International Review of Chemical Engineering

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International Review of Chemical Engineering (Rapid Communications) - May 2010 - Papers

Effect of Particle Shape on the Drying Rate of Solid Particles
Variation in Measurements of Turbulence Intensity in Pipe Flow
Numerical Analysis of Swirling Turbulent Flow in a Model Combustor
Indirect Electrochemical Reduction of Vat Dyes: Process Optimization for Indigoid, Anthraquinonic and Polycyclic Vat
Determination of Yarn Swelling Diameter Using Capillary Rise
Viscosity Measurement of n-Dodecane and n-Hexane and their Binary Mixtures at Combined High Pressure and Ambient and Sub-Ambient Temperatures of 20°C and 5°C
Use of Hyperheuristics to Solve Nonlinear Algebraic Systems: Application to Double Azeotrope Calculation
Management of Water Loss Based of Bayesian Networks
The Flexible Method for Risk Assessment of Chemicals in Manufacturing

Special Section on 1st “Material Processes and Environment” Francophone Conference (31 May-6 June 2010)

Preface to the Special Section
Impact of the Thermal Inertia of Material on the Hygrothermal Comfort of Building
3D Stochastic Reconstruction of a Porous Material
Thin Polymer Film Plaster Covered
Rheological Behavior of Some Aqueous Suspensions with Al₂O₃-ZrSiO₄
Nano-Heterogeneous Structure and Fragile/Strong Character of Glass Forming Silicate Melts
Reducing Sludge Production at Source in Urban Wastewater Treatment Plants - Solubilization Performances by Ultrasounds, Temperature and Ozone Treatments
Assessment of the Part of Hydrosoluble Organic Compounds Present in Waste Using Leaching Test
For an Integrated Management of Municipal Solid Waste in Algeria. Systemic and Methodological Approaches
Composite Materials from Solid Wastes and Synthetic Resin
Preparation of Hematite Based Humidity Sensors by Means of Electrophoretic Deposition Technique
A New Treatment of Hydorgen Sulfide Enriched Condensates

Extracted by CEAM 2009 - 1^st International Conference on Chemical Engineering and Advanced Material)

Biocoagulants for Water and Waste Water Purification: a Review
Diagnosis of Atmospheric Corrosion by SO₂ Emitted from Oil Installations at the North of Chiapas and Center of Tabasco, Mexico
Rheology on the Way from Dilute to Concentrated Emulsions

Multi-Objective Optimization: Techniques and Applications in Chemical Engineering (Book Review)
Production Chemicals for the Oil and Gas Industry (Book Review)

International Review of Chemical Engineering (Rapid Communications) - Papers

Effect of Particle Shape on the Drying Rate of Solid Particles
by Margono, Ali Altway, Susianto, Kuswandi

Vol. 2. n. 3, pp. 329-336

Abstract - The aim of this work was to study the effect of particle shape on the rate of drying by use of an isothermal drying diffusion model of solid particles with a Newman boundary condition, such that the Biot number is an important parameter. The question to be answered by this study was as follows: Between two factors related to particle shape, particle specific surface and moisture diffusion length, which has the greater effect on the drying rate? Spherical and cylindrical particles with various height-to-diameter ratios were studied. Particle shape was described using Wadell sphericity _S and diffusion-based sphericity ψ which is defined as the ratio between the equivalent particle radius and the average diffusion path length. The latter was the distance between the particle center and its outer surface. Partial differential equations that described unsteady state diffusion of moisture within the particles were solved using a polynomial approximation method implemented with Matlab software. An analytical solution based on the separation- of- variables method was also derived to validate the approximation method. The solutions for the unsteady-state model are presented as dimensionless plots of average moisture content versus drying time, and rate of drying versus average moisture. The approximate solution agreed very well with the analytical solution for Biot numbers of 0.1 to 5. As expected, particles with either the lowest Wadell sphericity, _S= 0.694 or the highest diffusion-based sphericity, ψ = 2.8845 (cylindrical particle with H/D = 0.25), exhibited the highest drying rate. The dimensionless drying rate of this particle was approximately 400% faster than that of the spherical particle. Note that the specific surface of this particle was 144% greater than that of the spherical particle and the moisture diffusion length was 290% shorter. Thus, it appears that in comparison with the particle specific surface, the moisture diffusion length has a greater effect on the drying rate.

Keywords: Rate of Drying, Moisture Content, Drying Time, Sphericity.

Variation in Measurements of Turbulence Intensity in Pipe Flow
by Mark A. Pepple, Jennifer S. Curtis, Caner U. Yurteri

Vol. 2. n. 3, pp. 337-342

Abstract - Many well known single-phase axial turbulence profiles were compared with the present axial fluctuating velocity data obtained with LDV in water at Re>10⁵ over the interval 0 ≤ r/R ≤ 0.6. The profiles differed in regard to fluid type (air and water), Re (5.3x10³ ≤ Re ≤ 6.1x10⁶), pipe diameter (25.4 mm ≤ D ≤ 254 mm), measurement technique, and scaling quantity. DNS results at Re 5.3x10³ and 4.46x10⁴ were included in the comparison. In general, the results showed a surprising amount of variation among literature values of axial fluctuating velocity, with those measurements obtained in water generally greater than those obtained in air. Additionally, profiles obtained in air with LDV are more flat than those obtained with a hot-wire. No Re dependence was found in air but dependence was observed in water.

Keywords: Turbulence Measurement, Laser Doppler Velocimetry, Hot-Wire.

Numerical Analysis of Swirling Turbulent Flow in a Model Combustor
by Showkat J. Chowdhury, Tyler Kirby

Vol. 2. n. 3, pp. 343-351

Abstract - A numerical study is made to characterize the non-reacting (isothermal) swirling turbulent flow in a model combustor with dilution air, having practical applications in industrial furnaces and jet engines. Dilution air is used to protect the combustor wall and turbine blades by cooling the combustion products to the desired temperature. The governing differential equations using k – ε turbulence model closure are solved by a control-volume based iterative finite difference technique. Computations are done for both constant vane angle and solid body rotation swirl generators at inlet, and for different swirl numbers up to 1.5. The predicted distribution of the mean axial and tangential velocities, turbulence kinetic energy and streamline plots are discussed. With the increase of swirl strength, secondary on-axis recirculation due to swirl is observed. In addition to flame stabilization, the swirl produces larger turbulence kinetic energy and enhances mixing rate including efficiency of the combustion process, thus shorter combustor length is required. The flow in the combustor with co-rotating, non-rotating or counter-rotating secondary dilution air has been analyzed. The computational model has been validated by comparing the results with available experimental data. Grid-independency test has also been done and found to be satisfactory.

Keywords: Combustor, Computation, Dilution Air, Recirculation, Swirl, Turbulent Flow.

Indirect Electrochemical Reduction of Vat Dyes: Process Optimization for Indigoid, Anthraquinonic and Polycyclic Vat
by Wafa Miled, Neji Ladhari, Ayoub Haj Saïd, Sadok Roudesli

Vol. 2. n. 3, pp. 352-358

Abstract - In this work we describe the electrochemical reduction of three vat dyes from different chemical structures namely, indigoid, anthraquinonic and polycyclic vat dyes. The electrochemical reduction was performed indirectly using an electrochemical redox couple. The reduction degree in the dye bath was simultaneously monitored by potentiometry and potentiometry at imposed current techniques. Color yield and fastness properties of samples dyed by the electrochemical process were compared with those of samples dyed by conventional way using sodium dithionite. The experimental results showed that the dyeing performances were similar.

Keywords: Electrochemical Reduction, Mediator, Vat Blue1, Vat Orange 11, Vat Violet 1.

Determination of Yarn Swelling Diameter Using Capillary Rise
by S. Benltoufa, F. Fayala, S. Ben Nasrallah

Vol. 2. n. 3, pp. 359-363

Abstract - This paper investigated the effect of swelling ratio on a capillary kinetics. A mathematical model was developed based on the industrial construction parameters, the capillary mechanism and swelling ratio. The capillary was studied, considering swelling effect on the variation of yarn diameter. In order to validate our model, a series of experiments was conducted on cotton jersey knitting varying construction parameters and using samples with different swelling ratio (Cotton and PET). The results showed a good agreement between experimental data and theoretical prediction of yarn diameter using a capillary kinetics compared to microscopic method.

Keywords: Capillary Kinetics, Macro-Pores, Micro-Pores, Swelling Ratio.

   Viscosity Measurement of n-Dodecane and n-Hexane and their Binary Mixtures at Combined High Pressure and Ambient and Sub-Ambient Temperatures of 20°C and 5°C
         by E. P. Fernández, C. J. Schaschke
        Vol. 2. n. 3, pp. 364-370

Abstract - We report the measurement of the viscosity of pure n-dodecane and n-hexane and their binary mixtures under combined conditions of high pressure up to 200 MPa and at ambient and sub-ambient temperatures of 20oC and 5oC. Using a thermostatically controlled falling sinker-type viscometer, reproducible and reliable viscosity data were obtained from terminal velocity sinker fall times. Liquid viscosities were found to increase exponentially with both rising pressure and reducing temperature according to the Barus equation. The Tait equation was used to determine compressed density and the Grunberg and Nissan equation used to predict the viscosity of mixtures. Additionally, pressure and thermal freezing were found to also occur with increasing pressure and lowering temperature.

Keywords: Falling Sinker, High-Pressure Viscometry, Tait Equation, Barus Equation, Grunberg and Nissan Equation.

Use of Hyperheuristics to Solve Nonlinear Algebraic Systems: Application to Double Azeotrope Calculation
by Gustavo M. Platt, Ivan N. Bastos, Roberto P. Domingos

Vol. 2. n. 3, pp. 371-377

Abstract - The calculation of homogeneous non-reactive azeotropes using a new stochastic technique called hyperheuristics was performed. The hyperheuristics consist of a set of metaheuristics (stochastic optimization algorithms) that works inside a specific metaheuristic frame. With this procedure, was possible to obtain simultaneously both azeotrope compositions and temperatures (at specified pressure) of systems that exhibit double azeotropy. Results were presented for the benzene+hexafluorobenzene system at low pressures. Because of very good simulated results obtained, we consider that the application of hyperheuristics is a promising and powerful tool to solve complex nonlinear problems in chemical engineering context.

Keywords: Double Azeotrope, Nonlinear Systems, Hyperheuristics.

Management of Water Loss Based of Bayesian Networks
by Camelia Gavrila, Narcisa Teodorescu

Vol. 2. n. 3, pp. 378-382

Abstract - The losses that occur in water pipes installations can lead to the fact that some quantity of water does not reach the consumers, due to possible damages occurred in the distribution system. Bayesian networks and their associated methods are especially suited for capturing and dealing with uncertainty. A reason for this paper is that developing systems for solving problems, having the complexity present in monitoring the water loss, is still a major task. An effective way for saving water and money is represented by the localization and solving the damages that appear in a pipe-network. The structure of the models is achieved using probabilistic (chance) nodes and directed links (structure). The parameters (influences between variables) are quantified and stored in conditional probability tables.We propose an interactive Bayesian network and a decision theoretic system which intend to monitor the water loss, to likely predict the outcome and to select the appropriate decisions. We consider that the model proposed in this paper offers a good way of monitoring the water distribution system. This way, isolations and remedies for the damages are possible.

Keywords: Bayesian Networks, Management, Water Loss.

The Flexible Method for Risk Assessment of Chemicals in Manufacturing
by P. Tint, K. Reinhold

Vol. 2. n. 3, pp. 383-389

Abstract - This study focuses on risk assessment of chemicals and dust in manufacturing. An innovative approach to assess the occupational hazards using a flexible risk assessment method is presented. The method is worked out as an alternative to the risk assessment method presented in British Standard 8800 and is more understandable for employers who have to carry out risk assessment themselves. Practical examples and the results of measurements of occupational hazards in five industries (mechanical, printing, wood, plastic and textile) are presented. The overall purpose of the paper is to draw the attention to the importance of measurements of occupational hazards in industry and to act as a reminder of number of issues of practical relevance to effective workplace risk assessment from which employees, employers, occupational hygienists and physicians as well as authorities can benefit today and in the future.

Keywords: Workplace Risk Assessment, Chemical Hazards, Measurements in Manufacturing.

Special Section on 1st “Material Processes and Environment” Francophone Conference (31 May-6 June 2010) - Papers

Preface to the Special Section
by Guy Matejka

Vol. 2. n. 3, p. 390

Impact of the Thermal Inertia of Material on the Hygrothermal Comfort of Building
by Dalel Medjelekh, Saliha Abdou, Mohammed El Ganaoui

Vol. 2. n. 3, pp. 391-397

Abstract - The thermal inertia of buildings, topic of our subject is behind the intelligent relation that rests in on the good thermal exchange understanding between the inside and the outside. She participates in the good output, to the good use and the comfort of the thermal machine (building). An investigating has been led on a house of the colonial time in Guelma town (Algeria), in order to estimate the role of the inertia on hygrothermal comfort. Results show that the use of a local material adapted to the region climate is to the origin of the realization of hygrothermal comfort and the consumption reduced of the energy. The validation of results of the investigating by the software computer TRNSYS reaffirms the major role of the thermal inertia in the maintenance of the hygrothermal interior balance. Although, the thermal inertia of materials, according to results, must be associated to the means of heating and natural cooling (nocturnal ventilation) for the most unfavorable situations.

Keywords: Thermal, Inertia, Hygrothermal, Comfort, Building, Material.

3D Stochastic Reconstruction of a Porous Material
by M. R. Arab, B. Pateyron, J. P. Lecompte, M. El Ganaoui, J. C. Labbe

Vol. 2. n. 3, pp. 398-404

Abstract - A stochastic reconstruction scheme via the simulated Annealing method (SA) is developed here in order de represent the 3D microstructure of a porous material so, its properties can be estimated. The 2D image, obtained by Scanning Electron Microscope (SEM), is treated and then the different statistical information contained, as the 2-points correlation function and the lineal path function are extracted from this image.

Keywords: Simulated Annealing, Stochastic Reconstruction, N-points Correlation, Lineal Path Function, Lattice Boltzmann.

Thin Polymer Film Plaster Covered
by Lidia Radu, Ovidiu Dumitrescu, Marcela Muntean

Vol. 2. n. 3, pp. 405-408

Abstract - A thin polymer film applied on the plaster sample surface improves its physical-mechanical properties and also, increases its stability to water, and against various chemical agents. Compressive strength and especially flexural strength increase 2-4 times for coated plaster in comparison with normal plaster. As polymer coating was used an ecological epoxy resin, based on vegetable oils, which presents many advantages compared to the in use epoxy resins. Such behavior of the coated plaster samples could open an interesting field of application in construction, for repair or for architectonical works. It can be also used as a replacement of White Portland Cement, an expensive building material.

Keywords: Coated Plaster, Composite Material, Plaster, Ecological Epoxy Resin, Interface SEM.

Rheological Behavior of Some Aqueous Suspensions with Al₂O₃-ZrSiO₄
by Maria Spătaru, Ovidiu Dumitrescu, Ioan Mircea Popescu, Marcela Muntean

Vol. 2. n. 3, pp. 409-412

Abstract - In the technological practice, the suspensions fluidity is a difficultly and ticklish problem due to the systems complexity, due to the presence of cations and anions in solution, due to their selective adsorption in the double electrical layer. For the fluidity is not a unique recipe and seldom are used two or more additives, in the established proportions by experiment. Aqueous suspensions from alumina-zircon were obtained through electrosteric stabilization with Arabic gum, sodium carboxymethylcelullose and polyvinyl alcohol, through wet grinding into the mills with corundum balls for 5 hours. It was ascertained that, the nature, amount and mixture of the additives were influenced both grains size distribution, mean size of the grains and implicitly, the viscosity of suspensions, although grinding time was the same. Rheological behavior was pseudoplastic with rheopex character. It was tried the finding a rheological model for optimizing these types of suspensions correlating experimental data through a function of polynomial interpolation. The degree of precision (r²) of the polynomial regressions was greater for the equations more complex, what was also confirmed by the graphs of the residuals points.

Keywords: Aqueous Suspensions, Alumina-Zircon, Fluidity, Properties, Rheological Model.

Nano-Heterogeneous Structure and Fragile/Strong Character of Glass Forming Silicate Melts
by Dorel Radu, Ovidiu Dumitrescu

Vol. 2. n. 3, pp. 413-417

Abstract - The nature of the entities present in oxide vitreous systems is dependent on the structural levels considered. Thus, at the first level these are represented by the atoms (ions) present. A second structural level is characterized by the presence of certain structural elements, represented by coordination polyhedra. These consist of the coordination numbers of the individual atoms, each related to the neighbors with chemical affinity (form bonds). The characterization of glass structure at these two levels can be applied at the sub-nanometric scale (< 1 nm). At the next level, the structure is defined as a series of aggregates having distinct size and chemical composition. These appear through the linking (only using the vertexes) of elemental structural units. The type and percentage of each aggregate is defined regarding the degree to which chemical structural equilibrium was achieved. At this level of analysis the nanometric scale is used. A correlation between the fragile/strong character of silicate glass melts and their nano-heterogenous structure was obtained by using rigid sphere theory and the chemical-structural equilibrium theory. Numerical applications are presented for a sodium metasilicate glass.

Keywords: Fragile/Strong Character of Melts, Rigid Sphere Theory, Nanoscale Structure of Glass, Silicate Glasses.

Reducing Sludge Production at Source in Urban Wastewater Treatment Plants - Solubilization Performances by Ultrasounds, Temperature and Ozone Treatments
by Julien Laurent, Mélanie Pierra, Mohamad R. Salsabil, Audrey Prorot, Magali Casellas, Christophe Dagot

Vol. 2. n. 3, pp. 418-421

Abstract - Three disintegration techniques aiming at excess sludge production reduction at source in wastewater treatment plants were investigated: ultrasound, heating and ozone. The nature of solubilized compounds suggested that thermal and ozone treatment induced cell lysis. The performances of the processes were evaluated in terms of sludge total suspended solids removal with respect to the energy spent during the treatment. From this point of view, ozonation appeared the most suitable technique.

Keywords: Sludge Minimization, Ultrasound, Thermal, Ozone.

Assessment of the Part of Hydrosoluble Organic Compounds Present in Waste Using Leaching Test
by A. Parodi, G. Feuillade, A. A. Mansour

Vol. 2. n. 3, pp. 422-425

Abstract - Despite national recycling campaigns, the amount of Municipal Solid Waste (MSW) to be treated remains very important in France. Almost 39% of this production goes to landfills. With the increasing concern over sustainable development and energy valorisation, it seems essential to optimize current treatment and develop new preparation methods of this waste. In this perspective, the leaching test (LT) coupled with measurement of quantity and quality of biogas assays could be used as a tool to evaluate the mobilization of organic compounds. The organic matter is characterised by fractionation according to the hydrophobic character of the molecules carried out using XAD resins. Results would be used to assess the performance and the efficiency of new ways of waste treatments.

Keywords: MSW, Leaching Test, Organic matter, Fractionation.

For an Integrated Management of Municipal Solid Waste in Algeria. Systemic and Methodological Approaches
by B. Bouhadiba, F. Mezouari, Y. Kehila, G. Matejka

Vol. 2. n. 3, pp. 426-429

Abstract - The aim of this study is the design of a new mode of integrated municipal solid waste (MSW) management in Algeria based on an approach taking into account systems by themselves, the different multi-sectors, and the various technologies. The system approach considers the triptych producer ↔ consumer ↔ decomposer (or transformer), specific of natural ecosystems, essential to regulate the exchange of matter, energy and information for anthrop-urban systems and particularly those involved in the system because they will be transformed in solid waste. Two previous studies have been done on two sanitary landfills located in Alger and Biskra. From the results obtained we have recommended the use of an accurate pretreatment. This is especially suitable for waste before their burial. This advantage is that this procedure provides a natural organic fertilizer for Algerian soils and in addition reduces the waste volume. In this context we propose a composting guideline which would be used for a better waste management procedure. It includes several field scenarios.

Keywords: Landfills, Leachate, Municipal Solid Waste, Water Balance, Water Pollution.

Composite Materials from Solid Wastes and Synthetic Resin
by Ioan Ropotă, Ovidiu Dumitrescu, Marcela Muntean

Vol. 2. n. 3, pp. 430-433

Abstract - To obtain new materials with economical and ecological implication, the solid wastes as sand and cullet have been immobilized in an organic resin as a binder matrix. Various proportions of solid wastes with certain size distribution and two kind of resin (epoxy and orthophthalic polyester resin) were used in composite material, that to obtain the optimum composition from physical-mechanical point of view. All obtained composites present very good physical-mechanical properties: high hardness, good strengths at abrasion and the compressive strengths are above 90 MPa. They also have good thermal stability at high temperature variation and high stability in aggressive media.

Keywords: Blasting Sand, Cullet, Mineral Solid Wastes, Organic-mineral Composite, Waste Recycling.

Preparation of Hematite Based Humidity Sensors by Means of Electrophoretic Deposition Technique
by J. M. Tulliani, C. Baroni, J. P. Lecompte

Vol. 2. n. 3, pp. 434-439

Abstract - Hematite based humidity sensors were prepared by means of electrophoretic deposition technique (EPD). Water was used as a suspension medium for electrophoretic forming and a food gelatine was employed to stabilise the suspensions. Prior to powders additions, the gels were mechanically broken down and the suspensions were finally stirred for some minutes. Commercial alumina substrates for electronics were employed as substrates and their surfaces were graphitized, by means of a scanning electron microscope glue, to become conductive. First, a commercial iron powder was used, then an hematite one was preferred. During the EPD process, the DC tension was kept constant while the intensity died down with the increasing thickness of the formed layer. After deposition, the sensors were dried overnight at 20°C and fired at 1250°C. Gold electrodes were screen printed onto the thick films which were dried and finally heat treated at 520°C. The investigated parameters were the following: the gelatine amount, the powder concentration (2-16 g/100 mL of water), the deposition time (2 s to 5 min) and the applied tension (5-60 V). The best results were obtained with hematite powder: the sensors resistance continuously decreased starting from about 30 % relative humidity.

Keywords: Iron powder, Hematite, Electrophoretic Deposition, Gelatine, Humidity Sensors.

A New Treatment of Hydorgen Sulfide Enriched Condensates
by A. Haidar, A. Echchelh, I. Idrissi Alami, A. Chaouch

Vol. 2. n. 3, pp. 440-443

Abstract - The true issues of organizations are situated now in their capacity of facing industrial risks and unexpected events due to their activities. Hydrogen sulfide H₂S, is a highly toxic gas and a very aromatic chemical. This chemical species is especially produced by some industrial activities such as paper industries and oil refineries. The methods to eliminate them are burning treatment and stripping in a filling tower. The disadvantage of this treatment plant is the importance of corrosion of its metals by H₂S. The goal of our study is to bring alternatives in order to set up a new treatment process able to drain acid waters of condensates from the source. The tests of desulfurization by concentrated sulfuric acid combined to airing have generally given good results with a treatment yield that can reach 99%.

Keywords: Oil, Hydrogen Sulfide, Stripping, Oxidation, Active Carbon.

Extracted by CEAM 2009 - 1st International Conference on Chemical Engineering and Advanced Material)

Biocoagulants for Water and Waste Water Purification: a Review
by K. A. Yongabi

Vol. 2. n. 3, pp. 444-458

Abstract - A survey and inventory of indigenous knowledge and plants used by rural Africans to purify water was carned out vis-à-vis the inherent local water crisis cum challenges in the existing water purification technologies. The findings indicated that from time immemorial indigenous people have had to use rich knowledge base to treat their water. Plants identified were Moringa oleifera, Jatropha curcas, Pleurotus tuberregium, Citruss aurontifolia, Strynos potatorium.A review of the of the potentials of these plants coagulants with respect to turbidity removal and disinfection of water borne diseases vis-a vis the pitfalls of chemical coagulants and disinfectants such as Alum and Chlorine have been presented.Studies conclusively demonstrates that biocoagulants especially Moringa oleifera seeds are as efficient as Alum is purifying water and wastewater at low cost.The need to further develop biocoagulants as green treatment alternative for global water management admist growing global water crises is emphasized.

Keywords: Biocoagulants,Water ,Wastewater, Calum, Chlorine Moringa Oleifera.

   Diagnosis of Atmospheric Corrosion by SO₂Emitted from Oil Installations at the North of Chiapas and Center of Tabasco, Mexico
         by Raul G. Bautista-Margulis, Arturo Valdes-Manzanilla, Sergio Ramos-Herrera, Elizabeth Magaña-Villegas, Reyna L. Fócil-Monterrubio, Claudia Santander-Ferral
        Vol. 2. n. 3, pp. 459-464

Abstract - The states of Tabasco and Chiapas in Mexico concentrate a great number of important oil installations from which acid emissions have presumably affected various metallic materials and public health in many areas surrounding such installations. The objective of the present study was to determine the affected areas in the south region of Mexico, particularly Tabasco and Chiapas, due to sulfur dioxide (SO₂) emissions generated from oil installations. For the analysis of the data, three sources were employed: 1) in situ plumb peroxide spark plugs and sulfating plates, 2) SO₂ data base registered in six atmospheric monitoring stations and 3) SO₂ emission factors combined with an atmospheric dispersion model (ISC3). In accordance to the regulation ISO-9223 for sulfate deposition, the results showed that the maximum corrosion radii of the industrial type (0.04-0.09 mg m^-3) were up to 2 km in the southwest (SW) direction from the oil installations; while the maximum corrosion radii of the exceptional type (> 0.09 mg m^-3) were found to be 0.7 km in the same SW direction. Apparently, the main local communities nearby the major oil installations were not affected by SO₂ concentrations which did not exceed the Mexican environmental legislation (80 µg m-3 annual average; NOM-022-SSA1-1993). However, the values computed with the dispersion model indicated that Reforma-Chiapas was exposed from medium to high SO₂ concentrations (> 0.03 ppm).

Keywords: Atmospheric Corrosion, Sulfur Dioxide, Acid Emissions.

   Rheology on the Way from Dilute to Concentrated Emulsions
         by S. R. Derkach
        Vol. 2. n. 3, pp. 465-472

Abstract - The short review presents the analysis of the consecutive evolution of the rheology of emulsions starting from dilute systems (behavior of an individual liquid droplet in a continuous liquid phase) till the highly concentrated emulsions, in which droplets loose their spherical shape and become polygons. Along with the increase of the internal phase concentration, this is the transition from a simple Newtonian fluid via non-Newtonian fluid and up to a plastic medium demonstrating solid-like behavior at low shear stresses, yield stress threshold and non-Newtonian time-dependent properties. The special features of the emulsions rheology are related to the droplet deformation, orientation in flow, break-up and interdroplet interaction in concentrated emulsions. The similarities and differences in the rheology of suspensions and emulsions are discussed.

Keywords: Dilute suspensions, Rheology, Semi-dilute emulsions, Concentration dependence of viscosity, Concentrated emulsions, Non-Newtonian flow, Highly concentrated emulsions, Elasticity and plasticity.

Multi-Objective Optimization: Techniques and Applications in Chemical Engineering (Book Review)
reviewed by A. Mosavi

Vol. 2. n. 3, pp. 473-474

This book perfectly documents and describes the last decade worth of technical developments and is a good contribution to the application of MOO in chemical engineering and covers many different viewpoints providing an excellent treatment of the topics. The book builds up from the foundations of MOO to the presentation of its applications. In summary, this is an excellent book for everyone interested in MOO problems. Overall, this is an excellent research survey that should become a standard reference for those interested in MOO. I am very grateful to the editor for such a useful collection of many worthwhile chapters. The quality of the chapters in general makes me to recommend this book as an extremely valuable reference to both practitioners and academics.

Production Chemicals for the Oil and Gas Industry (Book Review)
reviewed by Ghada Bassioni

Vol. 2. n. 3, pp. 475-477

This book is a comprehensive and detailed account for what problems are faced in the oil and gas industry during production as oilfields age. Chemical solutions are described to be implemented topside and downhole in the oil and gas industry. Mechanistic as well as environmental aspects are described in an up-to-date manner. With this book Kelland succeeded to provide an excellent overview of oilfield production chemicals as implemented nowadays in the fields.

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