Zero-gravity distillation (ZGD) represents an attractive method to perform small-scale distillation processes. In contrast to gravity in conventional distillation units, capillary forces, for example arising in metal foams, are used to guide the liquid phase. In this work, an experimental ZGD setup was constructed. A novel mathematical model was developed which allows the simulation of ZGD units. The model includes coupled momentum, heat and mass transfer equations for the liquid and vapor phases as well as heat conduction equation for the unit walls. The fluid dynamics is determined using the hydrodynamic analogy concept. The numerical simulations were successfully validated with the obtained experimental results.