bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of oil viscosity on the rheology of oil‐in‐water emulsions with added solids
Authors: Yan Yuhua , Masliyah Jacob H. 
Published: March 2009

AbstractThis paper reports an experimental study on the effect of oil viscosity on the rheology of oil‐in‐water (o/w) emulsions with added solids. Four oils having a viscosity range of 0.0024 to 306 Pa . s were used. The size ratio of the solids to oil droplets was varied from 2 to 16. The addition of smaller size solids to the emulsions yielded a higher viscosity than that of larger solids at the same solids volume fraction. However, when the solids were sufficiently large such that the emulsions behaved as a continuous phase towards the solids, the viscosity of the emulsion‐solids mixtures tended to be independent of the solids size.The critical size ratio of the solids to oil droplets, above which the emulsions behaved as a continuous phase towards the solids, increased with the oil viscosity. The critical size ratio varied between 3 and 10.
Acid hydrolysis of cellulose. part i. experimental kinetic analysis
Authors: Dadach Zin‐Eddine , Kaliaguine Serge 
Published: March 2009

AbstractThe main objective of this investigation is to obtain experimental data for the sulfuric acid hydrolysis of cotton and mechanically pretreated cotton fibres. These data indicate that some glycosidic bonds of cellulose have very high accessibility to catalytic ions. It was also shown that milling increases the accessibility of some glycosidic bonds of cellulose and decreases the volume of the crystalline regions of cotton. From the glucose yield versus time data, it was found that the effect of milling on the rate of cellulose depolymerization depends on the reactivity and accessibility of the glycon rings of cellulose. It was also found that at 1OO°C, the rate of cellulose depolymerization was not affected by the extraction of cotton wax and this was related to a rolling up process of cotton wax caused by melting. The kinetic constants of glucose degradation and cellobiose hydrolysis have been determined for the stochastic simulation of cellulose depolymerization which is the subject of the second part of this work.
Anaerobic fermentation of xylose by pichia stipitis: The effect of forced cycling of ph
Authors: Ryding Per‐Ola , Nlklasson Claes , Lidén Gunnar 
Published: March 2009

AbstractXylose fermentation by Pichia stipitis was examined using a two‐stage batch process. The cells were first grown aerobically on D‐xylose (5 g/L), whereafter additional xylose (10 g/L) was added and fermented during anaerobic conditions (T=30°C). The optimum pH value for a fermentation with constant pH was found to be 4.5 (maximum specific ethanol production rate 0.21 g/(g h). Forced square wave cycling of the pH between 4 and 5, and 3.5 and 5.5 (cycle time 30 min) during the fermentation stage resulted in a fermentation rate lower than the maximum rate, but with unchanged ethanol yields.
Kinetic modelling of gold cyanide multi‐cycle adsorption and elution using activated carbon in the presence of foulants
Authors: Otu Emmanuel O. , Byerley John J. , Robinson Campbell W. 
Published: March 2009

AbstractA novel procedure was used to study the kinetics of multiple exposure of a granular activated carbon in a laboratory‐scale packed bed to solutions containing gold and sodium cyanide, or in addition one of several organic reagents commonly used in mineral processing. The repeated use of a carbon sample simulated the practice in industrial gold recovery operations. A batch, unsteady state adsorption model which assumed constant intraparticle diffusivity of Au(CN)2‐ was used to model the kinetics of gold uptake. Upon repeated exposure of a carbon sample, up to a 3‐ to 4‐fold decrease in the intraparticle diffusivity of Au(CN)2‐ was observed, combined with a much smaller loss of adsorption capacity.
Determination of mutual solubilities in aniline + n ‐hexane and furfural + cyclohexane systems by a laser light scattering technique
Authors: Ochi Kenji , Momose Masatoshi , Kojima Kazuo , Lu Benjamin C.‐Y. 
Published: March 2009

AbstractA newly developed laser light scattering technique was used for the determination of mutual solubilities in two liquid systems at moderate pressures. The solubility data and the upper critical solution temperatures are reported for the aniline + n‐hexane and furfural + cyclohexane systems. The experimentally determined cloud points were satisfactorily correlated by the NRTL equation.
Local mass transfer for tube banks in two‐phase flow
Authors: Giorgio Ana Chiappori De Del , Cavatorta Omar N. , Böhm Ursula 
Published: March 2009

AbstractThe local mass transfer rate to tubes immersed in gas‐liquid two‐phase systems was studied using the electrochemical method. It was found that the mass transfer distribution around the tube perimeter is not uniform and depends on the geometry of the system, the properties of the liquid phase and the superficial gas velocity.Taking into account the analogy between heat and mass transfer, these results may be useful in both fields.
On‐line determination of supersaturation of a kcl‐nacl aqueous solution based on density measurement
Authors: Redman Terry P. , Rohani Sohrab 
Published: March 2009

AbstractA method is developed for the calculation of the saturation temperature of a KCI‐NaCI aqueous solution, based on the measurement of the density and temperature of a sample solution, and prior knowledge of the NaCl concentration. Experimental density and solubility data for solutions saturated with KCI in the temperature range of 299 to 321 K with concentrations of NaCl greater than 0.200 kg/kg H2O were used to develop the empirical correlation allowing the calculation of the solution saturation level.The method is applicable in the on‐line determination of the level of supersaturation in a KCI crystallizer in which the NaCl concentration is known. Knowledge of the prevailing supersaturation is necessary for the control of crystal purity and crystal size distribution in industrial potash crystallizers.
Analysis of the mechanism of rare earth metal permeation through a liquid membrane with a chelating agent in the
Authors: Kojima Toshinori , Nakayama Chikako , Uemiya Shigeyuki 
Published: March 2009

AbstractThe effect of adding a water‐soluble chelating agent, diethylenetriaminepentaacetic acid (DTPA), to the feed phase was studied on the selective permeation of rare earth metal ions (Ln3+) through a supported liquid membrane (SLM) containing 2‐ethylhexyl phosphoric acid mono‐2‐ethylhexyl ester (PC‐88A). High selectivity of Pr to Nd was observed at a pH of 2.0 in the stripping phase, and selective permeation of La was observed at higher pH values. The permeation mechanism of the Ln3+ was analyzed, and the above results were explained by the change in the concentrations of free Ln3+ in the feed phase and Ln3+/PC‐88A complexes in the SLM with pH.
Measurement and prediction of the density of aqueous ternary mixtures of methyldiethanolamine and diethanolamine at temperatures from 25°c to 80°c
Authors: Teng T. T. , Maham Y. , Hepler L. G. , Mather A. E. 
Published: March 2009

AbstractDensities have been measured for mixed aqueous solutions of N‐methyldiethanolamine (MDEA) and diethanolamine (DEA) at 25, 30,40,50, 60,70, and 80°C. The compositions of the ternary solutions are near 30 mass% solute, because of industrial applications for the absorption of acid gases.The isopycnotic (same density) method, for predicting densities of multicomponent aqueous systems at 25°C has been used to predict the densities of the present non‐electrolyte mixed solutions at other temperatures. Predicted and observed density values are in good agreement (<0.06% error). The method has also been used to predict densities of some aqueous sea salt mixtures at temperatures ranging from 5 to 95°C. Again the predicted and observed values are in good agreement (generally <0.1% error).
A correlation to the solution of the two‐phase dispersion model
Authors: Qabazard Hasan , Johnson Marvin M. , Meier Paul F. 
Published: March 2009

AbstractA correlation to the solution of the two‐phase dispersion model has been developed for gas‐solid fluidized bed reactors operating in the bubbling regime. An analytical solution was obtained for fractional gas conversion by using an exponential function to characterize the dense phase gas concentration profile. The coefficient of the exponential function was found to depend on gas axial dispersion and, in order to determine this parameter, a Peclet number correlation was developed. Model predicted gas conversions were in excellent agreement with experimental conversions for a variety of fluidized bed reaction data over a conversion range from 2.5 to 99%.
Drag on individual cubic assemblies of spheres in non‐newtonian tube flow
Authors: Subramaniam Girish , Zuritz Carlos A. 
Published: March 2009

AbstractAn obstacle in modeling aseptic processing of particulate foods is the lack of a reliable estimator for the drag force of the non‐Newtonian liquid phase on the suspended particles as they flow through the holding tubes of such systems. The objective was to develop an expression for the drag force on cubic assemblies of spherical particles suspended in a pseudoplastic fluid flowing in a tube.An apparatus was assembled for direct measurement of the drag force exerted by solutions of sodium carboxymethyl cellulose (CMC) on the assemblies inside a tube. An empirical drag correction factor, as a function of particle volume fraction (applicable to Stokes' law), was developed.
Non‐newtonian liquid flow through globe and gate valves
Authors: Banerjee Tapan Kumar , Das Manas , Das Sudip Kumar 
Published: March 2009

AbstractExperimental data on the pressure drop across 1/2‐in. globe and gate valves in the horizontal plane for non‐Newtonian pseudoplastic fluids in laminar flow are presented. Generalized correlations in terms of the various physical and dynamic variables of the system have been developed for prediction of the frictional pressure drop for each valve. Statistical analysis of the correlations suggest that they are of acceptable accuracy.
Measurements of voidage profiles in spouted beds
Authors: He Y.‐L. , Lim C. J. , Grace J. R. , Zhu J.‐X. , Qzn S.‐Z. 
Published: March 2009

AbstractA fibre optic probe has been used to measure voidage profiles in the fountain, spout and annulus of spouted beds. The voidage in most of the annulus was found to be somewhat higher than the loose‐packed voidage and increased with increasing spouting gas flow rate, contrary to usual assumptions. There is a denser region in the annulus where the voidage was a little lower than the loose‐packed bed voidage. In the core of the fountain, the voidage decreased with height for low spouting gas flow rate, consistent with the model of Grace and Mathur (1978); however, at higher gas flow rate, it first increased with height and then decreased towards the fountain top. The radial profiles of local voidage were roughly parabolic in the lower portion of the spout and blunt in the upper portion.
Simulation of SO2 absorption by falling water drops
Authors: Hsu Chien‐T'Ai , Shih Shin‐Min , Chang Ching‐Yuang 
Published: March 2009

AbstractThe experimental data of Walcek et al. (1981) for SO2 absorption by falling water drops of 600 μm dia. at 13‐15°C and 1‐50 vol% SO2 in air can be well predicted by a model which ignores the effect of internal circulation and considers the diffusion of both SO2H2O and HSO3 and the accompanying equilibrium dissociation reaction of SO2.H2O within the drop. The data can also be described by the analytical solution obtained by simplifying the rigorous model with the assumption that the gas phase mass transfer resistance is negligible and that the difhtsivities of sulfur species are equal.
Preparation, characterization and activity of wet‐proofed Pt/silicalite catalysts
Authors: Rangwala H. A. , Wanke S. E. , Otto F. D. 
Published: March 2009

AbstractA procedure for wet‐proofing Pt/silicalite catalysts with polytetrafluoroethylene fibres is described. The procedure yielded catalysts with stable and high activities for the exchange of hydrogen isotopes between liquid water and hydrogen gas. Characterization of the catalysts by hydrogen chemisorption and scanning electron microscopy showed that the wet‐proofing procedure can produce catalysts in which most of the Pt surface in the Pt/silicalite before wet‐proofing can remain accessible. Hydrogen chemisorption was found to be a valuable tool for prescreening of wet‐proofed catalysts.
Mise au point d'un absorbeur par voie semi‐sèche à base d'un venturi haute énergie
Authors: Kholi Nizar , Benachour Mohand , Zoulalian André 
Published: March 2009

AbstractAfin de minimiser le volume de I'absorbeur, l'étude porte sur la mise au point d'un dispositif de traitement, par voie semi‐sèche, d'un effluent gazeux acide (SO2 dans l'air) à base d'un venturi hauteétnergie. Une comparaison expérimentale entre trois dispositifs permet, en fonction des paramètres opératoires étudiks, de choisir le dispositif, dénommé C, dont les capacités d'évaporation et d'absorption réactionnelles sont nettement supérieures aux deux autres. Pour le dispositif C, on prtcise ensuite les conditions opératoires et géométriques optimales. L'absorption de SO2 est effectuée soit dans une solution d'hydroxyde de sodium, soit dans une suspension d'hydroxyde de calcium. Dans ce dernier cas, les résultats obtenus sont supérieurs à ceux obtenus sur des dispositifs plus conventionnels à base de tours d'atomisation.
Identification and control of an industrial steam‐reforming plant
Authors: Meziou A. M. , Alatiqi I. M. 
Published: March 2009

AbstractReliable mathematical models for an industrial steam‐gas reformer and a steam‐boiler are simulated and used to study the dynamic behavior of the two coupled processes. Simulation results of the identified system are in good agreement with the nonlinear process operation.Three control loops are considered for multivariable control system design. These are Hydrogen product temperature and quality, and boiler water level. A new multivariable control structure is obtained, which manipulates steam‐to‐carbon (S/C) ratio for the control of coil outlet temperature (COT), the fuel gas rate to control hydrogen product quality (conversion) and the boiler feed water to control drum level. The selected structure is then tuned using the Biggest‐Log modulus‐Tuning (BLT) method. Results show a very satisfactory response of the temperature and quality loops with the BLT based controllers. It is also found that the boiler water level loop is partially decoupled from the other two loops and hence does not need to be detuned according to BLT criterion.The new multivariable control structure is compared with the conventional control utilising fuel gas rate to control COT. Closed‐loop simulation results show a better performance for the multivariable structure under continuous operation.
Multicomponent ion exchange column dynamics
Authors: Tan Henry K. S. , Spinner Irving H. 
Published: March 2009

AbstractSimple model equations which consider different rate control mechanisms are formulated for fixed bed multicomponent ion exchange processes. Efficient and accurate numerical methods are developed for solving these equations for liquid phase, solid phase or combined phase control. The algorithms are applicable to both ion exchange and liquid adsorption and are shown to be extendable to a general form of isotherms. The accuracy of the numerical algorithm is evidenced by the fact that the asymptotic limiting equilibrium solutions are closely approached as the dimensionless length parameter is increased, regardless of the rate control mechanism.Numerical examples for ion exchange applications are presented. These examples included multicomponent elution and purification problems. The effect of mass transfer resistance was also examined. Other examples examine the validity of a model reduction assumption and the comparison of equilibrium theory with the results obtained using the present finite mass transfer rate model.
A proposed method for the calculation of theoretical plates in liquid‐liquid‐solid three‐phase extraction columns: Methanol, hexane and rapeseed meal system
Authors: Shi Meiren , Shen Shiquan , Liu Jian 
Published: March 2009

AbstractA program is designed and tested to calculate the number of theoretical plates required in a LLS extraction column for the methanol, hexane, and rapeseed meal system. The calculation model takes into account the internal mixing effect of solid entrainment in the light phase. The concentration distribution along the column can also be obtained from the model by introducing the efficiency of real plates.
Experimental evaluation of molten caustic leaching of an oil sand coke residue
Authors: Ityokumbul Mku T. 
Published: March 2009

AbstractAn evaluation of molten caustic leaching, MCL, for the desulfurization and demineralization of Syncrude fluid coke has been carried out. The results obtained indicate that with the incorporation of an acid washing step, a treated coke product having sulfur and ash contents of less than 1 % may be obtained. Scanning electron microscopy confirm that vanadium is released during molten caustic leaching. At caustic to coke mass ratio in the range 1.8 ‐ 2.0, the dedlurization reaction was determined to be independent of particle size, thus suggesting chemical reaction control.
Characteristics of heavy‐oil‐in‐water emulsions containing produced sand
Authors: Jamaluddin A. K. M. , Bowen C. T. , Gillies R. , Small M. , Nazarko T. W. 
Published: March 2009

AbstractHeavy‐oil‐in‐water (o/w) emulsions containing produced sand were prepared using commercially available emulsifiers. The emulsions were tested in beakers for emulsion type, quality, and sand‐retention characteristics. The apparent viscosities of the o/w emulsions were measured. The effects of polymer addition on the apparent viscosity and sand‐carrying capability of the emulsions were also studied.The results of the breaker tests indicate that most emulsifier solutions water‐wet the beaker wall and temporarily improve heavy‐oil flow characteristics. However, most of the chemicals also water‐wet the sand particles and cause sand dropout. The Flothin F2 chemical alone showed stable oil dispersion and, in combination with the Flocon 4800C polymer, showed very good sand‐retention, viscosity‐reduction, and stable oil‐dispersion characteristics.
Oscillating grid turbulence and bulk mixing at high schmidt numbers
Authors: Kostazos A. E. , Apikides P. S. , Kastrinakis E. G. , Nychas S. G. 
Published: March 2009

AbstractThe mixing process of high Schmidt number (700‐35000) aqueous solutions was investigated in an oscillating grid mixing vessel. The influence of the following variables on the mixing time was studied: Schmidt number, initial solution concentration, volume ratio of the liquids to be mixed and oscillating grid frequency. The measurements were compared with Corrsin's isotropic turbulent mixing theory. The data were correlated in the form of dimensionless groups, involving the aforementioned variables.
Optimal periodic forcing of nonlinear chemical processes for performance improvements
Authors: Chen Chien‐Chong , Hwang Chyi , Yang Ray Y. K. 
Published: March 2009

AbstractUnsteady‐state periodic operations can improve the optimal steady‐state performance of nonlinear chemical processes. To examine if the optimal periodic operation is proper and to obtain the optimal forcing functions subject to various control and state constraints it is suggested in this paper to convert the problems into a form which is suitable for constrained nonlinear programming. The adopted numerical optimization method is based on employing the control parametrization technique and is thus capable of dealing with the problem of multiple input forcings and obtaining optimal forcing functions and/or parameters while subject to general constraints. Besides, it provides information about to what extent the process performance can be improved by adopting the optimal periodic control.
Application of a fuzzy match inference strategy in synthesis of separation systems
Authors: Qian Yu , Lien Kristian M. 
Published: March 2009

AbstractSymbolic representation and sequential processing of information in most expert systems have made it difficult to represent continuous variables and to model interactions among different parts of a large process system. This paper proposes a new approach, principally aimed at function oriented engineering design problems. Continuous variables and qualitative information are treated as fuzzy sets. A fuzzy match inference strategy is proposed to assess design schemes with rules in parallel. The fuzzy match inference strategy is then extended to multi‐step decision making in the synthesis of multicomponent separation sequences. The new concepts have been implemented in a prototype expert system, where the selection of separation technologies and sequencing of separators are approached in an integrated manner. It is shown from several examples that the inference strategy yields promising results in quantitative evaluation of process synthesis and combinatorial optimization.
Biodegradation of aromatic compounds in a self‐cycling fermenter (SCF)
Authors: Sarkis Bassam E. , Cooper David G. 
Published: March 2009

AbstractThe Self‐cycling fermentation (SCF) technique was applied to the biodegradation of several aromatic compounds by Pseudomonas putida and Pseudomonas fluorescens. The SCF technique was shown to have several advantages over the sequential batch reactor and other methods of biodegradation. The SCF technique allowed stable and repeatable performance over an extended period of time, with almost complete substrate consumption. The system was flexible and easily adapted to changes in concentration and/or type of substrate. The rates of consumption were considerably higher than reported for any other biodegradation technique.
Modeling and simulation of the drying of thin sheets in a continuous infrared dryer
Authors: Dhib R. , Broadbent A. D. , Thérien N. 
Published: March 2009

AbstractThe model gives the temperature and moisture distributions of the air, and of the moist sheet, as a function of time and distance in the dryer. The influence of the sheet's velocity and that of the radiant energy on the dryer performance as well as the effect of the moisture content of the entering sheet have been studied. A set of 27 experiments was carried out using the infrared dryer in order to calibrate the model. In these, the following three variables each had three operational levels: web velocity, initial web moisture and heating power. The model predictions agreed very well with the experimental data. Model predictions using arithmetic averages for the parameters, and parameters correlated with operational variables, are also presented and discussed.
Separation of monoclonal IgM antibodies using tangential flow ultrafiltration
Authors: Krishnan Mani , Kalogerakis Nicolas , Behie Leo A. , Mehrotra Anil K. 
Published: March 2009

AbstractExperimental results are presented for the separation of monoclonal IgM antibodies from hybridoma cell cultures using tangential flow ultrafiltration with total recycle of the retentate. IgM antibodies are pentameric immunoglobulin molecules with a molar mass of 900 kDa and a tip‐to‐tip distance of 38 nm. The major impurity (foulant) in the supernatant sample was albumin, whose molar mass and diameter are 67 kDa and 7 nm, respectively. The antibody (product) recovery rate, variations in the permeation velocity and the time for a 90%‐reduction in feed volume were investigated using 100 and 300 kDa NMWCO membranes at three transmembrane pressures and two tangential velocities. A model is also presented, in which the ultrafiltration process is divided into two regimes: the surface fouling regime (characterized by the adsorption of antibody molecules on the membrane surface) and the internal fouling regime (characterized by pore‐blockage due to deposition of foulant protein molecules). Approximately 16% of the effective membrane area was blocked in the surface fouling regime. The model predictions are in satisfactory agreement with the experimental results.