TECHNOLOGY FOCUS - INORGANIC CHEMISTRY - Preferred Reactor: The reactor further includes a third zone adjacent the second zone and a fourth zone adjacent the third zone, the flow path continuing through the zones in the same general direction. The zones are generally spherical and the flow directions are radially away from the first zone; or are hemispherical and the flow directions are radially away from a spherical portion of the first zone; or are cylindrical and the flow directions are radially or axially away from the first zone. Partitions separate the zones and have spaced openings to permit flow of the reaction stream. The reactor includes a partial oxidation reaction vessel located in the first zone, with the number, size and spacing of the partition openings being selected to control the flow rate and uniformity of the reaction stream, and the partition being constructed of material composition, thickness and finish to assist in controlling heat transfer between the vessel and the second zone. The reaction stream contains a partially oxidized hydrocarbon and hydrogen gas and the second, third or fourth zones contain a catalyst. The axial ends of the zones have a thermally insulating unit. The second zone contains a catalyst for steam reforming, the third zone contains a catalyst for high-temperature shift reaction and the fourth zone contains a catalyst for a low-temperature shift reaction in the reaction stream. The partitions are screen mesh. There is a device in the second, third and/or fourth zones for heat exchange with the reactant feed stream, the heat exchange being regulated so that a desired thermal gradient is maintained in the catalysts. The reactor further includes a device for flowing oxygen into the first zone, a device for flowing fuel to be oxidized to the first zone and a unit for cooperating these two flow devices. The fuel is gaseous hydrocarbon which is delivered from a pressurized container and the product gas is collected in a collection zone. The second, third and fourth zones are nested around the first zone.