Major pathways for used oil disposal and recycling. Part 1

AbstractOne of the main concerns with lubricating oil relates to used oil management for both industrial and engine oils, although the environmental impact of gasoline and diesel engine oils is the most critical. Provided that efficient management systems are in place, most used oil should not reach the environment, so, the major question is how to dispose of collected used oil. The first option lies in burning it as a fuel, the second in recycling (reclaiming, reprocessing, re‐refining). The latter allows recovery of mineral base oils, which are valuable constituents of crude oil.Mobile (on site) and fixed plants for industrial oil recycling will first be discussed, and the paper will look at the most modern re‐refining processes that produce base oils of as high quality as virgin base oils. Based on current re‐refining experience, the quality of finished lubricants blended from re‐refined base stocks is also noted. Re‐refining today may be of significant benefit to the economy and can, of course, protect the environment. All modern re‐refining technologies produce small amounts of by‐products in which toxic materials may have been concentrated. A final aspect of reprocessing used oil is to integrate it, after hydrogen treatment, into existing refineries. This valuable raw material can then be directly routed to a lube oil unit or even to a cracking unit for conversion to gasoline. The integration of used oil treatment processes into selected refineries may be the most effective pathway to used oil disposal.In this first part, the author looks at the nature of the problems associated with used oil, its use as a fuel, and simple recycling. He then goes on to look at major re‐refining processes, starting with hydrogenation (KTI, Mohawk, BERC/NIPER, and PROP technologies). Part 2 will describe other processes, including a range of vacuum distillation/clay treatment technologies.