Catalysis and Reaction Engineering Commons^™

Chromatographic Dynamic Chemisorption, Shreya Thakkar

Masters Theses

Reaction rates of catalytic cycles over supported metal catalysts are normalized by the exposed metal atoms on the catalyst surface, reported as site time yields which provide a rigorous standard to compare distinct metal surfaces. Defined as the fraction of exposed metal surface atoms to the total number of metal atoms, it is important to measure the dispersion of supported metal catalysts to report standardized rates for kinetic investigations. Multiple characterization techniques such as electron microscopy, spectroscopy and chemisorption are exploited for catalyst dispersion measurements. While effective, electron microscopy and spectroscopy are not readily accessible due to cost and maintenance ...

Photocatalytic Degradation Of Organic Contaminants By Titania Particles Produced By Flame Spray Pyrolysis, Noah Babik

Theses and Dissertations

Advanced oxidation of organic pollutants with TiO2 photocatalysts is limited due to the wide bandgap of TiO2, 3.2 eV, which requires ultraviolet (UV) radiation. When nanosized TiO2 is modified by carbon doping, charge recombination is inhibited and the bandgap is narrowed, allowing for efficient photodegradation under visible light. Here, we propose a flame spray pyrolysis (FSP) technique to create TiO2. The facile process of FSP has been successful in preparing highly crystalline TiO2 nanoparticles. Using the same procedure to deposit TiO2 onto biochar, the photocatalyst was doped by the carbonaceous material. The morphology, crystalline and electronic structure of the ...

Optimization Of Styrene From Ethylbenzene Case Study, Jabria Daria Thompson

Honors Theses

The following pages detail the optimization process of styrene from ethylbenzene in the Styrene Production Plant, Unit 500. There were two parts of the assignment, each with slightly different end goals. The goal of the first part of the assignment, was to create a process that would effectively and efficiently increase the negative Net Present Value (NPV) of the production plant. Procedures taken in this process included developing a working kinetic process simulation model and optimizing this model through unit operations and heat integration, as well as developing an accurate economic model that will be used to evaluate the proposed ...

Optimization Of A Fluidized Bed Reactor For The Production Of Styrene From Ethylbenzene, Gregory Espenan

Honors Theses

In order to optimize Unit 500, a styrene production plant, the Net Present Value (NPV) was used as the objective function to ensure every optimization strategy had a positive economic effect. To optimize a chemical plant, it is important to note efficiency, economics, product specifications, and production requirements. The goal of this project was to make changes to the base case of Unit 500 to minimize the cost to produce styrene for an upstream unit. PRO/II was used to simulate various points in different unit operations throughout the process. The NPV was measured after each unit operation was simulated ...

Analyzing The Surface Chemistry Of Ni-Fe Hydroxide Alloy Nanoparticles As Catalysts For The Oxygen Evolution Reaction By X-Ray Photoelectron Spectroscopy Analysis, Lauren B. Shepard

Chemical Engineering Undergraduate Honors Theses

Water electrolysis has been proposed as a renewable source of hydrogen, a possible replacement to harmful fossil fuels. This process can be broken down into two half reactions, the hydrogen evolution reaction and the oxygen evolution reaction. Because the oxygen evolution reaction has slow kinetics and a high overpotential to overcome, a catalyst is needed to speed up the kinetics and ensure faster and more efficient production of molecular hydrogen. The use of Ni-Fe hydroxide alloy nanoparticles as a catalyst has been shown to significantly improve the efficiency of the reaction by decreasing the overpotential, making the process more energy ...

Catalytic Ring Opening Of Mono- And Bicyclic Compounds For The Production Of Renewable Diesel And Jet Fuel, Matthew J. Kline

Electronic Theses and Dissertations

Thermal DeOxygenation (TDO) is a process that converts organic acids produced from cellulose hydrolysis and dehydration into a low-oxygen bio-oil containing substituted naphthene compounds. The high aromatic content is desirable for gasoline fractions, but middle distillates such as diesel and jet fuel require upgrading via hydrogenation and ring opening to achieve better combustion characteristics. Previous research has demonstrated that TDO oil could be hydrogenated over high-surface-area nickel catalysts to improve the combustion characteristics, but the cetane number was still below the specifications.

Multiple supported catalysts were synthesized by ion exchange and incipient wetness impregnation, and the catalysts were characterized by ...

Electrode Development Of Water Electrolyzer Cells For Low-Cost And High-Efficiency Hydrogen Production, Shule Yu

Doctoral Dissertations

A worldwide increase in energy demand and a latent crisis in the fossil fuel supply have spurred broad research in the renewable energy. Currently, most renewable energy resources (e.g., hydro, wind, solar, tide) face supply challenges as they are known to be intermittent, unstable, and locally shackled, which calls for urgent development in energy storage and conversion. Hydrogen is regarded as an ideal energy carrier with its advantages (e.g., high energy density, environmentally friendliness, and low weight). In practice, the proton exchange membrane electrolyzer cell (PEMEC) is considered to be one of the optimal hydrogen production and energy ...

Computational Rational Design Of Electrocatalysts For Electrochemical Ammonia And Hydrogen Synthesis, Akash Jain

Doctoral Dissertations

The electrochemical hydrogen evolution reaction (HER) and nitrogen reduction reaction (NRR) offer fossil-fuel-free routes for hydrogen and ammonia synthesis, respectively. However, currently, both processes lack suitable electrocatalysts for practical applications. Thus, this dissertation focuses on the computational rational design of HER and NRR electrocatalysts.

HER is most efficiently catalyzed by platinum (Pt), which is expensive. To reduce the catalyst cost, we investigate core-shell nanoparticles of inexpensive tungsten-carbide (WC) and Pt (WC@Pt). Using first-principles density functional theory (DFT) calculations, we compare the suitability of two WC phases, α-WC and β-WC as support materials for Pt overlayers. We dope WC with ...

Design And Fabrication Of Nanostructured Electrodes For Complementary Electrochemical And Photoelectrochemical Water Splitting, Kholoud El Sayed Abousalem

Theses and Dissertations

Designing highly active, durable, and nonprecious electrodes for overall water splitting is of urgent scientific importance to realize sustainable hydrogen production. Accordingly, the need to search efficient energy production systems is of crucial necessity. In this thesis, two various systems for sustainable hydrogen production have been reported using electrochemical and photoelectrochemical pathways. In the first part of the thesis, electrochemical water splitting involving both hydrogen evolution reaction (HER) and oxygen evolution reaction (OER) has been established. To this end, an innovative approach is demonstrated to synthesize flower-like 3D homogenous trimetallic Mn, Ni, Co phosphide catalysts directly on nickel foam via ...

Ethane Dehydrogenation For Light Olefins Production Over Stable Catalyst, Xiaoyan Wang

Graduate Theses, Dissertations, and Problem Reports

Accompanied by the development of modern industry, the demand for light olefins (e.g., ethylene, propylene, butene, butadiene) increases year by year. Light olefins are important intermediates in producing polymers (Polyethylene, Polypropylene, etc.) and rubber (Styrene Butadiene Rubber, Polybutadiene rubber, etc.). The primary process for the production of light olefins is steam cracking of petroleum liquids (naphtha and distillate fuel oil). It is an energy-intensive process, requiring high temperature (750-850℃) and pressure (1.0-4.5 MPa). Meanwhile, due to undesired side reactions, this process has lowered the efficiency of light olefins production and suffers from severe coking issues. Furthermore, as ...

Scale-Up Of Flow-Electrode Capacitive Deionization Method For Hard Water Softening, Noah Henry

Williams Honors College, Honors Research Projects

This study’s purpose is to further document a capacitive deionization design that could be capable of purifying H₂O at a household scale where clean water is otherwise unobtainable in applicable regions of the world. The hypothesis behind this study was continuously larger scaled electrochemical cell-units would increase their water softening capabilities in sustainable fashion. The trend at which performance will scale is currently unknown. The units studied were constructed using graphite plates, anion exchange membranes, cation exchange membranes, and Teflon channels. Three streams, two being CaCl₂ solutions in DI H₂O (one being concentrated with ...

A Competent Mwcnt-Grafted Mnox/Pt Nanoanode For The Direct Formic Acid Fuel Cells, Islam M. Al-Akraa, Moutaz M. Mamdouh, Yaser M. Asal, Ahmad M. Mohammad

Chemical Engineering

No abstract provided.

Effect Of Palladium Loading On Catalytic Properties Of Pd/Gce For The Electro-Oxidation Of Methanol, Formic Acid, And Ethylene Glycol, Islam M. Al-Akraa

Chemical Engineering

No abstract provided.

Catalytic Light Alkanes Selective Conversion Through Ammonia-Assisted Reforming, Siavash Fadaeerayeni

Theses and Dissertations

The fact that hydrogen is a clean and versatile fuel offers an attractive carbon-free source of energy and leverages the U.S. economy toward long-term sustainable economic growth. At an industrial scale, hydrogen production is mostly relying on methane steam reforming producing stoichiometric amounts of carbon oxides (CO and CO2), which imposes economic and environmental concerns. To mitigate the issue, we propose NH3 assisted anaerobic reforming of natural gas liquids (ethane and propane) as an alternative approach to produce COx free hydrogen. Here, in the first chapter, through comprehensive performance evaluation, characterization, and transient kinetic studies, it is shown that ...

Techno-Economics And Life Cycle Analysis Of Upgrading Woody Biomass To Diesel Blendstock, Aysan Najd Mazhar

Electronic Theses and Dissertations

Woody biomass conversion to transportation fuels have been developed as alternatives to fossil fuel production to reduce greenhouse gas emissions and to increase energy security. Fast pyrolysis, a thermochemical technology, has the potential to offer high efficiencies to produce liquid transportation fuels from woody biomass. Fast pyrolysis involves rapid heating of biomass particles in the absence of air at approximately 500°C and results in non-condensable gases, bio-oil (pyrolysis oil), and char as products. The pyrolysis oil can be upgraded via integrated mild hydrogenation and etherification processes to a high energy density fuel that can be blended with diesel for ...

Effect Of Phase Composition Of Tungsten Carbide On Its Catalytic Activity For Toluene Hydrogenation, Aditya Rane

Masters Theses

Commercially important hydrogenation reactions make use of precious noble metal catalysts which are becoming increasingly scarce, and the search for capable alternative catalysts prevails. Transition metal carbides of group IV-VI metals show similar catalytic behavior to platinum and are $103/kg lower in price than the precious metal catalysts. Tungsten carbide, studied in this work, can form in different stoichiometries and phase compositions depending upon synthesis methods. Synthesis of high surface area tungsten carbide with control over its phase composition remains a challenge currently. In this work, the novel isothermal synthesis method of tungsten carbide (WC, W2C) in a CH4 ...

Study Level Recovery Processes Of Thorium And Several Rare Earth Elements From Monazite Ore, Makayla Hyde, Jaclyn Choate

EURēCA: Exhibition of Undergraduate Research and Creative Achievement

Monazite ore is composed of several minerals including several rare earth element (REE) and thorium phosphates. Many past research projects have looked at the extraction of REE from monazite ore but have discarded the thorium phosphate compound as waste. Since thorium could be a possible fuel for state-of-the-art future nuclear reactors, this research focuses on a way to recover thorium from the monazite ore. The overall purpose of this research is to develop a conceptual recovery process that recovers thorium dioxide from monazite ore. In some parts of the world where uranium sources are limited; then, thorium could be used ...

Co2 Derived Carbon Capture Using Microalgae In A Photobiocrec Unit, Maureen D. Cordoba Perez

Electronic Thesis and Dissertation Repository

Microalgae has the potential to contribute to carbon dioxide capture, resulting in the production of alternative fuels and valuable chemical products. To accomplish this, high-efficiency photobioreactors must be conceptualized, designed, and established, in order to achieve high inorganic carbon conversion, superior light utilization, and unique fluid dynamics.

In this PhD Dissertation, experiments with Chlorella vulgaris were carried out, in a 0.175L especially designed PhotoBioCREC unit, under controlled radiation and high mixing conditions. This unique design involves 1 mm-2 mm alumina particles, which keep photoreactor walls always clean, without compromising photon transmittance. Sodium bicarbonate (NaHCO₃) was supplied as the ...

Experimental Study And Characterization Of Bubble Behaviors In The Orifice-Induced Hydrodynamic Cavitation, Haoxuan Zheng

Electronic Thesis and Dissertation Repository

Experimental studies were performed to characterize the development process of orifice-induced cavitation and transitional bubble behaviors. The transition from non-cavitation to fully developed cavitation was carefully studied. Cavitation bubble clouds were observed at orifice, indicating the inception of cavitation. The number of bubbles produced were dramatically increased while the averaged sizes of bubble reduced when cavitation was initiated. Both orifice opening ratio and perimeter can affect the cavitation developing process. A long orifice perimeter promotes the production of fine bubbles. The orifice plates with the smallest opening ratio generated a desired gas-liquid interfacial area at the lowest required pressure. An ...

Hydrogen Production Via Photocatalytic Water Splitting Under Near-Uv And Visible Light Using Doped Pd Tio2, Bianca Rusinque

Electronic Thesis and Dissertation Repository

The present PhD thesis reports the modification of titanium dioxide (TiO₂) with palladium (Pd), to enhance hydrogen production via water splitting, using 2.0v/v% ethanol as a scavenger. Titanium dioxide was used as photocatalyst, given its ability to absorb photons, producing e^-/h⁺ pairs. Mesoporous TiO₂ was synthesized using a soft template, following the sol-gel method, to modify its morphological properties. Palladium was used as co-catalyst doping TiO₂ agent, narrowing the band gaps down to 2.51 eV, and creating additional active metal sites.

Water splitting experiments under near-UV and visible light irradiation were carried out ...