KINETICS AND MECHANISM OF ETHYL TERT-BUTYL ETHER LIQUID-PHASE SYNTHESIS

This paper presents the results of an experimental investigation on ethyl tert-butyl ether (ETBE) liquid-phase synthesis from isobutene (IB) and ethanol (EtOH), catalyzed by an acidic macroreticular ion exchange resin, Amberlyst 15 (A15). The experiments were carried out batchwise in a Parr reactor in the range 323-363 K at 2 MPa for different initial EtOH/IB mole ratios and amounts of catalyst. Data collected at equilibrium gave thermodynamic information which was compared with theoretical calculations using the UNIFAC method. The kinetic results were used to develop a reaction mechanism and a kinetic model. The resin's affinity for polar substances and the strong nonideality of the liquid phase lead to a complex expression, which is valid both in the presence of high and low alcohol concentrations. Simulations performed with this kinetic model agree satisfactorily with the experimental results.