An apparatus for processing hydrocarbon fuel (e.g., gasoline, kerosene, jet fuel, diesel and heating oil) to generate hydrogen (H.sub.2), which can be used in fuel cells, includes a desulfurization reactor for removing sulfur from the fuel; a catalytic reactor for forming a reformate from the fuel; and, optionally, a separator for separating a light fraction of the fuel from a heavy fraction of the fuel. The fuel is first exposed to the desulfurization reactor and then, if present, to the separator. Finally, the fuel is exposed to the catalyst in the catalytic reactor; and the hydrogen gas generated there from is collected for use in the fuel cell.