(decrease by 2 [mol/h] = 2 cycles disappearance). In the respective case, the temperature gap, between the overhead temperatures of columns, should enable even greater savings in energy, through internal thermal integration. Moreover, a significant "shortage" in start-up period duration, up to 40.6% achieved. In this work, the number of strong assumptions on the fundamental dynamics of the column is reduced, compared to the previous work (Zhao et al. ; Zhao et al. ), since, relies on the well-defined dependence of the thermodynamic properties of the mixture from the temperature.