GPC Separation and Integrated Structural Analysis of Petroleum Heavy Ends

Abstract

Three hundred grams of a Venezuelan asphalt was separated on a 70-liter GPC column in one run. The 30 cuts collected were consolidated to 7 fractions. After separating the insoluble asphaltenes from the soluble maltenes by n-pentane extraction, the maltenes were chromatographed on deactivated alumina into oil and three different resin fractions. Selected fractions were analyzed by NMR, IR, density, and elemental analysis. The experimental results were evaluated by a novel method making use of an extensive scheme of structure relations. Percentages of aromatic, naphthenic, and paraffinic carbon; number of ring systems per molecule, their average size, compactness, composition, and substitution are given explicitly or implicitly.