This book shows the environmental and economic importance of waste lube oil re-refining process. It also, covers the well known processes applied in waste oil regeneration by covering the fundamental principles techniques such as vacuum distillation, solvent extraction, and filtration. A wide part is dedicated to applications with the description of many processes. In addition, it describes the manufacture of base oils in refineries, and mentions the main additives playing an essential role in the quality of the marketed finished oils.