CHANGES ON EXTRA-HEAVY CRUDE OIL ASPHALTENE PROPERTIES MODIFICATED WITH Fe IN HYDROTREATING

Miguel A. Luis,* Juan C. Pereira** and Sandra P. Cubillos*`**

*Laboratorio de Catálisis y Metales de Transición

**Laboratorio de Petróleo, Hidrocarburos y Derivados

Departamento de Química., Facultad Experimental de Ciencias y Tecnología, Universidad de Carabobo.Valencia, Edo. Carabobo,  Venezuela, Apartado  código 3336.

E-mail of the author: mluis@uc.edu.ve

The study recent asphaltene has as intention the asphaltenes properties modification of crude extra-heavy Hamaca (AsfH) of Orinoco Belt, for its evaluation in hydrotreating (HDT); with the purpose of contributing alternative routes for the improvement of crude extra-heavy.

Firstly, it was come to the insertion of the iron, in the asphaltene using for it an iron salt. In order to characterize the modified solid, it used UV-visible spectroscopy and nuclear magnetic proton resonance (¹H NMR).

Asphaltene samples set were used: Hamaca asphaltene (AsfH) (pattern), asphaltene with iron insertion (AsfH-Fe), and mixes mechanics of asphaltene with synthesized iron catalyst pyrrotite type (AsfH-Fe₇S₈). These samples were put under hydrotreating to 200 ºC, atmospheric pressure and a flow of feeding of 10.5 mL/H in a reactor of fixed bed. All the samples were evaluated, before and after being hydrotreated, by ¹H NMR, total sulfur analysis and determination of molecular weight average by VPO. The reactivity was followed by gas chromatography (CG). The obtained results suggest the iron is in the asphaltene`s structure (inserted), somehow affecting the chemical atmosphere of the same one to the being submissive HDT.

Even at lower temperatures to the reported ones in Literature, the obtained results show changes in the asphaltenes properties in terms of structural parameters observed traverse of ¹H-NMR and VPO, where the increase of the molecular weight average for AsfH-Fe showed a significant increase with respect to the others. In addition, reduction in the sulfur content was observed, after being hydrotreated.