bluuebunny/crossref_metadata_2025_split huggingface dataset:
Generalized dehydration models for n‐Aliphatic monohydric alcohols
Authors: Abhyankar S. M. , Doraiswamy L. K. 
Published: March 2009

AbstractThe kinetics of dehydration of n‐aliphatic monohydric alcohols (viz. ethyl, n‐butyl, n‐hexyl and n‐octyl) has been studied over Indian bauxite as catalyst in the temperature range 300–375°C. Modified Hougen‐Watson models for all the four reactions occurring have been proposed, and the rate and adsorption constants have been estimated by the method of linear least squares, and confirmed by nonlinear analysis. Generalized correlations for predicting the rate constants on the basis of change in the entropy of activation have been developed. Similarly, correlations have also been developed for each of the adsorption constants as a function of the binding energy of the alcohol molecule involved.
Vapor‐liquid equilibria for the ternary system n‐Heptane/n‐Propanol/l‐Chlorobutane and its constituent binaries at 298.15 K
Authors: Sayegh S. G. , Vera J. H. , Ratcliff G. A. 
Published: March 2009

AbstractVapor‐liquid equilibrium data for the ternary system n‐heptane/n‐propanol/1‐chlorobutane and its constituent binaries at 298.15 K are reported. Data for the binary systems have been correlated using the Wilson, LCG, LSG and UNIQUAC expressions for the activity coefficients. Predictions for the ternary system with all four expressions have been compared with the experimental data. The Wilson and the LCG equations perform similarly, giving the best correlations for the binary systems containing propanol and the best predictions for the ternary system.
Evaluation of capital cost data: Offsite utilities (Supply)
Authors: Woods Donald R. , Anderson Susan J. , Norman Suzanne L. 
Published: March 2009

AbstractCapital cost correlations are given for units supplying utilities: steam, refrigeration, cooling and treated water, electricity. Correlations available in the literature and current data are compared on a consistent basis. Thirty‐two graphs show the relative magnitudes of the different correlations, and the recommended correlation for each type of equipment is given. Some factors are given on the costs of installing the package units.
Fundamental studies of foam fractionation of cadmium: Effect of the addition of monovalent ions on surface excess of cadmium
Authors: Kubota K. , Hayashi S. , Takubo Y. 
Published: March 2009

AbstractThe effects of Sodium, Cadmium and Hydrogen ions on the surface excess of the collector, Dodecylbenzenesulfonic group, DBS”, were examined using an elaborated Langmuir correlation. Gouy‐Chapman's electrical diffuse layer model for estimating the cations, colligend ions, Cadmium and Sodium ions, to be concentrated on a bubble surface was found to be applicable for the aqueous CdCl2‐DBSNa, Cd(NO3)2‐HNC2‐DBSNa and CdCl2‐HCl‐DBSNa solution systems. The behaviour of Sodium ion in the diffuse layer and the selective adsorption coefficient for the solution system containing Cadmium and Sodium ions was also studied, showing a preferential adsorption of divalent ion in the diffuse layer.
The oxidation of ethylene over a supported platinum catalyst
Authors: Hawkins James R. , Wanke Sieghard E. 
Published: March 2009

AbstractThe complete oxidation of ethylene over a 0.3% Pt/Al2O3 catalyst, at ethylene concentration of ≤ 1.0 mol/m3 and oxygen concentrations of 0.16 to 8.6 mol/m3, was studied in a recycle reactor at temperatures of 362 to 472 K. The activity of the catalyst was influenced by pretreatment and reaction conditions causing fluctuations in rate measurements. Nevertheless, a simple rate function, r =Ae−E/RT[O2]/[C2H4], fitted the data as well as more complicated rate functions.
Déformation et oscillation des gouttes en présence d'agents tensio‐actifs
Authors: Mekasut L. , Molinier J. , Angelino H. 
Published: March 2009

AbstractA study was made of the fall of a single drop of carbon tetrachloride through pure or contaminated water. Results are presented for the variations of the shape of the drop and of the frequency of oscillation with diameter and Teepol concentration. It has been found that presence of surface active agents, increases the deformation of drops but reduces the frequency of oscillations. The comparison between these experimental data and several relations has shown that no previous correlations of either the eccentricity or the frequency of oscillation are satisfactory when the system is contaminated by some surfactants.
Rates of gas absorption with interfacial turbulence caused by micro‐stirrers
Authors: Sada Eizo , Katoh Shigeo , Yoshii Hwehumi , Ban Yuji 
Published: March 2009

AbstractRates of absorption of CO2 into water, a 0.2 mol/L NaOH solution and a 40 wt% glycerol solution with and without the interfacial turbulence caused by micro‐stirrers, made of a magnetic material, were measured with use of a stirred vessel with known gas‐liquid interfacial area. The effect of the interfacial turbulence on the rate of gas absorption was remarkable in the lower range of the bulk turbulence. The enhancement factors due to the interfacial turbulence were calculated with use of the age distribution function of the Danckwerts type and they agreed well with the experimental results.
Modèles cinétiques et mécanisme de l'oxydation catalytique. Du propene en présence de molybdate de fer
Authors: Forissier M. , Gros J. B. , Pralus C. 
Published: March 2009

AbstractThe kinetic study of propylene oxidation to acrolein over a ferric molybdate catalyst has been performed on a differential reactor. Among models derived on the assumptions of Langmuir Hinshelwood kinetic rate or on Mars and Van Krevelen oxido‐reduction mechanism, a discrimination method has been realized. The discrimination leads on one hand to the conclusion that acrolein is obtained either from oxygen of the oxide lattice or from absorbed dissociated oxygen. On the other hand carbon dioxide is formed both by acrolein degradation and by a mechanism excluding dissociation of oxygen.
Macro‐encapsulation I. Production of composite drops
Authors: Aboul‐Nasr Osman T. , Huang Robert Y. M. 
Published: March 2009

AbstractA method for the production of concentric drops is presented in detail. The apparatus consists of two coaxial nozzles at the bottom of a column, and the necessary pumping equipment. Two immiscible liquids arc pumped individually through the nozzles. The resultant drop is allowed to rise through a column of liquid immiscible with the outer drop.Details of the experimental procedures and results are presented. A theoretical model describing the behaviour of the system, based on the hydrodynamics of drop formation, is developed.The production of composite drops can be applied to many products, for example: sustained delivery of drugs and time‐release fertilizer.
Hydrocracking athabasca bitumen with alkali metal promoted CoO‐Mo03‐A12O3 catalysts
Authors: Kelly James F. , Ternan Marten 
Published: March 2009

AbstractAlkali metal promoters (lithium, sodium and potassium) were added to catalysts used to hydrocrack Athabasca bitumen, in order to decrease the coke deposition which causes catalyst deactivation. Sodium and potassium promoters decreased the catalyst coke content, the catalyst surface area, and the pitch, oxygen, sulphur and nitrogen conversions. On a unit surface area basis, the sodium and potassium promoters increased the pitch and oxygen removal reaction rates. For all the lithium promoted catalysts both conversion and pitch, oxygen, sulphur and nitrogen removals on a unit surface area basis exhibited a maximum. Sulphur and nitrogen removal decreased with increasing potassium content. The results are explained in terms of the changes in catalyst electronic properties caused by the addition of the promoters.
A novel magnetoelectrolytic reactor
Authors: Ismail M. I. , Fahidy T. Z. 
Published: March 2009

AbstractThe characteristics of mass transport and cathode deposit in a pilot‐plant size magnetoelectrolytic reactor employing an anisotropic inhomogencous magnetic field are analyzed. It is shown that the behaviour of the reactor, especially the deposition pattern, is strongly linked to the distribution of the magnetic flux density.
Numerical and experimental study of a falling liquid column
Authors: Hill G. A. , Chenier C. L. , Shook C. A. , Esmail M. N. 
Published: March 2009

AbstractThe collapsing liquid column phenomenon has been experimentally and theoretically studied. The experimental data demonstrated the development and travel of a shock wave. Point velocities within the flow regime were measured using a hot film probe. The numerical simulation was performed using a finite difference code similar to the Marker and Cell technique. The results were in good agreement with the experimental data. The numerical technique therefore promises to be a valuable aid in studying highly convective, incompressible flows.
Measurements of interfacial areas in cocurrent gas—liquid downward flow
Authors: Vavruska J. S. , Perona J. J. 
Published: March 2009

AbstractGas‐liquid interfacial areas were measured for cocurrent downward flow of the two‐phase mixtures in a 2.54 cm ID open tube. The liquid phase was a dilute solution of aqueous sodium hydroxide and the gas phase was a mixture of air and carbon dioxide. Interfacial areas were determined by sampling the liquid phase and applying the technique of absorption with fast chemical reaction. Data were obtained in the froth flow regime and in the falling bubbly film regime which does not occur in horizontal or vertical upflow. Measured interfacial areas ranged from 0.7 to 2.5 cm−1. These values are lower than those for downflow in a 10‐mm tube(10) by a factor of about two, suggesting a dependence on the tube diameter. A correlation in terms of Jepsen's frictional energy dissipation parameter \documentclass{article}\pagestyle{empty}\begin{document}$ \left( {\frac{{\Delta P}} {{\Delta L}}} \right)(V_L ^ \circ + V_G ^ \circ ) $\end{document} is presented for the interfacial area.
Energy balance for a DC plasma torch
Authors: Bokari Azhar , Boulos Maher 
Published: March 2009

AbstractA study was made of the energy utilization efficiency in a d.c. plasma toich operating with argon at atmospheric pressure at a power level of 10‐25 kW. Calorimetric measurements of the energy lost to the cathode, anode and that remaining in the plasma jet showed that the torch efficiency was about 40 to 50%. It increases with an increase of the plasma gas flow rate but decreases with an increase of the current intensity. The electrode spacing was found to have no significant influence on the efficiency over the range investigated. The torch efficiency could be substantially improved by a reduction of the anode size. The addition of small concentrations of a diatomic gas such as nitrogen improved the efficiency to about 65% and increased the total power dissipated in the torch.
Isothermal column sorption of ethylene—carbon dioxide mixtures with azeotropic behaviour
Authors: Basmadjian D. , Hsieh S. T. 
Published: March 2009

AbstractIsothermal breakthrough curves were determined for ethylene‐carbon dioxide mixtures in nitrogen fed to a bed of Linde 5A 1/8″ molecular sieve pellets. The system had previously been shown(11) to have azeotropic equilibrium compositions in the range − 50 to + 50°C and at a total solute pressure of 1.07 kPa. The present column experiments covered the range −15 to + 50°C and total solute pressures of 0.40 ‐ 2.67 kPa. Three major types of adsorption breakthrough curves were observed. In two of these the solutes broke through simultaneously and could not be separated by extending the bed length. Carbon dioxide exceeded and then dropped back to the feed concentration in some of these runs, in others the inlet value was reached directly. In the third type of curve, the sorption fronts did separate, but the light component did not always exceed the feed concentration in the classical manner of a Langmuir solute. A tentative explanation of these phenomena is given in terms of equilibrium theory.
Activated carbon adsorption treatment of spent pickle brine
Authors: Ratnani Kebir , Leduy Anh , Ramalho Rubens S. 
Published: March 2009

AbstractA continuous process for recovery of spent pickle brine (SPB) by preliminary filtration on a sand bed to remove suspended solids, followed by adsorption treatment in an activated carbon column to remove color and odor‐causing organic compounds is investigated. Batch isotherm adsorption experiments revealed that the adsorption capacity of the SPB‐activated carbon system is relatively insensitive to temperature variation (about 15% drop for a temperature rise from 0 to 40°C), but quite sensitive to the effect of dilution (about 25% lower for 90% SPB solution). Regenerated activated carbon behaved similarly to fresh carbon with only slightly lowered adsorption capacity. It is estimated that a low capital investment of 0.08 cent per liter of recycled treated SPB is required for a plant with a 190 000 L/d capacity. This cost is much lower than that of fresh salt, and thus will be defrayed by savings on recycled salt.
Cristallisation du trihydrate d'alumine: Effet des conditions d'agitation
Authors: Remillard Michel , Cloutier Leonce , Methot J. Claude 
Published: March 2009

AbstractLa cristallisation du trihydrate d'alumine a été étudiée pour différents niveaux d'agitation dans un réacteur isotherme fonctionnant en régime discontinu. Les essais expérimentaux ont permis de relier aux conditions d'agitation les constantes cinétiques de trois phénomènes se produisant lors de la cristallisation de l'alumine. Finalement, des calculs de simulation ont permis de noter qune importante amélioration de la précision sur les granulométries est obtenue en ajoutant les modèles d'agglomération et d'attrition au modèle déjà connu de croissance.
Unsteady stagnation point heat transfer in non‐newtonian fluids
Authors: Gorla Rama Subba Reddy 
Published: March 2009

AbstractThe transient thermal response of a power law type non‐Newtonian, laminar boundary layer at a two‐dimensional stagnation point is investigated. Consideration is given to the case of a step change in surface temperature. The transient heat flux and details of the temperature field are obtained and have been presented graphically. The range of Prandtl numbers investigated is from 5 to 1000 while the viscosity index was allowed to vary from 0.1 to 5.0.
Laminar natural convection over a slender vertical frustum of a cone with variable surface temperature
Authors: Chiou J. P. , Na T. Y. 
Published: March 2009

AbstractThe problem of laminar, natural convection flow over a slender frustum of a cone with variable surface temperature is treated in this paper. The governing differential equations are solved by a combination of quasilinearization and finite‐difference methods. As an illustration of the formulation, numerical solutions are obtained for a range of Prandtl numbers (0.1 to 100) and the transverse curvature parameter for the case of power‐law surface temperature distribution. The formulation presented in this paper provides a way to analyze the heat transfer over a slender frustum of a cone where both the transverse curvature and the surface temperature variation have to be considered simultaneously.
Gas‐Liquid reactions in packed beds: Regimes of reaction in the static hold‐up
Authors: Patwardhan V. S. 
Published: March 2009

AbstractThe interfacial area in a packed bed may be divided into two parts, i.e. the interracial area corresponding to the dynamic hold up, and that corresponding to the static hold up. Although both these parts contribute towards gas absorption, the effectiveness of the interfacial area of the static hold up in a packed bed for gas absorption with a chemical reaction can become quite low (which leads to a reduction in the effective interfacial area) if there is a significant depletion of the liquid phase reactant in the static hold up. If this depletion is severe enough, then the chemical reaction in the static hold up may fall into the slow reaction regime, i.e. unreacted gas phase component may exist in the bulk of the static hold up. In this paper, a general procedure is developed for calculating the effective interfacial area in a packed bed which is applicable for all possible reaction regimes that may exist in the static hold up. An approximation is proposed for cases involving the slow reaction regime in the static hold up. This approximation is applicable to reactions with any form of kinetics. It is shown to predict the effective interfacial area with sufficient accuracy in the case of a second order reaction.
Statistical study on the batch conversion of estevan lignite into oils using carbon monoxide and hydrogen mixtures
Authors: Fonseca R. , Chornet E. , Roy C. , Grandbois M. , Kelly James F. 
Published: March 2009

AbstractBatch autoclave hydrogenolysis of a Saskatchewan lignite has been conducted with CO and H2 mixtures. Conversion, oil yield and the carbon monoxide consumption patterns were measured as a function of reaction temperature (380 — 460°C), initial cold pressure (7.1 — 11.1 MPa), contact time (10 — 50 min), and initial CO/H2 gas composition (1/3 — 3/1 vol. %). The experimental results were obtained following an unreplicated 24 factorial design. Significant models were derived for conversion and the CO consumption patterns. A relationship seems to develop between carbon monoxide consumption and the amount of oil produced. The oil yield model however showed a lack‐of‐fit at the F5% level. The highest conversion and oil yield experimentally obtained were 85.3 and 63.4% respectively, on the lignite m.a.f. basis. In general greater hydrogenation but less deoxygenation occurred at the lower temperature.
Mass transfer rates between oil slicks and water
Authors: Cohen Yoram , Mackay Donald , Shiu Wan Ying 
Published: March 2009

AbstractThe results of a laboratory wind‐wave tank study are reported in which the rate of mass transfer of a tracer (phenol) from a synthetic oil slick to the underlying water was measured at wind speeds from 0 to 9 m/s. Estimates were made of the mass transfer coefficients in the oil and water phases at the oil‐water interface. The results indicate that the rate of hydrocarbon dissolution from a slick is controlled by the water phase mass transfer coefficient which is usually less than 1 cm/h. Whereas mass transfer coefficients at air‐water interfaces show a marked increase at wind speeds of approximately 3 m/s due to wave formation, when oil is present its damping effect delays this transition to approximately 7 m/s. It can be inferred that (i) dissolution is considerably slower than evaporation for reasonably volatile compounds, (ii) dissolution will have a negligible effect on slick composition, (iii) the concentrations of soluble hydrocarbons established in the water column under the slick by direct dissolution are small and unlikely to result in significant toxicity, and (iv) that the dominant mechanism of transfer of soluble hydrocarbons into the water column is probably from dissolution of dispersed oil particles.
Study of chromia alumia catalysts
Authors: Mathur Indresh , Bakhshi Narendran N. , Mathews Joseph F. 
Published: March 2009

AbstractThe purpose of this study was to investigate the effect of increasing chromium concentration on the activity and physical properties of chromia/alumina catalysts. The catalysts were prepared by impregnating η‐alumina support in various concentrations of chromic acid solution and were finally calcined in air.A variety of physical‐chemical properties of the catalysts were studied. These included BET surface area, pore volume, metal concentration, x‐ray diffraction studies, oxidation states using EPR, surface oxidation (excess oxygen) measurement by iodometric titration, metal area measurement and crystallite size determination. Decomposition of hydrogen peroxide was used to determine the activity of various catalysts.A correlation of catalytic activity with crystallite size indicated that both, activity per unit chromia area and activity per g of catalyst were maximum at a crystallite size of 3.7 mm. Also, the activity per unit chromia area is maximum when chromia is deposited 3‐4 layers thick.In contradiction to the view put forth in the literature, this study indicates (on the basis of excess oxygen and chemisorption measurement) that not only is all of the top chromium oxidized to Cr6 but that the oxidation also takes place in the sub‐surface layer(s).
Statistical identification of a reaction network using an integral plug flow reactor
Authors: Mclean David D. , Bacon David W. , Downie John 
Published: March 2009

AbstractStatistical multiresponse techniques for the design and analysis of experiments were used in conjunction with an integral isothermal staged tubular reactor to identify the reaction network for the oxidation of o‐xylene over a V2O3/K2SO4/silica catalyst. Following a five stage strategy a precise quantitative description of the reaction network in terms of the multiresponse form of the steady state adsorption model was obtained. The use of mixed feeds was found to improve the precision of rate parameters associated with later steps in the reaction network and also to reduce correlations among estimates of the rate parameters.
The nature of the active sites in the reactions of cumene on HY and LaY catalysts
Authors: Corma A. , Wojciechowski B. W. 
Published: March 2009

AbstractThe secondary reactions which accompany cumene cracking have been studied at 360°, 430°, 500°C, over an HY zeolite catalyst using a tubular packed bed reactor. The concept of “Optimum Performance Envelope” was used in order to identify which of the observed reaction products are primary and which are secondary. In this way, benzene, ethylbenzene, n‐propylbenzene, cymene, m‐ and p‐diisopropylbenzene, as well as propylene, i‐butene, and butene have been found to be primary products, while methane, ethylene, ethane, toluene, ethyl toluene, and i‐ and n‐butane are identified as secondary products.The initial selectivities for the primary products have been calculated, and from these, the initial kinetic rate constants. These values, as well as the activation energies of primary product formation, are compared with those obtained using a LaY zeolite catalyst. The observed differences are discussed in terms of the nature and number of the active sites on the catalyst and lead us to conclude tthat LaY and HY have identical active sites but differ in site concentration.
Velocities of entrainment in liquid fluidized beds of mixed solids
Authors: Vaid R. P. , Gupta P. Sen 
Published: March 2009

AbstractExperimental data are reported on velocities of entrainment in liquid fluidized beds. Single as well as multicomponent mixtures of solids varying in size and/or density have been investigated. By drawing an analogy with partially fluidized bed systems, phase equilibrium diagrams of binary and ternary mixtures have been constructed and presented. Correlations have been developed for the prediction of velocities related to the beginning of entrainment, minimum entrainment and complete entrainment.
Anodic oxidation of phenol for waste water treatment
Authors: de Sucre V. Smith , Watkinson A. P. 
Published: March 2009

AbstractThe electrochemical oxidation of phenol for waste water treatment applications was investigated on lead dioxide packed‐bed anodes. Cells were operated in both batch and continuous modes with feed streams up to 1100 nig/1 phenol dissolved in aqueous solutions of Na2SO4 and H2SO4 or NaOH. All the phenol in solution could be readily oxidized but complete total organic carbon (T.O.C.) removal was more difficult. The percent phenol oxidized increased with increasing current density, and decreased as initial phenol concentration, electrolyte flow rate, pH and anode particle size were increased. Results are compared to simple mathematical models.