Manipulation of vapour split in Kaibel distillation arrangements

•Studying the necessity of manipulating vapour split in Kaibel arrangements.•Identifying the benefit of using active VS control versus the possible loss of a fixed split ratio.•Approach 1: Vmin diagram to study the effect of VS on energy needs for different feed compositions.•Approach 2: rigorous simulations using UNISIM.•On-line adjustment of the vapour split helps handling expected feed property variations.

In this paper, we want to show how we can gain more from a Kaibel distillation column by considering a degree of freedom which is normally not used. Two methods are used to study the effect of vapour split manipulation, namely a shortcut method and rigorous simulations. Using a case-study, we show that we may not be able to operate close to minimum energy requirement for some feed disturbances as we have the vapour split fixed.