IEC 56 |
| Jessica K. Liang1, Derek Wilkinson1, and Kevin J. Roberts2. (1) Department of Chemical Engineering, School of Physical Science and Engineering, Heriot-Watt University, Riccarton campus, Edinburgh EH14 4AS, United Kingdom, (2) Department of Chemical Engineering, Institution of Particle Science and Engineering, University of Leeds, Wood House Lane, Leeds, LS2 9JT, United Kingdom |
| Solution crystallisation is a major technological process for particle formation particularly in the pharmaceutical industry. A critical problem plaguing the industry is the challenge to control the batch-to-batch variation resulting from ill-defined particle formation processes. It should be emphasised that even minor changes in crystallisation conditions, e.g. supersaturation, impurity, cooling rate or reactor hydrodynamics can result in significant variations particle size, shape, purity, polymorphic form and defect structure. In this paper, effects of reactor stirrer materials on crystallisation process were investigated for batch crystallised L-glutamic acid from aqueous solutions at 450ml scale size using industry-standard retreat curve impellers. Two stirrer materials were used: stainless steel and Perspex. The metastable zone width (MSZW) was examined and nucleation kinetic parameters were extracted using the Nývlt method. Stirrer material was found important to the process with significant influence on the nucleation order. Experimental observations and contact angle measurements indicate that the mechanism of the examined nucleation process is surface-induced heterogeneous nucleation. |
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Industrial Crystallization (sponsored by Separation Science & Technology Subdivision)
8:30 AM-12:10 PM, Monday, March 24, 2003 Convention Center -- Room 393, Oral
Division of Industrial and Engineering Chemistry |