Kinetic Models of Ethylene Oxide Production on Ag Catalysts: A Review

Process modeling and design of the ethylene oxide production plant is mainly depended on the kinetics of the ethylene oxide production reactions. In this article, the kinetics equations for partial oxidation (epoxidation) of ethylene on silver catalyst were reviewed. There are three competitive reactions in this system: ethylene partial and total oxidation and ethylene oxide total oxidation. The reaction rate equations for these three reactions were compared and advantage and the disadvantage of kinetic models were discussed. Dichloroethane (DCE) is used in these reactions to increase the ethylene oxide selectivity. Therefore, the kinetics of the reactions considering the role of DCE is also reported. Most of the kinetics models have some weaknesses. However, one of the reviewed models was the complete model because of including all three reactions of partial and total oxidation of ethylene and total oxidation of ethylene oxide. Also, this model considered the concentration of selectivity promoter (DCE) and reverse reactions.