TECHNOLOGY FOCUS - MECHANICAL ENGINEERING - Preferred Components: A set of heat exchange tubes (30, 86, 89) communicates between the reaction tubes of the two reaction zones to cool the subsidiary intermediate product streams to promote temperatures within the second reaction zone that favor hydrogen production via the water-gas shift reaction. The heat exchange tubes are of helical configuration and are positioned n the coaxial arrangement to form a third coil-like structure. The first coil-like structure, the second coil-like structure and the third coil-like structure positioned within the housing in a coaxial relationship. The housing is cylindrical and has coaxial, annular chambers (90, 92, 94), and thermal insulation (96, 98, 100, 102) thermally insulates the annular chambers. A heater supplies heat to the first reaction zone to drive the reforming of the feed stream. The heater is formed of burners (84) firing into the first of the annular chambers. The first and the second of the annular chambers are in flow communication so that a flow of air as the heat exchange fluid is preheated and is able to pass from the second to the first of the annular chambers to support combustion, thus to produce combustion products. The housing has an exhaust to discharge the combustion products. The reactor further comprises a hydrocarbon feed inlet to receive a hydrocarbon feed; at least one feed water inlet to receive boiler feed water; and a steam generator formed of a set of boiler feed water tubes of helical configuration and positioned, in the coaxial arrangement to form a fifth coil-like structure located within the third annular chamber. A sulfur treatment canister (14) is interposed between the reaction feed inlet and the inner tubes of the tube in tube heat exchanger such that the hydrocarbon feed is treated prior to being introduced into the first reaction zone. The housing has first and second header chambers (112, 124) bounding opposite ends of the first, second and third of the annular chambers. A set of cylindrical air induction baffles is located within the second annular chamber and forming sub-chambers. The reactor further comprises a cooler (42) to cool the subsidiary synthesis gas product streams.    TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Components: The feed stream is a hydrocarbon and steam containing feed stream. The catalyst is a reforming catalyst (27) located within the reaction tubes of first reaction zone to form subsidiary intermediate product streams containing hydrogen and carbon monoxide and a water-gas shift catalyst (35) is located within the reaction tubes of second reaction zone to increase the hydrogen content in the product stream over that of the intermediate product stream.