Chemical Engineering Research & Design, Vol.78, No.4, 542-548, 2000
On the impact of mass and heat integration on design and control of distillation column systems
The influence of mass and heat integration on design and control of three different column systems is investigated. Frequency dependent Relative Gain Analysis (RGA) is used to assess the merits of design modifications for the control loop decoupling of a binary heat-integrated distillation column. For the separation of a ternary mixture, the direct sequence and one of its heat-integrated variants are investigated. Using steady-state sensitivity analysis, it is shown that the concentration of low boiling components in the feed to the second column has a strong impact on the energy demand and controllability of column sequences. An additional loop controlling this concentration is recommended if large disturbances in feed composition are to be expected. Where necessary, the results are verified by nonlinear closed-loop simulation.