Douglas I. Exall & James Speight 
Refining Used Lubricating Oils [PDF ebook] 

Used lubricating oil is a valuable resource. This book examines recycling processes for a range of products with different properties and different criteria. It also compares the various recycling methods and resulting products to conventional products obtained from original refining processes. The reviews, data, and comparisons provided by the authors allow readers to identify which processes are likely to produce a product with specific properties, and enable them to combine this with an analysis of the economic data to identify attractive oil recycling propositions.