Optimizing the Composition of Base Oils in Hydrotreating on Catalyst Composites

Abstract

0009-3092/05/4104–0313 © 2005 Springer Science+Business Media, Inc. There is no experience in Russia in the selection, grading, and special processing of valuable lube oil crudes, i.e., crudes containing lube oils with a high viscosity index. These crudes are usually shipped to oil refineries (OR) mixed with ordinary crudes, which makes it difficult to obtain quality lube oils. The quality of the base oils obtained with selective extraction technology is basically determined by the hydrocarbon composition of the refined crudes. For this reason, hydrogenation processes that can be used to regulate such properties of lube oils as viscosity-temperature and low-temperature, color, sulfur content, etc., are of special interest in lube-oil production process schemes. The viscosity-temperature characteristic – the viscosity index (VI) – is one of the basic indexes of the quality of a base oil. It determines the suitability of a lubricant in the conditions of use and is a function of the group hydrocarbon composition of the base oil. n-Paraffins have the most gently sloping curve of the viscosity as a function of the temperature. Their VI is over 200. For isoparaffins, this index is lower and decreases with an increase in the degree of branching of their molecules. Polycyclic aromatic hydrocarbons have the steepest viscosity–temperature curve.