THE EFFECT OF THE REACTION MEDIUM ON THE KINETICS OF THE LIQUID-PHASEADDITION OF METHANOL TO ISOBUTENE

The liquid-phase addition of methanol (MeOH) to isobutene (IB) to give methyl tert-butyl ether (MTBE) on the ion-exchange resin Bayer K2631 has been studied. Rate data were obtained free of mass-transfer influe nce in a continuous differential reactor operated at 1.6 MPa and 45-90 degrees C. As IB-MeOH mixture behaves non-ideally, kinetic analysis h as been performed by using the UNIFAC activities. Factors, other than the non-ideality of the liquid phase, have been found to play a decisi ve role in the catalytic activity of the ion-exchange resin catalyst. Thus, a reformulation of the kinetic equation has been proposed in whi ch the solubility parameter of the reaction medium is included. This e quation provides a good agreement of the predicted rates with the expe rimental ones and of the associated apparent activation energy with th e literature values. (C) 1998 Elsevier Science B.V.