Integration of design and control: A robust control approach using MPC

This paper presents a method for integrating process control at the design stage. The objective function to be minimised is the sum of the capital cost, operating cost and the cost of variability in the controlled variable. An MPC strategy, designed together with the design of the process, was used to define a robust variability cost in the face of model uncertainty. Also, the robust stability and manipulated variable constraints were incorporated into the problem. A multi-component distillation column was selected as a case study. The proposed integrated design methodology was compared to the traditional design methodology where the design and control steps are performed sequentially. The optimization results show that the integrated design methodology leads to savings of up to 48% as compared to the traditional design methodology.