NOVELTY - A fuel processor (15) has a reformer (32) having reformer chambers (I, II) (103a-103c), a heater (30) for providing heat to the reformer, and a housing (152) having a set of housing walls for providing external mechanical protection to the reformer and heater. One of the chambers (I) has an inlet (A1) for receiving fuel and producing hydrogen from the fuel, and an outlet (A2) for ejecting hydrogen and unprocessed fuel. The other chamber (II) has an inlet (B1) for receiving fuel from the first chamber (I) and producing hydrogen, and an outlet (B2) for ejecting hydrogen. Fuel flows through the first chamber (I) from the inlet (A1) to the outlet (A2) in a specific direction.    USE - Used for producing hydrogen from fuel (claimed) used for a portable fuel cell system such as a polymer-electrolyte membrane (PEM) fuel cell used for portable electronic device.    ADVANTAGE - The fuel processor is compact to suit portable application, and prevents overheating of catalyst bed internals and hotspots.    DETAILED DESCRIPTION - A fuel processor (15) has a reformer (32) having reformer chambers (I, II) (103a-103c), a heater (30) for providing heat to the reformer, and a housing (152) having a set of housing walls for providing external mechanical protection to the reformer and the heater. The reformer chamber (I) has an inlet (A1) for receiving fuel and containing catalyst (102) which processes the fuel to produce hydrogen, and an outlet (A2) for ejecting hydrogen and unprocessed fuel from chamber (I). The reformer chamber (II) has an inlet (B1) for receiving at least one portion of the fuel from chamber (I) and containing a catalyst (104) for processing the portion of the fuel to produce hydrogen, and an outlet (B2) for ejecting hydrogen from chamber (II). The fuel flows through chamber (I) from inlet (A1) to outlet (A2) in a direction parallel to fuel flow direction through the chamber (II) from inlet (B1) to outlet (B2).    An INDEPENDENT CLAIM is included for the production of hydrogen in the fuel processor.    DESCRIPTION OF DRAWING(S) - The figures show a top perspective view and a cross-sectional front view of the fuel processor.    Fuel processor (15)    Heater (30)    Reformer (32)    Catalysts (102,104)    Reformer chambers (103a-103c)    Housing (152)