A fuel processing assembly adapted to produce hydrogen gas from a carbon-containing feedstock. The fuel processing assembly includes a fuel processor, such as a steam reformer. The fuel processing assembly further includes a feed assembly adapted to deliver a carbon-containing feedstock, such as a hydrocarbon, to the fuel processor. In some embodiments, the fuel processing system includes a fuel cell stack that includes at least one fuel cell adapted to produce electrical power from hydrogen gas produced by the fuel processor.