Patent ID: 9433888
Filing Date: 2016-09-06
CPC Classification: B01D,C01B

Claim Text:
1. A method of recovering a first gas from a source gas comprising a minor amount of the first gas and an amount of a second gas at a higher concentration than that of the first gas, said method comprising the steps of: separating a first gas mixture with a first gas separation membrane into a first permeate and a first non-permeate; separating a second gas mixture with a second gas separation membrane into a second permeate and a second non-permeate; and separating the second non-permeate with a third gas separation membrane into a third permeate and a third non-permeate, wherein: each of the first, second, and third gas separation membranes includes a separating layer that is more permeable to the first gas than to the second gas; the third non-permeate is combined with a flow of gas from the source gas to provide the first gas mixture; the second permeate is divided into first and second portions, the second portion being a first product gas comprising the first gas; the first non-permeate is a second product gas comprising the second gas; the first portion and the third permeate are combined with the first permeate and their combination is compressed with a compressor to provide the second gas mixture; and a % recovery of the second gas is controlled by adjusting the allocation of the second permeate into the first and second portions with a valve assembly in a line receiving the second permeate.