Chemical Engineering Commons^™

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 …

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 …

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 …

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 …

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. …

Development And Evaluation Of A Coaxial Cable Sensing System For Co₂ Sequestration Wellbore Integrity Monitoring, Yurong Li

Doctoral Dissertations

"Downhole monitoring plays a crucial part in geological carbon dioxide (₂) sequestration. Various downhole monitoring technologies have been explored and applied, but they are either expensive or have system longevity issues. To address this issue, a robust and cost-effective downhole sensing system based on distributed coaxial cable sensors is developed and evaluated in laboratory, and a numerical simulation with staged finite element model is conducted to study the feasibility of using the coaxial cable sensing system for monitoring and evaluation of wellbore stability during CO₂ injection.

The real-time distributed sensing system is composed of Fabry-Perot interferometer based …

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)

Global Sensitivity Analysis For A Comprehensive Char Conversion Model In Oxy-Fuel Conditions, Troy Michael Holland, Thomas H. Fletcher

Faculty Publications

Oxy-fired coal combustion is a promising potential carbon capture technology. Predictive CFD simulations are valuable tools in evaluating and deploying oxy-fuel and other carbon capture technologies either as retrofit technologies or for new construction. However, accurate predictive simulations require physically realistic submodels with low computational requirements. In particular, comprehensive char oxidation and gasification models have been developed that describe multiple reaction and diffusion processes. This work focuses on the sensitivity of a recent comprehensive char conversion code named CCK, which treats surface oxidation and gasification reactions as well as the processes such as film diffusion, pore diffusion, ash encapsulation, and …

A Comparison Of Simple Global Kinetic Models For Coal Devolatilization With The Cpd Model, Andrew Richards, Thomas H. Fletcher

Faculty Publications

Simulations of coal combustors and gasifiers generally cannot incorporate the complexities of advanced pyrolysis models, and hence there is interest in evaluating simpler models over ranges of temperature and heating rate that are applicable to the furnace of interest. In this paper, six different simple model forms are compared to predictions made by the Chemical Percolation Devolatilization (CPD) model. The model forms included three modified one-step models, a simple two-step model, and two new modified two-step models. These simple model forms were compared over a wide range of heating rates (5000 to 10⁶ K/s) at final temperatures up to …

Independent Effects Of Surface And Gas Temperature On Coal Fly Ash Deposition In Gas Turbines At Temperatures Up To 1400 C, Robert Laycock, Thomas H. Fletcher

Faculty Publications

Deposition of coal fly ash in gas turbines has been studied to support the concept of integrated gasification combined cycle (IGCC). Although particle filters are used in IGCC, small amounts of ash particles less than 5 microns in diameter enter the gas turbine. Previous deposition experiments in the literature have been conducted at temperatures up to about 1288 C. However, few tests have been conducted that reveal the independent effects of gas and surface temperature, and most have been conducted at gas temperatures lower than 1400 C. The independent effects of gas and surface temperature on particle deposition in a …

Enabling Method To Design Versatile Biomaterial Systems From Colloidal Building Blocks, Shalini Saxena, L. Andrew Lyon

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Development of materials with fine spatial control over topographical, mechanical, or chemical features has been investigated for a variety of applications. Here we present a method to fabricate an array of polyelectrolyte constructs including two-dimensionally and three-dimensionally patterned assemblies using both compressible and incompressible colloidal building blocks. This method eliminates prior constraints associated with specific chemistries, and can be used to develop modular, multi-component, patterned assemblies. In particular, development of constructs were investigated using microgels, which are colloidally stable hydrogel microparticles, polystyrene (PS) beads, and PS-microgel core-shell building blocks in conjunction with the polycation poly(ethyleneimine) (PEI). The topography, mechanical properties, …

Electrochemical Detection Of Antioxidants, Garrett Thompson

Honors Theses and Capstones

No abstract provided.

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 …