Patent ID: 8748671

Claim:
A method of producing ethers from iso-olefins and ethanol, consisting of the following stages: a) mixing a hydrocarbon fraction containing iso-olefins with at least one alcohol stream that contains ethanol, b) etherification reaction by reaction of the mixture obtained in stage a) in the presence of an ion-exchange resin so as to obtain an ether-hydrocarbon-alcohol effluent, c) separation, in a fractionating column, of said ether-hydrocarbon-alcohol effluent into a first ether-enriched effluent containing part of the excess alcohol and into a second hydrocarbon-enriched effluent containing the other part of the excess alcohol, and treating the second hydrocarbon-enriched effluent obtained in stage c) by carrying out the following stages: d) contacting said effluent with a non-aqueous ionic liquid so that the ionic liquid becomes laden with alcohol and the effluent becomes depleted in alcohol, the ionic liquid having the formula Q + A − , Q + designating an ammonium, phosphonium and/or sulfonium cation, and A − designating an anion likely to form a liquid salt with said cation, e) regenerating the alcohol-laden ionic liquid by separating said ionic liquid and the alcohol, said separation consisting in evaporating the alcohol, and then condensing it, and wherein said separated and condensed alcohol is recycled in the process to stage a).