NOVELTY - The fuel processing system (30) comprises a reformer secured in fluid communication through a fuel feed line with a fuel source (24) and secured in fluid communication with a fuel inlet line (20), a steam generator secured in fluid communication between a combustible fuel inlet and the reformer, a reformer-oxidant source secured in fluid communication with a reformer-oxidant inlet, a desulfurizer secured to the fuel feed line between the fuel source and the reformer, a desulfurized-fuel holding tank, a hydrogen containing gas source and a hydrogen vent-gas line.    USE - The fuel processing system is useful for a fuel cell power plant operating on a sulfur-containing fuel, where the: power plant is useful for generating electrical current from a hydrogen-rich reformate fuel stream and an oxidant stream (claimed) and in transportation vehicles, portable power plants, or as stationary power plants; and the fuel is liquid or gaseous fuels such as gasoline, diesel fuel and hydrogen.    ADVANTAGE - The system is compact, ensures safe, rapid and effective processing of the fuel, and enables virtually instantaneous start-up of the power plant by directing stored desulfurized fuel from the holding tank to the reformer while the desulfurizer is warming up.    DETAILED DESCRIPTION - The fuel processing system (30) comprises a reformer secured in fluid communication through a fuel feed line with a fuel source (24) for reforming the fuel into the hydrogen-rich reformate fuel stream and secured in fluid communication with a fuel inlet line (20) for directing the fuel stream into the fuel cell (12), a steam generator secured in fluid communication between a combustible fuel inlet and the reformer for supplying steam to the reformer, a reformer-oxidant source secured in fluid communication with a reformer-oxidant inlet for directing an oxidant to the reformer, a desulfurizer secured to the fuel feed line between the fuel source and the reformer and configured to direct the fuel through the desulfurizer, a desulfurized-fuel holding tank secured in fluid communication with the fuel downstream from the desulfurizer and upstream from the reformer and configured to store the desulfurized fuel and to selectively direct flow of the desulfurized fuel into the reformer, a hydrogen containing gas source secured in fluid communication with the desulfurizer for selectively directing flow of a hydrogen containing gas into the desulfurizer, and a hydrogen vent-gas line secured in fluid communication between the desulfurized-fuel holding tank and one or both of the combustible fuel inlet of the steam generator or the reformer-oxidant inlet, and configured for directing flow of hydrogen vent-gas out of the holding tank and into the reformer or the steam generator. The hydrogen gas source is a return line secured in fluid communication between the fuel inlet line downstream from the reformer and the desulfurizer. The hydrogen gas source is a hydrogen gas container secured in fluid communication with the desulfurizer. The combustible fuel inlet of the steam generator is secured in fluid communication with a fuel exhaust line (22) configured to direct unused fuel out of the fuel cell. An INDEPENDENT CLAIM is included for a method of processing a sulfur-containing fuel for a fuel cell power plant.    DESCRIPTION OF DRAWING(S) - The drawing shows a simplified schematic representation of a fuel cell power plant including a fuel processing system.    Fuel cell (12)    Fuel inlet line (20)    Fuel exhaust line (22)    Fuel source (24)    Fuel processing system. (30)