A relevant role in the performance of a SMBR unit is played by the characteristics of the stationary phase. This is analysed in detail in this work using as a model system the synthesis of methyl acetate on sulphonic resins, for which extensive experimental data on the reaction and equilibrium parameters as a function of the acid capacity of the resins are available. It is found that the best suited stationary phase for a SMBR should exhibit large product/product and low product/solvent selectivities and either a large catalytic activity or a large reactant/product selectivity. (C) 2004 Elsevier Ltd. All rights reserved.