Provided herein are processes for preparing estolides and estolide base oils from fatty acid reactants utilizing catalysts. Further provided herein are processes for preparing carboxylic esters from at least one carboxylic acid reactant and at least one olefin.

The lubricating base oil of the invention is characterized by satisfying at least one of the following conditions (a) or (b). (a) A saturated compound content of 95% by mass or greater, and a proportion of 0.1-10% by mass of cyclic saturated compounds among the saturated compounds.(b) The condition represented by the following formula (1). 1.435≦n20−0.002×kv100≦1.450 (1) wherein n20 represents the refractive index of the lubricating base oil at 20° C., and kv100 represents the kinematic viscosity (mm2/s) of the lubricating base oil at 100° C.

The invention provides a lubricant composition containing (A) an ionic liquid having an anion represented by formula 1: (Rf1-SO2) (Rf2-SO2) N− or formula 2: (Rf3) (Rf3) (Rf3) PF3− wherein Rf1 and Rf2 in formula 1 may be the same or different and are each F, CF3, C2F5, C3F7 or C4F9, and Rf3 in formula 2 may be the same or different and is CF3, C2F5, C3F7 or C4F9; and (B) a fatty acid amine salt in an amount of 0.1 to 5.0 mass %. The lubricant composition of the invention can favorably be used under a high vacuum or an ultra high vacuum, or under high temperatures, and exhibits excellent rust prevention properties.

Systems and methods are provided for hydroprocessing a petroleum fraction, such as a bottoms fraction from a fuels hydrocracking process, to generate a lubricant base oil. A fuels hydrocracking process typically has less stringent requirements for the sulfur and nitrogen content of a feed as compared to a lubricant base oil. Additionally, depending on the nature of the feed for the fuels hydrocracking process, the bottoms fraction may contain a relatively high level of aromatics compounds. The aromatic content of such a petroleum fraction can be reduced using a aromatic saturation stage with multiple catalyst beds, or alternatively using a reactor (or reactors) with multiple aromatic saturation stages. The catalysts in the various beds or stages can be selected to provide different types of aromatic saturation activity. An initial bed or stage can provide activity for saturation of 1-ring aromatics in the petroleum fraction. One or more subsequent beds or stages, operating at successively lower temperature, can then be used to reduce the multiple-ring aromatic content of the petroleum fraction.