Reaction Equilibrium for the Liquid-Phase Simultaneous Decomposition of Methyl tert-Butyl Ether and tert-Butyl Alcohol over Ion-Exchange Resin

Abstract

Using a macroreticular cation exchange resin (Amberlyst 35) as catalyst, reaction equilibrium for the simultaneous splitting of methyl tert-butyl ether and tert-butyl alcohol were conducted in the temperature range of 50–110 °C at 2.0 MPa. When the initial charged methyl tert-butyl ether to tert-butyl alcohol molar ratios were varied and no other reagents were used, the composition effect on activity coefficient calculation was evaluated. As compared with theoretical thermodynamic values, the modified UNIFAC method with proper model parameters is better than the UNIFAC and UNIQUAC methods for calculating the activity-based equilibrium constants of the quinary reaction system. Introducing the best model, the modified UNIFAC method, the determined standard enthalpy and entropy changes for the formation of methyl tert-butyl ether are −36.1 ± 2.6 kJ/mol and −73.8 ± 0.9 J/mol/K, and those for tert-butyl alcohol are −34.2 ± 2.8 kJ/mol and −86.5 ± 1.0 J/mol/K, respectively. These results are comparable to literature data.