Fuel cell system including fuel exhaust processor and method of operating the same

A fuel cell system comprising:

• a hotbox;
• a fuel cell stack disposed in the hotbox;
• an anode tail gas oxidizer (ATO) disposed in the hotbox;
• a recycling conduit configured to receive anode exhaust from the fuel cell stack;
• a splitter fluidly connected to the recycling conduit;
• a low temperature shift reactor;
• a hydrogen separator comprising:
• a first hydrogen pump;
• a second hydrogen pump that is fluidly connected to the first hydrogen pump;
• and
• a third hydrogen pump that is fluidly connected to the second hydrogen pump;
• a supply conduit that fluidly connects an outlet of the splitter to the hydrogen separator;
• a first separator conduit fluidly connecting the splitter to the low temperature shift reactor;
• a second separator conduit fluidly connecting the low temperature shift reactor to the first hydrogen pump;
• a first return conduit that fluidly connects an outlet of the splitter to the fuel cell stack;
• a second return conduit that fluidly connects an outlet of the splitter or the separator conduit to the ATO;
• and
• a third return conduit that fluidly connects the separator conduit to the second return conduit.

A fuel cell system comprising:

• a first hotbox;
• a first fuel cell stack disposed in the first hotbox;
• a first anode tail gas oxidizer (ATO) disposed in the first hotbox;
• a second hotbox;
• a second fuel cell stack disposed in the second hotbox;
• a second anode tail gas oxidizer (ATO) disposed in the second hotbox;
• and
• a fuel exhaust processor configured to:
• receive anode exhaust from the first and second fuel cell stacks;
• output a first portion of the anode exhaust to the first and second fuel cell stacks;
• extract hydrogen from a second portion of the anode exhaust to form a first hydrogen stream, a second hydrogen stream, and a carbon dioxide stream;
• output the first hydrogen stream to the first and second fuel cell stacks;
• output the second hydrogen stream to the first and second ATO's;
• and
• output the carbon dioxide stream to a carbon dioxide storage device.

A fuel cell system comprising:

• a hotbox;
• a fuel cell stack disposed in the hotbox;
• an anode tail gas oxidizer (ATO) disposed in the hotbox;
• and
• a fuel exhaust processor fluidly connected to the hotbox and comprising:
• a first hydrogen pump configured to extract hydrogen from the anode exhaust received from the fuel cell stack;
• and
• a second hydrogen pump configured to extract hydrogen from anode exhaust output from the first hydrogen pump;
• wherein the first hydrogen pump and the second hydrogen pump output hydrogen to one or more components of the hotbox.