Comparison of external bulk video imaging with focused beam reflectance measurement and ultra-violet visible spectroscopy for metastable zone identification in food and pharmaceutical crystallization processes

Abstract

• This is a journal article. It was published in the Chemical Engi- The purpose of the paper is twofold: it describes the proof of concept of the newly introduced bulk video imaging (BVI) method and it presents the comparison with existing process analytical technologies (PAT) such as focused beam reflectance measurement (FBRM) and ultra violet/visible (UV/Vis) spectroscopy. While the latter two sample the system in small volumes closely to the probe, the BVI approach monitors the entire or large parts of the crystallizer volume. The BVI method is proposed as a complementary noninvasive PAT tool and it is shown that it is able to detect the boundaries of the metastable zone with comparable or better performance than the FBRM and UV/VIS probes.

Optimal seed recipe design for crystal size distribution control for batch cooling crystallisation processes

“…Extension to the approach could be developed using alternative CSD measurement approaches, based on in-line image analysis or using the recently developed internal or external Bulk Video Imaging (BVI) approaches (Simon et al, 2009b;2009c). The optimal seed recipes are designed for processes with generic apparent sizedependent growth kinetics, and the results are exemplified for the model system of potassium dichromate in water.…”

Comprehensive kinetic model for the dissolution, reaction, and crystallization processes involved in the synthesis of aspirin

“…We believe that this phenomenon is due to the weak adsorption of analyte on the surface of the ATR crystal, because it only takes place during periods of supersaturation. This type of phenomenon has regularly been observed in this work and has also been reported by others using UV/Vis ATR spectroscopic techniques similar to the one used here under supersaturated conditions [9]. Figure 5 shows in particular the kinetic trace isolated at 283 nm, the location of the peak maximum for the spectral band of the desired product ASA and near the maximum of the side product ASAA.…”

“…Each of the terms r represent the rates previously established in Equations (9)(10)(11)(12)(13)(14)(15)(16)(17)(18). The sign and number (only ones for this reaction system) in front of each rate indicates the stoichiometric coefficients (denoted γ's in the following) of each species in the corresponding kinetic step.…”

“…Chemical equations (5-8) can be translated into series of ratelaw equations (9)(10)(11)(12), which can then be used to construct the set of ODEs describing the evolution of the concentration profiles.…”

“…Modeling of reactions, dissolutions, and crystallization processes has been a frequent area of study [7][8][9][10], and each has become a well-understood process. However, the number of real applications has been rather limited because of the little work that has been performed so far to combine these methods into one cohesive model.…”