This paper presents selected results of the EU-project "Intelligent column internals for reactive separations" (INTINT). Catalytic distillation continues to expand its field of applications. New structured catalytic column internals have been developed in recent years. One of them, Sulzer KATAPAK-S, is the subject of the research presented in this paper. Important parameters of the internals have been examined experimentally in a 250 mm i.d. laboratory column: pressure drop for dry and irrigated packing, dynamic liquid hold-up as well as mass transfer coefficients. The experimental results collected have been used to derive a set of correlation equations describing the above quantities in terms of dimensionless flow parameters. The correlations obtained are used to build a unique software package within the INTINT project for the simulation of catalytic separation processes and the behaviour of catalytic column internals. (C) 2003 Elsevier B.V. All rights reserved.