Abstract

Lubricating oils are viscous liquids used for lubricating moving part of engines and machines. Since lubricating oils are obtained from petroleum – a finite product, and with dwindling production from world oil reserves, the need arises more than ever, to recycle used lubricating oils. Accordingly, this research effort focuses on comparative study of four methods of recycling of used lubrication oils: acid/clay treatment, distillation/clay, acid treatment and activated charcoal/clay treatment methods. Test carried out on the recycled lubrication oil include: flash point, pour point, specific gravity, metal contents, viscosity and sulphur contents. The results from the tests showed that, viscosity increased from 25.5 for used lube oil to 86.2 for distillation, 89.10 for acid/clay treatment and 80.5 is for activated/clay treatment. This is compared with 92.8 cs for fresh lube oil. Other results from the different tests showed varied degrees of improvement with the best results obtained using the acid/clay treatment.

Key words: Lubrication, refining, environmental pollution, viscosity