Patent ID: 7439413
Filing Date: 2008-10-21
Classification: C07C,Y02P

Abstract:
1. A process for preparing isobutene by acid-catalyzed dissociation of methyl tert-butyl ether (MTBE), said process comprising: fractionating a feed mixture comprising MTBE, C a) a fraction a), comprising MTBE, MSBE, TBA and C4 oligomers. and b) a fraction b), comprising C4- and C5-hydrocarbons, MTBE and methanol, dissociating by an acid-catalyzed reaction the MTBE present in the fraction a) to form a dissociation product comprising methanol and isobutene, and separating the dissociation product to form a separation product c) which comprises unreacted MTBE, methanol, isobutene and low boilers and high boilers in a column into an isobutene-containing top product and a bottom product comprising the unreacted MTBE and the major part of the methanol from the dissociation, and recirculating the bottom product to the feed mixture.