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International Review of Chemical Engineering (Rapid Communications) - July 2011 (Vol. 3 N. 4) - Papers

Numerical Modeling of Nanofluid Heat Transfer in a Pipe (Invited Paper)
Engineering and Economical Feasibility Analysis of Butanol Production Using Corn as Feedstock
The Chemical Synthesis with Similtanous Doping of a Conducting Polymer: the Polyaniline (PANI)
Analyzing Flow Hydrodynamics in Stirred Tank with CD-6 and Rushton Impeller
Different Types of Fuel Produce from Municipal Solid Mixed Waste Plastics by Fractional Distillation with Thermal Cracking Process
Discrete Time Space Model-Based Learning for Chlorine Dosing Design of Drinking Water
Preparation of Micro- and Mesoporous Activated Carbons from Olive-Tree Wood by Physical and Chemical Activation
Tuning of PI Controllers with Application to a Distillation Column: a Direct Synthesis Approach
Chemical Composition of Essential Oil from Lepidium meyenii Walp. in China
Nanofiltration Application for Concentrating Aqueous Waste Stream to Recover Sodium Sulphate
Effects of EDTA and Titania in the HDS of DBT
Numerical Solution and Validation Concerning a Descriptive Model of a Simultaneous Heat and Mass Transfer Process

Modeling and Simulation of Catalytic Reactors for Petroleum Refining (Book Review)

International Review of Chemical Engineering (Rapid Communications) - Papers

Numerical Modeling of Nanofluid Heat Transfer in a Pipe
by Zohreh Mansoori, Majid Saffar-Avval, Shiva Taghavi

Vol. 3. n. 4, pp. 419-426

Abstract - An Eulerian-Eulerian approach by considering the slip velocity between solid and liquid is used to model heat transfer of a nanofluid in a pipe with a circular cross-section. The Brownian diffusion and the thermophoresis are considered as representative of the slip between the phases. For this case, a two-component, four-equation model is considered (two continuity equations, momentum, and energy equations); the well-known k-ε model is used for turbulence modeling. Two different approaches are used to account the thermal turbulence. The first approach, suggests the thermophysical properties of nanofluid as a function of volume fraction of suspended particles only. In this case, the turbulent Prandtl number allows finding the turbulent thermal diffusion coefficient. With the second approach, the nanofluid viscosity is considered to be a function of both the temperature and the volume fraction of the particles. Consequently, increasing in either the Reynolds number or the particle volume fraction, results in augmented convective heat transfer coefficient.

Keywords: Nanofluid, Brownian Diffusion, Thermophoresis, Turbulent Prandtl Number.

Engineering and Economical Feasibility Analysis of Butanol Production Using Corn as Feedstock
by Anwar A. Aglan, Essam A. Ibrahim

Vol. 3. n. 4, pp. 427-433

Abstract - Butanol is gaining attention in the biofuel market due to its high energy content and ability to be blended with gasoline at any ratio. This paper analyzes the chemical processes, size relevant equipment and performs life cycle cost analysis on an integrated chemical plant to produce butanol by fermentation of corn. A plant with an output of 50 MM gal of butanol/yr is used as a case study for the current investigation. An overall framework for material and energy balances, equipment size and cost, utility consumption, economical analysis and environmental issues are presented. The underlying principle that drives the entire plant design is the fact that Acetone, Butanol and Ethanol (ABE) can only be produced to a titer of 33 g/L in the fermentation train. This dictates the size of the fermenters required, as well as causing a huge amount of water to be required and processed. It was found that the capital cost of the plant is about $112 million and the operating costs were found to be $189 million. Using a Lang factor of 4 and neglecting any additional operating costs or general expenses the plant was found to have a payback period of about 9 years.

Keywords: Butanol, ABE Fermentation.

The Chemical Synthesis with Similtanous Doping of a Conducting Polymer: the Polyaniline (PANI)
by Y. Nouar, A. Bensedira, S. Madani

Vol. 3. n. 4, pp. 434-439

Abstract - The present work focuses on the preparation and characterization of conducting polymer. From a preliminary work and to find the optimum conditions for obtaining polyaniline (PANI) nanoparticles with the best conductivity, we selected the polyaniline synthesized in diluted phase, oxidized by (NH₄)₂S₂O⁸ and doped by HCl, H₂SO₄ or H₃PO₄. The properties of the synthesized polyanilines were investigated by FTIR analysis, differential scanning calorimetry (DSC), thermogravimetry (ATG), X-rays diffraction (DRX) and characterized by electrical conductivity. It was observed that the electrical conductivity of polyaniline increases with the increase in the concentration of doping agent from 0.2 to 1 M. DRX charts allowed us to deduct approximately the grains size of PANI. It was observed that the smallest grains sizes are obtained with the different doping agents (H₃PO₄, H₂SO₄ and HCl). Also, the most conductive PANI which is obtained with HCl provides intermediate grains sizes.

Keywords: Conducting Polymers, Chemical Synthesis, Doping, Polyaniline.

Analyzing Flow Hydrodynamics in Stirred Tank with CD-6 and Rushton Impeller
by Thiyam Tamphasana Devi, Bimlesh Kumar

Vol. 3. n. 4, pp. 440-448

Abstract - Impeller-stirred tanks play a very important role throughout chemical, bio-technical and other process industries. Proper designing of such systems require the detail mechanism of the hydrodynamics of fluid inside the stirred tank. Generally Rusthon turbine (flat blade disc turbine) is being employed in such processes. The study on the non standard (curved blade disc turbine, i.e., CD-6) impeller is found very less in literature as compare with standard impeller like Rushton turbine. Present wok using computationally fluid dynamics (CFD) simulation compares the performance of flow hydrodynamics of CD-6 impeller and Rushton turbine. The results of the CFD simulation was compared with published literature studied on Rushton turbine. Multiple reference frames (MRF) impeller model and Realizable k-ε turbulence model for Rushton turbine and CD-6 coupled with first order upwind differencing discretization schemes have been applied in this simulation. CFD Simulation predictes more turbulent kinetic energy dissipation near the vicinity of impeller in CD-6 impeller than the Rushton turbine, which shows the better mixing property of CD-6 impeller.

Keywords: Hydrodynamics, Stirred Tank, CFD, Rushton Turbine, CD-6, MRF, Realizable K-Ε Turbulence Model.

Different Types of Fuel Produce from Municipal Solid Mixed Waste Plastics by Fractional Distillation with Thermal Cracking Process
by Moinuddin Sarker, Mohammad Mamunor Rashid, Mohammed Molla, Md. Sadikur Rahman

Vol. 3. n. 4, pp. 449-456

Abstract - Starting of Plastics invention has many uses and application. If we study the background of plastics we noticed it’s generated from crude oil. All over the world plastics have become more popular goods in many aspects of house hold supplies such as food, milk, juice and detergent container etc. In developed and in undeveloped countries plastics are utilized as an alternative of expensive metal e.g. purposes of making truck and car body, in many buildings and corporate office inside partitions. Plastics have certain durability that how long it can restrain as a compatible. Consequently after use all kinds of plastics are discarded in the landfill. Plastics are non-biodegradable and its make hazardous impacts into atmosphere also incineration produces poisonous gases such as CO, CO₂, NO_X (Oxides of Nitrogen) and many types of other gases (Chlorofluorocarbon CFC, SO₂) that causes of green house effect and ozone layer depletion. Landfills are another difficulty because of population dense in many region and lack of empty land spaces. Landfill is also not environmentally friendly it’s concurrent with incineration. Dumping is very expensive and its rare facility to get dumping space in the land. Dumping makes the land infertile and rigorously polluted underground aqueous reservoir. Plastics thrown away in to the ocean, river and canal have devastating effect on water system and eco-system including minimizes dissolve oxygen level in water that leads to eco-animal life in danger and extinction.

Keywords: Waste Plastic, Fuel, Thermal Cracking, Fractional Distillation, GC/MS.

Discrete Time Space Model-Based Learning for Chlorine Dosing Design of Drinking Water
by Abrar Muslim

Vol. 3. n. 4, pp. 457-462

Abstract - An ideal drinking water distribution system must supply safe drinking water with free chlorine residual at a required concentration level. Meanwhile free chlorine residual is consumed in the bulk liquid phase and at the pipes wall of drinking water distribution system as the result of chemical reactions. Learning based on Discrete Time Space Model was utilized for free chlorine residual dynamic transport in the main pipes simulated using Matlab 7.0.1 in order to develop a design of chlorine dosing. The Discrete Time Space Model-based learning objective was to generate an algorithm for off-line control of free chlorine residual with the constraint of the lower limit of 0.24 mg/l and the upper limit of 0.56 mg/l. Data from reference plant was used to cross-check the reliability of the off-line control algorithm. As the result, a model based chlorine dosing design was considerable technique for application.

Keywords: Free Chlorine Residual, Discrete Time Space Model, Learning, Off-Line Control.

   Preparation of Micro- and Mesoporous Activated Carbons from Olive-Tree Wood by Physical and Chemical Activation
         by Mounia Al Bahri, Mostafa Stitou, Eduardo M. Cuerda-Correa, María F. Alexandre-Franco, Carmen Fernández-González, Antonio Macías-García, Vicente Gómez-Serrano
         Vol. 3. n. 4, pp. 463-473

Abstract - Micro- and mesoporous activated carbons have been prepared from olive-tree wood by means of physical and chemical activation. In the first case the activating agent was air, whereas phosphoric acid was chosen to carry out the chemical activation procedure. The method used for the preparation of the samples noticeably influences the development of surface area and porous texture of the activated carbons. The physical activation of the raw material leads to mainly microporous carbons that exhibit a moderate development of specific surface area (SBET = 132 m² g⁻¹ ) and porous texture. Carbons prepared by chemical activation with phosphoric acid show large S_BET (449 m² g⁻¹ - 1098 m² g⁻¹) and a well-developed mesoporous texture (up to 0.75 cm³ g⁻¹). Nevertheless, depending on the temperature at which the carbonization process takes place remarkable differences in terms of S_BET and pore volumes may be observed.

Keywords: Olive-Tree Wood, Activated Carbons, Physical Activation, Chemical Activation.

Tuning of PI Controllers with Application to a Distillation Column: a Direct Synthesis Approach
by Saeed Tavakoli, Jafar Sadeghi

Vol. 3. n. 4, pp. 474-477

Abstract - Based on the direct synthesis approach, this paper presents a simple but effective PI tuning method. In the direct synthesis method, the controller is designed in such a way that a desired closed-loop transfer function is obtained. First, the process is approximated by an over-damped second-order plus dead time model. Considering a step change in the setpoint, it is shown that the desired step response can be obtained by suitably choosing the controller gain. Also, a good trade-off between performance and robustness can be achieved if the controller gain is appropriately adjusted. Considering two illustrative examples, including non-minimum phase high order process as well as a practical application, simulation results confirm that the proposed technique results in satisfying the design requirements well.

Keywords: PI Control, Direct Synthesis Method, Distillation Column.

Chemical Composition of Essential Oil from Lepidium meyenii Walp. in China
by Liwei Wang, Bing Zhao

Vol. 3. n. 4, pp. 478-480

Abstract - This study investigated the chemical composition of essential oil from Lepidium meyenii (maca) ecotypes growing in Lijiang, China. GC-MS analysis of the essential oil revealed the presence of butanol, ethyl acetate and benzyl isothiocyanate as the major components of yellow maca. Red maca mainly contained butanol, heptacosane, and pentacosane. The different composition of essential oil between yellow maca and red maca could be most probably explained by the variability of the plant ecotypes.

Keywords: Chemical Composition, Essential Oil, Lepidium Meyenii Walp.

Nanofiltration Application for Concentrating Aqueous Waste Stream to Recover Sodium Sulphate
by R. S. Gawaad, S. K. Sharma, S. S. Sambi

Vol. 3. n. 4, pp. 481-486

Abstract - Sodium sulphate is one of most important salts of sodium which is mainly used in the manufacture of detergents, Kraft paper, glass, sodium salts, ceramic glazes, pharmaceuticals, dyeing of textile fibers etc.. Part of its requirement is met from by-products of manufacturing processes like Aluminium silicate, rayon etc. Presently, evaporation followed by crystallization is the preferred technique for recovery of the salt. This technique becomes uneconomical when the waste water has low concentration of the salt. There is a need to develop new techniques for economical concentration of sodium sulphate. Keeping this in mind efforts were made to test the performance of two commercial CSM membranes Model Nos. NE-1812-70 and RE 1812-50 for concentrating the waste water stream. The results show that waste water stream could be concentrated, at pressure of 25 bar, up to 14.1% at permeate flux of 2.08L-min^-1-m^-2 with NE-1812-70 membrane compared to 9.29% at permeate flux of 0.62 L-min^-1-m^-2 with RE 1812-50 membrane.

Keywords: Nanofiltration, Membrane Separation, Sodium Sulphate, Aluminium Silicate.

Effects of EDTA and Titania in the HDS of DBT
by Peyman Moradi, Matin Parvari

Vol. 3. n. 4, pp. 487-492

Abstract - A series of TiO₂-Al₂O₃ binary oxide supports were prepared by different methods and raw materials, namely using aluminum sulfate and titanium chloride (S₁), γ-Alumina and titanium isopropoxide (S₂), and a commercial boehmite and titanium isopropoxide (S₃). Ethylenediaminetetraacetic acid (EDTA) with different EDTA/Co mole ratios (0.6, 1.2 and 1.8) was used as a chelating agent during the preparation of CoMo/Al₂O₃-TiO₂. The samples were analyzed by XRD, BET, FT-IR and NH₃-TPD experiments and tested on the dibenzothiophene (DBT) hydrodesulfurization (HDS) reaction. The results showed that the catalyst supported on S₂ with EDTA/Co mole ratio of 1.2 had a HDS activity (in pseudo first order kinetic constant basis) value ~2.7 times higher to that of CoMo/Al₂O₃ catalyst.

Keywords: Hydrodesulfurization, Ethylenediaminetetraacetic Acid, Al₂O₃-TiO₂, Preparation Method.

Numerical Solution and Validation Concerning a Descriptive Model of a Simultaneous Heat and Mass Transfer Process
by Luis T. Villa, María C. Sanziel, Angélica C. Bouciguez

Vol. 3. n. 4, pp. 493-498

Abstract - This paper deals with the numerical solution of an initial moving boundary problem (IMBVP) arising from a simplified version of a free boundary problem (IFBVP) which was formulated in another paper, as a mathematical model of heat and moisture transfer during the bubbling stage of an immersion frying process of stick shaped natural potato. The IMBVP was solved numerically using an explicit finite difference method, immobilizing the moving boundary through the use of the well known Landau transformation. The simulation output provides the temperature and moisture profiles and the amount of free moisture lost by vaporization. The model was validated by comparing the predicted results with experimental data. A good agreement was obtained.

Keywords: Potato Immersion Frying, Free-Moving Boundary Models, Moisture Desorption Front, Numerical Solution.

Modeling and Simulation of Catalytic Reactors for Petroleum Refining (Book Review)
Reviewed by Abdullah A. Shaikh

Vol. 3. n. 4, p. 499

This new book is intended to describe in detail the science and art of modeling some of the long-established and traditional heterogeneous reactive processes in the chemical process industries. This is a challenging task, considering that most reactive processes in the petroleum-refining industry are notoriously difficult to model and simulate for many reasons. The reasons include issues that modeler must deal with: multi-phase catalytic systems; solid catalysts prone to deactivation; lumped groups of a large number of compounds (e.g., LCO, gasoline); and lack of reliable hydrodynamic properties in complex reactor configurations.