摘要 |
The present invention provides a method and an apparatus for recovery of spent lubricating oil. The evaporation of hydrocarbon fractions from spent lubricating oil is carried out in three steps. The first step is at approximately 150-1030 mbar and between 70-240° C. in which is greater than 99% water, greater than 99% of ethylene glycol and greater than 50% of hydrocarbon molecules with normal boiling point up to 310° C. are evaporated from spent oil. The second step is operated at 6-30 mbar and 200-2900 C in which predominantly gasoil and light vacuum gasoil fractions are evaporated. The third step is operated at 250-320° C. and 0.5-15 mbar in which mainly heavy vacuum gasoil (boiling range of 425 to 570° C. on ASTM D-1160 test) is evaporated from spent oil. |