Used lubricating oil regeneration by various solvent extraction techniques

The used lubricating oil regeneration using extraction technique has been widely known as one of the cheapest and most competent processes. The best performance of solvent was shown by R-11 as the lowest percent oil losses, followed by CFC-113, MEK, 1-butanol, and 2-propanol. This performance sequence could be also evaluated by method of solubility parameter difference (Es) using Hildebrand and Peng–Robinson EoS approaches. The effectiveness of extraction parameters was also studied. The percent oil losses decreased with the extraction temperature. The values of optimum ratio of solvent to oil obtained by the Es method gave reasonable results compared to the experimental method.