Chemical Engineering Commons^™

Catalytic Hydrotreatment For The Development Of Renewable Transportation Fuels, Lilu Funkenbusch

Dissertations, Master's Theses and Master's Reports

Biologically-derived feedstocks are a highly desirable source of renewable transportation fuel. They can be grown renewably and can produce fuels similar in composition to conventional fossil fuels. They are also versatile and wide-ranging. Plant oils can produce renewable diesel and wood-based pyrolysis oils can be made into renewable gasoline. Catalytic hydrotreatment can be used to reduce the oxygen content of the oils and increase their viability as a “drop-in” transportation fuel, since they can then easily be blended with existing petroleum-based fuels. However, product distribution depends strongly on feedstock composition and processing parameters, especially temperature and type of catalyst. Current …

Marketing Strategies To Enhance Profitability Among International Oil And Gas Service Companies, Hesameddin Zafari

Walden Dissertations and Doctoral Studies

A significant drop in oil price in 2014 resulted in enormous pressure on marketing managers of international oilfield service companies to address new market expectations. In such competitive conditions, some marketing managers lack strategies to leverage profitability during downturns. The purpose of this multiple case study was to explore strategies that senior marketing managers of international oilfield service companies in the Middle East successfully used to enhance sales performance, revenues, and profits during periods of declining oil prices. Theory of market segmentation, targeting, and positioning formed the conceptual framework for this study. Data were collected through semistructured interviews of 5 …

Determination And Validation Of High-Pressure Equilibrium Adsorption Isotherms Via A Volumetric System, Hind Jihad Kadhim Shabbani

Theses and Dissertations

Adsorption equilibrium isotherms for N2, CO2, and CH4 on zeolite 13X were investigated at three different temperatures (25.5, 50.5 and 75.5 ̊ C) and a pressure range of (0-6.89475) MPa for CH4 and N2 and in the range of (0-4.82633) MPa for CO2 using built in volumetric apparatus. The results were validated using with a volumetric system (ASAP) at the same temperatures and a pressure up to (160-110) KPa respectively. The experimental results were correlated using three process Langmuir (TPLM). The correlated isotherms were then used to calculate the isosteric heat of adsorption for the three gases on 13X. The …

Stilbenes: Therapeutic Interventions Targeting Amyloid Β Protein Aggregation In Alzheimer’S Disease, Yiying Wang

Theses and Dissertations

Alzheimer’s disease (AD) is the most common form of dementia and accounts for 60-80 % of all dementia cases. In the United States, AD is ranked as the 6th leading cause of death and it is the only one among the top 10 that cannot be prevented, treated or even slowed. All FDA approved drugs focus on attenuating the symptoms for a limited time by regulating neurotransmitters without any intervention with the underlying disease process. A major player in the initiation and development of this debilitating disorder is the misfolding and subsequent aggregating of amyloid-β (Aβ) peptide. This aggregation process …

Ultrathin Graphene Oxide Membranes For Water Purification: Fundamentals & Potential Applications, Weiwei Xu

Theses and Dissertations

To develop ultrathin GO membranes with both high permeation rate and excellent selectivity, it is essential to understand the interlayer nanostructure and its influence on water purification performance. We purposely deposited GO at a fast rate and at a rate ~12 times slower to control the interlayer nanostructure of the resulting membranes. The d-spacing difference between proposed thermodynamically favored interlayer structure which formed at slow deposition rate and another relative randomly packed interlayer structure formed at fast deposition rate were corroborated by XRD, organic vapor deposition, and AFM. Molecular dynamics simulations further confirmed that, in type I structure, functionalized patches …

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 …

Sugar Versus Lipid For Sustainable Biofuels, Yaşar Demirel

Yaşar Demirel Publications

Introduction

First‐generation biofuels, namely, ethanol and biodiesel, have led to far reaching impact on the peoples’ life world‐wide.[1] However, they inter-fere with the food supply chain and may not be sustainable although some of the biomass are converted to biofuels after those biomasses have met the human needs. Still, the first‐generation–based biofuels have proved that sugar and lipid platforms can be an answer to energy security and global warming concerns without the need for new infrastructure for feedstock delivery as well as for biomass‐to‐biofuel conversion tech-nologies. At the same time, we are discovering and assessing the long‐term environmental im-plications on …

Use Of Natural Ores As Oxygen Carriers In Chemical Looping Combustion: A Review, Michael J. Matzen, Jessica Pinkerton, Xiaomeng Wang, Yaşar Demirel

Department of Chemical and Biomolecular Engineering: Faculty Publications

Chemical looping combustion (CLC) has gained considerable ground in energy production due to its inherent carbon capture with a minimal energy penalty. The choice of metal oxide used as an oxygen carrier (OC) in CLC has a substantial weight on the overall efficiency of energy production as well as the ultimate cost per MW. While much work has gone into manufacturing synthetic OCs with high fuel conversions, harsh operating conditions and process limitations cause some unavoidable loss of the oxygen carrier. With low production costs and minimal conditioning required, natural ores have grown in interest as cheap alternative oxygen carriers. …

Detecting Overpressure Zones By Using Model Based Inversion In Kupe Field, New Zealand, Timucin Cakir

Dissertations, Master's Theses and Master's Reports

Overpressure is a significant parameter during a drilling process in oil exploration. This phenomenon happens when pore pressure exceeds the limit of hydrostatic pressure in a formation and causes drastic hazards such as blow outs while drilling. This thesis focuses on the determination of possible overpressure areas and studies at three wells in Kupe Field, which is considered to be a natural-gas field in Taranaki Basin. In an effort to identify potential overpressure zones at the Kupe Field, acoustic impedance responses of 3D seismic data for three wells, along with their well log responses were evaluated.

Seismic inversion plays an …

Green Synthesis Of Copper Oxide Nanoparticles In Aqueous Medium As A Potential Efficient Catalyst For Catalysis Applications, Waad Mohsen, M. A. Sadek, Hany A. Elazab

Chemical and Biochemical Engineering Faculty Research & Creative Works

In this research, we have developed a reliable green method for the synthesis of copper oxide nanoparticles as a potential efficient catalyst for several catalysis applications. In our experimental approach, microwave-assisted synthesis technique was used in order to perform chemical reduction of copper salt using hydrazine hydrate as a strong reducing agent. The prepared catalyst was characterized using various techniques showing the formation of well dispersed copper oxide nanoparticles. The synthesized Copper oxide catalyst shows many advantages including the use of environmentally benign solvent systems, green synthetic approach, and mild reaction conditions.

Impact Of Vertical Internals On The Hydrodynamics And Heat Transfer Coefficient In A Gas-Solid Fluidized Bed, Haidar Moafaq Taofeeq

Doctoral Dissertations

"This research studied the impact of the dense vertical immersed heat exchanging tubes on the gas and solids hydrodynamic characteristics, flow regime, pressure drop, and heat transfer in a 0.14 m inside diameter gas-solid fluidized bed column of. Two sizes of vertical internal tube bundles (0.0127 and 0.0254 m) of circular arrangement have been implemented to represent the heat exchange tubes covering 25% of the column cross-sectional area. The experimental work was achieved at different operating conditions and various solids particle types that differ in average particle size, solids density, particles shape, and particles sphericity. The experimental measurements were performed …

Techno-Economic And Life Cycle Assessments Of Biofuel Production From Woody Biomass Through Torrefaction-Fast Pyrolysis And Catalytic Upgrading, Olumide Winjobi

Dissertations, Master's Theses and Master's Reports

Biofuel production through fast pyrolysis of biomass is a promising conversion route in the production of biofuels compatible with existing technology. The bio-oil produced from fast pyrolysis is a versatile feedstock that can be used as a heating oil or upgraded to a transportation hydrocarbon biofuel. Comparative study of a one-step, fast pyrolysis only pathway and a two-step torrefaction-fast pyrolysis pathway was carried out to evaluate the effect of torrefcation on (i) the minimum selling price of biofuel and (ii) the potential life cycle GHG emissions of the biofuel production pathway.

To produce bio-oil which can serve as a substitute …

Synthesis And Characterization Of Cross-Linked Polyimide Film Using Tolylene Diisocyanate, Sirichai Reeyakad

Chulalongkorn University Theses and Dissertations (Chula ETD)

Cross-linked polyimide films were synthesized by the reaction between diisocyanate groups and hydroxyl functional groups in polyimide structure, which was confirmed by IR. During the thermal treatment of the cross-linked polyimide, the thermal labile component (CO₂) in the urethane segments was decomposed which might generate pores in the film. The presence of the pores was confirmed from the dielectric constant of the film. The dielectric constant of the films decreased with the increase of TDI loading. By comparing the properties of the films, the PI50-C1.0 exhibited optimum mechanical and good dielectric properties. The cross-linked structure was also confirmed by DMA. …

Numerical Simulation Of Viscoelastic Buckle Folds: Implications For Stress, Fractures, Porosity And Fluid Flow, Xiaolong Liu

Doctoral Dissertations

"Over the past several decades, buckle folds have been exclusively studied by numerous methods. However, lots of assumptions and simplifications are made, which may not result in realistic in-situ stress conditions leading to rock failure. This study represents the first numerical simulation of folding under the consideration of gravity and pore pressure to simulate the structural development of buckle folds.

The first topic covered in this dissertation is the fracture associated to the single layer fold. It is concluded that burial depth, viscosity, and permeability are critical for the initiation of major fracture sets at the hinge zone with varying …

The Effect Of Testing Conditions On Lost Circulation Materials' Performance In Simulated Fractures, Montri Jeennakorn

Doctoral Dissertations

"Lost circulation (LOC) problems increase costs of drilling significantly. It is not only the cost of the drilling fluid that is lost into the formation but also the costs of subsequent problems that can be higher than the cost of the drilling fluids. LOC also possibly leads to a serious risk of blowout incident.

Lost circulation materials (LCM) are regularly added to the drilling fluids with an expectation of plugging the flow path. Due to the difficulties of testing and monitoring LCM sealing processes in the field, LCM evaluation in the laboratory is often used to prove and assure successful …

Semi-Empirical Model For Fire Spread In Shrubs With Spatially-Defined Fuel Elements And Flames, Dallan Prince, Chen Shen, Thomas H. Fletcher

Faculty Publications

A semi-empirical model was developed which forms shrub geometries from distinct fuel elements (e.g. leaves) and describes flame spread from element to element. Ignition, flame growth and flame decay patterns were based on combustion data of single leaves. Extension of the model to various heating conditions was achieved by scaling the flame growth parameters using physics-based heat transfer models. The resulting model offers a novel approach to examine fire spread and to explicitly describe both distinct fuel elements and fire behavior. This approach balances computational speed and modeling detail while providing a unique perspective into fire spread phenomena. Comparisons of …

Modeling Soot Oxidation And Gasification With Bayesian Statistics, Alexander Jon Josephson, Neal D. Gaffin, Sean T. Smith, Thomas H. Fletcher, David Lignell

Faculty Publications

This paper presents a statistical method for model calibration using data collected from literature. The method is used to calibrate parameters for global models of soot consumption in combustion systems. This consumption is broken into two different submodels: first for oxidation where soot particles are attacked by certain oxidizing agents; second for gasification where soot particles are attacked by H2O or CO2 molecules. Rate data were collected from 19 studies in the literature and evaluated using Bayesian statistics to calibrate the model parameters. Bayesian statistics are valued in their ability to quantify uncertainty in modeling. The calibrated consumption model with …

Model For The Evolution Of Pore Structure In A Lignite Particle During Pyrolysis. 2. Influence Of Cross-Linking Reactions, Molten Metaplast, And Molten Ash On Particle Surface Area, He Yang, Thomas H. Fletcher, Sufen Li, Haoquan Hu, Lijun Li

Faculty Publications

A model for the evolution of the pore structure in a lignite particle during pyrolysis was established previously based on the chemical percolation devolatilization (CPD) model, using coal polymer network parameters to calculate the surface area and porosity of the particle. In this paper, to get the accurate surface area of coal particle at high pyrolysis temperature, the previous model was improved by considering the effects of cross-linking reactions, molten Metaplast, and ash. The good agreement of the predicted surface area with experiments at temperature below 1200 K in the previous model is maintained, and model accuracy is improved at …

Effects Of Post Eviction Resettlement On Land-Use And Cover Change In Uganda’S Oil Exploration Areas, Joseph Ssekandi, John Mburu, Oliver Wasonga, Laban Macopiyo, Charles A. Francis

Department of Agronomy and Horticulture: Faculty Publications

Evaluation of the changes in land use and land cover change (LULCC) in respect to oil exploration across the Albertine region in Uganda has been focused around the exploration areas and protected areas, with no attention to the potential impacts of evictees’ activities on resettled areas. This study used LANDSAT images to analyze the land use and land cover changes (LULCC) among the period before eviction (2002 and 2005) at the climax of eviction and resettlements (2005-2011), and during the post-resettlement period (2011-2015) to quantify the impacts of resettlements on the environment. LANDSAT images were processed using ERDAS IMAGINE software …