Process for separating solutions containing propylene oxide

US4070253A · kind A · utility

Assignees

• BAYER HEALTHCARE LLC · DE
• Deutsche Gold- und Silber-Scheideanstalt Vormals Roessler

Inventors

• Willi Hofen · Rodenbach, DE
• Rolf Wirthwein · Hanau, DE
• Karl-Hermann Reissinger
• Jorg Krekel

Key dates

• Filing date: Apr 28, 1976
• Grant date: Jan 24, 1978
• Expiry date: Apr 28, 1996

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07D301/32
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

Process for separating a solution, which essentially contains propylene oxide, propylene, a carboxylic acid containing 1 to 4 carbon atoms and benzene, by distillation. The solution is fed to a first distillation stage in which propylene, propylene oxide and an amount of the benzene contained in the solution such that the top product from this first distillation contains 20 to 70% by weight of benzene are distilled off over the top at a pressure of 1.0 to 2.5 bars, and in which the carboxylic acid and the remaining benzene are obtained as the sump product. The top product from the first distillation is fed to a second distillation column in which propylene and possibly present small fractions of components which boil lower than propylene oxide are distilled off over the top and a sump product which essentially consists of propylene oxide and benzene is obtained and part of this is returned as reflux to the first distillation column.