Observer design for a ternary distillation column with side stream

This paper investigates the problem of observer design to provide temperature and molar fraction spatial profiles in a ternary distillation column with side stream. Indeed, both temperature and molar fraction spatial profiles are required to be used in advanced controller design. Such an estimation problem is usually solved using an implicit observer which requires an optimization algorithm when a differential algebraic system is used. In this paper, we consider a realistic nonlinear differential algebraic equation based model validated experimentally. We propose an approach to design an explicit observer that reconstructs all the state variables with an asymptotic convergence. The observer is build as a coupling of two nonlinear observers in full interconnection. Finally, the performance of the proposed observer is illustrated using a model of a ternary distillation column with side stream.