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EP 0 614 444 A1

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(43) Date of publication: 14.09.1994 Bulletin 1994/37 (21) Application number: 93900639.0 (22) Date of filing: 23.11.1992

(51) International Patent Classification (IPC):  C01B 31/ 02( . ) C25B 1/ 14( . ) H01M 4/ 58( . ) H01M 4/ 587( . ) C25B 1/ 00( . ) C25B 3/ 00( . ) H01M 4/ 583( . ) (86) International application number: PCT/US1992/010120 (87) International publication number: WO 1993/011067 (10.06.1993 Gazette 1993/14)

(84) Designated Contracting States: DE FR GB IT NL (30) Priority: 26.11.1991 US 19910798390 (71) Applicant: EXXON RESEARCH AND ENGINEERING COMPANY Florham Park, New Jersey 07932-0390 (US)

(72) Inventors: GORUN, Sergiu, Mircea Upper Montclair, NJ 07043 (US) GREANEY, Mark, Alan Upper Black Eddy, PA 18972 (US) COX, Donald, Martin Watchung, NJ 07060 (US) CHIANELLI, Russell, Robert Branchburg, NJ 08876 (US) STIEFEL, Edward, Ira Bridgewater, NJ 08807 (US) (74) Representative: Somers, Harold Arnold, et al  ESSO Engineering (Europe) Ltd. Patents & Licences Mailpoint 72 Esso House Ermyn Way Leatherhead, Surrey KT22 8XE Leatherhead, Surrey KT22 8XE (GB)