Processes for purifying diaryl carbonates

US8022240B2 · kind B2 · utility

Assignee

• Bayer MaterialScience AG · DE

Inventors

• Pieter Ooms · Krefeld, DE
• Johann Rechner · Krefeld, DE
• Matthias Böhm · Leverkusen, DE
• Andre Düx · Bogen, DE
• Kaspar Hallenberger · Leverkusen, DE
• Georg Ronge · Mülheim an der Ruhr, DE
• Johan Vanden Eynde · Zwijnaarde, BE

Key dates

• Filing date: Nov 20, 2008
• Grant date: Sep 20, 2011
• Expiry date: May 16, 2029

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P20/50
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

Processes comprising: transesterifying a dialkyl carbonate and an aromatic hydroxyl compound in the presence of a transesterification catalyst to provide a diaryl carbonate product comprising the transesterification catalyst as an impurity; subjecting the diaryl carbonate product to distillation in a first distillation column having an upper part and a lower part, wherein the upper part comprises a rectifying section and the lower part comprises a stripping section; and withdrawing a first sidestream from the first distillation column, wherein the first sidestream comprises a purified diaryl carbonate.