Re-refining of Used Lube Oil, II- by Solvent/Clay and Acid/Clay-Percolation Processes

Abstract

Used oils are lubricating oils which have become unsuitable for their proposed use. They may be recycled through the use of re-refining process to achieve useful products. This study compares two different re-refining processes. A laboratory scale setup of solvent extraction/clay and acid/clay-percolation processes were established to re-refine used oil collected from different sources. A comparison of its product characteristics with virgin base oil and with Egyptian standard regeneration lubricating oil characteristics is introduced. The results showed that, pour point increased from-15C for feed oil to-2C for acid/clay-percolation process and-6C for solvent/clay process. This is compared with-8C for virgin base oil. Sulfur content was found about 0.42wt% for acid/clay-percolation and 0.81 wt % for solvent/clay. In general, a best quality of the re-refined base oil using acid/clay-percolation was obtained and nearly meets the Egyptian standards. On the other hand, a higher yield of about 83 % using solvent extraction/clay treatment was achieved.