bluuebunny/crossref_metadata_2025_split huggingface dataset:
Use of sewage sludge for manufacturing adsorbents
Authors: Chiang P. C. , You J. H. 
Published: March 2009

AbstractThis paper demonstrates that digested sludge can be reclaimed as an adsorbent for the removal of organic vapors (MEK, TOL and TCE) through the use of a pyrolysis. The manufactured adsorbent products were characterized by Brunauer, Emmentt and Teller (BET) surface area, carbon tetrachloride activity (ANSI/ASIM D3467–76'), and an elemental analysis test. Both the determination of CCl4 activity and BET surface area were regarded as the useful means for estimation of the adsorption capacity of organic vapors on the reclaimed adsorbents.From the view point of specific surface area (CCl4 activity number or adsorption capacity), it was concluded that the optimum condition for manufacturing the reclaimed adsorbent was by adding 5 kmols/m3 ZnCl2 to the treated sludge and then heating the mixture at 550°C for 1 hour.
Ventilation of a dead‐end duct having a porous barrier
Authors: Ryan J. T. , Griffin Wayne H. 
Published: March 2009

AbstractAnalytic expressions for the flow and pressure in a dead‐end duct which has loss of fluid through a porous wall are developed. The presence of an obstruction or auxiliary fan at the end of the duct is included. In either case there is a maximum permissible length of duct. As the duct length approaches this maximum, the main supply fan power and flow increase dramatically.There is no recirculation within the duct when there is an obstruction at the end of the duct. If an auxiliary fan is used, there is always recirculation. However the use of an auxiliary fan can yield major savings in total power requirements.
Influence of operating conditions on particulate fouling
Authors: Müller‐Steinhagen H. , Reif F. , Epstein N. , Watkinson A. P. 
Published: March 2009

AbstractThe influence of flow velocity and particle size on the deposition of suspended alumina particles onto heat transfer surfaces was measured with two fouling probes, namely, a heated cylindrical rod in an annulus and a coiled wire in crossflow. Additionally, the response of the fouled probes to such changes as may occur in operating heat exchangers was investigated. The measured influence of flow velocity, wall temperature, bulk temperature, heat flux, particle concentration and particle size on the fouling behaviour as described in this paper and in a companion paper is compared to the predictions of several fouling models from the literature, and recommendations are made for further improvement of these models.
Cinétique de dégagement des matières volatiles lors de la pyrolyse d'électrodes de carbone industrielles
Authors: Tremblay FrançLois , Charette Andre 
Published: March 2009

AbstractDans un complexe de fabrication d'aluminium, le procédé de cuisson des anodes donne lieu à une libération importante de matières volatiles combustibles. Le présent travail vise à mieux comprendre la cinétique de dégagement de ces substances. À cette fin, un dispositif thermogravimétrique de grandes dimensions a été mis au point de façon à pouvoir simuler le mieux possible l'environnement industriel. Des échantillons de deux masses distinctes ont été soumis à la pyrolyse à différents régimes de chauffage. La perte de poids et les concentrations des gaz dégagés ont été enregistrées tout au long de la montée en température. Les résultats cinétiques sont rapportés pour le méthane, l'hydrogène et le goudron. L'ordre de réaction ne varie pas avec la vitesse de chauffage alors que l'énergie d'activation et le facteur pré‐exponentiel augmentent. De plus, pour les grosseurs d'échantillons étudiés, il a été trouvé que la masse du solide n'influence pas la valeur des paramètres cinétiques.
Liquid‐liquid equilibria of the system water + acetic acid + methyl propyl ketone
Authors: Bianco A. , Correa J. M. , Arce A. , Correa A. 
Published: March 2009

AbstractThis article reports equilibrium data for the binary liquid‐liquid system water + methyl propyl ketone at temperatures in the range 20‐55°C, together with solubilities and equilibrium compositions of the ternary system water + acetic acid + methyl propyl ketone at 25, 35, 45 and 55°C. NRTL and UNIQUAC equations have been fitted to the experimental data for the ternary system, which are likewise compared with the values predicted by the group contribution method UNIFAC.
Determination and correlation of axial‐mixing parameters in an agitated liquid‐liquid extraction column
Authors: Steiner Ladislav , Kumar Anil , Hartland Stanley 
Published: March 2009

AbstractDispersion coefficients were measured in a pilot‐plant sized agitated liquid‐liquid extraction column of the Kuhni type. Available techniques were considered, and the axial mixing in both phases obtained over a broad range of operating conditions, both with and without mass transfer and with two sets of stator plates. Earlier correlations for backmixing in the continuous phase were checked and improved, the final equation being successfully tested on available published data.
Hydrocracking of n‐heptane with a NiO‐MoO3/HYUS zeolite as catalyst. Kinetic study
Authors: Vázquez M. I. , Escardino A. , Aucejo A. 
Published: March 2009

AbstractThe hydrocracking of n‐heptane has been carried out in a fixed bed reactor at 2.45 MPa pressure and with a H2/n‐heptane molar ratio of 5.0 using a 4 wt% NiO ‐ 8 wt% MO3/HYUS zeolite as a catalyst. The W/F10 ratio was varied between 75.3 and 1624 kg · s/kmol at different reaction temperatures: 573, 588, 603 and 623 K.The kinetics of the reaction has been studied by two different procedures due to the slight deactivation of the catalyst. One of them uses the conversion and yield values extrapolated at time on stream to zero and the other uses a kinetic equation where the deactivation of the catalyst has been included. The experimental data were fit well by a pseudo‐first order kinetic equation and the kinetic constant values obtained by both methods coincide. The apparent activation energy of the reaction has a value of 105.8 + 5.0 kJ/mol.
Gas holdup in a two‐phase vertical tubular reactor at high pressure
Authors: De Bruijn T. J. W. , Chase J. D. , Dawson W. H. 
Published: March 2009

AbstractGas holdup in a tubular reactor was measured at pressures from 5 to 14 MPa at 300°C using a differential pressure cell. The effects on gas holdup of gas density, liquid superficial velocity and gas superficial velocity were studied using vacuum tower bottoms from a Venezuelan feedstock with 95.1 wt% +524°C material. Hydrogen was used at superficial gas velocities from 0.7 to 2.0 cm/s.The feed density at 15°C (0.1 MPa), 300°C (5.57 MPa) and 400°C (13.9 MPa) was measured and showed a linear decrease with temperature. Increased gas density at a constant temperature of 300°C increased the gas holdup at all superficial gas velocities. An increase in the liquid flow rate from about 0.04 to 0.1 cm/s did not affect the gas holdup.
Performance of packings for water distillation
Authors: Chuang K. T. , Miller A. I. 
Published: March 2009

AbstractDistillation of water has been investigated in packed columns of 300, 500 and 750 mm diameter. Both ordered packings (Goodloe, Mellapak and Sulzer CY) and random packings (Hy‐Pak, Mini‐ring and Pall‐ring) were studied and performance compared. It was found that, with surface treatments, phosphor bronze packings show good performance and insignificant scale‐up factors. Plastic materials are not suitable for water distillation because of their poor wetting characteristics.
Kinetics of reactions involved in pvrolvsis of cellulose II. The modified kilzer‐bioid model
Authors: Agrawal Ravindra K. 
Published: March 2009

AbstractAt temperatures below 300°C, it has been shown that the pyrolysis of cellulose can be modeled in terms of a modified Kilzer‐Broido ((K‐B) Model. According to this model, cellulose decomposes via two competitive reactions, a dehydration reaction to form anhydrocellulose and a depolymerization reaction to form levoglucosan. Anhydrocellulose later decomposes to chars and gaseous products via two competitive reactions. Arrhenius parameters and a technique of estimating empirical constants from experimental data for the K‐B type reactions are presented. Comparison of the ability of the modified K‐B model and the three reaction model to predict weight loss, product yields and heat pretreated results are also made.
A method for the design of flexible distillation sequence
Authors: Wagler R. M. , Douglas P. L. 
Published: March 2009

AbstractA simple method has been developed to optimally design a distillation sequence with a fixed degree of flexibility in feed composition and flowrate, and accounts for uncertainty in stage efficiency, K‐value and beat transfer coefficient calculations. The method minimizes a weighted cost function and ensures both optimal and feasible operation in the range of flexibility/uncertainty by using an approach termed “practical feasibility”. The method was tested on a 4 column distillation sequence separating a 5 component light alkane feed mixture. Results are presented to illustrate the effect of uncertainty on sequence cost and column overdesign.
Correlation and prediction of gas solubility in cold lake bitumen
Authors: Mehrotra Anil K. , Svrcek William Y. 
Published: March 2009

AbstractThe solubility data for pure light gases, namely N2, CH4, CO2 and C2H6, in Cold Lake bitumen are correlated by use of the Peng‐Robinson equation of state. Modeling Cold Lake bitumen as a mixture of three pseudocomponents adequately matched two sets of the gas‐solubility data. The critical properties and acentric factor for the bitumen pseudocomponents were estimated using the Kesler‐Lee correlations. For each gas‐bitumen pair, a single constant value of the binary interaction parameter is shown to predict the gas‐solubility data with average deviations ranging from 2 to 8%. Subsequently, these calculations were extended to predict the solubility of CO2+CH4 gas‐mixtures in Cold Lake bitumen. It is shown that the solubility predictions for the gas mixtures data are higher by approximately 6 to 9%.
Correlations for wall and particle shape effects on fixed bed bulk voidage
Authors: Dixon Anthony G. 
Published: March 2009

AbstractCorrelations have been derived, by both geometrical arguments and empirical treatment of data, for the bulk void fraction in a fixed bed. The void fraction has been correlated as a function of particle‐to‐tube diameter ratio for packings of spheres and equilateral solid cylinders. Prediction of void fraction for equilateral hollow cylinders can be made from the solid cylinder correlation, provided a correction factor is included that allows for internal voidage and interpenetration of packings.
Jet penetration and pressure drops in water spouted beds of fine particles
Authors: Morgan M. H. , Littman H. , Sastri B. 
Published: March 2009

AbstractNew expressions for the maximum spoutable height and spout pressure drop ratio are developed for fine particles spouted in water. The maximum spoutable height in both water and air systems is found to be dependent upon two dimensionless parameters, β and ALim. For fine particles spouted with water, the dimensionless pressure drop ratio depends only upon the voidage, ϵ at the bottom of the spout.
Experimental study of a new mechanically resistant adsorbent
Authors: Iovtchev K. , Nikolov L. , Elenkov D. 
Published: March 2009

AbstractA new mechanically resistant adsorbent for SO2, removal from tail gases has been developed based on a solid porous support. The effect of the gas mixture composition on the dynamics of sulphur dioxide adsorption on this new adsorbent has been studied.The results show that the behaviour of the new adsorbent, used in a fixed bed adsorption, is similar to that of classical carbon‐containing adsorbents. The values of mass transfer coefficients have been calculated for different experimental data. The breakpoint time can be determined from the solution of the differential equations of the system.
Characterization of dilute and dense phase vertical upflow gas‐solid transport based on average concentration and velocity data
Authors: Mok S. L. K. , Bergougnou M. A. , Molodtsof Y. , Large J.‐F. 
Published: March 2009

AbstractDilute, ‘dense phase 1’, and possibly a third regime‐‘dense phase 2’, were observed in a vertical 0.02 m diameter pneumatic conveyor using 210 μm sand particles. The transitions were marked by the alterations in the trend of the measured average solids hold‐up while varying the solids mass flowrate at constant air velocity. Hydrodynamic characteristics together with the transition criteria for the various transport modes were established. A novel regime diagram based on average gas velocities and solids mass flowrates was developed to identify the operating conditions for these regimes, as well as the limiting solids carrying capacities of the present conveyor. A probable cause of the dilute to dense phase transition is speculated upon.
Kinetic analysis of the liquid phase hydrogenation of 2‐ethyl‐hexenal in the presence of supported Ni, Pd and Ni‐S catalysts
Authors: Smedler Gudmund 
Published: March 2009

AbstractThe kinetics of the consecutive hydrogenation reactions 2‐ethyl‐hexenal → 2‐ethyl‐hexanal → 2‐ethyl‐hexanol were studied in the liquid phase in presence of commercial Ni, Pd and Ni‐S catalysts. The Pd and Ni‐S catalysts were extremely selective with respect to the formation of 2‐ethyl‐hexanal, while the full reaction sequence was readily catalyzed by nickel.A Langmuir‐Hinshelwood model with dissociative hydrogen adsorption was found to be the most probable model, for all three catalysts. The proposal of dissociative hydrogen adsorption of the Ni‐S catalyst was supported by an independent gas‐phase experiment, using the H2/D2 exchange reaction as a model reaction for the hydrogen àdsorption process.
PRSV: The stryjek‐vera modification of the peng‐robinson equation of state. Parameters for other pure compounds of industrial interest
Authors: Proust P. , Vera J. H. 
Published: March 2009

AbstractPure ‐ compound ‐ parameters for the Stryjek‐Vera modification of the Peng‐Robinson equation of state, PRSV, are reported for sixty‐nine additional compounds of industrial interest. Errors in the reproduction of pure compound vapor pressure are normally below 1% at reduced temperatures lower than 0.7 At reduced temperatures higher than 0.7, for a few compounds for which data are scarce, errors are somewhat higher than 1%.
Pneumatic transport of solids in an inclined geometry
Authors: Klinzing G. E. , Rohatgi N. D. , Myler C. A. , Dhodapkar S. , Zaltash A. , Mathur M. P. 
Published: March 2009

AbstractFlow studies were conducted in 0.0266‐m and 0.0504‐m glass pipes held at various angles of inclination. Measurements in these experimental setups included particle velocities, solid mass flow rates, and pressure drops in both the upper and the lower halves of the pipe. Visual observations of the flow patterns were made through the glass section. Particles used in this system included glass particles of 67‐, 450‐, and 900‐μm diameter, as well as iron oxide of 400‐μm diameter. Mass flows from the two halves of the pipe were obtained by splitting the flow with a knife‐edged separator. Experiments were also performed in a 0.0095‐m transfer line in an inclined loop. The angle of inclination of the test loop was varied from 0 to 90 degrees from the horizontal. The effect of angle of loop inclination, tube diameter, and particle characteristics on basic flow parameters were studied.
Hydrodynamics of three‐phase fluidized bed containing cylindrical hydrotreating catalysts
Authors: Song Gyung‐Ho , Bavarian Farshad , Fan Hang‐Shih , Buttke Robert D. , Peck Lawrence B. 
Published: March 2009

AbstractExperiments were performed to study the hydrodynamic characteristics of a cocurrent, gas‐liquid‐solid fluidized bed containing cylindrical hydrotreating catalysts under conditions of high gas holdup. These conditions were established using an aqueous t‐pentanol (0.5 wt. %) solution as the liquid phase in an attempt to simulate reaction conditions for hydrotreating of residual oils and coal liquefaction. Separate three‐phase experiments were performed with air and water to investigate the effect of surface tension on hydrodynamic behavior.A mathematical model was developed to describe the minimum fluidization velocity behavior. Bed voidage, gas holdup and terminal velocity of the particles were analyzed and correlated empirically to investigate the effect of particle shape and liquid surface tension. A bubble‐wakes interaction coefficient defined by Jean and Fan (1987) was determined for cylindrical particles.
Extraction and absorption with a vibrating perforated plate
Authors: Baird M. H. I. , Vijayan S. , Rao N. V. Rama , Rohatgi A. 
Published: March 2009

AbstractMass transfer rates and hydrodynamic behaviour have been measured for liquid‐liquid and gas‐liquid dispersions formed at small perforations (0.3 to 1.5 mm diameter) in plates vibrating at frequencies of 10–100 Hz and amplitudes in the order of 0.1 mm. The light phase (liquid or gas) is fed beneath the plate which is provided with a skirt so that the light phase passes through the perforations to form discrete drops or bubbles. Sauter mean diameter was generally in the range 1–2 mm.Mass transfer efficiency for liquid‐liquid transfer (acetic acid from kerosene to water) was found to be in the order of 70% for a single plate; the effect of cell depth on efficiency was small, indicating that most of the mass transfer occurred near the plate. In the case of gas‐liquid mass transfer (oxygen uptake by water), the volumetric mass transfer coefficient was in the order of 0.1 s−1, which compares well with conventional equipment.
Catalytic reactions of methylcyclopentane on HY zeolite
Authors: Abbot J. , Wojciechowski B. W. 
Published: March 2009

AbstractCatalytic reactions of methylcyclopentane have been studied on HY Zeolite at 500°C. Initial reactions include ring cleavage, the formation of paraffins and the formation of methylcyclopentane. Aromatic species are formed as both primary and secondary products. In contrast to the reaction of methylcyclopentane under reforming conditions, benzene is not a dominant initial aromatic product formed under cracking conditions. Unlike the reaction of cyclopentane on HY, the cracking of methylcyclopentane produces molecular hydrogen as an initial product. This we attribute to the presence of a hydrogen atom bonded to a tertiary carbon in the methylcyclopentane molecule.
Modelling of decomposition of a synthetic core of methane gas hydrate by coupling intrinsic kinetics with heat transfer rates
Authors: Jamaluddin A. K. M. , Kalogerakis N. , Bishnoi P. R. 
Published: March 2009

AbstractDecomposition of a synthetic core of methane hydrate has been modelled by Selim and Sloan (1985) and Ullerich et al. (1987) based on heat transfer considerations. In the present work, the decomposition is modelled by coupling intrinsic kinetics with heat transfer rates. Numerical simulation results are presented to show the effects of incorporating the intrinsic kinetic rate of decomposition. Simulation results indicate that by changing the system pressure we can move from a heat transfer controlled regime to a regime where both heat transfer and intrinsic kinetics have a significant effect on the global rate of decomposition.
Mass transfer in external‐loop airlift bioreactors using static mixers
Authors: Chisti Yusuf , Kasper Michael , Moo‐Young Murray 
Published: March 2009

AbstractThe influence of static mixers on the overall gas‐liquid volumetric mass transfer coefficient (KLaL) was examined in an external‐loop type airlift bioreactor (approximately 15 L volume, 1.8 m static liquid height, Ar/Ad = 0.444). The study was conducted with aqueous salt solution (0.15 kmol ṁ m−3 NaCl) and with pseudoplastic solutions of carboxymethyl cellulose (0.2 − 0.6 wt./vol. % (g/100 mL) CMC).Over a broad range of power law parameters K (10−3 − 10 Pa ṁ sn) and n (0.5 − 1.0), the presence of static mixers in the riser was found to enhance the KLaL relative to mixer‐free mode of operation. The extent of increase in KLaL depended on the fluid “thickness”, K: the higher the K, the greater the KLaL intensification due to static mixers. For otherwise identical conditions, the presence of static mixers improved KLaL by 30‐500%, depending on the fluid. The boost in KLaL was associated with increased gas holdup and gas‐liquid interfacial area, which arose due to bubble breakup accomplished by the static mixing elements. Potential advantages of static mixers in upgrading the performance of oxygen‐limited fermentations were pointed out.
Characteristics of circulating vortex in the through‐flow between two concentric rotating spheres
Authors: Nakabayashi K. , Tsuchida Y. 
Published: March 2009

AbstractThe flow pattern and velocity distributions in the annulus of two concentric rotating spheres with meridional through‐flow have been studied by a finite difference solution based on the full Navier‐Stokes equations. These results were compared with these from an available but necessarily more approximate analytical solution. The flow fields near the inlet and outlet were elucidated and the effect of the through‐flow Reynolds number on the radial and azimuthal velocity components were clarified. These latter results were unobtainable by the analytical solution.
pH and conductivity of concentrated aqueous sodium sulfide/sodium carbonate solutions undergoing carbonation
Authors: Norman Jack C. , Sell Nancy J. , Ciriacks John A. 
Published: March 2009

AbstractThe extent of conversion of Na2S to H2S in a concentrated aqueous solution of sodium sulfide and sodium carbonate undergoing carbonation can be monitored by measuring the pH and conductivity. A simple linear equation has been developed to correlate the percentage of Na as Na2S with the temperature, pH, and conductivity. The apparent hydrolysis constants for carbonate and sulfide were calculated at temperatures ranging between 25°C and 65°C, and the reaction enthalpies and entropies determined.
Phase equilibria predictions for the CO2‐H2O‐NaCl‐bitumen system
Authors: Nighswander John A. , Kalogerakis Nicolas , Mehrotra Anil K. 
Published: March 2009

AbstractPredictions of vapour‐liquid, liquid‐liquid and vapour‐liquid‐liquid phase equilibria are presented for the quaternary CO2‐H2O‐NaCI‐Peace River bitumen system at reservoir conditions. Henry's law correlations are regressed from available data for the CO2‐H2O, CO2‐(H2O + NaCl) and CO2‐bitumen binary sub‐systems. These correlations are incorporated into a model for predicting the phase behaviour of the quaternary system at temperatures of 80‐200°C, NaCl concentrations of 0‐10.5 mass% and pressures up to 10 MPa. It is shown that temperature, salt concentration and the global CO2 concentration significantly affect the distribution of CO2 in the liquid‐liquid region. The proposed model is simple and computationally less demanding than those based on equations of state.
Absorption of CO2 in some hybrid solvents
Authors: Yogish K. 
Published: March 2009

AbstractPhysico‐chemical absorption data of CO2 in three industrially important hybrid (physical + chemical) solvents were obtained in the temperature range of 0‐25°C and at a constant partial pressure of the gas of 95.59 kPa. The systems studied were N‐methyl 2‐pyrrolidone, sulfolane and methanol with a minute quantity of 40% aqueous dimethyl amine (aq.DMA). The CO2 uptake increased by two to three fold as compared to that of the pure physical solvents, and decreased with increases in temperature. Absorption also increased with the amount of aq.DMA added.