Abstract

AFANASJEVA, Natalia. Pyrolytic conversion of resin-asphaltene concentrates from heavy oils. Rev. ion [online]. 2014, vol.27, n.2, pp.71-86. ISSN 0120-100X.

Crude refining has become complicated due to depletion of light oil and need of heavier fraction to attend the growing demand in energy. The main problem is the handling of these fractions with high content of asphaltenes and resin concentrates. This research deals with the physicochemical characteristics of resin-asphaltenes concentrates obtained from different Colombian heavy oils in order to evaluate their potential in a process of mild pyrolysis in inert atmosphere to obtain aggregated value liquid products. Resin asphaltene concentrates (CRA) were obtained by precipitation and then the pure asphaltene isolated and purified. Asphaltene content in Castilla crude: 21%, San Fernando crude: 19% and from Rubiales crude: 13%. Thermal conversion by TGA for the same asphaltenes resulted in 30, 35 and 40% yield of coke. Elemental analysis, heat content, proximate analysis and empiric formula are given for the concentrate and the obtained coke. Pyrolysis was done in a lab batch reactor under temperatures 330 - 470°C. Three fractions were obtained: gas, liquid and solid. All fractions were characterized by mean of different spectroscopic techniques (C+H+N, S+O, FT-IR, RMN ¹H y ¹³C) and chromatography (HPLC, GC and GC-MS). At higher temperatures yield of gas and solid fraction increased. Maximum yield of liquid fraction was obtained at 450°C. Potential conversion of asphaltenes in added value products as raw fuels is ~26% (dry basis). Kinetic parameters were determined according to Arrhenius equation with a value of energy activation (Ea) in the order of 352 kJ/mol. And also the k₀ collision factor was calculated.

Keywords : heavy oils; resin-asphaltene concentrate; pyrolysis conversion; elemental analysis; calorific power.

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