Patent ID: 7473808
Filing Date: 2009-01-06
Classification: B01D,C07C

Abstract:
1. A process for the preparation of ethyl tert-butyl ether (ETBE) comprising: reacting a low-water ethanol with an isobutenic hydrocarbon mixture; wherein the low-water ethanol is prepared by a process comprising: introducing ethanol streams with different water contents separately into different membrane units in which the ethanol streams are each separated into relatively low-water ethanol as the retentate and relatively water-rich permeate, and combining the retentate stream from at least one membrane unit for separating an ethanol stream with a relatively high water content with the feed stream and/or the retentate stream of at least one other membrane unit for separating an ethanol stream, wherein only streams that have a difference in ethanol concentration of not more than 1% by mass absolute are combined.