부산대학교 도서관

Title:A Novel Inorganic Diffusion Membrane for Hydrogen Separations.Principal,Ronald .L.Cook Investigater; Contract # :DE-FG03-00ER83103.Purpose:The purpose of the phase l research was the demonstration of a ceramicbased membrane for hydrogen separations using hydrogen surface diffusin as the primary separation mechanism.The goal was the preparation of a low-cost membrane capable of hydrogen separations at refinery or chemical processing temperatures (400-800C).Experimental Approach: A porous alumina support tube was coated with a low-cost inorganic coating.The dense coating was then transformed to a nanoporous metal-like ceramic by heating the coated tube using a transformative gas stream.Experimental Results ;A low-cost route to coating porous alumina tubes with a gas tight inorganic precursor was developed. Conditions were then identify to effect a simple transformation of the dense inorganic coatings to a porous metal-like ceramic membrane.These membranes were then tested for hydrogen separation via a surface diffusion mechanism.Initial efforts were hampered by the poor quality of the alumina support tubes.However,when improve support materials were prepared and the metal-like ceramic membranes reevaluated,the membranes showed strong evidence of separation by hydrogen surface diffusion.The improved membranes however,still showed evidence of knudsen diffusion,indicating that additional optimization of the processing procedure needs to be carried out.The H2/He separation ratio following activation of the membrane went from 1.26 at 100C to 1.88 at 600C(the knudsen ratio is3.74).A monotonic increase in the separation ratio waserved with increasing temperature.These results suggest that we have successfully prepared a new type of hydrogen surface diffusion membrane that when potimized would have the potential for high temperature hydrogen separations.