REMOVAL OF AROMATICS AND SULFUR FROM LUBRICATING OIL BASE STOCK BY LIQUID EXTRACTION USING IONIC LIQUIDS

The interest in producing high class lubricating oil base stock (base oil) has received
a considerable attention in the recent years. This was driven by the strict
environmental regulations and higher product specifications to meet better
performance required by the end users. Thebase oil of Group I class is conventionally
produced through solvent treatment process, while a hydroprocessing are required for
the production of higher class base oil of Group II & III which have lower aromatic
(less than 10%) and sulfur content (less than 300 ppm) compared to GROUP I,
according to American Petroleum Institute classification. However, the significant
investment coupled with the severe operating conditions, i.e., high temperature and
pressure, high hydrogen demand, expensive catalyst and high environmental impact
have led to the necessity of developing better alternative involving milder operating
conditions with lower investment cost and environmental impact.