DENITROGENATION OF LUBRICATING BASE OILS BY SOLID ACID

Oxidation stability is one of the most important properties of lubricating base oils. Nitrogen compounds especially basic nitrogen compounds play a negative role to the oxidation stability of lubricating base oils. A new method to remove the nitrogen compounds of lubricating base oils is suggested in the paper. A type of solid acid was employed as an effective reagent to get rid of the basic and non-basic nitrogen compounds while it removes relatively less sulfur compounds. Clay treating after the solid acid denitrogenation can apparently improve the oxidation stability of denitrogenated base oils. Appropriate conditions are found for the solid acid denitrogenation.