(108a) Characterization of Heavy Oil Polar Components by Solubility Separations

An automated separation based on the solubility of precipitated asphaltenes provides a unique approach to the characterization of heavy oil components. The technique employs an inert polytetrafluoroethylene (PTFE)-packed column to conduct on-column asphaltene precipitation and re-dissolution. Quantitative estimation of the distribution of molecular component types by polarity is accomplished using an evaporative light scattering detector (ELSD). The observed separation patterns can be evaluated in terms of the model of asphaltene component molecules consisting of 4-10 pericondensed rings with 4-6 alkyl side chains, with average H/C atomic ratio of 1.2, molecular weights near 750 g/mol, and sulfur and nitrogen functional groups.