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Chemical and Biochemical Engineering Faculty Research & Creative Works

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Full-Text Articles in Biochemical and Biomolecular Engineering

Expressions For Evaluating The Possibility Of Slip At The Liquid-Solid Interface In Open Tube Capillary Electrochromatography, B. A. Grimes, Athanasios I. Liapis Jul 2003

Expressions For Evaluating The Possibility Of Slip At The Liquid-Solid Interface In Open Tube Capillary Electrochromatography, B. A. Grimes, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

In this work, expressions are constructed and solved that describe the velocity field of electroosmotic flow (EOF) in open tube capillary electrochromatography (CEC) systems when the possibility of having unequal tangential velocities at the liquid-solid interface is considered and a slip condition is employed as a boundary condition for the velocity of the EOF at the capillary wall. the coupled equations of hydrodynamics (momentum balance equation) and electrostatics (Poisson equation) are solved numerically in order to obtain the distribution of the velocity field as well as the value of the volumetric flow rate in the open tube. Also, expressions for …

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Catalytic Wet Oxidation Of Phenol By Hydrogen Peroxide Over Pillared Clay Catalyst, Jing Guo, Muthanna H. Al-Dahhan Jun 2003

Catalytic Wet Oxidation Of Phenol By Hydrogen Peroxide Over Pillared Clay Catalyst, Jing Guo, Muthanna H. Al-Dahhan

Chemical and Biochemical Engineering Faculty Research & Creative Works

Extrudates of Al-Fe Pillared Clay Catalyst Suitable for Packed-Bed Operations Are Evaluated for Wastewater Treatment Via a Wet Oxidation Process Employing Hydrogen Peroxide as the Oxidant. the Reaction Was Carried Out in a Semibatch Basket Reactor under Rather Mild Conditions. Operational Parameters Were Studied under the Following Conditions: Temperature from 25 to 90 °C, Atmospheric Pressure, Initial Phenol Concentration from 100 to 2000 Ppm of the Liquid Phase, Catalyst Loading from 0 to 10 G/L, and Input H2O2 Concentration from 0.15 to 0.6 Mol/L. under These Conditions, the Al-Fe Pillared Clay Catalyst Achieves a Total Elimination of Phenol and Significant …

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Shape-Controlled Synthesis Of Iron Oxide Nanoparticles, Yangchuan Xing, T. P. Kole, J. L. Katz Jun 2003

Shape-Controlled Synthesis Of Iron Oxide Nanoparticles, Yangchuan Xing, T. P. Kole, J. L. Katz

Chemical and Biochemical Engineering Faculty Research & Creative Works

A study on shape-controlled synthesis of iron oxide nanoparticles was presented. a specially designed counterflow diffusion flame (CDF) reactor was used to synthesize the iron oxide nanoparticles. It was observed that the properties of surface atoms on the nanoparticles are associated with the chemical environments, leading to the preferential growth of a particular crystallographic surface.

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Modeling Of The Fischer-Tropsch Synthesis In Slurry Bubble Column Reactors, Novica Rados, Muthanna H. Al-Dahhan, Milorad P. Dudukovic Apr 2003

Modeling Of The Fischer-Tropsch Synthesis In Slurry Bubble Column Reactors, Novica Rados, Muthanna H. Al-Dahhan, Milorad P. Dudukovic

Chemical and Biochemical Engineering Faculty Research & Creative Works

A Multicomponent One-Dimensional Dynamic Mathematical Model for the Reacting Slurry Systems with a Change in Gas Flow Rate Due to the Chemical Reaction is Developed. a Change in Gas Flow Rate Caused by the Chemical Reaction is Modeled using the overall Gas Mass Balance. Thus, All Relevant Chemical Species Are Included in the Model. Linear First-Order Reaction Kinetics is Considered. the Gas Phase is Modeled using the Two-Bubble Class Hydrodynamic Model. the Interaction between Small and Large Bubbles is Included as the Cross-Flow. Suspension of Liquid and Solids is Assumed to Form a Pseudo Slurry Phase. Back-Mixing in All of …

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Investigation Into The Ultrasound Setting Of Glass Ionomer Cements. Part I. Postulated Modalities, Mark R. Towler, C. M. Crowley, R. G. Hill Apr 2003

Investigation Into The Ultrasound Setting Of Glass Ionomer Cements. Part I. Postulated Modalities, Mark R. Towler, C. M. Crowley, R. G. Hill

Chemical and Biochemical Engineering Faculty Research & Creative Works

Fuji IX glass is a low phosphate, low soda containing glass which has strontia incorporated as a radio-pacifier. This glass material was analyzed during exposure to different durations of ultrasound in an attempt to determine how the glass phase reacts. Cross sections of Fuji IX cement, set both conventionally and by ultrasound, were subsequently compared by microscopy. The resultant data were analyzed in detail.

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Bubble Dynamics Measurements Using Four-Point Optical Probe, Junli Xue, Muthanna H. Al-Dahhan, M. P. Dudukovic, R. F. Mudde Jan 2003

Bubble Dynamics Measurements Using Four-Point Optical Probe, Junli Xue, Muthanna H. Al-Dahhan, M. P. Dudukovic, R. F. Mudde

Chemical and Biochemical Engineering Faculty Research & Creative Works

By Conducting an Analysis of the Measurement Errors It Was Found that Bubble Dynamics Obtained by Two-Point Probes Can Be Highly Inaccurate. a Four-Point Optical Probe with Appropriate Data Processing Algorithm Has Been Developed So that the Bubble Velocity Vector Can Be Obtained. This Probe Provides Directly the Value of Specific Gas-Liquid Interfacial Area. However, for Obtaining Accurate Values of Bubble Velocity and Size, the Four-Point Probe Must Be Calibrated by a CCD Camera at the Same Conditions. Calibration Columns Have Been Developed for This Purpose Where the Bubble Size and Velocity Can Be Varied to Calibrate the Measurements by …

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Analysis Of Photobioreactors For Culturing High-Value Microalgae And Cyanobacteria Via An Advanced Diagnostic Technique: Carpt, Hu Ping Luo, Abdenour Kemoun, Muthanna H. Al-Dahhan, J. M.Fernández Sevilla, J. L.García Sánchez, F. García Camacho, E. Molina Grima Jan 2003

Analysis Of Photobioreactors For Culturing High-Value Microalgae And Cyanobacteria Via An Advanced Diagnostic Technique: Carpt, Hu Ping Luo, Abdenour Kemoun, Muthanna H. Al-Dahhan, J. M.Fernández Sevilla, J. L.García Sánchez, F. García Camacho, E. Molina Grima

Chemical and Biochemical Engineering Faculty Research & Creative Works

Photosynthetic Algal Cultures Are a Potential Source of Many High-Value Products. in Photobioreactors (PBR), the Availability and the Intensity of the Light, Which Are Affected by the Cells' Movement, Are the Major Factors Controlling the Biomass Productivity. Hydrodynamics, Hence, Play a Significant Role in the Reactor's Performance, as They Determine Not Only the Flow Field, I.e. Liquid Flow and Mixing, Shear Stresses, Etc., But Also the Movements of the Cells. in This Work, Computer-Automated Radioactive Particle Tracking (CARPT) Technique Was Employed to Evaluate its Feasibility for Characterizing PBRs. Liquid Velocity Profiles, Cells' Movement, and the Temporal Irradiance Patterns Obtained by …

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Computer Simulations And Neutron Reflectivity Of Proteins At Interfaces, Amol A. Mungikar, Daniel Forciniti Dec 2002

Computer Simulations And Neutron Reflectivity Of Proteins At Interfaces, Amol A. Mungikar, Daniel Forciniti

Chemical and Biochemical Engineering Faculty Research & Creative Works

Computer simulations in conjunction with neutron reflectivity is an excellent combination for the study of biological materials at solid-liquid interfaces: Both techniques have excellent resolution levels (Ångströms) and they are mature. A stronger interaction between physicists and biologists will allow the use of these two approaches in topics of biological-biomedical interest.

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Novel General Expressions That Describe The Behavior Of The Height Equivalent Of A Theoretical Plate In Chromatographic Systems Involving Electrically-Driven And Pressure-Driven Flows, B. A. Grimes, S. Lüdtke, K. K. Unger, Athanasios I. Liapis Dec 2002

Novel General Expressions That Describe The Behavior Of The Height Equivalent Of A Theoretical Plate In Chromatographic Systems Involving Electrically-Driven And Pressure-Driven Flows, B. A. Grimes, S. Lüdtke, K. K. Unger, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

Novel general expressions are constructed and presented that describe the behavior of the height equivalent of a theoretical plate (plate height), H, as a function of the linear velocity, Vx, along the axis, x, of the column and the kinetic parameters that characterize the mass transfer and adsorption mechanisms in chromatographic columns. Open tube capillaries as well as columns packed with either non-porous or porous particles are studied. The porous particles could have unimodal or bimodal pore-size distributions and intraparticle convective fluid flow and pore diffusion are considered. The expressions for the plate height, H, presented in this work could …

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The Evolution And Implications Of The Concentration Profiles Of An Analyte In Porous Adsorbent Particles Packed In A Capillary Electrochromatography Column Operated In The Analytical Mode, B. A. Grimes, Athanasios I. Liapis Dec 2002

The Evolution And Implications Of The Concentration Profiles Of An Analyte In Porous Adsorbent Particles Packed In A Capillary Electrochromatography Column Operated In The Analytical Mode, B. A. Grimes, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

In this work, a mathematical model is constructed and solved to describe the propagation and dispersion of the mass wave of an analyte in a capillary electrochromatography (CEC) column packed with porous adsorbent particles and operated in the analytical mode. The evolution and dynamic behavior of the isoconcentration contours of the concentration of the analyte in the pores of the particles are presented in order to demonstrate the significant impact that the velocity of the intraparticle electroosmotic flow (EOF) encountered in CEC systems could have in reducing the overall intraparticle mass transfer resistance. It is shown that under both unretained …

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Fluoride Release From Model Glass Ionomer Cements, A. Guida, R. G. Hill, Mark R. Towler, S. Eramo Jul 2002

Fluoride Release From Model Glass Ionomer Cements, A. Guida, R. G. Hill, Mark R. Towler, S. Eramo

Chemical and Biochemical Engineering Faculty Research & Creative Works

Glass ionomer cements (GICs) are an important class of biomedical material used extensively for color matched mercury free, dental restorations. GICs can release clinically beneficial amounts of fluoride and have acceptable handling properties which make them suitable as dental restoratives. The fluoride release of model GICs produced from specially synthesized fluoro-alumino-silicate glasses was studied. Nine glasses of varying fluoride content based on 4.5SiO2-3Al2O3-1.5P2O5-(5-Z)CaO-ZCaF2 were synthesized, and cement disks were prepared from them. The glass transition temperature reduced with increasing fluorine content of the glass. Fluoride ion release was measured …

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A Preliminary Study Of An Aluminum-Free Glass Polyalkenoate Cement, Mark R. Towler, C. M. Crowley, D. Murphy, A. M.C. O'Callaghan Jul 2002

A Preliminary Study Of An Aluminum-Free Glass Polyalkenoate Cement, Mark R. Towler, C. M. Crowley, D. Murphy, A. M.C. O'Callaghan

Chemical and Biochemical Engineering Faculty Research & Creative Works

No abstract provided.

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Cfd Of Multiphase Flow In Packed-Bed Reactors: Ii. Results And Applications, Y. Jiang, M. R. Khadilkar, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic Apr 2002

Cfd Of Multiphase Flow In Packed-Bed Reactors: Ii. Results And Applications, Y. Jiang, M. R. Khadilkar, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic

Chemical and Biochemical Engineering Faculty Research & Creative Works

Numerical Simulations of Multiphase Flow using the K-Fluid CFD Model Described in Part I of This Issue Are Presented for Packed Beds at Various Operating Conditions. Both Steady-State and Unsteady-State (E.g., Periodic Operation) Feed Conditions Were Studied Numerically. Predictions of the K-Fluid CFD Model Are Comparable with the Experimental Data in the Literature for Liquid Upflow in a Cylindrical Packed Bed. in Addition to the Mean Porosity and the Longitudinally Averaged Radial Porosity Profile, the Variance of the Porosity Distribution is Needed for Predicting the Probability Density Function of the Sectional Flow Velocity. in the Trickling Flow Regime, the K-Fluid …

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Cfd Of Multiphase Flow In Packed-Bed Reactors: I. K-Fluid Modeling Issues, Y. Jiang, M. R. Khadilkar, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic Apr 2002

Cfd Of Multiphase Flow In Packed-Bed Reactors: I. K-Fluid Modeling Issues, Y. Jiang, M. R. Khadilkar, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic

Chemical and Biochemical Engineering Faculty Research & Creative Works

The Eulerian K-Fluid CFD Model Was Used to Simulate the Macroscale Multiphase Flow in Packed Beds. the Geometric Complexity of the Bed Structure is Resolved by Statistically Describing the Porosity Distribution. the Complicated Multiphase Interactions Are Computed using the Ergun Type of Formula Developed based on Bench-Scale Hydrodynamic Experiments. the Work is Presented in Two Sequential Articles. Part I Discusses Implementation Issues of the K-Fluid CFD Model for Packed Beds. the Drag Exchange Coefficients Are Obtained from the Model of Holub Et Al. for the Particle-Fluid Interfaces Xks and from the Model of Attou Et Al. (1999) for the Gas …

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Ethylene Oxide And Propylene Oxide Random Copolymer/Sodium Chloride Aqueous Two-Phase Systems: Wetting And Adsorption On Dodecyl-Agarose And Polystyrene, Yingqing Huang, Daniel Forciniti Mar 2002

Ethylene Oxide And Propylene Oxide Random Copolymer/Sodium Chloride Aqueous Two-Phase Systems: Wetting And Adsorption On Dodecyl-Agarose And Polystyrene, Yingqing Huang, Daniel Forciniti

Chemical and Biochemical Engineering Faculty Research & Creative Works

Liquid/liquid partition chromatography is a mild yet powerful separation method for a variety of biological materials. This work demonstrates that it should be feasible to immobilize an ethylene oxide-propylene oxide (EO/PO) random copolymer solution and to use a solution of NaCl equilibrated against the polymer solution as the mobile-phase (poly (EO-PO) [P(EO-PO)] and NaCl form two aqueous phases known as aqueous two-phase systems). Three random copolymers with different molecular weights and EO/PO ratios were used. Dodecyl-agarose and polystyrene were tested as possible supports. The wetting energies of the aqueous two-phase systems on these two kinds of surfaces were calculated as …

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Thermal Analysis Of Fly Ashes Sourced From European Non-Blended Coals, Kenneth T. Stanton, Mark R. Towler, Patrick Mooney, Robert G. Hill, Xavier Querol Mar 2002

Thermal Analysis Of Fly Ashes Sourced From European Non-Blended Coals, Kenneth T. Stanton, Mark R. Towler, Patrick Mooney, Robert G. Hill, Xavier Querol

Chemical and Biochemical Engineering Faculty Research & Creative Works

Fly ashes exist as a mixture of major amorphous phases and minor crystalline phases. For commercial applications, such as in concretes and for the production of zeolites, it would be desirable to be able to predict the reactivity of fly ashes. The amorphous phase dominates degradation behaviour, because glasses have a higher potential energy than the equivalent crystal structure and the variation of bond angles and distances in a glass make the bond breakage easier. Despite the large quantities of fly ash produced annually by coal-burning power plants, there have been very few studies investigating the microstructure and composition of …

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Modelling Of The Glass Phase In Fly Ashes Using Network Connectivity Theory, Mark R. Towler, Kenneth T. Stanton, Patrick Mooney, Robert G. Hill, Natalia Moreno, Xavier Querol Jan 2002

Modelling Of The Glass Phase In Fly Ashes Using Network Connectivity Theory, Mark R. Towler, Kenneth T. Stanton, Patrick Mooney, Robert G. Hill, Natalia Moreno, Xavier Querol

Chemical and Biochemical Engineering Faculty Research & Creative Works

The amorphous phase of fly ash dominates degradation behaviour because glass has a higher potential energy than the equivalent crystal structure and the variation of bond angles and distances in a glass make the bond breakage easier. It would be advantageous to predict the presence and subsequent degradability of glass on the basis of the solid-state chemistry of the fly ash. To this end, and inorganic polymer model was applied to a selection of European fly ashes to determine the value known as cross-link density (CLD). A cross-link density value of less than two implies that the material is amorphous …

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Inferring Liquid Chaotic Dynamics In Bubble Columns, M. Cassanello, F. Larachi, A. Kemoun, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic Nov 2001

Inferring Liquid Chaotic Dynamics In Bubble Columns, M. Cassanello, F. Larachi, A. Kemoun, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic

Chemical and Biochemical Engineering Faculty Research & Creative Works

Experiments Carried Out to Study the Liquid Displacements in Bubble Columns Via the Computer Automated Radioactive Particle Tracking Technique Are Analyzed by Means of Lagrangian and Qualitative Dynamics Tools. the Lagrangian Approach Yields the Detailed Motion Sequences of the Tracer as Entrained by the Fast Ascending Bubbles or by the Liquid Flow Alongside the Column Walls. the Qualitative Dynamics Tools, on the Other Hand, Provide Prima Facie Corroboration of Chaos in Liquid Motion based on an Analysis of the Volume-Averaged Kolmogorov Entropy and the Mutual Information Function. Other Features of the Chaotic Motion, the Reconstructed Attractors and the Radial and …

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Monte Carlo Simulations Of Peptide Adsorption On Solid Surfaces (Monte Carlo Simulations Of Peptide Adsorption), D. Song, Daniel Forciniti Nov 2001

Monte Carlo Simulations Of Peptide Adsorption On Solid Surfaces (Monte Carlo Simulations Of Peptide Adsorption), D. Song, Daniel Forciniti

Chemical and Biochemical Engineering Faculty Research & Creative Works

Monte Carlo (MC) simulations of a short peptide in bulk water and at charged and neutral surfaces were performed. To pursue the objective of finding whether or not the water structure around the peptide changes upon adsorption and how these changes affect the orientation of the peptide at the surface, the water structure around the peptide in the bulk and at charged and neutral surfaces were compared by analyzing the pair correlation functions (PCFs) between selected groups in the peptide and the surrounding water. In general, evidence was obtained that water is not homogeneously distributed over the peptide surface.

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The Effect Of Low Levels Of Zirconia Addition On The Mechanical Properties Of Hydroxyapatite, Mark R. Towler, I. R. Gibson Sep 2001

The Effect Of Low Levels Of Zirconia Addition On The Mechanical Properties Of Hydroxyapatite, Mark R. Towler, I. R. Gibson

Chemical and Biochemical Engineering Faculty Research & Creative Works

The effect of low levels of zirconia addition on the mechanical properties of hydroxyapatite was analyzed. Optimum amount of zirconia required to prevent decomposition of hydroxyapatite during sintering was determined. The particle size, morphology and surface area were measured and calcium to phosphorus ratio and trace element impurity content were determined by x-ray fluorescence. Low level addition of zirconia resulted in composites with better mechanical properties and minimum levels of decomposition.

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The Crystallisation Of Glasses From The Ternary Caf2-Caal2si2o8-P2 O5 System, A. Clifford, R. G. Hill, Mark R. Towler, D. J. Wood Aug 2001

The Crystallisation Of Glasses From The Ternary Caf2-Caal2si2o8-P2 O5 System, A. Clifford, R. G. Hill, Mark R. Towler, D. J. Wood

Chemical and Biochemical Engineering Faculty Research & Creative Works

A study of glasses from the ternary system CaF2-CaAl2Si2O8-P2O5 has been carried out. It has been shown that glasses with low phosphorus contents and high fluorite contents crystallise to fluorite. Fluorine reduces the glass transition temperature and is also required for the formation of fluorapatite (FAP). In the absence of fluorine in the glass no apatite phase is formed. Bulk nucleation of FAP is favoured for glasses with Ca:P ratios close to the apatite stoichiometry of 1.67 and with low crosslink densities. Thermal gravimetric analysis showed significant weight losses …

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Modeling The Ultraviolet Photodegradation Of Rigid Polyurethane Foams, C. R. Newman, Daniel Forciniti Jul 2001

Modeling The Ultraviolet Photodegradation Of Rigid Polyurethane Foams, C. R. Newman, Daniel Forciniti

Chemical and Biochemical Engineering Faculty Research & Creative Works

Before the Montreal Protocol of 1987 and the subsequent phasing-out of chlorofluorocarbons (CFCs) in industrial applications, rigid polymer foams were made using these compounds as secondary blowing agents. The CFCs remain trapped in the gaseous part of the cellular foam structure, and once discarded these foams constitute a significant reservoir for the environmental release of ozone-depleting chemicals. Environmental degradation of the foam accelerates this process. Of particular interest in this work is the degradative effect of ultraviolet (UV) light on rigid polyurethane foams. Foams were subjected to accelerated weathering conditions and then viewed with a scanning electron microscope. The thin …

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Quantitative Analysis And Synthesis Of The Electrokinetic Mass Transport And Adsorption Mechanisms Of A Charged Adsorbate In Capillary Electrochromatography Systems Employing Charged Adsorbent Particles, B. A. Grimes, Athanasios I. Liapis Jun 2001

Quantitative Analysis And Synthesis Of The Electrokinetic Mass Transport And Adsorption Mechanisms Of A Charged Adsorbate In Capillary Electrochromatography Systems Employing Charged Adsorbent Particles, B. A. Grimes, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

The dynamic mathematical model of Grimes and Liapis [J. Colloid Interf. Sci. 234 (2001) 223] for capillary electrochromatography (CEC) systems operated under frontal chromatography conditions is extended to accommodate conditions in CEC systems where a positively charged analyte is introduced into a packed capillary column by a pulse injection (analytical mode of operation) in order to determine quantitatively the electroosmotic velocity, electrostatic potential and concentration profiles of the charged species in the double layer and in the electroneutral core region of the fluid in the interstitial channels for bulk flow in the packed chromatographic column as the adsorbate adsorbs onto …

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A Preliminary Comparison Of The Mechanical Properties Of Chemically Cured And Ultrasonically Cured Glass Ionomer Cements, Using Nano-Indentation Techniques, Mark R. Towler, A. J. Bushby, R. W. Billington, R. G. Hill Jun 2001

A Preliminary Comparison Of The Mechanical Properties Of Chemically Cured And Ultrasonically Cured Glass Ionomer Cements, Using Nano-Indentation Techniques, Mark R. Towler, A. J. Bushby, R. W. Billington, R. G. Hill

Chemical and Biochemical Engineering Faculty Research & Creative Works

There is a requirement for a dental cement with properties comparable or superior to conventional glass ionomer cements (GICs) but with the command set properties of the resin modified GICs. The objective of this work was to show that the application of ultrasound to conventional Fuji IX commercial glass ionomer cement imparts a command set, whilst improving the short-term surface mechanical properties. Nano-indentation techniques were employed to highlight the improvements in hardness and creep resistance imparted to the cement through the application of ultrasound. The instant set imparted by the application of ultrasound provides improved surface hardness and creep, particularly …

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A Lagrangian Description Of Flows In Stirred Tanks Via Computer-Automated Radioactive Particle Tracking (Carpt), A. R. Rammohan, A. Kemoun, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic May 2001

A Lagrangian Description Of Flows In Stirred Tanks Via Computer-Automated Radioactive Particle Tracking (Carpt), A. R. Rammohan, A. Kemoun, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic

Chemical and Biochemical Engineering Faculty Research & Creative Works

In This Study, Computer-Automated Radioactive Particle Tracking (CARPT) is Implemented for the First Time in the Characterization of Flows in Stirred Tanks. Both the Experimental Set-Up Are Discussed. the CARPT Technique is Seen to Capture Qualitatively Most of the Important Flow Phenomena Observed in Stirred Tank Flows, Like the Two Recirculating Loops above and Below the Impeller and the Dead Zones at the Bottom of the Tank. the CARPT Data is Also Used to Extract ''Sojourn'' Time Distributions in Different Zones of the Reactor. These Distributions Are Used to Partially Quantify the Observed Dead and Active Zones in the Tank. …

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Particle Motion In Packed/Ebullated Beds By Ct And Carpt, Jinwen Chen, Novica Rados, Muthanna H. Al-Dahhan, Milorad P. Duduković, Duyen Nguyen, Krishniah Parimi May 2001

Particle Motion In Packed/Ebullated Beds By Ct And Carpt, Jinwen Chen, Novica Rados, Muthanna H. Al-Dahhan, Milorad P. Duduković, Duyen Nguyen, Krishniah Parimi

Chemical and Biochemical Engineering Faculty Research & Creative Works

Computed Tomography (CT) and Computer-Automated Radioactive Particle Tracking (CARPT) Were Used to Study the Gas Distribution and Incipient Particle Motion in a Packed/ebullated Bed in Which Gas and Liquid Are in Cocurrent Upflow. CT Scans Were Performed to Evaluate the Gas-Liquid Distributor and Gas Sparger for the Experiments, using a Perforated Plate Gas-Liquid Distributor (With 96 1-Mm Holes, Open Area of 0.1%) and a Gas Sparger (Cross-Shaped, with 16 3-Mm Holes), the Cross-Sectional Gas Holdup Distribution in the Packed/ebullated Bed Was Relatively Uniform, with Gas Holdup of About 0.11 in the Center and 0.09 Near the Wall of the Bed …

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Cfd Modeling Of Multiphase Flow Distribution In Catalytic Packed Bed Reactors: Scale Down Issues, Y. Jiang, Mohan R. Khadilkar, Muthanna H. Al-Dahhan, Milorad P. Dudukovic Mar 2001

Cfd Modeling Of Multiphase Flow Distribution In Catalytic Packed Bed Reactors: Scale Down Issues, Y. Jiang, Mohan R. Khadilkar, Muthanna H. Al-Dahhan, Milorad P. Dudukovic

Chemical and Biochemical Engineering Faculty Research & Creative Works

Flow Maldistribution in Either a Bench-Scale or Commercial Scale Packed Bed is Often Responsible for the Failure of the Scale Down Unit to Mimic the Performance of the Large Reactor. the Modeling of Multiphase Flow in a Bench-Scale Unit is Needed for Proper Interpretation of Reaction Rate Data Obtained in Such Units. Understanding the Mechanism of Flow Maldistribution is the First Step to Avoiding It. in Order to Achieve This Objective, Computational Fluid Dynamic (CFD) Simulations of Multiphase Flow under Steady State and Unsteady State Conditions in Bench-Scale Cylindrical and Rectangular Packed Beds Are Presented for the First Time. the …

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Statistical Characterization Of Macroscale Multiphase Flow Textures In Trickle Beds, Y. Jiang, M. (Muthanna) H. Al-Dahhan, M. P. Duduković Mar 2001

Statistical Characterization Of Macroscale Multiphase Flow Textures In Trickle Beds, Y. Jiang, M. (Muthanna) H. Al-Dahhan, M. P. Duduković

Chemical and Biochemical Engineering Faculty Research & Creative Works

Experimental Studies (Lutran Et Al., Ind. Engng Chem. Res. 30 (1991) 1270; Ravindra Et Al., Ind. Engng Chem. Res. 36 (1997) 5133) and Numerical Simulation (Jiang Et Al., Chem. Engng Sci. 54 (1999) 2409-2419) Lead to the Conclusion that Fluid Flow Distribution in Trickle Beds is a Function of Bed Structure (I.e. Porosity Distribution), Particle External Wetting and Inlet Superficial Velocities of the Two Fluids. in This Study, Quantitative Relationships among the above Parameters Are Developed in a Statistical Manner through a Series of Computational Fluid Dynamics Simulations. the Contribution of Capillary Forces to Liquid Maldistribution is Significant in the …

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Modeling And Analysis Of The Electrokinetic Mass Transport And Adsorption Mechanisms Of A Charged Adsorbate In Capillary Electrochromatography Systems Employing Charged Nonporous Adsorbent Particles, B. A. Grimes, Athanasios I. Liapis Feb 2001

Modeling And Analysis Of The Electrokinetic Mass Transport And Adsorption Mechanisms Of A Charged Adsorbate In Capillary Electrochromatography Systems Employing Charged Nonporous Adsorbent Particles, B. A. Grimes, Athanasios I. Liapis

Chemical and Biochemical Engineering Faculty Research & Creative Works

Mass-transfer systems based on electrokinetic phenomena (i.e., capillary electrochromatography (CEC)) have shown practical potential for becoming powerful separation methods for the biotechnology and pharmaceutical industries. A dynamic mathematical model, consisting of the momentum balance and the Poisson equations, as well as the unsteady-state continuity expressions for the cation and anion of the background electrolyte and of a positively charged analyte (adsorbate), is constructed and solved to determine quantitatively the electroosmotic velocity, the electrostatic potential, the concentration profiles of the charged species in the double layer and in the electroneutral core region of the fluid in the interstitial channels for bulk …

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Gas Holdup In A Trayed Cold-Flow Bubble Column, A. Kemoun, N. Rados, F. Li, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic', P. L. Mills, T. M. Leib, J. J. Lerou Feb 2001

Gas Holdup In A Trayed Cold-Flow Bubble Column, A. Kemoun, N. Rados, F. Li, M. (Muthanna) H. Al-Dahhan, M. P. Dudukovic', P. L. Mills, T. M. Leib, J. J. Lerou

Chemical and Biochemical Engineering Faculty Research & Creative Works

An Experimental Study Was Performed to Investigate the Effect of Sieve Trays on the Time-Averaged Gas Holdup Profiles and the overall Gas Holdup in a Cold-Flow Bubble Column that Was Scaled-Down from a Commercial Unit. Γ-Ray Computed Tomography (CT) Was Used to Scan the Column at Several Axial Locations in the Presence and Absence of Trays from Which the Local Variation of the Gas Holdup Was Extracted. the overall Gas Holdup Was Also Determined using the Same Configuration by Comparing the Expanded and Static Liquid Heights. Air and Water Were Used as the Gas-Liquid System. the Superficial Gas and Liquid …

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