(539e) A Comparative Study of Continuous Crystallization in an Oscillatory Baffled Crystallizer and a Mixed-Suspension-Mixed-Product-Removal Crystallizer
- Conference: AIChE Annual Meeting
- Year: 2017
- Proceeding: 2017 AIChE Annual Meeting
- Group: Pharmaceutical Discovery, Development and Manufacturing Forum
Wednesday, November 1, 2017 - 1:58pm-2:20pm
In the work proposed here, a comparison between continuous crystallization in an MSMPR versus an OBR is carried out to assess the differences in final product properties. Continuous operation in both vessels is achieved using peristaltic pumps and vacuum for slurry removal. The residence time distribution (RTD) is studied in each system using homogeneous and heterogenous tracers at different mixing conditions. Continuous cooling crystallizations of paracetamol is then evaluated in both crystallizers at the same feed concentration and mean residence time with varying power density levels. At each power density level, the start-up time and steady state crystal properties (i.e. mean size, CSD) are analyzed to determine the effect of hydrodynamics. A rigid and robust online FTIR probe, capable of correcting for signal interference caused by oscillations, is used to monitor the solute concentration during operation. This study will improve the understanding of oscillatory systems as an alternative crystallization vessel and the understanding of the impact of different mixing mechanisms on the final crystal size distribution.
1. Nagy ZK, Aamir E. Systematic design of supersaturation controlled crystallization processes for shaping the crystal size distribution using an analytical estimator. Chem Eng Sci. 2012;84:656-670. doi:10.1016/j.ces.2012.08.048.
2. Alvarez AJ, Singh A, Myerson AS. Crystallization of Cyclosporine in a Multistage Continuous MSMPR Crystallizer. Cryst Growth Des. 2011;11(10):4392-4400. doi:10.1021/cg200546g.
3. Kacker R, Regensburg SI, Kramer HJM. Residence Time Distribution of Dispersed Liquid and Solid Phase in a Continuous Oscillatory Flow Baffled Crystallizer. Chem Eng J. 2017;317:413-423. doi:10.1016/j.cej.2017.02.007.
4. Hewgill MR, Mackley MR, Pandit AB, Pannu SS. Enhancement of gas-liquid mass transfer using oscillatory flow in a baffled tube. Chem Eng Sci. 1993;48(4):799-809. doi:10.1016/0009-2509(93)80145-G.
5. Ni X, Mackley MR, Harvey AP, Stonestreet P, Baird MHI, Rama Rao NV. Mixing Through Oscillations and PulsationsâA Guide to Achieving Process Enhancements in the Chemical and Process Industries. Chem Eng Res Des. 2003;81(3):373-383. doi:10.1205/02638760360596928.