The batch reflux-recycle-reactor (RRR) proposed here was shown to give high product yields and selectivities in the production of tert-ethers. Because the vapor pressures of product ethers are lower than those of the reactants, vapor-phase reactor inlet stream is always rich in reactants in this batch RRR. A first-order reversible reaction rate model was shown to give good prediction of experimental results. The apparent activation energy of the rate constant was evaluated as 24.8 kJ mol(-1). This low value of activation energy for vapor-phase synthesis of tert-amyl methyl ether (TAME) was concluded to be primarily attributed to the significance of transport resistances in the macropores of Amberlyst-15 and also through the thin liquid film covering catalyst particles. In the case of TAME production fractional conversion values reaching 0.91 were obtained at 82degreesC with almost 100% selectivity. Comparison of the results obtained for TAME and tert-amyl ethyl ether (TAEE) synthesis showed that reactivity of methanol was much higher than that of ethanol in the etherification reaction of isoamylene, over Amberlyst-15. (C) 2005 American Institute of Chemical Engineers.