Intensification of isobutane/1-butene alkylation process in a micromixing microreactor catalyzed by ILs/H 2 SO 4

The products of isobutane/butene alkylation are ideal high-octane blending components of gasoline pool. Binary mixtures of acidic imidazolium ionic liquids [C n MIm][OTf] ( n  = 4, 6, 8) and H 2 SO 4 were used to catalyze isobutane/butane alkylation in a microreactor integrated with staggered herringbone grooves. The mixing behaviors of acid and hydrocarbons were simulated in the microchannel configured with micromixing elements by computational fluid dynamics (CFD) simulation. [C n MIm][OTf]/H 2 SO 4 showed better catalytic performance than H 2 SO 4 solely. Especially the [OMIm][OTf]/H 2 SO 4 showed excellent performance. In the designed microreactor, the alkylate with research octane number (RON) of 99.5 was obtained at 10.0°C and reaction time of 81 s with [OMIm][OTf]/H 2 SO 4 as catalyst. The results are better than currently available research works implemented in batch reactors. The catalyst [OMIm][OTf]/H 2 SO 4 was recycled 14 times without reducing the catalytic activity. It indicates that the composite catalysts possess excellent reutilization performance.