Energy efficient membrane-based process for co2 capture

Patent metadata

Field	Value
Publication number	US-2019282952-A1
Application number	US-201916353061-A
Country	US
Kind code	A1
Filing date	Mar 14, 2019
Priority date	Mar 14, 2018
Publication date	Sep 19, 2019
Grant date	—

Abstract

Processes and systems for the energy efficient capture of CO2 from a flue gas stream such as produced or resulting from power plant operation, are provided. The processes and systems integrate the use of high CO2/N2 selectivity membranes and high CO2 flux membranes, to capture CO2. Useful membranes can desirably be graphene oxide-based membranes.

First claim

What is claimed includes:

1 . An energy efficient process for the capture of CO 2 from a flue gas stream containing at least 5 vol. % CO 2 , the process comprising:
introducing the flue gas stream containing at least 5 vol. % CO 2 to a first stage membrane separator containing a first stage high CO 2 /N 2 selectivity membrane to produce a first stage CO 2 -depleted retentate stream and a first stage CO 2 -enriched permeate stream; introducing the first stage CO 2 -depleted retentate stream to a second stage membrane separator containing a second stage high flux membrane to produce a second stage further CO 2 -depleted retentate stream and a second stage CO 2 -enriched permeate stream; treating the second stage CO 2 -enriched permeate stream to recover water and form a recyclable CO 2 stream; introducing the recyclable CO 2 stream to the first stage membrane separator; treating the first stage CO 2 -enriched permeate stream to recover water and form a non-condensable CO 2 -rich stream; and compressing the CO 2 of the CO 2 -rich stream to form a capture quantity of CO 2 .

2 . The process of claim 1 wherein the first stage high CO 2 /N 2 selectivity membrane is a graphene oxide-based membrane.

3 . The process of claim 1 wherein the first stage high CO 2 /N 2 selectivity membrane has a target CO 2 /N 2 selectivity of ≥120.

4 . The process of claim 1 wherein second stage high flux membrane is a graphene oxide-based membrane.

5 . The process of claim 1 wherein second stage high flux membrane has a target CO 2 permeance of ≥1,000 GPU.

6 . In a power plant operation that produces a flue gas stream containing at least 5 vol. % CO 2 , the process of claim 1 for capture of CO 2 from the flue gas stream.

7 . An energy efficient process for the capture of CO 2 from a flue gas stream containing less than 5 vol. % CO 2 , the process comprising:
introducing the flue gas stream containing less than 5 vol. % CO 2 to a second stage membrane separator containing a second stage high flux membrane to produce a second stage CO 2 -depleted retentate stream and a second stage CO 2 -enriched permeate stream; treating the second stage CO 2 -enriched permeate stream to recover water and form a recyclable CO 2 stream; introducing the recyclable CO 2 stream to a first stage membrane separator containing a first stage high CO 2 /N 2 selectivity membrane to produce a first stage CO 2 -depleted retentate stream and a first stage CO 2 -enriched permeate stream; treating the first stage CO 2 -enriched permeate stream to recover water and form a non-condensable CO 2 -rich stream; introducing the first stage CO 2 -depleted retentate stream to the second stage membrane separator; and compressing the CO 2 -rich stream to a sequestration pressure.

8 . The process off claim 7 wherein the first stage high CO 2 /N 2 selectivity membrane is a graphene oxide-based membrane.

9 . The process of claim 7 wherein the first stage high CO 2 /N 2 selectivity membrane has a target CO 2 /N 2 selectivity of ≥120.

10 . The process of claim 7 wherein second stage high flux membrane is a graphene oxide-based membrane.

11 . The process of claim 7 wherein second stage high flux membrane has a target CO 2 permeance of ≥1,000 GPU.

12 . In a power plant operation that produces a flue gas stream containing less than 5 vol. % CO 2 , the process of claim 7 for capture of CO 2 from the flue gas stream.

13 . A system for capture of CO 2 from a flue gas stream, the system comprising:
a first stage membrane separator containing a first stage high CO 2 /N 2 selectivity membrane; a first stage vacuum pump to provide a vacuum on a permeate side of the first stage high CO 2 /N 2 selectivity membrane; wherein the first stage membrane separator produces a first stage CO 2 -depleted retentate stream and a first stage CO 2 -enriched permeate stream; a second stage membrane separator containing a second stage high flux membrane, the second stage separator receiving the CO 2 -depleted retentate stream; a second stage vacuum pump to provide a vacuum on a permeate side of the second stage high flux membrane; wherein the second stage membrane separator produces a second stage CO 2 -depleted retentate stream and a second stage CO 2 -enriched permeate stream.

14 . The system of claim 13 wherein the flue gas stream contains at least 5 vol. % CO 2 , the system further includes a feed line to introduce the flue gas stream containing at least 5 vol. % CO 2 to the first stage membrane separator.

15 . The system of claim 13 wherein the flue gas stream contains less than 5 vol. % CO 2 , the system further includes a feed line to introduce the flue gas stream containing less than 5 vol. % CO 2 to the second stage membrane separator.

16 . The system of claim 13 additionally comprising a cooler to cool at least one of the first stage CO 2 -enriched permeate stream and the second stage CO 2 -enriched permeate stream to condense and separate water therefrom.

17 . The system of claim 13 wherein the first stage high CO 2 /N 2 selectivity membrane is a graphene oxide-based membrane.

18 . The system of claim 13 wherein the first stage high CO 2 /N 2 selectivity membrane has a target CO 2 /N 2 selectivity of ≥120.

19 . The process of claim 13 wherein second stage high flux membrane is a graphene oxide-based membrane.

20 . The process of claim 13 wherein second stage high flux membrane has a target CO 2 permeance of ≥1,000 GPU.

Assignees

• Gas Technology Inst

Inventors

• Li Shiguang
• Pyrzynski Travis

Classifications

• B01D61/00

  Processes of separation using semi-permeable membranes, e.g. dialysis, osmosis or ultrafiltration; Apparatus, accessories or auxiliary operations specially adapted therefor (separation of gases or vapours by diffusion B01D53/22) · CPC title

• C01B32/50

  Carbon dioxide · CPC title

• B01D53/228

  characterised by specific membranes · CPC title

• B01D2257/504

  Carbon dioxide · CPC title

• B01D53/226 Primary

  in serial connexion · CPC title