Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 23 for “"Gas-to-Liquid"”.
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Polyatomic London Dispersion Forces and NMR Gas to Liquid Chemical Shifts
One of the most recent attempts to characterize inter-molecular dispersion forces is due to Homer and Percival, who used a modified Onsager-type reaction field approach coupled with the "buffeting" theory which accounts for the intimate effects of molecular encounters. In this thesis their overall …
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Atom-Based Computer Simulation Studies of Gas-to-Liquid Nucleation in Atmospherically Relevant Systems: Clarifying Discrepancies and Elucidating Mechanisms
… for all systems was thought simplistically to be a process that advances through the formation of critical clusters with a well-defined composition. Our results show intriguing nucleation mechanisms that challenge the aforementioned notion. We employed the simple TraPPE-UA (transferable …
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Towards Sustainable Electrosynthesis of Industrially Valuable Small Molecules
… calls for substantial advances in our ability to apply sustainably generated electricity as a means of making and breaking arbitrary chemical bonds. The development of such carbon-neutral systems demands the design of efficient and selective electrocatalysts with an eye towards economic …
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Monte Carlo computer simulation of the Lennard-Jones and Stockmayer fluid phase diagrams
The isotherms of the Lennard-Jones fluid and the Stockmayer fluid are calculated by Monte Carlo computer simulation using the constant NpT ensemble. Empirical coefficients are determined for a truncated virial equation of state fitted to our data. Spinodal points are located for each temperature …
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An analysis of the potential socio-economic impacts of shale gas development in South Africa
… is in the process of considering shale gas exploration applications in the Karoo basin. There are conflicting views on whether the development of the resource will be to the detriment or benefit of the South African economy. This paper makes use of a dynamic Computable General …
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The effect of metal type and loading on n-paraffin hydrocracking conversion and selectivity
… in global oil reserves, there is a growing need to develop alternative sources of conventional fuels to complement the current dependence on crude oil feedstocks. Natural gas, coal and biomass have been identified for this purpose. The distinctive advantage of using natural (stranded) gas is that …
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Air stripping and biological treatment of ammonium sulfate wastewater from the caprolactam manufacturing process
The objectives of this study were to determine the optimum operating conditions required for air stripping of ammonium sulfate wastewater from the caprolactam manufacturing process, to determine if biological nitrification is a viable means of treatment, and to identify any compounds present in the …
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Microbial oxidation of dodecane and tridecane into a,w-dicarboxylic acids using recombinant Yarrowia lipolytica
… intermediates, widely used as raw materials to synthesise products such as perfumes, hot-melting adhesives, engineering plastics and high quality lubricants. These acids can be obtained via chemical or biological routes by using various feedstocks such as linear alkanes. Linear alkanes are …
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Development of Catalytic Processes for the Transformation of Low Value Chemical Feedstocks to Value Added Chemicals
… oil reserves have necessitated the shift to alternative sources for fuels and commodity chemicals. This thesis describes fundamental studies and development of catalytic processes for the transformation of abundant, low value chemical resources into value added chemicals. Chapter 1 of this …
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Dynamical Phase-Change Phenomena
… mostly in three different phases of solid, liquid, and gas. With extreme amounts of energy, temperature, or pressure, a matter can be changed between the phases. Six different types of phase-change phenomena are possible: freezing (the substance changes from a liquid to a solid), melting …
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Development and Evaluation of a Comprehensive Tropospheric Chemistry Model for Regional and Global Applications
… various sub-models/mechanisms representing the gas-, aerosol-, and cloud-phase chemistries. The gas-phase model encompasses three tropospheric chemical regimes - background and urban, continental rural, and remote marine. The background and urban gas-phase mechanism is based on the paradigm of …
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Development of a sulfate reducing packed bed bioreactor for use in a sustainable hydrogen production process
… waste and its subsequent overall conversion to H2 via an exothermic reaction. The current study examined the first step of this process, namely, the design and operation of a packed bed bioreactor with high volumetric H2S production (mol/m3.d) and its comparison to analogous methanogenic …
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Reactor design for the hydroxylation of n-octane using a cyp153a6-based biocatalytic system expressed in Escherichia coli
Large stockpiles of linear hydrocarbons have arisen as by-products from the global expansion of gas-to-liquid refining processes. Furthermore, these linear alkanes feature one of the strongest chemical bonds in nature and typically are of a low value due to their inertness. In an effort to valorise …
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Particle matter emission control and related issues for diesel engines
… emissions. After years of research, people begin to understand it further, with respect to its impact on the environment and human health, its formation mechanism inside and outside the diesel engine, and most importantly, the methods to control its formation. This study has focused on the …
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Membrane-supported hydrogen/syngas production using reactive H₂O/CO₂ splitting for energy storage
Energy storage technologies are crucial for supporting the fast expansion of intermittent renewable energy at the grid scale. One such technology is the efficient and economic conversion of H₂O and CO₂ into fuels utilizing excess thermal energy at intermediate temperatures. This thesis explores …
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Effect of Local Bed Hydrodynamics on the Distribution of Liquid in a Fluidized Bed
In an industrial Fluid CokerTM, liquid bitumen is injected into a bed of hot coke particles through spray nozzles, grouped in several banks at different vertical positions. The main objective of this thesis is to determine whether significant improvements in liquid-solid contact could be achieved …
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Numerical study of vertical subcooled boiling flow with new wall nucleation models
… including nuclear power plants. Due to the decrease in computational cost and the limitations of experimental studies, CFD simulation is a proven, powerful tool in multiphase modeling. Understanding and predicting the process of wall nucleation are of particular significance in …
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Process intensification for the iron-catalysed slurry-phase Fischer-Tropsch Reactor System
… conditions was identified with the potential to enable improved slurryphase reactor productivity for hydrocarbon production using Fischer-Tropsch synthesis. Compared to the most relevant prior art publication, this requires operation at higher gas velocity, higher catalyst concentration and at …
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Nuovi catalizzatori per l'idrogenazione, l'idrogenolisi/ring-opening di composti aromatici policiclici
… regulations that require petroleum reï¬�ners to raise cetane number and to limit aromatics in diesel fuel in order to improve combustion efficiency and reduce particulate and NOx emissions. An alternative is blending with Fischerâ��Tropsch (FT) gas-to-liquid diesel fuel; however, this option …
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Predicting Transitions in Fischer-Tropsch Reactors
The Fischer-Tropsch process has the potential to be fundamental to a future without dependence on fossil fuels. It converts syngas, a readily available resource, into high quality hydrocarbons, with water being the primary byproduct. Like many gas-to-liquid processes, it is catalysed on a …
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