Formation of Di‐isobutene, main by‐product of methyl tertiary butyl ethyl ether synthesis catalyzed by ion exchange resin

Abstract

AbstractAn experimental set‐up is presented for the measurement of steady‐state reaction rates in the liquid phase methyl tertiary butyl ether (MTBE) synthesis from isobutene and methanol using ion exchange resin as catalyst. This apparatus was used for a separate investigation of the main side reaction, i.e., the formation of isobutene dimers (DIB), in the temperature range between 60 and 90°C. The reaction catalyzed by Amberlyst 15 (A15) showed no steady‐state behaviour, but the catalytic activity declined at a rate dependent on the reaction conditions. Time constants for activity loss were determined in the range from 3.5 to 30 h. The deactivated A15 catalyst could be regenerated through MTBE synthesis experiment. Deactivation is assumed to be caused by blocking of the microparticle gel phase by higher isobutene oligomers. The DIB formation, using 1‐butene as solvent, was of 2nd order with respect to isobutene and showed an apparent activation energy of about 40 kJ/mol.