The Catalytic Performance Study of Chloroaluminate Ionic Liquids on Long-Chain Alkenes Alkylation

Friedel–Crafts alkylation of long-chain alkenes (mixed C16–24 olefins) with toluene catalyzed by chloroaluminate ionic liquids was investigated systematically in this work. The catalysts were characterized by FT-IR (acetonitrile molecule as probe), specific gravity, and 27Al NMR. Besides, the effect of chloroaluminate ionic liquids catalysts, catalysts dosage, toluene/olefins molar ratio, reaction temperature, reaction time, and C16–24 olefins (long-chain alkenes) on alkylation were investigated thoroughly. Bromine value and high performance liquid chromatography were employed as the evaluation method for alkylation products. The experiment results indicate that excellent conversion (99.85%) and good selectivity (32.99%) of C18 olefins alkylation have been reached under the optimal reaction conditions (T/O molar ratio = 10:1, catalyst/olefins = 0.3:1, 50 °C, 20 min). Moreover, the catalytic recyclability of [HMIM]Cl-2AlCl3 was proved after 10 reuses. The study shows that [HMIM]Cl-2AlCl3 not only has catalytic performance on long-chain alkenes alkylation but also exhibits excellent recyclability, possessing a possibility of industrial continuous production.