Speciation of sulphur in asphaltenes and resins from Argentinian petroleum by using XANES spectroscopy

LISANDRO GIOVANETTI; MARIANA GERONÉS; MAURICIO ERBEN; YANINA BAVA; LEANDRO ANDRINI

FUEL

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2019 vol. 256 p. 115952 - 115959

0016-2361

Argentinian crude oil samples from different origins have been processed to separate in the four fractions Saturates, Aromatics, Resins, and Asphaltenes (SARA). Asphaltene and resin fractions were extracted using n-pentane and n-heptane as precipitating solvents. Sulphur contents of the samples were determined by elemental analysis and X-ray Absorption Spectroscopy at the Sulphur K-edge was used to perform sulphur speciation for resin and asphaltene fractions. Reduce sulphur as sulphides, disulphides and thiophenes dominate the spectra of asphaltenes, resins I and crude oils samples. A higher abundance of sulfoxide forms were found in the resin II fraction. In addition, it was found that the asphaltenes are more enriched in aromatic sulphur (thiophene) when the n-heptane solvent is employed. From the sulphur speciation determination it was possible to incorporate different sulphur forms in the hypothetical average molecular structures for the Argentinian asphaltenes.