A catalytic reactor is provided comprising a plurality of first flow channels including a catalyst for a first reaction; a plurality of second flow channels arranged alternately with the first flow channels; adjacent first and second flow channels being separated by a divider plate (13a, 13b), and a distributed temperature sensor such as an optical fibre cable (19). The distributed temperature sensor may be located within the divider plate, or within one or 10 more of the flow channels.

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 situation 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.