OPTIMIZING CONTROL OF VARIABLE CYCLE TIME SIMULATED MOVING BEDS

Abstract

Simulated moving bed (SMB) is a cost-efficient chromatographic technique employed for difficult separation tasks. SMB processes exhibit complex dynamics, e.g., its hybrid nature due to the inlet/outlet port switches with nonlinearities and delays. The novel feature presented in this work is the extension of the ‘cycle to cycle’ control concept to make use as manipulated variables, of the four sectional flow rates and the switch time. Its effectiveness is demonstrated through two case studies; the startup of a SMB unit under plant-model mismatch and the rejection of a pump disturbance.