Engineering Commons^™

Production Of Ethanol From Cereal Food Fines Using Dilute-Acid Hydrolysis, Andrew Edward Arnett

Graduate Theses and Dissertations

Cereal food fines are a leftover by-product from breakfast cereal processing that is typically sold as animal feed or used as a pet food ingredient; however this product could be of greater value as a feedstock for the production of fuel ethanol via fermentation. In order for this material to be fermented it has to be broken down in to simple sugars using hydrolysis. One method of hydrolysis is called dilute-acid hydrolysis, whereby low concentrations of acid are added to the feedstock to facilitate the breaking of chemical bonds. This study investigates the effect of different concentrations of acid to …

Eicosapentaenoic Acid (Epa) From Porphyridium Cruentum: Increasing Growth And Productivity Of The Microalgae For Pharmaceutical Products, Maryam Asgharpour

Graduate Theses and Dissertations

One of the major nutritional requirements in our diet is an adequate intake of omega-3 specially eicosapentaenoic acid (EPA). In the present study, the effects of two temperatures (16°C & 20˚C) and light intensities (140 & 180µE/M2.S) and four nitrate levels (0.075, 0.3, 0.5 and 0.7g/L) on the cell growth and lipid productivity of Porphyridium cruentum, one of the most promising oil-rich species of microalgae, were investigated. A growth comparison was carried out using pure CO2 and 5% CO2/air. Additionally, the ratio of the fatty acids with omega-3 and omega-6 groups at various growth conditions were compared, since an appropriate …

Modeling Of Gas Production From Shale Reservoirs Considering Multiple Transport Mechanisms, Chaohua Guo, Mingzhen Wei, Hong Liu

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Gas transport in unconventional shale strata is a multi-mechanism-coupling process that is different from the process observed in conventional reservoirs. In micro fractures which are inborn or induced by hydraulic stimulation, viscous flow dominates. And gas surface diffusion and gas desorption should be further considered in organic nano pores. Also, the Klinkenberg effect should be considered when dealing with the gas transport problem. In addition, following two factors can play significant roles under certain circumstances but have not received enough attention in previous models. During pressure depletion, gas viscosity will change with Knudsen number; and pore radius will increase when …

Hybrid Aryl-Ether-Ketone And Hyperbranched Epoxy Networks, John Misasi

Dissertations

In this dissertation, relationships between chemical structures, cure kinetics and network architectures are correlated to bulk mechanical properties for novel, hybrid epoxy-amine networks. The work is split into two primary sections: the first is the synthesis and characterization of multifunctional glassy networks based on aryl-ether-ketone diamine curatives, while the second is based on the synthesis and characterization of hyperbranched epoxy polymers and their resulting networks.

Three aryl-ether-ketone (AEK) diamines of increasing molecular weights were synthesized and used to cure 4,4’-tetraglycidylether of diaminodiphenylmethane (TGDDM); the resulting networks were compared to 4,4’-diaminodiphenyl sulfone cured TGDDM. Architectural differences were created by varying cure …

Size-Controlled Large-Diameter And Few-Walled Carbon Nanotube Catalysts For Oxygen Reduction, Xianliang Wang, Qing Li, Hengyu Pan, Ye Lin, Yujie Ke, Haiyang Sheng, Mark T. Swihart, Gang Wu

Faculty Publications

We demonstrate a new strategy for tuning the size of large-diameter and few-walled nitrogen-doped carbon nanotubes (N-CNTs) from 50 to 150 nm by varying the transition metal (TM = Fe, Co, Ni or Mn) used to catalyze graphitization of dicyandiamide. Fe yielded the largest tubes, followed by Co and Ni, while Mn produced a clot-like carbon morphology. We show that morphology is correlated with electrocatalytic activity for the oxygen reduction reaction (ORR). A clear trend of Fe > Co > Ni > Mn for the ORR catalytic activity was observed, in both alkaline media and more demanding acidic media. The Fe-derived N-CNTs exhibited …

Overview Of Estimation Methods For Industrial Dynamic Systems, John Hedengren, Ammon Eaton

Faculty Publications

Measurement technology is advancing in the oil and gas industry. Factors such as wireless transmitters, reduced cost of measurement technology, and increased regulations that require active monitoring tend to increase the number of available measurements. There is a clear opportunity to distill the recent flood of measurements into relevant and actionable information. Common methods to do this include a filtered bias update, implicit dynamic feedback, Kalman filtering, and moving horizon estimation. The purpose of these techniques is to validate measurements and align imperfect mathematical models to the actual process. Additionally, they can determine a best-estimate of the current state of …

Chemical Processing Cell With Nanostructured Membranes, Dibakar Bhattacharyya, Scott R. Lewis, Saurav Datta

Chemical and Materials Engineering Faculty Patents

A chemical processing cell includes an upstream membrane and a downstream membrane. The upstream membrane generates a first reaction product. The downstream membrane converts the first reaction product to a second reaction product.

Feasibility Of Cathodic Protection In Grouted Post Tensioned Tendons - Exploratory Model Calculations, Jacob Dharma Bumgardner

USF Tampa Graduate Theses and Dissertations

Recent corrosion related failures of grouted post tensioned tendons, even after the introduction of improved grouts, have led to renewed interest in supplemental or backup means of corrosion control for these systems. A finite element model is presented to explore feasibility of impressed current cathodic protection of strand in grouted tendons. The model examines polarization evolution as function of service time and includes consideration of anode placement and size, grout porosity, pore water alkalinity, electrochemical species diffusivity and applied voltage on the polarization efficacy and durability of such a system. The exploratory model projections suggested that, within the context of …

Prediction And Validation Of External Cooling Loop Cryogenic Carbon Capture (Ccc-Ecl) For Full-Scale Coal-Fired Power Plant Retrofit, Mark J. Jensen, Christopher S. Russell, David Bergerson, Christopher D. Hoeger, David J. Frankman, Christopher S. Bence, Larry Lin Baxter

Faculty Publications

Bench-scale experiments and Aspen Plus (TM) simulations document full-scale, steady-state performance of the external cooling loop cryogenic carbon capture (CCC-ECL) process for a 550 MWe coal-fired power plant. The baseline CCC-ECL process achieves 90% CO2 capture, and has the potential to capture 99+ % of CO2, SO2, PM, NO2, Hg, and most other noxious species. The CCC-ECL process cools power plant flue gas to 175 K, at which point solid CO2 particles desublimate as the flue gas further cools to 154K. Desublimating flue gas cools in a staged column in direct contact with a cryogenic liquid and produces a CO2-lean …

Experimental Study And Numerical Simulation Of Hydraulic Fracturing Tight Sandstone Reservoirs, Chaohua Guo, Jianchun Xu, Mingzhen Wei, Ruizhong Jiang

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

Unconventional tight sandstone reservoirs have been developed during recent years and a large number of multi-stages fractured horizontal wells have been drilled to stimulate reservoir performance. However, fluid flow in low permeability porous media no longer obeys Darcy's law and instead conforms to low-velocity non-Darcy flow. Most commercial numerical simulation software for multi-stage fractured horizontal well development may cause inaccuracy in simulating performance of tight sandstone reservoirs. In this paper, the investigation of existing conditions of low velocity non-Darcy flow for oil flow in irreducible water saturation tight sandstone cores was conducted and discussed through lab-experiments. And existence of low …

Preparations And Properties Of Polybenzimidazole/Polyvinylbenzyl Crosslinked Composite Membranes For High Temperature Proton Exchange Membrane Fuel Cells, Jin-Kai Hao, Yong-Yi Jiang, Zhen Wang, Xiao-Jin Li, Zhi-Gang Shao, Bao-Lian Yi

Journal of Electrochemistry

In order to increase the chemical stability of polybenzimidazole (PBl) membrane, a highly stable polymer, poly vinyl. benzyl chloride (PVBC), was chosen as the macromolecular crosslinker, and 1H-1,2,4-triazol was adopted to prepare the crosslinked PBI-based membranes. The influence of the PVBC amount on membrane characteristic was investigated in detail. The results indi. cated that the crosslinked structure of the membrane effectively improved the chemical stability, and at the same time, the mem. brane presented good mechanical property and proton conductivity. The fuel cell performance for the membrane was tested with hy. drogen and oxygen single cell without humidification at 150 …

Lignin-Derived Thermosetting Vinyl Ester Resins For High Performance Applications, Daniel Rogers

Theses and Dissertations

Vinyl ester (VE) resins are utilized to produce polymer matrix composites for use in a wide range of applications due to possessing relatively high moduli, strengths, and glass transition temperatures while maintaining low weight and cost. VE resins often contain high concentrations of a petroleum-based reactive diluent (RD), such as styrene. Many of the commonly used RDs have been designated as hazardous air pollutants, potential carcinogens, and volatile organic compounds. Renewable VE resins and RDs with similar performance to petroleum-based RDs are desired to potentially mitigate the aforementioned hazards as well as to facilitate the transition from petrochemical feedstocks to …

Electrode Kinetics Of Vanadium Flow Batteries: Contrasting Responses Of VIi-VIii And VIv-VV To Electrochemical Pretreatment Of Carbon, A. Bourke, M. A. Miller, R. P. Lynch, Xin Gao, James Landon, J. S. Wainright, R. F. Savinell, D. N. Buckley

Center for Applied Energy Research Faculty and Staff Publications

Electrochemical impedance spectroscopy and cyclic voltammetry were used to investigate the electrode kinetics of V^II-V^III and V^IV-V^V in H₂SO₄ on glassy carbon, carbon paper, carbon xerogel, and carbon fibers. It was shown that, for all carbon materials investigated, the kinetics of V^II-V^III is enhanced by anodic, and inhibited by cathodic, treatment of the electrode; in contrast, the kinetics of V^IV-V^V is inhibited by anodic, and enhanced by cathodic, treatment. The potential region for each of these effects varied only slightly with carbon material. Rate constants …

High Temperature Proton Exchange Membranes With Enhanced Proton Conductivities At Low Humidity And High Temperature Based On Polymer Blends And Block Copolymers Of Poly(1,3-Cyclohexadiene) And Poly(Ethylene Glycol), Shawn Deng, Mohammad K. Hassan, Amol Nalawade, Kelly A. Perry, Karren L. More, Kenneth A. Mauritz, Marshall T. Mcdonnell, David J. Keffer, Jimmy W. Mays

Faculty Publications

Hot (at 120 °C) and dry (20% relative humidity) operating conditions benefit fuel cell designs based on proton exchange membranes (PEMs) and hydrogen due to simplified system design and increasing tolerance to fuel impurities. Presented are preparation, partial characterization, and multi-scale modeling of such PEMs based on cross-linked, sulfonated poly(1,3-cyclohexadiene) (xsPCHD) blends and block copolymers with poly(ethylene glycol) (PEG). These low cost materials have proton conductivities 18 times that of current industry standard Nafion at hot, dry operating conditions. Among the membranes studied, the blend xsPCHD-PEG PEM displayed the highest proton conductivity, which exhibits a morphology with higher connectivity of …

Application Of A Coated Film Catalyst Layer Model To A High Temperature Polymer Electrolyte Membrane Fuel Cell With Low Catalyst Loading Produced By Reactive Spray Deposition Technology, Timothy D. Myles, Siwon Kim, Radenka Maric, William E. Mustain

Faculty Publications

In this study, a semi-empirical model is presented that correlates to previously obtained experimental overpotential data for a high temperature polymer electrolyte membrane fuel cell (HT-PEMFC). The goal is to reinforce the understanding of the performance of the cell from a modeling perspective. The HT-PEMFC membrane electrode assemblies (MEAs) were constructed utilizing an 85 wt. % phosphoric acid doped Advent TPS® membranes for the electrolyte and gas diffusion electrodes (GDEs) manufactured by Reactive Spray Deposition Technology (RSDT). MEAs with varying ratios of PTFE binder to carbon support material (I/C ratio) were manufactured and their performance at various operating temperatures was …

Highly Selective Hydrogenation And Hydrogenolysis Using A Copper-Doped Porous Metal Oxide Catalyst, Laurene Petitjean, Raphael Gagne, Evan Beach, Dequan Xiao, Paul Anastas

Chemistry and Chemical Engineering Faculty Publications

A copper-doped porous metal oxide catalyst in combination with hydrogen shows selective and quantitative hydrogenolysis of benzyl ketones and aldehydes, and hydrogenation of alkenes. The approach provides an alternative to noble-metal catalysed reductions and stoichiometric Wolff-Kishner and Clemmensen methods.

Ash Formation And Deposition During Oxy-Coal Combustion In A 100 Kw Laboratory Combustor With Various Flue Gas Recycle Options, Zhonghua Zhan, Andrew R. Fry, Danxi Yu, Minghou Xu, Jost O.L. Wendt

Faculty Publications

Fouling and slagging processes are important in oxy-coal combustion processes because they greatly influence heat transfer and boiler performance. Ash partitioning processes are precursors to deposition processes and so in order to predict the latter one must have a good understanding of the former. This work involves a 100 kW rated down-fired oxy-fuel combustor outfitted with sophisticated ash aerosol and ash deposit sampling equipment. The work differs from that previously published, in that here we focus on the effects of changes in the composition and amounts of actual recycled flue gas (RFG) streams used in oxy-coal combustion, not using once …

Investigating The Feasibility Of Nitrogen Injection In Turner Valley, Igor Koracin

Graduate Theses & Non-Theses

The Turner Valley gas and oil field was discovered in 1913 and it was one of the main plays that sparked the growth of the petroleum industry in Canada. The Turner Valley formation is a Mississippian reservoir located at a mean depth of 7,546 feet. It is a heavily faulted field, 25 miles in length with an average width of 2 miles and is located 30 miles south-west of Calgary. It is an asymmetric anticlinal structure cut by the y axis with parallel thrust and normal faults.

Due to its early inception and the lack of resource development regulations, Turner …

Modifying Fracture Conductivity Testing Procedures, Kent Blair

Graduate Theses & Non-Theses

Fracture conductivity testing is a measure of how proppant will perform downhole when injected. The current American Petroleum Institute (API) procedure for conductivity testing produces results that are difficult to replicate. In one case three commercial labs tested the same sample of proppant, the results varied between labs and the highest spread in data had an 80% variation (Anderson, 2013). The goal of this thesis is to investigate cell loading procedures that reduce the variation in laboratory results.

A variety of cell loading techniques were tested including Hoke cylinder injection, guar injection, and cell vibration. Hoke cylinder loading was determined …

Influence Of Carbon Nanofillers On The Curing Kinetics Of Epoxy-Amine Resin, Luigi Vertuccio, Salvatore Russo, Marialuigia Raimondo, Khalid Lafdi, Liberata Guadagno

Chemical and Materials Engineering Faculty Publications

The cure kinetics of an epoxy resin based on the tetrafunctional epoxy precursor N,N′-tetraglycidyl methylene dianiline-(TGMDA) hardened with 4,4-diaminodiphenyl sulfone is investigated. The influence of carbon nanofillers (carbon nanotubes, carbon nanofibers, and graphene based nanoparticles) on the cure kinetic is studied. Kinetic analysis is performed by dynamic and isothermal differential scanning calorimetry (DSC).

In dynamic experiments, the activation energy was computed using an advanced isoconversional method while under isothermal conditions, the Kamal’s model of diffusion control was applied to simulate the systems throughout the curing process. The isothermal analysis shows that the introduction of the diluent decreases, …

Gasification Of Coal And Heat Integration Modification For Igcc - Integrated Gasification Combined Cycle, Dalia A. Ali Eng, Mamdouh A. Gadalla Prof., Fatma H. Ashour Prof.

Chemical Engineering

Use of energy is closely related to the development of an economy. The most useful form of energy in the modern world is electricity. IGCC has higher fuel flexibility (biomass, refinery residues, petroleum coke, etc.) and generates multiple products (electricity, hydrogen and chemicals like methanol and higher alcohols) and by-products - sulphur, sulphuric acid, slag, etc. IGCC plants include coal preparation unit, air separation unit (ASU) to separate oxygen from air to use it in the gasification process, gasification unit where an incomplete combustion for coal is made to produce Syngas, cleaning unit to remove acid gases and CO2 from …

Synthesis, Characterisation, Electrochemical, And Spectroscopic Studies Of Cobaloximes: Unique Clues Of Cobalt(I) Species In Various Solvents, Michael John Celestine

Chemistry & Biochemistry Theses & Dissertations

With the dwindling amount of fossil fuels in the world’s reserve is said to run out in the future. The use of alternative fuels such as hydrogen can be produced from renewable sources. One source is the use of first row transition metal complexes that can harness the power of the sun to reduce protons to hydrogen. In this thesis we investigated a well-known hydrogen evolution catalyst in a quest to understand the behavior of different oxidation states that occur during the catalytic cycle.

In an attempt to synthesize a binuclear ruthenium(II) complex, [{Ru(phen)2}2{µmes(1,4-phO-Izphen)3}](PF6)4, as a possible photosensitizer for the …

Conference Program And Abstracts, Nicolas Abatzoglou, Sascha Kersten, Dietrich Meier

Biorefinery I: Chemicals and Materials From Thermo-Chemical Biomass Conversion and Related Processes

No abstract provided.

A Framework For An Economic Model Of Novel Process For The Fractionation Of Dried Distillers Grain With Solubles, R. Zakrzewski, K. Gounaropoulos, R. Allmendinger, M. Villegas Torres, C. Ibenegbu, R. Roque, S. Farid, J. Ward, G. Lye

Biorefinery I: Chemicals and Materials From Thermo-Chemical Biomass Conversion and Related Processes

No abstract provided.

Elevated Test Pressure Significantly Reduces Dynamic Accumulation Oxygen Transmission Rate (Astm F3136) Measurement Time For Barrier Packaging Films, Bruce A. Welt

Journal of Applied Packaging Research

Measurement of gas transmission rates of materials is important for successful package design. The dynamic accumulation (DA) method (ASTM F3136) is becoming increasingly popular for measuring oxygen transmission rate (OTR) due to its simplicity and low cost. However, measurement time increases with barrier properties of materials, limiting measurement throughput. A dynamic accumulation measurement prototype capable of operating up to 1,000 psig was developed in order to accelerate gas transfer by boosting concentration gradients via elevated absolute pressures. Results show that measurement results were independent of test pressure while measurement times were substantially reduced. These results also suggest that gas transmission …

Hybrid Dynamic Optimization Methods For Systems Biology With Efficient Sensitivities, Nicholas Lewis, John Hedengren, Eric Haseltine

Faculty Publications

In recent years, model optimization in the field of computational biology has become a prominent area for development of pharmaceutical drugs. The increased amount of experimental data leads to the increase in complexity of proposed models. With increased complexity comes a necessity for computational algorithms that are able to handle the large datasets that are used to fit model parameters. In this study the ability of simultaneous, hybrid simultaneous, and sequential algorithms are tested on two models representative of computational systems biology. The first case models the cells affected by a virus in a population and serves as a benchmark …

Structural And Functional Characterization Of A Lytic Polysaccharide Monooxygenase With Broad Substrate Specificity, Anna S. Borisova, Trine Isaksen, Maria Dimarogona, Abhishek A. Kognole, Geir Mathiesen, Anikó Várnai, Åsmund K. Røhr, Christina M. Payne, Morten Sørlie, Mats Sandgren, Vincent G. H. Eijsink

Chemical and Materials Engineering Faculty Publications

The recently discovered lytic polysaccharide monooxygenases (LPMOs) carry out oxidative cleavage of polysaccharides and are of major importance for efficient processing of biomass. NcLPMO9C from Neurospora crassa acts both on cellulose and on non-cellulose β-glucans, including cellodextrins and xyloglucan. The crystal structure of the catalytic domain of NcLPMO9C revealed an extended, highly polar substrate-binding surface well suited to interact with a variety of sugar substrates. The ability of NcLPMO9C to act on soluble substrates was exploited to study enzyme-substrate interactions. EPR studies demonstrated that the Cu²⁺ center environment is altered upon substrate binding, whereas isothermal titration …

Interplays Of Co2, Subnanometer Metal Clusters, And Tio2: Implications For Catalysis And Co2 Photoreduction, Chi-Ta Yang

USF Tampa Graduate Theses and Dissertations

This research is motivated by two significant challenges facing the planet: reducing the emission of CO₂ to the atmosphere and production of sustainable fuels by harnessing solar energy. The main objective of this work is the study of promising photocatalysts for CO₂ reduction. DFT modeling of CO₂, subnanometer Ag&Pt clusters, and anatase TiO2 (101) surface is employed to gain fundamental understanding of the catalytic process, followed by validation using a guided experimental endeavor. The binding mechanism of CO₂ on the surface is investigated in detail to gain insights into the catalytic activity and to assist …

An Investigation On The Band Gap And Band Edge Of Semi-Conducting Lanthanum Transition Metal Perovskites For Photocatalytic Applications, Divya Suresh

USF Tampa Graduate Theses and Dissertations

For the past few decades, a frenzy of attention has been given towards the development of an assortment of photocatalysts as a solution for various environmental problems. TiO2 is the most widely used photocatalyst. TiO2 is biocompatible, chemically and thermally stable but TiO2 and a vast majority other photocatalysts have large band gaps, and hence they find applicability only in the UV region of the solar spectrum. These large band gap photocatalysts suffer a severe limitation with regard to their overall process efficiency as the UV region contributes to about 3 to 4 % of the solar spectrum in terms …

Applications Of Optical Properties From Nanomaterials For Enhanced Activity Of A Titania Photocatalyst Under Solar Radiation, Jon W. Pickering

USF Tampa Graduate Theses and Dissertations

In recent years, employing advanced oxidation processes (AOPs) as a means of wastewater remediation has emerged as a promising route towards maintaining a sustainable global water management program. The heterogeneous photocatalytic oxidation process has been of particular interest due to the prospective of utilizing solar radiation as the driving force behind the degradation of pollutants. Of the photocatalyst studied to date, TiO2 remains the most attractive material for environmental applications due to its affordability, stability, biocompatibility and high quantum yield. A key draw back however is roughly only 5% of solar radiation incident on earth can provide the energy required …