PARÂMETROS DE SOLUBILIDADE DE HILDEBRAND DOS PETRÓLEOS E DA MISTURA PETRÓLEO-HEPTANO NO LIMIAR DA PRECIPITAÇÃO DOS ASFALTENOS EMPREGANDO MICROSCOPIA ÓPTICA E ESPECTROSCOPIA DE INFRAVERMELHO-PRÓXIMO (NIR)

• Ano de defesa: 2009
• Autor(a) principal: Castro, Ariana Komura de
• Orientador(a): RAMOS, Antonio Carlos da Silva
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: Universidade Federal do Maranhão
• Programa de Pós-Graduação: PROGRAMA DE PÓS-GRADUAÇÃO EM QUÍMICA/CCET
• Departamento: QUIMICA
• País: BR
• Palavras-chave em Português: parâmetro de solubilidade de Hildebrando; parâmetro de floculação; início de precipitação; microscopia ótica; espectroscopia de infravermelho próximo
• Palavras-chave em Inglês: Hildebrand solubility parameter; flocculation parameter; onset of precipitation; optical microscopy; near-infrared spectroscopy
• Área do conhecimento CNPq: CNPQ::CIENCIAS EXATAS E DA TERRA::QUIMICA::QUIMICA ANALITICA
• Link de acesso: http://tedebc.ufma.br:8080/jspui/handle/tede/905

The Hildebrand solubility parameter is used to express the compatibility of petroleum in mixtures, starting from the principle that, independently from the system composition, the asphaltenes always precipitate in a certain solubility parameter, known as the flocculation parameter, which estimated value is 16,35 (MPa)1/2. In this paper, it was tried to experimentally determine the flocculation parameter and the solubility parameters of some petroleum, through data of onset of precipitation of asphaltenes by adding n-alkenes. The experimental determinations of onset of precipitation were performed by optical microscopy and Near-Infrared spectroscopy (NIR), in order to be also evaluated the correlation between measures. The outcomes of onset of precipitation showed a reasonable correlation among techniques, but the data obtained by NIR were generally larger. Towards the flocculation parameter, the experimental data when adjusted to a linear behavior of first order ended up on inconsistent values compared with the ones in literature, what raised doubts about the basic hypothesis of compatibility model. However, it was possible the determination of solubility parameters for several petroleum and it was noticed that the data are used successfully in prediction of compatibility in mixtures, therefore, it was verified the need of the improvement of experimental methodology to the determination of onset of precipitation through Near-Infrared spectroscopy and clues indicate that the phenomena of asphaltenes precipitation may not be only molecular.