Kinetics of the simultaneous syntheses of ethyl tert-butyl ether (ETBE) and butyl tert-butyl ether (BTBE) over AmberlystTM 35

Abstract

The kinetics of the simultaneous syntheses of ethyl tert-butyl ether (ETBE) and butyl tert-butyl ether (BTBE) over Amberlyst™ 35 (A35) has been studied at 315–353 K in the liquid phase. Different kinetic modeling approaches—namely, empirical power-law modeling, mechanistic modeling based on Langmuir-Hinshelwood-Hougen-Watson (LHHW) and Eley-Rideal (ER) formalisms, and information-based modeling—have been compared. Empirical kinetic equations yield optimal quality of the fit, whereas mechanistic equations can explain the mechanisms of the studied reactions. The best mechanistic equation for both reactions corresponds to an ER-type mechanism in which an alcohol molecule (ethanol or 1-butanol) is adsorbed on one active site and reacts with isobutene from solution to produce the corresponding adsorbed ether molecule (ETBE or BTBE), which desorbs. A model built based on previous data has been used to check the validity of the inferred mechanism, while significantly reducing the number of adjustable parameters in the model.