REFINING PROCESS WITH SOLVENT OF A LUBRICATING OIL MATERIAL, OIL-BASED, CONTAINING AROMATIC AND NON-AROMATIC COMPONENTS

摘要

A solvent refining process utilizing N-methyl-2-pyrrolidone as solvent in which the extract from the solvent extraction zone is cooled to form two immiscible liquid phases, a secondary extract phase and a secondary raffinate phase. The secondary raffinate phase is returned to the extraction zone resulting in increased yield of refined oil product and savings in energy required for the process.