Patent ID: 6514319
Filing Date: 2003-02-04
Classification: B01D,C01B,Y02C,Y02P

Abstract:
Process for pressure swing adsorption separation of a feed gas mixture containing a more readily adsorbed component and a less readily adsorbed component, with the more readily adsorbed component being preferentially adsorbed from the feed gas mixture by an adsorbent material under increase of pressure, so as to separate from the feed gas mixture a heavy product gas enriched in the more readily adsorbed component and a light product gas enriched in the less readily adsorbed component; providing for the process a cooperating set of three adsorbers within a rotor and equally spaced angularly about the axis defined by rotation of the rotor relative to a stator, and rotating the rotor so as to generate within each adsorber cyclic variations of pressure and flow at a cyclic period defined by the frequency of rotation along a flow path contacting the adsorbent material between first and second ends of the adsorber, the cyclic variations of pressure extending between a higher pressure and a lower pressure of the process; rotating the rotor so that the first ends of the adsorbers successively communicate to feed and exhaust ports provided in a first valve surface between the rotor and the stator, and the second ends of the adsorbers successively communicate to a light product port, to light reflux exit ports and to light reflux return ports provided in a second valve surface between the rotor and the stator; the process including for each of the adsorbers in turn:(a) supplying feed gas mixture at a feed pressure through the feed port to the adsorber over a feed interval which is substantially &frac13; of the cycle period so as to pressurize the adsorber to substantially the higher pressure, and then to deliver light product gas from the light product port at substantially the higher pressure less flow frictional pressure drops, (b) withdrawing light reflux gas enriched in the less readily adsorbed component from the light reflux exit ports, in part to depressurize the adsorber after the feed interval, (c) withdrawing second product gas at an exhaust pressure through the exhaust port from the adsorber over an exhaust interval which is substantially &frac13; of the cycle period so as to depressurize the adsorber to substantially the lower pressure while delivering the second product gas, (d) returning light reflux gas enriched in the less readily adsorbed component from the light reflux return ports so as to purge the adsorber in the latter part of the exhaust interval and then to partially repressurize the adsorber prior to the next feed interval, so that feed gas is continuously supplied to substantially one adsorber at time, and exhaust gas is continuously removed from substantially one adsorber at a time.