Dialkylimidazolium ionic liquids (ILs) [bmim]PF6,[bmim]BF4,and alkylpyridine IL [bupy]BF4 were obtained by super critical fluid (SCF) CO2 extraction.The solubilities of naphthalene,phenanthrene,diphenyl,DBT and diphenyldisulfide in [bmim]PF6,[bmim]BF4 and [bupy]BF4,akylbenzene in [bmim]PF6 and [bmim]PF6 in akylbenzene were determined by high performance liquid chromatography (HPLC).Solubility experimental data of solid liquid equilibrium (SLE) were correlated by means of NRTL equation.The results indicate that NRTL is appropriate for the behaviour of these SLE and the average deviation is 3.86%—9.94%.
The alkylation of benzene with propylene catalyzed by ionic liquids to obtain cumene was investigated. Propylene conversion and cumene selectivity under mild reaction conditions were improved greatly after the ionic liquid was modified with HCl. Under the conditions of 20 oC, 0.1MPa, 5 min of reaction time, and a molar ratio of benzene to propylene of 10:1, propylene conversion increased from 83.6% to 100%, and cumene selectivity increased from 90.86% to 98.47%. In addition, it was found that the reaction could be carried out in two different stages so as to obtain a better result. At the first stage, the key reaction was alkylation and a higher propylene conversion was obtained at a lower temperature;At the second stage, the key reaction was transalkylation and a higher temperature was used to improve cumene selectivity. The reaction temperature, pressure and the amount of catalyst used in this work were lower than those used in traditional alkylation processes.
