Catalogue en ligne Bibliothèque Ecole Nationale Polytechnique d'Alger

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4463-4465

Titre :	Cyclodextrin inhibits calcium carbonate crystallization and scaling
Type de document :	texte imprimé
Auteurs :	Venous Derakhshanian, Auteur ; Sujit Banerjee, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4463-4465
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Crystallization
Résumé :	β-Cyclodextrin inhibits calcium carbonate crystallization and also reduces the degree of scaling on stainless steel surfaces. The rate of crystallization is not affected. The size of the calcium carbonate crystals is reduced by the cyclodextrin. Under the conditions used, the cyclodextrin was effective at concentrations between 5 ppm and 100 ppm.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25655656

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4458-4462

Titre :	Assessment of the antifouling properties of polyzwitterions from free energy calculations by molecular dynamics simulations
Type de document :	texte imprimé
Auteurs :	Ryo Nagumo, Auteur ; Kazuki Akamatsu, Auteur ; Ryuji Miura, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4458-4462
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Thermodynamic properties Modeling Dynamic model Molecular dynamics method Free energy
Résumé :	Polyzwitterions (PZs), such as carboxybetaine and phosphobetaine polymers, show remarkable suppression of protein adsorption and have potentially widespread application as bioengineering materials. We show that free energy profiles, from molecular dynamics simulations in explicit water, for hydrophilic and hydrophobic amino acids approaching a PZ monomer, provide thermodynamic insights into protein adsorption. The predicted profiles for PZ have almost no energetically stable points, regardless of the type of residue. In contrast, the profiles for conventional polyester show some energetically remarkable minima, particularly for the hydrophobic residue. These results agree with recent experimental reports of differences in the amounts of protein adsorbed on these polymers, suggesting that free energy calculations for hydrophobic residue can play a sigitificant role in assessing antifouling properties. Our simple strategy, which investigates the affinities between residues and monomers, can become a convenient approach to predicting protein antifouling properties of polymeric materials.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25655655

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4452-4457

Titre :	Biosorption and recovery of chromium from industrial wastewaters by using saccharomyces cerevisiae in a flow - through system
Type de document :	texte imprimé
Auteurs :	Giovanni Colica, Auteur ; Pier Cesare Mecarozzi, Auteur ; Roberto De Philippis, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4452-4457
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Industrial waste water Biosorption
Résumé :	This study investigated the possibility to adsorb and recycle Cr(VI) from the wastewater of a Cr-electroplating process using Saccharomyces cerevisiae in a flow-through system at a pilot scale. In a first set of experiments, it was demonstrated that an HCl pretreatment of the biomass induced a 2-fold increase in the amount of Cr(VI) removed. In the following experiments, 30 L of wastewater was treated with HCl-pretreated yeast biomass confined in a filter press, obtaining an average specific metal removal of 13 mg per g of dry biomass. At the end of the bioremoval process, the biomass was incinerated and the ashes thus obtained were composed of >90% (w/w) chromium. The results obtained at pilot scale with chromium-containing wastewaters demonstrated the good metal sorption capability of the acid-pretreated S. cerevisiae biomass and the possibility to recover, at a high purity, the metal from the biomass at the end of the treatment process.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25655654

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4445-4451

Titre :	Effects of orifice angle and surface roughness on the bubbling - to - jetting regime transition in a bubble column
Type de document :	texte imprimé
Auteurs :	Carlos Irrgang, Auteur ; Olaf Hinrichsen, Auteur ; Raymond Lau, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4445-4451
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Bubble column Bubbling Roughness
Résumé :	Submerged gas injection into liquids is a widely applied processing technique. The main objective of the current study was to determine the effects of orifice angle and orifice surface roughness on the bubbling-to-jetting regime transition in a bubble column. The bubbling behaviors at single-orifice distributors were investigated over a wide range of orifice gas velocities. The pressure fluctuations in the plenum and high-speed image sequence of the bubble emerging process at the orifice were recorded in experiments. Both orifice angle and orifice surface roughness were found to have significant effects on the regime-transition velocity between the bubbling and jetting regimes. Models were also developed by incorporating those available in the literature with the experimental results obtained in the current study.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25655653

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4440–4444

Titre :	Utilization of waste newspaper using oyster mushroom mycelium
Type de document :	texte imprimé
Auteurs :	Leonard Kopinski, Auteur ; Sylwia Kwiatkowska-Marks, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4440–4444
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Mycelium
Résumé :	Research on the utilization of waste newspaper using a mycelium of the oyster mushroom Pleurotus ostreatus was conducted. The mycelium and fruiting bodies grown in growing substrates were cultured during the studies. The growing substrates were composed of waste newspaper or wheat straw, and mixtures thereof. Utilization of the components of the substrates was evaluated as the degree of utilization and performance of the fruiting bodies. The effectiveness of utilization depended on the amount of waste newspaper in the substrates. The maximum utilization was observed in the 3:1 mixture of waste newspaper and wheat straw. No fruiting bodies were formed in the substrate containing waste newspaper alone. The performance of the fruiting bodies was observed to increase as the concentration of waste newspaper in the substrates decreased. Heavy metals were present in the fruiting bodies grown in the substrates containing waste newspaper. Their concentrations were higher than acceptable by applicable standards, and the fruiting bodies were inedible. The substrates after cultivation were enriched in oyster protein.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202765b

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4433-4439

Titre :	Inert - gas - stripping method for measuring solubilities of sparingly soluble gases in liquids. solubilities of some gases in protic ionic liquid 1 - Butyl, 3 - hydrogen - imidazolium acetate
Type de document :	texte imprimé
Auteurs :	Waheed Afzal, Auteur ; Brian Yoo, Auteur ; John M. Prausnitz, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4433-4439
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Ionic liquid Solubility Stripping Inert gas
Résumé :	The inert-gas stripping method is useful for rapidly measuring solubilities of moderately and sparingly soluble gases in liquids. Earlier versions of this method can give only solubilities of volatile-liquid solutes in low-volatile solvents. However, the modifications presented here enable measurement of very low solubilities of gases in liquids. Henry's constants are reported for carbon dioxide, krypton, oxygen, air, and nitrogen in n-dodecane and n-pentadecane, and for carbon dioxide in ethylene glycol at near-ambient conditions. The new Henry's constants compare well with those in the literature. Henry's constants are reported for carbon dioxide, ethane, ethylene, krypton, oxygen, air, and nitrogen at near-ambient conditions in the protic ionic liquid 1-butyl, 3-hydrogen-imidazolium acetate; we select this protic ionic liquid because, relative to other ionic liquids, it has low viscosity and because solubility data in protic ionic liquids are rare.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25655651

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4424-4432

Titre :	Numerical simulation of gas production from natural gas hydrate using a single horizontal well by depressurization in qilian mountain permafrost
Type de document :	texte imprimé
Auteurs :	Xiao-Sen Li, Auteur ; Bo Yang, Auteur ; Gang Li, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4424-4432
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Mountain Depressurization Gas hydrates Natural gas Production Numerical simulation
Résumé :	In November 2008, gas hydrate samples were recovered during the scientific expedition conducted in the Qilian Mountain Permafrost It is expected that this area will become a strategic area of gas hydrate production in China. However, the evaluation of the hydrate deposits in the area as a potential energy resource has not been completed. Using numerical simulation and currently available data from site measurements, we preliminarily estimate the gas production potential of these hydrate reservoirs. The cumulative volume of the produced CH4 at the well in the early production period (0―10 years) is more than 50% of the total gas production from the well. The gas hydrate dissociation mainly occurs in the vicinity of the horizontal well and along a cylindrical interface. There is a ringlike structure of ice around the horizontal well during the gas production process. With the decrease of the gas production rate, the ice starts to melt from the bottom to the top under the influence of the geothermal gradient The sensitivity analysis demonstrates the dependence of production on the intrinsic permeability and the initial deposit temperature. Economic assessment based on the cumulative volumetric gas production and the gas-to-water ratio indicates that it is not economically viable to produce gas from this hydrate deposit using single horizontal well by depressurization.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25655650

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4414-4423

Titre :	Experimental characterization and modeling of high performance structured packings
Type de document :	texte imprimé
Auteurs :	Zarko Olujic, Auteur ; Thomas Rietfort, Auteur ; Helmut Jansen, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4414-4423
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Ordered packing Modeling
Résumé :	Results are presented of the total reflux distillation experiments carried out with the newest generation of J. Montz corrugated sheet structured packings, including metal sheet packings (B1-250MN, B1-350MN, B1-500MN), expanded metal packings (BS-500MN), and wire gauze packings (A3-500M), using a 0.59 m i.d. column and chlorobenzene/ethylbenzene as a test system. It appears that by combining appropriately the dimensions and design of corrugations and the corrugation inclination angle, either efficiency or capacity, or occasionally even both, can be enhanced significantly, depending on the type of the packing. This allows leaner columns in new designs and more capacity and other benefits in retrofit situations. The Delft model, with appropriate enhancement of the turbulent vapor flow mass transfer coefficient and the flow direction change related pressure drop, proved to be capable of approaching closely measured efficiency and pressure drop both qualitatively and quantitatively. The exception in this respect is the pressure drop of B1-500MN, with a significant underprediction that is more pronounced at 1 bar than at 0.1 bar, while the trend as well as the predicted points of onset of loading are close to observed ones.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25655649

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4407–4413

Titre :	Study on sorption behaviors of H2S by triethanolamine - modified mesoporous molecular sieve SBA - 15
Type de document :	texte imprimé
Auteurs :	Xiaozhong Chu, Auteur ; Zhipeng Cheng, Auteur ; Yijiang Zhao, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4407–4413
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Sorption process simulation
Résumé :	A key technology for natural gas vehicles is the removal of H2S trace content from fuel. In previous studies, purification based on the adsorption principle has been proved to have low separation cost, and the selection of an adsorbent is a crucial factor in this method. To enhance H2S sorption capacity, an ordered SBA-15 silica mesoporous material with a high specific surface area is synthesized as a carrier of triethanolamine (TEA). The mesoporous molecular sieve SBA-15 coated with a TEA film considerably enhances H2S sorption capacity. The effects of operational variables on H2S removal efficiency, including the amount of TEA-loading, adsorption pressure, flow rate, and fixed bed length, are investigated with a single-column adsorption apparatus. A model demonstrating H2S dynamic sorption processes through as TEA-modified adsorbent bed is proposed. The model fits well the experimental data and can be applied to the H2S sorption process simulation and optimal process design.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202360h

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4397–4406

Titre :	Adsorption of Cd(II), Ni(II), and Zn(II) by tourmaline at acidic conditions : Kinetics, thermodynamics, and mechanisms
Type de document :	texte imprimé
Auteurs :	Cuiping Wang, Auteur ; Jingting Liu, Auteur ; Zhiyuan Zhang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4397–4406
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Adsorption Kinetics Thermodynamics
Résumé :	Batch experiments investigated the effects of time, temperature, and initial concentration of metal ions on heavy metal removal by tourmaline under acidic conditions to evaluate the kinetics, thermodynamics, and mechanisms. The results indicated that the adsorption of Cd(II), Zn(II), and Ni(II) depended significantly on all the above-mentioned parameters. The adsorption kinetics closely followed the pseudo-second-order model. The Langmuir, Freundlich, Temkin, and Dubinin–Radushkevich models well described the equilibrium isotherm at acidic conditions. The maximum adsorption capacity (qm) of tourmaline for Cd(II), Zn(II), and Ni(II), as calculated from Langmuir isotherms at an initial pH 4.0, was greater than that obtained for previously reported materials, and followed in the order Cd(II) > Zn(II) > Ni(II) under different temperature conditions. Thermodynamic parameters indicated that adsorption was feasible, spontaneous, and endothermic, and suggested that both physisorption and chemisorption were involved. Furthermore, the pH variation after adsorption, metal ions desorbed and released, ζ-potential, and FT-IR analysis indicated that the physisorption and chemisorption mechanisms of tourmaline for heavy metals included water automatically polarized by tourmaline, the ion exchange process, and electropolar adsorption, Among the mechanisms, the automatic polarization of water caused by tourmaline is a unique adsorption mechanism of tourmaline.
ISSN :	0888-588
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie2023096

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4388–4396

Titre :	Preparation of polyvinylidene fluoride (PVDF) membranes via nonsolvent induced phase Separation Process using a Tween 80 and H2O Mixture As an Additive
Type de document :	texte imprimé
Auteurs :	Ping-Yun Zhang, Auteur ; Hu Yang, Auteur ; Zhen-Liang Xu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4388–4396
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Separation process
Résumé :	Polyvinylidene fluoride (PVDF) membranes were fabricated by the nonsolvent induced phase separation (NIPS) process using Tween 80 and H2O as a mixture additive from both 60 °C and room-temperature (RT) casting solution. Resultant PVDF membranes revealed improved pure water flux (PWF), enlarged mechanical properties, and well Bovine serum albumin (BSA) and Dextran rejection as a result of addition of water into the PVDF–DMAc–Tween 80 system. The improved performance was attributed to the existence of nonsolvent, which was solubilized by polar head groups of Tween 80 reverse micelle to form the water pool. Further, the interaction between polar head of surfactant and water provided a balance resistance to the interconnection between PVDF and hydrophobic chains of surfactant, which enhanced the thermodynamics stability of casting solution. During demixing process, water diffusion from the interior of casting solution, increased the precipitation rate and led to the insufficient crystallization process of polymer. Finally, the Tween 80 reverse micelle confined the movement of water in solution, making the fingerlike structure slim and confined, with the wall structure between macrovoids.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201806v

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4380–4387

Titre :	Magnetic polyacrylic anion exchange resin : Preparation, characterization and adsorption behavior of humic acid
Type de document :	texte imprimé
Auteurs :	Chendong Shuang, Auteur ; Fei Pan, Auteur ; Qing Zhou, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4380–4387
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Organic matter Adsorption Preparation Anionic resin
Résumé :	Magnetic polyacrylic resin (R0) was prepared by suspension polymerization in the presence of γ-Fe2O3 and γ-methacryloxypropyltrimethoxysilane (γ-MPS). The obtained magnetic resin (R0) was modified sequentially by ammonolysis and alkylation to produce a magnetic weakly basic anion exchange resin (R1) and a magnetic strongly basic anion exchange resin (R2). Infrared (IR) spectra, elemental analysis, scanning electron microscopy (SEM), magnetization, Brunauer–Emmett–Teller (BET) surface area and chemical analysis were all determined to characterize these resins. The investigation of humic acid (HA) adsorption on R0, R1, and R2 showed that chemical interactions between the functional groups of the resin and HA were responsible for HA adsorption. The adsorption capacity of HA on R1 was 20%–60% less than that of R2, but the R1 resin was easier to regenerate with NaOH aqueous solution. A mixture of 1% NaCl and 1% NaOH was found to be highly efficient for the regeneration of both R1 and R2 resins, with desorption efficiencies measuring >90%. Pseudo-second-order model and Freundlich equation fit better for HA adsorption onto R1 and R2 than other typical kinetic and thermodynamic models, respectively. The effects of pH, coexisting salts (i.e., NaCl and Na2SO4), and recyclability were also assessed.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25655645

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4371–4379

Titre :	A novel method for assessing the effect of pressure on vapor – liquid equilibrium in ternary systems
Type de document :	texte imprimé
Auteurs :	Daniel A. Beneke, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4371–4379
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Vapor liquid equilibrium
Résumé :	In distillative separations, operating pressure is an important parameter influencing not only the cost of a given separation, but potentially its feasibility too. A reliable technique for assessing the effect of pressure on vapor–liquid equilibrium is thus imperative for robust distillation design. This paper presents a method that is not only reliable, but also allows a designer to creatively synthesize a column by finding areas where the phase equilibrium may be beneficial for a particular separation. By viewing global residue curve maps which incorporate theoretical negative compositions, pressure effects are easily traceable. It is shown how the NRTL model in particular is a very useful thermodynamic model for this unique assessment of pressure effects. Using this technique, significant insights are gained into the appearance and disappearance of azeotropes at certain pressures. Moreover, this paper presents a novel eigenvalue method which allows one to determine exact critical pressures where residue curve map topology is transformed.
ISSN :	0888-58
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202899a

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4363–4370

Titre :	Optimization of a carbon dioxide - assisted nanoparticle deposition process using sequential experimental design with adaptive design space
Type de document :	texte imprimé
Auteurs :	Michael J. Casciato, Auteur ; Sungil Kim, Auteur ; J. C. Lu, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4363–4370
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Optimization Carbon Dioxide
Résumé :	A sequential design of experiments methodology with an adaptive design space is proposed and implemented to optimize a nanofabrication technique that possesses significant uncertainty in terms of design region and model structure along with an engineering tolerance requirement. This method is termed Layers of Experiment (LoE) with Adaptive Combined Design (ACD) and is developed specifically for advanced technology processes where there is little or no foreknowledge of the design region and/or model structure from either mechanistic understanding or empirical studies. This technique was applied to optimize an elevated pressure, elevated temperature carbon dioxide (epet-CO2) nanoparticle deposition process where silver nanoparticles were deposited directly from an organometallic precursor in the fluid phase onto a silicon wafer surface. A target mean nanoparticle size of 40 nm was chosen, with surface enhanced Raman spectroscopy (SERS) as the motivating application. Using the LoE/ACD method, it was possible to find the process optimum for the epet-CO2 process and build a reliable model using only 12 experiments conducted in two sequential layers. With temperature as the design variable, the first layer of experiments was conducted in the region [60 °C, 150 °C], while the second layer was conducted in the region [98 °C, 128 °C], indicating that the LoE/ACD algorithm reduced the size of the design region by 60 °C while building a reliable model for statistical inference. In the first layer, a purely space-filling design was used since the model structure was unknown; in the second layer, the ACD approach yielded a design weighted between space-filling and D-optimal, favoring the D-optimal design. The optimized temperature for fabricating 40 nm diameter silver nanoparticles in this system was 117 °C.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie2028574#cor1

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4347–4362

Titre :	Operational planning of large - scale continuous processes : Deterministic planning model and robust optimization for demand amount and due date uncertainty
Type de document :	texte imprimé
Auteurs :	Jie Li, Auteur ; Peter M. Verderame, Auteur ; Christodoulos A. Floudas, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4347–4362
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Uncertainty Optimization Modeling Continuous process Planning
Résumé :	The operational planning problem typically determines both the plant’s aggregate and daily production targets to meet product demands over a long time horizon varying from one to three months. The daily production profile generated from the operational planning level is used to schedule the day-to-day operations of the plant. In this paper, we first extend the production disaggregation model framework proposed by Verderame and Floudas, Ind. Eng. Chem. Res.2008, 47, 4845–4860 to develop a novel mixed-integer linear programming operational planning model based on discrete-time representation for a large-scale multiproduct continuous plant. We allow unused processing time to carry over from one day to the next and thus capture the continuous time nature of the plant. The production totals are disaggregated into a feasible distribution of daily production requirements, and daily production profiles are provided to meet the requirements of the medium-term scheduling model developed by Shaik and Floudas, Comput. Chem. Eng.2009, 33, 670–686. Then, we extend the work of Lin et al. Ind. Eng. Chem. Res.2004, 28, 1069–1085 and Janak et al. Ind. Eng. Chem. Res.2007, 31, 171–195 to address various forms of demand amount and due date uncertainty. The computational results show that the proposed deterministic and robust planning models successfully provide tight upper bounds on the plant’s true production capacity.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25655642

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4328–4346

Titre :	Model building methodology for multiphase reaction systems — modeling of CO2 absorption in monoethanolamine for laminar jet absorbers and packing beds
Type de document :	texte imprimé
Auteurs :	Rameshwar Hiwale, Auteur ; Sungwon Hwang, Auteur ; Robin Smith, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4328–4346
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Chemical reactions Absorption processes
Résumé :	This research has focused on a new methodology to develop a rigorous reactor model for gas–liquid chemical reactions in absorption processes. This involves simultaneous chemical reaction and mass transfer between two phases. In particular, all feasible chemical reaction mechanisms and kinetics are considered for the modeling to improve the accuracy of the simulation results. Detailed mathematical modeling is developed to identify physical properties of the key components. For a reactor design, a packed bed reactor has been developed with two different types of modeling approaches. The results of two separate models are compared with the laboratory experimental data. For a case study, CO2 absorption to monoethanolamine (MEA) solution is used based on a wide range of experimental data from both laminar jet absorber and packed bed column.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201869w

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4313–4327

Titre :	Just - in - time kernel learning with adaptive parameter selection for soft sensor modeling of batch processes
Type de document :	texte imprimé
Auteurs :	Yi Liu, Auteur ; Zengliang Gao, Auteur ; Ping Li, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4313–4327
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Batch processes
Résumé :	An efficient nonlinear just-in-time learning (JITL) soft sensor method for online modeling of batch processes with uneven operating durations is proposed. A recursive least-squares support vector regression (RLSSVR) approach is combined with the JITL manner to model the nonlinearity of batch processes. The similarity between the query sample and the most relevant samples, including the weight of similarity and the size of the relevant set, can be chosen using a presented cumulative similarity factor. Then, the kernel parameters of the developed JITL-RLSSVR model structure can be determined adaptively using an efficient cross-validation strategy with low computational load. The soft sensor implement algorithm for batch processes is also developed. Both the batch-to-batch similarity and variation characteristics are taken into consideration to make the modeling procedure more practical. The superiority of the proposed soft sensor approach is demonstrated by predicting the concentrations of the active biomass and recombinant protein in the streptokinase fed-batch fermentation process, compared with other existing JITL-based and global soft sensors.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201650u

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4299-4312

Titre :	Synthesis of interplant water - allocation and heat - exchange networks. Part 1 : Fixed flow rate processes
Type de document :	texte imprimé
Auteurs :	Rui-Jie Zhou, Auteur ; Li-Juan Li, Auteur ; Hong-Guang Dong, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4299-4312
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Water networks Heat exchange
Résumé :	This paper is part 1 of a series dealing with the design of integated interplant water-allocation and heat-exchange networks (IWAHENs), a special case of interplant network synthesis with multiple physical properties. Traditionally, the tasks of optimizing water-allocation networks (WANs) and heat exchange networks (HENs) were either performed individually or studied within a single plant. In this paper, a novel multiscale state—space superstructure is developed to capture all possible network configurations for the fixed flow rate (FF) IWAHEN designs with both direct and indirect integration schemes. In addition, our model has been simplified to deal with the interplant HEN design where the optimal utility network can be determined simultaneously. By properly addressing the interactions between different plants as well as the WAN and HEN subsystems, lower total annualized cost (TAC) can be obtained in all examples by solving the corresponding mixed-integer nonlinear programming (MINLP) model.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie2014789

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4288-4298

Titre :	Minimum variance benchmark for performance assessment of decentralized controllers
Type de document :	texte imprimé
Auteurs :	Antonius Yudi Sendjaja, Auteur ; Vinay Kariwala, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4288-4298
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Benchmarks
Résumé :	The available minimum variance (MV) benchmarks do not take the controller structure into account and thus can lead to incorrect conclusions regarding the performance of decentralized controllers. In this paper, we present a method for computing a lower bound on the least output variance achievable using decentralized controllers, where the nonconvexity of the optimization problem is handled using sums of squares programming. Though tight, the computation of this lower bound requires that the process model be known. As a more practical approach, we derive an MV benchmark for performance assessment of decentralized controllers on a loop by loop basis. The MV benchmark for loop by loop analysis can be estimated from the closed loop operating data with the knowledge of time delays between all the inputs and outputs. The usefulness of the proposed benchmarks is demonstrated using simulation examples.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25655638

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4279-4287

Titre :	Optimization of the petroleum product supply chain under uncertainty : A case study in northern brazil
Type de document :	texte imprimé
Auteurs :	Fabrício Oliveira, Auteur ; Silvio Hamacher, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4279-4287
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Uncertainty Petroleum product Optimization
Résumé :	This Article addresses the problem of optimizing the investment planning process of a logistics infrastructure for the distribution of petroleum products under uncertainty. For this purpose, a two-stage stochastic model was developed. Because of the large number of possible scenarios for the future realization of demands, the Sample Average Approximation (SAA) methodology was used to produce approximations of the optimal solution. The proposed model and solution methodology were applied to a real case study on the distribution of petroleum products in northern Brazil. The results show that the methodology allows us to obtain solutions that are relatively close to the real optimal solution of the problem with optimality gaps estimated at up to 1%, which are reasonable for most practical purposes.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25655637

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4267–4278

Titre :	Design and Fluid Dynamic Analysis of a Three-Fluidized-Bed Reactor System for Chemical-Looping Hydrogen Generation
Type de document :	texte imprimé
Auteurs :	Zhipeng Xue, Auteur ; Shiyi Chen, Auteur ; Dong Wang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4267–4278
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Fluid dynamic Hydrogen
Résumé :	Chemical-looping hydrogen generation (CLHG) can produce hydrogen from fossils fuels with inherent separation of CO2. Iron oxide is a suitable oxygen carrier for this process. The CLHG process basically involves three reactors, a fuel reactor (FR), a steam reactor (SR), and an air reactor (AR). In the FR, the carbon-containing fuel gases react with hematite (Fe2O3). The product solids are wüstite (FeO), and the product stream is a mixture of carbon dioxide and water vapor. After water condensation, pure carbon dioxide can be obtained. FeO then enters the SR and react with steam, giving the gas product hydrogen and the solid product magnetite (Fe3O4). In the AR, Fe3O4 is reoxidized to Fe2O3. Through this cycle, hydrogen is generated with inherent separation of CO2. In this article, a novel compact fluidized-bed fuel reactor is proposed. It integrates a bubbling fluidized bed and a riser to obtain full conversion of unreacted fuel gases through the thermodynamic equilibrium limit. Based on this fuel reactor, a cold-flow model of the three-fluidized-bed reactor system with a 50-kW CLHG design scheme was built to test the feasibility of this CLHG process. A series of tests with respect to solids circulation rate, gas leakage, and stability of long-term operation were performed by varying the inlet gas flow and total solids inventory. The results showed that the three-fluidized-bed reactor system can run steadily. The solids circulation rate could be changed in a wide range by adjusting the inlet gas flows. The gas leakage was associated with both the solids circulation rate and the pressure difference balanced by the downcomer. The system showed a stable pressure difference and solids circulation rate during a test of long-term operation.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201052r?mi=tei08o&af=R&pageSize=20&searchT [...]

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4254–4266

Titre :	Prediction of profiles in the process industries
Type de document :	texte imprimé
Auteurs :	Marco S. Reis, Auteur ; Pedro M. Saraiva, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4254–4266
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Prediction Process industries
Résumé :	The characterization of products and processes by space- or time-related sets of measurements (profiles) is becoming an increasingly common situation in today’s highly instrumentalized manufacturing systems. Even though many applications and methodologies in which profile measurements are employed as inputs to analysis tasks have already been proposed and described, problems in which they naturally appear as outputs are rare. Therefore, in this work, we present real-world applications in which profiles are the desired prediction targets and describe the methodologies followed to address the underlying analysis goals. In this context, we show how to properly establish the sample-specific prediction intervals for profiles, in a simple and flexible way, through nonparametric resampling or noise addition procedures. The added value of the various analyses carried out during the description of the case studies is also highlighted from the standpoint of the associated benefits for process improvement.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300390h

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4247-4253

Titre :	TiO2 - coated ultrathin SnO2 nanosheets used as photoanodes for dye - sensitized solar cells with high efficiency
Type de document :	texte imprimé
Auteurs :	Jun Xing, Auteur ; Wen Qi Fang, Auteur ; Zhen Li, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4247-4253
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Dyes Titanium oxide
Résumé :	Ultrathin SnO2 nanosheets were prepared by a hydrothermal method using SnF2 and methenamine as precursor and morphology controlling agent, respectively. Structural characterizations indicate that these ultrathin SnO2 nanosheets having a thickness of approximately 4—6 nm can assemble into a three-dimensional, flowerlike architecture. Due to the higher electron mobility and enhanced light-scattering effect of these hierarchical structures, the dye-sensitizud solar cells (DSSCs) based on such SnO2 architectures exhibit much higher cell performance than that of SnO2 nanoparticles. Furthermore, coating a TiO2 layer on these ultrathin SnO2 nanosheets can also significantly improve the short-circuit current, open-circuit voltage, and fill factor. Compared with the plain SnO2 nanosheets, the TiO2 coating on these ultrathin SnO2 nanosheets can lead to more than 7 times improvement in the energy conversion efficiency. With a thin layer of TiO2 coating, the highest overall photoconversion efficiency of DSSCs based on SnO2 nanosheets is approximately 2.82%, which is over 2 times higher than that of DSSCs constructed by conversional SnO2 nanoparticles.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25655634

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012)

Titre :	TiO2 - coated ultrathin SnO2 nanosheets used as photoanodes for dye - sensitized solar cells with high efficiency
Type de document :	texte imprimé
Année de publication :	2012
Langues :	Anglais (eng)

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4240–4246

Titre :	Increasing the use of high - yield pulp in coated high - quality wood - free papers : From laboratory demonstration to mill trials
Type de document :	texte imprimé
Auteurs :	Hongbin Liu, Auteur ; Yunzhi Chen, Auteur ; Hongjie Zhang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4240–4246
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Pulp Coated high quality
Résumé :	Although high-yield pulps (HYP) are gaining increasing use to replace hardwood kraft pulp in paper grades such as uncoated and coated fine papers, the amount has been typically limited to less than 20% because there are concerns about its potential impact on papermaking operation and product quality. To address these concerns, laboratory experiments that mimic the actual paper machine operation were carried out and coated paper samples from mill trials were examined to clarify the impact of high-level HYP substitution on the properties of coated wood-free papers. Results showed that the HYP substitution, even at 40%, did not yield negative effects on strength properties such as tensile and tear; in fact the Scott bond increased with the HYP addition. The small increase in the surface roughness from the HYP addition can be eliminated by the filler addition, precalendering, and coating process. The lower brightness and CIE (Commission Internationale d'Eclairage) whiteness of the HYP can be compensated for by the addition of optical brightening agents (OBAs) and dyes, as well as pigments in the coating color. The analysis of samples collected from mill trials indicated that coated paper containing 40% HYP has lower coating penetration than that containing 40% HYP content paper samples. This was attributed to the smaller pore size created by HYP substitution. No significant differences were found between the samples containing 17 and 40% HYP on print gloss, color gamut, and print gloss uniformity. The implication from this study is that the HYP substitution level can be increased up to 40% in the production of coated wood-free paper without significant negative effect on the paper quality.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie2029514

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4230–4239

Titre :	Development of an instantaneous corrosion rate monitoring system for metal and metal alloys in recirculating cooling systems
Type de document :	texte imprimé
Auteurs :	Mahbuboor R. Choudhury, Auteur ; Ming-Kai Hsieh, Auteur ; Radisav D. Vidic, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4230–4239
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Corrosion Metal alloys Aqueous system
Résumé :	An instantaneous corrosion rate (ICR) monitoring technique, suitable for application in recirculating cooling water systems, is useful for rapid appraisal of corrosiveness of the aqueous system with respect to metal and metal alloys of interest. In this study the instantaneous corrosion rates of mild steel, copper, and cupronickel alloys were measured at various times during an exposure period by electrochemical polarization resistance measurements using a three-electrode system. The average corrosion rates (ACR) were also determined by the gravimetric weight loss method to correlate with the ICR data. Stainless steel was used as the reference electrode to replace the standard saturated calomel electrode for increased robustness of the system in pilot-scale cooling systems. A side-streamflow channel unit was designed to hold the three electrodes in flowing cooling water. Use of stainless steel as a reference electrode was reliable and ICR was monitored intermittently for 28 days. Integration of the ICR data from the pilot-scale cooling towers correlated well with the ACR results, with similar correlation coefficients obtained from bench-scale experiments.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202845g

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4222-4229

Titre :	Enhancing the stability of oil - in - water emulsions emulsified by coconut milk protein with the application of acoustic cavitation
Type de document :	texte imprimé
Auteurs :	Virangkumar N. Lad, Auteur ; Zagabathuni Venkata Panchakshari Murthy, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4222-4229
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Acoustic cavitation Emulsion Stability
Résumé :	Coconut milk protein (CMP) is a naturally derived protein recovered from the kernel of fresh coconut (Cocos nucifera L.) having a high nutrient value. With increasing demand of naturally available efficient emulsifiers and stabilizers for the production of food and health care emulsions with reasonable stability, many emulsifiers are being utilized for the commecial production of many products. Even though the CMP is reported as a poor emulsifier, we prepared very stable emulsions with CMP using sonication. The effects of ultrasound (250 W, 20 kHz and 120 W, 20 kHz) on the stability of sunflower oil in-water emulsions made by CMP are studied. It is found that though the acoustic energy is responsible for further reduction of droplet size for CMP emulsions, energetic cavitations and high pressure shock waves, generated due to the collapsing bubble, are responsible for droplet breakup. The size of the dispersed droplets, in the case of sonication using an ultrasonic horn with all the concentrations of CMP, was smaller than that created using an ultrasonic bath. Emulsions sonicated by the ultrasonic horn were found to be very stable with variation of salt concentration.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25655631

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4215–4221

Titre :	Control of surface defects and agglomeration mechanism of layered double hydroxide nanoparticles
Type de document :	texte imprimé
Auteurs :	Yongshan Zhou, Auteur ; Xiaoming Sun, Auteur ; Kai Zhong, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4215–4221
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Hydroxide Nanoparticles
Résumé :	Agglomeration is a common problem in the production and application of nanoparticles. The degree of agglomeration of layered double hydroxide (LDH) nanoparticles is difficult to control in its industrial production. The properties of industrial scale MgAl–CO3–LDH products obtained using an aging reactor composed of a 1 m3 kettle with a water cooling jacket have been compared with MgAl–CO3–LDHs prepared using different aging times in a model laboratory scale reactor [a 500 mL flask]. The effect of varying aging times on the agglomeration of the LDH nanoparticles has been studied experimentally. The crystallinity, surface defects, and surface zeta potential of the LDHs have been studied in an effort to understand the mechanism of agglomeration of the nanoparticles. The results show that in poorly crystalline LDHs, accumulation of Al3+ cations at different points in the layers results in an increase in local charge density. Consequently, the zeta potential and the electrostatic repulsion between particles decrease, resulting in serious agglomeration of LDH nanoparticles. In contrast, for LDHs with higher crystallinity produced with extended aging times, the layer cations become uniformly distributed resulting in an increase in zeta potential and increased electrostatic repulsion between the particles. As a result, the degree of agglomeration is reduced.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202302n

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4208–4214

Titre :	Replacement / Etching route to ZnSe nanotube arrays and their enhanced photocatalytic activities
Type de document :	texte imprimé
Auteurs :	Lingling Chen, Auteur ; Weixin Zhang, Auteur ; Cheng Feng, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4208–4214
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Nanotube Photocatalytic
Résumé :	Well-aligned ZnSe nanotube arrays with diameters of 300–400 nm and wall thicknesses of 60–70 nm have been controllably prepared based on a replacement/etching method, with ZnO nanorod arrays on zinc substrate as sacrificial templates. An obvious difference of the solubility product (Ksp) between the ZnSe wall and ZnO core materials is crucial for the direct replacement of one type of anions by the other. Ammonia as the chemical etching agent is also important for dissolving ZnO nanorod core. The photocatalytic activities of the as-prepared ZnSe nanotube arrays have been studied for the degradation of methyl orange aqueous solution and compared with those of ZnO nanorod arrays and the intermediates including ZnO/ZnSe core/sheath nanorod arrays and partially dissolved ZnO core/ZnSe sheath nanorod arrays, respectively. The results indicate that ZnSe nanotube arrays exhibit superior photocatalytic performance to the other three nanostructured arrays, which can be mainly attributed to their full hollow interior nanotubes providing more accessibility to the dye molecules and more reactive adsorption/desorption sites for photocatalytic reactions. Furthermore, the ZnSe nanotube arrays have successfully overcome the shortcomings related to photocatalyst recovery and stability, which the powder-form photocatalysts usually face. ZnSe nanotube arrays as photocatalysts are expected to be promising in sewage water treatment.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202044v

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4199–4207

Titre :	Optimization and modeling of photocatalytic degradation of Azo dye using a response surface methodology (RSM) based on the central composite design with immobilized titania nanoparticles
Type de document :	texte imprimé
Auteurs :	Mohammad Vaez, Auteur ; Abdolsamad Zarringhalam Moghaddam, Auteur ; Somayeh Alijani, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4199–4207
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Nanoparticle Design Composite material Azo dye Photochemical degradation Modeling Optimization
Résumé :	The experimental design methodology was used to model and optimize the operational parameters of the photocatalytic degradation of Acid Red 73 using immobilized TiO2 nanoparticles. Four experimental parameters were chosen as independent variables: pH, initial dye concentration, H2O2 concentration, and anion concentration. A multivariate experimental design was used to establish a quadratic model as a functional relationship between the efficiency of Acid Red 73 degradation (response) and four independent variables. The degradation efficiency was significantly affected by the initial dye concentration and the pH. The optimal values of the parameters were found to be a pH of 3, an initial dye concentration of 25 mg/L, an H2O2 concentration of 0.5 mg/L, and an anion concentration of 0.69 mg/L. The degradation efficiency approached 92.24% under optimal conditions. Regression analysis with an R2 value of 0.9785 indicated a satisfactory correlation between the experimental data and predicted values.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25655628

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4192–4198

Titre :	Kinetics and mechanism of sulfite oxidation in the magnesium - based wet flue gas desulfurization process
Type de document :	texte imprimé
Auteurs :	Zhigang Shen, Auteur ; Shaopeng Guo, Auteur ; Wanzhong Kang, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4192–4198
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Kinetics Oxidation Gas desulfurization
Résumé :	The kinetics of sulfite oxidation in the magnesium-based wet flue gas desulfurization (FGD) process were investigated in a stirred bubbling reactor by varying the concentrations of MgSO3 and MgSO4, pH, air flow and temperature. The reaction was found to be 0.88 order with respect to magnesium sulfite and the oxidation could reach the maximum rate when the pH value was close to 6.5. The mechanism of the oxidation was discussed, and it was concluded that the oxidation is controlled by diffusion of oxygen. These results would be useful for the design or process optimization of the magnesium-based wet FGD system.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie300163v

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4181–4191

Titre :	Photo - fenton degradation of the herbicide 2,4 - dichlorophenoxyacetic acid in laboratory and solar pilot - plant reactors
Type de document :	texte imprimé
Auteurs :	Leandro O. Conte, Auteur ; Jorgelina Farias, Auteur ; Enrique D. Albizzati, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4181–4191
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Solar reactor Photo fenton degradation
Résumé :	A theoretical and experimental study of a pilot-plant solar reactor for the photo-Fenton degradation of the herbicide 2,4-dichlorophenoxyacetic acid (2,4-D) in aqueous solution is presented. Initially, a kinetic model is proposed to obtain the reaction rates of 2,4-D, the main intermediate (2,4-dichlorophenol), and the hydrogen peroxide. The kinetic study was performed in a well-stirred tank laboratory reactor. The effects of ferric salt initial concentrations, hydrogen peroxide to 2,4-D initial concentration ratios, reaction temperatures, and radiation levels are studied. The proposed kinetic model and the experimental data are used to estimate the kinetic parameters, applying a nonlinear regression procedure. Afterward, the kinetic model is used to predict the reactant concentrations during the photo-Fenton degradation in a pilot-plant solar reactor designed to capture the UV/visible/IR solar radiation. The solar reactor was able to reach a complete degradation of the 2,4-D and 2,4-dichlorophenol after 60 min, and a total organic carbon conversion of 98.9% after 210 min.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie2023228

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4173–4180

Titre :	Role of phosphate species and speciation kinetics in detergency solutions
Type de document :	texte imprimé
Auteurs :	Giulio Isacco Lampronti, Auteur ; Gilberto Artioli, Auteur ; Liliana Oliva, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4173–4180
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Kinetics Detergency solutions
Résumé :	The present investigation addresses the mechanisms of inorganic phases precipitation from detergency solutions of low polyphosphate formulation. In washing machine systems the main precipitation agent is Na4P2O7·10H2O that constitutes up to 10 wt % commercial Na5P3O10·5H2O. The solid incrustation on the heating coil is mainly formed by amorphous calcium pyrophosphate, subsequently transforming first into amorphous calcium orthophosphate and then into low crystallinity hydroxylapatite. The tripolyphosphate eventually present in the precipitates hydrolyzes as well at the working temperature present at the surface of the washing machine coil (100 °C). The pyrophosphate presence strongly inhibits the crystallization of hydroxylapatite in the washing system; thus, thermal treatment of amorphous calcium–pyrophosphate is a viable mechanism to produce hydroxylapatite with controlled crystallinity. A range of analytical techniques including X-ray diffraction, IR spectroscopy, and liquid- and solid-state NMR were employed to quantify the speciation kinetics in solution, to characterize the nature of the precipitates, and to monitor the phase transformations in the solid.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202130y

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4161-4172

Titre :	Catalytic conversion of syngas into higher alcohols over carbide catalysts
Type de document :	texte imprimé
Auteurs :	Jakob M. Christensen, Auteur ; Linus D. L. Duchstein, Auteur ; Jakob B. Wagner, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4161-4172
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Catalyst Synthesis gas Catalytic conversion
Résumé :	This work investigates the use of the bulk carbides Mo2C, WC, and NbC as catalysts for the conversion of syngas into higher alcohols. K2CO3/WC produces mainly CH3OH and CH4 with a low activity. NbC has a very low activity in CO hydrogenation. K2CO3/Mo2C produces mixed alcohols with a reasonable activity and selectivity. In a 94 h test the activity and the specific surface area of the K2CO3/Mo2C catalyst decreased significantly, but X-ray diffraction and transmission electron microscopy did not indicate a strong sintering of the carbide. A likely cause for the deactivation is the formation of carbonaceous deposits on the catalyst. At the same general activity level Li, K, and Cs provide similar promotional effects for Mo2C, although K at a loading level of alkali metal/Mo = 0.164 mol/mol provides the better behavior at equal conditions. The effect of further additives on the K2CO3/Mo2C system was evaluated, but only Cu yielded an improvement.
ISSN :	0888-5885
En ligne :	http://cat.inist.fr/?aModele=afficheN&cpsidt=25655624

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4152–4160

Titre :	Comprehensive study on wastewater treatment using photo - impinging streams reactor : Residence time distribution and reactor modeling
Type de document :	texte imprimé
Auteurs :	Sayed Javid Royaee, Auteur ; Morteza Sohrabi, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4152–4160
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Wastewater treatment Streams reactor
Résumé :	A photo impinging streams reactor was employed to study the degradation of phenol in aqueous solutions applying titanium dioxide nanoparticles as the reaction catalyst. The central composite experimental design method was applied to determine the pertinent operating parameters of such a process. These were phenol concentration, catalyst loading, pH of the slurry, and the feed flow rate. Residence time distribution (RTD) of the slurry phase within the reactor was measured using the impulse tracer method. A compartment model consisting of a number of mixed and plug flow regions was assigned to describe the flow pattern in the reactor. On the basis of such an arrangement and applying the Markov chains discrete time formulation, a three parameters model was derived for the RTD. The parameters of the theoretical RTD model were evaluated by comparing the latter with those determined experimentally. The RTD expression was applied in conjunction with the phenol degradation kinetic model to predict the apparent rate coefficient for such a reaction. The higher values observed for the apparent rate coefficient in impinging streams reactor than those available in the literature may be explained by the mass transfer limitations affecting the conventional reactors performance.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie201384s

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4143–4151

Titre :	Ethanol steam reforming thermally coupled with fuel combustion in a parallel plate reactor
Type de document :	texte imprimé
Auteurs :	Eduardo Lopez, Auteur ; Vanessa Gepert, Auteur ; Achim Gritsch, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4143–4151
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Ethanol Thermally coupled Combustion
Résumé :	This contribution reports experimental studies of ethanol steam reforming for the production of a hydrogen-rich reformate for fuel cells. A Pd-based catalyst, coated on corrugated metallic structures, was used. Axial concentration profiles for all components present in the system were measured in a kinetic reactor under isothermal conditions for different temperatures, flow rates, and steam-to-carbon ratios. Appropriate activity and hydrogen selectivity were achieved for this catalytic system at 650 °C, with complete ethanol conversion (no acetaldehyde), ca. 5% carbon monoxide and 1% methane as byproducts. For reactor modeling in an appropriate range of operating conditions, a simple global kinetics model is proposed; the correspondent parameters were fitted to the experimental data. Thermal coupling between ethanol steam reforming and hydrogen combustion was experimentally studied for subsequent implementation in a parallel-plate reactor, preferably in a so-called folded plate reactor. A single unit of this reactor, consisting of one combustion channel in between two halves of reforming channels was selected for the experimental proof-of-concept. The influence of different operating variables (ethanol load, feed distribution of the combustion fuel along the channel length, operation temperature, and steam-to-carbon ratio) on the reactor performance and the thermal coupling pattern will be discussed.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie202364y

[article]
in Industrial & engineering chemistry research > Vol. 51 N° 11 (Mars 2012) . - pp. 4119–4142

Titre :	Thirty years with EoS / GE models — what have we learned?
Type de document :	texte imprimé
Auteurs :	Georgios M. Kontogeorgis, Auteur ; Philippos Coutsikos, Auteur
Année de publication :	2012
Article en page(s) :	pp. 4119–4142
Note générale :	Chimie industrielle
Langues :	Anglais (eng)
Mots-clés :	Asymmetric mixtures
Résumé :	Thirty years of research and the use of EoS/GE mixing rules in cubic equations of state are reviewed. The most popular approaches are presented both from the derivation and application points of view and they are compared to each other. It is shown that all methods have significant capabilities but also limitations which are discussed. A useful approach is presented for analyzing the models by looking at the activity coefficient expression derived from the equations of state using various mixing rules. The size-asymmetric systems are investigated in detail, and an explanation is provided on how EoS/GE mixing rules should be developed so that such asymmetric mixtures are adequately represented.
ISSN :	0888-5885
En ligne :	http://pubs.acs.org/doi/abs/10.1021/ie2015119?mi=wlbqo9&af=R&pageSize=20&searchT [...]

Industrial & engineering chemistry research / Paul, Donald R. . Vol. 51 N° 11

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