A continuous multi-stage mixed-suspension mixed-product-removal crystallization system with fines dissolution

This work demonstrates how crystal particle size is affected by the addition of fines dissolution in a mixed suspension mixed product removal (MSMPR) cascade system. The cooling crystallization of paracetamol in water was used as a case study. Two MSMPR cascade configurations were evaluated: (i) nucleation-growth (NG), and (ii) nucleation-dissolution-growth (NDG). Simulation results demonstrate that adding a dissolution step in the MSMPR cascade configuration increases the average product crystal size. Larger crystals and a narrower distribution were obtained due to the removal of fine crystals through the continuous process. However, a small decrease in the achievable yield was observed. Experimental results also showed a similar effect on the final mean size and CSD. The results demonstrate that a dissolution stage can be optimized to increase the final crystal size and CSD by varying the dissolution temperature to optimize the CSD with minimum effect on the achievable yield. (C) 2018 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.