onyme Pour L'etude Et, L'exploitation Des Procedes Georges ClaudeMulticomponent or asymmetric gas separation membranesUS5855647 *15 May 19975 Jan 1999American Air Liquide, Inc.Process for recovering SF6 from a gasUS5858065 *16 Jan 199712 Jan 1999American Air LiquideEffluent gases, e.g. from the semiconductor manufacturing process, efficiently separated using membranes from the ?carrier gases? much