Engineering Commons^™

Relative Permeability Effects On The Migration Of Steamflood Saturation Fronts, A. Erkal, Daopu Thompson Numbere

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The effects of various relative permeability-saturation relationships on the movement of water saturation fronts during steam flooding is investigated. Empirical correlations, curve fitting and spline interpolation functions are used to represent the relative permeability data. The effects of these correlations on water saturation movement and ultimately on oil recovery performance are compared. It was observed that only the spline function is able to adequately represent a given set of data throughout its saturation range. All the other correlations fit the given data well only at high water saturations and fit poorly at the low saturations. Furthermore, the correlations converge at …

The Treatment Of Vegetable Processing Waste Water Using A Pilot Scale Sequencing Batch Reactor Activated Sludge Process, Peter Hassett

Theses

The SBR process is a discontinuous, unsteady state process and has developed popularity in many countries assisted by reliable control technology for example programmable logic control. A typical SBR installation achieves equalisation, aeration and clarification of batches of wastewater on a timed sequence in one basin. This is in contrast to a volume sequenced process such as the conventional continuous stirred tank reactor where individual treatment objectives are met in separate basins. Advantages include, flexability, minimum energy input, consistent effluent quality and inhibition of filament organism growth by properly controlling substrate concentration and aeration sequences. Nitrification, denitrification and Bio-P removal …

Tomographic And Particle Tracking Studies In A Liquid-Solid Riser, Shantanu Roy, Jinwen Chen, Sailesh B. Kumar, M. (Muthanna) H. Al-Dahhan, M. P. Duduković

Chemical and Biochemical Engineering Faculty Research & Creative Works

A Liquid-Solid Circulating Fluidized Bed is a Potential Reactor of Interest in a Variety of Industrial Processes, Such as Petroleum Refining, and in the Synthesis of Fine Chemicals, Petrochemicals, and Foodstuffs. Rapid Deactivation of the Solid Catalyst in These Processes Necessitates Regeneration and Regulation of the Solids into the Riser Section in Which the Principal Reaction is Accomplished. in This Study We Show that Computer-Automated Radioactive Particle Tracking (CARPT) Can Be Used to Obtain Solids Velocity Patterns in the Riser and that Backflow of Solids Exists at the Tested Liquid Velocities. Γ-Ray Computed Tomography (CT) Reveals Slightly Higher Solids Concentrations …

Assessment Of The Effects Of High-Pressure Operation On The Liquid-Solid Mass-Transfer Coefficient In Trickle-Bed Reactors, M. (Muthanna) H. Al-Dahhan, W. Highfill, M. Friedman

Chemical and Biochemical Engineering Faculty Research & Creative Works

Trickle-Bed Reactors Are Used Widely in Industry and Are Usually Operated at High Pressure. All the Studies on Liquid-Solid Mass Transfer in Such Reactors Were Performed under Atmospheric Pressure And, Hence, the Empirical Correlations for Liquid-Solid Mass-Transfer Coefficients (K1s and K1sa) Were Developed based on Atmospheric Data. However, These Correlations Incorporate One or More of the Parameters Affected by Pressure (E.g., Liquid Holdup, Catalyst Wetting Efficiency, Pressure Drop, Gas Density). in This Work the Effects of High Pressure and High Gas Flow Rates on the Predicted Coefficients using Some of These Correlations Are Evaluated. It is Shown that There Are …

High-Pressure Trickle-Bed Reactors: A Review, Muthanna H. Al-Dahhan, Faical Larachi, Milorad P. Dudukovic, Andre Laurent

Chemical and Biochemical Engineering Faculty Research & Creative Works

A Concise Review of Relevant Experimental Observations and Modeling of High-Pressure Trickle-Bed Reactors, based on Recent Studies, is Presented. the Following Topics Are Considered: Flow Regime Transitions, Pressure Drop, Liquid Holdup, Gas-Liquid Interfacial Area and Mass-Transfer Coefficient, Catalyst Wetting Efficiency, Catalyst Dilution with Inert Fines, and Evaluation of Trickle-Bed Models for Liquid-Limited and Gas-Limited Reactions. the Effects of High-Pressure Operation, Which is of Industrial Relevance, on the Physicochemical and Fluid Dynamic Parameters Are Discussed. Empirical and Theoretical Models Developed to Account for the Effect of High Pressure on the Various Parameters and Phenomena Pertinent to the Topics Discussed Are Briefly …

Limitations And Dynamics Imposed On Multicomponent Batch Distillation By Tray Hydraulics, Keith G. Tomazi

Chemical and Biochemical Engineering Faculty Research & Creative Works

Batch distillation models incorporating a complete set of hydraulic relations, energy balances, and tray efficiencies and simpler models based upon constant molar holdup and zero holdup (the Rayleigh equation) were used to obtain distillation curves and optimal reflux policies. The approach to hydraulic limitations was monitored in the complete hydraulic model. The results indicate that during a multicomponent batch distillation the combination of the changes in the liquid composition and liquid flow rates causes the molar holdup on the trays to vary with time and, consequently, the characteristic time constant of the trays changes. The predicted composition profiles for descriptions …

A Small-Angle Neutron Scattering Study Of Γ-Crystallins Near Their Isoelectric Point, Paul Petitt, Michael Eugene Edwards, Daniel Forciniti

Chemical and Biochemical Engineering Faculty Research & Creative Works

In this paper, a small-angle neutron scattering study of γII-crystallins near their isoelectric point is presented. The experiments were carried out using protein concentrations of 5.7-85.7 mg/ml at temperatures in the range 11-60°C. The experimental data were analyzed using an ellipsoidal model for intraparticle correlations and the mean spherical approximation for interparticle correlations. Our studies revealed that γII-crystallins have a thick hydration layer, which is possibly due to the special arrangement of polar and ionic groups on their surface. The temperature scan shows that, as a result of relatively strong attractive forces, clusters of two, three, or higher oligomers are …

Ellipsometric And Raman Spectroscopic Study Of Thermally Formed Films On Titanium, E. Hristova, Lj. Arsov, Branko N. Popov, Ralph E. White

Faculty Publications

Thermal films on titanium surfaces were formed by heating titanium samples in air at atmospheric pressure. The optical constants, thickness, and structure of the formed films at various temperatures and times of heating were investigated by ellipsometry and Raman spectroscopy. The complex index of refraction and the thickness of generated films were determined by comparing the experimental loci and obtained by ellipsometric measurements with theoretical computed vs. curves. It was found that the thickness in homogeneity and porosity of formed films increase with increasing temperature and the duration of the thermal treatment. Beyond a certain critical temperature, the appearance of …

The Effects Of Organic Compounds On Inhibition Of Hydrogen Permeation Through A Mild Steel Membrane, H. A. Duarte, D. M. See, Branko N. Popov, Ralph E. White

Faculty Publications

The effectiveness of 5-(4-pyridyl)-2,7-nonadiene, and 1 phenyl-2-propyn-ol (PP) on inhibition of the hydrogen evolution reaction on a 1010 steel membrane and on the degree of hydrogen ingress into the membrane was determined. Hydrogen evolution rates and permeation currents were monitored as a function of time at different applied potentials. In the presence of 0.5 g/liter PP in the electrolyte, the hydrogen discharge and permeation current density were inhibited by 98 and95%, respectively.

Soot In Coal Combustion Systems, Thomas H. Fletcher, Jinliang Ma, Jim Rigby, Alexander L. Brown, Brent W. Webb

Faculty Publications

Soot is generated from coal when volatile matter, tar in particular, undergoes secondary reactions at high temperatures. A description of soot in coal flames allows better calculations of radiative transfer and temperatures in near-burner regions, which in turn allows more accurate predictions of NO_x formation in coal-fired furnaces. Experiments are reviewed that examine the formation, agglomeration and properties of coal-derived soot, including pyrolysis experiments and combustion experiments. This review includes the types of experiments performed, the soot yields obtained, the size of the soot particles and agglomerates, the optical properties of soot, the relationship between coal-derived soot and soot …

Release Of Inorganic Material During Coal Devolatilization, Larry L. Baxter, Reginald E. Mitchell, Thomas H. Fletcher

Faculty Publications

Experimental results presented in this paper indicate that coal devolatilization products convectively remove a fraction of the nonvolatile components of inorganic material atomically dispersed in the coal matrix. Results from three facilities burning six different coals illustrate this mechanism of ash transformation and release from coal particles. Titanium is chosen to illustrate this type of mass release from coal particles on the basis of its low volatility and mode of occurrence in the coal. During moderate rates of devolatilization (10⁴ K/s heating rate), no significant loss of titanium is noted. At more rapid rates of heating/devolatilization (10⁵ K/s) …

Governing Equations For Transport In Porous Electrodes, Pauline De Vidts, Ralph E. White

Faculty Publications

No abstract provided.

Mathematical Modeling Of Proton‐Exchange‐Membrane Fuel‐Cell Stacks, Dhanwa Thirumalai, Ralph E. White

Faculty Publications

No abstract provided.

Electrowinning Of Nonnoble Metals With Simultaneous Hydrogen Evolution At Flow-Through Porous Electrodes Iii. Time Effects, Mahmoud M. Saleh, John W Weidner, Bahgat E. El-Anadouli, Badr G. Ateya

Faculty Publications

The electrowinning of zinc from a recirculating alkaline zincate solution at a flow-through porous electrode was investigated. Experimental results were obtained to test the predictions of a mathematical model. The effects of electrolyte flow rate, cell current, and electrode thickness on the concentration-time relations and coulombic efficiency-time relations were studied. The experimental results show that the highest recovery rate was obtained at both high flow rates and cell currents. There is, however, a practical limit for increasing both the cell current and the electrolyte flow rate. Reasonable agreement between the model predictions and experimental results was obtained. A case study …

An Electrochemical Route For Making Porous Nickel Oxide Electrochemical Capacitors, Venkat Srinivasan, John W. Weidner

Faculty Publications

Porous nickel oxide films were prepared by electrochemically precipitating nickel hydroxide and heating the hydroxide in air at 300°C. The resulting nickel oxide films behave as an electrochemical capacitor with a specific capacitance of 59 F/g electrode material. These nickel oxide films maintain high utilization at high rates of discharge (i.e., high power density) and have excellent cycle life. Porous cobalt oxide films were also synthesized. Although the specific capacitances of these films are approximately one-fifth that of the nickel oxide films, the results demonstrate the versatility of fabricating a wide range of porous metal oxide films using …

Molecular-Level Modeling Of The Viscoelasticity Of Crosslinked Polymers: Effect Of Time And Temperature, Philip P. Simon, Harry J. Ploehn

Faculty Publications

We present a new molecular-level picture of chain dynamics for describing the viscoelasticity of crosslinked polymers. The associated mathematical model consists of a time-dependent momentum balance on a representative polymer segment in the crosslinked network, plus phenomenological expressions for forces acting on the segments. These include a cohesive force that accounts for intermolecular attraction, an entropic force describing the thermodynamics governing chain conformations, and a frictional force that captures the temperature dependence of relative chain motion. We treat the case of oscillatory uniaxial deformation. Solution of the model equations in the frequency domain yields the dynamic moduli as functions of …

The Effect Of Ultrasonic Frequency Upon Enhanced Killing Ofp. Aeruginosa Biofilms, Zhen Qian, Richard D. Sagers, William G. Pitt

Faculty Publications

It is widely recognized that the bacteria sequestered in a biofilm on a medical implant are much more resistant to antibiotics than their planktonic counterparts. Recent studies have shown that application of antibiotic along with low power ultrasound significantly increases the killing of planktonic bacteria by the antibiotic. Herein is reported a similar application of antibiotic and ultrasound to sessile bacteria in biofilms of Pseudomonas aeruginosa on a polyethylene substrate. Biofilm viability was measured after exposure to 12 μg/ml gentamicin sulfate and 10 mW/cm² ultrasound at frequencies of 70 kHz, 500 kHz, 2.25 MHz, and 10 MHz. The results …

Expression Of Human Protein C In Mammary Tissue Of Transgenic Mammals , William H. Velander

Department of Chemical and Biomolecular Engineering: Patents

Recombinant protein C characterized by a high percentage of active protein can be obtained in the milk of transgenic mammals that incorporate DNAs according to the present invention. Transgenic mammals of the present invention are produced by introducing into developing embryos DNA that encodes protein C, such that the DNA is stably incorporated in the DNA of germ line cells of the mature mammals and inherited in normal, mendelian fashion.

Binary Ferrihydrite Catalysts, Gerald P. Huffman, Jianmin Zhao, Zhen Fang

Chemical and Materials Engineering Faculty Patents

A method of preparing a catalyst precursor comprises dissolving an iron salt and a salt of an oxoanion forming agent, in water so that a solution of the iron salt and oxoanion forming agent salt has a ratio of oxoanion/Fe of between 0.0001:1 to 0.5:1. Next is increasing the pH of the solution to 10 by adding a strong base followed by collecting of precipitate having a binary ferrihydrite structure. A binary ferrihydrite catalyst precursor is also prepared by dissolving an iron salt in water. The solution is brought to a pH of substantially 10 to obtain ferrihydrite precipitate. The …

Surface Modifications Of Carbon Materials Used As Anode Of Lithium Ion Battery Ⅰ. Influences Of Oxidation And Reduction Pretreatment On Anode Performance, Shuhua Ma, Hanju Guo, Ji Li, Hongze Liang, Xiabin Jing, Fosong Wang

Journal of Electrochemistry

The influences of the trace oxygen containing functional groups on surface of carbon material on cell performance of carbon anode for lithium ion batteries were studied by means of the pretreament in various oxidant/reductant systems. The results showed that the rich oxygen containing functional groups impaired the cell performance of carbon material anode, and the reduction of these groups in quantity and oxidation degree can increase charge/discharge capacity and improve first charge/discharge efficiency. The reason was also discussed in the light of effects of surface organic groups on decomposition reactivity of electrolyte and formation process of surface passivating film.

Dynamics Of An Adsorbed Patch And A Model For Spreading Of Films Of Ultralow Thicknesses, Partho Neogi

Chemical and Biochemical Engineering Faculty Research & Creative Works

The dynamics of ultrathin films of liquids with vanishing 3D volatility, on solid surfaces, has been modeled by assuming that the films can be taken to be adsorbed patches spreading under surface diffusion. when the phase behavior of the adsorbed films is taken into account, it is seen that a vapor patch will spread without limits and evolve into a Gaussian profile. For a liquid film which has low 2D volatility, a patch will appear to equilibrate and the surface ahead will remain dry. This is the "pancake," a case where a wetting liquid stops spreading. the spreading kinetics is …

A Controlled Release Technique Using Microporous Membranes, Stephanie Farrell

Dissertations

A novel controlled release device based on aqueous-organic partitioning is described. The device comprises a reservoir, bounded by a microporous or porous membrane in the form of a hollow fiber or flat film. The reservoir liquid phase and the pore liquid phase are immiscible. The agent partitions between the phases at the aqueous-organic interface of the reservoir and the pore mouth, and then diffuses through the membrane pore liquid into a surrounding aqueous solution. The partition coefficient significantly influences the rate of release of the agent by reducing the driving force for diffusion across the fluid-filled membrane pore. The performance …

Vapor-Liquid Phase Equilibria Of Nonideal Fluids With A Ge-Eos Model, Socrates Ioannidis

Dissertations

This study dealt with the prediction and correlation of vapor-liquid equilibria behavior of nonideal fluids. The thermodynamic formalism of the G^E-EoS models, which combines the two traditional methods γ-Φ and Φ-Φ used so far for low and high pressure phase equilibria correlations respectively, has been combined with the 1FG^E model, based on one-fluid theory, to produce a more consistent approach to the phase equilibrium problem.

In the first part of our study we examine the predictive abilities of our model for vapor-liquid equilibria of highly nonideal fluids. The results establish the fact that the Huron-Vidal mixing rule …

Removal Of Volatile Organic Compounds From Contaminated Groundwater By Pervaporation, Sukla Chandra

Theses

Effective removal of non-aqueous phase liquid pools in groundwater and volatile organic compounds (VOCs) from contaminated soils can be achieved by surfactant flushing. This surfactant-rich ground water contains VOCs like trichloroethylene (TCE), dichloroethylene (DCE), etc. Membrane pervaporation technique is employed here to remove TCE from these micellar systems where a very high percentage of the VOC is trapped inside the micellar core. The micellar solution flows through the bore of microporous hydrophobic hollow fibers wherein the micelles break down and release the surfactants and the TCE. The TCE is then removed through the pores and a nonporous thin silicone skin …

Solids Suspension And Power Dissipation In Stirred Tanks Agitated By An Impeller Near The Tank Bottom, Ernesto Uehara-Nagamine

Theses

In this work, the effect of very small impeller clearances off the tank bottom, C, on complete solid off-bottom suspension, Njs, was investigated. Four types of impellers were used six-blade flat-disk turbine, six-blade flat-blade turbine, six-blade flat (45 degreees) pitched-blade turbine, and the high efficiency impeller Chemineer HE-3. The effects of the impeller diameter, D, tank diameter, T, and solids loading, X, were quantified. The presence of two impellers was analyzed using impellers of the same type and size.

Typically, Njs and the power consumption were found to decrease with the impeller clearance. However, for lower C/T values, a slight …

Removal Of Gasoline-Based Hydrocarbons By Vapor Permeation Membranes, Shivashanker Bagavandoss

Theses

Removal and recovery of evaporated lighter gasoline fractions can be effectively implemented by selectively permeating the hydrocarbons (HCs) and other volatile organic compounds (VOCs) from the vented air streams through nonporous hydrophobic polymeric membranes subjected to vacuum on the permeate side and then condensing these organics from the permeate. Such a vapor permeation process employing spiral-wound membranes has already been commercialized for VOCs. In this study, attention has been focused on removal of hydrocarbons from nitrogen flowing through the bore of microporous hydrophobic hollow fibers with a specially engineered nonporous silicone coating on the outside surface with a view to …

Fuel-Rich Combustion Of Ethylene And Air In A Two Stage Turbulent Flow Reactor, Tara Byrnes Salem

Theses

This thesis presents experimental and modeling results from the combustion of ethylene and air in a two stage turbulent flow reactor. This work is motivated by the continuing concern over combustion by-products. The first half of the research effort focused on the validation of the reactor as a perfectly stirred reactor and a plug flow reactor (PSR+PFR) sequence. Using four detailed reaction mechanisms, measured concentrations of carbon oxides, oxygen, and light hydrocarbon concentrations were modeled. Within the accuracy of the data, the mechanism of Mao (1995) yielded the best results. However, it was observed that the success of the reactor …

Reaction Kinetics Of Methanol And Mtbe Oxidation And Pyrolysis, Wen-Chiun Ing

Dissertations

This study presents experimental data on the decomposition of methanol in several different reaction environments - fuel lean to stoichiometric at a temperature range of 873 and 1073 K and a pressure range of I and 5 atm. Methane fuel is also added in several of the systems studied in order to provide experimental data to understand the methanol addition effect on the methane oxidation.

Computer codes: ThermCal, ThermSrt and ThermCvt have been developed for the thermal property calculations of stable molecules by the Benson group additivity method and of radicals by the NJIT hydrogen bond increment method.

Pressure dependent …

The Effectiveness Of Film Cooling In A Hypersonic Flowfield With Favorable Pressure Gradients, Julie A. Young

Mechanical & Aerospace Engineering Theses & Dissertations

The impetus of this technical document is to report results of aerothermodynamic cooling of a scramjet nozzle under favorable pressure gradients. The goals of film cooling are to protect the nozzle skin from the high enthalpy combustor flow, reduce regenerative cooling requirements, and decrease nozzle skin friction. A hypersonic nozzle configuration for which experimental data exists was selected as the basis of this numerical study. As a first step, the numerical results of film cooling along a flat plate are compared to previous literature to validate the numerical model. Subsequently, computations are performed to study the effects of varying the …

Affinity Purification Of Biologically Active Andinactive Forms Of Recombinant Human Protein C Produced In Porcine Mammary Gland, Kevin E. Van Cott, Barry Williams Department Of Chemical Engineering,Virginia Tech University, Blacksburg, Va 24061, Usa, William H. Velander, Francis C. Gwazdauskas, Tim Lee Jerome Holland Laboratory, American Red Cross, Rockville, Md 20855, Usa, Henryk Lubon, William N. Drohan

Papers in Biotechnology

Recombinant human protein C (rhPC) secreted in the milk of transgenic pigs was studied. 'Ikansgenes having different regulatory elements of the murine milk protein, whey acidic protein, were used with cDNA and genomic human protein C (hPC) DNA sequences to obtain lower and higher expressing animals. The cDNA pigs had a range of expression of about 0.1-0.5 g/l milk. Two different genomic hPC pig lines have expressed 0.3 and 1-2 g/l, respectively. The rhPC was first purified at yields greater than 60 per cent using a monoclonal antibody (mAb) to the activation site on the heavy chain of hPC. Subsequent …