Most crude oils contain traces of vanadyl porphyrins within their asphaltene fraction. Although these metals are only present in trace quantities, they have a significant detrimental impact on crude oil processing units; therefore, their selective removal is highly desirable. The current work studied the interaction of these vanadyl porphyrins with asphaltenes using two approaches: 1) equilibrium solubility measurements of model porphyrins and 2) membrane diffusion measurements in dilute solution. Solubility measurements with model porphyrins showed that simple model porphyrins fit the operational definition for asphaltenes, exhibiting negligible solubility in n-heptane and orders of magnitude higher solubility in toluene. Measurement of the melting point properties enabled modeling of their solubility behaviour and showed that simple models incorporating solubility parameters (Regular solution and Flory-Huggins) were not capable of describing the observed behaviour. Diffusion measurements were done using model vanadyl porphyrins, asphaltenes, and petroporphyrins in toluene using a stirred diffusion cell equipped with ultrafiltration membranes (Ultracel YM and Anopore). The pore sizes were varied between 3-20 nm to retain aggregates while allowing free molecules to diffuse. The permeate was continuously monitored using in situ UV/Visible spectroscopy. These experiments determined that the size of the asphaltene aggregates at 1 g/L in toluene at 25C were in the range of 5-9 nm. An increase in temperature results in an increase in asphaltene mobility but does not reduce the size of the asphaltene structures below 5 nm. Likewise, a decrease in concentration to 0.1 g/L did not result in a decrease in size. It was also observed that the exclusion of a large portion of the total asphaltenes by pores < 5 nm eliminates the absorbance of visible light (>600 nm) indicating the presence of Rayleigh scattering for the aggregated species in solution. The petroporphyrins are larger than the model vanadyl porphyrins as indicated by pore hindrance effects within smaller pores. An increase in temperature results in an increase in petroporphyrin mobility, although decreasing the asphaltene concentration does not. The mobility of the vanadyl petroporphyrins is affected by the origin of the sample (Safaniya, Venezuela, Athabasca) and is therefore not universal. / Chemical Engineering

Orientador: Fábio Cesar Gozzo / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-26T16:09:31Z (GMT). No. of bitstreams: 1 Koolen_HectorHenriqueFerreira_D.pdf: 16550075 bytes, checksum: 0fafb8ced0640f9080c108d7cb303ac4 (MD5) Previous issue date: 2015 / Resumo: A espectrometria de massas (MS) consiste no estudo de íons na fase gasosa. O grande salto na utilização da MS devido ao desenvolvimento dos métodos de ionização por eletrospray (ESI), por J. B. Fenn e ionização/dessorção a laser auxiliada por matriz (MALDI) por M. Karas e F. Hillenkamp no final da década de 80 abriu espaço para o desenvolvimento de novos equipamentos, desta forma expandindo em muito a capacidade de análise de diversos analitos. Misturas complexas constituem um desafio até hoje, onde diversas técnicas são empregadas com o objetivo de se entender a constituição destas matrizes. Neste contexto a MS vêm sendo utilizada em conjunto com a mobilidade iônica (IM) em estudos com diversos analitos, como por exemplo, em proteômica e petroleômica. Este trabalho é constituído por dois capítulos, onde na primeira parte as técnicas foram utilizadas em experimentos de proteômica estrutural por meio de ligação cruzada. Estudos Fundamentais foram conduzidos de modo a serem exploradas as misturas complexas de peptídeos provenientes de experimentos utilizando-se uma classe pouco explorada de reagentes de ligação cruzada (imidoésteres). Para o segundo capítulo a mesmas técnicas foram utilizadas nas análises da fração pesada (asfaltenos) de petróleos brasileiros. A simplificação das amostras juntamente com a caracterização estrutural destes compostos por meio de suas sessões de choque de colisão (CCS) constituiu a estratégia de análise para este capítulo. Como resultados da primeira parte têm-se o estabelecimento das rotas de fragmentação de peptídeos modificados pelo reagente de ligação cruzada dimetil suberoimidato e a aplicação do mesmo em experimentos com sistemas proteicos reais. A IM foi aplicada de modo a se separar as espécies geradas após os experimentos reacionais dos peptídeos não modificados por meio de seus estados de carga o que possibilitou, uma rápida e simplificação deste tipo de mistura. Como resultados da segunda parte desta tese a IM foi empregada na caracterização das CCS de compostos modelo de asfaltenos e posteriormente em íons representativos da fração pesada. Os resultados foram validados mediante cálculos teóricos e espectrometria de massas de ultra-alta resolução. Os dados obtidos vão de encontro com os modelos de estruturas de arquitetura do tipo ilha previstos no modelo de Yen-Mullins, constituindo desta forma o primeiro estudo estrutural de asfaltenos usando-se estas técnicas combinadas / Abstract: Mass spectrometry (MS) constitutes the study of ions in the gas-phase, being the structural elucidation the main application of MS. With the development of ionization techniques such as electrospray (ESI), by J. B. Fenn and matrix assisted laser desorption by M. Karas and F. Hillenkamp in the later 80¿s allowed the development of new instruments, providing an expansion of the array of analytes suitable for MS analysis. Complex mixtures constitute a challenge nowadays, where diverse techniques are employed with the objective of understanding the chemical composition of such matrixes. In this sense MS have been used along with ion mobility (IM) in the study of different analytes (e.g. in Proteomics and Petroleomics). This works comprises two chapters, where in the first one the techniques were applied in structural proteomics by means of chemical cross-linking experiments. Fundamental studies were carried to explore complex mixtures of tryptic peptides after experiments with imidoesters reagents. For the second chapter the same techniques were applied in the analysis of the polar fraction of Brazilian petroleum¿s (asphaltenes), where beyond separations an structural study was carried out to verify the existing models regarding asphaltene structure. As results of the chapter 1 the behavior at the gas-phase of the peptides upon dissociation techniques was elucidated (fragmentation studies). The validation of imidates as cross-linking reagents was performed to real proteins. IM was applied to separate different charge states created by the modified peptides generated by the imidate reagent. As results from the second chapter IM was successfully applied, were the comparison with model compounds was done employing also other MS techniques such as ultra-high resolution (UHR) MS. The findings of this chapter reinforce the Yen-Mullins model that describes asphaltenes as compounds possessing island structures / Doutorado / Quimica Organica / Doutor em Ciências

Organoclays modelling the Athabasca oil sands were prepared in heptane and toluene showing indole loading occurring exclusively on the external surface of the clay, via a multilayer adsorption mechanism. Solvent adsorption was minimal. Vermicular microstructures, similar to natural kaolinite were formed. Isotherms were constructed and fitted to the BET equation, giving monolayer quantities (9.28mg) that matched well to the theoretical amount calculated from surface area measurements (8.87mg). Dispersing the organoclays in isopropanol and in toluene left a monolayer equivalent. Using cellulose as a competitive desorption agent in asphaltene based organoclay dispersions achieved complete disaggregation of the dispersed organoclay stacks.13 C CP - MAS NMR, showed up to a 25% increase in desorption for aliphatic and up to 40% increase in desorption for aromatic functionalities of the loaded organic matter. Investigation of other saccharides and modified celluloses as competitive agents is recommended for future work.

Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2016-08-05T13:14:47Z No. of bitstreams: 2 Dissertação - Verônica Vale Carvalho - 2016.pdf: 3350706 bytes, checksum: a2b65a96388e547cf16aa0fd45a20f7f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-08-05T13:17:53Z (GMT) No. of bitstreams: 2 Dissertação - Verônica Vale Carvalho - 2016.pdf: 3350706 bytes, checksum: a2b65a96388e547cf16aa0fd45a20f7f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2016-08-05T13:17:53Z (GMT). No. of bitstreams: 2 Dissertação - Verônica Vale Carvalho - 2016.pdf: 3350706 bytes, checksum: a2b65a96388e547cf16aa0fd45a20f7f (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2016-07-25 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Heavy oil fractions studies are of great importance for the oil industry, receiving special attention in recent decades due to the interest to meet them in order to obtain compounds with higher added value derived from this. Moreover, these studies also aim solutions to the problems caused by these fractions during all processing steps oil. Asphaltenes in NMP produces two fractions, a soluble and the other insoluble in NMP. It was suggested that the NI fraction present low content of aromatic compounds, opening a new debate on the composition of asphaltenes which are widely discussed in the literature as aromatic and polar compounds. In the present work is the chemical study of these asphaltenes fractions by mass spectrometry of high resolution mass and accuracy, making use of the resonance cyclotron Ion Fourier Transform (FT-ICR MS) associated with the source of atmospheric pressure ionization - ESI (electrospray ionization), infrared, fluorescence and 1H NMR. The infrared analysis, 1H NMR and Fluorescence made it possible to observe differences among samples, where NS fraction had higher amounts of heteroatoms present and a higher percentage of aromatic hydrogens and NI fraction is nonpolar in the presence of increasing amounts of alkyl and naphthenic hydrocarbons. The results of FT-ICR MS corroborated with the other results, showing that the NS fractions showed high proportion of heteroatomics species and higher DBE values compared NI fractions exhibited predominantly hydrocarbon compounds and derisory amounts of heteroatoms and also insignificant quantities compounds of DBE values different from zero. / Os estudos das frações pesadas do petróleo são de grande importância para a indústria petrolífera, recebendo atenção especial nas últimas décadas devido ao interesse em conhecê-las visando a obtenção de compostos com maior valor agregado oriundos desta. Por outro lado, estes estudos também objetivam soluções para os problemas causados por essas frações durante todas as etapas de processamento do petróleo. Os asfaltenos em NMP produzem duas frações, uma solúvel e outra insolúvel em NMP. Foi sugerido que a fração NI apresente baixo teor de compostos aromáticos, abrindo um novo debate sobre a composição dos asfaltenos que são largamente discutidos na literatura como compostos aromáticos e polares. No presente trabalho realizou-se o estudo químico destas frações de asfaltenos por espectrometria de massas de altíssima resolução e exatidão, fazendo uso da Ressonância Ciclotrônica de Íons com Transformada de Fourier, (FT-ICR MS) associada com a fonte de ionização a pressão atmosférica – ESI (ionização por electrospray), infravermelho, fluorescência e RMN de 1H. As análises de infravermelho, RMN de 1H e fluorescência, possibilitaram observar as diferenças existentes entre as amostras, onde a fração NS apresentou maiores quantidades de heteroátomos presentes e maior porcentagem de hidrogênios aromáticos e a fração NI se mostrou apolar com a presença de maiores quantidades de hidrocarbonetos alquílicos e naftênicos. Os resultados de FT-ICR MS corroboraram com os demais resultados, evidenciando que, as frações NS apresentaram elevada proporção de espécies heteroatômicas e maiores valores de DBE quando comparadas as frações NI que exibiram predominância de compostos hidrocarbonetos e quantidades irrisórias de heteroátomos e também quantidades insignificantes de compostos com valores de DBE diferentes de zero.

Reservoir fluids are rarely found in homogeneous structures having homogeneous properties. The various elements and processes of the petroleum system result in complex fluid distributions and compositions. A sound understanding of these complexities can avoid disappointing results and costly mistakes when designing the completion and production of the reservoir. The earlier these complexities are understood in the exploration phase, the better are the chances of a successful decision making process in the design phase of the project. Assessing reservoir compartment connectivity is of paramount importance for a optimal field development. Recent technological advances in wireline formation testing and sampling provide asset teams with a new methodology to evaluate in situ fluid properties and reservoir connectivity. After a review of the technology of downhole fluid analysis (DFA), the currently available methods of modeling equilibrated fluid gradients are presented. Fluid composition equilibrium is a stationary state where all components have reached zero mass flux. A reservoir model is designed to simulate numerically equilibration processes over geologic timescales at isothermal conditions where diffusion and gravity are the active mechanisms. A variety of initial conditions and reservoir fluid types is considered. Non-equilibrium fluid gradients and their transient behavior as they evolve towards fluid composition equilibrium are the main interest of this study. The results are compared in case studies, that are available in published literature. The modeling methods allow modeling of vertical and lateral fluid gradients. After a discussion of the cases, this thesis gives recommendations on 1) what fluid properties should be assessed and 2) how many data points are needed to reduce the chance of misinterpretation of non-equilibrium gradients in the presence of faults. To make best use DFA data, the property that exhibits the largest gradient needs to be investigated, as it yields the greatest potential to assess connectivity. The shape of the distribution of fluid composition within a compartment is found to be an important part in investigating reservoir connectivity. During data acquisition efforts should be made to acquire enough data points to reveal this shape. In combination with the presented techniques to identify non-equilibrium conditions, this will optimize DFA data acquisition and maximize the value of the data.

No description available.

Athabasca asphaltenes were characterized using small-angle X-ray scattering (SAXS) with synchrotron radiation. Two methods were used to separate asphaltenes from Athabasca bitumen. Conventional chemical separation by precipitation with n-pentane, and physical separation realized by passing bitumen through a zirconia membrane with a 20 nm average pore size. The Athabasca permeates and chemically separated samples were dispersed in 1-methylnaphtalene and n-dodecane, with temperature and asphaltene concentration ranges of 50-310 C and 1-8 wt. %, respectively. Two approaches were also taken in the analysis of the SAXS emissions. A model-independent approach provided radii of gyration and scattering coefficients. A model-dependent fit provided size distributions for asphaltenes aggregates assuming that they are dense and spherical. Physically and chemically separated asphaltenes showed significant differences in nominal size and structure, and their structural properties exhibited different temperature dependencies. The results challenge the merits of using chemically separated asphaltene properties as a basis for asphaltene property prediction in crude oil/bitumen.

Orientadores: Maria Regina Wolf Maciel, Rubens Maciel Filho / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Quimica / Made available in DSpace on 2018-08-14T19:21:50Z (GMT). No. of bitstreams: 1 Quirino_FilipeAugustoBarral_M.pdf: 2305218 bytes, checksum: 4442e2951234a27e439a18c7f1fcd9d6 (MD5) Previous issue date: 2009 / Resumo: A desasfaltação do petróleo é um dos principais processos primários no refino de óleo cru. O estudo do processo de desasfaltação tem merecido atenção considerável nas últimas décadas, devido ao aumento das reservas de óleos crus pesados. No Brasil, grande parte das reservas exploradas produz óleos pesados, uma vez que a crescente redução no processamento de petróleos leves aliada à crescente demanda por combustíveis e lubrificantes de melhor qualidade força a indústria nacional de petróleo a desenvolver processos novos e mais eficientes para o refino do petróleo e seus resíduos. Os asfaltenos, encontrados em grande quantidade nos petróleos pesados, devem ser removidos do óleo de modo a se obter rendimentos mais altos no processo de craqueamento catalítico e produzir um óleo desasfaltado (DAO) mais leve. A extração de asfaltenos de um resíduo de petróleo com fluido supercrítico apresenta-se como uma alternativa viável para o processo de desasfaltação de resíduo de vácuo na produção de óleo lubrificante. Neste trabalho, foi estudado um processo de desasfaltação de petróleo pesado através da extração com fluido supercrítico. Toda a problemática do equilíbrio de fases do sistema foi avaliada através da construção computacional de diagramas de fases ternários para a mistura asfalto-óleosolvente. Foi selecionado um modelo termodinâmico capaz de predizer o equilíbrio de fases na desasfaltação para as condições supercríticas do solvente. Uma unidade de desasfaltação a propano foi simulada através de simulador comercial de processos, a fim de remover asfaltenos, resinas e demais componentes pesados de um óleo cru. Simulações foram realizadas considerando processo de extração líquido-líquido e separação supercrítica. Uma análise de sensitividade foi conduzida de modo a avaliar a influência das principais variáveis operacionais no processo. A eficiência da extração e a qualidade dos produtos foram verificadas com variações sistemáticas em variáveis independentes, de modo a obter rendimentos mais elevados na remoção de asfaltenos e recuperação de frações leves, visando a otimização do processo. O estabelecimento desta plataforma de simulação e os resultados obtidos foram de fundamental importância, por não serem facilmente encontrados na literatura aberta. A avaliação computacional da planta de desasfaltação servirá de base para o projeto e operação de planta piloto, a qual validará os dados obtidos. / Abstract: Petroleum deasphalting is one of the major primary processes in crude oil refining. The study of deasphalting has gained considerable attention in the last few decades due to the increase in heavy crude oil reserves. In Brazil, the majority of the explored reserves produce heavy oils. The increasing reduction in the processing of light oils, added to the increasing demand for fuels and lube oils of better quality, force the Brazilian oil industry to develop new and upgraded processes for the refining of crude oil and their residues. Asphaltenes, which are found in large amount in heavy oils, must be removed from the oil in order to get higher yields in the fluid catalytic cracking process (FCC) and to produce lighter deasphalted oil (DAO). The extraction of asphaltenes from petroleum residues though supercritical fluid is presented as a viable alternative for the vacuum-residue deasphalting, in the lube oil production. In this work, a deasphalting process of heavy crude oil through supercritical fluid extraction was studied. All the problematic of the system phase equilibrium was evaluated through the computational construction of phase ternary diagrams for the asphalt-oil-solvent mixture. A thermodynamic model capable to predict the phase behavior in the deasphalting process for the supercritical conditions of the solvent was selected. A propane deasphalting unit was simulated using a commercial process simulator, in order to remove asphaltenes, resins and heavy components from the crude. Simulations were carried out considering liquid-liquid extraction and supercritical separation. A sensitivity analysis was carried out in order to evaluate the influence of the main operational variables on this process. The efficiency of the extraction and the product quality was verified with systematic variations in the independent variables, in order to obtain higher yields in asphaltene removal and in light oil fractions recovery, aiming the process optimization. The establishment of this kind of simulation as well as the obtained results was very important because they are not easily found in the open literature. The computational evaluation of the deasphalting plant will serve as basis for operation and design of a pilot plant, which can validate the simulation data. / Mestrado / Desenvolvimento de Processos Químicos / Mestre em Engenharia Química

Made available in DSpace on 2016-08-19T12:56:36Z (GMT). No. of bitstreams: 1 Leydy Daiana Frazao da Silva.pdf: 3169054 bytes, checksum: 7722a9e052abaed32aab639ad8ea0af9 (MD5) Previous issue date: 2011-04-08 / Oil is a complex mixture whose composition and properties vary according to their origin and composition. Changes in pressure and temperature during production operations and processing can compromise the phase equilibrium of this mixture, resulting in the formation of solid precipitates. The deposition of these fractions can cause blockage of the reservoir and the drainage ducts causing damage to equipment and interfere with the quality of oil produced. Among the major heavy fractions with potential for the formation of deposits are asphaltenes. To treat this problem of asphaltene deposition is necessary to know more about their behavior in different oil samples. To obtain information of these precipitates Near Infrared spectroscopy coupled with Fourier transform was used to determine the onset of asphaltene precipitation in Brazilian petroleum, then these values beginning of precipitation were used to calculate the solubility parameters of the samples, the use of near infrared targets the improvement in the experimental determination of the start point of asphaltene precipitation obtained previously by optical microscopy. The results of solubility parameter obtained by the two techniques were compared. / O petróleo é como uma mistura complexa cuja composição e propriedades variam conforme a sua origem e composição. A deposição dos asfaltenos, frações pesadas do petróleo, durante a prospecção, transporte e processamento são indesejáveis devido aos enormes prejuízos que podem causar. Para compreender o problema de deposição dos asfaltenos é necessário o conhecimento melhor sobre seu comportamento nas diferentes amostras de petróleo. Visando obter mais informações desses precipitados, a Espectroscopia de Infravermelho Próximo acoplada à transformada de Fourier foi utilizada para determinar o ponto de início de precipitação (IP) dos asfaltenos em petróleos brasileiros. Posteriormente, esses valores de inicio de precipitação foram usados para calcular os parâmetros de solubilidade das amostras analisadas. A utilização do infravermelho próximo visa o aprimoramento na determinação experimental do ponto de início de precipitação dos asfaltenos, até então obtido por microscopia óptica. Os resultados mostraram que o ponto de início de precipitação e o parâmetro de solubilidade podem ser obtidos utilizando todo o espectro completo de absorbância, ao invés de utilizar apenas os dados do comprimento de onda de 1600 nm, usualmente empregado na literatura.

Orientadores: Watson Loh, Edvaldo Sabadini / Tese (doutorado) - Universidade Estadual de Campinas, Instituto de Química / Made available in DSpace on 2018-08-24T08:19:42Z (GMT). No. of bitstreams: 1 Padula_Lilian_D.pdf: 2979563 bytes, checksum: 326395f8133ab39db6f41ffbeff5d688 (MD5) Previous issue date: 2013 / Resumo: Esta tese envolve o estudo da origem da alta viscosidade de dois óleos pesados brasileiros, OF1 e OF2, utilizando, para isso, aditivos químicos e tratamentos físicos. Através deste estudo confirmou-se o papel importante dos asfaltenos na viscosidade dos óleos aqui estudados. Investigações com espalhamento de raios-X em baixo ângulo (SAXS) indicaram a presença de agregados nestes óleosos quais apresentam uma agregação sequencial e hierarquizada. Além disso, estudou-se o que exercia um papel mais marcante sobre a viscosidade, o tamanho dos agregados ou a concentração dos mesmos. Verificou-se então que a concentração de agregados é o que apresenta maior efeito sobre a viscosidade dos óleos, uma vez que óleos com diferentes viscosidades 300.000 e 30.000 mPas apresentaram tamanho de agregados muito próximos,maior que 41 e 43 nm. No entanto, asconcentrações de asfalteno C5I eram bem diferentes para OF2s e OF1s, 14 e 20 % respectivamente, sendo mais viscosos aqueles com maior concentração de asfaltenos. O estudo com aditivos de diferentes classes mostrou que os mesmos não promoviam redução da viscosidade superior a 40 %. Além disso, mesmo os aditivos que causaram redução de 40 % na viscosidade não demonstraram nenhum efeito na microestrutura dos óleosquando avaliados por SAXS. Devido a esses resultados, propôs-se um modelobaseado no modelo desuspensão coloidal no qual os aditivos atuam sobre a fase contínua, em um efeito similar ao de diluição, não promovendo alterações nos agregados de asfaltenos na faixa de concentração estudada. Portanto, não faria sentido pensar em aditivos que em pequenas concentrações reduzam drasticamente a viscosidade / Abstract: Investigation of the elevated viscosity of two Brazilian heavy oils, OF1 and OF2, using several classes of additives and physical treatments. The studyreinforced the asphaltenes role on heavy oils viscosity. And SAXS investigationshave shown the presence of aggregates in these oils which aggregates in asequential and hierarchized. Furthermore showed also that, the concentration has a major contribution than the size of aggregates, because crudes with very different viscosities 300.000 and 30.000 mPas presented very similar aggregates sizes, 41 and 43 nm, but concentrations of asphaltene I5 quite different 14 and 20% respectively. Studying the rheology of several classes of additives the maximum viscosity reduction promoted was 40% of the initial value for heavy oils OF1s and OF2s presented. Also, the additives did not promote changes on the microstructure of asphaltene aggregates; therefore, a hypothesis having in mind petroleum as a colloidal suspension was formulated. This hypothesis states that the additives act only on the continuous medium, not on the aggregates themselves, similarly to a dilution effect. Therefore, it is very unlikely to find an additive that can be used as viscosity reducer through asphaltene disaggregation on heavy oils, at least on the additive concentration range studied here / Doutorado / Físico-Química / Doutora em Ciências