Identification of Kinetics and Autocatalytic Behavior in Acetic Anhydride Hydrolysis Reaction via Reaction Calorimetry

In the fine and pharmaceutical chemical industries, the operation of highly exothermic reactions with the autocatalytic feature needs great caution. Identification of the autocatalytic behavior for a given reaction is of signification importance. In this work, first, an autocatalytic mathematic model for the acetic anhydride hydrolysis reaction is established. Then, a series of experiments at an approximate mole ratio of acetic anhydride to water with the solvent of acetic acid are designed to study this reaction by reaction calorimetry. Third, the six isothermal experiments are used to fit the kinetic constants, and the fitting result is very good and reasonable when compared to the published literature. Besides, it is proven that this reaction also has an autocatalytic feature at an approximate mole ratio of acetic anhydride to water. Last, the determined kinetic constants are also verified by two experiments operating under isoperibolic conditions.