Method for producing 1,6-hexanediol and 6-hydroxycaproic acid or their esters

US6426438B1 · kind B1 · utility

Assignee

• BASF SE

Inventors

• Rolf Fischer · Heidelberg, DE
• Rolf Pinkos · Bad Dürkheim, DE
• Frank Stein · Bad Dürkheim, DE

Key dates

• Filing date: Apr 20, 2000
• Grant date: Jul 30, 2002
• Expiry date: Apr 20, 2020

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P20/582
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for the preparation of 1,6-hexanediol and 6-hydroxycaproic acid or esters thereof by catalytic hydrogenation of adipic acid, adipic acid monoesters or adipic acid diesters or streams of starting material which contain adipic acid or esters thereof as essential constituents, in which the bottom product obtained in the distillation of the hydrogenation product, following removal of the hexanediol and hydroxycaproic acid or esters thereof, and essentially comprises oligomeric esters of 6-hydroxycaproic acid, is recycled to the hydrogenation, and the resulting mixture of starting material and recycle stream is reacted at from 100 to 300°C., at from 10 to 300 bar in the liquid phase and at a molar ratio of carboxyl groups to be hydrogenated to hydrogen in the reactor of from 1:5 to 1:100 on hydrogenation catalysts is described.