IMC control strategy for the 13C Isotope Separation Process using a fractional order controller

This paper presents the solution used to control the concentration of the 13C isotope inside the separation column and at its output; more control strategies were approached for this concern: a relay controller, a PID controller, fractional order PI and PID controllers and nevertheless the internal model control with a fractional order PD with a filter - a comparison between those method is also presented. The enrichment of the 13C isotope is resulting from the chemical exchange process taking place between the carbamate and the carbon dioxide. The non-linearity of this process represents a setback in process modeling; after determining the analytical solution for the system in the transitory regime, it is possible to simulate the model for the separation column. The purpose of the process modeling is to be included in the development of the control strategies, in order to obtain the needed 13C isotope concentration while the input flow of the solution has an acceptable value. The advantages obtained are the possibility to reject the effects of the disturbances occurring in the system, the control of the 13C concentration in any point in the separation column's height and the improvement in the case of the system performances of reducing the settling time.