Membrane distillation is a technique aimed at separating non-volatile components such as salts from aqueous feed streams. Mathematical modelling of a complex process like membrane distillation allows building further insight needed for effective analysis and optimization of the system, possibly leading to a breakthrough of the technology. Several models have been proposed in the literature for the heat and mass transport in the water channels of the module as well as inside the porous membranes. This article provides a critical review of these models and discusses the pros and cons of the different models to guide the reader into selecting the most suitable simulation approach. Moreover, research gaps in the literature are listed to indicate what is currently missing from a modelling as well as experimental data collection perspective. Areas for further research are suggested. (C) 2015 Elsevier B.V. All rights reserved.