公开(公告)号：EP2432757A1

公开(公告)日：2012-03-28

申请号：EP10723049.2

申请日：2010-05-19

Applicant: BASF SE

Inventor： FORSTER, Günter ,  SWAMINATHAN, Vijay Narayanan ,  WINDLIN, Franz Niklaus ,  LEIENDECKER, Thomas ,  SMIDT, Sebastian Peer

IPC: C07C51/44 ,  C07C53/02 ,  C07C53/08

CPC classification number: C07C51/44 ,  C07C51/50 ,  C07C53/08 ,  C07C53/02

Abstract: In a method for purifying carboxylic acids containing halogen compounds, the carboxylic acid is distilled in the presence of a heavy auxiliary base, the halide of which is liquid at the boiling point of the carboxylic acid. The auxiliary base binds the hydrogen halide contained in the carboxylic acid and/or separated from halogen compounds under a thermal effect, thus lowering the vapor pressure of the hydrogen halide such that the hydrogen halide is retained at the bottom of the distillation apparatus and does not spill over into the distillate. The fact that halide of the auxiliary base is liquid prevents the formation of solid deposits in the distillation apparatus. The carboxylic acid optionally also contains at least one light component.