The literature on Dividing Wall Columns (DWCs) has grown extremely rapidly of late, and many researchers have used models for simulating DWCs. With few exceptions, simulations of DWC use interlinked multi-column models based on the equilibrium stage concept. In fact, rate-based (or nonequilibrium) models are more fundamentally sound and more realistic than equilibrium stage models. However, rate-based models are complicated to develop, because more details of the column design, e.g. tray geometry or packing size, and reliable correlations for transport coefficients and pressure drop, are required. This paper describes just such a model, which, via the CAPE-OPEN framework, can be used in any CAPE-OPEN compliant process flowsheet simulation package. We introduce new parallel column model that is rate-based, and equation oriented and can be used to model DWCs of arbitrary configuration. Heat transfer across the dividing wall can be modelled in a straightforward way. We compare the predictions of the model to experimental data from the University of Texas at Austin. The results of comparisons show good agreement between model predictions and experimental data.