INTEGRATED DESIGN AND CONTROL OF REACTIVE DISTILLATION PROCESSES

Abstract

Superior controllability of reactive distillation (RD) systems designed at the maximum driving force (design-control solution) is demonstrated in this work. Binary or multi-element single or double feed RD systems are considered. Reactive phase equilibrium data, needed for driving force analysis and design of the RD system, is generated through an in-house property prediction tool. Next, rigorous steady state simulation is carried out in ASPEN plus in order to verify that the predefined design targets and dynamics are met. Finally, a multi-objective performance function is employed to quantify the performance of the RD systems in terms of energy consumption, sustainability metrics (total CO2 footprint), and the control performance. Controllability of the designed system is evaluated using relative gain array (RGA) and Niederlinski Index (N_I), to indicate thedegree of loop interactions, and system stability respectively. Further verification is done through the dynamic simulations of the RD systems using proportional integral (PI) controllers and model predictive controllers (MPC). The design-control of the RD systems corresponding to other alternative designs that do not take advantage of the maximum driving force is also investigated. The analysis shows that the RD designs at the maximum driving force, compared to the alternative designs exhibit the followings: 1) superior design, as indicated by less energy consumption and lower carbon footprint, 2) enhanced controllability, as indicated by Integral Absolute Error (IAE) and total variation of input (TV).Finally, the integrated design-control framework to perform all the design and control tasks is converted to a computer-aided toolbox for quick implementation, design and control of the desired RD systems.