Diffusion and chemical reaction in isoamylene etherification within a cation-exchange resin Original Research Article

The effects of temperature (323–353 K) and the molar ratio of the reagents methanol/isoamylenes (0.3–3.0) on the formation rates of tert-amyl methyl ether (TAME) were measured with different Amberlyst 16 (A16) particle sizes in a continuous stirred tank reactor. The effect of catalyst swelling was studied with several mixtures of reagents (MeOH and IA) and product (TAME) on Amberlyst 16. The particle size influenced the steady state reaction rates most notably at higher temperatures and with substoichiometric feed of the reagents (methanol/isoamylenes), i.e. when the reaction rate should be fast. The estimated effectiveness factors (0.5–1.0) decreased with increasing particle size and increasing temperature. At nonstoichiometric feed ratios of the reagents the value of the estimated effectiveness factor decreased more when methanol was fed in excess. Recalculations of the earlier results of TAME-synthesis demonstrated that when modifying the rate constants obtained from the batch reactor experiments by dividing them by the effectiveness factors, the R-squared values of the regression analysis against temperature increased (improved fit for Arrhenius-type dependency) and the activation energies increased by about 9 kJ mol−1.