Catalysis and Reaction Engineering Commons^™

Change Of Metal Oxidation State At High Temperature, Impact Of Temperature And Reactive Gases, Yegor Nikitin

Dissertations and Theses

The fundamental understanding of gas-solid reactions enables a wide range of applications to be developed and improved. Specifically, the use of metal-based materials is critical to ensuring robust, safe, and long-term operations. For example, in power systems where boilers are used to generate steam for heat or electricity generation the use of stainless metal alloys is critical to allow high quality steam to be produced in a very harsh environment. Alternatively, in catalysis, the use of metal doped heterogeneous catalysts are essential in achieving selectivity and conversion performance for chemical synthesis to emissions abatement. Typically, these metal alloys must withstand …

Understanding The Kinetics And Mechanisms Of The Desired And Undesired Reactions During Electrochemical Hydrogenation And Hydrogenolysis Of Furfural On Copper In Acidic Media, Andrew S. May

Dissertations and Theses

The decarbonization of the chemical industry would have an immense impact on lowering greenhouse gas emissions and assisting in mitigating global warming. To achieve this there is a growing interest in implementing renewable feedstocks like biomass and coupling of chemical processes with renewable energy. Furfural is a biomass derived species that has been identified as a platform molecule. Electrochemical processes are more easily coupled with renewable electricity and can be used to valorize biomass derived species such as furfural. The installation of electrochemical processes is hindered by a smaller knowledge base compared to thermochemical processes. This dissertation investigates the electrochemical …

Investigations Of The Therman Treatment Of Sodium Thiosulfate In Gas Streams For The Removal Of I2, Anjeza Arapi

Dissertations and Theses

The aim of this work was to study the performance of sodium thiosulfate in several systems. Sodium thiosulfate decomposition and SO2 conversion were analyzed using thermogravimetric analysis combined with chromatographic techniques. Thermogravimetric analysis (TGA) measurements determined the decomposition of the acidification reaction of 30% sodium thiosulfate solution in a 14% carbon dioxide (CO2) atmosphere and 1% hydrochloric acid (HCl) solution in the temperature regime of 300 - 750 K. Sodium thiosulfate and sulfur dioxide (SO2) are considered effective methods for removing iodine (I2) from air and flue-gas streams respectively. In acid containing gas-streams where the SO2 content is determined by …

Elucidation Of The Catalytic Partial Oxidation Of Methane Utilizing The One-Of-A-Kind Catalytic Shock Tube Technique, Robyn E. Smith

Dissertations and Theses

The mechanism for the catalytic partial oxidation of methane has been debated in scientific literature for over 20 years. This is a seemingly simple reaction producing CO, CO₂, H₂ and H₂O through either partial oxidation followed by complete oxidation or complete oxidation followed by reforming steps. What is happening when the reaction is allowed to occur in an environment absent of transport limitations, absent of temperature gradients and temperature changes, absent of boundary layers must be understood and, until now, has yet to be achieved in one experimental technique.

A novel method using a one …

Intensification Of Gas Absorption In A Downward Flow Microbubble Bioreactor, Manizheh Ansari

Dissertations and Theses

Bioreactors are of interest for value-upgrading of stranded or waste industrial gases, such as CO, CH₄, or syngas. Process economics requires reduction of reactor cost and size while maintaining high production rate via rapid delivery of gas feedstock to the liquid phase which in turn requires a high volumetric mass transfer rate (). One strategy to achieve this goal is to increase interfacial area density, a, to >3000 m² m^-3, while minimizing use of energy. Here we show a novel reactor column design that uses a micro-jet array to break feedstock at ambient pressure …

A New Thin Layered Structural Coating On A Metal Substrate For Enhanced Hydrogen Production From Steam Methane Reforming, Michael A. Lugo-Pimentel

Dissertations and Theses

In the past decade the use of hydrogen has become more ubiquitous. Its applications range from the upgrading of fossil fuels, to the production of ammonia, to the hydrogenation of fats, to the production of muriatic acid and methanol, all without including the efforts being taken to move towards a hydrogen economy. Its widespread use and its increasing demand lays pressure to find more efficient techniques of hydrogen production. Because the overwhelming majority of hydrogen produced nowadays comes from the steam reforming of natural gas (SMR), it appears that the most adept way to improve yields is by improving the …

The Role Of Environmental Dynamics In The Emergence Of Autocatalytic Networks, Joe Fusion

Dissertations and Theses

For life to arise from non-life, a metabolism must emerge and maintain itself, distinct from its environment. One line of research seeking to understand this emergence has focused on models of autocatalytic reaction networks (ARNs) and the conditions that allow them to approximate metabolic behavior. These models have identified reaction parameters from which a proto-metabolism might emerge given an adequate matter-energy flow through the system. This dissertation extends that research by answering the question: can dynamically structured interactions with the environment promote the emergence of ARNs? This question was inspired by theories that place the origin of life in contexts …

A Metal-Free Approach To Biaryl Compounds: Carbon-Carbon Bond Formation From Diaryliodonium Salts And Aryl Triolborates, Kuruppu Lilanthi Jayatissa

Dissertations and Theses

Biaryl moieties are important structural motifs in many industries, including pharmaceutical, agrochemical, energy and technology. The development of novel and efficient methods to synthesize these carbon-carbon bonds is at the forefront of synthetic methodology. Since Ullmann’s first report of stoichiometric Cu-mediated homo-coupling of aryl halides, there has been a dramatic evolution in transition metal catalyzed biaryl cross-coupling reactions.

Our work focuses on the discovery and development of an unprecedented reagent combination for metal-free cross-coupling. It is hypothesized that direct carbon-carbon bond formation occurs via a triaryl-λ³-iodane and that electrophile/nucleophile pairing is critical for success in the reaction. Proof-of-concept …