EQUILIBRIUM-CONSTANTS FOR ETHYL TERT-BUTYL ETHER LIQUID-PHASE SYNTHESIS

Thermodynamic equilibrium constants for the liquid-phase synthesis of ethyl tert-butyl ether (ETBE) were determined experimentally in the te mperature range 40-80-degrees-C (313-353 K) at 1.6 MPa for an initial molar ratio of ethanol to isobutene ranging from 1 to 1.5. To reach et herification equilibrium a macroporous sulphonic acid resin (K-2631, B ayer) was used as a catalyst. The thermodynamic equilibrium constant a nd the enthalpy, free energy, and entropy changes are given as a tempe rature function. At 298 K, DELTAH-degrees = -34.8 kJ mol-1. DELTAG-deg rees = -11.7 kJ mol-1, and DELTAS-degrees = -77.3 J mol-1 K-1. A compa rison with the values obtained for MTBE is also included.