Abstract: The process of separating water and wash oil from a gaseous feed stream of water vapor, wash oil and light oil involving (a) directing the gaseous feed stream in an upward direction and in contact with a cooling solid surface such that a temperature gradient of the gaseous stream is produced such that the temperature of the gaseous stream is highest at the bottom of the cooling solid surface such that gaseous components of the gaseous stream having the highest boiling temperature condense onto the lower portions of the cooling solid surface and wherein the lower boiling components of the gaseous stream condense onto the solid surface at higher portions on the solid surface to thereby form a liquid film on the solid surface, which film then runs downward onto the lower portions of the solid surface to thereby inhibit deposits from adhering to these lower portions of the solid surface; (b) withdrawing a gaseous stream containing a major portion of light oil; and (c) withdrawing a liquid condensate which contain