<p>Petroleum products, such as base oils and jet fuels, play an essential role in modern society since they are necessary as lubricants for engines and as fuels for airplanes. The ability to accurately characterize these petroleum products is crucial for the successful generation of these compound mixtures with desirable properties. Unfortunately, analysis of petroleum products remains challenging due to the fact that they often contain thousands of different hydrocarbons. The petroleum industry relies heavily on powerful analytical techniques to evaluate the chemical compositions of petroleum products in order to improve their crude oil refinery procedures. Tandem mass spectrometry is the only analytical technique that has the potential to provide both elemental composition and structural information for individual analytes in complex mixtures. When coupled to chromatography, different tandem mass spectrometry methods facilitate the analysis of individual hydrocarbons in complex mixtures and therefore provide more detailed compositional information for petroleum products than other analytical methods. Fundamental studies that explore the physical and chemical properties of hydrocarbons also facilitate the development of new mass spectrometric ionization techniques for these analytes. The research discussed in this dissertation can be divided into three parts: the development and validation of new quantitation methodology for compounds representing twelve different hydrocarbon types in jet fuels (Chapters 3), the comparison of (+)APCI MS and GCxGC/(+)EI TOF MS for the analysis of saturated and aromatic hydrocarbons in group III heavy base oils (Chapter 4), and experimental measurement of proton affinities of alkanes (Chapter 5).</p>

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<p>  This dissertation focuses on the examination of the influence of sample storage conditions on the accuracy and precision of hydrocarbon composition measurements of Jet A made with GC×GC/FID and the accuracy and precision of flash point measurements of Jet A made with a Tag closed cup flash point tester. Areas of focus also include the influence of the column load value used, the S/N threshold value used, and the number of measurements made for a single sample vial on the accuracy and precision of the GC×GC/FID results. This dissertation also describes the development of an analytical method for the identification and quantitation of alkylphenols in Jet A (which are the most abundant heteroatom containing compounds in jet fuel) by using preparative high-performance liquid chromatography (prep-HPLC) and two-dimensional gas chromatography with electron ionization time-of-flight mass spectrometry (GC×GC/(+)EI TOF MS).</p>

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Orientador: Celso Eduardo Tuna / Resumo: Com a criação de combustíveis alternativos para a redução de emissões de CO2 no setor aeronáutico, torna-se necessária a determinação de suas propriedades de segurança e, entre elas destacam-se os limites de inflamabilidade. O combustível alternativo aeronáutico, que é utilizado neste trabalho, é o farnesano, fabricado a partir da cana de açúcar, por um processo que transforma açúcar em hidrocarboneto, pela empresa Amyris, localizada em São Paulo, Brasil. O objetivo dessa dissertação é determinar experimentalmente os limites de inflamabilidade, inferior (LII) e superior (LSI) do farnesano, QAV e misturas de 10% (F10) e 50 % (F50) em massa de farnesano com o QAV a pressões reduzidas em ar. Utiliza-se uma bancada experimental, que segue a norma americana ASTM E681, para a determinação dos limites de inflamabilidade, em que se utiliza o critério visual de propagação de chama e um recipiente de vidro borosilicatado de 20,716 L. Primeiramente são determinados os limites de inflamabilidade dos combustíveis para a pressão de 101,3 kPa em temperaturas entre 140 e 220°C, comparando-se os resultados com os valores teóricos disponíveis na literatura para a validação do procedimento experimental. Em segundo lugar, são determinados os limites de inflamabilidade das amostras a pressões reduzidas como 80, 60, 40 e 20 kPa em temperaturas entre 140 e 200°C. Foram realizados, no total 636 testes para determinação dos limites de inflamabilidade, sendo a duração média, para cada teste de 20 minu... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The creation of alternative fuels to reduce CO2 emissions from the aeronautical sector needs determination of their safety properties, among which are flammability limits. farnesane is the alternative aviation fuel used in here, which has been produced from sugar cane through a conversion process known as direct sugar to hydrocarbon (DSHC) created by a company called Amyris, which is located in São Paulo, Brazil. Thereby, it is aimed to experimentally determine the flammability limits, lower (LFL) and upper (UFL) of farnesane, Jet fuel and mixtures of 10% (F10) and 50% (F50) in mass of farnesane at reduced pressures with air. For such a purpose, an experimental bench was built in accordance with American standard ASTM E681 to determine the lower flammability limits, in which flame propagation was analyzed visually through a 20.716 L borosilicate glass flask. The Flammability Limits of the fuels were initially determined at a pressure of 101.3 kPa and temperatures ranging between 140 and 220 ° C, whose results were compared with theoretical values found in literature in order to validate the experimental procedure. Afterwards, the Flammability Limits of samples were determined at reduced pressures, i.e. 80, 60, 40 and 20 kPa, and temperatures ranging between 140 and 200 ° C. 636 tests were performed altogether, the average time of each test was 20 minutes. Finally, prediction equations of flammability limits, were presented as a function of temperature / Mestre

Darbe tirta tiekiamo oro temperatūros, deginių recirkuliacijos ir degalų savybių įtaka suslėgimu uždegamo homogeninio oro – bioetanolio mišinio degimo procesui, variklio darbo ir deginių emisijos rodikliams. Nustatytos variklio darbo homogeniniu oro – bioetanolio mišiniu maksimalios apkrovos zona, kurią riboja slėgio didėjimo greitis ir susidarantis detonacinis degimas. Gautieji rezultatai varikliui veikiant bioetanoliu, lyginti su rezultatais gautais varikliui veikiant baziniais degalais – benzinu. Dyzeliniam varikliui dirbant homogeniniu oro ir bioetanolio mišiniu, keičiant tiekiamo oro temperatūrą, naudojant deginių recirkuliaciją ir įmaišant 20 % reaktyvinių degalų, azoto oksidų emisijos lieka dešimtis kartų mažesnės negu tradicinio dyzelinio variklio. Slegiamo homogeninio oro – bioetanolio mišinio užsiliepsnojimui valdyti pirmą kartą panaudoti reaktyviniai degalai. / It was found that the intake air temperature, exhaust gas recirculation and fuel properties have the influence on the combustion characteristics of homogeneous air – bioethanol mixture, engine performance and emissions. The operating region was found at which critical rate of pressure rise was unacceptably high and engine worked at “knocking” combustion. In order to assess the combustion process in homogeneous charged compression ignition (HCCI) mode fuelled with the air – bioethanol mixture, it was compared whit the combustion process in HCCI mode fuelled with the air – gasoline mixture. When the diesel engine works in HCCI mode fuelled with air – bioethanol mixture, the nitrogen oxides can be reduced more than 10 times compared with normal diesel operation. For the first time, to control the autoignition of compressed homogeneous air and bioethanol mixture, the JET A1 fuel was simultaneously added in to combustible mixture in this study.

Orientador: Hung Kiang Chang / Resumo: O presente estudo explora a avaliação da distribuição de Light Non-Aqueous Phase Liquid (LNAPL) trapeado na zona saturada empregando a técnica de fluorescência induzida por laser (Laser-Induced Fluorescence – LIF). A área de estudo está localizada no município de Paulínia e tem sido investigada para contaminação por Querosene de Aviação (QAV) desde 2002. O equipamento Ultra-Violet Optical Screening Tool (UVOST®) foi utilizado por possuir a capacidade de detectar moléculas de Hidrocarbonetos Policíclicos Aromáticos (PAH) presentes no LNAPL. Foram realizados um teste piloto de bancada e 21 ensaios de perfilagem LIF em campo, incluindo monitoramento de nível d’água (NA) e nível de óleo (NO) sobrenadante em poços existentes. A perfilagem LIF foi empregada para definir com precisão a extensão lateral do LNAPL, bem como sua tipologia. Além disso, a integração de resultados de fluorescência, oscilação sazonal do NA, espessura de QAV e concentração de naftaleno conduziu para um entendimento mais claro da migração lateral e vertical do LNAPL em subsuperfície. Elevadas intensidades de fluorescência relacionadas ao QAV foram detectadas abaixo do NA na situação de descida do LNAPL em períodos de NA baixo, revelando migrações verticais pretéritas, e correspondem à presença de fase livre nesses períodos, previamente registradas em poços de monitoramento. Análises estatísticas dos quatro canais distintos (comprimentos de onda de 350 nm, 400 nm, 450 nm e 500 nm) mostraram forte correlação en... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: The present study explores the distribution evaluation of Light Non-Aqueous Phase Liquid (LNAPL) trapped in the saturated zone using Laser-Induced Fluorescence (LIF) technique. The study site is located in the Paulínia municipality and has been investigated for jet fuel contamination since 2002. Ultra-Violet Optical Screening Tool (UVOST®) was used for its capability in detecting Polycyclic Aromatic Hydrocarbon (PAH) molecules present in LNAPL. One pilot test and 21 LIF profiling tests were carried out in the field, including water table (WT) and floating oil level (OL) monitoring in existing wells. LIF profiling was employed to accurately define the lateral extension of weathered LNAPL, as well as its typology. In addiction, the integration of fluorescence results, seasonal fluctuation of WT, jet fuel thickness and naphthalene concentration led to a clear understanding of lateral and vertical migration of the LNAPL in the subsurface. High fluorescence intensities related to the jet fuel were detected below the WT in the situation of falling LNAPL in low WT season, revealing past vertical migration, and these correspond to the presence of free phase in periods of low WT, previously registered in monitoring wells. Statistical analysis of the four distinct channels (wavelength of 350 nm, 400 nm, 450 nm and 500 nm) showed correlation between the referred wavelengths in the presence of the contaminant, allowing differentiating with better refinement the horizons with the presence... (Complete abstract click electronic access below) / Doutor

<p>Aviation fuels are complex mixtures that mostly consist of a wide range of different hydrocarbons but also contain small amounts of heteroatom-containing compounds. Different fuels can have very different physical and chemical properties (e.g., storage and thermal stabilities are influenced by the heteroatom-containing compounds), with some performing better as fuels than others. To address this situation, correlations need to be developed between the chemical composition of fuels and their properties. This requires that the chemical compounds in fuels are correctly characterized, which is challenging. Because of the large number and many different types of organic compounds present in fuels, separation of these compounds by using techniques such as one- (GC) and -two-dimensional gas chromatography (GC×GC) is necessary before mass spectrometric characterization. Furthermore, analysis using traditional electron ionization (EI) mass spectrometry is hampered by excessive fragmentation that often leads to complete absence of a stable molecular radical cation, thus preventing the determination of the molecular weight (MW) of the analyte. To explore alternative methods, GC coupled with methane chemical ionization (CI) triple quadrupole mass spectrometry and GC×GC coupled with methane CI time-of-flight high-resolution mass spectrometry, both in the positive-ion mode, were tested. While both chromatographic techniques separate volatile organic chemicals via boiling point and intermolecular forces, GC×GC methods incorporate a greater level of separation by taking advantage of secondary column of different polarity. This additional level of separation can help separate overlapping compounds that would be impossible in GC. What comes to mass spectrometry analysis, methane CI was found to be more predictable and “softer” than the traditionally employed EI. Several ions revealing the MW of the analyte, e.g., M+•, [M+H-H2]+, and/or [M+H]+, were generated for almost every compound studied with some associated fragmentation. These fragmentation patterns provided invaluable structural information. When combined with the number of carbon atoms in the diagnostic ions, double bond and ring equivalent (DBRE) values, and elemental compositions, all obtained from highly accurate mass measurements performed using the time-of-flight mass spectrometer (but not the quadrupole), the classification of the compounds was possible. In some instances, even the unambiguous identification of individual compounds in aviation fuels was possible.</p>

The use of geosynthetic clay liners (GCLs) as (i) covers for arsenic-rich gold mine tailings and landfills, (ii) subsurface barrier for migration of hydrocarbons in the Arctic, and (iii) basal liner for sewage treatment lagoons were examined. After 4 years in field and laboratory experiments, it was found that best cover configuration above gold mine tailings might include a layer of GCL product with polymer-enhanced bentonite and a geofilm-coated carrier geotextile serving above the tailings under ≥ 0.7 m overburden. However, acceptable performance could be achieved with using a standard GCL with untreated bentonite provided that there is a minimum of 0.7 m of cover soil above the GCL. When GCL samples were exhumed from experimental landfill test cover with complete replacement of sodium in the bentonite with divalent cations in the adjacent soil, it was observed that the (i) hydraulic head across the GCLs, (ii) size of the needle-punched bundles, and (iii) structure of the bentonite can all significantly affect the value of the inferred in-situ hydraulic conductivity measured at the laboratory. The higher the hydraulic head and the larger the size of the needle-punched bundles, the higher the likelihood of internal erosion/structural change of bentonite at bundles that will cause a preferential flow for liquids to occur. A key practical implication was that GCLs can perform effectively as a single hydraulic barrier in covers provided that the water head above the GCL kept low. The hydraulic performance of a GCL in the Arctic was most affected by the location within the soil profile relative to the typical groundwater level with the highest increase in the hydraulic conductivity (by 1-4 orders of magnitude) for GCL below the water table. However, because the head required for jet fuel to pass through the GCL was higher than that present under field conditions, there was no evidence of jet fuel leakage through the barrier system. The leakage through GCLs below concrete lined sewage treatment lagoons was within acceptable limits, in large part, due to the low interface transmissivity between GCLs and the overlying poured concrete. / Thesis (Ph.D, Civil Engineering) -- Queen's University, 2014-02-28 08:53:29.171