Characterizing Petroleum Vacuum Residue by Supercritical Fluid Extraction and Fractionation

Abstract

The goal of this work is to provide a novel separation method for petroleum vacuum residua instead of the traditional SARA (saturates, aromatics, resins, and asphaltenes composition analysis) or the high-vacuum distillation method. Supercritical fluid extraction and fractionation was employed to separate four Chinese vacuum residua into 15−17 narrow fractions with total extraction yields of 71.7−87.8 wt %. Physicochemical properties such as density, average molecular weight, kinematic viscosity, and carbon residue of each narrow fraction were obtained. Elemental analyses (C, H, N, S), heavy metals (Ni, V) concentrations, SARA analyses, and 1H-NMR tests provide insights in their chemical composition.