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Estatística
Título: CHARACTERIZATION OF PARAFFIN WAXES IN BRAZILIAN CRUDE OILS AND THEIR CORRELATION WITH WATER-IN-OIL EMULSIONS
Autor: VITORIA REGIA MOISES NUNES GOMES
Colaborador(es): ANA MARIA PERCEBOM SETTE DA SILVA - Orientador
LINA ROCIO MORANTES PERICO - Coorientador
Catalogação: 05/SET/2024 Língua(s): PORTUGUESE - BRAZIL
Tipo: TEXT Subtipo: THESIS
Notas: [pt] Todos os dados constantes dos documentos são de inteira responsabilidade de seus autores. Os dados utilizados nas descrições dos documentos estão em conformidade com os sistemas da administração da PUC-Rio.
[en] All data contained in the documents are the sole responsibility of the authors. The data used in the descriptions of the documents are in conformity with the systems of the administration of PUC-Rio.
Referência(s): [pt] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=67870&idi=1
[en] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=67870&idi=2
DOI: https://doi.org/10.17771/PUCRio.acad.67870
Resumo:
The appearance of emulsions has generated vast operational and economic challenges for the oil industry, mainly in separating the oil, and water fractions in the separator vessel of the produced fluid. Several previous studies suggest that asphaltenes are responsible for forming and stabilizing petroleum emulsions. However, with the discovery of the Pre-Salt, the formation of stable emulsions has been observed even from crude oils with a low asphaltene content, suggesting that other fractions of the crude oil play an important role in these emulsions. The literature review of this work showed different applications in which paraffin waxes can act as Pickering particles or gel networks that stabilize emulsions. Thus, the hypothesis arises that they also have a relevant role in the stabilization of petroleum emulsions. This study aimed to evaluate the capacity for the formation and stabilization of water-in-oil (W/O) emulsions by petroleum paraffin waxes and their possible interaction with other fractions with interfacial activity. To achieve this, the first part of the work involved the extraction of paraffin waxes from Brazilian crude oils and the analysis of their chemical composition and their respective crude oils. The second part consisted of the characterization of emulsions formed by crude oils, residual oils from the extraction of asphaltenes, or residual oils from the extraction of paraffin waxes. Finally, the third part involved the preparation of model emulsions considering the solubility of the oil components to identify the petroleum fractions that form and stabilize the emulsions. The results indicated that the removal of asphaltenes increased the stability of the emulsion, while the removal of waxes drastically decreased it. On the other hand, paraffin waxes alone are not sufficient to promote the formation of the emulsion, requiring their combination with other amphiphilic components other than asphaltenes. Small-angle X-ray scattering (SAXS) analysis revealed that the waxes only formed a lamellar structure when highly purified, which is very far from the complex mixture that is crude oil. Therefore, paraffin waxes probably do not form a gel network to stabilize emulsions, but rather form crystalline particles that promote Pickering stabilization. In conclusion, the model emulsions correlated well with the results from real samples thanks to the choice of components and solvents to simulate crude oil emulsions. This correlation indicated that polar petroleum fractions other than asphaltenes play a crucial role in the formation of emulsions, while paraffin wax provides stabilization by the Pickering mechanism. Therefore, this study increases understanding of the mechanisms that govern paraffinic Brazilian crude oil emulsions.
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