| CPC C01B 23/0052 (2013.01) [C01B 2210/0014 (2013.01); C01B 2210/0028 (2013.01); C01B 2210/0031 (2013.01); C01B 2210/0046 (2013.01)] | 33 Claims |

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1. A non-cryogenic process for recovering high purity helium from a feed stream comprising a low helium content gas, the process comprising:
a) introducing the feed stream into a high pressure adsorption column or a low pressure adsorption column of a first dual reflux pressure swing adsorption (DRPSA) unit;
b) separating the feed stream by adsorption into a first reflux product and a first heavy product and circulating the first reflux product and the first heavy product in said first DRPSA unit to produce an intermediate helium-enriched stream;
c) withdrawing the intermediate helium-enriched stream from the first DRPSA unit and introducing the intermediate helium-enriched stream to a high pressure adsorption column or a low pressure adsorption column of a second DRPSA unit;
d) separating the intermediate helium-enriched stream by adsorption into a second reflux product and a second heavy product and circulating the second reflux product and the second heavy product in said second DRPSA unit to produce a high purity helium stream and a waste stream containing helium; and
e) withdrawing the waste stream containing helium from the second DRPSA unit and recycling thereof to one of a plurality of locations in the first DRPSA unit to increase helium recovery in the high purity helium stream produced in the second DRPSA unit.
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