Shunichiro Takaoka*

*Takaoka Chemical Laboratory of Resource, Inc. Laboratory Director
(3-26, Yamanomae-cho, Kagami, Kagamihara, Gifu 509-01 Japan)

Abstract

Lubricating oils, used by industry and motorcars, are usually re-refined by chemical treatment, such as with sulfuric acid. There are many other re-refining methods of these oils, but these are not sufficient from in terms of reclaimed oil quality, processing efficiency and other economic considerations. In this paper, results of a pilot plant for a new treatment method, composed of (1) high temperature vacuum distillation, (2) gas removal and (3) rapid cooling, are reported and discussed. In this re-refining method, the first vacuum distillation reclaims the "bottom oil" from the waste oil, then this "bottom oil" is washed with sulfuric acid and contacted with active clay. The oil is again treated with vacuum distillation. The lubricating oil finally reclaimed by this treatment process has better quality than any other re-refined waste oil.

Key words: Waste lubricating oil, Oil re-refining, Vacuum distillation, Acid washing, Active clay