Simulation of Multicomponent Batch Distillation: Semi-Rigorous Model without Holdups

The semi-rigorous model without holdups and the semi-rigorous model with minimum holdups give almost the same results. However, the former uses integration step 0.1 h and the later integration step 0.00001 h. This, and the fact that a semi-rigorous model describes the dynamics of the batch distillation process more reliably than a shortcut model, make the semi-rigorous model without holdups more suitable for dynamic optimisation of the process. For calculation of the composition in the condenser, in each step of time, a modified Levenberg-Marquardt method is used. Imposing the constraints is avoided by introducing the composition normalization.