bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of gas‐liquid chromatography to the study of gas‐bitumen interactions
Authors: Smith John , Patterson Donald 
Published: March 2009

AbstractGas‐liquid chromatography (glc) has been used (Xu and Hepler, 1990) to obtain Henry's Law constants and infinite dilution activity coefficients for hydrocarbon and other vapour‐phase solutes in two bitumens, Athabasca and Wolf Lake. Thermodynamic interaction between components widely different in molar mass can, however, be characterized by mass‐fraction rather than mole‐fraction based quantities and by the χ parameter, as has been the practice with polymer systems. The new parameters have been calculated and reveal more unfavorable interactions of the solutes with Wolf Lake than with the Athabasca material.
Multi‐dimensional model of a spouted bed
Authors: Krzywanski R. S. , Epstein N. , Bowen B. D. 
Published: March 2009

AbstractA multi‐dimensional model is developed to describe the fluid and particle dynamic behaviour of spouted beds. The position of the spout‐annulus interface is determined by a variational analysis. Two‐fluid equations are used to represent gas and solids motions in the spout while the vector Ergun equation and soil mechanics equations are employed to describe, respectively, gas and solids behaviour in the annulus. Using numerical finite difference methods, the set of governing equations is solved subject to carefully chosen boundary conditions. The model predictions of key hydrodynamic characteristics are in reasonable agreement with available measured data selected from the literature to represent a wide range of experimental conditions.
Effects of fuel type and operating conditions on SO2 emission in fluidized bed combustion
Authors: Zhang J. Q. , Jones W. E. , Lav I. T. , Friedrich F. D. 
Published: March 2009

AbstractThe SO2 emission from six fluidized bed combustors was examined. Approximately 71.5% of the fuel sulphur was found to be emitted as SO2 in sorbent‐free tests. General observations on the effects of Ca/S molar ratio, limestone size and recycle systems are presented. The effects of limestone type and superficial velocity were found to be insignificant, as was the effect of bed temperature in the range 800‐950°C. In tests with fine solid and liquid fuels, circulating FBC's were found to provide significantly better sulphur capture than bubbling FBC's.
Précipitations sélectives des métaux solubilisés biologiquement de boues aérobies d'épuration
Authors: Couillard D. , Mercier G. 
Published: March 2009

AbstractLa précipitation sélective et successive des métaux provenant de la solubilisation biologique (Thiobacillus ferrooxidans) des métaux des boues d'épuration a été étudiée. En parallèle, des figures théoriques représentant la solubilité des hydroxydes et des carbonates des métaux (Ca, Mg, Fe, Al, Cu, Zn, Ni, Cd, Mn) et de leur complexes sont comparées aux valeurs expérimentales. Le pH a été augmenté par étapes à l'aide de Ca(OH)2. Le précipité d'hydroxyde de fer, le moins contaminé, fut obtenu à pH 3.5. Les pH théoriques de précipitation acceptable des métaux ont été identifyés comme: Fe+3 à pH 3.2, Al+3 À pH 4.7, Cu+1 é a pH 6.9, Zn+2 à A pH 8.15, Ni+2 à pH 8.4 et Mn+2 a pH 9.1 et s'approchent des valeurs théoriques. L'ion hydroxyde contrǒle la solubilité de Ca, Mg et Cu. Un précipité avec environ 20% de Cu peut étre obtenu à pH 7 aprés que l'hydroxyde ferrique ait été précipité. La récupération des métaux autre que le fer est donc possible.
Kinematic viscosity studies of the binary ethane‐ 1,2‐diol/ n, n‐dimethylformamide solvent system at various temperatures
Authors: Corrandini Fulvio , Marchetti Andrea , Tagliazucchi Mara , Tassi Lorenzo , Tosi Giuseppe 
Published: March 2009

AbstractKinematic viscosity data (ν) are presented for ethane‐1,2‐diol, for N, N‐dimethylformamide and for nine binary mixtures in the ‐ 10°C to 80°C temperature range. The experimental data were fitted by several empirical relations such as Grunberg‐Nissan (1949), McAllister (1960), Heric (1966), Lobe (1973), Auslander (1964) and polynomial equations. Some considerations regarding the meaning of the obtained adjustment parameters are made. Furthermore, a new best fit equation is proposed and its validity has been compared to that of the other relations on the basis of the reproducibility of the experimental data.
Phase equilibria of crude oils using the continuous thermodynamics approach
Authors: Koral Sunil L. , Sayegh Selim G. , George Albert E. 
Published: March 2009

AbstractThis paper deals with the application of continuous thermodynamics to light and heavy oil systems using the Peng‐ Robinson equation of state. The composition of the high molar mass components in a reservoir oil is described by a continuous distribution function of some characterizing quantity, e.g. molar mass or boiling temperature. Numerical Gaussian quadrature methods are used to generate pseudo‐components and their mole fractions from distribution data. Several examples are presented for phase equilibria of solvent/crude oil systems. The results showed that semi‐infinite distribution functions, such as the Γ function, cannot be applied to all cases, e.g. dew point calculations. The Gauss‐ Legendre quadrature method coupled with spline fitting worked best for heavy oil systems.
A three‐dimensional finite element analysis of the effect of reynolds number on extrudate swell of newtonian liquids from square dies
Authors: Gifford W. A. 
Published: March 2009

AbstractThe effect of Reynolds number upon the extrusion of a Newtonian fluid exiting a square die is examined. It is shown that the extrudate swells at low Reynolds number but contracts at high ones. At zero Reynolds number, the maximum die swell ratio of 1.2 occurs. A swell ratio of one occurs at a Reynolds number of about 24. At large Reynolds numbers, the extrudate contracts to a circular cross‐section with a swell ratio of 0.9611.
Non‐darcy forced convective heat transfer in a channel embedded in a non‐newtonian inelastic fluid‐saturated porous medium
Authors: Nakayama A. , Shenoy A. V. 
Published: March 2009

AbstractThe present analysis investigates non‐Darcy forced convective heat transfer in a channel confined by two parallel walls subjected to uniform heat flux in a highly porous medium saturated with a non‐Newtonian power‐law fluid. Extensive numerical integrations have been carried out utilizing the Brinkman‐Forchheimer extension of the Darcy model in order to study the effects of pseudoplasticity, and Brinkman and Forchheimer terms on the heat transfer characteristics.
Extraction of phenols: Ii. distribution data for binary and multicomponent mixtures of phenols, countercurrent extraction performance and model validation
Authors: Bízek V. , Hor áč J. , Koušová M. , Komers R. , Proch ázka J. , Heyberger A. 
Published: March 2009

AbstractThe distribution of binary mixtures of phenol with o‐, m‐ or p‐cresol between aqueous solutions of NaOH and toluene or methyl‐isobutyl‐ketone (MIBK) was investigated. A mathematical model of the distribution was formulated and its parameters were evaluated for each phenol/cresol/solvent combination. The extraction of phenolics from a coal tar fraction with aqueous solutions of sodium phenates was carried out in a countercurrent cascade of four equilibrium stages. The back extraction of phenolics from the aqueous extract was carried out as a triple extraction with pure solvent. A mathematical simulation of the multicomponent, multistage experiments was realized with the DOOM algorithm using an extension of the equilibrium model, formulated for binary mixtures.
Modélisation numérique du transfert de matière dans un écoulement annulaire faiblement tourbillonnaire non‐entretenu
Authors: Legentilhomme P. , Legrand J. 
Published: March 2009

AbstractCe travail est consacré à la modélisation de ľhydrodynamique et du transfert de matière lors de ľécoulement tourbillonnaire laminaire produit par une entrée tangentielle dans un espace annulaire cylindrique. Les équations du mouvement et de diffusion‐convection, simplifiées en utilisant la théorie de la couche limite, sont résolues par une méthode implicite aux différences finies. Bien que cette mèthode ne permette pas de traiter les écoulements fortement tourbillonnaires ou ceux où se produisent des phénomènes de recirculation, ce travail nous a cependant permis de soulever un problème intéressant quant à la validité des hypothèses de la théorie de la couche limite pour la détermination du transfert de matière pour des nombres de Schmidt élevés.
Residence time distribution analysis from a continuous couette flow device around critical taylor number
Authors: Pudjiono P. I. , Tavare N. S. 
Published: March 2009

AbstractThis paper presents an experimental study of residence time distribution (RTD) analysis by pulse response technique in a continuous Couette flow device with rotating inner cylinder and stationary outer cylinder. Two kinds of experimental tests using pulses of tracer dye solution and particles resulting from a fast precipitation were performed in the region near the critical Taylor number characterizing boundary between laminar and laminar vortex flow. For most experiments performed in laminar and laminar vortex flow regime around the critical Taylor number over the ranges 0 < Ta < 120 and 0 < Re < 5.5 the normalized response can be described by a dispersion model. The results of the critical Taylor number as characterized by the minimum dispersion number appear consistent with both theoretical predictions and other empirical observations.
Electrodeposition of catalytically active nickel for the oxygen evolution reaction — effects of anionic composition
Authors: Miao H. J. , Piron D. L. 
Published: March 2009

AbstractNickel electrodes were prepared by electrodeposition in electrolytes of various anionic compositions. The deposition conditions and bath types were evaluated with special emphasis on the electrocatalytic properties for the oxygen evolution reaction (OER). Electrochemical characterizations in a 5 mol/L KOH solution at 25°C showed that the electrode deposited from the chloride bath, having a low Tafel slope of 50 mV/dec and an overpotential of 396 mV at 100 mA/cm2, is the most catalytically active among electrodes prepared in electrolytes of various anionic compositions. The electrode activity for the OER is related to the real surface areas, which depend on the anion compositions in the deposition bath and the deposition conditions.
A cubic simplified perturbed hard‐chain equation of state for fluids with chainlike molecules
Authors: Wang Li‐Sheng , Guo Tian‐Min 
Published: March 2009

AbstractThe simplified version of the perturbed hard‐chain theory (SPHCT) developed by Kim et al. (1986) is modified by reformulating the attractive portion of the canonical partition function for mixtures, and replacing the repulsive portion by a simple simulated expression. The final equation of state developed is cubic in volume. The test results on pure fluids, binary/multi‐component mixtures and reservoir fluids indicate that the CSPHC EOS retains the advantages of the original PHCT, and significant improvements over the SPHCT in predicting the VLE of heavy hydrocarbon‐containing/CO2‐containing mixtures, and liquid phase density are observed.
Performance assessment measures for univariate feedforward/feedback control
Authors: Desborough Lane , Harris Thomas 
Published: March 2009

AbstractAn analysis of variance for univariate feedforward/feedback systems has been derived which allows the variance contributions due to both disturbances and controllers to be established. A performance index which assesses the performance of the overall control scheme has been developed. Estimates of the analysis of variance and performance index can be obtained using ordinary closed loop data and least squares regression. These quantities can be used on‐line or off‐line for either the design of new controllers or as a means of assessing the performance of existing feedforward/feedback control schemes. The practicality of the results in the paper are demonstrated using simulated and industrial data.
Characteristic equations and robust stability of a simplified predictive control algorithm
Authors: Gupta Yash P. 
Published: March 2009

AbstractIn predictive control, control calculations are done such that the difference between the desired and the predicted response of the process is minimized. The number of points on the prediction horizon at which the error is minimized and the number of future control moves considered affect the on‐line computational effort involved in the solution of the constrained optimization problem. Earlier papers have shown that the control performance obtained using the DMC algorithm can also be obtained by using a simplified algorithm where the error is minimized at one point and one future control move is calculated. Because of its computational advantages, the simplified algorithm is analyzed further in this paper. Its transfer function is compared with the transfer function of the DMC algorithm. Characteristic equations to select tuning parameters are presented. The paper also compares the robust stability of the simplified and the DMC algorithms on SISO and MIMO process models. The results provide additional support to the viability of the simplified algorithm and thus indicate that it is possible for some processes to benefit from predictive control with only modest computational resources.
Problem‐oriented modules for process simulation. resolution strategies for simulation and optimization
Authors: Montagna Jorge Marcelo 
Published: March 2009

AbstractA new resolution strategy is presented to overcome short‐comings of the sequential modular process flowsheeting. Following a logic flow of information, different from the material flow of streams in the flowsheet, changes the mathematical structure of the system of equations that models the units. New programs have been generated, very different from traditional modules.Deciding an appropriate resolution strategy usually leads to a dramatic reduction in required CPU times and to an increased flexibility to handle different problems. The simulation convergence and process optimization can be approached from a different perspective.
Carbon monoxide reduction of sodium sulfate mixed with sodium titanate
Authors: Zou X. , Avedesian M. M. , Van heiningen A. R. P. 
Published: March 2009

AbstractThe solid state reduction kinetics by carbon monoxide of sodium sulfate mixed with sodium titanate are studied in a thermogravimetric system at 670‐750°C. It is found that the reduction of this mixture is much faster than that of pure sodium sulfate. The conversion‐time curves of the model mixtures are sigmoidal in shape and well described by the nucleation and growth kinetic model. The activation energy is 420 kJ/mol. The influence of the CO and CO2, concentration, mass fraction of sodium titanate and addition of sodium sulfide catalyst are investigated. Based on the present experiments and literature results, a mechanism is proposed for the CO reduction.
A study of vapour‐liquid equilibria for the binary mixtures hcfc22/cfc114, hcfc22/hcfc142b and hcfc22/hfc152a
Authors: Ström Krister H. U. , Grén Urban B. 
Published: March 2009

AbstractExperimental data for vapour liquid equilibrium for the three non‐azeotropic mixtures HCFC22ICFC114 (CHClFz/CzClzF4), HCFC22IHCFC142b (CHClFz/Cz,/H3ClFz) and HCFC221HFC152a (CHClFz/CzH4Fz) and vapour pressure for the pure components have been measured in pressure range up to 1.8 MPa. In a comparative study the deviations between experimental and calculated data for three correlation methods are presented. The three methods are the equations of state according to Lee‐Kesler (1975) and Carnahan‐Starling‐de Santis (1976) and the activity coefficient model by Wilson (1964).Interaction parameters have been fitted from experimental data to the mixing rules proposed to the two equations of state and the activity coefficient parameters have been determined in the Wilson (1964) model. All three methods studied give good conformity with experimental data for the three mixtures examined.
Separation sequencing. use of information distance
Authors: Iordache Octavian , Corriou Jean‐Pierre , Tondeur Daniel 
Published: March 2009

AbstractA fast process synthesis procedure is developed for generating preliminary separation schemes. The main approach is based on similarity indices obtained from chemical, physical and operating properties between two chemical species in a separation scheme. For the whole set of species, a similarity matrix results. On this basis, algorithms for classifying chemical species and generating separation sequences are developed. A distance between flowsheets is used in order to compare different separation schemes with one another or to some reference cases. The weights of the properties and heuristics are adjusted to account for well‐known optimal cases. Changes in the number of considered separation properties and in their hierarchy are also used to improve the procedure. The algorithm requires very little calculation and can even be implemented by hand in the simplest cases. Extensions of the algorithm include the use of actual values of the separation properties instead of boolean ones and the generation of non‐sharp flowsheets.
Visualization of meso‐ and micro‐mixing status in flow system by high speed stroboscopic microscopic photography
Authors: Chen Jianfeng , Chen Bin , Chen Gantang 
Published: March 2009

AbstractA new visualization technique, the High Speed Stroboscopic Microscopic Photography with spatial resolution of 6.7 m̈m and time resolution of 8 m̈S was developed and first used in this work to visualize the performance of fluid elements in the meso‐ and micro‐mixing processes. From the large amount of pictures taken by this technique, it was found that the fine structure of micro‐fluid‐elements having sizes less than λK looks mainly like slices, especially at higher turbulence in which stochastic elongation and stretching play a dominant role in the deformation of the micro‐elements. Finally, the meso‐ and micro‐mixing processes were ascribed as composed of three consecutive stages: (1) turbulent dispersion, by which the large eddies of sizes larger than λK are dispersed into ones of sizes of λK, (2) stochastic elongation and/or stretching, and (3) molecular diffusion, by which the whole system becomes homogeneous in the molecular scale.
Concentration forcing of isothermal plug‐flow reactors for autocatalytic reactions
Authors: Chidambaram M. 
Published: March 2009

AbstractThe performance of isothermal plug‐flow reactors under feed concentration forcing is analysed for improvement in average yield of product B for a homogeneous autocatalytic reaction, A →k1 A1 →k2 A, →k3 B, where A1 or A2 has an activity influence on the reaction rate constant k1. The performance of the periodically forced reactor with the autocatalytic reaction is compared with that of the corresponding uncatalysed reaction.
Absorption of radiation by substances at “high” concentrations: A new equation and process monitoring applications
Authors: Thatipamala R. , Hill G. A. , Rohani S. 
Published: March 2009

AbstractBeer‐Lambert's law has a wide range of applications, spanning the fields of pure sciences and engineering, and is commonly used for the determination of the concentration of an optically sensitive compound, at “low” concentrations. In this report it is shown that a log‐log expression, log(T/T0) = K log(C/C0), accurately models experimental data (±3%) for four different absorbing species, at “high” concentrations. The dimensionless constant K is shown to be only a characteristic of the absorbing species, and independent of the spectrophotometer/cuvette system used. The new equation is used for on‐line monitoring of dynamic biomass concentration in a continuous bioreactor (CSTBR) for a step change in dilution rate.
Characterization and catalytic gasification of the aqueous by‐product from vacuum pyrolysis of biomass
Authors: Roy C. , Pakdel H. , Zhang H. G. , Elliott D. C. 
Published: March 2009

AbstractSpruce wood residues were treated in a vacuum pyrolysis Process Development Unit with a throughput capacity of 28 kg/h. Two aqueous phase condensate samples with COD concentration varying between 190 and 255 g/L were produced and sequentially extracted with dichloromethane and ethylacetate solvents. The soluble organic matter was composed of acidic, phenolic, alcoholic and ketonic compounds. The insoluble fraction was sequentially distilled at 100 and 110°C under atmospheric pressure. Mainly water was recovered in the first distillate, while the second distillate contained 30.4% formic and acetic acids, 69.4% water and 0.2% residual organic compounds. The distillation residue was rich in oxygen and was essentially insoluble in any organic solvent. The two aqueous phase pyroligneous samples were treated in Bat‐telle's Thermochemical Environmental Energy System (TEESr̀), a registered service mark of Onsite*Ofsite, Inc. of Duarte, California, U.S.A. The results of the tests showed that similar results were obtained with either feedstock. In batch tests a COD reduction of 99% was achieved. The product gas composition was typically about 49% methane, 5% hydrogen, 1 % ethane and 45% carbon dioxide. Tests in a continuous stirred‐tank reactor produced reproducible data which can be used for process scale‐up. Catalyst lifetime was identified as needing further improvement. The preliminary results demonstrated the technical feasibility of the catalytic gasification process as a useful step in the recovery of energy from the secondary condensate stream and the cleanup of the by‐product water from vacuum pyrolysis of wood.
Acid hydrolysis of cellulose. part ii: Stochastic simulation using a monte carlo technique
Authors: Zin‐Eddine Dadach , JOSé‐Henrjque Pinto Q. , Kaliaguine Serge 
Published: March 2009

AbstractA Monte Carlo procedure was developed to simulate cellulose acid hydrolysis at high temperatures. Both the kinetic information related to the model compound cellobiose and the morphological aspect of cellulose including crystalline, semi‐amorphous and amorphous zones were estimated from experimental data and introduced in a FORTRAN program. In our model of cellulose acid hydrolysis, the cleavage of a glycosidic bond and the degradation of glucose are considered as two irreversible reactions in series. For all the temperatures, the overall glucose disappearance rate constant used in our model, was higher than the experimental constant obtained from the degradation of pure glucose. The changes related to the effects of milling on the cellulose acid hydrolysis were successfully considered in the procedure. Finally, the observed good agreement between the simulated and the experimental data of glucose yield versus time proved that Monte Carlo simulation associated with a Markov chain is a flexible connection between cellobiose (model compound) and cellulose conversion reactions.
Calculation of excess molar volumes with different cubic equations of state and different mixing rules
Authors: Djordjević Bojan D. , Šerbanovlć Slobodan P. , Grozdanić Dušan K. 
Published: March 2009

AbstractThe effects of the simple composition‐dependent combining rules (conventional, Adachi‐Sugie and van Laar‐Stryjek‐Vera‐type) and Huron‐Vidal‐NRTL mixing rules and different cubic equations of state (Redlich‐Kwong, Soave‐Redlich‐Kwong, Peng‐Robinson and Peng‐Robinson‐Stryjek‐Vera) on excess molar volume correlation are examined. The results obtained for some asymmetric non‐ideal mixtures indicate very good agreement between correlated and experimental data in all cases when Huron‐Vidal‐NRTL mixing rules are coupled with the Peng‐Robinson‐Stryjek‐Vera equation of state.