The importance of oil as a lubricating agent for mechanical parts in motion is well known. Adding oil into the engine of a vehicle and noticing that it turns black upon use is a common phenomenon witnessed by all vehicle owners. Indeed, we know that the life cycle of oil is not infinite even if the efficiency of additives is regularly improved. Thus, oil becomes an unavoidable waste and its collection and treatment naturally become important issues for discussion. Owing to the rules that have been in existence in France since 1979 as well as to the financial support from the government via ADEME and last but not least, to the increasing civic responsibihty of the people, a collection rate higher than 80 % for all waste oil is achieved today. Two elimination methods or more precisely two valorization methods are then applied: on the one hand, combustion, a form of energy recovery used mainly in cement factories, and on the other, regeneration, a recycling of the raw material. A European directive gives preference to the latter method. In the United States and in Japan, there are no rules that give priority to any particular method of treatment. Whatever the method used locally, the choice ultimately depends on technical and economic criteria, obviously keeping in mind the impact on the environment, which should be minimized at all costs. The subject remains topical and other methods are also examined here, for example, the consideration of a possible participation of oil refiners in a consortium.
