SOLVENT FOR REFINING OF RESIDUES

摘要

A process for solvent refining of a residual oil comprises contacting a residual oil in a solvenr refining zone with a refining solvent; recovering from the solvent refining zone a first mixture comprising solvent refined oil and refining solvent, and a second mixture comprising refining solvent and impurities separated from the residue, said impurities comprising pitch; introducing the first mixture into a first zone of a combination tower to separate refining solvent from solvent refined oil; introducing the second mixture into a second zone of a combination tower to separate refining solvent from impurities, said combination tower being operated at a pressure of no greater than about 70N/cm<2> gauge (100 PSIG); recovering solvent refined oil having a reduced quantity of refining solvent from the combination tower; recovering impurities having a reduced quantity of refining solvent from the combination tower; and recovering refining solvent from the combination tower for recycle to the solvent refining zone.