Chemical Engineering Commons^™

Applications For The Quasi-Atomic Orbital And Constrained Density Functional Theory Methods On Catalytic Reactions, Alvaro David Loaiza Orduz

LSU Doctoral Dissertations

Selective activation of C–O, C–H, and C–C bonds underpins biomass upgrading, alkane functionalization, and CO₂ conversion. Despite their importance, the electronic factors governing catalytic performance remain incompletely understood, and many industrial processes still rely on empirical trends or material-specific observations. This dissertation addresses this gap by applying density functional theory (DFT), thermodynamic decomposition, and electronic-structure analysis to identify unifying principles of reactivity across transition-metal phosphides, vanadate oxides, copper-based electrocatalysts, and mixed IrO₂–RuO₂ layers. This work examines how charge transfer, orbital localization, and ligand-induced perturbations control reaction pathways in diverse catalytic systems. C–O bond scission in 2-methyltetrahydrofuran (MTHF) and methanol was …

Investigation Of Co-Current And Counter-Current Multiphase Flow In Upstream Drilling And Production Applications, Hazem Fleifel

LSU Doctoral Dissertations

In the domain of upstream Petroleum Engineering, the dynamics of co-current and counter-current multiphase flows present huge challenges, significantly impacting the efficiency of associated processes. This study investigates two specific applications concerning these flow behaviors, involving both laboratory experiments and transient computer simulations. This work investigates two distinct well control and production enhancement processes, involving multiphase flow dynamics: the bullheading kill procedure and liquid-assisted gas lift (LAGL).

The first topic (Topic 1) explores the bullheading process, a type of well control methods, by challenging the traditional understanding that gas removal efficiency increases monotonically with injection pump flow rate. Through 1D …

Anion Exchange Membrane Transport And Accelerated Testing Methods For Co2 Electrolyzers With Cu-Based Electrocatalyst, John C. Hendershot

LSU Doctoral Dissertations

Electrocatalytic carbon dioxide (CO₂) reduction to C₂₊ products holds promise for low carbon intensity fuels, chemicals, and food; however, durability challenges, particularly bicarbonate (HCO₃^-)and carbonate (CO₃^2-) salt precipitation, hinder their commercialization. This report considers water (H₂O) and ion transport properties of conventional anion exchange membranes (AEMs) in zero-gap membrane electrode assembly (MEA) configurations using Cu electrocatalysts. Transport characterization includes H₂O diffusion, permeability, potassium (K⁺) diffusion, and transference numbers using three commercial AEMs, including piperidinium-based (Versogen), quaternary ammonium-based (Fumasep), and imidazolium-based (Dioxide Materials) membranes. Accelerated lifetime …

Low Temperature Methane Coupling With Co And Co2, A K M Kazi F.M. Aurnob

LSU Doctoral Dissertations

Methane is the smallest hydrocarbon and the most abundant component in natural gas. Despite its availability, its chemical utilization has remained limited due to the challenges associated with direct methane activation and conversion. Most of the methane oxidation and oxidative carbonylation reactions in literature have been carried out at high-pressure using batch reactors or at ambient pressure using flow reactors. While batch reactors have been shown to have higher product yields, they are limited in their capability to provide real-time kinetic insights and comprehensive mechanistic understanding of the reactions involved due to the long residence time. This limits rationalization of …

Magnetic Field Enabled Assembly And Propulsion Of Colloidal Particles In A Magnetic Medium, Hashir M. Gauri

LSU Doctoral Dissertations

Colloidal particles are nano/micro meter-sized particles dispersed in a fluid medium and serve as diverse building blocks for assembling complex structures. The ease of tunability of the shape, size, and interparticle interactions of colloidal particles facilitates their assembly into rich structures and phases that mirror the assembly process of atomic systems. Often regarded as "big atoms" colloidal particles provide an ideal model system for investigating complex phenomena in condensed matter, such as crystallization and nucleation. While the assembly of colloids under thermodynamic equilibrium has been extensively studied, recent interest has shifted toward exploring colloids in non-equilibrium conditions to create dynamic …

Interfacial Phenomena Of Plastics: From Surface Modifications To Environmental Impacts, Kennedy Guillot

LSU Doctoral Dissertations

Plastic is a ubiquitous part of everyday life since its introduction in the previous century. Global production continues to exponentially increase, establishing plastics as one of the most dominant materials in modern manufacturing. Within the scope of academia, plastic is essential due to its low cost and sterility, particularly for minimizing contamination. Beyond the laboratory, plastic use spans numerous industries, and its use and disposal has since raised many environmental concerns. Once valued for its durability, plastics now pollute the environment in landfills and natural ecosystems. In recent decades, the consequences of this pollution have been investigated, yet the full …

Rheological, Interfacial, And Filtration Behavior Of Lignocellulosic Nanomaterials In Suspension And Emulsion Drilling Fluids, Meen Sung Koo

LSU Doctoral Dissertations

In recent years, the rheological aspects of suspensions/emulsions applied by cellulose nanomaterials (CNMs) have been gained considerable interests due to high gel-forming properties ascribed by hydrophilicity, crystallinity, ease functionalization, and high aspect ratio. Introducing residual lignin in CNMs (LCNMs) seemed to be capable of achieving various advantages in the application of CNMs ascribed by hydrophobicity, binding effects, and abundant aromatic groups derived from complexity of lignin. This dissertation dedicates to the characterizations of (L)CNMs, and rheological properties of (L)CNMs applied fluids (i.e., suspension and emulsion). In the suspension system, the presence of lignin in LCNMs decreased gel strength, viscosity, and …

Improving The Stability And Selectivity Of Methane Dry Reforming Catalysis Through Active Site And Process Tuning, Jonathan Lucas

LSU Doctoral Dissertations

Dry reforming of methane (DRM) is a potential industrial solution to greenhouse emissions whereby CH₄ and CO₂ are reacted on a transition metal catalyst to produce syngas, a feed stock for higher value chemical products. Ni can be used as the catalyst for DRM replacing the high cost and low abundance noble metals (Pt, Pd, Rh). However, the harsh process conditions of DRM (T > 700°C, P of 1-10 bar) readily deactivate Ni through coking and sintering. Ni supported on reducible oxides, specifically CeO₂ and CeO₂-ZrO₂ (CZO), have been widely studied to combat the rapid …

Non-Catalytic Direct Partial Oxidation Of Methane To Methanol In A Wall-Coated Microreactor, Kelly Cohen

LSU Doctoral Dissertations

This project used an integrated mixer-reactor-heat exchanger microtube scalable module for the non-catalytic direct partial oxidation of methane in natural gas to methanol at elevated pressures (70-95 bar), reaction temperatures of 380-460C, reactant methane:air ratios of 0.5-4.4 and reaction zone residence times on the order of 1 min. Currently, methane in remote locations is often flared in large quantities rather than transported or converted to the more easily transportable methanol. However, if this gaseous methane were converted to liquid methanol at the wellhead, it could be transported in ways other than pipeline or used onsite.

Additionally, methane is currently converted …

Precision Bottlebrush Polymers: Synthesis, Characterization, And Structure-Property Relationship, Nduka D. Ogbonna

LSU Doctoral Dissertations

Bottlebrush polymers, a type of non-linear polymer characterized by densely grafted side chains on a linear backbone, offer a versatile platform for material design due to their unique thermomechanical and rheological behavior. Addressing the grand challenge of achieving structural precision for bottlebrush polymers remains crucial because traditional disperse mixtures are plagued with batch variability, limiting our ability to control their functions, and correlate theoretical predictions with experiments. To date, narrow-dispersity bottlebrush polymers remain highly heterogeneous, as they are typically synthesized from disperse linear building blocks.

To address this longstanding challenge of structural heterogeneity in brush polymers, the primary objective of …

A Coarse-Grained Molecular Dynamics Study Of Gas Hydrate Formation And Dissociation, Meisam Adibifard

LSU Doctoral Dissertations

The study of gas hydrates has increased significantly over the last two decades because of their potential application in energy storage, production and transportation, water desalination, refrigeration, gas separation, etc. There is a significant interest in commercially developing natural gas hydrates because the energy content of methane hydrate reservoirs (MHRs) is at least twice that of all conventional fossil fuels combined. Additionally, due to the higher storage capacity of hydrates, it is proposed to sequester CO₂ in the form of CO₂ hydrate, thereby reducing the amount of greenhouse gases. Hence, hydrates offer a dual solution to two of …

Engineering Electronic Properties Of Random Alloys For Catalytic Applications, Andrew N. Okafor

LSU Doctoral Dissertations

Engineering catalytic materials is a key endeavor in the catalysis science to improve the catalytic activity of existing catalysts for specific applications and reduce the dependence on rare metals and minerals. While alloying, or mixing of metals, has been extensively studied, the focus has conventionally been placed on intermetallic phases or nanostructures such as core-shell particles, which are conceptually described by simple lattice models. This research focuses on understanding the catalytic properties of structurally ordered but compositionally disordered (or random) alloys, which have remained under-explored due to complexity at the atomic scale. Existing research focuses on synthesizing multicomponent alloys and …

Catalytic Upcycling Of Waste Plastics By Induction Heating, Bernard Whajah

LSU Doctoral Dissertations

The development of plastics over the past half century has led to rapid technological advances; however, the long-term negative environmental impacts of these materials compel new depolymerization and upcycling strategies. Plastics are indispensable due to their unique physical and chemical properties and affordability, leading to a significant increase in production rates. However, their recycling rates lag far behind their production rates. Polyolefins like LDPE and HDPE, which are common plastics, decompose very slowly in the environment. Converting these plastics into useful products often requires high-temperature pyrolysis, resulting in undesired distributions of products.

To address this challenge, this study focuses on …

Improved Modeling And Application Of Data Assimilation In Gas Influx Management During Managed Pressure Drilling, Chen Wei

LSU Doctoral Dissertations

The management of gas influxes in a drilling well has been considered one of the most critical topics for maintaining petroleum drilling safety and efficiency. Reliable modeling of gas influx behaviors in a wellbore or a marine riser greatly benefits the improved understanding of a gas kick event and the development of optimized influx management strategies. However, the current studies on transient multiphase flow modeling show varying limitations on both the model rigorousness and the overall numerical efficiency. Meanwhile, the existence of great system uncertainties, such as the unclear influx sizes and distributions in the well/riser, has brought significant challenges …

Research On 3d Printing Resin Exposure Properties And Its Application On Centrifugal Microfluidic Platform Based On Fluorescence Detection, Zheng Qiao

LSU Doctoral Dissertations

This dissertation encapsulates significant advancements in the field of SLA 3D printing and centrifugal microfluidics. Central to the research is the development of a novel mathematical model for predicting trapped resin thickness in SLA 3D printing, a groundbreaking contribution that addresses a critical aspect of printing intricate structures. This model, the first to establish a mathematical relationship for resin thickness, is rooted in a comprehensive study of the resin curing process. The research leverages the concept of 'critical dosage' for resin curing, leading to a more refined and theoretically grounded approach for calculating curing thickness. Experimentation further validates the model, …

Thermal Frontal Polymerization – Applications In Coatings And Composites, Maria Martinez

LSU Doctoral Dissertations

Thermal frontal polymerization has long been used as a method to cure composites and coatings. However, this is the first time these applications have been used without the use of a catalyst, for the case of composites and coatings.

Chapter 2 discusses how to optimize cure-on-demand, thin layer coatings, using frontal polymerization. Previously, for the use of curing thin layer coating using thermal FP, it was known to just make the formulation viscous enough, as this would prevent premature quenching caused by heat loss. It was discovered that for a given layer thickness, a minimum viscosity and initiator concentration were …

Induction Heating Driven Heterogeneous Catalysis: Magnetically Induced Nanoparticle Catalysts, Cameron Lee Roman

LSU Doctoral Dissertations

Heterogeneous catalysis has been and continues to be highly studied due to being one of the cornerstones of the chemical industry. With an increasing demand for chemicals and rising costs, there is a growing need to adapt to changing feed stocks and increase production efficiency. Polymers, oxygenates, and other chemical intermediates are predicted to experience continued growth, corresponding to an increased need for olefines. Due to the abundance of shale gas, researchers and producers are interested in meeting this demand via the dehydrogenation of light alkanes.

While dehydrogenation catalysts are a valuable tool in olefin production, selectivity and deactivation remain …

The Fabrication Of Nearly Monodisperse Chiral And Achiral Plasmonic Nanostructures And Their Applications, Macayla J. Caso

LSU Doctoral Dissertations

An object is chiral when it holds no lines of symmetry. This quality naturally occurs in chemistry and biology. When an object is chiral it has a unique handedness and objects of opposite chirality are called enantiomers. The importance of handedness was brought to light in the 1960’s when a racemic mixture of thalidomide enantiomers was given to pregnant women. One enantiomer was able to treat morning sickness while the other caused severe birth defects. This case brought to light how enantiomers have unique properties from each other even though they are similar materials. With this knowledge chiral nanomaterials must …

Physiologically Relevant Fluid Shear Stress Induced Receptor Conversion In Hormone Receptor-Positive (Hr+) Breast Cancer, Jonathan James Cuccia

LSU Doctoral Dissertations

Breast cancer is the most common type of cancer among all people in the United States as of 2023 and often has devastating impacts on afflicted patients. Although some treatments show great efficacy against primary breast tumors, none have been able to significantly reduce the mortality rate of breast cancer once it has metastasized to distant sites. In primary, hormone receptor-positive (HR+) breast cancers, endocrine therapies are often used as first-line treatments and are generally well-tolerated. However, as the disease progresses, these previously sensitive cancers can become resistant to endocrine therapies and continue proliferating despite them. Therefore, there is a …

Computational Design Of Electro-Organocatalysts And Transition Metal Sulfides For The Electrochemical Reduction Of Co2, Foroogh Khezeli

LSU Doctoral Dissertations

Abstract

Electrochemical CO₂ reduction (ECO₂RR) has emerged as a promising approach for generating carbon-neutral liquid fuels by utilizing excess renewable electricity to convert CO₂. This thesis aims to employ atomistic simulations by using Density Functional Theory (DFT) to investigate the mechanistic details of how transition metal sulfides and electro-organocatalysts can enhance the activity and selectivity towards desired products, including those containing C-H bonds and molecules with C-C bonds. For this project, three different electrocatalysts were designed computationally.

Firstly, MoS₂ was chosen as a transition metal sulfide catalyst with the objective of understanding the kinetics …

Design And Synthesis Of Plasmonic Nanoparticles For Nir Bioimaging: Investigating The Role Of Absorption And Scattering, Luis Dias Bumba Manuel

LSU Doctoral Dissertations

Nanoparticles have made vast advances in the realm of nanomedicine and bioimaging, enabling technologies such as photothermal therapy of malignant tumors and noninvasive monitoring of living tissue. Many of these innovations have only arisen in the last few decades with potential for growth in many avenues. The research shown in this work addresses some of the existing literature's void. Particularly solving synthesis challenges that have existed for more than 20 years in synthesizing Au nanoshells and establishing the potential for molecular-level deep imaging of plants. A novel investigation of the role of light absorption and scattering in bioimaging led to …

Hybrid Modeling For Electrochemical Systems, Luis Alejandro Briceno-Mena

LSU Doctoral Dissertations

The discovery of new materials like catalysts, polymeric films, and biomolecules, is driven by industrial needs such as improving reaction or separation selectivity, enhancing therapeutic effects on medical treatments, or reducing costs of replacement. However, deployment of these advances in industrial applications is often hindered by the lack of models needed for design and optimization. Due to the novelty of materials and devices, experimental data and first principles' knowledge are scarce, making it hard to build models either via data-driven or knowledge based approaches. In this context, a way to efficiently combine domain knowledge with data could provide a pathway …

Non-Equilibrium Colloidal Phenomena In Magnetic Fields And Photoillumination: From Controlling Living Microbots To Understanding Microplastics, Ahmed Al Harraq

LSU Doctoral Dissertations

Colloids are a ubiquitous class of materials composed of microscopic particles suspended in a continuous phase which are found in everyday products and in nature. Colloids are also useful models for studying the spontaneous arrangement of matter from individual building blocks to mesophases. Standard treatment of colloid science is based on the assumption of equilibrium conditions, as defined in traditional thermodynamics. However, novel assembly mechanisms and motility are unlocked by pushing colloids away from equilibrium using external energy. In addition, many colloids in nature and in industrial applications exchange energy and mass with the surrounding environment thus behaving in a …

Computational Study Of C-C Coupling Reactions On Heterogeneous Catalysts, Md Saeedur Rahman

LSU Doctoral Dissertations

The utilization of carbon dioxide (CO₂) in chemical production has attracted global research interest. Reacting CO₂ with methane (CH₄) removes these greenhouse gases from the atmosphere and turns both compounds into building blocks for organic compound synthesis. A commonly explored pathway involves dry reforming of methane (DRM), which reacts CH₄ and CO₂ to form syngas, a mixture of H₂ and CO. Syngas is a widely used feedstock for synthesizing chemicals ranging from methanol to fuels via the Fischer-Tropsch (FT) process. However, DRM has a large positive ΔGº, which requires the …

Application Of Distributed Fiber-Optic Sensing For Pressure Predictions And Multiphase Flow Characterization, Gerald Kelechi Ekechukwu

LSU Doctoral Dissertations

In the oil and gas industry, distributed fiber optics sensing (DFOS) has the potential to revolutionize well and reservoir surveillance applications. Using fiber optic sensors is becoming increasingly common because of its chemically passive and non-magnetic interference properties, the possibility of flexible installations that could be behind the casing, on the tubing, or run on wireline, as well as the potential for densely distributed measurements along the entire length of the fiber. The main objectives of my research are to develop and demonstrate novel signal processing and machine learning computational techniques and workflows on DFOS data for a variety of …

Ultraviolet Chiral Plasmonics, Tiago Ramos Leite Da Silva

LSU Doctoral Dissertations

The far- (λ < 250 nm) ultraviolet (UV) chiroptical response from protein secondary structures can aid in understanding protein interactions for drug discovery. Chiral metasurfaces have attracted attention to enhance the intrinsically weak biomolecular optical activity for improved structural biology characterization. However, due to materials and fabrication challenges, current metasurfaces mostly operate in the visible and near-infrared regimes with limited, if any, response in far-UV. The large spectral mismatch between metasurface and biomolecular resonances limits the chiral enhancement factor. In this work, we study aluminum planar metamaterials which display optical activity in the UV region. In the first part of this work, we experimentally and computationally investigate the resonant plasmonic-biomolecular interactions in the far-UV. To the best of our knowledge, our work is the first to experimentally explore these resonant interactions in the biologically relevant far-UV regime. We demonstrate experimentally and computationally enhanced chiral sensing of sub-10 nm amino acid films. We develop a full-wave computational model of a biomolecular film on an aluminum gammadion array using experimentally derived chiral parameters (κ) for L- and DTyrosine films. Our model shows that detectable enhancements in the circular dichroism (CD) and birefringence (CB) signals from small amounts of biomolecules are only possible when tight spectral overlap exists between the plasmonic and biomolecular chiroptical signals. We support this conclusion experimentally by fabricating aluminum gammadion arrays on fused silica substrates and sublimating ultrathin racemic, L- and D- Tyrosine films on the arrays. Complete Mueller matrix analysis of the resonant plasmonic-biomolecular system agrees with our computational results and demonstrates the importance of using far-UV active metasurfaces for enhancing natural optical activity. In the second part of this work, we study hybrid aluminum reflective metasurfaces, which leverage both local and propagating surface plasmons (PSP). These materials display strong bi-anisotropy with rich polarization conversion properties. We explore several geometries and verify how their symmetry properties affect their far-field response. Our observations provide an opportunity for researchers to improve the chiral response of plasmonic metasurfaces, especially in the challenging ultraviolet regime.

Bioremediation Of Petroleum-Based Contaminants By Alkane-Degrading Bacterium Alcanivorax Borkumensis, Amber Julaine Pete

LSU Doctoral Dissertations

The world’s dependence on petroleum hydrocarbons has led to significant environmental implications. For example, oil spills cause lasting environmental damage, and the increase of plastics in the marine environment has been growing, specifically, microplastics that can be difficult to detect due to their small size. Petroleum hydrocarbons occur naturally in nearly all marine environments, which has allowed hundreds of microorganisms to evolve to utilize these hydrocarbons as their primary energy source. These microbes are classified as hydrocarbonoclastic and are utilized to remove spilled oil biodegradation. Over the last ten years, progress has been made in the biodegradation of oil spills …

Engineering The Lanthanide And Actinide Dopants Effects On The Local Environment Of Luminescent Complex Metal Oxide, Yuming Wang

LSU Doctoral Dissertations

Rare earth (RE) based phosphor materials are widely used as luminescent probes in high-temperature optical thermometry where standard methods are unsuitable. The current generation of luminescent thermometers lacks stability and energy transport within the operating temperature ranges. The challenge is developing an oxide-based material with high luminescence intensity and thermal sensitivity/stability, suitable for an optical temperature sensor/thermal barrier coating. This work aims to develop a fundamental understanding of the local environment surrounding RE or actinide dopants in metal oxide hosts to engineer their luminescence property. To maximize the luminescence, the local symmetry, doping concentration, and radiative/non-radiative relaxation pathways must be …

Characterization Of Gas Hydrate Formation And Its Impact On Slope Stability In Offshore Environments, Sulav Dhakal

LSU Doctoral Dissertations

Natural gas hydrates (NGH) are predominantly methane hydrates formed at high pressure and low temperature conditions typically in submarine sediments and permafrost. This dissertation is focused on the submarine methane hydrates formed by upward migration of free and dissolved gas. The methane gas stored within natural hydrates has more energy potential than all the combined oil and gas resources around the world. Numerical simulation of fluid flow, heat transport, and geomechanical stresses is used to characterize and evaluate the saturation, distribution, reservoir quality, and geohazards associated with hydrate-bearing sediments. Coupled thermo-hydro-mechanical (THM) simulation of hydrate formation, dissociation, and slope stability …

A Drift-Flux Model For Upward Two-Phase In Pipes With High Velocity Flows, Woochan Lee

LSU Doctoral Dissertations

This study proposes the evaluation and development of a drift-flux model for upward two-phase high-velocity flow in large diameter pipes. A case where the proposed model is applicable is WCD (Worst-Case-Discharge) calculations for offshore wells. WCD assumes relatively larger pipe diameters and higher flow rates than the flow experiments at laboratory conditions utilized to validate and develop most of the flow models available in the literature.

Most of the two-phase flow models describe flow regime transitions as discrete processes by assigning the required void fraction or velocity for each flow regime transition. Therefore, for each flow regime, flow-regime-dependent correlations or …