Conversion, selectivity, and kinetics of the addition of isopropanol to isobutene catalyzed by a macroporous ion-exchange resin

Equilibrium conversion, selectivity, and kinetics of the liquid-phase synth esis of isopropyl tert-butyl ether (IPTBE) from 2-propanol and isobutene we re studied experimentally over a commercial ion-exchange resin in the tempe rature range 303-353 K at 1.6 MPa. The isobutene equilibrium conversion har dly changes upon varying the initial molar ratio of 2-propanol to isobutene . The IPTBE yield is very high and is independent of temperature for an ini tial molar ratio for 2-propanol to isobutene greater than 2. The best kinet ic model stems from a mechanism in which 2-propanol, adsorbed on one center , reacts either with isobutene adsorbed on one adjacent center or with isob utene from solution to give the ether adsorbed on one center. The surface r eaction is the rate-limiting step, in which three centers take part. An app arent activation energy of 75.5 kJ.mol(-1) was obtained.