Method and device for obtaining isobutenes from conjugated hydrocarbons

US6362386B1 · kind B1 · utility

Assignee

• BASF SE

Inventors

• Bernd Bessling · Grünstadt, DE
• Jean Werner Knab · Schifferstadt, DE
• Wolfgang Brox · Heidelberg, DE
• Bernd Lohe · Heidelberg, DE

Key dates

• Filing date: Dec 28, 1999
• Grant date: Mar 26, 2002
• Expiry date: Dec 28, 2019

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y02P20/10
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for isolating isobutene from a hydrocarbon mixture bya) combining the C4-hydrocarbon mixture with a primary C3- or C4-alkanol;b) reacting the isobutene in the C4-hydrocarbon mixture with the primary C3- or C4-alkanol in the presence of a heterogeneous catalyst to give the corresponding tertiary ether of isobutene,c) separating the resultant reaction mixture into the relatively low-boiling, unetherified C4-hydrocarbons and the relatively higher-boiling tertiary ether of isobutene with the aid of a distillation column, where the C4-hydrocarbons are taken off at the top, and the tertiary ether of isobutene obtained at the bottom is transferred into a reactor,d) cleaving this ether into isobutene and the corresponding primary C3- or C4-alkanol,e) distilling this mixture from d) in a further distillation column, and taking off the isobutene as the top product,which comprises carrying out step a) in a zone (4C) containing reactive internals and containing the catalyst for carrying out step b) arranged in such a way that the zone (4C) is integrated into a distillation column (4), that a reactive distillation takes place in this zone (4C), and that the C3- or C4-alkanol is fed to…