Based on comparisons of some published models with experimental data obtained by FRI (Fractionation Research Inc.), an improved model for estimating the effective interfacial area of structured packing applicable to elevated pressure distillation was proposed. This model was developed on the basis of that proposed by Gualito et al., and the improvement was made by adding a factor reflecting pressure effect. The proposed model was validated by comparison with experimental data in the literature. The results showed that the improved model could give a more reliable estimation than the cited ones for structured packed columns under elevated operating pressures. (c) 2006 Elsevier B.V. All rights reserved.