In a second step, ie. high-pressurized process, as supposed the initial arc match with zero distillate rate (total reflux condition-stripper), but the final with maximal distillate rate. Further, it is observed that the optimal control trajectory is composed of almost all bang-bang arcs, with two consecutive singular arcs preceding the final maximal distillate arc. There are 13 commutations between different types of control, an interesting fact is that the singular arc(s) are 'positioned' again in the penultimate period, whereas here it lasts approximately 6.25% of the total operation time or more than 3 times shorter than in an LP step. In summary, the optimal control has an equal number of bang and zero arcs, 6, and one singular arc.