Chemical Engineering Commons^™

Synthesis Of Well Dispersed Supported Metal Catalysts By Strong Electrostatic Adsorption And Electroless Deposition, John Meynard Macasero Tengco

Theses and Dissertations

Enhancing the catalytic performance of heterogeneous catalysts can be done by increasing active site count as well as modification of the physico-chemical characteristics of the catalyst material. For supported metal nanoparticles this can be achieved by decreasing particle size, thus increasing dispersion or metal utilization on the surface of the particles, while modification of metal properties can be attained by addition of a secondary metal that has a strong interaction to the primary metal, beneficial for a given reaction. In addition, the accessibility of the metal surface is necessary for reliable performance of catalysts. For carbon supported catalysts, Temperature Programmed …

Development Of A Pressure Swing Adsorption (Psa) Cycle For Co2 Capture From Flue Gas Using A 4-Bed Psa Apparatus, Joshua White

Theses and Dissertations

Pressure swing adsorption is an effective way to capture CO2 from flue gases in energy plants. Pressure swing adsorption utilizes an adsorbent’s selectivity to a specific compound to remove it from a feed stream. Zeolite 13X was used for this research to obtain a high purity and recovery of CO2 at a higher feed flow than previous research. The first part of the work was to use in house FORTRAN based Dynamic Adsorption Process Simulator (DAPS) that uses the finite difference method and the time adaptive Differential- Algebraic Equation (DAE) solver called DASPK to narrow down appropriate experiment criteria for …

Noninvasive Measurement Of Electrical Events Associated With A Single Chlorovirus Infection Of A Microalgal Cell, Seung-Woo Lee, Eun-Hee Lee, Gerhard Thiel, James L. Van Etten, Ravi Saraf

Department of Chemical and Biomolecular Engineering: Faculty Publications

Chlorovirus Paramecium bursaria chlorella virus 1 (PBCV-1) contains a viral-encoded K⁺ channel imbedded in its internal membrane, which triggers host plasma membrane depolarization during virus infection. This early stage of infection was monitored at high resolution by recording the cell membrane depolarization of a single Chlorella cell during infection by a single PBCV-1 particle. The measurement was achieved by depositing the cells onto a network of one-dimensional necklaces of Au nanoparticles, which spanned two electrodes 70 μm apart. The nanoparticle necklace array has been shown to behave as a single-electron device at room temperature. The resulting electrochemical field-effect transistor …

Gallium-Containing Mesoporous Bioactive Glass With Potent Hemostatic Activity And Antibacterial Efficacy, Sara Pourshahrestani, Ehsan Zeimaran, Nahrizul Adib Kadri, Nicola Gargiulo, Shani Samuel, Sangeetha Vasudevaraj Naveen, Tunku Kamarul, Mark R. Towler

Chemical and Biochemical Engineering Faculty Research & Creative Works

Haemorrhage remains the leading cause of potentially survivable death in both military and civilian populations. Although a large variety of hemostatic agents have been developed, many of them have an inadequate capacity to induce hemostasis and are not effective in killing bacteria. In recent years, mesoporous bioactive glasses (MBGs) were found to be effective in inducing hemostasis. However, the materials may not be considered as ideal hemostats since they do not offer antimicrobial activity. The gallium ion (Ga⁺³) not only exhibits antibacterial properties but also accelerates the blood coagulation cascade. The aim of this study was to develop …

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 …

Experimental And Theoretical Investigation Of Sustainable Fast Pyrolysis Biofuels From Woody Biomass, Bethany Jean Klemetsrud

Dissertations, Master's Theses and Master's Reports

Biofuels are an important advancement in alternative energy that can provide substantial environmental benefits compared to their conventional fossil fuel counterparts Said benefits are usually measured using life cycle assessments. However, it is not well understood yet how different methodological choices such as system boundaries, biomass feedstocks, conversion pathways, geographical data, etc. affect the conclusions drawn from biofuels LCA. This research shows large variability in life cycle assessment results and limits comparison across different biofuel pathways due to methodological choices set forth by policy and certification schemes. Advanced biofuels have not reached large scale production due to a limited understanding …

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 …

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)

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, …

Single Phase Gas Flow Response Of Fractured Horizontal And Vertical Wells To Repeated Production, Divya Kandlakunta

Masters Theses

"Historically, the conventional approach to well production has been to produce continuously, minimizing interruptions to flow insofar as possible. Yet some operators have observed improved well flow rates and ultimate recovery after a significant well shut-in periods. These production increases have not been documented. This study investigates the production impact of cyclic production/shut-in on fractured vertical and horizontal gas well performance.

A numerical reservoir model in Stimplan software was used to model production in fracture stimulated vertical and horizontal gas wells. Reservoir permeability is varied over a range of 0.0001 md to 1 md, and the shut-in period was varied …

Computational Fluid Dynamic Analysis In High Permeability Hydraulic Fractured Horizontal Gas Wells, Hrithu Vasudevan

Masters Theses

"Hydraulic fracturing of horizontal wells in unconventional reservoirs has become the dominant type of well completion performed in the United States. In very low permeability reservoirs (~.00001-.0001 mD), the wellbore is aligned with the minimum horizontal stress, and the completion includes multiple transverse fractures. These fractures may be placed with either open hole sleeve type completion systems (OHMS), or cased hole plug and perf systems (P-n-P). In slightly higher permeability reservoirs (1 to 10 mD) multiple longitudinal fractures have been found to be preferred to completions with transverse fractures.

This study presents an evaluation of gas well productivity for both …

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 …

Modelling Hydraulic Fracturing Propagation In Heterogeneous Reservoirs Using Cohesive Zone Methods, Miguel Alejandro Gonzalez-Chavez

LSU Doctoral Dissertations

The recent success in exploiting low permeability shale reservoirs has heavily relied on hydraulic fracturing to produce hydrocarbons economically in disadvantaged reservoir conditions. Although horizontal drilling significantly increases the contact area between the wellbore and the reservoir, the objective of hydraulic fracturing is set on creating further expanded conductive flow paths into the reservoir. This research uses cohesive zone method to numerically simulate hydraulic fracture propagation in the presence of natural fractures in two- and three-dimensional model. The Cohesive element approach limits fracture propagation to some predefined paths. However, in highly fractured formations since hydraulic fractures are growing through a …

Application Of The Finite Element Method To Solve Coupled Multiphysics Problems For Subsurface Energy Extraction, Milad Ahmadi

LSU Doctoral Dissertations

Fractures are a source of extra compliance in the rock mass. Fracture compliance can estimate the fracture roughness and the type of fluid filling the fracture. The focus of this research study in chapter 2 is to illustrate how the compliance ratio of rough fractures can diverge from the compliance ratio of smooth fractures. The imperfect interface of the fracture is modeled with saw-tooth-like structures. The defined saw-tooth-like structures of contact asperities impose an in-plane asymmetry in the shear direction. The compliance ratio of the rough fracture is larger than the compliance ratio of the smooth fracture. Interlocking and riding …

Application Of The Variational Fracture Model To Hydraulic Fracturing In Poroelastic Media, Chukwudi Chukwudozie

LSU Doctoral Dissertations

Hydraulic fracturing has persisted through the use of simple numerical models to describe fracture geometry and propagation. Field tests provide evidence of interaction and merging of multiple fractures, complex fracture geometry and propagation paths. These complicated behaviors suggest that the simple models are incapable of serving as predictive tools for treatment designs. In addition, other commonly used models are designed without considering poroelastic effects even though a propagating hydraulic fracture induces deformation of the surrounding porous media. A rigorous hydraulic fracturing model capable of reproducing realistic fracture behaviors should couple rock deformation, fracture propagation and fluid flow in the both …

Impacts Of Rock-Brine Interactions On Petrophysical Properties Of A Sandstone Reservoir, Utilizing Geochemical And Pore Network Modeling, Masoud Safari-Zanjani

LSU Doctoral Dissertations

Unfavorable consequences of geochemical reactions, such as calcite and silica scaling, in geothermal power plant surface facilities have been discussed in many recent studies. However, the impact of brine-rock interactions related to geothermal projects on reservoir properties has not been addressed fully. In this study, interactions between geothermal fluid and reservoir rocks in two fields located in Vermilion Parish, LA, and Chocolate Bayou, TX, are examined using geochemical modeling. The studied reservoir belongs to the Frio formation. In the geochemical models, the brine is cooled down to the estimated output temperature of a geothermal heat exchanger and re-equilibrated. Then, brine-rock …