Kinetic study of ethyl octyl ether formation from ethanol and 1-octanol on Amberlyst 70



An option to introduce bioethanol to diesel, improving at the same time its fuel quality, is by adding ethyl octyl ether (EOE). It can be obtained successfully by the dehydration reaction between ethanol and 1-octanol over acidic ion-exchange resins. In the present work, the kinetic study of EOE synthesis on Amberlyst 70 in the liquid phase is performed in a 20-cm3 fixed-bed reactor and in a 100-cm3 batch reactor at 423–463 K and 2.5 MPa. EOE synthesis takes place together with diethyl ether (DEE) formation as main side reaction. A mechanistic kinetic model in terms of component activities is proposed for EOE synthesis (Ea=105 ± 4 kJ/mol) and for DEE formation (Ea =100 ± 5 kJ/mol). Reaction rates were highly inhibited by the adsorption of the formed water on Amberlyst 70. The inhibitor effect of water is well represented as a competitive adsorption with alcohols reactants on the catalysts surface. © 2014 American Institute of Chemical Engineers AIChE J, 60: 2918–2928, 2014