NOVELTY - The hydrogen purification device (10) useful in fuel processing and fuel cell systems, comprises an enclosure having an internal fluid-tight compartment in which a hydrogen-selective membrane (46) is supported and is adapted to receive a mixed gas stream (24) containing hydrogen gas and other gases under a pressure of 50 psi, a membrane envelope formed from a pair of hydrogen-selective membranes, and a fuel processor (300) to produce the mixed gas stream. The pair of the membranes are spaced-apart from each other with their permeate surfaces.    USE - The hydrogen purification device is useful in fuel processing and fuel cell systems, where the purified hydrogen is useful in the manufacture of many products including metals, edible fats and oils, and semiconductors and microelectronics.    ADVANTAGE - The hydrogen purification device is capable of effectively removing the undesirable impurities from a mixed gas stream thus providing pure hydrogen gas, and can able to withstand the stresses encountered when operating at the selected pressure.    DETAILED DESCRIPTION - The hydrogen purification device (10) useful in fuel processing and fuel cell systems, comprises an enclosure having an internal fluid-tight compartment in which a hydrogen-selective membrane (46) is supported and is adapted to receive a mixed gas stream (24) containing hydrogen gas and other gases under a pressure of 50 psi, a membrane envelope formed from a pair of the hydrogen-selective membranes, and a fuel processor (300) to produce the mixed gas stream. The pair of the membranes are spaced-apart from each other with their permeate surfaces generally facing each other to define a harvesting conduit. The hydrogen-selective membrane separates the mixed gas stream into a hydrogen-rich stream (34) formed from a portion of the mixed gas stream that passes through the hydrogen-selective membrane to the harvesting conduit, and into a byproduct stream formed from a portion of the mixed gas stream that does not passes through the hydrogen-selective membrane. The hydrogen-rich stream contains hydrogen having a greater purity than the mixed gas stream. The hydrogen-selective membrane is comprised of a primary component and a secondary component. Each pair of the membranes includes a first surface oriented to be contacted by the mixed gas stream, and a permeate surface that is opposed to the first surface. The membrane envelope includes a support within the harvesting conduit, and is adapted to support the pair of the membranes. The support includes a pair of generally opposed surfaces, which are adapted to provide support to a respective one of the permeate surfaces of the pair of the membranes. The fuel processor includes a reforming catalyst bed, and is adapted to produce the mixed gas stream by a coal gasification process. The device is adapted to operate at 200-400 degrees C. The compartment has an inlet, an outlet and the hydrogen-selective metal membrane. The membrane is formed from a sulfur-tolerant alloy, and is adapted to separate mixed gas streams having 25-75 ppm sulfur into the hydrogen-rich stream and the byproduct stream without deterioration of the membrane. An INDEPENDENT CLAIM is included for a method for removing impurities from a mixed gas stream.    DESCRIPTION OF DRAWING(S) - The diagram shows a schematic diagram of another fuel processor including an integrated hydrogen purification device.    Hydrogen purification device (10)    Mixed gas stream (24)    Hydrogen-rich stream (34)    Hydrogen-selective membrane (46)    Fuel processor. (300)