A bivariate population balance model (the base of LLECMOD program) for the steady state simulation of liquid extraction columns is extended to simulate pulsed (packed and sieve plate) extraction columns. The model is programmed using visual digital FORTRAN and then integrated into the LLECMOD program. As a case study, LLECMOD is used to simulate the separation performance of a pulsed extraction column. Two chemical test systems recommended by the EFCE (namely toluene-acetone-water and n-butyl acetate-acetone-water) are used in the simulation. Model predictions are successfully validated against steady state experimental data, where good agreements are achieved. The simulated results (holdup, mean droplet diameter and mass transfer profiles) compared to the experimental data show that LLECMOD is a powerful simulation tool, which can efficiently predict the performance of pulsed extraction columns. (C) 2011 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.