Chromatographic separation processes provide a powerful tool for the separation of mixtures in which the components have different adsorption affinities, especially when high purities are required. In this area, simulated moving bed (SMB) technology is becoming an important technique for large-scale continuous chromatographic separation processes since it provides the advantages of a continuous countercurrent operation while avoiding the technical problem of a true moving bed. Because of the complex dynamics of the process, the choice of the optimal operation parameters and the control of the process in order to keep the product specifications at any time is not straightforward. For this challenging task, a reliable dynamic model of the process is necessary which is accurate enough as well as efficient enough in order to permit its online use for model based control. The purpose of this contribution is to review the state of the art in dynamic modeling of SMB chromatographic separation processes, highlighting new trends and results in the design of computationally effective simulation models suitable for online applications.