Catalogue en ligne Bibliothèque Ecole Nationale Polytechnique d'Alger

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12150–12153

Titre :	Liquid organic hydrogen carriers : An upcoming alternative to conventional technologies. thermochemical studies.
Type de document :	texte imprimé
Auteurs :	Sergey P. Verevkin, Auteur ; Vladimir N. Emel’yanenko, Auteur ; Andreas Heintz, Auteur
Année de publication :	2012
Article en page(s) :	pp. 12150–12153
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Hydrogen Thermochemical
Résumé :	A system based on the catalytic hydrogenation/dehydrogenation reactions of N-ethylcarbazole is one of the most promising as the new class of the liquid organic hydrogen carrier (LOHC) compounds. Enthalpy of formation of the liquid dodecahydro-N-ethylcarbazole (fully hydrogenated N-ethylcarbazole) was measured using combustion calorimetry. Vaporization enthalpy for this compound was derived from vapor pressure–temperature dependence measured by transpiration. The enthalpy of formation of the gaseous dodecahydro-N-ethylcarbazole was derived and validated with the high-level quantum chemical calculation. Vapor pressures of the liquid N-ethylcarbazole (0.0008 bar) and dodecahydro-N-ethylcarbazole (0.01 bar) at a practical and relevant temperature (400 K) were assessed from the new experimental data. It has turned out that these vapor pressures were low enough to fulfill the basic requirement for an LOHC.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301898m

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12145–12149

Titre :	Polyacrylates with high biomass contents for pressure - sensitive adhesives prepared via mini - emulsion polymerization
Type de document :	texte imprimé
Auteurs :	Gang Pu, Auteur ; Matthew R. Dubay, Auteur ; Jiguang Zhang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 12145–12149
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Polyacrylates Biomass
Résumé :	n-Butyl acrylate and other acrylic monomers were copolymerized with an acrylated macromonomer to produce polymers for pressure-sensitive adhesive (PSA) applications. Macromonomers were generated through the ring-opening copolymerization of l-lactide and ε-caprolactone with 2-hydroxyethyl methacrylate (HEMA) at an average molar composition of 5:4:1, respectively. Conversion in the mini-emulsion polymerization was followed using Raman spectroscopy and was nearly complete within 2 h. Testing of these adhesive polymers indicates that performance properties meet or exceed those of commercial water-based acrylic PSAs.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301492v

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12135–12144

Titre :	Extension of the UNIFAC model for ionic liquids
Type de document :	texte imprimé
Auteurs :	Zhigang Lei, Auteur ; Chengna Dai, Auteur ; Xing Liu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 12135–12144
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Extension Ionic Liquids
Résumé :	The UNIFAC model has recently become very popular for ionic liquids (ILs) because of its applicability for prediction of thermodynamic properties. This work is a continuation of our studies on the extension of group parameters of the UNIFAC model to systems with ILs. The new IL groups for 33 main groups and 53 subgroups were added into the current UNIFAC parameter matrix. The parameters of group surface area and volume for ILs were obtained by the COSMO calculation, while the group binary interaction parameters, anm and amn, were obtained by means of correlating the activity coefficients of solutes at infinite dilution in ILs at different temperatures exhaustively collected from literature by the end of 2011. The predicted results of UNIFAC model are more accurate than those of the COSMO-RS model so that it can be used for identifying the general relationship between molecular structure of ILs and separation performance for the separation of liquid mixtures with ILs.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301159v

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12126–12134

Titre :	Precipitation of piperazine in aqueous piperazine solutions with and without CO2 loadings
Type de document :	texte imprimé
Auteurs :	Xiaoguang Ma, Auteur ; Inna Kim, Auteur ; Ralf Beck, Auteur
Année de publication :	2012
Article en page(s) :	pp. 12126–12134
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Piperazine Crystallization
Résumé :	The crystallization of piperazine in water as well as in systems loaded with CO2 has been studied for piperazine concentrations of 30–70 wt %, representing conditions relevant for CO2 capture. The use of a LabMax reactor system equipped with probes for in situ focused beam reflectance measurement (FBRM) and particle vision measurement (PVM) made it possible to determine solid–liquid transitions, crystal habit, and chord length distributions in these highly concentrated systems without disturbing the solid–liquid–gas equilibrium during crystallization. As shown by powder X-ray diffraction analysis, three phases including piperazine hemihydrate, piperazine hexahydrate, and anhydrous crystals were precipitated from the aqueous piperazine solutions at different concentrations and temperatures, as also supported by findings from FBRM and PVM. It was found that the metastable zone widths of the piperazine–H2O system were substantial even at the lower cooling rates, which could allow for a higher tolerance with respect to cooling prior to a new carbon dioxide absorption cycle. However, the eutectic composition exhibits a smaller metastable zone width than the other concentrations, which is believed to be caused by the precursor needle-shaped crystals, assisting the precipitation of the final product.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301101q

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12117–12125

Titre :	Assessment of stability of spouted bed using pressure fluctuation analysis
Type de document :	texte imprimé
Auteurs :	Palash Kumar Mollick, Auteur ; Dakshinamoorthy Sathiyamoorthy, Auteur
Année de publication :	2012
Article en page(s) :	pp. 12117–12125
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Analysis pressure fluctuation
Résumé :	Spouted beds are widely used in many industrial applications for achieving good gas–solid contact/mixing especially for a bed of coarse/nonspherical particles. The stability of the spouted bed is important and critical for certain sensitive applications like coating, blending, catalytic conversion, etc. This paper presents the results of experimental investigations carried out using both two-dimensional and three-dimensional spouted beds to identify various transition velocities and condition to arrive at a stable spouted bed. Standard deviation and power spectral density (PSD) of pressure fluctuation were used to determine the stable operating fluidization/spouting velocity. Zirconia microspheres were used as the spouted bed material and argon, nitrogen, and methane were used as spouting gases. Standard deviation of pressure fluctuation was calculated at minimum spouting velocity and at a velocity corresponding to transition from stable spouting to unstable spouting condition. It is shown that standard deviation of pressure fluctuation and PSD varies with various spouting gases and seen to follow a trend with Archemedes number of a given gas–solid system.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300950p

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12107–12116

Titre :	Bubble size and frequency in corrugated - wall bubbling fluidized beds — image analysis and neural network correlations
Type de document :	texte imprimé
Auteurs :	A. N. Khan Wardag, Auteur ; F. Larachi, Auteur ; B.P.A. Grandjean, Auteur
Année de publication :	2012
Article en page(s) :	pp. 12107–12116
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Bubbling dynamics
Résumé :	Digital image analysis was implemented to monitor bubbling dynamics in corrugated-wall bubbling fluidized beds (CWBFB) loaded with Geldart D particles. Various geometrical configurations were investigated in terms of corrugation angle, interwall clearance, and rest bed height and gas superficial velocity. Implementation of wall corrugation led to improved gas–solid fluidization quality with respect to flat-wall bubbling fluidized beds (FWBFB) as measured in terms of retreat of the onset of bubbling as a function of gas flow rate, of reduction of bubble sizes and rise velocities, and of increase of bubble frequency. Two artificial neural network correlations valid both for FWBFB and CWBFB were recommended for estimation of bubble frequency and size using a common set of independent variables, that is, gas superficial-minimum bubbling velocity ratio, bed rest height, corrugation angle, average clearance, and vertical location. The bubble frequency explicit correlation accounted additionally for interwall minimum clearance and distance between side wall and either neck or hip of front plate, at a given elevation, whereas bubble size correlation needed bubble frequency as a supplementary input variable.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3007775

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12095–12106

Titre :	Adsorption of anionic - azo dye from aqueous solution by lignocellulose - biomass jute fiber : Equilibrium, kinetics, and thermodynamics study
Type de document :	texte imprimé
Auteurs :	Aparna Roy, Auteur ; Sumit Chakraborty, Auteur ; Sarada Prasad Kundu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 12095–12106
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Adsorption Aqueous solution Kinetics Thermodynamics
Résumé :	The present investigation describes the evaluation of feasibility of lignocellulosic-biomass jute fiber (JF) toward adsorptive removal of anionic-azo dye from aqueous solution. Batch studies illustrated that dye uptake was highly dependent on different process variables, pH, initial dye concentration of solution, adsorbent dosage, and temperature. Further, an attempt has been taken to correlate these process variables with dye absorption and was optimized through a full-factorial central composite design (CCD) in response surface methodology (RSM). Maximum adsorption capacity (29.697 mg/g) under optimum conditions of variables (pH 3.91, adsorbent dose 2.04 g/L, adsorbate concentration 244.05 mg/L, and temperature 30 °C), as predicted by RSM, was found to be very close to the experimentally determined value (28.940 mg/g). Exothermic and spontaneous nature of adsorption was revealed from thermodynamic study. Equilibrium adsorption data were highly consistent with Langmuir isotherm yielding R2 = 0.999. Kinetic studies revealed that adsorption followed pseudo second-order model regarding the intraparticle diffusion. Activation parameters for the adsorption process were computed using Arrhenius and Eyring equations. Maximum desorption efficiency of spent adsorbent was achieved using sodium hydroxide solution (0.1 M).
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301708e

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12089–12094

Titre :	Solution chemistry of sodium silicate and implications for pyrite flotation
Type de document :	texte imprimé
Auteurs :	Bo Feng, Auteur ; Yiping Lu, Auteur ; Qiming Feng, Auteur
Année de publication :	2012
Article en page(s) :	pp. 12089–12094
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Solution chemistry
Résumé :	The solution chemistry of sodium silicate and implications for pyrite flotation have been studied. In addition to flotation and sedimentation tests, electrophoresis, inductively coupled plasma (ICP) tests, and X-ray photoelectron spectroscopy (XPS) have been used. The flotation and sedimentation results show that lizardite causes problems in the flotation of pyrite by adhering to the pyrite particles. Addition of the sodium silicate could make the mixed sample of pyrite and lizardite more disperse in the alkaline condition and significantly reduce the adverse effect of lizardite on the flotation of pyrite. ICP tests and XPS analysises show that sodium silicate can adsorb onto the lizardite surface and change the surface characteristic of lizardite. Sodium silicate mainly exists in the form of SiO(OH)3– in the pH range that sodium silicate can restore pyrite flotation recovery. The adsorption of SiO(OH)3– ions at the lizardite/solution interface overcompensates the positive charge on the lizardite particle and its ζ potential is rendered negative. The total interaction energy between lizardite and pyrite is changed from attractive energy to repulsive energy in the presence of sodium silicate, according to the calculation of the Derjaguin–Landau–Verwey–Overbeek theory.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301307a

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12081–12088

Titre :	Dynamics of CO2 absorption and desorption processes in alkanolamine with cosolvent polyethylene glycol
Type de document :	texte imprimé
Auteurs :	Jun Li, Auteur ; Chenjia You, Auteur ; Lifang Chen, Auteur
Année de publication :	2012
Article en page(s) :	pp. 12081–12088
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Dynamics Absorption
Résumé :	To reduce the high energy consumption and equipment corrosion in conventional processes of CO2 capture with aqueous amine solutions, the mixed nonaqueous solvents of monoethanolamine (MEA), diethanolamine (DEA), and diglycolamine (DGA) with polyethylene glycol (PEG) as cosolvent were explored for CO2 capture. The dynamic experiments of CO2 absorption and desorption were carried out to evaluate the performance of the studied nonaqueous solutions. It demonstrated that the mixed solutions of amines and PEG exhibited higher CO2 cyclic capacity and regeneration efficiency compared with the only aqueous amine solutions. Especially, the solution of 3 mol/L DGA-PEG200 exhibits a high cyclic capacity of 0.438 mol CO2/mol DGA and a high regeneration efficiency of 94.6%, which indicates its great potential in industrial application. Moreover, the very low vapor pressure of PEG helps the mixed solution for CO2 capture with reduced corrosion, energy consumption, and environmental pollution.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301164v

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp 12073–12080

Titre :	High - flux MFI zeolite membrane supported on YSZ hollow fiber for separation of ethanol / water
Type de document :	texte imprimé
Auteurs :	Xiaojun Shu, Auteur ; Xuerui Wang, Auteur ; Qingqing Kong, Auteur
Année de publication :	2012
Article en page(s) :	pp 12073–12080
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Zeolite Ethanol
Résumé :	Pure-silica MFI zeolite (silicalite-1) membranes exhibit great potential in the separation of an ethanol/water mixtures. For synthesis of silicalite membranes, however, conventional supports such as α-Al2O3 and mullite have aluminum element leaching out and entering into a zeolite structure, which would reduce the hydrophobicity of the zeolite layer and thus affect the separation performance for ethanol selectivity. In this paper, we prepared silicalite membranes on hollow fiber substrates fabricated with yttria stabilized zirconia (YSZ) without aluminum. The influence of seed size, synthesis parameters, and substrates was investigated. The as-synthesized membranes were characterized by scanning electron microscopy (SEM), electron probe microanalyzer (EPMA), infrared spectrum analysis (IR), and X-ray diffraction (XRD). A thin MFI zeolite layer with a thickness of about 3 μm could be formed on the support, which exhibited highly selective to ethanol over water. A high flux of 7.4 kg m–2 h–1 with the separation factor (ethanol/water) of 47 was achieved on the as-made membrane for separating 5 wt % ethanol/water at 60 °C.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301087u

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12065–12072

Titre :	Study on mass transfer - reaction kinetics of NO removal from flue gas by using a UV / fenton - like reaction
Type de document :	texte imprimé
Auteurs :	Yangxian Liu, Auteur ; Jianfeng Pan, Auteur ; Zhang, Jun, Auteur
Année de publication :	2012
Article en page(s) :	pp. 12065–12072
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Mass transfer Kinetics
Résumé :	The mass transfer-reaction kinetics of NO removal from flue gas by using a UV/Fenton-like reaction was investigated in a lab-scale UV-bubbling column reactor. The results show that the NO absorption rate increases with the increase of UV radiation intensity and H2O2 concentration, but the growth rates become smaller gradually. NO absorption rates increase with the increase of Cu2+ concentration and NO concentration but decrease with the increase of SO2 concentration. The absorption of NO by using a UV/Fenton-like reaction is a pseudo-first-order fast reaction with respect to NO, thus the chemical reaction rate of NO removal is much larger than the mass transfer rate, and the mass transfer process is the main control step of the NO absorption process. NO absorption can be further strengthened by increasing the gas phase mass transfer coefficient, the gas–liquid specific interfacial area, and the NO partial pressure. The validation results of the NO absorption rate equation indicate that the calculated values are in good agreement with the experimental values. The maximal average error is less than 2.0%, and the maximal error is less than 10.1% between the calculated values and the experimental values.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300883f

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12058–12064

Titre :	Investigation of mass - transfer performance for CO2 absorption into diethylenetriamine (DETA) in a randomly packed column
Type de document :	texte imprimé
Auteurs :	Kaiyun Fu, Auteur ; Teerawat Sema, Auteur ; Zhiwu Liang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 12058–12064
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Mass transfer CO2 Absorption
Résumé :	The mass-transfer performance of CO2 absorption into aqueous diethylenetriamine (DETA) solutions was investigated in an absorption column randomly packed with Dixon rings at 303–303 K and atmospheric pressure, and compared with that of monoethanolamine (MEA), which is widely considered as a benchmark solvent for CO2 absorption. The mass-transfer performance was presented in terms of volumetric overall mass-transfer coefficient (KGav). In particular, the effects of operating parameters, such as inlet CO2 loading, solvent concentration, liquid flow rate, inert gas flow rate, and liquid temperature, were investigated and compared for both MEA and DETA. Over 40 runs of absorption experiments were carried out in this study. The results showed that KGav of DETA was found to be higher than that of MEA. Also, inlet CO2 loading, solvent concentration, liquid flow rate, and liquid inlet temperature had significant effect on KGav for both systems. However, the inert gas flow rate had an insignificant effect on KGav. Lastly, predictive correlations for KGav for DETA–CO2 and MEA–CO2 systems in randomly Dixon ring packed columns were successfully developed. The predicted results were found to be in relatively good agreement with the experimental results, with average absolute deviations (AADs) of 16% and 14%, respectively.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300830h

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12046–12057

Titre :	Comparison of dimethyl disulfide and carbon disulfide in sulfurization of activated carbons for producing mercury adsorbents
Type de document :	texte imprimé
Auteurs :	Neda Asasian, Auteur ; Tahereh Kaghazchi, Auteur
Année de publication :	2012
Article en page(s) :	pp. 12046–12057
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Activated carbons Adsorbents
Résumé :	In this work, the use of dimethyl disulfide (DMDS) as a sulfurizing impregnator for producing mercury adsorbents for the first time has been investigated and compared with CS2, one of the materials commonly used in this field. Sulfurized adsorbents were characterized by CHNS/O elemental analysis, N2 adsorption/desorption, XPS, and FT-IR spectroscopy. The sulfur contents of CS2 and DMDS modified activated carbons were about 3.2 and 9.6 wt %, respectively. The impregnated sulfur was found in two major organic and elemental forms in granular activated carbon modified with DMDS; however, elemental sulfur was not observed in the case modified with CS2. After comparing the equilibrium capacities and the rates of mercury adsorption, the occurrence of sulfur leaching from the sulfurized adsorbents during the adsorption processes was studied.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3001474

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12041–12045

Titre :	Process and cost modeling of saturated branched - chain fatty acid isomer production
Type de document :	texte imprimé
Auteurs :	Helen L. Ngo, Auteur ; Winnie C. Yee, Auteur ; Andrew J. McAloon, Auteur
Année de publication :	2012
Article en page(s) :	pp. 12041–12045
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Modeling Acid Isomer
Résumé :	For decades, lubricants and hydraulic fluids were almost entirely based on petroleum. In recent years, the potential health risks of these materials as a result of their poor biodegradability have stimulated public awareness and concerns. It is therefore becoming increasingly important to implement environmentally friendly biobased fluids for the chemical industries. The development of new heterogeneous chemocatalytic processes for the conversion of vegetable oils and animal fats into high-value biobased industrial products can also have important positive impacts on the U.S. agriculture industry. Saturated branched-chain fatty acid isomers (sbc-FAs) such as isostearic acid, which are produced from renewable materials, are of interest because of their excellent lubricity and potentially good biodegradability. These unique features make them attractive in many important applications. Currently, sbc-FAs are produced as a byproduct of industrial dimer acid production, are synthesized in small quantities, and are costly to produce. In this paper, an efficient and effective isomerization process that produces predominantly the sbc-FA materials is presented as a case study to evaluate the potential of the technology to be implemented on the industrial scale. The case study was simulated using SuperPro Designer software to estimate the capital and process costs for producing sbc-FAs at an annual production of 4.5 × 106 kg (10 × 106 lb). The studies show that the process is cost-effective, with an estimated production cost of U.S. $2.53 kg–1 ($1.15 lb–1).
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300451x

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12031–12040

Titre :	Diblock poly(ester) - poly (ester - ether) copolymers : I. Synthesis, thermal properties, and degradation kinetics
Type de document :	texte imprimé
Auteurs :	Nowsheen Goonoo, Auteur ; Archana Bhaw-Luximon, Auteur ; Gary L. Bowlin, Auteur
Année de publication :	2012
Article en page(s) :	pp. 12031–12040
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Thermal Properties Kinetics
Résumé :	The synthesis and characterization of polycaprolactone (PCL) and poly(dioxanone-methyl dioxanone) (P(DX-co-MeDX)) block copolymers in a range of compositions of the two segments and with varying methyl dioxanone units is herein reported. The thermal properties of the copolymers were studied by differential scanning calorimetry (DSC) which revealed that copolymers exhibited two melting transitions ranging between 48 and 53 °C for the PCL segment and 71–79 °C for the P(DX-co-MeDX) segment. Copolymers exhibited only one crystallization exotherm which decreased as the MeDX content of the copolymer increased, thereby increasing miscibility of PCL and P(DX-co-MeDX) segments, a result also confirmed by scanning electron micrographs (SEM). Lastly, the kinetics of thermal degradation of PCL-b-P(DX-co-MeDX) copolymers were investigated by thermogravimetric analysis (TGA). Thermal degradation was shown to proceed in three distinct steps with the P(DX-co-MeDX) segment degrading in the first stage followed by the PCL segment in the last two stages most likely via unzipping and random polymerization mechanisms. The activation energies of copolymer degradation were determined and were found to decrease with increasing MeDX content of the copolymer. Overall, increasing MeDX content influenced both thermal properties and degradation kinetics through phase mixing of segments in the copolymers.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301703j

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012)

Titre :	A General phase - transfer protocol for mineral acids and its application in the large - scale synthesis of highly nanoporous iron phosphate in nonaqueous solvent
Type de document :	texte imprimé
Auteurs :	Junmei Zhao, Auteur ; Jie Ma, Auteur ; Zelang Jian, Auteur
Année de publication :	2012
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Nanoporous Iron
Résumé :	As a general protocol for transferring mineral acids from an aqueous solution to an organic phase, mineral acids are extracted with secondary carbon primary amine (C9–11)2CHNH2 (commercial code: N1923) into an organic phase (e.g., heptane or benzene) because of the complexation reaction and the formation of typical reversed micelles. Based on this principle, a novel approach for a large-scale synthesis of highly nanoporous iron phosphate particles is developed via the formed RNH3+/H2PO4– (H2O)/oil reversed micelle system and ethanol–Fe3+ solutions. Synthetic conditions, such as H3PO4 concentration in reversed micelles and Fe3+ concentration in ethanol–Fe3+ solution are investigated and optimized. The product is characterized using transmission electron microscopy, Brunauer–Emett–Teller, thermogravimetric analysis, X-ray diffraction, and Fourier transform infrared spectroscopy. The as-obtained iron phosphate is flocculent and highly porous, exhibiting a high reported surface area of 144 m2/g. The synthetic procedure is relatively simple and is suitable for large-scale fabrication, and the used organic amines can be recycled. The power of this approach is demonstrated using other kinds of organic amines, such as tri-n-octylamine (TOA) and tri-C8–10-alkylmethyl ammonium chloride (N263), as phase-transfer reagents exhibiting promising application in the synthesis of highly nanoporous materials.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3016285

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12017–12024

Titre :	Facile approach for superparamagnetic CNT - Fe3O4 / polystyrene tricomponent nanocomposite via synergetic dispersion
Type de document :	texte imprimé
Auteurs :	Wu Zhong, Auteur ; Peng Liu, Auteur ; Zhaobin Tang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 12017–12024
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Nanocomposite Synergetic dispersion
Résumé :	A facile one-pot in-situ radical bulk polymerization strategy was developed for preparation of the superparamagnetic multiwalled carbon nanotubes-Fe3O4/polystyrene (CNT-Fe3O4/PS) tricomponent nanocomposite by the synergetic dispersion strategy via the multiwalled carbon nanotubes (CNT) immobilized Fe3O4 nanoparticles (CNT-Fe3O4) with oleic acid (OA) as surface modifier. Compared with the tricomponent nanocomposite prepared with the multiwalled carbon nanotubes and Fe3O4 nanoparticles added separately, immobilization of Fe3O4 nanoparticles on multiwalled carbon nanotubes could avoid efficiently aggregation of the Fe3O4 nanoparticles in polymer matrices. OA molecules adsorb onto the surfaces of the Fe3O4 nanoparticles immobilized on the multiwalled carbon nanotubes, improving efficiently the dispersibility of the multiwalled carbon nanotubes in styrene, which resulted in the well-dispersed CNT-Fe3O4/PS tricomponent nanocomposite.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300891h

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12009–12016

Titre :	Thermal degradation and flame retardance of biobased polylactide composites based on aluminum hypophosphite
Type de document :	texte imprimé
Auteurs :	Gang Tang, Auteur ; Xin Wang, Auteur ; Weiyi Xing, Auteur
Année de publication :	2012
Article en page(s) :	pp. 12009–12016
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Thermal behavior Polylactide
Résumé :	A series of flame retardant polylactide composites (FR-PLA) based on aluminum hypophosphite (AHP) were facilely prepared by melt blending method. The thermal behavior, flammability, and mechanical properties of FR-PLA composites were investigated by thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), the UL-94 vertical burning test, limiting oxygen index (LOI), cone calorimeter testing, microscale combustion calorimetry, mechanical testing, and dynamic mechanical analysis (DMA). TGA results showed that the FR-PLA composites presented higher char residue and reduced mass loss rate than neat PLA. The FR-PLA composite showed excellent fire resistance, from no rating of neat PLA to a V0 rating of FR-PLA containing 20 wt % aluminum hypophosphite in the UL-94 test. The microscale combustion calorimetry test showed that the heat release capacity, the peak of heat release and the total heat release of FR-PLA composites were significantly decreased with the increase of AHP content. The cone calorimeter test also confirmed that the addition of AHP resulted in a significant decrease in the peak heat release rate value of PLA/AHP composites compared with pure PLA. Additionally, the results from DSC and DMA tests indicated that the addition of AHP into polylactide significantly changed the crystallization behavior and storage modulus of polylactide. However, the addition of AHP decreases the tensile strength and elongation at break. The char after LOI testing was investigated by scanning electron microscopy and craterlike morphology was observed on the surface of the char. The thermal degradation process of FR-PLA composites was analyzed by real-time Fourier transform infrared spectroscopy.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3008133

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 12004–12008

Titre :	Combustion synthesis of a nickel supported catalyst : Effect of metal distribution on the activity during ethanol decomposition
Type de document :	texte imprimé
Auteurs :	Allison Cross, Auteur ; Anand Kumar, Auteur ; Eduardo E. Wolf, Auteur
Année de publication :	2012
Article en page(s) :	pp. 12004–12008
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Catalyst Ethanol
Résumé :	Solution combustion synthesis method is used to prepare Ni catalysts supported on γ-Al2O3 pellets with controlled metal distribution. It was shown that impregnation time of the SCS solution onto the pellet determines the distribution of the Ni in the pellet which in turn affects the catalyst selectivity toward hydrogen production during ethanol decomposition.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301478n

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11998–12003

Titre :	Selective degradation of orange II with the cobalt (II) – bicarbonate – hydrogen peroxide system
Type de document :	texte imprimé
Auteurs :	Xuejun Long, Auteur ; Zhen Yang, Auteur ; Hong Wang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11998–12003
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Catalyst
Résumé :	A simple and efficient approach to orange II (AOII) degradation using Co2+–HCO3– system as the catalyst and H2O2 as the oxidant under mild reaction conditions was reported. Complete decolorization of 50 μM AOII was observed with 5 μM Co2+ ions and 4 mM H2O2 in 10 mM NaHCO3 aqueous solution after 10 min, which was much faster that that of Fenton reagent with 50 μM Fe2+ ions. Some intermediate products such as carboxylic acids were detected by electrospray ionization-ion trap mass spectrometry and ion chromatography. In the presence of other pollutants such as methylene blue, sulforhodamine B, and a significant amount of anions including Cl–, CO32–, SO42–, NO3–, HPO42–, and CH3COO–, AOII was still rapidly degraded. The results of photoluminescence probing technology, electron spin resonance spin-trapping technology, and radical trap experiments indicated that the tightly associated hydroxyl radicals with the cobalt complex were the reactive species for AOII degradation.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3013924

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11989–11997

Titre :	Effect of sorbent type on the sorption enhanced water gas shift process in a fluidized bed reactor
Type de document :	texte imprimé
Auteurs :	Yang Liu, Auteur ; Zhenshan Li, Auteur ; Lei Xu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11989–11997
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Sorption water gas
Résumé :	reactions: the WGS reaction and the CaO carbonation reaction. The WGS reaction is a surface catalytic reaction, while the CaO carbonation is a bulk reaction. This study of the SEWGS reaction in a fluidized bed reactor showed that the sorbent type has an important effect on the SEWGS reaction, with both the CaO and MgO in the sorbent catalyzing the reaction. For calcined limestone, the WGS reaction occurs on the CaO surface with CO2 sorption in situ, but the reaction rate gradually decreases with the CaO conversion due to coverage by the CaCO3 product layer on the CaO surface. Thus, the shift reaction becomes the rate limiting step. For calcined dolomite, MgO in the sorbent does not react with CO2 and can then be used as a catalyst. The shift reaction is not a limiting step, with most of the CO2 for the CaO carbonation coming from the WGS reaction on the MgO surface. Even when the CaO surface is completely covered by the CaCO3 product, the MgO in the calcined dolomite is not completely covered by the CaCO3 product and can still catalyze the WGS reaction. An important phenomenon observed was that not only CaO but also MgO experienced the decay in the catalytic reactivity after multiple cycles. The decay of catalytic reactivity of MgO in dolomite is mainly the gradual covering of the MgO surface by CaO/CaCO3 grains, so most of the MgO grains will lose contact with the CO and the steam in the gas phase. The observation of encapsulation of MgO particles by CaO or CaCO3 is also important for understanding the stabilization of synthetic calcium based sorbent with support addition.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301100y

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11975–11988

Titre :	Reaction kinetics of the lignin conversion in supercritical water
Type de document :	texte imprimé
Auteurs :	Tau Len-Kelly Yong, Auteur ; Yukihiko Matsumura, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11975–11988
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Kinetics
Résumé :	The effect of temperature (390–450 °C) and residence time (0.5–10 s) at a pressure of 25 MPa was investigated for lignin conversion in supercritical water (SCW) using a continuous flow apparatus designed to rapidly heat the system to the desired reaction temperature. Conversion of lignin in SCW occurs rapidly, and complete depolymerization can be achieved within a 5 s residence time. A high degree of depolymerization is achieved from rapid heating to supercritical temperatures. In addition, supercritical conditions result in a high yield of solid that does not significantly change with an increase in temperature or residence time. To test the suggested hypothesis that the formation of low molecular weight fragments and cross-linking of these fragments forms higher molecular weight fragments, the yield of char, gaseous products, phenolic compounds (phenol, guaiacol, catechol, o-cresol, m-cresol, and catechol) and aromatic hydrocarbons (benzene, toluene, and naphthalene) were determined. The formation of phenolic compounds at short residence time indicates that ether bonds in lignin are easily degraded under supercritical conditions. A reaction network model was proposed, and the subsequent kinetic parameters for the conversion pathways were determined by assuming a first-order reaction. It is observed that the rate constant of overall lignin conversion obeys Arrhenius behavior. The individual rate constants of each reaction in the network are evaluated to determine conformity to Arrhenius behavior.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300921d

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11965–11974

Titre :	Esterification of acetic acid with n - hexanol in batch and continuous chromatographic reactors using a gelular ion - exchange resin as a catalyst
Type de document :	texte imprimé
Auteurs :	Dipesh Patel, Auteur ; Basudeb Saha, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11965–11974
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Ion exchange Catalyst
Résumé :	Heterogeneously catalyzed esterification reactions of acetic acid and n-hexanol were studied in batch and continuous chromatographic reactors in the presence of a gelular ion-exchange resin catalyst (Purolite CT-124) to synthesize a value added ester, namely n-hexyl acetate. A laboratory scale batch chromatographic reactor column (BCRC) was designed and constructed. BCRC experiments were carried out using different parameters such as feed flow rate, feed mole ratio (FMR) of n-hexanol to acetic acid, desorbent (n-hexanol) flow rate, and reaction step time to maximize the formation of n-hexyl acetate as well as to achieve complete conversion of acetic acid. Samples were collected from the chromatographic reactor column (CRC) outlet at regular intervals and were analyzed by gas chromatography (GC). The continuous chromatographic reactor column (CCRC) was designed, constructed, and commissioned on the basis of the results obtained from the BCRC experiments. The experiments carried out in a CCRC correlate very well with the results obtained from the optimized reaction condition in a BCRC for maximum formation of n-hexyl acetate and complete conversion of acetic acid.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3007424

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11955–11964

Titre :	Mechanistic modeling of cobalt based catalyst sintering in a fixed bed reactor under different conditions of fischer – tropsch synthesis
Type de document :	texte imprimé
Auteurs :	Majid Sadeqzadeh, Auteur ; Jingping Hong, Auteur ; Pascal Fongarland, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11955–11964
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Catalyst
Résumé :	A three-step sintering mechanism is proposed for Co-based catalysts under Fischer–Tropsch reaction conditions. This mechanism includes an intermediate formation of oxide layer on cobalt metal nanoparticles in the presence of water. The partially reversibly oxidized surface accelerates sintering by both reducing the surface energy and enhancing the diffusion rates of cobalt particles. The proposed mechanism is then employed for a fixed-bed unsteady state reactor. The effect of particle growth on the catalytic activity was analyzed within a diverse range of operating conditions (syngas ratio = 1.5–4, water co-feed ratio = 0–6, inert co-feed ratio = 0–6). It is found that, at the same gas space velocity, sintering proceeds faster at higher H2/CO ratios. At the same initial conversion, a low H2/CO syngas ratio increases sintering severity, i.e., catalyst deactivation due to the crystallite growth, as it brings about higher relative water partial pressure. Dilution of syngas with different amounts of inert gas does not affect the cobalt sintering rate. Cobalt sintering proceeds more rapidly if water is co-fed during the reaction.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3006929

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11946–11954

Titre :	Semi - IPN chitosan / PEG microspheres and films for biomedical applications : Characterization and sustained release optimization
Type de document :	texte imprimé
Auteurs :	Ismail Dogan Gunbas, Auteur ; Umran Aydemir Sezer, Auteur ; Sultan Gulce iz, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11946–11954
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Microspheres Optimization
Résumé :	Micro drug carriers are one of the efficient methods for local or systemic cancer treatment. In this study, the aim was to prepare a novel semi-interpenetrated (semi-IPN) micro system by using biocompatible chitosan (CH) and polyethylene glycol (PEG). Various combinations of the systems were prepared and loaded with a model chemotherapeutic drug, methotrexate (MTX), and the effects of composition on the properties and the release behavior of microspheres were examined. Also, the mechanical and thermal properties were examined on film forms of similar compositions. Increase in cross-linking caused a decrease in particle size of CH from 144 to 91 μm, while the addition of PEG caused an increase up to 163 μm. Elastic modulus values of the films first increased and then decreased parallel to PEG content. In vitro studies showed faster MTX release from semi-IPN CH-PEG microspheres as compared to pure CH ones. Promising results were obtained in the development of biodegradable drug vehicles.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3015523

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11941–11945

Titre :	Antiwear additive derived from soybean oil and boron utilized in a gear oil formulation
Type de document :	texte imprimé
Auteurs :	Brajendra K. Sharma, Auteur ; Kenneth M. Doll, Auteur ; Glenn L. Heise, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11941–11945
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Lubricant additives
Résumé :	The synthesis of lubricant additives based on boron and epoxidized soybean oil are presented. These additives are made from a simple patent pending method involving a ring-opening reaction of the epoxidized oil. A couple of these borates were tested in soybean oil, polyalpha olefin basestock, group III basestock, and hexadecane. An aromatic additive was able to increase the oxidation onset of the basestocks by 14, 52, 48, and 49 °C, respectively, when used at 2% wt. The other additive was shown to reduce the wear scar diameter in a friction test when used in soybean oil basestock, from 0.61 mm down to 0.41 mm. These additives were also tested in a gear oil blend, and shown to reduce both wear and oxidation. They were also compatible with a popular additive, additive zinc dialkyl dithiophosphate.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301519r

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11931–11940

Titre :	High efficiency multijunction photovoltaic development
Type de document :	texte imprimé
Auteurs :	David Wilt, Auteur ; Mark Stan, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11931–11940
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Multijunction Photovoltaic
Résumé :	Photovoltaic energy conversion has demonstrated remarkable improvements in performance over the past 60 years. The rate of solar cell efficiency change has actually increased over the past 20 years as researchers have moved beyond elemental semiconductors to increasingly more sophisticated materials and devices. In addition, significant improvements in materials quality and deposition technology have further fueled this dramatic improvement in device performance. Diversifying from silicon to III–V compound semiconductor materials has enabled the development of multijunction solar cells with 3, 4, and even 6 subcells to achieve ever higher conversion efficiency. For 1-sun space application(s), these III–V multijunction cells are demonstrating 35% efficiency, while under terrestrial concentrated sunlight conditions efficiencies are >42%. This Article will discuss the development of high efficiency III–V multijunction solar cells, focusing on recently developed metamorphic device structures and novel lattice matched approaches.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3012616

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11924–11930

Titre :	Predicting pKa of amines for CO2 capture : Computer versus pencil - and - paper
Type de document :	texte imprimé
Auteurs :	Kazi Z. Sumon, Auteur ; Amr Henni, Auteur ; Allan L. L. East, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11924–11930
Note générale :	Industrial chmistry
Langues :	Anglais (eng)
Mots-clés :	Amines CO2 Capture
Résumé :	For pKa prediction of aliphatic amines (amines relevant to industrial CO2 capture), the performance of quantum-chemistry continuum-solvation methods is contrasted with the 1981 pencil-and-paper group-additivity method of Perrin, Dempsey, and Serjeant (PDS). We have optimized a quantum-chemistry continuum-plus-correction strategy, as well as updated the parameter values in the PDS method. The PDS method outperformed the continuum-based method: root-mean-square errors for a sample of 32 amines are 0.28 for the continuum-based method, 0.33 for the original PDS method, and 0.18 for the updated PDS method. Considering also that there is ambiguity in choice of cavity radii and molecular conformer for continuum-based methods, we recommend the pencil-and-paper PDS method over such methods.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301033p

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11914–11923

Titre :	Production and application properties of dispersive viscosity index improvers
Type de document :	texte imprimé
Auteurs :	Ivana Soljic Jerbic, Auteur ; Jelena Parlov Vukovic, Auteur ; Ante Jukic, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11914–11923
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Dispersive viscosity
Résumé :	Polymeric dispersive viscosity index improvers of lubricating mineral oils based on styrene, dodecyl-methacrylate, octadecyl methacrylate, and N,N-dimethylaminoethyl methacrylate (d-PSAMA) were produced by performing copolymerizations isothermally up to the high conversion in mineral base oil solution, using monofunctional or bifunctional peroxide initiator. The obtained kinetics results reveal the benefits of the usage of a bifunctional peroxide initiator over a monofunctional, because complete conversion of monomers was accomplished in the shorter reaction time, performing the process in a full batchwise mode. When the bifunctional initiator was applied, the required polymerization temperature was slightly higher (105 °C), and copolymers of higher average molecular weight values (Mw = 60–120 kg mol–1) were obtained, while in case of the monofunctional peroxide initiator, the reaction temperature was 100 °C, and average molecular weight values of copolymers were Mw = 30–100 kg/mol. Investigated application properties demonstrated that d-PSAMA additives were fully comparable with conventional pure methacrylate additives, and also it provided other advantages such as higher viscosity index and kinematic viscosity, lower values of pour point temperatures, as well as better dispersant and detergent properties. Thus, by increasing the N,N-dimethylaminoethyl methacrylate share in copolymers from 2 to 10 mol %, their weight average molecular weight decreased from 120 to 60 kg mol–1, while kinematic viscosity values at 100 °C remain high and amounted to 14.5 ± 0.5 mm2 s–1.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie301010n

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11901–11913

Titre :	Selective recovery of precious metals from acidic leach liquor of circuit boards of spent mobile phones using chemically modified persimmon tannin gel
Type de document :	texte imprimé
Auteurs :	Manju Gurung, Auteur ; Birendra Babu Adhikari, Auteur ; Hidetaka Kawakita, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11901–11913
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Precious metals Acidic leach
Résumé :	A tannin-based novel adsorbent, named “BTU-PT gel”, was prepared by immobilizing bisthiourea (BTU) ligand on persimmon tannin (PT) extract. The adsorption behaviors of precious metal ions along with other coexisting base metal ions onto BTU-PT gel were studied by batch and continuous column methods. The gel exhibited remarkable selectivity for precious metal ions such as Au(III), Pd(II), and Pt(IV) over base metal ions such as Cu(II), Fe(III), Ni(II), and Zn(II) in 1–5 mol dm–3 hydrochloric acid. The adsorption of precious metal ions on the present gel was found to obey the typical monolayer type of Langmuir model, and the maximum adsorption capacity of the adsorbent was evaluated as 5.18 mol kg–1 for Au(III), 1.80 mol kg–1 for Pd(II), and 0.67 mol kg–1 for Pt(IV). Combination of ion exchange, electrostatic interaction, and coordination through the thiocarbonyl group is the mechanism of adsorption of precious metals on BTU-PT gel. In the case of Au(III) adsorption, the adsorbed species was simultaneously reduced to elemental gold by abundant polyphenolic groups of the tannin matrix. Elution by using acidothiourea solution in continuous column experiment recovered the adsorbed precious metals almost quantitatively. The results of a potential reusability test of the gel for consecutive adsorption and elution cycles by continuous column experiment indicated that the gel was stable and regenerated with undiminished metal uptake capacity up to five cycles. The real time applicability of the adsorbent for the recovery of precious metals from real industrial liquor was evaluated from actual acidic leach liquor of printed circuit boards of spent mobile phones. The gel selectively adsorbed precious metal species but exhibited negligible affinity toward base metals present in the leach liquor. The BTU-PT gel is a potential adsorbent for selective recovery of precious metals from acidic leachate of spent mobile phones containing elevated concentrations of base metals.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3009023

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11892–11900

Titre :	Investigation of the structure and catalytic performance of highly dispersed Ni - based catalysts for the growth of carbon nanostructures
Type de document :	texte imprimé
Auteurs :	Muzi Li, Auteur ; Guoli Fan, Auteur ; Hua Qin, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11892–11900
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Catalysts Nanostructures
Résumé :	The in situ growth of Ni-containing layered double hydroxide (LDH) microcrystallites on microspherical γ-alumina support was carried out through the surface activation of support followed by a homogeneous coprecipitation process, and carbon nanomaterials were synthesized directly over as-grown supported LDH samples via catalytic chemical vapor deposition of acetylene. As compared to that prepared by the conventional impregnation, supported LDH samples calcined at 700 °C possessed higher metal dispersion, which was attributed to well-developed two-dimensional structure of LDH platelets uniformly grown on the support surface originating from the strong interaction between brucite-like lattices and support. Furthermore, the supported catalyst from NiAl-LDH could catalyze the growth of regular carbon nanofibers, while another one from NiMgAl-LDH exhibited excellent catalytic performance for the growth of uniform carbon nanotubes due to higher metal dispersion achieved by the separating effect of amorphous metal oxide (MgO and Al2O3) phases around Ni nanoparticles. As-synthesized supported Ni-based catalysts are promising for practical applications in the production of carbon nanostructures with uniform geometric shape.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3008659

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11881–11891

Titre :	Effect of nanoparticles on flammability, UV resistance, biodegradability, and chemical resistance of wood polymer nanocomposite
Type de document :	texte imprimé
Auteurs :	Biplab K. Deka, Auteur ; Manabendra Mandal, Auteur ; Tarun K. Maji, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11881–11891
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Nanoparticles Polymer
Résumé :	Wood polymer nanocomposite (WPNC) was developed by using high-density polyethylene (HDPE), low-density polyethylene (LDPE), polypropylene (PP), polyvinyl chloride (PVC), wood flour (WF), polyethylene-co-glycidyl methacrylate (PE-co-GMA), and different nanoparticles viz. nanoclay, SiO2, and ZnO. The distribution of nanoparticles was examined by X-ray diffraction (XRD) study. The change in surface morphology due to the addition of compatibilizer and nanoparticles was studied by scanning electron microscopy (SEM). The surface modification of nanoparticles by organic surfactant and their interaction with polymer and wood was studied by Fourier transform infrared spectroscopy (FTIR). The UV resistance property was improved after the incorporation of clay, SiO2, and ZnO. Bacterial degradation of WPC was found to increase linearly with the incorporation of clay and nanoparticles. The degraded samples showed lower mechanical properties. Flame retarding property, chemical resistance, and water vapor resistance were found maximum in WPC loaded with 3 phr each of clay, SiO2, and ZnO.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3003123

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11875–11880

Titre :	Exoskeleton of a mollusk (Pila globosa) as a heterogeneous catalyst for synthesis of biodiesel using used frying oil
Type de document :	texte imprimé
Auteurs :	Shweta Agrawal, Auteur ; Bhaskar Singh, Auteur ; Yogesh Chandra Sharma, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11875–11880
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Heterogeneous catalyst Biodiesel
Résumé :	A heterogeneous catalyst has been derived from a waste material (i.e., exoskeleton of mollusk) for transesterification of a waste feedstock (i.e., used frying oil (UFO)) for synthesis of biodiesel. The exoskeleton of mollusk shell was crushed, ground, and calcined at 900 °C to derive CaO as a heterogeneous catalyst. The catalyst was characterized by X-ray diffraction (XRD), Fourier transform infrared (FTIR) spectroscopy, X-ray fluorescence spectroscopy (XRF), and differential thermal analysis/thermogravimetric (DT/TG) analysis. The XRD peaks observed at 2θ = 31.80, 36.93, and 53.37° were characteristic of CaO and showed high crystallinity. The FTIR absorption bands of the calcined shell were observed at 1474, 870, and 502 cm–1, which are attributed to the vibration of CO32– molecules, and a sharp peak at 3640 cm–1 indicated the presence of OH– stretching due to Ca(OH)2. The XRF analysis demonstrated the Pila globosa shell to comprise 79.86% of calcium along with few minor elements (viz. Pd, I, Te, Sb, Sn, W, Al, Si, Sr, Cr, S). The (DT/TG) analysis showed the decomposition of calcium carbonate present in Pila globosa at 860 °C. The waste-driven substances (exoskeleton of mollusk as catalyst and UFO as feedstock) resulted in a high yield (92%) and conversion (97.8%) of biodiesel that was obtained at a 10:1 (methanol to oil) molar ratio, 4.0 wt % catalyst, at 60 ± 0.5 °C in 5 h reaction. The conversion of UFO to biodiesel was determined by 1H FT-NMR.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202404r

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11866–11874

Titre :	Intensification of synthesis of biodiesel from nonedible oils using sonochemical reactors
Type de document :	texte imprimé
Auteurs :	Vitthal L. Gole, Auteur ; Parag R. Gogate, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11866–11874
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Biodiesel
Résumé :	Biodiesel synthesis from nonedible oils, which offer excellent potential as sustainable feed stock, is highly energy-intensive and slow operation, because it requires considerable processing due to higher initial acid values and due to the fact that the reaction is mass-transfer-controlled. The present work reports the intensification of synthesis of biodiesel from the high-acid-value Nagchampa oil using sonochemical reactors. The synthesis process is a two-step method of esterification in the presence of homogeneous acid catalyst followed by transesterification using an alkaline (KOH) catalyst. The synthesis has also been attempted using conventional methods of reflux for analyzing the degree of intensification. With an objective of avoiding possible saponification reaction in the transesterification based on use of an alkaline catalyst, the acid value of oil was reduced from 18.4 mg KOH/g of oil to 1.4 mg KOH/g of oil, using the first-stage esterification method. The reduction in the acid value allows for an efficient second transesterification stage. The reaction temperature, molar ratio, and catalyst concentration were optimized for esterification and transesterification stages for the ultrasound and conventional techniques. It has been observed that the reaction temperature and reaction time required for esterification, as well as the transesterification stages, are substantially lower in the case of sonochemical reactors, compared to the conventional heating method. Also, the percentage excess of the reactants is significantly reduced, leading to energy savings in the subsequent separation processes for getting the purified product. Overall, the present work has clearly established the efficacy of sonochemical reactors for the intensification of biodiesel synthesis based on a sustainable raw material.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie2029442

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11860–11865

Titre :	Experimental and Modeling Study of Continuous Catalytic Transesterification to Biodiesel in a Bench-Scale Fixed-Bed reactor
Type de document :	texte imprimé
Auteurs :	Yang Xiao, Auteur ; Lijing Gao, Auteur ; Guomin Xiao, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11860–11865
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Catalytic Biodiesel
Résumé :	A 500 h endurance test of continuous catalytic transesterification to biodiesel was conducted in a bench-scale fixed-bed reactor. A designed cylinder shape of KF/Ca–Mg–Al hydrotalcite catalyst was stable through the test with high catalytic activity and mechanical strength, converting palm oil to biodiesel with a conversion of more than 95%. Conditions effects on transesterification under relative high pressure (1.0 MPa) were investigated and a one-dimensional heterogeneous model of a fixed-bed reactor was developed to describe the reaction-mass transfer behaviors of continuous catalytic transesterification in a bench-scale fixed-bed reactor. With the given reactor size, optimum conditions were proposed as a LHSV (liquid hourly space velocity) of 0.76–0.25 h–1, molar ratio of methanol-to-oil of 9.16–13.7, and temperature of 338–347 K.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202312z

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11850–11859

Titre :	Spectroscopic studies of light - driven water oxidation catalyzed by polyoxometalates
Type de document :	texte imprimé
Auteurs :	Zhuangqun Huang, Auteur ; Yurii V. Geletii, Auteur ; Djamaladdin G. Musaev, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11850–11859
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Spectroscopic Oxidation
Résumé :	This review is focused on the spectroscopic studies of the charge transfer dynamics in polyoxometalate (POM)-catalyzed artificial photodriven water oxidation systems. We first describe the general challenges in solar fuel production, showing that water oxidation catalysts (WOCs) are of central importance. After the introduction of a new class of highly efficient WOCs based on all-inorganic polyoxometalates, we summarize the performance of these WOCs in homogeneous water oxidation systems. We show that the individual steps involved in the overall light-driven water oxidation reaction can be investigated by spectroscopic techniques (fluorescence quenching, transient absorption, and stopped flow). These studies provide important insight into the factors that limit the overall conversion efficiency in these systems and suggest possible approaches for improving these devices.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202950h

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11841–11849

Titre :	Enhanced charge separation in nanostructured TiO2 materials for photocatalytic and photovoltaic applications
Type de document :	texte imprimé
Auteurs :	He He, Auteur ; Chao Liu, Auteur ; Kevin D. Dubois, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11841–11849
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Photocatalytic Photovoltaic
Résumé :	Titanium dioxide (TiO2) has been extensively investigated in solar energy applications, including heterogeneous photocatalysis and photovoltaics. For most TiO2 materials, charge recombination between photoexcited electrons and holes severely limits the efficiencies of solar energy conversion. Different strategies have been attempted to improve charge separation in TiO2 materials. This review focuses on three effective approaches to achieve enhanced charge separation by constructing mixed-phase TiO2, highly dispersed titanium oxides, and nanotubular TiO2 materials. Selected examples from the literature are discussed to demonstrate how the three approaches could be implemented in the context of photocatalytic water splitting, photocatalytic CO2 reduction, and dye-sensitized solar cells. The discussion provides useful insights regarding the design of new TiO2 nanostructures for use in solar energy conversion.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300510n

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11828–11840

Titre :	Review : Photochemical and thermochemical production of solar fuels from H2O and CO2 using metal oxide catalysts
Type de document :	texte imprimé
Auteurs :	Greg P. Smestad, Auteur ; Steinfeld, Aldo, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11828–11840
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Photochemical Thermochemical Production
Résumé :	Metal oxides are reviewed as catalysts to convert H2O and CO2 to fuels using solar energy. For photochemical conversion, TiO2 has been found to be the most stable and useful oxide material, but it is currently limited by its large bandgap and a mismatch between its conduction band and the redox couples for water splitting and CO2 reduction. A theoretical framework has been utilized to understand the basic thermodynamics and energetics in photochemical energy conversion systems. This is applied to model systems comprised of Ag2O and AgCl to examine why the former reacts thermochemically in air, while the latter reacts photochemically. For thermochemical conversion, zinc-, ceria-, and ferrite-based redox cycles are examined and examples of high-temperature solar reactors driven by concentrated solar radiation are presented. For CO2 splitting, theoretical solar-to-fuel energy conversion efficiencies can be up to 26.8% for photochemical systems, and can exceed 30% for thermochemical systems, provided that sensible heat is recovered between the redox steps.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie3007962

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 37 (Septembre 2012) . - pp. 11821–11827

Titre :	Hydrogen storage in perovskite - type oxides ABO3 for Ni / MH battery applications : A density functional investigation
Type de document :	texte imprimé
Auteurs :	Qiang Wang, Auteur ; Zhiqian Chen, Auteur ; Yungui Chen, Auteur
Année de publication :	2012
Article en page(s) :	pp. 11821–11827
Note générale :	Industrial chemistry
Langues :	Anglais (eng)
Mots-clés :	Hydrogen Oxides
Résumé :	Perovskite oxides were typically considered as the electronic and ionic conductors for application in the electrolytes for solid oxides fuel cells (SOFCs). Recently, LaFeO3-based systems were mainly focused on the electrochemical property for the anode of Ni/MH batteries in our previous work, and the exciting results of their electrochemistry capacity and cycle life examination exhibited much scientific values for further investigation. In the present work, the effects of A (La)-site or B (Fe)-site metal ions doped and substituted on the fundamental properties of these materials were calculated by a first-principle approach. In conjunction with the experimental results, the microscopic mechanisms of the doped or substituted effect were discussed and elucidated. On the other hand, the hydrides of LaFe(Cr)O3 were established and computed to explore the nature of electrochemical behaviors of these perovskite oxides.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202284z

Industrial & engineering chemistry research / Paul, Donald R. . Vol. 51 N° 37

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