Zero-gravity distillation (ZGD) is one of the few ways to establish a small-scale distillation process. In contrast to conventional distillation columns, capillary forces, e.g. induced by metal foams, are exploited to ensure liquid flow in ZGD units. In order to strengthen the knowledge basis necessary for the ZGD equipment design, understanding of the relevant transport phenomena is necessary. In this work, a model for the description of ZGD processes was developed. It includes momentum, heat and species transport in both liquid and vapour phases. Evaporation and condensation influence on momentum transfer is captured in a simplified manner, allowing an approximate local flow velocity determination. The developed model was implemented in the OpenFOAM (R) software and used to numerically simulate methanol/ethanol distillation processes in 2D approximation. In particular, the model was applied to investigate the influence of the metal foam porosity and thickness as well as the length of the foam-free compartment on the velocity, temperature and mass fraction distributions. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.