CONTAMINANT SEPARATOR AND ISOLATION LOOP FOR A FUEL REACTANT STREAM FOR A FUEL CELL

• US 20090246573A1
• Filed: 09/20/2006
• Published: 10/01/2009
• Est. Priority Date: 09/20/2006
• Status: Active Grant

• Current Assignee: Hyaxiom Incorporated
• Original Assignee: UTC Power Corporation (Raytheon Technologies Corporation d/b/a RTX)
• Inventors: Assarabowski, Richard J., Hildreth, Derek, Kocum, Francis, Preston, John L. JR., Grasso, Albert P.
• Granted Patent: US 8,206,490 B2
• Time in Patent Office: Days
• US Class Current: 429/412
• CPC Class Codes: B01D 2258/0208 from fuel cells
• CPC Class Codes: B01D 53/58 Ammonia
• CPC Class Codes: B01D 53/77 Liquid phase processes
• CPC Class Codes: C01B 2203/0233 the reforming step being a steam reforming step
• CPC Class Codes: C01B 2203/0415 Purification by absorption in liquids
• CPC Class Codes: C01B 2203/0465 Composition of the impurity
• CPC Class Codes: C01B 2203/066 with fuel cells
• CPC Class Codes: C01B 3/38 using catalysts
• CPC Class Codes: C01B 3/52 by contacting with liquids; Regeneration of used liquids C01B3/508 takes precedence
• CPC Class Codes: H01M 8/0618 Reforming processes, e.g. autothermal, partial oxidation or steam reforming
• CPC Class Codes: H01M 8/0662 Treatment of gaseous reactants or gaseous residues, e.g. cleaning
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A separator scrubber (58) and isolation loop (78) decontaminates a fuel reactant stream of a fuel cell (12). Water passes over surfaces of an ammonia dissolving means (61) within the scrubber (58) while the fuel reactant stream simultaneously passes over the surfaces to remove contaminants from the fuel reactant into the water. An accumulator (68) collects the separated contaminants and water, and an isolation loop pump (84) directs flow of the separated contaminant stream through the isolation loop (78). A heat exchanger (86) and an ion exchange bed (88) modify the heat of, and remove contaminants from, the separated contaminant stream, and the isolation loop (78) directs the decontaminated stream back onto the packed bed (62)-. Separating contaminants from the fuel reactant stream and then isolating and concentrating the separated contaminants within the ion exchange bed (88) minimizes cost and maintenance requirements.

Claims

1. A contaminant separator and isolation loop (10) for a fuel reactant stream of a fuel cell (12), comprising:

a. a separator scrubber (58) secured in fluid communication with a fuel reactant inlet line (26) of the fuel cell (12), the separator scrubber (58) including an ammonia dissolving means (61) disposed within a scrubber container (64) of the separator scrubber (58) for dissolving ammonia from the fuel reactant stream into a liquid separated contaminant stream within the separator scrubber (58);

a water discharge (66) secured adjacent the ammonia dissolving means (61) and configured to discharge water to flow through the ammonia dissolving means (61);

a fuel reactant discharge (60) secured adjacent the ammonia dissolving means (61) and configured to discharge the fuel reactant to flow through the ammonia dissolving means (61);

an accumulator (68) secured in fluid communication with the ammonia dissolving means (61);

a scrubber fuel outlet (98) secured within the scrubber container (64) and configured to direct flow of the fuel reactant from the ammonia dissolving means (61) and from the scrubber separator (58) back into the fuel reactant inlet line (26); and

,

b. an isolation loop (78) secured in fluid communication with the separator scrubber (58), the isolation loop (78) including a loop conduit (80) configured to direct a separated contaminant stream out of the accumulator (68);

an isolation loop pump means (84) secured in fluid communication with the loop conduit (80) for pumping the separated contaminant stream through the loop conduit (80);

an isolation loop heat exchanger (86) secured in heat exchange relationship with the loop conduit (80) configured to transfer thermal energy with the separated contaminant stream within the loop conduit (80);

an ion exchange bed (88) secured in fluid communication with the loop conduit (80) configured to remove contaminants from the separated contaminant stream within the loop conduit (80); and

a loop conduit return line (90) secured in fluid communication between an outlet (92) of the ion exchange bed (88) and the water discharge (66) within the separator scrubber (58) configured to direct flow of the de-contaminated stream from the ion exchange bed (88) back into the separator scrubber (58).

2. The contaminant separator and isolation loop (10) for a fuel reactant stream of claim 1, further comprising a carbon dioxide vent bypass line (104) secured between an outlet (92) of the ion exchange bed (88) and the loop conduit return line (90) configured to selectively vent carbon dioxide out of the ion exchange bed (88).

3. The contaminant separator and isolation loop (10) for a fuel reactant stream of claim 1, further comprising a mist eliminator (102) secured adjacent the scrubber fuel outlet (98) configured to restrict passage of any water droplets out of the separator scrubber (58) within the fuel reactant stream.

4. The contaminant separator and isolation loop (10) for a fuel reactant stream of claim 1, further comprising a fresh water supply (70) secured in fluid communication with the scrubber container (64) and with a fresh water inlet valve (74) configured to selectively direct the fresh water into the scrubber container (64).

5. The contaminant separator and isolation loop (10) for a fuel reactant stream of claim 1, further comprising an overflow vent (76) secured in fluid communication with the scrubber container (64) configured to selectively direct excess water out of the scrubber (58).

6. The contaminant separator and isolation loop (10) for a fuel reactant stream of claim 1, wherein the ammonia dissolving means (61) comprises a packed bed (62) of a high surface area medium.

7. The contaminant separator and isolation loop (10) for a fuel reactant stream of claim 1, further comprising controller means (96) secured in communication with the fuel reactant stream adjacent the scrubber fuel outlet (98) for sensing information from the fuel reactant stream and for controlling the isolation loop (78) in response to the sensed information.

8. A contaminant separator (58) and isolation loop (78) for removing contaminants from a fuel reactant stream passing within a fuel reactant inlet line (26) from a fuel reformer means (50) for reforming a hydrogen containing fuel into the fuel reactant stream, the contaminant separator (58) and isolation loop (78) comprising:

a. a separator scrubber (58) secured in fluid communication with the fuel reactant inlet line (26), the separator scrubber (58) including an ammonia dissolving means (61) disposed within a scrubber container (64) of the separator scrubber (58) for dissolving ammonia from the fuel reactant stream into a liquid separated contaminant stream within the separator scrubber (58);

a water discharge (66) secured adjacent the ammonia dissolving means (61) and configured to discharge water to flow through the ammonia dissolving means (61);

a fuel reactant discharge (60) secured adjacent the ammonia dissolving means (61) and configured to direct the fuel reactant stream from the reformer means (50) to flow through the ammonia dissolving means (61);

an accumulator (68) secured in fluid communication with the ammonia dissolving means (61);

a scrubber fuel outlet (98) secured within the scrubber container (64) and configured to direct flow of the fuel reactant from the ammonia dissolving means (61) and from the scrubber separator (58) back into the fuel reactant inlet line (26); and

,

b. an isolation loop (78) secured in fluid communication with the separator scrubber (58), the isolation loop (78) including a loop conduit (80) configured to direct the separated contaminant stream out of the accumulator (68);

an isolation loop pump means (84) secured in fluid communication with the loop conduit (80) for pumping the separated contaminant stream through the loop conduit (80);

an isolation loop heat exchanger (86) secured in heat exchange relationship with the loop conduit (80) configured to transfer thermal energy with the separated contaminant stream within the loop conduit (80);

an ion exchange bed (88) secured in fluid communication with the loop conduit (80) configured to remove contaminants from the separated contaminant stream within the loop conduit (80); and

a loop conduit return line (90) secured in fluid communication between an outlet (92) of the ion exchange bed (88) and the water discharge (66) within the separator scrubber (58) configured to direct flow of the de-contaminated stream from the ion exchange bed (88) back into the separator scrubber (58).

9. The contaminant separator and isolation loop (10) for a fuel reactant stream of claim 8, further comprising a carbon dioxide vent bypass line (104) secured between an outlet (92) of the ion exchange bed (88) and the loop conduit return line (90) configured to selectively vent carbon dioxide out of the ion exchange bed (88).

10. The contaminant separator and isolation loop (10) for a fuel reactant stream of claim 8, further comprising a mist eliminator (102) secured adjacent the scrubber fuel outlet (98) configured to restrict passage of any water droplets out of the separator scrubber (58) within the fuel reactant stream.

11. The contaminant separator and isolation loop (10) for a fuel reactant stream of claim 8, further comprising a fresh water supply (70) secured in fluid communication with the scrubber container (64) and with a fresh water inlet valve (74) configured to selectively direct the fresh water into the scrubber container (64).

12. The contaminant separator and isolation loop (10) for a fuel reactant stream of claim 8, further comprising an overflow vent (76) secured in fluid communication with the scrubber container (64) configured to selectively direct excess water out of the scrubber (58).

13. The contaminant separator and isolation loop (10) for a fuel reactant stream of claim 8, wherein the ammonia dissolving means (61) comprises a packed bed (62) of a high surface area medium.

14. The contaminant separator and isolation loop (10) for a fuel reactant stream of claim 8, further comprising controller means (96) secured in communication with the fuel reactant stream adjacent the scrubber fuel outlet (98) for sensing information from the fuel reactant stream and for controlling the isolation loop (78) in response to the sensed information.

15. A method of decontaminating a fuel reactant stream for a fuel cell (12), comprising the steps of:

a. flowing the fuel reactant stream through an ammonia dissolving means (61) for dissolving ammonia from the fuel reactant stream into a liquid contaminant stream within a separator scrubber (58) while simultaneously flowing water through the ammonia dissolving means (61) to separate contaminants from the fuel reactant stream into the water;

b. accumulating the contaminated water from the packed bed within an accumulator (68);

c. circulating the water and contaminants as a separated contaminant stream from the accumulator (68) through an isolation loop (78);

d. modifying a temperature of the separated contaminant stream within an isolation loop heat exchanger (86);

e. removing the contaminants from the contaminated stream within an isolation loop ion exchange bed (88); and

,

f. then, circulating the decontaminated stream from the isolation loop (78) back through the ammonia dissolving means (61).

16. The method of claim 15 comprising the further step of adding an ammonia solubility enhancing reagent to the separated contaminant stream.

17. The method of claim 15 comprising the further step of replacing the ion exchange bed (88) at predetermined time intervals.

18. The method of claim 15 comprising the further step of sizing the ion exchange bed to be replaced at predetermined time intervals.