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Optical Measurements In Gas-Liquid Stirred Tanks, Sean Mueller
Optical Measurements In Gas-Liquid Stirred Tanks, Sean Mueller
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This dissertation outlines the development of novel, in-situ and relatively inexpensive optical measurement techniques for use in opaque multiphase reactors at elevated temperature: 350 ┬░C) and pressure: 180 bar) environments where conventional measurement techniques either cannot be used or are difficult or expensive to implement. Important parameters: such as gas holdup, specific interfacial area, bubble velocity, bubble chord lengths, liquid level, and phase transition) in opaque, multiphase reactors at industrially relevant conditions are lacking in the literature. A miniaturized 4-point probe is developed and methodology outlined that can simultaneously capture local gas holdup, interfacial area, size, and velocities of bubbles …
Zeolites For Cleaner Processes: Alkylation Of Isobutane And N-Butene, Subramanya Nayak
Zeolites For Cleaner Processes: Alkylation Of Isobutane And N-Butene, Subramanya Nayak
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Large pore beta zeolite with straight and zig-zag channels and USY zeolite with super cages have shown potential to replace toxic and hazardous mineral acids as catalysts in alkylation processes. However, due to rapid deactivation of these zeolites, their acceptance in industrial alkylation has been delayed. In this study we seek a deeper understanding of the kinetics, transport, and sorption of organic molecules used in alkylation processes in nano-porous zeolites. A six lump kinetic model that considers the key reactions for the zeolite catalyzed alkylation process is presented. The influence of different reactions and rate limiting steps on catalyst, and …
Enzymatic Enhancement Of Water Removal In The Dry Grind Corn To Ethanol Process, Ana Beatriz Thomas
Enzymatic Enhancement Of Water Removal In The Dry Grind Corn To Ethanol Process, Ana Beatriz Thomas
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The removal of water from coproducts in the fuel ethanol process requires a significant energy input. The drying of the coproducts is responsible for as much as 32% of the total utilities cost of the process. In this study, improvements in the energy and water balances of the corn to ethanol process and a decrease in ethanol production costs were achieved. Significant reductions in water-binding capacity of whole stillage were found for two, commercially available, cell wall degrading enzymes, GC220 and MGC. The addition of a protease, GC106, during fermentation was found to significantly enhance ethanol production rates as well …
Oxygen-Enhanced Combustion: Theory And Applications, Scott Skeen
Oxygen-Enhanced Combustion: Theory And Applications, Scott Skeen
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In the broadest sense, oxygen-enhanced combustion: OEC) refers to the use of oxygen to improve combustion and/or process characteristics. When a stream of oxygen is available, a wide range of flame configurations is possible. This work considers two specific configurations of OEC and is divided into two parts. In Part I, fundamental experimental and numerical flame studies explore the combustion of gaseous fuel/inert mixtures in oxygen-enriched air or pure oxygen under well-defined conditions. Part II targets a more practical application by considering the combustion of solid fuels in a variety of oxygen/carbon dioxide mixing scenarios. For gaseous non-premixed flames, combining …
Metal Oxide Semiconductors For Solar Energy Harvesting, Elijah Thimsen
Metal Oxide Semiconductors For Solar Energy Harvesting, Elijah Thimsen
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The correlation between energy consumption and human development illustrates the importance of this societal resource. We will consume more energy in the future. In light of issues with the status quo, such as climate change, long-term supply and security, solar energy is an attractive source. It is plentiful, virtually inexhaustible, and can provide more than enough energy to power society. However, the issue with producing electricity and fuels from solar energy is that it is expensive, primarily from the materials: silicon) used in building the cells. Metal oxide semiconductors are an attractive class of materials that are extremely low cost …
Getting To The Point: Bridging The Gap Between Simple And Complex Catalytic Systems Using Temporal Analysis Of Products (Tap), Xiaolin Zheng
Getting To The Point: Bridging The Gap Between Simple And Complex Catalytic Systems Using Temporal Analysis Of Products (Tap), Xiaolin Zheng
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One of the key issues in the field of catalysis is to relate the catalyst structure/composition to its activity/selectivity. One way to understand this relationship is to understand the individual role each catalyst component plays in the chemical reaction. Industrial catalysts can be extremely complex in structure and to understand their reaction kinetics, researchers often study simpler surfaces such as single crystals using surface science techniques. This introduces a well-known problem in the field of catalysis commonly referred to as the "pressure and materials gap." Typically, industrial catalyst research is performed under process conditions, which means operating pressures of one …