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Estatística
Título: EFFECT OF KEROSENE ON INTERFACIAL PROPERTIES AND EMULSION STABILITY OF A BRAZILIAN HEAVY OIL
Autor: LINA MERCEDES DAZA BARRANCO
Colaborador(es): AURORA PEREZ GRAMATGES - Orientador
ANGELA CAMILA PINTO DUNCKE - Coorientador
Catalogação: 02/OUT/2023 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=64186&idi=1
[en] https://www.maxwell.vrac.puc-rio.br/projetosEspeciais/ETDs/consultas/conteudo.php?strSecao=resultado&nrSeq=64186&idi=2
DOI: https://doi.org/10.17771/PUCRio.acad.64186
Resumo:
The high viscosity of heavy oils and the high content of asphaltenes contribute to the formation of highly stable water-in-heavy oil (W/O) emulsions, making oil/water separation difficult and increasing production and transportation costs. To reduce viscosity, dilution techniques with simple solvents are common. Therefore, slight research has been conducted on the impact of aromatic compounds on interfacial properties and emulsion stability from complex solvents, such as kerosene. In this study, we investigated the effect of segregation of aromatic compounds in kerosene on the bulk and interfacial properties and stability of asphaltenes and W/O emulsions. Furthermore, we analyzed the correlations of these effects with chemical demulsification. Initially, we evaluated the interfacial properties of natural surfactants fractions extracted from Brazilian heavy oil regarding their ability to stabilize water-kerosene emulsions. The results indicated that the stability of these emulsions was related to the synergistic effect between resins and asphaltenes, resulting in the formation of more flexible interfacial films that prevent or delay the coalescence of the droplets. However, when kerosene was used as diluent of heavy oil (HO) in the oil phase, flocculation and precipitation of asphaltenes were observed. These results were correlated with the chemical composition of two kerosene types: one composed only of saturates (KeS) and another containing saturates and 30 percent wt. of aromatic compounds (KeSA). It was found that the chemical composition of the kerosene affects the colloidal asphaltenes stability, emulsion stability, and interfacial properties. KeSA showed greater solubilization and dispersion of asphaltenes compared to KeS. Additionally, interfacial viscoelasticity decreased when the kerosene content was bigger or equal 30 wt. percent, indicating the formation of less rigid interfacial films. However, the interfacial elastic modulus in systems containing KeSA gradually increased over time, suggesting better solubility of asphaltenes and diffusion-controlled adsorption at the interface. The concentration of solvent aromatics (KeSA) maintains interfacial film stability during HO dilution, thus compensating for the loss of asphaltenes with increasing kerosene content in the oil phase. The results also revealed the crucial role of kerosene s aromaticity in the breaking of W/O emulsions containing 20 wt. percent of kerosene in the oil phase. Various chemical demulsifiers commonly used as bases for commercial demulsifiers, as well as model compounds, were tested. The presence of KeSA exhibited greater robustness and resistance to emulsion breaking. This effect was attributed to interfacial segregation of aromatic compounds from kerosene. These results emphasize the importance of kerosene s chemical composition when used for diluting heavy oils, as it has a significant effect on the stability and breaking of W/O emulsions, particularly in the case of the Brazilian heavy oil used in this study.
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