Chemical Characterization of Heavy Oils Using HPLC/FI-MS. —Analysis of a Petroleum Vacuum Residue—.

Abstract

An analytical system, in which a combination of two-stage HPLC and field ionization-mass spectrometry (FI-MS) are used and the results being processed with a computer, was applied to obtaining information on main chemical components contained in vacuum residue derived from crude oil. In the present study, a high degree of analytical accuracy, more so than in case of coal tar or coal derived liquids, should be strived for, because vacuum residue contains more complex chemical components. The sample oil, vacuum residue derived from Arabian crude oil, was preseparated into 4 fractions by HPLC on silica gel columns, followed by further separation into totally 22 subfractions on cyano columns or ion-exchange resins. The data obtained from FI-MS analysis of all subfractions were presented in a tabular form with 14 columns by the computer so that members of any homologous series appear in the same column. The components in sample oils were classified into identifiable 75 compound classes. Based on these analytical data, the ratio of elements, number average molecular weight and aromaticity of the vacuum residue were calculated, which values being compared with measured values in order to evaluate the validity of the present analytical system. © 1991, The Japanese Association of Educational Psychology. All rights reserved.