Abstract
In the conventional system of engine lubrication, luburicating oil is renewed with fresh oil after it is used for some period. Accordingly, waste oil is generated in the conventional system. The authors have developed a new technology which makes it possible to use lubricating oil semi-permanently without oil renewal and, therefore, without any waste oil. This technology has been working well in about one thousand marine and cogeneration diesel engines in practical use for many years. The new technology always keeps lubricating oil clean as the kidney of animals always keeps their blood clean. This is why lubricating oil can be used semi-permanently and the new technology is called kidney system. The techology can be used to clean and recycle many kinds of liguids. This paper reports about recycling the lubricating oil mixed in waste water from compressors in a fertilizer company.
