Abstract: SOTU (Slop Oil Treatment Unit) is a new heavy dirty oil treatment technology, which adopts a multi-stage cycle treatment process. After demulsification and nucleation by ultrasonic demulsification, sub-high-frequency vibration and high-energy electron beam in the pretreatment part, the solid impurities are removed in the first stage separation, and water is removed in the second stage separation, then the waste oil is transported to the device or returned to the original tank for refining. The density difference of heavy dirty oil and water of Tahe Refining and Chemical Co. is small, and the content of solid impurity is high, which is difficult to deal with by traditional process. After treatment by SOTU, the water content of dirty oil is 1.45%(w), and the oil content of treated sewage is 49.3 mg/L, which is better than the target that the water content of dirty oil is less than 3.0%, and the oil content of treated sewage is less than 150 mg/L.

Key words: dirty oil, SOTU technology, nucleation, demulsification, separation