Abstract
Two vacuum residues were delivered from two different petroleum refineries, one from Suez Petroleum Company and the second from Alexandria Petroleum Company. Two heavy residues were subjected to solvent extraction using n-pentane, n-heptane, and ethyl acetate. The studied residues were fractionated into their components. Infrared spectroscopy was applied to study the distribution of functional groups contained in samples and their components. Some ratios calculated from the peak heights of selected infrared bands allow for a better comparison. The UV-Vis spectroscopic technique was applied to the aromatic fraction to determine how much mono-, di-, and polyaromatics are present in the aromatic fraction. The monoaromatics represent the lowest constituent among the aromatics present, whereas the polyaromatics and diaromatics are predominantly present and form the major constituent.