Process for conjointly preparing methyl tert.-butyl ether and obtaining isobutene

Abstract

A process for conjointly preparing methyl tert.-butyl ether and obtaining isobutene from an isobutene-containing C.sub.4 -hydrocarbon mixture. In the process the C.sub.4 -hydrocarbon mixture is reacted, in one or more etherification stages, with methanol and a primary C.sub.3 - or C.sub.4 -alcohol in the presence of an acid condensing agent, the resulting reaction mixture or mixtures are then separated into a fraction containing the unconverted hydrocarbons, the methyl tert.-butyl ether and a fraction containing the C.sub.3 - or C.sub.4 -alkyl tert.-butyl ether. Thereafter, the C.sub.3 - or C.sub.4 -alkyl tert.-butyl ether is decomposed at an elevated temperature, in the presence of an acid catalyst, into isobutene and primary C.sub.3 - or C.sub.4 -alcohol.

Dependencies are inferred from the claim text.