Method for purifying trimethylolpropane, which is produced by hydrogenation, by means of continuous distillation

US6692616B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Matthias Dernbach · Eppelheim, DE
• Detlef Kratz · Heidelberg, DE
• Achim Stammer · Freinsheim, DE
• Harald Rust · Bochum, DE
• Gerhard Schulz · Ludwigshafen, DE

Key dates

• Filing date: Jun 26, 2002
• Grant date: Feb 17, 2004
• Expiry date: Jun 26, 2022

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C29/80
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process is disclosed for the purification, by distillation, of trimethylolpropane originating from the hydrogenation of 2,2-dimethylolbutanal, said process including the following steps:(a) reaction of n-butyraldehyde with formaldehyde in the presence of catalytic amounts of a tertiary amine, and hydrogenation of the resulting mixture to give a mixture containing trimethylolpropane;(b) separation of water, methanol, trialkylamine and/or trialkylammonium formate by distillation;(c) heating of the residue obtained in (b) under reduced pressure to a temperature at which TMP is volatile and compounds boiling above TMP are cleaved, in order to separate off, by distillation, TMP and compounds more volatile than TMP;(d) distillation of the distillate obtained in (c) in order to separate off the more volatile compounds and recover pure TMP; and(e) optional distillation of the TMP obtained in (d) in order to recover TMP with a low APHA color index.A process is also disclosed in which trialkylammonium formate is distilled under mild conditions from crude mixtures of polyhydric alcohols, predominantly trimethylolpropane.