Methods and systems for re-refining and upgrading spent oil

摘要

The method for re-refining the used oil is to carry out continuous liquid-liquid solvent extraction by bringing the feedstock containing the refined used oil into contact with the extraction solvent, and to use the extraction solvent and the extract dissolved in the extraction solvent. Includes the production of extraction logistics, including. The feedstock and extraction solvent are stirred by a variable speed stirrer during solvent extraction at a stirring speed of choice. The extract is separated from the extraction solvent and undergoes continuous flow-liquid phase hydrogenation treatment to produce an oil product. The system for performing this method includes a refiner for refining used oil, an extraction column for extracting the extract from the feedstock, and a continuous flow phase hydrotreater. The extraction column includes a stirrer configured to agitate the feedstock and extraction solvent passing through the extraction column at a variable agitation rate.