Modeling the transport and fate of spilled crude oil is important for estimating short and long-term toxicity effects in coastal ecosystems. This research project investigates the partitioning of hydrocarbons from a surface crude oil slick, the resurfacing of chemically dispersed crude oil droplets, the suitability of in-situ field instruments for oil and sediment characterization, and the aggregation and settling of dispersed oil and suspended sediments. An initial laboratory study was conducted to investigate apparent hydrocarbon solubility in petroleum/water systems. Mixing shear and initial crude oil layer thickness were related empirically to oil entrainment rate. A model describing hydrocarbons partitioned in colloidal and soluble phases was consistent with experimental data. A second laboratory study was conducted to investigate the influence of coalescence kinetics on mean droplet size and resurfacing rate of chemically dispersed crude oil droplets. Increased mean shear rates resulted in mean droplet diameters and oil resurfacing rates. A third laboratory study was conducted to compare particle size and fractal dimension measurements obtained using a submersible flow cytometer, an electrozone particle counter, and a light scattering particle sizer. Measured particles included latex beads, crude oil, clay, crude oil-clay aggregates, and crude oil-silica aggregates. Tested instruments gave consistent size measurements for all particle systems, suggesting their suitability for sizing marine particles. To describe the aggregation kinetics of oil-sediment systems, a modified Smoluchowski model based on coalesced sphere (CS) assumptions was developed. Observed collision efficiency values (αOBS) were related to collision efficiency values for single particle type systems (αHOMO) and those for two particle type systems (αHET) using a probabilistic approach. For clay and crude oil, αHOMO values were higher than the αHOMO value for silica. Clay-oil and silica-oil have similar αHET values. Thus, crude oil can significantly increase the aggregation rates of noncohesive sediments such as silica. The CS model above was modified to incorporate sediment fractal geometry. The ability of this modified coalesced fractal sphere (mCFS) model to fit experimental data sets was better than that of a coalesced sphere (CS) model. Because of their reduced settling rates, sediments with lower fractal dimension form more aggregate with dispersed oil.

The purpose of this study is to isolate and identify the crude oil-degrading bacteria from oil polluted soil. Their physiological characteristics and oil-degrading capability were also studied. Eight polluted soil samples were taken from the Kaohsiung Refingery Factory of the Chinese Petroleum Corporation (CPC). The microbiota of the Kaohsiung refinery soil sample P37-2 (#6) could degrade crude oil from 2000 ppm to 572 ppm in 10 days. Bacteria in polluted soil samples were selected and isolated by minimal medium with 2000 ppm crude oil as the sole carbon source. Biochemical test, PCR-DGGE, and 16S DNA sequencing were used to identify and characterize the bacteria isolates. Three strains were identified as Pseudomonas aeruginosa (NSYSU-1-1), Acinetobacter sp. (NSYSU-4-1), and Pseudomonas sp. (NSYSU-7-1). These three strains and microbiota #6 were tested for their capability of degrading the total petroleum hydrocarbons (TPH). We found that microbiota #6 performed better than the other three bacterial strains in degrading the crude oil. In this study, we also found temperature was not the major factor of influcing the biodegradation; however, high oxygen concentration and providing nitrogen soure couled improve the biodegradation rate. Although both NSYSU-1-1 and NSYSU-7-1 are Pseudomonas strains, they performed different on degrading the oil. All strains tested could degrade the crude oil to a concentration below 1000 ppm to meet the government emission standard. The bacterial strains and techniques developed in this study provide a choice for future bioremediation of crude oil pollution.

No description available.

Environmental liability cases involving spilled or released petroleum products into ocean ecosystems require oil identification techniques that are unambiguous and conclusive, even in situations where oils have been subjected to secondary environmental processes, such as, evaporation and dissolution. The ability and functionality of the Compound Specific Isotope Correlation (CSIC) technique is tested to determine its reliability to characterize released petroleum using the carbon isotope ratios (13C/12C) of the individual gasoline-range compounds (C5-C9). In particular, this thesis studies the potential of CSIC as a robust diagnostic tool, to identify and correlate marine releases of oil with their sources, especially those having undergone evaporative weathering. Three crude oils (Alberta Sweet Mixed Blend, Lacula and Louisiana) added to synthetic seawater were exposed to mechanically simulated wave energy and controlled evaporative weathering at 10 oC. Time-series sampling of the gasoline-range vapour fractions from the headspace employed Solid Phase Micro Extraction (SPME). SPME-Continuous Flow-Isotope Ratio Mass Spectrometry (SPME-CF-IRMS) determined the molecular abundances and stable carbon isotope ratios (δ13C) of the gasoline-range compounds of the original and weathered oils. Evaporation rates over the maximum 20 hour period varied for the 3 study oils. Most (74%) of the individual compounds measured in the oils display a δ13C enrichment with progressive evaporation with approximately half of the compounds in all 3 oils showing fractionation of the carbon isotopes ≤ 0.5‰ within measurement precision. The magnitude of carbon isotope shift observed in compounds pre-vs. post-weathering ranges from 0 to 2.8 ±0.6‰. There is no clear relationship identified between the degree of 13C enrichment in the oils and groupings such as chemical class, structure or carbon number. The overall weighted average 13C enrichment for all compounds in the 3 oils is approximately 1‰. Toluene was the only compound consistently exhibiting comparatively high 13C enrichment (1.6‰, 1.8‰ and 2.8‰) in all 3 oils after evaporative weathering. Hierarchical Cluster Analysis (HCA) treatment of the CSIC data set can reliably discriminate between the 3 oils despite evaporative weathering and δ13C changes. HCA is also able to unambiguously relate the three weathered oils back to their respective original unweathered oil. Diagnostic shifts in δ13C of individual compounds in an oil may potentially be used to trace weathered oils back to the source, and possibly give a estimation of time since release. However the typically rapid rate of evaporation for the gasoline-range fractions limits the time that an oil can be successfully identified by CSIC. / Graduate

No description available.

The scope of this study is to provide an understanding of crude oil price determination. The approach to this general problem starts by identifying the key areas that will help us achieve the specific objectives of the research which are the derivation of both a theoretical and an empirical framework of price formation. The areas examined are: depletion theory (chapter one), the evolution of the oil industry's structure and pricing practices (chapter two), the literature concerned with explaining that evolution (chapter three). A critique of that literature enables the derivation of the theoretical framework which can be called the transition period scenario - the transition from the centrally planned industry of the 1950s to the competitive market of the 1980s. Crude oil prices since .1970 have been determined not by a cartel of producers but by an imperfect market, within which inefficiencies, imperfect information, lags in adjustment and uncertainty together with the major oil companies fading power and the OPEC group following rather than leading the market - despite the perception of it as a cartel - have all combined to formulate prices. The attempt to confirm or reject that framework by empirical testing starts by choosing a specific methodology which is believed to be superior to conventional econometric techniques: The Box and Jenkin's approach to modelling time series, testing for causality patterns and determining lead and lag relationships, by thorough empirical investigation of the data rather than by arbitrary specification of causality directions and lag structures (chapter four). Application of that methodology to the data collected yields the results presented in chapters six and seven, which confirm the basic hypothesis and supply the functions which describe the true behaviour of the system and can therefore be used for forecasting. The major conclusion emerging from the study is that OPEC should not be thought of as a cartel. The demand for crude oil being a derived demand, it is the final consumers who will in the end dictate whether or not we are likely to face further price crises or whether spot markets will be calm and orderly. Nevertheless, the high proportion of world reserves in OPEC member countries means that OPEC can assist in the prevention of abrupt price changes by assuming a supervisory role rather than attempting in vain to assume an administrating role.

Made available in DSpace on 2018-08-01T21:36:54Z (GMT). No. of bitstreams: 1 tese_11042_Dissertação Lucas Queiroz - FINAL APROVADA.pdf: 801845 bytes, checksum: c02d945e52f528faf6319ad6dda19507 (MD5) Previous issue date: 2017-06-14 / A Destilação é um dos processos mais importantes na caracterização do petróleo pois o separa em diferentes frações. O conhecimento da distribuição dos pontos de ebulição dos componentes do petróleo e da proporção de seus cortes é essencial para o controle e logística desse processo durante o refino, além de garantir sua qualidade e possibilitar a valoração do óleo cru. Os métodos laboratoriais mais utilizados atualmente para este fim são as ASTM D2892 (destilação atmosférica: atinge temperatura máxima de 400 ºC) e ASTM D5236 (destilação a vácuo: utiliza pressões reduzidas para destilar o resíduo atmosférico para evitar o craqueamento das moléculas). A curva PEV (curva de pontos de ebulição verdadeiros - resultado laboratorial da destilação física) é obtida através da soma dos resultados das destilações atmosférica e a vácuo. Entretanto, esses processos demandam grandes quantidades de amostra (de 5 a 40 L) e tempo (3 a 4 dias). A Destilação Simulada por cromatografia gasosa (SIMDIS, do inglês Simulated Distillation) se apresenta como uma interessante solução para contornar esses problemas. A amostra é volatilizada e a separação de seus compostos ocorre no interior de uma coluna cromatográfica sob uma variação de temperatura controlada, produzindo um cromatograma e uma curva PEV. Neste trabalho, 98 amostras de petróleo nacionais e internacionais foram analisadas e seus dados foram correlacionados em diferentes etapas. Inicialmente, cada amostra foi analisada utilizando o método ASTM D7169 (SIMDIS) no laboratório de cromatografia do LabPetro na Universidade Federal do Espírito Santo (UFES). Essa etapa gerou 4 replicatas.para cada amostra, as quais foram submetidas a uma avaliação de similaridade para determinar qual apresentou o melhor resultado. Os dados da melhor replicata foram correlacionados com os obtidos no Centro de Pesquisas e Desenvolvimento Leopoldo Américo Miguez de Mello (CENPES-Petrobras). A primeira comparação foi uma avaliação de similaridade realizada entre os resultados de SIMDIS dos dois laboratórios, realizada para 44 amostras (amostras cujos resultados de SIMDIS foram disponibilizados pelo CENPES). Em seguida, os dados de SIMDIS obtidos na UFES foram correlacionados com os da destilação convencional do CENPES-Petrobras. A correlação dos resultados se deu através da comparação dos valores de ponto de ebulição a cada 5% de recuperação em massa. A fim de obter esses valores para as duas técnicas, foi feito um ajuste polinomial de quinta ordem. Por fim, foi aplicado um teste de Viés para para avaliar a correlação dos dados. A avaliação final dos resultados evidenciou uma boa similaridade entre os resultados da destilação convencional e SIMDIS. A correlação para 13 petróleos (de um total de 15) obteve bons, não exibindo erros sistemáticos significativos.

Energy based on non-renewable resources such as gas, oil, coal and nuclear fission, even with their serious problems of pollution, contributes to 86% of the global energy consumption. Oil will remain the dominant transport fuel: about 87% of transport fuel in 2030 will still be petroleum-based. Discoveries of conventional sources of light easy-to-access crude oil are becoming less common and current oil production levels are struggling to match demand, it is necessary to develop new non-conventional sources of oil in order to supplement conventional oil supply, whose demand is increasing continuously. A possible clue to solve this situation could be to take advantage of the extensive reserves of heavy crude oils existing in different places around the world, which could be an excellent source of more valuable hydrocarbons. In this context, some facilities called upgraders are used to process theses heavy crude oils to both increase the hydrogen-carbon ratio and improve their quality, reducing their density and decreasing their viscosity, sulphur, nitrogen and metals. The main objective in this work is to study the heavy crude oil upgrading processes in order to identify new operation schemes which explore different opportunities of integration between the upgraders and other processes or new schemes for upgraders that can sustain on its own through the production of a wide range of products. Each design alternative has been modelled with state-of-the-art commercial software packages. The crude oil dilution process was evaluated using naphtha and a light crude oil as diluents. Sensitivity analyses were done with the purpose of selecting the type and flow rate of diluent. Once the best diluent was selected, the integration of an upgrader to a refinery was studied. Heavy ends from both the upgrader and the refinery were taken as feedstocks to an integrated gasification combined cycle (IGCC). The best operation schemes for IGCC, in order to achieve the requirements of power and hydrogen for the upgrader and the refinery was determined. Different schemes for heavy crude oil processing to produce transportation fuel instead of syncrude were proposed, too. Finally, economic evaluation of all the schemes was performed to find the best solution for heavy crude oils. The best results for the dilution process of heavy crude oils were obtained when naphtha was used as diluent. The configuration proposed for the upgrader allows producing a synthetic crude oil with 35.5 °API. The integration of the upgrader to a refinery allows the treatment of the heavy streams of the refinery and transforms them into products of higher qualities. The integration of the IGCC to the upgrader and the refinery permits a complete elimination of the heavy residues produced in these units and produces hydrogen and power to be used in the site or to export. Economic evaluation shows that all the proposed processing schemes studied are economically attractive. The proposed processing schemes chosen include the integration between upgrader refinery and IGCC unit with CCS.

With demand for gasoline and diesel expected to decline in the near future, crude-tochemicals technologies have the potential to become the most important processes in the petrochemical industry. This trend has triggered intense research to maximize the production of light olefins and aromatics at the expense of fuels, which calls for disruptive processes able to transform crude to chemicals in an efficient and environmentally friendly way. Simultaneously, the production of high-demand chemical commodities such as olefins, aromatics and gasoline from alternative feedstocks such as methanol has been central to research in both academia and industry. In both conversions, catalyst composition and formulation play a key role. In principle, shaping and optimal compositional formulation are major challenges in the successful industrial application of heterogeneous catalysts. Herein, we evaluate the application of the spray-drying shaping technique to manufacture spherical zeolite-based catalysts and their applicability in the direct crude-to-chemicals and the methanol-to-hydrocarbons processes. A thorough study of the effect of formulated fluid catalytic cracking catalyst composition on the one-step cracking of Arabian light crude oil was studied in the present thesis. Our results demonstrate that over a 35wt.% yield to light olefins can be achieved on spray-dried catalysts containing 1:1 mixtures of ZSM-5 and FAU zeolites. On the other hand, the nature of the selected clay, one of the key components in formulated catalysts, has a significant influence in modifying the final acidity of the composite, which, when applied in methanol to hydrocarbons, results in the propagation of either the alkene or arene cycles. The present PhD thesis also has been dedicated to the study of optimal conditions for the highly selective and stable production of aromatics during methanol to aromatics at high pressure. High selectivity to aromatics (~50%) can be achieved on a commercial high silica ZSM-5 at 400° and 30 bar total pressure. The high partial pressure of primary olefins and the promoted methanol-induced hydrogen transfer pathway result in an exponential increase in aromatization, while the high partial pressure of steam generated via dehydration of methanol leads to in situ coke removal and, therefore, to a slower deactivation of the zeolite.

Oil spills are well-known adverse anthropogenic events, as they can induce severe impacts on the environment and negative economic consequences. Still, much remains to be learned regarding the effects of crude oil exposure to aquatic organisms. The objectives of this dissertation were to fill some of those knowledge gaps by examining the effects of Deepwater Horizon (DWH) crude oil exposure on teleost kidney development and function. To this end, I analyzed how these effects translate into potential osmoregulatory impairments and investigated the interactive effects of ubiquitous natural factors, such as dissolved organic carbon (DOC) and ultraviolet (UV) light, on acute crude oil toxicity. Results demonstrated that acute early life stage (ELS) crude oil exposure induces developmental defects to the primordial kidney in teleost fish (i.e., the pronephros) as evident by alterations in: (1) transcriptional responses of key genes involved in pronephros development and function and (2) alterations in pronephros morphology. Crude oil-exposed zebrafish (Danio rerio) larvae presented defective pronephric function characterized by reduced renal clearance capacity and altered filtration selectivity, factors that likely contributed to the formation of edema. Latent osmoregulatory implications of crude oil exposure during ELS were observed in red drum (Sciaenops ocellatus) larvae, which manifested reduced survival in hypoosmotic waters, likely due to defective pronephros development and function. Finally, DOC-UV co-exposure slightly reduced acute crude oil photo-enhanced toxicity in red drum larvae. This dissertation provided novel information regarding crude oil toxicity that can be incorporated into environmental risk assessment and management for future oil spills.