Process for the preparation of dialkyl carbonates

US5142087A · kind A · utility

Assignee

• BASF SE

Inventors

• Klaus Joerg · Schifferstadt, DE
• Franz Mueller · Fort Wayne, US
• Wolfgang Harder · Weinheim, DE
• Rudolf Kummer · Bischofswerda, DE

Key dates

• Filing date: Aug 8, 1990
• Grant date: Aug 25, 1992
• Expiry date: Aug 8, 2010

Classification

• Technology area (CPC C): Chemistry; Metallurgy
• CPC primary: C07C68/01
• WIPO field: Organic fine chemistry
• WIPO sector: Chemistry

Abstract

A process for the continuous synthesis of dialkyl carbonates of the general formula I ##STR1## in which R denotes C.sub.1 -C.sub.4 -alkyl, by reaction of C.sub.1 -C.sub.4 -alkanols with carbon monoxide and oxygen at elevated temperature and pressure and in the presence of a copper-containing catalyst dissolved or suspended in the reaction medium, wherein PA1 a) a gas stream containing carbon monoxide and oxygen is bubbled through the alkanol/catalyst mixture present in the reactor at a rate of from 1 to 100 liters per hours per gram of copper present in the reactor, part of which gas stream reacts with the alkanol to form dialkyl carbonate and water, which components are continuously entrained, together with alkanol, as a gaseous mixture, from the reaction mixture by means of the remaining, unreacted portion of the carbon monoxide/oxygen gas stream, whereupon PA1 b) the resulting gaseous mixture is separated, in a separator, into gaseous and liquid phases, the gaseous phase being recycled to the reactor if desired, and PA1 c) the liquid phase, which essentially consists of dialkyl carbonate, water and alkanol, is separated into its components, the dialkyl carbonate being isolated a…