NOVELTY - Hydrogen-generation assembly includes pressure-driven combustion stream supply system (140) to receive by-product stream (76) from pressure swing adsorption (PSA) assembly (73) and to continuously supply, during the PSA cycle, a combustion fuel stream (92) containing the by-product gas and having a threshold fuel value, to a downstream component of fuel processing system (64), where combustion stream supply system comprises an accumulator and a controlled release system.    USE - The hydrogen-generation assembly is used for fuel cell system. It is used in energy-producing system useful for energy producing and consuming assembly. The assembly is used in the form of steam reformer used to produce a reformate stream containing hydrogen gas and other gases from water and carbon-containing feedstock(s).    ADVANTAGE - The combustion fuel stream supply system ensures that the supply of combustible fuel from the PSA assembly to the heating assembly contains a sufficient fuel value, to maintain the hydrogen-producing region at or within a predetermined hydrogen-producing temperature or range of temperatures.    DETAILED DESCRIPTION - Hydrogen-generation assembly comprises:    (A) fuel processing system (64) having hydrogen-producing region to receive a feed stream and to produce a mixed gas stream containing hydrogen gas and other gases, where hydrogen gas forms a majority component of the mixed gas stream;    (B) PSA assembly (73) to receive and separate, during PSA cycle, a portion(s) of the mixed gas stream into a product hydrogen stream and a by-product stream (76), where product hydrogen stream contains a greater concentration of hydrogen gas than the mixed gas stream and has a reduced concentration of other gases than the mixed gas stream, the by-product stream containing by-product gas contains a portion(s) of the other gases, and the PSA assembly intermittently discharges the by-product stream during the PSA cycle;    (C) pressure-driven combustion stream supply system (140) to receive the by-product stream from the PSA assembly and to continuously supply, during the PSA cycle, a combustion fuel stream (92) containing the by-product gas and having a threshold fuel value, to a downstream component of the fuel processing system, where combustion stream supply system comprises an accumulator to receive and temporarily store, as stored by-product gas, a portion(s) of the by-product stream intermittently discharged by the PSA assembly; and a controlled release system to selectively release the stored by-product gas from the accumulator; and    (D) delivery assembly (142) to receive the stored by-product gas released from the accumulator through the controlled release system and to supply the stored by-product gas as the combustion fuel stream to the downstream component of the hydrogen-generation assembly.    An INDEPENDENT CLAIM is included for maintaining a continuous supply of fuel to a heating assembly of fuel processing system.    DESCRIPTION OF DRAWING(S) - The drawing is a schematic view of hydrogen-producing assembly in the form of steam reformer to produce a reformate stream containing hydrogen gas and other gases from water and at least one carbon-containing feedstock.    Fuel processing system (64)    PSA assembly (73)    By-product stream (76)    Combustion fuel stream (92)    Pressure-driven combustion stream supply system (140)    Delivery assembly (142)