A continuous thermal process for reclaiming useful products from a waste oil comprising solids, contaminants, and/or additives, the process comprising:
- performing thermal separation on the waste oil in a flash drum by heating the waste oil to a temperature below the cracking temperature of the waste oil and at a pressure below atmospheric pressure, comprised between 0.05 and 0.95 atmosphere, to obtain a first heavy oil vapor fraction and a second light oil gaseous fraction, said second light oil gaseous fraction having, in comparison with the waste oil, a lower content in solids, contaminants, and/or additives that are different from water and from inert gas;
- condensing the first heavy oil vapor fraction that exits the flash drum on a cooler surface of a dephlegmator and/or of a self-refluxing condenser directly mounted on the flash drum to provide a condensed liquid that falls back directly into the bottom part of the flash drum, while the second light oil gaseous fraction passes through the dephlegmator and/or of a self-refluxing condenser directly mounted on the flash drum;
- separating the second light oil gaseous fraction into a water phase, an oil phase, and gas phase;
- adding at least one inert gas or at least one component that may become an inert gas by heating in the waste oil and/or in the flash drum, optionally in an amount that represents 1 to 15% weight of the waste oil;
- recovering a first heavy oil liquid fraction at the bottom of the flash drum;
- and
- submitting the first heavy oil liquid fraction to a cracking treatment.