Process for separating components of a gas stream
AssigneeAir Products and Chemicals, Inc.
InventorsJung S. Choe, Steven R. Auvil, Rakesh Agrawal
Life of this patent
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Abstract
The present invention is a process for separating and recovering a component from a multi-component feed gas mixture. The feed gas mixture is initially separated in a membrane separation unit or units to produce a gas stream concentrated in the desired component. The concentrated gas stream is subsequently further separated in an adsorption unit having an adsorbent which selectively adsorbs non-desired gaseous components thereby producing a purified product stream. The non-desired gaseous components are subsequently desorbed and a purge stream from the adsorption unit containing the desorbed non-desired gaseous components along with a portion of the desired components is recycled to the feed gas mixture.
Claims32
A process for recovering a desire component from a multi-component feed gas stream, said process comprising:
- (a) passing said feed gas stream to a plurality of membrane separation units to produce a stream concentrated in the desired component;
- (b) passing said concentrated stream to an adsorption unit containing an adsorbent that selectively adsorbs non-desired gaseous components present in said stream to produce a product stream further concentrated in the desired component;
- (c) desorbing the gaseous components from said adsorbent;
- and
- (d) recycling said desorbed gaseous components to the feed gas stream entering the membrane separation units.
A process for separating a more permeable component of a multi-component feed gas mixture from a less permeable component and subsequently recovering said more permeable component as a purified product, said process comprising:
- (a) passing said multi-component feed gas mixture to a first membrane separation unit to produce a first permeate stream and a first reject stream;
- (b) passing said first permeate stream to an adsorption unit containing an adsorbent which selectively adsorbs less permeable components present in said permeate stream thereby producing a purified product stream;
- (c) desorbing the less permeable components from said adsorbent;
- (d) recycling said desorbed components to the feed gas stream entering the first membrane separation unit;
- (e) passing said first reject stream to a second membrane-separation unit to produce a second permeate stream and a second reject stream;
- and
- (f) combining said second permeate with said desorbed components prior to being recycled to the feed gas stream.
A process for separating a less permeable component of a multi-component feed gas mixture from a more permeable component and subsequently recovering said less permeable component as a purified product, said process comprising:
- (a) passing said multi-component feed gas mixture to a first membrane separation unit to produce a first permeate stream and a first reject stream;
- (b) passing said first reject stream to a second membrane separation unit to produce a second permeate stream and a second reject stream;
- (c) passing said second reject stream to an adsorption unit containing an adsorbent which selectively adsorbs more permeable components present in said reject stream thereby producing a purified product stream;
- (d) desorbing the more permeable components from said adsorbent;
- and
- (e) recycling said desorbed components to the feed gas stream entering the first membrane separation unit.
A process for separating nitrogen from air and subsequently recovering nitrogen as a purified product, said process comprising:
- (a) passing an air stream to a membrane separation unit to produce an oxygen-enriched permeate stream and a reject stream;
- (b) passing said reject stream to an adsorption unit containing an adsorbent which is selective for oxygen, thereby producing a purified nitrogen product stream;
- and
- (c) desorbing the oxygen from the adsorbent and recycling it back to the air stream entering the separator.
Dependencies are inferred from the claim text.