Simulation and experimental investigation of a novel supersaturation feedback control strategy for cooling crystallization in semi-batch implementation

A novel feedback control strategy by semi-batch implementation for cooling crystallization is proposed, in which the supersaturation is controlled by manipulating the feed flow rate of the concentrated solution rather than using the temperature. Different supersaturation control (SSC) approaches have been simulated and compared in three cooling crystallization operation modes: batch cooling crystallization using temperature to control supersaturation (T-SSC), semi-batch crystallization that uses the feed flow rate to control supersaturation (F-SSC) and combined batch cooling and semi-batch crystallization based on a combined mode of control (TF-SSC). A detailed comparison of these three scenarios is presented through numerical simulations, which enables the identification of the optimal operating mode of a cooling crystallizer for various types of crystallization systems. The potential advantages and prospects of the semi-batch SSC mode are discussed. By developing a suitable experimental system, proof-of-concept experimental demonstrations are also presented to support the simulation results. (c) 2020 Elsevier Ltd. All rights reserved.