NOVELTY - A fuel processor comprises a membrane module including a hydrogen-selective membrane having a feed side and a permeate side (68). The product stream is formed from portion of mixed gas stream that passes through membrane and the byproduct stream is formed from portion of mixed gas stream that does not pass through the membrane. The membrane is composed of alloy comprising palladium and copper, and has an average thickness of at most 25 microns.    USE - The fuel processor is for receiving a portion of the product stream and producing an electric current in a fuel cell system (claimed).    ADVANTAGE - The hydrogen-selective membrane has reduced thickness and removes impurities from a feed stream of hydrogen gas.    DETAILED DESCRIPTION - A fuel processor comprises a hydrogen-producing region adapted to receive a carbon-containing feedstock and water and produce a mixed gas stream containing hydrogen gas and other gases; and a membrane module adapted to receive the mixed gas stream and to separate the mixed gas stream into a byproduct stream containing at least a portion of the other gases and a product stream containing at least hydrogen gas. The membrane module comprises a hydrogen-selective membrane having a feed side and a permeate side. The product stream is formed from a portion of the mixed gas stream that passes through the membrane and the byproduct stream is formed from a portion of the mixed gas stream that does not pass through the membrane. The membrane is composed of an alloy comprising palladium and copper, and has an average thickness of at most 25 microns. It includes at least one region containing a patch material that is formed from a material having a different composition than the alloy. A support is adapted to support the membrane and includes a surface adapted to engage the permeate side of the membrane.    DESCRIPTION OF DRAWING(S) - The figure is an exploded isometric view of a membrane envelope including a screen structure.    Permeate side (68)    Screen structure (70, 72)    Screen members (73)    Adhesive (80)