Membrane absorption process for co2 capture

Patent metadata

Field	Value
Publication number	US-2019282953-A1
Application number	US-201916353079-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 capture of CO 2 from a CO 2 -containing gas stream are provided. The CO 2 -containing gas stream is passed to a membrane contactor absorber wherein the CO 2 -containing gas contacts or passes a first side of a membrane element while a CO 2 selective solvent with a viscosity between 0.2 and 7 cP contacts, passes or flows on second side of the membrane, opposed to the first side. The CO 2 permeates through the hollow fiber membrane pores and is chemically absorbed into the solvent.

First claim

What is claimed includes:

1 . A process for CO 2 capture, the process comprising:
passing a CO 2 -containing gas stream to a membrane contactor absorber containing a membrane element, wherein the CO 2 -containing gas stream contacts a first side of the membrane element and wherein a CO 2 selective solvent is in flow communication with a second side of the membrane element, the second side of the membrane element being opposed to the first side, wherein the CO 2 selective solvent has a viscosity between 0.2 and 7 cP and wherein CO 2 permeates through the membrane element and is chemically absorbed into the CO 2 selective solvent.

2 . The process of claim 1 wherein the CO 2 chemically absorbed into the CO 2 selective solvent forms a CO 2 -rich solvent and wherein said process additionally comprises:
regenerating the solvent by removing CO 2 from the CO 2 -rich solvent, and
recycling the regenerated solvent to the membrane contactor absorber.

3 . The process of claim 1 wherein the CO 2 -containing gas stream comprises a CO 2 -containing flue gas stream.

4 . The process of claim 1 wherein the CO 2 selective solvent has a viscosity between 1 and 5 cP.

5 . The process of claim 1 wherein the membrane element comprises a hollow fiber membrane element having a bore side and an opposed outside.

6 . The process of claim 5 wherein the CO 2 -containing gas stream passes through the membrane contactor absorber in a velocity in a range of 1-30 m/s and the CO 2 selective solvent passes through the membrane contactor absorber in a velocity in a range of 0.001-0.010 m/s.

7 . The process of claim 5 wherein the CO 2 -containing gas stream is passed on the bore side of the hollow fiber membrane element and the CO 2 selective solvent is passed on the outside of the hollow fiber membrane element.

8 . In a process of operating of a power plant that produces a CO 2 -containing gas stream, the process of claim 1 wherein the CO 2 -containing gas stream passed to the membrane contactor absorber comprises the power plant produced CO 2 -containing gas stream.

9 . The process of claim 8 wherein the power plant is a natural gas-fired power plant.

10 . The process of claim 8 wherein the power plant is a coal powered power plant.

11 . The process of claim 1 wherein the CO 2 selective solvent is selected from the group consisting of amines and promoted carbonate solvents.

12 . A method for improving separation of CO 2 from a CO 2 -containing gas stream via membrane processing wherein the CO 2 -containing gas stream contacts a first side of a membrane element and a CO 2 selective solvent is in flow communication with a second side of the membrane element, the second side of the membrane element being opposed to the first side and wherein CO 2 permeates through the membrane element and is chemically absorbed into the CO 2 selective solvent, the improvement comprising:
adjusting the CO 2 selective solvent to have a viscosity in a range between 0.2 and 7 cP.

13 . The method of claim 12 wherein the adjusting the CO 2 selective solvent comprises adjusting the CO 2 selective solvent to have a concentration of less than 50 wt. %.

14 . The method of claim 12 wherein the adjusting the CO 2 selective solvent comprises adjusting the CO 2 selective solvent to have a concentration of less than 40 wt. %.

15 . The method of claim 12 wherein the adjusting the CO 2 selective solvent comprises adjusting the CO 2 selective solvent to have a concentration in a range of at least 30 wt. % and less than 40 wt. %.

16 . The method of claim 12 wherein the CO 2 is chemically absorbed into the CO 2 selective solvent in a membrane contactor absorber to form a CO 2 -rich solvent, said method additionally comprising:
regenerating the solvent by removing CO 2 from the CO 2 -rich solvent, and
recycling the regenerated solvent to the membrane contactor absorber.

17 . The method of claim 12 comprising:
adjusting the CO 2 selective solvent to have a viscosity in a range between 1 and 5 cP.

18 . The method of claim 12 wherein the membrane element comprises a hollow fiber membrane element having a bore side and an opposed outside and wherein the CO 2 -containing gas stream passes through the membrane in a velocity in a range of 2-20 m/s and the CO 2 selective solvent passes through the membrane absorber in a velocity in a range of 0.001-0.010 m/s.

19 . A system for capturing CO 2 from a CO 2 -containing gas stream, the system comprising:
a membrane contactor absorber containing a membrane element, wherein the CO 2 -containing gas stream contacts a first side of the membrane element and wherein a CO 2 selective solvent is in flow communication with a second side of the membrane element, the second side of the membrane element being opposed to the first side, wherein the CO 2 selective solvent has a viscosity between 0.2 and 7 cP and wherein CO 2 permeates through the membrane element and is chemically absorbed into the CO 2 selective solvent to form a CO 2 -rich solvent; a desorber to accept the CO 2 -rich solvent from the membrane contactor absorber to remove CO 2 from the CO 2 -rich solvent to form a regenerated solvent; and a return line to forward the regenerated solvent to the membrane contact absorber.

Assignees

• Gas Technology Inst

Inventors

• Li Shiguang
• Pyrzynski Travis
• Meyer Howard
• Klinghoffer Naomi
• Tamale Timothy

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

• B01D53/229

  Integrated processes (Diffusion and at least one other process, e.g. adsorption, absorption) · CPC title

• B01D2257/504

  Carbon dioxide · CPC title

• B01D53/1475

  Removing carbon dioxide · CPC title

• B01D53/22 Primary

  by diffusion (manufacturing semi-permeable membranes B01D67/00; form, structure or properties of semi-permeable membranes B01D69/00; material for semi-permeable membranes B01D71/00) · CPC title