Estudo de resinas e asfaltenos em petróleos brasileiros por ressonância magnética nuclear

• Ano de defesa: 2016
• Autor(a) principal: Mendonça, Janur
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Espírito Santo; BR; Mestrado em Química; Centro de Ciências Exatas; UFES; Programa de Pós-Graduação em Química
• Palavras-chave em Português: Asphaltene; Resin; Agregation; Ressonância magnética nuclear; Asfalteno; Resinas; Agregação; Gomas e resinas; Química; 54
• Link de acesso: http://repositorio.ufes.br/handle/10/7326

Heavy crude oils has been gaining prominence among the refineries interest worldwide. Thus, asphaltenes, known for their low reactivity and high molecular weight, have received particular attention in recent decades due to the problems they cause during the oil processing. Another class of compounds that have received special attention are the resins, which are responsible forthe stability of the asphaltenes in crude oil. The 1H and 13C NMR spectroscopy has been used very successfully in the oil analysis and characterization of the types of hydrocarbons components. Modern 1H NMR analysis can provide relevant information about the aromatic and aliphatic hydrogen content, also can infer the size of the aliphatic chain and substituent groups. As a complement, 13C NMR spectroscopy obtains information regarding the carbon chain, such as quaternary carbon information, which is not achieved by 1H NMR, enabling to relate the hydrogens structure with carbon skeleton.Through the parameters obtained by 1H and 13C NMR, this study propose a procedure for the extraction and separation of asphaltenes and resins from the crude oil, characterization by 1H and 13C NMR spectroscopy of the asphaltenes and resins to define their structural parameters and relate to the stability of the crude oil.The samples characterization was performed by using 1H and 13C NMR particular spectra regions that allow to identify and quantify the aromatic and aliphatic hydrogens and carbons.The resultsfrom 1H NMR aromatic integration regions analysisshowed a greater value for ASF_3 sample when compared to the other samples. This sample has also showed a greater aliphatic hydrogen content in alpha position among the others samples. Therefore, resins presented very similar results not allowing to differentiate one sample from the other.From all samples studied, AM_3 is considered unstable, the deviation presented by the asphaltene sample ASF_3 allow us to relate to the stability, where there is a relation between the increase of the content of aromatic hydrogens an also a decrease of the content of aliphatic hydrogens in the alpha position.