Chemical Engineering Commons^™

Preparation And Application Of Catalysts For The Stereospecific Reduction And Photooxygenation Of Olefins In Continuous Operations: A Novel Method For The Production Of Artemisinin, Daniel C. Fisher

Theses and Dissertations

Over the last two centuries, the discovery and application of catalysts has had a substantial impact on how and what chemicals are produced.Given their broad significance, our group has focused on developing new catalyst systems that are recoverable and reusable, in an attempt to reduce concomitant costs.

Our efforts have centered on constructing a recyclable chiral heterogeneous catalyst capable of effecting asymmetric hydrogenations of olefins with high stereoselectivity. A class of phosphinoimidazoline ligands, developed by researchers at Boehringer-Ingelheim, known as BIPI ligands, have proven efficacious in the asymmetric reduction of alkenes. However, these chiral ligands are homogeneous and coordinated to …

Engineering Icephobic Coatings: Surface Characterization Of Pt Cured Silicones, Sithara Shylaja Nair

Theses and Dissertations

Ice buildup on structures leads to problems that include reduced performance, structural damage and power outages. It is therefore important to limit the energy required for removal of ice from substrates to minimize buildup. Understanding the mechanism of ice adhesion and its dependence on variables like coating thickness, stiffness, surface free energy and morphology is critical for minimizing adhesion. Despite several developments in “icephobic” coatings, which are those that have low ice adhesion, it is important to understand adhesion on the fundamental level to make way for advanced coatings. To do so, a study has been carried out that explores …

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 …

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 …

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.

Bulletproof Vests/Shields Prepared From Composite Material Based On Strong Polyamide Fibers And Epoxy Resin, Remon A. Mankarious, Mostafa A. Radwan, Mostafa Shazly, Hany A. Elazab

Chemical and Biochemical Engineering Faculty Research & Creative Works

Fiber Reinforced Plastics (FRP) have arisen as a main class of tactual materials having high strength and light weight implemented in a large scale of different applications. This study performs a comparison between the enhanced propidines of Kevlar 49 fiber and Twaron CT 704 reinforced with epoxy resin to obtain an efficient, light weight and slim body m o r capable of resisting high speed projectiles (9 mm bullets). Reinforcing the fabrics adds extra strength to the fabrics instead of using several unreinforced fabrics which increases the weight thickness and the cost of the final product. The response of the …

Mechanical Characteristics For Different Composite Materials Based On Commercial Epoxy Resins And Different Fillers, Marwa Mhamed Naeem, Mostafa A. Radwan, Mohamed A. Sadek, Hany Sa. Elazab

Chemical and Biochemical Engineering Faculty Research & Creative Works

In this research, different compositions of composite materials based on epoxy resin and four different fillers were prepared and all mechanical characteristics were investigated to reach a composite material having high resistance to impact by high kinetics energy projectiles which is required in the production of bulletproof jackets and also in cassette shields of explosive reactive armors to protect tanks. This composite material is usually applied as layers with other polymeric fibers such as carbon fibers and Kevlar (polyamide) sheets. The used epoxy consists of Epon as linear epoxy and tertiary amine as hardener. The used fillers are carbon black, …

Boosting The Electrochemical Performance Of Li₁.₂Mn₀.₅₄Ni₀.₁₃Co₀.₁₃O₂ By Atomic Layer-Deposited Ceo₂ Coating, Yan Gao, Rajankumar L. Patel, Kuan-Yu Shen, Xiaofeng Wang, Richard L. Axelbaum, Xinhua Liang

Chemical and Biochemical Engineering Faculty Research & Creative Works

It has been demonstrated that atomic layer deposition (ALD) provides an initially safeguarding, uniform ultrathin film of controllable thickness for lithium-ion battery electrodes. In this work, CeO₂ thin films were deposited to modify the surface of lithium-rich Li_1.2Mn_0.54Ni_0.13Co_0.13O₂ (LRNMC) particles via ALD. The film thicknesses were measured by transmission electron microscopy. For electrochemical performance, ∼2.5 nm CeO₂ film, deposited by 50 ALD cycles (50Ce), was found to have the optimal thickness. At a 1 C rate and 55°C in a voltage range of 2.0-4.8 V, an initial capacity of …

Ultrathin Conductive Ceo₂ Coating For Significant Improvement In Electrochemical Performance Of Limn₁.₅Ni₀.₅O₄ Cathode Materials, Rajankumar L. Patel, Sai Abhishek Palaparty, Xinhua Liang

Chemical and Biochemical Engineering Faculty Research & Creative Works

LiMn_1.5Ni_0.5O₄ (LMNO) has a huge potential for use as a cathode material in electric vehicular applications. However, it could face discharge capacity degradation with cycling at elevated temperatures due to attacks by hydrofluoric acid (HF) from the electrolyte, which could cause cationic dissolution. To overcome this barrier, we coated 3-5 micron sized LMNO particles with a ∼3 nm optimally thick and conductive CeO₂ film prepared by atomic layer deposition (ALD). This provided optimal thickness for mass transfer resistance, species protection, and mitigation of cationic dissolution at elevated temperatures. After 1,000 cycles of chargedischarge between …

Analysis Of The Production Data From Marcellus Shale Wells, Amanda Parrish

Graduate Theses, Dissertations, and Problem Reports (ETD)

The increasingly prevalent practice of unconventional technologies has called for the need for the critical analysis of production decline rates to meet economic targets. The high early time production returns and transient flow make matching a production curve to known methods of decline curve analysis problematic.

This research focuses on finding a technique that best fits a known production curve and then applying that technique to another well to check its accuracy. The goal is to find the earliest time of production data necessary to predict an accurate production curve over the lifespan of the well. This is essential to …

Modeling Effects Of Annealing On Coal Char Reactivity To O2 And Co2, Based On Preparation Conditions, Troy Michael Holland, Sham Bhat, Peter Marcy, James Gattiker, Joel D. Kress, Thomas H. Fletcher

Faculty Publications

Oxy-fired coal combustion is a promising potential carbon capture technology. Predictive computational fluid dynamics (CFD) simulations are valuable tools in evaluating and deploying oxyfuel and other carbon capture technologies, either as retrofit technologies or for new construction. However, accurate predictive combustor simulations require physically realistic submodels with low computational requirements. A recent sensitivity analysis of a detailed char conversion model (Char Conversion Kinetics (CCK)) found thermal annealing to be an extremely sensitive submodel. In the present work, further analysis of the previous annealing model revealed significant disagreement with numerous datasets from experiments performed after that annealing model was developed. The …

Dynamic Model And Estimator Development For A Smart Refractory Brick With Embedded Wireless Sensors For Gasifier Applications, Qiao Huang

Graduate Theses, Dissertations, and Problem Reports (ETD)

The operating temperature is one of the most important variables for gasifier operation. A higher temperature can shorten the service life of the refractory lining. A lower temperature can reduce the extent of carbon conversion and disrupt the flow of molten slag in a slagging gasifier. Therefore temperature is one of the most important variable in a gasifier. In slagging gasifiers, molten slag can penetrate into the refractory lining leading to refractory spallation, undesired downtime, and costly replacement. Even though the temperature and extent of slag penetration are extremely important for the gasifier operation, they cannot be measured reliably by …

Investigation Of Local Velocities And Phase Holdups, And Flow Regimes And Maldistribution Identification In A Trickle Bed Reactor, Mohd Fitri Bin Abdul Rahman

Doctoral Dissertations

"Trickle bed reactors are packed beds of catalyst on which gas and liquid reactants flow concurrently downward. In this work, the experimental work was carried out in 0.14 m diameter Plexiglas column using air-water system flowing over a packed bed of 3 mm glass bead particles. The local liquid and gas velocities, phase saturation and their time series have been investigated for the first time by developing, validating, and implementing a new two-tip optical fiber probe technique. It was found the radially and axially the liquid and gas velocities and their saturation vary and they also vary with times. In …

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 …

Estimation And Utilization Of Landfill Gas From Egyptian Municipal Wastes, A Case Study, Ali Habib, Ahmed A. Abdel-Rehim

Mechanical Engineering

Purpose

As the first Author had the chance to invest in landfill gas plant (EL Hammam plant) that flare approximately 1000 m3/hr. to generate electricity. Two critical question must be answered in order to proceed with the feasibility study. The three questions are:

1. 1- How many years this landfill gas emission will last?

2. 2- How much energy can be generated from one million ton if landfilled?

3. 3- How much CO2 in tons will be saved during the project life time?

Methods: Experimental method is used to determine BMP (Biochemical methane potential) ton CH4/ton waste. With

results we can know the …

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 …

Experimental Study Of Natural Convection Heat Transfer And Gaseous Dynamics From Dual-Channel Circulation Loop, Ibrahim Ahmed Said Abdallah

Doctoral Dissertations

"This research focuses on establishing a range of scaled separate and integral effects experiments for studying thermal-hydraulic behavior occurring within a component or region of the prismatic very high-temperature reactor (VHTR) such as plenum-to-plenum heat transfer and gaseous dynamics during natural circulation. Natural circulation of the coolant is the leading capability for VHTR to transport the decay heat from the core to the reactor vessel during accident scenarios. To address this need, a scaled-down facility is designed and developed with only two channels with upper and lower plena. The emphasis is placed on high-resolution and high-fidelity experimental data for local …

Atomic/Molecular Layer Deposition Prepared Size-Selective Catalysts And Supported Nickel Catalysts, Zeyu Shang

Doctoral Dissertations

"Heterogeneous catalysts are widely used because of their many advantages. In this dissertation, the application of atomic/molecular layer deposition (ALD/MLD) in heterogeneous catalyst synthesis and modification was examined.

A novel nanostructured size-selective catalyst was synthesized by depositing ultra-thin porous shells on the surface of catalysts. The ultra-thin porous shells were formed by oxidation of aluminum alkoxide films deposited by MLD. The catalytic activity of the size-selective catalyst was improved by introducing gaps between the porous shell and catalytic metal nanoparticles. The introduction of gaps greatly reduced the catalyst activity loss, which resulted from the contact areas between the active sites …

Experimental Investigations Of Natural Circulation In A Separate-And-Mixed Effects Test Facility Mimicking Prismatic Modular Reactor (Pmr) Core, Mahmoud M. Taha

Doctoral Dissertations

"After the Fukushima Daiichi nuclear power plant accident in 2011, significant attention was directed to investigate natural circulation thermal-hydraulics in Prismatic Modular Reactors (PMRs). Natural circulation is employed as a passive safety feature that passively removes the decay heat released after the loss of flow accidents (LOFA). Several computational studies have addressed such phenomena, however, validation of Computational Fluid Dynamics (CFD) is needed by providing high-quality data obtained from separate test facilities designed with reference to the corresponding reference PMRs. To address this need, a separate effects Plenum-to-Plenum Facility (P2PF) was designed and developed with dual channels and plena for …

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 …