ISSN:
0001-1541
Keywords:
Chemistry
;
Chemical Engineering
Source:
Wiley InterScience Backfile Collection 1832-2000
Topics:
Chemistry and Pharmacology
,
Process Engineering, Biotechnology, Nutrition Technology
Notes:
New data are reported on the crystallization kinetics of potassium sulfate solutions in a laboratory-scale continuous MSMPR cooling crystallizer. Population density distributions determined down to 1 μm by laser light scattering and sieve analysis are corrected for the effects of crystal agglomeration and shape variation and are used to determine accurate growth and nucleation rates. The crystal growth rate is strongly size-dependent, second order with respect to supersaturation, with a high overall activation energy. The surface reaction contribution to the growth process is comparatively large, with a diffusion dependency that increases with crystal size and temperature. While largely consistent with most previous studies, a marked deviation is detected in growth rates at small sizes at which very strong curvature is exhibited in the population density distributions. Secondary nucleation rates vary linearly with suspension density, and the zero size order and activation energy are similar to those of growth but significantly are both much lower at a larger effective size. These observations support the view that growth rate dispersion may be responsible in large part for the substantial variation in reported secondary nucleation kinetics.
Additional Material:
6 Ill.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1002/aic.690321210
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