High-efficiency dual-stack molten carbonate fuel cell system

• US 8,062,799 B2
• Filed: 08/19/2008
• Issued: 11/22/2011
• Est. Priority Date: 08/19/2008
• Status: Active Grant

• Current Assignee: Fuelcell Energy Ltd.
• Original Assignee: Fuelcell Energy Ltd.
• Inventors: Ghezel-Ayagh, Hossein, Farooque, Mohammad, Jahnke, Fred C.
• Primary Examiner(s): HYEON, HAE M
• Application Number:
  US12/194,272
• Publication Number:
  US 20100047641A1
• Time in Patent Office: 1,190 Days
• Field of Search: 429/415, 429/413, 429/423, 429/425
• US Class Current: 429/415
• CPC Class Codes: H01M 2008/147 Fuel cells with molten carbonates
• CPC Class Codes: H01M 8/04291 Arrangements for managing water in solid electrolyte fuel cell systems H01M8/04119 takes precedence
• CPC Class Codes: H01M 8/04701 Temperature
• CPC Class Codes: H01M 8/04753 of fuel cell reactants
• CPC Class Codes: H01M 8/0612 from carbon-containing material
• CPC Class Codes: H01M 8/0637 Direct internal reforming at the anode of the fuel cell
• CPC Class Codes: H01M 8/249 comprising two or more groupings of fuel cells, e.g. modular assemblies
• CPC Class Codes: Y02E 60/50 Fuel cells

Abstract

A dual stack fuel cell system comprising a first fuel cell stack comprising a first anode side, adapted to receive fuel and to output a first anode exhaust, and a first cathode side, a second fuel cell stack comprising a second anode side, adapted to receive processed anode exhaust derived from the first anode exhaust and to output a second anode exhaust, and a second cathode side, adapted to receive oxidant gas and to output a first cathode exhaust, wherein the first cathode side receives at least the first cathode exhaust outputted from the second cathode side; and wherein the first fuel cell stack includes indirect internal reforming and the second fuel cell stack may not include any indirect internal reforming.

Claims

1. A dual stack fuel cell system comprising:

a first fuel cell stack comprising a first anode side, adapted to receive fuel and to output a first anode exhaust, and a first cathode side;

a second fuel cell stack comprising a second anode side, adapted to receive processed anode exhaust derived from said first anode exhaust and to output a second anode exhaust, and a second cathode side, adapted to receive oxidant gas and to output a first cathode exhaust;

wherein said first cathode side receives at least said cathode exhaust outputted from said second cathode side; and

wherein said first fuel cell stack includes a first indirect internal reformer and said second fuel cell stack includes a second indirect internal reformer, said fuel cell system further comprising a reformer bypass line for bypassing a portion or all of said processed anode exhaust around said second indirect internal reformer to an anode compartment of said second anode side.

2. The dual stack fuel cell system in accordance with claim 1, wherein said first fuel cell stack and said second fuel cell stack further include direct internal reforming.

3. The dual stack fuel cell system in accordance with claim 1, further comprising at least one of:

a cooling assembly including at least one cooling member for cooling said first anode exhaust;

and

a water recovery assembly for recovering water from said first anode exhaust;

wherein said processed anode exhaust is derived by at least one of cooling said first anode exhaust in said cooling assembly, and recovering water from said first anode exhaust in said water recovery assembly.

4. The dual stack fuel cell system in accordance with claim 3, further comprising an oxidizer assembly adapted to receive said second anode exhaust and inlet air and to oxidize said second anode exhaust with said inlet air to produce oxidant gas.

5. The dual stack fuel cell system in accordance with claim 3, further comprising:

a reactor assembly including at least one of a shift reactor and a methanation reactor for converting carbon monoxide in said first anode exhaust to respectively at least one of methane and hydrogen;

wherein said processed anode exhaust is derived by at least one of cooling said first anode exhaust in said cooling assembly, reacting said first anode exhaust in said reactor assembly and recovering water from said first anode exhaust in said water recovery assembly.