Kinetic Study of CaO-Catalyzed Transesterification of Cyclic Carbonates with Methanol

Abstract

Simultaneous catalytic contributions of CaO in the liquid phase (homogeneous) and in the solid phase (heterogeneous) for transesterification are considered in the kinetic analysis, because sparingly soluble CaO has significant catalytic activity. Experimental concentration–time profiles were obtained at different catalyst loadings, propylene carbonate (PC) concentrations, and methanol concentrations in a temperature range of 20–60 °C in a stirred batch reactor for both the homogeneous and heterogeneous reactions. Kinetic models based on power-law rate forms were evaluated and discriminated to fit the experimental data. Reaction orders of 1 for PC, 2 for methanol, and 1 for both DMC and PG fit the experimental data best for the homogeneous reaction, whereas orders of 0.35 for PC, 1.9 for methanol, and 0 for both DMC and PG fit the experimental data best for the heterogeneous reaction. The heterogeneous CaO catalyst (Ea = 56.8 kJ/mol) was found to be more active than the homogeneous CaO catalyst (Ea = 82.4 ...