CEQUINOR   05415
CENTRO DE QUIMICA INORGANICA "DR. PEDRO J. AYMONINO"
Unidad Ejecutora - UE
congresos y reuniones científicas
Título:
CARACTERIZACION DE ASFALTENOS Y RESINAS Especiación del Azufre
Autor/es:
ERBEN, M.F; BAVA, YANINA B.; GERONÉS, MARIANA
Reunión:
Congreso; 7mo congreso produccion y desarrollo de reservas; 2019
Institución organizadora:
instituto argentino del petroleo y el gas
Resumen:
Petroleum asphaltenes and resins were separated from three different Argentinian crude oils. The asphaltene fractions were extracted by precipitation employing n-pentane and n-heptane solvents and the coprecipitated resins were removed via Soxhlet extraction. The asphaltenes were characterized by elemental analysis, thermogravimetric analysis (TGA), laser desorption ionization mass spectrometry (LDI-MS), Fourier-transform infrared spectroscopy (FTIR), proton nuclear magnetic resonance (1H-RMN), powder X-Ray diffraction (XRD) and Raman spectroscopy. It was found that the asphaltene fractions present both, a higher content of heteroatoms and a major degree of aromaticity, when n-heptane is employed. Average structural parameters were obtained by a comprehensive analysis of the experimental data, including those describing the central polycyclic aromatic hydrocarbons (PAHs) core and lateral chains. Thus, a hypothetical average molecular structure is proposed for the Argentinian asphaltenes. The average model molecules have nucleus of PAHs arranged as pericondensed systems of 4-6 fused aromatic rings, with naphthenic groups and/or alkyl chains of 5-10 carbon long attached. In addition, X ray Absorption Spectroscopy at the Sulphur K-edge was used to perform sulphur speciation for resin and asphaltene fractions. Reduce sulphur as sulphides, disulfides and thiophenes dominate the spectra of asphaltenes, resins I and crude oils samples. A higher abundance of sulfoxide forms were found in the resins II fractions. 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.