TECHNOLOGY FOCUS - MECHANICAL ENGINEERING - Preferred Component: The flow path includes a preheat section located upstream of the reformer section and an adiabatic water gas shift reactor section located downstream of the water gas shift reactor section. The preheat section includes a sulfur absorbent bed packing material. The steam reformer section and water gas shift reactor section are formed of an array of tubes (3). The flow path includes an inlet tube header (4) located upstream of the reformer section, and an outlet tube header (6) located downstream of the water gas shift reactor section. The interior of the tubes is provided with a catalyst in the form of a coating, a monolith, a loose packing of pellets, and/or extrudates. The exterior surface of the tube are twisted tubes, finned tubes, rifled tubes, plate fins, and/or loose packing material. Baffles (9) force a heat transfer medium flowing outside the tubes across the array of tubes in a direction normal to a longitudinal axis of the tubes. A catalytic burner heats at least one of a heating medium provided within the heating section and a cooling medium. The first catalyst (5) is resistant to poisoning by sulfur and molecular oxygen. The second catalyst (50) is resistant to poisoning by sulfur. The shell assembly (10) includes thermal expansion relief device, inlet(s) to the cooling section and outlet(s) for the cooling section.    TECHNOLOGY FOCUS - CHEMICAL ENGINEERING - Preferred Method: The hydrogen is produced by steam reforming the fuel using a catalyst comprising a catalytically active metal from group VIIIB metals, ruthenium, iridium, rhodium, platinum, and/or palladium at 4-18 atm. It is purified with a pressure swing adsorption system. No pretreatment of the fuel to remove at least one impurity from sulfur and/or molecular oxygen is carried out. The product exiting the high temperature water gas shift reaction is above 200 degrees C. The reforming produces carbon monoxide or at least one impurity or both.