Engineering Commons^™

Spray-Dried Cellulose Nanofibril-Reinforced Polypropylene Composites For Extrusion-Based Additive Manufacturing, Lu Wang

Electronic Theses and Dissertations

Compared to conventional manufacturing process, additive manufacturing (AM) offers free-form design, lighter and more ergonomic products, short lead time and less waste. Extrusion-based AM can be used to print thermoplastics. However, extrusion-based AM has processing challenges in printing semi-crystalline thermoplastics, for instance, polypropylene (PP). Cellulose nanofibrils (CNF) are one type of cellulose nanofibers that are produced from pulp fibers. CNF has extraordinary properties which make it an ideal candidate to reinforce polymers. Spray-dried CNF (SDCNF) is able to be incorporated into thermoplastic matrices without modifying conventional processing procedures.

The mechanical properties of 3D printed plastic parts have been considered significantly …

Production Of Bio-Oil With Different Oxygen Content And Characterization Of Catalytic Upgrading To Transportation Fuel, Mubarak Mohammed Khlewee

Electronic Theses and Dissertations

The world’s increasing population requires an increase in transportation fuel production. The lack of production of transportation fuels due to the shortage of fossil fuel resources combined with concerns about global emissions of carbon dioxide from fossil fuel combustion are the two major issues that have driven researchers to actively pursue alternative sources for oil production. Biomass is being considered as an alternative feedstock to produce fuel and chemicals due to its abundance and renewability. It has many features that make it suitable as a source of transportation fuel production. However, the bio-oil produced by the fast pyrolysis process has …

Operational Limits Of Blade Coating With High Aspect Ratio Pigments, Lisa Weeks

Electronic Theses and Dissertations

During the blade coating of paper, operational issues such as stalagmite formation, scratches or spits can develop at high solids content and high web speeds. For coatings that contain high aspect ratio pigments, these difficulties appear at lower solids concentrations and slower machine speeds than with more spherical shaped pigments. These operational issues are important because plate shaped particles have good properties in publication and barrier grades. A number of possible mechanisms have been described in the literature, but a clear cause has not been established nor have methods to estimate the operational limits been proposed.

The influence of particle …

Artificial Olfactory System For Multi-Component Analysis Of Gas Mixtures., Alexander Aleksandrovich Larin

Electronic Theses and Dissertations

Gas analysis is an important part of our world and gas sensing technology is becoming more essential for various aspects of our life. A novel approach for gas mixture analysis by using portable gas chromatography in combination with an array of highly integrated and selective metal oxide (MOX) sensors has been studied. We developed a system with small size (7 x 13 x 16 inches), low power consumption (~10 W) and absence of special carrier gases designed for portable field analysis (assuming apriori calibration). Low ppb and even sub-ppb level of detection for some VOCs was achieved during the analysis …

A Comparison Of Mean Age Theory And Residence Time Distributions In Mixed Systems., Nolan Theaker

Electronic Theses and Dissertations

A comparison between mean age theory and conventional residence time distributions over a range of quantified mixing levels was conducted using computational fluid dynamics (CFD). The system was a stirred tubular reactor. The model was validated by comparing computationally derived RTD curves with experimentally obtained RTD curves, with quantified differences less than 3%. Mixing was quantified using the Tanks-in-Series model. Mixing levels were set by varying flow rate and impeller rpm. Mean age distributions at the outlet, where experimental RTD’s were measured, were very narrow for all levels of mixing studied. RTD’s showed expected characteristics; a wider distribution and long …

Characterization Of Catalysts For Hydrodeoxygenation Of Bio-Oils Using Phenol As A Model Compound, Abdulazeez Mohammed Khlewee

Electronic Theses and Dissertations

Due to the environmental considerations, depletion of fossil fuel reserves and fluctuating non-renewable fuel price, converting non-edible lignocellulosic biomass into renewable energy resources has gained significant importance. Phenol has been chosen as a model compound for catalytic screening because it is abundant in bio-oil composition and shows a high resistance to oxygen removal during hydrodeoxygenation (HDO) reactions. HDO of phenol produces chemicals that can be used as transportation fuels (Aromatics) or fuel additives. Theoretically, HDO of phenol has two distinct reduction pathways: direct deoxygenation (DDO) and hydrogenation (HYD). The previous results published by our group showed a precedent activity and …

Creating Renewable Tunable Polymers From Hydroxymethylfurfural, Meredith C. Allen

Electronic Theses and Dissertations

The research here deals with the conversion of 5-hydroxymethylfurfural (HMF) into a tunable polymer. HMF is a known derivative that can be acquired from biomass via hydrolysis of cellulose followed by isomerization and finally selective dehydration. The process considered here is being developed to create tunable polymers from HMF and involves several different steps, three of which are covered here. The first step, an etherification, is the reaction of HMF with an alcohol. This step is significant because in this step the R-group from the alcohol is added to HMF and the branching portion formed is carried over to the …

So2-Alcohol-Water Fractionation Of Sugarcane Straw, Asif Sharazi

Electronic Theses and Dissertations

Climate change resulting from fossil fuels combustion is motivating researchers to explore feasible routes to convert renewable biomass into biofuels and biochemicals for a sustainable society. Typically, biofuel is produced from corn or sugarcane but both feedstocks compete with human food supply. Thus, lignocellulosics as renewable feedstock represent a more ethical and ecofriendly approach. Sugarcane straw (SCS) is a cheap and abundantly available feedstock which potentially can be used for biofuels/biochemicals production. It can also help to mitigate environmental and health problems resulting from conventional practice of SCS burning in the fields.

There are different biomass conversion technologies for production …

Characterization Of Paper Dusting, Gregory K. Yum

Electronic Theses and Dissertations

Dusting of paper in various printing and processing operations is a common problem. The dusting tendency of a paper is difficult to characterize with standard laboratory methods; there is currently no standard test available. As the trend to create grades with high filler content continues, the issue of dusting will remain important. The goal of this thesis was to explore various methods to characterize the dusting and linting in a laboratory environment with limited samples and time.

Techniques to cause and collect dust are compared that include a tape pull test, a bending test, and an abrasion test. Methods to …

Novel Processing Approaches For Thin Film Solar And Related Technologies., Brandon Lavery

Electronic Theses and Dissertations

A growing population along with developing nations are increasing the demand for energy. The International Energy Agency forecasts a global electricity demand increase of 70 percent by 2040. This is an increase from nearly 18 TW to over 30 TW. The sun can be a great clean source of achieving this energy demand. Despite the large solar industry development, the market is still growing as solar energy only accounted for 0.87% of the global energy production in 2013. The opportunity exists to manufacture more affordable solar energy that can penetrate more of the global energy market. In this dissertation, a …

Liquid Gating Ptfe Membranes To Reduce Fouling, Jonathan C. Overton

Electronic Theses and Dissertations

In the processing industry, fouling due to the accumulation of bioparticles or bacteria on the surface of membranes results in decreased capacity, and subsequently requires filtration membranes to require periodic cleaning, causing increased operating costs. In this work, we evaluate the recently discovered concept of liquid-gated membranes (LGMs) in both filtration characteristics, as well as their ability to facilitate passive cleaning of membranes fouled with whey proteins. Additionally, we show that biofilms formed on the surface of these membranes can be removed through exposure to an air-water interface through a simple dipping step. We further analyze the mechanisms of fouling …

Novel Iii-V Alloys For Unassisted Water Splitting., Alejandro Martinez-Garcia

Electronic Theses and Dissertations

Direct conversion of solar energy to fuels by photoelectrochemical (PEC) water splitting has been identified as a promising route for sustainable power generation and storage. However, semiconductor materials with suitable opto-electronic properties have yet to be identified. In this dissertation, band gap engineering of III-V alloys, tuning the light sensitivity of GaP and GaN nitride through alloying Sb, is investigated for developing new semiconductor alloys with appropriate opto-electronic properties and their performance with overall water photoelectrolysis. In addition to III-V materials, copper oxide (Cu₂O) electrode was investigated for p-type semiconductor material. The new III-V alloy anodes were studied …

Effect Of High Cationic Flocculant On Anaerobic Digestion Of Municipal Wastewater., Prathap D. John

Electronic Theses and Dissertations

Anaerobic digestion (AD) of municipal sludge is a widely used stabilization process at municipal wastewater treatment plants. It is highly effective in reducing sludge volume and produces methane gas which is used as fuel in the wastewater plant. Following digestion sludge is sent to a centrifuge to separate the solids from the liquids. Louisville MSD adds flocculent to material in the centrifuge to better coagulate the solids, thereby aiding in separation of the solids from the liquids. The potential for further AD, COD reduction, and methane generation of the liquid effluent from the centrifuge was unknown, particularly in regards to …

Data Driven Discovery Of Materials Properties., Fadoua Khmaissia

Electronic Theses and Dissertations

The high pace of nowadays industrial evolution is creating an urgent need to design new cost efficient materials that can satisfy both current and future demands. However, with the increase of structural and functional complexity of materials, the ability to rationally design new materials with a precise set of properties has become increasingly challenging. This basic observation has triggered the idea of applying machine learning techniques in the field, which was further encouraged by the launch of the Materials Genome Initiative (MGI) by the US government since 2011. In this work, we present a novel approach to apply machine learning …

Towards A Cost-Effective Biorefinery : Production Of Activated Carbons From Residual Biomass For Energy Storage Devices., Zachary Dean Herde

Electronic Theses and Dissertations

Biomass processing for industrial products and biofuels has gained an increasing presence as society looks to using sustainable resources for manufacturing and renewable fuels for energy. However, these sustainably produced materials and products cannot gain a competitive edge because of the manufacturing expenses that are a result of high process temperatures and pressures. In order to lower these costs, theoretical modeling has described a value-added co-product strategy as one of the best ways to combat high bioprocessing prices. Biomass has been shown to make effective carbons for energy storage devices such as supercapacitors and batteries. These carbons, with the right …

Activated Carbon Preparation And Modification For Adsorption, Yuhe Cao

Electronic Theses and Dissertations

Butanol is considered a promising, infrastructure-compatible biofuel. Butanol has a higher energy content than ethanol and can be used in conventional gas engines without modifications. Unfortunately, the fermentation pathway for butanol production is restricted by its toxicity to the microbial strains used in the process. Butanol is toxic to the microbes, and this can slow fermentation rates and reduce butanol yields. Gas stripping technology can efficiently remove butanol from the fermentation broth as it is produced, thereby decreasing its inhibitory effects. Traditional butanol separation heavily depends on the energy intensive distillation method. One of the main issues in acetone-butanol-ethanol fermentation …

Designing And Development Of A Photobioreactor For Optimizing The Growth Of Micro Algae And Studying Its Growth Parameters, Sarmila Katuwal

Electronic Theses and Dissertations

This thesis presents the estimated value of materials required to grow 1g of biomass and the analysis of the light intensity with respect to flow path and flow rate. This thesis aims to design the sparger for a flat plate Photobioreactor, study the flow patterns at different flow rate of air flow and check the performance of flat plate PBR by growing the cyanobacteria. The estimated value to produce 1g of biomass (C_44.6H₇O₂₅N_7.68P_0.9S_0.3) was 0.099g of N, 0.493g of C, 0.160 g of Na, 0.026 g of P, …

A Regional Study Of Wilcox Reservoirs In The Deepwater Northern Gulf Of Mexico, Margaret Elizabeth Dice

Electronic Theses and Dissertations

The Deepwater Wilcox trend covers more than 34,000 mi2, extending from the northwestern block, Alaminos Canyon, to Keathley Canyon, and to the north-central block, Walker Ridge. The Wilcox trend is widely studied in the oil and gas industry as it has significant proven hydrocarbons, but has considerable economic challenges due to the reservoir characteristics. The purpose of this study is to provide a regional study of the Wilcox reservoir economics and quality. Great white field is the most successful Wilcox field located in the northwestern Gulf of Mexico and Jack and St. Malo are the most successful Wilcox fields located …

Biphasic Cellulose Acetate/Rtil Membranes And Functionalized Graphene Adsorbents For Natural Gas Processing: Experimental And Molecular Simulation Studies, Amir Khakpay

Electronic Theses and Dissertations

In this dissertation, gas separation using membranes is investigated for natural gas upgrading. The main objectives of this study are separation of high value hydrocarbons such as propane (c3h8) from natural gas and carbon dioxide (co2) separation from light gases such as nitrogen (n2) and methane (ch4). To achieve these goals, supported ionic liquid membranes (silms), biphasic membranes, and nanoporous graphene (npg) and graphene oxide (npgo) membranes are studied. Biphasic membranes are proposed to overcome silms issues for gas separation. The major issues with silms are low room temperature ionic liquid (rtil) content and instability at high cross-membrane pressure. For …

Green Thermosetting Factory: Novel Star-Shaped Bio-Based Systems And Their Thermosetting Resins; Synthesis And Characterization, Arash Jahandideh

Electronic Theses and Dissertations

Increasing attentions toward sustainable development, economic and environmental issues have led to many attempts at replacing the petroleum-based materials with renewables. Substitution of petroleum-based platforms with green alternative technologies is beneficiary in different ways. Using bio-renewables reduces the dependency of the national plastic industry to the petroleum resources and substantially promotes the environmental profile and sustainability of the product. It is expected that the emergence of the corn-based thermosetting industry generates substantial profits for the corn production sector. Developments in the emerging biobased thermosets are spectacular from a technological point of view. However, there are still several disadvantages associated with …

Advanced Carbon Materials Based Electrodes For High Performance Symmetric Supercapacitors, Keliang Wang

Electronic Theses and Dissertations

Supercapacitors have received considerable attention due to their high energy density, long life time, rapid charge/discharge rate, and because they are environmental friendly technology. Electrode materials play a key role in the final performance of supercapacitors. Carbon, usually used as symmetric supercapacitors electrode materials, exhibit extraordinary stability in harsh electrolyte and electrochemical performance owing to its physical and chemical properties. In addition, porous structure originated from activation, excellent electrical conductivity, sustainability, wide availability and low cost further offering the improvement in electrochemical performance and make it to be a promising electrode material for symmetric supercapacitors. Considering the factors affected electrochemical …