UN PROCEDIMIENTO PARA REFINAR UN MATERIAL DE ALIMENTACION LUBRICANTE MEDIANTE UN DISOLVENTE.

摘要

A lubricating oil solvent refining process employing N-methyl-2-pyrrolidone as solvent in which solvent is recovered from a solvent-oil mixture in a staged series of vaporization zones at progressively increasing pressure with external heat supplied only to the vaporization stage having the highest pressure and control of vaporization in the lower pressure stages is effected by passing a minor portion of the vapors from the highest pressure stage to the lowest pressure stage. A high temperature vacuum flash vaporization zone may follow the high pressure vaporization stage with external heat supplied to the vacuum flash vaporization zone.