AUTOTHERMAL REFORMER

An autothermal reformer for converting a fuel into a reformate stream comprising hydrogen comprises (a) a closed vessel having a top end and a bottom end, the vessel comprising at least one insulation layer adjacent the interior surface of the vessel; (b) a first reactant manifold disposed within the vessel for receiving and distributing a first reactant stream, the first reactant manifold having a plurality of mixer tubes extending therefrom, each of the mixer tubes having an inlet end and an outlet end, the mixer tubes disposed in a separator member; and (c) a second reactant manifold disposed within the vessel for receiving and distributing a second reactant stream, the second reactant manifold comprising a plurality of injection tubes. Each of the injection tubes has an inlet end and an outlet end, extend through the first reactant manifold and are fluidly isolated therefrom. The outlet end of each of the plurality of injection tubes extends into the inlet end of one of the mixer tubes, thereby forming a gap between the outer wall of the injection tube and the inner wall of the mixer tube. Methods of operating the present autothermal reformer are also provided.