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

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

FUEL

ELSEVIER SCI LTD

Lugar: Amsterdam; Año: 2019 vol. 256

0016-2361

Argentinian crude oil samples from different originshave been processed to separate in the four fractions Saturates, Aromatics,Resins, and Asphaltenes (SARA). Asphaltene and resin fractions were extractedusing npentane and n-heptane as precipitating solvents. Sulphur contents of thesamples were determined by elemental analysis and X-ray Absorption Spectroscopyat the Sulphur K-edge was used to perform sulphur speciation for resin andasphaltene fractions. Reduce sulphur as sulphides, disulphides and thiophenesdominate the spectra of asphaltenes, resins I and crude oils samples. A higherabundance 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 speciationdetermination it was possible to incorporate different sulphur forms in thehypothetical average molecular structures for the Argentinian asphaltenes.