High Temperature Fuel Cell System and Method of Operating the Same

1 . A method of operating a solid oxide fuel cell system, comprising:

operating the fuel cell system in a start-up mode by:

providing a hydrocarbon fuel and air into a catalytic partial oxidation reactor;

generating hydrogen in the catalytic partial oxidation reactor;

providing the generated hydrogen into a solid oxide fuel cell stack; and

stopping the generation of hydrogen in the catalytic partial oxidation reactor once the fuel cell stack reaches a predetermined operating temperature; and

operating the fuel cell system in a steady state operating mode to generate electricity after the fuel cell stack reaches a predetermined operating temperature.

2 . The method of claim 1 , wherein the predetermined operating temperature is a temperature at which oxidation of anode electrodes of solid oxide fuel cells in the solid oxide fuel cell stack is avoided.

3 . The method of claim 1 , further comprising heating the catalytic partial oxidation reactor during the start-up mode.

4 . The method of claim 1 , further comprising mixing the hydrocarbon fuel and air and providing the mixed hydrocarbon fuel and air into the catalytic partial oxidation reactor.

5 . The method of claim 1 , wherein the hydrocarbon fuel comprises methane or methane containing natural gas.

6 . The method of claim 1 , wherein the generated hydrogen is provided in the start-up mode from the catalytic partial oxidation reactor into the solid oxide fuel cell stack through a reformer.

7 . The method of claim 6 , wherein the generated hydrogen is provided in the start-up mode from the solid oxide fuel cell stack into a fuel heat exchanger.

8 . The method of claim 7 , wherein the generated hydrogen is provided in the start-up mode from the fuel heat exchanger into a combustor.

9 . The method of claim 1 , wherein the step of stopping the generation of hydrogen in the catalytic partial oxidation reactor comprises stopping operation of the catalytic partial oxidation reactor.

10 . The method of claim 1 , wherein operating the fuel cell system in a steady state operating mode comprises:

providing the hydrocarbon fuel and water vapor into a reformer;

reforming the hydrocarbon fuel in the reformer to form a hydrogen containing reaction product; and

providing the reaction product and air into the solid oxide fuel cell stack during the steady state operating mode of the stack.

11 . The method of claim 10 , wherein operating the fuel cell system in a steady state operating mode further comprises:

providing the hydrocarbon fuel into a fuel heat exchanger;

providing the hydrocarbon fuel from the fuel exchanger into the reformer;

providing the air into an air heat exchanger; and

providing the air from the air heat exchanger into the solid oxide fuel cell stack.

12 . The method of claim 11 , wherein operating the fuel cell system in a steady state operating mode further comprises:

providing an anode exhaust from the solid oxide fuel cell stack into the fuel heat exchanger to heat the hydrocarbon fuel;

providing at least a portion of the anode exhaust from the fuel heat exchanger into a combustor;

providing a cathode exhaust from the solid oxide fuel cell stack into the combustor; and

providing a combustor exhaust into the air heat exchanger to heat the air.

13 . The method of claim 1 , wherein operating the fuel cell system in a start-up mode further comprises:

providing the generated hydrogen from the catalytic partial oxidation reactor a reformer;

providing the generated hydrogen from the reformer into the solid oxide fuel cell stack;

providing the generated hydrogen from the solid oxide fuel cell stack into a fuel heat exchanger; and

providing the generated hydrogen from the fuel heat exchanger into a combustor.

14 . The method of claim 13 , wherein operating the fuel cell system in a steady state operating mode comprises:

providing the hydrocarbon fuel into a fuel heat exchanger;

providing the hydrocarbon fuel from the fuel exchanger into the reformer;

providing water vapor into the reformer;

reforming the hydrocarbon fuel in the reformer to form a hydrogen containing reaction product;

providing the reaction product into the solid oxide fuel cell stack;

providing the air into an air heat exchanger;

providing the air from the air heat exchanger into the solid oxide fuel cell stack;

providing an anode exhaust from the solid oxide fuel cell stack into the fuel heat exchanger to heat the hydrocarbon fuel;

providing at least a portion of the anode exhaust from the fuel heat exchanger into a combustor;

providing a cathode exhaust from the solid oxide fuel cell stack into the combustor; and

providing a combustor exhaust into the air heat exchanger to heat the air.