Modification of Crystal Shape through Deep Temperature Cycling

• Published in: Industrial & engineering chemistry research 2014-04, Vol.53 (13), p.5325-5336
• Main Authors: Jiang, Mo, Zhu, Xiaoxiang, Molaro, Mark C, Rasche, Michael L, Zhang, Haitao, Chadwick, Keith, Raimondo, Davide M, Kim, Kwang-Ki K, Zhou, Lifang, Zhu, Zhilong, Wong, Min Hao, O’Grady, Des, Hebrault, Dominique, Tedesco, John, Braatz, Richard D
• Format: Article
• Language: English
• Subjects: Beams (radiation); Crystals; Dissolution; Mathematical models; Optical microscopy; Particle beams; Particle shape; Population balance models; Reflectance
• ISSN: 0888-5885; 1520-5045
• DOI: 10.1021/ie400859d

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