Application of Brönsted acid ionic liquids as green catalyst in the synthesis of 2-propanol with reactive distillation

Abstract

Five Brönsted acidic ionic liquids (ILs) were prepared and characterized by FT-IR, 1H NMR and 13C NMR. Their catalytic activities for the synthesis of 2-propanol (IPOH) via transesterification of isopropyl acetate (IPAc) with methanol (MeOH) were investigated. Among all the tested ILs, [Ps-mim]HSO4 performed best and was used as catalyst for further studies. The reaction kinetics were carried out to correlate the parameters in a homogeneous second order kinetic model. It has been found that there is close agreement between the calculated and experimental values. The high-pressure batch reactive distillation experimental apparatus was set up in order to enhance the conversion of IPAc. A high conversion of IPAc of 99.4% was obtained under the optimal reaction conditions. The catalyst [Ps-mim]HSO4 can be recycled easily by a rotary evaporator and reused without any further treatment. The catalyst had been repeatedly used for four times and no obvious changes in the structure of catalyst could be observed.