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The Global ETD Search service is a free service for researchers
to find electronic theses and dissertations. This service is
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Networked Digital Library of Theses and Dissertations.
Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
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Showing 141 to 144 of 144 (0.071 seconds)| 141 |
THE DEVELOPMENT OF MASS SPECTROMETRIC METHODS FOR THE DETERMINATION OF THE CHEMICAL COMPOSITION OF COMPLEX MIXTURES RELEVANT TO THE ENERGY SECTOR AND THE DEVELOPMENT OF A NEW DEVICE FOR CHEMICALLY ENHANCED OIL RECOVERY FORMULATION EVALUATIONKatherine Elisabeth Wehde (8054564) 28 November 2019 (has links)
<p>This dissertation focused on the development of mass
spectrometric methodologies, separation techniques, and engineered devices for
the optimal analysis of complex mixtures relevant to the energy sector, such as
alternative fuels, petroleum-based fuels, crude oils, and processed base oils.
Mass spectrometry (MS) has been widely recognized as a powerful tool for the
analysis of complex mixtures. In complex energy samples, such as
petroleum-based fuels, alternative fuels, and oils, high-resolution MS alone may
not be sufficient to elucidate chemical composition information. Separation
before MS analysis is often necessary for such highly complex energy samples.
For volatile samples, in-line two-dimensional gas chromatography (GC×GC) can be used to separate complex
mixtures prior to ionization. This technique allows for a more accurate
determination of the compounds in a mixture, by simplifying the mixture into
its components prior to ionization, separation based on mass-to-charge ratio (<i>m/z</i>), and detection. A GC×GC coupled to a high-resolution
time-of-flight MS was utilized in this research to determine the chemical
composition of alternative aviation fuels, a petroleum-based aviation
fuel, and alternative aviation fuel candidates and blending components as well
as processed base oils.</p>
Additionally, as the cutting edge of science and
technology evolve, methods and equipment must be updated and adapted for new
samples or new sector demands. One such case, explored in this dissertation,
was the validation of an updated standardized method, ASTM D2425 2019. This
updated standardized method was investigated for a new instrument and new
sample type for a quadrupole MS to analyze a renewable aviation fuel. Lastly,
the development and evaluation of a miniaturized coreflood device for analyzing
candidate chemically enhanced oil recovery (cEOR) formulations of brine,
surfactant(s), and polymer(s) was conducted. The miniaturized device was used
in the evaluation of two different cEOR formulations to determine if the components
of the recovered oil changed.
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Experimental study of surfactant-aided enhanced oil recovery in carbonate rockKühne, Jonathan 16 August 2024 (has links)
The application of surfactants and polymers in carbonate reservoirs has a high potential with emerging technology of the manufacture of these chemicals. Tertiary or enhanced oil recovery with chemicals (CEOR) will become more relevant with decreasing new exploration of oil deposits and high remaining oil saturations in huge carbonate oil reservoirs. However, in several oil deposits, high reservoir brine salinity and moderate to high reservoir temperature are encountered. Under such conditions, many chemicals will be insoluble or degrade fast. A selection of commercial and research surfactants and polymers has been investigated for their application under brine salinity of up to 18 percent by weight with significant hardness and a moderate reservoir temperature of 70 °C. Chemical systems were tested towards outcrop limestone rock samples and calcite platelets in combination with a crude oil, which was modified by different organic acids regarding its wetting potential. Wettability alteration from preferentially oil-wet core plugs was pursued with ethoxylated tertiary amines and quaternary ammonium compounds. The main mechanism of wettability alteration towards more water-wet was proposed as extraction of carboxylate anions from the oil phase and the solid samples into aqueous micelles. Thus, high surfactant concentrations would result in improved recovery. From screening of different surfactant combinations in tertiary core flooding, one promising system of an alkyl ether sulfate and hexadecyltrimethylammonium combined with a terpolymer (TP) from acrylic acid, ATBS and NVP is proposed for the examined conditions. Low to moderate adsorption of the single surfactants and their combination as well as a favorable, stabilized phase behavior when combined with the polymer emphasize the applicability of the system. However, long term stability can be an issue with respect to the sulfate surfactant degradation at 70 °C. Analysis of mixed ionic surfactant systems after adsorption testing has been successfully pursued with a combined TC/TNb-determination.
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Kurz- und langfristige Angebotskurven für Rohöl und die Konsequenzen für den MarktSchlothmann, Daniel 20 April 2016 (has links) (PDF)
In dieser Arbeit wurden Angebotskurven für 22 bedeutende Ölförderländer ermittelt und anschließend zu globalen Angebotskurven aggregiert. Gemäß den ermittelten Angebotskurven sind nahezu alle gegenwärtig in der Förderphase befindlichen Ölprojekte in den Untersuchungsländern auch beim aktuellen Ölpreis von 35 bis 40 US-$ je Barrel unter Berücksichtigung der kurzfristigen Grenzkosten rentabel. Sollte der Ölpreis jedoch in den kommenden Jahren auf diesem Niveau verharren, wird es bis zum Jahr 2024 zu einem Angebotsengpass auf dem globalen Ölmarkt kommen, da zur Deckung der zukünftigen Nachfrage die Erschließung kostenintensiver, unkonventioneller Lagerstätten und von Lagerstätten in tiefen und sehr tiefen Gewässern notwendig ist. Damit es bis zum Jahr 2024 nicht zu einem solchen Angebotsengpass kommt, ist gemäß des ermittelten langfristigen Marktgleichgewichts ein Ölpreis von mindestens 80 (2014er) US-$ je Barrel notwendig.
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| 144 |
Kurz- und langfristige Angebotskurven für Rohöl und die Konsequenzen für den MarktSchlothmann, Daniel 08 March 2016 (has links)
In dieser Arbeit wurden Angebotskurven für 22 bedeutende Ölförderländer ermittelt und anschließend zu globalen Angebotskurven aggregiert. Gemäß den ermittelten Angebotskurven sind nahezu alle gegenwärtig in der Förderphase befindlichen Ölprojekte in den Untersuchungsländern auch beim aktuellen Ölpreis von 35 bis 40 US-$ je Barrel unter Berücksichtigung der kurzfristigen Grenzkosten rentabel. Sollte der Ölpreis jedoch in den kommenden Jahren auf diesem Niveau verharren, wird es bis zum Jahr 2024 zu einem Angebotsengpass auf dem globalen Ölmarkt kommen, da zur Deckung der zukünftigen Nachfrage die Erschließung kostenintensiver, unkonventioneller Lagerstätten und von Lagerstätten in tiefen und sehr tiefen Gewässern notwendig ist. Damit es bis zum Jahr 2024 nicht zu einem solchen Angebotsengpass kommt, ist gemäß des ermittelten langfristigen Marktgleichgewichts ein Ölpreis von mindestens 80 (2014er) US-$ je Barrel notwendig.:1. Einleitung
2. Rohöl - Eine naturwissenschaftliche Einführung
3. Charakteristika von Rohölprojekten
4. Historie der Ölindustrie
5. Ökonomik von Rohölprojekten
6. Fallstudien zu den bedeutendsten Förderländern
7. Ermittlung regionaler und globaler Angebotskurven
8. Zusammenfassung
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