bluuebunny/crossref_metadata_2025_split huggingface dataset:
The Freeze Concentration Process and its Applications
Authors: Englezos P. 
Published: August 2010

AbstractIn this paper, the freeze concentration separation process is described and the status of its industrial applications is reviewed. The pilot plant and commercial applications in the chemical and food processing industry for desalination and environmental protection, and in the pulp and paper industry are summarized. The advantages of using this process in the various industrial sectors as well as the limitations are delineated. The development of the clathrate hydrate process is also discussed. Finally, some anticipated developments are described.
Determining Optimum Column Height in Direct‐Contact Heat Transfer Columns
Authors: Lench M.J. , Worthington H. 
Published: August 2010

AbstractA potential use for direct‐contact heat transfer in a cooling crystalliser has led to this investigation of a countercurrent direct‐contact heat transfer system. A computer‐based incremental model for predicating column height has been developed as a design tool. Certain simplifying assumptions are incorportated into the model, which gives agreement with experimental data to within the experimental error of 20%.
Production of Crotonaldehyde from Acetaldol
Authors: Atalay S. , Atalay F. S. 
Published: August 2010

AbstractOptimum operating conditions for the production of crotonaldehyde from acetaldol were investigated and the kinetics of the reaction were determined. The most important operating conditions were found to be the cracking time, the pH value of the reaction mixture, and the initial concentration of acetaldol. The order of the reaction was found to be 1.8 with respect to the acetaldol concentration. The kinetic parameters were determined to be 20.583 (m3/kmol)0.8/min for the frequency factor, and 3416.800 kJ/kmol for the activation energy.
Alumina‐Ceramic Microfiltration Membranes: Preparation, Characterization and Some Properties
Authors: Mikuláŝek P. , Doleček P. , Šedá H. , Cakl J. 
Published: August 2010

AbstractThe thin‐layer ceramic membranes have a chemistry and morphology that are different from polymeric membranes. These differences expand the application of membranes into environments where current polymeric membranes fail, and require an evaluation of the characterization and performance parameters.The conventional method that was adapted for the preparation of microfiltration alumina membranes is described. The use of a liquid displacement (modified bubble‐point) method to characterize tubular membrane microfilters in terms of pore sizes and pore size distributions is presented. The flux performance of supported alumina membranes is also described. The pore size distribution of tubular filters and flow of liquid through the membranes are discussed. Experimental results for different alumina microfilters are presented.The characterization studies reported in this paper are applicable to other ceramic membranes and represent a significant advance in the understanding of the performance of ceramic membranes in various applications.
An Adaptive Bilinear Model‐Predictive Control Algorithm for a Plate Heat Exchanger
Authors: Al‐zahrani A. A. , Wali M. M. Noor 
Published: August 2010

AbstractAn adaptive bilinear model‐predictive controller having a single tuning parameter, was used to control the temperature for a plate heat exchanger simulation. The parameters of the bilinear model are estimated at each sampling instant via a recursive least‐square method with a variable forgetting factor. The model and the control algorithm are updated accordingly. An algorithm for elimination of steady‐state offset was also implemented.The controller performance was tested for various changes in load and setpoint. It was found that adaptation eliminates the need for a filter. The controller performance was found to be excellent when the steady‐state offset compensator algorithm was implemented.
Removal of 230Th and other Metals from Sulphuric Acid Leach Uranium Mill Solution by Solvent Extraction, Adsorption and Precipitation
Authors: Nirdosh I. , Vogl A. K. , Carroll S. M. 
Published: August 2010

Abstract230Th and other metals were removed from the Key Lake (Saskatchewan) uranium mill leach solution by three methods. First, solvent extraction with D2EHPA, TBP and Primene JMT in kerosene diluent. Second, by adsorption on MnO2 and clays. Third, using metal hydroxides after they were precipitated out from the leach solution. It was found that complete removal was possible with either 5 vol% Primene JMT (plus 5 vol% iso‐decanol) in 90 vol% kerosene, or by adsorption onto clays, or with hydroxides precipitated at pH > 2.4. Both 230Th and 226Ra adsorption on clay conformed to the Freundlich isotherm.
Dissolution of Potash Ore in Solutions of High Sodium Chloride Concentration
Authors: Gillies R.G. , Madge D.N. , Shook C.A. 
Published: August 2010

AbstractAn experimental investigation of the dissolution of KCI‐containing ore in brines of high NaCl content has been conducted. The dissolving surface was vertical and motion of the solution was due only to free convection. The effects of ore composition and brine NaCl concentration were studied for unsaturated brines using both reconstituted ore and raw ore slabs (11.5 cm high). These dissolution rates were consistent with previous free convection heat and mass transfer results, when the interfacial solution was assumed to be saturated with respect to both KCl and NaCl (the invariant point composition).Dissolution by brines saturated with respect to NaCl was investigated with respect to the effects of crystal size in the slabs, solution KCl concentration, temperature and time. Dissolution rates were much lower in these cases and appeared to be controlled by a surface reaction. The mechanism of dissolution appears to involve penetration of the slab by the dissolving solution.
Correlation of Mass Transfer Coefficient in Stratified Gas‐Liquid Two‐Phase Flow in a Horizontal Rectangular Duct
Authors: Tomida T. , Suekuni N. 
Published: August 2010

AbstractLiquid‐side mass transfer coefficients were determined using a horizontal rectangular duct (3cm x 3cm and 4m length) with carbon dioxide desorbing from water and from aqueous solutions of malt syrup. Simultaneously, measurements were made of the parameters characterizing the liquid film flow such as the liquid film thickness and surface velocity. Experiments were mainly conducted within the range of stratified gas‐liquid two‐phase flow. Based on the analogy between mass and momentum transfer at the liquid film surface, the experimental data for the liquid‐side mass transfer coefficient were correlated with the liquid‐film flow velocity. In order to estimate the parameters of film flow, a correlation for the average film thickness was obtained, and the surface velocity was represented graphically as a function of the gas velocity, slip velocity and superficial liquid Reynolds number.
Prediction of Holdup in Pipe Two‐phase Gas‐Liquid Co‐current Down Flow at −45d̀
Authors: Spedding P.L. , Mcbride W.J. 
Published: August 2010

AbstractHoldup was measured for air‐water co‐current two‐phase flow in a perspex tube (45.4 mm id) set at an angle of −45d̀. The data were used to check the predictions of holdup given by various models (>120) using the input and geometrical conditions of the experiments. The prediction data were grouped according to the flow regimes that were observed for the system. Four models gave acceptable predictions for the annular‐plus‐wave condition, two of the models were also successful in predicting the annular‐plus‐droplet regime. Ten models were successful with droplet flow, and four models with the slug‐plus‐froth regime. No model could predict successfully for either the stratified or slug‐type flow regimes. In general, prediction performance deteriorated as the downward angle of inclination increased from the horizontal position.
Modification of Particles Using Silane and Methane in a Plasma‐Jet Fluidized Bed Reactor
Authors: Uemiya S. , Hanabusa T. , Kojima T. 
Published: August 2010

AbstractModification of alumina and carbon particles using silane and methane was carried out in a D.C. plasma‐jet fluidized bed reactor at atmospheric pressure. XRD, SEM and EPMA results showed that b‐SiC was formed inside and on the surface of the carbon particles. For the alumina particles, metallic Si was deposited inside and on the surface of the particles, but unfortunately the X‐ray reflection peak of b‐SiC was difficult to observe due to interference by the alumina peak. Speculations are offered concerning the mechanism of the deposition inside and on the surface of the particles.
Review of Real Time Optimization in the Chemical Process Industries
Authors: Naysmith M. R. , Douglas P. L. 
Published: August 2010

AbstractReal Time Optimization (RTO), or On‐Line Optimization, is the continuous reevaluation and alteration of operating conditions of a process so that the economic productivity of the process is maximized subject to operational constraints. The purpose of this paper is to review the available literature in the area of real time optimization, with particular attention to the methodologies being used at present. The general components which make up a real time optimizer, the process model, objective function, optimization algorithm, data reconciliation and gross error detection, are also reviewed. Finally implementation of real time optimizers is covered including user interfacing and on‐going maintenance of the system.
Use of Fluidized Bed for Intensification of Microfiltration on Ceramic Membranes
Authors: Mikulášek P. , Filandrová L. 
Published: August 2010

AbstractThe influence of a fluidized bed on permeate flux during the microfiltration of model dispersions by ceramic membranes has been studied Following description of the basic characteristic of alumina tubular membranes, model dispersions and the spherical particles used, some comments about the experimental system and experimental results for different microfiltration systems are presented From analysis of the experimental results it is concluded that the use of a fluidized bed resulted in a significant increase in permeate flux when compared with results obtained in an empty tube system. This phenomenon is especially pronounced during the microfiltration of polymeric dispersion when the permeate flux in a fluidized bed system was nearly five times higher. It was found that the optimum porosity was approximately 0.8 for a fluidized bed exhibiting maximal values of permeate flux.
Investigation of Flux in Flat‐Plate Modules for Membrane Distillation
Authors: Burgoyne A. , Vahdati M.M. , Priestman G.H. 
Published: August 2010

AbstractA theoretical model for predicting the behaviour of membrane distillation by incorporating mass and heat transfer equations has been used to find permeate fluxes, and has been validated experimentally. The model accurately predicts mass and heat transfer. The main work studied the effect of module design using a flat‐plate module in laminar flow conditions. Areas of investigation included the use of channels across the membrane surface, decreasing the available membrane surface area, and widening the inlet and outlet channels. The work showed that widening the channels increased the flux. Increased flux was also obtained by the use of channels on the permeate side, though not on the feed side.
Kinetics Studies on Effect of Recycled Water on Flotation of Copper Tailings from Benambra Mines, Victoria
Authors: Haran N. P. , Boyapati E. R. , Boontanjai C. , Swaminathan C. 
Published: August 2010

AbstractBatch rougher flotation study was conducted on copper tailings from Benambra to compare flotation kinetics at optimised condition, using Melbourne, mine, dewnised and recycled waters. The results showed an enhanced copper grade and recovery when deionised water was used as compared to when Melbourne, mine or recycled waters were used, the greaterflotation rate was due to the near absence of dissolved organic and inorganic species. Fresh mine water gave better copper grade and recovery and an enhanced flotation rate as compared to Melbourne water. Improved flotation kinetics in first recycling of Melbourne and deionised waters were observed. Three recycles of mine water in the flotation process indicated a steady‐state rate for copper tailings. This was not valid for Melbourne and deionised waters where flotation was inhibited successively by three water‐recycles. Organic species such as thio‐phosphates and carbamates released from residual reagents in water, and inorganic speciesfrom the tailing sample that dissolves, are responsible for altering water quality and hence the flotation kinetics.
Nonlinear Driving Force Approximations of Intraparticle Mass Transfer in Adsorption Processes: The Effect of Pellet Shape
Authors: Georgiou A. , Kupiec K. 
Published: August 2010

AbstractA general nonlinear driving force (NLDF) approximation of adsorbate uptake rate in terms of pellet geometry is presented. The results show that the accuracy of the proposed NLDF model is very good over the entire time (fractional uptake) domain, significantly improving over both the Linear Driving Force (LDF) and the Quadratic Driving Force (QDF) models.
Holdup Prediction in Vertical Upwards to Downwards Flow
Authors: Spedding P. L. 
Published: August 2010

AbstractTests of holdup prediction models have shown that horizontal/vertical flow conditions in general gave different performance than downward flow conditions. For horizontal/vertical flow the slug/bubble regimes were handled by the Nicklin [22] model; the annular regimes by the Spedding‐Spence [42] and Spedding‐Chen II [27] models; the droplet and film‐plus‐droplet regimes by the Taitel‐Dukler [48] model; the stratified‐blow‐through‐slug regime by the Hughmark [14] and Turner‐Wallis [49] models; the annular‐blow‐through‐slug regime by the Lockhart‐Martinelli [19], Chen [7], Spedding‐Chen [27], Spedding‐Spence [42], Nishino [23] and Gregory‐Scott [13] models. Stratified flows could not be handled completely by any model although the Kawaji [17] and Spedding‐Hand [29] and Hart [16] models handled horizontal flow. For downward inclinations the annular‐plus‐droplet and droplet regimes were handled by the Chen [7], Spedding‐Chen II [27], Taitel‐Dukler [48] and Spedding‐Hand [29] models. Other regimes were not handled by any one model, highlighting the need for development of new models based on a particular understanding of flow in the region of downward flow.
Membrane‐Based Gas Separation: Potential Energy Recovery and Greenhouse Abatement Applications
Authors: Da J. C. D. , Lu G. Q. , Rudolph V. 
Published: August 2010

AbstractDiversification of energy supply is generally regarded as desirable, particularly if directed to renewable energy and greenhouse benign technologies. Various opportunities are becoming available for the application of memebrane‐based gas separations, particularly for upgrading landfill gas. Although the trade‐off between permeability and selectivity is an inherent conflict of priorities for the design of membranes, research and development efforts have focused on selecting materials and developing synthesis processes to improve both selectivity and permeability. This paper considers the use of landfill gas as a significant global renewable resource, and the various methane (CH4) purification technologies. The development of materials to enhance membrane‐based gas separations is also discussed.
Landfill Gas Utilisation Trends in Australia
Authors: Xu X. , Rudolph V. , Greenfield P. F. 
Published: August 2010

AbstractThis paper presents the prospects for landfill gas (LFG) utilisation in the largest three cities in Australia, Sydney, Melbourne and Brisbane, based on their current Municipal Solid Waste (MSW) handling processes. The trends in landfill technology and legislation affecting the performance of gas capture and use are discussed. The traditional evaluation methodology to assess the economic feasibility for individual LFG exploitation projects is also discussed and criticised. Suggestions for desirable amendments which incorporate public judgements on the values of environmental conservation are included. Based on this analysis, utilisation is shown to be far more attractive than currently perceived.
Flotation of a Copper‐Zinc Ore Usingp‐Nonylcupferron as Collector
Authors: Natarajan R. , Nirdosh I. , Muthuswami S. V. 
Published: August 2010

AbstractBench‐scale flotation tests were done with a chalcopyrite, sphalerite and pyrite‐containing ore from Timmins, Canada using p‐nonylcupferron as collector. Effects of pH and the need for adding copper sulphate for zinc activation and lime as pyrite‐depressant were studied. The collector floated nearly 94% copper and 94% zinc without pyritic iron in 30% mass at pH 4 and 5, and 93% Cu and 78% Zn at pH 6 in 30% mass. At higher pH values, metal recoveries were poor. No copper sulphate was needed for activating zinc flotation. Addition of lime did not affect pyrite suppression.
Aqueous Phase Oxidative Degradation of 4–Hydroxy Nitrobenzene over a CuO‐TiO2 Catalyst
Authors: Suen C. L. , Adesina A. A. 
Published: August 2010

AbstractThe aqueous phase oxidation of 4‐hydroxy nitrobenzene (or p‐nitrophenol) has been carried out in a semibatch slurry reactor operating at the relatively mild conditions of 373‐393 K and 80‐150 kPa oxygen pressure. The catalyst employed has a composition 5CuO:5TiO2:100SiO2 and was maintained at 11.4 g/L in the reactor. Kinetic data were collected under conditions of negligible internal transport resistance. The degradation rate has an order of about 1.43 with respect to the 4‐hydroxy nitrobenzene but weakly dependent on the oxygen partial pressure (approx. 0.12). Analysis of the concentration‐time data revealed that the autocatalytic effect frequently seen during phenol oxidation was non‐existent in the reaction pathway. A Langmuir‐Hinshelwood single‐site mechanism involving the oxygen‐assisted cleavage of the benzene ring as the rate‐controlling step offered a kinetic model that accurately described the rate data. Estimates of the adsorption equilibrium constants for both p‐nitrophenol and oxygen were also thermodynamically consistent and activation energy was valued at 42 kJ/mol. Excellent activity of the catalyst was attributed to chemical synergy arising from the interaction between surface CuO and TiO2 crystallites to give a new sphene‐type phase containing the highly intrinsically active centres for the catalytic process.
Catalytic Conversion of LPG to High‐Value Aromatics: The Current State of the Art and Future Predictions
Authors: Al‐Zahrani S. M. 
Published: August 2010

AbstractThis paper is an attempt to summarize the current position of catalytic conversion of LPG to aromatics. The low reactivity of LPG has long impeded its utilization as a petrochemical feedstock. Except for its use in the cracking of ethylene, LPG fractions have mainly been consumed as fuel. Recently new catalytic processes now being commercialized have opened up new routes for the utilization of LPG as a source of valuable petrochemical intermediates. Five main processes are now available for converting LPG to aromatics, these processes are: M‐2 Forming, Cyclar, Aroforming, Z‐Forming, and the Alpha process. The aromatization reaction mechanisms are generally accepted to be through dehydrogenation of paraffins to olefins (which is the rate limiting step), then oligomerization to form dimers and trimers intermediates, followed by cyclization and dehydrogenation to aromatics. The most selective catalytic systems employed in the aromatization of LPG are mainly zeolite‐containing promoted catalysts.
The Utilization of Fluidized Bed Reactors for Oxidative Coupling of Methane
Authors: Al‐Zahrani S. M. , Abasaeed A. E. 
Published: August 2010

AbstractA simple mathematical model for the oxidative coupling of methane in a fluidized bed reactor has been developed in order to investigate the possibility of exploiting the advantages of this reactor configuration for the important exothermic reaction, and also to provide an insight into potential scale‐up behaviour. The model is based on the two‐phase theory of fluidization, and the reaction kinetics are based on triangular kinetics obtained from the literature. Without adjusting any of the hydrodynamic or kinetic parameters, the model predicted fairly well the experimental results obtained from the literature under various reaction conditions, and it was then used to investigate the effect of scale‐up on the conversion and selectivity obtained in the methane oxidative coupling process. High C2 selectivities at reasonably high methane conversions are shown to be possible with large scale fluidized bed reactors.
The Effect of Other Cations in Wastewaters on the Ion‐Exchange Removal of Ammonium Ion
Authors: McVeigh R. J. , Weatherley L. R. 
Published: August 2010

AbstractTraditionally in the water treatment industry biological filtration and activated sludge are the processes used to control ammonia levels. These processes have a slow response time to conditions such as shock loadings and temperature changes. Ion‐exchange can offer a tertiary clean up stage if the previous processes are unable to meet the ammonia consent levels. Secondary treatment wastewaters contain considerable concentrations of calcium, magnesium, potassium and sodium as well as ammonia in the cation form. Previous work has shown that clinoptilolite, a naturally occurring alumino silicate, has a high selectivity for NH4+ relative to other ions present in wastewaters making it an effective zeolite for the process of ion‐exchange.Investigations into the effect various cations may have on the ion‐exchange removal of ammonium have been carried out. Results are presented of isotherm studies and packed bed breakthrough work for NH4+ uptake onto the zeolite. Findings show that K+ ions tend to have the greatest inhibitory effect on the physio‐chemical process and that ammonium removal capacities can be reduced by over 20%.
The Effect of Stunning Method on the pH of Lamb
Authors: Mcgeehin B. , Butler F. , Sheridan J. J. 
Published: August 2010

AbstractThe postmortem pH decline of lamb M. longissimus thoracis was measured to investigate how it is affected by two methods of animal stunning at slaughter. Electrical stunning was compared to captive bolt stunning but there was no difference between the pH of these groups at any of the times postmortem. Both of the stunning techniques produced a wide range of pH values, even as early as 0.5 h postmortem, indicating that other factors are the cause of pH variability in lamb M. longissimus thoracis.
Experimental Analysis of Rotating Instabilities in Swirling and Cyclonic Flows
Authors: O'Doherty T. , Griffiths A. J. , Syred N. , Bowen P. J. , Fick W. 
Published: August 2010

AbstractThis paper reviews the work carried out since 1990 in establishing the characteristics and properties of rotating instabilities found in swirling flows, such as those of cyclone dust separators and swirl burners. Considerable efforts have been made over the years in establishing the cause and use of these instabilities in swirling flows. The general conclusion indicates that there is potential benefit in its existence in combustion systems, but is detrimental within dust separation/classification systems. The analysis of these flows have included laser diagnostics (Laser Doppler anemometry, particle image velocimetry and flow visualisation), temperature mapping and numerical analysis. Many of the experimental measurements use a phase locking system based on cyclic pressures. The following paper reviews and updates the numerical modelling of the instability found in rotating flows.