The batch unit operation used in this work was a conventional process with constant reflux. Thus, the
unit was operated at total reflux until steady-state was reached, at which point the reflux was modified.
Attainment of the steady-state condition was determined by the temperature progression from the beginning of the distillation operation, which was detected with ten thermocouples distributed throughout the tower, as shown in Figure 2a. To determine the time necessary for process stabilization (startup), the derivative of the temperatures in the unit was analyzed (Figure 2b). Thus, it was possible to precisely determine the transient state and the stationary state.