Recycling of Used Lubricating Oil Using Three Samples of Acids and Clay as a Method of Treatment

This research investigated the effect of three different acids (sulphuric acid, hydrochloric acid and nitric acid), on three different clay deposit samples, to recycle used lubricating oil. To achieve this objective, filtration of the used oil was carried out first to remove impurities like: sand, metal chip and other micro impurities using: Buncher funnel, filter papers and vacuum pump. The filtered oil was allowed to settle for twelve hours (12hrs), before being centrifuged for another 20mins at 10000rpm so any particles in the oil can settle and be decanted. Next, the oil was preheated to degrade some additives, which helped to reduce the work load when acid was added. 100ml of the preheated oil was measured and treated with 10ml of various acids (Sulphuric acid, Nitric acid and hydrochloric acid) in varied strengths, and then allowed to stand for thirty minutes in a separating funnel before being allowed to pass through the bed of clay using a vacuum pump. Caustic Soda was then added to the extracted oil to help neutralize the acid in the oil. The resulting oil was slightly dark in colour. Tests carried out were: flash point, cloud point, pour point, viscosity index, sulphur content and water content. The result show that compared with the standard value of fresh lube oil, the resultant oil from the analysis compared favourably. An appreciable increase in the flash point, cloud point, viscosity index, and sulphur content of the oil was noted when compared to the fresh lube oil.