Influence of ring-opening reactions on the kinetics of cottonseed oil epoxidation

Production of epoxidized vegetable oils becomes more and more important because they are renewable, nontoxic, and biodegradable chemicals. At the industrial scale, the Prileschajew oxidation is used to produce epoxidized vegetable oils from the corresponding vegetable oils. This oxidation uses an oxygen carrier, which is a percarboxylic acid produced in situ in the aqueous phase, to epoxidize the unsaturated groups on the vegetable oils. One of the main drawbacks of this method is the presence of side reactions: ring-opening reactions of the epoxide group. To minimize the ring-opening reactions and to find the most suitable reactor configuration, it is essential to investigate deeply the different ring-opening reactions. For this work, epoxidation of cottonseed oil by peracetic acid in a batch reactor was studied. By developing a suitable modeling strategy, the kinetic constants for the ring-opening reactions by water, hydrogen peroxide and acetic and peracetic acids were estimated. It was found that ring opening by acetic and peracetic acids was faster than by water and hydrogen peroxide. Based on this model, it was found that a semibatch reactor where hydrogen peroxide and sulfuric acid were added is the most suitable configuration.