On the use of process analytical technologies and population balance equations for the estimation of crystallization kinetics. A case study

• Published in: AIChE journal Vol. 58; no. 9; pp. 2650 - 2664
• Main Authors: Gherras, Nesrine, Fevotte, Gilles
• Format: Journal Article
• Language: English
• Published: Hoboken Wiley Subscription Services, Inc., A Wiley Company 01-09-2012; Wiley; American Institute of Chemical Engineers
• Subjects: Ammonia; Analytical chemistry; Applied sciences; Chemical and Process Engineering; Chemical engineering; Computation; Cooling; Cooling rate; crystal growth (industrial crystallization); Crystallization; Crystallization, leaching, miscellaneous separations; design (process simulation); Engineering Sciences; Estimates; Exact sciences and technology; Fittings; Kinetics; Mathematical analysis; Mathematical models; Nucleation; particle/count/measurements; process control; Spectrum analysis; Crystal growth; design (process simulation); Cooling; Process control; In situ; Crystals; Modeling; Population balance; count/measurements; Design; Concentration measurement; crystal growth (industrial crystallization); nucleation; Image analysis; Particle size distribution; Batchwise; Solution crystallization; particle; Kinetics; Kinetic parameter; Fourier-transformed infrared spectrometry; Reflectance; industrial crystallization; process control; design; particle/count/measurements; process simulation; crystal growth
• ISSN: 0001-1541; 1547-5905
• DOI: 10.1002/aic.12776

The batch cooling solution crystallization of ammonium oxalate was performed in water at various constant cooling rates. Measurements of the solute concentration were obtained using in situ attenuated total reflectance fourier transform infrared (ATR‐FTIR) spectroscopy, and final estimates of the crystal size distribution (CSD) were computed; thanks to in situ image acquisition and off‐line image analysis. The crystallization process was then simulated using population balance equations (PBEs). Estimates of the nucleation and the growth parameters were computed through model/experiments fitting. According to the cooling rate, the PBE model allowed distinguishing between two distinct crystallization regimes, separated by an “intermediate regime.” The respective contributions and shortcomings of solute concentration measurements and granulometric data to the identification of nucleation and growth kinetic parameters are analyzed and discussed. It is shown in particular that no real separate estimation of nucleation and growth parameters can be obtained in the absence of CSD data. © 2011 American Institute of Chemical Engineers AIChE J, 2012