A model to simulate the transient behaviour of a heat pump assisted distillation column is presented. The packed bed distillation column is treated as a distributed parameter system with time and space as independent parameters. The column modelling using appropriate basic equations, their application to binary systems, the solution scheme to the model equations and the distillation column simulation algorithm are described. The heat pump simulation algorithm is then coupled with this algorithm and the column transient behaviour with and without heat pump assist is obtained. The results are compared with earlier steady state data in the literature. Copyright © 1991 John Wiley & Sons, Ltd.