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

US5763712A · kind A · utility

Assignee

• Hoechst GmbH · DE

Inventors

• Peter Roth · Eppstein, DE
• Erhard Leistner · Solms, DE
• Wolfgang Wendel · Kelkheim, DE

Key dates

• Filing date: Jun 23, 1997
• Grant date: Jun 9, 1998
• Expiry date: Jun 23, 2017

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C41/01
• WIPO field: Chemical engineering
• WIPO sector: Chemistry

Abstract

This invention relates to a process for the preparation and fractionation of a mixture of dimethyl ether and chloromethane by extractive distillation with methanol as extractant. The mixture is prepared by reacting methanol with hydrogen chloride. The mixture is then distilled to remove water and is subsequently subjected to an extractive distillation with methanol as extractant, with chloromethane resulting as top product. In another distillation step, the remaining dimethyl ether is separated from the methanol.