Similarly, one can notice for zero arcs that, again, they become longer with time: the second one is three times longer than the first one, the third one is 20% longer than the second one, the fourth one is almost 13% longer than the third one, and the fifth one is more than 5 times longer than the forth one. Compared to the previous case the recovery rate is somewhat improved with the decrease of tray hold-up, as it brings 0.61% . Fig 3b .. shows the optimal control pattern for binary distillation case with the influence of tray hold-up. consecutive production of cyclohexane, n-heptane, and finally, toluene, is achieved.