Therefore, another approach to accelerate the bottom product purification is followed that consists in filling the reboiler initially with pure heavy boiler , so the bottom product is pure from the beginning of the process. Considering this option, the reboiler is initially filled with pure n-butanol for the simulation. The temporal evolution of the temperatures at the product draws and the product purities for this start-up strategy (scenario i, Section 2. the specification already at the beginning of the process with the given start-up strategy.