Patent ID: 9427694
Filing Date: 2016-08-30
CPC Classification: B01D,B01J,C07C,C08F,Y02P

Claim Text:
1. A polyethylene production system comprising: an ethylene polymerization reactor system, a separator, one or more distillation columns, and at least two pressure swing adsorption units operated in parallel; wherein the ethylene polymerization reactor system is configured to receive a reagents stream and to produce a polymerization product stream; wherein the separator is configured to receive at least a portion of the polymerization product stream and to produce a polymer stream and a gas stream; wherein the one or more distillation columns are configured to receive at least a portion of the gas stream and to produce a light hydrocarbon stream, wherein the light hydrocarbon stream comprises a first hydrocarbon and a second hydrocarbon; wherein each of the at least two pressure swing adsorption units is configured to receive at least a portion of the light hydrocarbon stream and a sweeping gas stream, and to produce a non-adsorbed gas stream comprising the second hydrocarbon and a spent sweeping gas comprising the first hydrocarbon; wherein a hydrocarbon adsorber bed is disposed in each pressure swing adsorption unit, wherein the hydrocarbon adsorber bed comprises a hydrocarbon adsorber and wherein the hydrocarbon adsorber has an adsorption selectivity of the first hydrocarbon versus the second hydrocarbon as determined by volumetric adsorption at 298 K and at a first pressure of equal to or greater than about 2; wherein upon contact of the light hydrocarbon stream with the hydrocarbon adsorber at the first pressure the hydrocarbon adsorber adsorbs at least a portion of the first hydrocarbon of the light hydrocarbon stream to yield a loaded hydrocarbon adsorber comprising adsorbed first hydrocarbon, and the non-adsorbed gas stream comprising at least at least a portion of the second hydrocarbon of the light hydrocarbon stream; wherein the hydrocarbon adsorber regenerates at a second pressure to yield an unloaded hydrocarbon adsorber and a desorbed first hydrocarbon, wherein the desorbed first hydrocarbon comprises at least a portion of the adsorbed first hydrocarbon, and wherein the first pressure is greater than the second pressure by equal to or greater than about 400 kPa; and wherein the unloaded hydrocarbon adsorber is contacted with the sweeping gas stream to yield a purged hydrocarbon adsorber.