ESTIMATION of PROPERTIES of Vacuum Residue and Its Fractions USING Supercritical Extraction and Chemometrics

The technique of supercritical fluid extraction has been considered as an alternative tool to increase acknowledges and behavior of the vacuum residue refining schemes. The Colombian Petroleum Institute ICP, has built A supercritical extraction pilot unit for two purposes: the first, to remove significant amounts of fractions of different types of vacuum residue and the second, to expand its characterization.

The extraction tests were performed with n-hexane for three temperature conditions 250, 265 and 280 º C, in the pressure range from 550 to 1250 psi. For the development of this section 12 residue vacuum were selected from different distillation units at the refinery of Barrancabermeja, with purpose to cover a wide range of compositions.

Vacuum residue and the fractions obtained by supercritical extraction were analyzed by density, viscosity, sulfur content, conradson carbon residue, SARA compositional analysis and metals (nickel and vanadium). Subsequently, each of the samples was characterized by the techniques of infrared spectroscopy (MIR) and ultraviolet visible (UV-VIS). Finally, this research developed a methodology for characterizing vacuum residue and their fractions from models of partial least squares regression based on spectroscopic techniques and the software The Unscrambler 9.8.