stainless steel substrates are systematically investigated. A long aging time (e.g., 20 h) at room temperature is needed to obtain a continuous b-oriented MFI zeolite film by the microwave heating at 165 °C. However, the aging time can be shortened from 20 h to 30 min by elevating the aging temperature to 80 °C. Compared with the conventional heating (2 h), continuous b-oriented MFI zeolite films are prepared on stainless steel substrates with a much shorter crystallization time by the microwave heating (35 min). Continuous b-oriented MFI zeolite films can be synthesized by controlling nuclei concentration and crystal size, which are mainly determined by the conditions of the aging and crystallization respectively. On the basis of the results from these experiments, a film continuity−synthesis condition map is obtained and a film formation mechanism is discussed.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie1000136

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5925–5932

Titre :	Effect of experimental conditions on measuring autoignition temperatures of liquid chemicals
Type de document :	texte imprimé
Auteurs :	Chan-Cheng Chen, Auteur ; Yen-Cheng Hsieh, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5925–5932
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Autoignition temperature
Résumé :	The principal application of autoignition temperature (AIT) is to define the maximum acceptable surface temperature in a particular area, usually for electrical classification purpose. However, although AITs are indispensable information for safely handling flammable liquids, the reported AITs of flammable liquids in different data compilations are very much diverse. Sometimes, the difference in separate data compilations might up to more than 300 K. This article aims to explore the quantitative effects of flask material, ambient temperature, and ambient humidity on the accuracy for measuring AIT via the method of ASTM E659. To effectively analyze these factors simultaneously, the L9(34) orthogonal arrays are used to allocate experiments, and experiments are then carefully conducted in a temperature- and humidity-controlled laboratory chamber. It is found that ambient humidity does not affect the measured AIT of ethanol, but both flask material and ambient temperature are significant factors in measuring AIT of ethanol. An experiment of measuring AIT of ethanol conducted with a flask material of quartz is found to result in a higher AIT value than the one conducted with a flask material of borosilicate by 20 °C. A quadratic relation between the measured AIT of ethanol (y) and the ambient temperature (x) is found, and it is also found that a quadratic polynomial of y = 3.450 × 10−2 x2 − 1.454x + 3.711 × 102 could properly fit this relation with R2 = 0.9939. According to aforementioned quadratic relation, the ambient temperature at which the lowest AIT of ethanol appears is about 21 °C.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9020649

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5911–5924

Titre :	Comparison of high resolution schemes for solving population balances
Type de document :	texte imprimé
Auteurs :	Ala Eldin Bouaswaig, Auteur ; Sebastian Engell, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5911–5924
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Population balance equation High resolution discretization methods
Résumé :	The physical properties of particulate products such as crystals and polymers are strongly dependent on their size distribution which is usually modeled by a population balance equation (PBE). The PBE is an integro-partial differential equation and due to its hyperbolic nature, steep fronts are encountered in the solution profile. When solved numerically, the discretization of the PBE has to be performed with care to avoid numerical diffusion, and dispersion and appropriate numerical methods have to be chosen for that purpose. In this work, an extensive investigation of the performance of several high resolution discretization methods when applied to the PBE is performed with the objective to determine the most promising among them in terms of accuracy and computation time. The comparison is performed on standard benchmark problems and on a practical PBE that arises from modeling the growth of a seed of particles in emulsion polymerization.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9020057

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5900–5910

Titre :	Numerical simulation of pneumatic dryers using computational fluid dynamics
Type de document :	texte imprimé
Auteurs :	Tarek J. Jamaleddine, Auteur ; Madhumita B. Ray, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5900–5910
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Hydrodynamic mechanism Drying mechanisms Gas-solid flow Fluid dynamics
Résumé :	The hydrodynamic and drying mechanisms of a dilute-phase, gas-solid flow have been predicted in a laboratory and a large-scale pneumatic dryer. A computational fluid dynamics (CFD) method based on the two-fluid multiphase flow model has been adopted. A control-volume based technique implemented in the FLUENT CFD package was applied along with the kinetic theory of granular flow (KTGF) to simulate the flow pattern and heat and mass transfer processes for wet PVC and sand particles by hot air. The mass-weighted averages of theoretical predictions for temperature and moisture content agree well with the experimental data for similar models. User-defined subroutines were added to extend FLUENT capability to account for mixture properties and to simulate the drying rate for surface moisture evaporation and moisture diffusion inside the particulate phase. The present model can be extended to simulate the drying of various temperature sensitive materials.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901816s

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5891–5899

Titre :	Magnetic resonance studies of fluidization regimes
Type de document :	texte imprimé
Auteurs :	D. J. Holland, Auteur ; C. R. Müller, Auteur ; J. S. Dennis, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5891–5899
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Magnetic resonance Gas-fluidized bed
Résumé :	Measurements of the voidage and velocity distributions in a gas-fluidized bed operating in the bubbling, turbulent, and core−annular fluidization regimes were acquired using magnetic resonance imaging (MR). The bed studied was contained in a column 50 mm in diameter and was fluidized with air. The particles were silica−alumina catalyst support loaded with water doped with gadolinium (diameter 63 μm, density of the water loaded particles 1530 kg m−3). Both time-averaged and ultrafast measurements are presented and provide the first noninvasive measurements of the velocities of particles and local voidage in a fluidized bed in each of the flow regimes. Measurements of the pressure fluctuations were also recorded as a function of the superficial velocity of the fluidizing gas to compare with the MR measurements. Ultrafast measurements of the voidage were used to examine the void structures present in the different flow regimes and to provide a means of studying the dynamics. A novel MR technique was used to measure the velocities of the particles in a diametral region of 15 mm × 15 mm square cross-section through the center of the bed every 7.7 ms. These measurements confirmed that the highest particle velocities in the bubbling fluidization regime occurred in the wakes of bubbles. The distribution of particle velocities in a bubbling bed is highly skewed; however, it approaches a Gaussian distribution and appears to scale with the superficial gas velocity in the turbulent fluidization regime. Finally, a simple model to infer the slip velocity in core−annular fluidization indicates that the particles in the center of the column group together in clusters with a diameter of between 4 and 8 particles.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901450q

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5884–5890

Titre :	Effects of monoethylene glycol on carbon dioxide partitioning in gas/monoethylene glycol/water/salt mixed systems
Type de document :	texte imprimé
Auteurs :	Amy T. Kan, Auteur ; Haiping Lu, Auteur ; Mason B. Tomson, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5884–5890
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Carbon dioxide partitioning Gas/liquid equilibrium NaCl−H2O−monoethylene glycol (MEG) mixed solvent
Résumé :	This paper extended the experimental results of carbon dioxide partitioning in gas/liquid equilibrium with a NaCl−H2O−monoethylene glycol (MEG) mixed solvent. The experiments were conducted systematically at 3−70 °C, 0−6.0 m NaCl, and 0−99 wt % MEG concentrations. CO2 partitioning to the NaCl−H2O−MEG solution is complicated due to nonideal behavior in the solvent. A self-consistent activity model is proposed to describe the effect of monoethylene glycol (MEG) on CO2 partitioning in gas/MEG/water/salt solutions using pure H2O as the reference state. Pitzer theory was used to calculate the effect of salt, and a semiempirical equation was applied to correlate the effects of MEG at different temperatures and ionic strengths. The equation is applicable to CO2 partitioning at 0−6 mol of NaCl and 0−97% MEG mixed solution at 0−90 °C. This model can be incorporated with Pitzer type activity coefficient models to predict the solubility of carbon dioxide in the presence of MEG and salt solutions.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901274v

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5877–5883

Titre :	Stagnation point offset of two opposed jets
Type de document :	texte imprimé
Auteurs :	Zhi-gang Sun, Auteur ; Wei-feng Li, Auteur ; Hai Feng Liu, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5877–5883
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Axial velocity Stagnation point offset Impinging streamsSmoke wire visualization Hot-wire anemometry techniques
Résumé :	The axial velocity and the stagnation point offset of impinging streams from two opposed nozzles have been theoretically studied and experimentally measured by smoke wire visualization and hot-wire anemometry (HWA) techniques. The results show that, for small nozzle separation (L/D < 2), the equations based on Reynolds stress theory can be used to predict the stagnation point offset for two nozzles of the same size. For middle nozzle separation (2 ≤ L/D ≤ 12), the stagnation position is very sensitive to the exit velocity ratio and that it changes nonlinearly with increasing nozzle separation. For large nozzle separation (L/D > 12), the equations based on the free jet theory can be used to predict the stagnation point offset for two nozzles of the same and different sizes. The illustrated effects of the exit momentum ratio and the nozzle separation on the stagnation point offset are useful for defining the optimum conditions for many industrial applications of the opposed jets.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901056x

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5869–5876

Titre :	Highly water-soluble magnetic nanoparticles as novel draw solutes in forward osmosis for water reuse
Type de document :	texte imprimé
Auteurs :	Ming Ming Ling, Auteur ; Kai Yu Wang, Auteur ; Tai-Shung Chung, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5869–5876
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Magnetic nanoparticles Highly water-soluble magnetic nanoparticles
Résumé :	Highly hydrophilic magnetic nanoparticles have been molecularly designed. For the first time, the application of highly water-soluble magnetic nanoparticles as novel draw solutes in forward osmosis (FO) was systematically investigated. Magnetic nanoparticles functionalized by various groups were synthesized to explore the correlation between the surface chemistry of magnetic nanoparticles and the achieved osmolality. We verified that magnetic nanoparticles capped with polyacrylic acid can yield the highest driving force and subsequently highest water flux among others. The used magnetic nanoparticles can be captured by the magnetic field and recycled back into the stream as draw solutes in the FO process. In addition, magnetic nanoparticles of different diameters were also synthesized to study the effect of particles size on FO performance. We demonstrate that the engineering of surface hydrophilicity and magnetic nanoparticle size is crucial in the application of nanoparticles as draw solutes in FO. It is believed that magnetic nanoparticles will soon be extensively used in this area.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100438x

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5863–5868

Titre :	Extraction of tetra-oxo anions into a hydrophobic, ionic liquid-based solvent without concomitant ion exchange
Type de document :	texte imprimé
Auteurs :	Dominique C. Stepinski, Auteur ; George F. Vandegrift, Auteur ; Ilya A. Shkrob, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5863–5868
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Ionic liquids Tetra-oxo anions
Résumé :	Hydrophobic ionic liquids (IL) have the potential to simplify certain separations by serving as both an extraction solvent and an electrolyte for subsequent electrochemical reductions. While IL-based solvents are known to be efficient media for metal ion extraction, separations employing these solvents are frequently complicated by the loss of constituent IL ions to the aqueous phase, resulting in deteriorating performance. In this study, we have examined the extraction of pertechnetate and related tetra-oxo anions from aqueous solutions into IL-based solvents incorporating tetraalkylphosphonium bis[(trifluoromethyl)sulfonyl]imide and a crown ether. In contrast to various previously studied IL-based cation extraction systems, facile anion extraction without significant transfer of the IL ions to the aqueous phase has been observed. In addition, the solvents exhibit high distribution ratios (100−500 for pertechnetate), significant electrical conductivity (>100 μS/cm), and a wide (∼4 V) electrochemical window. The results suggest that these solvents may provide the basis for improved approaches to the extraction and recovery of a variety of anions.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie1000345

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5854–5862

Titre :	Precipitation and transformation of the three polymorphs of d-mannitol
Type de document :	texte imprimé
Auteurs :	Jeroen Cornel, Auteur ; Piran Kidambi, Auteur ; Mazzotti, Marco, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5854–5862
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	d-mannitol’s three polymorphs Thermodynamic aspects kinetic aspects Solid-state forms
Résumé :	In this work, the thermodynamic and kinetic aspects of d-mannitol’s three polymorphs and their transformations are addressed. Scalable and reproducible syntheses of the solid-state forms are presented, and a mathematical model to describe a three-polymorph transformation is discussed in detail. It is shown that, for certain initial solute concentrations, the α polymorph nucleates first and then transforms through the β form to the γ form. Moreover, a supersaturation threshold to nucleate the α form has been observed, and below this threshold value, the γ form nucleates. A theoretical analysis demonstrates that this behavior can be predicted and that this experimental observation is physically sound.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9019616

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5846–5853

Titre :	Regular solution theory for low pressure carbon dioxide solubility in room temperature ionic liquids : ionic liquid solubility parameter from activation energy of viscosity
Type de document :	texte imprimé
Auteurs :	Surya S. Moganty, Auteur ; Ruth E. Baltus, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5846–5853
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Carbon dioxide solubility Ionic liquids Transient thin liquid film technique
Résumé :	The low pressure solubility of carbon dioxide in eight commercially available room temperature ionic liquids was measured at 10, 25, and 40 °C using a transient thin liquid film technique. In this paper, carbon dioxide solubility is reported as the Henry’s law constant for each system. Experimental results were interpreted using regular solution theory where Eyring’s reaction rate theory was successfully applied to estimate the solubility parameter of each ionic liquid from its activation energy of viscosity. Consistent with the regular solution theory, the carbon dioxide solubility was found to be inversely proportional to the solubility parameter of the ionic liquid, and Henry’s law constants were successfully correlated with the square of the difference between ionic liquid and carbon dioxide solubility parameters.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901837k

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5834–5845

Titre :	Effect of feed spacer mesh length ratio on unsteady hydrodynamics in 2D spiral wound membrane (SWM) channel
Type de document :	texte imprimé
Auteurs :	K. K. Lau, Auteur ; M. Z. Abu Bakar, Auteur ; A. L. Ahmad, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5834–5845
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Ladder-type spacer mesh length ratio Spiral wound membranes Computational fluid dynamics approach
Résumé :	The present work involves the simulation and optimization of the ladder-type spacer mesh length (ML) ratio in spiral wound membranes (SWMs), using a two-dimensional (2D) integrated computational fluid dynamics (CFD) approach. The permeation properties, incorporated with a transient unsteady hydrodynamics modeling approach, were used to analyze and optimize the ML value for SWM feed spacers. The influence of unsteady hydrodynamics on the development of the concentration polarization in the membrane channel was also investigated. The optimum ML ratio was determined to be 3, because of its ability to generate a high intensity of unsteady hydrodynamics with the lowest effective concentration polarization factor and the results were further validated using velocity vector plots, wall shear stress analysis, and the localized concentration polarization factor.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9017989

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5826–5833

Titre :	Potential desorbents for propane/propylene separation by gas phase simulated moving bed : a molecular simulation study
Type de document :	texte imprimé
Auteurs :	Miguel A. Granato, Auteur ; Thijs J.H. Vlugt, Auteur ; Alirio E. Rodrigues, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5826–5833
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Separation propane/propylene Simulated moving bed process Equilibrium adsorption isotherms n-butane Neopentane on zeolite 13X Binary mixtures
Résumé :	This paper is focused on using molecular simulation as a tool to guide the choice of desorbent for the separation propane/propylene by simulated moving bed (SMB) processes. Equilibrium adsorption isotherms of n-butane and neopentane on zeolite 13X and adsorption equilibria of binary mixtures of each one of these adsorbates with propane and with propylene were obtained by molecular simulation, in a predictive screening of an adequate desorbent for the separation of propane/propylene by the SMB technology. Comparisons of experimental isotherms with grand canonical Monte Carlo simulations in zeolite 13X showed that the results of n-butane are in excellent agreement with reported simulations and experimental data. The carbon−cation interactions for the quaternary carbon atom of neopentane were established and validated through determination of adsorption properties of binary mixtures of neopentane with propane and with propylene. The lack of experimental data of neopentane adsorption motivated the present study, providing the opportunity to predict the single adsorption isotherms over a temperature range from 273 to 423 K and pressures up to 150 kPa. From the simulated isotherms of neopentane in 13X zeolite, the isosteric heat of adsorption of 39.19 kJ/mol was calculated by using the Clausius−Clapeyron equation, in close agreement with the published value of 41.7 kJ/mol. Additionally, the simulation results of the binary mixtures with propane and with propylene showed that neopentane and propane have similar affinities to the adsorbent, which indicates a less favorable desorption effect for neopentane, compared with that of n-butane.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901732s

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5816–5825

Titre :	Sorption of CO, CH4, and N2 in alkali metal ion exchanged zeolite-X : grand canonical Monte Carlo simulation and volumetric measurements
Type de document :	texte imprimé
Auteurs :	Renjith S. Pillai, Auteur ; Govind Sethia, Auteur ; Raksh V. Jasra, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5816–5825
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	CO sorption CH4 sorptionN2Alkali metal ions Monte Carlo simulation
Résumé :	Sorption of CO, CH4, and N2 in zeolite-X exchanged with different alkali metal ions was studied by volumetric measurements and Grand Canonical Monte Carlo simulation. CO and CH4 sorption is observed to show higher sorption capacity than N2 in all cation exchanged zeolite samples. The adsorption capacity of CO in alkali metal exchanged zeolites is observed to decrease on moving from LiX to CsX, whereas for the methane adsorption capacity varies in reverse order. The isosteric heat of sorption data show stronger interactions of CO and N2 molecules with alkali metal ion exchanged zeolites. The isosteric heat of CH4 show nearly same value (21−24 kJ/mol) for all alkali metal ion exchanged zeolites. Simulation of the CO and N2 sorption in alkali metal zeolite -X clearly shows that the adsorbed CO and N2 molecules are located in proximity to the extra-framework cations in the super cage. Simulated data of adsorption isotherms and heats of adsorption of CO, N2, and CH4 in alkali metal ion exchanged zeolite-X agree reasonably well with the experimental results.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901713m

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5808–5815

Titre :	Stability and performance study of water-in-oil-in-water emulsion : extraction of aromatic amines
Type de document :	texte imprimé
Auteurs :	Jaydeep M. Barad, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5808–5815
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Emulsion liquid membranes Internal acid phase Surfactant concentration Stirrer speed
Résumé :	One of the major obstacles to the application of emulsion liquid membranes to industrial separations is the stability of emulsion globules. Stability of emulsion is affected by two phenomena—globule rupture and osmotic swell. Interfacial shear between the continuous and membrane phase causes the liquid membrane to thin and, in some cases, rupture, thereby affecting separation. Destabilization phenomena affecting the homogeneity of dispersions are emulsion globule migration (creaming, sedimentation) and size variation or aggregation (coalescence, flocculation). In the present study, the stability of an emulsion liquid membrane is studied by varying different parameters, for example, internal acid phase and surfactant concentration and stirrer speed for emulsification. Dispersion destabilization of the emulsion is detected by Turbiscan. Properties such as interfacial tension, drop size distribution, photomicrographs, and zeta potential are also analyzed to evaluate emulsion stability. A stable emulsion is used for the removal of aromatic amines from aqueous solutions. An advancing reaction front model considering competitive transport of aromatic amines has been proposed to simulate data. The simulated curves are found to be in good agreement with the experimental data.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901698u

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5800–5807

Titre :	Measurements of liquid−liquid equilibria for a methanol + glycerol + methyl oleate system and prediction using group contribution statistical associating fluid theory
Type de document :	texte imprimé
Auteurs :	A. Barreau, Auteur ; I. Brunella, Auteur ; Jean-Charles de Hemptinne, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5800–5807
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Ternary system Vapor−liquid−liquid dataFatty acid methyl ester Glycerol Methanol ternary system
Résumé :	A good understanding and prediction of the phase equilibrium of the fatty acid methyl ester (FAME) + glycerol + methanol ternary system is needed to design and optimize the separation unit of the biodiesel production process. In this work, new experimental vapor−liquid−liquid data on the ternary system have been measured at temperatures between 333.15 and 473.15 K. In addition, new data have been gathered on the methanol + glycerol [vapor−liquid equilibrium (VLE)] and methanol + methyl oleate (VLE and liquid−liquid equilibrium) binary systems. A group contribution method combined with a statistical associating fluid theory equation of state (GC-PPC-SAFT) proposed earlier by our group (Tamouza, S., Passarello, J.-P., Tobaly, P., and de Hemptinne, J.-C.Group contribution method with SAFT EOS applied to vapor liquid equilibria of various hydrocarbons series. Fluid Phase Equilib. 2004, 222−223, 67−76) and recently extended to predict VLE of heavy esters and their mixtures (Nguyen Huynh, D., Falaix, A., Passarello, J.-P., Tobaly, P., and de Hemptinne, J.-C.Predicting VLE of heavy esters and their mixtures using GC-SAFT. Fluid Phase Equilib. 2008, 264, 184−200) is here applied to model vapor liquid−liquid equilibria of methanol + glycerol + methyl oleate. The SAFT parameters for the glycerol pure component have been regressed using two association schemes (4C and 3X2B). The dispersive binary interaction parameters kij have been regressed on the binary systems. The group contribution scheme was used for predicting the ester properties.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901379x

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5786–5799

Titre :	Multiobjective optimization for design and operation of the chilling train system in ethylene plants
Type de document :	texte imprimé
Auteurs :	Zhang, Jian, Auteur ; Yanqin Wen, Auteur ; Qiang Xu, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5786–5799
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Chilling train system Mixed-integer nonlinear programming
Résumé :	The chilling train is a very important section for ethylene plants, as its design and operation significantly influence energy consumption and product loss rates. In this paper, a systematic methodology for the optimal design and operation of a chilling train system has been presented. A multiobjective mixed-integer nonlinear programming (MINLP) model has been developed, which aims at minimizing the ethylene loss rate and the exergy-accounted energy consumption, meanwhile maximizing the hydrogen recovery rate. Also presented are the technologies for obtaining reliable thermodynamic properties based on rigorous simulation and the methods for removing redundant variables for MINLP model simplification. On the basis of the methodology, the optimal design and operating conditions of a chilling train system can be simultaneously achieved. A real case study has demonstrated the efficacy of the developed methodology. The results show that the optimized chilling train system has better economic performance than the current system.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100455g

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5775–5785

Titre :	Optimization of a fed-batch simultaneous saccharification and cofermentation process from lignocellulose to ethanol
Type de document :	texte imprimé
Auteurs :	Ming-Liang Chen, Auteur ; Feng-Sheng Wang, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5775–5785
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	imultaneous saccharification Fed-batch process Ethanol
Résumé :	This paper presents the design of optimal control policies for a fed-batch process of simultaneous saccharification and cofermentation to produce ethanol from lignocellulose using enzymes and a recombinant yeast. The goal of the optimal design herein is to find the optimal feed rate, temperature, feed lignocellulosic concentration, and fermentation time that maximizes the ethanol production rate under the constraints of operational restrictions. We applied an Arrhenius relationship to each rate constant to express the temperature effect on the kinetic model for both saccharification and fermentation. Good bioreactor performance not only is defined as the maximum production rate yielded but also considers follow-up separation specifications as the constraints for the optimization problem. Additional restrictions were also considered in the optimization problem to cope with operating costs and environmental impact. Both crisp and fuzzy optimization methods are applied to solve the problem. The fuzzy optimization approach more flexibly obtains a compromised design compared with the crisp optimization method.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie1001982

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5765–5774

Titre :	Cyclic scheduling for ethylene cracking furnace system with consideration of secondary ethane cracking
Type de document :	texte imprimé
Auteurs :	Chuanyu Zhao, Auteur ; Chaowei Liu, Auteur ; Qiang Xu, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5765–5774
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Cracking furnace systems Mixed-integer nonlinear programming Scheduling model
Résumé :	Cracking furnaces of ethylene plants are capable of processing multiple feeds to produce smaller hydrocarbon molecules, such as ethylene, propylene, and ethane. The best practice for handling the produced ethane is to recycle it as an internal feed and conduct the secondary cracking in a specific furnace. As cracking furnaces have to be periodically shut down for decoking, when multiple furnaces processing different feeds under various product values and manufacturing costs are considered, the operational scheduling for the entire furnace system should be optimized to achieve the best economic performance. In this paper, a new MINLP (mixed-integer nonlinear programming) model has been developed to optimize the operation of cracking furnace systems with the consideration of secondary ethane cracking. This model is more practical than the previous study and can simultaneously identify the allocation of feeds with their quantity, time, and sequence information for each cracking furnace. A case study has demonstrated the efficacy of the developed scheduling model.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie1001235

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5752–5764

Titre :	Modeling the coke formation in the convection section tubes of a steam cracker
Type de document :	texte imprimé
Auteurs :	Sandra C. K. De Schepper, Auteur ; Geraldine J. Heynderickx, Auteur ; Guy B. Marin, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5752–5764
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Steam cracker Liquid hydrocarbon droplets CFD code
Résumé :	The presence of liquid hydrocarbon droplets in the convection section of a steam cracker may cause serious fouling problems due to coke formation, especially in high temperature zones. In order to investigate these fouling problems, a model has been developed and implemented in a CFD code to accurately simulate the behavior of a hydrocarbon droplet impinging on a hot surface. The impact energy of the droplet and the hot surface temperature are found to determine the impact behavior. On the basis of the newly developed model, the positions where droplets preferentially collide with the convection section tube walls and liquid material is deposited are determined. Furthermore, a kinetic model describing coke formation out of liquid hydrocarbon droplets in the temperature range of 450−700 K has been developed to calculate the rate of coke formation in each zone of the convection section tube. The calculated coke layer thickness on the most vulnerable tube locations and the industrially available values correspond remarkably well.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100091e

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5742–5751

Titre :	Holistic approach for design of minimum water networks using the mixed integer linear programming (MILP) technique
Type de document :	texte imprimé
Auteurs :	Zainatul B. Handani, Auteur ; Sharifah R. Wan Alwi, Auteur ; Haslenda Hashim, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5742–5751
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Mixed integer linear programming Fresh water Wastewater
Résumé :	Minimum fresh water consumption and wastewater generation in a facility can be achieved when all options for water minimization including source elimination, reduction, reuse/recycle, outsourcing, and regeneration have been considered. This work presents the development of a new generic mixed integer linear programming (MILP) model to holistically minimize fresh water consumption and wastewater generation for systems involving multiple contaminants where the various options for water minimization are simultaneously considered in order to ultimately generate a minimum water utilization network. The MILP model proposed in this work can be used to simultaneously generate the minimum water targets and design the minimum water network for global water-using operations for buildings and industry. This work also includes cases where fresh water concentrations for all contaminants are assumed to be either zero or non-zero. The approach has been successfully implemented in case studies involving an urban building (Sultan Ismail Mosque, UTM) and a manufacturing plant (a chlor-alkali plant).
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie1000357

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5734–5741

Titre :	Emission source characterization for proactive flare minimization during ethylene plant start-ups
Type de document :	texte imprimé
Auteurs :	Chaowei Liu, Auteur ; Qiang Xu, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5734–5741
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Ethylene plant start-ups Plant-wide dynamic simulations
Résumé :	Ethylene plant start-ups generate huge amounts of off-spec products for flaring, which cause negative environmental and societal impacts, as well as tremendous raw material and energy losses that could be unitized to generate much more needed products. Thus, cost-effective start-up flare minimization strategies through proactive process design and operation are becoming more important and attractive to the industry. However, fundamental and quantitative studies on start-up flaring emissions are still lacking, such as (i) what kinds of emission species are contained in the flaring sources; (ii) how much of each emission source will be generated during one start-up; and (iii) what is the dynamic emission profile of each emission source with respect to the start-up time? In this paper, rigorous plant-wide dynamic simulations are employed to characterize flaring emission sources under different flare minimization strategies for an ethylene plant start-up. Deep insights of the emission source distribution and simulated dynamic emission profiles are provided. The study enriches the emission inventory with details for industry point sources, which have never been compiled previously. It also provides detailed technical support for both the industry and environmental agencies on evaluating and developing cost-effective flare minimization strategies in the future.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie902002c

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5725–5733

Titre :	Feasible input manipulation for a nonisothermal direct methanol fuel cell system
Type de document :	texte imprimé
Auteurs :	W. Wu, Auteur ; Y.-T. Lin, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5725–5733
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Direct methanol fuel cell Methanol crossover Water crossover
Résumé :	Through a semiexperimental dynamic modeling of a direct methanol fuel cell (DMFC) system, transient behaviors on describing cell temperature, methanol crossover, water crossover, and electric power are presented. By different operating manners, the new input determinations are addressed. To investigate the performance of DMFC systems, the presented fuel and exergetic efficiencies for the specific probe of energy utilization are evaluated. Through both steady-state and unsteady state analyses, the manipulation of cathode pressure and anode inlet flow temperature is a feasible approach for temperature regulation, but methanol crossover is restricted.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901829a

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5714–5724

Titre :	Sulfur recovery units : adaptive simulation and model validation on an industrial plant
Type de document :	texte imprimé
Auteurs :	Stefano Signor, Auteur ; Flavio Manenti, Auteur ; Maria Grazia Grottoli, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5714–5724
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Sulfur recovery units Adaptive simulation parameters Italy
Résumé :	The paper is aimed at discussing and fixing issues in providing a generalized approach to the simulation of sulfur recovery units (SRUs). The main goal is to get a simulation that is at the same time (i) reasonably detailed and robust to properly characterize SRUs and (ii) so generalized to provide a tool that is not only specific for the case in study. To achieve point (i), standard libraries belonging to commercial process simulators are coupled to specific heuristic relations coming from the industrial experience for modeling the thermal furnace and the catalytic Claus converters; this allows us to infer with a certain reliability those measures that are often missing or unavailable online in these processes. To achieve point (ii), a series of adaptive parameters are filled in the process simulation by making it more flexible and yet preserving all model details. The most recent techniques and numerical methods, to tune the adaptive simulation parameters, are implemented in Visual C++ and interfaced to PRO/II (by SimSci-Esscor) to obtain a robust parameter estimation solved by means of the BzzMath library. At last, the detailed and tuned adaptive simulation is validated along a period of 2 months on a large-scale SRU (TECHNIP-KTI SpA technology) operating in Italy.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901749t

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5702–5713

Titre :	Handling uncertainty in model-based optimal experimental design
Type de document :	texte imprimé
Auteurs :	Tilman Barz, Auteur ; Harvey Arellano-Garcia, Auteur ; Günter Wozny, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5702–5713
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Uncertainties Protein ion-exchange equilibrium parameters
Résumé :	In contrast to the majority of published works in the field of model-based optimal experimental design which focused on numerical studies so as to demonstrate the validity of the OED approach or the development of new criteria or numerical approaches, this work is mainly concerned with the experimental application and practical insights gained from the adaption of an optimal design framework. The presented work is discussed based on the determination of protein ion-exchange equilibrium parameters. For this purpose, special attention is paid to the explicit modeling of all laboratory steps so as to prepare, implement, and analyze experiments in order to have a realistic definition of the numeric design problem and to formally include experimental restrictions and sources of uncertainties in the problem formulation. Moreover, whereas the effect of erroneous assumptions in the initially assumed parameter values have been covered by various authors, in this work, uncertainties are considered in a more general way including those which arise during an imprecise implementation of optimal planned experiments. To compensate for uncertainty influences, a feed-back based approach to optimal design is adopted based on the combination of the parallel and sequential design approaches. Uncertainty identification is done by solution of an augmented parameter estimation problem, where deviations in the experimental design are detected and estimated together with the parameter values. It has been shown that uncertainty influences vanish along with the iterative refinement of the experiment design variables and estimated parameter values.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901611b

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5694–5701

Titre :	Optimization of a chemical vapor deposition process using sequential experimental design
Type de document :	texte imprimé
Auteurs :	Paul J. Wissmann, Auteur ; Martha A. Grover, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5694–5701
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Chemical vapor deposition Sequential experimental design
Résumé :	The exact mechanisms occurring during chemical vapor deposition are often not well understood or quantified, and CVD is therefore difficult to optimize efficiently. In this article, we implement a process optimization method based on sequential experimental design. This method simultaneously employs both mechanistic and empirical models, using confidence intervals to predict the region of potential optima. New experiments are constrained to this region, so that model predictions will be improved near the process optimum. After six initial experiments and two sequential experiments, a process temperature of 760 °C is computed, to achieve a desired film roughness of 7 ± 1.65 nm. The experimental data are obtained using a chemical vapor deposition system. The yttrium precursor material is deposited onto a 1 in. silicon wafer in a vacuum chamber. The samples are then analyzed using an atomic force microscope to determine the roughness of the samples. On the basis of these data, we create models that are purely empirical, and also models that are motivated by a more mechanistic understanding of the process. The rationale is that, rather than concentrating our experimental design on creating either empirical or mechanistic models, both types of models should be considered when optimizing a process. Furthermore, by developing both model types simultaneously, mechanistic understanding of the process can also be improved. Models are developed which predict the thin film roughness from the surface temperature and molar flow rate of the precursor. Five empirical models are considered, as well as two additional models which relate nucleation density to final film roughness using mechanistic modeling. The temperature is found to be most important for controlling the thin film roughness. An empirical model with two fitted parameters and a linear temperature dependence predicted performance best, while a hybrid model using nucleation density and two fitted parameters was second best. The confidence interval for the best model was reduced by 20% using our experimental methodology, using only two sequential experiments. The experiments indicate that the hybrid model does capture some of the trends of the experimental data but needs a stronger dependence on temperature to have more statistical significance.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901055e

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5683–5693

Titre :	Operation condition optimization of p-Xylene oxidation reaction process based on a fuzzy adaptive immune algorithm
Type de document :	texte imprimé
Auteurs :	He Hong, Auteur ; Du Wenli, Auteur ; Qian Feng, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5683–5693
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	p-xylene to terephthalic acid Oxidation Fuzzy adaptive immune algorithm
Résumé :	The oxidation of p-xylene to terephthalic acid (TA) is a significant chemical process of purified TA production. Variation of operation conditions of the reaction directly affects the quality of TA. In this paper a fuzzy adaptive immune algorithm (FAIA) was proposed to realize the operation condition optimization of the p-xylene oxidation reaction. In FAIA, a chaotic hypermutation was developed to strengthen the searching ability of the algorithm, and a new immune network regulatory strategy was devised to maintain population adversity. Furthermore, two fuzzy logic modules were constructed to adjust parameters, further increasing the adaptability of the algorithm. The data of function optimization show that FAIA can quickly converge to the global optimum and overcome premature problems. Optimization results of process variable values of the p-xylene oxidation reaction indicate that the application of FAIA in an oxidation reaction process can greatly save the time of operation condition selection and reduce production cost.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900969c

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5661–5682

Titre :	An operational scheduling model to product distribution through a pipeline network
Type de document :	texte imprimé
Auteurs :	Suelen N. Boschetto, Auteur ; Leandro Magatao, Auteur ; William M. Brondani, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5661–5682
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Pipelines Scheduling
Résumé :	Pipelines have been proved to be an efficient and economic way to transport oil products. However, the determination of the scheduling of operational activities in pipeline networks is a difficult task, and efficient methods to solve such complex problem are required. In this contribution, a real-world pipeline network is studied, and an optimization model is proposed in order to address the network scheduling activities. A hierarchical approach is proposed on the basis of the integration of a mixed integer linear programming (MILP) model and a set of heuristic modules. This article exploits the MILP model, the main goal of which is to determine the exact time instants that products should be pumped into the pipelines and received in the operational areas. These time instants must satisfy the pipeline network management and operational constraints for a predefined planning period. Such operational constraints include pipeline stoppages, movement of batches through many areas/pipelines, use of preferential routes to avoid contamination losses, on-peak demand hours of pumping, local constraints, reversions of flow direction, and surge tank operations, while satisfying a series of production/consumption requirements. The developed continuous-time model is applied to a large real-world pipeline system, where more than 14 oil derivatives and ethanol are transported and distributed between supply and demand nodes.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie900685v

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5654–5660

Titre :	Transient diffusion within spherical particles : numerical resolution of the Maxwell−Stefan formulation
Type de document :	texte imprimé
Auteurs :	Erminia Leonardi, Auteur ; Celestino Angeli, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5654–5660
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Maxwell−Stefan equations Physical systems Mass-transfer
Résumé :	The generalized Maxwell−Stefan equations describe the mass-transfer process in a multicomponent mixture in different physical systems. This approach to the mass-transfer phenomenon has been largely used in particular for the simulation of the multicomponent diffusion in microporous systems. Our group has recently proposed (Leonardi, E.; Angeli, C. J. Phys. Chem. B 2010, 114, 151) a general numerical procedure for the resolution of the Maxwell−Stefan equations in the transient regime for one-dimensional systems. This procedure has been applied for the study of bulk diffusion, the uptake process on a microporous material, and permeation across a microporous membrane. In this paper this approach is extended to the case of diffusion within a sphere, which can be reduced to a one-dimensional problem in the presence of isotropy.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie1004724

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5644–5653

Titre :	Engineering of a wet-end additives program relative to process parameters and to the physical and optical properties of filled paper
Type de document :	texte imprimé
Auteurs :	Gyeong-Yun Kim, Auteur ; Martin A. Hubbe, Auteur ; Chul-Hwan Kim, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5644–5653
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Paper handsheets Wet-end additives
Résumé :	In the manufacture of a paper product, the application of wet-end additives and the adjustments of various conditions can have major effects on the physical and optical properties of the final paper. In this study, we prepared paper handsheets and investigated the effects of many process variables, including the type and amounts of cationic polyacrylamide and colloidal silica, in addition to temperature, duration of mixing, hydrodynamic shear, pH, and variations in electrical conductivity due to salt addition. The most important effects were attributable to variations in the amount, ionic charge, and molecular weight of cationic polyacrylamide, as well as the type and amount of colloidal silica. Many of the observed effects could be explained in terms of fiber flocculation, and the adverse effect of flocculation on the uniformity of the paper, a factor that significantly affected the physical properties. An understanding of the relationships between chemical variables, hydrodynamic shear, and other system variables can be helpful in selecting optimal operating conditions to meet process requirements as well as physical properties of the resulting paper. A statistical analysis was carried out, using normalized coordinates, to show which of the independent variables had significant effects on the response variables.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100434u

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5631–5643

Titre :	Numerical simulation of ethanol−water−NaCl droplet evaporation
Type de document :	texte imprimé
Auteurs :	Xingmao Jiang, Auteur ; Timothy L. Ward, Auteur ; Frank van Swol, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5631–5643
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Droplet evaporation Water Ethanol droplets
Résumé :	A quantitative description of droplet evaporation is important to aerosol research for nanofabrication, spray drying, fuel combustion, pollution control, and respiratory medical treatments. Evaporation is a moving-boundary problem with coupled mass and heat transport. An explicit finite-difference methodology and computer code has been developed for simulation of an evolving droplet, property data for size, and profiles for various compositions and temperature. The code accurately predicts the evaporation of pure water and pure ethanol droplets. To understand aerosol-assisted evaporation-induced self-assembly and the formation mechanism for single-crystal NaCl core/hexagonally ordered mesoporous silica shell particles, evaporation of ethanol−water−NaCl droplets in N2 has been investigated by numerical simulation. The extended universal quasichemical (UNIQUAC) model with a Debye−Hückel term is used to describe the vapor−liquid phase equilibrium. For 1−2-μm-radius droplets with a number density of 107∼108/cm3, it takes only tens of milliseconds to reach phase equilibrium after adiabatic or isothermal evaporation at 25 °C in the drying zone. The droplets entering a heating zone can be simply treated like a single-stage flash evaporation at 25 °C. For a 1-μm-radius droplet, after 0.18 ms of evaporation at 100 °C in N2, the NaCl saturation ratio reaches levels as high as 1.3, first at the droplet center, where the initial NaCl nucleation and crystallization happens as a result of relatively quick evaporation and a steep gradient in the concentration of ethanol, an antisolvent for NaCl. NaCl crystallization “consumes” NaCl molecules near the droplet center and quenches the formation of new stable NaCl nuclei, favoring the formation of only one single-crystal NaCl core per droplet. The code provides guidance for the custom engineering of aerosol nanoparticle architectures.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie902042z

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5625–5630

Titre :	Superhydrophobic surface fabricated from fatty acid-modified precipitated calcium carbonate
Type de document :	texte imprimé
Auteurs :	Zeshan Hu, Auteur ; Yulin Deng, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5625–5630
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Superhydrophobic surface Precipitated calcium carbonate Fatty acid Precipitated calcium carbonate
Résumé :	A very low-cost and simple method for fabricating a superhydrophobic surface with commercially available precipitated calcium carbonate (PCC) and fatty acid is reported in this research article. PCC particles were chemically modified from hydrophilic to hydrophobic in water with fatty acid. The thin film formed by these hydrophobic PCCs shows superhydrophobic and self-cleaning properties. The contact angle hysteresis of modified PCC film was investigated. A sliding angle of 1.75° could be obtained with oleic acid-modified PCC film at an oleic acid concentration of 2.52 wt %. Comparing with oleic acid, the PCC film modified by stearic acid has a higher sliding angle (∼10°).
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901944n

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5616–5624

Titre :	Synthesis of faujasite films on carbon fibers and characterization of their sorption properties
Type de document :	texte imprimé
Auteurs :	Alexandra Jakob, Auteur ; Valentin Valtchev, Auteur ; Michel Soulard, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5616–5624
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Faujasite films Carbon fibers
Résumé :	The ultimate goal of this study is the preparation of materials that prevent organic contamination of satellites in low earth orbit. Carbon fibers were chosen as a substrate because of their light weight and high mechanical resistance, along with a highly accessible surface that could optimize the sorption of the contaminants. Further, the active phase (FAU-type zeolite) was synthesized onto support applying the secondary growth method. The zeolite coatings were crystallized under different conditions in order to control the characteristics of the material. Alkalinity of the initial gel, Si/Al ratio, and synthesis time appear to strongly influence the film characteristics. Thus, highly crystalline FAU-type films with different thicknesses and levels of hydrophilicity were grown. The sorption properties of zeolite films and counterpart powders were investigated by thermogravimetric analyses toward several organic adsorbents (cyclohexane, n-hexane, p-xylene, trimethylbenzene, tetramethoxysilane). The obtained data revealed that the adsorbed quantity of organic species increased with the Si/Al ratio of the zeolite framework due to its increased hydrophobocity. Sorption capacities of the films appeared to be slightly lower than those of their powder counterparts, which was attributed to lower crystal accessibility on zeolite layers. Nevertheless, the set of experimental data demonstrated that the obtained materials are fully conversant with the target application.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901683y

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5610–5615

Titre :	Fabrication and wettability of colloidal layered double hydroxide-containing PVA electrospun nanofibrous mats
Type de document :	texte imprimé
Auteurs :	Lina Zhao, Auteur ; Dayong Yang, Auteur ; Mingdong Dong, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5610–5615
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Colloidal layered double hydroxide/polyvinyl alcohol
Résumé :	We report a facile protocol of preparing colloidal layered double hydroxide/polyvinyl alcohol (cLDH/PVA) electrospun nanofibrous mats via direct incorporation of low-content cLDH nanoplatelets with PVA without aid of any surfactant. The as-prepared cLDH/PVA nanofibrous mats exhibit a uniform, smooth surface and enhanced temperatures of the onset decomposition and inflection compared with those of the electrospun mats of pristine PVA and solid powdery LDH/PVA (pLDH/PVA) with the same LDH content. Subsequent surface chemical modification enables the resulting cLDH/PVA fibrous mats to exhibit superhydrophobicity and adhesion to water droplets, which are distinctly different from the hydrophilicity of the unmodified cLDH/PVA fibrous mats. Our results involving the cLDH/PVA electrospun nanofibrous mats may allow designing a variety of electrospun composite nanofibers with homogeneous morphology and multiple properties.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie902037z

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5603–5609

Titre :	Denitrification of water with activated carbon-supported metallic catalysts
Type de document :	texte imprimé
Auteurs :	Luisa Calvo, Auteur ; Miguel A. Gilarranz, Auteur ; José A. Casas, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5603–5609
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Nitrates Catalytic reduction Trickle bed reactor
Résumé :	The catalytic reduction of nitrates with hydrogen in aqueous phase was studied in a trickle bed reactor using different activated carbon-supported metallic catalysts. Continuous experiments were performed at ambient conditions (25 °C and 1 atm) at different space-time values in the range of 25.8−103.3 kgcat h/mol. The activity of monometallic catalysts based on Pd, Rh, Cu, and Ni was low in all the cases, yielding nitrate conversions below 15%. The introduction of a second metal produced a synergistic effect, improving the catalytic activity and the selectivity toward N2. That increase in activity was more pronounced when using Pd or Rh combined with Cu, reaching nitrate conversions above 80% in the case of Pd−Cu catalysts. The catalyst with a Pd/Cu mass ratio of 2:1 (Pd050Cu025) also showed the lowest selectivity to nitrite and the highest to N2. Metal leaching was always below detection limits for Pd and Rh, whereas in the case of Cu and Ni, significant metal concentrations were found in the reaction effluent, the leaching of Ni being higher. The initial pH significantly affected both activity and selectivity of the bimetallic catalysts, the maximum activity being achieved within the 6−7 range, which also led to the lowest Cu leaching. The use of a two-step reaction system was checked using two different catalysts, a bimetallic Pd−Cu in the first and a monometallic Pd catalyst in the second. With this two-step system, an important reduction of the nitrite originating in the first stage was observed, and the formation of N2 at the expense of ammonium was favored.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100838r

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5588–5602

Titre :	Simulated dynamic optical response strategy for model identification of metal colloid synthesis
Type de document :	texte imprimé
Auteurs :	Roberto Irizarry, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5588–5602
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Metal spherical particle formation Optical kinetic data Metal colloid synthesis
Résumé :	A model for metal spherical particle formation is proposed, guided by optical kinetic data of monodisperse metal colloid synthesis. The dynamic optical response of these systems is characterized by broad bands, making their analysis difficult to interpret in terms of particles sizes. To overcome this problem, the data are analyzed in terms of a new strategy called simulated dynamic optical response. Kinetic data were generated using a silver-ethylenediamine complex reduced with isoascorbic acid as a model system. Using this strategy, it was found that autocatalytic formation of primary particles followed by a zone of very fast aggregation mechanism can describe the dominant dynamics during early stages. In later stages, the dominant mechanism switches to slower aggregation modulated by a stability factor. The presented model and identification strategy may be applied to other reaction precipitation systems to produce metal particles.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100644h

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5583–5587

Titre :	Fenton pretreatment in the catalytic wet oxidation of phenol
Type de document :	texte imprimé
Auteurs :	Aurora Santos, Auteur ; Pedro Yustos, Auteur ; Sergio Rodriguez, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5583–5587
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Catalytic wet oxidation Phenol (PhOH) aqueous solutions Continuous three-phase reactor FR pretreatment
Résumé :	Catalytic wet oxidation (CWO) of 1000 mg/L of phenol (PhOH) aqueous solutions has been carried out using a commercial activated carbon as catalyst, placed in a continuous three-phase reactor at 16 bar, and temperature was changed in the interval 127−160 °C. Pure oxygen was fed as gaseous phase. Pollutant conversion, mineralization, intermediate distribution, and toxicity were measured at the reactor exit. The catalyst weight (W) to liquid flow rate (QL) ratio was varied from 0.3 to 17.5 gACmin/mL. Fenton reagent (FR) has been applied to the same phenolic aqueous samples using different amounts of H2O2 (between 10 and 100% of the stoichiometric dose) and 10 mg/L of Fe2+, in a batch way at 50 °C. An integrated process has been proposed that combines FR as pretreatment of the CWO process. In the FR step, 10% of H2O2, 10 mg/L of Fe2+, and reaction times shorter than 40 min are used. Efluent from FR step is fed to the CWO reactor at 127 °C. High mineralization (80−90%) and total detoxification of the effluent was obtained at the reactor exit using W/QL values lower than 10 g·min/mL. Therefore, the FR pretreatment enhances remarkably the efficiency of the CWO at moderate temperature conditions.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie1004948

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5575–5582

Titre :	Wet oxidation : an option for enhancing biodegradability of leachate derived from municipal solid waste (MSW) landfill
Type de document :	texte imprimé
Auteurs :	Anurag Garg, Auteur ; Alok Mishra, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5575–5582
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Municipal solid waste Landfill leachateCatalytic wet oxidation (WO) process
Résumé :	The present study reports the treatment of municipal solid waste (MSW) derived landfill leachate (initial pH = 7.82 and chemical oxygen demand (COD) = 6400 mg L−1) using catalytic wet oxidation (WO) process. The reaction was performed under moderate conditions (110−150 °C temperature and 0.7 MPa total pressures) in the presence of a CuSO4 catalyst. The effect of the promoter (Na2SO3) was also seen on the COD removal. The results were compared with that obtained for Fe2+ and H2O2 combination. Among all tested combinations, (CuSO4 + Na2SO3 + air) exhibited the best performance with ∼90% COD reduction at 150 °C temperature and 0.7 MPa pressures. Under these conditions, the biodegradability of the treated effluent was improved to 0.66 (from an initial value of 0.38). The average oxidation state of carbon (AOSC) value and Fourier transform infrared (FTIR) spectroscopy confirmed the presence of carboxylic acids in the treated effluent.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100003q

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5569–5574

Titre :	Effect of Mg2+ ions on the nucleation kinetics of calcium sulfate in concentrated calcium chloride solutions
Type de document :	texte imprimé
Auteurs :	Baohong Guan, Auteur ; Liuchun Yang, Auteur ; Zhongbiao Wu, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5569–5574
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Metastable calcium sulfate hemihydrate Nucleation kinetics
Résumé :	The precipitation kinetics of the metastable calcium sulfate hemihydrate (HH) from aqueous solutions has seldom been addressed. For the first time, the nucleation kinetics of calcium sulfate (probably in α-HH form) in concentrated CaCl2 solutions at 90 °C and the effect of Mg2+ ions were investigated by spontaneous precipitation experiments and a turbidity monitoring method. The results indicate that, at a moderate supersaturation with respect to calcium sulfate, Mg2+ ions retard the nucleation with 0.01 M Mg2+ ions showing the strongest effect; at a higher supersaturation, the inhibition effect decreases when the concentration of Mg2+ ions increases from 0.001 to 0.10 M, and 0.20 M Mg2+ ions show a promoting effect on the precipitation. The interfacial tension values increase with the concentration of Mg2+ ions, resulting in a decrease in nucleation rate in Mg2+ ion-containing solutions compared to Mg2+ ion-free solutions. This may indicate an involvement of Mg2+ ions in the surface reaction during calcium sulfate precipitation.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie902022b

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5561–5568

Titre :	Oxidative desulfurization of jet and diesel fuels using hydroperoxide generated in situ by catalytic air oxidation
Type de document :	texte imprimé
Auteurs :	Ramanathan Sundararaman, Auteur ; Xiaoliang Ma, Auteur ; Chunshan Song, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5561–5568
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Oxidative desulfurization Diesel fuels
Résumé :	The objective of this work is to explore the potential of carrying out oxidative desulfurization using air as an oxidant. The liquid fuels to be desulfurized were first contacted with air to produce hydroperoxides in situ, which were then used as selective oxidants to oxidize the sulfur compounds. Unsupported CuO was tested as a catalyst for producing hydroperoxides in the fuel at 120 °C in the presence of air. Air oxidation was also carried out in the presence of Al2O3-supported CuO and also noncatalytically. Unsupported CuO was substantially more active than the other two cases. The yield of the hydroperoxides depends strongly on the catalyst and the reaction temperature; the yield decreased in the order of 120 °C > 140 °C ≫ 100 °C but the rate of oxidation to produce hydroperoxides decreased in the order of 140 °C > 120 °C ≫ 100 °C. It was found that more hydroperoxides could be generated in diesel fuel than in jet fuel, which might be related to the higher concentration of alkyl aromatics in diesel fuel when compared to JP-8 jet fuel. The hydroperoxides generated in situ were then used to oxidize the sulfur compounds in the fuel in the presence of SiO2-supported MoO3 catalyst. Hydroperoxides generated in situ were effective in oxidizing the alkyl-substituted benzothiophene and dibenzothiophene present in jet and diesel fuels to their corresponding sulfones which were then removed by adsorption on beta zeolite. On the other hand, the amount of cumene hydroperoxide required per mole of S for oxidation to sulfone was 1.5 and 10 times higher than the stoichiometric amounts for JP-8 jet fuel and diesel fuel, respectively. This study demonstrates that oxidative desulfurization can be effectively carried out by using air as an oxidant for generating hydroperoxides in situ, which can then be used to selectively oxidize the sulfur compounds to sulfones, thereby eliminating the need for use, storage, and handling of expensive liquid-phase peroxide oxidants.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901812r

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5549–5560

Titre :	Microreactor performance studies of the cycloaddition of isoamylene and a-methylstyrene
Type de document :	texte imprimé
Auteurs :	Obiefuna C. Okafor, Auteur ; Sunitha Tadepalli, Auteur ; Geatesh Tampy, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5549–5560
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Isoamylene α-methylstyrene Cycloaddition reaction
Résumé :	The cycloaddition reaction between isoamylene and α-methylstyrene yields indane compounds 1,1,2,3,3,-pentamethylindane and 3-ethyl-1,1,3-trimethylindane, which are intermediate cyclic products used in the synthesis of musk fragrances. This exothermic reaction is usually carried out industrially in large semibatch reactors. The microreactor, with enhanced heat and mass transfer characteristics, was used for the reaction with aqueous sulfuric acid as catalyst. The dependence of reactant conversion, product yield, and average reaction rates on catalyst concentration, temperature, velocity, residence time, and the molar ratio of the reactants in the feed was investigated. A similar study was also performed in the semibatch reactor to compare its performance with that of the microreactor. Higher product yields were obtained in the microreactor, and the average reaction rates in the microreactor were 3 orders of magnitude greater than those obtained in the semibatch reactor.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901794p

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5543–5548

Titre :	Heat capacity, enthalpy of formation, and entropy of methyl carbamate
Type de document :	texte imprimé
Auteurs :	Zuo-Xiang Zeng, Auteur ; Xiao-Nan Li, Auteur ; Wei-Lan Xue, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5543–5548
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Methyl carbamate Heat capacity
Résumé :	The heat capacity (Cp) of methyl carbamate (MC) was measured with an adiabatic calorimeter. The standard enthalpy of formation (ΔfH0(cr, 298.15 K)) and the standard entropy (S0(cr, 298.15 K)) for MC were determined. Thus, Cp(T) values of MC were obtained for the crystal and liquid forms in the temperature range of 298.15−433.10 K. A quadratic trinomial was used to correlate the data of Cp(T). The enthalpy of fusion of MC was measured using differential scanning calorimetry (DSC), and its sublimation enthalpy was estimated. The gas-phase standard enthalpy of formation (ΔfH0(g, 298.15 K)) of MC was calculated via the method of group contribution developed by Benson. Based on the above data, the values of ΔfH0(cr, 298.15 K) and S0(cr, 298.15 K) of MC were estimated to be −513.57 kJ/mol and 77.1 J mol−1 K−1, respectively. A thermochemical cycle including a reversible reaction was designed to examine the reliability of the estimated values by measuring the equilibrium constant of the reaction. The results showed that the estimated values for MC were acceptable.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie9014342

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5536–5542

Titre :	Catalytic activity in naphthalene reforming of two types of catalytic filters for hot gas cleaning of biomass-derived syngas
Type de document :	texte imprimé
Auteurs :	Manfred Nacken, Auteur ; Lina Ma, Auteur ; Steffen Heidenreich, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5536–5542
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Catalytic filters Naphthalene
Résumé :	The catalytic activity in the reforming of naphthalene of two different types of catalytic filter candles for biomass-derived syngas cleaning are presented and compared at superficial velocities of 72 and 90 m/h, respectively. The tests were performed in a laboratory setup on a fixed catalyst bed and small sections of full size candles. In a 50 h long-term test of the first candle type of fixed bed design, complete naphthalene conversion was found at 800 °C, 100 ppmv H2S, and an average superficial velocity of 135 m/h for the integrated Ni catalyst. Doubling the naphthalene concentration from 5 to 10 g/Nm3 has also led to complete conversion in a short-term test at a superficial velocity of 90 m/h. Because of easier manufacturing of the second candle type, several candles of a catalytic layer design were prepared by using different MgO-containing support materials and adjusting NiO loadings between 35 and 194 wt %. As compared to previous work, a conversion increase from 58 to 74% was achieved at 800 °C, 100 ppmv H2S, and a superficial velocity of 90 m/h that was further improved to 87% by decreasing the superficial velocity to 72 m/h. In the absence of H2S, 96 or 97% conversion was achieved, respectively.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901428b

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5530–5535

Titre :	Determination of the dispersion characteristics of miniaturized coiled reactors with fiber-optic Fourier transform mid-infrared spectroscopy
Type de document :	texte imprimé
Auteurs :	Clemens B. Minnich, Auteur ; Frank Sipeer, Auteur ; Lasse Greiner, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5530–5535
Note générale :	Chemistry engineering
Langues :	Anglais (eng)
Mots-clés :	Miniaturized coiled reactors Fourier transform Tubular reactor
Résumé :	A miniaturized modularized tubular reactor setup designed for flexible small-scale experimentation under continuous flow conditions was investigated for its residence time behavior. Studies focused on the question of whether the coil shape of the tubular reactor segments beneficially affects the dispersion behavior of the system by inducing secondary flows in the dispersed plug flow pattern. In the studies, fiber-coupled sensors for the attenuated total reflectance technique were applied to measure concentration profiles of tracer substances by Fourier transform mid-infrared spectroscopy. Sensor flow cells with specifically structured flow geometries were designed in order to reduce the impact on the flow characteristics, and in this context they have proven to be superior to nonstructured flow cells. Quantitative evaluation of the measured spectra yielded good-quality time profiles of the tracer concentration that were subjected to a mathematical approximation with the well-established dispersion model by Taylor and Aris. In accordance with model predictions from literature, the axial dispersion coefficient is drastically reduced in coiled capillaries as compared to the coefficient in the Taylor−Aris case for straight tubes. Depending on the influence of the tube curvature and the flow properties, expressed by the product of the square Dean number and the Schmidt number, the reduction of the axial dispersion coefficient can be by up to a factor of 4. For chemical processes with critical requirements regarding selectivity, this can be of great advantage since the detrimental impact of axial back-mixing is effectively reduced.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901094q

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5523–5529

Titre :	Ammonium polyphosphate with crystalline form V by ammonium dihydrogen phosphate process
Type de document :	texte imprimé
Auteurs :	Gousheng Liu, Auteur ; Xinchun Liu, Auteur ; Jianguo Yu, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5523–5529
Note générale :	Chemistry engineering
Langues :	Anglais (eng)
Mots-clés :	Ammonium polyphosphate Crystalline form V Condensation water-solubility
Résumé :	Ammonium polyphosphate (APP) with crystalline form V (APP-V) was prepared through the reaction of ammonium dihydrogen phosphate and urea at high temperature and under dry ammonia atmosphere. Effects such as raw material ratios, ammoniation, condensation temperature, and condensation time were examined. Its water-solubility was tested and compared with those of industrial APP-I and APP-II. FTIR, XRD, and TGA techniques were used to characterize this product. The thermal degradation of APP-V was examined and compared with that of APP-I and APP-II; the molecular structure of this APP-V was speculated and discussed.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100453a

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5517–5522

Titre :	An electron-beam irradiation/catalytic oxidation system for purification of aromatic hydrocarbons/air mixture under practical gas-flow condition
Type de document :	texte imprimé
Auteurs :	Teruyuki Hakoda, Auteur ; Akihiko Shimada, Auteur ; Atsushi Kimura, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5517–5522
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Electron-beam (EB) irradiation/catalytic oxidation system Volatile organic compound
Résumé :	An electron-beam (EB) irradiation/catalytic oxidation system was developed for the purification of a volatile organic compound (VOC) gas stream under a practical gas flow condition. This system consists of a compact-sized electron accelerator and an ozone decomposition catalyst, which is MnO2. The removal of toluene and/or xylene and their mineralization were examined with and without catalytic oxidation for a gas stream at a flow rate of 500 Nm3 h−1. A combined catalyst bed enhanced the removal of VOCs and the mineralization of VOC and its irradiation organic byproducts. For example, for an initial concentration of 5 ppmv, the removal ratio of toluene and xylene increased from 60% to 91% and from 81% to 91%, respectively, at a dose of 4.4 kGy. The mineralization ratio increased from 42% to 100% by the catalytic treatment at doses higher than 9.3 kGy. Furthermore, the yield of CO2 to COx increased from 52−60% to 83−89% by the catalytic treatment.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100278k

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5511–5516

Titre :	High oxygen permeation rate in La0.6Sr0.4Ti0.3Fe0.7O3 thin membrane on a porous support with multichannel structure for CH4 partial oxidation
Type de document :	texte imprimé
Auteurs :	Akihiro Kawahara, Auteur ; Yousuke Takahashi, Auteur ; Yuji Hirano, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5511–5516
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Perovskite oxide Multichannel structure Oxygen permeation rate
Résumé :	A preparation of La0.6Sr0.4Ti0.3Fe0.7O3 (LSTF) perovskite oxide on a support with a unique multichannel structure achieved a high oxygen permeation rate. A LSTF thin membrane with 60 μm thickness was successfully prepared on the multichannel support with 30% porosity. The oxygen permeation rate was much improved by using the multichannel structured support, as the permeated oxygen was removed rapidly. On the other hand, partial oxidation of CH4 into CO and H2 is dominant on the LSTF membrane. The oxygen permeation rate increased as the thickness of the membrane and the porous support decreased, and a value of 13.3 cm3/(min cm2) was achieved at 1273 K under a CH4 partial oxidation condition.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901874j

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5504–5510

Titre :	Nitration of phenol over a ZSM-5 zeolite
Type de document :	texte imprimé
Auteurs :	M. Arshadi, Auteur ; M. Ghiaci, Auteur ; A. Gil, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5504–5510
Note générale :	Chemistry engineering
Langues :	Anglais (eng)
Mots-clés :	Liquid phase nitration of phenol Nitric acid
Résumé :	In this paper, liquid phase nitration of phenol over a solid acid catalyst, ZSM-5 zeolite, was investigated by nitric acid (60%) under various solvent and temperature conditions. The performance of the nitration in ortho and para positions of phenol is suggested to derive from the amount of catalyst and the solvent effects. The loading level of the substrate inside or outside the pores of the zeolite makes the relatively high selectivity to the ortho or para product. However, the experimental results are accounted for by the important role of solvent and the amount of ZSM-5 zeolite in ortho/para selectivity.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901862q

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5496–5503

Titre :	Integrated biological and electrochemical oxidation treatment for high toxicity pesticide pollutant
Type de document :	texte imprimé
Auteurs :	Lei Liu, Auteur ; Guohua Zhao, Auteur ; Yaning Pang, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5496–5503
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	integrated biological oxidation Electrochemical oxidation Toxicity pesticide
Résumé :	A novel integrated biological and electrochemical oxidation (BEO) process was proposed for the treatment of biorefractory pesticide wastewater with high toxicity. An acetamiprid solution of 1000 mg L−1 was used as the target pollutant. Its biodegradability in terms of biochemical oxygen demand in a 5-d test period (BOD5)/total organic carbon (TOC) was only 0.0057, presenting its high biorefractory property. In the BEO system with boron-doped diamond electrode (BDD), the value of BOD5/TOC was improved to 1.17 and the toxicity was reduced by 40% in 3 h, maintaining the activity of microorganisms on a biofilter at an appropriate level. The intermediates (mainly small molecule carboxylic acids) produced in the electrochemical process served as nutrients for the microorganisms and then were biodegraded, while the biodegradation of these intermediates further enhanced the electrochemical oxidation of the original pollutant. The synergy of electrochemical and biological processes improved the removal of acetamiprid and TOC with higher efficiency and lower energy consumption. For the same TOC removal, the mineralization current efficiency (MCE) in the BEO was at least 40% higher than that in a single electrochemical oxidation (EO), and the energy consumption was only 53.3 (kW h)/m3 in the BEO in 5 h, which was 44.5% lower than that in the EO. The BEO technique is an efficient method for the treatment of highly concentrated and biorefractory wastewater.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie100333v

[article]
in Industrial & engineering chemistry research > Vol. 49 N° 12 (Juin 2010) . - pp. 5489–5495

Titre :	Coupling between membrane processes and crystallization operations
Type de document :	texte imprimé
Auteurs :	Catherine Charcosset, Auteur ; Roland Kieffer, Auteur ; Denis Mangin, Auteur
Année de publication :	2010
Article en page(s) :	pp. 5489–5495
Note générale :	Chemical engineering
Langues :	Anglais (eng)
Mots-clés :	Couple membrane processes Crystallization operations
Résumé :	The ability to couple membrane processes and crystallization operations, in order to develop efficient crystallization technologies, is increasingly reported. The main features of membrane crystallization systems are (1) to control and limit the maximum level of supersaturation due to defined mass transfer across the membrane; (2) to act as a support able to activate heterogeneous nucleation; (3) to control solid features such as size, shape, polymorphic form, and purity; and (4) to reduce energy consumption. To achieve these goals, several membrane techniques are used: reverse osmosis, membrane distillation, membrane contactor, and membrane templates. This review describes briefly the principles, applications, and advantages and drawbacks of each technique for crystallization operations.
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie901824x

Industrial & engineering chemistry research / Paul, Donald R. . Vol. 49 N° 12

Exemplaires

Bibliothèque Ecole Nationale Polytechnique d'Alger

Accueil

Sélection de la langue

Se connecter

Météo

Adresse

Horaires d'ouverture :