A multiple adiabatic
bed reforming apparatus and process are disclosed in which stage-wise
combustion, in combination with multiple reforming chambers with catalyst, utilize co-flow and cross-flow under laminar flow conditions, to provide a reformer suitable for smaller production situations as well as large scale production. A passive stage by stage
fuel distribution network suitable for low pressure fuel is incorporated and the resistances in successive
fuel distribution lines control the amount of fuel delivered to each
combustion stage. The
fuel distribution system allows relatively constant fuel and air flow during turn up or turn down conditions. High efficiency is achieved by capturing heat from reforming
syngas product to preheat gases before entering the reformer. Conditions that would produce unwanted coking or
metal dusting are also eliminated or localized to locations within the apparatus outside the heat exchangers, but which locations can be cost effectively protected. Also, a
chemical reactor is disclosed and which has a core composed of a stack of
metal plates that are
diffusion bonded in face-to-face relationship. A plurality of reaction zones are located within the core, as are a plurality of catalyst receiving zones, and both the reaction zones and the catalyst receiving zones are defined by respective aligned apertures in the plates. First and second channel arrangements are provided in the plates for transporting first and second reactants to reaction zones. Portions of the first channel arrangement that interconnect the reaction zones are formed as heat exchange channels. A third channel arrangement is provided in the plates for transporting a third reactant to catalyst receiving zones. Portions of the third channel arrangement are formed as heat exchange channels in proximity to the heat exchange channels of the first channel arrangement.