© WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
April 19, 2013
VIP: Liquid Phase Isobutane/2-Butene Alkylation Using Hydrogen-Chloride-Promoted Lewis Acidic Ionic Liquids
F. Pöhlmann, L. Schilder, W. Korth, A. Jess*
In isobutane/butene alkylation, chloroaluminate ionic liquid catalysts (CAIL) ([BMIM]Cl/AlCl3, xAlCl3=0.64) deactivate fast with time on stream with respect to activity and selectivity. Hence, it is crucial to find promising co-catalysts to stop the deactivation process. So, the effect of anhydrous hydrogen chloride gas (HCl) was studied in a batch reactor. This gaseous co-catalyst leads to an increased reaction rate and improves the yield of trimethylpentanes, the primarily desired high-octane compounds of alkylation. Moreover, already deactivated CAIL catalysts are reactivated by gaseous HCl. As a consequence the deactivation of the CAIL catalyst can be suppressed completely.