Simulation and analysis of an industrial system of columns for ethanol distillation. A typical industrial system of distillation columns involves three columns for hydrated ethyl alcohol production. In order to obtain a better understanding of the behavior of this system, several sample points were installed along the distillation unit for measuring temperature, pressure and flow values, and also for collecting liquid phase samples in order to determine the corresponding alcoholic concentrations. The distillation unit involves three rectification and stripping columns. The experimental measurements made possible the evaluation of the quality of the process simulation results. The simulation results indicate that, among the equations available in process simulation for calculating the activity coefficients, the NRTL model was the one that leads to the best agreement with the experimental data, with deviations around 2 and 2.5% in relation to temperatures and alcohol concentrations respectively, whose values were measured in several trays of the distillation unit.