(19)

(11)

EP 0 920 349 A1

(12)

(43) Date of publication: 09.06.1999 Bulletin 1999/23 (21) Application number: 97929593.0 (22) Date of filing: 08.07.1997

(51) International Patent Classification (IPC):  B01D 17/ 06( . ) (86) International application number: PCT/NL1997/000396 (87) International publication number: WO 1998/002225 (22.01.1998 Gazette 1998/03)

(84) Designated Contracting States: BE DE ES FR GB IT NL (30) Priority: 15.07.1996 NL 19961003591 (71) Applicant: DSM N.V. 6411 TE Heerlen (NL)	(72) Inventors: SIMONS, Antonius, Jacobus, Franciscus NL-6163 HN Geleen (NL) THIJERT, Marcellinus, Plechelmus, Gerhardus Augusta, GA 30909 (US)