Used lubricating oil contains more than 90% of good base oil and available additives, providing the potential of energy conservation, environmental protection, and economy, though it loses its useful performance because of contamination by impurities, oxidation, and degradation of additives. Many countries around the world have focused on reclamation and re-refining methods to treat and reuse waste lubricating oils for many years. But the regeneration rate of waste oils is very low in China, less than 20% of the lubricant consumption. Few studies on the performance, especially lubrication prop...
