Abstract: A liquid having certain undesired elements therein is distilled in a distillation column to form a vapor stream. This vapor stream is fed by means of an inert gas drive to a first container having an array of semi-permeable screens which are rotated at a speed of 3,000-10,000 rpm to generate vertical spiral vortexes which act on the vapor to separate out heavier impurities. An inert gas is employed to drive the vapor stream from the first container to the bottom of a second container having a narrower diameter array of semi-permeable screens, these screens being driven at a velocity of 6000-100,000 rpm. In the second container, the molecular species is separated from the main vapor stream by virtue of the exposure of the vapor to large centrifugal gravity forces generated by the horizontal velocity vectors of the rotating screens.