Chemical Engineering Commons^™

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 …

Human And Organisational Factors As A Risk Management Strategy In An Aviation Maintenance Company, Samuel Cromie, Paul Liston, Derek Ross, Siobhan Corrigan, Lindita Vani, Dara Lynch, Solonas Demosthenous, Maria Chiara Leva, Alison Kay, Vangelis Demosthenous

Articles

Aviation has for many years been one of the leading industries in addressing human and organisational factors (HOF) within its different sectors – flight operations, air traffic control, ground operations, maintenance, etc. In particular aviation has led the way in mandating a range of measures that address HOF issues – reporting systems, shift-handover procedures, etc (e.g. UK CAA, 2003). A key element of the regulation has been the mandating of initial and continuation training in HOF for virtually all personnel working in aviation maintenance. By contrast the development of practice and regulation of risk and safety management in aviation has …

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. …

Catalytic Conversion Of Biomass Derived Syngas To Liquid Fuels Using Fischer-Tropsch Synthesis, Pratibha Sharma

LSU Master's Theses

Biomass gasification and subsequent conversion to liquid hydrocarbons using Fischer-Tropsch synthesis is a promising source of energy in today’s scenario when the focus has shifted from conventional fuels to alternate sources of energy. Biomass derived syngas is different from other sources of syngas such as steam reforming of methane followed by water gas shift, in terms of H2/CO ratio. Biomass syngas is usually hydrogen deficient and contains various impurities which need to be removed prior to Fischer-Tropsch Synthesis. Syngas derived from biomass also differs significantly with the different sources of biomass, gasification process and the cleanup conditions it is subjected …

Activity Of Halide-Free Flux At Copper And Tin Surfaces, Guoying Qu

LSU Master's Theses

The activity of halogen-free carboxylic acid flux is considered one of the most important aspects in controlling flip chip joint quality recently. In this work, we examined the CuOx removal effectiveness of carboxylic acid solutions at Cu substrates using electrochemical methods at elevated temperatures from 100ºC to 180ºC. Reaction kinetics of CuOx removal were investigated by chronopotentiometry and gravimetric analysis. FTIR was used to study the surface chemistry, and spectrophotometry was used to understand reactant and product solubility. Kinetics of carboxylic acid solution such as adipic acid or maleic acid in polyethylene glycol (PEG) with and without complexing agents such …

Effect Of Surfactant On Dynamics Of A Droplet Released In A Quiescent Medium, Abhijit Rao

LSU Master's Theses

During the ‘Deepwater Horizon’ accident, dispersants were used as one of the remediation methods to mitigate the ill effects of oil that entered the water column. The dispersants lower the interfacial tension at the oil-water interface and cause the large oil droplets to disintegrate into finer droplets which remain dispersed in the water column for longer times. A dispersant typically is composed of a surfactant and solvent. Surfactants are chemical compounds which are chiefly responsible for the lowering of interfacial tension at oil water interface. In this study, we have investigated the effect of surfactant on the dynamics of a …

A Feasibility Study Of Multi-Functional Wells For Water Coning Control And Disposal, Lu Jin

LSU Doctoral Dissertations

Although water coning is well understood, it is difficult to control in field operations resulting in low recovery and large volumes of waste produced water. A solution - proposed here - is a multi-functional well with the in-situ bottom water drainage and injection installations - Downhole Water Loop (DWL). Theoretically, DWL greatly improves well performance (for example, a two-fold increase of DWL well’s water drainage rate would increase the critical (water-free) oil rate by 80%). However, DWL has practical limitations that must be quantified for actual well design. The objective of this work is to: (1) find maximum water drainage …

Dynamic Modeling Of Channel Formation During Fluid Injection Into Unconsolidated Sands, Sayamik Ameen

LSU Master's Theses

Water injection is widely used for sweeping hydrocarbons in waterflooding operations, and also for maintaining reservoir pressure or disposing waste water. Injection at a high rate is required to maintain the economy of waterflooding projects; however, loss of injectivity is a quite common problem in unconsolidated sand formations like deep water Gulf of Mexico. Well intervention operations, hurricanes, and other issues require frequent shut-downs during the life of offshore wells; in order to minimize deteriorating effect of these shutdowns on wellbore injectivity more accurate modeling of the injection process is needed. Injection of water into a saturated, granular, porous medium …

The Diagnosis Of Well Control Complications During Managed Pressure Drilling, Brian Piccolo

LSU Master's Theses

The constant bottom-hole pressure method of managed pressure drilling is generally expected to reduce well control risks and apply well understood concepts when a kick is taken. Nevertheless, complications, such as operator error, leaks, plugging, equipment failures, and exceeding kick tolerance, can occur during kick circulation. By not properly interpreting the symptoms of a complication, a driller risks the consequences of additional influx, lost circulation or the simultaneous occurrence of both. To address the challenge of diagnosing complications, the implied pit gain (IPG) method is being evaluated as an enhancement to established industry practices. Traditional diagnostic methods attempt to match …

Modeling, Simulation And Analysis Of Renewable Energy Production Systems: Application To Multi-Product Biorefineries, Aryan Geraili Nejadfomeshi

LSU Master's Theses

The primary purpose of this research is to investigate the design and modelling of fully integrated processes which utilize renewable feedstock as raw materials and evaluate the alternative technology and possible process integration options for biorefinery processes to select the optimal configuration based on the production yields and economical profit criteria. The case study considered in this work is a lignocellulosic biorefinery plant which has different technology choices for each section of the process and the ability to produce multi-products from lignocellulosic raw materials. We analyzed different scenarios by simulating the superstructures in Aspen Plus. To incorporate more non-linarites in …

Aggregation Of Uncontrolled Fluids During Catastrophic System Failures In Offshore Environments, James Thomas Stiernberg

LSU Master's Theses

Safety culture relating to offshore operations has shifted since the Deepwater Horizon blowout and resulting oil spill. This incident has prompted the research of high volume spills during all stages of hydrocarbon exploration and production. This study particularly covers the interactions of wells and offshore networks as they pertain to situations where a release of reservoir fluids to the environment is occurring. Primary concerns of this investigation are stream confluences, leak modeling, and fluid behavior; the first two will be handled with various numerical software packages (OLGA®, CFD, and nodal analyses) while the later will require more rigorous treatment and …

Reaction Of Green Leaf Volatiles As A Source Of Secondary Organic Aerosols In Fog Droplets, Amie Kathryn Hansel

LSU Master's Theses

Green leaf volatiles (GLVs) are a group of biogenic volatile organic compounds (BVOCs) released into the atmosphere by vegetation when plants undergo stress or mechanical damage. BVOCs produce secondary organic aerosol (SOA) in the gas phase; however, their oxidation as a source of SOA in the liquid phase has not been investigated. Once released into the atmosphere, water-soluble GLVs partition into atmospheric water phases such as fog, mist, dew or rain, where they are oxidized by hydroxyl radicals (ÿOH). Photochemical oxidation yields products that are higher in molecular weight, more polar, more oxygenated, and lower in vapor pressure. When the …

Novel Separation Strategy For Processing Biopyrolysis Liquids, Chuanlin Zhao

LSU Master's Theses

The separation of pyrolysis bio-oil is important for its role in upgrading oil quality and acquiring commercial byproducts. A selective separation method for biopyrolysis liquids is developed in this work. Two parts in succession are involved as the first one aims at selectively removing some of the heaviest fractions from bio-oil. Chromatographic adsorption results show that Class C Fly ash and pyrolysis Bio-char have potential for this goal at <300 ºC, byproduct like combined adsorbates / adsorbents could also be used directly in asphalt cement processes. Thereafter, the second part focuses on adsorbing light fractions like lighter acids and aldehydes selectively. Basic (modified) activated carbons display relatively low selectivity at ~250ºC, but they have better selectivity compared to unmodified activated carbons. Thus some carbon-coated mesoporous silica and alumina materials are also prepared for the adsorption of these light compounds in the future. The combination of the two parts of adsorptions would leave behind a middle distillate fraction which is the bio-oil fraction most amenable to catalytic upgrading, to either a fuel or chemical feedstock.

Modeling And Design Of Photocatalytic Reactors For Air Purification, Yangyang Zhang

USF Tampa Graduate Theses and Dissertations

Photocatalysis is a promising technique for the remediation of indoor air pollution. Photocatalysis utilizes semiconductor photocatalysts (such as TiO₂ or ZnO) and appropriate light to produce strong oxidizing agents (OH*) that are able to break down organic compounds and inactivate bacteria and viruses. The overall goal of the research is to develop an efficient photocatalytic reactor based on mass transfer for indoor air purification. This study has focused on the enhancement of the effectiveness of the photocatalytic process by the introduction of artificial roughness on the reactor catalyst surface. The major effect of artificial roughness elements on the catalytic …

Model Pt- And Pd-Based Electrocatalysts For Low Temperature Fuel Cells Applications, Selasi Ofoe Blavo

USF Tampa Graduate Theses and Dissertations

In the search for alternative energy technologies, low temperature fuel cells continue to feature as technologies with the most promise for mass commercialization. Among the low temperature fuel cells, alkaline and proton exchange membrane fuel cells are the most popular. Alkaline fuel cells have typically been used for water generation as well as auxiliary power for space shuttles. Their bulkiness however makes them undesirable for other applications, especially in automobiles, where there is a great demand for alternative technologies to internal combustion engines. Proton exchange membrane fuel cells on the other hand possess numerous qualities including their compact size, high …

Development Of Catalytic Technology For Producing Sustainable Energy, Syed Ali Z Gardezi

USF Tampa Graduate Theses and Dissertations

This dissertation explores catalyst technology for the production of renewable liquid fuels via thermo-chemical conversion of biomass derived syngas. Fischer-Tropsch synthesis is a process for converting syngas, i.e. a mixture of CO and H2, into energy rich long chain hydrocarbons and oxygenated compounds. This synthesis process involves a number of elementary reactions leading to an array of polymeric products. The economic operation of an FTS process lie in the interplay of both catalyst and reactor design. In relation to catalysis, the nature of chemisorbed species, and the fractional availability of active metal sites determines rate, conversion and yield. Similarly, reactor …

Kelvin Probe Electrode For Contactless Potential Measurement On Concrete-Properties And Applications, Michael Thomas Walsh

USF Tampa Graduate Theses and Dissertations

The practical feasibility of using a Kelvin Probe as a novel reference electrode in the measurement of both potential and polarization pulse response of reinforcing steel in concrete is demonstrated. Potential values measured using a KP reflect greater stability and repeatability than can typically be attained with conventional reference electrodes. Duplicate reinforced concrete beam test specimens with well-differentiated centrally corroding rebar segments were analyzed using both the Kelvin Probe (KP) and a conventional Saturated Calomel Electrode (SCE). Potential profile maps were developed using potential values recorded under static conditions with both the SCE and the KP. Nominal polarization resistance was …

Application And Characterization Of Self-Assembled Monolayers In Hybrid Electronic Systems, Michael Enoch Celesin

USF Tampa Graduate Theses and Dissertations

In this study, we explore ultra-thin insulators of organic and inorganic composition and their potential role as high-speed rectifiers. Typical applications for these structures include IR sensing, chemical detection, high speed logic circuits, and MEMS enhancements. While there are many elements in the functional group required to create a rectifying antenna (rectenna), the primary thrust of this work is on the rectifier element itself.

To achieve these research goals, a very good understanding of quantum tunneling was required to model the underlying phenomenon of charge conduction. The development of a multi-variable optimization routine for tunneling prediction was required. MATLAB was …

Synthesis Of Titanium Dioxide Photocatalyst With The Aid Of Supercritical Fluids, Haitao Li

USF Tampa Graduate Theses and Dissertations

Titanium Dioxide (TiO2) emerged as one of the most popular photocatalysts since 1970's. However, its photocatalytic activity requires UV irradiation due to its large band gap unless further functionalization or modifications are performed. Furthermore, recovery issue has always been a major drawback, if the more effective form nano particles are utilized.

The key objectives of this research were synthesizing new TiO2 based photocatalyst systems that are effective with both the UV and the visible light while utilizing novel superior environmentally friendly techniques enabling development of nano-structured photocatalysts that can be easily recovered. In this dissertation research, highly porous nano-structured TiO2/WO3/Fe3+ …

One Dimensional Stochastic Coating Growth Kinetics Of Peg 3400 Onto Ammonium Nitrate In A Fluidized Bed, Brandon Smeltzer

USF Tampa Graduate Theses and Dissertations

Fluidized beds represent a cost effective, scalable technology invaluable to the chemical processing community as part of the global scheme of particle design. However, despite wide spread use and multiple approaches (empirical and mechanistic) to modeling a fluidized bed coating process, operations must be done at different scales due to changes within the balance of phenomenological forces (e.g. gravity, buoyancy, drag, surface tension, viscosity, kinetic energy).

Ammonium nitrate is synthetic compound that has multiple applications such as fertilizer, rocket fuel, and self-cooling applications. Ammonium nitrate has five temperature dependent crystal structures that are accompanied by a change in density. The …

Sedimentation Of Swarms Of Particles At Low And Moderate Reynolds Numbers, Oladapo Olanrewaju Ayeni

LSU Master's Theses

The sedimentation of a cloud of particles in a viscous fluid at low and moderate Reynolds numbers has been studied using an Eulerian-Lagrangian multiphase flow approach. We looked at the volume fraction dependence of the settling cloud and find a similar dependence in the simulations as in the theoretical predictions of (Nitsche and Batchelor 1997). The average cloud settling velocity and the velocity fluctuations around this average are found to have a functional dependence on ö^1/3 at negligible Reynolds number. The velocity fluctuations display strong anisotropy with the magnitude of the vertical component almost three times the magnitude of the …

Discrete Phase Simulations Of Drilled Cuttings Transport Process In Highly Deviated Wells, Doguhan Yilmaz

LSU Master's Theses

Transporting drilled cuttings from the bottomhole to the surface becomes more difficult and problematic in highly deviated wells than in vertical wells. Cuttings tend to settle down on the low side of the annulus typically in the form of a bed which can cause further problems. The height of this bed depends on many parameters such as annular domain geometry, drilling fluid density and rheology, annular flow rate, drill pipe rotation speed, cuttings size, shape, and their density. Prediction of the stationary cuttings bed height with respect to these aforementioned parameters is thus necessary to optimize the range of the …

Thermal, Compositional, And Salinity Effects On Wettability And Oil Recovery In A Dolomite Reservoir, Azadeh Kafili Kasmaei

LSU Master's Theses

Low salinity and composition effects in improving oil recovery in sandstone reservoirs are known. However, these effects have not been thoroughly studied for the carbonate reservoirs. Because of the lack of the clay minerals in the carbonate rocks, the mechanisms for the improved oil recovery with low salinity, brine composition, and temperature may not be the same as those for sandstones. This experimental study attempts to investigate the effects of low salinity, brine composition, and temperature on wettability and oil recovery in a dolomite reservoir. Also, it is attempted to confirm that wettability alteration is the main mechanism for improvement …

Structured Materials For Catalytic And Sensing Applications, Selma Hokenek

USF Tampa Graduate Theses and Dissertations

The optical and chemical properties of the materials used in catalytic and sensing applications directly determine the characteristics of the resultant catalyst or sensor. It is well known that a catalyst needs to have high activity, selectivity, and stability to be viable in an industrial setting. The hydrogenation activity of palladium catalysts is known to be excellent, but the industrial applications are limited by the cost of obtaining catalyst in amounts large enough to make their use economical. As a result, alloying palladium with a cheaper, more widely available metal while maintaining the high catalytic activity seen in monometallic catalysts …

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 …

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 …}

Tannic Acid Coated Gold Nanorods Demonstrate A Distinctive Form Of Endosomal Uptake And Unique Distribution Within Cells, Emily A. Untener, Kristen K. Comfort, Elizabeth I. Maurer, Christin M. Grabinski, Donald A. Comfort, Saber M. Hussain

Chemical and Materials Engineering Faculty Publications

One of the primary challenges associated with nanoparticle-dependent biological applications is that endosomal entrapment in a physiological environment severely limits the desired targeting and functionality of the nanoconstructs. This study sought to overcome that challenge through a systematic approach of gold nanorod (GNR) functionalization: evaluating the influence of both aspect ratio and surface chemistry on targeted cellular internalization rates and preservation of particle integrity. Owing to their unique spectral properties and enhanced surface area, GNRs possess great potential for the advancement of nanobased delivery and imaging applications. However, their ability for efficient intracellular delivery while maintaining their specific physiochemical parameters …

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 …

Theoretical Investigation Of The Water-Gas Shift Reaction At The Three Phase Boundary Of Ceria Supported Platinum Metal Clusters, Sara Aranifard

Theses and Dissertations

The Water-Gas Shift (WGS: CO+H2O→CO2+H2) reaction is a key step in hydrogen fuel processing for mobile fuel cell applications. Since the reaction is equilibrium-limited and exothermic, high conversions are favored by low temperatures. However, conventional low-temperature shift catalysts are not active enough. Reducible oxide supported small noble metal clusters have shown excellent activity as low temperature WGS catalysts and it is generally believed that these catalysts are bifunctional. In other words, the reaction occurs at the three-phase boundary (TPB) of the noble metal, the reducible oxide, and the gas phase. The small noble metal cluster adsorbs/activates the CO molecules and …