Chemical Engineering Commons^™

The Effects Of Low Aspect Ratio And Heat Exchanging Internals On The Bubble Properties And Flow Regime In A Pilot-Plant Bubble/Slurry Bubble Column For Fischer-Tropsch Synthesis, Hayder Al-Naseri

Doctoral Dissertations

"Fischer-Tropsch synthesis (F-T) is a process utilized to convert the syngas mixture of CO and H₂ to synthetic fuel and chemicals that executed commercially by using the bubble/slurry bubble column reactor. The experimental results reveal that the investigated parameters, in terms the presence of internals, and reducing the aspect ratio and the solids loading, increase the local gas holdup, interfacial area, bubble passage frequency, and decrease the bubble rise velocity, bubble chord length. Meanwhile, the aspect ratio H/D = 4, and 5 provide enough height to established the fully developed flow regime. As a result of the variation in …

Using Fluorescence Spectroscopy To Determine Concentrations Of Quantum Dot Solutions, Cameron Sawyer

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Functionalizing Mica With Silanes Using Wet Chemistry, John Paul Stepnowski

Summer Community of Scholars Posters (RCEU and HCR Combined Programs)

No abstract provided.

Cataloging The Degree Of Sensitization Via Electrochemical Reactivation For Studying The Corrosion Behavior Of Inconel 718, Austenitic, And Duplex Stainless Steels, Bradley Lynes

Williams Honors College, Honors Research Projects

Corrosion resistant materials can be expensive, but usually reduce the life cycle cost of metallic assets. However, negligent sensitization of these materials can lead to aggressive, intergranular corrosion. Using the methodology of the double loop electrochemical potentiokinetic reactivation (DL-EPR), this project investigates different steel reinforced bars and Inconel to determine the degree of sensitization after a heat treatment of 900°C for 2 hours. The purpose of this research is to validate and determine the appropriate test parameters for performing further DL-EPR test in the future. Additionally, the kinetics observed for each sample during the DL-EPR test will be analyzed and …

Developing A Portable Prototype To Utilize An Electrospun Colorimetric Sensor For The Detection Of Trihalomethanes In Water, Amanda Svensson

Williams Honors College, Honors Research Projects

Trihalomethane (THM) detection in water is important due to the potential health effects caused by their presence, including increased cancer risk. A cheap, quick, and portable method of identifying THM concentration at the Environmental Protection Agency limit of 80 parts per billion (ppb) will improve detection and water treatment. Electrospinning was used to make nanofiber membranes using a 2.6 wt% polypropylene solution. These membranes were utilized in the Fujiwara reaction, which creates a color change in the presence of THMs, to detect the THM bromoform in water. The color intensity of the reaction was quantified for 250 and 80 ppb …

Effects Of Hofmeister Ions On Transition Temperature Of Two Thermo-Responsive Polymers, Joshua Moser

Williams Honors College, Honors Research Projects

It was hypothesized that through the use of Hofmeister Ions, the lower critical solution temperature (LCST) of poly(vinyl methyl ether) (PVME) and poly(ethylene glycol)- poly(N-isopropylacrylamide) (PEG-b-pNIPAAm) block-copolymer could be controlled. Through literature searches and small lab experiments, our team found that there may be a connection between Hofmeister effects and phase transition of a thermo-responsive polymer. To try and prove this, the lab team decided to take four cations (Mg²⁺,Na⁺, Cs⁺, K⁺) in solution with the thermo-responsive polymers and compared their LCST to solutions of the thermo-responsive polymer in de-ionized …

Requalification Of Coated Fabrics Using Chemlok 2332 In Place Of Chemlok 233, Daniel Madler

Williams Honors College, Honors Research Projects

Rubber coated fabrics are an essential component in the deicing systems of the aerospace industry. Adhesives cements are applied to a fabric prior to being pressed into a rubber compound that will adhere to the fabric. The resulting fabric maintains the strength of the fabric with the added benefits of elasticity and compatibility from the rubber compound. UTC Aerospace Systems relies on these coated fabrics to create safe deicers for the aerospace industry. Chemlok 233, a now obsolete primer cement, was used extensively in the coated fabrics used by UTC. Materials testing and performance evaluation allowed for a replacement cement, …

Form Stable Phase-Change Materials, Russell Dent, Marjan Kashfipour, Nitin Mehra, Jiahua Zhu

Williams Honors College, Honors Research Projects

This work investigates the use of two different polyols, xylitol (Xyl) and erythritol (Ery), in conjunction with boron nitride (BN) aerogels, for the purpose of creating thermally conductive composites. While the BN filler in Xyl composites achieved a high anisotropic thermal conductivity of up to 4.53 W/m-K at 18.2 weight percent filler loading, they do not exhibit good phase-change material qualities due to a low solidification enthalpy even at low cooling rates. Alternatively, the BN-Ery composites have shown promising results with a solidification enthalpy of 225.14 J/g and a melting enthalpy of 385.84 J/g at a heat rate of 5 …

Multidimensional Mass Spectrometry Of Chemonic™ Ccg-6 Nonionic Surfactant With Separation By Polarity And Shape, Charles Johnson

Williams Honors College, Honors Research Projects

Chemonic™ CCG-6 surfactant is a water-soluble poly(ethylene glycol) (PEG) conjugated alkyl glyceride emollient. This surfactant exists as a complex mixture of a glycerol cores conjugated with poly(ethylene glycol) branches (PEGylation) that were partially esterified with caprylic (C8) and capric (C10) acids. These may be esterified on one, two, or all three arms of the glyceride. The architecture of the structures in this mixture was studied using multidimensional mass spectrometry (MS). Mass spectrometry was interfaced with ultra-performance liquid chromatography (UPLC) and ion mobility (IM) separation. The mixture was separated by reversed-phase LC, oligomers of the star-branched polymer were separated according to …

Prevention Of Harmful Algal Blooms By The Mitigation Of Phosphorus Nutrient Loading Via Filtration By Steel Wool And Activated Carbon, Ronald Simpson, Sara Kidd, Samantha Zidd

Williams Honors College, Honors Research Projects

Harmful Algal Blooms (HABs) are a devastating ecological and economic consequence of the abundance of nutrient-rich agricultural runoff entering aquatic ecosystems (Baker et al. 2014). Bio-available phosphorus from synthetic fertilizers is one of the major nutrients contributing to this global issue. Previous studies indicated that dissolved phosphorus can be removed from an aqueous environment when passed through a composite mixture of granular steel wool particles and activated carbon (Erickson, Gulliver, and Weiss, 2007). In this project, we conducted experiments using higher quality concentration measurements to determine what grades of steel wool (SW-0000, SW-000, SW-00) and types of activated carbon (granulated …

New Method Of Manufacturing Carbon Foam, Matthew D. Artimez

Graduate Theses, Dissertations, and Problem Reports (ETD)

Carbon foam is a product that has some unique features. Carbon foam is a light weight material that has a high crush strength. It is electrically conductive, but because it is composed of air space between the tendrils, it is not a thermal conductor. Since it contains no volatile content, it is noncombustible. All these features allow carbon foam to have many modern applications. Currently, there are only three methods of producing carbon foam, and all three are not cost- efficient enough to meet the demand of potential new markets.

In this thesis, a new procedure of producing carbon foam …

Extraction Of Astaxanthin From Engineered Camelina Sativa Seed Using Ethanol-Modified Supercritical Carbon Dioxide, Liyang Xie, Edgar B. Cahoon, Yue Zhang, Ozan Ciftci

Department of Food Science and Technology: Faculty Publications

Natural astaxanthin, a high-value carotenoid that is currently extracted mainly from marine organisms, was extracted from engineered camelina seed using ethanol-modified supercritical carbon dioxide (SC-CO₂) for the first time, and compared with hexane and accelerated solvent extraction using hexane and ethanol. Response surface methodology (RSM) based on central composite rotatable design was employed to investigate the effect of pressure (30–45 MPa), temperature (40–60 °C), and ethanol concentration (10–35%, w/w). RSM-optimized conditions (41.6 MPa, 36.6 °C and 42.0% ethanol concentration) predicted the astaxanthin concentration as 437 μg/g oil, whereas the actual concentration was 421 ± 14 μg/g oil. Astaxanthin …

Reduction Of Nox Emissions In A Single Cylinder Diesel Engine Using Sncr With In-Cylinder Injection Of Aqueous Urea, Anthony Timpanaro

UNF Graduate Theses and Dissertations

The subject of this study is the effect of in-cylinder selective non-catalytic reduction (SNCR) of NO_x emissions in diesel exhaust gas by means of direct injection of aqueous urea ((NH₂)₂CO) into the combustion chamber. A single cylinder diesel test engine was modified to accept an electronically controlled secondary common rail injection system to deliver the aqueous urea directly into the cylinder during engine operation.

Direct in-cylinder injection was chosen in order to ensure precise delivery of the reducing agent without the risk of any premature reactions taking place. Unlike direct in-cylinder injection of neat water, …

Engineering Of Earth-Abundant Electrochemical Catalysts, Dylan D. Rodene

Theses and Dissertations

Alternative energy research into hydrogen production via water electrolysis addresses environmental and sustainability concerns associated with fossil fuel use. Renewable-powered electrolyzers are foreseen to produce hydrogen if energy and cost requirements are achieved. Electrocatalysts reduce the energy requirements of operating electrolyzers by lowering the reaction kinetics at the electrodes. Platinum group metals (PGMs) tend to be utilized as electrocatalysts but are not readily available and are expensive. Ni_1-xMo_x alloys, as low-cost and earth-abundant transition metal nanoparticles (NPs), are emerging as promising electrocatalyst candidates to replace expensive PGM catalysts in alkaline media. Pure-phase cubic and hexagonal Ni_{1-x …}

Process Synthesis And Design Of Integrated Biorefinery In Pulp And Paper Industry, Ghochapon Mongkhonsiri

Chulalongkorn University Theses and Dissertations (Chula ETD)

Integration of biorefinery into pulp and paper industry has been considered as sustainable development for pulp and paper industry and lignocellulosic biorefinery. High value-added biochemical, biofuel and bioenergy productions could be implemented into existing pulp mills by material and utility integration. A systematic methodology employing a superstructure-based process synthesis, process design and innovation is an effective approach to explore potential pathways for both economic and environmental sustainability with support from computer-aided tools. A superstructure of the multi-product biorefinery process network with the pulp and paper industry is developed and optimized with the objective to maximize profit. The synthesis results project …

Techno-Economic Feasibility Analysis Of Hydrogen Recovery In Bio-Hydrogenated Diesel From Palm Oil For Methanol Synthesis Via Aspen Plus, Nitipat Phichitsurathaworn

Chulalongkorn University Theses and Dissertations (Chula ETD)

A bio-hydrogenated diesel (BHD) or green diesel can be produced from refined palm oil obtained from palm oil refinery. A simulation model of BHD production process from palm oil is developed by Aspen Plus. The conventional process which is the heterogeneous catalytic hydro-deoxygenation reaction of triglycerides required high H2/oil volumetric ratio. To reduce high hydrogen loss in gaseous by-product, the design of hydrogen gas recovery process of the BHD process by coupling with methanol synthesis is proposed. The two processes (i.e., conventional BHD process and BHD process coupled with methanol synthesis) are compared in terms of hydrogen recovery and economic …

Pre-Feasibility Study Of Improving Quality Of Low-Grade Fluorite. A Case Study At Phanomthuan Deposit, Kanchanaburi, Thailand, Keosaychai Souvannavong

Chulalongkorn University Theses and Dissertations (Chula ETD)

In this study was presented the pre-feasibility study of improving quality of low-grade fluorite from Phanomthuan deposit, Kanchanaburi province, Thailand. The purpose of this study aims to explore the optimal condition in order to remove the impurities which contained high SiO2, CaCO3 and other minerals, also evaluate the project in term of economic. Therefore, the improvement quality of fluorite by using froth flotation techniques was reach the ceramic grade. The raw material characterization contains CaF2 = 29.4 Wt.%, SiO2 = 43.9 Wt.% and CaCO3 = 6.9 Wt.%. After flotation process the optimal condition result which contains CaF2 = 96.46 Wt.%, …

Void Fraction Measurements In Large (0.3 M) Diameter Bubble Column Using Wire Mesh Sensor And Pressure Transducers- Effect Of Sparger, Afolabi Gabriel Ojo

Dissertations and Theses

The importance of the accurate temporal and spatial measurements of the two-phase flow parameters in bubble columns is very well known. The aim of this research work is to report the spatial measurements of the void fraction distribution in a 30 cm diameter cylindrical bubble column using Wire Mesh Sensor (WMS) tomography and Pressure Transducers. Pair of WMS sensors, with a 64×64 wire configuration of each sensor, were installed which are separated by a distance along the axis of the bubble column. Wire Mesh Sensors and PTs Data were collected for time-averaged and transient with a sampling frequency of 1000 …

Air Ingress And Heat-Driven Flow Relaminarization In A Very High Temperature Reactor (Vhtr), Apoorva Rudra

Dissertations and Theses

Very High Temperature Reactors (VHTRs) are one of six Generation IV reactors that have been proposed for DOE’s Next Generation Nuclear Plant. In addition to using gaseous coolants, VHTRs also display benefits of passive safety systems including intra-core natural circulation for heat removal in accident scenarios. However, a number of substantial engineering challenges are expected in VHTRs, and due to the high temperatures of the coolant involved, material behavior in various components needs to be better understood. Our work focuses mainly on two key phenomena that could lead to localized hot spots in the VHTR reactor core if not addressed …

Electrochemical Properties Of Crystalline Polymorphs Of Mno2 In Aluminum And Zinc Metal Batteries, Subhadip Pal

Dissertations and Theses

The widespread use of non-renewable fossil fuels has led to societal problems like global warming and climate change. Electrochemical energy storage can enable the integration of renewable energy sources that are inherently intermittent (solar, wind, etc.) into the electric grid, though major advances in cost, cycle life, and safety are necessary to have a global impact on the energy landscape. Both aluminium (Al) and zinc (Zn) metals are earth abundant, low-cost, safe, and exhibit high coulombic capacities, which make them promising electrode materials for “beyond lithium-ion” battery chemistries. However, the electrochemical feasibility and charge storage mechanisms of alternative Al and …