NOVELTY - A thermal reformer system comprises a planar assembly including a reformer zone (5); a combustion zone (6); an inlet reformate process fluid manifold (10); an outlet reformate process fluid manifold (20); an inlet combustion fluid manifold (30); an outlet combustion fluid manifold (40); and an inlet combustion fluid flow passage (31) connecting the inlet combustion fluid manifold and combustion zone.    USE - For producing hydrogen; particularly useful as hydrogen reformers fuelled by gaseous or liquid hydrocarbon fuels, organic fuels and hydrogen containing compounds such as ammonia; and to be integrated with pre and post reactors such as steam generation and water gas shift reactors to create a fuel processing system.    ADVANTAGE - The thermal reformer system includes the planar (sheet metal) construction designed such that reformate process gases flow from inlet manifolds inwards towards the higher temperature primary reactor zone, and the inward flowing gases and the outward flowing gases are in thermal contact, to enhance energy recuperation within the planar construction. Thus, the thermal reformer system has a planar geometry, heat exchanger type, modular reformer with integrated thermal energy recuperation. The reformer system integrates the thermal recuperative heat exchange area created by fluid passages within the planar assembly such that the outlet fluids transfer most of their thermal energy into the inlet fluids, and much of the recuperation occurs along outer edges of the assembly to minimize heat loss and insulation requirements. The apparatus minimizes combustion temperatures by dividing the combustion gas inlet manifold and passage into two parallel passages and by using a distributed combustion configuration. The planar geometry with integrated manifolds to support stacking of multiple modular reformer elements, provides flexibility in reformer capacity without major engineering designs.    DETAILED DESCRIPTION - The planar assembly includes an outlet combustion fluid flow passage (41) connecting the combustion zone and outlet combustion fluid manifold; an inlet reformate process fluid flow passage (11) connecting the inlet reformate process fluid manifold to the reformer zone; and an outlet reformate process fluid flow passage (21) connecting the outlet reformate process fluid manifold and the reformer zone. A primary reactor zone consisting of the reformer zone and combustion zone, is centrally located within the planar assembly. The thermal reformer system include several such planar assemblies stacked one above another, to provide a modular reformer assembly. The reformer zone and combustion zone are in thermal contact to promote transfer of combustion heat in the reformer zone to drive a reformation reaction.    DESCRIPTION OF DRAWING(S) - The figures show a cross sectional view of individual components of a modular reformer element, and a cross sectional view of inlet and outlet flow passages of the reformer element.    modular reformer element (2)    reformer zone (5)    combustion zone (6)    inlet reformate process fluid manifold (10)    inlet reformate process fluid flow passage (11)    outlet reformate process fluid manifold (20)    outlet reformate process fluid flow passage (21)    inlet combustion fluid manifold (30)    inlet combustion fluid flow passage (31)    outlet combustion fluid manifold (40)    outlet combustion fluid flow passage. (41)