Modification of Crystal Shape through Deep Temperature Cycling

The evolution of particle shape is an important consideration in many industrial crystallizations. This article 12 describes the design of temperature-cycling experiments (between alternating positive and negative supersaturations) to 13 substantially change crystal shape with only a small number of cycles. The growth and dissolution of monosodium glutamate 14 crystals of varying shapes were monitored using in-process attenuated total reflection−Fourier transform infrared spectroscopy 15 (ATR-FTIR), focused beam reflectance measurement (FBRM), particle vision and measurement (PVM), and off-line optical 16 microscopy. The growth and dissolution kinetics were estimated in a multidimensional population balance model based on solute 17 concentration and crystal dimension measurements. This model fitted the experimental data with a limited number of parameters
18 of small uncertainty. In addition, with the estimated kinetic parameters, the model predicted the crystal size and shape 19 distribution in a different temperature-cycling experiment reasonably well. In contrast to previous studies that have estimated 20 kinetics along multiple crystal axes in mixed-tank crystallizers, this study implements dissolution terms in the multidimensional 21 population balance model along multiple axes.