Chemical Engineering Commons^™

Nanoparticle Catalytic Enhancement Of Carbon Dioxide Reforming Of Methane For Hydrogen Production, Nicholas Groden

Doctoral Dissertations

The U.S. produces 5559.6 million metric tons of carbon dioxide annually, of which 21% is produced by industrial processes. Steam reforming, an industrial process that accounts for 95% of all hydrogen production in industry, produces 134.5 million metric tons of carbon dioxide or around 11% of the total carbon dioxide produced by industry. This carbon dioxide is then either emitted or goes through a sequestration process that accounts for 75% of the plant's operational costs. An alternative reaction to steam reforming is dry reforming, which utilizes carbon dioxide rather than emitting it and can be used in conjunction with current …

Effect Of Cross-Section-Change Induced Advective Flow On The Primary Dendrite Array Morphology Of Hypoeutectic Pb-Sb Alloys During Directional Solidification, K. Pandit, S. R. Upadhyay, Surendra N. Tewari

Chemical & Biomedical Engineering Faculty Publications

The morphology and distribution of primary dendrites have been examined in Pb-2.2, 5.8 and 10.8 wt. pct. Sb alloy samples directionally solidified (DSed) in ampoules shaped like an hour-glass to examine the influence of cross-section change induced advective flow on the cellular/dendritic interface. This sample design increases the advective flow of the melt towards the array tips, as the liquid-solid interface enters the neck of the ampoule, and then decreases it as the interface exits the neck. The warm solute-rich melt flowing towards the growth front suppresses the extent of side-branching, decreases the primary dendrite spacing, and increases the primary …

Apparatus, Methods And Systems For Fabricating Thin Nanoporous Membranes, Sankar Nair, Jeffrey H. Drese, Kiwon Eum, Ryan P. Lively, Ali A. Rownaghi, Yash Tamhankar, Shaowei Yang

Chemical and Biochemical Engineering Faculty Research & Creative Works

Embodiments of the present disclosure provide apparatuses, methods and systems for scalable fabrication of thin, nanoporous membranes useful in industrial applications. One embodiment of the present disclosure provides a molecular separation device configured to efficiently separate molecular species. In this particular embodiment, porous hollow fibers form a supporting scaffold for synthesis of a molecular organic framework (MOF) membrane. The MOF membrane may be synthesized on the inner or outer porous hollow fiber surface as well as within the porous fiber wall. Embodiments of the present disclosure provide a variety of methods for producing the aforementioned molecular separation devices as well …

Rate-Determining Step And Active Sites Probing For Platinum-Group-Metal Free Cathode Catalyst In Fuel Cell, Yechuan Chen

Chemical and Biological Engineering ETDs

With the increasing demand on renewable energy, the fuel cell has attracted more and more interests because of its large power density and controllable size. However, the insufficiency of element abundance and unstable expensive price of conventional platinum-based electrocatalysts used in anode and cathode makes it essential to find their substitutes. As one of the most promising candidates to be used in cathode for oxygen reduction reaction (ORR), iron-nitrogen-carbon (Fe-N-C) catalysts have been widely investigated and get commercialized recently, but still lacks comprehensive understanding on the kinetic mechanism.

This dissertation has been divided into three parts with a discussion on …

Micro-Flow Nanocatalysis: Synergic Effect Of Tfoh@Spions And Micro-Flow Technology As An Efficient And Robust Catalytic System For The Synthesis Of Plasticizers, Maryam Tashi, Behnaz Shafiee, Yoshie Sakamaki, Ji-Yun Hu, Zachary Heidrick, Ahmad R. Khosropour, M. Hassan Beyzavi

Chemistry & Biochemistry Faculty Publications and Presentations

The combination of continuous flow technology with immobilizing of only 0.13 mol% of triflic acid (TfOH) on silica-encapsulated superparamagnetic iron oxide nanoparticles (SPIONs) under solvent-free conditions successfully provided a powerful, efficient, and eco-friendly route for the synthesis of plasticizers. The turnover frequency value in micro-flow conditions varied in the range of 948.7 to 7384.6 h−1 compared to 403.8 to 3099 h−1 for in-flask. This technique works efficiently, encouraging future applications of micro-flow nano-catalysis in green chemistry.

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 …

Controlled Nanomorphology Of Hybrid Organic/Inorganic Multi-Component Composites Through Cooperative Non-Covalent Interactions, Lingyao Meng

Shared Knowledge Conference

Hybrid organic–inorganic nanocomposite polymers, with inorganic nanoparticles embedded in organic matrix have emerged as a special category of multifunctional materials. With rational materials design, these hybrids can show the synergistic effect of the properties from both phases. Homogenous dispersion and orderly arrangement of the organic and inorganic components are key in their functionalities. By controlling the interface and corresponding interfacial interactions between the organic and inorganic entities, we have developed a logical approach to form stable and controlled hybrid nanofiber structures. We demonstrate the formation of hybrid polymer/quantum dots (or iron oxide nanoparticles) nanocomposites through non-covalent interactions (hydrogen bonding, ionic …

Avoiding Pitfalls In The Determination Of Reliable Electrochemical Kinetics Parameters For The Cu2+ → Cu1+ Reduction Reaction In Deep Eutectic Solvents, Dai Shen, Katherine Steinberg, Rohan Akolkar

Faculty Scholarship

Deep eutectic solvents (DES), on account of their low-cost, non-flammability and electrochemical stability, are attracting attention for their potential use in applications such as electrodeposition and energy storage. In these applications, knowledge of the transport and electrochemical kinetics properties of DES is critically important. To date, attempts to measure the kinetics parameters of the Cu2+ +e Cu1+ reaction in ethaline DES have yielded a cathodic charge transfer coefficient (α) in the range of 0.2–0.3 suggesting an unexpected asymmetric polarization behavior. In the present work, we pursued a comprehensive study of the kinetics and transport properties of the aforementioned reaction. Using …

Performance Evaluation And Solutions For Port Congestion Focused On The Container Terminal : A Case Study Of Khalifa Bin Salman Port (Kbsp) Kingdom Of Bahrain, Mohamed Ebrahim A.S. Alhameedi, Abud Jamal Said, Tri Wahyunita Mudjiono

World Maritime University Dissertations

No abstract provided.

Enhanced Co2 Conversion By The Simultaneous Doping Of Co, Fe, And Mn In The B-Site Of A Lanthanum Perovskite, Adela E. Ramos

USF Tampa Graduate Theses and Dissertations

There is a pressing need for carbon dioxide (CO₂) mitigation technologies as increasing emissions continue to threaten our environment. Carbon capture and storage (CCS) alone would not be able to achieve temperature rise below 2 °C. In addition, CCS cost increases considerably for power generation and other industries where CO₂ separation is necessary. Conversion of CO₂ to usable products is the most economical and feasible solution as it could offset CO₂ separation cost. Liquid fuels are an attractive route since it is a commodity used globally and demand increases with population and economic growth. Conversion …

Application Of A Light Switchable System In Redirecting Escherichia Coli Metabolic Fluxes, Xintong Xia

Graduate Theses - Chemical Engineering

Optogenetics has gained increasing attention for enabling reversible and non-invasive control in biochemical engineering. The purpose of this project is to investigate the application of a genetically engineered light-switchable system, Cph8-OmpR, for controlling the accumulation of the useful central metabolite glucose-6-phosphate (G6P) in Escherichia coli. This could be accomplished by linking expression of an adaptor protein, SspB, which increases enzyme phosphofructokinase (Pfk) degradation, with different light intensities. Pfk is the enzyme that catalyzes the conversion of fructose-6-phosphate (F6P), an isomer of G6P from an equilibrium reaction, to fructose 1,6-biphosphate for downstream metabolism. This step is considered the major control point …

Scaling Nonreactive Cross Flow Over A Heated Plate To Simulate Forest Fires, Nikolay Gustenyov, Nelson Akafuah, Ahmad Salaimeh, Mark A. Finney, Sara Mcallister, Kozo Saito

Institute of Research for Technology Development Faculty Publications

The paper reports visualization of the flow of smoke over a flat surface inside of a low-speed wind tunnel. A heating plate flush mounted on the wind tunnel floor simulated a spreading line fire that produces uniform heat flux under constant wind speed condition. A paper-thin cloth was soaked with commercially available Vaseline and placed on top of the heating plate; when it is heated, it produced thick white smoke, ideal for flow visualization. Two sides and top of the wind tunnel were made of a trans- parent acrylic sheet that enabled LED and laser sheet light illumination of the …

Air Temperatures Tutorial, Nihad E. Daidzic

Aviation Department Publications

No abstract provided.

A Discrete Element Method Study Of Granular Self-Organization In An Orbital-Driven Sphere And Computational Fluid Dynamics Simulations Of Slurry Flow In A Single-Loop Loop Reactor, Spencer Blum

Honors Capstones

No abstract provided.

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 …

Single Cell Analysis Of Fluid Shear Stress Induced Breast Cancer Cell Phenotypic Changes In A Microfluidic Device, Grant Landwehr

Honors Capstones

No abstract provided.

Sorption Of Benzene, Toluene And Ethylbenzene By Plasticized Poly (Ethyl Methacrylate) Using Quartz Crystal Microbalance At 298.15k, Kiranpreet Kaur

USF Tampa Graduate Theses and Dissertations

Quartz crystal microbalances (QCM) are chemical sensors used for liquid and vapor sensing. In this thesis work, plasticized poly (ethyl methacrylate) (PEMA) coated QCM was used to study sorption behavior of benzene, ethylbenzene and toluene in respective polymer at 298.15K. Poly (ethyl methacrylate) (PEMA) is a promising polymer with solubility parameter close to BTEX compounds, but it's glassy and rigid nature at room temperature make it less sensitive. The addition of plasticizers (Diisononyl cyclohexane-1,2-dicarboxylate (DINCH) and Diisooctyl azelate (DIOA)) lowers the glass transition temperature, provides flexibility and thus increases the free volume of the polymer to enhance analyte sorption. In …

Multicellular Models Bridging Intracellular Signaling And Gene Transcription To Population Dynamics, Mohammad Aminul Islam, Satyaki Roy, Sajal K. Das, Dipak Barua

Computer Science Faculty Research & Creative Works

Cell signaling and gene transcription occur at faster time scales compared to cellular death, division, and evolution. Bridging these multiscale events in a model is computationally challenging. We introduce a framework for the systematic development of multiscale cell population models. Using message passing interface (MPI) parallelism, the framework creates a population model from a single-cell biochemical network model. It launches parallel simulations on a single-cell model and treats each stand-alone parallel process as a cell object. MPI mediates cell-to-cell and cell-to-environment communications in a server-client fashion. In the framework, model-specific higher level rules link the intracellular molecular events to cellular …

Experimental Investigation On Heat Transfer In A Prismatic Modular Reactor Under Cosine Heat Flux, S. M. Alshehri, I. A. Said, Muthanna H. Al-Dahhan, Shoaib Usman

Chemical and Biochemical Engineering Faculty Research & Creative Works

The current study has investigated natural convection heat during pressurized conduction cooldown (PCC) accident scenario to understand the passive safety features of prismatic modular reactors (PMR) under different intensities of nonuniform center peaking step heat flux distributions (approximating cosine shape) using an advanced fast-response heat transfer technique. A scaled-down PMR module was designed and developed at Missouri S&T by the research team of the Multiphase Reactors Engineering and Applications Laboratory (mReal). The module consists of upper and lower plena connected by heated and cooled channels. Nonuniform heat flux distribution was applied to the heated channel under nonuniform heating center peaking …

Establishment And Application Of Fractal Capillary Tube Bundle Model Of Porous Media, Zhonghua Liu, Jianing Shen, Qianhua Xiao, Zhongpei Ding, Shunpeng Zeng, Baojun Bai

Geosciences and Geological and Petroleum Engineering Faculty Research & Creative Works

In view of the problem of statistical regression constant in the model of capillary tube bundles in the porous media, a capillary bundle percolation model with fractal geometry was reconstructed. The function expressions of the fractal coefficient and Kozeny constant were deduced. The relationship between the macroscopic fractal properties of porous media and the fractal dimension and the micro pore parameters were obtained. Results show: Fractal coefficient is a function of fractal dimension, maximum pore radius and minimum pore radius; The macroscopic physical properties of porous media are a function of the fractal dimension and the radius of the capillary …