Abstract: Contaminants such as mercaptans, oxygenates and olefins are removed from paraffin-rich feed streams through the use of catalytic distillation performed using an acid catalyst such as a sulphonated resin in the substantial absence of hydrogen. The mercaptans are reacted with the olefins to form less volatile thioethers removed as part of a net bottoms stream with the treated paraffins being removed as the overhead stream.

Abstract: The present invention is a cyclic process for the preparation of ethyl tert.-alkyl ethers by the reaction of an alcohol, ethanol, with an iso-olefin such as isobutylene or isoamylene wherein an effluent from the reaction zone is separated in a distillation column to provide an overhead effluent stream and a bottoms effluent stream comprising ethyl tert.-alkyl ether and unreacted ethanol. The unreacted ethanol is recovered in an adsorption zone comprising a selective adsorbent selected from the group consisting of zeolite 13X, sodium zeolite Y, alumina, silicalite and mixtures thereof. The invention is useful in recovering unreacted ethanol from the bottoms effluent stream and returning the unreacted ethanol to the reaction zone. The invention reduces the cost of this separation which is complicated by the formation of an azeotrope between the unreacted alcohol and the ether.