Chemical Engineering Commons^™

Statistical Mechanics Of Lipid-Liquid Crystal Systems: From Fundamentals To Sensing Applications, Donya Ohadi Kabir Maghsudlu

Theses and Dissertations

Understanding the thermodynamics of small systems has a well-established history. The non-intuitive behavior of the intensive properties of small systems comprised of less than a few hundred particles has important implications in many areas of engineering and materials science. Nevertheless, many open questions about the thermophysical properties of systems not in the thermodynamic limit remain unanswered. In the first part of this work, we explore the consequences of the coupling of two small subsystems that together make up a larger isolated system through the use of statistical mechanics and molecular dynamics simulations of Lennard-Jones particles in two dimensions. The results …

Pollutant Formation In Oxy-Coal Combustion, Nujhat Choudhury

Theses and Dissertations

With the increasing levels of carbon dioxide (CO2) in the atmosphere, researchers are driven to seek cleaner combustion techniques to burn coal for power generation. Oxy-coal combustion is a promising technique to cut down CO2 emissions. This technology requires the introduction of a pure oxygen (O2) stream and a recycled flue gas stream into the boiler instead of air. Flue gas stream generated from the system will be low in volume and highly concentrated in CO2. Thus, the capture and sequestration process will be facilitated. But, one of the concerns of adopting this technology is the altered chemistry of pollutants …

Co2 Capture From Flue Gas By A Psa Process Using A Novel Structured Adsorbent, Nima Mohammadi

Theses and Dissertations

First adsorption equilibrium isotherms for N2, O2, Ar and CO2 on zeolite 13X were measured at three temperatures (25, 50, 75 °C) and pressures up to 110 kPa with a volumetric method and validated by also measuring the same isotherms with a gravimetric system.

Then a comprehensive 2-D mathematical model was developed to study the fundamentals of adsorption processes in parallel channel structured adsorbents. The results clearly indicated that under studied circumstances the plug flow condition can be assumed and therefore the system is not subject to premature breakthrough.

The pressure drop of corrugated structured adsorbents with narrow triangular channels …

Supercritical Carbon Dioxide Treatment Of Natural Biomaterials For Tissue Engineering Applications, Dominic M. Casali

Theses and Dissertations

The number of people requiring an organ transplant in the United States has increased considerably over the past 25 years, but the number of organ donations has stagnated; over 8,000 people now die annually while awaiting a transplant or become too sick to receive one. Tissue engineering (TE), the design and production of artificial tissues and organs in vitro, has been proposed to alleviate this problem. Though synthetic polymers offer tunable mechanical and biochemical properties, natural biomaterials have recently garnered attention in TE for their high degree of biocompatibility and ability to direct cell proliferation and constructive tissue remodeling. Yet …

Rational Synthesis Of Catalysts For Biomass Conversion, Qiuli Liu

Theses and Dissertations

With climate change due to global warming, the production of hydrocarbon fuels and chemicals from renewable biomass resource has become more pressing in recent decades. The biggest challenge in biomass conversion is to develop active, selective and stable catalysts for particular applications. The objective of this research is to optimize catalytic performance for hydrodeoxygenation (HDO) and hydrogenation reactions by enhancing the stability of the support, tuning metal particle size, and controlling surface composition.

The high content of water in bio-oil and the aqueous environment of the upgrading process requires a hydrothermally stable catalyst. The hydrothermal stability has been effectively improved …

Structural, Interfacial, And Electrochemical Properties Of Pr2nio4+Δ – Based Electrodes For Solid Oxide Fuel Cells, Emir Dogdibegovic

Theses and Dissertations

Currently, the electrochemical performance and performance durability of solid oxide fuel cells (SOFCs) are limited by cathode materials. The high polarization resistance and phase instability of the cathode are two major challenges to hinder the commercialization of SOFC systems. Two families of oxides are presently known as potential cathode materials for SOFCs: (1) the perovskite family of oxides with a general formula of ABO₃, and (2) the Ruddlesden-Popper (RP) family of oxides (e.g. nickelates) with a general formula of A₂BO₄. The electron-hole conduction in these materials occurs simultaneously with oxygen ion conduction based on …

Platinum Nanoparticles-Cobalt Oxide Nanostructures As Efficient Binary Catalyst For Ethylene Glycol Electro-Oxidation, Ghada El-Nowihy

Chemical Engineering

An enhanced electrocatalytic activity towards ethylene glycol oxidation reaction (EGO) in alkaline medium is observed at a glassy carbon (GC) electrode modified with a nanoparticle-based binary catalyst composed of Pt (nano-Pt) and cobalt oxide (nano-CoOx). The electrocatalytic activity of the modified electrodes towards EGO depends on the loading level as well as the composition of the catalyst layer atop the GC electrode surface. Several techniques including cyclic voltammetry (CV), field-emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectroscopy (EDS) are used to address the catalytic activity of the proposed catalyst and to reveal their surface morphology and composition, respectively. …

Investigating A Sequentially Assembled Mnox/Pt Nanocatalyst As A Potential Anode For Ethylene Glycol Fuel Cells, Ghada El-Nowihy

Chemical Engineering

Aiming at a better electrocatalytic enhancement of ethylene glycol (EG) electrooxidation (EGO) in an alkaline medium for EG fuel cells (EGFCs), a MnOx/Pt anode was developed. A sequential layer-by-layer electrodeposition technique was employed to assemble first platinum nanoparticles (nano-Pt) directly onto the surface of a glassy carbon (GC) electrode then manganese oxide nanoparticles (nano-MnOx) were next immobilized. Field emission scanning electron microscopy (FE-SEM) and energy dispersive X-ray spectroscopy (EDS) were employed to evaluate the surface morphology and the bulk composition of the proposed catalyst in addition to the relative ratio of the catalyst’s ingredients. On the other hand, the catalyst …

A Quartz Crystal Microbalance Study Of Thiol:Ene Poly(Ionic Liquid) Polymerization And Gas Absorption, Yueming Wu

Murray State Theses and Dissertations

ABSTRACT

The polymerization process of, and gas absorption by, imidazolium-containing thiol:ene poly (ionic liquid)s (PILs), prepared from bisallylimidazolium bis(trifluoromethyl sulfonyl)imide [NTf₂^-] and pentaerythritoltetrakis(3 mercaptopropionate), was studied. The thiol:ene PILs examined were recently reported by groups at Murray State University. The advantage of thiol:ene PILs over other reported PILs is that thiol:ene polymers are made rapidly by UV exposure and exhibit high mechanical and thermal stability due to high cross-linking. The properties of interest for the thiol:ene PILs were studied using a quartz crystal microbalance (QCM). QCM techniques are based on the piezoelectric effect, where certain crystals (e.g., …

Evaluation Of Compositional Effects On Gas-Oil Miscibility And Gas-Assisted Gravity Drainage (Gagd) Eor Process, Mohamed Al Riyami

LSU Doctoral Dissertations

The Vanishing interface technique (VIT), offers fast and accurate determination of minimum miscibility pressure (MMP) between the reservoir crude oil and the various gases injected for enhancing oil recovery (EOR). The technique is based on miscibility being the condition where an interface between the injected fluid and the reservoir crude oil vanishes. This research has evaluated the effect of the gas-oil ratio on zero-IFT pressure. VIT experiments were simulated using an equation of state (EOS) and the Parachor model. This work proves the robustness of VIT in estimating miscibility pressures for gas injection EOR projects. Also this work presents a …

Performance Evaluation Of Virtual Flow Metering Models And Its Application To Metering Backup And Production Allocation, Kahila Mokhtari Jadid

LSU Doctoral Dissertations

In the oil and gas industry, reliable and accurate measurements of the amount of oil, gas and water being produced by individual wells is essential. The production revenue for each well is determined from measured flow rates. Measurement of well production can be achieved by using multiphase flow meters on individual wells. However, the use of such metering technique is not always reliable or economical. As an alternative technique to monitoring individual well performance in real-time, multiphase flow simulators together with pressure and temperature sensors located at different locations in the production systems have been recently deployed to estimate individual …

A Model-Centric Framework For Advanced Operation Of Crystallization Processes, Navid Ghadipasha

LSU Doctoral Dissertations

Crystallization is the main physical separation process in many chemical industries. It is an old unit operation which can separate solids of high purity from liquids, and is widely applied in the production of food, pharmaceuticals, and fine chemicals. While industries in crystallization operation quite rely on rule-of-thumb techniques to fulfill their requirement, the move towards a scientific- and technological- based approach is becoming more important as it provides a mechanism for driving crystallization processes optimally and in more depth without increasing costs. Optimal operation of industrial crystallizers is a prerequisite these days for achieving the stringent requirements of the …

The Role Of Surface Active Compounds In Crude Oil On Reservoir Wettability., Paulina Metili Mwangi

LSU Doctoral Dissertations

This study examines the role of crude oil’s surface active compounds (SAC) in determining the reservoir wettability. Wettability describes the relative preference of a reservoir rock for oil or water. Wettability influences the distribution of fluids in a reservoir and the efficiency of oil recovery methods. Unfortunately, the chemical mechanisms controlling wettability in individual reservoirs remain hazy. Wettability is conditional and is influenced by rock mineralogy, fluid chemistry, and temperature. An extensive experimental study was executed to understand the impact of naturally-occurring SACs typically found in crude oil, on the wettability of sandstone and carbonate rocks over a range of …

The Formation Of Polycyclic Aromatic Hydrocarbons From The Pyrolysis Of Model 1-Alkene Fuels, Eva Christine Caspary

LSU Doctoral Dissertations

To understand the role of 1-alkenes and allylic radicals in the reaction pathways leading to the formation and growth of polycyclic aromatic hydrocarbons (PAH), pyrolysis experiments have been performed with three 1-alkene fuels—propylene (CH₂=CH–CH₃), 1-butene (CH₂=CH–CH₂–CH₃), and 1-pentene (CH₂=CH–CH₂–CH₂–CH₃)—at temperatures of 600 – 1000 °C and a fixed residence time of 0.31 s. The experiments are carried out in an isothermal laminar-flow quartz-tube reactor. Analyses of the pyrolysis products by gas-chromatographic and high-pressure liquid-chromatographic techniques reveal that the three fuels differ in: 1) their conversion behavior, 2) the relative amounts of the major C₂ – C₄ species produced, and 3) …

Modeling Battery Performance Due To Volume Change In Porous Electrodes Due To Intercalation, Taylor R. Garrick

Theses and Dissertations

The demand for energy continues to increase as the economies of developing countries become more modern and show an increased need for a reliable energy infrastructure in order to meet the increased demand associated with a large and more mobile population. An increased demand puts a strain on all sectors, however it is specifically noticeable in the transportation sector where a significant portion of the fuel utilized for transportation comes from petroleum and other fossil fuels. Recently, using alternative forms of energy for transportation has become reality, and in turn, using electricity as a transportation fuel has gained significant momentum, …

Co-Gasification Of Coal And Biomass Wastes In An Entrained Flow Gasifier: Modelling, Simulation And Integration Opportunities, Dalia A. Ali Eng, Mamdouh A. Gadalla Prof., Omar Y. Abdelaziz, Christian P. Hulteberg, Fatma H. Ashour Prof.

Chemical Engineering

Gasification processes convert carbon-containing material into syngas through chemical reactions in the presence of gasifying agents such as air, oxygen, and steam. Syngas mixtures produced from such processes consist mainly of carbon monoxide (CO), hydrogen (H2), carbon dioxide (CO2), and methane (CH4); this gas can be directly utilised as a fuel to produce electricity or steam. Besides, it is regarded as a basic feedstock within the petrochemical and conventional refining industries, producing various useful products like methanol, hydrogen, ammonia, and acetic acid. In this work, a rigorous process model is developed to simulate the co-gasification of coal-biomass blends through an …

Enzymatically Active Microspheres For Self-Propelled Colloidal Engines, Jungeun Park

Dissertations and Theses

Micro- and nano-motors have attracted numerous attentions from various scientific areas due to their potential applications. Most studies on self-propelled colloidal engines have exploited catalytic decomposition of hydrogen peroxide to drive the motor. Since the hydrogen peroxide is caustic, it is not suitable to use in biological applications, encouraging people to develop “greener” fuels. The aim of this research is to study a new transduction mechanism for self-propulsion not tied to hydrogen peroxide, and which can in particular be used with biological molecules as fuels. In this study, we focus on making particles with enzymatic activity which can effectively decompose …

A New Thin Layered Structural Coating On A Metal Substrate For Enhanced Hydrogen Production From Steam Methane Reforming, Michael A. Lugo-Pimentel

Dissertations and Theses

In the past decade the use of hydrogen has become more ubiquitous. Its applications range from the upgrading of fossil fuels, to the production of ammonia, to the hydrogenation of fats, to the production of muriatic acid and methanol, all without including the efforts being taken to move towards a hydrogen economy. Its widespread use and its increasing demand lays pressure to find more efficient techniques of hydrogen production. Because the overwhelming majority of hydrogen produced nowadays comes from the steam reforming of natural gas (SMR), it appears that the most adept way to improve yields is by improving the …

Ionic Liquids Tethered To Activated Carbon For Capture Of Airborne Toxins, Devin Peck

Dissertations and Theses

Ionic liquids (ILs) were investigated for functionalization of activated carbon (AC) adsorbents for the filtration of warfare toxins. Preliminary steps were taken by testing absorption capacity of neat ILs and tethering ionic liquids to the surface of AC. AC is known to have good adsorption ability for warfare agents. Functionalizing the AC with ILs could enhance the capture ability significantly. ILs have been found to be good absorbents for a variety of gaseous species. The absorption selectivity and capacity can be tuned by changing the anion-cation pair. By tethering ILs to AC, the beneficial properties of gas absorption from ILs …

Property Analysis Of Silylamine Type Reversible Ionic Liquids For Use As A Thermal Safety Switch In Batteries, Showmik Podder

Dissertations and Theses

The increased capacity of the modern battery system has also brought about safety apprehensions. Uncontrollable runaway reactions are a big concern in these systems; these reactions are the result of in situ heat generation and very much increase the risk of explosions and device failures. The concept of this work is to provide a preliminary understanding into the use of a type of switchable solvent known as reversible ionic liquids (RevILs) and their feasibility in being used in electrolytes as a thermally-controlled reversible safety switch. In their pure forms these switchable solvents experience a dramatic change in their properties upon …