Selective synthesis of MIBK via acetone hydrogenation over Cu-Al mixed oxide catalysts

Abstract

This work involves direct synthesis of methyl isobutyl ketone (MIBK) using a multifunctional catalyst via vapor phase hydrogenation of acetone at atmospheric pressure. Cu-Al mixed oxide catalysts were prepared from inexpensive precursors by co-precipitation of Cu and Al hydroxides with varying Cu:Al atomic ratio. The catalysts were characterized with N2 physisorption, FESEM (coupled with EDS), CO2/NH3-TPD, H2-TPR, FTIR and XRD. The evaluation of catalyst activity was performed in a continuous tubular reactor. The catalytic reactions were studied from variation of parameters such as temperature (200–300 °C), 0.5–1.25 H2/CH3COCH3 mole ratio and space-time (13.34–21.45 kg cat h/kmol acetone). The mixed oxide with Cu/Al atomic ratio of 0.25 showed highest selectivity (74%) for MIBK at 250 °C. Kinetics of the reaction was studied by varying space-velocity at different temperatures. Rate equations based on L-H-H-W model were validated with the kinetic data obtained at four temperatures. The activation energy was found to be 81 kJ/mol.