Chemical Engineering and Processing, Vol.130, 88-92, 2018
Process intensification on the selective catalytic oxidation of cumene with ionic liquids
The cumene-phenol process, based on the decomposition of cumene hydroperoxide (CHP) to phenol and acetone, is currently used worldwide for phenol synthesis. Peroxidation of cumene is the key step to synthesis of phenol. Alkali solutions, such as NaOH, were added to the oxidation system traditionally. In this paper, a novel type of catalyst, ionic liquids (ILs), for the cumene oxidation was proposed to intensify the catalytic oxidation of cumene. The reaction rate was much faster in the presence of ILs than that of NaOH. The structure and constitute of the ILs influenced the conversion of ctunene and the selectivity of CHP. For the imidazolium-based ILs, the selectivity of CHP under the catalysis of [C(4)dmim]Br (53.1%) was higher than that of [C(4)mim]Br (36.2%). However, the selectivity in the presence of [C(4)mim]OH (67.1%) was almost as the same as that of [C(4)dmim]OH (63.2%). It was found that the acidic proton of the imidazolium ring catalyzed the decomposition of CHP. This was proved by that the ILs with less acidic protons exhibited better selectivity of CHP. The selectivity of CHP with [MP4]Br as catalyst reached 87.7%.