Compact counterflow fuel reformer

A catalytic reformer assembly for generating hydrogen-containing reformate from hydrocarbons, comprising:

• a reactor having a longitudinal axis and a longitudinal wall disposed about the axis, said reactor having a first axial end wall and a second axial end wall remote from the first axial end wall;
• a reforming chamber disposed in the reactor about the axis defining an inbound co-axial mixing chamber, the reforming chamber including an inner chamber wall adjacent the mixing chamber and an outer chamber wall adjacent the longitudinal wall of the reactor, the mixing chamber having an entrance end adjacent the first axial end wall and an exit end remotely opposite the entrance end proximate to second axial end wall, and the entrance end to the exit end defining a first flow direction for a fuel/air mixture disposed in the mixing chamber, and the reforming chamber being in downstream fluid communication from the mixing chamber;
• an air inlet duct disposed in a wall of the reactor to provide a supply of air to the mixing chamber;
• a plenum defined between the longitudinal wall of the reactor and the outer chamber wall therebetween and being an intermediate fluid conduit for air supplied from the air inlet duct and delivered to a passage at the entrance end of the mixing chamber defining a second flow direction;
• a reforming catalyst disposed in the reforming chamber such that reformate issues from the reforming catalyst in the reforming chamber defining a third flow direction;
• and
• a reformate outlet duct being in fluid communication to the reformate chamber, the reformate outlet duct being a fluid conduit for reformate to exit the reforming chamber;
• wherein air flows through the air inlet duct and into the plenum in the second flow direction toward the first axial end wall, and a fuel/air mixture configured in the mixing chamber flows in the first flow direction opposite the second flow direction, and the reformate flows in the third flow direction in the reforming chamber in the same direction as the second flow direction such that the reformate warms the reformate chamber walls to directly transfer heat to warm the air flowing through the plenum toward the mixing chamber and the fuel/air mixture flowing through the mixing chamber toward the reformate chamber.