Method for obtaining pure 1,3-butadiene

US11034631B2 · kind B2 · utility

Assignee

• BASF SE

Inventors

• Bernd Heida · Haßloch, DE
• Tobias Keller · Dittelsheim-Heßloch, DE
• Jan-Oliver Weidert · Schifferstadt, DE

Key dates

• Filing date: Jan 24, 2018
• Grant date: Jun 15, 2021
• Expiry date: Jul 2, 2038

Classification

• Technology area (CPC B): Performing Operations; Transporting
• CPC primary: B01D2011/002
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

Process for isolating pure 1,3-butadiene from a crude C4 fraction by extractive distillation using a selective solvent, wherein (a) the crude C4 fraction is introduced into a predistillation column, a first low boiler fraction comprising C3-hydrocarbons is taken off as overhead stream, a gaseous C4 fraction is taken off as side stream and a first high boiler fraction is taken off as bottom stream, (b) the gaseous C4 fraction is brought into contact with a selective solvent in at least one extraction column, giving an overhead fraction comprising butanes and butenes and a bottom fraction comprising 1,3-butadiene and selective solvent, (c) crude 1,3-butadiene is desorbed from the bottom fraction in at least one stripping column, with a stripped selective solvent being obtained and the stripped selective solvent being recirculated to the extraction column, and (d) at least part of the crude 1-3-butadiene is fed to a pure distillation column and a second high boiler fraction is separated off and a gaseous purge stream is taken off. Gaseous purge streams from the columns which are necessary in order to keep the concentration of molecular oxygen below a predetermined concentration limit …