NOVELTY - The device (10) has an enclosure (12) defining a pressure vessel with an internal compartment (18). A hydrogen-selective and/or permeable membrane (46) is secured to a perimeter shell to form a seal, and extends within the compartment to divide the compartment into mixed gas and permeate regions (30, 32). The membrane has a mixed gas surface to be contacted by a mixed gas stream, and a permeate surface opposed to the mixed gas surface (48), where a permeate stream is formed from a portion of the mixed gas stream, and a byproduct stream is formed from another portion of the mixed gas stream.    USE - Hydrogen purification device for purifying hydrogen that is utilized in the manufacture of products e.g. metals, edible fats and oils, in semiconductors and microelectronics, and as a fuel source for an energy conversion device e.g. fuel cell, of a fuel processor, where the fuel cell produces an electric current for an energy-consuming device e.g. motor vehicle, recreational vehicle, boat, tools, lights or lighting assemblies, appliances such as a household appliance, and for house, office, business, signaling or communication equipment.    ADVANTAGE - The purification device is designed such that it produces a byproduct stream containing minimum amount of hydrogen gas, thus maximizing the yield of purified hydrogen gas, while purifying the mixed gas stream to remove undesirable impurities from the stream before delivering the stream to the fuel cell. The hydrogen purification device produces the byproduct stream containing sufficient hydrogen gas to provide the required fuel for a burner assembly to maintain the hydrogen purification device at a desired operating temperature.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is also included for a method of forming a hydrogen purification device.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic cross-sectional view of a hydrogen purification device.    Hydrogen purification device (10)    Enclosure (12)    Internal compartment (18)    Mixed gas region (30)    Permeate region (32)    Hydrogen-selective and/or permeable membrane (46)    Mixed gas surface (48)