Vanadium speciation in petroleum asphaltenes using XANES spectroscopies

GERONÉS, MARIANA; ANDRINI, LEANDRO; MIZRAHI, MARTÍN; ERBEN, M. F.; BAVA, YANINA B.; GIOVANETTI, LISANDRO J.

Campinas

Encuentro; Reunión Anual de Usuarios; 2019

Laboratorio Nacional Luz Sincrotrón

Petroleum asphaltenes were separated from three different Argentinian crude oils. The asphaltene fractions were extracted by precipitation employing n-heptane solvents and the coprecipitated resins were removed via Soxhlet extraction. These petroleum asphaltenes were characterized and the average molecular structure were determined by a join analysis of a wide variety of chemical tecniques.[1] Then Sulphur speciation of the samples were study by Sulphur K-edge XANES and it was possible to incorporate different sulphur forms in the hypothetical average molecular structures for the Argentinian asphaltenes. Finally, the Vanadium content were quantified by X-Ray Fluorescence and ICP mass spectrometry, shown values between 40-300 ppm for the three samples, and the speciation of Vanadium in asphaltene fractions were explored by UV-Visible absorption spectroscopy, Electron paramagnetic resonance (EPR) and XANES spectroscopies. Thus, here we present the study of Vanadium speciation in petroleum asphaltenes.