公开(公告)号：PT1401846E

公开(公告)日：2005-04-29

申请号：PT02754734

申请日：2002-06-21

Applicant: BASF AG

Inventor： VOSS HARTWIG ,  ORSTEN STEFAN ,  WULFF CHRISTIAN ,  HUGUES VANDENMERSCH

IPC: C07F9/38 ,  B01D61/02

Abstract: The present invention relates to a process for the recovery of N-phosphonomethylglycine from an aqueous mixture which contains N-phosphonomethylglycine, ammonium halides, and alkali metal or alkaline earth metal halides and optionally organic impurities in dissolved form, where (a) the pH of the mixture is adjusted to a value in the range from 2 to 8, (b) a separation of the mixture on a selective nanofiltration membrane is performed, a retentate which is richer in N-phosphonomethylglycine and poorer in halides and a permeate which is richer in halides and poorer in N-phosphonomethylglycine being obtained, and (c) the N-phosphonomethylglycine is recovered from the retentate. The process according to the invention makes possible the recovery of the N-phosphonomethylglycine with simultaneous separation of the halide salts.