ISOBUTYLENE-ASSISTED AQUEOUS EXTRACTION OF METHANOL FROM METHYL TERTIARY BUTYL ETHER

ISOBUTYLENE-ASSISTED AQUEOUS EXTRACTION OF METHANOL FROM METHYL TERTIARY BUTYL ETHER (Docket No. 81,148-F) An impure methyl tertiary butyl ether product contaminated with isobutylene, methanol and water is purified by continuous counter-current contact with water and an isobutylene fraction in an extraction zone comprising a countercurrent contact tower to provide an overhead raffinate comprising isobutylene, methyl tertiary butyl ether and a minor amount of water and an extract comprising methanol, water and a minor amount of methyl tertiary butyl ether; the overhead raffinate being separated in a methyl tertiary butyl ether purification distillation zone into a lighter distillation fraction comprising isobutylene and water and a heavier distillation fraction consisting essentially of methyl tertiary butyl ether; the lighter distillation fraction being decanted to remove water and to provide a distillate isobutylene fraction that is returned to the contact tower as the isobutylene fraction.