Patent ID: 8007943

Claim:
A fuel cell system, comprising: a first fuel cell stack having a fuel or oxidant gas inlet operable to receive an amount of fuel or oxidant gas and a fuel or oxidant exhaust gas outlet operable to exhaust an amount of fuel or oxidant exhaust gas; a second fuel cell stack having a fuel or oxidant gas inlet operable to receive the fuel or oxidant exhaust gas from the first fuel cell stack and a fuel or oxidant exhaust gas outlet operable to exhaust an amount of fuel or oxidant exhaust gas; and a gas recirculation system in fluid communication with the first and second fuel cell stacks, wherein the gas recirculation system includes a gas recirculation device that operates to increase the pressure of a recirculation gas; wherein the gas recirculation device is selected from the group consisting of a pump, ejector, compressor and combinations thereof; and wherein the gas recirculation system is operable to receive the fuel or oxidant exhaust gas from the fuel or oxidant exhaust gas outlet of the second fuel cell stack and reintroduce the fuel or oxidant exhaust gas into the fuel or oxidant gas inlet of the first fuel cell stack; wherein the fuel or oxidant exhaust gas and the fuel or oxidant gas are combined in the gas recirculation device prior to being reintroduced into the first fuel cell stack, said gas recirculation device being operable to increase the pressure of the exhaust gas that enters the gas recirculation system; wherein the exhaust gas has a higher moisture level than the fuel or oxidant gas.