Hydrogen-permeable metal membrane and hydrogen purification assemblies containing the same
AssigneeIdaTech, LLC
InventorsDavid J. Edlund, William A. Pledger, Todd Studebaker
Life of this patent
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Abstract
A hydrogen-permeable metal membrane with increased hydrogen flux compared to conventional metal membranes is disclosed. Without sacrificing selectivity, the membrane enables a greater throughput of purified hydrogen. A method for preparing the invention includes at least one etching step in which a controlled volume of etchant is used to selectively remove material from the membrane's surface. Methods for repairing holes or other defects in the membrane are also disclosed. The invention also includes a membrane module adapted for use in purifying hydrogen streams, such as those produced by fuel processors.
Claims24
A hydrogen purification assembly, comprising:
- a membrane assembly adapted to receive a mixed gas stream containing hydrogen gas and other components and to separate the mixed gas stream into a product hydrogen stream and a byproduct stream, wherein the membrane assembly includes at least one hydrogen permeable metal membrane through which a portion of the mixed gas stream passes and a portion of the mixed gas stream does not pass, wherein the portion of the mixed gas stream that passes through the membrane forms the product stream and contains hydrogen gas and the portion of the mixed gas stream that does not pass through the membrane forms the byproduct stream and contains at least a substantial portion of the other components, wherein the at least one hydrogen permeable metal membrane includes an etched region having a reduced thickness compared to an unetched membrane region, and further wherein the etched region is formed by an etching process that provides the etched region with an irregular, non-uniform thickness and therefore an increased surface area compared to a uniformly etched or unetched region.
A hydrogen purification assembly, comprising:
- a membrane assembly adapted to receive a mixed gas stream containing hydrogen gas and other components and to separate the mixed gas stream into a product hydrogen stream and a byproduct stream, wherein the membrane assembly includes at least one hydrogen permeable metal membrane through which a portion of the mixed gas stream passes and a portion of the mixed gas stream does not pass, wherein the portion of the mixed gas stream that passes through the membrane forms the product stream and contains hydrogen gas and the portion of the mixed gas stream that does not pass through the membrane forms the byproduct stream and contains at least a substantial portion of the other components, wherein the at least one hydrogen permeable metal membrane includes a perimeter region adapted to permit a first hydrogen flux therethrough and a central region adapted to permit a greater hydrogen flux therethrough than the perimeter region, and further wherein the central region is etched to permit a greater hydrogen flux than a theoretically expected hydrogen flux through an unetched membrane region having the same composition and thickness as the central etched membrane region.
Dependencies are inferred from the claim text.