Characterization and modelling of antisolvent crystallization of salicylic acid in a continuous oscillatory baffled crystallizer

• Published in: Chemical engineering and processing Vol. 97; pp. 180 - 186
• Main Authors: Brown, Cameron J., Adelakun, Juliet A., Ni, Xiong-wei
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.11.2015
• Subjects: Antisolvent; Continuous; Crystallization; Kinetics; Oscillatory baffled crystallizer; Population balance; Oscillatory baffled crystallizer; Kinetics; Continuous; Antisolvent; Population balance; Crystallization
• ISSN: 0255-2701; 1873-3204
• DOI: 10.1016/j.cep.2015.04.012

•We present the use a continuous oscillatory baffled crystallizer for the antisolvent crystallization of salicylic acid.•Solute concentration steady states were maintained for >100 residence times.•Demonstration of extended operation for 6.25h resulting in the production of close to 1kg of product.•Application of simplified population balance for the determination of nucleation and growth kinetic parameters. Using antisolvent crystallisation of salicylic acid as the model process, we report our experimental investigation into the temporal and spatial steady states of solution concentration and mean crystal size in a continuous oscillatory baffled crystallizer. The evolutions of the two parameters over time and distance along the crystallizer are measured for a variety of operating conditions. The results show that the attainment of long term temporal and spatial stabilities (>100 residence times) for the solute concentrations are easily achieved, whereas the temporal steady states of the mean crystal size are more difficult to accomplish, even though the spatial steady states have been obtained. A simplified population balance model is applied to the experimental data for the determination of nucleation and growth kinetic parameters. From which both the solution concentration and the mean size were predicted and matched to experimental values reasonably well. In addition, we have identified and executed the conditions of long term steady states for extended operation of 6.25h to produce close to 1kg of crystal product with minimal variation in crystal size (±3.01μm).