A model for the prediction of supersaturation level in batch cooling crystallization

A model for predicting the cooling profile used in the batch cooling crystallization was introduced. The model includes the supersaturation- and suspension density-dependent secondary nucleation rate, the supersaturation-dependent growth rate, the seeding condition and the batch time. The cooling profile was predicted by numerically solving the model equation when the constant supersaturation was chosen to be the control target. For the different sets of operating conditions, i.e. seeding condition and batch time, different cooling profiles together with the control target, i.e. different constant levels of supersaturation, were predicted. The predicted supersaturation levels were verified experimentally in the crystallization of potassium dihydrogen phosphate (KDP). The product crystals with mono-modal size distribution were obtained with a cooling mode of reducing secondary nucleation predicted by the model.