Chemical speciation of Sulphur in petroleum asphaltenes using XANES spectroscopy

BAVA, YANINA; GIOVANETTI, LISANDRO; ANDRINI, LEANDRO; GERONES M.; ERBEN, MAURICIO FEDERICO

Congreso; XXVII Reunión Anual de Usuarios; 2017

LNLS

Asphaltenes are complex mixture of heteroatom rich aromatic hydrocarbons that are present as a solid suspension in crude oils. The asphaltenes are the fraction of oil insoluble in heptane (or n-alkanes) but soluble in toluene and the most probable composition are a complex mixtures of polycyclic aromatic hydrocarbons groups (PAHs) with substituted alkyl chains bearing heteroatoms functional groups. Sulphur is the most abundant heteroatom in the oil, present in the heavier fractions. Thus, the knowledge of the Sulphur chemistry in petroleum helps in the mitigation of Sulphur induced problems in resource utilization. Sulphur speciation varies greatly in asphaltenes from different locations representing different source and reservoir rocks. The XANES spectroscopy is an appropriated technique for the speciation of chemical species and provide qualitative and quantitative information about the Sulphur chemistry in asphaltenes. In this work, the asphaltene fraction obtained from different crude oils from Argentinean petroleum were subject to evaluation of the sulpuhr speciation by using XANES spectroscopy.