Catalogue en ligne Bibliothèque Ecole Nationale Polytechnique d'Alger

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11809-11817

Titre :	Comparison of the a priori COSMO - RS models and group contribution methods : Original UNIFAC, modified UNIFAC(Do), and modified UNIFAC(Do) Co/nsortium
Type de document :	texte imprimé
Auteurs :	Zhimin Xue, Auteur ; Tiancheng Mu, Auteur ; Jürgen Gmehling, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11809-11817
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Group contribution method Modeling
Résumé :	A comparison of the performances of the COSMO-SAC, COSMO-RS(Ol), original UNIFAC, modified UNIFAC(Do), and modified UNIFAC(Do) Consortium for activity coefficients at infinite dilution and binary VLE data is presented. The σ-profiles used in performing COSMO-SAC and COSMO-RS(Ol) calculations were taken from the published σ-profile database VT 2005. The predicted results were compared with the experimental data stored in the Dortmund Data Bank and analyzed with respect to the types of components in the mixture. The results show that the UNIFAC models based on experimental data are superior to the a priori COSMO-RS models.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26350348

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11803-11808

Titre :	Use of supercritical CO2 and N2 as dissolved gases for the atomization of ethanol and water
Type de document :	texte imprimé
Auteurs :	Giuseppe Caputo, Auteur ; Sara Liparoti, Auteur ; Renata Adami, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11803-11808
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Supercritical state Carbon dioxide
Résumé :	Supercritical dissolved gas atomization (SDGA) is an atomization process in which a gas at temperatures and pressures above the critical point is used as the atomizing medium. The concept of SDGA has been applied mainly using CO2 as atomizing gas in various processes developed for the production of fine particles of pharmaceuticals, polymers, and chemical products and for the atomization of fuels. In this work, SDGA, using ethanol and water as the liquids to be atomized, has been experimentally studied. The spray characteristics, in terms of droplet size and distribution, have been investigated using a laser diffraction analyzer. Ethanol has been chosen due to the large miscibility with CO2 and for its wide use as a solvent in particle formation processes. The use of N2 as an atomizing gas has been also studied. Very narrow droplet size distributions were produced down to 2.5 μm. The properties of the liquid to be atomized (water or ethanol) showed a negligible effect on droplet size. The main parameter that influences droplet size is the gas to liquid mass ratio. Nitrogen has a better potentiality as an atomizing gas with respect to carbon dioxide.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26350347

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11791-11802

Titre :	Unveiling the mechanism of in situ crystallization in the spray drying of sugars
Type de document :	texte imprimé
Auteurs :	M. W. Woo, Auteur ; N. Fu, Auteur ; F. T. Moo, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11791-11802
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Spray drying Crystallization In situ
Résumé :	This work explored the significance of the drying history dependent effect on in situ crystallization in spray drying. Analysis was based on actual single droplet drying kinetics at different drying air temperatures. This paper reports the changes in droplet Tg, T ― Tg, solubility, and supersaturation based on actual experimental data as drying progressed. The glass transition analysis suggests that a critical crystallization period might be significant for in situ crystallization in spray drying. This finding highlights the danger in using the final particle condition, delineated by the dyer outlet conditions, as a measure of partial crystallization in spray dried particles. Extended analysis using the nucleation-growth mechanism pointed to the same crystallization phenomenon analogous to the critical crystallization period concept.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26350346

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11778-11790

Titre :	Performance of an IGCC plant with carbon capture and coal - CO2 - slurry feed : Impact of coal rank, slurry loading, and syngas cooling technology
Type de document :	texte imprimé
Auteurs :	Cristina Botero, Auteur ; Randall P. Field, Auteur ; Robert D. Brasington, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11778-11790
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Cooling Synthesis gas Loading Carbon dioxide Coal
Résumé :	The high heat capacity and latent enthalpy of vaporization of water lead to a low gasification efficiency in gasifiers fed with coal-water slurry. Liquid carbon dioxide, CO2(1), has been suggested as an alternative slurrying medium to improve the efficiency of low-rank coal gasification in integrated gasification combined cycle power plants with carbon capture. Steady-state process simulation is used in this work to confirm published findings and present a comprehensive assessment of the impact of the coal rank, gasifier cooling technology, and CO2 slurry loading uncertainty on the performance advantage of CO2 slurry-fed plants. A power generation efficiency improvement of up to 25% (5%-points) is predicted, which is shown to increase with decreasing coal rank and to be highest for full-quench gasifier cooling technology; the latter is a significant source of capital cost savings and is especially attractive when combined with CO2 slurry feed. Using CO2(1) instead of water slurry reduces the performance penalty of low-rank coal gasification by half, thus substantially improving the feedstock flexibility of the plant. With a single exception, the performance benefit of coal-CO2 slurry was found to be outside the uncertainty range of the slurry loading, which is still one of the key unknowns of this alternative feed system.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26350345

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11764-11777

Titre :	Optimization of reverse osmosis networks with spiral - wound modules
Type de document :	texte imprimé
Auteurs :	Yawei Du, Auteur ; Lixin Xie, Auteur ; Yuxin Wang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11764-11777
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Spiral Membrane separation Reverse osmosis Optimization
Résumé :	An optimization of reverse osmosis (RO) networks for seawater desalination with spiral-wound modules (SWM) was presented in this work. The membrane transport model, which was based on the mass and momentum transport equations, took into consideration the longitudinal variation of the velocity, the pressure, and the salt concentration in the membrane modules. The pressure exchanger (PX) was included in the RO superstructure, and salinity increase caused by volumetric mixing in the PX was considered. The results obtained from the presented model were compared with the actual plant operational data from literature and found to be in good agreement with relative errors of 0.81%∼2.15% and 0.01%∼0.09%, in terms of water recovery and salt rejection, respectively. The optimum design problem was formulated as a mixed integer nonlinear programming (MINLP) problem. The variation of feed salinity was studied using the RO networks model. For the feed concentration higher than 32 kg/m3, one-stage RO system is favored. When the feed concentration is below 28 kg/m3, two-stage RO system is the better choice. The unit product cost increases with the decreases of permeate concentration requirement. For the looser permeate concentration requirement (0.30 kg/m3), one-pass configuration can meet the required quality of desalted water. When the lower permeate quality requirement of concentration is from 0.050―0.20 kg/m3, a two-pass system is more suitable. The influence of system recovery rate on the plant performance was discussed. Finally, sensitivity analysis showed that the total annualized cost is highly sensitive to the feed flow rate, the operating pressure, and electricity cost, while the energy consumption is highly sensitive to the operating pressure, the feed salinity, and the feed temperature.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26350344

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11753–11763

Titre :	Design and control of thermally coupled reactive distillation for the production of isopropyl acetate
Type de document :	texte imprimé
Auteurs :	Hao-Yeh Lee, Auteur ; I-Kuan Lai, Auteur ; Huang, Hsiao-Ping, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11753–11763
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Isopropyl Thermally coupled
Résumé :	Isopropyl acetates are important organic solvents that are widely used in the production of varnishes, ink, synthetic resins, and adhesive agents. Previous studies developed a process for the production of isopropyl acetate incorporating a reactive distillation (RD) column, a decanter, and a stripper. According to the previous study, the rectifying section of the RD column has a prominent remixing phenomenon. Furthermore, the overhead compositions of RD column and the stripper are all within the liquid–liquid equilibrium envelope. Based on the above observations, a thermally coupled design of this process is established. The key points in the thermally coupled design are: to move the location of the decanter to the stripper side, to totally reflux the organic phase outlet stream, and to sidedraw a liquid stream from the stripper to the RD column. Simulation result shows that 23.14% energy savings can be realized using the proposed thermally coupled design. The control strategy of the proposed design flowsheet is also investigated using tray temperature control loops to indirectly control the product composition. The proposed control strategy is capable of maintaining high-purity product, despite changes in feed composition and throughput.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300647h

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11744–11752

Titre :	Assessment of Proportional–Integral Control Loop Performance for Input Load Disturbance Rejection
Type de document :	texte imprimé
Auteurs :	Zhenpeng Yu, Auteur ; Jiandong Wang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11744–11752
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Disturbance rejection Integral proportional control
Résumé :	This paper studies the performance assessment of proportional–integral (PI) control loops in terms of rejecting input load disturbances. The direct synthesis (DS-d) method for disturbance rejection is adopted to design PI controller parameters. The lower bound of the integrated absolute error (IAE) is established, from closed-loop responses subject to step or other general types of input load disturbance changes. A DS-d IAE-based index is formulated by using the lower bound of the IAE as a performance benchmark. A novel seminonparametric method is proposed to estimate the required parameters for calculating the performance index. Simulation and experimental examples are provided to validate the performance benchmark and to demonstrate the effectiveness of the proposed performance index.
REFERENCE :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26350342

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11731–11743

Titre :	Economic plantwide control of a C4 isomerization process
Type de document :	texte imprimé
Auteurs :	Rahul Jagtap, Auteur ; Nitin Kaistha, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11731–11743
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Isomerization process
Résumé :	Plantwide control system design for economically optimal operation over a large throughput range of a C4 isomerization process is considered. The steady-state process degrees of freedom (dofs; eight in total) are optimized for a given throughput (mode I) and maximum throughput (mode II). At maximum throughput, all of the steady-state dofs are exhausted in driving as many constraints (inequality/equality) active. For this process, it is possible to synthesize a simple decentralized plantwide control system (CS1) for tight control of all of the active constraints at maximum throughput with negligible back-off due to transients with satisfactory inventory regulation and process stabilization. A unique feature of CS1 is the location of the throughput manipulator (TPM) inside the plant (in contrast to that at the process feed) and its relocation due to input saturation in a split range arrangement. A comparison with the conventional structure (CS2) with TPM at the process feed and conventional overrides for handling constraints demonstrates the economic and dynamic superiority of CS1.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3001293

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11717-11730

Titre :	Simplified methodology for the design and optimization of thermally coupled reactive distillation systems
Type de document :	texte imprimé
Auteurs :	Fernando Israel Gómez-Castro, Auteur ; Rico-Ramirez, Vicente, Auteur ; Juan Gabriel Segovia-Hernandez, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11717-11730
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Distillation with reaction Optimization Design
Résumé :	New intensified schemes have been recently proposed as an attempt to reduce energy requirements and equipment costs in reaction-separation processes. A design methodology for thermally coupled reactive distillation systems is proposed in this work. To design the columns, a method based on the Fenske―Underwood―Gilliland (FUG) equations is proposed and tested. The FUG equations, the mass and energy balances, and the phase equilibrium equations are used to formulate the model of the intensified systems. Such a model is then solved as a nonlinear programming problem; the objective function is the minimization of the heat duty in the column. Biodiesel production through the esterification of oleic acid with supercritical methanol is used as a case study. Results show the feasibility of obtaining designs with low energy requirements by using the proposed methodology. Because of nonconvexities present in the formulation, the estimated interlinking flows for the reactive Petlyuk column might not correspond to a minimum for energy requirements. Nevertheless, the resulting designs not only show low heat duties, with a difference of less than 2% from that minimum, but also have the capacity of achieving the desired conversion and purities.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26350340

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11710-11716

Titre :	Synthesis of optically active ZnS – carbon nanotube nanocomposites in supercritical carbon dioxide via a single source diethyldithiocarbamate precursor
Type de document :	texte imprimé
Auteurs :	Michael J. Casciato, Auteur ; Galit Levitin, Auteur ; Dennis W. Hess, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11710-11716
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Precursor Supercritical state Carbon dioxide Nanocomposite
Résumé :	Zinc sulfide nanoparticles (ZnS NPs) have been deposited on carbon nanotubes (CNTs) from a single source precursor, zinc(II) bis(diethyldithiocarbamate), using a one-step batch supercritical carbon dioxide (sc-CO2) process. By eliminating the need for an additional sulfur source while simultaneously employing CO2 as the solvent, this method replaces environmentally unfriendly chemicals commonly used in ZnS―CNT nanocomposite synthesis such as ethylene glycol, thiourea, and hydrogen sulfide. ZnS NP morphology displayed large clusters (209 ± 24 nm) that were comprised of smaller particles (16.9 ± 1.9 nm). Photoluminescence spectroscopy demonstrated broad band fluorescence of the ZnS―CNT nanocomposite at 440 nm (2.82 eV) and fluorescence of a Mn doped ZnS-CNT nanocomposite at 445 nm (2.79 eV) and 602 nm (2.07 eV), also in agreement with previous studies. The ZnS―CNT nanocomposite was compared to ZnS NPs synthesized in the absence of a substrate; results indicated that the ZnS―CNT nanocomposite was formed by a heterogeneous reaction mechanism in the sc-CO2 system.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26350339

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11700-11709

Titre :	Copper Ferrite-Graphene Hybrid : A Multifunctional Heteroarchitecture for Photocatalysis and Energy Storage
Type de document :	texte imprimé
Auteurs :	Yongsheng Fu, Auteur ; Qun Chen, Auteur ; Mingyang He, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11700-11709
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Storage Photocatalysis
Résumé :	A straightforward strategy is designed for the fabrication of CuFe2O4-graphene heteroarchitecture via a one-step hydrothermal route to allow multifunctional properties, i.e., magnetic cycling, high photocatalytic activity under visible light irradiation, and excellent electrochemical behaviors for use as the anode in lithium-ion batteries (LIBs). Transmission electron microscopy (TEM) observations indicate that graphene sheets are exfoliated and decorated with hexagonal CuFe2O4 nanoflakes. The photocatalytic activity measurements demonstrate that the combination of CuFe2O4 and graphene results in a dramatic conversion of the inert CuFe2O4 into a highly active catalyst for the degradation of methylene blue (MB) under visible light irradiation. CuFe2O4 nanoparticles themselves have excellent magnetic properties, which makes the CuFe2O4-graphene heteroarchitecture magnetically recyclable in a suspension system. It should be pointed out that the CuFe2O4-graphene (with 25 wt % graphene) heteroarchitecture as anode material for LIBs shows a high specific reversible capacity up to 1165 mAh g-1 with good cycling stability and rate capability. The superior photocatalytic activity and electrochemical performance of the CuFe2O4-graphene nanocomposite can be attributed to its unique heteroarchitechture, which provides the remarkable synergistic effect between the CuFe2O4 nanoflakes and the graphene sheets.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26350338

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11695-11699

Titre :	Orientation structures in injection - molded pellets of polystyrene / carbon nanotube nanocomposites
Type de document :	texte imprimé
Auteurs :	Cuiping Yuan, Auteur ; Guangming Chen, Auteur ; Jiping Yang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11695-11699
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Nanocomposite Pellet
Résumé :	The orientation structures of both carbon nanotubes (CNTs) and polymer molecular chains in the skin―core structure of polystyrene/multiwalled carbon nanotube (PS/MWCNT) nanocomposite melt-injection-molded pellets were examined. Scanning electron microscopic (SEM) and transmission electron microscopic (TEM) images clearly show the MWCNT preferred orientation along the melt shearing direction, while polarized Raman spectroscopy results consolidate the MWCNT preferred orientation in each of the skin, medium, and core layers of the injection-molded pellets. By infrared dichroism measurements, a preferred orientation of the PS side groups (phenyl rings) perpendicular to the melt shearing direction was deduced at all depths of the present injection-molded nanocomposite pellet. Meanwhile, the MWCNTs have little effect on the random orientation of the PS main chain (-CH2- groups) with a dichrolc ratio near unity.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26350337

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11688-11694

Titre :	Heteroflocculation of a cationic oil - in - water emulsion resulting from fontainebleau’s sandstone powder addition as a model for asphalt emulsion breakup
Type de document :	texte imprimé
Auteurs :	Ronald A. Mercado, Auteur ; Veronique Sadtler, Auteur ; Philippe Marchal, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11688-11694
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Modeling Powder Emulsion
Résumé :	The use of asphalt emulsions for road fabrication is rapidly gaining in importance mainly due to energy savings, less environmental impact, and better properties of the final product. However, the formulation of these emulsions still requires a better understanding, particularly concerning their breaking phenomena. When a cationic model emulsion is contacted with a solid having a negative-charged surface, physicochemical driving forces result in the emulsion destabilization. As a consequence, a viscosity reduction of the remaining emulsion is observed, as well as the emulsion breakup through a heteroflocculation mechanism provided the solid surface is large enough. Emulsion systems at equilibrium, containing cetylpyridinium chloride (CPC), paraffin oil, and Fontainebleau's sandstone powder and having different droplet sizes, are studied. The results show that the dispersed oil fraction decreases after each addition of sandstone aliquots, and this depends on the concentration of CPC in the continuous phase of the emulsion. As the droplet size and distribution remain constant during the process, it is assumed that the emulsion heteroflocculation is the result of direct oil droplets adhesion on the sand surface, followed by their coalescence around the sand particles.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26350336

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11681–11687

Titre :	An approach for the prediction of blistering on polymer – steel lining systems exposed to an aqueous environment
Type de document :	texte imprimé
Auteurs :	Chau Van Dinh, Auteur ; M. Kubouchi, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11681–11687
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Polymeric lining system
Résumé :	Blistering is a serious problem for a polymeric lining system because is causes delamination, breakage of the lining layer, etc., leading to a reduction/loss of the corrosion protection. The prediction of blistering is a challenging task and is of great significance in practice. In this paper, a model established for the prediction of blistering on a polymer–steel lining system is presented. The model is based on the concept that a blister occurs if its blistering energy exceeds the adhesion energy of the lined polymer. Several lining systems (polyethylene–steel and fluoropolymer–steel) were selected for evaluation of the model. Experimental data showed that the model can be applied to predict the osmotic blistering when a polymeric lining system works under an aqueous environment.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202975s

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11674–11680

Titre :	Effect of titania addition on the performance of CoMo / Al2O3 Sour water gas shift catalysts under lean steam to gas ratio conditions
Type de document :	texte imprimé
Auteurs :	Bonan Liu, Auteur ; Qiuyun Zong, Auteur ; Peter P. Edwards, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11674–11680
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Titania Catalysts
Résumé :	Effect of Titania Addition on the Performance of CoMo/Al2O3 Sour Water Gas Shift Catalysts under Lean Steam to Gas Ratio Conditions * Abstract * HTMLFull Text HTML * PDFHi-Res PDF[1364 KB] * PDFPDF w/ Links[480 KB] * Figures * Reference QuickView Your current credentials do not allow retrieval of the full text. Purchase the full-text Cart * PDF/HTML, figures/images, references and tables, (where available) PDF Bonan Liu †‡, Qiuyun Zong ‡, Peter P. Edwards †, Fei Zou †, Xian Du †, Zheng Jiang †, Tiancun Xiao †§, and Hamid AlMegren † Inorganic Chemistry Laboratory, Oxford University, South Parks RoadOX1, 3QR, U.K. ‡ Qindao Lianxin Chemical, Qingdao, Shandong Province, P R China § Guangzhou Boxenergy Technology Ltd, Guangzhou, P R China Petrochemical Research Institute, King Abdulaziz City for Science and Technology, P.O. Box 6086, Riyadh 11442 Ind. Eng. Chem. Res., 2012, 51 (36), pp 11674–11680 DOI: 10.1021/ie3009764 Publication Date (Web): August 21, 2012 Copyright © 2012 American Chemical Society *E-mail: xiao.tiancun@chem.ox.ac.uk. CASSection: Fossil Fuels, Derivatives, and Related Products Abstract CoMo/Al2O3 sour water gas shift catalysts with and without TiO2 modification have been tested in parallel industrial reactors under lean steam/gas conditions for two years, and part of catalyst samples was taken out each year during the maintenance period. The catalyst samples have been characterized using temperature programmed sulfurization (TPS), X-ray diffraction (XRD), and laser Raman and BET surface area measurements. The results have shown that adding TiO2 to the catalyst makes the active components, e.g., Mo and Co, easier to be sulfurized with higher sulfur capacity in the catalyst itself. This may be the main reason why the TiO2 modified CoMo catalyst to be active even at low H2S gas stream. The results from industrial operation showed that adding TiO2 to the shift catalyst increases the catalyst activity and stability, presents the higher shift activity in a broader range of H2S content, depresses the aggregating of the molybdenum oxide, and reduces carbon deposition. In addition, the TiO2 additive in the catalyst also helps to maintain the physical properties of the shift catalysts. In the freshly prepared catalyst, the active components e.g., MoO3 is mainly present in the internal surface or sublayer of the catalyst, but it gradually migrates to the catalyst surface with the time on stream. In summary, the CoMo/Al2O3 based sour water gas shift catalyst showed stable shift performance under the lean steam/gas conditions, adding TiO2 to the catalyst significant improves the catalyst activity and resulting into stable operation in the industrial reactor operation in a wide range of H2S concentrations.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3009764

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11667–11673

Titre :	MnOx – CeO2 / activated carbon honeycomb catalyst for selective catalytic reduction of NO with NH3 at low temperatures
Type de document :	texte imprimé
Auteurs :	Yanli Wang, Auteur ; ChuanZhang Ge, Auteur ; Liang Zhan, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11667–11673
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Catalyst
Résumé :	Activated carbon honeycomb supported manganese and cerium oxides (MnOx–CeO2/ACH) catalysts were investigated for selective catalytic reduction (SCR) of NO at low temperatures of 80–200 °C. Compared with ACH supported manganese oxide catalyst (MnOx/ACH), MnOx–CeO2/ACH catalysts show much higher SCR activity and higher selectivity to N2. NO conversion can be improved by the addition of CeO2 from less than 50% to 100% at 80–160 °C. The N2 selectivity of higher than 99.8% is obtained over the Ce(1)Mn/ACH catalyst at 80–200 °C. Results indicate that the addition of CeO2 improves the distribution of MnOx and enhances the oxidation of NO to NO2, producing more absorbed NO3– on the catalyst surface, which is then reduced into N2 by NH3. These behaviors account for the promoting effect of CeO2 on the SCR activity.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300555f

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11659-11666

Titre :	Characterization of solid acid catalysts and their reactivity in the glycolysis of poly(ethylene terephthalate)
Type de document :	texte imprimé
Auteurs :	Minli Zhu, Auteur ; Zengxi Li, Auteur ; Qian Wang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11659-11666
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Chemical reactivity Acid catalysis
Résumé :	Glycolysis of poly(ethylene terephthalate) with ethylene glycol was carried out with the catalysts of sulfated cobalt oxide (SO42―/Co3O4) and zinc-modified sulfated cobalt oxide (SO42―/Co―Zn―O). The catalysts prepared at different calcination temperatures have been characterized by various techniques. These techniques include X-ray diffraction, Raman spectrum, gas adsorption analysis, NH3-temperature programmed desorption, and IR spectroscopy of pyridine adsorption. The performances of these catalysts on the depolymerization of PET under mild conditions were studied, and relationships between the catalysts' textural properties, the surface acidity, and the catalytic activity have been investigated. The experimental results showed that the catalytic activity on glycolysis of PET was significantly improved by the catalysts of binary sulfur oxides of SO42―/Co―Zn―O. The conversion of PET obtained on SO42―/Co―Zn―O-300 °C was 96%, and the selectivity of BHET was 75%, after 3 h at 180 °C under atmospheric pressure.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26350332

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11653-11658

Titre :	Kinetics study for ion - exchange - resin catalyzed hydrolysis of methyl glycolate
Type de document :	texte imprimé
Auteurs :	Yan Xu, Auteur ; Wenjing Dou, Auteur ; Yujun Zhao, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11653-11658
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Hydrolysis Catalytic reaction Ion exchange resin Kinetics
Résumé :	The hydrolysis of methyl glycolate catalyzed by commercial cation-exchange resin was studied in a stirred tank batch reactor. It was found that 001×7 resin was an effective catalyst for the hydrolysis of methyl glycolate. The effects of catalyst loading, initial reactant ratio and temperature have been examined in detail. The kinetics of glycolate hydrolysis was evaluated by the use of the pseudohomogeneous model, which was found to represent the kinetics fairly well, due to the total dissociation of the active sulfonic acid group in swollen polymer resin in the presence of water. The kinetics was expressed in terms of activities and the activity coefficients were estimated by using the group contribution method UNIFAC. The activation energy was found to be 59.26 kJ/mol for 001x7 resin, indicating surface reaction is the rate-controlling step.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26350331

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11643-11652

Titre :	Micromixing Efficiency of a Spinning Disk Reactor
Type de document :	texte imprimé
Auteurs :	Nikolas C. Jacobsen, Auteur ; Olaf Hinrichsen, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11643-11652
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Reactor Micromixing
Résumé :	This work presents the experimental investigation of the micromixing characteristics of a spinning disk reactor (SDR) by using a system of competitive parallel reactions, particularly the iodide―iodate reaction (Villermaux―Dushman reaction). The objective of this study is to analyze the influence of various operating parameters such as the rotational speed of the disk, the feed location, and the surface structure of the disk on the mixing quality. It is shown that the micromixing efficiency can be particularly controlled by variation of the disk speed. These results are further validated by the investigation of the precipitation reaction of barium sulfate. This synthesis offers fast reaction kinetics with induction times in the range of milliseconds, resulting in a mixing time which lies in the range of this for efficient mixers like microreactors. The use of the spinning disk technology enables one to produce particles continuously with controllable mean sizes down to 27 nm, without the risk of fouling or blocking.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26350330

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11636-11642

Titre :	Mass transfer at a vertical oscillating screen stack in relation to catalytic and electrochemical reactor design
Type de document :	texte imprimé
Auteurs :	M. H. Abdel-Aziz, Auteur ; I. Nirdosh, Auteur ; G. H. Sedahmed, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11636-11642
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Design Electrochemical reactor Catalytic reaction Mass transfer
Résumé :	The aim of the present work is to improve the performance of the parallel plate catalytic and electrochemical reactor in conducting diffusion controlled reactions by using parallel oscillating vertical arrays of closely packed screens. To this end, rates of mass transfer at oscillating vertical single screen and arrays of closely packed screens were studied by measuring the limiting current of the cathodic deposition of copper from acidified copper sulfate. Variables studied were amplitude and frequency of vibration, screen mesh number, and number of screens per stack. The mass transfer data at a single vibrating screen were correlated by the equation: Sh = 0.73Sc0.33Re0.38v. Increasing mesh number of the screen was found to increase the mass transfer coefficient, while increasing the number of screens per stack decreased the mass transfer coefficient below single screen value. The enhancement ratio between oscillating screen array and oscillating vertical plate (the volumetric mass transfer coefficient ratio) ranged from 11.7 to 27.87 depending on the operating conditions. Electrical energy consumption of the present reactor was found to be lower than the value reported in the literature for electrowinning of copper using traditional parallel plate reactor. In view of this, the possibility of using oscillating vertical screen stack in building high space-time yield modular parallel plate electrochemical reactor suitable for wastewater treatment, electroorganic synthesis, and electrochemical energy storage via redox cells was noted. Also, the possibility of using the present geometry in building catalytic reactors suitable for conducting diffusion controlled liquid―solid reaction was highlighted.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26350329

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11629-11635

Titre :	Agglomeration detection in horizontal stirred bed reactor based on autoregression model by acoustic emission signals
Type de document :	texte imprimé
Auteurs :	Yefeng Zhou, Auteur ; Zhengliang Huang, Auteur ; Ren Congjing, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11629-11635
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Acoustic emission Modeling Stirred tank reactor Agglomeration
Résumé :	Agglomeration occurring in horizontal stirred bed reactors (HSBR) for polyolefin production has negative impacts on the efficiency of the reactor operation and may sometimes lead to unscheduled shutdown of the plant. In this paper, an autoregression (AR) model based on acoustic emission (AE) technique has been proposed to establish the qualitative relationship between AE signals and agglomeration in the HSBR. In this method, the frequency of AE signal varies with particles of different sizes striking the reactor walls. From the cold model experiments, it was found that AR power spectrum became fluctuant after the addition of agglomerations into laboratorial scale HSBR, and meanwhile the low frequency band energy ratio and the variance of AE signals kept rising. Furthermore, this AE-based AR model was also successfully applied to detect the agglomeration in an industrial HSBR unit, showing that the method could monitor agglomerations in an environmentally friendly manner and with fairly good accuracy.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26350328

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11618-11628

Titre :	Irregularities in product distribution of fischer – tropsch synthesis due to experimental artifact
Type de document :	texte imprimé
Auteurs :	Junhu Gao, Auteur ; Baoshan Wu, Auteur ; Liping Zhou, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11618-11628
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Fischer Tropsch synthesis
Résumé :	Experimental product distribution of Fischer—Tropsch synthesis frequently presents notable deviations from the typical double-a Anderson―Schulz—Flory pattern: bump or dip around the breaking carbon number, positive or negative deviation for heavy hydrocarbons. These irregularities were studied experimentally in a fixed-bed reactor over an industrial Fe/ Mn catalyst, and theoretically by a product separation model based on Aspen Plus software. First, it was found that the unsteady state of reaction condition or improper gas chromatograph procedure could lead to deviation for heavy hydrocarbon distribution. Second, the bump near the breaking carbon number could be attributed to the accumulation of water in hot trap, which leads to an inaccurate measurement of the wax amount. This irregularity can be eliminated by selecting either a higher temperature or a lower pressure of the hot trap. Third, vaporization or flash loss of the oil sample during product collection could result in dip in light hydrocarbon distribution. High syngas conversion levels should be avoided for accurate data acquirement.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26350327

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11613-11617

Titre :	Identification of the molecular species responsible for the initiation of amorphous dithiazine formation in laboratory studies of 1,3,5 - tris (hydroxyethyl) - hexahydro - s - triazine as a hydrogen sulfide scavenger
Type de document :	texte imprimé
Auteurs :	Grahame N. Taylor, Auteur ; Philippe Prince, Auteur ; Ron Matherly, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11613-11617
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Hydrogen sulfides
Résumé :	Amorphous dithiazine is produced from a solution of tris-(2-hyroxyethyl)-hexahydro-s-triazine (I) that is heavily consumed by hydrogen sulfide (H2S). Previously, it has been reported that the chemical structure of amorphous dithiazine is a polymeric structure which involves opening of the dithiazine ring. Evidence is presented here that the first step in this polymerization reaction is conversion of the terminal hydroxyl functionality into a terminal thiol. Thereafter, the thiol initiates the ring opening of the dithiazine to yield a polymeric, highly insoluble material. It has been observed that the critical chemical species in the initiation of this chain reaction is the bisulfide anion. This bisulfide anion is produced from the reaction of H2S with ethanolamine liberated in the sulfur insertion reaction undergone by tris-(2-hyroxyethyl)-hexahydro-s-triazine (I). This process has been artificially induced by the reaction of monomeric or crystalline 5-hydroxyethyldithiazine (II) and ethanolammonium hydrosulfide.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26350326

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11605-11612

Titre :	Investigation +into a pour point depressant for shengli crude oil
Type de document :	texte imprimé
Auteurs :	Long Fang, Auteur ; Xiaodong Zhang, Auteur ; Jinhai Ma, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11605-11612
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Crude oil
Résumé :	A new-style pour point depressant (PPD) for crude oil was prepared by mixing the aminated copolymer and the composite commercial ethylene―vinyl acetate copolymers (EVA) in fixed proportion. The aminated copolymer was synthesized by amination of terpolymer copolymerized with monomers octadecyl acrylate, maleic anhydride, and vinyl acetate. Moreover, the aminated copolymer was characterized by Fourier transform infrared (FTIR) spectroscopy, 1H nuclear magnetic resonance (1H NMR), and gel permeation chromatography (GPC). The interaction between components of the crude oil and the PPD was investigated by FTIR, differential scanning calorimetry (DSC), and cross-polarized light microscopy. The results showed that the PPD could form asphaltene-PPD-resin agglomerates. The new agglomerates became the efficient nucleator of the crude oil beneficiated with PPD. They changed the process of wax crystallization and greatly depressed the pour point of the crude oil.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26350325

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11598-11604

Titre :	H2SO4 - catalyzed hydrothermal pretreatment of triploid poplar to enhance enzymatic hydrolysis
Type de document :	texte imprimé
Auteurs :	Haiyan Yang, Auteur ; Kun Wang, Auteur ; Feng Xu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11598-11604
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Hydrolysis Pretreatment Catalytic reaction
Résumé :	Sealed structure of plant biomass resists assault on cellulose from enzymatic deconstruction. In this study, pretreatments of triploid poplar were conducted with 0.5 wt % H2SO4 at various temperatures (100―200 °C) to loosen the intricate structure. The effect of temperature on cellulose structure and enzymatic digestibility was evaluated. The results indicated that the effective removal of hemicelluloses and amorphous cellulose incurred the increment of crystalline indices of residues. Companied with the degradation of carbohydrates, inhibitory compounds were accumulated with the increasing severity. On the whole, 120 °C was considered as the optimum temperature by taking the balance between substrate digestibility and recovery into account.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26350324

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 36 (Septembre 2012) . - pp. 11593-11597

Titre :	Bromination of deactivated aromatic compounds with sodium bromide / sodium periodate under mild acidic conditions
Type de document :	texte imprimé
Auteurs :	Lalit Kumar, Auteur ; Tanu Mahajan, Auteur ; D. D. Agarwal, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11593-11597
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Bromination
Résumé :	A new, simple, and practical aromatic bromination process is disclosed wherein NaBr/NaIO4 combination in acidic medium was efficiently utilized for the first time in the bromination of deactivated aromatic compounds, thus, affording the corresponding bromo-derivatives of deactivated aromatics in good yields and purity.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=26350323

Industrial & engineering chemistry research / Paul, Donald R. . Vol. 51 N° 36

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