The multivariable feedback system tracking error is related to the sensitivity matrix S = [I + L]–1and to the uncertainty of plant and instrumentation. The ‘popular' highly interacting 2×2 distillation column problem is solved in a novel manner.

The simulation of batch distillation columns during start-up operations is a very challenging modelling problem because of the complex dynamic behaviour. Only few rigorous models for distillation columns start-up are available in literature and generally required a lot of parameters related to tray or pack geometry. On an industrial viewpoint, such a complexity penalizes the achievement of a fa...

This work presents the carrying out of boiling-point distributions by simulated distillation with direct-column heating rather than oven-column heating. Column-heating rates of 300 degrees C/min are obtained yielding retention times of 73 s for n-tetratetracontane. The calibration curves of the retention time versus the boiling point, in the range of n-pentane to n-tetratetracontane, are identi...

Here MI is the total holdup inside the column, and MD and MB are the condenser and reboiler holdups. S = yD(1 xB) (1 yD)xB is the separation factor and Is = DyD(1 yD) + BxB(1 xB) is the \impurity sum". Note that Is may be extremely small for columns with both products of high purity (1 yD and xB both small) resulting in very large linearized values of 1. The response to changes in the internal ...

Abstract In this work we present a methodology for synthesizing sequences of columns that combine both, the heat integrated and the thermally coupled distillation columns. As a consequence it is possible to design systems capturing simultaneously the advantages of these two approaches. A superstructure based on separation tasks rather in actual columns is proposed. This approach is more flexibl...

Distillation is the most widely used but the most energy-consuming separation process in the chemical industry. The internally Heat-Integrated Distillation Columns (HIDiC) are one of the promising alternatives of the conventional distillation processes to reduce the energy consumptions in chemical processes. The HIDiC has a similar structure to a heat exchanger. The rectifying section is contac...