Chemical Engineering Commons^™

Froth Flotation Performance Enhancement By Feed Cavitation And Magnetic Plastic Particle Addition, Mehmet Saracoglu

Theses and Dissertations--Mining Engineering

Froth flotation is the most commonly used process to recover and upgrade the portion of the coal preparation plant feed that has a particle size smaller than 150 microns. Problems that occur when employing froth flotation in the coal industry include i) coal surfaces that are weakly-to-moderately hydrophobic, and ii) flotation systems that are overloaded and limited by insufficient retention time.

Research was performed to evaluate techniques that could be implemented to improve flotation performance under the aforementioned scenarios. Pre-aeration of flotation feed using a cavitation system was extensively evaluated in laboratory and full-scale test programs. The benefits of adding …

The Critical Role Of Mechanism-Based Models For Understanding And Predicting Liposomal Drug Loading, Binding And Release Kinetics, Sweta Modi

Theses and Dissertations--Pharmacy

Liposomal delivery systems hold considerable promise for improvement of cancer therapy provided that critical formulation design criteria can be met. The main objective of the current project was to enable quality by design in the formulation of liposomal delivery systems by developing comprehensive, mechanism-based mathematical models of drug loading, binding and release kinetics that take into account not only the therapeutic requirement but the physicochemical properties of the drug, the bilayer membrane, and the intraliposomal microenvironment.

Membrane binding of the drug affects both drug loading and release from liposomes. The influence of bilayer composition and phase structure on the partitioning …

Partial Oxidation Of Ethane To Acetic Acid On Titania Supported Movnbpd Catalyst, Yousef S. Al-Zeghayer, Abdulrhman S. Al-Awadi, Baba Y. Jibril, Moustafa A. Soliman, Sulaiman Al-Mayman

Chemical Engineering

Partial oxidation of ethane was studied on unsupported and supported Mo-V-Nb oxides. Different grades of titania (Crystal-AF4.60, AF7.70 and AF12.5 and Degussa P25) were explored as supports. Samples of the catalyst were characterized using XRD, SEM and BET surface area. The reaction was carried out at 200-275°C and 200 psi. At ethane conversion (6%), unsupported samples exhibited selectivities to ethylene and acetic acid of 76 and 23%, while for Degussa P25-supported sample, the values were 54 and 35%, respectively. Addition of Pd (0.196%) led to an increase in selectivity to acetic acid of 75%.

Doping Of Metal Organic Framework (Uio) And For N02 Adsorption At Ambient Conditions, Amani M. Ebrahim

Dissertations and Theses

Pollution issues and environmental concerns have led to the development of various air purification technologies. Nitrogen dioxide NO2 is one of the toxic gases in the atmosphere that is corrosive; it causes severe damage to materials, even at low concentrations. Research on the adsorption of this gas at atmospheric pressure and ambient temperatures is uncommon because of limited industrial applications. The thermal stability and microporous nature of Zirconium-based Metal Organic Framework (Zr-MOF) UiO-66 and UiO-67 make them good candidates for metal or amine decoration. The objective of this work was to investigate the effect of metal or amine doping (direct …

Emergence Of Delamination Fractures Around Casing And Its Stability, Wei Wang

LSU Doctoral Dissertations

The cement sheath failures and nearby wellbore failures may lead to upward flow of drilling fluid or formation fluid, which may have significantly adverse consequences like loss of reserve and environmental hazards. In order to maintain wellbore integrity in the long term, it is expedient to examine the causes of failures around the wellbore and propose suitable numerical models to predict annulus cracks around the casing. The complex failure behavior of cement/rock interfaces observed in the laboratory experiments does not look like the behavior of linear or simple nonlinear mechanical interfaces. Cohesive zone method (CZM) with BK-form bilinear traction separation …

Experimental And Modeling Study Of Foam Flow In Pipes With Two Foam-Flow Regimes, Ali Reza Edrisi

LSU Doctoral Dissertations

The use of foams can be found abundantly in many applications in a wide range of industries, including oil and gas industry. Although understanding foam flow behavior is crucial for the optimization of such applications, the complex flow behavior of foams has been a major challenge. Recent experimental studies with surfactant foams presented a new way to characterize foam flow characteristics by using two flow regimes: the low-quality regime showing either plug-flow or segregated-flow pattern, and the high-quality regime showing slug-flow pattern. This study consists of three main components: (1) experimental investigation of foam rheology in pipes; (2) building up …

Evaluation Of Gas-Assisted Gravity Drainage Eor Process Applicability In A Louisiana Oil Field Through Experiments And Reservoir Simulation, Wagirin Ruiz Paidin

LSU Doctoral Dissertations

The Gas-Assisted Gravity Drainage (GAGD) process was developed as an alternative to conventional gas injection enhanced oil recovery (EOR) processes, which suffer from their inherent weakness of combating gravity segregation. The GAGD process, however, is aimed at taking advantage of this phenomenon and consists of using horizontal producers near the bottom of the payzone while injecting gas using vertical injection wells. It is hypothesized that the injected gas will rise to the top, thereby forming a gas cap while displacing reservoir brine/oil downward towards the producers. In this study, a single-well alternative to the multi-well GAGD process was investigated to …

A Large Scale Network Model To Obtain Interwell Formation Characteristics, Seyedmohammadamin Gherabati

LSU Doctoral Dissertations

Limited data availability and poor data quality make it difficult to characterize many reservoirs. For reservoirs that have undergone waterflooding, production and injection data are a reliable source of information from which injector-to-producer connections can be inferred. In this research, we use well locations, injection and production rate data and well fractional flow values to develop a reservoir-scale network model. A Voronoi mesh divides the reservoir into a number of node volumes each of which contains a well. Bonds connect each of the nodes with conductance values that must be inferred from the rate data. An inverse problem is formulated …

Multi-Scale Modeling Of Inertial Flows Through Propped Fractures, Ali Takbiri Borujeni

LSU Doctoral Dissertations

Non-Darcy flows are expected to be ubiquitous in near wellbore regions, completions, and in hydraulic fractures of high productivity gas wells. Further, the prevailing dynamic effective stress in the near wellbore region is expected to be an influencing factor for the completion conductivity and non-Darcy flow behavior in it. In other words, the properties (fracture permeability and β-factor) can vary with the time and location in the reservoir (especially in regions close to the wellbore). Using constant values based on empirical correlations for reservoirs/completions properties can lead to erroneous cumulative productivity predictions. With the recent advances in the imaging technology, …

Titanium-Oxygen Bond Length -Bond Valence Relationship, D. Dodd, F. D. Hardcastle, S. Laffoon

Journal of the Arkansas Academy of Science

A bond length–bond valence correlation is a simple method of checking and evaluating molecular structures and is of great interest in chemistry, biology, geology, and material science. Recently, we used quantum-mechanical arguments to derive Pauling’s bond length-valence relationship and to define the adjustable fitting parameter b in terms of atomic-orbital exponents. Improved orbital exponents were generated for elements 1-103 using published atomic radii and single-bond covalent radii as well as a continuous function for effective principal quantum number. In this study, we use orbital exponents for titanium (Ti) and oxygen (O) to generate a bond length-valence relationship for Ti-O bonds. …

Tensile Failure During Structural Development Of Single-Layer Buckle Folds, Xiaolong Liu

Masters Theses

"Folds and fold trains of sedimentary strata are among the most common structural traps systems for hydrocarbon reservoirs. The existence of tensile fractures associated to buckle folding is associated to the distribution of extensional strain in the outer arc of the fold hinges. This study investigates the conditions under which tensile stresses develop due to buckling in a realistic in situ stress scenario. By applying a 2D finite element modeling approach, the influence of realistic mechanical stratigraphy (including strain rate, overburden depth, competence contrasts, viscosity, and permeability) on the development of single-layer buckle folds with Newtonian viscous rheology is studied. …

Two-Phase Flow In Microchannels: Morphology And Interface Phenomena, Alexandru Herescu

Dissertations, Master's Theses and Master's Reports - Open

The existence and morphology, as well as the dynamics of micro-scale gas-liquid interfaces is investigated numerically and experimentally. These studies can be used to assess liquid management issues in microsystems such as PEMFC gas flow channels, and are meant to open new research perspectives in two-phase flow, particularly in film deposition on non-wetting surfaces. For example the critical plug volume data can be used to deliver desired length plugs, or to determine the plug formation frequency. The dynamics of gas-liquid interfaces, of interest for applications involving small passages (e.g. heat exchangers, phase separators and filtration systems), was investigated using high-speed …

Engineering Novel Terpene Production Platforms In The Yeast Saccharomyces Cerevisiae, Xun Zhuang

Theses and Dissertations--Plant and Soil Sciences

The chemical diversity and biological activities of terpene and terpenoids have served in the development of new flavors, fragrances, medicines and pesticides. While terpenes are made predominantly by plants and microbes in small amounts and as components of complex mixtures, chemical synthesis of terpenes remains technically challenging, costly and inefficient. In this dissertation, methods to create new yeast lines possessing a dispensable mevalonate biosynthetic pathway wherein carbon flux can be diverted to build any chemical class of terpene product are described. The ability of this line to generate diterpenes was next investigated. Using a 5.5 L fed bath fermentation system, …

Solution Combustion Synthesis Of Cobalt Oxide For Use As A Catalyst Precursor In The Hydrolysis Of Sodium Borohydride, Teandra Leigh Pfeil

Open Access Theses

Solution combustion synthesized (SCS) cobalt oxide (Co₃O₄) powder has been studied as a catalyst precursor for the hydrolysis of sodium borohydride (NaBH₄). Synthesis is completed in less than two minutes and results indicate SCS is capable of reproducibly synthesizing 98.5-99.5% pure Co₃O₄ nano-foam materials. SCS materials demonstrate an as-synthesized specific surface area of 24 m²/g, a crystallite size of 15.5 nm, and fine surface structures on the order of 4 nm. Despite having similar initial surface areas and sample purities, SCS-Co₃O₄ outperforms commercially available Co_{3 …}

Self-Assembling Of Gold Nanoparticles Array For Electro-Sensing Applications, Islam M. Al-Akraa Dr, Ahmad M. Mohammad Prof, Mohamed S. El-Deab Prof, Bahgat E. El-Anadouli Prof

Chemical Engineering

A colloidal solution of citrate-stabilized gold nanoparticles (AuNPs) with an average size of ca. 2.6 nm has been prepared, characterized and further implemented in electro-sensing applications. This colloidal solution of AuNPs has been prepared via the reduction of NaAuCl4 with sodium tetrahydroborate (NaBH4) using trisodium citrate as a stabilizer. The optical properties of this solution have been studied with UV–Vis spectroscopy. Next, these AuNPs have been immobilized onto a polycrystalline Au (poly-Au) electrode with the assistance of benzenedimethanethiol (BDMT), which served as a binder. Attention has been taken to ensure the formation of a compact impermeable layer of BDMT on …

Efficient Numerical Scheme Of The Dynamics Of Nonisothermal Thin Film Flow, Moustafa A. Soliman, Khalid I. Alhumaizi

Chemical Engineering

In this work we use Lubrication type method, based on the possibility of the separation of longitudinal and transversal length scales to simplify the analysis of thin film dynamics. We study the dynamics of evaporating thin liquid films on an inclined plane, where the effect of van der Waal forces is significant. The numerical solution of the evolution equation is carried out using the method of orthogonal collocation and is used for the study of the instabilities of evaporating thin film to identify conditions for efficient operation. For symmetric cases where the plane is horizontal, a two spline collocation second …

Dynamics Of A Coating Film Flow On Horizontal Cylinders With Van Der Waals Forces, Moustafa A. Soliman, Khalid I. Alhumaizi

Chemical Engineering

In this work we use the lubrication type method, based on the possibility of the separation of longitudinal and transversal length scales, to simplify the analysis of coating film dynamics. We study the dynamics of coating thin films on horizontal stationary and rotating cylinders in general, and when the effect of van der Waals forces is significant. A computer code based on the method of orthogonal collocation is developed and is used for the study of the instabilities of coating thin film flow on cylinders to identify conditions of stable operation. For stationary cylinders, the equations are symmetric and the …

Applications Of High Throughput (Combinatorial) Methodologies To Electronic, Magnetic, Optical, And Energy-Related Materials, Martin L. Green, Ichiro Takeuchi, Jason R. Hattrick-Simpers

Faculty Publications

High throughput (combinatorial) materials science methodology is a relatively new research paradigm that offers the promise of rapid and efficient materials screening, optimization, and discovery. The paradigm started in the pharmaceutical industry but was rapidly adopted to accelerate materials research in a wide variety of areas. High throughput experiments are characterized by synthesis of a “library” sample that contains the materials variation of interest (typically composition), and rapid and localized measurement schemes that result in massive data sets. Because the data are collected at the same time on the same “library” sample, they can be highly uniform with respect to …

Capacity Fade Model For Spinel Limn2O4 Electrode, Yiling Dai, Long Cai, Ralph E. White

Faculty Publications

A mathematical model for the capacity fade of a LiMn₂O₄ (LMO) electrode is developed in this paper by including the acid attack on the active material and the solid electrolyte interphase (SEI) film formation on the LMO particle surface. The acid generated by the LiPF₆ and the solvent decompositions are coupled to the manganese (Mn) dissolution. The decrease of the Li ion diffusion coefficient is involved as another contribution to the capacity fade, which is caused by the passive film formation on the active material surface. The effects of cell practical operation/fabrication conditions and kinetics of …

Methane Hydrate Formation Under Different Surfactants, Mohammad Mahmud

Dissertations and Theses

No abstract provided.