(19)

(11)

EP 0 468 043 A1

(12)

(43) Date of publication: 29.01.1992 Bulletin 1992/05 (21) Application number: 91905183.0 (22) Date of filing: 12.02.1991

(51) International Patent Classification (IPC):  C10L 1/ 234( . ) C10L 1/ 22( . ) C10L 10/ 18( . ) C10L 1/ 18( . ) C10L 1/ 14( . ) C10L 10/ 00( . ) C10L 1/ 16( . ) C10L 1/ 24( . ) (86) International application number: PCT/US1991/000934 (87) International publication number: WO 1991/012303 (22.08.1991 Gazette 1991/19)

(84) Designated Contracting States: AT BE CH DE DK ES FR GB GR IT LI LU NL SE (30) Priority: 15.02.1990 US 19900479310 (71) Applicant: CHEVRON RESEARCH AND TECHNOLOGY COMPANY San Francisco CA 94120-7141 (US)	(72) Inventors: BUCKLEY, Thomas, F., III Hercules, CA 94547 (US) KOHLER, David, A. Oakland, CA 94602 (US) OLSEN, Ralph, E. San Rafael, CA 94901 (US) (74) Representative: Nash, David Allan  Haseltine Lake & Co. Hazlitt House 28 Southampton Buildings Chancery Lane London WC2A 1AT London WC2A 1AT (GB)