High efficiency fuel cell system with hydrogen and syngas export

A method comprising:

• operating a fuel cell system that comprises:
• a first topping fuel cell module comprising a first topping anode portion configured to output a first topping anode exhaust comprising hydrogen, and a first topping cathode portion configured to output a first topping cathode exhaust,
• a second topping fuel cell module comprising a second topping anode portion configured to output a second topping anode exhaust comprising hydrogen, and a second topping cathode portion configured to output a second topping cathode exhaust,
• at least one bottoming fuel cell module comprising a bottoming anode portion configured to output a bottoming anode exhaust, and a bottoming cathode portion configured to output a bottoming cathode exhaust, and
• an electrochemical hydrogen separation unit;
• wherein the step of operating the fuel cell system comprises:
• at the electrochemical hydrogen separation unit, receiving at least a portion of the first topping anode exhaust from the first topping fuel cell module and the second topping anode exhaust from the second topping fuel cell module, outputting a hydrogen-rich stream, and outputting a CO2-rich stream;
• and
• at the bottoming anode portion, receiving the CO2-rich stream from the electrochemical hydrogen separation unit.

A fuel cell system comprising:

• a first topping fuel cell module comprising a first topping anode portion configured to output a first topping anode exhaust comprising CO2 and hydrogen, and a first topping cathode portion configured to output a first topping cathode exhaust;
• a second topping fuel cell module comprising a second topping anode portion configured to output a second topping anode exhaust comprising CO2 and hydrogen, and a second topping cathode portion configured to output a second topping cathode exhaust;
• at least one bottoming fuel cell module comprising a bottoming anode portion configured to receive the first topping anode exhaust and the second topping anode exhaust and to output a bottoming anode exhaust, and a bottoming cathode portion configured to output a bottoming cathode exhaust;
• and
• a CO2 separation assembly configured to receive the bottoming anode exhaust, to output a hydrogen-rich stream, and to output a CO2-rich stream.

A method comprising:

• operating a fuel cell system that comprises:
• a first topping fuel cell module comprising a first topping anode portion configured to output a first topping anode exhaust comprising CO2 and hydrogen, and a first topping cathode portion configured to output a first topping cathode exhaust,
• a second topping fuel cell module comprising a second topping anode portion configured to output a second topping anode exhaust comprising CO2 and hydrogen, and a second topping cathode portion configured to output a second topping cathode exhaust,
• at least one bottoming fuel cell module comprising a bottoming anode portion configured to receive the first topping anode exhaust and the second topping anode exhaust and to output a bottoming anode exhaust, and a bottoming cathode portion configured to output a bottoming cathode exhaust, and
• a CO2 separation assembly;
• wherein the step of operating the fuel cell system comprises, at the CO2 separation assembly, receiving the bottoming anode exhaust from the at least one bottoming fuel cell module, outputting a hydrogen-rich stream, and outputting a CO2-rich stream.