US 8,070,841 B2Granted

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

AssigneeIdaTech, LLC

InventorsPatton M. Adams, Travis A. Bizjak, James A. Givens

Life of this patent

Estimating the term…

Loading patent…

Abstract

Combustion fuel stream supply systems for use with pressure swing adsorption (PSA) assemblies, and hydrogen-generation assemblies and/or fuel cell systems containing the same. The PSA assemblies are operated according to a PSA cycle to receive a mixed gas stream and, while producing a product hydrogen stream therefrom, intermittently discharge a byproduct stream. The byproduct stream, when available, may be delivered as a fuel stream to a heating assembly, which may heat the hydrogen-producing region that produces the mixed gas stream. A combustion fuel stream supply system selectively supplies an auxiliary fuel stream when a byproduct stream is not discharged or otherwise does not have a predetermined combustion fuel value sufficient, when combusted, to maintain the hydrogen-producing region within a desired temperature range. The one or more streams supplied to the heating assembly have a combined combustion fuel value at least as great as the predetermined threshold value.

Claims24

Dependent claims

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:

supplying a feed stream to a heated hydrogen-producing region of a fuel processing system;
producing a mixed gas stream containing hydrogen gas, as a majority component, and other gases, in the heated hydrogen-producing region of the 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, wherein the separating includes 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, wherein the cycling is performed as part of the separating;
selectively supplying the byproduct stream to the heating assembly as a fuel stream;
selectively supplying an auxiliary fuel stream to the heating assembly during the at least one reduced byproduct period;
combusting the one or more fuel 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.

6 more elements

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:

supplying a mixed gas stream to a heated hydrogen-producing region of a fuel processing system;
producing a mixed gas stream containing hydrogen gas, as a majority component, and other gases, in the heated hydrogen-producing region of the 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, wherein the separating includes 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, wherein the intermittently discharging is performed as part of the separating;
supplying an auxiliary fuel stream to the heating assembly when the 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.

8 more elements

Dependencies are inferred from the claim text.

Facts

Application: 12/001,838Filed 12 Dec 2007
Published: US 2009/0151249 A118 Jun 2009
Granted: 6 Dec 2011
Term ends: Not estimatedThe source records don’t support an estimate.

Classification38 codes

B01D 53/047
With stationary adsorbents: pressure swing adsorption
C01B 3/384
Using catalysts: with external heating of the catalyst
C01B 3/56
Separation of hydrogen or hydrogen-containing gases from gaseous mixtures, e.g. purification: by contacting with solids; Regeneration of used solids
C01B 7/20
Fluorine; Hydrogen fluoride: fluorine