NOVELTY - Hydrogen is generated by supplying a partial oxidation/steam reforming zone hydrocarbon-containing feedstock, air and steam, and steam as feed; maintaining the zone under partial oxidation/steam reforming conditions; cooling the reforming effluent stream by indirect heat exchange with a stream; and subjecting the cooled reforming effluent stream to purification unit operation.    USE - For generating hydrogen from hydrocarbon-containing feedstock.    ADVANTAGE - The inventive process has improved efficiency. It yields a hydrogen product of good quality and very low carbon monoxide concentration, provides favorable economics as compared to shipping and storage of hydrogen produced by a large-scale hydrogen plant. It is easily operated with minimal needs for technical sophistication and maintenance.    DETAILED DESCRIPTION - Generating hydrogen at a pressure of greater than or equal to400 kPa absolute comprises supplying a partial oxidation/steam reforming zone hydrocarbon-containing feedstock, air and steam, and steam as feed; maintaining the zone under partial oxidation/steam reforming conditions including the pressure to partially oxidize a portion of the feedstock to generate heat and to reform a portion of the feedstock to generate hydrogen, thus reforming effluent stream comprising hydrogen, carbon monoxide and carbon dioxide is provided; cooling the reforming effluent stream by indirect heat exchange with a stream containing liquid water to provide a steam-containing stream at greater than or equal to300degreesC, which is cycled to the partial oxidation/steam reforming zone where greater than or equal to40% of the steam in the feed mixture is produced by the indirect heat exchange; and subjecting the cooled reforming effluent stream to at least one purification unit operation. Free oxygen is provided in a mole ratio to carbon in the feedstock of 0.4:1 to 0.6:1 and steam is provided in a mole ratio to carbon in the feedstock of 4:1.    DESCRIPTION OF DRAWING(S) - The drawing shows a flow diagram of the inventive process.    Valve (204, 208, 214)    Heat exchanger (212)    Heat exchanger (216)    Autothermal reformer (222)