Patent ID: 7601302
Filing Date: 2009-10-13
Classification: B01J,C01B,H01M,Y02E

Abstract:
1. A method for delivering feedstock to a hydrogen-producing fuel cell system that includes at least a hydrogen-producing region adapted to produce a stream containing hydrogen gas from at least one feedstock, and a fuel cell stack adapted to produce a power output from an oxidant and hydrogen gas produced in the hydrogen-producing region, the method comprising: drawing a liquid stream from a supply containing at least one carbon-containing feedstock for the hydrogen-producing region of a hydrogen-producing fuel cell system; pumping at a constant flow rate regardless of changes in demand for hydrogen production by the hydrogen-producing region when the hydrogen-producing region is in a hydrogen-producing operating state, a flow of the liquid stream through an outlet conduit that is in fluid communication with a delivery conduit and a first portion of a recycle conduit, wherein the delivery conduit is in fluid communication with the hydrogen-producing region of the hydrogen-producing fuel cell system, wherein the recycle conduit is adapted to provide a flow path to return at least a portion of the liquid stream to at least one of the supply and a location upstream from a delivery mechanism that is adapted to propel the liquid stream to the outlet conduit, and further wherein the pumping step produces a flow rate of the liquid stream that exceeds a threshold flow rate through the hydrogen-producing region, with an excess portion of the flow flowing into the recycle conduit; regulating the distribution of the flow between the delivery conduit and the recycle conduit, wherein the regulating includes creating backpressure in the recycle conduit with a flow restrictor that separates the recycle conduit into at least a first portion that extends between the outlet conduit and the flow restrictor and a second portion that extends from the flow restrictor, wherein the regulating further includes selectively permitting the excess portion of the flow to bypass the flow restrictor by flowing through a bypass conduit in fluid communication with portions of the recycle conduit upstream and downstream of the flow restrictor; receiving at least a portion of the flow from the delivery conduit in the hydrogen-producing region and producing a stream containing hydrogen gas therefrom; and producing an electrical power output from an oxidant and at least a portion of the stream containing hydrogen gas.