NOVELTY - A polar-substance-permselective membrane (10) comprises a porous support (12); and a hydrophilic or hydrophobic active-membrane material (11), where pores of the porous support are filled or coated with the active-membrane material to render the polar-substance-permselective membrane impermeable to non-polar gases at a pressure gradient of at least 70 kPa across the polar-substance-permselective membrane when the active-membrane material is wet, the active-membrane material is selectively permeable to a polar substance.    USE - For in-situ extraction of water molecules directly from hot exhaust streams which is useful as feedstock in the process of converting liquid hydrocarbons into hydrogen-rich gas stream.    ADVANTAGE - The membrane is compact, versatile, and low-cost, and can operate with little or no parasitic power consumption. The membrane recovers water and heat more effectively and reliably and from various process stream conditions. The membrane is substantially impermeable to non-polar gases at operating pressure ranges and has high density of hydrophilic centers uniformly distributed throughout the membranes.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for extracting (M1) a polar substance from a gas mixture involving providing polar-substance-permselective membrane (M1); flowing a gas mixture across the surface of the polar-substance-permselective membrane in contact with the hydrophilic active-membrane material, a pressure gradient of at least 70 kPa existing across the polar-substance-permselective membrane; allowing a polar substance from the gas mixture to adsorb to the active- membrane material and to be transported across the polar-substance-permselective membrane; and collecting and removing the polar substance from a permeate side of the polar-substance-permselective membrane opposite from the surface across which the gas mixture flows.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic illustration of water-permselective membrane module.    Polar-substance-permselective membrane (10)    Hydrophilic or hydrophobic active-membrane material (11)    Porous support (12)    Stainless-steel tubes (13)    Water-recovery membrane housing (14)