bluuebunny/crossref_metadata_2025_split huggingface dataset:
Application of Linear Additivity Principle in Ball Mill Grinding Processes
Authors: Liu L. X. , Lu G. Q. 
Published: August 2010

AbstractThis paper presents an experimental verification of the linear additivity people of mixed balls in ball mill grinding processes through batch grinding tests of pulverized‐coal slag from power plants. Based on an nth order model of the grinding process, the theory is also applied to the calculation of suitable ball media composition for an industrial continuous mill. The change in ball media composition as calculated using the model, results in a 20% increase in production from an industrial mill.
On the Limitations of the Diffusion Equation
Authors: Hussein E. M. A. 
Published: August 2010

AbstractThis paper identifies the physical limitations inherent in the laws of Fickian diffusion by critically examining various derivations of the diffusion equation. Particle transport theory, statistical mechanics, and thermodynamic principles are utilized for this purpose. It is rigorously demonstrated that diffusion describes a quasi‐equilibrium and nearly isotropic process at regions away from external boundaries and sources or sinks of the transported quantity. It is also proven that the diffusion equation is not applicable to transport within a void, or when the vector flux changes rapidly with time.
Prediction of the Reid Vapor Pressure of Gasolines with MTBE and Other Oxygenates
Authors: Furzer I. A. 
Published: August 2010

AbstractA new method has been developed for the prediction of the Reid vapor pressure of gasolines containing oxygenates such as MTBE, ethanol and methanol. This method accounts for the significant deviations in the liquid phase which dominate the sensitivity of the Reid vapor pressure to small additions of oxygenates. Results obtained over a wide composition range show that the Reid vapor pressure increases most rapidly with methanol additions, to a lesser degree without MTBE, and least rapidly with ethanol.
Numerical Simulation And Design For Continuous Flow Extraction in an Emulsion Liquid Membrane
Authors: Long R.L. , Lin C. C. 
Published: August 2010

AbstractA model for extraction by the emulsion liquid membrane in a continuous flow reactor is presented. The extraction of the solute through the individual emulsion globule is based on the Modified Diffusion Model. The extent of the emulsion conversion in the extractor is calculated in terms of the extractor capacity. The design of the extractor is based on the extractor capacity. It is found that extractor capacity increases with increasing average residence time of the emulsion globules in the extractor.
Application of Compensation Control in FCC Main Fractionator
Authors: Yang S. H. , Wang X. Z. , Mcgreavy C. , Sen X. X. , Mao F. Z. 
Published: August 2010

AbstractA compensation control system is developed and applied to the main fractionator of a fluid catalytic cracking unit. A compensation model is used for the outlet temperature of light cycle oil (LCO) accounting for the top pressure change of the column. A corrected temperature is used as a indication of the pour point of LCO, and the top pressure of the column is used as a feedforward signal to maintain the pour point by means of a predictive feedforward control. The control strategy has proved successful in the FUJIAN refinery of the China Petrochemical Inc. which is used as an example of the system.
Data Reconciliation Using AspenPlus
Authors: Piccolo M. , Douglas P. L. , Lee P. L. 
Published: August 2010

AbstractProcess measurements made in chemical plants generally do not satisfy material and energy balance constraints due to random or possibly gross errors in the measuring device readings. Data reconciliation is a method of adjusting random errors in the measurements in a weighted least squares sense in order to satisfy the process constraints. Linear data reconciliation involves solving a linear system of mass and energy balances as well as inequality constraints. Non‐linear data reconciliation, involving non‐linear mass and energy balances and constraints, is substantially more complex and requires a significant amount of work in developing the model and/or solution strategy.Steady state simulation packages equipped with optimization routines can be used to perform data reconciliation and parameter estimation with existing models which automatically satisfy mass and energy balance constraints. The time required to develop a data reconciliation problem can be shortened by using these packages without sacrificing the quality of the results. Five examples are presented to illustrate this technique using the AspenPlus flowsheet simulation and Optimization system. The first four are simple problems taken from literature and are included to validate the method. The fifth example involves a nonlinear industrial distillation example included to illustrate the scope of the technique.In the fist four cases, the solution to the data reconciliation problem war easily developed and quickly solved. The fifth example involved somewhat more work but was still relatively quickly developed and solved. Steady state process simulation systems can be used to perform non‐linear data reconciliation. The reduction in development time increases dramatically with the problem complexity involving staged separation and multiple units.
Kinetics of Adsorption of Pb (II) on Used Tea Leaves and Cr (VI) on Acacia Arabica Bark
Authors: Tiwari D. P. , Saksena D. N. , Singh D. K. 
Published: August 2010

AbstractAdsorption of Pb (II) on used tea leaves and Cr (VI) on acacia arabica bark after chemical pretreatment exhibit nearly first‐order reversible reaction kinetics in wastewater treatment. Adsorption follows Langmuir and Freundlich isotherm models. Effective parameters such as initial metal‐ion concentration, adsorption dosage, and size of adsorbent particles have been correlated to enable prediction of the equilibrium adsorption of metal ions within a maximum deviation of ± 10% from experimental data.
Modelling and Dynamic Simulation of an Industrial Rotary Dryer
Authors: Duchesne C. , Thibault J. , Bazin C. 
Published: August 2010

AbstractRotary dryers are widely used in chemical and mineral processes due to their flexibility and simplicity of operation. Nevertheless, the comprehension of the basic phenomena taking place in this type of dryer is still of great interest. In order to better understand the phenomenological behaviour of the process and to assess product moisture control strategies, a complete dynamic simulator of a mineral concentrate dryer has been developed The simulator is calibrated with industrial data and consists of a furnace model, a solids transportation model and a gas model, including the heat and mass transfer phenomena. The dryer simulator was shown to adequately represent the dynamic behaviour of an industrial rotary dryer.
A Study of Two‐Phase Co‐current Flow in Inclined Pipe
Authors: Spedding P. L. , Ferguson M. E. G. , Watterson J. K. 
Published: August 2010

AbstractData are presented on horizontal and slightly inclined flows at +50 and ‐50 for a cocurrent air‐water system in α 0.0508 m i.d. pipe.The predictive ability of existing flow regimes maps were shown to be inadequate. New maps were proposed for horizontal and slightly inclined up and downward flow. Several transitional criteria were shown to be useful in prediction for horizontal flow.Both liquid holdup and pressure drop characteristics for inclined flows were different either side of a superficial gas velocity of 10 m s−1. Below this value upward flow had the greatest pressure loss and horizontal flow the least. Above the 10 m s−1 the opposite was the case. For holdup; Vsg < 10 m s−1 led to down flow having the lowest value but for Vsg > 10 m s−1 the horizontal condition had the lowest value. Upflow always possessed the highest liquid hold‐up value.The Olujic [80] and Spedding‐Hand [71] models were successful in predicting most flow regimes for horizontal flow except stratified ripple and blow‐through‐slug, annular droplet and the intermittent regimes. The inclined flows proved more difficult to predict.
The Influence of Changes to Mixing on the Sooting and NOx Emission Characteristics of Unconfined Turbulent Jet Diffusion Flames
Authors: Newbold G. J. R. , Nathan G. J. 
Published: August 2010

AbstractResults are presented from new measurements of vertically fired unconfined diffusion flames issuing from precessing jet nozzles and new calculations of existing data from simple jet flames. These results provide quantitative information about large‐scale mixing, NOx emissions and sooting tendencies of precessing jet flames. It is shown that a characteristic large eddy strain rate at the tip of a precessing jet flame is reduced by an order of magnitude when compared to that in simple jet flames. The reduction in large eddy strain rate correlates with an increased sooting tendency that is consistent with findings for simple jet flames presented elsewhere. The reduction in strain rate correlates with decreased NOx emissions and is found to be contrary to flamelet model predictions for simple jet flames.
The Effect of Particle Size and Heating Rate on the Transformation of Sulphur during Pyrolysis of a South Australian Low‐rank Coal
Authors: Telfer M. A. , Heidenreich C. A. , Zhang D. K. 
Published: August 2010

AbstractParticle size and heat transfer effects on organic and inorganic sulphur transformations during pyrolysis are investigated using temperature‐programmed pyrolysis and fixed‐bed pyrolysis (700‐900°C) of pulverised Bowmans coal, and fluidised bed pyrolysis at 800°C of 6, 8 and 10mm diameter cylindrical coal pellets. Results are interpreted using a heat transfer model [8]. The pyrolysis experiments reveal that during the initial devolatilisation stage, organic and sulphate sulphur decomposition occurs at a rate directly proportional to heating rate and inversely proportional to particle size. Towards the end of the devolatilisation stage, the transportation of volatiles out of the coal decreases so that sulphate undergoes solid‐state transformations to form organic sulphur in the char. The reincorporation process is accelerated by higher reaction temperatures or heating rates which allows greater decomposition of sulphate and longer periods of slow devolatilisation to support the solid‐state reactions. Smaller particles in the fluidised bed reveal a similar effect due to faster internal heating rates. Larger particle sizes also facilitate organic sulphur increase due to slow internal heating rates and hence slow and extended devolatilisation and sulphate reincorporation.
Research on the Combustion of Lower Volatile Coal in PFBC
Authors: Zhang Mingyao , Sun Chenliang , Liu Qianxin , Tang Chuming , Jin Baosheng , Shen Xianglin 
Published: August 2010

AbstractUp to now, five sets of P—200 PFBC—CC Commercial Demonstration Power Plant are operating in the world, in which the bituminous coal and lignite are used as fuel and the combustion efficiency can reach higher than 99%. But using lean coal or anthracite as fuel it will not be satisfied for the expected value. So the combustion characteristic of these lower volatile coals must be tested and the methods of solving problem will be supplied. This paper will discuss and analyze some results from tests as follows:

The investigation of the burning characteristic for different coals under pressure,

The comparison of the combustion efficiency in PFB combustor for different coals,

The research results with fly ash circulating technology for lower volatile coals.
Power Generation and Greenhouse Gas Abatement: The Effects of Generation Efficiency, Fuel Type and Renewables
Authors: Millar G. , Hessami M‐A. 
Published: August 2010

AbstractPower generation in Australia is responsible for about 25% of the country's greenhouse gas emissions. Due to the abundance of coal, most power stations use this fuel as the primary source of energy. The high carbon content of coal combined with the relatively poor power generation efficiency of these facilities, explain the contributions which power generation make to Australia's greenhouse gas emissions. In this paper, the effects of these two parameters, ie, fuel type and generation efficiency, on greenhouse gas abatement is studied. It is shown that by controlling these two factors, there is a significant potential to reduce greenhouse gas emissions in Australia.An analysis of the electricity market showed that renewable energy projects and natural gas fired power stations cannot compete on price with coal fired power stations. Carbon taxes and green energy programs are seen as the most likely ways to make renewable energy and natural gas competitive with coal, and thus reduce greenhouse gas emissions caused by power generation.
A Kinetic Study on the Production of Toxic Compounds in Enclosure Fires Under Suppression by Halon Replacement Extinguishing Agents
Authors: Moghtaderi B. , Dlugogorski B. Z. , Kennedy E. M. 
Published: August 2010

AbstractThis paper presents the results of a theoretical investigation designed to characterise the mechanism of formation of those toxic compounds which are produced when halon replacement extinguishing agents are released in the hot upper‐layer of typical enclosure fires. The present work was primarily motivated by the fact that in many building fires the extinguishing agent may not be directly applied to the flame but released in the hot layer. For this purpose, detailed chemical kinetic modelling techniques were used to predict the generation of combustion products and toxic byproducts within the hot layer. This can be justified based on the fact that recent studies in this field have shown that the production of major combustion products in the upper‐layer is kinetically controlled. Effects of the mixing phenomenon were investigated by considering two possible extremes using infinitely fast and infinitely slow mixing models. The heat loss variation was also studied under isothermal and adiabatic conditions. Calculations presented here show that the concentration of toxic compounds originated from halon replacement extinguishing agents are much higher than those of halons mainly because for such agents, due to the lack of significant chemical reaction inhibition, higher extinguishing concentration are required.
Uncertainty of an Environmental Risk Ranking Analysis
Authors: Hutchison R. B. , Witt H. H. 
Published: August 2010

AbstractA semi‐quantitative PC tool to rank environmental risks and to assess the cost‐benefit of capital expenditure proposals for risk reduction has been developed by ANSTO Safety and Reliability. The ranking method, which is typical of semiquantitative techniques, is summarised. City Rail (the Sydney railway operator) has used the tool to rank the risks of undesired spillage at many of its sites. The results of this application of the tool were examined to determine the accuracy of the ranking. Such information is relevant to the ongoing development of the method and provides some assurance that the analysis is robust and providing useful information.The methodology uses environmental science, engineering and site operations expertise. The operations are examined to generate a list of possible environment damaging scenarios and associated point estimates of the likelihood and the quantity of material released. For each material‐scenario combination, transfer effectiveness estimates are assigned based on the pathway to the receptors. Scenario risks are ranked using these estimates along with ratings for the impact of each hazardous material, and ratings for the ecological sensitivity of the sites.Since the method is reliant on numerical judgements the uncertainty of the scenarios' ranking should be determined. Three techniques were used to assess the uncertainty of the parameter estimates. The accuracy implied by the number of significant figures assigned to estimates was examined and considered unrealistic.The number of discrete values actually used in the results gives an indication of the analyst's implicit judgement. The third technique was subjective assessment of the parameter estimate's uncertainty by independent analysts. The subjective assessment of the uncertainty was significantly larger than the two other uncertainty estimates.These uncertainty estimates were used to estimate the uncertainty of the calculated risk scores by using a Monte Carlo simulation. This technique enabled the uncertainty of the parameter estimates to be propagated to determine the uncertainty of the final calculated results. From the data used in the City Rail study and subjective estimates of the uncertainty of parameter values, risk scores from this model differing by at least two orders of magnitude can be confidently (95%) said to be different Conversely, when the risk scores differ only by a factor of two, there is only a 60% confidence that the relative ranking is correct
Monitoring of 2‐D Combustion Temperature Images in a 670 t/h Utility Boiler and Simulation of its Application in Combustion Control
Authors: Zhou H.‐C. , Zhang S.‐S. , Huang Y.‐L. , Zheng C.‐G. 
Published: August 2010

AbstractA simple method of monitoring 2‐D temperature images from monochromatic gray images of flames captured from utility boilers, and reference temperatures measured by two‐color pyrometry, are presented in this paper. In a 670 t/h utility coal‐fired boiler furnace, the magnitude of the combustion temperature fluctuation can reach as high as 180 K under normal conditions. Furthermore, a two‐loop combustion control strategy was proposed with steam pressure as its outer‐loop control variable and the radiant energy signal as the inner‐loop control variable. Simulation on the single‐and two‐loop control strategies clearly indicates that the two‐loop control strategy can realize a more economical utilization of fuel. It also ensures steady steam pressure and safer conditions for the superheater surface tubes (not to be overheated) making the boiler respond quickly to the load change.
Sulfur‐RiteTM: A Big, New Answer to Small H2S Removal Problems
Authors: Cantrall Rosalind 
Published: August 2010

AbstractUS Filter's Gas Technology Croup (USF/GTP) is currently introducing a new H2S removal process named Sulfur‐RiteTM. Sulfur‐Rite is specifically designed to remove small quantities of H2S (≤ 125 kg/day) from all types of gas streams. The Sulfur‐Rite process can remove H2Sfrom gas streams at any pressure. For non‐hydrocarbon gas streams the temperature is limited to approximately 115° and for hydrocarbon gas streams the temperature is limited to approximately 82°C. The non‐hazardous, environmentally friendly Sulfur‐Rite media converts H2S to iron pyrite (fool's gold). In addition to H2S, the Sulfur‐Rite process can remove approximately 50% of methyl and ethyl mercaptans. The spent media may be disposed of in a non‐hazardous landfill or made into compressed blocks for structural use or in some instances used as a soil supplement. The Sulfur‐Rite Equipment Packages are designed and supplied by USF/GTP. Single vessel and lead/lag dual vessel systems are available. This paper will discuss in detail the gas streams that can be treated, the equipment available, the advantage of Sulfur‐Rite over certain types of scavenger processes, and the disposal of the spent media.
Application of Chaos in Chemical Process Optimization
Authors: Chenzhong Luo , Chunkai Zhang , Huihe Shao 
Published: August 2010

AbstractChaos has initial condition sensitivity, intrinsic irregular property and ergodicity, so it was applied to optimization problems. Two new methods were proposed for this kind of application: chaos search method combined with exact non‐differentiable penalty function for nonlinear constraint optimization, and chaos mutation operator for real‐coded evolutionary algoriths. Both are simple and easy to implement. Simulation with a chemical process optimization problem shows that the proposed methods are effective and reliable.
A Study in Advanced Control Application to an Azeotropic Distillation Column within a Vinyl Acetate Monomer Process Design
Authors: Olsen D.G. , Young B.R. , Svrcek W.Y. 
Published: August 2010

AbstractSimulation of a Vinyl Acetate Monomer (VAM) process design is developed in this work to allow testing of two advanced control strategies within the base PI control scheme Specifically, the two schemes focus on improving the control performance of the azeotropic distillation column A detailed steady‐state and dynamic analysis of the distillation column has been performed to provide insight into the control behaviour of the two composition loops The possible benefits from this type of study include production increase, safer operation and lower operating cost To the authors' knowledge, this paper represents the first time a ratio control scheme and a model predictive controller (MPC) have been applied to the VAM process and presented in the open literature Simulation results are presented to illustrate the effectiveness of the new control strategies
Spray‐Dried Particle Morphologies
Authors: Walton D.E. 
Published: August 2010

AbstractParticulate powders and particle morphologies produced by spray drying are discussed, along with factors that affect powder quality, e.g. process conditions, and particle properties. Structural categories of spray‐dried particles are demonstrated and related to various drying mechanisms. The methods of studying particle morphology are also outlined with particular reference to the single droplet drying method, reportedly analogous to industrial spray drying and possibly other particulate formation processes. The advantages and disadvantages of the method are discussed and the importance of particle morphology to powder technology emphasised.
A Model for the Approach to Solubility Equilibrium in Crystallizing and Dissolving Systems
Authors: Dalziel S.M. , White E.T. , Johns M.R. 
Published: August 2010

AbstractAccurate equilibrium solubility data is important when studying the crystallization behavior of a compound. Measurements of solubility can be hindered by the length periods encountered during the approach to equilibrium. This is especially true for proteins and other compounds with relatively slow crystal growth rates. A new model curve fitting technique is developed and applied, which is equally applicable to crystallizing and dissolving systems. The curve fitting inputs are: (i) measurements of solute concentration as a function of time, taken during the dynamic approach to equilibrium; and (ii) the order of crystal growth or dissolution kinetics. The equilibrium solubility is an output parameter of the curve fitting. Where properly used, this curve fitting technique can give a more precise estimate of solubility equilibrium. The technique is applied to the measurement of solubility for glucose isomerase, an industrial enzyme.
The Structure and Interactions of Species in Supersaturated Caustic Aluminate Solutions
Authors: Addai‐Mensah Jonas , Li Jun , Prestidge Clive A. 
Published: August 2010

AbstractThe influence of akali metal ions (Na+ and K+), hydrogen isotope (H and D) and temperature on apparent hydrodynamic molar volumes, structure and interactions of species in synthetic, supersaturated caustic aluminate solutions (Bayer liquors) has been investigated. A strong dependency of structure, size and species interactions (ion‐ion and ion‐solvent) on the three primary variables was revealed. Sodium and deuterium‐based liquors displayed higher viscosities, reflected in greater attractive interactions, higher activation energies and entropies of viscous flow, than potassium and hydrogen‐based liquors. The apparent, hydrodynamic molar volumes of the viscosity modifying species were larger in sodium and hydrogenated than in potassium and deuterated aluminate liquors, and decreased with increasing temperature. Ionic strength‐independent average molar mass of Al(III)‐containing species close to 100 g mol1 and corresponding to monomeric, tetrahydroxo aluminate (Al(OH)) species was observed.