Chemical Engineering Commons^™

Autothermal Non-Catalytic Reformation Of Jet Fuel In A Supercritical Water Medium, Jason W. Picou

Masters Theses

"The non-catalytic reformation of jet fuel using supercritical water was studied in a specially designed 0.4-L Haynes Alloy 230 tubular reactor. Experiments were performed at a constant pressure of 24.1 MPa, a temperature of 770°C, and at a constant water-to fuel ratio of fifteen-to-one by mass with various space times and oxygen flow rates. The experiments were conducted with and without air flow so as to examine the effects of the concurrent partial oxidation on the overall reformation process. The reactor effluent gas consisted of hydrogen, nitrogen, carbon dioxide, carbon monoxide, methane and ethane. Increasing space time increases the extent …

Synthesis Of Iron Oxide Nanoparticles In A Counterflow Diffusion Flame Reactor, Hector Enrique Ruiz

Masters Theses

"A Counterflow Diffusion Flame (CDF) reactor was used to produce iron oxide nanoparticles. The experimental work was performed to study synthesis conditions and characterize the iron oxide nanoparticles. The parameters studied are those that control the flame structure, namely, gas flow rates and vacuum; other parameters include the precursor volume flow rate, and the relative location and temperature of the collecting probe inside the flame. Hexagonal nanoparticles were the most commonly observed shape. Hexagonal-shaped nanoparticles are mainly formed under stoichiometric conditions and with a high temperature profile in the flame. Cubic nanoparticles were also observed. The main parameter for the …

Removal Of Heavy Metals From Electroplating Wastewater Using Rice Husk And Coconut Coir, Frency Mathew

Masters Theses

"Heavy metal toxicity due to industrial wastewater has been a threat to the environment for the past many decades, especially in the developing countries such as India, China and Thailand where cost effectiveness of the removal process is a major factor. In this research, the effectiveness of two natural adsorbents, rice husk (RH) and coconut coir (CC), which are cheaply available in these countries for the removal of heavy metals from electroplating wastewaters were studied"--Abstract, page iii.

Sublethal And Killing Effects Of Atmospheric-Pressure, Nonthermal Plasma On Eukaryotic Microalgae In Aqueous Media, Ying Zhong Tang, Xin Pei Lu, Mounir Laroussi, Fred C. Dobbs

OES Faculty Publications

In-depth studies on the interaction of nonthermal plasmas with microorganisms usually focus on bacteria; only little attention has been given to their effects on more complex eukaryotic cells. We report here nonthermal plasma's effects on cell motility, viability staining, and morphology of eukaryotic microalgae, with three marine dinoflagellates and a marine diatom as major targets. The effects on motility and viability staining depended on the time of exposure to plasma and the species of microalgae. We observed a strong pH decrease in aqueous samples (marine and freshwater algal cultures, their culture media, and deionized water) after exposure to plasma, and …

Identification Of Polycyclic Aromatic Hydrocarbons In The Supercritical Pyrolysis Products Of Synthetic Jet Fuel S-8 And Methylcyclohexane, Jorge Oswaldo Ona Ruales

LSU Doctoral Dissertations

Inside the pre-combustor fuel lines of future high-speed aircraft, at supercritical conditions, hydrocarbon fuels react to form polycyclic aromatic hydrocarbons (PAH) and eventually solid deposits. These deposits can block fuel lines and lead to undesirable effects for the aircraft operation. To elucidate the pathways that lead to the formation of PAH (and ultimately, solids formation), the identification of the PAH products generated by the reactions is critical. In this context, two fuels have been analyzed: synthetic jet fuel S-8 and methylcyclohexane. Synthetic jet fuel S-8 is important due to its non-petroleum origin. Methylcyclohexane is important due to its endothermic behavior. …

Adsorption And Photochemical Transformation Of Polycyclic Aromatic Hydrocarbons On Atmospheric Water Films, Jing Chen

LSU Doctoral Dissertations

Atmospheric water films affect the processing of chemicals in the atmosphere and have potential effects on human health and the environment. In this work, adsorption and photochemical transformations of gas-phase PAHs were studied in a flow-tube photo-reactor with a view to understanding the behavior of gas-phase PAHs occurring in thin water films such as those of aerosols and fog. Naphthalene and phenanthrene were chosen as model PAHs for this study. Bulk water-air and air-to-interface partition constants of naphthalene and phenanthrene were estimated from the experiments based on the dependence of the equilibrium uptake on the water film thickness. Theoretical computations …

Vibrations For Improving Multiphase Contact, Yogesh G. Waghmare

LSU Doctoral Dissertations

Present work demonstrates the use of vibrations to enhance performance of two multi-phase contacting systems: a bubble column for gas-liquid contacting (physical absorption) and a Piston Oscillating Monolith Reactor (POMR) for gas-liquid-solid contacting (catalytic reactions). In a bubble column reactor, enhancements of mass transfer coefficient and gas hold up were experimentally studied for the air-water system. Mass transfer coefficient enhancements up to 500% and gas hold-up improvements up to 200% were achieved under the application of low amplitude (0.5-2.5 mm) vibration at low frequencies (0-25 Hz). A fundamental theory was developed from first principles to explain these enhancements. The theory …

Catalytic Synthesis Of Ethanol From Biomass-Derived Syngas, Adefemi Adelanwa Egbebi

LSU Doctoral Dissertations

Syngas produced by gasification of biomass or coal can be converted directly to ethanol and higher alcohols by processes based on heterogeneous catalysts. Ethanol can be used as a neat fuel or fuel additive or as a hydrogen carrier. Rhodium-based catalysts have been found to be most selective for the formation of C₂ oxygenates from the hydrogenation of CO when suitably promoted. Here, we explore the effects of Mn, Fe, and Li promoters on Rh/TiO₂. Rh-TiO₂, Rh-Li/TiO₂, Rh-Mn/TiO₂, Rh-Mn-Li/TiO₂ and Rh-Mn-Li-Fe/TiO₂ catalysts were tested for the hydrogenation of CO …

Reservoir Characterization Using Seismic Inversion Data, Subhash Kalla

LSU Doctoral Dissertations

Reservoir architecture may be inferred from analogs and geologic concepts, seismic surveys, and well data. Stochastically inverted seismic data are uninformative about meter-scale features, but aid downscaling by constraining coarse-scale interval properties such as total thickness and average porosity. Well data reveal detailed facies and vertical trends (and may indicate lateral trends), but cannot specify intrawell stratal geometry. Consistent geomodels can be generated for flow simulation by systematically considering the precision and density of different data. Because seismic inversion, conceptual stacking, and lateral variability of the facies are uncertain, stochastic ensembles of geomodels are needed to capture variability.

In this …

Cluster Kinetics Modeling Of Glassforming Materials, Lisa Ann Brenskelle

LSU Doctoral Dissertations

In this work, a new model relating temperature and pressure to dielectric relaxation or viscosity of a glassformer is developed. The model is based upon cluster kinetics, reaction-like mechanisms describing interactions between glassformer monomers and their clusters. Mathematical solutions of population balance equations for monomer and cluster lead to molar concentrations in terms of rate coefficients of the reaction-like mechanisms. These are then related to viscosity or dielectric relaxation time through free volume theory. The resulting equations are tested against data for a variety of pure glassformers, fragile, non-fragile, large, and small molecules over a wide range of temperatures, pressures, …

Heterogeneous Catalyzed Macromolecular Hydrogenations In Oscillating Systems, Alan Bussard

LSU Doctoral Dissertations

An examination of novel oscillatory (alternating gas and liquid phase) reactors and heterogeneous catalysts for multi-phase macromolecular reactions was carried out. A monolith-containing square die with Pd/Al2O3 catalysts was used to successfully hydrogenate poly(styrene) (PS). The inherent pulse behavior of the extruder was found to be sufficient to approach intrinsic kinetics at low polymer concentrations. At higher (10 wt% PS) concentrations, forced pulsing was shown to have a greater impact on observed reaction rates. Selectivity with this extruder-fed reactor was better than with a stirred tank in all cases, due to a more plug-flow-like residence time distribution. While accurate control …

Mercury Transport Through A Capped Sediment, Jianrong Liu

LSU Doctoral Dissertations

Laboratory simulation cells were employed to evaluate the effectiveness of a sand cap for containing highly mercury-contaminated lake sediments and the resultant impacts on the mercury fate beneath the cap. Sand cap can delay and reduce the migration of mercury into the overlying water; however, due to the small partition coefficient of mercury between sand and water, a capping material with higher partition coefficient is better for the long-term containment of mercury. In the following study, efforts were made to identify and investigate an active capping material which works effectively at containing and inhibiting the methylation of mercury. Based on …

Continuous Reservoir Model Updating By Ensemble Kalman Filter On Grid Computing Architectures, Xin Li

LSU Doctoral Dissertations

A reservoir engineering Grid computing toolkit, ResGrid and its extensions, were developed and applied to designed reservoir simulation studies and continuous reservoir model updating. The toolkit provides reservoir engineers with high performance computing capacity to complete their projects without requiring them to delve into Grid resource heterogeneity, security certification, or network protocols.

Continuous and real-time reservoir model updating is an important component of closed-loop model-based reservoir management. The method must rapidly and continuously update reservoir models by assimilating production data, so that the performance predictions and the associated uncertainty are up-to-date for optimization. The ensemble Kalman filter (EnKF), a Bayesian …

An Experimental Study On The Formation Of Polycyclic Aromatic Hydrocarbons During The Pyrolysis And Oxidation Of Catechol[Ortho-Dihydroxybenzene]-A Model Compound Representative Of Structural Units In Coal, Wood, And Biomass, Shiju Thomas

LSU Doctoral Dissertations

Polycyclic aromatic hydrocarbons (PAH) formed during the pyrolysis and combustion of solid fuels like coal, wood, and biomass are widespread environmental pollutants. Since some PAH are known to exhibit carcinogenic and mutagenic activity, understanding the chemical reactions responsible for PAH formation is of utmost importance. To better understand the reactions leading to the formation of PAH from complex solid fuels, pyrolysis and oxidation experiments have been performed in an isothermal laminar-flow reactor, using the model fuel catechol (ortho-dihydroxybenzene), a phenol-type compound representative of structural entities in coal, wood, and biomass. Catechol pyrolysis experiments have also been performed in the presence …

Plasma Medicine, Mounir Laroussi, Alexander Fridman

Electrical & Computer Engineering Faculty Publications

Recent demonstrations of plasma technology in the treatment of living cells, tissues, and organs are creating a newfield at the intersection of plasma science and technology with biology and medicine - Plasma Medicine.

Characterization Of A Polymer Surface With Sequentially Immobilized Proteins, Anuradha Subramanian, Tarlan Mammedov, Karl E. Kador

Anuradha Subramanian Publications

To overcome the procoagulant processes on the surfaces of biomaterials, surface modifications have been undertaken to achieve hemocompatability characteristics that are comparable to the native endothelium. Our immediate goal in this paper is to design and develop strategies to inhibit thrombin activation on biomaterial surfaces. We will use biodurable polyurethane (PU) as the background polymer and synthesize biomaterial surfaces containing two immobilized recombinant proteins. To attain our objective, we have first undertaken the surface modification of biodurable polyurethane (chronoflex- AR) to enable the sequential immobilization of proteins via a bi-dentate bridge, a novel modification strategy. We have verified the creation …

Novel Catalysts For The Production Of Co- And Co2-Free Hydrogen And Carbon Nanotubes By Non-Oxidative Dehydrogenation Of Hydrocarbons, Wenqin Shen

University of Kentucky Doctoral Dissertations

Non-oxidative dehydrogenation of hydrocarbons is an attractive alternative route for the production of CO- and CO₂-free hydrogen. It will satisfy a major requirement for successful utilization of polymer electrolyte membrane (PEM) fuel cells (< 10 ppm CO) and sequestering carbon as a potentially valuable by-product, carbon nanotubes (CNTs). Due to the deposition of carbon on the surface of catalyst particles during the reaction, catalyst performance, life-time, and purification of the generated carbon product, are significant issues to solve in order to make the process practically feasible. The scope of this thesis includes: the development of novel Fe, Ni, and Fe-Ni catalysts supported on a Mg(Al)O support to achieve improved catalytic performance with easily-purified CNTs; evaluation of catalysts for ethane/methane dehydrogenation at moderate reaction temperatures; and study of activation and deactivation mechanisms by a variety of characterization techniques including TEM, HRTEM, XRD, Mössbauer spectroscopy, and x-ray absorption fine structure (XAFS) spectroscopy. The Mg(Al)O support was prepared by calcination of synthetic MgAl-hydrotalcite with a Mg to Al ratio of 5. The catalysts were prepared either by conventional incipient wetness method or by a novel nanoparticle impregnation method, where the monodisperse catalyst nanoparticles were prepared in advance by thermal decomposition of a metal-organic complex in an organic-phase solution and then dispersed onto the Mg(Al)O support. Dehydrogenation of undiluted methane was conducted in a fix-bed plug-flow reactor. Before reaction, the catalysts were activated by reduction in hydrogen. Fe-based catalysts exhibit a higher hydrogen yield at temperature above 600ºC compared with monometallic Ni catalyst. FeNi-9 nm/Mg(Al)O, Fe-10 nm/Mg(Al)O and Fe-5 nm/ Mg(Al)O nanoparticle catalysts show much improved performance and longer life-times compared with the corresponding FeNi IW/Mg(Al)O and Fe IW/Mg(Al)O catalysts prepared by incipient wetness. 10 nm is the optimum particle size for methane dehydrogenation. Addition of Ni to Fe forming a bimetallic FeNi alloy catalyst enhances the catalytic performance at the temperatures below 650ºC. Metallic Fe, Ni, FeNi alloy and Fe-Ni-C alloy, unstable iron carbide are all catalytically active components. Catalysts deactivation is due to the carbon encapsulation. The carbon products are in the form of stack-cone CNTs (SCNTs) and multi-walled CNTs (MWNTs), depending on the reaction temperature and catalyst composition. The growth of CNTs follows a tip growth mechanism and the purity of cleaned CNTs is more than 99.5%.

Process For Formation Of Cationic Poly (Lactic-Co-Glycolic Acid) Nanoparticles Using Static Mixers, Yamuna Reddy Charabudla

University of Kentucky Master's Theses

Nanoparticles have received special attention over past few years as potential drug carriers for proteins/peptides and genes. Biodegradable polymeric poly (lactic-co-glycolic acid) (PLGA) nanoparticles are being employed as non-viral gene delivery systems for DNA. This work demonstrates a scalable technology for synthesis of nanoparticles capable of gene delivery. Cationic PLGA nanoparticles are produced by emulsiondiffusion- evaporation technique employing polyvinyl alcohol (PVA) as stabilizer and chitosan chloride for surface modification. A sonicator is used for the emulsion step and a static mixer is used for dilution in the diffusion step of the synthesis. A static mixer is considered ideal for the …

Synergistic Surfactant Interactions And The Consequences On Phase Behavior, Interfacial Tension Reduction And Hydrophobic Surface Wetting, Makonnen Mateós Payne

Dissertations, Theses, and Capstone Projects

The ability for some of the nonionic trisiloxane surfactants to completely and rapidly wet a hydrophobic surface has been well documented for several years. However, to date, the behavior of the trisiloxane surfactants at the solid-liquid interface is not yet completely understood, leading to an incomplete understanding of the mechanism for complete wetting. In this work we report our findings with regard to the synergistic interactions between polyethylene oxide surfactants of the general structure CiE j and compare the behavior to a known super wetting surfactant. Pendant drop tensiometry experiments and sessile drop contact angle measurements on hydrophobic surfaces were …

Characteristics Of Black Liquor Sprays From Gas-Assisted Atomizers In Hightemperature Environments, Andrew J. Mackrory, Dale Tree, Larry L. Baxter

Faculty Publications

Black liquor droplets in an entrained-flow gasifier that are too large or too small can cause problems in the chemical recovery process. It is therefore important in gasifier design to understand the nature of the atomized-gas spray. We used high-speed imaging to study black liquor sprays in cold and hot environments. Significant conclusions are that: 1. the droplet size distribution width is linked to the mean droplet size as for other sprays in the literature, necessitating a gasifier design that is tolerant of the distribution width associated with the target droplet size; 2. the shape of black liquor droplets is …

Catalytic Wet Air Oxidation Of Mono Azo Dye Orange Ii: Catalyst Selection, Reaction Kinetics, And Modeling, Pinar Ozdural

Civil & Environmental Engineering Theses & Dissertations

Wastewaters generated as byproducts of dyeing processes are not treatable with conventional methods. It has been estimated that among the 900,000 tons of different dyes produced annually in the world, approximately 10–15% are lost in wastewater streams during manufacturing and processing operations. Once in rivers and streams, dyes cause major problems, such as reducing light penetration, or displaying toxic effects on aquatic life. Therefore, it is essential that dyes are removed from wastewaters before being discharged into the environment.

This study focuses on the catalytic wet air oxidation (CWAO) of Orange II, a mono azo dye used in large amounts …

Evolution Of Surface Deposits On A High-Pressure Turbine Blade—Part I: Physical Characteristics, James Edward Wammack, Jared M. Crosby, Daniel Fletcher, Jeffrey P. Bons, Thomas H. Fletcher

Faculty Publications

Turbine blade coupons with three different surface treatments were exposed to deposition conditions in an accelerated deposition facility. The facility simulates the flow conditions at the inlet to a first stage high-pressure turbine (T=1150 C, M=0.31). The combustor exit flow is seeded with dust particulate that would typically be ingested by a large utility power plant. The three coupon surface treatments included: (1) bare polished metal; (2) polished thermal barrier coating with bondcoat; and (3) unpolished oxidation resistant bondcoat. Each coupon was subjected to four successive 2 h deposition tests. The particulate loading was scaled to simulate 0.02 parts per …

Effects Of Temperature And Particle Size On Deposition In Land Based Turbines, Jared M. Crosby, Scott Lewis, Jeffrey P. Bons, Weiguo Ai, Thomas H. Fletcher

Faculty Publications

Four series of tests were performed in an accelerated deposition test facility to study the independent effects of particle size, gas temperature, and metal temperature on ash deposits from two candidate power turbine synfuels (coal and petcoke). The facility matches the gas temperature and velocity of modern first stage high pressure turbine vanes while accelerating the deposition process. Particle size was found to have a significant effect on capture efficiency with larger particles causing significant thermal barrier coating (TBC) spallation during a 4 h accelerated test. In the second series of tests, particle deposition rate was found to decrease with …

Evolution Of Surface Deposits On A High-Pressure Turbine Blade—Part Ii: Convective Heat Transfer, Jeffrey P. Bons, James Edward Wammack, Jared M. Crosby, Daniel Fletcher, Thomas H. Fletcher

Faculty Publications

A thermal barrier coating (TBC)-coated turbine blade coupon was exposed to successive deposition in an accelerated deposition facility simulating flow conditions at the inlet to a first stage high pressure turbine (T=1150 C, M=0.31). The combustor exit flow was seeded with dust particulate that would typically be ingested by a large utility power plant. The turbine coupon was subjected to four successive 2 h deposition tests. The particulate loading was scaled to simulate 0.02 parts per million weight (ppmw) of particulate over 3 months of continuous gas turbine operation for each 2 h laboratory simulation (for a cumulative 1 year …

Multiscale Dynamic Monte Carlo / Continuum Modeling Of Drying And Curing In Sol-Gel Silica Films, Xin Li

University of Kentucky Doctoral Dissertations

Modeling the competition between drying and curing processes in polymerizing films is of great importance to many existing and developing materials synthesis processes. These processes involve multiple length and time scales ranging from molecular to macroscopic, and are challenging to fully model in situations where the polymerization is non-ideal, such as sol-gel silica thin film formation. A comprehensive model of sol-gel silica film formation should link macroscopic flow and drying (controlled by process parameters) to film microstructure (which dictates the properties of the films).

This dissertation describes a multiscale model in which dynamic Monte Carlo (DMC) polymerization simulations are coupled …

Surfactant And Metal Sorption Studies By Functionalized Membranes And Quartz Crystal Microbalance, Abhay R. Ladhe

University of Kentucky Doctoral Dissertations

Functionalized membranes provide an elegant platform for selective separations and sorptions. In this dissertation, application of functionalized membranes for surfactant and metal sorption studies are discussed. Sorption behavior of surfactants is also studied using quartz crystal microbalance (QCM) and other techniques.

Adsorption of the ethoxylated surfactants on polymeric materials (cotton and polyester) and model gold surface was quantified from a non-aqueous siloxane based solvent (D5) and water. The role of ethylene oxide group and the effect of nature of polymeric materials on adsorption behavior was quantified and established. In the case of gold-water interface, the adsorption data was fitted to …

Treatment Of Aqueous Waste Streams At Eli Lilly - Alternatives To Incineration, Barry Hennessy

Theses

The aim of this project was to investigate the potential to treat liquid waste (secondary) from production processes at Eli Lilly with the emphasis on minimising the volume of waste sent for thermal oxidation. In addition, the project aimed to investigate if the chosen technology was diverse and potentially capable of handling waste streams from different processes. Membrane technology was identified as one of the most suitable technologies and trials were carried out on secondary waste from three production processes. The literature review and practical thrials aswell as assessment of trial results ran from October 2003 to June 2005.

All …