Patent ID: 7736596

Claim:
A hydrogen-producing fuel processing assembly, comprising: a hydrogen-producing region adapted to receive at least a feed stream containing at least a carbon-containing feedstock and to produce a mixed gas stream containing hydrogen gas as a majority component therefrom; and a feedstock delivery system adapted to deliver the feed stream containing at least a carbon-containing feedstock to the hydrogen-producing region of the fuel processing assembly within a hydrogen-producing pressure range, wherein the feedstock delivery system is in communication with a liquid supply containing at least the carbon-containing feedstock, wherein the feedstock delivery system comprises: a pump assembly adapted to draw from the supply a liquid inlet stream containing at least the carbon-containing feedstock and to emit a liquid outlet stream having a flow rate; an outlet conduit in fluid communication with a delivery conduit and with a recycle conduit, wherein the delivery conduit is in fluid communication with the hydrogen-producing region of the hydrogen-producing fuel processing assembly to deliver a portion of the liquid outlet stream thereto as the feed stream, and the recycle conduit is in fluid communication with at least one of the liquid supply and an inlet conduit through which the inlet stream is drawn to the pump assembly; wherein the outlet conduit is adapted to receive the liquid outlet stream and to define a flow path for the liquid outlet stream to the delivery conduit and the recycle conduit; a flow restrictor adapted to create backpressure in the recycle conduit; and a pressure-actuated valve adapted to selectively permit liquid in the recycle conduit to bypass the flow restrictor; wherein the feedstock delivery system is adapted to deliver the feed stream to the hydrogen-producing region within the hydrogen-producing pressure range without varying the flow rate of the liquid outlet stream in response to changes in a demand for hydrogen production by the hydrogen-producing region when the hydrogen-producing region is in a hydrogen-producing operating state.