bluuebunny/crossref_metadata_2025_split huggingface dataset:
Optimisation of Methyl Tert‐Butyl‐Ether (MTBE) Synthesis Processes using Aspen‐Plus
Authors: Kim S. , Douglas P.L. 
Published: August 2010

AbstractFour different configurations for the production of MTBE were simulated and optimised using AspenPlus All process configurations were simulated and costed using AspenPlus The total annual cost (TAC), i e the sum of the individual annualised capital and operating costs, was calculated using models consistent with the conceptual design level Optimisation of each process configuration using AspenPlus simulation models was performed to determine the optimal design and operating variables The optimised configurations were compared on an economic basisIt was possible to achieve iso‐butylene conversions in the range of 90 to 97% with a single conventional reactor followed by a distillation tower However, by using a reactive distillation column it was possible to achieve iso‐butylene conversions > 99% The optimal configuration was found to be a combination of an isothermal reactor followed by a catalytic distillation column The optimal TAC of this configuration was 22% lower than its nearest competitor, the catalytic distillation columnIt was found that the net MTBE reaction rate remains high until a substantial amount of iso‐butylene is converted, and then decreases quickly as the reacting liquid composition approaches the reaction equilibrium Therefore, it is not surprising that the best means of synthesis is to carry out the bulk of the initial conversion using a conventional reactor and to apply reactive distillation to the reactor effluent that is close to equilibrium at the exit temperature
Models of an Industrial Evaporator System for Education and Research in Process Control
Authors: Kam Kiew M. , Saha Prabirkumar , Tadé Moses O. , Rangaiah G. P. 
Published: August 2010

AbstractRealistic models of typical industrial processes are essential for effective and practice‐oriented education and research in process control This paper presents two mechanistic models of an industrial five‐effect evaporator system, and also indicates their potential applications in process control‐related research and training Simulation programs for these models in four different platforms (viz, MAPLE, MATLAB, Simulink and C++) are developed Relative merits and application‐specific usefulness of these four platforms in process control studies are discussed
Drying Research ‐ Current State and Future Trends
Authors: Mujumdar Arun S. 
Published: August 2010

AbstractResearch and development activity in the inter‐ and cross‐disciplinary area of thermal drying has been escalating rapidly over the past two decades. It is clearly motivated by economic incentive to improve the operation to produce a better quality product at a lower cost in terms of resources, energy consumption as well as environmental impact. The focus to date has been on improving the engineering aspects of design and operation to produce “engineered” products of desired characteristics. Much remains to be achieved in relation to the material science aspects of drying, e.g. the prediction of quality parameters which are product‐dependent. What is needed is a generalised drying theory that incorporates the transient transport phenomena involved in drying along with appropriate models to account for the morphological changes, as well as chemical processes that may occur during drying.This paper will focus on the current developments in drying as well as recent trends. Some areas where more R&D is needed and which provide opportunities to make definitive contributions will be identified. For example, sophisticated analytical measurements at the micro‐scale are needed in order to examine the movement of moisture during drying, and also detect any changes in the physical structure as well as solute transport that can occur in drying of foodstuffs or solids containing a dissolved solid in the liquid phase. Even today, there is need to devise more efficient and compact dryers. Whether we will ever need “micro‐scale” dryers is a speculative question but certainly there will be the need to design dryers with high “volumetric” efficiency, unlike most dryers built today. Finally, there will be further developments and extended applications for superheated steam dryers, heat pump‐assisted hybrid dryers and multi‐stage dryers using different dryer types in each stage. Mathematical models for drying as well as for dryers will continue to be in demand to allow reliable design and scale‐up, as well as the control of industrial dryers.
Theoretical Study of Stress Reversal Phenomena in Drying of Porous Media
Authors: Kowalski Stefan Jan 
Published: August 2010

AbstractDrying of capillary porous materials may generate internal stresses, the magnitude of which depends on both the drying techniques and the mechanical properties of dried materials. Acoustic emission (EA), a method to monitor for damage control during drying, shows an enhanced emission of acoustic impulses and energy from the material in some stages of drying. A particularly interesting phenomenon is the occurrence of enhanced emission of the acoustic impulses at the final stage of drying, that is, at the time when the drying induced stresses are expected to disappear. This phenomenon is explained by the stress reversal, i.e. the change of stress signs from negative (compressive) inside the material at the beginning to the positive (tensional) at the final stage of drying. A theoretical analysis is presented in this paper using the viscoelastic model. Stress reversal was predicted and analyzed from drying cylinders of ceramics‐like material and wood.
Effect of Drying‐Aid Agents on Processing of Sticky Materials
Authors: Benali Marzouk , Amazouz Mouloud 
Published: August 2010

AbstractThermal drying is considered as an attractive option to slurry disposal especially for complex industrial residues containing fibers and/or sticky components such as animal fat. The proposed Jet‐Spouted Bed Dryer with inert particles (JSBDryer) is an advanced and energy efficient technology to obtain powders from solutions, slurries and pastes by drying on the surface of inert particles brought into intensive and random motion. An experimental study carried out on a 300 kW‐test bench for drying of meat‐rendering slurry in the JSBDryer is presented. Some basic characteristics of the jet‐spouted bed for Teflon cubes used as inert particles are also presented. The effects of calcium carbonate and wheat bran, used as drying‐aid agents, on the reduction of slurry stickiness are also discussed.
Application of Electrical Fields in Dewatering and Drying
Authors: Chen G. , Mujumdar A. S. 
Published: August 2010

AbstractThe application of electrical fields to dewatering and drying is reviewed. In particular, the developments in electroosmotic dewatering (EOD) of colloidal slurries are discussed in terms of fundamental associated phenomena, as well as the methods of enhancement of EOD. The electrohydrodynamic (EHD) drying of biological materials are discussed in terms of its fundamentals, current status, and advantages and disadvantages. The potential applications of this emerging technique are evaluated along with a discussion of R&D needs in these areas.
Correlation for Equilibrium Solubility of Calcium Sulfate Phases in Industrial Phosphoric Acid Production
Authors: Mukhopadhyay S. , White E.T. 
Published: August 2010

AbstractThe equilibrium solubility of gypsum (and calcium sulfate hemihydrate) in phosphoric‐sulfuric acid mixtures, similar to those used in practice in industrial wet phosphoric acid manufacture, was determined. The experimental data from this work and literature data were combined to develop solubility correlation equations for both calcium sulfate hydrate species over a full range of industrial conditions.
Computer‐aided Measurement of Vapour‐Liquid Equilibria in a Dynamic Still at Sub‐Atmospheric Pressures
Authors: Joseph M.A. , Ramjugernath D. , Raal J.D. 
Published: August 2010

AbstractA compact new dynamic VLE apparatus has been developed capable of rapidly and accurately furnishing data suitable for separation process design. The equipment is computer controlled to fine tolerances of pressure and temperature and can produce either isobaric or much useful isothermal VLE data. The design incorporates a packed equilibrium chamber of the Yerazunis et al. [1] type in a novel arrangement. It is suggested that VLE stills relying only on a Cottrell pump are unlikely to reach true equilibrium regardless of how long the recirculation period, particularly for system of high relative volatility and or high liquid viscosity. To test the performance of the apparatus, isobaric VLE data were measured for the cyclohexane‐ethanol system at 40 kPa, and isothermal VLE data at 313.15K, 323.15 K and 333.15K. The isobaric data were in good agreement with the data of Morachevsky and Zharov [2]. The isothermal VLE data were found to be thermodynamically consistent. Infinite dilution activity coefficients, in good agreement with literature values were found from the isothermal data by the method of Maher and Smith [3]. Reasonably accurate excess enthalpy estimates were also calculated. The VLE data were best correlated with the Wilson [4] equation. An analysis of the temperature‐pressue sensitivity for binary systems defines the precision required in the control of either pressure or temperature and dictates the choice of equipment for a given system.
The Rheological and Mechanical Performance of Polyvinyl Chloride/Ethyl Vinyl Acetate Formulations for Medical Device Applications
Authors: Mcconnell D.C. , Mcnally G.M. , Murphy W.R. 
Published: August 2010

AbstractThe incentive for this research is a result of the current issues arising over the use of flexible polyvinyl chloride (PVC) in medical devices, particularly with respect to their disposal and the use of migratory low molecular weight plasticisers. The debate at present involves consideration of the disposal of PVC by incineration, creating dioxins which environmentalists claim are harmful and the use of phthalates as leaching plasticisers which also present a health risk. This work investigates the suitability of ethyl‐vinyl acetate (EVA) copolymer as a permanent polymeric replacement plasticiser for use in flexible PVC formulations particularly for medical device applications. A range of powdered EVA copolymers and PVC formulations were compounded at ratios 100:0, 60:40, 50:50, 40:60 and 0:100 respectively. Two grades of EVA with 20% and 27% vinyl acetate (VAc) content and a grade of PVC with a K‐value of 71 were used in the investigation. Mechanical analysis was performed on injection moulded samples of these blends and the results showed that the tensile and flexural modulus decreased significantly with increasing EVA concentration. Rheological analysis was performed using dual capillary rheometry and the results showed only slight changes in shear viscosity with increasing EVA content even at lower shear rates. Dynamic mechanical thermal analysis showed partial miscibility of the PVC and EVA over the range of concentrations studied, thus indicating that EVA does have a plasticising effect on PVC.
Gasification of Waste Medium Density Fibreboard as a Route to Power Generation
Authors: Williams B.C. , Mcilveen‐Wright D. , Rezvani S. 
Published: August 2010

AbstractMedium density fibreboard (MDF) processing in Northern Ireland generates about 40 tonnes of MDF dust per week, which gives significant disposal problems and costs. The overall aim of this project was to develop an environmentally friendly, energy efficient and economically acceptable means of generating “green” electricity from MDF dust.The project is based on using a down draught fixed bed gasifier with a modified diesel engine generator. Before MDF dust can be used in the gasifier it must first be briquetted. Although many equipment manufacturers claim to be able to briquette MDF dust, only two were able to prove this capability, PLC Products and Kahl. Trials were arranged and as a result a B10 Bio‐Compactor was purchased and installed. However, good quality briquettes could not be produced reliably due in part to a lack of experience in operating the B10 Bio‐Compactor and in part to mechanical failures. Changes were made to the B10 Bio‐Compactor to improve its mechanical integrity and further trials will be performed to establish the conditions required to make MDF briquettes reliably.In order to provide MDF briquettes for the gasification trials it was decided to use MDF off‐cuts sawn to the correct size. The project team was happy that these off‐cuts possess very similar properties to the briquettes produced by the B10 Bio‐Compactor and would therefore give very similar gasification behaviour. The gasification trials were very successful, with 8 hours continuous operation without problems. The calorific value of the fuel gas produced was 4.8 MJ/nm3, which is almost identical to that obtained from normal hardwood chip fuel. From the gasifier a mixture of diesel and MDF fuel gas was fed to the diesel engine generator. This is the normal practice for these types of engines in order to maintain smooth and efficient combustion. No problems were experienced when changing over from diesel to the fuel gas mixture
Biomass Gasification for Combined Heat and Power In the Chipboard Industry
Authors: Williams B. C. , Henderson P. , Mcilveen‐Wright D. 
Published: August 2010

AbstractThis paper provides details of a feasibility study into the application of small‐scale wood chip gasification‐based combined heat and power (CHP). Gasification itself is not a new technology, however there has been renewed interest recently in the quest for small‐scale gasification from renewable energy sources, such as biomass and wood waste. The UK Government is committed under the Kyoto Protocol and various EC regulations and recommendations to reducing greenhouse gas emissions, increasing the use of renewable energy sources and increasing energy efficiency through the use of CHP. This technology will help to achieve all three of these goals.There has been an assessment of the wood chip supply position in Ireland, based on information from Balcas, the largest timber milling company in Ireland, and the Northern Ireland Forestry Service. This study shows that there has been a 30% increase in output from Ireland's forests over the last five years. A conservative estimate is that over the next five years the output will increase by another 60%, mainly in the North West of Ireland. Therefore, the volume of wood chips required for any proposed size of CHP unit is not expected to have any noticeable impact on the market price or availability of wood chips.
Robust Process Control Based on the Passivity Theorem
Authors: Bao J. , Lee P. L. , Wang F. , Zhou W. 
Published: August 2010

AbstractA robust process control strategy based on the passivity theorem is proposed in this paper. The uncertainties are characterised in terms of a revised passivity index. The passivity‐based robust stability condition is derived and the tradeoffs between the robustness and nominal performance are analysed. Using Semi‐Definite Programming, a two‐step controller design procedure is developed to meet both the passivity‐based stability condition and nominal performance specifications. As both the phase and gain information of the uncertainties are taken into account, the control method proposed may achieve better performance for the same robustness requirement than conventional H∞ control. This is illustrated by an example of the control of a reactor.
Optimisation of an Agitated Thin Film Evaporator for Concentrating Orange Juice Using Aspen Plus
Authors: Chawankul N. , Douglas P. L. , Chuaprasert S. , Luewisutthichat W. 
Published: August 2010

AbstractThis paper presents an application for the optimisation of an existing agitated sdthin film evaporator (ATFE) for concentrating orange juice using Aspen PlusTM. A rigorous heat exchanger mode (Heatx) and a rigorous two‐phase flash model (Flash2) were used to simulate the dominant effects of the ATFE. The thermo‐physical properties of orange juice, not available in Aspen Plus, were determined experimentally and correlated as functions of temperature and solids content by Boonsriudomsuk [1]. Effective heat transfer coefficients were calculated from measured temperatures and flow rates.Experiments were performed on a laboratory‐scale and pilot plant system and compared with the simulation results. The Aspen Plus simulation model using experimentally determined heat transfer coefficients and thermo‐physical properties of orange juice compared well with the experimental data from the ATFE. When the mass and energy balance data were reconciled the errors between both experimental and simulation results were significantly decreased.The optimisation results indicated that by operating at the optimum operating conditions the operating costs could be reduced by about 10%. This translates into savings of more than $10.000/vear in the case of the laboratory‐scale evaporator and $33,000/year in the case of the pilot plant. If a commercial ATFE process was optimised then the potential savings could approximate to $330,000/year. Clearly, process optimisation is a valuable tool in the design and operation of these processes.
Simulation of the Industrial Packed Bed Catalytic Reactor for the Partial Oxidation of Methanol to Formaldehyde:
Authors: Moustafa T. M. 
Published: August 2010

AbstractA detailed diffusion‐reaction kinetic model was developed in this study for an industrial methanol partial oxidation reactor. Unlike, most of the kinetic models in the literature that either neglected or approximated the intra‐particle diffusion, the details of the mass transfer limitations were taken into consideration for this reaction system. The catalyst pellet was modeled using the rigorous dusty gas model based on Stefan‐Maxwell equations. Four reactions are considered and an efficient minimization routine was used to extract the kinetic rate coefficients for these reactions using industrial reactor data.
Production of Crystalline Boric Acid through the Reaction of Colemanite Particles with Propionic Acid
Authors: ZareNezhad Bahman 
Published: August 2010

AbstractA new process for boric acid production is developed. In this process the crystalline boric acid particles are directly produced in a one‐stage crystallizer through the reaction of colemanite particles with propionic acid. Each porous colemanite particle is comprised of spherical solid grains. It is found that the solid boric acid produced precipitates on the unreacted core of the grains. The maximum overall conversion of colemanite particles can be increased to 97% if the propionic acid concentration, stirrer speed, concentration, stirrer speed, colemanite mean particle size and temperature are set at 16 kmol/m3, 20 Hz, 462 μ and 295 K, respectively. Therefore it is possible to use this process as an alternative for boric acid production, also having a useful side product. A particle‐grain model is successfully used for process simulation.
Desulfurization of Egyptian Petroleum Coke
Authors: Aly I.H.M. , Magdy Y.H. , Barakat N.A.M. 
Published: August 2010

AbstractFerric chloride and benzene were examined with many other chemicals to be used as solvents for the sulfur‐bearing compounds present in the Egyptian petroleum coke. The best results were obtained when ferric chloride and benzene were used consecutively, and more than 35% degree of desulfurization was obtained in this case. The kinetic study showed that the combination of the three rate processes, namely for diffusion of ferric chloric through a liquid film, surrounding the coke particles, and in the coke ash layer, plus chemical reaction of the ferric chloride with the sulfur‐bearing compounds present in the petroleum coke, will provide overall control of the process. Activation energy of the process was found to be 12 kJ/mol.
Solubility of Manganese Sulfate Monohydrate in the Presence of Trace Quantities of Magnesium Sulfate Heptahydrate in Water
Authors: Maeda Kouji , Matsuoka Wataru , Fukui Keisuke , Chandra Eric Sukma , Ang Ha‐Ming , Tadé Moses 
Published: August 2010

AbstractThe solubility of aqueous manganese sulfate monohydrate has been measured in the presence of magnesium sulfate as the second salt. Over the temperature range from 273 to 353 K, aqueous manganese sulfate on its own exhibited an unusual behavior in that its solubility reached a maximum at an intermediate temperature of 293K. The solubilities of manganese sulphate under and over the maximum solubility temperature were first predicted individually by the electrolyte NRTL model. The binary interaction parameters and solubility parameters were universal parameters that were applied to any salts consisting of manganese, magnesium and sulfate ions, and they were newly obtained from the binary solubility data. The predicted solubility curves could represent the experimental data quantitatively, and adequately described the effect of co‐salt of magnesium. The experimental solubility data were also satisfactorily correlated with the electrolyte NRTL model.
Flow Injection Analysis for Aluminium using 3‐Hydroxy‐4′‐Chloroflavone
Authors: Nishioka Hiroshi , Nagahiro Tohru 
Published: August 2010

AbstractA flow injection system is described for the determination of aluminium. This method is based on the formation of a fluorescent complex with 3‐hydroxy‐4′‐chloroflavone. The maximum wavelength of its excitation and emission spectra are 397 and 455 nm, respectively. A 200μl aliquot of sample solution is injected into a carrier (distilled water) which is pumped at 1.1 ml min−1. The reagent solution is prepared by mixing the flavone ethanol solution (1x10−4 M) and buffer solution (PH 4) in the volume ratio of 5:1. The reagent solution is also pumped at 1.1 ml min−1. Aluminium ion in the sample solution reacts with flavone in the coil (0.5 mm i.d. x 3 m) to form a fluorescent complex. A linear relationship was observed between peak heights and aluminium concentrations in the range of 2.4‐100 ng ml−1. The relative standard deviation for five replicate injections is 0.9%. A routine sampling rate of 20 determinations per hour can be achieved by the proposed method.
On the Mechanism of the Interfacial Reaction in Extraction of Rare Earth Metals by D2EHPA
Authors: Tomita Akihiro , Kanki Tatsuo , Sano Noriaki , Asano Tsuyoshi , Imai Shingo 
Published: August 2010

AbstractThe mechanism of interfacial reaction was discussed based on the constituent of the crystal film which forms at the interface and the practical behavior of interfacial tension with the aid of intermolecular potential determined by ab initio molecular orbital calculation. It was shown that there are three different reaction zones depending on hydrogen ion and extractant concentrations. A couple of extractant monomer(s) and/or its anion(s) first react with a lanthanide ion to form 1:2 intermediate complex. At the concentration zone where the crystal formation occurs, the 1:2 intermediate complex reacts with adjacent extractant monomer or its anion to form crystallized 1:3 complex. At lower extractant concentrations, the 1:2 intermediate complex reacts with extractant monomer or its anion and further with extractant dimer to form the stable 1:6 complex which should dissolve into the organic phase. At higher extractant concentrations, the 1:2 intermediate complex reacts with extractant dimer to form the stable 1:6 complex dissolving into the organic phase.