Ein Membranverfahren und Destillation kombinierendes Verfahren zur Reinigung von Ethyl-Tert-Butylether

摘要

A new process for the sepn. of a mixt. of ETBE and EtOH, in addn. contg. C4 hydrocarbons which comprises the following steps:- a) Introduction of the mixt. to be sepd. into a distn. zone (de-butanisation) practically all the C4 hydrocarbons being recovered at the head and purified ETBE obtd. at the base. b) At least one phase is withdrawn laterally from the distn. zone which is directed to a permeation zone producing a retentate (re-cycled to the distn. zone) and a permeate comprising mainly EtOH. The permeation zone is fitted with a sepn. membrane comprising at least one selective layer composed of a thick polymer film derived from at least one monomer of dimethyl-aminoethyl methacrylate (DMAEMA). Also claimed is a process for the synthesis of ETBE, including the purification process as above, where the alcohol permeate is re-cycled to the reaction zone or, possible, to a catalytic or reactive distn. column when employed.