NOVELTY - Hydrogen generating apparatus comprises an inner vessel (180) having a longitudinal axis (5), sides, a first end (90), and an opposite second end (80); a core gas conduit (190) located outside the inner vessel and distributed at the longitudinal axis; pre-reforming zones (200); a fuel manifold (210); an inner feed plenum (240); an outer feed manifold (35); a flue gas manifold (230) on the feed manifold; and an air preheating zone (130).    USE - Used for generating hydrogen from a feed stream for use in conjunction with a fuel cell (claimed).    ADVANTAGE - The apparatus improves the overall heat balance, prevents the hot spots from forming, extends the life of the partial oxidation catalyst, responds quickly to transient fluctuations in the power demand of a fuel cell, minimizes the overall size of the unit while minimizing the heat loss of the pre-reformer to the environment and from the secondary reforming zone to the pre-reforming zone, and converts a fuel to hydrogen in a small volume while minimizing heat losses and providing safe way to contain a partial oxidation reaction occurring at elevated temperature. It provides improved hydrogen purity of the hydrogen product of the fuel processor, and improved overall integrated fuel processor and fuel cell efficiency.    DETAILED DESCRIPTION - The compact hydrogen generating apparatus comprises an inner vessel having a longitudinal axis, sides, a first end, and an opposite second end; a core gas conduit located outside the inner vessel and radially distributed at the longitudinal axis; pre-reforming zones having an annular pre-reforming catalyst zones (220) containing pre-reforming catalysts; a fuel manifold having a fuel inlet in fluid communication; an inner feed plenum on the first end of the inner vessel in fluid communication with the mixing zone (135) and terminal end of each annular pre-reforming catalyst zone; an outer feed manifold further distanced from the second end of the inner vessel also partially defining a sealed effluent plenum zone (205) enclosing each pre-reforming catalyst zone and inner vessel; a flue gas manifold on the feed manifold; and an air preheating zone. The inner vessel has a mixing zone, an oxidation zone (140), and a second reforming zone. It has a layer of insulation (155) surrounding the sides of the inner vessel. The core gas conduit has an interior passage, and a catalytic combustion zone (195) in a portion of the interior passage. The pre-reforming catalyst zones have a terminal end and an annular inlet surface. They are located annularly surrounding a portion of the core gas conduit in thermal communication. The combustion zone is adjacent the terminal end. The core gas conduit extends through the pre-reforming catalyst zone beyond the terminal end and beyond the annular inlet surface of the annular pre-reforming catalyst zone. It also extends through the inner feed plenum to the fuel manifold. The fuel manifold is located on the inner feed plenum. The interior passage of the core gas conduit is in fluid communication with the fuel manifold. The sealed effluent plenum zone is in fluid communication with an effluent outlet (60). The outer feed manifold is in fluid communication with a feed inlet (30) and annular inlet surface of each pre-reforming catalyst zone. The flue gas manifold has a flue gas outlet (70) in fluid communication with the core gas conduit extending through the outer feed manifold to the flue gas manifold. The flue gas manifold is in fluid communication with the interior passage. The air-preheating zone is in fluid communication with an air inlet (50), an inner feed plenum, and a preheater outlet. The upper reforming zone is located on the oxidation zone. The oxidation zone is located on the secondary reforming zone (150). The mixing zone is in fluid communication with the oxidation zone. The oxidation zone is in fluid communication with the secondary reforming zone.    DESCRIPTION OF DRAWING(S) - The figure is a front elevational view of a fuel processor reactor with integrated pre-reforming zone.    Longitudinal axis (5)    Compact hydrogen generating apparatus (20)    Feed inlet (30)    Outer feed manifold (35)    Air inlet (50)    Effluent outlet (60)    Flue gas outlet (70)    Opposite second end (80)    First end (90)    Air preheating zone (130)    Mixing zone (135)    Oxidation zone (140)    Secondary reforming zone (150)    Layer of insulation (155)    Inner vessel (180)    Core gas conduit (190)    Catalytic combustion zone (195)    Pre-reforming zones (200)    Sealed effluent plenum zone (205)    Fuel manifold (210)    Pre-reforming catalyst zones (220)    Flue gas manifold (230)    Inner feed plenum (240)