Patent ID: 8142943

Claim:
A method of operating a fuel cell system, comprising: internally reforming a hydrocarbon fuel to form a reformed fuel in at least one fuel cell located in a middle portion of a fuel cell stack; generating electricity in the at least one fuel cell located in the middle portion of a fuel cell stack using the reformed fuel; providing a fuel exhaust stream from the at least one fuel cell located in the middle portion of the fuel cell stack into at least one fuel cell located in an end portion of the fuel cell stack; and generating electricity in the at least one fuel cell located in the end portion of the fuel cell stack using the fuel exhaust stream from the at least one fuel cell located in the middle portion of the fuel cell stack as a fuel; wherein the fuel cells located in the middle portion and the end portion of the fuel cell stack are arranged in a cascade configuration; and wherein the internally reforming step selectively cools the at least one fuel cell located in the middle portion of the fuel cell stack using a hydrocarbon reformation reaction.