bluuebunny/crossref_metadata_2025_split huggingface dataset:
A New Method for Identifying Osmotically Limited and Gel Layer Controlled Pressure Independent Flux in Ultrafiltration
Authors: Zaidi S. K. , Karode S. K. , Kirpalani D , Kumar A 
Published: July 2010

AbstractAn unequivocal determination of whether pressure independent flux regime is osmotically controlled or gel layer dominated, is still open for discussion in the membrane literature. The present work reports a method that could be used to address this issue. It is shown that analysis of post steady state transient filtration data leads to clear demarcation of osmotically limited and gel layer controlled filtration. The method proposed in this work can also be used to estimate the additional filtration resistance offered by the polarization layer to the permeate flow in macromolecular ultrafiltration and has been verified experimentally. It has also been shown that the polarization layer thickness is not sensitive to the feed pressure but varies as a function of the bulk solute concentration; higher the bulk concentration, thicker is the polarization layer.
Evaluation of Polyester Resin as a New Compatibilizer for SBR/PVC Blends
Authors: Abd‐El‐Messieh S. L. , Mansour S. H. , El‐Nashar D , Ikladious N. E. 
Published: July 2010

AbstractA polyester (PE) based on the glycolyzed products of PET was prepared and added in different concentrations to a series of SBR/PVC blends. The addition of the polyester showed that all properties of SBR/PVC blends were improved by incorporation of PE. Highest mechanical strength values were obtained at a polyester concentration of 7.5 phr. Thermal analysis as well as dynamic mechanical properties of SBR/PVC blends after the addition of 7.5 and 10 phr polyester indicated one single glass transition temperature. The dielectric losses (ϵ") were analyzed in the frequency domains in the two terms of Fröhlich related to the Maxwell Wagner effect and the orientation of the aggregates caused by the movement of the main chain. The permittivity (ϵ') values were found to increase by increasing the polyester content. This increase was followed by a decrease in the ϵ" up to a 7.5 phr polyester content after which no pronounced change was noticed.
Numerical Investigation of Resonance Behaviour of a Tubular Packed‐Bed Reactor with Non‐Uniform Activity
Authors: Jaree Attasak , Hudgins Robert R. , Budman Hector M. , Silveston Peter L. , Menzinger Michael 
Published: July 2010

AbstractThe effects of periodic temperature perturbations at the inlet of a packed‐bed catalytic reactor were investigated for a system of non‐uniform catalyst activity that could arise through catalyst deactivation. A simplified model consisting of zones of active catalyst and inert packing of similar thermal properties was assumed. Simulations showed that large amplification, expressed as gain, can occur. The largest gain is observed at a resonance frequency. Both gain and resonance frequency depend on the number of layers of active catalyst and inert packing, the depth of the inert packing and catalyst layers.
Size Segregation of Nickel Pellets Flowing into a Packed Bed
Authors: Moysey Paul A. , Rama Rao Nadella V. , Baird Malcolm H. I. 
Published: July 2010

AbstractThe size segregation of nickel pellets fed to a packed bed has been measured with mixtures of sizes ranging from less than 1 mm to about 10 mm. The pellet mixture is fed to one side of a rectangular cell and then samples are removed from different lateral positions in the cell for screen analysis. During the feeding process the finer pellets tend to percolate vertically downwards while the larger pellets tend to roll down the sloping surface of the bed. The resulting segregation has been correlated with the size distribution of the feed pellets and the lateral position in the cell, using polynomial equations with three or four adjustable coefficients.
Kinetics of Bitumen‐Derived Gas Oil Upgrading Using a Commercial NiMo/Al2O3 Catalyst
Authors: Botchwey Christian , Dalai Ajay K. , Adjaye John 
Published: July 2010

AbstractHydrotreating (HT) kinetics of Athabasca bitumen‐derived gas oil has been studied between 340 to 420°C using a commercial NiMo/γ‐Al2O3 catalyst. The kinetics analyses included overall conversion of high‐boiling species into low‐boiling products, hydrodenitrogenation (HDN) of total, basic and non‐basic nitrogen compounds and hydrodesulfurization (HDS). Three temperature regimes were marked out for the kinetic analyses: low (340‐370°C), intermediate (370‐400°C) and high (400‐420°C). The mechanism for the conversion of high to low‐boiling species was observed to change from one temperature regime to the other, giving rise to different activation energies. HDS and HDN activation energies increased in the order: high < low < intermediate severity temperature regime.
Comparison of Internal and External Mixer Spargers in a Laboratory De‐inking Flotation Column
Authors: Hardie C. A. , Gomez C. O. , Finch J. A. 
Published: July 2010

AbstractColumn flotation has been introduced for waste paper de‐inking to take advantage of low capital cost and excellent separation performance. Bubble generation employs a variety of systems, broadly divided into two types: internal and external. An external in‐line static mixer sparger was tested against an internal porous stainless steel sparger. They were compared in an industrial de‐inking facility using a 10 cm diameter column. Operating conditions were defined and the effect of gas rate, retention time, wash water rate, and froth height on de‐inking was investigated. Both spargers gave similar ink recovery and fiber loss as a function of bubble surface area flux. However, the static mixer gave stable operation while the porous sparger showed evidence of plugging over a 6h test. Combined with some ability to control bubble size, overall the in‐line static mixer gave superior performance.
Optimization of Reaction Conditions in a Fluidized‐Bed for Silane Pyrolysis
Authors: Tejero‐Ezpeleta Maria P. , Buchholz Sigurd , Mleczko Leslaw 
Published: July 2010

AbstractThe fluidized‐bed chemical vapor deposition (CVD) process for polycrystalline silicon production is considered to be the most attractive alternative to the conventional bell‐jar process. In order to obtain stable operation, high space‐time‐yields and high purity of the product several obstacles have to be eliminated. Reaction conditions must be optimized to avoid the homogeneous decomposition of silane and minimize silicon dust formation. The effect of temperature, silane partial pressure, gas velocity and the size of bed particles has to be identified. These dependencies and the interaction between hydrodynamics and kinetics of homogeneous and heterogeneous CVD‐reactions were studied in a laboratory‐scale fluidized‐bed reactor.
A Hydration Shell‐Based Thermodynamic Model for Aqueous Two‐Phase Systems
Authors: De Alcântara Pedro , Filho Pessôa , Mohamed Rahoma S. 
Published: July 2010

AbstractIn this work a Flory‐Huggins model modified to account for some unique features of Aqueous Two‐Phase Systems is presented. The model takes into account observed solvation between water and polymer molecules through the incorporation of a hydration shell to express the number of water molecules bonded to each polymer molecule. The parameters of the modified equation were determined using experimental data of ATPS containing poly (ethylene glycol) and dextran. The results revealed remarkable improvement in the correlation ability of the model. A general expression that defines the number of water molecules in the hydration shell was also obtained.
Understanding Water‐Based Bitumen Extraction from Athabasca Oil Sands
Authors: Masliyah Jacob , Zhou Zhiang Joe , Xu Zhenghe , Czarnecki Jan , Hamza Hassan 
Published: July 2010

AbstractThe current state of knowledge on the fundamentals of bitumen recovery from Athabasca oil sands using water‐based extraction methods is reviewed. Instead of investigating bitumen extraction as a black box, the bitumen extraction process has been discussed and analyzed as individual steps: Oil sand lump size reduction, bitumen liberation, aeration, flotation and interactions among the different components that make up an oil sand slurry. With the development and adoption of advanced analytical instrumentations, our understanding of bitumen extraction at each individual step has been extended from the macroscopic scale down to the molecular level. How to improve bitumen recovery and bitumen froth quality from poor processing ores is still a future challenge in oil sands processing.
Interaction between Bitumen and Fines in Oil Sands Extraction System: Implication to Bitumen Recovery
Authors: Liu Jianjun , Xu Zhenghe , Masliyah Jacob 
Published: July 2010

AbstractColloidal interactions between bitumen and fines, extracted directly from oil sand ores, were investigated with zeta potential distribution measurement and surface force measurement using an atomic force microscope (AFM). Fines from good processing ores exhibit a negligible attachment to bitumen surfaces, due to hydrophilic nature of the fines. Fines from poor processing ores exhibit a stronger attachment to bitumen surfaces by an attractive hydrophobic force between bitumen and fines, due to hydrophobic nature of the fines and the presence of high concentration divalent cations in the processing water.
Fines/Water Interactions and Consequences of the Presence of Degraded Illite on Oil Sands Extractability
Authors: Wallace Dean , Tipman Robert , Komishke Brad , Wallwork Vince , Perkins Ernie 
Published: July 2010

AbstractThe chemical composition of the aqueous phase in oil sand slurries influences bitumen recovery from oil sands, especially those containing greater than 10% fines. The composition is controlled by a combination of mixing and dilution, ion exchange with clay surfaces and precipitation of divalent ions as carbonate minerals. Elevated levels of soluble potassium in the oil sand, which appear to be a marker for degraded illite or smectitic clays, are associated with depressed bitumen recovery. These clays have a swelling character and can contribute divalent ions to the slurry by ion exchange between the clay mineral surfaces and the process water.
A Perspective on the Selection of Froth Treatment Processes
Authors: Shelfantook William E. 
Published: July 2010

AbstractTreating of froths produced in extraction plants processing surface‐mined oilsand presents an interesting and challenging array of problems. Much of what we do to the feed ore to maximize recovery of bitumen creates surfactant/biwettable solids mixtures that stabilize water‐in‐oil emulsions. These persist despite our most strenuous attempts to break them. Temperature and solvent selection both influence the performance of froth treatment processes. However, often we do not look at the broader implications of either in new or expanding ventures. This paper presents another perspective, showing how both temperature and solvent selection influence the outcome of froth treatment.
Investigation of Oil Sands Froth Treatment
Authors: Romanova Uliana G. , Yarranton Harvey W. , Schramm Laurier L. , Shelfantook William E. 
Published: July 2010

AbstractTwo oil sand froth treatment methods are investigated: 1) dilution with an aromatic solvent followed by centrifugation (AS Method); 2) dilution with a paraffinic solvent followed by gravity settling (PS Method). The effectiveness of the methods is assessed in terms of bitumen recovery and the water content in the recovered diluted bitumen. The optimum solventto‐bitumen ratios are identified considering process type, ore quality, temperature, and residence time.
Effects of Sand Fraction on Toluene‐diluted Heavy Oil in Water Emulsions in Turbulent Flow
Authors: Angle Chandra W. 
Published: July 2010

AbstractThe impact of the presence of sand on emulsification of toluene‐diluted heavy oil in simulated process water was systematically studied as a function of agitation time, in a stirred tank. Droplet size distributions were measured by light scattering technique. Optical microscopy and high‐speed video micrography were used to visually monitor agitation and emulsion stability. Results showed that the Sauter mean diameters of the droplets decreased with increasing sand content. Droplet breakage followed a first‐order kinetic model for all mixing speeds. Plots of droplet volume percent frequency versus droplet size followed lognormal distribution. The distribution span broadened into lower sizes with increased sand content. Emulsions were stable for over 48 h after formation.
A Bench‐Scale Study of Conditioning Behaviour in Oil Sands Slurries
Authors: Friesen Waldemar I. , Dabros Tadeusz , Kwon Teddy 
Published: July 2010

AbstractProper conditioning of an oil sand/water slurry is essential for the efficient extraction of bitumen. The conditioning process depends on such variables as ore grade, temperature, mixing intensity, mixing time, and water composition. A technique has been developed in which a microscope and video cameras are used to observe a slurry stirred in a glass cell to evaluate, on a comparative basis, the effect of conditioning parameters on bitumen recovery. Several ores and their blends were studied and found to exhibit large differences in their conditioning behaviour. The method offers the capability of diagnosing ore processability problems and optimizing slurry conditioning.
Analysis of Solvent‐Diluted Bitumen from Oil Sands Froth Treatment Using NIR Spectroscopy
Authors: Long Yicheng , Dabros Tadeusz , Hamza Hassan 
Published: July 2010

AbstractProcess control and optimization of bitumen froth treatment during oil sands processing require rapid analysis of asphaltene content in bitumen, solvent‐tobitumen ratio (S/B), and the density of solvent‐diluted bitumen. NIR spectroscopy was employed to meet this requirement. The NIR system comprised a spectrometer with no moving parts coupled with a double‐pass transflectance probe via a fiber‐optic cable. Quantitative calibration models were established using partial leastsquares regression in latent variables. The standard errors of calibration were 0.20 wt% for 0 to 20 wt% asphaltenes in bitumen, 1.1 wt% for 20 to 100 wt% asphaltenes in bitumen, 0.1 for S/B of solvent‐diluted bitumen, and 0.0017 g/mL for density of solvent‐diluted bitumen. It was shown that the process conditions could be monitored through the spectral scores from principal component analysis.
Adhesion of Bitumen to a Metal Surface in a Flowing Oil Sands Slurry
Authors: Xu Yuming , Dabros Tadeusz , Friesen Waldemar I. , Maciejewski Waldemar B. , Czarnecki Jan 
Published: July 2010

AbstractBench‐scale experiments were conducted to study the behaviour of oil sands slurries. While a slurry was being stirred with a standard impeller, the mass of bitumen, Mad, that adhered to a steel probe dipped into the slurry was measured. Mad remained small up to a critical adhesion time, τad, and then increased rapidly. τad depended on ore grade, temperature, pH, and clay content. The implication for hydrotransport of oil sands is clear: τad should be greater than the residence time of the slurry to avoid the problem of bitumen coating the pipe wall and the attendant increase in pumping pressure.
Langmuir and Langmuir‐Blodgett Asphaltene Films at Heptane‐water Interface
Authors: Lawrence Steven , Zhang Li Yan , Xu Zhenghe , Masliyah Jacob 
Published: July 2010

AbstractMonolayer characteristics of subfractions and unfractionated whole asphaltenes from Athabasca oil sands bitumen were studied at heptane‐water interface. The transferred Langmuir‐Blodgett films of asphaltenes were characterised with atomic force microscopy and contact angle measurements. Monolayers prepared from the three asphaltene samples are found to behave similarly at heptane‐water interface. The high molecular weight asphaltene monolayer is the most expanded one whereas the low molecular weight asphaltene monolayer is the most condensed one. An asphaltene monolayer behaves differently at an airwater interface to a heptane‐water interface. The presence of the bulk heptane phase renders the interfacial asphaltene monolayer more flexible as compared to that at air‐water interface.
Performance of Sand Slurry Pipelines in the Oil Sands Industry
Authors: Sanders R Sean , Schaan Jason , Hughes Roxby , Shook Clifton 
Published: July 2010

AbstractOperating data for several slurry pipelines in the Alberta oil sand industry have been sampled and interpreted with the assistance of the Saskatchewan Research Council (SRC) Two‐Layer model. The slurries are described within the industry as normal tailings, dense tailings, or oil sand slurries. All are of the so‐called heterogeneous or settling slurry type. The pipelines considered ranged in diameter between 0.483 m and 0.737 m. The useful operating data included water and slurry pressure drop measurements recorded during periods in which velocities and densities were nearly constant. The data reveal that the friction is often higher than predicted by the SRC Two‐Layer model, which makes no allowance for the effect of large particles (>50 mm) which are known to be present. This friction increment appears to be higher when the pipelines have sections with upward slopes.
Flow Regime Identification in a Slurry Bubble Column from Gas Holdup and Pressure Fluctuations Analysis
Authors: Barghi S , Prakash A , Margaritis A , Bergougnou M. A. 
Published: July 2010

AbstractAnalysis of gas holdups and pressure fluctuations are conducted in a slurry bubble column to study changes in flow regimes and comparisons are made with solid‐free bubble column. The pressure fluctuations are measured by fast response pressure transducers mounted on the column wall in the distributor and bulk regions. Air, tap water and 35 micron glass beads are used as the gas, liquid and solid phases respectively. Statistical analysis of pressure fluctuation data combined with gas holdup analysis provided information about flow regime transition and interesting insights into bubble size distributions and changes in flow structure.
Oxygen Transfer in a Baffled Rectangular Air‐Lift Loop Reactor
Authors: Couvert Annabelle , Bastoul Dominique , Roustan Michel , Chatellier Patrice 
Published: July 2010

AbstractThe objective of this study is to characterize mass transfer in a rectangular air‐lift loop reactor in two‐phase flow. In a previous work, it has been shown that the reactor presents a complex gas flow pattern. Therefore, first, the global mass transfer volumetric coefficient kLa was measured in two‐phase flow, by three methods (two based on the liquid phase mass balance, one based on the gas phase mass balance). Then, second, a localized analysis was implemented in order to obtain more information about the phenomena governing the gas phase flow.
Determination of Nucleation and Crystal Growth Kinetics in Hostile Environment &&num;0150; Application to the Tetravalent Uranium Oxalate U(C2O4)2. 6H2O
Authors: Bertrand‐Andrieu Murielle , Plasari Edouard , Baron Pascal 
Published: July 2010

AbstractA specific apparatus and an original batch method are developed for, respectively, nucleation and crystal growth rate measurements in a hostile environment, such as glove box. Primary nucleation and crystal growth kinetic rates for uranium oxalate are measured over a wide range of temperatures and solution concentrations. The nucleation rate obeys the Volmer‐Weber equation, with activation energies of 182 kJ.mol−1 for the homogeneous nucleation and 102 kJ.mol−1 for the heterogeneous one. The crystal growth rate is first order with respect to the supersaturation and controlled by a surface integration mechanism, characterized by a 29 kJ.mol−1 activation energy.
Dehydration of Methanol to Dimethyl Ether by Catalytic Distillation
Authors: An Weizhu , Chuang Karl T. , Sanger Alan R. 
Published: July 2010

AbstractThe kinetics of liquid catalytic dehydration of methanol over an ion exchange resin (Amberlyst 35) has been determined for the temperature range 343 to 403 K using a batch reactor. The experimental data are described well by an Eley‐Rideal type kinetic expression, for which the surface reaction is the rate‐determining step. A catalytic distillation process for methanol dehydration to dimethyl ether (DME) has been modeled using the experimentally determined kinetic data. The results were incorporated into the rate‐controlled reaction mode for RadFrac, a part of the commercial simulation program Aspen Plus. It was shown that synthesis of high purity DME can be achieved using a single catalytic distillation column. Thus there is significant potential for reduction of overall capital cost for a plant for methanol dehydration to DME when compared to conventional production facilities that involve separate reaction and distillation processes.
Analysis of Drying Kinetics of Iron Ores using Irreversible Thermodynamics and Transport Phenomena Principles
Authors: Oliveira Idalmo M. , Seshadri Varadarajan , Mansur Marcelo B. 
Published: July 2010

AbstractDrying kinetics of iron ores, the primary raw material for the iron and the steel industry, has been studied in this work. Experimental drying kinetics and equilibrium moisture content data have been obtained using thermogravimetric techniques at controlled conditions of humidity, temperature and gas flow. A theoretical model based on the principles of irreversible thermodynamics and transport phenomena, and a computer program for the simulation of drying process has been developed (SimDry 1.0 for Windows). The results of simulation have been compared with the experimental results and there has been reasonable agreement between them.
Experimental and Numerical Modeling Studies of Arsenic Removal with Wood Ash from Aqueous Streams
Authors: Rahman Mohammod H. , Wasiuddin Nazimuddin M. , Islam M Rafiqul 
Published: July 2010

AbstractMost of the arsenic removal processes are not cost‐effective and/or not efficient in removing As (III). In this research, it was found that Maple wood ash has the potential to adsorb both As (III) and As (V) from contaminated aqueous streams at low concentration levels without any chemical treatment. Static tests showed up to 80% arsenic removal and in various dynamic column tests the arsenic concentration was reduced from 500 ppb to lower than 5ppb. Finally, the ash column was modeled using the surface excess theory. The identified model significantly facilitates practical design of arsenic adsorption system.
Water‐Based Bitumen Recovery from Diluent‐Conditioned Oil Sands
Authors: Hupka Jan , Miller Jan D. , Drelich Jaroslaw 
Published: July 2010

AbstractImportant process development aspects leading to more efficient bitumen recovery from diluent‐conditioned oil sands by water‐based methods are discussed. Bitumen viscosity of 0.5–2 Pa·s is required at the processing temperature and can be reduced to this level by bitumen dilution with an organic solvent. Oil sand porosity, however, poses a restriction on the amount of diluent that can be accepted by the oil sand. Also oil sand‐diluent conditioning time is an important process parameter and can vary from a few minutes for oil sands with low‐viscosity bitumen to several hours if viscosity of the bitumen is high. Additionally, the bitumen separation efficiency during digestion and flotation can be enhanced by reducing the bitumen/water interfacial tension through addition, for example, of tripolyphosphate to the aqueous phase.
Dispositif de déposition de couches de suspensions de céramiques appliqué à la stéréolithographie
Authors: Dufaud Olivier , Corbel Serge 
Published: July 2010

AbstractUn dispositif de déposition de couches uniformes de suspensions de céramiques a été mis au point en vue d'applications pour le prototypage rapide. Le système de raclage se compose d'une buse d'injection de gaz de hauteur, d'angle d'attaque et de pression réglables. L'homogénéité des couches étalées ainsi que la reproductibilité du procédé ont été étudiées. La mise en place d'un plan d'expérience a également conduit à la caractérisation de l'influence de chaque paramètre sur l'épaisseur de couche déposée et a permis de proposer un modèle mathématique fiable en vue d'optimiser le dispositif de dépôt.