Systems and methods for supplying auxiliary fuel streams during intermittent byproduct discharge from pressure swing adsorption assemblies

A method for supplying one or more fuel streams having at least a combined threshold combustion fuel value to a heating assembly adapted to receive and combust such a combustion stream, and for producing a heated exhaust stream therefrom, the method comprising:

• producing a mixed gas stream containing hydrogen gas, as a majority component, and other gases, in a heated hydrogen-producing region of a fuel processing system;
• delivering at least a portion of the mixed gas stream to a pressure swing adsorption assembly containing at least an adsorbent bed;
• separating the mixed gas stream delivered to the pressure swing adsorption assembly into streams forming a product stream containing a greater concentration of hydrogen gas than the mixed gas stream and a byproduct stream containing a substantial portion of the other gases;
• cycling through at least one reduced byproduct period during which the combustion fuel value of the byproduct stream from the pressure swing adsorption assembly is lower than a corresponding, predetermined threshold value;
• selectively supplying the byproduct stream to the heating assembly;
• selectively supplying an auxiliary fuel stream to the heating assembly during the at least one reduced byproduct period;
• combusting the one or more streams supplied to the heating assembly;
• and
• heating at least the hydrogen-producing region with the heated exhaust stream to maintain the hydrogen-producing region within a predetermined hydrogen-producing temperature range.

A method for intermittently supplying an auxiliary fuel stream having at least a threshold combustion fuel value to a heating assembly adapted to receive such a fuel stream to produce a heated exhaust stream therefrom, the method comprising:

• producing a mixed gas stream containing hydrogen gas, as a majority component, and other gases, in a heated hydrogen-producing region of a fuel processing system;
• delivering at least a portion of the mixed gas stream to a pressure swing adsorption assembly;
• separating the mixed gas stream delivered to the pressure swing adsorption assembly into a product stream containing a greater concentration of hydrogen gas than the mixed gas stream and a byproduct stream containing a substantial portion of the other gases;
• intermittently discharging from the pressure swing adsorption assembly the byproduct stream and delivering at least a portion of the byproduct stream discharged from the pressure swing adsorption assembly to the heating assembly;
• supplying an auxiliary fuel stream to the heating assembly when a byproduct stream is not discharged, by one or more of:
• redirecting to the heating assembly a portion of the mixed gas stream that is not delivered to the pressure swing adsorption assembly;
• and
• selectively storing at least a portion of the byproduct stream discharged from the pressure swing adsorption assembly and directing to the heating assembly a portion of the stored byproduct stream;
• generating the heated exhaust stream by combusting at least portions of any of the byproduct stream and the auxiliary fuel stream delivered to the heating assembly;
• and
• heating at least the hydrogen-producing region with the heated exhaust stream to maintain the hydrogen-producing region within a predetermined hydrogen-producing temperature range.