Monitoring size and shape during cooling crystallization of ascorbic acid

Seeded batch crystallization of ascorbic acid from water is studied. For that experiments with different linear cooling rates are carried out. The concentration is monitored in-situ with ATR–FTIR spectroscopy. Samples taken during the process were characterized using a previously presented method [Eggers, J., Kempkes, M., Mazzotti, M., 2008. Measurement of size and shape distributions of particles through image analysis. Chemical Engineering Science, in press, doi:10.1016/j.ces.2008.08.007]. It is thus possible to determine the 2D particle size distributions (PSDs) of the samples, i.e. a complete description of size and shape of the particles in the sample. Thus, the influence of operating conditions on product properties such as crystal shape is studied.