Process for the preparation of methyl tertiary butyl ether

Claim 1

In a process for the preparation of methyl tertiary butyl ether by contacting an isobutene-containing hydrocarbon feed, predominantly consisting of hydrocarbons with four carbon atoms, with methanol in a reaction zone in the presence of a catalyst and separating the methyl tertiary butyl ether thus formed from the reaction mixture, the improvement essentially comprising the combination of steps of: carrying out a first reaction between isobutene contained in said hydrocarbon feed and methanol in a first reaction zone in the presence of a catalyst, and separating methyl tertiary butyl ether thus formed from a first residual hydrocarbon stream containing normal-butene; introducing at least a portion of said residual hydrocarbon stream into an isomerization zone wherein at least a portion of the normal-butene introduced therein is converted to form a second residual hydrocarbon stream containing isobutene; and introducing said second residual hydrocarbon stream, together with a further amount of methanol, into a second reaction zone, separate from said first reaction zone, wherein isobutene contained in said second residual hydrocarbon stream is reacted with said further amount of methanol in the presence of a catalyst to form a further amount of methyl tertiary butyl ether.