Autothermal reformer

An autothermal reformer for converting reactants comprising a fuel and an oxidant into a reformate stream comprising hydrogen, said reformer comprising:

• (a) a closed vessel, said vessel having a top end and a bottom end, said vessel comprising at least one insulation layer adjacent the interior surface of said vessel;
• (b) a first reactant manifold disposed within said vessel for receiving and distributing a first reactant stream comprising one of said fuel and said oxidant, said first reactant manifold having a plurality of mixer tubes extending therefrom, each of said mixer tubes having an inlet end and an outlet end, said mixer tubes disposed in a separator member;
• (c) a second reactant manifold disposed within said vessel for receiving and distributing a second reactant stream comprising the other of said fuel and said oxidant, said second reactant manifold comprising a plurality of injection tubes, each of said injection tubes having an inlet end and an outlet end, said injection tubes extending through said first reactant manifold and fluidly isolated therefrom;
• and
• (d) a reforming section disposed within said vessel for receiving and converting said first and second reactant streams to a reformate stream comprising hydrogen;
• wherein said outlet end of each of said plurality of injection tubes extends into said inlet end of one of said mixer tubes, thereby forming a gap between said outer wall of said injection tube and said inner wall of said mixer tube.