Chemical Engineering Commons^™

Eliminating Magnetic Forces From The Surface Tension Measurement Of Magnetic Surfactants, Emily Koehler

Honors Theses

Surfactants have many applications due to their ability to reduce the surface tension between two phases. Magnetic surfactants, a relatively new form of surfactants, offer the possibility of further controlling a surfactant system by using an external magnetic field to induce alignment on the molecular level. One method of studying a magnetic field's effect on the magnetic surfactant system involves analyzing the change in surface tension at varied solution concentrations both in and outside a magnetic field. The pendent drop method uses the downward gravitational force on a droplet suspended from a needle to find the surface tension based on …

Combustion Of Novel Thermite Mixtures For Iodine Generation, Sergio Emanuel Guerrero

Open Access Theses & Dissertations

Halogen-containing reactive materials could be used for mitigating the spread of hazardous, active biological microorganisms aerosolized as a result of explosion. The present work exhibits experimental results on the combustion of mechanically alloyed aluminum-iodine (Al-I2) powder mixed with Fe2O3, CuO, MoO3, Bi2O3, and I2O5. Wet mixing was used to prepare the samples, which were then compacted into pellets and ignited with a CO2 laser. A chamber was designed and built to accommodate for combustion and collection of products, and the available laser ignition setup was modified to enable combustion experiments with rapidly burning gas-generating mixtures. High-speed video recording was used …

Commercialization Of Cobalt Promoted Molybdenum Disulfide Hydrodesulfurization Unsupported Catalyst, Juan Hilario Leal

Open Access Theses & Dissertations

Catalysis is a key player in the petroleum refining process. Our focus is primarily on the improvement of a commercial HDS (HydroDeSulfurization) hydrotreating catalyst. The commercial catalyst sold today is cobalt promoted molybdenum supported on γ-alumina. Our aim is to work with Porocel Industries LLC to produce an unsupported, cobalt promoted, molybdenum disulfide catalyst by improving on previous work conducted by Dr. Brenda Torres. The catalysts (B3&B5) developed by Dr. Torres were reported to be highly active on real feedstocks and were produced via hydrothermal process. Oxidic Mo, and H2S were used to make an ammonium tetrathiomolybdate precursor that was …

Solving Atomic Structures Using Statistical Mechanical Searches On X-Ray Scattering Derived Potential Energy Surfaces, Christopher James Wright

Theses and Dissertations

Engineering the next generation of materials, especially nanomaterials, requires a detailed understanding of the material’s underlying atomic structure. These structures give us better insight into structure-property relationships, allowing for property driven material design on the atomic level. Even more importantly, understanding structures in-situ will translate stimuli and responses on the macroscopic scale to changes on the nanoscale. Despite the importance of precise atomic structures for materials design, solving atomic structures is difficult both experimentally and computationally. Atomic pair distribution functions (PDFs) provide information on atomic structure, but the difficulty of extracting the PDF from x-ray total scattering measurements limits their …

Uncertainty Quantification In Computational Catalysis, Eric Alan Walker

Theses and Dissertations

This dissertation augments the field of computational catalysis with uncertainty quantification. An efficient tool to describe the energetics and structure of atomistic systems is density functional theory (DFT). DFT may be used to understand how catalysts work although DFT is inexact in nature due to approximations necessary for computational tractability. These approximations in DFT cause uncertainty in microkinetic model results for catalytic systems. Therefore, reliable model results gained from DFT include a quantification of uncertainty. The case study to examine a systematic framework for uncertainty quantification is water-gas shift (WGS CO+H2O⇌CO2+H2) reaction by Pt/TiO2 catalyst.

Uncertainties are represented with probabilities …

Methane Separation And Purification Via Pressure Swing Adsorption, Lutfi Erden

Theses and Dissertations

Investigations on alternative energy sources have gained increasing attention due to significant shortage in the fossil fuel reserves and increase on the usage of internal combustion engines. Natural gas which mainly consists of Methane has a significant role in short term solution of this issue. Although methane as a greenhouse gas is over 20 times more potent by weight than carbon dioxide, if released directly into the atmosphere, it is a valuable energy source. However, methane is not extracted % 100 pure from the source. Natural gas generally contains many other contaminants such as water, other hydrocarbons, Carbon dioxide, Nitrogen, …

Rational Design And Synthesis Of Pt/Silica-Alumina Metal-Acid Bifunctional Catalysts, Jadid Ettaz Samad

Theses and Dissertations

In the domain of rational catalyst design and synthesis, Strong Electrostatic Adsorption (SEA) has been applied with tremendous potential and use. In this study, SEA method has been advanced to thick slurries as well as to mixed oxide systems with a view to synthesizing stable, active and selective catalysts fine-tuned for specific applications.

The main objective was to synthesize metal-acid bifunctional catalysts with controlled ratio and proximity between metal and acid sites in order to analyze their effects on a bifunctional reaction. At first, the difference in charging behavior of silica and alumina in solution was used to selectively deposit …

การแตกสลายสีย้อมโดยใช้ไทเทเนียมไดออกไซด์ภายใต้การส่องสว่างด้วยแสงอาทิตย์, สุนิติ ไทยเจียมอารีย์

Chulalongkorn University Theses and Dissertations (Chula ETD)

งานวิจัยนี้มีวัตถุประสงค์เพื่อศึกษาอิทธิพลของตัวแปรต่างๆและหาภาวะที่เหมาะสมต่อประสิทธิภาพการแตกสลายสีย้อมรีแอคทีฟเรด 120 (RR120) ผ่านกระบวนการเร่งปฏิกิริยาเชิงแสงบนตัวเร่งปฏิกิริยาไทเทเนียมไดออกไซด์เชิงพาณิชย์ (Com TiO2) ตัวเร่งปฏิกิริยาไทเทเนียมไดออกไซด์สังเคราะห์ (Syn TiO2) และตัวเร่งปฏิกิริยาไทเทเนียมไดออกไซด์สังเคราะห์เจือไนโตรเจน (N-TiO2) ภายใต้การส่องสว่างด้วยแสงอาทิตย์ โดยตัวแปรที่ศึกษา ได้แก่ ระยะเวลาการฉายแสง ชนิดตัวเร่งปฏิกิริยาไทเทเนียมไดออกไซด์ แหล่งไนโตรเจน ปริมาณไนโตรเจน ปริมาณตัวเร่งปฏิกิริยา ความเข้มข้นเริ่มต้นของสีย้อมรีแอคทีฟเรด 120 และค่าความเป็นกรดด่าง จากผลการทดลองพบว่าภายใต้การฉายแสงอาทิตย์นั้นตัวเร่งปฏิกิริยาไทเทเนียมไดออกไซด์เชิงพาณิชย์ไม่สามารถแตกสลายสีย้อมได้ ในขณะที่ตัวเร่งปฏิกิริยาไทเทเนียมไดออกไซด์สังเคราะห์และตัวเร่งปฏิกิริยาไทเทเนียมไดออกไซด์สังเคราะห์เจือไนโตรเจนร้อยละ 10 โดยน้ำหนัก สามารถแตกสลายสีย้อมได้ แต่จะพบว่าตัวเร่งปฏิกิริยาไทเทเนียมไดออกไซด์สังเคราะห์เจือไนโตรเจนด้วยกัวนิดีน คาร์บอเนต ร้อยละ 10 โดยน้ำหนัก มีประสิทธิภาพในการแตกสลายสีย้อมได้ดีในทุกภายใต้การฉายแสง ที่ปริมาณตัวเร่งปฏิกิริยาเท่ากับ 5 กรัม สารละลายสี 1 ลิตรที่ความเข้มข้นเริ่มต้น เท่ากับ 100 มิลลิกรัมต่อลิตร และค่าความเป็นกรดด่างเท่ากับ 3 จากนั้นทำการศึกษาแบบจำลองจลนพลศาสตร์ของกระบวนการเร่งปฏิกิริยาเชิงแสงพบว่าสอดคล้องกับแบบจำลองแลงเมียร์-ฮินเชลวูด (Langmuir-Hinshelwood model) โดยแบบจำลองนี้สามารถอธิบายรูปแบบการเกิดปฏิกิริยาได้เป็นสองกระบวนการจากสองค่าคงที่ คือ ค่าคงที่การดูดติด (KLH) และค่าคงที่อัตราการเกิดปฏิกิริยา (kLH)

Design And Development Of A High-Temperature High-Pressure Rolling Ball Viscometer/Densimeter And Evaluation Of Star Polymer-Solvent Mixtures, Matthew Stanton Newkirk

Theses and Dissertations

Modern automotive applications such as transmission clutch plates, combustion chambers, diesel fuel injector tips, and axle gears and friction plates operate at temperatures that can exceed 250°C and pressures of 40,000 psia. Industrial practice is to add homopolymers and copolymers to base oils to modify bulk fluid viscosity and frictional properties for these demanding applications. However, designing polymeric additives for lubricants and predicting their performance is limited by the lack of available high-temperature high-pressure (HTHP) viscosity and density data needed to test contemporary lubricity models. Thus, a major objective of this thesis is the design, development, and commissioning of a …

Design And Commissioning Of A Community Scale Solar Powered Membrane-Based Water Purification System In Haiti, Shavin Pinto, Yung Wong, Kyle Fennesy, Yan Tang, Marc Compere

Publications

This paper presents the design and commissioning of a solar powered water purification system at the Ryan Epps Home for Children (REHC) in Michaud, Haiti. This system supplies clean drinking water to the 200 children who live and go to school at REHC and also to the community in the form of a micro-business. This micro-business is the mechanism for income generation for sustainable system operation. The purifier uses a three stage filtration system with a disc-type sediment filter, a 0.1 micron ultrafiltration membrane, and an ultraviolet light for disinfection. The backwash cycle extends the life of the ultrafiltration membrane …

Numerical Analysis Of Flexural Slip During Viscoelastic Buckle Folding, Davi Rodrigues Damasceno

Masters Theses

"Flexural slip is considered to be an important folding mechanism contributing in the development of different folds such as chevron, and kink-band buckle folds. Various filed studies have provided a general conceptual and qualitative understanding of flexural slip. However, quantitative evidence of the importance of the flexural slip mechanism during fold evolution is sparse, as the actual amount of surface parallel displacement, and timing, is difficult to measure accurately, due to the lack of suitable strain markers.

In this study 2D finite element analysis is used to overcome these disadvantages and to simulate flexural slip during viscoelastic buckle folding. Variations …

Modeling And Evaluation Of Moisture Diffusion In Polymer Composite Materials, Zhen Huo

Doctoral Dissertations

"Fiber-reinforced polymer composites have extensive applications due to their high specific strength, improved product performance, low maintenance and design flexibility. However, moisture absorbed by polymer composites during the service life plays a detrimental role in both the integrity and durability of composite structure. It is essential to understand the moisture diffusion behavior and induced damage in polymer matrix composites under varying hygrothermal conditions. In Part I, the moisture diffusion characteristics in hybrid composites using moisture concentration-dependent diffusion method have been investigated. Also, a multi-stage diffusion model was proposed to explain the deviation of moisture diffusion behavior for sandwich composites from …

Design, Fabrication, Operation And Aspen Simulation Of Oil Shale Pyrolysis And Biomass Gasification Process Using A Moving Bed Downdraft Reactor, Hassan Golpour

Doctoral Dissertations

"Energy is the major facilitator of the modern life. Every developed and developing economy requires access to advanced sources of energy to support its growth and prosperity. Declining worldwide crude oil reserves and increasing energy needs has focused attention on developing existing unconventional fossil fuels like oil shale and renewable resources such as biomass. Sustainable, renewable and reliable resources of domestically produced biomass comparing to wind and solar energy is a sensible motivation to establish a small-scale power plant using biomass as feed to supply electricity demand and heat for rural development. The work in Paper I focuses on the …

Wetting Kinetics In Forced Spreading, Amer Mohammad Al-Shareef

Doctoral Dissertations

"Under dynamic conditions, the dynamic contact angle (the angle that the liquid makes with the solid) of a liquid on a solid surface varies dramatically with substrate velocity from its equilibrium value. Experimental data of the dynamic contact angles for polydimethylsiloxane (PDMS or silicone oil) under air on a glass substrate coated with teflon, for water under PDMS, for solutions of the polymer polyethylene oxide (PEO) under air, for solutions of PEO under PDMS, were obtained to simulate and understand the systems of brine or brine containing a polymer displacing viscous crude. A variety of solid substrates were used other …

Nanostructured Materials Prepared By Atomic Layer Deposition For Catalysis And Lithium-Ion Battery Applications, Rajankumar Patel

Doctoral Dissertations

"Atomic/molecular layer deposition (ALD/MLD) has emerged as an important technique for depositing thin films in both scientific research and industrial applications. In this dissertation, ALD/MLD was used to create novel nanostructures for two different applications, catalysis and lithium-ion batteries.

MLD was used to prepare ultra-thin dense hybrid organic/inorganic polymer films. Oxidizing the hybrid films removed the organic components and produced the desired nanoporous films. Both porous alumina and titania films can be prepared by such a way. A novel nanostructured catalyst (Pt/SiO₂) with an ultra-thin porous alumina shell obtained from the thermal decomposition of an aluminium alkoxide film …

Modeling Of Rheological Properties For Entangled Polymer Systems, Nilanjana Banerjee

Doctoral Dissertations

"The study of entangled polymer rheology both in the field of medicine and polymer processing has their major importance. Mechanical properties of biomolecules are studied in order to better understand cellular behavior. Similarly, industrial processing of polymers needs thorough understanding of rheology so as to improve process techniques. Work in this dissertation has been organized into three major sections. Firstly, numerical/analytical models are reviewed for describing rheological properties and mechanical behaviors of cytoskeleton. The cytoskeleton models are classified into categories according to the length scales of the phenomena of interest. The main principles and characteristics of each model are summarized …

Scale-Up Investigation And Hydrodynamics Study Of Gas-Solid Fluidized Bed Reactor Using Advanced Non-Invasive Measurement Techniques, Abdelsalam Efhaima

Doctoral Dissertations

"This research focuses on validating our newly developed mechanistic scale-up methodology for hydrodynamics similarity of gas-solid fluidized bed reactors (FBRs) by implementing our advanced non-invasive measurement techniques which are gamma ray computed tomography (CT) and radioactive particle tracking (RPT) that measure local hydrodynamic parameters. Experiments were carried out in two fluidized beds of 14 cm and 44 cm in diameter using air as the gas phase and particles of different materials. Since in these reactors the gas dynamic dictates the bed hydrodynamics, the new mechanistic scale-up methodology is based on maintaining similar or closer time averaged radial profiles of gas …

Study Of Heat Transfer Phenomenon During Natural Convection, Muhammad Yousaf

Doctoral Dissertations

"The purpose of the present study was to numerically investigate the effects of the roughness elements on the heat transfer during natural convection. A computational algorithm was developed based on the Lattice Boltzmann method to conduct numerical study in two-dimensional rectangular cavities and Rayleigh-Bénard cell. A single relaxation time Bhatnagar-Gross-Krook model of Lattice Boltzmann method was used to solve the coupled momentum and energy equations in two-dimensional lattices. Computational model was validated against previous benchmark solutions, and a good agreement was found to exist. A Newtonian fluid of Prandtl (Pr) number 1.0 was considered for this numerical study. The range …

Modeling Gas Inflow For Extremely Low Permeability Shale Using Cfd, Chatetha Chumkratoke

Doctoral Dissertations

"Computational fluid dynamics (CFD) has been used to model 2-D well inflow over a range of permeabilities to study the impact of various well completion strategies (Augustine, 2011). Augustine's 2-D model was subsequently extended for 3-D flow by Thepporprapakorn (2013), for gas flow in the permeability range of tight gas (0.01 mD).

This work presents a 3-D CFD model of gas inflow valid for extremely low ranges of permeability (0.00001 mD). In extremely low permeability, gas flow is complex and includes flow from fractures, flow through porous media, and diffusive gas transport. Diffusive gas transport is important when strong density …

Modeling Explosive Lensing On A Cylindrical Body In Air: A First Step Towards Sealing An Underwater Offshore Oil Spill, Phillip R. Mulligan

Doctoral Dissertations

"In 2010, the British Petroleum (BP) Deepwater Horizon accident leaked oil into the Gulf of Mexico for 87 days. A fast response method that can seal an oil pipe and stop the release of oil is needed in order to prevent future oil leaks from turning into ecological and financial disasters. Explosives can serve this need.

This research examined how a circular implosive discontinuous explosive lens interacts with a cylindrical surface. The following research was designed to study the applicability of the Method this author developed to predict the peak pressure from multiple shockwaves converging on a centrally located cylinder. …