Hydrogen-treating of Some Lubricating Oil Fractions

Abstract

Paraffinic distillate lubricating oil fractions-a spindle oil fraction, a machine oil fraction, a solvent-extracted turbine oil fraction, and two kinds of solvent-extracted motor oil fractions different in the severities of solvent extraction-from Persian Gulf crude were hydrogen-treated, over a CoMo-sulfide/alumina catalyst, under hydrogen pressures. Bench-scale pilot plants were used for the hydrogen-treatment. Hydrogen-treated lubricating oils having favorable general propertiese. g., color, viscosity index, aniline point, sulfur content, and nitrogen content-were obtained by the treatment under relatively severe conditions. General properties of these oils were better than those of acid/clay-treated oils. Under the severe treating conditions, however, viscosity of the hydrgentreated oils was slightly reduced, and their oxidation stability was decreased. On the other hand, hydrogen-treated oils having good oxidation stability were obtained by the treatment under relatively mild conditions. The oxidation stability of these oils was almost the same with that of acid/claytreated oils. And the general properties of the product oils obtained by these mild hydrogen-treatment were also almost equal to those of acid/clay-treated oils.