Continuous distillation of thermolabile monomers

US5951828A · kind A · utility

Assignee

• BASF SE

Inventors

• Manfred Winter · Dittelsheim-Heßloch, DE
• Jacques Dupuis · Ludwigshafen, DE
• Michael Kroner · Oerlinghausen, DE

Key dates

• Filing date: Mar 14, 1997
• Grant date: Sep 14, 1999
• Expiry date: Mar 14, 2017

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S203/20
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

In a process for the continuous distillation of thermolabile monomers under reduced pressure in the presence of formamide in a column, PA1 the thermolabile monomers are continuously fed in liquid form, separately from formamide, into the lower part of the column up to the middle of the column, PA1 Formamide is vaporized with a vaporizer at the bottom of the column and, together with constituents having higher boiling points than the thermolabile monomers, is discharged from the bottom of the column and replaced by addition of fresh formamide, PA1 the thermolabile monomers are taken off at a side offtake in the upper third of the column, with the distillation being controlled such that the monomers contain less than 5% by weight of formamide, and PA1 a product stream containing constituents which have a lower boiling point than the thermolabile monomers is taken off at the top of the column.