Chemical Engineering Commons^™

Tactical Missile Performance For Single And Multi-Wire Embedded Propellant Configurations With Discontinuities, Paul B. Wilson

Theses and Dissertations

This research analyzes the performance of a nominal air-to-air tactical missile with varying configurations of wire-embedded end-burning solid propellant grains. Single and multi-wire models are developed to determine if total impulse and range is improved. Discontinuities in the wires are simulated to determine if gaps in the wire will affect overall performance. Five wire materials, seven wire diameters, and nine different break locations are tested. This research demonstrates wire discontinuities have negligible impact on performance and carbon nanotube fibers can theoretically improve total impulse by up to 25% compared to radially burning boost-phase grains while providing similar thrust outputs.

Effect Of Support, Preparations Methods, Ag Promotion And Nc Size On The Activity, Selectivity And Sintering Deactivation Of Supported Co Fischer-Tropsch Catalyst, Mahmood Rahmati

Theses and Dissertations

A series of silver-promoted, 20 wt% cobalt Fischer-Tropsch synthesis (FTS) catalysts supported on an alumina modified with 5 wt% silica were prepared using two methods: traditional incipient wetness impregnation (IWI) and a new solvent-deficient precipitation (SDP) technique. Catalysts containing silver promoter concentrations of 0.3, 0.6, 1.2, and 2.5 wt% were prepared using each of the two methods. Silver improved the reducibility of the cobalt significantly, lowering reduction temperatures by up to 100°C, and increasing the extent of reduction by up to 35%. Further, in both preparation methods, changing the silver loading altered the cobalt dispersion. The smallest Co crystallite size …

Carbon Capture And Synergistic Energy Storage: Performance And Uncertainty Quantification, Christopher Stephen Russell

Theses and Dissertations

Energy use around the world will rise in the coming decades. Renewable energy sources will help meet this demand, but renewable sources suffer from intermittency, uncontrollable power supply, geographic limitations, and other issues. Many of these issues can be mitigated by introducing energy storage technologies. These technologies facilitate load following and can effectively time-shift power. This analysis compares dedicated and synergistic energy storage technologies using energy efficiency as the primary metric.
Energy storage will help renewable sources come to the grid, but fossil fuels still dominate energy sources for decades to come in nearly all projections. Carbon capture technologies can …

Capillary Forces In Partially Saturated Thin Fibrous Media, Ali Moghadam

Theses and Dissertations

Capillarity is often exploited in self-cleaning, drag reducing and fluid absorption/storage (sanitary products) purposes just to name a few. Formulating the underlying physics of capillarity helps future design and development of optimized structures. This work reports on developing computational models to quantify the capillary pressure and capillary forces on the fibrous surfaces. To this end, the current study utilizes a novel mass-spring-damper approach to incorporate the mechanical properties of the fibers in generating virtual fibrous structures that can best represent fibrous membranes. Such virtual fibrous structures are then subjected to a pressure estimation model, developed for the first time in …

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 …}

Modeling Electrospun Fibrous Materials, Sina Hassanpouryousefi

Theses and Dissertations

Electrospinning has been the focus of countless studies for the past decades for applications, including but not limited to, filtration, tissue engineering, and catalysis. Electrospinning is a one-step process for producing nano- and/or micro-fibrous materials with diameters ranging typically from 50 to 5000 nm. The simulation algorithm presented here is based on a novel mass-spring-damper (MSD) approach devised to incorporate the mechanical properties of the fibers in predicting the formation and morphology of the electrospun fibers as they travel from the needle toward the collector, and as they deposit on the substrate. This work is the first to develop a …

The Creation, Validation, And Implementation Of The Engineering Process Safety Research Instrument, Brittany Lynn Butler

Theses and Dissertations

The purpose of this study was to develop and validate an instrument that can measure how senior chemical engineering students make process safety decisions. The Engineering Process Safety Research Instrument (EPSRI) contains dilemmas that represent process safety scenarios, followed by three decision options, and 12-15 considerations that fall into pre-conventional, conventional, or post-conventional forms of reasoning. Three studies were completed as a part of this research. The content validation study ensured the dilemmas represented process safety scenarios, the considerations matched their perceived theoretical definitions, and that no content areas were omitted. This study resulted in validation of the content, following …

Repopulation And Stimulation Of Porcine Cardiac Extracellular Matrix To Create Engineered Heart Patches, Silvia Juliana Moncada Diaz

Theses and Dissertations

Heart failure is the main cause of death for both men and women in the United States. The only proven treatment for patients with heart failure is heart transplantation. The goal of this research is to create patches of tissue that could mimic the function of the native heart to repair the damaged portions of the heart. In this study, whole porcine hearts were decellularized to create a 3D construct that was recellularized with cardiomyocytes (CM) differentiated from human induced pluripotent stem (IPS) cells. At day 4 of differentiation, IPS-derived CMs were implanted onto cardiac extracellular matrix (cECM) and ten …

Characterization Of Pyrolysis Products From Fast Pyrolysis Of Live And Dead Vegetation, Mohammad Saeed Safdari

Theses and Dissertations

Wildland fire, which includes both planned (prescribed fire) and unplanned (wildfire) fires, is an important component of many ecosystems. Prescribed burning (controlled burning) is used as an effective tool in managing a variety of ecosystems in the United States to reduce accumulation of hazardous fuels, manage wildlife habitats, mimic natural fire occurrence, manage traditional native foods, and provide other ecological and societal benefits. During wildland fires, both live and dead (biomass) plants undergo a two-step thermal degradation process (pyrolysis and combustion) when exposed to high temperatures. Pyrolysis is the thermal decomposition of organic material, which does not require the presence …

Rapid Separation Of Bacteria From Blood For Sepsis Diagnosis, Mahsa Alizadeh

Theses and Dissertations

Sepsis is a severe blood infection caused by bacteria entering the blood stream. Sepsis caused by antibiotic resistant bacteria is very dangerous with a high mortality rate. The current clinical diagnostic methods for sepsis require culturing the blood sample prior to other steps of the diagnosis procedure. Culturing the blood samples is a time-consuming step which increases the time required for the diagnostic procedure. Considering the fact that the mortality rate of the sepsis increases as time passes, it is essential to find methods for sepsis diagnosis that do not require culturing the samples. The first step of a new …

Large-Scale Non-Linear Dynamic Optimization For Combining Applications Of Optimal Scheduling And Control, Logan Daniel Beal

Theses and Dissertations

Optimization has enabled automated applications in chemical manufacturing such as advanced control and scheduling. These applications have demonstrated enormous benefit over the last few decades and continue to be researched and refined. However, these applications have been developed separately with uncoordinated objectives. This dissertation investigates the unification of scheduling and control optimization schemes. The current practice is compared to early-concept, light integrations, and deeper integrations. This quantitative comparison of economic impacts encourages further investigation and tighter integration. A novel approach combines scheduling and control into a single application that can be used online. This approach implements the discrete-time paradigm from …

Optimization-Based Spatial Positioning And Energy Management For Unmanned Aerial Vehicles, Ronald Abraham Martin

Theses and Dissertations

This research applies techniques from the field of optimization to spatial positioning and energy management in Unmanned Aerial Vehicles (UAVs). Two specific areas are treated: optimization of UAV view plans for 3D modeling of infrastructure, and trajectory optimization of solar powered high-altitude long-endurance (HALE) UAVs. Structure-from-Motion (SfM) is a computer vision technique for creating 3D models from 2D images. View planning is the process of planning image sets that will effectively model a given scene. First, a genetic algorithm based view planning approach is demonstrated. A novel terrain simulation environment is developed, and the algorithm is tested at multiple sites …

An Investigation Of Conformality Of The Core-Shell Polymer Electrolyte Membrane (Pem) Fuel Cell Catalysts By Sputter Deposition, Mesut Yurukcu

Theses and Dissertations

Core-shell nanorod array geometry can offer enhanced durability for polymer electrolyte membrane (PEM) fuel cell electrodes if a catalyst shell is conformally coated around the nanorod support base. Uniform catalyst shell coating can minimize the interaction of acidic fuel cell medium with the nanorod base and can improve the overall electrocatalyst electrode stability. However, fabrication of the conformal shell layers on nanorod arrays using physical vapor deposition (PVD) methods (e.g. sputtering, thermal evaporation) has been a formidable task. In order to assess the PVD conditions for the production of conformal shell coatings, Monte Carlo simulation methods (MC) can provide useful …

Modeling Soot Formation Derived From Solid Fuels, Alexander Jon Josephson

Theses and Dissertations

Soot formation from complex solid fuels, such as coal or biomass, is an under-studied and little understood phenomena which has profound physical effects. Any time a solid fuel is combusted, from coal-burning power plants to wildland fires, soot formation within the flame can have a significant influence on combustion characteristics such as temperature, heat flux, and chemical profiles. If emitted from the flame, soot particles have long-last effects on human health and the environment. The work in this dissertation focuses on creating and implementing computational models to be used for predicting soot mechanisms in a combustion environment. Three models are …

Three-Way Catalysts In Passive Selective Catalytic Reduction Systems, Calvin Thomas

Theses and Dissertations

Conventional gasoline-powered engines operate with a stoichiometric air-fuel ratio (AFR), but greater fuel economy is achieved in lean burn engines by increasing the AFR. The primary drawback to these engines is the nitrogen oxide (NOX) emissions, which cannot be reduced over a conventional three-way catalyst (TWC). Passive selective catalytic reduction (SCR) is a promising approach for the control of NOX emissions in lean burn systems. By periodically decreasing the AFR to fuel-rich levels, ammonia (NH3) can be produced over a TWC and stored on a downstream SCR catalyst for the reduction of NOX during normal lean operation. While passive SCR …

Thermochemical Conversion Of Biomass: Detailed Gasification And Near-Burner Co-Firing Measurements, Jacob B. Beutler

Theses and Dissertations

An increasing emphasis on mitigating global climate change (global warming) over the last few decades has created interest in a broad range of sustainable or alternative energy systems to replace fossil fuel combustion. Biomass, when harvested responsibly, is a renewable fuel with many uses in replacing fossil fuels. Cofiring biomass with coal in traditional large-scale coal power plants represents one of the lowest risk, least costly, near-term methods of CO₂ mitigation. Simultaneously, it is one of the most efficient and inexpensive uses of biomass. Alternatively, biomass can be transformed into useful products through gasification to produce clean syngas for …

Arrhenius Rate Chemistry Informed Inter-Phase Source Terms (Arciist) For Macro-Scale Explosive Hydrocodes, Matthew J. Schwaab

Theses and Dissertations

A critical factor in hydrocodes designed to simulate explosive material is defining the chemical reaction rate under various conditions. This rate determines how quickly the granular solid explosive is converted to its gaseous products. Currently, the state of the art for macro-scale hydrocodes is to use one of numerous burn models. These burn models are designed to estimate the bulk chemical reaction rate. Unfortunately, these burn rate models are largely based on empirical data and must be recalibrated for every new material being simulated. This research proposes that the use of Arrhenius Rate Chemistry Informed Interphase Source Terms (ARCIIST) in …

Homogeneous Reaction Kinetics Of Carbohydrates With Viologen Catalysts For Biofuel Cell Applications, Hilary Bingham

Theses and Dissertations

Energy usage is continually on the rise and significant efforts are being extended to provide more renewable energy. One area of exploration is the development of fuel cells, which includes biofuel cells that can extract energy from carbohydrates obtained from biomass. Recently, viologen catalysts have been shown to enhance reaction rates of energy extraction and improve carbohydrate conversion efficiencies. However, characterizing the effects of process parameters such as pH, reactant concentrations, and carbohydrate exposure time to buffer solutions with a rigorous model is lacking. This thesis characterizes the homogeneous reaction between carbohydrates and a methyl viologen catalyst to provide insights …

Smart Technologies For Oil Production With Rod Pumping, Brigham Wheeler Hansen

Theses and Dissertations

This work enables accelerated fluid recovery in oil and gas reservoirs by automatically controlling fluid height and bottomhole pressure in wells. Several literature studies show significant increase in recovered oil by determining a target bottomhole pressure but rarely consider how to control to that value. This work enables those benefits by maintaining bottomhole pressure or fluid height. Moving Horizon Estimation (MHE) determines uncertain well parameters using only common surface measurements. A Model Predictive Controller (MPC) adjusts the stroking speed of a sucker rod pump to maintain fluid height. Pump boundary conditions are simulated with Mathematical Programs with Complementarity Constraints (MPCCs) …

Isru Thermal-Driven Processes On Interplanetary Surfaces And Characteristics On Production Of Commodities, Jesus A. Dominguez

Theses and Dissertations

Extraterrestrial In-Situ Resource Utilization (ISRU) is a primary area of interest to enable successful exploration, mining, and human settling in space missions. Native extraterrestrial conditions, such as vacuum conditions and low gravity are challenging as their effects on workable-scale ISRU operations are basically unknown. This dissertation research work studied three thermal-driven properties on JSC-lA lunar regolith simulant at pilot-plant-­scale under vacuum (a native ambient condition on the moon and asteroids): (1) gasification and decomposition of regolith's components that have the potential of generating gaseous oxygen, metals, and alloys without the necessity of terrestrial precursors, (2) vacuum void formation during the …

Process Intervention For Water Recovery In Food Manufacture, Christian Michael Wisniewski

Theses and Dissertations

A case study has been conducted for the recovery of water from complex wastewater at a soluble coffee manufacturing factory. The study has evaluated separation methods for process intervention based on environmental and economic assessments. Water recovery was identified in two possible wastewater streams at the factory: the overall plant effluent and an intermediate stream before it enters on-site pre-treatment. A novel vibratory field membrane separation was tested at the laboratory scale using real factory wastewater and scaled-up using appropriate design protocols. Recovery of water from the intermediate stream proved the most effective, both environmentally and economically. The full-scale vibratory …

Suitability Of The Kalina Cycle For Power Conversion From Pressurized Water Reactors, Jack Ryan Webster

Theses and Dissertations

The primary objective of this work is to determine the Kalina cycle's suitability for thermal power conversion from a pressurized water reactor. Several previous papers have examined this application, but these either lack proof of concept or make unfeasible assumptions. This work expands current knowledge by simulating the Kalina cycle and comparing it to current pressurized water reactor Rankine cycles in order to identify which is more efficient. Prerequisite to the modeling is a simulation tool capable of modeling the thermodynamics of ammonia/water mixtures. Instead of using an existing program, a new one called Clearwater is used. This tool is …

Nonlinear Model Predictive Control For A Managed Pressure Drilling With High-Fidelity Drilling Simulators, Junho Park

Theses and Dissertations

The world's energy demand has been rapidly increasing and is projected to continue growing for at least the next two decades. With increasing global energy demand and competition from renewable energy, the oil and gas industry is striving for more efficient petroleum production. Many technical breakthroughs have enabled the drilling industry to expand the exploration to more difficult drilling such as deepwater drilling and multilateral directional drilling. For example, managed pressure drilling (MPD) offers ceaseless operation with multiple manipulated variables (MV) and wired drill pipe (WDP) provides two-way, high-speed measurements from bottom hole and along-string sensors. These technologies have maximum …

Simulation And Experiments To Understand The Manufacturing Process, Microstructure And Transport Properties Of Porous Electrodes, Mohammad Mehdi Forouzan

Theses and Dissertations

Battery technology is a great candidate for energy storage applications. The need for high-performance and cost-effective batteries has motivated researchers to put much effort into improving battery performance. In this work, we attempt to understand the elements that affect the microstructure and performance of two battery systems. The first part of this work focuses on the investigation of transport and structural properties of porous electrodes in an alkaline electrolyte. A DC polarization method was deployed for tortuosity measurements. An apparatus was designed to flow specified current through and measure the voltage drop over the porous electrodes. Using a modified Ohm's …

Hydrodeoxygenation Of Acetic Acid Using Monometallic And Bimetallic Catalysts Supported On Carbon, José Luis Contreras Mora

Theses and Dissertations

Heterogeneous catalytic hydrodeoxygenation (HDO) of biomass-derived feeds is a deoxygenation process that is of highly interest. Carboxylic acids are one of the main components of bio-oils and acetic acid is one of the most abundant of these carboxylic acids. This acid is rich in oxygen, therefore a lot of research to produce fuel and other valuable chemicals such as ethanol is of interest.

This dissertation explores the gas-phase catalytic HDO of AA over catalysts supported on activated carbon (Cp-97). Temperature-dependent conversion and selectivity were studied at 1 atm from 200-400⁰C with an AA concentration of 1.1% and 20% …

Role Of Bed Design Characteristics On The Effective Thermal Conductivity Of A Structured Adsorbent, Pravin Bosco Charles Antony Amalraj

Theses and Dissertations

This work evaluates the role of different design variables on the effective thermal conduction of a structured adsorbent bed for its possible application in a temperature swing adsorption (TSA) process. The structured adsorbent bed is represented by eight parallel layers of intercalated smooth and corrugated foils of a metal support coated with 13X zeolite resulting in the formation of parallel triangular channels. The variables investigated include the thickness of the adsorbent coating, thickness of the metal, nature of contacts between smooth and corrugated foils, type of metal, presence and magnitude of an air gap between the foils, difference in alignment …

Combinatorial Study Of Oxidation Catalysts: Uncovering Synthesis-Structure-Activity Relationships, Kathleen B. Mingle

Theses and Dissertations

High throughput experimentation (HTE) in catalysis has proven useful in expediting materials discovery via parallelized synthesis, characterization, and testing of candidate materials. However, even in a high-throughput manner, the combinatorial explosion of relevant parameters far exceeds our ability to study. To further complicate the problem, a large time investment and great deal of characterization is often required to build an in-depth understanding of catalytic materials. It follows that the field of heterogeneous catalysis is rich with examples of catalytic systems that have been developed using trial and error efforts for which a lot is known but context is lacking. Techniques …

Understanding Early Amyloid-Ss Aggregation To Engineer Polyacid-Functionalized Nanoparticles As An Inhibitor Design Platform, Nicholas Vander Munnik

Theses and Dissertations

Alzheimer’s disease (AD) is characterized by the presence of amyloid-ß (Aß) protein aggregates in the brains of those afflicted. This protein aggregates via a complex pathway to progress from monomers to soluble oligomers and ultimately insoluble fibrils. Due to the dynamic nature of aggregation, it has proven exceedingly difficult to determine the precise interactions that lead to the formation of transient oligomers. A statistical thermodynamic model has been developed to elucidate these interactions. Aß was simulated using fully-atomistic replica exchange molecular dynamics. We use an ensemble of 5 × 105 configurations taken from these simulations as input for a self-consistent …

Development Of Bimetallic Catalysts For Dry Reforming Of Methane And Hydrogenation Of Succinic Acid, Jayson Michael Keels

Theses and Dissertations

Advances in natural gas recovery have greatly impacted the global economy; the abundant supply of gas has revealed new opportunities and challenges in a wide range of markets within the fuels and chemicals industries. One such opportunity exists with the overabundance of gas from remote wells that is flared or emitted because of the high costs associated with transportation of a chemical with such a high molar volume. A possible solution is an on-site process to convert gas to higher value chemicals that are liquid at standard conditions, and can more easily be transported. As a first step, CO2 from …

Selective Deposition Of Platinum By Strong Electrostatic Adsorption Onto Cobalt- And Iron-Based Catalysts For Fischer-Tropsch Synthesis, Fahad A. Almalki

Theses and Dissertations

Cobalt and iron based catalysts are commercially predominant for Fischer-Tropsch synthesis, Co-based catalysts for their stability, activity, and inactivity for the water gas shift reaction and Fe-based catalysts for their cheap cost, high light-olefins and alcohols selectivity, and tolerance to H2/CO ratio. These catalysts are structure sensitive with lower activity at nanoparticle sizes smaller than 6-8 nm. Co-based catalysts exhibit high activity, low CH4 selectivity, and high C5+ selectivity, while Fe-based catalysts are more selective to low-molecular-weight hydrocarbons such as olefins and alcohols. The reducibility of cobalt and iron is another important factor which may be key for improving their …