Abstract: Methyl tert-butyl ether of high purity is prepared by reacting methanol with isobutylene in the presence of an acid ion exchange resin in two stages by feeding methanol and isobutylene mixed with other hydrocarbons to the respective members of a pair of interconnected reactors so that the quantity of alcohol present in one of the reactors is in excess of the stoichiometric equivalent of the quantity of isobutylene therein, while the quantity of isobutylene present in the other reactor is in excess of the stoichiometric equivalent of the quantity of methanol therein, and the methyl tert-butyl ether so formed is recovered through distillation.

Abstract: Methyl tert-butyl ether is prepared, and a stream of hydrocarbons containing isobutylene is freed therefrom, by reacting the isobutylene with methanol in a two stage process wherein, in the first stage, a stream of hydrocarbons containing isobutylene and methanol is fed to a primary reaction zone where the isobutylene and methanol partially react in the temperature range of from 50.degree. to 90.degree.C and at a pressure of from 10 to 30 atmospheres in the presence of a catalyst to form methyl tert-butyl ether which is separated by distillation from the residue of isobutylene and methanol and all other hydrocarbons in the feed stream, and, in a second stage, the residue of isobutylene and methanol and other hydrocarbons is fed to a secondary reaction zone where the residue of isobutylene and methanol react in the vapor phase, at a temperature in the range of 60.degree. to 100.degree.