Isobutane alkylation with 2-butene in novel ionic liquid/solid acid catalysts

Abstract

For upgrading of petroleum, the alkylation reaction between isobutane and 2-butene can produce a premium blending stock for gasoline. The novel ionic liquid/solid acid catalysts that combined the advantages of ionic liquids (IL) and solid acids (SA) were used to catalyze the C4 alkylation. These catalysts were prepared by dispersion of SO42−/ZrO2 (SZ) into the mesopores MCM-41 and by immobilization of IL on solid supports. The materials have been characterized by X-ray diffraction, nitrogen adsorption isotherms, infrared spectroscopy, magic-angle spinning solid state NMR (29Si/31P MAS NMR), and temperature-programmed desorption of NH3. Results showed that SZ was loaded into the inner pores of MCM-41 mesopores, and the IL played an important role in maintaining the activity of the as-synthesized catalyst. The catalytic behavior of the novel IL/SA catalyst has been investigated in a batch reactor and a continuously stirred tank reactor (CSTR) at 25 °C, respectively. It is found that 5 g IL/SZ-Zn@MCM-41 in the CSTR could continuously catalyze the alkylation reaction more than 240 min. The amount of trimethylpentanes (TMP) and the research octane number (RON) of the obtained alkylate reached up to 83.3 wt% and 98.5, respectively.