Patent ID: 7858214

Claim:
A method for operating a solid oxide fuel cell assembly including a hydrocarbon reformer, a fuel cell stack having an anode inlet and an anode outlet, and an anode tail gas cooler, comprising the steps of: providing a reformate fuel from said hydrocarbon reformer to said anode inlet of fuel cell stack; diverting a first portion of anode tail gas from said anode outlet of fuel cell stack to said anode tail gas cooler and cooling said first portion of anode tail gas; combining cooled first portion of anode tail gas with said reformate fuel downstream of said hydrocarbon reformer and upstream of said anode inlet of fuel cell stack; providing a clean-up catalyst upstream of said anode tail gas cooler and downstream of said anode outlet of fuel cell stack, said clean-up catalyst reduces said first portion of anode tail gas to methane, H2, and CO; providing a primary controller controlling the flow of a first hydrocarbon fuel to said hydrocarbon reformer; providing a secondary controller controlling the flow of a second hydrocarbon fuel to combine with said first portion of anode tail gas upstream of said clean-up catalyst and downstream of said anode outlet of fuel cell; and further comprising the step of providing a non-recirculated hydrocarbon fuel to said reformer.