Time-scale modeling and optimal control of freeze-drying

► Time-scale analysis is used to obtain a simplified first-principle-based model for freeze-drying processes. ► The matrix-scale model is the core of the proposed optimal control problem. ► The optimal conditions for minimizing freeze-drying cycle time while preserving quality of the final product are defined. ► Reductions of up to an 17.71% (one control variable case - TL) and up to 25.5% (two control variable case - TL, Pc) are achieved.