Solid hollow fiber cooling crystallization (SHFCC) is a new technique suitable for crystal size distribution (CSD) control of aqueous/organic systems from bench to industrial scale. Solid hollow fiber devices possessing good temperature control and operational flexibility can serve as seed/nuclei generators, stand-alone crystallizers, or supersaturation creation devices. Operating schemes implemented include feed recycling, once-through, and solid hollow fiber crystallizer-completely stirred tank (SHFC-CST) in-series operation mode. The performance of SHFCC of aqueous ICNOs solutions was assessed against mixed suspension mixed product removal (MSMPR) crystallizer data. Feed recycling and the once-through operation modes were similar and characterized by broader CSDs and lower reproducibility due to generation of a large number of fines causing slow filtration and localized growth on the filters. SHFC-CST in-series operation proved successful yielding narrow and reproducible CSDs with mean sizes between 100 and 150 μm, 3-4 times lower than those of MSMPR crystallizers. Also, 90% of the crystals were smaller than 370 μm compared to 550-600 μm for MSMPR crystallizers. Further, the number of crystals generated per unit volume was 2-3 orders of magnitude higher. SHFC-CST in-series crystallization of salicylic acid from ethanol solutions clearly showed that, unlike other membrane hollow fiber based crystallization techniques, SHFCC does not suffer any performance loss for organic systems.
All Science Journal Classification (ASJC) codes
- Chemical Engineering(all)
- Industrial and Manufacturing Engineering