'A process for making methyl-butyl ether velvet pure by separation of reaction mixtures containing it'.

摘要

Methyl tert-butyl ether (MTBE) is prepared by the selective reaction of methanol with isobutylene contained in a hydrocarbon fraction with four carbon atoms (C4fraction, or C4hydrocarbons), operating in the liquid phase under the influence of acid catalysts. The reaction mixture containing MTBE together with methanol and C4hydrocarbons is distilled, preferably at increased pressure, with separation of the methanol and the C4 hydrocarbons at the head and of MTBE at the bottom of the distillation column. This operation is carried out with an additional lateral liquid flow of a C4 hydrocarbon, or mixture of C4 hydrocarbons, to the column so as to maintain a methanol-C4 hydrocarbon composition in the column at all times with a greater than azeotropic C4 hydrocarbon content at the operating pressure. According to a preferred embodiment the distilled C4 hydrocarbons, after separation from the methanol, are recycled as the lateral flow to the distillation column. It is thus possible to separate MTBE completely in a single distillation operation with a high purity as the product at the bottom of the column.