Flexible, High-Efficiency Fuel Reforming in a Solid Oxide Fuel Cell System

An SOFC stack system including a reformer and fuel flow arrangement permitting optimized fuel reforming at all power load levels between 0% and 100%. A portion of the anode tail gas is combined with fresh air and fuel. The mixture is sent to a main reformer configured for endothermic reforming. Reformate is sent through a hydrocarbon cracker that breaks any hydrocarbons in the reformate into methane before the reformate enters the stack. At 100% load, there is no reforming in the main reformer; all of the fuel is internally reformed within the stack. At 0% load, all of the fuel is reformed in the main reformer. At loads between 0% and 100%, reforming is a mixture of endothermic reforming in the main reformer and internal reforming of methane within the stack. This strategy allows highest fuel processing efficiencies available through the full range of stack operation.