n-Hexyl acetate esterification was carried out in a reactive distillation pilot scale column (diameter 162 mm, overall packing height 11.6 m). Sulzer Katapak((R))-S-500.Y filled with Amberlyst CSP2 was used as catalytic internal. The new experiments extend an investigation of Schmitt et al. [1] that was carried out in the same column with Sulzer Katapak((R))-S-250.Y The comparison of both series illustrates the influence of modifying the catalytic internals in pilot plant scale. Simulations with a stage-based model, that includes reaction kinetics, show good agreement with the experimental data. The characteristics of both catalytic internals are correctly predicted. Experience with the formation of 1-hexene as a by-product is discussed. (c) 2004 Elsevier B.V All rights reserved.