Engineering Commons^™

Assessing The Thermodynamic Potential Of Deep Eutectic Solvents In The Absorption Of Greenhouse Gases Through Computational Methods., Thomas Michael Quaid

Theses and Dissertations

Greenhouse gas (GHG) capture is a fundamental technology in the fight against climate change. Some species of devastating GHGs like fluorinated compounds are released directly to the air from industrial processes. Some GHGs are co-produced in sustainably derived biofuels which require absorptive upgrading. The development of more efficient, cost effective, and environmentally friendly methods of capturing GHG’s from pollutant sources and industrial streams is of utmost importance in the fight against climate change. Deep eutectic solvents have entered the separations stage as potential disruptors to conventional solvent choices for a variety of applications. Deep eutectic solvents (DES) are compounds of …

Assessing The Thermodynamic Potential Of Deep Eutectic Solvents In The Absorption Of Greenhouse Gases Through Computational Methods, Thomas Michael Quaid

Theses and Dissertations

Greenhouse gas (GHG) capture is a fundamental technology in the fight against climate change. Some species of devastating GHGs like fluorinated compounds are released directly to the air from industrial processes. Some GHGs are co-produced in sustainably derived biofuels which require absorptive upgrading. The development of more efficient, cost effective, and environmentally friendly methods of capturing GHG’s from pollutant sources and industrial streams is of utmost importance in the fight against climate change. Deep eutectic solvents have entered the separations stage as potential disruptors to conventional solvent choices for a variety of applications. Deep eutectic solvents (DES) are compounds of …

Dechlorination Of Waste Pvc (Polyvinyl Chloride) Using Hydrothermal Liquefaction Method, Vahab Ghalandari

Theses and Dissertations

In 2019, waste plastic production in the United States (U.S.) amounted to approximately 73 million metric tons. Projections indicate that by 2030, the generation of waste plastic in the U.S. will increase to nearly 90 million metric tons, and by 2060, it is expected to surpass 140 million metric tons. One prominent type of waste plastic is polyvinyl chloride (PVC), characterized by its high chlorine content, making it a halogenated plastic. This dissertation presents a comprehensive investigation of the dechlorination of waste PVC (WPVC) through various hydrothermal liquefaction (HTL) methods to produce environmentally friendly solid and liquid products. In this …

Waste Biomass-Derived Ultraporous Functionalized Superactivated Hydrochars For Hydrogen Storage And Carbon Capture, Al Ibtida Sultana

Theses and Dissertations

Accelerating world population and simultaneous growth in economic race has resulted in parallel rise of waste generation where the necessity of mitigating the climate change, via transitioning towards a clean energy economy and minimization of greenhouse gas from atmosphere, is in urgent need of attention. Hence, the objectives of this dissertation comprised of firstly upcycling waste biomass into low-cost and effective adsorbent material such that, secondly, its surface could be tailored by modulating its synthesis conditions (hydrothermal carbonization and chemical activation) to be developed into ultraporous and functionalized adsorption medium in order to, thirdly, assess its application as adsorbents for …

Hydrothermal Preprocessing Of Waste Corn Stover Into Advanced Biorefinery Feedstock, Md Tahmid Islam

Theses and Dissertations

Waste corn stover is one of the most abundant agronomic resources in U.S., however, those are either incinerated or unprocessed in the field to avoid high logistical cost, economic forfeiture, and environmental complications. Hydrothermal carbonization (HTC) is a promising thermochemical process that transforms wet biomass like waste corn stover into a solid fuel called hydrochar, process liquid, and process gas. The recycle of process liquid is warranted as the HTC process liquid contains organic acid that would increase the mass yield and fuel quality of the hydrochar by catalyzing the HTC reactions. HTC also promotes the fuel quality by densifying …

Understanding The Reaction Kinetics Of Polyurethane Flexible Foam, Caitlin Alma Mckinnon

Theses and Dissertations

Polyurethane flexible foam is used throughout daily life predominantly as cushions for chairs and mattresses. Currently new foams are made through extensive research and development via trial and error. There are many reactions interacting with each other during the polyurethane generation process. The numerous reactions create difficulty in modeling and predicting the physical attributes of a foam. This thesis explores the kinetics associated with each reaction to generate a simple model to understand the reaction kinetics with the addition of some additives. This thesis focused on creating the foams in a real-world environment, including allowing ambient water vapor to be …

A Compact Natural Gas Pyrolysis Reactor For Hydrogen Fueling Stations, Andrew Richard Earls

Theses and Dissertations

With the increasing amount of greenhouse gases causing more natural disasters and sea level rise, there is a clear need for a global energy transition to less polluting fuels. A possible solution to this problem is converting a portion of the transportation sector fuel to hydrogen. In this thesis, the issues associated with such a transition are discussed and reasonable solutions are proposed. Numerous methods of hydrogen production are explored and compared on the basis of electricity consumption and CO2 emission. A plant size of 1250 kg liq. H2/day is chosen based on California regulated hydrogen refueling credits (HRI) that …

3d Printed Bioglass Incorporated Collagen Matrices For Musculoskeletal Tissue Engineering, Nilabh Sunil Kajave

Theses and Dissertations

Musculoskeletal injuries are a major cause of disability affecting millions of people around the world and resulting in a significant economic burden of over $14 billion. Surgical intervention using autografts and allografts is the current gold standard used in the clinic for the repair and regeneration of musculoskeletal injuries, but these treatment options are associated with major limitations such as donor-site morbidity, need for multiple surgeries, immune-related complications, and risk for disease transmission. Over the past three decades, the development and application of tissue engineering strategies for restoration and reconstruction of damaged or diseased musculoskeletal tissues have gained considerable momentum …

Behavior Of Selective Oxygen Functional Groups Upon Hydrothermal Carbonization And Pyrolysis Of Biomass And Their Roles On Selective Applications, Nepu Saha

Theses and Dissertations

Hydrothermal carbonization (HTC) is a thermochemical process where biomass is treated in water under high temperature and corresponding vapor pressure. During HTC, biomass undergoes a series of reactions including hydrolysis, decarboxylation, dehydration, aromatization, and polymerization. As a result, a solid product is produced from biomass after HTC process, which is widely known as hydrochar. Depending on the HTC process conditions, a wide-variety of oxygen-containing groups formed on hydrochar surfaces. Many of these groups could play critical roles in applications such as adsorption, and energy and gas storage, etc. However, not all functional groups are exposed on the surface due to …

Experimental And Computational Investigations Of Type Iii Deep Eutectic Solvents For Btx Removal From Light Naphtha, Kyle Mcgaughy

Theses and Dissertations

Light naphtha is a crucial chemical feedstock that is used to make value-added products from plastic to fuels. Whether it is derived from fossil fuels or renewable resources, naphtha typically contains small fraction of aromatic contaminants such as benzene, toluene, and xylene (BTX). Polar solvents such as sulfolane, ethylene glycol, and glycerol are industrially used to separate BTX from naphtha. Each of these solvents has some processing difficulties though, whether it be sulfolane degrading and corroding equipment or ethylene glycol and glycerol not being particularly selective for BTX over light naphtha. Some of the traditional solvents used for naphtha purification …

Design Of A System For Inexpensive Underwater Fiber Optic In Vivo Imaging And Mass Balance Accounting Of Tissue Engineering Candidates, Nicole Melissa Bueno Guerrero

Theses and Dissertations

The goal of this project is to create a prototype bioreactor that mimics a cell’s microenvironment. The ultimate goal is to set up an array of 36 bioreactors in parallel and monitor them with an array of sensors that will enable full mass and energy balance accounting and in vivo imaging. This thesis will analyze the various options available for cell imaging, as well as describe the construction of a bioreactor design in which cell images can be obtained without removing the cells from the bioreactor. The hypothesis for this project is that imaging of unstained cells in an aquarium …

Electrochemical Fabrication Of Elastin-Containing Bi-Layered Scaffold For Vascular Tissue Engineering Applications, Thuy-Uyen Ky Nguyen

Theses and Dissertations

Lack of a viable vascular graft for the replacement of diseased small diameter blood vessels (< 4 mm) has encouraged the development of a self-repairing tissue engineered vascular graft (TEVG) as a promising alternative source. Although many different fabrication approaches have been devised to generate TEVGs using both natural and synthetic biomaterials, a functional TEVG that can serve as an effective replacement of diseased small-diameter blood vessels (< 4 mm) is still elusive mainly due to concerns associated with thrombosis and intimal hyperplasia. One approach to improve the clinical outcome of vascular grafts is to develop a 3D biomimetic scaffold that provides the essential physicochemical cues (i.e., compositional, topographical) to modulate cellular response (i.e., cell phenotype, endothelialization, de novo elastic matrix production) and thereby aid in tissue repair and remodeling. This approach entails the development of a novel 3D scaffold that provides an aligned collagen platform to guide smooth muscle cell (SMC) orientation

and insoluble elastic matrix (i.e., native form of elastin) to promote SMC contractility and thereby prevent overproliferation and hence alleviate concerns with intimal hyperplasia. In addition, the scaffold must comprise of a smooth luminal side to support the formation of a continuous endothelium that is essential to prevent thrombosis. Most existing biofabrication methodologies to generate vascular scaffolds (e.g., extrusion, electrospinning) have limited scope because of the inability to incorporate insoluble elastic matrix within the aligned collagen framework due to the disparity in the size …

Validation Of An External Bioreactor Filtration Loop Prototype For A Tissue Engineering Test Bed, Jonah Martin Melegrito

Theses and Dissertations

As a cell line thrives within a culture, some of the cells undergo the natural process of death. Whether it is due to apoptotic or necrotic causes, cell death is a significant hurdle for tissue engineering and cell cultivation. When cells attached to a scaffold die, they slough off from the scaffold into the bloodstream. If left unchecked, these dead cells and any cellular waste products accumulate and could affect the living cells’ ability to survive. The objective of this thesis was to construct a separation system that can filter away any unwanted suspended solids while allowing nutrients to recycle …

Residence Time Distribution (Rtd) Analysis Of A Bioreactor's External Recirculation Loop For A Tissue Engineering Test Bed, Adrien Hosking

Theses and Dissertations

Currently, in tissue engineering, the focus is on morphing cells into a particular type of tissue by hand, rather than automating the process. Automating cell feeding and waste removal, alone, still requires the removal of cells from their culture to perform imaging and analysis. Without the ability to automate the imaging in a way that does not risk cell death, the advantages of automating the feeding and waste removal are largely lost. By building a fully automated tissue engineering test bed, the capacity for cell reproducibility and cell yield increases significantly. This thesis outlines the design, some initial testing, and …

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 …

Effect Of Bioglass Incorporation Into Electrochemically Aligned Collagen Threads On Mechanical Properties And Cell-Mediated Mineralization, Madhura Nijsure

Theses and Dissertations

Bone related diseases and disorders are a significant socioeconomic burden in the United States. Autografts and allografts are most commonly used for the treatment of bone defects and non-unions; however, they are associated with limitations such as donor site morbidity and immune rejection, respectively. Over the past few decades, bone tissue engineering (BTE) using scaffold and cells has garnered significant interest as an alternative method for the repair and regeneration of bone defects. Recreation of the tissue microenvironment via the development of biomimetic scaffolds that resemble the physicochemical aspects (i.e., composition, topography, stiffness) of native bone is a promising approach …

Assessing The Effects Of Sensitizing Tungsten Oxide With Zinc Telluride, Chengeto Kazuva

Theses and Dissertations

This thesis is a comparison study of the performance of plain tungsten oxide (WO₃) thin films and tungsten oxide thin films sensitized with zinc telluride (ZnTe) as photoelectrocatalysts. Tungsten oxide and zinc telluride are semiconductors which were prepared on indium tin oxide (ITO) coated glass, and subsequently studied for water splitting applications. The main method of synthesis employed was electrochemical deposition. Tungsten oxide thin films were deposited from a precursor solution of peroxotungstic acid while the zinc telluride thin films were deposited from a solution containing dissolved zinc sulfate heptahydrate, sulfuric acid and tellurium dioxide. Surface morphology, film composition and …

An Analysis Of Capital Cost Estimation Techniques For Chemical Processing, Omar Joel Symister

Theses and Dissertations

This research serves to compare the use of the capital cost estimation software, Aspen Capital Cost Estimator (ACCE), with other capital cost estimating methods specifically the module costing technique outlined by Richard Turton et al. and also a factorial costing technique outlined by Gavin Towler and Ray Sinnott. This study will compare popular process equipment found in the chemical process industries. The relationship between the capacities of the equipment, as it relates to the cost as well as operational pressures and materials of construction (MOC), will also be obtained and compared. The results of this study may be used by …

Design Of A Light-Weight Low-Volume High Oxygen Storage Density Material, Nicholas Robert Schwartz

Theses and Dissertations

A compact, lightweight, dense and safe method for storing and supplying oxygen remains a large hurdle for closed-circuit self-contained breathing apparatus (SCBA) and respiratory protective equipment. No filter that can protect against airborne chemical, biological, radiological, and nuclear (CBRN) contaminants exists, which presents the need for an isolated oxygen source. Heavy and high maintenance oxygen cylinders are typically used. The most important criteria for a smart and effective CBRN protection device are safety, weight, size, and cost, level of maintenance, ease-of-use and reliability. This study focused on nanomaterials for high capacity gas storage. Nanocapillary arrays composed of anodic aluminum oxide …

Computational Modeling Of Functionalized Carbon Nanotubes, Nathaniel Lee Miller

Theses and Dissertations

Ab initio self-consistent field (SCF) molecular orbital calculations were performed employing various basis sets to computationally predict methods to functionalize and solubilize carbon nanotubes. The structure and Restricted Hartree-Fock (RHF) or “total” energies of functionalized nanotubes of various configurations were determined via theoretical calculations. Total energies were used to determine preferences for adsorption on nanotube sur-faces. Various diameter carbon nanotubes (CNTs) were tested to determine where a transition from a non-wrapping to a wrapping approach was found likely to occur as a function of diameter. Further refinements to this method could be used to explore additional interactions as nanotube diameter …