The kinetics of hydrocarbonylation of methyl acetate to ethylidene diacetate (EDA) using the Rh(CO)Cl(PPh3)(2)/PPh3/MeI catalyst system was studied in a temperature range of 433-463 K. Concentration-time profiles were obtained for different reaction conditions such as concentrations of methyl acetate, methyl iodide, and catalyst and partial pressures of CO and hydrogen. Rate equations were proposed on the basis of a reaction mechanism with [Rh(CO)(2)I-2](-) as the catalytically active species. Activation energies for acetic anhydride (Ac2O) and EDA formation were found to be 80.72 and 91.79 kJ/mol, respectively. A semibatch reactor model was developed, and the effect of the carbon-monoxide-to-hydrogen ratio on the conversion of methyl acetate and selectivity to EDA is discussed.