Kinetics of acetone hydrogenation for synthesis of isopropyl alcohol over Cu-Al mixed oxide catalysts

Abstract

Abstract Vapor phase hydrogenation of acetone was carried out over Cu-Al mixed oxide catalysts. The catalysts were synthesized via co-precipitation method with Cu:Al atomic ratio varied from 0.25 to 1. The characterization of the catalysts was done by using XRD, BET, FESEM (coupled with EDS), FTIR, H2-TPR, NH3-TPD and CO2-TPD. The performance of the synthesized catalysts was evaluated in a continuous packed bed reactor by varying parameters such as temperature (150 to 225 °C), H2/acetone mole ratio (0.5 to 1.25) and space-velocity (0.09 to 0.145 kmol acetone/kg cat. h). Along with direct hydrogenation, condensation of acetone also occurred due to the presence of basic and acidic sites in the catalysts. The catalyst having Cu:Al atomic ratio of 0.5 showed highest selectivity (98%) to isopropyl alcohol at 175 °C. Kinetic study was conducted at different temperatures by varying space-velocity. LHHW type model rate equations were fitted with the kinetic data obtained at three different temperatures. The activation energy of the reaction was determined to be 44.3 kJ/mol.