Process for the preparation and fractionation of a mixture of dimethyl ether and chloromethane with water as extractant

US5843286A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Peter Roth · Eppstein, DE
• Erhard Leistner · Solms, DE
• Hans Haverkamp · Oerlinghausen, DE

Key dates

• Filing date: Jun 23, 1997
• Grant date: Dec 1, 1998
• Expiry date: Jun 23, 2017

Classification

• Technology area (CPC Y): Emerging Cross-Sectional Technologies
• CPC primary: Y10S203/24
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

A process for the preparation and fractionation of a mixture of dimethyl ether and chloromethane by extractive distillation with water as extractant. The mixture is prepared by reacting methanol with hydrogen chloride. It is then subjected to an extractive distillation with water as extractant, resulting in chloromethane as top product. In the next step, the dimethyl ether is removed by distillation and, in another step, the extraction water is separated from the methanol which is still present.