Chemical Engineering Commons^™

Modeling Churn And Annular Flow Regimes In Vertical And Near-Vertical Pipes With Small And Large Diameters, Erika Viana Pagan

LSU Master's Theses

This thesis presents an improved model for gas-liquid two-phase flow in churn and annular flow regimes for small- and large-diameter in vertical and near-vertical pipes. This new model assumes that a net liquid film moves upward along the pipe wall and gas phase moves upward, occupying the majority of the central part of the pipes, and forming a gas core, in both flow regimes. The model is validated using field and laboratory experimental data from several different studies from the literature, in terms of pressure along the wellbore or bottomhole pressure for field conditions (for high-pressure flows in long pipes, …

Development Of Microfluidic Devices To Study Algal Chemotaxis And Long-Term Growth Dynamics, Benjamin Seth Roberts

LSU Master's Theses

Harmful algal blooms pose a threat to human health and the environment. Many complex factors influence their formation and development, and much is still unknown. One major influencing factor that is well-known yet poorly studied is algal chemotaxis. Many studies have examined chemotaxis in other organisms, but very little about chemotaxis in algae has been studied, largely because existing technology and assay techniques are inadequate. Microfluidics offers many possibilities for cell biology, and has been applied to the study of chemotaxis in other organisms already. These techniques can be applied to the study of algal chemotaxis as well. We present …

Expandable Proppants For Hydraulic Fracturing, Livio Yang Santos

LSU Master's Theses

Hydraulic fracturing is recognized as the primary technique to achieve economic oil and gas production from low permeability reservoirs like shale and tight-sand formations. One of the main challenges facing the oil and gas industry is maintaining the proppant functionality in the subsurface where replacement of proppant is only possible by expensive refracturing operations. Proppant crushing and proppant embedment have posed challenges for sustainable production from stimulated wells especially in soft and deep formations like Haynesville Shales. Experimental measurements show the strong impact of proppant stress and proppant embedment on reducing fracture conductivity. In this work, we introduce a new …

Extensive Sensitivity Analysis And Parallel Stochastic Global Optimization Using Radial Basis Functions Of Integrated Biorefineries Under Operational Level Uncertainties, Santiago David Salas Ortiz

LSU Master's Theses

This work presents a decision-making framework for global optimization of detailed renewable energy processes considering technological uncertainty. The critical uncertain sources are identified with an efficient computational method for global sensitivity analysis, and are obtained in two different ways, simultaneously and independently per product pathway respect to the objective function. For global optimization, the parallel stochastic response surface method developed by Regis & Shoemaker (2009) is employed. This algorithm is based on the multi-start local metric stochastic response surface method explored by the same authors (2007a). The aforementioned algorithm uses as response surface model a radial basis function (RBF) for …

The Supercritical Pyrolysis Of 1-Octene, Elizabeth Anne Hurst

LSU Master's Theses

In the pre-combustion environment, fuels for future high-speed aircrafts are predicted to take on increasing heat loads in their role as the primary coolant in order to remove excess heat from engine subsystems. While acting in this role, these fuels are expected to experience temperatures and pressures up to 700 °C and 130 atm, conditions which are supercritical for jet fuels and most hydrocarbons. Such extreme conditions can cause fuel decomposition and subsequent pyrolytic reactions, which can lead to the formation of polycyclic aromatic hydrocarbons (PAH). PAH are precursors to solids deposits that clog fuel-delivery lines, causing reduced engine performance …

The Effect Of Drying On The Release Of Small Hydrophilic Molecular Drugs From Polyelectrolyte Complex Beads, Dounsavanh Letdara

Williams Honors College, Honors Research Projects

The effects of bead composition and dryness on the release rate of small molecules, like a drug or dye, from polyelectrolyte complex (PEC) beads were studied. Release studies were performed on dried and not dried beads prepared using different PEC to drug ratios. The beads were dried for two hours, which allowed them to reach a constant weight. The beads were loaded with a dye, so their release could be detected through the visible light regime. A plate reader was used to determine the absorbance of a sample, and then the amount of dye released was determined. The data presented …

Microbiologically Influenced Corrosion: Rhamnolipid Effects, Andrea M. Wildroudt

Williams Honors College, Honors Research Projects

The purpose of this experiment was to identify if a rhamnolipid could inhibit the growth of a biofilm on carbon steel coupons and result in less corrosion activity. This type of research impacts various industries (with one of the largest being the oil and gas industry). Multiple systems with varying concentrations of the rhamnolipid were created to determine, if any, the optimum concentration to inhibit biofilm growth. The systems were created and exposed to optimum physio-chemical environments to promote SRB induced corrosion. Coupons were immersed for 28 days. Seven systems were created with varying rhamnolipid concentrations; to ensure accurate results, …

Calcium Alginate Microbead Production Via An Air Assisted Shearing Process, Ryan Loftus

Williams Honors College, Honors Research Projects

The purpose of this project was to model the size of calcium alginate microbeads produced by extruding a solution of 1.5 wt.% alginate from a syringe and needle with air shear generated from a pneumatic line flowing in an annular tube around the extrusion needle. The air shear would create microdroplets that would fall into a solution of 2 wt.% calcium chloride in water, crosslinking the droplets into beads. These microbeads can be used in drug dispersion applications or in encapsulation of cells throughout the body due to their biocompatibility. The goal was to create uniform beads that ranged from …

Separation Of Water From Ulsd Using Superhydrophobic Ps Nanofiber Mats, Alisa G. Webel

Williams Honors College, Honors Research Projects

Superhydrophobic polystyrene nanofiber membranes have potential to separate micron scale water droplets from organic due to their hydrophobicity and small pore openings. Polystyrene nanofibers were electrospun into flat sheets and cylindrical filter membranes. The fibers were crosslinked to increase strength and reduce solubility in diesel fuel. The filters were tested and the filtration efficiency was compared to their non-crosslinked counterparts. The optimal electrospinning conditions to create superhydrophobic nanofibers were found to be 20 wt. % PS fibers at 1 mL/hr. under a current of 20kV and at a distance of 20 cm away from the ground. It was found that …

Construction Of Polyurethane Fabric Nanocomposites For Use In Resistance Temperature Detectors-Effect Of Polyurethane Concentration, Multi-Walled Carbon Nanotubes, And Oxidant, Jordan M. Shaffer

Williams Honors College, Honors Research Projects

Current resistance temperature detectors (RTDs) are rigid and create pressure points when used in contact with the human body. The current RTDs can also not be used in confined areas like the inside of a prosthetic. The research done for this paper explores the possibility of creating a soft fabric like RTD that can accurately measure temperature. This RTD could be used in medical devices, be placed in prosthetic legs, and be worn for a long period of time creating no discomfort for the user. Polyurethane scaffolds were created through an electrospinning process and multiwalled carbon nanotubes were adhered to …

Investigation Of Degradation Of Amine Sorbent, Elijah Arendt

Williams Honors College, Honors Research Projects

The purpose of this study is to investigate the performance of amine-grafted sorbents, specifically when they are degraded at 120°C. This study varied the amine source and the amount of it in the sorbent. The additive type and the amount of it was also manipulated. The performance of sorbents is characterized by CO₂ capture capacity, which is the amount (in mmol) of CO₂ captured per gram of sorbent at 40°C. The best performing sorbents are ones that maintain their CO₂ capture capacity after degradation. When the amount of additive was manipulated, the sorbents containing 2% b.w. and …

Passivation And Potential Fluctuation Of Az31b Alloy In Alkaline Environments, Ana C. Bacco

Williams Honors College, Honors Research Projects

Magnesium (Mg) alloys are used in many industries because of their distinctive properties, but their high chemical reactivity and poor oxide film protection make them inferior. This project focused on investigating the effects of secondary phases and intermetallic particles (IMPs) on the corrosion behavior of AZ31B Mg alloy. The test solution was chloride free NaOH with varying pH levels between 10-14, as well as testing under deaerated conditions. The open circuit potential (OCP) measurements using AZ31B in static NaOH solutions showed potential fluctuation between approximately -1.6 V_SCE (active state) and -0.4 V_SCE (passive state) during the 24-h immersion. …

Prediction Of Vapor/Liquid Equilibrium Behavior From Quantum Mechanical Data, Marshall J. Gnap

Williams Honors College, Honors Research Projects

MOSCED (Modified Separation of Cohesive Energy Density) is a particularly attractive model for activity coefficients because it offers intuitive insights into how to tune solvent-solute interactions to achieve optimized formulations. Unfortunately, only 133 compounds have been characterized with the MOSCED method. Furthermore, there is no convenient method for extending MOSCED predictions to new compounds. The hypothesis of the present research is that the surface charge density of a molecule, once normalized over the molecule surface area, provided graphically by a σ-profile from density functional theory (DFT) computations, can be used to estimate the parameters used in the MOSCED model. DFT …

Stress Corrosion Cracking Evaluation Of Carbon Steel In Biodiesel And The Effect Of Ultrasonic Nanocrystal Surface Modification (Unsm) On 304 Stainless Steel, Josh Geyer

Williams Honors College, Honors Research Projects

The project that was performed was stress corrosion cracking (SSC) of carbon steel in biodiesel, petroleum diesel and a mixture. The project also included the effect of Ultrasonic Nanocrystal Surface Modification (UNSM) on 304 stainless steel. It included the assembly of a slow strain rate (SSR) machine and carrying out testing using the SSR machine. The assembly of the machine will require purchasing and building a stand to house the electrical equipment which includes the computer, actuator control panel and the actuator power supply. The assembly will also include designing and purchasing the connections to connect the actuator to the …

Investigation Of Parameters Enabling Admicellar Reversible Addition-Fragmentation Chain Transfer (Raft) Polymerization, Poh Lee Cheah

Electronic Theses and Dissertations

To date, enormous studies on admicellar polymerization have been recorded since the initial reports in the 1980’s. This technique which offered the advantage of using inexpensive materials and facile procedures, proven to be a successful surface modification technique. Nevertheless, one has to tailor every particular case due to the contribution of various factors in the process. Therefore, understanding the fundamentals parameters affecting the characteristics of polymer formed by admicellar polymerization have become a great interest. The effect of oxygen on the requisite amount of initiator and the polymer formed through the admicellar polymerization of styrene on silica particles was studied …

An Integrated Completion And Reservoir Modeling Methodology For Horizontal Shale Wells: A Montney Formation Example, Rashid S. Kassim, Larry K. Britt, Shari Dunn-Norman, Bryan Lang

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

The Montney Formation is one of the largest unconventional resources in North America covering from southwestern Alberta to northeast British Columbia. The Montney Formation has natural gas, natural gas liquids (NGL) and oil from conventional and unconventional reservoirs. The first multiple fractured horizontal well (MFHW) was drilled in 2005. However, since the first MFHW, different methods were proposed to optimize completion designs in the Montney Formation. Some of the optimized completions utilized the "operational effectiveness" of high-rate slick-water fracture designs while other designs utilized energized fracturing fluids. What has been missing was an integrated methodology that utilizes all available data …

Modeling Gas Inflow For Extremely Low Permeability Shale Using Cfd, Chatetha Chumkratoke

Doctoral Dissertations

"Computational fluid dynamics (CFD) has been used to model 2-D well inflow over a range of permeabilities to study the impact of various well completion strategies (Augustine, 2011). Augustine's 2-D model was subsequently extended for 3-D flow by Thepporprapakorn (2013), for gas flow in the permeability range of tight gas (0.01 mD).

This work presents a 3-D CFD model of gas inflow valid for extremely low ranges of permeability (0.00001 mD). In extremely low permeability, gas flow is complex and includes flow from fractures, flow through porous media, and diffusive gas transport. Diffusive gas transport is important when strong density …

Antibacterial Properties Of Poly (Octanediol Citrate)/Gallium-Containing Bioglass Composite Scaffolds, Ehsan Zeimaran, Sara Pourshahrestani, Ivan Djordjevic, Belinda Pingguan-Murphy, Nahrizul Adib Kadri, Anthony W. Wren, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Bioactive glasses may function as antimicrobial delivery systems through the incorporation and subsequent release of therapeutic ions. The aim of this study was to evaluate the antimicrobial properties of a series of composite scaffolds composed of poly (octanediol citrate) with increased loads of a bioactive glass that releases zinc (Zn²⁺) and gallium (Ga³⁺) ions in a controlled manner. The antibacterial activity of these scaffolds was investigated against both Gram-positive (Staphylococcus aureus) and Gram-negative (Escherichia coli) bacteria. The ability of the scaffolds to release ions and the subsequent ingress of these ions into hard tissue was evaluated …

Inorganic Hemostats: The State-Of-The-Art And Recent Advances, Sara Pourshahrestani, Ehsan Zeimaran, Ivan Djordjevic, Nahrizul Adib Kadri, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Hemorrhage is the most common cause of death both in hospitals and on the battlefield. The need for an effective hemostatic agent remains, since all injuries are not amenable to tourniquet use. There are many topical hemostatic agents and dressings available to control severe bleeding. This article reviews the most commonly used inorganic hemostats, subcategorized as zeolite and clay-based hemostats. Their hemostatic functions as well as their structural properties that are believed to induce hemostasis are discussed. The most important findings from in vitro and in vivo experiments are also covered.

Toward The Synthesis And Characterization Of Pb-Doped Zns Nanocrystals For Solar Energy Applications, Allison Durr

Online Theses and Dissertations

Efficient and affordable energy conversion and energy storage technologies are required to meet society’s increasing demands. Semiconductor nanocrystals are particularly attractive materials for solar energy conversion applications, as their tunable optoelectronic properties can be manipulated to both optimize the absorbance of solar photons and to afford desirable electronic properties. Further tunability of binary semiconductor nanocrystal systems can be realized through substitutional doping. However, doping can be difficult, as the dopants can cause significant lattice strain in the host crystals. Lead-doped ZnS nanocrystals are one promising material for the conversion of solar photons into storable fuels such as hydrogen gas. The …

Thermal Responsive Release Of A Model Drug, Rhoadmine B, From Alginate Bead System, Heather F. Fairbairn Miss

Williams Honors College, Honors Research Projects

Smart drug delivery systems have garnered increased interest in the biomedical community during recent years. Investigation into thermal, pH, and light responsive delivery systems allows for targeted drug release systems to be developed. For this project, thermal responsive release behavior was investigated for the purpose of tuning release systems to achieve 60% release in a specified time by varying the content of thermal responsive polymer. To investigate this, the release profile of a model small hydrophilic drug (rhodamine B) from polymeric alginate beads that have been modified by the addition of thermal responsive poly(N-isopropylacrylamide) (PNIPAAm). It was determined that when …

Synthesis Of Well Dispersed Supported Metal Catalysts By Strong Electrostatic Adsorption And Electroless Deposition, John Meynard Macasero Tengco

Theses and Dissertations

Enhancing the catalytic performance of heterogeneous catalysts can be done by increasing active site count as well as modification of the physico-chemical characteristics of the catalyst material. For supported metal nanoparticles this can be achieved by decreasing particle size, thus increasing dispersion or metal utilization on the surface of the particles, while modification of metal properties can be attained by addition of a secondary metal that has a strong interaction to the primary metal, beneficial for a given reaction. In addition, the accessibility of the metal surface is necessary for reliable performance of catalysts. For carbon supported catalysts, Temperature Programmed …

Rational Design And Synthesis Of Pt/Silica-Alumina Metal-Acid Bifunctional Catalysts, Jadid Ettaz Samad

Theses and Dissertations

In the domain of rational catalyst design and synthesis, Strong Electrostatic Adsorption (SEA) has been applied with tremendous potential and use. In this study, SEA method has been advanced to thick slurries as well as to mixed oxide systems with a view to synthesizing stable, active and selective catalysts fine-tuned for specific applications.

The main objective was to synthesize metal-acid bifunctional catalysts with controlled ratio and proximity between metal and acid sites in order to analyze their effects on a bifunctional reaction. At first, the difference in charging behavior of silica and alumina in solution was used to selectively deposit …

Rational Synthesis To Optimize Ruthenium-Based Biomass Conversion Catalysts, Shuo Cao

Theses and Dissertations

With worldwide petroleum resources dwindling and greenhouse gas emissions rising, it is urgent to find renewable replacements for petroleum-derived products. A biomass-derived chemical with high potential as a platform intermediate, γ-valerolactone (GVL) can be readily synthesized by hydrogenation of levulinic acid (LA), itself a common biomass intermediate, using supported Ru catalysts. Overall, vapor phase hydrogenation is more energy sensitive as the higher boiling point of LA (~245°C) and requires a high energy input, comparable to liquid phase hydrogenation, which is more economical. To date the literature on many novel biomass conversion processes such as the hydrogenation of LA to GVL …

Design And Development Of A High-Temperature High-Pressure Rolling Ball Viscometer/Densimeter And Evaluation Of Star Polymer-Solvent Mixtures, Matthew Stanton Newkirk

Theses and Dissertations

Modern automotive applications such as transmission clutch plates, combustion chambers, diesel fuel injector tips, and axle gears and friction plates operate at temperatures that can exceed 250°C and pressures of 40,000 psia. Industrial practice is to add homopolymers and copolymers to base oils to modify bulk fluid viscosity and frictional properties for these demanding applications. However, designing polymeric additives for lubricants and predicting their performance is limited by the lack of available high-temperature high-pressure (HTHP) viscosity and density data needed to test contemporary lubricity models. Thus, a major objective of this thesis is the design, development, and commissioning of a …

A Theoretical Simulation Of The Settling Of Proppants In A Hydraulic Fracturing Process, Nisreen Alseamr

Theses and Dissertations

Hydraulic fracturing is a process for the extraction of hydrocarbons from underground formations. It involves pumping a specialized fluid into the wellbore under high pressures to form and support fractures in the rock. Fracturing stimulates the well to increase the production of oil and the natural gas which are the pillars of the energy economy. Key to this process is the use of proppants, which are solid materials used to keep the fractures open. Understanding the transport of proppant particles through a fluid is important to improve the efficiency and reduce environmental impact of fracturing. An increase of the settling …

Uncertainty Quantification In Computational Catalysis, Eric Alan Walker

Theses and Dissertations

This dissertation augments the field of computational catalysis with uncertainty quantification. An efficient tool to describe the energetics and structure of atomistic systems is density functional theory (DFT). DFT may be used to understand how catalysts work although DFT is inexact in nature due to approximations necessary for computational tractability. These approximations in DFT cause uncertainty in microkinetic model results for catalytic systems. Therefore, reliable model results gained from DFT include a quantification of uncertainty. The case study to examine a systematic framework for uncertainty quantification is water-gas shift (WGS CO+H2O⇌CO2+H2) reaction by Pt/TiO2 catalyst.

Uncertainties are represented with probabilities …

Mathematical Modeling Of Transport And Corrosion Phenomenon Inside High Temperature Molten Salt Systems, Bahareh Alsadat Tavakoli Mehrabadi

Theses and Dissertations

In today's world, alternative clean methods of energy are needed to meet growing energy demands. Concentrating solar thermal power, more commonly referred to as CSP, is unique among renewable energy generators because even though it is variable, like solar photovoltaic and wind, it can easily be coupled with thermal energy storage as well as conventional fuels, making it highly dispatchable. One challenge with concentrated solar power (CSP) systems is the potential corrosion of the alloys in the receivers and heat exchangers at high-temperature (700-1000 °C), which leads to a reduction of heat transfer efficiency and influences the systems durability. The …

Development Of Novel High-Throughput Methodologies To Evaluate The Thermal Stability Of High-Temperature Thin-Film Crystals For Energy Applications, Jonathan Kenneth Bunn

Theses and Dissertations

High temperature materials are used in a variety of energy applications such as jet turbines, high temperature sensors, and solid oxide fuel cells (SOFCs). Discovery of new materials and their optimization represents a difficult engineering challenge, as the materials have to be designed to have a high figure of merit during intense high temperature operations.

The large number of engineering considerations involved in the identification and optimization of such materials makes traditional one-by-one material investigations prohibitively time consuming. The time needed to explore large parameter domains can be significantly decreased through the use of high-throughput experimentation (HTE). HTE is an …

The Oxidation And Decoration Chemistry Of Platinum And Palladium Nanoparticles On Carbon Supports, Ritubarna Banerjee

Theses and Dissertations

Ultrasmall platinum and palladium nanoparticles supported on carbon are used in a wide variety of industrial catalytic processes including hydrogenation-dehydrogenation reactions, isomerization of hydrocarbons, ammonia and formic acid decomposition, the oxidation of carbon monoxide, alcohols and ammonia, and fuel cells. This dissertation covers three aspects of the chemistry of these ultrasmall, carbon supported nanoparticles.

In the first vein of work, the oft-observed discrepancy in Pd nanoparticle size estimation between chemisorption and other methods such as STEM and XRD is explored. It is demonstrated that lower-than-expected chemisorption uptake can stem from not only residual chloride, but also from the decoration of …