An equimolar binary mixture of ethanol and water is to be separated in a still pot that initially contains 0.575 kmol of the mixture. You can set the operating pressure, P, of this batch distillation, where P can vary from 700 to 900 mmHg so that the ideal gas assumption holds. This simulation plots the temperature of the liquid in the still, T_s (green), and the temperature of the distillate (i.e., condensed vapor exiting from the still), T_D (magenta), versus time. As expected, T_D lags behind T_s because the distillate is richer in ethanol. The compositions in the still, x_S, and in the distillate, x_D, are also plotted. For this transient problem, computations include both the mass and the energy balances. For higher total pressure values, the temperature profiles are shifted to higher values. A constant-heating policy of the still pot is used with q = 2.125 kW.