Chemical Engineering Commons^™

Application Of Chemical Kinetic Modeling To Improve Design And Performance Criteria For A Practical Incineration System, Charles A. Bass Jr.

Dissertations

In this study, detailed thermo-chemical kinetics with networked ideal reactor model were applied to simulate a practical combustion system -the Secondary Combustion Chamber (SCC) of the Rotary Kiln incineration Simulator (RKIS) at the EPA facility at Research Triangle Park, NC. The networked ideal model was developed using analysis of reactor geometry, temperature profile measurements, and SO₂ tracer data provided by EPA. A computer simulation of the networked model was developed using the CHEMKIN H library. A parallel effort considered the effects of non-ideal mixing on detailed thermo-kinetic, simulations. Specifically, an alternate approach was developed to solve the Partially Stirred …

Elementary, Pressure Dependent Model For Combustion Of C1, C2 And Nitrogen Containing Hydrocarbons : Operation Of A Pilot Scale Incinerator And Model Comparison, Chad Sheng

Dissertations

A 140000 BTU/hr pilot scale incinerator has been constructed, tested and run; and an online sampling train capable of taking in situ data has been established. The continuous on-line analytical instruments include a CO analyzer, an NO/NOx analyzer and an 02 analyzer. In addition, two gas chromatographs with flame ionization detector are used to determine CH4, C2H2 + C2H4 and total hydrocarbon concentrations. Typical operating conditions are at an average 02 concentration of 6 - 8 %. The NO concentration ranged from 100 - 200 ppm. Approximately I ppm of CH.4 is also present at steady state operations.

The kinetic …

Global Expression Profiling Of Acetate-Grown Escherichia Coli, Min-Kyu Oh, Lars Rohlin, Katy Kao, James Liao

Faculty Publications

This study characterized the transcript profile of Escherichia coli in acetate cultures using DNA microarray on glass slides. Glucose-grown cultures were used as a reference. At the 95% confidence level, 354 genes were up-regulated in acetate, while 370 genes were down-regulated compared with the glucose-grown culture. Generally, more metabolic genes were up-regulated in acetate than other gene groups, while genes involved in cell replication, transcription, and translation machinery tended to be down-regulated. It appears that E. coli commits more resources to metabolism at the expense of growth when cultured in the poor carbon source. The expression profile confirms many known …

Solitary Waves And Supersonic Reaction Front In Metastable Solids, Hendrik J. Viljoen, Lee L. Lauderback, Didier Sornette

Papers in Solid Phase Dynamics

Motivated by an increasing number of remarkable experimental observations on the role of pressure and shear stress in solid reactions, explosions, and detonations, we present a simple one-dimensional model that embodies nonlinear elasticity and dispersion as well as chemical or phase transformation. This generalization of the Toda lattice provides an effective model for the description of the organization during an abrupt transformation in a solid. One of the challenges is to capture both the equilibrium degrees of freedom as well as to quantify the possible role of out-of-equilibrium perturbations. In the Toda lattice, we verify that the particle velocities converge …

Two-Photon-Excited Green Emission And Its Dichroic Shift Of Oriented Thin-Film Cds On Glass Formed By Laser Deposition, B. Ullrich, R. Schroeder, H. Sakai, A. Zhang, Stephen Z. D. Cheng

College of Polymer Science and Polymer Engineering

The photoluminescence of oriented thin-film CdS on glass formed by laser deposition was investigated employing 200 fs, 1.54 eV laser pulses at room temperature. The ultrafast excitation caused a two-photon absorption process, which results in purely green emission at the band gap. The spectra are fitted very well by the application of the van Roosbroeck-Shockley relation, density of states, and Urbach's rule demonstrating the intrinsic character of the radiative recombination. It is further shown that the energy position of the emission peak depends on the polarization of the impinging laser beam due to the dichroism of the highly oriented films. …

Effective-Medium Theories For Predicting Hydrodynamic Transport Properties Of Bidisperse Suspensions, Ashok S. Sangani, Sangkyun Koo

Biomedical and Chemical Engineering - All Scholarship

Effective-medium theories for predicting conditionally averaged velocity field and hydrodynamic transport coefficients of monodisperse suspensions are extended to bidisperse suspensions. The predictions of the theory are shown to agree very well with the results of direct numerical simulations of bidisperse suspensions with hard-sphere configurations up to volume fractions at which phase separation in bidisperse hard-sphere systems are observed.

Effects Of Welding Electropolished 316l Stainless Steel As Used In Ultra-Pure Fluid Delivery Systems For The Semiconductor And Pharmaceutical Industries, Guna S. Selvaduray, S. Trigwell

Faculty Publications

In the semiconductor and pharmaceutical industries, care is taken to prevent any contribution to product contamination or corrosion from the fluid delivery systems. Electropolished 316L stainless steel has become the industry standard due to its superior corrosion resistance. However, welding of the tubing often leads to discoloration in the heat affected zone (HAZ) which can lead to corrosion. Electropolished specimens from various lots of 316L stainless steel tubing were welded under identical parameters, but with varying concentrations of oxygen leaked into the argon purge gas during the welding, simulating on-site welding conditions. Various levels of discoloration were observed in the …

Field Analyses Of Rdx And Tce In Groundwater During A Gcw Pilot Study, Andrew Curtis Elmore, Lisa A. Travaglin, Jennifer L. Triplett

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Contaminant concentrations in groundwater are typically analyzed using traditional laboratory analytical procedures approved by the Environmental Protection Agency (EPA) or state regulatory agencies. The use of off-site laboratories provides very high-quality water quality data at a relatively high cost in terms of time and money. Yet there are many instances when it is desirable to have water quality data measured in the field. The field methods for measuring water quality typically cost much less than the corresponding laboratory methods. However, the usability of the field data may be uncertain when the results are qualitatively compared to duplicate laboratory results. Groundwater …

Extraction Of Silymarin Compounds From Milk Thistle (Silybum Marianum) Seed Using Hot, Liquid Water As The Solvent, J.F. Alvarez Barreto

Inquiry: The University of Arkansas Undergraduate Research Journal

High value specialty chemicals are usually obtained from natural products by extracting with generally regarded as safe (GRAS) solvents. Because organic solvents are quite often used, high operating and disposal costs often occur. When compared to traditional solvents, water can be viewed as an interesting alternative because of its low operating and disposal costs. Milk thistle contains compounds (taxifolin, silychristin, silydianin, silybinin A and silybinin B) that display hepatoxic protection properties. This paper examines the batch extraction of silymarin compounds from milk thistle seed meal in 50'C, 70'C, 85'C and 100'C water as a function of time. For taxifolin, silychristin, …

Ultrafast Flow Quantification With Segmented K-Space Magnetic Resonance Phase Velocity Mapping, Haosen Zhang, Sandra S. Halliburton, James R. Moore, Orlando P. Simonetti, Paulo R. Schvartzman, Richard D. White, George P. Chatzimavroudis

Chemical & Biomedical Engineering Faculty Publications

Magnetic resonance (MR) phase-velocity mapping (PVM) is routinely being used clinically to measure blood flow velocity. Conventional nonsegmented PVM is accurate but relatively slow (3–5 min per measurement). Ultrafast k-space segmented PVM offers much shorter acquisitions (on the order of seconds instead of minutes). The aim of this study was to evaluate the accuracy of segmented PVM in quantifying flow from through-plane velocity measurements. Experiments were performed using four straight tubes (inner diameter of 5.6–26.2 mm), under a variety of steady (1.7–200 ml/s) and pulsatile (6–90 ml/cycle) flow conditions. Two different segmented PVM schemes were …

Finite-Weber-Number Motions Of Bubbles Through A Nearly Inviscid Liquid, Ashok S. Sangani, Volodynmyr I. Kushch, Peter D. M. Spelt, Donald L. Koch

Biomedical and Chemical Engineering - All Scholarship

A method is described for computing the motion of bubbles through a liquid under conditions of large Reynolds and finite Weber numbers. Ellipsoidal harmonics are used to approximate the shapes of the bubbles and the flow induced by the bubbles, and a method of summing flows induced by groups of bubbles, using a fast multipole expansion technique is employed so that the computational cost increases only linearly with the number of bubbles. Several problems involving one, two and many bubbles are examined using the method. In particular, it is shown that two bubbles moving towards each other in an impurity-free, …

Biological Reduction Of Perchlorate In Ion Exchange Regenerant Solutions Containing High Salinity And Ammonium Levels, Tina M. Gingras, Jacimaria R. Batista

Civil and Environmental Engineering and Construction Faculty Research

The most promising technologies to remove perchlorate from water are ion exchange and biological reduction. Although successful, ion exchange only separates perchlorate from water; it does not eliminate it from the environment. The waste streams from these systems contain the caustic or saline regenerant solutions used in the process as well as high levels of perchlorate. Biological reduction could be used to treat the regenerant waste solutions from the ion exchange process. A treatment scheme, combining ion exchange and biodegradation, is proposed to completely remove perchlorate from the environment. Perchlorate-laden resins generate brines containing salt concentrations up to 6% or …

Water Transport In Polymer Electrolyte Membrane Electrolyzers Used To Recycle Anhydrous Hcl: I. Characterization Of Diffusion And Electro-Osmotic Drag, Sathya Motupally, Aaron J. Becker, John W. Weidner

Faculty Publications

In this paper, diffusion and electro-osmotic drag of water across Nafion® membranes in the presence of HCl are characterized. For all the measurements, one side of the Nafion membrane was in contact with liquid water and the other side with gaseous anhydrous HCl. To characterize diffusion of water, the open-circuit flux of water across a catalyst-coated Nafion 115 membrane was measured as a function of HCl flow rate and temperature at a constant cell pressure of 1 atm. Due to the nature of varying driving force for diffusion as a function of HCl flow rate, the experimental data was analyzed …

Development Of A Novel Co Tolerant Proton Exchange Membrane Fuel Cell Anode, Andrew T. Haug, Ralph E. White, John W. Weidner, Wayne Huang

Faculty Publications

Typically Pt is alloyed with metals such as Ru, Sn, or Mo to provide a more CO-tolerant, high-performance proton exchange membrane fuel cell (PEMFC) anode. In this work, a layer of carbon-supported Ru is placed between the Pt catalyst and the anode flow field to form a filter. When oxygen is added to the fuel stream, it was predicted that the slow H₂ kinetics of Ru in this filter would become an advantage compared to Pt and Pt:Ru alloy anodes, allowing a greater percentage of O₂ to oxidize adsorbed CO to CO₂. With an anode feed …

Studies On Capacity Fade Of Spinel-Based Li-Ion Batteries, Ramadass Premanand, Anand Durairajan, Bala Haran, Ralph E. White, Branko N. Popov

Faculty Publications

The performance of Cell-Batt^® Li-ion cells using nonstoichiometric spinel as the positive electrode material has been studied at different charging rates. The capacity of the cell was optimized based on varying the charging current and the end potential. Subsequent to this, the capacity fade of these batteries was studied at different charge currents. During cycling, cells were opened at intermittent cycles and extensive material and electrochemical characterization was done on the active material at both electrodes. For all charge currents, the resistance of both the electrodes does not vary significantly with cycling. This result is in contrast with cells …

Modeling The Effects Of Ion Association On Alternating Current Impedance Of Solid Polymer Electrolytes, Changqing Lin, Ralph E. White, Harry J. Ploehn

Faculty Publications

This work presents a rigorous continuum model describing the transport of ions and associated ion pairs in solid polymer electrolytes subjected to small amplitude alternating current (ac) excitation. The model treats ion association as a reversible reaction among ions and ion pairs. Dimensionless governing equations are developed from component mass balances, flux equations based on dilute solution theory, and the Poisson equation. Assuming reversible electrode reactions and electroneutrality, the model equations have an analytical solution. Further simplifications are possible in limiting cases (weak and strong association, zero and infinite frequency excitation), giving expressions consistent with previously published models. We use …

Surfactant-Induced Relative Permeability Modifications For Oil Recovery Enhancement, Subhash C. Ayirala

LSU Master's Theses

Surfactants have been considered for enhanced oil recovery by reduced oil-water interfacial tension. However, these surfactants may enhance oil recovery via wettability alteration as well. This study experimentally determines the influence of surfactant type and concentration on oil recovery, oil-water relative permeabilities and wettability in reservoir rocks. Several coreflood experiments were conducted using Yates reservoir fluids in Berea rocks and two types of surfactants (nonionic and anionic) in varying concentrations. A coreflood simulator was used to calculate oil-water relative permeabilities by history matching recovery and pressure drop measured during the corefloods. These relative permeability variations were interpreted using Craig's rules-of-thumb …

Water-Drive Gas Reservoir: Sensitivity Analysis And Simplified Prediction, Junpeng Yue

LSU Master's Theses

Water influx and well completions affect recovery from water-drive gas reservoir. Material balance, aquifer models and well inflow equations are used to examine and predict the pressure depletion, water influx, and production rates of water-drive gas reservoirs. The parameters of these simple, lumped models are estimated from simulation results using response surfaces and experimental designs for eight varying geologic and engineering factors. Eleven simulated responses (including maximum gas rate, aquifer and well constants, and water breakthrough) are analyzed using ANOVA and response models. A sensitivity analysis of aquifer productivity index, gas production factor, and sweep efficiency reveals that permeability is …

Kekf R1 Reservoir - West Delta Block 84, Plaquemines Parish, Louisiana - An Analysis And Confirmation Of Bypassed Primary And Secondary Reserves, William Clay Kimbrell

LSU Master's Theses

West Delta Block 84 Field is located off the coast of Plaquemines Parish, Louisiana. The intent of this endeavor is to prove that the two of the reservoirs, the KE-1 and KF-1, form a single communicating reservoir, the KEKF-R1; that a waterflood into the KF-1 reservoir was ineffective; that oil reserves were bypassed; and that a portion of these bypassed oil reserves can be recovered without drilling new wells. Comparisons between pre-seismic and post-seismic geological interpretations were studied, a thorough volumetric analysis was performed with a subsequent material balance calculations and a reservoir computer simulation was performed. Once a history …

Modeling Adsorption Of Cane Sugar Colorant In Packed-Bed Ion Exchangers, Hugh Anthony Broadhurst

LSU Master's Theses

The removal of cane sugar solution colorant by packed-bed ion exchangers was modeled using a linear driving force (LDF) adsorption model. Adsorption of colorant is of interest to the developers of the White Sugar Mill (WSM) process as it is a complex subject. The problem is that color is an indiscrete mixture of many components making it difficult to measure and even more challenging to model. Colorant formation was investigated using gel permeation chromatography (GPC) with the objective of developing a method to define pseudo-components representative of cane sugar solution colorants. WSM is a process for producing white sugar directly …

The Effects Of Rock And Fluids Characteristics On Reservoir Wettability, Chandra S. Vijapurapu

LSU Master's Theses

Wettability is the ability of a fluid to spread or adhere on a rock surface in the presence of other immiscible fluids. Knowledge of wettability is important to decide what production strategy needs to be employed for optimum oil recovery. Wettability is affected by rock mineralogy, rock surface roughness, and brine compositions. Previous studies have dealt with solid-liquid-vapor systems and those involving wettability characterization in solid-liquid-liquid systems have used contact angle techniques known to have reproducibility problems. In this study, a new technique called the Dual-Drop-Dual-Crystal (DDDC) Technique has been used to characterize wettability in terms of dynamic contact angles. …

A Correlation Between The Optical And Mechanical Properties Of Novel Polysilane/Polysiloxane Nanocomposites, Sungho Lee

LSU Master's Theses

Polysilanes are ¥ò-conjugated conductive polymers with a one-dimensional Si backbone and organic substituted side chains. The conventional Wurtz-type coupling reaction has been used for preparing various alkyl substituted polysilanes, i.e. poly(di-n-hexyl)silane and poly(hexylmethyl)silane. For each polysilane examples with methoxy (-OCH3) and allyl (-CH2CH=CH2) end caps have been prepared. The solution UV absorption characteristics of the polysilanes at room temperature have been measured, from which the wavelength maximum of the UV-VIS absorption and the absorptivity have been obtained. Allyl end capped polysilanes have the same wavelength maximum as methoxy end capped polysilanes. However, the absorptivities of allyl end capped polysilanes are …

Nonlinear State And Parameter Estimation And Model Predictive Control Of Nitrogen Purification Columns, Shoujun Bian

LSU Master's Theses

High-purity distillation columns are highly nonlinear systems. Nonlinear Model Predictive Control of these columns is challenging. The complexity of a first-principles model of a multi-stage distillation column, which involves a large number of differential and algebraic equations, makes Model Predictive Control computationally expensive. This thesis has focused on Nonlinear Model Predictive Control based on a simplified wave model of a distillation column; the simplified wave model consists of only one ordinary differential equation along with several algebraic equations. The predictive capability of the nonlinear wave model can be improved significantly through the application of nonlinear state estimation. Off-line estimation by …

Development Of Catalytic Processes For Aromatic Amides And Carboxylic Acids, Yujun Song

LSU Master's Theses

New catalysts were prepared and studied for: (1) a model amidation with a hindered amine, diethylamine (DEA), to N,N¡¯-diethyltoluamide (DEET); (2) the oxidation of m-xylene (MX) to DEET¡¯s alkylaromatic precursor, m-toluic acid (MTA). In both cases the goal was to reduce waste associated with current processes. Thermodynamic analyses showed that the amidation to produce DEET from MTA and DEA was an equilibrium limited reaction with equilibrium constants (Ke) less than 41 at temperatures below 320¡ÆC. The kinetics on silica-supported titanium (¥³) (triethanolaminato)-isopropoxide (Tyzor TE), calcium hydroxyapatites and silica supported tungsten heteropolyacids were studied using a continuous reactor. Both porous hydroxyapatites …

Geostatistical Shale Models For A Deltaic Reservoir Analog: From 3d Gpr Data To 3d Flow Modeling, Hongmei Li

LSU Master's Theses

The effects of shales on fluid flow in marine-influenced lower delta-plain distributary channel deposits are investigated using a three-dimensional ground-penetrating radar (GPR) data volume from the Cretaceous-age Ferron sandstone at Corbula Gulch in central Utah, USA. Using interpreted GPR data, we formulate a geostatistical model of the dimensions, orientations, and geometries of the internal structure from the subaerial exposure surface down to about 12 m depth. The correlation function between GPR instantaneous amplitude and shale index is built after statistical calibration of the GPR attributes (amplitude) with well data (gamma ray logs). Shale statistics are computed from this correlation function. …

Development Of A Magnetite Tracer Protocol For Seasonal Measurement Of Bed Sediment Biodiffusion Coefficients, Paul D. Libbers

LSU Master's Theses

This thesis describes the development of a particle tracer technique for making short-term, in situ measurements of aquatic bed sediment biodiffusion coefficients. The bioturbation process in the upper sediment layers of streams, lakes, estuaries, and the marine environment moves particles and porewater. When present, organic chemicals, metals, colloids, etc., are transported across these layers and exchanges may occur at the sediment-water interface. Fickian biodiffusion coefficients that characterize such particle movements, Db (cm2/yr), are used for assessing chemical diagenesis rates and contaminant fluxes and are specific to each site. Chemical Fate and Transport (CFaT) models, developed for tracking contaminants in aquatic …

Evaluation Of The Hydrocarbon Potential In Low-Salinity Shaly Sand, Fnu Kurniawan

LSU Master's Theses

This research utilizes reservoir data from an oilfield in Indonesia, which is characterized by shaly sand and low salinity formation water. Both low salinity and shaliness reduce the resistivity contrast between oil and water. The aim of this research was to build a comprehensive interpretation algorithm to evaluate the shaly-sand reservoir in a low salinity formation water using limited well log data. Shaly-sand interpretation is still evolving with numerous researchers conducting investigations of the clay minerals effect on rock conductivity through theoretical and experimental approach. These investigations can be loosely divided into either Fractional Shale Volume models or the Cation …

Slab-Geometry Molecular Dynamics Simulations: Development And Application To Calculation Of Activity Coefficients, Interfacial Electrochemistry, And Ion Channel Transport, Paul S. Crozier

Theses and Dissertations

Methods of slab-geometry molecular dynamics computer simulation were tested, compared, and applied to the prediction of activity coefficients, interfacial electrochemistry characterization, and ion transport through a model biological channel-membrane structure. The charged-sheets, 2-D Ewald, corrected 3-D Ewald, and corrected particle-particle-particle-mesh (P3M) methods were compared for efficiency and applicability to slab-geometry electrolyte systems with discrete water molecules. The P3M method was preferred for long-range force calculation in the problems of interest and was used throughout.

The osmotic molecular dynamics method (OMD) was applied to the prediction of liquid mixture activity coefficients for six binary systems: methanol/n-hexane, n-hexane/n-pentane, methanol/water, chloroform/acetone, n-hexane/chloroform, methanol/ …

Compostability Of Degradable Plastics And Its Use In Solid Waste Disposal / Putri Nadzrul Faizura Bt Megat Khamaruddin., Putri Nadzrul Faizura Megat Khamaruddin

Student Works (2000-2009)

Plastic waste generation and quantity generated is a growing concern in many countries including Malaysia. Plastic waste contributes the third highest waste volume in Malaysian municipal solid waste (MSW) next to putrescible waste and paper. ln the year 2000, plastic waste in MSW of Kuala Lumpur was 24.4% by weight from the MSW and most of the plastic waste was dumped into landfills. Landfills in Malaysia are reducing in its useful life as the amount of waste generated is growing every year by 2% and they have become an undesirable option of getting rid of plastic waste because of the …

Remediation Of Trapped Free-Phase Lnapl, T. M. Whitworth, Andrew Curtis Elmore

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Free-phase light nonaqueous phase liquids (LNAPLs) may be trapped in certain stratigraphic and structural features near or at contaminated sites due to seasonal or other variations in the water table elevation. The purpose of this article is to point out particular subsurface conditions that are conducive to trapping of free-phase LNAPLs and to suggest approaches to remediating LNAPL-contaminated sites exhibiting similar subsurface geometry and stratigraphy. To trap free-phase LNAPL, a structure must have, in addition to closed contours, an upper boundary with pores small enough so that the LNAPL will not enter them. This boundary usually consists of clay-rich sediments. …