A reactor for the production of hydrogen from at least one selected from the group consisting of natural gas, propane, liquefied petroleum gas, alcohols, naphtha, hydrocarbon fuels and mixtures thereof, said reactor comprising:
- a unitary shell assembly having an inlet and an outlet;
- a flow path extending within said shell assembly from said inlet to said outlet, said flow path including a convectively-heated catalytic steam reformer and a convectively-cooled water gas shift reactor;
- wherein the steam reformer comprises a steam reforming catalyst;
- wherein the water-gas shift reactor comprises a water-gas shift catalyst;
- and
- wherein the steam reformer is upstream of the water-gas shift reactor.