Concurrent O 2 generation and CO 2 control for advanced life support

• US 8,613,848 B2
• Filed: 04/30/2008
• Issued: 12/24/2013
• Est. Priority Date: 04/30/2007
• Status: Active Grant

• Current Assignee: University of Florida Research Foundation, Incorporated (State University System of Florida)
• Original Assignee: University of Florida Research Foundation, Incorporated (State University System of Florida)
• Inventors: Wachsman, Eric D., Duncan, Keith L., Hagelin-Weaver, Helena
• Primary Examiner(s): Ryan, Patrick
• Assistant Examiner(s): LEADER, WILLIAM T
• Application Number:
  US12/598,243
• Publication Number:
  US 20100147699A1
• Time in Patent Office: 2,064 Days
• Field of Search: 205/634
• US Class Current: 205/634
• CPC Class Codes: B01D 2256/12 Oxygen
• CPC Class Codes: B01D 2257/504 Carbon dioxide
• CPC Class Codes: B01D 2259/40088 by heating
• CPC Class Codes: B01D 2325/10 Catalysts being present on the surface of the membrane or in the pores
• CPC Class Codes: B01D 53/04 with stationary adsorbents B01D53/025 takes precedence
• CPC Class Codes: B01D 53/32 by electrical effects other than those provided for in group B01D61/00
• CPC Class Codes: B01D 53/62 Carbon oxides
• CPC Class Codes: B01D 63/06 Tubular membrane modules
• CPC Class Codes: B01D 63/087 Single membrane modules
• CPC Class Codes: B01D 69/04 Tubular membranes
• CPC Class Codes: B01D 69/08 Hollow fibre membranes manufacture of hollow fibres D01D5/24, D01F1/08
• CPC Class Codes: B01D 69/12 Composite membranes; Ultra-thin membranes
• CPC Class Codes: B01D 71/024 Oxides
• CPC Class Codes: B64G 1/48 for treatment of the atmosphere B64G1/50 takes precedence
• CPC Class Codes: B64G 6/00 Space suits
• CPC Class Codes: C01B 13/0203 from inorganic compounds
• CPC Class Codes: C25B 1/02 Hydrogen or oxygen
• CPC Class Codes: Y02C 20/40 of CO2
• CPC Class Codes: Y02P 20/151 Reduction of greenhouse gas [GHG] emissions, e.g. CO2

Abstract

A device for the concurrent oxygen generation and control of carbon dioxide for life support system involves two stages, where a first stage removes CO₂ from an exhalent side of a ventilation loop and a second stage employs Ceramic Oxygen Generators (COGs) to convert CO₂ into carbon and O₂. The first stage includes a plurality of chambers and means to switch the ventilation loop through at least one of the chambers, where CO₂ removal is carried out before discharge of the CO₂ depleted gas to an inhalant side of the ventilation loop, and to exclude the ventilation loop from the remaining chambers of the first stage, where these chambers are placed in communication with the second stage. The second stage has two portions separated by the COGs such that CO₂ and the formed carbon remain on an intake portion from the O₂ rich atmosphere on the exhaust side, which is plumbed via a metering valve to introduce the O₂ rich atmosphere to the inhalant side of the ventilation loop.

Claims

1. A device for continuous conversion of CO₂ to O₂ providing a breathable atmosphere, comprising:

at least one first stage comprising at least one inlet, at least one outlet, a plurality of sorption bed chambers, each chamber comprising at least one CO₂ sorption bed, a means to direct a gas flow to and from said chambers, and a means to actuate said means to direct; and

at least one second stage comprising at least one ceramic oxygen generator (COG) unit comprising a catalytic carbon deposition layer (CCDL) on a cathode of said COG, at least one CO₂ intake, at least one O₂ exhaust, and a means to control said exhaust from said second stage into said outlet of said first stage.

2. The device of claim 1, wherein said means to direct said gas flow comprises a first valve between said inlet and said bed and a second valve between said bed and said outlet, wherein when said first valve is in an open position said gas flow is directed to said chamber and said second valve is positioned to direct said gas flow to said outlet, and wherein when said first valve is in a closed position said gas flow is restricted from said chamber and said second valve is positioned to provide communication between said chamber and said intake of said second stage.

3. The device of claim 1, wherein said means to control said exhaust comprises a metering valve.

4. The device of claim 1, further comprising at least one CO₂ sensor in said outlet or at least one CO₂ sensor in each of said chambers, wherein said sensor provides a signal to each of said means to actuate when a level of CO₂ in said gas flow exceeds a predetermined level of CO₂ wherein said first and second valves of said plurality of said chambers are positioned to direct said gas flow to at least one, but not all, of said chambers and restrict gas flow to all other of said chambers.

5. The device of claim 1, further comprising at least one CO sensor in said second stage wherein said sensor provides a signal to an alarm when a predetermined level of CO is exceeded.

6. The device of claim 1, wherein said CCDL further comprises metal containing particles on a support.

7. The device of claim 1, wherein said CCDL further comprises metal containing particles on a support, wherein said metal comprises Fe, Ni, Co, alloys thereof, or oxides thereof.

8. The device of claim 1, wherein said CCDL further comprises metal containing particles on a support, wherein said metal comprises Fe, Ni, Co, alloys thereof, or oxides thereof, and wherein said particles are from about 10 to about 50 nm in size.

9. The device of claim 1, wherein said CCDL further comprises metal containing particles on a support, wherein said support is a Ni comprising wire mesh or a SiO₂comprising fiber cloth.

10. The device of claim 1, wherein said bed comprises polyethyleneimine deposited on mesoporous molecular sieves.

11. The device of claim 1, further comprising one or more heat exchangers.

12. A method of providing a breathable gas for life support, comprising the steps of:

adsorbing CO₂ from an exhaled gas flow in at least one first stage of a device, wherein said first stage comprises at least one inlet, at least one outlet, a plurality of sorption bed chambers, each chamber comprising at least one CO₂ sorption bed where said gas is depleted of CO₂, a means to direct a gas flow to and from said chambers or restrict flow from said chamber and place said chamber into communication with at least one second stage, and a means to actuate said means to direct;

directing said CO₂ depleted gas from said chamber to an inhalable gas flow;

converting said CO₂ to C and O₂ in said second stages of said device, wherein said second stage comprises at least one ceramic oxygen generator (COG) units comprising a catalytic carbon deposition layer (CCDL) on a cathode of said COG, at least one CO₂ intake, at least one O₂ exhaust, and a means to control said exhaust from said second stage; and

directing said O₂ from said exhaust to said inhalable gas flow.

13. The method of claim 12, wherein said means to direct said gas flow comprises a first valve between said inlet and said bed and a second valve between said bed and said outlet, wherein when said first valve is in an open position to direct said gas flow to said bed and said second valve is positioned to direct said gas flow to said outlet, and wherein when said first valve is in a closed position, restricts said gas flow to said bed and said second valve is positioned to provide communication between said chamber and said intake of said second stage.

14. The method of claim 12, wherein said means to control said exhaust comprises a metering valve.

15. The method of claim 12, wherein said first stage further comprises at least one CO₂ sensor in said outlet or at least one CO₂ sensor in each of said chambers, wherein said sensor provides a signal to each of said means to actuate when the level of CO₂ in said gas flow exceeds a predetermined level of CO₂ wherein said first and second valves of said plurality of said chambers are positioned to direct said gas flow to at least one, but not all, of said chambers and restrict gas flow to all other of said chambers.

16. The method of claim 12, wherein said second stage further comprises at least one CO sensor in said second stage wherein said sensor provides a signal to an alarm when a predetermined level of CO is exceeded.

17. The method of claim 12, wherein said CCDL further comprises metal containing particles on a support.

18. The method of claim 12, wherein said CCDL further comprises metal containing particles on a support, and wherein said metal particles comprise Fe, Ni, Co, alloys thereof, or oxides thereof.

19. The method of claim 12, wherein said CCDL further comprises metal containing particles on a support, and wherein said metal particles comprise Fe, Ni, Co, alloys thereof, or oxides thereof, and wherein said particles are from about 10 to about 50 nm in size.

20. The method of claim 12, wherein said CCDL further comprises metal containing particles on a support, and wherein said support is a Ni comprising wire mesh or a SiO₂ comprising fiber cloth.

21. The method of claim 12, wherein said bed comprises polyethyleneimine deposited on mesoporous molecular sieves.

22. A device for continuous conversion of CO₂ to O₂ providing a breathable atmosphere, comprising:

at least one first stage comprising at least one inlet, at least one outlet, a plurality of sorption bed chambers, each chamber comprising at least one CO₂ sorption bed, a means to direct a gas flow to and from said chambers, and a means to actuate said means to direct; and

at least one second stage comprising at least one ceramic oxygen generator (COG) unit comprising a graded bilayer electrolyte comprising a layer of cubic-stabilized bismuth oxide and a layer of acceptor-doped ceria between a cathode and an anode, at least one CO₂ intake, at least one O₂ exhaust, and a means to control said exhaust from said second stage into said outlet of said first stage.

23. The device of claim 22, wherein said means to direct said gas flow comprises a first valve between said inlet and said bed and a second valve between said bed and said outlet, wherein when said first valve is in an open position said gas flow is directed to said chamber and said second valve is positioned to direct said gas flow to said outlet, and wherein when said first valve is in a closed position said gas flow is restricted from said chamber and said second valve is positioned to provide communication between said chamber and said intake of said second stage.

24. The device of claim 22, wherein said means to control said exhaust comprises a metering valve.

25. The device of claim 22, further comprising at least one CO₂ sensor in said outlet or at least one CO₂ sensor in each of said chambers, wherein said sensor provides a signal to each of said means to actuate when a level of CO₂ in said gas flow exceeds a predetermined level of CO₂ wherein said first and second valves of said plurality of said chambers are positioned to direct said gas flow to at least one, but not all, of said chambers and restrict gas flow to all other of said chambers.

26. The device of claim 22, further comprising at least one CO sensor in said second stage wherein said sensor provides a signal to an alarm when a predetermined level of CO is exceeded.

27. The device of claim 22, wherein said second stage further comprises a catalytic carbon deposition layer (CCDL) on a cathode of said COG.

28. The device of claim 22, wherein said second stage further comprises a CCDL on a cathode of said COG, and wherein said CCDL comprises metal containing particles on a support.

29. The device of claim 22, wherein second stage further comprises a CCDL on a cathode of said COG, wherein said CCDL comprises metal containing particles on a support, and wherein said metal particles comprise Fe, Ni, Co, alloys thereof, or oxides thereof.

30. The device of claim 22, wherein said second stage further comprises a CCDL on a cathode of said COG, wherein said CCDL further comprises metal containing particles on a support, and wherein said metal particles comprise Fe, Ni, Co, alloys thereof, or oxides thereof, and wherein said particles are from about 10 to about 50 nm in size.

31. The device of claim 22, wherein said second stage further comprises a CCDL on a cathode of said COG, wherein said CCDL further comprises metal containing particles on a support, and wherein said support is a Ni comprising wire mesh or a SiO₂ comprising fiber cloth.

32. The device of claim 22, wherein said cubic-stabilized bismuth oxide comprises an erbia-stabilized bismuth oxide (ESB).

33. The device of claim 22, wherein said acceptor-doped ceria comprises a samaria- or a gadolinia-doped ceria (SDC or GDC).

34. The device of claim 22, wherein said cathode comprises a Pt-ceria cermet or a Pd-ceria cermet.

35. The device of claim 22, wherein said anode comprises a silver-ESB cermet.

36. The device of claim 22, wherein said bed comprises polyethyleneimine deposited on mesoporous molecular sieves.

37. The device of claim 22, further comprising one or more heat exchangers.

38. A method of providing a breathable gas for life support, comprising the steps of:

adsorbing CO₂ from an exhaled gas flow in at least one first stage of a device, wherein said first stage comprises at least one inlet, at least one outlet, a plurality of sorption bed chambers, each chamber comprising at least one CO₂ sorption bed where said gas is depleted of CO₂, a means to direct a gas flow to and from said chamber or restrict flow from said chamber and place said chamber into communication with at least one second stage, and a means to actuate said means to direct;

directing said CO₂ depleted gas from said chamber to an inhalable gas flow;

converting said CO₂ to C and O₂ in said second stages of said device, wherein said second stage comprises at least one ceramic oxygen generator (COG) unit comprising a graded bilayer electrolyte comprising a layer of cubic-stabilized bismuth oxide and a layer of acceptor-doped ceria between a cathode and an anode, at least one CO₂ intake, at least one O₂ exhaust, and a means to control said exhaust from said second stage; and

directing said O₂ from said exhaust to said inhalable gas flow.

39. The method of claim 38, wherein said means to direct said gas flow comprises a first valve between said inlet and said bed and a second valve between said bed and said outlet, wherein when said first valve is in an open position to direct said gas flow to said bed and said second valve is positioned to direct said gas flow to said outlet, and wherein when said first valve is in a closed position, restricts said gas flow to said bed and said second valve is positioned to provide communication between said chamber and said intake of said second stage.

40. The method of claim 38, wherein said means to control said exhaust comprises a metering valve.

41. The method of claim 38, wherein said first stage further comprises at least one CO₂ sensor in said outlet or at least one CO₂ sensor in each of said chambers, wherein said sensor provides a signal to each of said means to actuate when the level of CO₂ in said gas flow exceeds a predetermined level of CO₂, and wherein said first and second valves of said plurality of said chambers are positioned to direct said gas flow to at least one, but not all, of said chambers and restrict gas flow to all other of said chambers.

42. The method of claim 38, wherein said second stage further comprises at least one CO sensor in said second stage and wherein said sensor provides a signal to an alarm when a predetermined level of CO is exceeded.

43. The method of claim 38, wherein said second stage further comprises a catalytic carbon deposition layer (CCDL) on a cathode of said COG.

44. The method of claim 38, wherein said second stage further comprises a CCDL on a cathode of said COG, and wherein said CCDL further comprises metal containing particles on a support.

45. The method of claim 38, wherein second stage further comprises a CCDL on a cathode of said COG, and wherein said CCDL further comprises metal containing particles on a support, said metal particles comprising Fe, Ni, Co, alloys thereof, or oxides thereof.

46. The method of claim 38, wherein wherein second stage further comprises a CCDL on a cathode of said COG, wherein said CCDL further comprises metal containing particles on a support, said metal particles comprising Fe, Ni, Co, alloys thereof, or oxides thereof, and wherein said particles are from about 10 to about 50 nm in size.

47. The method of claim 38, wherein said second stage further comprises a CCDL on a cathode of said COG, wherein said CCDL further comprises metal containing particles on a support, and wherein said support is a Ni comprising wire mesh or a SiO₂ comprising fiber cloth.

48. The method of claim 38, wherein said cubic-stabilized bismuth oxide comprises an erbia-stabilized bismuth oxide (ESB).

49. The method of claim 38, wherein said acceptor-doped ceria comprises a samaria- or a gadolinia-doped ceria (SDC or GDC).

50. The method of claim 38, wherein said cathode comprises a Pt-ceria cermet or a Pd-ceria cermet.

51. The method of claim 38, wherein said anode comprises a silver-ESB cermet.

52. The method of claim 38, wherein said bed comprises polyethyleneimine deposited on mesoporous molecular sieves.