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

A hydrogen-generation assembly, comprising:

• a fuel processing system having a hydrogen-producing region adapted to receive a feed stream and to produce a mixed gas stream containing hydrogen gas and other gases therefrom, wherein hydrogen gas forms a majority component of the mixed gas stream;
• a heating assembly adapted to receive and combust one or more streams having a combined combustion fuel value at least as great as a corresponding, predetermined threshold value and thereby produce a heated exhaust stream sufficient to heat and maintain at least the hydrogen-producing region within a predetermined temperature range for producing the mixed gas stream;
• a pressure swing adsorption (PSA) assembly adapted to separate at least a portion of the mixed gas stream into a product stream and a byproduct stream, wherein the product stream contains at least substantially pure hydrogen gas and has a reduced concentration of the other gases than the mixed gas stream, wherein the byproduct stream contains at least a substantial portion of the other gases, and further wherein the PSA assembly is adapted to intermittently discharge the byproduct stream;
• and
• a combustion stream supply system adapted to selectively supply the byproduct stream to the heating assembly and to also selectively supply, when a byproduct stream having at least a predetermined threshold fuel value is not discharged from the PSA assembly, an auxiliary fuel stream to the heating assembly, such that the one or more streams supplied to the heating assembly have a combined combustion fuel value at least as great as the corresponding, predetermined threshold value, the combustion stream supply system including:
• an accumulator adapted to receive and at least temporarily store, as stored byproduct gas, the byproduct gas of the byproduct stream intermittently discharged by the pressure swing adsorption assembly;
• a controlled release system adapted to continuously release stored byproduct gas from the accumulator at a first flow rate and selectively release stored byproduct gas from the accumulator at a second flow rate;
• and
• a delivery assembly adapted to receive from the controlled release system the byproduct gas released from the accumulator and to supply the received gas as a combustion fuel stream to the heating assembly.

A method for maintaining a continuous supply of fuel to a heating assembly of a fuel processing system, the method comprising:

• receiving a mixed gas stream containing hydrogen gas and other gases, wherein the hydrogen gas forms a majority component of the mixed gas stream;
• separating the mixed gas stream during a PSA cycle of a pressure swing adsorption (PSA) assembly into a product stream and a byproduct stream, wherein the product stream contains a greater concentration of hydrogen gas than the mixed gas stream and has a reduced concentration of the other gases than the mixed gas stream, and further wherein the byproduct stream contains byproduct gas containing at least a substantial portion of the other gases;
• intermittently discharging the byproduct stream from the PSA assembly during the PSA cycle;
• receiving the byproduct stream in an accumulator adapted to receive and at least temporarily store, within a predetermined pressure range, the byproduct gas of the byproduct stream as stored byproduct gas;
• continuously releasing stored byproduct gas from the accumulator at a first flow rate;
• selectively releasing stored byproduct gas from the accumulator at a second flow rate;
• and
• supplying the released stored byproduct gas as a combustion fuel stream to the heating assembly.